KR20000070849A - Variable displacement compressor - Google Patents

Abstract

The swash plate 18 is rotatable integrally with the drive shaft 16 through the rotary support 17 and the hinge mechanism 20, and converts the rotation of the drive shaft 16 into a reciprocating motion of the piston 23.

The swash plate 18 is capable of inclined movement while sliding on the drive shaft 16 by a guide of the hinge mechanism 20 and a sliding support action through the through hole 19 by the drive shaft 16. By changing the inclination angle, the stroke of the piston 23 is changed to adjust the discharge capacity.

The swash plate 18 receives the sliding action by the drive shaft 16 because the arc-shaped support portion 19a abuts against the drive shaft 16.

The axis S, which is the center of the circular arc of the supporting portion 19a, is set beyond the drive shaft 16 on the side opposite the hinge mechanism 20 with the axis L of the drive shaft 16, so that the swash plate 18 It forms the center of the tilt movement.

The support portion 19a has a high hardness due to high frequency hardening, thereby improving durability against pressure contact with the circumferential surface of the drive shaft 16 and sliding movement.

Description

Variable displacement compressors {VARIABLE DISPLACEMENT COMPRESSOR}

As a compressor of this kind, for example, there is one disclosed in Japanese Patent Laid-Open No. 7-91366 proposed by the present applicant.

That is, as shown in FIG. 7, the drive shaft 102 is supported by the housing 101 so that rotation is possible.

The rotary support 103 is fixed to the drive shaft 102.

In the swash plate 104 as the cam plate, a through hole 105 is penetrated through a central portion thereof, and a drive shaft 102 is fitted into the through hole 105.

The piston 106 is accommodated in the cylinder bore 101a provided in the housing 101 and moored to the swash plate 104 via the shoe 108.

The hinge mechanism 109 is interposed between the rotary support 103 and the swash plate 104.

That is, the guide pin 110 is provided near the top dead center position D of the swash plate 104.

A spherical portion 110a is formed at the tip of the guide pin 110.

Support arm 111 is provided on the rotary support 103 facing the guide pin 110.

The guide hole 111a is formed in the support arm 111.

The guide pin 110 is inserted into the guide hole 111a of the support arm 111 by its spherical portion 110a.

The supporting portion 105a is provided on the inner surface of the through hole 105 on the side facing the hinge mechanism 109 along the axis L of the drive shaft 102.

The support part 105a forms an arc shape centering on the axis line S. FIG.

The swash plate 104 is integrated with the drive shaft 102 through the rotary support 103 and the hinge mechanism 109 to be rotatable.

The forward and backward swing in the direction of the axis L of the swash plate 104 due to the rotation of the drive shaft 102 is converted into a reciprocating motion of the piston 106 through the shoe 108, and the refrigerant gas is compressed in the cylinder bore 101a. This is done.

The swash plate 104 is axially driven by the sliding guide relationship between the spherical portion 110a and the guide hole 111a in the hinge mechanism 109 and the sliding support action through the through hole 105 by the drive shaft 102. The inclined movement is possible while sliding in the (L) direction.

When the inclination angle of the swash plate 104 is changed, the stroke of the piston 106 is changed to adjust the discharge capacity.

Here, during operation of the compressor, a load K is applied to the piston 106 by the compression of the refrigerant gas, and this compression load K is a spherical portion of the swash plate 104 and the guide pin 110. It acts on the inner surface of the rotation support body 103 side of the guide hole 111a via 110a.

The guide pin 110 receives the reaction force F of this compression load K from the guide hole 111a.

The guide hole 111a is extended toward the swash plate 104 side so as to approach from the outside with respect to the axis L of the drive shaft 102.

Accordingly, the reaction force F acting on the guide pin 110 causes the component force f in the direction in which the swash plate 104 is shifted toward the top dead center position D with respect to the drive shaft 102.

Due to such a relationship, the swash plate 104 is in a state where the support portion 105a of the through hole 105 is pressed against the circumferential surface of the drive shaft 102 during the operation of the compressor.

