JP2001349278A - Control valve for variable displacement compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control valve for a variable displacement compressor having smaller size, power saving ability and improved heat radiating performance. SOLUTION: A solenoid 3, a diaphragm 2 and a valve body 1 having a valve element 5 are arranged in sequence. Ports connected to the variable displacement compressor are located in the order of a port 9 communicated with a suction chamber for receiving a suction pressure Ps, a port 10 communicated with a discharge chamber for introducing a discharge pressure Pd and a port 11 communicated with a crank room to guide a pressure Pc in the crank room to the outside, in a view from the side of the solenoid 3. With the discharge pressure Pd introduced between the valve element 5 and a shaft 6 integrally molded, the valve element 5 is not affected by the discharge pressure Pd, achieving the smaller size and power saving ability of a spring 24 for the solenoid 3 for controlling the valve element 5 and an electromagnetic coil 19. The heat radiating performance is improved by the arrangement of the low-temperature port 9 for the suction pressure Ps in proximity to the solenoid 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control valve for a variable displacement compressor, and more particularly to a refrigerant gas provided in a variable displacement compressor for compressing low-temperature and low-pressure refrigerant gas in a refrigeration cycle of a vehicle air conditioner. The present invention relates to a control valve for external variable control for controlling the capacity of a motor.

[0002]

2. Description of the Related Art In a vehicle air conditioner, since the number of revolutions of an engine as a power source is not constant, the control of the refrigerating capacity according to the load is generally performed by making the capacity of a compressor variable. .

FIG. 2 is a schematic diagram showing the configuration of a conventional variable displacement compressor. In the variable displacement compressor 100, a driving force is transmitted from an output shaft of an engine to a pulley 101 via a clutch and a belt, and a shaft 103 of a crank chamber 102 is provided.
Drive. The shaft 103 is provided with a swash plate 104 with a variable inclination angle. Around the axis of the shaft 103, a plurality of pistons 105 that convert the rotational movement of the swash plate 104 into a reciprocating movement are arranged.
Each is connected to a suction chamber 107 and a discharge chamber 108 by a relief valve 106. The discharge chamber 108 is piped to return to the suction chamber 107 via the condenser 109, the receiver 110, the expansion valve 111, and the evaporator 112, and forms a refrigeration cycle.

[0004] The variable displacement compressor 100 also has a control valve 113 which can be externally controlled. This control valve 113
Is connected to the discharge chamber 108 such that the distal end thereof receives the discharge pressure Pd via the strainer 114.
A ball valve 115 urged in a valve closing direction by a spring is disposed in a valve chamber receiving the discharge pressure Pd. The downstream side of the ball valve 115 is connected so as to communicate with the crank chamber 102, and introduces the pressure controlled by the ball valve 115 into the crank chamber 102, and
2 is set to a crank chamber pressure Pc for controlling the angle of the swash plate 104. The ball valve 115 is in contact with a diaphragm 117, which is a pressure-sensitive member, via an operating rod 116.
The valve opening is adjusted by the movement of the diaphragm 117. The diaphragm 117 includes a ball valve 115.
Side chamber is communicated with the suction chamber 107 and the suction pressure P
s. Also, the crank chamber 102
Between the pipe leading to the suction chamber and the pipe leading to the suction chamber 107,
An orifice 118 is provided for releasing the pressure Pc in the crank chamber when the ball valve 115 is fully closed.

[0005] The control valve 113 also has a diaphragm 117.
And a solenoid that can change the operation set value of the ball valve 115 through the solenoid valve. The solenoid includes an electromagnetic coil 119, a core 120 as a fixed iron core, a plunger 121 as a movable iron core, a shaft 122 inserted through the core 120, and a diaphragm 117 via the shaft 122 and the plunger 121. Spring 1 to urge
23 and a sleeve 124 for guiding the plunger 121
And

Here, during operation of the variable displacement compressor 100, the high discharge pressure Pd of the discharge chamber 108 is controlled by the ball valve 1
15 is introduced into the valve chamber in which it is arranged, while the suction chamber 107
Is detected by the diaphragm 117, and the ball valve 115 is driven according to the suction pressure Ps. The ball valve 115 is driven by the diaphragm 117 receiving the suction pressure Ps. When the driving force is larger than the spring force urging the ball valve 115 in the valve closing direction, the ball valve 115 opens and the controlled pressure is increased. Is the crankcase 10
2 is introduced. The crank chamber pressure Pc is received by the piston 105 and controls the inclination angle of the swash plate 104.

