JPH06344150A - Stud welding equipment - Google Patents

Abstract

PURPOSE:To prevent the excessive force from being imposed on a robot main body supporting part and to improve its durability by diminishing angular moment in the same direction as the angular moment due to the weight of an elevating and lowering arm by an energizing joint to join a traveling frame side power feeding path to a robot main body side power feeding path. CONSTITUTION:When a stud welding gun 4 is directed to the front in the X-axis direction and works are pressurized from the rear in the X-axis direction to perform welding, the clockwise angular moment is acted on a robot main body 31 by pressurization reaction. The robot main body 31 is inclined to tilt clockwise for a traveling frame 30 coupled with the clockwise angular moment due to the weight of the elevating and lowering arm 32 and the excessive force is imposed on the supporting part of the robot main body 31. However, the anticlockwise angular moment is allowed to act on the robot main body 31 by pressure welding reaction to a power feeding bar 55 of a contact member of the energizing joint. As a result, the clockwise angular moment by the pressurization reaction of the works is diminished and the excessive force is not imposed on the supporting part of the robot main body 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stud welding apparatus using a Cartesian coordinate type robot.

[0002]

2. Description of the Related Art Conventionally, a traveling frame is provided so as to be movable in the X-axis direction by straddling guide frames on both sides in the Y-axis direction with two horizontal directions as the X-axis and the Y-axis, and the traveling frame in the Y-axis direction. A robot body movably supported by the robot body and a vertically-longitudinal lifting arm supported by the robot body so as to be vertically movable. A stud welding gun is attached to the lower end of the lifting arm via the wrist. There is known a stud welding device in which the above is attached (see Japanese Utility Model Laid-Open No. 62-109884). In this structure, a multi-joint type power feeding member that moves following the robot body is attached to the traveling frame, and power is supplied to the spot welding gun from the power feeding member via a power feeding path provided in the robot body and the lifting arm. I have to.

[0003]

In the above, the elevating arm is supported by the robot body so as not to interfere with the traveling frame while being separated from the traveling frame in one direction in the X-axis direction. A rotational moment around the Y-axis acts on the robot body, and particularly when the stud welding gun is directed in the X-axis direction and the workpiece is pressed from the other side in the X-axis direction, the robot body is moved by the pressure reaction force through the lifting arm. A rotation moment in the same direction as the above-mentioned rotation moment acts on the support portion of the robot main body with respect to the traveling frame. In view of the above points, the present invention receives a part of the rotational moment acting on the robot main body by using the power feeding mechanism between the traveling frame and the robot main body, and the support portion of the robot main body with respect to the traveling frame is not overpowered. It is an object of the present invention to provide a stud welding device having such a structure.

[0004]

[Means for Solving the Problems] In order to achieve the above object,
INDUSTRIAL APPLICABILITY According to the present invention, a traveling frame provided movably in the X-axis direction across two guide frames on both sides in the Y-axis direction with two horizontal directions as the X-axis and the Y-axis, and the traveling frame is movable in the Y-axis direction. The lower end of the elevating arm of the Cartesian coordinate type robot comprising a robot main body supported by a robot A stud welding device in which a stud welding gun is attached to the wrist via a power supply path provided in each of the traveling frame, the robot body, and the elevating arm. The power supply path to be provided is composed of a power supply bar that is fixed to the traveling frame and is long in the Y-axis direction, and the robot body is provided with a power supply joint that connects the power supply path on the robot body side to the front power supply bar. The contact member and the cylinder for contacting and separating the contact member to and from the power feeding bar are arranged, and the pressing direction of the contact member with respect to the power feeding bar is opposite to the rotational moment about the Y-axis acting on the robot body by the weight of the lifting arm. It is characterized in that the rotational moment in the direction is set in such a direction that it acts on the robot body by the pressure contact force of the contact member.

[0005]

The robot main body is moved to a predetermined position in the Y-axis direction with the contact member of the current-carrying joint separated from the power supply bar, and then the contact member is pressed against the power supply bar by the cylinder, and then the work piece is fixed with the stud welding gun. Pressurization is performed and power is supplied to the welding gun to perform stud welding.
Here, when the work is pressed from the other side in the X-axis direction, the rotation moment due to the pressurizing reaction force in the same direction as the rotation moment due to the weight of the lifting arm acts on the robot body via the lifting arm. This is offset by the rotational momentum in the opposite direction acting on the robot body due to the pressure contact reaction force of the contact member with respect to the robot body, and the support portion of the robot body against the traveling frame is not overpowered.

[0006]

1 to 3, reference numeral 1 is a jig unit for setting a work, 2 is a ceiling frame installed above an arrangement portion of the jig unit 1, and the ceiling frame 2 has a rectangular coordinate type. A robot 3 is mounted, a stud welding gun 4 is attached to the robot 3, and stud welding of a work is performed.

