JPH0953563A - One-sided piston variable volume compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the weight of a piston, reduce a manufacturing cost, and improve high speed controllability by integrally forming the piston out of synthetic resin having a thermal deformation temperature higher than a specified temperature. SOLUTION: A cylinder bore 39 is extended through a cylinder block 11 and a single head piston 40 is contained in a cylinder bore 39. Rotational movement of swash plate 23 is converted into longitudinal reciprocation movement of the single head piston 40 through a shoe 41. The single head piston 40 is longitudinally moved in the cylinder body 39. In which case, the single head piston 40 is formed as a solid body through injection-molding by using synthetic resin, such as a polyimide raw material, having a thermal deformation temperature of 150 deg.C or more. The peripheral temperature of the single head piston 40 is 150 deg.C or less. Even when the increase of the temperature of the single head piston 40 due to disturbance of the single head piston 40 and the cylinder bore 39 is taken into consideration, there is hardly any fear of thermal deformation occurring the single head piston 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-sided piston type variable displacement compressor used in, for example, a vehicle air conditioner.

[0002]

2. Description of the Related Art In a compressor of this type, a plurality of pistons reciprocate in a cylinder bore formed in a cylinder block by rotation of a cam plate which is integrally rotatable with a drive shaft and is tiltably inserted. 2. Description of the Related Art In recent years, as the performance of an engine, which is an external drive source of a compressor, has become higher, the upper limit of its rotational speed has become higher and higher, and the compressor is often operated under high speed rotation. In the operation under such high speed rotation, the inertial force due to the reciprocating motion of the piston increases, and the inertial force acts in the direction of increasing the inclination angle of the cam plate. In addition, due to the increase in compression reaction force due to the recent trend of increasing the number of cylinders in compressors, a delay may occur in the transition from maximum capacity operation to minimum capacity operation. Under such circumstances, improvement of high-speed controllability of the compressor is required. In other words, there is a demand for a compressor that can quickly control the compression capacity even when rotating at high speed.

Particularly, in a clutchless variable displacement compressor, an external drive source and a drive shaft are always operatively connected. Even when there is no cooling load, the piston is reciprocated and the refrigerant gas is circulated in the compressor while keeping the cam plate in the minimum inclination state and disconnected from the external refrigerant circuit. Therefore, if the mass of the piston is heavy and the high-speed controllability is insufficient, the disconnection between the external refrigerant circuit and the inside of the compressor becomes insufficient, and the circulation of the refrigerant gas occurs between the external refrigerant circuit and the inside of the compressor. However, there is an inconvenience such as the occurrence of frost in the evaporator or the like of the external refrigerant gas circuit.

In order to solve such a problem, for example, in a variable displacement type swash plate compressor disclosed in Japanese Utility Model Laid-Open No. 109481/1992, the entire piston is made of an aluminum alloy, and the piston is hermetically sealed in its main body. The structure which provided the hollow part of this is disclosed. In this compressor, the weight of the piston is reduced, the inertial force associated with the reciprocating motion of the piston can be suppressed to a low level, and the relative mass of the swash plate is increased.
It is capable of responding sensitively to changes in capacity.

[0005]

However, in the compressor described in the above publication, since the piston main body has a hollow structure, the main body is cast as a plurality of parts, which are welded and then further polished. It is necessary to form the main body. For this reason, there is a problem in that it takes time and labor to manufacture the piston, which leads to cost increase, and eventually leads to an increase in cost of the entire compressor.

An object of the present invention is to provide a one-sided piston type variable displacement compressor which has a light weight piston, reduces the manufacturing cost thereof, and is excellent in high-speed controllability.

[0007]

In order to achieve the above object, in the invention of claim 1, the piston is integrally formed of a synthetic resin having a heat deformation temperature of 150 ° C. or higher.

