JPH10153178A - Variable capacity compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out a cooling disabling operation without installing a big solenoid open/close valve on the suction passage of a refrigerant gas from an outer refrigerant circuit to a suction area. SOLUTION: A valve plate 14 is made by two layers structure by a main plate 31 formed a suction port 35 and a delivery port 37 and a rotary plate 32 arranged superimposedly and relative-turnably thereto. At the operation time by a minimum delivery capacity, the rotary plate 32 is relative-turned to the main plate 31 by the operation of a spool 40 and the suction port 35 or the delivery port 37 is closed and the suction or delivery of the refrigerant gas for a cylinder bore 12a is intercepted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement compressor used in, for example, a vehicle air conditioner, and more particularly to a variable displacement compressor that performs a cooling-disabled operation at a minimum capacity operation.

[0002]

2. Description of the Related Art As a conventional variable displacement compressor of this type, for example, a compressor disclosed in Japanese Patent Application Laid-Open No. 3-37378 is known. In this conventional configuration, an electromagnetic on-off valve is disposed in a suction passage for introducing refrigerant gas from an external refrigerant circuit to a suction area, and the electromagnetic on-off valve is opened and closed according to a change in discharge capacity. . Then, when the cam plate is shifted to the minimum tilt state and the operation with the minimum capacity is performed, the suction passage is closed by the electromagnetic on-off valve, and the introduction of the refrigerant gas from the external refrigerant circuit to the suction area is shut off. Thereby, the flow of the refrigerant gas in the external refrigerant circuit is stopped, and an operation in which cooling is impossible is performed.

[0003]

However, in this conventional variable displacement compressor, a suction passage having a large opening diameter is directly opened and closed by an electromagnetic on-off valve. For this reason, it is necessary to equip the on-off valve body and the solenoid of the electromagnetic on-off valve with a large one, and there is a problem that the whole structure of the compressor is complicated, large and heavy. Also,
There is a problem in that the power consumption is large when the solenoid is excited, and the load on other accessories such as a battery and an alternator increases.

The present invention has been made by paying attention to such problems existing in the conventional technology. The purpose is to enable the cooling-disabled operation without providing a large electromagnetic on-off valve in the suction passage of the refrigerant gas from the external refrigerant circuit to the suction area, to achieve a simple structure and light weight. It is an object of the present invention to provide a variable displacement compressor which can reduce the power consumption.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, the pressure of the crank chamber is reduced by changing the pressure of the control pressure chamber based on adjusting the opening of the displacement control valve. In a variable displacement compressor in which the difference between the pressure in the cylinder bore and the pressure through the piston is changed, and the inclination angle of the cam plate is changed in accordance with the difference to control the displacement, the main plate is provided in the housing. A rotary plate for rotating the rotary plate of the valve plate relative to the main plate to open and close a suction port or a discharge port. Things.

According to a second aspect of the present invention, in the variable displacement compressor according to the first aspect, the rotary plate is rotated relative to the main plate by the rotating means to open and close the suction port. It was done.

According to a third aspect of the present invention, in the variable displacement compressor according to the first or second aspect, the rotating means operates so as to relatively rotate the rotary plate of the valve plate during the operation of the minimum displacement. This is configured by a spool.

According to a fourth aspect of the present invention, in the variable displacement compressor according to the third aspect, the displacement control valve is disposed in the middle of an air supply passage communicating the discharge area with the control pressure chamber. When the operation at the minimum discharge capacity is performed by opening the capacity control valve, the pressure downstream of the capacity control valve in the air supply passage is guided to the back side of the spool to operate the spool, thereby rotating the rotary plate of the valve plate. The suction port or the discharge port is closed by relative rotation.

According to a fifth aspect of the present invention, in the variable displacement compressor according to the third aspect, an air supply passage communicating with the control pressure chamber and a discharge region and having a throttle portion in the middle thereof is provided. A capacity control valve is disposed in the middle of the bleed passage that connects the control pressure chamber and the suction area, and when operation of the minimum discharge capacity is performed by closing the capacity control valve, an upstream of the capacity control valve in the bleed passage is provided. By operating the spool by applying pressure to the rear side of the spool, the rotary plate of the valve plate is relatively rotated to close the suction port or the discharge port.

Therefore, in the variable displacement compressor according to the first aspect, when the drive shaft is rotated by an external drive source such as a vehicle engine, the piston reciprocates via the cam plate. Then, the compression of the refrigerant gas is performed with a discharge capacity corresponding to the inclination angle of the cam plate. Here, when the cam plate is shifted to the minimum inclination state, the stroke of the piston is minimized, and the compression operation is performed with the minimum displacement. Here, when the rotary plate of the valve plate is relatively rotated with respect to the main plate by the rotating means, the suction port or the discharge port is closed. Thereby, introduction of the refrigerant gas from the external refrigerant circuit to the suction area or outflow of the refrigerant gas from the discharge area to the external refrigerant circuit is blocked. Then, the flow of the refrigerant gas in the external refrigerant circuit is stopped, and an operation incapable of cooling is performed.

