Pressure reducing valve device, and power supply control device for the pressure reducing valve device

Abstract

To provide a pressure reducing valve that suppresses the wear of a valve seat part at turning off of electric conduction of a solenoid coil.SOLUTION: A valve body energization member 26 energizes a valve body energization end part 226 in a valve-closing direction of a valve body 20. A piston energization member 36 energizes a piston energization end part 326 in a valve-opening direction of the valve body 20. A rod energization member 46 energizes a push rod 41 fixed to a mover 45. An energization resultant force, which is a resultant force of an energization force of the valve body energization member 26, an energization force of the piston energization member 36 and an energization force of the rod energization member 46, acts in a direction of opening the valve body 20. A force that energizes a piston 32 in the valve-closing direction of the valve body 20 as a result of an action of the pressure of the gas fuel of an outlet pressure chamber 13 on a large diameter part 322 of the piston 32 is defined as a gas action force. Depending on a drive current passed to a solenoid coil 42, an amount of valve lift from a valve seat part 15 of the valve body 20 can be set to an "amount of intermediate lift" which is greater than 0 and smaller than a full-lift amount corresponding to an amount at full opening.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a pressure reducing valve device and a power supply control device for a pressure reducing valve device. [Background technology]

[0002] Conventionally, in systems that supply gaseous fuel to fuel consumers, devices for reducing the pressure of the gaseous fuel to a target pressure are known. For example, in the gas pressure regulating valve disclosed in Patent Document 1, when an electric current is passed through the solenoid coil, the valve body is pushed by a pressing member and opens, allowing the gaseous fuel to flow from the primary port (inlet side) to the secondary port (discharge side). The area of ​​the part of the valve body that sits on the valve seat is set to be equal to the cross-sectional area of ​​the sliding part of the valve body, which is described as improving pressure controllability. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2012 / 017667 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The electronic pressure regulating valve described in Patent Document 1 is a normally closed valve, and the solenoid coil is energized by PWM control. The valve body is fully open (full lift) when the solenoid coil is energized ON, and fully closed by spring force when the energization is OFF. It is not possible to control the valve body to a half-lift state, which is between fully open and fully closed. Because the valve body collides with the valve seat each time the energization is turned OFF, there is a risk of wear on the valve seat. Wear is particularly noticeable if the valve seat is made of resin.

[0005] The present invention has been made in view of the above-mentioned problems, and its objective is to provide a pressure reducing valve device that suppresses wear of the valve seat when the solenoid coil is turned off. Another objective is to provide an energization control device for a pressure reducing valve device in which wear of the valve seat is suppressed, which can control the discharge pressure by controlling the drive current of the solenoid coil. [Means for solving the problem]

[0006] The pressure reducing valve device according to the present invention is installed in the middle of a fuel supply passage (83, 84) in a gaseous fuel supply system (900) that supplies gaseous fuel from a supply source device (81) to a supply destination device (88), and reduces the pressure of the gaseous fuel. This pressure reducing valve device comprises a valve body (20), a valve body biasing member (26), a pressure reducing valve housing (191-193), a piston (32), a piston biasing member (36), and solenoid parts (40, 50).

[0007] The valve body has a valve portion (21) that is seated on or separated from the valve seat portion (15), and a sliding portion (22) that is on the opposite side of the valve seat portion from the valve portion and slides axially integrally with the valve portion while its outer circumference is airtightly sealed. The valve body biasing member is provided in the back pressure chamber (27) which houses the valve body biasing end portion (226), which is the end of the valve body opposite to the valve portion, and biases the valve body biasing end portion in the valve body closing direction.

[0008] The pressure reducing valve housing has an inlet pressure chamber (12), an inlet passage (11), an outlet pressure chamber (13), and a discharge passage (18). The inlet pressure chamber is the space around the valve and sliding parts. The inlet passage is through which the gaseous fuel flowing into the inlet pressure chamber passes. The outlet pressure chamber is formed on the opposite side of the valve from the valve seat and communicates with the inlet pressure chamber via an inter-chamber connection hole (14) when the valve body is open. The discharge passage is through which the gaseous fuel discharged to the supply device passes.

[0009] The piston has a contact end (323) that abuts against the valve portion of the valve body, and a large-diameter portion (322) that receives the pressure of the gaseous fuel in the outlet pressure chamber, and is axially slidable while its outer circumference is airtightly sealed. The piston biasing member biases the piston biasing end (326), which is the end of the piston opposite to the valve body contact end, in the valve body opening direction.

[0010] The solenoid section includes a movable element (45, 55), a push rod (41, 51), a rod biasing member (46, 56), and a solenoid coil (42, 52). The movable element is housed in a solenoid chamber (47, 57). The outer circumference of one end of the push rod is fixed to the movable element, and the other end abuts against the piston biasing end or valve body biasing end. The rod biasing member biases the push rod or the movable element from one end to the other. The solenoid coil moves the movable element by magnetic attraction forces (Fm1, Fm2) generated by the application of a drive current.

[0011] The back pressure chamber and the outlet pressure chamber are in communication via a valve body communication passage (23) formed in the valve body and a piston communication passage (33) formed in the piston.

[0012] The resultant biasing force (Fs1, Fs2), which is the resultant force of the valve body biasing member (Fv), the piston biasing member (Fp), and the rod biasing member (Fr1, Fr2), acts in the direction of opening the valve body.

[0013] The gaseous force (Fg) is defined as the force exerted by the pressure of the gaseous fuel in the outlet pressure chamber, acting on the larger diameter portion of the piston and biasing the piston in the direction of closing the valve body. This pressure reducing valve device can adjust the valve lift amount from the valve seat of the valve body by adjusting the resultant force of three forces: the resultant force of the biasing member, the gas force, and the magnetic attractive force of the solenoid coil. Depending on the drive current supplied to the solenoid coil By changing the magnetic attraction force, The valve lift amount can be set to an "intermediate lift amount" that is greater than 0 but less than the full lift amount corresponding to the fully open position.

[0014] The pressure reducing valve device of the present invention has a normally open configuration, and since the valve body does not seat on the valve seat when the solenoid coil is turned off, wear on the valve seat can be suppressed. Furthermore, the discharge pressure can be controlled by controlling the drive current supplied to the solenoid coil and changing the intermediate lift amount according to the requirements of the supply device.

[0015] In the first embodiment of the pressure reducing valve device, the solenoid section (40) is located on the side opposite the valve body relative to the outlet pressure chamber. The push rod (41) abuts against the piston biasing end. The magnetic attractive force (Fm1) of the solenoid coil (42) acts in the direction of opening the valve body via the movable element and the push rod.

[0016] In the second form of pressure reducing valve device, the solenoid section (50) is located on the side opposite the valve body to the back pressure chamber, and the solenoid chamber (57) and the back pressure chamber are in communication via a connecting passage (29). The push rod (51) abuts against the biasing end of the valve body. The magnetic attractive force (Fm2) of the solenoid coil (52) acts in the direction of closing the valve body via the movable element and the push rod.

[0017] The current control device for a pressure reducing valve according to the present invention controls the drive current supplied to the solenoid coil of the pressure reducing valve. This current control device controls the drive current so that the valve lift amount from the valve seat when the valve body is open is a target value that is "greater than or equal to 0 and less than or equal to the full lift amount corresponding to when the valve is fully open," which is determined according to the required flow rate and target pressure of the supplying device.

