JP2002224847A - X-type motor-driven welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-type motor-driven welding machine capable of reduc ing the spotting speed thereof, reducing the fluctuation in pressure, and appli cable to a gun for a large work by connecting a reduction gear to an output shaft of a motor. SOLUTION: In this X-type motor-driven welding machine with at least one gun arm 1 out of two gun arms having electrodes facing each other on their tips being turnably connected thereto, the reduction gear 7 is connected to the output shaft of the motor 8 disposed behind connection parts 6 of both gun arms, and the gun arm is turned by a link mechanism 3 and/or a cam mechanism provided on the output side 9 of the reduction gear.

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 in which at least one of two gun arms provided with electrodes facing each other at the tip is rotatably connected. The present invention relates to a rotating device of the arm.

[0002]

2. Description of the Related Art Conventionally, as an X-type electric welding machine for rotating a gun arm by rotation of an electric motor, a gear connected to an output shaft of the electric motor and an input side of a reducer provided on a pivot of the gun arm are used. It is generally known that a timing belt is arranged between connected gears and the gun arm is rotated by driving an electric motor, as disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 7-236981.

[0003]

However, the conventional X
In the rotating means of the gun arm of the electric electric welding machine, For the rotation of the gun arm, a timing belt is arranged between the gear connected to the output shaft of the electric motor and the gear connected to the input side of the reducer provided on the pivot of the gun arm. Therefore, the inertia moment value of the electric motor in terms of the shaft becomes large, and the acceleration / deceleration time when the electrode of the welding machine is opened and closed becomes long, so that the reduction of the hitting speed in the welding machine cannot be expected much. 2. In addition, since the timing belt is provided before the output is amplified by the speed reducer, there is a possibility that the welding force of the welding machine varies and the desired welding cannot be performed. 3. Further, since the speed reducer is provided at the pivot of the gun arm, the effective depth of the gun arm is reduced, which may hinder the application of the gun to a large work.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to connect a reduction gear to an output shaft of a motor so that the welding point of the welding machine can be improved. An object of the present invention is to provide an X-type electric welding machine which can reduce the speed, has less variation in the pressing force, and can be applied to a large work gun.

[0005]

In order to achieve the above object, an X-type electric welding machine according to the present invention comprises a reducer connected to an output shaft of an electric motor disposed behind a connecting portion of both gun arms, The gun arm is rotated by a link mechanism and / or a cam mechanism provided on the output side of the speed reducer.

[0006] The invention is characterized in that the speed reducer is held at a rear portion of a fixed arm.

[0007] Further, the reduction gear is held by a gun bracket that supports a connecting portion between the two gun arms.

[0008]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side view of a single-arm movable X-type electric welding machine according to the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a side view of a double-arm movable X-type electric welding machine, and FIG. FIG. 5 is a side view of another embodiment of a double-arm movable X-type electric welding machine, and FIG. 6 is a cross-sectional view of another embodiment of a double-arm movable X-type electric welding machine. FIG. 7 is a cross-sectional view of the transmission portion, FIG. 8 is a side view of another embodiment of a single-arm movable X-type electric welding machine, and FIG. 9 is a plan view thereof.

In FIGS. 1 and 2, reference numeral 1 denotes a movable gun arm which is one of the gun arms. An electrode 2 is attached to a tip of the arm 1 and an intermediate portion of the arm 1 is provided. A link 3 described later is connected to the upper part. Reference numeral 4 denotes a stationary gun arm, which is the other gun arm. An electrode 5 is also attached to the tip of the arm 4 so as to face the electrode 2, and an intermediate upper portion of the arm 4 is provided. Is pivoted on a shaft 6 together with the lower rear end of the arm 1 so that the arm 1 is
Is rotatable. An electric motor 8 having a thin reduction gear 7 is mounted on one side of the rear of the arm 4 so that the rear end of the arm 4 is connected to a wrist of a robot (not shown). Has become.