In the invention of claim 2, the piston is set to 20
It is formed of a synthetic resin having a heat distortion temperature of 0 ° C. or higher. In the invention of claim 3, the piston is formed by containing a solid lubricant.

According to a fourth aspect of the invention, the piston is formed by containing a filler for reinforcement. According to the invention of claim 5, the piston is provided with a meat stealing portion.

According to a sixth aspect of the invention, the compressor is a clutchless compressor in which an external drive source and a drive shaft are constantly operatively connected. Therefore, according to the first aspect of the present invention, the weight of the piston can be reduced without forming the hollow structure of the piston unlike the conventional metal piston. Here, the piston body can be integrally formed by, for example, injection molding or the like, and it is not necessary to join a plurality of members by welding or the like. Therefore, the number of manufacturing steps can be reduced as compared with a metal piston, which leads to a reduction in manufacturing cost.

Further, in the one-sided piston type variable displacement compressor in which such a lightweight piston is incorporated, the inertial force due to the reciprocating motion of the piston can be suppressed to a low level. That is,
The inertial force acting in the direction of increasing the inclination angle of the cam plate can be reduced. Therefore, even when the cam plate is rotating at a high speed, the cam plate is smoothly moved to the minimum tilt side. Further, since the piston has a thermal deformation temperature of 150 ° C. or higher, there is almost no risk of thermal deformation of the piston even when the ambient temperature around the piston is taken into consideration.

According to the second aspect of the present invention, the heat resistance of the piston is further improved, and therefore the risk of thermal deformation of the piston is further eliminated. According to the invention of claim 3, the slidability on the sliding surface between the piston and the cylinder is improved.

According to the invention of claim 4, the strength, wear resistance and heat resistance of the piston are further improved. According to the invention of claim 5, the weight of the piston can be further reduced, the amount of the raw material resin used can be reduced, and the piston can be made inexpensive. Further, the sliding area of the piston with respect to the inner peripheral surface of the cylinder can be reduced, and the slidability of the piston is improved.

According to the sixth aspect of the present invention, in the clutchless variable displacement compressor in which the external drive source is rotating at high speed and there is no cooling load, the cam plate is reliably held in the minimum inclination state. You can Therefore, it is possible to surely disconnect the compressor from the external refrigerant circuit.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIG.

The front housing 12 forming a part of the casing is joined to the front end of the cylinder block 11. Rear housing 1 forming part of the casing
3 is joined to the rear end of the cylinder block 11 via a valve plate 14. The crank chamber 15 is defined between the front housing 12 and the cylinder block 11. The drive shaft 16 passes through the crank chamber 15 so that the front housing 12 and the cylinder block 11 are
It is erected and supported between and. The front end of the drive shaft 16 protrudes from the crank chamber 15 to the outside, and the pulley 1
7 is fixed to this protruding end. The pulley 17 is directly connected to a vehicle engine (not shown) via a belt 18 without an electromagnetic clutch. The pulley 17 has a front housing 1 via an angular bearing 19.
Supported by 2. The load in the thrust direction and the load in the radial direction that act on the pulley 17 are received by the front housing 12 via the angular bearing 19.

The lip seal 20 is interposed between the front end of the drive shaft 16 and the front housing 12. The lip seal 20 prevents pressure leakage in the crank chamber 15.

The rotary support 22 is fixed to the drive shaft 16 so as to rotate integrally therewith. The swash plate 23 as a cam plate is supported on the drive shaft 16 so as to be slidable and tiltable in the axial direction.

The spherical connecting body 24 is fixed to the swash plate 23 via a connecting piece 28. The rotary support 22 is fixed to the drive shaft 16 and is supported on the inner wall surface of the front housing 12 via a thrust bearing 49.

The support arm 25 is provided so as to project from the rotary support 22, and a guide hole 26 is formed at the tip of the support arm 25. The spherical connecting body 24 is slidably fitted in the guide hole 26. The swash plate 23 can rotate integrally with the drive shaft 16 due to the linkage between the support arm 25 and the spherical coupling body 24. The tilting of the swash plate 23 is guided by the slide guide relationship between the guide hole 26 and the spherical connecting body 24.

