JP4018311B2 - Swash plate type variable capacity compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a swash plate type variable capacity compressor that is interposed in a refrigeration cycle of a vehicle air conditioner or the like and is used to compress refrigerant gas.
[0002]
[Prior art]
In some swash plate type variable capacity compressors, for example, as disclosed in Japanese Patent Publication No. 6-87741, the opening degree of a pilot valve is controlled by an excitation current of a solenoid, and the high-pressure side refrigerant in the refrigerant discharge chamber is controlled. Is known to act on the back of a piston valve, and the flow rate of the refrigerant flowing into the refrigerant suction chamber is controlled by the piston valve.
[0003]
[Problems to be solved by the invention]
Since the conventional swash plate type variable capacity compressor is based on a so-called clutch type in which an electromagnetic clutch is incorporated in a compressor driving pulley, the structure becomes complicated and the weight increases. In addition, it is undeniable that the number of parts is increased and disadvantageous in terms of cost.
[0004]
In addition, when the compressor is connected to the clutch and the refrigerant flow rate in the refrigerant suction chamber of the compressor is to be zero in order to avoid freezing of the evaporator, the excitation current of the solenoid that operates the pilot valve is set to 0. It is necessary to make the piston valve full stroke toward the valve closing side at the maximum, resulting in an increase in power consumption.
[0005]
Therefore, the present invention can control the operation of the compressor without a clutch and can be made clutchless and demagnetize the solenoid that operates the pilot valve that controls the flow rate of the refrigerant. A swash plate type variable capacity compressor capable of preventing the evaporator from freezing by setting the refrigerant inflow amount to the refrigerant suction chamber of the compressor to zero is provided.
[0006]
[Means for Solving the Problems]
In the first aspect of the invention, in the swash plate type variable displacement compressor including pressure adjusting means for adjusting the pressure between the refrigerant suction chamber and the crank chamber for controlling the flow rate of the refrigerant flowing into the refrigerant suction chamber,
The pressure adjusting means includes a spool valve, a spring chamber in which a spring for urging the spool valve in the valve closing direction is disposed, and a pressure chamber for accumulating pressure that causes the spool valve to act in the valve opening direction. A flow control valve provided in a low-pressure refrigerant passage upstream of the chamber;
It is provided in a passage that connects the refrigerant discharge chamber and the pressure chamber, and is normally closed by a spring. The valve opening is controlled by the solenoid excitation current, and the high-pressure side refrigerant in the refrigerant discharge chamber is used as the operating pressure. A flow control valve drive mechanism having a pilot valve for introducing and controlling the pressure chamber,
The flow rate control valve is provided with a pressure adjusting passage for releasing the pressure in the pressure chamber to the refrigerant suction chamber side of the low pressure side refrigerant passage, and a passage blocking means for fully closing the pressure adjusting passage when the spool valve is fully closed. It is characterized by providing.
[0007]
The invention according to claim 2 is characterized in that the passage blocking means according to claim 1 is configured to fully close the pressure adjusting passage even when the spool valve is fully opened.
[0008]
According to a third aspect of the present invention, the pressure adjusting passage according to the first and second aspects is provided in a housing in which the spool valve is accommodated so as to communicate with the pressure chamber and the refrigerant suction chamber side of the low-pressure side refrigerant passage. A passage, a recess provided in the outer peripheral surface of the spool valve so as to communicate with the opening on the pressure chamber side of the communication passage, an orifice hole provided in communication with the recess and the pressure chamber in the spool valve, and The recess formation position is set to a position communicating with the opening on the pressure chamber side of the communication passage only within a predetermined opening range of the spool valve, and the passage shut-off means is configured by the spool valve itself. .
[0009]
In the invention of claim 4, the spring chamber of the flow rate control valve according to claim 1 is communicated with the refrigerant suction chamber side of the low-pressure side refrigerant passage through the passage, and the pressure chamber and the spring chamber are connected to the spool valve. A throttle passage that communicates with each other is provided, and these passages and the throttle passage constitute a pressure adjustment passage.
[0010]
The invention according to claim 5 is characterized in that the passage blocking means according to claim 4 is configured to fully close the pressure adjusting passage even when the spool valve is fully opened.
[0011]
According to the invention of claim 6, the passage blocking means according to claim 5 is provided in the throttle passage, and the throttle passage is fully closed by the differential pressure between the pressure chamber and the spring chamber when the spool valve is fully closed. And a fully open restriction stopper that is provided in the spring chamber and abuts against the end face of the spool valve when the spool valve is fully open to restrict the spool valve to fully open and closes the opening end of the throttle passage. It is characterized by.
