A liquid adding gun

Abstract

The utility model discloses a kind of liquid adding guns including outer cover, valve core, pressure support, inner barrel, liquid inlet pipe, driving mechanism, inner barrel is slidably installed in the pressure support, pressure support is cooperatively installed with the outer cover, the liquid inlet pipe is connected with the inner barrel, driving mechanism is installed in the end of the outer cover, the end of inner barrel is connected with liquid outlet joint, the end of this liquid outlet joint has the extension section that extends axially to inner barrel, the valve core includes sealing section and driving section, sealing section is installed in the extension section, driving section installs inner barrel, the outer wall of the extension section and the inner wall of inner barrel have the gap that is communicated with liquid inlet pipe, liquid hole is set up on the extension section, the liquid hole and the gap constitute liquid flow channel, the utility model is optimized to flow channel pertinence, effectively solve the problem of valve core reset in prior art, overall improve the use reliability and security of liquid adding gun.

Description

Technical Field

[0001] This utility model relates to liquid filling equipment, specifically to a filling gun for LNG filling. Background Technology

[0002] In the field of high-pressure liquid refueling, especially in the refueling of media with cryogenic and high-pressure characteristics such as liquefied natural gas (LNG), the refueling gun, as a core connection and control component, directly determines the safety, stability, and efficiency of the refueling process. The core function of this type of refueling gun is to achieve a reliable connection between the refueling pipe and the refueling head of the equipment being refueled, and to precisely control the flow of high-pressure liquid. This ensures efficient refueling while preventing media leakage and guaranteeing operational safety. Therefore, extremely high requirements are placed on the structural design, sealing performance, and on / off control accuracy of the refueling gun.

[0003] To meet the aforementioned high-pressure liquid refueling requirements, the applicant has conducted in-depth research on the structural optimization and functional implementation of the refueling gun during the early stages of technology development, and has successively proposed a number of related patent technologies. For example, in patent application number 2023236045226 entitled "A Pneumatic Refueling Gun" (hereinafter referred to as "Patent 1") and patent application number 2023236043432 entitled "An LNG Angle-Type Pneumatic Refueling Gun" (hereinafter referred to as "Patent 2"), both have achieved a stable connection between the refueling gun and the refueling head through innovative structural design, while also achieving effective control over the on / off of high-pressure liquid, providing a feasible technical solution for high-pressure liquid refueling operations.

[0004] However, in practical applications, it has been found that the liquid dispensing gun structures disclosed in Patents 1 and 2 still have room for improvement. Specifically, during the operation of these liquid dispensing guns, the flow path of the high-pressure liquid first passes through the middle area of ​​the traditional valve core (as shown in Figure 1 and 2). Figure 2 The liquid flows from the cavity area (as referred to in section 201) to the sealing lip, and finally enters the device being dispensed through the connector. This flow path design is prone to valve core reset problems during nozzle retraction or venting: because some gas or liquid remains in the middle area (cavity area) of the valve core, this residual gas or liquid generates a certain thrust during nozzle retraction or venting. This thrust interferes with the normal reset of the valve core, preventing it from accurately resetting to the preset position, thus causing poor valve core contact. Poor valve core contact not only affects the accuracy of the dispensing gun's control over liquid flow but may also lead to decreased sealing performance, media leakage, and other safety hazards, severely restricting the reliability and safety of the dispensing gun. Therefore, it is urgent to optimize and improve the existing dispensing gun structure to solve the problem of poor valve core reset. Utility Model Content

[0005] Therefore, in order to solve the above-mentioned shortcomings, this utility model provides a liquid dispensing gun, which overcomes the problem of inaccurate reset caused by the traditional valve core flow channel by optimizing the flow channel.

