JPH08257723A - Injection molding device for molded metallic article - Google Patents

Abstract

PURPOSE: To prevent the defective action of an injection machine caused by mix-in of a solid crushed material and to improve the durability by installing a heating means provided around the circumference of a cylinder to the tolerable retreated position of a spiral groove of a screw shaft. CONSTITUTION: Because a material to be formed is heated with a heater 42 installed to the rear end part 52a of a spiral groove 25 at the tolerable retreated position of a screw shaft, the material of the front stock space 53 and from the beginning point of the spiral groove 52 to the rear end part 52a is heated at high temperature and the semi-molten state is kept. Therefore, the temperature of the material to be formed which is kneaded with the screw shaft and accumulated in a stock space 53 is prevented from lowering, solid crushed material is not caused or the inclination of solidification inside the cylinder is eliminated. So, all actions of feeding, kneading, stocking and injecting, etc., are made smoothly and the functionality and the durability can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding apparatus for manufacturing a metal compact.

[0002]

2. Description of the Related Art The present applicant has previously filed Japanese Patent Application Laid-Open No. 5-28562.
In Japanese Patent Laid-Open No. 5 (1994), an "injection molding device for metal molded body" was proposed. According to this technique, the ingot can be continuously made into a semi-solidified slurry to improve the productivity. The outline of this technique will be described with reference to FIG. FIG. 5 is an overall schematic view of a conventional injection molding device for metal molded bodies. The metal molding injection molding apparatus 100 includes a screw type injection machine 101 and a material supply chamber 102. The material supply chamber 102 includes, from top to bottom, an ingot introduction chamber 103, a heating chamber 104, a greenhouse greenhouse 105,
It is configured with a chop chamber 107 having a crushing chopper 106. The material supply chamber 102 is maintained in a vacuum or an inert gas atmosphere, and the chambers 103, 104, 105 are partitioned by shutters 108, 109.

In the above conventional technique, the ingot 110 is heated in the heating chamber 104, appropriately moved to the warming chamber 105, crushed by the chopper 106, and directly or indirectly by the screw shaft 111 via the chop chamber 107. It is injected into the cavity 113 of 112. The ingot 110 is made of metal and is characterized in that it is semi-molten by heating in the heating chamber 104 and is injected in this state. In this technique, since heating is performed in the heating chamber 104, transferred to the warming chamber 105, and crushed by the chopper 106, continuous processing is possible and productivity is high.

[0004]

The above-mentioned injection machine is composed of a screw shaft having a spiral groove formed on the outer periphery thereof, and a cylinder fitted with the screw shaft. This cylinder is provided with a supply port at a part of its outer circumference, and from this supply port, a high temperature semi-molten metal which is an injection molding material is introduced between the cylinder and the screw shaft. The molding material introduced into the cylinder is kneaded by the rotation of the screw shaft in a semi-molten state, and is accumulated in the accumulation chamber between the tip of the screw shaft and the inside of the tip of the cylinder in the spiral groove on the outer circumference. The accumulation of the molding material in the accumulation chamber between the tip of the cylinder and the tip of the screw shaft causes the screw shaft to move backward in the axial direction. When the accumulation of the amount of molding material required for injection molding is completed, the screw shaft moves axially forward, and the molding material is injected into the mold cavity to perform molding.

By the way, when the molding material is introduced into the injection machine through the supply port of the cylinder, if the heating of the material is insufficient, the molding material in the crushed and semi-molten state contains excessive solid components. There is a possibility that it will be supplied in a state.
As a result, the solid component of the molding material may cause resistance between the inner circumference of the cylinder and the screw shaft, which may adversely affect the smooth operation of the screw shaft. This may adversely affect the life and durability of the screw shaft and cylinder. Further, the molding material accumulated in the tip portion of the cylinder and the accumulation chamber at the tip portion of the screw shaft tends to shift to a solidified state with the passage of time. In this respect as well, there is a possibility that the smooth injection operation is adversely affected. Further, the screw shaft is formed with a spiral groove, and the molding material is accumulated between this portion and the inner circumference of the cylinder. The accumulated molding material may be conveyed from the high-temperature supply port to the low-temperature rear side as the screw shaft retracts, and tend to solidify in the low-temperature part behind the supply port.
This may adversely affect the smooth operation of the screw shaft.

