JP3503179B2 - Clutchless one-sided piston type variable displacement compressor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mounts a rotary support on a rotary shaft in a housing that accommodates a single-headed piston in a cylinder bore for reciprocating linear movement, and supports the swash plate on the rotary support so as to be tiltable. Then, the tilt angle of the swash plate is controlled according to the difference between the pressure in the crank chamber and the suction pressure through the single-headed piston, and the pressure in the discharge pressure region is supplied to the crank chamber and the pressure in the crank chamber is controlled in the suction pressure region. The present invention relates to a clutchless one-side piston type variable displacement compressor that discharges and regulates pressure in a crank chamber.

[0002]

2. Description of the Related Art In a variable displacement type swash plate compressor disclosed in Japanese Patent Laid-Open No. 3-37378, an electromagnetic clutch for connecting and disconnecting power transmission between an external drive source and a rotary shaft of the compressor. Not using. If the electromagnetic clutch is eliminated, it is possible to eliminate the drawback of poor feeling in feeling due to the ON / OFF shock, especially in the vehicle-mounted form, and to reduce the weight and cost of the entire compressor.

In such a clutchless compressor, there are problems in the discharge capacity when cooling is not necessary and the generation of frost in the evaporator on the external refrigerant circuit. If cooling is not necessary or if frost may be generated, the circulation of the refrigerant on the external refrigerant circuit may be stopped. In the compressor disclosed in Japanese Patent Laid-Open No. 3-37378, the circulation of refrigerant on the external refrigerant circuit is stopped by stopping the flow of refrigerant gas from the external refrigerant circuit into the suction chamber. The inflow of refrigerant gas from the external refrigerant circuit into the suction chamber is controlled by the demagnetization of the electromagnetic on-off valve.

When the flow of the refrigerant gas from the external refrigerant circuit to the suction chamber in the compressor is stopped, the pressure in the suction chamber is lowered and the capacity control valve sensitive to the pressure in the suction chamber is fully opened. Due to this full opening, the refrigerant gas discharged from the discharge chamber flows into the crank chamber, and the pressure in the crank chamber rises. Further, the suction pressure in the cylinder bore also decreases due to the pressure decrease in the suction chamber. Therefore, the difference between the pressure in the crank chamber and the suction pressure in the cylinder bore becomes large, and the swash plate tilt angle shifts to the minimum tilt angle to minimize the discharge capacity. When the discharge capacity becomes the minimum, the torque in the compressor becomes the minimum, and power loss when cooling is unnecessary can be avoided.

When the flow of the refrigerant gas from the external refrigerant circuit into the suction chamber in the compressor is restarted, the pressure in the suction chamber rises and the capacity control valve sensitive to the pressure in the suction chamber closes. Due to this transition to the closed state, the refrigerant gas is prevented from flowing into the crank chamber from the discharge chamber, and the pressure in the crank chamber decreases. Further, the suction pressure in the cylinder bore also rises due to the rise in the pressure in the suction chamber. Therefore, the difference between the pressure in the crank chamber and the suction pressure in the cylinder bore becomes small, and the swash plate tilt angle shifts to the maximum tilt angle.

[0006]

In the clutchless one-sided piston type variable displacement compressor, the difference between the maximum value and the minimum value of the load torque is large, so that the engine stall in the vehicle equipped with the clutchless one-sided piston type variable displacement compressor is large. It becomes a problem. The cause of the engine stall is not only the load torque of the compressor but also the load torque for operating the auxiliary machines such as the alternator and the oil pump for the power steering mechanism. Therefore, the idle-speed controller is used. The idle-speed-controller auxiliary adjusts the air supply amount to the engine during idling in order to control the rotational speed during idling to a target value. The target value when there is load torque on the engine such as the compressor is set higher than the idling speed when there is no load torque on the engine such as the compressor. The engine stall is avoided by increasing the idle speed in this way.

The idle-speed controller performs feedback control for sampling the engine speed and bringing the engine speed closer to a target value. Therefore, if the load torque on the engine at the time of idling increases rapidly, the feedback control of the idle-speed controller cannot follow and there is a risk of engine stall. In the clutchless one-sided piston type variable displacement compressor disclosed in Japanese Patent Laid-Open No. 3-37378, no measures have been suggested for avoiding engine stall due to an increase in load torque in the compressor.

It is an object of the present invention to prevent an engine stall by suppressing a rapid change in load torque during idling in a clutchless one-sided piston type variable displacement compressor.

[0009]

Therefore, according to the present invention,
A rotary support is fixedly attached to a rotary shaft in a housing that accommodates a single-headed piston in a cylinder bore so that the piston can reciprocate linearly, and a swash plate is tiltably supported on the rotary support so that the pressure in the crank chamber and suction pressure are A clutch that controls the tilt angle of the swash plate according to the difference via the single-headed piston, supplies the pressure in the discharge pressure region to the crank chamber, and releases the pressure in the crank chamber to the suction pressure region to regulate the pressure in the crank chamber. In the invention according to claim 1, which is intended for a one-sided piston type variable displacement compressor, a minimum tilt angle defining means for defining a minimum tilt angle of a swash plate,
A compression provided with a refrigerant circulation blocking means for stopping the refrigerant circulation in the external refrigerant circuit in the minimum capacity state, and a throttle body arranged so as to advance and retreat on the pressure release passage for releasing the pressure in the crank chamber to the suction pressure region. In a part of the intermediate tilt angle range between the maximum tilt angle and the minimum tilt angle of the swash plate, at least a part of the tilt of the swash plate is configured so that the passage cross-sectional area of the pressure release passage is narrowed by the throttle body. By interlocking the throttle body, the passage cross-sectional area of the pressure relief passage when the swash plate is in the intermediate inclination range is smaller than the passage cross-sectional area of the pressure relief passage when the swash plate is in the maximum inclination state. I chose

According to the second aspect of the present invention, the throttle body is switchably arranged between a closed position where the refrigerant gas cannot be introduced and an open position where the refrigerant gas can be introduced from the external refrigerant circuit to the suction pressure region,
The refrigerant circulation blocking unit is configured such that the throttle body is interlocked with the tilting movement of the swash plate, and the throttle body is in the closed position when the swash plate has the minimum tilt angle.

According to a third aspect of the present invention, the pressure relief passage is branched into a first branch passage and a second branch passage, and when the swash plate is at the maximum inclination angle, the throttle body is provided with the second branch passage. Is located in a position where the swash plate is in the intermediate tilt angle range, the throttle body is located in a position that closes the second branch passage, and the first branch passage is always open.

According to a fourth aspect of the invention, the passage disconnection of the pressure release passage when the swash plate is in the intermediate inclination range is larger than the passage cross-sectional area of the pressure release passage when the swash plate is in the minimum inclination state. The area is reduced.

According to a fifth aspect of the present invention, the pressure relief passage is branched into a first branch passage, a second branch passage, and a third branch passage, and when the swash plate is at the maximum inclination angle, the throttle body is A position where the second branch passage is opened and a third branch passage is closed, and when the swash plate is in the intermediate tilt angle range, the throttle body closes the second branch passage and the third branch passage. When the swash plate is at the minimum inclination angle, the throttle body is arranged to close the second branch passage and open the third branch passage so that the first branch passage is always open. did.

