JPH05261508A - Die casting method and die casting machine used in die casting - Google Patents

Abstract

PURPOSE:To provide a die casting method and a die casting device where the deburring process after die casting is unnecessary, the manufacturing process of die casting part can be simplified and the required time is reduced, and the manufacturing cost is reduced. CONSTITUTION:A projecting part 10E is formed to a part of a gear case 10 which is formed by dies such as a fixed die 1, a first movable die 2 and a second movable die 3 in the die casting, the projecting part 10E is damaged by the contact of the first movable die 2 in the drawing-out operation, and generation of burrs 11 on the projecting part 10E is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding method and a molding apparatus used in the molding method, and is particularly effective when applied to a molding method in which burrs may occur and a molding apparatus used in the molding method. Related technology.

[0002]

2. Description of the Related Art For example, a gear case 10 of a worm reduction gear motor as shown in FIGS. 5 and 6 is manufactured by die casting.

The gear case 10 produced by such die-cast molding is provided with a worm housing portion 10A and a wheel housing portion 10B, and a meshing portion 10C where the worm and the wheel mesh with each other is formed between both housing portions. It is said that.

[0004]

By the way, in the gear case 10 as a molded product as described above, burrs 11 are apt to occur at the opening edges of the meshing portions 10C of the worm housing portion 10A and the wheel housing portion 10B.

Therefore, a step of removing the burr 11 is required after the molding, which hinders simplification and shortening of the manufacturing process and reduction of the manufacturing cost.

An object of the present invention is to provide a molding method and a molding method thereof, which do not require a step of removing burrs after molding, and can simplify and shorten the manufacturing process of a molded product and reduce the manufacturing cost. It is to provide a molding apparatus used.

The above and other objects and novel features of the present invention will be apparent from the accompanying drawings of this specification.

[0008]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, according to the molding method of the present invention, a convex portion is formed on a part of a molded product which is molded by a mold, and the convex portion is damaged due to contact of the mold during extraction of the mold or the molded product. As a result, the occurrence of burrs on the convex portion is prevented.

Further, the molding apparatus of the present invention has a structure in which a concave portion for molding a convex portion which is lost due to contact of the mold during the extraction of the mold or the molded product is formed on the extraction surface of the mold. is there.

[0011]

According to the above-described molding method of the present invention, the convex portion formed on a part of the molded product at the time of molding is damaged by the contact of the mold during the extraction of the mold or the molded product, and the burrs of the convex portion are burred. Since the occurrence of burrs is prevented, the step of removing burrs after molding is unnecessary, and the manufacturing process of the molded product can be simplified or shortened, and the manufacturing cost can be reduced.

Further, according to the above-described molding apparatus of the present invention, the concave portion for molding the convex portion into a part of the molded product at the time of molding is formed on the extraction surface of the mold, and the convex portion generated by the concave portion is the mold or the mold. Since the occurrence of burrs at the convex parts due to contact with the mold when the molded product is pulled out is prevented, the step of removing the burr after molding is unnecessary, and the manufacturing process of the molded product is simplified and shortened. Therefore, it can be effectively used in a wide range as a molding device capable of reducing the manufacturing cost.

[0013]

Embodiment 1 FIG. 1 is a cross-sectional view showing a molding apparatus according to an embodiment of the present invention during molding, FIG. 2 is a cross-sectional view showing the molding apparatus withdrawing a mold, and FIG. FIG.

The molding method and the molding apparatus used in the molding method in this embodiment are applied to a gear case 10 of a worm reduction gear motor manufactured by die casting as shown in FIGS. template)
And a first movable mold 2 (mold) which is housed in the space 1A for molding the wheel housing portion of the fixed mold 1 so as to be displaceable along its axial direction (horizontal direction in the plane of FIG. 1), and fixed The mold 1 is provided with a second movable mold 3 (mold) which is housed in the worm housing part molding space 1B so as to be displaceable along its axial direction (the direction perpendicular to the paper surface in FIG. 1).

As shown in FIG. 1, the wheel accommodating part molding space 1A and the worm accommodating part molding space 1B are formed in a substantially cylindrical shape by a fixed mold 1 and a first movable mold 2.

By the way, in the gear case 10 molded by the conventional molding apparatus, burrs are apt to be generated at the opening edge 10D at the boundary between the wheel accommodating part molding space 1A and the worm accommodating part molding space 1B. There is.

In the molding apparatus of this embodiment, in order to solve such a problem, a concave portion 2A is formed in the extraction surface of the first movable mold 2 at a portion of the opening edge 10D facing the molding portion. Has been done. Then, the convex portion 10E that is damaged by the contact of the first movable mold 2 at the time of extraction is formed by the concave portion 2A of the first movable mold 2.

Next, the operation of this embodiment will be described.

First, as shown in FIG. 1, the first movable mold 2 is housed in the wheel housing part molding space 1A of the fixed mold 1, and the second movable mold 3 is housed in the worm housing part molding space 1B. After housing, the predetermined molten metal is poured into the molding space 4 formed by the fixed mold 1, the first movable mold 2, and the second movable mold 3.

At the time of molding by injecting this molten metal, the first
The convex portion 10E along the opening edge 10D of the gear case 10 is molded by the concave portion 2A of the movable mold 2.