The present inventors have made the present invention in order to solve such a problem of the injection mechanism of the injection molding device for a metal molded body. INDUSTRIAL APPLICABILITY According to the present invention, the high temperature and heating state of the molding material introduced between the screw shaft and the cylinder, which is optimum for the kneading and injection operations, is surely maintained from the supply of the molding material to the injection. Further, it prevents the generation of resistance due to the solid component between the cylinder and the screw shaft of the molding material. Moreover, at the rear part of the cylinder molding material supply port, which may have a low temperature when the screw shaft moves backward, the solidification tendency of the molding material accumulated in the rear part of the spiral groove of the screw shaft is prevented to prevent the molding material from entering the cylinder. It prevents the solid pulverized material from being mixed and the resistance to the operation of the screw shaft due to the solidification tendency of the molding material. As a total, the above provides an injection molding device for a metal molded body that can ensure smooth, reliable accumulation and injection movement of the molding material by the screw shaft, and can also improve the durability and life of the cylinder and the screw shaft. The purpose is to do.

[0007]

[Means for Solving the Problems] Means for solving the above-mentioned problems are as follows: A screw shaft for injection of a molding material is fitted, and heating means is provided on the circumference of a cylinder inside which the heating means is a spiral groove of the screw shaft. Is an injection molding device for a metal molded body that is installed at least at the last retracted position. Also, the base of the cylinder is supported by a support member, and the support member has a water cooling structure, so that heat transferred from the heating means to the support member is blocked. Further, it is an injection molding device for a metal molded body, in which a drive means for crushing means of a metal ingot is arranged on the support member.

[0008]

According to the above-mentioned means, since the heating means is provided around the cylinder, and the heating means is provided up to the backward movement position of the screw shaft or the range beyond this, the molding supplied and introduced into the cylinder is performed. The material is in the cylinder,
A high temperature is maintained between the screw shaft and the cylinder to prevent the temperature from decreasing. Therefore, the molding material is maintained at the optimum temperature for the injection operation, and the injection operation of the molding material is performed smoothly and surely.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a vertical sectional side view of a main part of an injection molding device for a metal molded body according to the present invention, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, and FIG. FIG. 4 is an enlarged view of FIG. 3 showing a state in which the molding material has been accumulated in the stock space between the inner side and the tip of the screw shaft and the measurement of the injection molding material has been completed, and a temperature distribution of the cylinder. .

The mold and the like have been described with reference to FIG. 5 as a whole structure, and therefore the description thereof will be omitted, and only the essential parts will be described.
FIG. 1 is a vertical cross-sectional side view of a main part of an injection molding device 1 for a metal molded body according to the present invention, which includes an injection machine 4 including a screw shaft 2 and a cylinder 3 into which the screw shaft 2 is fitted. A material supply chamber 5 for supplying a molding material to the injection machine 4 is provided on the injection machine 4, and the material supply chamber 5 includes, as shown in detail in FIG. The heating chamber 7 is provided below, and the greenhouse 8 is provided below this. In the lower part of the greenhouse 8, there is a crushing device 2 coaxially with the injector 4.
Crushing material accumulation chamber 1 with individual crushing cutters 9, 9 on top
0s are arranged vertically.

Drive shafts 11, 11 of the crushing cutters 9, 9
Is an input shaft 1 on the upstream side and an output shaft 2 via the free shaft 12.
It is connected to the two-shaft gear case 13, is further connected to the speed reducer 14 arranged on the upstream side, and is connected to the one motor 15 on the upstream side, and these constitute the driving means 16 of the crushing means. Two
The individual crushing cutters 9, 9 rotate in opposite directions.

