JP2000190077A - Stud welding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stud welding device for elongating a life of a stopper part of a collet guide which restrains stud parts when the stud parts are set at a weldable position in the collet guide. SOLUTION: To a collet guide 10, a flange-shaped stopper part 12 is formed at its tip part and plural slots are formed enlargeably. To a collet 20, a truncated cone shaped taper part 22 enlarged towards the tip in an inner periphery is formed at its tip end and plural slots are formed enlargeably. The collet 20 is driven forwards/backwards in the collet guide 10 by a collet driving means 29. A projection part 25 is formed on an outer periphery at rearwards rather than the tip of the collet 20. When the collet 20 for holding a bolt 1 coaxially is forwarded on an inner peripheral face rearward from the tip of the collet guide 10, the projection part 25 is interfered, so as to form a projection part 15 having an inclined face 15a being push-up driven.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stud welding apparatus for stud welding rod-like stud parts such as bolts and round bars to a base material.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show a stud welding apparatus of this kind, in which a flange-like stopper 7a is formed at the distal end, and a slit 7b is provided so as to be able to expand from the stopper toward the proximal end. In the collet guide 7 formed in a plurality of sections,
The bolt 1 as a stud component is supplied from a supply port 7c. In this supply state, a truncated conical tapered portion 8a is formed at the distal end, and a collet 8 having a plurality of slits 8b formed to be expandable from the tapered portion is driven from behind to forward.

That is, when the bolt 1 is implanted in the base material, as shown in FIG. 5A, the bolt 1 is moved from the feeder to the supply port 7c.
Through the collet guide 7. Then
When the collet 8 is driven forward, the bolt 1 is constrained by the stopper 7a and the truncated cone-shaped tapered portion 8a
To scoop up from behind (Fig. B). further,
As the collet 8 advances, the collet 8 expands and holds the bolt 1 coaxially, and the small-diameter bolt tip portion 1b is moved to the inner cylindrical portion 8c.
And the driving portion 8d at the leading edge of the
Then, it is brought into contact with the driven portion 1c around (b) in FIG. In this state, as shown in the enlarged view of the circle A, the curved peripheral edge 1d of the flange-like bolt base 1a contacts the inclined inner surface of the stopper 7a. Subsequently, as the collet 8 advances to the final position, the bolt base 1a presses and expands the stopper 7a, and further advances slightly to advance the bolt base 1a.
Is set to a welding-possible position (D in the same figure), and electricity is applied to the base material through the collet 8 and the bolt 1 to perform welding.

[0004]

However, in this apparatus, the stopper portion of the collet guide is driven and expanded by driving the stopper portion of the collet guide at the base of the stud component such as the bolt base. As a result, when the stud component is restrained by the stopper portion and is picked up and held by the frusto-conical taper portion, the stud component sometimes jumps forward.

In view of the above, the present invention provides a stud welding apparatus capable of extending the life of a stopper portion of a collet guide that restrains a stud component when the stud component is set at a weldable position in the collet guide. The purpose is to do.

[0006]

In order to achieve this object, according to the present invention, according to the first aspect, a flange-shaped stopper portion is formed at a tip portion, and a plurality of slits are formed so as to be expandable. At the same time, a collet guide having a supply port through which the stud component is supplied, and a truncated conical tapered portion whose inner peripheral surface expands toward the front are formed at the tip, and a plurality of slits are formed so as to be expandable. A collet and collet driving means for driving the collet forward and backward in the collet guide are provided, and when the collet is driven forward, the stud part whose base is restrained by the stopper is picked up by the frusto-conical taper part and expanded. With the base of the stud part set at a weldable position slightly ahead of the flange-shaped stopper part that is held coaxially and further advanced and expanded, move the stud part to the base material. In the stud welding device adapted to weld the base material of the stud parts by electrodeposition,
A protrusion is formed on the outer peripheral surface of the collet closer to the rear than the tip of the collet, and the outer peripheral surface of the collet when the collet holding the stud component coaxially further advances on the inner peripheral surface of the collet guide closer to the rear than the front of the collet guide A projection having an inclined surface that is driven up by interference with the projection.

In the process of driving the collet forward by the collet driving means, the stud component is scooped up by the frusto-conical tapered portion while the base of the stud component is restrained by the stopper portion. The protruding parts of are brought close. As the collet finally moves forward,
The projection of the collet guide is pushed up along the inclined surface by the interference of the both projections, and the stud component is set to a weldable position with the collet guide and its stopper expanded.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A stud welding apparatus according to an embodiment of the present invention will be described with reference to FIGS. This welding device is basically the same as the above-mentioned conventional one as schematically shown in FIG. 1, and a collet for guiding the bolt 1 to move forward while positioning the bolt base 1a so as to be weldable. A guide 10, a bolt feeder 9 for supplying a bolt 1 into a collet guide 10 from a supply port 7c provided at an intermediate position thereof, and a collet 20 for scooping up the bolt 1 from behind and holding it coaxially while advancing in the collet guide 10. The collet is provided with a collet driving means 29 using an air cylinder, which controls the forward movement of the collet by a predetermined stroke when welding the bolt 1 and retracts the collet when supplying the bolt.