[0006] Specifically, a liquid dispensing gun includes an outer casing, a valve core, a pressure support, an inner barrel, an inlet pipe, and a drive mechanism. The inner barrel is slidably mounted on the pressure support, which is fitted into the outer casing. The inlet pipe is connected to the inner barrel. The drive mechanism is mounted on the end of the outer casing and is used to drive the inner barrel to move axially. An outlet connector is threaded to the end of the inner barrel, and the end of the outlet connector has an extension section extending axially into the inner barrel. The valve core includes a sealing section and a driving section. The extension section has a moving section, and the sealing section is installed on the extension section. The driving section is equipped with the inner gun barrel via a spring and a spring seat. The outer wall of the extension section and the inner wall of the inner gun barrel have a gap that communicates with the liquid inlet pipe. A liquid guide hole is provided on the extension section that communicates with the gap. The liquid guide hole and the gap form a liquid flow channel. When the sealing section contacts the sealing lip provided at the liquid outlet connector, the liquid guide hole is closed and the liquid flow channel is blocked. When the sealing section separates from the sealing lip, the liquid guide hole is unobstructed and the liquid flow channel is unobstructed.

[0007] Optionally, the drive mechanism is connected to the outer sleeve via a connecting rod. A spring that contacts the pressure support is mounted on the connecting rod, and a spring sleeve is fixedly installed on the connecting rod. This arrangement extends the spring outward, facilitating the enlargement of the spring size to improve elasticity. Simultaneously, the spring sleeve protects the spring and reduces the risk of it being pinched.

[0008] The driving mechanism includes a driving cylinder, in which a main piston and a secondary piston are installed. The main piston is connected to the inner barrel, and the secondary piston is located on the other side of the main piston. The main piston and the secondary piston divide the cylinder body of the driving cylinder into a first chamber, a second chamber and a third chamber in sequence. The first chamber is on the inner barrel side, and the inner diameter of the third chamber is larger than the inner diameter of the first chamber, or the effective area of ​​the secondary piston on the third chamber side is larger than the effective area of ​​the main piston on the first chamber side. An unlocking valve and an exhaust valve for controlling the intake or exhaust of the first chamber, the second chamber, and the third chamber are installed on the drive cylinder.

[0009] The above design separates the exhaust and unlocking processes. During the unlocking process, the valve can only be unlocked after the exhaust is exhausted. That is, the exhaust valve must be controlled before or simultaneously with the unlocking valve to avoid accidental unlocking without exhausting the valve.

[0010] Optionally, the control lever of the exhaust valve is located inside the handle, which is fixedly connected to the outer wall of the cylinder.

[0011] Optionally, the inner gun barrel and the liquid outlet connector are connected by threads, and a sealing ring is provided between the end faces of the threads; The end of the inlet pipe is fitted with a connector via a threaded connection, and a sealing ring is provided between the end faces at the threaded connection.

[0012] This design improves sealing performance and facilitates the installation and removal of the sealing ring.

[0013] This utility model has the following advantages: The liquid dispensing gun provided by this utility model solves the problem of valve core resetting failure in the prior art by improving the flow channel structure, and improves the overall reliability of the liquid dispensing gun.

[0014] Furthermore, compared to the flow channel design of "liquid flowing through the central cavity area of ​​the valve core to the sealing lip" used in Patents 1 and 2 in the background art, this utility model optimizes the liquid flow channel structure, adjusting the liquid flow channel from "central cavity area of ​​the valve core" to "the gap between the outer wall of the extension section and the inner wall of the inner gun barrel + the liquid guide hole on the extension section". By extending the protective section to protect the middle part of the valve core, the impact of liquid on the valve body is reduced. After the improvement, it is not necessary to pass through the central area of ​​the valve core, but to directly deliver the liquid to the outlet through the flow channel formed by the gap and the liquid guide hole; when the sealing section contacts / separates from the sealing lip, the flow channel is blocked / unblocked only by the closure / opening of the liquid guide hole. This fundamentally avoids the problem of residual gas or liquid in the middle area of ​​the valve core generating thrust, completely eliminates the hidden danger of thrust interfering with valve core reset during gun retraction or venting, ensures that the valve core can accurately reset to the preset position, effectively solves the problem of poor valve core contact, and thus ensures the accuracy of liquid flow control by the liquid filling gun, reduces the safety risks such as sealing failure and media leakage caused by poor valve core reset, and improves the stability of the high-pressure liquid filling process.

