JP3269169B2 - Oscillating swash plate 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 relates to a swash plate type variable displacement compressor used in, for example, an air conditioner of an automobile.

[0002]

2. Description of the Related Art Generally, a variable displacement compressor for air conditioning of an automobile is equipped with an electromagnetic clutch for connecting and disconnecting the power of an engine. When the clutch is operated, the rotational motion of the engine is transmitted to the compressor via the belt transmission mechanism and the electromagnetic clutch. Therefore, every time the air conditioner switch is turned on and off, the compressor starts up with a large capacity.
The electromagnetic clutch is stopped, and its durability is reduced due to frequent repetition of connection and disconnection of the electromagnetic clutch. In addition, the starting shock of the compressor also occurs, and the compressor becomes large and heavy, and it is difficult to mount the compressor due to the installation space in the engine room.

In order to solve the above problem, a clutchless swinging swash plate type variable displacement compressor has been proposed. As this compressor, there is a compressor disclosed in Japanese Utility Model Laid-Open Publication No. 61-37479. This compressor changes the maximum stroke of the piston by continuously changing the inclination angle of the swash plate by controlling the pressure difference between the pressure in the crank chamber in which the swash plate is housed and the pressure in the working chamber in the cylinder bore during the suction stroke. And or,
This compressor responds to the ON signal of the air conditioner switch,
A hydraulic actuator is provided which pushes the swash plate from the zero degree position and moves the swash plate to an inclination position larger than zero degree.
Then, when it is desired to change the operation from the zero-volume operation to the compression operation, lubricating oil is pumped from an oil storage chamber formed below the crank chamber by an oil supply pump. Then, an actuator connected to the pump discharge side is driven to return the swash plate from the zero-degree position to the inclined position. Further, when the compressor is switched from the compression operation to the zero-capacity operation, the high-pressure refrigerant gas in the discharge chamber is guided to the crank chamber through the air supply passage, and the above-described differential pressure acting before and after the piston is rapidly increased. The swash plate is shifted to a zero degree position. In this compressor, a bleed passage is formed to recirculate the gas blown into the crank chamber from the working chamber in the cylinder bore through the gap on the outer peripheral surface of the piston to the suction chamber.

[0004]

The compressor is switched from a compression operation to a zero-capacity state by supplying a large amount of refrigerant gas into the crank chamber from the compression operation, and thereafter the operation is stopped. If the temperature of the outside air is low in this stopped state, the temperature in the crank chamber also decreases, and the refrigerant gas liquefies. Also, a part of the liquid refrigerant flows into the compressor from the external refrigerant gas line, and tends to accumulate at the bottom of the crank chamber. Therefore, a large amount of liquid refrigerant having a large specific gravity is stored at the bottom of the oil storage chamber, and the lubricating oil is stored thereon. In this state, when the compressor is started to the zero displacement operation, the following problem occurs. That is, the bleed passage for returning the gas in the crank chamber to the suction chamber is always open. Therefore, when the compressor is started in the zero capacity operation, the rotation of the swash plate gasifies the liquid refrigerant in the crank chamber and increases the pressure in the crank chamber. When this gas flows into the suction chamber from the bleed passage, the lubricating oil also blows up and flows out to the suction chamber. For this reason, there is a problem that even when the swash plate tilt angle hydraulic pressure returning mechanism is operated to return the swash plate from the zero-degree state to the inclined state, the swash plate cannot return due to lack of lubricating oil.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art, and to start the zero-capacity operation of the compressor in a stopped state in which liquid refrigerant exists in the crank chamber due to a low temperature outside the compressor. Oscillating swash plate type variable that can prevent the lubricating oil from flowing out of the crank chamber to the suction chamber and reliably return the swash plate from the non-operation position to the operation position by the swash plate inclination hydraulic pressure return mechanism It is to provide a capacity compressor.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a crank which acts on a back surface of a piston by compressing a refrigerant gas sucked from a suction chamber into a cylinder bore and discharging the compressed gas to a discharge chamber. An oscillating swash plate type variable displacement compressor that adjusts the discharge capacity by changing the reciprocating stroke of the piston by changing the inclination angle of the swash plate by the differential pressure between the chamber pressure and the pressure in the bore acting on the front surface. A swash plate tilt angle compulsory change mechanism for changing the tilt angle of the swash plate from an operating position to a non-operating position, and a mechanism for urging the swash plate held in the non-operating position to the non-operating position during rotation. A swash plate tilt angle hydraulic return mechanism including an oil supply pump for returning the tilt angle of the swash plate from the non-operation position to the operation position by using lubricating oil stored in the crank chamber, and the cylinder bore. Inside A bleed passage that is interposed in the middle of a bleed passage that guides the refrigerant gas blow-by into the crank chamber from the working chamber through the outer peripheral gap of the piston to the suction chamber, and that detects the temperature inside the compressor and the detected temperature is lower than the set temperature. And a temperature-sensitive control valve that increases the opening of the bleed passage when it is high.

