JP2013087863A - Pressure sensitive control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required until increasing discharge capacity of a variable capacity compressor just after activation of the compressor by enhancing a pressure sensitive control valve.SOLUTION: A crank chamber communication port 17 communicating a crank chamber side port 13 with a bellows accommodation chamber 2A is formed outside a guide hole 12 of a body case 1. A relief valve 31a is formed in a lower cover 31 of a bottom part of a pressure sensitive bellows 3 within the bellows accommodation chamber 2A. When performing capacity control operation of a compressor, the compressor is brought into a state where the relief valve 31a is inserted into a small diameter part 17a of the crank chamber communication port 17. When suction pressure Ps is high, the pressure sensitive bellows 3 is contracted and thereby the relief valve 31a is displaced to a large diameter part 17b of the crank chamber communication port 17 and the crank chamber communication port 17 is opened, and crank chamber pressure is relieved through the crank chamber communication port 17 to the bellows accommodation chamber 2A and a suction pressure side port 21.

Description

  The present invention relates to a pressure-sensitive control valve for controlling the capacity of a variable capacity compressor used for compressing a refrigerant in a refrigeration cycle such as an air conditioner for automobiles.

  Conventionally, a compressor used in a refrigeration cycle of an automotive air conditioner cannot be controlled in rotation speed because it is directly connected to an engine by a belt. Therefore, in order to obtain an appropriate cooling capacity without being restricted by the rotational speed of the engine, a variable capacity compressor capable of changing the capacity (discharge amount) of the compressor is used.

  In such a variable capacity compressor, generally, a rocking plate provided with a variable inclination angle is driven by a rotary motion of a rotating shaft in an airtight crank chamber to perform a rocking motion. The piston that reciprocates due to the rocking motion of the plate sucks the suction pressure into the cylinder, compresses it, discharges it, changes the pressure in the crank chamber, changes the tilt angle of the rocking plate, and reciprocates By changing the movement amount of the piston, the discharge amount of the refrigerant is changed.

  As a control valve for variably controlling the capacity of such a variable capacity compressor, for example, there is one disclosed in Japanese Patent Laid-Open No. 2000-88132 (Patent Document 1). The control valve of Patent Document 1 is a self-acting pressure-sensitive control valve that controls the capacity of the compressor by changing the open / close state of the valve by the expansion and contraction action of the pressure-sensitive bellows according to the suction pressure Ps of the compressor. is there.

JP 2000-88132 A

  Since the high pressure discharge pressure is supplied to the crank chamber of the variable capacity compressor (hereinafter also simply referred to as “compressor”), the higher the discharge flow rate of the refrigerant flowing from the crank chamber to the suction side, the more the compression is performed. The operating efficiency of the machine will deteriorate. For this reason, from the viewpoint of operating efficiency, in general, in a variable displacement compressor, the area of the crank chamber pressure discharge passage provided outside the pressure-sensitive control valve is small in a fixed state.

  On the other hand, if the compressor is stopped for a long time, for example, the refrigerant liquefies and stays in the crank chamber. When the compressor is started in a state where liquid refrigerant is accumulated in the crank chamber, the crank chamber pressure becomes excessive due to vaporization of the liquid refrigerant. At this time, since the outside air temperature is usually high, the suction pressure Ps is also high. For this reason, although the compressor must originally be loaded, the pressure in the crank chamber is not quickly discharged to the suction side only by the crank chamber pressure discharge passage, and the compressor is unloaded. As a result, there is a problem that it takes time for the discharge capacity to increase and it takes time for the inside of the vehicle to cool down.

  It is an object of the present invention to provide a pressure-sensitive control valve that can reduce the time required for the discharge capacity to increase immediately after the start of the variable displacement compressor.

