Double stroke switch of LNG pneumatic liquid filling gun

Abstract

The utility model relates to the technical field of pneumatic liquid adding gun, especially a LNG pneumatic liquid adding gun double-stroke switch, which comprises a pneumatic mechanism, a gas guide mechanism is installed on the side of the pneumatic mechanism, an adjusting mechanism is installed inside the gas guide mechanism, the pneumatic mechanism comprises a main body shell, first, second and third through holes are formed in the side wall of the main body shell, a first movable piston is movably connected inside the main body shell, a second movable piston is movably connected inside the main body shell, the gas guide mechanism comprises a gas guide shell, first, second and third connecting holes are formed in the back of the gas guide shell, a first exhaust hole and a second exhaust hole are formed in the right side wall of the gas guide shell, a third exhaust hole and an air inlet hole are formed in the left side wall of the gas guide shell, and the adjusting mechanism comprises an adjusting rod. The utility model provides a LNG pneumatic liquid adding gun double-stroke switch, which can be lifted by a clamping jaw to lock the gun for protection before liquid adding, and the clamping jaw can be unlocked only when the liquid adding gun is withdrawn after liquid adding.

Description

Technical Field

[0001] This utility model relates to the field of pneumatic liquid dispensing guns, and in particular to a dual-stroke switch for an LNG pneumatic liquid dispensing gun. Background Technology

[0002] An LNG pneumatic filling nozzle is a device used to fill LNG (liquefied natural gas) cylinders. It employs pneumatic control, typically using instrument air as the control gas source. When the button on the controller is pressed, airflow enters the upper or lower chamber of the housing through the vent hole of the control plug, pushing the piston disc to open the valve. Simultaneously, the locking jaws rotate under the influence of the airflow and lock the filling port, initiating LNG filling. After filling is complete, pressing the button again changes the airflow direction, the piston disc returns to its original position, closing the valve, and the locking jaws release, allowing the filling nozzle to be removed.

[0003] Most existing LNG pneumatic filling guns lack a gun locking protection function when the gun is pulled out to release pressure. If the valve core is not completely closed, the jet pressure generated by the instantaneous vaporization of residual LNG can easily injure the operator. At the same time, its slit-flow liquid inlet design also has the problems of low filling efficiency and long time consumption. Utility Model Content

[0004] In view of this, the present invention provides a dual-stroke switch for an LNG pneumatic dispensing gun. The main technical problem to be solved is to provide a dual-stroke switch for an LNG pneumatic dispensing gun that can lock the gun by lifting the claw before dispensing, and unlock the claw only when the dispensing gun is withdrawn after dispensing is completed.

[0005] To achieve the above objectives, this utility model adopts the following technical solution: a dual-stroke switch for an LNG pneumatic dispensing gun, comprising a pneumatic mechanism, a gas guiding mechanism mounted on the side of the pneumatic mechanism, an adjusting mechanism mounted inside the gas guiding mechanism, and a gas storage nozzle mounted at the bottom of the pneumatic mechanism. The pneumatic mechanism includes a main shell, with a first through hole, a second through hole, and a third through hole formed on the side wall of the main shell. A first movable piston is movably connected inside the main shell, and a second movable piston is movably connected inside the main shell. A connecting rod assembly is mounted at the bottom of the second movable piston. The gas guiding mechanism includes a gas guiding shell, and the gas guiding shell... The air guide shell is fixedly installed on the side wall of the main body shell. The back of the air guide shell is provided with a first connecting hole, a second connecting hole and a third connecting hole. The position of the first connecting hole corresponds to the position of the first through hole, the position of the second connecting hole corresponds to the position of the second through hole, and the position of the third connecting hole corresponds to the position of the third through hole. The right side wall of the air guide shell is provided with a first exhaust hole and a second exhaust hole, and the left side wall of the air guide shell is provided with a third exhaust hole and an air inlet hole. The adjustment mechanism includes an adjustment rod, which is installed inside the air guide shell. The outer surface of the adjustment rod is fixedly connected with a first fixing ring, a second fixing ring, a third fixing ring and a fourth fixing ring.

