JP2006029144A - Displacement control valve of variable displacement swash plate type compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a displacement control valve of a variable displacement swash plate type compressor miniaturizable more than a conventional displacement control valve. <P>SOLUTION: This displacement control valve B of the variable displacement swash plate type compressor, controls delivery capacity of the variable displacement swash plate type compressor, by opening and closing a valve hole 106 formed of a communicating passage between a delivery chamber and a crank case of the variable displacement swash plate type compressor; and has the valve hole always communicating with the delivery chamber, a valve element 109 for opening and closing the valve hole, a support rod 111 slidably inserted into a support hole arranged in alignment in the valve hole and connected to the valve element, and an electromagnetic solenoid 120 for driving the valve element. Suction pressure or crank case pressure of the variable displacement swash plate type compressor, is impressed on an end part on the side separating from the valve element of the support rod. <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 valve hole formed by the communication path between the discharge chamber and the crank chamber of the variable capacity swash plate compressor. 1 and 4 of Patent Document 1 discloses a capacity control valve including a valve hole that is always in communication with a crank chamber, a valve body that opens and closes the valve hole, and an electromagnetic solenoid that drives the valve body. .
In the capacity control valve of Patent Document 1, the force F applied to the valve body when the valve is closed is expressed by the following equation. The following equation is based on the premise that the crank chamber pressure drops to substantially the same pressure as the suction pressure when the valve is closed.
F = f (I) −fs + (Pd−Ps) Sv + fs ′... 1
f (I): Electromagnetic force of the electromagnetic solenoid, fs: Energizing force of the open spring of the electromagnetic solenoid, Pd: Discharge pressure, Ps: Suction pressure, Sv: Valve hole area fs': Energizing force of the spring that presses the valve element
JP-A-7-286581

The capacity control valve of Patent Document 1 has the following problems.
When the valve is closed, the differential pressure between the discharge pressure Pd and the suction pressure Ps urges the valve body to close the valve body. Therefore, in order to demagnetize the electromagnetic solenoid and force the valve body to open, the electromagnetic solenoid release spring Must be set to (Pd−Ps) Sv + fs ′ or more. In order to forcibly open the valve body in the region where the discharge pressure Pd is high, it is necessary to use an open spring having a large spring force fs. The solenoid is excited to attract the movable iron core against the spring force fs of the open spring. In order to do so, it is necessary to generate a large electromagnetic force, which increases the size of the electromagnetic solenoid.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a capacity control valve of a variable capacity swash plate compressor that can be made smaller than the capacity control valve disclosed in Patent Document 1.

In order to solve the above-mentioned problems, in the present invention, the discharge capacity of the variable capacity swash plate compressor is reduced by opening and closing the valve hole formed by the communication path between the discharge chamber and the crank chamber of the variable capacity swash plate compressor. A displacement control valve of a variable displacement swash plate compressor to be controlled, which slides on a valve hole that is always in communication with a discharge chamber, a valve body that opens and closes the valve hole, and a support hole that is aligned with the valve hole. A support rod that is movably inserted and connected to the valve body, and an electromagnetic solenoid that drives the valve body, and the suction pressure of the variable capacity swash plate compressor at the end of the support rod that is separated from the valve body Alternatively, a displacement control valve is provided in which a crank chamber pressure is applied.
In the capacity control valve according to the present invention, the force F applied to the valve body when the valve is closed is expressed by the following equation. The following equation is based on the premise that the crank chamber pressure drops to substantially the same pressure as the suction pressure when the valve is closed.
F = f (I) −fs ± (Pd−Ps) × (Sv−Sr) 2
f (I): electromagnetic force of the electromagnetic solenoid, fs: biasing force of the open spring of the electromagnetic solenoid, Pd: discharge pressure, Ps: suction pressure, Sv: valve hole area, Sr: ± in the support rod cross-sectional area formula 2 , Sv> Sr is −, and Sv <Sr is +.
In the capacity control valve according to the present invention, in order to demagnetize the electromagnetic solenoid and force the valve body to open, the force fs of the opening spring of the electromagnetic solenoid is set to (Pd−Ps) × (Sv−Sr) or more. The spring force (Pd−Ps) × (Sv−Sr) is obviously smaller than the spring force (Pd−Ps) Sv + fs ′ required in the displacement control valve of Patent Document 1. Therefore, the capacity control valve according to the present invention can be downsized as compared with the capacity control valve of Patent Document 1.

