JPH08318376A - Stud welding machine - Google Patents

Abstract

PURPOSE: To weld a male screw stud by arranging a cavity to accommodate the projecting part of a stud to tip part of a piston to push in a stud to be fed to a collet of stud welding machine. CONSTITUTION: In order to weld a male screw stud 9 having a welding part at its tip to a base material, a stud welding machine 10 is provided with a hollow collet 17 to hold the male screw stud 9, a feed tube 34 to feed the male screw stud 9 to the collet 17 and a piston 35 to push in the male screw stud 9 fed to the collet 17 so that the welding part 2 of male screw stud 9 is positioned at the tip of collet 17 and the male screw stud 9 is held to the collet 17. A cavity 42 to accommodate the projecting part 7 of male screw stud 9 being at opposite side to the welding part 2 is extended from the tip face of piston 35 in the axial direction. Further the stud welding machine 10 can weld a female screw stud, in which a female screw is formed to the inner side of shaft part extending from a flange part 5 to a welding part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stud welding machine for welding a stud having a welded portion at its tip and a flange at a position away from the welded portion to a base material such as a metal panel.

[0002]

2. Description of the Related Art There is known a stud welding machine for welding a stud having a welded portion at its tip and a flange at a position away from the welded portion to a base material such as a metal panel. As one of the stud welding machines, a hollow collet formed so as to elastically contact the flange side surface of the stud to hold the stud, a means for feeding the stud to the collet, and a tip of the collet. Some pistons push the studs fed into the collet so that the stud welds are located and the flange sides of the studs are held pressed by the collet.

[0003]

The stud welder described above is suitable for automatic welding of studs because the piston pushes the stud into the collet and holds it when the stud to be automatically fed is received at the collet inlet. A typical example of a stud used in a stud welder is shown in FIG. This stud 1 has a welded portion 2 at its lower end, and a welded portion 2 of the shaft portion 3
Is a female threaded stud having a flange 5 at the end opposite thereto and the shaft 3 having a female thread 6 formed on the shaft extending from the flange 5 to the weld. Recently, as shown in FIG. 2, a female screw is not formed on the shaft portion 3, and the welded portion 2 of the flange 5 is not formed.
A male screw stud 9 having a projecting portion 7 on the opposite side thereof and having a male screw formed on the projecting portion 7 is also used. When such a male screw stud 9 is welded using a conventional stud welder, the protruding portion 7 protrudes toward the piston, so that the fed stud cannot be properly pushed into the collet. there were.

Therefore, an object of the present invention is to provide a stud welding machine capable of properly holding and welding not only a female threaded stud but also a stud with a protruding portion which projects from a flange to the opposite side like a male threaded stud. To provide.

[0005]

In order to achieve the above object, according to the present invention, a stud having a weld at the tip and a flange at a position apart from the weld is welded to the base material. Hollow collet formed to hold the stud in contact with the flange side, means for feeding the stud to the collet, a stud weld at the collet tip, and the stud flange side by the collet. A stud welder for pushing a stud fed to a collet so as to hold the stud, wherein the piston has a protrusion protruding from a flange on a side opposite to the weld. A stud welder is provided, characterized in that a cavity for receiving the protrusion is formed so as to extend in the axial direction from the piston front end surface.

[0006]

As a result, not only the female threaded stud but also the stud with a protruding part that projects from the flange to the side opposite to the welded part such as the male threaded stud, the piston is pushed properly into the collet by the piston and the fed stud is pushed by the collet. Studs are held properly and welding is good

According to the present invention, the first stud feeding device for feeding the stud to the collet is the feeding pipe extending to the inlet of the collet and the male screw stud having the male screw formed on the protruding portion of the stud. And a second stud supply device for supplying a female screw stud having a female screw formed on a shaft portion extending from the flange to the welded portion without a protrusion, and the first stud supply device and the second stud supply device, respectively. Means for connecting to the feeding pipe, and selectively feeding male and female threaded studs to the first and second stud feeding devices connected to the collet through the coupling means.
It can be actuated, which allows selective welding of internal and external threaded studs.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 3, the stud welder 10
Includes a handle 11, a housing 14 for holding the cylinder portion 13, and a nose 15 provided in front of the cylinder portion 13, and a hollow collet 17 for holding a stud is attached to the tip of the nose 15. . Handle 1
1, a pipe 18 for various electric wires and a pipe 1 for compressed air
9 and 21, and a trigger switch 22 for starting the welding machine. Housing 14
Is integrally formed with the handle 11 and movably supports the inner cylinder portion 13.

