JPH08103845A - Production of gear - Google Patents

Abstract

PURPOSE: To excellently shape a tooth by pre-forming a recessed part to assist building-up of the tooth on the end face of the direction of tooth width. CONSTITUTION: The tooth part G of a gear is built up with a die and formed in a forging process, a heading process and a sizing process. Then, a recessed groove 13 is formed in a recessed state on the end face of the direction of tooth width along the dedendum circle, and a recessed part 14 projecting to the outer circumference side than the dedendum circle is formed in a recessed state on each tooth part G continuing to the recessed groove 13. The recessed part 14 to be formed on each tooth part G can be set so that the thickness against the line of external diameter of the tooth part G is made, for example, more than 1.5mm, if such recessed groove 13 and recessed part 14 are formed, building-up with the die can be assisted more excellently and lightening of the gear can be made. In such a way, the gear having the tooth shape with large strength and the gear of light weight can be produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear manufacturing method.

[0002]

2. Description of the Related Art Conventionally, the cross-sectional contour of the tooth surface of a gear has been standardized as shown in FIG.
A root 1 is formed along a root circle 6 and a tip 5 is formed along a tip circle 8, which is generally formed by a curve based on a tooth profile creation theory such as an involute curve A. Conventionally, a tooth profile based on such a tooth profile generation theory is formed by cutting with a gear cutting tool. That is, in the conventional art, the tooth profile of the gear is uniquely determined by the gear cutting tool, and the strength of the tooth profile is naturally determined by the tooth profile. The cutting method has a problem that it is difficult.

[0003]

The present invention has been devised in view of the above problems of the prior art, and includes a forging method, a forging method,
The purpose is not to provide a manufacturing method that can obtain a gear with a tooth profile that is not bound by the conventional tooth profile theory by the sizing method, etc. The summary is a forging method, a forging method, a sizing method, etc. When forming the raised portion, it is necessary to previously form a concave portion on the end face in the tooth width direction of the tooth portion to promote the raised tooth.

[0004]

[Function] Since the concave portion is previously formed on the end face in the width direction of the tooth portion, when the tooth portion is formed in a raised shape by the die by the forging method, the pressure forming method, the sizing method, etc., the previously formed concave portion is It plays a role of facilitating the build-up, and the build-up of the teeth is favorably performed by the mold, and the fiber flow inside the teeth is also formed smoothly.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. INDUSTRIAL APPLICABILITY The present invention is applicable to super gears having general involute curves, helical gears, hypoid gears, bevel gears, clutch gears, splines, and the like, and is also applicable to gears having trochoidal curves. FIG. 1 shows an example of a die 10 for shaping the gear of the present example. The gear of the present example forms a tooth profile by a forging method, a forging method or a sizing method using the die 10. The bottom portion 10a formed on the gear 10 forms the tooth bottom 1 of the gear, and the tooth surface is formed by the side surface portion 10b of the die 10 that continuously rises from the bottom portion 10a. Figure 1 by pressing
It can be formed by raising the teeth of the gear as described above. It is also possible to form a tooth profile by cutting in advance and then use the die 10 to form it by a forging method, a forging method, or a sizing method, which can be performed in cold, warm, or hot conditions.

In this example, as shown in the perspective view of FIG. 2 and the sectional view of FIG. 3, the recessed groove 11 is formed in advance on both end faces or one end face in the tooth width direction. Yes, this groove 11 is located closer to the center than the tooth circle 6
It can be formed along the tooth base circle 6, and if such a groove 11 is formed on the end face in the tooth width direction, the mold 1 can be formed.
When pressing with 0 to form a raised tooth portion, the groove 11
Promotes the build-up, and the build-up by the mold 10 is smoothly performed through the concave groove 11. If such a concave groove 11 is not formed, it is extremely strong at the early stage of the build-up of teeth. However, since the concave groove 11 favorably promotes the buildup of teeth, the pressing force of the die 10 can be reduced, and the die 10 can be manufactured.
Wear of the mold 10 is reduced, and the durability of the mold 10 can be improved. Further, the weight of the gear can be reduced by the concave groove 11.

