JP-7855797-B2 - Method for chamfering gears, chamfering tool, and method for manufacturing a chamfering tool.

JP7855797B2JP 7855797 B2JP7855797 B2JP 7855797B2JP-7855797-B2

Inventors

美和幸志郎

Assignees

オーエスジー株式会社

Dates

Publication Date: 20260508
Application Date: 20230526

Claims (8)

A method for chamfering a gear, comprising a chamfering step of chamfering a gear having multiple teeth formed around a rotating axis using a chamfering tool that rotates around a tool axis, The multiple teeth have tooth surfaces which are surfaces facing the circumferential direction of the gear, Each of the tooth surfaces comprises the axial edge of the rotation axis, The chamfering tool comprises two or more cutting edges formed around the tool axis in a shape corresponding to the shape of the edge, Let K be an arbitrary integer, let Zw be the number of teeth, and let Zt be the number of cutting edges. The chamfering step is characterized in that, in a machining position in which the tool axis is positioned non-parallel to the rotation axis, the gear is rotated K・Zt/Zw around the rotation axis each time the chamfering tool is rotated once around the tool axis, so that the machining blades sequentially contact a plurality of edges to chamfer, and different machining blades are brought into contact with the tooth tip side and tooth root side of one edge to chamfer, as described in claim 1.
The method for chamfering a gear according to claim 1, characterized in that the machining position is such that the tool axis is located on a first virtual plane including the rotation axis.
The chamfering tool has a rake face that extends from the cutting edge toward the tool axis and faces forward in the rotational direction of the chamfering tool, The rake face and the cutting edge are located on a third virtual plane including the tool axis, The method for chamfering a gear according to claim 1, characterized in that the initial phase of the machining blade when it starts to rotate around the tool axis in the chamfering step is determined with reference to the rake face.
The chamfering tool used in the gear chamfering method according to claim 3 , The cutting edge is a portion with a radius smaller than the maximum radius of the chamfering tool, and is formed on the axial tip side of the chamfering tool. A chamfering tool characterized in that the rake face extends from the position where the cutting edge is formed toward the opposite side from the tip.
A method for chamfering a gear, comprising a chamfering step of chamfering a gear having multiple teeth formed around a rotating axis using a chamfering tool that rotates around a tool axis, The multiple teeth have tooth surfaces which are surfaces facing the circumferential direction of the gear, Each of the tooth surfaces comprises the axial edge of the rotation axis, The chamfering tool comprises at least one cutting edge formed around the tool axis in a shape corresponding to the shape of the edge, and a tip which is the end on one side of the tool axis in the axial direction. Let K be an arbitrary integer, let Zw be the number of teeth, and let Zt be the number of cutting edges. In the chamfering process, with the tool axis positioned non-parallel to the rotation axis, the gear is rotated K・Zt/Zw around the rotation axis each time the chamfering tool is rotated once around the tool axis, causing the cutting edge to sequentially contact multiple edges and perform chamfering. The aforementioned machining position is a state in which the tool axis, which is located on a first virtual plane including the rotation axis, is moved parallel to the first virtual plane in a direction perpendicular to the first virtual plane. A method for chamfering a gear, characterized in that the machining blade is formed from the tip of the chamfering tool toward the other end in the axial direction of the tool shaft , and the edge in the axial direction of the rotation shaft of the tooth root surface, which is the surface between a plurality of teeth, is chamfered at the tip side of the machining blade .
The method for chamfering a gear according to claim 5 , characterized in that the machining position is such that the tool axis is inclined with respect to a second virtual plane perpendicular to the rotation axis.
A chamfering tool used in a chamfering method in which a gear having multiple teeth formed around a rotating axis is chamfered with a machining blade provided on a chamfering tool that rotates around a tool axis, and the tool axis is positioned non-parallel to the rotating axis, and the rotation of the chamfering tool around the tool axis and the rotation of the gear around the rotating axis are synchronized, and the machining blade, which is formed in a shape corresponding to the shape of the edge, is sequentially brought into contact with the axial edge of the tooth surface of the multiple teeth on the rotating axis, to chamfer the edge. The chamfering tool comprises a cutting edge formed around the tool axis, The aforementioned blade portion is The front rake face of the chamfering tool facing forward in the direction of rotation, The rear surface of the chamfering tool facing the rear in the direction of rotation, It comprises a connecting surface that connects the radially outer edges of the front scoop surface and the rear surface , A chamfering tool characterized in that a pair of processing blades for chamfering the edges are formed by the intersection lines of the connecting surface and the front rake surface, and the intersection lines of the connecting surface and the rear surface .
A method for manufacturing a chamfering tool used in a chamfering method in which a gear having multiple teeth formed around a rotating shaft is chamfered by a chamfering tool that rotates around a tool axis , The multiple teeth have tooth surfaces which are surfaces facing the circumferential direction of the gear, Each of the tooth surfaces comprises the axial edge of the rotation axis, The chamfering tool comprises at least one cutting edge formed around the tool axis, The tool comprises a rake face extending from the cutting edge toward the tool axis and facing forward in the rotational direction of the chamfering tool. Let K be an arbitrary integer, let Zw be the number of teeth, and let Zt be the number of cutting edges. In the chamfering method described above, with the tool axis positioned non-parallel to the rotation axis in a machining position, each time the chamfering tool is rotated once around the tool axis, the gear is rotated K・Zt/Zw around the rotation axis, causing the machining blade to sequentially contact multiple edges to perform chamfering. The method for manufacturing the aforementioned chamfering tool is: A gear setting step of setting the shape of the gear, including the shape of the chamfered portion to be formed when the edge is chamfered, and the number of teeth Zw, A rotation surface setting step involves setting the shape of a virtual rotation surface that rotates around the tool axis in the direction of rotation of the chamfering tool, A condition setting step in which the initial phase of the rotating surface, the machining position, an arbitrary integer K, and the number of machining blades Zt set in the rotating surface setting step are set, Based on the settings of the condition setting step and the gear setting step, an acquisition step is performed to acquire the intersection lines of the rotation surface and the chamfered portion at each phase when the gear is rotated K・Zt/Zw around the rotation axis while rotating the rotation surface once around the tool axis from the initial phase in the machining position, A method for manufacturing a chamfering tool, comprising: a forming step of forming the chamfering tool by using a line tangent to a plurality of intersection lines obtained in the acquisition step as the machining blade, and using the rotating surface on the tool axis side of the machining blade as the rake face.