[0018] Furthermore, when applied to a gaseous fuel supply system further equipped with a pressure sensor (85) for detecting the discharge pressure of the gaseous fuel discharged by the pressure reducing valve device, the energization control device of the pressure reducing valve device may control the drive current to reduce the difference between the pressure detected by the pressure sensor and the target pressure.

[0019] For example, the supply device is an injector for gaseous fuel that injects gaseous fuel into the intake pipe (89) communicating with the engine (90) or into the cylinder. The target value of the valve lift amount of the pressure reducing valve device is determined based on the required injection amount corresponding to the required flow rate of the injector and the discharge pressure of the gaseous fuel discharged by the pressure reducing valve device.

Brief Description of the Drawings

[0020] [Figure 1] Configuration diagram of a gaseous fuel supply system to which the pressure reducing valve device of each embodiment is applied. [Figure 2] Schematic diagram of an injector for gaseous fuel. [Figure 3] Enlarged schematic diagram of the tip showing the (a) fully closed, (b) intermediate lift, and (c) full lift states of the injector for gaseous fuel. [Figure 4] (a) Diagram showing the relationship between the injector injection amount and discharge pressure and the intermediate lift region - full lift region, (b) diagram showing the change in the needle lift amount. [Figure 5] Diagram showing the relationship between the injector injection amount and discharge pressure and the valve lift amount required for the pressure reducing valve device. [Figure 6] (a) Diagram comparing the change in the valve lift amount and discharge pressure of the pressure reducing valve device according to this embodiment with a comparative example (intermediate lift control not possible), (b) enlarged diagram of parts L and P. [Figure 7] Cross-sectional view of the pressure reducing valve device according to the first embodiment. [Figure 8] Enlarged schematic diagram of the valve part of FIG. 7 at the time of valve opening. [Figure 9] Enlarged schematic diagram of the valve part of FIG. 7 at the time of valve closing. [Figure 10] Cross-sectional views of (a) line Xa - Xa and (b) line Xb - Xb of FIG. 9. [Figure 11] Diagram showing the relationship of the forces acting on the valve body in the first embodiment. [Figure 12] Diagram showing the relationship between the drive current and the valve opening / closing operation in the first embodiment. [Figure 13] Cross-sectional view of the pressure reducing valve device according to the second embodiment. [Figure 14]A diagram showing the relationship of forces acting on the valve body in the second embodiment. [Figure 15] A diagram showing the relationship between the drive current and the valve opening / closing operation in the second embodiment. [Figure 16] A schematic block diagram illustrating the feedback control of discharge pressure. [Figure 17] A time chart showing the change in discharge pressure when the target pressure is reduced. [Figure 18] A flowchart illustrating the control flow for valve lift amount. [Figure 19] Cross-sectional view of a pressure reducing valve device according to the third embodiment. [Figure 20] Cross-sectional view of a pressure reducing valve device according to the fourth embodiment. [Modes for carrying out the invention]

[0021] Embodiments of a pressure reducing valve device and an energizing control device for the pressure reducing valve device will be described with reference to the drawings. The pressure reducing valve device according to this embodiment is installed in the middle of a fuel supply passage in a gaseous fuel supply system that supplies gaseous fuel from a supply source device to a supply destination device via a fuel supply passage, and reduces the pressure of the gaseous fuel. Furthermore, the energizing control device for the pressure reducing valve device according to this embodiment controls the drive current supplied to the solenoid coil of the pressure reducing valve device.

[0022] This embodiment includes the first to fourth embodiments of the mechanical configuration of the pressure reducing valve device. In these multiple embodiments, substantially identical components are denoted by the same reference numerals, and their descriptions are omitted. The first and second embodiments represent two main configurations, while the third and fourth embodiments add secondary configurations to the first and second embodiments. Regarding the energization control device, a common control configuration for the first and second embodiments will be described.

[0023] [Gaseous fuel supply system] Referring to Figure 1, an example configuration of the gaseous fuel supply system 900 will be described. This type of gaseous fuel supply system is disclosed in Japanese Patent Publication No. 2022-178431, etc., and is installed in vehicles that use hydrogen or compressed natural gas as fuel, for example. The gaseous fuel supply system 900 is a system that supplies gaseous fuel stored in a fuel tank 81, which is the "supply source device," to a gaseous fuel injector 88, which is the "supply destination device," via fuel supply passages 83 and 84. Hereafter, the gaseous fuel injector 88 will be abbreviated as "injector 88." Also, in Figures 4, 5, etc., the injector will be abbreviated as "INJ."

[0024] The pressure reducing valve device 100 is installed in the middle of the fuel supply passages 83 and 84 and reduces the pressure of the gaseous fuel, for example, hydrogen, from about 70 MPa to about 1 to 10 MPa. Of the fuel supply passages, the passage from the fuel tank 81 to the pressure reducing valve device 100 is designated as the upstream supply passage 83, and the passage from the pressure reducing valve device 100 to the injector 88 is designated as the downstream supply passage 84. The fuel tank 81 stores gaseous fuel supplied from the outside through a supply pipe (not shown) that has a backflow prevention function. The upstream supply passage 83 is provided with a main shut-off valve 82 that switches between supplying or shutting off gaseous fuel from the fuel tank 81. The main shut-off valve 82 has functions such as backflow prevention, overflow prevention, and pressurization prevention safety.

[0025] The pressure reducing valve device 100 opens and closes the valve body in accordance with commands from the ECU 70, thereby reducing the gaseous fuel flowing in from the upstream supply passage 83 to the target pressure and discharging it. As will be described in detail later, a key feature of the pressure reducing valve device 100 in this embodiment is that it is "intermediate lift controllable" according to the injection amount and target pressure of the injector 88, which is the supply destination device. In other words, in this embodiment, the valve lift amount can be set to an "intermediate lift amount" that is greater than 0 and smaller than the full lift amount corresponding to when fully open.

[0026] The downstream supply passage 84 is equipped with a pressure sensor 85 that detects the pressure of the gaseous fuel discharged by the pressure reducing valve device 100 and supplied to the injector 88. The ECU 70 performs feedback control so that the pressure detected by the pressure sensor 85 follows the target pressure. In addition to the discharge pressure of the gaseous fuel, the ECU 70 sets the target pressure based on information about the temperature of the gaseous fuel and the vehicle's movement, and operates the pressure reducing valve device 100 according to the target pressure. Specifically, the ECU 70 functions as an "energy control device" that controls the energization of the solenoid coil of the pressure reducing valve device 100.

[0027] The injector 88 injects gaseous fuel into, for example, the intake manifold 89, which is connected to the engine 90, in accordance with instructions from the ECU 70. The injected gaseous fuel is mixed with air introduced from the atmosphere and introduced into the cylinder through the intake port of the engine 90. Note that the gaseous fuel is not limited to being injected into the intake manifold 89, but may also be injected directly into the cylinder.

[0028] Figure 2 shows a schematic configuration of the injector 88. The upper part of Figure 2 will be referred to as "upper" and the lower part as "lower" in this explanation. A nozzle 882 is formed at the lower end of the cylindrical housing 881. A needle chamber 883 is formed along the central axis of the housing 881, and a valve seat portion 884 that tapers toward the nozzle 882 is formed at the bottom of the needle chamber 883. The needle 885 is housed within the needle chamber 883 so as to be able to move up and down, and when it moves downward, its tip comes into contact with the valve seat portion 884, closing the nozzle 882. Figure 3(a) shows an enlarged view of the fully closed state.

