阅读说明：本技术 涡旋流体机械以及涡旋构件的加工方法 (Scroll fluid machine and method of machining scroll member ) 是由 佐藤创 木全央幸 滨野真史 伊藤隆英 于 2019-01-07 设计创作，主要内容包括：在固定涡旋盘的齿顶形成有顶端密封槽(3d),其收纳有顶端密封件(7)。在与固定涡旋盘的壁体(3b)的齿顶角部(8)对置的回旋涡旋盘的壁体(5b)的根部的齿底角部(9)设置有阶梯部(9a)。顶端密封槽(3d)形成于比与阶梯部(9a)对置的位置靠壁体(3b)的厚度方向中心侧的位置。即,壁体(3b)的齿顶的堤宽度(Ta)比阶梯部(9a)的阶梯部宽度(Sw)大。(A tip seal groove (3d) is formed in the tooth tip of the fixed scroll, and a tip seal (7) is housed therein. A step (9a) is provided at a tooth bottom corner (9) at the root of a wall body (5b) of the orbiting scroll, said tooth bottom corner being opposed to a tooth top corner (8) of a wall body (3b) of the fixed scroll. The tip seal groove (3d) is formed at a position closer to the center side in the thickness direction of the wall body (3b) than a position facing the step portion (9 a). Specifically, the bank width (Ta) of the tooth tips of the wall body (3b) is greater than the step width (Sw) of the step (9 a).)

1. A scroll fluid machine includes:

a first scroll member having a first wall body of a spiral shape provided on a first end plate;

a second scroll member in which a second spiral wall body that meshes with the first wall body and performs orbital and revolving motion relative to the first wall body is provided on a second end plate disposed so as to face the first end plate; and

a tip seal provided in a groove formed in a tooth tip of the first wall and the second wall and contacting an opposing tooth bottom to seal a fluid,

wherein the content of the first and second substances,

a step portion is provided at a tooth bottom corner portion of a root portion of one of the walls facing a tooth top corner portion of the other wall,

the groove is formed closer to the center of the wall in the thickness direction than the position facing the step.

2. The scroll fluid machine according to claim 1,

the scroll fluid machine includes inclined portions in which a distance between facing surfaces of the first end plate and the second end plate that face each other continuously decreases from an outer peripheral side to an inner peripheral side of the first wall body and the second wall body, and the inclined portions are provided within a range of 180 ° or more around a center of a lap.

3. A method of processing a scroll member having an end plate and a spiral wall body provided in the end plate, and a groove portion for receiving a tip seal is provided in a tooth tip of the wall body,

the processing method of the scroll component comprises the following steps:

a first peripheral wall surface processing step of processing one peripheral wall surface of the wall body and an adjacent tooth bottom;

a second peripheral wall surface machining step of machining the other peripheral wall surface of the wall body and the adjacent tooth bottom; and

a groove processing step of forming the groove on a tooth top of the end plate,

a step is provided at a corner of a tooth bottom at a root of the wall body,

the groove is formed closer to the center of the wall in the thickness direction than the position facing the step.

4. The method of machining a scroll member according to claim 3,

the scroll member includes a wall inclined portion in which the height of the wall body continuously decreases from an outer circumferential side toward an inner circumferential side, and/or an end plate inclined portion in which the height of the end plate continuously increases from the outer circumferential side toward the inner circumferential side, and the wall inclined portion and the end plate inclined portion are provided within a range of 180 ° or more around the center of the lap.

5. A method of processing a scroll member having an end plate and a spiral wall body provided in the end plate, and having an inclined portion in which the height of the wall body from a tooth bottom to a tooth top continuously changes in a scroll direction, wherein,

the processing method of the scroll component comprises the following steps:

a first peripheral wall surface processing step of processing one peripheral wall surface of the wall body and an adjacent tooth bottom;

a second peripheral wall surface machining step of machining the other peripheral wall surface of the wall body and the adjacent tooth bottom;

a tooth bottom processing step of processing only a tooth bottom between the one peripheral wall surface and the other peripheral wall surface; and

a groove processing step of forming a groove in a tooth top of the end plate,

a step is provided at a corner of a tooth bottom at a root of the wall body,

the groove is formed closer to the center of the wall in the thickness direction than the position facing the step.

Technical Field

The present invention relates to a scroll fluid machine and a method of machining a scroll member.

