JPS6410326B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection molding machine for manufacturing resin products.

Conventionally, in order to increase the melt-kneading effect of the screw in an injection molding machine, it has been necessary to increase L/D, for example, from 15 to 16, where L is the effective length of the screw and D is the screw diameter. Therefore, the feed rate of pellets per revolution of the screw was poor, the number of revolutions of the screw was large in order to supply the required amount of pellets, and the number of revolutions was not constant. In addition, due to the large L/D, the screw became larger, which increased the weight of the screw and injection cylinder, and the heater capacity and molding machine became larger, increasing the weight, price, and running cost of the equipment. Because the rotational efficiency and rotational speed of the screw are unstable, the required material supply time becomes long, and the screw rotational power efficiency is poor and power loss is large. In addition, the amount of heat generated by the rotation of the screw varied, making it difficult to control the temperature of the injected resin, increasing the cost of equipment for temperature control.

This invention dramatically improves the pellet supply rate by providing a plurality of longitudinal elliptical grooves in the pellet supply section of the injection cylinder, and by providing lead grooves at the bottoms of several peaks at the pellet supply inlet of the screw. By increasing the pressing force, reducing the screw rotation speed to supply the required amount of pellets, and preventing the pellets from rotating in the groove, the rotation speed can be stabilized and the heat generated by the screw rotation can be stabilized. It is possible to stabilize the temperature of the injected resin and reduce the cost of equipment for controlling the temperature of the injected resin, and by increasing the effect of screw rotation power, the cycle of the molding machine can be shortened and energy can be saved. By shortening L/D, the heater capacity can be reduced, and the aim is to create a compact, inexpensive, and energy-saving injection molding machine.

Hereinafter, the configuration of an embodiment of the present invention will be described with reference to the drawings.

An injection nozzle 11 and a heating heater 10 are fixed to the injection cylinder 9, and the injection cylinder 9 is fastened and fixed to the pellet supply block 7. This pellet supply block 7 is connected to the slide table 1.
5, the nozzle touch cylinder 2
and the connecting rod 13 to slide along the sliding guide 16. This sliding guide 16 is fixed to the main body 17 with bolts. The screw 8 is held in a bearing case 4, rotated by a hydraulic motor 3, and moved up and down within an injection cylinder 9 by a hydraulic cylinder 1. The bearing case 4 is bolted to the sliding table 14, and the hydraulic cylinder 1
The sliding guide 16 is slid by. Hydraulic cylinder 1 is connected to pellet supply block 7 by tie bar 5.
Fixed. The hopper 6 is fixed to a pellet supply block 7, and pellets are supplied by the screw 8 through a pellet input port 19 of the injection cylinder 9 and a plurality of oval pellet feeding grooves 18 provided in the direction of the cylinder. The mold section 12 is opened and closed by a cylinder (not shown). Upon activation, the mold 12 is clamped, the nozzle 11 is pressed against the mold 12 by the nozzle touch cylinder 2, the resin measured in the injection cylinder 9 is pushed down by the hydraulic cylinder 1, and the resin is poured from the nozzle 11 into the mold 12. eject it. The screw 8 is rotated by the hydraulic motor 3 at certain timing, and the pellets in the hopper 6 are fed through the pellet input port 19 and the elliptical pellet-eating groove 18 into the screw 8.
and the nozzle tip 1 supplied by the lead groove 22
It is weighed to 1. During this weighing, to prevent the rotation of the screw 8 and the pellets inside the screw, the pellets are caught by the elliptical pellet-biting groove 18, and the screw groove 22 is used to ensure that the pellets are fed in the direction of the nozzle 11. At the same time, the kneading effect of the material is enhanced by the rounded portions 21 provided at the tips of the screw crests 23 that protrude in the normal direction of the screw surface at a plurality of pitch intervals of the screw grooves 22. On the other hand, the screw 8 pushes back the hydraulic cylinder 1 upward while measuring, completing the measurement.Next, the nozzle touch cylinder 2 rises, releases the nozzle 11 from the mold 12, opens the mold 12 at the rising end, and releases the product (not shown). The ejection is completed using the ejector rod.

As an effect of this invention, the plurality of elliptical pellet-biting grooves provided in the pellet supply section of the injection cylinder in the direction of the cylinder prevent the pellets from being caught and rotated, and the pellets are kneaded in the direction of rotation shown in the arrow in Fig. 5. While stirring, the screw lead groove reliably increases the pushing pressure in the nozzle direction, and furthermore, the rounded tip of the screw crest protruding in the normal direction of the screw surface allows kneading in the rotational direction indicated by the arrow in FIG. 3. That is, by kneading in the rotational direction by the elliptical pellet biting groove and kneading in the normal direction by the screw crest, the pellets are kneaded in the vertical and horizontal directions and are pushed out toward the nozzle, so the kneading effect and material supply rate are excellent. In good condition. Therefore, the number of revolutions of the screw for supplying material can be kept low and stable, the equipment cost required for controlling the temperature of the injection cylinder due to the heat generated by the screw can be reduced, the loss of screw rotational power can be reduced, and the L/D can be reduced. Since it can be made as small as 12 to 13, the weight of the injection cylinder and the capacity of the heating heater can be reduced, and the shape of the equipment can also be downsized, making it possible to create a compact, lightweight, and energy-saving injection molding machine.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a part of the injection molding machine according to the present invention cut away, Fig. 2 is an enlarged elevational view of the pellet supply section of the screw, Fig. 3 is an enlarged sectional view of the screw part, The figure is a vertical sectional elevational view taken along the line of FIG. 5 of the pellet supply section, and FIG. 5 is a cross-sectional plan view thereof. In the drawings, reference numeral 9 is an injection cylinder, 7 is a pellet supply block, 18 is a pellet feeding groove, 8 is a screw, 22 is a lead groove, and 21 is a radius groove.

Claims (1)

[Claims] 1. A plurality of elliptical pellet feeding grooves are formed along the direction of the cylinder in the pellet supply block of the injection cylinder, a screw is rotatably fitted in the injection cylinder, and the screws corresponding to the elliptical pellet feeding grooves are A plurality of lead grooves are formed in the trough of the pellet supply section, and a rounded corner portion is formed at the tip of the screw ridge protruding in the normal direction of the screw surface at a plurality of pitch intervals of the screw groove. injection molding machine.