JP2014043823A - On-off valve of refrigeration device, compressor, and refrigeration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-off valve capable of reducing pressure loss in a refrigeration device.SOLUTION: A check valve 200 disposed in a discharge passage 104b of a compressor constituting a refrigeration device, includes a first compression coil spring 202 disposed between the valve element 201 and a pressure sensitive rod 204 so as to be compressed, for urging a valve element 201 to a valve closing direction. Pressure of a discharge passage 104b in a downstream of the check valve 200, acts on an end portion at a valve element 201 side of the pressure sensitive rod 204, and pressure of a suction chamber 141 acts on an end portion at a side opposite to the valve element 201 side, of the pressure sensitive rod 204, and the pressure sensitive rod 204 is moved in such a direction as to be separated from and brought into contact with the valve element 201 according to the pressure difference. Accordingly, in an operation state where a refrigerant is circulated by the compressor, the differential pressure between areas through the pressure sensitive rod 204 is increased to reduce urging force of the first compression coil spring 202, and in a non-operation state where the circulation of the refrigerant by the compressor is stopped, the differential pressure is decreased to increase the urging force of the first compression coil spring 202.

Description

  The present invention relates to an on-off valve that opens and closes a high-pressure side refrigerant passage in a refrigeration apparatus (refrigeration cycle apparatus) including a compressor.

  Patent Document 1 discloses an on-off valve (check valve) interposed in a discharge passage of a compressor.

JP 2000-346217 A

The on-off valve (check valve) interposed in the discharge passage of the compressor is opened when the compressor where the differential pressure increases and decreases and closes when the compressor where the differential pressure decreases is not operating. The refrigerant circulation in the refrigeration apparatus (refrigeration cycle apparatus) is interrupted.
However, since the on-off valve (check valve) does not open unless the valve opening differential pressure is exceeded, a large pressure loss occurs at the on-off valve (check valve) during compressor operation if the valve opening differential pressure setting is large. This has caused a reduction in compressor performance.

  Then, an object of this invention is to provide the on-off valve which can reduce pressure loss in a freezing apparatus.

  In order to achieve the above object, an on-off valve according to the present invention is an on-off valve that is interposed in a high-pressure side refrigerant passage of a refrigeration apparatus and that opens and closes according to a differential pressure across the valve. When the differential pressure between the biasing member to be biased and the refrigerant pressure on the high pressure side downstream of the on-off valve and the refrigerant pressure on the low pressure side of the refrigeration apparatus is increased, the biasing force of the biasing member is reduced, and the differential pressure Adjustment means for increasing the urging force of the urging member when the urging force decreases.

  According to the on-off valve according to the present invention, in the operating state in which the refrigerant is circulated in the refrigeration apparatus, the urging force (force acting in the valve closing direction) by the urging member is weakened compared to the non-operating state. While the pressure loss is reduced, in the non-operating state in which the circulation of the refrigerant is stopped, the urging force by the urging member becomes stronger than that during the operation, and the on-off valve can be stably held in the closed state.

It is a figure which shows the freezing apparatus in embodiment of this invention. It is sectional drawing which shows the compressor in embodiment of this invention. It is sectional drawing which shows the non-return valve with which the compressor in embodiment of this invention was equipped. It is sectional drawing which shows the open / close state of the non-return valve in embodiment of this invention. It is sectional drawing which shows the open / close state of the non-return valve in embodiment of this invention. It is a figure which shows the change of the valve opening differential pressure | voltage of the non-return valve in embodiment of this invention. It is a figure which shows the freezing apparatus provided with the non-return valve in the high voltage | pressure side piping in embodiment of this invention. It is sectional drawing which shows the non-return valve arrange | positioned at the high voltage | pressure side piping of the freezing apparatus in embodiment of this invention.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 shows an exemplary configuration of a refrigeration apparatus (refrigeration cycle apparatus) 500.
A refrigeration apparatus 500 shown in FIG. 1 is, for example, a vehicle air conditioner system, and includes a variable capacity compressor 100, a condenser 600, an expansion valve 700, and an evaporator 800.

The variable capacity compressor 100 compresses a low-temperature and low-pressure gas refrigerant into a high-temperature and high-pressure gas refrigerant, the condenser 600 radiates heat from the high-temperature and high-pressure gas refrigerant into a high-pressure liquid refrigerant, and the expansion valve 700 The high-pressure liquid refrigerant is expanded into a fine pore (fine tube) to form a low-temperature and low-pressure mist-like refrigerant, and the evaporator 800 vaporizes the low-temperature and low-pressure mist-like refrigerant and heats around the evaporator 800. Inhale. The opening of the expansion valve 700 is adjusted so that evaporation is completed at the outlet of the evaporator 800, and a low-temperature and low-pressure gas refrigerant is generated at the outlet of the evaporator 800.
At the time of cooling, the evaporator 800 takes the heat in the passenger compartment and cools it, and the condenser 600 releases the heat to the outside.
In the refrigeration apparatus 500, the space between the variable displacement compressor 100 and the expansion valve 700 is on the high pressure side, and the space between the expansion valve 700 and the variable displacement compressor 100 is on the low pressure side.

