A pressure stabilizing valve for a gas flare

Abstract

The utility model relates to gas torch technical field, and specifically disclose a kind of pressure stabilizing valve of gas torch, including film piece and lower spring seat, the center of one side of film piece towards lower spring seat is provided with buckle, the center of bottom surface of lower spring seat is provided with clamping hole, after the buckle on film piece is inserted into the clamping hole on lower spring seat, film piece and lower spring seat are connected as a whole. Lower spring seat and film piece can be connected as a whole by the structure of buckle and clamping hole in advance, before being installed in valve body, by forming a whole with lower spring seat and film piece in advance, and forming centring assembly, so as to facilitate the installation of the two components whole in valve body, avoid the need to adjust centring position repeatedly when installing one by one, assembly efficiency is high;At the same time, since the centring position between the two can be ensured, gas leakage phenomenon can be avoided, the fuel pressure before burner is guaranteed stable, so as to ensure the flame stability of gas torch.

Description

Technical Field

[0001] This utility model relates to the field of gas torch technology, and in particular to a pressure regulating valve for gas torches. Background Technology

[0002] Gas fuels on the market are generally made by vaporizing liquid fuel before combustion. However, gas torches are limited by their size and do not have enough space for fuel vaporization. Therefore, the fuel supplied for combustion is often in a gas-liquid mixture. The liquid fuel can be vaporized at any uncertain location, which causes the fuel pressure in front of the burner to fluctuate, resulting in an extremely unstable flame. To address the aforementioned issues, Chinese patent CN201680019U discloses a gas torch pressure regulating valve, comprising a valve body, an inlet assembly, a gas on / off assembly, a valve core assembly, a pressure regulating assembly, a pressure cap, and an outlet rod. The valve body further includes an interconnected airflow chamber and a pressure regulating chamber. The inlet assembly is mounted at one end of the airflow chamber, and the gas on / off assembly passes through the valve body, with its other end connected to the inlet assembly. A valve core assembly is installed between the airflow chamber and the pressure regulating chamber. A pressure regulating assembly is installed in the pressure regulating chamber and connected to the valve core assembly. The upper opening of the pressure regulating chamber is sealed by a pressure cap, and the lower part of the pressure regulating chamber is connected to the outlet rod. This gas torch pressure regulating valve can automatically adjust the fuel outlet opening degree when the fuel pressure changes, thus maintaining a relatively stable flame. However, during the assembly of the aforementioned pressure regulating valve's pressure regulating component, the diaphragm and the lower spring seat are installed sequentially. During installation, the diaphragm and the lower spring seat must be aligned. If they are not aligned, gas leakage will occur, causing the fuel pressure in front of the burner to fluctuate, and the flame of the gas torch to become extremely unstable. In addition, the need to strictly ensure the alignment of the diaphragm and the lower spring seat during installation increases the difficulty of assembly and reduces assembly efficiency. Utility Model Content

[0003] The present invention aims to solve the technical problems existing in the prior art and provide a pressure regulating valve for a gas torch that is easy to assemble and ensures stable fuel pressure and flame before the burner.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0005] The present invention discloses a pressure regulating valve for a gas torch, comprising a diaphragm and a lower spring seat. A buckle is provided at the center of the side of the diaphragm facing the lower spring seat, and a locking hole is provided at the center of the bottom surface of the lower spring seat. After the buckle on the diaphragm is engaged with the locking hole on the lower spring seat, the diaphragm and the lower spring seat are connected as one unit.

[0006] The pressure regulating valve of the gas torch of this utility model has a lower spring seat and a diaphragm component that can be pre-connected as a whole through a snap-fit ​​and snap-hole structure. Before installation on the valve body, by pre-forming the lower spring seat and the diaphragm component into a whole and aligning them, it is easier to install these two components together in the valve body, avoiding the need for repeated adjustment of the alignment position when installing them one by one, thus improving assembly efficiency. At the same time, since the alignment position between the two can be ensured, gas leakage can be avoided, ensuring stable fuel pressure before the burner, thereby ensuring a stable flame of the gas torch.

