JP5443444B2 - Pressure sensitive control valve - Google Patents

Description

  The present invention relates to a pressure-sensitive control valve for a variable displacement compressor used for compressing a refrigerant in a refrigeration cycle such as an automotive air conditioner.

  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 control valves for variably controlling the capacity of such a variable capacity compressor, for example, Japanese Patent Application Laid-Open No. 2001-193640 (Patent Document 1), Japanese Patent Application Laid-Open No. 2001-20857 (Patent Document 2) and Japanese Patent Application Laid-Open No. 11-280658. Is disclosed in Japanese Patent Publication (Patent Document 3). These control valves change 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, and control the capacity of the compressor. Patent documents 2 and 3 are external control valves, which are self-powered control valves, and change the suction pressure Ps at which the control valve opens according to the discharge pressure Pd of the compressor.

JP 2001-193640 A JP 2001-20857 A JP-A-11-280658

  In the control valve of Patent Document 1, the solenoid device is de-energized, and the compressor is unloaded (air conditioner OFF) with the valve closing spring fully closed between the suction pressure and the crank chamber pressure. Can do. However, the thing of this patent document 1 is an external control valve which energizes a solenoid device and controls the quantity of the current applied to this solenoid device when performing capacity control. That is, according to the structure of Patent Document 1, the ball valve body is fixed to the plunger side of the solenoid device, and the suction force (driving force in the valve opening direction) of the solenoid device and the driving in the valve closing direction by the bellows. Since the capacity control is performed based on the balance relationship with the force, the control of the solenoid device becomes complicated.

  On the other hand, the control valves of the cited documents 2 and 3 are self-powered control valves, and capacity control can be performed with a simple configuration. However, the compressor cannot be forced to be unloaded (air conditioner OFF). Note that the unload operation is performed when the suction pressure Ps falls below the set pressure set by the adjusting screw (when the valve is closed). For this reason, it is necessary to separately install a magnet clutch or the like in the drive part of the compressor in order to turn on / off the air conditioner.

  It is an object of the present invention to provide a pressure-sensitive control valve that can perform compressor capacity control by self-powered control, and can reliably perform a minimum capacity unload operation without using a magnet clutch or the like. Let it be an issue.

  The pressure-sensitive control valve according to claim 1 is in contact with a pressure-sensitive bellows disposed in a bellows accommodating chamber, one end of the pressure-sensitive bellows, and is displaced in the valve-closing direction via the pressure-sensitive bellows, and also a valve lift A valve member that variably sets the opening degree of the valve port formed between the inlet port and the outlet port according to the amount, a valve opening spring that urges the valve member in the valve opening direction, and the pressure-sensitive bellows. The valve member has a plunger connected to the other side, and a valve closing urging means for urging the pressure sensitive bellows in the valve closing direction via the plunger by energizing or de-energizing an electromagnetic coil. An electromagnetic drive unit, and the biasing force of the valve closing biasing means is set to be stronger than the biasing force of the valve opening spring, and when the valve closing biasing means of the electromagnetic drive unit is not operated, the bellows accommodating chamber Against changes in pressure When the pressure-sensitive bellows is expanded and contracted with the plunger side as a fixed point, the opening degree of the valve port is controlled by the valve member, and the valve closing urging means of the electromagnetic drive unit is operated, the valve closing urging The pressure-sensitive bellows is pressed by means to bring the valve port into a fully closed state, and the pressure-sensitive bellows is expanded and contracted with the valve member side as a fixed point in response to a change in pressure in the bellows storage chamber, The plunger is freely moved in conjunction with the expansion and contraction of the pressure sensitive bellows.

  The pressure-sensitive control valve according to claim 2 is in contact with a pressure-sensitive bellows disposed in a bellows accommodating chamber and one end of the pressure-sensitive bellows, and is displaced in the valve closing direction via the pressure-sensitive bellows. A valve member that variably sets the opening degree of the valve port formed between the inlet port and the outlet port according to the amount, a valve opening spring that urges the valve member in the valve opening direction, and the pressure-sensitive bellows. A plunger coupled to the other side of the valve member, a plunger spring for urging the plunger in the valve closing direction, and suctioning the plunger against the urging force of the plunger spring by energizing the electromagnetic coil And a biasing force of the plunger spring is set to be stronger than a biasing force of the valve opening spring, and the plunger is connected to the pressure-sensitive bellows when moving in the valve closing direction. The pressure-sensitive bellows is configured to contact only the pressure-sensitive bellows, and when the electromagnetic coil is energized, the plunger is attracted to the suction element, and the pressure-sensitive bellows is moved toward the plunger side in response to a change in pressure in the bellows storage chamber. The valve member is expanded and contracted as a fixed point, and the opening of the valve port is controlled by the valve member, and when the electromagnetic coil is not energized, the pressure-sensitive bellows is pressed through the plunger by the biasing force of the plunger spring. The valve port is fully closed, and the pressure sensitive bellows is expanded and contracted with the valve member side as a fixed point in response to a change in pressure in the bellows accommodating chamber, and the plunger is interlocked with the expansion and contraction of the pressure sensitive bellows. It is characterized in that the can be moved freely. The electromagnetic coil, the attractor, the plunger, and the plunger spring correspond to the “electromagnetic drive unit” in claim 1, and the plunger spring corresponds to the “valve closing biasing unit” in claim 1.