Next, an example of the variable capacity compressor (refrigerator) 100 constituting the refrigeration apparatus 500 will be described with reference to FIG.
The variable capacity compressor 100 is provided with a cylinder block 101 having a plurality of cylinder bores 101a, a front housing 102 provided at one end of the cylinder block 101, and a valve plate 103 at the other end of the cylinder block 101. A cylinder head 104.

The drive shaft 110 is provided across the crank chamber 140 formed by the cylinder block 101 and the front housing 102.
A swash plate 111 is disposed around an intermediate portion of the drive shaft 110 in the axial direction.
The swash plate 111 is connected to a rotor 112 fixed to the drive shaft 110 via a link mechanism 120 so that an inclination angle with respect to the drive shaft 110 can be changed.

  The link mechanism 120 includes a first arm 112 a projecting from the rotor 112, a second arm 111 a projecting from the swash plate 111, and one end rotating relative to the first arm 112 a via the first connecting pin 122. A link arm 121 that is movably coupled and has the other end pivotally coupled to the second arm 111a via a second coupling pin 123.

The through hole 111b of the swash plate 111 is formed in a shape that allows the swash plate 111 to tilt within the range of the maximum tilt angle (θmax) and the minimum tilt angle (θmin). Is formed.
When the inclination angle of the swash plate 111 when the swash plate 111 is orthogonal to the drive shaft 110 is 0 deg, the minimum inclination restricting portion of the through hole 111b is formed so that the swash plate 111 can be inclined to approximately 0 deg. Yes.

Between the rotor 112 and the swash plate 111, an inclination-decreasing spring 114 that biases the swash plate 111 toward the minimum inclination angle is mounted, and between the swash plate 111 and the spring support member 116 provided on the drive shaft 110. Is attached with an inclination increasing spring 115 that urges the swash plate 111 in an increasing direction.
Here, the biasing force of the tilt-increasing spring 115 at the minimum tilt angle is set larger than the biasing force of the tilt-decreasing spring 114, and when the drive shaft 110 is not rotating, the swash plate 111 is The biasing force and the biasing force of the tilt angle increasing spring 115 are positioned at an inclination angle that balances.

One end of the drive shaft 110 extends through the inside of the boss portion 102a of the front housing 102 to the outside of the front housing 102, and is connected to a power transmission device (not shown).
A shaft seal device 130 is inserted between the drive shaft 110 and the boss portion 102a to block the inside of the crank chamber 140 from the external space.

The drive shaft 110 and the rotor 112 are supported by bearings 131 and 132 in the radial direction, and supported by a bearing 133 and a thrust plate 134 in the thrust direction. The gap between the thrust plate 134 of the drive shaft 110 and the thrust plate 134 is adjusted to a predetermined gap by the adjustment screw 135.
The power from the external drive source is transmitted to the power transmission device, and the drive shaft 110 rotates in synchronization with the power transmission device.

A piston 136 is disposed in the cylinder bore 101a, and an outer peripheral portion of the swash plate 111 is accommodated in an inner space of an end portion of the piston 136 that protrudes toward the crank chamber 140. The swash plate 111 includes a pair of shoes 137. Via the piston 136. Accordingly, the piston 136 reciprocates in the cylinder bore 101a by the rotation of the swash plate 111.
The cylinder head 104 is formed with a suction chamber 141 disposed in the center and a discharge chamber 142 surrounding the suction chamber 141 in an annular shape.

The suction chamber 141 communicates with the cylinder bore 101a via a communication hole 103a provided in the valve plate 103 and a suction valve (not shown) formed on the suction valve forming plate, and the discharge chamber 142 communicates with the cylinder bore 101a. In contrast, a discharge valve (not shown) formed on the discharge valve forming plate and a communication hole 103 b provided in the valve plate 103 communicate with each other.
The front housing 102, cylinder block 101, valve plate 103, and cylinder head 104 are fastened by a plurality of through bolts 105 via a center gasket, cylinder gasket, and head gasket (not shown) to form a compressor housing.

