JPH0775779B2 - Saddle type tank seam welding line automatic copying device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel tank manufacturing apparatus for automobiles, and in particular, a flange portion continuously formed in the three-dimensional direction around the body of a saddle type tank via a rotary electrode for seam welding. The present invention relates to a seam welding automatic copying device which is useful when performing circumferential seam welding.

[0002]

2. Description of the Related Art In a saddle type tank, for example, as shown in FIG. 4, upper and lower press tanks A and B are combined into a middle shape, and a horizontal straight flange S is formed around the tank body.
And a saddle-shaped flange R that rises around the radius in the vertical direction outside including the corner flange C, so-called 3
It is manufactured by seam welding the entire circumference of the dimensional flange portion.

Conventionally, an apparatus for automatically copying and welding a workpiece to be welded of this kind has been disclosed, for example, in Japanese Utility Model Publication No. 58-36453.
The seam welder described in Japanese Patent Publication is known.

This seam welding machine has been proposed by the applicant of the present invention, and this apparatus holds a flange portion formed around the object to be welded between a pair of upper and lower seam electrodes. ,
When this is welded while rotating in a plane substantially perpendicular to the electrode by driving the seam electrode, a rotatable link to be connected to the device and a rotation rotatably held at the tip of the link. And a work table for supporting the object to be welded on the upper surface of the table.
It is installed so that it can be tilted at an arbitrary angle from the horizontal plane, that is, in a so-called so-called type in which both ends move up and down alternately.

However, in the conventional device of this type, when the object to be welded swings up and down around the center of the radius R in the vertical plane from the horizontal plane, that is, around the rotation fulcrum, the work force of the electrodes causes the work cradle to move. When tilting, depending on the size and weight of the work piece, the electrode rotation speed and the work piece rotation speed do not match, and if the welding speed changes or slips The welding line is misaligned, and sometimes the flange portion is tilted and an excessive driving force is applied to the flange, which may cause bending and electrode de-ringing.Thus, the 3D welding line is always smooth regardless of the size and weight of the workpiece. There was still a problem to be solved in order to guide to.

[0006]

The problem to be solved by the present invention is that a saddle-shaped tank or the like rises in the vertical direction of a saddle-shaped tank in an apparatus for automatically copying and welding weld lines in three-dimensional directions. This is the point where the speed of rotation around the radius R and the electrode peripheral speed are not synchronized when the saddle-shaped flange of radius R is tilted through the rotation fulcrum.

[0007]

SUMMARY OF THE INVENTION Therefore, according to the present invention, there is provided a saddle-shaped tank 3 which comprises a saddle-shaped flange formed in a vertical plane, a corner flange formed in a horizontal plane, and a straight flange. A copying apparatus in which a flange portion in the dimensional direction is sandwiched by a pair of rotating electrodes for seam welding, and the saddle type tank is moved in the three-dimensional direction by the driving force of the rotating electrodes while guiding the flange portion between the electrodes. A rotatable link mechanism provided in the main body of a seam welding machine having the above-mentioned rotary electrode for seam welding, a rotary table rotatably provided at the tip of the link mechanism, and the rotary table. Mechanism for guiding the rotation and linear movement of the table, a work cradle that tilts about the rotation fulcrum on the upper surface of the table, and a clamp that holds the saddle-shaped tank set on the work cradle. Device and saddle A stopper device is provided which detects when the center of the radius R of the flange reaches or passes a predetermined position (that is, when rotation ends) and stops or cancels the movement of the rotation table by the detection signal. After the rotation table is stopped by this stopper device, when the pedestal tilts along the saddle-shaped flange, the drive device for auxiliary driving the work pedestal in synchronization with the rotation speed of the electrode. Is provided.

Further, the rotation table is provided with a sensor for detecting the timing for releasing the stop of the stopper device.

Further, the clamp device clamps the work piece to be welded on the work cradle and also has a radius R of the saddle-shaped flange.
There is provided a copying mechanism that tilts with the movement of.

Further, the clamp device is provided with a pressure adjusting means for varying the clamp pressure according to the movement of the object to be welded.

