阅读说明：本技术 涂敷喷嘴 (Coating nozzle ) 是由 加藤千依 胜野智晶 于 2019-06-21 设计创作，主要内容包括：本发明提供涂敷喷嘴,抑制因排出量、涂装距离及涂料温度的影响造成的涂敷图案宽度变动并使涂敷图案宽度稳定。涂敷喷嘴(10)在内部设有供涂料导入的导入通路(21)、从导入通路下端开口沿宽度方向扩展并具有宽度比导入通路大的空间容积的大致扇状梯形的扩大通路(22)及与扩大通路下方连通的狭缝状间隙即狭缝通路(23),狭缝通路具有供高粘性涂料(P)排出的呈弧状延伸的狭缝排出口(23a)和在其相反侧的扩大通路侧呈弧状延伸的狭缝入口(23b),且宽度从狭缝入口朝狭缝排出口变大地形成,将相对狭缝排出口的弧的曲率半径设为R,将相对狭缝排出口的弧的弦长设为Lt时,R与Lt的关系为Lt/R×100(％)＝70～130。(The invention provides a coating nozzle, which can restrain the variation of the width of a coating pattern caused by the influence of the discharge amount, the coating distance and the coating temperature and stabilize the width of the coating pattern. The coating nozzle (10) is internally provided with an introduction passage (21) for introducing the coating material, an expansion passage (22) which expands from the lower end opening of the introduction passage in the width direction and has a space volume larger than that of the introduction passage and a slit passage (23) which is a slit-shaped gap communicating with the lower part of the expansion passage, wherein the slit passage has a slit discharge port (23a) which is extended in an arc shape and used for discharging the high-viscosity coating material (P), and a slit inlet (23b) which is extended in an arc shape on the expansion passage side opposite to the slit discharge port, the width of the slit passage is formed from the slit inlet to the slit discharge port in an enlarged manner, the curvature radius of the arc opposite to the slit discharge port is R, and the relation between R and Lt is Lt/R multiplied by 100 (%) -70-130 when the chord length of the arc opposite to the slit discharge port is Lt.)

1. A coating nozzle provided with an introduction passage into which a coating material is introduced, an expansion passage which expands from an opening at a lower end of the introduction passage in a width direction perpendicular to a coating direction and has a space volume larger in width than the introduction passage, and a slit passage which is a slit-shaped gap and communicates with the expansion passage in the width direction at the lower end of the expansion passage and has a width smaller than a width of a direction perpendicular to the width direction at the lower end of the expansion passage,

the slit passage has a slit discharge port extending in an arc shape for discharging the paint and a slit entrance for allowing the paint to enter from the enlarged passage side on the opposite side, and when a curvature radius of an arc facing the slit discharge port is R and a chord length of the arc facing the slit discharge port is Lt, a relationship between R and Lt is Lt/R × 100 (%) -70 to 130.

2. A coating nozzle according to claim 1,

the coating nozzle is configured by assembling a plurality of structures, and the slit passage is formed between 2 structures out of the plurality of structures.

3. A coating nozzle according to claim 1 or 2,

the slit passage is disposed so as to be shifted from an extension line extending in the plumb direction from the opening position of the lower end of the introduction passage.

4. A coating nozzle according to any of the claims 1 to 3,

the central angle of the arc of the slit outlet relative to the slit passage is in the range of 80-100 degrees.

5. A coating nozzle according to any of the claims 1 to 4,

the slit passage is formed to have a width increasing form that increases in the width direction from the slit entrance toward the slit exit.

6. A coating nozzle according to any of the claims 1 to 5,

the opening of the slit outlet of the slit passage is constant in a central portion in the width direction in a direction perpendicular to the width direction, and the width in the direction perpendicular to the width direction is gradually reduced from both sides of the central portion toward both ends in the width direction.

Technical Field

The present invention relates to a coating nozzle for high-viscosity paint, which is used in slit coating for spraying high-viscosity paint such as coating-type vibration damping material onto a coating object, used in vehicles such as automobiles, and which is attached to the tip of a coating spray gun for spraying high-viscosity paint onto the surface of the coating object to spray the high-viscosity paint.

Background

In recent years, in order to reduce the weight of a vehicle body for the purpose of improving fuel consumption and the like, there is a growing trend toward the use of a vibration damping material for application to a floor of a vehicle such as an automobile, which is applied by spraying a highly viscous coating material containing an acrylic resin and inorganic particles as main components, instead of a conventional asphalt patch-type vibration damping sheet having a high specific gravity. In addition, for the application of such a highly viscous paint for vibration suppression or the like, automation is being achieved by a coating robot capable of shortening the process time, and as a method for applying the paint, for example, as shown in patent documents 1 to 3, there are known methods of: a slit type application nozzle is attached to a tip end of an application spray gun held by a robot arm, a high viscosity paint is pressure-fed to the slit type application nozzle by a pump or the like, and the high viscosity paint is discharged from the slit type application nozzle in a film (sheet) form under the pressure of the high viscosity paint and is blown to an object to be coated such as a vehicle body.

A coating apparatus for automatically coating (blowing) a high-viscosity paint in a fixed amount to a coating object such as an automobile body of an automobile is described based on the disclosures of patent document 1 and patent document 2, and as shown in fig. 8, a coating apparatus 50 equipped with a slit-type coating nozzle N includes a material container 51, a plunger pump 52, a filter 53, a regulator 54, a heat exchanger 55, a fixed displacement pump 56, a robot arm 57, and the slit-type coating nozzle N.

The material container 51 stores paint, the plunger pump 52 fills and pressure-feeds the paint to the entire coating facility 50, the filter 53 removes foreign matters mixed in the paint, the regulator 54 appropriately maintains the pressure of the paint in the coating facility 50, the heat exchanger 55 maintains the temperature of the paint in the coating facility 50 constant, the constant delivery pump 56 is driven by a servo motor to adjust the discharge amount of the paint toward the slit-type coating nozzle N, and the robot arm 57 allows the coating nozzle N to move freely relative to a body to be coated such as a vehicle body.

In the automatic coating using the robot arm 57, the coating position with respect to the object to be coated can be controlled by freely moving the coating gun G held by the robot arm 57 and having the slit coating nozzle N attached to the tip end thereof, and the coating film thickness can be controlled by adjusting the moving speed of the coating gun G (slit coating nozzle N).

Here, according to the conventional slit type coating nozzle disclosed in patent documents 1 to 3, in order to make the width of the coating pattern larger than the width of the discharge port, the paint discharged from the nozzle is spread in the width direction as much as possible by increasing the discharge angle or the like, and the paint discharged from the nozzle is spread radially and blown toward the coated surface. Thus, the spread pattern (spread pattern) of the coating material discharged from the nozzle, that is, the application pattern width largely depends on the pressure of the coating material passing through the discharge port. Conventionally, the application pattern width is adjusted by changing the discharge amount by pressure control. That is, conventionally, the application pattern width is controlled by the discharge amount.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2014-155904

Patent document 2: japanese patent laid-open No. 2012-11284

Patent document 3: japanese laid-open patent publication No. 11-179243

Disclosure of Invention

Problems to be solved by the invention

However, in actual coating using the conventional slit coating nozzles disclosed in patent documents 1 to 3, variation in the width of the coating pattern due to variation in the discharge amount is large. In addition, the coating pattern also varies greatly depending on the coating distance and the coating temperature (material viscosity).

In particular, in the technique of patent document 1, the opening area of the nozzle is reduced in order to secure the shear rate in the low discharge region, but if the opening area of the nozzle is reduced, the pressure of the paint passing through the discharge port increases, and thus the variation in the width of the application pattern due to the change in the viscosity (paint temperature) of the paint and the coating distance becomes large.

In addition, in the technique of patent document 2, the flatness ratio is reduced to ensure the shear rate and smooth the coating film surface, but the discharge amount and the coating distance have a large influence on the coating pattern width.

Therefore, in the coating using the conventional slit coating nozzle, fine adjustment of the discharge amount, the paint temperature, and the coating distance for obtaining a target desired coating pattern width is difficult, and high-precision adjustment is required.

That is, in order to stabilize a target desired coating pattern width in coating using a conventional slit coating nozzle, it is necessary to set and adjust a discharge amount, a coating distance, and a coating temperature precisely and finely (in small units), and a high-precision coating control technique for setting a constant discharge amount, coating distance, and coating temperature is necessary. That is, it is necessary to finely set and adjust the discharge amount and the paint temperature, and to maintain the discharge amount and the paint temperature constant, and a high-precision and high-performance apparatus such as a constant displacement pump in which the discharge amount is stable, a heat exchanger in which the paint temperature is constant and which can be finely adjusted, and the like are required. In addition, a robot for fine setting and adjustment in which a coating distance is kept constant also needs to be controlled very finely, and a program input mechanism for robot teaching (instruction) is also complicated.

In particular, the application type vibration suppressing material for suppressing vibration and sound of vehicles such as automobiles is applied not only to a horizontal surface but also to an uneven surface, a curved surface, and a vertical surface, and when a high-viscosity paint for the application type vibration suppressing material is applied, a relative positional change occurs between the surface to be applied and the application spray gun. Therefore, the higher the coating distance dependency of the coating pattern width, the more likely the coating pattern width is to vary. Even if the position of the coating spray gun is displaced following the constancy of the coating distance, that is, the shape of the surface to be coated, a highly complex mechanism height control technique such as detection of the position shape of the surface to be coated, response of the robot arm, and the like is required. In addition, in the case of a curved surface shape or the like, the inertial force of the robot arm is taken into consideration, and the discharge amount needs to be dealt with in conjunction with acceleration and deceleration of the movement of the robot arm, which complicates the control.

Accordingly, the present invention has an object to provide a coating nozzle capable of suppressing variation in the width of a coating pattern due to the influence of the discharge amount, the coating distance, and the temperature of a coating material, thereby stabilizing the width of the coating pattern.

Means for solving the problems

An application nozzle according to claim 1 of the present invention is an application nozzle including a slit passage which is a slit-shaped gap having a larger spatial volume than an introduction passage into which a paint is introduced and which communicates in a width direction at a lower end of an enlarged passage, the application nozzle including a slit discharge port extending in an arc shape and through which the paint is discharged, and a slit inlet on the side of the enlarged passage opposite to the discharge port, wherein when a radius of curvature of an arc opposite to the slit discharge port is R and a chord length of the arc opposite to the slit discharge port is Lt, a relationship between R and Lt (%)/R × 100) is 70 to 130.

The introduction passage is a paint input side to which the paint pressurized by the pressure mechanism such as a constant displacement pump is input, and is formed in a columnar shape extending in a longitudinal direction, for example, to communicate with the expansion passage, and guides the input paint to the expansion passage.

The expanding passage communicates with the introducing passage, expands in a width direction than an opening at a lower end of the introducing passage, and has a spatial volume larger in width than the introducing passage. Here, the width direction refers to a direction perpendicular to the coating direction (traveling direction) of the coating nozzle. The shape of the enlarged passage is not particularly limited, and is generally formed to be enlarged in width downward, and may be, for example, a substantially trapezoidal shape enlarged in width downward from above, that is, having a small upper width and a large lower width, or an arc-shaped substantially fan-shaped trapezoidal shape at least the lower side of which is formed to extend in the width direction, among substantially trapezoidal shapes having a small upper width and a large lower width. The coating direction is a moving direction of an application nozzle that blows a coating film on a surface to be coated, and is a coating line direction in which a coating film on the surface to be coated (workpiece) is coated with a coating material discharged from the application nozzle. Corresponding to the thickness direction of the coating nozzle.

The slit passage is a slit-shaped gap which communicates with a lower portion of the enlarged passage and has a width smaller than a width of a lower end of the enlarged passage in a direction perpendicular to the width direction (a thickness direction which is a direction parallel to the coating direction), and the slit passage has a slit discharge port extending in an arc shape through which the coating material is discharged and a slit entrance port through which the coating material in the enlarged passage is fed on the side of the enlarged passage opposite to the slit discharge port, and the coating material fed from the enlarged passage to the slit entrance port is discharged from the slit discharge port.

