Electronically controlled regulator

Abstract

The regulator is designed to automatically maintain various specified discharge pressures while being able to accommodate fluctuations in the required flow rate. [Solution] In a regulator that reduces and adjusts the pressure of a high-pressure fluid introduced from an inlet 11 using a pressure regulating valve 20 and discharges it from a discharge port 12 as a reduced-pressure fluid at a set pressure, the discharge pressure adjustment means has a valve shaft moving structure that is driven by an electric motor 30 to move the valve shaft 21 and change the distance between the valve body 22 and the valve seat 23. Based on the value of a pressure sensor that detects the pressure of the reduced-pressure fluid, the electric motor 30 operates the valve shaft moving structure to open and close the pressure regulating valve 20 so that the pressure of the reduced-pressure fluid is maintained at the set pressure, resulting in an electronically controlled regulator 1A.

Description

TECHNICAL FIELD

[0001] The present invention relates to a regulator that discharges high-pressure fluid such as gas fuel while reducing and adjusting the pressure to a predetermined level, and more particularly to an electronically controlled regulator that adjusts the pressure of the discharged fluid through electronic control.

BACKGROUND ART

[0002] As regulators that reduce the pressure of high-pressure fluid to a predetermined level and discharge the same, those for gas fuel described in, for example, Japanese Patent No. 2667114 (Patent Document 1) and Japanese Patent Laid-Open No. 2011-256759 (Patent Document 2) are well known. This regulator includes a valve shaft coaxially provided with a valve element, and a donut-shaped valve seat having a seat surface through which a valve hole penetrates at the center and with which the valve element comes into close contact, and has a structure in which high-pressure fluid such as CNG that flows in from the inlet of the body flows into the pressure reducing chamber through the gap between the valve element and the valve seat in the open state of the valve element, is pressure-regulated, and then discharged.

[0003] Then, when the pressure of the fluid in the pressure reducing chamber reaches or exceeds a predetermined pressure, the pressure pushes up the diaphragm against the biasing force of the pressure regulating spring, lifts the valve element connected to the diaphragm to close the valve seat, and when the pressure of the fluid in the pressure reducing chamber falls below the predetermined pressure, the biasing force of the pressure regulating spring lowers the diaphragm to repeat the operation of separating the valve element from the valve seat, thereby adjusting the fluid to a desired pressure, and the high-pressure fluid is discharged while being reduced and adjusted to the predetermined pressure by the balance between the pressure in the pressure reducing chamber and the biasing force of the pressure regulating spring.

[0004] Furthermore, as described in Japanese Patent Publication No. 2007-146875 (Patent Document 3) and Japanese Patent Publication No. 2019-067216 (Patent Document 4), for example, the regulator has a valve body coaxially mounted and a valve stem through which fluid can pass, and a valve seat having a seat surface that tightly contacts the valve body. The inside of the body is airtightly divided into a primary pressure chamber (reduced pressure chamber), a back pressure chamber (atmospheric pressure chamber), and a secondary pressure chamber (pressure regulating chamber) by a piston part integrated with the valve stem. High-pressure fluid such as CNG that flows in from the inlet of the body flows into the secondary pressure chamber through a passage formed in the valve stem when the valve body is open, is pressure regulated, and then discharged.

[0005] When the fluid pressure in the secondary pressure chamber exceeds a predetermined pressure, this pressure pushes the piston upward against the biasing force of the pressure regulating spring, lifting the valve body connected to the piston and closing the valve seat. When the fluid pressure in the secondary pressure chamber falls below the predetermined pressure, the piston descends due to the biasing force of the pressure regulating spring, separating the valve body from the valve seat. This process is repeated to adjust the fluid to the desired pressure. The high-pressure fluid is discharged while being reduced and adjusted to a predetermined pressure by balancing the pressure in the secondary pressure chamber and the biasing force of the pressure regulating spring.

