JPS6025720A - Injection molder - Google Patents

Abstract

PURPOSE:To obtain an injection molder whose structure is simple and that is excellent in efficiency for plasticizing a molding material, by attaching a nozzle in front of a heating cylinder for heating and melting a molding material in the form of lumpy solid pieces by heaters arranged around the outer circumference thereof, and carrying out injection by an injection plunger. CONSTITUTION:A plurality of rodlike infrared ray lamps 9 are arranged with a certain space therebetween around the outer circumferential surface of a transparent glass pipe 8 arranged coaxially with a metal cylindrical nozzle 11 and a reflective plate 10a is situated outside thereof. A molding material 13 that has been extruded into the form of cylindrical lumpy solid pieces whose cross-sectional shape is definite is loaded into the glass pipe 8 from an accommodating hole 17a of a magazine 17 by an injection plunger 14. After melting of the molding material, the plunger 14 is further moved forward to inject the melted raw material into the mold via the nozzle 11.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an injection molding machine for plastics, etc.

Conventional configuration and problems The conventional injection molding machine has a concrete example as shown in Fig. 1.
K, which melts the plastic raw material in the hopper 6, rotates the screw l via the speed reducer 5 due to the rotation of the motor 4. The raw material fed into the cylinder 2 from the hopper 6 is plasticized by the shear heat generated by the 10 rotations of the screw and by the heating from the external heater 7, and is accumulated in the front part of the cylinder 2.

Next, the injection cylinder 3 is operated to move the scree 1 forward and inject the molten forest material.

However, this injection molding machine has a complicated structure because the screw 1 performs rotational movement and axial back-and-forth movement, and it is necessary to have a drive source for both movements. Furthermore, the machining of the scree itself is complicated, and it is necessary to provide a check valve or the like (not shown) at the tip of the scree, and since a large number of heaters 7 are installed outside the cylinder 2, the heater 7 There were also many disconnection accidents. In addition, the temperature rise time is long, and it is necessary to turn on the heater 7 20 to 30 minutes before the start of molding, which may cause a big problem, for example, when connecting the molding machine and the assembly line or synchronous operation. Ta.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an injection molding machine which has a simple structure and is excellent in plasticizing efficiency of molding material.

Structure of the Invention The present invention provides a heating cylinder (for example, a glass tube) for heating and melting a lumpy solid piece of molding material, which has a heater (for example, an infrared rung or a high-frequency dielectric heating electrode) on its outer circumferential surface and is inserted inside the cylinder. This cylinder includes a nozzle attached to the front surface of the cylinder, and an injection lunge that injects the molding material heated and melted in the cylinder into the mold through the nozzle.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 2 to 4. In FIG. 2, reference numeral 8 denotes a transparent glass tube, which is coaxially connected to a cylindrical nozzle 11 made of tubular metal, and has the same inner diameter. A plurality of rod-shaped infrared rungs 9 are arranged at equal intervals on the outer peripheral surface of the glass tube 8, and a reflector 10a is provided on the outside of the bar-shaped infrared rungs 9, and the light from the infrared rungs 9 is reflected by this reflector 10a. It is reflected in the direction of the glass tube 8. A water jacket 10 for cooling the reflector is provided outside the reflector 10a. Reference numeral 12 denotes a heat-retaining heater for preventing the temperature of the molten molding material from decreasing.

The glass tube 8 is filled with a molding material 13 in the form of a pit-shaped solid piece that has been previously formed into a cylindrical shape with a constant cross-sectional shape by extrusion molding or the like. As shown in FIGS. 2 and 3, this molding material 13t/'i is fed to a predetermined position from the parts feeder 22 by the guide rail 19,
1 in the magazine 17 by M separate cylinder 20
Insert them one by one. 18 is a piston guide of the feed cylinder 20, which is connected to the molding material storage hole 1 of the magazine 17.
7a so that the center position coincides with the center position.

The magazine 17 is rotatably supported by a shaft tl, and the molding material 13 inserted into the storage hole 17a is transferred to the glass tube 8 and the injection cylinder 1.
Transfer between 5 and 5.

