JP2007270762A - Manufacturing method for seal member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a seal member, capable of securely preventing the one-sided abutment state of the seal member and easily fitting to a seal groove. <P>SOLUTION: A strip-shaped seal body 22 is spirally bent and inserted into a groove 24A of a die 23 for shape change. Then, the seal body 22 is heated by using a heater 26 and pressed by using a pressing machine 27. The seal body 22 is held in this heated and pressed state. Due to this, plastic deformation is generated in the seal body 22. As a result, a chip seal 20 of which spiral shape is maintained in the natural state can be formed, and the cross section of the overall length of the chip seal 20 can be formed to have an approximately tetragonal shape. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a seal member to be attached to a spiral wrap formed on a scroll.

  Generally, a scroll type fluid machine includes two scrolls facing each other, and each scroll has a configuration in which a spiral wrap portion is erected on the bottom surface of its end plate. Then, by arranging the two scrolls to face each other, the two wrap portions overlap each other to define a plurality of compression chambers. In this state, one of the scrolls is swung with respect to the other scroll to continuously reduce the compression chamber to compress air or the like.

  Moreover, the structure which provided the sealing member for ensuring the airtightness of each compression chamber in the tooth tip surface of the lap | wrap part of a scroll as a prior art is known (for example, refer patent document 1). At this time, a spiral seal groove extending along the length direction of the wrap portion is opened on the tooth tip surface of the wrap portion. The seal member is mounted in the seal groove.

JP-A-8-93668

  Here, the seal member is formed of a resin composite material including, for example, polytetrafluoroethylene (PTFE) in order to satisfy the conditions such as heat resistance, wear resistance, and slidability. The cross-sectional shape (transverse cross section) of the seal member is formed in a rectangular shape that is slightly smaller than the groove shape of the seal groove, for example.

  And one side of the four sides constituting the cross-sectional shape of the seal member becomes a seal surface that comes into surface contact with the tooth bottom surface of the other end plate during operation of the compressor, and this seal surface is in sliding contact with the other tooth bottom surface. It has a configuration that exhibits sealing properties.

  In general, a resin composite material containing PTFE is difficult to be injection-molded as a spiral seal member. For this reason, in the prior art, the seal member before being installed in the seal groove is preliminarily resin-molded, for example, as a flexible elongated string-like seal body, and this seal body is spirally formed when the compressor is assembled. It is configured to be fitted into the seal groove while being curved.

  By the way, in the prior art described in the above-mentioned Patent Document 1, for example, a string-like seal body including PTFE is bent so that it is fitted into the seal groove as a spiral seal member. In this case, the curvature of the seal groove is small on the outer diameter side and gradually increases toward the inner diameter side. Therefore, the seal groove can be fitted into the outer diameter side of the seal groove only by gently bending the seal body.

  However, it is necessary to fit into the inner diameter side of the seal groove in an extremely curved state so as to bend the seal body. In such a curved portion, for example, the cross-sectional shape of the seal body is crushed and is distorted into a parallelogram or a trapezoidal shape, so that the seal surface of the seal member is inclined with respect to the other tooth bottom surface. Sometimes.

  In this case, when the compression operation is performed, there is a case where only a part on the tip end side of the seal member is in sliding contact with the other tooth bottom surface (one-contact state). In this state, the seal member cannot function sufficiently and the compression performance is lowered, or the durability of the seal member is lowered.

  Therefore, in the prior art described in Patent Document 1, one end side of the seal member located on the inner diameter side of the seal groove is divided into two parts, the bending rigidity of the portion is reduced, and the seal member is in a single-contact state. Is preventing. However, even in this case, when the seal member is bent into a spiral shape and fitted into the seal groove, the cross-sectional shape remains the same, and the one-contact state of the seal member cannot be sufficiently prevented. is there.

  Further, since the string-like seal body is inserted into the seal groove while being curved, there is a problem that the workability of attaching the seal member is low and it takes time and effort.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a method for manufacturing a seal member that can surely prevent the contact state of the seal member and can be easily mounted in a seal groove. There is to do.

  In order to solve the above-described problems, the invention of claim 1 changes the shape of a string-like seal body made of a resin composite material in a method of manufacturing a seal member attached to a spiral wrap formed on a scroll. It is characterized in that a spiral seal member is formed by performing a shape changing process in which the seal body is inserted into a spiral groove of a mold and heated in a pressurized state.