[0006] However, in such conventional regulator pressure reduction structures, the fluid discharge pressure from the regulator mechanically depends on the load of the pressure regulating spring, so it is necessary to prepare a pressure regulating spring in advance for each specified discharge pressure. Furthermore, in the case of regulators used in vehicle fuel supply systems, since the pressure regulating spring is fixed in advance at a specified set height, the pressure drop becomes large when the engine flow rate is high and small when the flow rate is low, resulting in a problem where the discharge pressure range and flow rate range are mechanically limited.

[0007] On the other hand, Japanese Utility Model Publication No. 59-160842 (Patent Document 5) proposes a pressure regulating mechanism for an LPG regulator equipped with a primary diaphragm chamber and a secondary diaphragm chamber, which includes a stepping motor that is pulse-controlled in response to an output signal from a pressure sensor installed in the primary diaphragm chamber as a biasing force adjustment means for adjusting the biasing force of the pressure regulating spring in the primary diaphragm chamber.

[0008] In this way, the pressure regulating mechanism equipped with an electronically controlled stepping motor weakens the biasing force of the pressure regulating spring when the pressure in the primary diaphragm chamber becomes higher than a preset pressure, and strengthens the biasing force of the pressure regulating spring when the pressure in the primary diaphragm chamber becomes lower than a preset pressure, thereby enabling the pressure in the primary diaphragm chamber to be maintained at a desired pressure.

[0009] However, in this regulator, only the primary diaphragm chamber can be adjusted and maintained to the desired pressure. The pressure of the fuel discharged from the secondary diaphragm chamber depends on the pressure regulating spring located in that chamber. Therefore, it remains difficult to set various discharge pressures with a single type of regulator, and the problem of mechanically limited discharge pressure range and flow rate range has not been resolved. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 2667114 [Patent Document 2] Japanese Patent Publication No. 2011-256759 [Patent Document 3] Japanese Patent Publication No. 2007-146875 [Patent Document 4] Japanese Patent Publication No. 2019-067216 [Patent Document 5] Japanese Utility Model Publication No. 59-160842 [Overview of the project] [Problems that the invention aims to solve]

[0011] The present invention aims to solve the above-mentioned problems, and its objective is to enable a regulator to automatically maintain various specified discharge pressures while being able to respond to fluctuations in the required flow rate. [Means for solving the problem]

[0012] Therefore, the present invention provides an electronically controlled regulator comprising a pressure regulating valve comprising a valve stem coaxially provided inside a body having an inlet and a discharge port, a valve seat having a seat surface into which the valve body can make close contact, and a discharge pressure adjusting means for adjusting the discharge pressure of the fluid by changing the distance between the valve body and the valve seat by moving the valve stem back and forth, wherein the pressure regulating valve reduces and adjusts the pressure of a high-pressure fluid introduced from the inlet and discharges it from the discharge port as a reduced-pressure fluid of a set pressure, wherein the discharge pressure adjusting means comprises an electric motor and a valve stem moving structure that changes the distance between the valve body and the valve seat by moving the valve stem in the axial direction driven by the electric motor, and the electric motor operates the valve stem moving structure to open and close the pressure regulating valve so that the pressure of the reduced-pressure fluid maintains the set pressure, based on the value of a pressure sensor that is arranged in series or parallel with the discharge port and detects the pressure of the reduced-pressure fluid.

[0013] Thus, instead of adjusting the discharge pressure with a pressure-regulating spring, this system maintains the discharge pressure at a set level by controlling the opening and closing of a valve body on the valve stem while driving an electric motor based on the pressure of the reduced-pressure fluid detected by a sensor. This allows for flexible response to fluctuations in the required flow rate while automatically maintaining various set discharge pressures.

[0014] Furthermore, in this regulator, the electric motor is an AC servo motor or a DC brushless motor, and the valve shaft moving structure is a feed screw formed by a combination of a trapezoidal male screw formed on the outer surface of a cylindrical motion shaft that is coaxially attached to the valve shaft and is movable in the axial direction but not rotatable, and a trapezoidal female screw formed on the inner surface of a cylindrical member fitted onto the motion shaft and meshing with the trapezoidal male screw, and by rotating the trapezoidal female screw by the drive of the electric motor, the valve shaft can be moved in the axial direction without rotating the trapezoidal male screw, and the valve shaft can be moved to the open or closed position in a short time and stopped accurately without making the regulator excessively large.

