JPH11304027A - Sealing structure of pressure control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize hysteresis at the time when a pressure control valve works without causing a trouble in manufacture and to sufficiently secure a sealing property between a second through hole and a large diametrical part of a push rod for a long period of time. SOLUTION: A plate material made of an elastic material is formed in a circular ring shape, and a sealing member 81 an inside diameter of which in a free state is made smaller than an outside diameter of a large diametrical part 73 is provided. A recessed part 80 is formed along an overall periphery on an opening peripheral edge part of a second through hole 64. An outer peripheral edge part of the sealing member 81 is closely fixed in an overall periphery on an end surface of an intermediate member 59 which is a peripheral part of the recessed part 80, and a part to an inside diameter of the sealing member 81 is closely pressed down along an overall periphery on an outer peripheral surface of the large diametrical part 73.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The seal structure of a pressure control valve according to the present invention is incorporated in a variable displacement compressor constituting an air conditioner for a vehicle for cooling and dehumidifying a vehicle interior, for example. The present invention relates to a seal structure incorporated in a pressure control valve for changing the capacity of a compressor.

[0002]

2. Description of the Related Art A vapor compression refrigerator incorporated in an air conditioner for a vehicle is configured as schematically shown in FIG. The compressor 1 compresses the refrigerant vapor sucked from the suction port and then discharges the compressed refrigerant vapor from the discharge port. The refrigerant discharged from the compressor 1 exchanges heat with air while passing through the condenser 2 to radiate heat and condense. The liquid refrigerant discharged from the condenser 2 passes through the liquid tank 3, is decompressed by the expansion valve 4, is sent into the evaporator 5, and evaporates in the evaporator 5. Since the temperature of the evaporator 5 is reduced by the evaporation of the refrigerant inside, the air passing through the evaporator 5 is cooled, and the cooling and dehumidification of the interior of the automobile can be performed. The refrigerant evaporated in the evaporator 5 is sucked into the compressor 1 again from the suction port.

[0003] A compressor 1 constituting a vapor compression type refrigerator incorporated in such an air conditioner for a vehicle is driven by a traveling engine of the vehicle through a belt and a pulley. Therefore, when the vehicle air conditioner is used, the power of the traveling engine is consumed for driving the compressor 1, and in some cases, the power performance becomes insufficient or the power performance becomes unstable. In other words, when the electromagnetic clutch that is attached to the pulley and is turned on and off according to the cooling load causes a large change in the power of the traveling engine that is actually provided for traveling, the above-described situation occurs. Causes inconvenience. In order to eliminate or reduce such inconveniences, so-called variable displacement type compressors that change the discharge amount of the refrigerant as the compressor 1 have been frequently used in recent years.

[0004] Variable displacement compressors have been described in publications such as Japanese Patent Application Laid-Open No. 8-313528. In such a variable displacement compressor, various pressure control valves are used to change the capacity of the variable displacement compressor. FIGS. 5 and 6 show an example of a pressure control valve used in the variable displacement compressor described in Japanese Patent Application Laid-Open No. 8-313528.

[0005] Casing 6 constituting compressor 1
Is to connect the center casing body 7 to the head case 8 and the end plate 9
, And are sandwiched from both sides in the axial direction (left-right direction in FIG. 5), and further connected by a plurality of connecting bolts (not shown). Inside the head case 8, a suction chamber 10 and a discharge chamber 11 are provided. The pressure in the suction chamber 10 as well as in the discharge chamber 11 is a positive pressure. Further, a flat partition plate 15 is sandwiched between the casing body 7 and the head case 8. The suction chamber 10 communicates with a suction port 12 a provided on the outer surface of the head case 8. or,
The discharge chamber 11 also communicates with a discharge port 12b provided in the head case 8. Then, the suction port 12a is connected to the outlet of the evaporator 5 (FIG. 4).
The discharge port 12b is connected to the inlet of the condenser 2 (FIG. 4).

In the casing 6, a drive shaft 13 is supported by a pair of radial needle bearings 22a and 22b so as to freely rotate only in a state of being bridged between the casing body 7 and the end plate 9, and a pair of radial needle bearings is provided. Thrust roller bearing 23
The thrust load applied to the drive shaft 13 can be freely supported by a and 23b. A plurality of cylinders 14 (for example, five to six at equal intervals in the circumferential direction, only one is shown in the drawing) are formed inside the casing 6 around the drive shaft 13. The pistons 16 are respectively fitted to the inside of the plurality of cylinders 14 formed in the casing body 7 so as to be displaceable in the axial direction.

Further, inside a part of the casing body 7,
A swash plate chamber 17 is provided between the end plate 9 and the portion where the plurality of cylinders 14 are formed. And the drive shaft 1
A sleeve 18 slidable with respect to the drive shaft 13 and a support bracket 19 externally fitted to and fixed to the drive shaft 13 are provided in a portion located in the swash plate chamber 17 at the intermediate portion of 3.
The cylinders 14 are provided sequentially from the side where the cylinders 14 are provided. or,
A support cylinder 20 is pivotally supported on the sleeve 18 so as to be swingable with respect to the sleeve 18, and a swash plate 21 is externally fitted and fixed to the support cylinder 20. Then, a portion of the swash plate 21 near the inner diameter and a portion of the support bracket 19 near the outer diameter are connected by a link arm 24. The link arm 24 is supported by a pair of pivot shafts 25, 25 so as to freely swing with respect to the support bracket 19 and the swash plate 21, respectively. Incidentally, one end surface of the sleeve 18 (FIG. 5)
A compression spring 26 is provided between the left end surface of the support bracket 19 and one side surface of the base end of the support bracket 19 (the right end surface in FIG. 5) to apply elastic force to the sleeve 18 in a direction approaching the cylinder 14. I have.