An ingot introduction chamber 6 and a heating chamber 7 below this
A shutter 17 is provided between and, and the ingot W is introduced into the heating chamber 7 directly below by opening the shutter 17. Heating chamber 7
2 is a cylindrical ceramic holder 1 as shown in FIG.
8, a vacuum container composed of an induction heating coil 19, a magnetic shield material 20, and an outer cylinder 21 on the outer periphery of the vacuum container. The heating chamber 7 has an upper opening hermetically closed by the shutter 17 and a lower opening hermetically closed by a shutter 22, and a stopper 23 for the ingot W is provided under the holder 18. The ingot W has a stopper 23 inside the holder 18 during heating.
And is heated to a predetermined temperature, and the temperature is monitored by a radiation thermometer 24. The heating chamber 7 heats the ingot W in a vacuum or an inert gas atmosphere.

The heating chamber 7 communicates with and is connected to the greenhouse 8 immediately below, and the shutter 22 described above is interposed therebetween.
The greenhouse 8 is covered with the heat-retaining heater 25 and the heat insulating material tube 26, and has a height enough to store one ingot W. The upper part of the greenhouse 8 is connected to a vacuum / inert gas pipe 27, and a valve (not shown) switches the flow path to evacuate or to supply an inert gas.

Immediately below the greenhouse 8, the crushing cutters 9 and 9 are provided so as to communicate with each other, and below the cutters 9 and 9, there is provided a storage chamber 10 for storing the crushed molding material. To be The storage chamber 10 has a certain level of height, and includes a high level sensor 28 and a low level sensor 29 that are separated in the height direction.

Below the above-mentioned storage chamber 10, the cylinder 3 of the above-mentioned injection machine 4 is provided, and the injection hole 33 of the cylinder 3 is provided.
The front end injection part 32 including is facing the molding material introduction path 31 of the mold 30. The cylinder 3 is shown in FIG. 3 and an enlarged view of FIG.
As shown in FIG. 3, the inner wall 34 of the inner wall has a thin inner wall 34, and the outer wall 35 of a thick wall covers the outer wall of the inner wall 34.
0a is a supply port 3 formed at a rear portion in the axial direction of the cylinder 3.
6 is connected to and connected to 6 to supply the molding material into the cylinder 3.

The rear portion 35a of the outer cylinder 35 extends axially through the front portion 37a of the support base 37 as a support member and extends rearward, and the rear portion 34a of the inner cylinder 34 is also fitted inside the outer cylinder 35. Is similarly extended to the rear, and the rear end portion 3a of the cylinder 3 is
Supports the rear portion of the screw shaft 2 via the seal 38 and the metal 39. The rear end portion 2a of the screw shaft 2 extends rearward of the rear end portion 3a of the cylinder 3, and the rear end portion 2a of the screw shaft 2 and the cylinder 3
The rear end portion 3a faces the hollow portion 37b in the support base 37. The rear end portion 2a of the screw shaft 2 is connected to an advancing / retreating shaft 41 via a joint portion 40, and the advancing / retreating shaft 41 is
It is connected to a rod such as a cylinder unit (not shown) that rotates and moves back and forth.

Outside the outer cylinder 35 of the cylinder,
A heater 42 (... indicates a plurality, hereinafter the same applies) serving as a heating means is provided so as to cover the circumference of the heater 42.
Is formed by connecting block tubular members in series. Heater 4
The outer periphery of 2 is covered with a heat insulating material 43 formed by connecting block cylindrical members in series. Therefore, the inner cylinder 34 and the outer cylinder 3 of the cylinder 3 in which the screw shaft 2 is fitted and incorporated
No. 5 is heated and heated as necessary, and is also heated for heat retention.