[0007]

According to the present invention, when the start switch of the engine is turned on, a zero displacement operation of the compressor in which the swash plate is held at the non-operation position by the urging means is started. In this state,
For example, when the swash plate inclination hydraulic pressure return mechanism is operated by turning on a switch of the air conditioner, the swash plate is displaced from the non-operation position to the inclination position. Therefore, the compression operation of the compressor is performed, and the refrigerant gas is sucked into the suction chamber from the external refrigerant gas suction pipe,
After this refrigerant gas is drawn into the working chamber in the cylinder bore,
The air is compressed in the working chamber, discharged to the discharge chamber, and discharged to the external refrigerant gas discharge pipe. During the compression operation, the tilt angle of the swash plate is changed by the pressure difference between the crank chamber pressure acting on the back surface of the piston and the working chamber pressure acting on the front surface, thereby changing the reciprocating stroke of the piston and adjusting the discharge capacity. .
Also, refrigerant gas containing lubricating oil is blow-by from the working chamber in the bore to the crank chamber through the outer peripheral gap of the piston, the lubricating oil is stored in the lower part of the crank chamber, and the blow-by gas is recirculated from the bleed passage to the suction chamber.

During the compression operation, the switch of the air conditioner is turned off to stop the swash plate inclination hydraulic pressure return mechanism, and when the swash plate inclination compulsory change mechanism is operated, the swash plate is displaced from the operating position to the non-operating position. , The compressor is shifted to zero displacement operation. Further, when the start switch of the engine is turned off in this state, the compressor is stopped.

[0009] When the compressor is stopped, the refrigerant gas in the crank chamber becomes liquid refrigerant due to a decrease in outside air temperature in winter, for example. Liquid refrigerant flows into the compressor from a gas pipe outside the compressor, and a part of the liquid refrigerant is accumulated in the crank chamber.
For this reason, a large amount of liquid refrigerant is stored in the lower portion of the crank chamber, and lubricating oil is stored on the liquid refrigerant. When the compressor is operated in the zero capacity state in this state, the rotation of the swash plate causes convection of the refrigerant gas in the crank chamber, whereby the liquid refrigerant forms a mist and convection in the crank chamber together with the lubricating oil. The pressure in the room also increases. However, because the temperature inside the compressor is low, the temperature-sensitive control valve in the bleed passage is closed, and the refrigerant gas, mist-like liquid refrigerant, and lubricating oil are convected without moving from the crank chamber to the suction chamber through the bleed passage. I do. When the operation of the compressor in the zero capacity state is continued for a predetermined time, all the liquid refrigerant is gasified due to a rise in the temperature in the crank chamber. For this reason, lubricating oil is separated and stored in the lower part in the crank chamber. When the operation of the compressor in the zero capacity state is continued and the temperature in the compressor rises and reaches the set temperature, the temperature-sensitive control valve provided in the bleed passage is opened, and the refrigerant gas in the crank chamber is removed from the bleed passage. From the suction chamber.