Background

Conventionally, there is known a scroll fluid machine in which a fixed scroll provided with a wall body having a spiral shape at an end plate is engaged with an orbiting scroll to perform an orbiting motion, thereby compressing or expanding a fluid.

As such a scroll fluid machine, a so-called step scroll compressor as shown in patent document 1 is known. In the stepped scroll compressor, stepped portions are provided at positions along the spiral direction of the tooth crest and the tooth bottom surface of the spiral wall of the fixed scroll and the orbiting scroll, respectively, and the height of the outer peripheral side of the wall is higher than the height of the inner peripheral side with the stepped portions as boundaries. In the stepped scroll compressor, compression is performed not only in the circumferential direction of the wall body but also in the height direction (three-dimensional compression), and therefore, the displacement can be increased and the compressor capacity can be increased as compared with a normal scroll compressor (two-dimensional compression) having no stepped portion.

Disclosure of Invention

Problems to be solved by the invention

However, the stepped scroll compressor has a problem that fluid leakage at the stepped portion is large. Further, there is a problem that the strength is reduced by concentrating the stress on the root portion of the stepped portion.

In view of the above, the inventors have studied a case where a continuous inclined portion is provided instead of a step portion provided in a wall body and an end plate.

However, the inclined portion has a problem that the machining is more difficult than the machining of a flat surface. If the machining accuracy of the tooth bottom corner portion at the root of the wall body is lowered, a step portion may be formed at the tooth bottom corner portion and may contact the tip seal. When the tip seal is brought into contact across the step portion, a gap is generated between the tip seal and the tooth bottom, so that leakage of fluid occurs. In addition, there is a possibility that the wear excessively progresses due to the tip seal sliding with respect to the step portion. Further, there is a possibility that the performance of the scroll fluid machine is lowered.

Such a problem may occur not only in a scroll fluid machine having an inclined portion but also in a normal scroll compressor or a stepped scroll compressor having no stepped portion due to a machining error of a tooth bottom corner portion.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a scroll fluid machine and a method of machining a scroll member, in which a step portion formed at a tooth bottom corner portion is prevented from coming into contact with a tip seal.

Means for solving the problems

In order to solve the above problems, the following aspects are adopted in a scroll fluid machine and a method of machining a scroll member according to the present invention.

A scroll fluid machine according to an aspect of the present invention includes: a first scroll member having a first wall body of a spiral shape provided on a first end plate; a second scroll member in which a second spiral wall body that meshes with the first wall body and performs orbital and revolving motion relative to the first wall body is provided on a second end plate disposed so as to face the first end plate; and a tip seal that is provided in a groove formed in the tooth tips of the first wall and the second wall and that comes into contact with the opposing tooth bottoms to seal the fluid, wherein a step is provided at a tooth bottom corner portion of the root of the other wall that faces the tooth top corner portion of the one wall, and the groove is formed closer to the center side in the thickness direction of the wall than a position that faces the step.

In machining the tooth bottom, a step may be formed at a corner of the tooth bottom at the root of the wall body. When the tip seal is in contact across the step, there is a possibility that a gap is generated between the tip seal and the tooth bottom to cause leakage of fluid, and there is a possibility that the tip seal is worn.

Therefore, the groove portion is formed at a position closer to the center side in the thickness direction of the wall body than the position facing the stepped portion, so that the tip seal does not contact the stepped portion. This reduces fluid leakage from the gap between the tip seal and the step portion, and suppresses wear of the tip seal, thereby suppressing a reduction in performance of the scroll fluid machine.

The step provided at the corner of the tooth bottom also includes a step inevitably formed by machining.

In a scroll fluid machine according to an aspect of the present invention, the scroll fluid machine includes an inclined portion in which a distance between facing surfaces of the first end plate and the second end plate that face each other continuously decreases from an outer peripheral side to an inner peripheral side of the first wall body and the second wall body, and the inclined portion is provided in a range of 180 ° or more around a center of a lap.

Since the inclined portion is provided in which the distance between the facing surfaces of the first end plate and the second end plate decreases continuously from the outer peripheral side toward the inner peripheral side of the wall body, the fluid sucked from the outer peripheral side is compressed toward the inner peripheral side not only by the decrease in the compression chamber corresponding to the spiral shape of the wall body but also by the decrease in the distance between the facing surfaces between the end plates.