A flange portion 35b is formed in the rear portion of the molding material supply port 36 in the middle rear portion of the outer cylinder 35, and the rear end surface 35c of the flange portion 35b is attached to the support base 3.
The front end surface 37c of 7 is abutted via the heat insulating material 44, and the outer cylinder 35 is joined and integrated with the support base 37 by a bolt or the like not shown. A rear portion of the flange portion 35b of the outer cylinder 35 has a small outer diameter, and a rear portion having a small diameter extends into the cavity portion 37b through a cylinder hole 37d formed in a front portion 37a of the support base 37. .

In the cylinder 3 described above, the heaters 42 arranged around the outer cylinder 35 cover the outer circumference from the base of the tip injection portion 32 of the outer cylinder 35 until just before the flange 35b. To install. The circumference of the supply port 36 forming an opening is provided so as to surround this circumference. Heater 42
The installation range of ... Is set up to the backward movement limit of the screw shaft 2 shown in FIG. 4, or a little behind the backward movement limit. 1, 3, and 4, reference numeral 45 denotes a thermometer that measures the temperature distribution of the cylinder 3 in the axial direction, measures the cylinder temperature distribution of the injector 4, and heats the heaters 42.
Control such as heating stop is configured to be performed by a control device (not shown).

By the way, the front portion 3 of the support base 37 described above.
In 7a, an annular cooling water passage 46 is provided so as to face the outer circumference of the cylindrical hole 37d that fits and covers the circumference of the small-diameter outer cylinder fitting portion 35d and surrounds it. The cooling water passage 46 introduces the cooling water from the supply hole 47 on the upper side of the drawing and discharges the cooling water from the discharge hole 48.
The cooling water passage 46 cools the front part of the support base 37 to suppress and prevent the thermal influence of the injector 4 from spreading to the support base 37. The cooling water passage 46, the supply hole 47, and the discharge hole 48 constitute a cooling means 49.

Therefore, since the support base 37 of the injection machine 4 is kept at a low temperature by the cooling means 49, the upper surface 3 of the support base 37 is maintained.
The drive means 16, which is not preferably thermally influenced, that is, devices such as the motor 15, the speed reducer 14, and the biaxial gear case 13 are disposed on the 7e. As a result, even if the drive means 16 for the crushing cutters 9 and 9 are arranged adjacent to the high temperature injector 4, the support base 37, which is the drive means installation base, is cooled and kept at a low temperature. It is possible to prevent each of the devices 15, 14, 13, 12 constituting the drive means 16 from being thermally affected by the injection machine 4.
Further, since the support base 37, which serves as the drive means installation base, is cooled and kept at a low temperature as described above, the span between the devices can be shortened. Therefore, the size of the entire device can be reduced.

The screw shaft 2 is provided with a sharp screw tip portion 51 at the tip portion and a spiral groove 52 on the outer periphery. The groove 52 is provided up to an intermediate portion in the axial direction as shown in FIG. FIG. 1 shows a molding material accumulation start position in a state where the molding material is not accumulated. In this state, the screw tip portion 51 fits into the injection chamber 50 formed by the tapered hole of the tip injection portion 32 on the cylinder 3 side with a gap, and in this state, the rear end portion 52a of the spiral groove 52 is ,
It is formed right after the supply port 36 of the cylinder 3 described above. The rear of the rear end portion 52a of the spiral groove 52 of the screw shaft 2 is formed in an axial shape and extends rearward as described above. Therefore, the above-mentioned heaters 42 ... Are installed up to a predetermined axial direction position behind the rear end portion 52a of the spiral groove 52 of the screw shaft 2 in the state of starting the accumulation.

By the way, in the graph showing the temperature distribution of the injector 4 shown in the lower part of FIG. 3, the horizontal axis represents the axial position of the injector 4,
The vertical axis indicates temperature. Injection machine 4 including heater 42
The temperature is maintained at a high temperature from the position "a" of the end of the cylinder to the position "b" before the flange 35b of the outer cylinder 35 of the cylinder 3. As described above, the cooling water passage 46 is provided at the rear of the flange portion 35b.
The cooling means 49 consisting of is provided on the front portion 37 a of the support base 37. As a result, the heat transfer action causes the flange portion 35 to
From the high temperature position b near the upstream of b, the temperature suddenly drops with a descending gradient. A heat insulating material 44 is provided on the front end surface 37c of the support base 37. At the position c of this surface, a steep temperature drop becomes a gentle downgrade, and the temperature gradually decreases. Keep 37 cold.

