JP2784988B2 - Electrode for projection welding - Google Patents

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, and is used in a field in which pressure is applied while holding a part.

[0002]

2. Description of the Related Art A part is inserted into an insertion hole opened at an end of an electrode, and then the electrode is advanced toward a counterpart member, or the counterpart member is moved toward the electrode, and the part is projection-welded to the counterpart member. It is known to do. As a method of holding parts in the insertion hole of the electrode,
An elastic body such as rubber is attached to the inner surface of the insertion hole, and the component is held using this elasticity. Further, in order to press the component against the counterpart member, the component is sandwiched and pressed by a method such as a chuck mechanism.

[0003]

In the case of the above-described component holding by the elastic body, the durability of the elastic material cannot be sufficiently obtained, so that the component holding function can be quickly performed due to wear of the elastic body. The parts will drop, and the holding position will be out of order. Furthermore, in the conventional one, the component is pressed against the counterpart member so as to be sandwiched between the components,
It was not possible to obtain sufficient pressing force, which caused welding failure.

[0004]

[Means for Solving the Problems and Their Functions] The present invention has been proposed to solve the above-mentioned problems.
A component insertion hole is provided at the end of the electrode, and an energizing and pressing member made of a non-magnetic material for energizing and applying power to the component is located at the back of the hole. The magnet is provided with a magnet, and the component that enters the insertion hole is in contact with the current-pressing member and receives the attractive force of the magnet. When the component is pressed against the counterpart member, the component is pressed with a sufficient force by the energizing pressing member, and at the same time, high reliability is obtained in terms of energization.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the embodiment shown in FIGS. 1 and 2 will be described. A component 1 is a projection bolt made of an iron material, and includes a shaft portion 2, a flange 3, and a welding formed on the flange. Are formed. The electrode according to the present invention is realized here as a movable electrode 5, on which a fixed electrode 6 paired with the movable electrode 5 is arranged coaxially, on which a mating member 7 to which the bolt 1 is to be welded, that is, a steel plate component is placed. Have been. The movable electrode 5 is connected to a working rod 8 extending from an air cylinder (not shown).

The movable electrode 5 has a housing 9 and a cap 10 which are integrated by a screw 11, and a permanent magnet 12 is arranged in the housing 9. This magnet is housed in a container 13 made of a non-magnetic material such as stainless steel,
It is sealed with a lid plate 14 made of a similar material. Then, the outside thereof is made of an insulating container 15 made of synthetic resin and an insulating lid plate 1.
It is surrounded by 6. The housing 9 and the cap 10
Is made of a copper alloy.

The electrode 5 has a circular cross section. Similarly, a circular energizing member 17 is firmly fixed in a state of being sandwiched between the accommodating portion 9 and the cap portion 10.
The member 17 has abrasion resistance and good electrical conductivity, such as chromium copper, and is made of a non-magnetic material. In addition, the thickness of the bolt 1 is set to be sufficiently large as shown in FIG. An insertion hole 18 opened at the end of the cap portion 10 communicates with the energizing and pressing member 17, and an insulating tube 19 made of synthetic resin.
Are fitted, and the inside thereof is an insertion hole 18. As the overall arrangement, an energizing and pressing member 17 is installed at the back of the insertion hole 18, and the magnet 12 is further installed at the back, where the back is from bottom to top in FIG. That is, the direction opposite to the direction in which the electrode 5 advances is the back side.

Means for inserting the bolt 1 into the accommodation hole 18 may be performed manually by an operator or by an automatic machine, but the latter case is shown here as an example. That is, the piston rod 2 of the air cylinder 20 that moves up and down
1, an air cylinder 23 is fixed on the substrate 22 so as to advance and retreat in the horizontal direction.
The holding member 25 is fixed to 4. A step 26 is formed in the holding member 25, and the bolt 1 is held upright and held by a magnet 27 embedded therein as shown in the figure. Although not shown, there is also a method in which a groove in which the raised portion 4 is fitted into the step portion 26 is opened to the left, and a magnet is buried in the bottom thereof. By doing so, the flange 3
Is supported in a state of good stability. A component supply pipe 28 is opened directly above the step portion 26.
Reference numeral 8 denotes a bracket extending from a parts feeder (not shown).
9 is erected as shown in the figure, and the component supply pipe 28 is welded. The component supply pipe 28 is provided with a notch 30 through which the shaft 2 of the bolt 1 passes.

