JP2021171839A - Gear grinding device and gear grinding tool - Google Patents

Abstract

To provide a gear grinding device and a gear grinding tool with good productivity capable of efficiently creating a high-accuracy gear.SOLUTION: A gear grinding device includes: a work shaft 6 for rotatably supporting a workpiece W; a grinding tool 10 for grinding-processing a tooth surface on the workpiece W by moving an edge 11 in a tooth trace direction while rotating; an ultrasonic vibrator 3 for oscillating supersonic vibration in the rotation axis direction of the grinding tool 10 in response to a signal from an ultrasonic wave oscillator 2; and a booster 4 for amplifying the ultrasonic vibration by connecting the ultrasonic vibrator 3 and the grinding tool 10. The edge 11 ultrasonically vibrates in a tooth shape direction relative to the tooth surface. A small diameter part having a smaller diameter than opposite end sides or a large diameter part having a larger diameter than the opposite end sides is formed in a center in the rotation axis direction on a base metal 12 of the grinding tool 10. Thus, high-accuracy tooth surface grinding with less grinding stripes becomes possible.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gear grinding device and a gear grinding tool for creating a gear, and more particularly to a gear grinding device and a gear grinding tool capable of machining a tooth surface with high accuracy by utilizing ultrasonic vibration.

Conventionally, a gear grinding device including an ultrasonic wave generator is known. In this type of gear grinding device, the ultrasonic vibration oscillated from the ultrasonic generator is transmitted to the gear grinding tool, and the tooth surface of the gear is ground by the gear grinding tool that vibrates ultrasonically.

For example, Patent Document 1 discloses a cradle type bevel gear creation device having an ultrasonic wave generator that applies ultrasonic vibration to a cutting tool shaft. The cradle type bevel gear creation device disclosed in the same document tilts the work shaft with respect to the cradle shaft, swings a trapezoidal conical work fixed to the work shaft, and applies ultrasonic vibration to a rotating cutting tool. In addition, the cutting tool is used to create a tooth profile on the outer peripheral surface of the workpiece.

Further, for example, in Patent Document 2, the tooth surface is ground by applying ultrasonic vibration to the tool gear while engaging the tool gear having a shape that meshes with the work with respect to the gear that has been gear-cut by the cutting process. The gear grinding device to be used is disclosed.

Japanese Unexamined Patent Publication No. 2011-31317 JP-A-2002-144150

In recent years, the use of gears has been increasing in various robots, electronic devices, and other precision machines that perform precision movements. Gears are required. Therefore, in the manufacture of gears, an advanced processing technique capable of efficiently finishing the tooth surface with high accuracy is required.

However, in the above-mentioned conventional gear grinding apparatus, it is easy to further reduce the grinding streaks formed on the tooth surface by grinding to further improve the precision of the tooth surface and to process a highly accurate gear with high efficiency. There was a problem that it was not.

Specifically, it is necessary to bring the ultrasonic vibration of the cutting edge of the grinding tool that comes into contact with the tooth surface to process the tooth surface into a state suitable for grinding. Even if ultrasonic vibration is applied to the grinding tool from the ultrasonic generator, if the cutting edge of the grinding tool that grinds the tooth surface does not have ultrasonic vibration suitable for grinding, it is possible to finish the tooth surface with high accuracy. Can not.

Further, for example, the conventional technique disclosed in Patent Document 2 is to honing a geared work with a tool gear that meshes with the work, and efficiently performs gear grinding using ultrasonic vibration. It's not something you can do.

In addition, in order to cope with higher precision of tooth surface machining, there is a problem that the productivity of gears is lowered due to the high functionality of the gear grinding machine and the complicated machining process, and it is difficult to reduce the production cost. There is also.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a highly productive gear grinding device and a gear grinding tool capable of efficiently creating high-precision gears. There is.

The gear grinding device of the present invention includes a work shaft that rotatably supports a work, a grinding tool in which the cutting edge moves in the direction of tooth streaks while rotating to grind the tooth surface on the work, and an output from an ultrasonic oscillator. It has an ultrasonic vibrator that generates ultrasonic vibration in the rotation axis direction of the grinding tool, and a booster that connects the ultrasonic vibrator and the grinding tool to amplify the ultrasonic vibration. The cutting edge is characterized by ultrasonically vibrating in the tooth profile direction with respect to the tooth surface.

