valve

Abstract

The present application provides a valve with high controllability. The valve (V1) is provided with: a valve housing (10) formed with an inflow port (40b) and an outflow port (11); a valve core (51) driven by a driving source (80); a spring (85) applying force to the valve core (51) in a direction opposite to the driving direction of the driving source (80); and a poppet valve (50) composed of a valve seat (40a) formed on the edge of the through flow path (40b) and the valve core (51), the valve (V1) controlling the flow rate through the movement of the valve core (51), wherein a reduction region with a flow path cross-sectional area showing a decreasing trend toward the downstream side is provided in the flow path (C1) on the downstream side of the poppet valve (50).

Description

TECHNICAL FIELD

[0001] The present application relates to a valve for variably controlling a working fluid, for example, to a valve for controlling the discharge amount of a variable displacement compressor used in an air conditioning system of an automobile according to pressure. BACKGROUND

[0002] A variable displacement compressor used in an air conditioning system of an automobile or the like has a rotary shaft that is rotationally driven by an engine, a swash plate that is variably linked to the rotary shaft at an inclination angle, and a compression piston or the like that is linked to the swash plate. The variable displacement compressor controls the discharge amount of a fluid by changing the inclination angle of the swash plate, thereby changing the stroke amount of the piston. A capacity control valve that is driven to be opened and closed by electromagnetic force is used, and the suction pressure Ps of a suction chamber that sucks a fluid, the discharge pressure Pd of a discharge chamber that discharges a fluid pressurized by the piston, and the control pressure Pc of a control chamber that accommodates the swash plate are used, and the pressure in the control chamber is appropriately controlled, whereby the inclination angle of the swash plate can be continuously changed.

[0003] In the continuous driving of the variable displacement compressor, the capacity control valve is normally controlled as follows: energization control is performed by a control computer, the electromagnetic force generated by a solenoid is used to move a valve element in the axial direction, and a valve provided between a discharge port through which the discharge fluid of the discharge pressure Pd passes and a control port through which the control fluid of the control pressure Pc passes is opened and closed to adjust the control pressure Pc of the control chamber of the variable displacement compressor.

[0004] In the normal control of the capacity control valve, the pressure of the control chamber of the variable displacement compressor is appropriately controlled, and the inclination angle of the swash plate with respect to the rotary shaft is continuously changed, thereby changing the stroke amount of the piston to control the discharge amount of the fluid with respect to the discharge chamber, and the air conditioning system is adjusted to a target refrigeration capacity.

[0005] In addition, the capacity control valve also has a case in which a poppet valve provided between the control port and the suction port is opened and closed to control the flow rate of the fluid flowing from the control port to the suction port (see Patent Document 1). Such a capacity control valve controls the control pressure Pc in the control chamber of the variable displacement compressor using the pressure difference between the control pressure Pc and the suction pressure Ps that is lower than the control pressure Pc. Furthermore, the control chamber of the variable displacement compressor communicates with the discharge chamber of the variable displacement compressor via an orifice, and the high-pressure discharge pressure Pd is constantly supplied to the control chamber through the orifice, thereby adjusting the control pressure Pc.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT DOCUMENTS

[0008] Patent Document 1: Japanese Patent Application Publication No. 2015-075054 (pages 8 to 10, FIG. 1)Figure 2 ) SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] The capacity control valve of Patent Literature 1, as an object to control the flow rate of fluid by opening and closing of the poppet valve, utilizes the pressure difference between the control pressure Pc lower than the discharge pressure Pd and the suction pressure Ps, and thus, it is possible to reduce the flow rate of fluid passing through the poppet valve, but under the influence of the discharge pressure Pd continuously supplied through the orifice in order to adjust the control pressure Pc, even if a predetermined current is input to the solenoid, the stroke of the valve core can sometimes be deviated, and the opening degree of the valve can deviate from the target value. According to the inventors' research, it was clarified that the flow rate of refrigerant close to the speed of sound passing through the poppet valve can affect the stroke of the valve core, and by utilizing this, the above-mentioned deviation can be suppressed.

[0011] The present invention has been achieved in view of such problems, and an object thereof is to provide a valve with high controllability.

[0012] MEANS FOR SOLVING THE PROBLEMS

[0013] In order to solve the above-mentioned problems, the valve of the present invention is provided with:

[0014] a valve housing formed with an inflow port and an outflow port;

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

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

[0017] a poppet valve composed of a valve seat formed on the edge of the through flow path and the valve core, which controls the flow rate by movement of the valve core, wherein

[0018] a reduction region in which the flow path cross-sectional area tends to decrease toward the downstream side is provided in the flow path on the downstream side of the poppet valve.