[0015] In addition, if the cylindrical member with the trapezoidal female thread is integrated with the rotor of the electric motor, the regulator and the electric motor are configured coaxially and integrally, which allows the size of the regulator equipped with the electric motor to be kept compact.

[0016] Furthermore, in a regulator equipped with the aforementioned feed screw, if either or both of the trapezoidal male and female threads constituting the feed screw are made of self-lubricating resin, smooth valve opening and closing operation can be maintained for a long period of time at low cost without requiring lubrication at the meshing portion of the screws. [Effects of the Invention]

[0017] According to the present invention, the discharge pressure is maintained at a set pressure by controlling the opening and closing of a pressure regulating valve while driving an electric motor based on the detected discharge pressure. This makes it possible to automatically maintain various specified discharge pressures while responding to fluctuations in the required flow rate. [Brief explanation of the drawing]

[0018] [Figure 1] A longitudinal cross-sectional view showing the closed valve state of an electronically controlled regulator, which is the first embodiment of the present invention. [Figure 2]FIG. 1 is a longitudinal sectional view showing the valve open state of the electronically controlled regulator. [Figure 3] FIG. 2 is a sectional view taken along line A-A. [Figure 4] FIG. 1 is a functional block diagram of an engine fuel supply system provided with the electronically controlled regulator. [Figure 5] FIG. 2 is a longitudinal sectional view showing the valve open state of an electronically controlled regulator that is the second embodiment of the present invention. [Figure 6] FIG. 5 is a longitudinal sectional view showing the valve closed state of the electronically controlled regulator. [Mode for Carrying Out the Invention]

[0019] Hereinafter, modes for carrying out the present invention will be described with reference to the drawings. In the present invention, the self-lubricating resin refers to a resin material such as polyacetal, monomer cast nylon, fluororesin, and ultra-high molecular weight polyethylene, which has high surface self-lubricating property compared with other general resin materials, so that no lubricating oil or lubricant is required or the amount thereof is minimized in the sliding portion and friction portion between the members.

[0020] FIG. 1 shows the valve closed state of an electronically controlled regulator 1A which is the first embodiment of the present invention, and FIG. 2 shows the valve open state. This electronically controlled regulator 1A is assumed to be used mainly as a pressure reducing unit that delivers gas fuel, which is a high-pressure fluid, while reducing the pressure thereof to a predetermined pressure in a supply system for gas fuel or the like.

[0021] The configuration will be roughly described as follows: inside a cylindrical body 10A made of metal, the configuration consists of a high pressure portion 2A from an inlet 11 for introducing high-pressure fluid to a pressure regulating valve 20, a discharge portion 3A from the pressure regulating valve 20 to an outlet 12 for discharging the pressure-reduced fluid, and a pressure control portion 4A for operating the pressure regulating valve 20 to reduce and adjust the pressure of the discharged pressure-reduced fluid to a set pressure.

[0022] The pressure regulating valve 20 comprises a valve stem 21 on which an umbrella-shaped valve body 22 is coaxially mounted and which is capable of reciprocating in the axial direction; a donut-shaped valve seat 23 having a seat surface 24 that can make close contact with the valve body 22 and having a valve hole 25 in the center; and a discharge pressure adjusting means that adjusts the discharge pressure by changing the distance between the valve body 22 and the valve seat 23 by reciprocating the valve stem 21.

[0023] This discharge pressure adjustment means consists of an electric motor 30, a driver 40 that drives and controls the electric motor 30, and a motion shaft 50A that is coaxially connected to the valve shaft 21 by inserting the tip end of the valve shaft 21 into a connecting hole 51 formed at its end. The valve body 22 of the valve shaft 21, which is located below the discharge pressure adjustment means, is moved axially by the drive of the electronically controlled electric motor 30 between a closed valve position (Figure 1) where the valve body 22 and the seat surface 24 are in close contact and an open valve position (Figure 2) where they are separated, thereby changing the opening area and automatically adjusting the pressure of the discharged decompressed fluid to be equal to the set pressure. This is the most distinctive feature of the present invention.

