JPH031236Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a so-called multi-piece molding die in which molten rubber or resin material is supplied to a plurality of cavities through channels branching from a sprue.

In this type of mold, the distance from the sprue to each cavity is different, and therefore the length of the flow path to each cavity is different. A larger cavity allows for a higher flow rate of material to be fed. For this reason, the diameter of the gate of each cavity is changed so that a uniform amount of material is supplied to each cavity at a predetermined time.
However, it is actually extremely difficult to precisely adjust the amount of material flowing in by machining the gate diameter of each cavity, and it is not possible to adjust the amount of material flowing in each case depending on the molding conditions. If there is an imbalance in the amount of material flowing into each cavity, problems such as sink marks and burrs will occur.

Therefore, the purpose of the present invention is to provide a molding die that can timely and easily adjust the flow rate of material in the flow path to each cavity. Position the part of the flow path near the cavity inlet on the dividing surface of the mold,
A hole with a bottom that opens into the flow path is provided in one of the molds in the vicinity of the inflow port, a flow rate adjustment member is fitted into this hole, and the height of the protrusion of the flow rate adjustment member into the flow path is adjusted. This achieves the above objectives.

Hereinafter, the present invention will be explained with reference to illustrated embodiments.

As shown in FIG. 1, a synthetic resin molding mold 1 consists of an upper mold 1a, a middle mold 1b, and a lower mold 1c.
Six cavities 2 are formed in parallel between the lower mold 1c and the lower mold 1c. A sprue 3 serving as a resin material inlet into the mold is formed in the center of the upper mold 1a, and the sprue 3 communicates with each cavity 2 through an E-shaped branch runner 4 for distributing and supplying the resin material. The tip of the E-shaped runner 4 is divided into two directions and is located on the dividing surface of the middle mold 1b and the lower mold 1c, and a gate 5 is provided at the material inlet to each cavity 2.
is formed.

The runner 4 is provided with a material flow rate adjusting means 7 in the vicinity of the gate formed on the dividing surface, and the means is formed on the lower die 1c from the runner 4 in a direction perpendicular to this, as shown in FIG. Bottom screw hole 71
and a screw member 72 screwed into this.

By the way, in the above-described multiple molding molds, due to the difference in the distance between the sprue 3 and each cavity 2, that is, the path length of the runner 4 reaching each cavity 2, the distance between each cavity 2 in a predetermined time The amount of material supplied becomes uneven. For this reason, for example, the cross-sectional area of the gate 5 of each cavity 2 is processed and adjusted so that the cross-sectional area of the gate further away from the sprue 3 is made larger, and the cross-sectional area of the gate closer to the sprue is made smaller. It is actually difficult to adjust the flow rate to a desired level.

Therefore, in the molding die of this embodiment, each gate 5
A screw member 72 is provided on the lower die 1c in close proximity to the runner 4 of the screw member 72 depending on the degree of screwing.
The height of the protrusion is adjusted to adjust the flow rate of the material.

In the above embodiment, a screw member was used as the flow rate adjustment member, but a rod-shaped member, a plate-shaped member, etc. may also be used and fitted into the hole.
The flow rate can be adjusted by appropriately replacing a large number of flow rate adjustment members with different lengths.

Therefore, according to the mold of the present invention, the material flow rate of the runner reaching each cavity can be finely adjusted to the desired amount using simple means, and product shortages due to uneven material supply to each cavity can be avoided. In addition to preventing the generation of dust, it is possible to obtain a homogeneous product.

Furthermore, since the flow rate adjusting member is provided on the dividing surface of the mold, the material around the adjusting member is removed every time molding is performed. Therefore, the protrusion of the adjusting member prevents the molten material from staying in the flow path, causing the material to deteriorate due to thermal history, and causing this deteriorated material to flow into the cavity.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which FIG. 1 is a cross-sectional view of a molding die, and FIG. 2 is a view showing the main parts of the mold shown in FIG. 1. 1...Molding mold, 2...Cavity, 3...
Sprue, 4...flow path, 72...screw member (flow rate adjustment member).

Claims (1)

[Scope of utility model registration request] In a molding mold having a plurality of cavities and a flow path branching from a sprue to distribute and supply molten rubber or resin material to each cavity, the portion of the flow path near the inlet to the cavity is divided into two parts. A hole with a bottom that opens into the flow path is provided in one of the molds in the vicinity of the inflow port, and a flow rate adjustment member is fitted into the hole to adjust the height of the protrusion of the member into the flow path. A mold that allows you to adjust the flow rate of material in the flow path.