JPH05192771A - Spot welding equipment - Google Patents

Abstract

PURPOSE:To weld welding points on the base and the vertical wall surface of a work having an U-shaped cross section such as the floor side by one kind of welding gun. CONSTITUTION:A fixed electrode unit 31 fitted on an assembly stage has fixed electrode tips 32 which are positioned on the outside spot positions of the vertical wall. welding points S of the work 11 having the U-shaped cross section mounted on the assembly stage. After the welding point on the base B of the work 11 having the U-shaped cross section is welded by the C type welding gun 15, both electrodes 21 and 23 of the C type welding gun are engaged With the engaging surfaces 41 provided in opposition on one ends of both movable arms 38 and 39 and an auxiliary electrode unit 36 is held by the C type welding gun 15. Continuously, the auxiliary electrode unit 36 is carried inside the work 11 having the U-shaped cross section and rotational electrode tips 35 are positioned on the inside spot positions of the vertical wall welding points S by moving the C type welding gun 15. Hereafter, the vertical wall welding points S are welded jointly by the fixed electrode tips 32 and the rotational electrode tips 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a welding device for parts,
Particularly, it relates to a spot welding device.

[0002]

2. Description of the Related Art Welding technology is currently used in many industries, and spot welding is often used in the assembly of automobile bodies. Spot welding is a welding method performed by pressing a welding portion with a welding gun having an electrode and energizing the welding portion. In assembling an automobile body, a welding gun having a shape suitable for a welding position is generally used. When a welded part 11 having a U-shaped cross section is joined by spot welding using a bottom surface B and two vertical wall surfaces T as shown in FIG. 3, as shown in FIG. 4 (a). The welding point of the bottom surface B is welded with a simple C-type welding gun 15, and
The welding points on the vertical wall surface T are welded by the X-type welding gun 16 shown in (b). As the work 11 having a U-shaped cross section shown in FIG. 3, a member such as a floor side can be used.

As shown in FIG. 4 (a), a C-type welding gun 15 has a first electrode tip 21 and a second electrode tip fixed to a gun arm 22 which can be expanded and contracted by a cylinder (not shown). 23 and U-shaped work 11
It is designed to be clamped and welded. Therefore, the first
In a state where the electrode tip 21 is separated from the second electrode tip 23, the second electrode tip 23 is positioned at a hitting point outside the bottom surface B of the work 11, and then the first electrode tip 21 is moved close to the bottom surface B to move the bottom surface. The welding point at B is welded by both electrode tips 21 and 23. Further, as shown in FIG. 4B, the X-type welding gun 16 has two arms 25 and 26 which are rotatable about the same rotary shaft, and both arms 25 and 26 are rotatable. That is, by opening and closing, the electrode tips 27 and 28 attached to the tips of both arms 25 and 26 can be moved toward and away from each other. Therefore, the arms 25 and 26 are opened at an appropriate angle to sandwich the vertical wall T, and then the welding point is clamped by the electrode tips 25 and 26 to weld the vertical wall T.

[0004]

However, in order for a robot to perform such work using two types of welding guns, a gun changer for replacing the welding guns attached to the robot is required. If the robots to which the respective welding guns are attached are arranged on different assembly stages, the welding gun replacement work can be eliminated, but the assembly time will increase due to the increase in the number of processes. Also, as means for automating the welding work without changing the holding of the welding gun and increasing the number of processes, as well as welding the welding points present on either one of the vertical wall surface and the bottom surface by multi-spot welding,
It is conceivable to weld the welding point on the other side with a robot equipped with a dedicated welding gun, but new equipment must be introduced.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a spot welding apparatus capable of welding all welding points of a work having a U-shaped cross section with one kind of welding gun.

[0006]

In order to achieve the above object, the present invention provides a bottom wall portion and a vertical wall portion in a work having a bottom wall portion and a vertical wall portion and having a U-shaped cross section. A spot welding apparatus for welding, which has a first electrode and a second electrode facing each other and capable of moving toward and away from each other, and a C-type spot welding gun for directly welding a bottom wall portion of the work. ,
A fixed electrode unit having two fixed electrode tips facing the outer surface of the vertical wall portion of the work and facing each other, and an engaging portion engaging with the electrode of the C-type spot welding gun are provided at one end. A rotary electrode tip for welding the vertical wall portion of the work in cooperation with the fixed electrode tip is provided at the other end and has two rotary arms that are rotatable relative to each other, The spot welding apparatus has an auxiliary electrode unit in which an arm is provided with a biasing means in a direction in which the engaging portions move away from each other.

