A projection welding machine electrode structure with a splash guard

Abstract

This invention discloses an anti-splatter design electrode structure for projection welding machines, comprising: a lower electrode, which includes a lower electrode seat, a lower electrode cover, a positioning pin, and a spring; the lower electrode cover is fixedly installed on the top of the lower electrode seat, and the top of the positioning pin passes through the lower electrode cover, the workpiece to be welded, and the nut sequentially from bottom to top; and an upper electrode, which includes an upper electrode seat, an upper electrode cover, and a protective cover; the upper electrode cover is fixedly installed at the end of the upper electrode seat, the upper electrode seat is provided with an air inlet, the bottom surface of the upper electrode cover is provided with an air outlet, and an air supply channel is provided inside the upper electrode, one end of the air supply channel being connected to the air inlet and the other end being connected to the air outlet; the protective cover includes a corrugated section and a tubular section arranged sequentially from top to bottom, the corrugated section being fixedly installed on the upper electrode seat, and the tubular section contacting the surface of the workpiece to be welded. Compared with the prior art, this invention solves the problem of slag spatter during projection welding of metal nuts on automotive sheet metal.

Description

Technical Field

[0001] This invention relates to the field of projection welding technology for metal nuts, and more particularly to an anti-spatter design electrode structure for projection welding machines. Background Technology

[0002] Projection welding of metal nuts typically employs high-specification welding, welding the nut to a thin metal sheet. During the welding process, the pre-formed projection of the nut is pressurized by a projection welding machine, ensuring close contact between the projection and the workpiece surface. When energized, the current concentrates at the projection; due to the small contact area, the current density and pressure are high, rapidly heating the projection to a molten or plastic state. The projection is crushed under pressure, the two workpieces adhere together, forming a weld nugget. After the power is cut off, it cools and crystallizes under pressure, achieving a strong connection.

[0003] During the projection welding process of metal nuts, the metal melts rapidly after being energized, the local solid metal turns into liquid metal, and the volume expands rapidly (increases internal pressure). The external pressure applied by the projection welding machine causes the liquid metal to be sprayed out of the projection welding position, forming spatter. The liquid spatter forms welding slag on the surface of the nut. Some of the welding slag splashes onto the surface of the inner thread of the projection welded nut and combines with the nut, resulting in poor thread passability of the nut.

[0004] To achieve lightweighting and improved corrosion resistance, new energy vehicles extensively use high-strength steel plates, high-strength galvanized steel plates, and hot-formed steel plates. The welding time for high-strength projection welding of nuts is getting shorter and shorter. In addition, the influence of the galvanized layer and the hot-formed oxide layer exacerbates the welding spatter. The secondary defects and rework caused by spatter are increasing, requiring a lot of manpower for wire cleaning after welding.

[0005] Welding spatter generated during projection welding of metal nuts is mainly divided into internal spatter and external spatter. The existing method for preventing welding spatter in projection welding machines is to add air blowing to the lower electrode. Because the gas is blown from the bottom up in this structure, it can effectively reduce external spatter caused by the combination of weld slag and the outer surface of the nut. However, the weld slag being blown outward increases the risk of it splashing onto the operator's body. At the same time, it is easy to blow the weld slag towards the inner thread surface of the nut, forming internal spatter. It is also easy for the weld slag to combine with the upper electrode, and the weld slag accumulates on the surface of the upper electrode, which requires the upper electrode to be cleaned of weld slag regularly. Otherwise, it will lead to poor welding of the nut. Summary of the Invention

[0006] The purpose of this invention is to provide an anti-splatter design electrode structure for projection welding machines to solve the problem of slag spatter during projection welding of metal nuts on automotive sheet metal.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an anti-spatter design electrode structure for projection welding machines, comprising:

[0008] The lower electrode includes a lower electrode base, a lower electrode cover, a positioning pin, and a spring. The lower electrode cover is fixedly installed on the top of the lower electrode base. The positioning pin is placed in the cavity of the lower electrode base. One end of the spring contacts the positioning pin, and the other end contacts the bottom surface of the cavity. The top of the positioning pin passes through the lower electrode cover, the welding workpiece, and the nut from bottom to top.

[0009] The upper electrode includes an upper electrode base, an upper electrode cover, and a protective cover. The upper electrode cover is fixedly installed at the end of the upper electrode base. An air inlet is provided on the upper electrode base, and an air outlet is provided on the bottom surface of the upper electrode cover. An air supply channel is provided inside the upper electrode. One end of the air supply channel is connected to the air inlet, and the other end is connected to the air outlet. The protective cover includes a corrugated section and a tube section arranged sequentially from top to bottom. The corrugated section is fixedly installed on the upper electrode base, and the tube section contacts the surface of the workpiece to be welded.