  According to a second aspect of the present invention, there is provided a method for manufacturing a seal member attached to a spiral wrap formed on a scroll, and a cutter is used to cut at least one side surface of a string-like seal body made of a resin composite material. The lip portion forming step is performed to form a plurality of lip portions spaced apart in the length direction of the seal body, and then the seal body formed with the lip portion is placed in the spiral groove of the shape changing mold A shape changing step of inserting and heating the seal body in a pressurized state is performed, and a spiral seal member is formed.

  According to the invention of claim 1, since the string-like seal body is inserted into the spiral groove of the shape changing mold and the seal body is heated in a pressurized state, the string-like seal body is plastically deformed. A spiral seal member can be formed. Further, when the seal body is plastically deformed, the cross-sectional shape thereof can be formed, for example, in a square shape corresponding to the seal groove of the wrap portion over the entire length of the seal member.

  For this reason, even when the seal member is mounted in the seal groove of the wrap portion, the cross-sectional shape of the seal member is not distorted and deformed, and the seal member is connected to the opposite end plate over the entire length from the inner diameter side to the outer diameter side. Surface contact can be made stably. As a result, high sealing performance can be exhibited during the compression operation, and air leakage due to poor sealing or the like can be suppressed, so that the compression performance and durability can be improved.

  Further, since the string-like seal body is plastically deformed by the shape changing step to form the spiral seal member, the seal member is held in a spiral shape even in a free state. For this reason, since the seal member can be inserted into the seal groove as it is and mounted, the mounting workability of the seal member can be improved and the productivity can be increased.

  Further, according to the invention of claim 2, since the lip portion forming step for forming a plurality of lip portions separated in the length direction of the seal body is performed before the shape changing step, for example, the seal body is preliminarily provided. A plurality of lip portions that are easily separated in the length direction of the seal body can be formed by rotating the annular seal body and advancing the cutter with respect to the seal body by forming the ring-shaped string-like body. Can be formed. Thereafter, by cutting the annular seal body at one place, a seal body as a linear string-like body can be formed. Therefore, by applying a shape changing process to the string-like seal body, a spiral shape is obtained. The seal member can be manufactured. As a result, the lip portion can be easily processed as compared with the case where the lip portion is formed after the spiral seal member is formed.

  Hereinafter, an air compressor is taken as an example of a scroll type fluid machine according to an embodiment of the present invention and will be described in detail with reference to the accompanying drawings.

  First, FIG. 1 to FIG. 8 show a first embodiment. In the figure, reference numeral 1 denotes a casing that forms the outer shell of the compressor. The casing 1 is formed in a bottomed cylindrical shape that is open on one side in the axial direction, and has an output shaft 2A on the other side in the axial direction. A motor 2 is attached. Moreover, the scroll type air compressor of this Embodiment is a small compressor mounted as a pneumatic actuator in vehicles, such as a motor vehicle.

  Reference numeral 3 denotes a fixed scroll provided on one side of the casing 1 in the axial direction. The fixed scroll 3 is formed using, for example, a metal material such as aluminum or an alloy thereof, and includes a disc-shaped end plate 4 and the end plate 4 is substantially constituted by a spiral wrap portion 5 erected on the tooth bottom surface 4 </ b> A in the axial direction and a cylindrical support portion 6 provided on the outer peripheral side of the end plate 4 and surrounding the wrap portion 5. ing.

  Here, as shown in FIGS. 2 and 3, for example, when the outermost diameter end is the winding start end and the outermost diameter end is the winding end end, the wrap portion 5 is, for example, from the inner diameter side toward the outer diameter side. It is wound in a spiral shape three times before and after. As shown in FIGS. 4 and 5, the tooth tip surface 5 </ b> A of the wrap portion 5 is axially displaced by a certain dimension from the tooth bottom surface 9 </ b> A of the opposite end plate 9, similar to the wrap portion 10 of the orbiting scroll 8 described later. The tooth tip surface 5A is provided with a seal groove 7 which will be described later.

  7 is a seal groove provided on the tooth tip surface 5 </ b> A of the wrap portion 5, and the seal groove 7 is provided with a chip seal 20 described later. Here, as shown in FIGS. 2 and 3, the seal groove 7 is formed as a spiral concave groove and extends in the length direction of the wrap portion 5, as in a seal groove 12 described later.

