JPH0217753Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial field of application) The invention is based on the invention, in which a workpiece whose welding line consists of a straight line part and a circular arc part is held between an upper electrode and a lower electrode.
It relates to a seam welding machine that performs welding while rotating both electrodes and applying pressure and current, and more specifically, a seam welding machine that automatically guides the workpiece along the weld line of the workpiece. This relates to a guidance device.

(Prior Art) Conventionally, a welding object guiding device for a seam welding machine includes a guide rail attached to a seam welding machine body having an upper electrode and a lower electrode, and a guide rail that is engaged with the guide rail and guided to the seam welding machine body. It is known that the welding device is equipped with a rotary table that is movably and rotatably supported in a horizontal plane, and is configured to guide the workpiece along the welding line.

In a seam welding machine equipped with the above-mentioned workpiece guidance device, when welding a workpiece such as a gasoline tank whose welding line consists of a straight part and a circular arc part, the workpiece is placed on a rotary table. and guide the workpiece along the welding line, sandwich the workpiece between the upper electrode and the lower electrode, and perform welding while rotating both electrodes and applying pressure and current. There is.

By the way, when welding moves from a straight line to an arc, the object to be welded rotates along the welding line of the arc, but at this time, the object to be welded cannot fully rotate along the weld line of the arc. May cause weld defects. In order to solve this problem, the workpiece guidance device is equipped with
Some are equipped with a balance cylinder device that applies rotational force in a direction that assists the rotation of the workpiece.

FIG. 4 shows this. In the figure,
Reference numeral 1 denotes a balance cylinder device having a silencer 2, and a cylinder rod 1a of this cylinder device 1.
is connected to an intermediate portion of a first link arm 3, one end of which is pivotally connected to a seam welding machine main body (not shown). A rotary table (not shown) is provided on the second link arm 4 which is pivotally connected to the first link arm 3, and a workpiece to be welded is placed on the rotary table. On the other hand, the piston side chamber of the cylinder device 1 is connected to an air source 6 via a conduit 5, and the conduit 5 has a pressure reducing valve 7 and a safety valve 8 on its way.
is provided. In this device, when air is supplied from the air source 6 to the piston side chamber of the cylinder device 1 during welding of the workpiece, a constant force is applied to the rotary table in its rotation direction, and the weld line of the circular arc part of the workpiece is It is designed to allow sufficient rotation along the

However, with this method, considerable force is constantly applied in the opposite direction to the welding direction, not only when welding arcuate sections but also when welding straight sections, which may cause the welded section of the workpiece to melt. At this time, there is a problem in that the workpiece slips in the opposite direction to the welding direction, resulting in welding defects.

Therefore, when welding straight parts of the workpiece, it is preferable not to apply considerable force in the opposite direction to the welding direction, but if welding is performed in a completely free state, the workpiece will be guided Since there is slight play in the engagement portion between the rotary table and the guide rail of the device, meandering of the welding line is unavoidable, resulting in the same problem as the above-mentioned welding defect.

(Problems to be Solved by the Invention) The present invention attempts to solve the above-mentioned problems, and is a seam welding machine that can secure good guidance of the workpiece and thereby prevent welding defects. An object of the present invention is to provide a welding workpiece guiding device.

(Means for solving the problem) Therefore, the technical means of the present invention is to provide a balance cylinder device between the seam welding machine main body and the rotary table, and this cylinder device has A rotational auxiliary force biasing circuit that generates a small force in the rotational direction of the rotary table, and a reaction force that generates an even smaller force in the direction opposite to the traveling direction of the workpiece. The present invention is characterized in that it is switchably connected to the advancing direction force energizing circuit.

(Function) In such a configuration, when welding the arc part of the weld line of the workpiece, a rotational auxiliary force biasing circuit is connected to the balance cylinder device to rotate the workpiece with a force smaller than the moving force of the rotary table. The rotation of the table is assisted, whereby the workpiece to be welded can be rotated sufficiently smoothly along the welding line of the circular arc portion, and a good welding result can be obtained.