  The pressure-sensitive control valve according to claim 3 is in contact with a pressure-sensitive bellows disposed in the bellows accommodating chamber and one end of the pressure-sensitive bellows, and is displaced in the valve-closing direction via the pressure-sensitive bellows, A valve member that variably sets the opening degree of the valve port formed between the inlet port and the outlet port according to the amount, a valve opening spring that urges the valve member in the valve opening direction, and the pressure-sensitive bellows. A plunger coupled to the other side of the valve member via a connection guide, a plunger spring for urging the plunger in the valve opening direction, and energizing an electromagnetic coil against the urging force of the plunger spring. A suction element for sucking the plunger, and a suction force by the suction element is set stronger than a combined biasing force of the valve opening spring and the plunger spring, and the connection guide of the plunger is It is configured to contact only the pressure-sensitive bellows at the joint with the pressure-sensitive bellows when moving in the valve closing direction, and the plunger is attracted by the biasing force of the plunger spring when the electromagnetic coil is not energized. The pressure-sensitive bellows is expanded and contracted with the connecting guide side of the plunger as a fixed point with respect to a change in pressure in the bellows storage chamber, and the valve port is opened by the valve member. And when energizing the electromagnetic coil, the plunger is sucked toward the attractor, the pressure-sensitive bellows is pressed through the plunger connection guide, and the valve port is fully closed. The pressure-sensitive bellows is expanded and contracted with the valve member side as a fixed point in response to a change in pressure in the bellows chamber, and the pressure-sensitive bellows is expanded and contracted in advance. Wherein the plunger has to be freely moved. The electromagnetic coil, the attractor, the plunger, the coupling guide, and the plunger spring correspond to the “electromagnetic drive unit” in claim 1, and the attraction force between the attractor and plunger by the electromagnetic coil is “valve closing bias” in claim 1. Corresponds to “means”.

  The pressure-sensitive control valve according to claim 4 is the pressure-sensitive control valve according to claim 2 or 3, wherein an effective diameter of the pressure-sensitive bellows and a diameter of the valve port that opens and closes the valve body are set to be equal. It is characterized by being.

  The pressure-sensitive control valve according to claim 5 is the pressure-sensitive control valve according to claim 2, wherein the suction element has a guide part at one end, and the end part is screwed into the guide part of the suction element. An adjustment screw having a rod portion that passes through the suction element and the plunger and can be brought into contact with the pressure-sensitive bellows, and adjusts a screwing amount of the adjustment screw with respect to the guide portion to adjust the pressure-sensitive bellows. The compression amount can be adjusted.

  According to the pressure-sensitive control valve of the first aspect, the valve-closing bellows of the electromagnetic drive unit is actuated to press the pressure-sensitive bellows, and the valve port is fully closed by the valve member. Even if the suction pressure of the compressor introduced into the bellows housing chamber changes, the pressure-sensitive bellows expands and contracts with the valve member side as a fixed point, and the plunger only moves freely, so that the valve member is displaced. Therefore, the fully closed state can be maintained, and the compressor can be reliably unloaded. 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.

  According to the pressure sensitive control valve of claim 2, by deenergizing the electromagnetic coil, the pressure sensitive bellows is pressed by the biasing force of the plunger spring, and the valve port is fully closed by the valve member. Even if the suction pressure of the compressor introduced into the bellows housing chamber changes, the pressure-sensitive bellows expands and contracts with the valve member side as a fixed point, and the plunger only moves freely, so that the valve member is displaced. Therefore, the fully closed state can be maintained, and the compressor can be reliably unloaded. 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.

  According to the pressure sensitive control valve of claim 3, by energizing the electromagnetic coil, the pressure sensitive bellows is pressed by the attractive force between the attractor and the plunger, and the valve port is fully closed by the valve member. . Even if the suction pressure of the compressor introduced into the bellows housing chamber changes, the pressure-sensitive bellows expands and contracts with the valve member side as a fixed point, and the plunger only moves freely, so that the valve member is displaced. Therefore, the fully closed state can be maintained, and the compressor can be reliably unloaded. 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.

  According to the pressure sensitive control valve of claim 4, in addition to the effect of claim 2 or 3, the force due to the pressure sensitive bellows and the crank chamber pressure applied to the valve body is canceled, and the suction pressure received on the lower surface of the valve body The valve body opens and closes. Therefore, it accurately follows the change in suction pressure.

  According to the pressure sensitive control valve of claim 5, in addition to the effect of claim 2, the amount of compression of the pressure sensitive bellows can be adjusted by adjusting the screwing amount of the adjusting screw into the guide portion. Therefore, the power of the electromagnetic drive unit can be reduced and power saving can be achieved. In addition, the number of parts can be reduced and the cost can be reduced.