Next, after the molten metal has been cooled and solidified, the second movable mold 3 is displaced along the axial direction of the worm accommodating portion molding space 1B and extracted from the worm accommodating portion molding space 1B. 2 After removing the movable mold 3,
The first movable mold 2 is displaced along the axial direction of the wheel housing part molding space 1A of the fixed mold 1 and pulled out from the wheel housing part molding space 1A.

When the first movable mold 2 is extracted from the wheel accommodating portion molding space 1A, the inner peripheral surface of the concave portion 2A comes into contact with the convex portion 10E of the gear case 10 as shown in FIG. 10E is chipped off, and the projection 10E is chipped off to prevent the occurrence of burrs on the opening edge 10D of the gear case 10.

As described above, according to this embodiment, unlike the gear case 10 molded by the conventional molding method and molding apparatus, the occurrence of burrs at the opening edge 10D of the gear case 10 is prevented, and therefore, the molding is performed. The process of removing burrs later is unnecessary, simplifying and shortening the manufacturing process of molded products,
It is possible to reduce the manufacturing cost.

[0024]

[Embodiment 2] FIG. 4 is a sectional view showing a molding apparatus according to another embodiment of the present invention during molding.

In the second embodiment, unlike the above-described first embodiment, the fixed mold 1 is located on the right side of FIG. 4, and the first movable mold 2 is located on the left side of FIG.

In the molding apparatus of the second embodiment, the recess 2A is formed on the fixed mold 1 side, and the ejector pin 12 for pulling out the gear case 10 from the fixed mold 1 side is provided.

In the molding apparatus of the second embodiment having such a structure, first, as shown in FIG. 4, the fixed mold 1 is housed in the wheel housing part molding space 1A of the first movable mold 2. Further, after the second movable mold 3 is accommodated in the worm accommodating portion molding space 1B, a predetermined melting is performed in the molding space 4 formed by the fixed mold 1, the first movable mold 2 and the second movable mold 3. Inject metal.

At the time of molding by injecting the molten metal, the opening edge 10 of the gear case 10 is formed by the recess 2A of the fixed mold 1.
The convex portion 10E along D is molded.

Next, after the molten metal has been cooled and solidified, the second movable mold 3 is displaced along the axial direction of the worm accommodating portion molding space 1B and extracted from the worm accommodating portion molding space 1B. 2 After removing the movable mold 3,
The first movable mold 2 is displaced along the axial direction of the wheel accommodating part molding space 1A to extract it from the wheel accommodating part molding space 1A, and the ejector pin 12 extracts the gear case 10 from the fixed mold 1 side.

When the gear case 10 is pulled out by the ejector pin 12, the inner peripheral surface of the recess 2A is the gear case 1
The convex edge 10E is damaged by contacting the convex portion 10E of 0, and the opening edge 10 of the gear case 10 is broken by the defective convex portion 10E.
The occurrence of burr of D is prevented.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the first and second embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

For example, in the above-described embodiment, the gear case 1 of the worm reduction gear motor in which the molding method and the molding apparatus of the present invention are manufactured by die casting.
However, the molding method and the molding apparatus of the present invention are not limited to the application of the gear case 10 as described above, and can be widely applied to the molding method and the molding apparatus for other molded articles. Is possible.

[0033]

The effects obtained by the typical ones of the inventions disclosed in this application will be briefly described as follows.
It is as follows.

(1) According to the molding method of the present invention, the convex portion formed on a part of the molded product at the time of molding is damaged by the contact of the mold at the time of extraction of the mold or the molded product and Since burrs are prevented from being generated, the step of removing burrs after molding is unnecessary, and the manufacturing process of the molded product can be simplified or shortened, and the manufacturing cost can be reduced.

(2) According to the molding apparatus of the present invention, the concave portion for molding the convex portion into a part of the molded product at the time of molding is formed on the extraction surface of the mold, and the convex portion generated by this concave portion is molded or molded. Since the occurrence of burrs in the convex portion due to chipping due to contact with the mold during product removal is prevented, the step of removing burrs after molding is unnecessary, simplifying and shortening the manufacturing process of molded products, It can be effectively used in a wide range as a molding device capable of reducing the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a molding apparatus according to an embodiment of the present invention during molding.

FIG. 2 is a cross-sectional view showing when the mold of the molding apparatus is removed.

FIG. 3 is an image view showing a state of extracting the mold.

FIG. 4 is a cross-sectional view showing a molding apparatus according to another embodiment of the present invention during molding.

FIG. 5 is a perspective view showing a gear case molded by a conventional molding method and molding apparatus.

6 is a cross-sectional view taken along the line VV of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed mold 1A Wheel housing part molding space 1B Worm housing part molding space 2 1st movable mold 2A recessed part 3 2nd movable mold 4 Molding space 10 Gear case 10A Worm housing part 10B Wheel housing part 10C Engagement part 10D Opening Edge 10E Convex part 11 Burr 12 Ejector pin

Claims (2)

[Claims] 1. A convex portion is formed on a part of a molded product at the time of molding by a mold, and the convex portion is damaged due to contact of the mold at the time of removing the mold or the molded product, and the burr of the convex portion is burred. A molding method characterized in that the occurrence of 2. A molding apparatus, wherein a concave portion for molding a convex portion that is damaged by contact of the mold when the mold or the molded product is extracted is formed on the extraction surface of the mold.