JP7619192B2 - Gear processing device and phase detection device - Google Patents

Description

The present invention relates to a gear machining device and a phase detection device.

Patent documents 1 to 3 describe gear machining devices that machine workpieces having multiple gear stages.

JP 2015-89600 A JP 2019-111610 A JP 2018-138319 A

When machining gears, for example, rough machining may be followed by hardening and finishing. When performing finishing, a workpiece with teeth formed by rough machining is attached to a workpiece spindle device, the tooth phase of the attached workpiece is detected, and the workpiece and the gear cutting tool are positioned based on the detected tooth phase of the workpiece, and the workpiece is then finished.

When a workpiece has multiple gear stages, it may be required that the deviation angle between the phase of any tooth of the first gear stage and the phase of any tooth of the second gear stage be within an acceptable range. For this reason, before finishing, the tooth combination that minimizes the deviation angle is found, and then finishing is performed based on the teeth of the combination.

Therefore, it is necessary to detect the phase of all the teeth of the first gear, detect the phase of all the teeth of the second gear, and find the combination that minimizes the deviation angle from the phase of all the teeth detected for each. In this case, since the phase of all the teeth of the first gear and the phase of all the teeth of the second gear are detected, a lot of time is required before finishing can be performed. This has led to the problem of a long machining cycle time.

The present invention was made in consideration of these problems, and aims to provide a gear cutting device that can shorten the cutting cycle time, and a phase detection device for use in gear cutting devices, etc.

One aspect of the present invention is
A gear machining device configured to machine at least one of a tooth surface of a first gear and a tooth surface of a second gear, the gear surface being a workpiece having a first gear with an equal tooth pitch angle and a second gear with a different number of teeth from that of the first gear, the gear machining device comprising:
a gear cutting tool having a plurality of tool blades in a circumferential direction;
a tool spindle device that rotatably holds the gear cutting tool;
a workpiece spindle device that rotatably holds the workpiece and is provided with a rotation angle detector that detects a rotation angle;
a moving device that moves the tool spindle device and the workpiece spindle device relatively;
a sensor that detects a radial distance to a peripheral surface of the first gear on the workpiece at a position radially opposed to the first gear on the workpiece while the workpiece is rotating with the workpiece spindle device holding the workpiece; and a sensor that detects a radial distance to a peripheral surface of the second gear on the workpiece at a position radially opposed to the second gear on the workpiece while the workpiece is rotating .
a control device that controls the moving device while synchronously controlling the rotation of the tool spindle device and the workpiece spindle device in order to machine gear teeth on the workpiece;
Equipped with
The control device includes:
a first detection process for detecting a phase of a first detection tooth, which is a part of all teeth of the first gear , based on the radial distance between the sensor and a peripheral surface of the first gear detected by the sensor and the rotation angle detected by the rotation angle detector of the workpiece spindle device;
a second detection process is executed to detect a phase of a second detection tooth, which is a part of all teeth of the second gear, based on the radial distance between the sensor and the peripheral surface of the second gear detected by the sensor and the rotation angle detected by the rotation angle detector of the workpiece spindle device;
execute a first phase calculation process to calculate a phase of a tooth of the first gear other than the first detection tooth based on the detected phase of the first detection tooth and a tooth pitch angle of the first gear stored in advance;
execute a second phase calculation process to calculate a phase of a tooth of the second gear other than the second detection tooth based on the detected phase of the second detection tooth and a tooth pitch angle of the second gear stored in advance;
executing a deviation angle calculation process to calculate deviation angles between the phases of the teeth of the first gear and the phases of the teeth of the second gear, based on the phases of all the teeth of the first gear obtained by the first detection process and the first phase calculation process and the phases of all the teeth of the second gear obtained by the second detection process and the second phase calculation process;
executing a determination process for determining, as a reference set, the phase of the teeth of the first gear and the phase of the teeth of the second gear that minimize the deviation angle;
a positioning process for controlling the tool spindle device and the workpiece spindle device in order to position the gear cutting tool and the workpiece using a tooth phase of the first gear and a tooth phase of the second gear constituting the reference set as a processing start reference;
The gear cutting device performs a processing process to control the moving device while synchronously controlling the rotation of the positioned gear cutting tool and the workpiece in order to process at least one of the tooth surfaces of the first gear and the second gear.

Another aspect of the present invention is
A phase detection device for an object having a first gear with an equal tooth pitch angle and a second gear with an equal tooth pitch angle different from the number of teeth of the first gear, the phase detection device determining, as a reference set, the tooth phases of the first gear and the tooth phases of the second gear that minimize deviation angles between the tooth phases of the first gear and the tooth phases of the second gear,
a sensor that detects a radial distance to a peripheral surface of the first gear on the object at a position radially opposed to the first gear on the object while the object is rotating, and detects a radial distance to a peripheral surface of the second gear on the object at a position radially opposed to the second gear on the object ;
a spindle device that rotatably holds the object and includes a rotation angle detector that detects a rotation angle;
a processing device that determines the reference set based on the detection results of the sensor and the detection results of the rotation angle detector of the spindle device;
Equipped with
The processing device includes:
a first detection process for detecting a phase of a first detection tooth, which is a part of all teeth of the first gear, based on the radial distance between the sensor and a peripheral surface of the first gear detected by the sensor and the rotation angle detected by the rotation angle detector of the spindle device;
a second detection process for detecting a phase of a second detection tooth, which is a part of all teeth of the second gear, based on the radial distance between the sensor and the peripheral surface of the first gear detected by the sensor and the rotation angle detected by the rotation angle detector of the spindle device;
execute a first phase calculation process to calculate a phase of a tooth of the first gear other than the first detection tooth based on the detected phase of the first detection tooth and a tooth pitch angle of the first gear stored in advance;
execute a second phase calculation process to calculate a phase of a tooth of the second gear other than the second detection tooth based on the detected phase of the second detection tooth and a tooth pitch angle of the second gear stored in advance;
executing a deviation angle calculation process to calculate deviation angles between the phases of the teeth of the first gear and the phases of the teeth of the second gear, based on the phases of all the teeth of the first gear obtained by the first detection process and the first phase calculation process and the phases of all the teeth of the second gear obtained by the second detection process and the second phase calculation process;
The phase detection device executes a determination process for determining, as the reference set, the phase of the teeth of the first gear and the phase of the teeth of the second gear that result in the smallest deviation angle.

According to the gear machining device of the above aspect, the first detection process detects the phase of a first detection tooth, which is a part of all teeth of the first gear, and the second detection process detects the phase of a second detection tooth, which is a part of all teeth of the second gear. In other words, the first detection process does not detect the phase of all teeth of the first gear, and the second detection process does not detect the phase of all teeth of the second gear. Therefore, the time required for detection can be significantly shorter than when all teeth are detected.

In the first detection process and the second detection process, the phase of all teeth is not detected, so there are remaining teeth whose phase has not been detected. The phase of the remaining teeth not detected by the sensor is found by calculation in the first phase calculation process and the second phase calculation process. Specifically, the first phase calculation process calculates the phase of the teeth on the first gear other than the first detected tooth based on the phase of the first detected tooth and the pre-stored tooth pitch angle of the first gear. The second phase calculation process calculates the phase of the teeth on the second gear other than the second detected tooth based on the second detected tooth and the pre-stored tooth pitch angle of the second gear.

