valve

Abstract

The present invention provides a valve having high controllability.　A valve V1 is equipped with: a valve housing 10 that has an inflow port 40b and an outflow port 11 formed therein; a valve body 51 that is driven by a drive source 80; a spring 85 that biases the valve body 51 in the opposite direction from the direction of driving by the drive source 80; and a poppet valve 50 that is constituted from the valve body 51 and a valve seat 40a formed on the edge of a through-flow passage 40b. The movement of the valve body 51 is used to control the flow rate. Flow passages C1, C2 on the downstream side of the poppet valve 50 are each provided with an increase region where the flow passage cross-sectional area exhibits a progressive increase toward the downstream side.

Description

[Technical field]

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

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

[0003] When the variable displacement compressor is in continuous operation, the displacement control valve is energized and controlled by the control computer. The electromagnetic force generated by the solenoid moves the valve body in the axial direction, and the valve provided between the discharge port through which the discharge fluid at discharge pressure Pd passes and the control port through which the control fluid at control pressure Pc passes is opened and closed to perform normal control to adjust the control pressure Pc in the control chamber of the variable displacement compressor.

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

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

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

[0007] The displacement control valve of Patent Document 1 uses the pressure difference between the control pressure Pc, which is lower than the discharge pressure Pd, and the suction pressure Ps to control the flow rate of the fluid by opening and closing the poppet valve, so that the flow rate of the fluid passing through the poppet valve can be reduced, but even if a preset current is input to the solenoid, the stroke of the valve body varies due to the influence of the discharge pressure Pd, which is constantly supplied through an orifice to adjust the control pressure Pc, and the opening of the valve may deviate from the target value. From the research of the inventors, it was found that the stroke of the valve body can be influenced by passing a refrigerant with a flow velocity close to the speed of sound through the poppet valve, and by utilizing this, the above-mentioned variation can be suppressed.

[0008] The present invention has been made in consideration of such problems, and has an object to provide a valve with high controllability. [Means for solving the problem]

[0009] In order to solve the above problems, the valve of the present invention comprises: a valve housing having an inlet port and an outlet port formed therein; A valve body driven by a drive source; a spring that biases the valve body in a direction opposite to a drive direction of the drive source; A poppet valve including a valve seat formed on an edge of a through-flow passage and the valve body, the poppet valve controlling a flow rate by movement of the valve body, The flow passage downstream of the poppet valve is provided with an increasing region in which the flow passage cross-sectional area increases toward the downstream side. According to this, when the fluid passing through the poppet valve is a supersonic flow, the flow velocity of the fluid passing through the increasing region in the flow path downstream of the poppet valve increases, and the downstream pressure of the poppet valve decreases. As a result, a force in the valve opening direction acts on the valve body, and the influence of the pressure of the upstream fluid on the force due to the back pressure acting on the valve body can be suppressed, and the variation in the stroke of the valve body relative to the current value input to the solenoid is suppressed. Also, when the fluid passing through the poppet valve is a subsonic flow, the flow velocity of the fluid passing through the increasing region in the flow path downstream of the poppet valve decreases, and the downstream pressure of the poppet valve increases. As a result, a force in the valve closing direction acts on the valve body, the valve closing characteristic is improved, and the poppet valve can be closed with a small current value. As a result, the opening degree of the poppet valve can be accurately adjusted.

[0010] The increasing region may have a flow passage cross-sectional area that increases continuously. This makes it possible to stabilize the flow of fluid passing through the increased area in the flow passage downstream of the poppet valve and eliminate stagnation.

[0011] The poppet valve may be configured by the valve seat having an inclined cross-sectional shape and the valve body having a curved cross-sectional shape. This creates an increased area between the valve seat and the valve body that constitute the poppet valve, making it possible to stabilize the flow of fluid passing through the poppet valve in the tangential direction when the valve body is in the closed or throttling position.

[0012] The inclined shape may be linear. This allows the flow of fluid passing through the poppet valve to be directed tangentially when the valve body is in the closed or throttling position, while being guided along the inclined surface, thereby stabilizing the flow of fluid up to the downstream side of the poppet valve.

[0013] The inclined surface constituting the valve seat may be continuous with an opening of the outflow port. According to this, the flow of fluid passing through the poppet valve is guided along the inclined surface that constitutes the valve seat to the opening of the outlet port, so that the downstream pressure of the poppet valve can be stabilized.

