JPH0763859B2 - Automatic welding equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an automatic welding apparatus for automatically projection welding a welded object such as a bolt or a nut to a predetermined position of a work.

[Prior Art] Conventionally, when welding, for example, a nut at a predetermined position of a work, an operator places the nut mounting portion of the work on a lower electrode fixed to the main body of the welding machine and puts the nut on the nut mounting portion. The nut was welded to the nut mounting portion between the lower electrode, which was placed on the lower electrode and the lower electrode.

[Problems to be Solved by the Invention] Therefore, since the welding work becomes a complicated manual work, there is a problem that the work efficiency is lowered. Further, in automating the welding work, a welded object such as a bolt or a nut is properly handled. It is extremely difficult to position accurately to weld at a certain position, which causes the displacement of the welding position, and a cleaning process is required to remove stains and welding debris adhering to the welded material, workpiece, and welding site. There was a problem.

The present invention aims to solve the above problems.

[Means for Solving the Problems] In the automatic welding apparatus of the present invention, the finger plate, which is controlled to move in the front-back direction and the left-right direction, has a main body of a welding machine below an upper electrode movably attached to the main body of the welding machine. An appropriate number of lower movable electrodes, which are controlled to be transferred directly above the lower fixed electrodes fixedly attached to the lower fixed electrodes and are brought into contact with the lower fixed electrodes during welding, are attached so that they can be elastically displaced in the vertical direction. Is provided with positioning means for positioning the welded object to be welded to the work placed on each of the lower movable electrodes and restraining the welded object mounting portion of the work, and at the center of the lower fixed electrode. The lower movable electrode has a configuration in which an injection hole for ejecting air toward the hole formed in the central portion of the lower movable electrode is formed in a longitudinal shape.

[Operation] Lower fixed electrode with the lower electrode of the welding electrode fixed to the main body of the welding machine, and the lower fixed electrode that is elastically displaceable in the vertical direction on the finger plate that is controlled to move in the front-back and left-right directions. Divide into an appropriate number of lower movable electrodes that come in and out of
The lower movable electrode is transferred together with the work piece attachment portion of the workpiece to a position directly above the lower fixed electrode, and the lower movable electrode pressed by the lower moved electrode is brought into contact with the lower fixed electrode to move the lower movable electrode. The electrode is energized to weld the welded product positioned by the positioning means to the welded product mounting portion of the work between the upper electrode and the lower movable electrode to the weldable product mounting portion.

In addition, dirt and welding debris adhering to the bolts, nuts, and workpieces are blown out and removed by the air that has ejected from the injection hole of the lower fixed electrode and has passed through the hole of the lower movable electrode, and is also removed. Electrical contact with is cleaned and cooled.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it is possible to accurately position the weldments during welding and hold them on the weldment attachment portion of the workpiece, and place the respective weldments in proper positions. Since the displacement of the welding position can be eliminated by welding and each lower movable electrode is elastically displaced downward at the time of welding, there is an effect that an error in the supply position of the welded material in the vertical direction can be absorbed.

Moreover, since the lower movable electrode contacts the lower fixed electrode only during welding, wear of the lower movable electrode can be suppressed and durability of the lower electrode can be improved.

Furthermore, since the work piece can be set on the appropriate number of lower movable electrodes and the work piece attachment part of the work piece can be positioned, the work piece size and shape can be absorbed and the work piece can be welded to the proper position. In addition, because the injection hole is formed in the lower fixed electrode, dirt adhering to the welded product or the welded product attachment part of the workpiece and welding debris adhering to the welding site are automatically removed by the air ejected from the injection hole. At the same time, the air ejected from the injection hole can be blown to the welded object, the welded object attachment part of the work, the welded part, and the electrical contact part between the lower fixed electrode and the lower movable electrode. It is possible to effectively clean and cool the welded material attachment part of the workpiece and the vicinity of the welded part before and after welding, and also to clean and cool the electrical contact part between the lower fixed electrode and the lower movable electrode.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

The automatic solution machine is for the projection welding of the nut N to each of the nut mounting portions W2 of the workpiece W and the bolt welding machine main body 1A installed to perform the projection welding of the bolts V to each bolt mounting portion W1 of the workpiece W. Nut welder body installed on the side of bolt welder body 1A
1B and the bolt mounting part W1 of the workpiece W to the bolt welder body
In order to sequentially transfer each nut mounting portion W2 of the work W to the electrode position of the nut welding machine body 1B after sequentially transferring to the electrode position of 1A, based on a program set in advance corresponding to the specifications of the work W. The transfer robot 2 is driven and controlled.