The cylinder head 104 includes a suction passage 104a for connecting a low-pressure side pipe (a pipe connecting the compressor 100 and the evaporator 400) and the suction chamber 141 of the refrigeration apparatus 500, and a high-pressure side pipe (compression) of the refrigeration apparatus. And a discharge passage 104b for connecting the discharge chamber 142 to the pipe 100 connecting the machine 100 and the condenser 200).
Further, the cylinder head 104 is provided with a check valve 200 as an on-off valve that opens and closes the discharge passage 104b, in other words, the high-pressure side refrigerant passage of the refrigeration apparatus 500.

  The check valve 200 is a valve that operates according to a pressure difference (front-rear differential pressure) between the pressure of the discharge chamber 142 upstream of the check valve 200 and the pressure of the discharge passage 104 b downstream of the check valve 200. . When the front-rear differential pressure is smaller than the valve-opening differential pressure (threshold value), the check valve 200 closes and blocks the discharge passage 104b to prevent the refrigerant from flowing backward. Is larger than the threshold value), that is, when the pressure in the discharge chamber 142 upstream of the check valve 200 is higher than the pressure in the discharge passage 104b downstream of the check valve 200, the discharge passage 104b opens. The refrigerant is circulated by opening.

The cylinder head 104 is further provided with a control valve 300.
The control valve 300 controls the amount of discharge gas introduced into the crank chamber 140 by adjusting the opening of the communication passage 145 that communicates the discharge chamber 142 and the crank chamber 140. The refrigerant in the crank chamber 140 flows to the suction chamber 141 via the communication passage 101 c, the space 146, and the orifice 103 c formed in the valve plate 103.

Therefore, the discharge capacity of the variable capacity compressor 100 can be variably controlled by changing the pressure of the crank chamber 140 by the control valve 300 and changing the inclination angle of the swash plate 111, that is, the stroke of the piston 136.
When the refrigeration apparatus 500 is operating, that is, when the variable capacity compressor 100 is operating, the energization amount of the solenoid built in the control valve 300 is adjusted based on the external signal so that the pressure in the suction chamber 141 becomes a predetermined value. The discharge capacity is variably controlled, and the control valve 300 optimally controls the suction pressure according to the external environment.
Further, when the refrigeration apparatus is not operated, that is, when the variable capacity compressor 100 is not operated, the energization of the solenoid built in the control valve 300 is turned off to forcibly open the communication path 145 and the variable capacity compressor 100. The discharge capacity is controlled to the minimum.

Hereinafter, an example of the check valve 200 will be described in detail with reference to FIGS.
The cylinder head 104 is formed with a cylindrical check valve accommodation hole 104c along a direction parallel to the axial direction of the drive shaft 110 so as to face the discharge chamber 142, and the check valve 200 includes the accommodation hole. It is disposed within 104 c and is prevented from coming off by a snap ring 150.

The check valve 200 includes a valve body 201 that opens and closes the discharge passage 104b, a first compression coil spring 202 that is an urging member (elastic body) that urges the valve body 201 in the valve closing direction, and valve closing by the first compression coil spring 202. A pressure-sensitive rod (pressure-sensitive member) 204 that changes the biasing force in the direction, and a biasing member that biases the pressure-sensitive rod 204 toward the valve body 201, in other words, a direction that compresses the first compression coil spring 202. A second compression coil spring 206 that is (elastic body), a valve housing 207, and the like are provided.
In the present embodiment, a coil spring is used as an example of an elastic body that functions as an urging member, but is not limited to a coil spring, and a plate spring, a disc spring, or the like can be used as an urging member. Rubber can also be used as the biasing member.

  The valve body 201 and the pressure sensitive rod 204 are provided so as to be movable along an axis parallel to the axial direction of the drive shaft 110 while being in sliding contact with the inner peripheral surface of the valve housing 207. A spring guide 203 is fixed to the end of the pressure-sensitive rod 204 on the valve body 201 side, and a first compression coil spring 202 is provided in a compressed state between the spring guide 203 and the valve body 201, so that the first The compression coil spring 202 urges the valve body 201 in a direction away from the pressure-sensitive rod 204 with the spring guide 203 as a support end, that is, in a valve closing direction.

The pressure of the discharge passage 104b (high-pressure side refrigerant pressure) downstream from the check valve 200 (valve body 201) acts on the end of the pressure-sensitive rod 204 on the valve body 201 side. The pressure of the suction chamber 141 acts on the end opposite to the 201 side, and the pressure-sensitive rod 204 moves away from or in contact with the valve body 201 according to the pressure difference, that is, the first compression coil spring. 202 is moved in the direction of compressing and expanding.
A spring guide 205 is fixed to the end of the pressure sensitive rod 204 opposite to the valve body 201 side, and a second compression coil spring 206 (second urging member) is provided between the spring guide 205 and the valve housing 207. Are provided in a compressed state.