[0014] The valve seat may be formed in a valve seat member separate from the valve housing. This allows the inclined surface that constitutes the valve seat to be extended close to the outflow port. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a cross-sectional view showing a state in which a CS valve is opened in a non-energized state of the capacity control valve according to the first embodiment of the present invention. [Diagram 2] 4 is a cross-sectional view showing a state in which a valve seat member is press-fitted into a valve housing of the displacement control valve of the first embodiment. FIG. [Diagram 3] 4 is an enlarged cross-sectional view showing an increased region in a flow passage downstream of a CS valve in a capacity control valve of the first embodiment in an energized state (during normal control). FIG. [Figure 4] FIG. 1A is a diagram showing a schematic diagram of the valve closing characteristics in a supersonic flow of the capacity control valve of the first embodiment in which the flow path cross-sectional area tends to increase, and FIG. 1B is a diagram showing a schematic diagram of the valve closing characteristics of the comparative example in which the flow path cross-sectional area is constant. [Diagram 5] FIG. 1A is a diagram showing a schematic diagram of the valve closing characteristics in a subsonic flow of the capacity control valve of the first embodiment in which the flow path cross-sectional area tends to increase, and FIG. 1B is a diagram showing a schematic diagram of the valve closing characteristics of a comparative example in which the flow path cross-sectional area is constant. [Figure 6]FIG. 11 is a cross-sectional view showing a state in which a CS valve is opened in a non-energized state of a capacity control valve according to a second embodiment of the present invention. [Figure 7] FIG. 10A is a cross-sectional view showing how a valve seat member is press-fitted into a valve housing of a displacement control valve of a second embodiment, and FIG. 10B is a view showing a Ps port when the XX cross section of (a) is viewed from the outer diameter side of the valve housing. [Figure 8] FIG. 11 is an enlarged cross-sectional view showing an increased region in a flow passage downstream of a CS valve in a capacity control valve according to a second embodiment in an energized state (during normal control). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A valve according to the present invention will be described below based on an embodiment. Note that although the embodiment will be described using a capacity control valve as an example, the present invention can also be applied to other uses. EXAMPLES

[0017] A displacement control valve according to a first embodiment will be described with reference to Fig. 1 to Fig. 3. In the following description, the left and right sides as viewed from the front side of Fig. 1 will be referred to as the left and right sides of the displacement control valve. In particular, the left side of the drawing where the valve housing 10 is arranged will be referred to as the left side of the displacement control valve, and the right side of the drawing where the solenoid 80 is arranged will be referred to as the right side of the displacement control valve.

[0018] The capacity control valve of the present invention is incorporated in a variable capacity compressor (not shown) used in the air conditioning system of an automobile or the like, and controls the discharge volume of the variable capacity compressor by variably controlling the pressure of a working fluid (hereinafter simply referred to as "fluid") which is a refrigerant, thereby adjusting the air conditioning system to achieve a target cooling capacity.

[0019] First, the variable displacement compressor will be described. The variable displacement compressor has a casing that includes a discharge chamber, a suction chamber, a control chamber, and a number of cylinders. The variable displacement compressor is provided with a communication passage that directly connects the discharge chamber and the control chamber. This communication passage is provided with a fixed orifice 9 for balancing the pressures of the discharge chamber and the control chamber (see FIG. 1).

[0020] The variable displacement compressor includes a rotating shaft, a swash plate, and a plurality of pistons. The rotating shaft is driven to rotate by an engine (not shown) installed outside the casing. The swash plate is connected to the rotating shaft in a control chamber so as to be tiltable by a hinge mechanism. The pistons are connected to the swash plate and fitted in their respective cylinders so as to be capable of reciprocating motion. The variable displacement compressor uses a displacement control valve V1, which is driven to open and close by an electromagnetic force, to utilize the suction pressure Ps of the suction chamber that draws in the fluid, the discharge pressure Pd of the discharge chamber that discharges the fluid pressurized by the pistons, and the control pressure Pc of the control chamber that houses the swash plate, and by appropriately controlling the pressure in the control chamber, the inclination angle of the swash plate is continuously changed to change the stroke amount of the pistons, thereby controlling the discharge amount of the fluid.

[0021] 1, the displacement control valve V1 of the first embodiment, which is incorporated in a variable displacement compressor, adjusts the current flowing through a coil 86 constituting a solenoid 80 as a drive source to control the opening and closing of a CS valve 50 as a poppet valve in the displacement control valve V1. This controls the fluid flowing from the control chamber to the suction chamber, thereby variably controlling the control pressure Pc in the control chamber. Note that the discharge fluid at the discharge pressure Pd of the discharge chamber is constantly supplied to the control chamber via a fixed orifice 9, and the control pressure Pc in the control chamber can be increased by closing the CS valve 50 in the displacement control valve V1.

[0022] In the capacity control valve V1 of the first embodiment, the CS valve 50 is composed of a CS valve body 51 as a valve body and a CS valve seat 40a as a valve seat. The CS valve seat 40a is formed in a cylindrical valve seat member 40 that is press-fitted and fixed in a recess 10a of the valve housing 10. The CS valve 50 opens and closes when an abutment portion 51a formed at the axial left end of the CS valve body 51 moves axially toward and away from the CS valve seat 40a.

[0023] Next, the structure of the displacement control valve V1 will be described. As shown in Fig. 1, the displacement control valve V1 is mainly composed of a valve housing 10, a valve seat member 40, a CS valve body 51, and a solenoid 80. The valve housing 10 and the valve seat member 40 are made of a metal material. The CS valve body 51 is arranged in the valve housing 10 so as to be able to reciprocate in the axial direction. The solenoid 80 is connected to the valve housing 10 and applies a driving force to the CS valve body 51.

[0024] As shown in Fig. 1, the CS valve body 51 is composed of a large diameter portion 51b and a small diameter portion 51c. The large diameter portion 51b is made of a metal material or a resin material and is a columnar body with a constant cross section. The small diameter portion 51c extends axially rightward from the inner diameter side of the axial right end of the large diameter portion 51b. The CS valve body 51 also serves as a rod that is disposed to pass through the coil 86 of the solenoid 80.