Since the inclined portion is more difficult to machine than a flat surface, machining accuracy of the root corner portion of the wall body may be reduced. If the machining accuracy of the tooth bottom corner portion is lowered, a step portion is generated in the tooth bottom corner portion.

For example, when one peripheral wall surface of the wall body and the adjacent tooth bottom are machined, and then the other peripheral wall surface and the adjacent tooth bottom facing each other with the common tooth bottom therebetween are machined, at least 2 machining steps are performed. In this case, since it is difficult to precisely match the heights of the tooth bottoms in 2 steps, the heights of the tooth bottoms vary, and a step is formed in the tooth bottom adjacent to the corner of the tooth bottom.

In addition, when one peripheral wall surface of the wall body and the adjacent tooth bottom are machined at a predetermined first machining pitch, the other peripheral wall surface of the wall body and the adjacent tooth bottom are machined at the same first machining pitch, and then only the tooth bottom is machined at a second machining pitch smaller than the first machining pitch, a step corresponding to the first machining pitch larger than the second machining pitch is generated in the tooth bottom adjacent to the corner of the tooth bottom.

In this way, since the stepped portion is easily generated in the tooth bottom corner portion of the scroll member having the inclined portion, it is particularly effective to prevent the tip seal from contacting the stepped portion by preventing the groove portion from facing the stepped portion as described above.

In addition, in a method of processing a scroll member according to an aspect of the present invention, the scroll member includes an end plate and a spiral wall body provided in the end plate, and a groove portion for receiving a tip seal is provided in a tip of the wall body, and the method includes: a first peripheral wall surface processing step of processing one peripheral wall surface of the wall body and an adjacent tooth bottom; a second peripheral wall surface machining step of machining the other peripheral wall surface of the wall body and the adjacent tooth bottom; and a groove processing step of forming the groove at a tooth tip of the end plate, wherein a stepped portion is provided at a tooth bottom corner portion of a root portion of the wall body, and the groove is formed at a position closer to a thickness direction center side of the wall body than a position facing the stepped portion.

After the first peripheral surface machining step and the second peripheral surface machining step are performed, a step is formed at a corner portion of the tooth bottom due to machining accuracy or the like. The groove is formed at a position not facing the step portion. Thereby, contact between the tip seal and the step portion can be avoided.

The step provided at the corner of the tooth bottom also includes a step inevitably formed by machining.

The scroll member includes a wall inclined portion in which the height of the wall continuously decreases from the outer circumferential side toward the inner circumferential side, and/or an end plate inclined portion in which the height of the end plate continuously increases from the outer circumferential side toward the inner circumferential side, and the wall inclined portion and the end plate inclined portion are provided within a range of 180 ° or more around the center of the lap.

In addition, a method of processing a scroll member according to an aspect of the present invention includes a method of processing a scroll member including an end plate and a spiral wall body provided in the end plate, and including an inclined portion in which a height of the wall body from a tooth bottom to a tooth top continuously changes in a scroll direction, the inclined portion being provided in a range of 180 ° or more around a center of the scroll, the method including: a first peripheral wall surface processing step of processing one peripheral wall surface of the wall body and an adjacent tooth bottom; a second peripheral wall surface machining step of machining the other peripheral wall surface of the wall body and the adjacent tooth bottom; a tooth bottom processing step of processing only a tooth bottom between the one peripheral wall surface and the other peripheral wall surface; and a groove processing step of forming a groove in a tooth crest of the end plate, wherein a step is provided at a tooth bottom corner portion of a root portion of the wall body, and the groove is formed closer to a thickness direction center side of the wall body than a position facing the step.

The inclined portion is more difficult to machine than a flat surface. Therefore, the peripheral wall surface and the tooth bottom are processed in 3 steps, with the process of processing the peripheral wall surface and the process of processing only the tooth bottom being separated. This enables the bottom of the tooth to be the inclined portion to be machined with high accuracy.

Further, since a step is likely to occur in the tooth bottom corner portion of the scroll member having the inclined portion which is difficult to machine, it is particularly effective to prevent the tip seal from contacting the step by not facing the step at the position of the groove portion as described above.

In addition, it is preferable that the machining pitch in the tooth bottom machining step is smaller than the machining pitch in each peripheral wall surface machining step, so that the inclined portion of the tooth bottom is machined with higher accuracy.

In addition, it is preferable that the tooth top of the inclined portion is also processed at the same processing pitch as that of the tooth bottom processing step.

