valve

Abstract

Provided is a valve that can be closed with a small amount of driving force.　This valve V1 comprises: a valve housing 10 in which a primary pressure port 41a and a secondary pressure port 11 are formed; a valve body 51 driven by a solenoid 80; a valve seat on which the valve body 51 is seated; and a spring 85 that urges the valve body in a valve opening direction, wherein the valve seat includes a first valve seat 10a and a second valve seat 40a which is disposed on an inner diameter side of the first valve seat 10a and moves in a direction in which the second valve seat approaches the valve body 51 due to a differential pressure between a primary pressure and a secondary pressure.

Description

[Technical field]

[0001] The present invention relates to a valve for variably controlling a working fluid, and more particularly to a displacement control valve for controlling the discharge volume of a variable displacement compressor used in an automotive air conditioning system in accordance with pressure. [Background technology]

[0002] A variable displacement compressor used in air conditioning systems for automobiles and the like includes a rotating shaft, a swash plate, and pistons for compression. The rotating shaft is driven to rotate by an engine, the swash plate is connected to the rotating shaft with a variable inclination angle, and the pistons are connected to the swash plate. A variable displacement compressor controls the discharge amount of fluid by changing the inclination angle of the swash plate to change the stroke amount of the piston. The inclination angle of the swash plate can be continuously changed by appropriately controlling the pressure in the control chamber using the suction pressure Ps of the suction chamber that draws in the fluid, the discharge pressure Pd of the discharge chamber that discharges the fluid pressurized by the piston, and the control pressure Pc of the control chamber that houses the swash plate, using a capacity control valve that is opened and closed by electromagnetic force.

[0003] When the variable displacement compressor is continuously operated, the control computer controls the supply of electricity to the displacement control valve, and the solenoid generates an electromagnetic force to move the valve body in the axial direction. This opens and closes the valve provided between the discharge port through which the discharge fluid with discharge pressure Pd passes and the control port through which the control fluid with control pressure Pc passes, thereby performing normal control to adjust the control pressure Pc in the control chamber of the variable displacement compressor.

[0004] During normal control of the capacity control valve, the pressure in the control chamber in the capacity control compressor is appropriately controlled, and the inclination angle of the swash plate relative to the rotating shaft is continuously changed to change the stroke amount of the piston and control the amount of fluid discharged into the discharge chamber, thereby adjusting the air conditioning system to achieve the target cooling capacity.

[0005] Also, some displacement control valves control the flow rate of fluid flowing from a control port to a suction port by opening and closing a poppet valve provided between the control port and the suction port (see Patent Document 1). Such displacement control valves control the control pressure Pc in a control chamber of a variable displacement compressor by utilizing the pressure difference between a primary control pressure Pc and a secondary suction pressure Ps that is lower than the control pressure Pc. The control chamber of the variable displacement compressor is connected to the discharge chamber of the variable displacement compressor via an orifice, and the control pressure Pc is adjusted by constantly supplying a high discharge pressure Pd to the control chamber through the orifice. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2015-075054 A (pages 8 to 10, Figure 2) Summary of the Invention [Problem to be solved by the invention]

[0007] In a displacement control valve such as that described in Patent Document 1, which has a poppet valve structure, when the valve opening becomes narrower during closing, the force acting on the valve body from the fluid in the flow path in the opposite direction to the driving force of the solenoid increases. In particular, when the fluid pressure is high, the force that the fluid exerts on the valve body is strong, and the solenoid is required to have a driving force that can withstand this condition.

[0008] The present invention has been made in consideration of such problems, and has an object to provide a valve that can be closed with a small driving force. [Means for solving the problem]

[0009] In order to solve the above problems, the valve of the present invention comprises: a valve housing having a primary pressure port and a secondary pressure port formed therein; A valve body driven by a drive source; a valve seat on which the valve body is seated; A valve comprising: The valve seat includes a first valve seat and a second valve seat that is disposed on an inner diameter side of the first valve seat and moves in a direction approaching the valve body due to a pressure difference between a primary pressure and a secondary pressure. According to this, the second valve seat is moved closer to the valve disc by the pressure difference between the primary and secondary pressures, thereby making it possible to reduce the valve diameter when the valve is closed. This reduces the resistance force that the valve disc receives from the primary pressure, allowing the valve to be closed with a small driving force.

