JP2009214135A - Powder feeder device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a powder feeder device which can stably fill a material powder into a die cavity, and furthermore has a simple constitution compared with a conventional device. <P>SOLUTION: The powder feeder device 10 is provided with a cylinder device 16. A powder supply pipe 12 is formed in the upper part of the rear end of a feeder box 11. A feeder box side ventilating port 13a is formed in this powder supply pipe 12. A cylinder side ventilating port 21a is formed on the upper face 17b of a cylinder 17. These respective ventilating ports 13a, 21a are communicated by an air hose 22. When the feeder box 11 advances, a piston 19 reduces the volume of a pressure action chamber 20, and the air in the pressure action chamber 20 is supplied into the feeder box 11. When the feeder box 11 retreats, the piston 19 increases the volume of the pressure action chamber 20, and the air in the feeder box 11 is supplied into the pressure action chamber 20. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a powder feeder device that fills a raw powder into a die cavity of a powder molding die device.

  The green compact molded by the powder molding die apparatus is formed on a die plate, and a die cavity is formed by a die hole forming the outer shape of the green compact and a lower punch forming the lower end surface. Is filled with raw material powder such as metal powder, and is pressed from above and below until reaching the target dimension by an upper punch and a lower punch that form the upper end surface. Generally, raw material powder filling is performed by a powder feeder including a feeder box that moves forward and backward on the die plate, a drive mechanism that moves the feeder box back and forth, a hopper provided at a high place, and a hose that connects the feeder box and the hopper. Done by the device. The raw material powder is loaded into a hopper provided at a high place, and dropped into a hose extending from the lower opening to the feeder box. Then, the raw material powder is transferred through the hose by automatic dropping and fed into the feeder box. When the feeder box supplied with the raw material powder is advanced by the drive mechanism and positioned on the die cavity, the raw material powder in the feeder box falls into the die cavity and the die cavity is filled with the raw material powder.

  At this time, the raw material powder falls by its own weight until it fills the die cavity from the hopper. That is, the lower raw material powder is pressed by the upper raw material powder and falls to the die cavity. Therefore, the pressing force of the upper raw material powder changes due to a change in the capacity of the raw material powder in the hopper or a change in the hopper. When the pressing force of the raw material powder changes in this way, there is a possibility that a problem that the amount of the raw material powder supplied to the feeder box varies. If the amount of the raw material powder supplied into the feeder box is different, the amount of the raw material powder filled in the die cavity will also be different. Will occur. As a method of solving this problem, there is a method of making the inside of the feeder box a negative pressure state by an intake device (see Patent Document 1). According to this method, since the raw material powder supplied from the hopper is sucked to the feeder box side by the suction device by using the intake device to bring the inside of the feeder box to a negative pressure state, the raw material powder is fed from the hopper to the feeder. Stable supply in the box.

   In addition, since air exists in the die cavity before the raw material powder is filled, the raw material powder and the air are exchanged when the raw material powder is filled. As a result, there arises a problem that the filling time of the raw material powder is lost, and the raw material powder is not uniformly filled in the die cavity. In order to solve such a problem, for example, there are methods described in Patent Document 2 and Patent Document 3. In the method of Patent Document 2, the inside of the die cavity is brought into a negative pressure state using a duct, and then the raw material powder is filled. Since the influence of air is suppressed in this method, the raw material powder is uniformly filled in the die cavity. In the method of Patent Document 3, air is supplied into the feeder box, and the raw material powder in the feeder box is naturally dropped while stirring the raw material powder to fill the die cavity with the raw material powder. According to this method, the filling time can be shortened, and the raw material powder can be stably filled in the die cavity.

Japanese Utility Model Publication No. 7-37496 JP-A-3-258498 Japanese Patent No. 2803645

  In the case of the above-mentioned patent document 2, a duct is pressed from above the die cavity simultaneously with the formation of the die cavity so that the inside of the die cavity is in a negative pressure state. For this reason, the suction operation | movement of the air in the die cavity by a duct is added to a general shaping | molding process. Moreover, since the feeder box of the said patent document 2 is provided with the duct ahead, the full length becomes long compared with the conventional feeder box. As a result, it takes time to fill the raw material powder as compared with a general powder feeder. The raw material powder may be composed of a plurality of powders such as iron and graphite. In this case, the raw material powder is mixed so that each powder is uniformly dispersed before molding. However, when such raw material powder is agitated and filled in the die cavity as in Patent Document 3, the powder having a low specific gravity is upward and the powder having a high specific gravity is biased downward in the die cavity. Is presumed to be filled. Moreover, in the method of each said patent document, various apparatuses, such as a duct and a suction device, are separately provided in the general powder feeder apparatus. For this reason, the structure is complicated compared with a general powder feeder apparatus.

