JP2000249051A - Control valve for variable displacement swash plate type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate assembly by simplifying valve structure while employing high pressure correction structure, in the internal control valve of a variable displacement swash plate type compressor. SOLUTION: An actuating body 54 fixed at a diaphragm (a pressure-sensitive body) 57 displaceable according to a suction pressure Ps is contained in a valve housing 60. An actuating body 54 comprises a valve element part 51 formed at its tip part; a rod part 52; and a sleeve-type high pressure correction part 53 fitted externally on the rod part. The high pressure correction part 53 transmits a change of a discharge pressure Pd to the diaphragm 57. The diameter of actuating body 54 is stepwise increased from a tip part (on the valve element part 51 side) toward a base end part (on the high pressure correction part 53 side). This constitution facilitates manufacture of the actuating body 54 and assembly to a valve housing 60.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement type swash plate type compressor, which is provided in a bleed passage connecting a crank chamber and a suction pressure area, and controls the amount of gas released from the crank chamber. The present invention relates to a control valve for changing a discharge capacity of a valve and guiding a suction pressure to a set suction pressure.

[0002]

2. Description of the Related Art As a compressor for a refrigerant gas used in a vehicle air conditioner, the displacement of a compressor from a compressor can be changed by controlling the angle of a swash plate provided to be tiltable in a crank chamber of the compressor. 2. Description of the Related Art A variable displacement swash plate type compressor is known. In this type of compressor, the swash plate angle is adjusted by controlling the pressure of the gas introduced into the crank chamber (crank pressure Pc) using a special control valve. One of the control methods of the crank pressure is a so-called vent side control, which is a crank chamber and a suction chamber (communicating with the outlet side of the evaporator of the external refrigerant circuit).
The crank pressure is adjusted by controlling the amount of gas released from the crank chamber by a bleed-side control valve provided in the middle of the bleed passage. The vent-side control valve is a valve body that is operatively connected to a pressure-sensitive body that can be displaced in response to a change in the pressure of the suction chamber (suction pressure Ps) corresponding to the outlet-side pressure of the evaporator. A so-called internal control system that autonomously adjusts the valve opening of the valve is often adopted. In such a vent-side internal control valve, a set suction pressure, which is a control target pressure, is set in advance depending on how much urging force is applied to the pressure-sensitive body, and a suction pressure Ps corresponding to the outlet-side pressure of the evaporator is set.
The valve opening is autonomously feedback-controlled so that the pressure becomes the set suction pressure.

When the pressure of the refrigerant gas discharged from the compressor to the external refrigerant circuit (discharge pressure Pd) is large, the pressure loss in the piping of the external refrigerant circuit is not negligible, and the actual outlet pressure of the evaporator is reduced. A gap is likely to occur between Ps' and the suction pressure Ps. That is, when the discharge pressure Pd increases, the suction pressure Ps appears smaller than the actual evaporator outlet pressure Ps'. Such Ps
A technique for compensating for the inevitable gap between the pressure Ps and the pressure Ps ′ and realizing the valve opening degree control that fully considers the actual evaporator outlet pressure Ps ′ is called “high pressure correction”. For example, by adopting a configuration in which a change in the discharge pressure Pd can be transmitted to the pressure-sensitive body, the set suction pressure can be corrected to decrease with an increase in the discharge pressure Pd, thereby being affected by the occurrence of the gap. And attempts to stably control the evaporator outlet side pressure Ps' (Japanese Patent Publication No. 3-53474).
No.).

Japanese Patent Laying-Open No. 5-52182 discloses a control valve incorporating the above-described concept of high-pressure correction.
The control valve includes a pressure displacement converter 3 having a diaphragm 8 (pressure sensing element), a crank chamber pressure generator 24 having a ball valve element 39 and a valve seat 34, and a control valve disposed between the two sections 3, 24. And a displacement transmission unit 13 composed of a lower abutment 14 and a rod 15 is provided between the diaphragm 8 and the ball valve body 39.

[0005]

In the control valve disclosed in Japanese Unexamined Patent Application Publication No. Hei 5 (1994), since the valve body 39 has a ball shape, the ball valve body 39 and the rod 15 must be provided as separate members. Inevitably, the displacement transmission structure to the ball valve body 39 and the structure of the high-pressure correction unit 23 located between the diaphragm 8 and the ball valve body 39 become complicated.
In addition, for the sake of assembly, the arrangement of the ball valve element 39 in the crank chamber pressure generating section and the arrangement of the rod 15 in the chamber 27 of the high pressure correction section must be performed separately, which requires a large number of assembly steps. Tend to be.

An object of the present invention is to provide a control valve for a variable displacement type swash plate type compressor which has a simplified structure and is easy to assemble while adopting a high pressure correction structure.

[0007]

According to a first aspect of the present invention, there is provided a bleed passage which connects a crank chamber and a suction pressure region of a variable displacement swash plate type compressor, and controls the amount of gas released from the crank chamber. A control valve for changing the discharge capacity of the compressor to guide the suction pressure to the set suction pressure, the valve seat provided in the bleed passage, the set suction pressure of the control valve, and the suction pressure. A pressure-sensitive displacement mechanism that is displaced in response to a change in the pressure, a valve body that is provided to be able to contact and separate from the valve seat and that can adjust the degree of opening of the bleed passage, A rod portion for transmitting to the body portion; and a high-pressure correction portion for transmitting discharge pressure to the pressure-sensitive displacement mechanism to correct the set suction pressure, wherein the valve body portion and the rod portion are integrated. Along with the cross-sectional area of the valve body portion is set so as not to exceed the cross-sectional area of the rod portion, and The high-pressure correcting section is characterized by having a pressure receiving surface of the discharge pressure by being provided as a large-diameter portion than the diameter of the rod portion at the periphery of the rod portion.

