JPS632523A - Sealing method for split die - Google Patents

Abstract

PURPOSE:To enable pressure forming excellent in shape as far as a small curvature part of a material to be worked by disposing a die without split planes at adjacent to a sealing part of the material to be worked in case of bulging by an axial plane split die and adding high internal pressure on the material free from a possibility of leaking. CONSTITUTION:The pipe material 3 to be worked is put in the die 1a split at the axial plane, non-split die 1b is inserted into both the end parts of the pipe material 3 through a O-ring 2. The high pressure P is added to the inside of this sealing pipe material 3. Because, no split plane exists on the O-ring parts of both ends, the internal high pressure is allowed to applied sufficiently without any fear of leaking. Therefore, the material 3 is made possible to pressure forming up to the part of small curvature sufficiently.

Description

[Detailed Description of the Invention] [Industrial Application Field] The invention relates to a pressure sealing method in a molding technology that uses pressure. In particular, when high pressure is applied to a workpiece material, pressure may cause damage to the vicinity of the sealing part. Split metal suitable for preventing the mold from deforming and sealing material from escaping! ! ! Regarding.

[Conventional technology]

This will be explained by taking as an example bulge molding in which pressure is sealed in an O-ring. When sealing pressure using an O-ring, there is a correlation between pressure and clearance. Therefore, if it is desired to apply high pressure, the gap must be made as small as possible.

However, when performing bulge forming as shown in JP-A No. 56-154228, the entire mold is divided into multiple pieces along the axial cross section so that the molded product can be easily removed, and high pressure is applied to the material to be processed. No consideration was given to the fact that, if the mold was separated, the mold would be deformed and the gap between the dividing surfaces would become larger, causing pressure to leak.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not give sufficient consideration to the deformation of the mold caused by applying pressure, especially the deformation that increases the gap between the dividing surfaces in the vicinity of the sealing part, and there is a problem that high pressure cannot be applied. Regarding this, Figures 4 to 6
This will be explained using figures.

In FIG. 4, the mold 1a, which is divided into two in the axial cross section, is restrained by a mold clamping device (not shown), and both ends of the tube 3 of the workpiece material are pressed by the pressure rod 4. Bulge forming is performed by enclosing an internal pressure P applied through a pressure rod 4. Note that an O-ring is used as the sealing material.

However, if the pressure is high, deformation occurs in the split mold 12, and as shown in FIG. 5 of the C-C@ plane in FIG. There was a problem with the pressure leaking out.

In addition, as shown in Fig. 6, when using a non-divided mold 1b that is not divided in the axial cross section and combined at the center so that the workpiece material 3 can be taken out from the center, it is possible to prevent the mold from opening in the axial direction. To prevent this, it is necessary to add a restraining load F.

Furthermore, when taking out the material 3 to be processed, it is necessary to open the mold 1b beyond the length of the material 3 to be processed. When a hydraulic cylinder is used for the movement, a hydraulic cylinder with a stroke sufficient to take out the workpiece 3 is required, and in the case of a long workpiece 3, it is difficult to use a hydraulic cylinder.

An object of the present invention is to enable high internal pressure to be applied to a workpiece material within a mold, and further.

It is an object of the present invention to provide a split mold sealing method that can be applied even to long workpiece materials.

Measures to Solve Problem c] The above purpose is to arrange a mold divided in the axial cross section at the center, and undivided molds having an inner surface with a uniform cross-sectional shape near the sealing portions at both ends. This is achieved by

Note that if the sealing portion is at one end, a non-dividable mold is provided near the sealing portion.

[Effect]

When opening and closing the mold, the axially split mold provided with a trap in the center is opened and closed in the radial direction, and the non-divided mold with a --shaped inner surface, which is disposed at both ends, is moved in the axial direction.

Therefore, when carrying workpiece material into and out of the mold, the axially split mold located at the center opens radially, and the molds located at both ends open axially so that further workpiece material can be inserted. move it outside.

In addition, each mold is closed to perform bulge forming.

As described above, since there is no split surface near the sealing part of the material to be processed during bulge forming, the sealing material does not escape due to deformation of the mold, and high pressure can be applied to the material to be processed.

In addition, since the moving stroke of the non-divided mold with traps placed at both ends is short, it can be applied to the molding of long workpiece materials.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 shows a situation in which bulge forming is performed by applying internal pressure P to a workpiece material 3 using molds 1a and 1b. The workpiece material 3 presses against the 710-pressure rod 4 via the O-ring 2 to seal the internal pressure P. The mold has a split mold 1a that is divided into two in the axial direction at the center, and a non-divided mold 1b whose inner surface has a uniform cross-sectional shape at both ends, and a restraining device (not shown). ).

Figure 2 shows the A-A cross section in Figure 1, where the undivided mold 1b near the sealing part of the workpiece material 3 is less than 0 because there is no dividing surface in the axial direction.
The ring 2 does not escape, and bulge forming can be performed by applying a high pressure pt.

FIG. 3 is a sectional view taken along the line CC in FIG. 1), in which the outside 0111 of the workpiece material 3 is restrained by a two-part mold.

Also, a mold 1a for the workpiece material 3 after the molding is completed.

To take out from 1b, split mold 1a is divided in the axial direction.
This is done by opening nine in the radial direction and moving the undivided molds 1b at both ends outward. Here, since the inner surfaces of the undivided molds 1b at both ends have a --like shape, the workpiece material 3 can be extracted in the axial direction.

Note that the material to be processed 3 is inserted into the molds 1a and 1b in the same manner as the method for removing the material to be processed 3 described above.

The unique effect of this embodiment is that the shape of the inner surface of the undivided mold 1b arranged at both ends of the workpiece material 3 is -like, so that the load pressing the undivided mold 1b against the divided mold 1a is small. It's done.

In addition, since the length of the undivided mold 1b is sufficient at least to the extent that the seal portion of the workpiece material 3 is not located on the dividing surface of the undivided mold 1b and the divided mold 1a, the movement stroke of the undivided mold 1b is less. Therefore, the material to be processed 3
This mold can also be applied when the length is long.

〔Effect of the invention〕

According to the present invention, high internal pressure can be applied to the workpiece material during bulge forming, so that the workpiece material can be processed with a small radius of curvature of the bulge. It can also be applied to long workpiece materials.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing the principle of an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, and FIG.
-B! 4 is a longitudinal sectional view showing an example of the prior art, FIG. 5 is a C-cm lateral sectional view of FIG. 4, and FIG. 6 is a longitudinal sectional view showing an example of the prior art. . 1a...Divided mold, 1b...Non-divided mold, 2...
OIJ, 3... Material to be processed, 4... Pressure rond.

Claims (1)

[Claims] 1. When molding a material into a mold shape by applying internal pressure to the material in bulge forming, in the split mold sealing method that uses a split mold divided in the axial cross section, the split surface near the sealing part of the workpiece A sealing method for split molds, which is characterized by having a mold with no mold.