It is a longitudinal cross-sectional view at the time of the deenergization 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 when the pressure-sensitive control valve of the first embodiment of the present invention is not energized. It is a longitudinal cross-sectional view at the time of electricity supply 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 at the time of electricity supply of the pressure-sensitive control valve of 1st Embodiment of this invention. It is a longitudinal cross-sectional view at the time of the deenergization of the pressure-sensitive control valve of 2nd Embodiment of this invention. It is a longitudinal cross-sectional view at the time of electricity supply of the pressure-sensitive control valve of 2nd Embodiment of this invention. It is a longitudinal cross-sectional view at the time of electricity supply of the pressure-sensitive control valve of 3rd Embodiment of this invention. It is a longitudinal cross-sectional view of the bellows most contracted state at the time of electricity supply of the pressure-sensitive control valve of 3rd Embodiment of this invention. It is a longitudinal cross-sectional view at the time of the deenergization of the pressure-sensitive control valve of 3rd Embodiment of this invention. It is a longitudinal cross-sectional view of the bellows most contracted state when the pressure-sensitive control valve of the third embodiment of the present invention is not energized. It is a longitudinal cross-sectional view at the time of electricity supply of the pressure-sensitive control valve of 4th Embodiment of this invention. It is a longitudinal cross-sectional view at the time of the deenergization of the pressure-sensitive control valve of 4th Embodiment of this invention. It is a longitudinal cross-sectional view at the time of the deenergization of the pressure-sensitive control valve of 5th Embodiment of this invention. It is a longitudinal cross-sectional view at the time of electricity supply of the pressure-sensitive control valve of 5th 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 when the pressure sensitive control valve of the first embodiment is not energized, FIG. 2 is a longitudinal sectional view of the bellows most contracted when the pressure sensitive control valve is not energized, and FIG. FIG. 4 is a cross-sectional view of the bellows most contracted when the pressure-sensitive control valve is energized. 1 and 2 correspond to the compressor unload operation, FIG. 3 corresponds to the compressor capacity control operation, and FIG. 4 corresponds to the compressor full load operation.

  The pressure-sensitive control valve according to the first embodiment has a valve housing 3 including a valve housing body 1 and a bellows case 2 that is caulked and coupled to the upper portion of the valve housing body 1. A valve chamber 4 is formed on the bellows case 2 side of the valve housing body 1, and a cylindrical valve port 5 is formed from the bottom to the lower end side of the valve chamber 4. Further, the valve housing body 1 passes through the valve chamber 4 in the radial direction and passes through the suction pressure side port 6 as an “outlet port” into which the suction pressure Ps of the compressor is introduced, and the valve port 5 in the radial direction. Thus, a crank chamber side port 7 is formed as an “inlet port” into which the crank chamber pressure Pc of the compressor is introduced. Furthermore, a main body guide hole 8 is formed on the lower end side of the valve housing main body 1 so as to penetrate the valve port 5 and introduce the discharge pressure Pd of the compressor.

  A ball-shaped valve body 9 as a “valve member” is provided in the valve chamber 4. A pressure introducing tube 9a is joined to the valve body 9 by welding or the like, and the pressure introducing tube 9a is slidably inserted into the main body guide hole 8. As a result, the valve body 9 is displaced up and down in the figure, so that the valve body 5 is seated and separated with respect to the valve seat 10 around the opening of the valve port 5 to open and close the valve port 5 and crank according to the valve lift. The flow rate of the fluid flowing from the chamber side port 7 through the valve port 5 to the suction pressure side port 6 is quantitatively controlled (variable control). A valve opening spring 15 is provided around the pressure introduction pipe 9a in the valve port 5 to urge the valve body 9 in the valve opening direction (upward).

  In the valve housing 3, the valve housing body 1 and the bellows case 2 define a bellows accommodation chamber 13, and a pressure sensitive bellows 16 is disposed in the bellows accommodation chamber 13. The pressure-sensitive bellows 16 includes a lower end portion 17, a bellows main body 18, a stopper pad 22, a bellows cover 20, and an adjustment spring 21. The lower end 17 and the bellows main body 18 are integrally formed, and the bellows main body 18 is hermetically welded to the bellows cover 20, and a vacuum hermetic chamber 19 is defined therein. Further, an adjustment spring 21 is disposed in a compressed state between the stopper pad 22 and the bellows cover 20. The valve body 9 is in contact with the lower end portion 17 of the pressure-sensitive bellows 16 by the biasing force of the valve opening spring 15.

  A plunger case 31 of the electromagnetic coil device 30 is airtightly fixed to the upper part of the bellows case 2, and a guide 32 is airtightly fixed to the upper part of the plunger case 31. An adjusting screw 33 is disposed in the guide 32 with its upper end screwed into the guide 32. A suction element 34 is disposed in the plunger case 31 so as to contact the lower end of the adjustment screw 33. A plunger 35 is disposed inside the plunger case 31, and a plunger spring 36 is compressed between the plunger 35 and the suction element 34. A straight cylindrical holding portion 20a is formed at the center of the bellows cover 20 of the pressure-sensitive bellows 16, and a cylindrical boss portion 35A at the end of the plunger 35 is fitted into the holding portion 20a.

  The plunger 35 is formed with a communication passage 37 for communicating the gap on the side of the suction element 34 and the bellows accommodation chamber 13 to equalize the pressure on the side of the suction element 34 and the bellows accommodation chamber 13. As a result, the plunger 35 can smoothly slide in the plunger case 31 without being affected by the differential pressure. An electromagnetic coil 38 is provided on the outer peripheral portion of the plunger case 31, and the lower end surface of the attractor 34 becomes a magnetic attraction surface for the plunger 35 by excitation of the electromagnetic coil 38.