According to this configuration, the number of members is reduced by integrating the valve body and the rod. A high-pressure correction unit that moves in the direction of displacement of the pressure-sensitive displacement mechanism within the control valve;
In order to establish a relationship in which the rod section and the valve body section gradually reduce the cross-sectional area from the high-pressure correction section toward the valve body section,
These movable parts can be easily manufactured. In addition, due to the shape characteristic that each movable portion gradually reduces the cross-sectional area, it becomes possible to insert them into the control valve from one direction. Therefore, according to this control valve, while employing the high-pressure correction structure, the structure is simplified and the assembling becomes easier than in the past. As will be described later, the valve body, the rod, and the high-pressure correction unit according to claim 1 are disposed between the pressure-sensitive displacement mechanism and a valve seat, and are operatively connected to the pressure-sensitive displacement mechanism. It is preferable to configure Further, it is preferable that the valve body and the rod are constituted by one member.

According to a second aspect of the present invention, in the control valve of the variable displacement type swash plate type compressor according to the first aspect, the diameter of the valve body is equal to or smaller than the diameter of the rod. The cross-sectional area of the valve body does not exceed the cross-sectional area of the rod. The second aspect refers to a more preferable relationship between the valve body and the rod.

According to a third aspect of the present invention, in the control valve of the variable displacement type swash plate type compressor according to the first or second aspect, the rod portion has a pressure-sensitive structure between the valve seat and the pressure-sensitive displacement mechanism. The valve body is disposed movably in the direction of displacement of the displacement mechanism, the valve body is provided at a valve seat-side end of the rod, and the high-pressure correction unit is provided at a pressure-sensitive displacement mechanism-side end of the rod. It is characterized by having. Claim 3 refers to a more preferable relationship among the three of the valve body, the rod, and the high-pressure correction unit. It is more preferable that the valve body, the rod, and the high-pressure correction unit have a common axis, and a cross-sectional shape orthogonal to the common axis is a concentric circle centered on the common axis.

According to a fourth aspect of the present invention, in the control valve for a swash plate type variable displacement compressor according to any one of the first to third aspects, the valve body and the rod are separated from the high-pressure compensator. The high-pressure compensator is formed of a member, and the high-pressure compensator is externally fitted to the rod. According to this configuration, a relatively expensive material having excellent durability such as abrasion resistance is used for an integral body of the valve body and the rod portion, while a relatively inexpensive material is used for the high-pressure compensator made as a separate member. By using a suitable material, it is possible to reduce the manufacturing cost. The mutually fitted high-pressure correction unit and rod unit may be relatively slidable.

According to a fifth aspect of the present invention, there is provided a control valve for a variable displacement swash plate type compressor according to any one of the first to third aspects, wherein the valve body, the rod, and the high-pressure compensator are provided. Is composed of one member.
According to this configuration, the number of members is further reduced by configuring the three members as one member. In addition, there is no change in the relationship in which the diameter or the cross-sectional area is gradually reduced toward the valve body. Even if the three members are formed as one member, each part can be easily manufactured and the number of assembly steps is reduced.

According to a sixth aspect of the present invention, in the control valve of the variable displacement type swash plate type compressor according to any one of the first to fifth aspects, the valve body has a needle shape. I do. By forming the valve body portion into a needle shape, the valve body portion becomes tapered, and processing of the valve body portion and insertion and assembly into the valve housing are further facilitated.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a displacement control valve incorporated in a variable displacement type swash plate type compressor mounted on a vehicle will be described below with reference to FIGS.

(Outline of Compressor Body and External Refrigerant Circuit) As shown in FIG. 1, the variable displacement type swash plate type compressor has a cylinder block 1, a front housing 2 joined to the front end thereof, and a cylinder block 1. And a rear housing 4 joined to the rear end via a valve body 3. These 1, 2, 3, and 4 are joined and fixed to each other by a plurality of through bolts (not shown), and constitute a housing of the compressor. A crank chamber 5 is defined in a region surrounded by the cylinder block 1 and the front housing 2. A drive shaft 6 is rotatably supported in the crank chamber 5 by a plurality of radial bearings mounted in the housing. A coil spring 7 and a rear thrust bearing 8 are disposed in a central concave portion of the cylinder block 1. On the other hand, the rotary support 1
The front thrust bearing 9 is disposed between the rotary support 11 and the inner wall surface of the front housing 2. The drive shaft 6 is thrust supported by a rear bearing 8 and a front bearing 9 urged forward by a coil spring 7.

The front end of the drive shaft 6 is operatively connected to a vehicle engine E as an external drive source via an electromagnetic clutch 40. The electromagnetic clutch 40 is connected to the front housing 2
A pulley 42 rotatably supported by a bearing 41 on a front cylindrical portion of the drive shaft 6, an annular solenoid coil 43, and a front end region of the drive shaft 6 are slidably moved forward and backward while being urged by a leaf spring 44. Armature 45 provided.
FIG. 1 shows the armature 4 against the urging force of the leaf spring 44.
5 shows a state in which 5 is joined to the end face of the pulley 42. When the armature 45 is attracted and joined to the end face of the pulley 42 by electromagnetic force generated by energizing the coil 43, the driving force of the engine E is transmitted to the drive shaft 6 via the power transmission belt 46, the pulley 42 and the armature 45. You. If the electromagnetic force disappears due to the stoppage of the current supply to the coil 43, the armature 45 is separated from the pulley 42 by the urging force of the leaf spring 44, and the power transmission is cut off. As described above, the engine power is selectively transmitted to the drive shaft 6 based on the control of energizing the coil 43.