[0012]
According to a seventh aspect of the present invention, the throttle passage according to any one of the fourth to sixth aspects includes a communication passage provided in the spool valve so as to communicate with the pressure chamber and the spring chamber, and an orifice hole. It is characterized by comprising a bush fitted and fixed to one open end.
[0013]
In the invention of claim 8, the spool valve according to claims 1 to 7 is characterized in that the pressure receiving areas on both side surfaces of the spool groove are made equal.
[0014]
According to the ninth aspect of the present invention, the flow control valve drive mechanism according to any one of the first to eighth aspects detects the pressure on the evaporator side upstream of the flow control valve in the low-pressure side refrigerant passage, and determines a predetermined pilot valve. When the pressure on the evaporator side changes from a certain level in the opening state, the pilot valve is operated in the valve closing direction or the valve opening direction, and the valve opening degree of the flow control valve is adjusted to keep the pressure on the evaporator side constant. It is characterized by having feedback means for holding.
[0015]
In a tenth aspect of the present invention, the flow control valve drive mechanism according to any one of the first to ninth aspects is configured so that the crank chamber communicates with the evaporator side upstream of the flow control valve of the low-pressure side refrigerant passage. It is characterized by having.
[0016]
【The invention's effect】
According to the first aspect of the present invention, when the current supplied to the solenoid of the flow control valve drive mechanism is set to 0 and the solenoid is demagnetized, the pilot valve is closed and the operating pressure is supplied to the pressure chamber of the flow control valve. Therefore, the spool valve is closed to reduce the amount of refrigerant flowing into the refrigerant suction chamber to zero, and stop the decrease in the evaporator side pressure upstream of the flow control valve in the low pressure side refrigerant passage, thereby preventing the evaporator from freezing. be able to.
[0017]
Therefore, at the time of the evaporator freezing prevention operation, it is only necessary to stop the supply of the excitation current to the solenoid, so that the power consumption can be reduced and the load of the compressor is made almost zero by the fully closed operation of the spool valve. The output of the drive source can be improved.
[0018]
In addition, by stopping the supply of the excitation current to the solenoid and closing the spool valve of the flow control valve in this way, the pressure in the refrigerant suction chamber drops and the cylinder internal pressure and the crank chamber that sucked the refrigerant In order to minimize the piston stroke and reduce the compression work of the compressor to almost zero by the moment caused by the force applied to each piston, the compression work of the compressor is almost zero. The operation can be interrupted / interrupted and clutchless can be achieved.
[0019]
Therefore, the structure of the compressor can be simplified, a reduction in size and weight can be realized, and a cost advantage can be obtained.
[0020]
In addition, the flow control valve has a pressure adjustment passage for releasing the pressure in the pressure chamber to the refrigerant suction chamber side of the low-pressure side refrigerant passage, so that the flow control valve can be opened in a state where the spool valve is opened at a required opening degree. When the pilot valve is closed due to the demagnetization of the solenoid of the drive mechanism, the pressure in the pressure chamber of the flow control valve escapes to the refrigerant suction chamber side of the low-pressure side refrigerant passage through the pressure adjustment passage, so the spool valve is closed by the spring biasing force. The operation is not hindered and the responsiveness can be improved.
[0021]
Moreover, since the pressure adjusting passage is fully closed by the passage blocking means in the fully closed position of the spool valve, when the pilot valve is opened, the pressure in the pressure chamber can be quickly raised. Even when the refrigerant discharge pressure introduced as an operating pressure into the pressure chamber is low, such as when the compressor is under low load, the pressure in the pressure chamber can rise quickly and the spool valve can be activated. The valve opening performance can be improved.
[0022]
According to the second aspect of the present invention, in addition to the effect of the first aspect, the passage blocking means blocks the pressure adjusting passage even when the spool valve is fully opened. It is possible to prevent high-temperature and high-pressure refrigerant introduced into the pressure chamber at the time of load from flowing out to the refrigerant suction chamber side via the pressure adjustment passage, and therefore prevent deterioration of the cooling performance when the spool valve is fully opened. I can do this.
[0023]
According to the third aspect of the present invention, in addition to the effects of the first and second aspects of the invention, the spool valve itself can constitute the passage blocking means and no special parts are required. Can be advantageously obtained.