[0025] An abutment portion 51a having a curved cross-sectional shape that bulges toward the CS valve seat 40a is formed on the left axial end face of the CS valve body 51, i.e., the left axial end face of the large diameter portion 51b. More specifically, the curved shape of the abutment portion 51a is formed by a part of a sphere having a constant radius of curvature. Note that the abutment portion 51a does not have to be formed by a part of a sphere having a constant radius of curvature as long as the curved shape allows the abutment portion 51a to seat on the CS valve seat 40a.

[0026] As shown in FIG. 1, the solenoid 80 is mainly composed of a casing 81, a center post 82, the CS valve body 51, a movable iron core 84, a coil spring 85, and an exciting coil 86. The casing 81 has an opening 81a that opens to the left in the axial direction. The center post 82 is inserted into the opening 81a of the casing 81 from the left in the axial direction and is disposed between the inner diameter side of the casing 81 and the inner diameter side of the valve housing 10, and has a substantially cylindrical shape. The CS valve body 51 is inserted into the center post 82 and is capable of reciprocating in the axial direction, and its left end in the axial direction is disposed in the valve housing 10. The movable iron core 84 is inserted and fixed to the right end in the axial direction of the CS valve body 51. The coil spring 85 is disposed between the center post 82 and the movable iron core 84, and biases the movable iron core 84 to the right in the axial direction, which is the valve opening direction of the CS valve 50. The coil 86 is wound around the outside of the center post 82 via a bobbin.

[0027] The center post 82 includes a cylindrical portion 82b and an annular flange portion 82d. The cylindrical portion 82b is formed from a rigid body that is a magnetic material such as iron or silicon steel, and is formed with an insertion hole 82c that extends in the axial direction and through which the CS valve body 51 is inserted. The flange portion 82d extends radially outward from the outer circumferential surface of the left axial end of the cylindrical portion 82b.

[0028] As shown in Fig. 1, a valve housing 10 is formed with a Ps port 11 as an outflow port. The Ps port 11 penetrates radially and communicates with the suction chamber of the variable displacement compressor. A recess 10a is formed on the axial left side of the valve housing 10, into which a cylindrical valve seat member 40 is press-fitted from the axial left. A Pc port is formed in the valve housing 10 as an inflow port. The valve seat member 40 is press-fitted and fixed in the recess 10a, so that the Pc port communicates with the control chamber of the variable displacement compressor via a through hole 40b that penetrates the valve seat member 40 in the axial direction.

[0029] A valve chamber 20 is formed inside the valve housing 10, and a contact portion 51a of a CS valve element 51 is arranged so as to be able to reciprocate axially inside the valve chamber 20. In addition, the Ps port 11 extends radially inward from the outer circumferential surface of the valve housing 10 and communicates with the valve chamber 20.

[0030] Thus, inside the valve housing 10, the through hole 40b of the valve seat member 40, the valve chamber 20, and the Ps port 11 define a flow passage that communicates between the control chamber and the suction chamber of the variable displacement compressor.

[0031] A guide hole 10c is formed in the inner peripheral surface of the valve housing 10. The guide hole 10 is formed axially to the right of the valve chamber 20 where the solenoid 80 is attached, and the outer peripheral surface 51d (see FIG. 3) of the large diameter portion 51b of the CS valve body 51 is slidable therein. Note that a minute gap is formed between the inner peripheral surface of the guide hole 10c and the outer peripheral surface 51d of the large diameter portion 51b of the CS valve body 51 by being slightly separated in the radial direction, and the CS valve body 51 can move smoothly relative to the valve housing 10 in the axial direction.

[0032] As shown in FIG. 2, the recess 10a of the valve housing 10 is formed so that its inner diameter R1 is larger than the inner diameter R2 of the valve chamber 20 (R1>R2), so that 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 member 40.

[0033] 1, a recess 10d recessed axially leftward is formed on the axial right side of the valve housing 10. A flange portion 82d of a center post 82 is inserted and fixed in place in the recess 10d from the axial right side in a substantially sealed manner, and the casing 81 is further inserted and fixed in place in a substantially sealed manner from the axial right side, thereby being connected together.

[0034] In this manner, when the valve housing 10, center post 82, and casing 81 are connected together, the axially right end face of the valve housing 10 and the axially right side face of the flange portion 82d of the center post 82 abut against the bottom surface of the recess 81b formed on the axially left side of the casing 81, and the bottom surface of the recess 10d of the valve housing 10 and the axially left end face of the center post 82 are separated in the axial direction to form a gap.

[0035] Further, a through hole 21 is formed in the valve housing 10. The through hole 21 is formed to extend in the axial direction between the axial left end face of the valve housing 10 and the bottom of the recess 10d. The through hole 21 is composed of a small diameter hole portion 211 whose axial left end communicates with the control chamber of the variable displacement compressor, and a large diameter hole portion 212 which extends continuously 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 opens into a gap formed between the bottom surface of the recess 10d and the axial left end face of the center post 82. The small diameter hole portion 211 of the through hole 21 and the through hole 40b of the valve seat member 40 are supplied with a control fluid of a control pressure Pc from the control chamber of the variable displacement compressor.

