JPS6140737Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a helical gear forming device.

Conventionally, it has not been possible to accurately manufacture products with complex shapes by compressing metal powder in a closed space formed by a die and upper and lower punches using powder metallurgy, or by recompressing a sintered body. It is publicly known.

However, when forming a helical gear using the above method, the tooth profile fitting part between the inner circumference of the die and the outer circumference of the upper and lower punches has a helical helix angle. In addition, it is necessary to synchronize the phase between the outer circumference of the upper punch that protrudes and retracts from the die and the helical groove on the inner circumference of the die. For example, as one of the inventions, the inventor of the present invention also published Utility Model Registration Application No. 27354 in 1981, ``Helical gear forming device'' (Jikkosho).
No. 59-32571) (hereinafter referred to as the earlier application's invention).

That is, as shown in FIG. 1, the prior application has a die 2 which has a helical groove on the inner periphery and is fixed to the center of the die plate 1, and a die 2 which has a helical groove on the outer periphery. A lower punch 3 and an upper punch 4 are fitted to move in the axial direction (vertical direction) and are rotatable by thrust bearings 9, 10, etc., and a helical groove is provided on the inner periphery of the upper punch 4. Tuning ring 5 that fits externally
, the well-known radially expandable Shupan ring 7
The upper punch mounting base 8 is lowered from the press top dead center state shown in FIG. 1 and adjusted as shown in FIG. 2. With the lower end surface of the screw 11 in contact with the upper surface of the die plate 1 and a predetermined space being secured between the upper surface of the die 2 and the lower surface of the tuning ring 5, the outer periphery of the upper punch 4 and the inner periphery of the die 2 are The upper punch mounting base 8 is further lowered and the third groove is fitted.
When the press reaches the bottom dead center state shown in the figure, the material W in the die 2 is compressed between the upper and lower punches 4 and 3 to form a helical gear with a predetermined width.

However, since the tuning ring 5 for tuning and guiding the upper punch 4 with respect to the die 2 is integral, there may be problems in assembly due to machining errors at the tooth-shaped fitting portion between the upper punch 4 and the tuning ring 5 during manufacturing. Evenly, due to an increase in tackiness due to wear that occurs during use and a change in tackiness due to temperature differences, the outer periphery of the upper punch 4 will be slightly different from the die in the predetermined relationship between the die 2 and the tuning ring 5 shown in FIG. 2. The inner circumference of 2 does not fit with the helical groove,
As the upper punch 4 descends, the upper punch 4 collides with the upper punch 4, which often causes flaws or damage to the die, punch, etc.

In order to eliminate the drawbacks of the tuning ring, the present invention eliminates the integrated tuning ring and uses an upper and lower adjustment ring that is divided into upper and lower parts, and adjusts the axial spacing between them. The present invention provides a helical gear forming apparatus characterized in that the helical gear forming apparatus is provided so as to maintain the tightness of the upper punch at an optimum value by utilizing the helix angle, and will be described below with reference to the drawings.

4 and 5 are enlarged views of the main parts of an embodiment of the present invention, that is, the part corresponding to the section A in FIG. 1, and FIG. The figure is a view taken in the direction of the V arrow in FIG. 4. For example, in the conventional helical gear forming apparatus shown in FIG. Then, either one of the upper adjustment ring 12 and the lower adjustment ring 13 (the lower adjustment ring in the illustrated example), which are provided so as to fit on the upper punch 4, is attached to the center of the guide plate 6 via the punch ring 7. The upper adjustment ring 12 and the lower adjustment ring 13 are fixed, and the upper adjustment ring 12 and the lower adjustment ring 13 are made relatively movable in the vertical axial direction, and are placed at symmetrical positions at their circumferential boundaries, for example, so that they do not rotate relative to each other in the rotational direction. Rotation locking part 1 with a parallel pin installed in the axial direction
4, and by interposing a distance adjusting device 15 such as a spacer or shim on the mating surfaces of both in the axial direction to allow relative movement in the axial direction, In addition, the gap formed by the upper adjustment ring 12 and the lower adjustment ring 13 can be set to a small value with respect to the helix of the upper punch 4 to an optimum value of, for example, about 0.01 mm within a range that does not interfere with sliding.