As described above, the injection machine 4 is preferably injection molded with the heater 42 and the injection machine 4 which are preferably kept at a high temperature, and the cooling means 49 which is a support base 37 which is preferably kept at a low temperature. It can be maintained at the required high temperature and the required low temperature for the drive means 16 of the crushing means.

In the above, FIG. 1 shows the state before the accumulation of the molding material as described above. The ingot W crushed by the crushing cutters 9, 9 is temporarily stored in the lower storage chamber 10 as a semi-solid crushed material. Accumulated. The crushing of the ingot W is continuously performed, and therefore, the supply port 36 is provided with the accumulation chamber 10
The molding material is continuously supplied to the cylinder 3. The molding material that has become this semi-solid crushed material is
Is introduced into the inner cylinder 34 of the cylinder 3, enters between the spiral groove 52 of the screw shaft 2 and the inner circumference of the inner cylinder 34, and is rotated toward the injection chamber 50 in the front part of the cylinder 3 by the rotation of the screw shaft 2. To be In this process, the molding material is in a semi-molten state because the cylinder 3 is heated as described above and is in a high temperature state, and is kneaded and sent into the injection chamber 50 at the tip.

The semi-molten molding material sent by the rotation of the screw shaft 2 is sequentially accumulated in the injection chamber 50,
As the accumulation progresses, an axial force for moving the screw shaft 2 backward acts on the screw tip portion 51 at the tip end of the screw shaft 2, and the screw shaft 2 retracts axially rearward. By supplying the molding material, feeding the molding material forward by the rotation of the screw shaft, and continuing the backward movement of the screw shaft 2, the molding material is accumulated in the injection chamber 50, so that the tip of the inner cylinder 34 of the cylinder 3 is The stock space 53 for stocking the semi-molten molding material is constituted.

FIGS. 3 and 4 show the backward movement limit of the screw shaft 2. In the stock space 53, the molding material that is maintained in a semi-molten state ready for injection is accumulated. At the backward movement limit position of the screw shaft 2, the rear end portion 52a of the spiral groove 52 around the screw shaft 2 is formed.
Are provided up to this partial circumference on the outer circumference of the cylinder 3. Therefore, the heaters 42 are heated up to the rear part of the spiral groove 52 moved to the rear of the supply port 36 by the backward movement of the screw shaft 2. .

Therefore, the molding material accumulated in the stock space 53 in the front part of the cylinder 3 and the molding material remaining in the spiral groove 52 on the outer periphery of the screw shaft 2 are supplied from the starting point of the spiral groove 52 to the molding material supply port. 36
Up to the rear end portion 52a of the rear portion is maintained at a high temperature by the action of the heaters 42 ... As described above, and the semi-molten state is maintained. Therefore, the temperature drop of the molding material that is kneaded by the screw shaft 2 and sent, and accumulated in the stock space 53 is reliably prevented. Therefore, the molding material in the cylinder 3 will not be a solid crushed material, and will not tend to solidify in the cylinder 3.

As described above, when the molding material is kneaded and fed by the screw shaft 2, the screw shaft 2 is smoothly rotated and slid. It is possible to eliminate inconveniences such as resistance of driving the screw shaft 2 due to biting between the screw shaft 2 and the cylinder 3 due to mixing of excessive solid pulverized material and the like, which is a problem of the present invention. Therefore, the screw shaft 2 of the injection machine 4
The operation of feeding, kneading, accumulating, and injecting the metal molding material can be performed extremely smoothly and surely.

