JP2726835B2 - 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 kneading the resin material with the coloring agent while melting the resin material 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, a plurality of containers for storing a plurality of colorants having different colors are provided, and each colorant in each container is heated by a heating cylinder through a dedicated colorant supply nozzle. A plurality of pumps and the like are provided to supply the inside of the heating cylinder, and by selectively driving each of these pumps and the like to change the type of the coloring agent to be supplied to the inside of the heating cylinder, the color change of the molded article is automatically performed. Some things can be done.

For example, if the colorant A is supplied into the heating cylinder through a colorant supply nozzle dedicated to the colorant, the resin material is kneaded with the colorant A while being melted inside the heating cylinder. A molded product of color A is obtained. Then, the supply of the colorant A is stopped, and the colorant B is supplied to the inside of the heating cylinder through the colorant supply nozzle dedicated to the colorant. It is kneaded with a colorant to obtain a molded product of color B.

In order to stably supply the colorant into the heating cylinder through the colorant supply nozzle, it is necessary to consider the fluidity of the colorant. Conventionally, the colorant supply nozzle is inclined obliquely upward with respect to the heating cylinder. Alternatively, the colorant is arranged vertically and the diameter of the colorant supply nozzle is set to 3 mm to 5 mm so that the colorant flows smoothly.

[0005]

However, in the above-mentioned conventional structure, due to the structure of the colorant supply nozzle, even if the supply of the colorant is stopped, the colorant remaining in the colorant supply nozzle is discharged from the colorant supply nozzle. The liquid will drip inside the heating cylinder. For this reason, even if the type of colorant to be supplied to the inside of the heating cylinder is changed when the color of the molded product is changed, immediately after that, the colorant before the color change drips from the colorant supply nozzle into the inside of the heating cylinder. Moldings of the desired color cannot be obtained,
There was a problem that the yield was poor.

SUMMARY OF THE INVENTION An object of the present invention is to provide an injection molding apparatus capable of preventing a colorant from dripping before a color change at the time of color change of a molded product and immediately molding a molded product of a desired color.

[0007]

According to the present invention, a resin material and a liquid colorant are supplied into a heating cylinder, and the resin material is melted inside the heating cylinder, kneaded with the colorant, and charged into a mold. A plurality of containers for storing a plurality of colorants having different colors, and a plurality of colorant supplies for supplying the colorants in the containers to the inside of the heating cylinder through respective dedicated colorant supply passages. Means, color changing means for selectively driving each colorant supply means to change the type of colorant to be supplied to the inside of the heating cylinder, and supplying air to each colorant supply path toward the outlet side. When changing the type of the colorant to be supplied to the inside of the heating cylinder and the plurality of air delivery paths that are communicated so as to be capable of being delivered, the air is delivered through the air delivery path to the colorant supply path through which the colorant has passed before the change. Air blowing means It is characterized in that it is.

[0008]

According to the present invention, if the type of the colorant to be supplied to the inside of the heating cylinder is changed by selectively driving each colorant supplying means by the color changing means, the resin material can be changed inside the heating cylinder. The color of the molded product can be automatically changed by being kneaded with the changed colorant while being melted.

When the type of the colorant to be supplied to the inside of the heating cylinder is changed, before the change, air is sent to the colorant supply passage through which the colorant has passed through an air sending-out path by a blowing means, and the colorant supply is changed. The colorant remaining in the road is forcibly discharged.

Therefore, when the color of the molded article is changed, the colorant before the color change does not drip from the colorant supply passage into the inside of the heating cylinder, and the molded article of a desired color can be immediately molded.

[0011]

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. Tank 60.

The mold 1 comprises 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.
Are 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 the lower part of the hopper 4 to form a resin inside the hopper 4. A material supply port 16 to which the material 3 is supplied is formed. The heating cylinder 2 is provided with a heater 17 around it and a screw 18 provided in the inside thereof along the axial direction. The resin material 3 supplied from the inside of the hopper 4 through the material supply port 16 is screwed by the screw 18. While being transferred to the nozzle 15 side, it is heated and melted by the heater 17. Screw 18 is gear 19,
The motor 20 is driven to rotate by a driving force of a driving motor 21 via the motor 20. The 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. When the screw 18 is advanced toward the nozzle 15, the resin material 3 is transferred from the nozzle 15 to the cavity through the runner 13. 12 can be ejected. 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. Between each tank 60 and the heating cylinder 2, there is provided a colorant supply pipe 23 constituting a colorant supply path, and the colorant 5 in each tank 60 is heated through each colorant supply pipe 23. It can be supplied to the inside of the cylinder 2.

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

At the intermediate portion of each flexible tube 26, there is provided a corresponding pump 28 as a colorant supply means. These pumps 28 are driven to heat the colorant 5 in each tank 60. The fluid is sent out into the 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
8 are mounted on independent support frames 32, respectively.
A switch 33 is provided as a color changing means for driving the pump 8. By operating these switches 33, the pumps 28 can be selectively driven to appropriately change the type of the colorant 5 to be supplied to the inside of the heating cylinder 2. It has become.