  Further, as shown in FIGS. 4 and 5, the cross-sectional shape (transverse cross section) of the seal groove 7 is formed, for example, in a substantially U shape or a square shape. The seal groove 7 has a bottom surface 7A, an inner wall surface 7B positioned on the radially inner side of the bottom surface 7A, and an outer wall surface 7C positioned on the radially outer side of the bottom surface 7A.

  8 is a turning scroll provided in the casing 1 so as to be able to turn in the casing 1 so as to face the fixed scroll 3, and the turning scroll 8 is made of a metal material such as aluminum or an alloy thereof, for example, in the same manner as the fixed scroll 3. Is formed.

  Then, as shown in FIG. 1, the orbiting scroll 8 stands in the axial direction from the tooth bottom surface 9 </ b> A of the end plate 9 toward the end plate 4 of the fixed scroll 3. The spiral wrap portion 10 is provided, and a boss portion 11 that protrudes from the center of the rear surface of the end plate 9 and is connected to a drive shaft 13 described later.

  Here, as shown in FIGS. 2 and 3, the wrap portion 10 is wound, for example, in a spiral shape before and after the third turn from the inner diameter side toward the outer diameter side. As shown in FIGS. 4 and 5, a seal groove 12 having a bottom surface 12 </ b> A, an inner wall surface 12 </ b> B, and an outer wall surface 12 </ b> C is provided on the tooth tip surface 10 </ b> A side of the wrap portion 10. A seal 20 is attached.

  A drive shaft 13 is rotatably provided in the casing 1 via a bearing or the like. The drive shaft 13 is attached to the output shaft 2A of the motor 2 at the base end side as shown in FIG. Driven. Further, the boss portion 11 of the orbiting scroll 8 is connected to the front end side of the drive shaft 13 via an eccentric bush 14 and an orbiting bearing 15 so as to be orbitable. The eccentric bush 14 connects the boss portion 11 and the drive shaft 13 to each other in a state of being eccentric in the radial direction.

  As a result, when the drive shaft 13 rotates, the orbiting scroll 8 performs an orbiting motion with a constant orbiting radius about the axis. In this case, for example, three anti-rotation mechanisms 16 (only one is shown) are provided between the casing 1 and the back side of the orbiting scroll 8 to prevent the orbiting scroll 8 from rotating during the orbiting motion. .

  The orbiting scroll 8 is disposed so as to overlap with the fixed scroll 3 by, for example, 180 degrees, and a plurality of compression chambers 17 are provided between the wrap portions 5 and 10 from the outer diameter side to the inner diameter side (center). Is defined. During the operation of the compressor, air is sucked into the compression chambers 17 on the outer diameter side from the suction port 18 provided in the fixed scroll 3, and the air is sequentially compressed in each compression chamber 17. The compressed air accommodated in the compression chamber 17 on the side is discharged to the outside from the discharge port 19 provided in the fixed scroll 3.

  Next, the tip seal 20 as a seal member mounted in the seal grooves 7 and 12 of the fixed scroll 3 and the orbiting scroll 8 will be described.

  First, the tip seal 20 mounted in the seal groove 12 of the orbiting scroll 8 will be described as an example. This tip seal 20 is formed by the wrap portion 10 of the orbiting scroll 8 and the end plate 4 of the fixed scroll 3 as the counterpart. It seals the gap.

  Here, the chip seal 20 has a substantially square cross-sectional shape as shown in FIGS. 4 and 5, and a bottom surface 20A disposed on the bottom side of the seal groove 12, and the seal groove 12 facing the bottom surface 20A. A seal surface 20B disposed on the opening side, an inner peripheral surface 20C connecting the bottom surface 20A and the seal surface 20B on the inner peripheral side, and an outer peripheral surface 20D connecting the bottom surface 20A and the seal surface 20B on the outer peripheral side. I have.

  Further, the tip seal 20 is obtained by changing the shape of a flexible string-like seal body 22 into a spiral shape and mounting it in the seal groove 12, and as shown in FIG. It has an inner diameter portion 20E mounted on the inner diameter side having a large curvature, and an outer diameter portion 20F mounted on the outer diameter side having a small curvature.

  The chip seal 20 is formed using a resin composite material containing polytetrafluoroethylene (PTFE) or the like as a resin material having excellent heat resistance, wear resistance, and slidability, for example. Specifically, the chip seal 20 is made of, for example, a powdered hard material having an old Mohs hardness of 6 to 8 and an average particle diameter of 100 μm or less, a polytetrafluoroethylene resin and / or tetrafluoroethylene perfluoro It is formed using a resin composite material containing an alkoxyethylene resin (PFA). In this case, the hard material is one or more selected from diatomaceous earth, tourmaline, silicate mineral, and metal oxide, and the molecular weight of tetrafluoroethylene / perfluoroalkoxyethylene resin is 5 million or more. Is preferred. The tip seal 20 extends in a spiral shape along the length direction of the seal groove 12.