  Therefore, the present invention provides a powder feeder device for filling a raw material powder in a die cavity so that the raw material powder can be stably filled into the die cavity, and the structure is simpler than that of a conventional device. An object is to provide an apparatus.

  The present invention is a feeder box provided to be movable back and forth along the upper surface of a die plate, a feeder box driving mechanism for moving the feeder box forward and backward, and connected to the feeder box via a powder feeding pipe and stored in a hopper. A powder feeder device comprising a flexible powder conduit for guiding powder into a feeder box and a cylinder device, and when the feeder box advances, the powder in the feeder box is dropped into a die cavity and supplied. The cylinder device includes a cylinder whose axial direction extends in the forward / backward direction of the feeder box, a piston rod that is hermetically inserted into one end of the cylinder, and one end fixed to the feeder box, and the other end of the piston rod It is fixed to the part and slidably fitted into the cylinder, and a pressure action chamber is formed in the cylinder. And a piston that reduces the volume of the pressure action chamber when the feeder box advances, and increases the volume of the pressure action chamber when the feeder box moves backward, and the cylinder communicates with the pressure action chamber and the outside. The cylinder side vent hole is provided, the feeder tube side vent hole is provided in the powder feed pipe, and the cylinder side vent hole and the feeder box side vent hole are communicated with each other by an air conduit.

  In the powder feeder of the present invention, when the feeder box advances, the air in the pressure acting chamber of the cylinder is compressed with the movement of the piston, and the compressed air is fed to the feeder box side through the cylinder side vent and the air conduit. Supplied from the mouth into the feeder box. When air is supplied into the feeder box during filling of the raw material powder, the raw material powder in the feeder box is always pushed at a constant pressure by the supplied air. As a result, the raw material powder is forcibly moved into the die cavity, and the raw material powder is stably filled into the die cavity. Next, when the feeder box retreats, air is sucked from the feeder box side vent and air is supplied from the cylinder side vent into the pressure working chamber of the cylinder via the air conduit. When air is sucked from the cylinder side vent when the feeder box is retracted, the raw material powder is sucked to the powder feed pipe side, and the fall of the raw material powder from the hopper is promoted. Thereby, the raw material powder dropped from the hopper smoothly moves into the feeder box, and the raw material powder is stably supplied into the feeder box.

  Further, in the cylinder device used in the feeder device of the present invention, air is supplied into the feeder box and air is sucked into the pressure acting chamber of the cylinder in conjunction with the advance / retreat operation of the feeder box. That is, the air supply operation and suction operation are controlled by the advance / retreat operation of the feeder box. For this reason, it is not necessary to separately provide a mechanism for controlling the air supply operation and the suction operation. Further, the cylinder device has a simple configuration as compared with a suction device or the like used in the prior art. As a result, in the powder feeder apparatus of the present invention, the air supply operation and the suction operation can be efficiently performed, and the cost can be reduced as compared with the conventional apparatus.

  Moreover, it is preferable that the cylinder of the cylinder apparatus of the powder feeder apparatus of the present invention is fixed on the die plate on the side of the backward direction of the feeder box or the feeder table flush with the die plate from the backward position where the feeder box stands by. By fixing the cylinder in this way, the cylinder device is disposed at a position where it does not interfere with the upper punch and the lower punch of the powder molding die device.

  According to the powder feeder device of the present invention, by providing the cylinder device, air is supplied into the feeder box from the cylinder side vent when the feeder box is advanced, and the supplied powder causes the raw material powder in the feeder box to be constant. Pressed with pressure. As a result, there is an effect that the raw material powder can be stably filled in the die cavity. Further, when the feeder box is retracted, the air is sucked from the cylinder side vents, thereby facilitating the dropping of the raw material powder from the hopper. As a result, there is an effect that the raw material powder can be stably supplied into the feeder box regardless of the remaining amount of the raw material powder in the hopper. In addition, since the cylinder device has a relatively simple configuration, the cost can be reduced as compared with the conventional device.

