JPH0421663Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a symmetrical positioning device for spot welding robots and the like for automobile bodies.

[Conventional technology]

For example, in a spot welding robot for automobile bodies, as shown in the system diagram in Figure 5, there are one axis for traveling and five axes for work on the left and right sides of the cross beam of a gate-shaped jig that straddles the automobile body (hereinafter referred to as the work) Wk. A pair of left and right slide units Sld with total 6-axis control
A ₀ and Sld B ₀ are attached, and each slide unit Sld
_{Both slide units Sld}
It is known that A ₀ and Sld B ₀ are moved symmetrically by the same amount at the same speed.

However, in such a robot, each slide unit requires control of 6 axes, so 2 slide units require control of a total of 12 axes, which increases the cost as the structure becomes more complex. do not have.

[Problem that the invention attempts to solve]

The present invention was proposed in view of these circumstances, and has a simple structure, low cost, and symmetrical structure by controlling a total of 11 axes, including 5 axes for work control and 1 axis for travel axis control per slide unit. The purpose of this invention is to provide a target positioning device.

[Means for solving problems]

To this end, the present invention includes a gate-shaped column having a cross beam that is erected on the floor and installed above the workpiece, and a gate-shaped column having both ends pivoted to the gate-type column and installed in parallel along the cross beam, and a gate-shaped column that is installed in parallel from the center to both ends. A symmetrical slide unit comprising: a threaded rod having opposite threads in the feeding direction; and a pair of left and right slide units that are screwed onto each of the screws of the threaded rod and are slidably supported along the cross beam. The positioning device includes a tool attached to each slide unit for processing the workpiece, and a motor connected to one end of the threaded rod for rotating the threaded rod so as to symmetrically interlock the pair of left and right slide units. , a control unit connected to the motor to control the driving of the motor; and a control panel respectively controlling the pair of left and right slide units.

[Effect]

With this configuration, a symmetrical positioning device with a simple structure and low cost can be obtained by controlling a total of 11 axes, including 5 axes for work control and 1 axis for travel axis control per slide unit.

〔Example〕

An embodiment in which the present invention is applied to a spot welding robot for automobile bodies will be explained with reference to the drawings. FIG. 1 is a control system diagram thereof, FIG. 2 is a perspective view of the welding robot shown in FIG. 1, and FIG. 3 is a welding robot shown in FIG. FIG. 4 is a plan view showing the threaded rod and slide unit shown in the figure, and FIG. 4 is an explanatory diagram showing the geometric relationship between the position and speed of the slide unit shown in FIG.

In the above figure, the same symbols as in Fig. 5 indicate the same members and equipment as in the same figure. First, in Fig. 1, Sld A and Sld B are respectively attached symmetrically to the positioning mechanism C according to the present invention. There is a pair of left and right slide units, and each slide unit is a unit that requires five-axis control as work control.

Rob A and Rob B are slide units respectively.
Robot control panel that controls Sld A and Sld B on 5 axes,
Pm is the axis positioning mechanism, Acu is the axis control unit,
Int is an interlock circuit that connects robot control panels Rob A, Rob B, and axis control unit Acu.

Next, in Figs. 2 to 4, 1 is a threaded rod that is arranged in parallel along the cross beam of the gate-shaped guide column and has a left-hand thread and a right-hand thread carved from the center toward the left and right ends, and 4 is a threaded rod 1. a guide shaft attached to the cross beam in parallel to , 5 a motor for rotating the threaded rod 1;
6 is an encoder that outputs the rotation angle of the threaded rod 1;
7 is a pair of left and right bearings that pivotally support both ends of the threaded rod 1;
8 is a control system consisting of robot control panels Rob A, Rob B, axis control mechanism Acu, etc. Wu A, Wu B are a pair of left and right spot welding units.