[0024]
According to the fourth aspect of the present invention, in addition to the effect of the first aspect of the invention, the spool valve itself is provided with a throttle passage and the spring chamber is opened to the refrigerant suction chamber side for maintaining the operation balance of the spool valve. Since the pressure adjustment passage is configured with the passage, the passage hole processing of the compressor housing can be reduced as much as possible, the degree of freedom in designing the compressor housing can be expanded and the number of processing steps can be reduced, and the cost can be reduced. Can be advantageously obtained.
[0025]
According to the invention described in claim 5, in addition to the effect of the invention of claim 4, the passage blocking means blocks the pressure adjusting passage even when the spool valve is fully opened. It is possible to prevent the high-temperature and high-pressure refrigerant introduced into the pressure chamber at the time of high load from flowing out to the refrigerant suction chamber side via the pressure adjustment passage, and thus prevent deterioration of the cooling performance when the spool valve is fully opened. it can.
[0026]
According to the sixth aspect of the invention, in addition to the effect of the fifth aspect of the invention, the differential pressure valve and the spool valve provided with the throttle passage having a function of shutting off the pressure adjusting passage when the spool valve is fully closed and fully opened. Therefore, the passage blocking means can be advantageously configured with a simple design and structure.
[0027]
According to the seventh aspect of the invention, in addition to the effects of the fourth to sixth aspects, the spool valve is formed with a communication passage, and a bush having an orifice hole at one opening end thereof is fitted and fixed. As a result, the throttle passage can be configured, so that the spool valve can be easily drilled and produced as compared to the case where the narrow passage is directly formed so that a predetermined orifice function can be obtained in the spool valve. Can be improved.
[0028]
According to the eighth aspect of the invention, in addition to the effects of the first to seventh aspects of the invention, the pressure receiving areas on both sides of the spool groove provided in the spool valve of the flow rate control valve are equalized. By simply managing the spring force of the valve spring and the operating pressure acting on the pressure chamber, the accuracy of the open / close stroke of the spool valve can be increased, and highly accurate flow rate control can be performed.
[0029]
According to the invention of claim 9, in addition to the effects of the inventions of claims 1 to 8, when the pilot valve is set to a predetermined opening by a predetermined exciting current, when the vehicle is suddenly accelerated or decelerated, Since the rotation speed of the compressor driven by the same drive source fluctuates, the evaporator side pressure upstream of the flow control valve in the low pressure side refrigerant passage will change, but the evaporator side pressure is kept constant by the feedback means. Therefore, fluctuations in the control temperature of the evaporator due to sudden acceleration and deceleration of the vehicle can be avoided.
[0030]
Therefore, in the air conditioner, the temperature variation of the indoor blowing air is eliminated, and stable air conditioning can be performed.
[0031]
According to the invention described in claim 10, in addition to the effects of the inventions of claims 1-9, the crank chamber communicates with the evaporator side upstream of the flow rate control valve of the low-pressure side refrigerant passage by the pressure adjusting passage. Since the pressure is maintained, the pressure fluctuation due to the blow-by gas in the crank chamber can be eliminated and the accuracy of the variable capacity control can be improved.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0033]
In FIG. 1, reference numeral 1 denotes a compressor housing, a cylinder block 2 having a plurality of cylinder bores 3, a front housing 4 which is disposed on the front side of the cylinder block 2 and forms a crank chamber 5 between the cylinder block 2, and a cylinder A rear housing 6 is provided on the rear side of the block 2 with a valve plate 9 interposed therebetween and forms a refrigerant suction chamber 7 and a refrigerant discharge chamber 8.
[0034]
In the crank chamber 5, a drive plate 11 fixed to the drive shaft 10, a journal 14 slidably connected by a pin 13 to a sleeve 12 slidably fitted to the drive shaft 10, and an outer periphery of the journal 14 And a swash plate 15 that is screwed and fixed thereto.
[0035]
The journal 14 is connected to the drive plate 11 via its arc-shaped long hole 16 and a pin 17, and swinging is restricted by the long hole 16.
[0036]
The piston 18 fitted to each cylinder bore 3 is connected to the swash plate 15 via a pair of shoes 19 sandwiching the swash plate 15.
[0037]
A pulley 20 is rotatably mounted on an outer end portion of the drive shaft 10 via a bearing 21, a first drive transmission plate 22 screwed and fixed to the inner periphery of the pulley 20, and a terminal of the drive shaft 10. The drive shaft 10 is rotated by the pulley 20 by slidably connecting the second drive transmission plate 23 fixed to the drive plate 23 with a certain drive torque or more.