Hereinafter, the powder feeder of the present invention will be described with reference to the drawings.
[1] Powder Feeder Device FIG. 1 is a side view showing a die cavity of a powder mold device for forming a green compact, and a powder feeder device for filling raw material powder in the die cavity. The die cavity 1 filled with the raw material powder is formed by a die hole 3 formed in the die plate 2 that forms the outer shape of the green compact, and a lower punch (not shown) that forms the lower end surface of the green compact. The powder feeder apparatus 10 is formed in a substantially rectangular parallelepiped shape with the entire lower surface opened, and a feeder box 11 provided so as to be movable forward and backward along the upper surface 2a of the die plate 2 and a feeder box drive for moving the feeder box 11 back and forth. The mechanism 23, a funnel-shaped hopper 14 for storing the raw material powder therein, a flexible powder hose 15 for allowing the feeder box 11 and the hopper 14 to communicate with each other, and a rear side (right side in the figure) of the feeder box 11 A cylinder device 16 is provided, and a flexible air hose 22 that allows the inside of the feeder box 11 and the inside of the cylinder device 16 to communicate with each other. The hopper 14 is installed above the feeder box 11 in order to drop the raw material powder stored therein and supply it to the feeder box 11. The raw material powder is composed of a plurality of powders such as iron and copper. Such a raw material powder is mixed so that each powder may disperse | distribute uniformly before shaping | molding. The ingredients of the raw material powder are appropriately selected according to the specifications of the product.

  A rod 24 of a feeder box drive mechanism 23 is connected to the side surface 11 a of the feeder box 11. The feeder box drive mechanism 23 is configured to refill the feeder box 11 attached to the tip of the rod 24 by reciprocating the rod 24 in the horizontal direction, and to fill the raw material powder in the feeder box 11 into the die cavity 1 and the feeder. The box 11 is moved between the standby positions where the box 11 stands by. In the figure, the left direction is the forward direction of the feeder box 11, and the right direction is the backward direction of the feeder box 11.

  FIG. 2 is a partial cross-sectional view of the powder feeder apparatus 10 showing a state in which the raw material powder 4 is supplied into the die cavity 1. As shown in FIG. 2, a powder feed pipe 12 that extends obliquely rearward and communicates the inside of the feeder box 11 with the outside is integrally formed with the feeder box 11 at the upper rear end of the feeder box 11. One end of a powder hose 15 is connected to the powder supply pipe 12 as shown in FIG. The raw material powder stored in the hopper 14 falls from the lower port 14a of the hopper 14 into the feeder box 11 through the powder hose 15 and the powder feeding pipe 12 by its own weight. The powder hose 15 is made of, for example, rubber, and the length thereof is set to such an extent that the advance / retreat operation of the feeder box 11 is not hindered. Above the outer peripheral surface of the powder supply pipe 12, a feeder box side ventilation pipe 13 that communicates the inside and the outside of the powder supply pipe 12 is formed integrally with the powder supply pipe 12. An opening to the outside of the feeder box side ventilation pipe 13 is a feeder box side ventilation hole 13a.

  As shown in FIG. 2, the cylinder device 16 has an axial direction extending along the advancing / retreating direction of the feeder box 11, a cylindrical cylinder 17 having an open end, and an end portion of the cylinder 17 on the closed side. The piston rod 18 is hermetically inserted into 17 a and has one end fixed to the rear surface 11 b of the feeder box 11. The piston rod 18 is fixed to the other end of the piston rod 18 and is slidably fitted into the cylinder 17. And a piston 19. The cylinder 17 is installed on the upper surface 2a of the die plate 2 with the end 17a facing the forward direction of the feeder box 11 and the opening 17c facing the backward direction of the feeder box 11. In the cylinder device 16, an internal space formed by the cylinder 17, the piston 19, and the end portion 17 a is a pressure action chamber 20. A cylinder side vent pipe 21 is formed on the upper surface 17b of the cylinder 17 so as to extend upward and communicate the pressure acting chamber 20 with the outside. An opening to the outside of the cylinder side vent pipe 21 is a cylinder side vent 21a. Each end of the air hose 22 is connected to the cylinder side vent 21a and the feeder box side vent 13a. Thereby, the inside of the feeder box 11 and the inside of the cylinder 17 are communicated as described above. The air hose 22 is formed of rubber, for example, and the length thereof is set to such an extent that the forward / backward movement of the feeder box 11 is not hindered. The piston 19 is moved in the horizontal direction in the cylinder 17 as the feeder box 11 advances and retreats. The length of the cylinder 17 is such that when the feeder box 11 is positioned at the filling position, the piston 19 does not contact the end portion 17a, and when the feeder box 11 is positioned at the standby position, the piston 19 The length is set so as not to be detached from the opening 17c. The cylinder side vent pipe 21 is set so as to be closer to the forward direction of the feeder box 11 than the position of the piston 19 when the feeder box 11 is positioned at the filling position.