A plurality of swash plates 21 supported around the drive shaft 13 in the circumferential direction and the pistons 16
Is a pair of sliding shoes 27,
27. The inner surfaces (surfaces facing each other) of each of the sliding shoes 27, 27 are flat surfaces and are in sliding contact with the outer diameter portions of both sides of the swash plate 21. The outer surfaces of the sliding shoes 27, 27 (the side opposite to the mating sliding shoe 27) are spherical convex surfaces, and the inner surfaces are brought into contact with both side surfaces of the swash plate 21. , 2
7 is located on a single spherical surface. Then, 1 is provided at the rear end (the left end in FIG. 5) of each of the pistons 16.
The outer surfaces of the sliding shoes 27, 27 are closely contacted with the pair of spherical concave surfaces 28, 28. Therefore,
Guide part 2 provided on a part of the inner peripheral surface of casing body 7
9, each piston 1 whose rotation around the axial direction is prevented.
6 pushes and pulls each of the pistons 16 with the swing displacement of the swash plate 21 accompanying the rotation of the drive shaft 13, and reciprocates these pistons 16 in the cylinder 14 in the axial direction.

On the other hand, the partition plate 15 sandwiched between the butting portions of the casing body 7 and the head case 8 has:
A suction port 30 for communicating the suction chamber 10 with the cylinder 14 and a discharge port 31 for communicating the discharge chamber 11 with the cylinder 14 are provided. Each of the cylinders 1 is connected to the suction port 30 from the suction chamber 10.
A suction valve 32 for flowing the refrigerant vapor only toward the discharge port 4 is provided, and a discharge valve 33 for flowing the refrigerant vapor only from each cylinder 14 toward the discharge chamber 11 is provided at the discharge port 30.
Is provided.

[0010] The compressor 1 configured as described above includes:
In order to change the capacity of the compressor 1 in accordance with the cooling load, a pressure control valve 34 for controlling the communication between the discharge chamber 11 and the inclined slope chamber 17 according to the pressure in the suction chamber 10.
Is provided in the head case 8. As shown in detail in FIG. 6, the pressure control valve 34 includes a diaphragm type actuator 35 and an opening / closing valve 36 which is opened and closed by the actuator 35. The inside of the case 37 constituting the actuator 35 is a diaphragm 3
8 divides the chamber into an atmospheric pressure chamber 39 and a pressure introduction chamber 40. The pressure introduction chamber 40 is communicated with a part 10 a of the suction chamber 10 so that the pressure in the pressure introduction chamber 40 is equal to the pressure in the suction chamber 10. A push plate 41 as a displacement member is provided at the center of the diaphragm 38, and the push plate 41 is provided by a compression spring 42 provided in the atmospheric pressure chamber 39.
Are elastically pressed toward the pressure introduction chamber 40.
Therefore, when the pressure in the suction chamber 10 is high, the push plate 41 is displaced toward the atmospheric pressure chamber 39 against the elasticity of the compression spring 42, and conversely,
When the internal pressure is low, it is displaced toward the pressure introduction chamber 40 based on the elasticity of the compression spring 42. Also, the push rod 4 is provided at the center of the push plate 41.
7 (the lower end in FIGS. 5 and 6). The push rod 47 is inserted into a through hole 48 that penetrates the axially opposite side surfaces of the intermediate member 49 so as to be freely displaceable in the axial direction. A valve seat 43 described below is provided at one end side (upper end side in FIGS. 5 and 6) of the through hole 48 at the periphery of the opening. An intermediate portion of the through hole 48 communicates with a communication passage 46 communicating with the swash plate chamber 17. A communication passage 58 having a diameter adjusted by an orifice is provided between the swash plate chamber 17 and a part 10a of the suction chamber 10, and the communication passage 58 reduces the pressure in the swash plate chamber 17 by the suction. It escapes into the room 10.

On the other hand, the on-off valve 36 is provided with the through hole 48.
A valve seat 43 provided on the peripheral edge of one end side of the
Ball 44, which is a valve body opposed to
And a compression spring 45, which is an elastic member that elastically presses the spring toward the valve seat 43. The elasticity of the compression spring 45 is much lower than the elasticity of the compression spring 42 provided in the atmospheric pressure chamber 39. When the ball 44 is separated from the valve seat 43, the on-off valve 36 allows the discharge chamber 11 communicating with the inlet of the condenser 2 (FIG. 4) to communicate with the communication passage 46. In this state, the communication between the discharge chamber 11 and the communication passage 46 is cut off.
Further, an outer peripheral surface of an intermediate portion of a push rod 47 constituting the actuator 35 and an inner peripheral surface of a part of the through hole 48 closer to the push plate 41 than a part communicated with the communication passage 46. Is sealed by a seal structure (not shown).

