JP2017154141A - Seam welding copying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seam welding copying device which does not give constraint to a work-piece shape with a simple structure and can secure a stable guide function.SOLUTION: A seam welding copying device performs seam welding along a prescribed track with a pair of electrode rollers by supporting work-pieces which have annular portions to be welded on a peripheral part and are superimposed on each other with a work-piece support part, arranging an annular guide rail 24 which has the same with or similar to the portion to be welded integrally with the work-piece support part, arranging a first guide roller 41 on an outer circumferential surface of the guide rail, and a second guide roller 42 on an inner circumferential surface so as to be opposed to each other integrally with an electrode roller and guiding the work-piece while causing the rail to put between both rollers. Therein, two guide rollers are arranged such that a straight line formed by connecting centers of both rollers assumes 40° to 60° with respect to a center line of the annular guide rail and a torque is generated on the guide rail in such a direction that the guide rail is pushed against both guide rollers.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a seam welding copying apparatus capable of smoothly guiding and driving a corner portion with a simple configuration when seam welding is performed on an outer peripheral flange surface such as a silencer.

  When seam-welding the outer peripheral flange surface of a conventional silencer, etc., after temporarily attaching the upper shell and lower shell together and fixing them to the work support part, they are guided by a copying device consisting of a guide rail and a pair of guide rollers. A welding roller is driven to perform welding with a desired trajectory.

In this case, an error tends to occur in the direction of the electrode roller only by arranging a pair of guide rollers on both sides of the guide rail and holding the guide rail by the guide roller. When an error occurs in the direction, a large force is generated in the direction in which the roller deviates from the locus, so that the operation becomes unstable. In order to solve this problem, various structures have been proposed.

For example, in the structure shown in Patent Document 1, as shown in FIG. 7, a total of four guide rollers A, B, C, and D are installed on each side of the guide rail while securing a certain distance. . In this case, since it is guided by two guide rollers per side with a certain interval, a stable work turning can be obtained.
However, due to the arrangement of the two guide rollers C and D on the inner side, the radius of curvature of the R shape of the cam generated at the corner portion inevitably increases, and a corner portion having a small curvature radius cannot be provided on the cam ring. Therefore, restrictions are imposed on the shape of the workpiece.

Further, in the structure shown in Patent Document 2, a pair of guide rollers is arranged on both sides of the guide rail, and two auxiliary rollers are provided to stabilize the operation. However, this method cannot deal with corners that are convex inward and cannot solve the problem of complicated structure.

JP 2002-224842 A Japanese Patent No. 522789

The seam welding copying apparatus invented in the past to secure a stable guide function can not cope with a problem of a complicated structure, a cam with a small curvature radius, a small R, or a corner that protrudes inward. There is a problem that the shape of the workpiece is restricted, such as the locus cannot be set.

  The present invention has been made to solve such problems, and it is an object of the present invention to provide a seam welding copying apparatus that can secure a stable guide function without restricting the workpiece shape with a simple structure. To do.

In the invention according to claim 1, two or more workpieces in an overlapped state having an annular welded portion in the periphery are supported by the workpiece support portion, and an annular shape having the same shape as or similar to the welded portion is provided in the vicinity of the workpiece The guide rail is integrally disposed with the work support portion, the first guide roller is disposed on the outer peripheral surface of the guide rail, and the second guide roller is disposed on the inner peripheral surface so as to be opposed to each other, and is integrally disposed with the electrode roller, In the seam welding copying apparatus, wherein the first guide roller and the second guide roller are guided while sandwiching the annular rail so that seam welding is performed with a pair of electrode rollers on the welding portion, the first guide roller Of the two guide rollers so that a straight line connecting the center of the second guide roller and the center of the second guide roller forms 40 to 60 degrees with the center line of the annular guide rail. And an urging means for urging the guide rail so that torque is generated in the guide rail in a direction in which the guide rail is pressed against the first guide roller and the second guide roller. Features.
With such a configuration, it is possible to provide a seam welding copying apparatus that can ensure a stable guide function with a simple structure without restricting the workpiece shape.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the actuating means that operates such that the distance between the first guide roller or the second guide roller is separated or close to each other for a predetermined size and for a predetermined time. It is provided.
By adopting such a configuration, the operation means of the roller is operated for a certain period of time without correcting the guide rail for the deviation from the target welding locus of the electrode roller caused by the variation in the melting degree of the welded portion on the welding path. It is possible to effectively correct by finely adjusting the relative direction of the electrode roller to the workpiece.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, in order to alleviate a shock generated in the first guide roller when the first guide roller moves from the corner portion of the guide rail to the straight portion. A shock absorbing roller is disposed adjacent to the first guide roller.
According to this configuration, the shock caused by the operation of the corner portion can be alleviated, so that stable seam welding can be performed and the durability of the welder is improved.

