JPS5839016B2 - Box-shaped body flange forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a forming method for improving the strength of the flange portion of a box-shaped body made of sheet metal and the sealing effect of the joint surface.

More specifically, when forming a protrusion in the direction of the joint surface on the flange of a sheet metal box-like body, the protrusion is formed by pressing with a punch wider than the width of the protrusion on the joint surface, and the protrusion has a straight wall. It is molded reliably, and the strength of this part is improved by including the protrusion, and the straight wall and flat surface firmly and reliably tighten and hold the sealing member such as the backing material interposed between it and the other party. The present invention also relates to a molding method for obtaining a flange portion that can enhance the sealing effect.

When a box-shaped body made of sheet metal, such as the main body or lid of an oil case, is obtained by press-molding a sheet metal, a flange portion bent into an L shape toward the periphery is provided at the edge of the container-shaped box body. This flange portion is stacked on the mating surface of the other party with a sealing material such as a backing material interposed therebetween, and is tightened and connected with bolts or the like to be integrated with the other party.

The above conventional means remove flat dust from the entire circumference of the flange.
It is difficult to obtain parallelism, and it is difficult to obtain complete tight bonding with the mating surface.

For this reason, a backing material, etc. is interposed and tightened, but since the flatness and parallelism of the flange part itself cannot be achieved with high precision, the tightening force of the backing material will also differ at each location.
It is difficult to achieve a perfect seal, and internal oil, etc. often leaks out.

Furthermore, since the flange portion is simply formed flat, the strength of the joint surface is low, and although the puffing material is interposed as described above, it is difficult to expect sufficient effects as described above.

The present inventors have devised the present invention in order to effectively solve the above-mentioned problem of joining a sheet metal box-like body using a flange portion.

The object of the present invention is to form a protrusion protruding in the direction of the joint surface on the flange portion of a box-shaped body made of sheet metal by press-forming with a punch having a width larger than the width of the die for forming the projection in the direction of the joint surface. The present invention provides a molding method that achieves this.

Therefore, the object of the present invention is to press-form in the protruding direction with a punch wider than the protrusion to be formed on the joint surface, so that the protrusion is pushed out in the direction of the die by forging, and the flat dust on the joint surface of the protrusion is removed. A molding method that can securely hold and form a straight wall with high precision, and that the straight wall and flat joint surface firmly bite and bite into the sealing member, resulting in a joint with a high sealing effect. I will provide a.

Another object of the present invention is that, as mentioned above, since the forging extrusion is used, the structure between the protrusion and the flange can be made denser, and the strength of the joint and the surrounding area can be improved. We aim to improve the lifespan and durability of oil cases, etc., including screw joints, etc., and to improve the above by simple means.
To provide a molding method as contemplated by the molding method.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view of the main part in the molded state, FIG. 2 is a perspective view of the molded box, and FIG. 3 is a longitudinal sectional view of the main part in the joined state.

In Fig. 1, 1 is a box body, which includes a main body 2 which is formed by drawing a pressed steel plate or the like, and an integrated body 2 which is bent and extended outward from the open end in an L-shape so as to surround the periphery. It consists of a flange part 3.

10 is a die which is a lower mold, and a main body 2 is in the center of the die 10.
A holder part 11 is formed to fit into and hold the holder part 11, and a molded part 12 is formed around the holder part 11 with a step so as to surround it.The upper surface 13 of the molded part 12 is formed flat, and the flange part It faces the lower surface 4 of 3.

A molding groove 14 having a predetermined depth is provided on the upper surface 13 of the molding part 12 so as to surround the molding part 12.
5.degree. 15 is provided at right angles to the horizontal and flat bottom 16.

On the other hand, a pressurizing punch 20 is provided above the forming groove 14 of the forming part 12, and the forming part 21 of this punch 20 is provided with a right angle part and flatness maintained with high precision. The width W is set larger than the width W1 of the forming groove 14.

