JPH11320112A - Electric gun - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric gun wherein, adjustment of the welding force and the adjustment of the open stroke in each set are easy in case of an electric gun having 2 sets of the electrodes; the electrode force is not affected by abrasion of electrodes and the bearing or deflections of gun arm which changes in accordance with each welding force and so on; and an accurate welding force is output against the welding force set and accordingly the stabilized welding force is obtained by simple control. SOLUTION: A speed reducer 14 is connected with a motor 12 which is placed at the rear of a junction part 3 of the first and the second arms 1, 4. The second and fourth arms 4, 9 are rotated by the power transmission mechanism on the output side of the speed reducer. This transmission mechanism is composed of a swinging lever 16 on the output side of the speed reducer and a link 6 between the same lever and the second arm. The swinging lever is coupled with the link by the transmission mechanism so that there is almost linear relation between the output of the motor shaft and the electrode pressing force transmitted to electrodes 5, 10 from a tip of the swinging lever via the link. Furthermore, the third and fourth arms 7, 9 are designed to do the release action when the first and second arms do the pressurization action.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-type electric welding machine having a first and a second gun arm provided with opposing electrodes at the ends thereof. A gun arm is formed, and a fourth gun arm extending from the second gun arm or independently rotatably supported at the connecting portion is formed at the tip of the third gun arm. An electrode provided at the tip of the fourth gun arm is opposed to the electrode, and a speed reducer is connected to an output shaft of a motor arranged rearward from a connection portion between the first and second gun arms, and an output of the speed reducer is provided. And an electric gun in which the second and fourth gun arms are rotated by a power transmission mechanism provided on the side.
The present invention relates to a rotating device for a vehicle.

[0002]

2. Description of the Related Art Conventionally, a third gun arm branched from a first gun arm of an X-type electric welding machine having first and second gun arms provided with electrodes opposed to each other at the tip thereof is supported. And forming a fourth gun arm extending from the second gun arm. The electrode provided at the tip of the fourth gun arm is opposed to the electrode provided at the tip of the third gun arm. A welding gun (hereinafter referred to as the former) in which the second and fourth gun arms are rotated by a piston rod of a cylinder is known (for example, see Japanese Utility Model Publication No. 52-44582).

[0003] Further, in the X-type electric gun, a servo
In order to obtain a high pressing force while keeping the capacity of the gun small, a second gun arm rotatably supported by the gun bracket is provided for the first gun arm integrated with the gun bracket. An output disk fixed to the output side of the speed reducer via a speed reducer, a pin provided at a position near the outer periphery of the output disk, and a pin provided between the pin and a rear end of the second gun arm. There is a type in which pressure is applied by a crank mechanism (pressure mechanism) constituted by a connector arm (link) (hereinafter referred to as the latter) (for example, see Japanese Patent Application Laid-Open No. Hei 9-248678).

[0004]

However, in the former known welding gun, since the piston rod from the air cylinder is used to drive the gun arm, it is difficult to adjust the pressing force and the opening stroke. Is a problem.

[0005] Further, in the latter known gun arm rotating means, in order to keep the capacity of the servomotor small,
The angle formed by the line connecting the center of the output disk via the speed reducer and the center of the pin provided near the outer periphery of the disk, and the ring connecting the rear end of the second gun arm and the pin. 18
The pressing operation is performed at a position slightly before the angle becomes 0 degrees, and the pressing force is increased by using a so-called toggle mechanism. However, in such a pressurizing means, the degree of change in the pressing force is large with respect to the amount of change in the rotation angle of the disk due to the relationship between the output of the link and the rotation torque of the disk, which is also a linear function change. Rather, it changes exponentially as it approaches 180 degrees, and the electrode pressure changes significantly with a small change in the angle between the pin and the link. In actual use of a welding machine, in addition to the change in the amount of wear of the electrode, the amount of deflection of the arm changes with each pressing force, and the change in the aged wear of each support pin bearing including the main shaft part. The angle changes and it is difficult to obtain a stable angle. For this reason, according to the characteristics of the toggle mechanism in which the pressing force changes exponentially with respect to the amount of change in the rotation angle of the disk, in the above-described known technique, control is performed to obtain an accurate pressing force that matches the set pressing value. There is a problem that it is extremely difficult.

