JPH06210496A - Powder feeding device and method - Google Patents

Abstract

(57) [Summary] [Purpose] In powder metallurgy, the raw material powder is accurately filled from the shoe box to the cavity according to various conditions such as the cavity. [Structure] The shoe box 32 has a supply pipe 34 connected to the rear portion thereof and moves back and forth on a die 23 of a mold 21. A movable guide plate 41 is provided in the shoe box 32 so that the position and angle in the front-rear direction can be adjusted. At the time of powder feeding, the raw material powder that has entered the shoe box 32 from the supply pipe 34 is mainly the movable guide plate 41.
Collects in the rear of and then falls into the cavity. [Effect] Therefore, it is possible to adjust the position and angle of the movable guide plate 41 in the front-rear direction so that the raw material powder is accurately filled in the cavity. Inclining the movable guide plate 41 in the downward direction is effective because the movable guide plate 41 pushes the raw material powder into the cavity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder feeding apparatus and a powder feeding method used for feeding raw material powder into a die in powder metallurgy.

[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 and sintered in a sintering furnace. Here, an example of a conventional powder molding apparatus of this type will be described with reference to FIG. The die 1 is composed of 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, and forms a cylindrical green compact 8. is there. The core rod 4 is located inside the die 3. Both lower punches 5 have a cylindrical shape,
The die 3 and the core rod 4 are fitted from below. The upper punch 7 has a tubular shape,
The die 3 and the core rod 4 are fitted from above. Thus, the cavity 9 is formed between the die 3, the core rod 4, and the punches 5 and 7. On the other hand, in the powder feeding device 11, a hopper 13 is connected to a shoe box 12 having an open lower surface via a flexible supply pipe 14, and a feeder lever is attached to the shoe box 12 although not shown. A drive mechanism is connected via. Thus, the shoe box 12 is linearly moved back and forth on the die plate 2 and the die 3 by the drive of the drive mechanism, as indicated by the arrow. The supply pipe 14 is connected to the upper side of the center of the rear part of the shoe box 12 so as to face downward.

At the time of powder molding, the shoe box 12 is advanced to a position above the lower punch 5 with the upper punch 7 being lifted and separated from the die 3. When the shoe box 12 moves forward, the die 3 is descending, and the upper surface of the die 3 and the upper surface of the lower punch 5 are at the same height. A cavity 9 that opens upward is formed between the core rod 4 and the lower punch 5. In addition, the shoe box 12 from the hopper 13 that stores the raw material powder through the supply pipe 14.
Raw material powder is supplied therein. At the same time, the shoe box 12 reciprocates once or several times before and after the cavity 9 to supply the raw material powder from the inside of the shoe box 12 into the cavity 9. When the filling of the raw material powder into the cavity 9 is completed, the shoe box 12 is retracted to move the cavity 9
Out of the upper position. Then, the descending upper punch 7 is fitted between the die 3 and the core rod 4, and the die 3 descends, and the lower punch 5 and the upper punch 7 form a raw material powder between the die 3 and the core rod 4. Are compressed and hardened to form a green compact 8. afterwards,
As the upper punch 7 rises, the die 3 further descends, and the lower punch 5 extracts the green compact 8 from the die 3. In addition, as the shoe box 12 advances for powder feeding as described above, this shoe box 12
The powder compact 8 is dispensed by 12. The above molding cycle is repeated.

[0004]

By the way, in a certain shoe box 12, the size and shape of the cavity 9 or the shoe box used for discharging the powder compact 8 is used.
Due to various conditions such as dimensional restrictions on 12, it is not always possible to accurately fill the raw material powder from the shoe box 12 into the cavity 9, and the filling may become insufficient or uneven.

The present invention is intended to solve such a problem, and it is an object of the present invention to provide a powder feeding device capable of accurately filling raw material powder from a shoe box into a cavity according to various conditions such as a cavity. To aim.

