JPH06192703A - Method and device for taking out injection-molding - Google Patents

Abstract

PURPOSE:To eliminate the wear and deformation of a mold when the molding is taken out by this device and to stably supply the high-precision molding for a long period by completely removing the bur and remaining product from the split surfaces of the mold. CONSTITUTION:A mixture consisting of a soft magnetic powder and a binder with a high molecular compd. as the main component is injected into a mold, the obtained molding 12 is thrust out on a movable die 10 by an injector from the split surfaces of the opened mold, a magnetizing unit consisting of a permanent magnet 5, magnetized disk 7, non-magnetized disk 6, arm 8, air cylinder 1 and air cylinder 2 is lowered between the movable die 10 and a fixed die 11 and firmly attached to the molding 12, and the ramains are completely collected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for taking out an injection molded body, and more particularly to a method and a device for taking out an injection molded body composed of a soft magnetic powder and a binder whose main component is an organic polymer compound.

[0002]

2. Description of the Related Art Injection molding is most characterized in that a molded body having a complicated shape can be repeatedly obtained with high dimensional accuracy, and has been used for molding plastics. In recent years, however, metal powder has been used because of its high dimensional accuracy. It is also actively applied to ceramic powder. An automatic take-out device has been devised and put into practical use for the purpose of saving labor in these molding steps. Generally, an automatic take-out device is used when the mold is opened from the split surface, the arm tip equipped with a molded body collection function catches the molded body that is ejected by the ejector to the movable mold surface, Also, it is taken out from between the movable molds and moved to a molded body collecting case or the like near the injection molding machine. Generally, there are the following methods for capturing a molded body. It is one that captures the molded product sprue with the arm part divided into two, or one that has a suction pad and a decompression device and creates a decompressed state near the molded product and captures it with a pad that approaches the molded product. ..

[0003]

The injection molding method can be mass-produced with high accuracy and does not require finishing processing after molding, so that it is applied to metal and ceramic powders. Furthermore, automatic take-out devices have come into general use for the purpose of saving labor.

The molds used in these injection moldings include high carbon steel and those obtained by subjecting carbon steel to heat treatment such as quenching and tempering to provide high toughness. Since the mixture of the metal powder and the ceramic powder and the binder contains the powder, it has a high viscosity as compared with the plastic. Therefore, a high injection speed is required at the time of injection, and burr is often generated. Furthermore, the adhesion of the remaining portion of the molded body to the mold surface is important. Since these powders have a higher hardness than plastics, the abrasion and erosion applied to the mold are extremely severe. That is, the adhesion of the unremoved part to the mold surface after taking out the molded body deforms the mold surface when the mold is closed, and particularly when it is close to the product part, the dimensional accuracy of the product is deteriorated, which is a serious problem.

In the case of the conventional take-out device, it is impossible to remove the burrs and the residual product, which results in accelerating the deformation of the mold dividing surface.

The problem to be solved by the present invention is to take out a molded product which is capable of simultaneously removing a molded product and completely removing burrs and product leftovers from the mold surface, and supplying a highly accurate molded product stably for a long period of time. Providing a method and an apparatus.

[0007]

The method of taking out an injection-molded article of the present invention is a molding obtained by injecting a mixture comprising a soft magnetic powder and a binder containing an organic polymer compound as a main component into a mold. The body is characterized in that the mold is opened from the mold dividing surface, the magnetizing unit is brought into close contact with the molded body on the mold dividing surface, and the molded body is magnetically attracted and reliably taken out.

Further, in the apparatus for taking out an injection-molded body having the magnetizing unit as a main constituent element, the magnetizing unit uses a permanent magnet or an electromagnet.

[0009]

The present invention was made by paying attention to the fact that all metal powders and ceramic powders except stainless steel and ceramics having a high content of additive elements have magnetism. Further, according to the present invention, in the deformation of the injection molding die, burrs are generated in the initial stage due to erosion due to abrasion, and the burrs adhere to the die dividing surface, and the unretained portion of the molding adheres to the die dividing surface. And, by discovering the fact that the deformation of the mold is accelerated because these cannot be completely removed. Therefore, the magnetic attraction force allows the mold split surface to be completely taken out without leaving any burrs or moldings, so that the mold split surface can be prevented from being deformed.

[0010]

Embodiments of the present invention will be described with reference to the drawings.

[0011]

First Embodiment FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention. The magnetizing unit includes a magnetizing plate 7 made of mild steel having a Teflon plate 6 on one surface, a ferrite magnet 5 that can be attached to and detached from the magnetizing plate 7 by the air cylinder 1, and an arm that can keep the Teflon plate 6 and the ferrite magnet 5 parallel to each other. 8 and an air cylinder 2 for bringing the Teflon board 6 into close contact with the formed body. The magnetizing unit can be moved up and down by the air cylinder 3.

As the soft magnetic powder, 86.5 parts by weight of Ni-Zn ferrite calcined powder, 5 parts by weight of vinyl acetate copolymer, 3 parts by weight of polybutyl methacrylate and 5.5 parts by weight of paraffin wax were mixed. , 13 in the atmosphere with a pressure kneader
The mixture was kneaded at 0 ° C for 30 minutes to obtain a mixture. After cooling this to room temperature, it was pelletized using a disintegrator to obtain a mixture for molding.

This molding compound is attached to an injection molding machine (not shown), and the movable mold 10 in which the mold dividing surfaces are in close contact with each other,
It is melted at a cylinder temperature of 160 ° C. between the fixed molds 11 and injected.