In a preferred embodiment of the present invention, the valve hole area is set to be substantially the same as the support rod cross-sectional area and larger than the support rod cross-sectional area.
If the valve hole area Sv is set to be substantially the same as the support rod cross-sectional area Sr and larger than the support rod cross-sectional area Sr, the discharge pressure acts in the valve opening direction when the valve is closed. Therefore, if the electromagnetic solenoid is demagnetized, the valve element is reliably opened by the biasing force of the opening spring.

In the preferable aspect of this invention, the contact part with the valve body of a valve hole is formed with the hard material.
If the contact portion of the valve hole with the valve body, that is, the valve seat is formed of a hard material, wear of the valve seat due to repeated contact of the valve body is suppressed.

In a preferred embodiment of the present invention, the valve hole and the support hole are integrally formed of a hard material.
If the valve hole and the support hole are formed of a hard material, wear of the valve seat due to repeated contact of the valve body and wear of the support hole due to repeated sliding of the support rod are suppressed. If the valve hole and the support hole are integrally formed, the structure of the capacity control valve is simplified as compared with the case where both are formed separately.

In a preferred embodiment of the present invention, the valve hole and the support hole are formed, and the valve housing that accommodates the valve body and the support rod is formed of resin or aluminum alloy.
By forming the valve housing from resin or aluminum alloy, the capacity control valve is reduced in weight.

In the capacity control valve according to the present invention, the force of the opening spring of the electromagnetic solenoid necessary for forcibly opening the valve element is smaller than the force of the opening spring required for the capacity control valve of Patent Document 1. can do. Therefore, the capacity control valve according to the present invention can be downsized as compared with the capacity control valve of Patent Document 1.

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).
Between the cylinder block 16 and the cylinder head 23, a valve plate 24 in which a suction port and a discharge port communicating with the bore 16a are formed. A discharge valve and a suction valve are mounted on the valve plate 24.
The crank chamber 17 and the suction chamber 21 communicate with each other through an orifice hole 24 a formed in the valve plate 24.

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 solenoid 120 connected to the valve unit 100.

The valve unit 100 has a cylindrical valve housing 101. Three closed spaces 27a are provided around the valve housing 101 by two O-rings closely fitted to the valve housing 101 and one O-ring tightly fitted to the case of the electromagnetic solenoid 120. 27b, 27c are formed.
A lateral partition 104 that divides the internal space of the valve housing 101 into a pressure-sensitive chamber 102 on one end side and a valve chamber 103 on the other end side is formed in the valve housing 101. A support hole 105 communicating with the pressure sensing chamber 102 and a valve hole 106 communicating with the valve chamber 103 are formed in the horizontal partition wall 104. The support hole 105 and the valve hole 106 communicate with each other in alignment. A communication hole 107 is formed in the horizontal partition wall 104 so as to pass through the horizontal partition wall 104 in the radial direction through a communication portion between the support hole 105 and the valve hole 106.

The pressure sensing chamber 102 communicates with the suction chamber 21 via a closed space 27 a and a communication passage 23 a formed in the cylinder head 23.
The communication hole 107 communicates with the discharge chamber 22 via a closed space 27 b and a communication passage 23 b formed in the cylinder head 23. The valve hole 106 communicating with the communication hole 107 is always in communication with the discharge chamber 22.
The valve chamber 103 is cranked via a communication hole 108 formed in the valve housing 101, a closed space 27 c, a communication path 23 c formed in the cylinder head 23, and a communication path 16 b formed in the cylinder block 16. It communicates with the chamber 17.