Therefore, when the switch of the air conditioner is turned on and the swash plate tilt angle hydraulic pressure return mechanism is operated, a large amount of lubricating oil is stored in the lower portion of the crank chamber, so that the swash plate is reliably inclined from the non-operation position to the inclined state. And the capacity of the compressor is reliably restored.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 2, a front housing 2 forming a crank chamber 2a is joined and fixed to a front end surface of a cylinder block 1 also serving as a center housing having a plurality of cylinder bores 1a.
An oil storage housing 2b is formed integrally with the outer periphery of the bottom of the front housing 2, and an oil storage chamber R in the housing 2b is communicated with the crank chamber 2a by a passage 2d formed in a bottom wall 2c of the front housing 2. ing. A rear housing 3 that defines a suction chamber 3a and a discharge chamber 3b is joined and fixed to the rear end of the cylinder block 1. A rotary shaft 4 is rotatably supported by the cylinder block 1 and the front housing 2 via radial bearings 5 and 6 so as to be located in the crank chamber 2a. A pulley 7 is fixed to the outer end of the rotating shaft 4,
The rotational movement of the engine is transmitted directly by the belt 8.

A rotary support 9 is fitted and fixed to the rotary shaft 4, and a thrust bearing 10 for supporting a thrust load during a compression operation is interposed between the support 9 and the inner wall of the front housing 2. A support arm 11 having an insertion hole 11a is formed integrally with the rotary support 9. On the other hand, a sleeve 1 having a spherical surface 12a
2 is supported so as to be able to reciprocate back and forth along the outer peripheral surface of the rotary shaft 4.
It is supported so as to be tiltable in the front-rear direction along 2a. A support pin 14 is rotatably supported in the insertion hole 11a of the support arm 11 in a direction perpendicular to the rotation shaft 4 as shown in FIG. The upper ends of a pair of left and right guide pins 15 and 16 are guided through guide holes 14a and 14a formed at both right and left ends of the support pin 14 so as to be slidable and parallel to each other. Furthermore, both guide pins 15, 1
6 is press-fitted and fixed to mounting holes 13b, 13b of bearings 13a, 13a integrally formed on the back surface of the swash plate 13. In this embodiment, a hinge mechanism K for allowing the swash plate 13 to reciprocate in the front-rear direction by the support arm 11, the sleeve 12, the guide pins 15, 16 and the bearing 13a.
1.

As shown in FIGS. 1 and 3, guide pins 15, 16 are provided.
Are formed such that the position of the center of gravity W of the swash plate 13 is located below the center C of the rotating shaft 4. Then, when the compressor is started by the engine, the swash plate 13 can continue rotating at the zero-degree position due to the centrifugal force acting on the center of gravity W. In this embodiment, the swash plate 1 held at the zero-degree position by the arrangement of the center of gravity W is provided.
The urging means H constitutes urging means H for urging the rotating member 3 to the same position during the rotation. Alternatively, although not shown, the rotating support 9
A coil-shaped urging spring may be interposed between the sleeve and the sleeve 12 as urging means.

As shown in FIG. 2, the swash plate 13 is inserted through a pair of front and rear shoes 18 and 18 into a recess formed at the base end of a plurality of single-headed pistons 17 housed in the cylinder bore 1a. Moored. The inclination angle of the swash plate 13 is set to zero degree,
A stopper 19 for regulating the position of the piston 17 to make the stroke of the piston 17 zero is attached. In the zero displacement operation state of the compressor, the inclination angle of the swash plate 13 does not necessarily have to be zero, and a small inclination angle at which compression is not substantially performed may be set as the non-operation position. The maximum inclination angle of the swash plate 13 is the sleeve 1
2 is regulated by contacting the step portion 4 a formed on the rotating shaft 4.

2 and 4, between the rear end surface of the cylinder block 1 and the front end surface of the rear housing 3.
As shown in FIG. 3, a valve plate 20 having a suction hole 20a and a discharge hole 20b is interposed. A suction valve plate 21 having a suction valve 21a formed on the front surface of the valve plate 20, and a discharge valve plate 22 having a discharge valve 22a formed on the rear surface.
Are joined. A retainer plate 23 having a retainer 23a for regulating an open position of the discharge valve 22a is joined to a rear surface of the discharge valve plate 22.

