阅读说明：本技术 充气轮胎的制造方法及其制造装置 (Method and apparatus for manufacturing pneumatic tire ) 是由 中东大树 于 2021-03-01 设计创作，主要内容包括：充气轮胎的制造方法及其制造装置。提高轮胎品质。充气轮胎的制造方法包含：使气囊(10)在放置于硫化模具(2)的外部的生胎(T)的轮胎内腔内进行初始膨胀的工序(S2)；将生胎(T)与初始膨胀后的气囊(10)一起设置于硫化模具(2)中的工序(S5)；以及在闭合硫化模具(2)后,使初始膨胀后的气囊(10)进一步膨胀而将生胎(T)按压于硫化模具(2)的工序(S6)。(A method and an apparatus for manufacturing a pneumatic tire. The quality of the tire is improved. The method for manufacturing a pneumatic tire includes: a step (S2) for initially inflating the bladder (10) in a tire cavity of a green tire (T) placed outside the vulcanization mold (2); a step (S5) for setting the green tire (T) in the vulcanization mold (2) together with the initially inflated bladder (10); and a step (S6) for further expanding the initially expanded bladder (10) to press the green tire (T) against the vulcanizing mold (2) after the vulcanizing mold (2) is closed.)

1. A method for manufacturing a pneumatic tire, comprising the steps of:

inserting an air bag from a bead opening part of a green tire placed outside a vulcanization mold, and initially expanding the air bag in a tire inner cavity;

disposing the green tire in a curing mold with the initially inflated bladder; and

after the vulcanization mold is closed, the initially expanded bladder is further expanded to press the green tire against the vulcanization mold.

2. The manufacturing method of a pneumatic tire according to claim 1,

the method for manufacturing a pneumatic tire includes a step of holding the green tire by a loader,

the step of holding is performed before the step of initial expansion.

3. The manufacturing method of a pneumatic tire according to claim 2,

the method for manufacturing a pneumatic tire includes a step of detaching the loader from the green tire,

the step of detaching is performed before the step of disposing.

4. The manufacturing method of a pneumatic tire according to claim 3,

the method of manufacturing a pneumatic tire includes a step of controlling an expansion amount of the bladder that performs the initial expansion in the tire cavity,

the step of controlling is performed before the step of detaching.

5. The manufacturing method of a pneumatic tire according to claim 4,

the step of controlling includes a step of measuring an inflation amount of the airbag.

6. The manufacturing method of a pneumatic tire according to claim 4 or 5,

the step of controlling includes a step of adjusting an inflated state of the airbag.

7. An apparatus for manufacturing a pneumatic tire, wherein,

the apparatus for manufacturing a pneumatic tire includes a lower mold, an upper mold located at a position separated from the lower mold, a moving device, and a control device,

the lower die has: a molding surface for holding the green tire in the lateral direction from the lower side; and an air bag which is capable of being inflated in the inner cavity of the green tire through a bead opening of the green tire placed on the molding surface,

the moving means moves the lower mold or the upper mold so that the lower mold abuts the upper mold to form a vulcanization space of the green tire,

the control means causes the bladder to initially inflate within a tire cavity of the green tire placed on the lower mold before the moving means moves the lower mold or the upper mold.

8. The manufacturing apparatus of a pneumatic tire according to claim 7,

the apparatus for manufacturing a pneumatic tire further includes a loader for holding the green tire in the lateral direction from the upper side.

9. The manufacturing apparatus of a pneumatic tire according to claim 8,

the loader comprises measuring means for measuring the amount of expansion of the green tyre after the initial expansion.

10. The manufacturing apparatus of a pneumatic tire according to claim 9,

the measuring device is a displacement meter of the non-contact type.

Technical Field

The present invention relates to a method and an apparatus for manufacturing a pneumatic tire.

