valve

Abstract

The present invention provides a valve capable of closing with a small driving force. The valve (V1) includes: a valve body (10) having a primary pressure port (41a) and a secondary pressure port (11); a valve core (51) driven by a solenoid (80); a valve seat for the valve core (51) to sit on; and a spring (85) that applies force to the valve core (51) in the opening direction, wherein the valve seat includes: a first valve seat (10a); and a second valve seat (40a) disposed on the inner diameter side of the first valve seat (10a) and moved toward the valve core (51) by the pressure difference between the primary pressure and the secondary pressure.

Description

Technical Field

[0001] This invention relates to a valve for variable control of working fluid, for example, to a capacity control valve for controlling the discharge of a variable capacity compressor used in an automotive air conditioning system based on pressure. Background Technology

[0002] Variable capacity compressors used in air conditioning systems of automobiles and other vehicles include a rotating shaft, a swashplate, and a compression piston. The rotating shaft is driven by the engine, the swashplate is connected to the rotating shaft at a variable tilt angle, and the piston is connected to the swashplate. The variable capacity compressor controls the fluid discharge rate by changing the tilt angle of the swashplate, thereby altering the piston stroke. A capacity control valve, driven by electromagnetic force, is used to control the pressure within the control chamber (where the fluid is drawn in, Ps), the discharge pressure within the discharge chamber (where the fluid is pressurized by the piston, Pd), and the control pressure within the control chamber (which houses the swashplate). This allows for continuous change of the swashplate's tilt angle.

[0003] During continuous operation of the variable capacity compressor, the capacity control valve is energized and controlled by the control computer, causing the valve core to move axially via electromagnetic force generated by the solenoid. This enables normal control as follows: the valve located between the discharge port through which the discharge fluid at discharge pressure Pd passes and the control port through which the control fluid at control pressure Pc passes is opened and closed to adjust the control pressure Pc in the control chamber of the variable capacity compressor.

[0004] During normal operation of the capacity control valve, the pressure in the control chamber of the variable capacity compressor is appropriately controlled, and the piston stroke is changed by continuously altering the tilt angle of the swashplate relative to the rotating shaft to control the amount of fluid discharged from the discharge chamber, thereby adjusting the air conditioning system to the target cooling capacity.

[0005] In addition, the capacity control valve can also control the flow rate of fluid flowing from the control port to the suction port by opening and closing a lift valve located between the control port and the suction port (see Patent Document 1). Such a capacity control valve uses the pressure difference between the primary control pressure Pc and the secondary suction pressure Ps, which is lower than the control pressure Pc, to control the control pressure Pc inside the control chamber of the variable capacity compressor. Furthermore, the control chamber of the variable capacity compressor is connected to the discharge chamber of the variable capacity compressor via a throttling orifice, and the high-pressure discharge pressure Pd is continuously supplied to the control chamber through the throttling orifice, thereby adjusting the control pressure Pc.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2015-075054 (pp. 8-10) Figure 2 ) Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] In the capacity control valve as described in Patent Document 1, within the lift valve structure, when the valve is closed, as the valve opening narrows, the force exerted on the valve core by the fluid in the flow path, which is opposite to the driving force of the solenoid, increases. In particular, under higher fluid pressure conditions, the force exerted on the valve core by the fluid is greater, requiring the solenoid to have a driving force corresponding to this condition.

[0011] This invention was made in response to such a problem, and its purpose is to provide a valve that can close with a small driving force.

[0012] Methods for solving problems

[0013] To solve the above-mentioned problems, the valve of the present invention comprises:

[0014] The valve body has a primary pressure port and a secondary pressure port.

[0015] The valve core, which is driven by a drive source; and

[0016] Valve seat, which provides a place for the valve core to sit.

[0017] The valve seat includes: a first valve seat; and a second valve seat disposed on the inner diameter side of the first valve seat, and moving towards the valve core by means of the pressure difference between the primary pressure and the secondary pressure.

[0018] Therefore, due to the pressure difference between the primary and secondary pressures, the second valve seat moves closer to the valve core, thereby reducing the valve orifice diameter when the valve is closed. Consequently, the resistance experienced by the valve core from the primary pressure decreases, allowing the valve to close with a smaller driving force.