The valve housing 207 houses the valve body 201, the first compression coil spring 202, the pressure sensitive rod 204, and the second compression coil spring 206.
In order to suppress pressure leakage through the check valve 200, the check valve 200 includes O-rings 208 to 210 and a pressing member 211.
The valve housing 207 is composed of three parts, a first member 207a, a second member 207b, and a third member 207c. The second member 207b is fitted to the first member 207a, and the third member 207c is fitted to the second member 207b. The valve housing 207 is formed by fitting.

Here, when the second member 207b is fitted to the first member 207a, a peripheral groove is formed in the outer peripheral portion between the first member 207a and the second member 207b, and an O-ring 208 is formed in the peripheral groove. Arranged.
Further, by fitting the third member 207c to the second member 207b, a circumferential groove is formed in the outer peripheral portion between the second member 207b and the third member 207c, and an O-ring 209 is arranged in this circumferential groove. Established.

The O-ring 208 and the O-ring 209 seal a gap between the inner periphery of the check valve accommodation hole 104 c and the outer periphery of the valve housing 207.
The first member 207a is made of a metal material such as brass, and the second member 207b and the third member 207c are made of resin.

A region around the second member 207b defined between the O-ring 208 and the O-ring 209 constitutes a part of the discharge passage 104b. Further, the pressure in the suction chamber 141 (low-pressure side refrigerant) is connected to the region in the accommodation hole 104c around the third member 207c, which is partitioned from the region around the second member 207b by the O-ring 209. Pressure) is introduced.
Here, the suction chamber 141 is arranged at the center of the cylinder head 104, and the region inside the accommodation hole 104c around the third member 207c is arranged on the outer side in the radial direction. Therefore, the suction chamber 141 and the accommodation hole 104c are separated from each other. The communication hole 104d can be easily formed adjacent to the cylinder head 104 in the radial direction.

The valve body 201 is formed of, for example, resin, and includes a cylindrical outer peripheral portion 201a and a flat portion 201b that closes one end of the cylindrical outer peripheral portion 201a, and the cylindrical outer peripheral portion 201a is slidable on the inner peripheral surface of the second member 207b. Supported by
The internal space of the second member 207b is defined by the valve body 201 into a first space 220 that becomes a part of the discharge passage 104b and a second space 221 in which the first compression coil spring 202 is disposed.

A third space 222 defined by the pressure sensitive rod 204 and the second space 221 is formed inside the third member 207 c, and the second compression coil spring 206 is disposed in the third space 222.
An outlet hole 207b1 is formed in the peripheral wall of the second member 207b to connect the first space 220 and the area around the second member 207b (the discharge passage 104b on the downstream side of the valve body 201). An inlet hole 207a1 that allows the first space 220 and the discharge chamber 142 to communicate with each other is formed.

In addition, the inlet hole 207a1, the first space 220, the outlet hole 207b1, the area around the second member 207b defined between the O-ring 208 and the O-ring 209, downstream from the check valve 200 (valve body 201). The discharge passage 104b communicates with the discharge chamber 142 by the discharge passage 104b.
In the first member 207a, a valve seat 207a2 is formed around the end portion of the inlet hole 207a1 on the first space 220 side, and the flat portion 201b of the valve body 201 abuts on the valve seat 207a2, thereby allowing the discharge passage 104b to pass through. The valve is closed, and the flat portion 201b of the valve body 201 is separated from the valve seat 207a2, so that the discharge passage 104b is opened.

A communication hole 207b2 into which the pressure sensitive rod 204 is inserted is formed at the center of the second member 207b. By inserting the pressure sensitive rod 204 into the communication hole 207b2, the second space 221 and the third space 222 are inserted. It is defined by.
The pressure sensitive rod 204 is made of, for example, a stainless metal material.
A communication hole 207b3 is formed in the peripheral wall of the second member 207b to communicate the second space 221 with the area around the second member 207b defined between the O-ring 208 and the O-ring 209. As a result, the pressure in the discharge passage 104b downstream from the check valve 200 (valve body 201) (the high-pressure side refrigerant pressure downstream from the check valve 200) is introduced into the second space 221.

The third member 207c is formed with a communication hole 207c1 that communicates the third space 222 and a region in the accommodation hole 104c around the third member 207c. The pressure in the suction chamber 141 is introduced into the region in the storage hole 104c through the communication hole 104d. Therefore, the pressure of the suction chamber 141 (the refrigerant pressure on the low pressure side of the refrigeration apparatus 500) is introduced into the third space 222.
One end of the pressure-sensitive rod 204 protrudes into the second space 221 and receives the first compression coil spring 202 via the spring guide 203, and the other end of the pressure-sensitive rod 204 protrudes into the third space 222 and passes through the spring guide 205. The second compression coil spring 206 is received.