FIG. 2 shows the relationship between the magnetic flux lines between the magnet 12 and the bolt 1. The polarities of S and N of the magnet 12 are set up and down as shown in FIG. Since the member is made of a non-magnetic material as described above, since the magnetic flux lines 31 pass in the axial direction of the bolt 1 as shown in the figure, the bolt 1 is pressed against the energizing and pressing member 17 and held. It is.

FIG. 1 shows a state in which the bolt 1 is held in the insertion hole 18 and the next bolt 1 is on standby on the step portion 26. Description will be made assuming that there is no bolt 1. When the holding member 25 advances leftward by the air cylinder 23, the bolt 1
Also moves upright, and this advance stops at a position coaxial with the insertion hole 18. After that, air cylinder 2
When the substrate 22 is raised by 0, the shaft portion 2 enters the insertion hole 18 and stops at a position where the upper end of the shaft portion 2 abuts the energization pressing member 17. When the holding member 25 is retracted rightward from that state, the holding member 25 returns to the original position while the bolt 1 remains in the insertion hole 18.

The bolt 1 in the insertion hole 18 receives the upward suction force in FIG. 1 by the action shown in FIG.
In this state, the movable electrode 5 advances downward, and is stopped at a position where the raised portion 4 is pressed against the counterpart member 7. When the energization is subsequently performed, the raised portion 4 is melted and welding is completed. During this energization, the magnet 12 is surrounded by the insulating container 15 and the insulating lid plate 16 and is not affected by the energization. The current flows from the housing 9 to the bolt 1 via the energizing and pressing member 17, and the above-described welding is performed.

In the embodiment shown in FIG. 3, only the energizing and pressing member 17 is deformed, and a thick portion 32 and a guide cylinder 33 extending therefrom are provided. The forces are as described above.

The embodiment shown in FIG. 4 is also a modification of the energizing and pressing member. In the previous embodiment, the energizing and pressing member was installed as a separate component.
7 is formed, in other words, the insertion hole 18 is a bottomed hole.

In the embodiment shown in FIG. 5, the magnet is changed to an electromagnet, and an exciting coil 35 is arranged around an iron core 34.

In the illustrated embodiment, the movable electrode 5 extends downward, but the movable electrode 5 extends upward or sideways without departing from the spirit of the present invention. Alternatively, the internal structure of the movable electrode 5 may be moved to the fixed electrode 6 side.

[0016]

According to the present invention, since the magnetic attraction acts on the component in the insertion hole from the back of the electrode, the component is attracted toward the back of the insertion hole.
The components do not fall or get out of order even if vibrations occur due to the direction of the electrodes or any cause. Since the attractive force of the magnet is used, the elastic body does not come into contact with the components as in the related art, and the elastic body does not wear. An energizing pressurizing member for energizing and pressurizing is installed at the back of the insertion hole, so the component is pressed against the opposing member while contacting the energizing pressurizing member, and the energization from the energizing pressurizing member to the component is ensured. In addition, the pressure contact between the component and the counterpart member is firmly performed, so that the welded state is always uniformly obtained and the welding quality is remarkably improved.

[Brief description of the drawings]

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

FIG. 2 is a side view showing a state of magnetic flux lines.

FIG. 3 is a partial longitudinal sectional side view showing another embodiment.

FIG. 4 is a partial vertical sectional side view showing another embodiment.

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

[Explanation of symbols]

 5 Electrode 1 Component 18 Insertion hole 17 Current applying member 12, 34 Magnet

Claims (1)

(57) [Claims] An insertion hole for a component is provided at an end of an electrode, and a current-carrying member made of a non-magnetic material for energizing and pressing the component is disposed at a depth of the insertion hole. An electrode for projection welding, wherein a magnet for applying an attractive force to a part is arranged.