JP2002144150A - Method and device for grinding gear utilizing ultrasonic wave - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for grinding a gear capable of finish-grinding a work hardened after a cutting process by utilizing ultrasonic vibration. SOLUTION: An abrasive grain layer 9a is formed on the teeth of a tool gear 9 so formed as to be meshed with a work W, and the tool gear 9 and the work W are drivingly rotated to mesh the gear and the work with each other and provide the ultrasonic vibration to the tool gear 9 so as to grind the tooth flank of the work W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for grinding tooth surfaces of spur gears and various other gears, and particularly to an ultrasonic gear grinding method which does not require shaving or the like before heat treatment and can greatly improve machining efficiency. And an apparatus.

[0002]

2. Description of the Related Art Conventionally, as a processing method of a cutting gear, a forming gear cutting method using a cutting tool and a generating gear cutting method using a hob cutting method have been known. All of these gear cutting methods are performed by machining using a cutting tool or a hob. After the gear cutting, heat treatment such as quenching is performed, and final finishing is performed by a finish grinding process.

[0003] In the production of high precision gears, tooth surface grinding by grinding is very important. For example, the tooth surface grinding may be performed by a rolling method using a screw-shaped tool, or a peripheral edge of a disk-shaped substrate. There is grinding with a grindstone in which abrasive grains are formed.

[0004]

However, in the conventional gear grinding method, since the grinding efficiency of a high-hardness work is extremely low, the finish grinding margin after quenching is reduced as much as possible. Grinding is performed to a close state, and after quenching, fine finish grinding is performed to correct quenching distortion. For this reason, the number of steps until the gear is completed increases, and the influence on the manufacturing yield and productivity cannot be ignored.

[0005] As described above, since the number of steps from the cutting to the finish grinding is large in the production of the cutting gear, there is a problem that the improvement in productivity is limited particularly in the case of mass-producing a high-precision gear.

Accordingly, an object of the present invention is to provide a gear grinding method and a gear capable of precision finishing grinding by grinding a material quenched after a cutting process by using ultrasonic vibration.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a gear grinding method using ultrasonic waves, wherein an abrasive layer is formed on teeth of a tool gear having a shape meshing with a work, and the tool gear and the work are respectively driven to rotate. And ultrasonic vibration is applied to the tool gear while meshing with each other to grind a tooth surface of the work.

According to the present invention, when the abrasive layer formed on the tool gear meshes with the teeth of the work, the ultrasonic vibration is applied to the tool gear. Tooth surface can be ground.

The work may be of high hardness after quenching, and the tooth surface can be efficiently ground by the abrasive grains by the amplitude and the acceleration by the ultrasonic vibration.

In the method of the present invention, the tooth surface of the work may be ground while the positions of the work and the tool gear in the axial direction are relatively changed.

[0011] In this case, even when there is no rolling / sliding contact between the pitch circle portion of the work and the tool gear, the abrasive grains can be ground by changing the relative position of the work and the tool gear in the axial direction.

A gear grinding apparatus using an ultrasonic wave according to the present invention comprises: a tool gear having an abrasive layer formed on teeth; an ultrasonic vibration device for applying ultrasonic vibration to the tool gear; A drive mechanism for transmitting rotation to the tool gear via a device, and a holding means for holding the work rotatably, the work being meshed with the tool gear so that the tooth surface thereof can be ground. Features.

According to the present invention, similarly to the grinding method, when the abrasive layer formed on the tool gear meshes with the teeth of the work, ultrasonic vibration is applied to the tool gear, so that the abrasive grains of the abrasive layer The tooth surface of the workpiece can be ground by a minute vibration.

In the gear grinding device according to the present invention, the tool gear and the work may be configured to be relatively movable in the respective axial directions.

[0015] Even in this case, the abrasive grains can be ground by changing the relative position of the workpiece and the tool gear in the axial direction even in a portion where there is no rolling sliding contact between the pitch circle of the workpiece and the tool gear.

In the present invention, the frequency of the ultrasonic vibration applied to the tool gear is about 20 kHz to 60 kHz, and more preferably 30 kHz to 40 kHz.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of a gear grinding apparatus using ultrasonic waves according to an embodiment of the present invention, FIG. 2 is a plan view, and FIG. 3 is a right side view.

