RU2302918C2 - Apparatus for shaping radially-corrugated bellows type tubes - Google Patents

Abstract

FIELD: plastic working of metals, possibly manufacture of radially corrugated bellows type tubes.

SUBSTANCE: apparatus for shaping bellows type tubes includes lower die detachable along its axis and punch. On inner surface of die there are dents and indentations corresponding to profile of bellows. Punch is mounted stationary and it has annular grooves on lateral surface for placing elastic shaping members. Punch also has radial ducts whose number is equal to number of shaping members and axial ducts. Apparatus is provided with distributing unit. Each radial duct is communicated with pressure source through its own axial duct and distributing unit.

EFFECT: enlarged manufacturing possibilities, enhanced efficiency, simplified design of apparatus.

3 dwg

Description

The present invention relates to the processing of metals by pressure, in particular, to devices for forming radially corrugated pipes of the bellows type.

A device for forming radially corrugated pipes of the bellows type is known, containing an axially detachable matrix and a fixed punch. On the inner surface of the matrix protrusions and depressions are made, repeating the profile of the bellows, forming elements are located in the depressions.

An axial hole is made in the punch, in which an axially movable rod is installed, having an axial channel and an annular groove on the side surface. In addition, the punch made radial channels that connect the elastic forming elements through a recess on the rod and the axial channel with a pressure source [patent No. 2176941, IPC B21D 15/10]

The disadvantage of this device is its low performance, because it allows the bellows to be molded by sequential axial retraction of the unformed part of the pipe (one end thereof) into the cavity of the cavity on the matrix, and only one corrugation can be molded in one step of the rod.

A disadvantage of the device is that during its operation, leakage of the working medium through the sealing elements of the stem in the punch is inevitable, leading to a decrease in the pressure applied to the elastic elements in the area of the molded corrugations. When forming the next corrugation, a decrease in pressure on the elastic element in the area of the locked molded corrugation leads to its deformation due to the flow of a certain amount of material into the molded corrugation due to the extraction of material from the previously formed corrugation, which distorts its shape.

In addition, the presence of a movable element - rod complicates the design of the device, because a mechanism for moving it is needed.

Also known is a device for forming radially corrugated bellows pipes, which contains an axially detachable matrix, protrusions and depressions repeating the profile of the bellows are made on its inner surface. The device also contains a punch, in its lateral surface there are two annular grooves in which elastic forming elements are placed. In the punch, radial channels are made according to the number of forming elements and an axial channel that can communicate with a pressure source. Using one of the elastic forming elements, one corrugation is formed, and with the subsequent movement of the punch, the second element fixes the corrugation relative to the matrix and calibrates it [E.I. Isachenkov. “Stamping with rubber and liquid”, Moscow: Mashgiz, 1962, p. 245, Fig. 172 (b)].

This device is devoid of one of the drawbacks of the previous one - the presence of leaks between the stem and punch, because stock is missing.

However, it also allows the bellows to be molded by sequential axial retraction of the undeformed part of the pipe into the cavity of the cavity on the matrix and does not allow to form several corrugations simultaneously.

In addition, in such a device, it is necessary to relieve the load applied to the elastic forming elements after each molding cycle in order to return these elements to their original position and move the punch along the axis of the formed workpiece.

The presence of a mechanism for moving the punch complicates the design of the device.

The invention solves the problem of providing the possibility of forming corrugations both sequentially and simultaneously in the directions of both ends of the pipe billet and providing the possibility of forming two corrugations simultaneously, which increases the productivity of the device. In addition, the invention solves the problem of simplifying the design of the device by eliminating the movable punch and the mechanism for moving it.

The problem is solved in that the device for forming radially corrugated pipes of the bellows type contains an axially detachable matrix, on the inner surface of which there are protrusions and depressions that repeat the profile of the bellows, and a punch. In the lateral surface of the punch, annular grooves are made with elastic forming elements placed therein. The punch also has radial channels in terms of the number of forming elements and an axial channel that can communicate with a pressure source.

