JP2928968B2 - 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 an injection molding apparatus for producing a colored plastic molded product.

[0002]

2. Description of the Related Art In order to obtain a colored injection molded product, the following means are generally employed. As a first example, at the stage of manufacturing resin pellets as a raw material of a molded article, a resin material is colored by adding a coloring agent such as a dye or a pigment in advance,
There is a molded product which is molded as it is to be molded into the color.

As a second example, there is a method in which a liquid colorant is injected into a pellet supply hole for supplying resin pellets to a supply cylinder, and the mixture is heated and stirred in the cylinder.

In a second example, a tank filled with a colorant of an arbitrary color is used, and the colorant is supplied to a resin material supply path by a pump to change the coloring of a molded product. doing. More specifically, a coloring agent supply means formed by connecting a flexible tube to a coloring agent suction pipe provided in a tank, and a position where the tube is pressurized and thereby deformed, is sequentially moved from the upstream side to the downstream side. A colorant injection device is used, which is a set of a pump and a pump capable of sending the colorant in the tube to the resin material supply path. Further, such a coloring agent injection device is constituted by a tube in which a tube is hung between a rotor provided with a plurality of rollers on an outer peripheral portion and a housing surrounding the rotor, and supplies the coloring agent according to the rotation of the rotor. However, a computer for controlling the pump is also required to control the supply amount and the injection timing of the colorant.

[0005]

In the second example of the above prior art, there is no problem in the case where only a single color is always colored.
In the case where a plurality of colors are appropriately applied, it is necessary to replace the tank, or replace the tank with a different colorant injection device every time when a different color is used.

However, in the former case, even if the tank is replaced, since the colorant of the previously used color remains in the tube, it must be drained cleanly beforehand, which requires a troublesome work. It also has disadvantages such as inconvenient color synthesis. In the latter case, if a large number of colorant injection devices are used,
Accordingly, the cost of the apparatus is increased, and concomitantly, control means such as a computer for controlling each of the colorant injecting apparatuses is required, which causes an increase in the cost of coloring.

SUMMARY OF THE INVENTION An object of the present invention is to provide an injection molding apparatus having a simple structure and a low cost, by selecting an arbitrary colorant from a large number of colorants, enabling a molded article to be colored in a desired color. Is to do.

[0008]

In order to achieve the above object, an injection molding apparatus according to the present invention comprises: a mold having a cavity having an arbitrary shape; resin material supply means for supplying a resin material into the cavity; A plurality of colorant supply means capable of injecting a colorant into the resin material supply means, and at least one of the plurality of colorant supply means is selected, and a colorant is supplied from only the selected colorant supply means to the resin. Having a pump for injecting into the material supply means, the resin material supply means being capable of supplying the colorant injected by the selected colorant supply means to the cavity in a state mixed with the resin material as follows.
Means .

[0009] In the above means, the colorant supply means comprises:
A tank containing a colorant of an arbitrary color, and a flexible tube communicating the tank with a resin material passage in the resin material supply means, wherein the pump is rotatably provided; A plurality of rotors around which the tube is wound, rollers provided rotatably on the outer periphery of the rotor, and rotor rotating means for selectively rotating at least one of the plurality of rotors. Have . By the rotation of the rotor selected in this way, the tube wound around the outer periphery of the rotor is pressurized via the roller, and the colorant in the tube is pushed out toward the resin material passage.

[0010]

According to the present invention, at least one of a plurality of colorant supply means is selected, and a colorant is injected into the resin material supply means only from the selected colorant supply means by a pump, and only the selected colorant is supplied to the resin material. Since the mixture is supplied to the cavity in a mixed state, a molded product of the selected color can be easily obtained.

The selection of the colorant supply means is performed by selectively rotating the rotor supporting the roller for pressing the tube by the rotor rotation means, and the colorant of the selected specific color is selected by the selected colorant. agents Ru is forced to flow resin material passage is supplied to the resin material from only the supply means.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an injection molding apparatus according to the present invention includes a mold 2 mounted on a molding machine main body 1, a resin material supply means 3 for supplying a resin material to the mold, and a resin material supply means. It comprises a plurality of colorant supply means 4 for supplying a colorant such as a dye or a pigment, and a pump 5 for selectively injecting a colorant from the colorant supply means 4 into the resin material supply means 3.