[0011]

[Operation] In the present invention, when the pedestal tilts along the saddle-shaped flange, the work cradle is supplementarily driven in the tilting direction in synchronization with the rotational speed of the electrode.
The object to be welded can be swung at a speed that matches the rotational speed of the electrode regardless of the size and weight of the object to be welded, and changes in the welding speed and slippage can be prevented. Further, when the center of the radius R of the saddle-shaped flange reaches a predetermined position, this is detected, and the movement of the rotary table in the forward direction is stopped by the detection signal to stop the work along the shape of the saddle-shaped flange. Since the pedestal is tilted, the saddle type welding line can be smoothly guided without applying the excessive force of the electrode to the saddle type flange portion during welding, thereby improving the welding quality of three-dimensional welding.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the device of the present invention will be described below with reference to the drawings. 1 is a schematic front view showing the entire seam welding automatic copying apparatus of the present invention. FIG. 2 is a plan view showing the main part of the device of the present invention. FIG. 3 is a front view showing the main part of the device of the present invention.

The seam welder 1 is composed of well-known components, and basically, an upper arm and a lower arm fixed to the main body.
Rotating electrodes for seam welding, which are supported by
3, a pressurizing cylinder 4, a welding transformer, a secondary conductor, etc. (not shown).

The seam welding automatic copying device 5 is combined with a seam welding machine and comprises a link mechanism 6 which is rotatably connected in the horizontal direction through a plurality of joints, and a horizontal end of the link mechanism. Rotation table 7 rotatably supported in any direction
And a work cradle 9 installed on the upper surface of the rotary table so that both ends thereof can be tilted alternately through a rotary fulcrum 8, and a work cradle is set on the lower surface of the rotary table. A band-shaped copying cam 10 in which a welding line of a flange portion including a straight flange and a corner flange formed in a horizontal plane of a saddle-shaped tank is approximately formed, and a plurality of copying cams located outside the copying cam 10 are provided. The guide pins 11 fixed at predetermined positions of the respective corner portions and a pair of guide rollers for sandwiching and guiding the copying cam 10 from both sides at a position below the electrode passing on the pressure center line of the electrode. Rotating table 7 installed in a direction intersecting with the electrodes 12 and 13 at right angles to the electrode pressing center line.
Guide pin 15 that guides the rotary table in a straight line direction by the guide groove that has passed over the ratchet 14 and entered when rotating, and the work to be welded set on the work cradle 9 should not move from above. And a clamping mechanism 16 for clamping and holding, and all of these components are well known in the related art. The copying cam 1
0, the guide pin 11, the guide rollers 12 and 13, the guide rail 15 and the like are collectively referred to as a guide mechanism.

In the present invention, a driving device 20 such as a cylinder or an electric motor for auxiliary driving the work receiving base 9 is added around the rotation fulcrum 8 of the receiving base 9. Here, a hydro cylinder is used as this drive device. The rotation fulcrum 8 of the work cradle is located, for example, at a substantially central position of the work cradle 9 with a common shaft 18 supported by bearings of support brackets 17 fixed on both sides of the upper surface of the rotary table 7. It is inserted in the bearings provided on both sides of the shaft, and the work receiving base 9 tilts around this shaft 18. In other words, this work cradle supports the radius R of the saddle-shaped flange.
When tilted along the direction, both ends move up and down in a so-called seesaw type.

According to the present invention, when the object to be welded is tilted along the radius R of the saddle-shaped flange, that is, when the center of the radius of the saddle-shaped R comes to the welding position of the upper and lower electrodes, the forward direction of the rotary table is increased. A stopper device 19 for immediately stopping the movement is provided. For example, as shown in FIG. 2, this stopper device 19 is actuated by a sequence when the leading corner flange is completely rotated, or the sensor SX1 fixed at a predetermined position has a predetermined rotation table. It operates when the stopper pin P1 or the sensor dog fixed at the position is detected. In this case, the stopper device 19 is operated by the sequence, and the stopper block 28 is applied to the guide pin P1 or P2 to rotate the tape. It is a mechanism to stop the progress of Bull 7.

The hydro-cylinder of the drive unit 20 receives a command signal from the sensor SX1 when the radial center of the saddle-shaped sludge reaches a predetermined position after the stopper unit 19 has been activated, and synchronizes with the rotation speed of the electrodes. The driving of the cradle 9 is started. Further, the final position of the radius R of the saddle type flange is detected by the sensor SX2 provided at a predetermined position of the rotary table 7 (or the ending position of the saddle type flange symmetrically formed on the opposite side is detected by the sensor SX3). At this time, a release signal is sent from the sensor SX2 or the sensor SX3 to the stopper device 19, the stopper block 28 is pulled back, and the stopper pin P1 or the stopper pin P2 is released from the stopper position to restart the movement of the rotary table 7. To do. As described above, in the case of this embodiment, the three sensors can be used to detect the stop or release of the rotary table 7 and the start of the drive of the work cradle 9 in good timing.

