JPS58191133A - Mold - Google Patents

Abstract

PURPOSE:To improve an abrasion-resistance and intend a long life, absorbing the difference of a contraction due to the difference of a thermal expansion between a mold and a ceramic, by shaping the cavity opposing to a gate with a ceramic liner and making an elastic layer to lie between the liner and the mold. CONSTITUTION:A fixed force 1 is provided with the sprue 5 and the runner 6 which become a passage of the synthetic resin material supplied from an injection cylinder 4 and with the second sprue 7 which opens to the cavity 3 shaped at the contacting face of the fixed force 1 and a movable force 2 and the cavity 3 opposing to the gate 7a of the sprue 7 is shaped with a ceramic liner 8. Moreover, an elastic layer 9 is made to lie between the outer peripheral face of the liner 8 and the inner peripheral face of the movable force 2 to which the liner 8 is to be attached. Thereby, the impacting force in the contact of the movable force and the fixed force is mitigated.

Description

[Detailed description of the invention] The present invention relates to a mold.

Traditionally, molds for synthetic resin products were usually made of steel.

However, when used for molding plastics mixed with glass fibers, ferrite, etc., for example, there is a drawback in that severe wear occurs particularly at the gate part of the mold and the inner surface of the cavity, especially in areas where the flow of resin collides.

The present invention eliminates the drawbacks of the above-mentioned conventional examples, and improves wear resistance by configuring the cavity of the mold that faces the gate part, which is prone to wear, with a ceramic insert. An elastic layer is provided between the movable mold and the fixed mold to soften the impact when they come into contact with each other, and also to absorb the difference in shrinkage during molding due to the difference in temperature expansion coefficient between the two materials. The purpose is to achieve longer life.

An embodiment of the present invention will be described with reference to the drawings. A cavity 6 is formed in the opposing surfaces of the fixed mold 1 and the movable mold 2. The fixed mold 1 is provided with a sprue 5 serving as a passage for the synthetic resin material supplied from the injection cylinder 4, a runner 6, and a varnish blue 7 opening toward the cavity 3. The synthetic resin material molded in the present invention is a synthetic resin mixed with hard materials such as glass fiber and ferrite, so ceramic inserts are placed in areas where the synthetic resin comes into contact and is particularly prone to wear. ing. That is, the cavity 3 facing the gate part 7α of the varnish blue 7 is formed in the ceramic insert 8, and there is a space between the outer circumferential surface of the ceramic insert and the inner circumferential surface of the movable mold 2 to which the insert is mounted. has an elastic layer 9 interposed therebetween. The elastic layer 9 can be formed by, for example, adhering the ceramic insert 8 to the movable mold 2 using a rubber thread adhesive, or it can be formed by interposing an elastic sheet of rubber or the like between the two. It is also possible to form it by The elastic layer 9 is provided to prevent the ceramic insert from being damaged due to the impact force when the movable mold 2 is moved and brought into contact with the fixed mold 1 being directly received by the ceramic insert 8. The elastic force of the elastic layer 9 softens this and serves to protect the ceramic insert. Furthermore, the material of movable mold 2, a certain steel material, and ceramic have different thermal expansion coefficients, so when cooling during molding,
The steel material contracts faster and tries to press against the outer peripheral surface of the ceramic insert. The elastic layer 9 acts as a buffer against this suppressing force. Further, the part 5α of the sprue 5 that contacts the nozzle and the gate part 7α of the varnish blue 7 as well as the ceramic insert 10 and the ceramic sprue 12 are protruding bottles.

The present invention has such a structure, and the cavity to be filled with synthetic resin mixed with a hard material is formed of a ceramic insert, so it can sufficiently withstand friction during filling, and the cavity filled with synthetic resin mixed with a hard material can be sufficiently resistant to the friction during filling. Since the insert is attached, the impact force when the movable mold is brought into contact with the fixed mold can be softened.
It is possible to absorb the difference in shrinkage due to the difference in thermal expansion coefficient between the mold and the ceramic, thereby achieving a longer lifespan of the mold.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of the present invention. 1... Fixed type 2... Movable type 3
...Cavity 7a...Gate part 8...
... Ceramic insert 9 ... Elastic layer or above Applicant Seikosha Co., Ltd. Agent Patent attorney Tsutomu Mogami

Claims (1)

[Claims] The cavity of the mold facing the gate part is formed of a ceramic insert, and an elastic layer is interposed between the outer peripheral surface of the ceramic insert and the mold in which the ceramic insert is installed. Molding mold.