JPS602302A - Screw extruding plunger injection molding method and device thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention enables the production of various molded products using materials that harden after being hydrated with water, such as cement, gypsum, and calcium silicate, or ceramic materials, such as clay, various metal oxides, and metal powders. The purpose is to provide a new method and device for molding.

Among the conventional molded products, continuous plates and rods are used.

It is known to produce tubular bodies using conventional two-stage vacuum extruders. However, in the examples of the molded articles shown in FIGS. 1 and 2, the diameter is not constant and curved, and cannot be manufactured by ordinary extrusion molding methods. On the other hand, it is also known to use a Z-stage screw set extruder to inject the molded product into the mold from the nozzle at the tip of the extruder, but the pressure applied by such an extruder is at most an OK level. If the pressure exceeds this limit, the screw will rotate fully, and the raw material cannot be injected. Otherwise, the water ratio of the raw material must be increased, which may cause problems such as shrinkage of the molded product and water breathing. On the other hand, there is also a known method of injecting into a mold using a plunger extruder alone.
It is difficult to feed the material into the plunger cylinder, and the molded product contains many air bubbles because the supplied material contains air during mixing and agitation. Also, the plunger movement is a reciprocating motion, so the molding efficiency is poor.

The present invention eliminates the drawbacks of conventional methods and uses a two-stage screw set extruder in combination with a high-pressure plunger extruder to produce hydraulic inorganic materials with low plasticity and ceramic viscous materials with high precision, high efficiency, and high quality. The present invention relates to a molding method and apparatus that can be produced in

The present invention No. (2) shown in Figs. (3), (4), and (5) below.
The present invention will be explained in detail with reference to a plan view, a side view, and a front view showing an example of an embodiment of the device described in section 2. In the figure, (1) is the tip of the second stage screw of a two-stage screw extruder. The material supplied from the hopper of the extruder is finely granulated in the first stage screw, degassed in the vacuum chamber, and then transferred to the second stage screw. It is extruded and injected through the gate of the tapered constrictor tube (2) into the cylinder (3) which is in kiss touch with the gate. (5) is a rotatable disc to which two cylinders are fixed, and slides and rotates on the side plate (4).

The side plate (4) is held by a stay (6). (8) is a motor for driving rotation m (7), (9) is a clutch brake for starting and stopping the motor, Cl0)
is a speed reducer. The raw material is pushed out by the rear screw to fill the cylinder, but the special device (F) that indicates the end of filling gives a signal to the limit switch (6) and the rear screw stops. Immediately, the rotating disk (5) is rotated 180 degrees by the drive of the motor (8) and touches the gate of the high pressure plunger (AE). In order to accurately locate the stop position, use an air cylinder (Step 4).
By rotating the plate.

It is positioned and locked in the fixing hole (Step 5).

(3) The cylinder 4 is fixed in place and the high pressure source (
A plunger is actuated by high pressure (normally hydraulic pressure), and the raw material in the cylinder (3) is injected and filled into the mold (step 9) through the plunger gate (step 8). (
Step 3) is the plunger sealing case, (20)
is a device that converts the filling of the mold and gives a signal. (2
A signal from 0) causes the plunger to return, while raw material is injected from the screw extruder into another cylinder (3). At the same time as the plunger returns, the rotating plate (
5) is rotated 80 degrees and fixed by kissing each gate of the screw extruder and plunger extruder. Similar operations are repeated.

According to the apparatus of the present invention, during the injection molding operation of the plunger, the other cylinder is filled with the degassed raw material, so that two hours are not wasted. Unlike injection into the complicated and narrow space of a mold for a molded product, filling a cylinder can be done with sufficient extrusion pressure using an ordinary screw extruder, so the water ratio can be increased to improve fluidity. There is no need to increase

On the other hand, the plunger can utilize extremely high pressure such as 00 to 300 Kglo, using any hydraulic or water pressure method, so it is possible to fill every corner of the mold at high speed.

Recently, an improved injection molding machine for plastics has been developed for ceramics on the market, but in this case, after mixing the binder with the sulfur powder, it is granulated and the binder is processed. 200 (1!) is melted and injected, requiring extremely high pressure and weighing 5 kg.
Injection molding of products weighing 10 kg requires extremely high pressure, and the machinery is large and expensive. The original use of the method and apparatus of the present invention is mainly for molding hydraulic compositions such as cement plaster into large weight units of about 0-20 K9, but heavy objects such as these can be used in various casting molds, presses, etc. 7 Since this machine has been used, molding can be performed more quickly than conventional various press cycles (according to the device of the present invention, cycle time is approximately 20 seconds), and molding can be performed by pouring, pressing, etc. Products can be replaced with highly productive and economical equipment. I80° rotation of the inner plate (5) with the mold attached can be designed to take only 4 seconds. Also, compared to the extrusion pressure of about 0 to 300 Kg/cs! Degree I
Because the composition is degassed under a pressure of more than 0 times and filled into the mold, the particles in the molded product are in a close-packed state, resulting in a molded product with high density and high hardness. It has applicability that can be used widely in general industrial fields, including.