The seam welding apparatus according to the present invention has a processing freedom that can accommodate small R corners and corners that protrude inward with a simple configuration, and can easily finely adjust the direction of the electrode roller, and is stable. Can be ensured.

1 is an overall view of a seam welding apparatus including a seam welding copying apparatus according to the present invention. It is a conceptual diagram (plan view, arrow AA) of the seam welding copying apparatus according to the present invention. It is a conceptual diagram (front view) of the seam welding copying apparatus according to the present invention. 4 is an enlarged view of upper and lower electrode rollers and first and second guide roller portions of the seam welding copying apparatus according to the present invention. 4-a indicates before the trajectory correction, and 4-b indicates after the trajectory correction. The operation of the first and second guide rollers in contact with the guide rail when the electrode roller track is corrected is shown. 5-a indicates before the trajectory correction, and 5-b indicates after the trajectory correction. The operation | movement of the 1st, 2nd guide roller and cushion roller in a guide rail corner part is shown. A conventional example is shown.

  FIG. 1 illustrates the entire seam welding apparatus 1 employing the seam welding copying apparatus 9 of the present invention. Although a commercially available seam welding apparatus is used as the basic structure, the portion related to the seam welding copying apparatus 9 adopts the novel structure according to the present invention.

  The seam welding apparatus includes a power supply unit with a built-in power supply, an electrode unit composed of two roller electrodes 5 and 6, an air cylinder A3 and a guide unit 4 that pressurizes the electrodes up and down, an operation panel 10 with a built-in control unit, etc. Consists of The seam welding copying device 9 is arranged at the lower end of a work gripping table 26 composed of a work support device 20 and a work clamp 21, and guide rails 24, two support arms 31, 33 and 3 for guiding the movement of the work. It is composed of two support shafts 30, 32, and 34, and is composed of a work table support device 35 that supports the work gripping table 26 movably in the horizontal X and Y directions. Hereinafter, these operations will be described.

The workpiece gripping table 26 is held at a position where the standby position detection sensor 8 acts on the sensor cam face 25 and the standby position is detected at the start of work.
As the work, an exhaust system main silencer or a fuel tank, which is composed of upper and lower shells and seam welds the surrounding flange portion, is suitable. In this embodiment, an exhaust system main silencer is applied. The workpiece 11 (main silencer) is placed on the workpiece support device 20 by an operator or a robot hand in a state where the upper shell and the lower shell are combined in the previous process and the surrounding flange portions are spot welded and integrated. Is done. A product receiving portion corresponding to the shape of the workpiece is disposed in the workpiece support device 20 and is configured to be positioned by placement.

  When the work 11 is placed on the work support device 20 and the operator gives an instruction to start work using the operation panel 10, the work clamp 21 is lowered by the operation of the air cylinder B. Since the workpiece clamp 21 is formed corresponding to the shape of the workpiece 11, the workpiece clamp 21 comes into close contact with the workpiece, and the workpiece is securely fixed to the workpiece support device 20. Subsequently, the upper electrode roller 5 is lowered by the operation of the air cylinder A, and the welding can be started in a state where the flange portion of the workpiece 11 is sandwiched between the upper electrode roller 5 and the lower electrode roller 6.

  Subsequently, a welding current having a predetermined waveform is supplied to the upper and lower electrode rollers from a power supply installed in the power supply unit by a signal from the control circuit. At the same time, the upper and lower electrode rollers are driven by the operation of the rotational drive transmission roller 7 in contact with the upper and lower electrode rollers 5 and 6, respectively, and the flange portion on the outer periphery of the shell is continuously seam welded. The upper and lower electrode rollers are fixed to the main body, and seam welding is performed along the desired trajectory while moving the workpiece 11 placed on the workpiece gripping table 26 that is movable in the horizontal direction by the driving force of the electrode roller. I will go.