In order to open and close the on-off valve 36 as described above by the actuator 35 as described above, the push rod 4
The tip surface (the upper end surface in FIGS. 5 and 6) of 7 is opposed to the ball 44. When the pressure in the pressure introducing chamber 40 communicating with the suction chamber 10 is high and the push plate 41 is completely displaced toward the atmospheric pressure chamber 39, the push rod 47 does not push the ball 44, 44
Is based on the discharge refrigerant pressure and the elasticity of the compression spring 45,
The state comes into contact with the valve seat 43. On the other hand, when the pressure in the suction chamber 10 is low, the push rod 47 pushes the ball 44 by the displacement of the push plate 41 based on the elasticity of the compression spring 42, and the ball 44 is moved to the valve seat 43. Keep away from

The pressure control valve constructed as described above and the variable displacement compressor using this pressure control valve operate as follows. That is, in order to cool or dehumidify the interior of the automobile, when driving a vapor compression refrigerator, the driving force of the engine is transmitted via an electromagnetic clutch or the like (not shown).
The drive shaft 13 is driven to rotate. As a result, the swash plate 2
1 rotates to reciprocate the plurality of pistons 16 in the cylinder 14 respectively. As the piston 16 reciprocates, refrigerant vapor in the suction chamber 10 communicating with the suction port 12a is sucked into the cylinder 14 through the suction port 30. The refrigerant vapor is then compressed in the cylinder 14 and then sent out to the discharge chamber 11 through the discharge port 31.

The pressure in the swash plate chamber 17 is applied to the rear surfaces of the plurality of pistons 16 (left surface in FIG. 5).
On the other hand, the compression space of the cylinder 14 (the piston 16
In the space between the front surface and the partition plate 15). Therefore, each of these pistons 16 is connected to the swash plate chamber 17.
The pressure according to the difference between the internal pressure and the pressure in the compression space tends to be pushed to the lower pressure side. And each piston 1
The sum of these forces acting on the swash plate 21 is applied in a direction that changes the inclination angle of the swash plate 21. Of course, the pressure in the compression space changes according to the stroke of the piston 16, but since the piston 16 reciprocates at a high speed, the pressure in the compression space can be considered as an average value of all strokes.

When the cooling load of the evaporator 5 (FIG. 4) is large and a large amount of refrigerant vapor needs to be compressed by the compressor 1, the pressure of the refrigerant evaporated by the evaporator 5 and sent to the suction chamber 10 becomes high. Therefore, the pressure in the pressure introduction chamber 40 communicating with the suction chamber 10 also increases. In this state, the tip of the push rod 47 does not push the ball 44. As a result, the refrigerant vapor in the high-pressure chamber 11 is not sent to the swash plate chamber 17 and
Since the refrigerant vapor in the swash plate chamber 17 escapes into the suction chamber 10 through the communication passage 58, the pressure in the swash plate chamber 17 decreases. In this state, the pressure in the swash plate chamber 17 becomes sufficiently lower than the pressure in the compression space, and the force of pressing each piston 16 toward the swash plate 21 and pressing leftward in FIG. . On the other hand, as described above, the link arm 24 for connecting the swash plate 21 and the support bracket 19 is provided at a position displaced radially outward from the center of the drive shaft 13. For this reason, the moment when each piston 16 presses the swash plate 27 differs for each piston 16, and is small for the piston 16 near the link arm 24,
It is larger for the piston 16 which is also farther away. Therefore, when the pressure in the swash plate chamber 17 is low, the side of the swash plate 21 far away from the link arm 24 is largely inclined away from the cylinder 14 as shown in FIG. The inclination angle θ of the swash plate 21 increases). As a result, the stroke of each piston 16 accompanying the rotation of the swash plate 27 increases, and the capacity of the compressor 1 increases.

Conversely, when the cooling load of the evaporator 5 is small and it is not necessary to compress a large amount of refrigerant vapor by the compressor 1, the pressure of the refrigerant evaporated by the evaporator 5 and sent to the suction chamber 10 becomes higher. Because it will be lower
The pressure in the pressure introduction chamber 40 communicating with the suction chamber 10 also decreases. In this state, the tip of the push rod 47 pushes the ball 44. As a result, the amount of refrigerant vapor into which the refrigerant vapor in the discharge chamber 11 is sent to the swash plate chamber 17 becomes larger than the amount of refrigerant vapor escaping from the inside of the swash plate chamber 17 into the suction chamber 10 through the communication path 58, The swash plate chamber 17
Internal pressure increases. Then, the inclination angle θ of the swash plate 21 becomes smaller, the stroke of the piston 16 becomes shorter, and the capacity of the compressor 1 decreases.

The pressure control valve used in the variable displacement compressor constructed and operated as described above not only controls the pressure in the inclined slope chamber in accordance with the pressure in the low-pressure chamber as described above, but also controls the electric pressure. An electromagnetic pressure control valve that changes the capacity of a compressor by controlling the pressure in the swash plate chamber is also conventionally known. In the case of such an electromagnetic pressure control valve, the actuator is configured by abutting a base end of a push rod against an iron core and disposing a coil around the iron core. The on-off valve is opened and closed by displacing the push rod in the axial direction based on the energization or stop of the coil. According to such an electromagnetic pressure control valve, the capacity of the compressor can be reduced irrespective of the cooling load, such as when the vehicle is rapidly accelerating or climbing a hill, and the load on the engine that drives the compressor can be reduced.

