Pressure Regulating Valve

Abstract

A pressure regulating valve (11) comprising: a valve main body (12) having a valve chamber (13) that communicates with a refrigerant inflow passage (14) and a refrigerant outflow passage (15); a valve body (17) that changes the flow rate of a refrigerant by advancing to and retreating from a valve seat (16) formed in the valve chamber (13) between a closed state of being seated on the valve seat (16) and an open state of being spaced apart from the valve seat (16); a pressure-sensitive member (21) which biases the valve body (17) toward the valve seat (16) and which expands and contracts according to a pressure received by the valve body (17) from the refrigerant flowing in from the inflow passage (14) to thereby allow the advancement and retreat of the valve body (17); an adjustment means (24) for adjusting a biasing force applied by the pressure-sensitive member (21) to the valve body (17); and an actuator (such as stepper motor) (40) that drives the adjustment means (24). It is preferred for the adjustment means (24) to comprise a stopper member (29) that can stop the movement of an adjustment member caused by the actuator (40) and can serve as a start point for setting the biasing force.

Description

[Technical field]

[0001] The present invention relates to a pressure regulating valve used in a refrigeration cycle system, and more particularly to an evaporating pressure regulating valve equipped with a pressure-sensitive bellows. [Background technology]

[0002] In a refrigeration cycle system, the refrigerant is vaporized in the evaporator and heat is exchanged with the surrounding atmosphere, but when the load is small, the evaporator may become overcooled and frost may form. Once frost forms, the layer of ice blocks ventilation and the cooling efficiency drops sharply, so to prevent this, an evaporation pressure control valve is installed on the outlet piping of the evaporator.

[0003] This evaporator pressure regulating valve prevents frosting on the evaporator by throttling the outlet side flow path of the evaporator and maintaining the pressure inside the evaporator at or above a certain level, and comprises a valve body having a valve chamber communicating with the refrigerant inlet and outlet paths, a valve body that changes the flow rate of refrigerant by moving toward and away from the valve seat between a closed state in which it sits on a valve seat formed in the valve chamber and an open state in which it is spaced from the valve seat, and a pressure-sensitive member that urges the valve body toward the valve seat and expands and contracts in accordance with the pressure that the valve body receives from the refrigerant flowing in from the inlet path, thereby allowing the valve body to move forward and backward, and the outlet side piping of the evaporator is connected to the inlet path.

[0004] The pressure-sensing member consists of a bellows and a compression coil spring installed within the bellows, and the opening degree of the valve is determined by the balance between the force with which the pressure-sensing member presses against the valve body (load in the valve closing direction) and the refrigerant pressure in the inlet passage (evaporation pressure in the evaporator).

[0005] Moreover, the following Patent Document 1 discloses such a pressure regulating valve. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2015-004395 A Summary of the Invention

[0007] Meanwhile, such pressure regulating valves have the advantage of a simple control structure in which the valve opening is determined automatically (mechanically) and does not require a complex control mechanism, but they are prone to variations in valve opening characteristics because the bellows and coil springs that constitute the pressure-sensing member and determine the valve opening characteristics inevitably have a certain degree of variation in their characteristics (expansion and contraction characteristics and spring characteristics) during manufacturing.

[0008] In recent years, there has been a demand for more optimal temperature control by arbitrarily adjusting the evaporator temperature (opening characteristic of the pressure regulating valve) to the high or low temperature side. For example, in an air conditioning system equipped with multiple evaporators, the load between the evaporators may fluctuate due to changes in the operating mode (cooling, heating, dehumidification, etc.) or changes in the indoor conditions.

[0009] However, it is difficult to meet such demands with conventional pressure regulating valves. The pressure-sensing member may be equipped with an adjustment screw for adjusting the biasing force, and it is not impossible to change the valve opening characteristics by manipulating this adjustment screw, but the screw is generally located inside the valve (in the refrigerant flow path), including in the invention described in Patent Document 1, and although it may be manipulated during manufacturing and shipping, it cannot be manipulated after the valve is installed in the system unless the piping is removed.

[0010] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to realize more flexible and optimal control by making it possible to change the valve opening characteristics of a pressure regulating valve as needed.

[0011] In order to solve the above problems and achieve the object, the pressure regulating valve of the present invention is a pressure regulating valve comprising: a valve body having a valve chamber communicating with an inlet passage for introducing a refrigerant and an outlet passage for discharging the refrigerant; a valve body that changes the flow rate of refrigerant by moving back and forth relative to a valve seat formed in the valve chamber between a closed valve state in which it sits on the valve seat and an open valve state in which it is spaced from the valve seat; a pressure-sensitive member that urges the valve body toward the valve seat and allows the valve body to move back and forth by expanding and contracting in accordance with the pressure that the valve body receives from refrigerant flowing in from the inlet passage; and an adjustment means for adjusting the urging force of the pressure-sensitive member against the valve body, and an actuator for driving the adjustment means.

[0012] The pressure regulating valve of the present invention is provided with an adjustment means for adjusting the biasing force of the pressure-sensitive member, and this adjustment means is driven by an actuator. By driving the adjustment means with an actuator and making it possible to change the biasing force (valve opening characteristic) of the pressure-sensitive member at any time, optimal control of the evaporator is possible. The actuator is, for example, an electric motor, and is preferably configured with a stepping motor. It is also possible to use, for example, a servo motor as the actuator, and to drive the adjustment means by feedback control equipped with an encoder, and the present invention also includes such a configuration, but the stepping motor enables low-cost and highly accurate control (load adjustment of the pressure-sensitive member) by open-loop control without a complex control mechanism.

[0013] In addition, as a typical configuration of the adjustment means, when the end of the pressure-sensitive member farthest from the valve body is referred to as the "base end," the adjustment means includes an adjustment member provided at the base end of the pressure-sensitive member, and the actuator may change the biasing force by moving the adjustment member in the expansion / contraction direction of the pressure-sensitive member (the direction of extending or contracting).

[0014] Furthermore, it is preferable that the adjustment means has a stopper member that can be used as a starting point when stopping the movement of the adjustment member by the actuator to set the biasing force of the pressure-sensitive member. This is to enable more accurate setting and changing of the valve opening characteristic (biasing force of the pressure-sensitive member), i.e., the evaporation pressure (temperature) of the evaporator. Taking the example of a case where a stepping motor is used as the actuator, the specific description is as follows.

[0015] (1) First, the actuator (stepping motor) is driven to move the adjustment member until it is stopped by the stopper member. Hereinafter, this movement operation of the adjustment member is referred to as "initialization," the initialized state as the "initial state," and the position of the adjustment member in the initial state as the "initial position."

