Shut-off valve for gas engines

Abstract

To provide a cutoff valve for a gas engine capable of opening a valve element with small driving force, not requiring high dimensional accuracy and assembling accuracy in manufacturing and assembling components, and having high productivity.SOLUTION: In a cutoff valve 13 for a gas engine composed of: a first diaphragm 40 operated under a negative pressure; a cutoff rod 43 connected to the first diaphragm 40; a valve element 47 operated by the cutoff rod 43; and a valve seat 48 opened and closed by the valve element 47, a cutoff lever 46 is disposed between the cutoff rod 43 and the valve element 47 in a manner of being rotatably supported at one end portion and pressed by the cutoff rod 43 at the other end portion so as to press the valve element 47 at an intermediate portion by the principle of lever and to open and close the valve seat 48.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to an improvement of a shut-off valve used in a fuel supply device for a gas engine.

Background Art

[0002] Conventionally, as a shut-off valve for a gas engine, a shut-off valve that shuts off the supply of fuel to the gas engine when the gas engine stops is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As shown in FIG. 2 of Patent Document 1, the shut-off valve 17 incorporated in two adjacent block members 31 and 32 is composed of a diaphragm 41 that operates by negative pressure, a rod 43 connected to the diaphragm 41, a valve body 56 operated by the rod , and a valve seat 53 opened and closed by the valve body 56. In particular, one of the block members 31 incorporates the diaphragm 41 and the rod 43 that constitute the shut-off valve 17. Further, the other block member 32 incorporates the valve body 56 and the valve seat 53 that constitute the shut-off valve

[0005] However, according to the shut-off valve for the gas engine, the rod 43 and the valve body 56 face and are arranged to face each other in a central chamber 63 formed between two adjacent block members 31 and 32. Therefore, in order to open and close the valve body 56, it is necessary to press the valve body 56 with only the rod 43. As a result, in order to open the valve body 56, it is necessary to apply a large driving force to the rod 43. Furthermore, in order for the rod 43 alone to accurately open the valve body 56, the axis of the valve body 56 and the axis of the rod 43 must be precisely positioned on the same straight line. This requires high precision in parts and assembly, resulting in time-consuming manufacturing and assembly, and low productivity. In view of the aforementioned problems, the present invention aims to provide a highly productive shut-off valve for gas engines that can open the valve body with a small driving force, and does not require high dimensional accuracy or assembly accuracy in the manufacturing and assembly of the parts. [Means for solving the problem]

[0006] The gas engine shut-off valve according to the present invention, in order to solve the above problems, comprises a diaphragm that operates under negative pressure, a shut-off rod connected to the diaphragm, a valve body that is operated by the shut-off rod, and a valve seat that is opened and closed by the valve body, Between the shut-off rod and the valve body, one end but The other end is rotatably supported. The projection provided thereon is biased and pressed against the tip surface of the blocking rod, and, The aforementioned blocking rod tip surface By being pressed, the valve body is pressed in the middle section by the principle of leverage, Furthermore, the valve body is moved back and forth in the axial direction. The system is configured to include a shut-off lever that opens and closes the valve seat. [Effects of the Invention]

[0007] According to the present invention, the shut-off rod, via the shut-off lever, uses the principle of leverage to press against the valve body and open the valve seat. Therefore, the shut-off rod that presses against the valve body does not require a large driving force. In particular, since the valve body is brought into contact with the middle part of the shut-off lever, the shut-off lever can be shortened, resulting in a compact shut-off valve. Furthermore, since it is only necessary to position the valve body so that it contacts the middle part of the lever member, high precision in parts and assembly is not required, making manufacturing easier and resulting in a highly productive shut-off valve for gas engines.

[0008] In one embodiment of the present invention, a projection that contacts the shut-off rod may be provided at the other end of the shut-off lever. According to this embodiment, the shut-off rod precisely contacts the predetermined position of the shut-off lever, resulting in accurate operating characteristics.

