Powder forming apparatus

Abstract

To provide a powder molding device which can stabilize the supply of raw material powder by a feeder cup.SOLUTION: A powder supply device includes: a feeder cup 10 which supplies powder 30 to a filling part (recess 24) formed in a die 21; and a drive part which is connected to the feeder cup 10 and slides the feeder cup 10 onto the die 21. The feeder cup 10 includes: a powder storage part 21a which stores the powder 30 on the sliding surface side with the die 21 and releases the powder 30 to the filling part 24; and a through hole 11b which extends to the upper side of the die 21 and penetrates the powder storage part 21a and the outside and through which the powder 30 can pass therethrough.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a powder molding apparatus, and particularly to the structure of a feeder cup of a powder molding apparatus.

Background Art

[0002] In a powder molding apparatus, a feeder cup is used to supply raw material powder to a molding die (die). The feeder cup has a powder supply port for supplying raw material powder to the feeder cup, a powder storage portion for storing the raw material powder supplied from the powder supply port inside, and a powder input port for injecting the raw material powder stored in the powder storage portion into the die. Filling of the raw material powder into the die using the feeder cup is performed by moving the feeder cup onto the powder filling portion formed in the die. Specifically, along the upper part of the die, the feeder cup is advanced from a standby position toward the powder filling portion of the die, and then retreated from the advanced position back to the original standby position. The forward and backward movements of this feeder cup are performed such that the powder input port of the feeder cup passes over the powder filling portion formed in the die, and when the powder input port of the feeder cup passes over the powder filling portion of the die, the raw material powder falls from the powder input port of the feeder cup into the powder filling portion of the die, thereby filling the raw material powder into the die.

[0003] Patent Document 1 describes that an air discharge pipe that penetrates between the inside and the outside of the feeder cup is vertically installed on the upper lid of the feeder cup. By installing an air discharge pipe in the feeder cup, air between the feeder cup and the die can be released, and variation in the supply amount of the raw material powder filled in the filling portion formed in the die can be suppressed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] In the filling of the die's powder filling section with raw material powder, the forward and backward movement of the feeder cup is performed at high speed to achieve high production efficiency of molded products. Therefore, when the feeder cup transitions from its standby position to forward movement, from forward movement to stopping, from stopping to backward movement, and from backward movement to stopping, a rapid change in acceleration occurs in the raw material powder contained in the feeder cup's powder storage section, and a predetermined inertial force acts on the raw material powder. Due to this inertial force, the raw material powder in the powder storage section is pressed against the inner wall that constitutes the outer shape of the powder storage section; in other words, the raw material powder is compressed toward the inner wall of the powder storage section, and the raw material powder is gradually compacted. As a result, the sliding of the raw material powder is hindered, and problems arise such as instability in the amount of raw material powder falling into the die's powder filling section. Experiments by the inventors have shown that it is difficult to solve this problem simply by releasing the air between the feeder cup and the die.

[0006] The present invention aims to solve the above problems and provides a powder molding apparatus that can stabilize the supply of raw material powder by a feeder cup. [Means for solving the problem]

[0007] A powder supply device comprising a feeder cup for supplying powder to a filling section formed in a die, and a drive unit connected to the feeder cup for sliding the feeder cup on the die, wherein the feeder cup includes a powder storage section for storing the powder and releasing the powder to the filling section, and a through hole extending upward toward the die, through which the powder can pass between the powder storage section and the outside. The through-hole may be larger on the outside than on the outside of the powder storage section. Furthermore, the through hole may have a stepped portion in the middle. Furthermore, the outer shape of the stepped portion may be elongated, and the cross-section of the through-hole on the sliding surface side of the stepped portion may be circular. Furthermore, the feeder cup may also have a plurality of through holes, and the stepped portions of each of the plurality of through holes may be connected to form a recessed portion that extends from the surface of the feeder cup toward the stepped portion. Furthermore, the feeder cup may be equipped with a powder supply port for supplying the powder to the powder storage section, and the powder supply port and the through-hole may be positioned opposite each other in the sliding direction of the feeder cup. Furthermore, the powder storage section may have an inclined surface that slopes downward toward the lower surface as it moves from the powder supply port toward the through hole. [Effects of the Invention]

[0008] According to the powder molding apparatus of the present invention, it is possible to stabilize the supply of raw material powder by the feeder cup. [Brief explanation of the drawing]

[0009] [Figure 1] This is a side cross-sectional view of a powder molding apparatus according to one embodiment of the present invention. [Figure 2] This is a diagram illustrating in detail a feeder cup according to one embodiment of the present invention. [Modes for carrying out the invention]

[0010] The powder molding apparatus of the present invention will be described below with reference to drawings. In order to make the components easier to understand, the scale and number of components in the drawings may differ from the actual shapes and structures.