[0036] In the large diameter hole portion 212 of the through hole 21, there are disposed a ball-shaped operating valve element 31 and a return spring 32 whose axial right end is fixed to the axial left end face of the center post 82 and whose axial left end abuts against the operating valve element 31 from the axial right. The operating valve element 31 is biased axially leftward by the return spring 32. The operating valve element 31 and the return spring 32 constitute a pressure operated valve 30 that controls communication between a control chamber of the variable displacement compressor and a space S inside the casing 81 in the through hole 21.

[0037] For convenience of explanation, illustration is omitted, but when the control pressure Pc is high, the operating valve element 31 of the pressure operated valve 30 moves axially rightward against the biasing force of the return spring 32 and the pressure of the fluid in the space S inside the casing 81, and opens by being separated from the valve seat 213 having a cross-sectionally inclined shape formed at the connecting portion between the axial right end of the small diameter hole portion 211 of the through hole 21 and the axial left end of the large diameter hole portion 212. As a result, the control chamber of the variable displacement compressor and the space S inside the casing 81 communicate with each other via the through hole 21, and 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 casing 81 through the through hole 21, and the difference between the pressure of the fluid in the space S inside the casing 81 and the pressure of the control fluid in the through hole 40b of the valve seat member 40 becomes small, so that the CS valve element 51 can be smoothly operated axially leftward, i.e., in the valve closing direction, and the responsiveness of the variable displacement compressor to control at high output can be improved.

[0038] In the valve housing 10, a minute 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 body 51 functions as a throttle. This allows the fluid in the space S inside the casing 81 to slowly escape to the Ps port 11. When not in use for an extended period of time, the pressure difference between the fluid pressure in the valve chamber 20 and the fluid pressure in the space S inside the casing 81 is maintained small.

[0039] Here, the valve seat member 40 will be described. As shown in Fig. 2, the valve seat member 40 is made of a metal material harder than the metal material used for the valve housing 10. Furthermore, the valve seat member 40 is made of a material different from that of the CS valve body 51.

[0040] The valve seat member 40 is cylindrical and has a through hole 40b penetrating in the axial direction. A CS valve seat 40a with a cross-sectionally inclined shape is formed at the right end of the valve seat member 40 in the axial direction. The CS valve seat 40a is formed with an annular flat surface 40c from the outer diameter side to the inner diameter side, and the flat surface 40c is connected to the inner diameter side and gradually reduces in diameter toward the left in the axial direction. That is, the CS valve seat 40a is formed on the edge of the through hole 40b as a through flow passage, and is composed of a tapered surface with a cross-sectionally linear inclined surface extending in the circumferential direction.

[0041] Furthermore, by abutting the flat surface 40c on the axial right side of the valve seat member 40 against the receiving portion 10b formed by the bottom surface of the recess 10a in the axial direction (see FIG. 3), it is possible to regulate the degree of insertion of the valve seat member 40 into the recess 10a and to improve the sealing performance between the valve housing 10 and the valve seat member 40. At this time, the outer diameter end of the tapered surface constituting the CS valve seat 40a is arranged so as to be continuous with the axial left end of the inner circumferential surface 10e of the valve chamber 20 of the valve housing 10.

[0042] As a result, a flow path on the downstream side of the CS valve 50 extending to the opening on the valve chamber 20 side of the Ps port 11 is formed by a flow path C1 formed between the tapered surface constituting the CS valve seat 40a of the valve seat member 40 and the abutting portion 51a of the CS valve body 51, and a flow path C2 formed between the tapered surface constituting the CS valve seat 40a, the outer circumferential surface 51d of the large diameter portion 51b of the CS valve body 51, and between the inner circumferential surface 10e of the valve housing 10 and the outer circumferential surface 51d of the large diameter portion 51b of the CS valve body 51 (see FIG. 3). Note that FIG. 3 shows a state in which the CS valve body 51 has been stroked to a throttling position near the closed position during normal control of the displacement control valve V1.

[0043] In the present Example 1, the flow path C1 forms an increasing region where the flow path cross-sectional area A2 between the tapered surface of the CS valve seat 40a and the outer diameter end of the contact portion 51a of the CS valve body 51 is larger than the flow path cross-sectional area A1 between the inner diameter end of the tapered surface of the CS valve seat 40a and the contact portion 51a of the CS valve body 51 (A1 < A2), and the flow path cross-sectional area has an increasing tendency (dA > 0) as it goes downstream. Further, the flow path C2 forms an increasing region where the flow path cross-sectional area A4 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 body 51 is larger than the flow path cross-sectional area A3 between the tapered surface of the CS valve seat 40a and the outer peripheral surface 51d of the CS valve body 51 (A3 < A4), and the flow path cross-sectional area has an increasing tendency (dA > 0) as it goes downstream. In the state of FIG. 3 where the CS valve body 51 is stroked to the throttle position during normal control of the capacity control valve V1, the upstream flow path cross-sectional area A3 in the flow path C2 is larger than the downstream flow path cross-sectional area A2 in the flow path C1 (A2 < A3).

[0044] Note that the increasing region is formed within the stroke range of the contact portion 51a of the CS valve body 51 in the downstream flow path of the CS valve 50.

[0045] Also, the flow path cross-sectional area of the flow path C1 continuously increases as it goes downstream. On the other hand, since the inner peripheral surface 10e of the valve housing 10 and the outer peripheral surface 51d of the CS valve body 51 are arranged in parallel, the downstream flow path cross-sectional area A4 of the flow path C2 is constant.

