JPS6149029B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is mainly used for welding automobile exhaust pipes, and includes a work jig having a support and a base on a turntable.
The present invention relates to an improvement in a full-circumference automatic welding machine that welds a predetermined portion of the workpiece, which is erected on the base and supported by supports, and which rotates as the turntable rotates, all around the circumference.

In the case of the above-mentioned all-around automatic welding machine, the support of the workpiece jig, which moves as the turntable rotates, hits the stationary torch, making it impossible to weld all around. It is said that the structure is such that it never happens. Representative examples include:
As shown in Fig. 1, a turntable c is installed on the base b of a U-shaped installation body a, and a base e of a work jig d is placed on this turntable c.
and a lower support post f are arranged, and an upper support support i is arranged to hang down from a turn table h installed on an arm g of installation body a, and moves as the turn tables c and h rotate. A split pillar structure in which the torch j does not hit the lower pillar f and the upper pillar i (the example shown is vertical, but this type also has a horizontal shape). Alternatively, as shown in FIG. 2, a turntable l and a rotary torch stand m are installed on an installation base k, a work jig p consisting of a base n and a support o is installed on the turntable l, A torch q is installed on a rotating torch stand m. As shown in Fig. 3, the welding process begins with the rotation of the rotary torch m until the workpiece s is displaced about 1/4 of the way, that is, 90°, from the outer peripheral point A of the workpiece s, which is located on the center line r connecting with the support column o. After welding, the rotary torch base m reaches the point where it has been displaced by 90 degrees, that is, the point B, and stops, and at the same time, the turntable l rotates in the direction of the arrow while spewing out welding flame, and the remaining 3/3 Four
Weld the circumference, that is, 270°, and at this time,
Torch q should stop at point A as shown in Figure 4, and avoid supporting column o even if it is fixedly installed.
There is a pillar type (torch rotating type) that has a structure that allows 360° full circumference welding.

However, while all of the above conventional methods can achieve the desired 360° circumferential welding, they also have the disadvantage of being complicated and large in size.
Due to the structure of the strut, it cannot be applied to workpieces with different shapes, and a dedicated machine is required for exhaust pipes that have different shapes for each car model. Therefore, not only does this cause an increase in costs, but the actual situation is that a considerably large area of space is required for welding.

On the other hand, the workpiece, which is the object to be welded, has dimensional errors during processing and assembly errors resulting from this. Therefore, in this type of all-around automatic welding machine, the torch must be set so as to follow these errors and always eject welding flame to a predetermined welding area. Therefore, conventionally, a workpiece copying mechanism is provided which follows the error in the workpiece and automatically sets the torch to a predetermined welding part. However, since conventional workpiece copying mechanisms have an electrical detection structure, even if they can achieve the intended purpose, the structure is complex, the failure rate is high, and maintenance is poor. On top of that, it was expensive.

As mentioned above, in this type of all-around automatic welding machine, problems caused by the support that constitutes the workpiece jig, as well as errors in processing and assembly of the workpiece to be welded, are dealt with. There are two major problems with the copying mechanism.
These solutions were desired.

Therefore, the present invention provides a full-circumference automatic welding machine that can solve each of the above problems at the same time.

Hereinafter, an embodiment of the present invention will be described based on FIG.

In the figure, 1 has a turntable 2 connected to its upper part, and it rotates 1.06 times in both forward and reverse directions (approximately
380°) A positioner 3 that displaces and stops is fixedly set on the turntable 2 via a pedestal 4, and is a work jig consisting of a base 5 and a support 6 erected on the base 5. It is.

According to this workpiece jig 3, a workpiece 7 (the illustrated example is an automobile exhaust pipe) is erected on the base 5, supported by the workpiece holding piece 8 of the support 6, and at the same time, the workpiece 7 is mounted on the base 5. It is held by a clamp 9 which is provided. Then, as the positioner 1 is driven, the turntable 2 is displaced by 1.06 rotations in the forward or reverse direction and then stopped. At this time, the workpiece held in the workpiece jig 3 on the turntable 2 Welding part A is also displaced by 1.06 turns together with turntable 2.

