JPH0857659A - Electrode of projection welding and the like - Google Patents

Abstract

PURPOSE: To electrically and surely detect whether a part is correctly entered into receiving hole in the electrode having receiving hole. CONSTITUTION: An electricity conducting member 14 is arranged at the bottom part of receiving hole 21, when a part 2 is brought into contact with the conducting member 14, electrical conducting is caused. The conducting member 14 is divided into moving members 17, 18 and a fixed member 15, a coil spring is inserted between both members, further all are connected by conducting line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode for projection welding or the like, and is used in a field in which a shaft-shaped part is inserted into a receiving hole of an electrode for welding.

[0002]

2. Description of the Related Art There are various methods for electrically detecting a shaft-shaped component such as a projection bolt which has been inserted into a receiving hole of an electrode and confirming that the component is normally present therein. Although a method is known, conventionally, there is known one in which a sensor is arranged in the vicinity of the receiving hole and the presence of a component is detected by an electric signal obtained from the sensor.

[0003]

In the above prior art, it is necessary to mount a sensor for detecting a part on the side of the electrode, which increases the number of parts and the mounting space, thus making the electrode itself compact. Very disadvantageous to More importantly, in terms of further improving the detection accuracy of parts, the sensor may not be perfect depending on the mounting method and the accuracy of the sensor itself. Such a demand for accuracy leads to a serious problem of lack of parts in the product because the process is advanced to the next process without the existence of parts.

[0004]

Means for Solving the Problem and Its Action The present invention is provided to solve the above-mentioned problems.
According to a first aspect of the present invention, a conductive member is installed deep inside the receiving hole of the component, and the component is brought into contact with the conductive member to establish electrical conduction for component detection. When a shaft-shaped component such as a bolt is inserted into the receiving hole, the tip of the component comes into contact with the conductive member, and an electric signal indicating the presence of the component is emitted, and the component detection is completed. if,
If the component is absent for some reason, no electric signal is emitted, and the next operation is stopped based on that. According to a second aspect of the present invention, in the first aspect, the conducting member is composed of a pair of a movable member and a fixed member that are in contact with each other, and a coil spring is interposed between both members, and both members are connected by a conducting wire. When the electrode is pressed against the counterpart steel plate component, the contact pressure between the component and the movable member increases due to the elastic reaction force of the coil spring, so that electrical continuity is reliably achieved in this part. Then, electricity can be surely applied to the fixing member through the conducting wire.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the embodiment of FIG. 1 will be described. The electrode 1 here is for projection welding.
Further, the component 2 is a projection bolt and is composed of a shaft portion 3, a flange portion 4 and a welding projection 5. The main body 6 is made of a copper alloy, the welding side member 7 and the fixed side member 8 are integrated by a screw portion 9, and a copper alloy end cover 10 is integrated by a screw portion 11 at the tip of the welding side member 7. Has been done. The main body 1, a guide cylinder described later, and the like have a circular cross-sectional shape, and a cylindrical guide cylinder 12 made of an insulating material is inserted therein and is integrated by a fixing pin 13. A coil spring 16 is interposed between the conducting members 14 and 15, and the conducting member includes a movable member 14 and a fixed member 15 installed as a pair. The movable member 14 is made of a material such as chrome copper. The receiving member 17 having a circular cross section and the circular conducting plate 18 also made of a material such as chrome copper are in close contact with each other as shown in the figure. The other fixing member 15 is also a disk-shaped member made of a material such as chrome copper. The conducting plate 18 and the fixing member 15 are connected by soldering both ends of the conducting wire 19 to each other.
Has a slack as shown in the figure.

The guide cylinder 12 is preferably made of Teflon resin, the internal through hole is composed of a large diameter portion 20 and a small diameter portion 21, and a receiving member 17 is accommodated in the large diameter portion 20,
The guide pin 22 integrated with the receiving member 17 enters the small diameter portion 21. The small-diameter portion 21 forms a receiving hole (hereinafter referred to as "this") for the shaft portion 3, and the through hole 23 opened in the end cover 10 is aligned with the receiving hole 21. The inner diameter of the through hole 23 is set to be slightly larger than the outer diameter of the shaft portion 3, and the dimensions are set so that the shaft portion 3 contacts the inner surface of the through hole 23.

An insulating cup 24 made of an insulating material (for example, Teflon) is fitted inside the fixed-side member 8, and a fixing member 15 for conduction is fixed to the inner portion thereof. An electric wire 25 is connected to the fixing member 15 and is led to the outside through the inside of the insulating pipe 26. The other electric wire 27 is the main body 6
(In the illustrated case, the fixed side member 8) is connected.

