JPH03138024A - Manufacture of omega type bellows pipe - Google Patents

Abstract

PURPOSE:To effectively manufacture the bellows pipe without damaging or deforming of pipe by expanding the pipe with the flexible rubber material and with the chuck type component which is combined with the above and drawing the chuck type component to the radial direction after then. CONSTITUTION:The core metal 11 is inserted to the pipe body 10 which is formed with the expanded bead 9 of prescribed height and of mountain type cross section, and is made to the state of that the outer circumference of the core metal 11 is in contact with the bottom part of the valley part 9a of the expanded bead 9. The chuck type components 7a-7d which is divided around the axial center 6 is inserted in the valley part 9a of the expanded bead 9. The chuck type components 7a-7d is pressed to the pipe body 10 which is supported with the core metal 11 and also the pipe body 10 is pressed to the axial direction and is pressed respectively in contact with the recessed shape die 12 of cross section OMEGA type formed at both side of the chuck type component 7a-7d, the half of OMEGA type bead is formed respectively on the opposite side beyond the valley part 9a of the pipe body 10. The chuck type components 7a is moved to the Y direction and passed out. By moving the pipe body 10 by 1 pitch, the same process is repeated and the expanded bead 9 is formed to the perfect OMEGAtype bead.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing an Ω-shaped bellows tube, and more particularly to a method for manufacturing an Ω-shaped bellows tube having a beat having an Ω-shaped cross section on the outer periphery of a metal tube.

(Prior art) A bellows tube, which has a bead on the outer periphery of a metal tube, absorbs vibrations and has excellent pressure resistance, so it can be used in automobile exhaust pipes, piping around marine engines, air conditioning pumps, etc., which have a lot of vibration. Used for compressor piping, etc.

Bulge processing is used to manufacture bellows tubes, in which the outer periphery of the tube is wrapped in an outer mold of a predetermined shape, and the pressure inside the tube is increased to bulge the tube wall into the outer mold. Beats having a chevron-shaped cross section formed on the pipe wall by this type of bulge processing have the disadvantage that the top portion of the bead is thin, and becomes brittle and prone to cracking due to cold working.

On the other hand, in a bellows tube, it is theoretically known that if the beats formed on the tube wall have an Ω-shaped cross section, the tube will be resistant to bending, impact, or repeated loads.

Taking these into consideration, Japanese Patent Laid-Open No. 63-43729 proposes an Ω-shaped beading process for pipes in which a bead with an Ω-shaped cross section is formed on the tube wall.

FIGS. 3(a) to 3(C) are explanatory diagrams of the Ω-shaped beading method for pipes according to this proposal. As shown in FIG. 3(a),
A tube body 2 in which a bulge 1 with a chevron-shaped cross section has been formed by applying local internal pressure P to the tube wall is pressed with a mold 3 so as to sandwich the bulge 1 in the axial direction. Arrange tl. From this state, the press die 11 is moved closer to the press die 3, and through the process shown in FIG. Then, an Ω-shaped bead 5 having an Ω-shaped cross section is formed on the tube wall.

(Problem to be solved by the invention) In the Ω-shaped beading method for pipes according to the above-mentioned proposal,
Since the presses are arranged in the axial direction of the tube, after forming a plurality of Ω-shaped beads on the tube, it is necessary to pull out the presses located between the beads in the radial direction of the axis.

When the mold is pulled out, the mold often interferes with the formed bead, damaging or deforming the tube.

The present invention was made in view of the current state of manufacturing of Ω-shaped bellows tubes as described above, and its purpose is to efficiently manufacture Ω-shaped bellows tubes without damaging or deforming the tubes. An object of the present invention is to provide a method for manufacturing an Ω-shaped bellows tube.

(Means for Solving the Problems) In order to achieve the above object, the present invention forms a bulging bead of a predetermined height on the outer periphery of a tube, a flexible rubber material is housed at the tip, and the tube A chuck mold piece divided into several pieces around the axis of the bulging bead is inserted into the valley of the bulging bead, and the bottom of the valley is supported from inside the pipe, and the plurality of chuck mold pieces are inserted into the valley of the bulging bead. By combining around the axis, the tube is bulged into an Ω shape by the flexible rubber material and the combined chuck mold piece, and then the chuck mold piece is pulled out in the radial direction of the axis. Accordingly, an Ω-shaped bellows tube having an Ω-shaped bead is manufactured from the tube.

(Function) In the present invention, a chuck type piece having a flexible rubber material attached to the tip and divided into a plurality of pieces around the axis of the tube is used to attach the chuck type piece to the bulging bead of the tube in which the bulging bead is formed. Insert into the valley.

Then, by combining a plurality of chuck mold pieces around the axis, the flexible rubber material and the combined chuck mold pieces bulge the tube into an Ω shape.

After forming the Ω-shaped bead on the tube, the chuck mold piece is pulled out in the radial direction of the axis without soaking or deforming the tube.

