JP7167430B2 - TRUEING DEVICE AND TRUEING METHOD FOR THREADED Grinding wheel - Google Patents

Description

The present invention relates to a truing device and a truing method for a threaded grindstone.

Conventionally, in a gear grinder that processes various gears using a threaded grindstone, the tooth flank of the threaded grindstone is corrected by truing (or dressing) in order to improve processing accuracy (for example, Patent Documents 1 to 3 reference). Truing (dressing) is performed using, for example, a disk-shaped truer. Normally, when performing such truing (dressing), the operator brings the tip of the truer into contact with the tooth surface of the threaded grindstone while the threaded grindstone is stopped, and the controller controls the contact position for truing. (dressing) is stored as the starting point. Then, the control device moves the truer to the memorized starting point and makes it cut in the depth direction (thickness direction) of the tooth surface from the starting point to a predetermined depth set in advance, thereby performing truing (dressing) of the tooth surface. do

JP 2016-78186 A Japanese Patent No. 4099258 Japanese Patent No. 4741544

However, the tooth flank of the threaded grindstone may have waviness (runout) in the circumferential and radial directions. Therefore, when the operator brings the tip of the truer into contact with the tooth flank of the stopped threaded grindstone, the contact portion may be the bottom of the waviness of the tooth flank. In this case, the starting point of truing (dressing) is the bottom, and truing (dressing) is started from the bottom of the tooth surface. For this reason, when the truer is cut by a predetermined amount, there is a possibility that the tooth flank is cut more than necessary in the depth direction, shortening the life of the threaded grindstone. Moreover, it takes too much time for the operator to manually bring the tip of the truer into contact with the tooth surface of the threaded grindstone to detect the starting position.

It is an object of the present invention to provide a truing device for a threaded grinding wheel and a truing method using the truing device, capable of suppressing the amount of truing, obtaining a long-life threaded grinding wheel, and shortening the work time for truing. .

(1. First aspect of truing device)
A truing device for a threaded grindstone according to a first aspect supports a threaded grindstone having a spiral tooth trace formed with a predetermined helix angle on the outer periphery of a cylinder so as to be rotatable about a first axis. An outer peripheral surface of the tooth trace of the threaded grindstone that is rotatably supported around a first rotating shaft and a second axis, relatively moves in the direction of the second axis and in a direction perpendicular to the second axis, and rotates, or a truer for truing a tooth surface; a contact detection unit that outputs a contact detection signal when the truer moves to approach the tooth trace and comes into contact with the outer peripheral surface or the tooth surface; a control device that moves at least one of the threaded grindstones to a desired position and controls rotation to perform the truing.

Further, the control device continuously rotates the threaded grindstone and causes the truer to enter a space in the tooth space between the tooth traces of the threaded grindstone adjacent in the first axial direction. In a state in which the threaded grindstone is continuously rotated at a predetermined rotation speed or higher set based on the relative movement speed of the processing section, the threaded grindstone, and the truer in the first axial direction, a contact processing unit that causes the truer, which has entered the tooth space, to relatively move in at least one of the first axial directions to contact the tooth surface and output the contact detection signal by the contact detection unit; is in contact with the tooth surface and the contact detection signal is outputted; and based on the contact position stored in the contact position storage unit, a start position setting processing unit for setting a truing start position when the truing is started by a truer; and a truing processing unit for executing the truing after moving the truer to the truing start position when the truing is executed. wherein the predetermined rotational speed is a speed at which the truer does not contact the bottom of the undulations on the tooth surface of the threaded grindstone in the treatment by the contact processing section, and contacts other than the bottom. It is the speed that is possible.

In this manner, in the contact processing section, the truer approaches the tooth flank and eventually comes into contact with it while the threaded grindstone is continuously rotated at a predetermined rotational speed or higher. At this time, by setting the rotation speed of the threaded grindstone to a predetermined rotation speed or more, when the truer contacts the tooth surface, the slope nearer the apex of the undulation than the bottom rather than the bottom of the undulation of the tooth surface. can be brought into contact with the truer at any position. After that, the truing processing section starts truing from the position of the tooth flank where the truer comes into contact (truing start position), so that the amount of truing on the tooth flank can be reduced compared to when truing is started from the bottom. As a result, the life of the threaded grindstone is extended. In addition, since the truing start position on the tooth surface of the threaded grindstone is automatically detected by the control of the control device, the time required for the truing work can be shortened.

(2. Second aspect of truing device)
In addition, the truing device for a threaded grinding wheel according to the second aspect rotatably rotates a threaded grinding wheel having a helical tooth trace formed on the outer periphery of a cylinder with a predetermined helix angle around a first axis. The outer periphery of the tooth trace of the threaded grindstone that is rotatably supported around a second axis by a supporting first rotating shaft and relatively moves in the direction of the second axis and in a direction perpendicular to the second axis to rotate. a truer for truing a surface or a tooth surface; a contact detection unit that outputs a contact detection signal when the truer moves to approach the tooth trace and comes into contact with the outer peripheral surface or the tooth surface; and a control device that moves at least one of the threaded grindstones to a desired position and controls rotation to perform the truing.

The control device further comprises a tooth-groove entry processing section for causing the truer to enter a space in the tooth groove between the tooth traces of the threaded grindstones adjacent in the first axial direction, and a predetermined movement of the threaded grindstone. and the truer entered into the space in the tooth space has a predetermined gap exceeding 0 between it and the position of the predetermined phase on the tooth surface, and The contact detector is brought into contact with the contacted portion of the tooth surface at a phase different from the predetermined phase while relatively moving the truer in the first axial direction so that the truer moves in synchronism with the rotation of the tooth surface. to output the contact detection signal, move the truer in the first axial direction, and create a state in which the predetermined gap exceeding 0 exists between the truer and the contacted portion of the tooth surface. is repeatedly performed every time the contact detection signal is output within a predetermined phase range in the tooth trace direction of the tooth surface, and the contact processing unit finally outputs the contact detection signal. A contact position storage unit for storing a contact position, which is the position of the truer at a point in time, and a truing start position for starting the truing by the truer based on the contact position stored in the contact position storage unit. a start position setting processing unit; and a truing processing unit that moves the truer to the truing start position and then executes the truing when the truing is executed , wherein the contacted portion of the tooth surface is the contact portion of the tooth surface. It is a position where the waviness height of the tooth flank is higher than the position of the predetermined phase on the tooth flank .

Thus, in the contact processing section, the threaded grindstone is continuously rotated at a predetermined rotational speed, and a predetermined gap exceeding 0 is formed between the truer, which has entered the space in the tooth space, and the tooth surface. In this state, the truer is brought into contact with the contacted portion of the tooth surface while relatively moving in the direction of the first axis so that the truer moves in synchronism with the rotation of the tooth surface, and a contact detection signal is generated by the contact detection unit. Then, the truer is moved in the direction of the first axis so that the predetermined gap exceeding 0 is formed between the truer and the tooth surface. Then, such processing is repeated every time the contact detection signal is output within a predetermined phase range in the tooth trace direction of the tooth surface, and the highest position of the waviness of the tooth surface within the predetermined phase range is detected. Explore. After that, the truing processing unit sets one of the positions of the tooth surface with which the truer is in contact as the truing start position, and starts truing from the truing start position. The amount of truing on the surface can be reduced. As a result, the life of the threaded grindstone is extended. In addition, since the truing start position on the tooth surface of the threaded grindstone can be automatically detected by the control of the control device, the time required for the truing work can be shortened.

(3. First aspect of truing method)
A first aspect of the truing method is a truing method for a threaded grindstone using the truing apparatus according to the first aspect, wherein the threaded grindstone is continuously rotated while the truer is moved to the first truing device. a tooth space entering step of entering the space in the tooth space between the tooth traces of the threaded grindstones adjacent in the axial direction; In a state in which the threaded grindstone is continuously rotated at a predetermined rotation speed or more set based on the above, the truer, which has entered the tooth groove, is moved relative to the tooth groove in at least one of the first axial directions. contacting the tooth surface, causing the contact detection unit to output the contact detection signal, and storing the contact position, which is the position of the truer at the time when the contact detection signal was output, in the contact position storage unit. a start position setting step of setting a truing start position when starting the truing by the truer based on the contact position stored in the contact position storage unit; and a truing step of performing the truing after moving to the truing start position, wherein the predetermined rotational speed is set so that the truer reaches the bottom of the waviness on the tooth surface of the threaded grindstone in the treatment by the contact processing unit. It is a speed that does not contact the bottom and allows contact with anything other than the bottom . As a result, the same effects as those obtained with the first aspect of the truing device can be obtained.