In addition, the step portion provided at the corner portion of the tooth bottom also includes a step portion inevitably formed due to the processing.

Effects of the invention

By forming the groove portion at a position closer to the center side in the thickness direction of the wall body than the position facing the stepped portion, contact between the tip seal and the stepped portion can be prevented. This reduces fluid leakage from the gap between the tip seal and the step portion, and suppresses wear of the tip seal, thereby suppressing a reduction in performance of the scroll fluid machine.

Drawings

Fig. 1A is a longitudinal sectional view showing a fixed scroll and a orbiting scroll of a scroll compressor according to an embodiment of the present invention.

Fig. 1B is a plan view of the fixed scroll of fig. 1A viewed from the wall side.

Fig. 2 is a perspective view illustrating the swirling coil of fig. 1.

Fig. 3 is a plan view showing a flat portion of an end plate provided to the fixed scroll.

Fig. 4 is a plan view showing a flat portion of a wall body provided to the fixed scroll.

Fig. 5 is a schematic view showing the wall body shown expanded along the scroll direction.

Fig. 6 is a partially enlarged view showing an area of reference numeral Z of fig. 1B in an enlarged manner.

Fig. 7A is a side view showing the tip seal gap of the portion shown in fig. 6, and showing a state in which the tip seal gap is relatively small.

Fig. 7B is a side view showing the tip seal gap of the portion shown in fig. 6, and showing a state in which the tip seal gap is relatively large.

Fig. 8 is a vertical cross-sectional view showing a cross section of the tooth tip vicinity cut in the radial direction at the inclined portion.

Fig. 9 is a longitudinal sectional view showing a modification of fig. 8.

Fig. 10A is a longitudinal sectional view showing a combination with a scroll having no stepped portion, which is a modification.

Fig. 10B is a longitudinal sectional view showing a modification and showing a combination with a stepped scroll.

Detailed Description

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

In fig. 1, a fixed scroll (first scroll member) 3 and a orbiting scroll (second scroll member) 5 of a scroll compressor (scroll fluid machine) 1 are shown. The scroll compressor 1 is used as a compressor for compressing a gas refrigerant (fluid) to be subjected to a refrigeration cycle, such as an air conditioner.

The fixed scroll 3 and the orbiting scroll 5 are compression mechanisms made of metal such as aluminum alloy or iron, and are accommodated in a casing not shown. The fixed scroll 3 and the orbiting scroll 5 suck the fluid introduced into the housing from the outer peripheral side, and discharge the compressed fluid to the outside from the discharge port 3c at the center of the fixed scroll 3.

The fixed scroll 3 is fixed to the casing, and as shown in fig. 1A, the fixed scroll 3 includes an end plate (first end plate) 3a having a substantially disk shape and a spiral wall body (first wall body) 3b provided upright on one side surface of the end plate 3a. The swirling scroll 5 includes an end plate (second end plate) 5a having a substantially circular plate shape, and a spiral wall body (second wall body) 5b provided upright on one side surface of the end plate 5a. The spiral shape of each wall 3b, 5b is defined by, for example, an involute curve or an archimedean curve.

The fixed scroll 3 and the swirling scroll 5 are assembled as follows: the fixed scroll 3 and the orbiting scroll 5 are engaged with each other so that centers thereof are spaced by a turning radius ρ and phases of the wall bodies 3b and 5b are shifted by 180 °, and a slight clearance (tip clearance) in the height direction is provided between the tooth tips and the tooth bottoms of the wall bodies 3b and 5b of both scrolls at normal temperature. Thus, a plurality of pairs of compression chambers surrounded by the end plates 3a, 5a and the wall bodies 3b, 5b are formed between the two scrolls 3, 5 symmetrically with respect to the scroll center. The orbiting scroll 5 performs an orbiting and orbiting motion around the fixed scroll 3 by a rotation preventing mechanism such as a spider not shown.

As shown in fig. 1A, inclined portions are provided in which the facing surface-to-surface distance L between the opposite end plates 3a, 5a decreases continuously from the outer circumferential side to the inner circumferential side of the spiral wall bodies 3b, 5b.