The output shaft 9 of the speed reducer 7 penetrates the arm 4, and the other side of the rear part of the arm 4 is formed of a plate, and a pin 10 is implanted at an eccentric position thereof. A core member 11 is arranged. One end of the link 3 is connected to the eccentric member 1.
1 is pivoted with a pin 10 and the other end of the link 3 is
It is pivoted by a pin 12 in the middle upper part of the system 1. Therefore, the eccentric member 11 and the link 3 constitute a link mechanism. Since the motor 8 is designed to rotate freely in the forward and reverse directions, the pin 10 performs an arc movement, and performs pressure welding work at both ends of the arc movement.

When the electric motor 8 rotates clockwise in the state shown in FIG. 1, the rotation is reduced to rotate the eccentric member 11 clockwise, and the movable gun arm 1 is pulled by the link 3 to open. I do. Then, when the pin 10 passes through the position A, the movable gun arm 1 is pushed by the link 3 to start the pressing operation. Due to this pressurizing operation, the electrode 2 approaches the work 13 and finally comes into contact with the work 13 to pressurize the work 13, and the welding work is performed in a state where the work 13 is pressurized at the position B. .

Next, the rotation of the electric motor 8 is converted in a counterclockwise direction. Due to this reversal, the pin 10 performs an arc movement toward the position A, and the movable gun arm 1 is pulled by the link 3 to perform the opening operation. Then, as the pin 10 approaches the position A, the deceleration of the movable gun arm 1 increases, and when the pin 10 passes the position A, the movable gun arm 1
Finally, the acceleration is increased by the link 3 to start the pressing operation. Due to this pressurizing operation, the electrode 2 approaches the work 13 and finally comes into contact with the work 13 to press the work 13, and the welding operation is performed with the work 13 pressed at the position shown in the figure. .

As described above, in the welding machine, after the rapid rotation of the electric motor 8 is immediately reduced by the speed reducer 7, the movable gun arm 1 is opened or closed via the link mechanism of the eccentric member 11 and the link 3. Since the pressure operation is performed, the inertia moment value in terms of the axis of the electric motor 8 is reduced, the acceleration / deceleration time when the electrode of the welding machine is opened and closed is shortened, and the shortening of the welding speed of the welding machine can be effectively expected. . Further, since the movable gun arm 1 is opened or pressurized by the power transmission mechanism after the output is amplified by the speed reducer 7, the welding force can be reduced with less variation in the pressing force by the electrode 2, and the desired welding can be performed. In addition, since the reducer 7 having a relatively large diameter is disposed behind the connecting portion (the pivot 6) of the gun arms 1 and 4, the effective depth of the gun arm is not reduced unlike the conventional example. Therefore, it is possible to apply the gun to a large work.

An electric motor 8 having a thin speed reducer 7 is mounted on one side of the rear part of the arm 4, and the rear end of the arm 4 is connected to a wrist of a robot (not shown). Thus, the present invention is applied to a single-arm movable X-type electric welding machine in which the arm 1 rotates.

Next, the embodiment shown in FIGS. 3 and 4 will be described. In this case, the same members as those in the previous embodiment are denoted by the same reference numerals, and description thereof may be omitted (the same applies hereinafter).

In the figure, reference numeral 21 denotes a gun bracket, which is connected to a wrist (not shown) of a robot. The bracket 21 has a reduction gear 7 connected to an output shaft of a motor 8. While being held, the pivots 6 of both gun arms 1 and 4 are held. The output shaft 9 of the speed reducer 7 is provided with an eccentric member 11 composed of a cam plate 22 and a plate and having a pin 10 implanted at an eccentric position. Also in this embodiment, since the electric motor 8 rotates alternately in the forward and reverse directions, the pin 10 performs an arc movement, and the pressure welding operation is performed at both ends of the arc movement.

