valve

Abstract

The present invention provides a valve with high controllability. The valve (V1) includes: a valve body (10) having an inlet port (40b) and an outlet port (11); a valve core (51) driven by a drive source (80); a spring (85) applying force to the valve core (51) in a direction opposite to the driving direction of the drive source (80); and a lift valve (50) consisting of a valve seat (40a) formed at the edge of a through flow path (40b) and the valve core (51). The valve (V1) controls the flow rate by moving the valve core (51), wherein an increasing region is provided in the flow path (C1, C2) downstream of the lift valve (50), the cross-sectional area of ​​the flow path increasing as it moves downstream.

Description

Technical Field

[0001] This invention relates to a valve for variable control of working fluid, for example, to a 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 driven by an engine, a swashplate connected to the rotating shaft at a variable angle, and a compression piston connected to the swashplate. The amount of fluid discharged is controlled by changing the stroke of the piston through altering the swashplate's tilt angle. A capacity control valve, driven by electromagnetic force, controls the pressure within the control chamber 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. 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 normally controlled as follows: the control computer is energized and controlled to move the valve core axially by the electromagnetic force generated by the solenoid, thereby opening and closing the valve 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, in order to adjust the control pressure Pc of 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 control pressure Pc and the 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 a 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] The capacity control valve in Patent Document 1, which controls fluid flow by opening and closing a lift valve, utilizes the pressure difference between the control pressure Pc (lower than the discharge pressure Pd) and the suction pressure Ps. This reduces the fluid flow through the lift valve. However, due to the continuous supply of the discharge pressure Pd through the throttling orifice to adjust the control pressure Pc, even with a pre-set current input to the solenoid, the valve core stroke sometimes deviates, causing the valve opening to deviate from the target value. Based on the inventors' research, it was determined that the valve core stroke can be influenced by allowing a refrigerant to flow at near-sonic speeds through the lift valve, and this deviation can be used to suppress the aforementioned deviation.

[0011] This invention was made in response to such a problem, and its purpose is to provide a valve with high controllability.

[0012] Methods for solving problems

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

[0014] The valve body has an inlet port and an outlet port;

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

[0016] A spring that applies force to the valve core in a direction opposite to the driving direction of the drive source; and

[0017] A lift valve, comprising a valve seat formed at the edge of a flow path and a valve core, controls the flow rate by moving the valve core.

[0018] An increasing region is provided in the flow path on the downstream side of the lift valve, where the cross-sectional area of ​​the flow path tends to increase as it goes downstream.

[0019] Therefore, when the fluid flowing through the lift valve is supersonic, the fluid velocity increases in the increased region of the flow path downstream of the lift valve, causing the downstream pressure of the lift valve to decrease. This allows the force acting on the valve core in the opening direction to suppress the influence of the upstream fluid pressure on the back pressure acting on the valve core, thus suppressing the deviation of the valve core stroke relative to the current value input to the solenoid. Conversely, when the fluid flowing through the lift valve is subsonic, the fluid velocity decreases in the increased region of the flow path downstream of the lift valve, causing the downstream pressure of the lift valve to increase. This allows the force acting on the valve core in the closing direction to improve the closing characteristics, enabling the lift valve to close with a smaller current value. This allows for high-precision adjustment of the lift valve opening.

[0020] Alternatively, the cross-sectional area of ​​the flow path in the increased region may be continuously increased.

[0021] This allows for the stabilization and elimination of fluid flow in the downstream flow path of the lift valve by increasing the area of ​​flow.

[0022] Alternatively, the lifting valve may consist of a valve seat with an inclined cross-section and a valve core with a curved cross-section.

[0023] This creates an increased area between the valve seat and the valve core that constitute the lift valve, thus enabling the flow of fluid through the lift valve to be tangential and stable at the valve core's closed or throttling position.

[0024] Alternatively, the inclined shape can be a straight line.

[0025] Therefore, the flow of fluid through the lift valve at the valve core's closed or throttling position is directed tangentially and guided along the inclined surface, thus stabilizing the fluid flow to the downstream side of the lift valve.

[0026] Alternatively, the inclined surface constituting the valve seat may be continuous with the opening of the outlet port.

[0027] Thus, the flow of fluid through the lift valve is guided along the inclined surface that forms the valve seat to the opening of the outlet port, thereby stabilizing the downstream pressure of the lift valve.

[0028] Alternatively, the valve seat may be formed in a valve seat component that is separate from the valve housing.

[0029] This allows the inclined surface that forms the valve seat to be extended to the vicinity of the outlet port. Attached Figure Description

[0030] 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;

[0031] Figure 2 This is a cross-sectional view showing the valve seat component being pressed into the valve housing of the capacity control valve of Embodiment 1;

[0032] Figure 3 This is an enlarged cross-sectional view showing the increased region in the flow path downstream of the CS valve when the capacity control valve of Embodiment 1 is energized (under normal control).