As shown in fig. 2, wall inclined portion 5b1 whose height continuously decreases from the outer circumferential side toward the inner circumferential side is provided on wall 5b of orbiting scroll 5. An end plate inclined portion 3a1 (see fig. 1A) inclined in accordance with the inclination of the wall inclined portion 5b1 is provided on the tooth bottom surface of the fixed scroll 3 facing the tooth tip of the wall inclined portion 5b1. These wall inclined parts 5b1 and end plate inclined parts 3a1 form continuous inclined parts. Similarly, wall inclined portion 3b1 whose height is continuously inclined from the outer circumferential side toward the inner circumferential side is also provided on wall 3b of fixed scroll 3, and end plate inclined portion 5a1 facing the tooth tip of wall inclined portion 3b1 is provided on end plate 5a of orbiting scroll 5.

The term "continuously" in the inclined portion in the present embodiment is not limited to a smoothly continuous inclination, and includes a case where a small step portion inevitably generated during processing is connected in a stepwise manner, and the entire inclined portion is continuously inclined. However, the large step portion such as a so-called stepped scroll is not included.

The inclined wall portions 3b1 and 5b1 and/or the inclined end plate portions 3a1 and 5a1 are coated with a coating. Examples of the coating layer include manganese phosphate treatment and nickel-phosphorus plating.

As shown in fig. 2, wall flat portions 5b2, 5b3 of constant height are provided on the innermost circumference side and the outermost circumference side of wall 5b of orbiting scroll 5. These wall flat portions 5b2 and 5b3 are provided in the range of the 180 ° region around the center O2 (see fig. 1A) of the swirl coil 5. Wall inclined connection portions 5b4 and 5b5 serving as bent portions are provided at positions where the wall flat portions 5b2 and 5b3 are connected to the wall inclined portion 5b1, respectively.

Similarly, end plate flat portions 5a2, 5a3 having a constant height are provided on the tooth bottom of the end plate 5a of the orbiting scroll 5. These end plate flat portions 5a2, 5a3 are also provided in the range of the 180 ° region around the center of the swirl coil 5. End plate inclined connecting portions 5a4 and 5a5 serving as bent portions are provided at positions where the end plate flat portions 5a2 and 5a3 are connected to the end plate inclined portion 5a1, respectively.

As shown by hatching in fig. 3 and 4, similarly to orbiting scroll 5, fixed scroll 3 is also provided with end plate flat portions 3a2, 3a3, wall flat portions 3b2, 3b3, end plate inclined connecting portions 3a4, 3a5, and wall inclined connecting portions 3b4, 3b5.

In fig. 5, the walls 3b, 5b are shown expanded in the scroll direction. As shown in the drawing, the innermost wall flat portions 3b2 and 5b2 are provided within a range of distance D2, and the outermost wall flat portions 3b3 and 5b3 are provided within a range of distance D3. The distance D2 and the distance D3 are lengths corresponding to regions that make an angle of 180 ° (180 ° to 360 °, preferably 210 ° to 210 °) around the centers O1 and O2 of the respective scrolls 3 and 5, respectively. Wall inclined portions 3b1 and 5b1 are provided between wall flat portions 3b2 and 5b2 on the innermost circumferential side and wall flat portions 3b3 and 5b3 on the outermost circumferential side within the range of distance D1. When the height difference between the innermost wall flat portions 3b2 and 5b2 and the outermost wall flat portions 3b3 and 5b3 is h, the inclinations of the wall inclined portions 3b1 and 5b1 are set to hIs represented by the following formula.

Thus, the inclination of the inclined partThe circumferential direction in which spiral wall bodies 3b and 5b extend is constant. Distance D1 is longer than distance D2, and distance D1 is longer than distance D3.

For example, in the present embodiment, the sizes of the scrolls 3 and 5 are as follows.

(1) Radius of gyration ρ [ mm ]: 2 to 15 inclusive, preferably 3 to 10 inclusive

(2) Number of windings of wall bodies 3b, 5 b: 1.5 to 4.5 inclusive, preferably 2.0 to 3.5 inclusive

(3) Height difference h [ mm ]: 2 to 20 inclusive, preferably 5 to 15 inclusive

(4) h/Lout (height of outermost wall): 0.05 to 0.35 inclusive, preferably 0.1 to 0.25 inclusive

(5) Angular range of the inclined portion (angular range corresponding to the distance D1) [ ° ]: 180 to 1080 inclusive, preferably 360 to 720 inclusive