Further, in the present invention, the device 16 for clamping the object to be welded on the work cradle is provided with a copying mechanism which tilts with the movement of the radius R of the saddle type flange. As shown in FIG. 1, for example, this copying clamp device is provided with a circular arc groove 24 adapted to a saddle-shaped R radius of a cam plate 23 that is swingably connected to a tip of a rod 22 of a clamp cylinder 21,
The clamp plate 25 is supported via a roller 26 so as to be able to reciprocate. Although not shown in the drawing,
The clamp plate 25 has a mechanism in which, for example, a roller 26 is inserted into a stopper groove provided in the arc groove so that the clamp plate 25 does not shift in position when opened in the original position. Further, the clamp device 16 is provided with pressure adjusting means (not shown) for varying the clamp pressure according to the movement of the object to be welded. That is, the clamp pressure is controlled by, for example, the timing signals from the above-mentioned three sensors SX1 to SX3 depending on the timing signals for stopping and releasing the rotation table 7 when welding the radius R of the saddle-shaped flange.
Clamping pressure is weakened in order to reduce the movement of the rotation fulcrum 8 by the detection signal, and when the rotation is completed, it is strongly clamped in order to firmly hold the work piece in the movement within the other plane by the detection signals of the sensors SX2 to SX3. You can do it. Although illustration is omitted in this example, actually, an electromagnetic valve or an electropneumatic proportional valve or the like is provided in the air circuit of the clamp cylinder, and the clamp pressure is varied by controlling this with an electric signal from the outside.

Further, the link mechanism 6 is provided with a floating cylinder 27 for keeping the flange portion of the work piece at a constant welding position when the electrode pressing position changes due to wear of the electrode pressing surface. It is provided at the joint portion of the link arm 30 that supports the rotary table. The link mechanism also includes a cylinder 29 that shares a function of auxiliary driving of the link drive when the rotary table is rotated and a drive function of returning the rotary table to the original position when the rotary table is opened. It is connected between 31 and the welder body 1.

The operation of the apparatus of the present invention having the above-described structure will be described. First, the copying apparatus 5 is made to stand by at the original position with the clamp plate 25 of the clamp apparatus 16 opened.
A saddle type tank is set on the work cradle 9 and the welding start position in the horizontal plane is inserted between the electrodes and clamped.

Thus, when the pressurizing cylinder 4 is operated to lower the upper rotary electrode 2 to clamp the welding start position, the electrodes are rotated and a welding current is caused to flow between the electrodes to start the seam welding. The electrode driving force guides the two-dimensional welding line of the flange portion between the electrodes while the rotating table 7 moves in the horizontal direction in the horizontal plane together with the link mechanism 6. In this case, the guide pin 11 is used for linear welding of the flange portion.
When the ratchet 14 is completely turned around, the ratchet 14 is pushed down from a predetermined position of the guide rail 15 to get over and enter the groove, and is guided by the copying cam 10 and the guide pin 11 sandwiched between the guide rollers 12 and 13. The curved welding of each corner of the flange is a guide pin 1 that guides the linear welding.
1 disengages from the predetermined position of the guide rail 15, and guides the corners of the copying cam 10 by sandwiching it from both sides by the guide rollers 12 and 13.