[0019] Alternatively, the movable body forming the second valve seat may have a pressure-bearing surface that is always subjected to secondary pressure.

[0020] This ensures that the differential pressure always acts on the movable body, thus improving the responsiveness to differential pressure.

[0021] Alternatively, the movable body may be forced by the force-applying unit in the direction of separation from the valve core.

[0022] Therefore, when the differential pressure acting on the movable body is small, the movable body can be reliably separated from the valve core.

[0023] Alternatively, within the space faced by the pressure-bearing surface, both primary pressure fluid and secondary pressure fluid can flow.

[0024] Thus, the primary pressure is also supplied to the space facing the pressure-bearing surface that bears the secondary pressure, thereby adjusting the differential pressure acting on the movable body according to the primary pressure and improving the responsiveness of the movable body.

[0025] Alternatively, the force-applying unit may be disposed within the space.

[0026] This allows the movable body and the valve core to move independently, thus improving the responsiveness of the movable body.

[0027] Alternatively, the movable body may have a closing part that, when the valve core is seated in the second valve seat, closes the second primary pressure port that allows fluid at the primary pressure to flow within the space.

[0028] This prevents fluid from leaking from the primary pressure side to the secondary pressure side when the valve is closed.

[0029] Alternatively, the second primary pressure port may be a tapered nozzle whose flow path cross-sectional area decreases as it moves downstream.

[0030] Therefore, when the fluid flowing through the second primary pressure port is subsonic, the flow velocity of the fluid flowing from the primary pressure side through the second primary pressure port increases, and the pressure of the fluid supplied to the space decreases, thus increasing the differential pressure acting on the movable body. This allows the movable body to easily access the valve core.

[0031] Alternatively, the second primary pressure port may be a gradually expanding nozzle whose flow path cross-sectional area increases as it moves downstream.

[0032] Therefore, 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, thus increasing the differential pressure acting on the movable body. This allows the movable body to easily access the valve core. Attached Figure Description

[0033] Figure 1 This is a cross-sectional view showing the CS valve open in the unenergized state of the capacity control valve in Embodiment 1 of the present invention;

[0034] Figure 2 yes Figure 1 Enlarged sectional view;

[0035] Figure 3 This is an enlarged cross-sectional view showing the CS valve core sitting on the first valve seat and closing the CS valve when the capacity control valve of Embodiment 1 is energized (at maximum energization).

[0036] Figure 4This is an enlarged cross-sectional view showing the CS valve being closed when the CS valve core is seated on the second valve seat of a movable body that moves by differential pressure in the energized state of the capacity control valve of Embodiment 1.

[0037] Figure 5 This illustrates that in the energized state of the capacity control valve in Example 1, the CS valve core moves from... Figure 4 An enlarged cross-sectional view of the situation where the CS valve core moves further and sits on the first valve seat, thus closing the CS valve;

[0038] Figure 6 This is a cross-sectional view showing the CS valve open in the unenergized state of the capacity control valve in Embodiment 2 of the present invention. Detailed Implementation

[0039] Hereinafter, a method for implementing the valve of the present invention will be described based on an embodiment. Furthermore, although the embodiment uses a capacity control valve as an example, it can also be applied to other applications.

[0040] [Example 1]

[0041] Reference Figures 1 to 5 The capacity control valve of Example 1 will be described below. Figure 1 The left and right sides when viewed from the front side are described as the left and right sides of the capacity control valve. Specifically, the left side of the paper on which the valve housing 10 is located is described as the left side of the capacity control valve, and the right side of the paper on which the solenoid 80, which serves as the drive source, is described as the right side of the capacity control valve.

[0042] The capacity control valve of the present invention is assembled in a variable capacity compressor (not shown) used in an air conditioning system of automobiles, etc., and performs variable control on the pressure of the refrigerant, i.e., the working fluid (hereinafter referred to as "fluid"), thereby controlling the discharge of the variable capacity compressor and adjusting the air conditioning system to the target cooling capacity.

