JPH10337614A - Chamfering method for tip of toothed gear and tool for chamfering tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable efficient, good accuracy chamfer, using general devices in a method for chamfering the tip of each tooth in a toothed gear at an edge along the tooth trace of its tip. SOLUTION: A tool for chamfering the tip of a toothed gear employs a mating toothed gear engaging with a toothed gear 10 to be chamfered, a module, and a toothed gear 12 having the number of teeth, and a helix angle equal to those of the mating toothed gear and a pressure angle greater than that of the mating toothed gear, where, the tooth flank 16 of each tooth 14 is used as a grinding surface. The tool 12 for chamfering its tip is engaged with the toothed gear 10 and is rotated. Thus, the tip 20 of each tooth 18 in the toothed gear 10 is chamfered at a predetermined chamfering part 22, an edge along the tooth trace in its tip 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for chamfering the tip of each tooth of a gear at an edge of the tip along a tooth trace.

[0002]

2. Description of the Related Art FIGS. 6 and 7 show two conventional examples of the above-mentioned tooth tip chamfering technique. FIG. 6 shows an example of a ring gear 100 which is one of gears in a gear pair which is a hypoid gear or a bevel gear, and has an annular grindstone 101 extending along one circumference with a tapered cross section having a sharp tip.
Is pressed against a predetermined chamfered portion 106 which is an edge of a tooth tip 104 of each tooth 102 in the ring gear 100 and the grindstone 101 is rotated about one axis thereof. On the other hand, FIG. 7 shows an example of a pinion gear 110 which is a mating gear in the above-mentioned gear pair.
The conventional example in which the grinding stone 112 is moved along the planned chamfered portion 118 while being pressed against the planned chamfered portion 118 which is the edge of the tooth tip 116 of FIG.

[0003]

However, the prior art described above has a problem that a special device is required for positioning the grindstone with respect to the gear to be chamfered. However, there is a problem that a special device is required for positioning the grindstone with respect to the gear to be chamfered and moving the grindstone with respect to the gear.

[0004] Further, in any of the conventional examples, in order to chamfer all the teeth of a gear to be chamfered, the gear must be indexed to a grindstone, and it is difficult to improve the efficiency of chamfering. There was also a problem that it is.

Further, in any of the conventional examples, the relative position between the gear to be chamfered and the grindstone is determined without considering the variation in the shape error such as the outer diameter dimension error and the eccentric error of the gear. Also, there is a problem that it is difficult to increase the precision of the chamfering process.

[0006] The present invention has been made to solve these problems.

[0007]

According to the first aspect of the present invention, there is provided a method of chamfering the tip of each tooth of a gear at an edge of the tip along a tooth trace of the gear. A tooth tip chamfering tool which is a gear having the same module, number of teeth, and torsion angle as the mating gear but a pressure angle larger than that of the mating gear, each of which has a chamfered surface for chamfering the tip of the gear. And the tip chamfering tool is engaged with the gear and rotated, whereby
The gist is that the tooth tip of the gear is chamfered.

Here, the "pressure angle" generally means a tangent to the tooth profile at an arbitrary point on the tooth surface, a normal to a tangential plane to a cylinder passing through the point coaxial with the reference pitch cylinder for a cylindrical gear, and a bevel gear for a bevel gear. The normal of the tangent plane to the cone passing through that point, which is coaxial with the reference pitch cone, and the hypoid gear is used to transfer motion between staggered axes, or the cone passing through that point which is coaxial with the cone or a near-cone shape Or, it is defined as an acute angle between a normal to a tangent plane to a shape close to a cone and a normal to a plane passing through the point parallel to the datum plane in the rack.

[0009] The "helix angle" is generally defined as
It is defined as the acute angle formed by the gear that considers the tooth traces and a coaxial arbitrary virtual cylinder, cone, or generatrix having a shape close to the cone.