[0029] The upper outer circumference of the needle 885 is fixed to the movable core 886. The needle 885 is constantly biased in the valve closing direction by a valve closing spring 887 which is provided in contact with the upper end surface. When the solenoid coil 888 is energized by a command from the ECU 70, the needle 885 is moved together with the movable core 886 by magnetic attraction. 5 The valve rises, and the nozzle 882 opens. In this way, the needle 885 is directly driven by the energization of the solenoid coil 888.

[0030] At this time, the needle lift amount changes due to the balance between the biasing force of the valve closing spring 887, the magnetic attraction force, and the force due to the fuel pressure. In the intermediate lift state shown in Figure 3(b), the needle lift amount Ln is greater than 0 and less than the full lift amount FLn. In the full lift state shown in Figure 3(c), the needle lift amount Ln is equal to the full lift amount FLn.

[0031] In Figure 4(a), the solid line shows the relationship between the drive pulse width and injection volume of the injector 88 when the discharge pressure is high, and the dashed line shows the relationship when the discharge pressure is low. In the full-lift (FL) region, where the injection volume is greater than the inflection point CP, the injection volume changes linearly with respect to the change in drive pulse width. On the other hand, in the intermediate-lift (HL) region, where the injection volume is smaller than the inflection point CP, the injection volume changes curvilinearly with respect to the change in drive pulse width.

[0032] Figure 4(b) shows the change in needle lift amount Ln when the solenoid coil 888 is energized. The integrated value of the needle lift amount Ln, i.e., the area below the curve, corresponds to the injection amount. In the full lift (FL) region, after energization begins, the needle lift amount Ln reaches the full lift amount FLn and the full lift state continues for a predetermined period. On the other hand, in the intermediate lift (HL) region, after energization begins, the needle lift amount Ln increases from 0 and the valve opens, but it returns to the closed state without reaching the full lift amount FLn. Since the injection amount accuracy is poor in the intermediate lift region, it is required to operate the injector 88 in the full lift region where injection amount accuracy can be easily ensured.

[0033] In Figure 4(a), the injection amount within the injector's operating range is from the minimum value Qmin to the maximum value Qmax. When applied to an internal combustion engine, for example, the dynamic range depending on the operating conditions is larger than when used in a fuel cell. When the discharge pressure is low, the inflection point CP(B) is on the smaller injection amount side compared to the inflection point CP(A) when the discharge pressure is high, and the entire injection amount within the operating range can be covered in the full lift range. Therefore, by controlling the discharge pressure of the pressure reducing valve device 100 according to the operating state (required injection amount) of the engine 90, specifically by controlling the discharge pressure of the pressure reducing valve device 100 to a low pressure when operating with a small injection amount, the operation of the injector 88 in the intermediate lift range can be avoided, and a wide range of operating conditions can be accommodated.

[0034] In other words, as shown in Figure 5, the valve lift amount Lv of the pressure reducing valve device 100 is determined according to the injector injection amount and discharge pressure (target pressure) of the supply destination. The larger the injector injection amount and the higher the discharge pressure, the closer the valve lift amount Lv of the pressure reducing valve device 100 is set to the full lift amount FLv. Conversely, the smaller the injector injection amount and the lower the discharge pressure, the closer the valve lift amount Lv of the pressure reducing valve device 100 is set to 0.

[0035] Next, referring to Figure 6, the significance of the intermediate lift control capability of the pressure reducing valve device 100 in this embodiment will be explained in comparison with a comparative example in which intermediate lift control is not possible, such as the pressure regulating valve in Patent Document 1 (International Publication No. 2012 / 017667). In Figure 6(a), the solid line shows the change in valve lift amount Lv and discharge pressure of this embodiment, and the dashed line shows the change in valve lift amount Lv and discharge pressure of the comparative example. Figure 6(b) shows an enlarged view of the vertical axis scales of sections L and P in Figure 6(a). We assume conditions where the injector injection amount is small, the target pressure is low, and the average valve lift amount is close to fully closed.

[0036] In the comparative example, the pressure reducing valve device fully opens the valve body when the solenoid coil is energized, and fully closes the valve body when the energization to the solenoid coil is stopped. When the valve body is fully open, the discharge pressure rises to the target pressure and decreases with each injector injection. Because the valve body collides with the valve seat each time the power is turned off, there is a risk of wear on the valve seat.

[0037] In contrast, the pressure reducing valve device 100 of this embodiment remains open at an intermediate lift amount close to the average valve lift amount. More precisely, the valve lift amount Lv increases slightly as the discharge pressure instantaneously decreases from the target pressure with each injector injection, but it recovers by the next injector injection. Therefore, in this embodiment, the valve seat is protected from wear, the discharge pressure is stabilized, and the discharge pressure accuracy is improved. Furthermore, compared to a pressure reducing valve device without a solenoid that cannot control the discharge pressure, the pressure reducing valve device 100 of this embodiment, which can control the discharge pressure, is clearly superior.

[0038] Thus, this embodiment provides a pressure reducing valve device 100 that suppresses wear of the valve seat due to the de-energization of the solenoid coil. Next, the detailed configuration of the pressure reducing valve device 100 will be described for each embodiment. The reference numerals for the pressure reducing valve device, pressure reducing valve housing, etc. in the first and second embodiments are two-digit numbers such as "10" and "19", respectively, followed by the third digit which represents the embodiment.

[0039] (First Embodiment) The pressure reducing valve device 101 of the first embodiment will be described with reference to Figures 7 to 12. In the following description of the embodiment, for convenience, the upper side of the cross-sectional view will be referred to as "upper" and the lower side of the cross-sectional view as "lower". Figure 7 shows an overall cross-section of the pressure reducing valve device 101, and Figures 8 and 9 show enlarged views of the area around the valve portion 21. The contact end 323 of the piston 32 is in constant contact with the end face of the valve portion 21.

[0040] As shown in Figures 8 and 9, the valve body 20 moves vertically in the figures according to the balance between the combined force Fs1 of the biasing member, the gas force (force due to the pressure of the gaseous fuel) Fg, and the magnetic attractive force Fm1 (see Figure 11). Each of these forces will be described in detail later. When the valve is open, as shown in Figure 8, the valve body 20 is pushed down by the piston 32 and moves downward, separating the valve portion 21 from the valve seat portion 15. When the valve is closed, as shown in Figure 9, the valve body 20 rises due to the gas force Fg and the valve portion 21 seats on the valve seat portion 15.

[0041] Figure 7 shows the non-operating state, i.e., when no gaseous fuel is supplied from the fuel tank 81 to the pressure reducing valve device 101 and the solenoid coil 42 is not energized. In this state, the gaseous force Fg and the magnetic attractive force Fm1 are 0, and the valve body 20 opens due to the combined biasing force Fs1, which is the resultant biasing force of the three biasing members 26, 36, and 46. In other words, the pressure reducing valve device 101 has a normally open configuration.

