Welding gun anti-return device
By employing a double-layer seal and a nested copper core structure, the sealing failure and delay issues of the welding torch anti-return device under high pressure and high temperature environments are solved, achieving efficient gas blocking and rapid response. The structure is compact and adaptable to the interior of the welding torch.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WEIXIN (GUANGZHOU) IND TECH CO LTD
- Filing Date
- 2025-05-21
- Publication Date
- 2026-05-12
AI Technical Summary
Traditional welding torch anti-return devices are prone to gas leakage due to seal failure in high-pressure or high-temperature environments, which cannot completely block flame propagation, and the reliance on mechanical springs or gas pressure difference triggering action has a delay problem.
It adopts a double-layer sealing structure, including a copper valve core and a nested copper core, combined with a guide structure and spring for stepped pressure regulation, forming a double seal and short-stroke fast response, and using turbulence effect to suppress gas backflow.
It effectively prevents high-pressure gas leakage, improves blocking efficiency by 90%, increases response speed by 60%, and has a compact overall structure that fits the internal space of the welding torch.
Smart Images
Figure CN224222919U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of gas welding technology, and in particular to a device for preventing welding torch from returning to its original position. Background Technology
[0002] In gas welding or cutting operations, backflow of gas can cause flashback, which is a major safety hazard. Existing anti-backflow devices often have the following problems:
[0003] Traditional backflow prevention devices typically employ a single-layer sealing design (such as a one-way valve or a simple sealing ring), which is prone to gas leakage due to seal failure under high pressure or high temperature environments, and cannot completely block flame propagation.
[0004] Most anti-backflow devices rely on mechanical springs or air pressure differentials for triggering, which results in delays. In existing technologies, anti-backflow devices often require additional components such as explosion-proof valves and cooling modules, leading to a bulky overall structure that is difficult to integrate into the welding torch. Utility Model Content
[0005] The main purpose of this invention is to provide a welding torch anti-backflow device, which aims to solve the problem that traditional anti-backflow devices typically employ a single-layer sealing design (such as a one-way valve or a simple sealing ring), which is prone to gas leakage due to seal failure under high pressure or high temperature environments, thus failing to completely block flame propagation. Most anti-backflow devices rely on mechanical springs or gas pressure differentials for triggering action, resulting in a technical problem of delay.
[0006] To achieve the aforementioned objective, the first aspect of this utility model provides a welding torch anti-return device, comprising:
[0007] The welding torch connector body, copper valve core, first copper core, second copper core, and first spring, second spring, and third spring;
[0008] The copper valve core is embedded in the inner cavity of the welding torch connector body, and its outer wall is provided with a first sealing ring, forming a first layer of sealing structure with the inner cavity of the welding torch connector body.
[0009] The first copper core is nested inside the copper valve core, and its outer wall is provided with a second sealing ring, forming a second sealing structure with the carbon steel core and the inner cavity of the welding torch connector;
[0010] The second copper core is nested inside the first copper core, and its head is provided with a third sealing ring;
[0011] One end of the first spring is supported on the end of the copper valve core, and the other end is supported on the end of the first copper core.
[0012] The second spring is mounted on the first copper core and supported at the end of the second copper core;
[0013] The third spring is installed on the outer wall of the second copper core and supported in the inner cavity of the first copper core;
[0014] The first copper core and the copper valve core are fitted together by a guide structure to prevent axial misalignment.
[0015] Furthermore, the first sealing ring is an annular structure and is disposed in the sealing groove on the outer wall of the copper valve core, forming a radial seal with the inner cavity of the welding torch connector.
[0016] The second sealing ring forms a bidirectional seal with the carbon steel core and the inner cavity of the welding torch connector.
[0017] Furthermore, the guide structure includes a guide groove on the inner wall of the copper valve core and a guide protrusion on the outer wall of the first copper core, which slide together to achieve axial alignment.
[0018] Furthermore, the elastic coefficients of the first spring, the second spring, and the third spring increase sequentially.
[0019] Furthermore, the third sealing ring at the head of the second copper core has a conical structure, which forms a sealing fit with the conical surface of the inner cavity of the welding torch connector.
[0020] Furthermore, the nested channels of the first copper core and the second copper core form an anti-backflow structure. The inner diameter of the channel gradually decreases along the airflow direction, forming turbulence to prevent gas backflow and thus suppress flame propagation.
[0021] Furthermore, the total axial stroke of the copper valve core and the first copper core is less than 15mm, constituting a short stroke.
[0022] Furthermore, the first sealing ring, the second sealing ring, and the third sealing ring are made of high-temperature resistant rubber materials with different hardnesses, wherein the Shore hardness of the first sealing ring is greater than that of the second sealing ring.
[0023] Beneficial effects:
[0024] 1. This utility model utilizes a double-layer seal and an integrated anti-backflow structure. The double seal between the first copper core and the copper valve core forms a double barrier, effectively preventing high-pressure gas leakage and backflow. The anti-backflow channel is designed with a nested, tapered configuration of the first and second copper cores. The inner diameter of the channel narrows along the airflow direction, utilizing turbulence to prevent gas backflow and thus suppress flame propagation. The blocking efficiency is 90% higher than that of traditional structures.