[0006] By adopting the above technical solution, during use, the adjusting rod is initially at its lowest position, at which point the air inlet is connected to the third connecting hole and the third through hole. At this time, the first moving piston and the second moving piston move upward together, thereby controlling the connecting rod assembly to move upward. Then, the adjusting rod is controlled to move upward to the first stroke point, at which point the first connecting hole, the first through hole, and the air inlet are connected, and compressed air enters above the first moving piston. At this time, the first moving piston and the second moving piston move downward together, thereby controlling the connecting rod assembly to move downward a section. The adjusting rod continues to be controlled to move upward to the second stroke point, at which point the second connecting hole and the second through hole are connected to the air inlet. At this time, the first moving piston moves upward, and the second moving piston moves downward. At this time, the connecting rod assembly moves downward two sections, allowing the bottom of the connecting rod assembly to be inserted into the nozzle of the gas storage mechanism, thereby performing the liquid filling operation.

[0007] As a further description of the above technical solution:

[0008] A connecting rod is fixedly connected to the lower surface of the main body shell, and a fixing sleeve is fixedly connected to the bottom of the connecting rod. A clamping claw is movably connected inside the fixing sleeve, and there are multiple clamping claws.

[0009] By adopting the above technical solution, when in use, the fixing sleeve is sleeved on the outside of the gas storage mechanism bottle mouth to achieve the purpose of positioning. The clamps on the fixing sleeve can rotate inside the fixing sleeve. When the clamps are in a vertical state, they will clamp on the flange on the gas storage mechanism bottle mouth, thereby fixing the gas storage mechanism bottle mouth.

[0010] As a further description of the above technical solution:

[0011] A movable sleeve is fitted onto the outer surface of the fixed sleeve. A screw hole is formed on the surface of the movable sleeve. A slot is formed on the surface of the connecting rod assembly. A screw is threaded into the screw hole, and the end of the screw extends into the slot.

[0012] By adopting the above technical solution, the movable sleeve is installed on the connecting rod assembly by screws and moves up and down together with the connecting rod assembly. When the connecting rod assembly moves down, the movable sleeve also moves down together. When the movable sleeve moves down, it will squeeze the clamp inward, so that the clamp is in a vertical state, thereby clamping on the flange of the gas storage mechanism bottle nozzle.

[0013] As a further description of the above technical solution:

[0014] A fixed column is fixedly connected to the top of the air guide shell. A stop groove is opened on the outer surface of the fixed column. A stop block is fixedly connected to the outer surface of the adjusting rod. The stop block is installed inside the stop groove.

[0015] By adopting the above technical solution, the stop block can move within the stop groove, thereby assisting the adjustment rod in moving. The stop groove allows the adjustment rod to be adjusted to three gears and move in two strokes more conveniently.

[0016] As a further description of the above technical solution:

[0017] The second through hole is located below the first through hole, and the third through hole is located below the second through hole.

[0018] By adopting the above technical solution, it is convenient to control the movement of the first and second moving pistons after compressed air enters the main body shell.

[0019] As a further description of the above technical solution:

[0020] The first movable piston is located between the first through hole and the second through hole, and the second movable piston is located between the second through hole and the third through hole.

[0021] By adopting the above technical solution, compressed air can enter the main body shell and control the movement of the first and second moving pistons.

[0022] As a further description of the above technical solution:

[0023] The second exhaust port is located below the first exhaust port, and the air inlet is located below the third exhaust port.

[0024] By adopting the above technical solution, compressed air can be easily discharged.

[0025] As a further description of the above technical solution:

[0026] The second fixing ring is located below the first fixing ring, the third fixing ring is located below the second fixing ring, and the fourth fixing ring is located below the third fixing ring.

[0027] By adopting the above technical solution, rubber rings for sealing are provided on the first fixed ring, the second fixed ring, the third fixed ring, and the fourth fixed ring. By adjusting the position of the first fixed ring, the second fixed ring, the third fixed ring, and the fourth fixed ring on the adjusting rod, the communication relationship between the first through hole, the second through hole, the third through hole and the air inlet can be changed, which facilitates the control of the movement of the first moving piston and the second moving piston.