[0016] (2) Next, the stepping motor is driven to move the adjustment member from the initial position to a position where the desired biasing force (evaporation pressure / this evaporation pressure is referred to as the "first evaporation pressure") is achieved. During this time, the distance from the initial position to the position where the desired biasing force (first evaporation pressure) is achieved is measured as the number of drive pulses of the stepping motor, and the measured value (number of pulses) is stored as a set value (this set value is referred to as the "first set value").

[0017] (3) In the same manner, a set value (this set value is referred to as the "second set value") that is a desired biasing force (evaporation pressure / this evaporation pressure is referred to as the "second evaporation pressure") different from the first evaporation pressure is measured. That is, after performing the initialization operation again, the adjustment member is moved from the initial position as a starting point until the second evaporation pressure is reached, the distance during this movement is measured as the number of drive pulses, and the measured value is saved as the second set value.

[0018] Then, by storing the above-mentioned first and second set values ​​in a memory device provided in a control unit that controls a system that uses the pressure regulating valve of the present invention (for example, an air conditioning system such as a car air conditioner or a room air conditioner, or a refrigeration system such as a freezer-refrigerator), and making it possible for the actuator to be driven by the control unit, it becomes possible to set the pressure in the evaporator to the first evaporation pressure and the second evaporation pressure depending on the operating conditions of the system, etc.

[0019] Furthermore, by measuring and storing three or more set values ​​(evaporation pressures) in the same manner, i.e., the third set value (third evaporation pressure), the fourth set value (fourth evaporation pressure), the fifth set value (fifth evaporation pressure), etc., it becomes possible to switch the setting of the evaporator (pressure regulating valve) to three or more evaporation pressures based on the three or more set values.

[0020] To further explain the present invention, in a mechanical (internal control) regulating valve, the control pressure P (flow-pressure characteristic) relative to the refrigerant flow rate Q is a straight line with a certain gradient as shown by the solid line in Figure 9. Also, in an air conditioning system, an optimal control pressure is required for each operating mode (cooling / heating / dehumidification) and indoor conditions to provide comfortable air conditioning control. For this reason, the regulating valve is designed to have a flow-pressure characteristic with an ideal gradient (called the "ideal characteristic") as shown by the dashed line in Figure 9 that satisfies such requirements.

[0021] On the other hand, in an actual product, ideal characteristics are not always realized due to variations in the dimensions and assembly accuracy of each component during assembly and manufacturing, constraints from the manufacturing cost side, or deterioration of each component due to aging (reduced durability), etc. Even if the biasing force of the pressure-sensing member is adjusted at the time of product shipment so that the ideal control pressure P1 is obtained at the reference refrigerant flow rate Q1 as shown in Fig. 10, not all regulating valves have ideal characteristics, so when incorporated into an air conditioning system, depending on the operating mode and indoor conditions, the control pressure Px at the refrigerant flow rate Qx may deviate from the ideal value (ideal characteristics shown by the dashed line), and optimal air conditioning control may not be realized.

[0022] Therefore, in the present invention, by changing the biasing force using an actuator, the flow rate-pressure characteristic (solid line) of the regulating valve is slid (see symbol S1) so as to match (or approach) the control pressure P2 on the ideal characteristic (dashed line) at the refrigerant flow rate Q2 as shown in Figure 11, thereby achieving more ideal air conditioning control for each operating mode and indoor conditions.

[0023] In the present invention, an electromagnetic actuator (solenoid) can also be used as the actuator. Specifically, in the pressure regulating valve according to this embodiment, the adjustment means includes an adjustment member provided at the base end (the end farther from the valve body) of the pressure-sensitive member, and the actuator is an electromagnetic actuator (solenoid) capable of generating a suction force that attracts the adjustment member in a direction toward the valve body, and the urging force of the pressure-sensitive member against the valve body can be changed by changing the suction force.

[0024] The attractive force (magnetic force) of the solenoid can be changed, for example, by the magnitude of the current (drive current) supplied to the solenoid. Furthermore, when the attractive force draws the adjustment member closer to the valve body (contracts the pressure-sensitive member), the position of the adjustment member is determined by the balance between the elastic force of the pressure-sensitive member (the reaction force of the biasing force on the valve body) and the attractive force of the solenoid, and the biasing force of the pressure-sensitive member on the valve body can be changed by changing the magnitude of the attractive force of the solenoid (the magnitude of the drive current to the solenoid).

[0025] Therefore, if the drive current at which the pressure in the inflow passage becomes a first pressure value (first evaporation pressure) is measured and set as the first set value, and the drive current at which the pressure in the inflow passage becomes a second pressure value (second evaporation pressure) is measured and saved as the second set value, it becomes possible to change the setting of the pressure regulating valve using these first and second set values, just as in the case of using the electric actuator. Note that the set values ​​are not limited to two, and it is possible to change the setting based on three or more set values ​​(third set value, fourth set value, ...), just like in the case of using the electric actuator.

[0026] The pressure regulating valve according to the present invention may also be configured to include a control device that changes the biasing force of the pressure-sensing member as described above.

[0027] Specifically, the pressure regulating valve further includes a control device that controls the actuator, the control device including a memory unit that stores two or more set values ​​related to the biasing force, and a control unit that drives the adjustment means via the actuator, and the control unit drives the adjustment means via the actuator based on the set values ​​pre-stored in the memory unit to change the biasing force of the pressure-sensing member.

[0028] In addition, in this pressure regulating valve, when the end of the pressure-sensitive member farthest from the valve body is referred to as the base end, the adjustment means includes an adjustment member provided at the base end of the pressure-sensitive member, and the two or more setting values ​​are different from each other and are information relating to the position of the adjustment member in the extension / contraction direction of the pressure-sensitive member, and the control unit may change the biasing force of the pressure-sensitive member by moving the adjustment member in the extension / contraction direction of the pressure-sensitive member via an actuator.

[0029] According to the present invention, by making it possible to change the valve opening characteristics of the pressure regulating valve as required, more flexible and optimal temperature control can be realized.