The slit passage has a relationship of Lt/R × 100 (%) (70 to 130), preferably Lt/R × 100 (%) (75 to 125), and more preferably Lt/R × 100 (%) (80 to 123) between R and Lt, when R is a curvature radius of an arc of the slit outlet and Lt is a chord length of the arc of the slit outlet.

Here, the curvature radius R of the arc of the slit outlet is not limited to a constant value over the entire area, and when the arc shape gradually changes, that is, when the arc has a changing curvature radius including the arc of the ellipse, the average value of the maximum value and the minimum value of the variable curvature radius is defined as the curvature radius R of the arc of the slit outlet.

The chord length Lt of the arc with respect to the slit discharge opening is a dimension of a line segment connecting both ends of the slit discharge opening in the width direction with a straight line.

The aforementioned Lt/R × 100 (%) < 70 to 130 means that 70 ≦ Lt/R × 100 (%) < 130, and when calculated from the ratio of Lt/R, the ratio of Lt/R is 0.7 or more and 1.3 or less.

The opening of the slit outlet is generally a shape in which a width (lateral width) in a width direction perpendicular to a coating direction is increased and a width (vertical width) in a direction parallel to the coating direction, that is, a width (vertical width) perpendicular to the width direction is decreased.

The shape of the slit passage may be defined so that at least the slit outlet extends in an arc shape and the relationship between R and Lt falls within a predetermined range, and is preferably an arc-shaped substantially fan-shaped trapezoid having a width that increases from the slit inlet side toward the slit outlet side, that is, at least the lower side of a substantially trapezoid having a small upper width and a large lower width. Further, when the lower side of the enlarged passage is formed in an arc shape extending in the width direction, the slit passage is arranged along the arc of the enlarged passage, and the slit entrance is formed in an arc shape extending in the width direction. In the case where the slit entrance extends in an arc shape, the arc may be a straight arc shape having a constant radius of curvature with respect to the arc of the slit entrance, or may be an elliptical arc shape having a variable radius of curvature in which the arc shape gradually changes. Further, the central angle of the arc with respect to the slit discharge opening and the central angle of the arc with respect to the slit entrance may not necessarily coincide. That is, the relationship between the slit outlet and the slit inlet may be constant or may be varied in the width direction.

However, the viscosity of the coating material suitable for application by the application nozzle is 0.1 pas/20 to 10 pas/20 ℃ (shear rate 9400 s)^-1High-viscosity coatings in the range of/20 ℃). When the viscosity of the paint is too low, the spread of the paint discharged from the slit outlet of the application nozzle becomes large, and therefore, even if the paint is specified to have a specific slit shape, the variation in the width of the application pattern due to the discharge amount (pressure), the temperature of the paint (viscosity, fluid resistance), and the application distance (gun distance) becomes large. On the other hand, when the viscosity of the coating material is too high, clogging and coating material spots are likely to occur, which affects the coating properties. If the temperature is 0.1 pas/20 ℃ or higher and 10 pas/20 ℃ or lower (shear rate 9400 s)^-1A high-viscosity paint in the range of/20 ℃) reduces the spread of the paint discharged from the slit outlet of the coating nozzle, and therefore, the variation of the coating pattern width due to the influence of the discharge amount (pressure), the paint temperature (viscosity, fluid resistance) and the coating distance (spray gun distance) does not occur, and a stable coating pattern width can be obtained, and the coating property does not deteriorate. More preferably, it is 0.5 pas/20 ℃ or higher and 5 pas/20 ℃ or lower (shear rate 9400 s)^-1More preferably 1 pas/20 ℃ or higher and 5 pas/20 ℃ or lower (shear rate 9400 s)^-1High-viscosity coatings in the range of/20 ℃).

The discharge amount of the coating material is preferably set to a range of 3000 cc/min (cc/min) to 10000 cc/min. When the amount of the paint discharged from the slit discharge port is too small, pattern cracks are likely to occur. On the other hand, when the discharge amount is large, the paint applied to the coating surface tends to fluctuate or wrinkle due to the increase in the coating pressure, and smoothness is impaired. When the discharge amount of the paint is in the range of 3000 to 10000 cc/min, smooth coating of the coating film can be achieved without causing pattern cracks or wrinkles of the paint, and good appearance of the coating film can be ensured. More preferably, the discharge amount is in the range of 6000 cc/min to 10000 cc/min.

The coating nozzle according to the invention of claim 2 is configured by assembling a plurality of structures, and the slit passage is formed between 2 structures out of the plurality of structures.

Here, the structure in which the plurality of structures are assembled is a structure in which at least 2 or more separate members are assembled together by a joining means such as a screw or a bolt, and the structure can be disassembled by being divided by removing the screw or the bolt. That is, the plurality of structures are detachably assembled by removing screws, bolts, or the like. The structure may be a 2-layer structure formed by 2 members and having a layer shape in a direction perpendicular to the width direction (a direction parallel to the coating direction, i.e., a thickness direction), a 3-layer structure formed by 3 members, or a multilayer structure having 3 or more layers.

The term "forming the slit passage between 2 structures out of the plurality of structures" means that, when the application nozzle is formed of 2 structures which are separate members, the slit passage is defined by the 2 structures and the slit passage is formed between the 2 structures. In addition, even if the slit passage is formed by a structure of 3 or more divided members, the slit passage is formed by dividing the structure of 2 divided members among them and the slit passage is formed between 2 structures. By forming the slit passage between 2 separate members, even when the slit passage is clogged, the slit passage can be decomposed into 2 members forming the slit passage, and the clogging can be easily eliminated.

In the coating nozzle according to the invention of claim 3, the slit passage is arranged so as to be shifted (offset) from an extension line extending in a plumb direction from an opening position of a lower end of the introduction passage.

The arrangement in which the slit passage is offset from the extension line extending the opening position of the lower end of the introduction passage in the plumb direction means that the positional relationship between the introduction passage and the slit is defined so that the flow path of the paint can be extended as compared with the case where the slit passage is arranged on the extension line extending the opening position of the lower end of the introduction passage in the plumb direction.

The application nozzle according to the invention of claim 4 is such that the central angle of the arc of the slit outlet with respect to the slit passage, that is, the opening of the slit outlet, is in the range of 80 ° to 100 °, preferably 85 ° to 95 °.

In the coating nozzle according to the invention of claim 5, the slit passage is formed in a substantially fan-shaped trapezoidal shape which expands in a width direction from the slit entrance to the slit exit.

Here, the substantially fan-shaped trapezoid is a shape in which at least one long side (lower side) of at least 1 pair of opposing 1 sides (upper side and lower side) in a parallel relationship among trapezoids having parallel sides is replaced with a circular arc having a curvature, and the width of the short side of the opposing 1 sides (upper side and lower side) increases toward the long side.

In the application nozzle according to the invention of claim 6, the opening of the slit outlet of the slit passage is made constant in a central portion in the width direction in a direction perpendicular to the width direction, and the width in the direction perpendicular to the width direction is made gradually smaller from both sides of the central portion toward both ends in the width direction.

Here, the width of the slit outlet in a direction perpendicular to the width direction means a width in a direction parallel to the coating direction of the coating nozzle, that is, a width in the thickness direction of the coating nozzle. The width direction is a direction perpendicular to the coating direction of the coating nozzle.

The term "the width of the opening of the slit outlet in the direction perpendicular to the width direction is constant at the center portion in the width direction and gradually decreases from both sides of the center portion toward both ends in the width direction" means that a portion having a constant width in the direction perpendicular to the width direction is provided at the center portion in the width direction of the slit outlet, and the width in the direction perpendicular to the width direction is gradually decreased from both end sides of the center portion having a constant width in the direction perpendicular to the width direction to both ends in the width direction of the slit outlet. That is, the opening of the slit outlet is formed so as to have a predetermined width in a direction perpendicular to the width direction in a central portion in the width direction, and gradually decrease in width in the direction perpendicular to the width direction toward both ends in the width direction.

ADVANTAGEOUS EFFECTS OF INVENTION

In the coating nozzle according to the invention of claim 1, an enlarged passage that is wider in the width direction than the opening at the lower end of the introduction passage and has a larger spatial volume than the introduction passage is formed below the introduction passage into which the coating material is introduced so as to communicate with the introduction passage, and a slit passage is provided as a slit-like gap that communicates with the enlarged passage along the width direction at the lower end of the enlarged passage. The slit passage has a slit discharge port extending in an arc shape for discharging the paint and a slit entrance on the side of the enlarged passage opposite to the slit discharge port, and when a radius of curvature of an arc facing the slit discharge port is R and a chord length of the arc facing the slit discharge port is Lt, a relationship between R and Lt is in a range of Lt/R × 100 (%) -70 to 130.

According to the coating nozzle of the invention of claim 1, the relation between the radius of curvature R of the arc facing the slit discharge port and the chord length Lt of the arc facing the slit discharge port is defined as the shape of the slit in the range of Lt/R × 100 (%) -70 to 130, whereby the spread of the coating material discharged from the slit discharge port in the width direction is reduced, and the degree of spread in the width direction is reduced. That is, according to the shape of the slit defined in the range of Lt/R × 100 (%) -70 to 130, the spreading of the paint discharged in the width direction in the direction substantially perpendicular to the opening surface of the slit discharge port is suppressed, and the direction of the paint discharged from the slit discharge port is made to be a direction that is not likely to spread radially toward the coated surface side but is close to a straight line. Therefore, variation in the width of the coating pattern due to the coating distance (gun distance) is reduced.

Further, according to the slit shape in which the relation between the curvature radius R of the arc of the opposing slit discharge port and the chord length Lt of the arc of the opposing slit discharge port is defined in the range of Lt/R × 100 (%) -70 to 130, the degree of spreading of the paint discharged from the slit discharge port is small, and therefore, the coating pattern width of the paint discharged from the slit discharge port is less likely to be subjected to pressure or fluid resistance at the time of discharging the paint from the slit discharge port. That is, since the spread of the coating material discharged from the slit discharge port in the width direction is reduced according to the shape of the slit defined in the range of Lt/R × 100 (%) -70 to 130, the application pattern width is less likely to vary even if the discharge amount by the pressure control is changed, and the application pattern width is less likely to vary even if the coating material temperature or the coating material viscosity is changed.

As described above, according to the coating nozzle of the invention according to claim 1, the variation in the width of the coating pattern due to the influence of the discharge amount, the coating distance, and the temperature can be suppressed, and the width of the coating pattern can be stabilized.

According to the coating nozzle of the invention of claim 2, since the coating nozzle is configured by assembling a plurality of structures, and the slit passage is formed between 2 structures out of the plurality of structures, even when the slit passage is clogged by the foreign matter, and the coating pattern is disturbed, the coating nozzle can be divided into 2 structures to easily take out the foreign matter. Therefore, in addition to the effect described in claim 1, maintenance is easy, and a coating pattern having a predetermined width can be stably secured. In particular, in the case of a three-layer structure of structures of 3 or more separate members, even when the wall surface forming the slit passage of 2 structures partitioning the slit passage is partially consumed due to wear, only 2 structures partitioning the slit passage need be replaced, and therefore, the cost is low enough. Further, only 2 structures partitioning the slit passage are made of a wear-resistant material, and inexpensive materials can be used for the other structures, so that cost reduction can be achieved.

According to the coating nozzle of the invention of claim 3, since the slit passage is arranged at a position shifted from an extension line extending from the opening position of the lower end of the introduction passage in the plumb direction, the flow path of the coating material can be made longer as compared with the case where the slit passage is arranged at an extension line extending from the opening position of the lower end of the introduction passage in the plumb direction, and therefore, variation in the flow velocity distribution of the coating material fed from the introduction passage to the slit inlet of the slit passage can be reduced. Therefore, in addition to the effect described in claim 1 or claim 2, the smoothness of the paint discharged from the slit discharge port can be improved.

In the coating nozzle according to the invention of claim 4, a central angle of an arc of the slit outlet with respect to the slit passage is in a range of 80 ° to 100 °.

Here, if the central angle of the arc of the slit discharge port with respect to the slit passage is too small, a predetermined application pattern width of, for example, 50 to 100mm cannot be secured, and the pattern width tends to become insufficient. On the other hand, if the central angle of the arc of the slit outlet with respect to the slit passage is too large, the spread of the paint discharged from the slit outlet becomes large, and a pattern crack may occur. Further, the application pattern width depends greatly on the pressure, the fluid resistance, and the like of the paint at the time of discharge from the slit discharge port, and the variation in the application pattern width due to the discharge amount, the coating distance, and the paint temperature may be increased.