According to the sixth aspect of the invention, the first branch passage of the pressure release passage passes through the throttle body. In the invention according to claim 7, a connection passage is provided in the throttle body, and when the swash plate is at the maximum inclination angle, the connection passage and the second passage are formed.
The throttle body is arranged at a position where it is connected to the branch passage, and the throttle body is arranged at a position where the connection passage is not connected to the second branch passage and the third branch passage when the swash plate is in the intermediate tilt angle range, When the swash plate is at the minimum inclination angle, the throttle body is arranged at the position where the connection passage and the third branch passage are connected.

[0015]

Even when the swash plate is in the minimum inclination state, the refrigerant gas in the crank chamber flows into the suction pressure region through the pressure release passage, and when the refrigerant gas supply from the discharge pressure region to the crank chamber is stopped. , The pressure in the crank chamber drops. Due to this pressure decrease, the swash plate shifts from the minimum tilt angle to the maximum tilt angle. When the swash plate is in the intermediate tilt angle range between the maximum tilt angle and the minimum tilt angle, the throttle body throttles the pressure release passage, and due to this throttle action, the pressure drop in the crank chamber is slow in the intermediate tilt angle range. is there. Therefore, the inclination angle of the swash plate slowly changes from the minimum inclination angle to the maximum inclination angle, and the increase of the load torque in the compressor at the time of increasing the inclination angle of the swash plate is slow. Therefore, idle-
Speed-The engine stall does not occur because the speed control during idling of the controller is in time.

When the inclination angle of the swash plate approaches the maximum inclination angle, the passage cross-sectional area of the pressure release passage increases, and the maximum inclination angle state of the swash plate is stably maintained. According to the second aspect of the invention, the throttle body gradually narrows the passage cross-sectional area of the refrigerant gas flowing from the external refrigerant circuit to the suction pressure region as the swash plate moves to the side of the minimum tilt angle due to the pressure increase in the crank chamber. This throttling action alleviates the decrease in the refrigerant gas inflow amount from the external refrigerant circuit to the suction pressure region, and the refrigerant gas suction amount from the suction pressure region into the cylinder bore gradually decreases. Therefore, the discharge capacity does not suddenly fluctuate to the minimum capacity side, and the torque in the compressor when the refrigerant circulation is blocked does not fluctuate rapidly in a short time. As the swash plate tilt angle increases from the minimum tilt angle due to the pressure drop in the crank chamber, the throttle body separates in conjunction with the tilt of the swash plate. With this separation, the cross-sectional area of passage of the refrigerant gas from the external refrigerant circuit to the suction pressure region gradually increases. This gradual expansion of the passage cross-sectional area moderates the increase in the refrigerant gas inflow amount from the external refrigerant circuit to the suction pressure region, and the refrigerant gas suction amount from the suction pressure region into the cylinder bore gradually increases. Therefore, the discharge capacity does not suddenly fluctuate to the maximum capacity side, and the torque in the compressor does not fluctuate rapidly in a short time when the refrigerant circulation block is released. The suppression of abrupt torque fluctuations in the compressor eliminates the ON-OFF shock, which is the main purpose of the clutchless compressor.

According to the third aspect of the present invention, the first branch passage is always open even when the swash plate is in the minimum inclination state. Therefore, even in the minimum inclination state in which the refrigerant gas is prevented from flowing from the external refrigerant circuit to the suction pressure area, the refrigerant gas in the compressor circulates in the cylinder bore, the discharge pressure area, the crank chamber, and the suction pressure area, and flows with the refrigerant gas. Lubricating oil lubricates the inside of the compressor.

In the inventions according to claims 4, 5, and 7, when the swash plate shifts from the intermediate tilt angle range to the minimum tilt angle, the passage cross-sectional area of the pressure release passage increases. Therefore, the lubrication in the compressor is favorably performed in the minimum inclination state in which the refrigerant gas is prevented from flowing into the suction pressure region from the external refrigerant circuit.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment embodying the present invention will now be described with reference to FIG.
~ It demonstrates based on FIG. As shown in FIG. 1, a front housing 2 is joined to the front end of a cylinder block 1 which is a part of the housing of the entire compressor. A rear housing 3 is joined and fixed to the rear end of the cylinder block 1 via a valve plate 4, valve forming plates 5A and 5B, and a retainer forming plate 6. A rotary shaft 9 is rotatably supported between the front housing 2 that forms a part of the housing and forms the crank chamber 2a, and the cylinder block 1. The front end of the rotary shaft 9 is the crank chamber 2
It projects from a to the outside, and the driven pulley 10 is fixed to the projecting end. The driven pulley 10 is a belt 11
Is operatively connected to the vehicle engine via. The driven pulley 10 is supported by the front housing 2 via an angular bearing 7. The front housing 2 receives both the load in the thrust direction and the load in the radial direction acting on the driven pulley 10 via the angular bearing 7.

The front end of the rotary shaft 9 and the front housing 2
A lip seal 12 is interposed between and. The lip seal 12 prevents pressure leakage in the crank chamber 2a.
A rotary support 8 is fixed to the rotary shaft 9, and a swash plate 15 is supported so as to be slidable and tiltable in the axial direction of the rotary shaft 9. As shown in FIG. 2, connecting pieces 16 and 17 are fixed to the swash plate 15. A pair of guide pins 18, 19 are fixedly attached to the connecting pieces 16, 17. Guide balls 18a, 19a are provided at the tips of the guide pins 18, 19.
Are formed. A support arm 8a is provided on the rotary support 8 in a protruding manner, and the support arm 8a has a pair of guide holes 8a.
b and 8c are formed. The guide balls 18a and 19a of the guide pins 18 and 19 are slidably fitted in the guide holes 8b and 8c. The swash plate 15 can be tilted in the axial direction of the rotary shaft 9 and can rotate integrally with the rotary shaft 9 by the cooperation of the support arm 8a and the pair of guide pins 18 and 19. The tilt of the swash plate 15 is caused by the support arm 8a and the guide pin 1.
It is guided by the slide guide relationship with 8 and 19, and the slide support action of the rotating shaft 9.

As shown in FIGS. 1, 4 and 5, a housing hole 13 is provided in the center of the cylinder block 1 so as to penetrate in the axial direction of the rotary shaft 9, and a cylindrical diaphragm is provided in the housing hole 13. Body 2
1 is slidably accommodated. The throttle body 21 includes a large diameter portion 21a and a small diameter portion 21b, and a suction passage opening spring 24 is interposed between the step portion between the large diameter portion 21a and the small diameter portion 21b and the inner surface of the accommodation hole 13. The suction passage opening spring 24 urges the throttle body 21 toward the swash plate 15 side.

