JPS5832526A - String extruding method of cylindrical shell - Google Patents

Abstract

PURPOSE:To perform string extrusion in an optional shape in a short time precisely by arranging and retaining segmental dies at the outside of a cylindrical shell, and inserting a pressing rod equipped with an elastic body into the cylindrical shell and then applying an axial load. CONSTITUTION:For the string extrusion of a cylindrical shell 1, a pressing rod 7 equipped with an elastic body 3 of annular rubber, etc., is inserted into the cylindrical shell 1. Sectional dies 2 each having a prescribed string shape worked in the internal surface are set at the outside of the cylindrical shell 1 facing the elastic body 3 and retained with a retaining rind 9. In this state, highly pressurized oil is fed from a hydraulic cylinder 6 to apply an axial load to the pressing rod 7, and thus the elastic body 3 is compressed to spread in radius directions. Consequently, internal pressure is allowed to operate on the internal surface of the cylindrical shell 1 in radius directions, thereby extruding the cylindrical shell 1 in the shape of grooves worked in the internal circumferences of the segmental dies 2. This method realizes excellent string extrusion in an optional shape.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is superior to the processing technology of locally pulling out strings (bead processing) at arbitrary positions in the axial direction of a long shell (cylindrical shell). This invention relates to a technique for performing a good string-drawing process (bead process) on the shape of.

Prior art shell beading is generally performed in a manner as shown in FIG. That is, a mandrel 2 having a predetermined shape is placed inside a shell 1, and bead rollers 3 are arranged at opposing positions outside the shell.
While rotating, press it against shell 1.
The string can be drawn out into a predetermined shape. but,
This method has the following drawbacks.

1. Because the mandrel and bead roller are pressed against each other during processing, the inner and outer surfaces of the shell become work hardened.

2 If the bulge height is large, the bulge becomes thin.

3. Processing time is long because it is extruded gradually while rotating.

4. It is necessary to apply a large radial load and rotation is involved, making the device complex.

5. For example, it is not possible to draw out a string in the shape shown in Figure 2.

The purpose of the present invention is to solve the disadvantages of the conventional technology, such as thinning of the string part, work hardening,
Our goal is to provide technology that can solve problems with processability, equipment, etc.

The processing method according to the present invention uses pressure to draw out the cord, and uses an elastic body such as the rubber of a soft tube as the pressure medium. That is, a split mold processed into the shape to be processed is placed at a predetermined position on the outside of the shell to be processed, while an elastic body such as rubber is placed at a predetermined position on the inner surface of the shell. By applying an axial load to the elastic body, the force (internal pressure) that causes the elastic body to expand in the radial direction is used to draw out the shell according to the shape of the mold. In this case, the split mold disposed outside the tube uses a restraining ring to restrain the load in the radial direction.

Embodiments of the present invention will be described below with reference to the drawings. Third
In the figure, 1 is the shell to be processed 2 is the split mold, 3
is a pressure medium (an elastic body such as soft rubber), 4 is a seal ring that prevents plastic flow by increasing the pressure of the elastic body, 5 is an auxiliary seal ring, 6 is a hydraulic cylinder, and 7 is an axial load added to the elastic body 8 is a spacer that defines the processing position, 9 is a restraint ring that restrains the mold, 1o is a hydraulic cylinder that controls the position of the restraint ring, 11 is a hydraulic cylinder that moves the split mold in the radial direction, 12 is a shell (This shows a hydraulic cylinder that applies an axial load. Note that 9' shows a state in which the restraining ring 9 is opened from the split mold 2, and 2' shows a state in which the mold 2 is opened.

In this embodiment, first, with the mold 2' and the restraining ring 9' in place, the shell 1 is set in a predetermined position, the hydraulic cylinder 11 is activated, the split mold 2 is closed, and the shell 10 is set around the shell 10. . Next, the hydraulic cylinder 10 is operated to set the restraining ring 9 on the outer periphery of the split mold 2.

In this state, when high-pressure oil is supplied from part A of the hydraulic cylinder 6 and 7 coupled to 6 is pulled downward and the reaction force is received by the spacer 8, the elastic body 3 moves in the axial direction. It is compressed and expands radially.

At the same time, internal pressure is applied to the inner surface of the shell 1 in the radial direction, and the shell 1 is processed into the shape of the groove formed on the inner periphery of the split mold 2.

In this machining procedure, if the bulge height is large and there is a concern about thinning of the string extension part, the cylinder 12 is operated in synchronization with the operation of the hydraulic cylinder 6 to apply an axial load to the shell 1. , the loss of thickness of the shell 1 can be kept small.

By performing the introduction process of the shell 1 as shown in FIG. 4 in this manner, the drawbacks of the prior art can be eliminated as described below.

The present invention performs static machining, as opposed to the dynamic machining of the prior art, and thus has the following effects.

1. Because mild machining is performed by applying internal pressure within the shell, there is no work hardening of the workpiece during the machining process, and no residual stress is generated.

2. If there is a concern about pale whitening of the machined part, it can be fixed by applying an axial load to the workpiece (shell) during the processing process.
Faint whitening can be reduced.

3. Accurate processing can be performed in a short time.

Claims (1)

[Claims] 1. In a method for forming a string in an arbitrary shape at an arbitrary position in the axial direction of a cylindrical shell, on the outside of a pressure rod having a head somewhat smaller than the inner diameter of the cylindrical shell at the tip. An elastic body such as a ring-shaped rubber is attached and placed inside the cylindrical shell, and a split mold with a predetermined string shape on the inside is placed on the outside of the cylindrical shell facing the elastic body. However, when the split mold is restrained by a restraining ring and an axial load is applied to the pressure rod, the elastic body expands in the radial direction. In the processing method, a hard elastic body is formed on both ends of the elastic body attached to the outside of the pressure rod in the axial direction. 3. In the cord pulling method according to claim 1, the split mold disposed on the outside of the cylindrical shell has a conical outer surface; 4. Cord drawing process according to claim 1 5. Cord drawing process according to claim 1.