[0042] The pressure reducing valve device 101 has a pressure reducing valve housing 191 through which gaseous fuel passes, and a valve mechanism 201 and a solenoid 40 are constructed. The pressure reducing valve housing 191 has an inlet passage 11, an inlet pressure chamber 12, an outlet pressure chamber 13, an inter-chamber connection hole 14, a valve seat 15, a discharge passage 18, etc. The inlet passage 11 and the discharge passage 18 include a portion directly formed in the pressure reducing valve housing 191 and an internal passage of a coupler attached to the pressure reducing valve housing 191.

[0043] The inlet passage 11 is the passage through which gaseous fuel flows from the upstream supply passage 83 into the inlet pressure chamber 12. The inlet pressure chamber 12 is the space around the valve portion 21 and the sliding portion 22. The outlet pressure chamber 13 is formed between the valve seat portion 15 and the piston guide member 31, on the side opposite the valve portion 21. The outlet pressure chamber 13 communicates with the inlet pressure chamber 12 via the inter-chamber connection hole 14 when the valve body 21 is open.

[0044] The inter-chamber connection hole 14 connects the inlet pressure chamber 12 and the outlet pressure chamber 13 along the axial direction of the valve body 20. A valve seat portion 15 is formed at the corner of the inter-chamber connection hole 14 on the inlet pressure chamber 12 side. The discharge passage 18 is a passage through which gaseous fuel discharged to the injector 88 via the downstream supply passage 84 passes.

[0045] The valve body 20 has a rod-shaped sliding portion 22 and a valve portion 21 provided at the upper end of the sliding portion 22. The valve portion 21 closes the valve by seating on the valve seat portion 15, or opens the valve by moving away from the valve seat portion 15. The sliding portion 22 slides axially integrally with the valve portion 21 on the side opposite to the valve seat portion 15, with its outer circumference airtightly sealed. A valve body communication passage 23 is formed in the sliding portion 22 of the valve body 20. The valve body communication passage 23 includes a longitudinal passage 237 extending in the axial direction and a transverse passage 238 that intersects the longitudinal passage 237 and communicates with the back pressure chamber 27.

[0046] The valve mechanism 201 includes a valve body sliding guide member 24, a sliding seal 25, a valve body biasing member 26, and a back pressure chamber forming member 281. The valve body sliding guide member 24 forms a sliding hole through which the sliding portion 22 slides. The sliding seal 25 is mounted on the valve body sliding guide member 24 and airtightly seals the outer circumference of the sliding portion 22.

[0047] The back pressure chamber forming member 281 forms a back pressure chamber 27 on its inside. The valve biasing end 226, which is the end of the valve body 20 opposite to the valve portion 21, is housed in the back pressure chamber 27. The valve biasing member 26, which is made of a coil spring or the like, is provided in the back pressure chamber 27 and biases the valve biasing end 226 in the closing direction of the valve body 20. In Figure 11, the biasing force of the valve biasing member 26 is represented as Fv.

[0048] The back pressure chamber 27 and the inlet pressure chamber 12 are airtightly sealed at the outer circumference of the sliding portion 22 by the sliding seal 25. The back pressure chamber 27 and the outlet pressure chamber 13 are in communication via the valve body communication passage 23 formed in the valve body 20 and the piston communication passage 33 formed in the piston 32. As shown in Figure 10, the area A1 on the inner circumference side of the seat diameter of the valve portion 21 and valve seat portion 15 projected in the axial direction of the valve body 20 is set to be equal to the cross-sectional area A2 of the sliding portion 22. This makes it possible to cancel the axial force acting on the valve body 20 due to the gaseous fuel flowing into the inlet pressure chamber 12.

[0049] As shown in Figures 8 and 9, the piston 32 is formed in a stepped cylindrical shape including a small diameter portion 321 and a large diameter portion 322. The small diameter portion 321 is inserted through the inter-chamber connection hole 14. The tip of the small diameter portion 321 forms a contact end portion 323 that abuts against the valve portion 21 of the valve body 20. The end face of the large diameter portion 322 connected to the small diameter portion 321 forms a stepped portion 324. The gaseous force Fg is defined as the force that acts on the large diameter portion 322 of the piston 32 due to the pressure of the gaseous fuel in the outlet pressure chamber 13, biasing the piston 32 in the direction of closing the valve body 20. In other words, the gaseous force Fg is the product of the differential pressure obtained by subtracting atmospheric pressure from the pressure in the outlet pressure chamber 13 and the pressure-receiving area of ​​the large diameter portion 322.

[0050] A piston communication passage 33 is formed in the small-diameter portion 321. The piston communication passage 33 includes a longitudinal passage 337 that penetrates axially and a transverse passage 338 that intersects with the longitudinal passage 337 and communicates with the outlet pressure chamber 13. When the contact end 323 of the piston 32 is in contact with the valve portion 21, the longitudinal passage 337 of the piston communication passage 33 and the longitudinal passage 237 of the valve body 20 are aligned in a straight line.

[0051] The piston guide member 31 forms an outlet pressure chamber 13 between itself and the pressure reducing valve housing 191, guiding the sliding of the large-diameter portion 322. The sliding seal 35 is mounted on the piston guide member 31 and airtightly seals the outer circumference of the large-diameter portion 322. In this way, the piston 32 has a contact end 323 and a large-diameter portion 322, and is axially slidable while its outer circumference is airtightly sealed.

[0052] The piston housing 34 is provided on the solenoid coil 42 side of the piston guide member 31 and forms a piston biasing chamber 37 inside. The piston biasing end 326, which is the end of the piston 32 opposite to the contact end 323, is housed in the piston biasing chamber 37. A piston biasing member 36, composed of a coil spring or the like, is provided in the piston biasing chamber 37 and biases the piston biasing end 326 in the opening direction of the valve body 20. In Figure 11, the biasing force of the piston biasing member 36 is represented as Fp.

[0053] In the first embodiment, the solenoid section 40 is located on the opposite side of the valve body 20 from the outlet pressure chamber 13. The solenoid section 40 includes a solenoid coil 42, a movable element case 44, a movable element 45, a rod biasing member 46, a push rod 41, etc. The solenoid coil 42 moves the movable element 45 relative to the piston housing 34 by a magnetic attractive force Fm1 (see Figure 11) generated by the application of a drive current. In the first embodiment, the piston housing 34 functions as a movable element suction section, and the magnetic attractive force Fm1 acts in the valve opening direction of the valve body 20.

[0054] The piston housing 34, the movable element case 44, the movable element 45, and the outer components of the solenoid coil 42 are made of a soft magnetic material such as iron, and form a magnetic circuit when the solenoid coil 42 is energized. A non-magnetic section 43 is provided between the piston housing 34 and the movable element case 44 to block the magnetic circuit. The movable element case 44 has a solenoid chamber 47 on its inside, and the movable element 45 is housed in the solenoid chamber 47.

[0055] The push rod 41 has its outer circumference at one end fixed to the movable element 45, and its other end abuts against the piston biasing end 326. The rod biasing member 46, which is made of a coil spring or the like, is provided in the solenoid chamber 47 and biases the push rod 41 from one end to the other (i.e., from the top to the bottom of the figure). Alternatively, the rod biasing member 46 may bias the movable element 45 to which the push rod 41 is fixed. In Figure 11, the biasing force of the rod biasing member 46 is represented as Fr1.