An O-ring 210 is disposed at the end of the communication hole 207b2 of the second member 207b on the valve body 201 side, and the O-ring is prevented from coming off by a pressing member 211.
The O-ring 210 seals the gap between the outer peripheral surface of the pressure-sensitive rod 204 and the communication hole 207b2, and the refrigerant (pressure) between the second space 221 and the third space 222 via the gap. ) To prevent leakage.

As a result, the pressure in the discharge passage 104b downstream from the check valve 200 (valve body 201) (the refrigerant pressure on the high pressure side downstream from the check valve 200) acts on one end side of the pressure sensitive rod 204. The pressure of the suction chamber 141 (the refrigerant pressure on the low pressure side of the refrigeration apparatus 500) acts on the other end side of the pressure rod 204, and the area where the pressure acts is that of the pressure sensitive rod 204 sealed by the O-ring 210. Cross-sectional area.
The spring guide 203 includes a recess 203 a that houses one end of the pressure-sensitive rod 204 and a flange 203 b formed around the recess 203 a, and one end surface of the flange 203 b serves as a receiving surface (support surface) of the first compression coil spring 202.

On the other hand, the other end surface of the flange 203b abuts on one end surface of the pressing member 211 when the pressure sensitive rod 204 moves to the third space 222 side, and restricts the movement of the pressure sensitive rod 204 to the third space 222 side. . That is, the other end surface (moving end) of the flange 203b and the corresponding one end surface (fixed end) of the pressing member 211 as a regulating surface on the valve housing 207 side are directed to the third space 222 side of the pressure-sensitive rod 204. The 1st stopper part which restrict | limits the movement of is comprised.
The position where the other end surface of the flange 203b contacts the one end surface of the pressing member 211 is a position where the pressure-sensitive rod 204 moves most toward the third space 222 side, and the pressure-sensitive rod 204 moves most toward the third space 222 side. As a result, the support end of the first compression coil spring 202 is furthest away from the valve seat 207a2.

Accordingly, the position of the pressure-sensitive rod 204 where the other end surface of the flange 203b contacts the one end surface of the pressing member 211 is such that the biasing force of the first compression coil spring 202 that biases the valve body 201 in the valve closing direction is the minimum value f1min. At this time, when the following expressions (1) and (1 ′) are established, the valve body 201 is opened.
(PdH-PdL) .Sv-f1min> 0 (1)
PdH−PdL = ΔPdmin> f1min / Sv (1 ′)

In the above formulas (1) and (1 ′), PdH is the pressure in the discharge chamber 142, PdL is the pressure in the discharge passage 104b downstream from the check valve 200 (valve body 201), and ΔPdmin is the opening difference of the check valve 200. The minimum value of pressure, Sv, indicates the pressure receiving area when the valve body 201 is seated on the valve seat 207a2.
Note that the minimum value ΔPdmin of the valve opening differential pressure is the minimum value of the variable range of the valve opening differential pressure (threshold) that changes as the urging force of the first compression coil spring 202 changes depending on the position of the pressure-sensitive rod 204. The valve opening differential pressure when the urging force of the first compression coil spring 202 is the minimum value f1min.

The spring guide 205 includes a recess 205 a that houses one end of the pressure-sensitive rod 204 and a flange 205 b formed around the recess 205 a, and one end surface of the flange 205 b is a receiving surface (support surface) of the second compression coil spring 206. Become.
On the other hand, the other end surface of the flange 205b contacts the opening edge of the communication hole 207b2 when the pressure-sensitive rod 204 moves to the second space 221 side, and restricts the movement of the pressure-sensitive rod 204 to the second space 221 side. . That is, the movement of the pressure-sensitive rod 204 to the second space 221 side is restricted by the other end surface (moving end) of the flange 205b and the corresponding opening end edge of the communication hole 207b2 serving as a regulating surface on the valve housing side. A second stopper portion is configured.

The position where the other end surface of the flange 205b abuts against the opening edge of the communication hole 207b2 is the position where the pressure-sensitive rod 204 has moved most to the second space 221 side, and the pressure-sensitive rod 204 has moved most to the second space 221 side. By doing so, the support end of the first compression coil spring 202 comes closest to the valve seat 207a2.
Therefore, the position of the pressure-sensitive rod 204 where the other end surface of the flange 205b contacts the opening edge of the communication hole 207b2 is such that the biasing force of the first compression coil spring 202 biasing the valve body 201 in the valve closing direction is the maximum value f1max. At this time, when the following expressions (2) and (2 ′) are established, the valve body 201 is opened.
(PdH−PdL) · Sv−f1max> 0 (2)
PdH−PdL = ΔPdmax> f1max / Sv (2 ′)

In the equation (2 ′), ΔPdmax indicates the maximum value of the valve opening differential pressure of the check valve 200.
The maximum value ΔPdmax of the valve opening differential pressure is the maximum value of the variable range of the valve opening differential pressure that changes as the urging force of the first compression coil spring 202 changes depending on the position of the pressure sensitive rod 204. This is the valve opening differential pressure when the urging force of the first compression coil spring 202 is the maximum value f1max.