The mold 2 includes a fixed mold plate 7 (hereinafter, collectively referred to as a “fixed mold”) fixed to a fixed attachment plate 6 of the molding machine main body 1 and a movable attachment plate 8. The movable side mold plate 9 (hereinafter, collectively referred to as “movable side mold”) and guide shafts 10, 10, etc. The movable mold 9 can be advanced and retracted by a ram 11 of a movable drive means (cylinder) provided in the molding machine body 1. When the movable-side mold 9 moves forward and comes into contact with the fixed-side mold 7 to be in a mold-clamped state, a cavity 12 having an arbitrary shape is defined between the two mold plates 7 and 9. The nozzle 14 of the resin material supply means 3 is fitted into a sprue portion provided in the fixed mold 7 , and the cavity 12 is inserted through the runner 13.
A resin material can be supplied inside.

The resin material supply means 3 includes a pellet storage hopper 15 provided above the center of the molding machine main body 1 and a cylinder 16 for feeding the resin material stored in the hopper 15 toward a mold. . A resin material passage 17 communicating with the hopper 15 and a resin material passage 17
A screw 18 for feeding the resin material inside to the nozzle 14 side is provided rotatably. The screw 18 has a gear 19,
It can be rotated by a drive motor 21 via 20 and can be advanced and retracted by a drive cylinder 37. A heater 22 is mounted around the cylinder 16 so that the resin material passing through the cylinder can be heated and melted.

In this embodiment, three colorant supply means 4 are provided. These colorant supply means 4 include a colorant tank 24 containing dyes or pigments of different colors.
And a flexible tube 25 communicating the tank with the resin material passage 17 and a colorant injection nozzle 23 attached to the tip of each tube. Each tube 25 can communicate the tank 24 with the resin material passage 17, and can send out the colorant stored in the tank to the resin material passage when the pump 5 described later is driven.

As shown in FIGS. 2 and 3, the pump 5 has a housing 26 in which three rotors 27 are independently rotatably mounted on a support shaft 28 and a pipe shaft 29. Each rotor 27 has a substantially triangular plate shape with each side formed in a concave portion, and the roller 30 is rotatably disposed in a groove formed at each apex of the rotor 27. Each rotor 27
The rotor can be selectively rotated in the housing 26 by the rotor rotating means 31.

The rotor rotating means 31 comprises a motor 32, a drive pinion 33, a gear 34 and a pipe shaft 29. The selection of the rotor to be rotated is made by the shift lever 3
5 is moved by a cylinder 36, and the gear 34 and the pipe shaft 29 are slid along the support shaft 28. The pipe shaft 29 is provided with a key 29a having a length equal to the width of the boss of the rotor 27, and allows any one of the three rotors to rotate as the pipe shaft moves.

The gear 34 has a groove 3 for the shift lever.
4a is formed, and when the gear 34 slides along the support shaft 28 via the shift lever 35 by the cylinder 36, the pipe shaft fixed thereto also slides. Since the drive pinion 33 of the rotor rotating means 31 has a tooth profile in a range covering the movement range of the gear 34, the gear 3
4 can always transmit torque.

An intermediate portion of a flexible tube 25 is wound around the outer periphery of the rotor 27 along the inner periphery of the housing 26 constituting the pump 5. The tube 25 is deformed toward the inner peripheral surface side of the housing 26 by the rotation of the rotor 27 and the rotation of the roller 30 as well as the rotation of the roller 30 (see FIG. 3), thereby reducing the internal cross-sectional area. The position of the reduced cross-sectional area can be moved counterclockwise along the inner circumference of the housing.

Next, the operation will be described. Hopper 15
A resin material such as polyvinyl chloride (PVC) is accommodated therein, and "Novo Liquid Color" (trade name: manufactured by Novotech Japan Co., Ltd.) is employed as a coloring agent. The plurality of tanks 24 contain colorants of different colors, respectively, and are connected to flexible tubes 25, respectively.

Next, the operation of the cylinder 36 moves the shift lever 35 to determine the rotating rotor 27 (see FIG. 3). The tank that sends out the colorant is specified by the specification of the rotor 27, and the color of the colorant is selected.