The first gear and the second gear have equal tooth pitch angles. Therefore, the tooth pitch angle can be easily calculated once the number of teeth is known. Furthermore, since the multiple teeth on the first gear and the second gear are positioned at positions shifted by the respective tooth pitch angles, once the phase of one tooth is known, the phase of the remaining teeth can be easily calculated. Therefore, the time required to obtain the phase of all the teeth of the first gear and the phase of all the teeth of the second gear can be shortened. As a result, the machining cycle time can be shortened.

Furthermore, the phase detection device of the above aspect, like the gear processing device described above, can shorten the time required to obtain the phase of all the teeth of the first gear and the phase of all the teeth of the second gear. Therefore, it is possible to shorten the time required to determine the phase of the teeth of the first gear and the phase of the teeth of the second gear as a reference set when the deviation angle between each of the phases of the teeth of the first gear and each of the phases of the teeth of the second gear is minimum.

FIG. 1 is a diagram illustrating an example of a gear machining device. 1 is a view of the workpiece and tool viewed from a direction perpendicular to the rotation axis of the workpiece in the XZ plane, with the dashed line showing the tool indicating the position after gear machining has been performed on the workpiece. 1 is a view of the workpiece and the tool as viewed from the Y direction, and the dashed line showing the tool indicates the position after gear machining has been performed on the workpiece. FIG. 2 is a functional block diagram showing a partial configuration of the gear machining device. 4 is a flowchart showing a process performed by a control device. FIG. 13 is a diagram showing a partial configuration of a gear machining device when a phase of a first detection tooth of a first gear of a workpiece is detected by a sensor as a first detection process of the control device. FIG. 13 is a diagram showing an output waveform when a sensor detects the phase of a first detection tooth of a first gear of a workpiece in a first detection process of a control device. 13 is a development view of a first detection tooth and a portion of the remaining teeth of a first gear of a workpiece detected by a sensor in a first detection process of the control device. FIG. FIG. 11 is a diagram showing a partial configuration of the gear machining device when the phase of a second detection tooth on a second gear of the workpiece is detected by a sensor as a second detection process of the control device. FIG. 11 is a diagram showing an output waveform when the phase of a second detection tooth on a second gear of the workpiece is detected by a sensor in the second detection process of the control device. 13 is a development view of a second detection tooth and a portion of the remaining teeth of a second gear of a workpiece detected by a sensor in a second detection process of the control device. FIG. 13A and 13B are diagrams showing waveforms of all teeth of a first gear and waveforms of all teeth of a second gear calculated in a first phase calculation process and a second phase calculation process of a control device. FIG. 2 is a development view showing a reference set consisting of the tooth phase of the first gear and the tooth phase of the second gear that minimizes the deviation angle, and the teeth around it. FIG. 2 is a diagram showing a partial configuration of the gear machining apparatus, illustrating a state in which the sensor is not used for detection. 4 is a flowchart showing a processing process of the control device.

(1. Configuration of gear machining device 1)
The gear machining device 1 will be described with reference to Fig. 1. The gear machining device 1 is a device that generates a tooth profile (gear teeth) on the workpiece W by using the gear skiving cutter T by moving the workpiece W and a gear skiving cutter T relatively while rotating the workpiece W and the gear skiving cutter T as a gear cutting tool.

In this embodiment, the gear processing device 1 is a general-purpose machine tool, for example, a machining center. The machining center is configured to be tool-replaceable, and can perform processing according to the attached tool. For example, replaceable gear cutting tools include a gear skiving cutter T, a hob cutter, a shaper cutter, etc. By replacing with a hob cutter or a shaper cutter, the gear processing device 1 becomes a device that processes a tooth profile (gear teeth) on the workpiece W by hobbing or shaping.

In addition, examples of replaceable tools other than gear cutting tools include end mills, milling tools, drills, turning tools, threading tools, grinding tools, etc. Note that the tool changer and the tool magazine that stores multiple tools are not shown in FIG. 1.

In this embodiment, the machining center serving as the gear machining device 1 is basically a horizontal machining center. However, the gear machining device 1 can also be configured in other ways, such as a vertical machining center.

As shown in FIG. 1, the gear machining device 1 has, for example, three mutually orthogonal linear axes (X-axis, Y-axis, Z-axis) as drive axes. Here, the direction of the rotation axis of the gear skiving cutter T (equal to the rotation axis of the tool spindle) is defined as the Z-axis direction, and the two axes perpendicular to the Z-axis direction are defined as the X-axis and Y-axis. In FIG. 1, the horizontal direction is the X-axis direction, and the vertical direction is the Y-axis direction.

The gear processing device 1 further has one rotation axis (B axis) as a drive axis for changing the relative position between the workpiece W and the gear skiving cutter T. In this embodiment, the B axis is a rotation axis whose center of rotation is the Y axis direction. The gear processing device 1 also has a Ct axis as a rotation axis for rotating the gear skiving cutter T, and a Cw axis as a rotation axis for rotating the workpiece W.

In the gear processing device 1, the configuration for moving the workpiece W and the gear skiving cutter T relative to each other can be selected as appropriate. For example, the gear processing device 1 may be configured to have an A-axis with the X-axis direction as the center of rotation instead of the B-axis. In the following, an example is given of the gear processing device 1 in which the gear skiving cutter T can move linearly in the Y-axis and Z-axis directions, the workpiece W can move linearly in the X-axis direction, and the workpiece W can rotate about the B-axis.

The gear machining device 1 includes a bed 10, a workpiece holding device 20, a tool holding device 30, a sensor 40, and a control device 50. The bed 10 is installed on an installation surface and formed into a shape corresponding to the shape of the workpiece holding device 20 and the shape of the tool holding device 30. In this embodiment, the bed 10 is, for example, rectangular. On the upper surface of the bed 10, a pair of X-axis guide rails 11 extending in the X-axis direction and a pair of Z-axis guide rails 12 extending in the Z-axis direction are formed.

The workpiece holding device 20 allows the workpiece W to move linearly in the X-axis direction relative to the bed 10, and to rotate about the B-axis and Cw-axis. The workpiece holding device 20 mainly comprises an X-axis moving table 21, a B-axis rotating table 22, and a workpiece spindle device 23.

The X-axis moving table 21 is driven by a driving device such as a linear motor or a ball screw mechanism (not shown) and moves in the X-axis direction while being guided by the X-axis guide rail 11 of the bed 10. The B-axis rotating table 22 is placed on the upper surface of the X-axis moving table 21 and moves in the X-axis direction together with the X-axis moving table 21. The B-axis rotating table 22 is also provided so as to be rotatable on the B-axis relative to the X-axis moving table 21. A rotating motor (not shown) is housed in the B-axis rotating table 22, and the B-axis rotating table 22 can be rotated on the B-axis by driving the rotating motor.

The workpiece spindle device 23 is provided on the B-axis rotating table 22 and rotates about the B-axis integrally with the B-axis rotating table 22. The workpiece spindle device 23 holds the workpiece W rotatably. The workpiece spindle device 23 is provided with a rotation motor and a rotation angle detector, which will be described later, and the workpiece spindle device 23 is capable of rotating the workpiece W about the Cw axis by driving the rotation motor. In this way, the workpiece holding device 20 enables the workpiece W to be moved in the X-axis direction relative to the bed 10 and to be rotated about the B axis and the Cw axis.