On the other hand, the force fr acting on the pressure-sensitive rod 204 is expressed by the following formula (3).
fr = f1-f2 + (PdL-Ps) .Sr ± f3 (3)
In Formula (3), f1 is an urging force of the first compression coil spring 202, f2 is an urging force of the second compression coil spring 206 (f2> f1 + f3), and f3 is a friction force mainly between the O-ring 210 and the pressure-sensitive rod 204. , Ps is the pressure in the suction chamber 141, and Sr is the cross-sectional area of the pressure-sensitive rod 204.

As described above, the pressure sensing rod 204 includes the pressure PdL in the discharge passage 104b downstream from the check valve 200 (valve body 201) (the refrigerant pressure on the high pressure side downstream from the check valve 200) and the suction chamber 141. Pressure Ps (the refrigerant pressure on the low-pressure side of the refrigeration apparatus 500) acts to displace in accordance with the differential pressure, and the support end of the first compression coil spring 202 in accordance with the displacement of the pressure-sensitive rod 204 Therefore, the biasing force of the first compression coil spring 202 changes, and the valve opening differential pressure of the check valve 200 changes.
That is, the pressure-sensitive rod 204, the second compression coil spring 206, the spring guide 203, the spring guide 205, the second member 207b, the third member 207c, and the communication hole 104d constitute an adjusting unit that adjusts the urging force of the first compression coil spring 202. .

As described above, the urging force f1 of the first compression coil spring 202, the urging force f2 of the second compression coil spring 206, and the frictional force f3 acting on the pressure-sensitive rod 204 are set to satisfy f2> f1 + f3.
Therefore, when the rotation of the variable capacity compressor 100 stops and the refrigerant circulation stops, and PdL = Ps (PdL−Ps = 0), fr <0, and as a result, the flange 205b of the spring guide 205 is The pressure-sensitive rod 204 moves to a position where it abuts against the two members 207b (opening edge of the communication hole 207b2), and the urging force of the first compression coil spring 202 reaches the maximum value f1max.

When the urging force of the first compression coil spring 202 reaches the maximum value f1max, the check valve 200 opens when PdH−PdL exceeds f1max / Sv, and the valve opening pressure difference ΔPd (valve opening pressure) ) Is the largest value ΔPdmax (see FIG. 6).
The maximum valve opening pressure ΔPdmax is a differential pressure “PdH−PdL” that is generated when the variable capacity compressor 100 is in a rotating state but is in a non-operating state where the refrigerant does not circulate through the refrigeration apparatus (a state below a predetermined discharge amount) Therefore, when the variable capacity compressor 100 is in a non-operating state, the check valve 200 is prevented from opening.

That is, when the variable capacity compressor 100 is switched from the non-operating state to the operating state, the valve opening differential pressure of the check valve 200 is the largest valve opening differential pressure ΔPdmax, and the difference depends on the operation of the variable capacity compressor 100. When the pressure “PdH−PdL” (the differential pressure across the valve body) increases and exceeds the valve opening differential pressure ΔPdmax, the check valve 200 opens.
When the check valve 200 is opened and the refrigerant circulates through the refrigeration apparatus 500, the pressure PdH in the discharge chamber 142 and the pressure in the discharge passage 104b downstream from the check valve 200 (valve body 201). While PdL increases, the pressure Ps in the suction chamber 141 decreases.

Here, when the pressure difference “PdL−Ps” acting on the pressure sensitive rod 204 increases and exceeds the predetermined value ΔPdsL, the pressure sensitive rod 204 moves to the third space 222 side, in other words, the valve seat 207a2. Start moving away from.
Accordingly, the biasing force f1 of the first compression coil spring 202 becomes smaller than the maximum value f1max, and the valve opening differential pressure of the check valve becomes smaller than the maximum differential pressure ΔPdmax (see FIG. 6).

When the differential pressure “PdL−Ps” continues to increase, the amount of displacement of the pressure sensitive rod 204 toward the third space 222 gradually increases, and the valve opening differential pressure of the check valve 200 relatively increases from the maximum value f1max. When the pressure gradually decreases and the differential pressure “PdL−Ps” reaches a predetermined value ΔPdsH, the movement of the pressure-sensitive rod 204 toward the third space 222 is finally regulated by the first stopper portion (spring guide 203). become.
At the position where the movement of the pressure sensitive rod 204 toward the third space 222 is restricted by the first stopper portion (spring guide 203), the urging force of the first compression coil spring 202 becomes the minimum value f1min, and the valve opening differential pressure ΔPd (valve opening pressure) becomes the smallest value ΔPdmin (see FIG. 6). In this state, the check valve 200 opens when the differential pressure “PdH−PdL” exceeds “f1min / Sv”.