[0030] Other objects, features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a vertical cross-sectional view showing an evaporation pressure regulating valve (in a valve closed state) according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a vertical cross-sectional view showing the evaporation pressure regulating valve (open state) according to the first embodiment. [Diagram 3] FIG. 3 is a vertical cross-sectional view showing the evaporation pressure regulating valve according to the first embodiment (in an initial state in which the regulating member is lowered until stopped by the stopper member). [Figure 4] FIG. 4 is a Mollier diagram showing an air conditioning system (as an example, a building air conditioning system in cooling operation) equipped with the evaporative pressure regulating valve according to the first embodiment. [Diagram 5] FIG. 5 is a Mollier diagram showing an air conditioning system (as another example, a car air conditioner operating in heating and dehumidifying mode) equipped with the evaporative pressure regulating valve according to the first embodiment. [Figure 6] FIG. 6 is a vertical cross-sectional view showing an evaporation pressure regulating valve according to a second embodiment of the present invention (valve closed state / excitation coil not energized state / plunger displaced to the upper limit position). [Figure 7] FIG. 7 is a vertical sectional view showing the evaporation pressure regulating valve according to the second embodiment (in a closed state where the plunger has been displaced to the lower limit position where it collides with the suction element). [Figure 8] FIG. 8 is a vertical cross-sectional view showing the evaporation pressure regulating valve according to the second embodiment (in a closed state / a state in which the plunger is displaced to an intermediate position between the upper limit position and the lower limit position by adjusting the current supplied to the excitation coil). [Figure 9] FIG. 9 is a diagram showing the relationship between the refrigerant flow rate and the control pressure in a mechanical pressure regulating valve. [Figure 10] FIG. 9 is a diagram showing the relationship between the refrigerant flow rate and the control pressure in a mechanical pressure regulating valve, and explains the adjustment operation of the biasing force of the pressure-sensing member at the time of shipping the regulating valve. [Figure 11] FIG. 11 is a diagram showing the relationship between the refrigerant flow rate and the control pressure in a mechanical pressure regulating valve, illustrating a state in which the biasing force of the pressure-sensitive member is changed based on the present invention. [Figure 12] FIG. 12 is a flowchart showing an example of processing executed by the control unit to optimally control air conditioning in each room in the air conditioning system including the regulating valve of the first embodiment. BEST MODE FOR CARRYING OUT THEINVENTION

[0032] [First embodiment] A pressure regulating valve according to a first embodiment of the present invention will be described with reference to Fig. 1 to Fig. 5. The pressure regulating valve 11 according to this embodiment (the same applies to the second embodiment described later) is an evaporation pressure regulating valve (hereinafter sometimes simply referred to as a "pressure regulating valve" or "regulating valve") that is provided in the outlet piping of an evaporator of an air conditioning system and maintains the pressure inside the evaporator at a certain level or higher. In addition, two-dimensional orthogonal coordinates representing the up, down, left, and right directions are appropriately displayed in each figure, and the following description will be based on these directions.

[0033] As shown in FIGS. 1 and 2, an evaporation pressure regulating valve 11 according to a first embodiment of the present invention comprises a valve body 12 having a valve chamber 13 communicating with an inflow passage 14 for introducing a refrigerant and an outflow passage 15 for discharging the refrigerant, a valve element 17 that changes the flow rate of the refrigerant by moving toward and away from the valve seat 16 (moving up and down) between a closed state (see FIG. 1) in which the valve element 17 abuts against a valve seat 16 formed in the valve chamber 13 and an open state (see FIG. 2) in which the valve element 17 is spaced from the valve seat 16, and a valve element 17 that biases the valve element 17 toward the valve seat 16 and expands and contracts in response to the pressure that the valve element 17 receives from the refrigerant flowing in from the inflow passage 14. the valve chamber 13, and a stopper member 29 that restricts (physically or mechanically stops) the downward movement of the adjustment member 24.

[0034] The valve chamber 13 is disposed in the vertical middle of the valve body 12, and the inflow passage 14 communicating with the valve chamber 13 extends vertically upward from the underside of the valve body 12 and opens into the bottom surface of the valve chamber 13. A valve seat 16 is formed at the upper edge of the inflow passage 14 where it opens into the valve chamber 13. On the other hand, the outflow passage 15 extends horizontally (to the right in Figs. 1 and 2) from the side surface of the valve chamber 13 and opens into the peripheral surface of the valve body 12.

[0035] The pressure-sensitive bellows 21 comprises a bellows body 22 having a bottomed, open-ended cylindrical shape with a bellows-like peripheral wall, a compression coil spring 23 accommodated in a compressed state inside the bellows body 22, and a valve element 17 connected to the lower end thereof via a connecting plate 18. The upper surface of the bellows body 22 is closed by joining an adjustment member 24. That is, the adjustment member 24 has a disk-shaped flange portion 25 and a guide shaft portion 26 standing vertically upward from the center of the flange portion 25, and the upper surface of the bellows body 22 is closed by welding the flange portion 25 to the upper surface of the bellows body 22.

[0036] The top lid 27, which closes the upper part of the valve chamber 13, comprises a top lid main body 27a which is fixed by screwing it into the top opening 12a of the valve body 12, and a flange portion 27b which extends horizontally outward from the upper surface of the top lid main body 27a and abuts the upper surface of the valve body 12. It is a cup-shaped member with a bottom and no lid, and has a connecting member accommodating hole 27c on the upper surface side of the top lid main body 27a for receiving the connecting member 28. The center of the connecting member accommodating hole 27c has a bottom hole 27e which penetrates the bottom plate portion (also referred to as the "top lid bottom plate portion") 27d of the top lid main body 27a and allows the guide shaft portion 26 of the adjustment member 28 to be inserted therethrough so that it can slide in the vertical direction. In addition, a space S (called the "stopper arrangement space") is formed between the bottom surface of the connecting member accommodating hole 27c (the upper surface of the upper lid bottom plate portion 27d) and the lower surface of the connecting member 28 in which the stopper member 29 can be arranged and which allows the stopper member 29 to move up and down.

[0037] On the other hand, the connecting member 28 is a cylindrical member having a large diameter hole 28a and a small diameter hole 28b which are through holes communicating with each other. The large diameter hole 28a penetrates the upper part of the connecting member 28 and has a large diameter so that a bearing member 34 described later can be inserted from above. The small diameter hole 28b penetrates the lower part of the connecting member 28 and has a small diameter. The upper end of the guide shaft portion 26 is inserted into the small diameter hole 28b from below so as to be slidable in the vertical direction. In this embodiment, the upper cover 27, the connecting member 28, and the bearing member 34 are inserted in a nested manner, whereby the electric actuator 40 is installed on the upper surface of the valve body 12.

