JPH069797U - Powder molding equipment - Google Patents

Abstract

(57) [Summary] [Purpose] Powder compaction is performed without sliding on the inner wall surface of the die. [Structure] The material powder B is put into a die 20 provided on the fixed base 10, and is pressed in the direction of arrow A by an upper punch 30 to be compression-molded. The molding part 21 of the die 20 is formed in accordance with the desired shape of the molded product. The cylindrical portion 22 of the die 20 communicates with the molding portion 21 and is formed such that the inner diameter thereof is slightly smaller than the dimension W of the molding portion 21 in the direction perpendicular to the arrow A direction. The upper punch 30 has a cylindrical portion 22.
The material powder B, which is slidably fitted in the container, is compressed with a predetermined pressure.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a powder molding device for compression-molding powder such as glass, ceramics, and metal powder into a desired shape.

[0002]

[Prior art]

 As a conventional powder molding device, there is a device including a die 50 having a cylindrical portion 51 and upper and lower punches 60 and 61 as shown in FIG. The upper punch 60 is slidably fitted into the cylindrical portion 51 of the die 50 from above and is driven up and down by a hydraulic or pneumatic cylinder (not shown). The lower punch 61 is fitted into the cylindrical portion 51 from below. In such an apparatus, the material powder B is put into the die 50, and the upper punch 60 is slid in the cylindrical portion 51 in the direction of arrow A. As a result, the material powder B is compressed between the material powder B and the lower punch 61 and formed into a cylindrical shape.

[0003]

[Problems to be solved by the device]

 In the conventional powder molding apparatus described above, when the material powder B put into the cylindrical portion 51 of the die 50 is pressed by the upper punch 60 in the direction of arrow A, the material powder B causes friction with the inner wall surface of the cylindrical portion 51. Since the material is compressed while receiving it, especially when the material powder B is a fine powder with a particle size of 5 μm or less, a fault (partial crack) C as shown in FIG. However, there is a problem of causing cracks and the like. Further, even if the surface of the die 50 and the upper and lower punches 60, 61 are subjected to heat treatment (quenching) or the like, they are abraded over time and become rough, which may cause mold release defects. There is a problem that arises.

Further, when the shape of the desired molded product is not cylindrical, it is necessary to form the cylindrical portion 51 of the die 50 and the upper and lower punches 60, 61 for each desired shape of the molded product. There is a problem that the cost is not only high, but also high. That is, when the material powder B is formed into, for example, a polygonal shape, it is necessary to form the cylindrical portion 51 of the die 50 and the upper and lower punches 60 and 61 into a polygonal shape and fit them with a clearance of several μm. For this reason, processing of the cylindrical portion 51 of the die 50 and the upper and lower punches 60, 61 requires extremely high accuracy, which requires a lot of time and labor and causes a problem of cost increase.

Further, after compression molding, the molded product can only be taken out by sliding it inside the cylindrical portion 51 of the die 50. Therefore, even if the inner wall surface of the cylindrical portion 51 is mirror-finished, There is a problem that numerous scratches D as shown in FIG.

According to the present invention, the powder can be compression-molded without sliding on the inner wall surface of the molding part of the die, which can surely prevent a fault from occurring in the molded product. Moreover, it is an object of the present invention to provide a powder molding apparatus that can easily obtain molded products of various shapes simply by changing the shape of the molding portion.

[0007]

[Means for Solving the Problems]

 A powder molding apparatus according to the present invention comprises a die having a molding portion formed in accordance with a shape for molding powder and a cylindrical portion communicating with the molding portion, and a die slidably inserted into the cylindrical portion to form a powder. A punch for compressing the body from the cylindrical portion to the molding portion side is provided, and the inner diameter of the cylindrical portion is formed to be smaller than the widthwise dimension of the molding portion. It is characterized by being compressed and formed by the pressure of the punch transmitted through the powder in the cylindrical portion.

[0008]

【Example】

 The present invention will be described below with reference to illustrated embodiments. 1 and 2 are sectional views showing a powder molding apparatus according to a first embodiment of the present invention. In these figures, the material powder B is thrown into the die 20 provided on the fixed base 10 and is pressed in the direction of arrow A by the upper punch 30 to be compression-molded.

The die 20 is provided with a molding portion 21 and a cylindrical portion 22 penetrating in the vertical direction. The molding part 21 is formed according to the desired shape of the molded product. The inner wall surface of the molding portion 21 is formed to be inclined at a predetermined angle θ (FIG. 1) so as to gradually spread in the direction of arrow A. The cylindrical portion 22 communicates with the forming portion 21 so that the inner diameter is smaller than the dimension W of the forming portion 21 in the direction perpendicular to the arrow A direction (hereinafter, referred to as the width direction dimension W) (FIG. 1). It is formed. The upper punch 30 is slidably fitted in the cylindrical portion 22 so as to be slidable in the upper and lower directions, and compresses the introduced material powder B. When the material powder B is compressed by the upper punch 30, the die 20 is prevented from expanding in the width direction by the tightening ring 23 engaged with the outer surface. The fastening ring 23 has a lower end portion screwed into the upper end portion of the fixing base 10.

