JP3340823B2 - Injection molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for supplying a resin material and a liquid colorant such as a liquid color into a heating cylinder, and weighing the resin material while kneading the colorant inside the heating cylinder. The present invention relates to an injection molding apparatus for molding a molded article of a desired color by filling the molded article with a desired color.

[0002]

2. Description of the Related Art In an injection molding apparatus of this kind, generally, a hopper for storing a resin material and supplying the resin material to the inside, a container for storing the colorant, and a colorant supply pipe for storing the colorant in the container. A pump or the like that supplies the inside of the heating cylinder through the pump and a screw that is located inside the heating cylinder along the axial direction are provided. At the time of molding, the resin material is supplied from the inside of the hopper to the inside of the heating cylinder, and the colorant in the container is supplied to the inside of the heating cylinder through a colorant supply pipe by a pump or the like. It is heated and melted by a heater, and the resin material is measured while being kneaded with a colorant by rotation of the screw.

By the way, if the outlet of the colorant supply pipe is set at a position far away from the outer periphery of the screw, the colorant scatters during the supply of the colorant and adheres to the inner wall of the heating cylinder. When a different colorant is supplied to the inside of the heating cylinder to change the color of a molded article, the colorant before the color change is mixed and the color changeability is deteriorated. The colorant is set at a position close to the outer periphery to prevent scattering of the colorant.

[0004]

However, in the above-mentioned conventional structure, when the resin material is measured, the rotation of the screw causes the resin material to be pushed to the outer periphery of the screw and to be clogged in the colorant supply pipe. Has a problem that the supply amount of the colorant is not stable, and a molded product having a stable color cannot be formed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an injection molding apparatus capable of eliminating a resin clogging in a colorant supply tube and stabilizing a supply amount of a colorant.

[0006]

According to the present invention, a resin material and a liquid colorant are supplied into a heating cylinder, the resin material is kneaded with the colorant inside the heating cylinder, and the resin material is measured and filled into a mold. A container for storing a colorant, a colorant supply means for supplying the colorant in the container through the colorant supply pipe to the inside of the heating cylinder, and a colorant supply pipe directed toward the outlet side. And an air sending means for sending air through the air sending pipe to the colorant supply pipe at the time of measuring the resin material.

[0007]

According to the present invention, when the resin material is measured, air is sent from the blowing means to the outlet side of the colorant supply pipe through the air delivery pipe, so that the resin material does not clog the colorant supply pipe. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an injection molding apparatus to which the present invention is applied will be described with reference to the drawings. In this injection molding apparatus, as shown in FIG. 1, a mold 1, a heating cylinder 2, a hopper 4 for storing a resin material 3 such as polyacetal, and a container for storing a liquid colorant 5 such as a liquid color. The resin material 3 in the hopper 4 and the colorant 5 in the tank 60 are supplied into the heating cylinder 2 while the resin material 3 is kneaded with the colorant 5 in the heating cylinder 2. The mold 1 is weighed and filled into the mold 1.

The mold 1 includes a fixed mold 7 attached to a fixed die plate 6 and a movable mold 9 attached to a movable die plate 8 so as to face the fixed mold 6.
And a tie bar 10 that guides the movable die plate 8 so that the movable mold 9 comes into contact with and separates from the fixed mold 7. The movable die plate 8 has a mold clamping cylinder 11
Are driven along the tie bar 10 by the mold clamping cylinder 11. The mold clamping cylinder 11 is located at a position where the movable mold 9 is in contact with the fixed mold 7 and the fixed mold 7 and the movable mold 9 are clamped, and the movable mold 9 is fixed to the fixed mold 7. The movable die plate 8 can be driven to a position where the fixed mold 7 and the movable mold 9 are separated from each other. When the fixed mold 7 and the movable mold 9 are clamped, a cavity 12 having a predetermined shape is formed between the fixed mold 7 and the movable mold 9. A runner 13 that communicates with the cavity 12 is formed in the fixed mold 7, and a sprue 14 that communicates with the cavity 12 through the runner 13.
Is formed.

A nozzle 15 is formed at the front end of the heating cylinder 2 so as to fit with the sprue 14 of the fixed mold 7, and the rear end of the heating cylinder 2 is fitted with a lower portion of the hopper 4 so that the resin inside the hopper 4 can be removed. A material supply port 16 to which the material 3 is supplied is formed. The heating cylinder 2 is provided with a heater 17 on its outer circumference and a screw 18 provided in the inside along the axial direction. The resin material 3 supplied from the inside of the hopper 4 through the material supply port 16 is heated by the heater 17. The screw is heated and melted, and is transferred to the nozzle 15 side by the rotation of the screw 18 for measurement. Screw 18
Is driven to rotate by the driving force of a driving motor 21 via gears 19 and 20. Also, screw 18
Is connected to the injection cylinder 22 and can be advanced or retracted toward the nozzle 15 by the driving force of the injection cylinder 22, and the resin material 3 is injected from the nozzle 15 into the cavity 12 through the runner 13 by advancing toward the nozzle 15. It has become. The screw 18 has a gradually increasing diameter toward the nozzle 15 side, and also has a function of heating and melting the resin material 3 while shearing it during rotation.

A plurality of tanks 60 are provided, each of which stores a colorant 5 having a different color. A colorant supply pipe 23 is provided between each tank 60 and the heating cylinder 2, and the colorant 5 in each tank 60 is supplied to the inside of the heating cylinder 2 through each colorant supply pipe 23. It has become.