The molding material 13 stored in the storage hole 17a is sequentially fed by the rotation of the magazine 17 and reaches the discharge section 17b.

The molded forest material [3] that has reached the discharge section 17b is accurately inserted into the glass tube 8 by the injection granger 14 of the cylinder 15, and is heated and melted by the infrared ray rung 9. Molten M
! I! After that, the granger 14 moves further forward, and the molten raw material is injected.

Cylinder 15tJ: A two-stage cylinder (not shown) may be used, but when the granger 14 advances to a predetermined position when inserting the molding material, the stopper 16ft is activated so that it hits stage m21 of the plunger 14. . After the molding material 13 is heated and melted, the stopper 16 is returned to its original position, and the granger 14 is smoothly advanced to perform injection from the nozzle. After injection and pressure holding are completed, the granger 14 is moved back to its original position, the magazine 17 is fed one station, and the IJ operations are repeated again.

Incidentally, instead of the cylindrical nozzle 11, as shown in FIG. 4, the entire tube may be constructed of a glass tube 8', and a metal nozzle 23 may be fitted at the tip thereof.

Moreover, instead of the rod-shaped infrared lamp 9 as shown in the buttons in FIGS. 2 and 4, a plurality of rings arranged concentrically around the outer periphery of the crow tubes 8 and 8' as shown in FIG. 5 or 6 may be used. A shaped infrared rung 24 can be used. A water jacket 25 is attached to this infrared lamp 24 and has a reflecting plate 25a having the same shape on its inner surface.

Further, as shown in FIG. 7 or 8, a glass tube 8
．． An electrode 26 for high frequency dielectric heating is arranged on the outer periphery of 8',
The molding gain may be melted by applying a voltage.

In this way, near-infrared light #fc/i is used to melt the molded material 13.
By using high frequency dielectric, it takes only a few minutes to reach a predetermined melting temperature, which is extremely short compared to conventional heater heating, making it easy to restart molding after interruption. Furthermore, by changing the raw material from the conventional granular form to a lump form, it is possible to perform melting with good thermal efficiency, and the plasticizing capacity is also greatly improved.

Effects of the Invention According to this invention, since the raw material is melted from the outside using infrared a or high-frequency dielectric, the plasticization time is shorter compared to the conventional scree and band heater methods, and even bulk molding materials can be plasticized in a short time. It can be heated and melted, and the structure is also simple.

On the other hand, by forming the molding material into predetermined solid pieces using an extruder, etc., it is possible to avoid mixing of raw materials.

Since the pigment is well dispersed and there is no problem of dust that occurs when using granular raw materials, it can be used next to the assembly line and is suitable for precision molded parts that do not want to clump. .

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional in-line screw type injection molding machine, Fig. 2 is an explanatory diagram of an embodiment of the present invention, Fig. 3 is an explanatory diagram showing a molding material transfer mechanism, and Fig. 4 is an explanatory diagram of a nozzle. Figures 5 and 6 are explanatory diagrams of other glass tubes equipped with ring-shaped infrared rungs, and Figures 7 and 8 are explanatory diagrams of glass tubes equipped with high-frequency dielectric heating electrodes. Required for explanatory diagrams. 8...Glass tube, 9.Door outside line Ranno, II, 23...
Nozzle, 13... Molding material, 14 Plunger. 15. Cylinder, 17. Magazine, 26. Electrode for high frequency fat electric heating

Claims (1)

[Scope of Claims] 0) A heating cylinder that heats and melts a lumpy solid piece of molding material that is fitted with a heater on its outer peripheral surface and inserted inside, a nozzle attached to the front surface of the cylinder, and a heating cylinder that is heated and melted through the nozzle. An injection molding machine equipped with an injection granger that injects heated and molten molding material into a mold. (2) The heating cylinder is a glass tube.
B Injection molding machine as described in scope of description (1). (3) The injection molding machine according to claim (1), wherein the heater is an infrared lamp or a high frequency electrically shielded heating electrode.