New in the invention is that the device is equipped with a distribution block, the punch is made stationary and provided with additional axial channels. Each radial channel is connected to a pressure source through its axial channel and distribution block.

The accompanying drawings show:

figure 1 is a hydromechanical diagram of a device for forming radially corrugated pipes;

figure 2 is a process sequence for forming a radially corrugated pipe in the direction from the middle zone to the ends of the pipe;

figure 3 - some technological capabilities of the device for forming a radially corrugated pipe.

A device for forming a radially corrugated bellows-type pipe contains a matrix 1, detachable along the axis 2, and a fixed punch 3. On the inner surface of the matrix 1 there are protrusions 4 and depressions 5, repeating the profile of the bellows. In the lateral surface of the punch 3, annular grooves 6 are made, in which the elastic forming elements are placed 7. In the punch 3, radial channels 8 are also made according to the number of forming elements 7 and axial channels 9, the number of which is equal to the number of radial channels 8.

The device is equipped with a pressure source 10 and a distribution block 11. Each radial channel 8 is connected to a pressure source 10 through its axial channel 9 and a distribution block 11, the number of valves in which is equal to the number of channels 9. The device is equipped with a drain 12.

The device operates as follows.

Before performing the operation of forming corrugations on the tubular billet, the elastic forming elements 7 are compressed (Fig. 1), located at the minimum possible distance from the axis 2. Moreover, the outer surfaces of the elements 7 are located on a circle whose diameter is slightly smaller than the outer diameter of the punch 3, and radial 8 and axial 9 channels for supplying the working fluid to the annular grooves 6 are connected to the drain 12.

The semi-matrices forming the matrix 1 are bred from each other in the radial direction. Tubular billet 13 is put on the punch 3 and close the matrix. Then, at the command of the operating mode setter (not shown), for example, a controller unit with a predetermined response program for the solenoid valves in the distribution block 11, the pressure from the distribution block 11 is alternately supplied through the axial 9 and radial 8 channels to the desired elastic forming element 7.

Corrugation on the pipe billet can be carried out in any sequence.

First, pressure can be applied to the far right elastic element 7, then to the next, etc. until the complete formation of the radial corrugations on the pipe billet, i.e. carry out sequential molding.

Corrugations can also be formed from the middle zone of the workpiece to its edges (Fig. 2), then the axial retraction of the ends of the pipe occurs simultaneously from two sides, and two corrugations located on both sides relative to the originally molded corrugation or corrugations are formed.

When applying pressure to the next elastic forming element, the pressure of the working fluid is maintained on the molded corrugations. This ensures that molded corrugations are blocked, preventing their plastic deformation and distortion of shape.

The device also allows the formation of single corrugations or blocks of corrugations, separated along the length of the tube stock by cylindrical, undeformed sections, as shown in Fig.3.

The return to the initial position of the elastic forming elements 7 is carried out by communicating the annular grooves 6 on the punch 3 with a drain 12. To facilitate the return of the elastic elements 7 to their original position, you can also impose an additional load on the outer surfaces of the elements 7, for which pressure is supplied from the pressure source through the channel 12 10, for example, compressed air. Thus, all the elastic forming elements 7 are returned to their original position, the half-matrix open and remove the radially corrugated pipe (bellows).

All elements of the device are ready to repeat the described molding cycle.

Such a device allows forming corrugations on a pipe billet both sequentially and simultaneously in two directions, which increases its productivity. The device does not have moving parts, which simplifies its design.

Claims (1)

A device for forming radially corrugated bellows-type pipes, containing an axially detachable matrix, on the inner surface of which there are protrusions and depressions repeating the bellows profile, and a punch made with annular grooves on the side surface, in which elastic forming elements are placed, as well as radial channels in the number of the mentioned forming elements and with an axial channel having the ability to communicate with a pressure source, characterized in that it is equipped with a distribution block, it is stationary and with additional axial channels, and each radial channel is connected to a pressure source through its axial channel and distribution block.

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