In detail, the workpiece spindle device 23 includes a housing 23a and a spindle 23b. The housing 23a of the workpiece spindle device 23 is fixed to the B-axis rotating table 22, and the spindle 23b of the workpiece spindle device 23 is rotatably supported by the housing 23a. A workpiece W is attached to the tip of the spindle 23b. In other words, the workpiece W is cantilevered by the spindle 23b of the workpiece spindle device 23.

The tool holding device 30 mainly comprises a column 31, a saddle 32, and a tool spindle device 33. The column 31 is driven by a driving device such as a linear motor or a ball screw mechanism (not shown) and moves in the Z-axis direction while being guided by the Z-axis guide rail 12 of the bed 10. A Y-axis guide rail 31a is formed on the surface (left surface in FIG. 1) that extends in the vertical direction of the column 31. The saddle 32 is driven by a driving device such as a linear motor or a ball screw mechanism (not shown) and moves in the Y-axis direction while being guided by the Y-axis guide rail 31a of the column 31.

The tool spindle device 33 is mounted on the saddle 32 and moves integrally with the saddle 32 in the Y-axis direction. The tool spindle device 33 holds the gear skiving cutter T. A rotary motor (not shown) is housed in the tool spindle device 33, and the tool spindle device 33 can rotate the gear skiving cutter T on the Ct axis by driving the rotary motor. In this way, the tool holding device 30 holds the gear skiving cutter T so that it can move in the Y-axis and Z-axis directions relative to the bed 10 and can rotate on the Ct axis.

In detail, the tool spindle device 33 includes a housing 33a and a spindle 33b. The housing 33a of the tool spindle device 33 is fixed to the saddle 32, and the spindle 33b of the tool spindle device 33 is rotatably supported by the housing 33a. A gear skiving cutter T is attached to the tip of this spindle. In other words, the gear skiving cutter T is cantilevered on the spindle of the tool spindle device 33.

The sensor 40 is provided, for example, on the saddle 32. The sensor 40 is a sensor capable of detecting the distance between the teeth of the workpiece W when the workpiece spindle device 23 is holding the workpiece W and the workpiece W is rotating. The sensor 40 is preferably a non-contact distance sensor using, for example, eddy current or laser. However, it is also possible to use a contact sensor for the sensor 40. Since the sensor 40 is provided on the saddle 32, it moves together with the tool spindle device 33. The sensor 40 may also be provided so that the detection unit can move forward and backward.

The control device 50 is equipped with an arithmetic processing device (processor) and a storage device, and controls each drive device by executing a machining program. In other words, the control device 50 controls the rotation of the gear skiving cutter T, the rotation of the workpiece W, and the relative movement between the workpiece W and the gear skiving cutter T. The control device 50 then controls each drive device while synchronously controlling the rotation of the workpiece spindle device 23 and the tool spindle device 33 in order to machine gear teeth on the workpiece W.

(2. Configuration of gear skiving cutter T)
The configuration of the gear skiving cutter T will be described with reference to Figures 2 and 3. The gear skiving cutter T includes a blade portion Ta and a shaft portion Tb.

The blade portion Ta has multiple tool blades in the circumferential direction. The axial end faces of the multiple tool blades in the blade portion Ta form the rake faces, and the radial outer surfaces of the tool blades form the relief faces. In this embodiment, the circumscribing surface of the blade portion Ta, i.e., the surface connecting the radial outer surfaces of the tool blades, which are the relief faces, forms a conical surface. However, the circumscribing surface of the blade portion Ta can also be configured to form a cylindrical surface. The shaft portion Tb is integrally provided on the back side of the rake faces of the blade portion Ta and is provided coaxially with the blade portion Ta. The shaft portion Tb is attached to the spindle 33b (shown in FIG. 1) of the tool spindle device 33.

(3. Configuration of Workpiece W)
An example of the configuration of the workpiece W will be described with reference to Fig. 2. As shown in Fig. 2, the workpiece W has multiple stages of gears in the axial direction. In this embodiment, the workpiece W has two stages of gears, that is, a first gear W1 and a second gear W2. However, the workpiece W may have three or more stages of gears.

The first gear W1 is formed with an equal tooth pitch angle. The second gear W2 is also formed with an equal tooth pitch angle. The number of teeth of the first gear W1 is different from the number of teeth of the second gear W2. In this embodiment, as shown in FIG. 2, the first gear W1 is formed with a larger diameter than the second gear W2, but the first gear W1 and the second gear W2 may be formed with the same diameter.

(4. Explanation of gear skiving)
The state in which a tooth profile (gear teeth) is generated on a workpiece W by the gear skiving cutter T will be described with reference to Figs. 2 and 3 .

In this embodiment, the gear processing device 1 is used for a workpiece W on which a first gear W1 and a second gear W2 have been formed in advance. The gear processing device 1 is configured to process at least one of the preformed tooth surfaces of the first gear W1 and the preformed tooth surfaces of the second gear W2. In this embodiment, the gear processing device 1 processes the preformed tooth surface of the first gear W1 and also processes the preformed tooth surface of the second gear W2. For example, the gear processing device 1 performs finish processing on the tooth surfaces of the first gear W1 and the second gear W2.

Figures 2 and 3 show the case where gear skiving is performed on the tooth surface of the second gear W2 in the workpiece W using a gear skiving cutter T. Note that the case where gear skiving is performed on the tooth surface of the first gear W1 using a gear skiving cutter T is substantially the same.

As shown in Figure 3, in gear skiving processing, the rotation axis At of the gear skiving cutter T is set at an intersection angle θ with an axis parallel to the rotation axis Aw of the workpiece W. Also, as shown in Figure 2, the rotation axis At of the gear skiving cutter T and the rotation axis Aw of the workpiece W are parallel to the X-Z plane. As shown in Figure 2, the center-to-center distance between the rotation axis At of the gear skiving cutter T and the rotation axis Aw of the workpiece W, i.e., the distance in the Y-axis direction, is Da.

The workpiece W is rotated around the rotation axis Aw (Cw axis), and the gear skiving cutter T is rotated around the rotation axis At (Ct axis). The gear skiving cutter T is moved relative to the workpiece W in the direction of the rotation axis Aw of the workpiece W while synchronizing the rotation of the workpiece W and the rotation of the gear skiving cutter T, thereby generating a tooth profile on the workpiece W. In gear skiving, each tooth groove portion of the workpiece W is machined only once by the gear skiving cutter T while the workpiece W rotates once.

In addition to the above-mentioned finishing processes, the present invention can also be applied to machining chamfers for synchromesh mechanisms to facilitate smooth shift changes in a vehicle's manual transmission. In other words, the gear machining device 1 may machine chamfers for synchromesh mechanisms on the tooth surfaces of the first gear W1 and second gear W2 that have been formed in advance. Because the chamfers are formed on a portion of each tooth surface in the axial direction, the gear machining device 1 machines only a portion of the tooth surfaces of the first gear W1 and second gear W2.

