JPH09183017A - Automatic gear meshing device for gear grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the position of the both gear faces of a gear part without grinding them by providing a servo error detecting means to detect a servo error by giving a positional offset instruction in both forward and reverse directions under the condition in which a positional loop gain is changed over to a lower value. SOLUTION: An arithmetic circuit 41 corrects an analog voltage for a pulse from a pulse generating circuit 40 so that a servo error (detected by the calculation of a difference between an instruction position of the rotating angle of a spindle 16 input from a numerical control device 30 and a detected value input from an encoder 18a) becomes zero. Also it outputs it after correction according to an offset instruction on the rotating angle of the spindle 16 input from the numerical control device 30. This positional offset instruction offsets a gear W in forward or reverse rotating direction by a prescribed minute amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear grinding apparatus using a screw-shaped grindstone, and relates to an automatic tooth-matching device for automatically performing tooth-matching between the screw-shaped grindstone and a gear prior to grinding.

[0002]

2. Description of the Related Art In a gear grinding machine of this type, it is necessary to carry out a highly accurate tooth engagement between a screw-shaped grindstone and a gear prior to grinding. There is a problem that uneven grinding, which is unground or incomplete grinding, occurs, and the load of the grindstone becomes excessive, so that the life of the grindstone is shortened. As an automatic tooth aligning device for solving such a problem, for example, there is a technique disclosed in Japanese Patent Publication No. 62-38089. This is because the gear is manually engaged with the screw-shaped grindstone with the electromagnetic clutch provided in the rotary drive path that rotates the main shaft that grips the gear via the clamp jig released, and then the screw-shaped grindstone is rotated at low speed. After performing the initial phase alignment based on the output from the work sensor that detects the tooth portion and the pulse from the pulse generator provided on the grindstone shaft, the grindstone is temporarily retracted, and the electromagnetic clutch is engaged to shift the gear and The screw-shaped grindstone is rotationally driven, the phase shift between the gear and the screw-shaped grindstone is corrected based on the data obtained in the initial phase adjustment, and the grindstone is advanced to perform grinding.

Further, the position of each tooth of the gear rotating with the main shaft is detected by a proximity sensor arranged in the radial direction or the axial direction, and the gears and the thread grindstone are aligned with each other in the rotating state of the main shaft. There is also.

[0004]

However, in the technique disclosed in Japanese Patent Publication No. 62-38089, the thread portion of the threaded grindstone is surely equally secured to the tooth flanks on both sides of the tooth portion of the gear in the initial phase alignment state. Since contact is not guaranteed, it is not always possible to achieve sufficient tooth engagement between the threaded wheel and the gear prior to grinding. Further, even in the technique of detecting the position of each tooth portion by the proximity sensor, the detection error is, for example, about several tens of microns on the tooth surface, and thus sufficient matching accuracy cannot be obtained. An object of the present invention is to solve each of the problems described above, and to make it possible to perform tooth engagement between a screw-shaped grindstone and a gear prior to grinding with high precision automatically and in a short time. .

[0005]

DISCLOSURE OF THE INVENTION The present invention is directed to a gear side servo drive device for rotating a main shaft that connects gears and rotates integrally with the gear, and a grindstone for rotationally driving a grindstone shaft provided with a screw-shaped grindstone. Side servo drive device and the position in the rotational direction of the spindle and the grindstone shaft so that the inclined grinding surface of the thread portion of the threaded grindstone grinds the tooth surface of the gear tooth portion by giving a command to both servo drive devices. The present invention relates to a gear grinding device provided with a control device for controlling a main shaft and a grindstone shaft in a traverse direction parallel to the main shaft and in a cutting direction in which rotation axes of both shafts approach each other. Pre-engagement means for engaging the grinding wheel with a pre-engagement position in which the teeth and the thread are engaged with each other with a gap that does not contact each other, and position loop gain of at least one servo system of both servo drive devices. Research And a gain adjustment means for switching the significantly lower value than the higher value suitable for. In the state where the pre-engagement means sets the pre-engagement position and the position loop gain is switched to a low value, the position offset command means causes at least one of the servo drive devices to move the grinding surface of the thread portion and the tooth surface of the tooth portion. A position offset command is given in both the forward and reverse rotation directions such that the distance between them gradually decreases. Since the position loop gain has been switched to a low value, the former does not grind the latter even if the threaded surface of the thread and the tooth surface of the tooth contact each other, and the servo error detection means uses a low position loop gain. The servo error that is the difference between the command value given the position offset command by the position offset command means and the detected value that is the actual position of the position of the spindle or the grindstone shaft corresponding to the servo drive device switched to It detects in both rotation directions. The meshing position calculating means calculates the optimum meshing position based on the servo errors in both the forward and reverse directions detected in this way, and the meshing position correcting means calculates the meshing position based on the optimum meshing position. Make a correction.