  4 and 5, when the compressed air flows into the inner circumferential side of the seal groove 12 during the operation of the compressor, the tip seal 20 and the opposite end plate 4 are pressed by the pressing forces A and B of the compressed air. It will be in the state pressed against the outer wall surface 12C of the seal groove 12, and this will exhibit a sealing performance.

  On the other hand, the tip seal 20 mounted in the seal groove 7 of the fixed scroll 3 seals between the tooth bottom surface 9A of the orbiting scroll 8 (end plate 9) as the counterpart. The configuration is the same as that of the 8-side chip seal 20.

  The scroll type air compressor according to the present embodiment has the above-described configuration. Next, a method for manufacturing the tip seal 20 will be described with reference to FIGS.

  First, in the sealing body forming step, as shown in FIG. 6, a circular string-like sealing body 21 is resin-molded using a resin composite material including, for example, PTFE. At this time, the sealing body 21 may be formed by, for example, forming a cylindrical body of a resin composite material and then cutting the cylindrical body into a desired thickness. Thereafter, the annular seal body 21 is cut at one place to form a linear string-like seal body 22.

  Next, in the shape changing step, as shown in FIGS. 7 and 8, the string-like sealing body 22 is spirally curved and inserted into the spiral groove 24 </ b> A of the shape changing die 23. At this time, the shape changing die 23 is constituted by, for example, a press die 24 formed in a substantially rectangular parallelepiped shape and having a groove 24A, and a male die 25 that is inserted into the groove 24A of the press die 24 and presses the seal body 22. ing.

  Here, the groove 24 </ b> A is formed in a spiral shape that is located in the center portion of the press die 24 and penetrates in the height direction of the press die 24. At this time, the groove 24 </ b> A is formed in substantially the same shape as the seal groove 7 of the fixed scroll 3 or the seal groove 12 of the orbiting scroll 8. Further, the press die 24 is provided with, for example, four heaters 26 for heating the sealing body 22 located around the groove 24A.

  On the other hand, the male die 25 is formed by erecting a spiral projection 25B on a flat plate 25A, such as the fixed scroll 3 or the orbiting scroll 8. At this time, the protrusion 25 </ b> B is formed in a spiral shape along the groove 24 </ b> A of the press die 24. However, the thickness dimension of the protrusion 25B is set to a value slightly smaller than the gap dimension of the groove 24A so that it can be inserted into the groove 24A.

  The shape changing die 23 is attached to the press machine 27 with the sealing body 22 and the projection 25B of the male die 25 inserted in the groove 24A of the press die 24. At this time, the press machine 27 includes a flat pedestal portion 27A and a pusher 27B provided to face the pedestal portion 27A. And the press machine 27 presses the male type | mold 25 toward the base part 27A with the pusher 27B in the state which mounted the press type | mold 24 on the base part 27A. Thereby, the seal body 22 is sandwiched between the tip of the protrusion 25 </ b> B of the male mold 25 and the base portion 27 </ b> A of the press machine 27.

  Then, a pressure of, for example, 30 to 50 MPa is applied to the seal body 22 using the press machine 27, and is heated to, for example, about 300 to 350 ° C. using the heater 26. In this pressurized and heated state, the seal body 22 is held for, for example, 1 to 2 hours. As a result, the seal body 22 is plastically deformed, and the tip seal 20 is formed that maintains the spiral shape even in a free state. At this time, both the inner diameter portion 20E and the outer diameter portion 20F of the chip seal 20 have a substantially square cross-sectional shape.

  When the above shape changing step is completed, the press die 24 and the male die 25 of the shape changing die 23 are separated, and the chip seal 20 is taken out. As a result, the tip seal 20 in which the spiral shape of the outer shape and the square shape of the cross section are held in a free state is completed.

  Next, the operation of the air compressor will be described. When the drive shaft 13 is first rotationally driven by the motor 2, the rotation of the drive shaft 13 is transmitted to the orbiting scroll 8 via the eccentric bush 14, the orbiting bearing 15, and the like. Thereby, the orbiting scroll 8 performs the orbiting motion around the drive shaft 13 in a state where the rotation is restricted by the rotation preventing mechanism 16.

