KR20110072487A - Variable displacement compressor - Google Patents

Abstract

PURPOSE: A variable-capacity compressor is provided to prevent backflow of ejected refrigerant by closing the first refrigerant inlet with the first valve body when swash plate is operated in minimum inclination angle. CONSTITUTION: The variable capacity compressor includes a check valve(100). The check valve includes: a valve housing(110); a valve body(120); a cover(130); and a joining member(140). The valve housing has the first refrigerant inlet(111) and refrigerant outlet(112). The pressure of ejection chamber is applied on the first refrigerant inlet. The end part of the valve housing facing the refrigerant inlet is opened. The valve body opens and closes the first refrigerant inlet. The pressure (Pc,Ps) of the crank chamber or the suction chamber actuates on the second refrigerant inlet(131) of cover. The cover covers the opened end part of the valve housing. The help subtitle is interposed between cover and valve body.

Description

Variable displacement compressors {VARIABLE DISPLACEMENT COMPRESSOR}

The present invention relates to a variable displacement compressor, and more particularly to a variable displacement compressor having a check valve for preventing the back flow of the discharge pressure.

Since the compressor included in the cooling system of the automotive air conditioner is directly connected to the engine through the belt, the rotation speed cannot be controlled.

Therefore, in recent years, a variable capacity compressor that can change the discharge amount of the refrigerant to obtain a cooling capacity without being regulated by the rotational speed of the engine has been used a lot.

Various types of variable displacement compressors are disclosed, such as swash plate type, rotary type and scroll type.

In the swash plate type compressor, the swash plate provided so that the inclination angle is variable in the crank chamber rotates according to the rotational motion of the rotating shaft, and the piston reciprocates by the rotational motion of the swash plate. In this case, the refrigerant in the suction chamber is sucked into the cylinder by the reciprocating motion of the piston, compressed and discharged to the discharge chamber. The inclination angle of the swash plate is changed according to the pressure difference in the crank chamber and the pressure in the suction chamber, and the discharge amount of the refrigerant is Will be controlled.

In particular, it is common to adopt the solenoid type capacity control valve to adjust the pressure of the crankcase by opening and closing the valve by energization, and thereby adjusting the discharge capacity by adjusting the inclination angle of the swash plate.

At this time, the operation of the capacity control valve is calculated by a control unit in which a signal such as the detected engine speed, the temperature inside or outside the vehicle, the evaporator temperature, or the like is incorporated by the CPU, and based on the result of the calculation, the current By sending it to an electromagnetic coil.

In addition, a check valve is provided at the discharge port communicating with the discharge chamber to prevent the backflow of the refrigerant during the minimum capacity operation of the compressor.

Hereinafter, a structure of a check valve according to the related art will be described with reference to the drawings.

1 is a longitudinal sectional view showing a check valve of a variable displacement compressor according to the prior art.

As shown in FIG. 1, the check valve 1 according to the related art includes a first refrigerant inlet 2a through which the discharge chamber pressure Pd acts, and a refrigerant outlet connected to the first refrigerant inlet 2a. 2b), a valve housing 2 having an end portion opposed to the first refrigerant inlet 2a, and a valve body 3 for opening and closing the first refrigerant inlet 2a, and a crank chamber or suction A second refrigerant inlet 4a through which the seal pressures Pc and Ps act is formed and covers the open end of the valve housing 2 and between the cover 4 and the valve body 3. And an intervening spring 5.

At this time, the valve body 3 acts on the discharge chamber pressure (Pd) in the upper portion and the crank chamber or suction chamber pressure (Pc, Ps) acts in the lower portion.

That is, the valve body 3 closes the first refrigerant inlet 2a by adding crank chamber or suction chamber pressures Pc and Ps to the elastic force of the spring 5.

The check valve 1 configured as described above is installed at the discharge port of the compressor to prevent the reverse flow of the refrigerant during the minimum capacity operation (at low pressure discharge).

 However, according to the conventional check valve 1, the differential pressure between the discharge chamber pressure Pd and the crank chamber or suction chamber pressures Pc and Ps during the minimum capacity operation of the compressor (compressor OFF) is Likewise, the pressure rises above the set pressure.

That is, the valve body 3 does not close the first refrigerant inlet 2a due to the differential pressure, so that the discharged refrigerant of the next cooling cycle (condenser) flows back to the compressor.

