JPS6054224A - Pressure-reducing method in case of high temperature hydrostatic pressure extrusion - Google Patents

Abstract

PURPOSE:To prevent jetting and contamination of a medium by moving backward a working stem after an extrusion, subsequently, moving backward a container from a fitting die, and reducing a pressure of a pressure medium, in case of an extrusion through a viscous plastic pressure medium of a high temperature billet. CONSTITUTION:A high temperature billet 18 is extruded from a gap of an inner hole 6 of a die 3 and a tip 17 of a supporting rod 16 by pressure of a seal piston 11 by a pressure stem through a viscous plastic pressure medium 14. The pressure medium 14 is brought to pressure-reduction by moving backward the pressure stem 10 and moving backward a container 8 by a piston 9, and it is not feared that the medium is jetted and contaminated after the end of the extrusion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for high-temperature isostatic extrusion of pipe materials and solid materials, in which the pressure is increased and then the pressure medium is reduced after the end of extrusion, and the present invention relates to a method for reducing the pressure of the pressure medium after the extrusion is completed, and in which the pressure medium is ejected when the container is opened. The main purpose is to prevent contamination and burnout of equipment, as well as to completely prevent deterioration of pipe material quality.

Traditionally, pressure medium inside a container? The pressure is increased to ultra-high pressure via a seal piston, and the generated hydrostatic pressure is used to load the high-temperature billet into a container, which is defined by the inner hole of the die and the tip of the mandrel that is inserted and fixed into the inner hole of the die. Tube material through the annular space? Double acting isostatic extrusion methods are well known.

Also, a method of extruding a solid material using a billet support rod (gutsusha) in place of the mandrel is also well known.

This high-temperature isostatic extrusion method has better lubricity during billet extrusion than normal ram extrusion, and
It has attracted particular attention in recent years because it has excellent properties such as no friction acting between the container and the billet.

By the way, after extruding a tube material or a solid material by high-temperature isostatic extrusion using a sealed piston, it is necessary to reduce the pressure of the pressurized medium.

For this reason, conventionally, after the end of extrusion, the pressure stem is fully retreated to remove the pressure, but according to this method, the pressure medium still maintains a pressure equivalent to the resistance force of the seal packing in the seal piston, and therefore , after the depressurization process due to the pressure stem retreating, when the container kR is released,
Not only is the pressure medium spouted outside the container, causing equipment contamination and burnout, but when the entire mandrel tit is pulled out, the pressure medium spouts out and adheres to the inner surface of the pipe material. It had deteriorated significantly.

Therefore, the present invention ensures that the pressure medium is depressurized while sealing the container after extrusion is completed, and
The above-mentioned problem is solved by pulling out the mandrel chip after the pressure is reduced.

Is the drawing below? An example of the present invention will be described in detail with reference to the drawings.

@Figures 1 to 4 are for pipe materials, lol! Figures 15 to 7
The figures chronologically illustrate each process such as mid-extrusion, end of extrusion, and depressurization for solid materials.
Reference numeral 1 denotes an opposing frame, which faces a cylinder frame (not shown) and is rigidly connected with a column or the like to constitute the entire press frame.

The press center of the opposing frame +11 has a die slide (2
) A die (3) is attached through the vL-, and the die (3) is provided with a sealing pad (4) on its outer periphery,
Rear end conical part 15) Of course, the inner hole (6
) is formed.

The container (8) supported via the holder 1711 is fitted and fixed to the die (3), and the seal packing [41
Pressure medium leakage is prevented through this.

The container (8) can be moved back and forth in the press direction by a cylinder mechanism (9), and the container (8)
can be changed to a closed position in which it is fitted into the die (3) and a firing position in which it is pulled out from the die (3).

The pressurizing stem has a hollow structure and is movable back and forth by a pushing force generating mechanism (not shown), and a seal piston (river) is attached to its tip.

It is fitted into the seal piston (cylindrical in shape, container 18), and seal pads are attached to the outer and inner peripheries of the container (8). The viscoplastic pressure medium tI411, for example, can pressurize graphite grease or the like to an ultra-high pressure.

The pressure medium is, for example, 0.01 to 0.05 cod weighed and sealed in a polyethylene bag and supplied into the container 18, and the bag can be burned by bringing it into contact with high-temperature billet (IlliIVC). It can be supplied by carbonization, but other means can also be followed.

The high-temperature billet σ5) has a conical tip and is supported by a conical portion (5) of a die (31) via a lubricant, and in the case of a pipe material, it is perforated with a tip 0η of a mandrel Q11. In the case of wood, the tip of the bushing is billet 1.
151, and this mandrel and stubble are hereinafter referred to as billet support rod Q61.

The billet support rod discharge has a stem (
! It is pressed into ω and protruded through the seal piston +Illk, and when it is a pipe material, the perforated belet l-115
The tip Oη is inserted into the inner hole +e+ by penetrating the inner hole 1B+, and the tip αη is fixed immovably in the axial direction at least during extrusion. Billet) (+61 is hydrostatically extruded, and the pipe material (
18+ can be manufactured.

That is, in the state shown in Fig. 1, when the pressurizing stem is advanced by <Io+2, the pressure of the pressure medium (I4) is increased to an ultra-high pressure via the seal piston (I), and the high temperature billet 1151 is pushed into the inner hole of the die (3). It is extruded by hydrostatic pressure through an annular space defined by 1B+ and mandrel tip 0η, and a specified tube material (1111 is obtained.And when it is a solid material, 8
As shown in Fig. g5, a billet support rod (16:) is brought into contact with the rear end surface of the billet rod, and a solid material is obtained through the inner hole (6).

