JP2000234105A - Powder rolling roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder rolling roll which is capable of obtaining a green compact which is uniform in density distribution in the width direction even when end portions of the green compact are not slit. SOLUTION: In a powder rolling roll provided with a pair of rolls to roll a metal powder, a projecting part 3 is formed in one roll of a pair of rolls, and a groove part 4 is formed in the other roll. In the powder rolling roll to be used, a tapered part 6 is formed on both ends of the projecting part and the groove part, and the taper angle α of the projecting part is made smaller than the taper angle β of the groove part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder rolling roll for forming a material of metal powder into a green compact by rolling.

[0002]

2. Description of the Related Art There is a powder rolling method as a method for producing a metal plate from metal powder. In this method, metal powder is continuously rolled to form a band-shaped green compact, which is introduced into a furnace for sintering, and then rolling and sintering (annealing) are repeated.
A pair of flat rolling rolls without grooving or the like are used for the rolling mill. In this method, when the width of the green compact formed by rolling is increased, the end of the green compact is deformed in a wavy shape, or the central portion is loosened and cracks are formed. It is taken into consideration that the flow rate, spacing, and fluidity of the metal powder to be rolled are appropriate.

[0003]

The conventional powder rolling roll has the following problems.

[0004] In order to prevent the periphery of the green compact from being deformed in a wavy manner or to be loosened at the center and not to be cracked, the diameter and interval of the rolling roll used and the fluidity of the metal powder to be rolled are taken into consideration. Nevertheless, the density is lower than that near the center of the green compact because the binding force of the powder is reduced (the powder escapes) at the end of the green compact during rolling. If sintering and rolling are performed in this state, cracks may occur at the ends and the compact may be broken.

Conventionally, the low-density portion at the end is removed by slitting. However, there has been a problem that the yield of the material is low.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned disadvantages of the prior art and to obtain a green compact having a uniform density distribution in the width direction without slitting the end of the green compact. Is to provide.

[0007]

According to the present invention, there is provided a powder rolling roll comprising a pair of rolls for rolling metal powder, wherein the pair of rolls have a projection on one of the rolls. And the other roll is provided with a groove.

[0008] Further, tapered portions are provided at both ends of the projection and the groove, respectively, and the taper angle α of the projection is formed smaller than the taper angle β of the groove.

[0009]

FIG. 1 is a partially detailed sectional view showing a first embodiment of a powder rolling roll according to the present invention. 1 is a projection roll, 2 is a groove roll, 3 is a projection, 4 is a groove, 5 is a green compact, 6 is a projection taper, 7 is a groove taper, 8 is a projection roll flat, and 9 is a groove roll flat. It is. Α is a projection taper angle, β is a groove taper angle, and α <β.

A pair of rolls, that is, a protrusion roll 1 and a groove roll 2 are provided with a protrusion 3 and a groove 4, respectively. A protrusion taper 6 and a groove taper 7 are provided at both ends of the protrusion 3 and the groove 4, respectively. The taper angle of the protrusion taper 6 is indicated by a protrusion taper angle α, and the taper angle of the groove taper 7 is indicated by a groove taper angle β.

The reason why the projections 3 and the grooves 4 and the tapered portions 6 and 7 are provided on the powder rolling roll is as follows. The combination of the projection 3 of the projection roll 1 and the groove 4 of the groove roll 2 can prevent a decrease in powder binding force (escape of powder) at the end of the green compact 5 and reduce the density. Can be prevented. At this time, groove taper portions 7 are provided at both ends of the groove 4 so that the density 5 and the thickness of the green compact 5 do not make it difficult for the green compact 5 to peel off from the groove 4. Further, when the use time of the rolling roll is prolonged, the protrusions 3 of the protrusion roll 1 may be cracked or broken due to fatigue or the like. Therefore, the protrusion taper portions 6 are also provided at both ends of the protrusion portion 3.
Is provided.

A result of supplying copper powder between the projection roll 1 and the groove roll 2 to form a green compact 5 will be described below. In the present embodiment, the diameter of the projection 3 and the groove 4 was set to 200 mm so that the thickness of the green compact 5 was 1 mm and the peripheral speed of the projection roll 1 and the groove roll 2 was matched. The height of the projection 3 and the depth of the groove 4 were 5 mm and 3 mm, respectively. As a result, a green compact 5 having a thickness of 1 mm is obtained, and the flat roll portion 8 and the flat roll portion 9 do not kiss each other. Further, in the groove taper portions 7 at both ends of the groove portion 4, a groove taper angle β was formed so that the green compact 5 was easily peeled from the groove portion 4. Furthermore, in the long-term work, cracks and hangs are liable to enter from the end of the projection 3,
Since the projection roll 1 was damaged, the taper angles α of the projection tapered portions 6 at both ends were formed. This makes it possible to continuously obtain green sheets (compacts) uniformly compacted in the grooves 4.

The projection taper angle α is set smaller than the groove taper angle β. This is because if the width of the rolled surface is made substantially the same between the projection roll 1 and the groove roll 2, when α> β,
This is because the maximum width of the projection becomes larger than the maximum width of the groove 4, and the amount of reduction of the projection roll 1 or the groove roll 2 is limited, which is not preferable.

FIG. 2 is an explanatory sectional view showing a second embodiment of the powder rolling roll of the present invention. Reference numeral 10 denotes a projection split roll, 11 denotes a groove split roll, 12 denotes a spacer, 13 denotes a green compact, 14 denotes a fastening nut, and 15 denotes a roll shaft.

When a combination of a projection roll and a groove roll is used, the rolls are likely to receive a thrust load on the side of the projection or the groove due to an imbalance between the right and left rolls, and the roll is likely to be damaged. Further, once the roll is processed, it is impossible to change the width of the groove and the like. Therefore, as shown in FIG. 2, the roll was made into a split roll so that the metal powder could be compacted. This compacting is performed by the projection split rolls 10 and the groove split rolls 11. The entire length of the roll can be arbitrarily adjusted by the spacer 12. The projection split roll 10 and the spacers 12 on both sides are fixed by a tightening nut 14 provided on the roll shaft 15. Similarly, the groove split roll 11 and the spacers 12 on both sides are fixed by a tightening nut 14 provided on the roll shaft 15. For this reason, even if the width of the compact to be compacted changes, the change is easy.

[0016]

According to the powder rolling roll of the present invention, a projection is provided on one roll and a groove is provided on the other roll, and a tapered portion is provided on both ends of the projection and the groove. It is possible to prevent a decrease in the binding force of the powder and to form a uniform green compact in the width direction.

[Brief description of the drawings]

FIG. 1 is a partially detailed sectional view showing a first embodiment of a powder rolling roll of the present invention.

FIG. 2 is an explanatory sectional view showing a second embodiment of the powder rolling roll of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Protrusion roll 2 Groove roll 3 Protrusion part 4 Groove part 5 Green compact 6 Protrusion taper part 7 Groove taper part 8 Protrusion roll flat part 9 Groove roll flat part α Protrusion taper angle β Groove taper angle 10 Dividing roll for projection 11 Groove division Roll 12 Spacer 13 Green compact 14 Tightening nut 15 Roll shaft

Claims (2)

[Claims] 1. A powder rolling roll comprising a pair of rolls for rolling metal powder, said pair of rolls having a projection provided on one roll and a groove provided on the other roll. A powder rolling roll, comprising: 2. A taper portion is provided at both ends of the protrusion and the groove, and a taper angle α of the protrusion is provided.
2. The powder rolling roll according to claim 1, wherein the groove is formed to be smaller than a taper angle β of the groove.