(6) Angle of the inclined part

0.2 to 4 inclusive, preferably 0.5 to 2.5 inclusive

In fig. 6, an enlarged view of the region indicated by reference numeral Z of fig. 1B is shown. As shown in fig. 6, a tip seal 7 is provided on the tooth tip of the wall body 3b of the fixed scroll 3. The tip seal 7 is made of resin, and contacts the end plate 5a of the orbiting scroll 5 facing the tip seal to seal the fluid. The tip seal 7 is housed in a tip seal groove 3d formed in the tooth tip of the wall body 3b over the entire circumferential direction. The compressed fluid enters the tip seal groove 3d, presses the tip seal 7 from the back surface and pushes it toward the tooth bottom side, thereby bringing the tip seal 7 into contact with the opposing tooth bottom. A tip seal is similarly provided to the tooth tips of the wall 5b of the swirling disc 5.

As shown in fig. 7, the height Hc of the tip seal 7 in the height direction of the wall body 3b is constant in the circumferential direction.

When the two scrolls 3 and 5 perform the orbital revolution motion relatively, the positions of the tooth tip and the tooth bottom are shifted relatively by the revolution diameter (revolution radius p × 2). Due to the positional deviation of the tooth tip and the tooth bottom, the tip clearance between the tooth tip and the tooth bottom varies in the inclined portion. The amount of change in head space Δ h [ mm ] is, for example, 0.05 to 1.0, preferably 0.1 to 0.6. For example, fig. 7A shows a case where the tip clearance T is small, and fig. 7B shows a case where the tip clearance T is large. Even if the tip clearance T changes due to the swirling motion, the tip seal 7 is pressed from the back surface toward the tooth bottom side of the end plate 5a by the compressed fluid, and therefore the tip seal 7 can follow the sealing.

Fig. 8 shows a cross section of the vicinity of the tooth tip cut in the radial direction at a predetermined position of the wall body inclined portion 3b1 of the fixed scroll 3. The cross section of the wall inclined portion 5b1 of the orbiting scroll 5 in the vicinity of the tooth tip cut in the radial direction is also the same shape. Therefore, only the relationship between the tooth tip of the wall inclined portion 3b1 of the fixed scroll 3 and the tooth bottom of the end plate inclined portion 5a1 of the orbiting scroll 5 facing the tooth tip will be described below.

As shown in the figure, the tooth tips of the wall 3b and the tooth bottoms of the end plates 5a are located at positions facing each other. A tip seal 7 accommodated in the tip seal groove 3d is disposed at the tooth tip of the wall body 3b. The tip seal groove 3d is formed to have a groove width Tw slightly larger than the width of the tip seal 7. Note that reference numeral Tr denotes the width of the wall body 3b. Note that reference sign Ta is a bank width corresponding to the dimension of the tooth tip from the peripheral wall of the wall body 3b to the tip seal groove 3d. That is, the region of the bank width Ta is a region where the tip seal groove 3d is not formed at the tooth tip.

The tip seal 7 is pressed toward the tooth bottom side (lower side in the figure) by the pressure of the fluid entering the back surface of the tip seal 7. The wall 3b is located near one wall 5bR (right side in the figure), and is sealed at this position to close the compression chamber. The wall 3b is separated from the other wall 5bL (left side in the figure), and a compression chamber is formed between the wall 3b and the other wall 5 bL.

A step 9a protruding from the central tooth bottom is formed in the tooth bottom corner 9 at the root of the wall body 5b. The step 9a has a step width Sw and is located opposite the tooth top corner 8 of the wall 3b.

The tip seal groove 3d is formed so as to be offset toward the center side in the thickness direction of the wall body 3b from the position facing the step portion 9a. That is, the bank width Ta of the tooth top of the wall body 3b is larger than the step width Sw of the step 9a of the tooth bottom corner 9. Thereby, the tip seal 7 is disposed at a position not contacting the step portion 9a.

The step portion 9a located at the tooth bottom corner portion 9 is inevitably formed by performing the machining of the end plate inclined portion 5a1. This is because the processing of forming the inclined surface on the tooth bottom of the end plate 5a is more difficult than the processing of a flat surface. The end plate inclined portion 5a1 is processed by a processing step including the following 3 steps.

First, as the machining in step 1, the peripheral wall surface of one wall body 5bR and the adjacent tooth bottom are machined using an end mill (first peripheral wall surface machining step). The machining pitch in this step is provided as a first machining pitch p1 and as a program of instructions for an nc (numerical control) machine. The diameter of the end mill at this time is De, and is slightly smaller than the tooth bottom width Tg.

