JPS6336857B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a branch pipe joint, and an object of the present invention is to manufacture a branch pipe easily and at low cost using a simple device.

In the manufacturing of branch pipe joints, in which a joint is formed in a T-shape protruding from the side of a straight pipe and a joint pipe is connected to the joint, various methods have been proposed using large-scale equipment. A method of forming a joint using a simple device has also been proposed.

In other words, in the case of small-diameter joints, a forming tool can be inserted into the straight pipe to form the joint.
In the case of large-diameter joints, this method could not be used and a special drill with a blade was used to form the joints, but the problem was that the equipment became larger and the cost increased.

The present invention is proposed to solve these problems, and examples of the present invention will be described below.
A round-shaped hole is formed at an appropriate position in the body of a short vertically long raw tube, the raw tube is fixed to a molding device, a small ball is placed inside the raw tube, and the ball is received on a pedestal so that it is positioned inside the hole. After applying pressure with a cam rod to push the hole open from the inside, the small sphere is passed through the original tube and taken out.
Manufacture of a branch pipe joint characterized in that a molded ball larger than the small ball is inserted again and the periphery of the pressed hole is made to protrude outward in a secondary step to open the hole and form a branch opening. It is about the method.

First, a circular hole 8 is press-formed at an appropriate position in the body of the original tube 1. If this hole 8 is a circular shape along the longitudinal direction of the master tube 1 as shown in Fig. 1, when stress is concentrated here in a later process, the longitudinal flat surface of the master tube 1 surface will protrude only slightly. However, the curved surface in the lateral direction protrudes greatly, and the whole can be made to protrude evenly in a circular shape.

This original tube 1 is fixed in a molding device in a first step as shown in FIG. The molding device includes molds 5 and 6 that support the body of the original tube 1, a central stand 7, and a pedestal 4.
It consists of A through hole 9 is formed in the mold 6 at a location corresponding to the hole 8 of the original tube 1. A guide groove 10 is formed on the surface of the pedestal 4 on which the small balls 3 are placed, as shown in FIGS. ing.

After fixing the original tube 1, the small ball 3 is placed on a pedestal 4, and is pressed from above via a press device with a cam rod 2 whose tip is cut into a slope with its tip facing the rear. When the small ball 3 is placed on the pedestal 4, it does not maintain a fixed position, but when the pressing force of the cam rod 2 is applied, it is forcibly moved to the guide groove 10 of the pedestal 4, and is further pushed. When pressure is applied, the small sphere 3 is gradually pushed out toward the through hole 9 of the mold 6. This is because the tip of the cam rod 2 is cut into a slope toward the rear, so that a pressing force acts to push the small ball 3 forward.

Furthermore, by forming the small ball contacting surface 19 of the cam rod 2 into a concave surface as shown in FIG.
This has the advantage that it becomes easier to move to the center, is guided by the guide groove 10, and is guided in the direction of the through hole 9.

Note that when the cam rod 2 is pushed down, the protruding tip of the cam rod escapes into the sloped space of the recess of the corresponding pedestal 4, so there is no problem caused by contact between the cam rod tip and the pedestal 4. do not have.

By pushing out the small balls 3 in this manner, the hole 8 of the original tube 1 is deformed so as to bulge outward within the through hole 9 of the mold 6, as shown in FIG. Since this step is the first step for the original tube 1, it is carried out to the extent that the area around the hole 8 of the original tube 1 is not torn. Experiments have shown that it is effective to set the size of the small balls 3 to about 0.85 to 0.9 times the inner diameter of the original tube 1, and that it is necessary to finely adjust the pressing force of the cam rod 2.

The raw tube 1 that has completed the first step is transferred to the second step as shown in FIG. 3, but at this time it may be fixed again to another molding device with a different diameter of the through hole. This device is similar to the one in Fig. 2, but the molded ball 12 corresponding to the diameter of the joint pipe is larger in shape than the small ball 3 in the first step, and has a diameter slightly smaller than the inner diameter of the original pipe 1. Therefore, the sizes of the through holes 16 of the mold 15 are configured to be different.

After placing the molded ball 12 on the pedestal 13, the cam rod 1
As the molded ball 12 is pressed through the press device in step 1, the molded ball 12 is moved toward the through hole 16 of the mold 15 so as to push open the expanded portion of the original tube 1 from the inside, so that the molded ball 12 is finally pressed. The periphery of the hole 8 is bulged and protrudes outward.

At this time, the molded sphere 12 is pushed out from the inside of the original tube 1 to the outside. The peripheral edge of the hole 8 thus protruded becomes a circular protrusion, and a branch opening 17 is formed.

Since the front side base of the branch opening 17 is formed in an R-shape, when connecting the joint pipes, there is an effect that even pipes with slightly different diameters can be easily connected and closely joined together.

As described above, according to the present invention, a large-diameter branch pipe joint can be easily formed using a simple device, and manufacturing costs can also be reduced.

[Brief explanation of the drawing]

FIG. 1 is a partial front view of the main tube body. Figure 2 shows
FIG. 3 is a vertical cross-sectional view showing a state in which molding is performed using a fixing device in a first step. FIG. 3 is a longitudinal cross-sectional view showing the state of molding with the fixing device in the second step. FIG. 4 is a longitudinal sectional view of the molded branch pipe. FIG. 5 is a plan view of the pedestal. FIG. 6 is a front view of the pedestal. FIG. 7 is a side view of the cam rod.
FIG. 8 is a sectional view taken along line A-A' in FIG. 7. In the figure, 1: original tube, 2: cam rod, 3: small ball, 4:
cradle, 5: mold, 6: mold, 7: central stand,
8: hole, 9: through hole, 10: guide groove, 11: cam rod, 12: molded ball, 13: pedestal, 14: mold,
15: Molding die, 16: Through hole, 17: Branch opening, 18: Slope, 19: Small ball contact surface.

Claims (1)

[Claims] 1. An elliptical hole is formed at an appropriate position in the body of a short vertically long master tube, the master tube is fixed to a molding device, and a small hole of about 0.85 to 0.9 times the inner diameter of the master tube is formed inside the master tube. A guide groove is provided on the small ball mounting surface so that the ball is placed inside the hole, and the small ball is received on a pedestal with a recessed slope space. After the first step of cutting the rear part into a slope and applying pressure with a cam rod with a concave surface in contact with the small ball at the tip, the small ball is passed through the original tube and taken out, and a molded ball larger than the small ball is inserted again and A method for manufacturing a branch pipe joint, characterized in that a branch opening is formed by opening the hole in a secondary step of protruding the periphery of the hole pushed open by a small ball outward. 2. Manufacture of the branch pipe joint according to claim 1, characterized in that in the secondary step, a separate molding device with a different diameter of the through hole is used to open the hole with a molded ball to form the branch opening. Method.