KR101617830B1 - Control valve for a variable displacement compressor - Google Patents

Abstract

A control valve for a variable displacement compressor, which uses a plurality of reciprocating pistons coupled to a swash plate disposed in a crank chamber to discharge refrigerant sucked from a suction chamber into a discharge chamber, When the capacity type compressor is in the first capacity operating range, the flow rate of the first control refrigerant sucked from the crank chamber through the first intermediate pressure port and discharged to the suction chamber through the low pressure port is increased to reduce the pressure in the crank chamber And a valve unit for increasing the operating capacity of the variable displacement compressor by increasing the inclination angle of the swash plate when the variable displacement compressor is in the first displacement operation range, Thereby reducing the second control refrigerant flow rate that is sucked through the first intermediate pressure port and discharged to the crank chamber through the second intermediate pressure port Thereby increasing the operating capacity of the variable capacity compressor by increasing the inclination angle of the swash plate by decreasing the pressure of the crank chamber, and the high-pressure port, the first intermediate-pressure port, and the second intermediate- Pressure port is formed at a lower portion of the body, and a first communication hole and a bypass hole are formed between the first intermediate pressure port and the low-pressure port in the body, A needle moving linearly along the communication hole; And a sleeve coupled to the needle for controlling the degree of opening of the first communication hole, wherein the bypass hole is maintained in a fully opened state, and the valve portion controls the degree of opening of the first communication hole, And the first control refrigerant flow rate is varied.
Therefore, since the pressure in the crank chamber can be easily controlled through the adjustment of the first control refrigerant, rapid capacity control of the variable capacity compressor is possible. Furthermore, since the flow rate of the first control refrigerant can be maintained at a small value, unnecessary discharge of the refrigerant into the suction chamber is reduced. From this, the efficiency of the control valve increases and the power consumption decreases.

Description

[0001] The present invention relates to a control valve for a variable displacement compressor,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control valve for a variable capacity compressor, and more particularly, to a control valve for a variable capacity compressor in which capacity of a variable capacity compressor is rapidly controlled and performance of the variable capacity compressor is improved.

A swash plate type compressor is widely used as a compressor of a car air conditioner. The swash plate type compressor is divided into various types according to the compression type and structure. Recently, variable capacity type compressors capable of varying the compression capacity have been widely used.

In the variable capacity type compressor, the inclination degree of the swash plate is adjusted to adjust the capacity of the variable capacity type compressor. That is, when the inflow amount of refrigerant from the discharge chamber to the crank chamber of the variable capacity compressor is increased, the pressure of the crank chamber is increased to decrease the inclination of the swash plate, so that the capacity of the variable capacity compressor is reduced.

However, there is a problem that it is difficult to quickly control the capacity of the variable displacement compressor only by adjusting the flow rate of the refrigerant between the discharge chamber and the crank chamber. In addition, conventionally, the communication hole is completely opened between the crank chamber and the suction chamber, so that the refrigerant flows into the suction chamber from the crank chamber. That is, since a part of the refrigerant introduced from the discharge chamber flows into the suction chamber through the crank chamber, a large amount of refrigerant has to flow into the crank chamber from the discharge chamber for controlling the pressure in the crank chamber. Accordingly, since the refrigerant in the discharge chamber has a result of being bypassed to the suction chamber, the efficiency of the compressor is reduced and the coefficient of performance of the air conditioner equipped with the compressor is lowered. Particularly, since the communication hole is formed on the basis of the maximum capacity of the variable capacity compressor, there is a problem that an excessive amount of refrigerant flows out to the suction chamber.

It is an object of the present invention to provide a control valve for a variable capacity compressor in which the capacity of the variable capacity compressor can be rapidly controlled and the performance of the variable capacity compressor is improved.