[0009] In another embodiment of the present invention, the intermediate portion of the shut-off lever may be located midway between its one end and the other end. According to this embodiment, based on the principle of leverage, the valve body can be driven with half the driving force. This has the effect of... [Brief explanation of the drawing]

[0010] [Figure 1] This is a system diagram of a gas engine fuel supply system to which the gas engine shut-off valve according to the present invention is applied. [Figure 2] This is a perspective view showing a shut-off valve integrated regulator, which integrates a shut-off valve and a primary regulator for a gas engine according to the present invention. [Figure 3] Figure 2 shows a perspective view of the shut-off valve integrated regulator from a different angle. [Figure 4] Figure 2 is a front view of the shut-off valve integrated regulator shown. [Figure 5] This is a cross-sectional view along line AA in Figure 4. [Figure 6] Figure 5 is an enlarged cross-sectional view of the main part. [Figure 7] Figure 4 is a cross-sectional view along line AA showing the operating state of the shut-off valve integrated regulator. [Figure 8] Figure 7 is an enlarged cross-sectional view of the main part. [Figure 9] Figure 4 is a cross-sectional perspective view along line BB. [Figure 10] Figure 4 is a cross-sectional view along the CC line. [Figure 11] Figure 4 is a cross-sectional view along the DD line. [Figure 12] Figure 11 is an enlarged cross-sectional perspective view of the main part of the primary regulator shown. [Figure 13] Figure 4 is a front view with the decompression chamber exposed. [Figure 14] It is a front view showing the state where the connecting body is removed from FIG. 13. [Figure 15] It is a front view showing the state where the regulator lever is removed from FIG. 14. [Figure 16] It is an overall perspective view of the shut-off lever shown in FIG. 6.

Embodiments for Carrying out the Invention

[0011] Embodiments of the shut-off valve for a gas engine according to the present invention will be described based on FIGS. 1 to 16. FIG. 1 is a system diagram of a gas engine fuel supply device to which the shut-off valve for a gas engine according to the present invention is applied. The gas engine fuel supply device includes, as liquefied gas fuel, for example, a small gas cylinder 10 filled with liquefied butane, which is connected via a cylinder case (not shown), and a manual cock 11 for switching the outflow or shut-off of the liquefied gas fuel from the small gas cylinder 10; a vaporizer 12 for vaporizing the liquefied gas fuel (liquefied butane) using the heat generated in the gas engine 18; a shut-off valve 13 for allowing the gas fuel vaporized by the vaporizer 12 to flow during the operation of the gas engine 18 and shutting it off during the stop of the gas engine 18; a primary regulator 14 assembled so as to have an integral structure with the shut-off valve 13 for reducing the pressure of the gas fuel to a predetermined pressure; a secondary regulator 16 for reducing the pressure of the gas fuel decompressed by the primary regulator 14 to a pressure close to atmospheric pressure; and a mixer 17 for mixing the gas fuel decompressed by the secondary regulator 16 and air to generate an air-fuel mixture. Note that a heater 15 is attached to the shut-off valve 13. Further, the shut-off valve 13 and the primary regulator 14 constitute a shut-off valve integrated regulator 20 assembled in an integral structure.

[0012] The air-fuel mixture produced by the mixer 17 is drawn into the combustion chamber 18b of the gas engine 18 via the intake port 18a, and the combustion gas produced in the combustion chamber 18b is discharged from the exhaust port 18c. The crankcase 18d of the gas engine 18 is connected to the shut-off valve 13. The vaporizer 12 mentioned above is located near the exhaust port 18c.

[0013] Figures 2 through 15 illustrate the shut-off valve integrated regulator 20. The shut-off valve integrated regulator 20 is formed of adjacent first and second block bodies 21 and 22, a first cover 23 that closes the lateral opening of the first block body 21, a second cover 24 that closes the lateral opening of the second block body 22, and a tar storage cup member 25 that closes the opening on the bottom surface of the second block body 22. A central chamber 52, which will be described later, is formed between the joined and integrated first block body 21 and second block body 22.

[0014] A gas fuel inlet 31 is attached to the left side of the first block body 21, and a heater connection part 32 is attached to the left side of the second block body 22.