Accordingly, when the central angle of the arc of the slit outlet with respect to the slit passage is in the range of 80 ° to 100 °, in addition to the effect described in any one of claims 1 to 3, no pattern crack occurs, and the variation in the application pattern width due to the discharge amount, the application distance, and the paint temperature can be minimized, so that a predetermined pattern width can be ensured more stably. More preferably, the central angle of the arc of the slit outlet with respect to the slit passage is in the range of 85 ° to 95 °.

According to the coating nozzle of the invention of claim 5, since the slit passage is formed to have a width increasing form expanding in the width direction from the slit entrance toward the slit exit, by expanding the coating material from the slit entrance toward the slit exit, in addition to the effect described in any one of claims 1 to 4, a predetermined coating pattern width of, for example, 50 to 100mm can be secured, and a coating film can be made thin, and excessive coating can be prevented.

According to the coating nozzle of the invention of claim 6, since the opening of the slit outlet is made constant in the center portion in the width direction in the direction perpendicular to the width direction and the width in the direction perpendicular to the width direction is made gradually smaller from both sides of the center portion toward both ends in the width direction, the coating material is discharged thickly on the center side in the width direction of the slit outlet and thinly on both ends in the width direction. Therefore, in addition to the effects described in any one of claims 1 to 5, even when the coating film is applied to the end portion side in the width direction, the thickness of the coated portion can be suppressed from increasing. In particular, by defining the relation between the curvature radius R of the arc facing the slit discharge opening and the chord length Lt of the arc facing the slit discharge opening as the shape of the slit in the range of Lt/R × 100 (%) -70 to 130, the spreading of the coating material in the width direction of the coating material discharged from the slit discharge opening is suppressed, and the coating material unevenness is less likely to occur in the width direction of the coating film applied to the surface to be coated. Therefore, even when the end portion side in the width direction of the coating film is coated, the coating film is excellent in smoothness and can be made uniform in thickness.

Drawings

Fig. 1 is an overall perspective view schematically showing a state in which a high viscosity paint is applied by using an application nozzle according to an embodiment of the present invention.

Fig. 2 is a plan view of the coating nozzle according to the embodiment of the present invention.

Fig. 3 is a front view of the coating nozzle according to the embodiment of the present invention, as viewed from the paint discharge side.

Fig. 4 is a sectional view a-a shown in fig. 2 of the application nozzle according to the embodiment of the present invention.

Fig. 5 is a plan view showing a comparison of main parts of the coating nozzles according to examples 1 to 3 of the embodiment of the present invention.

Fig. 6 is a schematic diagram illustrating an expanded state of the coating material discharged from the coating nozzle according to the embodiment of the present invention by comparing example 3 with comparative example 1 (conventional product).

Fig. 7 is a cross-sectional view of a coating film applied by the coating nozzle according to the embodiment of the present invention, showing a state when the coating film is applied at the end in the width direction.

Fig. 8 is a schematic diagram for explaining the overall configuration of a coating apparatus equipped with a slit-type coating nozzle.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In the present embodiment, the same reference numerals and symbols denote the same or equivalent parts and functions, and therefore, redundant description thereof will be omitted.

The coating nozzle 10 of the present embodiment is formed by a main body portion 11 including an exterior portion 11A and an interior portion 11B, and a lid portion 12, and is configured as a substantially fan-shaped trapezoid whose width increases toward a lower distal end side as a whole. The exterior portion 11A of the main body 11 has a substantially fan-shaped trapezoidal shape as a whole, but one (upper) side of the base end portion side of the paint introduction side is formed thick, and the other (lower) end portion side thereof (arc-shaped side) is formed thin, and has an inverted L-shaped cross section. The entire interior portion 11B of the main body portion 11 is formed in a flat plate shape having a substantially fan-like trapezoidal shape, and is disposed on the lower portion side (distal end portion side) of the exterior portion 11A where the thickness is formed to be thin. Further, a lid portion 12 having a substantially fan-shaped trapezoidal shape as a whole is disposed on one surface side of the interior portion 11B opposite to the exterior portion 11A. That is, the internal portion 11B is interposed between the external portion 11A and the lid portion 12 on the lower side of the application nozzle 10. The exterior portion 11A, the interior portion 11B, and the lid portion 12 are fixed by 4 flush screws 28. That is, the flat plate-like inner fitting portion 11B is attached to the outer fitting portion 11A by the embedded screws 28 on the lower side where the thickness thereof is made thin, and the lid portion 12 is attached so as to overlap and abut thereto, and has a thick plate shape of a substantially fan-shaped trapezoid as a whole. As seen in the cross-sectional view shown in fig. 4, the flat plate-like inner portion 11B is attached in close contact with the recessed region (cut-out portion) of the outer portion 11A, which is formed by the step difference and is reduced in thickness, and the upper side and the left and right sides of the cover portion 12, which are the thick convex regions except the cut-out portion 22c of the recessed region described later, are attached in close contact with the upper side and the left and right sides of the inner portion 11B surrounding the through hole 22 described later. As shown in fig. 4, the recessed area (cutout portion) of the exterior portion 11A, which is thinned, accommodates the interior portion 11B and the lid portion 12, and a part of the lid portion 12 protrudes from the body portion 11 side and has a stepped surface on one surface side parallel to the coating direction of the coating nozzle 10. In fig. 1, the fixing by the embedded screws 28 is performed at positions corresponding to the total of 4 positions of the upper left and right 2 positions and the lower left and right end side 2 positions of the cover 12, but the embedded screws 28 and the like are not illustrated in fig. 2 to 5.

The term "fan-shaped trapezoid" as used herein means a trapezoid in which at least 1 side of 1 pair of opposing sides (upper and lower bottoms) in a parallel relationship among 1 pair of parallel-sided trapezoids is replaced with an arc having a curvature.

The entire coating nozzle 10 of the present embodiment is a substantially fan-shaped trapezoid in which the side of the long side (bottom side) among the 2 parallel opposite sides (bottom sides) of the axisymmetric equilateral trapezoid is replaced with an arc having a curvature. The overall shape of each member of the exterior section 11A, the interior section 11B, and the lid section 12 is a substantially fan-shaped trapezoid in which the side of the longer side (lower bottom side) among the parallel 2 opposite sides (bottom sides) in the axisymmetric equilateral trapezoid is replaced with an arc having a curvature. The lower arc is an arc having a curvature curved in a convex shape below the application nozzle 10, and the center side in the width direction of the application nozzle 10 is a convex top (lowermost portion).

As described above, the application nozzle 10 of the present embodiment is configured by assembling a plurality of separate members, i.e., a structure, of the exterior portion 11A, the interior portion 11B, and the lid portion 12, and is detachable and assemblable by the embedded screws 28. Therefore, even when the high-viscosity coating material P is clogged in the coating nozzle 10, the clogging is easily eliminated by decomposition and cleaning thereof.

The coating nozzle 10 of the present embodiment, which is constituted by the body portion 11 including the exterior portion 11A and the interior portion 11B and the lid portion 12, includes, as a passage of the internal space through which the high viscosity paint P passes: an introduction passage 21 through which the high-viscosity paint P is introduced at the proximal end portion side of the body 11; an expansion passage 22 disposed below the introduction passage 21; and a slit passage 23 disposed below the enlarged passage 22 on one end side in the thickness direction (one end side in the direction parallel to the coating direction) in the direction perpendicular to the width direction of the coating nozzle 10.

The introduction passage 21 is a space formed in a substantially cylindrical shape at the center side in the width direction inside the base end portion side of the exterior portion 11A constituting the body portion 11, and a substantially cylindrical introduction pipe 31 for supplying the high viscosity paint P to the application nozzle 10 is connected thereto, and the high viscosity paint P is introduced from the introduction pipe 31. The introduction passage 21 is formed as a through hole in the enlarged passage 22 side that is downward facing the center side in the width direction of the proximal end portion side of the outer sheath portion 11A, and a female screw 31A is screwed into the inner peripheral surface thereof, and the introduction pipe 31 is attached to the proximal end portion side of the outer sheath portion 11A of the body portion 11 by screwing the female screw 31A into a male screw 31b screwed into the outer periphery of the introduction pipe 31, whereby the application nozzle 10 is fixed to the distal end of the introduction pipe 31. Thereby, the high viscosity paint P fed into the inlet pipe 31 at a predetermined pressure is introduced into the inlet passage 21 of the coating nozzle 10.

The expansion passage 22 continuous from the introduction passage 21 includes: a recess 22a formed in the exterior portion 11A in a substantially fan-shaped trapezoidal shape below (on the distal end side); a through hole 22B formed in the inner portion 11B in a substantially fan-shaped trapezoidal shape at the widthwise center side thereof in correspondence with the recessed portion 22 a; and a notch portion 22c formed by a step on the inner surface side of the lid portion 12, that is, the side facing the interior portion 11B side, and cut into a concave region of a substantially fan-shaped trapezoid. The enlarged passage 22 is a space having a substantially fan-shaped trapezoidal shape having a larger space volume than the width of the introduction passage 21, and is wider in the width direction than the opening at the lower end of the introduction passage 21, and is further wider toward the lower side of the coating nozzle 10, that is, toward the arc-shaped distal end side of the coating nozzle 10. As described above, the entire coating nozzle 10 of the present embodiment is a substantially fan-shaped trapezoid in which the side of the long side (bottom side) among the 2 parallel opposite sides (bottom sides) in the linearly symmetrical equilateral trapezoid is replaced with a circular arc having a curvature, and the side of the long side (bottom side) among the 2 parallel opposite sides (bottom sides) in the linearly symmetrical equilateral trapezoid is replaced with a substantially fan-shaped trapezoid in which a circular arc having a curvature with respect to the enlarged passage 22. The lower arc is an arc having a curvature curved in a convex shape below the application nozzle 10, and the center side in the width direction of the application nozzle 10 is a convex top portion (lowermost portion).

Further, a slit entrance 23B of a slit passage 23 which is smaller than the enlarged passage 22 is opened to the enlarged passage 22 between the cover portion 12 side and the inner lid portion 11B, and a slit passage 23 having a substantially fan-like trapezoidal shape is provided below the enlarged passage 22 so as to extend along the arc shape of the through hole 22B of the built-in portion 11B.

The slit passage 23 has a substantially arc-shaped slit outlet 23a through which the high-viscosity paint P is discharged and a substantially arc-shaped slit inlet 23b located at a predetermined depth on the side of the enlarged passage 22 opposite to the slit outlet, and is enlarged in a width direction extending in an arc shape from the slit inlet 23b side toward the slit outlet 23a side in an extension direction in which the slit passage is enlarged in the width direction, relative to the substantially fan-shaped trapezoidal enlarged passage 22 which is enlarged in the width direction toward the distal end side. The slit outlet 23a and the slit inlet 23b are both arc-shaped with a curvature curved in a convex shape below the coating nozzle 10, and the center side in the width direction of the coating nozzle 10 is a convex top portion (lowermost portion).

That is, the slit passage 23 is a slit-shaped gap elongated in the width direction formed between the inner portion 11B side of the body 11 and the lid 12 along the arc extending in the width direction of the lower end portion of the substantially fan-shaped trapezoid of the application nozzle 10 including the body 11 and the lid 12. In detail, the slit passage 23 is a space: the coating nozzle 10 is provided between a notch 22c side of a substantially fan-shaped trapezoidal shape formed on the inner surface side of the cap 12 facing the interior part 11B and a lower end part on the arc side of the interior part 11B on the arc side of the arcuate end part of the coating nozzle 10, and is formed in an arc shape extending in a predetermined width to form a substantially arc shape on the arcuate end part side of the arcuate end part of the coating nozzle 10, and the cap 12 side is located below the expanded passage 22. Further, since the slit outlet 23a and the slit inlet 23b are both arc-shaped, the overall shape of the slit passage 23 may be a substantially arc-shaped, or may be a substantially fan-shaped trapezoid in which two sides (upper and lower bottoms) of 2 opposite sides (bottom sides) parallel to each other in an equilateral trapezoid having a line symmetry with a width increasing from the slit inlet 23b toward the slit outlet 23a are replaced with an arc having a curvature.