For example, when the suction pressure Ps decreases, the force by which the diaphragm 117 drives the ball valve 115 increases, and the opening of the ball valve 115 increases. As a result, the pressure Pc in the crank chamber increases, which acts to increase the inclination angle of the swash plate 104. As a result, the stroke of the piston 105 is shortened, and the discharge capacity is reduced. When the discharge capacity decreases, a change occurs in the suction pressure Ps, which also controls the opening of the ball valve 115, further controls the pressure Pc in the crank chamber, and controls the inclination angle of the swash plate 104.

At this time, the diaphragm 117 receives the load of the spring 123 via the shaft 122 and the plunger 121.
19 can be freely changed by changing the current flowing therethrough. That is, when the current is increased, the force with which the plunger 121 is attracted to the core 120 is increased, so that the ball valve 115 is easily opened. When the current is reduced, the ball valve 115 is hardly opened.

[0009]

However, in the conventional control valve, since the ball valve is affected by a high pressure, the setting of the spring of the solenoid and the electromagnetic coil must be correspondingly large in size and the power must be increased. There was a problem.

[0010] Although the amount of heat generated by the solenoid increases due to the increase in power, the control valve is installed in an engine room under a relatively high temperature environment, so that there is a problem that heat dissipation must be considered. Was.

The present invention has been made in view of the above points, and provides a control valve for a variable displacement compressor having a solenoid having a reduced size of a spring and an electromagnetic coil and having reduced power consumption, and having improved heat radiation. The purpose is to do.

[0012]

According to the present invention, in order to solve the above-mentioned problem, a pressure-sensitive member which communicates with a suction chamber of a variable displacement compressor and operates in accordance with a suction pressure of a refrigerant drawn into the suction chamber is provided. The upstream side communicates with the discharge chamber that discharges the compressed refrigerant, receives the discharge pressure of the discharged refrigerant, and the downstream side communicates with the crank chamber, and controls the pressure controlled in accordance with the operation of the pressure-sensitive member. A control valve for a variable displacement compressor, comprising: a valve element introduced into the crank chamber; and a solenoid abutting on the pressure element to control an operation set value of the valve element. And the valve element is arranged on the same axis in this order, and a port connected to the variable displacement compressor is connected from the pressure sensing member side to a first port communicating with the suction chamber and the discharge chamber. The second port and Control valve, characterized in that located in the order of the third port in communication with the serial crank chamber is provided.

According to such a control valve for a variable displacement compressor, since the second port communicating with the discharge chamber is located at the center, the high pressure introduced into the second port is not controlled by the valve. Pressure is received in both the body side and the pressure-sensitive member side. Thus, the control of the valve element does not depend on the magnitude of the introduced pressure, so that the spring load and the electromagnetic force for urging the valve element can be reduced, and the solenoid can be downsized. Further, since the first port communicating with the suction chamber receiving the low-temperature and low-pressure refrigerant is located on the side closer to the solenoid, heat generated by the solenoid is absorbed on the first port side. It is a control valve for a variable displacement compressor with a good configuration and arrangement.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view showing a control valve for a variable displacement compressor according to the present invention.

The control valve for the variable displacement compressor includes a valve body 1
, A diaphragm 2 forming a pressure-sensitive member, and a solenoid 3. The valve body 1 includes a body 4 and
A valve element 5 disposed at an axial position of the body 4 so as to be able to advance and retreat.
And a shaft 6, a spring 7 for urging the valve element 5 in the valve closing direction, and an adjusting screw 8 for receiving the spring and adjusting the spring force. The body 4 is provided on the side of the diaphragm 2 with a port 9 communicating with the suction chamber of the variable displacement compressor and receiving the suction pressure Ps. At the center, the port 4 is communicated with the discharge chamber of the variable displacement compressor to introduce the discharge pressure Pd. A port 11 is provided at the front end thereof and is connected to the crank chamber of the variable displacement compressor to derive the pressure Pc in the crank chamber. An O-ring 12 as a seal member is provided on an outer peripheral portion between the port 9 and the port 10 of the body 4, and an O-ring 13 is provided on an outer peripheral portion between the port 10 and the port 11. Further, a strainer 14 is attached to the port 10 to which the discharge pressure Pd is introduced so as to cover the port 10.

