JP2000158135A - Automatic welding system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out a work positioning accurately at a time of welding and, to restrain a facility from getting into a complicated one even when the kinds of machines are changed. SOLUTION: This system comprises a transfer route 5 being installed between a work charging station 2 and a work discharge station 3 for running a transfer robot 6 freely on one hand, and a plurality of welding stations 4 with which a positioner 8 and a pair of multi joints welding robots 7 are arranged respectively. A chassis frame transferred by the transfer robot 6 from the work charging station 2 is delivered to the positioner 8 and, positioned by the positioner 8 for welding with the multi joints welding robot 7. After then, the chassis is delivered again to the transfer robot 6 so as to be transferred to the work discharge station 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an automatic welding system for welding a body frame on an assembly line of, for example, a motorcycle.

[0002]

2. Description of the Related Art Conventionally, a system as shown in FIG. 11 has been used as a welding system for welding a body frame in an assembly line of, for example, a motorcycle. In this system, a plurality of welding stations 51 (three in the figure) are provided, and each welding station 51 is provided.
, A pair of articulated welding robots 52 are provided, and a work transport path 55 for pallet travel is provided between the work input station 53, the work discharge station 54, and each of the welding stations 51. A body frame W as a work is placed on a pallet 56 to be worked as shown in FIG. 12, and the pallet 56 is put into each welding station 51 and welded.

[0003]

However, in the conventional method, a large number of pallets 56 for welding must be prepared, and the body frame W is welded while mounted on the pallets 56. Is difficult because of the combination of the pallet 56 and the articulated robot 52, and there is a problem that the maintenance for maintaining the accuracy becomes complicated, for example, adjustment is required every two to three months. In addition, it is necessary to prepare a dedicated pallet 56 for each model of the body frame W, and there is a problem that as the number of models increases, the types of pallets 56 increase, which increases complexity and equipment cost.

Accordingly, an object of the present invention is to provide an automatic welding system that accurately positions a workpiece during welding and that does not become a complicated facility even if the type of workpiece is changed.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for simultaneously welding a plurality of welding stations simultaneously with respect to a workpiece sequentially input from a workpiece input station, and transferring the welded workpiece to the workpiece. In an automatic welding system for dispensing from a dispensing station, a positioner that holds a workpiece and positions it in a desired posture and a multi-joint welding robot that performs welding on the workpiece held by the positioner are arranged in each welding station. In addition, a transfer robot for transferring the work and transferring and receiving the work to and from the positioners of the respective welding stations is arranged between the work input station and the work discharge station.

[0006] The work input from the work input station is held by a transfer robot and transferred to a desired welding station, transferred to a positioner waiting at the welding station, positioned and welded by the positioner. When the welding is completed, the transfer robot receives the work from the positioner and transfers the work to the work delivery station.

[0007] By thus arranging a dedicated positioner at each welding station and welding to the work positioned by the positioner, the combination of the positioner and the multi-joint welding robot becomes constant, and the positional accuracy during welding becomes stable. Thus, the welding quality can be improved.

According to a second aspect of the present invention, the transfer robot includes:
A head pipe clamp mechanism for clamping the inside of a head pipe of a body frame of a motorcycle or the like by a chuck claw expanding / contracting operation, and a frame pipe clamp mechanism for clamping a frame pipe by an opening / closing operation of a chuck arm are provided.

That is, when the work is a body frame of a motorcycle or the like, the work can be clamped from above the body frame by clamping the inside of the head pipe and the frame pipe. Work can be smoothly exchanged with the holding positioner. Further, by clamping the inside of the head pipe, there is no problem that the external surface such as the outer surface of the head pipe is damaged, and the same mechanism can be used for all models, which is convenient.

[0010] Further, the position of the chuck arm of the frame pipe clamp mechanism can be changed. If the position of the chuck arm can be changed in this manner, for example, even if the model of the vehicle body frame is changed, it is possible to always clamp an appropriate portion, thereby increasing versatility.