[0038]
The inclination angle of the swash plate 15 is controlled by the moment around the pin 17 of the swash plate 15 generated by the differential pressure between the refrigerant suction chamber 7 and the crank chamber 5 adjusted by the pressure adjusting means 30 disposed in the rear housing 6. By changing the angle of the swash plate 15, the stroke of the piston 18 is changed to change the refrigerant discharge capacity.
[0039]
As shown in FIG. 2, the pressure adjusting means 30 is provided in the low-pressure side refrigerant passage 25 in the vicinity of the refrigerant inlet 24 upstream of the refrigerant suction chamber 7, and directly controls the amount of refrigerant flowing into the refrigerant suction chamber 7. And a flow rate control valve drive mechanism 32 that drives and controls the flow rate control valve 31.
[0040]
In FIG. 1, in order to facilitate understanding of the structure, the flow control valve 31 is shown in a state where it is disposed at right angles to the flow control valve drive mechanism 32 for convenience. The flow control valve 31 is actually arranged in parallel with the flow control valve drive mechanism 32 to make the compressor more compact.
[0041]
The flow rate control valve 31 includes a spool valve 33 arranged orthogonal to the low-pressure side refrigerant passage 25, a spring chamber 37 provided with a spring 34 for urging the spool valve 33 in the valve closing direction, and the spool valve 33 opened. And a pressure chamber 35 for accumulating pressure acting in the direction.
[0042]
Both side surfaces 36a, 36b of the spool groove 36 of the spool valve 33 have the same pressure receiving area.
[0043]
The spring chamber 37 in which the spring 34 is accommodated communicates with the refrigerant suction chamber 7 side downstream of the flow rate control valve 31 of the low-pressure side refrigerant passage 25 by a passage 38.
[0044]
The flow rate control valve drive mechanism 32 is provided in a passage 40 that connects the refrigerant discharge chamber 8 and the pressure chamber 35, and serves as a pilot valve that controls the introduction of the high-pressure refrigerant in the refrigerant discharge chamber 8 into the pressure chamber 35 as an operating pressure. A ball valve 41 and a solenoid 42 for controlling the valve opening degree of the ball valve 41 according to the exciting current are provided.
[0045]
The ball valve 41 is normally seated on a valve seat by a spring 43 and closed.
[0046]
The solenoid 42 is configured to move the armature 44 upward in FIG. 2 when an excitation current is supplied and to push the plunger 45 to control the valve opening degree of the ball valve 41.
[0047]
The flow rate control valve drive mechanism 32 detects the pressure on the evaporator side upstream of the flow rate control valve 31 in the low pressure side refrigerant passage 25 and makes the pressure on the evaporator side variably controlled by the excitation current of the solenoid 42 constant. Feedback means 46 for holding is provided.
[0048]
The feedback means 46 is held by the diaphragm 47, a diaphragm 47 that separates the atmospheric pressure chamber 48 and the refrigerant pressure chamber 49, a feedback passage 50 that introduces the evaporator-side pressure into the refrigerant pressure chamber 49, and the solenoid 42. Of the low pressure side refrigerant passage 25 when the ball valve 41 is controlled to a predetermined opening degree. When the pressure on the evaporator side changes from a certain pressure, the change in pressure is detected by the diaphragm 47, and the ball valve 41 is operated in the valve closing direction or the valve opening direction by the plunger 51. Is adjusted so that the pressure on the evaporator side is kept constant.
[0049]
The refrigerant pressure chamber 49 is communicated with the crank chamber 5 through a pressure adjusting passage 52, and the crank chamber 5 is communicated with the evaporator side upstream of the flow rate control valve 31 in the low-pressure side refrigerant passage 25.
[0050]
On the other hand, the flow control valve 31 is provided with a pressure adjustment passage 53 for releasing the pressure in the pressure chamber 35 to the refrigerant suction chamber 7 side of the low-pressure side refrigerant passage 25, and the pressure adjustment passage 53 when the spool valve 33 is fully closed. There is provided a passage blocking means 60 for fully closing.
[0051]
In this embodiment, as shown in FIGS. 3 and 4, the pressure adjusting passage 53 is fully closed even when the spool valve 33 is fully opened.
