JP3176121B2 - Metal injection molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus, for example, in a screw-type injection molding apparatus, which avoids adverse effects during high-pressure injection.

[0002]

2. Description of the Related Art Conventionally, there has been known a screw-type injection molding apparatus which forms a semi-solid slurry from an ingot-like metal material and injects the slurry into a mold to form the slurry. For example, Japanese Patent Application Laid-Open No.
No. 258452 has been proposed as such an apparatus, in which an ingot-shaped metal material supplied to a material supply means is heated to a semi-molten state, and the semi-molten ingot is pulverized by a pulverizer to form an injection machine. The screw is fed to the screw base end side in the heating cylinder, and a semi-solid slurry is formed by the rotational stirring action of the screw in the heating cylinder. When the amount of the semi-solidified slurry formed by the rotational stirring of the screw and sent forward reaches a predetermined amount, the screw is extruded at a high speed and injected into a mold.

[0003]

However, in the case of the above-mentioned apparatus, since the same screw is used for both kneading and injection of the material, there is a problem that an excessive load is applied inside the molding machine. In other words, although the metal material on the screw tip side has a semi-solid slurry, the metal material on the screw base end side is not kneaded immediately after being pulverized, and the screw is extruded at high speed in such a state. For this reason, the heating cylinder and the screw at a location where kneading is insufficient are adversely affected. In addition, since kneading and injection are performed by one screw, the mass of the screw increases, and it is necessary to move and stop the screw at a higher speed.

[0004]

According to the present invention, there is provided a mold and a product of the mold .
In a metal injection molding apparatus provided with an injection machine for injecting a molding material into a shape part and material supply means for supplying a metal material to the injection machine, the injection machine has a sealing structure on a product shape part of the mold.
Plunger injection machine communicating with the plunger and the plunger
Horizontal mixing screw injection that communicates with the injection machine in a sealed structure
It consists of a extruder, allowed communicates lateral kneading screw injection machine to said material supply means, Sula kneading screw injection machine
Inject semi-solid metal slurry from plunger through plunger
Machine to be supplied in the plunger sleeve of the machine.
And features. In claim 2, in claim 1,
Stop the slurry supply port of the slurry kneading screw injection machine
After closing with the valve, the plunger of the plunger injection machine
Inject semi-solid metal slurry into the product shape of the mold with the tip
It is characterized by having been constituted so that.

[0005]

[Function] The metal material is mainly kneaded by the horizontal kneading screw injection machine, and the injection into the mold is performed by the vertical plunger injection machine. Moreover, each load can be distributed. Also, since the kneading and injection conditions can be set independently by setting them separately,
It is easy to hold and a high quality metal molded body can be formed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a metal injection molding apparatus according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is an overall view of an injection molding apparatus of the present invention, and FIG. 2 is a partially enlarged view.

First, the general outline of the injection molding apparatus will be described with reference to FIG.

The injection molding machine of the present invention includes a mold 2 connected to one end of the injection machine 1 and a material supply chamber 3 connected to the other end of the injection machine 1 as material supply means. The metal material W in the form of an ingot supplied from 3 is processed to form a semi-solid slurry, and is injected into the mold 2.

The injection machine 1 is a horizontal kneading screw injection machine 1a provided on a support 4 as shown in FIG.
And a product shape part provided in the mold 2 adjacent to the mold 2
47 and consists of vertical plunger injection machine 1b communicating, both 1a, 1b is the product shape portion 4 of the mold 2 in a sealed structure
It communicates with 7 .

The kneading screw injector 1a includes a heating cylinder 6 supported by a cylinder holder 5, and a kneading screw 7 provided in the heating cylinder 6. An induction heater 16 is provided around the heating cylinder 6. A heat insulating material 17 is provided, and an attachment 19 which is surrounded by a ceramic or heat-resistant alloy attachment 18 is provided on the tip side thereof, and the slurry supply port 2 having a tapered tip is provided.
0 is formed. The slurry supply port 20 opens into a plunger sleeve 10 of a plunger injection machine 1b described later. The heating cylinder 6 is provided with a plurality of thermocouples for temperature control.