In the above process, the box 1 is set in the die 10, and the flange part 3 is mounted and set on the upper surface 13 of the molding part 12.

Then, by applying pressure with the punch 20, the lower surface 4 of this portion of the flange portion 3 is caused to protrude downward, and the upper surface 5 is recessed.

In this way, the protrusion 6 is formed so as to surround the lower surface of the flange portion 3.

The four corner parts 6a of the projection 6 are formed into a circular shape surrounding the mounting holes 6c, and the molding is carried out under the same conditions as above, and the other parts 6b, that is, the four sides of the flange part, are It is provided in a straight line with a predetermined width.

The protrusion 6 obtained above is formed by the punch 20 because the width of the forming part 21 of the punch 20 is larger than the forming groove 14 on the - die side.
The pressurization is similar to forging press, and the groove 14 portion is pushed out and plastically deformed.

Since the area of the forge extrusion by the punch 20 is larger than the width of the groove 14, the extruded structure is formed on the straight wall 15.1 of the groove 14.
5, the straight walls 7, 1 are formed, and the bottom 8 is formed flat, parallel and flat.
A recess 9 is formed on the upper surface.

In addition, since the width of the punch 20 is larger than the groove 14, problems such as shearing of the tissue do not occur in the concave and protrusive formed portion, and the formed portion 21 of the punch 20 and each right angle portion of the groove 14 are misaligned, and the formed portion 21
Since the right angles of the grooves 21 are bent outward from the right angle portions of the grooves 21, the structure of this portion is densified by the forging action, and the strength of this portion is increased.

As described above, the portion including the protrusion 6 formed on the lower surface of the flange portion 3 is used as a joining surface, and this is overlapped and joined to the upper surface 32 of the flange portion 31 of the other party 30.

For this joining, a backing material 40 is interposed between the lower surface 4 of the flange portion 3 and the upper surface 32 of the flange portion 31, and the bolt 41 is inserted into the screw hole 33 of the mating member 30 through the mounting hole 6C.
and screwed together with the washer 42.

As a result, the flange portions 3° 31 are tightened in the direction toward each other, but at this time, the protrusion 6 bites into the backing material 40, and this bite occurs at the straight wall 7, and the flat bottom surface 8 of the protrusion A bite seal is ensured between the right angle part and the right angle part.

Although the illustrated embodiment has been described above, the box body does not have to be square as in the illustrated example, and the flange portion is cut off toward the outer end, but it may have a structure in which the end portion is bent upward or downward. Further, the protrusion may be provided partially.

As is clear from the above, according to the present invention, the protrusions are formed using a punch that is wider than the protrusions formed on the joint surface of the flange of the box-shaped body, so the protrusions are formed by the same method as press forming.
By making the structure of the molded part more dense, it is possible to significantly improve the strength of this part.

Also, as a result, the protrusion has a straight wall and a flat bottom, which firmly bites into the backing material interposed between the protrusion and the other flange, and together with the flat bottom, it has a sealing effect. This will significantly increase the

Furthermore, the above can be achieved by simply increasing the width of the punch relative to the molding groove of the die, and the above can be achieved with simple means and operations, which is extremely useful for the joining structure of box-shaped bodies that are joined and integrated. It is.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; Fig. 1 is a longitudinal sectional view of the main part in a molded state, Fig. 2 is a perspective view of the box-shaped body, and Fig. 3 is a longitudinal sectional view of the joint part. . In the drawings, 1 is a box-shaped body, 3 is a flange, 10 is a die, and 20 is a punch. 6 is sudden

Claims (1)

[Claims] 1 In a method of forming protrusions in the direction of the joint surface on the flange of a box-shaped body made of sheet metal, the width of the punch is set larger than the width of the die recess on the joint surface side, and the pressure of the punch is applied to the flange. A method for forming a flange portion of a box-shaped body, characterized in that the portion is forged and extruded toward the concave side of the die.