WO1999030035A1

WO1999030035A1 - Variable displacement compressor

Info

Publication number: WO1999030035A1
Application number: PCT/JP1997/004537
Authority: WO
Inventors: Kazuya Kimura; Hiroaki Kayukawa; Hideki Mizutani; Shigeyuki Hidaka
Original assignee: Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
Priority date: 1997-12-10
Filing date: 1997-12-10
Publication date: 1999-06-17
Also published as: DE19782257T1

Abstract

A swash plate (18) can rotate together with a drive shaft (16) through a rotating support (17) and a hinge mechanism (20), and rotation of the drive shaft (16) is converted into reciprocating motion of a piston (23). Guiding provided by the hinge mechanism (20) and a slide supporting action provided by the drive shaft (16) through a through hole (19) permit the swash plate (18) to incline while moving slidingly on the drive shaft (16), and a change in an inclination angle modifies a stroke of the piston (23) for regulation of delivery capacity. An arcuate-shaped support (19a) abuts against the drive shaft (16) to subject the swash plate (18) to the slide supporting action provided by the drive shaft (16). An axis (S) being the center of an arc for the support (19a) is set to be beyond the drive shaft (16) on a side opposite to the hinge mechanism (20) with an axis (L) of the drive shaft (16) therebetween, and defines the center of inclination of the swash plate (18). The support (19a) is increased in hardness by induction hardening to be improved in durability in pressure contact and sliding relative to a peripheral surface of the drive shaft (16).

Description

Akira Itoda

Variable displacement compressor

. [Technical field]

The present invention relates to a variable displacement compressor applied to, for example, a vehicle air conditioning system and capable of changing a stroke of a piston by changing a tilt angle of a cam plate to adjust a discharge capacity.

[Background technology]

As this type of compressor, for example, there is one as disclosed in Japanese Patent Application Laid-Open No. 7-91636 proposed by the present applicant. That is, as shown in FIG. 7, the drive shaft 102 is rotatably supported by the housing 101. The rotating support 103 is fixed to the drive shaft 102. The swash plate 104 serving as a cam plate has an A through hole 105 formed in the center of the swash plate 104, and the drive shaft 102 is inserted into the through hole 105. The piston 106 is accommodated in a cylinder bore 101a provided in a housing 101, and is moored to a swash plate 104 via a shoe 108.

The hinge mechanism 109 is interposed between the rotating support 103 and the swash plate 104. That is, the guide bin 110 is provided near the top dead center position D of the swash plate 104. The spherical portion 110a is formed at the tip of the guide bin 110. The support arm 111 is provided on the rotary support 103 so as to face the guide bin 110. The guide hole 111a is formed in the support arm 111. The guide bin 110 is inserted into the guide hole 111a of the support arm 111 with a spherical portion 110a. The support portion 105a is provided on the inner surface of the through hole 105 on the side facing the hinge mechanism 109 with the axis L of the drive shaft 102 interposed therebetween. The support portion 105a has an arc shape centered on the axis S.

The swash plate 104 is rotatable integrally with the drive shaft 102 via a rotation support 103 and a hinge mechanism 109. The swing of the swash plate 1_04 back and forth in the direction of the axis L due to the rotation of the drive shaft 102 is converted into a reciprocating motion of the piston 106 via the shoe 108, and the refrigerant gas is compressed in the cylinder bore 101a. The swash plate 104 is connected through a slide guide relationship between the spherical portion 110a of the hinge mechanism 109 and the guide hole 111a, and through a through hole 105 formed by the drive shaft 102. Due to the sliding support function, it can be tilted while sliding along the axis L. When the inclination angle of the swash plate 104 is changed, the stroke of the piston 106 is changed, and the discharge capacity is adjusted.

Here, during operation of the compressor, a load K is applied to the piston 106 by the compression of the refrigerant gas, and the compressed load K is transmitted through the swash plate 104 and the spherical portion 110a of the guide bin 110 to the guide hole. Acts on the inner surface of the rotating support 103 side of 111a. The guide bin 110 receives the reaction force F of the compressive load K from the guide hole 111a. The guide hole 111a extends toward the swash plate 104 side so as to approach the axis L of the drive shaft 102 from the outside. Accordingly, the reaction force F acting on the guide bin 110 generates a component force f in the direction of shifting the swash plate 104 toward the top dead center position D with respect to the drive shaft 102. For this reason, the swash plate 104 is in a state where the support portion 105a of the through hole 105 is pressed against the peripheral surface of the drive shaft 102 during the operation of the compressor.