[0019] Thereby, when the fluid passing through the poppet valve is a supersonic flow, the flow rate of the fluid passing through the reduction region in the flow path on the downstream side of the poppet valve decreases, and the downstream pressure of the poppet valve rises. Thereby, a force in the direction of closing the valve acts on the valve core, and the closing valve characteristic improves, and it is possible to close the poppet valve with a small current value. In addition, when the fluid passing through the poppet valve is a subsonic flow, the flow rate of the fluid passing through the reduction region in the flow path on the downstream side of the poppet valve rises, and the downstream pressure of the poppet valve decreases. Thereby, a force in the direction of opening the valve acts on the valve core, and it is possible to suppress the influence of the pressure of the fluid on the upstream side on the force generated by the back pressure acting on the valve core, and suppress the deviation of the stroke of the valve core with respect to the current value input to the solenoid. Thereby, it is possible to adjust the opening degree of the poppet valve with high precision.

[0020] Also, in the reduction region, the minimum flow passage cross-sectional area can be constant regardless of the stroke of the spool.

[0021] Thus, the pressure of the fluid passing through the reduction region after the valve chamber can be stabilized at all times.

[0022] Also, the flow passage cross-sectional area of the reduction region can be continuously reduced.

[0023] Thus, the flow of the fluid passing through the reduction region in the flow passage on the downstream side of the poppet valve can be stabilized and stagnation can be eliminated.

[0024] Also, the poppet valve can be composed of the valve seat of the inclined cross-sectional shape and the spool of the curved cross-sectional shape.

[0025] Thus, the flow of the fluid passing through the poppet valve at the closed position or the throttling position of the spool can be stabilized toward the tangential direction.

[0026] Also, the inclined shape can be linear.

[0027] Thus, the flow of the fluid passing through the poppet valve at the closed position or the throttling position of the spool can be more stabilized toward the tangential direction.

[0028] Also, the inclined surface constituting the valve seat can be continuous with the inclined surface constituting the reduction region.

[0029] Thus, it is easy to form a larger flow passage cross-sectional area on the upstream side of the reduction region.

[0030] Also, the inclined surface constituting the valve seat can be formed in a valve seat member separate from the valve housing, and the inclined surface constituting the reduction region can be formed in the valve housing.

[0031] Thus, it is easy to set the flow passage cross-sectional area, and it is easy to form the reduction region. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a cross-sectional view showing a case where the CS valve is opened in an unenergized state of the capacity control valve of Embodiment 1 of the present application;

[0033] Figure 2 is a cross-sectional view showing a case where the valve seat member is pressed into the valve housing of the capacity control valve of Embodiment 1;

[0034] Figure 3 is an enlarged cross-sectional view showing the reduction region in the flow passage on the downstream side of the CS valve in an energized state (at the time of normal control) of the capacity control valve of Embodiment 1;

[0035] Figure 4(a) is a diagram schematically illustrating the valve-closing characteristics of the capacity control valve of Example 1, where the flow path cross-sectional area tends to decrease, in supersonic flow. Figure 4 (b) is a diagram schematically showing the closed-valve characteristics of a comparative example with a constant flow path cross-sectional area;

[0036] Figure 5 (a) is a diagram schematically illustrating the valve-closing characteristics of the capacity control valve of Example 1, where the flow path cross-sectional area tends to decrease, in subsonic flow. Figure 5 (b) is a diagram schematically showing the closed-valve characteristics of a comparative example with a constant flow path cross-sectional area;

[0037] Figure 6 This is a cross-sectional view showing the CS valve open in the un-energized state of the capacity control valve in Embodiment 2 of the present invention;

[0038] Figure 7 This is a cross-sectional view showing the valve seat component being pressed into the valve housing of the capacity control valve of Embodiment 2;

[0039] Figure 8 This is an enlarged cross-sectional view showing the reduced region in the flow path on the downstream side of the CS valve when the capacity control valve of Embodiment 2 is energized (under normal control). Detailed Implementation

[0040] 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.

[0041] [Example 1]

[0042] 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.

[0043] 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.

[0044] First, the variable displacement compressor will be described. The variable displacement compressor has a casing having a discharge chamber, a suction chamber, a control chamber, and a plurality of cylinders. Further, a communication passage directly communicating the discharge chamber and the control chamber is provided in the variable displacement compressor, and a fixed orifice 9 for adjusting the pressure balance between the discharge chamber and the control chamber is provided in the communication passage (see Figure 1 ).

[0045] Further, the variable displacement compressor has a rotary shaft, a swash plate, and a plurality of pistons. The rotary shaft is rotationally driven by an engine (not shown) provided outside the casing. The swash plate is linked to the rotary shaft so as to be tiltable within the control chamber by a hinge mechanism. The plurality of pistons are linked to the swash plate and are fitted in the respective cylinders so as to be movable reciprocally. By using a capacity control valve VI which is driven to be opened and closed by electromagnetic force, the suction pressure Ps of the suction chamber using the suction fluid, the discharge pressure Pd of the discharge chamber discharging the fluid pressurized by the pistons, and the control pressure Pc of the control chamber in which the swash plate is accommodated, and by appropriately controlling the pressure in the control chamber to continuously change the tilt angle of the swash plate, the stroke amount of the pistons is changed to control the discharge amount of the fluid.