[0043] First, the variable capacity compressor will be described. The variable capacity compressor has a housing comprising a discharge chamber, a suction chamber, a control chamber, and multiple cylinders. Furthermore, the variable capacity compressor has a connecting passage directly linking the discharge chamber and the control chamber, and this connecting passage has a fixed throttling orifice 9 (see reference) for balancing the pressure between the discharge chamber and the control chamber. Figure 1 ).

[0044] In addition, the variable capacity compressor has a rotating shaft, a swashplate, and multiple pistons. The rotating shaft is driven by a motor (not shown) located outside the housing. The swashplate is tiltably connected to the rotating shaft via a hinge mechanism within the control chamber. Multiple pistons are connected to the swashplate and are freely fitted into their respective cylinders. The variable capacity compressor uses a capacity control valve V1 driven by electromagnetic force to open and close. By utilizing the suction pressure Ps of the suction chamber for drawing in fluid, the discharge pressure Pd of the discharge chamber for discharging fluid pressurized by the piston, and the control pressure Pc of the control chamber housing the swashplate, the compressor continuously changes the tilt angle of the swashplate by appropriately controlling the pressure within the control chamber, thereby changing the piston stroke and controlling the fluid discharge rate.

[0045] like Figure 1 As shown, in this embodiment 1, the capacity control valve V1, assembled in a variable capacity compressor, adjusts the current energizing the coil 86 constituting the solenoid 80, thereby controlling the opening and closing of the CS valve 50 of the capacity control valve V1. This controls the fluid flowing from the control chamber (which is the primary pressure side) to the suction chamber (which is the secondary pressure side), thus allowing variable control of the control pressure Pc within the control chamber. Furthermore, the discharge fluid at the discharge pressure Pd of the discharge chamber is continuously supplied to the control chamber via the fixed orifice 9, and by closing the CS valve 50 of the capacity control valve V1, the control pressure Pc within the control chamber increases.

[0046] In the capacity control valve V1 of this embodiment 1, the CS valve 50 is a lift valve structure consisting of a CS valve core 51 (which serves as the valve core), a first valve seat 10a, and a second valve seat 40a. The first valve seat 10a is formed on an annular protrusion 10b that protrudes from the inner circumference of the valve housing 10 towards the inner diameter side. The second valve seat 40a is formed on the axial right end of a movable body 40 that moves axially via differential pressure, on the inner diameter side of the first valve seat 10a. The CS valve 50 is opened and closed by contacting or separating from the first valve seat 10a or the second valve seat 40a axially through an abutment portion 51a formed on the axial left end of the CS valve core 51. The first valve seat 10a and the second valve seat 40a are the valve seats of the present invention.

[0047] Next, the structure of the capacity control valve V1 will be described. For example... Figure 1 As shown, the capacity control valve V1 mainly consists of a valve body 10, a CS valve core 51, a movable body 40, and a solenoid 80. The valve body 10 is made of metal. The CS valve core 51 and the movable body 40 are axially reciprocating freely within the valve body 10. The solenoid 80 is connected to the valve body 10 and applies a driving force to the CS valve core 51.

[0048] like Figure 1As shown, the CS valve core 51 is formed of metal or resin material. In addition, the CS valve core 51 is composed of a large-diameter portion 51b, which is a columnar body with a constant cross-section, and a small-diameter portion 51c, which extends axially to the right from the inner diameter side of the axial right end of the large-diameter portion 51b, and also serves as a rod through which the coil 86 of the solenoid 80 passes.

[0049] An abutment portion 51a is formed on the axial left end face of the CS valve core 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 into a cross-sectional curved shape. Specifically, the curved shape of the abutment portion 51a is formed from a portion of a sphere having a constant radius of curvature. Furthermore, as long as the abutment portion 51a is shaped to be able to sit on the first valve seat 10a and the second valve seat 40a, it may not be formed from a portion of a sphere having a constant radius of curvature, and it may not be a curved surface.