[0015] Meanwhile, addressing the issue in patents 1 and 2 of the background technology that "a single control valve controls both venting and unlocking, which can easily lead to accidental unlocking due to misoperation, causing the filling gun to eject without venting," this utility model uses independent unlocking and venting valves to control the air intake / venting of each chamber. This design not only achieves separate control of venting and unlocking but also eliminates the misoperation of "unlocking without venting" through the logical constraint of "venting before unlocking" (controlling the unlocking valve must precede or simultaneously control the venting valve). Even if the operator develops a habitual action due to operational fluency, they cannot skip the venting step and unlock directly, completely avoiding the risk of the filling gun suddenly ejecting, significantly improving operational safety, and is especially suitable for scenarios with extremely high requirements for operational precision and safety, such as high-pressure LNG refueling.

[0016] Meanwhile, sealing performance is one of the core performance indicators of a liquid dispensing gun, and the seals require regular replacement and maintenance. This utility model optimizes the sealing design of key connection parts: on the one hand, a sealing ring is set between the threaded connection end faces of the inner gun tube and the liquid outlet connector; on the other hand, a sealing ring is also set between the threaded connection end faces of the liquid inlet pipe end connector. The advantages of this design are: firstly, through the dual protection of "threaded connection + end face sealing ring", the sealing performance of key connections is greatly improved, effectively preventing high-pressure liquid from leaking from the connection gap; secondly, the threaded connection method facilitates disassembly. When the sealing ring needs to be replaced or maintained, it can be quickly removed by simply disassembling the threaded connection, without disassembling complex structures, significantly reducing the maintenance difficulty of the seals, shortening maintenance time, and improving the ease of use and service life of the liquid dispensing gun.

[0017] Furthermore, in the optional optimized drive mechanism scheme of this utility model, the spring is placed outside the pressure support component via a connecting rod, and a spring sleeve is provided accordingly. This design brings dual benefits: First, after the spring is moved outward, it is not limited by the internal space of the drive mechanism, and the spring specification can be enlarged according to actual needs, thereby improving the elastic performance of the spring and providing a more stable driving force for the axial movement of the inner gun barrel, further ensuring the accuracy of the liquid dispensing gun on / off control; Second, the spring sleeve not only protects the spring from corrosion or collision damage due to external impurities during long-term use, but also effectively prevents the risk of the operator being pinched due to accidental contact with the spring during operation, thus balancing equipment reliability and operational safety. Attached Figure Description

[0018] Figure 1 These are schematic diagrams of the liquid flow channels in Patents 1 and 2 described in the background section; Figure 2 This is a schematic diagram of the valve core structure in Patents 1 and 2 described in the background art (liquid-facing side state). Figure 3 This is a three-dimensional structural diagram of the liquid dispensing gun described in this utility model; Figure 4 This is a three-dimensional structural diagram of the liquid dispensing gun described in this utility model from another perspective; Figure 5 This is a cross-sectional schematic diagram of the liquid dispensing gun described in this utility model; Figure 6 This is a schematic diagram of the structure of the valve core and the liquid outlet connector of the liquid dispensing gun described in this utility model; Figure 7 This is a schematic diagram of the valve core of the liquid dispensing gun described in this utility model (liquid-facing side). Figure 8 This is a three-dimensional structural diagram of the driving mechanism of the liquid dispensing gun described in this utility model; In the diagram: 1. Unlock valve; 2. Pad; 3. Drive cylinder; 31. First chamber; 32. Second chamber; 33. Third chamber; 4. Handle; 5. Inlet pipe; 6. Inner barrel; 7. Pressure support; 8. Claw; 9. Outer sleeve; 10. Outlet connector; 101. Extension section; 102. Guide hole; 11. Valve core; 111. Sealing section; 112. Drive section; 12. Spring sleeve; 13. Connecting rod; 14. Secondary piston; 15. Main piston; 16. Exhaust valve; 161. Control lever. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0020] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying 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.

