JPH0483801A - Hopper providing jig for adjusting powder flow - Google Patents

Abstract

PURPOSE:To discharge powder raw material without any segregation of components from outlet in a hopper and to improve the quality of a powder metallurgical product by setting the specific shape of a jig in the hopper of mixed powder raw material for powder metallurgy. CONSTITUTION:A storing chamber 14 for storing the raw material powder 1a and a supplying hole 15 opened at lower end part of the storing chamber are provided, and in the storing chamber above the supplying hole 15 in the hopper 1 for powder metallurgical raw material for supplying the raw material powder stored in the storing chamber to outer part from the supplying hole, the jig 2 having inclining surface 21 inclined to the horizontal plane, is set and an inclined angle of the inclining surface to the horizontal plane corresponds to the max. angle of repose during fluidizing the raw material powder. Therefore, by using this hopper 1, the raw material powder la in the storing chamber 14 is shifted downward under condition of holding the angle of repose with the jig 2 and efficiently supplied and, the shape variation on upper face according to the shifting is scarcely developed, and the development of segregated block as the conventional method can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hopper equipped with a jig for adjusting powder flow.

[Prior Art] Conventionally, as a raw material powder supply device used in powder metallurgy,
As shown in FIG. 7, the storage chamber 14 stores the raw material powder.
A, and a supply hole 15A that opens at the lower end of the storage chamber 14A.
and the raw material powder 1C stored in the storage chamber 14A.
A hopper 1A is known that supplies water to the outside from the supply hole 15A.

(Publication of Utility Model Application No. 63-192434) [Problems to be Solved by the Invention] The raw material powder 1C stored in the storage chamber 14A of the hopper 1A is supplied, for example, to a compression molding mold. When filling the space 9 formed by the lower punch 7 and die 8 by dropping, the raw material powder 1C is supplied from the supply hole 15A of the storage hopper 1A via the pipe 5 and the movable supply section 4. At this time, as the raw material powder 1C is consumed, the volume of the raw material powder 1C in the storage chamber 14A gradually decreases, and the top surface of the raw material powder 1C also decreases. The change in shape of the surface 10C of the raw material powder IC due to the positional movement of the raw material powder 1C in the storage chamber 14A changes from the almost horizontal chevron shape shown in FIG. 7 to the shape shown in FIGS. 8, 9, and 10. A concave portion 10b is formed in the center, and the shape transitions to a nearly vertical valley shape. In this case, the raw material powder 1C itself slips on the slope 10d inclined at an angle exceeding the normal angle of repose due to the deep recess 10b formed on the surface of the raw material powder 1C shown in FIG. As the angle increases, the sliding speed increases. Then, if the component composition of the raw material powder 1C during slipping is, for example, composed of minute graphite powder and iron powder, the two will be likely to separate. If the two are separated at the surface portion 10G of the raw material powder 1C and a segregated lump of only graphite powder or only iron powder is generated, it will be rolled up and mixed with the raw material powder 1C in other parts, so that the feed hole 15A Therefore, the raw material powder 1C having a uniform and preferable component composition is not supplied, and the raw material powder 1C containing the segregated lumps is transferred to the space between the lower punch 7 and the die 8 via the pipe 5 and the movable powder supply section 4. 9. When the raw material powder containing the segregated lumps is used as a raw material, compression molded, and sintered to produce a product, it is a defective product with defects in surface quality called porosity and avatars on the surface of the product. It's easy to become.

An object of the present invention is to prevent the raw material powder from moving in a hopper such that the composition of various components contained in the conventional raw material powder becomes unbalanced, and to improve the quality of molded products.

[Means for Solving the Problems] A hopper equipped with a jig for powder flow adjustment of the present invention includes a storage chamber for storing raw material powder, a supply hole opening at the lower end of the storage chamber, and a supply hole opening at the lower end of the storage chamber. A hopper that supplies the raw material powder stored in a storage chamber to the outside from the supply hole, wherein a jig having an inclined surface inclined with respect to a horizontal plane is disposed in the storage chamber above the supply hole, and the jig has an inclined surface inclined with respect to a horizontal plane. The inclination angle of the surface with respect to the horizontal plane corresponds to the maximum angle of repose of the raw material powder during flow.

The hopper includes a storage chamber, a supply section, and a jig arranged inside the storage chamber.