The tilt angle reducing spring 27 is interposed between the rotary support 22 and the swash plate 23, and biases the swash plate 23 in a direction to reduce its tilt angle. The maximum tilt angle of the swash plate 23 is restricted by the contact between the tilt restriction projection 29 of the rotary support 22 and the swash plate 23.

The accommodating hole 30 is provided at the center of the cylinder block 11. The cylindrical spool 31 is slidably accommodated in the accommodation hole 30. The spool 31 includes a large diameter portion 31a and a small diameter portion 31b, and the suction passage opening spring 32 is interposed between the step between the large diameter portion 31a and the small diameter portion 31b and the end surface of the accommodation hole 30.
1 is urged toward the swash plate 23 side.

The rear end of the drive shaft 16 has a spool 3
It is inserted inside 1. Radial bearing 33
Is fitted between the large diameter portion 31a of the spool 31 and the drive shaft 16, and is prevented from coming out of the spool 31 by a circlip 34 attached to the inner peripheral surface of the large diameter portion 31a. . The rear end of the drive shaft 16 is supported by the circumferential surface of the accommodation hole 30 via the radial bearing 33 and the spool 31. The radial bearing 33 can slide on the drive shaft 16.

The suction passage 35 is formed at the center of the rear housing 13 and communicates with the accommodation hole 30. The spool 31 can come into contact with the positioning surface 36 at the inner end of the accommodation hole 30.

The thrust bearing 38 is slidably supported on the drive shaft 16 between the swash plate 23 and the spool 31. As the swash plate 23 moves to the spool 31 side, the movement is transmitted to the spool 31 via the thrust bearing 38. Therefore, the spool 31
The positioning surface 3 against the spring force of the suction passage opening spring 32.
The blocking surface 37 of the spool 31 abuts on the positioning surface 36. The rotation of the swash plate 23 is hardly transmitted to the spool 31 due to the presence of the thrust bearing 38.

The cylinder bore 39 is the cylinder block 1
1 and a single-headed piston 40 is housed in the cylinder bore 39. The rotational movement of the swash plate 23 is converted into a forward / backward reciprocating movement of the single-headed piston 40 via the shoe 41, and the single-headed piston 40 moves back and forth in the cylinder bore 39.

Here, the single-headed piston 40 in this embodiment is made of synthetic resin having a heat distortion temperature of 150 ° C. or higher,
For example, it is formed as a solid body by injection molding using a resin material based on a polyimide-based raw material. The ambient temperature of the single-headed piston is 150 ° C. or lower, and even if the temperature rise of the single-headed piston 40 due to the sliding of the single-headed piston 40 and the cylinder bore 39 and the like is taken into consideration, the single-headed piston 40 has a heat deformation temperature of 150 ° C. or higher. If so, there is almost no fear of thermal deformation.

Further, a piston 40 made of the above synthetic resin
The solid lubricant, such as graphite, which enhances the slidability of the piston 40, and the filler, which enhances the strength, such as carbon fiber, are mixed in the core 40. In addition to heat resistance, strength, slidability and Wearability is also enhanced. As a result, high temperature,
Even at the top of the piston where high pressure acts, the piston is not deformed or deteriorated, and wear due to sliding can be suppressed.

When the piston 40 is constructed as described above, the weight of the piston can be reduced and the molding thereof can be facilitated as compared with the case of using a metal. The suction chamber 42 and the discharge chamber 45 are partitioned and formed in the rear housing 13. The suction port 43 and the discharge port 46 are formed on the valve plate 14. The intake valve 44 and the discharge valve 47 are provided on the valve plate 14. The refrigerant gas in the suction chamber 42 pushes the suction valve 44 away from the suction port 43 by the returning motion of the single-headed piston 40 and flows into the cylinder bore 39.
The refrigerant gas flowing into the cylinder bore 39 is discharged from the discharge port 46 to the discharge chamber 45 by pushing the discharge valve 47 away from the discharge port 46 by the forward movement of the single-headed piston 40. The opening of the discharge valve 47 is regulated by contacting the retainer 48 of the retainer forming plate.