As such an electromagnetic pressure control valve, there is also known an electromagnetic pressure control valve structure in which the electromagnetic force required to displace the push rod is reduced to improve the efficiency. . In the case of such an electromagnetic pressure control valve with improved efficiency, the space where the valve element constituting the on-off valve exists and the space where the iron core exists are communicated with each other. Then, the pressure in the space where the valve element exists is introduced to the end face of the iron core. Accordingly, the pressure in the space where the valve element exists is not applied to the resistance against the push rod pressing the valve element, and the electromagnetic force required to displace the push rod is reduced by that much, The efficiency of the electromagnetic pressure control valve can be improved. In the case of such a structure of the electromagnetic pressure control valve with improved efficiency, it is necessary to seal between the outer peripheral surface of the intermediate portion of the push rod and a part of the inner peripheral surface of the through hole through which the push rod is inserted. There is.

[0019]

Among the conventional pressure control valves described above, in the case of a structure having improved efficiency, the outer peripheral surface of the intermediate portion of the push rod for opening and closing the on-off valve is inserted through the push rod. Between the inner peripheral surface of some of the through holes,
It is necessary to provide a seal structure. Conventionally, as such a seal structure, an O-ring is provided between an outer peripheral surface of an intermediate portion of the push rod and a part of an inner peripheral surface of the through hole, or a gap existing between these two peripheral surfaces. By minimizing the size of the seal, the space between these two peripheral surfaces was sealed. However, in the seal structure using the O-ring, a part of the O-ring slides with respect to a part of the push rod or the through-hole. Therefore, when the push rod is displaced in the axial direction, sliding resistance is generated, and hysteresis at the time of operating the pressure control valve is increased. In addition, due to the long-term use of the pressure control valve, a part of the O-ring may be worn, and it may not be possible to sufficiently secure the sealing property between the two peripheral surfaces for a long time. . on the other hand,
In the seal structure by minimizing the size of the gap between these two peripheral surfaces, in order to minimize the size of this gap,
It is necessary to control the size of the gap, which is troublesome in manufacturing. Further, the clearance increases with the sliding of the push rod, and there is a possibility that the sealing performance between the two peripheral surfaces cannot be sufficiently secured for a long period of time. The seal structure of the pressure control valve according to the present invention is designed to eliminate any of the above-mentioned disadvantages.

[0020]

According to the present invention, there is provided a pressure control valve sealing structure including a valve member chamber provided on each of both sides in the axial direction of an intermediate member provided through a middle member provided in a casing. A push rod that is inserted into a through-hole that communicates both ends of the intermediate member in the axial direction with each other in the axial direction, and that can be freely displaced in the axial direction; and that the push rod is displaced in the axial direction by an actuator. ,
The present invention relates to a pressure control valve provided with an on-off valve for displacing and opening a valve element provided in the valve element chamber. The seal structure of the present invention seals between the inner peripheral surface of the end of the through hole constituting the pressure control valve and the intermediate portion of the push rod.

In particular, in the seal structure of the pressure control valve according to the first aspect of the present invention, a plate made of an elastic material such as an elastomer such as rubber or vinyl is formed in an annular shape, and the inner diameter in a free state is formed. Is provided with a seal member smaller than the outer diameter of the intermediate portion of the push rod. Then, an outer diameter portion of the seal member is tightly fixed to the seal chamber side end of the intermediate member over the entire circumference, and an inner diameter portion of one side of the seal member is fixed to an intermediate portion of the push rod. The outer peripheral surface is tightly held down over the entire circumference.

Further, in the seal structure for a pressure control valve according to a second aspect of the present invention, a portion of one side of the seal member close to the inner diameter is provided on an outer peripheral surface of an intermediate portion of the push rod.
A pressure difference applied to both side surfaces of the seal member together with its own elasticity allows the seal member to be tightly suppressed over the entire circumference.

[0023]

According to the seal structure of the pressure control valve of the present invention constructed as described above, a part of the seal member formed of a circular plate made of an elastic material is elastically deformed, so that the axial direction of the push rod is changed. Irrespective of the displacement, the inner peripheral portion of the seal member is not slid with respect to the outer peripheral surface of the intermediate portion of the push rod, and the outer peripheral surface of the intermediate portion of the push rod and the through hole through which the push rod is inserted are inserted. Seal between the inner peripheral surface of the seal chamber side end. Therefore, in order to minimize the gap between the outer peripheral surface of the intermediate portion of the push rod and a part of the inner peripheral surface of the through hole, it is not necessary to control the size of the gap, and no troublesome manufacturing is required. I'm done. Further, since the portion of the seal member close to the inner diameter does not slide with respect to the outer peripheral surface of the intermediate portion of the push rod, the sliding resistance generated when the push rod is displaced in the axial direction is eliminated, and the pressure is reduced. Hysteresis during operation of the control valve can be reduced. Further, since the seal member does not slide with respect to the push rod, a part of the seal member is prevented from being worn, and the sealing property between the two peripheral surfaces is maintained for a long time. We can secure enough.