Further, a swash plate 12 serving as a cam plate is accommodated in the crank chamber 5. The swash plate 12 has a through hole formed in the center thereof, and the drive shaft 6 is inserted through the through hole. The swash plate 12 is operatively connected to the rotation support 11 and the drive shaft 6 via a hinge mechanism 13 as a connection guide mechanism. The hinge mechanism 13 includes a support arm 14 having a guide hole protruding from a rear surface of the rotary support 11 and a swash plate 1.
2 and a guide pin 15 with a spherical head protruding from the front surface of the second. Then, by the linkage between the support arm 14 and the guide pin 15 constituting the hinge mechanism 13 and the contact with the drive shaft 6 in the central insertion hole of the swash plate 12,
The swash plate 12 is rotatable in synchronization with the drive shaft 6 and is capable of tilting with respect to the drive shaft 6 while sliding the drive shaft 6 in the axial direction.

A coil-shaped inclination-reducing spring 16 is provided on the drive shaft 6 between the rotary support 11 and the swash plate 12. The spring 16 urges the swash plate 12 in a direction approaching the cylinder block 1 (that is, a direction in which the inclination angle decreases). A circlip 17 is fixed on the drive shaft 6 behind the swash plate 12, and the circlip 17 restricts the swash plate 12 from retreating further, thereby reducing the minimum inclination angle of the swash plate 12 (for example, 3 to 3).
5 °). On the other hand, the maximum inclination angle of the swash plate 12 is determined when the counterweight portion 12a of the swash plate 12 abuts on the regulating portion 11a of the rotary support 11.

As shown in FIG. 1, the cylinder block 1 has a plurality of cylinder bores 1a surrounding the drive shaft 6.
A single-headed piston 18 is reciprocally accommodated in each cylinder bore 1a.
The end of each piston 18 is moored to the outer periphery of the swash plate 12 via a pair of shoes 19, and the piston 19 and the swash plate 12 are operatively connected by the shoes 19.

Between the valve body 3 and the rear housing 4, a suction chamber 21 located in the center area and a discharge chamber 22 surrounding the suction chamber 21 are defined. The valve body 3 has a suction port 23 and a port 2 corresponding to each cylinder bore 1a.
3 is formed, and a discharge port 25 for opening and closing the discharge port 25 and a discharge valve 26 for opening and closing the port 25 are formed.
Through the suction port 23, the suction chamber 21 and each cylinder bore 1
a, and each cylinder bore 1 a is communicated with the discharge chamber 22 through the discharge port 25.

In the swash plate type compressor shown in FIG. 1, when the drive shaft 6 is rotated by the power supply from the engine E, the swash plate 12 inclined at a predetermined angle is rotated. Then, each piston 18 is reciprocated at a stroke corresponding to the inclination angle of the swash plate, and in each cylinder bore 1a, the suction chamber 21 (suction pressure P
s area), suction and compression of the refrigerant gas from the
The discharge of the compressed refrigerant gas to the (area of the discharge pressure Pd) is sequentially repeated.

The tilt angle of the swash plate 12 of the compressor is determined by the moment of the rotational motion based on the centrifugal force at the time of rotation of the swash plate, the moment by the spring force based on the urging action of the tilt angle reducing spring 16, and the gas pressure. There are three moments.
The product of inertia of the swash plate 12 is set such that the moment of the rotational motion always acts in the direction of increasing the tilt angle. On the other hand, the moment due to the gas pressure is the mutual reaction between the compression reaction force acting on the piston of the cylinder bore in the compression stroke, the internal pressure of the cylinder bore in the suction stroke, and the internal pressure of the crank chamber 5 (crank pressure Pc) which corresponds to the piston back pressure. This is a moment generated based on the relationship, and acts in the direction of decreasing the tilt angle. In the present embodiment, by maintaining the crank pressure Pc at a high level, the sum of the moment due to the gas pressure and the moment due to the spring force of the inclination reducing spring 16 exceeds the moment in the inclination increasing direction due to the rotational motion, and the swash plate 12 Is designed to be set to the minimum inclination. Also, the crank pressure P
By appropriately adjusting c, the sum of the moment due to the gas pressure and the moment due to the spring force is balanced with the moment of the rotational motion, and the inclination angle of the swash plate 12 is set to an arbitrary angle between the minimum inclination angle and the maximum inclination angle. It can be set. Thus, the inclination of the swash plate 12 is determined based on the control of the crank pressure Pc, and the stroke of each piston 18, that is, the displacement of the compressor is variably adjusted according to the inclination.