[0046] Next, the changes in the flow velocity and pressure of the fluid passing through the downstream flow paths C1 and C2 of the CS valve 50 will be described. Note that the control pressure Pc will be described as being controlled within the range in which the closing of the pressure-actuated valve 30 described above is maintained. The relationship between the cross-sectional area and pressure in an isentropic flow is shown below.

[0047]

Equation

[0048] p: Pressure γ: specific heat ratio M: Mach number A: Area

[0049] Based on this relational expression between the cross-sectional area and the pressure, when the pressure difference between the control pressure Pc in the through hole 40b of the valve seat member 40 and the suction pressure Ps in the Ps port 11, i.e., the Pc-Ps pressure difference, is large and the fluid passing through the CS valve 50 is a supersonic flow (M>1), the fluid passing through the flow path C1, which constitutes an increasing region in which the flow path cross-sectional area tends to increase (dA>0) as it moves downstream in the flow path on the downstream side of the CS valve 50, increases in flow velocity and decreases in pressure. The fluid passing through the flow path C2, which is continuous with the downstream side of the flow path C1 and constitutes an increasing region in which the flow path cross-sectional area tends to increase (dA>0) as it moves downstream, further increases in flow velocity and decreases in pressure, and then passes through the downstream side of the flow path C2, where the flow path cross-sectional area is constant, thereby flowing stably with almost no change in flow velocity and pressure, and flowing into the Ps port 11 (see FIG. 3).

[0050] 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 flow velocity of the fluid passing through flow path C1, which constitutes an increasing region in the flow path downstream of the CS valve 50, decreases and the pressure increases. Also, the fluid passing through flow path C2, which constitutes an increasing region that continues downstream of flow path C1 and whose flow path cross-sectional area tends to increase (dA>0) as it goes downstream, further decreases in flow velocity and increases in pressure, and then flows stably with almost no change in flow velocity and pressure by passing through the downstream side of flow path C2 where the flow path cross-sectional area is constant, and flows into the Ps port 11 (see FIG. 3).

[0051] Furthermore, the downstream pressure of the CS valve 50, i.e., the pressure of the fluid in the valve chamber 20, is easily affected by the discharge pressure Pd that is constantly supplied via a fixed orifice 9 (see Figure 1) to adjust the control pressure Pc in the control chamber of the variable displacement compressor, and therefore the pressure is less likely to drop than in the Ps port 11.

[0052] In the first embodiment, as described above, the downstream pressure of the CS valve 50 can be reduced by passing through the increasing region with the supersonic flow, and therefore the influence of the discharge pressure Pd on the fluid pressure in the space S inside the casing 81 (see FIG. 1 ), which changes based on the pressure difference with the fluid pressure in the valve chamber 20, i.e., the force due to the back pressure acting on the CS valve body 51, can be suppressed. Also, the downstream pressure of the CS valve 50 can be increased in addition to the influence of the discharge pressure Pd by passing through the increasing region with the subsonic flow, and therefore the pressure of the fluid in the space S inside the casing 81, which changes based on the pressure difference with the fluid pressure in the valve chamber 20, i.e., the force due to the back pressure acting on the CS valve body 51, can be further increased.

[0053] As described above, in the capacity control valve V1 of the first embodiment, the flow path downstream of the CS valve 50 is provided with the flow paths C1 and C2 as an increasing region in which the flow path cross-sectional area tends to increase (dA>0) toward the downstream side. When the fluid passing through the CS valve 50 is a supersonic flow (M>1), the flow velocity of the fluid passing through the flow paths C1 and C2 increases, the pressure decreases, and a force in the valve opening direction acts on the CS valve body 51. As a result, as shown in FIG. 4(a), the influence of the pressure of the fluid upstream of the CS valve 50 on the downstream pressure of the CS valve 50, which is the discharge pressure Pd in ​​this embodiment, can be suppressed. Note that in the reference diagram of FIG. 4(b) showing the characteristics of a flow path with a constant flow path cross-sectional area (dA=constant), the variation in the drive current is large. In this way, the effect of the discharge pressure Pd on the force due to the back pressure acting on the CS valve body 51 can be suppressed, the variation in the stroke of the CS valve body 51 in response to the current value input to the solenoid 80 is suppressed, and the opening degree of the CS valve 50 can be precisely adjusted.

[0054] Furthermore, when the fluid passing through the CS valve 50 is a subsonic flow (M<1), the flow velocity of the fluid passing through the flow paths C1 and C2 decreases and the pressure increases, and a force in the valve closing direction acts on the CS valve element 51. Also, the force of the back pressure acting on the CS valve element 51, which is affected by the discharge pressure Pd, can be further increased. As a result, as shown in FIG. 5(a), the valve closing characteristics of the CS valve 50 are improved, and the CS valve 50 can be closed with a small current value. Note that in FIG. 5(b), which is a reference diagram showing the characteristics of a flow path with a constant flow path cross-sectional area (dA=constant), the valve cannot be closed when the discharge pressure Pd is high, in other words, a large current is required to close the valve.

[0055] In this way, flow paths C1 and C2, which are increasing regions in which the flow path cross-sectional area tends to increase (dA>0) downstream, are provided in the flow path downstream of the CS valve 50, and the controllability of the CS valve 50 can be improved 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.

