JPS5929831Y2 - powder molding equipment - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a powder compacting device for compacting a green compact having at least an inclined upper surface to a uniform density.

Generally, as shown in Fig. 2a, as a device for forming powder using a metal mold, upper and lower punches 1 and 2 are used, a die 3 having a cavity is installed with its axis perpendicular, and the powder is formed in the cavity. Some machines supply powder and attach punches to a ram that moves up and down in the vertical direction, and use these to shape the powder into a green compact.

The molding apparatus shown in FIG. 2A is for molding a green compact 12 whose upper and lower surfaces are perpendicular to the axial direction as shown in FIG. 2A.

However, Fig. 1a. As shown in b, the green compact 4 whose upper surface is inclined and the green compact 5 whose upper and lower surfaces are inclined in the opposite direction are
It is impossible to mold with the molding device shown in the figure, and it is necessary to machine the product molded with this device afterwards.

Additionally, as shown in FIG. 3a, it is conceivable to use a molding device in which only the pressure surfaces 10a and 11a of the upper and lower punches 10 and 11 are inclined at an angle equal to the inclination angle of the powder compact. By molding, it is possible to obtain a powder compact 13 whose upper and lower surfaces are inclined as shown in FIG. 3, but this powder compact does not have a uniform density due to the difference in the compression ratio of the powder.

Furthermore, as shown in FIG. 4a, it is conceivable to use a molding device in which the upper surface 14a of the die 14 is also inclined at an angle equal to the inclination angle of the powder compact, and as shown in FIG. A tilted powder compact 15 can be obtained, and the powder compact 1 with
No. 5 is considered to have some success as it eliminates the difference in compression ratio and provides a uniform density, but there is a problem that the powder supplied to the cavity flows out to the outside due to the slope of the die upper surface 14a.

In addition, in FIG. 1, θ, θ1. θ2 is the inclination angle of the upper and lower surfaces of the compact, and in Figures 2 to 4, F, Fl, F
2. F' is the powder filling height, T, T1°T2. T' is the height of the powder compact, and θ is the inclination angle of the force surfaces of the upper and lower punches and the upper surface of the die.

This invention was made in view of the above-mentioned circumstances, and is a further improvement on the one shown in Figure 4a, in which the axial direction of the lower punch is inclined with respect to the vertical plane, and By making the top surface of the die with a sloped top surface horizontal or at an angle close to horizontal, it is possible to prevent the powder supplied to the cavity from flowing out, to ensure that the compression ratio is constant at each part, the density is accurately constant, and at least the top surface is An object of the present invention is to provide a powder compacting device capable of obtaining an inclined powder compact.

Hereinafter, an embodiment of this invention will be described in detail based on FIGS. 5 to 7.

Figures 5a and 5b show a compacted powder body 2 showing an embodiment of this invention.
0, which has a semicircular planar shape with only the top surface inclined by 1g.

In this way, when only the top surface of the compact is tilted, the top surface 21a of the die 21 is tilted with respect to the plane perpendicular to the axial direction at an inclination angle β calculated by the following formula, as shown in FIG. The upper surface 2 of the die 21 is tilted so that the compression ratio of the powder is constant.
1a is horizontal, and the axial direction of the upper punch 22 whose pressing surface 22a is inclined and the lower punch 23 whose pressing surface 23a is orthogonal to the axial direction is inclined in accordance with the axial direction of the die 21. be.

θ = Angle of inclination of the upper surface of the powder compact - Angle of inclination of the pressing surface of the upper punch T1 = Height of the powder compact MAX) T2 - Height of the powder compact MIN) ε = Compression ratio once F - Powder filling depth Incidentally, it is also possible to form a green compact with different inclination angles and directions of the upper and lower surfaces in the same manner as in the case of FIG. 6.

Note that FIG. 7 is a detailed view of FIG.

E, F, D are powder filling states, A, B, C, D are powder compaction states, Pl is upper punch, P2 is lower punch, T1 is height of powder compression in pigeon, Fl is powder filling at point A Height, T' is the height after powder compression at point G, which is a minute distance X' away from point A, F' is the powder filling height at point G, which is a minute distance X' away from point A, and θ is the end surface of the upper punch. β is the inclination angle with respect to the horizontal line of the top surface of the die, ε is the compression ratio ←tan→, and F is the filling depth necessary to compress the powder to a density of thickness Tf. be.

In Fig. 7, since the compression ratios in the axial direction at the input point and the G point must be equal, the following can be derived.

The following relational expression % formula %) Also, from the ■ formula, F, = εT2 From the ■ formula, εtanθ
"" tanβ ・・・・・・・・・・・・・・・
...■ Therefore, from the formula ■, any distance X from the direct entry
At points separated by , the formula ■ holds true.

Therefore, from Figure 5 becomes.

In other words, the above equation is set so that the extension line of the pressure surface of the upper punch at the pressure end point intersects at the point where the extension line of the upper surface of the die and the extension line of the upper surface of the lower punch intersect, and When the powder filled in the space formed by the lower punch is compressed by the upper punch to the pressure end point, a compacted powder body is formed uniformly and at an appropriate compression ratio ε.

Incidentally, regarding T and F in Figures 5 and 6 of the drawings, in Figure 7, the upper surface of the lower punch, the dimension A
When a button is pressed at an arbitrary point on surface D, the distance from that point to the top surface of the powder compact in the Y-axis direction is T, and similarly, the distance in terms of the top surface dimension of the die is F.

For example, in Figure 7, the T and F buttons pressed at point G
F=distance shown by G sweat T=distance shown by GI.

As detailed above, according to this invention, FIG.
It is possible to reliably mold a powder compact having at least an inclined upper surface to a uniform density, such as the powder compacts illustrated in FIGS. 2A and 2B and FIG. 5.

[Brief explanation of drawings]

Figures 1a and b are explanations showing different examples of green compacts having at least an inclined upper surface, Figures 2a and b, and Figure 3a.
Figures 4a and 4b are vertical cross-sectional views of the main parts showing the different powder compacting apparatuses that led to this invention, and longitudinal cross-sectional views of the compacts obtained with these apparatuses. Figures 5a and b are top and side views showing a powder compact according to an embodiment of this invention, Figure 6 is a longitudinal sectional view showing a powder compacting device of this invention, and Figure 7 is a detail view of Figure 6. It is a diagram. 4.5, 12, 13, 15... Green compact, 21.
...Die, 21a...Top surface of die, 22
, 23...Upper and lower punch, 22 as 23a
・・・・・・Pressure surface of punch.

Claims (1)

[Scope of utility model registration request] In a powder compacting apparatus for forming a green compact with at least an inclined upper surface, the axes of the upper and lower punches and the die are inclined with respect to the perpendicular line, the upper surface of the die is horizontal or at an angle close to horizontal, and the upper and lower punches are The pressing surface is inclined with respect to the axis, so that the extension line of the pressing surface of the upper punch at the end point of application intersects at the point where the extension line of the upper surface of the die and the extension line of the upper surface of the lower punch intersect. A powder molding apparatus characterized in that the powder filled in the space formed by the die and the lower punch is pressure-molded by the upper punch.