JPS6254538A - Manufacture of piercing billet for manufacturing pipe by hot extrusion - Google Patents

Abstract

PURPOSE:To reduce the thickness deviation factor in a pierced billet and an extruded tube stock by setting the tip side of the piercing billet for hot extrusion in a metallic tube stock manufacturing process, to the lower side in case of hot piercing of the billet. CONSTITUTION:A guide hole 2A of a small circular hole is provided in the center of a billet 1A, and also an end face working 3A is performed to one end. Subsequently, at the time of a hot extrusion, the end face working 3A side is set to the lower side and inserted into a container 4A. Next, from the upper side, an upset cone 5A makes a cone part by a pre-upset at the side opposite to the side of a surface working 3A and an R working 3A'. Subsequently, a lubricating glass is spread to the cone part, and thereafter, a piercing tool 7A is made to pass through from the upper side where the cone part exists, to the lower side where the surface working 3A and the R working 3A' exist, and a pierced billet 9A having an inner hole 8A is obtained. Next, the side of the end face working 3A and the R working 3A' of the pierced billet 9A is set to the tip and the hot extrusion is executed.

Description

[Detailed Description of the Invention] (Industrial Application Field) The technique of using glass during extrusion of metal and causing the glass melted by the heat of the billet to act as a lubricant during extrusion is known as the Eugene Séjourne method. . The present invention is directed to a method of manufacturing a hollow cylindrical perforated billet for hot extrusion of metal tubes in the hot extrusion manufacturing method by Eugene Sejour.

(Prior Art) Conventional techniques for producing the above-mentioned perforated billet include a method in which a hollow hole of a desired diameter is punched into a solid billet by machine cutting, and a method in which a hollow hole of a desired diameter is punched through a heated concrete billet using a press. There is a method in which a hollow hole of a required diameter is bored by drilling the hole.

The latter billet perforation method according to Eugene Sejoux is carried out as follows.

(i) First, as shown in Fig. 5, a small inner guide hole /l/ (2) is provided in the center of the billet (1), and dead ends of the billet as shown in Fig. 9 that occur during hot extrusion are removed. As shown in FIG. 10, the end surface processing (3) is applied to prevent the zone fP) from adversely affecting the surface quality of the extruded raw pipe, and the upper end channel 77 is placed with the end surface processing (3) side facing upward.
- (4) into the mantenna (4) provided.

(i) Next, as shown in FIG. 6, press the upsent cone (5) and form the cone 8 (6) using a preamplifier set.

((Turn) After sprinkling lubricating glass on the cone part (6).

As shown in Figure 7, the inner hole (8) is drilled by the drilling tool (7).
penetrate. (9) is the perforated billet thus obtained, and αQ is the die.

Hot extrusion is the end face processing (3) of this perforated billet (9)
Do this with the top side as the tip.

(Problems to be Solved by the Invention) It goes without saying that the method of manufacturing perforated billets by mechanical cutting involves a lot of loss.

The latter billet perforation method also causes the following problems in the former gC conventional technology. That is, when inserting the K billet (1) into the container (4), the side where the end face processing (3) has been performed is placed on the upper side. However, the container for drilling (4)
In order to easily take out the perforated billet (9) after drilling, the upper inner diameter is larger than the lower inner diameter, so the clearance between the container and the billet on the upper side is large, and the billet 7 Since the bottom ff1I is cut as is (diagonally cut), the billet can be tilted, and the lateral force derived from the strong axial force causes the billet to tilt, and the core of the rond of the drilling tool (7) and the core of the billet are tilted. may shift. In particular, in the conventional technology, the end face processing (3) is performed on the top of the billet.

Since the inclination of the billet can become large, misalignment is likely to occur. Therefore, during the preamplifier setting step (i), as shown in FIGS. 5 and 6, the cone portion (6
) is drilled at a position that is offset from the center of the billet, and during the drilling process (@), the inner hole (8) is opened at a position that is offset from the center of the billet, as seen in Figure 7, and the uneven thickness becomes large. Due to 'L, the uneven thickness of the t'P raw tube also increased.

Another example of a perforated billet that is largely affected by uneven thickness is as shown in Figure 8. Some hole billets (9) have a large uneven thickness on the upper side and become smaller toward the bottom. In the prior art, the upper side of the perforated billet with large thickness deviation is used as the tip side during hot extrusion tube manufacturing, so that the tendency of thickness deviation of the extruded raw pipe becomes large. In addition, Paris (2) (to) occurs.◎The present invention eliminates the above-mentioned 8M point of the conventional billet drilling method, and the small 72mm point of 1m thickness is solved. The object of the present invention is to provide a perforated billet manufacturing method for obtaining a perforated billet and an extruded raw tube.