  At this time, the compression chamber 17 defined between the wrap portion 5 of the fixed scroll 3 and the wrap portion 10 of the orbiting scroll 8 is continuously reduced from the outer diameter side toward the inner diameter side. Thus, the compressor sequentially compresses the outside air sucked from the suction port 18 in each compression chamber 17 and discharges the compressed air from the discharge port 19 toward an external tank (not shown) or the like.

  Further, during the compression operation, the compression chamber 17 positioned on the inner peripheral side of the seal grooves 7 and 12 has a higher pressure than the compression chamber 17 positioned on the outer peripheral side, so , Compressed air flows from the compression chamber 17 as shown in FIGS.

  Thereby, the tip seal 20 in the seal groove 7 is pressed against the outer wall surface 7C of the seal groove 7 by the pressing force B while being in sliding contact with the tooth bottom surface 9A of the opposite end plate 9 by the pressing force A of the compressed air. Become. Similarly, the chip seal 20 in the seal groove 12 is also pressed against the outer wall surface 12C of the seal groove 12 while being in sliding contact with the tooth bottom surface 4A of the counterpart end plate 4.

  Here, when the shape changing step is not performed as in the prior art, the tip seal 28 is fitted into the seal grooves 7 and 12 in an extremely curved state so as to be bent as in the comparative example shown in FIG. Therefore, for example, in the inner diameter portion 28E of the tip seal 28, the inner peripheral surface 28C swells more than the outer peripheral surface 28D, and the cross-sectional shape of the tip seal 28 is distorted into a parallelogram or trapezoid. For this reason, in the comparative example, the bottom surface 28A and the seal surface 28B of the chip seal 28 are inclined obliquely, and the sealing performance tends to be lowered.

  In contrast, in the present embodiment, the tip seal 20 is held in a spiral shape in a free state by performing a shape changing step, and corresponds to the seal grooves 7 and 12 over substantially the entire length. It is held in a substantially rectangular shape. For this reason, as shown in FIGS. 4 and 5, the tip seal 20 is in surface contact with the opposite end plates 4 and 9 at individual portions from the inner diameter portion 20 </ b> E to the outer diameter portion 20 </ b> F. As a result, a high sealing performance can be exhibited over the entire length of the tip seal 20, and the airtightness of each compression chamber 17 can be stably secured.

  Thus, according to the present embodiment, the string-like seal body 22 is inserted into the spiral groove 24A of the shape changing mold 23 and the seal body 22 is heated in a pressurized state. The spiral tip seal 20 can be formed by plastically deforming 22. Further, when the seal body 22 is plastically deformed, the cross-sectional shape thereof can be formed, for example, in a square shape corresponding to the seal grooves 7 and 12 of the wrap portions 5 and 10 over the entire length of the chip seal 20.

  For this reason, even when the chip seal 20 is mounted in the seal grooves 7 and 12, the cross-sectional shape of the chip seal 20 is not distorted and deformed, and the chip seal 20 extends from the inner diameter portion 20E to the entire outer diameter portion 20F. Thus, the surface can be stably brought into contact with the opposite end plates 4 and 9. As a result, high sealing performance can be exhibited during the compression operation, and air leakage due to poor sealing or the like can be suppressed, so that the compression performance and durability can be improved.

  Moreover, since the string-like seal body 22 is plastically deformed by the shape changing process to form the spiral tip seal 20, the tip seal 20 is held in a spiral shape even in a free state. For this reason, since the chip seal 20 can be inserted and mounted in the seal grooves 7 and 12 as it is, the mounting workability of the chip seal 20 can be improved and the productivity can be increased.

  Next, FIG. 10 to FIG. 16 show a second embodiment, and the feature of the second embodiment is that a plurality of lip portions separated in the length direction of the seal body are formed before the shape changing step. The lip portion forming step is performed. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  First, a chip seal 31 as a seal member mounted in the seal grooves 7 and 12 of the fixed scroll 3 and the orbiting scroll 8 will be described.

  First, the tip seal 31 mounted in the seal groove 12 of the orbiting scroll 8 will be described as an example. As shown in FIGS. 10 to 12, the tip seal 31 is connected to the wrap portion 10 of the orbiting scroll 8 and the counterpart. The space between the fixed scroll 3 and the end plate 4 is sealed.