In the variable displacement compressor according to the present invention, when the suction port is closed, the pressure in the cylinder bore decreases, and the pressure difference between the piston and the crank chamber increases. Decrease.

In the variable displacement compressor according to the third aspect, during operation of the minimum displacement, the rotary plate of the valve plate is relatively rotated by the operation of the spool to close the suction port or the discharge port.

In the variable displacement compressor according to the present invention, the high-pressure refrigerant gas in the discharge region is supplied to the control pressure chamber with the opening of the displacement control valve disposed in the middle of the supply passage. The pressure in the control pressure chamber is increased. Based on the increase in the pressure in the control pressure chamber, the difference between the pressure in the crank chamber and the pressure in the cylinder bore via the piston is changed. And
When the difference becomes the maximum, the cam plate is arranged at the minimum tilt position, and the operation with the minimum displacement is performed. At this time, the high-pressure refrigerant gas in the discharge area is also supplied from the air supply passage to the back side of the spool, and the back pressure of the spool is increased. The spool is actuated by the increase of the back pressure, the rotary plate of the valve plate is relatively rotated, and the suction port or the discharge port is closed.

In the variable displacement compressor according to the fifth aspect, the extraction of the refrigerant gas from the control pressure chamber to the suction area is shut off with the closing of the displacement control valve disposed in the middle of the bleed passage. . In this state, a predetermined amount of high-pressure refrigerant gas is
The pressure is supplied from the discharge area into the control pressure chamber through the air supply passage having the throttle portion, and the pressure in the control pressure chamber is increased. Based on the increase in the pressure in the control pressure chamber, the difference between the pressure in the crank chamber and the pressure in the cylinder bore via the piston is changed. When the difference becomes maximum, the cam plate is arranged at the minimum tilt position, and the operation with the minimum discharge capacity is performed. At this time, the pressure in the control pressure chamber is also supplied to the back side of the spool, the spool is operated by the increase of the back pressure, the rotary plate of the valve plate is relatively rotated, and the suction port or the discharge port is closed. .

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, a front housing 11 forming a part of the housing is joined and fixed to a front part of a cylinder block 12 also forming a part of the housing. A rear housing 13, which also forms a part of the housing, is fixedly connected to a rear portion of the cylinder block 12 via a valve plate 14.

In the rear housing 13, there are formed a suction chamber 13a forming a suction area and a discharge chamber 13b forming a discharge area. The valve plate 14 is provided with a suction valve 14a and a discharge valve 14b.
The closed space formed by the front housing 11 and the cylinder block 12 is a crank chamber 15 which also serves as a control pressure chamber. A drive shaft 16 is rotatably supported by the front housing 11 and the cylinder block 12 via a pair of radial bearings 17 so as to penetrate through the crank chamber 15. The base end of the drive shaft 16 projects from the front housing 11 to the outside, and is always operatively connected to an external drive source such as a vehicle engine (not shown). That is, this compressor is a so-called clutchless type variable displacement compressor.

The rotary support 18 is provided with the drive shaft 16.
It is fixed to. Also, a swash plate 1 as a cam plate
9 is supported by a drive shaft 16 in a crank chamber 15 so as to be slidable and tiltable in the axial direction. The swash plate 19 is connected to the rotating support 18 via a hinge mechanism 20. The swash plate 19 is guided by its hinge mechanism 20 in sliding movement and tilting in the axial direction, and is rotated integrally with the drive shaft 16.

The maximum inclination angle of the swash plate 19 is determined by the stopper 19a provided on the swash plate 19 and the rotation support member 18.
Stipulated by the abutment. The minimum inclination angle of the swash plate 19 is determined by the circlip 16 attached to the drive shaft 16.
b and the swash plate 19 are in contact with each other.

A plurality of cylinder bores 12a are formed in the cylinder block 12. Single-headed piston 2
1 is a cylinder bore 12 in the head portion 21a.
a of the swash plate 19 is moored to the outer periphery of the swash plate 19 via a pair of shoes 22. The compression reaction force accompanying the compression operation of the piston 21 is received by the front housing 11 via the shoe 22, the swash plate 19, the hinge mechanism 20, the rotary support 18, and the thrust bearing 23.

The air supply passage 24 is formed so as to connect the discharge chamber 13b and the crank chamber 15. A capacity control valve 25 composed of an electromagnetic on-off valve is provided in the middle of the air supply passage 24 and includes a control valve element 26 and a solenoid 28 for opening and closing the control valve element 26 with respect to a control valve hole 27. ing. The solenoid 28 of the capacity control valve 25
Is excited, as shown in FIG.
6 is disposed at a position where the control valve hole 27 is closed. Also,
When the solenoid 28 of the capacity control valve 25 is demagnetized, as shown in FIG. 3, the control valve body 26 is arranged at a position where the control valve hole 27 is opened.

By controlling the opening and closing of the capacity control valve 25, the supply of the refrigerant gas guided from the discharge chamber 13b to the crank chamber 15 through the air supply passage 24 is adjusted. Then, the difference between the pressure in the crank chamber 15 acting before and after the piston 21 and the pressure in the cylinder bore 12a is adjusted. The inclination angle of the swash plate 19 is changed according to the difference, the stroke of the piston 21 is changed, and the discharge capacity is adjusted.

