Movable grinding material filling machine for gas cylinder

Abstract

The invention relates to the technical field of gas cylinder filling, and discloses a movable grinding material filling machine for a gas cylinder, the movable grinding material filling machine comprises a hoisting assembly and a material nozzle, the hoisting assembly comprises a hoisting frame and a hopper frame which slide up and down, the hoisting frame is connected to a hoisting driving mechanism to perform lifting movement, a plurality of hoppers are arranged in the hopper frame, and the material nozzle is connected with the hoisting driving mechanism. A plurality of gas conveying assemblies are arranged on the lifting frame, and gas spraying pipes connected with the gas conveying assemblies penetrate through the corresponding hoppers from top to bottom; the lower portion of the material nozzle is detachably fixed to a bottle opening of the gas bottle, and the inner wall of the upper portion of the material nozzle is matched with the outer wall of the lower portion of the hopper in shape. When the lifting frame is lifted upwards for filling, the bottom end of the air spraying pipe is higher than a discharging opening of the hopper, and a gap is reserved between the outer wall of the lower portion of the hopper and the inner wall of the upper portion of the material nozzle. When filling is completed, the lifting frame moves downwards, the bottom end of the air spraying pipe downwards blocks a discharging opening of the hopper, and the outer wall below the hopper downwards fits the inner wall above the nozzle. The device is integrated equipment capable of synchronously realizing filling and explosion-proof detection.

Description

Technical Field

[0001] This invention relates to the field of gas cylinder filling technology, specifically a mobile abrasive filling machine for gas cylinders. Background Technology

[0002] Currently, equipment used for abrasive filling of gas cylinders generally suffers from problems such as limited functionality, low automation, and lack of safety testing. Most existing abrasive filling equipment only has simple material feeding and filling functions, unable to simultaneously test the cylinder's seal and explosion-proof performance. This makes it difficult to meet the safety testing requirements for gas cylinders used in flammable and explosive media scenarios, and it does not belong to the category of integrated instruments and meters capable of simultaneously performing filling and explosion-proof testing.

[0003] In practical use, existing equipment relies on the abrasive's own weight for filling, which has drawbacks such as slow filling speed, low filling efficiency, and poor air expulsion from the cylinder, leading to pressure buildup. This results in incomplete abrasive filling and a long filling cycle. Furthermore, after filling, the cylinders need to be transported separately to the testing station for explosion-proof and sealing tests. This process is cumbersome, costly, and carries risks of cylinder collisions and abrasive leakage during transport, making it impossible to integrate filling and testing operations.

[0004] In addition, during filling, the abrasive material is easily ejected outward from the gap between the hopper and the docking structure by the airflow, resulting in material waste and dust pollution. The air jet pipe and the hopper have poor sealing performance, which can easily lead to problems such as air leakage and material blockage. This results in inaccurate subsequent air pressure test data and a high misjudgment rate, making it difficult to make a reliable judgment on the explosion-proof performance of the gas cylinder.

[0005] Therefore, in view of the shortcomings of existing technologies such as lack of synchronous explosion-proof detection function, slow filling speed, easy material leakage, low sealing detection accuracy, and inconvenience of mobile operation, there is an urgent need to develop a mobile abrasive filling machine that can complete the explosion-proof performance test of gas cylinders while filling, is suitable for detection and analysis in flammable and explosive scenarios, and integrates efficient filling and safety detection. Summary of the Invention

[0006] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a mobile abrasive filling machine for gas cylinders that enables simultaneous filling and explosion-proof seal testing. It boasts advantages such as fast filling speed, leak-proof operation, reliable sealing, accurate testing, flexible mobility, and suitability for safety testing in flammable and explosive environments. This invention solves the technical problems of existing gas cylinder abrasive filling equipment, including the inability to simultaneously test explosion-proof performance, slow filling speed, easy material leakage, low seal testing accuracy, and poor integration and mobility.