[0025] 2. The axial overlap design of the copper valve core and the first copper core in this utility model ensures a total stroke of ≤15mm, forming a stepped pressure regulation that can complete the sealing trigger within 0.5 seconds, increasing the response speed by 60%. Through the nested assembly of the copper valve core, the first copper core, and the second copper core, the overall volume and weight are reduced, making it suitable for the internal space of the welding torch. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the explosion-proof structure of a welding torch anti-return device according to an embodiment of this utility model;
[0027] Figure 2 This is a schematic diagram of the assembly structure of a welding torch anti-return device according to an embodiment of the present invention;
[0028] Figure 3 This is a cross-sectional structural schematic diagram of a welding torch anti-return device according to an embodiment of the present invention;
[0029] Figure 4 This is a schematic diagram of the copper valve core structure of the welding torch anti-return device according to an embodiment of this utility model;
[0030] Figure 5 This is a schematic diagram of the first copper core structure of the welding torch anti-return device according to an embodiment of the present invention.
[0031] in:
[0032] 1-Welding torch connector body; 2-Copper valve core; 21-First sealing ring; 3-First copper core; 31-Second sealing ring; 4-Second copper core; 41-Third sealing ring; 5-First spring; 6-Second spring; 7-Third spring; 8-Carbon steel core; 91-Guide groove; 92-Guide protrusion.
[0033] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0034] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.
[0035] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They 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, and therefore should not be construed as a limitation of this utility model. 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 indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly and specifically defined.
[0036] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0038] Reference Figures 1-5 An embodiment of this utility model provides a welding torch anti-return device, comprising:
[0039] The welding torch connector body 1, copper valve core 2, first copper core 3, second copper core 4, and first spring 5, second spring 6, and third spring 7;
[0040] The copper valve core 2 is embedded in the inner cavity of the welding torch connector body 1, and its outer wall is provided with a first sealing ring 21, forming a first layer of sealing structure with the inner cavity of the welding torch connector body;
[0041] The first copper core 3 is nested inside the copper valve core 2, and its outer wall is provided with a second sealing ring 31, which forms a second sealing structure with the carbon steel core 8 and the inner cavity of the welding gun connector.
[0042] The second copper core 4 is nested inside the first copper core 3, and its head is provided with a third sealing ring 41;
[0043] One end of the first spring 5 is supported at the end of the copper valve core 2, and the other end is supported at the end of the first copper core 3;
[0044] The second spring 6 is mounted on the first copper core 3 and supported at the end of the second copper core 4;
[0045] The third spring 7 is installed on the outer wall of the second copper core 4 and supported in the inner cavity of the first copper core 3;
[0046] The first copper core 3 and the copper valve core 2 are connected by a guide structure to prevent axial misalignment.
[0047] The first sealing ring 21 is an annular structure and is disposed in the sealing groove on the outer wall of the copper valve core 2, forming a radial seal with the inner cavity of the welding gun connector.
[0048] The second sealing ring 31 forms a bidirectional seal with the carbon steel core 8 and the inner cavity of the welding torch connector.
[0049] The nested channels of the first copper core 3 and the second copper core 4 form an anti-backflow structure. The inner diameter of the channel gradually decreases along the airflow direction, forming turbulence to prevent gas backflow and thus suppress flame propagation.
[0050] This embodiment features a double-layer sealing structure:
[0051] The copper valve core 2 is embedded in the inner cavity of the welding torch connector body 1, and the annular first sealing ring 21 on its outer wall forms a radial seal with the inner cavity of the connector body;
[0052] The first copper core 3 is nested inside the copper valve core 2. The double-lip second sealing ring 31 on its outer wall forms a bidirectional seal with the carbon steel core 8 and the inner cavity of the connector. The Shore hardness of the second sealing ring is lower than that of the first sealing ring in order to adapt to the deformation requirements of different sealing surfaces.
[0053] The second copper core 4 has a conical third sealing ring 41 at its head, which dynamically fits with the conical surface of the connector body cavity to form a third layer of seal.
[0054] Anti-tempering structure:
[0055] The inner diameter of the nested channel between the first copper core 3 and the second copper core 4 gradually decreases along the airflow direction, forming a turbulent zone to prevent gas backflow and thus suppress flame propagation; the total axial stroke of the copper valve core 2 and the first copper core 3 is ≤15mm, achieving short stroke and fast response.
[0056] When a flashback occurs, the second copper core 4 is pushed by the flame pressure, the third sealing ring 41 fits tightly against the conical surface, and at the same time the first copper core 3 moves backward under the action of the second spring 6, triggering a secondary sealing between the second sealing ring 31 and the carbon steel core 8.
[0057] Optionally, the guide structure includes a guide groove 91 on the inner wall of the copper valve core 2 and a guide protrusion 92 on the outer wall of the first copper core 3, which slide together to achieve axial alignment.
[0058] It should be noted that the guide structure consists of the guide groove 91 on the inner wall of the copper valve core 2 and the guide protrusion 92 on the outer wall of the first copper core 3, ensuring that there is no misalignment or displacement during axial movement.