(4. Second aspect of truing method)
A second aspect of the truing method is a truing method for a threaded grindstone using the truing device according to the second aspect, wherein the truer is adjacent to the threaded grindstone in the first axial direction. a tooth space entering step of entering the space in the tooth space between the tooth traces; The truer is moved along the first axis so that the truer moves synchronously with the rotation of the tooth surface while maintaining the predetermined gap exceeding 0 between the position of the tooth surface and the position of the predetermined phase. While relatively moving in the direction, the truer is brought into contact with the contacted portion of the tooth surface at a phase different from the predetermined phase, the contact detection unit outputs the contact detection signal, and the truer is moved in the first axial direction. The contact detection is carried out within the predetermined phase range in the tooth trace direction of the tooth surface so that the predetermined gap exceeding 0 exists between the truer and the contacted portion of the tooth surface. a contacting step of repeatedly performing each time a signal is output and storing a contact position, which is the position of the truer at the point in time when the contact detection signal was last output, in the contact position storage unit; a start position setting processing step of setting a truing start position when starting the truing by the truer based on the stored contact position; and moving the truer to the truing start position when the truing is executed. and a truing step of performing the truing later , wherein the contacted portion of the tooth flank is a position where the undulation height of the tooth flank is higher than the predetermined phase position of the tooth flank . As a result, the same effects as those obtained with the second aspect of the truing device can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view of the schematic of the gear grinding machine which is embodiment of this invention. 2 is a side view of the gear grinding machine of FIG. 1; FIG. FIG. 2 is a front view showing a state during truing in the gear grinding machine of FIG. 1; 4 is an enlarged view of a state in which the truer 52 and the threaded grindstone are superimposed in FIG. 3. FIG. 1 is a configuration diagram of a truing device according to a first embodiment; FIG. It is a figure explaining an outer diameter detection process. It is a figure explaining a tooth space position detection process. It is a figure explaining a tooth space approach process. It is the first figure explaining a contact processing process. It is the second figure explaining a contact treatment process. FIG. 10 is a diagram showing the movement state of the truer in the contact treatment process by a graph of the axial position and phase of the truer. 1 is a flow chart 1 of an overall truing process; 2 is a flowchart 2 of an outer diameter detection process; 3 is a flowchart 3 of a tooth gap position detection process; 4 is a flowchart 4 of a tooth space entering process, a contact process, a start position setting process, and a truing process. It is a block diagram of the truing apparatus which concerns on 2nd embodiment. It is the first figure explaining the contact process concerning a second embodiment. It is the second figure explaining the contact process concerning a second embodiment. It is the third figure explaining the contact process concerning a second embodiment. 5 is a flow chart 5 of a contact step and the like, which are parts different from the first embodiment in the second embodiment.

<1. First Embodiment>
(1-1. Configuration of gear grinder 10)
An example of the gear grinding machine 10 equipped with the truing device 50 according to the first embodiment of the present invention will be described with reference to the drawings. The gear grinding machine 10 includes a bed 11, a movable table 12, a ball shaft 13, a ball nut 14, a motor 15, a headstock 16, a tailstock 17, a truing device 50, a control device 90, Prepare.

As shown in the front view of FIG. 1, the movable table 12 is placed on the bed 11 so as to be horizontally movable. A ball nut 14 is fixed to the lower surface of the movable table 12 . The ball nut 14 is screwed onto the ball shaft 13 inserted through the bed 11 .

A control device 90 controls rotation of a motor 15 attached to one end of the bed 11 to rotate the ball shaft 13 forward and backward. As a result, the movable table 12 moves back and forth along with the ball nut 14 on the bed 11 in the horizontal direction (X direction) in the figure. A headstock 16 and a tailstock 17 are placed on the movable table 12 so as to face each other and to be movable on the movable table 12 in the horizontal direction in the figure.

As shown in the side view of FIG. 2, a column 23 is erected behind the movable table 12 (to the right in the drawing). A turntable 18 is rotatably supported by a horizontal shaft 44 on the front surface of the column 23 . A grindstone table 19 is supported on the front surface of the turntable 18 . A shaft 20 rotated about an axis by a motor 45 fixed to a column 23 is provided on the rear surface of the turntable 18 in the vertical direction in FIG.

A worm 21 that rotates integrally with the shaft 20 is fixed to the shaft 20 . The worm 21 meshes with a worm wheel 22 provided on the outer circumference of the horizontal shaft 44 . Accordingly, when the motor 45 is operated to rotate the worm 21 forward and backward, the turntable 18 rotates about the horizontal shaft 44 as the center of rotation.

A ball shaft 47 that is rotated by a motor 46 fixed to the bed 11 and a ball nut 48 that is fixed to the column 23 and screwed with the ball shaft 47 are provided below the column 23 . With such a configuration, when the control device 90 operates the motor 46 , the ball shaft 47 rotates, and the column 23 advances and retreats in the front-rear direction (horizontal direction in FIG. 2 ) parallel to the horizontal shaft 44 .

On the turntable 18, a control device 90 controls the rotation of a motor 41 fixed to the turntable 18 to rotate a ball shaft 42 forward and backward. 43 is provided. With such a configuration, when the ball shaft 42 is rotated under the control of the controller 90, the wheelhead 19 moves vertically (in the Y direction).

When grinding is performed by the gear grinding machine 10 having the above configuration, first, as shown in FIG. ) horizontally. Then, the controller 90 controls the motors 15, 41 and 46 to move the threaded grindstone 27 and the workpiece 30 relative to each other so that the threaded grindstone 27 mounted on the spindle 26 of the grindstone table 19 is used. Then, the object 30 to be ground is ground.

At this time, if the object to be ground 30 is a worm gear, the first axis 51a of the threaded grindstone 27 is oriented vertically. Then, the worm gear is ground by rotating the threaded grindstone 27 and the worm gear (object to be ground 30) so as to have the same relationship as the mating gear that meshes with the worm gear. As shown in FIG. 4, the threaded grindstone 27 in this embodiment has a spiral tooth trace 27a formed with a predetermined helix angle γ° on the outer circumference of the cylinder.

In the above description, each motor has an encoder, which detects the absolute positions of the movable table 12, column 23, turntable 18, grindstone base 19, threaded grindstone 27, etc. controlled by each motor. Each detected absolute position and absolute phase (angle) is transmitted to the control device 90 and stored in the storage device 56 in association with each time.

(1-2. Truing device 50)
The truing device 50 will be described mainly based on the schematic diagram shown in FIG. The truing device 50 is a device for truing the outer peripheral surface 27a1 (tooth tip) and the tooth surface 27a2 of the tooth trace 27a of the threaded grindstone 27 (see FIG. 5).

As shown in FIG. 5, the truing device 50 includes a first rotating shaft 51, a truer 52, an AE sensor 53 (corresponding to a contact detection section), a control device 54, and a rotation driving device. Controller 54 is part of controller 90 . The control device 54 also includes a processing device 55 that controls each drive circuit, a storage device 56, a display device, an input device, and the like (not shown).

The storage device 56 stores a grinding program for the object 30 to be ground, a truing program for the threaded grindstone 27, and the like. The storage device 56 is connected to each processing unit, the AE sensor 53, etc., although not shown. Various data are input to the storage device 56 by an input device (not shown). The input device includes a keyboard for inputting data and a display device such as a CRT for displaying data.

The rotary drive device comprises a drive circuit and motors 511 and 57, and rotates the first rotary shaft 51 and the truer 52 about their axes by rotating the motors 511 and 57, respectively. The rotary drive device is controlled by each processing section of the processing device 55 . The motor 511 also has an encoder 512 that detects the absolute angle of the first rotating shaft 51 controlled by the motor 511 . Each detected absolute position and absolute phase (angle) is transmitted to the storage device 56 and stored in the storage device 56 in association with each time.

In this embodiment, the first rotating shaft 51 is the spindle 26 of the wheelhead 19 described above. The first rotating shaft 51 (spindle 26 ) is rotationally driven by a motor 511 fixed to the upper surface of the wheelhead 19 . Further, the first rotating shaft 51 supports the threaded grindstone 27 so as to be rotatable around a first axis 51 a that is the axis of the first rotating shaft 51 . In FIG. 1, the first rotating shaft 51 is arranged in the vertical direction.

However, when the truing device 50 is operated and the tooth surface 27a2 of the threaded grindstone 27 is trued by the truer 52, the motor 45 (see FIG. 2) is operated under the control of the processing device 55, and the worm 21 and Through the worm wheel 22 , the turntable 18 rotates around the horizontal shaft 44 . As a result, the first rotating shaft 51 is arranged with the first axis 51a having an inclination angle γ° with respect to the vertical direction, as shown in FIG.

The truer 52 is rotatably supported on the rear upper surface of the movable table 12 by a vertically elongated support member 521 . Specifically, the truer 52 is rotatably supported by a second rotating shaft 522 that protrudes from the upper end of the support member 521 and is rotatably provided. The second rotating shaft 522 is arranged such that the second axis 522a, which is the axis, is oriented in the vertical direction. A motor 57 incorporated in the support member 521 is connected to the second rotating shaft 522, and the rotation of the motor 57 causes the truer 52 to rotate. The motor 57 is connected to the processing device 55 via a drive circuit and is rotationally controlled by the processing device 55 .