When changing the capacity of the compressor, the swash plate 104 is inclined while sliding the upper portion of the drive shaft 102 while the support portion 105a is pressed against the circumferential surface of the drive shaft 102.

That is, the inclination movement of the swash plate 104 is performed centering on the arc-shaped center axis S of the support part 105a.

In other words, the swash plate 104 is inclined about the axis S set beyond the drive shaft 102 on the side facing the hinge mechanism 109 along the axis L. As shown in FIG.

In the technique of Japanese Patent Laid-Open No. 7-91366 having the above-described configuration, support and guidance of the swash plate 104 by the drive shaft 102 are directly performed through the support portion 105a of the through hole 105.

Therefore, the effect is described as follows in the "effect of invention" column, for example.

Like the conventional technique described in Japanese Patent Laid-Open Publication No. 4-159464, there is a sleeve between the swash plate and the drive shaft (exposed to be slidable on the drive shaft) and a slit plate that protrudes from the sleeve to allow tilting motion. Since it is not necessary to install the center shaft pin, the number of parts can be reduced.

Thus, the manufacturing cost can be reduced and the parts can be easily managed.

By the way, in the technique of Japanese Patent Laid-Open No. 7-91366, the support portion 105a is pressed against the circumferential surface of the drive shaft 102 during the operation of the compressor and is subjected to an excessive load, and further, the support portion during the capacity change. 105a becomes a sliding motion with the circumferential surface of the drive shaft 102.

Therefore, the support part 105 is easy to deform | wear, and was unable to maintain the circular arc shape centering on the axis S for a long time.

As a result, the center of the inclination movement is shifted from the axis S, and the swash plate 104 may be adjusted to an inclination angle different from the desired inclination angle, and the capacity control cannot be precisely performed.

Recently, in order to reduce the weight of the compressor, it has been proposed to configure the swash plate 104 made of an aluminum material.

However, since the swash plate 104 made of an aluminum material has a lower strength than that made of an iron-based material, an improvement in the durability of the support portion 105a is strongly required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a variable displacement compressor having improved durability of a support in a configuration in which support and guide of a cam plate by a drive shaft are directly performed through an inner surface support support of a through hole.

The present invention relates to, for example, a variable displacement compressor which can be applied to a cantilevering system of a vehicle and can adjust the discharge capacity by changing the stroke of the piston by changing the inclination angle of the cam plate.

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 illustrating main parts of FIG. 1 and shows the drive shaft broken. FIG.

3 is an explanatory diagram showing a state where the discharge capacity is minimized.

4 is an enlarged view of a vicinity of a support portion of a through hole in FIG. 1; FIG.

5 is a front view showing the swash plate taken out from FIG.

FIG. 6 is a diagram illustrating high frequency curing performed with respect to a through hole of a swash plate. FIG.

7 is an enlarged sectional view showing main parts of a compressor of JP-A-7-91366.

In the variable displacement compressor of the present invention, an inner surface of the through hole in the cam plate is formed with an arc-shaped support portion which is in contact with the drive shaft and is subjected to sliding support by the drive shaft, and the center portion of the arc-shaped arc of the support portion is hinged along the axis of the drive shaft. On the side facing the mechanism, the inclined motion center of the cam plate set beyond the drive shaft is formed, and the support portion is hardened.

In this configuration, the cam plate is tilted about the axis of the support while sliding the drive shaft by the sliding support action through the guide of the hinge mechanism and the support of the through hole by the drive shaft.

By changing the inclination angle of the cam plate, the stroke of the piston is changed to adjust the discharge capacity.

The support is hardened by the hardening treatment, and the durability against the pressing contact with the drive shaft and the sliding motion is improved.

The hardening treatment is a quenching treatment.

In this structure, the hardness of the support part is raised by hardening hardening treatment.

The quench hardening treatment is performed by an induction hardening treatment.

In this structure, the hardening process is given to the support part by high frequency hardening.

The hardening treatment is carried out almost all of the inner surface of the through hole.

In this configuration, the hardening treatment is performed on the entire inner surface of the through hole, and as a result, the hardening treatment is performed on the supporting portion, which is a simpler and more reliable operation than the hardening treatment only on the supporting portion.