  When the feeder box 11 advances, the piston 19 also advances, and the volume of the pressure action chamber 20 decreases. As a result, the air in the pressure working chamber 20 is supplied from the feeder box side vent 13 a into the feeder box 11 via the cylinder side vent 21 a and the air hose 22. On the other hand, when the feeder box 11 is retracted, the piston 19 is also retracted, and the volume of the pressure acting chamber 20 is increased. Thereby, the air in the feeder box 11 is supplied to the pressure action chamber 20 from the cylinder side vent 21a via the feeder box side vent 13a and the air hose 22.

[2] Method of Filling Die Cavity with Raw Material Powder Next, a method of filling the raw material powder 4 into the die cavity 1 by the powder feeder 10 will be described with reference to FIGS.
First, the raw material powder 4 loaded in the hopper 14 falls from the lower opening 14a by its own weight as shown in FIG. 3, and is supplied into the feeder box 11 through the powder hose 15 and the powder feeding pipe 12. . When the raw material powder 4 is supplied into the feeder box 11, the feeder box drive mechanism 23 moves the feeder box 11 to the filling position as shown in FIG. At this time, in the cylinder device 16, the volume of the pressure acting chamber 20 is gradually reduced by the piston 19 as described above, and air is supplied into the feeder box 11. When air is supplied into the feeder box 11, the raw material powder 4 in the feeder box 11 is pushed downward by the supplied air. When the feeder box 11 is positioned at the filling position, the raw material powder 4 in the feeder box 11 falls by its own weight while being pushed downward. As a result, the raw powder 4 is filled in the die cavity 1. At this time, the raw material powder 4 is in a continuous state in the die cavity 1 and the feeder box 11.

  Next, the feeder box drive mechanism 23 moves the feeder box 11 backward as shown in FIG. When the feeder box 11 is retracted, the raw material powder 4 that is continuous in the die cavity 1 and the feeder box 11 is flush with the upper surface 2 a of the die plate 2 by the lower surface 11 c of the feeder box 11. Worn out. Further, since the raw material powder 4 is always falling from the hopper 14 by its own weight, when the raw material powder 4 is filled into the die cavity 1, the shortage falls from the hopper 14 into the feeder box 11. When the feeder box 11 is retracted, the piston 19 in the cylinder 17 is pushed in the retracting direction of the feeder box 11, thereby increasing the volume of the pressure acting chamber 20. At this time, the air in the feeder box 11 is supplied to the pressure action chamber 20 as described above. Then, the raw material powder 4 in the powder hose 15 is sucked toward the powder feeding tube 12 side, and the falling of the raw material powder 4 from the hopper 14 is promoted. When the feeder box 11 returns to the standby position, the filling of the raw material powder 4 into the die cavity 11 is completed.

  When the filling of the raw material powder 4 into the die cavity 1 is completed, the raw material powder 4 in the die cavity 1 is compressed from above and below by the upper punch and the lower punch as described above. Subsequently, the green compact is taken out from the die cavity 1 by raising the lower punch, and a green compact having a predetermined size is obtained.

  In the powder feeder apparatus 10 of this embodiment, when the feeder box 11 moves forward, the raw material powder 4 in the feeder box 11 is pressed downward by the air supplied from the pressure action chamber 20. In addition, the raw material powder 4 in the powder feeding tube 12 is pressed toward the feeder box 11 by the air supplied from the pressure action chamber 20. By the action of these air pressures, the raw material powder 4 in the feeder box 11 and the powder feed pipe 12 is promoted to fall into the die cavity 1, and when the feeder box 11 is positioned at the filling position, Is forcibly moved to. Next, when the feeder box 11 is retracted, air is sucked from the cylinder side vent 13a, and the raw material powder 4 in the powder hose 15 is sucked to the powder feed pipe 12 side. Thereby, the fall of the raw material powder 4 in the hopper 14 is promoted, and the raw material powder 4 dropped from the lower opening 14 a of the hopper 14 moves smoothly into the feeder box 11. As a result, in the powder feeder 10 of this embodiment, the raw material powder 4 is stably supplied from the hopper 14 into the feeder box 11, and the raw material powder 4 in the feeder box 11 is stabilized into the die cavity 1. Filled.