[0006] The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide two sets of electrodes having first to fourth gun arms. It is extremely easy to adjust the pressure and open stroke of each set with an electric gun, and the electrode pressure affects the wear of the electrodes and bearings and the bending of the gun arm that changes with each pressure. It is an object of the present invention to provide an electric gun capable of outputting an accurate pressing force with respect to a pressing force set by a simple control without receiving the same and obtaining a stable pressing force.

[0007]

In order to achieve the above object, an electric gun according to the present invention comprises an X-type electric gun having first and second gun arms provided with electrodes opposed to each other at a tip thereof. The third gun arm branched off from the first gun arm of the welding machine
And forming a fourth gun arm extending from the second gun arm, with the electrode provided at the tip of the fourth gun arm facing the electrode provided at the tip of the third gun arm. A speed reducer is connected to an output shaft of an electric motor disposed behind the connecting portion of the first and second gun arms, and the second and fourth power transmission mechanisms are provided on the output side of the speed reducer.
The gun arm is rotated, and the power transmission mechanism is
A swing lever fixed to the output side of the speed reducer, and a link formed between the lever and the second gun arm or between the lever and the fourth gun arm. The output of the motor shaft and the swing The swing lever and the link are connected so that the electrode pressing force transmitted from the tip of the moving lever to the electrode via the link has a substantially linear relationship, and the first and second gun arms are pressurized. In some cases, the third and fourth gun arms perform an opening operation.

[0008] Further, a first electrode having opposing electrodes at the tip end.
And a third gun arm branched from the first gun arm of the X-type electric welding machine which pivotally supports the second gun arm, and which is extended from the second gun arm or connected to the connecting portion. A fourth gun arm pivotally supported independently and rotatably is formed, and a fourth gun arm is provided on an electrode provided at the tip of the third gun arm.
The electrodes provided at the tip of the
A speed reducer is connected to an output shaft of a motor disposed behind a connection portion of the gun arm, and the second and fourth gun arms are rotated by a power transmission mechanism provided on an output side of the speed reducer. An oscillating lever having the power transmission mechanism fixed to the output side of the speed reducer and having two link joints; and a link joint between one link joint of the lever and the second gun arm and the other link joint. And a link formed between the second gun arm and the fourth gun arm. The output of the motor shaft and the electrode pressing force transmitted from the tip of the swing lever to the electrode via each link are substantially linear. The swing lever and each link are connected so as to have a relationship, and the third lever is provided when the first and second gun arms are pressed.
And the fourth gun arm performs an opening operation.

A first electrode having opposing electrodes at the tip thereof
And a third gun arm branched from the first gun arm of the X-type electric welding machine having the second gun arm pivotally supported, and a fourth gun arm extending from the second gun arm.
A third arm is formed on the electrode provided at the tip of the third gun arm.
An electrode provided at the tip of the gun arm is opposed to the reduction gear connected to the output shaft of the electric motor disposed behind the connection between the first and second gun arms, and provided at the output side of the reduction gear. The power transmission mechanism rotates the second and fourth gun arms. The power transmission mechanism includes a swing lever fixed to the output side of the speed reducer, and a groove provided in the swing lever. Or a roller and a roller or a groove provided in the second gun arm, and the output of the motor shaft and the tip of the oscillating lever are transmitted to the electrode via the roller or the groove. The output of the motor shaft and the electrode pressure transmitted from the tip of the oscillating lever to the electrode via a roller or a groove are substantially linear so that the applied electrode pressure is substantially linear. The roller or groove provided on the second gun arm as shown in (1) is inserted into the groove or roller at the tip of the swing lever. Connected to, and first and second Gan'a - in which the beam is characterized in that to perform the opening operation - arm third and fourth Gan'a during pressurization operation.

