Gas solenoid valve

Abstract

Provided is a gas solenoid valve including: a housing including a valve passage having a first flow passage part and a second flow passage part; a main valve body housed in the housing so as to open and close the valve passage and including a pilot passage connected to the first flow passage part and the second flow passage part, and a pilot seat; a biasing member for biasing the main valve body in the direction of opening the valve passage; a pilot valve body that can be separated from and seated on the pilot seat and that opens and closes the pilot passage by being separated therefrom and seated thereon; a solenoid for moving the pilot valve body in an opening direction; a coil spring for biasing the pilot valve body in a closing direction; and a spring receiving member interposed between the coil spring and the pilot valve body. The spring receiving member abuts on the pilot valve body so as to be relatively rotatable around a main axis extending in the opening direction.

Description

Gas solenoid valve

[0001] The present disclosure relates to a gas electromagnetic valve that opens and closes a valve passage through which gas flows.

[0002] A known example of a gas solenoid valve is the valve device disclosed in Patent Document 1. In the valve device disclosed in Patent Document 1, a pilot passage is formed in a main valve body, and the pilot piston opens and closes the pilot passage by seating and unseating the pilot piston on a pilot seat. More specifically, when a solenoid is energized, the pilot piston unseats the pilot seat, thereby opening the pilot passage. On the other hand, when the solenoid is de-energized, the pilot piston seats on the pilot seat due to the biasing force of the coil spring, thereby closing the pilot passage.

[0003] Japanese Patent Application Laid-Open No. 2021-173354

[0004] In the valve device of Patent Document 1, a coil spring biases the pilot piston to seat it on the pilot seat, and further presses it to close the pilot passage. The coil spring is constructed by spirally winding a wire rod, and when extended, it applies not only a biasing force but also a torsional load to the pilot piston. Therefore, a load obtained by adding the biasing force of the coil spring and the torsional load acts on the pilot seat via the pilot piston. The greater the pressure of the fluid flowing through the valve device, the greater the load acting on the pilot seat, which reduces the durability of the pilot seat.

[0005] Therefore, an object of the present disclosure is to provide a gas solenoid valve that can improve the durability of the pilot seat.

[0006] The solenoid valve for gas of the first disclosure comprises: a housing including a valve passage having a first flow path portion and a second flow path portion; a main valve element accommodated in the housing to open and close the valve passage, the main valve element including a pilot passage connected to the first flow path portion and the second flow path portion and a pilot seat; a pilot valve element that is releasable from the pilot seat and opens and closes the pilot passage by releas- ing it; a solenoid that moves the pilot valve element in an opening direction that opens the pilot passage; a coil spring that urges the pilot valve element in a closing direction that closes the pilot passage; and a spring bearing member interposed between the coil spring and the pilot valve element, the spring bearing member abutting against the pilot valve element so as to be rotatable relative to the pilot valve element about a main axis extending in the opening direction.

[0007] According to the first disclosure, the spring bearing member abuts against the pilot valve body so as to be rotatable about the main axis. This prevents a torsional load from being transmitted from the spring bearing member to the pilot valve body. This reduces the torsional load acting on the pilot seat, thereby improving the durability of the pilot seat.

[0008] a main valve element accommodated in the housing so as to be able to open and close the valve passage, the main valve element including a pilot passage connected to the first flow path element and the second flow path element and a pilot seat; a pilot valve element capable of being seated on and removed from the pilot seat and opening and closing the pilot passage by being seated on and removed from the pilot seat; a solenoid that moves the pilot valve element in an opening direction to open the pilot passage; and a coil spring that biases the pilot valve element in a closing direction to close the pilot passage. The main valve element further has a piston insertion hole extending along the opening direction, the piston insertion hole has an engagement groove extending along the opening direction, and the pilot valve element is inserted into the piston insertion hole so as to be able to move in the opening direction and the closing direction, and has an engagement protrusion that engages with the engagement groove.

[0009] According to the second disclosure, the pilot valve element has an engaging protrusion that engages with the engaging groove of the piston insertion hole. Therefore, the pilot valve element is restricted from rotating about the main axis relative to the main valve element. That is, the pilot valve element is restricted from rotating relative to the pilot seat. This makes it possible to restrict torsional loads from acting on the pilot seat, thereby improving the durability of the pilot seat.

[0010] According to the first and second disclosures, the durability of the pilot seat can be improved.

[0011] The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.

[0012] Fig. 1 is a cross-sectional view showing a gas solenoid valve according to a first embodiment of the present disclosure. Fig. 2 is an enlarged cross-sectional view showing an enlarged region X of the gas solenoid valve of Fig. 1. Fig. 3 is an enlarged cross-sectional view showing an enlarged region Y of the gas solenoid valve of Fig. 2. Fig. 4 is an enlarged cross-sectional view showing an enlarged region Z of the gas solenoid valve of Fig. 2. Fig. 5 is a cross-sectional view showing a gas flow immediately after a solenoid is operated in the gas solenoid valve. Fig. 6 is a cross-sectional view showing a gas flow when a main valve element is operated in the gas solenoid valve. Fig. 7 is a cross-sectional view showing a gas solenoid valve according to a second embodiment of the present disclosure. Fig. 8 is a cross-sectional view showing a gas solenoid valve according to a third embodiment of the present disclosure.

[0013] Hereinafter, gas solenoid valves 1, 1A, and 1B according to first to third embodiments of the present disclosure will be described with reference to the drawings. Note that the concepts of directions used in the following description are used for convenience of explanation and do not limit the orientation of the configuration of the present disclosure to those directions. Furthermore, the gas solenoid valves 1, 1A, and 1B described below are merely one embodiment of the present disclosure. Therefore, the present disclosure is not limited to the embodiments, and additions, deletions, and modifications are possible within the scope of the present disclosure.

