JPH0242300B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a muffler-like container that reduces exhaust noise emitted from engines of automobiles, two-wheeled vehicles, agricultural machinery, construction machinery, etc., particularly in the axial direction. The present invention relates to a method for welding two tubular members to both sides of a container having varying lengths.

``Prior Art'' Conventionally, when welding a tubular member to both ends of a main cylinder member in an article such as an automobile muffler, welding was performed on one side at a time, so-called double welding. Therefore, as an improvement, the present applicant has provided a method for simultaneously welding two tubular members to a main cylinder member eccentrically and biaxially in JP-A-60-133983. This allows simultaneous welding of tubular members on both sides, allowing the work to be completed with one welding.

``Problems to be Solved by the Invention'' According to the above technical documents, simultaneous welding work is certainly possible, and improvement in work efficiency can be expected. However, as a practical matter, there is slight variation in the axial length of the main cylinder member, so when starting welding work, it is necessary to manually fine-tune one of the welding torches each time. The current situation is that this is one of the points to be improved even in continuous assembly line work, as it is necessary to do so, resulting in poor work efficiency and interruption of continuous production line work.

``Means for Solving the Problems'' In view of the above, the present invention provides a main cylinder member that is supplied to a workpiece pedestal, and provides for a main cylinder member that has variations in its axial length within a certain range. To provide a method for reliably welding two tubular members to a main cylindrical member by making the second welding torch follow this variation even if the shaft When joining two tubular members to predetermined positions on both end faces of a main cylinder member whose lengths vary in direction and welding them in a direction parallel to the axial direction through rotation of the main cylinder member and the tubular member, A first welding torch provided on a frame fixed to a predetermined position facing the outer peripheral surface of one of the two tubular members welds the entire circumference of the tubular member to the main cylinder member, and at the same time welds the length. The main tubular member is directed to a predetermined position on the outer periphery of the other tubular member by a positioning mechanism provided on the frame that can self-adjust its position in accordance with the displacement of a movable positioning block provided on the work holder that receives the main tubular member having variations. The entire circumference of the tubular member and the main cylinder member are welded using two welding torches.

"Operation" Next, the operation of the present invention will be described. The tubular member lifted by the workpiece pedestal and the two tubular members supported by the clamps are assembled. In this case, a movable positioning block welded to the side surface of the main cylinder member is displaced depending on the length of the main cylinder member in the axial direction, and this movable positioning block stops at a predetermined displacement position. Then, the first welding torch fixed at a predetermined position toward the outer peripheral surface of one of the tubular members joined to one side of the main cylinder member approaches the other tubular member joined to the other end face of the main cylinder member. The second welding torch, which is directed at a predetermined position on the outer periphery of the component, approaches this predetermined position as a result of a self-adjustable positioning mechanism being restrained by a movable positioning block that is stopped at said displaced position. Specifically, the first and second welding torches are approached to spot weld the area. Thereafter, as the workpiece pedestal descends, substantially simultaneously the first and second welding torches are energized to start arc welding, and the main cylindrical member and the two tubular members begin to rotate. Along with this rotational movement, the entire circumferences of the two tubular members are simultaneously welded to the main cylinder member, and when this welding is completed, the power supply to the first and second welding torches is stopped, and the rotation of the main cylinder member, etc. Movement is stopped. Next, the workpiece pedestal is raised to grasp and remove the main cylinder member to which the two tubular members are welded, completing one cycle of welding work.

``Example'' Hereinafter, a welding device suitable for carrying out the welding method according to the present invention and its operation will be described based on the drawings.

