JPH11350003A - Manufacture of parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the bonding strength of a part with an adhesive by forming a straight or lattice-like groove in a part of a formed body, heating and pressing a surface to be plastically deformed, narrowing the groove more at a part close to the surface than a part inside thereof to achieve the degreasing and sintering, and to make it difficult for the cured adhesive to project from the groove. SOLUTION: In a powder injection molding method, an organic binder is added to the fine powder of a metal or a ceramic, kneaded to form a pellet, and the pellet is injection-molded in a die. A formed body is heated to be softened after the forming, the formed body is pressed by a heated iron or a hot plate to reduce the width of an opening part of a groove. In a case of a teeth-straightening piece, the groove of the teeth-straightening piece having a rectangular plate having a straight groove on the surface and a projecting part for holding a wire on a back surface is narrowed at a part closer to the surface than at a part inside thereof, the adhesive becomes anchor-like in the groove, and the adhesive strength is increased. The epoxy or silicone adhesive is used. After a surface A with the groove 2 is adhered to a tooth, the wire is wound around a projecting part 1 to provide the tension.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder injection molding technique for producing parts using powders of metals, ceramics and the like.

[0002]

2. Description of the Related Art Conventionally, when an adhesive or the like is applied to the back surface of a component made of metal, ceramics, or the like, and is adhered to another object, if the surface is smooth, the adhesive strength is low, so that the adhesive surface is roughened. It has been tried to increase the bonding strength by forming a shallow groove to increase the bonding area. However, even if such a measure is taken, a sufficient bonding strength cannot be obtained because the bonding strength between the component and the adhesive is weak.

[0003]

SUMMARY OF THE INVENTION The present invention eliminates the above-mentioned disadvantages and makes it difficult for the cured adhesive to fall out of the groove, thereby increasing the adhesive strength between the component and the adhesive.

[0004]

According to the present invention, the shape of the groove formed on the surface of the component is made narrower at the portion closer to the surface than at the inside, so that the cured adhesive is hardly removed from the groove and adheres to the component. The adhesive strength is increased by increasing the adhesive strength of the agent.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a powder injection molding method in which a pelletized material obtained by mixing a binder with powder is molded in a mold, and then degreased and sintered. The present invention relates to a method for manufacturing a part, characterized in that the surface of a molded body is heated and pressed, and then plastically deformed to make the shape of the groove narrower in a portion closer to the surface than in the inside.

In the powder injection molding method, an organic binder is added to fine powder of metal, ceramics or the like, kneaded to form pellets, and then injection molded in a mold to form a molded body. Parts are manufactured by tying. At this time, the organic binder is added to give fluidity to the powder so that molded parts can be easily molded by injection molding. However, since molding is usually performed at about 150 ° C. to 250 ° C., the temperature is increased depending on the amount added. It is adjusted so that the liquidity at the time becomes appropriate. The molding is usually solidified at around normal temperature and is in a state where it can be easily handled. By forming a shallow groove in the part when manufacturing this part, a part having a groove in the sintered part can be manufactured.

However, in the case of a use form in which this part is glued to another object with an adhesive, in order to increase the adhesive strength, in order to prevent the solidified adhesive from coming out of the groove, the groove is tapered reversely. Or the width of the groove opening must be smaller than the internal width of the groove. However, in injection molding, it is very difficult to manufacture a mold so as to achieve the above object.

Therefore, in the present invention, attention is paid to the fact that the molded body in powder injection molding is softened by increasing the temperature, and after molding with a mold having grooves formed in a desired shape, the molded body is softened by heating. The width of the opening of the groove is made smaller than the width of the inside of the groove by pressing the molded body with a heated iron or a hot plate or the like. Thereafter, by degreasing and sintering the molded body, it is possible to obtain a component having high adhesive strength when attached to another component using an adhesive. The pattern of the grooves formed in the molded body can be various patterns, but typically, the grooves can be formed in a linear shape or a lattice shape having a certain groove width.