(5. Functional Block Configuration of Gear Machining Device 1)
Next, functions of a portion of the configuration of the gear machining device 1 will be described with reference to Fig. 4. As shown in Fig. 4, the gear machining device 1 includes an X-axis moving device 61 for relatively moving the workpiece W and the gear skiving cutter T in the X-axis direction, a Y-axis moving device 62 for relatively moving them in the Y-axis direction, and a Z-axis moving device 63 for relatively moving them in the Z-axis direction.

In this embodiment, the X-axis moving device 61 is a driving device such as a linear motor or a ball screw mechanism for moving the X-axis moving table 21 in the X-axis direction relative to the bed 10. The Y-axis moving device 62 is a driving device such as a linear motor or a ball screw mechanism for moving the saddle 32 in the Y-axis direction relative to the column 31. The Z-axis moving device 63 is a driving device such as a linear motor or a ball screw mechanism for moving the column 31 in the Z-axis direction relative to the bed 10. Although not shown, the X-axis moving device 61, the Y-axis moving device 62, and the Z-axis moving device 63 are configured with a driving circuit, a motor (linear motor or rotary motor), a position detector (linear position detector or rotation angle detector), etc.

Furthermore, as shown in FIG. 4, the gear machining device 1 includes a workpiece spindle device 23, a tool spindle device 33, and a rotation device 64. As described above, the workpiece spindle device 23 constitutes the workpiece holding device 20 and holds the workpiece W rotatably around the Cw axis. The workpiece spindle device 23 includes a drive circuit 23c, a rotation motor 23d, and a rotation angle detector 23e.

As described above, the tool spindle device 33 constitutes the tool holding device 30 and holds the gear skiving cutter T rotatably around the Ct axis. Although not shown, the tool spindle device 33 is configured with a drive circuit, a rotation motor, and a rotation angle detector. The rotation device 64 is a moving device for changing the attitude of the workpiece W and the gear skiving cutter T. In this embodiment, the rotation device 64 includes a rotation motor for rotating the B-axis rotating table 22 about the B axis relative to the X-axis moving table 21. Furthermore, the rotation device 64 is configured with a drive circuit, a rotation angle detector, and the like in addition to the rotation motor.

The sensor 40 detects the distance between the teeth of the first gear W1 preformed on the workpiece W while the workpiece W is rotating. However, the sensor 40 does not detect all the teeth of the first gear W1, but only some of the teeth of the first gear W1. The sensor 40 also detects the distance between the teeth of the second gear W2 preformed on the workpiece W while the workpiece W is rotating. However, the sensor 40 does not detect all the teeth of the second gear W2, but only some of the teeth of the second gear W2.

The control device 50 controls the sensor 40 to detect the distance between the workpiece W and some of the teeth of the first gear W1 and the distance between the workpiece W and some of the teeth of the second gear W2 while the workpiece W is rotating. To perform detection by the sensor 40, the control device 50 controls the X-axis moving device 61, the Y-axis moving device 62, and the Z-axis moving device 63 as moving devices, and further controls the workpiece spindle device 23.

The control device 50 detects the phase of some of the teeth of the first gear W1 and the phase of some of the teeth of the second gear W2 based on the detection results of the sensor 40 and the rotation angle detector 23e of the workpiece spindle device 23. For example, the control device 50 makes the detection time of the sensor 40 correspond to the detection time of the rotation angle detector 23e. The control device 50 then detects the phase of some of the teeth of the first gear W1 and the phase of some of the teeth of the second gear W2 based on the distance detected by the sensor 40 and the rotation angle of the rotary motor 23d detected by the rotation angle detector 23e. The control device 50 then calculates information for machining the workpiece W based on the phase of some of the teeth of the first gear W1 and the phase of some of the teeth of the second gear W2.

The control device 50 also controls the X-axis moving device 61, the Y-axis moving device 62, and the Z-axis moving device 63 as moving devices to machine the workpiece W, and further controls the workpiece spindle device 23, the tool spindle device 33, and the rotation device 64.

(6. Processing of the control device 50)
The process (control method) of the control device 50 will be described with reference to Figures 5 to 15. With the workpiece W held by the workpiece spindle device 23 and the workpiece W rotating, the control device 50 executes a first detection process (first detection step ST1) to detect the phase of a first detection tooth Wd1 (shown in Figure 8), which is a part of all the teeth of the first gear W1, using the sensor 40 and the rotation angle detector 23e.

To execute the first detection process, the control device 50 first positions the workpiece W and the sensor 40 at the positions shown in FIG. 6. Here, as shown in FIG. 6, the sensor 40 includes a detection unit 41 and a support unit 42 that supports the detection unit 41. The detection unit 41 of the sensor 40 is, for example, a non-contact distance sensor such as an eddy current or laser. The support unit 42 of the sensor 40 has a base end that is provided on the saddle 32, and holds the detection unit 41 at its tip. The support unit 42 of the sensor 40 is provided so as to be movable forward and backward with respect to the saddle 32. As shown in FIG. 6, the control device 50 extends the support unit 42 of the sensor 40 to bring the detection unit 41 of the sensor 40 into an advanced state.

Furthermore, the control device 50 controls the X-axis moving device 61, the Y-axis moving device 62, and the Z-axis moving device 63 as moving devices so that the detection unit 41 of the sensor 40 faces the first gear W1 in the radial direction of the first gear W1, as shown in FIG. 6. In other words, the detection unit 41 of the sensor 40 coincides with the axial position of the first gear W1 on the workpiece W, and the distance between the detection unit 41 of the sensor 40 and the first gear W1 is within the detectable range of the sensor 40.

Then, the control device 50 controls the workpiece spindle device 23 to rotate the workpiece W. At this time, the control device 50 sets the rotation angle of the workpiece W to an angle smaller than one revolution, rather than one revolution. Furthermore, the control device 50 acquires the detection result of the rotation angle detector 23e.

Through the first detection process, the sensor 40 detects the distance of the first detection tooth Wd1 (shown in FIG. 8), which is a part of all the teeth on the first gear W1, while the workpiece W is rotating. At the same time, the rotation angle detector 23e detects the rotation angle of the rotation motor 23d. The control device 50 then obtains the detection time of the sensor 40 in correspondence with the detection time of the rotation angle detector 23e. In other words, the phase of the first detection tooth Wd1 is detected by the sensor 40 and the rotation angle detector 23e.

The output waveform H1, which is the detection result by the sensor 40 at this time, is as shown in FIG. 7. As shown in FIG. 7 and FIG. 8, the peak value in the detection value of the sensor 40 corresponds to the tooth bottom. Also, in FIG. 7, the horizontal axis is the rotation angle of the workpiece W obtained from the rotation angle detector 23e (corresponding to the rotation angle of the rotation motor 23d).

In addition, in the first detection process, as shown in Figures 7 and 8, an angle range φd1 smaller than one revolution of the first gear W1 is detected. For example, the first detection process detects the phase of a plurality of first detection teeth Wd1 that are a portion of all the teeth in the first gear W1. For example, the first detection process detects the phase of the first detection teeth Wd1 for three teeth in the first gear W1.

For example, the first detection process detects the bottom phases of the first detection teeth Wd1 of multiple teeth. As shown in Figures 7 and 8, in the first detection process, the sensor 40 detects bottom phases P1a, P1b, and P1c of the first detection teeth Wd1 of three teeth. The detection value of the sensor 40 is large for bottoms located farther from the detection unit 41 of the sensor 40 and small for tips located closer to the detection unit 41.

