JP2006242002A - Capacity control valve for variable displacement swash plate compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacity control valve for a variable displacement swash plate compressor, for opening/closing a communication passage between a discharge chamber and a crank chamber depending on differential pressure between discharge pressure and suction pressure, and for preventing gas from flowing from the crank chamber into the suction chamber when the communication passage between the discharge chamber and the crank camber is opened. <P>SOLUTION: The capacity control valve for a variable displacement swash plate compressor makes the communication passage between the discharge chamber and the crank chamber open/close depending on differential pressure between the discharge pressure and the suction pressure. The capacity control valve has a first passage forming a part of the communication passage, a second passage forming a part of the communication passage between the crank chamber and the suction chamber, and a valve element. The valve element closes the second passage when the first passage should be opened, and opens the first passage when the second passage should be closed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a capacity control valve of a variable capacity compressor.

A capacity control valve for a variable capacity swash plate compressor that controls the discharge capacity of the variable capacity swash plate compressor by opening and closing the communication path between the discharge chamber and the crank chamber according to the pressure difference between the discharge pressure and the suction pressure. It is disclosed in Patent Document 1 and the like.
In the variable capacity swash plate compressor provided with the capacity control valve, an orifice passage is formed to connect the crank chamber and the suction chamber, and the capacity control valve closes the communication path between the discharge chamber and the crank chamber. Sometimes, the gas in the crank chamber flows into the suction chamber through the orifice passage, the internal pressure of the crank chamber decreases, the swash plate tilt angle increases, and the discharge capacity of the compressor increases.
JP 2001-132650 A

In a variable displacement swash plate compressor provided with a conventional displacement control valve disclosed in Patent Document 1 and the like, the displacement control valve opens a communication path between the discharge chamber and the crank chamber, and the high-pressure gas in the discharge chamber When the compressor discharge capacity of the compressor is reduced by increasing the internal pressure of the crank chamber and decreasing the swash plate inclination angle, a part of the high-pressure gas flowing into the crank chamber is sucked through the orifice passage. There is a problem in that a rapid increase in the crank chamber pressure and a rapid decrease in the compressor discharge capacity are hindered.
The present invention has been made in view of the above problems, and opens and closes the communication path between the discharge chamber and the crank chamber in accordance with the differential pressure between the discharge pressure and the suction pressure, thereby discharging the variable displacement swash plate compressor. A capacity control valve for a variable capacity swash plate compressor that controls the flow, and that prevents the outflow of gas from the crank chamber to the suction chamber when the communication passage between the discharge chamber and the crank chamber is opened. The purpose is to provide.

In order to solve the above problems, in the present invention, the discharge capacity of the variable capacity swash plate compressor is increased by opening and closing the communication path between the discharge chamber and the crank chamber in accordance with the differential pressure between the discharge pressure and the suction pressure. A displacement control valve for a variable displacement swash plate compressor to be controlled, wherein the first passage forms part of the communication passage, and the second passage forms part of the communication passage between the crank chamber and the suction chamber. And a valve body, wherein the valve body closes the second passage when opening the first passage, and opens the second passage when closing the first passage. provide.
The capacity control valve according to the present invention includes a first passage that forms a part of the communication path between the discharge chamber and the crank chamber, and a second part that forms a part of the communication path between the crank chamber and the suction chamber. Since the second passage is closed when the first passage is opened, the capacity control can be performed if the orifice passage between the crank chamber and the suction chamber, which has been conventionally provided, is eliminated. When the valve opens the communication path between the discharge chamber and the crank chamber, the outflow of gas from the crank chamber to the suction chamber can be prevented. On the other hand, when the communication passage between the discharge chamber and the crank chamber is closed, the second passage is opened, so that there is no hindrance to the outflow of gas from the crank chamber to the suction chamber. It will not hinder the increase in capacity.

When the end face of the valve body facing the valve hole formed by the second passage is a rotationally symmetric surface protruding with respect to the valve hole, the first passage is opened and the second passage is closed. The second passage can be reliably closed.

According to the present invention, there is provided a variable capacity swash plate compressor that controls a discharge capacity of a variable capacity swash plate compressor by opening and closing a communication path between the discharge chamber and the crank chamber in accordance with a differential pressure between the discharge pressure and the suction pressure. A capacity control valve is provided that can prevent gas from flowing out from the crank chamber to the suction chamber when the communication passage between the discharge chamber and the crank chamber is opened.

