JP3794570B2 - Metal injection molding apparatus and molding method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a molding apparatus and a molding method for metals such as magnesium alloy and aluminum alloy including a die casting machine and a metal injection molding machine.
[0002]
[Prior art]
As a conventional metal molding apparatus and molding method, there are a die-cast method shown in FIGS. 6 and 7 and a metal injection molding method shown in FIG.
[0003]
The hot chamber die casting machine shown in FIG. 6 includes a melting furnace 33 for melting a metal ingot, a suction port 41 for introducing the molten metal 38 in the melting furnace 33 into the gooseneck 32 and the sleeve 42, and a nozzle for connecting the gooseneck 32 and the mold 31. 34, a gooseneck 32 and a casting piston 35 for applying an extrusion pressure to the molten metal 38 in the sleeve 42, and a structure for injecting SF6 gas 36 into the melting furnace 33 in order to prevent combustion of the molten metal 38 in the melting furnace 33. It has become.
[0004]
In the molding method, the metal material ingot is melted in the melting furnace 33 to form a molten metal 38, and the molten metal 38 is introduced into the gooseneck 32 and the sleeve 42 from the suction port 41. After the casting piston 35 arrives at the set stroke, the casting piston 35 descends, and an extrusion pressure is applied to the molten metal 38 in the gooseneck 32 and the sleeve 42. The molten metal 38 passes through the nozzle 34 and flows into the mold 31 and solidifies.
[0005]
Next, the cold chamber die-casting machine shown in FIG. 7 has a melting and holding furnace (not shown) for melting and holding the molten metal 38, a ladle 39 for pumping the molten metal 38 from the melting and holding furnace, and a pouring capable of charging the molten metal 38 from the ladle 39. A sleeve 43 having a mouth 44, a plunger tip 40 capable of moving back and forth in the sleeve 43, and a mold 37 are provided.
[0006]
In the molding method, the molten metal 38 melted and held in the melting and holding furnace is pumped out using a ladle 39 and is poured into the sleeve 43 from the spout 44. Thereafter, the plunger tip 40 is advanced, and the molten metal 38 in the sleeve 43 is extruded into the mold 37 and molded.
[0007]
Further, the metal injection molding machine shown in FIG. 8 includes a material feeder 51 that drops the inserted material chip 50 into a cylinder 48 heated to a set temperature, a screw 49 that moves forward and backward while rotationally driving the cylinder 48, and a cylinder. 48 is provided with a storage portion 53 at the tip, and a nozzle 46 that connects the storage portion 53 and the mold 45. In order to prevent oxidation of the molten metal 54 in the cylinder 48, Ar gas 55 is introduced into the cylinder 48 from below the material feeder 51. It has a structure to be injected.
[0008]
In the molding method, the charged material chip 50 is dropped into the cylinder 48 by the material feeder 51 and then melted while being advanced by the rotation of the screw 49 in the cylinder 48 heated to the set temperature. The molten metal 54 thus melted is moved to the set-up reservoir 53, injected by the forward movement of the screw 49, filled in the mold 45 through the nozzle 46, and molded.
[0009]
[Problems to be solved by the invention]
However, the conventional metal molding apparatus and molding method have the following problems.
That is, in the die-cast method, it is indispensable that both the hot chamber machine and the cold chamber machine have the melting furnace 33 and the holding furnace in order to melt the metal material. For this reason, furnace management and maintenance have a significant impact on product quality and labor must be expended. In addition, it is necessary to secure a place for placing the furnace.
[0010]
Furthermore, SF6 gas 36 must be injected to prevent burning of the metal material in the furnace, but this gas may affect global warming with respect to environmental problems.
[0011]
Further, in the metal injection molding method, in the heating process of the material chip 50, the room temperature material chip 50 must be heated in a short time to near the high temperature setting temperature of 600 ° C., so that a large heating source is required. Moreover, since the conveyance and injection | emission process of the material chip | tip 50 and the molten metal 54 are used together by the screw 49, a component becomes complicated.