[0007] Furthermore, the buckle includes a body connected to the film and a head connected to one end of the body facing the lower spring seat. The diameter of the head is larger than the diameter of the body and also larger than the diameter of the locking hole. An annular locking groove is formed between the head and the film. After the buckle and the locking hole are assembled, the edge of the locking hole is embedded in the annular locking groove, and the bottom surface of the head of the buckle contacts the bottom surface of the lower spring seat.

[0008] Furthermore, the head sidewall of the buckle is provided with an annular bevel.

[0009] Furthermore, the height of the annular groove is the same as the thickness of the bottom surface of the lower spring seat.

[0010] Furthermore, the body of the buckle penetrates the diaphragm and forms a positioning protrusion on the side of the diaphragm facing away from the lower spring seat; the pressure regulating valve of the gas torch also includes a top plate, the center of the side of the top plate facing the diaphragm is recessed to the other side to form a positioning groove, and a boss is formed on the other side of the top plate. When the diaphragm and the lower spring seat are connected to form an integral part and installed in the valve body, the positioning protrusion is inserted into the positioning groove.

[0011] Furthermore, a valve core assembly is provided in the middle section of the valve body. The valve core assembly includes a threaded sleeve, in which a first push rod seat that can move axially along the threaded sleeve is provided. A first push rod is integrally formed on the first push rod seat. After the first push rod passes through the threaded sleeve, the end of the first push rod abuts against the boss of the top plate. A receiving groove is provided on the bottom surface of the first push rod seat, and a return spring is provided in the receiving groove. A support plate is provided below the receiving groove, and one end of the return spring passes through the receiving groove and abuts against the support plate.

[0012] Furthermore, one side of the film member is partially recessed towards the other side to form an annular groove on one side of the film member and an annular protrusion on the other side.

[0013] Furthermore, the annular protrusion is formed on the side of the thin film member opposite to the lower spring seat.

[0014] Furthermore, it also includes a pressure cap, which is screwed into the top opening of the valve body and closes the top opening of the valve body; a sleeve is provided below the pressure cap and inside the valve body, the lower spring seat and the diaphragm are both provided inside the valve body, the sleeve surrounds the lower spring seat, a first annular stepped surface is provided on the inner wall of the valve body, and the bottom end of the sleeve presses the edge of the diaphragm onto the first annular stepped surface.

[0015] Furthermore, it also includes a gas on / off assembly, which is located in the lower section of the valve body. The gas on / off assembly includes a horizontally arranged rotating rod, one end of which passes through the valve body and extends to the outside of the valve body. The side wall of the rotating rod is provided with two annular sealing grooves at intervals. A sealing ring is fitted in each annular sealing groove, and a portion of the sealing ring protrudes from the annular sealing groove and abuts against the wall surface of the valve body. Attached Figure Description

[0016] The above and other objects, features, and advantages of this invention will become clearer through a more detailed description of the preferred embodiments shown in the accompanying drawings. The same reference numerals indicate the same parts throughout the drawings, and the drawings are not intentionally drawn to scale with actual dimensions; the focus is on illustrating the gist of this invention.

[0017] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0018] Figure 2 This is a sectional view.

[0019] Figure 3 This is a schematic diagram showing the assembly state of the lower spring seat, diaphragm component, and top plate.

[0020] Figure 4 for Figure 3 A schematic diagram showing the decomposition from different directions.

[0021] Figure 5 for Figure 2 A magnified view of part A in the middle. Detailed Implementation

[0022] To facilitate understanding of this utility model, a more comprehensive description of this utility model will be given below with reference to the accompanying drawings.

