JP2000271754A - Resistance spot welding gun - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long life welding gun by arranging a stopper/bearing of a drive rod between a drive source and a rotary shaft so as to surely protect the drive source. SOLUTION: In a resistance spot welding device provided with a fixed arm 7 having one electrode 8, a moving arm 14 having the other electrode 15 corresponding to the above electrode, a drive source 1 having a drive rod 4 to drive the moving arm 14 and an equalize mechanism 21 fixed to a base 22, the drive rod and the moving arm are connected by a rotary shaft 20, a roller 17 fixed to the moving arm is engaged to a cam groove 11 so as to convert a reciprocating motion of the drive rod to a rotary motion of the moving arm, by the rotary shaft a stopper/bearing 23 of the drive rod is arranged between the drive source and the rotary shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fixed arm having one electrode, a movable arm having the other electrode corresponding to the electrode, and a driving rod for driving the movable arm. The present invention relates to a resistance spot welding gun having a drive source and an ecorise mechanism fixed to a base.

[0002]

2. Description of the Related Art Conventionally, in a resistance spot welding gun provided with the above-described apparatus, a driving rod and a movable arm are connected by a rotating shaft, and the reciprocating motion of the driving rod is moved by the rotating arm. One in which a roller fixed to a movable arm is engaged with a cam groove so as to convert the rotation into a rotating motion is known as disclosed in, for example, JP-A-10-58153.

[0003]

By the way, in the above-mentioned conventional example, the drive rod is not directly bearing, but the drive rod is extended and protruded toward the end cover side of the drive source, and is supported by the extended protrusion. When the welding source is pressurized, the couple generated on the drive rod affects the drive source side, and the positional relationship between the drive rod and the drive source is disturbed. -Leakage may occur, and even if an electric motor is used, the bearing on the rod cover side may be damaged.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to dispose a stopper / bearing for a drive rod between a drive source and a rotary shaft. By doing so, the drive source is reliably protected, and an attempt is made to provide a long-life welding gun.

[0005]

In order to achieve the above object, a resistance spot welding gun according to the present invention connects a driving rod and a movable arm by a rotating shaft, and reciprocates the driving rod by the rotating shaft. A roller fixed to the movable arm is engaged with the cam groove so as to convert the rotation into a rotating motion of the movable arm, and a stopper / bearing of the drive rod is provided between the drive source and the rotary shaft. It is characterized by being arranged.

Further, one end of a guide shaft of the ecorise mechanism fixed to the base is fixed to a fixed arm, and the other end is fixed to the drive source.

Further, the stopper / bearing is adjusted and held by a position adjusting device provided in an ecorise mechanism.

Further, the driving source flows the second piston.
It is characterized by comprising a two-staged stroke cylinder.

Further, the drive source is characterized by comprising an electric motor and a conversion device for converting a rotary motion of the motor into a reciprocating motion of a drive rod.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. In the drawing, reference numeral 1 denotes an air cylinder serving as a driving source, in which pistons 2 and 3 and a piston rod serving as a driving rod 4 fixed to these pistons are arranged. The tip 5 extends forward (upward in FIG. 1) through the front wall 6 of the air cylinder of the drive source 1.

Reference numeral 7 denotes a fixed arm. An electrode 8 is attached to the tip of the fixed arm 7.
The base 9 of the system 7 is fixed to the front wall 6 of the air cylinder of the drive source 1 via an insulating material 10. A cam plate 12 having a cam groove 11 is fixed to both sides of the base 9 of the fixing arm 7. One end of a power supply member 13 is connected to an end of the base 9 of the fixed arm 7.

Reference numeral 14 denotes a movable arm, and the movable arm 1
An electrode 15 corresponding to the electrode 8 is attached to the distal end of 4, and a roller 17 that engages with the cam groove 11 is attached below the base 16 of the movable arm 14. At the same time, the other power supply member 1
8 are connected.

The distal end 5 of the driving rod 4 and the lower end 19 of the base 16 of the movable arm 14 are connected by a rotating shaft 20. Both ends of the rotating shaft 20 are engaged with the cam grooves 11.