[0038] The guide shaft portion 26 of the adjustment member 24 passes through the bottom plate portion 27d of the top lid main body 27a from the upper portion of the valve chamber 13, and its upper end portion is inserted into the small diameter hole 28b through the stopper arrangement space S. The stopper member 29 is installed in the middle portion of the guide shaft portion 26 (the portion extending into the stopper arrangement space S). This stopper member 29 is a flat C-shaped ring member fixed to the guide shaft portion 26 so as to protrude horizontally (in a flange shape) from the outer circumferential surface of the guide shaft portion 26, and serves to physically (mechanically) stop the adjustment member 24 by abutting against the upper surface of the top lid bottom plate portion 27d (the bottom surface of the connecting member accommodating hole 27c) when the adjustment member 24 is moved downward by the electric actuator 41, as will be described in detail later.

[0039] The stopper member 29 may have any shape or structure as long as it has the function of mechanically stopping the adjustment member 24. For example, the stopper member 29 may be an O-shaped ring-shaped member that protrudes outward from the outer circumferential surface of the guide shaft portion 26, or a rod-shaped (pin-shaped) member or plate-shaped member that penetrates the guide shaft portion 26 and has one or both ends protruding from the outer circumferential surface of the guide shaft portion 26.

[0040] The electric actuator 40 is composed of a stepping motor 41, a speed reduction mechanism (paradox planetary gear speed reduction mechanism) 54 that reduces the speed of rotation by the stepping motor 41, and a transmission mechanism (screw feed mechanism 36) that converts the reduced rotational motion into linear motion and transmits it to the bellows 21 (the guide shaft portion 26 of the adjustment member 24). The details are as follows.

[0041] A cylindrical can 56 with no bottom and a lid (the bottom is open and the top is closed) is joined to the upper end of the connecting member 28 via a ring-shaped base plate 57. The stator 42 is provided on the outer periphery (outside) of the can 56, while the rotor 47 is rotatably installed on the inner periphery (inside) of the can 56. The rotor 47 and the stator 42 constitute the stepping motor 41.

[0042] The stator 42 arranged outside the can 56 includes a yoke 43, a bobbin 44, a coil 45, and a resin molded cover 46. The rotor 47 arranged inside the can 56 is configured by integrally connecting a cylindrical rotor member 47a made of a magnetic material and a sun gear member 48 made of a resin material. The shaft 38 is inserted into the center of the sun gear member 48, and the upper part of the shaft 38 is supported by a support member 39 arranged inside the top of the can 56.

[0043] The sun gear 48a of the sun gear member 48 meshes with a plurality of planetary gears 49 rotatably supported on a shaft 50 provided on a carrier 51 placed on the bottom surface of the output gear 53. The upper part of the planetary gear 49 meshes with an annular ring gear (internal tooth fixed gear) 55 attached to the upper part of a cylindrical member 37 fixed to the upper part of the connecting member 28, and the lower part of the planetary gear 49 meshes with an internal tooth gear 52 of an annular output gear 53. The number of teeth of the ring gear 55 and the number of teeth of the internal tooth gear 52 of the output gear 53 are slightly different, so that the rotation speed of the sun gear 48a is reduced at a large reduction ratio and transmitted to the output gear 53. Incidentally, these gear mechanisms (sun gear 48a, planetary gear 49, ring gear 55 and output gear 53) constitute a speed reduction mechanism (paradise planetary gear speed reduction mechanism) 54 that reduces the rotation speed of the stepping motor 41 described above.

[0044] A cylindrical bearing member 34 is fitted into the upper part of the connecting member 28 and is fixed to the connecting member 28 by crimping. The output gear 53 is in slidable contact with the upper surface of the bearing member 34. The upper part of a stepped cylindrical output shaft 58 is press-fitted into the center of the bottom of the output gear 53, and the lower part of the output shaft 58 is rotatably inserted into a fitting hole 34a formed in the central upper surface part of the bearing member 34. The lower end of the shaft 38 is rotatably fitted into the upper part of the output shaft 58.

[0045] A female thread portion 34b is formed at the lower center portion of the bearing member 34, and a male thread portion 35a formed on the outer circumferential surface of the screw drive member 35 is screwed into this female thread portion 34b. The bearing member 34 (female thread portion 34b) and the screw drive member 35 (male thread portion 35a) constitute the above-mentioned screw feed mechanism 36, i.e., a transmission mechanism that converts the rotational motion supplied from the stepping motor 41 via the reduction mechanism 54 into linear motion in the vertical direction and transmits it to the bellows 21 (the guide shaft portion 26 of the adjustment member 24).

[0046] Here, the output gear 53 rotates at a constant position in the vertical direction without moving up and down, and a flat screwdriver-shaped plate-like portion 35b provided at the upper end of the screw drive member 35 is inserted into a slit-shaped fitting groove 58a provided at the lower end of an output shaft 58 connected to the output gear 53 to transmit the rotational motion of the output gear 53 to the screw drive member 35. Although the output gear 53 does not move up and down when the output gear 53 (rotor 47) rotates due to the plate-like portion 35b provided on the screw drive member 35 sliding up and down within the fitting groove 58a of the output shaft 58, the screw drive member 35 moves linearly up and down by the screw feed mechanism 36.

[0047] The linear motion of this screw drive member 35 is transmitted to the guide shaft portion 26 via a ball joint 31 consisting of a ball 33 and a ball seat 32 fitted into a fitting hole 26a provided in the center of the upper surface of the guide shaft portion 26. The guide shaft portion 26 (and therefore the adjustment member 24) moves in the vertical direction while being guided by the small diameter hole 28b of the connecting member 28 and the bottom hole 27e of the upper lid bottom plate portion 27d.

[0048] Here, to briefly explain the operation of the regulating valve 11 according to this embodiment, when the refrigerant pressure in the evaporator connected to the inflow passage 14 via a pipe becomes smaller than the set load of the pressure-sensitive bellows 21 that biases the valve body 17, the valve body 17 is pushed by the biasing force of the pressure-sensitive bellows 21 and moves toward the valve seat 16, thereby decreasing the flow rate of the refrigerant. Conversely, when the refrigerant pressure in the evaporator becomes larger than the set load of the pressure-sensitive bellows 21 that biases the valve body 17, the valve body 17 is pushed by the refrigerant pressure in the inflow passage 14 (inside the evaporator) and moves in a direction away from the valve seat 16, thereby increasing the flow rate of the refrigerant.

[0049] In order to incorporate the regulating valve 11 according to this embodiment into an air conditioning system or the like and to be able to change the set load of the pressure-sensitive bellows 21 using the stopper member 29, for example, the following process is carried out in advance.

[0050] First, an initialization operation is performed. Specifically, the electric actuator 40 (stepping motor 41) is driven to move the adjustment member 24 downward to the initial position, that is, until the stopper member 29 comes into contact with the bottom surface of the connecting member accommodating hole 27c (the upper surface of the upper lid bottom plate portion 27d) as shown in FIG. 3, and the adjustment member 24 is stopped.