Next, the swash plate 13 is tilted to zero degree (non-operating).
The swash plate inclination hydraulic return mechanism K2 for returning from the position to the inclination (operation) position will be described. As shown in FIGS. 1 and 2, a cylindrical spool 24 that is slidably guided by the outer peripheral surface of the rotary shaft 4 and reciprocates in the front-rear direction is accommodated in the center hole 1 b of the cylinder block 1. A lip seal 2 is provided between the rear radial bearing 6 and the spool 24.
The position of the seal 25 is regulated by a stop ring 25A. The outer peripheral surface of the large-diameter cylindrical portion 24a formed at the tip of the spool 24 is slidably contacted with the inner peripheral surface of the central hole 1b.
A pressure chamber 26 is formed therebetween. The distal end of the large-diameter cylindrical portion 24a of the spool 24 is
When the control oil pressure is supplied to the pressure chamber 26 in a state in which the swash plate 13 is in contact with the rear end surface of the swash plate 13 from the zero degree to the inclined position, the spool 24 is guided by the rotating shaft 4 and the sleeve 12 is pushed forward. Is restored.

At the center of the rear housing 3, FIG.
As shown in FIG. 4, a trochoid type oil supply pump 27 driven by the rotary shaft 4 is accommodated. The suction port of the oil supply pump 27 is connected to the bottom of the oil storage chamber R through an oil suction passage 28 as shown in FIGS.
The discharge port of the oil supply pump 27 is connected to a rear opening of an oil passage 30 formed at the center of the rotary shaft 4 by an oil discharge passage 29. A branch oil passage 30a is formed at a plurality of locations in the oil passage 30, and the bearings 5, 6 and the crank chamber 2
a, the lubricating oil O can be supplied to the sleeve 12 and the like.

Further, a first electromagnetic on-off valve 31 is provided in the oil discharge passage 29 as shown in FIGS. 1 and 2, and an oil discharge passage 2 between the on-off valve 31 and the oil supply pump 27 is provided.
Reference numeral 9 is connected to the pressure chamber 26 via a swash plate inclination return branch supply passage 32 formed in the cylinder block 1 and the rear housing 3. When the oil discharge passage 29 is closed by the first solenoid on-off valve 31, the supply of oil to the oil passage 30 is shut off, and the swash plate is supplied from the oil supply pump 27 to the pressure chamber 26 through the branch supply passage 32. The control oil pressure for tilt return is supplied. A control device 34 is connected to an electromagnetic solenoid 33 of the first electromagnetic opening / closing valve 31, and an air conditioner switch 35 as an external signal generator is connected to the device.

The rotary shaft 4 is provided with an oil discharge passage 30b communicating the pressure chamber 26 with the oil passage 30.
4 is moved to the forward end in contact with the stopper 19, the oil discharge passage 30b is opened, and the control oil pressure supplied from the oil supply pump 27 to the pressure chamber 26 through the branch supply passage 32 is applied to the oil discharge passage 30b. To the oil passage 30.

Next, based on FIGS. 1, 2 and 8, while the swash plate 13 is in the inclined position and the compressor is being compressed, an operation signal from the control unit 34 causes the swash plate 13 to move. Swash plate tilt angle compulsory change mechanism K3 for changing the tilt angle to zero degree
Will be described.

As shown in FIGS. 1 and 2, the rear housing 3 and the cylinder block 1 have a discharge chamber 3b and a crank chamber 2a.
Is formed, and a first bleed passage 41 that connects the crank chamber 2a and the suction chamber 3a is formed. A second solenoid valve 42 is provided in the air supply passage 40. The electromagnetic solenoid of the second electromagnetic on-off valve 42 shares the electromagnetic solenoid 33 of the first electromagnetic on-off valve 31. When the second solenoid valve 42 opens the air supply passage 40 during the compression operation, high-pressure refrigerant gas is discharged from the discharge chamber 3 b through the air supply passage 40 to the crank chamber 2.
a, the pressure difference between the crank chamber pressure Pc acting on the back surface of the piston 17 and the pressure in the working chamber in the cylinder bore 1a increases, and the inclination angle of the swash plate 13 is forcibly changed to zero degrees.