Reference numeral 21 denotes an ecorise mechanism fixed to a base 22, and reference numeral 23 denotes a member disposed between the drive source 1 and the rotary shaft 20 to serve as a stopper and bearing for the drive rod 4. The stopper / bearing 23 is held by the ecorise mechanism, and engages with a restricting pin 24 provided on the drive rod 4.

The drive source 1 is not limited to an air cylinder of the type described above, but may be a
It is also possible to use a device comprising a stepped stroke cylinder or an electric motor and a conversion device for converting the rotational motion of the motor into a reciprocating motion of the drive rod. The base 22 may be a robot arm instead of a fixed one.

In the resistance spot welding gun having the above configuration, in the state shown in FIG. 1, a work is sandwiched between the electrodes 8 and 15 and pressure welding is performed. At this time, the reaction force of the pressing force by the electrode 15 on the movable arm 14 tends to move the roller 17 to the left and the rotating shaft 20 to the right in FIG. As a result, a couple is generated at the tip 5 of the drive rod 4.
However, since this couple is absorbed by the stopper / bearing 23 which is disposed between the drive source 1 and the rotating shaft 20 and is held by the equalizing mechanism 21 and is prevented from rotating, the tip of the drive rod 4 Although a couple is generated in the section 5, the drive source 1 is not particularly affected.

When the pressure welding operation using the electrodes 8 and 15 is completed, the drive rod 4 is moved upward in FIG. 1 by the drive source 1, and the rotary shaft 20 and the roller 17 are moved along the cam groove. Move along 11 and move arm 14
Performs an opening operation. When the restricting pin 24 provided on the drive rod 4 comes into contact with the stopper / bearing 23, the movement of the drive rod 4 is stopped, and the movable arm is moved.
The opening operation of the program 14 ends. When the movable arm 14 is opened, the stopper / bearing 23 cooperates with a guide shaft 25 of the later-described equalizing mechanism 21 to perform a function of preventing the gun from rotating against the equalizing mechanism 21.

A guide shaft 25 is provided on the ecorizing mechanism 21 fixed to the base 22, and the gun can be ecologically guided by the guide shaft 25. One end of the shaft 25 is At the base 9 of the fixed arm 7,
The other end is fixed to the lower portion of the drive source 1, respectively.
It is made to increase rigidity. Reference numeral 26 denotes a spring provided in the ecorise mechanism 21, and the gun is supported by the ecorise mechanism 21 by the spring 26.

As a device for holding the stopper / bearing 23 by the above-mentioned ecorize mechanism 21, a screw 2 is provided at the lower part.
7 having an upper end fixed to a stopper / bearing 23, an adjusting rod 28 and a nut 29 screwed to a screw 27 of the adjusting rod 28, which is locked to the eco-rise mechanism 21. It is.

By rotating the nut 29 of the position adjusting device, the position of the stopper / bearing 23 with respect to the ecorise mechanism 21 is adjusted and held. As a result, the restricting pin 24 provided on the drive rod 4 and the stopper The distance between the double bearings 23 can be adjusted and the movable arm 14 can be opened.
Can be easily changed.

FIG. 4 shows an air cylinder which is a driving source 1 according to the present invention, which is constituted by a two-stage stroke cylinder in which a second piston is floated. In the same manner as in the first embodiment, pistons 2 and 3 and a piston rod, which is a drive rod 4 fixed to these pistons, are disposed. It extends forward through the front wall 6. Further, a second piston 30 is further disposed in the drive source 1, and the second piston 30
When the piston 3 is lowered by supplying compressed air from the air supply port 31 (the state shown in FIG. 4), the rising stroke of the piston 3 when the piston 3 is raised (when the movable arm 14 is opened). And the movable arm 14 is also small
Can be activated by The remaining configuration is substantially the same as that of the first embodiment, and the same reference numerals are given to the drawings and the description thereof will be omitted.