Further, the gear grinding tool of the present invention is a gear grinding tool used in a gear grinding device having an ultrasonic vibrator, and one end face is fixed to a booster connected to the ultrasonic vibrator and rotates. It has a gold and a cutting edge provided on the base metal to move the work surface of the work in the tooth streak direction to grind the tooth surface on the work, and the cutting edge is oscillated from the ultrasonic vibrator. The ultrasonic vibration amplified by the booster causes ultrasonic vibration in the tooth profile with respect to the tooth surface, and the base metal has a small diameter portion having a diameter smaller than that of both ends or both ends in the center of the rotation axis direction. It is characterized in that a large-diameter portion having a larger diameter is formed.

According to the gear grinding device of the present invention, a work shaft that rotatably supports a work, a grinding tool in which the cutting edge moves in the direction of tooth streaks while rotating to grind the tooth surface on the work, and an ultrasonic oscillator are used. It has an ultrasonic vibrator that generates ultrasonic vibration in the direction of the rotation axis of the grinding tool by a signal, and a booster that connects the ultrasonic vibrator and the grinding tool to amplify the ultrasonic vibration, and the cutting edge has teeth. It vibrates ultrasonically in the tooth profile direction with respect to the surface.

With such a configuration, highly accurate tooth surface grinding with few grinding streaks becomes possible. In addition, an oil pocket can be formed on the tooth surface by grinding with a suitable ultrasonic vibration. Therefore, a gear having an excellent tooth surface property, which has a small coefficient of friction on the tooth surface, less noise and vibration, high strength, and high familiarity and lubricity, can be obtained.

Further, since the cutting edge moves in the tooth trace direction and ultrasonically vibrates in the tooth profile direction with a suitable strength, highly efficient gear grinding can be performed at a low peripheral speed. In addition, high-precision gear machining is possible even if a small-diameter grinding tool is used. As a result, the productivity of the gear grinding device and the gear can be improved, and the production cost can be reduced.

Further, according to the gear grinding device of the present invention, the base metal of the grinding tool has a small diameter portion having a diameter smaller than that of both end sides or a large diameter portion having a diameter larger than that of both end sides in the center of the rotation axis direction. May be formed. With such a configuration, ultrasonic vibration suitable for the cutting edge for grinding the tooth surface can be transmitted, and highly accurate and highly efficient gear grinding becomes possible.

Further, according to the gear grinding device of the present invention, the base metal of the grinding tool is formed with a small diameter portion having a diameter smaller than that of both ends at the center in the direction of the rotation axis, and the base metal is the base metal. One end face in the rotation axis direction is fixed to the booster, the cutting edge is formed on the other end face, and the work may be created in a bevel gear. As a result, a highly accurate bevel gear with excellent tooth surface properties can be processed with high efficiency.

Further, according to the gear grinding apparatus of the present invention, the small diameter portion may be formed in a hyperboloidal shape. With such a base metal shape, ultrasonic vibration can be efficiently transmitted to the cutting edge in a suitable state, high-precision and high-efficiency grinding is performed, and a gear having excellent tooth surface properties can be obtained.

Further, according to the gear grinding device of the present invention, the base metal of the grinding tool is formed with a large diameter portion having a diameter larger than that of both ends at the center in the direction of the rotation axis. One end face in the rotation axis direction is fixed to the booster, the other end face is fixed to the second booster that amplifies the ultrasonic vibration, and the cutting edge is screw-shaped on the outer periphery of the large diameter portion. The work is created in a parallel shaft gear. As a result, it is possible to create a parallel shaft gear with high accuracy, low noise and low vibration.

Further, according to the gear grinding apparatus of the present invention, a cavity may be formed in the center of rotation of the base metal. As a result, the ultrasonic vibration of the cutting edge can be made suitable for grinding, and the machining accuracy and machining efficiency can be improved.