[0010] The movable body on which the second valve seat is formed may have a pressure-receiving surface that is constantly subjected to a secondary pressure. According to this, the differential pressure can be constantly applied to the movable body, thereby improving the responsiveness to the differential pressure.

[0011] The movable body may be biased in a direction away from the valve body by a biasing means. According to this, when the pressure difference acting on the movable body is small, the movable body can be reliably separated from the valve body.

[0012] A fluid under a primary pressure and a fluid under a secondary pressure may be able to flow through a space facing the pressure-receiving surface. According to this, the primary pressure is also supplied to the space facing the pressure-receiving surface that receives the secondary pressure, so that the differential pressure acting on the movable body can be adjusted according to the primary pressure, thereby improving the responsiveness of the movable body.

[0013] The biasing means may be disposed in the space. According to this, the movable body and the valve body can be operated independently, and the responsiveness of the movable body can be improved.

[0014] The movable body may have a closing portion that closes a second primary pressure port through which a fluid at a primary pressure can flow in the space when the valve is closed with the valve body seated on the second valve seat. This makes it possible to prevent fluid leakage from the primary pressure side to the secondary pressure side when the valve is closed.

[0015] The second primary pressure port may be a convergent nozzle whose flow passage cross-sectional area decreases toward the downstream side. According to this, when the fluid passing through the second primary pressure port is a subsonic flow, the flow velocity of the fluid passing through the second primary pressure port from the primary pressure side increases and the pressure of the fluid supplied to the space decreases, so that the differential pressure acting on the movable body is adjusted to be large. This makes it easier to bring the movable body close to the valve body.

[0016] The second primary pressure port may be a divergent nozzle whose flow passage cross-sectional area increases toward the downstream side. According to this, when the fluid passing through the second primary pressure port is a supersonic flow, the flow velocity of the fluid passing through the second primary pressure port from the primary pressure side increases and the pressure of the fluid supplied to the space decreases, so that the pressure difference acting on the movable body is adjusted to be large. This makes it easier to bring the movable body close to the valve body. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a cross-sectional view showing a state in which a CS valve is opened in a non-energized state of the capacity control valve according to the first embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of FIG. [Diagram 3] 3 is an enlarged cross-sectional view showing a state in which the CS valve is closed with the CS valve body seated on the first valve seat in the capacity control valve of the first embodiment in an energized state (maximum energization). FIG. [Figure 4] 1 is an enlarged cross-sectional view showing a state in which the CS valve is closed when the CS valve element is seated on the second valve seat of the movable body that has been moved by a differential pressure in the capacity control valve of the first embodiment in an energized state. FIG. [Diagram 5] 5 is an enlarged cross-sectional view showing a state in which the CS valve disc has moved further from the state shown in FIG. 4 and is seated on the first valve seat, thereby closing the CS valve, in the capacity control valve of the first embodiment in an energized state. FIG. [Figure 6] FIG. 11 is a cross-sectional view showing a state in which a CS valve is opened in a non-energized state of a capacity control valve according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A valve according to the present invention will be described below with reference to the following examples. Note that although the embodiments will be described using a displacement control valve as an example, the valve can also be used for other purposes. EXAMPLES

[0019] A displacement control valve according to a first embodiment will be described with reference to Fig. 1 to Fig. 5. In the following description, the left and right sides as viewed from the front side of Fig. 1 will be referred to as the left and right sides of the displacement control valve. In particular, the left side of the drawing where the valve housing 10 is arranged will be referred to as the left side of the displacement control valve, and the right side of the drawing where the solenoid 80, which is the drive source, is arranged will be referred to as the right side of the displacement control valve.

[0020] The capacity control valve of the present invention is incorporated in a variable capacity compressor (not shown) used in the air conditioning system of an automobile or the like, and controls the discharge volume of the variable capacity compressor by variably controlling the pressure of a working fluid (hereinafter simply referred to as "fluid") which is a refrigerant, thereby adjusting the air conditioning system to achieve a target cooling capacity.

