JP3081982B2 - Manufacturing method of metal parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a metal powder injection molding technique (METAL INJECTION MOLDING, hereinafter referred to as MIM).
And a method for manufacturing a metal part.

[0002]

2. Description of the Related Art Conventionally, deburring of a molded body has been removed by a mechanical method using a brush, an air gun or the like. For this reason, there is a disadvantage that a great deal of time and labor are required, and the cost of the product is increased.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and is capable of performing deburring of a molded body in a short time.

[0004]

Means for Solving the Problems MIM is a method in which a metal powder and a binder are well kneaded (mixed and kneaded), then pelletized, and then injected into a mold by an injection molding machine to form a molded body, which is contained in the molded body. This is a technology for manufacturing components by removing the binder and sintering. When manufacturing a molded article, burrs often occur on the molded article depending on molding conditions. Since the burrs remain without being removed even in the steps of degreasing and sintering, they need to be removed after molding. The present invention utilizes water pressure as a method for removing the burrs. The molded body with the burr is immersed in a water tank filled with a predetermined amount of solvent.
Burrs are removed by spraying water on the molded body. At this time, if high-pressure water is sprayed, the molded article may be roughened or damaged, so it is desirable to set the water pressure to an appropriate level.

In the present invention, a higher effect can be obtained if a binder eluted in the solvent in the ultrasonic bath is mixed as a binder in the MIM. As a solvent, an organic solvent such as benzene and toluene can be used in addition to water. Also, as a medium,
Air can also be used.

[0006]

In the above process, when removing burrs, by increasing the nozzle width and the number of nozzles for water spraying, a large number of components can be set at once, and then the burrs can be removed by water pressure. The efficiency of the process can be increased. At this time, since the removed burrs are washed away by the water as the medium, there is also an effect of preventing the burrs from being attached to the molded body again.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 shows a state in which burrs 9 removed by applying spray water 8 to a formed body with burrs by a spray nozzle 7 are removed from the formed body.

(First Embodiment) A first embodiment of the present invention will be described in detail with reference to FIG. A 316LSUS metal powder having an average particle size of 8 to 10 μm and a water-soluble binder (polyethylene oxide) were kneaded well and pelletized, and then molded into a product shape by an injection molding machine to obtain a molded body 4. A tank 1 filled with a predetermined amount of a solvent 2 such as water
(A in FIG. 2), and after several hours, it was confirmed that the water-soluble binder was extracted and the burr of the molded body became brittle (FIG. 2, B), and the molded body was taken out of the water tank and became brittle. Using a specific nozzle, the burr 6 is pressurized with high pressure water (about 1.5 to 2.5 kg).
/ Cm ² ) (FIG. 2,
C).

(Embodiment 2) A second embodiment of the present invention will be described with reference to FIG. 316 having an average particle size of 8 to 10 μm
The LSUS metal powder and a water-soluble binder (polyethylene oxide type) were kneaded well, pelletized, and then formed into a product shape by an injection molding machine to obtain a molded product 4. The compact 4 was set in the tank 1 filled with a predetermined amount of the solvent 2 such as water (FIG. 2, A), and after several hours, it was confirmed that the water-soluble binder was extracted and the burr of the compact became brittle. (Figure 2,
B) The molded body was taken out of the water tank, and the brittle burr 6 was pressed with water and air at a high pressure (about 1.5 to 3.0K) using a specific nozzle.
g / cm ² ) (FIG. 2,
C).

[0010]

As described above, according to the present invention, burrs can be removed neatly and a large amount of burrs can be removed at a time, so that the efficiency of the process is remarkably improved. be able to. In addition, since water is sprayed, the removed burrs can be prevented from attaching to the molded body again. In addition, no adverse effect (skin roughness, breakage) on the molded product due to the water pressure was observed.

[Brief description of the drawings]

FIG. 1 is a diagram in which water is sprayed on a molded product with burrs.

FIG. 2 is a diagram showing a process of removing burrs by water pressure according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 tank 2 solvent 3 molded body burr 4 molded body 5 molded body supporting surface 6 burr made brittle by immersion 7 spray nozzle 8 sprayed water 9 removed burr

Claims (3)

(57) [Claims] 1. A method for manufacturing a component comprising a kneading step of a metal powder and a binder, an injection molding step, a binder removing step, a sintering step, and a step of removing a burr of a formed body, wherein the burr of the formed body is removed. In the process, a method for manufacturing a metal component, comprising immersing a molded body in a solvent to reduce the strength of burrs and removing burrs by water pressure. 2. The method according to claim 1, wherein water is used as the solvent. 3. The method for producing a metal part according to claim 1, wherein the sprayed water prevents the removed burrs from re-adhering to the molded body.