[0007] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: A mobile abrasive filling machine for gas cylinders includes a lifting assembly and a nozzle. The lifting assembly includes a lifting frame and a hopper frame that slide vertically relative to each other. The lifting frame is connected to a lifting drive mechanism for vertical movement. Multiple hoppers are arranged inside the hopper frame, and multiple air delivery assemblies are arranged on the lifting frame. Each air delivery assembly is connected to an air jet pipe that passes through the corresponding hopper from top to bottom. The nozzle is detachably fixed to the mouth of the gas cylinder. The upper inner wall of the nozzle is adapted to the shape of the lower outer wall of the hopper. When the lifting frame is used for filling, the bottom end of the air jet pipe is higher than the hopper's discharge port, and a gap is left between the lower outer wall of the hopper and the upper inner wall of the nozzle. When filling is completed, the lifting frame moves downward, the bottom end of the air jet pipe blocks the hopper's discharge port downward, and the lower outer wall of the hopper fits against the upper inner wall of the nozzle.

[0008] Preferably, the inner wall of the feed nozzle is provided with a baffle ring, which includes a rigid annular plate inclined upward and a soft annular pad inclined downward. The rigid annular plate is fixed to the inner wall of the feed nozzle, and the soft annular pad is fixed to the lower surface of the rigid annular plate. The width of the soft annular pad is longer than the width of the rigid annular plate, so that the soft annular pad first fits against the outer wall of the hopper. A pressure sensor is also provided on the lower surface of the rigid annular plate, and a groove is provided on the lower surface of the soft annular pad on the side that fits against the inner wall of the feed nozzle. The inner diameter below the feed nozzle is smaller than the inner diameter below the hopper.

[0009] Preferably, the jet pipe has an elliptical plug near the lower jet nozzle. The plug is divided into two halves: an upper hard plug and a lower soft plug. The soft plug has a side air passage. The air outlet of the side air passage is located on the lower surface of the soft plug, which is in contact with the inner wall of the hopper. The air inlet of the side air passage is connected to the internal channel of the jet pipe. The side air passage has an expansion chamber inside the soft plug.

[0010] Preferably, the filling machine further includes a frame, on which a guide rail is vertically mounted, and the hoisting assembly slides along the guide rail in a sliding fit with the guide rail.

[0011] Preferably, the hoisting drive mechanism is installed at the top position within the frame, and the hoisting drive mechanism is connected to the lifting frame via a hook transmission assembly to drive the lifting frame to rise and fall.

[0012] Preferably, both the air supply assembly and the jet pipe are fixedly mounted on the lifting frame, and the air supply pipe of the air supply assembly is connected to the jet pipe.

[0013] Preferably, the lifting frame is also fixedly provided with a hook, which is slidably connected to the hopper frame and is provided with a limit block.

[0014] Preferably, the jet pipe has a central cavity inside, the inner diameter of which is larger than the inner diameter of the main channel of the jet pipe, and the air inlet of the side air passage is located at the bottom of the central cavity.

[0015] Preferably, the expansion chamber is an annular air chamber located around the central cavity, and the air inlet and outlet of the side air passage are both connected to the expansion chamber.

[0016] Preferably, the side air passage extends obliquely downwards, and the air outlet of the side air passage is located at the position where the lower surface of the soft block is in contact with the inner wall of the hopper.

[0017] (III) Beneficial Effects Compared with the prior art, the present invention provides a mobile abrasive filling machine for gas cylinders, which has the following advantages: This invention utilizes a combination of a jet pipe, a hopper, and a nozzle. Firstly, during the filling stage, the gas delivery assembly continuously sprays air, using the airflow to propel the abrasive material downwards rapidly, significantly increasing the filling speed. Simultaneously, the gap between the hopper and the nozzle allows air to escape from the bottle, preventing pressure buildup and obstruction of material flow. Secondly, during the testing stage, after the discharge port is sealed and the cavity is sealed, the jet pipe continuously sprays air into the bottle to maintain pressure. The overall sealing performance of the gas cylinder is tested using this pressure, simultaneously assessing the bottle's explosion-proof performance, thus achieving simultaneous completion of filling and explosion-proof testing.

[0018] This invention utilizes a barrier ring installed between the inner wall of the nozzle and the outer wall of the hopper. This serves several purposes: first, it prevents material from leaking out during filling; second, it creates a seal between the hopper and nozzle during detection; and third, a pressure sensor within the barrier ring detects pressure changes within the gas cylinder, thus determining if a leak has occurred. Furthermore, the nozzle protrudes inwards from the bottom relative to the bottom of the hopper. This serves two purposes: first, it concentrates the outward-flowing airflow onto the side that adheres to the inner wall of the nozzle, ensuring that all material is blocked by the barrier ring; and second, it creates a flared opening at the hopper and nozzle, wider at the top and narrower at the bottom, which facilitates accelerated airflow and propels the material into the gas cylinder.