In FIG. 1, a tool table 2 and a work table 3 are arranged on a base 1 having a platen shape so as to be horizontally movable in the direction of arrow A in FIG. The tool table 2 is slidably disposed on a pair of slide guides 1 a provided on the base 1, and has an operating shaft 4 a connected to an output shaft of the drive motor 4.
Can be transmitted to the tool table 2 by the screw gear mechanism. On the other hand, the work table 3 is also slidably disposed on a pair of slide guides 1b provided on the base 1,
The rotation of the output shaft of the drive motor 5 is transmitted by the screw gear mechanism, and the work table 3 is displaced in the direction of arrow B in FIG.

The tool table 2 is mounted with an ultrasonic vibration device 6 and a rotary drive motor 7 for driving the ultrasonic spindle 6a. The ultrasonic vibrator 6 is a conventionally known ultrasonic vibrator having a built-in ultrasonic vibrator (not shown), and ultrasonic vibration is transmitted to the ultrasonic spindle 6a in the radial direction and the axial direction by the ultrasonic vibrator. You. The ultrasonic spindle 6a is also connected to the output shaft of the rotary drive motor 7 by a coupling. Therefore, the ultrasonic spindle 6a rotates at a predetermined peripheral speed while being ultrasonically vibrated by the ultrasonic vibration device 6 and the rotation drive motor 7. The tip of the ultrasonic spindle 6a is rotatably supported by a bracket 2a provided on the tool table 2.

The work table 3 has a work drive motor 8
Is mounted, and a work W of a spur gear is detachably attached to the output shaft 8a. The workpiece W is a piece that has been subjected to a heat treatment of quenching after cutting by a hobbing machine, and has not been subjected to shaving or grinding for rough finishing. The slide guide 1b may have a linear shape, but may have a curved shape so as to be able to perform a rightward arc movement in FIG.

A tool gear 9 meshing with the workpiece W is attached to the ultrasonic spindle 6a. This tool gear 9
As shown in FIG. 4, an abrasive layer 9a having a uniform thickness is formed on the tooth bottom, tooth surface, and cutting edge surface. The tool gear 9 is formed of tool steel or high-speed steel, and the abrasive layer 9a is formed on the surface of the tool gear 9 by electrodeposition or metal bond using diamond abrasive grains or CBN as a raw material.

Here, the work W and the tool gear 9 on which the abrasive grain layer 9a is formed naturally have the same module. I do.

In the above configuration, the drive motor 4 is mounted on the workpiece W and the tool gear 9 in the positional relationship shown in FIGS.
Thereby, the tool table 2 is moved to the left, and the tool gear 9 is engaged with the work W. Next, the rotation drive motor 7
The tool gear 9 and the work W are driven to rotate by operating the work drive motor 8 and the ultrasonic vibration device 6 at the same time.
Activate Thereby, the tool gear 9 attached to the ultrasonic spindle 6a rotates while meshing with the workpiece W while ultrasonically vibrating in the axial direction and the radial direction.
The frequency of the ultrasonic spindle 6a during grinding is 2
It is 0 kHz to 40 kHz.

The engagement between the tool gear 9 and the workpiece W causes
The tooth surface of the work W is subjected to ultrasonic vibration of the abrasive layer 9a of the tool gear 9, and is subjected to pressure. That is, the workpiece W and the tool gear 9 are driven to rotate and rotate while meshing with each other, so that the tooth surface of the work W is ground by the relative movement of the abrasive layer 9a with respect to the tooth surface of the abrasive grains due to rolling and sliding contact. You. At this time, since the abrasive grains of the abrasive grain layer 9a vibrate ultrasonically, the amplitude of the abrasive grains causes the abrasive grains of the abrasive grain layer 9a to grind and grind a minute amount of meat from the tooth surface. Therefore, while engaging the tool gear 9 with the work W, the tooth surface of the work W can be ground from the shape shown by the two-dot chain line in FIG.

In such grinding, when the drive motor 5 is operated to rotate its output shaft forward and backward at a constant cycle, the work W reciprocates in the direction of the arrow in FIG.
In such a reciprocating operation of the work W, the tooth surface of the work W slides in contact with the tooth surface of the abrasive layer 9a of the tool gear 9 in the axial direction. Since ultrasonic vibration is also applied to the tool gear 9 in the axial direction, it is possible to grind the tooth surface of the work W with the abrasive grains of the abrasive grain layer 9a with a small amplitude while making sliding contact. Accordingly, it is possible to sufficiently grind the workpiece W and the pitch circle portion of the tool gear 9 having no rolling sliding contact, and it is possible to satisfactorily grind the entire tooth surface of the workpiece W.