During the compression operation of the compressor, the variable displacement control is automatically performed according to the cooling load. That is, the first bleed passage 4 communicating the crank chamber 2a with the suction chamber 3a.
1, a pressure control valve 43 is provided, and the pressure control valve 43 adjusts the opening degree of the first bleed passage 41 in accordance with the suction pressure Ps proportional to the cooling load, whereby the pressure difference acting on the front and rear of the piston 17 is increased. The pressure Δp is adjusted.

As shown in FIGS. 2 and 5, the upper space of the oil storage chamber R and the suction chamber 3a are communicated by a second bleed passage 50. The passage 50 allows the refrigerant gas blow-by to the crank chamber 2a to flow back to the suction chamber 3a through the gap between the outer peripheral surface of the piston 17 and the inner peripheral surface of the cylinder bore 1a during the compression stroke of the piston 17. A temperature-sensitive control valve 51 for detecting the temperature of the refrigerant gas in the suction chamber 3a and opening and closing the second bleed passage 50 is provided in the middle of the second bleed passage 50 as shown in FIG. ing. The temperature-sensitive control valve 51 has a spherical valve element 53 housed in a valve chamber 52 formed at the downstream end of the second bleed passage 50. The valve element 53 is supported by a bimetal 54. This bimetal 54 is composed of two metal plates 5 having different thermal expansion coefficients.
5 and 56, which are locked by a stopper 57 engaged in the valve chamber 52. The valve element 53 is urged in the valve opening direction by a coil spring 58. And
In a state where the compressor is stopped in winter and the temperature of the refrigerant gas in the suction chamber 3a is low, the bimetal 54 is held at a position where the valve body 53 is closed as shown in FIG. On the contrary, when the temperature is high such as in summer, the bimetal 54
And the valve body 53 is moved by the spring 58 to the second position.
The bleed passage 50 is moved to a position where it is opened.

Next, the operation of the swash plate type variable displacement compressor constructed as described above will be described. Now, when the compressor is stopped in summer, as shown in FIG. 2, since the pressure Pc in the crank chamber, the pressure Ps in the suction chamber 3a, and the pressure Pd in the discharge chamber 3b are all the same, the spool 24 retreats. As a result, the sleeve 12 is moved backward, and the swash plate 13 is stopped and held at the zero-degree position. Further, the swash plate inclination hydraulic pressure return mechanism K2 is stopped, the first electromagnetic on-off valve 31 is held at a position where the oil discharge passage 29 is opened, the swash plate inclination compulsory change mechanism K3 is stopped, and the second electromagnetic on-off valve 42 is stopped. It is held at a position where the air supply passage 40 is opened. Further, the temperature of the refrigerant gas in the suction chamber 3a is higher than the set temperature, and the temperature-sensitive control valve 51 is held at a position to open the second bleed passage 50 as shown in FIG.

When an engine (not shown) is started in this state, the rotation of the engine is directly transmitted to the rotating shaft 4 via the belt 8 and the pulley 7, and the support arm 1 of the rotating support 9 is rotated.
1 revolves around the rotation axis 4. Therefore, the swash plate 13 is rotated at the zero degree position by the hinge mechanism K1, and the zero displacement operation in the clutchless state is started. In this zero-volume operation, the first solenoid on-off valve 31 is open, so that the lubricating oil O pumped from the oil storage chamber R by the oil supply pump 27 is supplied from the oil discharge passage 29 to the oil passage 30, and the branch oil passage 30
a to the sliding portions of the bearings 5, 6 and the swash plate 13 to lubricate them. The spool 24 is not operated because the oil passage 30 has a much lower flow resistance than the branch supply passage 32 communicating with the pressure chamber 26.

