JPH09155527A - Method and device for injection molding of light alloy material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a high-quality large-sized formed product by injecting a molten light alloy material to a cavity from plural nozzles attached to a cylinder head having plural molten metal passages. SOLUTION: A screw 2 is retreated while storing at its tip end a light alloy material which is supplied from a hopper 4 to the screw 2 and which is made into a molten state by the rotary driving. With an injection device advanced by a piston cylinder device 21, plural nozzles 7 are positioned in the nozzle inserting holes of a die 12. Then, a pressure oil stored in an accumulator 17 is supplied to the hydraulic chamber 8 of a hydraulic piston cylinder mechanism 5, driving the screw 2 at high speed, injecting the molten light alloy material to a cavity 16 of a closed die 12, from the plural nozzles 7 through a cylinder head 6 having plural molten metal flow passages 22, through plural spools 13 and runners 15. Consequently, a high-quality large-sized product is easily formed with a satisfactory formability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding method and apparatus for heating and melting a solid light alloy material for injection.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional light alloy material injection molding apparatus has a cylinder barrel a provided with a heater c on the outer periphery thereof, a cylinder head g, and a nozzle h. , A screw b that is rotated and axially driven in the cylinder barrel a, a hydraulic piston / cylinder mechanism f that axially drives the screw b, a hydraulic circuit, and the like.

Therefore, when the screw b is rotationally driven by the hydraulic motor j and the solid light alloy material is supplied from the hopper e to the cylinder barrel a, the light alloy material is kneaded and melted by heat applied from the heater c. , And is sent to the front of the cylinder barrel a and weighed. After measuring a predetermined amount, by switching the solenoid valve r, pressure oil is supplied from the hydraulic pump k and the accumulator q to the hydraulic chamber i of the hydraulic piston / cylinder mechanism f, and the measured light alloy material in a molten state is quickly supplied. It passes through the flow path of the cylinder head g and the nozzle h, and is injected into the mold 1 that has been clamped. The light alloy material injected into the mold 1 passes through the sprue m together with the plug formed at the tip of the nozzle h, and then the plug catcher n
With the plug left in, it is injected into the cavity p through the runner o, and a molded product can be obtained.

[0004]

In the conventional injection molding method, since the light alloy material passes through one nozzle and is injected into the mold, the following problems exist. That is,
Since the light alloy material in the molten state has an extremely fast solidification rate, there is a limit to the flow length in the mold, and there is a problem that a large-sized molded product cannot be obtained. There is also a problem with respect to the quality of the molded product such as the filling property of the light alloy material.

In a general resin injection molding machine,
In order to solve these problems, there is a method of forming a molded product with no sprue or runner by using a hot runner mold with a heating element built into the mold, but in the case of light alloy materials, Since severe temperature control is required, it is unlikely that a hot runner mold can be applied.

In addition, a method of injecting from one injection mold from two injection devices can be considered.
When performing ultra-high-speed injection of 2 seconds, it may be difficult to synchronize the injection control of the two injection devices, and a problem such as poor gate balance may occur.

The present invention has been made in order to solve the above problems of the prior art, and is a method and apparatus for injection molding a light alloy material capable of easily molding a high quality large molded product. Is intended to provide.

[0008]

According to the present invention, in order to inject a predetermined amount of a molten light alloy material into a mold within a predetermined time, it is better to inject from a plurality of nozzles rather than one nozzle. In view of the above, the present invention aims to achieve the above-mentioned object by using a plurality of nozzles. That is, the injection molding method for a light alloy material according to the present invention is a method in which a light alloy material heated and melted in a cylinder barrel is melted from a plurality of nozzles through a cylinder head having a plurality of molten metal channels by a screw. It is characterized by being injected into a mold.

More specifically, a light alloy material in a molten state is injected into one cavity through a plurality of sprues formed in the mold and a runner connected to the sprues, and they are joined together. It is characterized in that a molded product is obtained.

The light alloy material injection molding apparatus according to the present invention is an injection molding apparatus that heats and melts a solid light alloy material and injects the molten light alloy material into a mold. A cylinder head having a plurality of molten metal flow paths is connected to the front part of the cylinder barrel, and a nozzle is attached to each of the molten metal flow paths at the front part of the cylinder head. Is characterized by.

More specifically, a plurality of sprues joined to the nozzles, a runner connected to the sprues, and a cavity into which the runners join are formed in the mold. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on embodiments with reference to the drawings. The injection apparatus according to the present embodiment includes a cylinder barrel 1, a screw 2 provided in the cylinder barrel 1 so as to be axially and rotationally movable, and a hydraulic piston / cylinder mechanism for axially driving the screw 2. 5, a hydraulic circuit that operates the hydraulic piston / cylinder mechanism 5, a hydraulic motor 9 that drives the screw 2 in the rotational direction, and the like. The hydraulic circuit supplies the pressure oil from the hydraulic pump 11 and the accumulator 17 to the hydraulic chamber 8 of the hydraulic piston / cylinder mechanism 5 via the electromagnetic switching valve 18.

The rear end of the screw 2 extends outward from the cylinder barrel 1 and is connected to the piston rod of the hydraulic piston / cylinder mechanism 5.

A cylinder head 6 having a plurality of molten metal passages 22 is connected to the front portion of the cylinder barrel 1, and a front portion of the cylinder head 6 is connected to each of the molten metal passages 22. The nozzle 7 is attached by a leather frog 10. On the outer peripheral portions of the cylinder barrel 1, the cylinder head 6 and the nozzle 7, a heater 3 whose temperature is precisely controlled is provided. Further, a hopper 4 for supplying a light alloy material is provided on the upper rear portion of the cylinder barrel 1.