In the figure, reference numeral 1 denotes a workpiece holder provided on a piston rod 4 of an air cylinder 3 pivotally connected to a frame 2. The workpiece holder 1 includes a positioning block 5 and a movable positioning block 6 facing the positioning block 5. Each is provided,
As shown in the figure, this movable positioning block 6 is operated by the elastic force of the spring 7 and the forward action of the connecting pin 8, so that the upper part of the movable positioning block 6 is moved to the workpiece pedestal 1.
The movable positioning block 6 is tilted inward (in this case, the main cylinder member A is smaller than the standard size), and the upper part of the movable positioning block 6 is tilted toward the outside of the workpiece holder 1 due to the pressure of the spring 7 and the retreating action of the connecting pin 8. (in this case,
The main cylinder member A is larger than the standard size). 9 is a column 10 installed on the frame 2
This support frame 9 has a tip bent portion 9a pivotably attached to the support frame 10a, and this support frame 9 swings about the pivot point 10a as a fulcrum with a torch relief rod 11, and is pivoted to this support frame 9 as described later. The torch support frame and the second welding torch are configured to move along an inclined trajectory (dotted chain line in FIG. 2). A torch support frame 13 having a brake body 16 in the form of an arcuate recess at the rear end is pivotally attached 14 to the upper horizontal portion 9b of the support frame 9. A second welding torch 15 is fixed, and a free bearing 17 is provided which attaches to the movable positioning block 6 via an auxiliary arm 13a. An air cylinder 20 is provided at the upper horizontal portion 9b of the support frame 9. The air cylinder 20 is equipped with a brake shoe 18 which is an arcuate convex portion facing the brake body 16. When the vehicle moves backward, the brake shoe 18 synchronizes with this and presses or releases the press (separates) from the brake body 16. That is, since the brake body 16 and the torch support frame 13 are fixedly held through the pressure of the brake shoe 18 on the brake body 16, the second welding torch 15 is connected to the other one joined to the main cylinder member A. It is stopped at a position on the outer periphery of the tubular member B' pointing toward a predetermined position. Therefore, the second welding torch 15 remains in this position unless the torch relief rod 11 and the air cylinder 20 are activated. Conversely, by releasing the pressure of the brake shoe 18 on the brake body 16, the two are separated and the torch support frame 13 is allowed to freely swing to the left and right in the horizontal direction (hereinafter simply referred to as "swing"). . Furthermore, this support frame 9 is provided with a device that controls the swing range of the torch support frame 13 and its restoration. In this example, the swing range is controlled horizontally from 14 pivot points of the torch support frame 13 Regulation arm 13 extending in the direction
a and a regulating piece 9c equipped with an adjustable pin provided on the supporting frame 9 facing the regulating arm 13a, and there is a distance between the regulating arm 13a and the pin of the regulating piece 9c that extends along the axial length of the main cylinder member A. In addition, the swing range of the torch support frame 13 is restricted by the impact of the restriction arm 13a on the pin. In this example, the device that controls the restoration of the torch support frame 13 is a pin 21 that projects horizontally from the torch support frame 13 and a spring 22 that is wound around the pin 21. The torch support frame 13, which had been swinging to a predetermined position on the left and right sides in response to the length of the main cylinder member A, returns to its original position through the elastic force. The above support frame 9, the torch support frame 13 equipped with the brake body 16, the air cylinder 20 equipped with the brake shoe 18, and the device controlling the regulation and restoration of the swing range constitute a positioning mechanism that can automatically adjust. .

Next, the welding method of the present invention will be explained in detail using the above-mentioned welding device.
The main cylindrical member A lifted by the work holder 1 having a movable positioning block 6 and a movable positioning block 6 is assembled with the two tubular members B and B' supported by clamps (not shown). In this case, the movable positioning block 6 attached to the other end surface of the main tube member A (of course, the positioning block 5 is attached to the other side surface of the main tube member A) is connected to the axial length of the main tube member A. The movable positioning block 6 is displaced depending on the magnitude of the displacement, and the movable positioning block 6 stops at a predetermined displacement position. Specifically, as mentioned above, when the main cylinder member A is smaller than the standard size, the upper part of the movable positioning block 6 moves inward through the elastic force of the spring 7, and conversely, the main cylinder member A is smaller than the standard size. When it is large, the spring 7 is pressed and the upper part of the movable positioning block 6 is positioned outward. Then, the first welding torch 25 fixed at a predetermined position toward the outer peripheral surface of one of the tubular members B joined to one side of the main cylinder member A approaches, and at the same time, the first welding torch 25 is joined to the other side of the main cylinder member A. The operation of the second welding torch 15 to direct the second welding torch 15 toward a predetermined position on the outer periphery of the other tubular member B' occurs when the support frame 9 and the torch support frame 13, which constitute a self-adjustable positioning mechanism, are pushed up by the torch release rod 11. The support frame 9 and the torch support frame 13 are regulated by the movable positioning block 6 and swing in the horizontal direction using the 14 pivot points as fulcrums. , its position is determined by the size of the main cylinder member A, and the second welding torch 15 is thereby stopped at a predetermined position, and as described above, by pressing the brake shoe 18 against the brake body 16, etc., the torch is The second
A welding torch 15 is held fixedly. In this way, the self-adjustable positioning mechanism is regulated by the movable positioning block 6 which is stopped at the displacement position, so that the second welding torch 15 is directed at a predetermined position on the outer periphery of the other tubular member B'. With,
Approach this predetermined position. Specifically, when the first and second welding torches 25 and 15 approach, spot welding is performed on the portion. After this, work pedestal 1
(In this case, the main cylinder member A and the two tubular members B and B' are spot welded and supported via a clamp (not shown)), and the first and second welds are started at approximately the same time. The torches 25, 15 are energized to start arc welding, and the main cylinder members A and 2
The two tubular members B and B' start rotating. Along with this rotational movement, the entire circumferences of the two tubular members B and B' are simultaneously welded to the main cylinder member A, and when this welding is completed, the power supply to the first and second welding torches 25 and 15 is stopped. At the same time, the rotational movement of the main cylinder member A and the like is stopped. Subsequently, the workpiece pedestal 1 rises to grip the main cylinder member A to which the two tubular members B and B' are welded, and the first welding torch 25 moves diagonally through a link mechanism (not shown). At the same time as the second welding torch 15 is moved backward, the support frame 9 and the torch support frame 13 are swung by the rear end of the torch relief rod 11, so that the second welding torch 15 is also moved backward. Next, after releasing the clamp (not shown) and releasing the grip on the two tubular members B and B', the main cylinder member A to which the two tubular members B and B' are welded is removed. The welding work is now complete.