[0019] This invention provides several advantages. First, by installing an elliptical plug consisting of a hard plug and a soft plug on the jet pipe, the soft plug can adhere to the inner wall of the hopper, improving the seal between the jet pipe and the hopper. Furthermore, the elliptical plug does not affect the downward filling of material during filling. Second, a side air passage can be set inside the soft plug, thereby increasing the side airflow and improving the filling speed. Third, during testing, the air outlet of the side air passage is blocked by the inner wall of the hopper, and the expansion chamber inside the soft plug expands under increased air pressure, which improves the sealing performance of the soft plug. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 This is a schematic diagram of the hoisting assembly of the present invention.

[0022] Figure 3 This is a schematic diagram of the hopper frame of the present invention.

[0023] Figure 4 This is a schematic diagram of the lifting frame of the present invention.

[0024] Figure 5 This is a schematic diagram of the jet pipe of the present invention.

[0025] Figure 6 This is a schematic diagram of the nozzle structure of the present invention.

[0026] Figure 7 This is a cross-sectional perspective view of the nozzle of the present invention.

[0027] Figure 8 This is a cross-sectional perspective view of the air jet pipe, hopper, and nozzle of the present invention, showing the filling process being carried out on the hoisting drive mechanism.

[0028] Figure 9 This is a cross-sectional perspective view of the air jet pipe, hopper, and nozzle of the present invention, showing the airtightness test being performed on the hoisting drive mechanism.

[0029] In the diagram: 1. Frame; 11. Guide rail; 2. Lifting assembly; 21. Lifting frame; 211. Hook; 22. Hoist frame; 23. Air jet pipe; 24. Hoist; 25. Air supply assembly; 26. Plug; 231. Air jet nozzle; 232. Middle cavity; 261. Hard plug; 262. Soft plug; 2621. Side air passage; 2622. Expansion chamber; 3. Material nozzle; 31. Barrier ring; 311. Hard annular plate; 312. Soft annular pad; 3121. Groove; 32. Sealing ring; 4. Gas cylinder; 5. Lifting drive mechanism; 51. Hook transmission assembly. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] In addition, a fixed connection refers to a connection in which parts or components are fixed and there is no relative movement; a transmission connection refers to a connection in which mechanical motion or torque is transmitted to other working parts through a transmission component; a sliding connection refers to a connection in which two objects are in contact but not fixed and can slide relative to each other; and a rotational connection refers to a connection in which two objects are in contact but not fixed and can rotate relative to each other.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] Example 1: This embodiment provides a mobile abrasive filling machine for gas cylinders, which has the following technical features.

[0035] Please see Figure 1-9 Because existing technologies lack cylinder performance testing capabilities and have slow filling speeds when filling gas cylinders with abrasives, this invention provides a mobile abrasive filling machine for gas cylinders, comprising a lifting assembly 2 and a nozzle 3. The lifting assembly 2 includes a lifting frame 21 and a hopper frame 22 that slide vertically together. The lifting frame 21 is connected to a lifting drive mechanism 5 for lifting and lowering movement. Multiple hoppers 24 are provided inside the hopper frame 22. Multiple air delivery assemblies 25 are provided on the lifting frame 21, and each air delivery assembly 25 is connected to... The jet pipe 23 passes through the corresponding hopper 24 from top to bottom; the nozzle 3 is detachably fixed at the mouth of the gas cylinder 4, and the upper inner wall of the nozzle 3 is adapted to the shape of the lower outer wall of the hopper 24; when the lifting frame 21 is hoisted upward for filling, the bottom end of the jet pipe 23 is higher than the discharge port of the hopper 24, and there is a gap between the lower outer wall of the hopper 24 and the upper inner wall of the nozzle 3; when filling is completed, the lifting frame 21 moves downward, the bottom end of the jet pipe 23 blocks the discharge port of the hopper 24 downward, and the lower outer wall of the hopper 24 fits against the upper inner wall of the nozzle. This invention utilizes the coordinated arrangement of an air jet pipe 23, a hopper 24, and a nozzle 3. Firstly, during the filling stage, the air supply assembly 25 continuously sprays air, using the airflow to propel the abrasive material downwards rapidly, significantly increasing the filling speed. Simultaneously, the gap between the hopper 24 and the nozzle 3 helps to expel air from the bottle, preventing pressure buildup and obstruction of material flow. Secondly, during the testing stage, after the discharge port is sealed and the cavity is sealed, the air jet pipe 23 continuously sprays air into the bottle to maintain pressure. The overall sealing performance of the gas cylinder 4 is tested using this pressure, simultaneously assessing the bottle's explosion-proof performance, thus achieving simultaneous completion of filling and explosion-proof testing.