[0046] As shown in Figure 1 , the capacity control valve VI of the present embodiment 1 assembled in the variable displacement compressor adjusts the current applied to the coil 86 constituting a solenoid 80 as a driving source to open and close the CS valve 50 as a poppet valve of the capacity control valve VI. Thereby, the control pressure Pc in the control chamber is variably controlled by controlling the fluid flowing from the control chamber to the suction chamber. Further, the discharge fluid of the discharge pressure Pd of the discharge chamber is constantly supplied to the control chamber via the fixed orifice 9, and the control pressure Pc in the control chamber is increased by closing the CS valve 50 of the capacity control valve VI.

[0047] In the capacity control valve VI of the present embodiment 1, the CS valve 50 is constituted by a CS valve spool 51 as a valve element and a CS valve seat 40a as a valve seat. The CS valve seat 40a is formed in a cylindrical valve seat member 40 which is press-fitted into a recess 10a of a valve housing 10. The CS valve 50 is opened and closed by bringing an abutting portion 51a formed in the axial left end of the CS valve spool 51 into contact with or separation from the CS valve seat 40a in the axial direction.

[0048] Next, the structure of the capacity control valve VI will be described. As shown in Figure 1 , the capacity control valve VI is mainly constituted by the valve housing 10, the valve seat member 40, the CS valve spool 51, and the solenoid 80. The valve housing 10 and the valve seat member 40 are formed of a metal material. The CS valve spool 51 is disposed in the valve housing 10 so as to be movable reciprocally in the axial direction. The solenoid 80 is connected to the valve housing 10 to apply a driving force to the CS valve spool 51.

[0049] like Figure 1 As shown, the CS valve core 51 is formed of metal or resin material. Furthermore, the CS valve core 51 consists of a large-diameter portion 51b and a small-diameter portion 51c. The large-diameter portion 51b is a cylindrical 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. Additionally, the CS valve core 51 also serves as a rod through which the coil 86 of the solenoid 80 passes.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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. A cylindrical valve seat member 40 is pressed into the recess 10a 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.

[0054] 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.

[0055] 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.

[0056] Additionally, a guide hole 10c is formed on the inner circumferential surface of the valve housing 10. In the guide hole 10c, on the axial right side relative to the mounting solenoid 80 of the valve chamber 20, the outer circumferential surface 51d of the large-diameter portion 51b of the CS valve core 51 can slide within it (see reference). Figure 3 Furthermore, 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, allowing the CS valve core 51 to move smoothly relative to the valve housing 10 in the axial direction.

[0057] 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.

[0058] 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, and the flange portion 82d of the central column 82 is inserted and fixed therein in a substantially sealing manner from the axial right side. Furthermore, the outer casing 81 is inserted and fixed therein in a substantially sealing manner from its axial right side, thereby integrally connecting them.

[0059] Thus, with the valve housing 10, the central column 82, and the outer casing 81 integrally connected, the axial right end face of the valve housing 10 and the axial right side surface 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 casing 81. Furthermore, a gap is formed between the bottom surface of the recess 10d of the valve housing 10 and the axial left end face of the central column 82, which are axially separated.

[0060] Further, a through-hole 21 is formed in the valve housing 10. The through-hole 21 extends in the axial direction between the end surface on the left side in the axial direction of the valve housing 10 and the bottom of the recessed portion 10d. The through-hole 21 is composed of a small-diameter hole portion 211 and a large-diameter hole portion 212. The axial left end of the small-diameter hole portion 211 communicates with the control chamber of the variable displacement compressor. The large-diameter hole portion 212 continuously extends from the axial right end of the small-diameter hole portion 211 and has a larger diameter than the small-diameter hole portion 211. The axial right end of the large-diameter hole portion 212 is open to the gap formed between the bottom surface of the recessed portion 10d and the end surface on the left side in the axial direction of the center column 82. Further, the control fluid of the control pressure Pc is supplied from the control chamber of the variable displacement compressor in the small-diameter hole portion 211 of the through-hole 21 and in the through-hole 40b of the valve seat member 40.

[0061] In the large-diameter hole portion 212 of the through-hole 21, a ball-shaped operation valve spool 31 and a return spring 32 whose axial right end is fixed to the end surface on the left side in the axial direction of the center column 82 and whose axial left end abuts against the operation valve spool 31 from the right side in the axial direction are disposed. The operation valve spool 31 is urged by the return spring 32 to the left side in the axial direction. These operation valve spool 31 and return spring 32 constitute a pressure operation valve 30 that controls the communication between the control chamber of the variable displacement compressor and the space S inside the housing 81 in the through-hole 21.