Background

Patent document 1 listed below describes a tire vulcanizer for vulcanizing a green tire and a method for vulcanizing a green tire using the tire vulcanizer. The tire vulcanizer includes an upper mold disposed at a tire vulcanizing position, a lower mold having an air bladder, a moving device for moving the lower mold between a tire supplying position and a tire vulcanizing position, and a tire supplying device for supplying the green tire to the lower mold. In the vulcanizing method, first, the green tire held by the tire supplying device is mounted on the lower mold disposed at the tire supplying position. Next, the tire supply device is detached from the green tire. Then, the green tire and the lower mold are moved to the tire vulcanization position by the moving device and set on the upper mold. Finally, the bladder of the lower mold is inflated to vulcanize the green tire.

Patent document 1: japanese patent laid-open publication No. 2004-122407

Disclosure of Invention

In order to cure the tire with high accuracy, it is necessary to appropriately inflate the bladder. However, unexpected inflation of the air bag may occur due to positional deviation between the air bag and the green tire, or due to inflation in a state where the wrinkles are not fully stretched when the air bag is folded. In such a case, the tire after vulcanization molding may have a problem that the tire quality may be degraded due TO deterioration of uniformity, in addition TO formation of wrinkles of the bladder on the inner cavity surface of the tire or protrusion (L/TO) of rubber from the bead.

The present invention has been made in view of the above circumstances, and a main object thereof is to provide a method and an apparatus for manufacturing a pneumatic tire, which can improve tire quality.

The present invention is a method for manufacturing a pneumatic tire, including the steps of: inserting an air bag from a bead opening part of a green tire placed outside a vulcanization mold, and initially expanding the air bag in a tire inner cavity; disposing the green tire in a curing mold with the initially inflated bladder; and further expanding the initially expanded bladder to press the green tire against the vulcanizing mold after closing the vulcanizing mold.

In the method for manufacturing a pneumatic tire according to the present invention, it is preferable that the method includes a step of holding the green tire by a loader, and the step of holding is performed before the step of initial inflation.

In the method for manufacturing a pneumatic tire according to the present invention, it is preferable that the method further includes a step of detaching the loader from the green tire, and the step of detaching is performed before the step of installing.

In the method for manufacturing a pneumatic tire according to the present invention, it is preferable that the method includes a step of controlling an inflation amount of the bladder that performs the initial inflation in the tire inner cavity, and the step of controlling is performed before the step of removing.

In the method of manufacturing a pneumatic tire according to the present invention, it is preferable that the step of controlling includes a step of measuring an inflation amount of the bladder.

In the method of manufacturing a pneumatic tire according to the present invention, it is preferable that the step of controlling includes a step of adjusting an inflated state of the bladder.

The present invention is a manufacturing apparatus of a pneumatic tire, including a lower mold, an upper mold located at a position separated from the lower mold, a moving device, and a control device, the lower mold having: a molding surface for holding the green tire in the lateral direction from the lower side; and an air bag that is expandable in the inner cavity of the green tire through a bead opening of the green tire placed on the molding surface, wherein the moving means moves the lower mold or the upper mold so that the lower mold and the upper mold abut each other to form a vulcanization space of the green tire, and the control means initially expands the air bag in the tire inner cavity of the green tire placed on the lower mold before the moving means moves the lower mold or the upper mold.

In the pneumatic tire manufacturing apparatus according to the present invention, it is preferable that the apparatus further includes a loader for holding the green tire in the lateral direction from the upper side.

In the pneumatic tire manufacturing apparatus according to the present invention, preferably, the loader includes a measuring device for measuring an amount of expansion of the green tire after the initial expansion.

In the pneumatic tire manufacturing apparatus according to the present invention, the measuring device is preferably a non-contact type displacement meter.

The method and apparatus for manufacturing a pneumatic tire according to the present invention can improve tire quality by adopting the above configuration.

Drawings

Fig. 1 is a sectional view schematically showing a manufacturing apparatus used in the method of manufacturing a pneumatic tire according to the present invention.