From the above, during truing, the second rotating shaft 522 is inclined relative to the first axis 51a by γ° which is equal to the predetermined twist angle γ° of the tooth trace 27a of the threaded grindstone 27 ( See Figure 3). As a result, the second axis 522a of the second rotating shaft 522 and the tooth trace 27a of the threaded grindstone 27 are substantially perpendicular to each other at the point where the truer 52 and the threaded grindstone 27 come into contact (see FIG. 4). However, not limited to the above aspect, the relative inclination angle of the second axis 522a with respect to the first axis 51a may not be equal to the twist angle γ° of the tooth trace 27a. The relative tilt angle may be arbitrarily set at γ°±α° with the twist angle γ° as the center. Also, it may be set to an arbitrary value regardless of the twist angle γ°.

Also, the truer 52 is a disk-shaped member. The truer 52 is rotatably supported on a second rotating shaft 522 having a second axis 522a so as to rotate in a horizontal plane about the second axis 522a. The rotation axis of the truer 52 and the second axis 522a are arranged coaxially.

As shown in FIG. 4, the disc-shaped truer 52 has a tooth tip 523 with an acute cross-sectional shape, and a contact portion 524 that contacts the tooth surface 27a2 of the threaded grindstone 27 is formed on the upper and lower surfaces. . Fine diamond grains are evenly attached to the entire surface of the tip 523 and the contact portion 524 . When the truer 52 performs truing on the outer peripheral surface 27a1 (top) or the tooth surface 27a2 of the tooth trace 27a of the threaded grindstone 27, the truer 52 moves toward the threaded grindstone 27 in the direction of the second axis 522a and Truing is performed on the tooth surface 27a2 of the threaded grindstone 27 while relatively moving with a component in the direction orthogonal to the second axis 522a.

Actually, in this embodiment, the threaded grindstone 27 moves in the left-right direction (front-rear direction (Z direction)) and the up-down direction (Y direction) in FIG. direction). As a result, the truer 52 and the threaded grindstone 27 move relative to each other on a line parallel to the first axis 51a in the Z direction, and the truer 52 performs desired truing on the tooth surface 27a2 of the threaded grindstone 27. FIG.

As shown in FIG. 1 , the AE sensor 53 (contact detection section) is fixed to a part of the support member 521 of the truer 52 . The AE sensor 53 detects contact when the truer 52 moves relative to the threaded grindstone 27 and contacts the outer peripheral surface 27a1 or the tooth surface 27a2 of the tooth trace 27a of the threaded grindstone 27 . Then, the AE sensor 53 outputs a contact detection signal S1 and transmits it to the processing device 55 (control device 54). Note that the AE sensor 53 may be fixed to the threaded grindstone 27 side.

The AE sensor 53 is a known sensor that detects elastic waves (acoustic emissions (AE)) such as breaking sound waves of the threaded grindstone 27 generated when the truer 52 and the threaded grindstone 27 come into contact with each other. Since it is well known, further detailed description will be omitted.

As described above, the control device 54 includes the processing device 55 and the storage device 56 (contact position storage section 55E). The processing device 55 includes an outer diameter detection processing unit 55A, a tooth space position detection processing unit 55B, a tooth space entry processing unit 55C, a contact processing unit 55D, a start position setting processing unit 55F, and a truing processing unit 55G. And prepare. In the present embodiment, the truing start position on the tooth surface 27a2 of the threaded grindstone 27 at the start of truing is determined mainly by the processes of the tooth space entry processing section 55C, the contact processing section 55D, and the start position setting processing section 55F. is set.

The outer diameter detection processing unit 55A is a processing unit that automatically detects the maximum diameter φDmax of the outer diameter of the outer peripheral surface 27a1 of the threaded grindstone 27 . Although the details will be described later, the outer diameter detection processing unit 55A rotates the threaded grindstone 27 at a predetermined rotational speed around the first axis 51a, and rotates the threaded grindstone 27 in the front-rear direction (Z direction) toward the truer 52. move. Then, the tip 523 or the contact portion 524 of the truer 52 is brought into contact with the outer peripheral surface 27a1 of the threaded grindstone 27 on a line parallel to the first axis 51a and the Z direction, and the maximum diameter φDmax of the outer peripheral surface 27a1 is detected. At this time, the predetermined rotational speed is set based on the speed at which the truer 52 relatively moves in the Z direction toward the outer peripheral surface 27a1. That is, the predetermined rotation speed is a rotation speed that enables the maximum outer diameter portion (including the vicinity) of the outer peripheral surface 27a1 to first contact the truer 52 when the outer peripheral surface 27a1 approaches the truer 52. is set to

The tooth groove position detection processing section 55B is a processing section that roughly detects the position of the tooth groove 27c of the threaded grindstone 27. FIG. The tooth space 27c here means a space between two tooth traces 27a of the threaded grindstone 27 adjacent in the direction of the first axis 51a. Therefore, two tooth surfaces 27a2 (first tooth surface) and 27a2 (second tooth surface) are arranged facing each other on both sides of the tooth groove 27c in the direction of the first axis 51a. 27a3. The first tooth flank 27a2 and the second tooth flank 27a2 will be used in the later description of the operation.

In this embodiment, the tooth trace 27a of the threaded grindstone 27 is assumed to be formed by a single tooth trace. In FIG. 3, it is assumed to be formed by three tooth traces 27aA, 27aB, and 27aC. In order to roughly obtain the position of the tooth space 27c for the threaded grindstone 27 formed in this manner, there is a known method described below. In this method, as shown in FIG. 7 when the threaded grindstone 27 is viewed from the axial direction, the threaded grindstone 27 that is not continuously rotated is rotated at three rotation phases D, E, and F in the rotation direction B. , the truer 52 approach the tooth space 27c from the same reference position. Then, the position of the truer 52 in contact with each phase is stored, and the position of the phase where the contact timing (time until contact) from the reference position is the slowest, that is, the position of the phase where the truer 52 enters the deepest is regarded as the tooth gap. It is something to do.

At this time, in each of the three rotation phases D, E, and F, the angle between the rotation phase D and the rotation phase E in the rotation direction B, and the angle between the rotation phase E and the rotation phase F are the tooth trace is three, each should be at least 40° calculated by 360°/number of threads/3. That is, when the tooth trace is three lines, if the angle between each phase is 40°, the approximate position of the tooth space can be obtained. Further, when the tooth trace is a single line, if the angle between the phases is 120°, the approximate position of the tooth space can be obtained. For example, in FIG. 7, the contact timing of the truer 52 is the slowest in the rotation phase F. Therefore, it is assumed that the center of the tooth space 27c is at the position of the rotational phase F, and the subsequent processing is performed.

It should be noted that the following method may be used when the center of the tooth space 27c is desired to be obtained with higher accuracy, without being limited to the above-described method. That is, at the rotational phase F of the threaded grindstone 27 measured above, the threaded grindstone 27 is brought close to the truer 52 and the truer 52 is caused to enter the tooth groove 27c of the threaded grindstone 27 . After that, the threaded grindstone 27 is rotated in the forward direction about the first axis 51a, and the rotation angle θ1 (not shown) when the truer 52 contacts one tooth surface 27a2 (first tooth surface) is stored. .

Next, the threaded grindstone 27 is rotated in the opposite direction around the first axis 51a, and the rotation angle θ2 (not shown) when the truer 52 contacts the other tooth surface 27a2 (second tooth surface) is stored. . An average value .theta.m (.theta.m=(.theta.1+.theta.2)/2) of the rotation angles .theta.1 and .theta.2 may be obtained as the center position of the groove 27c of the threaded grindstone 27. As a result, the position of the tooth space 27c can be determined with high accuracy. There is no possibility that it will collide with the surface 27a2 and that subsequent processing will not be possible.

The tooth space entry processing unit 55C is a processing unit that relatively causes the truer 52 to enter the space within the tooth space 27c while continuously rotating the threaded grindstone 27 at a rotational speed Vθ1 that is equal to or higher than a predetermined rotational speed. . At this time, the position of the tooth space 27c is based on the position data (rotational phase F) assuming that the tooth space position detection processing unit 55B has the center of the tooth space 27c. In addition, the depth of penetration into the tooth groove 27c in the radial direction is until the tooth tip 523 of the truer 52 reaches the PCD (reference pitch circle diameter) position of the threaded grindstone 27 (see the two-dot chain line in FIG. 8A). . The PCD is obtained based on the maximum diameter φDmax detected by the outer diameter detection processing section 55A. However, this is only one aspect, and the depth of penetration of the truer 52 into the tooth space 27c may be set arbitrarily. Further, since the PCD is well known, detailed description thereof will be omitted.

The contact processor 55D moves the truer 52, which has entered the tooth groove 27c, relative to the tooth groove 27c in at least one of the directions of the first axis 51a while the threaded grindstone 27 is continuously rotated at the rotation speed Vθ1. AE sensor 53 (contact detection section) outputs a contact detection signal S1 (see FIG. 8B). In this embodiment, as shown in FIGS. 8B and 8C, the truer 52 and the threaded grindstone 27 are relatively moved in the Y direction, thereby relatively moving both sides in the direction of the first axis 51a. will be explained.