The present invention can be applied to, for example, forming a fine groove on the back surface of a minute component such as an orthodontic appliance to increase the adhesive strength of the component to teeth. According to the present invention, since the adhesive is anchored in the groove, the adhesive surface and the component are hardly peeled off, and the adhesive strength is increased. The object of the present invention can also be achieved by crushing the back of the component after sintering, but after sintering, the hardness of the sintered component is high, so that the deformation is small and the adhesive effect of the adhesive in the groove is small. Ceramics cannot be processed after sintering due to their brittleness.

[0010] Such an effect of increasing the adhesive strength is particularly large in the case of fine components, but can be applied to large components. The material can be either metal or ceramic, but in the case of orthodontics, stainless steel, titanium,
Zirconia or the like is used. The material can be any of metal and ceramics. As a method of applying heat to the injection molded body, it is preferable to heat the molded body to a temperature at which the molded body is plastically deformed without being damaged. However, if the temperature is too high, the molding groove is melted and broken. For processing, press a heating plate according to the surface shape of the part to be plastically deformed.
Alternatively, it can be performed by a method such as rolling a heated roll on the surface.

The shape of the groove can be linear, triangular, square, hexagonal, circular or the like. Further, an epoxy-based, silicon-based adhesive, or the like is used as an adhesive for bonding the components.

[0012]

EXAMPLES Example 1 A part as shown in FIG. 1 in which projections were formed on a square plate of 8 * 4 * 0.5 mm was formed of SUS630 material. At this time, the surface opposite to the surface having the projection is
A plurality of grid-like grooves having a width of 0.2 mm and a depth of 0.2 mm as shown in FIG. This groove is formed at 170 ° C after molding.
It was plastically deformed as shown in FIG. 2 by pressing with a heating plate at 50 ° C. The molded body was degreased and then sintered at 1300 ° C. to form a part whose cross section is schematically shown in FIG.
In FIG. 3, the surface A is the bonding surface. When used as an orthodontic appliance, a wire is wound around the protrusion 1 to apply tension after the surface A is adhered to the tooth. When this part was bonded with an adhesive, the adhesive strength was increased about 2.1 times as compared with the part which was degreased and sintered as molded. Example 2 Parts having the same shape as in Example 1 were manufactured using zirconia ceramics. At this time, a width of 0.2 mm and a depth of 0.2 m as shown in FIG.
A plurality of m-shaped linear grooves were formed. The grooves were molded at 175 ° C. and pressed by a heating plate at 160 ° C. to be plastically deformed.
The molded body was degreased and then sintered at 1430 ° C. to form a part. When this part was bonded with an adhesive, the adhesive strength was increased by about 1.9 times as compared with a part degreased and sintered as molded.

[0013]

As described above, according to the present invention, by forming a groove for strengthening the bonding with the adhesive in a part manufactured by the powder injection molding method, it is difficult for the cured adhesive to come off from the groove, and the bonding strength between the part and the adhesive is improved. It was raised.

[Brief description of the drawings]

FIG. 1 (a) is a schematic side view of a molded component according to the present invention, and FIG. 1 (b) is a schematic plan view when a lattice-like groove is formed on the back surface.

FIG. 2 is a schematic side view when a molded body is plastically deformed.

FIG. 3 is a schematic side view of a component after sintering.

FIG. 4 is a schematic plan view when a linear groove is formed.

[Explanation of symbols]

 1 Projection 2 Groove

Claims (3)

[Claims] In the manufacture of parts by powder injection molding in which a material obtained by mixing a binder with powder and pelletizing is molded in a mold, and then degreased and sintered, a part of the molded body is formed into a linear shape or a lattice shape. A method for manufacturing a component, comprising: after forming a groove, heating and pressing the surface of the formed body to cause plastic deformation so that the shape of the groove is narrower near the surface than inside, and then degreasing and sintering. 2. An orthodontic appliance having a rectangular plate having a linear groove on the surface and a projection for holding a wire on the back surface of the rectangular plate, wherein the shape of the groove is closer to the surface than to the inside. An orthodontic appliance characterized by being narrow. 3. A rectangular plate having a linear groove on the front surface and a projection for holding a wire on the back surface is formed in a mold using a material obtained by mixing a binder with powder and pelletizing. A method for manufacturing an orthodontic appliance, characterized in that the surface of a plate is heated and pressed to deform plastically so that the shape of the groove is narrower near the surface than inside, and then degreasing and sintering.