An annular gap 23 is formed between the outer peripheral surface of the main body and the inner peripheral surface of the housing.
5 is arranged to press the cylinder portion 13 downward in FIG. A coil 26 for an electromagnet is provided on the inner surface of the housing facing the upper surface of the cylinder portion 13, and a core portion 27 for pulling up the cylinder portion 13 by the electromagnetic force of the coil 26 is provided on the upper surface of the main body portion. . Therefore, when current is supplied to the coil 26, the core portion 27 is pulled up, the cylinder portion 13 is pulled up against the force of the spring 25, and the cylinder portion 13 is pulled up, so that the nose 15 and the collet 17 are pulled up. Then, the weld of the stud held at the tip of the collet is pulled up from the base material. By this pulling up, the stud welded portion is pulled up from the base metal and arc discharge such as pilot arc and main arc is performed to melt the welded part of the stud and the corresponding portion of the base metal. After the melting, when the power supply to the coil 26 is stopped, the cylinder portion 13 is lowered by the force of the spring 25, and by this lowering, the welded portion of the stud comes into contact with the molten portion of the base material to complete welding. Since such welding method is known, further description will be omitted.

An arm 29 extends downward from the housing 14 or the handle 11 along the nose 15 and the collet 17, and the collet 1 is attached to the tip of the arm 29.
A tubular body 30 that surrounds the distal end portion of 7 is attached.
During use, the tip (lower end) of the tubular body 30 is pressed so as to come into contact with the welding position of the base material. By this abutment, the arm 29 supports the housing 14 and the handle 11 at a predetermined height position, and therefore the arm 29 and the tubular body 30.
Allows the stud to be positioned on the base material and the stud pull-up height to be determined.

The collet 17 has a longitudinal slit 31 formed at the tip thereof so as to elastically contact the flange side surface of the stud and hold the stud, and
The inner tip portion 33 tapers toward the tip such that the inner diameter is smaller than the outer diameter of the flange of the stud. Therefore, when the stud is pushed into the collet, the flange side surface of the stud is pressed and held by the collet 17.

A feed tube 34 extending to the entrance of the collet 17 is attached to the nose 15. This feeding tube 34 has one stud on the nose 15,
For example, it is fed by pressure with pressurized air.
In FIG. 3, the male screw stud 9 shown in FIG. 2 is fed in the direction of the arrow in the feeding tube 34 in the posture shown by the imaginary line, and is fed to the collet 17 as shown by the solid line.

A piston 35 is provided in a cylinder 37 inside the cylinder portion 13, and the piston 35 reciprocates in the cylinder 37. This reciprocating motion is controlled by compressed air. Now, when compressed air is supplied from the first compressed air pipe 19 to the first air supply port 38 on the lower end side of the cylinder 37, the piston 35 moves to the uppermost position in FIG.
Hold in non-weld position. Next, the first compressed air pipe 19
The supply of pressurized air from the
When compressed air is supplied from 1 to the second air supply port 39 on the upper end side of the cylinder 37, the piston 35 moves to the lowermost position and is held at the welding position. In this way, the piston 35
Is moved to the lower welding position, the tip (lower end) 41 of the piston pushes the stud in the collet 17 toward the tip of the collet to position the weld 2 of the stud 9 at the tip of the collet 17 and the flange of the stud 9. The side surface of 5 is pressed and held by the collet 17. The collet 17 is supplied with electric power for generating pilot arc discharge and main arc discharge between the stud 9 and the base material. Therefore, the side surface of the flange 5 of the stud 9 needs to be pressed and held by the collet 17 so that good electrical contact can be obtained.

