A pneumatic projection welding lower electrode

Abstract

This utility model discloses a pneumatic projection welding lower electrode, including an electrode base, a lower electrode, and a positioning core. The electrode base has an upward-opening movable groove, and an air inlet communicating with the movable groove is opened on the side of the electrode base. The lower electrode is mounted on the electrode base, and a movable hole is opened through the lower electrode vertically. Several exhaust holes communicating with the movable hole are opened on the side of the lower electrode. The positioning core is movably mounted in the movable hole. By opening exhaust holes on the side of the lower electrode, this utility model ensures that there is a pressure difference between the upper and lower positions of the positioning core before and after the projection welding nut is installed on the upper end of the positioning core, preventing the positioning core from falling off. This ensures that the pneumatic projection welding lower electrode can effectively position the projection welding nut and prevent metal spatter during use. Furthermore, the high-pressure gas is directly discharged from the exhaust holes, preventing the high-pressure gas from breaking through the circumferential weld of the projection welding nut, thereby improving product quality.

Description

Technical Field

[0001] This utility model relates to the field of welding technology, specifically to a pneumatic projection welding lower electrode. Background Technology

[0002] The main purpose of projection weld nuts on automotive panels is to improve assembly efficiency and connection strength. Projection weld nuts are made by pre-punching holes into a metal sheet, then pressing and welding the nut into the holes to achieve the connection. This connection method effectively reduces the need for thread repairs and improves load-bearing capacity and connection accuracy.

[0003] In existing technology, when welding projection nuts onto automotive sheet metal parts, both the sheet metal and the projection nut are mounted on the lower electrode of the welding clamp. A locating core within the lower electrode provides positioning, and then the upper and lower electrodes of the welding clamp work together to complete the welding of the projection nut. However, after a period of use, the upper surface of the lower electrode develops an oxide layer and wear due to welding, requiring periodic grinding. However, because the locating core is spring-loaded within the lower electrode, it must be disassembled before grinding, making the process extremely inconvenient.

[0004] Therefore, to solve the problem of inconvenient grinding of the lower electrode, a pneumatic lower electrode has emerged in the prior art. Please refer to application number 201510437122.1, which discloses a blow-type projection welding nut projection welding lower electrode. By setting a high-pressure air pipe on the electrode seat of the projection welding machine lower electrode, high-pressure gas is introduced into the electrode seat during use. The high-pressure gas pushes out the positioning core to achieve positioning of the plate and projection welding nut, and then welding is performed.

[0005] When automatic grinding of the pneumatic lower electrode disclosed in the aforementioned patent is required, simply controlling the solenoid valve via PLC to stop the supply of high-pressure gas will cause the positioning core to fall, thereby automatically grinding the surface of the lower electrode. However, the pneumatic lower electrode disclosed in the aforementioned patent has the following problems in use:

[0006] Because the locating core and the lower electrode are connected by a movable connection, a gap will inevitably exist between them. After the plate and the blind hole projection weld nut are installed, the high-pressure gas introduced by the lower electrode will enter the projection weld nut, filling the entire cavity with high-pressure gas. This results in no pressure difference between the upper and lower parts of the locating core, causing it to lose its upward force and fall. Consequently, the locating core loses its positioning function for the projection weld nut. Simultaneously, during welding, molten metal is prone to spattering. After the locating core falls, it cannot seal off the spattered metal, allowing it to enter the projection weld nut and cause product defects. Furthermore, since there is no outlet for the high-pressure gas, it will squeeze out the molten metal from the circumferential weld of the projection weld nut, thus affecting the sealing performance of the circumferential weld. Utility Model Content

[0007] To address the aforementioned shortcomings of existing technologies, the purpose of this utility model is to provide a pneumatic projection welding lower electrode, which solves the problem that the high-pressure gas cannot be discharged during use, easily causing the positioning core to fall, thus losing its function of positioning the projection welding nut and blocking metal spatter.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A pneumatic projection welding lower electrode includes an electrode base, a lower electrode, and a positioning core. The electrode base has an upward-opening movable groove, and an air inlet is provided on the side of the electrode base, which communicates with the movable groove. The lower electrode is mounted on the electrode base, and a movable hole is provided through the lower electrode vertically. Several exhaust holes are provided on the side of the lower electrode, which communicate with the movable hole. The positioning core is movably mounted in the movable hole.

[0010] As a further improvement, the upper and lower ends of the positioning core protrude beyond the lower electrode, with the upper end being a positioning part and the lower end being a limiting part, and the limiting part being located within the movable groove.

[0011] As a further improvement, the limiting part is a disc-shaped structure, and the diameter of the limiting part is larger than the diameter of the movable hole but smaller than the inner diameter of the movable groove.

[0012] As a further improvement, four exhaust holes are evenly spaced on the side of the lower electrode.

[0013] As a further improvement, the air inlet is connected to external compressed air via a connector.

[0014] As a further improvement, the diameter of the movable groove is larger than the diameter of the movable hole.

[0015] As a further improvement, the lower electrode is detachably mounted in the movable slot of the electrode holder.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This invention, by creating an exhaust port on the side of the lower electrode, ensures a pressure difference between the upper and lower positions of the positioning core before and after the projection weld nut is installed on the upper end of the positioning core. This prevents the positioning core from falling off, thus ensuring that the pneumatic projection weld lower electrode can effectively position the projection weld nut and prevent metal spatter during use. Furthermore, the high-pressure gas is discharged directly from the exhaust port, preventing it from breaking through the circumferential weld of the projection weld nut, thereby improving product quality. When grinding of the lower electrode is required, automatic grinding can be completed by disconnecting the high-pressure gas, improving the efficiency and quality of the lower electrode repair and grinding. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] In the picture:

[0020] Electrode holder 1, movable groove 1a, air inlet 1b, lower electrode 2, movable hole 2a, exhaust hole 2b, positioning core 3, positioning part 3a, limiting part 3b, plate 100, projection weld nut 200. Detailed Implementation

[0021] To explain in detail the technical content, structural features, objectives and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0022] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "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 utility model 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 utility model.

