JPH0644662Y2 - Injection mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a mold for molding an injection molded product such as various synthetic resin link parts applied to, for example, an air conditioner of an automobile. The present invention relates to an injection-molding die of a type in which each molded portion of a sprue, a runner, and a gate and a molded product are separated at the same time when a molded product is ejected from the mold.

(Prior art) A submarine gate with a special structure is adopted as the gate structure, and the sprue part, runner part, and gate part are integrated at the same time when the molded product is ejected following mold opening at the end of injection molding. A part other than the molded product (hereinafter simply referred to as a runner product) should be separated from the desired molded product by itself. For example, an automatic sorting device is installed below the mold opening part and dropped from above. It has been a conventional practice to receive the runner product and the molded product together and automatically select the two.

4 and 5 show an example of the sorting device,
The sorting apparatus 100 includes a rotary drum 102 having a spiral feed blade 101 formed on its peripheral surface and rotating in the direction of an arrow, and a first receiving member which is inclined downward and whose lower end is provided close to the upper surface of the drum 102. It is composed of a plate 103 and a second receiving plate 104 which is inclined downward relative to the first receiving plate and whose lower end is arranged with a predetermined gap 105 with respect to the side surface of the drum 102, and is dropped from above. The link component 26 and the runner product 10 as the coming molded products are received by the first receiving plate 103 and the second receiving plate 104, and the rotary drum
Collected in 102. Normally, the gap 105 is set so that the link component 26 as a molded product can pass through but the runner product 10 cannot pass through.

Therefore, of the link component 26 and the runner product 10 that slide down on the first receiving plate 103 and the second receiving plate 104 and gather on the rotary drum 102 as described above, the former falls downward through the gap 105. The latter is sent out in the axial direction of the drum 102 by the spiral feed blade 101 formed on the rotary drum 102, and both are sorted.

In addition to the automatic sorter described above, for example, Japanese Patent Laid-Open No. 50-101
As disclosed in Japanese Patent No. 448, in a single hopper, the runner molded product and the molded product, which are molded by a multi-shot injection molding machine that simultaneously molds a large number of products on both sides of the runner, are separated into a single hopper. It is introduced and dropped onto a belt conveyor that is driven and rotated actively installed below the hopper outlet, and the runner molded product is supported by a plurality of rows of pins protruding on the surface of the belt conveyor, and at the same time, they are adjacent to each other. There is an automatic sorter that drops and collects a molded product from between pins, and discharges and stores a runner molded product that is supported and moved by the pin into a collection container of the product. The sorting mechanism in this sorting machine is also similar to the above-mentioned conventional machine in that the pin interval is set to a predetermined dimension to separate the molded product from the runner molded product.

(Problems to be solved by the invention) However, in the case of injection molding in which one molded product or two molded products are taken through the submarine gate, the sprue, runner, and gate, which are separated from the molded product at the same time as product ejection, are integrated. The maximum planar thickness of a molded runner product is usually the sprue-runner interface.

If the thickness dimension of this connecting portion is smaller than the passing gap dimension of the molded product formed between the rotary drum and the second receiving plate of the above-mentioned sorting device, the runner product will be formed together with the molded product as shown in FIG. Since it often passes through the same gap, the molded product and the runner product cannot be reliably separated.

On the other hand, also in the automatic sorter disclosed in the above-mentioned publication, among the many runner portions and the many gate portions that project left and right from the runner portion, the distance between adjacent pins is the length obtained by combining the left and right sides of the gate portion. The thickness of the flat surface including the runner part and the gate part is smaller than the distance between the pins, which may be the same depending on the falling posture of the runner molded product from the hopper. The runner product may pass between adjacent pins.

The present invention has been developed in view of these circumstances, and its purpose is to make an injection metal mold for forming a runner product so as to reliably separate a runner product from a molded product separated and mixed on an injection molding machine. To provide the mold.

(Means for Solving the Problems) In order to achieve the above object, the present invention injects a molten resin into a cavity through a sprue formed in the same plane, a runner, and submarine gates at one or both ends of the runner. An injection molding die for obtaining one or two molded products, having a sub-cavity projecting in a cross shape at a predetermined angle from the plane including the sprue and runner, the sub-cavity being orthogonal to the plane. length,
The length of the sprue and the length of the runner are set to be at least longer than the molded product passage gap of a sorting device for separating the molded product from the molded product such as the sprue. .

(Operation) When injection molding is performed using the above mold, the mold is opened and the molded product is ejected by the ejecting device, and at the same time, the molded product and the runner product are separated from each other, for example, a sorting device installed below. Drop on the device.

The runner product is integrally formed with a protruding molded product that projects in a direction intersecting a plane including the sprue and the runner in the sub-cavity portion formed in the mold, and the entire length of the protruding molded product. Is larger than the molded product passing gap of the sorting device.

Therefore, the molded product that slides down on the receiving plate of the sorting device passes through the gap and drops downward, and the runner product that has a protruding molded product that also slides down on the receiving plate does not pass through the gap and rotates. Guided by the spiral feed groove of the drum and discharged in the axial direction, both products are reliably sorted.

(Embodiment) Hereinafter, the present invention will be specifically described with reference to illustrated embodiments. FIG. 1 is a vertical cross-sectional view of a central part of a molding die for a synthetic resin link component used in an air conditioning system for automobiles showing a typical embodiment of the present invention, and FIG. It is a top view.

Although the illustrated embodiment is an injection molding die for automobile parts such as link parts, the present invention is not limited to this embodiment, and it goes without saying that it can be applied to injection molding dies for other products.