[0006]

In order to achieve the above-mentioned object, a powder feeding apparatus according to a first aspect of the present invention includes a shoe box which has an opening on a lower surface thereof and which is connected to a supply pipe at a rear portion thereof, and which moves back and forth.
The shoe box is provided with a movable guide plate provided at an intermediate portion in the front-rear direction so as to be rotatable forward and backward.

In the powder feeding method according to the second aspect of the present invention, a shoe box having an opening on the lower surface and having a supply pipe connected to the rear portion, and a shoe box that moves forward and backward, and a forward and backward rotation in an intermediate portion in the longitudinal direction in the shoe box. A shoebox is provided in a cavity formed in the die by moving the shoebox back and forth on the die of the die of the powder molding apparatus using a powder feeding device provided with a movable guide plate that is movable. When feeding the raw material powder from the above, when the shoe box moves forward, the movable guide plate is inclined with the directionality to move forward, and when the movable guide plate moves backward with the shoe box above the cavity, the movable guide plate starts at the beginning. The vertical direction, and when the movable guide plate retracts above the rear end of the cavity, the movable guide plate is inclined with a directionality in which it descends forward. That.

[0008]

In the powder feeder of the first aspect of the invention, when the raw material powder is supplied into the cavity formed in the die of the powder molding apparatus, the shoe box is advanced on the die to a position above the cavity and supplied. The raw material powder is supplied into the shoe box through a pipe, and the raw material powder is dropped into the cavity from the inside of the shoe box while the shoe box is moved back and forth to fill the cavity. At this time, the raw material powder mainly enters behind the movable guide plate in the shoe box in which the supply pipe is connected to the rear portion, and the raw material powder falls into the cavity from there. Therefore, by rotating the movable guide plate back and forth in advance and adjusting the angle of the movable guide plate, it is possible to accurately fill the raw material powder from the shoe box into the cavity according to various conditions such as the cavity. Become. Since the raw material powder is collected mainly behind the movable guide plate in the shoe box, if the movable guide plate is inclined with a direction to descend toward the front, the movable guide plate can be retracted when the shoe box is retracted. Generates a force that pushes the raw material powder toward the lower cavity, and the raw material powder can be filled into the cavity so as to ensure a sufficient density.

Further, in the powder feeding method according to the second aspect of the present invention, when the shoe box is moved forward, the movable guide plate is tilted with a directionality in which the movable guide plate descends forward. When retreating the upper position of, the movable guide plate is first made vertical, and the raw material powder on the rear side of the movable guide plate in the shoe box is pushed backward to fill the cavity. This ensures that the raw material powder can be filled into the cavity so as to ensure a sufficient density. Originally, the back end of the cavity tends to be clogged with a large amount of raw material powder, but when the movable guide plate retracts above the rear end of the cavity, the movable guide plate is inclined with a direction in which it falls forward. By doing so, the filling of the raw material powder into the rear end of the cavity is suppressed, and the raw material powder can be uniformly filled in the entire cavity.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the mold 21 of the powder molding apparatus is the same as the conventional one, and includes a die 23 fixed to a die plate 22, a core rod 24, a lower punch 25, and an upper punch held by an upper punch holder 26. 27, and for forming a cylindrical green compact 28, a die 23, a core rod 24 and both punches 25, 27 are formed.
A cavity 29 is formed between the cavity 29 and.