[0015] Furthermore, a negative pressure generation connection section 33 connected to the crank chamber 18d is connected to the right side of the first block body 21, and a gas fuel outlet 34 and an outside air introduction connection section 35 are connected to the right side of the second block body 22. The negative pressure generation connection section 33 is equipped with an on / off valve (not shown) to appropriately introduce outside air into the negative pressure chamber 51. The gas fuel outlet 34 is for sending high-pressure gas fuel to the secondary regulator 16. The outside air introduction connection section 35 is for adjusting the pressure in the negative pressure chamber 51, which will be described later, to the same level as atmospheric pressure after the gas engine 18 has been stopped.

[0016] As shown in Figures 5 and 6, the internal space located between the first block body 21 and the first cover 23 is partitioned by the first diaphragm 40 into a first atmospheric chamber 50 and a negative pressure chamber 51, with the first atmospheric chamber 50 communicating with the outside air. The first diaphragm 40 is supported on its inner surface by a support plate 41 and is biased outward via a coil spring 42 that presses against the inner surface of the support plate 41.

[0017] The shut-off rod 43 is assembled to pass through the first block body 21 and be slidably mounted. One end of the shut-off rod 43 is connected to the center of the first diaphragm 40 and support plate 41 via a fastener 44, and the other end protrudes into the central chamber 52 via the second diaphragm 45. A shut-off lever 46 is positioned in the central chamber 52 so as to be rotatable with a pivot shaft 52a as the pivot point. The tip of the valve body 47 protrudes from the valve seat 48 into the central chamber 52 so as to abut against the middle part of the shut-off lever 46. The tip of the shut-off lever 46 is biased towards the negative pressure chamber 51 via a coil spring 49a. The valve body 47 is also biased towards the central chamber 52 via a coil spring 49b. As shown in Figure 16, a projection 46a (Figure 16) is formed by protrusion machining on the other end of the shut-off lever 46 to ensure accurate contact with the shut-off rod 43.

[0018] Therefore, as shown in Figures 7 and 8, when the first diaphragm 40 bends toward the central chamber 52 against the spring force of the coil spring 42, the shut-off rod 43 slides against the spring force of the coil spring 49a, pushing the tip of the shut-off lever 46. As a result, the shut-off lever 46 presses and moves the valve body 47 using the principle of leverage. This opens the vent hole in the valve seat 48, connecting the central chamber 52 and the flow passage 47a, allowing gaseous fuel to flow into the central chamber 52 and then out toward the depressurization chamber 54, which will be described later. Furthermore, when the valve body 47 is driven by the shut-off rod 43 via the shut-off lever 46, the valve body 47 is driven using the principle of leverage. As a result, the shut-off rod 43 can drive the valve body 47 with less driving force than conventional rods, and can reliably drive the valve body 47 even if there is a large variation in the spring force of the coil spring 49b that biases the valve body 47. Consequently, there is no need to select a coil spring 49b with small variations in spring force. In short, when selecting a coil spring 49b to bias the valve body 47, there is the advantage that even a coil spring with a large variation in spring force can be used as the coil spring 49b.

[0019] As shown in Figures 11 and 12, the internal space located between the second block body 22 and the second cover 24 is divided into a second atmospheric chamber 53 and a depressurization chamber 54 by the third diaphragm 60. The third diaphragm 60 is supported on its outer surface by a support plate 61 and biased toward the depressurization chamber 54 by the spring force of a coil spring 62 that presses against the support plate 61. A connecting body 63 is assembled to the center of the third diaphragm 60 and the support plate 61. The tip 64a of the regulator lever 64 is inserted through the connecting hole 63a (Figure 12) of the connecting body 63. Furthermore, a stopper 54a of the second block body 22 is provided protruding directly below the center of the connecting body 63. The regulator lever 64 is rotatably supported with a support shaft 65 as the pivot point. A pressure regulating valve 66 that opens and closes the gas inlet 68 of the nozzle 67 is assembled to the other end of the regulator lever 64. The nozzle 67 communicates with the central chamber 52 via a flow passage 67a. Furthermore, the connecting body 63 and the stopper 54a are positioned on the same straight line as the center line passing through the center of the third diaphragm 60. In addition, the second atmospheric chamber 53 is in communication with the outside air.