[0062] For the sake of convenience in explanation, the illustration is omitted, but in the case where the control pressure Pc is high, the operation valve spool 31 of the pressure operation valve 30 moves to the right side in the axial direction against the force of the return spring 32 and the pressure of the fluid in the space S inside the housing 81, and separates from the valve seat 213 of the cross-section inclined shape formed in the connecting portion of the axial right end of the small-diameter hole portion 211 and the axial left end of the large-diameter hole portion 212 of the through-hole 21, so that the pressure operation valve 30 opens. Thereby, the control chamber of the variable displacement compressor and the space S inside the housing 81 communicate via the through-hole 21, the control fluid of the control pressure Pc is supplied from the control chamber of the variable displacement compressor to the space S inside the housing 81 via 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 member 40 becomes small, the CS valve spool 51 can be smoothly operated to the left side in the axial direction, i.e., the valve closing direction, and the responsiveness of the control at the time of high output of the variable displacement compressor can be improved.

[0063] Further, in the valve housing 10, the slight gap between the inner peripheral surface of the guide hole 10c and the outer peripheral surface of the large-diameter portion 51b of the CS valve spool 51 functions as a throttle, whereby the fluid in the space S inside the housing 81 can be slowly released to the Ps port 11, and in the case of long time non-use, the pressure difference between the fluid in the valve chamber 20 and the fluid in the space S inside the housing 81 is maintained to be small.

[0064] Here, the valve seat member 40 will be described. As shown in Figure 2 the valve housing 10. Also, the valve seat member 40 is formed of a different raw material from the CS spool 51.

[0065] Also, the valve seat member 40 is formed in a cylindrical shape with a through-hole 40b that penetrates in the axial direction. At the axial right end of the valve seat member 40, a CS valve seat 40a of a cross-sectionally inclined shape is formed from the outer diameter side to the inner diameter side, and is connected from the inner diameter side to an annular flat surface 40c and a flat surface 40c that gradually narrows in diameter toward the axial left side. That is, the CS valve seat 40a is formed at the edge of the through-hole 40b that is a through-flow path, and is composed of a tapered surface that extends in the circumferential direction with a cross-sectionally straight inclined surface.

[0066] Also, by bringing the flat surface 40c on the axial right side of the valve seat member 40 into abutment with the receiving portion 10b formed by the bottom surface of the recess 10a in the axial direction (see Figure 3 ), the progress of insertion of the valve seat member 40 with respect to the recess 10a can be regulated, and the sealability between the valve housing 10 and the valve seat member 40 is improved. At this time, the outer diameter end of the tapered surface that constitutes the CS valve seat 40a is disposed so as to be connected to the axial left end of the inner peripheral surface 10e of the valve chamber 20 of the valve housing 10.

[0067] Thus, by the flow path C1 formed between the tapered surface that constitutes the CS valve seat 40a of the valve seat member 40 and the abutment portion 51a of the CS spool 51, the flow path C2 formed between the tapered surface that constitutes the CS valve seat 40a and the outer peripheral surface 51d of the large diameter portion 51b of the CS spool 51, and 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 spool 51, a flow path on the downstream side of the CS valve 50 that extends to the opening of the valve chamber 20 side of the Ps port 11 is formed (see Figure 3 ). Also, Figure 3 a state in which the CS spool 51 is caused to perform stroke to the vicinity of the closed position under normal control of the capacity control valve V1 is shown.

[0068] In this embodiment 1, the flow path C1 constitutes a decreasing region in which the flow path cross-sectional area A2 between the tapered surface that constitutes the CS valve seat 40a and the outer diameter end of the abutment portion 51a of the CS spool 51 is smaller than the flow path cross-sectional area Al between the inner diameter end of the tapered surface that constitutes the CS valve seat 40a and the abutment portion 51a of the CS spool 51 (Al > A2), and the flow path cross-sectional area has a decreasing tendency (dA < 0) as it goes to the downstream side. Also, in the flow path C2, the flow path cross-sectional area A3 is made constant by disposing the inner peripheral surface 10e of the valve housing 10 and the outer peripheral surface 51d of the CS spool 51 in parallel. Also, when the CS spool 51 is caused to perform stroke to the throttle position under normal control of the capacity control valve V1, the flow path cross-sectional area A2 of the flow path C1 is smaller than the flow path cross-sectional area Al of the flow path C1, and the flow path cross-sectional area A3 of the flow path C2 is constant. Figure 3The flow passage cross-sectional area A2 on the downstream side of the flow passage C1 is the same as the flow passage cross-sectional area A3 of the flow passage C2 (A2=A3), but is not limited thereto, and the flow passage cross-sectional area A3 on the upstream side of the flow passage C2 can be smaller than the flow passage cross-sectional area A2 on the downstream side of the flow passage C1 (A2>A3).

[0069] Further, the reduction region is formed in the flow passage on the downstream side of the CS valve 50 within the stroke range of the abutment portion 51a of the CS spool 51.

[0070] Further, the flow passage cross-sectional area of the flow passage C1 continuously decreases toward the downstream side.