Fig. 2 (a) is a flowchart of the present embodiment, fig. 2 (b) is a flowchart of the holding step of fig. 2 (a), and fig. 2 (c) is a flowchart of the control step of fig. 2 (a).

Fig. 3 is a sectional view schematically showing a manufacturing apparatus in the second holding step of the present embodiment.

Fig. 4 is a sectional view schematically showing a manufacturing apparatus in the initial expansion step of the present embodiment.

Fig. 5 is a cross-sectional view schematically showing the vulcanizing device in the removal step of the present embodiment.

Fig. 6 is a cross-sectional view schematically showing a manufacturing apparatus in the setting step and the pressing step of the present embodiment.

Description of the reference symbols

2: vulcanizing the mold; 10: an air bag; s2: an initial expansion process; s5: setting; s6: a pressing step; t: and (4) building a green tire.

Detailed Description

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

The method for manufacturing a pneumatic tire according to the present invention (hereinafter, may be simply referred to as "manufacturing method") includes a step of forming a green tire T (shown in fig. 1) and a vulcanization step of vulcanizing the formed green tire T. A step of forming the green tire T (hereinafter, may be simply referred to as "green tire forming step") is a known method, and thus a detailed description thereof is omitted.

Fig. 1 is a cross-sectional view conceptually illustrating one embodiment of a pneumatic tire manufacturing apparatus (hereinafter, may be simply referred to as "manufacturing apparatus") 1 used in a vulcanization process of the present embodiment. The manufacturing apparatus 1 of the present embodiment includes a vulcanizing mold 2, a moving device 3, and a control device 4. The manufacturing apparatus 1 may include a loader 5, for example.

In the present embodiment, the green tire T is laterally moved within the manufacturing apparatus 1 and is set in the vulcanizing mold 2. In the present specification, the "lateral direction" refers to a direction in which the tire axial direction of the green tire T is vertical. Thus, as shown in fig. 1, the lateral green tire T is divided into a first section T1, a second section T2, and a third section T3. The first portion T1 is, for example, a portion located radially outward of the tire from the maximum width position (not shown) of the tire after vulcanization. The second portion T2 is, for example, a portion located inward and upward in the tire radial direction from the first portion T1. The third portion T3 is, for example, a portion located radially inward of the tire from the first portion T1 and located below the second portion T2. In addition, the green tire T includes an upper bead opening portion T4 formed inside the second section T2 in the tire radial direction and a lower bead opening portion T5 formed inside the third section T3 in the tire radial direction. The upper bead opening portion T4 and the lower bead opening portion T5 include the tire rotation axis Tc of the green tire T. In the figure, the direction perpendicular to the drawing is indicated by an arrow Z.

The vulcanizing mold 2 of the present embodiment includes a lower mold 7 and an upper mold 8 located at a position separated from the lower mold 7. In the present embodiment, the lower die 7 abuts against the upper die 8 (shown in fig. 6). The lower mold 7 abuts against the upper mold 8 to form a vulcanization space K for vulcanizing the green tire T. In the present specification, the term "contact" means that two objects that can be separated collide and come into contact with each other.

In the present embodiment, the lower mold 7 includes: a molding surface (hereinafter sometimes referred to as "lower molding surface") 9 that holds the green tire T in the lateral direction from the lower side; and an airbag 10 that is inflatable in a tire cavity (hereinafter, sometimes simply referred to as "cavity") of the green tire T placed on the molding surface 9. The airbag 10 is formed of a known elastic material such as rubber.

The lower die 7 has, for example, a bag tube 11 of a known structure for housing the airbag 10. A supply line (not shown) for supplying a pressure medium made of a known high-pressure fluid such as steam or inert gas is connected to the bag tube 11 of the present embodiment. The airbag 10 is inflated by supplying the pressurized medium to the bag cartridge 11.