A valve element 109 that opens and closes the valve hole 106 is disposed in the valve chamber 103. A small-diameter rod 110 extending from the valve body 109 is movably inserted into the valve hole 106. A support rod 111 integrally formed at the end of the small diameter rod 110 is slidably inserted into the support hole 105.
The valve unit 100 is formed by a valve housing 101 to a support rod 111.

The electromagnetic solenoid 120 includes a case 121. The end of the valve housing 101 on the valve chamber 103 side is press-fitted and fixed to one end of the case 121. As described above, the O-ring forming the closed space 27c is tightly fitted to the one end of the case 121.
The electromagnetic solenoid 120 is attached to the fixed iron core 122 arranged in the case 121, the movable iron core 123 arranged with one end facing the one end of the fixed iron core 122, and the movable iron core 123 in a direction away from the fixed iron core. It has an open spring 124 to be energized, an electromagnetic coil 125 surrounding the fixed iron core 122 and the movable iron core 123, and a rod 126 extending from the movable iron core 123 so as to freely pass through the fixed iron core 122.
The rod 126 is integrated with the valve body 109.
The rod insertion hole formed in the fixed iron core 122 and the accommodating space of the movable iron core 23 communicate with the valve chamber 103 and are at the same pressure as the valve chamber 103.

The operation of the capacity control valve B will be described.
When the electromagnetic coil 125 is excited, as shown in FIG. 2A, the movable iron core 123 moves toward the fixed iron core 122 against the biasing force of the opening spring 124, and the valve body 109 closes the valve hole 106.
Between the discharge chamber 22 and the crank chamber 17 formed by the communication path 23b, the closed space 27b, the communication hole 107, the valve hole 106, the valve chamber 103, the communication hole 108, the closed space 27b, the communication path 23c, and the communication path 16b. The communication passage is closed. Therefore, the high-pressure refrigerant gas in the discharge chamber 22 is not supplied to the crank chamber 17. The orifice passage 24a has a sufficient area for discharging blow-by gas that leaks from the cylinder bore 16a to the crank chamber 17 to the suction chamber 21 when the piston 15 compresses the refrigerant gas in the cylinder bore 16a. The chamber pressure gradually decreases. When the crank chamber pressure decreases, the swash plate tilt angle increases and the discharge capacity of the variable displacement swash plate compressor A increases.

When the electromagnetic coil 125 is demagnetized, the movable core 123 moves to the side away from the fixed core 122 by the biasing force of the release spring 124, and the valve body 109 opens the valve hole 106, as shown in FIG. To do. Inside the discharge chamber 22 through a communication path formed by the communication path 23b, the closed space 27b, the communication hole 107, the valve hole 106, the valve chamber 103, the communication hole 108, the closed space 27b, the communication path 23c, and the communication path 16b. High-pressure refrigerant gas is supplied to the crank chamber 17. The crank chamber pressure increases, the swash plate tilt angle decreases, and the discharge capacity of the variable displacement swash plate compressor A decreases.
The discharge capacity of the variable capacity swash plate compressor A is variably controlled by the excitation and demagnetization of the electromagnetic solenoid 120.

In the displacement control valve B, the force F applied to the valve body 109 when the valve is closed is expressed by the following equation. The following equation is based on the premise that the internal pressure of the crank chamber 107 drops to substantially the same pressure as the suction pressure when the valve is closed, and that the internal pressure of the valve chamber 103 is also applied around the movable core 123.
F = f (I) −fs ± (Pd−Ps) × (Sv−Sr) 2
f (I): electromagnetic force of the electromagnetic solenoid, fs: biasing force of the release spring of the electromagnetic solenoid, Pd: discharge pressure, Ps: suction pressure, Sv: valve hole area, Sr: support rod cross-sectional area formula 2, Sv> In the case of Sr, the academic symbol ± is −, and in the case of Sv <Sr, the academic symbol ± is +.
In the capacity control valve B, in order to demagnetize the electromagnetic solenoid 120 and force the valve element 109 to open, the force fs of the electromagnetic solenoid release spring 124 is set to (Pd−Ps) × (Sv−Sr) or more. The spring force (Pd−Ps) × (Sv−Sr) is obviously smaller than the spring force (Pd−Ps) Sv + fs ′ required in the displacement control valve of Patent Document 1. Therefore, the capacity control valve B can be reduced in size as compared with the capacity control valve disclosed in Patent Document 1 by using the open spring 124 having a small size.