In this way, Ω-shaped beads are successively formed on the tube to produce an Ω-shaped bellows tube.

(Example) Examples of the present invention will be described below with reference to FIGS. 1 and 2 (a) to (C).
).

Here, FIG. 1 is an explanatory diagram of a chuck mold piece used in the example, and this chuck mold piece 7 is divided into a plurality of chuck mold pieces 7a to 7d around the axis 6 of the tube. Flexible rubber members 8a to 8d are attached to the tips of each chuck mold piece 7a to 7d, and on both sides of each chuck mold piece 7a to 7d,
Half molds 12 each having an Ω-shaped cross section are formed.

As shown in FIG. 2(a), the well-known bulging or corrugating process that applies local internal pressure from inside the pipe to the pipe wall forms a bulging bead 9 of a predetermined height with a chevron-shaped cross section on the pipe wall. A core metal 11 is inserted into the tube body 10 so that the outer periphery of the core metal 11 is brought into contact with the bottom of the trough portion 9a of the bulging bead 9. From this state, the chuck mold pieces 7a to 7 are divided around the axis 6.
d, and only the chuck mold piece 7a is shown in FIG.

FIG. 2(b) shows a state in which the chuck mold piece 7a is inserted into the trough 9a, and the flexible rubber material 8a of the chuck mold piece 7a is attached to the surface of the tube body 10 in the trough 9a. It is deformed along. In the same figure (b), only the chuck mold piece 7a is shown, but in reality, the chuck mold piece 7a is
~7d are gathered in the same state.

From this state, as shown in FIG. 2(C), the chuck mold pieces 7a to 7d are pressed against the tube 10 supported by the core metal 11, and the tube 10 is pressed in the axial direction from one or both ends, and the chuck Each of the mold pieces 7a to 7d is pressed against a half mold 12 having an Ω-shaped cross section formed on both sides.

By this pressure contact, half of the Ω-shaped bead is formed on the opposing surfaces of the tube body 10 that sandwich the valley portion 9a.

Next, when the chuck mold piece 7a is moved in the radial direction shown by the arrow Y1 in FIG. There will be an omission. At the same time, the pond chuck mold pieces 7b to 7d are also treated in exactly the same manner, and the valley portion 9 is synchronized with the chuck mold piece 7a.
Detach from a.

In this state, the tubular body 10 is moved one pitch in the axial direction, and the same steps as shown in FIGS. to form.

Similarly, while moving the tube 10 one pitch at a time in the axial direction, Ω-shaped beads are continuously formed on the tube 10 to produce an Ω-shaped bellows tube.

Naya-ku type pieces 7a to 7 are divided around the axis 6 of the tube body 10 and have flexible rubber members 8a to 8d housed at the ends.
By moving d toward or away from the axis 6, Ω-shaped beads are successively formed on the outer periphery of the tube body 10, and during the manufacturing process, the chuck mold pieces 7a to 7d are formed into Ω-shaped beads. The pipe body 10 will not be damaged or deformed due to interference.

Furthermore, the shape of the Ω-shaped bead can be easily adjusted by changing the thickness of the flexible rubber members 8a to 8d. Sachi,
Since the desired range of the bulging bead 9 can be formed into an Ω-shaped bead, the bulging bead (chevron) and the Ω-shaped bead are combined and formed on the tube body 10, and the natural frequency of the tube body 10 can be adjusted. becomes possible.

In this manner, according to the embodiment, an Ω-shaped bellows tube with high flexibility and high vibration resistance can be manufactured without causing damage or deformation during the process.

(Effects of the Invention) As described above in detail, according to the present invention, an Ω-shaped bellows tube with high flexibility and high vibration resistance can be manufactured with high productivity without causing damage or deformation during the manufacturing process.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a chuck mold piece used in an embodiment of the present invention, FIGS. 2(a) to (C) are explanatory diagrams of each process in an embodiment of the present invention, and FIG. 3(a) -(C) are explanatory diagrams of conventional Ω-shaped beading processing. DESCRIPTION OF SYMBOLS 1... Swelling part, 2... Tube body, 3.4... Press mold, 6
...Axis center, 7a-7d...Chuck mold piece, 8a-8
d...Flexible rubber material, 9...Bulging bead, 9a...
・Trough, 10...Tube, 11...Core, 12...
Half mold. Figure 1 2yA

Claims (1)

[Claims] A swollen bead of a predetermined height is formed on the outer periphery of the tube, and a chuck type piece with a flexible rubber material attached to the tip and divided into a plurality of pieces around the axis of the tube is placed around the swollen bead. The chuck mold piece is inserted into the trough, supports the bottom of the trough from inside the pipe, and is combined with the flexible rubber material by combining the plurality of chuck mold pieces around the axis. A Ω-shaped bellows tube having an Ω-shaped bead is manufactured from the tube by expanding the tube into an Ω-shape and then pulling out the chuck mold piece in the radial direction of the axis. Manufacturing method of shaped bellows tube.