Next, as the machining in step 2, the peripheral wall surface of the other wall body 5bL and the adjacent tooth bottom are machined using an end mill (second peripheral wall surface machining step). The machining pitch in this step is the first machining pitch p1 that is the same as the machining pitch in step 1. The diameter of the end mill used was the same diameter De as in step 1.

Finally, as the machining in step 3, only the tooth bottom at the center between the peripheral wall surface of one wall body 5bR and the peripheral wall surface of the other wall body 5bL is machined (tooth bottom machining step). The machining pitch in this step is the second machining pitch p2 smaller than the first machining pitch p1 in the 1 st step and the 2 nd step. This makes the inclination of the tooth bottom surface as smooth as possible. The diameter of the end mill is smaller than the tooth bottom width Tg, and for example, the same diameter De as in the 1 st step and the 2 nd step is used.

As described above, the end plate inclined portion 5a1 and the peripheral wall surface of the wall body 5b adjacent thereto are processed through the processing steps set to 3 steps. At this time, since the second machining pitch p2 used in the 3 rd step of machining the bottom of the tooth is smaller than the first machining pitch p1 in the 1 st step and the 2 nd step, the stepped portions 9a remain in the corner portions 9 of the bottom of the tooth on both sides where the machining in the 3 rd step is not performed.

If it is assumed that the processing in the 3 rd step is performed along the center of the tooth bottom width, the step width Sw of the step 9a is (Tg-De)/2.

The stepped portion 9a may be generated by a difference (machining error) between the cutting edge height of the end mill during the machining in the 1 st step and the 2 nd step (in the vertical direction in the drawing) and the cutting edge height of the end mill during the machining in the 3 rd step.

The tooth tips of the wall body 3b, i.e., the wall body inclined portion 3b1, are machined using the second machining pitch p2, which is the same as the machining in the above-described step 3. Then, the tip seal groove 3d is formed.

The scroll compressor 1 described above operates as follows.

The orbiting scroll 5 performs an orbital orbiting motion around the fixed scroll 3 by a drive source such as an electric motor not shown. Thereby, the fluid is sucked from the outer peripheral side of each scroll 3, 5, and taken into the compression chamber surrounded by each wall 3b, 5b and each end plate 3a, 5a. The fluid in the compression chamber is sequentially compressed as it moves from the outer circumferential side to the inner circumferential side, and finally the compressed fluid is discharged from the discharge port 3c formed in the fixed scroll 3. When the fluid is compressed, the fluid is also compressed in the height direction of wall bodies 3b, 5b at the inclined portions formed by end plate inclined portions 3a1, 5a1 and wall body inclined portions 3b1, 5b1, and the fluid is compressed three-dimensionally.

According to the present embodiment, the following operational effects are exhibited.

In the machining of the tooth bottom, a step 9a is formed at a tooth bottom corner 9 of the root of the wall body 5b. When the tip seal 7 makes contact across the step portion 9a, there is a possibility that a gap is generated between the tip seal 7 and the tooth bottom to cause leakage of fluid, and there is a possibility that the tip seal 7 is worn.

Therefore, in the present embodiment, the tip seal groove 3d is formed at a position closer to the center side in the thickness direction of the wall body 3b than the position facing the step portion 9a, so that the tip seal 7 does not contact the step portion 9a. That is, the bank width Ta is made larger than the step portion width Sw (Ta > Sw). This can reduce the wear of the tip seal 7 while reducing the leakage, and can suppress the performance degradation of the scroll compressor 1.

Since the step 9a is likely to occur in the tooth bottom corner 9 due to difficulty in machining in the scrolls 3 and 5 having the end plate inclined portions 3a1 and 5a1 as in the present embodiment, it is particularly effective to prevent the tip seal groove 3d from being positioned so as not to face the step 9a and so as not to allow the tip seal 7 to contact the step 9a.

The peripheral wall surfaces and the tooth bottoms are processed in 3 steps, with the process of processing the peripheral wall surfaces of the wall bodies 5bR and 5bL and the process of processing only the tooth bottoms being separated. This enables the bottom of the tooth to be the inclined portion to be machined with high accuracy.

In the present embodiment, the structure for avoiding contact with the step 9a that occurs when the tooth bottom is machined by 3-step machining is described, but as shown in fig. 9, the present invention can also be applied to the step 9 a' that occurs when the tooth bottom is machined by 2-step machining.