The upper punch 30 is formed into a cylindrical shape having a diameter that is smaller than the widthwise dimension W of the forming portion 21 by about 2 to 5 mm, and is slidably fitted into the cylindrical portion 22 of the die 20. The upper punch 30 is driven up and down by a hydraulic or pneumatic cylinder or the like (not shown) to compress the material powder B at a predetermined pressure.

On the inner wall surface of the molding portion 21 of the die 20, the inner wall surface of the cylindrical portion 22, and the outer surface of the upper punch 30, a ternary element made of Ni-B-W, Ni-Co-W, and Ni-Co-B is formed. Alloy or quaternary alloy consisting of Ni-Co-Cr-Si, Ni-Co-Cr-B, Ni-Cr-B-Si is plated or spray-coated to a thickness of about 0.2 mm. A layer P is formed.

The operation of this embodiment will be described. The material powder B is put into the molding part 21 and the cylindrical part 22 of the die 20, and the upper punch 30 is lowered while sliding inside the cylindrical part 22. As a result, the material powder B in the cylindrical portion 22 is pressurized at a predetermined pressure in the direction of arrow A and is flowed in the radial direction from the center of the molding portion 21. Then, it is compression molded into the shape of the molding portion 21. At this time, since the inner diameter of the cylindrical portion 22 is smaller than the widthwise dimension W of the forming portion 21, the material powder B in the vicinity of the inner wall surface of the forming portion 21 is formed only by pressure transmission, and the inner wall surface of the forming portion 21 There is no friction between them.

After the pressurization is completed, the tightening ring 23 is loosened, the die 20 is removed from the fixed base 10, and the molded product is released from the mold. This mold release can be performed extremely easily by inclining the inner wall surface of the molding portion 21 so as to gradually spread in the direction of arrow A, and it is possible to reliably prevent scratches and the like from entering the outer surface of the molded product.

By the way, the inner wall surface of the molding portion 21 of the die 20 does not cause wear because it does not cause friction with the material powder B, but the surface of the inner surface of the molding portion 21 does not wear due to pressure. Need to increase hardness. The surface hardness of the inner wall surface of the cylindrical portion 22 of the die 20 and the outer surface of the upper punch 30 must also be increased in order to prevent abrasion due to sliding of the upper punch 30.

Conventionally, as a method for increasing the surface hardness, there is a method by heat treatment (quenching / tempering), but in such a method, the limit is to increase the hardness to 60 (HRC). For this reason, in the conventional powder molding apparatus, the inner wall surface of the die becomes rough due to the abrasion of the material powder B, and the mold release defect of the molded product occurs. Moreover, when the surface hardness is increased, the tensile strength of the material is extremely lowered, so that the wall thickness of the material has to be increased, and there is a problem that the weight increase and the size increase of the molded product cannot be avoided.

The inventor of the present invention paid attention to the property that the tensile strength of the material is improved when the heat treatment hardness is up to about 45 to 50 (HRC). Then, the heat treatment hardness of the inner wall surface of the molding portion 21 of the die 20, the inner wall surface of the cylindrical portion 22 and the outer surface of the upper punch 30 is suppressed to about 45 (HRC), and the above-mentioned coating layer P is formed on those surfaces. It was As a result, the surface hardness of the inner wall surface of the molding portion 21 of the die 20, the inner wall surface of the cylindrical portion 22 and the outer surface of the upper punch 30 can be increased to 65 (HRC) or more while improving the tensile strength. . Therefore, it is possible to reliably prevent the material powder B from being intruded into the inner wall surface of the molding portion 21 of the die 20 and the abrasion of the inner wall surface of the cylindrical portion 22 of the die 20 and the outer surface of the upper punch 30.

As described above, according to the first embodiment, since the diameter of the upper punch 30 is smaller than the widthwise dimension W of the forming portion 21, the material powder B is applied between the material powder B and the inner wall surface of the forming portion 21. It does not cause friction and is compression molded by pressure transmission alone. As a result, even a fine powder having a particle size of 5 μm or less can be formed into a desired shape without causing a fault (partial crack). Further, abrasion of the inner wall surface of the molding portion 21 is also prevented.

When the shape of the molded product is changed, only the shape of the molding portion 21 of the die 20 needs to be changed, and it is necessary to change the shapes of the cylindrical portion of the die and the punch as in the conventional device. Absent. In particular, since the upper punch 30 can be used in various shapes of molded products while maintaining the cylindrical shape, it is easy to process and the compatibility of the apparatus is improved.