Therefore, after the extrusion shown in Figs. 2 and 5, the
First, pressurize f-A flol k! If! As shown in Figures 3 and 9g6, there is a transition to the backward pressure relief stroke, and as a result, the pressure medium thickness changes from Ll in Figures 2 and 5 to L2 in Figures 3 and 6. .

However, the seal piston (+1) seal piston 021f131 requires a tension P of 10 to 20% of the maximum pressure in order to maintain sealing performance during extrusion, and the pressure corresponding to the frictional resistance is applied to the pressure medium. Therefore, when the container (8) is fully retreated from the pressure relief stroke shown in Figures 3 and 116 and transferred to the pressure reduction stroke, and the billet support bar marked a is fully retreated for the next stroke, the pressure medium is Since the pressure is approximately several tens of atmospheres, it will eject onto the inner surface of the pipe material, the end of the solid material, around the die slide (2), etc., and cause contamination of the pipe material, solid material (1), equipment contamination, etc. .

Therefore, in the present invention, the pressure stem shown in FIG. 6 and FIG.
81 tK Move backward by the number shown in Figure 4 and Figure Wi7.

This retreat amount corresponds to the compressed residual amount of the pressure medium, and is approximately L=(
0.3-0.6) corresponds to T5F-. Here, V: pressure medium amount D i is the inner diameter of the container.

The pressure of the pressure medium becomes zero due to the amount of retraction of the container 18), but the seal packing (4) of the die (3) and the seal packing (I) of the seal piston (11)
All odor α-loose maintains their sealing function,
As the container (8) moves back, the seal piston (lI) is pushed back (although it is less than the above-mentioned retreat due to the resistance force of the odor), and the lees (18A) are pushed back as shown in Figures 4 and 7. In addition, at i o, o o o atmospheric pressure, the pressure medium is approximately 2
Since it is compressed beforehand, it is desirable to set it to about 1.2Ls (L3).

Then, with the pressure medium force completely reduced to zero, the billet support rod t+s
1 and by retracting the container (8) again or continuously retracting it, the pressure medium is removed from the sealing piston (Ill.
The pressure medium discharged from the container (8) in this way is completely depressurized, so it will not spout out. No contamination of pipe materials, equipment contamination, burnout, etc.

In this way, after completely discharging the pressure medium, press lees (18A).
The pipe material and the pipe material are cut by a shear mechanism (not shown), and one press cycle ends here.

In short, in the present invention, the pressure stem +1 (I
The seal piston attached to the tip of the tlll i 1. The viscoplastic pressure medium inside the container (8) is pressurized and the generated hydrostatic pressure is increased. The high-temperature billet (I51) in the container (8) is connected to the pressure medium A4 seal packing (
billet support rod αflli fitted and pressed into the inner hole (6) of the die (3) and the seal piston (11) having
- In an extrusion method in which extrusion is performed through
By retracting the container (8) while maintaining the seal WA1 between the pressed lees and the die (3) by the pressing force of the seal gasket (4) and the billet support rod [161], the seal piston (Illk) is retracted and the pressure is increased. The pressure medium (1411-depressurized) and then the billet support rod (Iev
Since it relates to a pressure reduction method in high temperature isostatic pressure extrusion characterized by i-retreating, it has the following advantages.

After the extrusion is completed, the container (3) is moved back and the pressure is reduced while maintaining the pressure medium a4J't sealed mt under increased pressure inside the container (81), so there is no blowout of the pressure medium inside the container (81) and there is no risk of equipment contamination, burnout, etc. can be avoided.

In addition, after completely depressurizing the pressure medium, billet support rod agIt
Since the pipe material is pulled out through the inner hole fi+ of the die filO, the amount of pressure medium does not spray out and adhere to the inner surface of the pipe material, and a high quality pipe material (lt- can be obtained by hydrostatic extrusion).

[Brief explanation of the drawing]

Figures 1 to 4 are cross-sections of main parts showing the process of the present invention in the case of a tube material as an example, and Figure 1 is a cross-sectional view during extrusion;
FIG. 2 is a sectional view after extrusion is completed, FIG. 6 is a sectional view of the depressurization process, FIG. 4 is a sectional view of the depressurization process, and FIGS. 5 to 7 show the process in the case of solid material. @Figure 5 is a cross-sectional view after extrusion is completed, and Figure 6 is a cross-sectional view during the pressure relief process, lll! Figure 7 is a cross-sectional view of the decompression process.
(6)...Inner hole, (8)...Container, (Io...
・Pressure stem, (Ill...Seal piston, 04J
... Pressure medium, (I61... Billet support rod. Patent applicant Kobe Steel, Ltd. Figure 1 Figure 2 Figure 14 Figure 3 Figure 4 Figure 18A 12

Claims (1)

[Claims] 1. The pressure of the viscoplastic pressure medium +141 inside the container (8) is increased through the nine seal screws (11)'fz attached to the tip of the pressurizing stem (10), and the generated hydrostatic pressure is used to increase the pressure of the container (8). In an extrusion method in which the high-temperature billet i51 in ) is extruded through the billet support rod ue+i fitted into the inner hole (61) and the seal piston (ue+i) of the die (3) having the seal gasket (4) for the pressure medium round. , After the extrusion is completed, the pressurizing stem f+01 t- retreats to remove the pressure, and then the pressed lees and the die (3) are pressed by the pressing force of the seal packing (4) of the die (3) and the billet support rod 061.
) by fully retracting the container (8) while maintaining a seal between the piston (full)? A pressure reduction method in high-temperature isostatic extrusion, which is characterized in that the pressure medium H1 that has been pressurized is retreated and the pressure is reduced, and after 7, the billet support rod 061 is retreated.