JPS58212818A - Formation of t-pipe - Google Patents

Abstract

PURPOSE:To form a T-pipe, having an improved reliability in strength, in low material cost, by forming an upper part of a T-pipe having a branched pipe part, and joining a circular-arcuate lower part of the T-pipe, formed separately, to the upper part. CONSTITUTION:A local part 17 having the increased thickness of a blank plate 1A is heated, and a primary hole 18 is drilled in the part 17. Next, an upper part 24 of a T-pipe having a branched pipe part 24a is formed by loading a working force 22 to perform a bending and a burring of the hole 18 in a hot state by using a die 19 and a bending-and-burring forming device equipped with a punch 20. Next, a blank same material as that of the upper part 24 used to form a lower part 25 of the T-pipe by a press die, and an edge preparation of the semi-circular periphery of the upper part 24 is performed after trimming it. An edge preparation of the lower part 25 is also performed in the same manner, and then, the upper and lower parts 24, 25 of the T-pipe are welded together at a welding part 26 to manufacture a T-pipe constituted of a mother pipe part provided with a branch pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a branch pipe, and in particular to a method for forming a branch pipe aimed at reducing material costs and improving reliability in terms of strength.

First, what is the conventional method of forming branch pipes? explain.

FIG. 1 is a schematic cross-sectional view showing a conventional purling forming apparatus used for carrying out a branch pipe forming method and a main pipe formed by the apparatus, and FIG. 2 is a conventional purling forming apparatus according to FIG. 1. FIG. 2 is a perspective view showing a branch pipe manufactured by the branch pipe forming method of FIG.

In FIG. 1, i is a main pipe with all pilot holes drilled, 6 is a main pipe fixing clamp for fixing both ends of the main pipe l, and 5 is a paring jig.

First, both ends of the main pipe 1 having prepared pilot holes are set using the main pipe fixing clamps 6. When the paring jig 5 is inserted into the main pipe 1 and pulled out from the prepared hole by applying a processing force 7 to the paring jig 5, the purling molded part 4 is formed and the edge of the prepared hole is formed. The part becomes the purling tip part 8. Then, by joining the branch pipe 2 to this burring tip 8 by welding, a branch pipe having the required height is manufactured.

The branch pipe manufactured in this manner is subjected to large tensile strain in the circumferential direction of the burring tip 8 during purling forming, and the plate thickness is greatly reduced. Also, the purling height is 9
If the diameter of the prepared hole is made smaller in order to increase the diameter, cracks will occur in the paring tip 8, resulting in a defective product. In order to prevent this, as mentioned above, in order to secure the necessary height, the branch pipe 2 must be welded. Since the branch pipe is located near the position where it exerts a large effect, there was a problem with the strength and reliability of the branch pipe.

On the other hand, in order to prevent cracks from occurring in the purling tip 8 during the purling forming, a thick main tube 1
There was also a problem in that the cost of materials increased when using .

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for forming a branch pipe, which eliminates the drawbacks of the prior art described above and can form a branch pipe with low material cost and improved reliability in terms of strength. It is something.

The structure of the present invention is such that after drilling a pilot hole in the locally thickened portion of a blank plate that has locally thickened, the blank plate is bent into an arc shape, and at the same time, the hole edge of the pilot hole is subjected to a purling process. In this method, a branch pipe upper part having a branch pipe part is formed by forming a branch pipe upper part, and a branch pipe is formed by joining this branch pipe upper part to a separately molded arc-shaped branch pipe lower part.

The present invention will be explained below with reference to Examples.

Figures 3 to 6 are for explaining a method of forming a branch pipe according to an embodiment of the present invention, and Figure 3 is a swaging processing device for locally increasing the thickness of the whole blank plate. FIG. 4 is a perspective view showing a blank metal plate with pilot holes drilled in the locally thickened portion, and FIG. 5 is a perspective view showing the blank plate according to FIG. 4 when bent. At the same time, FIG. 6 is a schematic cross-sectional view showing a bending and purling forming apparatus used for purling the hole edge of the prepared hole. FIG. 3 is a perspective view showing a branch pipe formed by welding an upper part of the branch pipe and a lower part of the branch pipe formed separately.