The lower mold 7 includes, for example, a lower split mold 12 forming the lower molding surface 9 and a lower plate 13 disposed below the lower split mold 12. The lower split mold 12 includes, for example, a heating device, not shown, for vulcanizing the third portion T3 of the green tire T. The lower split die 12 and the lower plate 13 have, for example, an opening portion for holding the bag barrel 11. In the present embodiment, the lower plate 13 is fixed to the lower base plate 14. As described above, the lower die 7 of the present embodiment has a known structure.

The upper mold 8 of the present embodiment is disposed above the lower mold 7. The upper mold 8 includes a molding surface (hereinafter, sometimes referred to as an "upper molding surface") 16 that covers the lateral green tire T from above and from the side, for example. The upper mold 8 includes, for example, a separable upper split mold 17 forming the upper molding surface 16 and an upper plate 18 disposed above the upper split mold 17. The upper assembling die 17 includes, for example, a heating device, not shown, for heating the first portion T1 and the second portion T2 of the green tire T. The upper plate 18 is held by a first moving device 20 described later, for example, so as to be movable up and down. As described above, the upper mold 8 of the present embodiment has a known structure.

The moving device 3 of the present embodiment is used to move the lower mold 7 or the upper mold 8 to form the vulcanization space K of the green tire T. The moving device 3 of the present embodiment includes a first moving device 20 for moving the upper mold 8 and a second moving device 21 for moving the lower mold 7. The moving device 3 is not limited to this form, and may be constituted by only the first moving device 20, for example.

The first moving device 20 of the present embodiment moves the upper mold 8 up and down (vertically). In the present embodiment, the first moving device 20 includes a support shaft 20a that holds and moves the upper plate 18 up and down. Such a first moving device 20 is formed of a known structure such as a ball screw or a telescopic cylinder structure.

The second moving device 21 of the present embodiment moves the lower mold 7 in the horizontal direction. The second moving device 21 linearly moves the lower base plate 14 toward a position below the upper mold 8 (hereinafter, may be referred to as a "vulcanization position a"), for example. Such a second moving device 21 is formed of a known structure such as a ball screw or a telescopic cylinder structure.

The loader 5 of the present embodiment has a function of moving the green tire T formed in the green tire forming step and mounting the green tire T on the lower mold 7. The loader 5 is constituted by, for example, a horizontal base plate 24 and a plurality of arm portions 25 projecting downward from the base plate 24. In the present embodiment, the substrate 24 is held to be movable three-dimensionally by a moving means of a known structure, not shown. The arm portion 25 has, for example, a bead holding device 25a of a known configuration that holds the second portion T2. In the present embodiment, the arm portion 25 holds the second portion T2 from the upper bead opening portion T4. In this way, the loader 5 of the present embodiment can suspend and move the green tire T. The loader 5 is not limited to this configuration, and may include a holding device (not shown) having a known structure for holding the green tire T on the molding surface 9 of the lower mold 7, for example.

In the present embodiment, the loader 5 has a measuring device 27, and the measuring device 27 measures an inflation amount (an initial inflation amount described later in the present embodiment) of the bladder 10 inflated in the tire cavity. The measuring device 27 is fixed to the substrate 24, for example. In the present embodiment, the measuring device 27 is preferably a non-contact type displacement meter. The measuring device 27 is more preferably a laser displacement meter that measures a distance by irradiating a laser beam to a measurement target, for example. Such a measuring device 27 can output, for example, measurement data d relating to the distance to the object to be measured as an electric signal.

The control device 4 is configured, for example, as a computer. The control device 4 includes, for example, a memory for storing measurement data d and the like, a cpu (central Processing unit) for executing various arithmetic Processing, information Processing and the like, a storage device such as a magnetic disk, a display unit for displaying Processing results and the like, an operation unit for operating the measurement device 27, and the like. The storage device stores, for example, a program in advance. In the present embodiment, the program has the following functions: the bladder 10 is initially inflated within the tire cavity of the green tire T placed on the lower mold 7 before the lower mold 7 or the upper mold 8 is moved by the moving device 3. The above-described routine may also have a function of controlling the amount of expansion of the bladder 10 and a function of controlling the amount of heating of the vulcanizing mold 2, for example. Further, for example, the measuring device 27 may also have a function of controlling the amount of inflation of the airbag 10.

