JPH0421658Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention has one end pivoted on the side of the seam welding machine and is supported by a pivot support member provided at the other end of the articulated arm connected by several joints. A workpiece to be welded having several corners on a welding line is supported on a copying stand attached to a rotating member, and the welding line is sandwiched between a pair of rotating welding electrodes of a seam welding machine and welding is performed, In the seam welding machine, the feed is advanced by the rotation of the rotating welding electrode pair, and the articulated arm is provided with an auxiliary cylinder that pulls the copying table in the direction of the rotating welding electrode pair, and the corner portion is provided with a copying pin on the copying rail. The pressure in the auxiliary cylinder is detected by a limit switch when it collides with the cam-like protrusion, and the pressure in the auxiliary cylinder is increased by actuating an electro-pneumatic proportional valve inserted in the cylinder's fluid circuit, thereby causing rotation of the corner of the workpiece. This invention relates to an automatic auxiliary cylinder pressure switching device for a seam welding machine that returns the pressure of the auxiliary cylinder to the original pressure when the welding process is completed.

(Prior art) An automatic auxiliary cylinder pressure switching device of a seam welding machine compared with the present invention, in other words, a copying pin is provided at each corner of the planned welding line of the workpiece, and the copying pin is provided in a cam shape on a rail. At the same time as it abuts the protrusion, a lever is pressed by the copying pin, and a limit switch is pressed and activated by the lever. There is no conventional device that can perform the required action.

(Problems to be solved by the present invention and purpose of the invention) One end is pivotally supported on the side of the seam welding machine, and the other end of the articulated arm is connected by several joints, and is attached to a rotating member supported by a pivot member at the other end. A work piece to be welded having a corner portion on the planned welding line is supported on a copying table, a copying pin corresponding to the corner of the planned welding line of the workpiece is provided on the copying table, and the planned welding line is moved by the seam welding machine. An auxiliary cylinder is provided between the pair of rotating welding electrodes to perform welding, rotate the copying pin against a cam-shaped protrusion provided on the copying rail, and pull the copying table in the direction of the pair of rotating welding electrodes on the articulated arm. In a connected seam welding machine, if the auxiliary cylinder is applied at a low constant pressure when the workpiece rotates at a corner, the welding at the corner will deviate from the planned welding line, and sometimes the welding curve at the corner will not match the workpiece. It has the disadvantage of becoming unwelded in parts if it comes off, so constant monitoring is required.

The object of the present invention is to improve the above-mentioned drawbacks and to automatically increase the pressure of the auxiliary cylinder when the workpiece to be welded and the copying table rotate at a corner to prevent welding from occurring.

(Means for Solving the Problems) The automatic auxiliary cylinder pressure switching device for a seam welding machine of the present invention is designed to meet the above-mentioned purpose, and specifically has one end pivoted on the side of the seam welding machine. The workpiece to be welded, which has a corner portion at the planned welding line, is supported on a copying table that is attached to a rotating member supported by the shaft supporting member at the other end of the articulated arm connected by several joints, and the planned welding line is aligned. Welding is carried out between a pair of rotating welding electrodes of a seam welding machine, and the copying pin is brought into contact with a cam-shaped protrusion provided on the copying rail to rotate the copying table, and the copying table is rotationally welded to the articulated arm. In a seam welding machine formed by connecting an auxiliary cylinder that pulls in the direction of a pair of electrodes, a lever 32 and its lever 3 are pressed by contact with a copying pin 17.
A limit switch LS is provided which is pressed by 2.
An electro-pneumatic proportional valve 52 is interposed in the fluid circuit 51 of the auxiliary cylinder 20, and the electro-pneumatic proportional valve 52 is actuated by the on signal from the lever of the limit switch LS, supplying high pressure fluid to the auxiliary cylinder 20. Then, the joint arm is pulled in the direction mentioned above to stabilize the welding at the corner part, and as the welding progresses, the copying pin 17 separates from the abutment of the cam-shaped protrusion 4a, releasing the limit switch LS from the pressure by the lever 32, The feature is that the auxiliary cylinder 20 is returned to its original state.

A preferred embodiment of the invention will be described in the following section.

