JPS5810964Y2 - Extrusion head for metal sheath extruder - Google Patents

Description

[Detailed description of the invention] The present invention relates to an extrusion head for an extruder, and more specifically, an extrusion head for a metal sheath extruder in which an extruded billet is pressed from two opposite directions perpendicular to the extrusion direction. It is related to the head.

Extrusion of a metal sheath, such as an aluminum sheath, is generally performed using a Schlemann type extruder, but this extrusion method is performed in such a way that, as shown in FIG. However, when extruding the sheath in a cylindrical shape using this method, the following problems have arisen.

That is, if the pressure applied to the extruded material within the die block during extrusion is uniform, the thickness of the sheath extruded from between the die 2 and the nipple 3 in the circumferential direction will be uniform; As the pressure increases in the area corresponding to the direction of movement of the ram, the nipple deforms into an oval shape and becomes thicker in the extruded sea or the position corresponding to the direction of movement of the extrusion ram as shown in Figure 2. The problem was that it became thinner at right angles.

Such a sheath having a non-uniform thickness in the circumferential direction, for example, cannot be subsequently corrugated into a normal corrugation by processing, which causes deterioration of the mechanical properties of the sheath.

This invention was made to solve the above problem.
In order to make the thickness of the extruded sheath uniform, when extrusion pressure is applied, the gap between the outer circumference of the nipple opening and the inner circumference of the die opening at the exit of the extruded material is made to be approximately equal around the entire circumference. This objective is distantly related by forming the outer periphery of the nipple opening or the inner periphery of the die opening into an elliptical shape.

The details of the present invention will be explained below with reference to the drawings.

In FIG. 1, a cylindrical nipple 3 is arranged concentrically within the opening of the die 2, and the nipple 3 is held by a nipple holder 4.

The extruded billet is extruded from the A and A' directions by an extrusion ram (not shown).
presses into the die block, and the die 2
The sheath 1 is extruded and coated around the cable core 5 from the gap a of the nipple 3, and then the sheath 1 is corrugated if necessary.

As mentioned above, during extrusion, the pressure distribution of the extruded material within the die block becomes uneven, so the nipples 3 are
Although it is compressed in the forward direction, as shown in FIG.
The ratio of the major axis to the minor axis is such that the tip 3a of the nipple becomes approximately circular when pressure is applied.

Or, as shown in Fig. 4, the shape of the die 2, that is, the inner circumferential surface 2a is an ellipse with the short axis in the A-A' direction, and the ratio of the long axis/short axis is deformed into an ellipse when pressure is applied. The gap between the tip of the nipple and the tip 3a is made to be approximately equal over the entire circumference.

The extrusion pressure reaches the maximum pressure at the extrusion diameter, and then gradually decreases to the minimum pressure due to the reduction of the pressure increase due to friction and plastic flow turbulence, but this pressure difference is approximately 15% to 1
Since it is approximately 7%, it is sufficient to select a value between these values as the value at the time of the pressure load.

According to the head of the present invention having the above structure, the gap between the outer periphery of the nibble loop and the inner periphery of the mouth of the die becomes almost equal when pressure is applied during extrusion, so that the uneven thickness of the extruded sheath can be made extremely small.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the structure of an extruder, FIG. 2 is a cross-sectional view of a sheath extruded by a conventional method, and FIGS. 3 and 4 are explanatory views of the extrusion head of the present invention. In the figure, 1 is a sheath, 2 is a die, 3 is a nipple,
Reference numeral 5 indicates a cable core, arrows A and A' indicate the moving direction of the extrusion ram, 2a indicates the inner circumference of the die, and 3a indicates the tip of the nipple.

Claims (1)

[Claims for Utility Model Registration] ■ In a metal sheath extruder in which the extruded material is pressed from two opposite directions perpendicular to the extrusion direction, when extrusion pressure is applied, the extruded material exit In this case, the outer periphery of the two-pullo part or the inner periphery of the die opening at the outlet of the extruded material is formed into an elliptical shape so that the gap between the outer periphery of the nipple opening and the inner periphery of the die opening is approximately equal over the entire circumference. Features: Extrusion head for metal sheath extruder. 2. The extruder for a metal sheath extruder according to claim 1, wherein the inner periphery of the die opening is circular, and the outer periphery of the nibbururo part is elliptical with a long axis parallel to the pressing direction of the extrusion ram. head. 3. The extruder for a metal sheath extruder according to claim 1, wherein the outer circumference of the nipple opening is circular, and the inner circumference of the die opening is elliptical with a short axis parallel to the pressing direction of the extrusion ram. head.