The tooth bottom of the end plate 5a shown in fig. 9 is processed by 2 steps as described below.

First, as the machining in step 1, the peripheral wall surface of one wall body 5bR and the adjacent tooth bottom are machined using an end mill.

Next, as the machining in step 2, the peripheral wall surface of the other wall body 5bL and the adjacent tooth bottom are machined using an end mill. The tooth bottom formed at this time is set to a final shape. In the 2 nd step, the second processing pitch p2, which is smaller than the first processing pitch p1 of the 1 st step, may be used as the processing pitch, and the first processing pitch p1 may also be used as the processing pitch.

When the machining is performed in 2 steps, as described above, the step 9 a' is inevitably generated due to the difference in the machining pitch or the difference in the cutting edge height of the end mill (machining error) in the machining in the 1 st step and the 2 nd step. In this case, the width Sw' of the step is (Tg-De).

A tip seal groove 3d is formed at a position closer to the center side in the thickness direction of the wall body 3b than a position facing the step portion 9a 'so as to avoid contact with the step portion 9 a'. Accordingly, the step 9 a' formed by the 2-step processing can be prevented from coming into contact with the tip seal 7, and the performance degradation of the scroll compressor 1 can be suppressed.

In the present embodiment, the end plate inclined portions 3a1, 5a1 and the wall inclined portions 3b1, 5b1 are provided in both scrolls 3, 5, but they may be provided in either of them.

Specifically, as shown in fig. 10A, when the wall inclined portion 5b1 is provided on one wall body (for example, the swirling disc 5) and the end plate inclined portion 3a1 is provided on the other end plate 3a, the other wall body and the one end plate 5a may be flat.

As shown in fig. 10B, the scroll may be combined with a conventional stepped shape, that is, a shape in which an end plate inclined portion 3a1 is provided in an end plate 3a of the fixed scroll 3 and a stepped portion is provided in an end plate 5a of the orbiting scroll 5.

In the present embodiment, wall flat portions 3b2, 3b3, 5b2, 5b3 and end plate flat portions 3a2, 3a3, 5a2, 5a3 are provided, but the inner circumferential side and/or outer circumferential side flat portions may be omitted and the inclined portion may be provided so as to extend to the entire wall portions 3b, 5b.

In the present embodiment, the scroll compressor 1 having the inclined portion is described, but in a normal scroll compressor or a stepped scroll compressor having no stepped portion, the stepped portions 9a and 9 a' may be generated due to a machining error of the tooth bottom corner portion. Therefore, the present invention can be applied to a general scroll compressor or a stepped scroll compressor which does not have a stepped portion.

In the present embodiment, a scroll compressor is described, but the present invention can also be applied to a scroll expander used as an expander.

Description of reference numerals:

a scroll compressor (scroll fluid machine);

a fixed scroll (first scroll member);

an end plate (first end plate);

3a1.. end plate slope;

3a2.. the end plate flat portion (inner peripheral side);

3a3.. end plate flat portion (outer peripheral side);

3a4.. end plate inclined connection portion (inner peripheral side);

3a5.. end plate inclined connection part (outer circumferential side);

a wall (first wall);

a wall inclined portion;

3b2... wall flat portion (inner peripheral side);

3b3.. wall flat portion (outer peripheral side);

3b4.. wall body inclined connection part (inner peripheral side);

3b5.. wall body inclined connection part (outer circumference side);

a spout;

a top end seal groove;

a swirling disc (second scroll member);

an end plate (second end plate);

5a1.. an end plate slope;

5a2.. the end plate flat portion (inner peripheral side);

5a3.. end plate flat portion (outer peripheral side);

5a4.. end plate inclined connection portion (inner peripheral side);

5a5.. end plate inclined connection part (outer circumferential side);

a wall (second wall);

a wall inclined portion;

5b2... wall flat portion (inner peripheral side);

5b3.. wall flat (outer peripheral side);

5b4.. wall body inclined connection (inner peripheral side);

5b5.. wall body inclined connection part (outer circumference side);

a tip seal;

a tooth apex corner;

a tooth bottom corner;

a step;

de.. end mill diameter;

l. distance between opposite surfaces;

sw.. step width;

a top clearance;

ta.. bank width;

tr.. wall width;

tw.. slot width;

tg.. tooth bottom width;

...