[0021] First, the variable displacement compressor will be described. The variable displacement compressor has a casing that includes a discharge chamber, a suction chamber, a control chamber, and multiple cylinders. The variable displacement compressor is provided with a communication passage that directly connects the discharge chamber and the control chamber, and this communication passage is provided with a fixed orifice 9 for balancing the pressures of the discharge chamber and the control chamber (see FIG. 1).

[0022] The variable displacement compressor includes a rotating shaft, a swash plate, and a plurality of pistons. The rotating shaft is driven to rotate by an engine (not shown) installed outside the casing. The swash plate is connected to the rotating shaft in a control chamber so as to be tiltable by a hinge mechanism. The pistons are connected to the swash plate and fitted in their respective cylinders so as to be capable of reciprocating motion. The variable displacement compressor uses a displacement control valve V1, which is driven to open and close by an electromagnetic force, to utilize the suction pressure Ps of the suction chamber that draws in the fluid, the discharge pressure Pd of the discharge chamber that discharges the fluid pressurized by the pistons, and the control pressure Pc of the control chamber that houses the swash plate, and by appropriately controlling the pressure in the control chamber, the inclination angle of the swash plate is continuously changed to change the stroke amount of the pistons, thereby controlling the discharge amount of the fluid.

[0023] 1, the capacity control valve V1 of the first embodiment incorporated in a variable capacity compressor variably controls the control pressure Pc in the control chamber by adjusting the current flowing through the coil 86 constituting the solenoid 80 and controlling the opening and closing of the CS valve 50 in the capacity control valve V1 to control the fluid flowing from the control chamber, which is the primary pressure side, to the suction chamber, which is the secondary pressure side. Note that the discharge fluid at the discharge pressure Pd of the discharge chamber is constantly supplied to the control chamber via the fixed orifice 9, and the control pressure Pc in the control chamber can be increased by closing the CS valve 50 in the capacity control valve V1.

[0024] In the capacity control valve V1 of the first embodiment, the CS valve 50 has a poppet valve structure composed of a CS valve body 51 as a valve body, a first valve seat 10a, and a second valve seat 40a. The first valve seat 10a is formed in an annular convex portion 10b protruding from the inner peripheral surface of the valve housing 10 to the inner diameter side. The second valve seat 40a is formed at the axial right end of the movable body 40 that moves in the axial direction due to a pressure difference on the inner diameter side of the first valve seat 10a. The CS valve 50 opens and closes when an abutment portion 51a formed at the axial left end of the CS valve body 51 comes into contact with or separates from the first valve seat 10a or the second valve seat 40a in the axial direction. The first valve seat 10a and the second valve seat 40a are valve seats of the present invention.

[0025] Next, the structure of the displacement control valve V1 will be described. As shown in Fig. 1, the displacement control valve V1 is mainly composed of a valve housing 10, a CS valve element 51, a movable body 40, and a solenoid 80. The valve housing 10 is made of a metal material. The CS valve element 51 and the movable body 40 are each arranged in the valve housing 10 so as to be able to reciprocate in the axial direction. The solenoid 80 is connected to the valve housing 10 and applies a driving force to the CS valve element 51.

[0026] 1, the CS valve body 51 is made of a metal material or a resin material. The CS valve body 51 is composed of a large diameter portion 51b that is a columnar body with a constant cross section, and a small diameter portion 51c that extends axially rightward from the inner diameter side of the axial right end of the large diameter portion 51b, and also serves as a rod that is disposed to pass through the coil 86 of the solenoid 80.

[0027] An abutment portion 51a is formed on the axial left end face of the CS valve body 51, i.e., the axial left end face of the large diameter portion 51b. The abutment portion 51a bulges toward the first valve seat 10a and the second valve seat 40a and is formed to have a curved cross-sectional shape. More specifically, the curved shape of the abutment portion 51a is formed by a part of a sphere having a constant radius of curvature. Note that, as long as the abutment portion 51a has a shape that allows it to seat on the first valve seat 10a and the second valve seat 40a, it does not have to be formed by a part of a sphere having a constant radius of curvature, and it does not have to be a curved surface.