[0010] Further, a first electrode provided with opposing electrodes at the tip thereof.
And a third gun arm branched from the first gun arm of the X-type electric welding machine having the second gun arm pivotally supported, and a fourth gun arm extending from the second gun arm.
A third arm is formed on the electrode provided at the tip of the third gun arm.
An electrode provided at the tip of the gun arm is opposed to the reduction gear connected to the output shaft of the electric motor disposed behind the connection between the first and second gun arms, and provided at the output side of the reduction gear. The second and fourth gun arms are rotated by a power transmission mechanism, and the power transmission mechanism comprises a gear fixed to the output side of the speed reducer and a gear provided on the second gun arm. The output of the motor shaft and the electrode pressure transmitted from the gear fixed to the output side of the speed reducer to the electrode via the gear provided on the second gun arm have a substantially linear relationship. The gear fixed to the output side of the speed reducer and the second
Mesh with a gear provided on the gun arm, and
And the third and fourth gun arms perform an opening operation when the second gun arm performs a pressurizing operation.

[0011]

Embodiments of the present invention will be described with reference to the accompanying drawings. 1 is a side view of an electric gun according to the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a side view of another embodiment of the electric gun according to the present invention, FIG. 4 is a side view of still another embodiment, FIG. 5 is a side view of still another embodiment. In each of the drawings, illustration of a secondary current circuit and the like is omitted.

1 and 2, reference numeral 1 denotes a fixed gun arm, which constitutes a first gun arm in the present invention. The fixed gun arm has an electrode 2 at a front end and a pivot shaft at a rear end. It is fixed to the connecting portion 3. Reference numeral 4 denotes a movable gun arm, which constitutes a second gun arm in the present invention. The movable gun arm 4 has an electrode 5 at the tip thereof opposed to the electrode 2 and a link 6 connected to an intermediate upper portion. The rear end is rotatably supported by the connecting portion 3 composed of the pivot. The first gun arm 1 and the second gun arm 4 constitute an X-type electric welding machine. Also,
A third gun arm 7, which is a fixed gun arm, is branched downward from the middle of the first gun arm 1 to form a third gun arm 7.
An electrode 8 is provided at the end of the second gun arm 4. A fourth gun arm 9 which is a movable gun arm is extended from the connecting portion 3 at the rear end of the second gun arm 4 to extend the fourth gun arm 9. An electrode 10 facing the electrode 8 is provided at the tip.

Reference numeral 11 denotes a gun bracket, and a connecting portion 3 comprising the pivot is provided at the tip of the gun bracket 11.
Are formed, and the rear end is connected to a wrist of a robot (not shown). An electric motor 12 is mounted above the middle of the gun bracket 11,
An output shaft 13 of the electric motor 12 and a speed reducer 14 arranged in the gun bracket 11 are connected by, for example, a belt transmission device 15.

An oscillating lever 16 made of a plate is fixed to the output side of the speed reducer 14. In addition, one end of the link 6 is provided at a middle upper portion of the second gun arm 4 with a pivot 17.
The other end of the link 6 is pivoted to the tip of the swing lever 16. Then, the gun bracket 11 between the center point 19 of the swing lever 16 and the connecting portion 3, the swing lever 16, the link 6, and the arc between the shaft 17 and the connecting portion 3.
The power transmission mechanism forms a substantially parallel four-node link with the gun bracket 11 as a fixed node.
Reference numeral 20 denotes a transformer for a welding machine attached to the rear of the gun bracket 11.

In the electric gun having the above-described configuration, the electric motor 12 rotates alternately in the forward and reverse directions. Then, as shown in FIG.
(In this case, electrodes 8, 10)
Is in the open state).
2 is rotated clockwise, for example, the rotation is reduced by the speed reducer 14 to rotate the swing lever 16 clockwise, and the second gun arm 4 is pulled by the link 6 to perform the opening operation. (At this time, the electrodes 8 and 10 start the pressing operation.) When the first and second gun arms are opened, the electric gun is moved by the robot and guided to the next work, and the electric motor 1 is moved with the lower electrode 2 in contact with the work.
Reverse 2 This rotation is decelerated by the speed reducer 14 to rotate the swing lever 16 counterclockwise, and the second gun arm 4 is pressed by the link 6 to perform a pressurizing operation (at this time, the electrodes 8, 10). Performs the opening operation), returns to the state of FIG. 1, and performs the welding operation (the above-described operation is performed by the first and second gun arms, and the welding operation by the third and fourth gun arms is not performed). Explanation of the case).