A capacity control valve according to an embodiment of the present invention will be described.
As shown in FIGS. 1 and 2, the variable capacity swash plate compressor A includes a main shaft 10, a rotor 11 fixed to the main shaft 10, and a swash plate 12 supported on the main shaft 10 so that the tilt angle is variable. . The swash plate 12 is connected to the rotor 11 via a link mechanism 13 that allows the tilt angle of the swash plate 12 to vary, and rotates in synchronization with the rotor 11 and thus the main shaft 10.
A piston 15 is moored to the swash plate 12 via a pair of shoes 14 that are in sliding contact with the peripheral edge of the swash plate 12. The piston 15 is inserted into a cylinder bore 16 a formed in the cylinder block 16.
A plurality of pistons 15 are arranged at intervals in the circumferential direction.

A dish-shaped front housing 18 is provided that forms a crank chamber 17 that accommodates the main shaft 10, the rotor 11, and the swash plate 12 in cooperation with the cylinder block 16. The main shaft 10 extends outside through the front housing 18. A shaft sealing member 19 for sealing the front housing penetrating portion of the main shaft 10 is disposed.
A pulley 20 fixed to the tip of the main shaft 10 is connected to a vehicle engine (not shown) via a belt (not shown).

A cylinder head 23 that forms a suction chamber 21 and a discharge chamber 22 is disposed. The suction chamber 21 is connected to an evaporator (not shown) of the in-vehicle air conditioner via a suction port (not shown). The discharge chamber 22 is connected to a condenser (not shown) of the in-vehicle air conditioner via a discharge port (not shown).
A valve plate 24 having a suction port and a discharge port communicating with the cylinder bore 16a is disposed between the cylinder block 16 and the cylinder head 23. A discharge valve and a suction valve are mounted on the valve plate 24.
The orifice passage between the crank chamber 17 and the suction chamber 21 provided in the conventional variable displacement swash plate compressor including the displacement control valve is not provided with the variable displacement swash plate compressor according to the present embodiment.

The front housing 18, the cylinder block 16, the valve plate 24, and the cylinder head 23 are integrally fastened by a plurality of through bolts 25 that are spaced apart from each other along a circumference around the main shaft 10.

A capacity control valve B for controlling the discharge capacity of the variable capacity swash plate compressor A is fitted and fixed in a recess 26 formed in the cylinder head 23 adjacent to the discharge chamber 22.
As shown in FIGS. 1 and 2, the capacity control valve B includes a valve unit 100 and an electromagnetic actuator 110 connected to the valve unit 100.

The valve unit 100 has a cylindrical valve housing 101. Three closed spaces 27a, 27b, and 27c are formed around the valve housing 101 by three O-rings tightly fitted to the valve housing 101.
The closed space 27 a communicates with the discharge chamber 22 through a communication passage 23 a formed in the cylinder head 23. The closed space 27 b communicates with the crank chamber 17 through a communication path 23 b formed in the cylinder head 23 and a communication path 16 b formed in the cylinder block 16. The closed space 27 c communicates with the suction chamber 21 through a communication path 23 c formed in the cylinder head 23.

At one end of the valve housing 101, a valve hole 102 that is always in communication with the closed space 27 a and thus the discharge chamber 22 is formed.
A valve chamber 103 that can communicate with the valve hole 102 is formed in the valve housing 101 adjacent to the valve hole 102. The valve chamber 103 communicates with the closed space 27 b and thus the crank chamber 17 through a communication hole 104 formed in the valve housing 101.
A valve body 105 that opens and closes the valve hole 102 close to and away from the valve hole 102 is disposed in the valve chamber 103.
A rod 106 having one end fixed to the valve body 105 extends toward the electromagnetic actuator 110 through a rod support hole 107 formed in the valve housing 101.
A communication hole 108 formed in the valve housing 101 communicates with the rod support hole 107 and the closed space 27c.
An annular gap S having a predetermined width is formed between the rod 106 and a peripheral wall of a portion of the rod support hole 107 that extends between the communication hole 108 and the valve chamber 103. An end surface 105a of the valve body 105 facing the valve hole formed by the annular gap S forms a rotationally symmetric surface such as a conical surface or a spherical surface that protrudes from the valve hole. When the valve body 105 separates and approaches the valve hole 102 to open and close the valve hole 102, the valve body 105 approaches and separates from the valve hole formed by the annular gap S to close and open the valve hole.