FIG. 5 is an enlarged view showing the form of the abrasive layer 9a, and FIG. 6 is a model diagram showing the grinding of the tooth surface of the workpiece W by the abrasive layer 9a.

As shown in FIG. 6, the abrasive layer 9a is
b is configured to include a large number of abrasive grains 9c such as diamond. By applying ultrasonic vibration to the tool gear 9 having such abrasive grains 9c formed on the tooth surface,
As shown in FIG. 6, one abrasive grain 9c vibrates slightly left and right along the surface of the work W indicated by a two-dot chain line. Therefore,
The abrasive layer 9a moves while rolling and sliding on the surface of the work W, and the surface of the work W hatched in FIG. 6 is ground by micro-vibration caused by the application of ultrasonic vibration so that the profile shown by the solid line is obtained. can do.

As described above, in the present invention, the work W is ground while applying ultrasonic vibration to the tool gear 9 on which the abrasive layer 9a is formed, so that even if the work has a higher hardness than the conventional grinding method. Finish grinding can be performed without any trouble. Therefore, the workpiece W after the quenching treatment can be ground into a product without shaving the workpiece after the cutting or press molding or performing the rough finishing grinding step. For this reason,
Compared to the conventional manufacturing method, the number of processing steps is reduced, and the productivity is greatly improved.

In the illustrated example, the workpiece W is processed as a spur gear. However, bevel gears, hypoid gears, worms, and wheels thereof can be used as workpieces. The tooth surface can be ground by using the tool gear on which the layer is formed.

[0031]

According to the present invention, the tool gear on which the abrasive layer is formed is ground while engaging the tool gear while applying ultrasonic vibration to the tool gear. Becomes possible. Therefore, even in the case of a work in which a large finishing margin remains due to poor accuracy just by cutting or pressing, grinding can be efficiently performed after hardening is performed as it is and hardness is increased. As a result, grinding before quenching can be omitted, the number of steps can be reduced as compared with the conventional method, and significant improvement in productivity can be achieved.

Further, ultra-fine dimples formed by biting of the tip of the abrasive grains are continuously superimposed on the tooth surface of the gear finished by the apparatus of the present invention, so that a lubricating oil pool is formed.
The lubricity is improved and the wear on the tooth surface is reduced, so that not only the life is extended but also the transmission efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a front view of a gear grinding device using ultrasonic waves according to the present invention.

FIG. 2 is a plan view of the gear grinding device.

FIG. 3 is a right side view of the gear grinding device.

FIG. 4 is a front view of a main part showing a state where the work is engaged with the tool gear.

FIG. 5 is an enlarged view of a main part showing a form of an abrasive layer.

FIG. 6 is a model diagram for describing grinding of a work by abrasive grains of an abrasive layer.

[Explanation of symbols]

 Reference Signs List 1 base 1a, 1b slide guide 2 tool table 2a bracket 3 work table 4 drive motor 5 drive motor 6 ultrasonic vibration device 6a ultrasonic spindle 7 rotation drive motor 8 work drive motor 8a output shaft 9 tool gear 9a abrasive layer W work

Claims (5)

[Claims] An abrasive layer is formed on teeth of a tool gear having a shape that meshes with a work, and the tool gear and the work are rotationally driven to apply ultrasonic vibration to the tool gear while meshing with each other. A gear grinding method using ultrasonic waves, characterized by grinding a tooth surface of a work. 2. An abrasive layer is formed on the teeth of a tool gear having a shape that meshes with a quenched work, and the tool gear and the work are driven to rotate and mesh with each other while ultrasonic vibration is applied to the tool gear. And grinding the tooth surface of the work by using an ultrasonic wave. 3. The gear grinding using ultrasonic waves according to claim 1, wherein the tooth surface of the work is ground while the positions of the work and the tool gear in the axial direction are relatively changed. Method. 4. A tool gear having an abrasive layer formed on teeth, an ultrasonic vibration device for applying ultrasonic vibration to the tool gear, and a drive for transmitting rotation to the tool gear via the ultrasonic vibration device. A gear grinding apparatus using ultrasonic waves, comprising: a mechanism; and holding means for rotatably holding the work, wherein the tool gear is meshed with the work so that the tooth surface can be ground. 5. The gear grinding apparatus using ultrasonic waves according to claim 4, wherein said tool gear and said workpiece are configured to be relatively movable in respective axial directions.