JP2020040080A - Electrode position adjustment mechanism of spot welder - Google Patents

Abstract

To provide a mechanism which can perform positional adjustment of at least one electrode of a spot welder easily, manually and freely.SOLUTION: A holder for holding at least one electrode of a spot welder has: a first holder which stores an electrode, and is rotatable around a first rotary shaft; and a second holder which rotatably holds the first holder, and comprises a second rotary shaft. The first rotary shaft is located at a position separated from a tip of the electrode, and the second rotary shaft is located at a position separated from the first rotary shaft. By rotation of the first holder and the second holder, an electrode tip position can be adjusted in a prescribed range.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electrode position adjusting mechanism of a spot welder. More particularly, it relates to a mechanism for manually adjusting the position of at least one electrode of a spot welder.

Resistance welding is a method in which an electric current is applied to a portion to be welded of a work to be welded (work), and the work is fused by Joule heat and pressure to form a molten metal, which is solidified and joined. In a typical example of spot welding, a work to be welded is sandwiched between a pair of electrodes, a large current of several thousand to tens of thousands of amperes is applied while pressurizing, and a nugget is formed, fused and joined. In general, one of the pair of electrodes is configured as a fixed electrode and one as a movable electrode. And, by being mounted on an industrial robot or the like, it can respond to various hit points.

However, if the use of the welding machine is continued, not only the wear of the electrodes but also the loosening, wear, and wear of the fixing elements of the machine may cause the position of the electrodes to be different from the initial position or the ideal position. For this reason, the tip positions of the upper and lower electrodes, which should originally match, may not be sufficiently engaged, and welding may be impossible or defective. Further, when the spot welding machine is delivered, a slight positional shift may occur in the assembly.

At present, fine position adjustment is performed by reassembling the machine to solve the above problem, but the load is large in terms of time and work. Further, for example, as in Patent Document 1, a mechanism for adjusting the electrode position on the robot side when using a welding machine is known, but these have electrodes at the initially assumed position and must be adjusted during use. The above operation is not required when the predetermined position is shifted by use.

JP 2011-156564 A

Accordingly, an object of the present invention is to provide a mechanism that can easily, manually, and freely adjust the position of at least one electrode of a spot welding machine.

In order to solve the above problems, in the electrode position adjusting mechanism of the spot welding machine according to the present invention, a holder for holding at least one electrode of the spot welding machine houses the electrode, and rotates around the first rotation axis. A second holder having a first holder and a second axis of rotation that rotatably holds the first holder, wherein the first axis of rotation is the tip of the electrode; The second rotation axis is located at a distance from the first rotation axis, and the tip of the electrode tip can be adjusted within a predetermined range by rotation of the first holder and the second holder. It consists of something.

The first holder has a first rotation axis at its center, and has a first portion rotatably held by the second holder, and a second portion holding the electrode, Preferably, the diameter of the second part is larger than that of the first part, and the center axis of the second part is located at a position separated from the first rotation axis.
In the first holder, it is preferable that the first portion is tapered and the second portion holds the straight shank.
Preferably, the second holder has a cylindrical shape, and the first rotation axis and the second rotation axis are parallel.
Further, it is preferable that the distance between the first rotation axis and the second rotation axis is equal to the distance between the first rotation axis and the rotation axis of the electrode.
Further, it is preferable that the central axis of the second portion of the first holder coincides with the central axis of the electrode.
Further, it is preferable to provide a tightenable member that fixes the position of the first holder or the second holder.

In the present invention, a generally fixed cylindrical electrode holder is constituted by two rotatable holders, preferably having parallel rotation axes separated from each other, and both rotation axes being separated from the electrode tip. Is provided. With this configuration, the position of the electrode tip can be adjusted within a certain circular range by the two eccentric shafts. In the present application, a holder connected to the gun body is referred to as a second holder, and a holder connected to the second holder and holding an electrode is referred to as a first holder. The first holder may be configured as a replaceable electrode adapter that adjusts the length to the electrode.