From the cylinder bore 39 to the single-headed piston 40,
The compression reaction force acting on the rotary support 22 via the shoe 41, the swash plate 23, and the spherical connecting body 24 is applied to the thrust bearing 4
It is received by the inner wall surface of the front housing 12 via 9.

The suction chamber 42 is accommodated in the accommodation hole 30 through the through hole 50.
Is in communication with. When the spool 31 comes into contact with the positioning surface 36, the passage 50 is blocked from the suction passage 35. A passage 51 is formed in the drive shaft 16. Passage 5
The inlet 52 of 1 is near the lip seal 20 and the crank chamber 15
The outlet of the passage 51 opens to the inside of the spool 31. The pressure release port 53 is provided through the front end surface of the spool 31. The pressure release port 53 communicates the inside of the spool 31 with the accommodation hole 30.

The discharge chamber 45 and the crank chamber 15 are connected by a pressure supply passage 54. The electromagnetic opening / closing valve 55 is interposed on the pressure supply passage 54. The valve body 57 closes the valve hole 58 by exciting the solenoid 56 of the electromagnetic opening / closing valve 55. When the solenoid 56 is demagnetized, the valve body 57 opens the valve hole 58. That is, the electromagnetic opening / closing valve 55 opens / closes the pressure supply passage 54 that connects the discharge chamber 45 and the crank chamber 15.

The suction passage 35 serving as an inlet for introducing the refrigerant gas into the suction chamber 42 and the discharge port 59 for discharging the refrigerant gas from the discharge chamber 45 are connected by an external refrigerant circuit 60.
The condenser 61, the expansion valve 62 and the evaporator 63 are provided on the external refrigerant circuit 60. The expansion valve 62 is a temperature-type automatic expansion valve that controls the refrigerant flow rate according to the fluctuation of the gas temperature on the outlet side of the evaporator 61. The temperature sensor 64 is the evaporator 63.
It is installed near. The temperature sensor 64 is the evaporator 63.
The temperature detected at is detected, and the detected temperature information is sent to the control computer C.

The solenoid 56 of the electromagnetic opening / closing valve 55 is subjected to the excitation / demagnetization control of the control computer C. The control computer C controls the demagnetization of the solenoid 56 based on the detected temperature information obtained from the temperature sensor 64.

In the state of FIG. 1, the solenoid 56 is in the excited state and the pressure supply passage 54 is closed. Therefore,
The high pressure refrigerant gas is not supplied from the discharge chamber 45 to the crank chamber 15. In this state, the refrigerant gas in the crank chamber 15 just flows out to the suction chamber 42 through the passage 51 and the pressure release passage 53, and the pressure in the crank chamber 15 is low pressure in the suction chamber 42, that is, suction pressure. Approaching. Therefore, the swash plate 15 also acts on the spring force of the suction passage opening spring 32 and is urged in the tilt angle increasing direction against the spring force of the tilt angle reducing spring 27. The maximum tilt angle of the swash plate 23 is restricted by the contact between the tilt restriction projection 29 of the rotary support 22 and the swash plate 23. The tilt angle of the swash plate 23 is maintained at the maximum tilt angle, and the discharge capacity becomes the maximum.

