JPH07178498A - Manufacture of helical planetary gear and die to be used for its manufacture - Google Patents

Abstract

PURPOSE:To manufacture a helical planetary gear by the cold forging with a simple means in an easy and rapid manner at a low cost. CONSTITUTION:The diameter of a cylindrical gear stock 2 is D2 which is approximately equal to the diameter of the pitch circle of a helical planetary gear to be manufactured, and the gear stock 2 is engaged from an inlet with a die 3 where the recessed bar 7 to form the gear teeth and the projecting bar 8 to form the space are formed helical with the pitch circle of the diameter D3 which is approximately equal to the diameter of the pitch circle of the gear and pressed with a punch 4 and press-fitted into the die 3. The helical tooth 5 and the helical space 6 corresponding to the recessed bar 7 and the projecting bar 8 are plastically formed while the gear stock is rotated along the helical recessed bar 7 and the helical projecting bar 8 in the die 3, and then, a plastically formed product 10 is pushed outside the die 3 through the following gear stock 2 to manufacture the helical planetary gear.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a helical planetary gear of a planetary gear type transmission for an automobile, and a mold used for manufacturing the helical planetary gear.

[0002]

2. Description of the Related Art Regarding the manufacturing of gears, some have been proposed in the past, but most of the ones currently realized are manufactured by cutting a material with a hobbing machine or other gear cutting machine. One is to manufacture a gear by plastically working a material. The present invention is a method and apparatus for manufacturing the helical planetary gear by the latter, that is, plastic working.

As a means for producing a gear-like material by plastically working a material, for example, there is one described in Japanese Patent Laid-Open No. 4-228220. This is not a helical gear,
The present invention relates to the manufacture of helical parts such as rotors used in screw pumps, but it is similar to the present invention in that it has helical teeth and groove, and its manufacturing method is as follows. .

That is, a blank (material) is loaded in the die hole of a die in which a helical die hole for the purpose of manufacture and a lead is formed on the inner peripheral surface, and a helical similar to the above-mentioned helical unevenness and having a reduced diameter. By pressing the blank into the gap between the helical punch and the die while rotating it relative to the die, the blank is pushed into the gap between the helical punch and the helical die hole to form a hollow body having a plurality of helical grooves on the outer circumference. .

[0005]

However, in the above-mentioned means for manufacturing a helical part, it is necessary to use a punch, which is an upper die, which is formed in a helical shape on the outer circumference like the inner circumference of the die. It is necessary to push the punch while rotating it against the die. Therefore, the shape of the punch is complicated and the die cost becomes high, and it is necessary for the press machine to have a mechanism for pushing the punch into the die while rotating the punch. There was a problem that the cost of manufacturing was high.

The present invention is intended to solve the problems of the above-mentioned means for manufacturing a helical component. That is, the object of the present invention is to provide a helical planetary gear that can be easily, quickly and inexpensively manufactured by a simple means, that is, a punch having a complicated shape and a press machine that does not rotate but goes straight down. To provide a method for manufacturing a planetary gear and a mold used for the method.

[0007]

[Means for Solving the Problems]

a) In the method of manufacturing the helical planetary gear according to the present invention, the diameter D2 of the cylindrical gear material 2 is made substantially equal to the diameter D1 of the pitch circle P1 of the helical planetary gear 1 to be manufactured ( 1 and 3),

The gear material 2 is replaced with the pitch circle P of the gear 1.
With a pitch circle P3 of diameter D3 which is approximately equal to the diameter D1 of 1,
The recessed line 8 for forming the teeth 5 of the gear 1 and the protruding line 8 for forming the tooth groove 6 are engaged with the die 3 formed in a helical shape from the inlet,

By pressing the gear material 2 with the punch 4 and press-fitting it into the die 3, the gear material 2 is rotated along the helical recesses 7 and 8 in the die 3 while the recesses are in between. The helical tooth 5 and tooth groove 6 are plastically formed by the line 7 and the convex line 8 (see FIG. 1),

After that, the plastic product 10 is pushed out from the other opening of the die 3.

B) The mold used for manufacturing the helical planetary gear according to the present invention is a set of a die 3 and a punch 4.
And consists of

The die 3 has a pitch circle P3 having a diameter D3 substantially equal to the diameter D1 of the pitch circle P1 of the helical planetary gear 1 to be manufactured on the inner peripheral portion thereof for forming the teeth 5 of the gear 1. The ridge 8 and the ridge 7 for forming the tooth groove 6 are formed in a helical shape, and a funnel-shaped portion 9 having a larger diameter is formed in the vicinity of the inlet of the upper portion toward the upper portion (see FIGS. 1 and 4).
・ See Fig. 5),

On the other hand, the punch 4 is of a cylindrical shape that descends without rotating, and has a diameter D4 of the ridge 8 of the die 3.
It is formed to be slightly smaller than the diameter of the circle A formed by connecting the tips of the two (see FIG. 1).