[0014] <Gas Electromagnetic Valve> The gas electromagnetic valve 1 of the first embodiment shown in FIG. 1 controls the flow of gas. The gas to be controlled is, for example, a high-pressure gas (e.g., 30 MPa or higher). In this embodiment, the gas to be controlled by the gas electromagnetic valve 1 is, for example, hydrogen gas at 70 MPa or higher. However, the gas is not necessarily limited to high-pressure gas, and is not limited to hydrogen. The gas may be other gases, such as helium, nitrogen, and natural gas. The gas electromagnetic valve 1 is, for example, located in a flow path through which gas flows. The gas electromagnetic valve 1 is provided, for example, in a tank valve provided in a pressure vessel (e.g., a high-pressure tank) to be filled with gas, and is located in a flow path for filling and discharging gas connected to the pressure vessel. The gas electromagnetic valve 1 controls the filling of gas into the high-pressure tank and the discharging of gas from the high-pressure tank. More specifically, the gas solenoid valve 1 includes a housing 10, a main valve body 11, a first spring member 12, a pilot piston 13, a solenoid 14, a second spring member 15, and a spring bearing member 16. More specifically, the gas solenoid valve 1 includes a guide member 17, a plunger 18, and a case 19.

[0015] <Housing> The housing 10 includes an insertion hole 10a and a valve passage 10b. The insertion hole 10a is a bottomed hole extending along a predetermined axis L1, which is an example of a main axis. The insertion hole 10a also has a step 10f, for example, in the axially intermediate portion, and a small-diameter portion 10g located on one axial side (i.e., the bottom side) of the step 10f is formed with a smaller diameter than a large-diameter portion 10h located on the other axial side (i.e., the opening side). Here, the axial direction is the direction in which the axis L1 extends. The aforementioned components 11 to 19 are inserted through the insertion hole 10a.

[0016] The valve passage 10b is interposed in the aforementioned flow path, and gas flows through the valve passage 10b. More specifically, the valve passage 10b has a first flow path portion 10c and a second flow path portion 10d. The first flow path portion 10c is connected to, for example, a high-pressure tank, and the second flow path portion 10d is connected to a gas consumer (not shown), such as a fuel cell or a gas engine. However, the first flow path portion 10c and the second flow path portion 10d do not necessarily need to be connected to the high-pressure tank and the gas consumer, respectively, and may be connected to other tanks, devices, etc. The first flow path portion 10c and the second flow path portion 10d are connected to each other via the insertion hole 10a. In this embodiment, the first flow path portion 10c opens at the bottom side of the inner circumferential surface of the small-diameter portion 10g of the insertion hole 10a and extends radially outward from the inner circumferential surface. The second flow path portion 10d opens at the bottom surface of the insertion hole 10a and extends from the bottom surface in one axial direction along the axis L1. A main valve seat 10e is formed at the bottom surface of the insertion hole 10a so as to surround a valve port 10j, which is the opening of the second flow path portion 10d. In this embodiment, the main valve seat 10e is formed in a tapered shape that narrows toward one axial direction.

[0017] <Guide Member> The guide member 17 accommodates the main valve element 11 and plunger 18 (described later in detail) in an axially guideable manner. More specifically, the guide member 17 is a metallic tubular member, and the main valve element 11 and plunger 18 are accommodated in its inner bore 17a. The guide member 17 is inserted into the insertion hole 10a in a sealed state. More specifically, one axial end portion of the guide member 17 is fitted into the small-diameter portion 10g in a sealed state, and the remaining portion protrudes into the large-diameter portion 10h. One axial end face of the guide member 17 abuts against the bottom surface of the insertion hole 10a and surrounds the valve port 10j. The guide member 17 is fixed to the insertion hole 10a by being sandwiched between a yoke 27 (described later in detail) and the bottom surface of the insertion hole 10a (i.e., the housing 10). The guide member 17 has a portion on one axial end side formed to have a smaller diameter than the small diameter portion 10g, and an annular space 23 is formed between the guide member 17 and the small diameter portion 10g.

[0018] As shown in FIG. 2 , the guide member 17 includes a first communication passage 17b and a second communication passage 17c. The first communication passage 17b and the second communication passage 17c are each formed at one axial end of the guide member 17. More specifically, the inner bore 17a of the guide member 17 is formed with a smaller diameter at one axial end than at the other axial end. That is, the guide member 17 has an inward flange 17d at one axial end, and the first communication passage 17b is formed in the inward flange 17d. The second communication passage 17c is located on the other axial side of the first communication passage 17b. The first communication passage 17b and the second communication passage 17c thus formed both communicate between the inner bore 17a of the guide member 17 and the annular space 23. Therefore, the first flow path portion 10c is connected to the first communication passage 17b and the second communication passage 17c via the annular space 23, and is also connected to the inner hole 17a of the guide member 17 via the first communication passage 17b and the second communication passage 17c. Furthermore, the first flow path portion 10c is connected to the second flow path portion 10d via the inner hole 17a of the guide member 17. In other words, the first flow path portion 10c is connected to the second flow path portion 10d via the insertion hole 10a. Although not shown in detail, the first communication passages 17b and second communication passages 17c configured in this manner are formed in the guide member 17, for example, four each.

[0019] <Main Valve Body> As shown in Figure 2, the main valve body 11 is housed in the housing 10 so as to be movable in the axial direction, and opens and closes the valve passage 10b as it moves. More specifically, the main valve body 11 is housed in the inner hole 17a of the guide member 17 so as to be movable in the axial direction. As the main valve body 11 moves, it causes the valve head 11a to seat on and separate from the main valve seat 10e. This causes the second flow path portion 10d to be opened and closed by the main valve body 11. In other words, the valve passage 10b is opened and closed by the main valve body 11.

[0020] Furthermore, when the main valve element 11 is housed in the inner bore 17a of the guide member 17, it forms the following space between itself and the guide member 17: The main valve element 11 forms an annular passage 17e between itself and the inward flange 17d of the guide member 17, and forms a spring accommodating space 17f in the axially intermediate portion of the guide member 17. More specifically, the outer diameter of the main valve element 11 increases in stages from the valve head 11a toward the other axial side, and the annular passage 17e is formed between the inward flange 17d and the valve head 11a. The main valve element 11 also forms a spring accommodating space 17f between itself and the guide member 17 in the axially intermediate portion.