The rear end of the rotary shaft 9 is inserted in the cylinder of the throttle body 21. A deep groove ball bearing member 25 is interposed between the rear end of the rotary shaft 9 and the inner peripheral surface of the large diameter portion 21a. The rear end of the rotary shaft 9 is supported by the inner peripheral surface of the accommodation hole 13 via the deep groove ball bearing member 25 and the throttle body 21. The outer ring 25a of the deep groove ball bearing member 25 is fixed to the inner peripheral surface of the large diameter portion 21a, and the inner ring 25b is slidable on the peripheral surface of the rotating shaft 9. As shown in FIG. 5, a step portion 9a is formed on the peripheral surface of the rear end of the rotary shaft 9, and the inner ring 25b is restricted from moving toward the swash plate 15 side by the step portion 9a. That is, the deep groove ball bearing member 25 is provided with the swash plate 15 by the step portion 9a.
It is prevented from moving to the side. Therefore, the deep groove ball bearing member 2
The diaphragm body 21 is prevented from moving toward the swash plate 15 side by the contact of the step 5 with the step portion 9a.

In the center of the rear housing 3, the suction passage 2 is provided.
6 is formed. The suction passage 26 communicates with the accommodation hole 13, and a positioning surface 27 is formed around the opening of the suction passage 26 on the accommodation hole 13 side. The tip of the small diameter portion 21b of the throttle body 21 can contact the positioning surface 27. When the tip of the small diameter portion 21b contacts the positioning surface 27, the throttle body 21 is restricted from moving in a direction away from the swash plate 15, and the communication between the suction passage 26 and the accommodation hole 13 is blocked.

A transmission cylinder 28 is slidably disposed on the rotary shaft 9 between the swash plate 15 and the deep groove ball bearing member 25. One end of the transmission cylinder 28 can contact the swash plate 15,
The other end of the transmission cylinder 28 is the outer ring 25a of the deep groove ball bearing member 25.
It is possible to abut only on the inner ring 25b without abutting on.

As the swash plate 15 moves toward the throttle body 21, the swash plate 15 contacts the transmission cylinder 28 and presses the transmission cylinder 28 against the inner ring 25b of the deep groove ball bearing member 25. The deep groove ball bearing member 25 receives a load not only in the radial direction of the rotating shaft 9 but also in the thrust direction. Therefore, the throttle body 21 is biased toward the positioning surface 27 side against the spring force of the suction passage opening spring 24 by the pressing action of the transmission cylinder 28, and the small diameter portion 21b.
The tip of the abuts on the positioning surface 27. Therefore, the swash plate 15
The minimum inclination angle is regulated by the contact between the tip of the small diameter portion 21b of the diaphragm 21 and the positioning surface 27. That is, the diaphragm 2
1, the deep groove ball bearing member 25, the positioning surface 27 and the transmission cylinder 28 constitute the minimum tilt angle defining means.

The minimum inclination angle of the swash plate 15 is slightly larger than 0 °. This minimum inclination state is brought about when the throttle body 21 is arranged in the closed position that blocks the communication between the suction passage 26 and the accommodation hole 13, and the throttle body 21 is in the closed position and the open position separated from this position. The switching arrangement is interlocked with the swash plate 15.

The maximum inclination of the swash plate 15 is regulated by the contact between the inclination regulating projection 8b of the rotary support 8 and the swash plate 15.
A single-headed piston 22 is housed in a cylinder bore 1a penetrating the cylinder block 1 so as to be connected to the crank chamber 2a. A pair of shoes 23 is fitted in the neck portion of the one-headed piston 22. The peripheral edge of the swash plate 15 enters between the shoes 23, and both shoes 23 are provided on both sides of the swash plate 15.
The end faces of are in contact. Therefore, the rotational movement of the swash plate 15 is converted into the forward and backward reciprocating swing of the single-headed piston 22 via the shoe 23, and the single-headed piston 22 moves back and forth in the cylinder bore 1a.

As shown in FIGS. 1 and 3, the rear housing 3 has a suction chamber 3a and a discharge chamber 3b defined therein. An intake port 4a and a discharge port 4b are formed on the valve plate 4. A suction valve 5a is formed on the valve forming plate 5A, and a discharge valve 5b is formed on the valve forming plate 5B. The refrigerant gas in the suction chamber 3a is sucked into the suction port 4a by the returning movement of the single-headed piston 22.
The suction valve 5a is pushed away from the inside to flow into the cylinder bore 1a. The refrigerant gas flowing into the cylinder bore 1a is discharged from the discharge port 4b to the discharge chamber 3b by pushing the discharge valve 5b away from the discharge port 4b by the forward movement of the single-headed piston 22. Discharge valve 5b
Is brought into contact with the retainer 6a on the retainer forming plate 6 to regulate the opening.

A thrust bearing 29 is interposed between the rotary support 8 and the front housing 2. The thrust bearing 29 receives the compression reaction force acting on the rotary support 8 from the cylinder bore 1 a via the single-headed piston 22, the shoe 23, the swash plate 15, the connecting pieces 16 and 17, and the guide pins 18 and 19.

The suction chamber 3a has a housing hole 13 through a through hole 4c.
Is in communication with. When the throttle body 21 is arranged in the closed position, the passage 4c is blocked from the suction passage 26. The suction passage 26 is an inlet for introducing refrigerant gas into the compressor, and the position where the throttle body 21 is blocked on the passage from the suction passage 26 to the suction chamber 3a is on the downstream side of the suction passage 26.

A passage 30 is formed in the rotary shaft 9. The inlet 30a of the passage 30 is opened to the crank chamber 2a near the lip seal 12, and the outlet 30b of the passage 30 is opened to the cylinder of the throttle body 21. 1, 4, and 5
As shown in FIG. 4, a pressure release port 21c is formed through the tip of the throttle body 21, and a connection passage 21d is formed on the peripheral surface of the large diameter portion 21a of the throttle body 21. As shown in FIGS. 1 and 5, when the swash plate tilt angle is the maximum tilt angle, the pressure release port 21c communicates the accommodation hole 13 with the inside of the throttle body 21. As shown in FIGS. 4 and 6, when the swash plate inclination angle is on the minimum inclination side, the pressure release passage 21c communicates the inside of the cylinder of the throttle body 21 with the passage 4c. That is, the pressure release port 21c is always a first branch passage that connects the crank chamber 2a and the suction chamber 3a.

A passage 14 is formed in the cylinder block 1. The inlet 14a of the passage 14 is opened to the inner peripheral surface of the accommodation hole 13, and the outlet of the passage 14 is opened to the suction chamber 3a. As shown in FIGS. 1 and 5, when the swash plate tilt angle is the maximum tilt angle, the connection passage 21d on the throttle body 21 is connected to the inlet 14a of the passage 14. In the tilt range in which the swash plate 15 reaches the minimum tilt angle from the intermediate tilt position shown by the chain line in FIG.
1d disconnects from the connection with inlet 14a. When the swash plate 15 is in the vicinity of the maximum inclination angle, the crank chamber 2a has a pressure release port 2
It communicates with the suction chamber 3a via a first branch passage 1c, and also communicates with the suction chamber 3a via a second branch passage 21a and a passage 14. The swash plate 15 is shown in FIG.
In the tilt range from the intermediate tilt position indicated by the chain line to the minimum tilt angle, the crank chamber 2a communicates with the suction chamber 3a only via the first branch passage that is the pressure release port 21c. That is, the passage cross-sectional area of the pressure release passage that connects the crank chamber 2a and the suction chamber 3a changes according to the tilt angle of the swash plate.