Next, a vulcanization step of the manufacturing method using the manufacturing apparatus 1 will be described. Fig. 2 (a) is a flowchart of the vulcanization step. As shown in fig. 2 (a), the vulcanization step of the present embodiment includes an initial expansion step S2, a setting step S5, and a pressing step S6. The vulcanization process includes, for example, a holding process S1, a control process S3, and a removal process S4.

Fig. 2 (b) is a flowchart of the holding step S1. As shown in fig. 2 (b), the holding step S1 of the present embodiment includes: a first holding step S1a in which the loader 5 holds the green tire T; and a second holding step S1b of holding the green tire T held by the loader 5 by the lower mold 7. Fig. 1 shows the first holding step S1 a.

As shown in fig. 1, in the present embodiment, in the first holding step S1a, the second section T2 of the green tire T is held by the bead holder device 25a of the loader 5. Thereby, the green tire T is held in a suspended state by the loader 5 and can move three-dimensionally.

Next, the second holding step S1b is performed. Fig. 3 is a sectional view illustrating the second holding step S1 b. As shown in fig. 3, in the second holding step S1B of the present embodiment, the lower mold 7 is moved to a position separated from the upper mold 8 in the horizontal direction (hereinafter, sometimes referred to as "green tire receiving position B") by the second moving device 21. Then, in the second holding step S1B, the green tire T held by the loader 5 is moved to the green tire receiving position B. Then, for example, the loader 5 descends and the third portion T3 of the green tyre T is retained on the lower forming surface 9. Thus, in the present embodiment, the green tire T is held by the loader 5 and the lower mold 7.

Next, the initial expansion step S2 is performed. Fig. 4 is a sectional view illustrating the initial expansion process S2. As shown in fig. 4, in the initial inflation step S2, a pressurized medium is first supplied into the bladder tube 11 from the supply line, not shown, and the bladder 10 is inserted into the tire cavity from the lower bead opening T5 to inflate the bladder 10. In the initial inflation step S2, the green tire T can be visually observed. Therefore, for example, even when the green tire T is positionally deviated by the inflation of the bladder 10, it can be easily relocated to an appropriate position. In addition, such a desired inflation can eliminate wrinkles and the like caused by the accommodation of the airbag 10 into the bag tube 11. This can suppress the unexpected expansion of the bladder 10, which occurs in the vulcanization mold 2, for example, and therefore, the tire quality can be improved in the manufacturing method of the present embodiment. The pressure P1 of the pressure medium in the initial expansion step S2 is preferably 30KPa or less, for example.

Next, the control step S3 is performed. Fig. 2 (c) is a flowchart of the control step S3. As shown in fig. 2 (c), the control step S3 of the present embodiment includes a step S3a of measuring the inflation amount of the airbag 10 and a step S3b of adjusting the inflated state of the airbag 10.

As shown in fig. 4, in the present embodiment, in the measurement step S3a, the inflation amount X of the airbag 10 that is initially inflated in the green tire T is measured. In the measurement step S3a of the present embodiment, the measurement device 27 measures the expansion amount X. The inflation amount X is measured as, for example, the distance in the vertical direction between the base plate 24 and the airbag 10 exposed from the upper bead opening portion T4. In the case of using a laser displacement meter as the measuring device 27, for example, the measurement data d relating to the measured expansion amount X is converted into an electric signal and output to the control device 4.

The amount of inflation X is preferably measured at a predetermined plurality of positions of the airbag 10, for example. The amount of expansion X is preferably measured including the position on the tire rotation axis Tc, for example. The expansion amount X may be measured at equal intervals in the circumferential direction of the green tire T around the tire rotation axis Tc, for example.