  Further, the chip seal 31 is formed using a resin composite material including, for example, polytetrafluoroethylene (PTFE), for example, in the same manner as the chip seal 20 according to the first embodiment. Along the spiral. Further, the tip seal 31 has a substantially square cross-sectional shape as shown in FIGS. 11 and 12, and a bottom surface 31A disposed on the bottom side of the seal groove 12 and the seal groove 12 facing the bottom surface 31A. A seal surface 31B disposed on the opening side, an inner peripheral surface 31C that connects the bottom surface 31A and the seal surface 31B on the inner peripheral side, and an outer peripheral surface 31D that connects the bottom surface 31A and the seal surface 31B on the outer peripheral side are provided. ing.

  The tip seal 31 is formed by changing the shape of a flexible string-like seal body 38 into a spiral shape and mounting it in the seal groove 12, and the curvature is between the inner diameter side and the outer diameter side of the seal groove 12. It has an inner diameter portion 31E mounted on the larger inner diameter side and an outer diameter portion 31F mounted on the outer diameter side having a small curvature.

  Reference numeral 32 denotes a bottom lip portion as a plurality of bottom surface protrusions formed on the bottom surface 31A of the chip seal 31. These bottom lip portions 32 are thin by, for example, making an oblique cut on the bottom surface 31A side of the chip seal 31. It is formed as a lip part, and is arranged at intervals in the length direction (spiral direction) of the tip seal 31.

  And the front end side of the bottom lip portion 32 becomes a free end that expands toward the inner diameter side of the tip seal 31 and obliquely projects from the bottom surface 31A toward the bottom surface 12A of the seal groove 12, and this free end side. Is in elastic contact with the bottom surface 12 </ b> A of the seal groove 12.

  Thus, each bottom lip portion 32 has a plurality of gaps between the bottom surface 31A of the chip seal 31 and the bottom surface 12A of the seal groove 12 at a plurality of positions in the length direction of the chip seal 31 when the compression operation is performed. It shuts off and prevents the compressed air from leaking from the inner diameter side to the outer diameter side of the seal groove 12 through these. Further, the tip seal 31 is pressed in the direction of rising from the seal groove 12 by the compressed air flowing between the bottom lip portions 32 and is in sliding contact with the tooth bottom surface 4 </ b> A of the fixed scroll 3.

  Reference numeral 33 denotes, for example, an inner lip portion as a plurality of side projections formed on the inner peripheral surface 31C of the tip seal 31 at intervals in the spiral direction, and the distal end side of each inner lip portion 33 is substantially the same as the bottom lip portion 32. While expanding toward the inner diameter side of the tip seal 31, it protrudes obliquely from the inner peripheral surface 31C toward the inner wall surface 12B of the seal groove 12 and elastically contacts the inner wall surface 12B.

  Each inner lip portion 33 blocks the gap between the inner peripheral surface 31C of the tip seal 31 and the inner wall surface 12B of the seal groove 12 at a plurality of locations in the length direction of the tip seal 31. Through this, the compressed air is prevented from leaking from the inner diameter side to the outer diameter side of the seal groove 12.

  Further, during the compression operation, the compressed air also flows between the inner lip portions 33 in the seal groove 12. In this case, the pressure of the compressed air gradually increases from the outer diameter side to the inner diameter side of the wrap portion 10. Therefore, when the pressures on the inner peripheral side and the outer peripheral side of the tip seal 31 are compared, Becomes high pressure.

  For this reason, the inner lip 33 is disposed on the inner peripheral surface 31 </ b> C of the tip seal 31, and is configured to easily introduce high-pressure compressed air into the inner peripheral side of the tip seal 31. Thereby, the outer peripheral surface 31D can be stably pressed against the outer wall surface 12C of the seal groove 12 by the high-pressure compressed air flowing into the inner peripheral side of the chip seal 31, and the gap between them can be reliably blocked. Can do.

  On the other hand, the tip seal 31 mounted in the seal groove 7 of the fixed scroll 3 seals the gap between the tooth bottom surface 9A of the turning scroll 8 (end plate 9) as the counterpart, and the tip seal 31 also has the turning scroll. It is configured in the same manner as the 8-side chip seal 31 and has a bottom lip portion 32 and an inner lip portion 33.

  The scroll type air compressor according to the present embodiment has the above-described configuration. Next, a method for manufacturing the tip seal 20 will be described with reference to FIGS.