[0011]

Embodiments of the present invention will be described with reference to the accompanying drawings. Here, FIG. 1 is a layout view of the automatic welding system according to the present invention, FIG. 2 is a plan view of the welding station, FIG. 3 is a front view of the welding station, FIG. 4 is a front view of the positioner, and FIG. 6 is a cross-sectional view of FIG. 5 as viewed from the side, FIG. 7 is a cross-sectional view taken along the line AA of FIG. 6, and FIG.
9 is an enlarged view of the head pipe clamp mechanism, and FIG. 10 is a bottom view of FIG.

The automatic welding system 1 according to the present invention is applied to a welding system for welding a body frame of an assembly line of a motorcycle or the like, for example, and as shown in FIG. Station 2
And three types of welding stations 4 are provided between the work dispensing stations 3 for discharging the body frame W after welding, and the body frames W sequentially input from the work input station 2 are mutually connected at the respective welding stations 4. A similar welding operation can be performed independently.

An elevated transport path 5 as shown in FIG. 3 is provided between the work input station 2 and the work discharge station 3, and a pair of transport robots 6 travel along the transport path 5. A part of the welding station 4 faces below the transport path 5 while being free.

That is, as shown in FIG. 2, the welding station 4 includes a work transfer section 4w facing the lower part of the transport path 5,
A work welding portion 4s on the side of the transport path 5 is provided, and two articulated welding robots 7 are arranged in the work welding portion 4s so as to face each other, and between the work transfer portion 4w and the work welding portion 4s. , A positioner 8 is movably provided.

When the vehicle body frame W is loaded from the work loading station 2 shown in FIG. 1, the transport robot 6 on one side grips it and transports it to a desired welding station 4, where the positioner stands by below. 8, the positioner 8 moves to the work welding portion 4s, converts the posture of the body frame W into a desired posture, and positions the body frame W.
Welding is performed by the articulated welding robot 7. When the welding is completed, the positioner 8 moves toward the work transfer section 4w, transfers the work to the transfer robot 7 on the other side, and transfers the work to the work delivery station 3.

As shown in FIG. 4, the positioner 8 includes a swing frame 12 pivotally supported by a support member 11 of the traveling platform 10, and a guide member 13 attached to the lower surface of the traveling platform 10 is illustrated. 3 is slidably engaged with the rail 14 shown in FIG. The body frame W is clamped with the lower surface of the head pipe at the front of the vehicle body and the lower surface of the frame at the rear of the vehicle body supported and clamped by the clamp member 15 erected on the swing frame 12, and by swinging the swing frame 12. The vehicle body frame W can be positioned at an arbitrary angle using the longitudinal direction of the body frame W as a rotation axis.

As shown in FIG. 3, the transfer robot 6 includes a traveling platform 16 disposed above the transporting path 5 and a clamp unit 17 mounted below the traveling platform 16 so as to be movable up and down. A traveling drive motor 18, a lifting drive motor 20, and a slide bush 21 are attached to an upper portion of the table 16.

A pinion gear 22 is attached to the output shaft of the traveling drive motor 18, and this pinion gear 22
Meshes with a rack 23 fixed along the transport path 5, and when the traveling drive motor 20 is operated, the traveling platform 16 travels along the transport path 5.

A pinion gear 24 is attached to the output shaft of the lifting drive motor 20.
Are engaged with a rack 25 fixed vertically to the clamp unit 17, and when the lifting drive motor 20 is operated, the clamp unit 17 is moved up and down. At this time, the guide shaft 26 attached to the clamp unit 17 slidably penetrates the slide bush 21 to guide the ascending and descending.

As shown in FIG. 5, the clamp unit 17 has a head pipe clamp mechanism 31 attached below one end of the clamp table 27 and a frame pipe clamp mechanism 32 attached below the other end. The head pipe clamp mechanism 31 has a chuck claw 33 for clamping the inside of the head pipe in front of the vehicle body frame W, and the frame pipe clamp mechanism 32 has a mechanism for clamping the frame pipe behind the vehicle body.