Description

This invention relates to a method for chamfering gears, a chamfering tool for chamfering gears, and a method for manufacturing the chamfering tool. A method for chamfering the tooth tips of each tooth of a gear is known (Patent Document 1). This method involves rotating a gear while simultaneously rotating a chamfering tool around a tool axis parallel to the gear's rotation axis. This chamfering tool has multiple tool teeth around its tool axis, and chamfering is performed by bringing the tips of these tool teeth into contact with the gear teeth. Japanese Unexamined Patent Publication No. 4-146022 This is a perspective view of a gear and a chamfering tool illustrating a method for chamfering gears in the first embodiment.(a) is a front view of the chamfering tool, and (b) is a bottom view of the chamfering tool as seen from the direction of arrow IIb in Figure 2(a).(a) is a partially enlarged front view of the gear as seen from the direction of arrow IIIa in Figure 1, and (b) is a partially enlarged plan view of the gear as seen from the direction of arrow IIIb in Figure 3(a).This is a schematic diagram showing part of the manufacturing method for chamfering tools.(a) is a front view of the chamfering tool used in the gear chamfering method of the second embodiment, and (b) is a bottom view of the chamfering tool as seen from the direction of arrow Vb in Figure 5(a).This is a schematic diagram showing a method for chamfering gears in the third embodiment.This is a schematic diagram showing a method for chamfering gears in the fourth embodiment.(a) is a front view of the chamfering tool used in the gear chamfering method of the fifth embodiment, (b) is a side view of the chamfering tool viewed from the direction of arrow VIIIb in Figure 8(a), and (c) is a bottom view of the chamfering tool viewed from the direction of arrow VIIIc in Figure 8(a). The following describes preferred embodiments with reference to the attached drawings. Figure 1 is a perspective view of the gear 10 and the chamfering tool 20 (hereinafter referred to as "tool 20") showing the chamfering method for the gear 10 in the first embodiment. Figure 2(a) is a front view of the tool 20. Figure 2(b) is a bottom view of the tool 20 as seen from the direction of arrow IIb in Figure 2(a). Note that the lower half of the gear 10 is omitted from the illustration in Figure 1. Also, the rear end (upper side) of the tool 20 is omitted from the illustration in Figures 1 and 2(a). As shown in Figure 1, the gear 10 is an external gear equipped with multiple teeth 12 (18 in this embodiment) that protrude radially outward from the outer surface of a cylindrical body centered on the rotation axis C1. The multiple teeth 12 are arranged at equal intervals around the rotation axis C1 and are identical in shape to each other. Furthermore, the multiple teeth 12 extend parallel to the rotation axis C1. On the outer circumferential surface of the cylindrical gear 10, the surfaces between multiple teeth 12 are the tooth root surfaces 13. Of each tooth 12, the radially leading surface is the tooth tip surface 12a, and the pair of surfaces connecting the tooth tip surface 12a and the tooth root surface 13, facing circumferentially, are the tooth surfaces 12b and 12c. Note that, if the right side of Figure 1 is considered the front of the gear 10 in the axial direction of the rotation axis C1 (arrow Y direction), then in that front view, tooth surface 12b oriented clockwise, and tooth surface 12c oriented counterclockwise. The intersection line between the axial end face 14 of the rotation axis C1 of gear 10 and the tooth tip surface 12a is the edge 15a. Also, the intersection line between the end face 14 and the tooth surface 12b is the edge 15b. The intersection line between the end face 14 and the tooth surface 12c is the edge 15c. The intersection line between the end face 14 and the tooth root surface 13 is the edge 15d. In this type of gear 10, multiple teeth 12 are formed by a gear cutting device and a rolling device (not shown). Subsequently, multiple edges 15b to 15d are chamfered by a tool 20. Finally, edge 15a is chamfered by another tool (not shown). As shown in Figures 2(a) and 2(b), the tool 20 comprises a cylindrical shank 21 centered on the tool axis C2, a body 22 provided at the axial end of the shank 21 (lower side in Figure 2(a)), and a cutting edge 23 extending radially from the body 22. The body 22 tapers as it moves axially away from the shank 21. The shank 21 is held by a machine tool, such as a multi-tasking machine, at its rear end (the upper side in Figure 2(a)), which is opposite the body 22 in the axial direction. The machine tool transmits a driving force to rotate the tool 20 around the tool axis C2. This rotation of the tool 20 chamfers the edges 15b to 15d of the gear 10 by the cutting edge 23. The rotation direction Rt of the tool 20 when chamfering with the cutting edge 23 is clockwise when viewed from the axial end side shown in Fi