[0021] The annular passage 17e is an annular passage surrounding the valve head 11a of the main valve element 11. The annular passage 17e is connected to the first communication passage 17b, and is connected to the annular space 23 and the first flow path portion 10c via the first communication passage 17b. When the main valve element 11 leaves the main valve seat 10e, the annular passage 17e is connected to the second flow path portion 10d. This opens the valve passage 10b.

[0022] The spring accommodating space 17f is an annular space and accommodates the first spring member 12, which will be described in detail later. The spring accommodating space 17f is also connected to the second communication passage 17c, and is connected to the annular space 23 and the first flow path portion 10c via the second communication passage 17c. Furthermore, a plurality of communication grooves 11b are formed on the outer peripheral surface of the main valve body 11 on the other axial side, and the spring accommodating space 17f is connected to the plurality of communication grooves 11b.

[0023] The main valve element 11 also has a pilot passage 11c and a piston insertion hole 11d. The pilot passage 11c connects the first flow path portion 10c and the second flow path portion 10d. More specifically, the pilot passage 11c extends along the axis of the main valve element 11, which in this embodiment is the axis L1, and its opening faces the second flow path portion 10d. The piston insertion hole 11d also extends along the axis L1 and is formed in the main valve element 11 on the other axial side of the pilot passage 11c. The piston insertion hole 11d is connected to the pilot passage 11c, and in this embodiment, the pilot passage 11c is connected to the first flow path portion 10c via the piston insertion hole 11d, the inner hole 17a of the guide member 17, the communicating groove 11b, the spring accommodating space 17f, the second communicating passage 17c, and the annular space 23. The pilot passage 11c is connected to the piston insertion hole 11d via a pilot valve port 11f. A pilot seat 11g is formed around the pilot valve port 11f in the main valve body 11. A pilot piston 13, which will be described in detail later, is seated on and removed from the pilot seat 11g.

[0024] <First Spring Member> The first spring member 12, which is an example of a biasing member, biases the main valve element 11 in an opening direction that opens the valve passage 10b. The opening direction is, for example, a direction in which the main valve element 11 separates from the main valve seat 10e, which is the other axial direction in this embodiment. More specifically, the first spring member 12 is, for example, a coil spring, and is housed in the spring accommodating space 17f while being sheathed around the middle portion of the main valve element 11. The first spring member 12 biases the other axial side portion of the main valve element 11 in the opening direction.

[0025] <Pilot Piston> The pilot piston 13, which is an example of a pilot valve element, seats and releases from a pilot seat 11g, also shown in FIG. 3, and opens and closes the pilot passage 11c by seating and releasing. More specifically, the pilot piston 13 is housed in the piston insertion hole 11d of the main valve element 11 so as to be movable in the opening and closing direction. In this embodiment, a tip end portion of the pilot piston 13 is housed in the piston insertion hole 11d so as to be movable, and further, the tip end portion seats on the pilot seat 11g. The opening and closing direction is bidirectional, including an opening direction that opens the pilot passage 11c and a closing direction that closes the pilot passage 11c. In this embodiment, the opening and closing direction coincides with the axial direction, which is the direction along the axis L1.

[0026] Furthermore, rotation of the pilot piston 13 about the axis L1 relative to the main valve body 11 is restricted. More specifically, the pilot piston 13 is connected to the main valve body 11 by a first pin member 21. In this embodiment, the pilot piston 13 has a through hole 13a extending radially at its tip end portion, into which the first pin member 21 is loosely fitted. Both ends of the first pin member 21, which is an example of a connecting member, protrude from the through hole 13a and are respectively fitted into the main valve body 11. As a result, the pilot piston 13 is engaged with the main valve body 11 in a state where it is movable axially relative to the main valve body 11 and where its rotation about the axis L1 is restricted.

[0027] <Plunger> The plunger 18 shown in FIG. 2 cooperates with the solenoid 14, which will be described in detail later, to move the pilot piston 13 in the other axial direction. More specifically, the plunger 18 is a cylindrical member made of a magnetic material. The plunger 18 is housed in the insertion hole 10a so as to be movable in the axial direction. More specifically, the plunger 18 is inserted into the guide member 17 so as to be slidable in the axial direction. The pilot piston 13 is movably inserted into the inner hole 18a of the plunger 18. More specifically, the portion of the pilot piston 13 protruding from the main valve body 11, i.e., the portion from the middle portion of the pilot piston 13 to the other axial end, is inserted into the inner hole 18a of the plunger 18. The plunger 18 is connected to the pilot piston 13 by a second pin member 22. In this embodiment, the pilot piston 13 has a through hole 13b extending radially in the middle portion, into which the second pin member 22 is fitted. Both ends of the second pin member 22 protrude from the through hole 13b and are loosely fitted in the plunger 18. Therefore, the pilot piston 13 is engaged with the plunger 18 so as to be movable relative to the plunger 18 in the axial direction.

[0028] <Solenoid> The solenoid 14 shown in FIG. 1 moves the pilot piston 13 in the opening direction depending on the state of current flow. More specifically, the solenoid 14 is inserted into the housing 10. In this embodiment, the solenoid 14 is inserted into the large diameter portion 10h of the insertion hole 10a with a case 19 (described later) attached to the solenoid 14. The solenoid 14 generates a magnetic field depending on the state of current flow, attracting the plunger 18 in the other axial direction and moving the pilot piston 13 in the opening direction via the plunger 18. More specifically, the solenoid 14 includes a coil member 25 and a fixed magnetic pole 26.

