JPH08258091A - Runner automatic cutting type opening mechanism, runner cutting method, mold and injection molding method - Google Patents

Abstract

PURPOSE: To enable full-automatic molding without raising the production cost of a mold by operating a gate cutting core cooperated with mold opening in slide contact with a gate part to cut off the connection of a product and a runner. CONSTITUTION: When a mold is opened at the time of the taking-out of a product by mold opening, the product 1 and a molding part 4 by a sprue bush 2 are separated from a fixed template 11 by the spring 7 built in the mold to be left on a movable template 12 but, at this time, a gate cutting core 12 is operated in slide contact with a gate part by a core spring 15 to cut off the connection of the product 1 and the molding part 4 by the sprue bush. After mold opening, a movable push-out plate 8 is moved and movable push-out pins 9, 10 are cooperated to push out the product 1 and the molding part 4 by the sprue bush 2 from the movable template 12 to release them but, at this time, the product 1 and the molding part 4 by the sprue bush 2 are cut off, only the product 1 is taken out to be automatically packed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold opening mechanism in injection molding in which a molding material is introduced into a cavity from a side gate connected to a spool bush and its application technique.

[0002]

2. Description of the Related Art A conventional injection molding method will be described with reference to FIGS. FIG. 6 shows a so-called two-plate mold A (cross section) of a type in which a product and a gate are taken out from the same mold division surface. The molding material has already been introduced into the mold A by a nozzle (not shown) connected to the spool bush 2, and the molding portion 4 is formed by the product 1 and the spool bush 2.
In the figure, reference numeral 3 is a gate, 5 is a fixed extrusion plate, 6 is a fixed extrusion pin, 7 is a spring, 8 is a movable extrusion plate, and 9 is a movable extrusion plate.
Reference numerals 10 and 10 denote movable push-out pins, 11 denotes a fixed-side template, and 12 denotes a movable-side template. Here, the gate 3 is composed of a fixed-side mold plate 11 and a movable-side mold plate 12 surface.

When the mold A is opened after the injected molding material has been cooled and solidified or hardened, the molding part formed by the product 1 and the spool bush 2 is fixed on the fixed side mold plate by the spring 7 built in the mold A. It is released from the mold 11 and remains on the movable side mold plate 12 as shown in FIG. Then, by moving the movable push-out plate, the movable push-out pins 9 and 10 are interlocked with each other to push the product 1 and the molding portion 4 formed of the spool bush from the movable-side mold plate 12 to release the mold (FIG. 8A).
reference).

[0004]

In the above method, the obtained product 1 is connected to the molding portion 4 by the spool bush at the gate portion as shown in FIG. 8 (b). It is necessary to cut by processing, which requires facilities and labor for that, and finally has a drawback that the product cost rises.

On the other hand, a method using a submarine gate (tunnel gate) is known as a method for improving this drawback and automatically disconnecting the connection between the product and the molded portion by the spool bush when the product is taken out. The method requires a narrow gate in order to prevent the product from being released from the mold or from becoming unusable as a product due to a defective cut point. It takes time to form, and defective products such as sink marks and bubbles are likely to occur in the product, or it is difficult to apply it to molding with a molding material containing a filler or a reinforcing material, and a depth of diving is required to some extent.
There are drawbacks such as limited product shapes that can be applied. Therefore, there has been a demand for a runner cutting mechanism that can be molded under the same molding conditions as when a normal side gate mold is used and that has a small effect on cost.

[0006]

In order to solve such a conventional drawback, the runner automatic cutting die opening mechanism of the present invention provides a molding material from the side gate connected to the spool bush into the cavity as described in claim 1. In the mold opening mechanism of injection molding, after introducing and cooling and solidifying or hardening, the product is opened and the product is taken out. It employs a configuration that disconnects the connection. Further, the present invention is a method for cutting the runner at the time of opening the mold by using such a runner automatic cutting mold opening mechanism. Further, a molding die having such a runner automatic cutting die opening mechanism and the mold thereof are used. It is a molding method.

[0007]

When the injection molding mechanism according to the present invention is used, the connection between the product and the molding portion by the spool bush is automatically cut off, so that fully automatic molding is possible. Further, since the gate having the same size as that of normal injection molding can be used, the pressure loss at the time of injection is small, and the injection molding can be performed under the same conditions as usual. Further, it has not been said that molding defects such as sink marks are likely to occur in the product, and it can be used for molding with a molding material containing a filler such as a reinforcing material.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A runner automatic cutting type opening mechanism of the present invention will be described with reference to FIGS. FIG. 1 shows a mold having a runner automatic cutting mold opening mechanism according to the present invention. This mold is a so-called two-plate mold in which the product and the gate are taken out from the same mold division surface.

In the figure, reference numeral 2 is a spool bush, 3 is a gate, 5 is a fixed extrusion plate, 6 is a fixed extrusion pin, 7 is a spring, 8 is a movable extrusion plate, 9 and 10 are movable extrusion pins, and 11 is a fixed side mold. A plate, 12 is a movable side mold plate, 13 is a product forming portion (cavity), 14 is a gate cutting core, and 15 is a core spring. The gate 3 is formed from the fixed-side template 11 and the surface of the gate cutting core 14. The shape of the gate 3 is preferably a normal side gate shape, and does not need to be a special shape such as a submarine gate or a pinpoint gate.