[0050] like Figure 1 As shown, the solenoid 80 mainly consists of a housing 81, a central column 82, a CS valve core 51, a movable iron core 84, a helical spring 85, and an excitation coil 86. The housing 81 has an opening 81a that opens axially to the left. The central column 82 is generally cylindrical and is inserted into the opening 81a of the housing 81 from the axial left, positioned between the inner diameter side of the housing 81 and the inner diameter side of the valve housing 10. The CS valve core 51 is inserted into the central column 82 and can move freely axially, with its axial left end positioned within the valve housing 10. The axial right end of the CS valve core 51 is embedded and fixed in the movable iron core 84. The helical spring 85 is positioned between the central column 82 and the movable iron core 84, applying force to the movable iron core 84 in the opening direction of the CS valve 50, i.e., axially to the right. The helical spring 85 is wound around the outside of the central column 82 via a winding frame.

[0051] like Figure 1 As shown, an annular protrusion 10b protruding from the inner circumference towards the inner diameter side is formed approximately at the center of the valve housing 10 in the axial direction. A first valve seat 10a with an inclined cross-section is formed on this annular protrusion 10b. The first valve seat 10a is connected to the inner diameter side from the annular side on the right side in the axial direction and gradually narrows towards the left side in the axial direction. That is, the first valve seat 10a is composed of a conical surface with an inclined surface of straight cross-section extending circumferentially.

[0052] Additionally, a Ps port 11, serving as a secondary pressure port, is formed on the valve housing 10. The Ps port 11 extends radially to the right of the annular protrusion 10b and communicates with the suction chamber of the variable capacity compressor. Furthermore, a second Pc port 12, serving as a second primary pressure port, is formed on the valve housing 10. The second Pc port 12 extends radially to the left of the annular protrusion 10b and communicates with the control chamber of the variable capacity compressor. The second Pc port 12 has a tapered nozzle shape, with the flow path cross-sectional area decreasing towards the downstream side (dA < 0).

[0053] Additionally, 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. Furthermore, at the axial left end of the valve housing 10, a rectangular cross-section stop 41 is pressed and fixed in an annular stepped portion 10d formed at the axial left edge of the recess 10c, and a first Pc port, which communicates with the control chamber of the variable capacity compressor, is formed through a through hole 41a that passes through the stop 41 axially.

[0054] Inside the valve housing 10, a valve chamber 20 is formed at a position axially to the right of the annular protrusion 10b. An abutment portion 51a of the CS valve core 51 is disposed within the valve chamber 20, allowing for free axial reciprocating movement. Furthermore, the Ps port 11 extends from the outer periphery of the valve housing 10 in the inner diameter direction and communicates with the valve chamber 20.

[0055] Furthermore, inside the valve housing 10, an annular space 30 is formed by inserting the movable body 40 into a recess 10c located axially to the left of the annular protrusion 10b. Additionally, the second Pc port 12 extends from the outer periphery of the valve housing 10 in the inward diameter direction and communicates with the space 30.

[0056] Here, the movable body 40 will be described. For example... Figure 2 As shown, the movable body 40 is composed of a base 40c, a flange 40d, and an extension 40e serving as a closing portion, and is in the form of a double-cylinder shape with a flange. A through hole 40b extending axially through the base 40c is formed therein, and it is cylindrical. The flange 40d extends from the outer peripheral surface of the axially left end of the base 40c towards the outer diameter side, and is in the form of an annular plate. The extension 40e extends axially to the right from the outer diameter portion of the flange 40d, and is cylindrical.

[0057] The base 40c is inserted into the inner diameter side of the annular protrusion 10b of the valve housing 10, and its outer circumferential surface can slide against the inner circumferential surface of the annular protrusion 10b. Furthermore, a second valve seat 40a with an inclined cross-section is formed at the axial right end of the base 40c. The second valve seat 40a is connected to the annular flat surface 40f and the flat surface 40f from the inner diameter side, and gradually narrows in diameter towards the axial left from the outer diameter side to the inner diameter side. That is, the second valve seat 40a is composed of a tapered surface with an inclined cross-section extending circumferentially.