[0011] Figure 1 is a side cross-sectional view illustrating a powder molding apparatus according to one embodiment of the present invention. The powder molding apparatus 100 of this embodiment comprises a feeder cup 10, a die 21, an upper punch 22, and a lower punch 23. The feeder cup 10, die 21, upper punch 22, and lower punch 23 can be made of, for example, alloy tool steel SKD-11. The die 21 is provided with a through hole 21a, and the lower punch 23 is inserted from below the through hole 21a. A recess 24 is formed between the inner wall surface of the through hole 21a and the lower punch 23 inserted into the through hole 21a to accommodate the powder 30 that will be the raw material for the molded body. The upper punch 22 is also provided so as to be insertable into the through hole 21a of the die 21. With the powder 30 contained in the recess 24, the upper punch 22 is inserted from above the through hole 21a, and the powder 30 is compressed between the upper punch 22 and the lower punch 23 to produce the molded body.

[0012] A feeder cup 10 is placed on the die 21. The feeder cup 10 has a powder storage section 11a that stores powder 30 inside the feeder cup 10 and releases the powder 30 into the recess 24. The feeder cup 10 is also connected to a drive unit (not shown) and is slidably mounted along the surface of the die 21.

[0013] Figure 2 is a diagram illustrating in detail a feeder cup 10 according to one embodiment of the present invention, where (a) is a plan view and (b) is a cross-sectional view AA of (a). The feeder cup 10 of this embodiment consists of a base 11, a pipe mounting plate 12, and a powder supply pipe 13. The base 11 is a substantially rectangular parallelepiped member and is provided with a powder storage section 11a consisting of a through hole that passes from the upper surface to the lower surface of the base 11. The powder storage section 11a is a through hole with a rectangular cross-section inclined with respect to an axis perpendicular to the lower surface of the base 11 (the surface that is placed on the die 21), and when the base 11 is viewed from above rather than below, the positions of the opening of the powder storage section 11a on the upper surface of the base 11 and the opening of the powder storage section 11a on the lower surface do not overlap. This powder storage section 11a stores the powder 30 that will be used as the raw material for the molded body, and the opening of the powder supply section 11a on the lower surface of the base 11 functions as a powder inlet when the powder 30 is released from the feeder cup 10 into the recess 24.

[0014] Furthermore, the base 11 has a powder storage section 11a that extends upward (towards the top surface) of the base 11. The feeder cup 10 is provided with an extended through-hole 11b with a circular cross-section. The through-hole 11b extends from the powder storage section 11a near the opening of the powder storage section 11a on the lower surface of the base 11 and passes between the powder storage section 11a and the outside of the feeder cup 10. The diameter of the through-hole 11b is sufficiently large compared to the particle size of the powder 30 so that the powder 30 can pass through the through-hole 11b. In this embodiment, three through-holes 11b are provided in the base 11, and the diameter of each through-hole 11b is set to 3 mm, assuming the average particle size of the powder 30 is approximately 0.03 mm. It is preferable to set the diameter of the through-hole 11b to 50 to 150 times the particle size of the powder 30. This is because if the diameter of the through-hole 11b is too small, the powder 30 will not be able to enter smoothly, and if it is too large, the powder 30 will overflow to the outside of the feeder cup 10. The through-hole 11b may also be a tapered through-hole whose diameter increases from the powder storage section 11a upwards towards the base 11. In this case, the diameter of the opening communicating with the powder storage section 11a should be set to be sufficiently large relative to the particle size of the powder 30.