[0033] Figure 4 (a) is a diagram schematically showing the valve-closing characteristics of the capacity control valve of Example 1 in supersonic flow, where the flow path cross-sectional area tends to increase. Figure 4(b) is a diagram schematically showing the closed-valve characteristics of a comparative example with a constant flow path cross-sectional area;

[0034] Figure 5 (a) is a diagram schematically showing the valve-closing characteristics of the capacity control valve of Example 1 in subsonic flow, where the flow path cross-sectional area tends to increase. Figure 5 (b) is a diagram schematically showing the closed-valve characteristics of a comparative example with a constant flow path cross-sectional area;

[0035] 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;

[0036] Figure 7 (a) is a cross-sectional view showing the valve seat component being pressed into the valve body of the capacity control valve of Embodiment 2. Figure 7 (b) shows the view from the outer diameter side of the valve housing. Figure 7 (a) A diagram of the Ps port at the XX section;

[0037] Figure 8 This is an enlarged cross-sectional view showing the increased region in the flow path downstream of the CS valve when the capacity control valve of Embodiment 2 is energized (under normal control). Detailed Implementation

[0038] 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.

[0039] [Example 1]

[0040] Reference Figures 1 to 3 The capacity control valve of Example 1 will be described below. Figure 1 The left and right sides when viewed from the front side will be 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 will be described as the left side of the capacity control valve, and the right side of the paper on which the solenoid 80 is located will be described as the right side of the capacity control valve.

[0041] 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.

[0042] First, the variable capacity compressor will be described. The variable capacity compressor has a housing containing 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. 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 ).

[0043] 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.

[0044] 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, which constitutes the solenoid 80 as a drive source, to control the opening and closing of the CS valve 50, which serves as a lift valve, of the capacity control valve V1. Thus, the control pressure Pc in the control chamber is variably controlled by controlling the fluid flowing from the control chamber to the suction 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 the control pressure Pc in the control chamber increases by closing the CS valve 50 of the capacity control valve V1.

[0045] In the capacity control valve V1 of this embodiment 1, the CS valve 50 is composed of a CS valve core 51 as the valve core and a CS valve seat 40a as the valve seat. The CS valve seat 40a is formed in a cylindrical valve seat component 40, which is pressed into and fixed to a recess 10a in the valve housing 10. The CS valve 50 is opened and closed by contacting or separating from the CS valve seat 40a axially through an abutment portion 51a formed at the axial left end of the CS valve core 51.

[0046] 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 valve seat assembly 40, a CS valve core 51, and a solenoid 80. The valve body 10 and the valve seat assembly 40 are made of metal. The CS valve core 51 is 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.

[0047] like Figure 1 As shown, the CS valve core 51 consists of a large-diameter portion 51b and a small-diameter portion 51c. The large-diameter portion 51b is formed of a metal or resin material and is a columnar body with a constant cross-section. The small-diameter portion 51c extends axially to the right from the inner diameter side of the axially right end of the large-diameter portion 51b. In addition, the CS valve core 51 also serves as a rod through which the coil 86 of the solenoid 80 passes.

[0048] 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, an abutment portion 51a with a cross-sectional curved shape bulging toward the CS valve seat 40a is formed. Specifically, the curved shape of the abutment portion 51a is formed from a portion of a sphere with a constant radius of curvature. Furthermore, as long as the abutment portion 51a has a curved shape that can sit on the CS valve seat 40a, it may not be formed from a portion of a sphere with a constant radius of curvature.

[0049] 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 inserted into the opening 81a of the housing 81 from the left, positioned between the inner diameter side of the housing 81 and the inner diameter side of the valve housing 10, and is formed into a generally cylindrical shape. The CS valve core 51 is inserted through the central column 82 and can move freely back and forth axially, with its axial left end positioned inside the valve housing 10. The axial right end of the CS valve core 51 is inserted 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, and applies force to the movable iron core 84 in the opening direction of the CS valve 50, i.e., axially to the right. The coil 86 is wound around the outside of the central column 82 via a winding frame.

[0050] The central column 82 has a cylindrical portion 82b and an annular flange portion 82d. The cylindrical portion 82b is formed of a rigid body made of magnetic material such as iron or silicon steel, and has an insertion hole 82c extending axially for the CS valve core 51 to pass through. The flange portion 82d extends from the outer circumference of the axial left end of the cylindrical portion 82b in the outward diameter direction.

[0051] like Figure 1 As shown, a Ps port 11 serving as an outlet port is formed on the valve housing 10. The Ps port 11 extends radially and communicates with the suction chamber of the variable capacity compressor. Additionally, a recess 10a is formed on the axial left side of the valve housing 10 to press the cylindrical valve seat member 40 inward from the axial left. Furthermore, a Pc port serving as an inlet port is formed on the valve housing 10. By pressing and fixing the valve seat member 40 into the recess 10a, the Pc port communicates with the control chamber of the variable capacity compressor through a through hole 40b extending axially through the valve seat member 40.

[0052] A valve chamber 20 is formed inside the valve housing 10, and the abutment portion 51a of the CS valve core 51 is disposed within the valve chamber 20 and can freely reciprocate axially. In addition, 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.

[0053] Thus, inside the valve housing 10, a flow path is formed through the through hole 40b of the valve seat component 40, the valve chamber 20, and the Ps port 11, connecting the control chamber and the suction chamber of the variable capacity compressor.