Further, according to the gear grinding tool of the present invention, one end face is fixed to a booster connected to the ultrasonic vibrator and rotates, and a base metal provided on the base metal and the work surface of the work is in the tooth streak direction. The workpiece has a cutting edge that moves to and grinds the tooth surface, and the cutting edge ultrasonically vibrates in the tooth profile direction of the tooth surface by the ultrasonic vibration amplified by the booster, and the base metal is in the direction of the rotation axis. A small-diameter portion having a smaller diameter than both ends or a large-diameter portion having a larger diameter is formed in the center. As a result, the ultrasonic vibration from the booster can be transmitted to the cutting edge in a state suitable for grinding, and the cutting edge can be ultrasonically vibrated. Therefore, a high-precision gear can be efficiently created.

It is a figure which shows the schematic structure of the vicinity of the grinding tool of the gear grinding apparatus which concerns on embodiment of this invention. It is a figure which shows the grinding tool of the gear grinding apparatus which concerns on embodiment of this invention. It is a figure which shows the grinding direction of the tooth surface by the cutting edge of the grinding tool of the gear grinding apparatus which concerns on embodiment of this invention. It is a figure which shows the schematic structure of the vicinity of the grinding tool of the gear grinding apparatus which concerns on other embodiment of this invention. It is a figure of the grinding tool of the gear grinding apparatus which concerns on other embodiment of this invention.

Hereinafter, the gear grinding apparatus according to the embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration in the vicinity of the grinding tool 10 of the gear grinding apparatus 1 according to the embodiment of the present invention.

The gear grinding device 1 is, for example, a cradle-type or electrically controlled manufacturing device that grinds curved tooth bevel gears, hypoid gears, and the like. As shown in FIG. 1, the gear grinding device 1 includes a work shaft 6 that rotatably supports the work W, a grinding tool 10 as a gear grinding tool for grinding the work W, an ultrasonic oscillator 2, and ultrasonic vibration. It has a child 3 and a booster 4.

The work shaft 6 supports the work W to be machined created in the gear. The work shaft 6 is connected to a drive motor (not shown) to rotatably support the work W, and the rotation shaft is configured to be tiltable and repositionable with respect to the rotation shaft of the grinding tool 10. Is also good.

The grinding tool 10 is supported by a column (not shown) having a feed mechanism (not shown) and a drive motor, and creates a gear of the work W while rotating. Specifically, the grinding tool 10 has a base metal 12 having a substantially columnar shape that rotates about its central axis, and the base metal 12 has a tooth streak direction X of the work W (see FIG. 3). A cutting edge 11 is formed which comes into contact with the work W and grinds the tooth surface W1 (see FIG. 3) while moving to.

The ultrasonic oscillator 2 is a device that supplies a signal and power for oscillating ultrasonic vibrations to the ultrasonic vibrator 3. The ultrasonic oscillator 2 is connected to a control device (not shown) of the gear grinding device 1, and sends an ultrasonic vibration signal required for grinding the work W to the ultrasonic transducer 3 based on a signal from the control device. ..

The ultrasonic vibrator 3 is a device that generates ultrasonic vibration necessary for grinding the work W based on a signal from the ultrasonic oscillator 2. Specifically, the ultrasonic vibrator 3 converts the electric power from the ultrasonic oscillator 2 into ultrasonic vibration in the rotation axis direction of the grinding tool 10 and transmits it to the booster 4.

The booster 4 is a device that amplifies ultrasonic vibration. The booster 4 connects the ultrasonic vibrator 3 and the grinding tool 10. That is, in the booster 4, one end 4a is connected to the ultrasonic vibrator 3, and the other end 4b is connected to the grinding tool 10. The ultrasonic vibration generated from the ultrasonic vibrator 3 is amplified by the booster 4 and transmitted to the grinding tool 10.

FIG. 2 is a diagram showing a grinding tool 10 of the gear grinding device 1.
With reference to FIGS. 1 and 2, in the base metal 12, the end face of one end portion 15 is fixed to the booster 4 connected to the ultrasonic vibrator 3, and the base metal 12 is attached to the end face of the other end portion 16. Is formed with a cutting edge 11 for grinding the work W by moving the work surface of the work W in the tooth streak direction X.