[0056] In addition, the cross-sectional area of ​​the flow path C1 as the increasing region increases continuously toward the downstream side, thereby stabilizing the flow of the fluid and eliminating stagnation. Also, the flow velocity and pressure of the fluid passing through the flow path C1 can be changed at an accelerated rate.

[0057] In addition, the CS valve 50 is composed of a CS valve seat 40a having an inclined cross-sectional shape and a contact portion 51a of the CS valve body 51 having a curved cross-sectional shape, and a flow path C1 is formed as an increased region between the tapered surface constituting the CS valve seat 40a and the abutment portion 51a of the CS valve body 51, so that when the CS valve body 51 is in the closed position or throttling position, the flow of fluid passing through the CS valve 50 can be stabilized in the tangential direction (see solid arrow in Figure 3).

[0058] In addition, the CS valve seat 40a is composed of a tapered surface with a linear cross-sectional inclined surface extending circumferentially, and stabilizes the flow of fluid passing through the CS valve 50, more specifically the flow of fluid upstream of flow paths C1 and C2, in the tangential direction when the CS valve body 51 is in the closed position or throttling position, and can guide the flow of fluid along the inclined surface, thereby stabilizing the flow of fluid up to the downstream side of the CS valve 50.

[0059] In addition, it is preferable that the tapered surface constituting the CS valve seat 40a is located downstream along the normal to the abutment portion 51a of the CS valve body 51. This causes the fluid that has passed through the increased region to proceed in a straight line, making it difficult to impede the flow velocity of the fluid, which is close to the speed of sound.

[0060] Furthermore, on the downstream side of the flow path C2, the cross-sectional area of ​​the flow path is constant up to the opening of the Ps port 11 on the valve chamber 20 side, and the flow of the fluid can be stabilized with almost no change in the flow velocity and pressure of the passing fluid, so that the pressure of the fluid in the valve chamber 20 is easily stabilized.

[0061] In addition, the flow path C1 can form an increased area by utilizing the tapered surface constituting the CS valve seat 40a in the CS valve 50 serving as a poppet valve and the abutment portion 51a of the CS valve body 51, thereby simplifying the structure of the displacement control valve V1.

[0062] Furthermore, since the CS valve seat 40a is formed on the valve seat member 40 which is separate from the valve housing 10, the machining precision of the tapered surface for forming the increased area can be improved.

[0063] In the first embodiment, the flow path C2 continuing downstream from the flow path C1 has been described as having a constant flow path cross-sectional area on the downstream side due to the inner circumferential surface 10e of the valve housing 10 and the outer circumferential surface 51d of the CS valve body 51 being arranged in parallel. However, the present invention is not limited to this. The shapes of the inner circumferential surface 10e of the valve housing 10 and the outer circumferential surface 51d of the CS valve body 51 may be changed so as to continuously form an increasing region in which the flow path cross-sectional area tends to increase (dA>0) downstream as well. EXAMPLES

[0064] A displacement control valve according to a second embodiment will be described with reference to Fig. 6 to Fig. 8. Note that a description of the same configuration as in the first embodiment will be omitted.

[0065] As shown in FIG. 6, in the displacement control valve V2 of the second embodiment, a valve housing 110 is formed with a Ps port 111 as an outflow port that penetrates radially and communicates with the suction chamber of the variable displacement compressor.

[0066] A first recess 110a is formed on the axial left side of the valve housing 110. A flanged cylindrical valve seat member 140 is press-fitted into the first recess 110a from the axial left. By press-fitting and fixing the valve seat member 140 into the first recess 110a, a Pc port is formed in the valve housing 110 as an inlet port communicating with a control chamber of the variable displacement compressor via a through-hole 140b that passes through the valve seat member 140 in the axial direction.

[0067] A valve chamber 120 is formed inside the valve housing 110 by a first recess 110a and a small-diameter second recess 110b formed continuously to the axial right of the first recess 110a. The contact portion 51a of the CS valve body 51 is arranged in the valve chamber 120 so as to be able to reciprocate axially. The Ps port 111 extends radially inward from the outer circumferential surface of the valve housing 110 and communicates with the valve chamber 120.

[0068] 7(a), the first recess 110a of the valve housing 110 is formed so that its inner diameter R11 is larger than the inner diameter R12 of the second recess 110b (R11>R12), so that an annular step 114 is formed in the valve chamber 120 by an inner peripheral surface 110d of the first recess 110a, a bottom surface 110e extending in the inner radial direction from the axial right end of the inner peripheral surface 110d of the first recess 110a, and an inner peripheral surface 110f of the second recess 110b extending in the axial right direction from the inner radial end of the bottom surface 110e of the first recess 110a. The annular step 114 is interrupted in the circumferential direction at the position of the Ps port 111.

[0069] The opening of the Ps port 111 on the valve chamber 120 side is arranged across the inner circumferential surface 110d of the first recess 110a and the inner circumferential surface 110f of the second recess 110b in the axial direction, forming a step shape. The opening on the valve chamber 120 side communicates with the first recess 110a and the second recess 110b, and is also open to the axial left at the bottom surface 110e of the first recess 110a and communicates with the first recess 110a (see FIG. 7(b)).