[0024] The discharge pressure adjustment means includes a valve shaft movement structure, which will be described later, that is driven by the electric motor 30 to move the valve shaft 21 in the axial direction. Based on the value of a pressure sensor (not shown) that detects the pressure of the decompressed fluid in a pressure sensor installation section 14 connected to the discharge port 12 downstream of the valve hole 25 by a communication hole 13, the electric motor 30 operates the valve shaft movement structure to open and close the pressure regulating valve 20 so as to maintain the pressure of the decompressed fluid being discharged at a set pressure.

[0025] Furthermore, the pressure sensor is not limited to being installed within the pressure sensor installation section 14; it can be installed at any location along the path through which the depressurized fluid is delivered, as long as it is arranged in series or parallel with the discharge port 12 and capable of detecting the discharge pressure.

[0026] Thus, according to the electronically controlled regulator 1A of this embodiment, instead of adjusting the discharge pressure with a pressure regulating spring as in conventional regulators, the electric motor 30 is driven and controlled based on the discharge pressure detected by the pressure sensor to reciprocate the valve shaft 21 in the axial direction, thereby opening and closing the pressure regulating valve 20 (changing the opening area) and adjusting the discharge pressure. This solves the problem in conventional regulators where the pressure drop is large when the required flow rate is high and small when the required flow rate is low, mechanically limiting the discharge pressure range and the required flow rate range. Furthermore, it makes it possible to handle various required discharge pressures and flow rates with a single product without requiring the replacement of parts.

[0027] In this embodiment, the electric motor 30, which constitutes part of the discharge pressure adjustment means, is an AC servo motor with excellent controllability, and the rotation angle can be quickly and accurately positioned by the drive control of the driver 40. However, a DC brushless motor may be used instead of this AC servo motor.

[0028] Furthermore, in the electronically controlled regulator 1A of this embodiment, the valve stem movement structure is a feed screw 60 consisting of a trapezoidal male screw 61 formed on the outer circumferential surface of a cylindrical motion shaft 50A provided on the tip side of the valve stem 21, and a trapezoidal female screw 62 formed on the inner circumferential surface of a cylindrical member rotor 31 which constitutes part of the electric motor 30, and which meshes with the trapezoidal male screw 61. The configuration is such that the trapezoidal female screw 62, which is integrated with the inner circumferential surface side of the rotor 31, rotates around the trapezoidal male screw 61 when driven by the electric motor 30.

[0029] Preferably, the feed screw 60 has either one or both of its trapezoidal male thread 61 and trapezoidal female thread 62 molded from a self-lubricating resin material. This eliminates the need to apply lubricating oil to the meshing portion of the trapezoidal male thread 61 and the trapezoidal female thread 62, making it easier to maintain smooth valve opening and closing operation over a long period of time at low cost.

[0030] Furthermore, the motion shaft 50A has an insertion hole 52 formed on its inner circumferential surface at the end opposite to the connecting hole 51, and a rotation-preventing shaft 70, which has its base end 72 fixed to the body 10A and a flat portion 74 formed on the outer circumferential surface of its tip 73, is slidably inserted into the insertion hole 52 in the axial direction (see Figure 3). The structure is such that the rotational movement of the motion shaft 50A is restricted by the close contact of their respective flat portions and converted into linear movement in the axial direction, thereby moving the valve shaft 21 connected by the connecting hole 51.

[0031] Furthermore, by making the seat diameter of the valve seat 23 formed by the seat surface 24 and the effective diameter of the valve body 22 approximately the same, it becomes easier to achieve miniaturization of the electric motor 30 used and miniaturization of the electronically controlled regulator 1A.

[0032] The configuration of the pressure control unit 4A in the electronically controlled regulator 1A will be described in more detail.

[0033] The electric motor 30 housed in the storage chamber 5 formed on the upper side of the body 10A uses an AC servo motor with excellent controllability, as described above. Multiple stators 31, each supported by a winding 32, are arranged on the inner circumference of the storage chamber 5, and a substantially cylindrical rotor 33, with multiple magnets 34 arranged on its outer circumference opposite each stator 31, is rotatably arranged with its central axis being the same as the valve shaft 21.