When the mold 2 is clamped, the screw 18 of the resin material supply means 3 advances, and the resin material fed from the hopper 15 through the resin material passage 17 into the cylinder is Is heated by the heater 22 to be in a molten state and sent out of the nozzle into the cavity 12 at a high speed. At this time, the pump 5
The colorant of the selected color is flushed into the resin material passage 17 through the, and is stirred by the rotation of the screw 18 in the cylinder 16, and the colorant is mixed into the resin material to form a predetermined color. , Is supplied into the cavity by the advancement of the screw 18. The resin material solidifies in the cavity, and a molded product of a desired color is obtained.

When changing the color of the molded product to a different color, the shift lever 35 is moved by the cylinder 36,
The rotating rotor 27 is switched to another colorant tank 24.
What is necessary is just to send out the colorant of another color accommodated in the resin material into the resin material.

Here, the control of the pump 5 will be described.
The pump 5 is fixed to a frame 5a independent of the molding machine main body 1, and a control panel 5b is attached to this frame. The panel 5b is provided with a switch for designating the rotor to be rotated and the rotational speed of the rotor, meters for indicating the color of the colorant being supplied and the remaining material, and the like. A computer for controlling the colorant supply conditions according to the operation of 5b is incorporated. In this way, it is possible to control the coloring of the molded article only by operating the panel. In this embodiment, the number of the tanks 24 constituting the colorant supply means 4 is three, but the number is not limited and can be increased or decreased as needed. It is natural that the number of tubes 25 and the number of rotors 27 of the pump 5 are correspondingly increased or decreased. Further, the rotor rotating means 31 is also configured to selectively rotate one rotor. However, the number of the rotors may be arbitrary, and a molded product of a synthesized color may be obtained. Will be possible.

Various types of coloring agents such as dyes and pigments can be used, and various resin materials such as polyacetal (POM) and polyethylene (PE) can be used as the resin material.

[0026]

According to the present invention, a resin material for an injection molding apparatus is provided.
Pump as colorant supply means provided in supply means
Supplies a colorant selected from a plurality of rotors.
The color of the colorant by rotating the rotor
The color of the molded product can be easily changed.
It becomes possible to make it.

The colorant is supplied as a colorant supply means.
Using a contained tank and flexible tubing,
Because it is supplied by squeezing with a roller, colorant
No longer flows directly in the same passage of the pump.
You. Therefore, mixing of the color does not occur even if the inside of the pump is not washed every time the color of the molded article changes, and there is an effect that the number of steps for changing the color can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a main part of one embodiment of the present invention.

FIG. 2 is an explanatory diagram of main parts of a colorant supply unit, a pump, and a resin material supply unit.

FIG. 3 is an explanatory view showing a cross section of a rotor rotating means of the pump.

[Explanation of symbols]

 2 Mold 3 Resin material supply means 4 Colorant supply means 5 Pump 12 Cavity 17 Resin material passage 24 Tank 25 Tube 27 Rotor 30 Roller 31 Rotor rotation means

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-156312 (JP, A) JP-A-4-250012 (JP, A) JP-A-4-331116 (JP, A) JP-A-5-205 57750 (JP, A) JP-A-5-138651 (JP, A) JP-A-5-337947 (JP, A) JP-A-6-297509 (JP, A) Japanese Utility Model Laid-Open No. 63-25512 (JP, U) (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 45/18 B29C 31/02

Claims (1)

(57) [Claims] 1. A mold having a cavity of an arbitrary shape, a resin material supply means for supplying a resin material into the cavity, and a plurality of colorant supply means capable of injecting a colorant into the resin material supply means. A pump for selecting at least one of the plurality of colorant supply means and injecting the colorant into the resin material supply means only from the selected colorant supply means, The colorant injected by the selected colorant supply means can be supplied to the cavity in a state mixed with the resin material , and the colorant supply means contains the colorant of any color.
Tanks and trees in the tank and the resin material supply means.
A flexible tube communicating with the oil material passage, wherein the pump is rotatably provided and the tube is
A plurality of rotors each of which is multiplied,
A roller rotatably disposed on the outer peripheral portion;
Selectively rotate at least one of the rotors
Rotating means for rotating the selected rotor
As a result, the chip hung around the rotor
The tube is pressurized via the roller, and the
The colorant is forced to flow toward the resin material passage.
Injection molding apparatus, characterized in that that.