Now, explaining the configuration of the mold according to the illustrated embodiment,
Reference numeral 1 is a fixed mold fixed to a fixed plate (not shown), and 2 is a movable mold fixed to the movable plate.

FIG. 1 shows a state in which the fixed mold 1 and the movable mold 2 are closed, 3 is a sprue, 4 is a runner, 5 is a submarine gate usually called a tunnel gate, and 6 is a molding chamber for the link part 26. These are the cavities to be constructed, and these parts are not particularly different from the configuration of the conventional two-piece injection molding die.

Reference numeral 7 denotes a sub-cavity which is the most characteristic part of the present invention. The sub-cavity 7 is provided at a branch portion between the sprue 3 and the runners 4, 4 extending from the tip portion 3-1 of the sprue 3 at right angles to the left and right, It is formed orthogonal to the runners 4, 4.
According to the illustrated example, the shape of the sub-cavity 7 is a cylinder, but the shape is not limited to such a shape, and any shape may be used. It must be longer than the gap size of the product passage gap. Further, the extending direction of the sub-cavity 7 does not necessarily need to be orthogonal to the plane including the sprue 3, runner 4 and gate 5, and the essential point is molding by the sprue 3, runner 4, gate 5 and sub-cavity 7. The protruding direction may be determined so that the molded product (hereinafter referred to as a runner molded product) has a three-dimensional shape that cannot pass through the molded product passage gap of the sorting device.

The sub-cavity 7 can be directly formed on the parting surfaces of the fixed mold 1 and the movable mold 2, and the manufacturing of the mold does not require any particular complexity.

An example of a runner molded product molded by using the injection molding die according to the present invention configured as described above is shown in FIG.

That is, the runner molded product 20 includes a sprue portion 21 formed by the sprue 3 and a runner portion 22 formed by the runner 4.
And a gate portion 23 formed by the submarine gate 5, and a protrusion formed by a sub-cavity 7 protruding from the tip of the sprue portion 21 on both sides of a plane including the portions 21, 22, 23 with a required length. It becomes a three-dimensional molded article having a part 24.

Now, by using an injection molding machine (not shown) using the mold according to the present invention, the runner molded product 20 having the above-described shape and the link component 26 which is the original product are molded, and both are ejected at the same time as the product is ejected after the mold is opened. Are separated and dropped downward.

Below the mold opening, for example, the sorting apparatus 100 shown in FIG. 1 for sorting and separating the link component 26 and the runner molded product 20 is installed.
Drop onto the sorting device 100 in the separated state,
It is received by the receiving plate 103 and the second receiving plate 104, and slides down on both receiving plates 103, 104 toward the rotary drum 102. The link component 26 reaching the rotary drum 102 drops downward as it is through the gap 105 formed between the rotary drum 102 and the second receiving plate 104, and one runner molded product 20 reaches the rotary drum 102. When caught by the spiral feed blade 101, it is fed in the axial direction by the feed blade 101 of the rotating drum 102. At this time, since the runner molded product 20 has a three-dimensional shape having a size equal to or larger than the size of the gap 105, the runner molded product 20 is forcibly sent out in the axial direction by the spirally rotating feed blade 101 without dropping downward from the gap 105. Therefore, the link component 26 is surely selected.

In the above description, the sorting device is installed below the mold opening of the injection molding machine to continuously sort the link component 26 and the runner molded product 20, but the sorting device is separated from the injection molding machine. It may be installed and selected for each predetermined lot.

(Effects of the Invention) As described in detail above, according to the injection molding die of the present invention, the one-piece or two-piece separation is performed in which the molded product and the runner molded product are separated on the injection molding machine. In an injection molding die, a protruding portion having a size larger than a molding product selection gap of a selection device that intersects with a plane including a sprue, a runner, and a submarine gate, and separates and mixes the above-mentioned molded product and runner molded product Since the sub-cavity for molding is formed directly on the parting surface of the fixed mold and the movable mold, the runner molded product molded at the same time does not complicate the manufacture of the mold, and the dimension of the runner molded product is at least the above-mentioned gap or more. With the three-dimensional shape, the product does not pass through the gap of the selecting device, and the product can be reliably selected.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a central portion of an injection molding die showing a typical embodiment of the present invention, FIG. 2 is a top view of the same movable die, and FIG. 3 is formed by the die of the present invention. FIG. 4 is a perspective view showing an example of the runner molded product, FIG. 4 is a perspective view of a main part of the sorting apparatus, and FIG. 5 is a sectional view taken along the line II-II in FIG. Description of the main parts of the figure 1 ... Movable mold, 2 ... Fixed mold 3 ... Sprue, 4 ... Runner 5 ... Submarine gate, 6 ... Cavity 7 ... Sub-cavity 20 ... Runner molded product 21 ...... Sprue part, 22 …… Runner part 23 …… Gate part, 24 …… Projection part 26 …… Link part 100 …… Sorting device 101 …… (spiral) feed blade 102 …… Rotary drum 103,104 …… Receiver Board

Claims (1)

[Scope of utility model registration request] 1. Injection molding for injecting a molten resin into a cavity through a sprue, a runner formed in the same plane, and a submarine gate at one or both ends of the runner to obtain one or two molded products. In the mold, there is a sub-cavity projecting in a cross shape from the plane including the sprue and runner at a predetermined angle, a length orthogonal to the plane of the sub-cavity, a length of the sprue and a length of the runner. Is set to have a dimension at least longer than a molded product passing gap of a sorting device for separating the molded product from the molded product such as the sprue.