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 flow into the heating cylinder 2 smoothly. As shown in detail in FIG. 2, the colorant injection nozzle 27 bifurcates at an intermediate portion, and one of the nozzles is connected to a flexible tube 26, and the other is an air outlet capable of sending air toward an outlet side. An air delivery section 34 as a road is provided. An air pump 36 as a blower is connected to each of the air delivery sections 34 via an electromagnetic valve 35, and air is sent from the air pump 36 when the electromagnetic valve 35 is opened. Each of the solenoid valves 35 is controlled by a control circuit (not shown). When changing the type of the colorant 5 to be supplied to the inside of the heating cylinder 2, the air pump 36 is connected to the colorant injection nozzle 27 through which the colorant 5 has passed before the change. Then, the air is sent through the air sending section 34 only for a predetermined time.

Next, the operation will be described. At the time of molding, the resin material 3 in the hopper 4 is supplied to the inside of the heating cylinder 2 through the material supply port 16, and each of the pumps 27 is selectively driven by operating each of the switches 33, so that a desired coloring in the tank 60 is performed. The agent 5 is supplied into the heating cylinder 2 through the material supply port 16. Inside the heating cylinder 2, the rotation of the screw 18 causes the resin material 3 to turn into the colorant 5.
At the same time, the resin material 3 is transferred from the material supply port 16 side to the nozzle 15 side, and during this time, the resin material 3 is kneaded with the colorant 5 by the rotation of the screw 18 while being melted by the heater 17.

When the fixed mold 7 and the movable mold 9 are clamped 2 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 material 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.

At the time of this molding, the operation of each switch 33 selectively drives each pump 27 so that the heating cylinder 2
Is changed, the colorant 5 of another color is supplied to the inside of the heating cylinder 2 through the material supply port 16, and the supply of the colorant 5 of another color is performed in the same manner as described above. The molded article is molded, and the color of the molded article can be switched.

Here, when the type of the colorant 5 to be supplied to the inside of the heating cylinder 2 is changed, an air pump is applied to the colorant injection nozzle 27 through which the colorant 5 has passed before the change by the control of each solenoid valve 35. Air is sent from the air through the air sending section 34 for a predetermined time, and the colorant 5 remaining in the colorant injection nozzle 27 is forcibly discharged.

Therefore, when the color of the molded product is changed, the colorant 5 before the color change does not drip into the inside of the heating cylinder 2 from the colorant injection nozzle 27, and the molded product of a desired color can be formed immediately. , And the yield is improved. In addition,
The air sent from the air pump 36 to the colorant injection nozzle 27 through the air sending section 34 is discharged from the material supply port 16 to the outside through the hopper 4 and does not hinder the molding.

In the above embodiment, each air delivery section 34
Are connected to a dedicated air pump 36 via an electromagnetic valve 35, however, each air delivery section 34 may be connected to a single air pump 36 via an electromagnetic valve 35, in which case the number of parts And the cost is reduced.

In the above-described embodiment, the air supply to the colorant injection nozzle 27 is controlled by controlling the electromagnetic valve 35. However, the present invention is not limited to this. The air pumps 34 may be directly connected to dedicated air pumps 36, respectively, and the air pumps 36 may be controlled to control the delivery of air to the colorant injection nozzle 27.

[0025]

As described above, in the injection molding apparatus according to the present invention, when the type of the colorant to be supplied to the inside of the heating cylinder is changed, the colorant supply passage through which the colorant has passed before the change. Is provided with air blowing means for sending air through the air delivery path, preventing the colorant from dripping before the color change at the time of color change of the molded product, allowing the molded product of the desired color to be molded immediately and improving the yield. It has an excellent effect of doing.

[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]

 REFERENCE SIGNS LIST 1 mold 2 heating cylinder 3 resin material 5 colorant 23 colorant supply pipe (colorant supply path) 28 pump (colorant supply means) 33 switch (color changing means) 34 air delivery section (air delivery path) 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 the resin material with the colorant while melting the resin material inside the heating cylinder, and filling a mold. A plurality of containers for storing the plurality of colorants having different colors; and a plurality of colorant supply means for supplying the colorants in the containers to the inside of the heating cylinder through respective dedicated colorant supply paths. A color changing means for selectively driving the colorant supply means to change the type of the colorant to be supplied to the inside of the heating cylinder; and directing the colorant supply paths toward the outlet side. A plurality of air delivery paths that communicate with each other so that air can be sent out, and when changing the type of the colorant to be supplied to the inside of the heating cylinder, the colorant supply path through which the colorant has passed before the change. Above air Injection molding apparatus characterized in that it comprises a blower means for delivering air, a through Detchi.