JPH079159A - C type welding gun - Google Patents

Abstract

PURPOSE:To provide the C type welding gun where the driving force of a motor is reduced and each arm is controlled accurately by making both arms movable for the motor. CONSTITUTION:In the C type welding gun, both movable arms 4 and 5 are arranged slidably, respectively on the housing 3 on which the motor 2 fixed on a manipulator arm 1 is held, one movable arm 4 is advanced and retreated by rotation of an output shaft 6 of the motor and the other movable arm 5 is advanced and retreated by rotation of a driving shaft 10 via a driving mechanism 12 from the output shaft. Clutches 20 and 21 are interposed, respectively in the output shaft and the driving shaft, touch sensors 17 and 19 to works are provided, respectively on both movable arms and the clutches of the output shaft or the driving shaft are released according to signals from the touch sensors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a movable armature driven by an electric motor connected to a manipulator arm of a robot or the like.
The present invention relates to a C-type welding gun having a frame.

[0002]

2. Description of the Related Art Conventionally, a C-type welding gun having a movable arm driven by a pressure cylinder connected to a manipulator arm of a robot or the like is known as shown in FIG. -See 243278). That is, 31
Is an equalizing unit attached to a manipulator arm 32 of a robot or the like, and a fixing arm 34 fixed to a pressure cylinder 33 is slidably attached to the equalizing unit 31. An electrode 35 is attached to the tip of the arm.

An electrode 38 is attached to a movable arm 36 provided on the pressure cylinder 33 via a shank 37. In addition, the piston 39 of the pressurizing cylinder 33 has a rod 40 on the side opposite to the movable arm 36.
The rod 40 extends rearward from the pressure cylinder 33 and has teeth 41. Further, teeth 42 are formed on the fixed arm 34 at positions facing the teeth 41, and a power transmission gear 43 is arranged between the teeth 41 and 42. A shaft 44 of the gear 43 is supported between shaft holding plates 48 and 49 fixed to a cylinder 47 arranged between both walls 45 and 46 of the equalizing unit 31.

In the C-type welding gun having the above-mentioned structure, the gun is brought closer to the work 50 by the manipulator arm 32 so that the work 50 is located between the electrodes 35 and 38. Then, a pressurized fluid is inserted into the chamber 51 of the cylinder 47 to bring the piston rods 52 and 53 into contact with the walls 45 and 46 of the equalizing unit 31 to fix the cylinder 47, thereby fixing the shaft 44 of the gear 43. At the same time, a pressurized fluid is inserted into the chamber 54 of the pressure cylinder 33 to move the movable arm 36 forward. The rod 40 also moves forward as the movable arm 36 moves forward, but the movement of the rod 40 is transmitted to the fixed arm 34 via the tooth 41, the gear 43, and the tooth 42, and the fixed arm 34 moves. Is moved in the opposite direction in synchronization with the movement of the rod 40. Therefore, electrodes 35 and 38 are forced to approach work 50 at the same time.

When the fluid pressurization of the chamber 51 in the cylinder 47 is released at a position where the electrodes 35 and 38 are close to the work 50, the cylinder 47 becomes free with respect to the equalizing unit 31 and the shaft 44 of the gear 43. The fixed armature is released, and the movable arm 36 and the fixed arm 34 can be arbitrarily moved. Therefore, after both electrodes 5 and 6 approach the work at the same time, both the electrodes move arbitrarily and come into contact with the work 50 to sandwich the work. In this sandwiched state, the welding current may be supplied to weld the work 50.

[0006]

However, even in the case of the above-mentioned conventional example, since both arms 34 and 36 simultaneously approach the work 50, the welding can be speeded up, but the movement of the fixed arm 34 is moved. Since the pressurizing cylinder 33 accompanies this, the moving weight becomes heavy and the driving force in the cylinder is excessively required, and depending on the initial position of each electrode 35, 38 with respect to the work 50, the shaft 44 of the gear 43 is There is a problem that it is difficult to set the release time and the control cannot be performed accurately.

The present invention has been made in view of the above problems of the prior art. The object of the present invention is to make both arms movable with respect to the electric motor. An object of the present invention is to provide a C-type welding gun in which the driving force can be reduced and each arm can be accurately controlled.

[0008]

In order to achieve the above object, a C-type welding gun according to the present invention is arranged such that both movable arms are slidably arranged in a housing fixed to a manipulator arm and holding an electric motor. C-type welding comprising one movable arm that moves forward and backward by the rotation of the output shaft of the electric motor, and the other movable arm that moves forward and backward by the rotation of the drive shaft from the output shaft via the transmission mechanism. A gun, in which a clutch is provided on each of the output shaft and the drive shaft, and a touch sensor for each work is provided on each of the movable arms, and the output shaft or the drive shaft is driven by a signal from the touch sensor. The feature is that the clutch of the shaft is opened.