In addition, when welding a straight part of the welding line of the workpiece, a counter-progressive force biasing circuit is connected to the balance cylinder device, and a force even smaller than the above-mentioned rotational auxiliary force is applied to the workpiece in the forward direction of the workpiece. By applying force in the opposite direction, even if there is some wobbling in the engagement between the guide rail and the rotary table,
The straight part of the workpiece is guided without meandering along the weld line, and in addition, even when the weld is melted, it is possible to reliably prevent the workpiece from slipping in the opposite direction to the welding direction. .

(Example) An example of the present invention is shown below in Figures 1 to 3.
This will be explained based on the diagram. Support brackets 10 and 11 are fixed to the seam welding machine main body 9 and extend horizontally in parallel to each other. Seam welding machine body 9
An upper electrode 12 and a lower electrode 1 are placed at a suitable height position.
3 are provided rotatably. The upper electrode 12 is provided so as to be movable up and down in the direction AA' in the figure by a pressure cylinder (not shown) fixed to the upper part of the seam welding machine main body 9. The lower electrode 13 is
It is fixedly supported by a bracket (not shown) fixed horizontally to the seam welding machine main body 9, and connected to a rotational drive source (not shown).

Reference numeral 14 denotes a guide rail for guiding the welding lines of the objects W, W' to be welded, and is fixed horizontally to the distal end sides of the support brackets 10, 11 of the main body 9 of the seam welding machine. The guide rail 14 is formed with a guide groove 15 extending in its longitudinal direction. A cam stopper 16 is provided at a suitable position on the guide rail 14, and an arcuate portion 16 corresponding to the arc of a half-moon cam pin 28, which will be described later, is provided on the entry side of the camstopper 16.
a is formed. A plurality of ratchets 17 are provided on the upper surface of the guide rail 14 at intervals in the longitudinal direction so as to be freely retractable.

At the bottom of the guide groove 15, there is an in-situ ratchet 1.
8 is provided so that it can appear and disappear at will. The original position ratchet 18 is always resiliently biased upward by a spring (not shown), and has an inclined surface formed on the entry side of a half-moon cam pin 28 (described later). 19,19'
is a stepped portion formed on the other side wall of the guide rail 14.

A pair of brackets 20 and 21 are fixed to the support bracket 10 side of the seam welding machine main body 9 so as to be spaced apart from each other in the height direction. 22 is a jig movably attached to the seam welding machine main body 9,
A pair of brackets 20, 2 of the seam welding machine main body 9
1 of the jig 22 by the hinge pin 23.
One side end of the link arm 24 is connected to be rotatable in the horizontal direction. Further, one end of a second link arm 26 is connected to the other end of the first link arm 24 by a hinge pin 25 so as to be rotatable in the horizontal direction.

Reference numeral 27 denotes a rotary table rotatably supported on the upper part of the other end of the second link arm 26, and the rotary table 27 is configured to adjust the shape of the welding line consisting of a straight line portion and an arcuate portion of the workpieces W and W' to be welded. It is formed in a shape that is suitable for. A half-moon cam pin 28 is provided on the lower surface of the rotary table 27 at a position corresponding to the center of the arc of the weld line of the objects W, W' to be welded. The half-moon cam pin 28 engages with a cam stopper 16 provided on the guide rail 14 to move the workpiece W,
It has the role of guiding the arc part of the weld line W'. The half-moon cam pin 28 is positioned and fixed on the rotary table 27 so that the vertical surface of the U-shaped cam groove 29 formed therein is parallel to the straight part of the weld line to be welded following the circular arc part.

Reference numeral 30 denotes a copying plate that engages with the ratchet 17 provided on the upper part of the guide rail 14 to guide the straight part of the welding line of the objects to be welded W, W', and is fixed to the straight part of the outer periphery of the rotary table 27. It is installed. A pedestal 31 is provided above the rotary table 27 on which the objects to be welded W, W' are placed, positioned and fixed. The pedestal 31 has a plurality of floating mechanisms 32 attached to appropriate positions on the rotary table 27.
is elastically supported.

Reference numeral 33 denotes an arm fixed to a proper position of the second link arm 26. A hollow bracket 31 extending in the vertical direction is disposed on the horizontal portion of the upper end of the arm 33, and this bracket 34 is attached to the rotary table 2.
It is provided so as to coincide with the center line of 7. A clamp member 35 for clamping the objects W, W' to be welded is fitted into the hollow bracket 34 so as to be movable up and down. A clamp cylinder 36 for moving the clamp member 35 up and down is provided on the upper part of the bracket 34 and connected to the clamp member 35.