Further, since the inner wall surface of the molding portion 21 is inclined so as to gradually spread along the direction of arrow A, the molded product can be easily released from the mold after compression molding, and the outer surface of the molded product is rubbed. It is possible to prevent scratches and the like from entering. Furthermore, if the inner wall surface of the molded portion 21 is mirror-finished, the outer surface of the molded product can be easily mirror-finished.

FIG. 3 is a sectional view showing a powder molding apparatus according to a second embodiment of the present invention. In this figure, the die 40 is divided into two parts, a core member 42 having a molding portion 41 and a fitting member 44 having a cylindrical portion 43. The fitting member 44 is positioned on the core member 42 by fitting a plurality of guide pins 45 protruding on the lower surface in the circumferential direction into a guide groove 46 formed on the upper surface of the core member 42. . The shaped portion 41 of the core member 42 is formed in a hexagonal column shape.

The operation of this embodiment will be described with reference to FIG. The material powder B is thrown into the molding portion 41 of the core member 42 and the cylindrical portion 43 of the fitting member 44, and the upper punch 30 is lowered while sliding inside the cylindrical portion 43. As a result, the material powder B in the cylindrical portion 43 is pressed in the direction of arrow A (FIG. 4A) and radially flows from the center of the hexagonal columnar shaped portion 41 in the direction of arrow E (FIG. 4). (B)). Then, it is compression molded into a hexagonal column (FIG. 4 (c)).

As described above, according to the second embodiment, since the die 40 is divided into the core member 42 and the fitting member 44, the shape of the molding portion 41 can be easily processed into a more free shape. Therefore, it is possible to easily cope with more shapes of molded products. Further, the material powder B in the cylindrical portion 43 is made to flow in the radial direction (direction of arrow E) from the center of the molding portion 41 by pressurization and is molded into a hexagonal column, so a molded product having a fine and complicated shape other than the hexagonal column is formed. Even if it is, it can be molded without causing cracks or cracks.

FIG. 5 is a diagram showing a compression molding process of the powder molding apparatus according to the third embodiment of the present invention. The structure of this powder molding apparatus is the same as that of the powder molding apparatus of the second embodiment shown in FIG. 3 except that the molding portion 41 of the core member 42 is formed in the shape of a gear.

The operation of this embodiment will be described. The material powder B is thrown into the molding portion 41 of the core member 42 and the cylindrical portion 43 of the fitting member 44, and the upper punch 30 is lowered while sliding inside the cylindrical portion 43. As a result, the material powder B in the cylindrical portion 43 is pressed in the direction of arrow A (FIG. 5 (a)), and radially flows from the center of the gear-shaped forming portion 41 in the direction of arrow E (FIG. 5). (B)). Then, it is compression molded into a gear shape (Fig. 5 (c)).

[0025]

[Effect of device]

 As described above, according to the present invention, the powder can be compression-molded without sliding on the inner wall surface of the molding portion of the die, thereby reliably preventing a fault or the like from occurring in the molded product. Moreover, it is possible to easily obtain molded products of various shapes simply by changing the shape of the molded portion.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state before pressurizing material powder of a powder molding apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state after the material powder of the powder molding apparatus of FIG. 1 is pressed.

FIG. 3 is a cross-sectional view showing a state after the material powder is pressurized in the powder molding apparatus according to the second embodiment of the present invention.

FIG. 4 is a perspective view showing the concept of a powder compression molding process by the powder molding apparatus of FIG.

5 is a perspective view showing the concept of a powder compression molding process by the powder molding apparatus of FIG. 3. FIG.

FIG. 6 is a cross-sectional view showing a state after pressurizing material powder of a conventional powder molding apparatus.

7 is a perspective view showing a molded product compression-molded by the powder molding apparatus of FIG.

[Explanation of symbols]

 20 die 21 forming part 22 cylindrical part 30 punch B material powder (powder) W width direction dimension of forming part P coating layer

Claims (4)

[Scope of utility model registration request] 1. A die having a molding portion formed in accordance with a shape for molding powder and a cylindrical portion communicating with the molding portion; A compacting punch is provided on the molding portion side, and the inner diameter of the cylindrical portion is formed to be smaller than the width-direction dimension of the molding portion. A powder molding apparatus, which is compression-molded by the pressure of a punch transmitted through a body. 2. The powder molding apparatus according to claim 1, wherein the inner wall surface of the molding portion of the die is formed so as to be inclined so as to gradually spread in the compression direction of the powder by the punch. . 3. Ni-B-W and Ni-C are formed on the inner wall surface of the molding portion of the die, the inner wall surface of the cylindrical portion and the outer surface of the punch.
ternary alloy consisting of o-W and Ni-Co-B, or Ni
-Co-Cr-Si, Ni-Co-Cr-B, Ni-C
2. One of r-B-Si quaternary alloys is plated or spray coated.
Alternatively, the powder molding apparatus described in 2. 4. The powder according to claim 1, wherein the die comprises a core member having a molding portion and a fitting member fitted to the core member and having a cylindrical portion. Body shaping equipment.