[0015] Furthermore, the base 11 of this embodiment is provided with a counterbore portion 11c on its upper surface. The counterbore portion 11c is a recess formed on the upper surface of the base 11, which is approximately elongated when viewed from above, and the upper opening of the through hole 11b is formed on the bottom surface of the counterbore portion 11c. In other words, the base 11 can also be said to be provided with a stepped portion (the bottom surface of the counterbore portion 11c) in the intermediate portion composed of the through hole 11b and the counterbore portion 11c. In this case, in this embodiment, each stepped portion formed in the intermediate portion of the multiple through holes 11b is connected to form a single counterbore portion 11c that is recessed into the stepped portion of the through hole 11b from the upper surface of the base 11.

[0016] A pipe mounting plate 12 is joined to the upper surface of the base 11. The pipe mounting plate 12 has a through hole 12a, which is inserted through the powder storage section 11a. More specifically, the through hole 12a is connected to and inserted through the opening of the powder storage section 11a on the upper surface of the base 11. The pipe mounting plate 12 is joined to the upper surface of the base 11 that does not overlap the counterbore section 11c of the base 11.

[0017] A cylindrical powder supply pipe 13 is attached to the through hole 12a of the pipe mounting plate 12 to supply powder 30 to the feeder cup 10. The powder supply pipe 13 is connected via a hose (not shown) to a hopper (not shown) where powder 30 is stored, and supplies the powder 30 supplied from the hopper to the powder storage section 11a.

[0018] Next, the manufacturing of a molded body using the powder molding apparatus 100 of this embodiment will be described. The manufacturing of the molded body can be carried out in the following steps. First, the feeder cup 10, in which powder 30 is stored in the powder supply unit 11a, is moved from a predetermined standby position toward the recess 24. Here, the direction of movement of the feeder cup 10 from the predetermined standby position toward the recess 24 is defined as the forward direction, and the direction opposite to the forward direction is defined as the backward direction, with the forward direction side of the feeder cup 10 being the front end side and the backward direction side being the rear end side. In the feeder cup 10 of this embodiment, the opening of the powder storage unit 11a on the lower surface of the base 11 is located toward the front end side of the feeder cup 10, and the opening of the powder storage unit 11a on the upper surface is located toward the rear end side.

[0019] The feeder cup 10 moves forward along the surface of the die 21 until the powder supply section 11a of the feeder cup 10 completely covers the top of the recess 24. Once the powder supply section 11a completely covers the recess 24, the feeder cup 10 is stopped for a certain period of time, and then the feeder cup 10 is moved backward to return the feeder cup 10 to its original standby position. During this forward, stop, and backward movement of the feeder cup 10, when the powder supply section 11a of the feeder cup 10 is positioned over the recess 24, powder 30 falls from the powder storage section 11a of the feeder cup 10 into the recess 24, filling the recess 24 with powder 30.

[0020] When the recess 24 is filled with the powder 30, the upper punch 22 is inserted from above the through hole 21a, and the powder 30 is compressed between the upper punch 22 and the lower punch 23 to produce a molded body. Then, the upper punch 22 and the lower punch 23 are moved upward with respect to the die 21, and the molded body is discharged from the die 21. By repeating the above operations, a plurality of molded bodies can be produced.

[0021] Here, when the feeder cup 10 moves in the forward and backward directions, a predetermined inertial force acts on the powder 30 when the traveling direction of the feeder cup 10 is switched. Particularly, when switching from forward to stop, since the powder storage portion 11a may be inclined toward the tip side, due to the self-weight of the powder 30 supplied to the feeder cup 10 and the inertial force acting on the powder 30, the powder 30 tends to aggregate (be compressed) on the tip side of the powder storage portion 11a. However, the feeder cup 10 of the present embodiment is provided with a through hole 11b that penetrates between the powder storage portion 11a and the outside of the feeder cup 10 near the opening of the powder storage portion 11a on the lower surface of the pedestal 11, that is, on the tip side of the feeder cup 10. Since the through hole 11b is configured to have a size that allows the powder 30 to pass through sufficiently, when the powder 30 receives the self-weight and the inertial force, the through hole 11b serves as a escape path for the powder 30, and it is possible to suppress the excessive pressure from acting on the powder 30. Therefore, the phenomenon that the powder 30 aggregates is suppressed, and it becomes possible to stably supply the powder 30 to the recess 24.