  With the above configuration, when the electromagnetic coil device 30 is not energized (not energized), the plunger 35 is separated from the attractor 34 by the spring force of the plunger spring 36 as shown in FIG. The pressure-sensitive bellows 16 and the valve body 9 are positioned at the lower end by the spring force, and the valve body 9 is seated on the valve seat 10 to be fully closed. Accordingly, the supply of the crank chamber pressure Pc to the suction pressure side port 6 is stopped, and the crank chamber pressure Pc of the compressor rises due to the discharge pressure Pd flowing from the gap between the pressure introduction pipe 9a and the main body guide hole 8, The compressor enters an unload operation state.

Here, the spring force F of the plunger spring 36 and the spring force f of the valve opening spring 15 are set so as to satisfy a relationship of F> f. Further, the discharge pressure Pd is introduced into the lower surface of the valve body 9 from the hollow portion of the pressure introduction pipe 9a, and the valve body 9 is urged in the valve opening direction by the pressing force due to the differential pressure between the discharge pressure Pd and the suction pressure Ps. The When the pressure receiving area of the lower surface of the valve body 9 is A, this pressing force is A × (Pd−Ps). Therefore, when the valve port effective area of the valve port 5 is B and the maximum differential pressure between the crank chamber pressure Pc and the suction pressure Ps acting on the valve port is ΔPm, the spring force F of the plunger spring 36 is F> (f + B If a spring such that × ΔPm + A × (Pd−Ps) is selected, the pressure-sensitive control valve is fully closed within the specification ranges of the maximum discharge pressure Pd, the maximum crank chamber pressure Pc, and the minimum suction pressure Ps. Since it can be maintained, unload operation when the pressure-sensitive control valve is not energized is more reliably ensured.

  Since the spring force of the plunger spring 36 is set to be larger than the spring force of the valve opening spring 15, even when the suction pressure Ps changes, the lower end 17 is in contact with the valve body 9, that is, Only the expansion and contraction of the pressure-sensitive bellows 16 and the displacement of the plunger 35 occur while the valve body 9 is kept fully closed. For example, even if the suction pressure Ps is increased, the plunger 35 is merely displaced in the direction away from the suction element 34 until the bellows cover 20 contacts the stopper pad 22 as shown in FIG. . That is, the pressure-sensitive bellows 16 expands and contracts with the valve body 9 side (valve member side) as a fixed point. Thereby, since the pressure-sensitive control valve can maintain the fully closed state, the state of unloading operation of the compressor is reliably maintained by setting the pressure-sensitive control valve to the non-energized state.

  On the other hand, when the electromagnetic coil device 30 is energized (excited), the plunger 35 is attracted to the attractor 34 against the spring force of the plunger spring 36 as shown in FIG. In this state, when the internal pressure (suction pressure Ps) of the bellows storage chamber 13 decreases, the pressure-sensitive bellows 16 expands with the plunger 35 side as a fixed point, and conversely, when the suction pressure Ps increases, the pressure-sensitive bellows 16 Shrink using the 35 side as a fixed point. Thereby, the valve body 9 is displaced, and the compressor is in a capacity control operation. When the suction pressure Ps is further increased and the pressure-sensitive bellows 16 is further contracted, the valve body 9 opens the valve port 5 as shown in FIG. Accordingly, the crank chamber pressure Pc of the compressor becomes substantially equal to the suction pressure Ps, and the full load operation is performed.

  In the first embodiment described above, the plunger 35 and the pressure-sensitive bellows 16 are mechanically separated from each other and are in contact with each other. The plunger 35 and the valve-opening spring 15 are used to connect the plunger 35 and the pressure-sensitive bellows 16. The urging is performed in the direction in which they abut against each other. As a result, the pressure-sensitive bellows 16 is displaced integrally with the plunger 35. However, the pressure-sensitive bellows and the plunger may be mechanically fixed.

  5 and 6 are longitudinal sectional views of the pressure-sensitive control valve according to the second embodiment configured as described above. FIG. 5 shows a non-energized state, and FIG. 5 and 6, the same elements as those in the first embodiment are denoted by the same reference numerals as those in FIGS. 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, the bellows cover 20 of the pressure-sensitive bellows 16 is fixed to the cylindrical boss portion 35 </ b> B at the lower end of the plunger 35. That is, the plunger 35 and the pressure-sensitive bellows 16 are mechanically fixed by caulking a substantially cylindrical holding portion 20b into which the boss portion 35B is fitted at the center of the bellows cover 20 at the position of the concave portion 35a around the boss portion 35B. Are caulked and combined. Thereby, the plunger 35 and the bellows cover 20 move integrally.

  In the second embodiment, the valve housing main body 1 is formed with a large-diameter valve port 5 a on the bellows accommodating chamber 13 side of the valve port 5. And the valve body 12 as a "valve member" which opens and closes this large diameter valve port 5a is provided. The valve body 12 has a disk-like shape, and a stopper pad 22 of the pressure-sensitive bellows 16 is fixed to the central boss portion 12A. That is, the boss portion 12A is fitted in the center of the stopper lever 22, and the valve body 12 and the pressure-sensitive bellows 16 are mechanically caulked and joined by caulking at the position of the recess 12a around the boss portion 12A. Yes. As a result, the valve body 12 and the stopper pad 22 move together. In the pressure sensitive bellows 16 of the second embodiment, the bellows body 18 and the stopper metal 22 are joined by welding.