The mechanism for controlling the crank pressure Pc is as follows:
It is constituted by various passages 27A, 27B, 28 and 29 and a capacity control valve 50 provided in the compressor housing as shown in FIGS. That is, the compressor housing is provided with bleed passages 27A and 27B that connect the crank chamber 5 and the suction chamber 21, and a capacity control valve 50 is provided in the middle of the bleed passage. The displacement control valve 50 controls the degree of communication between the bleed passages 27A and 27B to regulate the amount of gas released from the crank chamber 5 to the suction chamber 21. Control valve 5
Details of 0 will be described later. The bleed passage 27B downstream of the control valve 50 also functions as a pressure detection passage for guiding the suction pressure Ps as a detection pressure to the control valve 50.
Further, the compressor housing is provided with a pressure guiding passage 28 connecting the discharge chamber 22 and the control valve 50 and an auxiliary air supply passage 29 connecting the discharge chamber 22 and the crank chamber 5. The auxiliary air supply passage 29 has a fixed throttle 29a in the middle thereof. The gas supply to the crank chamber 5 mainly depends on the so-called blow-by gas leaking into the crank chamber 5 from a gap between the piston 18 and the cylinder bore 1a in the compression stroke. It is preferable to provide an auxiliary air supply passage 29 with a throttle 29a.

The discharge chamber 22 and the suction chamber 2 of the compressor shown in FIG.
1 is connected via an external refrigerant circuit 30. The external refrigerant circuit 30 forms a cooling circuit of the vehicle air conditioner together with the compressor. The external refrigerant circuit 30 includes a condenser (condenser) 31, a temperature-type expansion valve 32, and an evaporator (evaporator) 33. The opening degree of the expansion valve 32 is feedback-controlled based on the detected temperature of the temperature-sensitive cylinder 34 provided on the outlet side of the evaporator 33 and the evaporation pressure (specifically, the pressure at the evaporator outlet). The liquid refrigerant corresponding to the load is supplied to the evaporator 33 to adjust the flow rate of the refrigerant in the external refrigerant circuit 30.

(Details of Displacement Control Valve) As shown in FIG. 2, the displacement control valve 50 for adjusting the amount of gas released from the crank chamber 3 has a first valve housing 6 occupying the lower half of the control valve.
0, and a second valve housing 70 having a bowl-shaped cross section joined to an upper portion thereof.

As shown in FIGS. 2 and 3, the first valve housing 60 is a cylindrical body extending in the axial direction (vertical direction in the figure), and has a stepped inside from the bottom in the axial direction. Interior space 6 that expands the diameter (or cross-sectional area)
1, 62, 63 and two insertion holes 64,
65 and three types of ports 6 extending in the axial or radial direction
6, 67, 68 are formed. As shown in FIG.
In the state of the first valve housing 60 alone before the control valve assembly, among the plurality of inner chamber spaces, the lowermost first inner chamber space 61 and the intermediate position of the second inner chamber space 62 are rod-shaped. The space 62 for the second inner room at the intermediate position and the space 63 for the third inner room at the uppermost position are connected via the high-pressure correcting unit insertion hole 65. First inner room space 6
1. Each of the rod portion insertion hole 64, the second inner space space 62, the high-pressure correction portion insertion hole 65, and the third inner space space 63 has a circular cross section (transverse cross section) perpendicular to the common axis. And these circular shapes are concentric around the common axis. In addition, the first inner chamber space 61 and the rod portion insertion hole 64 have the same inner diameter d1, and the second inner room space 62 and the high-pressure correction unit insertion hole 65 have the same inner diameter d2. The inner diameter d2 is larger than the inner diameter d1 (d1 <d2).

Further, a first port 66 is formed immediately below the first inner chamber space 61 so as to penetrate the valve housing 60 in the axial direction. A plurality of second ports 67 penetrating in the direction are formed. Further, a plurality of third ports 68 penetrating the valve housing 60 in the radial direction are formed on the side of the second inner chamber space 62. When the control valve 50 is attached to the compressor, as shown in FIG. 2, the first port 66 communicates with the crank chamber 5 via the upstream bleed passage 27A, and each second port 67 communicates with the downstream bleed passage 27B. Through the suction chamber 2
1, each third port 68 communicates with the discharge chamber 22 via the pressure guiding passage 28. The annular step 69 of the valve housing 60 formed between the first port 66 and the first inner space 61 is used as a valve seat and a spring seat.

As shown in FIGS. 2 and 3, in the first valve housing 60, the valve body 51, the rod 52, and the high pressure compensator are arranged from the third interior space 63 toward the first port 66. A substantially pin-shaped operating body 54 composed of the portion 53 is inserted. The valve body 51 is a portion that functions as a needle valve body that has been machined into a tapered shape, and is completely integrated with the rod 52 (into a single member). The pin body including the valve body 51 and the rod 52 is made of a metal material having excellent durability such as wear resistance. The high-pressure correction unit 53 is a substantially sleeve-shaped part, and is provided as a member separate from the pin bodies (51, 52). The high-voltage correction unit 53 is made of a metal material or a resin material (for example, engineering plastic or the like) that is less expensive than the metal material forming the pin body. The high pressure correcting section 53 in the form of a sleeve is
2 are fitted around the upper end (the end opposite to the valve body 51). This external fitting is performed by the rod portion 52 and the high-pressure correction portion 5.
The fitting may be such that the valve body 51, the rod 52, and the high-pressure correcting unit 53 can move together as a unit. Each of the valve element 51, the rod 52, and the high-pressure correction unit 53 has a circular cross section (transverse cross section) perpendicular to the common axis, and these circular shapes are centered on the common axis. It has a concentric shape. In addition, the outer diameter of the rod portion 52 is
4, and the outer diameter of the main part of the high-pressure correction section 53 substantially matches the inner diameter d2 of the high-pressure correction section insertion hole 65.