[0007]

When the workpiece having a U-shaped cross section, which is a part to be welded, is placed on the positioning jig, the outer electrode tip is located outside the welding point on the vertical wall surface. After welding the welding points on the bottom surface of the workpiece with a U-shaped cross section by the C-type welding gun, engage both electrode tips of the C-type welding gun with the engaging surface of the auxiliary electrode unit, and move the movable electrode by the C-type gun. Hold. Move the C-type welding gun, insert the auxiliary electrode unit inside the work with a U-shaped cross section, position the rotating electrode tip at the inner welding point of the vertical wall welding point, and then use the C-type welding gun. When the engagement surface of is further clamped, the welding point of the work can be welded by the cooperation of the inner electrode tip and the outer electrode tip.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. Note that the same reference numerals are given to those described in the related art. FIG. 1A is a sectional view showing a state in which the electrodes of the spot welding apparatus of this embodiment are positioned at the welding points of the vertical wall portion welding points, and FIG. 1B shows the spot welding apparatus of this embodiment. It is sectional drawing which shows the state which is welding the vertical wall part welding point using. 2A is a top view of the auxiliary electrode unit, and FIG. 2B is a front view of the auxiliary electrode unit. FIG. 3 is a perspective view of a U-shaped workpiece having a U-shaped cross section which is a welding target in the present embodiment.

As shown in FIG. 1A, a work 11 having a U-shaped cross section having a bottom wall B and a vertical wall T can be positioned on an assembly stage (not shown), and is shown in the drawing. The U-shaped fixed electrode unit 31 is attached to the unassembled stage. The fixed electrode unit 31 has fixed electrode tips 32 facing each other, and each fixed electrode tip 32 is positioned at the outer welding point of both vertical wall welding points S of the workpiece 11 having a U-shaped cross section. Both fixed electrode chips 32 are connected via a conductor and are in a conductive state. As shown in FIG. 3, the U-shaped work 11 having a cross section is welded at the overlapping portion D.

Further, as shown in FIG. 1 (b), the vertical wall T
The auxiliary electrode unit 36 having the rotating electrode tip 35 which comes into contact with the welding point of from inside is held by the C-type welding gun 15. As shown in FIGS. 2A and 2B, the auxiliary electrode unit 36 includes a support member 37.
The first rotation arm 38 and the second rotation arm 39 are rotatably attached to the support member 37 so as to face each other. One end of each of the rotary arms 38 and 39 is bent at a right angle in a direction away from the opposing rotary arm, and both electrodes 21 of the C-shaped welding gun are provided on both concave engaging surfaces 41. 23 can be engaged. Further, a spring 4 serving as an urging means is provided between the rotating arms 38 and 39.
2 is provided, and both rotating arms 38 and 39 are biased by the spring 42 in a direction in which they are separated from each other. Therefore, as shown in FIG. 1B, the two electrode tips 21 and 23 attached to the C-type welding gun 15 and the two engaging surfaces 41 can be reliably engaged with each other.

Rotating electrode chips 35 are attached to the other end of the first rotating arm 38 and the other end of the second rotating arm 39 at positions facing each other. The electrode tips 35 are provided so as to project in mutually opposite directions. Therefore, both rotating electrode chips 35 can be moved toward and away from each other by rotating the rotating arm. Note that, as shown in FIG. 2 (b), both rotating arms 38, 3
Since 9 is attached to the support member 37 adjacently, both rotating arms 38 and 39 are in contact with each other at the end portion on the electrode tip side when not in use.

Next, the welding procedure will be described. Figure 1
As shown in (a), two workpieces 11 having a U-shaped cross section are placed on an assembly stage (not shown). When both works 11 are placed on the assembly stage, the fixed electrode tip 32 installed on the assembly stage (not shown)
Is positioned at the outer hitting point position of the welding point S on the vertical wall T of the work 11. When the placement of the work 11 is completed, the C-type welding gun 1 in which both the electrode tips 21 and 23 are separated in advance
The second electrode tip 23 of No. 5 is positioned at the outer welding point position of the welding point on the bottom surface B. Then, the first electrode chip 21
Is moved closer to the second electrode tip 23 to weld the welding point on the bottom surface B as shown in FIG.