[0054] Additionally, a guide hole 10c is formed on the inner circumferential surface of the valve housing 10. The guide hole 10c is formed on the outer circumferential surface 51d of the large diameter portion 51b of the CS valve core 51, which is located on the axial right side of the valve chamber 20 relative to the mounting solenoid 80 (see reference). Figure 3 It can slide within it. In addition, a small gap is formed between the inner circumferential surface of the guide hole 10c and the outer circumferential surface 51d of the large diameter portion 51b of the CS valve core 51 by slightly separating them in the radial direction, so that the CS valve core 51 can move smoothly relative to the valve body 10 in the axial direction.

[0055] like Figure 2 As shown, the recess 10a of the valve housing 10 is formed such that its inner diameter R1 is larger than the inner diameter R2 of the valve chamber 20 (R1 > R2). Thus, the bottom surface of the recess 10a forms a receiving portion 10b that can abut against the flat surface 40c on the axial right side of the valve seat component 40.

[0056] like Figure 1 As shown, the valve housing 10 has a recess 10d formed on the axial right side that is recessed to the axial left. The recess 10d is fixed by the flange portion 82d of the central post 82 from the axial right side in a substantially sealing manner, and the outer casing 81 is fixed by the flange portion 82d of the central post 82 from the axial right side in a substantially sealing manner, thereby being integrally connected.

[0057] Thus, with the valve housing 10, the central column 82, and the outer shell 81 integrally connected, the axial right end face of the valve housing 10 and the axial right side face of the flange portion 82d of the central column 82 respectively abut against the bottom surface of the recess 81b formed on the axial left side of the outer shell 81, and the bottom surface of the recess 10d of the valve housing 10 and the axial left end face of the central column 82 are separated axially to form a gap.

[0058] Additionally, a through hole 21 is formed on the valve housing 10. The through hole 21 extends axially between the axial left end face of the valve housing 10 and the bottom of the recess 10d. The through hole 21 consists of a small-diameter bore 211, whose axial left end communicates with the control chamber of the variable capacity compressor; and a large-diameter bore 212, which extends continuously from the axial right end of the small-diameter bore 211 and has a larger diameter than the small-diameter bore 211. The axial right end of the large-diameter bore 212 opens into the gap between the bottom surface of the recess 10d and the axial left end face of the central column 82. Furthermore, control fluid with control pressure Pc is supplied from the control chamber of the variable capacity compressor within the small-diameter bore 211 of the through hole 21 and within the through hole 40b of the valve seat component 40.

[0059] A spherical working valve core 31 and a return spring 32 are disposed in the large-diameter bore 212 of the through-hole 21. The axial right end of the return spring 32 is fixed to the axial left end face of the central column 82, and the axial left end abuts against the working valve core 31 from the axial right. In addition, the working valve core 31 is forced axially to the left by the return spring 32. These working valve cores 31 and return spring 32 constitute a pressure working valve 30, which controls the communication between the control chamber of the variable capacity compressor and the space S inside the housing 81 in the through-hole 21.

[0060] For ease of explanation, illustrations are omitted. However, when the control pressure Pc is high, the working valve core 31 of the pressure working valve 30 overcomes the force of the return spring 32 and the pressure of the fluid in the space S inside the housing 81 and moves axially to the right. It also separates from the valve seat 213 with an inclined cross-section at the connection between the axial right end of the small diameter bore 211 and the axial left end of the large diameter bore 212 formed in the through hole 21, thereby opening the pressure working valve 30. As a result, the control chamber of the variable capacity compressor and the space S inside the housing 81 are connected through the through hole 21. Control fluid with control pressure Pc is supplied from the control chamber of the variable capacity compressor to the space S inside the housing 81 through the through hole 21. The pressure difference between the fluid in the space S inside the housing 81 and the control fluid in the through hole 40b of the valve seat component 40 decreases, allowing the CS valve core 51 to move smoothly to the axial left, i.e., in the valve closing direction, thereby improving the control responsiveness of the variable capacity compressor at high output.

[0061] Furthermore, in the valve housing 10, the small gap between the inner circumferential surface of the guide hole 10c and the outer circumferential surface of the large-diameter portion 51b of the CS valve core 51 functions as a throttling element. This allows fluid within the space S inside the housing 81 to be slowly released to the Ps port 11. During prolonged periods of non-use, the pressure difference between the fluid pressure inside the valve chamber 20 and the fluid pressure within the space S inside the housing 81 is maintained at a small level.

[0062] Here, the valve seat component 40 will be described. For example... Figure 2 As shown, the valve seat component 40 is formed of a metal material that is harder than the metal material used in the valve body 10. Furthermore, the valve seat component 40 is formed of a different material than the CS valve core 51.