[0029] The coil member 25 generates a magnetic field when energized. More specifically, the coil member 25 has a coil bobbin 25a and a coil wire 25b, and is configured by winding the coil wire 25b around the cylindrical coil bobbin 25a. The coil member 25 is inserted through the insertion hole 10a. More specifically, the coil member 25 is inserted through the large diameter portion 10h of the housing 10 with the case 19, which will be described in detail later, attached thereto. In this embodiment, the coil member 25 is inserted through the large diameter portion 10h with the yoke 27 disposed on one axial side thereof and pressed against the step portion 10f via the yoke 27. Furthermore, the coil member 25 has a guide member 17 inserted through its inner hole.

[0030] The fixed magnetic pole 26 cooperates with the coil member 25 to generate an electromagnetic force, attracting the plunger 18 in the other axial direction. More specifically, the fixed magnetic pole 26 is made of a ferromagnetic material and is inserted into the coil member 25 (more specifically, the guide member 17, which is inserted into the coil member 25). More specifically, the fixed magnetic pole 26 has a small diameter portion 26a and a large diameter portion 26b. The small diameter portion 26a is inserted into the coil member 25. More specifically, the small diameter portion 26a extends to the inner hole 17a of the guide member 17 and is inserted into the inner hole 17a of the guide member 17 in a sealed state. Furthermore, the small diameter portion 26a is located on the other axial side of the plunger 18 within the inner hole 17a of the guide member 17. The small diameter portion 26a has a spring receiving recess 26c at its tip, and the spring receiving recess 26c is formed at a position corresponding to the inner hole 18a of the plunger 18. The large diameter portion 26b protrudes from the coil member 25 in the other axial direction and is threadedly engaged with the case 19, which will be described in detail later.

[0031] <Case> The case 19 is fitted to the solenoid 14 and threadedly engaged with the large-diameter portion 10h of the housing 10. More specifically, the case 19 accommodates a coil member 25. A fixed magnetic pole 26 is threadedly engaged with an opening on the other axial side of the case 19, which is closed by the fixed magnetic pole 26. In this embodiment, the case 19 has an inward flange 19a on the other axial side of its inner circumferential surface. The coil member 25 is positioned axially on one side of the inward flange 19a and is sandwiched together with the yoke 27 between the step portion 10f and the inward flange 19a. The fixed magnetic pole 26 is threadedly engaged with the inward flange 19a so as to close the opening on the other axial side. The case 19 and the fixed magnetic pole 26 form a magnetic circuit.

[0032] <Second Spring Member> The second spring member 15, which is an example of a coil spring, biases the pilot piston 13 in a closing direction, which is a direction against the electromagnetic force of the solenoid 14, as shown in FIG. 2 . As described above, the second spring member 15 is a coil spring. The second spring member 15 is inserted into the plunger 18 and disposed on the other axial side of the pilot piston 13 in a compressed state. More specifically, the second spring member 15 is disposed in the plunger 18 between the pilot piston 13 and the fixed magnetic pole 26 in a compressed state, and the other axial end of the second spring member 15 is received by the spring receiving recess 26 c of the fixed magnetic pole 26. Furthermore, the one axial end of the second spring member 15 is received by the spring receiving member 16, which will be described in detail later, and the second spring member 15 biases the pilot piston 13 via the spring receiving member 16.

[0033] <Spring bearing member> The spring bearing member 16 is interposed between the second spring member 15 and the pilot piston 13. The spring bearing member 16 abuts against the pilot piston 13 so as to be relatively rotatable about the axis L1. Explaining in more detail, the spring bearing member 16 is interposed between the second spring member 15 and the pilot piston 13 and is inserted into the guide member 17 so as to be axially movable. The spring bearing member 16 receives one axial end of the second spring member 15 on the other axial side, and has one end on the one axial side abutting against an abutment surface 13c of the pilot piston 13. The abutment surface 13c is a surface of the pilot piston 13 that faces the spring bearing member 16, and is the end face on the other axial side in this embodiment.

[0034] 4, the spring receiving member 16 has a contact portion 16a that contacts the pilot piston 13. Explaining in more detail, the spring receiving member 16 is, for example, a cylindrical member and has a main body portion 16b and a rod portion 16c. The spring receiving member 16 has the contact portion 16a on the main body portion 16b. The configuration of the spring receiving member 16 will be explained in more detail below.

[0035] The main body 16b of the spring bearing member 16 is formed in a cylindrical shape and is inserted into the guide member 17 so as to be slidable in the axial direction. One axial end of the main body 16b abuts against the abutment surface 13c of the pilot piston 13, and has an abutment portion 16a at that axial end. More specifically, the one axial end of the main body 16b is formed so as to protrude in one axial direction around the axis L1, and has, for example, a truncated cone shape. The abutment portion 16a is the tip of the portion protruding in one axial direction and abuts against the abutment surface 13c of the pilot piston 13, and abuts against the abutment surface 13c so as to be rotatable about the axis L1.

[0036] More specifically, the abutment portion 16a is formed, for example, in a circular shape when viewed from one axial direction. The outer diameter r1 of the abutment portion 16a is smaller than the seat diameter r2 of the pilot seat 11g, as shown in FIG. 2 . In this embodiment, the seat diameter r2 of the pilot seat 11g is, for example, the average diameter between the minimum and maximum diameters of the pilot seat 11g. However, the seat diameter r2 of the pilot seat 11g is not limited to the aforementioned average diameter and may be the minimum or maximum diameter. The rod portion 16c extends from the main body portion 16b in the other axial direction. The spring receiving member 16 has the second spring member 15 mounted on the rod portion 16c, and one axial end of the second spring member 15 is supported by the main body portion 16b.

[0037] Furthermore, the contact portion 16a of the spring bearing member 16 is subjected to a surface treatment that improves the slipperiness of the bare surface. More specifically, the contact portion 16a of the spring bearing member 16 is subjected to a surface treatment using fluorine-containing plating. In this embodiment, the entire outer surface of the spring bearing member 16 is subjected to a surface treatment using fluorine-containing plating. Note that the surface treatment applied to the entire outer surface of the spring bearing member 16 is not limited to fluorine-containing plating, and other surface treatments may be used as long as they improve the slipperiness of the bare surface. Furthermore, the portion of the spring bearing member 16 that is subjected to the surface treatment is not limited to the entire outer surface of the spring bearing member 16, and may be a portion including the contact portion 16a.