Since the above equation (3) includes f3, that is, the influence of the frictional force of the O-ring 210, ΔPdsL and ΔPdsH have a width corresponding to the magnitude of the frictional force, and the differential pressure “ Hysteresis occurs in the characteristics of FIG. 6 in the direction in which “PdL−Ps” decreases and increases.
As described above, in the check valve 200, when the differential pressure between the high-pressure side refrigerant pressure and the low-pressure side refrigerant pressure downstream of the check valve 200, that is, “PdL−Ps” increases, the valve body 201 is increased. The urging force f1 of the first compression coil spring 202 that urges the valve in the valve closing direction is reduced, and when the differential pressure decreases, the urging force f1 of the first compression coil spring 202 is increased.

Therefore, in the operating state of the variable capacity compressor 100 in which the differential pressure “PdL−Ps” increases, the valve opening differential pressure of the check valve 200 becomes smaller than when the check valve 200 is not in operation, and performance degradation due to pressure loss is suppressed.
On the other hand, when the variable capacity compressor 100 is in an inoperative state, the discharge capacity of the variable capacity compressor 100 is in a minimum state, the differential pressure “PdL−Ps” is decreased, and the valve opening differential pressure of the check valve 200 is the maximum. The check valve 200 is stably held in the closed state.

  It should be noted that the variable displacement compressor 100 has a minimum discharge capacity, that is, the compressor 100 rotates and discharges refrigerant, but the check valve 200 has a pressure difference before and after the check valve 200 that is smaller than the valve opening differential pressure. In the non-operating state in which the valve 200 is closed, the refrigerant discharged into the discharge chamber 142 passes through the internal circulation path via the communication path 145, the crank chamber 140, the communication path 101c, the space 146, and the orifice 103c. It reaches the suction chamber 141, is again sucked into the cylinder bore 101 a and compressed, and circulates inside the variable capacity compressor 100.

The check valve (open / close valve) 200 shown in FIGS. 2 to 5 is provided integrally with the variable capacity compressor 100, but can be provided separately from the compressor. For example, FIG. As shown, the check valve 200 can be interposed in the high-pressure side pipe 900 that connects the variable capacity compressor 100 and the condenser 600.
When the check valve 200 is installed in the high-pressure side pipe 900, as shown in FIG. 8, a high pressure whose one end is connected to the discharge passage 104b of the variable capacity compressor 100 in the portion corresponding to the discharge chamber 142 in FIG. The other end of the side pipe 900a is connected, and the other end of the high-pressure side pipe 900b whose one end is connected to the inlet side of the condenser 600 is connected to the portion corresponding to the discharge passage 104b in FIG. The check valve 200 is interposed in the middle of the operation.

In the check valve 200, the refrigerant pressure on the low pressure side of the refrigeration apparatus 500 is set in a region in the accommodation hole 104 c around the third member 207 c that is separated from the region around the second member 207 b by the O-ring 209. One end of a low-pressure introduction pipe 250 for introduction is connected.
The other end of the low pressure introduction pipe 250 is the low pressure side pipe 910 on the low pressure side in the variable capacity compressor 100 such as the suction chamber 141 and the suction passage 104 a of the variable capacity compressor 100 or on the upstream side of the variable capacity compressor 100. Or the like to the low pressure side of the refrigeration apparatus 500.

  Accordingly, the check valve 200 interposed in the high-pressure side pipe 900 operates in the same manner as the check valve 200 provided integrally with the variable capacity compressor 100, and the operating state of the variable capacity compressor 100 (refrigerant circulation). In the state), the valve opening differential pressure of the check valve 200 is smaller than that in the non-operating state, and the performance deterioration due to the pressure loss is suppressed, while in the non-operating state of the variable capacity compressor 100 (refrigerant circulation stopping state) The valve opening differential pressure of the stop valve 200 becomes the maximum value, and the check valve 200 is stably held in the closed state.

Although the contents of the present invention have been specifically described with reference to the preferred embodiments, it is obvious that those skilled in the art can take various modifications based on the basic technical idea and teachings of the present invention. It is.
A high-pressure side space into which the high-pressure side refrigerant pressure downstream of the check valve 200 (open / close valve) is introduced and a low-pressure side space into which the low-pressure side refrigerant pressure of the refrigeration apparatus 500 is introduced define the difference. As the pressure-sensitive member that is displaced according to the pressure, a bellows or the like can be used in addition to the pressure-sensitive rod 204 described above.