The cutting edge 11 is a grinding wheel having a substantially annular shape protruding from the end surface of the end portion 16 of the base metal 12, and is an electrodeposition wheel having abrasive grains of, for example, cBN, diamond, WC, GC, etc. It may be formed from a bond, a metal bond, a resin bond, or the like.

As described above, the ultrasonic vibration generated from the ultrasonic vibrator 3 is amplified via the booster 4 and transmitted to the grinding tool 10. As a result, the cutting edge 11 ultrasonically vibrates in the tooth profile direction Y (see FIG. 3) with respect to the tooth surface W1 (see FIG. 3).

FIG. 3 is a diagram showing the grinding direction of the tooth surface W1 by the cutting edge 11 of the grinding tool 10.
As shown in FIG. 3, the cutting edge 11 (see FIG. 2) moves the tooth surface W1 which is the work surface of the work W in the tooth streak direction X, and the ultrasonic wave amplified by the booster 4 (see FIG. 1). The tooth surface W1 is ground while ultrasonically vibrating with respect to the tooth surface W1 in the tooth profile direction Y.

That is, the cutting edge 11 of the rotating grinding tool 10 (see FIG. 2) ultrasonically vibrates in the tooth profile direction Y while moving the tooth surface W1 of the work W in the tooth streak direction X. In other words, the cutting edge 11 of the grinding tool 10 grinds the tooth surface W1 while vibrating in the tooth profile direction Y and moving in the tooth trace direction X in a substantially wavy line. The amplitude of the ultrasonic vibration of the cutting edge 11 is, for example, 2 to 50 μm, and the frequency is 15 to 50 kHz.

In this way, the cutting edge 11 of the rotating grinding tool 10 moves the tooth surface W1 in the tooth streak direction X and ultrasonically vibrates in the tooth profile direction Y, so that a deep grinding streak extending in the tooth streak direction X is formed. It becomes difficult to form. That is, due to the ultrasonic vibration in the tooth profile direction Y, no deep grinding streaks remain, and a shallow, highly accurate tooth surface W1 of the grinding streaks is formed.

With reference to FIG. 2, a small diameter portion 13 having a diameter smaller than that of both end sides, that is, both end portions 15 and 16 sides is formed at substantially the center of the base metal 12 in the rotation axis direction. As a result, the ultrasonic vibration of the cutting edge 11 becomes a state suitable for tooth surface grinding. Therefore, high-precision tooth surface grinding with few grinding lines is possible.

Specifically, the small diameter portion 13 is formed in a substantially hyperboloidal shape or a substantially arcuate surface shape. The base metal 12 having such a shape is particularly excellent in giving suitable ultrasonic vibration to the cutting edge 11. More specifically, when ultrasonic vibration is used, the vibration becomes smaller as the diameter of the cutting edge 11 becomes larger. However, by forming a substantially hyperboloidal or substantially arcuate small diameter portion 13 on the base metal 12 to optimize the shape, accurate vibration in the tooth profile direction can be obtained even if the diameter of the cutting edge 11 is large. be able to.

With reference to FIGS. 1 to 3, the ultrasonic vibration from the ultrasonic vibrator 3 is caused by the formation of the small diameter portion 13 having a substantially hyperboloidal shape or a substantially arcuate surface shape in the substantially center of the base metal 12. It is transmitted to one end 15 of the base metal 12 via the booster 4, and the vicinity of the one end 15 vibrates in the rotation axis direction.

At the substantially center of the base metal 12, that is, at the substantially center of the small diameter portion 13 having a substantially hyperboloidal shape or a substantially arcuate surface shape, the amplitude in the radial direction due to the Poisson's ratio is suppressed, so that vibration transmission in the rotation axis direction is improved. Will be done. Specifically, the substantially center of the small diameter portion 13 having a substantially hyperboloid shape is a vibration node having a vibration amplitude of about 0 in the direction of the rotation axis.

Then, the vicinity of the cutting edge 11, that is, the vicinity of the other end portion 16 of the base metal 12, is greatly ultrasonically vibrated in the direction opposite to the end portion 15 in synchronization with the vibration of the one end portion 15 along the rotation axis direction. The base metal 12 as a whole expands and contracts in the direction of the rotation axis. Since the small diameter portion 13 having a substantially hyperboloidal shape is formed as described above, the ultrasonic vibration from the ultrasonic vibrator 3 is efficiently transmitted to the cutting edge 11.

