JPH06277853A - Method and equipment for projection welding of flanged bolt or the like - Google Patents

Abstract

PURPOSE:To greatly secure welding strength at the time of fitting a part by allowing a movable electrode and a flange to serve as an external die and allowing a fixed electrode having a recessed part to serve as an internal die. CONSTITUTION:The recessed part 9 is provided on the upper surface of the fixed electrode 7, a storage hole 12 is bored on the movable electrode 11 and a magnet 13 is fixed on the inner part thereof. When a supply rod 15 and an air cylinder 14 are pushed up by an air cylinder 23, a shaft part 2 of a bolt 1 penetrates into the storage hole 12 and receives the attraction of the magnet 13. When the movable electrode 11 advances and a deposited projection 4 of the flange 3 is pressed upon a steel plate part 5, the steel plate part 5 is pressed in the recessed part 9 and deformed. When the movable electrode 11 is advanced while energizing is carried out between both electrodes 7 and 11, the deposited projection 4 is fused. At this time, the movable electrode 11 and the flange 3 serve as the external die and the fixed electrode 7 serves as the internal die and while the steel plate part 5 is drawn, projection welding is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention holds a bolt with a flange on a movable electrode, mounts a steel plate component as a counterpart member on a fixed electrode, and presses the flange against the steel plate component to perform projection welding. The present invention relates to a welding method and an apparatus therefor.

[0002]

2. Description of the Related Art FIG. 8 shows a case where a bolt is welded by a conventional technique, and 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 shown as the welding portion 6. In the figure, the surface of the flange 3 is located above the surface of the steel plate component 5 by a thickness t. On the other hand, a lower hole is made in the steel plate component 5 of FIG.
The projection welding of the upper surface of the steel plate and the lower surface of the steel plate component 5 is generally adopted.

[0003]

When another component is attached to the bolt 1 welded as described above by a nut, only the surface of the flange 3 is in close contact with the steel plate component 5, so that the welding is performed. The strength is remarkably low and therefore the mounting strength of the parts is insufficient. On the other hand, FIG.
In the case where the steel plate component 5 of FIG. 1 has a pilot hole and the shaft portion 2 is penetrated from the lower side of the figure to perform projection welding, a sufficient contact area between the component and the steel plate component can be secured, It is necessary to make a pilot hole in the steel plate part and to insert a bolt therein, which is disadvantageous for improving productivity.

[0004]

Means for Solving the Problem and Its Action The present invention is provided to solve the above-mentioned problems. Claim 1 holds a bolt with a flange or the like on a movable electrode, and a fixed electrode. In a type in which a steel plate component, which is a counterpart member, is placed on top and the flange is pressed against the steel plate component to perform projection welding, the movable electrode and the flange exposed on the surface serve as the male mold of the sheet metal press. Is a welding method characterized by performing projection welding while the fixed electrode having the concave portion plays the role of a female type and imparts draw forming to the steel plate component on the fixed electrode, and the steel plate component is welded as described above. Heating and press molding are performed simultaneously or in tandem. A second aspect of the present invention is the method according to the first aspect, characterized in that the welding protrusion is formed on the flange, and the welding protrusion is strongly pressed and the portion is melt-formed while being drawn. A third aspect of the present invention is the method according to the first aspect, wherein the corner portion of the flange is welded to the steel plate component, and the portion corresponding to the above-mentioned welding protrusion is the corner portion of the flange, and the ring-shaped melting is As it is done, drawing is done. According to a fourth aspect of the present invention, the movable electrode holds a bolt with a flange or the like, the steel plate component that is the counterpart member is placed on the fixed electrode, and the flange is pressed against the steel plate component to perform projection welding. A projection welding device such as a bolt with a flange, characterized in that the electrode is formed with a recess that is substantially the same as or slightly larger than the outer diameter of the flange, and such a dimensional relationship should be maintained. This makes it possible to perform so-called drawing. According to a fifth aspect of the present invention, in the welding apparatus according to the fourth aspect, 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 component. In this case, the surface of the flange and the surface of the steel plate component are located on the same plane to ensure a sufficient contact area of the component. The welding device is characterized in that a steel plate component is strongly sandwiched between the welding protrusion and the welding current density to the welding protrusion to an appropriate value. Claim 7 is, in claim 4,
A welding device characterized in that steel plate parts are strongly sandwiched between the corners of the recess and the corners of the flange during the welding transition period, and by such sandwiching, the welding current density to the welding protrusions is increased. To obtain an appropriate value and obtain a ring-shaped weld.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of FIGS. 1 to 4 will be described. This is for welding a bolt 1 having a welding projection on a flange as shown in FIG. 8 to a steel plate component 5.
The fixed electrode 7 is firmly fixed to the stationary member 8 (the insulating structure is not shown), and the recess 9 is provided on the upper surface thereof. Although not shown, since the flange 3 is circular, the recess 9 is also circular. Reference numeral 10 indicates the bottom surface of the recess 9, and the depth of the recess 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. A housing hole 12 into which the shaft portion 2 is inserted is formed in the movable electrode 11, and a magnet 13 is fixed to the inner portion thereof.