[0028] As shown in FIG. 1, the solenoid 80 is mainly composed of a casing 81, a center post 82, the CS valve body 51, a movable iron core 84, a coil spring 85 as a spring, and an exciting coil 86. The casing 81 has an opening 81a that opens to the left in the axial direction. The center post 82 is substantially cylindrical, inserted into the opening 81a of the casing 81 from the left in the axial direction, and disposed between the inner diameter side of the casing 81 and the inner diameter side of the valve housing 10. The CS valve body 51 is inserted into the center post 82 and is capable of reciprocating in the axial direction, and its left axial end is disposed in the valve housing 10. The movable iron core 84 is adapted to have the right axial end of the CS valve body 51 inserted therein and fixed thereto. The coil spring 85 is disposed between the center post 82 and the movable iron core 84, and biases the movable iron core 84 to the right in the axial direction, which is the valve opening direction of the CS valve 50. The coil spring 85 is wound around the outside of the center post 82 via a bobbin.

[0029] As shown in Fig. 1, the valve housing 10 is formed with an annular protrusion 10b that protrudes from the inner peripheral surface to the inner diameter side at approximately the center in the axial direction. The annular protrusion 10b is formed with a first valve seat 10a having an inclined cross section. The first valve seat 10a is continuous from the annular side surface on the axial right side to the inner diameter side, and gradually reduces in diameter to the axial left. In other words, the first valve seat 10a is formed with a tapered surface in which a cross-sectionally linear inclined surface extends in the circumferential direction.

[0030] The valve housing 10 is also formed with a Ps port 11 as a secondary pressure port. The Ps port 11 penetrates radially to the right of the annular protrusion 10b in the axial direction and communicates with the suction chamber of the variable displacement compressor. The valve housing 10 is also formed with a second Pc port 12 as a second primary pressure port. The second Pc port 12 penetrates radially to the left of the annular protrusion 10b in the axial direction and communicates with the control chamber of the variable displacement compressor. The second Pc port 12 has a tapered nozzle shape in which the flow path cross-sectional area decreases toward the downstream side (dA<0).

[0031] A recess 10c is formed on the axial left side of the valve housing 10. A flanged cylindrical movable body 40 is inserted into the recess 10c from the axial left side. At the axial left end of the valve housing 10, a stopper 41 having a rectangular cross section is press-fitted and fixed to an annular step 10d formed on the axial left edge of the recess 10c, and a through hole 41a passing through the stopper 41 in the axial direction forms a first Pc port as a primary pressure port communicating with the control chamber of the variable displacement compressor.

[0032] A valve chamber 20 is formed inside the valve housing 10, axially to the right of the annular protrusion 10b. A contact portion 51a of a CS valve element 51 is arranged in the valve chamber 20 so as to be able to reciprocate axially. The Ps port 11 extends radially inward from the outer circumferential surface of the valve housing 10 and communicates with the valve chamber 20.

[0033] Moreover, an annular space 30 is formed inside the valve housing 10 by inserting the movable body 40 into a recess 10c that is formed axially to the left of the annular protrusion 10b. The second Pc port 12 extends radially inward from the outer circumferential surface of the valve housing 10 and communicates with the space 30.

[0034] Here, the movable body 40 will be described. As shown in Fig. 2, the movable body 40 is composed of a base portion 40c, a flange portion 40d, and an extension portion 40e as a blocking portion, and is formed into a flanged double cylinder shape. The base portion 40c is formed into a cylindrical shape with a through hole 40b penetrating in the axial direction. The flange portion 40d extends from the outer peripheral surface of the axial left end portion of the base portion 40c toward the outer diameter side and is formed into an annular plate shape. The extension portion 40e extends from the outer diameter portion of the flange portion 40d to the axial right and is formed into a cylindrical shape.

[0035] The base 40c is inserted into the inner diameter side of the annular protrusion 10b of the valve housing 10, and its outer peripheral surface is slidable against the inner peripheral surface of the annular protrusion 10b. A second valve seat 40a having an inclined cross section is formed at the right end of the base 40c in the axial direction. The second valve seat 40a has an annular flat surface 40f from the outer diameter side to the inner diameter side, and the flat surface 40f is connected to the inner diameter side, and the diameter of the second valve seat 40a gradually decreases toward the left in the axial direction. In other words, the second valve seat 40a is formed by a tapered surface in which a cross-sectionally linear inclined surface extends in the circumferential direction.