As shown in FIGS. 1 and 2, the bleed passage 29
Is formed so as to connect the crank chamber 15 and a suction port 35 described later. This bleed passage 29
An axial passage 16a formed at the center of the drive shaft 16,
It comprises an inside of a receiving recess 12b formed at the center of the rear end side of the cylinder block 12, a pressure release hole 14c formed at the center of the valve plate 14, and a plurality of pressure release grooves 14d formed at the valve plate 14. I have. Shaft passage 16a
The front end is opened to the crank chamber 15 near the radial bearing 17 on the front side. The pressure in the crank chamber 15 is extracted into each suction port 35 through the bleed passage 29.

Next, the structure of the valve plate 14 will be described in detail. As shown in FIGS. 1 and 2, the valve plate 14 includes a disc-shaped main plate 31 and a disc-shaped main plate 31 that is relatively rotatably disposed in a housing recess 31 a at the center of the rear surface of the main plate 31. Rotary plate 3
2 and valve forming plates 33 and 34 arranged on both sides of the main plate 31 in an overlapping manner. That is, the valve plate 14 has a configuration in which valve forming plates 33 and 34 are overlapped on both surfaces of a two-layer structure of a main plate 31 and a rotary plate 32.

A plurality of suction ports 35 correspond to the respective cylinder bores 12a,
1a is formed on the inner bottom portion and the valve forming plate 34 on the rear side. And, in the valve forming plate 33 on the front side,
The suction valve 14 corresponds to the suction port 35.
a is formed to be openable and closable.

A plurality of opening / closing holes 36 are provided for each of the suction ports 35.
Are formed on the rotary plate 32. When the rotary plate 32 is rotated to the open position shown in FIGS. 1 and 2, the opening / closing holes 36 match the suction ports 35, and the respective suction ports 35 are opened. When the rotary plate 32 is turned to the closed position shown in FIGS.
Are displaced from the suction ports 35, and each suction port 35 is closed.

As shown in FIGS. 1 and 2, a plurality of discharge ports 37 are formed on the main plate 31 and the valve forming plate 33 on the front side corresponding to each of the cylinder bores 12a. Then, the rear valve forming plate 34
The discharge valve 14 b is formed to be openable and closable so as to correspond to the discharge port 37. The retainer forming plate 38 is arranged on the rear side valve forming plate 34 in an overlapping manner, and a retainer 38a for regulating the open position thereof is formed in a portion corresponding to each discharge valve 14b.

The pressure relief groove 14d of the bleed passage 29 is formed to extend radially on the inner bottom surface of the housing recess 31a of the main plate 31 so as to be in contact with the rotary plate 32. The sliding contact surface between the housing recess 31a of the main plate 31 and the rotary plate 32 is lubricated by the lubricating oil in the refrigerant gas flowing along the pressure releasing grooves 14d.

The housing cylinder 39 is provided in the rear housing 13 and has a communication hole 39a formed at one end thereof so as to communicate with the air supply passage 24. The spool 40 constituting the rotating means is movably housed in the housing cylinder 39, and on the back side, the pressure downstream of the capacity control valve 25 in the air supply passage 24 is conducted through the communication hole 39a. Has been. The pressure in the air supply passage 24 acts on the spool 40 as back pressure. The spool 40 is connected to the rotary plate 3 of the valve plate 14 via the connecting pin 41.
2 is connected to the outer peripheral edge. The spring 42 is disposed in the housing cylinder 39 and urges the spool 40 toward the communication hole 39a.

Next, the operation of the variable displacement compressor of the first embodiment will be described. In this compressor, when the drive shaft 16 is rotated by an external drive source such as a vehicle engine, the swash plate 1 is rotated via a rotation support 18 and a hinge mechanism 20.
9 is rotated integrally. The rotational motion of the swash plate 19 is converted into a reciprocating linear motion of the piston 21 via the shoe 22,
The head 21 a of the piston 21 is connected to the cylinder bore 12.
It is reciprocated within a.

Here, when the cooling load is large, based on a command from an external control computer not shown in FIG.
And as shown in FIG. 2, the solenoid 28 is excited,
The control valve body 26 of the capacity control valve 25 is arranged at a closed position for closing the control valve hole 27, and the air supply passage 24 is shut off.

In this high cooling load state, the high-pressure compressed refrigerant gas in the discharge chamber 13b is not supplied to the rear surface of the spool 40 through the air supply passage 24, and no high back pressure acts on the spool 40. For this reason, the spool 40 is
The rotary plate 32 of the valve plate 14 is arranged at the open position of the suction port 35 by being moved to the original position by the urging force. In this state, the position of the suction port 35 of the main plate 31 and the position of the opening / closing hole 36 of the rotary plate 32 coincide with each other, so that refrigerant gas can be sucked from the suction chamber 13a into the cylinder bore 12a.