The electromagnetic actuator 110 includes a case 111. Inside the case 111, a fixed iron core 112, a movable iron core 113 disposed with one end facing the one end of the fixed iron core 112, and an unillustrated open spring that urges the movable iron core 113 away from the fixed iron core 112. An electromagnetic coil 114 that surrounds the fixed iron core 112 and the movable iron core 113 is disposed.
The rod 106 having one end fixed to the valve body 105 is connected to the movable core 113 through a rod insertion hole formed in the fixed core 112.
The rod insertion hole formed in the fixed iron core 112 and the accommodating space of the movable iron core 113 communicate with the communication path 108 via the rod support hole 107 and have the same pressure as the communication path 108.

The operation of the capacity control valve B will be described.
During the capacity control operation of the variable capacity swash plate compressor A, the electromagnetic coil 114 is excited by energization. The movable iron core 113 moves toward the fixed iron core 112 against the urging force of the opening spring, and the valve body 105 closes the valve hole 102 and opens the valve hole formed by the annular gap S. As a result, the communication between the discharge chamber 22 and the crank chamber 17 formed by the communication path 23a, the closed space 27a, the valve hole 102, the valve chamber 103, the communication hole 104, the closed space 27b, the communication path 23b, and the communication path 16b. The passage is closed, the communication passage 16b, the communication passage 23b, the closed space 27b, the communication hole 104, the valve chamber 103, a portion extending between the communication hole 108 of the rod support hole 107 and the valve chamber 103, the communication hole 108, A communication path between the crank chamber 17 and the suction chamber 21 formed by the closed space 27c and the communication 23c is opened.
The high-pressure refrigerant gas in the discharge chamber 22 is not supplied to the crank chamber 17, and the refrigerant gas in the crank 17 flows out to the suction chamber 21. The crank chamber pressure decreases, the swash plate tilt angle increases, and the discharge capacity of the variable capacity swash plate compressor A increases.
The crank chamber pressure is substantially the same as the suction pressure Ps, and the internal pressure in the housing space of the valve chamber 103 and the movable iron core 113 is the suction pressure Ps. Therefore, the urging force due to the discharge pressure Pd and the urging force by the release spring act on the valve body 105 as a force that urges the valve body 105 in the valve opening direction, and the urging force due to the suction pressure Ps and the electromagnetic force of the electromagnetic coil 114. f acts as a force for urging the valve body 105 in the valve closing direction.

During the displacement control operation, the differential pressure between the discharge pressure Pd and the suction pressure Ps exceeds a predetermined value, and the sum of the biasing force by the discharge pressure Pd acting on the valve body 105 and the biasing force by the release spring and the biasing force by the suction pressure Ps When the difference exceeds the electromagnetic force f, the valve body 105 opens the valve hole 102 and closes the valve hole formed by the annular gap S. Since the end surface 105a of the valve body 105 facing the valve hole formed by the annular gap S forms a rotationally symmetric surface such as a conical surface or a spherical surface protruding with respect to the valve hole, the valve body 105 is reliably The valve hole is closed.
The communication path between the discharge chamber 22 and the crank chamber 17 is opened so that the high-pressure gas in the discharge chamber 22 flows into the crank chamber 17, while the communication path between the crank chamber 17 and the suction chamber 21 is closed. The outflow of gas from the crank chamber 17 to the suction chamber 21 is prevented. The inner chamber of the crank chamber 17 rises, the inclination angle of the swash plate 12 decreases, and the discharge capacity of the variable capacity swash plate compressor A decreases. As a result, the differential pressure between the discharge pressure Pd and the suction pressure Ps decreases, and the difference between the sum of the biasing force due to the discharge pressure Pd acting on the valve body 105 and the biasing force due to the release spring and the biasing force due to the suction pressure Ps decreases. .

When the difference between the sum of the biasing force due to the discharge pressure Pd acting on the valve body 105 and the biasing force due to the release spring and the biasing force due to the suction pressure Ps becomes less than the electromagnetic force f, the valve body 105 closes the valve hole 102 to form an annular shape. A valve hole formed by the gap S is opened. The high pressure gas in the discharge chamber 22 stops flowing into the crank chamber 17, and the gas in the crank chamber 17 flows out to the suction chamber 21. If the annular gap S is set to an appropriate value, the gas flows from the crank chamber 17 to the suction chamber 21 quickly. The internal pressure of the crank chamber 17 decreases, the inclination angle of the swash plate 12 increases, and the discharge capacity of the variable capacity swash plate compressor A increases.