On the other hand, in the powder feeding device 31, a hopper 33 is connected to a shoe box 32 having an opened lower surface through a flexible supply pipe 34. Further, drive pins 35 are respectively screwed to the lower left and right side surfaces of the shoe box 32, and feeder levers (not shown) of a drive mechanism are engaged with the drive pins 35. Thus, the shoe box 32 is linearly moved back and forth on the die plate 22 and the die 23 as indicated by the arrow by the drive of the drive mechanism. The supply pipe 34 is connected to a pipe connecting portion 36 provided on the upper side of the center of the rear portion of the shoe box 32 and inclined in a direction descending toward the front.
A movable guide plate 41 is provided in the center of the shoe box 32 in the front-rear direction so as to partition the inside of the shoe box 32 into substantially front and rear. This movable guide plate
A screw-shaped support shaft 42 is provided coaxially in the upper and lower side surfaces of 41 on the left and right sides so as to be coaxial with the left-right direction. on the other hand,
On the left and right side surfaces of the shoe box 32, long holes 43 extending in the front-rear direction are formed. And these long holes 43
A support shaft 42 of the movable guide plate 41 is rotatably and rotatably inserted thereinto, and a wing nut 44 is screwed onto the support shaft 42 outside the left and right side surfaces of the shoe box 32. In this way, the movable guide plate 36 can be moved back and forth with the wing nut 44 loosened as shown by the arrow, and the support shaft 42 can be moved.
The wing nut can be rotated around its center to adjust its longitudinal position and angle.
By tightening 44, it can be fixed at a predetermined position and angle.

Next, the operation of the above configuration will be described. At the time of powder molding, with the upper punch 27 raised and separated from the die 23, the shoe box 32 is moved to a position above the lower punch 25 on the die plate 22 and the die 23.
To move forward. When the shoe box 32 is moving forward,
The die 23 is descending, and the upper surface of this die 23 and the upper surface of the lower punch 25 are at the same height, but after that, the die 23 rises and moves upward between the die 23, the core rod 24 and the lower punch 25. A cavity 29 having an opening is formed. Then, from the hopper 33 in which the raw material powder is charged and stored, the supply pipe
Raw material powder is supplied into the shoe box 32 via 34. Along with this, the shoe box 32 reciprocates once or several times before and after the cavity 29,
The raw material powder drops from the inside 32 into the cavity 29 and is supplied. When the filling of the raw material powder into the cavity 29 is completed,
The shoe box 32 retracts and is disengaged from the position above the cavity 29. Then, the descending upper punch 27 is die 23
And the core rod 24, the die 23 descends, and the raw material powder is compressed and solidified by the lower punch 25 and the upper punch 27 between the die 23 and the core rod 24 to be compacted. 28 can be done. Thereafter, the upper punch 27 rises and the die 23 further descends, so that the lower punch 25 extracts the green compact 28 from the die 23. In addition, the shoe box for powdering as described above
The powder compact 28 is discharged by the shoe box 32 as the powder 32 moves forward. The above molding cycle is repeated.

By the way, at the time of the above-mentioned powder feeding, the inside of the shoe box 32 is partitioned by the movable guide plate 41 substantially in the front and rear, and the supply pipe 34 is connected to the rear portion of the shoe box 32. The raw powder coming out of the tube 34 is
Mainly inside the shoe box 32, it enters behind the movable guide plate 41, and then falls into the cavity 29 from there. Therefore, according to various conditions such as the size and shape of the cavity 29, or dimensional constraints on the shoe box 32, the position and angle of the movable guide plate 41 in the front-rear direction are appropriately adjusted in advance, so that the shoe box 32 From this, the raw material powder can be efficiently and surely filled into the cavity 28. Further, since the raw material powder is mainly collected in the shoe box 32 behind the movable guide plate 41, if the movable guide plate 41 is inclined with a direction in which it descends toward the front as shown in the figure, the shoe When the box 32 is retracted, the movable guide plate 36 generates a force that pushes the raw material powder toward the lower cavity 29, and the cavity 29 can be filled with the raw material powder with a sufficient density.