When the capacity of the compressor is changed, the swash plate 104 is tilted while sliding on the drive shaft 102 with the support portion 105a pressed against the peripheral surface of the drive shaft 102. That is, the swash plate 104 is tilted about the arc-shaped center axis S of the support portion 105a. In other words, the swash plate 104 is tilted about the axis S set beyond the drive shaft 102 on the side facing the hinge mechanism 109 with the axis L interposed therebetween.

In the technique disclosed in Japanese Patent Application Laid-Open No. Hei 7-911366, the support and guide of the swash plate 104 by the drive shaft 102 are directly performed via the support portion 105a of the through hole 105. Therefore, as the effects, for example, the following description is made in the column of “Effects of the Invention” in the publication. As in the prior art (the technology of Japanese Patent Application Laid-Open No. 4-159644), a sleeve (disposed on the drive shaft so as to be able to slide) between the swash plate and the drive shaft and a (It is projected and supports the swash plate so that it can be tilted.) Since there is no need to provide a pivot pin, it is possible to reduce the number of parts, thereby reducing manufacturing costs and facilitating parts management. be able to. "

However, according to the technology disclosed in Japanese Patent Application Laid-Open No. H07-9-11366, during operation of the compressor, the supporting capital 105a is pressed against the peripheral surface of the drive shaft 102 and receives an excessive load. During the capacity change, the support portion 105a slides on the peripheral surface of the drive shaft 102. Therefore, the support portion 105a was easily worn and deformed, and could not maintain an arc shape centered on the axis S for a long period of time. As a result, the tilt center is shifted from the axis S, and the swash plate 104 may be adjusted to a different tilt angle from the desired tilt angle, and the displacement control cannot be performed accurately.

In recent years, it has been proposed that the swash plate 104 be made of aluminum to reduce the weight of the compressor. However, the strength of the swash plate 104 made of an aluminum material is lower than that of a swash plate 104 made of an iron-based material.

SUMMARY OF THE INVENTION An object of the present invention is to provide a variable displacement compressor in which the support and guide of a cam plate by a drive shaft are directly performed via a support on the lower surface of a through hole, and the durability of the support is improved. Is to do.

[Disclosure of the Invention]

In the variable displacement compressor according to the present invention, an arc-shaped support portion is formed on the inner surface of the through-hole in the cam plate to be in contact with the drive shaft and receive a slide support operation by the drive shaft, and the arc-shaped support portion has an arc shape. The center axis of the cam plate is set beyond the drive shaft on the side facing the hinge mechanism with the axis of the drive shaft interposed, and forms the center of tilt of the cam plate, and the support is hardened.

In this configuration, the cam plate is tilted about the axis of the support portion while sliding on the drive shaft by the guide of the hinge mechanism and the slide support action of the drive shaft through the support portion of the through hole. You. By changing the cam plate tilt angle, the stroke of the biston is changed, and the discharge capacity is adjusted. The hardness of the supporting portion is increased by a hardening process, and the durability against pressure contact and sliding with the drive shaft is improved.

The hardening process is a quenching process.

In this configuration, the hardness of the support portion is increased by quenching. The quenching process is performed by 髙 -frequency quenching. In this configuration, the support portion is quenched by induction hardening. The hardening process is performed on substantially the entire inner surface of the through hole.

In this configuration, the hardening process is applied to the entire inner surface of the through-hole, resulting in a hardening process applied to the support section, which is simpler and more reliable compared to performing the hardening process only on the support section. .

The cam plate is made of aluminum.

In this configuration, for example, the cam plate is lighter in weight than that made of an iron-based material, and the hardened support portion is made of, for example, aluminum alloy having a lower strength than that of an iron-based material. A decrease in durability due to the use of a rubber material is prevented.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a variable displacement compressor according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1, with the drive shaft cut away.

FIG. 3 is an explanatory diagram showing a state in which the discharge capacity is minimized.

FIG. 4 is an enlarged view of the vicinity of the support portion of the through hole in FIG.