Further, as a means for preventing leakage from the second space 221 to the third space 222 via the gap between the outer peripheral surface of the pressure-sensitive rod 204 and the communication hole 207b2, other than the O-ring 210, other Sealing means can be applied.
Further, the structure is not limited to the structure in which the outer periphery of the pressure-sensitive rod 204 is sealed by a sealing means such as an O-ring 210. For example, by sufficiently reducing the gap between the pressure-sensitive rod 204 and the insertion hole 207b2. , Sealing means such as an O-ring can be omitted.

Further, the pressure in the crank chamber 140 can be used as the low-pressure side refrigerant pressure to be applied to the pressure sensitive rod 204.
The check valve 200 of the above embodiment is an on-off valve that completely shuts off the discharge passage 104b (high-pressure side pipe 900). For example, when the valve body is seated on the valve seat, the check valve 200 is upstream and downstream of the valve body. A discharge variable throttle valve (open / close valve) in which the discharge passage 104b (the high-pressure side pipe 900) before and after the open / close valve is connected by the communication passage is provided.
Further, the compressor can be a compressor using an electromagnetic clutch in addition to a clutchless compressor, and can be a fixed capacity compressor in addition to a variable capacity, and further, a swash plate, a scroll, etc. The on-off valve (check valve) according to the present invention can be applied regardless of the type of the compression mechanism.

  DESCRIPTION OF SYMBOLS 100 ... Variable capacity compressor, 104b ... Discharge passage, 110 ... Drive shaft, 141 ... Suction chamber, 142 ... Discharge chamber, 200 ... Check valve (open / close valve), 201 ... Valve body, 202 ... First compression coil spring (with) 207 ... second compression coil spring (second urging member), 207 ... valve housing, 500 ... refrigeration device, 600 ... condenser, 204 ... pressure-sensitive rod (pressure-sensitive member, adjustment means), 206 ... second compression coil spring (second urging member) 700 ... Expansion valve, 800 ... Evaporator

Claims (9)

An on-off valve that is interposed in the high-pressure side refrigerant passage of the refrigeration apparatus and that opens and closes according to the differential pressure across the front and rear,
A biasing member that biases the valve body in the valve closing direction;
When the differential pressure between the refrigerant pressure on the high-pressure side downstream of the on-off valve and the refrigerant pressure on the low-pressure side of the refrigeration apparatus increases, the urging force of the urging member decreases, and when the differential pressure decreases, the urging member Adjusting means for increasing the urging force of
An opening / closing valve for a refrigeration apparatus. The urging member is an elastic body provided by being compressed between the valve body and a support end,
The open / close valve of the refrigerating apparatus according to claim 1, wherein the adjusting means changes the biasing force of the biasing member by displacing the position of the support end in the opening / closing direction of the valve body in accordance with the differential pressure. The adjusting means is
A high-pressure side space into which a high-pressure side refrigerant pressure downstream from the on-off valve is introduced and a low-pressure side space into which the low-pressure side refrigerant pressure of the refrigeration apparatus is introduced, are displaced according to the differential pressure. A pressure-sensitive member
The refrigeration apparatus according to claim 2, wherein an end of the pressure sensitive member on the high pressure refrigerant side is disposed so as to face the valve body, and an end of the pressure sensitive member on the high pressure refrigerant side is used as the support end. Open / close valve.   The on-off valve for the refrigeration apparatus according to claim 3, further comprising a stopper portion that limits a displaceable range of the pressure-sensitive member.   The on-off valve of the refrigeration apparatus according to claim 3 or 4, further comprising a second urging member that urges the pressure-sensitive member toward the high-pressure refrigerant side.   A compressor comprising the on-off valve according to any one of claims 1 to 5 in a discharge passage.   The refrigerant pressure on the high-pressure side downstream from the on-off valve is the pressure in the discharge passage downstream from the on-off valve, and the refrigerant pressure on the low-pressure side of the refrigeration apparatus is the pressure in the suction chamber of the compressor, The compressor according to claim 6.   A refrigerating apparatus comprising the on-off valve according to any one of claims 1 to 5 in a high-pressure side refrigerant passage between a compressor and a condenser. A compressor in which a check valve provided with a biasing member that biases the valve body in the valve closing direction is interposed in the discharge passage,
When the differential pressure between the pressure in the discharge passage downstream of the check valve and the pressure in the suction chamber of the compressor increases, the biasing force of the biasing member decreases, and when the differential pressure decreases, the biasing A compressor provided with adjusting means for increasing the biasing force of the member.