Instead of communicating the pressure sensing chamber 102 with the suction chamber 21, the pressure sensing chamber 102 may be communicated with the crank chamber 17.

It is desirable to set the valve hole area Sv to be substantially the same as the support rod cross-sectional area Sr and larger than the support rod cross-sectional area Sr.
If the valve hole area Sv is set to be approximately the same as the support rod cross-sectional area Sr and greater than or equal to the support rod cross-sectional area Sr, the discharge pressure Pd acts in the valve opening direction when the valve is closed. Therefore, if the electromagnetic solenoid 120 is demagnetized, the valve element 109 is reliably opened by the biasing force of the opening spring 124.

As shown in FIG. 3, an annular member 112 made of a stainless steel material may be press-fitted and fixed to the transverse partition wall 104 to form a contact portion of the valve hole 106 with the valve body 109.
If the contact portion of the valve hole 106 with the valve body 109, that is, the valve seat is formed of a stainless steel material that is a hard material, wear of the valve seat due to repeated contact of the valve body 109 is suppressed.

As shown in FIG. 4, an annular member 113 made of a stainless steel material having a through hole 13a communicating with the communication hole 107 formed in the peripheral wall is press-fitted and fixed to the horizontal partition wall 104 to form a valve hole 106 and a support hole 105. May be.
If the valve hole 106 and the support hole 105 are made of a hard stainless steel material, the wear of the valve seat due to repeated contact of the valve element 109 and the wear of the support hole 105 due to repeated sliding of the support rod 111 are suppressed. Is done.
If the valve hole 106 and the support hole 105 are integrally formed by the annular member 113, the structure of the capacity control valve B is simplified as compared to the case where both are formed separately.

The valve housing 101 may be formed of resin or aluminum alloy.
By forming the valve housing 101 from resin or aluminum alloy, the capacity control valve B is reduced in weight.

As shown in FIG. 5, the capacity control valve C includes a valve part 200 and an electromagnetic solenoid 220 connected to the valve part 200.

The valve unit 200 has a cylindrical valve housing 201. Three closed spaces 27d around the valve housing 101 are provided by two O-rings tightly fitted to the valve housing 201 and one O-ring tightly fitted to the case of the electromagnetic solenoid 220. 27e, 27f are formed.
A transverse partition wall 204 that divides the internal space of the valve housing 201 into a valve chamber 202 on one end side and a pressure sensing chamber 203 on the other end side is formed in the valve housing 201. A valve hole 205 that communicates with the valve chamber 202 and a support hole 206 that communicates with the pressure sensing chamber 203 are formed in the horizontal partition wall 204. The valve hole 205 and the support hole 206 communicate with each other in alignment. A communication hole 207 is formed in the horizontal partition wall 204 so as to pass through the horizontal partition wall 104 in the radial direction through a communication portion between the valve hole 205 and the support hole 206.

The pressure sensing chamber 203 communicates with the suction chamber 21 or the crank chamber 17 through a communication hole 208 formed in the valve housing 201, a closed space 27d, and a communication passage (not shown) formed in the cylinder head 23. Yes.
The communication hole 207 communicates with the discharge chamber 22 via the closed space 27e and a communication passage 23b formed in the cylinder head 23. The valve hole 205 communicating with the communication hole 207 is always in communication with the discharge chamber 22.
The valve chamber 202 communicates with the crank chamber 17 through a closed space 27f, a communication path (not shown) formed in the cylinder head 23, and a communication path (not shown) formed in the cylinder block 16.