When the electric motor 8 rotates clockwise in the state shown in FIG. 3, the movable gun arm 1 is pulled by the link 3 to perform an opening operation, and the rotation of the cam plate 22 causes the gun arm 4 to also open. Then, the movable gun arm 1 is pushed by the link 3 to start the pressurizing operation and the rotation of the cam plate 22 causes the gun arm 4 to start the pressurizing operation via the roller 23. By this pressing operation, the electrodes 2 and 5 approach the work 13, and finally, both electrodes 2 and 5 contact the work 13 to press the work 13, and at this position, the work 13 is pressed.
The welding work is performed in a state where the work 13 is pressed.

Next, the rotation of the motor 8 is converted in the counterclockwise direction. Due to this reversal, the pin 10 and the cam plate 22 perform an arc motion in the opposite direction, and the movable gun arm 1 is pulled by the link 3 to perform the opening operation and the cam plate 22.
The rotation of the gun arm 4 also performs the opening operation, the movable gun arm 1 is continuously pushed by the link 3 to start the pressing operation, and the rotation of the cam plate 22 causes the movement of the gun arm 4.
Also enters the pressurizing operation. With this pressing operation, the electrodes 2 and 5 approach the next work, and finally the electrodes 2 and 5 come into contact with the work and press the work, and the work is pressed at this position. Perform welding work.

The adjustment of the stroke due to the consumption of the electrodes 2 and 5 can be sufficiently coped with by adjusting the deflection angle of the pin 10, that is, the forward / reverse conversion position of the motor 8.
The shape of the cam plate 22 is such that when the pin 10 is at a desired deflection angle and the electrode 2 reaches the work 13, the electrode 5 on the arm 4 side is pulled up and the electrode 5 is moved to the work 13. At other times, the electrode 5 is pulled down so that the electrode 5 is separated from the work 13. Further, if the range of movement of the pin 10 is set to a range in which the pin 10 is reciprocated in the vicinity of the pressurized portion, the electrode can perform the pressurizing operation and the opening operation continuously with a small stroke.

In this embodiment, the arm 1 is turned by a link mechanism, and the arm 4 is turned by a cam mechanism.

Also, in this embodiment, similarly to the previous embodiment, the inertia moment value of the motor 8 in terms of the axis becomes smaller, and the acceleration / deceleration time when the electrode of the welding machine is opened / closed becomes shorter. It is possible to effectively reduce the hitting speed of the welding machine.
Further, since the gun arms 1 and 4 are opened or pressurized via the power transmission mechanism after the output is amplified by the speed reducer 7,
Since there is little variation in the pressure applied by the electrodes 2 and 5, desired welding can be performed, and the reducer 7 having a relatively large diameter is disposed behind the connecting portion (the pivot 6) of the gun arms 1 and 4. Thus, the gun can be applied to a large work without reducing the effective depth of the gun arm as in the conventional example.

Since the reduction gear 7 connected to the output shaft of the electric motor 8 is held by the bracket 21, it can be easily applied to a double-arm movable X-type electric welding machine in which both gun arms rotate. You can do it.

Next, the embodiment shown in FIG. 5 will be described. The embodiment of FIG. 5 is a modification of the embodiment of FIG.
Reference numeral 1 denotes a guide shaft for connecting between the tip of the link 3 and the movable gun arm 1 as one of the gun arms, and the guide shaft is guided by a linear guide 32 fixed to the speed reducer 7. The center of rotation 33 of the eccentric member 11 is almost always coincident with the center axis of the guide shaft 31. The lower rear end of the other gun arm 4 is regulated by a transformer 34 so that the rotation of the arm 4 is restricted.

The opening and pressurizing operations of the gun in this embodiment are substantially the same as those shown in FIG. 3 by the forward and reverse rotations of the electric motor. Since the center of rotation 33 of the shaft 11 and the center axis of the guide shaft 31 are substantially coincident with each other, the operation transmission from the eccentric member 11 to the movable gun arm 1 can be performed more reliably and accurately.