[0028] By employing the above technical solution, the dual-stroke switch for an LNG pneumatic filling gun of this utility model has at least the following beneficial effects:

[0029] 1. Compared with existing technologies, this dual-stroke switch for LNG pneumatic dispensing gun features a design where, during dispensing, the adjusting rod first moves downwards a short distance to lock the nozzle in advance, then moves downwards a second distance, allowing the connector at the bottom of the linkage assembly to insert into the gas cylinder or other liquid storage mechanism before dispensing. When removing the nozzle, the adjusting rod first moves upwards a short distance, pulling the connector out of the gas cylinder or other liquid storage mechanism, then moves upwards a second distance to unlock the nozzle and complete the removal process. This design ensures that if the valve core is not completely closed during dispensing, the pre-locked nozzle prevents the jet pressure generated by the instantaneous vaporization of residual LNG from directly harming the operator, greatly improving operational safety. This dual-stroke switch for LNG pneumatic dispensing gun exhibits excellent stability and reliability, providing strong support for the safe and efficient operation of LNG pneumatic dispensing guns. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure proposed in this utility model;

[0031] Figure 2 This is a first-view sectional view of the internal structure proposed in this utility model;

[0032] Figure 3 The present utility model proposes Figure 2 Enlarged view of the structure at point A in the middle;

[0033] Figure 4 This is a second-view sectional view of the internal structure proposed in this utility model;

[0034] Figure 5 The present utility model proposes Figure 4 Enlarged view of the structure at point B in the middle;

[0035] Figure 6 This is a front view of the air guiding mechanism proposed in this utility model.

[0036] Figure 7 This is a schematic diagram of the back structure of the air guiding mechanism proposed in this utility model;

[0037] Figure 8 This is a schematic diagram of the adjustment mechanism proposed in this utility model.

[0038] Legend:

[0039] 1. Pneumatic mechanism; 101. Main body shell; 102. First through hole; 103. Second through hole; 104. Third through hole; 105. Connecting rod; 106. Moving sleeve; 107. First moving piston; 108. Second moving piston; 109. Connecting rod assembly; 110. Gripper; 111. Screw hole; 112. Slot; 113. Fixed sleeve; 2. Air guiding mechanism; 201. Air guiding shell; 202. Fixed column; 203. Gear slot; 204. First connecting hole; 205. Second connecting hole; 206. Third connecting hole; 207. First exhaust hole; 208. Second exhaust hole; 209. Third exhaust hole; 210. Air inlet; 3. Adjustment mechanism; 301. Adjustment rod; 302. Stop block; 303. First fixing ring; 304. Second fixing ring; 305. Third fixing ring; 306. Fourth fixing ring; 4. Gas storage mechanism nozzle. Detailed Implementation

