JPH0576719U - Injection mold - Google Patents

Abstract

(57) [Summary] [Structure] The knockout pin 2 is stored in the cylinder 1.
A sprue / runner / knockout mechanism is incorporated in the mold 4 to cause the pin 2 to be elastically projected and housed under pressure in association with opening / closing of the molds 4 and 5. [Effect] A dedicated take-out machine is unnecessary, the cost of the apparatus is reduced, and the size is reduced. The sprue runner 7 will drop due to its own weight, enabling automatic molding.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to an injection mold. More specifically, the present invention relates to an injection mold capable of automatic molding such as a three plate structure.

[0002]

[Prior art]

 Injection molding machines have been widely used for plastic processing of various molded products, and the mold for injection molding plays an extremely important role in determining the efficiency of injection molding and the quality of molded products. It's done. It is known that the pinpoint gate method is effective for improving the efficiency of such injection molding and the quality of the molded product, and an injection molding die having a three-plate structure is used for the pinpoint gate method. Often.

FIG. 3 shows a typical example of the injection molding die having the three-plate structure. The mold has a mold structure (a) (a) (c) divided into three parts.

[0004]

[Problems to be solved by the device]

 This three-plate structure injection molding die greatly contributes to the improvement of injection molding accuracy and productivity by the pinpoint gate method. However, in this conventional injection molding die, as is clear from FIG. 3 showing the mold open state, after injection molding, the sprue runner (d) to which the resin with high viscosity adheres remains and remains as it is. Then, the next molding is not possible.

Therefore, in the past, in order to remove the fixed sprue runner (d), a dedicated take-out machine was required. For example, a general-purpose rotary type and traverse type unloader had a structure in which only molded products were chucked, so a dedicated unloader was inevitable. However, the use of such a special-purpose machine was troublesome to operate and required additional equipment, which was an obstacle to the reduction of productivity and production cost.

The present invention has been made in view of the above circumstances, and eliminates the drawbacks of the molding operation using the conventional injection molding die having a three-plate structure, and provides a sprue / runner exclusive take-out machine. It is an object of the present invention to provide a new injection molding die that can perform automatic molding with high accuracy without the need.

[0007]

[Means for Solving the Problems]

 As a solution to the above-mentioned problems, the present invention provides a sprue-runner-knockout mechanism in which a knockout pin is housed in a cylinder, and this pin is interlocked with the opening and closing of a mold to elastically project and push. (EN) Provided is an injection molding die, which is characterized by being built in the die.

That is, in the present invention, the knockout (KO) pin is housed in the cylinder, and the knockout pin is projected at the same time as the mold is opened by the elastic expansion and contraction means such as a spring and is returned to the inside of the cylinder at the same time as the mold is closed. To do. Then, the sprue and runner fixed to the mold are knocked out and removed by the protrusion of the pin when the mold is opened.

[0009]

[Action]

 In the present invention, the knockout pin that projects at the same time as the mold opening knocks out and removes the sprue / runner by arranging the knockout pin that can be elastically projected and stored in the cylinder as described above. It is possible to drop the sprue and runner under its own weight without the need for a special unloader as shown in.

Therefore, automatic molding is possible. Examples will be shown below to describe the injection mold of the present invention in more detail.

[0011]

【Example】

 FIG. 1 is a partial sectional view showing an example of an injection molding die of the present invention. For example, as shown in FIG. 1, the mold of the present invention is an injection mold having a three-plate structure, in which a knockout pin (2) is housed in a cylinder (1) and the knockout pin (2 ) Through an elastic means such as a spring (3), and when the molds (4) and (5) are opened, this pin is projected by the elastic force of the spring (3) and the molds (4) and (5). When is closed, the spring (3) and the like are pressed and compressed so that the knockout pin (2) is housed in the cylinder (1).

That is, when the molds (4) and (5) are closed, the end (6) of the knockout pin (2) is pressed by the mold (5) as shown in FIG. It is pushed into the cylinder (1). At this time, the spring (3) and the like are in a compressed state. Then, after the injection molding is performed, when the molds (4) and (5) are opened, the pressing force of the end portion (6) of the knockout pin (2) is released, and the end portion (6) is replaced by the spring (3). ) And the like are projected by the elastic force. At this time, the sprue runner (7) fixed by injection molding is knocked out by this protrusion, separated from the fixed state and dropped by its own weight.

FIG. 2 exemplifies a state in which the knockout pin (2) is projected at the time of opening and the sprue runner (7) is dropped by its own weight. The knockout pin (2) may be springy and compressed by a spring (3) or other suitable means. Moreover, it is preferable that the knockout pin (2) is provided with an appropriate stopper mechanism so as not to completely project from the cylinder (1) when it projects.

Further, a plurality of such sprue / runner / knockout mechanisms may be provided as shown in FIG. Of course, the size and shape of the mold of this invention are not particularly limited.

[0015]

[Effect of the device]

 As described in detail above, according to the present invention, the sprue and runner can be easily knocked out automatically, a special take-out machine is unnecessary, the cost of the apparatus is reduced, and the apparatus is downsized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a mold of the present invention.

FIG. 2 is a cross-sectional view exemplifying a protruding state of a knockout pin of the mold of the present invention.

FIG. 3 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 Cylinder 2 Knockout pin 3 Spring 4, 5 Mold 6 Knockout pin end 7 Sprue runner

Claims (1)

[Scope of utility model registration request] 1. A knockout pin is housed in a cylinder,
An injection molding die characterized in that a sprue / runner / knockout mechanism for elastically projecting and pressing and storing this pin in conjunction with opening / closing of the die is built into the die.