TWI689364B - Electrode rotation welding device and resistance spot welding equipment using the same - Google Patents

Abstract

An electrode rotation welding device and resistance spot welding equipment using the same, having a first electrode arm and a second electrode arm that can be close to or far from a joint composed of metal welding workpieces, the first electrode arm is provided with a first electrode, and the electrode rotation welding device It further includes an electrode rotation module, which is arranged on the second electrode arm and has a rotating unit and a plurality of second electrodes. The rotating unit can drive a plurality of second electrodes to rotate a second electrode to a working position; An electrode arm and a second electrode arm can be close to each other, so that the first electrode and the second electrode at the working position respectively contact and pressurize the joint surface, and conduct current to the first electrode and the second electrode at the working position to conduct resistance welding.

Description

Electrode rotation welding device and resistance spot welding equipment using the same

The invention relates to a welding device and resistance spot welding equipment, in particular to an electrode rotation welding device and resistance spot welding equipment using these devices.

Resistance Spot Welding (Resistance Spot Welding, RSW) is suitable for assembly welding of automobile body, including assembly welding of frame, floor, side wall, door and body assembly, etc. A large number of resistance spots are used in the assembly welding production process Welding process. According to statistics, there are about 3000~4000 resistance spot welding spots on each car body. In the automobile body assembly welding process, the spot welding process is still in a dominant position. The application of resistance spot welding technology has realized the mass production and automation of automobile body manufacturing.

Please refer to FIGS. 1 and 2A to 2E. After the general metal welding parts (W1, W2) are combined into the joint J, the electrode F (11, 12) at two different positions on the conventional resistance spot welding device 1 applies pressure F to the joint J, and the current is passed through the joint J The resistance heat generated in the contact surface and the adjacent area causes the metal welding pieces (W1, W2) at the joint J to produce molten M, which in turn forms the welding point WN. The method of welding is called resistance welding. Generally, resistance welding can be processed on the joining of aluminum to aluminum and aluminum to steel. However, aluminum alloy is a metal with high welding difficulty. The main reason is that aluminum is different from steel in certain properties, so the impact The properties of aluminum alloy weldability mainly include a dense oxide film on the surface, a thermal conductivity of about 3 to 4 times that of steel, alloy elements are easy to melt and volatilize, molten aluminum is easy to adsorb hydrogen, and aluminum alloy has high strength at high temperatures Low, low specific gravity, thermal expansion coefficient is about twice that of steel. Therefore, in the process of processing aluminum alloy by traditional resistance spot welding, the electrodes of the resistance spot welding equipment are sticky It is particularly obvious that once the electrode is sticky, the machine must be shut down to replace the electrode tip, which will seriously affect the continuous production schedule and cause great losses.

At present, some manufacturers deal with the surface of electrodes that are easy to stick. For example, US 20080078749 A1 patent document, the patent is made of concentric circular ridges or grooves on the electrode end surface to further improve the contact between the electrode end surface and the workpiece. The shape design is also a texture pattern, which can restore the electrode surface very quickly when it is re-trimmed due to electrode sticking for continuous welding operations. However, the shape design is essentially continuous spot welding of the same electrode to the workpiece. Therefore, despite the shape of the electrode end surface, the electrode sticking speed can only be slightly delayed.

The purpose of the present invention is to apply an electrode rotation welding device of an electrode rotation module to continuously change multiple electrodes during the welding process, so as to extend the batch continuous resistance spot welding process (that is, before the electrodes are stuck until they need to be replaced) ) For more solder joint processing. Still another object of the present invention is to provide a resistance spot welding device having an electrode rotation welding device.

To achieve the above-mentioned electrode rotation welding device, the technical means provided by the present invention is an electrode rotation welding device, the structure of which includes: a first electrode, which is electrically coupled to a current that can be opened and closed; and an electrode rotation module , With a rotating unit, the rotating unit is provided with a plurality of electrode holding parts, and each electrode holding part can be rotated to a working position by the driving of the rotating unit; a plurality of second electrode heads are correspondingly provided On each electrode holding portion, and the second electrode head of the electrode holding portion in the working position can be electrically coupled to the current to open and close to form a second electrode; the first electrode arm When approaching the second electrode arm, the first electrode and the second electrode can respectively contact and pressurize the surface of the joint, and then conduct the current of the first and second electrodes to pass the current through the joint, and Generates resistance heat at its contact surface and adjacent areas Welding of the joint.