When the swash plate 23 maintains the maximum inclination angle and the discharge operation is performed in the state where the cooling load is eliminated, the temperature in the evaporator 63 decreases so as to approach the temperature at which frost is generated. The temperature sensor 64 sends the temperature information detected by the evaporator 63 to the control computer C, and when the detected temperature becomes equal to or lower than the set temperature, the control computer C commands the demagnetization of the solenoid 56. When the solenoid 56 is demagnetized, the pressure supply passage 54 opens, and the discharge chamber 45 and the crank chamber 15 communicate with each other. Therefore, the high-pressure refrigerant gas in the discharge chamber 45 is supplied to the crank chamber 15 via the pressure supply passage 54, and the pressure in the crank chamber 15 increases. The increase in pressure in the crank chamber 15 causes the inclination angle of the swash plate 23 to shift to the minimum inclination angle. Further, the control computer C demagnetizes the solenoid 56 based on the OFF signal of the air conditioner operation switch 65, and this demagnetization shifts the swash plate 23 to the minimum tilt angle.

When the swash plate 23 moves to the minimum tilt side, the spool 31 moves to the positioning surface 36 side. Therefore, the amount of the refrigerant gas sucked from the suction chamber 42 into the cylinder bore 39 also decreases, and the discharge capacity decreases.

When the spool 31 comes into contact with the positioning surface 36, the passage cross-sectional area in the suction passage 35 becomes zero, and the refrigerant gas from the external refrigerant circuit 60 to the suction chamber 42 is blocked. Therefore, the minimum inclination angle of the swash plate 23 is regulated by the contact between the spool 31 and the positioning surface 36.

The minimum inclination angle of the swash plate 23 is slightly larger than 0 °. That is, since the minimum tilt angle of the swash plate 23 is not 0 °, even if the swash plate tilt angle is the minimum, the cylinder bore 39
The refrigerant gas is being discharged from the discharge chamber 45 to the discharge chamber 45. The refrigerant gas discharged from the cylinder bore 39 into the discharge chamber 45 flows into the crank chamber 15 through the pressure supply passage 54.
The refrigerant gas in the crank chamber 15 passes through the passage 51 and the pressure release port 5.
The refrigerant gas flows into the suction chamber 42 through the pressure release passage 3 and the refrigerant gas in the suction chamber 42 is sucked into the cylinder bore 39 and discharged into the discharge chamber 45. That is, when the swash plate tilt angle is at a minimum, the discharge chamber 45, the pressure supply passage 54,
A circulation passage is formed in the compressor through the crank chamber 15, the passage 51, the pressure release port 53, the accommodation hole 30 which is the suction pressure region, the suction chamber 42 which is the suction pressure region, and the cylinder bore 39. Therefore, the refrigerant gas circulates in the circulation passage to lubricate the sliding portion inside the compressor.

During the rotation of the swash plate 23, the centrifugal force of the swash plate 23 exerts a force in the direction in which the inclination angle of the swash plate 23 decreases, and the inertia force of the piston 40 causes the swash plate 23 to rotate. The force also acts in the direction of increasing the inclination angle of 23. When the rotation of the swash plate 23 is low, the inertial force of the piston 40 does not significantly affect the tilting operation of the swash plate 23. However, when the swash plate 23 rotates at a high speed, the inertial force becomes large, and particularly when the mass of the piston 40 is large, a very large inertial force acts. Here, when the mass of the piston 40 is large, if the rotation of the swash plate 23 is high, the control computer C when the swash plate 23 is rotating in the maximum inclination state.
Control of the crank chamber 1 to reduce the inclination angle of the swash plate 23.
Even if the pressure of 5 is increased, the reaction is delayed due to the influence of inertial force, and the tilt angle cannot be immediately reduced. That is, the responsiveness may be very poor.

However, the piston 40 in this embodiment is made lighter than the piston made of metal because the piston 40 is made of resin, and the influence of inertial force is suppressed to a low level. Therefore, the responsiveness of the swash plate 23 to the pressure increase in the crank chamber 15 for reducing the tilt angle is improved, and the transition to the minimum tilt angle state is smoothly performed.

