JP3331404B2 - Projection welding method and apparatus for bolt with flange - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which a bolt with a flange is held on a movable electrode, a steel plate part as a mating member is placed on a fixed electrode, and the flange is pressed against the steel plate part to perform projection welding. And to a welding method and an apparatus therefor.

[0002]

2. Description of the Related Art FIG. 8 shows a case where welding is performed by a conventional technique. A bolt 1 is composed of a shaft portion 2, a flange 3, and a welding projection 4 shown in FIG. In addition,
In FIG. 8, since the welding projection is welded to the steel plate component 5, it is illustrated as a welding portion 6. In the figure, the surface of the flange 3 is at a position floating by the thickness t from the surface of the steel plate part 5. On the other hand, a pilot hole is made in the steel plate part 5 of FIG.
And the lower surface of the steel plate component 5 are projection-welded.

[0003]

In the case where another part is attached to the bolt 1 to which such welding has been made by using a nut, only the surface of the flange 3 is in close contact with the steel plate part 5. The strength is significantly lower and therefore the mounting strength of the component is insufficient. On the other hand, FIG.
In the case where a hole is drilled in the steel plate part 5 and projection welding is performed by penetrating the shaft part 2 from the lower side of the figure, a sufficient contact area between the part and the steel plate part can be secured. It is necessary to make a pilot hole in a steel plate part and insert a bolt there, which is disadvantageous for improving productivity.

[0004]

SUMMARY OF THE INVENTION The present invention has been provided to solve the above-mentioned problems. A first aspect of the present invention is to hold a bolt with a flange on a movable electrode, The movable electrode and the flange exposed on the surface of the movable electrode and the flange exposed on the surface play the role of the male type of the sheet metal press in the type in which the steel plate part as the counterpart member is placed on the The fixed electrode having the concave portion plays the role of a female mold, and the flanged bolt is provided while drawing and forming the steel plate part on the fixed electrode.
The a projection welding method of flanged bolts and performing projection welding to the steel sheet part, the steel sheet part is welded heat and the press molding is carried out before and after the same time or phase, as described above.

According to a second aspect of the present invention, in the first aspect, a welding projection is formed on the flange. The welding projection is strongly pressed, and the portion is melted to perform drawing forming. is there.

A third aspect of the present invention is the method according to the first aspect, characterized in that the corner portion of the flange is welded to the steel plate part. Is drawn while melting is performed.

According to a fourth aspect of the present invention, the movable electrode is provided with a flanged bolt, a steel plate part as a counterpart member is placed on the fixed electrode, and the flange is pressed against the steel plate part to perform projection welding. , Movable electrode and its
The flange exposed on the surface of the
It was established as the substantially equal to or slightly larger recess than is the male and the outer diameter of the flange to the fixed electrode
This is a projection welding apparatus for a bolt with a flange, which is set up so as to serve as a female mold for a mold. By setting such a dimensional relationship, so-called drawing molding is made possible.

A fifth aspect of the present invention is the welding apparatus according to the fourth aspect, wherein the depth of the recess is set to be substantially the same as the total dimension of the thickness of the flange and the thickness of the steel plate part. When the molding is performed, the surface of the flange and the surface of the steel plate part are located on the same plane, so that the contact area of the part is sufficiently ensured.

According to a sixth aspect of the present invention, there is provided a welding apparatus according to the fourth aspect, wherein a steel plate part is strongly sandwiched between the bottom surface of the concave portion and the welding projection in a transition period of welding. The welding current density to the welding projection is adjusted to an appropriate value by the attachment.