After the raw material injected into the mold is cooled,
The movable die 10 and the fixed die 11 are opened, and the molded body 12 is projected from the movable die surface by an ejector (not shown). At the same time as the ejection, the take-out device lowers the magnetizing unit between the movable die and the fixed die by the air cylinder 3, and further brings the Teflon plate 6 into close contact with the molded body ejected from the movable die by the air cylinder 2, and then the air cylinder 1 Then, the ferrite magnet 5 was brought into close contact with the magnetic plate 7. Then, the Teflon plate 6 is separated from the movable mold division surface by the air cylinder 2, the magnetizing unit is raised by the air cylinder 3, and then the movable mold 1 is moved.
0 and the fixed mold 11 were brought into close contact with each other for molding in the next cycle.
During this time, the magnetizing unit which has caught the compact is moved by an air cylinder 4 via an arm 9 onto a compact collecting case (not shown) on the side of the compactor, where the ferrite 5 is removed from the mild steel strip magnetic plate 7 by air. The cylinder 1 is pulled apart, and the compact is dropped into the collection case.

The above-mentioned series of steps is conducted under visual supervision.
As a result of repeating 000 cycles, there was no unmolded body left. Further, as a result of visually observing the divided surface of the mold with a magnification of 50 times, no admixture was confirmed, and no deformation of the divided surface was confirmed.

[0016]

Second Embodiment FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention. The magnetizing unit is a coil 15 and a pole piece 1.
Electromagnet composed of 3 and soft steel magnetic porcelain plate on both sides 1
4 is provided, and a Teflon board 6 is attached to the side that comes into close contact with the molded body 12. The air cylinder 3 can move up and down, and the air cylinder 4 can rotate through the arm 9.

An example of using the same raw material as in Example 1 and using the take-out apparatus of FIG. 2 will be described. After the raw material injected between the movable mold 10 and the fixed mold 11 is cooled at a cylinder temperature of 160 ° C., the mold is opened from the dividing surface, and the molded body 12 is ejected by an ejector (not shown) of the movable mold 10. The magnetizing unit is lowered between the movable mold and the fixed mold by the air cylinder 3, and the magnetizing plate 14 is brought into close contact with the molded body by the air cylinder 2. Next, the magnetizing unit is magnetized by the exciting power source 16 and the molded body 12 is captured by the magnetizing plate 14. After that, the unit is lifted by the air cylinder 3, and the magnetized unit holding the molded body by the air cylinder 4 with the arm 9 interposed therebetween is moved to the case on the side of the molding machine by the rotary motion. Here, the excitation of the electromagnet is stopped and the compact is dropped into the case. After repeating this cycle 1000 times, the movable mold-divided surface was observed. As a result, there was no residue left, and neither admixture adhering nor deformation of the mold-divided surface was confirmed.

[0018]

[Comparative Example] The results of molding with a conventional molded body take-out device attached are shown below. As a result of repeating the above-mentioned molding process for 500 cycles under visual monitoring, it was confirmed that there were three leftovers. Further, as a result of visually observing the mold division surface, admixture was confirmed around the runner and the cavity. At this point, no deformation of the mold was confirmed. Furthermore, as a result of molding for 500 cycles, a residual portion was confirmed 5 times, and as a result of observing the divided surface, the admixture adhering to the surroundings of the runner and the cavity increased, and after removing these, the runner was removed. As a result of measuring the surface roughness of the periphery and the periphery of the cavity, a depression of 1 to 5 μm was confirmed. The process of this deformation is as follows. During injection, the admixture forms burrs around the runner and the cavity, and after the molded body is taken out, these burrs are left behind and adhered to the mold dividing surface. By repeating the molding cycle, the mold dividing surface is deformed, which induces new burrs, the amount of burrs is further increased, and the deformation of the mold is also increased.

[0019]

As described above, according to the method for taking out a molded body of the present invention, when the injection molded body is taken out, it is possible to collect the molded body by a magnetic force and completely remove the admixed mixture, and there is no leftover. Therefore, when the molding cycle is repeated, it is possible to prevent damage due to deformation of the mold dividing surface. Therefore, the life of the mold can be extended and a product with high dimensional accuracy can be supplied for a long period of time, which is extremely important industrially.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an outline of a method for taking out a molded body of the present invention.

FIG. 2 is an explanatory view showing the outline of another method for taking out a molded body of the present invention.

[Explanation of symbols]

 1,2,3,4 Air cylinder 5 Ferrite magnet (permanent magnet) 6 Teflon board (non-magnetic board) 7,14 Band magnetic board 8,9 Arm 10 Movable type 11 Fixed type 12 Molded body 13 Pole piece 15 Coil 16 Excitation power supply 17 sprue

Claims (3)

[Claims] 1. A method for removing a molded product obtained by injecting a mixture comprising a soft magnetic powder and a binder containing an organic polymer compound as a main component into a mold, wherein the molded product is on a divided surface of the mold. A method for taking out an injection-molded body, comprising: closely adhering a magnetizing unit to the magnetically adsorbed unit and magnetically adsorbing the molded body. 2. The magnetizing unit according to claim 1, comprising a permanent magnet, a magnetizing plate, a non-magnetic plate, an arm and an air cylinder, and the non-magnetic plate is located between the molded body and the magnetizing plate. A device for taking out an injection-molded body, characterized by: 3. The magnetizing unit according to claim 1, an electromagnet,
An injection molded product take-out device comprising a magnetic porcelain plate and a non-magnetic plate, and the non-magnetic plate is located between the molded body and the magnetic porcelain plate.