[0038] The spring bearing member 16 configured in this manner is biased by the second spring member 15, and applies the biasing force of the second spring member 15 to the pilot piston 13 in contact therewith. On the other hand, because the second spring member 15 is a coil spring, it is twisted when compressed and untwisted when expanded. The second spring member 15 expands when biasing the pilot piston 13 via the spring bearing member 16, and is therefore untwisted, applying a torsional load to the spring bearing member 16. On the other hand, because the spring bearing member 16 abuts against the pilot piston 13 so as to be able to rotate relatively, it is possible to prevent the torsional load from acting on the pilot piston 13.

[0039] <Operation of gas solenoid valve> In the gas solenoid valve 1, in a non-energized state as shown in Fig. 1, the pilot piston 13 is pressed against and seated on the pilot seat 11g of the main valve element 11 by the biasing force of the second spring member 15. Furthermore, as the pilot piston 13 is pressed against the pilot seat 11g, the main valve element 11 receives the biasing force of the second spring member 15 in the closing direction via the pilot piston 13. As a result, the main valve element 11 is seated on the main valve seat 10e, and the valve passage 10b is closed.

[0040] When high-pressure gas (more specifically, gas with a higher pressure than the gas in the first flow path portion 10c) is introduced into the second flow path portion 10d with the valve passage 10b closed, the gas solenoid valve 1 operates as follows. Specifically, the high-pressure gas lifts the main valve element 11 against the biasing force of the second spring member 15. This opens the valve passage 10b. Then, gas is introduced from the second flow path portion 10d through the insertion hole 10a (more specifically, the valve port 10j, the annular passage 17e, the first communication passage 17b, and the annular space 23) to the first flow path portion 10c. When the differential pressure between the gas pressure in the first flow path portion 10c and the gas pressure in the second flow path portion 10d reaches a predetermined value, the main valve element 11 seats on the main valve seat 10e. This closes the valve passage 10b, stopping the flow of gas from the second flow path portion 10d to the first flow path portion 10c.

[0041] Next, when the solenoid 14 (more specifically, the coil member 25) is energized, an electromagnetic force is generated, and the main valve element 11 moves in the opening direction. As a result, the main valve element 11 moves away from the main valve seat 10e, as shown in FIG. 5. More specifically, when the solenoid 14 is energized, the plunger 18 is attracted to the fixed magnetic pole 26 by the electromagnetic force. This causes the plunger 18 to lift the pilot piston 13 via the second pin member 22, and the pilot piston 13 is then lifted against the biasing force of the second spring member 15. This opens the pilot passage 11c, connecting the first flow path portion 10c and the second flow path portion 10d. More specifically, the first flow path portion 10c is connected to the second flow path portion 10d via the annular space 23, the second communication passage 17c, the spring accommodating space 17f, the communication groove 11b, the inner hole 17a of the guide member 17, the piston insertion hole 11d, and the pilot passage 11c (see the thick line gas flow in FIG. 5). Therefore, the difference between the gas pressure in the insertion hole 10a and the gas pressure in the second flow path portion 10d becomes smaller. This causes the main valve element 11 to be lifted by the first spring member 12. As a result, as shown in FIG. 6, the main valve element 11 moves away from the main valve seat 10e, opening the valve passage 10b. Therefore, the first flow path portion 10c is connected to the second flow path portion 10d via the annular space 23, the first communication passage 17b, and the annular passage 17e, and gas flows through the valve passage 10b from the first flow path portion 10c to the second flow path portion 10d (see the thick line in FIG. 6).

[0042] Furthermore, when the solenoid 14 is de-energized while the valve passage 10b is open, the electromagnetic force acting on the plunger 18 is eliminated. This causes the second spring member 15 to move the pilot piston 13 in the closing direction. As a result, the pilot piston 13 is pressed against and seated on the pilot seat 11g. The second spring member 15 presses the main valve element 11 in the closing direction via the pilot piston 13, causing the main valve element 11 to seat on the main valve seat 10e. This closes the valve passage 10b, stopping the flow of gas from the first flow path portion 10c to the second flow path portion 10d.

[0043] Furthermore, when the pilot passage 11c is closed, the second spring member 15 is extended and thereby twisted back. As a result, a torsional load acts from the second spring member 15 on the spring bearing member 16. On the other hand, the spring bearing member 16 is rotatably in contact with the pilot piston 13. This makes it possible to suppress the torsional load from being transmitted to the pilot piston 13. This makes it possible to suppress the pilot piston 13 from being pressed against the pilot seat 11g while being twisted. Therefore, the torsional load acting on the pilot seat 11g can be reduced, thereby improving the durability of the pilot seat 11g.

[0044] Furthermore, the pilot piston 13 is configured to rotate about the axis L1 relative to the main valve body 11 by the first pin member 21. This prevents the pilot piston 13 from being twisted and pressed against the pilot seat 11g. This reduces the torsional load acting on the pilot seat 11g, further improving the durability of the pilot seat 11g.

[0045] In the gas solenoid valve 1 of the first embodiment, the spring bearing member 16 abuts against the pilot piston 13 so as to be rotatable about the axis L1. This makes it possible to suppress the transmission of a torsional load from the spring bearing member 16 to the pilot piston 13. This reduces the torsional load acting on the pilot seat 11g, thereby improving the durability of the pilot seat 11g.

[0046] Furthermore, in the gas solenoid valve 1 of the first embodiment, the contact portion 16a has an outer diameter r1 that is smaller than the seat diameter r2 of the pilot seat 11g. Therefore, the torsional load that the pilot piston 13 receives from the spring receiving member 16 can be reduced at the contact portion 16a. This further reduces the torsional load acting on the pilot seat 11g, thereby further improving the durability of the pilot seat 11g.