It is preferable that the gain adjusting means of the present invention selectively switches the position loop gain of the servo system of the gear side servo drive device between a high value suitable for grinding and a value significantly lower than that. .

According to the present invention, the initial tooth aligning means for detecting the tooth portion of the gear by the proximity sensor to calculate the initial tooth aligning position at which the thread portion of the thread-like grindstone approximately coincides with the intermediate position of the tooth portion of the gear. It is preferable that the pre-meshing means further performs relative movement in the traverse direction and the cutting direction at the initial meshing position to bring the gear and the screw-shaped grindstone to the pre-meshing position.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. As shown in FIG. 1, an X-axis slide table 11 guided and supported on a bed 10 of a gear grinding device so as to be movable in the horizontal X direction (a direction perpendicular to the paper surface) is fed by the first drive motor 13 in the X direction. The Z-axis slide table 12, which is provided and guided and supported on the X-axis slide table 11 so as to be movable in the horizontal Z direction orthogonal to the X direction, is fed by the second drive motor 14 in the Z direction. On the Z-axis slide table 12, a headstock 15 supporting a main shaft 16 and a tailstock 17 are coaxially provided so as to face each other in the Z direction, and one end of a gear W having shafts formed on both sides is not shown. It is coaxially gripped by the main shaft 16 via the chuck and the other end is rotatably supported by the tailstock 17. The spindle 16 is rotationally driven by a spindle rotation driving motor 18 provided on the spindle stock 15, and the gear W is the spindle 1.
6 and 6 are integrally rotated. Each motor 13,1
Reference numerals 4 and 18 respectively include encoders 13a, 14a and 18a for detecting the position of the driven table or shaft.

Further, in the column 20 which integrally stands up from the bed 10, an X-direction axis A orthogonal to the rotation axis of the spindle 16
A Y-axis slide table 22 is guided and supported by a swivel base 21 which is rotatably supported around the Y-axis so as to be movable in a Y direction orthogonal to the axis A, and is fed by a third drive motor 23. . The whetstone base 25 fixed on the Y-axis slide table 22 is provided with a whetstone shaft 26 having a rotation axis parallel to the Y direction and coaxially fixing a threaded grindstone G at the tip thereof. It is driven to rotate by the grindstone shaft rotation driving motor 28. The thread portion Ga having a rack-shaped cross-section formed on the threaded grindstone G has inclined grinding surfaces Gb and Gc for grinding the tooth surfaces Wb and Wc of the tooth portion Wa of the gear W.
(See FIGS. 5 and 8). The swivel base 21 is rotationally driven around the axis A by a drive motor (not shown), so that the tangential direction of the portion of the helical screw thread Ga that contacts the tooth portion Wa coincides with the tooth trace direction of the gear W. It is turned and stopped and locked. Each motor 23, 28
Are provided with encoders 23a and 28a for detecting the position of the driven table or shaft, respectively.

As shown in FIG. 1, the numerical control device 30 has
Central processing unit (CP that controls and manages the entire gear grinding device
U) 31, a memory 32, and an interface I / F for exchanging data with the outside. The CPU 31
A feed position command is given to the first and second drive circuits 35 and 36 via the interface I / F to drive the first and second drive motors 13 and 14, whereby the X-axis and Z-axis slide tables 11, Feed 12 and encoder 1
3a and 14a detect the feed positions of the slide tables 11 and 12 via the rotation angles of the drive motors 13 and 14, and the detected values are sent to the CPU 31 via the interface.
Is input to

Further, the CPU 31 has an interface I /
A rotation angle position command is given to the spindle and grindstone shaft drive circuits 37 and 38 via F to drive the spindle and grindstone shaft rotation drive motor 1.
8 and 28 are driven, whereby the main shaft 16 and the grindstone shaft 26 are driven.
The encoders 18a and 28a detect the rotation angle positions of the spindle 16 and the grindstone shaft 26 via the rotation angles of the drive motors 18 and 28, and the detected values are input to the CPU 31 via the interface. It Although illustration is omitted, the third drive motor 23 is similarly driven by the CPU 31 via a drive circuit to drive the Y-axis slide table 2
2 is fed, and the detected value of the feed position detected by the encoder 23a is input to the CPU 31.