  In the second embodiment, the suction pressure side port 6 is formed in the lower part of the valve housing body 1, and the crank chamber side port 7 is formed in the bellows case 2. A pressure introducing pipe 11 is fixed to the shaft hole 11 a on the lower end side of the valve housing body 1, and an upper portion of the pressure introducing pipe 11 is slid into a guide hole 12 b formed in the boss portion 12 A of the valve body 12. It is inserted in a movable manner. As a result, the valve body 12 is displaced up and down in the drawing, so that the valve body 12 is seated and separated from the valve seat 10 around the opening of the large diameter valve port 5a to open and close the large diameter valve port 5a, and the valve lift Accordingly, the flow rate of the fluid flowing from the crank chamber side port 7 through the valve port 5 to the suction pressure side port 6 is quantitatively controlled (variable control).

  When the electromagnetic coil device 30 is not energized (not energized), as shown in FIG. 5, the pressure-sensitive bellows 16 and the valve body 12 are positioned at the lower end by the spring force of the plunger spring 36, and the valve body 12 is in the valve seat. 10 and fully closed. Accordingly, the supply of the crank chamber pressure Pc to the suction pressure side port 6 is stopped, and the crank chamber pressure Pc of the compressor is caused by the discharge pressure Pd flowing from the gap between the pressure introduction pipe 11 and the guide hole 12b of the valve body 12. Ascending, the compressor enters an unload operation state. Further, since the spring force of the plunger spring 36 is set larger than the spring force of the valve opening spring 15 as in the first embodiment, the fully closed state of the valve body 12 is maintained even if the suction pressure Ps changes. Is done. That is, the pressure-sensitive bellows 16 expands and contracts with the valve body 12 side (valve member side) as a fixed point, and the pressure-sensitive control valve can maintain a fully closed state. The state of unloading operation is reliably maintained.

  On the other hand, when the electromagnetic coil device 30 is energized (excited), as shown in FIG. 6, the plunger 35 is attracted to the attractor 34, and the internal pressure (suction pressure Ps) of the bellows storage chamber 13 decreases. The pressure-sensitive bellows 16 extends with the plunger 35 side as a fixed point. Conversely, when the suction pressure Ps increases, the pressure-sensitive bellows 16 contracts with the plunger 35 side as a fixed point. Thereby, the valve body 12 is displaced, and the compressor is in a capacity control operation. When the suction pressure Ps is increased and the valve body 12 fully opens the large-diameter valve port 5a, the crank chamber pressure Pc of the compressor becomes substantially equal to the suction pressure Ps, and the full load operation is performed.

  In the second embodiment, the effective diameter φDb of the pressure-sensitive bellows 16 and the diameter φD of the large-diameter valve port 5a are set equal. As a result, the force due to the pressure sensitive bellows 16 and the crank chamber pressure Pc applied to the valve body 12 is canceled, and the valve body 12 is opened and closed by the suction pressure Ps received on the lower surface of the valve body 12. Therefore, it accurately follows the change in the suction pressure Ps.

  FIG. 7 is a longitudinal sectional view when the pressure sensitive control valve of the third embodiment is energized, FIG. 8 is a longitudinal sectional view of the bellows most contracted when the pressure sensitive control valve is energized, and FIG. 9 is a non-energized state of the pressure sensitive control valve. FIG. 10 is a cross-sectional view of the bellows most contracted when the pressure-sensitive control valve is not energized. 7 and 8 correspond to the compressor unload operation, FIG. 9 corresponds to the compressor capacity control operation, and FIG. 10 corresponds to the compressor full load operation. In FIGS. 7 to 10 of the third embodiment, the same elements as those of the first embodiment are denoted by the same reference numerals as those of FIGS. 1 to 4, and the structure, operation and effect of the elements are as described above. The overlapping description is omitted.

  In the pressure-sensitive control valve of the third embodiment, a straight cylindrical holding portion 20c is formed at the center of the bellows cover 20 as in the first embodiment, and a later-described connection guide is provided in the holding portion 20c. A cylindrical boss 55A at the end of 55 is fitted.

  The upper part of the bellows case 2 is formed as a substantially cylindrical suction element 51. A plunger case 52 of the electromagnetic coil device 50 is fixed to the attractor 51 in an airtight manner. A plunger 53 is disposed inside the plunger case 52, and a plunger spring 54 is compressed and disposed between the plunger 53 and the suction element 51. A through hole 51a is formed at the center of the suction element 51, and a rod-like connection guide 55 is inserted into the through hole 51a with a gap so as not to contact the through hole 51a. The upper end of the connection guide 55 is fixed to the plunger 53, and the cylindrical boss portion 55A at the lower end is fitted into the bellows cover 20 of the pressure-sensitive bellows 16 as described above.

  In addition, the plunger 53 is formed with a clearance on the side of the suction element 51 and a communication passage 53a that allows the end of the plunger 53 and the space of the plunger case 52 to communicate with each other. The plunger 53 is smooth without being affected by the differential pressure. The plunger case 52 is slidable. An electromagnetic coil 56 is provided on the outer periphery of the plunger case 52, and the upper surface of the attractor 51 becomes a magnetic attraction surface for the plunger 53 by excitation of the electromagnetic coil 56. As shown in FIG. 9, when the electromagnetic coil 56 is not energized, the dimension L1 of the gap between the attractor 51 and the plunger 53 is set larger than the dimension L2 of the gap between the bellows cover 20 and the stopper pad 22. Yes. Further, the suction force by the suction element 51 is set larger than the combined spring force of the valve opening spring 15 and the plunger spring 54.