Next, when the temperature in the vehicle compartment rises and the cooling load increases, and the air conditioner switch 35 is turned on, the electromagnetic solenoid 3 is actuated by the operation signal output from the controller 34.
3 is excited. Therefore, the first solenoid on-off valve 31 closes the oil discharge passage 29, so that the supply of the lubricating oil to the oil passage 30 by the oil supply pump 27 is stopped, and the pressure oil is supplied from the branch supply passage 32 to the pressure chamber 26. Is done. Therefore,
As shown in FIG. 8, the spool 24 advances, the swash plate 13 is displaced from the zero-degree position to the inclined position, and the compression operation is started. Then, the piston 17 reciprocates in the cylinder bore 1a, and the refrigerant gas sucked into the cylinder bore 1a from the suction chamber 3a is compressed in the working chamber in the bore and then discharged to the discharge chamber 3b.

Since the second solenoid valve 42 closes the air supply passage 40 by the excitation of the electromagnetic solenoid 33, the supply of the refrigerant gas from the discharge chamber 3b to the crank chamber 2a is stopped.

The spool 24 is stopped by the stopper 19 by the supply of control oil pressure to the pressure chamber 26.
Thereafter, the control oil pressure is returned to the crank chamber 2a from the oil discharge passage 30b through the oil passage 30 and the branch oil passage 30a because the oil discharge passage 30b provided on the rotary shaft 4 is opened by the advance of the spool 24.

When the temperature in the passenger compartment is low and the cooling load is small during the compression operation, the suction pressure Ps is low, and the opening of the first bleed passage 41 is reduced by the pressure control valve 43 shown in FIG. You. Therefore, the differential pressure Δp acting on the back and front surfaces of the piston 17 is kept large, and the swash plate 13
Is maintained at a small inclination angle for small capacity operation. Conversely, when the cooling load is large, the suction pressure Ps is large, so the opening of the first bleed passage 41 is increased by the pressure control valve 43. As a result, the differential pressure Δp decreases, and the swash plate 13 moves away from the spool 24 to the maximum inclination angle. Thus, during the compression operation, the first bleed passage 41 is controlled by the pressure control valve 43.
Is adjusted according to the fluctuation of the suction pressure Ps proportional to the cooling load, the differential pressure Δp acting on the piston 17 is adjusted, and the inclination of the swash plate 13 is changed according to the cooling load to adjust the discharge capacity. Is done.

During the compression operation of the compressor, refrigerant gas is supplied to the crank chamber 2a from the working chamber in the cylinder bore 1a by blowing over the outer peripheral surface of the piston 17. This gas flows into the oil storage chamber R from a passage 2 d formed in the bottom wall 2 c of the front housing 2, and is returned to the suction chamber 3 a from the second bleed passage 50 opened in the upper space of the oil storage chamber R. Therefore, the mist-like lubricating oil in the refrigerant gas moving through the oil storage chamber R is separated and stored in the oil storage chamber R. The refrigerant gas also flows from the crank chamber 2a to the suction chamber 3a through the first bleed passage 41. However, the flow rate is limited by the pressure control valve 43 and is not so large. May not be arranged in the upper space of the oil storage chamber R. However, if it is arranged, the amount of oil stored in the oil storage chamber R may be increased accordingly.

When the air conditioner switch 35 is turned off by reducing the cooling load, the electromagnetic solenoid 33 is demagnetized in FIG. For this reason, the first solenoid on-off valve 31 opens the discharge passage 29, so that the supply of the pressure oil to the pressure chamber 26 is stopped, and the spool 24 enters a free state. Further, since the air supply passage 40 is opened by the second solenoid on-off valve 42, high-pressure refrigerant gas is supplied from the discharge chamber 3 b into the crank chamber 2 a, and the swash plate 13 exerts a differential pressure Δ acting on the piston 17.
Due to the increase in p, the compressor is forcibly returned to the zero-degree position, and the compressor is switched to zero displacement operation. Further, when the engine is stopped, the compressor is stopped.