The CPU 31 has an interface I / F.
Although not shown in the drawing, the input / output device 33 is connected via a linear proximity sensor S of the eddy current type or the like, which is arranged in the radial direction with respect to the tooth portion Wa of the rotating gear W.
(See FIG. 5) are connected via an interface. The CPU 31 controls each component based on the input from the input / output device 33 and the detectors such as the proximity sensor S and each encoder to perform a series of operations described later. A control program for performing the above, a grinding process program for the gear W, various data, and the like are stored.

The spindle drive circuit 37, as shown in FIG.
Pulse generation circuit 40, arithmetic circuit 41, servo controller 42, gain controller 43, and servo amplifier 44
It is composed of The pulse generation circuit 40 generates a pulse according to the rotation angle position command value input from the numerical control device 30 every moment. The arithmetic circuit 41 is a two-phase type PLL.
(Phase Locked Loop) is used, and an analog voltage corresponding to the pulse from the pulse generation circuit 40 is input from the servo error (command value input from the numerical control device 30 regarding the rotation angle position of the spindle 16 and the encoder 18a). Detected by calculating the difference between the detected values to be zero, and the spindle 1 input from the numerical control device 30.
It is corrected and output according to the offset command of the rotational angle position of No. 6. This position offset command is applied to the gear W
Is offset by a predetermined minute amount (positional offset amount) in the forward or reverse rotation direction. Although the two-phase PLL is used as the arithmetic circuit 41 in the above, a general servo error arithmetic circuit such as a pulse counter may be used.

The output voltage from the arithmetic circuit 41 is converted into a current by a servo amplifier 44 via a servo controller 42 and a gain controller 43, and this current is given to a spindle rotation drive motor 18 to rotate the spindle 16. The servo controller 42 is an arithmetic circuit that performs, for example, proportional, differential, and integral arithmetic operations on the output voltage from the arithmetic circuit 41, and the gain controller 43 is an amplifier circuit that increases or decreases the output voltage from the servo controller 42, and its gain is By the gain command from the numerical control device 30, a two-stage of a high value (corresponding to large servo rigidity) suitable for grinding the tooth surfaces Wb and Wc of the gear W and a value (corresponding to small servo rigidity) significantly lower than that. Can be selectively switched to. The gain can be set to any value. The servo error detected by the arithmetic circuit 41 is the numerical control device 3
It is also input to 0.

The structure of the grindstone shaft drive circuit 38 is similar to that of the main shaft drive circuit 37, except that there is no gain controller 43 and there is no position offset command or gain command from the numerical controller 30. The first and second drive circuits 35 and 36 have substantially the same configuration as the grindstone shaft drive circuit 38.

In the relationship between the present embodiment and each claim, the spindle drive circuit 37, the spindle rotation drive motor 18 and the encoder 18a constitute a gear side servo drive device, the grindstone spindle drive circuit 38, the grindstone spindle rotation drive motor 28. And encoder 28
a is a whetstone side servo drive device, both drive circuits 35 and 36,
Both drive motors 13 and 14, both encoders 13a and 14
a, a part of the numerical control device 30 is a pre-meshing device, a part of the gain controller 43 and the numerical control device 30 is a gain adjusting device, a part of the numerical control device 30 is a position offset commanding device, the encoder 18a and a calculation. Part of the circuit 41 is servo error detection means, part of the numerical control device 30 is meshing position calculation means, and part of the spindle drive circuit 37, the spindle rotation drive motor 18, the encoder 18a, and the numerical control device 30 are meshed. The position correction means includes a proximity sensor S, a spindle drive circuit 37, a spindle rotation drive motor 18, and an encoder 18a.
And a part of the numerical control device 30 respectively constitutes the initial tooth matching means.