In the embodiment shown in FIG. 1, the electrode 1 is a movable electrode, and the fixed electrode paired with the movable electrode is indicated by reference numeral 34, and the steel plate component 35 is in close contact with the fixed electrode 34. The means for positioning and holding the steel plate component 35 is omitted in the drawing.

There are various methods for supplying the bolt 2 to the receiving hole 21, but here, as illustrated in FIG. 3, the supplying rod 31 which performs square motion as shown by arrows 28, 29 and 30 is illustrated. did. That is, the end of the supply rod 31 has a recess 32 opened toward the tip side.
Is formed therein, and the flange 4 is received therein, and a magnet 33 is embedded in the bottom of the recess 32 for holding the bolt 2.

The operation of the above embodiment will be described below.
Shaft part 3 by square motion of supply rod 31
Is inserted into the receiving hole 21 through the through hole 23 and the supply rod 3
When 1 returns in the direction of arrow 30, the bolt 3 descends toward the back of the receiving hole 21 by its own weight, and the tip of the bolt 3 contacts the guide pin 22. By this contact, the electric wire 25 fixing member 15, the conducting wire 19, the conducting plate 18, the receiving member 17,
The guide pin 22, the bolt 2, the inner surface of the through hole 23, and the energization path of the main body 6 are established, and such energization makes it possible to detect that the bolt 2 is present in the receiving hole 21. . If the bolt 2 does not exist in the receiving hole 21 or does not normally reach the inner part of the receiving hole 21, the bolt 2 and the guide pin 22
Since the electrical contact with is not established, the above-mentioned energizing path is not formed, and therefore, the detection signal of the presence of the component is not issued. Although not shown, the stroke operation of the electrodes is prevented from being triggered by the fact that this detection signal is not output.

When the electrode 1 rises while the bolt 2 is in contact with the guide pin 22 and the flange 4 is pressed against the opposing steel plate component 35, the coil spring 16 is compressed and the movable member 14 retracts in the large diameter portion 20. As a result, the flange 4 is brought into close contact with the surface of the end cover 10, and the welding current is continuously applied, so that the projection 5 is welded to the steel plate component 35.

When the outer diameter of the shaft portion 3 is significantly smaller than the inner diameter of the through hole 21, contact may not occur in this portion. In such a case, the guide pin 22 is used.
By making the end face of the shaft an inclined surface as shown by the chain double-dashed line, the shaft 3 is inclined and the above-mentioned contact is surely caused.

In the embodiment of FIG. 2, the movable member 14 is deformed, and the receiving member 17 of FIG. In order to smoothly advance and retreat the inside of the large-diameter portion 20, the conduction plate 18 has a circular cup-like shape that opens downward.

[0014]

According to the present invention, since the conductive member is installed in the back of the receiving hole of the component and the conductive contact is made between the component and the conductive member inside the electrode, the above space problem can be solved. . Since the energization by the contact as described above is achieved,
The detection current can always be conducted with high reliability.
Therefore, it is possible to prevent a hindrance to a downstream process due to lack of parts. The conductive member is composed of a pair of a movable member and a fixed member that receive contact with each other, a coil spring is interposed between both members, and both members are connected by a conductive wire. Since the reaction force of (3) strongly acts on the contact portion between the component and the movable member, good electrical conductivity is maintained in this portion, and it is extremely effective in increasing the reliability of detection. And the connection by the above-mentioned conducting wire also significantly contributes to the improvement of the detection reliability. That is, it may be difficult to establish conduction only by the coil springs due to the presence of lubricating oil or the like, but the installation of the conduction line enables the operation of component detection without such fear.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention.

FIG. 2 is a partial vertical sectional side view showing another embodiment.

FIG. 3 is a partial side view of a supply rod.

[Explanation of symbols]

 2 parts 21 receiving holes 14, 17, 18, 22 conducting member 17, 18 movable member 15 fixed member 16 coil spring 19 conducting wire

Claims (2)

[Claims] 1. A conductive member is installed in the back of the receiving hole of the component,
An electrode for projection welding or the like, characterized in that electrical contact for detecting a part is established by contacting the part with the conductive member. 2. The conductive member according to claim 1, wherein the conductive member is composed of a pair of a movable member and a fixed member that receive contact with a component, a coil spring is interposed between both members, and both members are connected by a conductive wire. Electrodes for projection welding etc. characterized by being connected.