A control valve for a variable displacement compressor, which uses a plurality of reciprocating pistons coupled to a swash plate disposed in a crank chamber to discharge refrigerant sucked from a suction chamber into a discharge chamber, When the capacity type compressor is in the first capacity operating range, the flow rate of the first control refrigerant sucked from the crank chamber through the first intermediate pressure port and discharged to the suction chamber through the low pressure port is increased to reduce the pressure in the crank chamber And a valve unit for increasing the operating capacity of the variable displacement compressor by increasing the inclination angle of the swash plate when the variable displacement compressor is in the first displacement operation range, Thereby reducing the second control refrigerant flow rate that is sucked through the first intermediate pressure port and discharged to the crank chamber through the second intermediate pressure port Thereby increasing the operating capacity of the variable capacity compressor by increasing the inclination angle of the swash plate by decreasing the pressure of the crank chamber, and the high-pressure port, the first intermediate-pressure port, and the second intermediate- Pressure port is formed at a lower portion of the body, and a first communication hole and a bypass hole are formed between the first intermediate pressure port and the low-pressure port in the body, A needle moving linearly along the communication hole; And a sleeve coupled to the needle for controlling the degree of opening of the first communication hole, wherein the bypass hole is maintained in a fully opened state, and the valve portion controls the degree of opening of the first communication hole, And the first control refrigerant flow rate is varied.

According to another aspect of the present invention, there is provided a variable displacement compressor for compressing refrigerant sucked from a suction chamber using a plurality of pistons coupled to a swash plate disposed in a crankcase and reciprocating, The first and second intermediate pressure ports communicating with the crank chamber and the high pressure port communicating with the discharge chamber are spaced apart from each other and communicated with the suction chamber, A lower pressure port formed at a lower portion thereof and having a through hole formed in a vertical direction; A valve portion including a needle inserted in the through hole and linearly movable in the up and down direction, and a sleeve coupled to a lower portion of the needle; And a solenoid for applying an operating force for linearly moving the needle in a vertical direction, wherein a first communication hole is defined between the first intermediate pressure port and the low pressure port by the through hole, The second communication hole is defined between the intermediate pressure ports, and when the variable capacity type compressor is in the first capacity operation range, the sleeve decreases the opening degree of the first communication hole while the needle is lowered by the solenoid , The stepped portion formed on the needle decreases the opening degree of the second communication hole to increase the operating capacity of the variable capacity compressor by reducing the pressure of the crank chamber and increasing the inclination angle of the swash plate, A bypass hole communicating between the first intermediate pressure port and the low pressure port, In is formed, and provides at full capacity operating range of the variable capacity compressor control valve for a variable capacity compressor, it characterized in that the control chamber, the suction refrigerant flowing from the crank chamber.

The control valve for a variable capacity compressor of the present invention has the following effects.

First, since the pressure inside the crank chamber can be easily controlled through the adjustment of the first control refrigerant from the crank chamber to the suction chamber, rapid capacity control of the variable capacity compressor is possible.

Secondly, since the flow rate of the first control refrigerant can be maintained at a small value, unnecessary discharge of refrigerant into the suction chamber is reduced. Therefore, the efficiency of the control valve increases and the power consumption decreases. In addition, the coefficient of performance of the compressor in which the control valve is installed is improved.

1 is a partial cross-sectional view showing an internal structure of a control valve according to an embodiment of the present invention.
2 is a graph showing a relationship between a flow area of the first control refrigerant and a flow area of the second control refrigerant with respect to a current value applied to the solenoid shown in FIG.
FIG. 3 is a schematic view showing an open state of the first communication hole, the second communication hole, and the bypass hole shown in FIG. 1 in the minimum capacity operation of the compressor provided with the control valve shown in FIG.
FIG. 4 is a schematic view showing an open state of the first communication hole, the second communication hole, and the bypass hole shown in FIG. 1 in the maximum capacity operation of the compressor provided with the control valve shown in FIG.
5 is a partial cross-sectional view showing an internal structure of a control valve according to a comparative example.
6 is a partial cross-sectional view showing an internal structure of a control valve according to another embodiment of the present invention.

FIG. 1 is a schematic partial cross-sectional view showing an internal structure of a control valve (hereinafter referred to as a "control valve") 100 for a variable capacity compressor according to an embodiment of the present invention. The variable displacement compressor (hereinafter referred to as "compressor") (not shown) includes a plurality of pistons (not shown) coupled to a swash plate (not shown) disposed in the crank chamber, After the sucked refrigerant is pressurized, it is discharged to the discharge chamber. The structure of the compressor can be variously selected, for example, in Patent No. 529716, No. 515285, No. 572123, and the like.