Next, the operation of this embodiment configured as described above will be described with reference to the flowcharts shown in FIGS. 3 and 7 and the explanatory diagrams shown in FIGS. 4 to 6 and 8. Numerical examples are for a spur gear with a module of 5 mm and 18 teeth.

First, as shown in step 101 of FIG. 3, the gear W is attached to the main shaft 16 and the operation button of the input / output device 33 is pressed.
And the grindstone shaft rotation driving motor 28 are operated in synchronization, so that the main shaft 16 and the grindstone shaft 26 are rotated at a predetermined rotational speed such that the grinding surface Gb of the threaded grindstone G can grind the tooth surfaces Wb and Wc of the gear W. Rotational driving is performed at a ratio, first, the initial tooth matching in step 102 is performed, and then step 10 which is the main part of the present invention
After the final tooth matching of No. 3 is performed, the gear W is ground by the screw-shaped grindstone G in step 104. The operations of steps 102 to 104 are continuously and automatically performed in the state where the main shaft 16 and the grindstone shaft 26 are rotationally driven in conjunction with each other as described above. The gear W supported on the Z-axis slide table 12 which is reciprocally driven by the second drive motor 14 is movable in a traverse direction (Z direction) parallel to its rotation axis, as shown in FIG. At the position indicated by the alternate long and short dash line WA which is different from the threaded grindstone G in the traverse direction, the initial tooth matching in step 102 is performed.

As shown in FIG. 5, this initial tooth engagement is performed using a linear proximity sensor S of the eddy current type or the like, which is arranged in the radial direction with respect to the tooth portion Wa of the gear W. The tooth portion Wa of the gear W rotationally driven by the spindle rotation driving motor 18 alternately passes in front of the proximity sensor S, and the proximity sensor S has a spindle rotation angle within a range of about one tooth centered on the tooth bottom. With respect to the position, an output signal voltage is generated in which the central portion as shown in FIG. The CPU 31 detects the spindle rotation angle positions of the two points a1 and a2 at which this output signal voltage intersects a predetermined threshold voltage Va near the center of the left and right inclined portions, and the midpoint thereof is the tooth root center position θb. To detect as. The CPU 31 detects the tooth bottom center position θb of the gear W, the previously known positional relationship between the wheel spindle rotation angle position, and the thread portion Ga of the threaded grindstone G on the basis of the positional relationship between the screw grindstone G of the threaded grindstone G. The thread portion Ga coincides with the detected tooth bottom center position θb of the gear W (the thread portion Ga is the tooth portion Wa.
Of the gear wheel W with respect to the threaded grindstone G, such that the rotational angle position of the main shaft 16 is rotationally driven in conjunction with the grindstone shaft 26. Initial meshing is performed by offsetting in a predetermined rotation direction so that the meshing position is reached. This is the same as the technique described in the prior art, in which the position of each tooth portion of the gear that rotates with the main shaft is detected by the proximity sensor to perform the tooth matching between the gear and the threaded grindstone. The error of the initial tooth contact position is about several tens of microns on the tooth surface.
The proximity sensor S may be arranged in the axial direction with respect to the tooth portion Wa of the gear W.

After the initial tooth matching is performed, the final tooth matching shown in the flowchart of FIG. 7 is performed. The gear W is shown in FIG.
At a position WA shown by the alternate long and short dash line that is different from the threaded grindstone G in the traverse direction as shown in FIG. 1, and the main shaft 16 and the grindstone shaft 26 are driven to rotate in cooperation with each other, first, the CPU 31 of the numerical control device 30 In step 201, the first drive motor 13 is operated to advance the main shaft 16 in the cutting direction in which the rotation axis of the main shaft 16 approaches the rotation axis of the grindstone shaft 26. At this time, when viewed from the traverse direction, the thread grindstone G
Of the tooth W of the gear W, the slanted grinding surfaces Gb and Gc on both sides of the thread Ga are the tooth flanks of the tooth Wa. Wb, W
It is set to a predetermined position so as not to contact with c. Subsequently, in step 202, the second drive motor 14 is operated to traverse the gear W from the position indicated by the alternate long and short dash line WA in FIG. 4 to the position indicated by the solid line where the gear W meshes with the threaded grindstone G by a predetermined amount and stop. To do. As a result, the gear W and the thread-shaped grindstone G mesh with each other with a clearance to the extent that their respective tooth portions Wa and thread portions Ga do not contact each other, as shown by the solid lines in FIGS. 8 (a) and 8 (b). The pre-engagement position is reached. Then CPU
In step 203, 31 is instructed to the gain controller 43 to change the position loop gain of the servo system of the gear side servo drive device from a normal high value suitable for grinding the tooth surfaces Wb and Wc of the gear W (for example, 8000 s ⁻¹ ). It is lowered to a value much lower than that (for example, a value of 1/128 of the normal value).