[0023] Please see Figure 1 A pneumatic projection welding lower electrode includes an electrode base 1, a lower electrode 2, and a positioning core 3. The electrode base 1 has an upward-opening movable groove 1a, and an air inlet 1b on its side communicates with the movable groove 1a. The air inlet 1b is connected to external compressed air via a connector; high-pressure compressed air is used in this invention. The lower electrode 2 is mounted on the electrode base 1, and the lower electrode 2 has a through-hole 2a extending vertically. The positioning core 3 is movably mounted within the through-hole 2a. The lower electrode 2 has several exhaust holes 2b on its side that communicate with the through-hole 2a. When compressed air is introduced through the lower air inlet 1b, it can be discharged through the upper exhaust holes 2b, ensuring that the upper and lower positions of the positioning core 3 maintain a pressure difference and prevent it from falling off.

[0024] Specifically, the upper and lower ends of the positioning core 3 protrude beyond the lower electrode 2, with the upper end being a positioning part 3a for positioning the plate 100 and the projection weld nut 200; the lower end of the positioning core 3 is a limiting part 3b, which is located within the movable groove 1a. In this embodiment, the limiting part 3b has a disc-shaped structure, and its diameter is larger than the diameter of the movable hole 2a but smaller than the inner diameter of the movable groove 1a. Therefore, the limiting part 3b can limit the upward thrust of the positioning core 3 by compressed air, while also increasing the contact area with the compressed air to ensure the upward thrust on the positioning core 3.

[0025] In this embodiment, four exhaust holes 2b are evenly spaced on the side of the lower electrode 2. This is only a preferred embodiment, and the number of exhaust holes 2b is not limited to the above four.

[0026] In this embodiment, the diameter of the movable groove 1a is larger than the diameter of the movable hole 2a.

[0027] In this embodiment, the lower electrode 2 is detachably installed in the movable groove 1a of the electrode seat 1 and can be connected by a thread.

[0028] The working principle of this utility model is as follows:

[0029] When welding the projection nut 200, firstly, high-pressure gas is introduced into the lower electrode. The high-pressure gas enters the movable groove 1a, and under the thrust of the high-pressure gas, the positioning core 3 moves upward, causing its upper positioning part 3a to protrude from the upper surface of the lower electrode 2. At the same time, the high-pressure gas is discharged from the exhaust hole 2b of the lower electrode 2, maintaining a pressure difference between the upper and lower positions of the positioning core 3 and preventing it from falling. Then, the plate 100 is installed on the upper end of the lower electrode 2 and limited by the positioning core 3. Then, the projection nut 200 is installed on the positioning part 3a. After installation, it is used in conjunction with the upper electrode of the welding equipment to perform circumferential welding on the projection nut 200. During welding, because the lower electrode 2 has an exhaust hole 2b, high-pressure gas will not enter the interior of the projection nut 200 above, nor will it break through the circumferential weld from the welding position, thereby improving the welding quality of the product.

[0030] When the surface of the lower electrode is worn and needs to be polished and repaired, the surface of the lower electrode 2 can be polished and repaired simply by controlling the solenoid valve through the PLC to disconnect the high-pressure gas below and the positioning core 3 falling.

[0031] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments disclosed and described above, and some modifications and changes to this utility model should also fall within the protection scope of the claims of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model.

Claims

1. A pneumatic projection welding lower electrode, characterized in that The device includes an electrode base (1), a lower electrode (2), and a positioning core (3). The electrode base (1) has an upward-opening movable groove (1a) and an air inlet (1b) connected to the movable groove (1a) on its side. The lower electrode (2) is mounted on the electrode base (1) and has a movable hole (2a) extending vertically through it. The lower electrode (2) has several exhaust holes (2b) connected to the movable holes (2a) on its side. The positioning core (3) is movably mounted in the movable hole (2a).

2. A gas-actuated projection welding lower electrode as defined in claim 1, characterized in that The upper and lower ends of the positioning core (3) protrude out of the lower electrode (2), with the upper end being the positioning part (3a) and the lower end being the limiting part (3b), and the limiting part (3b) being located in the movable groove (1a).

3. A gas-actuated projection welding lower electrode as defined in claim 2, characterized in that The limiting part (3b) has a disc-shaped structure, and the diameter of the limiting part (3b) is larger than the diameter of the movable hole (2a) and smaller than the inner diameter of the movable groove (1a).

4. A gas-actuated projection welding lower electrode as defined in claim 1, wherein The lower electrode (2) has four vent holes (2b) evenly spaced on its side.

5. A gas-actuated projection welding lower electrode as defined in claim 1, wherein The air inlet (1b) is connected to external compressed air via a connector.

6. The pneumatic projection welding lower electrode as described in claim 1, characterized in that, The diameter of the movable groove (1a) is larger than the diameter of the movable hole (2a).

7. The pneumatic projection welding lower electrode as described in claim 1, characterized in that, The lower electrode (2) is detachably installed in the movable groove (1a) of the electrode seat (1).

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