[0052]
Specifically, in FIGS. 2 to 4, the rear housing 6 in which the spool valve 33 is accommodated is provided with a communication passage 61 that communicates with the pressure chamber 35 and the refrigerant suction chamber side of the low-pressure side refrigerant passage 25. On the other hand, a concave portion 62 is provided on the outer peripheral surface of the spool valve 33 so as to be able to communicate with the opening on the pressure chamber 35 side of the communication passage 61, and an orifice hole 63 having a predetermined throttle area for communicating the concave portion 62 and the pressure chamber 35 is provided. The communication passage 61, the recess 62, and the orifice hole 63 constitute the pressure adjusting passage 53 described above.
[0053]
The recess 62 on the outer peripheral surface of the spool valve 33 communicates with the opening of the communication passage 61 only in a predetermined opening range of the spool valve 33, that is, only in an opening range excluding the fully closed position and the fully open position. The formation position is set so that the spool valve 33 itself constitutes the passage blocking means 60 described above.
[0054]
The spring chamber 37 is provided with a full opening restriction stopper 66 that abuts against the end face of the spool valve 33 and restricts the full opening when the spool valve 33 is fully opened.
[0055]
According to the structure of the above embodiment, when the solenoid 42 is excited, the valve opening degree of the ball valve 41 is controlled according to the exciting current, and the high-pressure side refrigerant in the refrigerant discharge chamber 8 passes through the ball valve 41 and passes through the passage 40. Is introduced into the pressure chamber 35 of the flow control valve 31 as an operating pressure.
[0056]
In response to the pressure in the pressure chamber 35, the spool valve 33 moves in a direction to open against the spring force of the spring 34, and expands the flow path of the low-pressure side refrigerant passage 25 to supply refrigerant to the refrigerant suction chamber 7. By controlling the inflow amount, adjusting the differential pressure between the refrigerant suction chamber 7 and the crank chamber 5 to control the inclination angle of the swash plate 15, and changing the stroke of the piston 18 to control the refrigerant discharge amount. The temperature of the outside evaporator is controlled.
[0057]
Here, since the flow rate control valve 31 includes a pressure adjusting passage 53 for releasing the pressure in the pressure chamber 35 to the refrigerant suction chamber side of the low-pressure side refrigerant passage 25, the spool valve 33 is opened at a required opening degree. When the pilot valve 41 is closed due to the demagnetization of the solenoid 42 in this state, the operating pressure in the pressure chamber 35 is quickly released from the pressure adjusting passage 53 to the refrigerant suction chamber side, and the spool valve is driven by the biasing force of the spring 34. The valve closing operation of 33 is not hindered, and the responsiveness can be improved.
[0058]
Moreover, since the pressure adjusting passage 53 is substantially fully closed by the passage blocking means 60 when the spool valve 33 shown in FIG. 3 is in the fully closed position, when the pilot valve 41 is opened, The rise of pressure can be performed quickly. Therefore, even when the refrigerant discharge pressure introduced as the operating pressure into the pressure chamber 35 is low as in the case of a low load of the compressor, the pressure in the pressure chamber 35 is reduced. The start-up can be performed quickly, and the startability of the spool valve 33, that is, the valve opening performance can be improved.
[0059]
Further, the passage blocking means 60 is introduced into the pressure chamber 35 at the time of high load of the compressor in which the spool valve 33 is fully opened in order to fully close the pressure adjustment passage 53 even when the spool valve 33 shown in FIG. 4 is fully opened. The high-temperature and high-pressure refrigerant thus produced can be prevented from flowing out to the refrigerant suction chamber 7 side via the pressure adjustment passage 53, and therefore, the deterioration of the cooling performance when the spool valve 33 is fully opened can be prevented. it can.
[0060]
Particularly in this embodiment, the passage blocking means 60 is configured by the spool valve 33 itself by setting the opening formation position of the communication passage 61 on the pressure chamber 35 side and the formation position of the recess 62 on the outer peripheral surface of the spool valve 33. Therefore, it is possible to obtain a cost advantage without requiring a dedicated part.
[0061]
On the other hand, for the purpose of preventing the evaporator from freezing during the operation of the refrigeration cycle, the refrigerant inflow amount into the refrigerant suction chamber 7 is set to 0 and the pressure drop on the evaporator side upstream of the flow rate control valve 31 in the low-pressure side refrigerant passage 25 is stopped. For this, the solenoid 42 is demagnetized by setting the supply current to the solenoid 42 to 0. The demagnetization of the solenoid 42 closes the ball valve 41 and supplies the operating pressure to the pressure chamber 35 of the flow control valve 31. Therefore, the spool valve 33 is closed by the spring force of the spring 34 to shut off the low-pressure side refrigerant passage 25, and the amount of refrigerant flowing into the refrigerant suction chamber 7 is set to 0 to control the inclination angle of the swash plate 15. Thus, the piston stroke is reduced and the evaporator side pressure in the low-pressure side refrigerant passage 25 is prevented from being lowered to prevent the evaporator from freezing.