The colorant supply pipe 23 is connected to the lid 24 of the tank 60.
The nozzle 25 is mounted so as to be immersed in the colorant 5 in the tank 60, a flexible tube 26 connected to the nozzle 25, and connected to the nozzle 25 via the flexible tube 26. And a colorant injection nozzle 27 inserted into the material supply port 16 of the heating cylinder 2.

At the intermediate portion of each flexible tube 26, a pump 28 is provided correspondingly, and when the resin material 3 is measured, each pump 28 is selectively driven so that a desired colorant 5 in a tank 60 is provided. To the inside of the heating cylinder 2. As shown in FIG. 2, the pump 28 is provided with a housing 29, and an intermediate portion of the flexible tube 26 is installed from below the housing 29 to below the housing 29 through the inside thereof. A rotor 30 is rotatably mounted inside the housing 29, and an intermediate portion of the flexible tube 26 is wound around the outer periphery of the rotor 30. A plurality of rollers 31 that partially press the flexible tube 26 with the inner wall of the housing 29 are attached to the outer periphery of the rotor 30. It is sent out inside. Each of these pumps 2
Each of the support frames 8 is attached to an independent support frame 32. The support frame 32 is provided with a switch 33 for designating the rotation speed of the rotor 30 and the like. The inside of the heating cylinder 2 is sent out from the inside.

The colorant injection nozzle 27 is vertically inserted into the material supply port 16 of the heating cylinder 2 so that the colorant 5 can smoothly flow into the heating cylinder 2.
The outlet 27 a of the colorant injection nozzle 27 is set at a position close to the outer periphery of the screw 18 so that the colorant 5 does not scatter and adhere to the inner wall of the heating cylinder 2 when the colorant 5 is supplied. The colorant injection nozzle 27 is branched into two at an intermediate portion, and one of the two branches is connected to a flexible tube 26.
The other is an air delivery pipe 34 capable of delivering air toward the outlet 27a. The air delivery pipe 34 has a solenoid valve 35
An air pump 36 as a blowing means is connected through
Air is sent from the air pump 35 when the solenoid valve 35 is opened. Each of the solenoid valves 35 is opened in conjunction with the pump 28 so that each of the air pumps 36 causes the respective colorant injection nozzles 27 to send air toward the outlet 27a thereof from the respective air pump 36 through the air sending unit 34 when the resin material 3 is measured. Has become.

Next, the operation will be described. During molding, the resin material 3 in the hopper 4 is supplied into the heating cylinder 2 through the material supply port 16. Inside the heating cylinder 2,
Screw 1 while resin material 3 is being melted by heater 17.
Due to the rotation of 8, it is transferred to the nozzle 15 side and measured.
At the time of this measurement, each pump 28 is selectively driven to supply the coloring agent 5 in a desired tank 60 into the heating cylinder 2 through the material supply port 16, and the resin 18 is rotated inside the heating cylinder 2 by the rotation of the screw 18. Material 3 is colorant 5
Is weighed while being kneaded.

When the fixed mold 7 and the movable mold 9 are clamped by the mold clamping cylinder 11, the screw 18 advances toward the nozzle 15 by the driving force of the injection cylinder 22 and the resin material is 3 is injected from the nozzle 15 into the cavity 12, and the cavity 12 is filled with the resin material 3. The resin material 3 filled in the cavity 12 is solidified in the cavity 12, whereby a molded product having a desired color is formed.

When the resin material 3 is measured, the pump 2
8, the electromagnetic valve 35 is opened and each air pump 36
Then, air is sent out to the respective colorant injection nozzles 27 through the air delivery pipe 34 toward the outlet 27a side, and the resin material 3 does not clog the respective colorant injection nozzles 27.

Accordingly, each colorant supply pipe 23 does not become clogged with resin, the supply amount of the colorant is stabilized, and a molded product having a stable color can be formed.

In the above embodiment, each air delivery pipe 34
Although the air pump 36 is connected to the air pump 36 via the electromagnetic valve 35, the electromagnetic valve 35 may be omitted, and the air pump 36 may be directly connected to each air delivery pipe 34. May be connected to an air delivery pipe, and an air pump 36 may be connected to this air delivery pipe so that air is delivered to each air delivery pipe 34 by a single air pump 36.

[0020]

As described above, the injection molding apparatus according to the present invention is provided with the blowing means for sending air toward the outlet side of the colorant supply pipe through the air delivery pipe when measuring the resin material. There is an excellent effect that the resin clogging of the colorant supply tube is eliminated, the supply amount of the colorant is stabilized, and a molded product having a stable color can be formed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a schematic configuration of an injection molding apparatus to which the present invention is applied.

FIG. 2 is a partially enlarged sectional view of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Die 2 Heating cylinder 3 Resin material 5 Colorant 23 Colorant supply pipe 34 Air delivery pipe 36 Air pump (blowing means) 60 Tank (container)

Claims (1)

(57) [Claims] 1. An injection molding apparatus for supplying a resin material and a liquid colorant into a heating cylinder, kneading and mixing the resin material with the colorant inside the heating cylinder, and filling the mixture into a mold. A container for storing the colorant, a colorant supply means for supplying the colorant in the container through the colorant supply tube to the inside of the heating cylinder, and an outlet for the colorant supply tube. Injection molding, comprising: an air delivery pipe for communicating air so as to be able to send out air; and blowing means for delivering air through the air delivery pipe to the colorant supply pipe when measuring the resin material. apparatus.