A valve body 209 that opens and closes the valve hole 205 is disposed in the valve chamber 202. A small diameter rod 210 extending from the valve body 209 is inserted into the valve hole 205 so as to be freely movable. A support rod 211 integrally formed at the end of the small diameter rod 210 is slidably inserted into the support hole 206.
The valve unit 200 is formed by a valve housing 201 to a support rod 211.

The electromagnetic solenoid 220 includes a case 221. The end of the valve housing 201 on the pressure sensing chamber 203 side is press-fitted and fixed to one end of the case 221. As described above, the O-ring that forms the closed space 27d is tightly fitted around the one end of the case 221.
The electromagnetic solenoid 220 is attached to the fixed iron core 222 arranged in the case 221, the movable iron core 223 arranged with one end facing the one end of the fixed iron core 222, and the movable iron core 223 away from the fixed iron core. It has an open spring 224 that energizes, an electromagnetic coil 225 that surrounds the fixed iron core 222 and the movable iron core 223, and a rod 226 that extends from the movable iron core 223.
The rod 226 is integrated with the support rod 211.
A space that accommodates the movable iron core 223 that forms one end of the support rod 211 on the side separated from the valve body 209 via the rod 226 communicates with the pressure-sensitive chamber 203. Therefore, the internal pressure of the pressure-sensitive chamber 203, that is, the suction pressure or the crank chamber pressure is applied to the movable iron core 223.

In the capacity control valve C, the force F acting on the valve body 209 when the valve is closed is the same as the force F acting on the valve body 109 when the valve is closed in the capacity control valve B according to the first embodiment.
Therefore, the capacity control valve C can be reduced in size compared to the capacity control valve of Patent Document 1 by using the open spring 224 having a small size.

The present invention can be widely used for a capacity control valve of a variable capacity swash plate compressor.

It is sectional drawing of the variable capacity | capacitance swash plate type compressor provided with the capacity | capacitance control valve based on 1st Example of this invention. It is sectional drawing of the capacity | capacitance control valve which concerns on 1st Example of this invention. (A) shows a valve closing state, (b) shows a valve opening state. It is sectional drawing of the modification of the capacity | capacitance control valve which concerns on 1st Example of this invention. (A) is a general view and (b) is a partially enlarged view. It is sectional drawing of the modification of the capacity | capacitance control valve which concerns on 1st Example of this invention. (A) is a general view and (b) is a partially enlarged view. It is sectional drawing of the capacity | capacitance control valve which concerns on 2nd Example of this invention. (A) shows a valve closing state, (b) shows a valve opening state.

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, 200 Valve portion 120, 220 Electromagnetic solenoid

Claims (5)

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 valve hole formed by the communication path between the discharge chamber and the crank chamber of the variable capacity swash plate compressor. A valve hole that always communicates with the discharge chamber, a valve body that opens and closes the valve hole, and a support hole that is arranged in alignment with the valve hole and is slidably inserted and connected to the valve body A support rod and an electromagnetic solenoid for driving the valve body are provided, and the suction pressure or the crank chamber pressure of the variable capacity swash plate compressor is applied to the end of the support rod that is separated from the valve body. Capacity control valve. 2. The capacity control valve for a variable displacement swash plate compressor according to claim 1, wherein the valve hole area is set to be substantially the same as the support rod sectional area and larger than the support rod sectional area. The capacity control valve for a variable capacity swash plate compressor according to claim 1 or 2, wherein a contact portion of the valve hole with the valve body is made of a hard material. The capacity control valve for a variable capacity swash plate compressor according to any one of claims 1 to 3, wherein the valve hole and the support hole are integrally formed of a hard material. 5. The valve housing according to claim 1, wherein a valve hole and a support hole are formed, and a valve housing that accommodates the valve body and the support rod is formed of a resin or an aluminum alloy. Capacity control valve for variable capacity swash plate compressor.

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