JPH0871767A - Spot welding machine - Google Patents

Abstract

PURPOSE: To provide a spot welding machine capable of welding a stud bolt to a work without generating any spatter, and automatically feeding the stud bolt. CONSTITUTION: In a spot welding machine 1, in the condition where a work W is loaded on a lower electrode 5 and a stud bolt SV provided with a flange SVF on the tip is fitted to a hole 19 of an upper electrode tip 17, and sucked and held thereto, the flange SVF of the stud bolt SV is pressed against the work W to energize the lower electrode 5 and the upper electrode tip 17 to achieve the welding. A pressurizing cylinder 11 is provided on the upper electrode tip 17 through an electrode holder 15 so as to vertically move the upper electrode tip 17, and an air sucking and holding means to fit, such and hold the stud bolt SV is connected to the hole 19 of the upper electrode tip 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spot welding machine for welding a stud bolt to a work.

[0002]

2. Description of the Related Art Conventionally, as a spot welder for welding a stud bolt to a work, a welding gun and a welding power source dedicated to the stud bolt are provided to weld the stud bolt to the work.

[0003]

By the way, in the above-mentioned conventional spot welding machine, spatter may be generated at the welded portion between the work and the stud bolt. May need to be removed. In this case, there is a problem that productivity is poor because spatter is removed in a post process after welding.

It is an object of the present invention to provide a spot welder capable of welding a stud bolt to a work without generating spatter and further automatically supplying the stud bolt.

[0005]

In order to achieve the above object, a spot welding machine according to a first aspect of the present invention mounts a work on the lower electrode and mounts a stud bolt having a flange on the tip of the upper electrode tip. A spot welder that presses the flange of the stud bolt to the work while mounting it in a hole and holding it by suction to energize the lower electrode and the upper electrode tip to perform welding, and to move the upper electrode tip up and down. It is characterized in that a pressure cylinder is provided on the electrode tip via an electrode holder, and a stud bolt is attached to the hole of the upper electrode tip to connect an air suction holding means for suction holding.

The spot welding machine of the invention according to claim 2 is
2. The spot welding machine according to claim 1, further comprising a stud bolt automatic supply device which is adjacent to the upper electrode tip and is configured to automatically supply the stud bolt to the hole of the upper electrode tip and which is vertically movable and rotatable. It is what

The spot welding machine of the invention according to claim 3 is
The spot welding machine according to claim 1, wherein the pressurizing cylinder is provided so as to be movable back and forth, and a stud bolt is automatically supplied to a hole of the upper electrode tip at one end of the work table provided with the lower electrode in the front and rear direction. It is characterized in that it is provided with a cartridge type stud bolt automatic supply device which is movable left and right.

The spot welding machine of the invention according to claim 4 is
The spot welding machine according to claim 2 is characterized in that a stud bolt supply device is connected to the stud bolt automatic supply device via a bolt tube.

[0009]

With the spot welding machine according to the first aspect of the present invention as described above, a work is placed on the lower electrode and a stud bolt having a flange at the tip is attached to the hole of the upper electrode tip. Excuse me. Next, when the air suction / holding means is operated, the stud bolt mounted in the hole of the upper electrode tip is suctioned / held.

When the pressure cylinder is operated in this state, the upper electrode tip is lowered through the electrode holder and the flange of the stud bolt is pressed against the work. Moreover, by energizing the upper electrode tip and the lower electrode, the flange of the stud bolt is welded to the work without generating spatter.

With the spot welding machine according to the second aspect of the present invention, the stud bolt automatic supply device is rotated in a lowered state, and further raised so that the stud bolt is moved from the stud bolt automatic supply device to the upper electrode tip. Supplied automatically to the holes.

With the spot welding machine according to the third aspect of the present invention, the pressure cylinder is moved in the front-rear direction and positioned above the side on which the cartridge type stud bolt automatic feeder is located. Moreover, by positioning the supply position of the cartridge type stud bolt automatic supply device to the position below the upper electrode tip provided on the pressurizing cylinder through the electrode holder, the studs in the supply device of the cartridge type stud bolt automatic supply device are positioned. The bolts are automatically fed into the holes in the upper electrode tip.

According to the spot welding machine of the fourth aspect of the present invention, since the stud bolt feeder is connected to the stud bolt automatic feeder through the bolt tube, the stud bolt in the stud bolt feeder has only one stud bolt. The stud bolts are aligned one by one, and the stud bolts are continuously supplied to the automatic supply device one by one through the bolt tube.