Although the embodiment has been described in detail above, in FIGS. 3 and 4, the rear end portion of the heater 42 and the rear end portion 52a of the spiral groove 52 of the screw shaft 2 in the backward limit are substantially aligned with each other. Configured. The rear end of the heater 42 may be extended to the rear of the rear end 52a.

[0031]

As apparent from the above, according to the present invention,
A cylinder, a heating means is provided around the cylinder of an injection machine, which is formed of a screw shaft fitted and installed inside the cylinder.
Since the heating means is provided up to the final retracted position of the outer peripheral groove of the screw shaft, the molding material supplied and introduced into the cylinder is heated to the final end of the groove within the operating range of the screw shaft and is maintained at a high temperature. . Therefore, even if solid pulverized material, etc. is mixed in, it will immediately be heated sufficiently and will be in a rapidly molten state, and the molding material will be caught between the cylinder inner circumference and the screw shaft, and the screw shaft will rotate and slide. Generation of resistance such as resistance can be prevented in advance. As a result, the rotation of the screw shaft in the cylinder, the accumulation of the molding material due to the sliding of the screw shaft, the feeding of the material, and the storage of the material between the grooves can be performed smoothly and reliably without resistance.

Therefore, the occurrence of injury to the cylinder and the screw shaft due to the malfunction of the screw shaft due to the rotation and sliding resistance of the screw shaft due to the mixing of the solid pulverized material and the like is eliminated. The life and durability of the shaft can be improved, and the functionality, life and durability of the injection machine can be improved as a whole. In addition, this allows smooth and reliable injection molding.

Further, in the present invention, since the cooling means such as the cooling water passage is provided in the supporting member which supports the base portion of the screw shaft, the portion supported by the supporting member of the cylinder is partitioned from the cylinder of the high temperature portion and is cooled at a low temperature. The parts can be configured.
Therefore, it is possible to maintain the supporting member at a low temperature and to install the driving means of the crushing cutter on the supporting member, which is required to avoid thermal influence. This drive means can be installed adjacent to the high temperature cylinder,
As a result, it is not necessary to take a large span between the driving means and the high temperature cylinder, and it becomes possible to downsize the entire molding apparatus including the driving means.
The seed molding apparatus can be downsized.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a main part of an injection molding device for a metal molded body according to the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a vertical cross-sectional side view of the injection machine part, showing a state in which the molding material has been accumulated in the stock space between the inside of the cylinder tip and the screw shaft tip and the injection molding material has been measured, and the temperature distribution of the cylinder. Explanatory graph showing

FIG. 4 is an enlarged view of FIG.

FIG. 5 is an overall schematic view of a conventional injection molding device for metal molded bodies.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Injection molding apparatus for metal molded bodies, 2 ... Screw shaft, 3 ... Cylinder, 16 ... Crushing means drive means, 36 ...
Supply port, 37 ... Support member (support base), 42 ... Heating means (heater), 49 ... Cooling means, 52 ... Spiral groove, 5
3 ... stock space, W ... ingot (metal ingot).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noboru Kai 1-10-1 Shin-Sayama, Sayama-shi, Saitama Prefecture Honda Engineering Co., Ltd. (72) Hiromitsu Suganuma 1-10-1 Shin-Sayama, Sayama-shi, Saitama Prefecture Within Honda Engineering Co., Ltd.

Claims (3)

[Claims] 1. An injection molding device for a metal molded body, comprising: a cylinder; a screw shaft moving back and forth in the cylinder; and a supply port for supplying a semi-molten metal material into the cylinder in a part of the cylinder periphery. A heating means is provided around the cylinder, and the heating means is installed up to at least the rearmost position of the spiral groove of the screw shaft. 2. A support member supports the base of the cylinder,
The injection molding apparatus for a metal molded body according to claim 1, wherein the support member has a water cooling structure so as to block heat transmitted from the heating means to the support member. 3. The injection molding apparatus for a metal molded body according to claim 2, wherein a drive means for crushing the metal ingot is arranged on the support member.