Fig. 5 is a front view showing the swash plate extracted from Fig. 1.

FIG. 6 is a diagram illustrating induction hardening performed on a through hole of a swash plate.

FIG. 7 is an enlarged cross-sectional view of a main part showing a compressor disclosed in Japanese Patent Application Laid-Open No. 7-911366.

[Best Mode for Carrying Out the Invention]

Hereinafter, an example in which the present invention is embodied in a variable displacement compressor applied to a vehicle air conditioning system will be described with reference to FIGS.

As shown in 囪 1, the front housing 11 is joined and fixed to the front end of the cylinder block 12. The rear housing 13 is joined and fixed to the rear end of the cylinder block 12 via a valve forming body 14. The crank chamber 15 is defined by being surrounded by the front housing 11 and the cylinder block 12. The drive shaft 16 passes through the crankcase 15 through the front housing 11 and the cylinder block 1 2 And rotatably supported between them. The drive shaft 16 is connected to a vehicle engine (not shown) as an external drive source via a clutch mechanism such as an electromagnetic clutch. Therefore, the drive shaft 16 is rotationally driven by the connection of the clutch mechanism when the vehicle engine is started.

The rotary support 17 is fixed to the drive shaft 16 in the crank chamber 15. The swash plate 18 as a force plate is made of an aluminum material (including one made of an aluminum alloy) and housed in the crankcase 15. The drive shaft 16 is inserted through a through-hole 19 provided at the center of the swash plate 18. The hinge mechanism 20 is interposed between the rotary support 17 and the swash plate 18.

As shown in FIG. 2, in order to form the through hole 19, first, drilling is performed along the center line 1 to form a circular hole in the center of the swash plate work. Insert an end mill of approximately the same diameter into the circular hole, and rotate it around the axis S in the forward and reverse directions within a predetermined angle range while rotating it. The axis S extends in a direction perpendicular to the axis L of the drive shaft 16 and is set at a position beyond the drive shaft 16 on a side facing the hinge mechanism 20 with the axis L interposed therebetween. Accordingly, as shown in FIG. 4, the support portion 19a having an arc shape centered on the axis S is provided on the inner surface of the through hole 19 with the hinge mechanism 20 with the axis L of the drive shaft 16 interposed therebetween. It is provided on the opposite side.

The hinge mechanism 20 will be described in detail. As shown in FIGS. 2 and 5, a pair of guide bins 21 are provided across the top dead center position D on the outer peripheral portion of the front surface of the swash plate 18. I have. The guide pin 21 extends toward the rotary support member 17, and a spherical portion 21a is formed at the tip thereof. The pair of support arms 22 are provided so as to face the guide bin 21 at the outer peripheral portion of the back surface of the rotary support 17. The support arm 22 extends toward the swash plate 18 and has a guide hole 22a formed at the end thereof. The guide hole 22 a extends from the outside toward the axis L of the drive shaft 16 toward the swash plate 18. The guide pin 21 is inserted into the guide hole 22a of the support arm 22 with a spherical portion 21a.

Cylinder pores 1 2a are at predetermined intervals around axis L in cylinder block 12 Are formed (only the-part is shown in the figure). The single-headed piston 23 is housed in each cylinder bore 12a. The piston 23 is moored to the outer periphery of the swash plate 18 via a shoe 24.

The suction chamber 25 is defined at the center of the rear housing 13 內. The discharge chamber 26 is defined on the outer peripheral portion of the housing 13. The suction port 27, the suction valve 28 for opening and closing the suction port 27, the discharge port 29, and the discharge valve 30 for opening and closing the discharge port 29 are formed in the valve forming body 14, respectively.

The swash plate 18 is rotatable with the drive shaft 16 via a rotation support 17 and a hinge mechanism 20. The swing of the swash plate 18 back and forth in the axis L direction due to the rotation of the drive shaft 16 is converted into a reciprocating motion of the piston 23 via the shaft 24. As shown in FIGS. 2 and 3, when the swash plate 18 corresponds to the piston 23 with the top dead center position D, the biston 23 in the figure is located at the top dead center. When the swash plate 18 rotates 180 ° from the state shown in FIGS. 2 and 3, the piston 23 in the figure is located at the bottom dead center.