The support 6 of the work jig 3 includes an upper support 60,
It is composed of an intermediate strut 61 and a lower strut 62, and as shown in FIGS. 6 and 7, the intermediate strut 61 is connected to the upper strut 60 and the lower strut erected on the same axis. It consists of two U-shaped constituent columns 61a and 61b which are positioned to sandwich the column 62 and are rotatable in the radial direction relative to the upper column 60 and the lower column 62.

Connection bolts 10 and 11 are vertically fixed to the upper arm 61c and lower arm 61d of both constituent columns 61a and 61b, and the upper arm 6
A thrust bearing 12 with a protruding race end is fitted onto the upper or lower surface of the lower arm 61d and the lower arm 61d. The lower arm 61d is
Connected and fixed to the installation plate 62a of the lower support 62 fixedly installed on the base 5 with the connecting bolt 11,
Moreover, a connection plate 13 for both constituent columns 61a and 61b is installed on the upper arm 61c, and is fitted to both the connection bolts 10, and is removably connected to the connection plate 13 by the connection bolt 10. Upper support column 6
0 is fixed upright. Therefore, with the upper strut 60 and the lower strut 62 located on the same axis, each constituent strut 61a, 61b of the intermediate strut 61
As mentioned above, the upper strut 60 and the lower strut 6
2, it is rotatable in the radial direction as shown in the imaginary diagram. Therefore, even if it comes into contact with a stationary torch, etc. (described later) while moving as the turntable 2 rotates, the contact force will cause the turntable 2 to rotate in the opposite direction. It rotates and does not interfere with torches, etc., and enables automatic welding all around 360 degrees.

Note that the reason why the constituent columns of the intermediate column 61 are composed of the two constituent columns 61a and 61b is that if there is one constituent column, the upper column 60, which is in a free state as the constituent column rotates, will be together. This is because the support function for the workpiece 7 cannot be obtained. Further, the reason why the constituent columns 61a and 61b are formed into a U-shape is to enable rotation with a slight force and at the same time to move the column portions to a position where they do not interfere with the torch or the like.

14 is a torch mount horizontally installed on a hydraulic lifting column 16 having a lifting rod 15;
On this torch mount 14, a workpiece copying mechanism 19 consisting of an eccentric copying mechanism 17 and a height copying mechanism 18 is provided.
A torch 20 is installed.

The eccentric copying mechanism 17 includes the torch mount 14
is slidably fitted to brackets 21, 21 which are arranged and fixed at a predetermined interval, and
Two guide shafts 2 arranged at a predetermined interval
2, 22 installed horizontally moving table 23
The horizontal moving table 23 is fixedly installed in the front part, and at the tip thereof, as shown in FIG.
4 and 24, and a U-shaped bracket 27 which is fixedly installed in a horizontal state at the center of the rear of the horizontal moving table 23 and has the tip of the piston 26 fixed to the horizontal moving table 23. The air cylinder 28 is pivotally connected to the air cylinder 28. Therefore, when the air cylinder 28 is extended,
The contact 25 moves horizontally forward together with the horizontal moving table 23, and conversely, when the air cylinder 28 is contracted, the contact 25 moves horizontally backward together with the horizontal moving table 23. By this action, when the workpiece 7 is set, both rotating rollers 24, 24 of the contactor 25 are brought into contact with the outer peripheral surface B of the workpiece 7. At this time, the air cylinder 28 moves the contact 25 to its both rotating rollers 2.
4 and 24 are brought into contact with the outer circumferential surface B of the workpiece 7 with a pressure that allows them to rotate, and at the same time, the contactor 25 is expanded and contracted so as to be able to move within a predetermined stroke range in the front and back direction.