[0023] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to and integrated with the other component, or there may be an intervening component present. The terms "mounted," "one end," "the other end," and similar expressions used in this document are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] This utility model specifically provides an embodiment of a pressure regulating valve for a gas torch, see [link to embodiment]. Figure 1-4 The assembly includes a diaphragm component 1 and a lower spring seat 2. A buckle is provided at the center of the side of the diaphragm component 1 facing the lower spring seat 2, and a locking hole 3 is provided at the center of the bottom surface of the lower spring seat 2. After the buckle on the diaphragm component 1 engages with the locking hole 3 on the lower spring seat 2, the diaphragm component 1 and the lower spring seat 2 are connected as a whole. The lower spring seat 2 and the diaphragm component 1 can be pre-connected as a whole through the structure of the buckle and the locking hole 3. Before being installed in the valve body 4, by pre-forming the lower spring seat 2 and the diaphragm component 1 into a whole and forming a centering assembly (the so-called centering assembly means that the center axes of the two coincide, that is, coaxial installation), it is convenient for these two components to be installed together in the valve body 4, avoiding the need to repeatedly adjust the centering position when installing them one by one, thus improving assembly efficiency. At the same time, since the centering position between the two can be ensured, gas leakage can be avoided, ensuring stable fuel pressure in front of the burner, thereby ensuring stable flame of the gas torch.

[0026] In the preferred embodiment, see Figure 2-4 The snap fastener includes a body 5 connected to the diaphragm 1 and a head 6 connected to the end of the body 5 facing the lower spring seat 2. The diameter of the head 6 is larger than the diameter of the body 5, and also larger than the diameter of the locking hole 3. An annular locking groove is formed between the head 6 and the diaphragm 1. After the snap fastener and the locking hole 3 are assembled, the edge of the locking hole 3 is embedded in the annular locking groove, and the bottom surface of the head 6 of the snap fastener contacts the bottom surface of the lower spring seat 2. This structure enables the diaphragm 1 and the lower spring seat 2 to fit tightly together, further improving the alignment after assembly.

[0027] In the preferred embodiment, see Figure 2-4 The head 6 of the buckle has an annular bevel on its side wall, which facilitates the head 6 of the buckle to pass smoothly through the buckle hole 3 and enter the lower spring seat 2.

[0028] In the preferred embodiment, see Figure 2The height of the annular groove is the same as the thickness of the bottom surface of the lower spring seat 2. This further ensures a tight fit between the diaphragm component 1 and the lower spring seat 2, which is beneficial for the alignment of the two after assembly.

[0029] In the preferred embodiment, see Figure 2-4 The buckle 5 penetrates the diaphragm 1 and forms a positioning protrusion on the side of the diaphragm 1 facing away from the lower spring seat 2. The pressure regulating valve of the gas torch also includes a top plate 7. The center of the side of the top plate 7 facing the diaphragm 1 is recessed to the other side to form a positioning groove 8, and a boss 9 is formed on the other side of the top plate 7. When the whole assembly formed by connecting the diaphragm 1 and the lower spring seat 2 is installed in the valve body 4, the positioning protrusion is inserted into the positioning groove 8. Through the cooperation between the positioning protrusion on the diaphragm 1 and the positioning groove 8 on the top plate 7, the whole assembly formed by connecting the diaphragm 1 and the lower spring seat 2 can be quickly and centeredly installed in the valve body 4, further ensuring the alignment of the top plate 7, the diaphragm 1, and the lower spring seat 2, more effectively preventing gas leakage, further ensuring the stability of the fuel pressure before the burner, and thus further ensuring the stability of the flame of the gas torch; at the same time, it also further improves the assembly efficiency.