The cam plate is made of aluminum.

In this configuration, for example, the cam plate is lighter in comparison with that of the iron system, and the hardened support is made of, for example, the durability of the aluminum material having a lower strength than that of the iron system. The fall of is prevented.

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. 1 to 6.

As shown in FIG. 1, the front housing 11 is fixed to the front end of the cylinder block 12.

The rear housing 13 is fixed to the rear end of the cylinder block 12 via a valve forming body 14.

The crank chamber 15 is enclosed by the front housing 11 and the cylinder block 12 to form a partition.

The drive shaft 16 is hypothetically rotatable between the front housing 11 and the cylinder block 12 so as to pass through the crank chamber 15.

The drive shaft 16 is connected to the vehicle engine as an external drive source (not shown) via an electromagnetic clutch mechanism.

Therefore, the drive shaft 16 is rotationally driven by the connection of the clutch mechanism in the starting state of the vehicle engine.

The rotary support 17 is fixed to the drive shaft 16 in the crank chamber 15.

The swash plate 18 as the cam plate is made of an aluminum material (including an aluminum alloy) and housed in the crank chamber 15.

The drive shaft 16 is inserted into the through hole 19 penetrated to 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 said through hole 19, a drilling process is first performed along the center line I, and a round hole is formed in the center part of a swash plate workpiece | work.

Then, end mills of substantially the same diameter are inserted into the round holes and rotated in a predetermined angular range about the axis S in the positive and reverse directions while being rotated.

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 the side facing the hinge mechanism 20 with the axis L interposed therebetween.

Therefore, as shown in FIG. 4, the support part 19a which forms the circular arc shape centering on the axis S is hinged by the axis line L of the drive shaft 16 in the inner surface of the through-hole 19. As shown in FIG. It is installed on the side facing (20).

The hinge mechanism 20 will be described in detail. As shown in FIGS. 2 and 5, the pair of guide pins 21 glide on the top dead center position D at the front outer circumference of the swash plate 18. It is installed opposite.

The guide pin 21 extends toward the rotary support 17, and a spherical portion 21a is formed at the tip end thereof.

The pair of support arms 22 protrude so as to face the guide pins 21 at the outer periphery of the rear surface of the rotary support 17.

The support arm 22 extends toward the swash plate 18, and a guide hole 22a penetrates the tip end portion thereof.

The guide hole 22a extends toward the swash plate 18 side from the outside with respect to the axis L of the drive shaft 16.

The guide pin 21 is inserted into the guide hole 22a of the support arm 22 as a spherical portion 21a.

The cylinder bore 12a is formed in plural in the cylinder block 12 at predetermined intervals around the axis L (only one place is shown in the drawing).

The migrating piston 23 is housed in each cylinder bore 12a.

The piston 23 is moored to the outer periphery of the swash plate 18 via the shoe 24.

The suction chamber 25 is partitioned in the center part in the rear housing 13.

The discharge chamber 26 is partitioned in the outer dollet of the rear housing 13.

Suction port 27 The suction valve 28 which opens and closes the suction port 27, the discharge port 29, and the discharge valve 30 which opens and closes the discharge port 29 are formed in the valve body 14, respectively. .

The swash plate 18 is rotatable integrally with the drive shaft 16 through the rotary support 17 and the hinge mechanism 20.

The oscillation of the swash plate 18 in the front and rear directions of the swash plate 18 accompanying the rotation of the drive shaft 16 is converted into a reciprocating motion of the piston 23 via the shoe 24.

As shown in FIG. 2 and FIG. 3, when the swash plate 18 corresponds to the piston 23 at the top dead center position D, the piston 23 in the figure is positioned at the top dead center.

When the swash plate 18 is rotated 180 degrees in the state shown in Figs. 2 and 3, the piston 23 in the drawing is located at the bottom dead center.

Therefore, the refrigerant gas in the suction chamber 25 is sucked into the cylinder bore 12a through the suction port 27 and the suction valve 28 by the movement from the top dead center side to the bottom dead center side of the piston 23.