[0014]

Embodiments of the present invention will be described in detail below with reference to the drawings.

Referring to FIG. 1, the spot welding machine 1 is provided with an upright box-shaped work table 3, and a lower electrode 5 on which a work W is placed is provided on the work table 3. There is. A support frame 7 is provided above the work table 3 so as to extend from and fixed to the work table 3.

A cylinder base 9 is attached to the support frame 7 with a plurality of screws, and a pressure cylinder 11 is provided on the cylinder base 9. An electrode holder 15 is integrated with the lower portion of the piston rod 13 mounted on the pressure cylinder 11. An upper electrode tip 17 is attached to the lower portion of the electrode holder 15 and is detachably provided.

The hole 19 which allowed to mounting the stud bolt SV having a flange SV _F at the tip is formed vertically in the upper electrode tip 17. One end of another hole 23 which is a part of the air suction holding means 21 is communicated with this hole 19, and an air joint 25 is connected to the other end of this hole 23. An ejector (vacuum generator) 29 is connected to the air joint 25 via an air tube 27.

With the above construction, when welding the stud bolt SV to the work W, the hole 1 of the upper electrode tip 17 is welded.
As shown in FIG. 2 in FIG. 9, when the stud bolt SV is mounted and the ejector 29 is actuated, the stud bolt SV is air-adsorbed and the stud bolt SV is in the hole 19 of the upper electrode tip 17.
Retained within.

When the pressurizing cylinder 11 is operated in this state, the upper electrode tip 17 is moved from the position indicated by the solid line in FIG.
When the stud bolt SV is pressed against the lower electrode 5 and the work W and the welding current is applied to the lower electrode 5 and the upper electrode tip 17, the work W is lowered.
Flange SV _F of the stud bolt SV can be easily welded without causing sputtering. Therefore, since no spatter is generated, it is not necessary to remove the spatter in the subsequent process.

FIG. 3 shows an example in which an automatic stud bolt supply device 31 is provided adjacent to the upper electrode tip 17 in the spot welding machine 1 shown in FIG. That is,
In FIG. 3, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 3, a rotary air cylinder 33 is provided below the cylinder base 9. A bolt tube 37 is attached to the rotary air cylinder 33 via a bracket 35. A plurality of stud bolts SV are inserted in the bolt tube 37 with the bolt direction aligned with the welding direction. An L-shaped support member 39 is integrated with the bracket 35, and a stud bolt escape air cylinder 41 is provided on the support member 39. The piston rod 43 mounted on the stud bolt escape air cylinder 41 is inserted into a hole formed in the lower side wall of the bolt tube 37.

An arm member 47 is integrated with the tip of the piston rod 45 mounted on the rotary air cylinder 33, and a bolt holder 49 is attached to the tip of the arm member 47. Moreover, the height adjusting screw 51 is inserted into the shaft center of the bolt holder 49 from below and is fixed by the nut 53. The bolt holder 49
Has a hole 55 for removing air. With the above structure, when the stud bolt SV is automatically supplied to the hole 19 of the upper electrode tip 17 by the stud bolt automatic supply device 31, the bolt holder 49 provided at the tip of the arm member 47 is located below the bolt tube 37. To position.

Next, the stud bolt escape air cylinder 41 is actuated to contract the piston rod 43, whereby the lowest stud bolt SV accommodated in the bolt tube 37 is dropped into the bolt holder 49. When the bottom stud bolt SV falls into the bolt holder 49, the piston rod 43 is extended and the stud bolt SV in the bolt tube 37 is prevented from dropping.

In this state, the rotary air cylinder 33 is operated to extend the piston rod 45 and the arm member 47 descends as shown by the arrow. When the arm member 47 is lowered to the lowered position, the arm member 47 is rotated 180 degrees as shown by the arrow so that the bolt holder 49 is positioned at the lower position of the upper electrode tip 17, and then the piston rod 45 is contracted. The holder 49 moves up and is brought into contact with the lower surface of the upper electrode tip 17 as indicated by the chain line. Then, when the ejector 29 is operated, the stud bolt SV in the bolt holder 49 is sucked into and held in the hole 19 of the upper electrode tip 17.