The greatest feature of the present invention is the jig installed inside the hopper.

The jig is characterized in that it has an inclined surface that is inclined with respect to the horizontal plane, and that the angle of inclination of this inclined surface with respect to the horizontal plane corresponds to the maximum angle of repose during the flow of the raw material powder.

The angle of repose is the angle at which a pile of powder can maintain a stable state without collapsing, and is expressed as the angle between the horizontal plane and the generatrix.

The angle of inclination of the inclined surface corresponding to the maximum angle of repose during flow of the jig varies depending on the type, shape, particle size, density, roughness of the powder surface, etc. of the raw powder, or the environmental conditions of use. It is preferable to set the most suitable value in advance through experiments using the raw material powder to be used.

The inclined surface of the jig can be set in various ways depending on the cross-sectional shape of the storage chamber in the horizontal direction, as long as it has an inclination corresponding to the angle of repose. For example, if the storage chamber is cut horizontally and the cross-sectional shape seen from above is a circle, square, triangle, rectangle, etc., the corresponding inclined surface may be a conical surface, a pyramidal surface, a triangular pyramidal surface, etc. A V-shaped arrangement of two plates with surfaces can be used.

[Operations and Effects of the Invention] According to the hopper equipped with the jig for powder flow adjustment of the present invention,
The angle of inclination of the inclined surface of the jig arranged in the storage chamber with respect to the horizontal plane corresponds to the maximum angle of repose during flow of the raw material powder. Therefore, when a certain amount of the raw material powder stored in the storage chamber is supplied to the outside from the supply hole as it is consumed, the raw material powder gradually settles and its upper surface position moves downward. At this time, the raw material powder is guided in the hopper by an inclined surface having an inclination angle corresponding to the maximum angle of repose during the flow of the jig, and settles while the angle of repose is maintained. Since no steep slope is formed on the raw material powder in the storage chamber, no slipping occurs, the movement speed is always stable, and there is no major change in shape due to the settling of the upper surface, which is almost horizontal in the shape of a mountain.

Therefore, it is possible to prevent the ratio of each component composition constituting the raw material powder from changing significantly depending on the position.

In other words, from the state where the raw material powder is loaded in the storage chamber of the hopper in an amount that almost fills the entire volume, it is sequentially supplied to the external use position, and at the time of transition to the state where all the raw material powder is consumed, the raw material powder in the storage chamber is There is no occurrence of depressions on the surface that occur during segregation, and raw material powder with a substantially uniform composition can always be supplied to the point of use. Therefore, molded products using this raw material powder have avatars and
Molded products with excellent quality can be obtained without changes in surface shape such as roughness.

[Example] An example of a hopper equipped with a powder flow adjustment jig according to the present invention will be described based on FIGS. 1 to 6.

As shown in FIG.
As a result, a storage chamber 14, a supply hole 15 opening at the lower end of the storage chamber 14, and an intake hole 16 opening at the upper end of the storage chamber 14 are formed inside. A jig 2 is arranged in the storage chamber 14. As shown in FIGS. 1 and 2, this jig 2 has an upper conical inclined surface 20 formed as a guide inclined surface on the upper part and with an apex angle R1 of 30° to 45°, and The maximum angle of repose during flow is 80', which was determined experimentally using raw material powder, and the horizontal plane
Since the inclination angle R2 with respect to 1 is 80°, the required apex angle R3 of the lower conical inclined surface 21 is 20'. This jig 2 is held by four ribs 23 connected to a peripheral wall 22 between an upper conical inclined surface 20 and a lower conical inclined surface 21. A ring-shaped rib 2 is provided on the other end side of this rib 23.
4 are connected. The ring-shaped rib 24 has four mounting holes 24a formed at approximately equal intervals, and is placed on the upper end flange 10a of the large diameter cylindrical portion 10 of the hopper 1 having the same diameter, and is used for bolts and nuts in the enclosure. Fixed by As a result, the lower conical inclined surface 21 of the jig 2 is held and fixed in the storage chamber 14 of the hopper 1 in a suspended state at approximately the center position.

Note that the jig 2 has a length such that the center portion P1 of the lower tip is disposed approximately at the center of the supply hole 15 of the storage chamber 14. The center portion P2 of the upper tip of the upper conical inclined surface 20 of the jig 2 protrudes above the intake port 16 of the storage chamber 14 and is located at the powder outlet portion 30 of the powder mixer 3. Further, a supply hole 15 provided in the small diameter cylindrical portion 12 of the hopper 1 is connected to the movable powder replenishing portion 4 by a flexible hose 5.