As shown in FIG. 2, the operating body 54 includes a sub-holding spring 55 disposed in the first inner space 61 and a main holding spring 56 disposed in the second inner space 62. It is disposed in the first valve housing 60 so as to be movable in the axial direction while being elastically supported. Both holding springs 55 and 56 are
The entire operating body 54 is lifted to prevent the needle-shaped valve body 51 from biting into the valve seat 69.

In the state shown in FIG. 2, a part of the rod 52 is inserted into the rod insertion hole 64, and the first hole of the first valve housing 60 is The inner room space 61 is partitioned as a valve chamber 61 and is isolated from the second inner room space 62. Thus, between the crank chamber 5 and the suction chamber 21, the upstream side bleed passage 27A, the first port 66, the valve seat 69, the valve chamber 6
A bleed path including the first and second ports 67 and the downstream bleed path 27B is configured. The valve body 51 adjusts the degree of opening of the bleed passage in accordance with the position in the valve chamber 61. The suction pressure Ps reaches the valve chamber 61 via the second port 67.

The high-pressure compensating portion 53 fitted around the rod portion 52 is inserted into the high-pressure compensating portion insertion hole 65, and the rod portion 52 and the high-pressure compensating portion 53 substantially seal the insertion hole 65. The space 62 for the second inner chamber of the first valve housing 60 is partitioned as a high-pressure correction chamber 62 and is isolated from the space 63 for the third inner chamber. This high-pressure correction chamber 6
2, the discharge pressure Pd is applied via the third port 68. The lower end surface 53b of the high-pressure correction unit 53 is exposed (or exposed) in the high-pressure correction chamber 62 and functions as a pressure receiving surface for the discharge pressure Pd. Therefore, based on the pressure received on the pressure receiving surface 53b, at least the high pressure correction unit 53 is urged upward with an urging force corresponding to the magnitude of the discharge pressure Pd.

A second valve housing 70 is joined to an upper portion of the first valve housing 60 via a diaphragm 57 as a pressure-sensitive body. That is, the diaphragm 57 interposed in the joint region between the two valve housings 60 and 70 is provided.
However, the internal space created by the joining is divided into upper and lower parts. The lower space of the diaphragm 57 is exactly the space 63 for the third inner chamber, and the space 63 for the third inner chamber is partitioned by the diaphragm 57 as a pressure-sensitive chamber 63. An upper end of the rod portion 52 and an upper end 53a of the high-pressure correcting section 53 are arranged in the pressure-sensitive chamber 63, and both upper ends are fixed to the lower surface of the diaphragm 57. High voltage compensator 5
3 has an outer diameter d2 of a main part of the high-pressure correction unit.
It is a part with a larger diameter than that. This is to secure a large contact area with the diaphragm 57 to facilitate the mounting. In the first valve housing 60,
A communication passage 58 for communicating the pressure-sensitive chamber 63 with the valve chamber 61 and the second port 67 is formed. Communication passage 58, second
The port 67 and the downstream-side bleed passage 27B constitute a pressure detection passage that guides the suction pressure Ps to the pressure-sensitive chamber 63.

As shown in FIG. 2, an adjuster (adjuster) 71 is screwed on the upper portion of the second valve housing 70. A hole 71a is formed in the center of the adjustment body 71, and the inside of the second valve housing (the space above the diaphragm 57) is opened to the atmosphere through the hole 71a. In this embodiment, the atmospheric pressure is used as the reference pressure. Second
A setting spring 72 is provided in the valve housing 70,
One end (upper end) of the setting spring 72 is hooked on the adjusting body 71, and the other end (lower end) is hooked on the spring receiver 73. As a result, the urging force of the setting spring 72 is applied to the diaphragm 57 via the spring receiver 73, the ball 74, and the ball receiver 75 (75 is attached to the upper surface of the diaphragm 57). Thus, the atmospheric pressure as the reference pressure and the setting spring 72
Determines the set suction pressure Pset of the control valve 50. The set suction pressure Pset can also be changed by adjusting the screwing position of the adjusting body 71 to the second valve housing 70. In this embodiment, the diaphragm 57, the adjusting body 71, the setting spring 72, the spring receiver 73,
The set suction pressure P is set by the ball 74 and the ball receiver 75.
A pressure-sensitive displacement mechanism that determines the set and that performs displacement operation of the operating body 54 including the valve body 51 in response to a change in the suction pressure Ps is configured.

(Operation) When the compressor shown in FIG. 1 is operated, the gas supply to the crank chamber 3 is secured by the blow-by gas and the high-pressure gas flowing through the auxiliary air supply passage 29 in FIG. The capacity control valve 50 functions as an internal control valve. That is, the pressure-sensitive displacement mechanism including the diaphragm 57 operates in response to the fluctuation of the suction pressure Ps guided from the suction chamber 21 to the pressure-sensitive chamber 63, and the valve body of the operating body in the valve chamber 61. Positioning of 51 is performed. As a result, the valve body 51
Bleeding path according to the position of (27A → 61 → 27B)
The opening of the control valve 50 is controlled at the crank pressure Pc
Is adjusted. Then, as described above, the inclination angle of the swash plate 12 is determined according to the crank pressure Pc, and the displacement of the compressor is changed.