[0071] Next, the changes in the flow rate and pressure of the fluid passing through the flow passages C1, C2 on the downstream side of the CS valve 50 are described. Further, a case where the control pressure Pc is controlled within a range that maintains the above-described pressure working valve 30 closed is described. Regarding the influence of the area change in isentropic flow, the following shows a relationship between the cross-sectional area and the pressure.

[0072] [Formula 1]

[0073]

[0074] p: pressure

[0075] γ: specific heat ratio

[0076] M: Mach number

[0077] A: area

[0078] Based on the relationship between the cross-sectional area and the pressure, when the pressure difference between the control pressure Pc within the through-hole 40b of the valve seat member 40 and the suction pressure Ps within 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 the flow passage C1, which constitutes a reduction region in which the flow passage cross-sectional area tends to decrease toward the downstream side (dA<0) in the flow passage on the downstream side of the CS valve 50, decreases in flow rate and increases in pressure. Further, since the fluid passes through the flow passage C2, which is continuous to the downstream of the flow passage C1 and has a constant flow passage cross-sectional area, the fluid stably flows at approximately constant flow rate and pressure and flows into the Ps port 11 (refer to Figure 3 ).

[0079] On the other hand, when the Pc-Ps differential pressure is small and the fluid passing through the CS valve 50 is a subsonic flow (M<1), the fluid passing through the flow passage C1, which constitutes a reduction region on the downstream side of the CS valve 50, increases in flow rate and decreases in pressure. Further, since the fluid passes through the flow passage C2, which is continuous to the downstream of the flow passage C1 and has a constant flow passage cross-sectional area, the fluid stably flows at approximately constant flow rate and pressure and flows into the Ps port 11 (refer to Figure 3).

[0080] In addition, the downstream pressure of the CS valve 50, that is, the pressure of the fluid in the valve chamber 20 is easily affected by the discharge pressure Pd that is constantly supplied via the fixed throttle hole 9 (refer to Figure 1 ) in order to adjust the control pressure Pc in the control chamber of the variable capacity compressor, and thus it is difficult for the pressure to decrease compared to that in the Ps port 11.

[0081] In the present embodiment 1, as described above, the fluid flows through the reduction region at a supersonic speed, whereby, in addition to the influence of the discharge pressure Pd, the downstream pressure of the CS valve 50 can be increased, and thus the pressure of the fluid in the space S inside the housing 81 that changes based on the pressure difference with the pressure of the fluid in the valve chamber 20, that is, the force generated by the back pressure acting on the CS spool 51 can be further increased (refer to Figure 1 ). In addition, the fluid flows through the reduction region at a subsonic speed, whereby the downstream pressure of the CS valve 50 can be decreased, and thus the influence of the discharge pressure Pd on the pressure of the fluid in the space S inside the housing 81 that changes based on the pressure difference with the pressure of the fluid in the valve chamber 20, that is, the force generated by the back pressure acting on the CS spool 51 can be suppressed.

[0082] As described above, in the capacity control valve V1 of the present embodiment 1, the flow path C1 that is a reduction region in which the flow path cross-sectional area has a decreasing tendency (dA < 0) toward the downstream side is provided in the flow path on the downstream side of the CS valve 50. When the fluid passing through the CS valve 50 flows at a supersonic speed (M > 1), the fluid passing through the flow path C1 decreases in flow speed and increases in pressure, and a force in the closing direction acts on the CS spool 51. In addition, the force generated by the back pressure acting on the CS spool 51 that is affected by the discharge pressure Pd can be further increased. As shown in Figure 4 (a), the closing characteristics of the CS valve 50 can be improved, and the CS valve 50 can be closed with a smaller current value. In addition, as shown in Figure 4 (b), in a reference graph showing the characteristics of a flow path in which the flow path cross-sectional area (dA = constant) is constant, the CS valve 50 cannot be closed when the discharge pressure Pd is high, in other words, a large current is required to close the CS valve 50.

[0083] In addition, when the fluid passing through the CS valve 50 flows at a subsonic speed (M < 1), the fluid passing through the flow path C1 increases in flow speed and decreases in pressure, and a force in the opening direction acts on the CS spool 51. As a result, as shown in Figure 5 (a), the influence of the pressure of the fluid on the upstream side of the CS valve 50, which is the discharge pressure Pd in the present embodiment, on the downstream pressure of the CS valve 50 can be suppressed. In addition, as shown in Figure 5In the reference diagram showing the characteristics of the flow path in which the flow path cross-sectional area (dA=constant) is constant, the deviation of the drive current becomes large. Thus, it is possible to suppress the influence of the discharge pressure Pd on the force generated by the back pressure acting on the CS spool 51, suppress the deviation of the stroke of the CS spool 51 with respect to the current value input to the solenoid 80, and adjust the opening degree of the CS valve 50 with high precision.