Incidentally, the groove 11 may be changed to intermittent recesses 12, 12, 12 along the circumferential direction as shown in FIG. 4, and in the case of FIG. Recessed only in part 1
2, 12 and 12 are formed in a concave shape, respectively. In the case of FIG. 4 as well, during the build-up molding by the mold,
The concave portion 12 favorably promotes the buildup of teeth.

Next, FIG. 5 shows a modified example, in which an end face in the tooth width direction is formed with a recessed groove 13 along the root circle 6 and is formed continuously with the recessed groove 13. In each tooth portion, concave portions 14, 14, which protrude outward from the root circle 6,
Each of the concave portions 14 is formed in a concave shape. As shown in the side view of FIG. 6, the concave portion 14 formed on the end face of each tooth portion G has a thickness t with respect to the outer diameter line R of the tooth portion. For example, it can be set to 1.5 mm or more, and by forming the groove 13 and the groove 14 as described above, it is possible to more favorably promote the formation of teeth by the die 10 and reduce the weight of the gear. Can be achieved. As shown in FIG. 7, the concave groove 13 in FIG. 5 may be formed intermittently.

Further, FIG. 8 shows the clutch gears 20, 20,
The case where the gear 20 is integrated is shown. However, even in such a clutch gear integrated gear, the concave portions 14, 14, 14
The clutch gear 2 on the end face in the tooth width direction of each tooth G
If it is formed in the upper part of 0, the tooth part G can be satisfactorily formed by the forging method, the forging method, and the sizing method by the die 10, and the recesses 14, 14,
The formation of the raised teeth is facilitated through 14, and the formation of the tooth portion G is facilitated. Also, the intermittent recesses 14, 14
Then, since the portion of the stopper 21 in the clutch gear integrated gear is favorably left, it is possible to model the clutch gear integrated gear that can effectively exhibit the stopper function. Further, as shown in FIG. 9, the clutch gears 20, 20, 20
If the position of is shifted with respect to the tooth portion G, the concave portions 14, 14, 14
Can be formed into a large size, and as shown in FIG.
The recesses 14, 14, 14 may be formed on the end face in the tooth width direction of the tooth G on the side opposite to the clutch gear 20.

[0010]

The gear manufacturing method of the present invention comprises a forging method,
When forming the tooth part of the gear with a die by a press forming method, a sizing method, etc., it was decided to previously form a recess on the end face in the tooth width direction of the tooth part so as to promote the rising of the tooth. The concave portion will favorably promote the formation of the tooth portion when forming the tooth portion with a mold, and the tooth can be shaped well by smoothly forming the fiber flow inside the tooth surface. Unlike the conventional cutting method, it has an effect that it is possible to manufacture a gear having a tooth profile having a large strength which is not bound by the tooth profile theory and which is lightweight.

[Brief description of drawings]

FIG. 1 is an explanatory view of work when forming a tooth portion of a gear by a mold.

FIG. 2 is a perspective configuration view of a groove formed in the end face in advance.

FIG. 3 is a sectional configuration diagram of FIG. 2;

FIG. 4 is a perspective view of a main part of a gear having recessed portions formed in an end face in an intermittent manner.

FIG. 5 is a perspective view of a main part of a gear showing an example of modification of a recess on an end surface.

FIG. 6 is a side view of a main part of FIG.

FIG. 7 is a side view showing a configuration in which the concave portion of FIG. 5 is formed in an intermittent manner.

FIG. 8 is a perspective view of a main part in which a concave portion is formed on an end surface of the clutch gear integrated gear.

FIG. 9 is a perspective view of a main part in which a concave portion is formed on an end surface of the clutch gear integrated gear.

FIG. 10 is a perspective view of a main part in which a concave portion is formed on an end surface of the clutch gear integrated gear.

FIG. 11 is a tooth profile diagram based on a conventional involute curve.

[Explanation of symbols]

 G tooth portion t wall thickness 1 tooth bottom 10 mold 10b side surface portion 11 concave groove 12 concave portion 13 concave groove 14 concave portion 20 clutch gear

Claims (1)

[Claims] 1. When forming a tooth portion of a gear by a die using a forging method, a forging method, a sizing method, etc.,
A method for manufacturing a gear, characterized in that a recess is formed in advance on the end face in the tooth width direction of the tooth portion so as to promote the build up of the tooth.