  The pressure-sensitive control valve according to claim 1 has a pressure-sensitive bellows housed in a bellows housing chamber that communicates with a suction-pressure side port, and expands and contracts the pressure-sensitive bellows according to a change in the suction pressure of the compressor. The main valve member opens and closes the main valve port provided between the discharge pressure side port and the crank chamber side port, and the crank chamber pressure is adjusted by controlling the flow rate of refrigerant flowing into the crank chamber from the discharge side of the compressor In the pressure-sensitive control valve that controls the capacity of the compressor, a crank chamber communication port that connects the bellows storage chamber and the crank chamber side port is provided, and on the side of the bellows storage chamber of the crank chamber communication port, A relief valve that opens and closes the crank chamber communication port in conjunction with expansion and contraction of the pressure sensitive bellows is provided, and when the suction pressure is low, the relief valve is connected to the crank chamber communication port. Closed, and when the suction pressure is high, the main valve member closes the main valve port, the relief valve is characterized in that to open the crank chamber communicating port.

  The pressure-sensitive control valve according to claim 2 is the pressure-sensitive control valve according to claim 1, wherein the crank chamber communication port is formed outside the center of the main body case in which the main valve port is formed, The relief valve is formed at an end of the pressure sensitive bellows on the main body case side.

  The pressure-sensitive control valve according to claim 3 is the pressure-sensitive control valve according to claim 1, wherein the crank chamber communication port transmits the movement of the pressure-sensitive bellows to the valve portion of the main valve member. The relief valve is formed at the center of the end of the pressure sensitive bellows on the main body case side.

  The pressure-sensitive control valve according to claim 4 is the pressure-sensitive control valve according to claim 1, wherein the pressure-sensitive bellows is driven by driving a plunger connected to the opposite side of the main valve member of the pressure-sensitive bellows. An electromagnetic coil device that moves the valve to the valve closing side is provided.

  According to the pressure sensitive control valve of the first aspect, when the suction pressure is high, the crank chamber communication port is opened, so that even if the crank chamber pressure is excessive, the crank chamber pressure can be quickly released to the suction side. The discharge capacity of the compressor can be quickly increased.

  According to the pressure sensitive control valve of the second aspect, in addition to the effect of the first aspect, the crank chamber communication port and the relief valve are provided outside the main valve port. When the valve member is composed of a ball, a valve stem portion, and a valve body, it is possible to constitute a relief structure by the crank chamber communication port and the relief valve while maintaining a spherical connection at the contact point with the pressure-sensitive bellows by the ball. it can.

  According to the pressure-sensitive control valve of the third aspect, in addition to the effect of the first aspect, the crankcase communication port is formed in the valve stem portion that transmits the movement of the pressure-sensitive bellows to the valve portion. There is no need to form a crank chamber communication port.

  According to the pressure sensitive control valve of claim 4, in addition to the effect of claim 1, the compressor can be reliably unloaded by switching the electromagnetic coil device, and the compressor (air conditioner) can be turned on / off. Since it is not necessary to use a magnet clutch or the like for turning off, the compressor can be configured inexpensively and in a small size.

It is a longitudinal cross-sectional view of the fully open state of the pressure-sensitive control valve of 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the fully closed state of the pressure-sensitive control valve of 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the bellows most contracted state in the fully closed state of the pressure-sensitive control valve of the first embodiment of the present invention. It is a principal part expanded sectional view of the pressure-sensitive control valve of 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the fully open state of the pressure-sensitive control valve of 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the fully-closed state of the pressure-sensitive control valve of 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the bellows most contracted state in the fully closed state of the pressure-sensitive control valve of the second embodiment of the present invention. It is a principal part expanded sectional view of the pressure-sensitive control valve of 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the fully open state of the pressure-sensitive control valve of 3rd Embodiment of this invention. It is a longitudinal cross-sectional view of the fully closed state of the pressure-sensitive control valve of 3rd Embodiment of this invention. It is a longitudinal cross-sectional view of a bellows most contracted state in the fully closed state of the pressure-sensitive control valve of 3rd Embodiment of this invention. It is a figure which shows the other example of the relief valve of 2nd Embodiment and 3rd Embodiment of this invention.

  Next, an embodiment of the pressure-sensitive control valve of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of the pressure sensitive control valve of the first embodiment in a fully opened state, FIG. 2 is a longitudinal sectional view of the pressure sensitive control valve in a fully closed state, and FIG. FIG. 4 is an enlarged cross-sectional view of a main part of FIG. 3. 1 corresponds to the unload operation of the compressor, and FIGS. 2 and 3 correspond to the full load operation of the compressor.

