JPH0233952Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial field of application The invention relates to a multi-cavity casting mold for simultaneously casting multiple products such as pistons, and is particularly concerned with molds that can be molded into molds due to thermal deformation when molten metal is poured into the mold. This is to prevent eccentricity and uneven thickness.

BACKGROUND ART This type of casting mold generally has semi-cylindrical grooves 4, 4 and 4 grooves formed on opposite sides of the parting surfaces 3 of a pair of molds (split molds) 1 and 2, respectively, as shown in FIGS. 4 and 5. 5, and by aligning the positions of these semi-cylindrical grooves 4, 5, cylindrical product molding parts 6, 7 are formed and placed on the base 8, and on both sides of the base 8. The attached cores 9 and 10 and the top cores 11 and 1 attached to both sides of the molds 1 and 2
2 to form cavities 13 and 14, and molten metal 17 is injected into the cavities 13 and 14 from a runner 15 and a sprue 16 connected to these cavities 13 and 14 to cast a product 18 such as a piston. ing. In the figure, 19 is a core ring, 20 is a core holder, and 21 and 22 are keys and key grooves that connect and support the molds 1 and 2 on the base 8 in a matched state.

Problems to be solved by the invention By the way, regarding the conventional casting mold mentioned above, the fourth problem is
~ As shown in FIG.
0 is set, pour the molten metal 17 and make the product 1.
8, there was a problem in that the product 18 had eccentricity and uneven thickness, that is, a thin part 18a and a thick part 18b, as shown in FIG.

This is because when molten metal 17 is poured into mold 1,
2 is thermally deformed so as to warp as shown in FIG. 7, whereas the base 8 is hardly thermally deformed.
This is because the position is shifted to the outside of the center-to-center pitch B of 10.

The present invention has been made for the purpose of solving the above-mentioned conventional problems and providing a casting mold that does not cause uneven thickness.

Means for Solving the Problems The center-to-center pitch of the product molding section and the center-to-center pitch of the core are made different, and the center-to-center pitch of the product molding section is offset to the inside of the center-to-center pitch of the core.

Effect Since the center-to-center pitch of the product molding part is offset to the inside of the center-to-center pitch of the core, the mold, which is affected by heat, is thermally deformed more than the base due to the injection of molten metal, and the center-to-center pitch of the product molding part is offset to the outside. When the product is in the deviated or stretched state, the center-to-center pitch of the product molding portion closely matches the center-to-center pitch of the core to prevent eccentricity of the product.

EXAMPLE Next, a casting mold according to the present invention will be explained with reference to FIGS. 1 to 3. 1 and 2 are a pair of front and rear molds; 3 is a parting surface of the molds 1 and 2; 4 and 5 are semi-cylindrical grooves formed at opposing positions on both left and right sides of the parting surface 3 of the molds 1 and 2; , 7 is a cylindrical product forming part formed by aligning the grooves 4 and 5, 8 is a base on which the pair of molds 1 and 2 are mounted in a matched state, 9 and 10. 11 and 12 are cores attached to the left and right sides of the base 8, and top cores 11 and 12 are attached to the left and right sides of the molds 1 and 2, respectively. Cavities 13 and 14 for molding a product (piston) 18 are formed in the molding parts 6 and 7. The center-to-center pitch A of the product forming sections 6 and 7 is different from the center-to-center pitch B of the cores 9 and 10, and the center-to-center pitch A of the product forming sections 6 and 7 is different from the center-to-center pitch B of the cores 9 and 10. It is offset inside the center-to-center pitch B, so that when the molds 1 and 2 are thermally deformed, the center-to-center pitch A of the product molding parts 6 and 7 and the center-to-center pitch B of the cores 9 and 10 match. It's summery. 15 is a runner connected to cavities 13 and 14, 16 is a sprue connected to runner 15,
The molten metal 17 is injected from the sprue 16 to form a plurality of
It is possible to simultaneously cast several products 18, that is, pistons. 19 is a core ring,
The core ring 19 is in a state in which the center-to-center pitch B of the cores 9 and 10 is offset outward from the center-to-center pitch A of the product forming sections 6 and 7 (product forming sections 6 and 7).
Considering the center-to-center pitch A of the product molding parts 6 and 7 as a reference, the product molding parts 6 and 7 are attached to the base 8 in a state in which the center-to-center pitch A is offset to the inside of the center-to-center pitch B of the cores 9 and 10. 20 is a core holder;
Reference numerals 21 and 22 are key connecting portions that connect and support the molds 1 and 2 on the base 8 in a matched state.

Since the multi-cavity casting mold of the embodiment has the above-described configuration, when the molds 1 and 2 are thermally deformed by pouring the molten metal 17, the center-to-center pitch A of the product molding parts 6 and 7 becomes in a so-called elongated state. Tenako 9,10
The product molding parts 6 and 7 coincide with the center-to-center pitch B of
Product 1 with cores 9 and 10 set in the center of
8 will be cast, and as a result, a piston with substantially uniform wall thickness over the entire circumference without uneven thickness will be cast. In the embodiment shown in the drawings, a piston is cast as an example, but the product to be cast is not limited to a piston, but can be widely applied to products cast using a core.

Effects of the Invention As explained above, in the present invention, a plurality of product molding parts 6 and 7 are formed on opposite sides of the parting surfaces 3 of a pair of molds 1 and 2, respectively, and the product molding parts 6 and 7 are placed on the base 8. At the same time, cavities 13 and 14 are formed in the product molding parts 6 and 7 by cores 9 and 10 attached to both sides of the base 8 and top cores 11 and 12 attached to both sides of the molds 1 and 2. In the multi-cavity casting mold made of
The center-to-center pitch of the cores 9 and 10 is offset to the outside with respect to the center-to-center pitch of If the molds 1 and 2, which are affected by heat, are thermally deformed more than the base 8 due to the injection of the molten metal 17, the product molding parts 6 and 7
The pitch between the centers of the cores 9 and 10 coincides with the pitch between the centers of the cores 9 and 10, so that the product 18 can be cast without eccentricity or uneven thickness.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention; Fig. 2 is a plan view of a pair of molds joined together and the top core removed; Fig. 2 is a sectional view of the top core attached; and Fig. 3 is a plan view of the embodiment of the invention. A cross-sectional view of the product made with the mold, Figure 4 is a plan view of the conventional example, Figure 5 is a cross-sectional view,
FIG. 6 is a sectional view of a product made with a conventional mold, and FIG. 7 is a plan view showing problems with the conventional mold. 1, 2...Mold, 3...Parting surface,
4, 5... Groove, 6, 7... Product molding section, 8... Base, 9, 10... Core, 11, 12... Top core, 13, 14... Cavity, 15... Runway, 16 ... sprue, 17 ... molten metal, 18 ... product.

Claims (1)

[Scope of utility model registration request] A plurality of product forming parts 6, 7 are provided on opposite sides of the parting surfaces 3 of the pair of molds 1, 2, respectively.
cores 9 and 10 attached to both sides of the base 8 and top cores 1 attached to both sides of the molds 1 and 2.
1 and 12, in a multi-cavity casting mold in which cavities 13 and 14 are formed in the product molding parts 6 and 7, the center-to-center pitch of the product molding parts 6 and 7 and the core 9, 10. A multi-cavity casting mold characterized in that the pitch between the centers of the product molding parts 6 and 7 is offset to the inside of the pitch between the centers of the cores 9 and 10.