In the above structure, the cylindrical gear material 2
Is of a diameter D2 which is substantially equal to the diameter D1 of the pitch circle P1 of the helical planetary gear 1 to be manufactured, and the helical groove 7 and ridge 8 on the inner periphery of the die 3 are also the same as above. The gear circle 1 is formed into a pitch circle P3 having a diameter D3 substantially equal to the diameter D1 of the pitch circle P1.

This is because when the gear material 2 is plastically deformed in the die 3, the ridge 8 of the die 3 forms the concave volume of the gear material 2 when the tooth material 6 is recessed, and the die volume. This is to make the projected volume when the gear material 2 is projected by the recessed line 7 of 3 and the teeth 5 are formed to be substantially equal. In the above description, the diameter D1 of the pitch circle P1 of the gear 1 does not mean the diameter of the pitch circle in a strict sense, but the diameter of the circle such that the two volume integrals are equal. .

Further, the diameter D of the pitch circle P1 of the gear 1
In other words, 1 is almost the same as the diameter of the tip circle and the diameter of the root circle of the helical planetary gear 1 to be manufactured.

On the other hand, the punch 4 has a cylindrical shape having a diameter D4 slightly smaller than the diameter of a circle A formed by connecting the tips of the projections 8 of the die 3,
This is to enable the punch 4 to be engaged in the die 3. The plastic molded product 10 is preferably pushed out from the die 3 by engaging the next gear material 2 with the punch 4 but may be pushed out by the punch 4 to the end.

In the figure, 11 is a groove on the outer periphery of the helical planetary gear 1, and 12 is a central hole.

[0019]

The method of manufacturing a planetary gear according to the present invention is
It is performed as follows. Cylindrical gear material 2 used here
Is the same as the diameter D1 of the pitch circle P1 of the helical planetary gear 1 to be manufactured. As described above, when the gear material 2 is plastically deformed in the die 3, the convex volume 8 of the die 3 causes the recessed tooth volume 6 of the gear material 2 to be formed, and the die volume. This is to make the projected volume when the gear material 2 is projected by the recessed line 7 of 3 and the teeth 5 are formed to be substantially equal.

The cylindrical gear material 2 is engaged from the entrance of the die 3. Since the vicinity of the entrance of the die 3 is formed in the funnel-shaped portion 9, the engagement can be smoothly performed.

Next, the gear blank 2 is pushed down by the non-rotating punch 4. With this, the gear material 2 is gradually press-fitted into the die 3, and the die 3 is provided with the projections 8 for forming the teeth 5 of the helical planetary gear 1 and the tooth grooves 6 for forming as described above. The groove 7 is formed in a helical shape.

Therefore, when the gear material 2 is press-fitted into the die 3, the helical recess 7 of the die 3 is pressed.
And it will be sent to the back while rotating along the ridge 8. While being pushed down while rotating in the die 3, the gear material 2 is recessed by the convex strip 8 of the die 3, and that portion is plastically formed in the helical tooth groove 6 and projected by the concave strip 7. That portion is plastically formed on the helical tooth 5.

During the above plastic forming, the gear material 2 has a diameter D2 which is substantially equal to the diameter D1 of the pitch circle P1 of the helical planetary gear 1, and the concave line 7 and the convex line 8 of the die 3 are also the above. Since the pitch circle P3 has a diameter D3 which is almost equal to the diameter D1 of the pitch circle P1 of the gear 1, the tooth groove 6 formed by denting the gear blank 2 by the ridge 8 of the die 3 is formed.
And the tooth 5 formed by the protrusions 7 of the die 3 protrudingly formed are substantially equal to each other.

The plastic-formed product 10 having the helical teeth 5 and the tooth grooves 6 formed as described above is pushed by the gear material 2 which is then engaged and press-fitted, and pushed out from the other outlet of the die 3. Be done. After that, the recessed groove 11 and the central hole 12 for the shaft support may be cut and formed in the plastic molded product 10 toward the center of the outer periphery. As a result, the helical planetary gear having a predetermined shape and size to be manufactured can be manufactured easily, quickly and inexpensively.

[0025]

1 to 7 show an embodiment of the present invention. Reference numeral 2 denotes a cylindrical gear material, which is made of, for example, stainless steel or other steel material, and whose diameter D2 is substantially equal to the diameter D1 of the pitch circle P1 of the helical planetary gear 1 to be manufactured. To use.