In other words, the twist angle of the helix is β, and the interval adjuster 1
If the axial adjustment allowance according to 5 is △t, the amount of change in backlash in the direction perpendicular to the axis is δ=tanβ・t△ (1), and by reducing the backlash that increases due to wear etc. Fluctuations (backlash) in the rotational direction of the upper punch 4 can be eliminated, and the phase of the helical can be accurately matched with the helical groove of the die 2. After the interval is adjusted, the upper adjustment ring 12 and the lower adjustment ring 13 are tightened and integrated with a fixing member 16 such as a tightening bolt.

Note that the rotation locking portion 14 provided between the upper adjustment ring 12 and the lower adjustment ring 13 is not limited to a parallel pin, but may be a key, a spline, a serration, a square fitting, etc., and the interval adjustment tool 15 may be a spacer. In addition to shims, the spacing can be adjusted by using the repulsive force of an elastic body such as rubber, or by screwing a push bolt into one adjustment ring and pressing the other adjustment ring with the tip. It can also be provided as follows.

Furthermore, the adjustment rings are equipped with grease nipples and oil guide holes (not shown) so as to lubricate the sliding surface with the upper punch 4 by utilizing the gap between the mating surfaces in the helical grooves on the inner circumferences of the upper and lower adjustment rings 12 and 13. A groove or the like may be provided to supply lubricating oil.

Alternatively, it is possible to adjust the backlash by relatively rotating the upper and lower adjustment rings 12 and 13, but since the structure becomes complicated, the axial adjustment according to the present invention is preferable.

Since the present invention is constructed as described above, it is possible to easily adjust the backlash between the upper punch and the adjustment ring to the optimum value using a simple mechanism, and therefore to accurately match the tooth profile fitting portion between the upper punch and the die. damage to the mold etc. can be prevented.

[Brief explanation of drawings]

Figures 1 to 3 show an example of a conventional helical gear forming device. Figure 1 is a rotating sectional view taken at different positions on the left and right in the top dead center state of the press, and Figure 2 is a vertical cross-sectional view of the top of the die and the upper punch. FIG. 3 is a partially rotated sectional view in a state where the lower surface coincides with the press bottom dead center, FIGS. 4 to 6 show main parts in an embodiment of the present invention, and FIG. Figure 5-
A cross-sectional view along the line, FIG. 5 is a view taken in the direction of the V arrow in FIG. 4,
FIG. 6 is a partial exploded vertical cross-sectional view of the fitting tooth portion shown in FIG. 4 on the pitch circle. 1... Die plate, 2... Die, 3... Lower punch, 4... Upper punch, 5... Tuning ring, 6...
...Guide plate, 7...Shuppan ring, 8...
...Upper punch mounting base, 9,10...Thrust bearing,
11...adjustment screw, 12...upper adjustment ring, 1
3...Lower adjustment ring, 14...Rotation locking part, 1
5... Spacing adjustment tool, 16... Fixing tool, W... Material, β... Helix angle, Δt... Axial adjustment allowance, δ... Amount of change in deflection in the direction perpendicular to the axis, a
+b...Breakness in the direction perpendicular to the axis.

Claims (1)

[Scope of utility model registration request] A die 2 has a helical groove on its inner periphery and is fixed to the center of the die plate 1, and a die 2 has a helical groove on its outer periphery and can be fitted into the die 2 to move in the axial direction and rotate. A lower punch 3 and an upper punch 4 provided in the
A tuning ring 5 having a helical groove on the inner periphery and fitting onto the upper punch 4 is provided with a guide plate 6 fixed to the center and movable up and down, so that the material inside the die 2 can be moved up and down. In an apparatus for forming a helical gear by compressing between punches 4 and 3, the tuning ring 5 is divided into an upper and lower axial direction to form an upper adjustment ring 12 and a lower adjustment ring 13, and the upper and lower adjustment rings 1
A helical gear forming device characterized in that a rotation locking part 14, an axial interval adjustment tool 15, and a fixture 16 are provided between 2 and 13.