The pressure-sensitive displacement mechanism in the internal control valve operates the valve body 51 so that the suction pressure Ps as the detection pressure is substantially maintained at a predetermined pressure value. The set suction pressure Pset is equivalent to the predetermined pressure value. In the first place, the role of the variable displacement compressor incorporated in the cooling circuit of the air conditioning system is to stabilize the outlet pressure Ps' of the evaporator 33, which reflects the cooling load, near a desired value. For this reason, the pressure in the suction chamber (suction pressure Ps) substantially equal to the outlet pressure Ps ′ of the evaporator 33 is sampled, and the swash plate angle (ie, the discharge capacity) is controlled using a control valve so as to maintain this at the set suction pressure Pset. Feedback control. However, as described above, when the discharge pressure Pd from the compressor is large, a gap is formed between the actual outlet pressure Ps ′ of the evaporator 33 and the suction chamber pressure Ps due to the pressure loss in the piping of the external refrigerant circuit 30. Occurs. A configuration for compensating for the inevitable gap between Ps and Ps' is the high-voltage correction unit 53. As the discharge pressure Pd increases, the upward biasing force of the high-pressure correction unit 53 greatly reduces the downward biasing force of the setting spring 72 of the pressure-sensitive displacement mechanism. That is, the high pressure correction unit 53 outputs the discharge pressure Pd
The set suction pressure Pset of the control valve 50 is reduced and corrected in accordance with the magnitude of. Therefore, even when the discharge pressure Pd is high, the opening of the control valve 50 can be controlled so that the actual evaporator outlet pressure Ps' is stabilized near the desired value.

(Effects) According to the present embodiment, the following effects can be obtained. The operating body 54 that constitutes the control valve 50 includes a valve body 51,
A rod portion 52 and a high-pressure correction portion 53 are formed so that their diameter (or cross-sectional area) decreases stepwise from the diaphragm 57 side toward the valve body portion 51. Inner room space 61, 62, 6
3 and the insertion holes 64 and 65 are also formed stepwise according to the shape of the operating body 54. Therefore, the operating body 54 and the first valve housing 6 as valve components
0 becomes very easy to make, and the number of parts can be reduced as compared with the conventional case. If the number of components is reduced, the number of sliding points between components is reduced, which is advantageous for improving durability.

As described above, due to the shape characteristic that each component 54, 60 of the control valve 50 changes its diameter or cross-sectional area in a stepwise manner, the operating body 54 previously integrated in the preprocess is The first valve housing 60 can be inserted in one direction from the upper opening to the lower side (see FIG. 3). Therefore, assembling of the control valve becomes easier than before, and the number of assembling steps can be significantly reduced to reduce costs.

In the operating body 54 of FIGS. 2 and 3, the valve body 51 and the rod 52 and the substantially sleeve-shaped high-pressure correction unit 53 are formed as separate members. Uses a relatively expensive metal material having excellent durability, while the high-pressure correction unit 53 that does not require much durability can use a relatively inexpensive metal or resin material. For this reason, it is possible to design more advantageous in terms of cost. In addition, the valve body 5
The reason why expensive materials are used for 1 is that the valve seat 69 is not damaged as much as possible.

A high-pressure compensator 53 is provided around the rod 52.
Is externally fitted, so that the dimension of the control valve 50 can be prevented from becoming too long in the axial direction (large design freedom). Since the high-pressure correction unit 53 is fitted around the rod 52, the degree of the high-pressure correction by the discharge pressure Pd is relatively free without being restricted by the diameter of the valve body 51 or the inner diameter of the valve chamber 61. Can be set to

In the control valve of FIG. 2, the rod 52 has a certain length, and the contact length between the inner peripheral surface of the rod insertion hole 64 and the outer peripheral surface of the rod 52 is relatively long.
Therefore, the sealing performance in the rod portion insertion hole 64 can be ensured without providing a special sealing member. The same can be said for the contact portion between the inner peripheral surface of the high-pressure correction unit insertion hole 65 and the outer peripheral surface of the high-voltage correction unit 53.

Since the operating body 54 is elastically supported using the two main and sub-holding springs 56 and 55, the load load per holding spring can be reduced. (Another Example / Definition) The embodiment of the present invention may be modified as follows.

In the embodiment shown in FIGS. 2 and 3, the high-pressure correcting section 53 is externally fitted to the rod section 52 to form the operating body 54. However, as shown in FIG. ,
The entire operation body 54 including the rod portion 52 and the high-pressure correction portion 53 may be configured as a single member made of a single material (a single solid body in FIG. 4). In this case, the auxiliary holding spring 55 provided in the valve chamber 61 can be omitted, and the internal structure of the valve chamber 61 can be simplified. In addition, the three parts 5
The number of members can be further reduced by completely integrating the components 1, 52 and 53. Even when the operating body 54 is formed as a single member, the three portions 51, 52, and 53 have a shape in which the diameter (or cross-sectional area) changes stepwise from the lower end to the upper end. Is not impaired. The capacity control valve having the configuration shown in FIG. 4 also has substantially the same operation and effect as the above embodiment.

In FIGS. 2 and 4, the valve body 51 provided at the lower end (tip) of the operating body 54 has a needle valve shape. Instead of this, as shown in FIG. 5, the tip of the valve body 51 may have a flat end surface shape. Also, as shown in FIG.
The distal end of the valve body 51 may have a hemispherical shape. That is, the valve body portion 51 of the operating body 54 only needs to have a diameter (or cross-sectional area) that does not exceed at least the diameter (or cross-sectional area) of the rod portion 52.