  On the other hand, as described above, seam welding is performed while the workpiece 11 is gripped by the workpiece support device 20 and the workpiece clamp 21, but the workpiece gripping table 26 that supports the workpiece support device is arranged at the center as shown in FIG. The workpiece support shaft 34 is rotatably supported. The work support shaft 34 is supported by the intermediate support shaft 32 through the support arm B33, and the work clamp 21 is also supported by the intermediate support shaft 32 through the work clamp support arm 23. The intermediate support shaft 32 is supported by a device-side support shaft 30 fixed to the seam welding device 1 via a support arm A31. With these configurations, the entire workpiece gripping table 26 can be freely moved in the horizontal X and Y directions while freely rotating.

  As shown in FIG. 3, the workpiece gripping table 26 includes an upper surface portion on which the workpiece support device 20 is fixedly supported, and a skirt portion including a guide rail and a cam. A cam surface is formed above the skirt portion, and a signal necessary for control such as a standby position is generated by interaction with a sensor installed on the seam welding apparatus side.

  A guide rail 24 is formed at the lower end of the skirt portion. As shown in FIGS. 2 and 3, the first guide roller 41 is disposed outside the guide rail, and the second guide roller 42 is disposed so as to contact the guide rail 24 inside. Both guide rollers are configured such that the shaft center is fixed to the seam welding apparatus 1 by a bracket, and the work gripping table 26 is guided in a predetermined direction by interaction with the guide rail 24.

As shown in FIG. 5, the two guide rollers 41 and 42 are staggered so that the second guide roller 42 precedes the first guide roller 41 in the moving direction of the guide rail 24. At this time, the angle between the straight line connecting the centers of the two rollers and the center line of the annular guide rail, that is, the angle θ shown in FIG. Is arranged.
Further, a cushion roller 43 is disposed behind the first guide roller 41.

  The guide rail 24 is configured to apply torque to the guide rail 24 so that the guide rail 24 is always pressed against the two guide rollers 41 and 42. Specifically, as shown in FIG. 2, a wire 27 having one end connected to a work support shaft 34 is connected to a weight 29 via a plurality of pulleys 28, and a predetermined force is applied to the work support shaft by gravity acting on the weight 29. 34 to act on. Since the wire is arranged so that the force acts in a direction substantially parallel to the straight portion of the guide rail in the horizontal direction, the counterclockwise moment is always constant in plan view with the center point between the two guide rollers 41 and 42 as the center. In addition, the guide rail is effectively pressed against the guide roller. In addition, since the workpiece support shaft 34 is disposed substantially at the center of the workpiece gripping table 26, the torque fluctuation due to the posture of the workpiece gripping table 26 is suppressed.

  Further, the shape of the guide rail 24 is obtained by obtaining an envelope drawn by the outer edge of the roller when the two guide rollers 41 and 42 arranged in a staggered manner are drawn along the outer peripheral flange portion so as to draw a target welding trajectory. Can be set.

  The effect of setting the angle θ from 40 degrees to 60 degrees will be described. If the angle θ exceeds 60 degrees, the influence of the deviation of the center of the roller on the deviation in the direction of the guide rail 24 increases, and the operation is not possible. Become stable. On the other hand, when the angle θ is smaller than 40 degrees, the distance between the rollers becomes excessive, and it becomes difficult to design a compact corner portion of the guide rail 24. Therefore, by setting the angle θ from 40 degrees to 60 degrees, it is possible to maximize the effect of the copying apparatus according to this configuration.

  Next, the operation of the cushion roller 43 will be described. At the corner portion, a large rotational moment is generated in the entire work gripping table 26 including the guide rail 24. In the cam transition portion at the corner exit, the operation is suddenly changed from the rotational motion to the linear motion, so that a large force is applied to the first guide roller 41 as shown in FIG. Operation is likely to become unstable. By disposing the cushion roller 43, the cushion roller 43 comes into contact with the guide rail in advance of the first guide roller 41 in the transition portion of the guide rail, and the rotational moment of the work gripping table 26 is reduced by the shock absorbing function of the cushion roller. Absorb. Thereby, stable processing can be realized.