The control device 50 may detect the phase of one of the first detection teeth Wd1 among all the teeth of the first gear W1 in the first detection process. In this case, in FIG. 7 and FIG. 8, only the root phase P1a of one of the first detection teeth Wd1 is detected in the first detection process. The control device 50 may also detect the tip phase of the first detection tooth Wd1 instead of the root phase in the first detection process.

As shown in FIG. 5, following the first detection process, the control device 50 executes a second detection process (second detection step ST2) in which, while the workpiece spindle device 23 is holding the workpiece W and the workpiece W is rotating, the sensor 40 and the rotation angle detector 23e are used to detect the phase of the second detection tooth Wd2, which is a portion of all the teeth in the second gear W2. The second detection process may be executed before the first detection process.

To execute the second detection process, the control device 50 first positions the workpiece W and the sensor 40 at the positions shown in FIG. 9. As shown in FIG. 9, the control device 50 controls the X-axis moving device 61, the Y-axis moving device 62, and the Z-axis moving device 63 as moving devices so that the detection unit 41 of the sensor 40 faces the second gear W2 in the radial direction of the second gear W2. In other words, the detection unit 41 of the sensor 40 coincides with the axial position of the second gear W2 on the workpiece W, and the separation distance between the detection unit 41 of the sensor 40 and the second gear W2 is within the detectable range of the sensor 40. At this time, the control device 50 extends the support portion 42 of the sensor 40 as shown in FIG. 9, so that the detection unit 41 of the sensor 40 is advanced.

Then, the control device 50 controls the workpiece spindle device 23 to rotate the workpiece W. At this time, the control device 50 sets the rotation angle of the workpiece W to an angle smaller than one revolution, rather than one revolution. Furthermore, the control device 50 acquires the detection result of the rotation angle detector 23e.

By the second detection process, the sensor 40 detects the distance of the second detection tooth Wd2 (shown in FIG. 12), which is a part of all the teeth on the second gear W2, while the workpiece W is rotating. At the same time, the rotation angle detector 23e detects the rotation angle of the rotation motor 23d. The control device 50 then obtains the detection time of the sensor 40 in correspondence with the detection time of the rotation angle detector 23e. In other words, the phase of the second detection tooth Wd2 is detected by the sensor 40 and the rotation angle detector 23e.

The output waveform H2, which is the detection result by the sensor 40 at this time, is as shown in Figure 10. As shown in Figures 10 and 11, the peak value in the detection value of the sensor 40 corresponds to the tooth bottom. Also, in Figure 10, the horizontal axis is the rotation angle of the workpiece W obtained from the rotation angle detector 23e (corresponding to the rotation angle of the rotation motor 23d).

In addition, in the second detection process, as shown in Figures 10 and 11, an angle range φd2 smaller than one revolution of the second gear W2 is detected. For example, the second detection process detects the phase of a plurality of second detection teeth Wd2 that are a portion of all the teeth in the second gear W2. For example, the second detection process detects the phase of the second detection teeth Wd2 for three teeth in the second gear W2.

For example, the second detection process detects the bottom phases of the second detection teeth Wd2 of multiple teeth. As shown in Figures 10 and 11, in the second detection process, the sensor 40 detects bottom phases P2a, P2b, and P2c of the second detection teeth Wd2 of three teeth. The detection value of the sensor 40 is large for bottoms located farther from the detection unit 41 of the sensor 40 and small for tips located closer to the detection unit 41.

The control device 50 may detect the phase of one second detection tooth Wd2 among all the teeth of the second gear W2 in the second detection process. In this case, in FIG. 10 and FIG. 11, only the root phase P2a of one second detection tooth Wd2 is detected in the second detection process. The control device 50 may also detect the tip phase of the second detection tooth Wd2 instead of the root phase in the second detection process.

As shown in FIG. 5, following the second detection process, the control device 50 executes a first phase calculation process (first phase calculation step ST3). Note that the first phase calculation process may be executed after the first detection process and before the second detection process.

The first phase calculation process calculates phases P1d-P1g, ... (shown in the upper part of Figure 12) of teeth Wc1 (shown in Figure 8) other than the first detection tooth Wd1 of the first gear W1 based on the phase of the first detection tooth Wd1 detected in the first detection process (ST1) and the pre-stored tooth pitch angle Pit1 of the first gear W1. As described above, the first detection process (ST1) detected the phase of the first detection tooth Wd1 located in an angle range φd1 smaller than one revolution of the first gear W1. Therefore, the first phase calculation process (ST3) calculates phases P1d-P1g, ... of the remaining teeth Wc1 of the first gear W1, taking into account the phase of the first detection tooth Wd1.

Here, in the first detection process described above, the phases P1a, P1b, and P1c of the multiple first detection teeth Wd1 were detected. Therefore, in the first phase calculation process, first, the phase P1a' of a specific one of the multiple first detection teeth Wd1 is calculated based on the phases P1a, P1b, and P1c of the multiple first detection teeth Wd1 and the tooth pitch angle Pit1 of the first gear W1.

Because the first gear W1 is an equal-angle gear, the tooth pitch angle Pit1 of the first gear W1 can be determined from the number of teeth of the first gear W1. For example, if the number of teeth of the first gear W1 is 31, the tooth pitch angle Pit1 is 11.612°. The tooth pitch angle Pit1 of the first gear W1 is pre-stored in the control device 50.

Then, the phase P1a' of one specific first detection tooth Wd1 is calculated, for example, according to equation (1).
P1a'={P1a+(P1b-Pit1)+(P1c-2×Pit1)}/3
... (1)

The phase P1a' of one specific first detection tooth Wd1 obtained from formula (1) corresponds to the average value of the phases P1a, P1b, and P1c of multiple first detection teeth Wd1. For example, the tooth pitch angle Pit1 of the first gear W1 before this processing may be shifted due to differences in the amount of deformation caused by heat treatment in the previous process. Therefore, by averaging using the phases P1a, P1b, and P1c of multiple first detection teeth Wd1 as in formula (1), it is possible to average out the differences in deformation caused by heat treatment, etc.

Next, in the first phase calculation process, as shown in the upper part of Figure 12, phases P1d-P1g, ... of the teeth Wc1 of the first gear W1 other than the first detection tooth Wd1 are calculated based on the phase P1a' of a specific first detection tooth Wd1 and the tooth pitch angle Pit1 of the first gear W1. The phases P1d-P1g, ... of the teeth Wc1 can be found by sequentially adding the tooth pitch angle Pit1 to the phase P1a' of the specific first detection tooth Wd1.

As described above, the first detection process may detect the phase P1a of only one first detection tooth Wd1, rather than the phases P1a, P1b, and P1c of the multiple first detection teeth Wd1. In this case, the first phase calculation process may calculate the phases P1d-P1g, ... of the teeth Wc1 of the first gear W1 other than the first detection tooth Wd1, based on the detected phase P1a of the one first detection tooth Wd1 and the tooth pitch angle Pit1.

As shown in FIG. 5, the control device 50 executes the second phase calculation process following the first phase calculation process (second phase calculation step ST4). Note that the second phase calculation process may be executed after the second detection process, or may be executed before the first phase calculation process.

