JPH0450101Y2 - - Google Patents

Description

[Detailed Description of the Invention] Field of Industrial Application The present invention relates to an injection molding machine, and more particularly to a molding machine that pressurizes and injects molten resin while rotating a screw in a cylinder.

〓Summary of the invention〓 This invention connects an auxiliary injection device so as to face near the tip of the cylinder of an injection molding machine, attaches a torpedo to the tip of the cylinder, and injects pigment using this auxiliary injection device. However, by mixing the torpedo with molten resin through selected holes in the torpedo, a molded article having a marble pattern or a striped pattern can be obtained.

<Prior Art> When a pigment is mixed into a molded body and the pigment is not sufficiently mixed into the molded body, a molded body having various patterns such as a marble pattern can be obtained. Therefore, conventionally, a plunger-type injection molding machine is used, a supply device for supplying pigment is connected to the nozzle side of the injection molding machine, and the pigment is mixed by this device to obtain a molded article with a marble pattern. I was doing it.

〓Problems that the invention aims to solve〓 However, with such conventional devices, the plasticizing ability is lower than that of the screw type because the plunger is used to extrude the resin. It has the disadvantage of low production capacity. Furthermore, since the equipment becomes larger, there is a drawback that the cost of the device increases. Therefore, if such equipment is used to produce injection molded products with marble-like patterns,
The disadvantage is that the cost of the molded product is high.

The present invention was devised in view of these problems, and the purpose is to provide an injection molding machine that can reduce the production cost of injection molded products having marble-like patterns and various pattern designs. That is.

〓Means for solving the problem〓 The present invention is a molding machine that pressurizes and injects molten resin while rotating a screw in a cylinder. Connect the device and
A torpedo is attached to the tip of the cylinder, the pigment is injected by the auxiliary injection device, and the molten resin is mixed through selected holes in the torpedo.

〓Effect〓 Therefore, according to the present invention, high productivity can be obtained by using an injection molding machine having a screw with high plasticizing ability, the cost of molded products can be reduced, and the injection molding machine can also be downsized. This also reduces the cost of the device.

〓Embodiment〓 Fig. 1 shows an injection molding machine according to an embodiment of the present invention. installed. Also cylinder 1
A screw 12 for extruding molten resin is rotatably disposed inside the screw. A nozzle 14 is connected to the front end of the cylinder 10 via a base 13. Incidentally, a torpedo 15 for forming various patterns and patterns is built in the connecting portion between the base 13 and the nozzle 14.

An auxiliary injection device 20 is provided so as to be connected to the through hole 19 of the die 13 of such a screw type injection molding machine. This injection device 20 includes a cylinder 21, and a torpedo 22 and a plunger 23 are provided within the cylinder 21. The plunger 23 is connected to a hydraulic cylinder 24, and a hopper 26 is connected to a supply port 25 provided diagonally in the cylinder 21. The hopper 26 allows the auxiliary injection device 20 to supply pigment.

The torpedo 15 arranged inside the nozzle of the cylinder 10 is a piece that is a separate member from the cylinder 10, as shown in FIGS. Holes 31 are provided concentrically, and eight holes 32 extending in the axial direction are further provided at intermediate positions. This intermediate hole 32 is for supplying pigment through it. Furthermore, a single large-diameter center hole 33 is formed on the center side. Also Torpedo 15
An outer circumferential groove 34 is formed on the outer circumferential side of the
An introduction hole 35 communicating with this outer circumferential groove 34 is formed. The pigment supplied from the auxiliary injection device 20 is supplied to the intermediate hole 32 through the outer circumferential groove 34 and the introduction hole 35.

In the above configuration, the screw 12 of the cylinder 10 allows the injection molding machine to
The molten resin is injected under pressure. The resin is injected through the through hole 19 of the base 13 and the nozzle 14. On the other hand, a pigment is stored in the hopper 26, and this pigment is extruded from the lower end of the cylinder 21 by the hydraulic cylinder 24 of the auxiliary injection device 20, and this pigment enters the through hole 19 of the nozzle 13. will be supplied.