[0058] The outer peripheral surfaces of the flange portion 40d and the extension portion 40e can slide against the inner peripheral surface of the recess 10c of the valve housing 10. Furthermore, a small gap is formed between the outer peripheral surfaces of the flange portion 40d and the extension portion 40e and the inner peripheral surface of the recess 10c, and between the outer peripheral surface of the base portion 40c and the inner peripheral surface of the annular protrusion 10b, by slightly separating them radially. Thus, due to the formation of this small gap, the movable body 40 can smoothly move relative to the valve housing 10 axially. Additionally, a gap-sealing sealing portion is formed between the outer peripheral surfaces of the flange portion 40d and the extension portion 40e and the inner peripheral surface of the recess 10c.

[0059] Furthermore, the movable body 40 is subjected to force in the direction of separation from the CS valve core 51, i.e., axially to the left, by a helical spring 42, which serves as a force-applying unit, disposed within the space 30. Specifically, the helical spring 42 is embedded along the extension 40e of the movable body 40, and its axially right end abuts against the bottom surface of the recess 10c, i.e., the axially left side surface of the annular protrusion 10b. Additionally, the axially left end of the helical spring 42 abuts against the axially right inner side surface 40h of the flange 40d of the movable body 40. Furthermore, the helical spring 42 is a compression spring.

[0060] In addition, in the movable body 40, the inner surface 40h on the axial right side of the flange portion 40d facing the space 30 and the axial right end face 40g of the extension portion 40e constitute a pressure-bearing surface that always bears secondary pressure.

[0061] Additionally, the movable body 40 is forced axially to the left by the force of the coil spring 42. The axially left end face 40k of the movable body 40 abuts against the axially right side of the stop block 41, thereby restricting the movement of the movable body 40 to the left (see reference). Figure 2 and Figure 3 At this time, the axial right end of the base 40c is positioned on the inner diameter side of the annular protrusion 10b.

[0062] Thus, inside the valve housing 10, a first Pc-Ps flow path is formed, connecting the control chamber and the suction chamber of the variable capacity compressor, through the through hole 41a of the stop block 41, the through hole 40b of the movable body 40, the valve chamber 20, and the Ps port 11 (see reference). Figure 2 (The solid arrow in the middle).

[0063] Furthermore, a connecting passage 10e is formed on the inner circumferential surface of the annular protrusion 10b of the valve housing 10 by a groove extending axially. The connecting passage 10e also connects the space 30 and the valve chamber 20. That is, within the space 30, fluid at primary pressure can flow through the second Pc port 12, and fluid at secondary pressure can flow through the connecting passage 10e. Thus, inside the valve housing 10, a second Pc-Ps flow path (see reference 11) is formed, connecting the control chamber and the suction chamber of the variable capacity compressor, via the second Pc port 12, the space 30, the connecting passage 10e, the valve chamber 20, and the Ps port 11. Figure 2 (The solid arrow in the middle).

[0064] Furthermore, in this embodiment 1, the second Pc port 12 is formed as a tapered nozzle shape in which the flow path cross-sectional area decreases as it moves downstream (dA < 0). Additionally, the flow path cross-sectional area of ​​the second Pc port 12 continuously decreases as it moves downstream.

[0065] Here, the changes in velocity and pressure of the fluid passing through the second Pc port 12 are explained. Regarding the effect of area changes in isentropic flow, the relationship between cross-sectional area and pressure is shown below.

[0066] [Formula 1]

[0067]

[0068] p: pressure

[0069] γ: Specific heat ratio

[0070] M: Mach number

[0071] A: Area

[0072] Based on the relationship between cross-sectional area and pressure, when the fluid flowing through the second Pc port 12 is a subsonic flow (M < 1), the flow velocity of the fluid flowing through the second Pc port 12 increases. Additionally, the fluid pressure decreases. Therefore, the pressure Pc' of the fluid flowing into the space 30 from the second Pc port 12 is smaller than the control pressure Pc of the control fluid in the through hole 41a of the baffle 41 (Pc' < Pc).

[0073] Next, the opening and closing mechanism of CS valve 50 will be explained. For example... Figure 2 As shown, in the unenergized state of the capacity control valve V1, the coil spring 85 (refer to...) Figure 1 The force of the CS valve core 51 is pressed to the right axially, and the CS valve 50 is fully opened.