In order to perform the welding operation by the third and fourth gun arms from the state shown in FIG.
When the welding operation by the third and fourth gun arms is completed, the motor 12 is rotated in the reverse direction to rotate the motor 12 clockwise, for example, to press the electrodes 8 and 10. The electrodes 8 and 10 may be left open.

As described above, in the electric gun, after the rapid rotation of the electric motor 12 is reduced by the speed reducer 14, the second gun arm 4 and the fourth gun arm are connected via the swing lever 16 and the link 6. Since the arm 9 is opened or pressurized, the inertia moment value of the electric motor 12 in terms of the axis becomes small, and as a result, the acceleration / deceleration time when the electrode of the electric gun is opened and closed becomes short, and the welding speed of the welding machine is reduced. Shortening can be expected effectively. After the output is amplified by the speed reducer 14, the swing lever 16,
The second gun arm 4 and the fourth gun arm via the link 6
Since the arm 9 is opened or pressurized, a desired welding can be performed with less variation in the pressing force by the electrodes 5 and 10, and the speed reducer 14 having a relatively large diameter is connected to the gun arms 1 and 4. Since the gun arm is disposed rearward of the connecting portion 3, the effective depth of the gun arm unlike the conventional example is not reduced, and the gun can be applied to a large work. Also,
Since the torque and the amount of rotation at the time of forward rotation and reverse rotation of the motor 12 can be freely changed, welding by the electrodes 2 and 5 and welding by the electrodes 8 and 10 are independently applied to the work optimal for the work. Pressure and open stroke can be selected.

As described above, the power transmission mechanism is a swing lever 16, and the link 6 is a member of a substantially parallel four-joint link having the gun bracket 11 as a fixed joint. The output of the motor shaft 13, which is the output of the output shaft of the fixed reducer 14, and the swing lever 16.
Since there is an approximately linear relationship in proportion to the electrode pressing force transmitted to the electrodes 5 and 10 via the link 6 from the tip of the above, an accurate pressing force can be obtained with respect to the pressing force set by simple control. In addition, the second gun arm 4 and the fourth gun arm 9
Since the displacement angle of the swing lever 16 and the change angle of the oscillating lever 16 are the same, it is very easy to correct the electrode position due to electrode wear and to control the opening angles of the second gun arm 4 and the fourth gun arm 9.

In the above embodiment, the link 6 is provided between the swing lever 16 and the second gun arm 4, but the link 6 is provided between the swing lever 16 and the fourth gun arm 4.
Even if it is provided between the gun arms 9, substantially the same operation is performed.

Next, the embodiment shown in FIG. 3 will be described. This embodiment is substantially the same as the previous embodiment except that the swing lever 16 is provided with two link joints, and the second gun arm 4 and the fourth gun arm 9 are respectively joined with links. Therefore, substantially the same members are denoted by the same reference numerals and description thereof may be omitted.
In the figure, the swing lever 16 is formed so as to have link joints on the upper and lower sides. And the second cancer
One end of a link 6a is pivoted at an intermediate upper portion of the drum 4, and the other end of the link 6a is pivotally connected to a link joint at the upper portion of the swing lever 16. One end of the link 6b is pivoted to the fourth gun arm 9 and the other end of the link 6b is pivotally connected to a link joint at the lower part of the swing lever 16.

Therefore, in this embodiment, the link 6
A and 6b cooperate to reliably open and close the second gun arm 4 and the fourth gun arm 9. The fourth
The gun arm 9 may be rotatable independently of the connecting portion without extending from the second gun arm 4, in which case the second gun arm 4 is opened and closed by the link 6a, and the link 6a is opened and closed. The fourth gun arm 9 is opened and closed by 6b.