When determining the rotation speed Vθ1 of the threaded grindstone 27, the reference “predetermined rotation speed” is set based on the speed at which the truer 52 relatively moves toward the tooth surface 27a2. That is, the predetermined rotational speed is the undulation that the tooth surface 27a2 has when the truer 52 relatively approaches the tooth surface 27a2 (see apex a, intermediate position b, and bottom c shown in FIGS. 8B and 8C). It is the rotation speed that enables the vertex a (including the vicinity) of the undulations to first contact the truer 52 and not to contact at least the bottom c of the undulation.

In the above description, in order to move the truer 52 relative to the tooth groove 27c in the direction of the first axis 51a, "relative feed rate Vy of the truer with respect to the threaded grindstone 27/rotational speed Vθ of the threaded grindstone 27" is With respect to the state in which the truer 52 and the tooth space 27c move synchronously, control may be performed to slightly increase or decrease the movement. As a result, as shown in the graph of FIG. 9, the truer 52 moves relative to the tooth space 27c in the direction of the first axis 51a, and eventually comes into contact with the tooth surface 27a2 (see points j and k).

Note that the graph of FIG. 9 is a schematic diagram in which the tooth spaces 27c and the tooth flanks 27a2 are expanded. In the graph of FIG. 9, the horizontal axis represents the phase of the tooth space 27c, and the vertical axis represents the position of the truer 52 in the first axial direction. As indicated by M in FIG. 9, which has a positive inclination, when Vy/V.theta. Also, as shown in the N portion having a negative inclination, when Vy/Vθ is decreased after contact at point j, the truer 52 approaches the tooth flank 27a2 shown below and eventually contacts at point k. A broken line in the graph indicates a state in which the truer 52 and the tooth space 27c move synchronously.

The contact position storage unit 55E stores the rotation of the threaded grindstone 27 when the truer 52 moves relative to the threaded grindstone 27 in the direction of the first axis 51a to contact the tooth surface 27a2 and the contact detection signal S1 is output. A storage unit that stores the phase θ, the position of the threaded grindstone 27 in the first axis 51a direction (Y direction), the position in the front-rear direction (Z direction), etc. as the contact position Po of the truer 52 .

The start position setting processing unit 55F is a processing unit that sets a truing start position P1 when truing is started by the truer 52 based on the contact position Po stored in the contact position storage unit 55E. In other words, the truing start position P1 is a position corresponding to the vertex a (including its vicinity) of the undulations of the tooth surface 27a2.
The truing processing unit 55G is a processing unit that executes truing after moving the truer 52 to the truing start position P1. Details will be given in the description of the operation (method).

(1-3. Truing method)
Next, the truing method will be described mainly based on flowcharts 1 to 4 of FIGS. 10 to 13. FIG. In order to perform truing, first, as shown in FIG. The tooth trace 27a of the threaded grindstone 27 is inclined by a torsion angle γ with respect to a plane (in this embodiment, a plane perpendicular to the plane of the paper). By tilting the first axis 51a of the threaded grindstone 27 in this manner, the tooth trace 27a of the threaded grindstone 27 becomes parallel to the horizontal plane in a line parallel to the first axis 51a and the Z direction.

In this state, the movable table 12 is moved rightward in the X direction in FIG. FIG. 4 shows the positional relationship between the threaded grindstone 27 and the truer 52 at this time as seen from the front. As shown in FIG. 4, the first axis 51a of the threaded grindstone 27 is inclined with respect to the second axis 522a of the truer 52 by the helix angle γ of the tooth trace 27a of the threaded grindstone 27 .

Truing is started in such a state. As shown in a flowchart 1 of FIG. 10, the overall truing process includes an outer diameter detection step S10, a tooth space position detection step S20, a tooth space entry step S30, a contact step S40, and a start position setting step S50. , and a truing step S60.

(1-3-1. Outer Diameter Detection Step S10)
First, the outer diameter detection step S10 processed by the outer diameter detection processing section 55A will be described based on the flowchart 2 of FIG. The outer diameter detection step S10 is a step of automatically detecting the maximum diameter φDmax of the outer diameter of the outer peripheral surface 27a1 of the threaded grindstone 27, as described above. The outer diameter detection step S10 includes steps S101 to S107.

In step S101, the threaded grindstone 27 is rotated around the first axis 51a at a predetermined rotational speed Vθ2. At this time, the predetermined rotation speed Vθ2 is such that when the truer 52 approaches the outer peripheral surface 27a1, the maximum outer diameter portion (including the vicinity thereof) of the outer peripheral surface 27a1 (tooth tip) comes into contact with the truer 52 first. is the rotation speed that enables

In step S102, the column 23, that is, the threaded grindstone 27 is advanced in the direction of the truer 52 (forward in the front-rear direction (Z direction)) at a predetermined speed. That is, the truer 52 moves relative to and approaches the threaded grindstone 27 at a predetermined forward speed (see FIG. 6). At this time, the predetermined advance speed is the speed corresponding to the predetermined rotational speed Vθ2 of the threaded grindstone 27, and is the speed at which the outer peripheral surface 27a1 (tooth tip) first contacts the maximum outer diameter portion (including the vicinity thereof). is. In order to contact the maximum outer diameter portion, the rotation speed Vθ is increased and the forward speed is decreased.

Next, in step S103, it is determined whether or not the truer 52 has come into contact with the maximum outer diameter portion of the outer peripheral surface 27a1 (tooth tip) and the AE sensor 53 has output the contact detection signal S1. When the contact detection signal S1 is output and transmitted to the processing device 55 (control device 54), the process moves to step S104. If the contact detection signal S1 is not output, the processes of steps S102 and S103 are repeatedly executed until the output of the contact detection signal S1 is confirmed in step S103.

In step S<b>104 , the absolute position of the threaded grindstone 27 displayed on the display device (not shown) is input using an input device (not shown) and stored in the storage device 56 . In step S105 (outer diameter detection step S10), the outer peripheral surface 27a1 ( The outer diameter (maximum diameter φDmax) of the tooth tip) is calculated.

In step S106, the threaded grindstone 27 moves (retreats) rightward in FIG. 2 to a position where it is completely separated from the truer 52.
After that, in step S107 (outer diameter detection step S10), the rotation of the threaded grindstone 27 is stopped.

(1-3-2. Tooth space position detection step S20)
Next, the tooth space position detection step S20 processed by the tooth space position detection processing section 55B will be described. The tooth space position detection step S20 is a step of roughly detecting the position of the phase of the tooth space 27c of the threaded grindstone 27 . The contents are as described above. The tooth gap position detection step S20 includes steps S201 to S216.

In step S201, the threaded grindstone 27 is rotated around the first axis 51a and positioned at a position where the rotational phase is D (see FIG. 7).
In step S<b>202 , the threaded grindstone 27 is advanced in the direction of the truer 52 .

In step S203, it is determined whether or not the AE sensor 53 outputs the contact detection signal S1 due to the truer 52 coming into contact with any portion within the tooth space 27c. When the contact detection signal S1 is output and transmitted to the processing device 55 (control device 54), the process moves to step S204. If the contact detection signal S1 is not output, the processes of steps S202 and S203 are repeatedly performed until the output of the contact detection signal S1 is confirmed in step S203.

In step S204, the absolute position Za of the threaded grindstone 27 displayed on the display device (not shown) when the contact detection signal S1 is output is input to the storage device 56 and stored. At this time, the absolute position Za is a value that increases as the moving distance of the threaded grindstone 27 from the reference position increases. That is, the value increases as the truer 52 penetrates deeper into the tooth space 27c. The same applies to absolute positions Zb and Zc described later.
In step S205, the threaded grindstone 27 retreats and moves rearward to separate the truer 52 from the tooth groove 27c.

Next, steps S206 to S210 (tooth groove position detection step S20) are performed. Steps S206 to S210 correspond to steps S201 to S205 in order of arrangement, and perform the same processing. A difference from steps S201 to S205 is that the threaded grindstone 27 is positioned at the rotational phase D in step S201, but the threaded grindstone 27 is positioned at the rotational phase E in step S206. In step S204, the absolute position Za of the threaded grindstone 27 was input and stored in the storage device 56, but in step S209 corresponding to step S204, the absolute position Zb of the threaded grindstone 27 at the rotational phase E was It is input to and stored in the storage device 56 .

Furthermore, next, the processes of steps S211 to S215 are performed. Steps S211 to S215 correspond to (Steps S201 to S205) and (Steps S206 to S210) in order of alignment, respectively, and perform similar processing.

In steps S201 and S206, the threaded grindstone 27 is positioned at the rotational phases D and E, but in step S211, the threaded grindstone 27 is positioned at the rotational phase F. In steps S204 and S209, the absolute positions Za and Zb of the threaded grindstone 27 were input and stored in the storage device 56. However, in step S214 corresponding to steps S204 and S209, the 27 absolute position Zc is input to the storage device 56 and stored.