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

[0011] The bottom of the pipe section is bonded and fixed to the annular insulating plate, which contacts the surface of the welded workpiece. Several photoelectric sensors are arranged circumferentially on the outside of the annular insulating plate, with the detection direction of the photoelectric sensors facing the surface of the welded workpiece.

[0012] As a further description of the above technical solution:

[0013] The photoelectric sensor is fixedly mounted on the mounting plate, which is detachably mounted on the annular insulating plate.

[0014] As a further description of the above technical solution:

[0015] The mounting plate is fixedly mounted on the plug rod. On the plug rod on the lower side of the mounting plate, there are regular polygonal plug blocks and a first magnet arranged sequentially from top to bottom. The first magnet is fixedly mounted on the regular polygonal plug blocks. The annular insulating plate is provided with a slot that matches the shape of the regular polygonal plug blocks. The bottom surface of the slot is provided with a blind hole that matches the shape of the plug rod. The second magnet is fixedly mounted on the bottom surface of the slot. When the plug rod passes through the second magnet and is inserted into the blind hole, the first magnet and the second magnet are magnetically attracted and fixed.

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

[0017] The ring-shaped insulating plate also has a notch that matches the shape of the photoelectric sensor.

[0018] As a further description of the above technical solution:

[0019] The corrugated section is fixedly mounted to the upper electrode holder by at least one screw.

[0020] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0021] 1. In this invention, during the welding process, the airflow is introduced into the upper electrode through the air inlet and blown towards the positioning pin through the air outlet at the bottom of the upper electrode cover. The airflow is guided through the conical top and the inclined side wall of the positioning pin and blown out to the outside of the nut at the joint gap between the welded workpiece and the nut. This avoids the slag from splashing onto the nut thread surface when high-strength steel plates, high-strength galvanized steel plates and hot-formed steel plates are used for projection welding of nuts, thus reducing the need for manual secondary wire cleaning.

[0022] 2. In this invention, since the protective cover shields the welding point and the protective cover maintains a close fit to the welding workpiece through the expansion and contraction of the corrugated section, it can effectively shield the welding slag from splashing outwards, thus avoiding burns to the operator's skin or eyes.

[0023] 3. In this invention, the annular insulating plate at the bottom of the protective cover serves as a counterweight structure to keep the protective cover hanging, thereby ensuring that the bottom of the protective cover fits the plate. On the other hand, the high mechanical strength and dimensional stability of the annular insulating plate are utilized to detect multiple points on the surface of the welded workpiece using photoelectric sensors, thereby determining whether the surface of the welded workpiece is flat before welding and whether it is deformed after welding. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of an electrode structure for a projection welding machine with anti-splash design.

[0026] Figure 2 This is a schematic diagram of the protective cover in the electrode structure of a projection welding machine designed to prevent spatter.

[0027] Figure 3 This is a cross-sectional view of a protective cover in the electrode structure of a projection welding machine designed to prevent spatter.

[0028] Figure 4 for Figure 3 A magnified view of a portion of point A in the middle.

[0029] Figure 5 This is a schematic diagram illustrating the state changes of the protective cover in the electrode structure of a projection welding machine with an anti-splash design.

[0030] Figure 6 This is a schematic diagram of the installation of a photoelectric sensor in the electrode structure of a projection welding machine with an anti-splash design.

[0031] Legend:

[0032] 1. Lower electrode; 11. Lower electrode holder; 12. Lower electrode cover; 13. Positioning pin; 14. Spring;

[0033] 2. Upper electrode; 21. Upper electrode holder; 211. Air inlet; 22. Upper electrode cover; 23. Protective cover; 231. Corrugated section; 232. Pipe section; 233. Screw;

[0034] 3. Annular insulating plate; 31. Slot; 32. Second magnet;

[0035] 4. Photoelectric sensor; 41. Mounting plate; 42. Connecting rod; 43. Regular polygonal connector; 44. First magnet;

[0036] 9. Welded workpiece; 91. Nut. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0039] Example 1

[0040] Please see Figure 1-6 This invention provides a technical solution: an anti-spatter design electrode structure for projection welding machines, comprising:

[0041] The lower electrode 1 includes a lower electrode seat 11, a lower electrode cover 12, a positioning pin 13, and a spring 14. The lower electrode cover 12 is fixedly installed on the top of the lower electrode seat 11. The positioning pin 13 is placed in the cavity of the lower electrode seat 11. One end of the spring 14 contacts the positioning pin 13, and the other end contacts the bottom surface of the cavity. The top end of the positioning pin 13 passes through the lower electrode cover 12, the welding workpiece 9, and the nut 91 from bottom to top.