In one embodiment, the rotating unit includes a turntable pivoted on the first electrode arm with a pivot. The turntable is provided with a plurality of electrode grips radially outward from the center of the pivot. When the turntable rotates at an angle, each electrode grip portion can be rotated to the working position in turn.

In one embodiment, the first electrode and the second electrode are columnar electrodes.

In one embodiment, the first electrode is disposed on the first electrode arm through an electrode holding portion assembled on the first electrode arm, and the first electrode is connected to the current through the electrode holding portion; The second electrode is connected to the current through the electrode grips.

In one embodiment, the electrode grips of the turntable are evenly distributed over the entire circumference.

In one embodiment, the diameter of the electrode end face of the columnar electrode of the second electrode contacting the joint is 4-7 mm, and the error value is within ±10%; the first electrode and the second electrode are in contact And pressurized on the upper and lower surfaces of the joint, and the axis of the columnar electrode of the first electrode and the second electrode is on the axis with the coaxial misalignment less than 0.5mm; the axis of the columnar electrode of the second electrode is The surface of the joint that is in contact and pressurized remains vertical, and the angle between its inclination angle and the vertical line does not exceed 5 degrees.

In order to achieve the purpose of the above-mentioned resistance spot welding equipment, the technical means provided by the present invention is a resistance spot welding equipment including the foregoing electrode rotation welding device.

The characteristic of this creation is that this creation framework is based on the traditional resistance spot welding device. Only the electrode part is changed to form an electrode rotation module. Compared with the current solution to solve lightweight metal bonding, it can provide both in terms of volume and mechanism. Simpler design reduces equipment investment The cost achieves the same benefits as the effect; this creation uses an electrode rotation module to overcome the problem of delaying the electrode adhesion during the aluminum alloy welding process, increasing the number of welds that can be completed in a fixed cycle during the welding process, helping to shorten The frequency of resistance spot welding equipment replacement or cleaning electrode sticking, resistance welding saves development time and cost, the average time during the process of construction is 2~3 seconds/point, and the joining speed is fast. If it is combined with an automated production line, it can be reduced In addition to operating labor costs, it can also significantly increase production capacity.

1: Conventional resistance spot welding equipment

11,12: electrode

2: Resistance spot welding equipment

21: electrode rotation welding device

211: First electrode

2111: electrode grip

212: Electrode rotation module

2121: Rotating unit

21211: Turntable

21212: Pivot

2122: Second electrode

2123: working position

2124: Electrode grip

3: Metal welding workpiece group

A1: First electrode arm

A2: Second electrode arm

D: diameter

E: current

F: pressure

I: tilt angle

M: melting

J: connector

O: distance

W1, W2: metal welding parts

WN: solder joint

X1: first electrode axis

X2, X2’: second electrode axis

1 is a schematic side view of a resistance welding device of the prior art; FIGS. 2A~2E are a resistance welding process of the prior art; FIG. 3 is a schematic side view of a resistance welding device with an electrode rotation welding device according to an embodiment of the invention; Front view schematic diagram of an electrode rotation welding apparatus according to an embodiment of the invention; FIG. 5 is a schematic diagram of a coaxial offset range of a second electrode and a first electrode of an electrode rotation welding apparatus according to an embodiment of the invention; FIG. 6 is an electrode rotation welding apparatus according to an embodiment of the invention FIG. 7 is a schematic diagram of the inclination angle range of the second electrode of the welding device and the surface of the joint; FIG. 7 is a schematic diagram of the range of the contact area of the second electrode and the surface of the joint of the electrode rotation welding device according to an embodiment of the invention.