[0021] As described in the background section, the liquid dispensing gun structures disclosed in Patents 1 and 2 still have room for improvement. Specifically, during the operation of these liquid dispensing guns, the flow path of the high-pressure liquid first passes through the middle region of the valve core (as shown in Figure 1 and 2). Figure 2 The liquid flows from the cavity area (as referred to in section 201) to the sealing lip, and finally enters the device being dispensed through the connector. This flow path design is prone to valve core reset problems during nozzle retraction or venting: because some gas or liquid remains in the middle area (cavity area) of the valve core, this residual gas or liquid generates a certain thrust during nozzle retraction or venting. This thrust interferes with the normal reset of the valve core, preventing it from accurately resetting to the preset position, thus causing poor valve core contact. Poor valve core contact not only affects the accuracy of the dispensing gun's control over liquid flow but may also lead to decreased sealing performance, media leakage, and other safety hazards, severely restricting the reliability and safety of the dispensing gun. Therefore, it is urgent to optimize and improve the existing dispensing gun structure to solve the problem of poor valve core reset.

[0022] Based on the above reasons, this embodiment provides a liquid dispensing gun, including an outer casing 9, a valve core 11, a pressure support 7, an inner gun barrel 6, a liquid inlet pipe 5, and a drive mechanism. The inner gun barrel 6 is slidably mounted on the pressure support 7, and the pressure support 7 is fitted with the outer casing 9. The liquid inlet pipe 5 is connected to the inner gun barrel 6. The drive mechanism is mounted on the end of the outer casing and is used to drive the inner gun barrel to move axially. The end of the inner gun barrel (via thread) is connected to a liquid outlet connector 10, and the end of the liquid outlet connector has an extension section 101 extending axially into the inner gun barrel. The valve core includes a sealing section 1. The sealing section 111 is installed on the extension section 101 via a sealing ring. The drive section is installed on the inner gun barrel via a spring and a spring seat. The outer wall of the extension section 101 and the inner wall of the inner gun barrel 6 have a gap that communicates with the liquid inlet pipe. A liquid guide hole 102 communicating with the gap is provided on the extension section. The liquid guide hole and the gap form a liquid flow channel. When the sealing section contacts the sealing lip opened on the liquid outlet connector, the liquid guide hole is closed and the liquid flow channel is blocked. When the sealing section separates from the sealing lip, the liquid guide hole is unobstructed and the liquid flow channel is in a smooth state.

[0023] The aforementioned technical features optimize the liquid flow channel structure, changing it from the "central cavity area of ​​the valve core" to "the gap between the outer wall of the extension section and the inner wall of the inner gun barrel + the liquid guide hole on the extension section." By extending the protective section to protect the central area of ​​the valve core, the impact of the liquid on the valve body is reduced. After the improvement, the liquid no longer needs to pass through the central area of ​​the valve core, but is directly delivered to the outlet through the flow channel formed by the gap and the liquid guide hole. When the sealing section contacts / separates from the sealing lip, the flow channel is blocked / unblocked only by the closure / opening of the liquid guide hole. This fundamentally avoids the problem of residual gas or liquid in the central area of ​​the valve core generating thrust, completely eliminating the hidden danger of thrust interfering with valve core reset during gun retraction or venting, ensuring that the valve core can accurately reset to the preset position, effectively solving the problem of poor valve core contact, thereby ensuring the accuracy of the liquid dispensing gun's control over liquid flow, reducing safety risks such as seal failure and media leakage caused by poor valve core reset, and improving the stability of the high-pressure liquid dispensing process.

