JPS62177102A - Production of powder molding - Google Patents

Abstract

PURPOSE:To easily manufacture a powder molding having a stepped part by using dies combined with an outer punch which constitutes a frame shape and has a stepped part to form the stepped part of the molding in the inside wall part and an upper punch and lower punch to be inserted into the outside punch. CONSTITUTION:The dies are constituted of the outside punch 12 which constitutes the frame shape and has the stepped part 13 to form the stepped part of the molding in the inside wall part and the upper punch 14 and lower punch 15 to be inserted into the outside punch 12. The upper punch 14 is raised and is removed from the inside space part of the outside punch 12. Metallic powder 16 made of the prescribed compsn. is packed into the inside space part. The upper punch 14 is lowered and is inserted into the inside space part of the outside punch 12 to pressurize the metallic powder 16. The powder molding having the stepped part in both side parts in the space parts enclosed with the respective punches 12, 14, 15 is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a powder molded article, which involves molding a powder molded article having a stepped portion.

[Technical background of the invention and its problems]

In the powder metallurgy method, a right-angled step 2 is formed as shown in Figure 2.
Conventionally, when producing a product 1 having a stepped portion 2, it is difficult to press powder in the molding step to form a powder molded product having the stepped portion 2. As shown in FIG. 2
A powder molded product 3 having a shape including
We are trying to form a

In other words, in order to mold a powder molded product having a right-angled step, a method has been attempted that uses a mold equipped with a thin special punch for forming the right-angled step, but since this special punch is thin, There was a risk of damage during molding, so it was not put into practical use.

Therefore, in the past, special machining was required to form the stepped portion after sintering, resulting in a large number of steps and poor productivity.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and has an object to easily and reasonably mold a powder molded product having a stepped portion, thereby increasing productivity when manufacturing a part having a stepped portion by a powder metallurgy method. The object of the present invention is to provide a method for manufacturing powder molded products that can be used.

[Summary of the invention]

In the method for producing a powder molded article of the present invention, when pressurizing powder to mold a molded article having a stepped portion, the molded article has a frame shape and has a stepped portion on an inner wall portion for forming the stepped portion of the molded article. Using a mold consisting of a combination of an outer punch and an upper punch and a lower punch inserted into the outer punch, the space surrounded by the lower punches of this mold is filled with powder and pressurized. This feature prevents damage to the punch that forms the stepped portion during molding.

[Embodiments of the invention]

An embodiment of the present invention illustrated in the drawings will be described below.

In this embodiment, the present invention is applied to the case where an article 1 having right-angled step portions 2, 2 on both sides is manufactured by powder metallurgy as shown in FIG. Molding a powder molded product using the mold shown in the figure 0 In the figure, 11 is a die;
Reference numeral 12 denotes an outer punch, and the outer punch 12 is provided so that it can be raised and lowered from the hole 11a of the die 11.The outer punch 12 has a frame shape with an inner space corresponding to the outer shape of the article 1. On both sides of the inner wall thereof, right-angled forming steps 13, 13 for forming the right-angled steps 2.2 of the article 1 are formed corresponding to the right-angled steps 2, 2. 014 is an upper punch, and this upper punch 14 is movable up and down so that it can be inserted into and extracted from the upper opening of the inner space of the outer punch 12. Reference numeral 15 denotes a lower punch, and this lower punch 15 is provided in a portion sandwiched between the stepped portions 13° 13 of the inner space of the outer punch 12 so as to be movable up and down.

By combining the outer punch 12, the upper punch 14, and the lower punch 15, each of these punches 12,
A space surrounded by 14 and 15 for molding a powder molded product is formed.

Next, a method for molding a powder molded product using the mold having the above configuration will be described. First, the upper punch 14 is raised and extracted from the inner space of the outer punch 12, and material powder (metal powder) 16 of a predetermined composition is filled into the inner space.Then, the upper punch 14 is lowered and pulled out. Outside punch 12
By pressurizing the material powder 16 by inserting it into the inner space of the punches 12, 14, and 15, a second
A powder molded article is molded which has right-angled steps 2.2 on the same sides as the article 1 shown in the figure. In this case, the right-angled step 2.2 of the powder molding is precisely shaped by the forming step of the outer punch 12. After the molding is completed, the upper punch 14 is raised, the outer punch 12 is lowered, and the lower punch 15 is raised to extract the powder molded product from the mold.

However, in this method of molding a powder molded product, a frame-shaped outer punch 12 integrally formed with a molding step 13 for forming a right-angled step of the powder molded product is used. The forming step I3 of the outer punch 12 is not damaged at times. This makes it possible to mold a powder molded product having a step at right angles.

The powder molded article can then be sintered to obtain an article 1 having a right-angled step 2.2 of sintered article. That is, since the sintered product has already been molded with the right-angled step 2.2, there is no need to perform any special machining to form this step on the sintered product.

Note that the stepped portion formed on the powder molded product is not limited to a right angle, but may be inclined.

[Effects of the Invention] As explained above, according to the method for producing a powder molded product of the present invention, a powder molded product having a stepped portion can be easily molded without damaging the mold, and thereby the stepped portion can be easily molded without damaging the mold. 0 that can improve production efficiency when manufacturing products with

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a mold used in an embodiment of the manufacturing method of the present invention, Fig. 2 is a perspective view showing an article having a step at right angles, and Fig. 3 is a powder molded by a conventional method. 011... Die, 12... Outer punch, 13... Molding installation part, 14... Upper bunch, 15... It is a front view showing the molded product.
... Shimono-kunchi. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] When pressurizing powder to mold a molded product having a stepped portion, an outer punch is formed into a frame shape and has a stepped portion on an inner wall portion for forming the stepped portion of the molded product, and a punch is inserted into the inside of this outer punch. A method for manufacturing a powder molded product, characterized in that a mold formed by combining an upper punch and a lower punch is used, and a space surrounded by the punches of the mold is filled with powder and pressurized.