[0062]
In this way, during the freeze prevention operation of the evaporator, it is only necessary to stop the supply of the excitation current to the solenoid 42, so that power consumption can be reduced and the load on the compressor can be substantially reduced by the fully closed operation of the spool valve 33. Therefore, the output of the drive source can be improved.
[0063]
As described above, when the supply of the excitation current to the solenoid 42 is stopped and the spool valve 33 of the flow control valve 31 is operated to close, the pressure in the refrigerant suction chamber 7 drops, and the cylinder internal pressure and the crank chamber 5 In order to make the compression work of the compressor almost zero by setting the inclination of the swash plate 15 by the moment around the pin 17 and minimizing the stroke of the piston 18, the compression by the excitation and demagnetization of the solenoid 42 is performed. The operation of the machine can be interrupted / interrupted, and the clutch that has been interrupted to transmit the driving force to the compressor in the past can be abolished so as to be so-called clutchless. Certain magnets, coils, etc. can be dispensed with.
[0064]
Therefore, the structure of the compressor can be simplified, the size and weight can be reduced, and the wiring for energizing the clutch can be eliminated, and the cost can be advantageously obtained.
[0065]
In addition, when a predetermined exciting current is supplied to the solenoid 42 of the flow control valve drive mechanism 32 and the ball valve 41 is at a predetermined opening degree, when the vehicle is suddenly accelerated or decelerated, the low-pressure side refrigerant passage is caused by the rotational fluctuation of the compressor. The pressure on the evaporator side upstream of the 25 flow control valve 31 changes, but this change in pressure is immediately detected by the diaphragm 47 of the feedback means 46 and the ball valve 41 is moved in the valve closing direction or valve opening direction via the plunger 51. By being actuated, the evaporator side pressure can be maintained at a constant pressure corresponding to the excitation current of the solenoid 42, so that fluctuations in the evaporator control temperature due to sudden acceleration and deceleration of the vehicle can be avoided.
[0066]
Here, since both side surfaces 36a and 36b of the spool groove 36 provided in the spool valve 33 of the flow rate control valve 31 have the same pressure receiving area, the spring of the spring 34 that urges the spool valve 33 in the valve closing direction. Only by managing the force and the operating pressure acting on the pressure chamber 35, the accuracy of the opening / closing stroke of the spool valve 33 can be obtained, and a highly accurate flow rate control can be performed.
[0067]
Further, the crank chamber 5 communicates with the evaporator side upstream of the flow rate control valve 31 of the low pressure side refrigerant passage 25 by the pressure adjusting passage 52 and is kept constant at the same pressure. Thus, the accuracy of variable capacity control can be improved.
[0068]
5 and 6 show a second embodiment of the present invention. In this embodiment, the required throttle cross-sectional area for communicating the pressure chamber 35 and the spring chamber 37 with the spool valve 33 of the flow control valve 31 is shown. The throttle passage 64 is provided, and the pressure regulation passage 53 is configured by the throttle passage 64 and the passage 38 that opens the spring chamber 37 to the refrigerant suction chamber side.
[0069]
The throttle passage 64 is provided on the central axis of the spool valve 33, and when the spool valve 33 is fully opened, the opening end of the throttle passage 64 on the spring chamber side is the end face of the full opening restriction stopper 66 provided in the spring chamber 37 described above. In addition, the throttle passage 64 is provided with a differential pressure valve 65 that closes the throttle passage 64 by the differential pressure between the pressure chamber 35 and the spring chamber 37 when the spool valve 33 is fully closed. A passage blocking means 60 is constituted by the pressure valve 65 and the fully open restriction stopper 66.
[0070]
In the present embodiment, a large-diameter portion is formed in the opening portion of the throttle passage 64 on the spring chamber 37 side, and the differential pressure valve 65 is disposed here.
[0071]
The differential pressure valve 65 is fitted to a ball valve 67 seated on a tapered valve seat 68 provided in the throttle passage 64, a spring 69 biasing the ball valve 67 in the seating direction of the valve seat 68, and the large diameter portion. A spring seat 71 is formed which is fixed to form a valve chamber 70 and holds a spring 69. The spring seat 71 is provided with a plurality of apertures 72 for opening the valve chamber 70 to the spring chamber 37, and a spool valve. When the opening 33 is fully opened, the opening 72 is closed by the fully opening restriction stopper 66.