[0063] Furthermore, the valve seat component 40 is cylindrical with a through hole 40b extending axially. A CS valve seat 40a with an inclined cross-section is formed at the axial right end of the valve seat component 40. The CS valve seat 40a is formed from the outer diameter side to the inner diameter side, connecting to the annular flat surface 40c and the flat surface 40c from the inner diameter side and gradually narrowing towards the left axially. That is, the CS valve seat 40a is formed at the edge of the through hole 40b, which serves as a through flow path, and is composed of a tapered surface with an inclined cross-section extending circumferentially.

[0064] Additionally, by axially contacting the flat surface 40c on the right side of the valve seat component 40 with the receiving portion 10b formed by the bottom surface of the recess 10a (see reference) Figure 3 This allows for the specification of the insertion progress of the valve seat component 40 relative to the recess 10a, and improves the sealing performance between the valve body 10 and the valve seat component 40. In this case, the outer diameter end of the conical surface constituting the CS valve seat 40a is configured to connect with the axial left end of the inner circumferential surface 10e of the valve chamber 20 of the valve body 10.

[0065] Thus, through the flow path C1 formed between the conical surface of the CS valve seat 40a constituting the valve seat component 40 and the abutment portion 51a of the CS valve core 51, the flow path C2 formed between the conical surface of the CS valve seat 40a constituting the CS valve core 51 and the outer peripheral surface 51d of the large diameter portion 51b of the CS valve core 51, and the flow path C2 formed between the inner peripheral surface 10e of the valve housing 10 and the outer peripheral surface 51d of the large diameter portion 51b of the CS valve core 51, a flow path extending to the downstream side of the CS valve 50 at the opening on the valve chamber 20 side of the Ps port 11 is formed (see reference). Figure 3 ).also, Figure 3 This shows the state in which the CS valve core 51 is throttled to a position near the closed position under normal control of the capacity control valve V1.

[0066] In this embodiment 1, flow path C1 forms an increased region as follows: the cross-sectional area A2 of the flow path between the conical surface constituting the CS valve seat 40a and the outer diameter end of the abutment portion 51a of the CS valve core 51 is larger than the cross-sectional area A1 between the inner diameter end of the conical surface constituting the CS valve seat 40a and the abutment portion 51a of the CS valve core 51 (A1 < A2), and the cross-sectional area of ​​the flow path tends to increase as it moves downstream (dA > 0). Furthermore, flow path C2 forms an increased region as follows: the cross-sectional area A4 of the flow path between the inner circumferential surface 10e of the valve body 10 and the outer circumferential surface 51d of the CS valve core 51 is larger than the cross-sectional area A3 between the conical surface constituting the CS valve seat 40a and the outer circumferential surface 51d of the large diameter portion 51b of the CS valve core 51 (A3 < A4), and the cross-sectional area of ​​the flow path tends to increase as it moves downstream (dA > 0). Moreover, during normal control of the capacity control valve V1, when the CS valve core 51 is driven to the throttling position... Figure 3 Under these conditions, the cross-sectional area A3 of the upstream side of flow path C2 is larger than the cross-sectional area A2 of the downstream side of flow path C1 (A2 < A3).

[0067] Furthermore, an additional region is formed in the flow path on the downstream side of the CS valve 50 within the stroke range of the abutment portion 51a of the CS valve core 51.

[0068] Furthermore, the cross-sectional area of ​​flow path C1 increases continuously as it moves downstream. On the other hand, in flow path C2, the inner circumferential surface 10e of valve housing 10 is arranged parallel to the outer circumferential surface 51d of CS valve core 51, so the cross-sectional area A4 of flow path C2 on the downstream side is constant.

[0069] Next, the changes in the flow velocity and pressure of the fluid in flow paths C1 and C2 downstream of CS valve 50 will be explained. Furthermore, the case where the control pressure Pc is controlled within the range required to keep the aforementioned pressure operating valve 30 closed will be explained. Regarding the effect of area changes in isentropic flow, the relationship between cross-sectional area and pressure is shown below.

[0070] [Formula 1]

[0071]

[0072] p: pressure

[0073] γ: Specific heat ratio

[0074] M: Mach number

[0075] A: Area

[0076] Based on the relationship between cross-sectional area and pressure, when the pressure difference between the control pressure Pc in the through hole 40b of the valve seat component 40 and the suction pressure Ps in the Ps port 11, i.e., the Pc-Ps differential pressure, is large and the fluid passing through the CS valve 50 is a supersonic flow (M>1), the fluid passing through flow path C1 will experience an increase in velocity and a decrease in pressure. Flow path C1 constitutes an increasing region in the downstream flow path of the CS valve 50 where the cross-sectional area tends to increase as it moves downstream (dA>0). Furthermore, the fluid passing through flow path C2 will experience a further increase in velocity and a decrease in pressure, and then, through the downstream side of flow path C2 with a constant cross-sectional area, it will flow stably with approximately constant velocity and pressure, flowing into the Ps port 11. Flow path C2 is continuous with the downstream side of flow path C1 and constitutes an increasing region where the cross-sectional area tends to increase as it moves downstream (dA>0) (see reference). Figure 3 ).