As described above, the stud 9 supplied to the collet 17 by the movement of the piston 35 must be properly held at the tip of the collet 17 in order to properly perform the subsequent welding. In the case of the female screw stud 1 of FIG. 1, the tip of the piston 35 is the stud flange 5
The female screw stud 1 can be properly held by the collet 17 by simply pressing. Similarly, even when the protruding portion 7 protrudes toward the piston 35 as in the male screw stud 9 shown in FIGS. 2 and 3, the stud 9 must be properly held at the tip of the collet 17. Therefore, according to the present invention, the cylindrical cavity 4 extending in the axial direction so as to receive the protruding portion 7 of the male screw stud 9 is provided at the tip portion of the piston 35.
2 is formed so as to extend upward from the tip end surface of the piston 35. The inner diameter of the cavity 42 is formed to have a diameter sufficient to receive the protrusion 7 of the male screw stud 9.

In operation, first, as shown in FIG.
The piston 35 is held in the uppermost non-welding position in the cylinder 37 by the compressed air supplied from the first compressed air pipe 19 through the first air supply port 38 on the lower end side of the cylinder. The male screw stud 9 is supplied to the collet 17 from the feeding tube 34. Next, in the cylinder 37, the supply of the pressurized air from the first compressed air pipe 19 is stopped, and the second compressed air pipe 21 extends from the second compressed air pipe 21 to the second air supply port 3 on the upper end side of the cylinder.
Compressed air is supplied to 9. As a result, the piston 35 held in the non-welding position in FIG. 3 moves to the lowermost position and is held in the welding position as shown in FIG. At this time, the cavity 42 formed upward from the tip of the piston 35 receives the male thread forming protrusion 7 of the male thread stud 9, and the tip 41 of the piston 35 abuts the flange 5 of the stud 9. The stud 9 is pushed by the piston 35 into the collet 17 in a proper posture. By this pushing, the side surface of the flange 5 of the stud 9 is positioned in the small inner diameter portion 33 at the tip of the collet 17, the stud 9 is held in an appropriate posture by the collet 17, and sufficient power for arc discharge is supplied from the collet 17 to the stud 9. Secure a stable supply.

With the piston 35 held at the welding position shown in FIG. 4, the tubular body 30 at the tip of the positioning arm 29 is positioned so that the welded portion 2 of the stud 9 is located at a predetermined position on the base material (not shown). To contact the base material. By pressing the trigger switch 22, electric power for arc discharge is supplied between the stud 9 and the base material, and thereafter, electric current is supplied to the coil 26 to pull up the core portion 27. As a result, the cylinder portion 13 is pulled up against the force of the spring 25 to pull up the nose 15 and the collet 17, and the welded portion 2 of the stud held by the collet 17 is pulled up from the base material. By this pulling up, arc discharge such as pilot arc and main arc is performed to melt the welded portion of the stud and the corresponding portion of the base material. After the melting, the power supply to the coil 26 is stopped, the cylinder portion 13 is lowered by the force of the spring 25,
By this descending, the welded portion of the stud comes into contact with the molten portion of the base material, and welding is completed.

FIG. 5 shows how the female screw stud 1 of FIG. 1 is welded by the stud welder 10. Since the female screw stud 1 does not have the protrusion of the male screw stud, even if the piston 35 is moved to and held at the welding position,
Nothing is inserted into the cavity 42 at the tip of the piston 35. However, since the tip 41 of the piston 35 contacts the flange 5 of the female stud and the flange 5 of the stud 9, the female stud 1 is pushed into the collet 17 by the piston 35 in a proper posture. By this pushing, the stud 1 is attached to the small inner diameter portion 33 at the tip of the collet 17.
The side surface of the flange 5 is positioned so that the stud 1 is held by the collet 17 in a proper posture, and a sufficient supply of electric power for arc discharge is secured from the collet 17 to the stud 1.