The refrigerant gas flowing into the cylinder bore 12a is compressed by the movement from the bottom dead center side to the top dead center side of the piston 23 and is discharged to the discharge chamber 26 through the discharge port 29 and the discharge valve 30. do.

The swash plate 18 is formed by the sliding guide relationship between the spherical portion 21a of the guide pin 21 and the guide hole 22a of the support arm 22 in the hinge mechanism 20 and the drive shaft 16. By the sliding support action through the through-hole 19, the inclined movement is possible while slidingly sliding in the direction of the axis L with respect to the drive shaft 16. As shown in FIG.

When the radial center of the swash plate 18 is slid to the cylinder block 12 side, the inclination angle of the swash plate 18 is reduced.

The circlip 31 is fixed to the drive shaft 16 externally between the swash plate 18 and the cylinder block 12, and is defined to abut the minimum inclination angle of the swash plate 18.

The maximum inclination angle of the swash plate 18 is defined by the abutment contact with the rotary support 17.

The inclined angle reducing spring 32 is recommended to the drive shaft 16 between the rotation support 17 and the swash plate 18, and the radial center portion of the swash plate 18 in the direction of the cylinder block 12 is provided. Apply force.

The bleeding passage 35 connects the crank chamber 15 and the suction chamber 25.

The air supply passage 36 connects the discharge chamber 26 and 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 reducing valve, and includes a diaphragm 39 that responds to a pressure change in the pressure reducing chamber 38, and a valve body 40 operatively connected to the diaphragm 39.

The decompression passage 41 connects the suction chamber 25 and the decompression chamber 38.

The refrigerant gas in the suction chamber 25 is introduced into the pressure reduction chamber 38 through the pressure reduction passage 41.

Therefore, the diaphragm 39 is sensitive to the suction pressure, and the opening degree of the air supply passage 36 is adjusted by the operation of the valve body 40 accordingly.

As a result, the pressure of the crank chamber 15 is changed, and the difference between the pressure of the crank chamber 15 acting before and after the piston 23 and the pressure of the cylinder bore 12a is adjusted.

Therefore, the inclination angle of the swash plate 18 is changed, the stroke amount of the piston 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 displacement control valve 37 is operated to reduce the opening degree of the air supply passage 36.

For this reason, as shown in FIG. 2, the pressure of the crank chamber 15 falls to the suction chamber 25 through the bleeding passage 35, and falls.

Therefore, the spherical portion 21a of the guide pin 21 in the hinge mechanism 20 moves in the direction away from the axis L in the guide hole 22a of the support arm 22.

In addition, as shown in FIG. 4, the swash plate 18 resists the inclined angle reducing spring 32 while bringing the support portion 19a into contact with the circumferential surface of the drive shaft 16 and rotates on the drive shaft 16. While sliding to the side, it is rotated clockwise about the axis S of the support part 19a.

As a result, the inclination angle of the swash plate 18 is changed to the maximum inclination angle side, so that the stroke amount of the piston 23 is increased.

As a result, the discharge capacity is increased and the suction pressure is lowered to approach the set value.

If the cooling load is small, the suction pressure is lower than the set value, and the displacement control valve 37 is operated to increase the opening degree of the air supply passage 36.

For this reason, the pressure of the crank chamber 15 rises by introduction of the refrigerant gas from the discharge chamber 26.

Therefore, as shown in FIG. 3, the spherical part 21a of the guide pin 21 in the hinge mechanism 20 is the direction which approaches the axis L within the guide hole 22a of the support arm 22. As shown in FIG. Is moved to.

In addition, in FIG. 4, as shown by the two-point chain line, the swash plate 18 is driven by the force of the inclined angle reducing spring 32 while bringing the support portion 19a into contact with the circumferential surface of the drive shaft 16. 16) is slid to the cylinder block 12 side and rotated counterclockwise around the axis S of the support 19a.

For this reason, the inclination angle of the swash plate 18 is changed to the minimum inclination angle, so that the stroke amount of the piston 23 becomes small.