Forming of the branch pipe consists of the first to fourth steps described in detail below.

The first step is swaging, which locally increases the thickness of the blank. This first construction pillar will be explained using FIG. In FIG. 3, IA is a blank plate with a uniform thickness, and 10 is a cooling pipe (not shown) disposed above and below this blank plate IA.
The heating coil 13 is a transformer for the heating coil 10, and this transformer 13 is connected to a high frequency oscillator (not shown). 11 is a hydraulic cylinder capable of applying a swaging force 15'f to the blank plate IA at a constant speed, and 12 is a fixed pressure receiving plate.

The blank plate IA is moved into a hydraulic cylinder 11. Chucking is performed using a clamp (not shown) provided on the fixed pressure receiving plate 12. At the part of the blank plate IA where local thickening is to be performed (local thickening part 17),
Set two 1° heating coils from below. A high frequency oscillator (not shown) is output to start heating the portion of the blank IA. A predetermined processing temperature (for example, 900r) is narrowed down to F. A swaging force 15 is applied by the hydraulic cylinder 11, and in this state it is heated:
By moving the 1-ile IO in the moving direction 16, a locally thickened portion 17 having a uniform plate thickness can be obtained. The thickness increase rate of the local thickening portion 17 is set in order to suppress the thinning rate that occurs during the purling process in the third step, which will be described later, to 0% compared to the initial thickness of the blank plate IA. It is of the required size.

In the second step, the locally thickened portion 17 of the blank plate IA, which has been locally thickened in the first step, may be subjected to paring, plastic working (shearing), etc. in the third step, which will be described later.

In the next third step, a pilot hole 1 is inserted into the locally thickened portion 17 according to FIG.
In this step, the blank plate IA't having the hole 8 drilled therein is bent into a semicircular arc shape, and at the same time, the hole edge of the prepared hole 18 is subjected to the purling process. This third step will be explained using FIG. 5.

In FIG. 5, 19 is a semi-circular die, 20 is a punch, and 21 is a wrinkle presser for fixing both ends of the blank plate IA placed on the die 19.

Compared to the initial plate thickness of 26.2rtm, it can be suppressed to 0%, so the swaging force can be reduced to 15' (i-230t
Swap processing is performed as f.

In the second step, a pilot hole 18 of 2001 is bored in the locally thickened portion 17.

In the third step, a die 19 with a radius of curvature of 254w5 is used.
and a punch 20 with a punch diameter of 354 m.

Processing temperature is 90℃ using a no-bending purring molding device.
During hot working at 0C, a working force 22 of approximately 65 tr is applied to perform bending and purling of the prepared hole 18 (in this case, cold working may also be performed, and the working force of cold working is approximately 4301 f). ), the branch pipe upper part 24 having the desired branch pipe portion 24a is formed. In this molding, the thickness of the purling tip 24b was approximately 26.2 m, which was approximately the same as the thickness of the blank plate IA.

In the fourth process, the length is 900m, the width is 800m, and the board thickness is 26m.
The 2M raw plate C# quality is the same as the tree root of the upper part of the branch pipe 24).
In use, the lower part of the branch pipe 25 is removed by a press or (not shown).
The molded product is used as a semi-conductor.

The total circumference of the semicircular arc of the branch pipe upper part 24 is 800 m.
After trimming, beveling is performed.

The lower part of the branch pipe 25 is also beveled in the same manner. By welding at the upper and lower 24.25i welding parts 26 of the branch pipe, it is possible to manufacture a branch pipe in which the main pipe part with a nominal diameter of 500 A can serve as a branch pipe part of 400 A.

In addition, in this embodiment, the local thickness increase of the blank plate IA was carried out by the swaging process that fully utilizes local heating, but the method of local thickness increase is not limited to the swaging process. As shown in the figure, partial rolling may be used.