[0034] The rotor 33 is supported by sliding bearings 35 and 36 located at both its upper and lower ends, and rotates due to the magnetic force generated by energizing the winding 32 facing the magnet 34, thereby driving the electric motor 30. Furthermore, by using a self-lubricating resin with excellent surface lubrication performance for the material of the sliding bearings 35 and 36, the smooth rotation of the rotor 33 can be ensured over a long period of time without requiring periodic lubrication of the friction parts.

[0035] A cover 38 for aligning the rotor 33 and mounting the magnetic pole position sensor 37 is provided above the stator 31, and a magnet 39 is provided above the rotor 33. The rotational position of the rotor 33 can be detected by the magnetic pole position sensor 37 in conjunction with the magnetic poles generated by the current flowing through the stator 31.

[0036] Furthermore, the driver 40 for motor drive is positioned above the magnetic pole position sensor 37. The driver 40 is connected to the winding 32 by terminal 41, and an external terminal 42 for external input is exposed to the outside of the body 10A.

[0037] Next, the operation of this embodiment will be explained with reference to the cross-sectional views in Figures 1 to 3 and the functional block diagram in Figure 4.

[0038] As shown in Figure 1, in the initial state, the valve stem 21 is pushed up by a spring 26 located at its base end, and the valve body 22 is in close contact with the seat surface 24 of the valve seat 23, thus closing the valve. Reference numeral 27 denotes a spring for pressing down and holding the valve seat 23.

[0039] When the electronically controlled regulator 1A is in use, as shown in Figure 4, a target pressure (Pref) command is input to the driver 40 via the external terminal 42 from the engine control unit 100, which is an electronic control means. At this time, if the relationship between the target pressure (Pref) and the discharge pressure value (Pout) detected by the pressure sensor 101 is Pref > Pout, then current is applied to the winding 32 of the stator 31, and the rotor 33 rotates in a direction that pushes down the motion shaft 50A, causing the valve body 22 of the valve shaft 21 to be pushed down as well, resulting in the open valve state shown in Figure 2.

[0040] Conversely, when the relationship between the target pressure (Pref) and the discharge pressure value (Pout) satisfies Pref<Pout, by rotating the rotor 33 in the direction of pushing up the motion shaft 50A, the valve element 22 of the valve shaft 21 is also pushed up accordingly, resulting in the valve closed state as shown in Figure 1.

[0041] By executing the control as described above to open and close the pressure regulating valve 20 (changing the opening area), the discharge pressure can be maintained at the specified target pressure. In addition, the discharge pressure can be freely changed by inputting a target set pressure corresponding to the usage conditions of the regulator.

[0042] Incidentally, as shown in Figure 4, the pressure sensor 103 that detects the pressure of the fluid after passing through the oil filter 102 may be used in place of the pressure sensor 101, or may be used in combination therewith.

[0043] Figure 5 shows the valve closed state of the electronically controlled regulator 1B according to the second embodiment of the present invention, and Figure 6 shows the valve open state. Similar to the electronically controlled regulator 1A, this electronically controlled regulator 1B is assumed to be used mainly in a supply system for gaseous fuel or the like as a pressure reducing means for delivering gaseous fuel, which is a high-pressure fluid, while reducing the pressure to a predetermined pressure.

[0044] To describe its configuration roughly, the inside of the cylindrical body 10B made of metal is composed of the high-pressure section 2B from the inlet 11 for introducing high-pressure fluid to the pressure regulating valve 80, the discharge section 3B from the pressure regulating valve 80 to the discharge port 12 for discharging the decompressed fluid, and the pressure control section 4B for operating the pressure regulating valve 80 to reduce and adjust the pressure of the discharged decompressed fluid to the set pressure, which is also the same as the electronically controlled regulator 1A.