The above-mentioned injection device is provided on an injection table (not shown) so as to be movable back and forth, and a fixed plate 19 of the mold clamping device is attached to the injection table so as to face the injection device. The die 12 is attached to the fixed platen 19. A drive rod 20 is fixed to the fixed platen 19 on the cylinder barrel 1 side. When the drive rod 20 supplies / discharges pressure oil to / from the piston / cylinder device 21 fixed to the cylinder barrel 1, the cylinder barrel 1, that is, the nozzle 7
Is driven in the direction of touching the mold 12, or in the direction of separating from the mold 12.

The mold 12 is composed of a fixed mold 12a and a movable mold 12b paired with the fixed mold 12a.
The nozzles 7 are provided with the same number of sprues 13 as the inflow ports of the light alloy material in a molten state, and the movable die 12b has a plug formed at the tip of the nozzle 7. A plug catcher 14 for accommodating each of the sprues 13 is provided corresponding to each sprue 13. The sprue 13 is connected to the cavity 16 via a number of runners 15. The cavity 16 is a continuous body, and a molded product is formed from the light alloy material in a molten state injected into the single cavity 16 through a number of runners 15. An injection molding device is constituted by the injection device and the mold clamping device.

Next, a method of injection molding a light alloy material using the above-mentioned injection molding apparatus will be described.

A solid light alloy material has a melting point of 65.
A single metal element having a temperature of 0 ° C. or lower or an alloy based on these metals is used. Practical examples include, for example, aluminum, magnesium, zinc, tin, lead, bismuth, terbium, tellurium, cadmium, thallium, astatine, polonium, selenium, lithium, indium, sodium, potassium, rubidium, cesium, francium, gallium, etc. Among them, simple substances of aluminum, magnesium, lead, zinc, bismuth and tin and alloys based on these metals are particularly preferable. Any of these light alloy materials can be kneaded, melted, and injection-molded by the above-described injection molding device.

The light alloy material having a shape suitable for the injection molding apparatus can be obtained by various methods. For example, the ingot can be obtained by chipping with a chipping machine. Alternatively, cutting powder obtained by cutting with a cutting machine can be used. Alternatively, the molten metal may be dropped into a cooling medium such as water. The light alloy material obtained by these methods has an appropriately small shape, is easy to handle unlike powder, and is easily melted in the process of being fed to the tip portion in the cylinder barrel 1. Further, it can also be obtained by a conventionally known reduction method or rotating consumable electrode method.

The light alloy material prepared as described above is supplied from the hopper 4, the screw 2 is rotationally driven by the hydraulic motor 9, and the screw 2 retracts while the molten light alloy material is stored at the tip of the screw 2. . The injection device is advanced by the piston / cylinder device 21, the plurality of nozzles 7 are aligned with the nozzle insertion holes of the die 12, and touched simultaneously. Next, the pressure oil accumulated in the accumulator 17 is supplied to the hydraulic chamber 8 of the hydraulic piston / cylinder mechanism 5 to drive the screw 2 at high speed, and the light alloy material in a molten state is provided in a cylinder having a plurality of molten metal flow paths 22. A plurality of nozzles 7 pass through the head and eject into one cavity 16 of a mold 12 that is clamped through a plurality of sprues 13 and a runner 15. After cooling and solidifying, the mold 12 is opened and the molded product is taken out. Hereinafter, the same operation is repeated to perform molding.

[0021]

Since the present invention is constructed as described above, the following effects can be obtained. That is, when a molten light alloy material is injected into a mold to obtain a molded article, it is injected into one cavity from a plurality of nozzles attached to a cylinder head having a plurality of molten metal flow paths. As a result, it is possible to easily mold a high quality large molded product.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram showing an injection molding apparatus according to the present invention.

FIG. 2 is a cross-sectional configuration diagram showing a conventional injection molding device.

[Explanation of symbols]

 1 Cylinder Barrel 2 Screw 6 Cylinder Head 7 Nozzle 12 Mold 13 Sprue 15 Runner 16 Cavity 22 Molten Metal Flow Path

Claims (4)

[Claims] 1. An injection molding method for heating, melting and injecting a solid light alloy material, wherein a plurality of light alloy materials heated and melted in a cylinder barrel (1) are melted by a screw (2). Through a cylinder head (6) having a metal flow path (22), a mold (1
A method for injection molding a light alloy material, which comprises injecting into 2). 2. A light alloy material in a molten state is made into a single piece through a plurality of sprues (13) formed in the mold (12) and a runner (15) connected to the sprues (13). The method of injection molding a light alloy material according to claim 1, wherein the molded article is obtained by injecting into the cavity (16) to obtain a joined molded article. 3. A cylinder in which a screw (2) for injecting a light alloy material in a molten state into a mold (12) is inserted in an injection molding apparatus for heating, melting and injecting a solid light alloy material. A cylinder head (6) having a plurality of molten metal flow channels (22) is connected to the front part of the barrel (1),
An injection molding apparatus for a light alloy material, characterized in that a nozzle (7) is attached to each of the molten metal flow paths (22) at a front portion of the cylinder head (6). 4. The mold (12) includes a plurality of sprues (13) joined to the nozzle (7), a runner (15) connected to the sprues (13), and the runner (1).
An injection molding device for light alloy materials according to claim 3, characterized in that one cavity (16) is formed in which the (5) merges.