[0024] As described in Patent 2, the spring in the connecting rod is internal. However, due to space limitations, the spring's specifications cannot be increased. Therefore, in one embodiment, the drive mechanism is connected to the outer sleeve 9 via the connecting rod 13. A spring that contacts the pressure support is installed on the connecting rod, and a spring sleeve 12 is fixedly installed on the connecting rod. This external arrangement allows for easier expansion of the spring's specifications, improving its elasticity. Simultaneously, the spring sleeve protects the spring and reduces the risk of it being pinched.

[0025] As described in Patents 1 and 2 in the background art, the cylinder is controlled by a control valve. When the control valve is in use, pulling the lever will release air (release pressure) when the lever is moved to a higher position, and unlocking the cylinder when the lever is moved to a second position. Although this operation is very convenient, once the operator becomes very proficient, they often pull the lever directly to the second position, which will unlock the cylinder without releasing air. This can easily cause the dispensing gun to suddenly spring off, resulting in an uncontrollable operational hazard.

[0026] For the reasons mentioned above, the driving mechanism includes a driving cylinder 3, in which a main piston 15 and a secondary piston 14 are installed. The main piston 15 is connected to the inner barrel 6, and the secondary piston 14 is located on the other side of the main piston. The main piston and the secondary piston divide the cylinder body of the driving cylinder into a first chamber 31, a second chamber 32 and a third chamber 33 in sequence. The first chamber is on the inner barrel side, and the inner diameter of the third chamber is larger than the inner diameter of the first chamber, or the working area of ​​the secondary piston on the third chamber side is larger than the working area of ​​the main piston on the first chamber side. An unlocking valve 1 and an exhaust valve 16 for controlling the intake or exhaust of the first, second, and third chambers are installed on the drive cylinder. The unlocking valve and the exhaust valve are installed through a gasket 2 with a through hole. The intake or exhaust passage of the exhaust valve or the unlocking valve is connected to the chamber of the cylinder through the through hole on the gasket. For example, the exhaust valve is a two-position three-way valve in the prior art, and the unlocking valve is a two-position five-way valve in the prior art.

[0027] The control lever 161 of the exhaust valve is located inside the handle 4. The handle is fixedly connected to the outer wall of the cylinder so that the operator can easily control the control lever of the exhaust valve when holding the handle.

[0028] For example, before unlocking, pressure needs to be released (i.e., the venting process described above). During venting, the first and third chambers are connected through the venting valve. Under the control of the unlocking valve, venting is performed on the second chamber, while simultaneously venting is performed on either the first or third chamber (since the first and third chambers are connected in this state, venting to either chamber is the same). Because the inner diameter of the third chamber is larger than that of the first chamber, or the effective area of ​​the auxiliary piston on the third chamber side is larger than that of the main piston on the first chamber side, the third and second chambers have the same air pressure. Under pressurized gas, the auxiliary piston moves to the stop point near the main piston, thus forming the depressurized state of the liquid filling gun. After the depressurization is completed, the first and third chambers are separated by controlling the exhaust valve. Under the action of the unlocking valve, air is introduced into the first chamber, and under the action of the exhaust valve, air is vented into the third chamber. Thus, the main piston and auxiliary piston are pushed to the rear stop point. As the main piston continues to move backward, it drives the inner gun barrel to move backward and drives the pawl 8 to open, thus forming the unlocked state of the liquid filling gun. The liquid filling gun can be detached from the liquid filling port. When the valve stem of the exhaust valve is released, the entire mechanism returns to the aforementioned depressurized state.

[0029] The structure of the chuck, the assembly structure of the chuck and the outer sleeve, the cooperation between the chuck and the pressure support, and the process of opening or locking the chuck in this application are the same as those of the applicant's prior patent 1; or the aforementioned patent 2; or the utility model patent with publication number CN212430437U entitled "A Manual Liquid Dispensing Gun"; or the utility model patent with publication number CN209622463U entitled "A Manual Liquid Dispensing Gun".