[0059] Optionally, the elastic coefficients of the first spring 5, the second spring 6, and the third spring 7 increase sequentially.
[0060] It should be noted that the first spring 5 supports the copper valve core 2 and the first copper core 3, the second spring 6 is installed between the first copper core 3 and the second copper core 4, and the third spring 7 is fixed between the outer wall of the second copper core 4 and the inner cavity of the first copper core. The elastic coefficients of the three springs increase in the order of first spring 5 → second spring 6 → third spring 7, forming a stepped pressure regulation.
[0061] Optionally, the third sealing ring 41 at the head of the second copper core 4 is a conical structure, which forms a sealing fit with the conical surface of the inner cavity of the welding torch connector body 1.
[0062] The total axial stroke of the copper valve core 2 and the first copper core 3 is less than 15mm, constituting a short stroke.
[0063] The first sealing ring 21, the second sealing ring 31 and the third sealing ring 41 are made of high-temperature resistant rubber materials with different hardness, wherein the Shore hardness of the first sealing ring 21 is greater than that of the second sealing ring 31.
[0064] It should be noted that the first sealing ring 21 is made of fluororubber with a Shore hardness of 85A, which can withstand high temperatures up to 250℃; the second sealing ring 31 is made of silicone rubber with a Shore hardness of 70A, which meets the flexibility requirements of bidirectional sealing; the third sealing ring 41 is made of conical polytetrafluoroethylene, which forms a high-temperature self-compensating seal with the conical surface of the joint body.
[0065] illustrate:
[0066] Insert the copper valve core 2 into the inner cavity of the welding torch connector body 1, aligning it with the guide protrusion 92 through the guide groove 91; then install the first copper core 3 and the second copper core 4 in sequence, and fix them with the preload spring.
[0067] Normal welding: The gas flows through the channel between the copper valve core 2 and the first copper core 3, and the three springs work together to maintain the sealing gap;
[0068] Backfire prevention: When the flame impacts in the opposite direction, the second copper core 4 moves forward to block the channel, and the first copper core 3 moves backward to trigger the second sealing ring 31 for bidirectional sealing, thus doubly blocking the gas backflow propagation path.
[0069] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural or procedural transformations made based on the content of the present utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present utility model.
Claims
1. A welding torch anti-return device, characterized in that, include: The welding torch connector body (1), copper valve core (2), first copper core (3), second copper core (4), and first spring (5), second spring (6), and third spring (7); The copper valve core (2) is embedded in the inner cavity of the welding torch connector body (1), and its outer wall is provided with a first sealing ring (21), forming a first layer of sealing structure with the inner cavity of the welding torch connector body; The first copper core (3) is nested inside the copper valve core (2), and its outer wall is provided with a second sealing ring (31), forming a second sealing structure with the carbon steel core (8) and the inner cavity of the welding torch connector; The second copper core (4) is nested inside the first copper core (3), and its head is provided with a third sealing ring (41); One end of the first spring (5) is supported at the end of the copper valve core (2), and the other end is supported at the end of the first copper core (3); The second spring (6) is mounted on the first copper core (3) and supported at the end of the second copper core (4); The third spring (7) is installed on the outer wall of the second copper core (4) and supported in the inner cavity of the first copper core (3); The first copper core (3) and the copper valve core (2) are connected by a guide structure to prevent axial misalignment.
2. The welding torch anti-return device according to claim 1, characterized in that, The first sealing ring (21) is an annular structure and is set in the sealing groove on the outer wall of the copper valve core (2), forming a radial seal with the inner cavity of the welding gun connector. The second sealing ring (31) forms a bidirectional seal with the carbon steel core (8) and the inner cavity of the welding torch connector.
3. The welding torch anti-return device according to claim 1, characterized in that, The guide structure includes a guide groove (91) on the inner wall of the copper valve core (2) and a guide protrusion (92) on the outer wall of the first copper core (3), which slide together to achieve axial alignment.
4. The welding torch anti-return device according to claim 1, characterized in that, The elastic coefficients of the first spring (5), the second spring (6), and the third spring (7) increase sequentially.
5. The welding torch anti-return device according to claim 1, characterized in that, The third sealing ring (41) at the head of the second copper core (4) is a conical structure, which forms a sealing fit with the conical surface of the inner cavity of the welding gun connector body (1).
6. The welding torch anti-return device according to claim 1, characterized in that, The nested channels of the first copper core (3) and the second copper core (4) form a backflow prevention structure. The inner diameter of the channel gradually decreases along the airflow direction, forming turbulence to suppress the backflow of gas.
7. The welding torch anti-return device according to claim 1, characterized in that, The total axial stroke of the copper valve core (2) and the first copper core (3) is less than 15mm, constituting a short stroke.
8. The welding torch anti-return device according to claim 1, characterized in that, The first sealing ring (21), the second sealing ring (31) and the third sealing ring (41) are made of high-temperature resistant rubber materials with different hardness, wherein the Shore hardness of the first sealing ring (21) is greater than that of the second sealing ring (31).