Further, according to the seal structure of the pressure control valve according to the second aspect of the present invention, the portion of the seal member close to the inner diameter on one surface is pushed by the pressure difference applied to both side surfaces of the seal member together with its own elasticity. Since the outer peripheral surface of the rod is tightly suppressed over the entire circumference, the sliding resistance can be more reliably suppressed, and the sealing performance between the two peripheral surfaces can be more reliably ensured.

[0025]

1 to 3 show an example of an embodiment of the present invention. This example is the second example of the conventional structure described above.
FIG. 4 shows an example in which the present invention is applied to a structure of an electromagnetic pressure control valve having improved efficiency similar to the example. The configuration and operation of the compressor part other than the pressure control valve are the same as those of the first example of the conventional structure shown in FIGS. . In addition, the arrangement state of each constituent member shown in FIGS. 1 to 3 is reversed left and right from the case of FIGS. However, this is only for convenience of explanation, and has nothing to do with left and right in the state of actual use.

A pressure control valve 34a which is an electromagnetic pressure control valve
Is provided in a head case 8 constituting the variable capacity compressor 1 (see FIG. 5). This pressure control valve 34
a comprises a casing 50 fixed inside the head case 8, an electromagnetic actuator 35a, and an on-off valve 36a opened and closed by the actuator 35a. The casing 50 is formed by attaching a pair of lids 52a and 52b to both ends of the tubular casing body 51 in the axial direction (vertical direction in FIGS. 1 to 3). The casing body 51 is fixed inside the head case 8. Also, at two positions on the outer peripheral surface of the intermediate portion of the casing body 51 that are separated from each other in the axial direction, concave grooves 54a and 54b are formed over the entire circumference, respectively, and are formed in these concave grooves 54a and 54b. O-rings 53a and 53b are mounted. Then, in a state where the casing body 51 is fixed inside the head case 8, the O-rings 53 a and 53 b are connected between the bottom surfaces of the concave grooves 54 a and 54 b and the inner peripheral surface of the head case 8. The space between the outer peripheral surface of the casing 50 and the inner peripheral surface of the head case 8 is sealed by being elastically compressed.

Inside the casing 50, an internal space 55 and an iron core chamber 56 are formed so as to be separated from each other in the axial direction, and a portion between the internal space 55 and the iron core chamber 56 is The through holes 57 extending in the directions communicate with each other. One of the lids 52a and 52b (the upper part in FIG. 1) has a net-like shape and connects the inside space 55 to the discharge chamber 11 which communicates with the inlet of the condenser 2 (FIG. 4). And a second through hole 6 described later.
4 prevents foreign matter from entering the interior of the device. Of course, the refrigerant and the lubricating oil can pass through the one lid 52a. Further, the inner side of the inner space 55 has a back side (FIG. 1).
Intermediate member 59 and the second intermediate member 60
And are internally fitted and fixed while being separated from each other in the axial direction. Thus, inside the internal space 55, in order from the back side,
A seal chamber 61, a valve chamber 62, and a lid chamber 63 are formed. The intermediate member 59 and the second intermediate member 60 are formed in such a manner that both axial end surfaces thereof penetrate each other,
A second through hole 64 and a through hole 65 are provided. The second through hole 64 among them corresponds to the through hole described in claim 1. The intermediate portion of the second through hole 64 is provided with a communication path 66 provided in a part of the intermediate member 59 and a second part provided in a part of the casing body 51 which is aligned with the communication path 66. The communication path 67 communicates with the swash plate chamber 17 (see FIG. 5).

In the case of this embodiment, a concave groove 68 is formed on a part of the outer peripheral surface of the intermediate member 59 over the entire length in the axial direction, and the valve chamber 62 communicates with the seal chamber 61 and the discharge chamber 11. And communicates. This concave groove 68 allows the ball 7 to be described later.
5 is transmitted into the seal chamber 61, and the lubricating oil fed together with the refrigerant in the discharge chamber 11 is
By being fed into a portion between the push rod 69 and the through hole 57 described later, the space between the push rod 69 and the through hole 57 is lubricated, and the movement of the push rod 69 is made smooth. In the illustrated example, the open end of the one lid 52a is engaged with the outer peripheral surface of an elastic deformation portion 83 provided at one end (the upper end in FIG. 1) of the casing body 51. Thereby, the elastic deformation portion 83 is slightly elastically deformed inward in the diametrical direction, so that the second intermediate member 60 internally fitted and fixed inside can be more reliably fixed.

The actuator 35a is inserted into the through-hole 57 and the second through-hole 64, and abuts a push rod 69 which can be freely displaced in the axial direction and a base end of the push rod 69. Further, an iron core 70 as a displacement member and a coil 71 arranged around the iron core 70 are provided. That is, the push rod 69 includes a small-diameter portion 72, a large-diameter portion 73, and a medium-diameter portion 74 in this order from the distal end side.
Each is formed in a continuous state. Then, the middle diameter portion 74 is inserted into the through hole 57 and the large diameter portion 73 is inserted into the second through hole 64 with a slight gap therebetween, and the push rod 69 is inserted. Is freely displaceable in the axial direction. Then, the base end of the push rod 69 is abutted against the center of one end face (the upper end face in FIG. 1) of the iron core 70. The iron core 70 is fitted into the iron core chamber 56 so as to be freely displaceable in the axial direction. Therefore, the iron core chamber 56 communicates with the seal chamber 61 via a minute gap existing between the through hole 57 and the push rod 69. The distal end surface of the push rod 69 is a ball 75 which is a valve body to be described later.
Facing. The coil 71 is sandwiched and fixed between the casing main body 51 and the other one of the lids 52a and 52b in a state of being wound on the outer peripheral surface of a holding ring 76 made of synthetic resin. The iron core 70
It is arranged around. Accordingly, the actuator 35a constitutes a solenoid that displaces the iron core 70 and the push rod 69 abutted on the iron core 70 in the axial direction based on the energization of the coil 71 or the stop thereof. The end of the conductor of the coil 71 is connected to a controller (not shown).