At this time, the discharged refrigerant flowed back to the swash plate chamber through the check valve (1) and the control valve has a problem that the durability of the swash plate is lowered due to the rapid flow sound and the crank chamber pressure increase by the flow of the counter flow refrigerant.

The present invention has been made to solve the above-mentioned conventional problems, an object of the present invention is to configure the check valve to be closed by the pressure of the backflow refrigerant discharged during the minimum inclination angle of the swash plate to prevent the backflow of the discharged refrigerant The present invention provides a variable displacement compressor.

In the variable displacement compressor of the present invention for achieving the above object, in a variable displacement compressor in which a suction chamber, a discharge chamber and a crank chamber are formed, the discharge chamber pressure is connected to the first refrigerant inlet and the refrigerant inlet A valve housing having a refrigerant outlet formed therein, the valve housing having an open end facing the first refrigerant inlet; A valve body for opening and closing the first refrigerant inlet; A cover for forming a second refrigerant inlet through which the crank chamber or suction chamber pressure is applied and covering the open end of the valve housing; And a check additive disposed between the cover and the valve body, wherein the valve body comprises: a first valve body for opening and closing the first refrigerant inlet and a second corresponding to the second refrigerant inlet; It is characterized by consisting of a valve body.

On the other hand, it is preferable that the first valve body is formed with a hydraulic pressure portion to which the discharged backflow refrigerant acts, and the second valve body is formed with a support portion inserted into the hydraulic pressure portion.

In addition, the discharge passage is connected to the discharge chamber is preferably provided with the check valve is further provided.

In addition, the crank chamber or the suction chamber is preferably provided with a connection passage for connecting the check valve.

According to the variable-capacity compressor according to the present invention, the reverse flow refrigerant discharged from the hydraulic portion of the first valve body acts during the minimum inclination of the swash plate to close the first refrigerant inlet to prevent the reverse flow of the discharge refrigerant. It works.

Accordingly, the reverse flow of the discharge refrigerant is blocked to prevent the durability of the swash plate due to the rapid flow sound and the crankcase pressure increase due to the refrigerant flow.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the structure of the variable displacement swash plate compressor provided with a valve assembly according to the present invention will be described schematically.

Figure 2 is a longitudinal sectional view showing a structure of a variable displacement compressor according to the present invention, Figure 3 is a side sectional view showing a rear housing of the variable displacement compressor of Figure 2, Figure 4 shows a structure of a check valve according to the present invention Longitudinal section.

As shown, the variable displacement swash plate compressor (C) includes a cylinder block (10) having a plurality of cylinder bores (12) formed parallel to the inner circumferential surface in the longitudinal direction, and in front of the cylinder block (10). The front housing 16 is hermetically coupled, and the rear housing 18 hermetically coupled via a valve plate 20 at the rear of the cylinder block 10.

The crank chamber 86 is provided inside the front housing 16, and one end of the drive shaft 44 is rotatably supported near the center of the front housing 16, while the other end of the drive shaft 44 is Passed through the crank chamber 86 is supported via a bearing provided in the cylinder block 10.

In the crank chamber 86, the lug plate 54 and the swash plate 50 are provided around the drive shaft 44.

In the lug plate 54, a pair of power transmission support arms 62 each having a linearly perforated guide hole 64 formed at the center thereof are formed to protrude integrally on one surface, and one surface of the swash plate 50 has a ball. As the lug plate 54 rotates, the ball 66 of the swash plate 50 slides in the guide hole 64 of the lug plate 54 so that the swash plate 50 can be rotated. The inclination angle is variable.

In addition, the outer circumferential surface of the swash plate 50 is fitted to the piston 14 so as to be able to slide through the shoe 76.

Accordingly, as the swash plate 50 rotates in an inclined state, the pistons 14 fitted through the shoe 76 on the outer circumferential surface thereof are reciprocated in each cylinder bore 12 of the cylinder block 10. do.

In addition, a suction chamber 22 and a discharge chamber 24 are formed in the rear housing 18, and each cylinder bore is formed in the valve plate 20 interposed between the rear housing 18 and the cylinder block 10. The intake valve 32 and the discharge valve 36 are formed in the place corresponding to (12), respectively.

