JPS6343053Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field The present invention relates to a coloring device for an injection molding machine.

(B) Prior Art There is a method of mixing a liquid pigment with a non-colored resin material in order to obtain a colored molded product using the non-colored resin material. In order to mix a liquid pigment with a non-colored resin, conventionally, the liquid pigment has been supplied to a hopper section, which is a resin inlet of an injection molding machine, through a pipe, a hose, or the like. The pellet-shaped resin material and liquid pigment supplied from the hopper are melted and kneaded by a screw in a cylinder and injected into a mold. In this way, a colored molded article is obtained. However, when the liquid pigment is supplied to the hopper in this way, there are problems in that the working time is longer and the resin material is lost more when changing colors. In other words, after molding with a certain color, the liquid pigment of that color will adhere to the inner surface of the cylinder, screw surface, etc. of the injection molding machine, and in this state, even if liquid pigment of a different color is introduced, it will not work. , because the liquid pigment of the first color remains, it is not possible to immediately obtain a colored molded product of another color. Immediately after adding a liquid pigment of a different color, the color becomes a mixture of two types of liquid pigments, and the product has no choice but to be discarded as a defective product. Therefore, until the liquid pigment of the first color is completely removed, the molding operation is wasted, reducing production efficiency, and the resin material is wasted during this time.

(c) Purpose of the invention The purpose of the invention is to provide a coloring device for an injection molding machine that can quickly change colors and does not waste resin material.

(d) Structure of the invention The invention achieves the above object by providing a coloring device between the cylinder head and the mold of an injection molding machine. That is, the coloring device for an injection molding machine according to the present invention includes an adapter that is attached to the tip of the cylinder head of the injection molding machine and has a resin passage, a kneading nozzle that is connected to the tip of the adapter, and a kneading nozzle that intersects with the resin passage in the adapter. A valve hole is provided to separate the resin passage into an upstream part on the cylinder head side and a downstream part on the kneading nozzle side, and a resin communication hole and a liquid pigment passage hole are installed in the valve hole so as to be movable in the axial direction. The spool includes a spool to be inserted, a spool moving device capable of moving the spool in the axial direction and stopping at a first position or a second position, and a tank capable of supplying liquid pigment to the liquid pigment passage hole of the spool. The resin communication hole and the liquid pigment passage hole of the spool communicate with each other when the spool is in the first position. and the liquid pigment passage hole is arranged such that when the spool is in the second position, the upstream and downstream portions of the resin passage of the adapter are disconnected and the liquid pigment passage hole communicates with the upstream portion of the resin passage of the adapter. There is.

(e) Examples Examples of the present invention will be described below with reference to Nos. 1 and 2 of the attached drawings.
This will be explained based on the diagram.

The coloring device 10 according to the invention is installed between the cylinder head 12 and the mold 14 of an injection molding machine. The coloring device 10 includes an adapter 16, a kneading nozzle 18, a spool 20, a fluid pressure cylinder 22,
It has a tank 24 and the like. The adapter 16 is
It is screwed concentrically to the tip of the cylinder head 12. The adapter 16 is connected to the cylinder head 1
It has a resin passage 26 that communicates with the second resin reservoir. The resin passage 26 is separated into an upstream part 26a and a downstream part 26b by a valve hole 28 provided in the adapter 16 so as to be perpendicular thereto. A spool 20 is fitted into the valve hole 28, which is a hole with a circular cross section, so as to be freely movable in the axial direction. The spool 20 has a resin communication hole 30 and a liquid pigment passage hole 32. The resin communication hole 30 passes through the spool 20 in a direction perpendicular to its axis. The liquid pigment passage hole 32 has an opening 32a on the right side of the spool 20 in FIG. 1, and an opening 32b on the upper end surface. A pipe line 3 is connected to the opening 32b on the upper end surface side of the liquid pigment passage hole 32 by a joint 34.
6 is connected. Conduit 36 carries liquid pigment 38
It communicates with a tank 24 containing a. The spool 20 is connected to a piston rod 22a of a hydraulic cylinder 22, which is a spool moving device.
That is, a metal fitting 42 is attached to the upper end surface of the spool 20 in FIG. 1 by a bolt 40, and a piston rod 22a of the fluid pressure cylinder 22 is connected to this metal fitting 42. In addition, metal fittings 4
2 has an opening 42a through which the conduit 36 passes.
is provided. The hydraulic cylinder 22 is secured by bolts 50 to a mounting plate 48 which is attached by bolts 46 to a bracket 44 secured to the adapter 16. The bracket 44 has an opening 44 through which the conduit 36 passes.
It has a. The hydraulic cylinder 22 is strokeable between a first position in which the spool 20 is stopped in the state shown in FIG. 1 and a second position in which the spool 20 is stopped in the state shown in FIG. When the spool 20 is in the first position, the resin communication hole 30 is located concentrically with the resin passage 26 (that is, the upstream part 26a and the downstream part 26 of the resin passage 26
b are in communication with each other through the resin communication hole 30). Moreover, when the spool 20 is in the second position,
The opening 32a of the liquid pigment passage hole 32 is the resin passage 26.
It communicates with the upstream portion 26a of. That is, the stroke of the fluid pressure cylinder 22 is made equal to the distance between the resin communication hole 30 and the opening 32a of the liquid pigment passage hole 32. A kneading nozzle 18 having a mixing tip is connected to the tip of the adapter 16. The kneading nozzle 18 can come into contact with the mold 14.