Further, the height copying mechanism 18 includes a seesaw type installation body 29 fixedly installed on the horizontal moving table 23 of the eccentric copying mechanism 17, and this seesaw type installation body 2.
It is fixed to the front end of the upper arm 30 of 9,
In addition, a rod-shaped contactor 32 that brings the tip horizontal bent portion 31 into contact with the horizontal end surface of the workpiece 7 (in the case of the illustrated example, the shell-wrapped portion of the muffler) c, and a vertical position on the rear end of the lower arm 33 and an air cylinder 36 which is installed at the horizontal movable table 23 and whose tip end is pivotally connected to a U-shaped bracket 35 fixed to the rear end of the horizontal moving table 23. Therefore, when the air cylinder 36 is extended, the lower arm 33 rises using the pivot shaft 37 as a fulcrum, and the upper arm 30 descends together with the seesaw-type installation body 29, and the contactor 32 descends, conversely causing the air cylinder 36 to move upward. When contracted, the lower arm 33 descends about the pivot shaft 37, and the upper arm 30 rises together with the seesaw type installation body 29 and the contactor 32.
will rise. Due to this action, when the workpiece 7 is set, the horizontal bent portion 31 of the tip end of the contactor 32 is brought into contact with the horizontal end surface C of the workpiece 7. At this time, the air cylinder 36
1 is brought into contact with the horizontal end surface C of the workpiece 7 with a predetermined pressure, and at the same time, the contactor 32 is expanded and contracted so that it can be moved vertically within a predetermined stroke range.

A torch 20 is fixedly installed on the contactor 32 of this height copying mechanism 18 via a bracket 38. Incidentally, an adjustment bolt 39 is provided on the horizontal moving table 23 to hold the lower arm 32 of the seesaw-type installation body 29 in a horizontal state.
Further, in the figure, 40 is a control panel that automatically controls the positioner 1, the torch 20, etc.

In the all-around automatic welding machine of the above embodiment, the workpiece 7 is set on the workpiece jig 3 as described above, and the contactor 25 of the eccentric copying mechanism 17 in the workpiece copying mechanism 19 and the height copying mechanism 18
After setting the contactor 32, the turntable 2 is rotated by the positioner 1 and the welding flame is ejected from the torch 20 at the same time, thereby welding the welding part A of the workpiece 7. . At this time, the support 6, which moves as the turntable 2 rotates, is rotated so that the turntable 2 is 3/3
When the torch rotates nearly four times, the intermediate support 61 comes into contact with the stationary torch 20. However, in this case, each component support 61 of the intermediate support 61
a and 61b rotate in the radial direction relative to the upper support 60 and lower support 62 as described above,
The contact force of the torch 20 and the contacts 25 and 32 causes it to rotate following the rotation of the turntable 2. Therefore, 360° full circumference welding can be achieved without any problem. Positioner 1 connects turntable 2
The workpiece 7 is rotated by 1.06 degrees and stopped at the same time, and then the workpiece 7, which is set on the workpiece jig 3, is welded from the opposite direction by reversing the positioner 1.

On the other hand, both contacts 25 and 32 follow the outer circumferential surface B and horizontal end surface C of the rotating workpiece 7, thereby causing the torch 20 to move in conjunction with the workpiece copying mechanism 19.
The welding flame can always be ejected to the welding part A even if there is an error in processing or assembling the workpiece 7. Next, when setting the same type of work 7,
This is done with both contacts 25 and 32 set.

Here, the specific structure of each air cylinder 28, 36 and its piping structure can be implemented using known technology that can provide the above-mentioned effect, and it has a special structure. For the sake of clarity, illustrations and explanations are omitted. In addition, illustrations and explanations of the wiring and piping of the positioner 1, hydraulic lifting column 16, torch 20, etc. will be omitted for the same reason.

