JPH0596380A - X type welding gun - Google Patents

Abstract

PURPOSE:To provide the X type welding gun which has a welding function identical to a C type welding gun while it is the X type welding gun, hardly causes interference as compared with the C type welding gun and can perform welding even on a complicated welding place with good workability. CONSTITUTION:A couple of gun arms 3 and 4 of the X type welding gun which are pivoted on a common axis 2 and opened and closed by a pressurizing cylinder 5 are arranged side by side on one side in the pressurizing direction for works. A bend 4c is formed on the front end of one gun arm 4 and electrode tips 3b and 4b are fitted on the front end of the other gun arm 3 and on the tip of the bend 4C respectively so that these are opposed to each other. The place such as a wheel arch A1 of a rear wheel A of a car body which was welded by the C type welding gun (a) can be welded by the X type welding gun, in this case, welding can be performed without penetrating a gun main body into the rear wheel A like the C type welding gun and the interference with the car body is hardly caused.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-type welding gun used for boost welding of automobile bodies.

[0002]

2. Description of the Related Art Welding guns include an X-type welding gun in which a pair of gun arms pivotally supported by a common pivot are opened and closed by a pressure cylinder provided between the tail ends of both gun arms, and a pressure cylinder. There is a C-type welding gun in which a movable gun arm attached to a piston rod of a pressure cylinder is opposed to a fixed gun arm fixed to the cylinder body. The conventional X-type welding gun is provided with a pair of gun arms facing each other in the pressing direction of the workpiece, and when both gun arms are closed so as to approach each other, an electrode tip attached to the tips of both gun arms. In the meanwhile, the point where the work is struck is held under pressure.

[0003]

When the above-mentioned conventional X-type welding gun is used to weld the opening flange portion inside the outer edge of the work, the welding gun is constructed such that one gun arm is the front side space of the work and the other gun arm is It is necessary to advance inward from the outer edge side of the work so as to face the space on the back side of the work, and even if there is an obstacle only in the space on one side of the work, the welding gun cannot be advanced any more and welding cannot be performed. When moving the welding gun to weld a plurality of spot welding points on the opening flange, if there is an obstacle in the gun movement path in the space on one side of the workpiece, the welding gun is temporarily retracted to the outside to overcome the obstacle. If it becomes necessary to move the welding gun back and forth by opening the pair of gun arms wider than the normal opening / closing stroke, if there is no choice but to reduce efficiency and if there is a raised portion on the outer edge side of the work. The no longer obtained, will have to use a complex that with a stroke switching mechanism as welding gun. When the opening flange portion of the work is welded by the C-type welding gun, the above problems do not occur because the welding gun can be moved in the space on the front side of the work even if there is an obstacle on the front and back side of the work, for example, the space on the back side. However, since the entire gun body including the pressurizing cylinder needs to enter the front side space of the work, it cannot be applied when the front side space of the work is not wide open, and the application is limited. Further, the wheel arch portion A ₁ of the rear wheel house A of the automobile body as shown in FIG. 2 is welded by the C-type welding gun indicated by the phantom line in the figure because the conventional X-type welding gun cannot deal with it. In this case, since a part of the gun body enters the wheel house A, interference with the vehicle body is likely to occur. In view of the above points, the present invention provides an X-type welding gun which has the same advantages as the C-type welding gun and requires less space for interference escape than the C-type welding gun. Has a purpose.

[0004]

[Means for Solving the Problems] In order to achieve the above object,
The present invention relates to an X-type welding gun having a pair of gun arms which are pivotally supported by a common pivot and extend to the front, and both gun arms are arranged side by side on one side in the pressing direction with respect to the work, and one of the first arms is provided.
At the front end of the gun arm, a first electrode tip that comes into contact with the work from one side is attached, and at the front end portion of the other second gun arm, a bent portion that extends by bending in the longitudinal direction of the first electrode tip is formed. A second electrode tip facing the first electrode tip is attached to the tip.

[0005]