According to a seventh aspect of the present invention, there is provided a welding apparatus according to the fourth aspect, wherein a steel plate part is strongly sandwiched between a corner portion of the concave portion and a corner portion of the flange in a transition period of welding. With such pinching, the welding current density on the welding protrusion is adjusted to an appropriate value, and ring-shaped welding is obtained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment of FIGS. 1 to 4 will be described .
G is welded to the steel plate part 5. The fixed electrode 7 is firmly fixed to the stationary member 8 (the insulating structure is not shown), and a concave portion 9 is provided on the upper surface thereof.
Although not shown, since the flange 3 is circular, the concave portion 9 is also circular. Reference numeral 10 indicates the bottom surface of the concave portion 9, and the depth of the concave portion 9 is substantially the same as the total dimension of the thickness of the flange 3 and the thickness of the steel plate component 5. An accommodating hole 12 into which the shaft portion 2 enters is formed in the movable electrode 11, and a magnet 13 is fixed in a deep portion thereof.

The means for causing the bolt 1 to reach the accommodation hole 12 will be described. A supply rod 15 which advances and retreats in the left-right direction is supported by a guide cylinder 16 by an air cylinder 14. A recess 17 to be formed is formed. An introduction pipe 18 is welded to the end of the guide cylinder 16 and a supply hose 19 made of synthetic resin is attached thereto.
And its end is connected to a parts feeder (not shown). A magnet 20 for preventing displacement of the bolt 1 is buried in the center of the recess 17, while an elongated passage groove 21 for passing the shaft 2 is formed in the introduction pipe 18. is there. A substrate 22 that supports the guide cylinder 16 and the air cylinder 14 integrally is connected to a piston rod 24 of an air cylinder 23 that moves vertically.

Incidentally, the dimensions of the relevant portions are illustrated by way of example. The diameter of the shaft 2 is 4 mm, the diameter of the flange 3 is 10 mm, the thickness of the flange 3 is 1.0 mm, and the thickness of the steel plate part 5 is 0.7
mm, and at least the concave portion 9 of the electrode, particularly the fixed electrode 7.
It is appropriate to use a high-hardness chromium copper alloy in the vicinity, and it is appropriate to select a steel material that is easy to press work for the steel plate part 5.

In the following, the operation will be described. The bolt 1 stopped in the depression 17 is stopped at a position where the supply rod 15 is advanced by the operation of the air cylinder 14 and the bolt 1 becomes coaxial with the accommodation hole 12. In this case, a space that can be stopped is provided between the steel plate part 5 and the movable electrode 11. Next, when the supply rod 15 and the air cylinder 14 are pushed up by the air cylinder 23, the shaft portion 2 of the bolt enters the accommodation hole 12, and this time receives the attraction force of the magnet 13. When the supply rod 15 retreats in this state, the bolt 1 remains in the accommodation hole 12 as shown.

Thereafter, when the movable electrode 11 advances and the welding projection 4 is pressed against the steel plate part 5, the steel plate part 5 is pushed into the recess 9 as shown in FIG. 10, and is deformed as shown in FIG. It should be noted that the modification in FIG. 2 is exaggerated for easy understanding. Next, when the movable electrode 11 further advances while energization is performed between the two electrodes, the welding projections 4 are melted into a state as shown in FIG. At this time, the movable electrode 11 and the flange 3 play a role of a male type, and the fixed electrode 7 having the concave portion 9 plays a role of a female type.

FIG. 4 shows a state in which another part 25 is fastened to the bolted steel plate part obtained as described above with a nut 26. As shown in the figure, the part 25 includes both the flange 3 and the steel plate part 5. Closely adhered to.

Referring to the embodiment shown in FIGS. 5 and 6, this will be described in the case where the concave portion 9 of the fixed electrode 7 has a spherical shape and the flange 3 of the bolt 1 is also provided with a spherical convex portion 27. FIG. 5 shows a state where welding and drawing are completed. In this case, there is only one welded portion at the center as shown.

The embodiment shown in FIG. 7 is a case of a nut 29 having a flange 28, and its operation is the same as that described above, so that the detailed description is omitted.

The embodiment of FIGS. 9 and 10 is similar to the bolt 1 of FIG. 5 except that the inner diameter of the recess 9 is substantially equal to or slightly larger than the outer diameter of the flange 3 as shown. In addition, the depth of the concave portion is set to be extremely large as shown in the figure. Since the steel plate part 5 is sandwiched between the ring-shaped corner portion (the concave portion 9 is not shown but a circular shape, not shown) and the corner portion of the flange 3,
Ring-shaped welding is performed while drawing is performed. Reference numeral 6 indicates this welded portion.