[0009]

In the C-type welding gun constructed as described above, it is slidably arranged in the housing by driving the electric motor while the electrodes are positioned on both sides of the work by the manipulator arm. When both movable arms approach the work at the same time, and the electrode on either side of the two moveable arms contacts the work, the contact of the electrodes with the work A touch sensor provided on the movable arm detects changes in the acceleration of the movable arm. The signal from the touch sensor causes the electrode to come into contact with the work.
The clutch on the arm side is released to stop the movement of the arm. Meanwhile, the arm on the side where the electrode is not in contact with the work continues to move, the electrode approaches the work, and finally, the electrode also contacts the work and the work is performed. Pressurize.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. In the figure, 1 is a manipulator such as a robot.
A manipulator arm 1 has a housing 3 fixed to a manipulator arm 1 to which an electric motor 2 as a pressurizing device is fixed, and the housing 3 is provided with vertically movable arms 4 and 5, respectively. It is arranged slidably.

The movable arm 4 located at a position facing the electric motor 2 in the upper part of the housing 3 is provided with a nut 8 screwed into a screw portion 7 of an output shaft 6 of the electric motor 2. The nut 8 is fixed to the end of the movable arm 4.

A pulley 9 is fixed to the output shaft 6, and a belt 12 is wound around the pulley 11 fixed to the lower drive shaft 10. A nut 14 fixed to the end of the movable arm 5 is arranged on the screw portion 13 of the drive shaft 10.

Further, the movable arm 4 has a touch sensor 17 for detecting that the electrode 15 is in contact with the work 16, for example, by a change in the acceleration of the arm, and the movable arm 5 also has a touch sensor 17.
Are provided with touch sensors 19 for detecting that the electrodes 18 are in contact with the work 16, respectively.
17 is a brake clutch 20 provided on the output shaft 6,
The touch sensor 19 controls the braked clutch 21 provided on the drive shaft 10.

In the C-type welding gun as described above, the electrodes 15, 1 are provided on both sides of the work 16 by the manipulator arm 1.
8 is positioned, the output shaft 6 is rotated by driving the electric motor 2, and the nut portion 8 is rotated by the screw portion 7.
The movable arm 4 slidably arranged in the housing 3 moves toward the work 16 by advancing, and the rotation of the output shaft 6 rotates the drive shaft 13 via the belt 12. By moving the nut 14 forward by the screw portion 13, the movable arm 5 slidably arranged in the housing 3 also moves toward the work 16.

When the electrode 15 or 18 comes into contact with the work 16, for example, when the electrode 15 comes into contact with the work 16, the acceleration of the movable arm 4 changes, so that the touch sensor 17 is connected to the electrode 15. The contact with the work 16 is sensed, and this signal is sent to the clutch 20 to open the clutch 20. Therefore, the movement of the movable arm 4 from the output shaft 6 of the electric motor 2 via the clutch 20 is stopped, but the clutch 2
Since 1 is still in the closed state, the rotation of the output shaft 6 of the electric motor 2 to the drive shaft 10 via the belt 12 is transmitted to the clutch 21.
Through the screw portion 13 and the nut 14, the electrode 18 on the movable arm 5 side is continuously brought close to the work 16, and finally the electrode 18 also comes into contact with the work 16 to press the work. .

The original electrodes 1 for the work 16
Depending on the positions of the electrodes 5 and 18, the electrode 18 may first come into contact with the work 16. In this case, touch sensor-1
9 operates to stop the movement of the movable arm 5 and continue the movement of the movable arm 4.

[0017]

According to the present invention, since both movable arms are slidably arranged in the housing which is fixed to the manipulator arm and holds the electric motor, there are few moving parts for welding and the weight can be reduced. It is possible to reduce the driving force of the electric motor.

Further, C is composed of one movable arm which is moved forward and backward by the rotation of the output shaft of the electric motor and the other movable arm which is moved forward and backward by the rotation of the drive shaft from the output shaft via the transmission mechanism. Type welding gun, wherein the output shaft and the drive shaft each have a clutch interposed therebetween and the movable armature
Each arm is provided with a touch sensor for the work, and the clutch of the output shaft or the drive shaft is released by the signal from the touch sensor, so both arms can be brought close to the work quickly. As a matter of course, the movement of the electrodes can be accurately controlled without being influenced by the initial position of each electrode.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a main part of a C-type welding gun according to the present invention.

FIG. 2 is a side view of a conventional C-type welding gun.

[Explanation of symbols]

 1 Manipulator arm 2 Electric motor 3 Housing 4,5 Movable arm 6 Output shaft 10 Drive shaft 12 Transmission mechanism 17,19 Touch sensor 20,21 Clutch

Claims (1)

[Claims] 1. A movable arm, which is fixed to a manipulator arm and holds an electric motor, is slidably disposed in the housing, and one movable arm that moves forward and backward by rotation of an output shaft of the electric motor and the movable arm. A C-type welding gun consisting of the other movable arm which moves forward and backward by the rotation of the drive shaft from the output shaft via a transmission mechanism, wherein a clutch is interposed between the output shaft and the drive shaft and both of the movable arms are movable. A C-type welding gun, wherein each arm is provided with a touch sensor for a work, and a clutch of the output shaft or the drive shaft is opened by a signal from the touch sensor.