[0051] Next, while supplying a refrigerant (which may be air or the like) to the inflow passage 14, the electric actuator 40 is driven to move the adjustment member 24 upward from the initial position until the pressure in the inflow passage 14 reaches a first pressure value (first evaporation pressure). During this time, the number of drive pulses of the stepping motor is counted, and the count value (number of pulses) is stored as a first set value.

[0052] After performing the initialization operation again (after returning the adjustment member 24 to the initial position), the electric actuator 40 is driven while supplying refrigerant (or air, etc.) to the inflow passage 14 in the same manner, and the adjustment member 24 is moved upward until the pressure in the inflow passage 14 reaches a second pressure value (second evaporation pressure) different from the first pressure value (first evaporation pressure). During this time, the number of drive pulses of the stepping motor 41 is counted, and the count value (number of pulses) is stored as a second set value.

[0053] Then, the first and second set values ​​obtained by the above operations are stored in a memory device provided in a control unit that controls a system that uses the regulating valve 11 of this embodiment (for example, an air conditioning system such as a car air conditioner or a room air conditioner, or a refrigeration system such as a freezer refrigerator), and the electric actuator 40 can be driven by the control unit, making it possible to set the refrigerant pressure in the evaporator to the first evaporation pressure and the second evaporation pressure depending on the operating conditions of the system, etc.

[0054] Similarly, by measuring the number of pulses resulting in a pressure value (evaporation pressure) of 3 or more, i.e., the third pressure value (third evaporation pressure), the fourth pressure value (fourth evaporation pressure), the fifth pressure value (fifth evaporation pressure), ..., and saving these as the third set value, the fourth set value, the fifth set value, ..., respectively, it becomes possible to switch the evaporator setting to an evaporation pressure of 3 or more based on the set value of 3 or more of the regulating valve 11.

[0055] The above-mentioned respective set values ​​(each evaporation pressure) may be any value according to the system configuration, operating conditions, etc. An example in which the regulating valve 11 of this embodiment is incorporated into an air conditioning system will be described later, and the above-mentioned first set value can be, for example, a standard set value described later, the second set value can be, for example, a high temperature side set value described later, and the third set value can be, for example, a low temperature side set value described later.

[0056] In addition, when the regulating valve 11 of this embodiment is used in a car air conditioner, the above-mentioned set values ​​are stored in a memory device (such as a ROM (Read Only Memory), a RAM (Random Access Memory), or a flash memory) mounted on a LIN (Local Interconnect Network) board or provided separately. In addition, when used in a room air conditioner, the information can be stored in a similar storage device mounted on the control board of the room air conditioner or separately provided.

[0057] FIG. 4 shows a building air conditioning system 61 equipped with an evaporative pressure regulating valve 11 according to this embodiment. As shown in the figure, this air conditioning system 61 includes each device that constitutes a refrigeration cycle, namely, a compressor 62 that compresses a refrigerant, an outdoor heat exchanger 63 installed outdoors, a first indoor heat exchanger 64 installed in a first living room, a second indoor heat exchanger 65 installed in a second living room, a first expansion valve 66 connected to the inlet side piping of the first indoor heat exchanger 64 (between the outdoor heat exchanger 63 and the first indoor heat exchanger 64), a second expansion valve 67 connected to the inlet side piping of the second indoor heat exchanger 65 (between the outdoor heat exchanger 63 and the second indoor heat exchanger 65), a first pressure regulating valve 68 connected to the outlet side piping of the first indoor heat exchanger 64 (between the first indoor heat exchanger 64 and the compressor 62), and a second pressure regulating valve 69 connected to the outlet side piping of the second indoor heat exchanger 65 (between the second indoor heat exchanger 65 and the compressor 62). The first pressure regulating valve 68 and the second pressure regulating valve 69 are both formed of the pressure regulating valve 11 according to this embodiment.

[0058] The system 61 further includes a control unit 71 that controls the settings of the pressure regulating valves 68, 69 (the biasing force of the pressure-sensitive bellows 21), a setting storage unit (storage device) 72 that stores the setting values, and motor drive circuits 73, 74 that include a pulse generator and drive the electric actuator 40 (stepping motor 41). The control unit 71 and setting storage unit 72 are mounted on a control board 70 of the air conditioning system 61.

[0059] The setting memory unit 72 also stores three (three types) setting values, namely, a standard setting value (which is referred to as the "standard value" and the setting based on this standard value is referred to as the "standard setting"), a high temperature side setting value (which is referred to as the "high temperature side setting") for shifting the temperature to a higher temperature than the standard setting (by strengthening the spring force of the pressure-sensitive bellows 21 to increase the refrigerant pressure in the evaporator, i.e., by positioning the adjustment member 24 lower than the standard setting), and conversely, a low temperature side setting value (which is referred to as the "low temperature side setting") for shifting the temperature to a lower temperature than the standard setting (by weakening the spring force of the pressure-sensitive bellows to lower the refrigerant pressure in the evaporator, i.e., by positioning the adjustment member higher than the standard setting).

[0060] 4 shows a state in which cooling operation is performed, and the refrigerant discharged from the compressor 62 flows through a path that returns to the compressor 62 via the outdoor heat exchanger 63, the first expansion valve 66, the first indoor heat exchanger 64, and the first pressure regulating valve 68 in this order, and a path that returns to the compressor 62 via the outdoor heat exchanger 63, the second expansion valve 67, the second indoor heat exchanger 65, and the second pressure regulating valve 69 in this order, with the outdoor heat exchanger 63 functioning as a condenser, and the first indoor heat exchanger 64 and the second indoor heat exchanger 65 both functioning as evaporators. Also, the first pressure regulating valve 68 connected to the outlet piping of the first indoor heat exchanger 64 and the second pressure regulating valve 69 connected to the outlet piping of the second indoor heat exchanger 65 are both set to standard settings.

[0061] In such a system, if the cooling load of each room (each indoor heat exchanger 64, 65) changes significantly during cooling operation, for example, if the number of occupants in the first room increases significantly, causing a large cooling load on the first indoor heat exchanger 64, while the number of occupants in the second room decreases significantly, causing a small cooling load on the second indoor heat exchanger 65, in system 61 of Figure 4, by setting the second pressure regulating valve 69 to the high temperature setting while changing the setting of the first pressure regulating valve 68 to the low temperature setting, it is possible to more reliably prevent frost formation on the second indoor heat exchanger 65 and to avoid or suppress a situation in which cooling capacity is insufficient in the first room, which has a large cooling load.