[0045] The pressure regulating valve 80 comprises a cylindrical valve stem 81 having a passage 83 through which a fluid can pass, and an annular valve body 82 coaxially mounted and capable of reciprocating in the axial direction; an annular valve seat 84 having a seat surface 85 into which the valve body 82 can make close contact; and a discharge pressure adjusting means for adjusting the fluid discharge pressure by reciprocating the valve stem 81 to change the distance between the valve body 82 and the valve seat 84.

[0046] This discharge pressure adjustment means consists of an electric motor 30, a driver 40 that drives and controls the electric motor 30, and a motion shaft 50B that is integrally formed with the valve shaft 81. The valve body 82 of the valve shaft 81, which is positioned to pass through the discharge pressure adjustment means, is moved axially by the drive of the electronically controlled electric motor 30 between a closed valve position (Figure 5) where the valve body 82 and the seat surface 84 are in close contact and an open valve position (Figure 6) where they are separated, thereby changing the opening area and automatically adjusting the pressure of the discharged reduced pressure so that it becomes equal to the set pressure. This is also the same as the electronically controlled regulator 1A.

[0047] The discharge pressure adjustment means includes a valve shaft movement structure, which will be described later, that is driven by the electric motor 30 to move the valve shaft 81 in the axial direction. Based on the value of a pressure sensor (not shown) that detects the discharge pressure in the path through which the depressurized fluid is delivered downstream of the valve shaft 81 (after passing through the passage 83), the electric motor 30 operates the valve shaft movement structure to open and close the pressure regulating valve 80 so as to maintain the pressure of the discharged depressurized fluid at a set pressure.

[0048] The valve stem movement structure in the electronically controlled regulator 1B of this embodiment is a feed screw 60 consisting of a trapezoidal male screw 61 formed on the outer surface of a cylindrical motion shaft 50B integrally formed on the outer circumference of the valve stem 81, and a trapezoidal female screw 62 formed on the inner surface of the rotor 33, which is a cylindrical member constituting part of the electric motor 30, and which meshes with the trapezoidal male screw 61. The configuration is such that the trapezoidal female screw 62, which is integral with the inner surface of the rotor 33, rotates around the trapezoidal male screw 61 when driven by the electric motor 30.

[0049] Furthermore, the valve stem 81, which is integrated with the motion shaft 50B, has a rotation-preventing projection 91 that protrudes circumferentially outward at the end opposite to the valve body 82, and a rotation-preventing guide 92 that protrudes toward the body 10A so as to sandwich the rotation-preventing projection 91. The rotation-preventing projection 91 and the rotation-preventing guide 92 come into contact, restricting the rotational movement of the motion shaft 50B and converting it into linear movement in the axial direction, thereby moving the valve stem 81, which is integrated with the motion shaft 50B.

[0050] Furthermore, by making the seat diameter of the valve seat 84 formed by the seat surface 85 and the effective diameter of the valve body 82 approximately the same, it becomes easier to achieve miniaturization of the electric motor 30 used and miniaturization of the electronically controlled regulator 1B.

[0051] Thus, according to the electronically controlled regulator 1B of this embodiment, instead of adjusting the discharge pressure by utilizing the balance between the load applied to the pipe-shaped valve stem and the load of the pressure regulating spring arranged on the opposite side via the valve stem, as in conventional regulators, the electronically controlled regulator 1A described above employs a method of adjusting the discharge pressure by driving and controlling the electric motor 30 based on the discharge pressure detected by the pressure sensor to reciprocate the valve stem 81 in the axial direction, thereby opening and closing the pressure regulating valve 80 (changing the opening area). This solves the problem in conventional regulators where the pressure drop is large when the required flow rate is high and small when the required flow rate is low, mechanically limiting the discharge pressure range and the required flow rate range, while enabling a single product to handle various required discharge pressures and flow rates without the need to replace parts.

[0052] Although the electronically controlled regulator 1A and the electronically controlled regulator 1B have a relationship where the structure of their respective valve bodies and valve stems are inversely related, the excellent effects of the present invention can be obtained in both embodiments.