[0077] On the other hand, when the Pc-Ps differential pressure is small and the fluid through CS valve 50 is a subsonic flow (M < 1), the fluid through flow path C1 will experience a decrease in velocity and an increase in pressure, where flow path C1 forms an increasing region in the flow path downstream of CS valve 50. Furthermore, the fluid through flow path C2 will experience a further decrease in velocity and an increase in pressure, and then flow steadily downstream of flow path C2, which has a constant cross-sectional area, into Ps port 11. Flow path C2 is continuous downstream of flow path C1 and forms an increasing region where the cross-sectional area of ​​the flow path increases as it moves downstream (dA > 0) (see reference). Figure 3 ).

[0078] Furthermore, the downstream pressure of CS valve 50, i.e., the pressure of the fluid in valve chamber 20, is easily affected by the control pressure Pc in the control chamber of the variable capacity compressor via the fixed throttle orifice 9 (see reference). Figure 1 The pressure Pd is constantly supplied, so the pressure is difficult to decrease compared to that inside port 11.

[0079] In this embodiment 1, as described above, the fluid flows through the increased region at supersonic speed, thereby reducing the downstream pressure of the CS valve 50. This suppresses the influence of the discharge pressure Pd on the space S inside the housing 81 (refer to...) which varies based on the pressure difference between the discharge pressure Pd and the pressure of the fluid within the valve chamber 20. Figure 1 The pressure of the fluid inside the housing 81, i.e., the force generated by the back pressure acting on the CS valve core 51, is affected. In addition, the fluid flows through the increased area at a subsonic speed, thereby increasing the downstream pressure of the CS valve 50 in addition to the effect of the discharge pressure Pd. Therefore, the pressure of the fluid inside the space S inside the housing 81, which varies based on the pressure difference with the fluid pressure inside the valve chamber 20, i.e., the force generated by the back pressure acting on the CS valve core 51, is further increased.

[0080] As described above, in the capacity control valve V1 of this embodiment 1, flow paths C1 and C2 are provided in the flow path downstream of the CS valve 50, forming an increasing region where the cross-sectional area of ​​the flow path tends to increase as it moves downstream (dA > 0). When the fluid passing through the CS valve 50 is a supersonic flow (M > 1), the fluid passing through flow paths C1 and C2 will have an increased velocity and decreased pressure, exerting a force in the valve opening direction on the CS valve core 51. Therefore, as... Figure 4 As shown in (a), the pressure of the fluid upstream of the CS valve 50, specifically the discharge pressure Pd in ​​this embodiment, can be suppressed to influence the downstream pressure of the CS valve 50. Furthermore, in Figure 4 (b) shows the characteristics of a flow path with a constant cross-sectional area (dA = constant), where the deviation of the drive current increases. This suppresses the influence of the discharge pressure Pd on the force generated by the back pressure acting on the CS valve core 51, suppresses the deviation of the stroke of the CS valve core 51 relative to the current value input to the solenoid 80, and enables high-precision adjustment of the opening of the CS valve 50.

[0081] Furthermore, when the fluid flowing through CS valve 50 is subsonic (M < 1), the fluid velocity through flow paths C1 and C2 will decrease and the pressure will increase, exerting a force on CS valve core 51 in the valve-closing direction. Additionally, this can further increase the force generated by the back pressure acting on CS valve core 51, influenced by the discharge pressure Pd. Therefore, as... Figure 5 As shown in (a), the closing characteristics of CS valve 50 can be improved, allowing CS valve 50 to close with a smaller current value. Additionally, in Figure 5 (b) shows the characteristics of a flow path with a constant cross-sectional area (dA = constant). In this case, the valve cannot be closed when the discharge pressure Pd is high. In other words, closing the valve requires a large current.

[0082] In this way, flow paths C1 and C2 are provided in the flow path on the downstream side of CS valve 50, which are increasing regions whose cross-sectional area increases as they go downstream (dA > 0). By appropriately controlling the downstream pressure of CS valve 50 according to the flow rate of the fluid passing through CS valve 50, the controllability of CS valve 50 can be improved.

[0083] Furthermore, in flow path C1, which serves as an increasing region, the cross-sectional area of ​​the flow path continuously increases towards the downstream side, thereby stabilizing the fluid flow and eliminating stagnation. Additionally, it can accelerate changes in the velocity and pressure of the fluid passing through flow path C1.

[0084] Furthermore, the CS valve 50 is composed of a CS valve seat 40a with an inclined cross-section and an abutment portion 51a of a CS valve core 51 with a curved cross-section. A flow path C1, serving as an increased region, is formed between the conical surface constituting the CS valve seat 40a and the abutment portion 51a of the CS valve core 51. Therefore, the flow of fluid through the CS valve 50 at the closed or throttling position of the CS valve core 51 can be directed tangentially (see reference). Figure 3 (The solid arrow) and stable.

[0085] In addition, the CS valve seat 40a is composed of a tapered surface with a straight cross-section and an inclined surface extending circumferentially. This allows the flow of fluid through the CS valve 50 at the closed or throttling position of the CS valve core 51, specifically the upstream side of flow path C1 and flow path C2, to be directed in the tangential direction and stabilized. Furthermore, it can guide the flow of fluid along the inclined surface, thus stabilizing the flow of fluid to a more downstream side of the CS valve 50.