The valve element 5 and the shaft 6 are integrally formed, and the connecting portion thereof is reduced in diameter to form a chamber communicating with the port 10 through which the discharge pressure Pd is introduced. In the illustrated example, the shaft 6 is provided with three grooves 15 on its outer peripheral surface, and through a gap formed between the shaft 6 and the inner wall surface of the body 4 that guides the shaft 6, a high discharge pressure Pd
A fluid seal is provided to provide resistance to the refrigerant flowing in the axial direction from the port 10 through which the fluid is introduced to the port 9 that receives the low suction pressure Ps. Also, this shaft 6
, A seal ring 16 is fitted into a groove provided on the outer peripheral surface thereof to form another fluid seal. In the present embodiment, a double fluid seal is provided by the plurality of grooves 15 and the seal ring 16, but only one of them may be provided. With this fluid seal, the amount of refrigerant leakage from the port 10 to the port 9 can be reduced, and a decrease in the maximum discharge capacity of the variable displacement compressor can be minimized.

The strainer 14 has a frusto-conical shape,
The inner diameter on the smaller diameter side is larger than the outer shape of the O-ring 13, and the outer diameter on the larger diameter side is smaller than the outer shape of the O-ring 12. Thereby, the strainer 14 does not interfere with the O-ring 13 on the port 11 side of the body 4,
It can be inserted from the port 11 side and attached to the port 10 where the high discharge pressure Pd is introduced. By forming the strainer mounting portion of the body 4 into a tapered shape corresponding to the inner peripheral surfaces at both ends in the axial direction of the strainer 14, the adhesion of the strainer 14 to the body 4 is increased, and the filtration performance of the strainer 14 is improved. be able to.

Further, the valve body 1 has the port 9 for communicating the low-temperature refrigerant to the diaphragm chamber partitioned by the diaphragm 2 located closest to the solenoid 3, so that the heat generated by the solenoid 3 is transferred to the port 9 The heat can be absorbed on the side, and the heat dissipation can be improved.

The diaphragm 2 is clamped by disks 17 and 18 arranged on both sides thereof, and the disk 17 is in contact with the end of the shaft 6. Solenoid 3
Are axially supported by an electromagnetic coil 19, a core 20 as a fixed iron core, a plunger 21 as a movable iron core, a cap 22, and a bearing formed on the core 20 and the cap 22 so as to be able to advance and retreat in the axial direction. And a spring 24 for urging the plunger 21 held by the shaft 23 so as to press the shaft 23 against the disk 18.

Here, during operation of the variable displacement compressor, a high discharge pressure Pd from the discharge chamber is introduced into the port 10. This high discharge pressure Pd is introduced into the space formed by the reduced diameter connection between the valve element 5 and the shaft 6 and is received by the valve element 5 and the shaft 6. In this case, the axial movement of the valve element 5 and the shaft 6 is canceled.
Since the valve body 5 does not receive a load in the axial direction depending on the magnitude of the pressure to be introduced, there is no need to consider the influence of high pressure on the setting of the spring 24 of the solenoid 3 and the electromagnetic force.
A small solenoid with small spring force and electromagnetic force can be used.