In step S<b>216 , the largest value among the absolute positions Za, Zb, and Zc stored in the storage device 56 is selected and stored in the storage device 56 . In this embodiment, the absolute position Zc at the rotational phase F is selected. That is, it is assumed that the tooth space 27c has a tooth bottom 27a3 or a tooth surface 27a2 near the tooth bottom 27a3 at the position of the rotational phase F.

(1-3-3. Tooth space entering step S30)
Next, the tooth space entering step S30, the contact step S40, the start position setting step S50 and the truing step S60 will be described based on the flowchart 4 of FIG. The tooth space entering step S30 processed by the tooth space entering processing section 55C is, as described above, a step of moving the truer 52 relative to the threaded grindstone 27 and allowing the truer 52 to enter the space within the tooth space 27c. be. More specifically, this is a step in which the tooth addendum 523 of the truer 52 enters the tooth groove 27 c so as to be positioned on the pitch circle of the pitch circle diameter (PCD) R1 of the threaded grindstone 27 . The tooth space entering step S30 includes steps S301 and S302.

In step S301 (tooth space entering step S30), the threaded grindstone 27 is continuously rotated at a rotation speed Vθ1. Then, the threaded grindstone 27 is vertically moved at a moving speed Vy1 and advanced at a predetermined moving speed Vz1. This causes the truer 52 to enter the space in the tooth spaces 27c between the tooth traces 27a of the threaded grindstones 27 adjacent in the direction of the first axis 51a (see FIG. 8A). At this time, the position of the tooth space 27c into which the truer 52 enters is the position of the rotational phase F where the center of the tooth space 27c is determined by the tooth space position detection processing section 55B.

In step S302 (tooth space entering step S30), the forward (to the left in FIG. 2) movement speed Vz1 of the threaded grindstone 27 is set to 0 at the position where the tip 523 of the truer 52 reaches the PCD. As a result, the tip 523 of the truer 52 is positioned on the PCD within the tooth groove 27c.

(1-3-4. Contact step S40)
In the contact step S40 processed by the contact processing unit 55D, the tip of the threaded grindstone 27 is caused to enter the tooth groove 27c in a state in which the threaded grindstone 27 is continuously rotated at a rotation speed Vθ1 that is a rotation speed equal to or higher than a predetermined rotation speed. In this step, the truer 52 is moved relative to the tooth groove 27c in at least one of the directions of the first axis 51a to come into contact with the tooth surface 27a2, and the AE sensor 53 (contact detection section) outputs a contact detection signal. The contacting step S40 comprises steps S401 to S407.

In step S401, the rotation speed Vθ1 of the threaded grindstone 27 is reduced to a rotation speed Vθ2 (Vθ2<Vθ1) smaller than the rotation speed Vθ1 while the vertical movement speed Vy1 of the threaded grindstone 27 is kept constant. As a result, as described above, the truer 52 moves relative to the tooth groove 27c in the direction of the first axis 51a, and eventually comes into contact with the tooth surface 27a2 (see point j in FIG. 9). At this time, under the conditions of the rotational speed Vθ1 and the moving speed Vy1 of the threaded grindstone 27, the truer 52 is synchronized with the tooth groove 27c in the direction of the first axis 51a when it first enters the tooth groove 27c. shall be

That is, when the truer 52 first enters the tooth space 27c, the truer 52 does not contact the tooth surface 27a2 (first tooth surface) and the tooth surface 27a2 (second tooth surface) facing each other in the tooth space 27c. Relative movement is performed in the direction of the axis 51a. By reducing the rotation speed Vθ1 to a rotation speed Vθ2 (Vθ2<Vθ1) smaller than the rotation speed Vθ1, the truer 52 in the tooth groove 27c moves toward one side in the direction of the first axis 51a with respect to the tooth groove 27c. to move relative to each other. However, it is not limited to this mode, and it is not necessary to be synchronized from the beginning of entering the tooth space 27c.

In step S402 (contact step S40), it is determined whether the truer 52 has come into contact with the tooth surface 27a2 (first tooth surface) and the AE sensor 53 has output the contact detection signal S1. When the contact detection signal S1 is output and transmitted to the processing device 55 (control device 54), the process moves to step S402. If the contact detection signal S1 is not output, the processes of steps S401 and S402 are repeatedly executed until the output of the contact detection signal S1 is confirmed in step S402.

In step S403 (contact step S40), the contact position Po, which is the position of the threaded grindstone 27 at the time when the truer 52 comes into contact with one of the tooth surfaces 27a2 and the contact detection signal S1 is output, is stored in the contact position storage unit 55E. stored in device 56). As the contact position Po, there are two contact positions in the tooth height direction and the contact position in the tooth thickness direction.

In step S404 (contact step S40), the rotational speed Vθ2 of the threaded grindstone 27 is increased to a rotational speed Vθ3 (Vθ2<Vθ1<Vθ3) greater than the rotational speed Vθ1 while the vertical movement speed Vy1 is kept constant. do. As a result, the truer 52 in the tooth space 27c starts to move relative to the tooth space 27c toward the other side in the direction of the first axis 51a (see FIG. 8C). Then, the truer 52 eventually comes into contact with the tooth surface 27a2 on the other side (see point k in FIG. 9).

In step S405 (contact step S40), it is determined whether the truer 52 has come into contact with the tooth surface 27a2 (second tooth surface) and the AE sensor 53 has output the contact detection signal S1. When the contact detection signal S1 is output and transmitted to the processing device 55 (control device 54), the process moves to step S406. If the contact detection signal S1 is not output, the processes of steps S404 and S405 are repeatedly executed until the output of the contact detection signal S1 is confirmed in step S405.

In step S406 (contact step S40), the contact position Po, which is the position of the threaded grindstone 27 at the time when the truer 52 contacts the other tooth surface 27a2 and the contact detection signal S1 is output, is stored in the contact position storage unit 55E. do. As the contact position Po, there are two contact positions in the tooth height direction and the contact position in the tooth thickness direction.

In step S407 (contact step S40), the rotational speed Vθ3 of the threaded grindstone 27 is again set to be smaller than Vθ3, and the truer 52 is relatively separated from the tooth surface 27a2 (second tooth surface). The grindstone 27 is retracted to separate the truer 52 from the tooth groove 27c.

(1-3-5. Start position setting step S50)
In the start position setting step S50 (start position setting processing unit 55F), theoretical cross-sectional shape data of the tooth surface 27a2 (represented by a plurality of pairs of tooth height direction positions and tooth thickness direction positions) ), and based on the contact position Po of one tooth surface 27a2 and the contact position Po of the other tooth surface 27a2 stored in the contact position storage unit 55E, the truing start positions when truing is started by the truer 52 are set to two opposing positions. It is set for two tooth flanks 27a2, 27a2 (first and second tooth flanks). When the contact position in the tooth thickness direction of the contact position Po is on the tooth groove side compared to the position in the tooth thickness direction of the theoretical cross-sectional shape data, the theoretical cross-sectional shape data of the tooth flank 27a2 is the threaded grindstone 27, and conversely, when it is on the side opposite to the tooth space, it is set on the inner diameter side of the threaded grindstone 27.

(1-3-6. Truing step S60)
Then, in the truing step S60, the threaded grindstone 27 and the truer 52 are relatively moved to the truing start position with respect to the two opposing tooth flanks 27a2, 27a2 (first and second tooth flanks), and then truing is sequentially performed. . Truing is repeated by changing the position in the tooth height direction. When truing is performed by changing the position in the tooth height direction, theoretical cross-sectional shape data of the tooth surface 27a2 set in the radial direction according to the contact position Po is used. At this time, at the truing start position, the position of the tooth surface 27a2 against which the tooth tip 523 of the truer 52 abuts is any position different from the bottom portion of the undulation of the tooth surface 27a2. For this reason, compared to the case where truing is started from the bottom of the undulation on the tooth surface 27a2, the removal amount by truing on the tooth surface 27a2 can be suppressed. In addition, in this embodiment, the truing start position for truing the tooth surface 27a2 of the threaded grindstone 27 is automatically set under the control of the control device 54, so the time required for truing work can be shortened.

In the above embodiment, in the contact step S40 to the truing step S60, the truer 52 is applied to both the tooth flank 27a2 (first tooth flank) and the opposing tooth flank 27a2 (second tooth flank). It was assumed that the invention was applied and truing was performed. However, it is not limited to this aspect. In the contact step S40 to the truing step S60, the invention may be applied to at least one of the tooth flank 27a2 (first tooth flank) and the opposing tooth flank 27a2 (second tooth flank). . At this time, for the truing of the other tooth surface 27a2, the depth level of the waviness of the tooth surface 27a2 is predicted based on the data of the one tooth surface 27a2 to which the invention is applied, and the predicted apex position of the waviness is trued. It may be set as a starting position and truing may be performed. At this time, theoretical cross-sectional shape data of the tooth surface 27a2 (represented by a plurality of pairs of positions in the tooth height direction and tooth thickness direction) is used.

