JPH09327798A - Feeder in powder molding equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniform the density of a green compact by providing a preparation member of the feed quantity of the raw material powder provided in the longitudinal direction of an opening part in a feeder body. SOLUTION: A feeder body 13 is moved straight in the longitudinal direction by a drive mechanism. A plurality of wires 18 which are preparation members are stretched in a center part in the longitudinal moving direction of the feeder body 13. The raw material powder from a tip opening part of a feed pipe 15 is impeded by the wires 18. The opening area of a lower opening part 13A in a cylindrical cavity is left unchanged on the right and left sides due to absence of the wires 18 with the longitudinal direction of the feeder body 13 as a reference, while the opening area is shut off by the part of the wire 18 in the longitudinal direction and reduced. That means, the difference between the right and left sides can be reduced. Thus, the filling density of the raw material powder can be unified.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a powder feeding feeder in a powder molding apparatus.

[0002]

2. Description of the Related Art In powder metallurgy, a raw material powder containing a metal as a main component is molded by a powder molding device into a green compact,
This green compact is heated in a sintering furnace to make a sintered body. here,
8 to 10 for an example of a conventional powder molding apparatus of this type
Will be described with reference to. The mold 1 of the powder molding apparatus includes a die 3 fixed to a die plate 2, a core rod 4, a lower punch 5, and an upper punch 7 held by an upper punch holder 6.
Are located in the die 3. The lower punch 5 has a cylindrical shape and is fitted between the die 3 and the core rod 4 from below. The upper punch 7 has a cylindrical shape and is fitted between the die 3 and the core rod 4 from above. Thus, a cavity 8 is formed between the die 3, the core rod 4, and the upper punch 7 and the lower punch 5. In the figure, 9 is a flange projecting from the lower part of the lower punch, 10 is a die fixing frame provided between the die 3 and the die plate 2, and 11 is a fixing frame provided between the die fixing frame 10 and the die plate 2.

On the other hand, the feeder 12 is connected to a feeder main body 13 having an opening 13A on its lower surface through a flexible supply pipe 15 for a hopper 14. The feeder body 13
Has an opening 13A on its lower surface, and this lower surface opening 13A is
It is larger than the outer circumference of the punches 5, 7. And
At the rear of the feeder body 13, a feeder lever 16
Is connected, and a drive mechanism (not shown) is connected to the feeder lever 16, and the feeder main body 13 is moved back and forth on the die plate 2 and the die 3 by the drive mechanism. The supply pipe 15 is connected to a supply pipe connection opening 17 provided on the upper side of the center of the rear portion of the feeder main body 13.

At the time of powder molding, the feeder body 13 is advanced to a position above the lower punch 5 in a state where the upper punch 7 is lifted and separated from the die 3 as shown in the figure. Further, the raw material powder is supplied from the hopper 14 storing the raw material powder into the feeder main body 13 via the supply pipe 15. At the same time, the feeder main body 13 reciprocates back and forth once or several times before and after the upwardly opened cavity 8 formed between the die 3, the core rod 4 and the lower punch 5, so that the inside of the cavity 8 is fed from the inside of the feeder body 13. The raw material powder is supplied to. When the filling of the raw material powder into the cavity 8 is completed, the feeder body 13 is retracted to move the cavity 8
Out of the upper position. Then, the upper punch 7 descends and is fitted between the die 3 and the core rod 4, and the die 3 rises, and the raw material powder is separated between the die 3 and the core rod 4 by the lower punch 5 and the upper punch 7. It is compressed and solidified to form a green compact. Thereafter, the upper punch 7 is raised, and the die 3 is further lowered, and the green compact is extracted from the die 3 by the lower punch 5. Further, as described above, as the feeder body 13 advances for powder supply, the compact is discharged by the feeder body 13. Such a molding cycle is repeated.