  The pressure-sensitive control valve of the first embodiment forms a valve housing by a main body case 1 and a bellows case 2 that is caulked and coupled to the upper portion of the main body case 1. The main body case 1 and the bellows case 2 are formed by metal cutting or the like. The bellows case 2 has a large-diameter cylindrical shape, and an end portion thereof is caulked and joined to the main body case 1, and a bellows housing chamber 2A is formed therein. A pressure sensitive bellows 3 is disposed in the bellows storage chamber 2A. Further, a suction pressure side port 21 is formed in the side portion of the bellows case 2, and the suction pressure Ps of the compressor is introduced into the suction pressure side port 21.

  The pressure sensitive bellows 3 includes a lower cover 31, a lower end plate 32, a bellows body 33, a bellows cover 34, an adjustment spring 35, and a stopper pad 36. The lower end plate 32 and the bellows main body 33 are integrally formed, the bellows main body 33 is airtightly welded to the bellows cover 34, and the inside is a vacuum airtight chamber. An adjustment spring 35 is disposed in a compressed state between the stopper pad 36 and the bellows cover 34. Near the outer periphery of the lower cover 31, a pin-shaped relief valve 31 a that is inserted into a crank chamber communication port 17 described later is formed.

  A valve chamber 1A is formed on the opposite side of the main body case 1 from the bellows case 2. Between the valve chamber 1A and the bellows storage chamber 2A, a circular main valve port 11, a cylindrical guide hole 12 and A crank chamber side port 13 is formed. The crank chamber pressure Pc of the compressor is introduced into the crank chamber side port 13. A spring receiving member 14 that defines the valve chamber 1 </ b> A is caulked and coupled to the lower end portion of the main body case 1, and a discharge pressure side port 15 is formed in the spring receiving member 14. Also. A valve filter 16 is attached to the lower part of the main body case 1, and the discharge pressure Pd of the compressor is introduced into the valve chamber 1 </ b> A via the valve filter 16 and the discharge pressure side port 15.

  A ball-shaped main valve body 4 as a “valve portion” is provided in the valve chamber 1A. A valve stem portion 41 and a ball 42 are disposed on the main valve body 4, and the main valve body 4, the valve stem portion 41 and the ball 42 constitute a “main valve member”. The valve stem portion 41 and the ball 42 slidably penetrate the guide hole 12 formed in the main body case 1, and the upper end of the ball 42 slightly protrudes into the bellows housing chamber 2A. It is in contact with the bellows 3. The contact portion between the ball 42 and the pressure-sensitive bellows 3 is spherically connected, so that the accuracy of center positioning is increased. Further, the valve stem portion 41 serves to transmit the movement of the pressure sensitive bellows 3 to the main valve body 4. A ball receiver 43 is engaged with the main valve body 4, and a valve closing spring 44 for biasing the main valve body 4 in the valve closing direction (upward) is provided between the ball receiver 43 and the spring receiving member 14. It has been. The main valve body 4 is displaced up and down in the drawing to be seated and separated from the valve seat 11a to open and close the main valve port 11, and the main valve port 11 is opened from the discharge pressure side port 15 according to the valve lift. Then, the flow rate of the fluid flowing to the crank chamber side port 13 is quantitatively controlled (variable control).

  An adjustment screw 5 is attached to the upper part of the bellows case 2. A male screw portion 5 a is formed at the upper end portion of the adjustment screw 5, and this male screw portion 5 a is screwed into a female screw portion 2 a formed at the upper part of the bellows case 2. A ball 51 is engaged with the lower end of the adjusting screw 5. A straight cylindrical holding portion 34a is formed at the center of the bellows cover 34 of the pressure sensitive bellows 3, and the adjusting screw 5 and the ball 51 are fitted into the holding portion 34a.