As described above, since the small diameter portion 13 is formed substantially in the center of the base metal 12, the ultrasonic vibration can be efficiently transmitted to the cutting edge 11 in a suitable state. As a result, high-precision and high-efficiency grinding is performed, and a gear having excellent tooth surface properties can be obtained.

Further, the oil pocket can be formed on the tooth surface W1 of the work W by the grinding process in which the cutting edge 11 is subjected to the ultrasonic vibration suitable for the cutting edge 11 as described above. The oil pocket is a fine unevenness on the gear surface, in other words, a depression.

By forming an oil pocket on the processed tooth surface W1, the friction coefficient of the tooth surface W1 is reduced, there is less noise and vibration, high strength, high familiarity and lubricity, and excellent tooth surface properties. A gear is obtained.

Further, since the cutting edge 11 moves in the tooth trace direction X and ultrasonically vibrates with a strength suitable for the tooth profile direction Y, highly efficient gear grinding can be performed at a low peripheral speed.

With such a low peripheral speed and low speed rotation, it is possible to perform a grinding process for forming a precise tooth surface W1 with high efficiency. That is, conventionally, 30,000 r. p. m. Grinding, which required high-speed rotation exceeding the above, can be performed with high accuracy at low-speed rotation.

Further, since gear grinding at a low peripheral speed is possible, high-precision gear machining can be performed even if a small-diameter grinding tool 10 is used. For example, the cutting edge 11 of the grinding tool 10 may have a rotation diameter of φ50 mm or less. By adding suitable ultrasonic vibration, it is not necessary to increase the peripheral speed of the grindstone of the cutting edge 11, and even if the cutting edge 11 is φ50 mm or less, low rotation and highly accurate tooth surface grinding is possible.

As described above, the gear grinding device 1 eliminates the need for a large and complicated grinding device that rotates the grinding tool 10 at high speed. Therefore, the productivity of the gear manufacturing apparatus and the gear can be improved, and the production cost can be reduced.

Next, with reference to FIGS. 4 and 5, the gear grinding apparatus 101 will be described in detail as an example of modifying the embodiment. The components having the same or similar actions and effects as those of the above-described embodiments are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 4 is a diagram showing a schematic configuration in the vicinity of the grinding tool 110 of the gear grinding apparatus 101 according to another embodiment of the present invention.

With reference to FIG. 4, the gear grinding apparatus 101 is an apparatus for grinding parallel shaft gears such as spur gears and helical gears. The gear grinding device 101 includes a work shaft 6 that rotatably supports the work W, a grinding tool 110 as a gear grinding tool for grinding the work W, an ultrasonic oscillator 2, an ultrasonic vibrator 3, and a booster 4. , And a booster 5 as a second booster.

The work shaft 6 supports the work W to be machined created in the gear. The work shaft 6 is connected to a drive motor (not shown) and rotatably supports the work W. The work shaft 6 may be configured to be tiltable and repositionable with respect to the rotation shaft of the grinding tool 110.

The grinding tool 110 is supported by a column (not shown) having a feed mechanism (not shown), a drive motor, or the like, and creates a gear from the work W while rotating. Specifically, the grinding tool 110 has a base metal 112 having a substantially columnar shape that rotates about its central axis. The base metal 112 is formed with a cutting edge 111 that grinds the tooth surface W1 (see FIG. 3) in contact with the work W while moving in the tooth streak direction X (see FIG. 3) of the work W.

In the base metal 112, one end face in the rotation axis direction, that is, the end portion 115, is fixed to the booster 4, and the other end face, that is, the end portion 116, becomes a booster 5 as a second booster that amplifies ultrasonic vibration. It is fixed. The booster 5 is rotatably supported by a column (not shown). That is, the base metal 112 has both ends 115 and 116 rotatably supported via boosters 4 and 5.

The grinding tool 110 may be provided so that its rotation axis extends substantially vertically, that is, in the vertical direction. Further, when the work shaft 6 is in a twisted position with respect to the rotation shaft of the grinding tool 110 and the rotation shaft of the grinding tool 110 is configured to be substantially vertical, the work shaft 6 extends substantially horizontally. It may be provided as follows.