By the reciprocating motion of the piston 14, the refrigerant in the suction chamber 22 is sucked into the cylinder bore 12, compressed, and discharged to the discharge chamber 24. The pressure in the crank chamber 86 and the suction chamber ( 22) or the inclination angle of the swash plate 50 is changed in accordance with the pressure difference in the discharge chamber 24 to adjust the discharge amount of the refrigerant, which adjusts the pressure of the crank chamber 86 by opening and closing the valve by energization. It is usually implemented by the capacity control valve 200 to adjust the inclination angle of the swash plate 50 to adjust the discharge capacity.

In addition, a discharge flow path 101 communicating with the discharge chamber 24 is formed in the rear housing 18. At this time, the discharge passage 101 is provided with a check valve 100 for discharging the refrigerant compressed above the set differential pressure to the outside (condenser) and at the same time to prevent the reverse flow of the discharged refrigerant.

In addition, the discharge port 25 is preferably formed on the discharge side of the discharge passage 101.

In addition, the rear housing 18 is formed with a connection passage 102 for connecting the pressures Pc and Ps of the crank chamber 86 or the suction chamber 22 to the check valve 100.

The compressor described above is just one example in which the check valve according to the present invention is installed, and is applicable to all other clutch-less displacement variable compressors.

Hereinafter, a check valve 100 according to the present invention will be described with reference to the drawings.

As shown, the discharge passage 101 is mounted in the discharge passage 101 and is formed by the differential pressure between the discharge chamber 24 pressure Pd and the crank chamber 86 or the suction chamber 22 pressures Pc and Ps. The check valve 100 according to the present invention for opening and closing the repetitively performing the action of sending the refrigerant discharged from the discharge chamber 24 to the next cooling cycle (condenser), largely the valve housing 110 and the A valve body 120 reciprocating inside the valve housing 110, a cover 130 covering the open end of the valve housing 120, and interposed between the cover 130 and the valve body 120. The biasing member 140 is included.

First, the valve housing 110 has a refrigerant connected to the refrigerant inlet 111 according to the reciprocating movement of the first refrigerant inlet 111 and the valve body 120 in which the discharge chamber 24 pressure Pd is applied. An outlet 112 is formed.

In this case, the first refrigerant inlet 111 is connected to the discharge chamber 24 by the discharge passage 101, and the refrigerant outlet 112 is connected to the discharge outlet 25 by the discharge passage 101. That is, the valve housing 110 is installed in the discharge passage 101.

In addition, the valve body 120 opens and closes the aforementioned first refrigerant inlet 111 by the pressure Pd of the discharge chamber 24. In addition, the valve body 120 has a reverse flow refrigerant discharged during the driving of the minimum inclination angle of the compressor, which will be described later.

In addition, the cover 130 is formed with a second refrigerant inlet 131 in which the crank chamber 86 or the suction chamber pressures Pc and Ps act. That is, the second refrigerant inlet 131 is connected to the connection passage 102.

On the other hand, the biasing member 140 is formed of a spring to apply an elastic force in the direction in which the valve body 120 closes the first refrigerant inlet 111.

The biasing member 140 may adjust the pressure difference of opening and closing the valve body 120 according to the size of the elastic modulus.

In addition, the valve body 120 includes a first valve body 121 that opens and closes the first refrigerant inlet 111, and a second valve body 122 corresponding to the second refrigerant inlet 112. The first and second valve bodies 121 and 122 are separately configured to move, respectively.

On the other hand, the biasing member 140 preferably applies an elastic force to the first valve body 121.

In addition, the first valve body 121 is formed with a pressure receiving portion 121a to which discharged backflow refrigerant acts, and the second valve body 122 has a support portion 122a inserted into the hydraulic pressure portion 121a. A) is formed.

That is, the check valve 100 of the present invention prevents the reverse flow of the discharged refrigerant even when the differential pressure is increased as shown in [Table 1] during the driving of the minimum inclination angle of the compressor due to the action of the reverse flow refrigerant discharged to the hydraulic unit 121a. do.

According to the check valve 100 of the present invention configured as described above, the first valve body 121 by the reverse flow refrigerant discharged to the hydraulic pressure portion 121a of the first valve body 121 when the swash plate 50 is driven at the minimum inclination angle. ) Closes the first refrigerant inlet 111 to prevent backflow of the discharged refrigerant.

At this time, the elastic force of the biasing member 140 also acts on the first valve body 121.