Incidentally, the “diameter (or cross-sectional area) of the valve body” referred to in this specification refers to a portion of the valve body 51 that is in contact with the valve seat 69 when the valve body 51 is seated on the valve seat 69. It should be understood to refer to the diameter (or cross-sectional area).

In order to further improve the assemblability of the movable component to the valve housing 60 and the like, tapered surfaces (inclined surfaces) may be formed on each part as shown in FIG. For example, a tapered surface 81 is formed at a step between the valve body 51 and the rod 52 of the operating body 54, and a step between the high-pressure correction chamber 62 of the valve housing 60 and the rod insertion hole 64 is formed. A tapered surface 82 is formed. These tapered surfaces 8
By providing 1 and 82, it becomes easy to insert the valve body 51 and the rod 52 into the rod insertion hole 64. Further, a tapered surface 83 is formed around the lower end of the high-pressure correction unit 53, and the pressure-sensitive chamber 63 of the valve housing 60 and the high-pressure correction unit insertion hole 6 are formed.
A tapered surface 84 is formed at the step between the steps 5 and 5. The provision of the tapered surfaces 83 and 84 makes it easy to insert the high-pressure correction unit 53 into the high-pressure correction unit insertion hole 65. Further, as shown in FIG. 7, the upper end portion (base end portion) 52a of the rod portion 52 is formed to have a larger diameter than the high-pressure correction portion 53 and
May be formed as a mortar-shaped tapered surface 85. In this case, the rod portion 52 can be easily inserted from the upper end side of the high-pressure correction portion 53, and the two can be easily fitted. The large-diameter rod portion upper end portion 52a facilitates attachment of the operating body 54 to the diaphragm 57 similarly to the upper end portion 53a of the high-pressure correction portion.

In the embodiment shown in FIG. 2, the rod portion 51 of the operating body 54 and the high-pressure correction portion 52 are closely connected to each other.
As shown in FIG. 7, a slight gap 86 may be provided between the rod portion 51 and the high-pressure correction portion 52, and a ring seal 87 for sealing the gap may be provided. Some gap 8
6 allows the rod portion 51 and the high-pressure correction portion 52 to make a small relative displacement in the radial direction, and the rod portion insertion hole 64 and the high-pressure correction portion insertion hole 65 due to a processing error in manufacturing the valve housing. It is possible to compensate for a slight shift of the axial center position. For this reason, the necessity of setting the positional relationship between the axes of the various spaces and holes formed in the valve housing 60 with high accuracy is reduced. The ring seal 87 is for preventing the leakage of the high-pressure gas from the high-pressure correction chamber 62 to the pressure-sensitive chamber 63, but is formed of an elastic material such as rubber to allow radial displacement of the member. Preferably.

In the control valve of FIGS. 2 and 4, a seal member may be provided at a sliding contact portion between the inner peripheral surface of the rod insertion hole 64 and the outer peripheral surface of the rod 52. Further, a seal member may be provided in a sliding contact portion between the inner peripheral surface of the high-pressure correction unit insertion hole 65 and the outer peripheral surface of the high-pressure correction unit 53.

In the control valves of FIGS. 2 and 4, the diaphragm 57 is used as the pressure-sensitive body constituting the pressure-sensitive displacement mechanism, but a bellows may be used instead. The above embodiment and other examples relate to the control valve of the internal control system.
The present invention may be applied to a set pressure variable valve capable of changing et. For example, an electromagnetic solenoid that can be operatively connected to a pressure-sensitive body is provided in the form of a pressure-sensitive displacement mechanism including a pressure-sensitive body, and the suction pressure P directly or indirectly detected by a pressure sensor or the like.
The set suction pressure Pset may be appropriately changed by adjusting the electromagnetic biasing force of the electromagnetic solenoid unit under the control of the control computer based on s.

In the above embodiment and another example, the operating member 5
The case where the cross-sectional shape of each part of FIG. 4 and the cross-sectional shape of the space for the inner chamber and the insertion hole of the valve housing 60 is circular is described, but these cross-sectional shapes may be irregular cross-sections other than the circular cross-section. In the case of such a modified cross section, a large diameter means a large cross-sectional area.

The term "swash plate type compressor" as used in this specification means all types of compressors in which a piston is reciprocated by an inclined cam plate. (Points of the technical idea other than the claims): (A) In the control valve of the variable displacement swash plate type compressor according to any one of claims 1 to 6, the pressure-sensitive displacement mechanism includes:
A pressure sensitive body consisting of a diaphragm or bellows that is displaced in response to a change in suction pressure.

(B) In the control valve of the variable displacement type swash plate type compressor according to any one of claims 1 to 6, the valve seat and the valve body are provided in a valve housing of the control valve. A valve chamber to be present, a high-pressure correction chamber that exposes a pressure-receiving surface of the high-pressure correction unit, and a pressure-sensitive chamber that houses at least a part of the pressure-sensitive displacement mechanism are partitioned and arranged in this order, and the valve chamber and the high-pressure correction chamber are arranged in this order. A rod part insertion hole having an inner diameter corresponding to the diameter of the rod part is formed in a partition wall between the high pressure correction chamber and the pressure sensitive chamber, and the partition wall between the high pressure correction chamber and the pressure sensitive chamber corresponds to the diameter of the high pressure correction unit. A high-pressure correction section insertion hole with an inner diameter is formed. According to this configuration, in the valve housing, the pressure-sensitive chamber, the high-pressure correction section insertion hole, the high-pressure correction chamber, the rod insertion hole, and the valve chamber are arranged in this order while gradually reducing the diameter. Therefore, it is possible to assemble the control valve by inserting the valve body, the rod, and the high-pressure correction unit into the valve housing in one direction from the pressure-sensitive chamber to the valve chamber. Assembly becomes easier than before.