That is, the frame pipe clamp mechanism 3
As shown in FIGS. 6 to 8, the movable frame 2 includes a movable frame 35 whose position can be changed with respect to the fixed base 34. Inside the movable frame 35, a pair of chuck arms 36 can be freely opened and closed. It is arranged to be able to move up and down freely. In order to move the movable frame 35 with respect to the fixed base 34, as shown in FIG. As shown in FIG. 7, the horizontal ball screw shaft 41 is rotated by the rotation of the position adjustment motor 40 attached to the fixed base 34, and the screw body 42 integrated with the moving frame 35 is screwed onto the ball screw shaft 41. Have been combined.

For this reason, when the ball screw shaft 41 is rotated by the position adjusting motor 40, the moving frame 35 integrated with the screw body 42 moves from the solid line position in FIG. 5 to the chain line position or from the chain line position to the solid line position.

As shown in FIGS. 6 and 7, a pair of vertical ball screw shafts 44 are provided at both ends of the moving frame 35 and rotate by transmitting the operation of the height adjusting motor 43 by a timing pulley 49 or the like. A screw body 45 is screwed to each of the ball screw shafts 44, and a cylinder mount 46 is connected between the two screw bodies 45. And on the upper part of this cylinder mounting base 46,
The base ends of a pair of cylinder units 47 as shown in FIG. 8 are symmetrically attached, and the chuck arm 36 is attached to the tip of a cylinder rod.

When the pair of ball screw shafts 44 is rotated by the height adjusting motor 43,
The cylinder mounting base 46 integral with 5 moves up and down a predetermined stroke, and the chuck arm 36 opens and closes by the operation of the cylinder unit 47.

Incidentally, the position change of the moving frame 35 and the adjustment of the vertical movement of the chuck arm 36 are performed in order to adjust an appropriate portion when a model of the body frame W to be handled is changed. Things.

As shown in FIGS. 9 and 10, the head pipe clamp mechanism 31 has three chuck claws 33 which expand and contract in the radial direction by the operation of the clamp cylinder 48. As shown in FIG. The chuck claw 33 is inserted into the head pipe of the vehicle body frame W and is expanded so that the inner surface of the head pipe can be held.

The automatic welding system 1 configured as described above
The operation and the like of will be described. Work input station 2
When the vehicle body frame W is loaded from above, the transfer robot 6 on one side clamps it. At this time, the inner surface of the head pipe is clamped by the chuck claws 33 of the head pipe clamp mechanism 31, and the rear frame pipe is clamped by the chuck arm 36 of the frame pipe clamp mechanism 32.

Next, when the transfer robot 6 travels along the transport path 5 by the travel drive motor 18 and moves to the desired welding station 4, as shown in FIG. 3, the positioner stands by at the work transfer section 4 w of the welding station 4. The lifting drive motor 20 is operated above the position 8, the clamp unit 17 is lowered, and the vehicle body frame W is placed on the clamp member 15 of the positioner 8 and delivered.

The positioner 8 receives the vehicle body frame W
Is clamped and moved to the welding portion 4s, and then the swinging frame 12 is swung as necessary to change the posture, and welding is performed by the articulated welding robot 7.

When the welding is completed, the positioner 8
Returns to the work transfer section 4w and transfers the vehicle body frame W to the transfer robot 6 on the other side. That is, the transfer robot 6
Is lowered, clamps the vehicle body frame W and pays it out to the work payout station 3.

In the above-described automatic welding operation, when the model of the body frame is changed, the original position of the chuck arm 36 of the frame pipe clamp mechanism 32 is changed by the position adjusting motor 40 and the height adjusting motor 43. Is set at the position appropriate for the model.

In the above welding method, the combination of the positioner 8 and the articulated welding robot 7 at each welding station 4 is always constant, and the error of the welding position is smaller than that of the conventional combination of the pallet and the welding robot. And weld quality is improved.