(Embodiment) The accompanying drawings show an embodiment of the present invention, and FIG. 1 is a front view of a seam welding machine, and FIG. 2 is a plan view of the same, with a portion cut away to show only the outline. FIG. 3 is an enlarged side view, FIG. 4 is a partially enlarged front view, FIG. 5 is a partially enlarged plan view, and FIG. 6 is a layout diagram of the fluid circuit.

The seam welding machine 1 includes a pair of rotating welding electrodes 2 and 3, a tracing rail 4, and a first arm 7 and a second arm with one end pivoted on the welding machine 1 side as shown in FIG. A copying table 11 is attached to a rotary member 10 which is rotatably supported by being inserted into a shaft support member 9 at the other end of the joint arm 5, and a sliding rod is mounted on the copying table 11. 14 inserted into the guide 12 of the copying table 11
3, a weldment workpiece mounting stand 13 with a sliding rod 14 inserted through the guide 12 of the copying table 11 is installed, and projecting walls 15 for positioning the workpiece to be welded are provided around the four circumferences of the stand 13. A copying engagement plate 16 shown in FIG. 3 is fixed to the plate, and several copying pins 17 are protruded from the bottom surface. Each copying pin 17 is provided with a cutout groove 18 as shown in FIG. 19 is a welding object mounting stand 13
The welding edge is hung on the positioning projecting wall 15 as shown in FIG. 3, and the planned welding line of the welding edge is sandwiched between the rotating welding electrodes 2 and 3 to be welded, such as a fuel tank for a vehicle.

In this embodiment, the planned welding line of the object to be welded 19 has four corners, and each copying pin 17 is provided at the center of each corner.

The first arm 7 of the articulated arm 5 has a rod 21 of an auxiliary cylinder 20 that pulls the workpiece 19 toward the rotating welding electrodes 2 and 3 via the shaft support member 9, the rotating member 10, the copying table 11, etc. Connect as shown in Figure 2.

In FIG. 3, the copying table 11 engages with the engagement groove 40 of the copying rail 4 provided at the lower part of the rotating welding electrodes 2 and 3, moves the engagement plate 16 together with the workpiece 19, and moves the engagement plate 16 to the copying rail 4. Provided cam-shaped protrusion 4a
When the corner of the object to be welded 19 is detected, the copying table 11, the object to be welded 19, etc. rotate by an amount of rotation corresponding to the angle of the corner, and the second
The copying pin 17 shown at the bottom of the figure is brought into new contact with the copying rail 4, and by repeating this process, welding of the workpiece 19 having a plurality of corners is completed.

In the present invention, in the above configuration, each copying pin 17
As shown in FIG. 4, a lever 32 having an upward slope 33 is pivotally supported by a shaft 31 at the lower part of the cam-shaped protrusion 4a that the cam-like protrusions 4a abut against, and an inverted L-shaped push rod is attached to the lower surface of the tip of the lever 32. 34 is fixed, and a vertical adjustment elongated hole 35 provided in the lower part of the push rod 34
The vertical position can be adjusted through the shaft 37 of the punching roll 36, and a limit switch LS is attached to the lower edge of the arm 39 which is attached to the lower part of the copying rail 4 in a hanging manner. The switch LS produces an on signal when pressed, and produces an off signal when the switch LS is released. A switch lever 41 is pivotally supported on the limit switch.

A double-acting spring 38 is provided on the lever 32, and the push rod 3
A stopper 43 is provided corresponding to the upper end of 4.
Others 42 are covers that cover parts of the lever 32 and the push rod 34.

FIG. 6 shows a fluid circuit 51 of the auxiliary cylinder 20, in which an electro-pneumatic proportional valve 52 is operated when the limit switch LS mentioned above is turned on.
A limit switch is installed with a solenoid switching valve 53 and
In response to the LS ON signal, high pressure fluid is sent to the auxiliary cylinder 20 to pull the articulated arm 5 with high pressure, and when the copying pin 17 rotates and the notch groove 18 becomes at an angle corresponding to the cam-shaped protrusion 4a, the copying pin 17 is rotated.
escapes from the upper surface of the lever 32, and at the same time, the switch lever 41 moves back and the limit switch is activated.
Issues an LS off signal and double-acts the electro-pneumatic proportional valve 52,
The fluid at the original low pressure is sent to the auxiliary cylinder 20.