In such a structure, the threaded rod 1 has right-handed threads of the same pitch symmetrically from the center to the shaft end;
A pair of left and right slide units with left-hand threads.
Sld A and Sld B are screwed together via nuts that screw into the left-hand threaded part and the right-hand threaded part, respectively, so the fourth
As shown in the figure, set the center point to M and slide unit.
If the positions of Sld A and Sld B are A and B, respectively, then the slide units Sld A and Sld B move simultaneously and symmetrically from A to A' and from B to B' over the same distance with velocity vectors in opposite directions. will be moved to.

Then, in FIG. 2, based on this relationship, the pair of left and right welding units Wu A, Wu B can be moved symmetrically to perform spot welding.

Here, if the spot point is on the center line of the workpiece Wk, offset the center of the workpiece Wk and the center of this device from each other, and move either slide unit Sld A or Sld B to the center of the workpiece Wk. Bring it to the factory and weld it.

At this time, the other welding unit moves out of the spot welding range, but this welding unit does not perform spot welding, so there is no problem.

According to such a device, each slide unit has five working control axes and one axis for controlling the threaded rod, so by controlling a total of 11 axes, it is possible to perform symmetrical spot welding of automobile bodies. ,Traditional
Compared to 12-axis control, the structure is simpler and costs are lower.

Although the above embodiments show the case of spot welding, the mechanism of the present invention can also be applied to continuous processing operations such as arc welding, sealing material filling, and spray painting.

Further, the slide units are not limited to one pair on the left and right, but may be two pairs on the left and right, two on the left and one on the right, or the like.

[Effect of idea]

In short, according to the present invention, a gate-shaped support having a cross beam that is established on the floor and constructed above the workpiece;
a threaded rod having both ends pivotally supported by the portal support, arranged in parallel along the horizontal beam, and having screws in opposing feeding directions engraved from the center toward both ends; A symmetrical positioning device having a pair of left and right slide units screwed together and slidably supported along the cross beam, a tool attached to each slide unit for machining the workpiece, and a tool attached to one end of the threaded rod. a motor that is connected and rotates the threaded rod so as to symmetrically interlock the pair of left and right slide units;
By providing a control unit that is connected to the motor and controls the drive of the motor, and a control panel that controls each of the pair of left and right slide units, a symmetrical positioning device with a simple structure and low cost is obtained. The present invention is extremely useful industrially.

[Brief explanation of the drawing]

Fig. 1 is a control system diagram showing an embodiment in which the present invention is applied to a spot welding robot for automobile bodies, Fig. 2 is a perspective view of the welding robot shown in Fig. 1, and Fig. 3 is a threaded rod and a welding robot shown in Fig. 2. FIG. 4 is a plan view showing the slide unit, and is an explanatory diagram showing the geometric relationship between the position and speed of the slide unit in FIG. 3. Fifth
The figure is a control system diagram showing a known symmetrical spot welding robot for automobile bodies. 1... Threaded rod, 4... Guide shaft, 5... Motor, 6... Encoder, 7... Bearing, 8... Control system, Acu... Axis control unit, C... Positioning mechanism, Int... Inter Lock circuit, M...center,
Pm...Axis positioning mechanism, Rob A...Left robot control panel, Rob B...Right robot control panel, Sld
A...Left side slide unit, Sld B...Right side slide unit, Wk...Vehicle body, Wu A...Left side welding unit, Wu B...Right side welding unit.

Claims (1)

[Scope of utility model registration request] A gate-shaped support having a cross beam that is established on the floor and constructed above the workpiece, and a gate-type support having both ends pivotally supported by the gate-type support and arranged in parallel along the cross beam, and moving from the center toward both ends and opposite in feeding direction. In the symmetrical positioning device, the symmetrical positioning device includes a threaded rod having threads carved therein, and a pair of left and right slide units that are screwed onto each of the threads of the threaded rod and are slidably supported along the cross beam. a tool attached to the slide unit for processing the work; a motor connected to one end of the threaded rod for rotating the threaded rod so as to symmetrically interlock the pair of left and right slide units; A symmetrical positioning device comprising: a control unit that controls driving of the motor; and a control panel that controls each of the pair of left and right slide units.