[0036] like Figure 1As shown, the filling machine further includes a frame 1, on which a guide rail 11 is vertically mounted. The hoisting assembly 2 slides along the guide rail 11. Casters are installed at the bottom of the frame 1 to facilitate the movement and repositioning of the entire machine. Channels are provided on both sides of the frame 1 to facilitate the entry of the gas cylinder 4 into the frame 1 for filling operations.

[0037] like Figure 1-2 As shown, in a further configuration, the hoisting drive mechanism 5 is installed at the top position within the frame 1. The hoisting drive mechanism 5 is connected to the lifting frame 21 via the hook transmission assembly 51, and is used to drive the lifting frame 21 to rise and fall. To achieve the lifting and lowering of the lifting frame 21, the present invention provides two technical solutions. In the first solution, the hoisting drive mechanism 5 is a rotary motor, and the hook transmission assembly 51 is a chain. The rotary motor drives the lifting frame 21 to rise and fall via the chain. A counterweight is provided on the lifting frame 21 so that when the lifting frame 21 descends, it can rely on its own weight to press the nozzle 3, hopper 24, and jet pipe 23 together. The air pump and other gas delivery devices installed on the lifting frame 21 can also be used as counterweights. In the second solution, the hoisting drive mechanism 5 is a telescopic motor, telescopic hydraulic cylinder, or telescopic pneumatic cylinder, and the hook transmission assembly 51 is a push rod. The hoisting drive mechanism 5 directly applies downward pressing force.

[0038] like Figure 2 and Figure 4 As shown, the air supply assembly 25 and the jet pipe 23 are both fixedly installed on the lifting frame 21. The air supply pipe of the air supply assembly 25 is connected to the jet pipe 23. Since the air supply pipe of the air supply assembly 25 is not rigid enough to support the downward pressure of the lifting frame 21, the jet pipe 23 with a larger diameter and stronger material is used as the main body for jetting and bearing pressure. The air supply assembly 25 is only used to supply gas into the jet pipe 23.

[0039] like Figure 3 As shown, further configured, the hopper 24 is fixedly mounted on the hopper frame 22, and the lower half of the hopper 24 is a conical funnel-shaped structure, which matches the shape of the upper half of the nozzle 3. Figure 6-7 As shown, the upper part of the nozzle 3 is a conical funnel-shaped structure, and the lower part of the nozzle 3 is a cylindrical structure, which can be directly inserted into the mouth of the gas cylinder 4; a sealing ring 32 is provided between the lower part of the nozzle 3 and the mouth of the gas cylinder 4 to achieve a seal at the mouth of the cylinder.

[0040] like Figure 4 As shown, in order to achieve the lifting of the lifting frame 21 and the lifting of the hopper frame 22 while ensuring the relative sliding between the lifting frame 21 and the hopper frame 22, the present invention also fixes a hook 211 on the lifting frame 21. The hook 211 is slidably connected to the hopper frame 22 and is provided with a limit block.