The control valve 100 includes a body 110, a valve unit 120, and a solenoid 130. The body 110 is formed in the through hole 115 along the vertical direction. The first intermediate pressure port 111, the second intermediate pressure port 112 and the high pressure port 113 are formed along the upper direction from the lower side of the side surface of the body 110. The high pressure port 113 communicates with the discharge chamber and the first and second intermediate pressure ports 111 and 112 communicate with the crank chamber. A lower pressure port 114 is formed in the lower portion of the body 110 to communicate with the suction chamber. The first communication hole 141 is formed between the first intermediate pressure port 111 and the low pressure port 114 so that the crank chamber and the suction chamber communicate with each other. The second communication hole 142 is formed between the high pressure port 113 and the second intermediate pressure port 112 so that the discharge chamber and the crank chamber communicate with each other.

A bypass hole 145 is formed in the body 110 to communicate between the first intermediate pressure port 111 and the low pressure port 113. Since the bypass hole 145 is maintained in the fully opened state, the bypass hole 145 functions as a fixed communicating area. In the present embodiment, one bypass hole 145 is formed, but the present invention is not limited thereto.

The valve portion 120 includes a needle 121 and a sleeve 122. The needle 121 is inserted into the through hole 115 and linearly moves in the vertical direction. The sleeve 122 is inserted into the lower portion of the needle 111 and moves up and down together with the needle 111. The sleeve 112 is disposed below the first communication hole 141 and controls the opening degree of the first communication hole 141 as it moves upward. The first communication hole 141 is formed to have a larger radius as it goes downward. The sleeve 122 is formed so as to be oblique on the side so as to correspond to the first communication hole 141. Therefore, the risk of the sleeve 122 passing through the first communication hole 141 and escaping to the upper portion is eliminated, and the opening degree of the first communication hole 141 can be easily adjusted. Accordingly, the first communication hole 141 functions as a variable communication area.

The needle 121 is formed with a stepped portion 121a so that the radius of the portion of the needle 121 located in the second communication hole 142 is smaller than the peripheral portion. The step portion 121a varies the opening degree of the second communication hole 142 by the upward and downward movement of the needle 121. [

The solenoid 130 applies an operating force to the needle 121 to linearly move the needle 121 in the vertical direction. The solenoid 130 includes a housing 133, a core 134, a coil 135, a plunger 136, a first spring 131, and a second spring 132. The core 134 is fixed within the housing 133 and surrounds the needle 121. The core 134 guides the needle 121 to linearly move in the up-and-down direction. The coil 135 is fixed to the housing 133 so as to surround the core 134. The plunger 136 is fixed to the upper portion of the needle 121 and moves up and down together with the needle 121.

The first spring 131 is fixed between the plunger 136 and the upper inner surface of the housing 133 to exert a first elastic force to push the plunger 136 downward. The second spring 132 is disposed between the core 134 and the plunger 136 to apply a second elastic force to push the plunger 136 upward. The second elastic force is designed to be larger than the first elastic force. Therefore, when the current value applied to the solenoid 130 is less than the set value, the plunger 136 can not move downward. Accordingly, the downward movement of the needle 121 is also limited, and the first communication hole 141 is kept closed by the sleeve 122. [

The operation of the control valve 100 will be described in detail with reference to FIG. 2 is a graph showing a relationship between a flow area of a first control refrigerant (hereinafter referred to as a "first flow area") f2 and a flow area of a second control refrigerant 2 flow area ") f1. Here, the first control refrigerant refers to a refrigerant that is sucked from the crank chamber through the first intermediate pressure port 111 and discharged to the suction chamber through the low pressure port 114, and the first flow area (f2) is a sum of the area through which the first control refrigerant can pass through the first communication hole 141 and the area of the bypass hole 145. [ The second control refrigerant refers to a refrigerant sucked from the discharge chamber through the high pressure port 113 and discharged to the crank chamber through the second intermediate pressure port 112. The second flow area f1 Is an area through which the second control refrigerant can pass through the second communication hole 142.

