JP2006026672A - Porthole die and extruding method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a porthole die for extruding a hollow material by which a smooth extruded section can be obtained constantly without causing air inclusion due to the deformation of a remaining extruded material irrespective of a cutting condition or an extruding condition, and while preventing a phenomenon that the remaining extruded material R is drawn when a container and a stem are retracted, and to provide an extruding method using the porthole die. <P>SOLUTION: A void having the diameter not less than that of the circumscribed circle of the port group is arranged in a rear face of the porthole die to extrude a hollow metal work so as to surround the port group, and an inner circumferential wall surface of the void is expanded forward of the porthole die. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a porthole die for extruding a hollow material of metal, particularly aluminum (including an aluminum alloy, hereinafter the same), and an extrusion method using the porthole die.

  The aluminum hollow material is extruded using a porthole die 1 shown in FIGS. The porthole die 1 is a male mold 2 having a mandrel portion 5 and a port group 7 including a plurality of ports 6, 6, 6, 6 (four in FIG. 4) provided in the circumferential direction of the mandrel portion 5. And a female mold 3 in which the mandrel part 5 of the male mold 2 is fitted and combined. The ports 6, 6, 6, 6 of the male mold 2 are separated by bridges 8, 8, 8, 8, and the mandrel part 5 is supported at the base end part of the bridges 8, 8, 8, 8.

  As shown in FIG. 3, the extrusion molding is performed by placing a container C on the rear surface of the porthole die 1, loading a billet B in the container C and pressurizing with a stem S, and the mandrel portion of the male mold 2. The hollow material E is extruded from between the bearing portion 9 of 5 and the bearing portion 10 of the female die 3.

  In such extrusion molding, usually, after extrusion of one billet, the container C is retracted, and as shown in FIG. 4, the residual D left protruding from the rear surface 11 of the port-hole die 1 is removed. A continuous extrusion process is performed by cutting with the shear 14, pressing a billet against the cut surface, pressing and unifying the billet.

  However, when shearing the remaining part D, the residual extruded material R remaining in the port 6 is plastically deformed due to the load from above by the shear 14 to cause metal dripping, as shown in FIGS. A gap G is generated above each port 6, 6, 6, 6. If the splicing is performed in this state, air is mixed into the gap G and the air is confined in the crimping portion, causing surface defects such as blisters in the extruded hollow material and cracking in the subsequent process due to insufficient crimping. .

  In order to solve this problem, as shown in FIGS. 6 to 7, a plate 15 having a through-hole 16 having a diameter equal to or larger than the outer diameter d (see FIG. 4) of the port group 7 is used as a port. Placed on the rear surface 11 of the hole die 1, and after extrusion, the residual extruded material R is also left in the recess 16 having a larger cross-sectional area to increase the rigidity at the shear cut surface, and the gap G due to plastic deformation of the residual extruded material R There has been proposed a technique for preventing the occurrence of the above (see Patent Document 1).

Although this method can obtain a considerable void prevention effect, depending on the cutting conditions, the residual extruded material R may be slightly deformed and air entrainment may not be completely prevented. Depending on the extrusion conditions, depending on the extrusion conditions, when the container and stem are retracted, the residual extruded material R remaining in the recess 16 is pulled back together and remains. A phenomenon that a part of the extruded material R comes off is also experienced.
Japanese Patent Laid-Open No. 2002-1422

  The present invention has been made in order to solve the above-mentioned problems, and the purpose thereof is to prevent the residual extruded material from being deformed and causing air entrainment regardless of any cutting conditions and extrusion conditions. Further, a phenomenon that the residual extruded material R is removed when the container and the stem are retracted is prevented, and a port hole die for hollow material extrusion that can always obtain a smooth retained cut surface and the port hole die are provided. It is to provide an extrusion method to be used.

  A port hole die according to claim 1 for achieving the above object is a port hole die for extruding a metal hollow material, and has a diameter larger than a circumscribed circle of a port group on a rear surface of the port hole die. A space having a hole is attached so as to surround the port group, and an inner peripheral wall surface of the space is expanded toward the front of the port hole die.

  The port hole die according to claim 2 is the port hole die according to claim 1, wherein the inner peripheral wall surface of the space is in relation to the central axis of the container for loading the billet for extrusion disposed on the rear surface of the port hole die. It is characterized by spreading at an angle of 5 to 40 degrees toward the front.

  The port hole die according to claim 3 is characterized in that, in claim 1 or 2, the depth to the rear surface of the port hole die in the space is 5 to 25% of the billet loading port diameter of the container.

  According to a fourth aspect of the present invention, there is provided an extrusion processing method in which a hollow material is extruded using the porthole die according to any one of the first to third aspects, and the unfinished portion is formed by an end surface of an opening provided on the rear surface of the porthole die. After cutting, the process of pressing and pressing the billet against the cut surface is repeated.

  According to the present invention, regardless of the cutting conditions and extrusion conditions, the residual extruded material is not deformed and air entrainment does not occur, and the residual extruded material R comes off when the container and stem are retracted. There are provided a port hole die for extrusion molding of a hollow material and an extrusion method using the port hole die, which can be prevented and can always obtain a smooth remaining cut surface.

  An embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol was attached | subjected to the same member as the past. In the porthole die of the present invention, as shown in FIGS. 1 and 2, a void 12 having a diameter d2 equal to or larger than the diameter d1 of the circumscribed circle of the port group 7 is formed on the rear surface 11 of the porthole die 1 as a port group. It is attached so as to surround.