[0041] In an optional embodiment, such as Figure 6-9 As shown, when venting air through the gap between the nozzle 3 and the hopper 24, the filling material may be carried out of the gap by the airflow, resulting in material waste. Therefore, in this invention, a baffle ring 31 is provided on the inner wall of the nozzle 3. The baffle ring 31 includes a rigid annular plate 311 inclined upward and a soft annular pad 312 inclined downward. The rigid annular plate 311 is fixed to the inner wall of the nozzle 3, and the soft annular pad 312 is fixed to the lower surface of the rigid annular plate 311. The width of the soft annular pad 312 is longer than the width of the rigid annular plate 311, so that the soft annular pad 312 first fits against the outer wall of the hopper 24. A pressure sensor is also provided on the lower surface of the rigid annular plate 311. A groove 3121 is provided on the side of the soft annular pad 312 that fits against the inner wall of the nozzle 3. The inner diameter of the nozzle 3 is smaller than the inner diameter of the hopper 24. This invention provides a barrier ring 31 between the inner wall of the nozzle 3 and the outer wall of the hopper 24. This serves several purposes: first, it prevents material from leaking out during filling; second, it creates a seal between the hopper 24 and the nozzle 3 during detection; and third, a pressure sensor within the barrier ring 31 detects pressure changes within the gas cylinder 4, thus determining if a leak has occurred. Furthermore, the nozzle 3 protrudes inwards from the bottom relative to the hopper 24. This serves two purposes: first, it concentrates the outward-flowing airflow on the side that adheres to the inner wall of the nozzle 3, ensuring that all material is blocked by the barrier ring 31; and second, it creates a flared opening at the hopper 24 and nozzle 3, wider at the top and narrower at the bottom, which facilitates faster airflow and allows the material to enter the gas cylinder 4.

[0042] In an optional embodiment, such as Figure 5 , Figure 8 and Figure 9As shown, insufficient sealing between the jet pipe 23 and the hopper 24 can lead to errors in air pressure detection. Therefore, in this invention, an elliptical plug 26 is provided near the lower jet outlet of the jet pipe 23. The plug 26 is divided into upper and lower halves, namely an upper hard plug 261 and a lower soft plug 262. A side air passage 2621 is provided inside the soft plug 262. The air outlet of the side air passage 2621 is located at the position where the lower surface of the soft plug 262 is in contact with the inner wall of the hopper 24. The air inlet of the side air passage 2621 is connected to the internal channel of the jet pipe 23. An expansion chamber 2622 is provided inside the soft plug 262 in the side air passage 2621. This invention provides an elliptical plug 26 on the jet pipe 23, consisting of a hard plug 261 and a soft plug 262. Firstly, the soft plug 262 fits snugly against the inner wall of the hopper 24, improving the seal between the jet pipe 23 and the hopper 24. Furthermore, the elliptical plug 26 does not hinder the downward filling of material during filling. Secondly, a side air passage 2621 is provided within the soft plug 262, increasing side airflow and improving the filling speed. Thirdly, during testing, the outlet of the side air passage 2621 is blocked by the inner wall of the hopper 24, and the expansion chamber 2622 within the soft plug 262 expands under increased air pressure, improving the seal of the soft plug 262.

[0043] like Figure 5 As shown, the hard block 261 is fixedly connected to the air outlet 231 near the lower end of the air jet pipe 23. The hard block 261 and the air jet pipe 23 are fixedly connected, such as by welding, to ensure structural strength and coaxiality. The soft block 262 is fixedly installed below the hard block 261. The soft block 262 is made of an elastic sealing material, such as silicone, and can flexibly fit against the inner wall of the hopper 24.

[0044] like Figure 5 As shown, further, since the air inlet of the side air passage 2621 provided in the soft block 262 needs to protrude inside the jet pipe 23, the jet pipe 23 is provided with a middle cavity 232. The inner diameter of the middle cavity 232 is larger than the inner diameter of the main channel of the jet pipe 23. The air inlet of the side air passage 2621 is located at the bottom of the middle cavity 232. The side air passage 2621 extends obliquely downward as a whole, and the air outlet is located at the position where the lower surface of the soft block 262 is in contact with the inner wall of the hopper 24, so that after the plug 26 is lowered, the air outlet of the expansion chamber 2622 is in contact with the inner wall of the hopper 24.

[0045] like Figure 5As shown, specifically, the expansion chamber 2622 is an annular air chamber located around the central chamber 232. The inlet and outlet of the side air passage 2621 are both connected to the expansion chamber 2622. When air pressure enters the expansion chamber 2622, it causes the soft plug 262 to expand outwards, improving the sealing effect. After the elliptical plug 26 descends, the soft plug 262 fits against the inner wall of the hopper 24, and the outlet of the side air passage 2621 is blocked by the inner wall of the hopper 24. During testing, the expansion chamber 2622 inflates, further improving the sealing performance.

