JPH0329572B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a molding die for compression molding a cylindrical molded product having a lining without deforming the lining, which is attached to the mold as an insert. .

[Prior art]

In molded products having a lining, the lining is usually made of a more flexible material than the molded product body.

When molding such a molded product, a method is often used in which a lining is molded in advance and the lining is used as an insert to mold the molded product body.

Cylindrical molded products are molded by fitting the lining into the core in advance, but depending on the material, the lining may deform when heated to the molding temperature and when pressurized. No effective method for preventing this has yet been found, and the product is manufactured using a completely different method, such as joining the lining and the molded product body.

[Purpose of the invention]

An object of the present invention is to prevent deformation of the lining during molding in a compression molding die for molding a cylindrical molded product having such a flexible lining.

The present invention provides a compression molding mold for a cylindrical molded product having a lining, in which a lower mold, a lower mold core, and an upper mold constitute a cavity, and the lower mold core has a step corresponding to the lining fitted on its outer periphery. provided,
Furthermore, in order to fix the lining, a presser cylinder that comes into contact with the upper end surface of the lining when fitted to the upper part of the lower die;
The present invention also relates to a compression molding die characterized in that it has a presser plate fixed to the upper surface of the lower mold core with bolts or the like to fix the presser cylinder.

FIG. 1 is a sectional view of a compression mold of the present invention in which a cylindrical molded product having a lining is being molded, and FIG. 2 is a partially enlarged view of FIG. 1.

The mold cavity is composed of a lower mold 1, a lower mold core 2, and an upper mold 3. Here, the molded product body A
is molded. The lower mold core 2 is provided with a step 4 corresponding to the shape of the lining B on the mold side.

A presser cylinder 5 that comes into contact with the upper end surface of the lining A to fix the lining is provided at the fitting part of the lower mold core with the upper mold, and a presser plate 6 that fixes the presser cylinder is attached to the upper surface of the lower mold core by screws or the like. Fixed.

Next, a process of molding a cylindrical molded product having a lining using the mold of the present invention will be described.

As shown in FIG. 3, the lining B is set on the lower die core 2, the presser cylinder 5 is fitted onto the lower die core 2, the presser plate 6 is placed on top of the lining B, and the bolts 7 are placed on top of the lining B.
etc. to fix it to the lower mold core 2.

Next, as shown in FIG. 4, a predetermined amount of resin C is poured into the space formed by the lower mold 1 and the lower mold core 2, and the upper mold 3 is lowered and the molds are clamped.

In this way, the molded state as shown in FIG. 1 is achieved. After molding, the presser plate 6 is removed, the presser cylinder 5 is protruded with an ejector pin (not shown), and the molded product B integrated with the lining is taken out by an appropriate method.

Note that the step on the inner surface of the lining of the molded product is removed by cutting after the molded product is taken out.

〔Effect of the invention〕

If the lining is simply set on the lower mold core, the lining may be deformed by the molding pressure, or resin may enter between the lower mold core and the lining.
The pressure had the disadvantage of deforming the lining, but in the mold of the present invention, the upper part of the lining is fixed by the step of the lower mold core and the presser cylinder, so deformation of the lining can be prevented.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the compression molding mold of the present invention in a state of molding, Fig. 2 is a partially enlarged view of Fig. 1, and Figs. 3 and 4 are the compression molding mold of the present invention. FIG. 3 is a cross-sectional view of a mold showing the molding process, with FIG. 3 showing the mold in an open state and FIG. 4 showing a state in which resin is poured.

Claims (1)

[Claims] 1. In a compression molding mold for a cylindrical molded product having a lining, a lower mold, a lower mold core, and an upper mold constitute a cavity, and the lower mold core is provided with a step corresponding to the lining fitted to its outer periphery, It is further characterized by having a presser cylinder that comes into contact with the upper end surface of the lining when fitted to the upper part of the lower mold to fix the lining, and a presser plate that is fixed to the upper surface of the lower mold core with bolts or the like to fix the presser cylinder. compression molding mold.