When the stud bolt SV is suction-held from the bolt holder 49 into the hole 19 of the upper electrode tip 17, the arm member 47 moves down, rotates, and moves up, and the bolt holder 49 moves to a position below the bolt tube 37. Is returned to its original position.

Next, when the pressure cylinder 11 is operated and the piston rod 13 is extended, the upper electrode tip 17 descends to the position of the chain double-dashed line via the electrode holder 15, and the lower electrode 5 and the work W are studded. bolt SV is pressurized, it is possible to further when the welding current to the lower electrode 5 and the upper electrode tip 17 is energized, the flange SV _F of the stud bolt SV to the workpiece W is easily welded without generating sputtering.

As described above, the stud bolt SV can be automatically supplied to the hole of the upper electrode tip 17 by the stud bolt automatic supply device 31 without manual labor.

FIG. 4 shows an example in which, for example, a parts feeder as a stud bolt supply device is connected to the bolt tube in FIG. That is, in FIG. 4, parts that are the same as the parts shown in FIG. 3 are given the same reference numerals, and duplicate explanations are omitted.

In FIG. 4, the stud bolt automatic feeder 31 is provided with another stud bolt feeder, for example, a parts feeder 57. Since this parts feeder 57 is already known, detailed description thereof will be omitted. However, when a plurality of stud bolts SV are supplied, the stud bolts SV are aligned one by one due to vibration, and the bolt passage 59 is formed.
And is temporarily stored in the bolt supply box 61 through the. One end of the bolt tube 37 is provided near the upper portion of the bolt supply box 61.

With the above structure, the stud bolt SV in the parts feeder 57 is sent to the bolt supply box 61 via the bolt passage 59. This bolt supply box 61
The stat bolts SV sent to the inside of the bolt tube 37 enter from one end of the bolt tube 37 into the bolt tube 37 by the injection of air, and one by one in the bolt holder 49 positioned at the other end of the bolt tube 37 continuously from the parts feeder 57. Supplied. The operation after the stud bolt SV has been fed into the bolt holder 49 may be performed in the same manner as the operation described in FIG. 3, so detailed description will be omitted.

Therefore, the stud bolts SV can be automatically supplied one by one from the parts feeder 57 to perform continuous welding.

FIG. 5 shows a spot welder 1 according to another embodiment. In FIG. 5, the spot welder 1 is provided with an upright box-shaped work table 3, and a support frame 7 is provided upright on the rear portion of the work table 3 so as to extend in the vertical direction. A beam member 65 extending in the front-rear direction is supported by a cantilever on the upper portion of the support frame 7 via a support block 63. This beam member 6
A plurality of guide rails 67 extending in the front-rear direction are laid on the lower surface of 5, and the pressure cylinder 11 is provided along the guide rails 67 so as to be movable in the front-rear direction.

An upper electrode tip 17 is provided on the tip of a piston rod 13 mounted on the pressure cylinder 11 via an electrode holder 15. This upper electrode chip 1
The air suction holding means 21 is provided in the hole 19 of No. 7 in the same manner as shown in FIG.

A lower electrode 5 extending in the front-rear direction is provided at a substantially central portion of the work table 3 in the left-right direction corresponding to the movement of the pressure cylinder 11. A guide rail 69 extending in the left-right direction is laid on the front part of the work table 3, and a plurality of work clamps 71 for clamping the work W are movably provided on the guide rail 69.

A cartridge type stud bolt automatic supply device 73 is provided on the front side wall of the work table 3. More specifically, referring also to FIG. 6, a support frame 75 extending in the left-right direction is attached to the front side wall of the work table 3, and the support frame 75 is sequentially mounted on the support frame 75 at a pitch S, for example, in the right direction. There is provided a cartridge 77 which is moved to. Stud bolts SV are attached to the cartridge 77 for each pitch S.

A positioning box 79 is provided in front of the lower electrode 5 for positioning the cartridge 77 by using, for example, a rack 77R and a pinion 77P as shown in FIG. The pinion 77P is connected to a cartridge feed motor 80 attached to the positioning box 79 via a bracket.
A push-up air cylinder 81 is provided below the positioning box 79, and a push-up pin 87 is provided at the tip of a piston rod 83 mounted on the push-up air cylinder 81 via a joint 85.

With the above construction, when the stud bolt SV in the cartridge 77 is mounted in the hole 19 of the upper electrode tip 17, the pressure cylinder 11 is guided by the guide rail 67.
Is moved to the front side along with and stopped when the upper electrode tip 17 reaches above the positioning box 79.