[0006] Explaining the means for making the bolt 1 reach the accommodation hole 12, the supply rod 15 which moves forward and backward by the air cylinder 14 is supported by the guide cylinder 16, and the tip of the supply rod 15 is positioned for parts. A hollow 17 is formed. An introduction pipe 18 is welded to the tip of the guide cylinder 16, and a supply hose 19 made of synthetic resin is welded to the introduction pipe 18.
Are connected, and the ends thereof are connected to a parts feeder (not shown). A magnet 20 for preventing displacement of the bolt 1 is embedded in the center of the recess 17, while an elongated passage groove 21 for allowing the shaft portion 2 to pass is formed in the introduction pipe 18. is there. The substrate 22 that integrally supports the guide cylinder 16 and the air cylinder 14 is connected to a piston rod 24 of an air cylinder 23 that vertically strokes. As an example of the dimensions of related parts, the diameter of the shaft portion 2 is 4 mm and the diameter of the flange 3 is 1.
0 mm, the thickness of the flange 3 is 1.0 mm, the thickness of the steel plate component 5 is 0.7 mm, and it is suitable to use a high hardness chrome copper alloy at least in the vicinity of the recess 9 of the fixed electrode 7. Furthermore, it is appropriate to select a steel material that is easy to press for the steel plate component 5.

The operation of the bolt 1 stopped in the recess 17 will be stopped by the operation of the air cylinder 14 so that the supply rod 15 advances and the bolt 1 is coaxial with the housing hole 12. It should be noted that there is such an interval that it can be stopped between the steel plate component 5 and the movable electrode 11. Next, when the supply rod 15 and the air cylinder 14 are pushed upward by the air cylinder 23, the shaft portion 2 of the bolt enters the accommodation hole 12 and receives the attraction force of the magnet 13 this time. When the supply rod 15 retracts in this state, the bolt 1 remains in the accommodation hole 12 as shown in the drawing. After that, when the movable electrode 11 advances and the welding projection 4 is pressed against the steel plate component 5, the steel plate component 5 is pushed into the recess 9 as shown in FIG.
It is strongly sandwiched between the bottom surface 10 and the bottom surface 10 and is deformed as shown in FIG. The modification of FIG. 2 is exaggerated for easy understanding. Next, when the movable electrode 11 further advances while electric current is applied between both electrodes, the welding protrusion 4 melts and becomes a state as shown in FIG. At this time,
The movable electrode 11 and the flange 3 play a male role, and the fixed electrode 7 having the concave portion 9 plays a female role, so that the steel plate component on the fixed electrode is subjected to drawing. FIG. 4 shows a state in which another component 25 is tightened with a nut 26 to the bolted steel plate component obtained as described above, and the component 25 is in close contact with both the flange 3 and the steel plate component 5 as shown. ing.