Next, when the saddle-shaped flange rising in the vertical plane is to be subjected to the curved welding with the radius R, the preceding corner is used.
When the flange is fully rotated, the cylinder of the stopper device 19 projects the stopper block 28 from the direction perpendicular to the guide rail 15 by the sequence control, interrupts the passage of the next stopper pin P1, and stands by. The guide pin 11 advances in the groove of the rail, and the stopper pin P1 is blocked at the stopper position 19 to stop the linear movement of the jig and the link such as the rotary table, and at the same time, to make the stop position a saddle radius R. The sensor SX1 detects this as the center position of the actuator, and the drive device 20 is operated by the detection signal, and the hydro-cylinder adjusts the work cradle 9 to the peripheral speed of the electrode from the horizontal position to the inclination angle of the saddle type flange. Drive. At the same time, the clamp pressure is switched to a weaker direction by the signal from the previous sensor SX1, and the rotation of the work cradle 9 is started. Smooth the induction between. Then, the end point of the saddle R radius is detected by the sensor SX2.
When is detected, the stopper device 19 is released by the signal,
At the same time when the rotary table 7 starts to move forward in the horizontal plane again, the signal from the sensor SX2 switches the clamping pressure to the higher direction, and the welding line in the horizontal plane is guided while the workpiece is firmly fixed. The guiding operation of the saddle type welding line is similarly performed when welding the saddle type flange on the opposite side of the tank. In this case, the end point of the saddle shape R radius is detected by the sensor SX3.

[0023]

As described above, according to the apparatus of the present invention, when the welding line in the three-dimensional direction including the radius R of the saddle type flange of the saddle type tank which is a kind of fuel tank for automobiles is profile welded. In addition, when the pedestal tilts along the saddle-shaped flange, the work pedestal is supplementarily driven in the tilting direction in synchronization with the rotation speed of the electrode, so that the size and weight of the workpiece can be reduced. It is possible to prevent the welding speed from changing and slipping by swinging the object to be welded regardless of the peripheral speed of the electrode. Further, it is possible to easily and accurately control stop of the rotary table in the forward direction and start of movement by detecting the timing of tilting the work cradle around the radius R of the saddle-shaped flange and the end of the saddle-shaped curve. In addition, the clamp pressure can be lightened when tilting the work cradle, and the other parts can be clamped stronger than this. Smooth movement is possible, and the quality of three-dimensional seam welding including a saddle-shaped weld line can be improved by combining these.

[0024]

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a seam welding machine having a device of the present invention.

FIG. 2 is a plan view showing an embodiment of the device of the present invention.

FIG. 3 is a front view showing an embodiment of the device of the present invention.

FIG. 4 is a perspective view showing the external appearance of a saddle type tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 seam welder 2 rotary electrode for seam welding 3 rotary electrode for seam welding 4 pressure cylinder 5 seam welding automatic copying device 6 link mechanism 7 rotary table 8 rotary fulcrum 9 work receiver Table 10 Copying cam 11 Guide pin 12 Guide roller 13 Guide roller 14 Ratchet 15 Guide rail 16 Clamp mechanism 17 Support bracket 18 Shaft 19 Stopper device 20 Drive device 21 Clamp cylinder 22 Rod 23 Cam plate 24 Arc groove 25 Clamp plate 27 Cylinder 28 Stopper block SX1 sensor SX2 sensor SX3 sensor

Claims (3)

[Claims] 1. A three-dimensional flange portion of a saddle-shaped tank, which comprises a saddle-shaped flange formed in a vertical plane, a corner flange and a straight flange formed in a horizontal plane, which are continuous with each other. A seam welding sandwiched by a rotary electrode for welding, and a driving device for guiding the flange portion between the electrodes while moving the saddle-shaped tank in the three-dimensional direction by the driving force of the rotary electrode. -A rotatable link mechanism provided in the main body of the aluminum welding machine, a rotary table rotatably provided at the tip of the link mechanism, and a guide mechanism for guiding the rotation and linear motion of the rotary table, The above
It has a work cradle that tilts about the rotation fulcrum on the upper surface of the bull and a clamp device that clamps and holds the saddle-shaped tank set on this work cradle, and the center of the radius R of the saddle-shaped flange is When it reaches or passes a predetermined position,
A stopper device for detecting this and stopping or canceling the movement of the rotary table by the detection signal is provided. After stopping the rotary table by this stopper device, the pedestal tilts along the saddle-shaped flange. Occasionally, a seam welding line automatic copying device for a saddle-shaped tank provided with a drive device for auxiliary driving of the work cradle in synchronization with the rotation speed of the electrode. 2. A member for directly clamping an object to be welded of a work cradle in the clamping device comprises a radius R of a saddle-shaped flange.
The seam welding line automatic copying apparatus according to claim 1, which is capable of tilting in accordance with the movement of the. 3. The automatic seam welding line copying device according to claim 2, wherein said clamping device has a pressure adjusting means for varying a clamping pressure.