[0070] As shown in Fig. 7(a), the valve seat member 140 is cylindrical with a through hole 140b penetrating in the axial direction. A CS valve seat 140a is formed as a valve seat at the right end in the axial direction of the valve seat member 140. The CS valve seat 140a is formed with an annular flat surface 140c from the outer diameter side to the inner diameter side, and a cross-sectional inclined shape that is connected to the flat surface 140c from the inner diameter side and gradually reduces in diameter toward the left in the axial direction. That is, the CS valve seat 140a is formed on the edge of the through hole 140b as a through flow passage, and is composed of a tapered surface in which a cross-sectional linear inclined surface extends in the circumferential direction.

[0071] In addition, a flange portion 140d is formed at the axial left end of the valve seat member 140, protruding from the outer peripheral surface in the outer diameter direction, and the axial right side surface of the flange portion 140d is brought into axial contact with the axial left end surface of the valve housing 110 (see FIG. 8), thereby regulating the insertion progress of the valve seat member 140 into the first recess 110a. At this time, the outer diameter end of the flat surface 140c is disposed radially continuous with the inner peripheral surface of the Ps port 111 that opens into the inner peripheral surface 110d of the first recess 110a of the valve housing 110. In addition, the outer diameter end of the tapered 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 tapered surface constituting the CS valve seat 140a extends to a position where it axially overlaps with the opening of the Ps port 111 on the valve chamber 120 side.

[0072] As a result, a downstream flow path of the CS valve 50 that extends to the stepped opening on the valve chamber 120 side of the Ps port 111 is formed by a flow path C101 formed between the tapered surface constituting the CS valve seat 140a of the valve seat member 140 and the contact portion 51a of the CS valve body 51, a flow path C102 formed between the tapered surface constituting the CS valve seat 140a of the valve seat member 140 and the outer peripheral surface 51d of the large-diameter portion 51b of the CS valve body 51, and a flow path 103 formed between the flat surface 140c of the valve seat member 140 and the bottom surface 110e of the first recess 110a constituting the stepped portion 114 (see FIG. 8). Note that FIG. 8 shows a state in which the CS valve body 51 is stroked to a throttle position near the closed position during normal control of the capacity control valve V2.

[0073] In the second embodiment, the flow path C101 has a flow path cross-sectional area A102 between the outer diameter end of the tapered surface constituting the CS valve seat 140a and the contact portion 51a of the CS valve body 51 that is larger than the flow path cross-sectional area A101 between the inner diameter end of the tapered surface constituting the CS valve seat 140a and the contact portion 51a of the CS valve body 51 (A101 < A102), and constitutes an increasing region in which the flow path cross-sectional area has an increasing tendency (dA > 0) as it goes downstream. Further, the flow path C102 is linearly extended such that the outer diameter portion of the tapered surface constituting the CS valve seat 140a overlaps with the opening on the valve chamber 120 side of the Ps port 111 in the axial direction, so that the upstream flow path cross-sectional area A103 in the flow path C102 is larger than the downstream flow path cross-sectional area A2 in the flow path C101 (A102 < A103), and constitutes an increasing region in which the flow path cross-sectional area has an increasing tendency (dA > 0) as it goes downstream.

[0074] Further, the flow path cross-sectional area of the flow path C101 continuously increases as it goes downstream. Also, the flow path cross-sectional area of the flow path C102 continuously increases as it goes downstream, but since the outer peripheral surface 51d of the CS valve body 51 extends linearly in the axial direction with respect to the tapered surface constituting the CS valve seat 140a, the amount of increase in the flow path cross-sectional area is larger than that of the flow path C101.

[0075] The flow passage C103 corresponds to a space on the outer diameter part of the first recess 110a, and communicates with a stepped opening on the valve chamber 120 side of the Ps port 111 at the inner circumferential surface 110d and the bottom surface 110e of the first recess 110a.

[0076] As shown in FIG. 6, the tapered surface constituting the CS valve seat 140a extends over the entire stroke range of the contact portion 51a of the CS valve body 51.

[0077] According to this, in the capacity control valve V2 of the second embodiment, the flow path downstream of the CS valve 50 is provided with flow paths C101 and C102 as an increasing region in which the flow path cross-sectional area tends to increase (dA>0) toward the downstream side. When the fluid passing through the CS valve 50 is a supersonic flow (M>1), the flow velocity of the fluid passing through the flow paths C101 and C102 increases, the pressure decreases, and a force in the valve opening direction acts on the CS valve body 51. This makes it possible to suppress the influence of the pressure of the fluid upstream of the CS valve 50 on the downstream pressure of the CS valve 50, which is the discharge pressure Pd in ​​this embodiment. In this way, the influence of the discharge pressure Pd on the force due to the back pressure acting on the CS valve body 51 can be suppressed, and the variation in the stroke of the CS valve body 51 relative to the current value input to the solenoid 80 is suppressed, and the opening degree of the CS valve 50 can be accurately adjusted.

[0078] Furthermore, when the fluid passing through the CS valve 50 is a subsonic flow (M<1), the flow velocity of the fluid passing through the flow paths C101, C102 decreases and the pressure increases, and a force in the valve closing direction acts on the CS valve element 51. Also, the force due to the back pressure acting on the CS valve element 51, which is affected by the discharge pressure Pd, can be further increased. As a result, the valve closing characteristics of the CS valve 50 are improved, and the CS valve 50 can be closed with a small current value.