[0074] In addition, such as Figure 3 As shown, when the capacity control valve V1 is energized (maximum energized state), the CS valve core 51 is driven by the solenoid 80 through the coil spring 85 (see reference). Figure 1 The force of the CS valve core 51 moves to the left axially, and the abutment part 51a of the CS valve core 51 sits on the first valve seat 10a, thereby closing the CS valve 50.

[0075] like Figure 2 and Figure 3 As shown, when the pressure difference between the primary and secondary pressures acting axially on the movable body 40 is small, the movable body 40 bears the force of the helical spring 42 in the direction of separation from the CS valve core 51 (in Figure 2 and Figure 3 (Illustrated with a white arrow in the middle), it moves axially to the left. Furthermore, the movable body 40 is restricted in its movement by abutting against the stop 41 via its axially left end face 40k. Specifically, a primary pressure acts on the axially left end face 40k of the movable body 40, and a pressure between the primary and secondary pressures acts primarily on the inner surface 40h on the axially right side of the flange portion 40d, the axially right end face 40g of the extension portion 40e, and the second valve seat 40a and flat surface 40f at the axially right end of the base portion 40c. At this time, the axially right end face 40g of the extension portion 40e of the movable body 40 is positioned axially to the left of the opening on the space 30 side of the second Pc port 12, thereby fully opening the second Pc port 12.

[0076] On the other hand, when the differential pressure acting on the movable body 40 along the axial direction is large (e.g., when the primary pressure is high), the coil spring 42 will contract when the force acting on the movable body 40 through the differential pressure exceeds the force of the coil spring 42. Additionally, when the movable body 40 moves towards the CS valve core 51, i.e., axially to the right, the movement is restricted by the contact between the axially right end face 40g of the extension 40e and the bottom surface of the recess 10c of the valve housing 10 (see reference). Figure 4 At this time, the second Pc port 12 is closed by the sealing part, which is sealed by the gap between the outer peripheral surface of the axial right end of the extension 40e of the movable body 40 and the inner peripheral surface of the recess 10c.

[0077] Thus, the movable body 40 moves axially by balancing the differential pressure acting on it along the axial direction with the force of the helical spring 42. That is, the movable body 40 moves independently of the CS valve core 51, which moves by the driving force of the solenoid 80.

[0078] In addition, such as Figure 4As shown, with the right-hand axial end face 40g of the extension 40e of the movable body 40 abutting against the bottom surface of the recess 10c of the valve housing 10, the flat surface 40f of the right-hand axial end of the base 40c on the inner diameter side of the first valve seat 10a is positioned in an axial position approximately radially flush with the side surface on the right-hand axial side of the annular protrusion 10b. Therefore, when the valve is closed in the energized state of the capacity control valve V1, the abutting portion 51a of the CS valve core 51 can reach a position with a stroke greater than required to seat on the first valve seat 10a (see reference). Figure 3 The small stroke is placed on the second valve seat 40a to close the CS valve 50.

[0079] Furthermore, the second valve seat 40a is positioned closer to the inner diameter side than the first valve seat 10a and is formed with a smaller diameter. Therefore, the pressure-bearing area A1 (refer to...) when the contact portion 51a with the CS valve core 51 is seated on the first valve seat 10a... Figure 5 Compared to this, it can reduce the pressure-bearing area A2 of the CS valve core 51 when the abutment portion 51a is seated on the second valve seat 40a (refer to...). Figure 4 (A1>A2). That is, the valve port diameter of the second valve seat 40a is smaller, and the resistance to the primary pressure acting on the movable body 40 of the abutment part 51a of the CS valve core 51 from the axial right is reduced, so the CS valve 50 can be closed with a smaller driving force of the solenoid 80.

[0080] In addition, from Figure 4 The state shown indicates that until the CS valve core 51 moves further axially to the left and the abutment portion 51a of the CS valve core 51 sits on the first valve seat 10a, the resistance experienced by the CS valve core 51 from the primary pressure within the through hole 40b of the movable body 40 is based on the aforementioned smaller pressure-bearing area A2, thus reducing the driving force of the solenoid 80 required for the CS valve 50 to close. Furthermore, in Figure 5 In the state shown, by placing the abutment portion 51a of the CS valve core 51 onto the first valve seat 10a, even if the movable body 40 moves axially to the left due to the change in differential pressure acting on the movable body 40 axially, the CS valve 50 can be kept closed.