Then, by the return operation of the piston 21 from the top dead center position to the bottom dead center position, the refrigerant gas in the suction chamber 13a is sucked into the cylinder bore 12a while pushing the suction valve 14a through the suction port 35. Is done. With the suction of the refrigerant gas into the cylinder bore 12a, the refrigerant gas is guided from the external refrigerant circuit (not shown) into the suction chamber 13a. The refrigerant gas in the cylinder bore 12a is
After being compressed until a predetermined pressure is reached by the forward movement from the bottom dead center position to the top dead center position, the pressure is discharged to the discharge chamber 13b while pushing the discharge valve 14b through the discharge port 37. Then, the refrigerant gas in the discharge chamber 13b is supplied to an external refrigerant circuit (not shown), is provided for cooling in the vehicle compartment, and is returned to the compressor.

In this high cooling load state, the discharge chamber 1
3b is not supplied to the crank chamber 15 through the air supply passage 24, and the refrigerant gas in the crank chamber 15 is supplied to the axial passage 16a of the bleed passage 29, the accommodating recess 12b.
Of the suction chamber 13 through the pressure release hole 14c and the pressure release groove 14d.
a. Then, the pressure in the crank chamber 15 approaches the low pressure in the suction chamber 13a, that is, the suction pressure. In this state, the pressure of the refrigerant gas guided from the external refrigerant circuit to the suction chamber 13a is high, and the difference between the pressure in the crank chamber 15 and the pressure in the cylinder bore 12a via the piston 21 decreases. For this reason, the swash plate 19 is moved and held to the maximum tilt state, and the compression operation of the maximum discharge capacity is performed.

On the other hand, when the cooling load is small, the solenoid 28 is demagnetized as shown in FIGS. 3 and 4 based on a command from an external control computer (not shown). Then, the control valve body 26 of the capacity control valve 25 is arranged at an open position for opening the control valve hole 27, and the air supply passage 24 is opened.

In this low cooling load state, the high-pressure refrigerant gas in the discharge chamber 13b is supplied to the back of the spool 40 via the air supply passage 24, and a high back pressure acts on the spool 40. Therefore, the spool 40 is moved to the operating position side against the urging force of the spring 42. This movement of the spool 40 is transmitted to the rotary plate 32 of the valve plate 14 via the connection pin 41. And
When the rotary plate 32 is rotated to the closed position of the suction port 35, a displacement occurs between the suction port 35 of the main plate 31 and the opening / closing hole 36 of the rotary plate 32. Due to this displacement, the suction of the refrigerant gas from the suction chamber 13a into the cylinder bore 12a is shut off.

When the suction port 35 is closed and the suction of the refrigerant gas into the cylinder bore 12a is shut off, the refrigerant gas in the crank chamber 15 is guided to each suction port 35 through the bleed passage 29. Here, the bleed passage 29
Plays the role of a throttle passage, and the cylinder bore 12a
The amount of the refrigerant gas drawn into the cylinder bore 1 is limited.
The pressure in 2a decreases. For this reason, the piston 21 between the pressure in the crank chamber 15 and the pressure in the cylinder bore 12a
The difference through increases.

At the same time, in this low cooling load state,
The high-pressure refrigerant gas in the discharge chamber 13b is also supplied into the crank chamber 15 through the air supply passage 24, and the pressure in the crank chamber 15 is increased. In this state, the pressure of the refrigerant gas guided from the external refrigerant circuit to the suction chamber 13a is low, and the difference between the pressure in the crank chamber 15 and the pressure in the cylinder bore 12a via the piston 21 increases. Then, by these combinations, the swash plate 19 is quickly moved to the minimum inclination state side.

As described above, in this compressor, the capacity control valve 25 is opened and closed according to the cooling load. On the other hand, the suction pressure fluctuates according to the cooling load. The difference between the pressure in the crank chamber 15 and the pressure in the cylinder bore via the piston 21 is changed based on the opening / closing of the capacity control valve 25 and the fluctuation of the suction pressure. For this reason,
The inclination angle of the swash plate 19 is changed, the reciprocating stroke of the piston 21 is adjusted, and the displacement of the compressor is adjusted.
Thereby, the suction of the refrigerant gas from the external refrigerant circuit is stopped, and the flow of the refrigerant gas in the external refrigerant circuit is stopped,
The refrigeration circuit enters an operation state in which cooling is impossible.

When the swash plate 19 is located at the minimum inclination position, the rotary plate 32 of the valve plate 14 is rotated to the closed position of the suction port 35 as described above. Thus, the suction of the refrigerant gas from the suction chamber 13a into the cylinder bore 12 is blocked.

Here, the minimum inclination angle of the swash plate 19 is set to be slightly larger than 0 degrees. Therefore, even when the swash plate 19 is arranged at the minimum tilt position, the piston 21 continues to reciprocate with the minimum stroke, and the discharge of the compressed refrigerant gas from the cylinder bore 12a to the discharge chamber 13b is continued. The refrigerant gas discharged into the discharge chamber 13b flows into the crank chamber 15 through the air supply passage 24, and flows out of the crank chamber 15 into the axial passage 16a of the bleed passage 29, the storage recess 12b, and the like. It is guided to each suction port 35 through the pressure hole 14c and the pressure release groove 14d, and is sucked into the cylinder bore 12a again.