  An annular groove 1a is formed in the bottom of the bellows accommodating chamber 2A, that is, the main body case 1 so as to surround the periphery of the guide hole 12, and the groove 1a is in contact with the lower cover 31 of the pressure sensitive bellows 3. The intermediate spring 6 is disposed in a compressed state so as to contact. Since the intermediate spring 6 biases the pressure-sensitive bellows 3 toward the adjustment screw 5, the pressure-sensitive bellows 3 is coupled to the adjustment screw 5. In addition, the spring force of the intermediate spring 6 is a spring force that is a maximum vibration resistance specification and does not vibrate the pressure-sensitive bellows 3.

  The main body case 1 is formed with a crank chamber communication port 17 that allows the bellows storage chamber 2A and the crank chamber side port 13 to communicate with each other at a plurality of locations (for example, four locations) outside the groove 1a. The crank chamber communication port 17 is composed of a small diameter portion 17a having a small diameter on the crank chamber side port 13 side and a large diameter portion 17b having a large diameter on the bellows storage chamber 2A side. A relief valve 31a formed on the lower cover 31 of the pressure sensitive bellows 3 can be inserted into the small diameter portion 17a through the large diameter portion 17b.

  With the above configuration, when the suction pressure Ps is low, as shown in FIG. 1, the pressure-sensitive bellows 3 extends with the adjustment screw 5 side as a fixed point, and the main valve body 4 contacts the lower end of the pressure-sensitive bellows 3. The ball 42 and the valve stem 41 are lowered to open the main valve port 11. As a result, the high pressure refrigerant flows from the discharge pressure side port 15 through the main valve port 11 to the crank chamber side port 13, the crank chamber becomes high pressure, and the compressor is unloaded. When the suction pressure Ps increases, the pressure-sensitive bellows 3 contracts with the adjustment screw 5 side as a fixed point, and the main valve body 4 is displaced in the valve closing direction by the urging force of the valve closing spring 44, as shown in FIG. When the main valve body 4 fully closes the main valve port 11, the crank chamber pressure Pc of the compressor becomes substantially equal to the suction pressure Ps, and the compressor is in full load operation. The amount of compression (compression load) of the pressure-sensitive bellows 3 is adjusted by adjusting the screwing amount of the adjusting screw 5. Thereby, the Ps setting (valve closing) pressure of the pressure-sensitive control valve is adjusted.

  Between the state shown in FIG. 1 and the state shown in FIG. The opening degree of the main valve port 11 is adjusted, and the compressor operates in capacity control. However, when the main valve body 4 opens the main valve port 11, the relief valve 31 a is a small diameter portion 17 a of the crank chamber communication port 17. The bellows storage chamber 2A and the crank chamber side port 13 are closed on the pressure sensitive control valve side. For this reason, the discharge pressure Pd does not flow into the bellows storage chamber 2A (suction side) via the crank chamber side port 13 during the capacity control operation of the compressor, and the operation efficiency of the compressor is not deteriorated.

  When the suction pressure Ps is further increased from the state of FIG. 2, the pressure-sensitive bellows 3 is further contracted as shown in FIG. 3, and the pressure-sensitive bellows 3 is separated from the ball 42, so that the main valve body 4 is connected to the main valve port. 11 is fully closed. Thereby, the full load operation of the compressor is maintained. At this time, the relief valve 31a is displaced in conjunction with the contraction of the pressure-sensitive bellows 3, and is displaced to the large diameter portion 17b of the crank chamber communication port 17, so that the crank chamber communication port 17 is opened, and the bellows housing chamber 2A. The crank chamber side port 13 is in communication.

  Here, for example, when the compressor is started in a state where the refrigerant is stopped for a long time and the refrigerant is liquefied and stays in the crank chamber, the crank chamber pressure becomes excessive due to the vaporization of the liquid refrigerant. At this time, since the suction pressure Ps is also high as described above, the pressure-sensitive control valve is in the state shown in FIG. 3, and the bellows storage chamber 2A and the crank chamber side port 13 are communicated with each other by the crank chamber communication port 17. It becomes a state. Then, as indicated by arrows in FIG. 4, the crank chamber pressure is changed from the crank chamber side port 13 through the small diameter portion 17b and the large diameter portion 17a of the crank chamber communication port 17 to the bellows accommodating chamber 2A and the suction pressure side port. Exit to 21. Therefore, the compressor can quickly shift to the road operation and cool the interior of the vehicle quickly.