As shown in FIGS. 1 and 4, the discharge chamber 3b and the crank chamber 2a are connected by a pressure supply passage 31.
An electromagnetic opening / closing valve 32 is provided on the pressure supply passage 31. The valve body 34 closes the valve hole 32a by exciting the solenoid 33 of the electromagnetic opening / closing valve 32. When the solenoid 33 is demagnetized, the valve element 34 opens the valve hole 32a. That is, the electromagnetic opening / closing valve 32 opens / closes the pressure supply passage 31 that connects the discharge chamber 3b and the crank chamber 2a.

The passage cross-sectional area S _{1 at the} pressure release passage 21c is smaller than the passage cross-sectional area S _{2 at} the inlet 14a of the passage 14. Passage cross-section area S, which is the passage cross-section area in the passage 14.
₂ is smaller than the cross-sectional area of passage in the passage 30. The passage cross-sectional area (S ₁ + S ₂ ) is set so as to stably maintain the swash plate inclination maximum state, and the passage cross-section S ₁ stabilizes the swash plate minimum inclination when the pressure supply passage 31 is opened. Are set to hold. Curve E ₁ of the graph of FIG.
Shows the change of the passage cross-sectional area of the pressure relief passage according to the inclination angle of the swash plate.

A suction passage 26 for introducing the refrigerant gas into the suction chamber 3a and a discharge port 1b for discharging the refrigerant gas from the discharge chamber 3b.
And are connected by an external refrigerant circuit 35. A condenser 36, an expansion valve 37 and an evaporator 38 are provided on the external refrigerant circuit 35. The expansion valve 37 controls the refrigerant flow rate according to the fluctuation of the gas pressure on the outlet side of the evaporator 38. A temperature sensor 39 is installed near the evaporator 38. Temperature sensor 3
9 detects the temperature in the evaporator 38, and the detected temperature information is sent to the control computer C.

The solenoid 33 of the electromagnetic opening / closing valve 32 is subjected to the excitation / demagnetization control of the control computer C. The control computer C controls the demagnetization of the solenoid 33 based on the detected temperature information obtained from the temperature sensor 39. The control computer C commands the demagnetization of the solenoid 33 when the detected temperature becomes equal to or lower than the set temperature under the ON state of the air conditioner operation switch 40. The temperature below the set temperature reflects the situation in which frost is likely to occur in the evaporator 38.

The control computer C includes an air conditioner operation switch 40 and a rotation speed detector 41 for detecting the engine rotation speed.
Are connected. The control computer C energizes the solenoid 33 based on the specific rotation speed fluctuation detection information from the rotation speed detector 41 when the air conditioner operation switch 40 is ON. Further, the control computer C demagnetizes the solenoid 33 by turning off the air conditioner operation switch 40.

That is, the detected temperature information below the set temperature by the temperature sensor 39, the OFF signal of the air conditioner operation switch 40, and the specific rotation speed fluctuation detection information of the rotation speed detector 41 are:
It becomes a command signal for opening the pressure supply passage 31.

As shown in FIGS. 1 and 4, the rotation speed detector 4
1 is an idle-speed-controller 42 (hereinafter, I
SC42). The ISC 42 performs feedback control for converging the idling speed to a target value based on the rotational speed detection information from the rotational speed detector 41. This control is a duty ratio control for an actuator (not shown) that adjusts the amount of air supplied to the engine.

In the state shown in FIGS. 1 and 5, the solenoid 33 is in the excited state and the pressure supply passage 31 is closed.
Therefore, the high pressure refrigerant gas is not supplied from the discharge chamber 3b to the crank chamber 2a. In this state, the refrigerant gas in the crank chamber 2a simply flows out to the suction chamber 3a through the passage 30, and the pressure in the crank chamber 2a approaches the low pressure in the suction chamber 3a, that is, the suction pressure. Therefore, swash plate 1
The tilt angle of 5 is maintained at the maximum tilt angle, and the discharge capacity is maximized. Since the refrigerant gas in the crank chamber 2a passes through the inlet 30a near the lip seal 12, the lubricating oil flowing with this refrigerant gas enhances lubrication and sealing between the lip seal 12 and the rotating shaft 9.

When the swash plate 15 maintains the maximum inclination angle and the discharge action is performed in a state where the cooling load is small, the evaporator 38 is
The temperature at is decreasing so as to approach the temperature at which frost is generated. The temperature sensor 39 sends information on the temperature detected by the evaporator 38 to the control computer C, and when the detected temperature falls below the set temperature, the control computer C commands the demagnetization of the solenoid 33. When the solenoid 33 is demagnetized, the pressure supply passage 31 is opened, and the discharge chamber 3b and the crank chamber 2a communicate with each other. Therefore, the high-pressure refrigerant gas in the discharge chamber 3b is supplied to the crank chamber 2a via the pressure supply passage 31, and the pressure in the crank chamber 2a increases. Due to the pressure increase in the crank chamber 2a, the inclination angle of the swash plate 15 quickly shifts to the minimum inclination angle. That is, the electromagnetic on-off valve 32 constitutes a refrigerant circulation blocking means.

When the transmission cylinder 28 is pressed against the inner ring 25b of the deep groove ball bearing member 25, when the swash plate 15 approaches the minimum inclination angle, the tip of the throttle body 21 approaches the positioning surface 27. By this approaching operation, the cross-sectional area of the refrigerant gas passage from the suction passage 26 to the suction chamber 3a is gradually reduced. This throttling action gradually reduces the amount of refrigerant gas flowing from the suction passage 26 into the suction chamber 3a. Therefore, the amount of the refrigerant gas sucked from the suction chamber 3a into the cylinder bore 1a also gradually decreases, and the discharge capacity gradually decreases. As a result, the discharge pressure gradually decreases, and the torque in the compressor does not change greatly in a short time.

As shown in FIGS. 4 and 6, when the tip of the small diameter portion 21b of the throttle body 21 contacts the positioning surface 27, the swash plate inclination angle becomes the minimum. Since the minimum inclination of the swash plate is not 0 °,
Discharge from the cylinder bore 1a to the discharge chamber 3b is performed even in the state where the swash plate inclination angle is minimum. Cylinder bore 1a
The refrigerant gas discharged from the discharge chamber 3b from the pressure supply passage 3
1 and flows into the crank chamber 2a. Crank chamber 2a
The refrigerant gas therein flows into the suction chamber 3a through the passage 30 and the pressure release passage of the pressure release port 21c, and the refrigerant gas in the suction chamber 3a is sucked into the cylinder bore 1a and discharged to the discharge chamber 3b. That is, when the tilt angle of the swash plate is at a minimum, the discharge chamber 3b, which is the discharge pressure region, the pressure supply passage 31, the crank chamber 2
a, a passage 30, a pressure release port 21c, a suction passage 3a which is a suction pressure region, and a circulation passage through the cylinder bore 1a are formed in the compressor, and pressure is provided between the discharge chamber 3b, the crank chamber 2a, and the suction chamber 3a. There is a difference. At this time, the passage cross-sectional area of the pressure release passage is S ₁ , and the lubricating oil flowing with the refrigerant gas lubricates the inside of the compressor.