37 is the support bracket 1 of the seam welding machine main body 9
A bracket 37 is fixed in place on the zero side, and a piston side end of a balance cylinder device 39 is connected to the bracket 37 by a hinge pin 38 so as to be horizontally rotatable. A knuckle 40 is attached to the cylinder rod 39a of the cylinder device 39, and the knuckle 40 is attached to the first link arm 24.
It is rotatably connected in the horizontal direction via a hinge pin 42 to a bracket 41 fixed in place.

Therefore, when air is supplied to the piston side chamber of the balance cylinder device 39, the cylinder rod 39a of the cylinder device 39 expands, and this stretching force is transmitted through the first link arm 24 and the second link arm 26. The information is transmitted to the rotary table 27, which rotates as indicated by the arrow F in FIG.
A directional force will be applied. Here, if the extension force of the cylinder rod 39a of the cylinder device 39 is set to a force smaller than the rotation force about the hinge pin 23 of the first link arm 24,
Cylinder rod 3 of balance cylinder device 39
9a expands and contracts according to the moving direction of the first link arm 24.

Figure 3 shows the balance cylinder device 39 of the present invention.
Shows the air pressure circuit connected to. The piston side chamber of the balance cylinder device 39 is connected to an air source 43, and between them, an original position circuit 44, an arc section circuit 45 which is a rotational auxiliary force biasing circuit, and a counter-progressive force biasing circuit are connected. A certain straight line circuit 46 is connected in parallel. The original position circuit 44 includes a pressure reducing valve (set pressure 1.3 kg/cm ² ) 47, a safety valve 48, and a solenoid valve 4.
9 are connected in series. The arc portion circuit 45 is formed by connecting a pressure reducing valve (set pressure 3.5 kg/cm ² ) 50, a safety valve 51, and a solenoid valve 52 in series. The straight section circuit 46 is formed by connecting a pressure reducing valve (set pressure 1.3 kg/cm ² ) 53, a safety valve 54, and a solenoid valve 55 in series. 56 is a silencer.

The operation of the welding object guiding device configured as described above will be explained. It is assumed that the seam welding machine is set to the state before welding starts. That is,
In FIG. 2, the seam welding machine has a welded object W,
The tracing plate 30 in the longitudinal direction of the weld line of W' engages with the ratchet 17 provided on the guide rail 14, and the half-moon cam pin 28 leading in the longitudinal direction of the weld line of the workpieces W, W' engages with the original. The balance cylinder device 39 passes through the position ratchet 18 and comes into contact with the original position ratchet 18, and as shown in FIG.
It is assumed that both are set to off.

Therefore, first, the objects to be welded W, W' are placed on the cradle 31.
The objects to be welded W and W' are clamped by the clamp member 35 by operation of the clamp cylinder 36. Next, the upper electrode 12 is lowered and the upper electrode 12 and the lower electrode 13 connect the workpiece W,
Hold the straight part of the weld line W′.

After the straight parts of the workpieces W and W' are sandwiched between the upper electrode 12 and the lower electrode 13, the lower electrode 13
Welding is performed while rotating and applying pressure and electricity.
At this time, at the same time that welding starts, the solenoid valve 49 is turned off and the solenoid valve 55 is turned on. Air (pressure) from air source 43
5.0Kg/cm ² ) is reduced by pressure reducing valve 53 (pressure 1.3
kg/cm ² ) and supplied to the piston side chamber of the balance cylinder device 39. Then, the cylinder rod 39a of the cylinder device 39 extends, and the first link arm 24 and the second link arm 26
A small force is applied to the rotary table 27 in the direction F in FIG. 2 through the rotary table 27.

As a result, a small force is applied to the straight parts of the weld lines of the objects W and W' in the direction F in FIG.
Since it is supported and guided by the ratchet 17 and the copying plate 30, even if there is some wobbling in the engagement between the guide rail 14 and the rotary table 27, the weld line of the workpieces W and W' will be maintained. The straight portion is immediately guided in the direction D in FIG. Moreover, even when the weld is melted by the upper electrode 12 and the lower electrode 13, the weld progresses in the direction D' in Fig. 2 without slipping, so welding defects can be prevented and a good welding result can be obtained. .