As a result, the discharge capacity becomes small, so that the suction pressure is raised to approach the set value.

During operation of the compressor, a load K is applied to the piston 23 by the compression of the refrigerant gas, and this compressive load K is carried out through the spherical portion 21a of the swash plate 18 and the guide pin 21. The inner surface of the guide hole 22a on the rotation support 17 side is applied.

The spherical portion 21a receives the reaction force F of the compression load K from the guide hole 22a.

The guide hole 22a extends toward the swash plate 18 side from the outside with respect to the axis L of the drive shaft 16.

Therefore, the reaction force F acting on the guide pin 21 causes the component force f in the direction to shift the swash plate 18 to the top dead center position D side with respect to the drive shaft 16.

Moreover, the swash plate 18 mainly shifts the center to the top dead center position D side with respect to the axis L by the ubiquitous with respect to the axis line L of the guide pin 21. As shown in FIG.

The localization of the guide pin 21 is offset by the counterweight 18a provided on the side facing the guide pin 21 along the axis L in the swash plate 18. However, in the present embodiment, the guide pin 21 is deliberately rotated. The weight and the forming position of the counterweight 18a are set so that the balance is slightly unbalanced on the guide pin 21 side.

Therefore, the rotating swash plate 18 tries to shift to the top dead center position D side with respect to the drive shaft 16 by the imbalance of the centrifugal force by which the guide pin 21 side becomes large.

That is, the compression load K becomes smaller when the discharge capacity is adjusted to the minimum side and the compression ratio becomes smaller, and accordingly the component force f becomes smaller.

If the component force f decreases, there is a possibility that the swash plate 18 cannot be held in a state shifted to the top dead center position D with respect to the drive shaft 16.

For this reason, by shifting the center of the swash plate 18 to the top dead center position D side, it is trying to supplement the small thing of the component force f when discharge volume is small.

As described above, during operation of the compressor, the inner surface of the through hole 19 of the swash plate 18 is in a state in which the supporting portion 19a is in pressure contact with the circumferential surface of the drive shaft 16.

Therefore, the support part 19a is subjected to an excessive load from the circumferential surface of the drive shaft 16, and furthermore, when the capacity is changed, the support 19a is slid with the circumferential surface of the drive shaft 16.

However, in this embodiment, the hardening treatment is performed and the hardness of the support portion 19a is high, and the pressure contact with the circumferential surface of the drive shaft 16 or slippage is performed rather than the surface state of the aluminum material constituting the swash plate 18. The durability to exercise is improved.

Therefore, the support part 19a is hard to be deformed and can maintain the circular arc shape centering on the axis S for a long time.

As said hardening treatment, in this embodiment, quenching is performed.

This quenching treatment is 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 19 is heated by joule heat caused by overcurrent generated by the electromagnetic induction.

In this way, the inner surface of the through hole 19 is heated for a predetermined time, and then quenched with cooling liquid such as oil or water.

In this embodiment of the said structure, the following effects are exhibited.

(1) As mentioned above, the hardened support part 19a improves durability and can maintain the arc shape centering on the axis S for a long time.

Therefore, the swash plate 18 can be tilted about the axis S between the maximum inclination angle position and the minimum inclination angle position, and the capacity control valve 37 tries to control the inclination angle of the swash plate 18. The inclination angle can be changed reliably, and the capacity control can be achieved over a long period of time with a high degree of precision.

This leads to improved reliability of the compressor.

(2) The hardening treatment of the support 19a is a hardening treatment. The quenching treatment may be a simple operation only for heating and quenching the support 19a. Furthermore, the quenching treatment can be safely performed in comparison with the plating treatment using chemicals.

Here, when a load acts on the support part 19a, the stress reaches the inside of the swash plate 18. FIG.

Therefore, even if hardening is performed only on the support part 19a (the surface of the swash plate 18), the arc shape centering on the axis S of the support part 19a may collapse by deformation of the inside of the swash plate 18. There is this.

However, heat applied during the quenching treatment is applied not only to the support portion 19a but also to the inside of the swash plate 18.