Next, the embodiment shown in FIG. 4 will be described. Also in this case, the same reference numerals are given to the substantially same members as those in the previous embodiment, and the description thereof may be omitted. In the drawing, reference numeral 31 denotes a roller mounted above the rear part of the second gun arm 4, and a groove 32 is formed at the tip of the swing lever 16, and the roller 31 is formed of a groove 32.
It can be moved along the inner circumference.

A transformer 20 for a welding machine is attached to the gun bracket 11, and the reduction gear 1 connected to the output shaft of the motor is connected to the transformer 20 for the welding machine.
4 are held.

In the electric gun having the above configuration, the upper and lower electrodes 2 and 5 are brought into contact with and pressurized on the work 21 as shown in FIG. 4 (at this time, the electrodes 8 and 10 are opened). If the motor is rotated in the counterclockwise direction, the rotation is reduced by the speed reducer 14 to rotate the swing lever 16 in the counterclockwise direction.
The arm 4 is pulled by the swing lever 16 via the roller 31 to perform an opening operation (at this time, the electrodes 8 and 10 enter a pressing operation). Then, the gun is moved by the robot in the open state and guided to the next work, and the electric motor is reversed while the lower electrode 2 is in contact with the work. This rotation is reduced by the speed reducer 14 to rotate the swing lever 16 clockwise, and the second gun arm 4 swings the swing lever 16 through the roller 31.
The pressing operation is performed by pressing by 16 (at this time, the electrodes 8 and 10 perform the opening operation), and the operation returns to the state of FIG. 4 to perform the welding operation. Since the roller 31 can move along the inner periphery of the groove 32 formed in the swing lever 16 when the second gun arm 4 is opened and pressurized, the swing lever 16 is moved. There will be no excessive force. (The above is the description of the case where the welding operation by the first and second gun arms is performed and the welding operation by the third and fourth gun arms is not performed.)

In order to perform the welding operation by the third and fourth gun arms from the state shown in FIG.
When the welding operation by the third and fourth gun arms is completed, the motors 12 are rotated counterclockwise, for example, and the electrodes 8 and 10 are pressed.
May be reversed to bring the electrodes 8, 10 into an open state.

In the case of this embodiment, the roller 31 provided on the second gun arm 4 is movably disposed in the groove 32 at the tip of the oscillating lever 16 and the oscillating lever 16 is provided. The position where the output shaft 33 of the speed reducer 14, the roller 31, and the connecting portion 3 are on the same straight line during the swinging of the speed reducer 14 are determined by the pressing positions by the first and second gun arms and the third and fourth gun arms. The position of the motor shaft, which is the output of the output shaft 33 of the speed reducer 14 to which the swing lever 16 is fixed, is set at a position substantially at the intermediate position of the pressurizing position of the swing lever 16 from the tip of the swing lever 16. -La 31
Are substantially linearly proportional to the electrode pressing force transmitted to the electrode 5 or the electrode 10 via the
The electrode pressing force is hardly affected by wear such as 8, 10 or the like, change in the amount of deflection of the gun arms 1, 4, 7, 9 or the like, or wear of each bearing. In addition, since the displacement angle of the second gun arm 4 or the fourth gun arm 9 and the change angle of the oscillating lever 16 are substantially linearly proportional, the electrode position correction due to electrode wear, the second gun arm, and the like. It is also very easy to control the opening angle of the fourth and fourth gun arms 9.

In this embodiment, a roller 31 is mounted above the rear part of the second gun arm 4 and a groove 32 is formed at the tip of the swing lever 16 so that the roller 31 is Is movable along the inner periphery of the second gun arm 4, but a groove is formed above the rear part of the second gun arm 4, and a roller is attached to the tip of the swing lever 16 so that the roller can be moved inside the groove. Even if it can move along the circumference, substantially the same operation is performed.

Next, the embodiment shown in FIG. 5 will be described. Also in this case, the same reference numerals are given to the substantially same members as those in the previous embodiment, and the description thereof may be omitted. In the drawing, reference numeral 41 denotes a gear attached to the rear end of the second gun arm 4, and reference numeral 42 denotes a gear formed at the tip of the swing lever 16 (fixed to the output shaft 33 of the speed reducer 14). Gears), and the two gears 41 and 42 are in mesh with each other.