FIG. 8A is an explanatory diagram in the case of detecting the servo error in the positive direction by giving the position offset command in the positive direction shown in steps 204 to 206, and the pre-engagement position immediately after the end of step 203. Then, the clearance angle along the pitch line WL of the gear W between the one ground surface Gb of the thread portion Ga and the tooth surface Wb of the tooth portion Wa opposite thereto is Δθ _p1 . GL indicates the pitch line of the thread-shaped grindstone G.

The CPU 31 gives a position offset command in the positive direction in step 204, thereby offsetting the gear W in the positive rotation direction (clockwise direction in FIG. 8) by a predetermined minute amount (position offset amount), and then in step 205. Servo error (with respect to the rotational angle position of the main shaft 16
The difference between the command value input to the spindle drive circuit 37 and the detection value input from the encoder 18a is detected from 0, and in step 206, this servo error is compared with a predetermined set value. Here, the gap angle Δθ _p1 along the pitch line WL is decreased by a predetermined position offset amount (for example, about 10 μm) due to the offset in step 204. When it is determined that the servo error is smaller than the set value, the CPU 31
Returns the control operation to step 204, and from step 204 to
Repeat step 206. This repetition is performed without a movement in the traverse direction by sequentially giving a predetermined position offset command until it is determined that the servo error is larger than the set value at the position of the solid line where the gear W meshes with the threaded grindstone G. .

If the accumulated value of the position offset amount increases due to this repetition and the value Δθ _c1 becomes larger than the initial clearance angle Δθ _p1 , the commanded position of the tooth surface Wb is the chain double-dashed line Wb2 of FIG. 8 (a). However, since the position loop gain of the servo system of the gear side servo drive device has been lowered to a low value, the position of the one-dot chain line Wb1 contacting the grinding surface Gb advances from the position of the one-dot chain line Wb2 to the tooth side. The surface Wb is not ground, and the gear W is rotated by the threaded grindstone G in this contact state. In this state, the servo error detected in step 205 is the pitch line W between the command position indicated by the alternate long and two short dashes line Wb2 in FIG. 8A and the actual position indicated by the alternate long and short dash line Wb1.
This is the angle conversion value Δθ _e1 of the distance along L, and if it is determined in step 206 that this servo error Δθ _e1 is larger than the set value, the CPU 31 advances the control operation to step 207, and this servo error Δθ in the positive direction. _e1 memory 32
Is stored in a predetermined area. The detection of the servo error in step 205 is performed while the gear W and the threaded grindstone G are rotating as in the case of grinding. Therefore, if there is an eccentricity error, a pitch error, a tooth profile error, etc., for each tooth portion Wa. Will have different values. Therefore, the servo error in step 205 uses their average value.

Subsequently, the CPU 31 causes the gear W and the screw-shaped grindstone G.
After returning to the pre-engagement position immediately after the end of step 202 (while keeping the position loop gain of step 203 lowered), the negative direction servo error Δθ _e2 is detected in steps 208 to 211 in the memory 32. Stored in a predetermined area of. Details thereof are the same as steps 204 to 207 except that a position offset command in the negative direction is given in step 207, and therefore detailed description will be omitted. Note that FIG. 8 is a schematic explanatory view, and the tooth surfaces Wb, W in the pre-engagement position immediately after the end of step 202, that is, in the state where the final tooth engagement is not substantially started.
The clearance angles Δθ _p1 and Δθ _p2 between c and the ground surfaces Gb and Gc are considerably larger than the detected servo errors Δθ _e1 and Δθ _e2 .

At the following step 212, the CPU 31 calculates the clearance angles Δθ _p1 and Δθ _p2 between the tooth surfaces Wb and Wc and the grinding surfaces Gb and Gc at the pre-engagement position by the following equation 1.