[0005]

In the feeder in the above-mentioned conventional powder molding apparatus, the raw material powder is moved in the forward and backward direction of the feeder main body 13 even if the cavity 8 has a substantially symmetrical front-back and left-right directions such as a cylindrical shape. On the other hand, a large amount of raw material powder is contained in the front-rear side b that spreads in the horizontal direction rather than the left-right side a that spreads in the vertical direction, which causes a problem that the density of the resulting cylindrical green compact becomes uneven. It was When a green compact with a non-uniform density is sintered in this way, the material that contracts during sintering will be deformed, and in the case of a sintered body that requires roundness and squareness, correct it. There must be.
However, the deformation of this sintered body is caused by the feeder main body 13
Occurs between the front and rear sides and the left and right sides of the cavity 8 with reference to the traveling direction of
In the case of a material having shrinkage, in the case of a cylindrical sintered body, the diameter in the front-back direction tends to be large and the diameter in the left-right direction tends to be small, and there is a limit to the correction. Therefore, when the powder is filled in the cavity 8, it is desired that the powder can be uniformly filled.

The difference in the filling amount of the raw material powder in the cavity 8 is caused by the forward and backward movement of the shoe box (feeder main body 13), which causes the powder to move forward and backward in the shoe box and become dense. It is expected that the powder pressure increases in the front-rear direction rather than the left-right direction in the shoe box. This tendency is particularly remarkable in the case of aluminum alloy powder having a low specific gravity.

An object of the present invention is to solve these problems and to provide a feeder in a powder molding apparatus for making a density of a green compact uniform and obtaining a sintered body having no quality problem.

[0008]

A feeder in a powder molding apparatus according to claim 1 of the present invention comprises a feeder main body having an opening on a lower surface and a supply pipe connected to an upper portion or a rear portion, and a feeder main body, the feeder main body. And a member for adjusting the supply amount of the raw material powder, which is provided in the front-rear direction of the opening in the inside. By adopting such a configuration,
The following effects can be obtained. That is,
When supplying the raw material powder into, for example, a cylindrical cavity formed in the mold, the feeder main body is advanced above the cavity on the die, and the raw material powder is supplied from the supply pipe into the feeder main body. At the same time, the feeder main body is reciprocated back and forth on the die, and the raw material powder is dropped into the cylindrical cavity from the inside of the feeder main body, and at this time, the opening of the lower surface of the feeder main body moves back and forth ( Since a member for adjusting the supply amount of the raw material powder is provided in the front-back direction, the supply amount of the raw material powder to the front-rear side that spreads in the lateral direction of the cylindrical cavity with respect to the front-back direction of the feeder main body is further suppressed. As a result, it is possible to make the filling amount of the raw material powder into the cylindrical cavity uniform.

Further, in the feeder in the powder molding apparatus of claim 2, the adjusting member is a plurality of wire rods, rods or plates. By adopting such a configuration,
With a simple structure, it is possible to suppress the supply amount to the front and rear sides that spread in the lateral direction of the cylindrical cavity. Further, the packing density can be adjusted depending on the shape and the kind of the raw material powder only by adjusting the intervals at which the plurality of wires or plates are installed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The configuration of an embodiment of the present invention will be described below with reference to FIG.
This will be described with reference to FIGS. As shown in FIG. 1, the mold 1 of the powder molding apparatus has basically the same configuration as that shown in FIGS. 8 and 9 described above, and the die 3 fixed to the die plate 2, the core rod 4, and the lower punch. 5 and an upper punch 7 held by an upper punch holder 6 to form a cavity 8 between the die 3, the core rod 4, and the upper punch 7 and the lower punch 5.

On the other hand, the feeder 12 has an opening 13A on the lower surface.
A hopper 14 is connected to a feeder main body 13 having a through a flexible supply pipe 15. Further, a feeder lever 16 is connected to the feeder main body 13, and a drive mechanism (not shown) is connected via the feeder lever 16. Thus, the feeder body
Numeral 13 is adapted to linearly move back and forth on the die plate 2 and the die 3 as indicated by an arrow by a driving mechanism. The supply pipe 15 is connected to a supply pipe connection opening 17 provided on the upper side of the center of the rear wall of the feeder main body 13 and inclined downward toward the front. As shown in FIGS. 2 and 3, the feeder main body 13 is provided with a plurality of wire rods 18 serving as adjusting members stretched in the longitudinal direction of the feeder main body 13 having the lower surface opening 13A, that is, in the center of the front-back direction. ing.