That is, when the swash plate 19 is disposed at the minimum tilt position, the refrigerant gas passes through the internal circulation passage including the air supply passage 24, the bleed passage 29, and the suction port 35 inside the compressor, and the cylinder bore 12a And the discharge chamber 13 b and the crank chamber 15. And
With the internal circulation of the refrigerant gas, the inside of the compressor is lubricated by the lubricating oil contained in the refrigerant gas.

Further, when the compression operation is performed in a state where the swash plate 19 is disposed at the minimum inclination position as described above and the cooling load increases, as shown in FIGS.
8 is excited, the capacity control valve 25 is closed, and the air supply passage 2 is closed.
4 is closed again. As a result, the compressed refrigerant gas in the discharge chamber 13b is not supplied to the rear side of the spool 40 in the housing cylinder 39 and the crank chamber 15 through the air supply passage 24.

In this state, the refrigerant gas in the crank chamber 15 is discharged into the suction port 35 exclusively through the bleed passage 29. Therefore, the pressure in the crank chamber 15 is gradually reduced. Then, the crank chamber 15 and the cylinder bore 1
The difference from 2a via the piston 21 is reduced, and the swash plate 19 is moved from the minimum tilt position to the maximum tilt position.

In this state, the pressure on the back side of the spool 40 is also released to the crank chamber 15 through the air supply passage 24 and then to the suction port 35. Therefore, the back pressure of the spool 40 is reduced, and the spool 40 is moved from the operating position to the original position by the urging force of the spring 42. And
The rotary plate 32 of the valve plate 14 is again turned to the open position of the suction port 35. For this reason,
The suction of the refrigerant gas from the suction chamber 13a into the cylinder bore 12a becomes possible again, and the suction of the refrigerant gas from the external refrigerant circuit into the compressor is restarted. Thereby, the flow of the refrigerant gas in the external refrigerant circuit is restarted, and the refrigeration circuit enters a cooling operation state.

The effects that can be expected from the first embodiment will be described below. (A) In the variable displacement compressor of the first embodiment, during operation of the minimum displacement, the rotation of the rotary plate 32 of the valve plate 14 closes the suction port 35, and causes the refrigerant gas to flow into the cylinder bore 12a. Is blocked. For this reason, the circulation of the refrigerant gas in the external refrigerant circuit can be interrupted without providing a large electromagnetic on-off valve in the refrigerant gas suction passage from the external refrigerant circuit to the suction area, and the cooling operation is turned on and off. Can be switched. Therefore, the structure of the variable displacement compressor can be simplified, and the weight can be reduced.

When the intake port 35 is closed, the cylinder bore 1
The pressure in 2a decreases, and the pressure difference between the piston 2 and the crank chamber 15 increases. For this reason, switching from the large displacement operation to the small displacement operation becomes quick, which is effective, for example, in displacement control during vehicle acceleration.

(B) In the variable displacement compressor of the first embodiment, the rotary plate 32 of the valve plate 14 is rotated by the operation of the spool 40 as a rotating means during the operation of the minimum displacement. The suction port 35 is closed. Therefore, the structure of the rotating means is simple, and the rotary plate 32 of the valve plate 14 can be reliably rotated to the open position or the closed position of the suction port 35.

(C) In the variable displacement compressor according to the first embodiment, the high-pressure refrigerant gas in the discharge chamber 13b is released from the crank chamber by opening the capacity control valve 25 disposed in the middle of the air supply passage 24. 15 and to the rear side of the spool 40 in the storage cylinder 39. Therefore, the pressure in the crank chamber 15 and the back pressure in the spool 40 can be increased quickly and reliably. Accordingly, the swash plate 19 is arranged at the minimum inclination position in accordance with the fluctuation of the cooling load, and the operation can be promptly and reliably shifted to the operation with the minimum discharge capacity.
Further, when the operation state is switched to the operation state with the minimum discharge capacity, the flow of the refrigerant gas in the external refrigerant circuit can be quickly and reliably shut off.

(D) In the variable displacement compressor of the first embodiment, the discharge capacity is reduced by combining the above-described supply of the discharge pressure into the crank chamber 15 and the closing of the suction port 35. It has become. Therefore, the difference between the pressure in the crank chamber 15 and the pressure in the cylinder bore 12a via the piston 21 can be increased more quickly. Therefore, switching from the large discharge capacity operation to the small discharge capacity operation can be further speeded up. Also,
During operation at the minimum discharge capacity, a large pressure difference can be set between the crank chamber 15 and the cylinder bore 12a, and operation at the minimum discharge capacity is stably maintained. Further, during the minimum capacity operation, the cylinder bore 12a, the discharge chamber 1
3b, an internal circulation passage including the air supply passage 24, the crank chamber 15, the bleed passage 29, and the suction port 35 is formed. The supply of the lubricating oil to the sliding portion in the compressor is ensured by the refrigerant gas flowing in the internal circulation passage.