When the welding of the straight parts of the objects to be welded W, W' progresses and welding of the straight parts is completed, next, the objects to be welded W, W' are welded.
The arc portion of W′ is welded. When the welding transitions from a straight section to an arcuate section, the solenoid valve 55 is switched off and the solenoid valve 52 is switched on. Air from air source 43 (pressure 5.0Kg/cm ² )
is reduced in pressure (pressure: 3.5 kg/cm ² ) by the pressure reducing valve 50 and supplied to the piston side chamber of the balance cylinder device 39. Then, a force larger than the above-mentioned force and smaller than the moving force of the rotary table 27 is applied to the rotary table 27 via the first link arm 24 and the second link arm 26.

As a result, when the objects to be welded W, W' rotate along the welding line of the circular arc part, the rotational force of the objects W, W' is assisted by a large force acting in the direction F in FIG. Therefore, good welding results can be obtained even on the arcuate portions of the objects W, W' to be welded.

In this way, when the welding of the straight and arcuate parts of the workpieces W, W' progresses one after another and approaches the end, the preceding half-moon cam pin 28 of the straight part pushes down the original position ratchet 18 and passes. , all welding ends at a point that slightly overlaps the welding start point.

At this time, the solenoid valve 52 is switched off,
Also, the solenoid valve 49 is turned on. When all welding is completed, the lower electrode 13 stops rotating and the upper electrode 12 returns to its original position. When the upper electrode 12 returns to the upward position, the objects to be welded W,
W' is moved back in the D' direction by the force in the F direction in FIG. 2, and the preceding half-moon cam pin 28 comes into contact with the original position ratchet 18, completing one welding cycle.

In the above embodiment, the solenoid valve 49 for the original position and the solenoid valve 55 for the straight part were arranged separately, but by combining the functions of the two solenoid valves 49 and 55 with one solenoid valve, it is possible to The position circuit 44 may be omitted to allow appropriate control, thereby simplifying the air pressure circuit.

(Effect of the invention) As explained above, according to the invention, when welding the arc portion of the weld line of the workpiece, the rotational force of the rotary table is assisted with a force smaller than the moving force of the rotary table, In addition, when welding a straight part, the rotary table can be biased in the direction opposite to the traveling direction of the workpiece with a force even smaller than the rotational auxiliary force, so that the straight part of the workpiece can be welded. When,
It reliably prevents the welding part from melting and causing the welded object to slip in the opposite direction to the welding direction, and even if there is some wobbling between the guide rail and the rotary table, it will continue along the welding line without meandering. This method has the effect that the workpiece to be welded can be guided immediately, preventing welding defects from occurring and improving welding quality.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing an embodiment of the present invention;
2 is a schematic plan view of FIG. 1, FIG. 3 is a pressure circuit diagram of the balance cylinder device shown in FIG. 2, and FIG. 4 is a pressure circuit diagram of the conventional balance cylinder device. 9... Seam welding machine main body, 12... Upper electrode, 13
... lower electrode, 14 ... guide rail, 24 ... first link arm, 26 ... second link arm, 27
...Rotary table, 28... Half-moon cam pin, 30... Copying plate, 39... Balance cylinder device, 39a...
Cylinder rod, 45...circular section circuit, 46...straight section circuit.

Claims (1)

[Scope of utility model registration request] A workpiece to be welded is moved along the welding line by a guide rail attached to the seam welding machine body and a rotary table that engages with the guide rail and is movably and rotatably supported by the seam welding machine body in a horizontal plane. In the welding object guidance device for a seam welding machine, the workpiece is held between an upper electrode and a lower electrode, and welding is performed while applying pressure and electricity by rotating both electrodes. A balance cylinder device is provided between the seam welding machine main body and the rotary table, and the balance cylinder device is provided with a rotational assisting force that generates a force smaller than the moving force of the rotary table in the rotational direction of the rotary table. A biasing circuit is switchably connected to a force biasing circuit in a counter-progressing direction that generates a force smaller than the force generated by the rotational auxiliary force biasing circuit in a direction opposite to the traveling direction of the workpiece. A workpiece guidance device for seam welding machines.