JP3475136B2 - Material preheating device for metal injection molding machine - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a metal injection molding machine,
Material of metal injection molding machine especially suitable for injection molding of light metal materials
Material preheating device .

[0002]

2. Description of the Related Art FIG. 2 is a simplified view showing a material preheating apparatus for a conventional metal injection molding machine. The metal injection molding machine shown in FIG. 2 is a metal injection molding machine for injection molding the light metal material 2 in a molten state (including a semi-molten state), and is rotatably inserted in a heating cylinder 7 having a heating device 4. The screw 1 is rotationally driven by a rotational drive source (not shown).

Light metal material 2 stored in the material tank 20
Is sucked by the hopper loader 23, and the feeder screw 14 in the feeder 6 discharges 1
The amount of the light metal material 2 required for the shot is gradually supplied to the heating cylinder 7. The heating cylinder 7 is provided with a material inlet 3 into which the light metal material is fed from the feeder 6.

In the heating cylinder 7, the light metal material 2 which is being kneaded by the screw 1 while being heated by the heating device 4 is gradually stored in the end portion of the heating cylinder 7 in a molten state (usually a semi-molten state), and a predetermined amount. Is discharged by moving the screw 1 forward after weighing.
In such a conventional metal injection molding machine, the light metal material 2 must be preheated before being put into the heating cylinder 7 for the following reason.

1) When the light metal material 2 with water, oil, etc. still attached is charged from the material charging port 3, these are heated and gasified in the heating cylinder 7, and bubbles are formed in the molten metal (in the semi-molten metal). As a result, it becomes a cause of defective molding such as defective appearance due to cavities and gas burning. 2) In the heating cylinder 7, the light metal material 2 receives heat from the heating device 4, is melted, and is measured in front of the heating cylinder 7 by the rotation of the screw 1. However, when the molding cycle is short, the heat from the heating device 4 is used. Can not receive enough. That is, the light metal material 2 which has not been melted due to lack of melting ability advances while being measured in front of the heating cylinder 7,
The problem arises that the screw 1 becomes unrotatable by the unmelted light metal material 2.

In order to prevent the above-mentioned problems, as shown in FIG. 2, the material tank 20 is preheated by the heater 24 before the light metal material 2 is charged into the heating cylinder 7 to preheat the light metal material 2. Methods such as evaporating and removing water and oil, and compensating for the insufficient dissolution capacity due to the preheating effect have been proposed.

As a result, the preheated light metal material 2 after evaporation of water, oil, etc. is sucked by the hopper loader 23. As a result, when the light metal material 2 sent from the hopper loader 23 into the heating cylinder 7 by the feeder 6 is in a molten state, it is preheated in advance, so that the insufficient melting capacity can be compensated for and the adhesion of water, oil, etc. Since the gas is also removed, the gas generated by the deposit in the aging cylinder 7 also disappears.

As described above, by heating the material tank 20 by the heater 24, it is possible to compensate for the insufficient melting capacity and to evaporate and remove the deposits from the light metal material 2 in advance.

[0009]

However, the conventional material preheating method and apparatus have the following problems. 1) Light metal material that has been preheated to compensate for the lack of melting capacity 2
Is sent to the feeder 6 by the hopper loader 23, but when passing through the hopper loader 23 and the feeder 6, the temperature of the light metal material 2 that has been preheated is reduced, and the preheating effect for compensating for the insufficient melting capacity is also reduced.

2) The material tank 20 is not intended for preheating, but the stock of the light metal material 2 is the first purpose. Therefore, a large amount of the light metal material 2 is stored. Therefore, in order to remove a large amount of deposits such as water and oil of the light metal material 2 at a predetermined temperature, the deposits cannot be removed without heating for a long time.

3) When the capacity of the heater 24 is increased to raise the temperature in a short time in order to solve the problem of the above 2), the light metal materials 2 are welded to each other inside the wall surface of the material tank 20 near the heating heater 24. Will end up.

4) Since the hopper loader 23 and the feeder 6 have neither a temperature raising device nor a temperature control device, temperature unevenness of the light metal material 2 entering the heating cylinder 7 occurs.