[0086] In addition, the conical surface constituting the CS valve seat 40a can exist downstream of the normal line of the abutment portion 51a along the CS valve core 51. As a result, the fluid passing through the increased area will move forward in a straight line, making it difficult to obstruct the flow velocity of fluid approaching the speed of sound.

[0087] Furthermore, downstream of flow path C2, up to the opening of valve chamber 20 at port Ps 11, the cross-sectional area of ​​the flow path is constant, and the flow of fluid can be stabilized with the flow rate and pressure of the fluid passing through remaining approximately constant. Therefore, it is easy to stabilize the pressure of the fluid in valve chamber 20.

[0088] In addition, the flow path C1 can form an increased area by utilizing the conical surface of the CS valve seat 40a and the abutting part 51a of the CS valve core 51 in the CS valve 50, which is a lift valve, thus simplifying the structure of the capacity control valve V1.

[0089] In addition, the CS valve seat 40a is formed in the valve seat component 40, which is separate from the valve body 10, thus improving the machining accuracy of the tapered surface used to form the increased area.

[0090] Furthermore, in this embodiment 1, it was explained that in the flow path C2, which is continuous downstream of the flow path C1, the flow path cross-sectional area on the downstream side is kept constant by arranging the inner peripheral surface 10e of the valve housing 10 and the outer peripheral surface 51d of the CS valve core 51 parallel. However, it is not limited to this. The shapes of the inner peripheral surface 10e of the valve housing 10 and the outer peripheral surface 51d of the CS valve core 51 can also be changed to continuously form an increasing region on the downstream side of the flow path C2 where the flow path cross-sectional area tends to increase as it goes downstream (dA > 0).

[0091] [Example 2]

[0092] Reference Figures 6 to 8The 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.

[0093] like Figure 6 As shown, in the capacity control valve V2 of this embodiment 2, a Ps port 111, which serves as an outlet port, is formed on the valve housing 110. It extends radially and communicates with the suction chamber of the variable capacity compressor.

[0094] Additionally, a first recess 110a is formed on the axial left side of the valve housing 110. A flanged cylindrical valve seat component 140 is pressed into the first recess 110a from the axial left. Furthermore, a Pc port, serving as an inflow port, is formed on the valve housing 110 by pressing the fixed valve seat component 140 into the first recess 110a. This port communicates with the control chamber of the variable capacity compressor through a through hole 140b that axially penetrates the valve seat component 140.

[0095] Inside the valve housing 110, a valve chamber 120 is formed by a first recess 110a and a second recess 110b of a small diameter continuously formed to the axial right side of the first recess 110a. The abutment portion 51a of the CS valve core 51 is flexibly disposed within the valve chamber 120, allowing for free axial reciprocating movement. Furthermore, the Ps port 111 extends from the outer periphery of the valve housing 110 in the inner diameter direction and communicates with the valve chamber 120.

[0096] like Figure 7 As shown in (a), the first recess 110a of the valve housing 110 is formed such that its inner diameter R11 is larger than the inner diameter R12 of the second recess 110b (R11 > R12). Therefore, in the valve chamber 120, an annular stepped portion 114 is formed by the inner circumferential surface 110d of the first recess 110a, the bottom surface 110e extending axially to the right from the inner circumferential surface 110d of the first recess 110a in the inner diameter direction, and the inner circumferential surface 110f of the second recess 110b extending axially to the right from the inner diameter end of the bottom surface 110e of the first recess 110a. Furthermore, the annular stepped portion 114 is interrupted circumferentially at the position of the Ps port 111.

[0097] Furthermore, the opening on the valve chamber 120 side of the Ps port 111 is arranged in a stepped shape, axially spanning the inner peripheral surface 110d of the first recess 110a and the inner peripheral surface 110f of the second recess 110b. Additionally, the opening on the valve chamber 120 side communicates with the first recess 110a and the second recess 110b, and also opens axially to the left on the bottom surface 110e of the first recess 110a, communicating with the first recess 110a (see reference). Figure 7 (b)).

[0098] like Figure 7As shown in (a), the valve seat component 140 is cylindrical with a through hole 140b extending axially. A CS valve seat 140a, serving as a valve seat, is formed at the axial right end of the valve seat component 140. The CS valve seat 140a is formed from the outer diameter side to the inner diameter side with an inclined cross-section that gradually narrows towards the left axially, connecting to the annular flat surface 140c and the flat surface 140c from the inner diameter side. That is, the CS valve seat 140a is formed at the edge of the through hole 140b, which serves as a through flow path, and is composed of a tapered surface with a straight cross-section extending circumferentially.

[0099] Furthermore, a flange portion 140d is formed at the axial left end of the valve seat component 140, protruding from the outer peripheral surface in the outer diameter direction, and the side surface of the flange portion 140d on the axial right side abuts against the end face of the valve housing 110 on the axial left side (see reference). Figure 8 This allows for the specification of the insertion depth of the valve seat component 140 relative to the first recess 110a. At this time, the outer diameter end of the flat surface 140c is configured to be radially continuous with the inner circumferential surface of the Ps port 111, which opens into the inner circumferential surface 110d of the first recess 110a of the valve housing 110. Furthermore, the outer diameter end of the conical surface constituting the CS valve seat 140a is located on the outer diameter side of the second recess 110b of the valve housing 110. That is, the conical surface constituting the CS valve seat 140a extends to a position where it axially overlaps with the opening on the valve chamber 120 side of the Ps port 111.

