JP2533667B2 - Welding equipment for automobile bodies - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding apparatus for positioning a predetermined body part and then performing welding by a welding robot when assembling a car body.

2. Description of the Related Art As a positioning device used in the welding and assembling process of a car body of an automobile, there is one disclosed in, for example, Japanese Patent Laid-Open No. 63-178960.

In this device, a plurality of non-autonomous motion type slide units having freedom of motion in three orthogonal directions are installed on a base, and each slide unit is provided with a three-dimensional positioning function and a clamping function for body parts. A switching robot that is equipped with the gauge clamp mechanism that it has, and that changes the three-dimensional position of each gauge clamp mechanism according to the vehicle type, holds a part of each slide unit and operates the slide unit in each direction of freedom of movement. It is provided.

Then, instead of each slide unit not having the function of operating autonomously, the switching robot sequentially and forcibly actuates each slide unit based on predetermined position information, thereby providing a three-dimensional gauge clamp function. The positions are switched, which makes it possible to cope with the positioning of vehicle body parts of a plurality of vehicle types.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the conventional positioning device as described above, not only the automatic welding device that controls actual welding or the switching robot is necessary because the switching robot is required in addition to the welding robot. The entire facility becomes large-scale, which is disadvantageous in terms of space.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a welding robot with the function of a conventional switching robot and use the welding pause time to locate and clamp the welding robot. The purpose of the present invention is to provide a structure in which the equipment cost is reduced and the entire equipment is downsized by switching the position of the mechanism.

Means for Solving the Problems A welding device of the present invention is a non-autonomous vehicle equipped with a base and a brake means installed on the base and having three degrees of freedom of movement in the directions of three orthogonal axes, and independent braking means for each degree of freedom of movement. A plurality of motion type slide units, a locate / clamp mechanism mounted on each slide unit and having a function of positioning the vehicle body parts in three dimensions and a function of clamping the vehicle body parts, a welding gun, and a tip of the robot arm. With the attached engaging means, the engaging means is engaged with a part of the locate / clamp mechanism when the welding gun is at rest to operate the slide unit in each direction of freedom of movement, depending on the vehicle type. A welding robot that changes the three-dimensional position of the locate and clamp mechanism is provided.

Although the degree of freedom of the non-autonomous operation type slide unit is usually restricted by the braking means, the braking means is released and can move freely when the three-dimensional position of the locate / clamp mechanism is changed. It is a thing.

According to the above structure, in addition to the position information for welding, position information for moving each locate / clamp mechanism according to the vehicle type is stored in advance in the control system of the welding robot, and each type is changed by switching the vehicle type. When it is necessary to change the position of the locate / clamp mechanism, that is, to switch the position of each locate / clamp mechanism, the above-mentioned position information of the locate / clamp mechanism is called by using the welding pause time.

Then, after engaging the engaging means of the welding robot with a part of the locate / clamp mechanism, the brake means is released,
The three-dimensional position of the locate / clamp mechanism is switched by forcibly operating each slide unit based on predetermined position information.

Embodiment FIG. 1 to FIG. 3 are configuration explanatory views showing an embodiment of the present invention, in which B is a vehicle body before an opening / closing body such as a door is attached, 1 is a horizontal reciprocating movement and is a step A transfer bar for transporting the vehicle body B one by one, a welding robot 2 and a positioning device 3. The vehicle body B conveyed from the previous process by the transfer bar 1 is transferred to the positioning device 3 and positioned by the actuator driving fingers 4 on the transfer bar 1 being lowered by a predetermined amount as is well known.

A spot welding gun 7 is attached to the tip of a robot arm 5 of the welding robot 2 via a bracket 6 as shown in FIG. 1, and a locate pin 8 is fixed to the bracket 6 as an engaging means.

The positioning device 3 is a non-autonomous operation type slide unit having a base 9 installed on a floor F as shown in FIG. 10 and a locate / clamp mechanism 11 mounted on each slide unit 10.

