JPS62282761A - Die for die casting using insert core - Google Patents

Abstract

PURPOSE:To extend the life of a die by disposing plural pieces of deflashing groove parts to the outside periphery of the part of an insert core to be fitted to a movable core. CONSTITUTION:Plural pieces of the groove parts 18a-18e are formed and disposed to the outside periphery of the fitting surface of the insert core 2 to be fitted to the movable core 1. The flashes stuck to the fitting part 4 intrude into the groove parts 18a-18b of the core 2 and are ejected integrally with the core 2 to the outside of the fitting part 4 at the time of ejecting a product B from the core 1 by ejector pins 5 after die casting of the product B. No flashes are, therefore, formed to the fitting part 4 and the need for the deflashing operation of the fitting part 4 after the casting is eliminated by the above-mentioned method. The generation of the flaws based on the deflashing operation is thus eliminated and the life of the die is consideraby extended.

Description

[Detailed Description of the Invention] Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to the structure of a core placed in a die-casting mold, and is suitable for casting an outer case of an automobile transmission. It is something that is used.

(Prior Art) The outer case of the automobile transmission according to the present invention is die-cast by the method shown in FIGS. 5 to 9.

That is, in Fig. 5, A is a die-casting machine,
A fixed core 7 is assembled in a fixed outer frame 6, a movable core 1 is assembled in a movable outer frame 8, and a cavity 9 is formed by combining the movable core and the fixed core.

In the movable core 1, a placing core 2 is inserted and held in a fitting portion 4 with the movable core 1 in order to cast out the bag-shaped undercut portion 3 of the cavity 9. 10 is a ladle, 11 is a molten metal such as aluminum alloy, 12 is a plunger, 13
is a sleeve.

In the above-described apparatus, the plunger 12 moves forward to fill the cavity with molten metal and die cast the product, which is the outer case of the transmission.

(Problems to be Solved by the Invention) However, the conventional die casting described above has the following problems. This will be explained with reference to FIGS. 6 to 9.

Figure 6 is an enlarged view of the process of holding the movable core 2.
There are mutually fitting parts 4a and 4b between the core 2 and the core 2. This is to make it easier to attach the core to the fitting part 4, so the gap is 0.5mm.
~0.2w is provided. When molten metal is forced into the cavity 9 at high pressure and high speed during casting, the molten metal enters the gaps 4a and 4b, resulting in a bulging phenomenon.

Figure 7 shows post-casting mold 7. A situation is shown in which the movable core 1 is in an open state and the fixed core 7 is covered with particles 14.

FIG. 8 shows a situation in which the product 15 is pushed out from the movable core 1 by the extrusion bottle 5 in the next step;
is removed from the fitting part 4 together with the product. A gap 16 corresponding to the gap is left in the fitting portion 4.

In Fig. 9, when installing the next core 2, the fitting part 4
There is a problem in that the burr 16 left behind prevents the insertion of the insert core 2 from entering the fitting part, making it difficult to install it easily, and the insert core cannot be inserted at all unless the operator removes this burr. .

A technical object of the present invention is to provide a die-casting mold having a core in which no particles adhere to the fitting portion of the core.

[Structure of the invention]

(Means for Solving the Problem) A means for solving the above technical problem is that a fixed core is assembled in a fixed outer frame, a movable core is assembled in a movable outer frame, and the movable core and the fixed core are assembled. A die-casting device in which the molds are fitted together to form a cavity, and a molded core is fitted and held in the movable core for casting by casting out an undercut recess in the cavity. This uses a placing core in which a plurality of grooves are carved into the outer periphery of the fitting part where the core is inserted into the movable core.

(Operation) The technical means operates as follows. In other words, since there is a groove on the outer circumferential surface of the core that fits into the movable core, even if the weld field enters the mating part during casting and becomes sticky, it will also infiltrate and adhere to the groove on the surface of the core. Even if the core is removed, nothing will remain in the fitting part of the movable core (all of it will stick to the surface of the core and be carried out. Therefore, when the core is attached to the movable core next time, , there is no need to deburr the fitting portion at all.

(Example) Examples will be described below.

1 to 4 are explanatory diagrams of this embodiment, and numbers 1 to 17 for explanation refer to the above.

B in FIG. 1 is a transmission for a light vehicle, which has an undercut portion 3.

2 in Figure 2 is a positioning core with a groove 18 on the outer periphery that fits into the movable core.
There are a, 18b, .... 2a is a convex portion of the core which corresponds to an undercut portion.

FIG. 3 shows the transmission case B extruded from the movable core 1 by the casting push-out pin 5 in the die-casting machine A.
18b, . . . and are carried out of the fitting part together with the core 2, and the fitting part is completely free of burrs.

In FIG. 4, the splint 16 attached to the core 2 can be easily removed by bagasse in the direction of the arrow in order to remove it from the core 2.

〔Effect of the invention〕

The present invention has the following effects. In other words, since no firmness remains on the fitting part of the movable core into which the placing core fits, there is no need to remove the burrs from the fitting part, and therefore, there is no possibility of scratches on the fitting part due to the burr removal work. As a result, the life of the mold is greatly extended.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an automobile transmission, Fig. 2 is an external perspective view of a core placed in this embodiment, Fig. 3 is a sectional view of the product removal process in a die-casting machine according to this embodiment, and Fig. 4 Figure 5 is an explanatory diagram of the work of removing tension from the core, Figures 5 to 9 are explanatory diagrams of the conventional example, Figure 5 is an explanatory diagram before casting, Figure 6 is an explanatory diagram of the casting process, and Figure 7 is an explanatory diagram of the casting process. 8 is an explanatory diagram of the process of moving the movable core, FIG. 8 is an explanatory diagram of the process of taking out the product, and FIG. 9 is an explanatory diagram of the process of inserting the placing core into the fitting portion. DESCRIPTION OF SYMBOLS 1... Movable core, 2... Placed core, 3... Undercut part, 4... Fitting part, 6... Fixed type outer frame, 7...
...Fixed core, 8...Movable outer frame, 9...Cavity

Claims (1)

[Claims] A fixed core is assembled into a fixed outer frame, a movable core is assembled into a movable outer frame, the movable core and the fixed core are brought together to form a cavity, and an undercut of the cavity is formed in the movable core. In a die-casting mold in which a placing core is fitted and held in the movable core for casting, a groove is carved into the outer periphery of the fitting part inserted into the movable core of the placing core. Type.