When the second holder, which is typically cylindrical, is rotated, the first holder and the electrode rotate simultaneously about the second rotation axis. At this time, since the rotation axis of the first holder is at an eccentric position separated by a distance A from the second rotation axis of the second holder, the first rotation axis of the first holder is in the second rotation axis. Move along a circular locus of radius A about the axis. Further, when the first holder is rotated, the tip position of the electrode tip is at an eccentric position separated by a distance B from the first rotation axis, so that the tip position of the electrode tip is centered on the first rotation axis. A circular locus having a radius B is moved.

Therefore, the tip position of the electrode tip can be adjusted at a desired position within a circle of radius A + B around the second rotation axis by rotating the first holder and the second holder. It is. The structure for rotation is not particularly limited as long as it can be rotated and fixed, and a bearing, a groove mechanism, a fastener, or the like may be used.

According to this configuration, it is possible to easily adjust the electrode position by manually rotating the first holder and the second holder. If the distance A and the distance B are the same, the electrode tip position can pass through the second rotation axis position regardless of the position of the first rotation axis, so that adjustment and assumption are easy. is there. Further, after adjusting the electrode position, the position of each holder can be fixed by a member that can be tightened or loosened, such as a screw or a bolt, so that positional deviation can be prevented.

Further, the first holder is rotatably held by the second holder, but in order to more easily realize the above-described configuration, the first holder has a first rotation axis as a center. , A first portion rotatably held by the second holder, and a second portion holding the electrode, wherein the diameter of the second portion is larger than the first portion and the center of the second portion. Preferably, the axis is at a different position from the first axis of rotation. That is, the first portion is preferably tapered and rotatably held in the second holder. The second portion is preferably cylindrical and holds the electrode (shank) inside. The center axis of the electrode (typically, a straight shank) and the tip of the electrode coincide with the center axis of the cylindrical portion of the second portion. These configurations are effective in facilitating electrode holding and position adjustment while separating the first rotating shaft from the electrode tip.

Other configurations of the spot welding machine, that is, the arms, the pressurizing cylinders, the piston rods, and the like are not different from known configurations. Also, there is no difference between the electrode and the cooling water passage provided inside the holder as in a known welding machine, and a known electrode can be used for the electrode. In addition, as long as the effects of the present invention are exhibited, such as providing another rotation shaft in the holder, the present invention can be realized in various forms.

ADVANTAGE OF THE INVENTION According to the structure of this invention, although it is a simple and economically efficient structure, maintenance is also easy and adjustment to a desired position can be easily, manually, and freely performed.

It is a figure showing one example of an embodiment of the present invention. FIG. 2 is a side view of a second holder side of the embodiment in FIG. 1. FIG. 2 is a side view on the electrode side of the embodiment of FIG. 1. FIG. 3 is a diagram illustrating a trajectory of a first rotation axis and a movable range of an electrode tip position.

One embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a view showing an electrode position adjusting mechanism 1 of the present invention. The electrode position adjusting mechanism 1 of the present invention is typically provided on the upper movable electrode, but may be provided on both sides or on the lower electrode. In this embodiment, it is provided on the upper arm 2. The description of the pressurized cylinder, piston rod, etc. is omitted.

The electrode 3 includes a straight shank 4 and an electrode tip 5 provided at the tip of the straight shank 4. The electrode tip 5 comes into contact with the workpiece at the tip end position 6. The straight shank 4 is cylindrical, has a shaft 7 as a center axis, and has a tip position 6 of the electrode tip 5 on the shaft 7 (on an extension). Further, a water passage 8 for cooling is provided in the straight shank 4 to allow the electrode tip 5 to be cooled. The straight shank 4 and the electrode tip 5 are not different from known configurations.