  FIG. 5 is a longitudinal sectional view of the pressure sensitive control valve according to the second embodiment in a fully opened state, FIG. 6 is a longitudinal sectional view of the pressure sensitive control valve in a fully closed state, and FIG. FIG. 8 is an enlarged cross-sectional view of a main part of FIG. 7. 5 corresponds to the unload operation of the compressor, and FIGS. 6 and 7 correspond to the full load operation of the compressor. 5 to 8, the same elements as those in the first embodiment are denoted by the same reference numerals as those in FIGS. 1 to 4. In addition, since the structure and the effect of the element are as above-mentioned, the detailed description is abbreviate | omitted.

  In the second embodiment, a vertical hole 45a and a horizontal hole 45b are formed in the valve stem portion 45 in the guide hole 12 formed in the main body case 1, and the vertical hole 45a and the horizontal hole 45b are “crank chamber communication ports”. Is configured. The main valve body 4 and the valve stem portion 45 constitute a “main valve member”, and the valve stem portion 45 serves to transmit the movement of the pressure-sensitive bellows 3 to the main valve body 4. A ball-shaped relief valve 37a is disposed at the center of the lower cover 37 at the lower end of the pressure-sensitive bellows 3. The relief valve 37a is fixed to the lower cover 37 by welding or the like.

  With the above configuration, when the suction pressure Ps is low, as shown in FIG. 5, the pressure-sensitive bellows 3 extends with the adjustment screw 5 side as a fixed point, and the main valve body 4 is a relief valve at the lower end of the pressure-sensitive bellows 3. 37a, the valve stem portion 45 is lowered and the main valve port 11 is opened. As in the first embodiment, the high-pressure refrigerant flows from the discharge pressure side port 15 to the crank chamber side port 13 via the main valve port 11, and the compressor is unloaded. When the suction pressure Ps increases, the pressure-sensitive bellows 3 contracts with the adjustment screw 5 side as a fixed point, and the main valve body 4 is displaced in the valve closing direction by the urging force of the valve closing spring 44, as shown in FIG. When the main valve body 4 fully closes the main valve port 11, the crank chamber pressure Pc of the compressor becomes substantially equal to the suction pressure Ps, and the compressor is in full load operation.

  As in the first embodiment, the compressor operates in capacity control between the state of FIG. 5 and the state of FIG. 6, but when the main valve body 4 opens the main valve port 11, the relief valve 37 a The vertical hole 45a (crank chamber communication port) of the valve stem portion 45 is normally closed, and the space between the bellows storage chamber 2A and the crank chamber side port 13 is closed on the pressure sensitive control valve side. For this reason, the discharge pressure Pd does not flow into the bellows storage chamber 2A (suction side) via the crank chamber side port 13 during the capacity control operation of the compressor, and the operation efficiency of the compressor is not deteriorated.

  When the suction pressure Ps further increases, as shown in FIG. 7, the pressure-sensitive bellows 3 further contracts, the relief valve 37a is disconnected from the valve stem portion 45, and the main valve body 4 is fully closed. Maintain state. Thereby, the full load operation of the compressor is maintained. At this time, the relief valve 37a is displaced in conjunction with the contraction of the pressure-sensitive bellows 3, opens the vertical hole 45a of the valve stem portion 45, and bellows through the vertical hole 45a and the horizontal hole 45b (crank chamber communication port). The storage chamber 2A and the crank chamber side port 13 are communicated with each other.

  Similarly to the first embodiment, when the crank chamber pressure becomes excessive due to vaporization of the liquid refrigerant at the time of starting the compressor, the suction pressure Ps is also increased as described above. 7 and the bellows storage chamber 2A and the crank chamber side port 13 are communicated with each other by the vertical hole 45a and the horizontal hole 45b (crank chamber communication port). Therefore, as indicated by an arrow in FIG. 8, the crank chamber pressure is released from the crank chamber side port 13 through the horizontal hole 45b and the vertical hole 45a to the bellows storage chamber 2A and the suction pressure side port 21. It is possible to quickly shift to road driving and quickly cool the interior of the vehicle.

