JP2002028821A - Machining method and machining device for gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machining method and a machining device for a gear that are simple in operation and can manufacture a multitude of uniform gears. SOLUTION: For the manufacture of a gear Y from bar stock X with a cylindrical periphery through gear cutting on the bar stock periphery by a hob cutter H, the machining method and device for a gear supports the bar stock X for axial rotation and axial movement, feeds the bar stock X on axially while rotating it synchronously with the rotation of the hob cutter H and at the same time provides gear cutting by the hob cutter H on the bar stock periphery to form a spur gear Y with a necessary number of teeth, and cuts every given axial length off from the bar stock X to machine the gear Y. The bar stock X may be fed on axially while rotated out of rotational synchronism to a given extent about the axis, when the hob H provides gear cutting for a helical gear on the bar stock periphery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for mass-producing gears, and more particularly to a method and apparatus for mass-producing uniform gears from a rod having a cylindrical peripheral surface.

[0002]

2. Description of the Related Art Generally, a gear is manufactured by cutting a bar having a cylindrical peripheral surface by a predetermined length along an axial direction to form a thick disk-shaped material, and performing gear cutting around the disk-shaped material. And

Conventionally, as shown in FIG. 3, a through hole is provided in the center axis of a disk-shaped material X, inserted into a mounting shaft of a jig 1, tightened and fixed by a nut 2, and then a collet 3 and an arbor. It is positioned between the four and is subjected to gear cutting with a hob H.

[0004]

In this operation, the gear is set to one.
This must be performed every time an individual unit is manufactured, and there is a trouble of repeatedly mounting the nut 2 to the jig 1 by tightening and positioning the collet 3 and the arbor 4. In addition, since the operation of cutting the teeth for each gear is performed, in a strict sense, each gear has a different size and shape, and the uniformity of the product requires skill of an operator.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above points, and has as its object to provide a gear processing method and apparatus capable of easily producing a large number of uniform gears.

[0006]

In order to achieve the above object, according to the present invention, a bar having a cylindrical peripheral surface according to claim 1 is used, and the outer peripheral surface of the rod is subjected to gear cutting by a hob cutter. In the method of manufacturing a gear by doing, the bar is rotatable around the axis, supported movably in the axial direction, while sending the bar in the axial direction with rotation synchronized with the rotation of the hob. Forming a spur gear having a required number of teeth by performing gear cutting with a hob cutter on the outer periphery of the bar, and cutting the bar at predetermined lengths in the axial direction to process the gear. 3. A method of manufacturing a gear, comprising: using a bar having a cylindrical peripheral surface according to claim 2, and performing gear cutting by a hob cutter on an outer periphery of the bar, wherein the shaft is Rotatable in the circumferential direction, axial direction The rod is movably supported, and the rod is sent out in a predetermined amount in the axial direction while rotating the rod in a direction around the axis by a predetermined amount while being synchronized with the rotation of the rod. The gear processing method according to claim 3, wherein a helical gear having a required number of teeth is formed, and the bar is cut at a predetermined length in the axial direction to process the gear. Means for rotatably supporting a rod having a cylindrical peripheral surface in the direction around the axis and movably in the axial direction; means for feeding the rod in the axial direction; and the rod in synchronization with the rotation of the hob cutter. 5. A gear processing device comprising: means for rotating a shaft in a direction around an axis; and means for cutting a bar cut by the hob cutter at desired axial lengths, and the cylindrical peripheral surface according to claim 4. Can be rotated around the axis of the bar having Means for movably supporting the rod, means for feeding the rod in a predetermined amount in the axial direction, means for rotating the rod in a direction around the axis by shifting the rotation cycle of the hob cutter by a predetermined amount, and An object of the present invention is to provide a gear processing apparatus having means for cutting a bar material, which has been gear-cut by a hob cutter, at desired axial lengths.

[0007]

FIG. 1 shows a first embodiment of the present invention, in which a spur gear is manufactured. FIG. 1 shows various states along the progress of the steps of hobbing the gears from the left side to the right side of the figure, necessary heat treatment, measurement, and finishing.

That is, at the position a, the bar X is driven by rotation synchronized with the hob H. At the next position b, the drive source 11 feeds the bar X in the axial direction. Also, position c
In this example, the bar X is supported so as to be rotatable around the axis and to be axially feedable. In FIG. 1, the bar X is supported at only one place, but usually it is supported at a plurality of places.
Further, at the position d, a gear is formed on the outer periphery of the bar X by a cutting tool, that is, the hob H. Next, at positions e and f,
If necessary, bake, measure, and further process the outer periphery.
At the position g, grinding, polishing, and the like corresponding to finishing are performed. At the position h, molding, measurement, and the like are performed. Then, at the position i, a product Y is cut out from a bar X having a cylindrical peripheral surface.