Further, between the hopper 1 and the movable powder replenishing section 4, there is a shutter 6 which is moved horizontally by a drive device of the enclosure for allowing or stopping the flow rate of the raw powder 1a.
is installed. Further, the movable powder replenishing section 4 is connected to an enclosure driving device so that it can move on a horizontal plane. As a result, the movable powder replenishing section 4 is configured to be able to fill a space 9 formed by the lower punch 7 and the die 8 by dropping a fixed amount of raw material powder into the space 9 .

According to the hopper 1 of this embodiment having the above configuration, graphite powder with an average particle size of approximately 5 μm prepared in advance and graphite powder with a particle size of 4 μm on average are prepared in advance.
Iron powder in the range of 0 to 180μ is mixed in a ratio of 1:99 by a powder mixer 3 as shown in FIG.
The raw material powder 1a is introduced into the storage chamber 14 using the upper conical inclined surface 20 of the jig 2 as a guide. Then, as shown in FIG. 3, the liquid is stored in the storage chamber 14 in a state where it occupies almost the entire volume. Thereafter, the shutter 6 is opened as necessary, and the powder is introduced from the supply hole 15 via the hose 5 into the movable powder replenishment section 4, and is also supplied to the space 9 formed by the lower punch 7 and die 8. . Along with this, the amount of raw material powder 1a stored in the storage chamber 14 decreases.

At this time, the upper surface shape 1b of the raw material powder 1a in the storage chamber 14 is such that the raw material powder 1a moving below it moves along the lower conical inclined surface 21 of the jig 2, so that the angle of repose is maintained. Because it can move in a horizontal direction, its flow is stable and it can maintain a nearly horizontal mountain shape. That is, the raw material powder 1a does not slip at a high moving speed and does not form local recesses or steep slopes, so that the upper surface shape 1b does not change. The raw material powder 1a in the storage chamber 14 is
The remaining amount is supplied in the above state after passing through the stages shown in FIGS. 5 and 6.

Therefore, according to the hopper 1 of this embodiment, the jig 2
As a result, the raw material powder 1a in the storage chamber 14 moves downward while maintaining its angle of repose, is efficiently supplied, and there is almost no change in the shape of the upper surface due to the movement, and the separation between The occurrence can be resolved.

As a result, after sintering the compact formed by receiving raw material powder from the hopper of this example, surface defects such as cavities and avatars may occur due to segregation of black smoke powder. I was able to resolve the issue.

[Brief explanation of drawings]

FIGS. 1 to 6 are explanatory diagrams illustrating a hopper equipped with a powder flow adjustment jig according to this embodiment. FIG. 1 is a longitudinal sectional view showing the entire main part. Figure 2 is the first
FIG. 3 is a plan view of the hopper in the figure. FIGS. 3 to 6 are schematic diagrams showing changes in the position of the upper surface shape as the raw material powder in the storage chamber is consumed. FIG. 7 is an explanatory diagram showing the entire feeder for raw material powder in a conventional hopper. FIGS. 8 to 10 are schematic diagrams showing changes in the position and shape of the upper surface shape as raw material powder is consumed in the same conventional hopper. 1... Hopper 1a... Raw material powder 10.
...Large diameter cylindrical part 11...Slanted cylindrical part 12...Small diameter cylindrical part 14...Storage 15...Supply hole
16...Intake hole 2...Jig
20... Upper conical inclined surface 21... Lower conical inclined surface
23... Rod-shaped rib 24-... Ring-shaped rib 24a
...Mounting hole R2...Inclination angle R3 equivalent to the maximum angle of repose during flow...Apex angle Patent applicant Toyota Motor Corporation

Claims (1)

[Claims] (1) A hopper comprising a storage chamber for storing raw material powder and a supply hole opening at the lower end of the storage chamber, and supplying the raw material powder stored in the storage chamber to the outside from the supply hole. A jig having an inclined surface inclined with respect to the horizontal plane is arranged in the storage chamber above the supply hole, and the angle of inclination of the inclined surface with respect to the horizontal plane corresponds to the maximum angle of repose of the raw material powder during flow. A hopper equipped with a jig for powder flow adjustment.