(Function) As clarified by the explanation of the embodiments described above, the present invention provides a copying pin 1 provided on the lower surface of the copying table 11 in alignment with the corner of the weld line of the workpiece 19.
7 collides with the cam-shaped protrusion 4a of the copying rail 4, causing the pair of rotating welding electrodes 2 and 3, the object to be welded 19 and the copying table 11 to start rotating around the copying pin 17 in a known operation. , push the limit switch LS via the lever 32 with the copying pin 17,
The ON signal at that time activates the electropneumatic proportional valve 52, which increases the pressure in the auxiliary cylinder 20, and as the welding progresses, the copying pin 17 advances and the pressure on the lever 32 is released. The limit switch LS and the electropneumatic proportional valve 52 move back, causing automatic operation to return the pressure of the auxiliary cylinder 20 to its original low pressure.

(Effects) In the present invention, when the copying pin 17 detects a corner of the copying base 11 and the workpiece 19, the limit switch LS is simultaneously pushed via the lever 32, and the fluid circuit 51 of the auxiliary cylinder 20 is activated by the ON signal of the limit switch LS. Electropneumatic proportional valve 52 installed in
is activated to automatically increase the pressure acting on the auxiliary cylinder 20 and pull the articulated arm 5 with strong pressure to prevent the workpiece 19 sandwiched between the pairs of rotating welding electrodes 2 and 3 from coming off, and to move the workpiece 19 to the corner. The rotation is caused smoothly to stabilize the welding, and as the welding progresses, the rotation of the corner ends and the copying pin 1
7 releases the pressure on the lever 32, and the electro-pneumatic proportional valve 52 is moved back using the off signal at that time to return the pressure to the original state so that the auxiliary cylinder 20 does not pull the articulated arm 5 too much. cause the operation,
The planned welding line of the workpiece 19 is the rotating welding electrode 2, 3
The limit switch LS and the electro-pneumatic proportional valve 52 of the fluid circuit 51 ensure smooth welding, including the corners of the workpiece 19, and prevent welding failures. It has the effect of eliminating

[Brief explanation of the drawing]

The accompanying drawings show an embodiment of the present invention, and FIG. 1 is a front view of a seam welding machine, and FIG. 2 is a plan view of the same, with a portion cut away to show only the outline. FIG. 3 is an enlarged side view, FIG. 4 is a partially enlarged front view, FIG. 5 is a partially enlarged plan view, and FIG. 6 is a layout diagram of the fluid circuit. 1... Seam welding machine, 2, 3... Rotating welding electrode, 4... Copying rail, 4a... Cam-shaped protrusion, 5
... Joint arm, 10 ... Rotating member, 11 ... Copying table, 17 ... Copying pin, 19 ... Welded object, 2
0...Auxiliary cylinder, 32...Lever, LS...
Limit switch, 51... Fluid circuit, 52...
Electropneumatic proportional valve.

Claims (1)

[Scope of Claim for Utility Model Registration] A welding line is recorded on a copying table attached to a rotating member that is supported by a shaft supporting member at the other end of a jointed arm whose one end is pivotally supported on the seam welding machine side and connected by several joints. The object to be welded which has a corner part is supported, the planned welding line is sandwiched between a pair of rotating welding electrodes of a seam welding machine, welding is performed, and the copying pin is brought into contact with the cam-shaped protrusion provided on the copying rail. In a seam welding machine that rotates a copying table and connects an auxiliary cylinder to the articulated arm to pull the copying table in the direction of the rotating welding electrode pair, the lever 3 is pressed by contact with the copying pin 17.
2 and a limit switch LS pressed by its lever 32, an electro-pneumatic proportional valve 52 is interposed in the fluid circuit 51 of the auxiliary cylinder 20, and an on signal from the lever of the limit switch LS causes the electro-pneumatic proportional valve 52 to be pressed. , and sends high-pressure fluid to the auxiliary cylinder 20 to pull the articulated arm in the direction mentioned above to stabilize the welding of the corner portion, and as the welding progresses, the copying pin 17 comes into contact with the cam-shaped protrusion 4a. Limit switch away from
An automatic auxiliary cylinder pressure switching device for a seam welding machine, characterized in that the LS is released from pressure by a lever 32 and the auxiliary cylinder 20 is returned to its original state.