JPS5987931A - Manufacture of bellows - Google Patents

Abstract

PURPOSE:To form a perfect product of circular bellows etc. having a cylindrical part by holding a material tube by a core cylinder and plural forming rings from inside and outside, and swelling out the material tube into circular form etc. by pressing in pressure fluid into the gap between the material tube and core cylinder. CONSTITUTION:A core cylinder 2 is passed through inside of the material tube 1 of a bellows, and plural forming rings consisting of bisected main forming rings 5 and L-shaped auxiliary rings 7 are held covering the outside of the material tube 1 at specified intervals in axial direction. Then, pressure fluid is pressed into the gap (a) between the material tube 1 and a core cylinder 2. The forming rings 3 are contracted while applying internal pressure to the material tube 1, and parts of the tube where there is no forming ring are swelled out. When thrusted necks (b) are formed in the swelled out parts after contraction of specified distance, the forming rings 5 are opened, auxiliary rings 7 are removed, and main forming rings are closed after removing the auxiliary rings 7. Then, the rings are contracted applying internal pressure again and the swelled parts are formed to circular form and trough parts are formed into horizontal cylindrical sectional form. Thus, a perfect product of bellows free from deformation is obtained without leaving the forming rings.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing pepes in which a series of annular bulges giving the tube elasticity and flexibility are circular or cylindrical with horizontal cylindrical cross-sections at the valleys.

The method of the present invention will be explained below with reference to the drawings.

A monthly tube l for forming a bellows is fitted into a core cylinder whose outer diameter is slightly smaller than its inner diameter, and a number of molding rings 3 for forming a bellows are removably fitted onto the monthly tube l. Arrange them in parallel at regular intervals and hold them closely together.

The molded ring 3 is divided in half, and one end is pivoted to be openable and closable on the axis ψ.
The other end consists of a main molding ms provided with 7 flanges 5' and 6' and tightened with a tightening rod 6, and two auxiliary rings 7 formed in an L shape, with the main molding ring S perpendicular to the inner center. A recess 9 into which one end of the auxiliary ring 7 formed into an L shape is fitted at both ends of the annular piece. q is provided, and the flange 10 is bent to have a T-shaped cross section, and the auxiliary ring 7 is placed back to back on the left and right around the annular edge, with one end formed into four parts 9. The other end of the piece δ is made to protrude outward, and the inner end surface and the inner surface of the current piece δ are on the same plane.
Close to.

Next, in order to form the bellows, hydraulic pressure is applied within the gap α between the material pipe l and the core cylinder, and the molding ring 3 placed in the raw material pipe l is
, 3 is bulged out to form an arc shape, and while applying hydraulic pressure to bulge out, the old tube 1 is contracted in the axial direction along the core tube 1 until it is shortened to a certain distance as shown in Fig. ε. As shown in FIG. 5, one end of the auxiliary ring 7 extending outward is fitted to both sides of the bulging arcuate portion 5 to form an arcuate bellows.

Next, the main molding ring S is untightened, the auxiliary ring is left as it is, and opened to a certain position, and the auxiliary rings 7, 7 are pulled together and moved into the space where the vertical annular piece is removed, and the overhanging end is moved. After removing the auxiliary rings 7 and 7 from the neck part, the main molding g
Close and tighten 3 again, and contract while applying internal pressure again to contract the material tube l until the side of the bulge comes into contact with the vertical annular piece.
It is further contracted and pressure is applied to the bulging part using the annular piece t, and the bulging part becomes higher one by one until the top hits the flange 10 of the main molding ring 5. Pressure is applied by the flange to form a bellows, and when the main molding g3 is further opened, the elasticity is increased. This creates a predetermined gap in the horizontal portion of the bellows, resulting in an arcuate bellows with excellent elasticity.

In order to mold it into a Sui circular shape, the shape of the molding ring should be a Sui circular shape.

Unlike conventional bellows, the circular bellows having a cylindrical portion of the present invention is molded using a molding ring 3 consisting of a half-split main molding Bs and an auxiliary ring 7, so that a complete product can be obtained without leaving any molding ring. In addition, there was a conventional method of forming a cylindrical ring and then stretching the bellows, but once the bellows was formed, if you stretched it until the forming ring came off, it would deform and a complete product could not be obtained. It is convenient and has a horizontal cross-sectional cylindrical shape that does not expand or contract, so the flow is good, and the fluid does not come into direct contact with the expandable part as in the past, making it particularly effective for high-temperature exhaust pipes. In addition, since there is no molded ring as in conventional molding, it is light in weight and can withstand slight vibrations.

[Brief explanation of the drawing]

The drawings show an embodiment of the bellows manufacturing method according to the present invention, and FIG. 1 is a partially cutaway front view of the bellows, and FIG.
The figure is an explanatory diagram of the manufacturing process order, and Figure 3 is an enlarged view of a part of it.
Cr shaft ring size 5゜l ---Material tube C...Core tube 3...Molding mg...11H S...Main molding ring
S'...7 lunge 6 river hosodake rod 7...auxiliary '6t
...Current piece 9...Concave portion 10...Bent tsuba α
...Gap h...Neck -17 (

Claims (1)

[Claims] A core tube is inserted into the inside of the bellows's monthly tube, and a plurality of molded rings consisting of a main molded ring halved and a pair of L-shaped auxiliary half rings are removably attached to the raw material tube at regular intervals in a linear direction. While fitting and holding the tube, pressurized fluid is applied to the gap between the material tube and the core tube to first bulge the bent portion of the molded ring of the monthly tube.
Next, the lunar canal is contracted in the axial direction while applying internal pressure, and the bulging part is gradually bulged out by the pressure. When the bulging part is shortened by a certain distance and a neck is obtained, the main molding ring is opened and the auxiliary ring is removed. The forming ring is closed and compressed by applying internal pressure again, and the sides and height of the bulging part are pressurized by the main forming ring, so that the bulging part has a circular or circular cross section and a horizontal cylindrical cross section at the valley part. bellows manufacturing method.