Further, such a resin piston 40 is used.
Is integrally formed by injection molding, so casting, welding,
It is easier to manufacture than a metal piston that requires a plurality of steps such as polishing, and the cost can be reduced.

Further, in the clutchless compressor, the swash plate 23 is kept in the minimum inclination state even when there is no cooling load, and the piston 40 reciprocates to discharge the refrigerant gas.
Therefore, when the mass of the piston 40 is large, when the rotation of the swash plate 23 is high, the inertial force of the piston 40 due to this movement acts in the direction of increasing the inclination angle of the swash plate 23, and There is a risk that the tilted state will not be maintained completely. Here, if this minimum inclination state is not maintained, the blocking surface 37 of the spool 31 separates from the positioning surface 36, and the refrigerant gas circulates between the external refrigerant circuit 60 and the compressor. Then, the evaporator 63 of the external refrigerant circuit 60
May cause frost.

However, in the piston 40 according to the present embodiment, the piston 40 is made of synthetic resin as described above, so that the piston 4 is made smaller than the case of being made of metal.
The weight is reduced to 0, and the influence of inertial force is kept low. Therefore, the swash plate 23 is reliably held in the minimum inclination state, the suction passage 35 remains closed, and the refrigerant gas does not circulate between the external refrigerant circuit 60 and the compressor. Therefore, there is no possibility that frost will occur in the evaporator 63. Further, since the resin piston 40 is integrally formed by injection molding, it is easier to manufacture as compared with a metal piston, and the cost can be reduced. (Second Embodiment) A second embodiment of the present invention will be described below with reference to FIGS.

In the second embodiment, the structure of the single-headed piston 71 is different. That is, two meat recesses 72 are recessed on the drive shaft 16 side of the piston 40 of the first embodiment. The meat-thief portion 72 is easily formed by a ridge in a mold or a core arranged in the mold during injection molding.

With this structure, the weight of the piston is further reduced as compared with the piston 40 of the first embodiment, and the influence of inertial force can be further reduced. or,
At the time of forming the piston 71, the amount of raw material resin used can be reduced, and the piston 71 can be made inexpensive. Further, since the meat-throwing portion 72 is present, the sliding area with the inner peripheral surface of the cylinder is reduced, and the slidability of the piston is improved.

The present invention is not limited to the above-described embodiment, and the configuration of each part can be modified and embodied as follows. (1) The pistons 40, 71 are made of, for example, polyamideimide, polyphenylene sulfide, polyetherimide, polyethersulfone, polyetheretherketone, aromatic polyamide, polyarylate, polybenzimidazole, polyoxybenzothiazole, polyoxytetrafluoro. It is made of synthetic resin such as ethylene-hexafluoropropylene copolymer resin, tetrafluoroethylene-hexafluoropropylene copolymer resin, tetrafluoroethylene-perfluoroalkyl vinyl vinyl ether copolymer resin, hot-melt liquid crystal polyester resin, epoxy resin, etc. thing.

(2) The pistons 40 and 71 are compression-molded with polytetrafluoroethylene at room temperature,
To be formed by firing. (3) The pistons 40, 71 contain, for example, molybdenum disulfide, tungsten disulfide, graphite fluoride, polytetrafluoroethylene, calcium fluoride or the like as a lubricant for improving slidability.

(4) The pistons 40, 71 are made to contain, for example, glass fiber, aramid fiber, alumina fiber, silicon carbide fiber, silicon carbide whisker, titanium potassium oxide whisker as a reinforcing filler.

(5) Meat stealing portion 72 of the piston 71
Are provided in a radial pattern with respect to the central axis of the piston 71. (6) After the piston 40 is injection-molded into a solid shape, the meat-thief portion 72 is formed by cutting.

(7) Applying the pistons 40, 71 to a one-sided piston type compressor with a clutch. (8) The pistons 40, 71 are made of synthetic resin having a heat distortion temperature of 200 ° C. or higher.