The present invention is to solve such problems.
[0012]
[Means for Solving the Problems]
The present invention has been made in order to solve the above-described conventional problems. By supplying a metal material in an amount equivalent to one shot for each shot, a melting furnace and a holding furnace are not required. be carried out by a mixing roller to be equipped with melt accelerator and conveyed to the heating device and heating the device, there is an object of the present invention to provide an injection molding apparatus and a molding method for the simplified metallic components, the melt Alternatively, the metal material (19) in a semi-molten state is injected and filled into the mold cavity by the injection device (6) for injecting and filling the mold through the nozzle (12) by the forward movement of the plunger tip (7). By doing so, a metal molded body is formed.
[0013]
Among the present inventions, the invention described in claim 1 is a heating device (4) having heating means (2, 27) capable of heating the metal material (19) accommodated therein, and is in a molten or semi-molten state. The formed metal material (19) is injected and filled into the mold cavity by the injection device (6) for injecting and filling the mold through the nozzle (12) by the forward movement of the plunger tip (7). In a metal injection molding apparatus for molding a body,
The heating device (4) is equipped with a pair of mixing rollers (3) through which the metal material (19) can pass between each other and can crush and squeeze the metal material (19).
On the outer circumference of each of the pair of mixing rollers (3), two trapezoidal claw portions are arranged in parallel and arranged in a intermittent manner at predetermined intervals, and one side protrudes in the radial direction. It is characterized by that.
[0015]
Among the present inventions, the invention described in claim 2 is the invention described in claim 1 , characterized in that the pair of mixing rollers (3) can individually control the rotational motion and the rotational speed. It is.
[0017]
The invention according to claim 3 of the present invention is provided in a heating device (4) having heating means (2, 27) capable of heating the metal material (19) accommodated therein, and the metal material (19). ) Can be squeezed and squeezed , and the outer periphery of each is intermittently arranged at a predetermined interval, and two trapezoidal claw portions with one side projecting in the radial direction are arranged in parallel. A first step of dropping a metal material (19) onto at least a pair of mixing rollers (3),
While one of the pair of mixing rollers (3) is stopped, the other is rotationally driven to crush the molten metal material (19) accumulated between the mixing rollers (3) , and a plunger tip ( A second step of dropping into the injection device (6) for injection filling into the mold through the nozzle (12) by the forward movement of 7) ;
One of the mixing rollers (3) is rotationally driven while the other is stopped, and the metal material (19) that has been promoted to be melted between the mixing rollers (3) when the second step is completed is crushed , and the plan A third step of dropping into an injection device (6) for injection filling into a mold through a nozzle (12) by a forward movement of the jar tip (7) ;
Both mixing rollers (3) are driven to rotate at the same time, and the metal material (19) in which molten metal accumulated between both mixing rollers (3) is promoted when the third step is completed is squeezed , and the plunger tip (7) advances. a fourth step of dropping the nozzle (12) an injection apparatus for injecting and filling into the mold through (6) by the motion, Ri Tona,
The metal material (19) dropped on the injection device (6) that has been melted or semi-molten in the heating device (4) is moved through the nozzle (12) by the forward movement of the plunger tip (7). It is characterized in that the mold cavity is filled with injection .
In addition, the code | symbol in the said parenthesis shows the corresponding member of embodiment mentioned later.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic view of a metal injection molding apparatus according to an embodiment of the present invention.
[0019]
The metal material supply device 1, the heating device 4, and the injection device 6 are sequentially integrated in the vertical direction, and the metal material supply device 1 has an amount of metal material 19 corresponding to the weight of one shot for each shot. Is dropped onto the heating device 4.