In place of the above-mentioned support frame 9, torch relief rod 11, torch support frame 13, etc., the following devices may be used, although not shown. That is, the support frame is fixed to the frame so as to be arranged diagonally with respect to the workpiece pedestal, and the torch support arm equipped with the brake body is attached to the support frame diagonally through a sliding member fitted with a dovetail groove. The brake shoe provided on the sliding member of the support frame is configured to press or release the pressure from the brake body of the torch support frame, and the brake shoe attached to the torch support frame and the torch support frame is attached to the torch support frame via a link mechanism. The second welding torch is moved forward and backward diagonally and horizontally. As a result, a self-adjustable positioning mechanism that can reliably direct the second welding torch to a predetermined position on the outer periphery of the other tubular member joined to the main cylinder member having variations in length may also be used.

[Effects of the Invention] As described in detail above, the present invention has the first welding torch fixed at a predetermined position facing the outer peripheral surface of one of the tubular members, and the second welding torch movably positioning the workpiece pedestal. The structure is such that the outer periphery of the other tubular member joined to the main cylinder member having variations in length can be directed to a predetermined position via a positioning mechanism that can self-adjust its position in accordance with the displacement of the block;
Since this is a method of simultaneous welding through the rotation of the main cylinder member and the two tubular members, it has the effect of automating the direction of the second welding torch to a predetermined position on the outer periphery.
It is useful for automating and speeding up welding work, and can greatly contribute to significant efficiency improvements and labor savings.
It is highly expected that welding accuracy will be improved and costs will be reduced.

[Brief explanation of drawings]

The drawings show an example of a suitable welding device used in the method of the present invention, with FIG. 1 being a side view, FIG. 2 being a plan view of the same, and FIG. 3 being a front view of the main parts. 1...Hook pedestal, 2...Frame, 3,20
...Air cylinder, 4...Piston rod, 5
...Positioning block, 6...Movable positioning block, 7, 22...Spring, 8...Connection pin, 9...Support frame, 9a...Bending portion, 9b
...Horizontal part, 9c...Regulation piece, 10...Column, 1
0a, 14... Pivot, 11... Torch release rod, 13... Torch support frame, 13a... Auxiliary arm, 15... Second welding torch, 16...
Brake body, 18... Brake shoe, 25...
First welding torch, A... Main cylinder member, B, B'...
...Tubular member.

Claims (1)

[Claims] 1. When joining two tubular members to predetermined positions on both end faces of a main cylindrical member whose lengths in the axial direction vary, and welding them in a direction parallel to the axial direction through rotation of the main cylindrical member and the tubular member. , a first welding torch fixed to a predetermined position facing the outer circumferential surface of one of the two tubular members is used to weld the entire circumference of the tubular member to the main cylinder member, and at the same time, the length variation is eliminated. A second welding torch is directed to a predetermined position on the outer periphery of the other tubular member by means of a positioning mechanism that can self-adjust its position in accordance with the displacement of a movable positioning block provided on a work holder that receives one main tubular member. A method for simultaneously welding two tubular members to a main barrel member having varying axial lengths, the method comprising welding the entire circumference of the tubular member to the main barrel member.