The second phase calculation process calculates phases P2d-P2j, ... (shown in the lower part of Figure 12) of teeth Wc2 (shown in Figure 11) other than the second detection tooth Wd2 of the second gear W2 based on the phase of the second detection tooth Wd2 detected in the second detection process (ST2) and the pre-stored tooth pitch angle Pit2 of the second gear W2. As described above, the second detection process (ST2) detected the phase of the second detection tooth Wd2 located in an angle range φd2 smaller than one revolution of the second gear W2. Therefore, in the second phase calculation process (ST4), the phases P2d-P2j, ... of the remaining teeth Wc2 of the second gear W2 are calculated taking into account the phase of the second detection tooth Wd2.

Here, in the second detection process described above, the phases P2a, P2b, and P2c of the multiple second detection teeth Wd2 were detected. Therefore, in the second phase calculation process, first, the phase P2a' of a specific one of the multiple second detection teeth Wd2 is calculated based on the phases P2a, P2b, and P2c of the multiple second detection teeth Wd2 and the tooth pitch angle Pit2 of the second gear W2.

Since the second gear W2 is an equal-angle gear, the tooth pitch angle Pit2 of the second gear W2 can be determined from the number of teeth of the second gear W2. For example, if the number of teeth of the second gear W2 is 15, the tooth pitch angle Pit2 is 24°. The tooth pitch angle Pit2 of the second gear W2 is pre-stored in the control device 50.

Then, the phase P2a' of one specific second detection tooth Wd2 is calculated, for example, according to equation (2).
P2a'={P2a+(P2b-Pit2)+(P2c-2×Pit2)}/3
... (2)

The phase P2a' of one specific second detection tooth Wd2 obtained from equation (2) corresponds to the average value of the phases P2a, P2b, and P2c of multiple second detection teeth Wd2. For example, the tooth pitch angle Pit2 of the second gear W2 before this processing may be shifted due to differences in the amount of deformation caused by heat treatment in the previous process. Therefore, by averaging using the phases P2a, P2b, and P2c of multiple second detection teeth Wd2 as in equation (2), it is possible to average out the differences in deformation caused by heat treatment, etc.

Next, in the second phase calculation process, as shown in the lower part of Figure 12, the phases P2d-P2j, ... of the teeth Wc2 of the second gear W2 other than the second detection tooth Wd2 are calculated based on the phase P2a' of one specific second detection tooth Wd2 and the tooth pitch angle Pit2 of the second gear W2. The phases P2d-P2j, ... of the teeth Wc2 can be found by sequentially adding the tooth pitch angle Pit2 to the phase P2a' of one specific second detection tooth Wd2.

As described above, the second detection process may detect the phase P2a of only one second detection tooth Wd2, rather than the phases P2a, P2b, and P2c of the multiple second detection teeth Wd2. In this case, the second phase calculation process may calculate the phases P2d to P2j, ... of the teeth Wc2 of the second gear W2 other than the second detection tooth Wd2, based on the detected phase P2a of the one second detection tooth Wd2 and the tooth pitch angle Pit2.

As shown in FIG. 5, following the second phase calculation process, the control device 50 executes a deviation angle calculation process (deviation angle calculation step ST5). The deviation angle calculation process compares the phase of all teeth of the first gear W1 with the phase of all teeth of the second gear W2, and calculates the deviation angle between each of the tooth phases of the first gear W1 and each of the tooth phases of the second gear W2.

Here, the phases of all the teeth of the first gear W1 are the phases P1a, P1b, P1c of the first detected tooth Wd1 obtained by the first detection process, and the phases P1d to P1g, ... of the remaining teeth Wc1 obtained by the first phase calculation process.

In FIG. 12, the deviation angle between the bottom phase P1d of the first gear W1 and the bottom phase P2e of the second gear W2, which is closest to the bottom phase P1d of the first gear W1, is ΔP1d. The deviation angle between the bottom phase P1g of the first gear W1 and the bottom phase P2j of the second gear W2, which is closest to the bottom phase P1g of the first gear W1, is ΔP1g. In this way, the deviation angles are compared between the closest teeth.

When the tip phase of the first gear W1 is obtained by the first detection process and the first phase calculation process, and the tip phase of the second gear W2 is obtained by the second detection process and the second phase calculation process, the deviation angle is the deviation angle between the tip phases. In addition, the deviation angle between the tip phase of the first gear W1 and the root phase of the second gear can also be used, or the deviation angle between the root phase of the first gear W1 and the tip phase of the second gear can also be used.

As shown in FIG. 5, the control device 50 executes a judgment process following the deviation angle calculation process (judgment step ST6). In the judgment process, the tooth phase of the first gear W1 and the tooth phase of the second gear W2 that have the smallest deviation angle among the respective deviation angles are judged as a reference set. In FIG. 12, the deviation angle ΔP1g between the bottom phase P1g of the first gear W1 and the bottom phase P2j of the second gear W2 that is closest to the bottom phase P1g of the first gear W1 is smallest. Therefore, as shown in FIG. 12 and FIG. 13, the bottom phase P1g of the first gear W1 and the bottom phase P2j of the second gear W2 are the reference set.

When the deviation angle of the tooth tip phase is obtained in the deviation angle calculation process, the judgment process determines the reference set with the smallest deviation angle between the tooth tip phases. Of course, when the deviation angle between the root phase of the first gear W1 and the tip phase of the second gear W2 is obtained in the deviation angle calculation process, the judgment process determines the reference set with the smallest deviation angle.

As shown in FIG. 5, following the determination process, the control device 50 executes a positioning process (positioning step ST7). The positioning process controls the workpiece spindle device 23 and the tool spindle device 33 to position the gear skiving cutter T and the workpiece W using the tooth root phase P1g of the first gear W1 and the tooth root phase P2j of the second gear W2, which constitute the reference set, as the machining start reference.

Here, in the positioning process before starting machining, as shown in FIG. 14, the support portion 42 of the sensor 40 is contracted and the detection portion 41 of the sensor 40 is retracted. In other words, when machining the workpiece W with the gear skiving cutter T, the sensor 40 moves to a position where it does not interfere with the workpiece W.

As shown in FIG. 5, the control device 50 executes the machining process following the positioning process (machining step ST8). In the machining process, the gear skiving cutter T machines the tooth surfaces of the first gear W1 and the second gear W2 of the workpiece W according to the machining program. The machining order may be such that the first gear W1 is machined and then the second gear W2 is machined, or vice versa. However, there may also be cases where machining is performed on only one of the tooth surfaces of the first gear W1 and the second gear W2.

The processing (processing method) will now be described with reference to FIG. 15. The control device 50 determines whether the deviation angle in the reference set determined in the determination process is less than the allowable range (allowable range determination step ST11). As described above, the deviation angle in the reference set is the smallest deviation angle among the deviation angles between each of the tooth root phases of the first gear W1 and each of the tooth root phases of the second gear W2.

If the deviation angle of the reference set is less than the allowable range (ST11: Yes), the control device 50 processes the tooth surface of the first gear W1 without performing the correction described below (first gear machining step ST12). In other words, the machining process by the control device 50 controls the moving devices 61, 62, 63, and 64 while synchronously controlling the rotation of the positioned gear skiving cutter T and the workpiece W in order to machine the tooth surface of the first gear W1. In this way, the tooth surface of the first gear W1 is machined.