[0021]

As described above, according to the present invention, the solenoid, the pressure sensing member, and the valve element are arranged in this order, and the position of the port connected to the variable displacement compressor is communicated with the suction chamber when viewed from the side of the solenoid. Then, a port for receiving the suction pressure Ps and communicating with the discharge chamber to introduce the discharge pressure Pd and a port for communicating with the crank chamber to derive the pressure Pc in the crank chamber are arranged in this order. Since the port for introducing the discharge pressure Pd is located at the center, the valve body is not affected by the discharge pressure Pd.
Even if d changes, stable control characteristics can be obtained.
Further, since the valve body is not affected by the discharge pressure Pd, the size of the solenoid spring and the electromagnetic coil can be reduced, and power saving can be achieved. Further, due to the system, the low suction pressure P
Since the port of s and the solenoid are close to each other, heat dissipation can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a control valve for a variable displacement compressor according to the present invention.

FIG. 2 is a schematic diagram showing a configuration of a conventional variable displacement compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve main body part 2 Diaphragm 3 Solenoid 4 Body 5 Valve body 6 Shaft 7 Spring 8 Adjustment screw 9, 10, 11 Port 12, 13 O-ring 14 Strainer 15 Groove 16 Seal ring 17, 18 Disk 19 Electromagnetic coil 20 Core 21 Plunger 22 Cap 23 Shaft 24 Spring Pc Crank chamber pressure Pd Discharge pressure Ps Suction pressure

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Koji Hanyu, Inventor 1212-4, Nukuda-cho, Hachioji-shi, Tokyo Tokyo 72 Co., Ltd. 72) Inventor Hideki Takakubo 1211-4 Nukuda-cho, Hachioji-shi, Tokyo F-term in TDK Corporation (reference) 3H045 AA04 AA12 AA27 BA14 BA37 CA02 CA03 CA13 DA25 EA33 EA42 3H076 AA07 BB04 BB32 CC12 CC16 CC17 CC20 CC84 CC85 CC94 CC95

Claims (7)

[Claims] 1. A pressure-sensitive member, which communicates with a suction chamber of a variable displacement compressor and operates in accordance with a suction pressure of refrigerant sucked into the suction chamber, communicates with a discharge chamber which discharges compressed refrigerant on an upstream side. A valve body that receives the discharge pressure of the discharged refrigerant and communicates with the crank chamber on the downstream side and that introduces a pressure controlled according to the operation of the pressure-sensitive member into the crank chamber; A control valve for a variable displacement compressor having a solenoid that is in contact with and controls an operation set value of the valve element, wherein the solenoid, the pressure-sensitive member, and the valve element are arranged on the same axis in this order, and A port connected to the variable displacement compressor is a first port communicating with the suction chamber, a second port communicating with the discharge chamber, and a third port communicating with the crank chamber from the pressure sensing member side. Located in order Control valve according to claim Rukoto. 2. The valve body according to claim 1, wherein the valve body is inserted and arranged on the same axis between the valve body and the pressure-sensitive member, and is integrally formed with a transmission member to which the operation of the pressure-sensitive member is transmitted. The control valve for a variable displacement compressor according to claim 1. 3. The transmission member, wherein a plurality of grooves are provided around a holding portion between the first port and the second port which is held so as to be able to advance and retreat in an axial direction. Item 3. A control valve for a variable displacement compressor according to Item 2. 4. A groove is provided on a holding portion between the first port and the second port which is held so as to be able to advance and retreat in the axial direction, and a seal member is fitted in the groove. The control valve for a variable displacement compressor according to claim 2, wherein the control valve is provided. 5. The transmission member includes a first groove in which a seal member is fitted in a holding portion between the first port and the second port which is held so as to be able to advance and retreat in an axial direction. 3. The control valve for a variable displacement compressor according to claim 2, wherein said groove is provided in a circumferential direction. 6. An inner diameter larger than an outer shape of a first seal member fitted to an outer peripheral portion between said second port and a third port of a body containing said valve body and said transmission member. A strainer having an outer diameter smaller than an outer diameter of a second seal member fitted to an outer peripheral portion between the first port and the second port of the body so as to cover the second port. 3. The device according to claim 2, wherein
6. The control valve for a variable displacement compressor according to any one of items 5 to 5. 7. The frusto-conical shape wherein the body has an outer diameter reduced from the first port to the third port, and the strainer is attachable to the second port from the third port side. The control valve for a variable displacement compressor according to claim 6, wherein the control valve has a shape.