[0040] Reference Figure 1-8This utility model provides a dual-stroke switch for an LNG pneumatic filling gun: It includes a pneumatic mechanism 1, a gas guiding mechanism 2 mounted on the side of the pneumatic mechanism 1, an adjusting mechanism 3 installed inside the gas guiding mechanism 2, and a gas storage mechanism nozzle 4 mounted at the bottom of the pneumatic mechanism 1. The pneumatic mechanism 1 includes a main body shell 101. The side wall of the main body shell 101 has a first through hole 102, a second through hole 103, and a third through hole 104. The second through hole 103 is located below the first through hole 102, and the third through hole 104 is located below the second through hole 103, facilitating the entry of compressed air into the main body shell 101 to control the movement of the first moving piston 107 and the second moving piston 108. The main body shell 101 is internally connected to the first moving piston... The first moving piston 107 is located between the first through hole 102 and the second through hole 103, and the second moving piston 108 is located between the second through hole 103 and the third through hole 104. This allows compressed air to enter the main body shell 101 and control the movement of the first moving piston 107 and the second moving piston 108. A connecting rod assembly 109 is installed at the bottom of the second moving piston 108. The connecting rod assembly 109 includes a connecting rod and a gas cylinder connector for filling. The gas cylinder connector has an air inlet interface connected to the gas storage mechanism, facilitating the filling of gas into the gas storage mechanism. The gas guiding mechanism 2 includes a gas guiding shell 201, which has an internal opening. The system has an inner cavity, and the air guide shell 201 is fixedly installed on the side wall of the main shell 101. The back of the air guide shell 201 has a first connecting hole 204, a second connecting hole 205, and a third connecting hole 206. The position of the first connecting hole 204 corresponds to the position of the first through hole 102, the position of the second connecting hole 205 corresponds to the position of the second through hole 103, and the position of the third connecting hole 206 corresponds to the position of the third through hole 104. The right side wall of the air guide shell 201 has a first exhaust hole 207 and a second exhaust hole 208, and the left side wall of the air guide shell 201 has a third exhaust hole 209 and an air inlet 210. The second exhaust hole 208 is located below the first exhaust hole 207, and the air inlet 210 is located below the third exhaust hole 209. Below the exhaust port 209, a channel for compressed air flow is provided between the air inlet port 210 and the third exhaust port 209. The top of the channel has a hole communicating with the inner cavity of the air guide housing 201. The air inlet port 210 is connected to a compressed air inlet pipe for easy compressed air discharge. The adjusting mechanism 3 includes an adjusting rod 301, which is installed inside the air guide housing 201. A first fixing ring 303, a second fixing ring 304, a third fixing ring 305, and a fourth fixing ring 306 are fixedly connected to the outer surface of the adjusting rod 301. The second fixing ring 304 is located below the first fixing ring 303, the third fixing ring 305 is located below the second fixing ring 304, and the fourth fixing ring 306 is located below the third fixing ring 305.Each of the first fixing ring 303, second fixing ring 304, third fixing ring 305, and fourth fixing ring 306 is equipped with a rubber ring for sealing. Adjusting the position of the first fixing ring 303, second fixing ring 304, third fixing ring 305, and fourth fixing ring 306 on the adjusting rod 301 can change the communication relationship between the first through hole 102, second through hole 103, third through hole 104 and air inlet 210, facilitating the control of the movement of the first moving piston 107 and the second moving piston 108. In use, the adjusting rod 301 is initially at its lowest position, at which time the air inlet 210 is connected to the third connecting hole 206 and the third through hole 104 (the air inlet 210 is located between the fourth fixing ring 306 and the third fixing ring 305, at which time the first fixing ring 303...). Between the hole at the top of the channel and the inner cavity of the air guide housing 201, and the first connecting hole 204, compressed air can only enter the inner cavity of the air guide housing 201 through the air inlet 210, and then enter the main housing 101 through the third connecting hole 206 and the third through hole 104. At this time, the first moving piston 107 and the second moving piston 108 move upward together, thereby controlling the connecting rod assembly 109 to move upward, and then controlling the adjusting rod 301 to move upward to reach the first stroke point. At this time, the first connecting hole 204, the first through hole 102 and the air inlet 210 are connected (the air inlet 210 is located between the fourth fixed ring 306 and the third fixed ring 305. As the adjusting rod 301 moves upward, the fourth fixed ring 306 moves up to the third connecting hole 204). Between the intake port 210 and the third connecting hole 206, compressed air cannot enter the third connecting hole 206 from the intake port 210. The third fixing ring 305 is located below the second connecting hole 205, and compressed air cannot enter the second connecting hole 205 from the intake port 210. The hole connecting the top of the channel to the inner cavity of the air guide shell 201 is no longer blocked by the first fixing ring 303 between the first connecting hole 204 and the first connecting hole 205. Compressed air enters the second connecting hole 205 and the second through hole 103 through the channel between the intake port 210 and the third exhaust port 209. The compressed air enters above the first moving piston 107. At this time, the first moving piston 107 and the second moving piston 108 move downward together, thereby controlling the connecting rod assembly 109 to move downward a certain distance, and continuing to control the first moving piston 107. When the adjusting rod 301 moves upward to the second stroke point, the second connecting hole 205, the second through hole 103, and the air inlet 210 are connected (the air inlet 210 is located between the fourth fixing ring 306 and the third fixing ring 305). Since the adjusting rod 301 moves upward again, the fourth fixing ring 306 remains between the third connecting hole 206 and the air inlet 210, preventing compressed air from entering the third connecting hole 206 from the air inlet 210. The second fixing ring 304 moves upward and enters the space between the hole and the first connecting hole 204, preventing compressed air from entering the first connecting hole 204 from the air inlet 210. The third fixing ring 305 moves upward, placing both the second connecting hole 205 and the air inlet 210 between the fourth fixing ring 306 and the third fixing ring 305.At this time, compressed air will pass through the second connecting hole 205 and the second through hole 103 into the main body shell 101. The first moving piston 107 moves upward, and the second moving piston 108 moves downward. The connecting rod assembly 109 then moves downward a short distance, allowing its bottom to be inserted into the gas cylinder nozzle 4 for liquid filling. In actual use, when filling, the adjusting rod 301 first moves downward a short distance to lock the nozzle in advance. Then, the adjusting rod 301 moves downward a second distance, allowing the interface at the bottom of the connecting rod assembly 109 to be inserted into the gas cylinder or other liquid storage mechanism before liquid filling begins. When removing the nozzle, the adjusting rod 301 first moves upward a short distance, pulling the interface at the bottom of the connecting rod assembly 109 out of the gas cylinder or other liquid storage mechanism. Then, the adjusting rod 301 moves upward a second distance to unlock the nozzle and complete the removal process.