The operation of the above configuration will be described. During powder molding, the feeder body 13 is advanced to a position above the lower punch 5 on the die plate 2 and the die 3 with the upper punch 7 being lifted and separated from the die 3. When the feeder main body 13 moves forward, the die 3
And the core rod 4 is lowered, and the upper surfaces of the die 3 and the core rod 4 and the upper surface of the lower punch 5 are at the same height. Thereafter, the die 3 and the core rod 4 are raised.
A cavity 8 opened upward is formed between the die 3 and the core rod 4 and the lower punch 5. Then, the raw material powder P is supplied from the hopper 14 storing the raw material powder into the feeder main body 13 through the supply pipe 15. At the same time, as shown in FIG. 1, the feeder main body 13 is located on the die 2 and once or several times before and after the upward opening cavity 8 formed between the die 3 and the core rod 4 and the lower punch 5. Reciprocates twice. Thus, the feeder body
The raw material powder P drops into the cavity 8 from inside 13 and is supplied. At this time, the raw material powder P that has come out from the opening at the tip of the supply pipe 15 is blocked by the wire rod 18 in the opening 13A on the lower surface of the feeder body 13. Therefore, as shown in FIG. 3, the opening area of the lower surface opening 13A in the cavity 8 does not change because there is no wire rod 18 on the left and right sides a with respect to the front-back direction of the feeder main body 13, but on the front-back side b. It is cut off by 18 minutes and decreases. Moreover, since this wire 18 is stretched in the front-back direction of the lower surface opening 13A, this tendency does not change even if the feeder main body moves back and forth. Therefore,
Normally, the amount of the raw material powder P dropped on the front and rear sides b of the cylindrical cavity 8 in which the amount of the raw material powder P to be filled is large decreases.
Moreover, as shown in FIG. 4, since the raw material powder P falls while being distributed in the left-right direction by the wire 18, the amount of the raw material powder P dropped into the left and right sides a of the cylindrical cavity 8 should be slightly increased. You can As a result, the packing density of the raw material powder P between the front and rear sides b and the left and right sides a of the cylindrical cavity 8 can be made uniform.

As described in detail above, the feeder 12 in the powder molding apparatus of this embodiment has a feeder main body which moves forward and backward with an opening 13A on the lower surface and a supply pipe 15 connected to the rear.
13 and a plurality of wire rods 18, which are members for adjusting the supply amount of the raw material powder P, are stretched in the front-rear direction of the opening 13A in the feeder main body 13, so that the front-rear side b of the cylindrical cavity 8 is extended. Since the supply amount of the raw material powder P of the
And the packing density of the raw material powder P can be made uniform. It should be noted that, in the above-described embodiment, each wire 18 is detachable and its mounting position can be adjusted, so that it is possible to adjust the packing density depending on the shape of the cavity 8 and the kind of the raw material powder only by adjusting the interval and the number of the wire 18. It can be adjusted.

Next, a second embodiment of the present invention will be described with reference to FIGS. Since the feeder of the second embodiment has basically the same configuration as that of the first embodiment,
The same components are denoted by the same reference numerals, and detailed description thereof will be omitted. In the second embodiment, as the adjusting member, flat and narrow plate members 18A and 18B are vertically moved in the front-back direction of the lower surface opening 13A.
It is a stack of sheets. And this upper plate material 18
B is configured to slide laterally by a slide mechanism (not shown).

By adopting such a structure, for example, the plate materials 18A and 18B are usually set so as to be exactly overlapped with each other, so that the feeder main body 13 is made into the die 3
When the upper and lower cavities 8 formed between the die 3 and the lower punch 5 are moved back and forth once to several times, the raw material powder P discharged from the tip opening of the supply pipe 15 is discharged. , The plate material above the lower opening 13A of the feeder main body 13
The fall is hindered by 18B (Fig. 6 (a)). As a result, the amount of the raw material powder P dropped into the front-rear side b of the cylindrical cavity 8 in which the amount of the raw material powder P is normally increased decreases, so that the amount of the raw material powder P between the left and right sides a and the front-rear side b is reduced. Can reduce the difference between. Further, when the filling amount of the raw material powder P dropped on the front and rear sides b is still insufficient and is larger than that on the left and right sides a, the upper plate member 18B is replaced with the lower plate member 18B as shown in FIG. 6 (b). By sliding to a position exactly adjacent to 18A, a wide plate material may be configured to further prevent the raw material powder P from being dropped into the front-rear side b. Further, as shown in FIG. 6C, by sliding the upper plate member 18B to the middle of the lower plate members 18A, 18A, the opening area of the lower surface opening 13A on the front and rear side b of the cavity 8 is further reduced. As a result, the raw material powder P dropped on the front and rear sides b of the cylindrical cavity 8 can be reduced. in this way,
The filling amount of the raw material powder P can be adjusted in various modes.