A lower arm 3 and an upper arm 4 projecting forward are formed in parallel at a central portion and an upper end portion of the bolt welder main body 1A, and a lower holder 6 attached to a front end of the lower arm 3 is fixed to the lower holder 6 downwardly. Electrode 5A is installed vertically, and this lower fixed electrode 5A
An injection hole 5aA, which is connected to a blower (not shown) for ejecting air above the lower fixed electrode 5A, is vertically formed in the central portion of the. A cylinder 7 attached to the front end of each upper arm 2.
An upper holder 9 is attached to the piston rod 7a of the above, and an upper electrode 8A arranged coaxially above the lower fixed electrode 5A and vertically driven at a fixed position by a cylinder 7 is vertically mounted on the upper holder 9. Is attached to.

A lower arm 3 and an upper arm 4 projecting forward are formed in parallel at the central portion and the upper end portion of the nut welder main body 1B, respectively, and fixed downward to a lower holder 6 attached to the front end of the lower arm 3. Electrode 5B is installed vertically, and this lower fixed electrode 5B
An injection hole 5aB, which is connected to a blower (not shown) for ejecting air above the lower fixed electrode 5B, is vertically formed in the central portion of the. A cylinder 7 attached to the front end of each upper arm 2.
An upper holder 9 is attached to the piston rod 7a of the above, and an upper electrode 8B coaxially arranged above the lower fixed electrode 5B and vertically driven at a fixed position by a cylinder 7 is vertically mounted on the upper holder 9. Is attached to.

In the transfer robot 2, a horizontal feed rail is installed on a horizontal guide rail 11 installed horizontally on the base 10 along the left-right direction.
12 is placed so that it can move horizontally to the left and right,
Vertical guide rails installed orthogonally on this horizontal feed table 12
A vertical feed table 14 is installed on the upper surface of the vertical feed table 14 so that it can be moved horizontally in the front-rear direction. A finger plate 15 for transfer between and is horizontally attached.

On the finger plate 15, each bolt mounting part W1 of the work W
Bolt welder body to weld each bolt V to
An appropriate number of lower movable electrodes for welding bolts 17A that are transferred and controlled to a position directly above the lower fixed electrode 5A of 1A, and a nut welding machine main body 1B for welding the nuts N to the nut mounting portions W2 of the work W, respectively. An appropriate number of nut-moving lower movable electrodes 17B that are transfer-controlled to a position directly above the lower fixed electrode 5B are attached. A positioning hole is formed through each bolt mounting portion W1 and each nut mounting portion W2 of the work W, and the positioning hole of each bolt mounting portion W1 of the work W is located at the center of the lower movable electrode 17A for each bolt welding. The positioning holes of the nut mounting portions W facing each other have the lower movable electrodes 17 for welding the respective nuts.
An operator places the movable electrodes 17A and 17B on the movable electrodes 17A and 17B so as to face the center of B. A bolt V is supplied to each bolt mounting portion W1 of the work W by a parts feeder (not shown), and a nut N is supplied to each nut mounting portion W2 of the work W by a parts feeder.

Finger plate 1 near the lower end of each lower movable electrode 17A, 17B
The lower movable electrodes 17A and 17B are respectively inserted into the hole portions 15a penetrating the hole 5, and the engaging grooves 18 are formed in a ring shape in the lower portion of the lower movable electrodes 17A and 17B along the circumferential direction. A pair of spacers 19, 19 are placed on both sides of each lower movable electrode 17A, 17B of the finger plate 15, and
The pair of spacers 19 are mounted on the pair of spacers 19 so as to face each other, the inner edges 20a thereof are curved in an arc shape, and the pair of support members 20 each formed of a leaf spring material are fastened by bolts 21. There is. The inner end edges 20a of the supporting members 20 of each pair are fitted in the respective locking grooves 18 of the lower movable electrodes 17A and 17B, and the lower movable electrodes 17A and 17B are supported by the supporting members 20 of each pair. It is supported so as to be elastically displaceable in the vertical direction.