The "chamfering surface" is a burnishing surface (a surface to which abrasive grains are attached) by which the tooth tip chamfering tool grinds an edge of the gear tip along the tooth streak, or burnishing by burnishing. Plane.

In the method according to the first aspect of the present invention, since the tip chamfering tool has a larger pressure angle than the mating gear, if the tip chamfering tool is engaged with the gear to be chamfered, the tip tip chamfering tool is engaged. The chamfering tool contacts the tooth tip edge of the gear at the tooth surface of each tooth thereof. In addition, since the tooth tip chamfering tool has a chamfered surface for chamfering the tooth tip of the gear, the tooth tip chamfering tool engages with the gear and rotates the tooth tip of the gear. The chamfering is performed by the tooth tip chamfering tool, and the chamfering is continuously performed on a plurality of teeth of the gear.

Therefore, according to the first aspect of the present invention, it is possible to easily design the tooth tip chamfering tool by utilizing the dimensions of the mating gear, and to add the tooth tip chamfering tool, the tooth tip chamfering tool, and the gear. As long as there is a general device that engages and rotates, chamfering can be performed,
Therefore, there is an effect that it is not necessary to manufacture or purchase a special device for chamfering.

Further, according to the first aspect of the present invention, by chamfering all the teeth of the gear by meshing and rotating the tooth tip chamfering tool and the gear, the indexing of the gear to the tooth tip chamfering tool can be performed. Since it is performed continuously, the effect that the efficiency of chamfering can be easily improved can be obtained.

Further, according to the first aspect of the present invention, the relative position between each tooth of the tooth tip chamfering tool and each tooth of the gear changes according to the variation of the shape error of the gear, and therefore, the gear Since the chamfering is performed in consideration of the variation of the shape error, the effect that the chamfering process can be easily performed with high accuracy can be easily obtained.

Furthermore, according to the first aspect of the present invention, the chamfering of the gear can be performed as long as there is a mating gear, so that the chamfering can be performed regardless of the type of the gear. Is also obtained.

According to a second aspect of the present invention, in the method for chamfering the tooth tip of the gear according to the first aspect, the chamfered surface is formed by the tip edge chamfering tool along an edge of the tooth tip of the gear. The point is that the ground surface to be ground is used.

According to the second aspect of the present invention, an effect is obtained that the tooth tip of the gear is efficiently chamfered by grinding.

In one aspect of the gear tip chamfering device suitable for carrying out the invention of claim 1 or 2, there is provided a rotating device for meshing and rotating the tip chamfering tool and the gear and the tip chamfering tool. (A) a holding portion that rotatably holds the gear and the tooth tip chamfering tool in a meshing state, and (b) a motor that meshes and rotates the gear and the tooth tip chamfering tool held by the holding portion. And a rotating device having: As the rotating device, a device manufactured or sold as a tooth contact tester can be used.

In another aspect of the gear tip chamfering device, the rotating device further comprises: (c) determining a relative position between the axis of the gear held by the holding portion and the axis of the tip chamfering tool. It also has a relative position changing mechanism for changing. According to this aspect, it is possible to change the relative position between the axis of the gear and the axis of the tip chamfering tool. For example, the relative position is determined by the depth at which the teeth of the tip chamfering tool fit into the tooth grooves of the gear. If it is changed, only a part of each tooth surface in the tooth tip chamfering tool does not need to be continuously used for chamfering the gear, and almost the entire tooth face in the tooth tip chamfering tool becomes substantially chamfered for the gear. The effect that it becomes possible to use it is obtained.

According to a third aspect of the present invention, there is provided a tooth tip chamfering tool used for chamfering a tooth tip of each tooth of the gear at an edge along the tooth trace of the tooth by rotating by meshing with the gear. A gear having the same module, number of teeth, and torsion angle as the mating gear to be meshed with the gear, but having a larger pressure angle than the mating gear, and each tooth surface being a chamfered surface for chamfering the tooth tip of the gear. The gist is that

According to the third aspect of the present invention, a tooth tip chamfering tool necessary for implementing the first or second aspect of the present invention is obtained.