[0020]

According to the present invention, a draw-forming process is applied to a steel plate part by the use of both electrodes in the same manner as a sheet metal press, so that a predetermined welding form can be obtained during a welding stroke, which is extremely advantageous for improving productivity. It is. Since the flange is in a state pushed into the steel sheet part, the welding strength can be ensured sufficiently large, the parts during the component mounting flange
Close contact with both steel and steel plate parts, worries about mounting strength of parts
There is no. When the welding projection is provided on the steel plate component, the welding projection is heated while pressing and deforming the steel plate component, so that the drawing can be smoothly performed. When the corner of the flange is pressed against the steel plate part instead of this welding projection,
A ring-shaped welded portion is obtained, resulting in high welding strength.
Furthermore, since there is no need to drill a pilot hole unlike the prior art, a step of inserting a bolt or the like into the pilot hole can be omitted, and this is also extremely advantageous in improving productivity.

[Brief description of the drawings]

FIG. 1 is a side view of the entire apparatus.

FIG. 2 is a partial longitudinal sectional side view showing a transition period of deformation of a steel plate part.

FIG. 3 is a partial vertical cross-sectional side view showing a state where press deformation is completed.

FIG. 4 is a vertical cross-sectional side view showing a mounted state of components.

FIG. 5 is a partial vertical cross-sectional side view showing a state where press deformation in another embodiment is completed.

FIG. 6 is a partial vertical sectional side view showing a recess of a fixed electrode in FIG. 5;

FIG. 7 is a partial longitudinal sectional side view of a movable electrode according to another embodiment.

FIG. 8 is a side view showing a conventional technique.

FIG. 9 is a longitudinal sectional side view showing another embodiment.

FIG. 10 is a longitudinal sectional side view showing a state where the one in FIG. 9 is pressurized.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Movable electrode 3 Flange 1 Bolt 7 Fixed electrode 5 Steel plate part 9 Concave 10 Bottom 4 Welding protrusion 30 Corner of concave

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23K 11/14 B23K 11/30 B21D 24/16

Claims (7)

(57) [Claims] 1. A method in which a bolt with a flange is held on a movable electrode, a steel plate part as a counterpart member is placed on a fixed electrode, and the flange is pressed against the steel plate part to perform projection welding. And the flange exposed on its surface serve as a male mold of a sheet metal press, and the fixed electrode having a concave portion serves as a female mold,
Flange while drawing on steel plate parts on fixed electrode
A projection welding method for a bolt with a flange, wherein the bolt with a bolt is subjected to projection welding to a steel plate part . 2. The projection welding method for a bolt with a flange according to claim 1, wherein a welding projection is formed on the flange. 3. The projection welding method for a bolt with a flange according to claim 1, wherein a corner portion of the flange is welded to the steel plate part. 4. hold the flanged bolt to the movable electrode, by placing the steel sheet part is a thrust bearing on the fixed electrode, in what form performing projection welding against the flange to the steel sheet part, the movable electrode And on its surface
Exposed flange as male-type
Installed, substantially the same or slightly larger recess than the outer diameter of the flange against the said male the fixed electrode
A projection welding apparatus for a bolt with a flange, which is installed to serve as a female mold . 5. The projection welding apparatus for a bolt with a flange according to claim 4, wherein the depth of the recess is set to be substantially the same as the sum of the thickness of the flange and the thickness of the steel plate part. 6. The projection welding apparatus for a bolt with a flange according to claim 4, wherein a steel plate part is strongly sandwiched between the bottom surface of the concave portion and the welding projection during a welding transition period. 7. The projection welding apparatus for a bolt with a flange according to claim 4, wherein a steel plate part is strongly sandwiched between a corner of the concave portion and a corner of the flange in a transition period of welding.