Therefore, since hardening process can be performed even inside the swash plate 18, the durability of the support part 19a further improves.

(3) The hardening treatment of the support part 19a is performed by high frequency hardening.

Induction hardening is simpler in comparison with flame hardening in hardening.

Moreover, compared with flame hardening etc., hardening is possible to the depth of the inside of the swash plate 18, and the durability of the support part 19a is further improved.

(4) The support part 19a exists in the recess part in the narrow through-hole 19. As shown in FIG.

Locally hardening only the support 19a, which is such an environmental condition, certainly requires precision aiming at the support 19a, which is cumbersome.

However, as mentioned above, the hardening treatment is performed on the entire inner surface of the through hole 19, and as a result, the hardening treatment is performed on the support portion 19a.

Therefore, hardening treatment can be performed simply and reliably with respect to the support part 19a.

In addition, the parts other than the support 19a are also hardened to increase the hardness, and the durability of the entire inner surface of the through-hole 19, which is likely to come into pressure contact with the drive shaft 16 due to the shaking of the swash plate 18, is increased. Is improved.

Moreover, it can also be implemented in the following form within the range which does not deviate from the meaning of this invention.

The hardening treatment mentioned above may include carburizing, flame hardening, etc. in addition to high frequency hardening.

○ Change the hardening treatment for the support 19a to plating treatment. As plating, nickel-boron plating is mentioned, for example.

To change the hardening treatment for the support 19a to nitriding.

Examples of the nitriding treatment include ion nitriding, gas nitrocarburizing, tuftride hardening, and the like.

○ As hardening treatment of that excepting the above, diamond-like-carbon (DLC), titanium nitride coating, etc. are mentioned.

○ Carry out hardening only on the support part 19a.

○ A hardening process is performed to the whole surface of the swash plate 18, and as a result, hardening process is performed to the support part 19a. By doing in this way, hardening process can be performed simply and reliably with respect to the support part 19a.

○ Constructing the swash plate 18 with an iron-based material. In this way, the durability of the support 19a is further improved.

The technical thought grasped | ascertained from said embodiment is described.

(1) The variable displacement compressor according to claim 1, wherein the curing treatment is plating treatment. In this way, the durability of the support part 19a is improved.

(2) The variable displacement compressor according to claim 1, wherein the curing treatment is nitriding treatment. In this way, the durability of the support part 19a is improved.

(3) The variable displacement compressor according to any one of claims 1 to 3, wherein the above hardening treatment is carried out on the inner surface of the through hole 19 in addition to the support portion 19a.

By doing so, durability other than the support part 19a is improved by hardening.

Claims (5)

The rotation support is fixed to the drive shaft, the cam plate is supported through the through hole on the drive shaft, the piston is connected to the cam plate, the hinge mechanism is interposed between the rotation support and the cam plate, and the cam plate is the rotation support and It can be rotated integrally with the drive shaft through the hinge mechanism, and the rotation of the drive shaft is converted into reciprocating motion of the piston, and the cam plate is guided on the drive shaft by the sliding support action through the through hole by the guide and the drive shaft of the hinge mechanism. In the variable displacement compressor of the configuration which is capable of inclined movement while sliding, and adjusting the discharge capacity by changing the stroke of the piston by changing the inclination angle of the cam plate, In the cam plate, an inner surface of the through hole is formed with an arc-shaped support portion which abuts against the drive shaft and is subjected to sliding support by the drive shaft. The arc-shaped center axis of the support portion is set beyond the drive shaft on the side facing the hinge mechanism along the axis of the drive shaft to form the center of the tilting motion of the cam plate, A variable displacement compressor comprising a hardening treatment on the support portion. The method of claim 1, The hardening treatment is a variable displacement compressor characterized in that the hardening treatment. The method of claim 2, The quench hardening treatment is a variable displacement compressor characterized in that the high-frequency curing. The method according to any one of claims 1 to 3, The above-mentioned hardening treatment is performed almost entirely on the inner surface of the through hole. The method according to any one of claims 1 to 4, The cam plate is a variable displacement compressor, characterized in that the aluminum material.