As shown in fig. 2, the width direction both ends of the slit outlet 23a extending in an arc shape are designated as "b" as a precautionary measure₁、b₂At this time, the arc (arc b) of the slit outlet 23a of the slit passage 23₁b₂) Has a radius of curvature R larger than that of an arc on the center side of the slit entrance 23b extending in an arc shape, and has a width from the slit entrance 23b side to the slit exit 23a side, and thus, in other words, can be said to be an arc (arc b) facing the slit exit 23a₁b₂) Center point C of₁Converging from the slit outlet 23a toward the slit inlet 23 b. Further, if an arc (arc b) is formed to face the slit outlet 23a₁b₂) When the central angle of (b) is θ, the slit discharge port 23a of the slit passage 23 is expanded by an opening angle θ (opening degree θ).

As described above, the coating nozzle 10 of the present embodiment includes: a main body part 11 having an introduction passage 21 for introducing the highly viscous paint P therein and having an outer fitting part 11A and an inner fitting part 11B which are substantially fan-shaped and trapezoidal as a whole; and a lid 12 which is attached to the body 11 on the side of an arc expanding in the width direction of the body 11 and has a substantially fan-shaped trapezoidal shape as a whole, an expanded passage 22 which is communicated with the introduction passage 21 and has a substantially fan-shaped trapezoidal shape expanding in the width direction compared with the opening at the lower end of the introduction passage 21 and having a spatial volume larger than the introduction passage 21 is formed below the introduction passage 21 by a partition including the inner wall surface of the body 11 and the inner wall surface of the lid 12 of the exterior portion 11A and the interior portion 11B, and a slit-shaped passage 23 which is a substantially arc-shaped slit gap communicating with the expanded passage 22 below the arc side of the expanded passage 22 and arranged along the arcs of the body 11 and the lid 12 is formed between the interior portion 11B of the body 11 and the lid 12.

Therefore, the highly viscous paint P fed from the coating gun G held by the robot arm 57 (see fig. 8) to the inlet pipe 31 at a predetermined pressure is introduced into the inlet passage 21 of the coating nozzle 10 and guided from the inlet passage 21 to the enlarged passage 22.

Here, the enlarged passage 22 has a space volume which is wider in the width direction than the opening at the lower end of the introduction passage 21 and is wider than the introduction passage 21, a slit entrance 23B of the slit passage 23 which is extremely smaller than the enlarged passage 22 is opened between the interior portion 11B of the body portion 11 and the lid portion 12 on the distal end portion side of the enlarged passage 22, and the thickness direction of the lower end of the enlarged passage 22 is a size which is sufficiently larger than the opening of the slit entrance 23B. That is, the width in the direction (thickness direction) perpendicular to the width direction of the slit passage 23 is extremely smaller than the width in the direction (thickness direction) perpendicular to the width direction of the lower end of the enlarged passage 22.

Therefore, the high-viscosity paint P introduced from the introduction passage 21 into the enlarged passage 22 is expanded in the width direction toward the distal end side by the enlarged passage 22, and is sent to the slit entrance 23b of the slit passage 23 while reducing the flow rate. At this time, the flow path of the high-viscosity paint P introduced from the introduction passage 21 into the enlarged passage 22 is expanded, and the flow path is narrowed by the slit passage 23 toward the outlet (slit discharge port 23a) from which the high-viscosity paint P is discharged, so that the high-viscosity paint P from the introduction passage 21 temporarily stays in the enlarged passage 22. Therefore, the internal pressure of the high-viscosity dope P is easily released by the enlarged passage 22, the variation in the internal pressure and viscosity is made uniform, and the high-viscosity dope P is pushed out toward the slit entrance 23 b. Therefore, the highly viscous paint P can be discharged from the slit outlet 23a of the slit passage 23 with a small variation in pressure, and therefore, unevenness in paint can be prevented and the smoothness of the coating film PL can be ensured. That is, even if the highly viscous paint P fed into the introduction pipe 31 varies in pressure distribution, flow rate, viscosity, and the like, the variation can be corrected by the enlarged passage 22, and the smoothness of the coating film PL can be stabilized.

In particular, in the coating nozzle 10 of the present embodiment, as shown in fig. 3 and 4, the slit passage 23 is not disposed in an extension portion extending in the axial direction (plumb direction) from the lower end of the introduction passage 21 provided in the exterior portion 11A constituting the main body portion 11 toward the expansion passage 22, but the slit passage 23 is disposed at a position shifted (offset) from the longitudinal extension portion of the introduction passage 21 extending in the longitudinal direction. That is, the opening of the slit entrance 23b of the slit passage 23 is present on the arc side of the enlarged passage 22 at a position shifted from the extension line in the longitudinal direction of the introduction passage 21.

Therefore, the highly viscous paint P introduced into the introduction passage 21 flows down and flows through the slit entrance 23b of the slit passage 23 so as not to advance straight forward in the plumb direction, but flows down with its flow direction (direction) easily changed. That is, as compared with the case where the slit passage 23 is provided on the extension line in the longitudinal direction of the introduction passage 21, the trajectory of the high viscosity paint P from the introduction passage 21 toward the slit passage 23 can be made longer and is more likely to receive resistance. Therefore, as compared with the case where the slit passage 23 is provided on the extension line in the longitudinal direction of the introduction passage 21, the high-viscosity dope P heading from the introduction passage 21 to the slit passage 23 is easily decelerated, and the unevenness of the flow velocity distribution can be reduced. Therefore, even if the variation in internal pressure and viscosity is further promoted to be uniform in the enlarged passage 22 and the highly viscous paint P fed into the introduction pipe 31 varies in pressure distribution, flow rate, viscosity, and the like, the paint unevenness can be further prevented and the smoothness of the coating film PL can be improved. Further, the high-viscosity paint P is decelerated, whereby the spread of the high-viscosity paint P discharged from the slit discharge port 23a of the slit passage 23 is suppressed, and the spread in the width direction is reduced.

In the coating nozzle 10 of the present embodiment, the lower arc side of the enlarged passage 22 having a substantially fan-like trapezoidal shape, in particular, the lower arc of the through hole 22B of the interior portion 11B into which the high-viscosity paint P is fed toward the slit entrance 23B of the slit passage 23, has a shape in which the corners on both end portions in the width direction are chamfered without any corner (a shape bent into a rounded corner shape). In other words, the radius of curvature of the arc of the slit entrance 23b extending in an arc shape is not constant but gradually changes, and the gap between the slit entrance 23b and the slit discharge opening 23a in the slit passage 23 is widened on both end portions in the width direction.

Accordingly, the high-viscosity paint P passing through the slit passage 23 is subjected to a larger resistance at the end portion side in the width direction of the slit passage 23 than at the center side in the width direction, and the flow velocity is decelerated, so that the high-viscosity paint P discharged from both end portions in the width direction of the slit discharge port 23a of the slit passage 23 is difficult to be discharged to a distant position, and the spread of the high-viscosity paint P discharged from the slit discharge port 23a of the slit passage 23 can be suppressed, and the degree of spread in the width direction can be reduced.

Furthermore, the opening shape of the slit outlet 23a of the slit passage 23 of the present embodiment, that is, the shape of the outlet for discharging the high-viscosity paint P is such that the opening at the center in the width direction is large and the end b in the width direction is directed as shown in fig. 3₁、b₂The side opening is gradually reduced. The opening of the slit outlet 23a is formed in a symmetrical shape in the width direction, and a line of bilateral symmetry, not shown, of the slit outlet 23a coincides with a line of bilateral symmetry, not shown, of the lower end opening of the introduction passage 21.

Here, if the width direction of the slit outlet 23a is set as the slit width L, the opening dimension (length) of the slit width L is set asThe slit width Lt is the slit width Lt and the arc b of the slit outlet 23a formed in an arc shape₁、b₂The chord length of the straight line distance of the connection is equivalent.

When the opening degree in the thickness direction (direction parallel to the coating direction) perpendicular to the slit width L is defined as the slit width W, the opening dimension (length, interval, gap) of the slit width W perpendicular to the slit width L is constant at the center portion 23aa in the range of about 1/3 of the slit width Lt from the center position in the width direction of the slit discharge opening 23a to both sides, and the slit width W is defined as the slit width W₁A rectangle is presented. On the other hand, the slit longitudinal width W₁The end portions 23ab on both sides of the constant center portion 23aa face the end portions b in the width direction of the slit outlet 23a₁、b₂The opening dimension of the slit longitudinal width W gradually decreases and changes at the end b of the slit outlet 23a in the width direction₁、b₂A slit longitudinal width W with the smallest opening size is formed₂(W₁＞W₂)。

That is, as shown in fig. 3, in a range of about 1/3 times the slit width Lt from the center of the slit discharge opening 23a in the width direction to both sides, the opposing sides of the slit discharge opening 23a extending in the width direction are parallel to each other and the interval between the opposing sides is constant, that is, the length of the slit longitudinal width W is constant, and this portion is defined as the center portion 23 aa. The length of the slit longitudinal width W of the central portion 23aa is defined as the slit longitudinal width W₁The length of the slit width L is defined as the slit width L₁. In fig. 3, both ends of the center portion 23aa in the width direction are a₁、a₂。

In addition, on both left and right sides (outside of the central portion 23aa) of the slit outlet 23a in the width direction, the side of the interior portion 11B side extending in the width direction in a straight line among the opposite sides extending in the width direction constituting the slit outlet 23a, and the side of the cover portion 12 side opposite thereto are extended from the end portion a₁、a₂Towards the end b₁、b₂The side close to the inner part 11B is inclined, and the interval between the opposite sides is from the end part a₁、a₂Side end b₁、b₂This portion is gradually reduced to the end 23 ab. Further, the end b of the end 23ab₁、b₂The length of the slit longitudinal width W is set as the slit longitudinal width W₂The length of the slit width L of the end 23ab is defined as the slit width L₂. Slit longitudinal width W₁The maximum opening dimension of the slit longitudinal width W₂Is the minimum opening dimension of the slit longitudinal width W.

The opening dimension of the slit width L is Lt ═ L₁+2L₂In the present embodiment, is L₁＞L₂. Thus, even when the coating film PL is applied in the width direction, the film thickness can be made uniform without excessive coating. For the sake of caution, as described above, the slit width Lt is not the arc length of the slit outlet 23a formed in an arc shape, but is an arc b₁、b₂Straight-line distance of connection, i.e. arc b₁、b₂The chord length of (c).

Thus, the slit outlet 23a of the present embodiment has an opening shape in which a central portion 23aa having a constant slit longitudinal width W is provided on the central side in the width direction and a side a in the width direction is provided from both sides in the width direction₁、a₂From the two ends b₁、b₂The longitudinal width W of the slit changes toward the end b₁、b₂A tapered end 23 ab.

As a result, as shown in fig. 7, the high-viscosity paint P is discharged thick from the coating nozzle 10 toward the center in the width direction of the slit discharge port 23a, which is a discharge port of the high-viscosity paint P, and the high-viscosity paint P is discharged gradually thinner toward both ends in the width direction. That is, the high-viscosity paint P is discharged with a substantially constant thickness at the center side in the width direction of the slit discharge port 23a, while being discharged with a thickness gradually decreasing toward the end portions at both end sides in the width direction. Therefore, when the coating of the predetermined line is finished and the next line (next line) is coated so that the end portions are overlapped (laterally overlapped) in the width direction of the coating film PL, if the coating is performed so that the portions where the thickness of the high-viscosity paint P changes thinly overlap each other, the coated portions do not protrude and swell unnecessarily, and the coated portions can be prevented from being thickened and raisedThe thickness increase of the portion coated on the center side where the thickness is constant can be suppressed. Therefore, the unevenness of the coating film PL to be coated can be reduced to achieve planarization, and the film thickness can be made uniform. In particular, when the convex portion is coated when the concave-convex surface of the coated surface 40 is coated, the coated portion is less likely to interfere with other members by suppressing an increase in the thickness of the coated portion. Preferably, the slit longitudinal width W is set₂Set as the slit longitudinal width W₁In the range of 0.4 to 0.6 times of the thickness of the coating film PL, the difference in film thickness between the coated portion and the other portion can be further reduced, and the coated coating film PL is excellent in flatness.