Next, the embodiment shown in FIGS. 6 and 7 will be described. In the figure, a link 3 is attached between a pin 10 implanted in an eccentric member 11 and a pivot 12 of one of the gun arms 1. An air cylinder 51 is disposed on the lower surface of the rear end of the gun arm 4.
The piston rod 52 from 1 penetrates through the gun arm 4, and a roller 53 at the tip thereof can contact the outer peripheral surface of the cam plate 22. 54 is an air compressor,
Compressed air from the air compressor 54 can be supplied to the air cylinder 21 via a pressure reducing valve 55.

In the X-type electric welding machine having the above-described structure, when the motor 8 is continuously rotated in a fixed direction with the electrodes 2 and 5 facing each other with the work 13 therebetween, the electric motor 8 The rotation of the output shaft is reduced by the speed reducer 7 to continuously rotate the eccentric member 11 clockwise in FIG. 6, for example. This rotation causes the cam plate 22 to rotate and the pin 10 eccentric to the shaft 9 to make a circular motion about the shaft 9, and the pin 10 from the cam plate 22 to the gun arm 4 via the piston rod 52. The rear end is moved up and down, and the circular motion converts the pivot 12 via the link 3 into an arc motion about the axis 6. Therefore, the electrodes 2 and 5 at the tips of the gun arms 1 and 4 perform a pressing operation and an opening operation.

Therefore, in the welding machine, the continuous rotating power in a certain direction by the electric motor 8 is converted by the eccentric member 11 into a movement for continuously performing the opening operation and the pressurizing operation of the gun arm 1, and Gun gun by cam plate 22
Since the opening operation and the pressurizing operation of the system 4 are converted into a continuous motion, the motor does not need to be stopped / started at the time of transition from the open position of the electrode to the pressurizing operation as in the conventional example. Since the motor 8 is continuously rotating, the rotation of the motor 8, that is, the movement of the electrodes 2, 5 is always in an accelerated state, and the electrode 2 from one welding by the electrodes 2, 5 to the next welding is , 5 can be shortened, and the power consumed when starting and stopping the electric motor 8 can be reduced. The adjustment of the stroke and the pressing force due to the consumption of the electrodes 2 and 5 can be sufficiently dealt with by the elastic force of the air in the cylinder 51.

Next, the embodiment shown in FIGS. 8 and 9 will be described. This embodiment is a modification of the embodiment shown in FIGS. 1 and 2. In the drawings, the upper middle part of the fixed gun arm 4 is pivoted on the shaft 6 together with the lower rear end of the movable gun arm 1 to form the arm 4. On the other hand, the arm 1 is rotatable. An electric motor 8 having a speed reducer 7 is mounted on one side of the rear of the arm 4, and the rear end of the arm 4 is connected to a wrist of a robot (not shown). ing.

The output shaft 9 of the speed reducer 7 penetrates the arm 4, and the other side of the rear part of the arm 4 is formed of a plate, and the pin 10 is implanted at an eccentric position thereof. A core member 11 is arranged. One end of a link holding member 62 in which an elastic body 61 such as a spring is inserted is pivotally mounted on an intermediate upper portion of the movable gun arm 1, and the link holding member 62 and the eccentric member 11 are connected to each other. Is connected by a link 3 to the pin 10.

In the X-type electric welding machine having the above-described configuration, when the electric motor 8 is continuously rotated in a certain direction while the lower electrode 5 is in contact with the work 13, the output of the electric motor 8 is obtained. The rotation of the shaft is reduced by the speed reducer 7 and the eccentric member 11
Is continuously rotated clockwise in FIG. 8, for example. Due to this rotation, the pin 10 at the eccentric position with respect to the shaft 9 makes a circular motion around the shaft 9, and this circular motion turns the pivot 12 through the link 3 into an arc motion about the shaft 6. Convert. Due to this arc movement, the electrode 2 at the tip of the gun arm 1 performs a pressing operation and an opening operation.