The adjustment step S3b adjusts the inflated state of the airbag 10 based on the measured inflation amount X, for example. In the present embodiment, in the adjustment step S3b, the controller 4 controls the supply amount of the pressure medium by an unillustrated opening/closing valve or the like provided in the supply line to adjust the inflation amount of the airbag 10 so that the inflation amount X falls within a predetermined range. This enables the bladder 10 to be initially inflated uniformly in the inner cavity of the green tire T. Further, the green tire T can be set in an appropriate position with respect to the molding surface 9.

Next, the detaching step S4 is performed. Fig. 5 is a sectional view illustrating the detaching step S4. As shown in fig. 5, in the removing step S4 of the present embodiment, the loader 5 is removed from the green tire T. In the removal step S4, the initial inflation of the bladder 10 is maintained while the lower mold 7 is holding the green tire T. In the removal step S4, the loader 5 is separated from the green tire receiving position B in order to receive a new green tire (not shown) formed in the green tire forming step. In the removal step S4, the lower mold 7 and the green tire T are moved from the green tire receiving position B to the vulcanizing position a by driving the second moving device 21, for example. At this time, the green tire T is held by the initially inflated bladder 10, and therefore, the displacement from the lower mold 7 due to the movement can be suppressed.

Next, the setting step S5 is performed. Fig. 6 is a cross-sectional view illustrating the setting step S5 and the pressing step S6. As shown in fig. 6, in the setting step S5 of the present embodiment, the green tire T is set in the vulcanizing mold 2 together with the initially inflated bladder 10. In the setting step S5, the upper mold 8 is lowered by the first moving device 20, for example, and the green tire T is set in the vulcanization space K between the upper mold 8 and the lower mold 7. In the setting step S5 of the present embodiment, the lower split die 12 abuts against the upper split die 17 to form the closed vulcanization space K.

Next, the pressing step S6 is performed. The pressing step S6 of the present embodiment further expands the bladder 10 after the initial expansion to press the green tire T against the vulcanizing mold 2. The green tire T is vulcanized by heating the vulcanizing mold 2 by the heating device not shown. The pressure P2 of the pressure medium in the pressing step S6 is preferably 1.0MPa or more, and preferably 0.2MPa or less when the pressure medium is steam, and is preferably 1.5MPa or more, and preferably 2.5MPa or less when the pressure medium is nitrogen, for example.

While the above description has been made in detail with respect to the particularly preferred embodiments of the present invention, the present invention is not limited to the illustrated embodiments, and can be modified into various embodiments.

[ examples ] A method for producing a compound

A green tire was vulcanized using a manufacturing apparatus having the basic structure of fig. 1, and a tire after vulcanization (hereinafter referred to as "vulcanized tire") was tested for tire quality. The tire quality was confirmed by appearance test, uniformity test and dynamic balance test. In comparative example, a green tire was vulcanized in the same manner as in example except that the initial inflation step and the control step of the present embodiment were not performed. In each of examples and comparative examples, 5000 green tires were used, and an average value was calculated in each test.

< appearance test >

The occurrence of wrinkles caused by the bladder attached to the inner cavity surface of the vulcanized tire was confirmed by visual observation of the tester. The results are expressed as the ratio of the number of tires with wrinkles. The smaller the value, the better.

< uniformity test >

RFV (radial force variation) and LFV (lateral force variation) were measured using a uniformity tester according to JASO C607 (uniformity test method for automobile tires). The results are expressed as an index with the comparative example being 100. The smaller the value, the better.

< dynamic balance test >

Dynamic balance was measured using a dynamic balance tester. The results are expressed as an index with the comparative example being 100. The smaller the value, the better. The test results are shown in table 1.

[ TABLE 1 ]

	Comparative example	Examples
			Appearance test (ratio)	100	0
Rf V (index)	100	97
			L F V (index)	100	88
Dynamic balance (index)	100	94

It can be understood that the vulcanization methods of the examples are excellent in tire quality as compared with the vulcanization methods of the comparative examples.