The inventors of the present invention have made experiments to prepare various shapes and configurations of application nozzles and have carried out application experiments of the high-viscosity paint P in order to reduce the fluctuation of the application pattern width PW due to the change in the distance from the spray gun, the discharge amount, and the temperature, and as a result, paid attention to the degree of spreading of the high-viscosity paint P discharged from the slit discharge port 23a with respect to the slit passage 23 having a shape in which the dimension in the width direction from the arc-shaped slit entrance 23b toward the arc-shaped slit discharge port 23a is enlarged. Further, with respect to the slit passage 23, there are found: if the arc-like degree of curvature (curvature) of the slit outlet 23a on the wide side is greater than the slit width Lt which is the opening size of the slit width L of the slit outlet 23a, that is, the two end portions b of the slit outlet 23a₁、b₂Connected circular arc b₁b₂When the relation of the chord length Lt of (a) is within a predetermined range, the spread of the high-viscosity paint P discharged from the opening surface of the slit discharge port 23a in the width direction in a radial shape is suppressed, and the high-viscosity paint P can be sprayed onto the coated surface 40 with the degree of diffusion of the high-viscosity paint P discharged from the slit discharge port 23a in the width direction reduced, so that the coating distance h (gun distance h) dependency, the discharge amount dependency, and the temperature dependency of the coating pattern width PW can be eliminated.

That is, according to the experimental study of the inventors of the present application, the discharge opening 23a is formed by a circular arc (arc b) facing the slit discharge opening₁、b₂) The radius of curvature R of the slit discharge port 23a and the slit width Lt of the slit discharge port 23a, i.e., the opposite ends b of the slit discharge port 23a₁、b₂Chord of connected circular arcs (chord b)₁、b²) The ratio of the chord length Lt of (a) is set to 70. ltoreq. Lt/R100. ltoreq. 130, and radial expansion and width-directional diffusion of the high-viscosity paint P discharged from the slit discharge port 23a until reaching the coated surface 40 are suppressed, that is, the high-viscosity paint P discharged from the slit discharge port 23a is suppressed from being expanded in width and diffused simultaneously in a radial shape, and the direction of the high-viscosity paint P approaches the direction of linear travel.

Referring to fig. 6, in the conventional coating nozzle (see the left column of fig. 6), since the high viscosity paint P discharged from the slit discharge port 23a is blown onto the coating surface 40 so as to spread in the width direction, that is, until the high viscosity paint P reaches the coating surface 40, the coating pattern width PW depends on the pressure and the fluid resistance of the high viscosity paint P passing through the slit discharge port 23 a. Therefore, if the pressure of the high-viscosity paint P passing through the slit outlet 23a is increased and the viscosity is decreased, the high-viscosity paint P discharged from the slit outlet 23a is likely to spread greatly in the width direction, and the radial spreading and the degree of spreading in the width direction can be increased. In other words, the application pattern width PW can be enlarged in accordance with the pressure and viscosity of the high-viscosity paint P, and the desired application pattern width PW can be adjusted by changing the discharge amount and temperature of the high-viscosity paint P. Therefore, the application pattern width PW is likely to vary greatly due to changes in the temperature and viscosity of the high-viscosity paint P, which are affected by the discharge amount and the fluid resistance due to the pressure control. Further, since the high-viscosity paint P discharged from the slit discharge port 23a is diffused in the width direction to a large extent, the coating pattern width PW of the coating film PL coated on the coated surface 40 varies greatly depending on the coating distance h.

In contrast, according to the shape of the slit passage 23 of the present embodiment in which the relationship between the curvature radius R and the chord length Lt of the arc of the slit discharge port 23a is defined in the range of Lt/R × 100 (%) -70 to 130, the high-viscosity paint P discharged from the slit discharge port 23a is blown onto the coated surface 40 without greatly spreading in the width direction (see the right column of fig. 6). That is, since the slit passage 23 is shaped such that the degree of diffusion in the width direction of the high-viscosity paint P discharged from the slit discharge port 23a is reduced by defining the relationship between the curvature radius R of the arc of the opposed slit discharge port 23a and the chord length Lt in the range of Lt/R × 100 (%) -70 to 130, the application pattern width PW is less likely to be affected by the pressure and the fluid resistance of the high-viscosity paint P passing through the slit discharge port 23 a. Therefore, the application pattern width PW is not easily changed even by a change in the temperature or viscosity of the high-viscosity paint P due to the discharge amount or the fluid resistance by the pressure control. Further, since the high-viscosity paint P discharged from the slit discharge port 23a has a small degree of radial spread, that is, spread in the width direction, and the direction of the high-viscosity paint P discharged from the slit discharge port 23a is close to the direction of linear travel, the coating distance h hardly affects the coating pattern width PW, and the coating pattern width PW is hardly varied even when the coating distance h is changed.

Here, according to the experimental study of the inventors of the present application, the arc (arc b) at the opposing slit exit 23a₁b₂) When the relationship between the curvature radius R and the chord length Lt is Lt/R × 100 (%) > 130, the degree of spreading in the width direction of the high-viscosity paint P discharged from the slit discharge port 23a, that is, the degree of spreading of the application pattern width PW with respect to the slit width Lt, is large, and the high-viscosity paint P is easily discharged to a distant place. Therefore, when the pressure of the high-viscosity paint P passing through the slit outlet 23a is high and the viscosity is low, the high-viscosity paint P discharged from the slit outlet 23a is likely to spread widely in the width direction, and the application pattern width PW is widened widely as compared with the case where the pressure of the high-viscosity paint P is low and the case where the viscosity is high. Further, when the pressure of the high-viscosity paint P is high and the viscosity is low, the high-viscosity paint P discharged from the slit discharge port 23a is greatly spread in the width direction, and therefore the application pattern width PW is greatly expanded as the application distance h becomes larger.

On the other hand, if Lt/R × 100 (%) < 70, the coating pattern width PW is insufficient, and it is difficult to obtain a coating pattern width PW of preferably 50 to 100mm and more preferably 60 to 90mm from the viewpoint of efficiency and productivity.

Therefore, if the relation between the radius of curvature R of the arc with respect to the slit discharge opening 23a and the chord length Lt is 70 Lt/R × 100 (%) < 130, the degree of spreading in the width direction of the high-viscosity paint P, that is, the degree of spreading of the application pattern width PW with respect to the slit width Lt becomes small while securing the predetermined application pattern width PW, and the high-viscosity paint P is not easily discharged to a far place, and therefore, it is difficult to vary the application pattern width PW in accordance with the application distance h. Further, if the relation between the radius of curvature R of the arc of the discharge opening 23a and the chord length Lt is 70 Lt/R × 100 (%). ltoreq.130, it is difficult to expand the application pattern width PW due to the pressure and viscosity of the high-viscosity paint P, and a predetermined application pattern width PW can be secured regardless of the pressure and viscosity of the high-viscosity paint P passing through the discharge opening 23a, and the application pattern width PW is not easily changed even if the discharge amount and temperature are changed.

Further, according to experimental studies by the present inventors, it is preferable that the arc (arc b) is an arc (curved line) with respect to the slit outlet 23a₁b₂) The central angle theta of the angle is within the range of 80-110 degrees. If the central angle θ of the arc with respect to the slit discharge port 23a is too small, the coating pattern width PW is insufficient, and a predetermined pattern width PW of 50 to 100mm cannot be obtained. On the other hand, if the central angle θ of the arc with respect to the slit discharge port 23a is too large, the high-viscosity paint P discharged from the slit discharge port 23a spreads more in the width direction, and a pattern crack is generated. Further, since the degree of diffusion in the width direction of the high-viscosity paint P is large, the coating distance h, the discharge amount, and the coating pattern width PW when the temperature changes are large in the high-viscosity paint P having a low material viscosity.

If the central angle θ of the arc with respect to the slit discharge port 23a is in the range of 80 to 110 °, a predetermined coating pattern width PW can be secured, and pattern cracks are less likely to occur. Further, the shear rate is, for example, 9400S at 0.1 to 1.5 Pa.S/20 ℃ (shear rate^-1Measurement at/20 ℃) during application of the highly viscous paint P having a viscosity, fluctuation of the application pattern width PW due to changes in the gun distance, discharge amount, and temperature is stably suppressed.

Here, an example of the coating nozzle 10 according to the present embodiment will be specifically described.

The coating nozzles 10 according to examples 1 to 5 and the coating nozzles according to comparative examples 1 to 2 were produced by changing the dimensions and shapes of the slit outlet 23a, and various coating experiments of the high-viscosity coating material P were performed. The design contents of each example and comparative example are shown in the upper stage of table 1.

TABLE 1

As shown in table 1, in the coating nozzles 10 according to examples 1 to 5, the minimum length W of the slit longitudinal width W of the slit outlet 23a was set to be the minimum length W₂I.e. both ends b in the width direction₁、b₂The slit longitudinal width W of the opening size (length) of the slit longitudinal width W₂In examples 1 to 5, all are W₂0.3mm, the maximum length W of the slit longitudinal width W₁That is, the slit longitudinal width W which is the opening dimension (length) of the slit longitudinal width W of the central portion 23aa in the width direction₁In examples 1 to 3 and 5, W is used as₁0.5mm, W in example 4₁＝0.6mm。

Here, according to the experimental study of the present inventors, the shear rate when the high-viscosity paint P passes through the slit outlet 23a is 5000 to 20000s^-1In the right and left ranges, it was confirmed that smoothness of the coating film PL and good coating film appearance were ensured, and at this time, the shear rate was varied depending on the opening size (length) of the slit width W. Conventionally, the discharge amount of a high-viscosity paint P such as a vibration damping material for a vehicle body is about 300 to 10000 cc/min when slit coating is performed. Therefore, in order to ensure a predetermined shear rate even in a high discharge rate region of 8000 cc/min or more, smoothness and good quality of the coating film PLThe inventors of the present invention have studied the ideal value of the opening dimension of the slit width W and found that the shear rate of the high-viscosity paint P is increased when the slit width W is decreased, and conversely, the shear rate of the high-viscosity paint P is decreased when the slit width W is increased, and the slit width W is preferably the maximum length W thereof in order to secure a predetermined shear rate₁Is of minimum length W₂In the range of 1.5 to 2.5 times. That is, according to experimental studies of the inventors of the present application, with respect to W₂0.3mm, if W₁Since the maximum length W of the slit width W can ensure a predetermined shear rate and ensure smoothness and good appearance of the coating film PL when set to 0.5mm to 0.6mm₁W is set in examples 1 to 3 and 5₁0.5mm, set as W in example 4₁＝0.6mm。

Further, according to experimental studies by the present inventors, it was confirmed that the slit lateral width L of the central portion 23aa of the portion where the slit longitudinal width W is constant with respect to the slit lateral width Lt of the slit discharge opening 23a (the arc chord length Lt of the slit discharge opening 23a) is constant with respect to the slit lateral width Lt of the slit discharge opening 23a₁When the ratio (c) is increased, the increase in the thickness of the overlapping portion (overlap portion D) when the highly viscous paint P is applied to the end portion in the width direction is increased, and the uniformity of the coating film PL is decreased. Accordingly, the slit width L of the slit outlet 23a is preferably set to be larger than the width L of the slit₁The ratio of the width Lt of the slit to the width Lt of the slit is L₁the/Lt × 100 (%) -is in the range of 33 to 45. If 33. ltoreq.L₁if/Lt × 100 (%). ltoreq.45, the balance between the transverse slit width L of the portion where the slit width W parallel to the coating direction is constant (the central portion 23aa) and the portion where the slit width W parallel to the coating direction changes (the end portion 23ab) is obtained, and it is preferable that the width D of the applied portion D (see fig. 7) is increased or decreased, and the coating film PL is substantially flat, and it is difficult for the applied portion D to protrude or sink. More preferably, L is₁the/Lt × 100 (%) -is in the range of 34 to 40.

In examples 1 to 5 and comparative examples 1 to 2, the slit width L of the slit outlet 23a₁The ratio of the slit width Lt to the slit width Lt is 34% to 35% with respect to Lt/Rx100 (%), and the slit width of the slit discharge opening 23a is adjusted to be larger thanL of L₁/L₂The ratio of (a) to (b) is set to be substantially the same.