  With the above configuration, when the electromagnetic coil device 50 is energized (excited), the plunger 53 is attracted toward the attractor 51 against the spring force of the plunger spring 54 as shown in FIG. 16 and the valve body 9 are positioned at the lower end, and the valve body 9 is seated on the valve seat 10 to be fully closed. Accordingly, the supply of the crank chamber pressure Pc to the suction pressure side port 6 is stopped, and the crank chamber pressure Pc of the compressor rises due to the discharge pressure Pd flowing from the gap between the pressure introduction pipe 9a and the main body guide hole 8, The compressor enters an unload operation state. Since the suction force between the suction element 51 and the plunger 53 is set to be larger than the spring force of the valve opening spring 15, even if the suction pressure Ps changes, the fully closed state of the valve body 9 is maintained. Only the expansion and contraction of the pressure-sensitive bellows 16 and the displacement of the plunger 53 (and the connection guide 55) occur. For example, as shown in FIG. 8, in the most contracted state where the bellows cover 20 is in contact with the stopper pad 22, the plunger 53 is only displaced in the direction away from the suction element 51. That is, the pressure sensitive bellows 16 expands and contracts with the valve body 9 side as a fixed point. Thereby, since the pressure-sensitive control valve can maintain the fully closed state, the state of the unload operation of the compressor is reliably maintained by setting the pressure-sensitive control valve to the energized state.

  On the other hand, when the electromagnetic coil device 50 is not energized (when de-energized), the plunger 53 is separated from the attractor 51 by the spring force of the plunger spring 54 as shown in FIG. Abut. In this state, when the internal pressure (suction pressure Ps) of the bellows storage chamber 13 decreases, the pressure-sensitive bellows 16 extends with the boss portion 55A side of the connection guide 55 as a fixed point, and conversely, when the suction pressure Ps increases. The bellows 16 contracts with the boss 55A side as a fixed point, as described above. Thereby, the valve body 9 is displaced, and the compressor is in a capacity control operation. When the suction pressure Ps is further increased and the pressure-sensitive bellows 16 is further contracted, the valve body 9 opens the valve port 5 as shown in FIG. Accordingly, the crank chamber pressure Pc of the compressor becomes substantially equal to the suction pressure Ps, and the full load operation is performed.

  FIG. 11 is a longitudinal sectional view when the pressure sensitive control valve of the fourth embodiment is energized, and FIG. 12 is a longitudinal sectional view when the pressure sensitive control valve is not energized. 11 corresponds to the unloading operation of the compressor, and FIG. 12 corresponds to the capacity control operation of the compressor. In FIG. 11 and FIG. 12 of the fourth embodiment, the same elements as those of the second and third embodiments are denoted by the same reference numerals as those of FIG. 5 and FIG. As described above, redundant description is omitted.

  The fourth embodiment is a combination of the structures of the second embodiment and the third embodiment. The connection guide 55, the bellows cover 20, the valve body 12, and the stopper pad 22 fixed to the plunger 53 are respectively provided. Mechanically caulked and combined. Further, when the electromagnetic coil 56 is not energized, the dimension L1 of the gap between the attractor 51 and the plunger 53 is set larger than the dimension L2 of the gap between the bellows cover 20 and the stopper pad 22. Note that the effective diameter of the pressure-sensitive bellows 16 and the diameter of the large-diameter valve port 5a are set to be equal, and the force due to the pressure-sensitive bellows 16 and the crank chamber pressure Pc applied to the valve body 12 is cancelled. The valve body 12 is opened and closed by the received suction pressure Ps.

  When the electromagnetic coil device 50 is energized (excited), as shown in FIG. 11, the plunger 53 is attracted toward the attractor 51, the valve body 12 is positioned at the lower end, and the valve body 12 is seated on the valve seat 10. Then, it is in a fully closed state. Accordingly, the supply of the crank chamber pressure Pc to the suction pressure side port 6 is stopped, and the crank chamber pressure Pc of the compressor is caused by the discharge pressure Pd flowing from the gap between the pressure introduction pipe 11 and the guide hole 12b of the valve body 12. Ascending, the compressor enters an unload operation state. Since the suction force between the suction element 51 and the plunger 53 is set to be larger than the spring force of the valve opening spring 15, even if the suction pressure Ps changes, the fully closed state of the valve body 12 is maintained. Only the expansion and contraction of the pressure-sensitive bellows 16 and the displacement of the plunger 53 (and the connection guide 55) occur. That is, the pressure sensitive bellows 16 expands and contracts with the valve body 12 side as a fixed point. Thereby, since the pressure-sensitive control valve can maintain the fully closed state, the state of the unload operation of the compressor is reliably maintained by setting the pressure-sensitive control valve to the energized state.