[0030] In this embodiment, see Figure 1 and 2 It also includes a pressure cap 10, which is screwed into and closes the top opening of the valve body 4. The pressure cap 10 is threaded to the valve body 4, facilitating the disassembly and assembly of the pressure cap 10 for maintenance and replacement of internal parts of the valve body 4. A through hole is provided on the pressure cap 10, and a nut 11 is provided at the top of the through hole. An adjusting screw 12 is screwed vertically into the nut 11, with one end of the adjusting screw 12 entering the valve body 4. An upper spring seat 13 is provided inside the valve body 4 and below the adjusting screw 12. The end of the adjusting screw 12 abuts against the upper spring seat 13. Specifically, a groove is provided on the top surface of the upper spring seat 13, and the end of the adjusting screw 12 abuts against the groove. The lower spring seat 13 is open at one end. The structure is cylindrical, with the upper spring seat 13 located within the lower spring seat 2 and movable up and down along the axial direction of the lower spring seat 2. A pressure-stabilizing spring 14 is provided between the upper spring seat 13 and the lower spring seat 2, with one end of the pressure-stabilizing spring 14 abutting against the upper spring seat 13 and the other end abutting against the lower spring seat 2. A sleeve 15 is provided below the pressure cap 10 and inside the valve body 4. The lower spring seat 2 and the diaphragm element 1 are both located inside the valve body 4. The sleeve 15 surrounds the lower spring seat 2. A first annular stepped surface is provided on the inner wall of the valve body 4. The bottom end of the sleeve 15 presses the edge of the diaphragm element 1 against the first annular stepped surface 16. Specifically, after the pressure cap 10 is tightened, a force is applied to the sleeve 15, and the sleeve 15 is pressed down on the edge of the diaphragm element 1 by force.

[0031] In the preferred embodiment, see Figure 2A valve core assembly is provided in the middle section of the valve body 4. The valve core assembly includes a threaded sleeve 17, in which a first push rod seat 18 movable axially along the threaded sleeve 17 is provided. A first push rod 19 is integrally formed on the first push rod seat 18. After the first push rod 19 passes through the threaded sleeve 17, the end of the first push rod 19 abuts against the boss 9 of the top plate 7. A receiving groove is provided on the bottom surface of the first push rod seat 18, and a return spring 20 is provided in the receiving groove. A support plate 21 is provided below the receiving groove, and one end of the return spring 20 passes through the receiving groove and abuts against the support plate 21. Since the first push rod seat 18 and the first push rod 19 are integrally formed, it is not necessary to assemble the first push rod 19 and the first push rod seat 18 separately, and it is also not necessary to provide a seal between the first push rod 19 and the first push rod seat 18, which simplifies the assembly process and further improves the assembly efficiency. In this embodiment, a second annular stepped surface 22 is provided on the inner side wall of the valve body 4. The body of the threaded sleeve 17 is connected to the inner wall of the valve body 4 by threaded engagement. The bottom surface of the head of the threaded sleeve 17 abuts against the second annular stepped surface 22. A first annular sealing element 23 is provided between the body of the threaded sleeve 17 and the side wall of the valve body 4, which effectively ensures the pressure stabilization effect inside the valve body 4.

[0032] In the preferred embodiment, see Figure 2-4 One side of the film member 1 is partially recessed towards the other side, forming an annular groove on one side and an annular protrusion 24 on the other side. This structure increases the amount of stretching of the film member 1, further ensuring its elasticity.

[0033] In the preferred embodiment, see Figure 2-4 An annular protrusion 24 is formed on the side of the diaphragm 1 facing away from the lower spring seat 2. This structure not only ensures the elasticity of the diaphragm 1 but also does not interfere with the assembly of the diaphragm 1 and the lower spring seat 2. In addition, the edge of the top plate 7 is recessed, and the annular protrusion 24 of the diaphragm 1 is opposite to the recessed edge of the top plate 7 and extends into the recessed space, making full use of the internal space of the valve body 4 and resulting in a more compact structure.

[0034] In the preferred embodiment, see Figure 2 The valve body also includes a gas on / off assembly, which is located in the lower section of the valve body 4. The gas on / off assembly includes a horizontally arranged rotating rod 25, one end of which extends horizontally through the valve body 4 and outwards. Two annular sealing grooves are spaced apart on the side wall of the rotating rod 25, and a sealing ring 26 is fitted into each annular sealing groove. A portion of the sealing ring 26 protrudes from the annular sealing groove and abuts against the wall surface of the valve body 4. The double sealing rings 26 effectively prevent communication between the inside and outside of the valve body 4, preventing fuel leakage and ensuring the stability of the fuel flow inside the valve body 4.