[0100] Thus, through the flow path C101 formed between the conical surface of the CS valve seat 140a constituting the valve seat component 140 and the abutment portion 51a of the CS valve core 51, the flow path C102 formed between the conical surface of the CS valve seat 140a constituting the valve seat component 140 and the outer peripheral surface 51d of the large diameter portion 51b of the CS valve core 51, and the flow path 103 formed between the flat surface 140c of the valve seat component 140 and the bottom surface 110e of the first recess 110a constituting the stepped portion 114, a flow path extending to the downstream side of the stepped opening of the CS valve 50 extending to the valve chamber 120 side of the Ps port 111 is formed (see reference). Figure 8 ).also, Figure 8 This shows the state in which the CS valve core 51 is throttled to a position near the closed position during normal control of the capacity control valve V2.

[0101] In this embodiment 2, the flow path C101 forms an increased region as follows: the cross-sectional area A102 of the flow path between the outer diameter end of the conical surface constituting the CS valve seat 140a and the abutment portion 51a of the CS valve core 51 is larger than the cross-sectional area A101 between the inner diameter end of the conical surface constituting the CS valve seat 140a and the abutment portion 51a of the CS valve core 51 (A101 < A102), and the cross-sectional area of ​​the flow path tends to increase as it moves downstream (dA > 0). In addition, the flow path C102 constitutes an increased region as follows: by making the outer diameter portion of the conical surface constituting the CS valve seat 140a extend in a straight line to a position where it overlaps axially with the opening on the valve chamber 120 side of the Ps port 111, the flow path cross-sectional area A103 on the upstream side of the flow path C102 is larger than the flow path cross-sectional area A102 on the downstream side of the flow path C101 (A102 < A103), and the flow path cross-sectional area tends to increase as it goes downstream (dA > 0).

[0102] Furthermore, the cross-sectional area of ​​flow path C101 increases continuously as it moves downstream. Additionally, although the cross-sectional area of ​​flow path C102 also increases continuously as it moves downstream, the increase in cross-sectional area is greater than that of flow path C101 because the outer peripheral surface 51d of the CS valve core 51 extends linearly along the axial direction relative to the conical surface constituting the CS valve seat 140a.

[0103] In addition, the flow path C103 corresponds to the space of the outer diameter portion of the first recess 110a, and is connected to the stepped opening on the valve chamber 120 side of the Ps port 111 on the inner circumferential surface 110d and bottom surface 110e of the first recess 110a.

[0104] In addition, such as Figure 6 As shown, the conical surface constituting the CS valve seat 140a is located throughout the entire stroke of the abutment portion 51a of the CS valve core 51.

[0105] Therefore, in the capacity control valve V2 of this embodiment 2, flow paths C101 and C102 are provided in the flow path downstream of the CS valve 50, forming an increasing region where the cross-sectional area of ​​the flow path tends to increase as it goes downstream (dA > 0). When the fluid passing through the CS valve 50 is a supersonic flow (M > 1), the fluid passing through flow paths C101 and C102 will have an increased velocity and decreased pressure, exerting a force in the opening direction on the CS valve core 51. This suppresses the influence of the pressure of the fluid upstream of the CS valve 50, specifically the discharge pressure Pd in ​​this embodiment, on the downstream pressure of the CS valve 50. Thus, the influence of the discharge pressure Pd on the force generated by the back pressure acting on the CS valve core 51 can be suppressed, the deviation of the stroke of the CS valve core 51 from the current value input to the solenoid 80 can be suppressed, and the opening degree of the CS valve 50 can be adjusted with high precision.

[0106] Furthermore, when the fluid flowing through CS valve 50 is subsonic (M < 1), the fluid velocity decreases and the pressure increases through flow paths C101 and C102, exerting a force on CS valve core 51 in the valve-closing direction. Additionally, the force generated by the back pressure acting on CS valve core 51, influenced by the discharge pressure Pd, can be further increased. Therefore, the valve-closing characteristics of CS valve 50 can be improved, allowing CS valve 50 to close with a smaller current value.

[0107] In this way, flow paths C101 and C102 are provided in the flow path on the downstream side of CS valve 50, which are increasing regions whose cross-sectional area increases as they go downstream (dA > 0). By appropriately controlling the downstream pressure of CS valve 50 according to the flow rate of the fluid passing through CS valve 50, the controllability of CS valve 50 can be improved.

[0108] Furthermore, since the CS valve seat 140a, which constitutes the flow paths C101 and C102 as the increased region, is composed of a conical surface whose outer diameter extends linearly to a position where it overlaps axially with the opening on the valve chamber 120 side of the Ps port 111, it is easy to guide the fluid into the Ps port 111 while accelerating changes in the fluid velocity and pressure. As a result, the flow of fluid in the downstream flow path of the CS valve 50 can be stabilized and stagnation can be eliminated, making the downstream pressure of the CS valve 50, i.e., the pressure of the fluid in the valve chamber 120, more stable.