Next, when the machining of the first gear W1 is completed, the control device 50 machines the tooth surface of the second gear W2 without performing the correction described below (second gear machining step ST13). In other words, the machining process by the control device 50 controls the moving devices 61, 62, 63, and 64 while synchronously controlling the rotation of the positioned gear skiving cutter T and the workpiece W in order to machine the tooth surface of the second gear W2. In this way, the tooth surface of the second gear W2 is machined.

On the other hand, if the deviation angle of the reference set is equal to or greater than the allowable range (ST11: No), the processing of the control device 50 calculates and sets a correction value (correction value setting step ST14). The correction here is a process for reducing the deviation angle of the reference set after processing. The correction value may be set for both the processing of the first gear W1 and the processing of the second gear W2, or may be set for the processing of either the first gear W1 or the second gear W2. For example, if the deviation angle is large, the correction value is set for both the first gear W1 and the second gear W2, and if the deviation angle is small, the correction value is set for either the first gear W1 or the second gear W2.

When a correction value is set for machining the first gear W1, the control device 50 performs machining on the tooth surface of the first gear W1 while making corrections based on the correction value (first gear machining step ST12). In other words, the machining process of the control device 50 performs machining by making corrections to the workpiece spindle device 23 and the tool spindle device 33 so that the deviation angle in the reference set is reduced.

Next, if a correction value has been set for machining the second gear W2, when machining of the first gear W1 is completed, the control device 50 performs machining on the tooth surface of the second gear W2 while making corrections based on the correction value (second gear machining step ST13). In other words, the machining process of the control device 50 performs machining by making corrections to the workpiece spindle device 23 and the tool spindle device 33 so as to reduce the deviation angle in the reference set.

Therefore, if the deviation angle in the reference set is greater than the allowable range, the machining is performed while making corrections, so that the deviation angle in the reference set between the first gear W1 and the second gear W2 after machining is reduced.

(7. Effects)
According to the above-described gear machining device 1, the first detection process detects phases P1a, P1b, and P1c of the first detection tooth Wd1, which is a part of all the teeth of the first gear W1, and the second detection process detects phases P2a, P2b, and P2c of the second detection tooth Wd2, which is a part of all the teeth of the second gear W2. In other words, the first detection process does not detect the phases of all the teeth of the first gear W1, and the second detection process does not detect the phases of all the teeth of the second gear W2. Therefore, the time required for detection can be significantly shorter than when all the teeth are detected.

In the first and second detection processes, the phases of all teeth are not detected, so there are remaining teeth Wc1 and Wc2 whose phases have not been detected. The phases P1d-P1g, ..., P2d-P2j, ... of the remaining teeth Wc1 and Wc2 that are not detected by the sensor 40 are found by calculation in the first and second phase calculation processes. Specifically, the first phase calculation process calculates the phases P1d-P1g, ... of the teeth Wc1 other than the first detection tooth Wd1 in the first gear W1 based on the phases P1a, P1b, P1c of the first detection tooth Wd1 and the pre-stored tooth pitch angle Pit1 of the first gear W1. The second phase calculation process calculates the phases P2d-P2j, ... of the teeth Wc2 other than the second detection tooth Wd2 in the second gear W2 based on the second detection tooth Wd2 and the pre-stored tooth pitch angle Pit2 of the second gear W2.

The first gear W1 and the second gear W2 have equal tooth pitch angles Pit1 and Pit2. Therefore, the tooth pitch angles Pit1 and Pit2 can be easily calculated once the number of teeth is known. Furthermore, since the multiple teeth on the first gear W1 and the second gear W2 are positioned at positions shifted by the respective tooth pitch angles Pit1 and Pit2, once the phase of one tooth is known, the phase of the remaining teeth can be easily calculated. Therefore, the time required to obtain the phase of all the teeth of the first gear W1 and the phase of all the teeth of the second gear W2 can be shortened. As a result, the processing cycle time can be shortened.

The first phase calculation process uses the phases P1a, P1b, and P1c of the multiple first detection teeth Wd1 to calculate the phase P1a' of one specific first detection tooth Wd1 among the multiple first detection teeth Wd1. In this way, by using the phases P1a, P1b, and P1c of the multiple first detection teeth Wd1, the influence of the deviation of each phase P1a, P1b, and P1c can be reduced. For example, even if differences in deformation occur due to heat treatment, the influence of the differences in deformation can be reduced by calculating the phase P1a' of one specific first detection tooth Wd1. The same is true for the second phase calculation process.

In addition, if the deviation angle of the reference set is greater than or equal to the tolerance range during processing, a correction is made. By making such correction, it is possible to ensure that the deviation angle of the reference set after processing falls below the tolerance range.

(8. Other Examples)
The above describes the gear machining device 1. Here, it is possible to extract only the process of determining the reference set in the gear machining device 1 and grasp it as a phase detection device (1).

The phase detection device (1) determines the phase of the teeth of the first gear W1 and the phase of the teeth of the second gear W2, which are the reference set, for an object having a first gear W1 and a second gear W2. In other words, the phase detection device (1) determines the phase of the teeth of the first gear W1 and the phase of the teeth of the second gear W2, which have the smallest deviation angle, as the reference set.

The phase detection device (1) includes a sensor 40, a rotation angle detector 23e, and a processing device (50) that is part of the control device 50 described above. The processing by the processing device (50) is similar to the processing by the control device 50 described above, ST1 to ST6 (shown in FIG. 5), and therefore will not be described here.

The phase detection device (1) determines the tooth phase of the first gear W1 and the tooth phase of the second gear W2, which are the reference set, and can be applied to the gear processing device 1 as described above, and can also be applied to product inspection, etc., in addition to the gear processing device 1. In this case, the product inspection is, for example, an inspection to clearly indicate the reference set when the tooth phase of the first gear W1 and the tooth phase of the second gear W2, which are the reference set, are clearly indicated before shipping.

The phase detection device (1), like the gear processing device 1 described above, can shorten the time required to obtain the phases of all the teeth of the first gear W1 and the phases of all the teeth of the second gear W2. Therefore, it is possible to shorten the time required to determine the phases of the teeth of the first gear W1 and the second gear W2 as a reference set when the deviation angles between the phases of the teeth of the first gear W1 and the phases of the teeth of the second gear W2 are minimum.