[0020]
The heating device 4 is provided with the heaters 2 and 27 on the outer peripheral portion and the heat insulating plate 5 on the bottom portion, and can be heated to a temperature at which the metal material 19 accommodated in the heating device 4 can be injected into the mold. is there. In addition, a metal material induction cylinder 26, a thermocouple 23, and a mixing roller 3 are provided inside the heating device 4, and the metal material induction cylinder 26 heats the metal material 19 dropped from the metal material supply device 1. It is possible to guide and drop to four desired positions. The thermocouple 23 controls the heater 27 by measuring the temperature of the metal material 19 in the heating device 4. Ar gas inlet 9 is provided in the upper part of heating device 4, from which Ar gas is introduced into heating device 4, and the inside of heating device 4 is placed in an Ar gas atmosphere to burn metal material 19. To prevent.
[0021]
As shown in FIG. 2, the mixing roller 3 is configured by horizontally arranging a pair of mixing rollers 17 and 18 through which a metal material 19 can pass, and on the outer periphery of the mixing rollers 17 and 18. Are provided with four pairs of claw portions 13, 14, 15, 16 protruding in the radial direction at predetermined intervals intermittently in the circumferential direction. The shape of the claw portions 13, 14, 15, 16 is a trapezoidal shape in which the lower right mixing roller 3 side protrudes longer than the upper part in FIGS. 2 to 5, and the left mixing roller 3 side has an upper part from the lower part. It has a trapezoidal shape that protrudes long. Thereby, for example, when the blade surfaces of the claw portions 13 and 14 face each other as in the state of FIG. 2, they are arranged in parallel with a gap of a predetermined interval. Each of the mixing rollers 17 and 18 can be individually controlled for rotational movement and rotational speed by the rotary motor 11, and these controls are rotational position detection sensors that can detect the positions of the mixing rollers 17 and 18 in the rotational direction. 10 is performed by monitoring from time to time. In this embodiment, four sets of claw portions are arranged, but the present invention is not limited to this.
[0022]
The injection device 6 is provided with a heat retaining heater 8 on its outer periphery, and is cooled by the heat retaining heater 8 to prevent the molten metal introduced from the heating device 4 from being cooled. The injection device 6 includes a plunger tip 7, and the plunger tip 7 can inject the molten metal introduced into a mold (not shown) that contacts the nozzle 12.
[0023]
Next, the operation of the present embodiment will be described.
In the first step shown in FIG. 2, the metal material 19 for one shot is fed from the metal material supply device 1 into the heating device 4 through the metal material guide tube 26 shown in FIG. 1, and a pair of mixing rollers 17, 18. Dropped in between. At this time, the metal material 19 is heated and heated by the heaters 2 and 27, and Ar gas is introduced into the heating device 4 from the Ar gas inlet 9 to form an Ar gas atmosphere. Further, the plunger tip 7 moves backward to the set stroke.
[0024]
Next, in the second step shown in FIG. 3, with the mixing roller 17 stopped, the rotary motor 11 is driven to rotate the mixing roller 18 to a desired rotation angle, and it is accumulated in the A chamber 20 in FIG. The metal material 19 is sandwiched between the claw portion 13 and the claw portion 16, and the metal material 19 whose melting is promoted is dropped onto the injection device 6.
[0025]
Next, in the third step shown in FIG. 4, with the mixing roller 18 stopped, the rotary motor 11 is driven to rotate the mixing roller 17 to a desired rotation angle, and when the second step is completed, B in FIG. The metal material 19 in which the molten metal accumulated in the chamber 21 is promoted is crushed by the claw portion 15 and the claw portion 16 and dropped into the injection device 6.
[0026]
Next, in the fourth step shown in FIG. 5, the rotary motor 11 is driven to rotate the mixing rollers 17 and 18 at the same time, and is sandwiched between the claw portion 15 and the claw portion 16 when the third step is completed. In FIG. 4, the metal material 19 in which the molten metal accumulated in the C chamber 22 is promoted is squeezed out and dropped onto the injection device 6.
[0027]
Next, as the fifth step, the rotary motor 11 is driven to rotate the mixing rollers 17 and 18 to the position shown in FIG. 2 where the metal material 19 can be trapped by the both claws 13 and 14. In addition, if it arrange | positions so that the space | interval of each set of the claw parts 13 and 15 on the mixing roller 17 and the space | interval of each set of the claw parts 14 and 16 on the mixing roller 18 may become small, said 5th process will be shortened. Or can be lost.