When the cooling load increases from the state of FIG. 6,
This increase in the cooling load appears as a temperature rise in the evaporator 38, and the detected temperature in the evaporator 38 exceeds the set temperature. The control computer C commands the excitation of the solenoid 33 based on this detected temperature shift. Solenoid 33
The pressure supply passage 31 is closed by the excitation of the crank chamber 2a.
The pressure is reduced based on the pressure released through the passage 30 and the pressure release port 21c. Due to this pressure reduction, the tilt angle of the swash plate 15 shifts from the minimum tilt angle to the maximum tilt angle.

As the tilt angle of the swash plate 15 increases, the throttle body 21 follows the tilting of the swash plate 15 by the spring force of the suction passage opening spring 24, and the tip of the throttle body 21 moves away from the positioning surface 27. By this separation operation, the suction passage 26 is moved from the suction chamber 3a.
The cross-sectional area of passage of the refrigerant gas gradually increases during the period.
This gradually increasing passage cross-sectional area gradually increases the amount of refrigerant gas flowing from the suction passage 26 into the suction chamber 3a.
Therefore, the amount of refrigerant gas sucked from the suction chamber 3a into the cylinder bore 1a also gradually increases, and the discharge capacity gradually increases. As a result, the discharge pressure gradually increases, and the torque in the compressor does not greatly change in a short time.

From the state shown in FIG. 5, the air conditioner operation switch 40
Even when the solenoid 33 is demagnetized due to the turning OFF of the engine or a sudden change in the engine speed, the swash plate tilt angle shifts from the maximum tilt angle to the minimum tilt angle. When the air conditioner operation switch 40 is turned on or the sudden rotation speed fluctuation of the engine disappears from the state of FIG. 6, the solenoid 33 is excited, and when there is a cooling load, the swash plate tilt angle shifts from the minimum tilt angle to the maximum tilt angle.

When the vehicle engine is stopped, the operation of the compressor is also stopped, the solenoid 33 is demagnetized, and the swash plate tilt angle shifts to the minimum tilt angle. Therefore, when the compressor is stopped, the swash plate 15 is held at the minimum tilt angle.

The connecting passage 21d on the throttle body 21 is not connected to the inlet 14a of the passage 14 during the transition of the swash plate 15 from the minimum inclination angle to the intermediate inclination position shown by the chain line in FIG. In this state, the passage cross-sectional area of the pressure release passage from the crank chamber 2a to the suction chamber 3a is equal to the passage cross-sectional area S _{1 at the} pressure release passage 21c.
Is. The discharge of the refrigerant gas from the crank chamber 2a to the suction chamber 3a is subjected to a throttling action at the pressure release port 21c of the passage cross-sectional area S ₁ , and the pressure reduction in the crank chamber 2a is slow. The time required for the swash plate tilt angle to shift from the minimum tilt angle to the maximum tilt angle depends on the size of the passage cross-sectional area S ₁ .

The ISC 42 performs feedback control for sampling the rotational speed information from the rotational speed detector 41 and converging the rotational speed during idling to a target value. When the swash plate tilt angle suddenly shifts from the minimum tilt angle to the maximum tilt angle, the load torque in the compressor sharply increases, and the rotation speed during idling sharply drops. If the number of revolutions during idling drops sharply, the feedback control of the ISC 42 cannot follow and an engine stall occurs, or the control computer C frequently repeats the excitation / demagnetization command of the electromagnetic opening / closing valve 32.

The graphs of FIGS. 8A, 8B and 8C are
Variations of the intake pressure, the discharge pressure, the pressure in the crank chamber, the engine speed, the demagnetization of the electromagnetic opening / closing valve 32, and the duty ratio control of the ISC 42 are shown. Curves Ps ₁ , Ps ₂ , Ps ₃ are suction pressures, curves Pd ₁ , Pd ₂ , Pd ₃ are discharge pressures, curve Ne
₁ , ₁ , Ne ₂ and Ne ₃ are engine speeds and curves Sw ₁ and S
w ₂ and Sw ₃ are the demagnetization of the solenoid valve 32, and the curves D ₁ and D
₂ and D ₃ represent duty ratios. The horizontal axis represents time, and time t ₀ is the time point at which the electromagnetic opening / closing valve 32 is switched between excitation and demagnetization.

The graphs of FIGS. 8 (a) and 8 (b) are experimental data in the case where the cross-sectional area of passage of the pressure release passage from the crank chamber to the suction chamber is always constant regardless of the swash plate inclination angle. The cross-sectional area of passage in this case is (S ₁ + S ₂ ). Assuming that the target speed of feedback control of the ISC 42 when the electromagnetic opening / closing valve 32 is excited is N ₁ and the target speed of feedback control of the ISC 42 when the electromagnetic opening / closing valve 32 is demagnetized is N ₂ , The experimental data of (a) is N ₁ > N ₂
The experimental data of FIG. 8 (b) is obtained by setting the target rotational speed of the feedback control of the ISC 42 to N.
It was obtained by setting only ₂ . Target speed N ₁
Is set in consideration of the maximum load torque when the compressor is at the maximum tilt angle.

The passage cross-section of the pressure release passage, which is one of the experimental conditions, is fixed to the passage cross-section (S ₁ + S ₂ ) for stably maintaining the maximum inclination state, as shown in FIGS. In the case of the experiment b), the swash plate tilt angle suddenly shifts from the minimum tilt angle to the maximum tilt angle. Therefore, the variation of the load torque in the clutchless compressor during the period from the minimum tilt angle to the maximum tilt angle is steep as compared with the case of the present embodiment. In the experiment of FIG. 8 (a), when the electromagnetic on-off valve 32 is excited, that is, when the swash plate tilt angle can be shifted to the maximum tilt angle, the target rotation speed at idling is increased. Even if the load torque increases rapidly, engine stall and frequent excitation / demagnetization of the electromagnetic on-off valve 32 do not occur frequently. However, increasing the target rotation speed during idling deteriorates the fuel efficiency of the vehicle.

In the experiment of FIG. 8B, since the target rotation speed during idling is not increased, the engine rotation speed sharply increases and decreases immediately after time t ₀ and the electromagnetic opening / closing valve 32 frequently repeats excitation / demagnetization. That is, the feedback control of the ISC 42 cannot follow the rapid decrease in the engine speed due to the rapid increase in the load torque in the clutchless compressor, which may cause an engine stall.

FIG. 8C shows experimental data when the clutchless compressor of this embodiment is used. In the case where the swash plate 15 is located in the middle tilt angle range excluding the vicinity of the maximum tilt angle and in the vicinity of the minimum tilt angle connected to this range, the crank chamber 2a to the suction chamber 3a
The passage cross-sectional area S ₁ of the pressure release passage reaching the above is smaller than the passage cross-sectional area (S ₁ + S ₂ ) for stably maintaining the maximum inclination state. Therefore, the time required for the swash plate 15 to reach the maximum tilt angle from the minimum tilt angle is longer than that in the experiment of FIGS. 8A and 8B, and crackless between the minimum tilt angle and the maximum tilt angle. The increase in load torque in the compressor is slow. Therefore, the feedback control of the ISC 42 can follow the engine speed fluctuation due to the increase of the load torque in the clutchless compressor, and the drop of the engine speed immediately after the time t ₀ can be suppressed. That is, when the swash plate 15 is in the maximum inclination state, the passage cross-sectional area (S ₁ + S
_In the present embodiment in which the passage cross-sectional area S ₁ of the pressure release passage when the swash plate 15 is in the intermediate inclination range is smaller than that in ₂ ), there is no risk of engine stall.