(Means for Solving the Problems 1 Effects and Examples) To achieve the above object 1. The method for producing a perforated billet for hot extrusion pipe production according to the present invention provides molten glass lubrication in the process of producing metal wood pipes by hot extrusion. In order to produce a hollow cylindrical perforated billet for deep extrusion by the method, the perforation is performed so that the tip of the perforated billet during hot extrusion becomes the lower side during hot perforation of the billet. Features.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below by way of examples with reference to the accompanying drawings. FIG. 1 shows the state before setting the preamplifier according to the first embodiment of the present invention.

(IA) with a small circular guide hole (2
A), and when extruding with end face processing (3A) applied to one end so that this side becomes the tip during hot extrusion, a dead zone of the billet will occur and the surface quality of the extruded raw pipe will be adversely affected. Try to prevent this from happening. In particular, in the present invention, the container (4
A) Insert into.

In this way, from the upper side, the amplifier set cone (5A) is formed.A cone part is created by preamplifier on the side opposite to the side of the surface treatment (5A).

After sprinkling lubricating glass on this cone part, a drilling tool (7A) is passed through it from the upper side where the cone part is located to the lower side where the surface treatment (5A) is located, and it has an inner hole (aA) and a 9-hole billet (9A). shall be. This perforated billet has a small center diameter of the inner hole (aA) and a small thickness unevenness.

In this method, if the die (10A) has a tapered part σ1 on the outside as shown in the conventional technique shown in FIG. During drilling, the shape of the end-to-end machining (3A) was destroyed, and a crack 0, as shown in Figure 7, was generated on the outer peripheral end surface of the perforated fillet 7, which had a negative impact on the coating quality of the extruded raw pipe! ! ! Since there is a fear that the surface may be affected by 1, the shape is made to have a flat surface as shown in FIG.

Then, hot extrusion is performed using the lower side of the perforated pyrene (9A), which has been subjected to the end face processing (6A), as the tip.

By this method, it was possible to significantly reduce the thickness deviation in perforated billets and extruded raw tubes.

FIG. 6 shows the penetrating shape of the drilling tool in the second embodiment of the present invention. In the second embodiment, a die (10E) having a protrusion (b) in the center is used, and a preamplifier set and nine holes are made in the same manner as in the first embodiment, resulting in a perforated billet as shown in FIG. 9B) is produced. In other respects, this embodiment is equivalent to the first embodiment, so equivalent parts are indicated by the same reference numerals in the drawings, and redundant explanation will be omitted. Since the perforated billet of this embodiment has a sufficient billet ampscent during extrusion pipe manufacturing, it is effective in further reducing the thickness deviation of the extruded raw pipe.

(Effects of the Invention) According to the present invention, the thickness unevenness of the extruded raw pipe is 1.
It can be reduced by 5-2%.

According to the present invention, the lower side of the tip of the perforated billet,
That is, as shown in FIG. 4, a burr CL1 is formed in the inner hole at the tip during extrusion pipe production, but it has been confirmed that this does not affect the surface quality of the extruded raw pipe in any way.

4 Explanation of Drawings FIG. 1 is a longitudinal side view showing the state before the start of preamplification of the first embodiment of the method of the present invention, FIG. 2 is a longitudinal side view showing the state after drilling is completed, and FIG. The figure is a longitudinal side view showing the state after drilling is completed in the second embodiment of the method of the present invention, FIG. 4 is a longitudinal side view of the drilling fin 7 obtained in the second embodiment, and FIG. A longitudinal side view showing a preamplifier set start letter in one of the perforated billet manufacturing methods, FIG. 6 is a preamplifier set completion letter g! Af: A longitudinal sectional side view showing Fig. 7 is a longitudinal sectional side view showing the completed perforation state, Fig. 8 is a longitudinal sectional side view showing the state of uneven thickness of another perforated billet according to the prior art, and Fig. 9 is the extrusion product. FIG. 10 is a side view of the extruded tube.

(1) (IA)... Billet, (2) (2A)... Guide hole, (3) (3A)... End face processing, (4) (
4A)... Container, (4)... Chamfer-1 (5)
(5A)... Upset cone, (6) (6A)...
Cone part, (7) (7A)...Drilling tool, (8) (8A
... Inner hole, (9) (9) (9A) (9B) ... Perforated billet, α @ (10A) (10B) ... Die, α
6.Chi, lower part, (+11..protrusion, ++2113
··Paris.

Claims (3)

[Claims] (1) In the manufacturing process of metal tubes by hot extrusion method,
In order to manufacture a hollow cylindrical perforated billet for hot extrusion using the molten glass lubrication method, the perforation is performed so that the side that will be the tip of the perforated billet during hot extrusion will be the lower side during hot perforation of the billet. 1. A method for producing a perforated billet for hot extrusion pipe making, characterized by carrying out the following steps. (2) The method for manufacturing a perforated billet according to claim 1, wherein hot perforation is performed using a die having a flat surface. (3) The method for manufacturing a perforated billet according to claim 1, wherein hot perforation is carried out using a die having a protrusion in the center.