[0041] A connecting rod 105 is fixedly connected to the lower surface of the main body shell 101. A fixing sleeve 113 is fixedly connected to the bottom of the connecting rod 105. A clamping jaw 110 is movably connected inside the fixing sleeve 113. Multiple clamping jaws 110 are used. In use, the fixing sleeve 113 is fitted over the gas storage mechanism nozzle 4 for positioning. The clamping jaws 110 on the fixing sleeve 113 can rotate within the fixing sleeve 113. When the clamping jaws 110 are in a vertical position, they clamp onto the flange on the gas storage mechanism nozzle 4, thereby fixing the gas storage mechanism nozzle 4. A movable sleeve 106 is fitted onto the outer surface of the fixing sleeve 113. Screw holes 111 are opened on the surface of the movable sleeve 106. The connecting rod assembly 10... The surface of 9 has a slot 112, and the screw hole 111 is internally threaded to connect a screw. The end of the screw extends into the slot 112. The movable sleeve 106 is installed on the connecting rod assembly 109 by the screw and moves up and down with the connecting rod assembly 109. When the connecting rod assembly 109 moves down, the movable sleeve 106 also moves down. When the movable sleeve 106 moves down, it will press the clamp 110 inward, so that the clamp 110 is in a vertical state, thereby clamping on the flange of the gas storage mechanism bottle mouth 4. After moving down a certain distance, the clamp 110 will be clamped on the flange of the gas storage mechanism bottle mouth 4. After moving down a certain distance, the clamp 110 will still be clamped on the flange of the gas storage mechanism bottle mouth 4.

[0042] A fixed post 202 is fixedly connected to the top of the air guide shell 201. A stop groove 203 is opened on the outer surface of the fixed post 202. A stop block 302 is fixedly connected to the outer surface of the adjusting rod 301. The stop block 302 is installed inside the stop groove 203 and can move within the stop groove 203, thereby assisting the adjusting rod 301 to move. This forms the starting point, first stroke point, and second stroke point of the adjusting rod 301. The stop groove 203 allows the adjusting rod 301 to be adjusted in three gears and move in two strokes more conveniently.

[0043] Working principle: When liquid addition is required, first, the fixing sleeve 113 is placed over the nozzle 4 of the gas storage mechanism, so that the gripper 110 is in a rotatable state. In the initial state, the adjusting rod 301 is at its lowest position, and the air inlet 210 is connected to the third connecting hole 206 and the third through hole 104. Compressed air enters the inner cavity of the air guide shell 201 through the air inlet 210, and then passes through the third connecting hole 206 and the third through hole 104 into the main shell 101, pushing the first moving piston 107 and the second moving piston 108 to move upward together, thereby driving the connecting rod assembly 109 to move upward.

[0044] Next, the control lever 301 is moved upward to the first stroke point. At this time, the air inlet 210 is connected to the first connecting hole 204 and the first through hole 102. Compressed air passes through the channel between the air inlet 210 and the third exhaust hole 209, and then through the second connecting hole 205 and the second through hole 103 (during this process, the position of each fixed ring changes due to the upward movement of the control lever 301, and the compressed air flow path changes), and enters above the first moving piston 107, causing the first moving piston 107 and the second moving piston 108 to move downward together, driving the connecting rod assembly 109 to move downward a certain distance.

[0045] Continue to control the adjusting rod 301 to move upward to the second stroke point. At this time, the air inlet 210 is connected to the second connecting hole 205 and the second through hole 103. Compressed air passes through the second connecting hole 205 and the second through hole 103 and enters the main body shell 101. The first moving piston 107 moves upward and the second moving piston 108 moves downward. The connecting rod assembly 109 continues to move downward a distance until the bottom of the connecting rod assembly 109 is inserted into the gas storage mechanism nozzle 4.