Wherein the compressor is largely divided into a first capacity operation range and a second capacity operation range, wherein the first capacity operation range is from a specific capacity of the compressor to a maximum capacity operation, From the minimum capacity operation to the specific capacity. The specific capacity may be a fixed value, but in the present embodiment, the specific capacity is determined by a spring constant of the first spring 131, a spring constant of the second spring 132, a pressure of the discharge chamber, Pressure, the pressure of the suction chamber, and the like.

3 is a schematic view showing an open state of the first communication hole 141, the second communication hole 142, and the bypass hole 145 at the time of the minimum capacity operation of the compressor. As described above, since the second elastic force is greater than the first elastic force, the downward movement of the needle 121 is restricted, the first communication hole 141 is maintained at the maximum open state, The communication hole 142 is kept closed by the sleeve 122. However, since the bypass hole 145 is completely opened regardless of the movement of the needle 121, the minimum first control refrigerant flow rate flows out of the crank chamber into the suction chamber.

As described above, the bypass hole 145 is completely opened at the minimum capacity operation of the compressor, so that the first control refrigerant flows into the suction chamber from the crank chamber. In a minimum capacity operation of the compressor, the inclination angle of the swash plate is about 2 degrees or less. Even in this case, a very small amount of refrigerant is compressed. However, if the compressor has a clutchless structure, a discharge check valve (not shown) is installed so that the compressor operates during the minimum capacity operation but the refrigerant is not discharged to the condenser. The discharge check valve is designed to open only when the pressure difference between the front and rear of the valve becomes equal to or greater than a set value. Accordingly, at the time of the minimum capacity operation, the flow rate of the refrigerant flowing into the front end of the discharge check valve is small, the pressure difference is not large, and the discharge check valve is not opened. However, when the flow path between the crank chamber and the suction chamber is completely closed, the pressure of the discharge chamber continuously rises (the inflow of the refrigerant flowing into the crank chamber from the discharge chamber must be restricted) And the discharge to the condenser occurs. This is not a preferable operating condition and also causes a problem that the oil that has flowed out of the control valve is not circulated again. Therefore, in this embodiment, the bypass hole 145 is always kept open to suppress the pressure rise in the discharge chamber.

The needle 121 is kept stationary by a difference between the second elastic force and the first elastic force until the current value applied to the solenoid 130 reaches a specific current value. Therefore, in the second capacity operation range, the first flow area and the second flow area each have a specific constant value.

If the current value applied to the solenoid 130 is greater than or equal to the specific current value (the first capacity operating range), the plunger 136 overcomes the difference between the second elastic force and the first elastic force and moves downward . The needle 121 moves downward together with the plunger 136. From this, the first communication hole 141 is partially opened, and the second communication hole 142 is partially closed. At this time, the bypass hole 145 is completely opened regardless of the movement of the needle 121. Therefore, when the current value increases in the first capacity operating range, the degree of opening of the first communication hole 141 increases and the degree of opening of the second communication hole 142 decreases. Thus, the first flow area has a tendency to increase and the second flow area has a tendency to decrease.

If the current value reaches the maximum current value, the first communication hole 141 is completely opened, and the second communication hole 142 is completely closed by the step 121a. At this time, the compressor performs the maximum capacity operation. 4 is a schematic view showing an open state of the first communication hole 141, the second communication hole 142, and the bypass hole 145 when the compressor is operated at the maximum capacity. Even if the current value exceeds the maximum current value, the needle 121 can not be further moved downward by the step 121a.

In the first capacity operation range, when the current value increases, the first flow area increases to increase the flow rate of the first control refrigerant, the second flow area decreases, and the flow rate of the second control refrigerant decreases do. That is, as the current value increases, the flow rate of the high-pressure refrigerant flowing into the crank chamber from the discharge chamber decreases, and the flow rate of the medium-pressure refrigerant flowing into the suction chamber from the crank chamber increases, do. Therefore, the inclination of the swash plate increases, thereby increasing the operating capacity of the compressor. From the above, in order to increase the operating capacity of the compressor, the current value may be increased to increase the first flow area and decrease the second flow area.