[0030] The aforementioned design features enable independent unlocking and venting valves to control the air intake / venting of each chamber. This not only achieves separate control of venting and unlocking but also eliminates the possibility of accidental unlocking without venting through the logical constraint of "venting before unlocking" (controlling the unlocking valve must precede or be simultaneous with controlling the venting valve). Even if the operator develops a habitual action due to operational fluency, they cannot skip the venting step and unlock directly, completely avoiding the risk of the filling nozzle suddenly detaching and significantly improving operational safety. This is especially suitable for scenarios with extremely high requirements for operational precision and safety, such as high-pressure LNG refueling.

[0031] Since sealing is a crucial design element in liquid dispensing guns, especially at structural joints, the gaskets need to be replaced or maintained regularly.

[0032] Therefore, in one embodiment, the inner gun barrel 6 and the liquid outlet connector 5 are connected by threads, and a sealing ring is provided between the end faces of the threads; The end of the inlet pipe is fitted with a connector via a threaded connection, and a sealing ring is provided between the end faces at the threaded connection.

[0033] This design improves sealing performance and facilitates the installation and removal of the sealing ring.

[0034] This invention effectively solves the problems of valve core resetting failure, high risk of misoperation, and inconvenient seal maintenance in the prior art through targeted optimization of the drive control method and sealing connection design, and improves the overall reliability, safety and practicality of the liquid dispensing gun.

[0035] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A liquid dispensing gun, comprising an outer casing, a valve core, a pressure support, an inner barrel, an inlet pipe, and a drive mechanism, wherein the inner barrel is slidably mounted on the pressure support, the pressure support is fitted with the outer casing, the inlet pipe is connected to the inner barrel, and the drive mechanism is mounted on the end of the outer casing for driving the inner barrel to move axially, characterized in that: The end of the inner barrel is connected to a liquid outlet connector. The end of the liquid outlet connector has an extension section extending axially into the inner barrel. The valve core includes a sealing section and a driving section. The sealing section is installed on the extension section. The driving section is installed on the inner barrel via a spring and a spring seat. The outer wall of the extension section and the inner wall of the inner barrel have a gap communicating with the liquid inlet pipe. A liquid guide hole communicating with the gap is opened on the extension section. The liquid guide hole and the gap form a liquid flow channel. When the sealing section contacts the sealing lip opened on the liquid outlet connector, the liquid guide hole is closed and the liquid flow channel is blocked. When the sealing section separates from the sealing lip, the liquid guide hole is unobstructed and the liquid flow channel is unobstructed.

2. The liquid dispensing gun according to claim 1, characterized in that: The drive mechanism is connected to the outer sleeve via a connecting rod. A spring that contacts the pressure support is installed on the connecting rod, and a spring sleeve is fixedly installed on the connecting rod.

3. The liquid dispensing gun according to claim 1, characterized in that: The driving mechanism includes a driving cylinder, in which a main piston and a secondary piston are installed. The main piston is connected to the inner barrel, and the secondary piston is located on the other side of the main piston. The main piston and the secondary piston divide the cylinder body of the driving cylinder into a first chamber, a second chamber and a third chamber in sequence. The first chamber is on the inner barrel side, and the inner diameter of the third chamber is larger than the inner diameter of the first chamber, or the working area of ​​the secondary piston on the third chamber side is larger than the working area of ​​the main piston on the first chamber side. An unlocking valve and an exhaust valve for controlling the intake or exhaust of the first chamber, the second chamber, and the third chamber are installed on the drive cylinder.

4. The liquid dispensing gun according to claim 1, characterized in that: The exhaust valve's control lever is located inside the handle, which is fixedly connected to the outer wall of the cylinder block.

5. The liquid dispensing gun according to claim 1, characterized in that: The inner gun barrel and the liquid outlet connector are connected by threads, and a sealing ring is provided between the end faces of the threads; The end of the inlet pipe is fitted with a connector via a threaded connection, and a sealing ring is provided between the end faces at the threaded connection.

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