  On the other hand, when the electromagnetic coil device 50 is not energized (when not energized), the plunger 53 comes into contact with the inner end of the plunger case 52 by the spring force of the plunger spring 54 as shown in FIG. In this state, when the internal pressure (suction pressure Ps) of the bellows storage chamber 13 decreases, the pressure-sensitive bellows 16 extends with the boss portion 55A side of the connection guide 55 as a fixed point, and conversely, when the suction pressure Ps increases. The bellows 16 contracts with the boss 55A side as a fixed point, as described above. Thereby, the valve body 12 is displaced, and the compressor is in a capacity control operation. When the suction pressure Ps further increases and the pressure-sensitive bellows 16 further contracts, the valve body 12 fully opens the large-diameter valve port 5a, and the crank chamber pressure Pc of the compressor becomes a pressure substantially equal to the suction pressure Ps. Full load operation.

  FIG. 13 is a longitudinal sectional view when the pressure sensitive control valve of the fifth embodiment is not energized, and FIG. 14 is a longitudinal sectional view when the pressure sensitive control valve is energized. FIG. 13 corresponds to the unloading operation of the compressor, and FIG. 14 corresponds to the capacity control operation of the compressor. In FIGS. 13 and 14 of the fifth embodiment, the same elements as those of the first embodiment are denoted by the same reference numerals as those of FIGS. 1 and 3, and the structure, operation and effect of the elements are as described above. The overlapping description is omitted.

  The fifth embodiment is an improvement of the Ps pressure setting mechanism in the pressure-sensitive control valve during the capacity control operation in the configuration of the first embodiment. A suction element 34 ′ having a structure in which the guide 32 and the suction element 34 in the first embodiment are integrated is provided. The suction element 34 ′ has a guide part 34 a ′ at the upper part, and is airtightly fixed to the upper part of the plunger case 31 at the lower part of the guide part 34 a ′. An adjusting screw 33 'is disposed in the suction element 34' with its upper end screwed to the guide portion 34a '. The adjustment screw 33 ′ has a rod portion 33 a ′ extending toward the pressure-sensitive bellows 16, and this rod portion 33 a ′ passes through a through hole 34 b ′ in the center of the suction element 34 ′ and a through hole 35 b in the center of the plunger 35. The pressure-sensitive bellows 16 extends into the bellows cover 20.

  Also in the fifth embodiment, when the electromagnetic coil device 30 is not energized (not energized), the plunger 35 is separated from the attractor 34 'by the spring force of the plunger spring 36 as shown in FIG. Then, the pressure-sensitive bellows 16 and the valve body 9 are positioned at the lower end, and the valve body 9 is seated on the valve seat 10 to be fully closed. Accordingly, the supply of the crank chamber pressure Pc to the suction pressure side port 6 is stopped, and the crank chamber pressure Pc of the compressor rises due to the discharge pressure Pd flowing from the gap between the pressure introduction pipe 9a and the main body guide hole 8, The compressor enters an unload operation state. Further, when the electromagnetic coil device 30 is energized (excited), as shown in FIG. 14, the plunger 35 is attracted to the attractor 34 ', and the internal pressure (suction pressure Ps) of the bellows storage chamber 13 is lowered. The pressure-sensitive bellows 16 extends with the plunger 35 side as a fixed point. Conversely, when the suction pressure Ps increases, the pressure-sensitive bellows 16 contracts with the plunger 35 side as a fixed point. Thereby, the valve body 9 is displaced, and the compressor is in a capacity control operation. When the suction pressure Ps is increased and the valve body 9 fully opens the valve port 5, the crank chamber pressure Pc of the compressor becomes substantially equal to the suction pressure Ps, and the full load operation is performed.

  Here, in the first embodiment, the adjustment screw 33 is screwed into the guide 32, the pressure sensitive bellows 16 is compressed by the plunger 35 via the suction element 34, and the pressure sensitive control valve is opened at a specified Ps pressure. In addition, the compression amount (load) of the pressure-sensitive bellows 16 is adjusted. In this case, since the gap dimension between the guide 32 and the attraction element 34 changes depending on the screwing amount of the adjusting screw 33, the coil attraction force at the time of energization varies, and the power of the electromagnetic coil device 30 has a margin for that. It is necessary to have it.

  In contrast, in the fifth embodiment, the adjustment screw 33 'is screwed into the suction element 34' to adjust the Ps pressure of the pressure-sensitive control valve, that is, the compression amount (load) of the pressure-sensitive bellows 16, and the adjustment screw. The amount of screwing of 33 ′ into the guide portion 34a ′ is adjusted, and the bellows cover 20 is directly compressed at the tip of the rod portion 33a ′. As shown in FIG. 14, at the time of this adjustment, assuming that the total length of the plunger 35 is L3 and the dimension from the lower end of the suction element 34 'to the plunger contact surface of the bellows cover 20 is L4, the relationship L3≤L4 is established. The dimensions of the plunger 35 and the adjustment screw 33 'and the load of the pressure-sensitive bellows 16 (the load of the bellows body 18 and the adjustment spring 21) are set. During the unloading operation (when not energized), the pressure-sensitive bellows 16 is urged in the valve closing direction via the plunger 35 by the spring force of the plunger spring 36, and the valve port 5 is fully closed.

  Therefore, according to the fifth embodiment, since the variation in the attractive force at the time of energization is reduced, the power of the electromagnetic coil device 30 can be reduced, and the power can be saved. Further, the number of parts can be reduced, and the cost can be reduced.