In the present embodiment, the swash plate 15 is tilted by the throttle body 21 which can be switched between the closed position where the refrigerant gas cannot be introduced and the open position where the refrigerant gas can be introduced from the external refrigerant circuit 35 to the suction chamber 3a which is the suction pressure region. The coolant circulation blocking means is configured in conjunction with each other. By adopting such a refrigerant circulation blocking means, frost is prevented from being generated in the evaporator 38 when there is no cooling load, and the effect of suppressing the torque fluctuation when switching between the maximum inclination angle and the minimum inclination angle of the swash plate 15 is extremely high. Become higher.
The opening and closing of the pressure supply passage 31 will be repeated frequently depending on the increase / decrease of the cooling load, but it is turned on / off due to the high tor fluctuation suppression effect of the refrigerant circulation blocking means of the present embodiment.
There is no shock.

Next, a second embodiment will be described with reference to FIGS. In this embodiment, a capacity control valve 43 is attached to the rear housing 3 as shown in FIG. The pressure in the crank chamber 2a is controlled by the capacity control valve 43. A valve housing 44 that constitutes the displacement control valve 43 is provided with a pressure supply port 44a, a suction pressure introduction port 44b, and a discharge pressure introduction port 44d. The pressure supply port 44a is connected to the crank chamber 2a via a passage 56. An inlet 45c of a passage 45 communicating with the suction chamber 3a opens at the inner peripheral surface of the accommodation hole 13. A pair of connecting passages 21d and 21g are formed in the throttle body 21A. First
The connection passage 21d serving as the branch passage and the connection passage 21g serving as the second branch passage can be connected to the inlet 45c. The suction pressure introducing port 44b communicates with the suction passage 26 through the suction pressure introducing passage 46, and the discharge pressure introducing port 44d communicates with the discharge chamber 3b through the discharge pressure introducing passage 48.

The pressure in the suction pressure detecting chamber 49 communicating with the suction pressure introducing port 44b is adjusted by the adjusting spring 5 through the diaphragm 50.
Oppose 1. The spring force of the adjusting spring 51 is the diaphragm 5
It is transmitted to the valve body 53 via 0 and the rod 52. Disc 5
The spring force of the return spring 54 acts on 3. Valve body 53
The spring action direction of the return spring 54 with respect to is the direction to close the valve hole 44e, and the valve body 53 which receives the spring action of the return spring 54 opens and closes the valve hole 44e according to the fluctuation of the suction pressure in the suction pressure detection chamber 49. .

The passage cross-sectional area of the connection passage 21d, which is the first branch passage, is the same as the passage cross-sectional area S ₁ of the above embodiment.
The passage cross-sectional area of the connection passage 21g, which is the second branch passage, is the same as the passage cross-sectional area S ₂ of the above embodiment. When the swash plate tilt angle is the maximum tilt angle, the connection passage 21d and the connection passage 21
g connects to the inlet 45c. That is, when the swash plate 15 is in the maximum inclination state, the passage cross-sectional area of the pressure release passage from the crank chamber 2a to the suction chamber 3a is (S ₁ + S ₂ ), and the maximum inclination state is stably maintained. When the swash plate 15 is in the range from the intermediate tilt position shown by the chain line in FIG. 10 to the minimum tilt position in FIG. 11, the connection passage 21d is connected only to the inlet 45c. When the suction pressure is high (the cooling load is large) when the solenoid 33 is excited and the pressure supply passage 31 is closed, the valve body 5
The valve opening degree of 3 becomes small. When the valve opening degree of the valve body 53 becomes smaller, the amount of refrigerant gas flowing from the discharge chamber 3b into the crank chamber 2a becomes smaller. Therefore, the pressure in the crank chamber 2a decreases. Further, since the suction pressure in the cylinder bore 1a is also high, the difference between the pressure in the crank chamber 2a and the suction pressure in the cylinder bore 1a becomes small. Therefore, as shown in FIG. 10, the swash plate inclination angle becomes large.

On the contrary, the suction pressure is low (the cooling load is small).
In this case, the valve opening degree of the valve element 53 becomes large and the amount of refrigerant gas flowing from the discharge chamber 3b into the crank chamber 2a becomes large. Therefore, the pressure in the crank chamber 2a rises. Further, since the suction pressure in the cylinder bore 1a is low, the difference between the pressure in the crank chamber 2a and the suction pressure in the cylinder bore 1a becomes large. Therefore, the tilt angle of the swash plate becomes small.

When the suction pressure becomes extremely low (no cooling load), the valve body 53 fully opens the valve hole 44e as shown in FIG. When the solenoid 33 is demagnetized, the valve element 34 opens the valve hole 32a and the pressure supply passage 31 opens, as shown in FIG. Therefore, the pressure increase in the crank chamber 2a is rapid, and the tilt angle of the swash plate 15 quickly shifts to the minimum tilt side.

When the solenoid 33 is excited from the state shown in FIG. 12, the pressure supply passage 31 is shut off and the swash plate 15 shifts from the minimum tilt angle side to the maximum tilt angle side. Also in this embodiment, the passage cross-sectional area of the pressure release passage from the crank chamber 2a to the suction chamber 3a becomes S ₁ while the swash plate 15 moves from the minimum tilt position to the intermediate tilt position shown by the chain line in FIG. Therefore, the tilt angle of the swash plate 15 increases slowly, and there is no risk of engine stall.

In the third embodiment of FIGS. 13 (a) and 13 (b),
The inlet 45c of the passage 45 is always connected to the connecting passage 21d, and the passage cross-sectional area of this connecting portion continuously changes according to the change of the swash plate inclination angle. The passing cross-sectional area at the maximum tilt angle is (S ₁ + S ₂ ), and the passing cross-sectional area at the minimum tilt angle is S ₁ . The continuous change in the cross-sectional area of the passage can also slow the increase in the tilt angle of the swash plate 15.

In the fourth embodiment shown in FIGS. 14 to 17, the connecting cylinder 57 is slidably supported on the rotary shaft 9. A circlip 58 is provided between one end of the connecting cylinder 57 and the swash plate 15.
And the flange portion 57 at the other end of the connecting cylinder 57.
a is engaged with the inner ring 25b of the deep groove ball bearing member 25. The transmission cylinder 28 is supported on the connecting cylinder 57. The transmission cylinder 28 is always in contact with both the swash plate 15 and the inner ring 25b. Therefore, the throttle body 21 is connected to the connecting cylinder 57 and the transmission cylinder 2.
8 is connected to the swash plate 15 through the diaphragm body 21.
Is linked to the tilting of the swash plate 15. Therefore, the suction passage opening spring 24 in each of the above embodiments is unnecessary.