[0022] Furthermore, the through-hole 11b extends upward toward the feeder cup 10. Therefore, powder 30 that enters the through-hole 11b from the powder storage section 11a will return to the powder storage section 11a due to the negative pressure created by the pressure drop in the powder storage section 11a and the weight of the powder 30 itself. Thus, leakage of powder 30 to the outside of the feeder cup 10 can be suppressed. In addition, the feeder cup 10 of this embodiment is provided with a counterbore section 11c at the upper opening of the through-hole 11b, which has an opening larger than the upper opening of the through-hole 11b. This counterbore section 11c functions as a retainer for powder 30 that passes through the through-hole 11b and scatters out from the through-hole 11b, making it possible to more reliably suppress leakage of powder 30 to the outside of the feeder cup 10. Furthermore, depending on the size of the opening in the recessed portion 11c, almost all of the powder 30 held in the recessed portion 11c can be returned to the powder storage portion 11a by the movement of the feeder cup 10 and the negative pressure generated in the powder storage portion 11a by that movement.

[0023] The powder supply device of the present invention has been described above based on embodiments, but the scope of the present invention is not limited to the embodiments described above and can be arbitrarily modified within the scope of the technical concept of the present invention. For example, the powder storage portion 11a of the feeder cup 10 in this embodiment was described as a through hole with a square cross-section, but it may have a circular cross-section or other shapes. Also, although the configuration was made with three through holes 11b, the number of through holes 11b is not limited to three, and one or more is sufficient. Also, although the through holes 11b were made with a circular cross-section, they may have a rectangular cross-section, for example. Also, although the counterbore portion 11c was made with a roughly elongated hole shape when viewed from above, it may have a circular, elliptical, or rectangular shape, for example. Also, although the material of the die 21, feeder cup 10, upper punch 22, and lower punch 23 was made of alloy tool steel SKD-11, it is not limited to alloy tool steel SKD-11, and cemented carbide may be used. [Explanation of Symbols]

[0024] 10 Feeder Cups 11 Pedestal 11a Powder storage section 11b Through hole 11c Counterbore section 12 Pipe mounting plate 12a Through hole 13 Powder supply pipe 21 Dies 21a Through hole 22 Upper punch 23. Lower punch 24 recesses 30 powder 100 powder feeding equipment

Claims

1. A powder supply device comprising a feeder cup for supplying powder to a filling section formed in a die, and a drive unit connected to the feeder cup for sliding the feeder cup on the die, The feeder cup comprises a powder storage section for storing the powder and releasing the powder to the filling section, and a through hole extending upward toward the die, through which the powder can pass between the powder storage section and the outside. The powder supply device is characterized in that the through-hole has a larger opening exposed to the outside than the opening exposed to the powder storage section, and has a powder holding section that holds the powder that passes through the through-hole and scatters to the outside.

2. The powder supply device according to claim 1, characterized in that the through hole has a stepped portion in the middle, the powder holding portion has the stepped portion as its bottom surface and is a recess that communicates with the external opening of the through hole.

3. The powder apparatus according to claim 2, characterized in that the outer shape of the stepped portion is elongated, and the cross-section of the through hole on the sliding surface side of the stepped portion is circular.

4. The powder apparatus according to claim 2, characterized in that it has a plurality of through holes, and the stepped portions of each of the plurality of through holes are connected to form a recessed portion that extends from the surface of the feeder cup toward the stepped portion.

5. The feeder cup is equipped with a powder supply port for supplying the powder to the powder storage section. The powder supply device according to claim 1, characterized in that the powder supply port and the through hole are arranged opposite each other in the sliding direction of the feeder cup.

6. A powder supply device comprising a feeder cup for supplying powder to a filling section formed in a die, and a drive unit connected to the feeder cup for sliding the feeder cup on the die, The feeder cup comprises a powder storage section for storing the powder and discharging the powder to the filling section, a through hole extending upward toward the die and through which the powder can pass between the powder storage section and the outside, and a powder supply port for supplying the powder to the powder storage section. The powder supply port and the through hole are arranged opposite each other in the sliding direction of the feeder cup. The powder supply device is characterized in that the powder storage section has an inclined surface that slopes downward from the powder supply port toward the through hole.

Images