According to a fourth aspect of the present invention, in the tip chamfering tool of the third aspect, the chamfered surface is ground by the tip chamfering tool along an edge of the tooth tip of the gear. The point is that the surface is ground.

According to the fourth aspect of the invention, an effect is obtained that one embodiment of the third aspect of the invention can be obtained.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below in detail with reference to the drawings.

The first embodiment of the present invention is a method of chamfering a tooth tip of a ring gear of a ring gear and a pinion gear constituting a gear pair that is a hypoid gear or a bevel gear by grinding.

In the present embodiment, as shown in FIG. 1, the module m, the number of teeth z and the torsion angle β are the same as the pinion gear which is the mating gear of the ring gear 10, but the pressure angle α is larger than the pinion gear. It is used as a beveling tool 12. Abrasive grains such as CBN (cubic boron nitride) and diamond are scattered and adhered to the tooth face 16 of each tooth 14 of the tooth tip chamfering tool 12 by an adhesive. The surface is a grinding surface (an example of a chamfered surface). Since the pressure angle α of the tooth tip chamfering tool 12 is larger than the pressure angle α of the pinion gear, when the tooth tip chamfering tool 12 and the ring gear 10 are engaged with each other, as shown in FIG. The tooth surface 16 contacts a predetermined chamfered portion 22 which is an edge of the tip 20 of each tooth 18 of the ring gear 10 along a tooth trace of the tooth tip 20.

The tooth beveling tool 12 and the ring gear 1
0 is rotated in a meshing state by the rotating device 24. FIG. 2 shows the rotating device 24. The rotating device 24 includes (a) the ring gear 10 and the tooth tip chamfering tool 12.
(B) motors 26 and 27 for meshing and rotating the ring gear 10 and the tooth tip chamfering tool 12 held by the holding portion (not shown); ) A relative position changing mechanism 28 for changing the relative position between the axis of the ring gear 10 held by the holding portion and the axis of the tooth tip chamfering tool 12 is provided. It is not essential to manufacture or purchase the rotating device 24 exclusively for chamfering. For example, a well-known tooth contact tester may be used.

Next, the contents of the chamfering method will be described with time. First, the ring gear 10 and the tooth tip chamfering tool 12 are set in the rotating device 24 in a non-meshing state. Next, the ring gear 10 and the tooth tip chamfering tool 1
2 are brought closer to each other by the relative position changing mechanism 28, thereby being brought into an engaged state. In the meshing state, as shown in FIG. 1, there is a backlash between each tooth 18 of the ring gear 10 and each tooth 14 of the tooth tip chamfering tool 12.

Next, the ring gear 10 is chamfered. The chamfer is performed on a plurality of scheduled chamfers 1 of the ring gear 10.
In 6, the process is sequentially performed on one and the other of each pair of scheduled chamfers 16 (hereinafter, simply referred to as “each pair of chamfered portions 16”) facing each other across each tooth space.

More specifically, first, the motor 27 is rotated in the forward rotation direction as a drive motor, while the motor 26 is operated as a braking motor. Chamfering is performed on the front side (in this case, the forward rotation direction). While the ring gear 10 is rotating, one of the predetermined chamfers 16
Is continuously performed on the plurality of teeth 18 of the ring gear 10, and the chamfering on one of the predetermined chamfers 16 is completed by the predetermined number of rotations. The rotation speed of the tip chamfering tool 12 is determined according to the grinding ability of the ground surface.

Next, the motor 27 is rotated in the reverse rotation direction as a driving motor, while the motor 26 is operated as a braking motor, whereby the rotation direction of the ring gear 10 in the pair of chamfered portions 16 (in this case, Chamfering is performed on the front side in the rotation direction). During rotation of the ring gear 10, chamfering with respect to the other scheduled chamfered portion 16 is continuously performed on the plurality of teeth 18 of the ring gear 10, and chamfering with respect to the other scheduled chamfered portion 16 is completed by a predetermined number of rotations.