[0056] Referring to Figures 11 and 12, the relationship of forces acting on the valve body 20 in the pressure reducing valve device 101 of the first embodiment will be explained. In the pressure reducing valve device 101 of the first embodiment, the biasing force Fv of the valve body biasing member 26, the biasing force Fp of the piston biasing member 36, and the rod biasing member 4 The resultant force of the six biasing forces Fr1 is defined as the resultant force Fs1 of the biasing members. The direction of each biasing force Fv, Fp, and Fr1 is indicated by the arrows in Figure 11. The values ​​of each biasing force Fv, Fp, and Fr1 are positive values ​​and are set so that "Fp + Fr1 > Fv". The resultant force Fs1 of the biasing members in the valve opening direction is expressed by the following formula. Fs1 = (Fp + Fr1) - Fv > 0

[0057] In the non-operating state of the pressure reducing valve device 101, since the gas acting force Fg and the magnetic attracting force Fm1 are 0, the valve body 20 is opened to full lift (FL) by the urging member resultant force Fs1 in the valve opening direction. When the gaseous fuel supplied from the fuel tank 81 flows into the outlet pressure chamber 13 from the inlet pressure chamber 12 during valve opening, the gas acting force Fg acting on the large diameter portion 322 pushes up the piston 32, and the valve body 20 is urged in the valve closing direction. In the range where the gas acting force Fg is smaller than the urging member resultant force Fs1, as the gas acting force Fg increases, the valve lift amount at the intermediate lift (HL) gradually decreases. When the gas acting force Fg exceeds the urging member resultant force Fs1, the valve body 20 closes.

[0058] When the solenoid coil 42 is energized, the magnetic attracting force Fm1 of the solenoid coil 42 acts in the direction of opening the valve body via the mover 45, the push rod 41, and the piston 32. The valve body 20 stops at a position where the force (Fs1 + Fm1) in the valve opening direction and the force (Fg) in the valve closing direction are balanced. The larger the magnetic attracting force Fm1, the larger the gas acting force Fg that becomes the opening / closing threshold value. By adjusting the magnetic attracting force Fm1 with the drive current supplied to the solenoid coil 42, the valve lift amount Lv of the valve body 20 from the valve seat portion 15 can be set to a target value between 0 and the full lift amount FLv, and the discharge pressure can be controlled. Therefore, the discharge pressure can be controlled to a constant pressure regardless of the supply pressure that changes according to the remaining amount of the fuel tank 81. Also, it is possible to control the discharge pressure according to the operating state of the engine.

[0059] As shown in FIG. 12, the magnetic attracting force Fm1 increases substantially proportionally to the drive current. On the premise that the gas acting force Fg is larger than the urging member resultant force Fs1, the valve body 20 fully opens when the drive current is equal to or greater than the full open critical value Io1, and fully closes when the drive current is equal to or less than the full close critical value Ic1 (<Io1). Between the full close critical value Ic1 and the full open critical value Io1 of the drive current, the valve lift amount Lv changes gradually according to the drive current.

[0060] The ECU 70 determines a target value for the valve lift amount Lv of the pressure reducing valve device 101 according to the injector injection amount and discharge pressure (target pressure) of the supply destination (see Figure 5). Then, based on the target value of valve lift amount Lv, the ECU 70 sets the drive current command value I * The ECU calculates the value and energizes the solenoid coil 42. Also, when temporarily closing the valve body 20 in the undershoot control described later, the ECU 70 calculates the drive current command value I * Set the value to a value less than or equal to the totally closed critical value Ic1.

[0061] (Second Embodiment) Referring to Figures 13 to 15, the differences between the pressure reducing valve device 102 of the second embodiment and the pressure reducing valve device 101 of the first embodiment will be explained. The pressure reducing valve device 102 of the second embodiment differs from the pressure reducing valve device 101 of the first embodiment in the position where the solenoid section 50 is provided and the member that the push rod 51 contacts. Figures 13, 14, and 15 correspond to Figures 7, 11, and 12 of the first embodiment, respectively. The rod biasing force Fr2, the resultant biasing member force Fs2, and the magnetic attraction force Fm2, which are affected by the differences in configuration from the first embodiment, are indicated by the number "2" at the end of their symbols.

[0062] Regarding the peripheral configuration of the piston 32, the formation of a piston biasing chamber 37 inside the piston housing 38 and the fact that the piston biasing member 36 housed in the piston biasing chamber 37 biases the piston biasing end 326 in the valve body 20 in the opening direction are the same as in the first embodiment. However, a solenoid is not provided on the side of the piston housing 38 opposite to the piston guide member 31, and a push rod 41 is not provided in the piston biasing chamber 37. Furthermore, the biasing force Fp can be adjusted by turning the adjustment screw 39 provided on the piston housing 38 to adjust the set height of the piston biasing member 36.

[0063] In the valve mechanism 202 of the second embodiment, the back pressure chamber forming member 282 forms a back pressure chamber 27 on its inside. The solenoid section 50 of the second embodiment is provided on the opposite side of the valve body 20 from the back pressure chamber 27. The solenoid section 50 includes a solenoid coil 52, a movable element case 54, a movable element 55, a rod biasing member 56, a push rod 51, etc. The solenoid coil 52 moves the movable element 55 relative to the back pressure chamber forming member 282 by a magnetic attractive force Fm2 (see Figure 14) generated by the application of a drive current. In the second embodiment, the back pressure chamber forming member 282 functions as a movable element suction section, and the magnetic attractive force Fm2 acts in the valve closing direction of the valve body 20.

[0064] The back pressure chamber forming member 282, the movable element case 54, the movable element 55, and the outer members of the solenoid coil 52 are made of a soft magnetic material such as iron, and form a magnetic circuit when the solenoid coil 52 is energized. A non-magnetic section 53 is provided between the back pressure chamber forming member 282 and the movable element case 54 to block the magnetic circuit. The movable element case 54 has a solenoid chamber 57 on its inside, and the movable element 55 is housed in the solenoid chamber 57. The solenoid chamber 57 and the back pressure chamber 27 are in communication via a communication passage 29.

[0065] The push rod 51 has its outer circumference at one end fixed to the movable element 55, and its other end abuts against the valve body biasing end 226. The rod biasing member 56, which is made of a coil spring or the like, is provided in the solenoid chamber 57 and biases the movable element 55 from one end of the push rod 51 to the other end (i.e., from the bottom to the top of the figure). Alternatively, the rod biasing member 56 may bias the push rod 51 which is fixed to the movable element 55. In Figure 14, the biasing force of the rod biasing member 56 is represented as Fr2.