[0036] The outer peripheral surfaces of the flange portion 40d and the extension portion 40e are slidable against the inner peripheral surface of the recess 10c of the valve housing 10. The outer peripheral surfaces of the flange portion 40d and the extension portion 40e are slightly spaced apart from the inner peripheral surface of the recess 10c, and the outer peripheral surface of the base portion 40c is slightly spaced apart from the inner peripheral surface of the annular protrusion 10b in the radial direction to form minute gaps. As such, the minute gaps are formed, so that the movable body 40 can move smoothly relative to the valve housing 10 in the axial direction. The outer peripheral surfaces of the flange portion 40d and the extension portion 40e are sealed against the inner peripheral surface of the recess 10c by a clearance seal.

[0037] The movable body 40 is biased in a direction away from the CS valve body 51, i.e., to the axial left, by a coil spring 42 serving as a biasing means disposed in the space 30. More specifically, the coil spring 42 is fitted inside the movable body 40 along the extension portion 40e, and its right axial end abuts against the bottom surface of the recess 10c, i.e., the axial left side surface of the annular protrusion 10b. The left axial end of the coil spring 42 abuts against an inner surface 40h on the axial right side of the flange portion 40d of the movable body 40. The coil spring 42 is a compression spring.

[0038] In the movable body 40, an inner surface 40h on the axial right side of the flange portion 40d facing the space 30 and an axial right end surface 40g of the extension portion 40e form pressure-receiving surfaces that constantly receive the secondary pressure.

[0039] The movable body 40 is biased axially leftward by the biasing force of the coil spring 42. The axial left end face 40k of the movable body 40 abuts against the axial right side face of the stopper 41, thereby restricting the movement of the movable body 40 axially leftward (see Figs. 2 and 3). At this time, the axial right end face of the base 40c is disposed on the inner diameter side of the annular protrusion 10b.

[0040] In this way, inside the valve housing 10, a first Pc-Ps flow path (see solid arrow in Figure 2) is formed by the through hole 41a of the stopper 41, the through hole 40b of the movable body 40, the valve chamber 20, and the Ps port 11, which connects the control chamber and the suction chamber of the variable displacement compressor.

[0041] In addition, a communication passage 10e is formed by an axially extending groove on the inner peripheral surface of the annular protrusion 10b of the valve housing 10. The communication passage 10e also provides communication between the space 30 and the valve chamber 20. That is, the space 30 is capable of receiving a primary pressure fluid through the second Pc port 12, and a secondary pressure fluid is capable of receiving a secondary pressure fluid through the communication passage 10e. As a result, a second Pc-Ps flow passage (see solid arrow in FIG. 2) is formed inside the valve housing 10 by the second Pc port 12, the space 30, the communication passage 10e, the valve chamber 20, and the Ps port 11, which communicates between the control chamber and the suction chamber of the variable displacement compressor.

[0042] In this embodiment, the second Pc port 12 is formed in a tapered nozzle shape in which the cross-sectional area of ​​the flow path decreases toward the downstream side (dA<0). The cross-sectional area of ​​the flow path of the second Pc port 12 decreases continuously toward the downstream side.

[0043] Here, we will explain the change in flow velocity and pressure of the fluid passing through the second Pc port 12. Regarding the effect of area change in an isentropic flow, the relational equation between cross-sectional area and pressure is shown below.

[0044]

number

[0045] p: pressure γ: specific heat ratio M: Mach number A: Area

[0046] Based on this relational expression between cross-sectional area and pressure, when the fluid passing through the second Pc port 12 is a subsonic flow (M<1), the flow velocity of the fluid passing through the second Pc port 12 increases. Also, the pressure of the fluid decreases. Therefore, the pressure Pc' of the fluid in the space 30 flowing in from the second Pc port 12 becomes smaller than the control pressure Pc of the control fluid in the through hole 41a of the stopper 41 (Pc' <Pc)。

[0047] Next, we will explain the opening and closing mechanism of the CS valve 50. As shown in Figure 2, when the capacity control valve V1 is in a non-energized state, the CS valve body 51 is pressed axially rightward by the biasing force of the coil spring 85 (see Figure 1), and the CS valve 50 is fully open.

