JPH09141413A - Structure for setting core pin for metallic mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily reuse and change a core pin without forming a gap between the core pin and a core setting hole. SOLUTION: The inner peripheral surface of the core setting hole 2 in a metallic mold 1 is formed as gently inclined state toward a cavity 4 of the metallic mold and also, the outer peripheral surface of the core pin 3 is formed into tapered shape to be made in fittably close contact with the inner peripheral surface of the core setting hole. The core pin is inserted and fitted to the core setting hole from the back surface side of the metallic mold, and this tip part is protruded to the cavity of the metallic mold, and the tip part of the core pin is worked into a prescribed shape to obtain a product forming part 3c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold core pin installation structure which is installed in a mold cavity in a fixed and protruding manner.

[0002]

2. Description of the Related Art A conventional core pin of this type has been fitted and installed in a core installation hole formed in a mold by a clearance fit. Therefore, a gap is generated between the core pin and the core installation hole. However, there was a problem that molten metal was inserted into the relevant portion during casting and casting burrs were generated.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and there is no gap between the core pin and the core installation hole, and the core pin An object of the present invention is to provide a mold core pin installation structure that can be easily reused and replaced.

[0004]

In order to achieve the above object, the core pin installation structure for a mold of the present invention has a structure in which the inner peripheral surface of the core core installation hole for fitting and mounting the core pin is made of metal. The core pin is formed in a gentle inclination toward the mold cavity, and the core pin is formed in a tapered shape whose outer peripheral surface fits closely to the inner peripheral surface of the core installation hole, and the core pin is mounted on the core. Insert and fit into the hole from the back side of the mold to project its tip into the mold cavity, and process the tip of the core pin projecting into the mold cavity into the required shape to form the product forming section. It is characterized by what was done.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. In the figure, reference numeral 1 denotes a mold in which a fitting mold 1b is integrally fitted in a main mold 1a.
The core pin 3 is fixedly installed in the core installation hole 2 formed in b so as to project into the mold cavity 4.

The core setting hole 2 is for fitting and setting the core pin 3, and the fitting mold 1b is formed in a circular shape from the back side thereof toward the mold cavity 4. On this occasion,
The inner peripheral surface thereof is formed in a gentle slope toward the mold cavity 4. When the core mounting hole 2 is formed, it can be formed by a wire cutting method, an electric discharge method, or a cutting method using a reamer.

Further, the core pin 3 is formed in a tapered shape having a circular cross-section whose outer peripheral surface conforms closely to the inner peripheral surface of the core installation hole 2. At this time, only the tapered portion 3a that fits closely to the inner peripheral surface of the core setting hole 2 is formed in a tapered shape, and is formed between the outer periphery of the fixing base 3b and the inner peripheral surface of the core mounting hole 2. May have a gap, and the tip portion protruding into the mold cavity 4 may not be formed in a tapered shape.

Then, the core pin 3 is inserted into the core installation hole 2 from the back side of the fitting mold 1b and pushed in to be fitted, and the outer peripheral surface of the core pin 3 is inserted into the core installation hole 2. The tip portion of the core pin 3 is projected into the mold cavity 4 while being brought into close contact with the peripheral surface. Then, insert the core pin 3 into a mold (fitting mold 1b).
With the core pin 3 projecting into the mold cavity 4, the tip portion of the core pin 3 protruding into the mold cavity 4 is machined into a desired shape by an electric discharge machining method or a cutting process using a reamer while being fitted into the core setting hole 2. It is not used as the forming portion 3c and is used for casting.

Further, the core pin 3 is made into a mold (fitting mold 1b).
As a means for fixing and installing in the core setting hole 2, as shown in FIG. 1, fixing with bolts 6 via a mounting plate 5 or
Alternatively, as shown in FIG. 2, it is conceivable to fix the female screw 7 formed on a part of the inner peripheral surface of the core setting hole 2 by screwing a set screw 8 therein. At this time, it is preferable to provide an appropriate gap 9 between the edge of the core setting hole 2 and the mounting plate 5 or the set screw 8. By doing so, even when the product forming portion 3c of the core pin 3 is reworked and the diameter of the taper portion 3b is reduced, it is possible to freely adjust the protrusion amount with respect to the mold cavity 4 to deal with it.

[0010]

EFFECTS OF THE INVENTION Since the die core pin installation structure of the present invention is constructed in this way, a gap is created between (the product forming portion of) the core pin and the die core installation hole. Disappears. Therefore, there is no fear that a casting burr will be generated in the portion at the time of casting.

Moreover, since the core pin is fitted in the core installation hole of the mold by so-called taper alignment, the product forming part of the core pin is seized or cracked to cause the product forming part to be damaged. Even in the case of reworking, it is possible to cope with the gap between the product forming portion of the core pin and the core installation hole of the mold by only slightly reducing the diameter of the core pin taper portion. Therefore, the core pin can be reused and the core pin can be easily replaced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of implementing the present invention.

FIG. 2 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1 ... Mold 1a ... Main mold 1b ... Fitting mold 2 ... Core installation hole 3 ... Core pin 3a ... Tapered part 3b ... Fixing base 3c ... Product forming part 4 ... Mold cavity 5 ... … Mounting plate 6 …… Bolt 7 …… Female screw 8 …… Set screw 9 …… Gap

Claims (1)

[Claims] 1. An inner peripheral surface of a core installation hole of a mold into which a core pin is fitted and installed is formed to have a gentle inclination toward a mold cavity, and the core pin has an outer peripheral surface having the above-mentioned middle shape. Formed in a tapered shape that fits closely with the inner peripheral surface of the child installation hole, insert the core pin into the core installation hole from the back side of the mold and project the tip end portion into the mold cavity, A core pin installation structure for a mold, wherein a tip portion of the core pin protruding into the mold cavity is processed into a required shape to form a product forming portion.