Therefore, according to the present invention, the deposits such as water and oil can be removed in a short time without reducing the preheating effect, the metal materials are not welded to each other, and the temperature unevenness is further prevented. Spare material for metal injection molding machine
The purpose is to provide a heating device .

[0014]

In order to solve the above-mentioned problems, the present invention provides a heating cylinder (7) for rotating a metallic material heated by a heating cylinder (7) and changing into a molten state by rotating a screw (1). (7) A metal injection molding machine designed to measure the tip of a metal material for storing a metal material.
Between the upper part (11, 12) and the heating cylinder (7),
In a material preheating device of a metal injection molding machine equipped with a feeder (6) having a feeder screw (14) , the metal material (2) is preheated before being put into the heating cylinder (7) .
The preheating means (21) and the preheating means (21)
The heated metal material (2) is kept warm and supplied to the feeder (6).
A heat-retaining heater (16) for supplying
Partition fence (1 that separates the feeder (6) and the hopper (12)
5), reverse rotation and partition of feeder screw (14)
Circulate the metal material (2) by the action of the fence (15).
According to the above, the temperature unevenness of the metal material (2) is eliminated .

The present invention also provides a metal coating according to claim 1.
In the material preheating device of the molding machine, the hopper (1
1, 12) to the upper hopper (11) and the lower hopper (12)
And an upper hopper (11) and a lower hopper (1
A cylinder (17) is provided between the two and the cylinder (17)
Attach the preheating means (21) to the preheating chamber (5)
Configured and connected to the material inlet (3) of the heating cylinder (7)
Feeder (6), upper hopper (11) and lower hopper
Characterized by having a united structure with the lid (12)
Is.

Further, according to the present invention , the metal material which is heated by the heating cylinder (7) and changes into a molten state is measured at the tip of the heating cylinder (7) by the rotation of the screw (1). Of a metal injection molding machine having a feeder (6) having a feeder screw (14) between a hopper (11, 12) for storing a metal material and a heating cylinder (7). In the preheating device, a preheating means (21) for preheating the metal material (2) before charging it into the heating cylinder (7) and a metal material (2) heated by the preheating means (21) are kept warm. And a heat-retaining heater (16) for supplying the feeder (6) to the upper hopper (11).
It is composed of a lower hopper (12) and an upper hopper (1
Provide a cylinder (17) between 1) and the lower hopper (12)
Together with the cylinder (17), the preheating means (21) is attached.
Of the heating cylinder (7) that constitutes the preheating chamber (5)
The feeder (6) connected to the charging slot (3) and the upper hook
It is characterized in that the pa (11) and the lower hopper (12) have a united structure .

The present invention also provides the features of claims 1 to 3.
In the material preheating device of the metal injection molding machine according to any one of
The preheating means (21) is an induction heating coil.
It is characterized by being configured.

The present invention also provides the features of claims 1 to 4.
In the material preheating device of the metal injection molding machine according to any one of
The metal material preheated by the preheating means
Stirring means for preventing welding due to retention
(18, 19) is characterized in that example Bei a.

The present invention also provides a heating cylinder (7).
The metallic material that is heated and changes to the molten state
The tip of the heating cylinder (7) due to the rotation of the cru (1)
A metal injection molding machine designed to measure
Hoppers (11, 12) for storing materials and heating cylinders
Fee with feeder screw (14) between (7)
For material preheating device of metal injection molding machine equipped with da (6)
Then, the metal material (2) is put into the heating cylinder (7).
Preheating means (21) for preheating before heating, and preheating
The metal material (2) heated by the means (21) is kept warm to
A heat-retaining heater (16) for supplying the feeder (6)
It is provided and preheated by the preheating means (21).
To prevent the deposited metal material from welding due to retention.
Characterized by having a stirring means (18, 19) for
It is a thing.

Further, the present invention is based on claim 2 or claim 3.
In material preheater of metal injection molding machine described in the pre
Material preheating chamber (5) and material provided with heating means (21)
Upper hopper (1) for supplying a metal material to the material preheating chamber (5)
In 1), to store the metal material at a predetermined level
It is characterized in that example Bei level detector (8).