[0042] The upper electrode 2 includes an upper electrode base 21, an upper electrode cover 22, and a protective cover 23. The upper electrode cover 22 is fixedly installed at the end of the upper electrode base 21. An air inlet 211 is provided on the upper electrode base 21, and an air outlet is provided on the bottom surface of the upper electrode cover 22. An air supply channel is provided inside the upper electrode 2. One end of the air supply channel is connected to the air inlet 211, and the other end is connected to the air outlet. The protective cover 23 includes a corrugated section 231 and a tube section 232 arranged sequentially from top to bottom. The corrugated section 231 is fixedly installed on the upper electrode base 21, and the tube section 232 contacts the surface of the welding workpiece 9.

[0043] The corrugated section 231 is fixed to the upper electrode seat 21 by a plurality of screws 233 arranged circumferentially along the upper electrode seat 21, and preferably there are 3 screws 233, so that the protective cover 23 is easy to disassemble and maintain.

[0044] The protective cover 23 is preferably made of transparent silicone to facilitate observation of the welding process on the inside.

[0045] In addition, the upper electrode cover 22 is a tungsten copper alloy cover. The lower electrode seat 11 and lower electrode cover 12 of the lower electrode 1 and the upper electrode seat 21 of the upper electrode 2 are all made of chromium zirconium copper, while the upper electrode cover 22 is made of a harder tungsten copper alloy instead of chromium zirconium copper, which improves the service life of the upper electrode cover 22 and reduces the cost of electrode replacement.

[0046] Working principle: When the projection welding machine performs projection welding on metal nuts, the nut 91 and the workpiece 9 are clamped between the lower electrode 1 and the upper electrode 2. The upper electrode cover 22 contacts the nut 91, and the lower electrode cover 12 contacts the workpiece 9. At the same time, the positioning pin 13 passes through the lower electrode cover 12, the workpiece 9, and the nut 91 from bottom to top, and the protective cover 23 covers the nut 91. During the welding process, the airflow enters the upper electrode 2 through the air inlet 211 and is blown towards the positioning pin 13 through the air outlet at the bottom of the upper electrode cover 22. The airflow is guided by the conical top and the inclined side wall of the positioning pin 13 to the joint gap between the workpiece 9 and the nut 91 and blown outward from the nut 91. This prevents the slag from splashing onto the nut thread surface when projection welding high-strength steel plates, high-strength galvanized steel plates, and hot-formed steel plates used in automobiles, reducing the need for manual secondary wire cleaning. Meanwhile, since the protective cover 23 shields the welding point and the protective cover 23 keeps in close contact with the welding workpiece 9 through the expansion and contraction of the corrugated section 231, it can effectively shield the welding slag from splashing outwards, avoiding burns to the operator's skin or eyes.

[0047] Example 2

[0048] Based on the above embodiments, this embodiment further improves upon the following technical solution: the bottom of the tube section 232 is bonded and fixed to the annular insulating plate 3, the annular insulating plate 3 contacts the surface of the welding workpiece 9, and a plurality of photoelectric sensors 4 are arranged circumferentially on the outer side of the annular insulating plate 3, with the detection direction of the photoelectric sensors 4 facing the surface of the welding workpiece 9.

[0049] The annular insulating plate 3 can be made of FR4 insulating plate and is bonded and fixed to the tube section 232 with adhesive. The annular insulating plate 3 serves as a counterweight structure to keep the protective cover hanging, thereby ensuring that the bottom of the protective cover is in contact with the plate. On the other hand, the high mechanical strength and dimensional stability of the annular insulating plate 3 are utilized to detect multiple points on the surface of the welding workpiece 9 through the photoelectric sensor 4 to determine whether the surface of the welding workpiece 9 is flat before welding and whether it is deformed after welding.

[0050] Example 3

[0051] This embodiment further improves upon the above embodiment by making the following technical solution: the photoelectric sensor 4 is fixedly mounted on the mounting plate 41, and the mounting plate 41 is detachably mounted on the annular insulating plate 3. Specifically, the mounting plate 41 is fixedly mounted on the plug-in rod 42. The plug-in rod 42 on the lower side of the mounting plate 41 is provided with a regular polygonal plug-in block 43 and a first magnet 44 arranged sequentially from top to bottom. The first magnet 44 is fixedly mounted on the regular polygonal plug-in block 43. The annular insulating plate 3 is provided with a slot 31 whose shape matches the regular polygonal plug-in block 43. The bottom surface of the slot 31 is provided with a blind hole whose shape matches the plug-in rod 42. The second magnet 32 ​​is fixedly mounted on the bottom surface of the slot 31. When the plug-in rod 42 passes through the second magnet 32 ​​and is inserted into the blind hole, the first magnet 44 and the second magnet 32 ​​are magnetically attracted and fixed.

