JP2008037052A - Injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection molding machine for molding a product by providing an injection unit for plasticizing a resin at a fixed side and a movable side of the injection molding machine and by injecting the resin plasticized by improving the timing for injecting a plasticized resin into a cavity of a mold of these injection units. <P>SOLUTION: In the injection molding machine provided with the injection unit 3 for plasticizing the resin arranged at the fixed side 1a of the injection molding machine and for molding a product by injecting the plasticized resin into a cavity of the mold, an injection unit 13 opposing to the injection unit 3 described above is arranged and also at the movable side 1b of the injection molding machine, by controlling a timing for injecting the resin material into a cavity 7a of the mold from the injection unit 3 arranged at the fixed side 1a of the injection molding machine described above and a timing for injecting the resin material into a cavity 7a of the mold from the injection unit 13 arranged at the movable side 1b of the injection molding machine described above are controlled by an electric circuit 14 and the resin is injected from the both sides to one cavity 7a of the mold to fabricate the product. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an injection molding machine for injection molding of components used in electrophotographic copying machines, printers, and the like.

Conventionally, an injection molding machine is configured by arranging an injection unit mechanism for plasticizing resin on the injection molding machine fixed side and a mold clamping mechanism on the movable side, and a metal mold between the injection molding machine fixed side and the movable side. It is common to install a mold.
FIG. 2 is a schematic sectional view showing a configuration of a conventional injection molding machine. 2 is divided into an injection molding machine fixed side 1a and an injection molding machine movable side 1b. The injection molding machine fixed side 1a and the injection molding machine movable side 1b are connected to each other by a tie bar 5. .
The resin material put in from the resin material supply hopper 2 on the injection molding machine fixing side 1a is plasticized by the injection unit 3 to bring the resin material into a molten state. The resin material corresponding to the mold cavity is weighed by the injection unit 3.
The molds 6 and 7 on the fixed side 1a and the movable side 1b are clamped by the mold clamping mechanism 4, and the resin weighed from the injection unit 3 is injected into the mold cavity 7a via the hot runner mechanism 8 to obtain the product 9 (FIG. 2, a gear) is formed.
While the molten resin material is cooled and solidified, the injection unit 3 measures the amount of resin material corresponding to the mold cavity. After completion of cooling and weighing, the mold clamping mechanism 4 releases the mold clamping and takes out the molded product.

With such an injection molding machine, mold clamping, injection, product cooling and resin material measurement, mold opening, and product removal are repeated, and a desired injection molded product is continuously injection molded.
Usually, when the plasticizing allowance of the injection unit device that plasticizes the material resin does not reach the weight of the product to be molded, the part that stores the plasticized resin of the injection unit device to increase the plasticizing allowance Generally, the volume of is increased.
However, in some cases, it is necessary to increase the injection pressure for injecting the plasticized resin having an increased volume into the mold cavity, and there is a case where it is necessary to increase the capacity of the injection pressure source (for example, a servo motor). . At this time, the injection unit device itself may become large.
However, in order to increase the plasticization allowance, if the volume of the plastic unit of the injection unit device is increased, the metering time for weighing the resin material corresponding to the mold cavity and the mold cavity will be increased. Since the injection time for injecting the resin material is extended, the cycle time becomes long.
For this reason, conventionally, an injection molding machine has been proposed in which a material injection gate is provided in both the fixed mold and the movable mold facing the fixed mold to improve the above-described disadvantage (for example, Patent Document 1). reference).

Japanese Patent Laid-Open No. 10-015992

However, when the material injection gate is provided in both the fixed mold and the movable mold opposite to the fixed mold as in Patent Document 1, the resin material is transferred from the material injection gate provided on the fixed side to the mold cavity. The timing of injection and the timing of injecting the resin material from the material injection gate provided on the movable mold side into the mold cavity are important.
Accordingly, an object of the present invention is to provide an injection unit that plasticizes resin on the fixed side and the movable side of the injection molding machine in consideration of the above-described situation, and plasticize resin in the mold cavity of these injection units. It is an object of the present invention to provide an injection molding machine that molds a product by injecting it with good timing.

In order to solve the above problems, the invention according to claim 1 is provided with an injection unit for plasticizing a resin on the fixed side of the injection molding machine, and injecting the plasticized resin into a mold cavity to produce a product. In the injection molding machine to be molded, an injection unit is provided on the movable side of the injection molding machine so as to face the injection unit, and a timing for injecting a resin material from the injection unit provided on the fixed side of the injection molding machine into a mold cavity; The timing of injecting the resin material from the injection unit provided on the movable side of the injection molding machine to the mold cavity is controlled by an electric circuit, and the product is molded by injecting resin from both sides to one mold cavity It features an injection molding machine.
The invention according to claim 2 is characterized by the injection molding machine according to claim 1, wherein the resin material in the runner portion from the injection unit to the gate leading to the cavity is heated and kept in a molten state.
According to a third aspect of the present invention, the electric circuit includes a temperature control circuit that heats and retains the resin material in the runner portion in a molten state, and the temperature control circuit includes the injection molding machine fixing side and the temperature control circuit. The injection molding machine according to claim 1, wherein each temperature is controlled on the movable side.
According to a fourth aspect of the present invention, there is provided the injection molding machine according to any one of the first to third aspects, wherein the component on the fixed side of the injection molding machine and the component on the movable side of the injection molding machine are shared. Features.