Also in the electric gun having the above-described structure, the second gun arm 4 and the fourth gun arm are rotated by the gear 42 fixed to the output shaft 33 of the speed reducer 14 by alternately rotating the electric motor. 9 can be opened or pressurized. Since the meshing portion of the two gears 41 and 42 is substantially located on a straight line connecting the shaft 33 and the connecting portion 3, substantially the same operation as in the immediately preceding embodiment is performed.

[0030]

As described above, the electric gun according to the present invention has the first gun arm of the X-type electric welding machine which pivotally supports the first and second gun arms provided with the electrodes opposed to each other at the tips. Forming a third gun arm branched from the second gun arm and forming a fourth gun arm extended from the second gun arm or rotatably supported by the connecting portion independently and rotatably; The electrode provided at the tip of the fourth gun arm is opposed to the electrode provided at the tip of the arm, and a speed reducer is connected to the output shaft of the motor arranged behind the connection between the first and second gun arms. And
The second power transmission mechanism provided on the output side of the speed reducer
And rotating the fourth gun arm and the first
Since the third and fourth gun arms open during the pressurizing operation of the second gun arm and the second gun arm, the electric gun can freely adjust the torque and the amount of rotation during forward rotation and reverse rotation of the electric motor. The welding using the first and second gun arms and the welding using the third and fourth gun arms can be performed independently of each other with the optimum pressing force and opening stroke for the work. -This is an electric gun that allows you to select a tool.

Also, a speed reducer is connected to an output shaft of a motor arranged rearward from a connection between the first and second gun arms,
Since the second and fourth gun arms are rotated by the power transmission mechanism provided on the output side of the speed reducer, the rapid rotation of the motor is immediately reduced by the speed reducer, and then the power is transmitted via the power transmission mechanism. The second and fourth gun arms are opened or pressurized, so that the inertia moment value of the motor in terms of the axis becomes smaller. As a result, the acceleration / deceleration time when the electrode of the electric gun is opened and closed becomes shorter. Also, since the reducer with a relatively large diameter is located behind the joint of the gun arm, the effective depth of the gun arm is not reduced as in the conventional example, and the gun for a large work is not reduced. The output of the motor shaft and the electrode pressure transmitted to the electrodes are almost linearly related to the electric gun that can be applied to the power gun. Electrode pressure can be obtained. Wear and Gan'a - by wear of the beam deflection amount of change and the bearings, the electrode pressure is not affected. Further, since the displacement angle of the gun arm and the number of rotations of the electric motor are linearly proportional, the position of the electric gun can be easily controlled.

[Brief description of the drawings]

FIG. 1 is a side view of an electric gun according to the present invention.

FIG. 2 is a plan view thereof.

FIG. 3 is a side view of another embodiment of the electric gun according to the present invention.

FIG. 4 is a side view of still another embodiment.

FIG. 5 is a side view of still another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st gun arm 2,5,8,10 Electrode 3 Connecting part 4 2nd gun arm 6,6a, 6b Link 7 3rd gun arm 9 4th gun arm 12 Motor 13 Motor output shaft 14 Deceleration Machine 16 Swing lever 31 Roller 32 Groove 41, 42 Gear

Continuing on the front page (72) Inventor Hiroyuki Sakakura 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Shigeru Umeda 4-37 Ogami, Ayase City, Kanagawa Prefecture Ohara Co., Ltd. (72 ) Inventor Yoshio Sato 4-2-237 Ogami, Ayase-shi, Kanagawa Ohara Co., Ltd.