In examples 1 to 3, all the slit lateral widths L of the slit outlets 23a were set to L, L being 49mm or less₁＝17mm，L₂16mm, the slit opening area is 21.3mm²Further, an arc (arc b) corresponding to the slit outlet 23a₁b₂) The central angle of (e) is 90 °, and only the radius of curvature R of the circular arc with respect to the slit discharge opening 23a is different. That is, the radius of curvature R is 40mm in example 1, 50mm in example 2, and 60.5mm in example 3. Accordingly, the relation between the radius of curvature R of the arc of the slit discharge opening 23a and the chord length Lt is 122.5% Lt/R × 100 in example 1, 98.0% Lt/R × 100 in example 2, and 81.0% Lt/R × 100 in example 3.

In the coating nozzle 10 according to example 4, the slit width Lt and the slit width W of the slit outlet 23a are set to be equal to each other₁The slit opening area is larger than that in examples 1 to 3, and is also larger than that in examples 1 to 3. That is, in example 4, the slit width L was 52mm, L₁＝18mm，L₂17mm, the slit opening area is 26.1mm²The center angle θ is 90 °. In example 4, the radius of curvature R of the arc of the slit outlet 23a is larger than in examples 1 to 3, and the radius of curvature R is 64.54 mm. Thus, in example 4, Lt/R × 100 is 80.6%.

Further, in the coating nozzle 10 according to example 5, the slit width Lt of the slit outlet 23a is larger than those of examples 1 to 4, and the slit opening area is also larger than those of examples 1 to 4. That is, in example 5, the slit width L was 62.4mm, where L is the width Lt of the slit₁＝21.6mm，L₂20.4mm, the slit opening area is 27.12mm²The center angle θ is 90 °. In example 5, the radius of curvature R of the arc of the slit outlet 23a is larger than in examples 1 to 4, and the radius of curvature R is 77.5 mm. Thus, in example 5, Lt/R × 100 is 80.5%.

On the other hand, in examples 1 to 5, the slit length was larger than that of comparative example 1 corresponding to the conventional productThe width W is large and the slit width L is small. That is, in comparative example 1, the slit width L was 43mm, L₁＝15mm，L₂The slit has a longitudinal width W of 14mm₁＝0.8mm，W₂0.4mm, the slit opening area is 28.8mm²The center angle θ is 90 °. In comparative example 1, the radius of curvature R of the arc of the slit outlet 23a was smaller than in examples 1 to 5, and the radius of curvature R was 30 mm. Thus, in comparative example 1, Lt/R × 100 was 143.3%.

In comparative example 2 corresponding to other conventional products, the slit vertical width W was larger and the slit horizontal width L was smaller than those of comparative example 1 to example 5, but larger than that of comparative example 1. That is, in comparative example 2, the slit width L was 22.6mm, where L is the width Lt₁＝7.8mm，L₂7.4mm, and the slit longitudinal width W is W₁＝0.8mm，W₂0.4mm, the slit opening area is 15.12mm²The center angle θ is 100 °. In comparative example 2, the radius of curvature R of the arc of the slit outlet 23a was smaller than in examples 1 to 5 and comparative example 1, and the radius of curvature R was 15 mm. Thus, in comparative example 2, Lt/R × 100 was 150.7%.

Fig. 5 shows, as a precaution, the configuration of the application nozzle 10 according to embodiments 1 to 3 in which the slit width Lt (the chord length Lt of the arc with respect to the slit discharge opening 23a) of the slit discharge opening 23a is the same length and the radius of curvature R of the arc with respect to the slit discharge opening 23a is different.

In each of the examples and comparative examples, the center point C of the arc on the center side of the slit entrance 23b of the opposing slit passage 23 was set to₁And the center point C of the arc of the opposed slit outlet 23a₁In all of the examples and comparative examples, the ratio of the radius of curvature R of the arc facing the slit outlet 23a to the radius of curvature of the arc facing the center of the slit inlet 23b was set to be substantially the same. That is, in all of the examples and comparative examples, the length of the center of the slit passage 23 was the same. For example, the radius of curvature of the arc on the center side of the slit entrance 23b is in the range of 0.85 to 0.95 of the radius of curvature R of the arc on the slit discharge port 23a, and the slit entrance 23b and the slit discharge port 23a are located at the center in the width directionThe distance between the slit outlets 23a is 3 to 8 mm.

As shown in fig. 5, in examples 1 to 3, the slit width Lt (the length Lt of the arc relative to the slit discharge opening 23a) of the slit discharge opening 23a was set to 49mm, and the slit width Lt was set to the arc relative to the slit discharge opening 23a (the arc b)₁b₂) The center angle θ of (1) is 90 °, but the radius of curvature R is 40mm in example 1, 50mm in example 2, and 60.5mm in example 3, so that the curvature (degree of curvature) of the arc of the slit outlet 23a of example 1 is the largest and the arc is sharply curved in examples 1 to 3. At this time, the discharge pressure at which the highly viscous paint P is discharged from the slit discharge port 23a is, for example, 5Pa to 25 Pa.

Then, various coating experiments of the high viscosity paint P were performed using the coating nozzles 10 of examples 1 to 5 and the coating nozzles of comparative examples 1 to 2 having such a configuration.

Specifically, the fluctuation of the coating pattern width PW was examined when the coating distance h (hereinafter referred to as the spray gun distance h), the discharge amount, and the paint temperature were varied variously. In this experiment, the high-viscosity paint P was a paint of a coating-type vibration-damping material for automobiles, and the material viscosity was 1.0 pas/20 ℃ (shear rate was 9400 s)^-1Measured at 20 ℃).

First, regarding the gun distance h, the measurement of the coating pattern width PW when the distance h between the coated surface 40 and the tip of the coating nozzle 10 is 50mm, the measurement of the coating pattern width PW when the distance h between the coated surface 40 and the tip of the coating nozzle 10 is 75mm, and the measurement of the coating pattern width PW when the distance h between the coated surface 40 and the tip of the coating nozzle 10 is 100mm were performed, and differences of the coating pattern widths when the distance h between the coated surface 40 and the tip of the coating nozzle 10 was changed to 50mm, 75mm, and 100m were observed. In this case, as experimental conditions, the discharge amount was set to 8000 cc/min, the spray gun speed was set to 500mm/s, and the paint temperature was set to 25 ℃.

When the difference in the coating pattern width PW was within 6mm when the gun distance h was set to 50mm, 75mm, and 100m, it was judged as acceptable (o) as a result of obtaining a stable coating pattern width PW regardless of the gun distance even when the gun distance h was changed. In particular, if the difference in the coating pattern width PW is within 6mm, it is possible to obtain a stable coating pattern width PW with respect to the coated surface 40 having a curved surface, irregularities, or the like, even if the position of the coating gun G is changed without following the height difference of the coated surface 40. Therefore, even if fine adjustment of the robot is not performed to make the gun distance h constant, it is possible to obtain coating with less variation in the coating pattern width PW. On the other hand, if the difference in the coating pattern width PW exceeds 6mm, it is determined to be defective (x) as a result of high gun distance dependency of the coating pattern width PW, large variation in the coating pattern width PW due to variation in the gun distance h, and large variation in the coating pattern width PW.

Further, regarding the discharge amount, the measurement of the coating pattern width PW at a discharge amount of 6000 cc/min, the measurement of the coating pattern width PW at a discharge amount of 8000 cc/min, and the measurement of the coating pattern width PW at a discharge amount of 10000 cc/min were performed, and differences of the coating pattern widths PW at discharge amounts of 6000 cc/min, 8000 cc/min, and 10000 cc/min were observed. In this case, as experimental conditions, the spray gun distance h was set to 50mm, the spray gun speed was set to 500mm/s, and the paint temperature was set to 25 ℃.

When the difference in the coating pattern width PW was within 20mm when the discharge amount was changed to 6000 cc/min, 8000 cc/min, and 10000 cc/min, it was judged as acceptable (∘) as a result of obtaining a stable coating pattern width PW in which the coating pattern width PW did not greatly change depending on the discharge amount or the influence of the discharge amount. On the other hand, when the difference in the coating pattern width PW exceeds 20mm, it is determined as a failure (x) as a result of high discharge amount dependency of the coating pattern width PW and large fluctuation of the coating pattern width PW due to the discharge amount.

With respect to the coating temperature, the measurement of the coating pattern width PW at 15 ℃, the measurement of the coating pattern width PW at 25 ℃ and the measurement of the coating pattern width PW at 35 ℃ were carried out, and the difference in the coating pattern width PW at 15 ℃, 25 ℃ and 35 ℃ was observed when the coating temperature was changed. In this case, as experimental conditions, the discharge amount was set to 8000 cc/min, the lance speed was set to 500mm/s, and the lance distance h was set to 50 mm.

When the difference in the coating pattern width PW was within 5mm when the coating material temperature was changed to 15 ℃, 25 ℃ and 35 ℃, it was judged as acceptable (∘) as a result of obtaining a stable coating pattern width PW in which the coating pattern width PW did not greatly vary depending on the coating material temperature or the influence of temperature. On the other hand, if the difference in the coating pattern width PW exceeds 5mm, the coating pattern width PW is determined to be defective (x) as a result of high coating material temperature dependency of the coating pattern width PW and large fluctuation of the coating pattern width PW due to temperature.

Here, in the coating process of the coating type vibration damping material for an automobile, in order to eliminate coating margin (in order to prevent a gap between the coating films PL) where the high viscosity paint P is not applied to the coating surface 40 from the viewpoint of vibration damping performance, it is preferable to perform excessive coating with respect to the coating area such that the coating is performed at the end in the width direction in the row of the coating films PL, and at this time, there is a risk that the coated portion will interfere with the surrounding members if the thickness of the coated portion increases due to the coating of the end in the width direction of the coating film PL.

Then, coating in which the coating films PL are overlapped at the edges in the width direction was performed using the coating nozzles 10 of examples 1 to 5 and the coating nozzles of comparative examples 1 to 2, and an increase in film thickness when the coating film PL was applied was observed. Specifically, as shown in fig. 7, coating is performed in which the coating films PL are arranged in the width direction, but in this case, when the next column is coated with respect to the coating film PL in the front column without providing a gap between the adjacent columns of the front column and the next column (the next column), coating is performed so as to overlap with the end portion in the width direction of the coating film PL in the front column. Then, the film thickness t on the center S side of the front or rear row of coating films PL is performed with the width D of the portion D where the coating films PL are overlapped at the edge in the width direction (hereinafter, overlapping portion D) set to 10mm and 20mm₁Film thickness t of the overlapping portion D₂Comparison of (1), ObservationFilm thickness t of overlap portion D₂Film thickness t on the center S side of the coating film PL for the front row or the sub-row₁An increase in thickness of.

Further, as experimental conditions in this case, the uniform discharge amount was 8000 cc/min, the spray gun distance was 50mm, the spray gun speed was 500mm/s, and the paint temperature was 25 ℃.

The measurement results of the coating pattern width PW when the spray gun distance, the discharge amount, and the temperature were changed, and the increase in the applied film thickness when the coating film PL was applied by arranging the coating films in the width direction and applied by a predetermined width were measured, as shown in the lower stage of table 1.

As shown in table 1, in comparative example 1 and comparative example 2, which are conventional products, the slit width L of the slit outlet 23a was smaller than in examples 1 to 5, and the radius of curvature R of the arc of the slit outlet 23a was smaller than in examples 1 to 5, and was Lt/R × 100> 130%. Therefore, as shown in fig. 6, the high viscosity paint P vertically discharged from the opening surface of the slit discharge port 23a has a large degree of diffusion in the width direction, and the application pattern width PW is enlarged due to an increase in discharge amount, that is, an increase in pressure, so that the difference in application pattern width PW when the discharge amount is changed to 6000 cc/min, 8000 cc/min, and 10000 cc/min exceeds 20mm, and the application pattern width PW greatly fluctuates due to the change in discharge amount, and the discharge amount dependency of the application pattern width PW is extremely high.

In other words, since the application nozzles of comparative examples 1 and 2, which are conventional products, have a large application pattern width PW due to an increase in the discharge amount, the highly viscous coating material P discharged from the slit discharge port 23a can be radially and largely expanded in the width direction by the pressure (discharge amount), and the application pattern width PW can be controlled by increasing or decreasing the discharge amount.