[0047] Furthermore, in the gas solenoid valve 1 of the first embodiment, the pilot piston 13 is restricted from rotating about the axis L1 relative to the main valve body 11. Therefore, the pilot piston 13 is restricted from rotating relative to the pilot seat 11g. This makes it possible to restrict the application of a torsional load to the pilot seat 11g, thereby further improving the durability of the pilot seat 11g.

[0048] Furthermore, in the gas solenoid valve 1 of the first embodiment, the pilot piston 13 is inserted into the piston insertion hole 11d so as to be axially movable, and is connected to the main valve body 11 by the first pin member 21 so as to restrict rotation about the axis L1. Therefore, it is possible to easily enable movement of the pilot piston 13 in the axial direction while restricting rotation about the axis L1 relative to the main valve body 11.

[0049] Furthermore, in the gas solenoid valve 1 of the first embodiment, the contact portion 16a is subjected to a surface treatment that improves the slipperiness of the bare surface, i.e., a surface treatment using fluorine-containing plating. Therefore, it is possible to further suppress the transmission of torsional load from the spring bearing member 16 to the pilot piston 13. This makes it possible to further reduce the torsional load acting on the pilot seat 11g, thereby improving the durability of the pilot seat 11g.

[0050] [Second Embodiment] A gas solenoid valve 1A of a second embodiment shown in Fig. 7 is similar in configuration to the gas solenoid valve 1 of the first embodiment. Therefore, with regard to the configuration of the gas solenoid valve 1A of the second embodiment, differences from the gas solenoid valve 1 of the first embodiment will be mainly described, and the same components will be assigned the same reference numerals and descriptions thereof will be omitted. The same applies to a gas solenoid valve 1B of a third embodiment etc., which will be described later.

[0051] The gas solenoid valve 1A of the second embodiment includes a housing 10, a main valve element 11A, a first spring member 12, a pilot piston 13A, a solenoid 14, a second spring member 15, a spring bearing member 16A, a guide member 17, a plunger 18, a case 19, and a rotating member 30. The main valve element 11A has a piston insertion hole 11Ad. The pilot piston 13A has a distal end portion movably received in the piston insertion hole 11Ad, and its distal end is seated on a pilot seat 11g. The pilot piston 13A is engaged with the piston insertion hole 11Ad so that its rotation about an axis L1 is restricted. More specifically, the cross section of the piston insertion hole 11Ad perpendicular to the axis L1 is formed, for example, in the shape of a rounded rectangle. The tip end portion of the pilot piston 13A also has a cross section perpendicular to the axis L1 that is the same shape as the piston insertion hole 11Ad, i.e., a rounded rectangle. Therefore, the pilot piston 13A is restricted from rotating about the axis L1 relative to the piston insertion hole 11Ad. This prevents the pilot piston 13A from being twisted and pressed against the pilot seat 11g. This reduces the torsional load acting on the pilot seat 11g, thereby improving the durability of the pilot seat 11g.

[0052] A rotating member 30 is provided on the other axial end surface 13c of the pilot piston 13A. The pilot piston 13A abuts against the spring bearing member 16A with the rotating member 30 interposed between the pilot piston 13A and one axial end of the spring bearing member 16A. The rotating member 30 is, for example, a thrust bearing, and allows the spring bearing member 16A to rotate relative to the pilot piston 13A. This allows the spring bearing member 16A to abut against the pilot piston 13A so as to be rotatable relative to the pilot piston 13A around the axis L1. This prevents the torsional load of the second spring member 15 from being transmitted to the pilot piston 13A. This further prevents the pilot piston 13A from being twisted and pressed against the pilot seat 11g. This reduces the torsional load acting on the pilot seat 11g, thereby improving the durability of the pilot seat 11g.

[0053] In the gas solenoid valve 1A of the second embodiment, the pilot piston 13 is inserted into the piston insertion hole 11 d so as to be axially movable, and is engaged with the piston insertion hole 11 d so as to restrict rotation of the pilot piston 13 about the axis L1. Therefore, it is easy to realize a configuration in which the pilot piston 13 is allowed to move in the axial direction while being restricted from rotating about the axis L1 relative to the main valve element 11.

[0054] In addition, the gas electromagnetic valve 1A of the second embodiment has the same functions and effects as the gas electromagnetic valve 1 of the first embodiment.

[0055] 8 includes a housing 10, a main valve element 11B, a first spring member 12, a pilot piston 13B, a solenoid 14, a second spring member 15, a spring bearing member 16, a guide member 17, a plunger 18, and a case 19. The main valve element 11B has a piston insertion hole 11Bd. The piston insertion hole 11Bd has a plurality of engagement grooves 11h. In this embodiment, the piston insertion hole 11Bd has four engagement grooves 11h. The engagement grooves 11h are grooves that are recessed radially in the inner circumferential surface of the piston insertion hole 11Bd and extend along the axis L1. In this embodiment, the four engagement grooves 11h are arranged at intervals from one another in the circumferential direction on the inner circumferential surface of the piston insertion hole 11Bd.

[0056] The pilot piston 13B has a tip end portion slidably accommodated in the piston insertion hole 11Bd, and a tip end portion seated on the pilot seat 11g. The pilot piston 13B engages with the piston insertion hole 11Bd so as to restrict rotation about the axis L1. More specifically, the pilot piston 13B has a plurality of engagement protrusions 13d. In this embodiment, the pilot piston 13B has the same number of engagement protrusions 13d as the engagement grooves 11h, i.e., four. The engagement protrusions 13d are spaced apart from one another and are positioned on the outer circumferential surface of the pilot piston 13B at positions corresponding to the engagement grooves 11h. The engagement protrusions 13d are axially movable within the engagement grooves 11h and engage with the engagement grooves 11h so as to restrict rotation of the pilot piston 13B about the axis L1 relative to the main valve body 11B. In this embodiment, the engagement protrusions 13d, like the engagement grooves 11h, extend axially on the outer circumferential surface of the pilot piston 13B. The pilot piston 13B configured in this manner is restricted from rotating about the axis L1 relative to the piston insertion hole 11Bd. This prevents the pilot piston 13B from being twisted and pressed against the pilot seat 11g. This reduces the torsional load acting on the pilot seat 11g, thereby improving the durability of the pilot seat 11g.