The feeder in the powder molding apparatus of the present invention has been described above with reference to the accompanying drawings, but the present invention is not limited to the above-mentioned embodiment, and various modifications can be made. For example, as shown in FIG. 7, in the feeder of the first embodiment, by arranging the wire rods 18 densely in the central portion and sparsely in the lateral direction, the filling amount of the raw material powder P tends to increase. It may be configured such that the raw material powder P is less likely to be filled toward the part side. Further, in the first embodiment, the position of each wire 18 may be adjustable. Further, in each of the above-described embodiments, the wire rod 18 or the narrow plate members 18A and 18B are provided on the lower surface in the front-rear direction of the opening 13A.
18 or the like may be arranged to form a grid, and further, wires 18 or the like may be obliquely crossed to form a net. In addition, in the said 1st Example and 2nd Example,
Although the wire rod 18 or the flat and narrow plate members 18A and 18B are used, a rigid rod member may be used instead of these. Feeder in the powder molding apparatus of the present invention as described above
12 is effective for a powder molding apparatus for a sintered body having an opening at the center, and is particularly effective for a powder molding apparatus having a cylindrical cavity 8 as in each of the above embodiments. The cylindrical shape is not limited to a pure cylinder, but may be a shape having teeth or grooves on the inner peripheral surface or outer peripheral surface of a gear or the like.

[0017]

The feeder in the powder molding apparatus according to claim 1 of the present invention comprises a feeder main body having an opening on the lower surface and having a feed pipe connected to the upper or rear portion, and the opening in the feeder main body. Since it is provided with a member for adjusting the supply amount of the raw material powder provided in the front and rear direction of the part, the supply amount of the raw material powder to the front and rear sides that spread in the lateral direction of the cylindrical cavity with reference to the front and rear direction of the feeder body. Is more suppressed. As a result, it is possible to make the filling amount of the raw material powder into the cylindrical cavity uniform.

Further, in the feeder in the powder molding apparatus according to the second aspect, since the adjusting member is a plurality of wire rods, rods or plates, the front and rear sides of the cylindrical cavity spread with a simple structure. The supply amount to the side can be suppressed. Further, the packing density can be adjusted depending on the shape and the kind of the raw material powder only by adjusting the intervals at which the plurality of wires or plates are installed.

[Brief description of drawings]

FIG. 1 is an overall sectional view showing a usage state of a powder molding apparatus having a feeder according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view showing the feeder according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a feeder main body according to the first embodiment of the present invention.

FIG. 4 is a vertical sectional view showing a feeder main body according to the first embodiment of the present invention.

FIG. 5 is a partially cutaway perspective view showing a feeder according to a second embodiment of the present invention.

FIG. 6 is a vertical sectional view showing a feeder main body according to a second embodiment of the present invention, in which (a), (b) and (c) show different usage states.

FIG. 7 is a vertical sectional view showing a feeder main body according to a third embodiment of the present invention.

FIG. 8 is an overall sectional view showing a powder molding apparatus having a conventional feeder.

FIG. 9 is a cross-sectional view showing the conventional feeder.

FIG. 10 is a schematic view showing a relationship between a cavity and an opening in the conventional feeder.

[Explanation of symbols]

 1 Mold of powder molding machine 12 Feeder 13 Feeder body 13A Lower surface opening 18 Wire material (adjustment member) 18A Lower plate material (adjustment member) 18B Upper plate material (adjustment member)

Claims (2)

[Claims] 1. A feeder main body having an opening on its lower surface and having a supply pipe connected to an upper portion or a rear portion thereof, which moves back and forth, and a feed amount of raw material powder provided in the front and rear direction of the opening in the feeder main body. A feeder in a powder molding apparatus, comprising: an adjusting member. 2. The feeder in a powder molding apparatus according to claim 1, wherein the adjusting member is a plurality of wires, rods or plates.