[0028]
As described above, in the above-described process, the mixing rollers 17 and 18 are monitored and controlled as needed by the rotational position detection sensor 10 and perform individual intermittent operations instead of continuously rotating at a constant speed.
[0029]
The molten metal dropped into the injection device 6 is kept in the same temperature range as the heating device 4 by the heat retaining heater 8, and is injected and filled into the mold through the nozzle 12 by the forward movement of the plunger tip 7, and after cooling and solidification. Then, the mold is opened and the molded product is taken out.
[0030]
A general temperature range of the zones of the heaters 2 and 27 and the heat retaining heater 8 when forming a magnesium alloy or an aluminum alloy is shown below.
Heater 2 zone: 350 ° C to 400 ° C
Heater 27 zone: 570 ° C to 630 ° C
Thermal insulation heater 8 zone: 570 ° C to 630 ° C
[0031]
In the above-described embodiment, the metal material 19 is melted while being plastically deformed by the mixing roller 3. However, the present invention is not limited to this, and a gear having the same function as this instead of the mixing roller 3, You may use a screw, a piston, etc.
[0032]
【The invention's effect】
As described above, the invention according to claim 1 of the present invention is melted in the heating device (4) having the heating means (2, 27) capable of heating the metal material (19) accommodated therein. Alternatively, the metal material (19) in a semi-molten state is injected and filled into the mold cavity by the injection device (6) for injecting and filling the mold through the nozzle (12) by the forward movement of the plunger tip (7). In the metal injection molding apparatus for forming a metal molded body , the metal material (19) can pass between the heating device (4) and the metal material (19) is crushed and squeezed out. A pair of possible mixing rollers (3) is provided, and the outer periphery of each of the pair of mixing rollers (3) is intermittently arranged at predetermined intervals, and one side protrudes in the radial direction. 2 trapezoidal tabs As a result, the metal parts are trapped and accumulated between the claw parts of both mixing rollers, and the temperature rises rapidly to promote melting. At the same time, the gap between the claw portions becomes a flow path for the metal material, and the metal material can be uniformly promoted to be melted and dropped to the injection device by performing crushing and squeezing.
For this reason, since it is not necessary to provide a melting furnace that was required in the die casting method, the management and maintenance of the melting furnace become unnecessary, and it is not necessary to separately secure an arrangement location, and further, a shield gas for preventing molten metal combustion is required. SF6 gas is also unnecessary.
[0033]
In addition, since the heat melting portion and the injection portion of the metal material are different, the shape is simpler than that of the metal injection molding method, the components are simplified, and maintenance is easy.
[0034]
Furthermore, it is possible to supply metal materials with sizes ranging from the size of chips used in metal injection molding machines to a lump of the size of the thumb, and it is possible to manufacture molten metal in either a semi-molten or molten state. is there.
[0036]
The invention of claim 2, wherein in is the invention of claim 1, wherein, by individually controlling the rotational movement and the rotational speed of the pair of mixing rollers, fixing one of the mixing rollers, and the other The mixing roller can be crushed by rotating it at a certain angle, and squeezing can be performed by rotating both mixing rollers.