[0052] On one hand, the photoelectric sensor 4 on the mounting plate 41 is connected to the annular insulating plate 3 via the plug-in rod 42 and the magnetic attraction of the first magnet 44, enabling quick-release installation and facilitating disassembly and maintenance. On the other hand, the insertion of the regular polygonal plug-in block 43 on the back of the mounting plate 41 into the slot 31 on the annular insulating plate 3 allows the mounting plate 41 and the photoelectric sensor 4 on it to rotate and adjust their position. This allows the photoelectric sensor 4 to avoid being misaligned in special cases such as when there are through holes on the surface of the welded workpiece 9. At the same time, the insertion of the regular polygonal plug-in block 43 into the slot 31 effectively prevents the mounting plate 41 from rotating, and the adjustment of the number of sidewalls of the regular polygonal plug-in block 43 improves the flexibility of angle adjustment and misalignment. The plug-in rod 42 not only facilitates the rotation of the mounting plate 41 but also facilitates insertion and removal, further facilitating disassembly and maintenance.

[0053] Preferably, a notch 33 matching the shape of the photoelectric sensor 4 is provided on the annular insulating plate 3. The photoelectric sensor 4 is positioned by the annular insulating plate 3 to prevent the photoelectric sensor 4 from tilting and to improve the accuracy of the detection results.

[0054] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A projection welder electrode structure of splash-proof design, characterized by include: The lower electrode includes a lower electrode base, a lower electrode cover, a positioning pin, and a spring. The lower electrode cover is fixedly installed on the top of the lower electrode base. The positioning pin is placed in the cavity of the lower electrode base. One end of the spring contacts the positioning pin, and the other end contacts the bottom surface of the cavity. The top end of the positioning pin passes through the lower electrode cover, the welding workpiece, and the nut from bottom to top. The upper electrode includes an upper electrode base, an upper electrode cover, and a protective cover. The upper electrode cover is fixedly installed at the end of the upper electrode base. The upper electrode base is provided with an air inlet, and the bottom surface of the upper electrode cover is provided with an air outlet. An air supply channel is provided inside the upper electrode. One end of the air supply channel is connected to the air inlet, and the other end is connected to the air outlet. The protective cover includes a corrugated section and a tube section arranged sequentially from top to bottom. The corrugated section is fixedly installed on the upper electrode base, and the tube section contacts the surface of the workpiece to be welded.

2. The anti-spatter design projection welding machine electrode structure according to claim 1, characterized in that, The bottom of the tube section is bonded and fixed to the annular insulating plate, which contacts the surface of the welded workpiece. Several photoelectric sensors are arranged circumferentially on the outside of the annular insulating plate, and the detection direction of the photoelectric sensors is towards the surface of the welded workpiece.

3. The anti-spatter design projection welding machine electrode structure according to claim 2, characterized in that, The photoelectric sensor is fixedly mounted on the mounting plate, and the mounting plate is detachably mounted on the annular insulating plate.

4. The anti-spatter design projection welding machine electrode structure according to claim 3, characterized in that, The mounting plate is fixedly mounted on the plug rod. On the plug rod on the lower side of the mounting plate, there are regular polygonal plug blocks and a first magnet arranged sequentially from top to bottom. The first magnet is fixedly mounted on the regular polygonal plug blocks. The annular insulating plate is provided with a slot whose shape matches the regular polygonal plug blocks. The bottom surface of the slot is provided with a blind hole whose shape matches the plug rod. The second magnet is fixedly mounted on the bottom surface of the slot. When the plug rod passes through the second magnet and is inserted into the blind hole, the first magnet and the second magnet are magnetically attracted and fixed together.

5. The anti-spatter design projection welding machine electrode structure according to claim 2, characterized in that, The annular insulating plate is also provided with a notch whose shape matches that of the photoelectric sensor.

6. The anti-spatter design projection welding machine electrode structure according to claim 1, characterized in that, The corrugated section is fixedly mounted to the upper electrode holder by at least one screw.

7. The anti-spatter design projection welding machine electrode structure according to claim 1, characterized in that, The protective cover is a transparent silicone cover.

8. The anti-spatter design projection welding machine electrode structure according to claim 1, characterized in that, The upper electrode cover is a tungsten-copper alloy cover.

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