As shown in FIG. 4, the slide unit 10 includes a slide table 13 guided by a guide rail 12 and slidable in the Y direction, and a slider 15 guided by the guide rail 14 and slidable in the Z direction with respect to the slide table 13. And a slide table 17 which is guided by a guide rail 16 on the upper surface of the slider 15 and is slidable in the X direction. The guide shaft 19 is inserted in the main body 18 of the slide tables 13, 17 and the slider 15. Brake units 20 as the braking means are provided separately.

Therefore, the slide tables 13 and 17 and the slider 1
5 is locked at a predetermined position unless the brake unit 20 is released. Reference numeral 40 is an assist cylinder that always applies an upward assisting force to the slider 15.

The brake unit 20 has a main body 18 as shown in FIG.
The braking force is obtained by the compression coil spring 21 built in the main body portion 18 by pressing the brake shoe 24 against the guide shaft 19 via the brake piston 22 and the steel ball 23 by the compression coil spring 21. The relative movement between the guide shaft 19 and the guide shaft 19 is prevented, and conversely, air is introduced from the port 25 and the brake piston 22 is pushed back against the force of the compression coil spring 21 to release the above braking force. .

As shown in FIGS. 6 and 7, the locate / clamp mechanism 11 has a post portion 26 fixed to the slide table 17.
And a clamp cylinder 27 supported by the post portion 26 as a center, and a locating pin 29 having a slot 28 formed at the center is fixed to the tip end surface of the post portion 26.

A hook-shaped clamp lever 30 is inserted into the slot 28 of the locate pin 29, and the clamp lever 30 is attached to the tip of the piston rod 31 of the clamp cylinder 27 by the pin 32.
Are connected via Further, a guide pin 33 is integrally provided on the clamp lever 30 separately from the pin 32,
These pins 32 and guide pins 33 are engaged with cam grooves 34 formed on both side surfaces of the post portion 26. Therefore, the clamp lever 30 can be moved between the clamp position P ₁ and the unclamp position P _{2 in} FIG. 6 by the action of the clamp cylinder 27.

That is, according to the locate and clamp mechanism 11 described above,
Locate the locating hole 35 into which the locating pin 29 is inserted beforehand on the vehicle body B.
By forming it on the side floor panel 36, the body B is positioned in the three-dimensional direction, and then the clamp lever 30 is positioned.
Can be clamped by.

As shown in FIG. 1, an arm bar 37 is integrally connected to the post 26 of the locate / clamp mechanism 11 toward the welding robot 2 side, and a cylinder is attached to the tip of the arm bar 37.
A chucking unit 39 that performs chucking and uncucking operations by the 38 is provided. The chucking unit 39 serves to chuck the locate pin 8 on the robot arm 2 side inserted into the chucking unit 39 as described later.

Next, the operation of the welding device configured as described above will be described with reference to the time chart of FIG.

1 to 3, assuming that the vehicle type of the vehicle body B conveyed by the transfer bar 1 is, for example, a vehicle type, the transfer bar 1 is conveyed when the vehicle body B is conveyed right above the positioning device 3. The fingers 4 attached to the lower part move down, whereby the vehicle body B is transferred to each locate / clamp mechanism 11 of the positioning device 3.

Prior to this, since the locate pin 8 is inserted into the chucking unit 39 at the tip of the arm bar 37 in advance and chucked, the time when the vehicle body B is conveyed right above the positioning device 3 as described above. Then, the brake unit 20 (see FIG. 4) of each slide unit 10 is released. As a result, each slide unit 10 is in a state where it can freely move in the three-dimensional direction when an external force is applied.

Further, since the position information of the three-dimensional position of the locate / clamp mechanism 11 necessary for positioning the vehicle body B of each vehicle type is stored in the control system of the welding robot 2 in advance, the vehicle type information of the a vehicle type described above is stored. The position information of the locate / clamp mechanism 11 necessary for receiving and positioning the vehicle body B of the vehicle type a is called, and the welding robot 2 operates based on this position information.