Therefore, the refrigerant gas in the suction chamber 25 moves from the top dead center side of the biston 23 to the bottom dead center side and is sucked into the cylinder bore 12 a through the suction port 27 and the suction valve 28. . The refrigerant gas flowing into the cylinder bore 12a is compressed by the movement of the piston 23 from the bottom dead center side to the top dead center side, and is discharged through the discharge port 29 and the discharge valve 30. Discharged into chamber 26.

The swash plate 18 has a slide guide relationship between the spherical portion 21 a of the guide bin 21 in the hinge mechanism 20 and the guide hole 22 a of the support arm 22, and is penetrated by the drive shaft 16. By the slide supporting action through the hole 19, the drive shaft 16 can be tilted while sliding in the direction of the axis L with respect to the drive shaft 16. When the center of the radius of the swash plate 18 is slid toward the cylinder block 12, the inclination angle of the swash plate 18 is reduced. The circlip 31 is externally fixed to the drive shaft 16 between the swash plate 18 and the cylinder block 12, and regulates the minimum inclination angle of the swash plate 18. The maximum inclination angle of the swash plate 18 is defined by the contact with the rotating support 17. The tilt-reducing panel 32 is wound around the drive shaft 16 between the rotary support 17 and the swash plate 18, and the center of the radius of the swash plate 18 is a cylinder. Block 1 Energize in 2 directions.

The bleed passage 35 connects the crank chamber 15 and the suction chamber 25. The air supply passage 36 connects the discharge chamber 26 to the crank chamber 15. The capacity control valve 37 is interposed on the air supply passage .36. The displacement control valve 37 is a pressure-sensitive valve, and includes a diaphragm 39 responsive to a pressure change in the pressure-sensitive chamber 38 and a valve body 40 operatively connected to the diaphragm 39. The pressure-sensitive passage 41 connects the suction chamber 25 to the pressure-sensitive chamber 38. The refrigerant gas in the suction chamber 25 is introduced into the pressure-sensitive chamber 38 via the pressure-sensitive passage 41.

Therefore, the diaphragm 39 is sensitive to the suction pressure, and the opening of the air supply passage 36 is adjusted by the operation of the valve body 40 accompanying the suction pressure. As a result, the pressure in the crank chamber 15 is changed, and the difference between the pressure in the crank chamber 15 acting before and after the piston 23 and the pressure in the cylinder bore 12 a is adjusted. Therefore, the inclination angle of the swash plate 18 is changed, the stroke amount of the button 23 is changed, and the discharge capacity is adjusted.

That is, for example, when the cooling load is large, the suction pressure becomes higher than the set value, and the capacity control valve 37 is operated so as to reduce the opening of the air supply passage 36. For this reason, as shown in FIG. 2, the pressure in the crank chamber 15 is released to the suction chamber 25 via the bleed passage 35 and is reduced. Therefore, the spherical portion 21 a of the guide pin 21 in the hinge mechanism 20 is moved in the guide hole 22 a of the support arm 22 in a direction away from the axis L. Further, as shown in FIG. 4, the swash plate 18 makes the support portion 19 a contact the peripheral surface of the drive shaft 16, and moves the swash plate 18 on the drive shaft 16 against the inclination-reducing panel 32. It is slid to the rotating support 17 side and rotated clockwise about the axis S of the support 19a. As a result, the inclination angle of the swash plate 18 is changed to the maximum inclination side, and the stroke amount of the biston 23 increases. As a result, as the discharge capacity increases, the suction pressure decreases so as to approach the set value.

When the cooling load is small, the suction pressure becomes lower than the set value, and the capacity control valve 37 is operated so as to increase the opening degree of the air supply passage 36. Therefore, the pressure of the crank chamber 15 is increased by the introduction of the refrigerant gas from the discharge chamber 26. Therefore, as shown in FIG. 3, the spherical portion 21 a of the guide bin 21 in the hinge mechanism 20 is It is moved in the direction approaching the axis L within the guide hole 2 2 a of No. 2. In addition, as shown by a two-dot chain line in FIG. 4, the swash plate 18 is bent to the inclination reducing panel 32 while the supporting capital 19a is in contact with the peripheral surface of the drive shaft 16 and the swash plate 18 is bent. 6 and slides counterclockwise about the axis S of the support portion 19a. For this reason, the inclination angle of the swash plate 18 is changed to the minimum inclination side, and the stroke amount of the piston 23 is reduced. As a result, as the discharge capacity becomes smaller, the suction pressure is increased so as to approach the set value.