In the center of the lower movable electrode 17A for bolt welding, a positioning hole 22 is bored in the upper part for inserting the threaded portion V1 of the bolt V, and a positioning hole 22 is continuously formed below the positioning hole 22 for allowing air to flow. The through holes 23 are formed in a longitudinal shape. The threaded portion V1 of each bolt V penetrates the positioning hole of the workpiece W and is inserted into the positioning hole 22 of the lower movable electrode 17A, and the bolt head V2 is placed on the bolt mounting portion W1 of the workpiece W. The lower movable electrode 17A is positioned in this state and is restrained at the upper end of each lower movable electrode 17A.

Each lower movable electrode 17A for bolt welding is the bolt welding machine body 1A
When selectively moved between the lower fixed electrode 5A and the upper electrode 8A, the distance between the lower movable electrode 17A and the lower fixed electrode 5A is about 0.5 mm.
Gaps K are formed in the lower fixed electrode 17A while the lower movable electrode 17A is slightly separated from the lower fixed electrode 5A.
Move directly above. In this state, the upper electrode 8A moves downward and presses against the bolt head V2 of the bolt V, and the lower movable electrode 17A moves to the support member 2
It is pushed down against the elastic force of 0 to come into contact with the lower fixed electrode 5A, and the lower movable electrode 17A is energized, and the upper electrode 8A and the lower movable electrode 1 are energized.
The bolt head V2 of the bolt V is projection welded to the bolt mounting portion W1 of the work W between the bolt 7 and 7A. Upper electrode after welding
8A moves upward, the lower movable electrode 17A returns to the original position by the elastic force of the support member 20 and separates from the lower fixed electrode 5A, and the above operation is repeated so that each bolt V is sequentially attached to each bolt mounting portion W1. Welded.

Further, when each lower movable electrode 17A moves directly above the lower fixed electrode 5A, the ejection hole 5aA of the lower fixed electrode 5A and the flow hole 23 of the lower movable electrode 17A are communicated with each other, and the air ejected from the ejection hole 5aA is positioned. Spouting upward from inside the hole 22 and screw part of the bolt V
Dirt on the bottom surface of V1 and the bolt head V2 and the bolt mounting portion W1 of the workpiece W is blown away and removed by the jet of air prior to welding, and after welding the welding debris adhered to the thread V1 of the bolt V is welded by the air. It is blown away and removed.

At the center of each lower movable electrode 17B for nut welding, a pin insertion hole 25 is formed at the upper part thereof, a spring insertion hole 26 is continuously formed below the pin insertion hole 25, and below the spring insertion hole 26. And a screw hole 7 that is continuously drilled in a vertical direction.

The positioning pin 28, which is vertically slidably fitted in the pin insertion hole 25, is inserted into the screw hole N1 of the nut N so as to position the nut N and protrudes above the upper surface of the lower movable electrode 17B. The nut fitting portion 28a is formed in a tip shape, and the positioning pin 28 has a lower end portion with a positioning pin.
A flange 28b for protruding the 28 from above is projected. A coil spring 29 is inserted into the spring insertion hole 26, which is screwed into the screw hole 27 and has a hole 30a provided through the screw 30 so as to prevent the coil 30 from coming off and biasing the positioning pin 28 upward. 28 is supported on the upper end of the lower movable electrode 17B so as to be elastically displaceable in the vertical direction. The work W is set on the upper end of each lower movable electrode 17A, 17B with the nut fitting portion 28a of each positioning pin 28 of each lower movable electrode 17B being inserted and positioned in each positioning hole of the nut mounting portion W2. To be done.

Nuts N fed by a parts feeder (not shown)
The nut fitting portion 28a of the positioning pin 28 is inserted into the screw N1 and is positioned while being placed on the nut mounting portion W2 of the work W and is restrained by the upper end of the lower movable electrode 17B.

Each lower movable electrode 17B for nut welding is the nut welding machine body 1B
When moving between the lower fixed electrode 5B and the upper electrode 8B, there is a gap K of about 0.5 mm between the lower movable electrode 17B and the lower fixed electrode 5B.
Are formed respectively, and the lower movable electrode 17B moves to a position directly above the lower fixed electrode 5B in a state of being slightly separated from the lower fixed electrode 5B. In this state, the upper electrode 8B moves downward and presses against the nut N, and the lower movable electrode 17B is pushed down against the elastic force of the support member 20 and abuts on the lower fixed electrode 5B, so that the lower movable electrode 17B contacts the lower movable electrode 17B. The nut N is projection welded to the nut mounting portion W2 of the work W between the upper electrode 8A and the lower movable electrode 17B by being energized. After welding, the upper electrode 8B moves upward, and the lower movable electrode 17B is separated from the lower fixed electrode 5B that has returned to its original position by the elastic force of the support member 20, and the above operation is repeated so that each nut N becomes It is sequentially welded to the nut mounting part W2.

