JPH0474806A - Apparatus and method for extrusion-compacting deformed material - Google Patents

Abstract

PURPOSE:To execute extrusion-compacting of raw material for sintering a deformed material with a simple apparatus at a low cost by packing powder raw material, which is plasticized by adding binder, into a devided metallic mold for compacting having the prescribed cross sectional shape of penetrating hole through a connector. CONSTITUTION:The apparatus used for extrusion-compacting of the raw material for sintering, changeable in the cross sectional shape at the position in the longitudinal direction, is constituted of an extrusion machine 1 composed of a cylinder 1a and a screw 1b, a connector 2, metallic mold 3 and cap 4. The connector 2 has a conical shaped hole mold 2a and a hole 2b having a diameter smaller than the min. cross sectional outside diameter of the body to be compacted. The metallic mold 3 is composed of divided pieces 3a, 3b having a hole mold 3d changeable in the cross sectional shape. At the time of extruding the plastically kneaded body of metal powder by running the above extrusion machine 1, the kneaded body is packed into the hole mold shape in order. After completing the packing, the cap 4 is taken off and after slide-shifting the divided pieces 3a, 3b, the green compact is extruded to the prescribed length.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention applies an extrusion molding method to extrusion of a profiled material in which a molded article with a complex shape whose cross-sectional shape changes depending on the longitudinal position is obtained. This invention relates to a molding device and method.

[Conventional technology]

Articles formed by conventional extrusion molding methods are determined by the exit shape of the die and always have a constant cross-sectional shape with respect to longitudinal position.

In response, the present applicant applied an extrusion molding method to develop an assembly extrusion die and extrusion molding method for forming a profiled material whose cross-sectional shape changes depending on the position in the longitudinal direction.
I proposed it to No. 1. In the assembly extrusion die for forming the profiled material and its forming method, extrusion molding is performed in a taper or step shape that becomes smaller toward the outlet side of the die.

In addition, various shaped materials are molded using the injection molding method, which involves temporarily injecting a fixed amount of plastic material into a sealed mold, applying pressure inside the mold, and then molding the plastic material into the mold. I plan to harden it internally.

[Problem to be solved by the invention]

As mentioned above, the cross-sectional shape of the molded body obtained by the conventional extrusion molding method is constant with respect to the longitudinal position, so when producing a profiled material from an extrusion molded material, green processing or annealing is required. Since it is necessary to perform processing later, there are also problems in terms of yield and processing man-hours. In addition, in the case of forming a profiled material, the cross-sectional shape in the longitudinal direction has a tapered or stepped structure that becomes smaller toward the exit side of the die. As a result, its scope of application was limited. On the other hand, in molded products obtained by injection molding, the molding space is continuous with the flow paths of the sprue, runners, etc. of the mold, so some of the material to be molded remains in these flow paths after molding, resulting in molding problems. Separation from the body is required. Since the separated sprues, runners, etc. are hardened in the mold, they must be depopulated again in order to be reused. In addition, jetting is likely to occur, so internal defects are likely to occur. Furthermore, the mold used for molding is large in size compared to the size of the molded product in terms of pressure resistance, and the structure is complicated and expensive because it requires flow paths such as sprues and runners.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an apparatus and method for extrusion-molding a sintering material of a profile whose cross-sectional shape changes depending on its longitudinal position using a simple apparatus and at low cost.

The sintering material used in the present invention is a material that is formed into a product through a sintering process after molding, and is generally called green.

[Means to solve the problem]

The present invention relates to an extrusion molding apparatus for a sintering material whose cross-sectional shape changes depending on the position in the longitudinal direction. A die having a hole shape smaller than the minimum cross-sectional outer diameter of the object to be molded at the tip position, a through-hole attached to the die corresponding to the cross-sectional shape, and a divided mold, which allows the mold to be opened and closed. Addition of a binder to an extrusion molding device for a profiled material characterized by a sliding mechanism for moving the material and a cap attached to a molding die, and a method for extruding a material for sintering whose cross-sectional shape changes depending on the longitudinal position. The plasticized powder raw material is placed in a divided molding mold having a through hole corresponding to the cross-sectional shape, and a conical hole mold and a hole smaller than the minimum cross-sectional outside diameter of the molded object at the tip thereof. This is an extrusion molding method for a profiled material, characterized in that after filling the molded material through a die having a mold, the molding mold is opened by a slide mechanism, and then the molded object is taken out by extrusion.

