JPH0523865A - Method for supplying shaft like part to fixed electrode - Google Patents

Abstract

PURPOSE:To surely execute centering the part on the transitional period for introducing and to smoothly introduce by eliminating the part holding force of the supplying rod almost at the same time when the top end part of the shaft like part enters in the recessed part of the guide pin by advancing the supplying rod. CONSTITUTION:At the instant when a supplying rod 6 advances and a top end part of a bolt enters slightly in a recessed part 49, the advance of this supplying rod 6 is stopped, the part holding force of the part rod 6 is eliminated. That is, if the supplying rod 6 is stopped, because an engaging piece 25 pulls a restricting pin 20 up with the operation of an air cylinder 23, so an inner shaft 17 is retreated forcibly and a magnet 18 is separated also from the bolt 1, and the magnetic force to the bolt 1 is eliminated. By eliminating the holding force, a small diameter part 5 of the bolt 1 enters in the recessing part 49 while a flange 3 of the bolt 1 moves with sliding on the guide billet 7, and the guide pin 41 lowers at the same time. Therefore, it is introduced in the receiving hole 40 in the state being executed with centering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supplying a shaft-shaped part to a receiving hole of a fixed electrode of a projection welding machine.

[0002]

2. Description of the Related Art First, as a first conventional example, Japanese Patent Laid-Open No.
-108472 publication "electrode for projection welding". In this, the guide pin of the fixed electrode has a shape like a hollow pipe, and a bolt is inserted therein.

As a second conventional example, Japanese Patent Application No. Sho 63 is used.
There is a published microfilm of -60355 application "Spot Welder Electrodes". This is a type in which the tip of the bolt is pressed into the concave portion of the tip of the guide pin and inserted into the fixed electrode while holding the bolt on the supply rod.

[0004]

In the above-mentioned first conventional example, since the bolt enters into the guide pin in a free-falling manner, the tip portion of the bolt has no core during the transitional period of entry of the bolt. There is a problem that it has not been put out and therefore it is not possible to enter smoothly.

Further, in the second conventional example, since the bolt is retained on the supply rod until the completion of the advance of the bolt, the entire supply rod must always be accurately moved in the advance direction during the advance. Therefore, it is necessary to specially provide a moving mechanism for the supply rod, which is a disadvantage for simplifying the device.

[0006]

Means for Solving the Problem and Its Action The present invention has been made in view of the above problems. Claim 1 holds a shaft-shaped component at the tip of a supply rod. In the type that co-feeds to the guide pin inserted into the fixed electrode of the projection welding machine, the guide pin is provided with a recess at its tip and can be moved back and forth by the drive means, so that the feed rod comes forward. At about the same time that the tip of the shaft-shaped component enters the recess, the component-holding force of the supply rod disappears, and the guide pin is retracted to introduce the shaft-shaped component into the accommodation hole of the fixed electrode. The feature is that the tip of the shaft-shaped component engages with the recess of the guide pin and then the guide pin descends to complete the introduction into the fixed electrode. Further, according to claim 2, the time when the component holding force of the supply rod is extinguished is the time when the tip of the shaft-shaped component comes close to the recess, and the shaft-shaped component is dropped in a state where it falls for a short time. It enters into the inside, and after that, it is introduced like the above-mentioned invention.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the embodiment of FIGS. 1 to 4 will be described. The shaft-shaped component 1 dealt with here is a shaft portion 2 having a screw formed on the outer periphery thereof and a flange integrated with the upper end thereof. 3 is a projection bolt composed of a welding projection 4 provided on the lower surface of the flange and a small diameter portion 5 provided at the lower end of the shaft portion 2, and is made of iron. The feed rod 6 which makes an advance / retreat stroke is designed to receive the flange 3 in close contact with the tip end surface thereof, and the guide piece 7 protruding from the feed rod 6 serves as a stopper. The supply rod 6 is housed in an outer cylinder 8, and a piston rod 10 of an air cylinder 9 fixed to the supply rod 6 is connected to an upper end of the supply rod 6 so that the supply rod makes an advance / retreat stroke. The supply rod 6 is supported by a support piece 11 welded to the lower end of the outer cylinder 8, and a magnet (permanent magnet) 12 for accelerating the entry and transition of the bolt 1 is embedded inside the support rod 11, and its surface is It is covered with a cover plate 13. The outer cylinder 8 is firmly fixed to the stationary member 15 via the bracket 14.