[0084] Thus, the flow path Cl that is a reduction region in which the flow path cross-sectional area has a decreasing tendency (dA<0) toward the downstream side is provided in the flow path on the downstream side of the CS valve 50, and by appropriately controlling the downstream pressure of the CS valve 50 in accordance with the flow rate of the fluid passing through the CS valve 50, it is possible to improve the controllability of the CS valve 50.

[0085] In addition, in the flow path Cl that is a reduction region, the flow path cross-sectional area continuously decreases toward the downstream side, and thus it is possible to stabilize the flow of the fluid and eliminate stagnation. In addition, it is possible to accelerate the change in the flow rate and pressure of the fluid passing through the flow path Cl.

[0086] In addition, the CS valve 50 is constituted by the abutting portion 51a of the CS spool 51 having a curved surface shape and the CS valve seat 40a having a tapered surface shape in which the cross section is inclined, and the flow path Cl that is a reduction region is formed between the tapered surface constituting the CS valve seat 40a and the abutting portion 51a of the CS spool 51, and thus it is possible to stabilize the flow of the fluid passing through the CS valve 50 toward the tangential direction (refer to the solid arrow) at the closed position or the throttling position of the CS spool 51. Figure 3

[0087] In addition, the CS valve seat 40a is constituted by a tapered surface in which the cross section is a straight line and which extends in the circumferential direction, and it is possible to stabilize the flow of the fluid passing through the CS valve 50, specifically the flow of the fluid in the flow path Cl, toward the tangential direction at the closed position or the throttling position of the CS spool 51, and it is possible to guide the flow of the fluid along the inclined surface, and thus it is possible to stabilize the flow of the fluid to the flow path C2 continuous to the downstream side.

[0088] In addition, the tapered surface constituting the CS valve seat 40a can exist on the downstream side of the normal line of the abutting portion 51a of the CS spool 51, and thus the fluid passing through the reduction region advances in a straight line, and thus it is difficult to hinder the flow rate of the fluid approaching the sonic speed.

[0089] In addition, in the flow path C2, the flow path cross-sectional area is constant until the opening of the valve chamber 20 side of the Ps port 11, and it is possible to stabilize the flow of the fluid in a state in which the flow rate and pressure of the fluid passing through are substantially constant, and thus it is easy to stabilize the pressure of the fluid in the valve chamber 20.

[0090] ​Further, the flow passage C1 can form the reduction region using the tapered surface that constitutes the CS valve seat 40a and the abutting portion 51a of the CS valve spool 51 in the CS valve that is a poppet valve, and thus the structure of the capacity control valve V1 can be simplified.

[0091] Further, the CS valve seat 40a is formed in the valve seat member 40 that is separate from the valve housing 10, and thus the machining precision of the tapered surface for forming the reduction region can be improved.

[0092] Further, in the present embodiment 1, the flow passage C2 that is continuous to the downstream of the flow passage C1 is described as a manner in which the inner peripheral surface 10e of the valve housing 10 and the outer peripheral surface 51d of the CS valve spool 51 are arranged in parallel to make the flow passage cross-sectional area constant, but is not limited thereto, and the shape of the inner peripheral surface 10e of the valve housing 10 and the outer peripheral surface 51d of the CS valve spool 51 can be changed to continuously constitute the reduction region in which the flow passage cross-sectional area has a decreasing tendency (dA < 0) toward the downstream side in the flow passage C2.

[0093] [Embodiment 2]

[0094] Reference Figures 6 to 8 The capacity control valve of the present embodiment 2 will be described. Further, the description of the same structure as that of the above-described embodiment 1 and the repeated description will be omitted.

[0095] As Figure 6 shown, in the capacity control valve V2 of the present embodiment 2, the Ps port 111 that is an outflow port is formed in the valve housing 110, penetrates in the radial direction, and communicates with the suction chamber of the variable displacement compressor.

[0096] Further, the recess 110a is formed in the axial left side of the valve housing 110. In the recess 110a, the cylindrical valve seat member 40 is pressed in from the axial left side. Further, in the valve housing 110, the Pc port that is an inflow port is formed by pressing the fixed valve seat member 140 in the recess 110a, and communicates with the control chamber of the variable displacement compressor through the penetration hole 140b of the valve seat member 140 that penetrates in the axial direction.

[0097] The valve chamber 120 is formed in the inside of the valve housing 110, and the abutting portion 51a of the CS valve spool 51 is arranged so as to be able to reciprocate in the axial direction in the valve chamber 120. Further, the Ps port 111 extends in the radial direction from the outer peripheral surface of the valve housing 110 toward the inner diameter direction, and communicates with the valve chamber 120. Further, the tapered surface 110e is formed in the valve chamber 120, is continuous to the axial left end of the opening of the valve chamber 120 side of the Ps port 111, and gradually expands in diameter toward the axial left side (see Figure 7 ).

[0098] As Figure 7As shown, the recess 110a of the valve housing 110 is formed such that its inner diameter R11 is larger than the inner diameter R12 of the left axial end of the conical surface 110e constituting the valve chamber 120 (R11 > R12). Thus, the bottom surface of the recess 110a forms a receiving portion 110b that can abut against the flat surface 140c on the right axial side of the valve seat component 140.