The jig unit 1 is constructed by mounting a pair of jigs 11 and 11 on a turntable 10. When the turntable 10 is rotated 180 °, both jigs 11 and 11 are positioned at the front work set position. And the work welding position on the back side can be rotated alternately.

The robot 3 has guide frames 20 on the girders on both sides of the ceiling frame 2 in the Y axis direction, where the depth direction of the ceiling frame 2 is the X axis direction, the width direction is the Y axis direction, and the vertical direction is the Z axis direction. ,
A traveling frame 30 that is movably provided in the X-axis direction across 20
And a robot main body 31 movably supported on the traveling frame 30 in the Y-axis direction, and a longitudinal elevating and lowering unit in the Z-axis direction supported by the robot main body 31 so as to be spaced forward and downward with respect to the traveling frame 30 in the X-axis direction. The arm 32 and the stud welding gun 4 are attached to the lower end of the elevating arm 32 via a wrist 33 having two degrees of freedom of a vertical U-axis and a horizontal V-axis, and are in a welding position. The work on the jig 11 is attached to the wrist 33
By changing the posture of the stud welding gun 4 depending on the movement of the stud welding gun, stud welding can be performed from any direction.

The traveling frame 30 is slidably supported on a guide rail 30a fixed to the upper surface of each guide frame 20 via a pair of linear guides 30b attached to each end of the traveling frame 30. The pinion 30c connected to the X-axis motor Mx mounted on the traveling frame 30 is engaged with the rack 30d fixed to the inner surface of each guide frame 20 to drive the traveling frame 30 in the X-axis direction. A pair of guide rails 31a are fixedly provided on the upper surface and the lower front surface of the traveling frame 30, and the robot main body 31 is slidably mounted on the guide rails 31a via linear guides 31b attached to the rear surface thereof. Y axis motor My supported and mounted on the robot body 31
The pinion 31c connected to the robot frame 31 is meshed with the rack 31d fixed to the upper part of the front surface of the traveling frame 30.
Was driven in the Y-axis direction. Also, the lifting arm 3
2 is slidably supported by a pair of guide rails 32a on the rear surface thereof on a linear guide 32b fixed to the front surface of the robot body 31, and a pinion 32c connected to a Z-axis motor Mz mounted on the robot body 31. Is engaged with a rack 32d fixed to the rear surface of the elevating arm 32 to drive the elevating arm 32 in the Z-axis direction. Further, the elevating arm 32 is equipped with a U-axis motor Mu and a V-axis motor Mv. Then, the wrist 33 is driven around the U axis and around the V axis.

In the figure, reference numeral 5 denotes a transformer arranged on the side of the jig unit 1. One output terminal of the transformer 5 is a cable 50 and an energizing joint 51 provided on the jig unit 1.
And the other output terminal of the transformer 5 is connected to the power supply path and the wrist 33 which are provided in the cable 52, the traveling frame 30, the robot body 31, and the lifting arm 32, respectively. It is connected to the stud welding gun 4 through the provided U-axis and V-axis joints 53 and 54, and the work is pressed between the gun 4 and the jig 11 while the work is being pressed by the gun 4. The stud welding was carried out by energizing through.

Here, the power feeding path provided in the traveling frame 30 is composed of a feeding bar 55 fixed to the lower surface of the traveling frame 30 and having the one end connected to the cable 52 and long in the Y-axis direction. As shown in FIGS. 4 and 5, the provided power supply path 56 is connected to the power supply bar 55 via the first power supply joint 57 provided at the lower rear portion of the robot body 31, and the power supply path 56 is connected to the lifting arm 32. It was connected to a power supply bar 58, which is long in the Z-axis direction and constitutes an arm-side power supply path fixed to the side surface, via a second power supply joint 59 provided on the front side of the robot body 31. Each energizing joint 5
7, 59 are ounce copper plates 57a at each end of the power supply path 56,
Contact members 57b, 59 connected via 59a
b and the contact members 57b and 59b for each power feeding bar 5
5 and 58, and cylinders 57c and 59c that come into contact with and separate from each other.
It was attached to the brackets 57d and 59d fixed to the No. 1 unit.
In addition, the contact member 57 of each energizing joint 57, 59
b and 59b are connected to the piston rods of the cylinders 57c and 59c via ball joints 57e and 59e, as shown in FIG. Here, the contact member 57b of the first energizing joint 57 is adapted to come into pressure contact with the power feeding bar 55 on the lower surface of the traveling frame 30 from below.
Due to the pressure contact reaction force of 7b, a rotation moment about the Y axis in the counterclockwise direction in FIGS. 3 and 5 acts on the robot body 31 with the lower linear guide 31b as a fulcrum.