[0062] Specifically, the control unit 71 initializes the second pressure regulating valve 69 by driving the stepping motor 41 via the motor driving circuit 74 (moves the regulating member 24 to the initial position), reads out the high temperature side set value from the set value storage unit 72, and drives the stepping motor 41 by sending a drive pulse corresponding to the high temperature side set value to the second pressure regulating valve 69 via the motor driving circuit 74. As a result, the regulating member 24 moves from the initial position to the high temperature side set position, and the second pressure regulating valve 69 is set to the high temperature side. Similarly, the control unit 71 initializes the first pressure regulating valve 68 by driving the stepping motor 41 via the motor driving circuit 73, reads out the low temperature side set value from the set value storage unit 72, and drives the stepping motor 41 by sending a drive pulse corresponding to the low temperature side set value to the first pressure regulating valve 68 via the motor driving circuit 73. As a result, the regulating member 24 moves from the initial position to the low temperature side set position, and the first pressure regulating valve 68 is set to the low temperature side.

[0063] Such setting changes by the control unit 71 may be performed automatically, that is, by the control unit 71 based on a detection signal from a sensor (e.g., a temperature sensor that detects the air temperature in the room or a human presence sensor that detects the number of people present in the room (not shown)), or may be performed manually, that is, by input operations from an input device (e.g., a remote control (a so-called remote controller) (not shown)).

[0064] Also, although FIG. 4 shows only two indoor heat exchangers, more (three or more) indoor heat exchangers (including expansion valves and pressure regulating valves) may be provided, and it is possible to make it possible for these indoor heat exchangers to be controlled (settings changed) by the control unit 71 in the same way as the first indoor heat exchanger (first pressure regulating valve) and the second indoor heat exchanger (second pressure regulating valve).

[0065] Fig. 12 shows an example of a processing flow for optimally controlling the air conditioning of each room in an air conditioning system such as that shown in Fig. 4. In this example, in order to keep the difference (temperature difference) between the actual temperature (actual temperature) in the room and the set temperature within a certain temperature range, an upper threshold (upper limit of the temperature difference) and a lower threshold (lower limit of the temperature difference) are stored in advance in the set value storage unit in addition to the standard value (standard set value), high temperature set value, and low temperature set value, and the control unit is made capable of acquiring the set temperature and actual temperature of each room (for example, via an indoor communication line).

[0066] In the process by the control unit, first (for example, when the air conditioning system is turned on), the control unit reads the standard setting value from the setting value storage unit and sets the regulating valve of each room to the standard setting (step S101). Next, the control unit obtains the set temperature of each room (step S102) and the actual temperature of each room (step S103).

[0067] The control unit then compares the difference (temperature difference) between the actual temperature and the set temperature with the upper threshold for each room, and if the temperature difference is greater than the upper threshold, changes the adjustment valve for that room (where the temperature difference is greater than the upper threshold) to the lower temperature setting (step S106). For example, if the upper threshold is "3°C" and the lower threshold is "-3°C," and the set temperature is "22°C" and the actual temperature is "26°C," the temperature difference (+4°C) is greater than the upper threshold (3°C), so the control unit will change to the lower temperature setting.

[0068] On the other hand, if the temperature difference does not exceed the upper threshold (if there is no room where the temperature difference exceeds the upper threshold), and after the setting change to the lower temperature side (step S106) is completed, the temperature difference is compared with the lower threshold for each room (step S105). If the temperature difference is smaller than the lower threshold, the adjustment valve for that room (where the temperature difference is smaller than the lower threshold) is changed to the higher temperature side setting (step S107). For example, if the upper threshold is "3°C" and the lower threshold is "-3°C", and the set temperature is "25°C" and the actual temperature is "20°C", the temperature difference (-5°C) is smaller than the lower threshold (-3°C), so the control unit will change to the higher temperature side setting.

[0069] On the other hand, if the temperature difference is not smaller than the lower threshold (if there is no room where the temperature difference is smaller than the lower threshold), and after the change in setting to the higher temperature side (step S107) is completed, the process returns to step S102, in which the set temperature of each room is obtained.

[0070] The control unit repeats the above-mentioned processes (steps S102 to S107) at regular time intervals (e.g., every 5 minutes or every 10 minutes, etc.). This makes it possible to realize good air conditioning control in which the actual room temperature in each room falls within a certain error range from the set temperature (between the upper and lower thresholds).

[0071] In the above example, one threshold value and one set value are provided for each of the high and low temperature sides, allowing the biasing force to be adjusted in one step for each of the high and low temperature sides. However, it is also possible to change the biasing force of the pressure-sensitive bellows in multiple steps by setting multiple threshold values ​​and set values ​​for each of the high and low temperature sides, allowing for more precise control.

[0072] Furthermore, instead of temperature, it is also possible to use a human presence sensor to change the setting of the pressure-sensitive bellows' force according to the number of people in the room, that is, instead of the temperature difference, for example, based on the difference in number of people (the difference between the actual number of people in the room and the predetermined capacity of the room).

[0073] FIG. 5 shows a car air conditioning system 81 equipped with an evaporative pressure regulating valve according to this embodiment, and includes each device constituting a heat pump cycle, namely, a compressor 62, a first interior heat exchanger 82 installed in the vehicle cabin, a second interior heat exchanger 83 installed in the vehicle cabin, an exterior heat exchanger 84 installed outside the vehicle cabin, and an inlet side pipe of the second interior heat exchanger 83 (between the first interior heat exchanger 82 and the second interior heat exchanger 83). The exhaust duct 64 is provided with a first expansion valve 66 connected to the inlet side piping of the exterior heat exchanger 84 (between the first interior heat exchanger 82 and the exterior heat exchanger 84), a second expansion valve 67 connected to the inlet side piping of the exterior heat exchanger 84 (between the first interior heat exchanger 82 and the exterior heat exchanger 84), a first pressure regulating valve 68 connected to the outlet side piping of the second interior heat exchanger 83 (between the second interior heat exchanger 83 and the compressor 62), and a second pressure regulating valve 69 connected to the outlet side piping of the exterior heat exchanger 84 (between the exterior heat exchanger 84 and the compressor 62).

[0074] 4 in that the first pressure regulating valve 68 and the second pressure regulating valve 69 are both pressure regulating valves 11 according to this embodiment, and the system 81 is equipped with a control unit 71 that controls the settings of the pressure regulating valves 68, 69, a setting storage unit 72 that stores setting values, and motor drive circuits 73, 74 that include a pulse generator and drive the electric actuator 40 (stepping motor 41). Note that the control unit 71 and the setting storage unit 72 are mounted on a LIN (Local Interconnect Network) board 85 in this embodiment. Furthermore, in this system 81, the standard value, the high temperature side setting value, and the low temperature side setting value are also stored in the setting storage unit in advance, and both the first pressure regulating valve 68 and the second pressure regulating valve 69 are initially set to the standard settings.