In the nozzle shapes according to comparative examples 1 and 2 in which Lt/R × 100> 130% as described above, the high viscosity paint P discharged from the slit discharge port 23a spreads greatly in the radial direction, and therefore the fluid resistance, i.e., the viscosity, of the high viscosity paint P decreases, and the application pattern width PW also greatly expands. Therefore, when the viscosity decreases with an increase in temperature, the highly viscous paint P discharged from the slit outlet 23a spreads greatly, and the application pattern width PW expands greatly, so that the difference in the application pattern width PW when the paint temperature changes to 15 ℃, 25 ℃, and 35 ℃ exceeds 5 mm. That is, the coating pattern width PW greatly fluctuates due to a change in the temperature of the coating material, and the temperature dependency of the coating pattern width PW is extremely high.

Further, in comparative example 1 and comparative example 2 in which Lt/R × 100> 130%, as shown in fig. 6, the degree of spreading of the high-viscosity paint P discharged from the slit discharge port 23a radially spread in the width direction is large, and the high-viscosity paint P from the slit discharge port 23a radially spreads greatly, so that the variation of the application pattern width PW according to the gun distance h is large. That is, when the difference in the application pattern width PW exceeds 6mm when the spray gun distance h is changed to 50mm, 75mm, and 100m, the high-viscosity paint P discharged from the slit discharge port 23a spreads more greatly in the width direction as the spray gun distance h becomes larger (longer), and the application pattern width PW spreads greatly. In particular, in comparative example 2, since the degree of radial diffusion of the high-viscosity coating material P is large, pattern cracks are generated when the spray gun distance h is large (long). That is, the variation of the coating pattern width PW due to the change of the gun distance h is large, and the coating pattern width PW is greatly affected by the gun distance h. As described above, in comparative example 1 and comparative example 2, since the highly viscous paint P discharged from the slit discharge port 23a spreads radially and largely, the application pattern width PW changes largely in accordance with the gun distance h, and the distance dependency of the application pattern width PW is extremely high.

In contrast, in the coating nozzles 10 of examples 1 to 5, since the relationship between the radius of curvature R of the arc with respect to the slit discharge port 23a and the chord length Lt is 70 ≦ Lt/R × 100 ≦ 130, as shown in fig. 6, the degree of spreading of the high-viscosity paint P discharged perpendicularly from the opening surface of the slit discharge port 23a in the width direction is reduced, and the high-viscosity paint P discharged from the slit discharge port 23a is less likely to spread in the width direction, and the spreading is suppressed, and the discharge is close to the straight line. Further, by forming a slit shape in which the relation between the radius of curvature R and the chord length Lt of the arc facing the slit discharge port 23a is 70. ltoreq. Lt/R.ltoreq.100 (%). ltoreq.130, the spreading of the high-viscosity paint P discharged from the slit discharge port 23a is suppressed, and the application pattern width PW is not dependent on the pressure or the fluid resistance any more. That is, when the slit shape is set to have an Lt/R × 100 in the range of 70% to 130%, the high viscosity paint P is less likely to spread in the width direction, and the application pattern width PW is less likely to be affected by pressure and fluid resistance.

As described above, in the coating nozzle 10 of examples 1 to 5, the relationship between the radius of curvature R of the arc with respect to the slit discharge port 23a and the chord length Lt is controlled to be in the range of 70 ≦ Lt/R × 100 ≦ 130 with respect to the slit shape, and the diffusion of the high-viscosity paint P discharged from the slit discharge port 23a is suppressed, so that, as shown in fig. 6, the high-viscosity paint P discharged from the slit discharge port 23a does not diffuse so much even when the discharge amount is increased, and therefore, the coating pattern width PW does not spread so much, and even when the discharge amount is changed to 6000 cc/min, 8000 cc/min, and 10000 cc/min, the difference in the coating pattern width PW is 17mm or less, and a stable coating pattern width having a very small variation in the coating pattern width PW can be obtained.

Further, even if the viscosity of the high-viscosity paint P passing through the slit outlet 23a is lowered due to the rise of the paint temperature, the high-viscosity paint P discharged from the slit outlet 23a does not spread greatly in the width direction, and therefore, the application pattern width PW does not spread greatly, and even if the temperature is changed to 15 ℃, 25 ℃, and 35 ℃, the difference in the application pattern width PW is extremely small and 5mm or less. That is, even if the temperature changes, the variation of the coating pattern width PW is very small, and a stable coating pattern width PW can be obtained.

Further, since the slit shape is controlled within the range of Lt/R × 100 of 70% to 130%, as shown in fig. 6, the high viscosity paint P discharged from the slit discharge port 23a does not spread out greatly in the width direction but approaches the linear advancing line, and therefore, the variation in the application pattern width PW due to the gun distance h is extremely small, and even if the gun distance h is changed to 50mm, 75mm, or 100m, the application pattern width PW does not spread out, and therefore, the difference in the application pattern width PW is 6mm or less, and a stable application pattern width PW can be obtained.

In particular, as is clear from comparison of examples 1 to 5, the smaller the ratio Lt/R, the smaller the variation in the spray gun distance, the discharge amount, and the coating pattern width PW when the coating material temperature is changed. This is because the smaller the slit lateral width Lt of the slit discharge port 23a, the smaller the spread in the width direction of the high-viscosity paint P discharged from the slit discharge port 23a, and the larger the curvature radius R of the arc of the slit discharge port 23a, the smaller the degree of curvature (curvature) of the slit discharge port 23a, and therefore, the smaller the spread in the width direction of the high-viscosity paint P discharged from the slit discharge port 23 a. That is, the smaller the ratio Lt/R, the more the high-viscosity paint P discharged from the slit discharge port 23a does not spread to a distance, and the smaller the spread of the high-viscosity paint P in the width direction, the higher the straight-ahead performance of the high-viscosity paint P discharged from the slit discharge port 23a, and the less the influence of the pressure or the flow rate. This can be confirmed from the fact that the coating pattern width PW is smaller than in examples 1 and 2 in example 3 in which the ratio Lt/R is smaller than in examples 1 and 2. Further, as the ratio Lt/R is smaller, the higher the high-viscosity paint P discharged from the slit discharge port 23a, the more the high-viscosity paint P is, the more the discharge pattern becomes close to a straight line without being spread in the width direction, and therefore, the variation in the application pattern width PW due to the gun distance h is eliminated. However, if the ratio Lt/R is too small, the coating pattern width PW is insufficient, and it is difficult to obtain a coating pattern width PW of preferably 50 to 100mm and more preferably 60 to 90mm from the viewpoint of efficiency and productivity. According to experimental studies by the inventors of the present application, it was confirmed that a predetermined pattern width PW can be ensured when Lt/R × 100> > 70%. More preferably, the ratio Lt/R x 100 is 75% or more and 125% or less.

As is clear from a comparison of examples 1 to 3, the application pattern width PW can be adjusted by changing the ratio Lt/R within the range of 70% to 130% based on the application nozzles 10 having Lt/R × 100 within the range of 70% to 130%, and a desired target PW can be easily selected by selecting a slit nozzle having Lt/R ratio within the range of 70% to 130% based on Lt/R × 100.

That is, according to the application nozzle 10 of the present embodiment in which the relation between the radius of curvature R of the arc facing the slit discharge port 23a and the chord length Lt is set in the range of Lt/R × 100 to 70% to 130% with respect to the slit shape, by selecting nozzles having different application pattern shapes in which the ratio of Lt/R is changed in the range of Lt/R × 100 to 70% to 130%, it is possible to control a desired pattern width corresponding to the shape and the application range of the surface 40 to be coated, unlike the conventional case in which the application pattern width is controlled by the discharge amount, and therefore, it is possible to stabilize the application pattern width PW without depending on fine control in the coating equipment 50 that adjusts the discharge amount, the coating distance, and the coating temperature in order to obtain the desired application pattern width PW as a target. That is, there is no need for a coating control technique requiring high precision in setting and adjusting the discharge amount, the coating distance h (spray gun distance h), and the paint temperature, which are extremely fine (small units), with precision. Therefore, it is possible to simplify the highly accurate and high-performance equipment such as a constant displacement pump capable of stabilizing the discharge amount and a heat exchanger capable of finely adjusting the paint temperature, for example, the coating equipment 50 for performing extremely fine setting and adjustment of the discharge amount and the paint temperature and maintaining the same constant. Further, since the robot that performs the ultrafine setting and adjustment of the coating distance h or maintains the coating distance h constant is not required to perform the ultrafine control, the program input means for the robot teaching (guidance) can be simplified.

As described above, according to the coating nozzle 10 of the present embodiment, the relation between the radius of curvature R of the arc opposed to the slit discharge port 23a and the chord length Lt is set in the range of Lt/R × 100 to 70% to 130%, so that the spread of the high-viscosity coating material P discharged from the slit discharge port 23a in the width direction is reduced, and therefore, it is difficult to spread the discharge pattern by pressure as in the conventional art, and the coating pattern width PW is not dependent on pressure or fluid resistance. That is, the application pattern width PW is free from discharge amount dependency and temperature dependency by pressure control, and can be adjusted as desired by designing a slit shape in which the ratio Lt/R is changed. Further, since the high-viscosity paint P discharged from the slit discharge port 23a has a discharge pattern in which the spread in the width direction is small and the paint approaches the straight line, the coating pattern width PW gets rid of the gun distance dependency, and the variation in the coating pattern width PW due to the coating distance h is suppressed. That is, the variation of the coating pattern width PW with respect to the variation of the coating distance h until the high-viscosity paint P reaches the coated surface 40 is extremely small, and the influence of the coating distance h on the coating pattern width PW is small. Therefore, it is possible to obtain a stable coating pattern width PW for the coated surface 40 having a curved surface, unevenness, or the like, even if the position of the coating gun G is changed without following the level difference of the coated surface 40. That is, fine adjustment of the robot for keeping the gun distance h constant can be simplified, and coating with less variation in the coating pattern width PW can be realized.

Further, as shown in the lower stage of table 1, in the coating nozzles of comparative examples 1 and 2, when the leading row and the following row are applied at the ends in the width direction by coating with the coating films PL arranged in the width direction, when the width D (overlap D) of the overlap portion D of the applied portion is 10mm, the thickness t on the center S side of the coating film PL of the leading row or the following row shown in fig. 7 is compared with the thickness t on the center S side of the coating film PL of the leading row or the following row₁Thickness t of the overlapping portion D₂The amount of (B) increased was + 30% in comparative example 1 and + 50% in comparative example 2. Further, when the width D of the overlapping portion D is 20mm, the thickness t of the coating film PL on the center S side with respect to the front row or the sub-row shown in FIG. 7₁Thickness t of the overlapping portion D₂The amount of (B) increased was + 35% in comparative example 1 and + 60% in comparative example 2.

In contrast, according to the coating nozzles 10 of examples 1 to 5, when the width D (the overlap amount D) of the overlap portion D of the coated portion is 10mm, the thickness t of the coating film PL on the center S side with respect to the front row or the rear row shown in fig. 7 is set to be larger₁Thickness t of the overlapping portion D₂Is suppressed to + 22% or less, and when the width D of the overlap portion D is 20mm, the thickness t of the front or rear row of the coating film PL on the center S side is set to be equal to the thickness t of the coating film PL on the front or rear row shown in FIG. 7₁Thickness t of the overlapping portion D₂Is also suppressedLess than + 25%. Therefore, according to the coating nozzles 10 of examples 1 to 5, even when the leading row and the trailing row are coated at the ends in the width direction by the coating in which the coating films PL are arranged in the width direction, the increase in the film thickness of the overlapping portion D is small. Moreover, the coated portion hardly bulges even if it varies somewhat regardless of the repetition width of the coated portion. Therefore, the film thickness uniformity is excellent, and there is no risk of interference with surrounding members even when the convex portion of the coated surface 40 having the concavity and convexity is coated.