FIG. 5 is a diagram showing a grinding tool 110 of the gear grinding device 101.
With reference to FIG. 5, the base metal 112 of the machining tool is formed with a large diameter portion 14 having a diameter larger than that of both end portions 115 and 116 sides at substantially the center in the rotation axis direction. The large diameter portion 14 has a substantially columnar shape. That is, the base metal 112 of the grinding tool 110 has a stepped substantially columnar shape in which a large diameter portion 14 is formed substantially in the center.

With reference to FIGS. 3 and 5, a cutting edge 111 that comes into contact with the work W and grinds the tooth surface W1 is formed on the outer periphery of the large diameter portion 14. The cutting edge 111 is formed in a substantially screw shape, and is, for example, an electrodeposition wheel having abrasive grains such as cBN, diamond, WC, and GC, a vitrified bond, a metal bond, a resin bond, and the like. You may. The cutting edge 111 moves relative to the tooth surface W1 of the work W in the tooth streak direction X while rotating. As a result, the work W is created as a parallel shaft gear with high accuracy, low noise and low vibration.

Further, referring to FIG. 5, a cavity 17 is formed in the base metal 112 at the center of rotation. The cavity 17 is a hollow portion having a substantially circular cross section and extending in the direction of the rotation axis. That is, the base metal 112 has a hollow shape and is formed in a substantially circular tubular shape. Since the cavity 17 is formed in the center of rotation of the base metal 112, the ultrasonic vibration of the cutting edge 111 is a vibration in the radial direction of the base metal 112 and is in a state suitable for grinding.

For details, with reference to FIGS. 4 and 5, the ultrasonic vibration in the rotation axis direction generated from the ultrasonic vibrator 3 is amplified by the booster 4 and transmitted to the end 115 of the base 112 of the grinding tool 110. Will be done. A booster 5 as a second booster is connected to the other end 116 of the base 112, and the booster 5 amplifies the vibration on the end 116 side. One end 115 and the other end 116 ultrasonically vibrate in opposite directions of the rotation axis in synchronization with each other. That is, the base metal 112 expands and contracts in the direction of the rotation axis.

Then, the large-diameter portion 14 substantially at the center of the base metal 112 repeatedly expands and contracts appropriately in the radial direction by ultrasonic vibration, and the cutting edge 111 formed in the large-diameter portion 14 ultrasonically vibrates in the radial direction. .. That is, the cutting edge 111 ultrasonically vibrates in the tooth profile direction Y (see FIG. 3) of the tooth surface W1 of the work W while moving in the tooth streak direction X of the tooth surface W1 of the work W due to the rotation of the grinding tool 110.

In other words, the cutting edge 111 of the grinding tool 110 moves in the tooth trace direction X in a substantially wavy line while swinging in the tooth profile direction Y, and grinds the tooth surface W1. As a result, the work W is formed with a highly accurate tooth surface W1 in which the grinding streaks are canceled and the teeth are shallow.

As described above, since the central portion of the base metal 112 is formed in a gap shape, the vibrations of both end portions 115 and 116 of the base metal 112 in the rotation axis direction are transmitted to substantially the center of the base metal 112 and are transmitted to the cutting edge 111. Generates radial vibration suitable for workpiece W grinding. As a result, high-precision grinding can be performed with high efficiency, and a gear with high precision and excellent tooth surface roughness can be obtained.

With the above-described configuration having the booster 4 and the booster 5, it is possible to generate radial vibration in the cutting edge 111. However, as the diameter of the cutting edge 111 becomes smaller, the vibration becomes smaller, and it becomes difficult to obtain a suitable vibration, that is, a large vibration. In the present embodiment, since the cavity 17 is formed in the rotation center of the base metal 112, the vibration can be optimized according to the diameter of the cutting edge 111. That is, the same vibration can be obtained regardless of the diameter of the cutting edge 111.

Further, the oil pocket can be formed on the tooth surface W1 of the work W by the grinding process in which the cutting edge 111 is subjected to the ultrasonic vibration suitable for the cutting edge 111 as described above. As a result, a gear having an excellent tooth surface property, which has a small friction coefficient of the tooth surface W1, less noise and vibration, high strength, and high familiarity and lubricity, can be obtained.