[0057] In the gas solenoid valve 1B of the third embodiment, the pilot piston 13B has an engaging protrusion 13d that engages with the engaging groove 11h of the piston insertion hole 11d. Therefore, a structure that restricts the rotation of the pilot piston 13B can be easily formed.

[0058] In addition, the gas electromagnetic valve 1B of the third embodiment has the same functions and effects as the gas electromagnetic valve 1 of the first embodiment.

[0059] [Other Embodiments] In the gas solenoid valves 1, 1A, and 1B of this embodiment, a coil spring is used as the second spring member 15, but a spring that can generate an axial biasing force without generating a torsional load, such as a disc spring, may be used. In this case, the gas solenoid valves 1, 1A, and 1B do not necessarily require the spring receiving member 16, 16A, and the disc spring or the like may be attached directly to the pilot piston 13. Also, in the gas solenoid valves 1, 1A, and 1B, the plunger 18 and the pilot piston 13, 13A, and 13B are connected by the second pin member 22, but this connection is not necessarily required. For example, the plunger 18 may be engaged with the pilot piston 13, 13A, and 13B so as to be able to lift it up, and any configuration may be used as long as the plunger 18 can move in the opening direction to unseat the pilot piston 13, 13A, and 13B.

[0060] Furthermore, in the gas solenoid valve 1, the outer diameter r1 of the abutting portion 16a of the spring receiving member 16 may be larger than the seat diameter r2 of the pilot seat 11g, or one axial end of the spring receiving member 16 may be formed flat so that the entire axial end constitutes the abutting portion 16a. Also, in the gas solenoid valves 1 and 1B, the abutting portion 16a is formed on the spring receiving member 16, but it may also be formed on the pilot piston 13, or both the spring receiving member 16 and the pilot piston 13 may be provided. If both are provided, the two abutting portions are configured to abut against each other, for example.

[0061] In the gas solenoid valves 1, 1A, and 1B, the structure that restricts the rotation of the pilot piston 13 about the axis L1 relative to the main valve element 11 is not limited to the structure described above, and other structures may be used. Furthermore, in the gas solenoid valves 1, 1A, and 1B, the pilot piston 13 does not necessarily have to be restricted from rotating about the axis L1 relative to the main valve element 11, and may rotate about the axis L1 relative to the main valve element 11. Furthermore, the pilot piston 13 does not necessarily have to be inserted into the piston insertion holes 11d, 11Ad, and 11Bd of the main valve element 11, and may be structured to seat on the end surface of the main valve element 11 on the other axial side.

[0062] <Exemplary Embodiment> A solenoid valve for gas in a first aspect includes: a housing including a valve passage having a first flow path portion and a second flow path portion; a main valve element accommodated in the housing to open and close the valve passage, the main valve element including a pilot passage connected to the first flow path portion and the second flow path portion and a pilot seat; a pilot valve element that is releasable from the pilot seat and opens and closes the pilot passage by being releasable from the pilot seat; a solenoid that moves the pilot valve element in an opening direction that opens the pilot passage; a coil spring that biases the pilot valve element in a closing direction that closes the pilot passage; and a spring bearing member interposed between the coil spring and the pilot valve element, the spring bearing member abutting against the pilot valve element so as to be rotatable relative to the pilot valve element about a main axis extending in the opening direction.

[0063] According to the above aspect, the spring bearing member abuts against the pilot valve body so as to be rotatable about the main axis. Therefore, it is possible to suppress the transmission of a torsional load from the spring bearing member to the pilot valve body. This reduces the torsional load acting on the pilot seat, thereby improving the durability of the pilot seat.

[0064] In a second aspect, the gas solenoid valve is the gas solenoid valve of the first aspect, wherein at least one of the spring receiving member and the pilot valve body includes an abutment portion that abuts against the other, and the abutment portion has an outer diameter smaller than a seat diameter of the pilot seat.

[0065] According to the above aspect, the abutment portion has an outer diameter smaller than the seat diameter of the pilot seat. Therefore, the torsional load that the pilot valve body receives from the spring receiving member can be reduced at the abutment portion. This further reduces the torsional load acting on the pilot seat, thereby further improving the durability of the pilot seat.

[0066] In a third aspect of the gas solenoid valve, in the gas solenoid valve of the first or second aspect, the pilot valve element is restricted from rotating about the main axis relative to the main valve element.

[0067] According to the above aspect, the pilot valve element is restricted from rotating about the main axis relative to the main valve element. Therefore, the pilot valve element is restricted from rotating relative to the pilot seat. This makes it possible to suppress the application of a torsional load to the pilot seat, thereby further improving the durability of the pilot seat.

[0068] In a fourth aspect, the gas solenoid valve is the gas solenoid valve of any one of the first to third aspects, wherein the main valve body further has a piston insertion hole, and the pilot valve body is inserted into the piston insertion hole so as to be movable in an opening and closing direction, and is connected to the main valve body by a connecting member so as to restrict rotation around the main axis.

[0069] According to the above aspect, the pilot valve element is inserted into the piston insertion hole so as to be movable in the opening and closing directions, and is connected to the main valve element by the connecting member so as to restrict rotation of the pilot valve element about the main axis. Therefore, it is possible to easily realize that the pilot valve element can move in the opening and closing directions while restricting rotation of the pilot valve element about the main axis relative to the main valve element.