<2. Second Embodiment>
(2-1. Configuration of gear grinding machine 110)
Next, an example of the gear grinding machine 110 equipped with the truing device 150 (see FIGS. 1 to 3) according to the second embodiment will be described with reference to the drawings. However, the gear grinding machine 110 differs from the gear grinding machine 10 of the first embodiment only in the control device 154 of the truing device 150 . Therefore, only different parts will be described in detail, and descriptions of similar parts will be omitted.

As shown in FIG. 14, the control device 154 of the truing device 150 includes a processing device 155 and a storage device 156 (contact position storage section 155E). The processing device 155 includes an outer diameter detection processing unit 55A, a tooth space position detection processing unit 55B, a tooth space entry processing unit 55C, a contact processing unit 155D, a start position setting processing unit 155F, and a truing processing unit 55G. And prepare. In this embodiment, the truing start position on the tooth surface 27a2 of the threaded grindstone 27 is set by the processes of the tooth space entry processing section 55C, the contact processing section 155D, and the start position setting processing section 155F. do.

In the processing device 155, the contact processing section 155D continuously rotates the threaded grindstone 27 at a predetermined rotational speed, and also rotates the truer 52, which has entered the space within the tooth groove 27c, and the tooth surface 27a2. A gap d1 (to be described later) is provided. In this state, the truer 52 is relatively moved in the direction of the first axis 51a so that the truer 52 moves in synchronism with the rotation of the tooth surface 27a2, and is brought into contact with the contacted portion of the tooth surface 27a2. A detection unit) outputs a contact detection signal S1 to move the truer 52 in the direction of the first axis 51a so that the truer 52 has a predetermined gap d1 between the tooth surface 27a2 and the tooth surface 27a2. is repeated each time the contact detection signal S1 is output within a predetermined phase range in the tooth trace direction.

Specifically, the contact processing section 155D includes a first contact processing section D1, a second contact processing section D2, a third contact processing section D3, and a fourth contact processing section D4. As shown in FIG. 15A, the first contact processing portion D1 moves the truer 52, which has entered the space in the tooth groove 27c, relative to the tooth groove 27c in at least one of the directions of the first axis 51a to form the tooth surface 27a2. AE sensor 53 (contact detection section) outputs a contact detection signal S1.

After the first contact processing section D1 contacts the truer 52 with the contacted section Q1, the second contact processing section D2 moves the truer 52 so that a predetermined gap d1 exceeding 0 exists between the truer 52 and the contacted section Q1. A process of relatively moving in the direction of the first axis 51a away from the contacted portion Q1 is performed (see FIG. 15B).

The third contact processing portion D3 orients the truer 52 in the direction of the first axis 51a so that the truer 52 moves in synchronization with the rotation of the tooth surface 27a2 with a predetermined gap d1 between itself and the contacted portion Q1. (see FIG. 15C), and when there is a contacted portion Q2 (not shown) thicker than the contacted portion Q1 within a predetermined phase range in the tooth trace 27a direction of the tooth surface 27a2, the tooth thickness The touched portion Q2 is brought into contact with the AE sensor 53 (contact detection portion) to output the contact detection signal S1.

The fourth contact processing portion D4 performs a predetermined process in the second contact processing portion D2 and the processing in the third contact processing portion D3 when there is a contacted portion Q2 having a tooth thickness in the third contact processing portion D3. is a processing unit that is repeatedly performed within the phase range of . From the following description, the flowchart of FIG. 16 will be used. The outer diameter detecting step S10, the tooth space position detecting step S20, and the tooth space entering step S30 are the same as the steps S301 and S302 in the flowcharts 2, 3, and 4 of FIGS. Description is omitted.

(2-2. Truing method)
The action of the truing method from the state where the truer 52 has entered the tooth space 27c will be described based on the flowchart 5. FIG. In step S141A (corresponding to step S401 in flowchart 4) in the first contact step S141 (contact step S140) processed by the first contact processing section D1, the rotation speed Vθ1 of the threaded grindstone 27 is set to a rotation speed smaller than the rotation speed Vθ1. Decelerate to Vθ2 (Vθ2<Vθ1).

In step S141B (corresponding to step S402 in Flowchart 4) in the first contact step S141 (contact step S140), the truer 52 contacts the contacted portion Q1 of the tooth surface 27a2 (first tooth surface) (see FIG. 15A). , whether or not the AE sensor 53 outputs the contact detection signal S1 is determined. When the contact detection signal S1 is output and transmitted to the processing device 155 (control device 154), the process moves to step S141C (corresponding to step S403 in flowchart 4). If the contact detection signal S1 is not output, the processes of steps S141A and S141B are repeatedly executed until the output of the contact detection signal S1 is confirmed in step S141B (corresponding to step S402 in flowchart 4).

In step S141C (corresponding to step S403 in flowchart 4) in the first contact step S141 (contact step S140), the contact position Po, which is the position of the threaded grindstone 27 at the time when the contact detection signal S1 is output, is stored in the contact position storage unit. 155E.

In the second contact step S142 (contact step S140) processed by the second contact processing section D2, the rotation speed Vθ2 of the threaded grindstone 27 is changed while the vertical movement speed Vy1 of the threaded grindstone 27 is kept constant. The speed is increased to a rotational speed V.theta.3 that is higher than the rotational speed V.theta.1. As a result, the truer 52 in the tooth space 27c is relatively moved toward the other side in the direction of the first axis 51a with respect to the tooth space 27c until a gap d1 exists between it and the tooth surface 27a2 (see FIG. 15B). . Although the predetermined gap d1 can be set arbitrarily, it is preferably about several microns.

In step S143A in the third contacting step S143 (contacting step S140) processed by the third contact processing section D3, the threaded grindstone 27 is rotated with a predetermined gap d1 between the truer 52 and the tooth surface 27a2. The rotational speed V.theta.3 is reduced again. The rotation speed to be reduced at this time is a rotation speed at which the truer 52 and the tooth groove 27c (that is, the tooth surface 27a2) can move synchronously.

In step S143B in the third contact step S143 (contact step S140), the truer 52 contacts the tooth surface 27a2 (first tooth surface) within a predetermined phase range in the direction of the tooth trace 27a of the tooth surface 27a2, and the AE sensor is activated. 53 outputs the contact detection signal S1. When the contact detection signal S1 is output and transmitted to the processing device 155 (control device 154), the process moves to step S143C, and each time, the contact position Po, which is the position of the truer 52 at the time when the contact detection signal S1 is output. is stored in the contact position storage unit 155E. As the contact position Po, there are two contact positions in the tooth height direction and the contact position in the tooth thickness direction.

In step S143D, it is determined whether the phase of truer 52 is within a predetermined phase range. If it is within the predetermined phase range, the process returns to step S142, and the process is repeated until it is determined in step S143D that it is not within the predetermined phase range. If it is determined in step S143D that the phase is not within the predetermined phase range, in step S143E, the last stored contact position Po among the contact positions Po that have been stored in the contact position storage unit 155E is selected in step S143E. .

At this time, the processing steps from step S142 to step S143D are referred to as a fourth contact step S144 (contact step S140). In step S143D, if there is no truer 52 within the predetermined phase range, the process moves to start position setting step S150. In addition, the above process is performed on two opposing tooth flanks 27a2, 27a2 (first and second tooth flanks).

In the start position setting step S150 (start position setting processing unit 155F), theoretical cross-sectional shape data of the tooth surface 27a2 (represented by a plurality of pairs of positions in the tooth height direction and tooth thickness direction), contact Based on the contact position Po of one tooth flank 27a2 and the contact position Po of the other tooth flank 27a2 lastly stored in the position storage unit 155E, the truing start position when truing is started by the truer 52 is set to two opposing positions. It is set for the tooth flanks 27a2, 27a2 (first and second tooth flanks). When the contact position Po in the tooth thickness direction is closer to the tooth groove than the position in the tooth thickness direction of the theoretical cross-sectional shape data of the tooth surface 27a2, the theoretical cross-sectional shape data of the tooth surface 27a2 is , is set on the outer diameter side of the threaded grindstone 27, and conversely, when it is on the side opposite to the tooth space, the theoretical shape data of the tooth surface 27a2 is set on the inner diameter side of the threaded grindstone 27.

Then, in the truing step S160, the threaded grindstone 27 and the truer 52 are relatively moved to the truing start positions with respect to the two opposing tooth flanks 27a2, 27a2 (first and second tooth flanks), and then truing is sequentially performed. . Truing is repeated by changing the position in the tooth height direction. When truing is performed by changing the position in the tooth height direction, theoretical cross-sectional shape data of the tooth surface 27a2 set in the radial direction according to the contact position Po is used. As a result, the same effects as those of the above embodiment can be obtained.