The following describes the embodiments of the present invention in detail with reference to the drawings. The drawings are mainly simplified schematic diagrams, and only the basic structure of the present invention is illustrated in a schematic manner. Therefore, in these drawings Only the elements related to the present invention are indicated in the figure, and the elements shown are not drawn with the number, shape, size ratio, etc. at the time of implementation. The actual specifications are actually a selective design and the layout of the elements It may be more complicated.

First please refer to Figure 3 and Figure 4. The electrode rotation welding device 21 in the embodiments of FIGS. 3 and 4 can be applied to the resistance spot welding apparatus 2. The electrode rotation welding device 21 has a first that can be approached and separated from the joint J of the metal welding workpiece group 3 to be joined An electrode arm A1 and a second electrode arm A2, the first electrode A1 is provided with a first electrode 211, which is electrically coupled to a current E (the first electrode 211 can be assembled to the first electrode arm An electrode holding portion 2111 of A1 is disposed on the first electrode arm A1 for easy replacement), and the metal welding workpiece group 3 is composed of at least two metal welding workpieces (W1, W2). The electrode rotation welding device 21 includes an electrode rotation module 212 which is disposed on the second electrode arm A2 and has a rotation unit 2121 and a plurality of second electrodes 2122. The rotation unit 2121 can drive the plurality of second electrodes Electrode 2122 to rotate a second electrode 2122 to a working position 2123; the first electrode arm A1 and the second electrode arm A2 can be close to each other, so that the first electrode 211 and the second electrode at the working position 2123 The electrodes 2122 contact and pressurize the surface of the joint J, respectively.

4 again, the rotating unit 2121 of the above embodiment may include a turntable 21211, the turntable 21211 is pivotally mounted on the second electrode arm A2 with a pivot 21212, and radiates outward from the center of the pivot 21212 A plurality of electrode grips 2124 for fixing the second electrodes 2122 are provided to facilitate the removal and replacement of the second electrodes 2122.

According to the above-mentioned components, when the first electrode arm A1 and the second electrode arm A2 are close to each other, the first electrode 211 and the second electrode 2122 at the working position 2123 can respectively contact and pressurize at the joint J Surface, and then the first electrode 211 is connected to the working position 2123 After the current of the second electrode 2122 is passed, the current E is passed through the joint J, and resistance heat is generated on the contact surface and the adjacent area. After the joint J of the two metal weldments (W1, W2) forms a solder joint, the The first electrode arm A1 and the second electrode arm A2 are away from each other, and the turntable 21211 is rotated by the rotating unit 2121, so that the second electrode 2122 on the next turntable 21211 enters the working position 2123 for the next welding Spot welding operation.

3 and 4 again, in one embodiment, the rotating unit 2121 includes a turntable 21211, the turntable 21211 is pivoted on the second electrode arm A2 with a pivot 21212, and the pivot 21212 A plurality of second electrodes 2122 are arranged radially outward from the center. When the turntable 21211 rotates by a specific angle (the specific angle corresponds to the angle between the two second electrodes on the turntable 21211), Each electrode grip 2124 turns to the working position 2123 in turn, and performs spot welding. In one embodiment, the second electrodes 2122 of the turntable 21211 are distributed at an equal angle over the entire circumference of the turntable 21211.

Of course, the above-mentioned driving structure for turning the turntable 21211 to rotate at a specific angle can be applied to mechanisms designed in the technical field of the present invention, such as gear sets and servo motor sets, which will not be repeated here.

In an embodiment, the first electrode 211 and the second electrodes 2122 described above are preferably columnar electrodes, but not limited thereto.

In one embodiment, the second electrode 2122 is connected to the current E through the electrode holding portions 2124.

As shown in FIG. 5, in one embodiment, the diameter D of the electrode end surface of the columnar electrode of the second electrode 2122 contacting the joint J (lap joint made of metal weldments W1, W2) is 4-7 mm , And the error value is within ±10%.