[0075] The refrigerant discharged from the compressor 62 flows through a path that passes through the first interior heat exchanger 82, the first expansion valve 66, the second interior heat exchanger 83, and the first pressure regulating valve 68 in this order and returns to the compressor 62, and through the first interior heat exchanger 82, the second expansion valve 67, the exterior heat exchanger 84, and the second pressure regulating valve 69 in this order and returns to the compressor 62, with the first interior heat exchanger 82 functioning as a condenser, and the second interior heat exchanger 83 and the exterior heat exchanger 84 both functioning as evaporators. The second interior heat exchanger 83 functioning as an evaporator is disposed in the air passage of the warm air that has been heated by heat exchange in the first interior heat exchanger 82, thereby exerting a dehumidifying function.

[0076] In such a system 81, assuming that a heating and dehumidifying operation is performed to defog the vehicle windows simultaneously with heating during rain or snow in winter, for example, in the system 81 shown in Fig. 5, by changing the setting of the first pressure regulating valve 68 to a lower temperature, the second interior heat exchanger 83 can be cooled further, thereby enhancing the dehumidifying function. Also, by changing the setting of the second pressure regulating valve to a higher temperature, it becomes possible to more reliably prevent frost from forming on the exterior heat exchanger 84, which is installed outside the vehicle cabin and exposed to the outside air, and is therefore prone to frost.

[0077] Specifically, the control unit 71 initializes the first pressure regulating valve by driving the stepping motor 41 via the motor driving circuit 73 (moves the regulating member 24 to the initial position), reads out the low temperature side set value from the set value storage unit 72, and drives the stepping motor 41 by sending a drive pulse corresponding to the low temperature side set value to the first pressure regulating valve 68 via the motor driving circuit 73. As a result, the regulating member 24 moves from the initial position to a position set on the low temperature side, and the first pressure regulating valve 68 is set on the low temperature side. In addition, the control unit 71 initializes the second pressure regulating valve by driving the stepping motor 41 via the motor driving circuit 74, reads out the high temperature side set value from the set value storage unit 72, and drives the stepping motor 41 by sending a drive pulse corresponding to the high temperature side set value to the second pressure regulating valve 69 via the motor driving circuit 74. As a result, the regulating member 24 moves from the initial position to a position set on the high temperature side, and the second pressure regulating valve 69 is set on the high temperature side.

[0078] Second Embodiment A pressure regulating valve according to a second embodiment of the present invention will be described with reference to Figures 6 to 8. As shown in Figures 6 to 8, a regulating valve 91 according to this embodiment includes the valve body 12, valve element 17, and pressure-sensitive bellows 21 similar to those of the regulating valve 11 according to the first embodiment, and has a valve chamber 13, a valve seat 16, an inlet passage 14, and an outlet passage 15, but uses an electromagnetic actuator 92 instead of an electric actuator as an actuator for displacing the adjustment member 24. Hereinafter, the same components as those of the regulating valve 11 according to the first embodiment will be denoted by the same reference numerals, and duplicated explanations will be omitted, with differences being mainly described.

[0079] The electromagnetic actuator 92 has a solenoid 93, a plunger (movable iron core) 97, and a thrust transmission member 98 that connects the plunger 97 and the adjustment member 24 and transmits the up and down movement of the plunger 97 to the adjustment member 24 via the ball joint 31 (ball 33 and ball seat 32). The solenoid 97 has an excitation coil 96 and an attractor (fixed iron core) 95 that attracts the plunger 97. The excitation coil 96 has a bobbin 94 with a cylindrical portion in the center, and an upper part of the attractor 95 (attractor main body 95a) and the plunger 97 are arranged in a state of being housed in a sleeve 99 within the cylindrical portion of the bobbin 94.

[0080] The aspirator 95 comprises a cylindrical aspirator body 95a that attracts the plunger 97 and a disk-shaped top lid 95b that closes the top of the valve chamber 13, and the aspirator body 95a and the top lid 95b are integrally formed. The top lid 95b is fixed to the valve body 12 by screwing it into the top opening 12a of the valve body 12, similar to the top lid 27 of the first embodiment, thereby closing the top of the valve chamber 13.

[0081] A through hole 95c extending in the vertical direction is formed in the center of the suction element 95, a thrust transmission member 98 is inserted into the upper part of the through hole 95c so as to be slidable in the vertical direction, and a guide shaft portion 26 of the adjustment member 24 is inserted into the lower part of the through hole 95c so as to be slidable in the vertical direction. Furthermore, a ball joint 31 consisting of a ball 33 and a ball seat 32 is interposed between the thrust transmission member 98 and the guide shaft portion 26, so that the downward thrust of the thrust transmission member 98 caused by the descent of the plunger 97 is transmitted to the guide shaft portion 26, and the upward elastic force of the pressure-sensitive bellows 21 (reaction force of the biasing force on the valve body 17) and the upward force of the guide shaft portion 26 caused by the upward movement of the valve body 17 are transmitted to the thrust transmission member 98.

[0082] The regulating valve 91 of the present embodiment is provided with an adjustment member 24 on the upper surface of the bellows 21 similar to that of the first embodiment, but does not have a stopper member on the guide shaft portion 26.

[0083] When no current is applied to the excitation coil 96, the elastic force of the pressure-sensitive bellows 21 presses the valve body 17 against the valve seat 16, presses the adjustment member 24 (flange portion 25) against the underside of the upper cover portion 95b, and presses the plunger 97 against the underside of the top plate portion of the sleeve 99, as shown in FIG. 6 (this position of the plunger 97 is referred to as the "upper limit position").

[0084] On the other hand, when current is applied to the exciting coil 96, the attractor 95 attracts the plunger 97 against the elastic force of the pressure-sensitive bellows 21 as shown in Fig. 7, and the adjustment member 24 is pushed downward via the thrust transmission member 98 and the ball joint 31. The position of the plunger shown in Fig. 7 is referred to as the "lower limit position."