[Effect]

The present invention is suitable for products having a cross-sectional shape that changes depending on the longitudinal position, such as a stepped shaft shape.

The molding die is a split mold having a sliding mechanism, and the inner surface shape matches the desired molding shape. Thereby, by releasing the assembled state and extruding it from the mold part, it is possible to take out the molded object inside without damaging it.

〔Example〕

Next, the present invention will be explained in detail with reference to Examples. FIG. 1 is a diagram for explaining one embodiment of the present invention, and the device used for molding is an extruder 12 consisting of a cylinder la and a screw 1b. Molding mold 3. and a cap 4. The mouthpiece 2 has a conical hole 2a and a hole 2b having a smaller diameter than the minimum cross-sectional outer diameter of the object to be molded, and is fixed to the extruder 1. The molding die 3 has a hole 3d whose cross-sectional shape changes depending on the position in the longitudinal direction, and the dividing piece 3 has a dividing plane perpendicular to the plane of the paper.
a and 3b, and is attached to the lower side of the cap holder so that it can reciprocate between predetermined positions by being connected to a rod 3C and driven by a cylinder that is a part of a slide mechanism (not shown). has a small hole for degassing and is attached to the bottom of the mold.

When the divided pieces 3a and 3b are fixed at the positions shown in FIG. 1 by the above-mentioned device and the extruder 1 is driven to extrude a plastic kneaded body of metal powder (not shown), a cap 4 is placed on the lower side of the molding die 3.
Therefore, shearing and compression are performed in the molding die 3, and the kneaded material is sequentially filled into the hole shape from the bottom of the molding die and molded. When filling is completed, the extrusion molding machine 1 is stopped, the cap 4 is removed, and the divided pieces 3a and 3b are moved in the direction of the arrow 5 in Fig. 2 by the slide mechanism, and then extruded to a predetermined length as shown in Fig. 3. After removing the molded body as shown in FIG. 4 by cutting, the divided pieces 3a are obtained.

3b and repeat the above cycle again.

The molded body taken out was dried, treated with a binder, and then sintered, but no abnormality was observed in each process.6 [Effects of the Invention] As described above, according to the present invention, the conventional extrusion molding method It is possible to form irregularly shaped materials of any size and shape at longitudinal positions where it was previously impossible.

On the other hand, compared to the injection molding method, the molding pressure applied to the mold is low at less than 100 kg/cm", so the mold can be made smaller and lighter. Also, since there is no need for flow channels such as runners and sprues, it is possible to The structure of the mold is simple, and molds can be produced at low cost.Furthermore, because internal defects are less likely to occur due to shearing and compression molding, it is possible to provide shaped materials with stable quality at low cost, making it extremely useful in industry. It is highly effective.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the extrusion molding apparatus for a profiled material according to the present invention, and Fig. 2 shows a divided piece 3a after molding. FIG. 3 is a cross-sectional view of the molded body extruded, and FIG. 4 is a view showing the product according to the above embodiment. 1: Extruder, 1a rainbow cylinder, 1b: screw, 2: mouthpiece, 2a: hole mold, 3: molding mold, 3 a, 3 b: dividing piece, 3d: hole mold, 3C: rod, 4: cap first Figure 3 Figure 1, Substitute A, v7 5 Rest Figure 4

Claims (1)

[Claims] 1. An extrusion molding device for a sintering material whose cross-sectional shape changes depending on the position in the longitudinal direction, an extruder that pressurizes and supplies a material to be molded, and a conical hole attached to the extruder. A die, a die having a hole shape smaller than the minimum cross-sectional outer diameter of the object to be molded at the extrusion tip position thereof, a divided molding die having a through hole corresponding to the cross-sectional shape attached to the die, and the molding die. 1. An extrusion molding device for a profiled material, characterized by comprising a slide mechanism for opening and closing a mold, and a cap attached to the mold. 2. In an extrusion molding method for a sintering material whose cross-sectional shape changes depending on the position in the longitudinal direction, a powder raw material that has been plasticized by adding a binder is molded into a molded mold that is divided into pieces having through holes corresponding to the cross-sectional shape. After filling the mold through a mouthpiece having a conical hole and a hole at its tip position smaller than the minimum cross-sectional outer diameter of the object to be molded, the mold is opened by a slide mechanism, and then extrusion is performed. A method for extrusion molding of a profiled material, characterized by taking out a molded object.