FIG. 6 shows a system 43 for feeding studs to the feed tube 34 of the stud welder 10. This stud feeding system 43 includes a stud feeding pipe 45 connected to the feeding tube 34 of the stud welding machine 10, a first stud feeding device 46 for feeding a male thread stud, and a second stud feeding device 46 for feeding a female thread stud. It is provided with a stud supply device 47, and a device 49 for connecting the first stud supply device 46 and the second stud supply device 47 to the supply pipe 45, respectively. Stud feeding system 4
A control device (not shown) selectively activates the first stud supply device 46 and the second stud supply device 47 to selectively feed the male stud or the female stud through the coupling device 49. In addition, each stud supply device has 1
It is preferable that the automatic aligning and feeding device is configured so that each of them is fed in a fixed posture. An example of this automatic aligning and feeding apparatus is described in Japanese Patent Application No. 5-49338.

The stud used in the present invention uses a female screw stud and a male screw stud in the illustrated embodiment, but the present invention is not limited to this, and any stud having a welded portion and a flange can be used. Further, even a stud having no female screw or male screw formed therein, and any stud regardless of the presence or absence of a protrusion can be properly welded by the stud welding machine according to the present invention.

[0020]

According to the present invention, the piston is provided with a cavity for receiving the protrusion of the stud having a protrusion protruding from the flange on the side opposite to the welded portion, the cavity extending in the axial direction from the piston front end surface. Since it is formed, not only female threaded studs, but also male threaded studs with studs protruding from the flange to the opposite side from the welded part, the piston properly pushes the fed stud into the collet,
The collet holds the studs properly and allows for good welding.

[Brief description of drawings]

FIG. 1 is a front view of a half section of a female screw stud.

FIG. 2 is a front view of a male screw stud.

FIG. 3 is a vertical sectional view of the stud welder according to the present invention in a non-welded state.

4 is a longitudinal sectional view of the stud welder of FIG. 3 in a welded state.

5 is a vertical cross-sectional view of the stud welder of FIG. 3 using internal thread studs.

FIG. 6 is a schematic view of a stud welding system connected to a stud welding machine.

[Explanation of symbols]

 1 Female Threaded Stud 2 Welded Section 5 Flange 7 Projected Section 9 Male Threaded Stud 10 Stud Welder 11 Handle 13 Cylinder Section 14 Housing 15 Nose 17 Collet 22 Trigger Switch 26 Electromagnetic Coil 29 Positioning Arm 30 Slit 34 Feed Tube 35 Piston 37 Cylinder 38, 39 Compressed air supply port 42 Cavity 43 Stud feeding system 45 Stud feeding pipe 46, 47 Stud feeding device 49 Coupling device

Claims (4)

[Claims] 1. A stud having a weld at its tip and having a flange at a position away from the weld is welded to a base material, so that the stud is held in contact with the flange side surface of the stud. A hollow collet, a means for feeding a stud to the collet, and a piston for pushing the stud fed to the collet so that a stud weld is located at the tip of the collet and the flange side surface of the stud is held by the collet. In the stud welding machine, the cavity is formed in the piston, the cavity receiving the protrusion of the stud having a protrusion protruding from the flange on the side opposite to the weld, and extending in the axial direction from the piston front end surface. A stud welding machine characterized in that 2. The stud welder according to claim 1, wherein the stud is a male screw stud having a male screw formed on a protruding portion. 3. The stud welder according to claim 1, wherein the stud has no protruding portion, and the stud is a female threaded stud in which a female thread is formed inside a shaft portion extending from the flange to the welded portion. Stud welding machine characterized by. 4. The stud welding machine according to claim 1, wherein the means for feeding the stud to the collet is a feeding pipe extending to an inlet portion of the collet, and a male screw stud having a male thread formed on a protruding portion of the stud. And a second stud feeding device for feeding a female threaded stud having a female thread formed inside a shaft portion extending from a flange to a welded portion without a protruding portion, and the first stud feeding apparatus. Device and means for connecting the second stud supply device to the feed pipe, respectively, wherein the first and second stud supply devices select a male thread stud or a female thread stud for the collet through the connection means. Stud welder characterized by being actuated so as to mechanically feed.