[0081] At this time, as the CS valve core 51 moves, the movable body 40 is pressed to the left in the axial direction. The right end face 40g of the extension 40e separates from the bottom of the recess 10c of the valve housing 10 to the left in the axial direction. The right end face 40g of the extension 40e is positioned to the right of the opening on the space 30 side of the second Pc port 12, thereby maintaining the state of closing the second Pc port 12 and preventing fluid leakage.

[0082] In addition, the inner surface 40h on the right side of the flange portion 40d facing the space 30 and the right end face 40g on the extension portion 40e of the movable body 40 are pressure-bearing surfaces that always bear secondary pressure. Therefore, the differential pressure between the primary pressure and the secondary pressure can always act on the movable body 40, thereby improving the responsiveness to differential pressure.

[0083] In addition, the movable body 40 is forced by the helical spring 42 in the direction of separation from the CS valve core 51, so that when the differential pressure acting on the movable body 40 is small, the movable body 40 can be reliably separated from the CS valve core 51.

[0084] Furthermore, within space 30, fluids at primary pressure and fluids at secondary pressure can flow. Therefore, within space 30, in addition to the secondary pressure supplied from valve chamber 20 (which serves as the secondary pressure side) via connecting passage 10e, primary pressure is also supplied through the second Pc port 12. Thus, the differential pressure acting on the movable body 40 can be adjusted according to the primary pressure, thereby improving the responsiveness of the movable body 40.

[0085] Furthermore, by forming a connecting passage 10e between the space 30 and the valve chamber 20, when the movable body 40 moves axially to the right, fluid can move from the space 30 to the valve chamber 20 through the connecting passage 10e, thus enabling the movable body 40 to move smoothly.

[0086] Furthermore, the second Pc port 12 is a tapered nozzle whose flow path cross-sectional area decreases as it flows downstream. 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. Therefore, the differential pressure acting on the movable body 40 can be increased. As a result, the movable body 40 can easily access the CS valve core 51.

[0087] In addition, the helical spring 42 is arranged in the space 30, which enables the movable body 40 and the CS valve core 51 to move independently, thereby improving the responsiveness of the movable body 40.

[0088] In addition, such as Figure 2 As shown, in the unpowered state, when the differential pressure is small, both CS valve 50 and the second Pc port 12 are fully opened, thereby increasing the fluid flow rate through both the first Pc-Ps flow path and the second Pc-Ps flow path.

[0089] In addition, the capacity control valve V1 has a structure in which the movable body 40 and the helical spring 42 are inserted into the recess 10c from the axial left end of the valve body 10, and then the stop block 41 is pressed in and fixed, so it is easy to assemble.

[0090] [Example 2]

[0091] Reference Figure 6The capacity control valve of Example 2 will be described. Furthermore, descriptions that are identical to or repeat the same as those in Example 1 will be omitted.

[0092] like Figure 6 As shown, in the capacity control valve V2 of this embodiment 2, a Pc port 112 serving as a second primary pressure port is formed on the valve housing 110. The Pc port 112 has a gradually expanding nozzle shape in which the flow path cross-sectional area increases as it moves downstream (dA > 0).

[0093] Based on the relationship between cross-sectional area and pressure in Embodiment 1 above, when the fluid flowing through port 112 is a supersonic flow (M > 1), the fluid velocity through port 112 will increase and the pressure will decrease. Therefore, the pressure Pc' of the fluid flowing into the space 30 from port 112 is smaller than the control pressure Pc of the control fluid in the through hole 41a of the baffle 41 (Pc' < Pc). Therefore, the differential pressure acting on the movable body 40 can be increased, making it easier for the movable body 40 to approach the CS valve core 51.

[0094] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments. Any changes or additions that do not depart from the spirit of the present invention are also included in the present invention.