  9 is a longitudinal sectional view of the pressure sensitive control valve of the third embodiment in a fully opened state, FIG. 10 is a longitudinal sectional view of the pressure sensitive control valve in a fully closed state, and FIG. 11 is a bellows most fully closed state of the pressure sensitive control valve. It is a longitudinal cross-sectional view of a contracted state. 9 corresponds to the unload operation of the compressor, and FIGS. 10 and 11 correspond to the full load operation of the compressor. 9 to 11, the same elements as those in the first and second embodiments are denoted by the same reference numerals as those in FIGS. 1 to 8. In addition, since the structure and the effect of the element are as above-mentioned, the detailed description is abbreviate | omitted.

  In the pressure sensitive control valve of the third embodiment, a valve housing is constituted by a main body case 71 and a bellows case 72 that is caulked and coupled to the upper portion of the main body case 71. The main body case 71 is formed by metal cutting or the like. The bellows case 72 is formed by pressing a stainless steel (SUS) plate. The bellows case 72 has a large-diameter cylindrical shape and a bellows housing box 72a whose end is caulked and joined to the main body case 71, and a small-diameter cylindrical shape. The plunger case 72b is integrally formed. A lid 73 formed by pressing a stainless steel (SUS) plate is fitted and fixed to the outer periphery of the bellows case 72 (bellows housing box 72a). The electromagnetic coil device 10 is provided on the upper portion of the lid 73 and the outer periphery of the plunger case 72b.

  The bellows storage box 72a has a bellows storage chamber 72A formed therein, and the pressure sensitive bellows 3 is disposed in the bellows storage chamber 72A. Further, a suction pressure side port 721 is formed at the side of the bellows storage box 72a, and the suction pressure Ps of the compressor is introduced into the suction pressure side port 721.

  A valve chamber 71A is formed on the opposite side of the main body case 71 from the bellows case 72. Between the valve chamber 71A and the bellows storage chamber 72A, a circular main valve port 711, a cylindrical guide hole 712, and A crank chamber side port 713 is formed. The crank chamber pressure Pc of the compressor is introduced into the crank chamber side port 713. A spring receiving member 74 that defines a valve chamber 71 </ b> A is caulked and coupled to the lower end of the main body case 71, and a discharge pressure side port 75 is formed in the spring receiving member 74. Then, the discharge pressure Pd of the compressor is introduced into the valve chamber 71 </ b> A through the discharge pressure side port 75.

  In the valve chamber 71A, the main valve port 711, and the guide hole 712, a main valve member 76 in which a cylindrical valve portion 76a and a cylindrical rod-shaped valve stem portion 76b are integrally formed is provided. The valve stem portion 76b serves to transmit the movement of the pressure sensitive bellows 3 to the valve portion 76a. A flange portion is formed in the lower portion of the valve portion 76a, and a valve closing spring 77 for biasing the valve portion 76a in the valve closing direction (upward) is provided between the flange portion and the spring receiving member 74. Yes.

  A vertical hole 76b1 and a horizontal hole 76b2 are formed in the valve stem portion 76b, and the vertical hole 76b1 and the horizontal hole 76b2 constitute a “crank chamber communication port”. Similarly to the second embodiment, a ball-shaped relief valve 37a is disposed in the center of the lower cover 37 at the lower end of the pressure-sensitive bellows 3, and the relief valve 37a is welded to the lower cover 37 by welding or the like. It is fixed.

  The attractor 10a of the electromagnetic coil device 10 is fixed to the upper end portion of the plunger case 72b. A plunger 10b is disposed inside the plunger case 72b, and a plunger spring 10c is compressed and disposed between the plunger 10b and the suction element 10a. An electromagnetic coil 10d is provided on the outer periphery of the plunger case 72b, and the lower end surface of the attractor 10a becomes a magnetic attraction surface for the plunger 10b by excitation of the electromagnetic coil 10d. A cylindrical boss portion 10b1 at the end of the plunger 10b is fitted into the holding portion 34a of the bellows cover 34 of the pressure sensitive bellows 3. Further, the pressure-sensitive bellows 3 is urged toward the plunger 10 b by the intermediate spring 6. The combined force of the attractive force by the attractive element 10a with respect to the plunger 10b, the spring force of the valve closing spring 77, and the spring force of the intermediate spring 6 is set larger than the spring force of the plunger spring 10c. The spring force of the plunger spring 10 c is set to be greater than the combined force of the spring force of the valve closing spring 77 and the spring force of the intermediate spring 6.