In summary, in the all-around automatic welding machine according to the present invention, the support of the work jig is composed of an upper support, an intermediate support, and a lower support, and the intermediate supports are erected on the same axis. It consists of two crank-shaped constituent struts located between the upper strut and the lower strut, each of these constituent struts being connected to the upper strut and the lower strut so as to rotate in the radial direction, and an eccentric copying mechanism comprising a contactor that contacts the outer circumferential surface of the workpiece near the welding part, and a cylinder that expands and contracts within a predetermined stroke range while applying a predetermined pressure to the contactor; and the eccentric copying mechanism. The height tracing mechanism is connected to a height tracing mechanism that includes a contact that contacts the horizontal end surface near the welding part of the workpiece, and a cylinder that extends and contracts within a predetermined stroke range while applying a predetermined pressure to this contact. Since the workpiece copying mechanism is equipped with a torch and a torch is installed in the contact portion of the height copying mechanism, as described in the embodiment, the workpiece copying mechanism is Even if the torch (and the contactor of the workpiece copying mechanism), which is in a stationary state, comes into contact with the intermediate column, the constituent columns of the intermediate column will rotate following the rotation of the turn table due to the contact force. Therefore, 360° automatic welding can be performed all around without causing any trouble to the torch (and the contacts of the workpiece copying mechanism). Furthermore, even if there are errors in machining or assembly of the workpiece, the eccentric tracing mechanism and height tracing mechanism do not follow the errors, so that the torch always automatically sprays the welding flame accurately at the welding part. This allows for highly accurate welding.
Moreover, the means to enable automatic welding all around 360° merely improves only a portion of the support;
Because the structure is simple, it does not become complicated and large like conventional ones, and the workpiece copying mechanism has a simple mechanical structure, so the failure rate is low and maintenance is easy. Not only is it possible to provide it at a low cost, but in addition,
Due to the structure of the support, it is possible to install the upper support in a removable manner, making it possible to adapt to various workpiece shapes by simply replacing the upper support with one that matches the workpiece, making it possible to replace the conventional dedicated machine. It is versatile and can solve the problems of this type of all-around automatic welding machine at the same time.

Note that the workpiece to which the automatic welding machine of the present invention can be applied is not limited to an automobile exhaust pipe, but can be any workpiece that has a similar shape and is welded around the entire circumference or on the circumferential surface. It can be widely applied. Furthermore, the structure is not limited to the illustrated structure; for example, the structure of the support, eccentric copying mechanism, height copying mechanism, etc. can be modified in various ways without departing from the technical idea set forth in the claims. .

[Brief explanation of the drawing]

1 and 2 are side views showing a conventional all-around automatic welding machine, respectively, FIGS. 3 and 4 are plan views illustrating the welding process in the structure shown in FIG. 2, respectively, and FIG. The figure is a side view of an embodiment of the invention.
Figure 6 is an enlarged longitudinal sectional side view showing the intermediate support portion;
FIG. 7 is an enlarged cross-sectional plan view showing the intermediate support portion;
FIG. 8 is an enlarged plan view of the main part of the contactor of the eccentric copying mechanism. 2... Turn table, 3... Work jig,
5... Base, 6... Strut, 60... Upper Strut,
61... Intermediate support, 61a, 61b... Constituent support, 62... Lower support, 7... Work, 10,1
1... Connection bolt, 12... Thrust bearing, 17... Eccentric copying mechanism, 18... Height copying mechanism, 19... Workpiece copying mechanism, 20... Torch,
25, 32...Contactor, 28, 36...Air cylinder, A...Welding part, B...Outer peripheral surface, C...Horizontal end surface.

Claims (1)

[Claims] 1 A work jig having a support and a base is provided on the turn table, and the work is erected on the base, supported by the support, and the turn table is mounted on the turn table.
In a full-circumference automatic welding machine that welds a predetermined portion of a workpiece that rotates as a table rotates, the support of the work jig is constituted by an upper support, an intermediate support, and a lower support; The intermediate strut consists of two crank-shaped constituent struts sandwiching the upper strut and lower strut that are erected on the same axis, and each of these constituent struts is radially oriented with respect to the upper strut and the lower strut. A contact element that is connected to rotate in a direction and that contacts the outer circumferential surface of the workpiece near the welding part, and a cylinder that expands and contracts within a predetermined stroke range while applying a predetermined pressure to this contactor. Equipped with an eccentric copying mechanism,
Further, the contactor is connected to the eccentric copying mechanism and contacts a horizontal end surface near the welding part of the workpiece, and a cylinder that expands and contracts within a predetermined stroke range while applying a predetermined pressure to the contactor. 1. A full-circumference automatic welding machine comprising: a workpiece copying mechanism comprising a height copying mechanism; and a torch is installed in a contact portion of said height copying mechanism.