[0099] like Figure 7 As shown, the valve seat component 140 is cylindrical with a through hole 140b extending axially. At the axial right end of the valve seat component 140, a CS valve seat 140a, which is a valve seat with an inclined cross-section, is formed from the outer diameter side to the inner diameter side. It is connected to the annular flat surface 140c and the flat surface 140c from the inner diameter side and gradually narrows towards the left axial direction. 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 an inclined cross-section extending circumferentially.

[0100] Additionally, by axially contacting the flat surface 140c on the axial right side of the valve seat component 140 with the receiving portion 110b formed by the bottom surface of the recess 110a (see reference). Figure 8 This allows for the specification of the insertion progress of the valve seat component 140 relative to the recess 110a, and improves the sealing performance between the valve body 110 and the valve seat component 140. At this time, 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 conical surface 110e of the valve chamber 120 of the valve body 110.

[0101] 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 C102 formed between the conical surface 110e of the valve body 110 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 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.

[0102] In this Embodiment 2, in the flow path C101, the flow path cross-sectional area A101 between the inner diameter end of the tapered surface constituting the CS valve seat 140a and the abutting portion 51a of the CS spool 51 is substantially the same as the flow path cross-sectional area A102 between the tapered surface constituting the CS valve seat 140a and the outer diameter end of the abutting portion 51a of the CS spool 51 (A101 = A102), and the flow path cross-sectional area is substantially constant. In addition, the flow path C102 constitutes a decreasing region in which the flow path cross-sectional area A104 on the downstream side between the tapered surface 110e of the valve housing 110 and the abutting portion 51a of the CS spool 51 is smaller than the flow path cross-sectional area A103 on the upstream side (A103 > A104), and the flow path cross-sectional area has a decreasing tendency (dA < 0) as it goes to the downstream side.

[0103] In addition, the flow path cross-sectional area of the flow path C102 continuously decreases as it goes to the downstream side, and in the decreasing region, the flow path cross-sectional area A104, that is, the minimum flow path cross-sectional area, is constant regardless of the stroke of the CS spool 51.

[0104] Thus, in the capacity control valve V2 of this Embodiment 2, the flow path C102, which is a decreasing region in which the flow path cross-sectional area has a decreasing tendency (dA < 0) as it goes to the downstream side, is provided in the flow path on the downstream side of the CS valve 50. When the fluid passing through the CS valve 50 is a supersonic flow (M > 1), the fluid passing through the flow path C102 decreases in flow velocity and increases in pressure, and a force in the closing direction acts on the CS spool 51. In addition, the force generated by the back pressure acting on the CS spool 51, which is affected by the discharge pressure Pd, can be further increased. Thus, it is possible to improve the closing characteristics of the CS valve 50 and close the CS valve 50 with a smaller current value.

[0105] In addition, when the fluid passing through the CS valve 50 is a subsonic flow (M < 1), the fluid passing through the flow path C102 increases in flow velocity and decreases in pressure, and a force in the opening direction acts on the CS spool 51. Thus, it is possible to suppress the influence of the discharge pressure Pd on the downstream pressure of the CS valve 50. In this way, it is possible to suppress the influence of the discharge pressure Pd on the force generated by the back pressure acting on the CS spool 51, suppress the deviation of the stroke of the CS spool 51 with respect to the current value input to the solenoid 80, and accurately adjust the opening degree of the CS valve 50.

[0106] In this way, the flow path C102, which is a decreasing region in which the flow path cross-sectional area has a decreasing tendency (dA < 0) as it goes to the downstream side, is provided in the flow path on the downstream side of the CS valve 50, and by appropriately controlling the downstream pressure of the CS valve 50 in accordance with the flow velocity of the fluid passing through the CS valve 50, it is possible to improve the controllability of the CS valve 50.

[0107] Further, in the flow path C102 as the reduction region, the minimum flow path cross-sectional area is constant regardless of the stroke of the CS valve spool 51, so it is possible to stabilize the pressure of the fluid in the valve chamber 120 after passing through the reduction region.

[0108] Further, the tapered surface 110e of the valve housing 110 constituting the flow path C102 is configured as a tapered surface extending linearly in connection with the axial left end of the opening of the valve chamber 120 side of the Ps port 111, so it is easy to accelerate the change in the flow rate, pressure of the fluid while guiding into the Ps port 111. Thereby, it is possible to stabilize the flow of the fluid in the flow path downstream of the CS valve 50 and eliminate stagnation, making the downstream pressure of the CS valve 50, that is, the pressure of the fluid in the valve chamber 120 more stable.