According to the above embodiment, in the contact steps S40 and S140, the truer 52 is brought into contact with both of the two opposing tooth flanks 27a2 and 27a2 (first and second tooth flanks). is not limited. In the contact steps S40 and S140, the truer 52 is brought into contact with only one tooth flank 27a2 to determine the shape thereof, and the shape of the opposing tooth flank 27a2 is determined based on the shape of the tooth flank 27a2 determined by the contact. can be obtained by calculation. At this time, theoretical cross-sectional shape data of the tooth surface 27a2 (represented by a plurality of pairs of positions in the tooth height direction and tooth thickness direction) is used.

(3. Effect of Embodiment)
In the threaded grindstone truing device 50 according to the above-described embodiment, the control device 54 continuously rotates the threaded grindstone 27 at a predetermined rotation speed or more, and moves the truer 52 to the adjacent threaded grindstone 27 in the direction of the first axis 51a. In a state in which the tooth groove entering processing unit 55C enters into the space in the tooth groove 27c between the tooth traces 27a, and the threaded grindstone 27 is continuously rotated at a predetermined rotation speed or more, the tooth groove 27c is moved to the tooth groove 27c. a contact processing section 55D which relatively moves the truer 52 introduced into the inside in at least one of the directions of the first axis 51a to bring it into contact with the tooth surface and causes the AE sensor 53 (contact detection section) to output a contact detection signal S1; 52 contacts the tooth surface 27a2 and the contact detection signal S1 is output. Based on this, a start position setting processing unit 55F for setting the truing start position when truing is started by the truer 52, and a truing processing unit 55G for executing truing after moving the truer 52 to the truing start position when truing is executed. And prepare.

In this way, in the contact processing section 55D, the truer 52 approaches the tooth surface 27a2 and eventually comes into contact with the threaded grindstone 27, which is continuously rotated at a predetermined rotational speed or higher. At this time, by setting the rotation speed Vθ of the threaded grindstone 27 to a predetermined rotation speed or more, when the truer 52 contacts the tooth surface 27a2, the waviness of the tooth surface 27a2 is not the bottom portion, but the waviness is generated from the bottom portion. The truer 52 can be brought into contact with any position on the slope near the top of the . After that, the truing processing unit 55G starts truing from the position (truing start position) of the tooth surface 27a2 with which the truer 52 is in contact, thereby reducing the amount of truing on the tooth surface 27a2 compared to when truing is started from the bottom. can do This prolongs the life of the threaded grindstone 27 . In addition, since the truing start position on the tooth surface 27a2 of the threaded grindstone 27 is automatically detected under the control of the control device 54, the time required for truing work can be shortened.

Further, according to the above embodiment, the contact processing portion 55D moves the truer 52, which has entered the space in the tooth space 27c, relative to the tooth space 27c in one direction of the first axis 51a so that the tooth surface 27a2 is moved. After contacting the first tooth flank, the truer 52 is relatively moved in the other direction of the first axis 51a and brought into contact with the second tooth flank, which is the tooth flank facing the first tooth flank within the tooth groove 27c. Since the truing start position is determined for both of the tooth flanks 27a2 facing each other in this manner, a higher effect can be expected than when the truing start position is determined for only one of the tooth flanks 27a2.

In the threaded grindstone truing device 150 according to the above-described embodiment, the control device 154 moves the truer 52 into the space in the tooth spaces 27c between the tooth traces 27a of the threaded grindstones 27 adjacent in the direction of the first axis 51a. The tooth space entering processing portion 55C and the threaded grindstone 27 are continuously rotated at a predetermined rotational speed, and the truer 52 that has entered the space in the tooth space 27c is separated from the tooth surface 27a2 by a predetermined value exceeding 0. With the gap d1, the truer 52 is relatively moved in the direction of the first axis 51a so that the truer 52 moves synchronously with the rotation of the tooth surface 27a2, and is brought into contact with the contacted portion Q1 of the tooth surface 27a2. A contact detection signal S1 is output by the AE sensor 53 (contact detection section), and the truer 52 is moved in the direction of the first axis 51a to form a predetermined gap d1 exceeding 0 between the truer 52 and the tooth surface 27a2. The contact processing unit 155D repeats the process to set the state to the tooth trace 27a direction each time the contact detection signal S1 is output within a predetermined phase range in the tooth trace 27a direction of the tooth surface 27a2. When the truer 52 starts truing based on the contact position storage unit 155E that stores the contact position Po, which is the position of the truer 52 at the time when the signal S1 is output, and the contact position Po stored in the contact position storage unit 155E. and a truing processing unit 55G for moving the truer 52 to the truing start position and then executing the truing.

In this manner, a higher contacted portion Q is searched for on the tooth surface 27a2, and the last detected contact position Po is set as the truing start position. detectable. As a result, the amount of truing on the tooth surface 27a2 can be further reduced compared to when truing is started from the bottom of the undulation. As a result, the life of the threaded grindstone 27 is further extended.

Further, the contact processing section 155D of the control device 154 provided in the truing device 150 according to the above embodiment moves the truer 52, which has entered the space in the tooth space 27c, toward at least one side of the tooth space 27c in the direction of the first axis 51a. The truer 52 is caused by the first contact processing section D1 that is relatively moved to make contact with the contact portion Q1 of the tooth surface 27a2 and causes the AE sensor 53 (contact detection section) to output the contact detection signal S1, and the first contact processing section D1. a second contact processing part D2 that relatively moves the truer 52 away from the contacted part Q1 after contact with the contacted part Q1 so that a predetermined gap d1 exceeding 0 exists between the truer 52 and the contacted part Q1; The truer 52 is relatively moved in the direction of the first axis 51a so as to move in synchronism with the rotation of the tooth surface 27a2 with a predetermined gap d1 between the truer 52 and the contacted portion Q1. If there is a contact portion Q2 having a greater tooth thickness than the contact portion Q1 within a predetermined phase range in the direction of the streak 27a, the contact portion Q2 having a tooth thickness is brought into contact with the AE sensor 53 (contact detection portion). In the third contact processing unit D3 that outputs the contact detection signal S1, and in the third contact processing unit D3, when there is a contacted portion Q2 having a tooth thickness, the processing in the second contact processing unit D2 and the third contact processing unit and a fourth contact processing section D4 that repeatedly performs the processing in D3 and the processing in D3 within a predetermined phase range. In this way, after contacting the contacted portion Q1, the higher contacted portion Q2 is searched for, so that at least the contacted portion Q1 can be obtained efficiently.

In the above-described embodiment, the contact detection section includes an AE sensor, which detects contact between the truer 52 and the threaded grindstone 27 and outputs a contact detection signal S1. As a result, the contact between the truer 52 and the threaded grindstone 27 can be detected at low cost and with high accuracy.

In addition, the truing method of the truing device 50 according to the above-described embodiment continuously rotates the threaded grindstone 27 at a predetermined rotation speed or more, and rotates the truer 52 to the tooth trace 27a of the threaded grindstone 27 adjacent in the direction of the first axis 51a. A tooth space entering step S30 for entering the space in the tooth space 27c between The truer 52 is relatively moved in at least one of the directions of the first axis 51a and is brought into contact with the tooth surface 27a2, and the AE sensor 53 (contact detection section) outputs the contact detection signal S1, and at the time when the contact detection signal S1 is output. A contact step S40 of storing the contact position Po, which is the position of the truer, in the contact position storage unit 55E, and a truing start position when the truer 52 starts truing based on the contact position Po stored in the contact position storage unit 55E. and a truing step S60 for moving the truer 52 to the truing start position and then executing the truing. As a result, truing with the same effect as that obtained by truing by the truing device 50 can be performed.

Further, the truing method of the truing device 150 according to the above-described embodiment is a tooth space entering step of entering the space in the tooth space 27c between the tooth traces 27a of the threaded grindstones 27 adjacent in the direction of the first axis 51a. S30 and a state in which the threaded grindstone 27 is continuously rotated at a predetermined rotational speed and the truer 52 entered into the space in the tooth groove 27c has a predetermined gap d1 exceeding 0 between it and the tooth surface 27a2. Then, while relatively moving the truer 52 in the direction of the first axis 51a so that the truer moves in synchronism with the rotation of the tooth surface 27a2, the truer 52 is brought into contact with the contact portion Q1 of the tooth surface 27a2, thereby causing the AE sensor 53 (contact detection unit ) to output a contact detection signal S1 and move the truer 52 in the direction of the first axis 51a to provide a predetermined gap d1 exceeding 0 between the truer 52 and the tooth surface 27a2. within a predetermined phase range in the direction of the tooth trace 27a, each time the contact detection signal S1 is output, and the contact position Po, which is the position of the truer 52 at the time when the contact detection signal S1 was last output, is detected. a contact step S40 for storing in the position storage unit 155E; a start position setting step S150 for setting a truing start position when truing is started by the truer 52 based on the contact position Po stored in the contact position storage unit 155E; and a truing step S160 for moving the truer 52 to the truing start position and then executing truing in the execution of . As a result, truing with the same effect as that obtained by truing by the truing device 150 can be performed.

