JPH0771747B2 - Automatic welding method and device for small parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention inserts a small part projecting a projection on a welding surface such as a welding bolt or a T-shaped welding nut into a narrow portion of a press work. And a welding device for performing welding by supplying current to the upper and lower electrodes by applying pressure and welding, and using such an intermediate electrode that can be inserted between the upper and lower electrodes for supplying parts and welding to such a narrow space .

(Prior Art) Conventionally, when a welding bolt is supplied to a deep bottom plate or a narrow portion such as a container and is welded through upper and lower electrodes, for example, as disclosed in Japanese Utility Model Laid-Open No. 63-106590. Parts feeders have been proposed.

That is, this type of device is a component feeding means that feeds a welding bolt from a predetermined position, and a chuck device that holds a component directly under the component feeding means and that moves the chuck to a welding position and feeds it. In the component supply device having the above, the chuck device is supported by a chuck feed mechanism that is movable in the horizontal direction and the vertical direction.

With this device, even if the bottom plate in a deep place can be supplied by simply lowering the chuck device vertically from the top of the work and opening the chuck, it is possible to accurately weld the welding bolt without being restricted by the depth or length of the work. It has the advantage that

(Problems to be Solved by the Invention) However, as shown in FIG. 5, when the welding bolt B is supplied to the deep bottom plate f for welding, the gap e of the narrow portion h of the workpiece w is narrow, Since the chucking device cannot open the chuck in the narrow portion, the use of the narrow portion is restricted in a place where the space is narrow.

(Means for Solving the Problem) Therefore, the present invention takes the following technical means as means for solving the above problems.

That is, the present invention is a method of supplying a small part such as a welding bolt or a welding nut to a narrow portion of an object to be welded, and pressing the same through a pair of an upper electrode and a lower electrode. The small parts sent to a position close to the above are adsorbed and held by an intermediate electrode that can be inserted into the narrow portion, the intermediate electrode is shifted, and the small parts are transferred onto the pressure center line of the upper and lower electrodes, and then the above-mentioned We provide an automatic welding method for small parts that lowers small parts together with an intermediate electrode into the narrow space, inserts them with the intermediate electrode, and supplies welding force and welding current required between the upper and lower electrodes for welding. To do.

Next, as an invention for carrying out the method of the above-mentioned invention, a small-part feed for feeding a small part such as a welding bolt or a welding nut to a position close to a pair of upper and lower electrodes of a resistance welding machine. Feeding device, member for receiving small parts sent from the feeding device, small parts shifting device for shifting this member to a predetermined position, intermediate electrode for sucking and holding the small parts at a predetermined position, and intermediate electrode And an intermediate electrode shift device that shifts the suction-held small component toward the electrode pressing center line of the welding machine, and an automatic welding device for a small component. .

(Operation) According to the method and apparatus of the present invention, small parts can be accurately supplied by using the intermediate electrode even in a narrow space having an extremely narrow width. And can be done in the same motion.

In addition, since the resistance welding machine is simply added with units such as the intermediate electrode, the suction means, and the shift device, the structure is relatively simple and can be manufactured at low cost.

(Example) Hereinafter, the most preferable example of an apparatus for carrying out the method of the present invention will be described with reference to the drawings.

FIG. 1 is a front view of the device of the present invention. FIG. 2 is a side view of the same. Further, FIG. 3 is a plan view. And FIG. 4 is a cross-sectional view of an essential part of the intermediate electrode.