(E) In the variable displacement compressor of the first embodiment, the small-diameter supply passage 24 need only be opened and closed by the displacement control valve 25 to operate the spool 40. Therefore, the size of the control valve body 26 of the displacement control valve 25 and the solenoid 28 for moving the control valve body 26 can be reduced. Therefore, the power consumption of the solenoid 28 can be greatly reduced, and the load on other engine accessories such as a battery and an alternator can be significantly reduced.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
This embodiment will be described focusing on the differences from the first embodiment.

In the second embodiment, as shown in FIGS. 5 and 6, the crank chamber 15 and the suction chamber 13
a is formed between the bleed passage 45 and the bleed passage 45.
A capacity control valve 46 composed of an electromagnetic opening / closing valve is provided in the middle of the process. The displacement control valve 46 includes a control valve element 47 and a solenoid 49 for opening and closing the control valve element 47 with respect to the control valve hole 48. When the solenoid 49 of the capacity control valve 46 is excited, as shown in FIG. 5, the control valve body 47 is disposed at a position where the control valve hole 48 is opened. The solenoid 49 of the capacity control valve 46
Is demagnetized as shown in FIG.
7 is disposed at a position where the control valve hole 48 is closed.

By controlling the opening and closing of the capacity control valve 46, the extraction of the refrigerant gas guided from the crank chamber 15 to the suction chamber 13a via the bleed passage 45 is adjusted. Then, the difference between the pressure in the crank chamber 15 acting before and after the piston 21 and the pressure in the cylinder bore 12a is adjusted. The inclination angle of the swash plate 19 is changed according to the difference, the stroke of the piston 21 is changed, and the discharge capacity is adjusted.

Also in the second embodiment, the valve plate 14 is formed so as to have a two-layer structure of the main plate 31 and the rotary plate 32, as in the first embodiment. Further, on the back side of the spool 40 as a rotating means housed in the housing cylinder 39,
The pressure upstream of the capacity control valve 46 in the bleed passage 45 is
9a. And the bleed passage 45
The internal pressure acts on the spool 40 as a back pressure.

Next, the operation of the variable displacement compressor according to the second embodiment will be described. When the cooling load is large, the capacity control valve 46 is excited as shown in FIG.
The control valve element 47 of the capacity control valve 46 is disposed at an open position for opening the control valve hole 48, and the bleed passage 45 is opened.

In this state, the refrigerant gas in the housing cylinder 39 on the rear side of the spool 40 flows out into the suction chamber 13a via the bleed passage 45, and no high back pressure acts on the spool 40. For this reason, the spool 40 is moved to the original position by the urging force of the spring 42, and the valve plate 1
The fourth rotary plate 32 is arranged at an open position of the suction port 35. In this state, the position of the suction port 35 of the main plate 31 and the position of the opening / closing hole 36 of the rotary plate 32 coincide with each other, so that refrigerant gas can be sucked from the suction chamber 13a into the cylinder bore 12a. That is, an external refrigerant circuit (not shown)
Thus, the refrigerant gas can be sucked into a, and the refrigeration circuit enters the cooling operation state.

In this high cooling load state, the piston 21 and the cylinder bore 12
The blow-by gas flows into the crank chamber 15 also serving as a control pressure chamber through a gap between the blow-by gas and the pressure chamber. Here, the gap communicates the control pressure chamber with the discharge region and forms an air supply passage having a throttle portion in the middle thereof. On the other hand, the refrigerant gas in the crank chamber 15 flows out to the suction chamber 13a via the bleed passage 45. For this reason, the crankcase 1
The increase in the pressure in the crank chamber 15 is suppressed, and the difference between the pressure in the crank chamber 15 and the pressure in the cylinder bore 12a via the piston 21 is reduced. For this reason, the swash plate 19 is moved and held to the maximum tilt state, and the compression operation of the maximum discharge capacity is performed.

On the other hand, when the cooling load is small, as shown in FIG. 6, the solenoid 49 is demagnetized and the control valve body 47 of the displacement control valve 46 is arranged at the closed position for closing the control valve hole 48. The bleed passage 45 is closed.

Also in this state, the blow-by gas flows into the crank chamber 15 through the gap between the piston 21 and the cylinder bore 12a as the piston 21 reciprocates. On the other hand, since the bleed passage 45 is shut off, the discharge of the refrigerant gas from the crank chamber 15 into the suction chamber 13a is stopped. Therefore, the pressure in the crank chamber 15 is increased, and the difference between the pressure in the crank chamber 15 and the pressure in the cylinder bore 12a via the piston 21 increases. Therefore, the swash plate 19 is moved and held to the minimum tilt state, and the compression operation with the minimum discharge capacity is performed.