When the compressor is stopped in winter or the like, the temperature of the crank chamber 2a, the suction chamber 3a, the discharge chamber 3b, etc. in the compressor is low because the outside air temperature is low. Therefore, the refrigerant gas in the crank chamber 2a becomes a liquid refrigerant, the liquid refrigerant is stored in the lower part of the oil storage chamber R, and the lubricating oil O is stored on the liquid refrigerant. Further, a part of the liquid refrigerant flowing from the external refrigerant gas pipe into the suction chamber 3a, the discharge chamber 3b, and the working chamber in the cylinder bore 1a also flows into the crank chamber 2a.
A large amount of liquid refrigerant is stored in the crank chamber 2a.

In this state, when the engine is started and the compressor is operated in a zero capacity state, the rotation of the swash plate 13 causes a convection of the refrigerant gas in the crank chamber 2a. The mist flows in a mist form in the crank chamber. Since the liquid refrigerant is gasified in the process of the convection, the pressure in the crank chamber 2a rises and the second bleed passage 50
The refrigerant gas attempts to move to the suction chamber 3a through the passage. However, for a while after being started in the zero-capacity operation, the temperature inside the compressor is lower than the deformation temperature of the bimetal 54 of the temperature-sensitive control valve 51, so that the control valve 51 is closed. Therefore, the mist-like liquid refrigerant and lubricating oil flow through the second bleed passage 50 without moving from the crank chamber 2a to the suction chamber 3a. Then, after a lapse of a predetermined time, all the liquid refrigerant is gasified. Therefore, the lubricating oil O is stored in the oil storage chamber R.

When the zero-capacity operation of the compressor is continued for a predetermined time and the temperature of the refrigerant gas in the crank chamber 2a and the suction chamber 3a becomes higher than the deformation temperature of the bimetal 54 of the temperature-sensitive control valve 51, the bimetal 54 , The valve body 53 is displaced by the spring 58 to a position where the second bleed passage 50 is opened.

Thereafter, when the switch 35 of the air conditioner is turned on and the swash plate inclination hydraulic pressure return mechanism K2 is operated, a large amount of lubricating oil O is stored in the lower portion of the crank chamber 2a. The supply of the lubricating oil O to 26 is performed reliably. Therefore, the swash plate 13 is reliably returned from the zero-degree position to the inclined position, and the capacity return operation is reliably performed. Also, the working chamber in the cylinder bore 1a is moved from the crank chamber 2
The refrigerant gas blown into a is returned to the suction chamber 3a from the open second bleed passage 50.

The present invention is not limited to the above embodiment, but can be embodied as follows. (1) In the above embodiment, the temperature-sensitive control valve 51
Although the bleed passage 50 is configured to be opened or closed, the passage area of the bleed passage 50 is configured to be adjusted stepwise or continuously to increase or decrease.

(2) A temperature detector (not shown) for detecting the temperature in the crank chamber 2a and the temperature in the suction chamber 3a is provided, and when the detected temperature of the temperature detector exceeds a set value, An electromagnetic on-off valve (not shown) provided in the second bleed passage 50
To be open to the public.

(3) Although not shown, the swash plate inclination compulsory change mechanism K3 is constituted by an electromagnetic solenoid. (4) In the above embodiment, the refueling pump 27 is driven by the rotating shaft 4. However, only when the refueling pump 27 is separated from the rotating shaft 4 and the air conditioner switch 35 is turned on,
The lubricating oil O is supplied to the pressure chamber 26 by driving the oil supply pump 27 by, for example, an electric motor (not shown) or an electromagnetic solenoid. In this case, lubrication of each sliding portion in the crank chamber 2a is performed by another mechanism.

(5) When the oil discharge passage 30b is omitted and the spool 24 moves to the forward end and the pressure in the pressure chamber 26 exceeds a set value, the first solenoid on-off valve 31 is switched to the oil discharge passage 29. To supply the lubricating oil to the oil passage 30.