[0048] As shown in FIG. 3, when the capacity control valve V1 is in an energized state (maximum energized state), the driving force of the solenoid 80 causes the CS valve body 51 to move axially leftward by the biasing force of the coil spring 85 (see FIG. 1), and the abutment portion 51a of the CS valve body 51 seats on the first valve seat 10a, thereby closing the CS valve 50.

[0049] 2 and 3, when the difference between the primary pressure and the secondary pressure acting on the movable body 40 in the axial direction is small, the movable body 40 receives a biasing force (indicated by a white arrow in FIGS. 2 and 3) from the coil spring 42 in a direction away from the CS valve body 51, and moves to the axial left. The movement of the movable body 40 is restricted by the abutment of the axial left end face 40k against the stopper 41. In detail, the primary pressure is mainly acting on the axial left end face 40k of the movable body 40, and a pressure between the primary pressure and the secondary pressure is mainly acting on the inner surface 40h on the axial right side of the flange portion 40d, the axial right end face 40g of the extension portion 40e, and the second valve seat 40a and the flat surface 40f at the axial right end of the base portion 40c. At this time, the axial right end face 40g of the extension portion 40e of the movable body 40 is disposed axially to the left of the opening of the second Pc port 12 on the space 30 side, so that the second Pc port 12 is fully opened.

[0050] On the other hand, when the pressure difference acting on the movable body 40 in the axial direction is large (for example, when the primary pressure is high), and the force acting on the movable body 40 due to the pressure difference exceeds the biasing force of the coil spring 42, the coil spring 42 is compressed. Also, the movable body 40 moves axially rightward, which is a direction approaching the CS valve body 51, and the axial right end face 40g of the extension part 40e abuts against the bottom face of the recess 10c of the valve housing 10, restricting the movement (see FIG. 4). At this time, the second Pc port 12 is closed by a sealing part formed by a clearance seal between the outer peripheral surface at the axial right end part of the extension part 40e of the movable body 40 and the inner peripheral surface of the recess 10c.

[0051] In this way, the movable body 40 moves in the axial direction due to the balance between the differential pressure acting on the movable body 40 in the axial direction and the biasing force of the coil spring 42. In other words, the movable body 40 operates independently of the CS valve body 51 which moves due to the driving force of the solenoid 80.

[0052] 4, in a state in which the axial right end face 40g of the extension part 40e of the movable body 40 abuts against the bottom surface of the recessed part 10c of the valve housing 10, the flat surface 40f at the axial right end of the base part 40c is disposed at an axial position on the inner diameter side of the first valve seat 10a so as to be substantially flush in the radial direction with the axial right side surface of the annular protruding part 10b. As a result, when the capacity control valve V1 is closed in an energized state, the abutment part 51a of the CS valve element 51 can seat on the second valve seat 40a with a stroke shorter than the stroke (see FIG. 3) required for seating on the first valve seat 10a, thereby closing the CS valve 50.

[0053] Furthermore, since the second valve seat 40a is disposed on the inner diameter side relative to the first valve seat 10a and is formed with a smaller diameter, the pressure receiving area A2 (see FIG. 4) when the abutting portion 51a of the CS valve body 51 is seated on the second valve seat 40a can be made smaller (A1>A2) than the pressure receiving area A1 (see FIG. 5) when the abutting portion 51a of the CS valve body 51 is seated on the first valve seat 10a. That is, the second valve seat 40a has a small valve opening diameter, and receives a smaller resistance from the primary pressure in the through hole 40b of the movable body 40 acting axially rightward on the abutting portion 51a of the CS valve body 51, and the CS valve 50 can be closed with a small driving force of the solenoid 80.

[0054] 4, the CS valve element 51 is further moved axially leftward until the abutting portion 51a of the CS valve element 51 seats on the first valve seat 10a, and the resistance that the CS valve element 51 receives from the primary pressure in the through hole 40b of the movable body 40 is based on the small pressure-receiving area A2 described above, so that it is possible to reduce the driving force of the solenoid 80 required to close the CS valve 50. Note that in the state shown in Fig. 5, the abutting portion 51a of the CS valve element 51 seats on the first valve seat 10a, so that the CS valve 50 can be kept closed even if the movable body 40 moves axially leftward due to a change in the differential pressure acting on the movable body 40 in the axial direction.