The passage 14 in the cylinder block 1 has a second passage.
An inlet 14a serving as a branch passage and an inlet 14b serving as a third branch passage are formed. As shown in FIGS. 14 and 15, when the swash plate inclination angle is near the maximum, the connection passage 21d on the throttle body 21 is connected to the inlet 14a. As shown in FIG. 16, when the swash plate tilt angle is near the minimum tilt angle, the connection passage 21d connects to the inlet 14b. The passage cross-sectional area of the pressure release passage from the crank chamber 2a to the suction chamber 3a changes as shown by a curve E _{2 in} the graph of FIG. The connection passage 21d is the second
In the range of the intermediate tilt angle where the inlet 14a serving as the branch passage and the inlet 14b serving as the third branch passage are not connected, the passage cross-sectional area of the pressure release passage is the pressure release passage 21 serving as the first branch passage.
The cross sectional area S _{1 of} c is obtained. Therefore, the increase in the load torque during the transition of the swash plate 15 from the minimum tilt angle to the maximum tilt angle becomes slow, and there is no risk of engine stall. The minimum inclination angle is the same as the case where the passage cross-sectional area in the pressure release passage is the maximum inclination angle. Therefore, the amount of circulating oil in the compressor is larger than that in each of the above-described embodiments, and the lubrication in the compressor in the minimum tilt angle state is better than that in each of the above-described embodiments.

In the fifth embodiment shown in FIGS. 18 and 19,
The throttle body 21B has a pressure release port 21 serving as a first branch passage.
c, a connection passage 21d serving as a second branch passage, and a connection passage 21e serving as a third branch passage are formed. FIG.
When the swash plate tilt angle is near the maximum as shown in FIG. 5, the connection passage 21d is connected to the inlet 14a of the passage 14. As shown in FIG. 19, when the swash plate tilt angle is near the minimum tilt angle, the connection passage 21e connects to the inlet 14a. Therefore, the passage cross-sectional area of the pressure release passage from the crank chamber 2a to the suction chamber 3a changes as shown by the curve E _{2 in} the graph of FIG. Therefore, the increase in the load torque during the transition of the swash plate 15 from the minimum tilt angle to the maximum tilt angle becomes slow, and there is no risk of engine stall. Further, at the minimum inclination angle, the passage cross-sectional area in the pressure release passage is the same as at the maximum inclination angle, and the lubrication inside the compressor in the minimum inclination angle state is as good as in the fourth embodiment.

In the sixth embodiment shown in FIGS. 20 and 21,
A swash plate support member 20 having a spherical shape is slidably supported on the rotating shaft 9, and a swash plate 15 is supported on the swash plate support member 20 so as to be tiltable in the axial direction of the rotating shaft 9. Accommodation hole 13
The throttle body 21C slidably accommodated in the rotary shaft 9
It is slidably supported above. A transmission cylinder 28 is provided between the swash plate support 20 and the deep groove ball bearing member 25.
It is slidable above. One end of the transmission cylinder 28 can come into contact with the end surface of the swash plate support 20.
The other end can contact only the inner ring 25b without contacting the outer ring 25a of the deep groove ball bearing member 25. Diaphragm 21
The swash plate support 20 moving to the C side presses the transmission cylinder 28 against the inner ring 25b of the deep groove ball bearing member 25. Since the transmission cylinder 28 is sandwiched between the swash plate support 20 and the inner ring 25b,
The transmission cylinder 28 will rotate together with the rotating shaft 9. Since the transmission cylinder 28 contacts only the inner ring 25b with respect to the deep groove ball bearing member 25, the rotary shaft 9, the swash plate support 20, the transmission cylinder 28 and the inner ring 25b rotate integrally, and the swash plate support 2
0, no sliding contact occurs between the transmission cylinder 28 and the inner ring 25b.

A groove 13a connected to the crank chamber 2a is formed in the accommodation hole 13. The throttle body 21C is formed with a pressure release port 21c serving as a first branch passage and a connection passage 21f serving as a second branch passage. As shown in FIG. 20, when the swash plate inclination angle is close to the maximum, the connecting passage 21f has the groove 1
Connect to 3a. When the swash plate tilt angle is in the range from the intermediate tilt position shown by the chain line in FIG. 20 to the minimum tilt position shown in FIG. 21, the connection passage 21f is disconnected from the connection with the groove 13a. Therefore, the passage cross-sectional area of the pressure release passage from the crank chamber 2a to the suction chamber 3a changes as shown by the curve E _{1 in} the graph of FIG. Therefore, the increase in the load torque during the transition of the swash plate 15 from the minimum tilt angle to the maximum tilt angle becomes slow, and there is no risk of engine stall.

Further, the present invention provides a capacity control valve (corresponding to the capacity control valve 43 of the second embodiment) on a passage (corresponding to the throttle passage 56 of the second embodiment) for supplying the refrigerant gas from the discharge chamber to the crank chamber. ) Is used to control the pressure in the crank chamber, the clutchless compressor can also be applied.

Further, the present invention can adopt the structure of the refrigerant circulation blocking means for stopping the inflow of the refrigerant gas from the external refrigerant circuit to the suction chamber by the electromagnetic opening / closing valve as disclosed in Japanese Patent Laid-Open No. 3-37378. .

As the suction pressure region, in addition to the suction chamber 3a, there are the through hole 4c and the accommodation hole 13 partitioned from the crank chamber 2a by the throttle bodies 21, 21A, 21B, 21C.

As the discharge pressure area, in addition to the discharge chamber 3b,
There is an external refrigerant circuit inside the outlet 1b and between the outlet 1b and the condenser 36.

[0072]

As described in detail above, according to the present invention, in a part of the intermediate tilt angle range between the maximum tilt angle and the minimum tilt angle of the swash plate, the oblique cross-sectional area of the pressure relief passage is narrowed by the throttle body. The throttle body is interlocked with at least a part of the inclination of the plate, and the pressure release passage when the swash plate is in the intermediate inclination range is larger than the passage cross-sectional area of the pressure release passage when the swash plate is in the maximum inclination state. Since the passage cross-sectional area is made small, the inclination of the swash plate slowly changes from the minimum inclination to the maximum inclination, the increase of the load torque in the compressor slows down, and the excellent effect of preventing engine stall can be achieved. Play.

According to the second aspect of the invention, the throttle body is arranged so as to be switchable between a closed position where the refrigerant gas cannot be introduced and an open position where the refrigerant gas can be introduced from the external refrigerant circuit to the suction pressure region. Since the refrigerant circulation blocking means is configured such that the throttle body is in the closed position when the swash plate is tilted at the minimum tilt angle, the torque in the compressor at the time of blocking the refrigerant circulation and at the time of releasing the refrigerant circulation blocking is set. It has an excellent effect that it is possible to prevent a sudden change in the short time.

According to the third aspect of the present invention, when the swash plate is at the maximum tilt angle, the throttle body is arranged at a position to open the second branch passage, and when the swash plate is at the intermediate tilt angle range, the throttle body is at the second tilt path. Since the first branch passage is arranged to be closed and the first branch passage is always open, the first branch passage flows with the refrigerant gas even in the minimum inclination state in which the refrigerant gas is prevented from flowing into the suction pressure region from the external refrigerant circuit. It has an excellent effect that the inside of the compressor can be lubricated by the lubricating oil.