[0095] For example, in the above embodiments 1 and 2, it was described that when the movable body 40 moves to the right axially, the flat surface 40f of the axially right end of the base 40c on the inner diameter side of the first valve seat 10a is arranged in an axial position that is approximately radially flush with the side surface of the axially right side of the annular protrusion 10b. However, it is not limited to this. As long as when the movable body 40 moves to the right axially, the abutting portion 51a of the CS valve core 51 sits on the second valve seat 40a before the first valve seat 10a.

[0096] Furthermore, in embodiments 1 and 2 described above, the second Pc ports 12 and 112 connecting the primary pressure side and the space 30 are described as forming a gradually converging / expanding nozzle shape with a continuously increasing / decreasing flow path cross-sectional area. However, this is not limited to this; the flow path cross-sectional area can also be increased / decreasing in stages. Alternatively, the Pc ports connecting the primary pressure side and the space 30 can also have a constant flow path cross-sectional area.

[0097] Alternatively, the fluid under primary pressure may not flow within the space of 30.

[0098] In addition, the connecting path 10e is not limited to a groove, but can also be formed by a through hole that passes through the annular protrusion 10b along the axial direction.

[0099] Alternatively, the CS valve core 51 may not have a cross-sectional curved shape for the abutment portion 51a. For example, it may be formed into a stepped shape that can abut against the first valve seat 10a and the second valve seat 40a respectively.

[0100] In addition, the conical surfaces constituting the first valve seat 10a and the second valve seat 40a are not limited to being straight, but can also be arc-shaped.

[0101] In addition, the capacity control valves V1 and V2 of Embodiments 1 and 2 above have been described using CS valve 50 as an example, but it is not limited to this. It can also be a DC valve that opens and closes the flow path between the Pd port, which is the primary pressure port, and the Pc port, which is the secondary pressure port.

[0102] Symbol Explanation

[0103] 9: Fixed throttling orifice; 10: Valve body; 10a: First valve seat; 10b: Annular protrusion; 10c: Recess; 10d: Stepped portion; 10e: Connecting path; 11: Ps port (secondary pressure port); 12: Second Pc port (secondary primary pressure port); 20: Valve chamber; 30: Space; 40: Movable body; 40a: Second valve seat; 40b: Through hole; 40c: Base; 40d: Flange; 40e: Extension (closing portion); 40f: Flat surface; 40g: Axial right end Surface (the pressure-bearing surface that always bears secondary pressure); 40h: Side surface (the pressure-bearing surface that always bears secondary pressure); 40k: Axial left end face; 41: Stop block; 41a: Through hole (primary pressure port, first Pc port); 42: Helical spring (force application unit); 50: CS valve; 51: CS valve core (valve core); 51a: Abutment part; 80: Solenoid; 85: Helical spring (spring); 110: Valve body; 112: Second Pc port (second primary pressure port); V1, V2: Capacity control valve (valve).

Claims

1. A valve comprising: The valve body has a primary pressure port and a secondary pressure port. The valve core, which is driven by a drive source; and Valve seat, which provides a place for the valve core to sit. in, The valve seat includes: a first valve seat; and a second valve seat, which is disposed on the inner diameter side of the first valve seat and moves toward the valve core by the pressure difference between the primary pressure and the secondary pressure. The movable body forming the second valve seat has a pressure-bearing surface that is always subjected to secondary pressure.

2. The valve according to claim 1, wherein, The movable body is forced by the force-applying unit in the direction of separation from the valve core.

3. The valve according to claim 2, wherein, Within the space faced by the pressure-bearing surface, fluids at primary pressure and fluids at secondary pressure can flow.

4. The valve according to claim 3, wherein, The force-applying unit is disposed within the space.

5. The valve according to claim 3 or 4, wherein, The movable body has a closing part that, when the valve core is seated in the second valve seat, closes the second primary pressure port that allows fluid at the primary pressure to flow within the space.

6. The valve according to claim 5, wherein, The second primary pressure port is a tapered nozzle whose flow path cross-sectional area decreases as it moves downstream.

7. The valve according to claim 5, wherein, The second primary pressure port is a gradually expanding nozzle whose flow path cross-sectional area increases as it moves downstream.

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