[0053] As described above, the present invention enables the regulator to automatically maintain various specified discharge pressures while being able to respond to fluctuations in the required flow rate. [Explanation of Symbols]

[0054] 1A,1B Electronically controlled regulator, 2A,2B High-pressure section, 3A,3B Discharge section, 4A,4B Pressure control section, 5 Storage chamber, 10A,10B Body, 11 Inlet, 12 Discharge port, 13 Communication hole, 14 Pressure sensor mounting section, 20 Pressure regulating valve, 21 Valve stem, 22 Valve body, 23 Valve seat, 24 Seat surface, 25 Valve hole, 26,27 Spring, 30 Electric motor, 31 Stator, 32 Winding, 33 Rotor, 34 Magnet, 35 Sliding bearing, 36 Sliding bearing, 37 Magnetic pole position sensor, 38 Cover, 39 Magnet, 40 Driver, 41 Terminal, 42 External terminal, 50A,50B Motion shaft, 51 Connecting hole, 52 Insertion hole, 60 Lead screw, 61 Trapezoidal male screw, 62 Trapezoidal female thread, 71 Anti-rotation shaft, 72 Base end, 73 Tip, 74 Flat section, 80 Pressure regulating valve, 81 Valve stem, 82 Valve body, 83 Passage, 84 Valve seat, 85 Seat surface, 91 Anti-rotation projection, 92 Anti-rotation guide, 100 Engine control unit, 101, 103 Pressure sensor, 102 Oil filter

Claims

1. A regulator comprising a pressure regulating valve having a valve body coaxially mounted inside a body forming an inlet and a discharge port, a valve stem capable of reciprocating in the axial direction, a valve seat having a seat surface into which the valve body can make close contact, and a discharge pressure regulating means that adjusts the discharge pressure of the fluid by changing the distance between the valve body and the valve seat by reciprocating the valve stem, wherein a high-pressure fluid introduced from the inlet is reduced in pressure and adjusted by the pressure regulating valve and discharged from the discharge port as a reduced-pressure fluid of a set pressure, The discharge pressure adjustment means includes an electric motor and a valve shaft moving structure which is operated by the electric motor to move the valve shaft in the axial direction, thereby changing the distance between the valve body and the valve seat. Based on the value of a pressure sensor which is arranged in series or parallel with the discharge port and detects the pressure of the decompressed fluid, the electric motor operates the valve shaft moving structure to open and close the pressure regulating valve so that the pressure of the decompressed fluid maintains the set pressure. The valve stem moving structure is A motion shaft that is coaxially connected to the valve shaft and moves in a linear manner, A cylindrical member fitted onto the aforementioned motion shaft and rotating by the drive of the electric motor, A rotation-preventing part that restricts the rotational motion of the aforementioned motion shaft and converts it into linear motion in the axial direction. It is a rotary-to-linear motion conversion mechanism equipped with, The aforementioned axis of motion is, A connecting hole formed at one end, through which the valve stem is connected, It has an insertion hole formed at the other end, with a flat portion formed on a part of its inner circumferential surface, The aforementioned anti-rotation part is, A flat portion is formed on a part of the outer surface, and it has a rotation-preventing shaft that is slidably inserted into the insertion hole in the axial direction, The flat portion of the insertion hole and the flat portion of the anti-rotation shaft come into close contact with each other, restricting the rotational movement of the motion shaft and converting it into linear motion in the axial direction. An electronically controlled regulator characterized by the following features.

2. Either one or both of the trapezoidal male screw and the trapezoidal female screw are made of self-lubricating resin. The electronically controlled regulator according to claim 1, characterized by its features.

3. The aforementioned anti-rotation shaft is made of a separate component from the body. The base end is fixed to the body, and the tip end is inserted into the motion shaft. The electronically controlled regulator according to claim 1, characterized by its features.

4. The valve stem moving structure is a feed screw comprising a trapezoidal male screw and a trapezoidal female screw that meshes with the trapezoidal male screw, The trapezoidal male screw is formed on the outer circumferential surface of the motion shaft, The trapezoidal female thread is formed on the inner circumferential surface of the cylindrical member. An electronically controlled regulator according to any one of claims 1 to 3.

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