In this low cooling load state, since the bleed passage 45 is closed, the storage cylinder 3 on the back side of the spool 40
The extraction of the refrigerant gas in 9 into the suction chamber 13a is stopped. On the other hand, since the pressure in the crank chamber 15 is increased, the high pressure acts on the back surface of the spool 40 via the bleed passage 45 and the communication hole 39a. For this reason, the spool 40 is moved to the operating position against the urging force of the spring 42 and the rotary plate 3 of the valve plate 14 is moved.
2 is arranged at the closed position of the suction port 35. Then, as in the first embodiment, the suction of the refrigerant gas from the external refrigerant circuit (not shown) into the suction chamber 13a is disabled, and the refrigeration circuit is in an operation state in which cooling is impossible.

Further, when the compression operation is performed in a state where the swash plate 19 is arranged at the minimum inclination angle and the cooling load increases, as shown in FIG. Is opened, and the bleed passage 45 is opened again. Thereby, the storage cylinder 39 on the back side of the spool 40 is
The refrigerant gas inside and in the crank chamber 15 is discharged to the suction chamber 13a via the bleed passage 45. Therefore, the pressure in the crank chamber 15 is gradually reduced. Then, the difference between the crank chamber 15 and the cylinder bore 12a via the piston 21 becomes small, and the swash plate 19 is moved and arranged from the minimum tilt position to the maximum tilt position. The back pressure of the spool 40 also decreases, and is moved from the operating position to the original position by the urging force of the spring 42. Then, the rotary plate 32 of the valve plate 14 is pivotally disposed again at the open position of the suction port 35, the flow of the refrigerant gas in the external refrigerant circuit is restarted, and the refrigeration circuit enters a cooling operation state.

The effects that can be expected from the second embodiment will be described below. (F) In the variable capacity compressor according to the second embodiment, substantially the same effects as those of the items (a) and (b) of the first embodiment are exhibited.

(G) In the variable displacement compressor of the second embodiment, the displacement control valve 46 disposed in the middle of the bleed passage 45 is closed, and the pressure in the crank chamber 15 is increased by the inflow of blow-by gas. Can be Then, the increased pressure of the crank chamber 15 is supplied to the back side of the spool 40 in the housing cylinder 39 via the bleed passage 45. For this reason, the pressure of the crank chamber 15 and the back pressure of the spool 40 are suppressed from rising rapidly. Therefore, each sliding portion in the compressor is not exposed to a sudden pressure increase, and the durability thereof can be improved.

(H) In the variable displacement compressor according to the second embodiment, to operate the spool 40, it is only necessary to open and close the small-diameter bleed passage 45 with the displacement control valve 46. Therefore, the control valve body 47 of the capacity control valve 46 and the solenoid 49 for moving the control valve body 47 can be downsized. Therefore, the power consumption of the solenoid 49 can be greatly reduced, and the load on other engine accessories such as a battery and an alternator can be significantly reduced.

The present invention can be embodied with the following modifications. (1) In the second embodiment, a pressure supply passage having a predetermined throttle amount is provided between the discharge chamber 13b and the crank chamber 15 so as to communicate with each other.

In such a configuration, a predetermined amount of high-pressure compressed refrigerant gas is always supplied from the discharge chamber 13b into the crank chamber 15 through the pressure supply passage in addition to the blow-by gas. Thereby, when the displacement control valve 46 is closed, the speed of increasing the pressure in the crank chamber 15 and the back pressure of the spool 40 can be increased. Therefore, the movement arrangement of the swash plate 19 to the minimum inclination position and the closing of the suction port 35 by the rotary plate 32 can be made quicker.

(2) Instead of the spring 42 in the storage tube 39, the back surface of the spool 40 and the storage tube 3 facing the back surface
A tension spring is interposed between the spool 40 and the inner wall surface of the spool 9 to urge the spool 40 toward the communication hole 39a.

With such a configuration, the related configuration of the housing cylinder 39 and the spool 40 can be reduced in size.
(3) The present invention is embodied in a variable displacement compressor with a clutch.

With this configuration, for example, the clutch is disengaged only when an air conditioner operation switch (not shown) is off, and the same operation as that of the clutchless variable displacement compressor is performed when the air conditioner operation switch is on. If so, the number of times of clutch engagement / disconnection can be drastically reduced, and traveling feeling can be improved.

(4) In the first embodiment, a branch path is provided in the air supply passage 24 downstream of the capacity control valve 25.
The rear side of the spool 40 in the housing cylinder 39 is connected to the air supply passage 24 via the branch passage without forming a part of the air supply passage 24.

(5) In the second embodiment, a branch passage is provided in the bleed passage 45 on the upstream side of the capacity control valve 46.
The rear side of the spool 40 in the housing cylinder 39 is connected to the air supply passage 46 via the branch passage without forming a part of the bleed passage 46.

In the case of such a configuration, the air supply passage 2
4 or the degree of freedom in the arrangement of the bleed passage 45 and the arrangement of the housing cylinder 39 are improved. (6) An opening / closing hole 36 is formed on the rotary plate 32 of the valve plate 14 so as to correspond to the discharge port 37 of the main plate 31, and when the rotary plate 32 of the valve plate 14 rotates during the operation with the minimum capacity. The discharge port 37 is configured to be closed.