[0035] In this embodiment, see Figure 2The gas on / off assembly also includes a mounting groove on the inner wall of the valve body 4, a support handle 27 in the mounting groove, and a switch rod 28 between the support handle 27 and the other end of the rotating rod 25. The axis of the switch rod 28 is offset from the axis of the rotating rod 25 and the axis of the support handle 27 to form an eccentric state. A gas cylinder connector 29 is provided below the switch rod 28, and a second push rod seat 30 that can move up and down is provided in the gas cylinder connector 29. A second push rod 31 is integrally formed on the second push rod seat 30. A partition 32 is provided in part 9. The outer side wall of the part of the gas tank connector 29 above the partition 32 is provided with external threads for forming a threaded connection with the valve body 4, which facilitates the replacement and maintenance of the gas tank connector 29 and its components. The inner side wall of the part of the gas tank connector 29 below the partition 32 is provided with internal threads for forming a threaded connection with the gas tank containing fuel, which facilitates the replacement of the gas tank. One end of the second push rod seat 30 extends to the outside of the gas tank connector 29 and is opposite to the switch rod 28. The second push rod 31 is located in the gas tank connector 29 and passes through the partition 32. Because the switch rod 28 is eccentrically positioned, during the rotation of the rotating rod 25, the switch rod 28 can press down on the head of the second push rod seat 30 or disengage from the head of the second push rod seat 30. When the head of the second push rod seat 30 is pressed down, the head of the second push rod seat 30 blocks the fuel outlet of the gas cylinder connector 29, thereby achieving the gas cut-off function, and the gas torch will not produce a flame. When disengaged from the head of the second push rod seat 30, the head of the second push rod seat 30 will not block the fuel outlet of the gas cylinder connector 29, thereby achieving the gas passage function, and the gas torch can burn and produce a flame. The second push rod 31 has a hollow structure with an open free end. An air outlet 33 is provided on the side wall of the second push rod 31, connecting to the hollow internal structure. The air outlet 33 connects to the cavity 34 of the gas tank connector 29 located above the partition 32, allowing fuel entering from below the partition 32 of the gas tank connector 29 to enter the hollow structure of the second push rod 31, then through the air outlet 33 into the cavity 34 of the gas tank connector 29 located above the partition 32, and subsequently into the airflow chamber through the fuel outlet of this cavity 34. A spring 35 is provided between the second push rod seat 30 and the partition 32, and within the gas tank connector 29. One end of the spring 35 abuts against the second push rod seat 30, and the other end abuts against the partition 32. The spring 35 is also sleeved on the second push rod 31.

[0036] In this embodiment, the pressure regulating valve of the gas torch, when in operation, rotates the rotating rod 25 to disengage the switch rod 28 from the head of the second push rod seat 30. At this time, under the reset action of the spring 35, the head of the second push rod seat 30 is disengaged from the fuel outlet of the gas cylinder connector 29. Fuel enters from the hollow part of the second push rod 31 and enters the cavity 34 of the gas cylinder connector 29 located above the partition 32 through the air outlet 33. Then, it enters the valve body 4 from the fuel outlet of the cavity 34, and then enters the inner cavity of the threaded sleeve 17 through the through hole on the support plate 21. Since there is a gap between the first push rod seat 18 and the inner cavity wall of the threaded sleeve 17, the fuel can flow through the gap between them. Since the through hole on the head of the first push rod 19 and the threaded sleeve 17 is clearance-fitted, the fuel can continue to flow out of the threaded sleeve 17 through the gap between them, and then enter the air outlet rod 37 through the air outlet hole 36. See also Figure 5 The first push rod 19 is conical, while the through hole on the head of the screw sleeve 17 is cylindrical. When the flow rate needs to be adjusted, the adjusting screw 12 is rotated to apply force to the upper spring seat 13. As the upper spring seat 13 moves up and down, it exerts a downward or loosening force on the stabilizing spring 14, thereby causing the lower spring seat 2 to move up and down. The lower spring seat 2 causes a part of the diaphragm 1 to move up and down, which in turn causes the top plate 7 to move up and down. Finally, the top plate 7 and the return spring 20 work together to make the first push rod 19 move up and down. During the up and down movement of the first push rod 19, due to its conical structure, the gap between its side wall and the wall of the through hole on the head of the screw sleeve 17 can be increased or decreased, thereby realizing the adjustment of the fuel flow rate.