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

The embodiment of FIG. 7 is for a nut 29 having a flange 28, the operation of which is the same as that described above, so a detailed description is omitted.

The embodiment of FIGS. 9 and 10 uses a bolt similar to the bolt 1 of FIG. 5 so that the inner diameter of the recess 9 is approximately the same as or slightly larger than the outer diameter of the flange 3 as shown. Moreover, the depth of the recess is set to be extremely large as shown in the figure. By sandwiching the steel plate component 5 between the ring-shaped corner portion (the recessed portion 9 is circular although not shown in plan view) 30 and the corner portion of the flange 3,
Ring-shaped welding is performed while drawing is performed. Reference numeral 6 indicates this welded portion.

[0011]

[Effects] According to the present invention, a steel plate component is drawn by both electrodes by a principle like a sheet metal press, so that a predetermined welding form can be obtained during a welding stroke, which is extremely advantageous for improving productivity. Is. Since the flange is pressed into the steel plate component, the welding strength can be sufficiently high and there is no concern about the strength when mounting the component. When the steel plate component is provided with the welding protrusion, the welding protrusion is heated while pressing and deforming the steel plate component, whereby the draw forming is smoothly performed. When the corner portion of the flange is pressed against the steel plate component in place of the welding protrusion, a ring-shaped welding portion is obtained and the welding strength is high. Further, since it is not necessary to open a pilot hole as in the prior art, the step of inserting a bolt or the like into the pilot hole can be omitted, which is also extremely advantageous in improving productivity in this respect.

[Brief description of drawings]

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

FIG. 2 is a partial vertical cross-sectional side view showing a transitional period of deformation of a steel plate component.

FIG. 3 is a partial vertical cross-sectional side view showing a state in which press deformation has been completed.

FIG. 4 is a vertical sectional side view showing a mounting state of components.

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

6 is a partial vertical cross-sectional side view showing a concave portion of the fixed electrode in FIG.

FIG. 7 is a partial vertical cross-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 vertical sectional side view showing another embodiment.

FIG. 10 is a vertical cross-sectional side view showing a state in which FIG. 9 is pressurized.

[Explanation of symbols]

 11 Movable Electrode 3 Flange 1 Bolt 7 Fixed Electrode 5 Steel Plate Parts 9 Recess 10 Bottom 4 Welding Protrusion 30 Corner of Recess

Claims (7)

[Claims] 1. A movable electrode of a type in which a bolt with a flange or the like is held on a movable electrode, a steel plate component as a counterpart member is placed on the fixed electrode, and the flange is pressed against the steel plate component to perform projection welding. The electrode and the flange exposed on the surface play the role of a male die of the sheet metal press, and the fixed electrode having a recess plays the role of a female die.
A projection welding method for a flanged bolt or the like, characterized in that projection welding is performed while drawing forming is applied to a steel plate part on a fixed electrode. 2. The projection welding method according to claim 1, wherein the flange is provided with a welding projection. 3. The projection welding method according to claim 1, wherein a corner portion of the flange is welded to a steel plate component. 4. A type in which a movable electrode holds a bolt with a flange, a steel plate component as a counterpart member is placed on the fixed electrode, and the flange is pressed against the steel plate component to perform projection welding. A projection welding apparatus for a flanged bolt or the like, characterized in that the electrode is provided with a recess that is substantially the same as or slightly larger than the outer diameter of the flange. 5. The projection welding apparatus for a flanged bolt or the like according to claim 4, wherein the depth of the recess is set to be substantially the same as the total size of the thickness of the flange and the thickness of the steel plate component. 6. The projection welding apparatus according to claim 4, wherein the steel plate component is strongly sandwiched between the bottom surface of the recess and the welding projection during the welding transition period. 7. The projection welding apparatus for a flanged bolt or the like according to claim 4, wherein the steel plate component is strongly sandwiched between the corner of the recess and the corner of the flange during the welding transition period.