In the present embodiment, the AE sensor 53 is used as contact detection means, but the present invention is not limited to this. The contact of the truer 52 with the tooth surface 27a2 may be detected by detecting the contact of the truer 52 with the tooth surface 27a2.

10, 110; gear grinding machine, 27; threaded grindstone, 27a; tooth trace, 27a1; outer peripheral surface, 27a2; 50, 150; truing device, 51; first rotating shaft (spindle 26), 51a; first axis, 52; truer, 53; AE sensor (contact detection unit), 54, 154; Tooth space position detection processing unit, 55C; Tooth space entry processing unit, 55D, 155D; Contact processing unit, 55E, 155E; Contact position storage unit, 55F, 155F; Start position setting processing unit, 55G; Processing unit 56, 156; storage device 522; second rotation axis 522a; second axis line d1; gap P1; truing start position Po;

Claims (7)

a first rotary shaft that supports a threaded grindstone having a spiral tooth trace formed with a predetermined helix angle on the outer circumference of the cylinder so as to be rotatable around a first axis;
Truing the outer peripheral surface of the tooth trace or the tooth surface of the threaded grinding wheel that is rotatably supported around the second axis, relatively moves in the direction of the second axis and in a direction orthogonal to the second axis, and rotates. and Tulua, who performs
a contact detection unit that outputs a contact detection signal when the truer moves to approach the tooth trace and comes into contact with the outer peripheral surface or the tooth surface;
a control device that moves at least one of the truer and the threaded grindstone to a desired position and controls rotation to perform the truing;
A threaded grindstone truing device comprising
The control device is
a tooth groove entry processing unit that continuously rotates the threaded grindstone and causes the truer to enter a space in the tooth groove between the tooth traces of the threaded grindstone adjacent in the first axial direction;
In a state in which the threaded grindstone is continuously rotated at a predetermined rotation speed or more set based on the relative movement speed of the threaded grindstone and the truer in the first axial direction, a contact processing unit that relatively moves the truer that has entered into at least one of the first axial directions to contact the tooth surface and causes the contact detection unit to output the contact detection signal;
a contact position storage unit for storing a contact position, which is the position of the truer when the truer contacts the tooth surface and the contact detection signal is output;
a start position setting processing unit that sets a truing start position when starting the truing by the truer based on the contact position stored in the contact position storage unit;
a truing processing unit that moves the truer to the truing start position and then executes the truing when executing the truing;
with
The predetermined rotation speed is a speed at which the truer does not come into contact with the bottom of the undulations on the tooth surface of the threaded grindstone in the treatment by the contact processing section, but can come into contact with anything other than the bottom. A truing device for a threaded grindstone. The contact processing unit is
After the truer, which has entered the space in the tooth space, is moved relative to the tooth space in one direction of the first axial line and brought into contact with the first tooth surface,
2. The screw shape according to claim 1, wherein said truer is relatively moved in the other direction of said first axial line and brought into contact with said second tooth surface which is said tooth surface facing said first tooth surface within said tooth space. Grinding wheel truing device. a first rotary shaft that supports a threaded grindstone having a spiral tooth trace formed with a predetermined helix angle on the outer circumference of the cylinder so as to be rotatable around a first axis;
Truing the outer peripheral surface of the tooth trace or the tooth surface of the threaded grinding wheel that is rotatably supported around the second axis, relatively moves in the direction of the second axis and in a direction orthogonal to the second axis, and rotates. and Tulua, who performs
a contact detection unit that outputs a contact detection signal when the truer moves to approach the tooth trace and comes into contact with the outer peripheral surface or the tooth surface;
a control device that moves at least one of the truer and the threaded grindstone to a desired position and controls rotation to perform the truing;
A threaded grindstone truing device comprising
The control device is
a tooth groove entry processing section for causing the truer to enter a space in the tooth groove between the tooth traces of the threaded grindstones adjacent in the first axial direction;
A state in which the threaded grindstone is continuously rotated at a predetermined rotational speed, and the truer, which has entered the space in the tooth space, has a predetermined gap exceeding 0 between it and a predetermined phase position of the tooth surface. After that, while relatively moving the truer in the first axial direction so that the truer moves in synchronization with the rotation of the tooth surface, the contacted portion of the tooth surface at a phase different from the predetermined phase The contact detection portion is caused to output the contact detection signal, and the truer is moved in the first axial direction to form the predetermined gap exceeding 0 between the truer and the contacted portion of the tooth surface. a contact processing unit that repeats the process of creating the state of having the contact each time the contact detection signal is output within a predetermined phase range in the tooth trace direction of the tooth surface;
a contact position storage unit for storing a contact position, which is the position of the truer at the time when the contact detection signal was last output, in the contact processing unit;
a start position setting processing unit that sets a truing start position when starting the truing by the truer based on the contact position stored in the contact position storage unit;
a truing processing unit that moves the truer to the truing start position and then executes the truing when executing the truing;
with
A truing device for a threaded grindstone, wherein the contacted portion of the tooth surface is located at a position where the waviness height of the tooth surface is higher than the position of the predetermined phase of the tooth surface. The contact processing unit is
The truer, which has entered the space in the tooth space, is moved relative to the tooth space in at least one of the first axial directions to come into contact with the contacted portion of the tooth surface, and the contact is detected by the contact detection portion. a first contact processing unit that outputs a detection signal;
A direction in which the truer is separated from the contacted portion by the first contact processing portion so that after the truer contacts the contacted portion, the predetermined gap exceeding 0 exists between the truer and the contacted portion. A second contact processing unit that relatively moves to
The truer is relatively moved in the first axial direction so as to move in synchronism with the rotation of the tooth surface while maintaining the predetermined gap between the truer and the contacted portion, and In the predetermined phase range in the tooth trace direction, if there is a contact portion having a tooth thickness greater than that of the contact portion, the contact detection portion is caused to contact the contact portion having the tooth thickness, and the contact detection signal is generated by the contact detection portion. a third contact processing unit that outputs
In the third contact processing portion, when there is a contacted portion having the tooth thickness, the processing in the second contact processing portion and the processing in the third contact processing portion are repeated within the predetermined phase range. A fourth contact processing unit to perform,
The threaded grindstone truing device according to claim 3, comprising: The screw according to any one of claims 1 to 4, wherein the contact detection unit includes an AE sensor, and the AE sensor detects contact between the truer and the threaded grindstone and outputs the contact detection signal. A truing device for shaped grinding wheels. A truing method for a threaded grindstone using the truing device according to claim 1,
a tooth space entering step of continuously rotating the threaded grindstone and allowing the truer to enter the space in the tooth space between the tooth traces of the threaded grindstones adjacent in the first axial direction;
In a state in which the threaded grindstone is continuously rotated at a predetermined rotation speed or more set based on the relative movement speed of the threaded grindstone and the truer in the first axial direction, The truer is caused to move relatively in at least one of the first axial directions to come into contact with the tooth surface, and the contact detection unit outputs the contact detection signal, and at the time when the contact detection signal is output a contacting step of storing the contact position, which is the position of the truer, in the contact position storage unit;
a start position setting step of setting the truing start position when starting the truing by the truer based on the contact position stored in the contact position storage unit;
a truing step of moving the truer to the truing start position and then performing the truing when performing the truing;
with
The predetermined rotation speed is a speed at which the truer does not come into contact with the bottom of the undulations on the tooth surface of the threaded grindstone in the treatment by the contact processing section, but can come into contact with anything other than the bottom. A truing method for a threaded grindstone. A truing method for a threaded grindstone using the truing device according to claim 3,
a tooth space entering step of causing the truer to enter the space in the tooth space between the tooth traces of the threaded grindstones adjacent in the first axial direction;
The threaded grindstone is continuously rotated at the predetermined rotational speed, and the truer, which has entered the space in the tooth space, has the predetermined gap exceeding 0 between it and the position of the predetermined phase on the tooth surface. In this state, the truer is relatively moved in the first axial direction so that the truer moves in synchronization with the rotation of the tooth flank, while the tooth flank is contacted at a phase different from the predetermined phase. contact with the contact detection portion to output the contact detection signal, move the truer in the first axial direction, and set the predetermined value exceeding 0 between the truer and the contacted portion of the tooth surface. The process of creating a state with a gap is repeatedly performed each time the contact detection signal is output within the predetermined phase range in the tooth trace direction of the tooth surface, and the contact detection signal is output last. a contacting step of storing the contact position, which is the position of the truer at the time, in the contact position storage unit;
a start position setting step of setting the truing start position when starting the truing by the truer based on the contact position stored in the contact position storage unit;
a truing step of moving the truer to the truing start position and then performing the truing when performing the truing;
with
A truing method for a threaded grindstone, wherein the contacted portion of the tooth surface is located at a position where the waviness height of the tooth surface is higher than the predetermined phase position of the tooth surface.

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