JPH106135A - Gear machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear cutting tool in general use so that teeth with different dimentional items can be formed without changing the gear cutting tool. SOLUTION: A reference gear face GF1 is formed on a workpiece W and a gear face GF2 opposed to the reference gear face GF1 by relatively moving a cutting tool and the workpiece W toward the thickness of gear is formed to cut gear grooves (a) at preset spaces in the workpiece W. To form gear grooves (b) in place between the gear grooves (a), (a) formed in the pitches of a gear cutting edge 2, the gear cutting edge 2 and the workpiece W are relatively moved as predetermined and a reference gear cutting process and a shift gear cutting process are taken again, so that teeth with pitches P2 different from the pitches P1 of the gear cutting edge 2 are formed. Then, the face ends of the formed teeth are chamfered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing teeth for forming gears and racks (hereinafter referred to as gears) by forming teeth on a workpiece, and further to chamfering the formed teeth. The present invention relates to a method of processing a tooth to be processed.

[0002]

2. Description of the Related Art To form teeth on a workpiece to manufacture gears or the like, generally, a tooth cutting method using a hob, a pinion rack, a rack cutter, or a shaping method using a milling cutter or the like. Etc. Further, in a gear or the like having teeth formed thereon, a chamfering process is performed on a tooth width end face or a tooth tip face depending on the purpose of use. Conventionally, chamfering of a tooth width or an end face of a tooth tip is performed on a formed tooth using an end mill cutter, a milling cutter, a grinding wheel, or a dedicated chamfer hob or the like.

A conventional gear cutting tool is disclosed in
As disclosed in JP-A-1222993, a gear hob in which a hob having a tooth cutting edge portion for performing normal gear cutting and a hob having a tooth width end face chamfering edge portion are arranged in parallel. Are known.

In this gear hob, when the cycle of cutting the tooth profile by the gear cutting edge is completed, the hob shaft enters a moving cycle, and then enters a cycle of chamfering by the chamfering edge. Thus, the gear cutting and the chamfering of the end face can be continuously performed in one gear cutting cycle.

[0005]

However, in the conventional tooth processing described above, even if the pressure angle is the same as that of the module, if the tooth thickness, the tooth height, the chamfer of the tooth tip, etc. are different, the same tooth cutting tool is used. Therefore, a gear cutting tool according to the specifications of each gear to be formed is required. In other words, the gear cutting tool used in the conventional tooth machining method is not versatile, and when the specifications of the teeth to be formed are changed or newly designed, the gear cutting tool is replaced or a new gear cutting is performed. Need to make tools. Therefore, in order to increase tool costs by manufacturing various hobbing tools, increase man-hours and storage space for various hobbing tools, and to newly manufacture hobbing tools adapted to specifications such as gears. However, there is a problem that the time required for manufacturing gears and the like increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to make a tooth cutting tool versatile and to form teeth having different specifications without changing the tooth cutting tool. An object of the present invention is to provide a method of processing a tooth.

It is a further object of the present invention to provide a method of processing a tooth which can perform desired chamfering on a tooth formed as required, in addition to the above objects.

[0008]

The invention according to claim 1 is
In order to achieve the above object, a reference gear cutting step of forming a reference tooth surface on a workpiece, and forming a tooth surface opposed to the reference tooth surface by relatively moving a cutting tool and the workpiece in a tooth thickness direction. In the tooth machining method of forming teeth on the workpiece by the shift gear cutting step, a step of moving the cutting tool and the workpiece relative to each other by a predetermined pitch is performed, and teeth having a pitch different from the pitch of the cutting tool are formed on the workpiece. A method of processing a tooth, characterized by forming.

According to a second aspect of the present invention, there is provided a method of processing a tooth according to the first aspect of the present invention, wherein the method further comprises the step of chamfering the formed tooth into a predetermined shape. It is a feature.

In the invention according to the first aspect, the blade is formed with a tooth thickness that is sufficiently narrower than a gap between a tooth surface serving as a reference formed on the workpiece and a tooth surface facing the reference tooth surface. Forming a tooth space having a reference tooth surface on the workpiece, relatively moving the cutting tool and the workpiece in the tooth thickness direction, and forming a tooth space having a tooth surface facing the reference tooth surface first. It is formed so as to be continuous, and the teeth are formed at the same pitch as the pitch of the cutting tool.
Next, a step of relatively moving the cutting tool and the workpiece at a predetermined pitch is performed, and the reference tooth is formed so as to form a tooth groove at a predetermined position between the tooth grooves formed at the pitch of the cutting tool earlier. By performing the cutting step and the shift gear cutting step again, a tooth groove having a pitch different from the pitch of the cutting tool is formed on the workpiece, and the desired specification teeth are formed.