It can be said that this molding mechanism combines the advantages of both a conventional extruder and a plunger extruder. Figure 6 shows the injection state of the plunger into one example of the product shown in Figure 7. In this case, the injection is from the side of the body of the product, but the excess material remaining at the gate area is Remove after curing. There is no problem in injecting from the vertical direction using an injection port having the same cross-sectional shape as that shown in FIG. 7, which shows the cross-sectional shape (melting) of the flange portion of the product. (2Ili) in Fig. 2 is inserted for reinforcement, and if a core is used in a W tube, it can be molded so that the front and back surfaces are coated with the composition, so there is no worry of metal rusting. 2. A strong molded body is obtained. Moreover, since all these operations are carried out at room temperature, it is an energy-saving method. If there is a support, the molded composition can be taken out as it is, or after 5. If a thin plate-like tray is pre-caulked and inserted, the molded product is taken out after the tray is removed and cured. The signal indicating the completion of filling of each extrusion injection part and plunger injection part is from the raw material; either the mold part activates a limit switch and gives a signal, or the signal is given by an increase in the amount of material due to filling. There is no problem with the method. Furthermore, as shown in claim 3, the total amount of filling material in the cylinder is filled into the mold at one time.

In the case of a small mold capacity that is not the capacity to be filled, a turntable (24) is installed in front of the plunger gate as shown in the plan view in Fig. There is no problem in placing it in the first place and filling it from the first place to the next. For example, arrange 4 stations on the turntable (24), prepare 4 molds, inject into one of them with a plunger, and then move the mold to the demolding station (25). After taking out the molded product, it is moved to the cleaning station (26) to remove the dust and residual parts, and then moved to (27), where mold release agent, inserts, etc. are inserted, and after 2nd assembly, it is moved again It is filled in front of the plunger gate.

This operation may be temporally synchronized with the operation of the rotating disk. Therefore, without changing the cylinder, it is possible to mold various molds with a capacity smaller than the weight of the cylinder, making it suitable for the production of a wide variety of products. Conversely, if the mold is larger than the cylinder capacity, high-capacity molding is possible by repeating injection from the plunger multiple times.

[Brief explanation of the drawing]

The construction drawing and FIG. 2 are cross-sectional views showing examples of molded products. FIG. 3 is a front view of an example of an embodiment of the device of the present invention;
The figure shows a plan view, and FIG. 5 shows a side view. Fig. 6 is a side sectional view showing the state of plunger injection into the molded product example in Fig. 1, Fig. 7 is a sectional view of a portion of the plunger of the molded product in Fig. 1, and Fig. 8 is the plunger injection gate. FIG. 3 is a plan view showing the turntable at the tip. In the diagram. (1) Tip of extruder rear stage screw (2) Tapered throttle tube (3) Cylinder (4) Side plate (5) Rotating disk (6) Stay (7) Rotating shaft (8) Drive motor (9) Clutch brake (engineering) O) Reducer (II) High-pressure plunger (Part 2) High pressure source (Part 3) Sealing case (Part 4) Air cylinder (I5) Fixed lock hole (Part 6) Limit switch (F) Extrusion filling detection device (Part 4) 8) Plunger gate (work 9) Mold (20) Mold extrusion detector (work 2) Base (22) Remaining part of gate (23) Product flange cross section (24) Mold turntable (25) Demolding Removal station (26) Cleaning station (27) Assembly station (28) Inserted steel pipe (29) Molded product Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) When molding various molded products using hydraulic inorganic compositions such as cement and plaster or ceramic compositions such as clay and metal oxides as raw materials, the first step is to use a two-stage screw vacuum extruder. After degassing the air and other volatile components in the raw material in a vacuum chamber located between the front screw and the rear screw, the raw material is passed through the tapered constriction tube at the end of the extruder to the rear stage. At the screw. After injecting and filling the cylinder with a certain volume, the second step is to immediately separate the cylinder from the extruder and fix it at the injection nozzle at the tip of the injection machine using a separately prepared high-pressure plunger. Screw extrusion plunger molding method in which the raw material in the cylinder is injected into the final molded product mold using a high-pressure plunger. (2) A two-stage screw vacuum extruder and a high-pressure plunger extruder are installed in parallel to the rotating axis of the disk by fixing two cylinders at opposite positions on the peripheral edge of the rotatable disk. Place them in parallel. Of the two opposing cylinders fixed to the disk, one is fixed at the gate position of the screw extruder and the other is fixed at the gate position of the plunger. After injecting the raw material into the cylinder from the screw extruder in the first operation, the central rotating shaft is rotated 800 times to move the injected cylinder to the plunger gate position, and the high-pressure planter is used to push the raw material through the cylinder gate. Inject the raw material into a mold. During this time, the other cylinder is located on the side of the screw extruder gate, and fresh raw material is injected and filled into the cylinder. Screw extrusion plunger injection molding device (3) in which molding is continuously performed at high speed by repeating the above cycle (3) In the device described in claim (2), the cylinder is A screw extrusion plunger injection molding device in which a large number of molds for injection molding from a gate are arranged on a turntable so that the raw material in the cylinder is continuously injected into a large number of molds.