In the coating nozzles 10 of examples 1 to 5, the slit discharge port 23a is formed in an opening shape such that the length of the slit vertical width W is constant at the center portion 23aa and is directed from the end portion 23ab to the end portion b₁、b₂The paint P is discharged thick at the center of the slit discharge port 23a and thinly at both ends in the width direction by gradually changing the slit longitudinal width W. Thus, the thickness of the coating film PL in the row is smaller on the end side than on the center S side, and the film thickness is not excessively thick even if the coating is performed on the end side. In the coating nozzles 10 of examples 1 to 5, when the relation between the radius of curvature R of the arc facing the slit discharge port 23a and the chord length Lt is set to a range of Lt/R × 100 of 70% to 130%, the spreading of the high-viscosity coating material P discharged from the slit discharge port 23a in the width direction is reduced, and therefore, the coating material unevenness is less likely to occur in the width direction of the coating film PL. That is, since the coating film PL is not greatly spread in the width direction, the coating film PL applied to the coated surface 40 has less unevenness and unevenness of the coating material in the width direction, and is excellent in flatness. Thus, even if the width of the overlap portion varies somewhat, the difference in film thickness between the applied portion D and the center S side is small, and the thickness t of the overlapping portion D is small₂Thickness t of the central S side of the coating film PL with respect to the front row or the sub-row₁The amount of increase of (c) is decreased.

As described above, the coating nozzle 10 of the present embodiment is a coating nozzle 10 in which the introduction passage 21, the expansion passage 22, and the slit passage 23 are provided, and the introduction passage 21 is formed in a substantially cylindrical shape extending in the longitudinal directionA highly viscous paint P is introduced, the expanding passage 22 is expanded in a width direction perpendicular to a painting direction from an opening at a lower end of the introducing passage 21, has a space volume larger than that of the introducing passage 21, and is formed into a substantially fan-shaped trapezoid, the slit passage 23 is communicated with the expanding passage 22 and is arranged below the expanding passage 22 along an arc on an arc side expanded in the width direction of the expanding passage 22, the slit passage 23 is a slit-shaped gap having a width smaller than that of the lower end of the expanding passage 22 in a direction perpendicular to the width direction (thickness direction), wherein the slit passage 23 has a slit outlet 23a extended in an arc shape for discharging the highly viscous paint P and a slit inlet 23b extended in an arc shape on the expanding passage 22 side opposite thereto and into which the highly viscous paint P enters from the expanding passage 22 side, and is formed into a substantially arc shape (substantially fan-shaped trapezoid) having a width enlarged from the slit inlet 23b toward the slit outlet 23a, when the arc (arc b) of the slit outlet 23a is to be opposed₁b₂) R, and an arc (arc b) of the slit outlet 23a₁b₂) When the chord length of (c) is Lt (slit width Lt), the relation between R and Lt is in the range of Lt/R × 100 (%) -70 to 130.

Therefore, according to the coating nozzle 10 of the present embodiment, the high-viscosity paint P discharged from the slit discharge port 23a is reduced in expansion in the width direction and the degree of diffusion is reduced by the shape of the slit passage 23 in which the relationship between the radius of curvature R of the arc facing the slit discharge port 23a and the chord length Lt of the arc facing the slit discharge port 23a is defined to be Lt/R × 100 (%) -70 to 130. That is, according to the shape of the slit passage 23 defined in the range of Lt/R × 100 (%) -70 to 130, the spreading in the width direction of the high-viscosity paint P discharged in the direction substantially perpendicular to the opening surface of the slit discharge port 23a is suppressed, and the direction of the high-viscosity paint P discharged from the slit discharge port 23a is not radially extended in the width direction toward the coated surface 40 side but is in a nearly linear forward direction. Therefore, the variation in the coating pattern width PW due to the coating distance h (the gun distance h) is reduced.

In addition, in the shape of the slit passage 23 in which the relationship between the curvature radius R of the arc facing the slit discharge port 23a and the chord length Lt of the arc facing the slit discharge port 23a is defined as Lt/R × 100 (%) -70 to 130, the high viscosity paint P discharged from the slit discharge port 23a is less likely to spread in the width direction, and therefore the application pattern width PW is less likely to be affected by the pressure or the fluid resistance of the high viscosity paint P discharged from the slit discharge port 23 a. That is, since the discharge pattern of the high-viscosity paint P from the slit discharge port 23a is hard to spread in the width direction due to the shape of the slit passage 23 defined in the range of Lt/R × 100 (%) -70 to 130, the discharge pattern does not expand even if the pressure is increased, the application pattern width PW is hard to change even if the discharge amount by the pressure control is changed, and the application pattern width PW is hard to change even if the temperature and viscosity of the high-viscosity paint P are changed.

As described above, according to the coating nozzle 10 of the present embodiment, the variation in the coating pattern width PW due to the influence of the discharge amount, the coating distance h, and the paint temperature is suppressed, and the coating pattern width PW is stabilized.

In the coating nozzle 10 of the above embodiment, the arc (arc b) of the slit outlet 23a is directed to₁b₂) The radius of curvature R of (a) is constant in all regions, and the arc of the slit discharge opening 23a extending in an arc shape is a perfect arc shape, but in the case of carrying out the present invention, an arc having a changing radius of curvature, for example, an elliptical arc shape in which the arc shape gradually changes may be used. In this case, the radius of curvature R of the arc of the slit outlet 23a is an average value of the maximum value and the minimum value of the variable radius of curvature, and if the radius of curvature R of the average value is within the above-mentioned predetermined range, the application pattern width PW is less likely to vary even if the temperature and viscosity of the high-viscosity paint P change.

In particular, the arc (arc b) of the slit outlet 23a of the slit passage 23 is defined as the arc₁b₂) When the central angle θ of (a) is in the range of 80 ° to 100 °, the coating pattern width PW is not excessively expanded and no pattern crack is generated. Further, the variation of the coating pattern width PW due to the discharge amount, the coating distance h, and the coating temperature is extremely small, and the predetermined pattern width PW can be ensured more stably.

Further, according to the coating nozzle 10 of the above embodiment, since the slit passage 23 is disposed at a position shifted from a position at which the opening position of the lower end of the introduction passage 21 extends in the plumb direction, the flow path of the high-viscosity paint P can be lengthened as compared with the case where the slit passage is disposed on an extension line extending the opening position of the lower end of the introduction passage 21 in the plumb direction, and therefore the high-viscosity paint P fed from the introduction passage 21 to the slit inlet 23b of the slit passage 23 is easily decelerated, and unevenness in the flow velocity distribution is suppressed. Therefore, in the expanding passage 22, the uniformity of the variation in the internal pressure or viscosity is further promoted, and even if the high-viscosity paint P fed into the introducing pipe 31 varies in pressure distribution, flow rate, viscosity, and the like, the unevenness of the paint on the coating film PL can be prevented, and the smoothness of the coating film PL can be improved.

However, in the case of carrying out the present invention, the slit passage 23 may be disposed at a position on the central axis of the introduction passage 21, may be disposed at an extended portion extending in the plumb direction at the opening position of the lower end of the introduction passage 21, or may be disposed at a position slightly shifted from the central axis.

Further, according to the coating nozzle 10 of the above embodiment, since the slit passage 23 is widened in the width direction from the slit entrance 23b toward the slit exit 23a, by spreading the coating material from the slit entrance 23b toward the slit exit 23a, a predetermined coating pattern width PW of, for example, 50 to 100mm can be secured, and the coating film PL discharged from the slit exit 23a can be made thin, and excessive coating can be prevented. For example, the coating film PL may have a film thickness of 250 to 1000 μm.

Further, according to the coating nozzle 10 of the above embodiment, since the slit vertical width W of the slit outlet 23a of the slit passage 23 is made constant at the central portion 23aa in the width direction, the slit vertical width W extends from both sides of the central portion 23aa to both end portions b in the width direction₁、b₂The coating material P is discharged thick at the center of the slit outlet 23a and has both ends b in the width direction₁、b₂On the other hand, the dope P is thinly discharged. Therefore, even if the overcoat is performed on the end portion side in the width direction of the coating film PLThe thickness t of the coated part D₂The increase in (b) is also suppressed.

In addition, the slit vertical width W of the slit outlet 23a is formed at both ends b in the width direction₁、b₂Since the thickness of the coating film PL is gradually reduced, the thickness t of the coated portion D of the coating film PL can be made smaller by setting the region width D to be coated on the end portion side of the coating film PL on which one layer of coating is performed₂The thickness t of the coating film near the center S side of the coating film discharged from the portion where the slit vertical width W is constant₁A thickness t of a substantially uniform thickness on the center S side of the one-layer coating₁The thickness t of the coating can be set arbitrarily even in the finished state of the uniform coating film PL₂。

In particular, by defining the relation between the curvature radius R and the chord length Lt of the arc of the slit discharge port 23a as a slit shape in the range of Lt/R × 100 (%) -70 to 130, the spread of the coating material P discharged from the slit discharge port 23a in the width direction can be suppressed, and the coating film PL coated on the coated surface 40 is less likely to have coating unevenness in the width direction, and is excellent in smoothness. Therefore, for example, even when the end portion side in the width direction of the coating film PL is coated with a width in which the width D of the coated portion D is 10mm to 20mm, the variation in the difference in film thickness between the coated portion D and the center S side is small, and the coated coating film PL is formed with a more uniform film thickness.

The application nozzle 10 of the above embodiment is constituted by the body portion 11 and the lid portion 12 as a separate member, and further, the body portion 11 is constituted by a separate member of the exterior portion 11A and the interior portion 11B, and these exterior portion 11A, the interior portion 11B, and the lid portion 12 are assembled by the embedded screws 28.

In the coating nozzle 10 of the above embodiment, the slit passage 23 is formed between the inner portion 11B and the lid portion 12.

Thus, even when the slit passage 23 is clogged with foreign matter and the application pattern is disturbed, the foreign matter can be easily removed and the clogging can be eliminated by disassembling the internal portion 11B and the lid portion 12. That is, maintenance is easy, and a coating pattern having a predetermined width can be stably secured.

Here, since the slit passage 23 for discharging the high viscosity paint P in a thin film sheet shape is a slit-like gap, abrasion of the wall surface defining the slit passage 23 is likely to be serious. Thus, in the application nozzle 10 of the above embodiment, the exterior part 11A, the interior part 11B, and the lid part 12 are formed in a three-layer structure, the main body part 11 is constituted by the exterior part 11A and the interior part 11B which are separate members, and the slit passage 23 is defined by the interior part 11B and the lid part 12. Thus, even when the wear of the inner wall surface around the slit passage 23 deteriorates, only the interior portion 11B and the lid 12 need be replaced, which results in a low cost. Further, since the inner portion 11B and the lid portion 12 are made of wear-resistant materials and inexpensive materials are used for the outer portion 11A, they can be manufactured at low cost.

However, in the case of implementing the present invention, the application nozzle 10 may be configured by 1 member, or may be configured by 2 members of the main body portion 11 and the lid portion 12, and the slit passage 23 may be provided between the main body portion 11 and the lid portion 12, so that the clogging is eliminated by the decomposition of the main body portion 11 and the lid portion 12, and the maintenance is facilitated. The introduction passage 21, the enlarged passage 22, and the slit passage 23 may be formed on the same plane, and may be configured to be plane-symmetrical with respect to the same plane. This facilitates the manufacture of the coating nozzle 10.

The application nozzle 10 of the present embodiment is described as being applied to a vehicle body such as an automobile, but is not limited to the field of automobiles, and can be applied to interior and exterior coating of trains, ships, and the like, buildings, and the like. In particular, in the slit coating using the coating nozzle 10 of the above embodiment, since the coating material is discharged in a film form without being atomized, the coating material does not bounce or overflow from the coated surface 40. Here, as the high-viscosity paint P, in addition to vibration damping applications, a paint for light touch resistance applications is used, for example, as a primer layer or a protective layer for application to a back part of a chassis, a wheel cover part, or the like of an automobile.

The configuration, shape, number, material, size, connection relationship, assembly method, and the like of other parts of the application nozzle 10 are not limited to the above-described embodiments. In addition, since all the numerical values recited in the embodiments of the present invention do not represent critical values, and some numerical values represent ideal values suitable for implementation, the implementation thereof is not denied even if the numerical values are slightly changed.

Description of the reference numerals

10 coating nozzle

21 introduction path

22 expanding the pathway

23 slit passage

23a slit outlet

23b slit entrance

23aa center part