In the inventions according to claims 4 to 7, when the swash plate shifts from the intermediate tilt angle range to the minimum tilt angle, the passage cross-sectional area of the pressure release passage increases, so that the suction pressure region from the external refrigerant circuit is increased. There is an excellent effect that the lubrication inside the compressor can be improved in the minimum tilt angle state in which the refrigerant gas flow into the compressor is blocked.

[Brief description of drawings]

FIG. 1 is a side sectional view of an entire compressor according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a side sectional view of the entire compressor in a state where the swash plate tilt angle is at a minimum.

FIG. 5 is an enlarged sectional view of an essential part in which the swash plate inclination angle is at a maximum.

FIG. 6 is an enlarged cross-sectional view of a main part in a state where the swash plate inclination angle is minimum.

FIG. 7 is a graph showing a change in passage cross-sectional area in the pressure release passage.

8 (a) and 8 (b) are a case where the passage cross-sectional area of the pressure relief passage is constant, and FIG. 8 (c) is a suction pressure, a discharge pressure, and a crank chamber when the passage cross-sectional area of the pressure relief passage is changed. 3 is a graph showing changes in pressure, engine speed, excitation / demagnetization of the electromagnetic opening / closing valve 32, and duty ratio control of the ISC 42.

FIG. 9 is a side sectional view of the entire compressor showing a second embodiment.

FIG. 10 is an enlarged cross-sectional view of an essential part in which the swash plate tilt angle is at a maximum.

FIG. 11 is an enlarged cross-sectional view of a main part in a state where the swash plate inclination angle is at a minimum.

FIG. 12 is an enlarged cross-sectional view of a main part in a state where the swash plate tilt angle is at a minimum.

13A and 13B show a third embodiment, FIG. 13A is an enlarged cross-sectional view of an essential part in which the swash plate tilt angle is at a maximum state, and FIG.

FIG. 14 is a side sectional view of an entire compressor showing a fourth embodiment.

FIG. 15 is an enlarged cross-sectional view of a main part in which the swash plate tilt angle is in the maximum state.

FIG. 16 is an enlarged sectional view of an essential part in which the swash plate tilt angle is at a minimum state.

FIG. 17 is a graph showing a change in passage cross-sectional area in the pressure release passage.

FIG. 18 is an enlarged cross-sectional view of an essential part showing the fifth embodiment and in a state where the swash plate tilt angle is at a maximum.

FIG. 19 is an enlarged cross-sectional view of a main part in a state where the swash plate tilt angle is at a minimum.

FIG. 20 is an enlarged cross-sectional view of a main part of the sixth embodiment, in which the swash plate tilt angle is at the maximum state.

FIG. 21 is an enlarged sectional view of an essential part in which the swash plate inclination angle is at a minimum.

[Explanation of symbols]

2a ... Crank chamber, 3a ... Suction chamber serving as suction pressure region, 1
4, 30 ... Passages forming pressure release passages, 14a ... Inlet serving as second branch passages, 14b ... Inlet serving as third branch passages, 15 ... Swash plate, 21, 21A, 21B, 21C ... Refrigerant circulation blocking Means and a diaphragm body constituting the minimum tilt angle defining means,
27 ... Positioning surface 21c that constitutes the minimum tilt angle defining means
... a pressure release passage serving as a first branch passage, 21d ... a connection passage,
31 ... Pressure supply passage, 32 ... Electromagnetic on-off valve forming refrigerant circulation blocking means, 35 ... External refrigerant circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohiko Yokono 2-chome Toyota-cho, Kariya city, Aichi, Ltd. Inside Toyota Industries Corporation (58) Fields investigated (Int.Cl. ⁷ , DB name) F04B 27 / 14

Claims (7)

(57) [Claims] 1. A rotary support is fixedly attached to a rotary shaft in a housing for accommodating a single-headed piston in a cylinder bore for reciprocal linear movement, and a swash plate is tiltably supported on the rotary support.
The tilt angle of the swash plate is controlled according to the difference between the pressure in the crank chamber and the suction pressure via the single-headed piston, and the pressure in the discharge pressure region is supplied to the crank chamber and the pressure in the crank chamber is discharged to the suction pressure region. In a clutchless one-sided piston type variable displacement compressor that regulates the pressure in the crank chamber, a minimum inclination regulating means that regulates the minimum inclination angle of the swash plate, and a refrigerant circulation blocking means that stops the refrigerant circulation in the external refrigerant circuit in the minimum capacity state. A part of an intermediate tilt angle range between the maximum tilt angle and the minimum tilt angle of the swash plate, the throttle body being capable of advancing and retracting on the pressure release passage for releasing the pressure in the crank chamber to the suction pressure region. Then, the throttle body is interlocked with at least part of the tilting of the swash plate so that the passage cross-sectional area of the pressure release passage is narrowed by the throttle body, and the passage of the pressure release passage when the swash plate is in the maximum inclination state. Than cross section A clutchless one-sided piston type variable displacement compressor configured to reduce a passage cross-sectional area of the pressure release passage when the swash plate is in the intermediate tilt angle range. 2. The throttle body is switchably arranged between a closed position where the refrigerant gas cannot be introduced from an external refrigerant circuit to the suction pressure region and an open position where the refrigerant gas can be introduced, and the throttle body is tilted by the swash plate. The clutchless one-side piston type variable displacement compressor according to claim 1, wherein the refrigerant circulation blocking means is configured so that the throttle body is in the closed position when the swash plate has the minimum inclination angle. 3. The pressure relief passage is branched into a first branch passage and a second branch passage, and when the swash plate is at the maximum inclination angle, the throttle body is arranged at a position to open the second branch passage. Is
The throttle body is arranged at a position to close the second branch passage when the swash plate is in the intermediate inclination range, and the first branch passage is always open. The clutchless one-sided piston type variable displacement compressor described. 4. The cross-sectional area of passage of the pressure relief passage when the swash plate is in the intermediate tilt angle range is smaller than the cross-sectional area of passage of the pressure relief passage when the swash plate is in the minimum tilt angle state. The clutchless one-sided piston type variable displacement compressor according to any one of claims 1 and 2. 5. The pressure relief passage is branched into a first branch passage, a second branch passage, and a third branch passage, and when the swash plate is at the maximum inclination, the throttle body is provided with the second branch passage. The passage is opened and the third branch passage is closed, and when the swash plate is in the intermediate tilt angle range, the throttle body is arranged at a position closing the second branch passage and the third branch passage.
The throttle body is arranged to close the second branch passage and open the third branch passage when the swash plate is at the minimum inclination angle, and the first branch passage is always open. Clutchless one side piston type variable displacement compressor. 6. The clutchless one-side piston type variable displacement compressor according to claim 3, wherein the first branch passage of the pressure release passage passes through a throttle body. 7. A connection passage is provided in the throttle body, and when the swash plate is at the maximum inclination angle, the connection passage and the second passage are formed.
The throttle body is arranged at a position where it is connected to the branch passage, and the throttle body is arranged at a position where the connection passage is not connected to the second branch passage and the third branch passage when the swash plate is in the intermediate tilt angle range, The clutchless one-side piston type variable displacement compressor according to claim 5, wherein the throttle body is arranged at a position where the connection passage and the third branch passage are connected to each other when the swash plate is at the minimum inclination angle.