[0046] As the connecting rod assembly 109 moves downward, the movable sleeve 106 moves downward along with it. When it moves downward a short distance, the movable sleeve 106 presses the gripper 110 inward, causing the gripper 110 to be in a vertical position and clamp onto the flange of the gas storage mechanism nozzle 4, thus fixing the nozzle 4 in place. When it moves downward a second distance, the gripper 110 remains in a clamping position, ensuring the stability of the gas storage mechanism nozzle 4 during liquid addition, thereby successfully completing the liquid addition operation. After liquid addition is completed, the control adjustment rod 301 moves downward, and all components move in the opposite direction, returning to their initial state for future use.

[0047] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A dual-stroke switch for an LNG pneumatic dispensing gun, comprising a pneumatic mechanism (1), characterized in that: A gas guiding mechanism (2) is installed on the side of the pneumatic mechanism (1), and an adjusting mechanism (3) is installed inside the gas guiding mechanism (2). A gas storage mechanism nozzle (4) is installed at the bottom of the pneumatic mechanism (1). The pneumatic mechanism (1) includes a main shell (101). A first through hole (102), a second through hole (103), and a third through hole (104) are provided on the side wall of the main shell (101). A first moving piston (107) is movably connected inside the main shell (101). A second moving piston (108) is movably connected inside the main shell (101). A connecting rod assembly (109) is installed at the bottom of the second moving piston (108). The gas guiding mechanism (2) includes a gas guiding shell (201). The gas guiding shell (201) is fixedly installed on the side wall of the main shell (101). A first connecting hole (20) is provided on the back of the gas guiding shell (201). 4) The second connecting hole (205) and the third connecting hole (206) are provided. The position of the first connecting hole (204) corresponds to the position of the first through hole (102). The position of the second connecting hole (205) corresponds to the position of the second through hole (103). The position of the third connecting hole (206) corresponds to the position of the third through hole (104). The right side wall of the air guide shell (201) is provided with a first exhaust hole (207) and a second exhaust hole (208). The left side wall of the air guide shell (201) is provided with a third exhaust hole (209) and an air inlet (210). The adjustment mechanism (3) includes an adjustment rod (301). The adjustment rod (301) is installed inside the air guide shell (201). The outer surface of the adjustment rod (301) is fixedly connected with a first fixing ring (303), a second fixing ring (304), a third fixing ring (305) and a fourth fixing ring (306).

2. The dual-stroke switch for an LNG pneumatic dispensing gun according to claim 1, characterized in that: A connecting rod (105) is fixedly connected to the lower surface of the main body shell (101), and a fixing sleeve (113) is fixedly connected to the bottom of the connecting rod (105). A clamp (110) is movably connected inside the fixing sleeve (113), and there are multiple clamps (110).

3. The dual-stroke switch for an LNG pneumatic dispensing gun according to claim 2, characterized in that: The outer surface of the fixed sleeve (113) is fitted with a movable sleeve (106), the surface of the movable sleeve (106) is provided with a screw hole (111), the surface of the connecting rod assembly (109) is provided with a groove (112), the screw hole (111) is internally threaded with a screw, and the end of the screw extends into the groove (112).

4. The dual-stroke switch for an LNG pneumatic dispensing gun according to claim 1, characterized in that: A fixed post (202) is fixedly connected to the top of the air guide shell (201). A stop groove (203) is opened on the outer surface of the fixed post (202). A stop block (302) is fixedly connected to the outer surface of the adjusting rod (301). The stop block (302) is installed inside the stop groove (203).

5. The dual-stroke switch for an LNG pneumatic dispensing gun according to claim 1, characterized in that: The second through hole (103) is located below the first through hole (102), and the third through hole (104) is located below the second through hole (103).

6. The dual-stroke switch for an LNG pneumatic dispensing gun according to claim 1, characterized in that: The first movable piston (107) is located between the first through hole (102) and the second through hole (103), and the second movable piston (108) is located between the second through hole (103) and the third through hole (104).

7. The dual-stroke switch for an LNG pneumatic dispensing gun according to claim 1, characterized in that: The second exhaust port (208) is located below the first exhaust port (207), and the air inlet port (210) is located below the third exhaust port (209).

8. The dual-stroke switch for an LNG pneumatic dispensing gun according to claim 1, characterized in that: The second fixing ring (304) is located below the first fixing ring (303), the third fixing ring (305) is located below the second fixing ring (304), and the fourth fixing ring (306) is located below the third fixing ring (305).

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