In the invention according to the second aspect, the tooth tip is chamfered to a desired shape by relatively moving the formed teeth and the chamfering blade by a predetermined amount.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a tooth processing method according to the present invention will be described in detail with reference to the drawings, in which a tooth is formed by a hob. The same reference numerals in the drawings denote the same or corresponding parts.

First, the hob 1 used in the tooth processing method according to the present invention will be described with reference to FIGS. The hob 1 is mounted on a hob shaft (not shown) of a hobbing machine, is driven to rotate around the shaft, and the work W
Is controlled so as to form a tooth G in FIG.
As shown in FIG. 5, the workpiece W is cut to form a tooth G (see FIG. 2).
A cutting hob 1A having a cutting edge 2 for gear cutting as a cutting tool for forming a bevel, and a chamfering hob 1B having a cutting edge 3 for chamfering as a cutting tool for chamfering the tip of the formed tooth G. And Gear cutting hob 1A and chamfer hob 1
B is a chamfer hob 1 for gear cutting on a workpiece.
B is coaxially arranged in parallel with the hob shaft with a predetermined distance L so that B does not interfere with the hobbing hob 1A during chamfering. As shown in FIG. 2, the tooth thickness T1 on the gear cutting pitch line of the gear cutting edge 2 is determined by the workpiece W
Is formed sufficiently narrower than the interval T2 on the gear-cutting pitch line or the gear-cutting pitch circle between the tooth surface serving as a reference and the tooth surface facing the tooth surface.

The cutting blades 2 of the gear cutting hob 1A are arranged at a predetermined pitch P1 and a predetermined lead angle.
The chamfering cutting edges 3 of the chamfering hob 1B are formed at an angle β necessary for chamfering a desired tooth tip (see FIG. 6), and are arranged at the same pitch P1 and lead angle as the gear cutting edge 2. I have.

Next, an embodiment of a tooth processing method according to the present invention using the hob 1 configured as described above will be described with reference to FIG.
7 will be described with reference to FIG. The tooth processing method according to the present invention generally includes a reference tooth cutting step of forming a reference tooth surface GF1 on a workpiece W, and a cutting tool (gear cutting edge 2) and a workpiece W having a tooth thickness. A shift gear cutting process in which the tooth surface GF2 facing the reference tooth surface GF1 is relatively moved in the direction, and a process in which the cutting tool (gear cutting blade 2) and the workpiece W are relatively moved by a predetermined amount. This includes forming teeth G having a pitch different from the pitch P1 of the cutting tool (the cutting edge 2 for gear cutting) on the workpiece W, and further includes a chamfering step of the formed teeth G.

FIGS. 3 (a), 3 (b) and 3 (c) show predetermined teeth G. FIG.
FIG. 3 is a schematic view showing a reference gear cutting process and a shift gear cutting process for forming a gear. FIG.
As shown in (a), the tooth thickness T1 is on a gear cutting pitch line or a gear cutting pitch circle of a tooth surface GF1 serving as a reference formed on the workpiece W and a tooth surface GF2 facing the reference tooth surface GF1. the gear cutting for cutting edge 2 which is formed sufficiently narrower than the interval T2 (see FIG. 2), cutting a tooth slot a ₁ tooth surfaces GF1 as a reference to the workpiece W is formed.

Next, in the shift gear cutting step, FIG.
As shown in a gear cutting for cutting edge 2 a workpiece W is relatively moved in the tooth thickness direction, cutting a tooth slot a ₂ consecutive cutting machined tooth slot a ₁ by the reference gear cutting process . And
In this embodiment, as shown in FIG.
Further, the cutting edge 2 for gear cutting and the workpiece W are relatively moved in the tooth thickness direction, and the cutting edge 2 for tooth cutting causes the tooth surface GF1 serving as a reference and the tooth surface GF2 facing the reference tooth surface GF1 to move. Are set at predetermined intervals, so that the tooth space a ₁ cut in the reference gear cutting step and the tooth space a ₂ and the tooth space a
Cutting ₃

FIGS. 4A and 4B show a cutting blade 2 for gear cutting.
And the workpiece W are relatively moved by a predetermined amount and the gear cutting hob 1A
FIG. 7 is an explanatory view showing a step of forming teeth G having a pitch different from the pitch P1 of the cutting edge 2 for gear cutting on the workpiece W;
As shown in FIG. 4 (a), when the reference gear cutting process and the shift gear cutting process are completed and the tooth grooves a having the same pitch as the gear cutting edge 2 are formed, then as shown in FIG. 4 (b). First, for example, 1/2, 1/3, etc., between the tooth grooves a formed by the pitch of the cutting edge 2 for gear cutting (FIG. 4)
(1/2 position in the example shown in (b)) The tooth cutting edge 2 and the workpiece W are formed so that the tooth space b is formed at a predetermined position.
Is relatively moved by a predetermined amount, and the reference gear cutting step and the shift gear cutting step are performed again, so that the pitch P different from the pitch P1 of the gear cutting edge 2 is changed.
Form two teeth. In this way, by repeatedly moving the cutting edge 2 for gear cutting and the workpiece W by a predetermined amount and repeating the reference gear cutting step and the shift gear cutting step, the desired pitch, tooth thickness, etc. The specification tooth G is formed.