Further , the present invention provides any one of claims 1 to 7.
In the material preheating device of the metal injection molding machine according to any one of
In addition, the temperature for detecting the temperature of the metal material (2)
Temperature detected by detector (13) and temperature detector (13)
Heating control for heating the metal material (2) based on
It is characterized by comprising a device (9).

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG. FIG. 1 is a diagram showing a material preheating apparatus for a metal injection molding machine according to the present invention, and those denoted by the same reference numerals as those in FIG. 2 are the same as or equivalent to those shown in FIG. In the metal injection molding machine shown in FIG. 1, a screw 1 is housed in a heating cylinder 7 equipped with a heating device 4 so as to be rotatable and movable back and forth. On the other hand, the material preheating device 22 is installed above the feeder 6 attached to the material input port 3 of the heating cylinder 7.

The material preheating device 22 is provided between the upper hopper 11 on which the hopper loader 23 is provided, the lower hopper 12 connected to the upper side of the feeder 6, and the upper hopper 11 and the lower hopper 12. A cylinder 17 is provided, and this cylinder 17 forms the material preheating chamber 5. The feeder 6 includes a feeder screw 14 that is rotated by a feeder motor 10, and the feeder rod of the feeder 6 is a material feeding rod 3.
And the inlet of the feeder 6 is connected below the material preheating chamber 5. The material preheating device 22 further includes an induction heating coil 21 and a temperature detector 13 mounted on the outer circumference of the material preheating chamber 5 formed by the cylinder 17. The cylinder 17 is made of a non-magnetic material.

The temperature control of the light metal material 2 located in the material preheating chamber 5 is controlled by the temperature set by the heating control device 9 and the detection value of the temperature detector 13. That is, the temperature detector 13 installed in the cylinder 17 compares the actually measured temperature detected with the temperature set by the heating control device 9, and when the temperature is below the set temperature, the induction heating coil 21 is heated to preheat the material. The light metal material 2 in the chamber 5 is heated.

A hopper loader 23 is installed in the upper hopper 11 above the material preheating chamber 5 of the material preheating device 22,
The light metal material 2 in the material tank 20 is transferred into the upper hopper 11, passes from the upper hopper 11 through the material preheating chamber 5 composed of the cylinder 17, and is dropped into the lower hopper 12 for storage. The upper hopper 11 is provided with a level detector 8 which is a detector for maintaining the light metal material 2 stored in the upper hopper 11 at a constant level.

In the above configuration, the light metal material 2 may be heated by the induction heating coil 21 and partially heated to a high temperature, and the partially heated chip-shaped light metal material 2 is softened and the light metal material is lightened. There is a risk that the two will be welded together. When the light metal materials 2 are welded to each other, there arises a problem that the feeder screw 14 cannot be transferred first even if the feeder screw 14 rotates forward.

In order to prevent this problem, the material preheating chamber 5
The stirring blade 18 is installed in the cylinder 17 of the
At 9, the stirring blade 18 is constantly rotated to stir the light metal material 2. This prevents softening and welding due to heating. In addition, the temperature of the light metal material 2 can be made uniform by stirring.

Further, to the lower hopper 12, the material preheating chamber 5
Although the light metal material 2 heated by is dropped, the temperature may decrease while being stored in the lower hopper 12. In order to prevent this temperature decrease, a heat retention heater 16 is installed on the inner wall surface of the lower hopper 12. Insulation heater 1
The capacity of 6 is for maintaining the temperature of the light metal material 2 heated in the material preheating chamber 5, and is set to a capacity of compensating for the loss heat amount of heat radiation.

Next, as a means for maintaining a uniform temperature and preventing welding of the light metal materials 2 that occur when the light metal materials 2 are overlapped with each other, the feeder screw 14 supplies the light metal material to the heating cylinder 7 at each weighing step. Rotate forward to feed 2, but reverse except during the weighing process.