(7) The control pressure chamber is provided independently of the crank chamber 15, and the pressure in the control chamber is changed to change the pressure in the crank chamber 15 accommodating the swash plate 19 and the pressure in the cylinder bore 11a. And the inclination angle of the swash plate 19 is changed in accordance with the difference.

Even with such a configuration, substantially the same operation and effects as those of the above embodiments can be exerted.

[0076]

The present invention is configured as described above, and has the following effects. According to the first aspect of the present invention, the cooling-disabled operation can be performed without providing a large electromagnetic on-off valve in the suction passage of the refrigerant gas from the external refrigerant circuit to the suction area, and the structure of the compressor is achieved. However, the weight can be reduced simply.

According to the second aspect of the present invention, it is possible to quickly switch the operation from the large discharge capacity to the small discharge capacity. According to the third aspect of the present invention, the configuration of the rotating means is simple, and the rotary plate of the valve plate can be reliably rotated to the open / close position of the suction port or the discharge port.

According to the fourth aspect of the present invention, the spool is operated in conjunction with the opening / closing operation of the air supply passage by the capacity control valve, and the rotary plate of the valve plate is moved to the open position or the closed position of the suction port. Can be quickly and reliably rotated.

In order to operate the spool, it is only necessary to open and close the small-diameter supply passage with a small capacity control valve, so that the power consumption of the solenoid can be greatly reduced. Therefore, the load on other engine accessories such as a battery and an alternator can be significantly reduced.

According to the fifth aspect of the present invention, by operating the spool in conjunction with the opening / closing operation of the bleed passage by the capacity control valve, it is possible to avoid an abrupt increase in pressure in the compressor. The durability of each sliding portion can be improved.

In order to operate the spool, it is only necessary to open and close the small-diameter bleed passage with a small capacity control valve, so that the power consumption of the solenoid can be greatly reduced. Therefore, the load on other engine accessories such as a battery and an alternator can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a variable displacement compressor according to a first embodiment.

FIG. 2 is a sectional view taken along line 2-2 in FIG. 1;

FIG. 3 is a sectional view showing a minimum displacement state of the variable displacement compressor of FIG. 1;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a sectional view showing a variable displacement compressor according to a second embodiment.

FIG. 6 is a sectional view showing a minimum displacement state of the variable displacement compressor of FIG. 5;

[Explanation of symbols]

11: a front housing forming part of the housing; 12: a cylinder block forming part of the housing; 12a ... a cylinder bore; 13 ... a rear housing forming part of the housing; 13a: a suction chamber forming a suction area; 13b: a discharge chamber constituting a discharge area, 14: a valve plate, 15: a crank chamber also serving as a control pressure chamber, 1
6 drive shaft, 19 swash plate as cam plate,
21: piston, 24: air supply passage, 25, 46: capacity control valve, 29, 45: bleed passage, 31: main plate,
32: a rotary plate, 35: a suction port, 37: a discharge port, 40: a spool constituting a rotating means.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shintaro Miura 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation

Claims (5)

[Claims] 1. A control pressure chamber and a crank chamber are formed inside a housing and a drive shaft is rotatably supported. A cylinder block forming a part of the housing is formed with a cylinder bore, and a piston is formed in the cylinder bore. Is reciprocally accommodated, a cam plate is supported on the drive shaft so as to be integrally rotatable and tiltable in the crank chamber, and the pressure in the control pressure chamber is changed based on adjustment of the opening of the displacement control valve. The difference between the pressure in the crank chamber and the pressure in the cylinder bore through the piston is changed based on the change in the pressure in the chamber, and the displacement of the cam plate is controlled by changing the inclination angle of the cam plate according to the difference. In the variable displacement compressor, a valve plate having a two-layer structure of a main plate and a rotary plate is disposed in the housing. The rotary plate lube plate pivoted relative to the main plate, a variable displacement compressor provided with a rotating means for opening and closing the suction port or discharge port. 2. The variable displacement compressor according to claim 1, wherein the rotary means rotates the rotary plate relative to the main plate to open and close a suction port. 3. The variable displacement compressor according to claim 1, wherein the rotating means is a spool that operates to relatively rotate a rotary plate of the valve plate during operation with a minimum displacement. 4. The valve according to claim 1, wherein the displacement control valve is disposed in the middle of an air supply passage communicating the discharge area with the control pressure chamber. 4. The suction port or the discharge port is closed by operating the spool by guiding the pressure downstream of the capacity control valve in the air passage to the rear side of the spool to relatively rotate the rotary plate of the valve plate. A variable capacity compressor according to item 1. 5. An air supply passage communicating with the control pressure chamber and the discharge region and having a throttle portion in the middle thereof, and the capacity control valve is provided in the middle of a bleed passage communicating the control pressure chamber and the suction region. When the operation of the minimum discharge capacity is performed by closing the capacity control valve, the pressure upstream of the capacity control valve in the bleed passage is guided to the back side of the spool to operate the spool, so that the valve plate is closed. The variable displacement compressor according to claim 3, wherein the rotary plate is relatively rotated to close the suction port or the discharge port.