[0066] Referring to Figures 14 and 15, the relationship of forces acting on the valve body 20 in the second embodiment of the pressure reducing valve device 102 will be explained. In the second embodiment of the pressure reducing valve device 102, the resultant force of the biasing force Fv of the valve body biasing member 26, the biasing force Fp of the piston biasing member 36, and the biasing force Fr2 of the rod biasing member 56 is defined as the resultant force Fs2 of the biasing members. The direction of each biasing force Fv, Fp, and Fr2 is indicated by the arrows in Figure 14. The values ​​of each biasing force Fv, Fp, and Fr2 are positive values ​​and are set so that "Fp > Fv + Fr2". The resultant force Fs1 of the biasing members in the valve opening direction is expressed by the following formula. Fs² = Fp - (Fv + Fr²) > 0

[0067] In the non-operating state of the pressure reducing valve device 102, the gas force Fg and magnetic attractive force Fm2 are 0, so the valve body 20 opens to full lift (FL) due to the combined force Fs2 of the biasing member in the opening direction. When gaseous fuel supplied from the fuel tank 81 is introduced from the inlet pressure chamber 12 to the outlet pressure chamber 13 when the valve is opened, the gas force Fg acting on the large diameter portion 322 pushes up the piston 32, and the valve body 20 is biased in the closing direction. In the range where the gas force Fg is smaller than the combined force Fs2 of the biasing member, the valve lift amount at intermediate lift (HL) gradually decreases as the gas force Fg increases. When the gas force Fg exceeds the combined force Fs2 of the biasing member, the valve body 20 closes.

[0068] When the solenoid coil 52 is energized, the magnetic attractive force Fm2 of the solenoid coil 52 acts in the direction of closing the valve body via the movable element 55 and the push rod 51. The valve body 20 stops at a position where the force in the opening direction (Fs2) and the force in the closing direction (Fg + Fm2) are balanced. As the magnetic attractive force Fm2 increases, the gas acting force Fg, which is the threshold for opening and closing, decreases. By adjusting the magnetic attractive force Fm2 with the drive current supplied to the solenoid coil 52, the valve lift amount Lv from the valve seat portion 15 of the valve body 20 can be set to a target value between 0 and the full lift amount FLv, thereby enabling control of the discharge pressure. Therefore, the discharge pressure can be controlled to a constant pressure regardless of the supply pressure which changes depending on the remaining amount in the fuel tank 81. Furthermore, it is also possible to control the discharge pressure according to the operating state of the engine.

[0069] As shown in Figure 15, the magnetic attractive force Fm2 increases approximately proportionally to the drive current. Assuming that the gas force Fg is smaller than the resultant force Fs2 of the biasing members, the valve body 20 fully opens when the drive current is less than or equal to the fully open critical value Io2, and fully closes when the drive current is greater than or equal to the fully closed critical value Ic2 (>Io2). Between the fully open critical value Io2 and the fully closed critical value Ic2, the valve lift amount Lv changes gradually according to the drive current.

[0070] The ECU 70 determines a target value for the valve lift amount Lv of the pressure reducing valve device 102 according to the injector injection amount and discharge pressure (target pressure) of the supply destination (see Figure 5). Then, based on the target value of valve lift amount Lv, the ECU 70 sets the drive current command value I * The ECU calculates the value and energizes the solenoid coil 52. Also, when temporarily closing the valve body 20 in the undershoot control described later, the ECU 70 sets the drive current command value I * Set the value to a value greater than or equal to the totally closed critical value Ic2.

[0071] [Power supply control device] Next, referring to Figures 16 to 18, the control configuration of the ECU (Energy Control Unit) 70, which controls the drive current supplied to the solenoid coil of the pressure reducing valve device, will be described. In this description, the reference numeral "100" is used to represent the pressure reducing valve device, encompassing the pressure reducing valve devices 101-104 of each embodiment.

[0072] As described above with reference to Figure 1, the ECU 70 of this embodiment is applied to a gaseous fuel supply system 900 equipped with a pressure sensor 85 that detects the discharge pressure of the gaseous fuel discharged by the pressure reducing valve device 100. As shown in Figure 16, the ECU 70 controls the drive current to reduce the difference between the pressure detected by the pressure sensor 85 and the target pressure through discharge pressure feedback control.

[0073] Specifically, the ECU70 controls the drive current command value I according to the difference between the detected pressure and the target pressure. *The system calculates the values ​​and energizes the solenoid coils 42 and 52 of the pressure reducing valve device 100. The valve lift amount Lv of the valve body 20 is determined according to the magnetic attractive forces Fm1 and Fm2 and the gaseous force Fg (omitted in Figure 16) generated in the solenoid coils 42 and 52. The discharge pressure of the gaseous fuel discharged by the pressure reducing valve device 100 is detected by the pressure sensor 85, and the detected pressure is fed back to the ECU 70.

[0074] As described above with reference to Figures 2 to 6, the target value of the valve lift amount Lv of the pressure reducing valve device 100 is determined based on the required injection amount of the injector 88, which is the supplying device, and the discharge pressure of the gaseous fuel discharged by the pressure reducing valve device 100. The target value of the valve lift amount Lv is 0 or greater, and less than or equal to the full lift amount corresponding to when fully open. The ECU 70 controls the drive current so that the valve lift amount Lv becomes the target value.

[0075] Refer to the time chart in Figure 17. For example, consider a situation in which, during transient operation of an engine equipped with a gaseous fuel supply system 900, the required injection amount of the injector 88, which is the supplying device, decreases rapidly, and the target pressure is changed to drop sharply from a relatively high value to a low value. Specifically, when the absolute value of the rate of pressure reduction in which the target pressure decreases per unit time is greater than or equal to the rate of pressure reduction threshold, it is determined that "the target pressure has been changed to drop sharply." In this situation, the normal control of the comparative example and the proposed technology, "undershoot control," are compared. In the normal control of the comparative example, the valve lift amount Lv is controlled to approach linearly the target value of the valve lift amount Lv corresponding to the changed target pressure.

[0076] When the required injection amount of injector 88 decreases sharply, the needle lift amount Ln (see Figures 3 and 4) decreases. The gaseous fuel discharged from the pressure reducing valve device 100 into the downstream supply passage 84 has no means of consumption other than injection from injector 88. When the injection amount of injector 88 decreases sharply, depending on the target value of the normal control, the gaseous fuel supplied from the pressure reducing valve device 100 will exceed the consumption. In that case, the discharge pressure in the downstream supply passage 84 temporarily rises as indicated by the [*] mark, and then gradually approaches the changed target pressure. Therefore, after the target pressure is changed at time t1, the discharge pressure reaches the changed target pressure at time t3.

[0077] In contrast, undershoot control is a proposed technique to suppress a temporary increase in discharge pressure. In undershoot control, at time t1 when the target pressure is changed, the valve lift amount Lv is temporarily set to 0, i.e., fully closed. Since the discharge of gaseous fuel from the pressure reducing valve device 100 to the downstream supply passage 84 is stopped, a temporary increase in discharge pressure is suppressed. Compared to normal control, the discharge pressure approaches the target pressure after the change more quickly because there is no temporary increase.

[0078] At time t2, the pressure detected by the pressure sensor 85 falls within the target attainment range, which is set to include a predetermined allowable deviation from the target pressure after the change. Subsequently, the ECU 70 controls the drive current to increase the valve lift amount Lv to the target value. This control, which causes the valve lift amount Lv to be excessively reduced to 0 relative to the target value before returning to the target value, is called "undershoot control".

[0079] When the ECU 70 determines that the target pressure has been changed to drop sharply, it implements undershoot control to suppress a temporary increase in discharge pressure, thereby shortening the time it takes for the discharge pressure to reach the target pressure after the change compared to normal control. On the other hand, if the decrease in target pressure is relatively gradual and the gaseous fuel supplied from the pressure reducing valve device 100 is less than or equal to the consumption amount, a temporary increase in discharge pressure does not occur, and therefore undershoot control does not need to be implemented. Rather, from the viewpoint of avoiding wear of the valve seat portion 15 due to completely closing the valve body 20, it is preferable to implement normal control when a temporary increase in discharge pressure does not occur.