The opening / closing of the valve hole 102 by the valve body 105 and the opening / closing of the valve hole formed by the annular gap S are repeated, and the increase / decrease in the inclination angle of the swash plate is repeated, whereby the biasing force due to the discharge pressure Pd acting on the valve body 105 The state where the difference between the sum of the bias by the release spring and the bias force by the suction pressure Ps is balanced with the electromagnetic force f is maintained, and the differential pressure between the discharge pressure Pd and the suction pressure Ps becomes a predetermined value determined by the electromagnetic force f. Maintained.

When the electromagnetic coil 114 is demagnetized, the movable iron core 113 moves to the side away from the fixed core 112 by the biasing force of the release spring, the valve body 105 opens the valve hole 102, and the valve hole formed by the annular gap S is opened. Close. The crank chamber pressure increases, the swash plate tilt angle decreases, and the discharge capacity of the variable capacity swash plate compressor A decreases to the minimum capacity.

The capacity control valve B according to the present embodiment includes a first passage that forms part of a communication passage between the discharge chamber 22 and the crank chamber 17 of the variable capacity swash plate compressor A, specifically, a valve hole 102. A second passage that includes the valve chamber 103 and the communication hole 104 and forms a part of the communication passage between the crank chamber 17 and the suction chamber 21, specifically, the communication hole 104, the valve chamber 103, and the rod A portion of the support hole 107 extending between the communication hole 108 and the valve chamber 103 and the communication hole 108 are provided, and the second passage is closed when the first passage is opened. In the swash plate compressor A, the orifice passage between the crank chamber and the suction chamber, which has been conventionally provided, is not formed, so that the capacity control valve B communicates with the discharge chamber 22 and the crank chamber 17. When the valve is opened, the outflow of gas from the crank chamber 17 to the suction chamber 21 can be prevented. That. Therefore, the discharge capacity of the variable capacity swash plate compressor A can be quickly reduced. On the other hand, when the first passage is closed and the communication passage between the discharge chamber 22 and the crank chamber 17 is closed, the second passage is opened, so that gas flows from the crank chamber 17 to the suction chamber 21. Does not hinder the increase in the discharge capacity of the variable capacity swash plate compressor A.

An end surface 105a of the valve body 105 that faces the valve hole formed by the annular gap S that is a part of the second passage forms a rotationally symmetric surface such as a conical surface or a spherical surface that protrudes from the valve hole. Therefore, when opening the communication path between the discharge chamber 22 and the crank chamber 17, the valve body 105 reliably closes the valve hole, and the communication path between the crank chamber 17 and the suction chamber 21. Can be securely closed.

The present invention relates to a variable capacity swash plate compressor that controls the discharge capacity of a variable capacity swash plate compressor by opening and closing the communication path between the discharge chamber and the crank chamber in accordance with the differential pressure between the discharge pressure and the suction pressure. It can be used for a capacity control valve.

It is sectional drawing of a variable capacity | capacitance swash plate type compressor provided with the capacity | capacitance control valve based on the Example of this invention. It is sectional drawing of the capacity | capacitance control valve which concerns on the Example of this invention.

Explanation of symbols

A Variable displacement swash plate compressor B, C Capacity control valve 17 Crank chamber 21 Suction chamber 22 Discharge chamber 26 Recess 100 Valve portion 102 Valve hole 105 Valve body 120 Electromagnetic actuator

Claims (2)

A capacity control valve for a variable capacity swash plate compressor that controls the discharge capacity of a variable capacity swash plate compressor by opening and closing the communication path between the discharge chamber and the crank chamber according to the pressure difference between the discharge pressure and the suction pressure. A first passage that forms a part of the communication passage, a second passage that forms a part of the communication passage between the crank chamber and the suction chamber, and a valve body. A capacity control valve characterized by closing the second passage when opening one passage, and opening the second passage when closing the first passage. 2. The capacity control valve according to claim 1, wherein an end face of the valve body facing the valve hole formed by the second passage forms a rotationally symmetric surface protruding with respect to the valve hole.

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