[0038]
In the present invention, the invention according to claim 3 is provided in a heating device (4) having heating means (2, 27) capable of heating the metal material (19) accommodated therein, and the metal material (19) can be crushed and squeezed out, and each outer periphery has a set of two trapezoidal claw portions that are intermittently arranged at predetermined intervals and one side protrudes in the radial direction. A first step of dropping a metal material (19) on at least a pair of mixing rollers (3) provided side by side; and rotating the other in a state where one of the pair of mixing rollers (3) is stopped, Injection that crushes the metal material (19) promoted to be melted and accumulated between both mixing rollers (3), and injects and fills the mold through the nozzle (12) by the forward movement of the plunger tip (7). Second step of dropping into the device (6) Rotating and driving one of the mixing rollers (3) while the other is stopped, and crushing the metal material (19) promoted to be melted between the mixing rollers (3) when the second step is completed, A third step in which the plunger tip (7) is dropped into the injection device (6) for injection and filling into the mold through the nozzle (12) by the forward movement of the plunger tip (7), and both the mixing rollers (3) are driven to rotate simultaneously. Upon completion of the third step, the metal material (19) that has been promoted to be melted and accumulated between the mixing rollers (3) is squeezed out and moved into the mold through the nozzle (12) by the forward movement of the plunger tip (7). A metal material (19) that is dropped into the injection device (6) that is in a molten or semi-molten state in the heating device (4). The plastic Supplying molten metal into the injection device by squeezing the metal material in which all of the melt reduction is facilitated by that so as to inject and fill the mold cavity through the nozzle (12) by forward movement of the jar chip (7) It can be performed.
[Brief description of the drawings]
FIG. 1 is a schematic view of a metal injection molding apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a state of a mixing roller in a first step.
FIG. 3 is a diagram illustrating a state of a mixing roller in a second step.
FIG. 4 is a diagram illustrating a state of the mixing roller in a third step. FIG. 5 is a diagram illustrating a state of the mixing roller in a fourth step.
FIG. 6 is a schematic view of a hot chamber die casting machine.
FIG. 7 is a schematic view of a cold chamber die casting machine.
FIG. 8 is a schematic view of a metal injection molding machine.
[Explanation of symbols]
2, 27 Heating means 3 Mixing roller 4 Heating device 6 Injection device 13, 14, 15, 16 Claw portion 19 Metal material

Claims (3)

In the heating device (4) having heating means (2, 27) capable of heating the metal material (19) accommodated therein, the molten or semi-molten metal material (19) is moved to the plunger tip (7). In the metal injection molding apparatus for molding the metal molded body by injection filling into the mold cavity by the injection apparatus (6) for injection filling into the mold through the nozzle (12) by the forward movement of
The heating device (4) is equipped with a pair of mixing rollers (3) through which the metal material (19) can pass between each other and can crush and squeeze the metal material (19).
On the outer circumference of each of the pair of mixing rollers (3), two trapezoidal claw portions are arranged in parallel and arranged in a intermittent manner at predetermined intervals, and one side protrudes in the radial direction. An injection molding apparatus for metal, characterized in that   2. The metal injection molding apparatus according to claim 1, wherein the pair of mixing rollers (3) can individually control a rotational motion and a rotational speed. 3. It is equipped in a heating device (4) having heating means (2, 27) capable of heating the metal material (19) accommodated therein, and can be crushed and squeezed on each outer periphery. On at least a pair of mixing rollers (3) , which are intermittently arranged at predetermined intervals, and two trapezoidal claw portions with one side projecting in the radial direction are arranged in parallel. A first step of dropping a metal material (19) on
While one of the pair of mixing rollers (3) is stopped, the other is rotationally driven to crush the molten metal material (19) accumulated between the mixing rollers (3) , and a plunger tip ( A second step of dropping into the injection device (6) for injection filling into the mold through the nozzle (12) by the forward movement of 7) ;
One of the mixing rollers (3) is rotationally driven while the other is stopped, and the metal material (19) that has been promoted to be melted between the mixing rollers (3) when the second step is completed is crushed , and the plan A third step of dropping into an injection device (6) for injection filling into a mold through a nozzle (12) by a forward movement of the jar tip (7) ;
Both mixing rollers (3) are driven to rotate at the same time, and the metal material (19) in which molten metal accumulated between both mixing rollers (3) is promoted when the third step is completed is squeezed , and the plunger tip (7) advances. A fourth step of dropping into an injection device (6) for injection filling into the mold through the nozzle (12) by movement ,
The metal material (19) dropped on the injection device (6) that has been melted or semi-molten in the heating device (4) is moved through the nozzle (12) by the forward movement of the plunger tip (7). A metal injection molding method characterized by injection filling into a mold cavity .

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