JPH02247040A - Die apparatus for casting - Google Patents

Abstract

PURPOSE:To continuously operate casting work by constituting dies for casting of outer die and core supporting base for forming cavity together with the outer die and the core for forming undercut part of a product assembled as attachable/detachable to the core supporting base. CONSTITUTION:In the die apparatus, by fitting as slidable the core supporting base 4 fixed to a cylinder rod 3 in a hydraulic cylinder into cavity hole 2 in the outer die 1, the cavity 5 is formed, and a core assembling body 7 consisting of the core supporting base 4 and a staying core 6 is constituted therein, and in the staying core 6, projecting part 10 forming the undercut part 11 at the product 8 side is arranged. When the poured molten metal in the cavity 5 solidifies, the staying core 6 is taken out of the cavity 5 as cast, and after being separated from the product 8, this is assembled to the core supporting base 4, and again, this process can be repeated and casting manufacturing efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a casting mold device used in pressure casting methods and the like.

Conventional Technology For example, in order to reduce the weight of pistons used in high-speed automobile engines without sacrificing strength, the skirt portion is made completely thin, and reinforcing ribs are provided on the inner circumferential surface of the skirt portion. A so-called undercut portion is formed in the upper part of this. Therefore, in a mold apparatus used for casting such a piston, if the core mold is an integral piece, a situation arises in which the core mold gets caught on the ribs and cannot be released from the mold. Therefore, in order to prevent such a situation, the core mold is assembled into multiple divided molds, and when the mold is released, the core mold is released while still being cast into the product (piston), and then the core mold is removed. The product is disassembled and removed from the product, and the product and core mold are separated.

To continue the casting operation, the separated core molds are assembled, placed in the mold, and the entire core mold is preheated before pouring (e.g. 15th
Volume 2, No. 38-39 (February 1, 1975: Published by Nikkan Kogyo Shimbun)).

Incidentally, preheating the entire mold including the core mold is an essential operation to prevent casting defects.

Problems to be Solved by the Invention In such a conventional example, it takes time to disassemble and reassemble the core mold, especially when continuous casting work is performed, and the core mold is roughly cooled after being released from the mold. The entire mold had to be reheated, which was an obstacle to improving production efficiency.

Means for Solving the Problems The casting mold device of the present invention comprises: an outer mold; a core support that is engaged with the outer mold and forms a cavity together with the outer mold;
It is characterized by comprising a placing core that is detachably assembled to the core support base and forms an undercut portion in the product.

During mold release, only the placed core, which is cast into the product, is taken out of the cavity.

Example Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a sectional view of a casting mold device showing an embodiment of the present invention. In this figure, l is an outer mold, and this outer mold l has a cavity hole 2 formed therein that passes through it in the vertical direction.

A core support 4 fixed to a cylinder rod 3 of a hydraulic cylinder is slidably fitted into the cavity hole 2 of the outer mold I to form a cavity 5. A pair of placed cores 6.6 are assembled to the core support base 4 to form a core assembly 7. In addition, these core support stands 4
The engagement surface with the cores 6 and 6 has an axial direction (upward direction in the figure).
The opening is sloped so that the placing core 6 can be attached to and removed from the core support base 4 in the axial direction (upward in the figure). The placing core 6 is formed with a protrusion 10 for forming ribs 9 on the inner circumferential surface of the product (cast product) 8. This protruding portion 10 forms an undercut portion 11 on the product 8 side. On the other hand, on the top of outer mold 1,
A pressurizing punch 12 is provided, which is supported so as to be movable up and down by a hydraulic cylinder or the like (not shown). This pressure punch 12 is
After pouring the molten metal into the cavity 5, it is inserted into the cavity hole 2 and the molten metal is pressurized.

In order to carry out casting work using the mold device with the above structure, first align the mold device to the condition shown in Figure 1, and then install the entire mold device in order to prevent casting defects on the outer surface of the product. 1.7 and the pressure punch 12 at a predetermined temperature (for example, 150
Heat (preheat) to 8C to 400°C. Thereafter, molten metal is poured into the cavity 5. Thereafter, the molten metal in the cavity 5 is immediately pressurized by the pressure punch 12. still,
This pressurized state is maintained until the molten metal solidifies. When the molten metal in the cavity 5 solidifies, the pressurizing punch 12 returns to the position shown in FIG. 1, and the cylinder rod 3 then rises to push the product 8 out of the cavity 5 (upward in the axial direction). At this time, the core support base 4 is fixed to the cylinder rod 3.

On the other hand, the placed core 6 is separated from the core support base 4 by an ejector pin (not shown), taken out of the cavity 5 while still being cast into the product 8 (see Figure 2), and then separated from the product 8. Ru. In addition, in order to continue the casting work, after assembling the placed core 6 separated from the product 8 to the core support base 4,
Casting is performed according to the steps described above.

According to the above embodiment, even when the product 8 is taken out from the cavity 5 (so-called demolding), the core support base 4, which occupies most of the volume of the core assembly 7, is not removed from the apparatus. Therefore, if the casting operation is to be continued, only the placed core 6 taken out of the cavity 5 together with the product 8 needs to be reheated.

Therefore, the time required for reheating (preheating) the mold device can be shortened. Furthermore, when the casting work is restarted or continued after the product 8 has been released from the mold, the core assembly 7 can be reassembled simply by assembling the placed core 6 into the core support base 4 in the cavity 5. I can do it.

Therefore, compared to the conventional example, the time required to reassemble the core assembly 7 can be shortened, and together with the above-mentioned shortening of the reheating time, production efficiency can be significantly improved.

Note that the product 8 may be taken out from below the outer mold 1.
In this case, if the pressurizing punch 12 and the cylinder rod 3 are linked and moved downward at the same time, the product 8
can be taken out in a short time.

Effects of the Invention As described above, the present invention includes an outer mold, a core support base that is engaged with the outer mold and forms a cavity together with the outer mold,
It consists of a core that is detachably assembled to this core support base and forms an undercut part in the product, so it can be used easily when demolding. Only the core is removed from the facility together with the product. Therefore, if the casting operation is to be continued, only the placed core needs to be assembled to the core support stand, and only the placed core needs to be reheated. Therefore, the time for assembling the core can be shortened, and the time for reheating the mold device can be shortened, so that the efficiency of casting work can be significantly improved.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a casting mold device showing an embodiment of the present invention, and Fig. 2 is a sectional view of the same mold device and product during mold release. - Core support stand, 5... cavity,
6. Placed core, 8. Product, 11. Undercut part. Figure 1, Nakate 11: After undercut? Diagram

Claims (1)

[Claims] (1) An outer mold, a core support that is engaged with the outer mold to form a cavity together with the outer mold, and a core support that is removably assembled to the core support to form an undercut in the product. A casting mold device comprising a placing core.