Referring again to FIG. 2, the first and second flow areas f1, f2, g1 and g2 of the control valve 100 according to the present embodiment and the control valve 10 according to the comparative example are compared. In Fig. 2, the solid lines f1 and f2 are data in this embodiment, and the dotted lines g1 and g2 are data in the comparative example. 5 is a schematic partial cross-sectional view of a control valve 10 according to a comparative example. The comparative example is different from the present embodiment in that there is no first intermediate pressure port 111 and low pressure port 114 of the present embodiment and there is no sleeve 122 and bypass hole 145 due to this. However, a bypass hole is formed between the crank chamber and the suction chamber to maintain a fully opened state, so that the refrigerant flows into the suction chamber from the crank chamber.

In the control valve 10 of the comparative example, the first flow area g2 has a specific constant value in the entire capacity operation range. That is, since the first flow area f2 of the present embodiment can be kept smaller than the first flow area g2 of the comparative example in the entire section, the flow rate of the refrigerant flowing into the suction chamber through the crank chamber from the discharge chamber . Therefore, the efficiency of the control valve 100 is increased, and the power consumption is reduced. Further, in the case of the air conditioner in which the control valve 100 is installed, the coefficient of performance is improved.

Further, in the control valve 10 of the comparative example, since the pressure control of the crank chamber is performed by adjusting the second flow area g1 in the first capacity operation range, the pressure control of the crank chamber is performed quickly it's difficult. However, in the present embodiment, since the crankcase pressure control is performed in combination with the second flow area f1 as well as the first flow area f2, the pressure control of the crank chamber is performed quickly . Therefore, it is possible to quickly adjust the capacity of the air conditioner provided with the control valve, thereby improving the satisfaction of the user.

6 is a partial cross-sectional view showing the internal structure of the control valve 200 according to another embodiment of the present invention. 6, the same reference numerals as those in the above-described embodiment denote the same members. Hereinafter, differences from the above-described embodiment will be mainly described.

In the above-described embodiment, the bypass hole 145 is formed in the body 110. However, in this embodiment, the bypass hole 145 of the above-described embodiment is not formed in the body 210, and a bypass portion (not shown) for directly connecting the crank chamber and the suction chamber is formed. The bypass unit (not shown) maintains a fully opened state, and the refrigerant flows into the suction chamber from the crank chamber. The control valve 200 controls the flow rate of the first control refrigerant flowing from the crank chamber to the suction chamber by adjusting the opening degree of the first communication hole 141 according to the operation capacity of the compressor. Accordingly, since the flow rate of the first control refrigerant flowing from the crank chamber to the suction chamber can be controlled by the bypass portion (not shown) and the control valve 200, the pressure in the crank chamber can be controlled, The capacity of the compressor can be adjusted.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100, 200: control valve for variable capacity type compressor
110: Body 111: First intermediate pressure port
112: second intermediate pressure port 113: high pressure port
114: Low pressure port 115: Through hole
120: valve part 121: needle
122: Sleeve 130: Solenoid
131: first spring 132: second spring
133: housing 134: core
135: coil 136: plunger
141: first communication hole 142: second communication hole
145: Bypass hole

Claims (13)