When the link 3 pushes the pivot 12 due to the circular motion of the pin 10, the electrode 2 descends and performs a pressurizing operation, and when the link 3 pulls the pivot 12, the electrode 2 ascends and performs an opening operation. In the vicinity of the end of the pressurizing operation, the electrode 2 comes into contact with the work 13, and from this position until the end of the pressurizing operation, the link 3 presses the elastic body 61 and is generated by the elastic body 61. A pressing force is applied to the electrode 2 via the gun arm 1, and a welding current is supplied in this pressurized state to perform a welding operation.

When the pressing operation of the electrode 2 by the link 3 is completed, the opening operation of the electrode 2 by the link 3 is started, and the compression of the elastic body 61 from the link 3 is first released.
Next, gun arm 1 is pulled by link 3 and work 1
The electrode 2 is retracted from the third side. During this opening operation, the entire gun is moved to bring the electrode 5 into contact with the next work. Then, the circular motion of the pin 10 causes the electrode 2 to perform the pressing operation continuously from the opening operation.

As described above, in the welding machine, the continuous rotating power in a certain direction by the electric motor 8 is converted by the eccentric member 11 into a movement for continuously performing the opening operation and the pressurizing operation of the gun arm 1. Therefore, the motor does not stop and start at the time of transition from the open position of the electrode to the pressurizing operation as in the conventional example, and the motor 8 is continuously rotating. By the operation 10, the movement from opening to pressurization of the electrode 2 is ideally decelerated and then accelerated irrespective of the position control controller. Therefore, the electrode 2
Thus, the time required for the electrode 2 to advance and retreat from one welding to the next welding can be shortened, and the consumption of electric power consumed when starting and stopping the motor 8 is reduced. The adjustment of the stroke due to the consumption of the electrodes 2 and 5 can be sufficiently dealt with by the presence of the elastic body 61.

[0034]

According to the present invention, the speed reducer is connected to the output shaft of the electric motor arranged behind the connection between the two gun arms,
Since the gun arm is rotated by a link mechanism and / or a cam mechanism provided on the output side of the speed reducer, the hitting speed of the welding machine is reduced, the pressure is less varied, and a large work is performed. X-type electric welding machine that can apply a gun to

When the speed reducer is held at the rear of the fixed arm, it can be applied to a single-arm movable X-type electric welding machine in which one of the gun arms rotates. It is.

In the case where the speed reducer is held by a gun bracket that supports a connecting portion between the two gun arms,
The present invention is applicable to an X-type electric welding machine that can move both arms so that both gun arms rotate.

[Brief description of the drawings]

FIG. 1 is a side view of a single arm movable X-type electric welding machine according to the present invention.

FIG. 2 is a plan view thereof.

FIG. 3 is a side view of a double arm movable X-type electric welding machine.

FIG. 4 is a sectional view of the transmission part.

FIG. 5 is a side view of another embodiment of a double arm movable X-type electric welding machine.

FIG. 6 is a side view of still another embodiment of a double arm movable X-type electric welding machine.

FIG. 7 is a sectional view of the transmission portion.

FIG. 8 is a side view of another embodiment of a single arm movable type X-type electric welding machine.

FIG. 9 is a plan view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 One gun arm 2, 5 electrode 3 Link 4 The other gun arm 6 Axis (connection part) 7 Reduction gear 8 Electric motor 9 Output shaft 11 Eccentric member 21 Gun bracket 22 Cam plate

Claims (3)

[Claims] An X-type electric welding machine in which at least one of two gun arms having electrodes opposed to each other at the tip thereof is rotatably connected to each other. A reduction gear is connected to an output shaft of a motor arranged rearward from a section, and a link mechanism provided on an output side of the reduction gear and / or
An X-type electric welding machine wherein the gun arm is rotated by a cam mechanism. 2. The X-type electric welding machine according to claim 1, wherein said speed reducer is held at a rear portion of a fixed arm. 3. An X-type electric welding machine according to claim 1, wherein said speed reducer is held by a gun bracket supporting a connecting portion between said two gun arms.