Next, a second embodiment of the present invention will be described in detail with reference to FIGS. 4 and 5. The parts corresponding to those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted. In this second embodiment,
The mold 21 of the powder molding apparatus is for simultaneously molding two cylindrical green compacts. For that, the core rod
24, lower punch 25, and upper punch (not shown) are provided in each set, and a pair of left and right cavities 29 are formed inside the mold 21. Also,
In the powder feeding device 31, the inside of the shoe box 32 is partitioned by a partition wall 51 into a pair of left and right compartments 52. These compartments 52 are respectively two cavities 29 of the mold 21.
Are to be dealt with separately. In addition, the shoe box 32
A pair of pipe connecting portions 36 that open to both compartments 52 are provided on the upper rear side. These pipe connecting portions 36 are inclined in a direction that descends toward the front. Further, flexible supply pipes 34 are connected to these pipe connecting portions 36, respectively, and these supply pipes 34 are connected to a common hopper 33 via a three-pronged joint 53. Further, since the inside of the shoe box 32 is partitioned into the two compartments 52 in this way, the movable guide plates 41 similar to those in the first embodiment are provided in the compartments 52, respectively. Both movable guide plates 41
The support shaft 42 projecting from the side surface of the partition wall 51 is pivotally supported by a long hole 43 formed in the partition wall 51. Further, the two movable guide plates 41 in the compartments 52 of the shoe box 32 are
The position and angle can be adjusted independently.

Then, at the time of powder feeding in powder molding, the hopper
Two compartments defined by the partition wall 51 in the shoe box 32 from the 33 through the three-pronged joint 53 and the two supply pipes 34.
The raw material powder is supplied to each of the 52 and the molds 21
The raw material powder falls into each of the two cavities 29.
As a result, both cavities 29 are uniformly filled with the raw material powder. Therefore, when simultaneously molding two green compacts with the die 21, a green compact having a stable density can be obtained. The operational effects obtained by the movable guide plate 41 for the respective cavities 29 are the same as those in the first embodiment.

Next, a third embodiment of the present invention will be described with reference to FIGS. 6 and 7. In this third embodiment,
The movable guide plate 41 is automatically swung in conjunction with the forward and backward movement of the shoe box 32 during powder feeding. More specifically, as shown in FIG. 6A, the shoe box 32
When the movable guide plate 41 is inclined forward with a directionality of descending forward, as shown in FIG. 6B, when the movable guide plate 41 moves backward with the shoe box 32 above the cavity 29, First, the movable guide plate 41 is rotated counterclockwise in the drawing to be vertical, and then when the movable guide plate 41 retracts above the rear end portion of the cavity 29, the movable guide plate 41 is rotated clockwise. It is rotated and tilted with the directionality of descending forward. In particular, when the movable guide plate 41 is rotated counterclockwise in the drawing, after the shoe box 32 that has been moved forward is stopped, the movable guide plate 41 is rotated at this stop position and then the shoe box 32 is retracted. May be, shoe box
The movable guide plate 41 may be rotated while the 32 is retracted.
A movable guide plate that is linked to the forward and backward movement of the shoe box 32.
To swing 41, for example, power may be taken from the upper ram driving rotary shaft to which the upper punch of the powder molding apparatus is attached, and this may be transmitted to the support shaft 42 of the movable guide plate 41 via a cam or the like. . FIG. 7 shows changes in the height of the upper surface of the die 23, the upper surface of the lower punch 25 and the lower surface of the upper punch 27 in one cycle of powder molding (a), and the change in the tip position of the shoe box 32 (b). The change in the angle of the movable guide plate 41 is shown in (c). In these diagrams, the horizontal axis is common and is the rotation angle of the drive rotation shaft of the powder molding apparatus. Further, in (b), the alternate long and short dash line indicates the center position of the die 23, that is, the center position of the cavity 29. Further, in (c), the angle is shown with the clockwise direction in FIG. 6 as the positive direction. The operation other than the movable guide plate 41 is as shown in FIG. 7 also in the first embodiment and the like.