  An adjusting screw 20 is disposed in the suction element 10a with its upper end screwed into the suction element 10a. The adjusting screw 20 has a rod portion 20a extending to the pressure-sensitive bellows 3 side, and this rod portion 20a extends into the bellows cover 34 of the pressure-sensitive bellows 3 through a through hole at the center of the suction element 10a and the plunger 10b. Yes. In the third embodiment, the compression amount (load) of the pressure-sensitive bellows 3 is adjusted by adjusting the screwing amount of the adjusting screw 20 when the electromagnetic coil device 10 is energized, and at the tip of the rod portion 20a of the adjusting screw 20. The bellows cover 34 is directly compressed to adjust the Ps setting (valve closing) pressure of the pressure-sensitive control valve.

  With the above configuration, when the electromagnetic coil device 10 is not energized (when not energized), as shown in FIG. 9, the plunger 10b is separated from the attractor 10a by the spring force of the plunger spring 10c. As a result, the lower side of the pressure-sensitive bellows 3 comes into contact with the bottom portion (main body case 71) of the bellows accommodating chamber 72A, and the main valve member 76 is positioned at the maximum valve open position. Even if the suction pressure Ps changes, the pressure-sensitive bellows 3 expands and contracts with the bottom of the bellows storage chamber 72A as a fixed point. Thereby, since the pressure-sensitive control valve can hold the maximum valve open position, the state of the unload operation of the compressor is reliably maintained by putting the pressure-sensitive control valve in a non-energized state.

  Further, when the electromagnetic coil device 10 is energized (excited), as shown in FIG. 10, the plunger 10b is attracted to the attractor 10a. In this state, when the suction pressure Ps decreases, the pressure-sensitive bellows 3 expands with the boss portion 10b1 side of the plunger 10b as a fixed point, and conversely, when the suction pressure Ps increases, the pressure-sensitive bellows 3 contracts with the boss portion 10b1 side as a fixed point. As a result, the main valve member 76 is displaced and the compressor is in a capacity control operation. However, when the valve portion 76a of the main valve member 76 opens the main valve port 711, the relief valve 37a is connected to the valve stem portion 76b. The vertical hole 76b1 (crank chamber communication port) is normally closed, and the bellows storage chamber 72A and the crank chamber side port 713 are closed on the pressure-sensitive control valve side. For this reason, the discharge pressure Pd does not flow into the bellows storage chamber 72A (suction side) via the crank chamber side port 713 during the capacity control operation of the compressor, and the operation efficiency of the compressor is not deteriorated.

  When the suction pressure Ps is further increased, as shown in FIG. 11, the pressure-sensitive bellows 3 further contracts, the relief valve 37a is disconnected from the valve stem portion 76b, and the main valve member 76 is fully closed by the main valve port 711. Maintain state. Thereby, the full load operation of the compressor is maintained. At this time, the relief valve 37a is displaced in conjunction with the contraction of the pressure-sensitive bellows 3, opens the vertical hole 76b1 of the valve stem portion 76b, and the bellows through the vertical hole 76b1 and the horizontal hole 76b2 (crank chamber communication port). The storage chamber 72A and the crank chamber side port 713 communicate with each other.

  Similarly to the second embodiment, if the crank chamber pressure becomes excessive due to vaporization of the liquid refrigerant at the time of starting the compressor, the suction pressure Ps is also increased as described above. 11 and the bellows storage chamber 72A and the crank chamber side port 713 are communicated with each other by the vertical hole 76b1 and the horizontal hole 76b2 (crank chamber communication port). Accordingly, the crank chamber pressure passes from the crank chamber side port 713 through the horizontal hole 76b2 and the vertical hole 76b1 to the bellows accommodating chamber 72A and the suction pressure side port 721, and the compressor immediately shifts to the load operation, and quickly moves through the vehicle interior. Can be cooled down.