A stop valve 23 is provided at the tip of the kneading screw 7. The stop valve 23 has a diameter larger than the minimum diameter portion of the tip of the slurry supply port 20, and when the screw 7 advances, the slurry supply port 20
And a rear end portion thereof is connected to a screw rotation motor 24 so as to be rotatable.

The screw rotating motor 24
Is mounted on the support base 4 via a slide guide 25, and is slidable back and forth (left and right in the figure).

The spiral groove of the kneading screw 7 is provided at least on the front side of the material supply chamber 3, and the material supply chamber 3 communicates with the upper part of the rear end of the spiral groove.

The rear end side of the kneading screw 7 extends further rearward than the screw rotation motor 24 via a coupling and is connected to a screw longitudinal movement cylinder unit 26. For this reason, the kneading screw 7 is operated by the operation of the
The screw rotation motor 24 moves back and forth.

The heating cylinder 6 and the kneading screw 7
The sliding part of the heating cylinder 6 is provided with a sealing part such as a metal packing or a metal seal in an appropriate place to have a sealed structure in which the inside of the heating cylinder 6 is prevented from contacting the outside.

A ceramic plate 28 is provided at the joint between the support table 4 and the cylinder holder 5, and an appropriate place on the support table 4 side and an appropriate place on the rear part of the heating cylinder 6 are cooled by a cooling coil or the like. This is because the cylinder holder 5 is heated more than a normal injection molding machine, so that adverse effects on other devices and the like are avoided.

On the other hand, as shown in FIG. 2, the plunger injection machine 1b includes a plunger sleeve 10 having a ceramic sleeve 11 inside, and a plunger tip 12 slidably movable in the plunger sleeve 10.
Heating heater 13 is provided around plunger sleeve 10.
Covered with.

A heat insulating material 14 is provided around the heater 13 and the plunger sleeve 1 is provided.
A plurality of thermocouples for temperature control are provided at two predetermined locations.
Further, the plunger sleeve 10 does not have a pouring port open to the outside like a so-called cold chamber sleeve, and is a semi-closed sleeve. In addition, in order to keep heat and improve durability, a ceramic sleeve 11 is provided on the inner surface.
, But may be coated with ceramic.

The plunger sleeve 10 is located at the front.
As described above , the plunger tip 12 is configured to slide up and down, and the above-described slurry supply port 20 of the horizontal kneading screw injection machine 1 a is provided at the lower part of the plunger sleeve 10. Side to open and communicate with
The lower part of the jar sleeve 10 is in the product shape part 47 of the mold 2.
It is communicated in a sealed structure.

The end of the plunger sleeve 10 is
It is connected to the. That is, the mold 2 includes a pair of mold supporting frames 41, 42, a fixed mold 43, a movable mold 44, and a shunt 45 held by the mold supporting frames 41, 42, and the plunger sleeve 10 The shunt 45 is connected to a product shape portion 47 between the dies 43 and 44 via a runner 46 provided on the diverter 45. Note that a gate 48 is provided between the runner 46 and the product shape part 47.

Next, the outline of the material supply chamber 3 connected to the kneading screw injector 1a will be described with reference to FIG.

The material supply chamber 3 is divided from above into an ingot introduction chamber 31, a heating chamber 32, a heat insulation chamber 33, and a chop chamber 34, and a first shutter 35 is provided between the introduction chamber 31 and the heating chamber 32. And a second shutter 36 is provided between the heating chamber 32 and the heat retaining chamber 33 so as to be able to shut off. In addition, each room 31, 32, 3
Both the metal seals 3 and 34 have metal seals and metal seals at appropriate locations, and have a sealed structure.

The first and second shutters 35, 3
The opening / closing cylinder units 37 and 38 can move forward and backward horizontally so as to open and close in a direction perpendicular to a material supply path formed in a vertical direction.

The introduction chamber 31 is a chamber for supplying the ingot W. The introduction chamber 31 is configured so that the temperature inside the chamber can be kept constant by a heater provided therearound, and has an ingot holder which can be lowered toward the heating chamber 32. I have.

The heating chamber 32 is a chamber for heating the ingot W, and has a ceramic sleeve on which a heating coil is wound on a second shutter 36 on which the ingot W is placed.