[0026]

## EQU1 ## Δθ _p1 = Δθ _c1 −Δθ _e1 Δθ _p2 = Δθ _c2 −Δθ _e2 Next, in step 213, the CPU 31 starts from the pre-engagement position to the grinding surfaces Gb, Gc and the tooth surfaces Wb, Wc on both sides of the thread ridge Ga. The position offset amount Δθm up to the optimum meshing position where the gaps are the same is calculated by the following equation 2.

[0027]

## EQU2 ## Δθm = (Δθ _p1 −Δθ _p2 ) / 2 However, the sign of Δθm is the same as the direction of the position offset command described above.

Next, in step 214, the CPU 31 gives a position offset command corresponding to this position offset amount Δθm to the gear side servo drive device to offset the gear W in the rotational direction, and is shown by a broken line Wbm in FIG. 8C. like,
The gaps between the tooth surfaces Wb and Wc of the gear W and the grinding surfaces Gb and Gc on both sides of the threaded grindstone G are set to be the same. Then, in step 215, the position loop gain of the servo system of the gear side servo drive device is raised to a normal high value suitable for grinding the tooth surfaces Wb and Wc of the gear W, and in step 216, the gear W is not meshed with the thread grindstone G. A predetermined amount of traversing is performed up to the position of the one-dot chain line WA in FIG. 4, and the final tooth matching shown in the flowchart in FIG. 7 is completed. Since the resolution of the rotational direction position detection of the gear W in the case of this final tooth matching is about 0.25 μm on each tooth surface Wb, Wc, the error of the tooth matching in the final tooth matching is smaller than that in the case of initial tooth matching. Is also much smaller. Note that the step 215 of raising the position loop gain to a high value may be performed after step 212 and before step 104 of FIG.

After the final tooth matching shown in the flow chart of step 4 is completed, the CPU 31 proceeds to step 104 of the flow chart of FIG.
14 is operated to reciprocally traverse the gear W from the position of the one-dot chain line WA to the position of the two-dot chain line WB in FIG. 3, and the gear W is cut to a predetermined position in a predetermined sequence by the threaded grindstone G. By grinding the gear W, both tooth surfaces Wb and Wc are always ground uniformly.

In the above embodiment, the position loop gain of the servo system of the gear side servo drive unit is lowered to detect the servo error based on the rotational angular positions of the tooth surfaces Wb and Wc of the gear W,
The rotation angle position of the gear W is corrected so that the optimum meshing position calculated by this is obtained. However, in order to obtain the optimum meshing position, instead of the rotation angle position of the gear W, a threaded grindstone G is used. May be corrected, or both rotation angle positions may be corrected. Further, according to the present invention, the position loop gain of the servo system of the whetstone side servo drive device is lowered to reduce the grinding surface Gb of the threaded grindstone Gb,
It is also possible to detect the servo error of the position of Gc and correct the rotational angular position of the threaded grinding wheel G, the gear W, or both of them so that the optimum meshing position calculated by this is obtained.

In the above embodiment, the initial tooth engagement is automatically performed by the eddy current type linear proximity sensor S, but it may be automatically performed by other means.
It may be done manually. In the above embodiment, the position loop gain is switched to a low value at the position where the gear and the screw-shaped grindstone mesh with each other. However, the position loop gain may be switched in a state where they do not mesh with each other due to a discrepancy in the traverse direction. According to this, it is possible to prevent damage at the time of meshing due to an erroneous command of the cut amount.

[0032]

According to the present invention described above, since the servo error is detected by applying the position offset command in both the forward and reverse directions in the state where the position loop gain is switched to a low value, both tooth surfaces of the tooth portion are detected. Each position can be accurately detected without grinding. The optimum meshing position is calculated based on the positions of both tooth flanks that are accurately detected in this way, and the meshing position is corrected. Can be achieved with. Moreover, both tooth flanks are detected by giving a position offset command in both forward and reverse directions at the position where the gear and the threaded grindstone mesh without moving in the traverse direction. It is possible to correct the wrong position.

Since the position loop gain suitable for grinding is higher in the servo system of the gear side servo drive device, it is easier to implement the present invention by switching it to a lower value.

Further, the tooth portion of the rotating gear is detected by the proximity sensor to determine the initial meshing position between the threaded grindstone and the gear, and a cut is made at this initial meshing position to detect the servo error. In this case, since the initial tooth matching and the subsequent correction of the meshing position due to the servo error can be continuously performed, the processing time can be shortened as a whole.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an embodiment of an automatic tooth aligning device in a gear grinding device according to the present invention.