Now, during operation of the compressor, a load K is applied to the piston 23 by the compression of the refrigerant gas, and this compression load K is transmitted through the swash plate 18 and the spherical portion 21a of the guide bin 21. It acts on the inner surface of the guide hole 22 a on the rotating support 17 side. The spherical capital 2la receives a reaction force F of a compressive load K from the guide hole 22a. The guide hole 22 a extends toward the swash plate 18 side so as to approach the axis L of the drive shaft 16 from the outside. Accordingly, the reaction force F acting on the guide bin 21 generates a component force f in the direction of shifting the swash plate 18 toward the top dead center position D with respect to the drive shaft 16.

In addition, the center of gravity of the swash plate 18 is shifted to the top dead center position D side with respect to the axis L mainly due to the uneven distribution of the guide bin 21 with respect to the axis L. The uneven distribution of the guide pins 21 is offset by the counter weights 18a provided on the side of the swash plate 18 facing the guide bins 21 with the axis L interposed therebetween, but in this embodiment, The weight and formation position of the countergate 18a are set so that the rotational balance is slightly unbalanced on the guide bin 21 side. Therefore, the rotating swash plate 18 tends to shift to the top dead center position D side with respect to the drive shaft 16 due to the unbalance of the centrifugal force that increases the guide bin 21 side.

That is, the above-mentioned compression load K becomes smaller as the discharge capacity is adjusted to the minimum side and the compression ratio becomes smaller, and the component force f becomes smaller accordingly. If the component force f becomes small, there is a possibility that the swash plate 18 cannot be held while being shifted toward the top dead center position D with respect to the drive shaft 16. For this reason, the center of gravity of the swash plate 18 is shifted to the top dead center position D side to compensate for the small component force f when the discharge capacity is small. You.

From the above and the like, the inner surface of the through hole 19 of the swash plate 18 is in a state where the support portion 19a is pressed against the peripheral surface of the drive shaft 16 during the operation of the compressor. Therefore, the supporting portion 19a receives an excessive load from the peripheral surface of the drive shaft 16, and slides on the peripheral surface of the drive shaft 16 when the capacity is changed. However, in the present embodiment, the hardness of the support portion 19a is increased by the hardening treatment, and the circumference of the drive shaft 16 is higher than the surface state of the aluminum material forming the swash plate 18 as it is. The durability against pressure contact and sliding with the surface has been improved. Therefore, the supporting portion 19a is hardly deformed by abrasion, and can maintain an arc shape centered on the axis S for a long time.

As the above-described hardening process, a quenching process is performed in the present embodiment. This quenching process is performed by induction hardening. That is, as shown in FIG. 6, the coil 51 is inserted into the through hole 19, and a high-frequency current is supplied from the power supply 52 to the coil 51. When the high-frequency current is supplied to the coil 51, the entire inner surface of the through hole 19 including the support portion 19a is heated by Joule heat due to an overcurrent generated by electromagnetic induction based on the high frequency current. Thus, the inner surface of the through hole 19 is heated for a predetermined time, and then rapidly cooled by a cooling liquid such as oil or water.

The present embodiment having the above configuration has the following effects.

(1) As described above, the hardened support portion 19a has improved durability, and can maintain an arc shape around the axis S for a long time. Accordingly, the swash plate 18 can be tilted about the axis S between the maximum tilt position and the minimum tilt position, and the tilt angle of the swash plate 18 is adjusted to the tilt angle controlled by the displacement control valve 37. Changes can be made reliably and high-precision capacity control can be achieved over a long period of time. This leads to improved compressor reliability.

(2) The hardening treatment of the support portion 19a is a quenching treatment. The quenching process requires only a simple operation of heating and rapidly cooling the supporting portion 19a, and can perform the operation safely compared to a plating process using chemicals.