Next, by driving the cartridge feed motor 80 to rotate the pinion 77P with respect to the rack 77R, the cartridge 77 is moved to the right and the stud bolt SV in the cartridge 77 is moved to the position shown in FIG.
And the positioning box 7 as shown in FIG.
Position it at the center of 9. When the push-up air cylinder 81 is operated and the piston rod 83 is extended, the push-up pin 87 rises and pushes up the stud bolt SV to be mounted in the hole 19 of the upper electrode tip 17. The operation after the stud bolt SV is mounted in the hole 19 of the upper electrode tip 17 may be performed in the same manner as the operation described with reference to FIG. 1, and thus detailed description will be omitted.

Therefore, the cartridge type stud bolt automatic supply device 73 is provided on the front side wall of the work table 3, for example.
By providing the cartridge type stud bolt automatic supply device 73, the stud bolts SV can be automatically supplied one by one to the holes 19 of the upper electrode tip 17, and the pressurizing cylinder 11 can be moved forward and backward. The stud bolt SV can be easily and automatically welded to the work W by locating in the left-right direction.

The present invention is not limited to the above-described embodiments, but can be implemented in other modes by making appropriate changes.

[0041]

As will be understood from the above description of the embodiment, according to the invention of claim 1, when the stud bolt is mounted in the hole of the upper electrode tip, it is sucked and held by the air suction holding means. When the pressure cylinder is operated in this state, the stud bolt is pressed against the work,
By energizing the upper electrode tip and the lower electrode, the stud bolt can be easily welded without generating spatter.

According to the second aspect of the invention, the stud bolt can be automatically mounted in the hole of the upper electrode tip by the stud bolt automatic feeder. According to the third aspect of the present invention, the stud bolts can be automatically attached to the holes of the upper electrode tip one by one from the cartridge type stud bolt automatic feeder. According to the fourth aspect, continuous welding can be performed because the stud bolt feeders such as the parts feeder are continuously fed one by one to the stud bolt automatic feeder.

[Brief description of drawings]

FIG. 1 is a front view of a spot welding machine according to an embodiment of the present invention.

FIG. 2 is an explanatory view of an operation of welding a stud bolt to a work by the spot welding machine of FIG.

FIG. 3 is a front view of the spot welding machine of FIG. 1 provided with an automatic stud bolt supply device.

FIG. 4 is an explanatory diagram in which a stud bolt supply device such as a parts feeder is connected to the stud bolt automatic supply device in FIG.

5 is a perspective view of a spot welding machine of another embodiment replacing FIG.

FIG. 6 is an enlarged perspective view of a VI arrow portion in FIG.

7 is a front cross-sectional view of a VII arrow part in FIG.

[Explanation of symbols]

1 Spot Welder 3 Work Table 5 Lower Electrode 11 Pressurizing Cylinder 15 Electrode Holder 17 Upper Electrode Tip 19 Hole 21 Air Adsorption Holding Means 23 Hole 25 Ejector 31 Stud Bolt Automatic Supply Device W Work SV Stud Bolt SV _F Flange

Claims (4)

[Claims] 1. A workpiece is placed on a lower electrode, and a stud bolt having a flange at the tip thereof is attached to a hole of an upper electrode chip and sucked and held to the workpiece to press the flange of the stud bolt to form a lower electrode. A spot welding machine for energizing the upper electrode tip to perform welding, wherein a pressure cylinder is provided on the upper electrode tip via an electrode holder to move the upper electrode tip up and down, and a stud is formed in a hole of the upper electrode tip. A spot welding machine, characterized in that an air suction holding means for mounting a bolt and holding the suction is connected. 2. A stud bolt automatic feeder which is adjacent to the upper electrode tip and which automatically feeds a stud bolt into a hole of the upper electrode tip and is vertically movable and rotatable. 1. The spot welder described in 1. 3. The pressurizing cylinder is provided so as to be movable back and forth, and a stud bolt is automatically supplied to a hole of an upper electrode tip at one end of the work table provided with the lower electrode in the front and rear direction. 3. A cartridge type stud bolt automatic supply device is provided.
Spot welder described. 4. The spot welding machine according to claim 2, wherein the stud bolt feeder is connected to the stud bolt automatic feeder through a bolt tube.