In the present invention, a bar having a cylindrical peripheral surface is used as it is, without cutting, for gear cutting. For this purpose, the bar X is supported so as to be rotatable around the axis and to be able to be sent out in the axial direction, and is fed along the axis with rotation synchronized with the hob H by the drive source 11 arranged at the position b. Can be

The bar X is sent in the axial direction with a predetermined rotation synchronized with the rotation of the hob H, and a gear is formed by the hob H on the outer peripheral surface at a position d as the bar X is fed. Is done.

Then, when reaching the positions e and f, if necessary, baking treatment, measurement, peripheral processing, etc. are performed. further,
When the position g is reached, finishing processing, that is, grinding and polishing processing is performed. At the position h, molding and measurement are performed.

[0012] After the gears are formed around the entire circumference of the bar X in this way, the tip of the bar X is fed out to the position i and cut to form one gear. The bar X is sequentially sent out to the position i and cut to form a gear.

FIG. 2 shows another embodiment of the present invention, in which a helical gear is manufactured. In this example, the bar X is fed in the axial direction, and at the same time, the synchronization of the rotation around the axis is shifted by the amount of the helical gear.

As a result, although not shown in FIG. 2, the hob H creates a helical gear on the outer periphery of the bar X. Other configurations and operations are the same as those of the embodiment shown in FIG.

(Application Example) The gear manufactured according to the present invention has a disk shape and a shape in which the gear is cut on the outer periphery. By joining a shaft to the center of the gear, for example, a gear shaft for an electric motor can be formed.

This is a technique used when manufacturing a valve of an internal combustion engine, that is, by rotating at least one of an umbrella portion and a shaft portion of a valve to provide a considerable relative speed difference between the two. It is sufficient to use a friction welding method or the like in which the two are firmly joined by pressing.

According to this method, since the dissimilar metals are easily joined, the gear portion can be hardened and the shaft portion can be made of pure iron. As a result, if the gear of the present invention is used as a reduction gear of a motor, a motor having less leakage magnetic flux can be configured. And as the gear of the motor,
Good gear precision and low surface roughness are required to improve energy transmission efficiency and reduce noise, and the gear of the present invention can easily meet this requirement.

The joining is performed by laser welding, light beam welding,
Welding, brazing and press fitting may be used.

[0019]

According to the present invention, as described above, the outer periphery of a bar having a cylindrical peripheral surface is gear-cut while being fed in the axial direction, and then the gear is formed by cutting. A gear that has been made uniform for each bar can be manufactured.

The spur gear can be formed by cutting the rod while rotating the bar in the axial direction in synchronization with the rotation of the hob and feeding the rod in the axial direction. A helical gear can be formed by rotating the motor while shifting the synchronization by a fixed amount.

Further, by appropriately selecting a rod having a cylindrical peripheral surface and a hob, new gears can be mass-produced quickly in response to changes in gear specifications.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of the present invention.

FIG. 2 is an explanatory view showing another embodiment of the present invention.

FIG. 3 is an explanatory view showing a conventional gear forming method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Jig 2 Nut 3 Collet 4 Arbor 11 Drive source 12 Rotary encoder 13 Burning, measurement, processing, etc. 14 Burning, measurement, processing, etc. 15 Finishing, grinding, etc. 16 Forming, measurement, etc. H Hob X Bar Y Product

Claims (4)

[Claims] 1. A method of manufacturing a gear by using a bar having a cylindrical peripheral surface and performing gear cutting by a hob cutter on the outer peripheral surface of the rod, wherein the rod is rotatable around an axis. The number of teeth required by performing gear cutting with a hob cutter on the outer circumference of the bar while feeding the bar in the axial direction with rotation synchronized with the rotation of the hob while supporting the bar so as to be movable in the axial direction. Forming a spur gear having the following formula: and cutting the bar at predetermined axial lengths to process the gear. 2. A method of manufacturing a gear by using a bar having a cylindrical peripheral surface and performing gear cutting with a hob cutter on the outer periphery of the bar, wherein the bar is rotatable around its axis. The rod is supported so as to be movable in the axial direction, and the rod is sent out by a predetermined amount in the axial direction while rotating the rod in a direction around the axis by a predetermined amount while being synchronized with the rotation thereof. A gear processing method comprising: forming a helical gear having a required number of teeth by performing processing; and cutting the bar at predetermined axial lengths to process the gear. 3. A means for supporting a rod having a cylindrical peripheral surface so as to be rotatable around the axis and to be movable in the axial direction; a means for feeding the rod in the axial direction; and synchronously with the rotation of the hob cutter. A gear processing device comprising: means for rotating the bar in a direction around an axis; and means for cutting the bar cut by the hob cutter into desired axial lengths. 4. A means for supporting a rod having a cylindrical peripheral surface so as to be rotatable around the axis and to be movable in the axial direction, means for feeding the rod in a predetermined amount in the axial direction, and for rotating the hob cutter. A gear processing device comprising: means for rotating the bar in the direction around the axis by shifting the rotation cycle by a predetermined amount; and means for cutting the bar cut by the hob cutter into desired axial lengths. .