A control valve for a variable capacity compressor, comprising a plurality of pistons coupled to a swash plate disposed in a crank chamber and reciprocatingly moving a refrigerant sucked from a suction chamber and discharging the compressed refrigerant into a discharge chamber,
The first control refrigerant flow rate that is sucked from the crank chamber through the first intermediate pressure port and discharged to the suction chamber through the low pressure port is increased when the variable capacity compressor is in the first capacity operation range, And a valve unit for increasing the operating capacity of the variable capacity compressor by increasing the inclination angle of the swash plate,
The valve unit includes:
And the second control refrigerant flow rate that is sucked from the discharge chamber through the high pressure port and discharged to the crank chamber through the second intermediate pressure port is decreased when the variable capacity compressor is in the first capacity operation range, The inclination angle of the swash plate is increased to further increase the operation capacity of the variable capacity compressor,
Further comprising a body in which the high-pressure port, the first intermediate-pressure port, and the second intermediate-pressure port are formed on the side, and the low-pressure port is formed in the lower portion,
A first communication hole and a bypass hole are formed in the body between the first intermediate pressure port and the low pressure port,
The valve unit includes:
A needle moving linearly along the first communication hole; And
And a sleeve coupled to the needle for controlling the degree of opening of the first communication hole,
Wherein the bypass hole is maintained in a fully opened state and the valve portion controls the opening degree of the first communication hole to vary the first control refrigerant flow rate. The method according to claim 1,
The valve unit includes:
Pressure port and a low-pressure port, and a variable communication area area in which a communication area between the first intermediate pressure port and the low-pressure port is variable, and a second communication area area in which the flow rate of the first control refrigerant The control valve for a variable displacement compressor. delete delete delete The method according to claim 1,
A second communication hole is formed in the body between the high pressure port and the second intermediate pressure port so as to be aligned with the first communication hole so that the needle can linearly move,
Wherein the second control coolant flow rate is variable by controlling a degree of opening of the second communication hole by a step formed on the needle while the needle moves linearly. The method of claim 6,
Wherein the first communication hole is completely opened and the second communication hole is closed when the variable displacement compressor performs the maximum displacement operation. The method of claim 6,
When the variable capacity compressor is operated in the second capacity operation range from the minimum operation capacity to the minimum value of the first capacity operation range, the first communication hole is closed and the second communication hole is in the fully opened state A control valve for a variable displacement compressor. The method according to claim 1,
Further comprising a bypass portion for connecting the crank chamber and the suction chamber,
Wherein the bypass portion is kept in a fully opened state so that the control refrigerant continuously flows from the crank chamber to the suction chamber through the bypass portion in the entire capacity operation range of the variable capacity compressor. A control valve for a variable capacity compressor, comprising a plurality of pistons coupled to a swash plate disposed in a crank chamber and reciprocatingly moving a refrigerant sucked from a suction chamber and discharging the compressed refrigerant into a discharge chamber,
The first and second intermediate pressure ports communicating with the crank chamber and the high pressure port communicating with the discharge chamber are formed apart from each other along the upper direction from the lower side of the side surface and the low pressure port communicating with the suction chamber is formed at the lower portion A body having a through-hole formed in a vertical direction;
A valve portion including a needle inserted in the through hole and linearly movable in the up and down direction, and a sleeve coupled to a lower portion of the needle; And
And a solenoid for applying an actuating force for linearly moving the needle in a vertical direction,
By the through hole, a first communication hole is defined between the first intermediate pressure port and the low pressure port, a second communication hole is defined between the high pressure port and the second intermediate pressure port,
The valve unit includes:
When the variable capacity compressor is in the first capacity operation range, the sleeve increases the degree of opening of the first communication hole while the needle is lowered by the solenoid, and the step formed on the needle causes the opening of the second communication hole The operation capacity of the variable displacement compressor is increased by reducing the pressure of the crank chamber and increasing the inclination angle of the swash plate,
The body is provided with a bypass hole communicating between the first intermediate pressure port and the low-pressure port and maintaining a fully opened state,
And the control refrigerant flows into the suction chamber from the crank chamber in the entire capacity operation range of the variable capacity compressor. delete The method of claim 10,
Wherein the first communication hole is formed to have an increased radius toward the lower side,
Wherein the sleeve is disposed at a lower portion of the first communication hole and the side surface is diagonal to correspond to the first communication hole. The method of claim 10,
The solenoid includes:
housing;
A core fixed to the housing and surrounding the needle, the guide guiding the needle linearly in a vertical direction;
A coil disposed to surround the core;
A plunger fixed to an upper portion of the needle and vertically moving together with the needle;
A first spring disposed between the plunger and an upper inner surface of the housing for applying a first elastic force to push the plunger downward; And
And a second spring disposed between the core and the plunger for applying a second elastic force to push the plunger upward,
Wherein the second elastic force is larger than the first elastic force and the downward movement of the needle is restricted in a second capacity operation range from a minimum capacity operation of the variable capacity compressor to a minimum value of the first capacity operation range, Control valve.

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