  In the third embodiment, the compressor can be reliably unloaded by switching between energization / non-energization of the electromagnetic coil device 10. Therefore, since it is not necessary to use a magnet clutch or the like for turning on / off the compressor (air conditioner), the compressor can be configured inexpensively and in a small size.

  In the second and third embodiments, the relief valve 37a is fixed to the lower cover 37 by welding or the like. However, the present invention is not limited to this configuration, and the relief valve 37a is replaced with the lower cover 37, for example, as shown in FIG. A lower cover 38 may be provided at the lower end of the pressure-sensitive bellows 3. The lower cover 38 is formed by pressing a metal plate, and a protruding portion 38a as a “relief valve” is formed at the center. What is necessary is just to comprise so that the vertical hole 45a of the said valve stem part 45 or the vertical hole 76b1 of the said valve stem part 76b may be opened and closed by this protrusion part 38a, respectively.

DESCRIPTION OF SYMBOLS 1 Main body case 1A Valve chamber 11 Main valve port 12 Guide hole 13 Crank chamber side port 15 Discharge pressure side port 17 Crank chamber communication port 17a Small diameter portion 17b Large diameter portion 2 Bellows case 2A Bellows accommodation chamber 21 Suction pressure side port 3 For pressure sensing Bellows 31 Lower cover 31a Relief valve 4 Main valve body (valve part, main valve member)
41 Valve stem (main valve member)
42 Ball (Main valve member)
45 Valve stem 45a Vertical hole (Crank chamber communication port)
45b Side hole (Crank chamber communication port)
37 Lower cover 37a Relief valve 71 Body case 71A Valve chamber 711 Main valve port 712 Guide hole 713 Crank chamber side port 72 Bellows case 72A Bellows storage chamber 721 Suction pressure side port 75 Discharge pressure side port 76a Valve portion 76b Valve stem portion 76 Main Valve member 76b1 Vertical hole (Crank chamber communication port)
76b2 Horizontal hole (Crank chamber communication port)
DESCRIPTION OF SYMBOLS 10 Electromagnetic coil apparatus 10a Attractor 10b Plunger 10c Plunger spring 10d Electromagnetic coil 10b1 Boss part 38 Lower cover 38a Protrusion part (relief valve)

Claims (4)

A pressure sensitive bellows housed in a bellows housing chamber that communicates with the suction pressure side port, and the main valve member expands and contracts the pressure sensitive bellows in response to a change in the suction pressure of the compressor, The main valve port provided between the crank chamber side ports is opened and closed, and the flow rate of the refrigerant flowing into the crank chamber from the discharge side of the compressor is controlled to adjust the crank chamber pressure and control the compressor capacity. In the pressure control valve,
A crank chamber communication port that communicates the bellows storage chamber and the crank chamber side port is provided, and the crank chamber communication port is linked to the bellows storage chamber side of the crank chamber communication port in conjunction with expansion and contraction of the pressure sensitive bellows. Provide a relief valve to open and close
When the suction pressure is low, the relief valve closes the crank chamber communication port,
The pressure-sensitive control valve, wherein when the suction pressure is high, the main valve member closes the main valve port, and the relief valve opens the crank chamber communication port.   The crank chamber communication port is formed outside the center of the main body case where the main valve port is formed, and the relief valve is formed at the end of the pressure sensitive bellows on the main body case side. The pressure-sensitive control valve according to claim 1.   The crank chamber communication port is formed in a valve stem portion that transmits the movement of the pressure-sensitive bellows to the valve portion of the main valve member, and the relief valve is formed in the center of the end portion of the pressure-sensitive bellows on the main body case side. The pressure-sensitive control valve according to claim 1, wherein the pressure-sensitive control valve is provided.   2. The electromagnetic coil device according to claim 1, further comprising an electromagnetic coil device that drives a plunger connected to a side opposite to the main valve member of the pressure-sensitive bellows to move the pressure-sensitive bellows to a valve closing side. Pressure sensitive control valve.

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