[0052]

As described in detail above, according to the control valve described in each claim, the structure of the control valve can be simplified as compared with the conventional one while the high-pressure correction structure is employed, and the assembly procedure is simplified. The assembly itself becomes easier due to the reduction in the number of assembly steps and the number of assembly steps.

[Brief description of the drawings]

FIG. 1 is a sectional view of a variable displacement swash plate type compressor.

FIG. 2 is a cross-sectional view of a displacement control valve according to one embodiment.

FIG. 3 is a schematic sectional view showing one step of an assembly procedure of the capacity control valve.

FIG. 4 is a sectional view corresponding to FIG. 2 showing another example of the capacity control valve.

FIG. 5 is a partial sectional view showing another example of the valve body of the displacement control valve.

FIG. 6 is a partial cross-sectional view showing another example of the valve body of the displacement control valve.

FIG. 7 is a sectional view corresponding to FIG. 3, showing another example of the capacity control valve.

FIG. 8 is a partial sectional view showing another example of the capacity control valve.

[Explanation of symbols]

5 ... Crank chamber, 12 ... Swash plate, 21 ... Suction chamber (suction pressure area), 22 ... Discharge chamber (discharge pressure area), 27A, 27B ...
Bleed passage, 50 ... Volume control valve, 51 ... Valve part, 52 ... Rod part, 53 ... High pressure correction part, 53b ... Pressure receiving surface, 54 ... Working body, 57 ... Diaphragm (pressure sensitive body), 60 ... First valve Housing, 61: space for first inner chamber (valve chamber), 62 ...
Second inner chamber space (high-pressure correction chamber), 63: third inner chamber space (pressure-sensitive chamber), 64: rod portion insertion hole, 65: high-pressure correction portion insertion hole, 69: annular step portion (valve seat) , 70: second valve housing, 71: adjusting body, 72: setting spring, 73: spring receiver, 74: ball, 75: ball receiver (57, 7)
1, 72, 73, 74 and 75 constitute a pressure-sensitive displacement mechanism), d1, d2: diameter, Pc: crank pressure, Pd: discharge pressure, Ps: suction pressure.

Continued on the front page (72) Inventor Hirotaka Kurakake 2-1-1, Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Ryo Matsubara 2-1-1, Toyota-cho, Kariya-shi, Aichi Prefecture Toyota Corporation Inside the automatic loom mill (72) Inventor Masaki Ota 2-1-1 Toyota-cho, Kariya-shi, Aichi F-term inside the Toyota Industries Corporation (reference) 3H045 AA04 AA10 AA13 AA27 BA19 CA01 CA02 CA03 DA25 EA33 3H076 AA06 BB40 BB41 CC12 CC20 CC27 CC41 CC85 CC92 CC93

Claims (6)

[Claims] 1. A variable displacement type swash plate type compressor, which is disposed in a bleed passage connecting a crank chamber and a suction pressure region, and controls a discharge amount of the compressor by controlling a gas discharge amount from the crank chamber. A control valve for guiding a suction pressure to a set suction pressure, comprising: a valve seat provided in the bleed passage; a pressure-sensitive displacement that determines a set suction pressure of the control valve and that is displaced in response to a change in the suction pressure. A valve body that is provided in the valve seat so as to be able to contact and separate from the valve seat and that can adjust an opening degree of the bleed passage; a rod unit that transmits displacement of the pressure-sensitive displacement mechanism to the valve body; To the pressure-sensitive displacement mechanism to correct the set suction pressure. The valve body and the rod are integrated, and the cross-sectional area of the valve is The high-pressure compensator is set so as not to exceed the cross-sectional area, and A control valve for a variable displacement type swash plate compressor, characterized in that the control valve is provided with a pressure receiving surface for discharge pressure by being provided as a portion having a diameter larger than the diameter of the rod portion around the periphery of the swash plate. 2. The cross-sectional area of the valve body does not exceed the cross-sectional area of the rod by making the diameter of the valve body equal to or smaller than the diameter of the rod. The control valve for a variable displacement swash plate type compressor according to claim 1. 3. The rod portion is disposed so as to be movable between the valve seat and the pressure-sensitive displacement mechanism in a displacement direction of the pressure-sensitive displacement mechanism, and the valve body is disposed on a valve seat side of the rod portion. The control valve for a variable displacement swash plate type compressor according to claim 1, wherein the control valve is provided at an end of the swash plate type compressor, wherein the high pressure correction unit is provided at an end of the rod unit on a pressure-sensitive displacement mechanism side. . 4. The high-pressure compensator is formed of a separate member from the valve body and the rod and the high-pressure compensator, and the high-pressure compensator is externally fitted to the rod. 4. The control valve of the variable displacement swash plate type compressor according to any one of 3. 5. The variable capacity according to claim 1, wherein the valve body, the rod, and the high-pressure correction unit are formed of one member. Control valve for swash plate type compressor. 6. The control valve for a variable displacement swash plate type compressor according to claim 1, wherein the valve body has a needle shape.