JPH056099Y2 - - Google Patents

Description

[Detailed explanation of the invention] "Industrial application field" This invention is based on the main path of the resin in the mold and the runner which is the branch path when injecting resin into a mold to create a molded product. The present invention relates to a runner cut button that can be easily cut after resin hardens.

``Prior art'' When resin is injected into a mold to create a molded product, a number of cavities for the molded products are provided in the mold, and the resin is melted into each cavity from a main passage through multiple runners. We are trying to supply resin. After the resin has hardened in the mold, the runner part or the molded part in the cavity is pushed with an extrusion pin to cut the molded part and the runner, and to separate the molded part from the runner part and the main passage part. I'm trying to take it out of the mold. Note that the connection between the molded product cavity and the runner is formed by a small-diameter gate, so that the two can be easily cut off after the resin has hardened.

``Problem to be solved by the invention'' Conventionally, when injection molding a resin molded product in a mold, the product part and the runner part can be easily separated, but the gap between the runner and the main passage is No measures were taken to facilitate cutting.
This means that in order to facilitate cutting, the cutting point within the mold must be formed into a small diameter gate.
Forming the processing in the mold for this purpose is omitted because it increases the number of processing steps.

However, when creating a large number of product cavities in one mold, the runner part or main passage becomes long, and the runner part or main passage in the connected state taken out from the mold after the resin hardens becomes large. This sometimes caused inconveniences in storage and pulverization.

Therefore, the present invention makes it possible to easily create a mold having branch passages from a main passage to multiple runners.
Moreover, it is an object of the present invention to enable easy cutting between the main passage and the runner.

"Means for Solving the Problems" The present invention is a runner bush provided at a position where a main resin passage in a molding die branches into a plurality of runners. This bush has a cylindrical shape, and one end of the center hole communicates with the main passage of the resin, and the other end allows insertion of an extrusion pin. The bush is also provided with a plurality of slanted holes that communicate the center hole with each runner, and the slanted holes are slanted so that the center hole side faces the ejector pin insertion side. The inclined hole is formed into a tapered hole with a smaller diameter on the center hole side.

"Operation" If the runner cut bush of the above means is placed at the connection between the main passage of the mold and the plurality of runners branching from it, the mold for that part is completed, and the bush is removed from the mold. Alternatively, it can also be incorporated into a separate mold. In addition, the plurality of inclined holes provided in the bushing are inclined toward the push-out pin insertion side, so when the push-out pin is inserted into the center hole of the bush, the runner part of the cured resin is aligned with the center hole of the bush. Cracks easily occur and are cut at the connecting portions, and the cured resin runner portion and the main passage portion are separated.

"Embodiment" An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

By overlapping the upper mold 1 and the lower mold 2, a large number of cavities 3 for molded products are formed, and each cavity 3 is communicated with a runner 4 via a small diameter gate 3a. The other end of the runner 4 is connected to the hole 2a of the lower mold 2.
It communicates with a runner cutout 5 built into the runner. In this embodiment, the runner cutout 5
are in communication with runners 4 in four directions, and each runner 4 is in communication with a separate molding cavity 3.

A main passage member 6 is provided above the runner cut bush 5, and molten resin is supplied from the main passage 6a to each cavity 3 via the runner cut bush 5 and each runner 4. It's summery.

In addition, an extrusion pin 7 is slidably inserted from below into a suitable position of the lower mold 2, such as the cavity 3 or runner 4, and after the resin has hardened in the mold, the molded product or runner part is removed from the mold. It is designed to be extruded.

The runner cutout 5 has a cylindrical shape, and is provided with, for example, four inclined holes 5b that communicate between the center hole 5a and each runner 4 at the outer circumferential position, and the main passage 6a and the runners 4 are 5a and the inclined hole 5b. An extrusion pin 7a is inserted from the lower side of the center hole 5a, and after the resin has hardened, the hardened portion inside the center hole 5a can be extruded. The inclined hole 5b is the center hole 5a.
When the side of the push-out pin 7a is inclined toward the insertion side of the push-out pin 7a and the push-out pin 7a is pushed above the center hole 5a, a crack occurs between the cured resin in the inclined hole 5b portion and the cured resin in the center hole. As a result, the two are disconnected. Further, the inclined hole 5b is formed into a tapered hole having a smaller diameter on the center side than on the outside, so that cracks can easily occur in the cured resin inside the inclined hole. Further, a flange 5c is formed on the outer periphery of the push-out pin insertion side of the runner cutout 5 to facilitate positioning of the runner cutout 5 within the mold.

Note that the mold can be used not only to create molded products of thermoplastic resin, but also to create molded products of thermosetting resin.

``Effect of the invention'' The runner cutout of the invention enables communication between the main resin passage and multiple runners by simply incorporating them into the joint position within the mold.
The mold is easy to manufacture because it is only necessary to form a simple hole in the mold to incorporate the runner cutout. Moreover, since it can be incorporated into molds for different molded products, the value of the runner cutout is extremely high. In addition, when the extrusion pin is pushed into the center hole of the runner cutout after the resin has hardened, the runner part and the main passage part can be easily cut off, making it convenient for storing and crushing the runner part extruded from the mold. Good.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of a mold incorporating a runner cutout according to the present invention, and FIG. 2 is a top view of the runner cutout. 1... Upper mold, 2... Lower mold, 3... Cavity, 4
...Runner, 5...Runner cuts,
5a...center hole, 5b...slanted hole, 5c...tsuba,
6a...main passage, 7...extrusion pin.

Claims (1)

[Claims for Utility Model Registration] (1) A branching bush for branching a resin main passage into a plurality of runners in a molding die, the bushing being formed in a cylindrical shape with a central hole, One end of the center hole can communicate with the main passage, and the other end allows insertion of an extrusion pin, and the bush is provided with a plurality of inclined holes that communicate the center hole with each runner.
The runner cutout is characterized in that the inclined hole is inclined so that the center hole side thereof faces toward the ejector pin insertion side. (2) The runner cutout according to claim 1, wherein the inclined hole is formed as a tapered hole having a small diameter on the center hole side.