By rotating in the reverse direction, the light metal material 2 stored in the lower hopper 12 gets over the partition fence 15 installed in the central portion of the lower hopper 12, and the light metal material 2 is left and right on the partition fence 15. It is stirred while circulating. In addition to stirring, the light metal material 2 circulates while being kept warm by the heat-retaining heater 16, so that there is no temperature unevenness and it is possible to prevent problems such as welding.

In the embodiments described in detail above, the following constitution is adopted as a means for solving the temperature drop of the light metal material 2. First, above the feeder 6 attached to the material input port 3 of the heating cylinder 7,
The material preheating chamber 5 including the upper hopper 11, the lower hopper 12, and the cylinder 17 is formed in a united structure, and the temperature of the light metal material 2 is controlled by the material preheating device 22.

In addition, when the molding cycle is short, it is necessary to preheat the large-capacity light metal material 2 in a short time. Therefore, in the material preheating chamber 5 consisting of the cylinder 17 between the upper hopper 11 and the lower hopper 12, The induction heating coil 21 is mounted, and the cylinder 17 is made of a non-magnetic material. Further, the induction heating coil 21 is controlled by installing a temperature detector 13 at the outlet of the material preheating chamber 5 composed of the cylinder 17, and comparing the temperature set by the heating controller 9 with the temperature detected by the temperature detector 13. Then, the induction heating coil 21 is controlled.

Further, the feeder screw 14 attached to the material charging port 3 of the heating cylinder 7 rotates simultaneously with the timing of rotation of the screw 1 inserted in the heating cylinder 7, and the lower hopper 12 causes the heating cylinder 7 to move. When the screw 1 in the heating cylinder 7 is stopped, the feeder screw 14 is rotated in the reverse direction so that the left and right space chambers of the partition fence 15 provided in the center of the lower hopper 12 are made of a light metal material. 2 is circulated while passing over the partition fence 15, whereby the light metal material 2 does not stay in one place, so that a uniform temperature can be maintained and
The light metal materials 2 are prevented from being welded to each other when they are overlapped with each other.

Further, the material preheating chamber 5 consisting of the cylinder 17 is provided with a stirring blade 18 from the upper side and is constantly rotated by a stirring motor 19 to prevent the material from staying and becoming overheated. Further, in order to keep the temperature of the light metal material 2 before being put into the heating cylinder 7 at a constant value, a heat insulating heater 16 is provided inside the lower hopper 12 to eliminate the temperature drop and the temperature unevenness of the light metal material 2.

Further, a level detector 8 is installed in the upper hopper 11 in order to always store a constant amount of the light metal material 2 in the material preheating chamber 5 and the upper hopper 11.
When the light metal material 2 in the inside decreases, the light metal material 2 is supplied from the material tank 20 by the hopper loader 23.

[0044]

As is apparent from the above description, according to the present invention, deposits such as water and oil can be removed in a short time without reducing the preheating effect, and metal materials are welded to each other. it is also not an effect that it is the this <br/> to provide materials preheater of metal injection molding machine capable of preventing further temperature variations.

[Brief description of drawings]

FIG. 1 is a schematic view showing a material preheating device of a metal injection molding machine according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a material preheating device of a conventional metal injection molding machine.

[Sign clearing]

1 screw 2 Light metal materials (metal materials) 3 Material input port 4 heating device 5 Material preheating room 6 feeder 7 heating cylinder 8 level detector 9 Heating control device 10 feeder motor 11 Upper hopper 12 Lower hopper 13 Temperature detector 14 Feeder screw 15 partition fence 16 Heat insulation heater 17 cylinder 18 stirring blades 19 stirring motor 20 material tank 21 induction heating coil 22 Material preheating device 23 Hopper loader 24 heating heater

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-51827 (JP, A) JP-A-8-257735 (JP, A) Actually open 1-171621 (JP, U) Special table 2002-511800 (JP, A) International Publication 99/016565 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) B22D 17/00 B22D 17/30 B22D 17/32

Claims (8)