  As a form in which the void 12 is attached so as to surround the port group, as shown in FIG. 1, the void 12 is formed by arranging the annular member 4 having a through opening on the rear surface 11 of the port hole die 1. Alternatively, the void 12 may be formed by providing the annular member 4 as an integral structure on the rear surface of the male mold 2 of the porthole die 1. The diameter of the void 12 at the portion where the annular member 4 is in contact with the rear surface 11 of the porthole die 1 is defined as a diameter d2.

  In the present invention, the inner peripheral wall surface 13 of the void 12 is widened toward the front (extrusion direction) of the porthole die 1, and the expansion angle α is arranged on the rear surface of the porthole die 1. It is preferable that the angle is 5 to 40 degrees toward the front of the porthole die 1 with respect to the central axis XX of the container C for loading the extruded billet B. About the expansion of the inner peripheral wall surface 13 of the space 12, the same effect can be acquired also as a step shape other than a taper shape.

  When the expansion angle of the inner peripheral wall surface 13 of the void 12 is less than 5 °, when the container C and the stem S are retracted, the residual extruded material in the void 12 is easily pulled out, and the inner peripheral wall surface 13 of the void 12 is easily removed. If the spread angle exceeds 40 °, the contact area between the rear surface of the port hole die (the rear surface of the male die 2) and the annular member 4 decreases, and there is a risk that the extruded material may leak from the die during extrusion.

  The depth of the void 12 to the rear surface 11 of the porthole die 1, that is, the thickness of the annular member 4 is preferably 5 to 25% of the loading diameter of the billet B of the container C. If it is less than 5%, when the container C and the stem S are retracted, the residual extruded material in the void 12 is easily pulled out, and if it exceeds 25%, the friction between the extruded material and the annular member increases during extrusion. Therefore, an excessive extrusion pressure is required.

  According to the present invention, after the extrusion is finished, when the remaining portion D is sheared along the end surface of the space 12 (the end surface of the annular member 4), the space that expands in a taper shape toward the extrusion direction has a deformation resistance. As it increases, it becomes a resistance against slipping out of the remaining extruded material when the container moves backward, and a smooth cut surface is obtained. When a billet is pressed against the cut surface, it is crimped and integrated without generating voids, and a hollow extruded material without defects is obtained. Can be manufactured.

  Examples of the present invention will be described below. This example is one embodiment of the present invention, and the present invention is not limited to this example.

Example 1
A billet of JIS6063 aluminum alloy was extruded into a tube having an outer diameter of 30 mm and an inner diameter of 26 mm by a 6-inch extrusion press having a container inner diameter of 160 mm. The used port hole die (see FIGS. 1 and 2) has four ports, and the diameter d1 of the circumscribed circle of the port group is 120 mm. An annular member having a thickness of 20 mm is attached to the rear surface of the port hole, the diameter of the end surface of the space where the annular member is provided is 120 mm, and the inner peripheral wall surface of the space is relative to the central axis XX of the container It spreads at an angle of 20 ° in the extrusion direction.

  The billet is heated to 500 ° C to perform extrusion. After the extrusion is completed, the container is retracted and the unsettled portion is shear cut. The cut surface is smooth, and the billet is pressed against the cut surface for 20 times. Repeatedly, no blister defects or poor crimping defects were found in the extruded tubing.

Comparative Example 1
In Example 1, the inner peripheral wall surface of the void is not expanded in the extrusion direction with respect to the central axis XX of the container, and the implementation is performed except that a port hole die formed parallel to the extrusion direction is used. In the same manner as in Example 1, extrusion molding was repeated 20 times of splicing. As a result, generation of blister defects and defective crimping defects was observed in 1/5 of the products.

It is sectional drawing which shows the state which is cutting the pressing residue D after it extrudes using the porthole die of this invention. It is AA sectional drawing of FIG. It is sectional drawing which shows the state which mounted | wore the extrusion port with the conventional porthole die. FIG. 4 is a cross-sectional view showing a state in which a press residue D is cut after being extruded using the port hole die of FIG. 3. It is BB sectional drawing of FIG. It is sectional drawing which shows the state which cuts the remaining part D after extrusion using the conventional porthole die. It is a perspective view which shows the plate arrange | positioned at the porthole die of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Porthole die 2 Male type 3 Female type 4 Annular member 5 Mandrel part 6 Port 7 Port group 8 Bridge 9 Male type bearing part 10 Female type bearing part 11 Rear surface of port hole die (rear side of male type)
12 Cavity 13 Inner wall surface of Cavity 14 Shear 15 Plate 16 Recess C Container B Billet E Hollow extruded material R Residual extruded material D Remaining G Gap d1 Diameter of circumscribed circle of port group d2 The diameter of the bottom, the diameter of the space where the annular member 4 contacts the rear surface 11 of the porthole die)
α Spreading angle of the inner wall of the void in the direction of extrusion

Claims (4)

A port hole die for extruding a metal hollow material, wherein a void having a diameter larger than a circumscribed circle of the port group is attached to the rear surface of the port hole die so as to surround the port group. The port hole die is characterized in that the inner peripheral wall surface of the station extends toward the front of the port hole die. The inner peripheral wall surface of the space expands at an angle of 5 to 40 ° toward the front of the port hole die with respect to the central axis of the container for loading the billet for extrusion disposed on the rear surface of the port hole die. The porthole die according to claim 1, wherein 3. The port hole die according to claim 1, wherein a depth of the empty port hole die to a rear surface is 5 to 25% of a billet loading diameter of the container. A hollow material is extruded using the porthole die according to any one of claims 1 to 3, and after cutting off the press residue at an end surface of a space attached to the rear surface of the porthole die, a billet is formed on the cut surface. An extrusion method characterized by repeating the step of pressing and joining.

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