Claims (4)

[Claims] 1. An X-type electric welding machine comprising: a first and a second gun arm provided with electrodes opposed to each other at a tip thereof;
A third gun arm branched from the gun arm is formed, and a fourth gun arm extended from the second gun arm is formed, and a fourth gun arm is provided on an electrode provided at the tip of the third gun arm. A reduction gear is connected to an output shaft of an electric motor arranged rearward from a connection portion of the first and second gun arms with electrodes provided at a tip of the reduction gear, and a power transmission provided on an output side of the reduction gear. The second and fourth gun arms are rotated by a mechanism, and the power transmission mechanism is provided with an oscillating lever fixed to the output side of the speed reducer, between the lever and the second gun arm, or A link formed between the fourth gun arms, so that the output of the motor shaft and the electrode pressing force transmitted from the tip of the swing lever to the electrode via the link have a substantially linear relationship. The swing lever and the link are connected to the first and second gun arms. Third and upon pressurizing operation fourth Gan'a - AEG, wherein a beam is to perform the opening operation. 2. An X-type electric welding machine comprising a first gun arm and a first gun arm provided with opposing electrodes at a tip thereof.
Forming a third gun arm branched from the gun arm, and forming a fourth gun arm extending from the second gun arm or pivotally supported independently of the connecting portion so as to be rotatable;
The electrode provided at the tip of the fourth gun arm is opposed to the electrode provided at the tip of the third gun arm, and the speed is reduced to the output shaft of the electric motor arranged behind the connection between the first and second gun arms. The second and fourth gun arms are rotated by a power transmission mechanism provided on the output side of the speed reducer, and the power transmission mechanism is fixed to the output side of the speed reducer and is connected to the link. Swing lever provided with two parts, and each link formed between one link joint of the lever and the second gun arm and between the other link joint and the fourth gun arm. Connecting the oscillating lever and each link such that the output of the motor shaft and the electrode pressing force transmitted from the tip of the oscillating lever to the electrode via each link are substantially linear,
An electric gun wherein the third and fourth gun arms perform an opening operation when the first and second gun arms are pressurized. 3. An X-type electric welding machine comprising: a first and a second gun arm provided with electrodes opposed to each other at a tip thereof;
A third gun arm branched from the gun arm is formed, and a fourth gun arm extended from the second gun arm is formed, and a fourth gun arm is provided on an electrode provided at the tip of the third gun arm. A reduction gear is connected to an output shaft of an electric motor arranged rearward from a connection portion of the first and second gun arms with electrodes provided at a tip of the reduction gear, and a power transmission provided on an output side of the reduction gear. The second and fourth gun arms are rotated by a mechanism, and the power transmission mechanism includes a swing lever fixed to the output side of the speed reducer, and a groove or a groove provided in the swing lever. And the roller or groove provided in the second gun arm, and the output of the motor shaft and the tip of the swing lever are transmitted to the electrode via the roller or groove. The output of the motor shaft so that the electrode pressing force is in a substantially linear relationship,
The roller or the groove provided in the second gun arm is rotated by the rocking lever so that the electrode pressure transmitted from the tip of the rocking lever to the electrode via the roller or the groove is substantially linear. -Connected to the groove or roller at the tip of-and the first and second gun
An electric gun characterized in that the third and fourth gun arms perform an opening operation when the arm is pressurized. 4. An X-type electric welding machine comprising a first gun arm and a first gun arm provided with opposing electrodes at a tip thereof.
A third gun arm branched from the gun arm is formed, and a fourth gun arm extending from the second gun arm is formed, and a fourth gun arm is provided on an electrode provided at the tip of the third gun arm. A reduction gear is connected to an output shaft of an electric motor arranged rearward from a connection portion of the first and second gun arms with electrodes provided at a tip of the reduction gear, and a power transmission provided on an output side of the reduction gear. The second and fourth gun arms are rotated by a mechanism, and the power transmission mechanism comprises a gear fixed to the output side of the speed reducer and a gear provided on the second gun arm. The output is reduced so that the output of the motor shaft and the electrode pressing force transmitted from the gear fixed to the output side of the speed reducer to the electrode via the gear provided on the second gun arm have a substantially linear relationship. A gear fixed to the output side of the machine and a second gun arm Meshing a gear, and the first and second Gan'a - third and fourth Gan'a arm is at pressure operation - AEG, wherein a beam is to perform the opening operation.