Molding using this mold is performed as shown in FIG. That is, a nozzle (not shown) is connected to the spool bush 2 of this mold, the molding material is introduced from the gate 3 into the cavity 13 through the spool bush 2 as a path, and is cooled and solidified or cured to form the product 1. To do.

Next, the product is taken out by opening the mold. First, as shown in FIG. 3, when the mold is opened, the molding portion 4 formed by the product 1 and the spool bush 2 becomes
The mold 7 is released from the stationary mold plate 11 by the spring 7 built in the mold and remains on the movable mold plate 12 as shown in FIG. Slide to disconnect the connection between the product and the molding portion 4 by the spool bush. Here, as shown by L in FIG. 5, the sliding portion of the gate cutting core 14 is processed into a blade shape (acute angle) so that the gate portion can be easily cut. Further, the edge portion of the gate cutting core 14 is processed by titanium coating so as to have abrasion resistance.

After the mold is opened, as shown in FIG. 4, the movable push-out plate 8 is moved, whereby the movable push-out pins 9 and 10 are interlocked with each other so that the molded portion 4 formed by the product 1 and the spool bush 2 is moved from the movable side mold plate 12. It is extruded and released, but at this time, the product 1 and the molding portion 4 formed by the spool bush are
Since it is cut as described above, it is possible to perform automation such as, for example, taking out the molding unit 4 by a selection take-out machine or the like due to a difference in shape and the like and packing only the product 1.

[0013]

When the runner automatic cutting die opening mechanism according to the present invention is used, the connection between the product and the molding portion by the spool bush is automatically cut in cooperation with the die opening although it is a very simple mechanism. As a result, fully automatic molding is possible without increasing the production cost of the mold. Therefore, it is possible to save another facility and labor for cutting and reduce the production cost of the product. Further, by selecting the product and the spool bush according to the difference in the shape of the molding portion, it becomes easy to fully automate the product packaging, for example.

Also, since the gate of the mold according to the present invention can be of the same size as that of normal injection molding, the pressure loss during injection is small, and injection molding can be performed under the same conditions as usual. Since it is possible, the productivity is not reduced by changing the injection conditions. In addition, molding defects such as sink marks are unlikely to occur in the obtained product, and it can be applied to molding with a molding material containing a filler such as a reinforcing material.

[Brief description of drawings]

FIG. 1 is a mold having a runner automatic cutting mold opening mechanism according to the present invention.

FIG. 2 is an explanatory view (after introducing a molding material) of a molding method using a mold having a runner automatic cutting mold opening mechanism according to the present invention.

FIG. 3 is an explanatory view (mold opening step) of a molding method using a mold having a runner automatic cutting mold opening mechanism according to the present invention.

FIG. 4 is an explanatory view of a molding method using a die having a runner automatic cutting die opening mechanism according to the present invention (product taking-out step).

FIG. 5 is a gate cut core and a partially enlarged view thereof.

FIG. 6 is an explanatory view of a conventional molding method using a mold (after the molding material is introduced).

FIG. 7 is an explanatory view of a conventional molding method using a mold (mold opening step)
Is.

FIG. 8A is an explanatory view of a molding method using a conventional die (product taking-out step). (B) A product obtained by a conventional molding method.

[Explanation of symbols]

 1 Product 2 Spool Bushing 3 Gate 4 Molding Part (by Spool Bushing) 5 Fixed Extrusion Plate 6 Fixed Extrusion Pin 7 Spring 8 Movable Extrusion Plate 9 Movable Extrusion Pin 10 Movable Extrusion Pin 11 Fixed Side Mold Plate 12 Movable Side Mold Plate 13 Cavity 14 Gate cutting core 14a Gate cutting part 15 Core spring

Claims (5)

[Claims] 1. A mold opening mechanism for injection molding, in which a molding material is introduced into a cavity from a side gate connected to a spool bush and is cooled and solidified or hardened, and then a product is opened to take out a product. A gate cutting core that interlocks with opening, slides the gate and cuts the connection between the product and the runner. 2. In an injection molding method in which a molding material is introduced into a cavity from a side gate connected to a spool bush and is cooled and solidified or hardened, and then a product is opened to take out a product, it is interlocked with the mold opening at the time of mold opening. A method for cutting a runner, characterized in that the gate cutting core slides on the gate portion to cut the connection between the product and the runner. 3. An injection molding die for taking out a product by introducing a molding material into a cavity from a side gate connected to a spool bush, cooling and solidifying or hardening, and then taking out a product. A molding die characterized in that a gate cutting core that is interlocked with is provided with a mechanism for sliding the gate portion to cut the connection between the product and the runner. 4. The molding die according to claim 3, wherein the gate cutting portion of the gate cutting core has an acute angle. 5. In an injection molding method in which a molding material is introduced into a cavity from a side gate connected to a spool bush and is cooled and solidified or hardened, and then a product is opened to take out a product, it is interlocked with the mold opening at the time of mold opening. An injection molding method, characterized in that a molding die having a mechanism in which the gate cutting core slides on the gate portion to cut the connection between the product and the runner is used.