As shown in FIG. 6, in one embodiment, the first electrode 211 and the second electrode 2122 located at the working position 2123 are in contact with each other and pressurized at the joint J (made of metal welding parts W1, W2 The different positions (such as upper and lower surfaces) of the joint J), and the first seismic pole axis X1 and the second electrode axis X2 are coaxially displaced within a distance of less than 0.5 mm.

As shown in FIG. 7, in one embodiment, the surface of the joint J (lap joint composed of metal weldments W1, W2) that the second electrode axis X2 contacts and presses remains vertical or inclined The inclination angle I of the second electrode axis X2 and the vertical line does not exceed the range of 5 degrees.

In addition, as shown in FIG. 3, another embodiment of the present invention is a resistance spot welding apparatus 2 including the aforementioned electrode replacement welding device 21.

The above-mentioned embodiments only exemplarily illustrate the principles, characteristics and effects of the present invention, and are not intended to limit the scope of the invention. Anyone who is familiar with this skill can do the above without departing from the spirit and scope of the present invention. The embodiment is modified and changed. Any equivalent changes and modifications made using the disclosure of the present invention should still be covered by the following patent applications. Therefore, the scope of protection of the rights of the present invention should be as listed in the scope of patent application.

21: electrode rotation welding device

211: First electrode

212: Electrode rotation module

2121: Rotating unit

21211: Turntable

21212: Pivot

2122: Second electrode

2123: working position

2124: Electrode grip

3: Metal welding workpiece group

E: current

J: connector

W1, W2: metal welding parts

Claims (10)

An electrode rotation welding device having a first electrode arm and a second electrode arm that can be close to or far from a joint composed of at least two metal welding workpieces, the first electrode arm is provided with a first electrode, and its special feature is: an electrode rotation die The group is arranged on the second electrode arm and has a rotating unit and a plurality of second electrodes. The rotating unit can drive the plurality of second electrodes to rotate a second electrode to a working position; the first The electrode arm and the second electrode arm can be close to each other, so that the first electrode and the second electrode located at the working position respectively contact and pressurize the surface located at the joint, and then the first electrode and the electrode located at the working position are conducted After the current of the second electrode, the current is passed through the joint, and resistance heat is generated on the contact surface and the adjacent area. After the joints of the two metal weldments form a solder joint, the first electrode arm and the second electrode arm interact Move away, and rotate the turntable with the turning unit, so that the second electrode on the next turntable enters the working position to perform the spot welding operation of the next welding spot. The electrode rotation welding device as described in item 1 of the patent application scope, wherein the rotating unit includes a turntable pivoted to the second electrode arm with a pivot, and radially outward with the pivot center A plurality of electrode grips for fixing the second electrodes are provided. The electrode rotation welding device as described in item 1 of the patent application scope, wherein the first electrode and the second electrodes are columnar electrodes. The electrode rotation welding device as described in item 1 of the patent application range, wherein the first electrode is provided on the first electrode arm through an electrode grip portion assembled on the first electrode arm. The electrode rotation welding device as described in item 2 of the patent application range, wherein the second electrodes are connected to the current through the electrode grips. The electrode rotation welding device as described in item 2 of the scope of the patent application, wherein the second electrodes of the turntable are evenly distributed over the entire circumference. The electrode rotation welding device as described in item 1 of the patent application scope, wherein the diameter of the electrode end face of the columnar electrodes of the second electrodes contacting the joint is 4 to 7 mm. The electrode rotation welding device as described in item 3 of the patent application scope, wherein the first electrode and the second electrode located at the working position respectively contact and pressurize the surfaces located at different positions of the joint, and the first The central axis of an electrode and the central axis of the second electrode at the working position are coaxially displaced within a distance of less than 0.5 mm. The electrode rotation welding device as described in item 3 of the patent application scope, wherein the surface of the joint where the central axis of the columnar electrode of the second electrode at the working position is in contact with and pressurized is perpendicular to the inclination angle and perpendicular The line angle does not exceed the range of 5 degrees. A resistance spot welding device comprising: the resistance spot welding device of the electrode rotation welding device as described in item 1 of the patent application scope.

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