[0020] As shown in Figure 15, the high-pressure gas fuel sent from the central chamber 52 to the depressurization chamber 54 via the gas inlet 68 diffuses and is depressurized before being discharged from the gas outlet 69 to the secondary regulator 16 via the gas fuel outlet 34.

[0021] The operation of the shut-off valve 13 and primary regulator 14 described above will now be explained. When the gas engine 18 starts and air is drawn into the negative pressure chamber 51 from the negative pressure generating connection 33 which communicates with the crankcase 18d, causing the pressure to drop, the first diaphragm 40 and support plate 41 move toward the negative pressure chamber 51 against the spring force of the coil spring 42, and the shut-off rod 43 slides toward the central chamber 52.

[0022] Therefore, the tip of the shut-off rod 43 presses against the other end of the shut-off lever 46 via the second diaphragm 45, against the spring force of the coil spring 49a. As a result, the shut-off lever 46 pushes the valve body 47 against the spring force of the coil spring 49b via the principle of leverage. Then, as the valve body 47 separates from the valve seat 48, the fuel passage is opened and the shut-off valve 13 opens.

[0023] As a result, as shown in Figure 9, the gas fuel flowing in from the gas fuel inlet 31 flows into the central chamber 52 via the flow passage 47a and flows out towards the depressurization chamber 54 of the primary regulator 14 via the flow passage 67a (Figure 10).

[0024] When the pressure in the depressurization chamber 54 is low, the third diaphragm 60 and support plate 61 are pushed into the depressurization chamber 54 by atmospheric pressure and the spring force of the coil spring 62. As a result, the connecting body 63 moves towards the depressurization chamber 54, pushing down the tip 64a of the regulator lever 64. Consequently, the regulator lever 64 rotates around the support shaft 65 as a pivot point, the pressure regulating valve 66 moves away from the gas inlet 68, which is the opening of the nozzle 67, and gas fuel flows into the depressurization chamber 54 from the gas inlet 68, increasing the pressure.

[0025] As the pressure in the decompression chamber 54 increases, the third diaphragm 60 and support plate 61 are pushed outward against atmospheric pressure and the spring force of the coil spring 62, and the connecting body 63 also moves toward the second atmospheric chamber 53. As a result, the regulator lever 64 rotates around the pivot shaft 65, and the pressure regulating valve 66 closes the gas inlet 68, which is the opening of the nozzle 67, restricting the inflow of gas fuel into the decompression chamber 54. Thereafter, the supply of gas fuel is adjusted according to the pressure, and the gas fuel is reduced to a predetermined pressure. Furthermore, if the pressure in the depressurization chamber 54 is too low, the lower end of the connecting body 63 will come into contact with the stopper 54a. This is to prevent damage to the third diaphragm 60. It is also to regulate the excessive flow of gas fuel into the depressurization chamber 54 and to adjust the supply of gas fuel. In particular, according to this embodiment, the connecting body 63 and the stopper 54a are arranged on the same straight line as the center line passing through the center of the third diaphragm 60. Therefore, there is an advantage that the displacement of the third diaphragm 60 can be precisely controlled via the stopper 54a.

[0026] The operation of the aforementioned fuel supply system will now be explained. When the manual cock 11 shown in Figure 1 is opened, gas fuel flows from the small gas cylinder 10 through the vaporizer 12 to the shut-off valve 13 of the shut-off valve integrated regulator 20. Then, when the recoil starter (not shown) is pulled to drive the crank in the crank chamber 18d of the gas engine 18, air is drawn in from the negative pressure chamber 51 via the negative pressure generation connection part 33, causing the pressure to drop. As a result, the pressure difference between the first atmospheric chamber 50 and the negative pressure chamber 51 causes the first diaphragm 40 and the support plate 41 to be displaced toward the negative pressure chamber 51. Consequently, the shut-off rod 43 moves toward the central chamber 52 within the first block body 21, against the spring force of the coil spring 42, and presses the tip of the shut-off lever 46. The shut-off lever 46 rotates around the pivot shaft 52a, against the spring forces of the coil springs 49a and 49b, and pushes in the valve body 47 based on the principle of leverage. The valve body 47 is pushed out from the valve seat 48, opening the vent hole of the valve seat 48. Therefore, after the gaseous fuel flows from the flow passage 47a into the central chamber 52, it flows out towards the nozzle 67 via the flow passage 67a (Figure 10).