When the welding of the bottom surface B is completed, the C-type welding gun 15 is once separated from the work 11. Then, Figure 1
As shown in (a), both electrode tips 21 and 23 of the C-type welding gun 15 are engaged with both engagement surfaces 41, and the auxiliary electrode unit 36 is held by the C-type welding gun 15. Subsequently, the auxiliary electrode unit 36 held by the C-type welding gun 41
Is inserted inside the workpiece 11 having a U-shaped cross section, and both pivoting electrode tips 35 of the auxiliary electrode unit 36 are positioned at the inner welding point of the vertical wall welding point S. In addition,
Since both engaging surfaces 41 of the auxiliary electrode unit 36 are urged by the spring 42 in the direction to be separated from each other and are concave surfaces, both engaging surfaces 41 of the C-type welding gun 15 are fixed by the both electrode tips 21 and 23. By applying pressure, both electrode chips 21,
23 and both engagement surfaces 41 are securely engaged. Both electrode tips 21 and 23 of the C-type welding gun 15 can be pressurized stepwise by a two-step pressing operation.
Both electrode tips 21 and 23 and the engaging surface 41 of the auxiliary electrode unit 36 are engaged with each other by the stepwise pressing operation. Further, both rotating electrode tips 35 are biased by springs 42 in a direction of approaching each other, and the workpiece 11 is only welded.
Since it comes into contact with the auxiliary electrode unit 3
When inserting 6 inside the work 11, the rotating electrode tip 3
5 does not interfere with the work 11.

After the rotary electrode tip 35 is positioned at the inward position of the vertical wall welding point S in this manner, both engaging surfaces 41 are further pressed by the C-type welding gun 15 to rotate with the fixed electrode tip 32. The welding point S is welded by the moving electrode tip 35. After the welding is completed, the auxiliary electrode unit 36 held by the C-type welding gun 15 with the first-stage pressure is taken out from the inside of the work 11, and the series of operations is completed.

In the welding of the welding point S on the vertical wall surface T,
The auxiliary electrode unit 36 may be carried into the inside of the work 11 having a U-shaped cross section by a transportation means such as an actuator. In this case, the auxiliary electrode unit 3
After the 6 is carried in and the rotary electrode tip 35 is positioned at the striking position of the vertical wall welding point S, both engaging surfaces 41 are pressed by the C-type welding gun 15 to weld the work 11. After the welding is completed, the electrode tips 21 and 23 of the C-type welding gun are separated from the engaging surfaces 41, and then the auxiliary electrode unit 36 is moved by a conveying means such as an actuator.
May be retracted to the retracted position.

[0016]

As described above, according to the present invention, the welding points on the bottom surface and the vertical wall surface of the work having a U-shaped cross section can be welded only by the C-type welding gun. Also, the assembly equipment can be simplified.

[Brief description of drawings]

1 (a) is a cross-sectional view showing a state in which the spot welding apparatus of the present embodiment is positioned at a welding point of a vertical wall welding point, and FIG. 1 (b) shows welding points on a vertical wall. Showing the state of

FIG. 2 is a top view and a front view showing an auxiliary electrode unit,

FIG. 3 is a perspective view of a work having a U-shaped cross section to be welded,

FIG. 4 is a diagram showing a state in which a welding point on the bottom surface is welded by a C-type welding gun, and a state in which a welding point on a vertical wall surface is being welded by an X-type welding gun.

[Explanation of symbols]

11 ... Work 15 ... C type welding gun 1
6 ... X type welding gun 31 ... Fixed electrode unit 32 ... Fixed electrode tip 3
5 ... Rotating electrode tip 36 ... Auxiliary electrode unit 38 ... First rotating arm 3
9 ... 2nd rotation arm 41 ... Engagement surface 42 ... Spring
B ... Bottom T ... Vertical wall

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoichi Takahashi 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd.

Claims (1)

[Claims] 1. A spot welding device for welding the bottom wall portion and the vertical wall portion in a work having a U-shaped cross section and having a bottom wall portion and a vertical wall portion, which are opposed to each other. A C-type spot welding gun having a first electrode and a second electrode which are movable toward and away from each other, and which directly welds the bottom wall portion of the work, and each of which faces the outer surface of the vertical wall portion of the work and is mutually opposed. A fixed electrode unit having two facing fixed electrode tips and an engaging portion that engages with the electrode of the C-type spot welding gun are provided at one ends, and the fixed electrode unit cooperates with the fixed electrode tip to vertically move the workpiece. The rotating electrode tip for welding the wall portion is provided at the other end, and has two rotating arms that are rotatable relative to each other, and the engaging portions are attached to the rotating arms so that the engaging portions separate from each other. Auxiliary electrode unit provided with biasing means. And spot welding equipment.