  First, in the sealing body forming step, as in the first embodiment, a circular string-like sealing body 34 is resin-molded using a resin composite material containing, for example, PTFE or the like. At this time, the sealing body 34 may be formed, for example, by forming a cylindrical body of a resin composite material and then cutting the cylindrical body into a desired thickness.

  Next, in the lip portion forming step, as shown in FIG. 13, the annular seal body 34 is placed on a rotatable disc-shaped rotary table 35. At this time, the center position of the seal body 34 and the rotation center of the rotary table 35 are made to coincide. The seal body 34 is attached to the rotary table 35 in a state where the bottom surface 34 </ b> A serving as the bottom surface 31 </ b> A of the chip seal 31 is exposed and the surface 34 </ b> B serving as the seal surface 31 </ b> B of the chip seal 31 is in contact with the rotary table 35. .

  In this state, the cutter 36 is advanced in the radial direction toward the bottom surface 34 </ b> A of the seal body 34. As a result, the bottom surface 34 </ b> A of the seal body 34 is cut obliquely and a bottom lip portion 32 is formed. On the other hand, the cutter 37 is advanced in the axial direction (upward and downward) toward the inner peripheral surface 34C of the seal body 34 at a position different from the bottom lip portion 32. Thereby, the inner peripheral surface 34 </ b> C of the seal body 34 is cut obliquely and an inner lip portion 33 is formed. When the formation of one set of the bottom lip portion 32 and the inner lip portion 33 is completed, the rotary table 35 is rotated by a certain angle, and the lip portion 32 next to the position different from the lip portions 32 and 33 after the formation is completed. , 33 are formed. By repeating this operation, as shown in FIG. 14, the plurality of lip portions 32 and 33 that are separated in the circumferential direction (length direction) of the seal body 34 are processed over the entire circumference of the seal body 34. Thereafter, the seal body 32 is cut at one place to form a linear string-like seal body 38.

  Next, in the shape changing step, as shown in FIGS. 15 and 16, the string-like seal body 38 formed with the lip portions 32 and 33 is curved in a spiral shape, as in the first embodiment. It is inserted into the spiral groove 24A of the shape changing die 23. And using the shape change type | mold 23 and the press machine 27, while applying the pressure of 30-50 Mpa, for example to the sealing body 38, it heats to about 300-350 degreeC. In this pressurized and heated state, the sealing body 38 is held, for example, for 1 to 2 hours. As a result, the seal body 38 is plastically deformed, and the tip seal 31 that maintains the spiral shape even in the free state is formed. At this time, both the inner diameter portion 31E and the outer diameter portion 31F of the chip seal 31 have a substantially rectangular cross-sectional shape.

  When the above shape changing step is completed, the press die 24 and the male die 25 of the shape changing die 23 are separated, and the chip seal 31 is taken out. Thereby, the spiral shape of the outer shape and the square shape of the cross section are maintained in a free state, and the tip seal 31 including the lip portions 32 and 33 on the bottom surface 31A and the inner peripheral surface 31C is completed.

  Thus, the second embodiment can provide the same effects as those of the first embodiment. In particular, in the second embodiment, since the lip portion forming step for forming the plurality of lip portions 32 and 33 separated in the length direction of the seal body 34 is performed before the shape changing step, By forming the seal body 34 into an annular shape, the cutters 36 and 37 are advanced with respect to the seal body 34 while rotating the annular seal body 34, so that the seal body 34 is easily separated in the length direction. A plurality of lip portions 32 and 33 can be formed. Thereafter, the linear string-like seal body 38 can be formed by cutting the annular seal body 34 at one place. Therefore, by subjecting the string-like seal body 38 to a shape changing step, a spiral-shaped seal body 38 is formed. The chip seal 31 can be manufactured. As a result, compared with the case where the lip portions 32 and 33 are formed after the spiral tip seal 31 is formed, the lip portions 32 and 33 can be easily processed, and the productivity can be improved.

  In the second embodiment, the lip forming step for forming the lip portions 32 and 33 is performed on the circular string-shaped seal body 34. However, the lip is formed on the linear string-shaped seal body. It is good also as a structure which performs the lip formation process to form. Even in this case, the processing operation can be easily performed as compared with processing the lip portion on the spiral chip seal after the shape changing step.

  In the second embodiment, the bottom surface lip portion 32 and the inner lip portion 33 are provided on the bottom surface 34A and the inner peripheral surface 34C of the seal body 34 respectively. Or only one of them may be provided.

