JPS6037237A - Extrusion working method of annular part - Google Patents

Abstract

PURPOSE:To work efficiently defect-free annular parts having no under fill by inserting a fitting member which fills the bore of a prepunched blank material into said bore and subjecting the blank material to extrusion working while acting back pressure from the counter extrusion direction. CONSTITUTION:A blank material 1 consisting of preliminary punching is set into a blank material holder PH. A main punch P1 and an auxiliary punch P2 are lowered and the punch P2 is first inserted into the bore of the material 1. On the other hand a lower punch KO is raisen from below to support the bottom surface of the material 1. Forming is thereafter started and the punch P1 is lowered together with the punch P2 to force the material 1 into the die LD while the back pressure against the punch P1 is exerted thereto from below by the lower punch KO. The defect-free annular part product having no under fill and collapsion of the bore is thus easily obtd. with one stage.

Description

[Detailed description of the invention] The present invention relates to an extrusion processing method.

Machining of such parts is carried out using a hollow hole d as shown in Figure 2 (,).
. When product A is extruded using material 1 as a test material, as shown in FIG. Also, the initial inner diameter is deformed during machining.

Either it collapses as shown in B, or it becomes a complicated small hole. These are defective products and have no value as commercial products. Here, P indicates a punch, PH indicates a material holder, and LP indicates a mold.

The causes of the above defects will be explained with reference to FIGS. 3 and 4. FIG. 8 is a diagram showing a ring-shaped part being extruded by a press-fitting method.

Here, A1 to 86 indicate raw materials (molded products).

When measuring the length I of the under-walled part of the extruded molded product in this way, the under-thickness changes depending on the number of pieces to be extruded (the order of extrusion) as shown in FIG. In other words, the first one had a gap of 45 mm, while the second one had a gap of 1 mm.
From the 8th piece onwards, it is almost a complete molded product. here,
Looking at the measurement results for forming force P, the first one is P
For output 4 0 TON. The second one is Pki 7 0 7 ON
.

Starting from the third p: 8:9 6 TON is constant.

As you can see from this result, Ic, the third and later molds are already in the mold LD.
Since the mold is completely filled with the previous material, the molding force is also greater, allowing the mold to be filled with a third material. However, since there is nothing inside the first mold LD, the material does not fill the mold. Accordingly, the forming force also becomes smaller.

The second one is full of the ingredients from the first one.

It is easier to fill the material than one piece.

As can be seen from this, if the mold LD is not always filled with material, a product with insufficient thickness will be molded. Further, the hollow hole do becomes smaller because the outer periphery of the ring material is processed, and the inner diameter is compressed and crushed by the constraining force of the outer periphery processing. To prevent this, after extrusion.

Holes can be formed by machining or by inserting a guide rod into the inner diameter of the material to prevent the inner diameter from being compressed. However, in either case, there is a drawback that the processing steps are increased.

The present invention is an attempt to rationally solve the problem of underfilling and inner diameter change in the conventional method described above without increasing the number of steps.

Embodiments of the present invention will be described below with reference to FIGS. 5 and 6. FIG. 5 shows a method of extruding a ring-shaped part according to the present invention.

FIG. 5 (-) shows the external appearance of the device, and FIG. 5 (+) shows its operation sequence. Pl is the main punch, P2 is an auxiliary punch for protecting the inner diameter and is built into the main punch PI. PH silicon shrine holder, LD is the mold.

KO indicates a lower punch for applying back pressure to the material l from below. In such an apparatus, first, the material 1 is set in the material holder PH. after that.

Main punch P1. The auxiliary punch P2 is lowered and inserted into the inner diameter of the material 1. The lower punch KO rises from the other side of the trench and supports the bottom surface of material 1. After this, the molding process begins. The main punch PT descends and pushes the material 1 into the mold LD. At this time, the auxiliary punch P2 also descends at the same time. Pressure is still applied from the lower part so that the lower punch KO opposes the main punch P1.

In other words, as explained in Fig. 4, the reason for the lack of thickness is that there is not enough restraint force at the bottom to fill the mold with the material, so this shortage is compensated for by the bottom punch KO. The force applied by the lower punch at this time is 1. For example, in the example shown in FIG. 4, the force is Δp: 50 TON. In this way, extrusion processing is performed using the main punch P1 while applying back pressure ΔP from below. By using this method, the meat will no longer occur.

Moreover, the inner diameter of the ring is secured by the auxiliary punch P2, so there is no need to worry about the inner diameter being crushed. Therefore, a complete molded article A can be obtained from the beginning.

Figure 6 shows the molding process. The same figure (,) shows two cable trunks 'A'.
The state in which I and A2 are pressurized in the mold LD, and the state shown in FIG.

In the same figure (c), extrusion molding of the materials At and A2 has been completed.

The state in which the materials A8 and A4 are placed in the mold, and the state in which the material A5 is newly placed in the material holder is shown in (d) of the same figure.

In this way, when the material is sent, the main punch gate, the auxiliary punch P
2 rises, and when pressurizing, the main punch PI extrudes the material while the auxiliary punch P2 remains in the inner diameter of the material. 1. At this time, the material is processed while applying back pressure with the lower punch KO in order to prevent the material from being lacking in thickness from the lower part.

As explained above, the present invention is very efficient in extrusion processing of ring-shaped parts, and moreover, when using the press-fitting method, it is possible to process complete link-shaped parts with no underfill from the beginning.

[Brief explanation of drawings]

Fig. 1 is an external view showing an example of a molding object, Fig. 2 is an explanatory drawing showing a conventional method, Fig. 3 is an explanatory drawing showing forming by a press-on method, and Fig. 4 shows the underfill length and forming force. FIG. FIG. 5 shows an embodiment according to the present invention, and the figure (-) is a schematic sectional view. Figure 6 (b) is a process diagram, Figure 6 (a), (b),
(c) and (d) are process diagrams. Pl...Main punch, P2...Auxiliary punch, KO
...lower punch. Figure 3 Figure 4 Number of days of pushing wind ((I!il) ((1) (6) (C) , ((t)

Claims (1)

[Claims] In a method of extruding a ring-shaped part having an inner hole in the shaft core, the paulownia fitting part filling the inner hole is inserted into the inner hole of the pre-drilled material, and the back is removed from the opposite extrusion direction. A method for extruding a ring-shaped part, which is characterized by extruding from the beginning while applying pressure.