[0109] Furthermore, since the CS valve seat 140a is formed in the valve seat component 40, which is separate from the valve housing 10, the machining accuracy of the tapered surface used to form the increased area can be improved. Consequently, the tapered surface constituting the CS valve seat 140a can be extended to the vicinity of the Ps port 111.

[0110] Furthermore, in this embodiment 2, the valve seat component 140 may not have a flat surface 140c, and the conical surface constituting the CS valve seat 140a may be continuous with the outer peripheral surface of the valve seat component 140. In addition, in this case, the outer diameter end of the conical surface constituting the CS valve seat 140a is continuous with the opening on the valve chamber 120 side of the Ps port 111, so the annular stepped portion 114 may not be formed on the inner peripheral surface of the valve housing 110.

[0111] 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.

[0112] For example, in the above embodiments, the valve body and valve seat components are described as being made of metallic materials, but this is not a limitation. As long as the hardness of the valve seat component is greater than the hardness of the inner flow path side of the valve body, it can also be formed of resin materials or the like. In addition, in this case, the valve seat component is preferably formed of a different material than the valve core.

[0113] In addition, the contact portion between the CS valve core and the CS valve seat may not be formed as a curved cross-section.

[0114] In addition, the conical surface constituting the CS valve seat is not limited to a straight line, but can also be an arc.

[0115] In addition, the increased area is not limited to the area where the flow path cross-sectional area increases continuously through the conical surface, but can also be the area where the flow path cross-sectional area increases in stages through the stepped surface.

[0116] Furthermore, in the above embodiments 1 and 2, it was described that the continuous flow paths C1, C2 or flow paths C101, C102 on the downstream side of the CS valve 50 all constitute an increased region, but it is not limited to this. As long as any one of the upstream flow paths C1, C101 or the downstream flow paths C2, C102 constitutes an increased region, it is acceptable.

[0117] Furthermore, the capacity control valve of the above embodiment was described using the CS valve as an example of a lift valve, but the lift valve can also be a DC valve that opens and closes the flow path between the Pd port as the inflow port and the Pc port as the outflow port.

[0118] Symbol Explanation

[0119] 9: Fixed throttling orifice; 10: Valve body; 10a: Recess; 10b: Receiving part; 10c: Guide hole; 10d: Recess; 10e: Inner peripheral surface; 11: Ps port (outlet port); 20: Valve chamber; 21: Through hole; 30: Pressure working valve; 40: Valve seat assembly; 40a: CS valve seat (valve seat); 40b: Through hole (through flow path, inlet port); 40c: Flat surface; 50: CS valve (lift valve); 51: CS valve core (valve core); 51a: Abutment part; 51d: Outer peripheral surface; 80: Solenoid (drive source); 110: Valve body; 110a: First recess; 11 0b: Second recess; 110d: Inner circumferential surface; 110e: Bottom surface; 110f: Inner circumferential surface; 111: Ps port (outflow port); 114: Stepped portion; 120: Valve chamber; 140: Valve seat component; 140a: CS valve seat (valve seat); 140b: Through hole (through flow path, inflow port); 140c: Flat surface; 140d: Flange portion; C1, C2: Flow path (increased area, downstream flow path); C101, C102: Flow path (increased area, downstream flow path); C103: Flow path (downstream flow path); S: Space; V1, V2: Capacity control valve (valve).

Claims

1. A valve comprising: The valve body has an inlet port and an outlet port; The valve core has a contact portion and is driven by a drive source; a spring that exerts a force on the spool in a direction opposite to a driving direction of the driving source; as well as A lift valve, comprising a valve seat formed at the edge of a flow path and a contact portion of the valve core, controls the flow rate by moving the valve core. The valve seat is composed of a conical surface. In the cross-sectional view of the valve core, the contact portion of the valve core has a curved shape; The conical surface of the valve seat and the curved surface of the contact portion of the valve core together form a flow path extending from the upstream edge of the conical surface to the downstream edge of the conical surface. This flow path has an increasing region in which the cross-sectional area of ​​the flow path tends to increase towards the downstream side. The valve seat is formed in a valve seat component that is separate from the valve housing; The valve seat component is inserted into the recess of the valve housing along the opening direction of the valve core and pressed and fixed onto the valve housing; The conical surface forming the valve seat intersects with the inner circumferential surface of the outlet port, or the inner circumferential surface of the valve body that intersects with the inner circumferential surface of the outlet port, thereby being continuous with the opening of the outlet port. The inner circumferential surface of the valve housing is constructed such that the cross-sectional area of ​​the flow path between the inner circumferential surface of the valve housing and the valve core remains constant, or tends to increase towards the downstream side.

2. The valve according to claim 1, wherein, The cross-sectional area of ​​the flow path in the increased region increases continuously.

3. The valve according to claim 1, wherein, The conical surface is straight.

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