JPS6049874A - Spot welding device with approach device - Google Patents

Abstract

PURPOSE:To simplify the entire part of a device and to suppress equipment cost by making common use of an actuator for approach and nonapproach action and the opening and closing action of the gun itself. CONSTITUTION:When a piston rod is advanced by actuating an air cylinder 24, a coil spring 46 is interposed between a crevice 39 and a hinge pin 40 and therefore the entire part of a holder 34 ascends and makes approach action without moving a gun arm 41a. The holder 34 contacts thereafter with a nut 36 but the piston rod continues to advance further and the clevice 39 and the holder 34 move relatively from the point of the time when the holder 34 contacts with the nut 36. Then the arm 41a performs closing action to grasp a panel work W with pressure. The spot welding is executed in this state. When the welding is completed, the cylinder 24 is actuated backward and the arm 41 performs opening action. The holder 34 performs unapproach action and stops in the lower limit position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spot M contact device with an approach device.

For example, as a spot welding apparatus with an approach device used in the assembly process of an automatic I, a structure shown in FIG. 1 is known. This example shows a spot welding device for welding the side sill W, which is a component of the body side, as a panel work. 1 is an X-shaped spot welding gun, and this spot welding gun 1 is used to weld a single layer gun arm. 2
a, '2 b and small gun arm 2a, 2b%i
It is composed of an air cylinder 3 as an actuator for opening and closing operations, and a bracket 4. Is 6 the spot welding gun 1 above? Supporting approach equipment @
50 lifter plate, this lifter plate 6 is
By actuating an actuator provided on the base 7, for example, a near cylinder 80, it moves up and down guided by guide bars 9, 9.

That is, the spot welding gun 1 rises together with the lifter plate 6 due to the operation of the air cylinder 8, and the spot welding gun 1 reaches the predetermined approach limit position? When the limit switch is detected, the control device 11 receives a signal via 13 codes and sends a signal to the valve 12 via 14 codes, thereby operating the air cylinder 3.

Due to this, the gun arms 2a and 2b are side sill W? Pressurization.

It is clamped and spot welded.

When spot welding is easy to perform, several of the above devices are installed in parallel and operated simultaneously.

However, in the conventional spot welding equipment as described above, the actuator for approach operation and the actuator for opening/closing the gun are separate and independent, so their drive control circuits are controlled by oil and pneumatic pressure. It is necessary to establish a system. Also, is the welding gun waiting for a signal that the approach operation is complete? A control method of applying pressure had to be adopted, which required the installation of an electrical timing control circuit centered around the limit switch 7 mentioned above, and there was also the problem of relatively long takt time. .

In particular, the drive control circuit and timing control circuit using oil/pneumatic pressure mentioned above? The complexity of the equipment required to be installed and the soaring cost of equipment become more pronounced as the number of welding equipment increases.
The purpose of this invention is to solve the above problems by sharing one actuator for the approach and unapproach operations of the spot welding gun and for the opening and closing operations of the gun itself.

That is, in the present invention, the above purpose? In order to achieve
Only one actuator is used, and the spot welding gun is approached to a predetermined approach limit position with the gun arm in the open state by moving the actuator's operating rod forward, and then the actuator's operating rod continues to operate. By continuing, the drawing rod and the gun arm are brought closer together and the gun arm closes, which is the seventh special feature.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings.

FIGS. 2 to 4 are diagrams showing an embodiment of the present invention.

The spot welding apparatus shown in the figure is roughly divided into an X-shaped spot welding gun 2o and a floating base unit 21 that supports this spot welding gun 20.

22 Its At the base unit 210, a trunnion type air cylinder 24 as an actuator is rotatably supported on a bracket 23 on the base 22. A horizontal holder tab V-125 is integrally provided on the upper end surface of the air cylinder 24.

Here, the air cylinder 24 is used for approach and unapproach operations of the spot welding gun 20, as will be described later.
It is commonly used for both opening and closing operations of the spot welding gun 20 itself.

Further, on the base 22, two guide rods 27 each having a coil spring 26 fitted thereon are rotatably erected by separate brackets 28 and hinge pins 29'fX'. On the other hand, a movable piece 32 is rotatably attached to the upper part of the guide rod 27 through a bracket 3o and a hinge pin 31fX'9 provided on the lower surface of the holder plate 25. The pieces 32 serve as seats for the coil springs 26 and are individually slidably inserted into the guide rod 27.

That is, the guide rod 27, the bracket 28, the bracket 30, and the movable piece 32 can rotate relative to each other in the direction 1'L, and the guide rod 27 and the movable piece 32 can also move relative to each other. In the normal state, the holder plate 25 is elastically supported horizontally by the force of two coil springs 26. The structure is such that the holder plate 25 can float around the rotating shaft 33 of the air cylinder 240 only when an excessive external force is applied.

34 is arranged above the holder plate 25, and the spot welding gun 20? This holder 34 is directly supported in the shape of an abbreviated character, and this holder 34 moves up and down along the guide bars 35 as two guide members installed upright on the holder plate 25, that is, approach and unloading. Seven approach movements are performed. And guide bar 3
5 has a nut 36 as a stopper that determines the upper limit position of the holder 34, that is, the approach limit position.
It is attached to the top and protects it.

37 is driven by the air cylinder 24 as an operating rod.
This piston rod 37 passes through 25 holder plates and connects to the bush 3 in the center of the holder 34.
8, and a clevis 39 is integrally connected to the tip thereof.