Accordingly, the reverse flow of the discharged refrigerant is blocked to prevent the durability of the swash plate 50 due to the rapid flow sound and the increase in the pressure of the crank chamber 86 due to the refrigerant flow.

That is, the differential pressure is higher than the above-described [Table 1] and the set pressure by the action of the reverse flow refrigerant discharged to the second valve body 122 and the first valve body 121 and the hydraulic pressure unit 121a reciprocating respectively. In this case, the reverse flow of the discharged refrigerant is completely blocked.

Subsequently, when the set differential pressure is lowered, the crank chamber 86 or the suction chamber 22 pressures Pc and Ps are transmitted to the second refrigerant inlet 131 to act on the lower portion of the second valve body 122. The second valve body 122, which receives the pressure Pc and Ps of the suction chamber 22, rises, and the support part 122a supports the lower part of the hydraulic pressure part 121a so that the first refrigerant inlet 111 ) Will remain closed.

That is, the pressure Pc, Ps of the crank chamber 86 or the suction chamber 22 rises at the time of driving the minimum inclination angle of the swash plate 50, and the pressure Cc of the raised crank chamber 86 or the suction chamber 22 is increased. Ps) is to act on the check valve 100 through the connection flow path (102). At this time, in use of the compressor, the crankcase pressure Pc and the suction chamber pressure Ps become approximately equal.

On the other hand, (a) of FIG. 4 shows that the valve body 120 compresses the biasing member 140 by the discharge chamber 24 pressure Pd, and then cools the compressed refrigerant by opening the first refrigerant inlet 111. The discharge (FULL OPEN) to the cycle (condenser), Figure 4 (b) is the reverse flow refrigerant discharged to the water pressure portion (121a) of the first valve sleeve 121 when driven at the minimum inclination angle of the swash plate 50 It acts to raise only the first valve body 121 to close the first refrigerant inlet 111 (BACK FLOW CLOSE) to prevent the backflow of the refrigerant. 4 (c) shows that the crank chamber 86 or the suction chamber 22 pressures Pc and Ps act on the second valve body 122 so that the support portion 122a of the second valve body 122 is connected to the first valve. By supporting the pressure receiving portion 121a of the sieve 121 to close the first refrigerant inlet 111 to prevent the backflow of the refrigerant.

As mentioned above, although preferred embodiment of this invention was described in detail, the technical scope of this invention is not limited to the above-mentioned embodiment, It should be interpreted by the claim. It will be understood by those skilled in the art that many modifications and variations are possible without departing from the scope of the present invention.

For example, it is not necessary to limit the installation position of the check valve 100 as described above, and the check valve 100 if the discharge chamber 24 pressure Pd and the crank chamber 86 pressure Pc can act. Note that the installation location of the can be changed in various ways.

1 is a longitudinal sectional view showing a check valve of a variable displacement compressor according to the prior art.

2 is a longitudinal sectional view showing the structure of a variable displacement compressor according to the present invention.

3 is a side cross-sectional view illustrating a rear housing of the variable displacement compressor of FIG. 2.

Figure 4 is a longitudinal sectional view showing the structure of a check valve according to the present invention.

* Description of symbols on main parts of the drawings *

100-check valve 110-valve housing

120-valve body 130-biased member

140-cover

Claims (4)

In a variable displacement compressor in which a suction chamber, a discharge chamber and a crank chamber are formed, A valve housing having a first coolant inlet to which the discharge chamber pressure acts and a coolant discharge port connected to the coolant inlet, and having an end portion opposed to the first coolant inlet; A valve body for opening and closing the first refrigerant inlet; A cover for forming a second refrigerant inlet through which the crank chamber or suction chamber pressure is applied and covering the open end of the valve housing; And It includes a check valve consisting of; a gas additive is interposed between the cover and the valve body, The valve body is a variable displacement compressor, characterized in that the first valve body for opening and closing the first refrigerant inlet and the second valve body corresponding to the second refrigerant inlet. The method of claim 1, The variable pressure compressor of claim 1, wherein the first valve body is formed with a hydraulic pressure portion to which the discharged backflow refrigerant acts, and the second valve body has a support portion inserted into the hydraulic pressure portion. The method according to claim 1 or 2, And a discharge flow passage connected to the discharge chamber and having the check valve installed therein. The method of claim 3, Capacitively variable compressor characterized in that the connection flow path for connecting the crank chamber or the suction chamber and the check valve.

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