1 Valve housing body 2 Bellows case 3 Valve housing 5 Valve port 6 Suction pressure side port (outlet port)
7 Crank chamber side port (inlet port)
9,12 Valve body (valve member)
DESCRIPTION OF SYMBOLS 10 Valve seat 13 Bellows accommodation chamber 15 Valve opening spring 16 Pressure-sensitive bellows 30, 50 Electromagnetic coil devices 34, 34 ', 51 Suction element 35, 53 Plunger 36, 54 Plunger spring 31, 52 Plunger case 55 Connection guide

Claims (5)

A pressure sensitive bellows disposed in the bellows containing chamber;
Abutting with one end of the pressure-sensitive bellows, being displaced in the valve closing direction via the pressure-sensitive bellows, the opening degree of the valve port formed between the inlet port and the outlet port according to the valve lift amount A valve member to be variably set;
A valve opening spring for urging the valve member in a valve opening direction;
A plunger connected to the other side of the valve member of the pressure-sensitive bellows, and a valve closing mechanism that urges the pressure-sensitive bellows in the valve-closing direction via the plunger by energizing or de-energizing an electromagnetic coil. An electromagnetic drive having a biasing means;
With
The biasing force of the valve closing biasing means is set stronger than the biasing force of the valve opening spring,
When the valve closing urging means of the electromagnetic drive unit is not operated, the pressure sensitive bellows is expanded and contracted with the plunger side as a fixed point with respect to a change in pressure in the bellows storage chamber, and the valve port is formed by the valve member. Control the opening of
When the valve-closing urging means of the electromagnetic drive unit is operated, the valve-sensing bellows are pressed by the valve-closing urging means to fully close the valve port, and the pressure in the bellows accommodating chamber is changed. In contrast, the pressure sensitive control valve is characterized in that the pressure sensitive bellows is expanded and contracted with the valve member side as a fixed point, and the plunger is freely moved in conjunction with the expansion and contraction of the pressure sensitive bellows. A pressure sensitive bellows disposed in the bellows containing chamber;
Abutting with one end of the pressure-sensitive bellows, being displaced in the valve closing direction via the pressure-sensitive bellows, the opening degree of the valve port formed between the inlet port and the outlet port according to the valve lift amount A valve member to be variably set;
A valve opening spring for urging the valve member in a valve opening direction;
A plunger coupled to the other side of the valve member of the pressure sensitive bellows;
A plunger spring for urging the plunger in the valve closing direction;
An attractor for attracting the plunger against the biasing force of the plunger spring by energizing the electromagnetic coil;
With
The biasing force of the plunger spring is set to be stronger than the biasing force of the valve-opening spring, and the plunger is brought into contact with only the pressure-sensitive bellows at the coupling portion with the pressure-sensitive bellows when moving in the valve closing direction. Configured,
When energizing the electromagnetic coil, the plunger is attracted to the attractor, and the pressure-sensitive bellows is expanded and contracted with the plunger side as a fixed point in response to a change in pressure in the bellows storage chamber, and the valve member Control the opening of the valve port,
When the electromagnetic coil is not energized, the pressure-sensitive bellows are pressed through the plunger by the biasing force of the plunger spring to fully close the valve port, and the pressure in the bellows chamber is changed. A pressure-sensitive control valve, wherein the pressure-sensitive bellows is expanded and contracted with the valve member side as a fixed point, and the plunger is freely moved in conjunction with expansion and contraction of the pressure-sensitive bellows. A pressure sensitive bellows disposed in the bellows containing chamber;
Abutting with one end of the pressure-sensitive bellows, being displaced in the valve closing direction via the pressure-sensitive bellows, the opening degree of the valve port formed between the inlet port and the outlet port according to the valve lift amount A valve member to be variably set;
A valve opening spring for urging the valve member in a valve opening direction;
A plunger coupled to the other side of the valve member of the pressure-sensitive bellows via a coupling guide;
A plunger spring for urging the plunger in the valve opening direction;
An attractor for attracting the plunger against the biasing force of the plunger spring by energizing the electromagnetic coil;
With
A suction force by the suction element is set to be stronger than a combined biasing force of the valve opening spring and the plunger spring, and the coupling guide of the plunger is coupled to the pressure-sensitive bellows when moving in the valve closing direction. And configured to contact only the pressure-sensitive bellows,
When the electromagnetic coil is not energized, the plunger is fixed at a position away from the attractor by the biasing force of the plunger spring, and the pressure-sensitive bellows is fixed to the plunger against the change in pressure in the bellows storage chamber. Extending and contracting with the connection guide side as a fixed point, and controlling the opening of the valve port by the valve member
When energizing the electromagnetic coil, the plunger is attracted toward the attractor, the pressure-sensitive bellows is pressed through the plunger connection guide to fully close the valve port, and the bellows storage chamber The pressure sensitive bellows is expanded and contracted with the valve member side as a fixed point in response to a change in pressure, and the plunger is freely moved in conjunction with the expansion and contraction of the pressure sensitive bellows. Control valve.   The pressure-sensitive control valve according to claim 2 or 3, wherein an effective diameter of the pressure-sensitive bellows and a diameter of the valve port for opening and closing the valve body are set to be equal. The suction element has a guide part at one end, and an end part is screwed to the guide part of the suction element, and a rod part that penetrates the suction element and the plunger and can contact the pressure-sensitive bellows. An adjustment screw having,
The pressure-sensitive control valve according to claim 2, wherein a compression amount of the pressure-sensitive bellows can be adjusted by adjusting a screwing amount of the adjusting screw into the guide portion.

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