On the other hand, the on-off valve 36a is provided with a valve seat 77 provided at a peripheral edge of one end opening of the second through hole 64 in the valve body chamber 62 located at the tip end of the push rod 69.
A ball 75 as a valve body facing the valve seat 77 and a compression spring 78 as an elastic member are provided. The compression spring 78 is provided between the ball 75 and the second intermediate member 60, and elastically presses the ball 75 toward the valve seat 77. Therefore, when the tip of the push rod 69 displaces the ball 75 against the elasticity of the compression spring 78, the on-off valve 36a communicates with the communication passage 66 communicating with the valve body chamber 62 and the swash plate chamber 17. And the tip of the push rod 69 is connected to the ball 75
Is pressed, the ball 75 abuts on the valve seat 77 to cut off the communication between the valve body chamber 62 and the communication passage 66. Also, a part of the through hole 57, between the inner peripheral surface of the part closer to the seal chamber 61 than the part passed through the communication passage 66 and the outer peripheral surface of the intermediate part of the push rod 69,
Sealing is performed by the seal structure which is a feature of the present invention.

In particular, in the case of the seal structure of the pressure control valve of the present invention, the seal chamber 61, which is the other end surface of the intermediate member 59.
The cylindrical portion 79 extends axially from the outer peripheral edge of the side end face.
At the other end surface of the intermediate member 59, and at the other end side peripheral edge of the second through hole 64, an annular concave portion 80 is formed.
Is formed over the entire circumference. A seal member 81 is provided around the concave portion 80. The seal member 81 is made of a plate made of an elastic material such as an elastomer such as rubber or vinyl and formed in an annular shape, and has an inner diameter in a free state smaller than an outer diameter of an intermediate portion of the push rod 69. Then, the outer peripheral edge on one side of the seal member 81 is
The bent portions 82, 82 formed at a plurality of positions in the circumferential direction of the cylindrical portion 79, while being in close contact with the other end surface of the intermediate member 59 inside the cylindrical portion 79 over the entire circumference, are diametrically inward. It is bent toward. Thus, the outer peripheral edge of the seal member 81 is tightly fixed to the other end surface of the intermediate member 59 over the entire circumference. Further, the push rod 69 is inserted into the inside of the seal member 81 while elastically deforming the portion near the inner diameter of the seal member 81 toward the iron core chamber 56 along the outer peripheral surface of the push rod 69. Thereby, the cross-sectional shape of the seal member 81 is substantially L
The portion of the seal member 81 closer to the inner diameter is pressed over the entire outer periphery of the large diameter portion 73 provided at the intermediate portion of the push rod 69 by its own elasticity.
Further, when the pressure control valve 34a is used, the pressure in the discharge chamber 11 and the pressure in the swash plate chamber 17 lower than the pressure in the discharge chamber 11 are applied to both surfaces of the seal member 81. Therefore, the portion near the inner diameter of the seal member 81 is the large diameter portion 7 provided at the intermediate portion of the push rod 69.
3 and the elasticity of the two chambers 11 and 17
Is suppressed over the entire circumference.

The pressure control valve 34a provided with the above-described pressure control valve seal structure of the present invention operates as follows. That is, when the cooling load is large and the capacity of the compressor 1 needs to be increased, the iron core 70 is moved to the position shown in FIG. Displaced downward. In this state, the distal end of the push rod 69 whose base end abuts against the iron core 70 does not push the ball 75. Therefore,
The communication between the swash plate chamber 17 and the high-pressure chamber 11 is cut off. The refrigerant having the same pressure as that in the discharge chamber 11 existing in the seal chamber 61 is
It is not blocked by the seal member 81 and sent to the communication path 66 side. As a result, the high-pressure refrigerant vapor in the discharge chamber 11 is not sent into the swash plate chamber 17 and the pressure in the swash plate chamber 17 is reduced, which has been described in the first example of the conventional structure shown in FIG. Thus, the capacity of the compressor 1 increases. Conversely, when the capacity of the compressor 1 needs to be reduced, the iron core 70 is moved upward in FIG. 1 based on energization (or stop of energization) of the coil 71 by a command from the controller. Displace. In this state,
The tip of the push rod 69 pushes the ball 75 to separate the ball 75 from the valve seat 77. Therefore, the swash plate chamber 17 and the discharge chamber 11 communicate with each other. Thereby, the refrigerant vapor in the discharge chamber 11 is sent into the swash plate chamber 17, and the pressure in the swash plate chamber 17 increases.
In this state, as described in the first example of the conventional structure described above, the capacity of the compressor 1 decreases.