An inert atmosphere conversion mechanism 50 is connected to the heating chamber 32 and the introduction chamber 31. The inert atmosphere conversion mechanism 50 includes a vacuum pump 51 for evacuating the air in the room and a gas cylinder 52 for supplying an inert gas such as argon, nitrogen, carbon dioxide or the like into the room. It is provided to maintain good quality.

The heat insulation room 33 is a room for preventing the temperature from dropping until the heated ingot W is chopped. The heat insulation room 33 is kept at a predetermined temperature by a heater, and the height of the room is kept at another level. The chamber is longer than the chamber, and is also considered to serve as a temporary stock room for the material or a chamber for regulating the supply amount.

The lower chop chamber 34 is a chamber for cutting and crushing the ingot W having reduced deformation resistance and supplying it to the kneading screw 7 in the lower heating cylinder 6. Is provided with a kneader-type biaxial chopper 53.

The two-axis chopper 53 has a pair of rotating bodies having spiral blades facing in opposite directions. The rotating bodies are rotated in opposite directions to engage the spiral blades in a non-contact state, and the ingot W is moved downward. It is crushed so as to draw in. The two-axis chopper 53 rotates in synchronization with the kneading screw 7, and when stopped, the ingot W
Also serves as a stopper.

The chop chamber 34 is also heated and held by a heater to prevent the temperature from dropping.
The three-drive hydraulic or electric motor is located far away from the device to avoid adverse effects of heat.

The operation of the above metal injection molding apparatus will be described.

Introducing chamber 3 by inert atmosphere generating mechanism 50
When each chamber or the like is evacuated and inactivated via the heating chamber 1 and the heating chamber 32, an ingot W of, for example, a magnesium alloy is supplied into the introduction chamber 31 and is heated in a range of about 100 ° C. to 300 ° C. . Then, moisture adhering to the surface of the ingot W is removed by evaporation.

Subsequently, the ingot W is sent to the lower heating chamber 32, and for example, the power set in advance by a test,
Depending on the frequency, time, etc., the material is induction-heated until it reaches a semi-solid region above the solidus and below the liquidus.

When the heating is completed, the ingot W is dropped into the lower heat retaining chamber 33 and chopped by the biaxial chopper 53. That is, the heated ingot W
The deformation resistance is reduced to about several hundredths to several thousandths of room temperature, and is torn and crushed and cut by the helical blades of the two rotating bodies rotating in opposite directions.

The cut metal material is supplied to a kneading screw 7 in a heating cylinder 6, and solid dendrites are separated and semi-solidified by the strong stirring action of the screw 7 and the heating from the heating cylinder 6 while being granulated. Slurry is carried forward.

In other words, the metal material in the heating cylinder 6 is slurried toward the front of the kneading screw 7 and is insufficiently kneaded toward the base end. The screw 7 itself is extruded at a high speed and a high pressure when a certain amount of the semi-solidified slurry is accumulated in front of the screw 7.

Therefore, there is a problem in durability such as abrasion and fatigue of the screw 7 and the heating cylinder 6 at the base end portion where kneading is insufficient.

Therefore, in the case of the present invention, the slurry conveyed forward is supplied from the slurry supply port 20 to the plunger sleeve 10.
After that, the screw 7 moves forward and the stop valve 23 closes the slurry supply port 20, and then the injection is performed by the plunger injection machine 1b. Since the plunger sleeve 10 is a semi-closed sleeve that does not come into contact with the outside as described above, oxidation can be effectively prevented until injection.

After the slurry supply port 20 is closed by the stop valve 23, the plunger tip 1
2, a series of operations of the plunger tip 12 and the kneading screw 7 will be described in more detail.

Plunger chip 1 at the stage when injection is completed
Reference numeral 2 denotes a position at which the slurry supply port 20 is closed. Then, while the material in the product shape portion 47 is solidified, the plunger tip 12
Keeps its position, during which the kneading screw 7 rotates for the first time to form a semi-solidified slurry, which is fed back in front of the screw 7, and a predetermined amount of the slurry is stopped by the stop valve 23.
Accumulate on the front of the.