Various means such as a chuck mechanism and an electromagnet can be considered as a means for holding the bolt 1 on the supply rod 6, but in this case, the supply rod 6 has an inner-outer double structure and a magnet (permanent magnet) is used. Is illustrated.
An inner shaft 17 is slidably inserted into the hollow shaft 16, and a magnet (permanent magnet) 18 is embedded at the tip of the inner shaft 17 and covered with a cover plate 19 (see FIG. 3). A restriction pin 20 is fixed to the upper end of the inner shaft 17, and protrudes outside through a long hole 21 opened in the stroke direction of the hollow shaft 16. The tension of the coil spring 22 installed in the hollow shaft 16 acts on the inner shaft 17, whereby the restriction pin 20 abuts on the lower end of the elongated hole 21. Further, in this state, the lower end surfaces of the hollow shaft 16 and the inner shaft 17 form a single plane to allow the flange 3 to be in close contact with each other. An air cylinder 23 is fixed to a side surface of the outer cylinder 8, and an engagement piece 25 is coupled to a piston rod 24 of the air cylinder 23. The engagement piece 25 is inserted from a long hole 26 opened in the longitudinal direction of the outer cylinder 8.
Project inside the outer cylinder 8. The relative positions of the two are set so that when the supply rod 6 advances by a certain amount, the restriction pin 20 stops immediately before the engaging piece 25.

Component supply pipe 27 guiding the bolt 1
The supply pipe (hereinafter referred to simply as the supply pipe) is installed in a direction intersecting with the stroke direction of the supply rod at an acute angle as shown in the drawing, and its end portion 28 is disposed near the tip end portion of the supply rod 6. There is. A stopper member 29 is formed at the tip of the supply pipe 27 so as to close the pipe end. An outlet hole 30 is formed on the lower side of the end portion 28, that is, the front end portion side of the supply rod 5 as shown in the drawing, and a holding piece 31 is installed in the portion so that the holding piece 31 can advance and retreat.
The shaft 1 of the bolt 1 that has descended is locked at a narrow portion between the inner surface 32 of the end 28 and the holding piece 31 as shown in the figure, and is in a so-called temporary locking positioning state. The inner surface 32 of the end portion 28 is provided with the thick portion 33 to have a sectional shape suitable for accommodating the shaft portion 2 as shown in FIG. The supply pipe 27 is welded to the outer cylinder 8 (see reference numeral 34).

A method of advancing and retracting the holding piece 31 is shown in FIG. 2. An air cylinder 36 is fixed to a bracket 35 connected to the outer cylinder 8, and a piston rod 37 of the air cylinder 36 is fixed to the holding piece 31.
Connected to. In the illustrated embodiment, the supply rod 6 is inclined by about 30 degrees with respect to the vertical line, and the supply pipe 27 is welded at a position 34 so as to be located above the outer cylinder 8. ing. Further, in order to make the magnetic force of the magnets 18 and 12 stronger against the bolt 1, the inner shaft 17, the hollow shaft 16, the cover plate 19, the outer cylinder 8, the support piece 11, the cover plate 13 and the like are non-magnetic materials. It is suitable to make it from some stainless steel. Furthermore, the supply pipe 27
A flexible synthetic resin supply hose 38 extending from a parts feeder (not shown) is connected to the.

A housing hole 40 penetrates through the central portion of the fixed electrode 39, and a guide pin 41 is slidably inserted into the housing hole 40. The fixed electrode 39 is firmly fixed on the base 42, and there are various methods such as a driving means 43 installed in the base 42 and an electromagnetic solenoid as this means. Here, an air cylinder 44 is exemplified. There is. The piston rod 45 of the air cylinder 44 in the base 42 is connected to the lower end of the guide pin 41. A small diameter portion 46 is provided at the upper end of the guide pin 41, and that portion projects from the upper surface of the fixed electrode 39, and a steel plate component 47 is provided there.
The lower hole 48 (see FIG. 4) is fitted to the steel plate component 47.
Are positioned. A recess 49 is provided at the center of the small diameter portion 46, and the tip of the bolt is inserted into the recess 49. The movable electrode 50 is the fixed electrode 39.
It is installed coaxially with.