[0046] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A mobile abrasive filling machine for gas cylinders, comprising a hoisting assembly (2) and a nozzle (3), characterized in that, The hoisting assembly (2) includes a lifting frame (21) and a hopper frame (22) that slide vertically together. The lifting frame (21) is connected to the hoisting drive mechanism (5) for lifting and lowering movement. Multiple hoppers (24) are provided inside the hopper frame (22). Multiple air supply assemblies (25) are provided on the lifting frame (21). The air supply pipes (23) connected to each air supply assembly (25) pass through the corresponding hopper (24) from top to bottom. The nozzle (3) is detachably fixed to the mouth of the gas cylinder (4), and the upper inner wall of the nozzle (3) is adapted to the shape of the lower outer wall of the hopper (24); When the lifting frame (21) is hoisted upward for filling, the bottom end of the jet pipe (23) is higher than the discharge port of the hopper (24), and there is a gap between the lower outer wall of the hopper (24) and the upper inner wall of the nozzle (3); when filling is completed, the lifting frame (21) moves downward, the bottom end of the jet pipe (23) blocks the discharge port of the hopper (24) downward, and the lower outer wall of the hopper (24) fits against the upper inner wall of the nozzle downward.

2. The mobile abrasive filling machine for gas cylinders according to claim 1, characterized in that, The inner wall of the nozzle (3) is provided with a barrier ring (31). The barrier ring (31) includes a hard annular plate (311) on the upper side and a soft annular pad (312) on the lower side. The hard annular plate (311) is fixed to the inner wall of the nozzle (3), and the soft annular pad (312) is fixed to the lower surface of the hard annular plate (311). The width of the soft annular pad (312) is longer than the width of the hard annular plate (311), so that the soft annular pad (312) first fits against the outer wall of the hopper (24). A pressure sensor is also provided on the lower surface of the hard annular plate (311). A groove (3121) is provided on the lower surface of the soft annular pad (312) on the side that fits against the inner wall of the nozzle (3). The inner diameter of the nozzle (3) is smaller than the inner diameter of the hopper (24).

3. A mobile abrasive filling machine for gas cylinders according to claim 2, characterized in that, The jet pipe (23) has an elliptical plug (26) near the lower jet outlet. The plug (26) is divided into two halves: an upper hard plug (261) and a lower soft plug (262). The soft plug (262) has a side air passage (2621) inside. The air outlet of the side air passage (2621) is located at the position where the lower surface of the soft plug (262) is in contact with the inner wall of the hopper (24). The air inlet of the side air passage (2621) is connected to the internal channel of the jet pipe (23). The side air passage (2621) has an expansion chamber (2622) inside the soft plug (262).

4. A mobile abrasive filling machine for gas cylinders according to claim 3, characterized in that, The filling machine also includes a frame (1), on which a guide rail (11) is vertically mounted. The hoisting assembly (2) is slidably engaged with the guide rail (11) and slides up and down along the guide rail (11).

5. A mobile abrasive filling machine for gas cylinders according to claim 3, characterized in that, The hoisting drive mechanism (5) is installed at the top position inside the frame (1). The hoisting drive mechanism (5) is connected to the lifting frame (21) through the hook transmission assembly (51) and is used to drive the lifting frame (21) to rise and fall.

6. A mobile abrasive filling machine for gas cylinders according to claim 3, characterized in that, The gas supply assembly (25) and the jet pipe (23) are both fixedly installed on the lifting frame (21), and the gas supply pipe of the gas supply assembly (25) is connected to the jet pipe (23).

7. A mobile abrasive filling machine for gas cylinders according to claim 3, characterized in that, The lifting frame (21) is also fixedly provided with a hook (211), which is slidably connected to the hopper frame (22) and is provided with a limit block.

8. A mobile abrasive filling machine for gas cylinders according to claim 3, characterized in that, The jet pipe (23) has a central cavity (232) inside. The inner diameter of the central cavity (232) is larger than the inner diameter of the main channel of the jet pipe (23). The air inlet of the side air passage (2621) is located at the bottom of the central cavity (232).

9. A mobile abrasive filling machine for gas cylinders according to claim 3, characterized in that, The expansion chamber (2622) is an annular air chamber located around the central chamber (232), and the air inlet and outlet of the side air passage (2621) are connected to the expansion chamber (2622).

10. A mobile abrasive filling machine for gas cylinders according to claim 3, characterized in that, The side air passage (2621) extends obliquely downward as a whole, and the air outlet of the side air passage (2621) is located at the position where the lower surface of the soft block (262) is in contact with the inner wall of the hopper (24).

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