It should be noted that, in this embodiment,
The motor 27 functions as a drive motor and the motor 26 functions as a brake motor when the object to be chamfered is one of the paired chamfered portions 16 or the other. 27 is rotated in one rotation direction (forward rotation direction or reverse rotation direction) as a drive motor, and the motor 26 is operated as a braking motor, thereby chamfering one of the pairs of scheduled chamfers 26 to drive the motor 26. By rotating the motor 27 in one rotation direction (a rotation direction corresponding to the rotation direction of the motor 27), the other scheduled chamfer 16 can be chamfered by operating the motor 27 as a braking motor. Without changing the rotation direction of the motors 26 and 27, the motor 2
6 and 27 alternately act as drive motors or brake motors, respectively, so that each pair of
One and the other can be chamfered in order.

Further, in this embodiment, the chamfering of the ring gear 10 is performed in a state where the depth at which the teeth 14 of the tooth tip chamfering tool 12 fit into the tooth grooves of the ring gear 10 does not change. However, among the tooth surfaces 16 of the tooth tip chamfering tool 12, the ring gear 10
Each time the area in contact with the wear becomes unable to perform a normal grinding operation, for example, each time the chamfering of the set plurality of ring gears 10 is completed, the tooth 14
The relative position changing mechanism 28 changes the depth at which the ring gear 10 fits into the tooth groove of the ring gear 10, whereby the area of each tooth surface 16 of the tooth tip chamfering tool 12 that contacts the ring gear 10 can be updated. In this manner, substantially the entire tooth surface 16 of the tip chamfering tool 12 can be used for grinding the plurality of ring gears 10, and as a result, substantially the entire tooth surface 16 of the tip chamfering tool 12 is effectively used. It will be available for chamfering.

The second embodiment of the present invention is a method of chamfering the tooth tip of a pinion gear by grinding. This embodiment is common to the first embodiment except for points to be chamfered, and therefore will be briefly described.

In this embodiment, as shown in FIG. 3, the module m, the number of teeth z, and the torsion angle β are the same as those of the ring gear 10 which is the mating gear of the pinion gear 30, but the pressure angle α is larger than that of the ring gear 10. Are used as the tooth tip chamfering tool 32. The tooth surface 36 of each tooth 34 in the tooth tip chamfering tool 32 is a ground surface (an example of a chamfered surface) in the same manner as in the first embodiment. The pressure angle α of the tooth tip chamfering tool 32 is the ring gear 1
Since the pressure angle α is larger than 0, when the tooth tip chamfering tool 32 and the pinion gear 30 are engaged with each other,
As shown in FIG.
6 comes into contact with a predetermined chamfered portion 42 which is an edge along a tooth trace of a tooth tip 40 of each tooth 38 of the pinion gear 30. The tooth tip chamfering tool 32 and the pinion gear 30 are connected to the rotating device 24 as in the first embodiment.
Is rotated in a meshing state.

In any of the embodiments, the tip chamfering tools 12 and 32 can be manufactured by another method. Can also be produced by bonding abrasive grains with a binder.

The third embodiment of the present invention relates to a ring gear 10
Is chamfered by burnishing.
The present embodiment is common to the first embodiment except for the types of chamfering processing, and therefore will be briefly described.

FIG. 4 shows a tooth tip chamfering tool 60 for chamfering. This tooth tip chamfering tool 60
It has the same shape as the tooth tip chamfering tool 12, but each tooth surface 64 of each tooth 62 is a burnishing surface (an example of a chamfered surface). The surface hardness of each tooth surface 64 is higher than that of the ring gear 10 to be chamfered by quenching or the like.