[0072]
The spring 69 of the differential pressure valve 65 causes the ball valve 67 to speed up when the operating pressure is introduced into the pressure chamber 35 by opening the pilot valve 41 and the differential pressure between the pressure chamber 35 and the spring chamber 37 exceeds a predetermined value. The spring force is arbitrarily set to open the valve.
[0073]
Therefore, according to the second embodiment, the same effects as those of the first embodiment can be obtained. In particular, the spool valve 33 itself is provided with the throttle passage 64 and the spring chamber 37 is opened to the refrigerant suction chamber side. Since the pressure adjusting passage 53 is constituted by the passage 38 for maintaining the operation balance of the valve 33, the machining of the passage hole of the rear housing 6 can be reduced as much as possible, and the degree of freedom in designing the rear housing 6 can be expanded. At the same time, the number of processing steps can be reduced, and the cost can be advantageously obtained.
[0074]
Further, the function of shutting off the pressure adjustment passage 53 when the spool valve 33 is fully closed and fully opened is performed by the differential pressure valve 65 provided in the throttle passage 64 and the fully open restriction stopper 66 of the spool valve 33. The passage blocking means 60 can be advantageously configured with a simple design and structure.
[0075]
FIG. 7 shows a third embodiment of the present invention. In the second embodiment, a throttle passage 64 is formed in the spool valve 33 with a predetermined throttle cross-sectional area. In this third embodiment, FIG. A communication passage 73 that connects the pressure chamber 35 and the spring chamber 37 is formed on the central axis of the spool valve 33, and a large diameter portion is formed in the opening portion on the pressure chamber 35 side, and a predetermined throttle is formed in the large diameter portion. By fitting and fixing a bush 74 having an orifice hole 75 having an area, the communication passage 73 and the bush 74 constitute a throttle passage 64.
[0076]
Therefore, according to the third embodiment, compared with the case where the narrow-diameter throttle passage 64 is directly formed so as to obtain a predetermined orifice function in the spool valve 33 as in the second embodiment, the communication passage 73 is not formed. Since the hole diameter can be formed large, the spool valve 33 can be easily drilled and the productivity can be increased.
[0077]
In both the second and third embodiments, the differential pressure valve 65 is provided at the opening end of the throttle passage 64 on the spring chamber side, but this can also be provided at the opening end of the pressure chamber side. The bush 74 in the embodiment is provided at the opening end on the spring chamber side.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
FIG. 2 is an explanatory cross-sectional view systematically showing pressure adjusting means in one embodiment of the present invention.
3 is an explanatory cross-sectional view showing a state in which the spool valve of the flow rate control valve of the pressure adjusting means shown in FIG. 2 is fully closed.
4 is a cross-sectional explanatory view showing a state in which the spool valve of the flow rate control valve of the pressure adjusting means shown in FIG. 2 is fully opened.
FIG. 5 is an explanatory cross-sectional view of the second embodiment of the flow control valve when the spool valve is fully closed.
FIG. 6 is an explanatory cross-sectional view of the second embodiment of the flow control valve when the spool valve is fully opened.
FIG. 7 is a cross-sectional view showing a structure of a spool valve in a third embodiment of the flow control valve.