The pigment injected by the auxiliary injection device 20 is adapted to pass through selected holes in the torpedo 15 before being mixed directly with the molten resin. That is, the pigment injected by the auxiliary injection device 20 is guided from the outer circumferential groove 34 of the torpedo 15 to the introduction hole 35 extending in the radial direction, and is further supplied to the hole 32 at an intermediate position. Then, it is discharged from the tip of the torpedo 15 through this hole 32. In other words, the pigment is Torpedo 1
After passing through the inside of the cylinder 10, it is extruded into the molten resin at the tip of the cylinder 10.

Therefore, in this part, the pigment is mixed with the molten resin extruded from the screw-type cylinder 10. However, the pigment is hardly mixed with the molten resin and is locally mixed into the molten resin. Moreover, since this resin is stretched in the axial direction of the cylinder 10, it imparts a marble-like pattern to the molded product, thereby providing an injection molded product with a marble pattern.

In this way, the injection molding machine of this embodiment is not a plunger type injection molding machine, but a general-purpose high-speed injection molding machine having a screw 12 and an ultra-compact auxiliary injection device 20.
The main machine injects the main resin, and the auxiliary injection device 20 supplies pigment. By adjusting the conditions such as the torpedo 15 that forms the pattern and the injection timing, an injection molded product with a marble pattern or a striped pattern can be obtained at high speed.

In this way, instead of using a plunger type injection molding machine as the main machine, we use a screw rotary injection molding machine with high plasticizing capacity to obtain injection molded products with various patterns, which makes it possible to increase the height of the main machine. Productivity reduces the cost of molded products. Furthermore, it becomes possible to downsize the entire device, thereby making it possible to reduce the cost of the device. In addition to injection molded products, this technique can also be used to mold blow molded products and extrusion molded products.

Next, a modified molding machine will be explained with reference to FIG. 6. The molding machine according to this modification includes an auxiliary injection device 2
The mounting position of 0 corresponds to the tip of the screw 12 of the cylinder 10 of the main engine, and it is connected to the main engine at this position. That is, the injection port of the auxiliary injection device 20 is arranged at a position where the spiral rotates one turn from the tip of the screw 12. Therefore, according to this structure,
The pigment extruded by the auxiliary injection device 20 will be slightly mixed with the molten resin at the tip of the screw 12, after which the pigment will pass through specific holes in the torpedo 15. Therefore, the mixing of pigment and resin is more uniform than in the apparatus shown in FIG. Therefore, molded products having various patterns with slightly different textures are obtained. Note that the other configurations are substantially the same as those of the above embodiment.

Effects of the invention As described above, the present invention connects the auxiliary injection device so as to face near the tip of the cylinder, attaches a torpedo to the tip of the cylinder, and injects the pigment using this auxiliary injection device. The molten resin is mixed with the molten resin through selected holes in the torpedo. Therefore, according to such a structure, high productivity can be obtained by using a screw type molding machine with high plasticizing ability, and it is possible to reduce the cost of molded products. Also, various designs or patterns can be obtained depending on the arrangement of the holes in the torpedo. Furthermore, it is possible to downsize the entire device and reduce its cost.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of an injection molding machine according to an embodiment of the present invention, Fig. 2 is a front view of the torpedo, Fig. 3 is a rear view of the same, Fig. 4 is a sectional view taken along the line ~ in Fig. 2, Figure 5 is a sectional view taken along the line ~ in Figure 4;
FIG. 6 is a longitudinal sectional view of a modification of the injection molding machine. In addition, in the symbols used in the drawings, 10... cylinder, 12... screw, 13... cap, 14...
... Nozzle, 15 ... Torpedo, 19 ... Through hole, 20 ... Auxiliary injection device, 21 ... Cylinder,
23...Plunger, 24...Hydraulic cylinder, 2
6...hopper, 32...hole at intermediate position.

Claims (1)

[Scope of utility model registration request] In a molding machine that pressurizes and injects molten resin while rotating a screw in a cylinder, an auxiliary injection device is connected so as to face near the tip of the cylinder, and a torpedo is attached to the tip of the cylinder. An injection molding machine, characterized in that the auxiliary injection device injects pigment and mixes it with the molten resin through selected holes in the torpedo.