That is, since the locate pin 8 at the arm tip of the welding robot 2 is chucked by the chucking unit 39 in advance as described above, the robot arm 5 of the welding robot 2 can move three-dimensionally to the designated position. As a result, the slide tables 13 and 17 and the slider 15 of each slide unit 10 shown in FIG. 4 slide, and finally the locate pin 29 (see FIG. 6), which is the center of the locate / clamp mechanism 11, is of the a model type. The vehicle body B is positioned at a predetermined position necessary for positioning.

When the locate pin 29 of each locate / clamp mechanism 11 is positioned at a predetermined position, each brake unit 20 of the slide unit 10 is brought into a braking state all at once, and each degree of freedom of operation of the slide unit 10 is restricted and locked again. . At the same time, the chucking unit 39 performs the unchucking operation, and the welding robot 2 chucks the chucking unit.
While the locate pin 8 is pulled out from 39, the fingers 4 shown in FIG. 1 are lowered to transfer and position the vehicle body B of vehicle type a to the locate / clamp mechanism 11.
Then, the clamp lever 30 shown in FIG. 6 further performs a clamping operation, so that the vehicle body B previously positioned by the locate pin 29 is firmly clamped.

When the vehicle body B is thus positioned by the positioning device 3, the transfer bar 1 is retracted, while the welding robot 2 starts the welding operation and the spot welding gun 7 is moved.
As a result, predetermined spot welding is applied to the vehicle body B.

When the spot welding by the welding robot 2 is completed, the welding robot 2 chucks the locate pin 8 into the chucking unit.
39, and the chucking unit 39 is the locating pin 8
To chuck. Simultaneously locate and clamp mechanism 11
The clamp lever 30 of the unclamp operation and the brake unit 20 of each slide unit 10 are released,
Under this condition, the welding robot 2 operates to return each slide unit 10 to the predetermined origin position. Then, one cycle ends with the above, and thereafter, the same operation as described above is repeated.

Here, in the above-described embodiment, the case where the invention is applied to the body main assembly process of the automobile has been described, but the present invention can be similarly applied to, for example, a floor main assembly process other than the body main.

EFFECTS OF THE INVENTION As described above, according to the present invention, the welding robot itself serves to switch the three-dimensional position of the locate / clamp mechanism by utilizing the down time of the welding robot. This eliminates the need for the switching robot, and as a result, it can contribute to the improvement of space efficiency as well as the significant reduction of equipment cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an embodiment of the present invention and is an explanatory view of the right side of FIG. 2, FIG. 2 is an explanatory view of the configuration of the entire apparatus, and FIG. FIG. 4 is an explanatory plan view, FIG. 4 is an enlarged perspective view of an essential part showing details of a slide unit, FIG. 5 is a sectional view of a brake unit, FIG. 6 is a sectional view of a locate / clamp mechanism, and FIG.
6 is a plan view of FIG. 6 and FIG. 8 is a time chart for explaining the operation of the entire apparatus. B: car body, 2 ... welding robot, 3 ... positioning device, 5 ... robot arm, 7 ... spot welding gun,
8: locate pin as engaging means, 9: base,
10 …… Slide unit, 11 …… Locate / clamp mechanism, 20 …… Brake unit as braking means, 29
...... Locate pin, 30 ...... Clamp lever, 39 ...... Chucking unit.

Claims (1)

(57) [Claims] 1. A welding device for an automobile body in which a plurality of vehicle body parts are positioned / clamped by a locate / clamp mechanism and then welded by a welding robot. A base and an orthogonal 3 installed on the base. A plurality of non-autonomous slide units having axial freedom of movement and independent braking means for each freedom of movement, and a three-dimensional positioning function of vehicle body parts mounted on each slide unit And a locate / clamp mechanism having a function of clamping the vehicle body part, and an engaging means attached to the tip of the robot arm together with the welding gun. By engaging the slide unit in each direction of freedom of movement by engaging with a part of A welding device for an automobile body, which comprises a welding robot that changes the three-dimensional position of the drive mechanism.