  Further, when the air in the feeder box 11 supplied with the raw material powder 4 is sucked, the raw material powder 4 in the feeder box 11 is sucked into the feeder box side vent 13a together with the air in the feeder box 11 and sucked. There is a possibility that a part of the raw material powder 4 moves into the pressure action chamber 20 through the hose. For this reason, in the powder feeder apparatus 10 of this embodiment, it is good to provide the filter which prevents the movement of the raw material powder 4 to the pressure action chamber 20 in the air hose 22 as needed.

  Further, the cylinder device 16 used in the powder feeder device 10 of the present embodiment supplies air into the feeder box 11 and sucks air into the pressure action chamber 20 of the cylinder 16 in conjunction with the advance / retreat operation of the feeder box 11. Is done. That is, the air supply operation and the suction operation are controlled by the advance / retreat operation of the feeder box 11. For this reason, it is not necessary to separately provide a mechanism for controlling the air supply operation and the suction operation. Further, the cylinder device 16 has a simple configuration as compared with a suction device or the like used in the prior art. As a result, in the powder feeder apparatus 10 of the present embodiment, the air supply operation and the suction operation can be efficiently performed, and the cost can be reduced as compared with the conventional apparatus.

  Further, the cylinder 17 of the cylinder device 16 of the powder feeder device 10 of the present embodiment is fixed to the upper surface 2a of the die plate 2 on the side of the feeder box 11 in the retracting direction from the standby position. By fixing the cylinder 17 in this way, the cylinder device 16 does not interfere with the upper punch and the lower punch of the powder molding die device, so that the safety of the device is ensured.

It is a side view which shows the die cavity of the powder metal mold apparatus which shape | molds a green compact, and the powder feeder apparatus with which raw material powder is filled in this die cavity. It is a fragmentary sectional view of the powder feeder apparatus which shows a mode that raw material powder is supplied in a die cavity. It is sectional drawing which shows the state in which the feeder box was waited in the standby position. It is sectional drawing which shows a mode that the raw material powder in a feeder box is filled into the die cavity. It is sectional drawing which shows a mode that a feeder box is retracted to a standby position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Die cavity 2 ... Die plate 2a ... Die plate upper surface 4 ... Raw material powder 10 ... Powder feeder apparatus 11 ... Feeder box 12 ... Powder feeding pipe 13a ... Feeder box side ventilation hole 14 ... Hopper 15 ... Powder hose 16 ... Cylinder apparatus 17 ... Cylinder 18 ... Piston rod 19 ... Piston 20 ... Pressure action chamber 21a ... Cylinder side vent 22 ... Air hose

Claims (2)

A feeder box provided to be movable back and forth along the upper surface of the die plate;
A feeder box drive mechanism for moving the feeder box forward and backward,
A flexible powder conduit connected to the feeder box via a powder feeding tube and guiding the powder stored in the hopper into the feeder box;
A cylinder device,
When the feeder box has advanced, a powder feeder apparatus that supplies powder by dropping the powder in the feeder box into a die cavity,
The cylinder device is
A cylinder whose axial direction extends in the forward and backward direction of the feeder box;
A piston rod that is airtightly inserted into one end of the cylinder and has one end fixed to the feeder box;
The piston rod is fixed to the other end of the piston rod and is slidably fitted into the cylinder.In the cylinder, a pressure action chamber is formed, and when the feeder box advances, the volume of the pressure action chamber is reduced. A piston that increases the volume of the pressure working chamber when the feeder box is retracted;
Further, the cylinder is provided with a cylinder side vent that communicates the pressure acting chamber and the outside.
The powder feeding pipe is provided with a feeder box side vent,
A powder feeder device in which the cylinder side vent hole and the feeder box side vent hole are communicated with each other by an air conduit.   The said cylinder of the said cylinder apparatus is fixed on the feeder table which is flush | planar with the die plate or die plate of the retraction direction side of a feeder box from the retreat position where the said feeder box waits. Powder feeder device.

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