At the time of powder feeding, as in the first embodiment, etc., the movable guide plate is mainly moved in the shoe box 32.
Although the raw material powder enters the rear of 41, as described above, when the shoe box 32 is moved forward, the movable guide plate 41 is tilted with a directionality in which the movable guide plate 41 descends toward the front, and thereafter, together with the shoe box 32, the movable guide plate. When the movable guide plate 41 is rotated in the counterclockwise direction to be vertical when 41 moves backward from the upper position of the cavity 29, the raw material powder on the rear side of the movable guide plate 41 in the shoe box 32 becomes Movable guide plate
It is pushed backward by 41 and filled in the cavity 29 while being raised. As a result, a larger amount of raw material powder can be reliably filled in the cavity 29. By the way, originally, the rear end of the cavity 29 is likely to be clogged with a large amount of the raw material powder, and the density of the green compact 28 is likely to increase there, but when the movable guide plate 41 retreats from the upper position of the rear end of the cavity 29. By rotating the movable guide plate 41 in the clockwise direction and inclining the movable guide plate 41 in the downward direction, the filling of the raw material powder into the rear end of the cavity 29 is suppressed. As a result, the raw material powder can be uniformly filled in the entire cavity 29. Thus, according to the configuration of the third embodiment, a sufficient amount of the raw material powder can be uniformly filled in the cavity 29, and the green compact 28 having a sufficiently high and uniform density can be obtained.

The present invention is not limited to the above embodiment, but various modifications can be made. For example,
The mold 21 of the embodiment has the core rod 24 in order to mold a cylindrical green compact, but the present invention is of course also applied to a powder molding apparatus having no core rod in the mold. it can.

[0019]

According to the invention of claim 1, the movable guide plate is provided rotatably in the front-rear direction in the front-rear direction intermediate portion in the forward-backward moving shoe box having the supply pipe connected to the rear portion. By properly adjusting the angle of the movable guide plate, the raw material powder can be accurately filled from the shoe box into the cavity according to various conditions such as the cavity.

According to the second aspect of the present invention, when the shoe box is moved forward, the movable guide plate is inclined with a directionality of descending forward, and the movable guide plate is retracted from the upper position of the cavity together with the shoe box. Sometimes, first, the movable guide plate is made vertical, and when the movable guide plate is retracted above the rear end of the cavity, the movable guide plate is inclined with the directionality to move forward. It is possible to surely fill the cavity so as to have a sufficient density, prevent the rear end portion of the cavity from being clogged with too much raw material powder, and uniformly fill the raw material powder throughout the cavity.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a mold and a powder feeding device showing a first embodiment of the present invention.

FIG. 2 is a perspective view of the same shoe box.

FIG. 3 is an enlarged cross-sectional view of the same shoe box.

FIG. 4 is a cross-sectional view of a mold and a powder feeding device showing a second embodiment of the present invention.

FIG. 5 is a perspective view of the same shoe box.

FIG. 6 is an explanatory view of the operation of the movable guide plate showing the third embodiment of the present invention.

FIG. 7 is a diagram showing the operation of the same mold, shoe box and movable guide plate.

FIG. 8 is a cross-sectional view of a mold and a powder feeding device showing a conventional example.

[Explanation of symbols]

 21 mold 23 die 29 cavity 31 powder feeder 32 shoe box 34 supply pipe 41 movable guide plate

Claims (2)

[Claims] 1. A shoe box, which has an opening on the lower surface and which is connected to a supply pipe at the rear, and which moves back and forth, and a movable guide plate, which is rotatably provided back and forth at an intermediate portion in the front-rear direction in the shoe box. A powder feeding device characterized by being provided. 2. The powder feeding device according to claim 1, wherein the shoe box is moved back and forth on a die of a mold of a powder molding apparatus, so that the raw material is fed from the shoe box into a cavity formed in the mold. When supplying the powder, when the shoe box moves forward, the movable guide plate is inclined with a directionality that moves downward toward the front, and when the movable guide plate retracts above the cavity along with the shoe box,
A powder feeding method, characterized in that the movable guide plate is made vertical at the beginning, and when the movable guide plate is retracted above the rear end of the cavity, the movable guide plate is inclined with a direction in which the movable guide plate descends forward.