FIG. 7 is a schematic view showing the entire mold rolling apparatus used for locally increasing the thickness of the blank plate 2 in a branch pipe forming method according to another embodiment of the present invention.

In this FIG. 7, 27 is a mold roll, and IA is a blank plate, and this blank plate IAffi is partially rolled by the mold roll 27 from above and below to locally increase the thickness (
17 is a locally thickened area). However, in this method, the raw plate IA
Because of the discontinuous velocity distribution within the steel, it is difficult to increase the thickness by more than 40%.

Furthermore, in this embodiment, the local thickness of the blank plate IA is increased in the first step, and the locally thickened portion 17 of the blank plate IA is performed in the second process.
However, a drawing process is introduced between the first and second steps, and the lower type processed part is drawn into a cup shape in advance, and a pilot hole is formed in the bottom of the cup. 18 has the advantage that the branch pipe portion 24a can be lengthened by the aperture height.

According to the embodiment described above, compared to conventional products that use thick-walled main pipes to ensure reliability in terms of strength, approximately 20%
% of material costs can be reduced. Furthermore, compared to conventional products in which branch pipes are welded, the welded part 26 is moved away from the joint between the branch pipe part 24a and the main pipe part, which has the effect of improving reliability in terms of strength of the branch pipe. .

As described above in detail, according to the present invention, after drilling a pilot hole in the locally thickened portion of a blank plate, the blank plate is bent into an arc shape, and at the same time, The upper part of the branch pipe having the branch pipe part is formed by burring the edge of the hole, and the upper part of the branch pipe is joined to the lower part of the arc-shaped branch pipe formed separately to form the branch pipe. As a result, it is possible to provide a method for forming a branch pipe, which is capable of forming a branch pipe with low material cost and improved reliability in terms of strength.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a conventional purling forming apparatus used for carrying out a branch pipe forming method and a main pipe formed by the apparatus, and FIG. 2 is a conventional purling forming apparatus according to FIG. 1. 3 to 6 are perspective views showing a branch pipe manufactured by the branch pipe forming method, and are for explaining the branch pipe forming method according to an embodiment of the present invention. Figure 3 is a perspective view showing the swaging processing device and the raw plate together to locally increase the thickness of the entire blank, and Figure 4 is a perspective view showing the entire blank with pilot holes drilled in the local thickened areas. 5 is a schematic sectional view showing a bending and burring forming apparatus used for bending the blank sheet metal according to FIG. 4 and simultaneously burring the hole edge of the prepared hole, and FIG. FIG. 7 is a perspective view showing a branch pipe formed by welding the upper part of the branch pipe formed by the bending and purring forming apparatus shown in FIG. 5 and the lower part of the branch pipe formed separately.
FIG. 6 is a schematic view showing a mold rolling device used for locally increasing the thickness of the whole blank plate in a branch pipe forming method according to another embodiment of the present invention. IA: Raw plate, 10: Heating coil, 11: Hydraulic cylinder, 15: Swaging force, 17: Locally thickened portion, 18: Prepared hole, 19... Gui, 20...
・Punch, 22... Processing force, 24... Branch pipe upper part,
24a... Branch pipe part, 25... Branch pipe lower part, 27...
mold roll. Agent: Patent attorney Kosaku Fukuda (and one other person) Haya/I! ] 2nd Eye 3rd Eye I5 Steam 4 Kunikaga wo Eye 5 Certain 7th Eye/7

Claims (1)

[Scope of Claims] 1. After drilling a pilot hole in the locally thickened portion of a blank plate that has been locally thickened, simultaneously bending the blank plate into an arc shape,
The upper part of the branch pipe having the branch pipe part is formed by purling the hole edge of the prepared hole, and the upper part of the branch pipe is joined to the lower part of the arc-shaped branch pipe formed separately to form the branch pipe. A method for forming branch pipes characterized by forming them. 2. The method for forming a branch pipe according to claim 1, wherein the local thickness of the blank plate is increased by swaging using local heating. 3. The method for forming a branch pipe according to claim 1, wherein the local thickness of the blank plate is increased by partial rolling.