[0080] Furthermore, in undershoot control, instead of completely closing the valve body 20, the valve lift amount Lv may be temporarily reduced to a value closer to the fully closed side than the target value of the valve lift amount Lv. Although the effect is reduced compared to the case where the valve body 20 is completely closed, the temporary increase in discharge pressure can be suppressed as much as possible by reducing the amount of gaseous fuel supplied from the pressure reducing valve device 100. In addition, since the valve body 20 is not completely closed, it is effective in avoiding wear of the valve seat portion 15.

[0081] Figure 18 shows the control flow of the valve lift amount Lv by the ECU 70. In the flowchart, the symbol "S" represents a step. In S1, the ECU 70 calculates the target pressure, in S2 it obtains the detected pressure from the pressure sensor 85, and in S3 it controls the drive current of the pressure reducing valve device 100 so that the detected pressure approaches the target pressure.

[0082] In S4, it is determined whether the required injection amount of the injector 88 decreases and whether the absolute value of the rate of pressure reduction of the target pressure is greater than or equal to the rate of pressure reduction threshold. If the answer in S4 is YES, in S5 the ECU 70 controls the drive current to set the valve lift amount Lv to 0, that is, to completely close the valve body 20. At this time, in the first embodiment, "I" in Figure 12 * In the second embodiment, "Ic2 ≤ Ic1" is shown in Figure 15. * The drive current command value I * The calculation is performed.

[0083] Subsequently, in S6, it is determined whether the detected pressure has entered the target reach determination range. S6 is repeated until it is determined as YES, and when it is determined as YES, the process proceeds to S7. When YES in S6 or NO in S2, in S7, the ECU 70 controls the drive current so that the valve lift amount Lv becomes the target value. At this time, in the first embodiment, "Ic1 < I * <Io1" in FIG. 12, and in the second embodiment, "Io2 < I * <Ic2" in FIG. 15, and the drive current command value I * is calculated.

[0084] As described above, in this embodiment, the ECU 70 performs feedback control of the discharge pressure with respect to the pressure reducing valve device 100 having a configuration capable of intermediate lift control. Even if the target pressure is constant, when the injection amount from the injector 88 changes, the pressure loss in each part of the fuel supply passage changes according to the flow rate. Therefore, in order to control the discharge pressure to the target pressure, a delicate adjustment of the valve lift amount Lv is required. By performing feedback control on the detected pressure of the pressure sensor 85, it is possible to improve the control accuracy of the discharge pressure regardless of the injector injection amount.

[0085] In addition, in order to lower the pressure of the injector 88 which is the supply destination device, it is necessary to inject fuel from the injector 88. However, when the target pressure of the discharge pressure drops below the current pressure during the transient operation of the engine, a temporary increase in the discharge pressure occurs and the pressure followability deteriorates. In particular, in a pressure reducing valve device that controls the discharge pressure by the pressure received by a piston or a valve and the biasing force of an elastic member without using an actuator such as a solenoid, the valve lift amount of the valve body gradually decreases and follows the target pressure.

[0086] In contrast, in this embodiment, when the ECU 70 determines that the target pressure has been changed to rapidly decrease, it once fully closes the valve body 20, or controls the drive current so as to once decrease the valve lift amount Lv to a value on the fully closed side rather than the target value of the valve lift amount Lv. By adjusting the valve lift amount Lv using the solenoid coils 42 and 52, it is possible to improve the followability to the target pressure particularly during transient operating conditions where the target pressure rapidly decreases.

[0087] (Third embodiment) Referring to Figure 19, a third embodiment of the pressure reducing valve device 103, which has two secondary configurations added to the pressure reducing valve device 101 of the first embodiment, will be described. Firstly, the pressure reducing valve device 103 is provided with an adjustment screw 49 on the ceiling of the movable element case 48, which is an adjustment mechanism that allows adjustment of the biasing force Fr1 of the rod biasing member 46 by adjusting the set height of the rod biasing member 46 from outside the pressure reducing valve device 103. By adjusting the biasing force Fr1 of the rod biasing member 46 with the adjustment screw 49, the combined biasing force Fs1 can be adjusted, and the upper and lower limits of the discharge pressure control range can be easily adjusted.

[0088] Secondly, the pressure reducing valve device 103 has a solenoid coil 42 Solenoid coil in at least a portion of its axial range 42 A channel 17 is formed on the radially outer side of the valve, communicating with the outlet pressure chamber 13 and the discharge passage 18. In the example shown in Figure 19, the channel 17 is formed to enclose the outer circumference in an annular shape, extending across the lower part of the piston guide member 31, the piston housing 34, and the solenoid coil 42. Multiple communication grooves 16 are formed in the circumferential direction on the seating surface where the piston guide member 31 and the pressure reducing valve housing 193 abut, connecting the outlet pressure chamber 13 and the channel 17 in the radial direction. The discharge passage 18 is positioned to connect to the upper part of the channel 17.

[0089] The gaseous fuel flowing out from the outlet pressure chamber 13 is discharged through the channel 17 and out of the discharge passage 18. This allows the discharged gaseous fuel to cool the heat generated by energizing the solenoid coil 42, thereby suppressing the heat generation of the solenoid coil 42 and preventing burnout due to overheating.

[0090] (Fourth Embodiment) The pressure reducing valve device 104 of the fourth embodiment shown in Figure 20, compared to the pressure reducing valve device 102 of the second embodiment, has an adjustment screw 59 as an "adjustment mechanism" provided on the ceiling of the movable member case 58, similar to the first secondary configuration of the third embodiment. By turning the adjustment screw 59, the set height of the rod biasing member 56 can be adjusted from outside the pressure reducing valve device 104, thereby adjusting the biasing force Fr2 of the rod biasing member 56. In the fourth embodiment, the combined biasing force Fs2 can be adjusted using both the adjustment screw 39 that can adjust the biasing force Fp of the piston biasing member 36 and the adjustment screw 59 that can adjust the biasing force Fr2 of the rod biasing member 56, making it easy to adjust the upper and lower limits of the discharge pressure control range. Alternatively, the adjustment screw 39 may be omitted in the fourth embodiment.

[0091] (Other embodiments) (a) In a gaseous fuel supply system, the "supply source device" is not limited to a fuel tank 81 that stores gaseous fuel supplied from an external source, but may also be a device that generates and delivers gaseous fuel itself. The "recipient device" is not limited to a gaseous fuel injector 88, but may be any consumer that consumes gaseous fuel. The "required injection amount of the injector," which is a parameter that determines the target value of the valve lift amount Lv of the pressure reducing valve device 100, can generally be rephrased as the "required flow rate of the recipient device."

[0092] (b) The valve body biasing member 26, piston biasing member 36, and rod biasing members 46, 56 are not limited to coil springs, but may be any member that applies a biasing force generated by elasticity to the target element they come into contact with. The mechanical configuration for holding each biasing member 26, 36, 46, 56 is not limited to the configuration shown in each embodiment, but may be any configuration that realizes the desired function. Also, the positions of the dividing surfaces of the valve body 20, piston 32, and push rods 41, 51 are not limited to the positions exemplified in the above embodiments, but may be configured to realize the desired function.