40 is a hinge pin horizontally suspended on the holder 34;
It is fixed to the holder 34 by pins 40d at both ends and a C-shaped retaining ring 4°CK. Also, this hinge pin 40K
A pair of gun arms 41a of ld spot @ contact gun 2o,
4] h is boulder - 34 to 0) fVJVC color 40
e Gun arm 41a via Y.

Hinge 40d, 401'1 provided on the eaves 1 of 41+)
It is rotatably supported by a shaft. A hinge pin 4 is provided at the lower end of each gun arm 41a, 41b.
A pair of 11 links 43 and 44 are connected via 2fX, and the other ends of these links 43 and 44 are connected to the above-mentioned V screw 39 through hinge pins 45.

When replacing, the +1 link 43° 44 and the clevis 39 form a toggle mechanism, and between the clevis 39 and the hinge pin 40 there are gun arms 41a, 4.
1ft'? A coil spring 46 serving as an elastic body that biases each other in the opening direction is installed in the valve housing, and the pair of gun arms 41a and 41b are opened and closed mutually by the lifting and lowering movement of the clevis 39.

Here, the operation of the spot welding apparatus configured as described above will be explained.

First, Fig. 2 and Fig. 4 show the holder 34 at the upper limit position, that is, the approach limit position, and the gun arms 41a, 41b #'' are closed and pressurized. 34 is at the lower limit position, the lower gun arms 41a41b are open to each other.

Then, when the halter 34 is at the lower limit position 9, when the 24 air cylinders are actuated to move the piston rod 37 forward, a coil spring 46 is inserted between the clevis 39 at the tip of the piston rod 37 and the hinge pin 400. Therefore, until the boulder 34 hits the nut 36, the clevis 39 and the holder 34 do not move relative to each other due to the repulsive force of the coil spring 46, and therefore the gun arm 41a.

41b does not move at all, and the entire holder 34 rises to perform an approach operation.

After that, when the holder 34 hits the nut 36, the holder 34 hits the nut 36! Although the vl cylinder stops, the piston rod 37 of the air cylinder 24 continues to move forward. Then, the clevis 39 resists the fill spring 46 for the first time from the time when the holder 34 and the nut 36 contact each other.
and the holder 34 begin to move relative to each other, and the piston rod 3
7 and the gun arms 41a, 41b approach, and the II ink 4
3 and 44, the gun arms 41a and 41b mutually close and close the panel work W'? Pressure and clamp. At this time,
If the relative positioning accuracy between the panel work W and the spot @ contact gun 20 is insufficient (if a position occurs, the entire holder plate 25 described above will float and absorb the amount of f). So, panel work W
Be careful not to damage it. Then, spot welding is performed under the above-mentioned pressurized state.

On the other hand, when spot welding is completed, the air cylinder 24 operates in reverse, and the gun arms 41a, 41 or the coil spring 46
At the same time, the holder 34 performs an unapproaching operation due to the action of the air cylinder 24 and stops at the lower limit position.

According to the above embodiment, the spot welding gun 20
The approach and unapproach operations of the gun and the opening and closing operations of the gun itself are carried out in conjunction by a single shared air cylinder 24.

Furthermore, if it becomes necessary to change the approach stroke based on changes in the rainbow of the panel work W, etc., this can be easily handled by simply adjusting the position of the nut 36 serving as a stopper. In the embodiment of the present invention, the air cylinder 11'fX-'IE is used as the actuator 24, but the same effect can be obtained by providing a rack on the operating rod and driving it with a binion rotated by this rank chemical motor. .

As is clear from the above description, according to the present invention, one actunie spot welding gun is substantially used for approach and unapproach operations and for opening and closing operations of the gun itself. In addition, it is possible to use a hydraulic and pneumatic drive control circuit system, which previously required two systems, and the timing control circuit, which was previously considered indispensable, can be eliminated, simplifying the entire device and reducing equipment costs. can contribute to suppression.

Also, by eliminating the need for a timing control circuit,
Takt time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram schematically showing a conventional spot welding device with an approach device, FIG. 2 is an explanatory diagram showing an embodiment of the spot welding device with an approach device according to the present invention, and FIG. nl-1! FIG. 4 is a sectional view taken along line IV-IV in FIG. 2. 24°°° air cylinder (actuator), 34...
・Holder, 35... Guide bar (guide member), 3
6... Nut (stopper), 37... Pinton rod (made m rod), 39... Clevis, 40...
Hinge bin, 40a, 40b...Hinge, 4oυ...
Axial C-type retaining ring, 40d/°/bin, 40e...collar, 41a, 41b...gun arm, 43, 44-
Link, 46...Coil spring (elastic body).

Claims (1)

[Scope of Claims] (11) A holder (34) that is provided so as to be able to approach and unapproach the panel work W along the guide member (35), and a holder (34) that is pivotally supported to be openable and closable. a pair of gun arms (41, 4]b), an actuation rod (37) that is movable relative to the holder (34), and a pair of gun arms (4xa, 4xb) that are connected to the actuation rod (37); When the VcL gun arms (4+a, 41b) approach the gun arms (4+a, 41b), one end is connected to the end of the gun arm (41a, s]b) separately, and the other end is connected to the end of the operating rod (4+a, 41b). 37), an elastic body (46) that always urges the gun to frame (4+a, 5tb) in the open direction, and an approach limiter for the holder (34). The stopper (36) to be set and the operating rod (37)'%' holder (34) are moved forward until they reach the approach limit and further approach the gun A (41a, 41b), and the holder (34) is moved to the unapproach position. and an actuator (24) that causes it to retreat until
/ A spot welding device with an approach device.