(57) [Claims] 1. Metal injection molding in which a metal material heated by a heating cylinder (7) and changing into a molten state is metered to the tip of the heating cylinder (7) by rotation of a screw (1). Machine for storing metal materials
Between the upper part (11, 12) and the heating cylinder (7),
With a feeder (6) having a feeder screw (14)
In a material preheating device for a metal injection molding machine, a preheating means (21) for preheating the metal material (2) before charging it into the heating cylinder (7 ) and a preheating means (2).
The metal material (2) heated in 1) is kept warm and the feeder
A heat insulation heater (16) for supplying to (6)
Along with it, a partition fence that separates the feeder (6) and the hopper (12)
(15) equipped with a reverse rotation of the feeder screw (14)
Circulate the metal material (2) by the action of the partition fence (15)
By doing so, the temperature unevenness of the metal material (2) is eliminated.
Material preheater of metal injection molding machine, characterized in that as that. 2. The material preheating device for a metal injection molding machine according to claim 1, wherein the hopper parts (11, 12) are connected to the upper hopper (11) and the lower hopper.
The upper hopper (11) and the lower hopper (12).
A cylinder (17) is provided between the side hoppers (12) and
The cylinder (17) is equipped with a preheating means (21) to preliminarily add heat.
Material input port of the heating cylinder (7) that constitutes the heat chamber (5)
Feeder (6) and upper hopper (1) connected to (3)
A material preheating apparatus for a metal injection molding machine, characterized in that 1) and the lower hopper (12) have a united structure . 3. A heating cylinder (7) heats and melts
The metal material that changes to the molten state
By rotating, weigh the tip of the heating cylinder (7).
A metal injection molding machine that stores metal materials.
Between the upper part (11, 12) and the heating cylinder (7),
In a material preheating device of a metal injection molding machine equipped with a feeder (6) having a feeder screw (14) , the metal material (2) is preliminarily fed into the heating cylinder (7).
Preheating means (21) for preheating and preheating means (2
The metal material (2) heated in 1) is kept warm and the feeder
A warming heater (16) for supplying the hopper (11, 12) to the upper hopper (11) and the lower hopper.
The upper hopper (11) and the lower hopper (12).
A cylinder (17) is provided between the side hoppers (12) and
The cylinder (17) is equipped with a preheating means (21) to preliminarily add heat.
Material input port of the heating cylinder (7) that constitutes the heat chamber (5)
Feeder (6) and upper hopper (1) connected to (3)
1) and the lower hopper (12) have a combined structure
Characterizing material preheating device for metal injection molding machine. 4. The material preheating device for a metal injection molding machine according to claim 1, wherein the preheating means (21) is composed of an induction heating coil.
Material preheater of metal injection molding machine, characterized in that that. 5. The material preheater metal injection molding machine according to any one of claims 1 to 4, the metallic material is preheated residence by preheating means
Stirring means (18, 1)
9) A material preheating device for a metal injection molding machine, characterized by comprising: 6. A heating cylinder (7) heats and melts.
The metal material that changes to the molten state
By rotating, weigh the tip of the heating cylinder (7).
A metal injection molding machine that stores metal materials.
Between the upper part (11, 12) and the heating cylinder (7),
In a material preheating device of a metal injection molding machine equipped with a feeder (6) having a feeder screw (14) , the metal material (2) is preliminarily fed into the heating cylinder (7).
Preheating means (21) for preheating and preheating means (2
The metal material (2) heated in 1) is kept warm and the feeder
A heat insulation heater (16) for supplying to (6)
In addition, the material preheating apparatus for a metal injection molding machine is provided with stirring means (18, 19) for preventing the metal material preheated by the preheating means (21) from being welded due to retention. . 7. The material preheating apparatus for a metal injection molding machine according to claim 2 or 3 , wherein the material preheating chamber (5) provided with preheating means (21) and the metal in the material preheating chamber (5). Upper hopper for feeding material (1
1) A material preheating apparatus for a metal injection molding machine, comprising a level detector (8) for storing a metal material at a predetermined level. In material preheater of metal injection molding machine according to any one of claims 8] claims 1 to 7, further temperature detector for detecting the temperature of the metal material (2) and (13), the temperature A material preheating device for a metal injection molding machine, comprising a heating control device (9) for controlling heating of a metal material (2) based on a temperature detected by a detector (13).