Since a pair of gun arms are juxtaposed on one side in the pressurizing direction with respect to the work, if there is a space for moving the gun arms in the space on one side of the work, for example, the space on the front side, there is an obstacle in the space on the back side. Both gun arms can be moved to any position on the work in the space on the front side. Then, when the tips of both gun arms reach the opening inside the workpiece, the bent portion of the second gun arm is inserted into the opening, and the tips of the bent portions are wrapped around the back side of the work to attach the first electrode tip to the work. The front side and the second electrode tip are positioned on the back side of the work, and the welding is performed by sandwiching the opening flange portion from both sides with pressure by both electrode tips. Also, the wheel arch part of the rear wheel house of the automobile body can be welded by wrapping the bent part of the second gun arm around the back side of the wheel arch part. In this case, only the front end part of the gun arm can be inserted into the rear wheel house. Since it is not necessary to insert the gun body into the rear wheel house unlike the C-type welding gun, there is no problem of interference with the vehicle body. By the way, when welding the front flange of the opening of the work as seen from the work outer edge, the bent portion of the second gun arm is formed so as to be positioned in front of the front end of the first gun arm. If the mounting position of both electrode tips is on the rear side of the bent portion, the bent portion can be positioned on the front side of the flange portion and both electrode chips can sandwich the flange portion under pressure. When welding the flange portion or the lateral flange portion, if the gun arm is kept facing forward, the bent portion interferes with the flange portion and the electrode tip cannot hold the flange portion under pressure. In this case, the bent portion of the second gun arm is
It is formed so as to be located rearward of the front end of the gun arm so that the mounting positions of both the first and second electrode tips are on the front side of the bent portion, or the bent portion of the second gun arm is located laterally of the front end of the first gun arm. If it is formed so as to be located on one side in the direction and the mounting positions of the first and second electrode tips are located on the other side in the lateral direction of the bent portion, the rear side flange portion or the gun arm may be left facing forward. The lateral flange portion can be pressed and held by both electrode tips without causing interference of the bent portion with the flange portion. As described above, various welding points can be dealt with by changing the positional relationship between the bent portion and the electrode tip.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numeral 1 denotes a gun bracket which is attached to the working end of a robot, and a pair of gun arms 3 and 4 extending forwardly on a pivot 2 attached to the bracket 1 are provided at their rear ends. The pressure cylinder 5 is attached to the lever portion 3a extending to the rear end of the one first gun arm 3 and the piston of the cylinder 5 is attached to the lever portion 4a extending to the rear end of the other second gun arm 4. The rod 5a was connected via a link 5b, thus forming an X-type welding gun opened and closed by the cylinder 5. In order to prevent the gun arms 3 and 4 from swinging due to their own weight, springs 7 and 7 that hold the gun arms 3 and 4 in a neutral posture by sandwiching a tongue piece 6 protruding from a lever portion 4a from the top and bottom of the gun body 1. Is provided.

The gun arms 3 and 4 are arranged side by side on one side in the pressing direction of the work, that is, on the upper side in the drawing. At the front end of the first gun arm 3, a first electrode tip 3b that abuts on the work is attached from the upper side, and A bent portion 4c that bends downward and extends is formed at the front end portion of the 2-gun arm 4, and a second electrode tip 4b facing the first electrode tip 3b is attached to the tip of the bent portion 4c. Then, when the piston rod 5a of the pressure cylinder 5 is driven to the downward extension side and the second gun arm 4 is swung upward, the second electrode tip 4b abuts against the work from below, and at the same time The first gun arm 3 is swung downward by the reaction force to move the first electrode tip 3
b is brought into contact with the work from above, and the work is sandwiched between the electrode chips 3b and 4b under pressure. In this embodiment, the bent portion 4c has the two electrode chips 3b and 4b.
Is formed so as to be located in front of the front end of the first gun arm 3 so that the mounting position thereof is on the rear side of the bent portion 4c.

When the X-type welding gun constructed as described above is used, as shown in FIG. 2, the tip of the bent portion 4c is wrapped around the rear side of the wheel arch portion A ₁ of the rear wheel house A of the automobile body to make the electrode tip 3b. The arch portion A ₁ between 4b
Can be held under pressure, in this case a C-type welding gun a shown by phantom lines
Unlike the above, since the main body of the gun including the pressurizing cylinder 5 does not need to be inserted into the rear wheel house A, interference with the work is less likely to occur, and even if the radius of curvature of the wheel arch portion A ₁ is small, Reinforcement welding can be reliably performed over the entire length.

It is also possible to additionally weld the opening flange portion B ₁ of the window B of the automobile body as shown in FIG. 3 by using the above X-type welding gun. However, since the gun main body enters in front of the window B, the welding robot having the welding gun a easily interferes with other welding robots performing additional welding in the engine room. Since the main body portion can be located on the side of the vehicle body, such a problem does not occur.

FIG. 4 shows a state in which the inner flange C ₁ of the workpiece C set on the jig 9 mounted on the jig base 8 via the leg pieces 9a is welded by the X-type welding gun.
When the conventional X-type welding gun having a pair of gun arms facing each other up and down the flange C ₁ is additionally welded at a plurality of positions in the longitudinal direction of the work C, the lower side of the jig 9 is made to enter. In order to prevent the gun arm from interfering with the leg piece 9a, the welding gun has to be temporarily retracted outward at the position where the leg piece 9a is arranged, which deteriorates the work efficiency. Together with work C
Since the flange C ₁ can be pressed in between the electrode tips 3b and 4b by advancing inward through the upper space of the work piece, the welding gun does not retract outward at the position where the leg piece 9a is arranged, and the work piece C does not move in the longitudinal direction. Can be efficiently welded to the flange C ₁ by moving to the position, and when moving the gun arms 3 and 4 forward and backward with respect to the work C, it is not necessary to open the gun arms 3 and 4 as much as the conventional X-type welding gun, and a switching mechanism for opening and closing strokes. Is unnecessary.
Further, when the flange C ₁ is welded with the C-type welding gun a, the entire gun body needs to be inserted into the upper space of the work C. Therefore, the upper space of the work C must be wide open upward. Although welding cannot be performed, in the above X-type welding gun, only the gun arms 3 and 4 need to be inserted into the upper space of the work C, and the arrangement space (the range shown by the hatched lines in FIG. 4) and the work C for the transfer equipment and the like. Welding can be done even if there is a small space for interference escape between.