1 Gear machining device, phase detection device 23 Workpiece spindle device 23e Rotation angle detector 33 Tool spindle device 40 Sensor 50 Control device, processing device 61 to 64 Movement device ST1 First detection process ST2 Second detection process ST3 First phase calculation process ST4 Second phase calculation process ST5 Deviation angle calculation process ST6 Judgment process ST7 Positioning process ST8 Machining process T Gear skiving cutter W Workpiece W1 First gear W2 Second gear Wd1 First detection tooth Wd2 Second detection tooth

Claims (9)

A gear machining device configured to machine at least one of a tooth surface of the first gear and a tooth surface of the second gear, the gear surface being a workpiece having a first gear with an equal tooth pitch angle and a second gear with a different number of teeth from the first gear and an equal tooth pitch angle, the gear machining device comprising:
a gear cutting tool having a plurality of tool blades in a circumferential direction;
a tool spindle device that rotatably holds the gear cutting tool;
a workpiece spindle device that rotatably holds the workpiece and is provided with a rotation angle detector that detects a rotation angle;
a moving device that moves the tool spindle device and the workpiece spindle device relatively;
a sensor that detects a radial distance to a peripheral surface of the first gear on the workpiece at a position radially opposed to the first gear on the workpiece while the workpiece is rotating with the workpiece spindle device holding the workpiece; and a sensor that detects a radial distance to a peripheral surface of the second gear on the workpiece at a position radially opposed to the second gear on the workpiece while the workpiece is rotating .
a control device that controls the moving device while synchronously controlling the rotation of the tool spindle device and the workpiece spindle device in order to machine gear teeth on the workpiece;
Equipped with
The control device includes:
a first detection process for detecting a phase of a first detection tooth, which is a part of all teeth of the first gear , based on the radial distance between the sensor and a peripheral surface of the first gear detected by the sensor and the rotation angle detected by the rotation angle detector of the workpiece spindle device;
a second detection process is executed to detect a phase of a second detection tooth, which is a part of all teeth of the second gear, based on the radial distance between the sensor and the peripheral surface of the second gear detected by the sensor and the rotation angle detected by the rotation angle detector of the workpiece spindle device;
execute a first phase calculation process to calculate a phase of a tooth of the first gear other than the first detection tooth based on the detected phase of the first detection tooth and a tooth pitch angle of the first gear stored in advance;
execute a second phase calculation process to calculate a phase of a tooth of the second gear other than the second detection tooth based on the detected phase of the second detection tooth and a tooth pitch angle of the second gear stored in advance;
executing a deviation angle calculation process to calculate deviation angles between the phases of the teeth of the first gear and the phases of the teeth of the second gear, based on the phases of all the teeth of the first gear obtained by the first detection process and the first phase calculation process and the phases of all the teeth of the second gear obtained by the second detection process and the second phase calculation process;
executing a determination process for determining, as a reference set, the phase of the teeth of the first gear and the phase of the teeth of the second gear that minimize the deviation angle;
a positioning process for controlling the tool spindle device and the workpiece spindle device in order to position the gear cutting tool and the workpiece using a tooth phase of the first gear and a tooth phase of the second gear constituting the reference set as a processing start reference;
A gear machining device that performs a machining process by controlling the moving device while synchronously controlling the rotation of the positioned gear cutting tool and the workpiece in order to machine at least one of the tooth surfaces of the first gear and the second gear. the deviation angle calculation process calculates deviation angles between each of the tooth tip phases of the first gear and each of the tooth tip phases of the second gear,
2. The gear machining device according to claim 1, wherein the determination process determines, as the reference set, a tooth tip phase of the first gear and a tooth tip phase of the second gear when a deviation angle between the tooth tip phase of the first gear and the tooth tip phase of the second gear is minimum. the deviation angle calculation process calculates deviation angles between each of the tooth root phases of the first gear and each of the tooth root phases of the second gear,
2. The gear machining device according to claim 1, wherein the determination process determines, as the reference set, a bottom phase of the first gear and a bottom phase of the second gear when a deviation angle between the bottom phase of the first gear and the bottom phase of the second gear is minimum. the first detection process detects a phase of the first detection tooth among all the teeth of the first gear;
the second detection process detects a phase of one of the second detection teeth among all the teeth of the second gear;
the first phase calculation process calculates a phase of a tooth of the first gear other than the first detection tooth based on a phase of the detected one of the first detection teeth and a tooth pitch angle of the first gear;
The gear machining device according to any one of claims 1 to 3, wherein the second phase calculation process calculates a phase of a tooth of the second gear other than the second detection tooth, based on a phase of the detected one of the second detection teeth and a tooth pitch angle of the second gear. the first detection process detects phases of a plurality of the first detection teeth among all the teeth of the first gear,
the second detection process detects phases of a plurality of the second detection teeth among all the teeth of the second gear;
The first phase calculation process includes:
Calculating a phase of a specific one of the first detection teeth based on the first detection teeth and a tooth pitch angle of the first gear;
calculating a phase of a tooth of the first gear other than the first detection tooth based on a phase of the specific first detection tooth and a tooth pitch angle of the first gear;
The second phase calculation process includes:
Calculating a phase of a specific one of the second detection teeth based on the second detection teeth and a tooth pitch angle of the second gear;
4. The gear machining device according to claim 1, wherein a phase of a tooth of the second gear other than the second detection tooth is calculated based on a phase of a specific second detection tooth and a tooth pitch angle of the second gear. The processing step includes:
Controlling the moving device while synchronously controlling the rotation of the positioned gear cutting tool and the workpiece in order to process the tooth surface of the first gear;
The gear machining device according to any one of claims 1 to 5, wherein the moving device is controlled while synchronously controlling the rotation of the positioned gear cutting tool and the workpiece in order to machine the tooth surface of the second gear. The processing step includes:
When the deviation angle in the reference set is equal to or larger than an allowable range, a correction is made to the tool spindle device and the workpiece spindle device so that the deviation angle after machining is reduced,
7. The gear machining device according to claim 1, wherein, when the deviation angle calculated in the deviation angle calculation process is below an allowable range, machining is performed without performing the correction. The gear cutting tool is a gear skiving cutter having a plurality of tool blades with rake faces on the axial end faces and relief faces on the radial outer faces. The gear cutting device according to any one of claims 1 to 7. A phase detection device for an object having a first gear with an equal tooth pitch angle and a second gear with an equal tooth pitch angle different from the number of teeth of the first gear, the phase detection device determining, as a reference set, the tooth phases of the first gear and the tooth phases of the second gear that minimize deviation angles between the tooth phases of the first gear and the tooth phases of the second gear,
a sensor that detects a radial distance to a peripheral surface of the first gear on the object at a position radially opposed to the first gear on the object while the object is rotating, and detects a radial distance to a peripheral surface of the second gear on the object at a position radially opposed to the second gear on the object ;
a spindle device that rotatably holds the object and includes a rotation angle detector that detects a rotation angle;
a processing device that determines the reference set based on the detection results of the sensor and the detection results of the rotation angle detector of the spindle device;
Equipped with
The processing device includes:
a first detection process for detecting a phase of a first detection tooth, which is a part of all teeth of the first gear, based on the radial distance between the sensor and a peripheral surface of the first gear detected by the sensor and the rotation angle detected by the rotation angle detector of the spindle device;
a second detection process for detecting a phase of a second detection tooth, which is a part of all teeth of the second gear, based on the radial distance between the sensor and a peripheral surface of the first gear detected by the sensor and the rotation angle detected by the rotation angle detector of the spindle device;
executing a first phase calculation process for calculating a phase of a tooth of the first gear other than the first detection tooth based on the detected phase of the first detection tooth and a tooth pitch angle of the first gear stored in advance;
execute a second phase calculation process to calculate a phase of a tooth of the second gear other than the second detection tooth based on the detected phase of the second detection tooth and a tooth pitch angle of the second gear stored in advance;
executing a deviation angle calculation process to calculate deviation angles between the phases of the teeth of the first gear and the phases of the teeth of the second gear, based on the phases of all the teeth of the first gear obtained by the first detection process and the first phase calculation process and the phases of all the teeth of the second gear obtained by the second detection process and the second phase calculation process;
a phase detection device that executes a determination process to determine, as the reference set, the phase of the teeth of the first gear and the phase of the teeth of the second gear that result in the smallest deviation angle.

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