JPH06297077A - Mold for forming lost foam pattern - Google Patents

Abstract

PURPOSE:To integrally form a lost foam pattern by using a freely attachable and detachable auxiliary mold in order to improve the dimensional accuracy of the lost foam pattern. CONSTITUTION:The base of a recessed part 2c of a moving mold 2 is provided with a magnet 5, a knock pin 6 and an air vent 7 and the auxiliary mold 3 is provided with a magnetic metal 9 and a knock hole 10. The magnet 5 attracts the magnetic metal 9 and the auxiliary mold 3 engages with the recessed part 2 when the knock pin 6 is inserted into the knock hole 10, by which the auxiliary mold 3 is mounted in the moving mold 2. Pressurizing air is blown from the air vent 7 to the auxiliary mold 3, by which the auxiliary mold 3 is disengaged from the moving mold 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a mold for molding a vanishing model used in a vanishing model casting method.

[0002]

2. Description of the Related Art A vanishing model is generally integrally molded by injecting and foaming a synthetic resin material into a molding die, but a complicated part such as a part which cannot be die-cut is bonded with an adhesive after molding the main body model. (Japanese Patent Application Laid-Open No. 4-127935, page 2, lines 15 to 19). For example, as shown in FIG. 4, the disappearance model 23 having a cylindrical recess 22 and a wedge-shaped recess 21 protruding in the radial direction from the bottom of the recess 22 along the circular bottom surface 22a includes a disappearance model body 23a and a recessed model. The disappearing model piece 23b extending from the upper surface of the place 21 to the surface of the disappearing model body 23a is bonded with an adhesive to be molded.

[0003]

When the vanishing model body 23a and the vanishing model piece 23b are bonded as shown in FIG. There is a problem that the bonded position between the disappearance model body 23a and the disappearance model piece 23b is likely to be displaced, and it is difficult to obtain a disappearance model having desired dimensional accuracy. Therefore, the present invention has been made to solve such a problem, and the dimensional accuracy of a disappearing model having a cylindrical recess and a wedge-shaped recess protruding radially from the bottom of the recess along the circular bottom surface. The purpose is to improve.

[0004]

DISCLOSURE OF THE INVENTION The disappearing model forming die of the present invention comprises a fixed die having a concave portion, a movable die having a cylindrical convex portion, and a detachable wedge-shaped auxiliary die. It is characterized in that it is made to extend in the radial direction from the edge portion of the cylindrical convex portion of the mold along the circular end surface.

[0005]

When the movable mold is opened after foam molding, the disappearing model is left in the fixed mold, the auxiliary mold is left in the disappearing model, and the disappearing model is released from the fixed mold. Remove the mold from within the vanishing model.

[0006]

1 to 3 show a vanishing model molding die according to the present invention, which comprises a fixed die 1 having a concave portion 1a, a movable die 2 having a cylindrical convex portion 2a, and a detachable wedge-shaped auxiliary die 3. Prepare,
When the auxiliary die 3 is provided so as to extend in the radial direction from the end edge portion of the cylindrical protrusion 2a along the circular end surface 2b, when the movable die 2 having the auxiliary die 3 and the fixed die 1 are clamped. The cavity 4 is formed. The fixed mold 1 and the movable mold 2 are molds using a general mold, and the auxiliary mold 3 has a thermal conductivity of 70 to 2
It is formed of a non-magnetic metal such as brass or aluminum alloy of 00 Kcal / mh ° C.

The attaching / detaching means of the auxiliary die 3 will be described with reference to FIG. A concave portion 2c is provided on the end edge of the cylindrical convex portion 2a of the movable die 2 so that the auxiliary die 3 and the concave portion 2c can be engaged in concave and convex, and the bottom surface of the concave portion 2c has a holding force of 10 to 20 gf / c.
The m ² magnet 5 is embedded, a knock pin 6 is provided upright, and an air vent 7 is further provided.

The air vent 7 is connected to a communication hole 8 penetrating through the movable mold 2, and pressurized air is blown to the auxiliary mold 3 through the air vent 7 so that the auxiliary mold 3 can be detached from the movable mold 2. .

A magnetic metal 9 is embedded in a portion of the auxiliary die 3 facing the bottom surface of the recess 2C, and a knock hole 10 is formed therein, so that the knock pin 6 is engaged when the movable die 2 and the auxiliary die 3 are engaged with each other. The knock pin 6 and the knock hole 1 are inserted into the knock hole 10 so that the magnetic metal 9 is locked to the magnet 5.
0, the magnet 5 and the magnetic metal 9 are respectively arranged, and the auxiliary mold 3 is formed so as to be freely mounted on the movable mold.

Next, the operation will be described with reference to FIG. When the auxiliary die 3 is preheated to 60 to 80 ° C. and then the knock pin 6 is inserted into the knock hole 10, the magnetic metal 9 is attracted to the magnet 5 and the auxiliary die 3 engages with the recess 2c, so that the auxiliary die 3
Is attached to a predetermined portion of the movable mold 2. Next, movable type 2
Is moved forward (downward in FIG. 3), the movable mold 2 and the fixed mold 1 are clamped, the foaming synthetic resin material is injected into the cavity 4 to foam, and the disappearance model 11 is molded. After that, when the mold opening is performed while blowing pressurized air into the communication hole 8 from the outside,
Pressurized air blown out from the air vent 7 presses the auxiliary mold 3 to cause the disappearing model 11 to remain in the fixed mold 1, and the auxiliary mold 3 to remain in the disappearing model 11 so that the movable mold 2 retracts to the standby position (Fig. 3 upward direction). Next, disappearance model 1
After the mold 1 is released from the fixed mold 1, the auxiliary mold 3 is taken out from the disappearance model 11 to obtain the integrally disappeared disappearance model 11 having good dimensional accuracy.

[0011]

According to the present invention, a vanishing model having a cylindrical recess and a wedge-shaped recess projecting radially from the bottom of the recess along the circular bottom surface can be easily integrally formed, and the vanishing model can be easily formed. Has good dimensional accuracy and contributes greatly to the reduction of the manufacturing process of the disappearance model and the improvement of quality.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a clamped state of a vanishing model molding die of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is a cross-sectional view showing a conventional bonded disappearing model.

[Explanation of symbols]

 1 Fixed type 1a Recessed part 2 Movable type 2a Cylindrical convex part 2b Circular end face 3 Auxiliary type

Claims (1)

[Claims] 1. A fixed die having a concave portion, a movable die having a columnar convex portion, and a detachable wedge-shaped auxiliary die, the auxiliary die being provided from an end edge portion of the cylindrical convex portion of the movable die to a circular end surface. Disappearance model forming die characterized in that it is extended in the radial direction along.