In the case of the present embodiment, the valve chamber 62 in which the ball 75 exists and the seal chamber 61 in which the seal member 81 exists are communicated. Thus, the pressure in the seal chamber 61 and the pressure in the high-pressure chamber 11 become equal. This pressure is applied to the through-hole 57.
It is introduced to the other end surface (the lower end surface in FIG. 1) of the iron core 70 through a minute gap existing between the iron core 70 and the push rod 69. Therefore, the pressure in the discharge chamber 11 is not applied to the resistance against the push rod 69 pressing the ball 75 to open the on-off valve 36a. That is, since the pressures acting directly on both sides of the ball 75 or via the iron core 70 and the push rod 69 cancel each other, the force required to displace the ball 75 to open the on-off valve 36a is Anything that can overcome the elasticity of the compression spring 78 is sufficient. Therefore, according to the pressure control valve 34a of the present embodiment, the electromagnetic force required to displace the push rod 69 and open the on-off valve 36a does not allow the valve body chamber 62 and the seal chamber 61 to communicate with each other. In comparison, the difference ΔP between the pressure in the discharge chamber 11 and the pressure in the swash plate chamber 17 and the cross-sectional area A of the second through hole 64 are reduced by the product (ΔP · A). The efficiency of the electromagnetic pressure control valve can be improved.

In particular, according to the seal structure of the pressure control valve of the present invention, the outer peripheral edge of the seal member 81 formed of an annular plate made of an elastic material is the other end surface of the intermediate member 59.
The sealing member 61 is fixed tightly over the entire circumference over the entire circumference.
9 and the sealing member 81
Is pressed tightly over the entire circumference due to the pressure difference applied to both sides of the plate. Therefore, when using the pressure control valve 34a,
A part of the seal member 81 is elastically deformed, so that a portion near the inner diameter of the seal member 81 does not slide on the outer peripheral surface of the intermediate portion of the push rod 69, and the outer peripheral surface of the intermediate portion of the push rod 69 , This push rod 6
9 can be sealed between the second through hole 64 and a part of the inner peripheral surface of the second through hole 64. That is, the push rod 69
However, when displaced upward in FIG. 1, as shown in FIG.
A part of the seal member 81 is elastically deformed while the part close to the inner diameter on one surface of the seal member 81 is kept in close contact with the outer peripheral surface of the large diameter portion 73 over the entire circumference, and the second through hole 64 is formed.
Into the concave portion 80 provided at the other end of the substrate. Therefore, the portion of the seal member 81 near the inner diameter does not slide on the outer peripheral surface of the large diameter portion 73 of the push rod 69. As a result, it is not necessary to control the size of the gap between the outer peripheral surface of the intermediate portion of the push rod 69 and the inner peripheral surface of the second through hole 64 in order to minimize the gap. It is not necessary to cause trouble. The sealing member 81
Of the push rod 69 does not slide on the outer peripheral surface of the intermediate portion of the push rod 69.
The hysteresis at the time of operating the pressure control valve 34a can be reduced by eliminating the sliding resistance generated when the cylinder 9 is displaced in the axial direction. Further, since the seal member 81 does not slide with respect to the push rod 69, a part of the seal member 81 is prevented from being worn and the sealing property between the two peripheral surfaces is improved. It can be sufficiently secured over the period.

Further, in the case of this embodiment, when the pressure control valve 34a is used, the pressure in the discharge chamber 11 and the pressure in the swash plate chamber 17 lower than the pressure in the discharge chamber 11 are formed on both side surfaces of the seal member. Pressure. Therefore, the sealing member 8
The portion closer to the inner diameter of 1 is suppressed over the entire periphery by the pressure difference between the two chambers 11 and 17 together with its own elasticity on the outer peripheral surface of the large diameter portion 73 provided at the intermediate portion of the push rod 69. Therefore, the sealing performance between the two peripheral surfaces can be more reliably ensured.

In the case of this embodiment, a cylindrical portion 79 is formed on the outer peripheral edge of the end surface of the intermediate member 59 on the seal chamber 61 side in a state of protruding in the axial direction. The bent portions 82 formed at the locations are bent inward in the diameter direction. Then, by this, the outer peripheral edge of the seal member 81 provided inside the cylindrical portion 79,
The other end surface of the intermediate member 59 is fixed tightly over the entire circumference. Therefore, in the case of this example, the fixing operation of the seal member 81 can be easily performed.

In the case of this embodiment, the sealing member 81
Of the intermediate member 59, which is a peripheral portion of the concave portion 80 formed at the other end of the second through hole 64, so as to be tightly fixed over the entire circumference. I have. However, in addition to such a structure, for example, by forming a locking groove on the entire inner peripheral surface of the concave portion 80 and locking the outer peripheral edge of the seal member 81 to the locking groove. It is also possible to fix the outer peripheral edge in the recess 80 tightly over the entire circumference. The point is that the sealing member 8 is attached to a portion of the other end of the intermediate member 59 which is continuous with the outer peripheral surface of the second through hole 64.
It suffices if the outer diameter portion 1 can be fixed tightly over the entire circumference.