[0085] Here, the stop position of the plunger 97, i.e., the vertical position of the adjustment member 24, is determined by the balance between the upward elastic force of the pressure-sensitive bellows 21 (reaction force of the urging force on the valve body 17) and the attractive force of the solenoid 93 (attractor 95) (the magnitude of the drive current supplied to the solenoid 93). In other words, if the attractive force (strength of magnetic force) of the attractor 95 is sufficiently large, the plunger 97 will descend to the lower limit position where it collides with the attractor as shown in Fig. 7, but if the attractive force of the attractor 95 is weakened by adjusting the drive current supplied to the excitation coil 96, it is possible to stop the plunger 97 (adjustment member 24) at any intermediate position between the upper limit position shown in Fig. 6 and the lower limit position shown in Fig. 7 (see Fig. 8).

[0086] Therefore, as in the first embodiment, the magnitude of the drive current at which the pressure in the inflow passage 14 becomes a first pressure value (first evaporation pressure) is measured and set as a first setting value, and the magnitude of the drive current at which the pressure in the inflow passage 14 becomes a second pressure value (second evaporation pressure) is measured and set as a second setting value, and these first and second setting values ​​are stored in a setting value memory unit of the system (air conditioning system, etc.) and made available to the control unit, and it is possible to change the setting of the pressure regulating valve 91 by changing the magnitude of the current supplied by the control unit to the excitation coil 96 based on each of the setting values.

[0087] The above set values ​​are not limited to two, and setting changes can be made based on three or more set values ​​(a third set value, a fourth set value, . . . ) as in the first embodiment.

[0088] Although the embodiments of the present invention have been described above, the present invention is not limited to these, and it will be apparent to those skilled in the art that various modifications can be made within the scope of the claims.

[0089] For example, in the first embodiment, initialization was performed by abutting the stopper member 29 against the bottom surface of the connecting member accommodating hole 27c (the upper surface of the upper lid bottom plate portion 27d), but since the purpose of this operation can be achieved as long as the adjustment member 24 can be mechanically stopped, the location where the stopper member 29 is abutted may be another location (another member or part) within the adjustment valve. [Explanation of symbols]

[0090] 11,91 Evaporation pressure regulating valve 12 Valve body 12a Top opening 13 Valve chamber 14 Inflow channel 15 Outflow channel 16 Valve seat 17 Valve body 18 Connecting plate 21 Pressure-sensitive bellows 22 Bellows body 23 Compression coil spring 24 Adjustment member 25 Flange 26 Guide shaft 26a Fitting hole 27 Top lid 27a Top lid body 27b Flange part 27c Connection member accommodation hole 27d Top cover bottom plate 27e bottom hole 28 Actuator connecting member 28a Large diameter hole 28b Small diameter hole 29 Stopper member 31 Ball joint 32 Ball seat 33 Ball 34 Bearing materials 34a Insert hole 34b Female thread 35 Screw drive member 35a Male thread 35b Plate-shaped part 36 Screw feed mechanism 37 Cylindrical member 38 Shaft 39 Support member 40 Electric Actuator 41 Stepping motor 42 Stator 43 York 44 Bobbin 45 Coil 46 Resin molded cover 47 Rotor 47a Rotor member 48 Sun gear parts 48a Sun Gear 49 Planetary Gear 50 Shaft 51 Career 52 Internal gear 53 Output gear 54 Reduction mechanism (paradoxical planetary gear reduction mechanism) 55 Ring gear (internal tooth fixed gear) 56 Can 57 Base Plate 58 Output shaft 58a Fitting groove 61 Building Air Conditioning Systems 62 Compressor 63 Outdoor heat exchanger 64 1st indoor heat exchanger 65 Second indoor heat exchanger 66 First expansion valve 67 Second expansion valve 68 First pressure regulating valve 69 Second pressure regulating valve 70 Control Board 71 Control Unit 72 Setting storage unit (storage device) 73,74 Motor drive circuit 81 Car air conditioning system 82 No. 1 cabin heat exchanger 83 2nd vehicle interior heat exchanger 84 Vehicle outdoor heat exchanger 85 LIN Board 92 Electromagnetic Actuator 93 Solenoid 94 Bobbin 95 Attractor 95a Attractor main body 95b Upper lid part 95c through hole 96 Excitation coil 97 Plunger (movable core) 98 Thrust transmission member 99 Sleeve S Stopper placement space

Claims

1. a valve body having a valve chamber communicating with an inlet passage for introducing a refrigerant and an outlet passage for discharging the refrigerant; a valve element that moves toward and away from a valve seat between a valve closed state in which the valve element is seated on a valve seat formed in the valve chamber and an open state in which the valve element is spaced from the valve seat to change a flow rate of the refrigerant; a pressure-sensitive member that biases the valve body toward the valve seat and expands and contracts in response to pressure applied to the valve body by the refrigerant flowing in from the inlet passage, thereby allowing the valve body to move back and forth; an adjustment means for adjusting the biasing force of the pressure-sensitive member against the valve body; an actuator for driving the adjustment means; A pressure regulating valve comprising: When the end of the pressure-sensitive member that is farther from the valve body is referred to as a base end, The adjustment means includes an adjustment member provided at a proximal end of the pressure-sensitive member, The actuator changes the biasing force by moving the adjustment member in a direction in which the pressure-sensitive member expands or contracts, The adjustment means is a stopper member that mechanically stops the movement of the adjustment member by the actuator and can be used as a starting point when setting the biasing force; Equipped with The actuator comprises: an electric motor for driving the adjusting means; a screw feed mechanism that converts the rotational motion supplied from the electric motor into a linear motion via a reduction mechanism; Including, The screw feed mechanism includes: a bearing member having a female thread portion and fixed to the valve body; a driving member having a male threaded portion that is screwed into the female threaded portion and that rotates and moves linearly; Equipped with the adjustment member includes a guide shaft portion that moves linearly without rotating as a result of the linear motion of the drive member being transmitted thereto; The stopper member is fixed to the guide shaft portion. A pressure regulating valve.

2. The electric motor is a stepping motor. The pressure regulating valve according to claim 1 .

3. A control device for controlling the actuator is further provided. The control device includes: A storage unit that stores two or more set values ​​related to the biasing force; A control unit that drives the adjustment means via the actuator; Equipped with The control unit drives the adjustment means via the actuator based on the set value previously stored in the storage unit, and changes the biasing force of the pressure-sensitive member. The pressure regulating valve according to claim 1 or 2.

4. When the end of the pressure-sensitive member that is farther from the valve body is referred to as a base end, The adjustment means includes an adjustment member provided at a proximal end of the pressure-sensitive member, the two or more set values ​​are different from each other and are information about the position of the adjustment member in the extension / contraction direction of the pressure-sensitive member, The control unit changes the biasing force by moving the adjustment member in the expansion / contraction direction of the pressure-sensitive member via the actuator. The pressure regulating valve according to claim 3.

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