As shown in FIG. 2, the collet guide 10 has a flange-shaped stopper portion 12 at a tip end thereof, and a plurality of slits 11 formed from the front side so as to be expandable. According to the present invention, the stopper portion 12 is formed wider than the above-described conventional stopper portion except for a small opening at the center. Further, an inclined surface 15a whose inner diameter gradually decreases toward the front is formed on the inner peripheral surface closer to the rear than the front end, and the front side is formed as a protrusion 15 whose inner diameter decreases.

As shown in FIG. 2, the collet 20 is formed with a frustoconical tapered portion 22 having an inner peripheral surface expanding toward the front, and a plurality of slits 21 formed from the front so as to be expandable. An inner cylindrical portion 28 is formed at the center. According to the present invention, each outer cylindrical portion 2 having a hemispherical projection 25 divided by a slot 21 is provided on the outer peripheral surface closer to the rear than the tip.
It is formed every 1a. The position of the protruding portion 25 is such that the bolt base 1a is restrained by the stopper portion 12, the bolt tip 1b slightly enters the inner cylindrical portion 28, and is held coaxially by the outer cylindrical portion 21a. Is set so as to abut or approach the inclined surface 15a.

The operation of the stud welding apparatus thus configured will be described with reference to FIG. The bolt 1 is fed from the bolt feeder 9 into the supply port 7c, and the collet guide 10
(See FIG. A). Next, while the collet 20 is being driven forward by the collet driving means 29, the bolt base 1a is lifted up by the frusto-conical tapered portion 22 while being restrained by the stopper portion 12 (see FIG. B), and further advanced. The outer tube portion 2 which has the front end portion 1b slightly penetrated into the inner tube portion 28, is positioned at the center portion, and is expanded.
At 1a, it is held coaxially, and the protrusion 25 is brought close to the protrusion 15 (see FIG. C). When the bolt is further advanced, the bolt tip 1b penetrates deeper into the inner cylindrical portion 28, and the hemispherical protrusion 25 interferes with the protrusion 15 and is driven up along the inclined surface 15a. The stopper portion 12 is expanded. With the stopper portion 12 expanded so as not to interfere, the bolt 1 advances slightly further, and is finally set to a weldable position (see FIG. D).

When the collet 20 is driven forward in the collet guide 10, electricity is supplied to the base material through the collet 20 and the bolt 1 by a conductive device near the side surface of the collet driving means 29, and arc welding or resistance welding is performed. Thereby, the bolt 1 is welded to the base material and implanted. At this time, since the expansion of the stopper portion 12 depends on the driving of the inner peripheral surface of the collet guide 10, and since the stopper portion 12 is also wide, not only the load on the stopper portion 12 is avoided, but also Since the degree of opening and closing of the stopper portion 12 with respect to the forward stroke of the collet 20 can be increased, the stopper portion 12 can be formed wider, and thus the stopper portion 12 can be formed.
Can be made more robust, and coaxial holding can be reliably performed.

In the above-described embodiment, the present invention is also applied to stud welding of a simple round bar as a stud part. In this case, as shown in FIG.
Is formed in a curved shape so that it can be scooped up. The collet 30 does not include the inner cylindrical portion, and holds the round bar 2 coaxially at the entry position only by the slit outer cylindrical portion 31.

[0014]

As described above, according to the present invention, the stopper portion of the collet guide is expanded and driven not by direct driving but by pushing up the inner peripheral surface of the collet guide. It becomes difficult and the life is extended, the mounting failure is reduced, and the replacement cycle is lengthened. Therefore, maintenance man-hours, that is, running costs are also reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a stud welding apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of a collet and a collet guide of the stud welding apparatus.

FIG. 3 is a sectional view for explaining the operation of the stud welding apparatus.

FIG. 4 is a cross-sectional view of a collet guide portion according to another embodiment.

FIG. 5 is a diagram illustrating the operation of a conventional stud welding device.

FIG. 6 is a perspective view of a collet and a collet guide of the stud welding apparatus of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bolt 7c Supply port 10 Collet guide 12 Stopper part 15, 25 Projection part 15a Inclined surface 20, 30 Collet 22 Taper part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masafumi Kawaura Kanagawa Automobile Industry Co., Ltd. (72) Taura Port Town, Yokosuka City, Kanagawa Prefecture Inside

Claims (1)

[Claims] 1. A collet guide having a flange-shaped stopper formed at a distal end thereof, a plurality of slits formed so as to be expandable and having a supply port through which stud components are supplied, and an inner peripheral surface facing forward. A collet in which a frustoconical taper portion expanding toward the tip is formed at the tip end, and a plurality of slits are formed so as to be expandable and expandable, and collet driving means for driving the collet forward and backward in the collet guide. By being driven forward, the stud part whose base is constrained by the stopper is picked up by the truncated conical taper, held coaxially by expansion, and further advanced to slightly ahead of the flanged stopper that has expanded. With the base of the stud component set in the weldable position, the stud component is welded to the base material by applying electricity to the base material from the stud component. In the contacting device, when the collet holding the stud component coaxially further forward is formed on the inner peripheral surface of the collet guide closer to the rear than the front end of the collet, the protrusion is formed on the outer peripheral surface of the collet closer to the rear than the front end of the collet. A stud welding device, wherein a projection having an inclined surface that is driven up by interfering with the projection is formed.