The technical idea understood from the above embodiment will be described below. (1) The one-sided piston variable displacement compressor according to claim 1, wherein the synthetic resin having a heat distortion temperature of 150 ° C. or higher is preferably polyimide or polyamide-imide.

According to this structure, the heat resistance and strength of the piston can be sufficiently secured, and the piston can be easily molded. (2) The piston is formed by injection molding.
6. The one-sided piston type variable displacement compressor according to any one of 6 above.

With this structure, the piston can be easily manufactured.

[0055]

As described above in detail, according to the invention of claim 1, since the piston is integrally formed of synthetic resin having a heat distortion temperature of 150 ° C. or more, the weight of the piston can be easily reduced. The inertial force due to the reciprocating motion of the piston can be suppressed to a low level. Therefore, the influence of the inertial force on the cam plate is reduced, and the high speed controllability of the compressor is improved. In addition, compared to a metal piston, the labor required for manufacturing is reduced, and the cost of the piston and the compressor as a whole is reduced. Moreover, there is no problem with the heat resistance of the piston.

According to the second aspect of the invention, the piston is 20
Since it is made of a synthetic resin having a heat distortion temperature of 0 ° C. or higher, the heat resistance of the piston is further improved. According to the invention of claim 3, since the piston is formed by containing the solid lubricant, the slidability on the sliding surface between the piston and the cylinder is improved.

According to the invention of claim 4, since the piston is formed by containing a filler for reinforcement, the strength, wear resistance and heat resistance of the piston are further improved. According to the fifth aspect of the invention, since the piston is provided with the meat-thickness portion, the weight and cost of the piston can be further reduced. It also leads to a reduction in sliding resistance between the piston and the cylinder.

According to the sixth aspect of the invention, even when the drive shaft is rotated at a high speed, the disconnection between the inside of the compressor and the external refrigerant circuit is ensured during the minimum capacity operation. Therefore, it is suitable for a clutchless compressor in which an external drive source and a drive shaft are always operatively connected.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an entire compressor of a first embodiment.

FIG. 2 is a perspective view showing a single-headed piston according to a second embodiment.

FIG. 3 is a longitudinal sectional view of the single-headed piston shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Cylinder block, 12 ... Front housing which comprises a part of casing, 13 ... Rear housing which comprises a part of casing, 15 ... Crank chamber, 16 ... Drive shaft, 23 ... Swash plate as a cam plate, 39 ... Cylinder bore, 40, 71 ... Single-headed piston, 72 ... Meat stealing part.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiko Okada 2-1-1, Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation

Claims (6)

[Claims] 1. A plurality of cylinder bores for accommodating a reciprocating single-headed piston are formed in a cylinder block of a casing, a crank chamber is formed in the casing, and a cam plate is integrated with a drive shaft supported by the casing. It is rotatably inserted, and the piston is reciprocated by the rotation of the cam plate to compress the refrigerant gas, and the inclination angle of the cam plate is determined according to the pressure difference between the pressure in the crank chamber and the suction pressure region. In the one-sided piston type variable displacement compressor for controlling the compression capacity by changing the above, a one-sided piston type variable displacement compressor in which the piston is integrally formed of a synthetic resin having a heat deformation temperature of 150 ° C. or higher. 2. The one-sided piston type variable displacement compressor according to claim 1, wherein the piston is formed of a synthetic resin having a heat distortion temperature of 200 ° C. or higher. 3. The one-sided piston type variable displacement compressor according to claim 1, wherein the piston contains a solid lubricant. 4. The one-sided piston type variable displacement compressor according to claim 1, wherein the piston contains a filler for reinforcement. 5. The one-sided piston type variable displacement compressor according to claim 1, wherein the piston is provided with a meat stealing portion. 6. The one-sided piston variable displacement compressor according to claim 1, wherein the compressor is a clutchless variable displacement compressor in which an external drive source and a drive shaft are constantly operatively connected. .