Here, when a load is applied to the support portion 19a, the shrinkage stress is applied to the inside of the swash plate 18a. Reach. Therefore, even if the hardening treatment is performed only on the support 19 a (the surface of the swash plate 18), the deformation of the inside of the swash plate 18 causes an arc shape centered on the axis S of the support 19 a. There is a risk of collapse. However, the heat applied during the quenching process is applied not only to the support capital 19a but also to the inside of the swash plate 18. Therefore, the hardening treatment can be performed to the inside of the swash plate 18 and the durability of the support portion 19a is further improved.

(3) The quenching process of the support 19a is performed by induction hardening. Induction quenching is easier than quenching with flame quenching. In addition, compared with flame quenching, the swash plate 18 can be hardened deeper inside, and the durability of the support portion 19a is further improved.

(4) The support part 19 η exists in the deep part inside the narrow through hole 19. Applying the curing treatment locally only to the support portion 19a in such an environment is a troublesome operation that requires accuracy to reliably aim at the support portion 19a. However, as described above, the hardening process is performed on the entire surface of the through hole 19, and as a result, the hardening process is performed on the support portion 19a. Therefore, the hardening process can be easily and reliably applied to the support portion 19a. In addition, the hardness of the part other than the support part 19a is increased by the hardening treatment, and the through-hole 19, which may be in pressure contact with the drive shaft 16 due to rattling of the swash plate 18, etc. The durability of the entire inner surface is improved.

The present invention can be implemented in the following modes without departing from the spirit of the present invention.

〇 In addition to induction hardening, the above quenching treatment includes carburizing quenching and flame quenching.

硬化 Change the hardening process for the support 19 a to the plating process. Examples of the plating include Nikke / Revolon plating.

硬化 Change the hardening treatment for the support 19 a to the nitrification treatment. Examples of the nitriding treatment include an ion nitriding treatment, a gas softening treatment, and a tough tride treatment.

硬化 Other hardening treatments include diamond like carbon (DLC) and titanium nitride coating. 〇 Apply curing treatment only to the support 19 a.

(4) A hardening treatment is applied to the entire surface of the swash plate 18 so that the supporting portion 19a is hardened as a result. This makes it possible to easily and reliably apply the curing treatment to the support 19a.

〇The swash plate 18 should be made of iron-based material. By doing so, the durability of the support portion 19a is further improved.

The technical idea that can be grasped from the above embodiment will be described.

(1) The variable displacement compressor according to claim 1, wherein the curing process is a plating process. By doing so, the durability of the support portion 19a is improved.

(2) The variable displacement compressor according to claim 1, wherein the curing treatment is a nitrification treatment. By doing so, the durability of the support portion 19a is improved.

(3) The variable displacement compressor according to any one of claims 1 to 3, wherein the hardening treatment is performed on a surface of the through hole 19 other than the support portion 19a. .

In this way, the durability can be improved by curing treatment in other places than the support capital 19a.

Claims

The scope of the claims

1. A rotary support is fixed to the drive shaft, a cam plate is supported on the drive shaft through a through hole, a piston is connected to the cam plate, and there is a gap between the rotary support and the cam plate. A hinge mechanism is interposed, the cam plate is rotatable integrally with the drive shaft via the rotation support and the hinge mechanism, and converts the rotation of the drive shaft into forward / backward movement of the piston. By the guide of the hinge mechanism and the slide support action through the through hole by the drive shaft, it can be tilted while sliding on the drive shaft, and the stroke of the piston is changed by changing the inclination angle of the cam plate to discharge. In the variable displacement compressor with the capacity to be adjusted,

On the inner surface of the through hole in the cam plate, an arc-shaped support is formed on the inner surface of the through-hole, which is in contact with the drive shaft and receives a slide support action by the drive shaft. A variable displacement compressor that is set beyond the drive shaft on the side facing the hinge mechanism with the pinch in between and forms the center of tilt of the cam plate, and the support is hardened.

2. The variable displacement compressor according to claim 1, wherein the hardening process is a quenching process.

3. The variable displacement compressor according to claim 2, wherein the quenching is performed by low-frequency quenching.

4. The variable displacement compressor according to any one of claims 1 to 3, wherein the hardening treatment is performed on substantially the entire inner surface of the through hole.

5. The variable displacement compressor according to any one of claims 1 to 4, wherein the cam plate is made of aluminum.