[0027] When the pressure in the depressurization chamber 54 is low, the atmospheric pressure and the spring force of the coil spring 62 displace the third diaphragm 60 and support plate 61 toward the depressurization chamber 54, pushing the connecting body 63 inward. As a result, the tip 64a of the regulator lever 64, which is inserted through the connecting hole 63a of the connecting body 63, is pushed down, causing the regulator lever 64 to rotate around the pivot shaft 65. This causes the pressure regulating valve 66 to separate from the nozzle 67. As a result, the gas fuel flowing from the central chamber 52 flows into the depressurization chamber 54 from the gas inlet 68 of the nozzle 67 and diffuses, reducing the pressure. Then, it flows out from the gas outlet 69 through a flow passage (not shown) to the secondary regulator 16 via the gas fuel outlet 34.

[0028] The gaseous fuel, reduced to atmospheric pressure by the secondary regulator 16, is mixed with air in the mixer 17 to produce a fuel-air mixture. This mixture is supplied to the combustion chamber 18b of the gas engine 18 via the intake port 18a, and the high-temperature combustion gases produced by combustion are exhausted through the exhaust port 18c. The high temperature of the exhaust port 18c heats the vaporizer 12, promoting the vaporization of the liquefied gaseous fuel.

[0029] Furthermore, the shut-off valve 13, which is equipped with a shut-off lever 46 for utilizing the lever principle, does not necessarily need to be combined with the primary regulator 14, and of course, the shut-off valve 13 can be used on its own. [Industrial applicability]

[0030] The shut-off valve according to the present invention may be applied not only to the fuel supply device of the aforementioned gas engine, but also, of course, to a gas engine for LP gas, for example. [Explanation of Symbols]

[0031] 10 small gas cylinders 11 Manual Cock 12 vaporizers 13 Shut-off valve 14. Primary Regulator 15 Heater 16. Secondary regulator 17 Mixer 18 Gas engine 20. Regulator with integrated shut-off valve 21. Block 1 22 Block 2 23 Cover 1 24 Second Cover 25 Tar storage cup component 31 Gas fuel inlet 32 Heater connection section 33. Negative pressure generation connection section 34 Gas fuel outlet 35 Connection part for outside air intake 40. First diaphragm 41 Support plate 42 Coil springs 43 Blocking rod 44 Fasteners 45. Second diaphragm 46. ​​Circuit breaker lever 46a protrusion 47 Valve body 47a Distribution path 48 valve seats 49a Coil spring 49b Coil spring 50 First atmospheric chamber 51 Negative pressure chamber 52 Central room 52a spindle 53 Second atmospheric chamber 54 Decompression Chamber 54a Stopper 60. Third diaphragm 61 Support plate 62 Coil springs 63 Concatenation 63a Connection hole 64 Regulator Lever 65 Spindle 66 Pressure Regulating Valve 67 nozzles 67a Distribution path 68 Gas Inlet 69 Gas outlet

Claims

[Claim 1] A shut-off valve for a gas engine comprising a diaphragm that operates under negative pressure, a shut-off rod connected to the diaphragm, a valve body actuated by the shut-off rod, and a valve seat that is opened and closed by the valve body, Between the shut-off rod and the valve body, One end is rotatably supported, The projection provided at the other end is biased and pressed against the tip surface of the blocking rod, and is also pressed against by the tip surface of the blocking rod, A shut-off valve for a gas engine, characterized by having a shut-off lever that presses the valve body in the middle using the principle of leverage and reciprocates the valve body in the axial direction to open and close the valve seat.

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