  In each of the above embodiments, the chip seals 20 and 31 are formed of a resin composite material such as PTFE. However, the material used for the chip seal of the present invention is not limited to the embodiment. For example, the chip seal may be made of a resin composite material using a material other than PTFE.

  In each of the above embodiments, the tip seals 20 and 31 are provided on the wrap portions 5 and 10 of the fixed scroll 3 and the orbiting scroll 8, respectively. However, the present invention is not limited to this, and a chip seal may be provided on only one of the wrap portions 5 and 10 and the other chip seal may be omitted.

  In each of the above embodiments, a single seal body 22, 38 is inserted into the groove 24A of the shape change mold 23, and a shape change process is performed on each of the seal bodies 22, 38. However, a configuration may be adopted in which a plurality of seal bodies 22 and 38 are inserted into the groove 24A in a stacked state, and a shape changing process is performed on the plurality of seal bodies 22 and 38 together.

  On the other hand, in each of the above-described embodiments, the scroll type air compressor has been described as an example of the scroll type fluid machine. However, the present invention is not limited to this and can be widely applied to, for example, a vacuum pump, a refrigerant compressor, and the like. It is.

It is a longitudinal section showing a scroll type air compressor by an embodiment of the invention. It is sectional drawing which expanded the lap | wrap part of each scroll from the arrow II-II direction in FIG. It is a perspective view shown in the state which decomposed | disassembled the chip seal and the lap | wrap part. FIG. 4 is an enlarged end view of a main part as viewed from the direction of arrows IV-IV in FIG. FIG. 5 is an enlarged end view of a main part as viewed from an arrow VV direction in FIG. 2 showing an outer diameter part of the chip seal. It is a perspective view which shows the state which forms a linear string-shaped seal body from a circular string-shaped seal body. It is a disassembled perspective view which shows the state which inserts a sealing body into the groove | channel of a shape change type | mold. It is sectional drawing seen from the arrow VIII-VIII direction in FIG. 7 which shows the state which performs the shape change process using a shape change type | mold and a press. It is a principal part enlarged end elevation of the position similar to FIG. 4 which shows the internal diameter part of the chip seal by a comparative example. It is a principal part expansion perspective view shown in the state which decomposed | disassembled the chip seal and lap | wrap part by 2nd Embodiment. It is a principal part expanded end elevation of the position similar to FIG. 4 which shows the internal diameter part of the chip seal by 2nd Embodiment. It is a principal part expanded end elevation of the same position as FIG. 5 which shows the outer diameter part of the chip seal by 2nd Embodiment. It is a perspective view which shows the state which forms a lip | rip part in a circular string-like seal body. It is a perspective view which shows the state which forms a linear string-shaped seal body from a circular string-shaped seal body. It is a disassembled perspective view which shows the state which inserts a sealing body into the groove | channel of a shape change type | mold. It is sectional drawing of the same position as FIG. 8 which shows the state which performs the shape change process using the shape change type | mold and a press.

Explanation of symbols

3 fixed scroll 4,9 end plate 4A, 9A tooth bottom surface 5,10 lap portion 5A, 10A tooth tip surface 7,12 seal groove 7A, 12A bottom surface 7B, 12B inner wall surface 7C, 12C outer wall surface 8 orbiting scroll 17 compression chamber 20, 31 Chip seal (seal member)
20A, 31A Bottom surface 20B, 31B Seal surface 20C, 31C Inner peripheral surface 20D, 31D Outer peripheral surface 20E, 31E Inner diameter portion 20F, 31F Outer diameter portion 21, 22, 34, 38 Seal body 23 Shape change mold 26 Heater 27 Press machine 32, 33 Lip part 35 Rotary table 36, 37 Cutter

Claims (2)

In the manufacturing method of the seal member attached to the spiral wrap portion formed in the scroll,
Inserting a string-like seal body made of a resin composite material into a spiral groove of a shape-changing mold, and performing a shape-changing step of heating the seal body in a pressurized state to form a spiral seal member The manufacturing method of the sealing member characterized by these. In the manufacturing method of the seal member attached to the spiral wrap portion formed in the scroll,
Using a cutter, cut at least one side of a string-like seal body made of a resin composite material, and perform a lip portion forming step to form a plurality of lip portions spaced apart in the length direction of the seal body,
Next, the seal body in which the lip portion is formed is inserted into the spiral groove of the shape changing mold, and a shape changing step is performed in which the seal body is heated in a pressurized state, thereby forming a spiral seal member. The manufacturing method of the sealing member characterized by the above-mentioned.

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