In the chamfering step, the chamfering hob 1B on which the chamfering cutting blades 3 are arranged at the same pitch P1 and the advancing angle as the gear-cutting cutting blades 2 is driven to rotate around the axis, while FIG.
As shown in the figure, the workpiece W is brought close to the workpiece W by a predetermined amount K1,
The tip of the tooth surface is chamfered to a desired shape. FIG. 7 is a partial perspective view showing a state in which chamfering is performed on the tooth surface tips H of the gear teeth G. In addition, depending on the height of the formed tooth G or the shape of the chamfering process performed on the tooth surface tip H, as shown in FIG. 6, the chamfer hob 1B is moved in the axial direction by K2 to obtain a desired tooth surface tip. Chamfering can also be performed.

In this embodiment, the tooth processing method according to the present invention has been described by using the case where a gear is formed from the workpiece W using the hob 1, but the present invention is not limited to this. . That is, the method for processing teeth according to the present invention can be used not only for forming gears but also for forming rack teeth. Further, in the tooth processing method according to the present invention, as a tool instead of the hob 1, a tooth surface GF1 serving as a reference having a tooth thickness formed on the workpiece W and a tooth surface GF2 facing the reference tooth surface GF1 are provided. The cutting edge 2 for gear cutting formed sufficiently narrower than the interval of
If they are arranged at a pitch P1 that is an integral multiple of 2, a rack cutter, a pinion cutter, or the like can be used according to the workpiece W on which the teeth G are formed.

[0021]

According to the first aspect of the present invention, the tooth thickness is formed to be sufficiently smaller than the distance between the tooth surface serving as a reference formed on the workpiece and the tooth surface facing the reference tooth surface. The tooth tool is used to form a reference tooth flank on the workpiece, and the tool and the workpiece are relatively moved in the tooth thickness direction to form a tooth flank opposite to the reference tooth flank, thereby forming a tooth space. By moving the workpiece and the workpiece relative to each other by a predetermined pitch and forming a tooth groove in a place different from the previously formed tooth groove, teeth having a pitch different from the pitch of the cutting tool can be formed on the workpiece. Therefore, a plurality of types of teeth can be formed with one cutting tool without changing the gear cutting tool.

Further, according to the second aspect of the present invention, it is possible to chamfer a tooth tip according to a formed tooth or a desired chamfered shape.

[Brief description of the drawings]

FIG. 1 is a view showing a hob used in a tooth processing method according to the present invention.

FIG. 2 is an explanatory diagram showing the relationship between the tooth thickness of a cutting blade for gear cutting of a gear cutting hob, and a distance between a tooth surface serving as a reference formed on a workpiece and a tooth surface facing the reference tooth surface. It is.

FIG. 3 is a schematic diagram showing a reference gear cutting process and a shift gear cutting process for forming a predetermined tooth.

FIG. 4 is an explanatory view showing a process of forming a tooth on the workpiece W having a pitch different from the pitch of the cutting edge of the gear cutting hob by relatively moving the cutting tool and the workpiece W by a predetermined amount. .

FIG. 5 performs a chamfering step by rotating a chamfering hob around an axis and approaching a workpiece by a predetermined amount.

FIG. 6: By moving the chamfer hob in the axial direction,
It is explanatory drawing in the case of chamfering.

FIG. 7 is a partial perspective view of a gear in which chamfering processing is performed on a tooth tip surface of a formed tooth.

[Description of sign]

DESCRIPTION OF SYMBOLS 1 Hob 2 Cutting edge for cutting (blade tool) 3 Cutting edge for chamfering G Teeth a, b Tooth groove GF1 Reference tooth surface GF2 Tooth surface facing reference tooth surface T1 Tooth of cutting tooth for tooth cutting Tooth thickness on cutting pitch line T2 Distance between the reference tooth surface and the opposing tooth surface on the tooth cutting pitch line or on the tooth cutting pitch circle P1 The pitch of the cutting blade for gear cutting P2 The pitch of the formed teeth

Claims (2)

[Claims] 1. A reference gear cutting process for forming a reference tooth surface on a workpiece, and a shift tooth for forming a tooth surface facing the reference tooth surface by relatively moving a cutting tool and the workpiece in a tooth thickness direction. A tooth processing method for forming teeth on a workpiece by cutting, including a step of moving the cutting tool and the workpiece relative to each other by a predetermined pitch, forming teeth on the workpiece with a pitch different from the pitch of the cutting tool. A tooth processing method characterized by the above-mentioned. 2. The method according to claim 1, further comprising a chamfering step of chamfering the formed teeth into a predetermined shape.