[0037] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0038] In the description of this specification, the references to terms such as "preferred embodiment," "another embodiment," "other embodiment," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0039] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A pressure regulating valve for a gas torch, comprising a diaphragm and a lower spring seat, characterized in that: A buckle is provided at the center of the side of the diaphragm component facing the lower spring seat, and a locking hole is provided at the center of the bottom surface of the lower spring seat. After the buckle on the diaphragm component is engaged with the locking hole on the lower spring seat, the diaphragm component and the lower spring seat are connected as one unit.

2. The pressure regulating valve of the gas torch according to claim 1, characterized in that: The buckle includes a body connected to the diaphragm and a head connected to one end of the body facing the lower spring seat. The diameter of the head is larger than the diameter of the body and also larger than the diameter of the locking hole. An annular locking groove is formed between the head and the diaphragm. After the buckle and the locking hole are assembled, the edge of the locking hole is embedded in the annular locking groove, and the bottom surface of the head of the buckle contacts the bottom surface of the lower spring seat.

3. The pressure regulating valve of the gas torch according to claim 2, characterized in that: The head side wall of the buckle is provided with an annular bevel.

4. The pressure regulating valve of the gas torch according to claim 2, characterized in that: The height of the annular groove is the same as the thickness of the bottom surface of the lower spring seat.

5. The pressure regulating valve of the gas torch according to claim 2, characterized in that: The buckle extends through the diaphragm and forms a positioning protrusion on the side of the diaphragm facing away from the lower spring seat. The pressure regulating valve of the gas torch also includes a top plate, the center of the side of the top plate facing the diaphragm being recessed to the other side to form a positioning groove, and a boss being formed on the other side of the top plate. When the diaphragm and the lower spring seat are connected to form an integral unit and installed in the valve body, the positioning protrusion is inserted into the positioning groove.

6. The pressure regulating valve of the gas torch according to claim 5, characterized in that: A valve core assembly is provided in the middle section of the valve body. The valve core assembly includes a threaded sleeve. A first push rod seat that can move axially along the threaded sleeve is provided in the threaded sleeve. A first push rod is integrally formed on the first push rod seat. After the first push rod passes through the threaded sleeve, the end of the first push rod abuts against the boss of the top plate. A receiving groove is provided on the bottom surface of the first push rod seat. A return spring is provided in the receiving groove. A support plate is provided below the receiving groove. One end of the return spring passes through the receiving groove and abuts against the support plate.

7. The pressure regulating valve of the gas torch according to claim 1, characterized in that: One side of the film is partially recessed towards the other side to form an annular groove on one side of the film and an annular protrusion on the other side.

8. The pressure regulating valve of the gas torch according to claim 7, characterized in that: The annular protrusion is formed on the side of the thin film component opposite to the lower spring seat.

9. The pressure regulating valve of the gas torch according to claim 1, characterized in that: It also includes a pressure cap, which is screwed into the top opening of the valve body and closes the top opening of the valve body; a sleeve is provided below the pressure cap and inside the valve body, the lower spring seat and the diaphragm are both provided inside the valve body, the sleeve surrounds the lower spring seat, a first annular stepped surface is provided on the inner wall of the valve body, and the bottom end of the sleeve presses the edge of the diaphragm onto the first annular stepped surface.

10. The pressure regulating valve of the gas torch according to claim 1, characterized in that: It also includes a gas on / off assembly, which is located in the lower section of the valve body. The gas on / off assembly includes a horizontally arranged rotating rod, one end of which passes through the valve body and extends to the outside of the valve body. The side wall of the rotating rod is provided with two annular sealing grooves at intervals. A sealing ring is fitted in each annular sealing groove, and a portion of the sealing ring protrudes from the annular sealing groove and abuts against the wall surface of the valve body.

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