Reference numeral 1 indicates an upper electrode of the spot welding machine. Reference numeral 2 is a lower electrode corresponding to the upper electrode 1 on the center line (A-A) of pressure. Reference numeral 3 is an intermediate electrode, and its specific structure is, as shown in FIG. 4, connected to the tip of the intermediate electrode holder 4 and the reciprocating paths of the cooling water passages 4b and 4c provided in the intermediate electrode holder 4. And the upper electrode chip 5 corresponding to the upper electrode 1 is provided in the upper chip insertion hole a.
However, the lower electrode tip 6 corresponding to the lower electrode 2 is inserted into the lower tip insertion hole b on the same axis line, and these upper and lower electrode tips 5 and 6 are provided in the cooling water passage 4b of the intermediate electrode holder 4, It will be cooled by the cooling water that circulates in the 4c reciprocating path. The diameter of the lower electrode tip 6 is substantially the same as the diameter of the head of the welding bolt B, and the air suction port 6a is provided at the center thereof.
Is provided. This air suction port 6a is used for the intermediate electrode holder 4
It communicates with the vacuum air passage 4a provided inside. Therefore, when the suction port of the lower electrode tip 6 is closed by the head of the bolt B, the suction force by the vacuum acts on the space of the suction port by the air suction, and the welding bolt is suction-held on the lower electrode tip pressing surface. In addition, 7 is a lower arm of the welding machine main body which supports the lower electrode 2,
Is a support table, which has a welded structure integrated with a bracket 8'fixed to the lower arm 7.

The intermediate electrode shift device 10 has the following structural parts.
That is, a rail supported horizontally on the support base 8.
11, a housing 13 that moves along the rail 11 when the cylinder 12 is driven, and a moving base 14 that is fixed to the housing 13.
A bracket 15 fixed vertically to the rail 16, a rail 16 supported by the bracket 15, an L-shaped bracket 17 fixed to a side surface of the rail 16, and a lifting cylinder 18 fixed downward on the bracket 17. And a housing that moves along the rail 16 by driving the lifting cylinder 18.
It is composed of 19 and.

Therefore, the intermediate electrode holder 4 is supported by the housing 19 so that the intermediate electrode holder 4 can move forward in the direction perpendicular to the electrode pressurizing line and can be moved up and down.

The small-part shifting device 20 has the following structural parts. That is, the angle bracket fixed on the support base 8
The rail 21 is fixed to the rail 21 in a direction intersecting with the forward movement direction of the intermediate electrode shift device 10.
The hanging 22 moves above, and a bolt receiving member 25 is fixed to the tip of an L-shaped bracket 24 fixed to the hanging 22. And this bracket
24 and the piston rod of the cylinder 23 are connected via a knuckle 26 for shifting. Therefore, the bolt that has passed through the bolt supply pipe 27 and dropped from the hose outlet, which is not shown in the drawing, is supplied to the bolt receiving member 25 directly below the bolt receiving member 25, and the intermediate electrode 3 together with the member 25 is advanced by the advance of the cylinder 23. The mechanism is such that it is supplied directly below the lower electrode chip 6.

Next, the operation of the device of the present invention will be described.

The cylinder 12 and the elevating cylinder 18 of the intermediate electrode shift device 10 are retracted, and the intermediate electrode 3 stands by at the elevated position. The cylinder 23 of one of the small component shift devices 20 is also waiting at the return position. In this case, the welding bolts are selected by a bolt supply device (not shown) in advance and are supplied to the small component receiving member 25, which stands by immediately below the hose outlet, through the bolt supply pipe 27. In this state, the press work is set on the lower electrode. In this case, the rocket pin of the lower electrode 2 is inserted and set in the positioning hole at the welding position of the press work.