FIG. 5 shows an example in which a drive source 1 according to the present invention comprises an electric motor and a converter for converting the rotational motion of the motor into a reciprocating motion of a drive rod. Is an electric motor, and an output side of the electric motor 40 is provided with a drive rod 4 for rotating the motor.
For example, a conversion device 41 including a well-known ball screw and nut for converting the reciprocating motion is provided. This drive source 1
In the case of applying the movable arm 14, by controlling the supply of electric current to the electric motor 40,
The opening operation can be performed with the lock. In the case of this embodiment, the remaining structure is substantially the same as that of the first embodiment.

[0023]

According to the first aspect of the present invention, there is provided a resistance spot welding gun having a fixed arm having one electrode, a movable arm having the other electrode corresponding to the electrode, and a movable arm having the other electrode. In a resistance spot welding gun provided with a driving source having a driving rod for driving the motor, and an ecorise mechanism fixed to a base, the driving rod and a movable arm are connected by a rotating shaft, and driven by the rotating shaft. A roller fixed to the movable arm is engaged with a cam groove so as to convert a reciprocating movement of the rod into a rotating movement of the movable arm, and the driving rod is provided between the driving source and a rotating shaft. Since the stopper / bearing is disposed between the drive source and the rotary shaft, the couple generated at the drive rod at the time of welding pressurization is absorbed by the bearing, and the couple is applied to the drive source. The drive source is protected without any influence of force Precisely the welding gun operated long life.

According to the present invention, one end of the guide shaft of the ecorise mechanism fixed to the base is fixed to the fixed arm and the other end is fixed to the drive source, so that the rigidity of the guide shaft is increased. Therefore, the eco rise operation of the gun becomes smooth.

In the third aspect of the present invention, the stopper / bearing is adjusted and held by a position adjusting device provided in the eco-rize mechanism. Adjustment of the opening amount and the amount of eco-rise can be easily performed, and the rotation of the gun body with respect to the eco-rise mechanism can be effectively prevented.

In claim 4, the driving source is the second
In the case of a two-stage stroke cylinder with a floating piston, the movable arm can be operated with a small stroke, and the welding gun can improve work efficiency.

According to a fifth aspect of the present invention, when the drive source comprises an electric motor and a conversion device for converting the rotational motion of the motor into a reciprocating motion of the drive rod, the open arm of the movable arm is provided. -It is a welding gun that can adjust the work freely and can further improve the work efficiency.

[Brief description of the drawings]

FIG. 1 is a side view of a partial cross section of a resistance spot welding gun according to the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a front view of FIG. 1;

FIG. 4 is a side view of a partial cross section of a main part of another embodiment.

FIG. 5 is a side view of a partial cross section of a main part of still another embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 drive source 4 drive rod 7 fixed arm 8, 15 electrode 11 cam groove 14 movable arm 17 roller 20 rotating shaft 21 ecorise mechanism 22 base 23 stopper / bearing 25 guide shaft 28, 29 position adjusting device 30 2nd piston 40 electric motor 41 converter

Claims (5)

[Claims] 1. A fixed arm having one electrode, a movable arm having the other electrode corresponding to the electrode, a drive source having a drive rod for driving the movable arm, and a base In the resistance spot welding gun provided with an ecorise mechanism fixed to the moving rod, the driving rod and the movable arm are connected by a rotating shaft, and the reciprocating motion of the driving rod is rotated by the rotating shaft. A roller fixed to a movable arm is engaged with a cam groove so as to convert the driving arm into a cam groove, and a stopper / bearing of the driving rod is arranged between the driving source and a rotating shaft. Spot welding gun. 2. The resistance spot welding according to claim 1, wherein one end of a guide shaft of the ecorise mechanism fixed to the base is fixed to the fixed arm, and the other end is fixed to the drive source. gun. 3. The resistance spot welding gun according to claim 2, wherein the stopper / bearing is adjusted and held by a position adjusting device provided in an ecorise mechanism. 4. The resistance spot welding gun according to claim 1, wherein said drive source comprises a two-stage stroke cylinder in which a second piston is floated. 5. A resistor according to claim 1, wherein said drive source comprises an electric motor and a converter for converting a rotary motion of said motor into a reciprocating motion of a drive rod. Spot welding gun.