[0055] At this time, as the CS valve body 51 moves, the movable body 40 is pressed axially to the left, and the axial right end face 40g of the extension portion 40e moves axially left away from the bottom surface of the recess 10c of the valve housing 10. However, since the axial right end face 40g of the extension portion 40e is positioned axially to the right of the opening of the second Pc port 12 on the space 30 side, the second Pc port 12 is maintained in a blocked state, and fluid leakage is prevented.

[0056] In addition, the movable body 40 has an inner surface 40h on the axial right side of the flange portion 40d facing the space 30 and an axial right end face 40g of the extension portion 40e which are pressure-receiving surfaces that always receive the secondary pressure. Therefore, the differential pressure between the primary pressure and the secondary pressure can always be applied to the movable body 40, thereby improving responsiveness to the differential pressure.

[0057] In addition, since the movable body 40 is biased in a direction away from the CS valve body 51 by the coil spring 42, when the differential pressure acting on the movable body 40 is small, the movable body 40 can be reliably moved away from the CS valve body 51.

[0058] Furthermore, since the space 30 is capable of communicating with a primary pressure fluid and a secondary pressure fluid, the space 30 is supplied with the primary pressure through the second Pc port 12 in addition to the secondary pressure supplied from the valve chamber 20 on the secondary pressure side through the communication passage 10e. Therefore, the differential pressure acting on the movable body 40 can be adjusted according to the primary pressure, and the responsiveness of the movable body 40 can be improved.

[0059] Furthermore, by forming a communication passage 10e between the space 30 and the valve chamber 20, fluid can be transferred from within the space 30 to the valve chamber 20 through the communication passage 10e when the movable body 40 moves axially to the right, allowing the movable body 40 to move smoothly.

[0060] In addition, the second Pc port 12 is a convergent nozzle whose flow path cross-sectional area decreases toward the downstream side, and when the fluid passing through the second Pc port 12 is a subsonic flow, the flow velocity of the fluid passing through the second Pc port 12 from the primary pressure side increases and the pressure of the fluid supplied to the space 30 decreases, so that the differential pressure acting on the movable body 40 is adjusted to be large. This makes it easier to bring the movable body 40 close to the CS valve body 51.

[0061] Furthermore, the coil spring 42 is disposed in the space 30, and the movable body 40 and the CS valve body 51 can be operated independently, thereby improving the responsiveness of the movable body 40.

[0062] Also, as shown in Figure 2, in the non-energized state, when the differential pressure is small, the CS valve 50 and the second Pc port 12 can both be fully opened, thereby increasing the flow rate of fluid through both the first Pc-Ps flow path and the second Pc-Ps flow path.

[0063] Furthermore, the displacement control valve V1 is constructed so that the movable body 40 and the coil spring 42 are inserted into the recess 10c from the axial left end of the valve housing 10, and then the stopper 41 is press-fitted and fixed, making assembly easy. EXAMPLES

[0064] A displacement control valve according to a second embodiment will be described with reference to Fig. 6. Note that a description of the same configuration as in the first embodiment will be omitted.

[0065] 6, in the displacement control valve V2 of the second embodiment, a Pc port 112 serving as a second primary pressure port is formed in a valve housing 110. The Pc port 112 has a divergent nozzle shape in which the flow passage cross-sectional area increases toward the downstream side (dA>0).

[0066] Based on the relational expression of cross-sectional area and pressure in the above-mentioned Example 1, when the fluid passing through the Pc port 112 is a supersonic flow (M>1), the velocity of the fluid passing through the Pc port 112 increases and the pressure decreases. Therefore, the pressure Pc' of the fluid in the space 30 flowing in from the Pc port 112 is smaller than the control pressure Pc of the control fluid in the through-hole 41a of the stopper 41 (Pc'<Pc). As a result, the differential pressure acting on the movable body 40 is adjusted to be larger, and the movable body 40 can be easily brought closer to the CS valve body 51.

[0067] As described above, the embodiments of the present invention have been described with reference to the drawings. However, the specific configuration is not limited to these embodiments, and even if there are changes and additions within the scope not departing from the gist of the present invention, they are included in the present invention.