[0070] A gas solenoid valve in a fifth aspect is the gas solenoid valve of any one of the first to fourth aspects, wherein the main valve element further has a piston insertion hole extending along the main axis, and the pilot valve element is inserted into the piston insertion hole so as to be movable in an opening / closing direction, and is engaged with the piston insertion hole so as to be restricted from rotating around the main axis.

[0071] According to the above aspect, the pilot valve element is inserted into the piston insertion hole so as to be movable in the opening and closing directions and is engaged with the piston insertion hole so as to restrict rotation of the pilot valve element about the main axis. Therefore, it is possible to easily realize a configuration in which the pilot valve element is movable in the opening and closing directions while being restricted from rotating about the main axis relative to the main valve element.

[0072] A gas solenoid valve in a sixth aspect is the gas solenoid valve of the fifth aspect, wherein the piston insertion hole has an engagement groove extending along the main axis, and the pilot valve body has an engagement protrusion that engages with the engagement groove.

[0073] According to the above aspect, the pilot valve body has an engaging protrusion that engages with the engaging groove of the piston insertion hole, so that a structure for restricting rotation of the pilot valve body can be easily formed.

[0074] A gas solenoid valve in a seventh aspect is the gas solenoid valve of any one of the first to sixth aspects, wherein at least one of the spring receiving member and the pilot valve body includes an abutment portion that abuts against the other, and the abutment portion is subjected to a surface treatment that improves the slipperiness of the bare surface.

[0075] According to the above aspect, the abutment portion is subjected to a surface treatment that improves the slipperiness of the bare surface. This further reduces the transmission of torsional load from the spring bearing member to the pilot valve body. This further reduces the torsional load acting on the pilot seat, thereby improving the durability of the pilot seat.

[0076] In an eighth aspect, a gas solenoid valve includes: a housing including a valve passage having a first flow path portion and a second flow path portion; a main valve element accommodated in the housing so as to be able to open and close the valve passage, the main valve element including a pilot passage connected to the first flow path portion and the second flow path portion and a pilot seat; a pilot valve element capable of being seated on and removed from the pilot seat and opening and closing the pilot passage by being seated on and removed from the pilot seat; a solenoid that moves the pilot valve element in an opening direction to open the pilot passage; and a coil spring that biases the pilot valve element in a closing direction to close the pilot passage. The main valve element further has a piston insertion hole extending along the opening direction, the piston insertion hole has an engagement groove extending along the opening direction, and the pilot valve element is inserted into the piston insertion hole so as to be able to move in the opening direction and the closing direction, and has an engagement protrusion that engages with the engagement groove.

[0077] According to the above aspect, the pilot valve element has an engaging protrusion that engages with the engaging groove of the piston insertion hole. Therefore, rotation of the pilot valve element about the main axis relative to the main valve element is restricted. That is, rotation of the pilot valve element relative to the pilot seat is suppressed. This suppresses torsional load from acting on the pilot seat, thereby improving the durability of the pilot seat.

[0078] From the above description, many modifications and other embodiments of the present invention will be apparent to those skilled in the art. Therefore, the above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present invention. Details of the structure and / or function thereof may be substantially changed without departing from the spirit of the present invention.

Claims

1. A solenoid valve for gas comprising: a housing including a valve passage having a first flow path portion and a second flow path portion; a main valve element contained in the housing to open and close the valve passage, the main valve element including a pilot passage connecting the first flow path portion and the second flow path portion and a pilot seat; a pilot valve element that is releasable from the pilot seat and opens and closes the pilot passage by releas- ing it; a solenoid that moves the pilot valve element in an opening direction that opens the pilot passage; a coil spring that urges the pilot valve element in a closing direction that closes the pilot passage; and a spring bearing member interposed between the coil spring and the pilot valve element, wherein the spring bearing member abuts against the pilot valve element so as to be rotatable relative to the pilot valve element about a main axis extending in the opening direction.

2. A gas solenoid valve as set forth in claim 1, wherein at least one of said spring receiving member and said pilot valve body includes an abutment portion that abuts against the other, and said abutment portion has an outer diameter smaller than the seat diameter of said pilot seat.

3. A gas solenoid valve according to claim 1, wherein the pilot valve element is restricted from rotating about the main axis relative to the main valve element.

4. A gas solenoid valve as described in claim 1, wherein the main valve body further has a piston insertion hole, and the pilot valve body is inserted into the piston insertion hole so as to be movable in the opening and closing direction, and is connected to the main valve body by a connecting member so as to restrict rotation around the main axis.

5. A gas solenoid valve as described in claim 1, wherein the main valve element further has a piston insertion hole extending along the main axis, and the pilot valve element is inserted into the piston insertion hole so as to be movable in the opening and closing direction, and is engaged with the piston insertion hole so as to restrict rotation about the main axis.

6. A gas solenoid valve as set forth in claim 5, wherein the piston insertion hole has an engagement groove extending along the main axis, and the pilot valve body has an engagement protrusion that engages with the engagement groove.

7. A gas solenoid valve as set forth in claim 1, wherein at least one of the spring receiving member and the pilot valve body includes an abutment portion that abuts against the other, and the abutment portion is surface-treated to improve the slipperiness of the bare surface.

8. A solenoid valve for gas comprising: a housing including a valve passage having a first flow path portion and a second flow path portion; a main valve element accommodated in the housing so as to be able to open and close the valve passage, and including a pilot passage connecting the first flow path portion and the second flow path portion and a pilot seat; a pilot valve element capable of being seated on and removed from the pilot seat and opening and closing the pilot passage by being seated on and removed from the pilot seat; a solenoid that moves the pilot valve element in an opening direction to open the pilot passage; and a coil spring that urges the pilot valve element in a closing direction to close the pilot passage; the main valve element further having a piston insertion hole extending along the opening direction, the piston insertion hole having an engagement groove extending along the opening direction, and the pilot valve element being inserted into the piston insertion hole so as to be able to move in the opening direction and the closing direction, and having an engagement protrusion that engages with the engagement groove.

Images