  Next, a method for correcting the welding direction with this configuration will be described. Seam welding is guided to a predetermined welding locus by the function of the copying apparatus, and therefore basically does not require correction. However, since the welded portion is melted by seam welding, there are cases where the degree of melting varies between the flange end direction and the body direction. Normally, the degree of melting on the flange end side increases, so a force to escape in this direction acts on the electrode roller, the direction of the electrode roller shifts in the direction of the flange end at a specific location, and the welding path deviates from the predetermined track. It may come off. In many cases, this cannot be predicted unless the cam is manufactured and actually operated. In the past, the cam has been modified to cope with the deviation of the trajectory, so that an additional cost and period are required. This configuration is an idea that has been conceived from such a background, and the trajectory is corrected by a simple method in which one electrode roller is moved for a predetermined time.

  That is, as shown in FIG. 4, the first guide roller is displaced by about 5 mm in a direction away from the guide rail 24 through the roller displacement link by the operation of the air cylinder C46 for several seconds, and the guide rail 24 is advanced toward the traveling direction. Then, the air cylinder C46 is returned and the first guide roller is returned to the original position. Thereby, the direction of the electrode roller is relatively corrected in the direction of the work body, and the track of the electrode rollers 5 and 6 is corrected.

  On the other hand, in the conventional arrangement in which the two guide rollers are the shortest distance, the sensitivity of the guide rail posture variation with respect to the movement of the guide rollers is large, and a large driving force is required for the operation and an accurate operation becomes difficult. This method is not applicable. This configuration, in which two rollers are arranged in a staggered manner, makes it possible for the first time to accurately adjust the relative direction of the electrode roller by moving the guide roller.

As described above, since the smooth operation is ensured even in the corner portion by the operation of the seam welding copying apparatus according to the present invention, high-quality seam welding can be performed over the entire circumference without requiring adjustment of the operator. Can be done. In addition, in a portion where the flange is interrupted, such as a portion through which an exhaust inlet and outlet pipe penetrates, all-round seam welding can be continuously performed by a known configuration such as a dummy flange formed in the product receiving portion.
When all-around welding is completed, the standby position confirmation sensor 8 is activated, the rotation drive transmission roller 7 is stopped, and the operations of the upper electrode roller 5 and the lower electrode roller 6 are stopped. Subsequently, the upper electrode roller 5 is raised by the operation of the air cylinder A, the workpiece clamp 21 is raised by the operation of the air cylinder B, and the seam welding apparatus 1 is in a standby state with the workpiece 11 opened.

  By repeating the above operations and simply replacing the workpiece, high-quality all-around automatic welding can be performed quickly and quickly.

1 Seam Welding Device 2 Power Supply 3 Air Cylinder A
4 Guide unit 5 Upper electrode roller 6 Lower electrode roller 7 Rotation drive transmission roller 8 Standby position confirmation sensor 9 Seam welding copying device 10 Operation panel (control device)
11 Work 20 Work support device 21 Work clamp 22 Air cylinder B
23 Work clamp support arm 24 Guide rail 25 Sensor cam face 26 Work gripping table 27 Wire 28 Pulley 29 Weight
30 Device side support shaft 31 Support arm A
32 Intermediate support shaft 33 Support arm B
34 Work support shaft 35 Work table support device 41 First guide roller 42 Second guide roller 43 Cushion roller 44 Support point 45 Roller moving link 46 Air cylinder C

Claims (3)

Two or more workpieces in an overlapped state having an annular welded portion at the periphery are supported by the workpiece support portion, and an annular guide rail having the same shape or similar shape to the welded portion is provided in the vicinity of the workpiece. The first guide roller is disposed on the outer peripheral surface of the guide rail, the second guide roller is disposed on the inner peripheral surface so as to face each other, and is integrally disposed with the electrode roller. In a seam welding copying apparatus that performs seam welding with a pair of electrode rollers on the welded part by guiding the guide roller while sandwiching the annular rail,
The two guide rollers are arranged such that a straight line connecting the center of the first guide roller and the center of the second guide roller forms 40 to 60 degrees with the center line of the annular guide rail,
Seam welding characterized in that biasing means for biasing the guide rail is provided so that torque is generated in the guide rail in a direction in which the guide rail is pressed against the first guide roller and the second guide roller. Copy device. The first guide roller or the second guide roller is provided with an actuating means that operates so that the distance between the first guide roller or the second guide roller is a predetermined size and a predetermined time.
The seam welding copying apparatus according to claim 1. A shock absorbing roller is disposed adjacent to the first guide roller in order to alleviate a shock generated in the first guide roller when the first guide roller moves from the corner portion of the guide rail to the straight portion. Characterized by the
The seam welding copying apparatus according to claim 1 or 2.

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