A first holder 9 is provided for holding the electrode 3. The first holder 9 includes a tapered first portion 11 held in a second holder 10 and a second portion 12 holding an electrode. The first part 11 is rotatably held in the second holder 10 with the center axis of the first part 11 as a rotation axis 13. The second part has a larger diameter than the first part, and its central axis coincides with the central axis 7 of the straight shank. Therefore, as shown in FIG. 3, when the first holder 9 is rotated, the first holder 9 rotates about the rotation shaft 13. However, the rotation shaft 13 and the center shaft 7 of the straight shank are parallel and separated by a distance B. Therefore, the electrode tip position 6 moves on a trajectory C on a circle having a radius B around the rotation axis 13.

The second holder 10 has a cylindrical shape, is rotatable about a rotation shaft 14, and has a storage portion 15 for the first holder 9. However, the storage portion 15 having the tapered receiving portion is provided with the center axis eccentric with respect to the rotation shaft 14. Then, the central axis of the storage section 15 coincides with the rotation axis 13. However, the rotating shaft 14 is parallel to the rotating shaft 13 but separated by a distance A. Accordingly, as shown in FIG. 4, when the second holder 10 is rotated, the second holder 10 rotates about the rotation shaft 14. However, since the rotation shaft 14 and the rotation shaft 13 are parallel and separated by the distance A, The first holder rotating shaft 13 moves on a trajectory D on a circle having a radius A around the rotating shaft 14.

According to the above configuration, when the first holder 9 and the second holder 10 are appropriately rotated, the electrode tip position 6 is adjusted at any position within a circle E having a radius A + B around the rotation shaft 14. (See FIG. 5). After the adjustment is confirmed, the second holder 10 can be fixed by tightening the bolt-shaped fixing member 16 provided on the arm. Therefore, even if the upper and lower electrodes are slightly displaced due to, for example, loosening of the fixtures of the equipment due to continued use, it is possible to easily correct the coincidence. As described above, while having a simple and economically efficient configuration, maintenance is easy, and adjustment to a desired position can be easily, manually, and freely performed. This embodiment is merely an example, and other shapes can be adopted for the shape of the holder and the shape of the shank / electrode as long as the effects of the present invention can be obtained.

DESCRIPTION OF SYMBOLS 1 Electrode position adjustment mechanism 2 Arm 3 Electrode 4 Straight shank 5 Electrode tip 6 Tip position 7 Axis 8 Water passage 9 First holder 10 Second holder 11 First part 12 Second part 13 Rotation axis 14 Rotation axis 15 Housing 16 Fixture

Claims (8)

A holder for holding at least one electrode of the spot welding machine,
A first holder that houses the electrode and is rotatable about a first rotation axis;
A second holder with a second axis of rotation for rotatably holding the first holder;
The first rotation axis is located at a distance from the tip of the electrode;
A second rotation axis is located at a position separated from the first rotation axis;
An electrode position adjusting mechanism for a spot welding machine, wherein the tip position of an electrode tip can be adjusted within a predetermined range by rotation of a first holder and a second holder. The first holder is
A first portion having a first axis of rotation at its center and rotatably held by a second holder;
A second portion for holding the electrode, wherein a diameter of the second portion is larger than that of the first portion, and a center axis of the second portion is located at a distance from the first rotation axis. The electrode position adjusting mechanism according to claim 1. The electrode position adjusting mechanism according to claim 2, wherein in the first holder, the first portion has a tapered shape, and the second portion holds a straight shank. The electrode position adjusting mechanism according to any one of claims 1 to 3, wherein the second holder has a cylindrical shape, and the first rotation axis and the second rotation axis are parallel to each other. The distance between the first rotation axis and the second rotation axis is equal to the distance between the first rotation axis and the rotation axis of the electrode. The electrode position adjusting mechanism according to the paragraph. The electrode position adjusting mechanism according to any one of claims 2 to 5, wherein a central axis of the second portion of the first holder and a central axis of the electrode coincide with each other. The electrode position adjusting mechanism according to any one of claims 1 to 6, further comprising a tightenable member that fixes a position of the first holder or the second holder. A spot welding machine comprising the electrode position adjusting mechanism according to claim 1.

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