By the way, in the above-mentioned embodiment, the second gun arm 4 is located above the first gun arm 3, but the second gun arm 4 is placed in the first position as in the embodiment shown in FIG.
The slits 4d for receiving the first gun arm 3 are formed on the second side of the gun arm 3 side by side, or as in the embodiment shown in FIG. 6, so that the first gun arm 3 and the second gun arm 4 are arranged side by side. The flanges C ₁ on the inner side of the workpiece C can be welded as shown in FIG. 4 even if the space for interference escape is narrower. In the above embodiment, the pivot 2 is located on the same plane as the pressing surface P between the electrode tips 3b and 4b, but depending on the application, the pivot 2 may be located above the pressing surface P as shown in FIG. Alternatively, as shown in FIG. 8, the pivot 2 may be located below the pressure surface P.

Further, in the above embodiment, the electrode chips 3b, 4
Although the mounting position of b is on the rear side of the bent portion 4c,
As shown in FIG. 9, the bent portion 4c is formed so as to be located rearward of the front end of the first gun arm 3, and the electrode tips 3b, 4
The mounting position of b may be on the front side of the bent portion 4c, which makes it possible to easily weld the opening flange portion D ₁ on the back side of the work D in the approach direction of the welding gun. The bent portion 4c is attached to the first gun arm 3 as shown in FIG.
If it is formed so as to be located on one side in the lateral direction of the front end of the welding tool and the mounting position of the electrode tips 3b, 4b is on the other side in the lateral direction of the bent portion 4c, it will be parallel to the approaching direction of the welding gun to the work E. A welding gun suitable for welding a large opening flange portion E ₁ can be obtained.

[0013]

As is apparent from the above description, according to the present invention, the inner flange portion of a work can be welded without being obstructed by an obstacle in the space on one side of the work. It has the same advantages as the C-type welding gun, and unlike the C-type welding gun, welding can be performed even in a place where the space for interference escape is limited. Can be welded without letting the gun body go into the rear wheel house, and interference is less likely to occur, and the application can be expanded compared to the C-type welding gun.
This has the effect of improving workability by reducing restrictions on work for preventing interference.

[Brief description of drawings]

FIG. 1 is a view showing a first embodiment of the welding gun of the present invention,
(A) is a side view, (b) is a plan view

FIG. 2 is a diagram showing an example of use of the welding gun of FIG.

FIG. 3 is a view showing another example of use of the welding gun of FIG.

FIG. 4 is a diagram showing still another example of use of the welding gun of FIG.

FIG. 5 is a view showing a second embodiment of the welding gun of the present invention,
(A) is a side view, (b) is a plan view

FIG. 6 is a view showing a third embodiment of the welding gun of the present invention,
(A) is a side view, (b) is a plan view

FIG. 7 is a side view showing a fourth embodiment of the welding gun of the present invention.

FIG. 8 is a side view showing a fifth embodiment of the welding gun of the present invention.

FIG. 9 is a side view showing a sixth embodiment of the welding gun of the present invention.

FIG. 10 is a perspective view of the essential parts of a seventh embodiment of the welding gun of the present invention.

[Explanation of symbols]

 2 Axis 3 First Gun Arm 3b First Electrode Tip 4 Second Gun Arm 4b Second Electrode Tip 4c Bent Section

Claims (4)

[Claims] 1. A shaft 1 supported by a common pivot and extending forward.
In an X-type welding gun having a pair of gun arms, both gun arms are arranged side by side on one side in the pressing direction with respect to a work, and a first electrode tip that abuts the work from one side is attached to the front end of one first gun arm A bent portion extending in a longitudinal direction of the first electrode tip is formed at a front end portion of the second gun arm, and a second electrode tip facing the first electrode tip is attached to a tip of the bent tip. X
Type welding gun. 2. The bent portion of the second gun arm is formed so as to be located in front of the front end of the first gun arm.
The X-type welding gun according to claim 1, wherein the mounting positions of both electrode tips are on the rear side of the bent portion. 3. A bent portion of the second gun arm is formed so as to be positioned rearward of a front end of the first gun arm, and the first and second gun arms are formed.
The X-type welding gun according to claim 1, wherein the mounting position of both electrode tips is on the front side of the bent portion. 4. The bent portion of the second gun arm is formed so as to be positioned on one side in the lateral direction of the front end of the first gun arm, and the mounting positions of the first and second electrode chips are on the other side in the lateral direction of the bent portion. The X-type welding gun according to claim 1, wherein