After setting is complete, press the start button to receive the component receiving member.
The welding bolt B supplied to the 25 is a small component shifting device 20.
The cylinder 23 advances and is supplied just below the lower electrode tip 6 of the intermediate electrode 3 on standby. When the welding bolt B comes directly under the lower electrode tip 6 of the intermediate electrode, the cylinder of the intermediate electrode
When 18 lowers the intermediate electrode holder 4, vacuum starts at the same time, and when the lower electrode tip 6 holds the head of the bolt and closes the air suction port 6a, the space is sucked and the welding bolt is sucked by the suction force of the vacuum. The intermediate electrode having the welding bolts attracted to the lower electrode tip 6 is lifted up to a predetermined position by the lifting cylinder 18. And the cylinder 12 of the intermediate electrode shift device 10.
Then, this is moved forward, and the welding bolt is transferred onto the center line (A-A) of pressure applied to the upper and lower electrodes. When the welding bolt enters the center line of pressure, the upper electrode 1 is lowered by the welding start command signal from the welding control device and pushes up the intermediate electrode holder 4 from above, and at the same time, the intermediate electrode is also assisted by the lifting cylinder 18. Driven and descends. When the intermediate electrode 3 descends into the narrow portion and the threaded portion of the welding bolt B pushes up the pilot pin of the lower electrode 2 and is supplied to the positioning hole of the workpiece, the intermediate electrode 3 causes the head of the bolt to bottom plate in the narrow portion. Will be pressurized on.

Then, the vacuum is stopped, and the welding force and welding current required for welding are supplied between the upper and lower electrodes via the intermediate electrode to perform bolt welding.

Regardless of its operation, the small component shifting device 20 returns to its original position during this welding period to prepare for the next bolt supply.

When the welding is completed, the upper electrode 1 and the intermediate electrode 3 ascend, the welded material is released, and at the same time, the intermediate electrode returns to the original position from the pressurizing center line and waits for the next operation.

The subsequent series of operations automatically repeats these mechanical and electrical operations.

(Effects of the Invention) As described above, according to the present invention, it is possible to accurately supply even a narrow space having an extremely narrow width in a state where the intermediate electrode holds the small component by suction, and moreover, the pressure welding is immediately started by the supply operation. Therefore, reliable welding can be performed at the same time when the parts are supplied.

Further, since only the suction means and the shift device are provided on the intermediate electrode, the feeding unit device has a relatively simple structure and can be manufactured at low cost.

In the embodiment of the present invention, the air vacuum method is used as the suction means for the intermediate electrode, but the technical idea of the present invention is not limited to this, and for example, an electromagnet or a permanent magnet may be used. However, it goes without saying that it is included in the technical category of the adsorption means in the present invention.

[Brief description of drawings]

FIG. 1 is a front view showing the most preferred embodiment as an apparatus for carrying out the method of the present invention. Fig. 2 is Fig. 1 II-
II arrow view. FIG. 3 is a plan view. FIG. 4 is an enlarged cross-sectional view of the main part of the intermediate electrode. FIG. 5 is a perspective view including a crushed cross section showing a structure of an object to be welded. [Explanation of symbols] 1, 2 ... upper and lower electrodes, 3 ... intermediate electrode, 4 ...
Intermediate electrode holder, 10 ... Intermediate electrode shifter, 20 ... Small parts shifter

Claims (2)

[Claims] 1. A method of supplying a small part such as a welding bolt or a welding nut to a narrow part of an object to be welded and pressure welding the same through a pair of an upper electrode and a lower electrode. Small parts sent to close positions are adsorbed and held by an intermediate electrode that can be inserted into the narrow part, and the intermediate electrode is shifted to transfer the small parts to the pressure center line of the upper and lower electrodes, and then the middle part. An automatic welding method for small parts, in which a small part is dropped together with an electrode into the narrow space and is inserted by the intermediate electrode, and then a pressure and welding current required for welding are supplied between the upper and lower electrodes to perform welding. 2. A small parts feeding device for feeding small parts such as a welding bolt or a welding nut to a position close to a pair of upper and lower electrodes of a resistance welding machine, and a small parts feeding device for feeding the small parts. A member for receiving small parts, a small part shifting device for shifting the member to a predetermined position, an intermediate electrode for adsorbing and holding the small part at a predetermined position, and supporting and supporting the intermediate electrode so that it can be moved up and down. An automatic welding device for small parts, comprising: an intermediate electrode shift device that shifts the small parts toward the electrode pressing center line of the welding machine.