The present invention is not limited to the above embodiment. Those having substantially the same configuration as those described in the claims of the present invention and exhibiting the same operation and effect belong to the technical scope of the present invention. For example, the number of welding stations can be arbitrarily set, and the present invention can be applied to works other than the body frame W such as a motorcycle.

[0034]

As described above, according to the automatic welding system according to the present invention, in an automatic welding system in which a plurality of welding stations perform a welding operation simultaneously and simultaneously, a work is held at each of the welding stations. A positioner that positions the robot in a position, and a multi-joint welding robot that performs welding on the work are provided. The work is transferred between the work input station and the work discharge station, and the work is transferred to the positioners at each welding station. In addition, since the transfer robot for receiving is arranged, the combination of the positioner and the articulated welding robot becomes constant, the welding position is stabilized, and the welding quality can be improved.

According to a second aspect of the present invention, the transfer robot
If a head pipe clamp mechanism that clamps the inside of the head pipe of a motorcycle or the like by the expansion and contraction operation of the chuck claw and a frame pipe clamp mechanism that clamps the frame pipe by the opening and closing operation of the chuck arm are provided, the work can be performed on the body frame of the motorcycle or the like. In this case, the work can be smoothly exchanged with the positioner, and the inside of the head pipe can be clamped to prevent a defect such as a scratch on the outer surface. Further, if the position of the chuck arm of the frame pipe clamp mechanism can be changed, it is possible to cope with a change in the model of the body frame, for example.

[Brief description of the drawings]

FIG. 1 is a layout diagram of an automatic welding system according to the present invention.

FIG. 2 is a plan view of a welding station.

FIG. 3 is a front view of a welding station.

FIG. 4 is a front view of a positioner.

FIG. 5 is an enlarged view of the clamp unit of the transfer robot as viewed from the front.

FIG. 6 is a cross-sectional view of FIG. 5 viewed from the side.

FIG. 7 is a sectional view taken along line AA of FIG. 6;

FIG. 8 is a sectional view taken along line BB of FIG. 6;

FIG. 9 is an enlarged view of a head pipe clamp mechanism.

FIG. 10 is a bottom view of FIG. 9;

FIG. 11 is an explanatory view of a conventional welding system.

FIG. 12 is an explanatory view of a conventional pallet.

[Description of Signs] 1 ... Automatic welding system, 2 ... Work input station,
Reference numeral 3 denotes a work dispensing station, 4 denotes a welding station, 6 denotes a transfer robot, 7 denotes an articulated welding robot, and 8 denotes a robot.
Positioner, 31 ... Head pipe clamp mechanism, 32
... Frame pipe clamp mechanism, 33 ... Chuck claw, 3
6: chuck arm, W: body frame.

Continued on the front page (72) Inventor Kokichi Tagami 1500 Hirakawa, Otsu-cho, Kikuchi-gun, Kumamoto Honda Motor Co., Ltd.Kumamoto Works Co., Ltd. Inside the Kumamoto Factory (72) Inventor Yuichi Serikawa 1500 Hirakawa, Otsu-cho, Kikuchi-gun, Kumamoto Prefecture Honda Motor Co., Ltd.Kumamoto Factory

Claims (3)

[Claims] An automatic welding system in which a plurality of welding stations simultaneously perform welding work on a work sequentially input from a work input station and discharge the welded work from a work discharge station. In each of the welding stations, a positioner for holding a work and positioning it in a desired posture, and a multi-joint welding robot for welding the work held by the positioner are provided. An automatic welding system, comprising a transfer robot for transferring a work and transferring and receiving the work to and from a positioner of each welding station between the stations. 2. The automatic welding system according to claim 1, wherein the transfer robot includes a head pipe clamping mechanism for clamping an inside of a head pipe of a body frame of a motorcycle or the like by expanding and contracting chuck jaws, and opening and closing a chuck arm. An automatic welding system comprising a frame pipe clamp mechanism for clamping a frame pipe by operation. 3. The automatic welding system according to claim 2, wherein the position of the chuck arm of the frame pipe clamp mechanism is changeable.