Further, when each lower movable electrode 17B moves directly above the lower fixed electrode 5B, the ejection hole 5aB of the lower fixed electrode 5B and the screw hole 27 of the lower movable electrode 17B are communicated with each other, and the air ejected from the ejection hole 5aB is a screw hole. The air is ejected from the pin insertion hole 25 through the inside of the spring 27, the spring insertion hole 26, and the pin insertion hole 25, and the dirt of the screw hole N1 of the nut N, the lower surface of the nut N, the nut mounting portion W2 of the work W, and the like is ejected as air. Is removed prior to welding, and the welding residue attached to the screw holes N of the nut N after welding is blown away by air and removed.

Next, the operation and effect of the embodiment having the above-mentioned configuration will be described.

In this example, the finger plate 15 that is controlled to move in the front-rear direction and the left-right direction is fixed to the welding machine bodies 1A and 1B below the upper electrodes 8A and 8B that are vertically movable to the welding machine bodies 1A and 1B. Lower fixed electrodes 5A, 5B are transferred and controlled so that they are brought into contact with the lower fixed electrodes 5A, 5B during welding.
7A and 17B are attached so that they can be elastically displaced in the vertical direction, and each lower movable electrode 17A and 17B is attached to each lower movable electrode 1A.
Positioning means for positioning the bolts V and nuts N to be welded to the work placed on 7A and 17B and restraining them to the bolt welding portion W1 and the nut mounting portion W2 of the work W are provided respectively, and the lower fixed electrode 5A is provided. Lower movable electrodes 17A, 1
Injecting holes 5aA and 5aB for ejecting air toward a hole formed in a central portion of 7A in a longitudinal shape are formed in a longitudinal shape.

Therefore, the bolts V and nuts N can be accurately positioned during welding and can be held on the bolt mounting portion W1 and the nut mounting portion W2 of the work W, and each bolt V and each nut N can be welded to proper positions. The displacement of the welding position can be eliminated, and the lower movable electrodes 17A and 17B are elastically displaced downward during welding, so that an error in the supply position of the bolt V and the nut N in the vertical direction can be absorbed.

Further, since the work W can be set on the plurality of lower movable electrodes 17A, 17B to position the bolt mounting portion W1 and the nut mounting portion W2 of the work W, variations in the size and shape of the work W can be absorbed. The bolt V and the nut N can be welded to proper positions.

Also, the lower movable electrodes 17A, 17B are the lower fixed electrodes 5A, 17B only when welding.
Since it abuts against 5B, it is possible to suppress wear of the lower movable electrodes 17A and 17B and improve the durability of the lower electrodes.

Further, in this example, since the air is ejected to the bolt mounting portion W1 and the nut mounting portion W2 of the work W, the vicinity of the welded portion of the work W can be effectively cleaned before and after welding.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a side view of an automatic solution device, FIG. 2 is a plan view of the same, FIG. 3, and FIG.
Each of the figures is a longitudinal sectional view of the main part, and FIG. 5 is XX of FIG.
It is a line sectional view. 1A: Bolt welder body 1B: Nut welder body 5A, 5B: Lower fixed electrode 8A, 8B: Upper electrode 15: Finger plate 17A, 17B: Lower movable electrode

Claims (1)

[Claims] 1. A finger plate that is controlled to move in the front-back direction and the left-right direction is transferred to a position directly below a lower fixed electrode fixed to the main body of the welder below an upper electrode attached to the main body of the welder so as to be vertically movable. A suitable number of lower movable electrodes, which are controlled and contact the lower fixed electrodes during welding, are attached so that they can be elastically displaced in the vertical direction, and the lower movable electrodes are mounted on the respective lower movable electrodes. Positioning means for positioning the welded product to be welded to the formed work and restraining it to the welded product mounting portion of the work, and in the central part of the lower fixed electrode in a longitudinal shape in the central part of the lower movable electrode. An automatic welding device characterized in that an injection hole for ejecting air toward the formed hole is formed in a longitudinal shape.