[0109] Further, the flow path C101 having a constant flow path cross-sectional area is formed between the tapered surface constituting the CS valve seat 40a and the abutting portion 51a of the CS valve spool 51, wherein the CS valve seat 40a constitutes the CS valve 50, so it is possible to make the flow rate and pressure of the fluid passing through the CS valve 50 at the closed position or the throttling position of the CS valve spool 51 substantially constant, making the flow thereof toward the tangential direction (refer to the solid arrow in FIG. 1) and stable. Figure 8

[0110] Further, the tapered surface constituting the CS valve seat 40a is continuous with the tapered surface 110e of the valve housing 110 constituting the flow path C102 as the reduction region, so it is easy to form the continuous portion of the flow paths C101, C102, that is, the flow path cross-sectional area of the flow path C102 as the reduction region on the upstream side thereof to be large.

[0111] Further, the CS valve seat 140a is formed in the valve seat member 140 separate from the valve housing 110, and the tapered surface 110e constituting the reduction region is formed in the valve housing 110, so it is easy to set the flow path cross-sectional area in the flow paths C101, C102, and it is possible to easily form the reduction region.

[0112] Further, in the present embodiment 2, the structure in which the flow path cross-sectional area of the flow path C101 formed on the upstream side of the flow path C102 as the reduction region is constant is described, but it is not limited thereto, and the flow path cross-sectional area of the flow path C101 can have a tendency to increase toward the downstream side.

[0113] The above describes the embodiments of the present application with reference to the drawings, but the specific structure is not limited to these embodiments, and even if there are modifications, additions within the scope of the gist of the present application, they are included in the present application.

[0114] ​For example, in the above-described embodiment, a case where the valve housing and the valve seat member are made of a metal material is described, but is not limited thereto, and can be formed of a resin material or the like as long as the hardness of the valve seat member is greater than the hardness of the inner side of the flow path of the valve housing. In this case, the valve seat member is preferably formed of a different material from the valve core.

[0115] In addition, the abutting portion of the CS valve core and the CS valve seat can not be formed in a cross-sectional curved surface shape.

[0116] In addition, the tapered surface constituting the CS valve seat is not limited to a straight line shape, and can be a circular arc shape.

[0117] In addition, the reduction region is not limited to a region in which the flow path cross-sectional area is continuously reduced by a tapered surface, and can be a region in which the flow path cross-sectional area is reduced in stages by a stepped surface.

[0118] In addition, the above-described embodiment of the capacity control valve is described taking the CS valve as a poppet valve, but the poppet valve can be a DC valve that opens and closes the flow path between the Pd port as an inflow port and the Pc port as an outflow port.

[0119] Symbol Explanation

[0120] 9: fixed orifice; 10: valve housing; 10a: recess; 10b: receiving portion; 10c: guide hole; 10d: recess; 10e: inner peripheral surface; 11: Ps port (outflow port); 20: valve chamber; 21: through hole; 30: pressure-operated valve; 40: valve seat member; 40a: CS valve seat (valve seat); 40b: through hole (through flow path, inflow port); 40c: flat surface; 50: CS valve (poppet valve); 51: CS valve core (valve core); 51a: abutting portion; 51d: outer peripheral surface; 80: solenoid (drive source); 110: valve housing; 110e: tapered surface; 111: Ps port (outflow port); 120: valve chamber; 140: valve seat member; 140a: CS valve seat (valve seat); 140b: through hole (through flow path, inflow port); 140c: flat surface; C1, C102: flow path (reduction region, downstream side flow path); C2, C101: flow path (downstream side flow path); S: space; V1, V2: capacity control valve (valve).

Claims

1. A valve comprising: a valve housing formed with an inflow port and an outflow port; a valve core driven by a drive source; a spring applying force to the valve core in a direction opposite to a driving direction of the drive source; and a poppet valve constituted by a valve seat formed at an edge of a through flow path and a contact portion of the valve core which contacts and separates from the valve seat in an axial direction, the valve controlling a flow rate by movement of the valve core, wherein the valve seat is formed by an inclined surface inclined with respect to the axial direction, the contact portion of the valve core has a cross-sectional curved surface shape, the valve housing is provided with an inner peripheral surface formed continuously with a downstream side edge of the inclined surface and extending toward the downstream side, a reduction region in which a flow path cross-sectional area has a decreasing tendency toward the downstream side is provided in a flow path from an upstream side edge of the inclined surface to a downstream side edge of the inner peripheral surface, and the inner peripheral surface is a parallel peripheral surface parallel to an outer peripheral surface of the valve core facing the inner peripheral surface, or an inclined peripheral surface in which a radial dimension gradually decreases toward the downstream side.

2. The valve according to claim 1, wherein in the reduction region, a minimum flow path cross-sectional area is constant regardless of a stroke of the valve core.

3. The valve according to claim 1 or 2, wherein a flow path cross-sectional area of the reduction region continuously decreases.

4. The valve according to claim 1 or 2, wherein the inclined surface is formed in a straight line shape.

5. The valve according to claim 1 or 2, wherein the inclined surface constituting the valve seat is formed in a valve seat member separate from the valve housing. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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