In FIG. 1, the bolt 1 is held by the supply rod 6 as shown by the solid line, but the operation will be described assuming that the bolt 1 is not held in this manner.
The bolt 1 that has descended is temporarily locked as shown by the chain double-dashed line, and when the holding piece 31 retracts, the magnet 18
The bolt 1 is moved to the right from the outlet hole 30 by the suction force of 12 and 12, and at the same time as the flange 3 contacts the guide piece 7, it is held in close contact with the lower end surface of the supply rod 6 as shown by the solid line. Next, almost at the same time that the supply rod 6 advances and the tip of the bolt 1 (the small diameter portion 5) enters the recess 49, in other words, the bolt tip reaches the recess 49 from immediately before the bolt tip comes immediately before the recess 49. When it slightly approaches, the advance of the supply rod 6 is stopped and the component holding force of the supply rod 6 is eliminated.

The disappearance of the holding force is achieved by retracting the magnet 18 as shown in FIG. That is, when the supply rod 6 advances to the above-mentioned position and stops, the engagement piece 25 is actuated by the operation of the air cylinder 23.
Since 0 is pulled up, the inner shaft 17 is forcibly retracted, the magnet 18 is also separated from the bolt 1, and the magnetic force to the bolt 1 disappears.

As the holding force disappears as described above, the flange 3 of the bolt 1 slides on the guide piece 7 as shown in FIG.
As described above, the small-diameter portion 5 enters the concave portion 49 along an arcuate locus, and the guide pin 41 descends at the same time or at a timing slightly behind. Therefore, the tip of the bolt 1 is positioned in the recess 49, that is, the bolt 1 is introduced into the accommodation hole 40 from the lower hole 48 in a state of being centered.

Next, the embodiment of FIG. 5 will be described.
This is because the supply rod 6 strokes in the horizontal direction, and the members having the same functions as those of the previous embodiment are designated by the same reference numerals, and detailed description thereof is omitted. A supply pipe 51 is provided so as to match the retracted position of the supply rod 6 (the position indicated by the chain double-dashed line). In this embodiment, the component holding force is extinguished when the tip of the bolt 1 comes near the recess, that is, right above the guide pin 41 as shown in the figure.

A magnet 52 is attached to the guide pin 41 shown in FIG.
Embedded therein, the connection between the bolt 1 and the guide pin 41 is made more reliable.

As described above, in the structure as the method of the present invention, it is important to determine the timing for eliminating the component holding force.

[0018]

[Effects] According to the present invention, since the tip end of the shaft-shaped component is introduced into the recess of the guide pin in a kind of connection state, the component is reliably centered during the transition period of introduction, Smooth introduction is possible. Further, since the supply rod stops at a position apart from the guide pin to some extent, and thereafter the component holding force disappears at a predetermined time, the supply rod itself only needs to have a simple reciprocating stroke, Therefore, it is not necessary to obtain the complicated behavior as in the conventional example.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view of an entire apparatus used in the method of the present invention.

FIG. 2 is a sectional view taken along line (2)-(2) of FIG.

FIG. 3 is a vertical sectional side view showing a transitional transition period of a bolt.

FIG. 4 is a vertical sectional side view showing a state in which a bolt is introduced.

FIG. 5 is a vertical sectional side view showing another embodiment.

FIG. 6 is a partial vertical side view showing a modification of the guide pin.

[Explanation of symbols] 6 Supply rod 1 Shaft-shaped parts 39 fixed electrode 41 guide pin 49 recess 43 Drive means 40 accommodation hole

Claims (2)

[Claims] 1. A type in which a shaft-shaped component is held at the tip of a supply rod and is supplied to a guide pin inserted into a fixed electrode of a projection welding machine, and the guide pin has a recess at the tip thereof. It can be moved forward and backward by the driving means, and almost at the same time when the tip of the shaft-shaped component enters the recess when the supply rod advances, the component holding force of the supply rod disappears and the guide pin is retracted. A method of supplying a shaft-shaped component to a fixed electrode, characterized in that the shaft-shaped component is introduced into a housing hole of the fixed electrode. 2. The shaft-shaped component according to claim 1, wherein the component-holding force of the supply rod is eliminated when the tip of the shaft-shaped component comes close to the recess. Method.