The direction in which the portion of the seal member 81 close to the inner diameter is bent along the outer peripheral surface of the push rod 69 is the iron core chamber 56 side in this embodiment.
Depending on the structure of the pressure control valve, this bending direction may be on the opposite side. That is, when the high pressure side of the pressure applied to both surfaces of the seal member 81 is opposite to that in the present example (the communication passage 66 side with respect to the seal member 81 is the high pressure side), The portion near the inner diameter of 81 is bent to the opposite side (communication passage 66 side) from the case of this example. However, the axial dimension of the recess 80 is increased to prevent interference between the edge of the seal member 81 and the rear end face of the recess 80.

Further, the seal structure of the pressure control valve of the present invention is as follows.
It is characterized by a structure that seals between the push rod and a portion through which the push rod is inserted. For this reason, the present invention is not limited to the structure of the electromagnetic pressure control valve as in the structure of the present embodiment. For example, the structure of the pressure control valve using the diaphragm type actuator as in the conventional structure described above. Is also applicable.

[0040]

The seal structure of the pressure control valve according to the present invention is constructed and operates as described above, so that the hysteresis at the time of the operation of the pressure control valve can be reduced and the sealing property of the portion to be sealed can be extended. It can be sufficiently secured over the period. Further, it is not necessary to strictly control the size of the gap at the portion to be sealed, which contributes to the realization of an inexpensive pressure control valve without troublesome manufacturing.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a view similar to FIG. 2, showing the push rod displaced upward in FIG. 1;

FIG. 4 is a circuit diagram of a vapor compression refrigerator constituting the air conditioner for a vehicle.

FIG. 5 is a sectional view showing a conventional variable displacement compressor.

FIG. 6 is an enlarged view of a portion B in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Liquid tank 4 Expansion valve 5 Evaporator 6 Casing 7 Casing main body 8 Head case 9 End plate 10 Suction chamber 10a Part 11 Discharge chamber 12a Suction port 12b Discharge port 13 Drive shaft 14 Cylinder 15 Partition plate 16 Piston 17 Slant Plate chamber 18 Sleeve 19 Support bracket 20 Support cylinder 21 Swash plate 22a, 22b Radial needle bearing 23a, 23b Thrust needle bearing 24 Link arm 25 Pivot shaft 26 Compression spring 27 Sliding shoe 28 Spherical concave surface 29 Guide part 30 Suction port 31 Discharge port 32 Suction valve 33 Discharge valve 34, 34a Pressure control valve 35, 35a Actuator 36, 36a Open / close valve 37 Case 38 Diaphragm 39 Atmospheric pressure chamber 40 Pressure introduction chamber 41 Push plate 42 Compression spring 43 Valve seat 44 Ball 45 Compression spring 46 Communication passage 47 Push rod 48 Through hole 49 Intermediate member 50 Casing 51 Casing body 52a, 52b Lid 53a, 53b O-ring 54a, 54b Groove 55 Internal space 56 Iron core chamber 57 Through hole 58 Communication path 59 Intermediate member 60 Second intermediate member 61 Seal chamber 62 Valve body chamber 63 Cover body chamber 64 Second through hole 65 Through hole 66 Communication path 67 Second communication path 68 Depressed groove 69 Push rod 70 Iron core 71 Coil 72 Small diameter part 73 Large diameter part 74 Medium diameter part 75 Ball 76 Retaining ring 77 Valve seat 78 Compression spring 79 Cylindrical part 80 Recessed part 81 Sealing member 82 Bent part 83 Elastic deformation part

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hisashi Hirota 1211-4, Nugita-cho, Hachioji-shi, Tokyo

Claims (4)

[Claims] An intermediate member provided in a casing communicates a valve body chamber, a seal chamber, and both axial end surfaces of the intermediate member provided on both axial sides of the intermediate member. A push rod that is inserted into the through-hole and that can be freely displaced in the axial direction; and that the push rod is displaced in the axial direction by an actuator, thereby displacing the valve element provided in the valve element chamber. A pressure control valve including an on-off valve that opens and closes, a seal structure of a pressure control valve that seals between an inner peripheral surface of the seal chamber side end of the through hole and an outer peripheral surface of an intermediate portion of the push rod, A plate member made of an elastic material is formed in a ring shape, and a seal member having an inner diameter in a free state smaller than an outer diameter of an intermediate portion of the push rod is provided. The serial seal chamber side end portion with closely fixed over the entire periphery, the inner diameter portion near one side of the seal member,
A pressure control valve seal structure characterized in that the push rod is pressed tightly over the entire outer circumference of an intermediate portion of the push rod. 2. The sealing member has a portion close to the inner diameter on one side thereof and the outer peripheral surface of an intermediate portion of the push rod tightly suppressed over the entire periphery by a pressure difference applied to both side surfaces of the sealing member together with its own elasticity. A seal structure for a pressure control valve according to claim 1. 3. A concave portion is formed over the entire circumference at an end of the intermediate member on the seal chamber side, and a portion of the seal member close to the outer diameter is formed.
3. The pressure control valve seal structure according to claim 1, wherein the pressure control valve is tightly fixed to a peripheral portion of the concave portion or an inner peripheral surface of the concave portion over the entire periphery. 4. A cylindrical portion is formed around the recess at the end of the intermediate member on the seal chamber side so as to protrude in the axial direction.
4. The seal structure for a pressure control valve according to claim 3, wherein a bent portion formed in a part of the cylindrical portion in a circumferential direction is bent inward in a diametrical direction.