A die 3 has a pitch circle P3 having a diameter D3 substantially equal to the diameter D1 of the pitch circle P1 of the helical planetary gear 1 to be manufactured, on the inner peripheral portion thereof.
Then, the concave stripe 7 for forming the teeth 5 of the gear 1 and the convex stripe 8 for forming the tooth groove 6 are formed in a helical shape.

A funnel-shaped portion 9 having a larger diameter is formed near the entrance of the upper portion of the die 3, and the inner peripheral portion of the funnel-shaped portion 9 has a recessed portion following the helical recessed portion 7 and the protruding portion 8. The ridge and the ridge are formed.

Reference numeral 4 denotes a punch, which has a cylindrical shape,
The diameter D4 of the die 3 is slightly smaller than the diameter of a circle A formed by connecting the ridges 8 of the die 3 so as to be engageable with the die 3. Further, the movement of the punch 4 may be a non-rotating descent.

The columnar gear material 2 does not receive the lower surface when it is press-fitted into the die 3. However, in order to prevent the occurrence of settling and burrs during plastic deformation, the gear material 2 is not shown. The lower surface may be received by a cylindrical receiving member similar to the punch 4.

[0030]

As is apparent from the above, the method of manufacturing the planetary gear according to the present invention and the mold used for the method are as follows.
It has the following effects.

That is, in the conventional means for manufacturing a helical part, a complicated shape having helical recesses and protrusions is used not only on the inner periphery of the die but also on the outer periphery of the punch. It is necessary that the punch has a complicated shape and the die cost is high, and the punch needs to be lowered while rotating, and the press machine also needs to have such a mechanism. Therefore, the manufacturing cost of a product having a helical groove / ridge is high.

On the other hand, according to the present invention, the simple means as described above, that is, the inner peripheral portion of the die has a helical shape, but the punch has a predetermined cylindrical shape only by dropping it in a linear shape. Shaped planetary gears can be manufactured. Therefore, the die cost is low and the press machine does not need to rotate the punch, so that the helical planetary gear can be manufactured easily, quickly and at low cost by cold forging.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view showing an example of an implementation state of a method for manufacturing a planetary gear according to the present invention.

FIG. 2 is a front view of a helical planetary gear to be manufactured.

FIG. 3 is the helical planetary gear I shown in FIG.
FIG. 6 is an end view taken along line I.

FIG. 4 is a vertical sectional front view of a die used in the example of the implementation state shown in FIG.

5 is an end view taken along line II-II of the die shown in FIG.

FIG. 6 is a front view of the plastically formed product extruded from the die according to the example of the embodiment shown in FIG.

FIG. 7 is an end view taken along line III-III of the plastically formed product shown in FIG.

[Explanation of symbols]

1-helical planetary gear 2-gear material 3-die 4-punch 5-tooth 6-tooth groove 7-concave line 8-convex line 9-funnel-shaped part 10-plastic formed product 11-concave groove 12-central hole P1-Pitch circle P3-Pitch circle A-Circle formed by connecting the tips of ridges D1-Diameter D2-Diameter D3-Diameter D4-Diameter

Claims (2)

[Claims] 1. A pitch circle P of a helical planetary gear 1 to be manufactured, having a diameter D2 of a cylindrical gear material 2.
It is assumed that the gear material 2 is almost equal to the diameter D1 of 1 and the diameter D1 of the pitch circle P1 of the gear 1 is
With a pitch circle P3 having a diameter D3 substantially equal to, a toothed groove 7 for forming the teeth 5 and a toothed groove 8 for forming the tooth groove 6 are engaged with the die 3 having a helical shape from the inlet, By pressing the gear material 2 into the die 3 with the punch 4, the gear material 2 is rotated along the helical groove 7 and the groove 8 in the die 3 while the groove 7 and the groove 8 are interposed therebetween.
A helical planetary gear manufacturing method in which the helical tooth 5 and the tooth groove 6 corresponding to the above are plastically formed, and then the plastically formed product 10 is extruded from the other opening of the die 3. 2. A set of a die 3 and a punch 4, the die 3 having an inner peripheral portion having a diameter D3 substantially equal to the diameter D1 of the pitch circle P1 of the helical planetary gear 1 to be manufactured. On the pitch circle P3, a concave ridge 7 for forming the tooth 5 of the gear 1 and a convex ridge 8 for forming the tooth groove 6 are formed in a helical shape, and a funnel shape having a larger diameter toward the upper portion near the inlet of the upper portion. On the other hand, the punch 4 has a cylindrical shape that descends without rotation, and its diameter D4 is smaller than the diameter of a circle A formed by connecting the tips of the ridges 8 of the die 3 to each other. A mold used to manufacture helical planetary gears that are made slightly smaller.