[Explanation of symbols]
5 Crank chamber
6 Rear housing
7 Refrigerant suction chamber
8 Refrigerant discharge chamber
25 Low pressure side refrigerant passage
30 Pressure adjusting means
31 Flow control valve
32 Flow control valve drive mechanism
33 Spool valve
34, 43 Spring
35 Pressure chamber
36 Spool groove
37 Spring room
38 Communication path between spring chamber and refrigerant suction chamber
40 Communication path between pressure chamber and refrigerant discharge chamber
41 Pilot valve
42 Solenoid
46 Feedback means
52 Pressure control passage of flow control valve drive mechanism
53 Pressure control passage of flow control valve
60 Passage blocking means
61 communication path
62 recess
63,75 Orifice hole
64 Restricted passage
65 Differential pressure valve
66 Fully open restriction stopper
73 Communication path provided in spool valve
74 Bush

Claims (10)

In the swash plate type variable displacement compressor provided with pressure adjusting means (30) for adjusting the pressure between the refrigerant suction chamber (7) and the crank chamber (5) for controlling the flow rate of the refrigerant flowing into the refrigerant suction chamber (7),
The pressure adjusting means (30) includes a spool valve (33), a spring chamber (37) provided with a spring (34) for urging the spool valve (33) in the valve closing direction, and a spool valve (33). A flow rate control valve (31) provided with a pressure chamber (35) for accumulating pressure acting in the valve opening direction and provided in the low-pressure side refrigerant passage (25) upstream of the refrigerant suction chamber (7);
It is provided in a passage (40) communicating with the refrigerant discharge chamber (8) and the pressure chamber (35), and is normally closed by a spring (43), and is opened by an excitation current of a solenoid (42). And a flow rate control valve drive mechanism (32) having a pilot valve (41) that controls the introduction of the high-pressure side refrigerant in the refrigerant discharge chamber (8) into the pressure chamber (35) as an operating pressure,
The flow control valve (31) is provided with a pressure adjusting passage (53) for releasing the pressure in the pressure chamber (35) to the refrigerant suction chamber (7) side of the low-pressure side refrigerant passage (25), and a spool valve ( 33) A swash plate type variable displacement compressor provided with a passage blocking means (60) for fully closing the pressure adjusting passage (53) when fully closed. The swash plate type variable displacement compressor according to claim 1, wherein the passage blocking means (60) is configured to fully close the pressure adjusting passage (53) even when the spool valve (33) is fully opened. A pressure adjusting passage (53) is provided in the housing (6) containing the spool valve (33) so as to communicate with the pressure chamber (35) and the refrigerant suction chamber (7) side of the low pressure side refrigerant passage (25). A passage (61); a recess (62) provided on the outer peripheral surface of the spool valve (33) so as to communicate with an opening on the pressure chamber (35) side of the communication passage (61); and the recess on the spool valve (33). (62) and an orifice hole (63) provided in communication with the pressure chamber (35), and the formation position of the recess (62) is only within a predetermined opening range of the spool valve (33). The passage blocking means (60) is constituted by the spool valve (33) itself at a position communicating with the opening on the pressure chamber (35) side of the communication passage (61). The swash plate type variable capacity compressor described in 1. The spring chamber (37) of the flow rate control valve (31) communicates with the refrigerant suction chamber (7) side of the low-pressure side refrigerant passage (25) through the passage (38), and the pressure chamber (35) is connected to the spool valve (33). And a throttle passage (64) communicating with the spring chamber (37), and the pressure adjustment passage (53) is constituted by the passage (38) and the throttle passage (64). The swash plate type variable capacity compressor described in 1. The swash plate type variable capacity compressor according to claim 4, wherein the passage blocking means (60) is configured to fully close the pressure adjusting passage (53) even when the spool valve (33) is fully opened. A passage blocking means (60) is provided in the throttle passage (64), and when the spool valve (33) is fully closed, the throttle passage (64) is opened by the differential pressure between the pressure chamber (35) and the spring chamber (37). A differential pressure valve (65) that is fully closed, and a spring chamber (37) that contacts the end face of the spool valve (33) when the spool valve (33) is fully opened to fully open the spool valve (33). 6. The swash plate type variable displacement compressor according to claim 5, wherein the swash plate type variable displacement compressor is constituted by a full opening restriction stopper (66) for closing an opening end of the throttle passage (64). The throttle passage (64) includes a communication passage (73) provided in communication with the spool valve (33) in communication with the pressure chamber (35) and the spring chamber (37), and an orifice hole (75). 73) A swash plate type variable capacity compressor according to any one of claims 4 to 6, characterized in that it is constituted by a bush (74) fitted and fixed to one open end of 73). The swash plate type variable displacement compressor according to any one of claims 1 to 7, wherein the spool valve (33) has equal pressure receiving areas on both side surfaces of the spool groove (36). The flow rate control valve drive mechanism (32) detects the pressure on the evaporator side upstream of the flow rate control valve (31) of the low pressure side refrigerant passage (25), and when the pilot valve (41) is in a predetermined opening state, the evaporator The pilot valve (41) is operated in the valve closing direction or the valve opening direction when the pressure on the side changes from a constant pressure, and the valve opening degree of the flow control valve (31) is adjusted to keep the pressure on the evaporator side constant. The swash plate type variable capacity compressor according to any one of claims 1 to 8, further comprising feedback means (46) for holding. The flow control valve drive mechanism (32) includes a pressure adjustment passage (52) that communicates the crank chamber (5) with the evaporator side upstream of the flow control valve (31) of the low-pressure side refrigerant passage (25). The swash plate type variable capacity compressor according to any one of claims 1 to 9.

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