[0068] For example, in the above-mentioned Examples 1 and 2, the aspect in which, in a state where the movable body 40 has moved axially rightward, on the inner diameter side of the first valve seat 10a, the flat surface 40f at the axially right end of the base portion 40c is arranged at an axial position substantially flush with the side surface on the axially right side of the annular convex portion 10b in the radial direction has been described. However, the present invention is not limited to this, and as long as the contact portion 51a of the CS valve body 51 can be seated on the second valve seat 40a before the first valve seat 10a in a state where the movable body 40 has moved axially rightward.

[0069] Also, in the above-mentioned Examples 1 and 2, the aspect in which the second Pc ports 12 and 112 communicating the primary pressure side and the space 30 are formed in a tapered nozzle shape or a flaring nozzle shape in which the cross-sectional area of the flow path continuously increases and decreases has been described. However, the present invention is not limited to this, and the cross-sectional area of the flow path may increase and decrease stepwise. Also, the Pc port communicating the primary pressure side and the space 30 may have a constant cross-sectional area of the flow path.

[0070] Also, the fluid of the primary pressure may not be able to flow through the space 30.

[0071] Also, the communication path 10e is not limited to a groove, and may be formed by a through-hole penetrating the annular convex portion 10b in the axial direction.

[0072] Furthermore, the contact portion 51a of the CS valve body 51 does not have to be formed in a cross-sectionally curved shape, and may be formed, for example, in a stepped shape capable of contacting the first valve seat 10a and the second valve seat 40a, respectively.

[0073] Furthermore, the tapered surfaces constituting the first valve seat 10a and the second valve seat 40a are not limited to being linear, but may be arc-shaped.

[0074] Further, the capacity control valves V1, V2 in the first and second embodiments have been described using the CS valve 50 as an example, but are not limited thereto and may be DC valves that open and close the flow path between the Pd port as the primary pressure port and the Pc port as the secondary pressure port. [Explanation of symbols]

[0075] 9 Fixed Orifice 10 Valve housing 10a First valve seat (valve seat) 10b Annular protrusion 10c Recess 10d stepped section 10e Communication path 11 Ps port (secondary pressure port) 12 2nd Pc port (2nd primary pressure port) 20 Valve chamber 30 space 40 Movable body 40a Second valve seat (valve seat) 40b through hole 40c base 40d flange 40e Extension part (closed part) 40f flat surface 40g Right end face in the axial direction (pressure receiving face that always receives secondary pressure) 40h Side (surface that always receives secondary pressure) 40k Axial left end surface 41 Stopper 41a Through hole (primary pressure port, first Pc port) 42 Coil spring (biasing means) 50 CS valve 51 CS valve body (valve body) 51a Contact part 80 Solenoid 85 Coil spring (spring) 110 Valve housing 112 2nd Pc port (2nd primary pressure port) V1, V2 Capacity control valve (valve)

Claims

1. a valve housing having a primary pressure port and a secondary pressure port formed therein; A valve body driven by a drive source; a valve seat on which the valve body is seated; A valve comprising: the valve seat includes a first valve seat and a second valve seat that is disposed on an inner diameter side of the first valve seat and moves in a direction approaching the valve body due to a pressure difference between a primary pressure and a secondary pressure, A valve in which the movable body on which the second valve seat is formed has a pressure-receiving surface that is constantly subjected to secondary pressure.

2. The valve according to claim 1 , wherein the movable body is biased in a direction away from the valve body by a biasing means.

3. 3. The valve according to claim 2, wherein a fluid at a primary pressure and a fluid at a secondary pressure can flow through a space facing said pressure-receiving surface.

4. 4. The valve of claim 3, wherein the biasing means is disposed in the space.

5. 5. The valve according to claim 3, wherein the movable body has a closing portion that closes a second primary pressure port through which a fluid at a primary pressure can flow into the space when the valve is closed and the valve body is seated on the second valve seat.

6. 6. The valve according to claim 5, wherein the second primary pressure port is a convergent nozzle having a flow passage cross-sectional area that decreases downstream.

7. 6. The valve according to claim 5, wherein the second primary pressure port is a divergent nozzle having a flow passage cross-sectional area that increases downstream.

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