In this tip beveling method, if the ring gear 10 and the tip beveling tool 60 are engaged and rotated, the respective tooth faces 64 of the tip beveling tool 60 become ring gear 1.
The zero tooth tip 20 contacts locally at its intended chamfer 22. As a result, the tooth tip 20 is
Is subjected to burnishing locally, and as a result, the tooth tip 20 of the ring gear 10 is chamfered.

In the fourth embodiment of the present invention, the pinion gear 3
This is a method of chamfering the 0 tooth tip 40 by burnishing. This embodiment is common to the second embodiment except for the types of chamfering processing, and will be described briefly.

FIG. 5 shows a tip chamfering tool 70 for chamfering. This tooth tip chamfering tool 70
It has the same shape as the tooth tip chamfering tool 32, but each tooth surface 74 of each tooth 72 is a burnishing surface (an example of a chamfered surface). The surface hardness of each tooth surface 74 is higher than that of the pinion gear 30 to be chamfered by quenching or the like.

In this tooth tip chamfering method, if the pinion gear 30 and the tooth tip chamfering tool 70 are engaged and rotated, the respective tooth faces 74 of the tooth tip chamfering tool 70 are attached to the tooth tip 40 of the pinion gear 30 at the predetermined chamfered portion. At 42, a local contact is made. Thus, the tooth tip 40 is locally burnished at the predetermined chamfered portion 42, and as a result, the tooth tip 40 of the pinion gear 30 is chamfered.

Although some embodiments of the present invention have been described in detail with reference to the drawings, various modifications may be made based on the knowledge of those skilled in the art without departing from the scope of the claims. The present invention can be implemented in an improved form.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which a method of chamfering a tooth tip of a gear according to an embodiment of the present invention is performed.

FIG. 2 is a plan view conceptually showing a configuration of a rotating device used when performing the above-described tooth tip chamfering method.

FIG. 3 is a perspective view illustrating a state in which a tooth tip chamfering method according to another embodiment of the present invention is performed.

FIG. 4 is a perspective view showing a state in which a tooth tip chamfering method according to still another embodiment of the present invention is performed.

FIG. 5 is a perspective view showing a state where a tooth tip chamfering method of a gear according to still another embodiment of the present invention is performed.

FIG. 6 is a perspective view showing a state in which a conventional example of a method of chamfering a tooth tip of a gear is performed.

FIG. 7 is a perspective view showing a state in which another conventional example of a method of chamfering a tooth tip of a gear is performed.

[Explanation of symbols]

 Reference Signs List 10 ring gear 12, 32, 60, 70 tooth tip chamfering tool 16, 36 grinding surface 20, 40 tooth tip 22, 42 scheduled chamfer 24 rotating device 30 pinion gear 64, 74 burnishing surface

Claims (4)

[Claims] 1. A method of chamfering a tooth tip of each tooth of a gear at an edge along a tooth trace of the tooth tip, wherein a counterpart gear to be meshed with the gear has the same module, number of teeth and torsion angle. A gear whose pressure angle is larger than that of the mating gear, and each tooth surface of which is a chamfered surface for chamfering the tooth tip of the gear is set as a tooth tip chamfering tool, and the tooth tip chamfering tool is engaged with the gear and rotated. A method for chamfering the tooth tip of the gear. 2. The tip chamfering of a gear according to claim 1, wherein the chamfering surface is a grinding surface on which the tip chamfering tool grinds an edge of a tooth tip of the gear along a tooth streak. Method. 3. A tooth tip chamfering tool used for beveling a tooth tip of each tooth of the gear by being engaged with the gear and rotating the edge of the tooth tip along an edge of the tooth tip. The gear, the number of teeth and the helix angle are the same as the mating gear to be engaged, but the pressure angle is larger than the mating gear, and each tooth surface is a chamfered surface for chamfering the tooth tip of the gear. Tip chamfering tool. 4. The tooth tip chamfering tool according to claim 3, wherein the chamfering surface is a grinding surface for grinding the edge of the tooth tip of the gear along the tooth streak.