FIG. 2 is a diagram showing a configuration of a gear side servo drive device of the embodiment shown in FIG.

3 is a flowchart of the overall operation of the embodiment shown in FIG.

FIG. 4 is a diagram showing a traverse state of the embodiment shown in FIG. 1.

5 is a diagram showing a relationship between a proximity sensor used for initial meshing and a gear of the embodiment shown in FIG.

6 is a diagram showing an example of an output signal of the proximity sensor of FIG.

FIG. 7 is a flowchart of final tooth matching of the embodiment shown in FIG.

8 is an explanatory diagram of final tooth matching of the embodiment shown in FIG. 1. FIG.

[Explanation of symbols]

16 ... Spindle, 26 ... Grindstone axis, 30 ... Control device (numerical control device), G ... Threaded grindstone, Ga ... Thread portion, Ga, Gb
... Grinding surface, S ... Proximity sensor, W ... Gear, Wa ... Teeth, W
b, Wc ... Tooth surface.

Front page continuation (72) Inventor Wang Lei Aoba, Aoba-ku, Aoba-ku, Miyagi Prefecture, Aoba Tohoku University (72) Inventor Kei Teshigara, Aoba-ku, Sendai-shi, Miyagi Aoba, Aoba, Tohoku University (72) Inventor, Yuji Kato Aoba, Aoba-ku, Sendai-shi, Miyagi Aoba, Aoba, Tohoku University (72) Hisashi Nakamura 1-1, Asahi-cho, Kariya-shi, Aichi Toyota-Koki Co., Ltd. (72) Masaru Yamanaka, 1-chome, Asahi-cho, Kariya-shi, Aichi No. 1 in Toyota Koki Co., Ltd.

Claims (3)

[Claims] 1. A gear-side servo drive device that rotates a main shaft that connects gears and rotates integrally with the gear, a grindstone-side servo drive device that rotationally drives a grindstone shaft provided with a screw-shaped grindstone, and both of the above. A control device that gives a command to a servo drive device to control the positions of the spindle and the grindstone shaft in the rotational direction so that the inclined grinding surface of the thread portion of the threaded grindstone grinds the tooth surface of the tooth portion of the gear. In the gear grinding device comprising, the main shaft and the grindstone shaft are moved relative to each other in the traverse direction parallel to the main shaft and the cutting direction in which the rotation axes of the both shafts approach each other, and the gear and the screw-shaped grindstone respectively. Suitable for grinding the pre-engagement means for the pre-engagement position in which the tooth part and the screw thread part are engaged with each other with a gap so as not to contact each other, and the position loop gain of at least one of the servo systems of the both servo drive devices. Gain adjusting means for switching from a high value to a value significantly lower than that, and to at least one of the servo drive devices in the state where the pre-engagement position is set and the position loop gain is switched to the low value. Position offset command means for giving a position offset command in both forward and reverse rotation directions such that the distance between the ground surface of the thread portion and the tooth surface of the tooth portion gradually decreases, and the position loop gain is switched to the low value. A servo error which is a difference between a command value given a position offset command by the position offset command means and a detected value which is an actual position of the position of the spindle or the grindstone shaft corresponding to the servo drive device Servo error detection means,
Based on the meshing position calculating means for calculating the optimum meshing position based on the servo errors in both the forward and reverse directions detected by the servo error detecting means, and the optimum meshing position calculated by the meshing position calculating means. An automatic tooth-matching device in a gear grinding device, characterized by comprising a meshing position correcting means for correcting a meshing position. 2. The gain adjusting means selectively switches the position loop gain of the servo system of the gear side servo drive device between a high value suitable for grinding and a value significantly lower than it. An automatic gear matching device in the gear grinding device according to 1. 3. An initial tooth aligning means for detecting the tooth portion of the gear by a proximity sensor to calculate an initial tooth aligning position at which the screw thread portion of the threaded grindstone approximately coincides with an intermediate position of the tooth portion of the gear. The pre-engagement means further performs relative movement in the traverse direction and the cutting direction at the initial meshing position to bring the gear and the screw-shaped grindstone to the pre-engagement position. An automatic gear matching device in the gear grinding device according to claim 2.