At the time of stud welding, the traveling frame 30, the robot body 31, and the elevating arm 32 are driven while the contact members 57b and 59b of the energizing joints 57 and 59 are separated from the power feeding bars 55 and 58. The gun 4 is moved in three directions orthogonal to the X-axis, Y-axis, and Z-axis, and the wrist portion 33 is driven to change the posture of the stud welding gun 4, and the gun 4 is moved to each predetermined striking position of the work. They are made to face each other from a predetermined direction, and then each energizing joint 57, 5
9 of the contact members 57b and 59b to the cylinders 57
By the operation of c and 59c, they are brought into pressure contact with the respective power supply bars 55 and 58,
Next, the stud welding gun 4 is abutted against the hitting position of the work by the operation of the pressurizing cylinder of the gun to apply pressure, and the gun 4 is supplied with power to perform stud welding.

By the way, when the stud welding gun 4 is directed downward as shown in FIG. 3 or directed rearward in the X-axis direction as indicated by, and welding is performed by pressurizing the work from above or from the front side in the X-axis, the pressure counteracts. A counterclockwise rotation moment acts on the robot body 31 by the force via the elevating arm 32. This rotation moment is offset by the clockwise rotation moment acting on the robot body 31 due to the weight of the elevating arm 32, and the robot travels. Robot body 3 for frame 30
The guide rail 30a and the linear guide 30 which are the supporting portions of
There is no overload on b.

On the other hand, when the stud welding gun 4 is directed forward in the X-axis direction as shown in FIG. 3 and the work is pressed from the rear in the X-axis direction for welding, the reaction force is applied to the robot body 31 in the clockwise direction. The rotation moment acts on the robot main body 31 in a clockwise direction with respect to the traveling frame 30 in combination with the clockwise rotation moment due to the weight of the elevating arm 32, and the support portion of the robot main body 31 is overloaded. However, in the present embodiment, as described above, the rotational moment in the counterclockwise direction acts on the robot body 31 due to the pressure contact reaction force of the contact member 57a of the first energizing joint 57 to the power feeding bar 55, and this rotational moment causes the workpiece to rotate. The rotational moment in the clockwise direction due to the pressure reaction force is reduced, so that the support portion of the robot body 31 is not forced.

In the above embodiment, the contact member 57a is pressed into contact with the power feeding bar 55 fixed to the lower surface of the traveling frame 30 from below, but the contact member 57a is located below the guide rail 31a on the front surface of the traveling frame 30. Fix the power supply bar,
A contact member may be pressed against this from the front so that a counterclockwise rotation moment due to the pressure reaction force acts on the robot body 31.

[0016]

As is apparent from the above description, according to the present invention, the spot welding gun pressurizes and reverses the work by means of the current-carrying joint connecting the power feeding path on the traveling frame side and the power feeding path on the robot body side. The rotation moment in the same direction as the rotation moment due to the weight of the lifting arm, which acts on the robot body by the force, can be reduced, and the support portion of the robot body for the traveling frame is not overloaded, and the durability is improved.

[Brief description of drawings]

FIG. 1 is a front view of an example of the device of the present invention.

[Figure 2] Plan view

[Figure 3] Side view

FIG. 4 is an enlarged front view of the main part.

5 is a side view taken along the line V-V of FIG.

6 is an enlarged sectional view taken along line VI-VI of FIG.

[Explanation of symbols]

3 Robot 4 Stud welding gun 20 Guide frame 30 Travel frame 31 Robot body 32
Lifting arm 33 Wrist 55 Power supply bar 57
Energizing joint 57b Contact member 57c
Cylinder

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Egawa 1-10-1 Shin-Sayama, Sayama-shi, Saitama Prefecture Honda Engineering Co., Ltd. (72) Inventor Tomohiko Yashiro 1-10-1 Shin-Sayama, Sayama-shi, Saitama Prefecture Within Da Engineering Co., Ltd.

Claims (1)

[Claims] 1. A traveling frame provided so as to be movable in the X-axis direction while straddling guide frames on both sides in the Y-axis direction with two horizontal directions as the X-axis and the Y-axis, and the traveling frame is moved in the Y-axis direction. A robot body that is freely supported, and an X-axis with respect to the traveling frame on the robot body.
A stud welding device comprising a Cartesian coordinate type robot having a vertically elevating arm vertically supported in a vertically spaced manner in one axial direction and having a stud welding gun attached to the lower end of the elevating arm via a wrist. In the case of supplying power to the stud welding gun through the power supply paths provided in the traveling frame, the robot body, and the lifting arm, respectively, a power supply bar provided in the traveling frame is fixed to the traveling frame, and the power supply bar is long in the Y-axis direction. The robot main body is provided with a current-carrying joint that connects the power-supply path on the robot body side to the power-supply bar, the contact member facing the power-supply bar, and the cylinder that contacts and separates the contact member from the power-supply bar. In addition, the pressure contact direction of the contact member with respect to the power feeding bar is set to the rotation mode about the Y axis that acts on the robot body by the weight of the lifting arm. Stud welding apparatus rotation moment of the cement and the reverse direction, characterized in that the set in a direction such that acting on the robot body by a pressure contact force of the contact member.