[0093] The present invention is not limited in any way to the embodiments described above, and can be implemented in various forms without departing from its spirit. [Explanation of Symbols]

[0094] 100 (101-104) ... Pressure reducing valve device, 11: Inflow passage, 12: Inflow pressure chamber, 13: Outlet pressure chamber, 14: Inter-chamber connection hole, 15: Valve seat, 18: Discharge passage, 191-193: Pressure reducing valve housing, 20: Valve body, 21: Valve section, 22: Sliding section, 226: Valve body biasing end, 23: Valve body connecting passage, 26: Valve body biasing member, 27: Back pressure chamber, 32: Piston, 322: Large diameter section, 323: Contact end, 326: Piston biasing end, 33: Piston connecting passage, 36: Piston biasing member, 40, 50: Solenoid section, 41, 51: Push rod, 42, 52: Solenoid coil, 45, 55: Movable element, 46, 56: Rod biasing member, 47, 57: Solenoid chamber, 70: ECU (Electrical Control Unit), 81: Fuel Tank (Fuel Supply Device), 83: Upstream supply passage (fuel supply passage), 84: Downstream supply passage (fuel supply passage), 88: Injector for gaseous fuel (supply destination device), 900: Gaseous fuel supply system.

Claims

1. In a gaseous fuel supply system (900) that supplies gaseous fuel from a source device (81) to a destination device (88) via fuel supply passages (83, 84), a pressure reducing valve device is provided in the middle of the fuel supply passage to reduce the pressure of the gaseous fuel, A valve body (20) having a valve portion (21) that is seated on or separated from the valve seat portion (15), and a sliding portion (22) on the opposite side of the valve portion from the valve seat portion, which slides axially integrally with the valve portion while its outer circumference is airtightly sealed, A valve biasing member (26) is provided in the back pressure chamber (27) that houses the valve biasing end (226), which is the end of the valve body opposite to the valve portion, and biases the valve biasing end in the valve closing direction. A pressure reducing valve housing (191-193) is formed having an inlet pressure chamber (12) which is the space around the valve and the sliding part, an inlet passage (11) through which gaseous fuel flowing into the inlet pressure chamber passes, an outlet pressure chamber (13) formed on the opposite side of the valve seat from the valve and communicating with the inlet pressure chamber via an inter-chamber connection hole (14) when the valve body is open, and a discharge passage (18) through which gaseous fuel discharged to the supply destination device passes, A piston (32) has a contact end (323) that abuts against the valve portion of the valve body, and a large-diameter portion (322) that receives the pressure of the gaseous fuel in the outlet pressure chamber, and its outer circumference is airtightly sealed while it is slidable in the axial direction, A piston biasing member (36) biases the piston biasing end (326), which is the end of the piston opposite to the contact end, in the valve opening direction, A solenoid section (40, 50) includes a movable element (45, 55) housed in a solenoid chamber (47, 57), a push rod (41, 51) whose outer circumference at one end is fixed to the movable element and whose other end abuts against the piston biasing end or the valve body biasing end, a rod biasing member (46, 56) that biases the push rod or the movable element from one end of the push rod to the other end, and a solenoid coil (42, 52) that moves the movable element by magnetic attractive force (Fm1, Fm2) generated by the application of a drive current, Equipped with, The back pressure chamber and the outlet pressure chamber are in communication via a valve body communication passage (23) formed in the valve body and a piston communication passage (33) formed in the piston. The combined biasing force (Fs1, Fs2), which is the resultant force of the biasing members (Fv) of the valve body biasing member, the biasing force (Fp) of the piston biasing member, and the biasing forces (Fr1, Fr2) of the rod biasing member, acts in the direction of opening the valve body. If we define the gaseous force (Fg) as the force exerted by the pressure of the gaseous fuel in the outlet pressure chamber acting on the large-diameter portion of the piston, thereby biasing the piston in the valve body towards closing, then, The amount of valve lift from the valve seat of the valve body can be adjusted by adjusting the resultant force of the three forces: the resultant force of the biasing member, the gas force, and the magnetic attractive force of the solenoid coil. A pressure reducing valve device that changes the magnetic attraction force in accordance with the drive current supplied to the solenoid coil, and can set the valve lift amount to an intermediate lift amount that is greater than zero and smaller than the full lift amount corresponding to the fully open position.

2. The solenoid section (40) is provided on the opposite side of the valve body from the outlet pressure chamber, The pressure reducing valve device according to claim 1, wherein the push rod (41) abuts against the piston biasing end, and the magnetic attractive force (Fm1) of the solenoid coil (42) acts in a direction to open the valve body via the movable element, the push rod, and the piston.

3. The solenoid section (50) is provided on the side opposite to the valve body with respect to the back pressure chamber, and the solenoid chamber (57) and the back pressure chamber are in communication via a communication passage (29). The pressure reducing valve device according to claim 1, wherein the push rod (51) abuts against the biasing end of the valve body, and the magnetic attractive force (Fm2) of the solenoid coil (52) acts in a direction to close the valve body via the movable element and the push rod.

4. The pressure reducing valve device according to any one of claims 1 to 3, which is provided with an adjustment mechanism (49, 59) that allows the biasing force of the rod biasing member to be adjusted by adjusting the set height of the rod biasing member from outside the pressure reducing valve device.

5. The pressure reducing valve housing (193) is located radially outward of the solenoid coil in at least a portion of the axial range of the solenoid coil, and has a channel (17) that communicates with the outlet pressure chamber and the discharge passage. The pressure reducing valve device according to any one of claims 1 to 3, wherein the gaseous fuel flowing out from the outlet pressure chamber is discharged through the channel and out of the discharge passage.

6. A power supply control device for controlling the drive current supplied to the solenoid coil of a pressure reducing valve device according to any one of claims 1 to 3, An energizing control device for a pressure reducing valve device, which controls the drive current so that the valve lift amount (Lv) of the valve body from the valve seat portion becomes a target value that is 0 or greater and less than or equal to the full lift amount corresponding to when fully open, determined based on the required flow rate and target pressure of the supply destination device.

7. This is applied to a gaseous fuel supply system equipped with a pressure sensor (85) that detects the discharge pressure of the gaseous fuel discharged by the pressure reducing valve device, The power supply control device for a pressure reducing valve device according to claim 6, which controls the drive current to reduce the difference between the pressure detected by the pressure sensor and the target pressure.

8. When the required flow rate of the supplying device decreases and the absolute value of the rate at which the target pressure decreases per unit time is greater than or equal to the rate of pressure reduction threshold, the valve lift amount of the pressure reducing valve device is temporarily reduced to a value closer to the fully closed side than the target value of the valve lift amount. The power supply control device for a pressure reducing valve device according to claim 7, wherein the drive current is controlled to increase the valve lift amount to a target value after the pressure detected by the pressure sensor enters a target attainment determination range set to include a predetermined allowable deviation with respect to the target pressure.

9. The aforementioned supply device is a gaseous fuel injector that injects gaseous fuel into the intake manifold (89) or cylinder that communicates with the engine (90). The energization control device for a pressure reducing valve according to claim 6, wherein the target value of the valve lift amount of the pressure reducing valve device is determined based on the required injection amount corresponding to the required flow rate of the injector and the discharge pressure of the gaseous fuel discharged by the pressure reducing valve device.

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