Further, since the cutting edge 111 moves in the tooth trace direction X and ultrasonically vibrates with a strength suitable for the tooth profile direction Y, highly efficient gear grinding can be performed at a low peripheral speed.

With such a low peripheral speed and low speed rotation, it is possible to perform grinding like a conventional general wheel. That is, conventionally, 30,000 r. p. m. Grinding, which required high-speed rotation exceeding the above, can be performed with high accuracy at low-speed rotation.

Further, since gear grinding at a low peripheral speed is possible, high-precision gear machining can be performed even if a grinding tool 110 having a small diameter is used. For example, the cutting edge 111 of the grinding tool 110 may have a rotation diameter of φ50 mm or less. By adding suitable ultrasonic vibration, it is not necessary to increase the peripheral speed of the cutting edge 111, and even if the cutting edge 111 is φ50 mm or less, low rotation and high precision gear grinding is possible.

As described above, the gear grinding device 101 eliminates the need for a large and complicated grinding device that rotates the grinding tool 110 at high speed. Therefore, the productivity of the gear manufacturing apparatus and the gear can be improved, and the production cost can be reduced.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.

1,101 Gear grinding device 2 Ultrasonic oscillator 3 Ultrasonic oscillator 4 Booster 4a End 4b End 5 Booster 6 Work shaft 10, 110 Grinding tool 11, 111 Cutting edge 12, 112 Base metal 13 Small diameter 14 Large diameter 15 , 115 End 16, 116 End 17 Cavity W Work W1 Tooth surface X Tooth streak direction Y Tooth profile direction

Claims (7)

A work shaft that rotatably supports the work and
A grinding tool that grinds the tooth surface on the work by moving the cutting edge in the direction of the tooth streaks while rotating.
An ultrasonic vibrator that generates ultrasonic vibration in the direction of the rotation axis of the grinding tool by the output from the ultrasonic oscillator,
It has a booster that connects the ultrasonic vibrator and the grinding tool and amplifies the ultrasonic vibration.
The cutting edge is a gear grinding device characterized by ultrasonically vibrating in the tooth profile direction with respect to the tooth surface. The base metal of the grinding tool is characterized in that a small diameter portion having a diameter smaller than that of both end sides or a large diameter portion having a diameter larger than that of both end sides is formed at the center in the direction of the rotation axis. The gear grinding device according to 1. The base metal of the grinding tool has a small diameter portion formed at the center in the direction of the rotation axis, which is smaller in diameter than both ends.
In the base metal, one end face in the direction of the rotation axis is fixed to the booster, and the cutting edge is formed on the other end face.
The gear grinding apparatus according to claim 1, wherein the work is created as a bevel gear. The gear grinding apparatus according to claim 2 or 3, wherein the small diameter portion is formed in a hyperboloidal shape. The base metal of the grinding tool is formed with a large diameter portion having a diameter larger than that of both ends at the center in the direction of the rotation axis.
One end face in the direction of the rotation axis of the base metal is fixed to the booster, and the other end face is fixed to the second booster that amplifies the ultrasonic vibration.
The cutting edge is formed in a screw shape on the outer circumference of the large diameter portion.
The gear grinding apparatus according to claim 1, wherein the work is created as a parallel shaft gear. The gear grinding apparatus according to any one of claims 2 to 5, wherein a cavity is formed in the base metal at the center of rotation. A gear grinding tool used in a gear grinding device having an ultrasonic vibrator.
A base metal whose one end face is fixed to a booster connected to the ultrasonic vibrator and rotates,
The work has a cutting edge provided on the base metal and moves the work surface of the work in the tooth streak direction to grind the tooth surface on the work.
The cutting edge vibrates ultrasonically in the tooth profile with respect to the tooth surface by ultrasonic vibration oscillated from the ultrasonic vibrator and amplified by the booster.
A gear grinding tool characterized in that a small diameter portion having a diameter smaller than that of both end sides or a large diameter portion having a diameter larger than that of both end sides is formed in the center of the base metal in the direction of the rotation axis.

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