After the solidification of the molded product is completed and the mold is released, when the plunger tip 12 retreats (rises) to open the slurry supply port 20, the kneading screw 7 moves forward to remove the accumulated slurry in a short time. Push in. At the same time, the slurry supply port 20 is closed by the stop valve 23. The injection is performed again by the plunger tip 12. Then, the above operation is repeated.

In order to repeat the above operation, the heating cylinder 6 and the kneading screw 7 are connected to the plunger sleeve 1.
It has a diameter corresponding to the capacity of 0, and the kneading screw 7 is slidable in the axial direction as described above.

Since the kneading screw injector 1a does not have an injection function, no high pressure is applied to the heating cylinder 6, the kneading screw 7, the slurry supply port 20, and the like, and strict performance is not required as a structural material. Further, since there is no need to move and stop the screw 7 having a large mass at a high speed by the rotary motor, it is possible to provide an energy-saving compact device. In addition, since the kneading and injection operations are performed by separate devices, it is extremely easy to set, for example, temperature control and time management during kneading and injection to optimal conditions, respectively, which contributes to improvement in molding quality. What you get.

It should be noted that, with the above-described apparatus, for example, MMC molding or the like, which has been frequently manufactured in recent years, can be performed in-line.

That is, such MMC (metal-based composite material)
There is a method such as component casting in which ceramic particles and the like are put into a semi-solidified slurry and dispersed while stirring. However, a supply port for ceramic powder is provided in a screw 7 or the like directly below the chop chamber 34. This is because the MMC slurry can be easily manufactured in the heating cylinder 6.

Further, MMC in which ceramic particles and the like are dispersed
It is also possible to use ingots. At this time, MM
C ingots have the problem that machining is difficult and processing costs are extremely high when they are processed into pellets. However, if they are in a semi-solid state, the deformation resistance becomes sufficiently smaller than at room temperature, and heating and supply are performed in the same manner as alloy ingots. Because it can be formed, it can be molded without increasing costs.

[0047]

As described above, in the metal injection molding apparatus of the present invention, the injection machine communicates with the product shape portion in the mold in a sealed structure.
It consists of a horizontal kneading screw injection molding machine and a vertical plunger injection machine.The kneading screw injection molding machine mainly performs kneading of a semi-solid metal slurry with a relatively small load, Since the injection of the semi-solid metal slurry into the product shape portion of the mold is performed by the plunger injection machine, each load is dispersed, and the durability of the injection molding apparatus can be improved. In addition, it becomes easy to set the respective conditions of kneading and injection to optimal conditions, and a high quality metal molded body can be formed.

[Brief description of the drawings]

FIG. 1 is an overall view of an injection molding apparatus according to the present invention.

FIG. 2 is a partially enlarged view of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Injection machine 1a Kneading screw injection machine 1b Plunger injection machine 2 Die 3 Material supply means 10 Plunger sleeve 12 Plunger tip 20 Supply port 23 Stop valve 47 Product shape part W Ingot

Continuation of the front page (56) References JP-A-61-89821 (JP, A) JP-A-3-258452 (JP, A) JP-A-1-170565 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) B22D 17/30 B22D 17/00 B22D 17/20 B29C 45/54

Claims (2)

(57) [Claims] 1. A metal injection molding apparatus comprising a mold, an injection machine for injecting a molding material into a product shape portion of the mold, and material supply means for supplying a metal material to the injection machine. Communicates with the product shape part of the mold in a sealed structure
Vertical plunger injection machine and the inside of the plunger injection machine
Consists of a lateral kneading screw injection machine that communicates with a sealed structure, the prior SL lateral kneading screw injection machine allowed communicates with the material supply means, from the slurry supply port kneading screw injection machine
Plunge the semi-solid metal slurry into the plunger injection machine
Configured to supply into the Yasuribu, metal injection molding apparatus according to claim and this. 2. A slurry for the slurry kneading screw injection machine.
After closing the supply port with a stop valve, the plunger
With the plunger tip of the machine, semi-solid
It is configured to inject metal slurry
The metal injection molding apparatus according to claim 1.