Next, the operation of this embodiment will be explained. 1st
The figure shows the state in which injection has been completed. From this state, the screw 52 in the cylinder head 12 is rotated to melt, knead, and weigh the uncolored resin. The screw 52 is moved back by a dimension L in the right direction in FIG. 1 for measurement. Next, the fluid pressure cylinder 22 is operated to switch the spool 20 from the first position to the second position. This state is shown in FIG. Next, the screw 52 is further retreated by the S dimension without rotating. As the screw 52 retreats, the resin reservoir in the cylinder head 12 becomes under negative pressure, so the liquid pigment 38 in the tank 24 flows through the pipe 36, the joint 34, and the liquid pigment passage hole 32 of the spool 20. The resin passage 26 of the adapter 16
is sucked into the upstream portion 26a of. The amount of liquid pigment 38 sucked is determined by the stroke S dimension of the screw 52. Note that the tank 24 is the adapter 1.
6, and the liquid pigment 38 is easily sucked in (instead of installing the tank 24 at a higher location, it may be pressurized by a pump). When the screw 52 strokes by the S dimension and suction of the liquid pigment is completed, the fluid pressure cylinder 22 is operated to return the spool 20 to the first position again. Next, when the screw 52 is advanced to the left in FIG. The mixture passes through the kneading nozzle 18 and is injected into the mold 14. When the molten resin and liquid pigment pass through the kneading nozzle 18, they are kneaded by the mixing tip of the kneading nozzle 18, and the liquid pigment is uniformly dispersed within the molten resin. The molten resin and liquid pigment kneaded in this way are molded in the mold 14 to form a uniformly colored molded product. With the above steps, one molding cycle is completed. Thereafter, by repeating the same operation, colored molded products can be continuously molded.

After molding is performed using a liquid pigment of a predetermined color, if you want to change the color of the liquid pigment, remove the entire coloring device 10 you have been using and replace it with another coloring device 10 with exactly the same configuration. (However, only the color of the liquid pigment 38 contained in the tank 24 is different.) Just attach it. That is, the first
Everything other than the cylinder head 12, screw 52 and mold 14 shown in the figure will be replaced. After replacing the coloring device 10, a colored molded product in a new color can be obtained immediately. This is because the liquid pigment of the color that was used just before is not left anywhere. Therefore, there is no need to carry out wasteful injection molding for color changes as in the past, and production efficiency is improved and loss of resin material can be completely eliminated.

Note that since the amount of liquid pigment to be injected is determined by the stroke size S of the screw 52 as described above, the amount of liquid pigment to be injected can be set as desired.

(f) Effects of the invention As explained above, the coloring device for an injection molding machine according to the invention includes an adapter that is attached to the tip of the cylinder head of the injection molding machine and has a resin passage, and a coloring device that is connected to the tip of the adapter. A kneading nozzle, a valve hole provided in the adapter to intersect with the resin passage and separating the resin passage into an upstream part on the cylinder head side and a downstream part on the kneading nozzle side, a resin communication hole and a liquid pigment passage hole. A spool that is movably inserted into the valve hole in the axial direction,
Move the spool axially to the first or second position.
It has a spool moving device that can be stopped at the first position, and a tank that can supply liquid pigment to the liquid pigment passage hole of the spool. At one time, the resin communication hole communicates with the upstream and downstream parts of the resin passage of the adapter, and the liquid pigment passage hole and the resin passage of the adapter are in communication, and when the spool is in the second position, the resin passage of the adapter communicates with the upstream and downstream parts of the resin passage. The liquid pigment passage hole is arranged so that it is isolated from the downstream part and communicates with the upstream part of the resin passage of the adapter, improving production efficiency and reducing loss of resin material during color changes. do.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the coloring device of the injection molding machine according to the present invention (a diagram showing the state before the start of molding operation), and Fig. 2 is the state of the coloring device of the injection molding machine shown in Fig. 1 when liquid pigment is inhaled. FIG. 10... Coloring device, 12... Cylinder head, 14... Mold, 16... Adapter, 18...
...Kneading nozzle, 20...Spool, 22...Fluid pressure cylinder, 22a...Piston rod, 24...
... Tank, 26 ... Resin passage, 26a ... Upstream section, 26b ... Downstream section, 28 ... Valve hole, 30
... Resin communication hole, 32 ... Liquid pigment passage hole, 34
...Joint, 36...Pipe line, 38...Liquid pigment, 4
0...Bolt, 42...Metal fitting, 44...Bracket, 46...Bolt, 48...Mounting plate, 50...
Bolt, 52... Screw.

Claims (1)

[Scope of utility model registration request] An adapter that is attached to the tip of the cylinder head of an injection molding machine and has a resin passage; a kneading nozzle that is connected to the tip of the adapter; and a kneading nozzle that is installed on the adapter to intersect with the resin passage and connect the resin passage upstream of the cylinder head. A valve hole that is separated into a part and a downstream part on the kneading nozzle side, a resin communication hole and a liquid pigment passage hole, and a spool that is inserted into the valve hole so as to be movable in the axial direction; and a tank capable of supplying liquid pigment to the liquid pigment passage hole of the spool. When the spool is in the first position, the resin communication hole communicates the upstream and downstream parts of the resin passage of the adapter, and the liquid pigment passage hole and the resin passage of the adapter are cut off, and the spool is in the second position. A coloring device for an injection molding machine, in which the upstream and downstream parts of the resin passage of the adapter are sometimes blocked and the liquid pigment passage hole is arranged so as to communicate with the upstream part of the resin passage of the adapter.