According to the present invention, an injection unit facing the injection unit on the fixed side of the injection molding machine is also provided on the movable side of the injection molding machine, and the mold cavity is formed by injecting resin from both sides to one cavity of the mold. It is possible to mold without extending the measuring time for measuring the resin material corresponding to the above and the injection time for injecting the resin material into the cavity of the mold.
In addition, the same material can be molded with two types of resin materials or with the same resin material of different colors, and the timing of injecting the resin material into the mold cavity from the injection unit provided on the fixed side of the injection molding machine The amount of resin material (filling balance) to be filled into the mold cavity can be arbitrarily adjusted by changing the timing of injecting the resin material from the injection unit provided on the movable side of the injection molding machine into the mold cavity. Is possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic sectional view showing an injection molding machine according to the present invention together with a control circuit block. The injection molding machine 1 in FIG. 2 is divided into an injection molding machine fixed side 1a and an injection molding machine movable side 1b, and these are connected by a tie bar 5 as in the conventional case.
The resin material put in from the resin material supply hopper 2 on the injection molding machine fixing side 1a is plasticized by the injection unit 3 to bring the resin material into a molten state. The resin material corresponding to the mold cavity is weighed by the injection unit 3.
Another injection unit 13 is arranged on the injection molding machine movable side 1b, and the injection unit 3 provided on the injection molding machine fixed side and the other injection unit 13 provided on the injection molding machine movable side 1b are connected by a control circuit 14. Has been.
A hot runner mechanism 8 for heating and keeping the resin material in the runner portion from the injection unit 13 to the gate leading to the cavity 7a in a molten state is also provided in opposition. If it does in this way, runnerless shaping | molding will become possible and it will become possible to shape | mold, without taking out a waste material.
Thus, by providing the injection units 3 and 13 on the injection molding machine fixed side 1a and the injection molding machine movable side 1b, molding can be performed with the same material using two types of resin materials or with the same resin material of different colors. It becomes.
Further, by making the components used on the injection molding machine fixed side 1a and the components used on the injection molding machine movable side 1b common, the manufacturing cost can be reduced and the maintainability can be improved.

An injection timing adjusting circuit 15 that adjusts the timing of injecting the resin material of the control circuit (electric circuit) 14 injects the resin material into the cavities 7a of the molds 6 and 7 from the injection unit 3 provided on the fixed side of the injection molding machine. The timing and the timing of injecting the resin material from the injection unit 13 provided on the movable side of the injection molding machine to the cavities 7a of the molds 6 and 7 are changed as necessary. The amount (filling balance) of the resin material filled in the cavity 7a can be arbitrarily adjusted.
In order to heat and keep the resin material in the runner in a molten state, the control circuit 14 includes a temperature control circuit 16 for controlling the temperature, and the temperature control circuit 16 is used for the injection molding machine fixed side and the movable side, respectively. Control the temperature.
This makes it possible to arbitrarily adjust the filling amount (filling balance) into the mold cavity by the flow rate difference at the time of injection due to the melting temperature difference. Further, it is possible to mold with two kinds of materials having different melting temperatures.
The molds 6 and 7 on the fixed side 1 a and the movable side 1 b are clamped by the mold clamping mechanism 4, and the resin weighed from the injection units 3 and 13 is injected into the cavities of the molds 6 and 7 through the hot runner mechanism 8. Product 9 is molded.
While the molten resin material is cooled and solidified, the injection units 3 and 13 measure the amount of resin material corresponding to the mold cavity (in this case, 7a).
After the resin material is cooled and weighed, the mold clamping mechanism 4 releases the mold clamping and takes out the molded product. Continuous molding is performed by repeating mold clamping, injection, product cooling and resin material measurement, mold opening and product removal.

It is a schematic sectional drawing which shows the injection molding machine by this invention with a control circuit block. It is a schematic sectional drawing which shows the structure of the conventional injection molding machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection molding machine 1a Injection molding machine fixed side 1b Injection molding machine movable side 2 Resin material supply hopper 3 Injection unit (injection molding machine fixed side)
4 Clamping mechanism 6 Mold (on the fixed side)
7 Mold (on the movable side)
7a Cavity 8 Runner (hot runner mechanism)
9 Molded products
13 Injection unit (on the movable side of the injection molding machine)
14 Electric circuit (control circuit)
15 Injection timing adjustment circuit 16 Temperature control circuit

Claims (4)

  In the injection molding machine that molds the product by injecting the plasticized resin into the mold cavity by providing an injection unit that plasticizes the resin on the fixed side of the injection molding machine, the injection molding machine is movable facing the injection unit An injection unit is also provided on the side, the timing at which the resin material is injected from the injection unit provided on the fixed side of the injection molding machine into the mold cavity, and from the injection unit provided on the movable side of the injection molding machine to the mold cavity. An injection molding machine characterized in that the timing of injecting a resin material is controlled by an electric circuit and a product is molded by injecting resin from both sides into one cavity of a mold.   The injection molding machine according to claim 1, wherein the resin material in the runner portion from the injection unit to the gate leading to the cavity is heated and kept in a molten state.   The electric circuit includes a temperature control circuit that heats and keeps the resin material in the runner portion in a molten state, and the temperature control circuit controls the temperature on each of the injection molding machine fixed side and the movable side. The injection molding machine according to claim 1.   The injection molding machine according to any one of claims 1 to 3, wherein the component on the fixed side of the injection molding machine and the component on the movable side of the injection molding machine are shared.

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