[0079] In this way, flow paths C101, C102, which are increasing regions in which the flow path cross-sectional area tends to increase (dA>0) downstream, are provided in the flow path downstream of the CS valve 50, and the controllability of the CS valve 50 can be improved 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.

[0080] In addition, the CS valve seat 140a constituting the flow paths C101, C102 as the increased region is configured with a tapered surface whose outer diameter portion extends linearly to a position where it axially overlaps with the opening of the Ps port 111 on the valve chamber 120 side, making it easier to guide the fluid while acceleratingly changing its flow rate and pressure into the Ps port 111. This makes it possible to stabilize the flow of fluid in the flow path downstream of the CS valve 50 and eliminate stagnation, thereby making it possible to further stabilize the downstream pressure of the CS valve 50, i.e., the pressure of the fluid in the valve chamber 120.

[0081] In addition, since the CS valve seat 140a is formed on the valve seat member 40 which is separate from the valve housing 10, it is possible to improve the machining accuracy of the tapered surface for forming the increased area. Furthermore, the tapered surface constituting the CS valve seat 140a can be extended close to the Ps port 111.

[0082] In this second embodiment, the valve seat member 140 does not need to have the flat surface 140c, and the tapered surface constituting the CS valve seat 140a may be continuous with the outer circumferential surface of the valve seat member 140. In this case, since the outer diameter end of the tapered surface constituting the CS valve seat 140a is continuous with the opening of the Ps port 111 on the valve chamber 120 side, the annular step 114 does not need to be formed on the inner circumferential surface of the valve housing 110.

[0083] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

[0084] For example, in the above embodiment, the valve housing and the valve seat member are described as being made of a metal material, but this is not limiting, and the valve seat member may be made of a resin material or the like as long as it is harder than the hardness of the inside of the flow passage of the valve housing. Also, in this case, it is preferable that the valve seat member is made of a material different from that of the valve body.

[0085] Furthermore, the CS valve body does not need to have a cross-sectional curved shape at the contact portion with the CS valve seat.

[0086] Furthermore, the tapered surface that constitutes the CS valve seat is not limited to being linear, but may be arcuate.

[0087] Furthermore, the increasing region is not limited to a region in which the flow passage cross-sectional area increases continuously due to a tapered surface, but may be a region in which the flow passage cross-sectional area increases stepwise due to a stepped surface.

[0088] In addition, in the above-mentioned first and second embodiments, it has been described that the continuous flow paths C1, C2 or the flow paths C101, C102 downstream of the CS valve 50 all constitute the increasing region, but this is not limited thereto, and it is sufficient that, for example, either the upstream flow paths C1, C101 or the downstream flow paths C2, C102 constitute the increasing region.

[0089] Further, the displacement control valve in the above embodiment has been described using a CS valve as a poppet valve as an example, but the poppet valve may be a DC valve that opens and closes the flow path between the Pd port as the inlet port and the Pc port as the outlet port. [Explanation of symbols]

[0090] 9 Fixed Orifice 10 Valve housing 10a Recess 10b Receiving part 10c Guide hole 10d Recess 10e Inner surface 11 Ps port (outlet 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 passage, inlet port) 40c flat surface 50 CS valve (poppet valve) 51 CS valve body (valve body) 51a Contact part 51d Outer surface 80 Solenoid (drive source) 110 Valve housing 110a First recess 110b Second recess 110d Inner surface 110e bottom 110f Inner surface 111 Ps port (outlet port) 114 Step part 120 Valve chamber 140 Valve seat material 140a CS valve seat (valve seat) 140b through hole (through flow passage, inlet port) 140c flat surface 140d flange C1, C2 flow paths (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 housing having an inlet port and an outlet port formed therein; A valve body driven by a drive source; a spring that biases the valve body in a direction opposite to a drive direction of the drive source; A poppet valve including a valve seat formed on an edge of a through-flow passage and the valve body, the poppet valve controlling a flow rate by movement of the valve body, The flow passage on the downstream side of the poppet valve is provided with an increasing region in which the flow passage cross-sectional area tends to increase toward the downstream side, The poppet valve is configured with the valve seat having a cross-sectional inclined shape and the valve body having a contact portion having a cross-sectional curved shape that contacts the valve seat, The valve seat is formed in a valve seat member separate from the valve housing, The valve housing is formed with a recess into which the valve seat member can be inserted, a flat surface that abuts on a receiving portion formed in the recess is formed at an end portion of the valve seat member in a direction in which the valve seat member is inserted into the recess, and an inclined surface that inclines from the flat surface toward an inner diameter direction of the valve seat member is formed, The inclined surface constitutes the valve seat, a valve in which the inclined surface is continuous with the inner circumferential surface of the valve housing when the receiving portion, in which the valve seat member is inserted into the recess, abuts against the flat surface.

2. 2. The valve of claim 1, wherein the increasing region has a continuously increasing flow passage cross-sectional area.

3. The valve of claim 1 , wherein the cross-sectional tapered shape is linear.

4. 4. The valve according to claim 1, wherein the inclined surface constituting the valve seat is continuous with an opening of the outlet port.

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