[0040]

As described above in detail, the present invention detects the temperature in the compressor in the middle of a bleed passage for guiding the refrigerant gas blow-by from the working chamber in the cylinder bore into the crank chamber through the outer peripheral gap of the piston to the suction chamber. A temperature-sensitive control valve that is opened when the detected temperature is high and closed when the detected temperature is low is provided. Therefore, even when the compressor starts the zero-capacity operation in a stopped state where the liquid refrigerant exists in the crank chamber due to a low temperature outside the compressor, it is possible to prevent the lubricating oil from flowing out of the crank chamber to the suction chamber. As a result, the swash plate can be reliably returned from the non-operation position to the operation position by the swash plate inclination hydraulic pressure return mechanism.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part showing an embodiment in which the present invention is embodied in a swash plate type variable displacement compressor.

FIG. 2 is a vertical sectional view showing the entire swash plate type variable displacement compressor in a zero capacity state.

FIG. 3 is a cross-sectional view near a hinge mechanism.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is a sectional view showing the vicinity of an oil storage chamber.

FIG. 6 is a cross-sectional view showing the temperature-sensitive control valve in a closed state.

FIG. 7 is a sectional view showing the temperature-sensitive control valve in an open state.

FIG. 8 is a partial sectional view of the compressor in a swash plate inclined state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cylinder block, 1a ... Cylinder bore, 2 ... Front housing, 2a ... Crank chamber, 2b ... Oil storage housing, 3 ... Rear housing, 3a ... Suction chamber, 3b ... Discharge chamber, 4 ... Rotary shaft, 9 ... Rotary support , 11 ... support arm, 12 ... sleeve, 12a ... spherical surface, 13 ... swash plate, 17
... Piston, 24 ... Spool, 26 ... Pressure chamber, 27 ... Oil supply pump, 31 ... First electromagnetic on-off valve, 32 ... Branch supply passage for tilt return, 33 ... Electromagnetic solenoid, 40 ... Air supply passage
42: second electromagnetic on-off valve, 50: second bleed passage, 51: temperature-sensitive control valve, R: oil storage chamber, H: urging means, W: center of gravity of swash plate, K1: hinge mechanism, K2: swash Plate inclination hydraulic pressure return mechanism, K3: Swash plate inclination compulsory change mechanism.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Takeshi 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (58) Field surveyed (Int. Cl. ⁷ , DB name) F04B 27 / 08 F04B 27/14

Claims (1)

(57) [Claims] A cylinder block in which a plurality of cylinder bores for accommodating a single-headed piston are accommodated in a housing is provided, and a crank chamber is provided in the housing to support a rotating shaft. A support is fixed, and a swash plate is mounted on the rotary support via a hinge mechanism so that the swash plate can be reciprocated in the front-rear direction. The piston is reciprocated in the cylinder bore, the refrigerant gas sucked from the suction chamber is compressed in the cylinder bore and discharged to the discharge chamber, and the pressure in the crank chamber acting on the back of the piston and the bore acting on the front. Oscillating swash plate type variable capacity configured to adjust the discharge capacity by changing the reciprocating stroke of the piston by changing the inclination angle of the swash plate by the differential pressure with the pressure In the compressor, a swash plate tilt angle compulsory change mechanism for changing the tilt angle of the swash plate from an operating position to a non-operating position, and urging the swash plate held at the non-operating position to the non-operating position during rotation. A swash plate tilt angle hydraulic pressure return mechanism including an oil supply pump for returning the tilt angle of the swash plate from the non-operation position to the operation position using lubricating oil stored in the crank chamber; When the refrigerant gas blown into the crank chamber from the working chamber in the cylinder bore through the outer peripheral gap of the piston is interposed in the middle of a bleed passage that guides the refrigerant gas to the suction chamber, and the temperature inside the compressor is detected and the detected temperature is lower than the set temperature. An oscillating swash plate type variable displacement compressor including a temperature-sensitive control valve that reduces the opening of the bleed passage and increases the opening of the bleed passage when the opening is high.