JPH078453B2 - Synchronous operation controller for gear grinding machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronous operation control device for a gear grinding machine, and more particularly to a cutting tool and a work rotary drive system that are biased by a tool rotary drive system. When synchronously rotating the workpiece to be urged, the mechanical precision error contained in the rotary drive system is electrically corrected to improve the processing precision of the workpiece with a simple structure. The present invention relates to a synchronous operation control device for a gear grinding machine, which enables improvement.

[Prior Art] For example, there is used a device for grinding a large number of teeth carved on a gear by engaging a work, that is, a gear with a grindstone having a spiral line formed on its peripheral surface. In this case, unless the synchronous operation is achieved between the grindstone and the gear, the grinding action of the grindstone is not uniformly applied to each tooth of the gear, and the desired gear cannot be obtained. Therefore, in the conventional gear grinding device, a large number of switching gears are mounted on the work side and these gears are appropriately switched to synchronize with the rotation of the grinding wheel side, or a pulse generator is used as a rotation drive source on the grinding wheel side. A method has been adopted in which a work motor is rotated based on a pulse generated in proportion to the amount of rotation and synchronized with the grindstone side (JP-A-58-59728).

[Problems to be Solved by the Invention] However, the former synchronous operation control device for a gear grinding machine requires a large number of highly accurate switching gears, and therefore,
The apparatus itself becomes large and expensive, and it takes a long time to switch the gears, which greatly reduces the operating rate of the entire machine. On the other hand, the latter synchronous operation control device for gear grinding machines is small and can be manufactured at low cost, but many gears are interposed from the work motor for rotating the work to the work itself. Due to the eccentricity and pitch error of these gears that make up the gear and the eccentricity of the gear itself, even if the work motor rotates accurately based on the synchronization signal, an error occurs in the rotation of the work and highly accurate synchronization. It was difficult to drive.

Of course, in order to improve the accuracy of synchronous operation of the grindstone and the work, it is not possible to improve the accuracy of each gear of the gear train from the rotary drive source to the work and to adjust the points of insufficient accuracy when assembling the gear train. Although it is possible to some extent, there are various inconveniences, such as an improvement in gear precision leads to an increase in manufacturing cost, and adjustment during assembly requires a lot of time and labor.

Therefore, an object of the present invention is to engage a cutting tool urged by a tool rotation drive system with a workpiece to be urged by a work rotation drive system to process the workpiece when the workpiece is processed. Another object of the present invention is to provide a synchronous operation control device for a gear grinding machine configured to electrically correct mechanical precision error included in a rotary drive system of a workpiece and then perform synchronous operation of both rotary drive systems.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention corresponds to a rotation amount of a tool rotation driving system, a work rotation driving system, and the tool rotation driving system. First to generate a number of pulses
Pulse generator, a second pulse generator interposed in the work rotation drive system and generating a number of pulses corresponding to the rotation amount, a first pulse generator and a second pulse generator. A synchronous operation control device for a gear grinding machine, comprising: a pulse classifier that receives an output; and a drive command signal generator connected to the output side of the pulse classifier, wherein the pulse classifier is the work rotation drive. A data storage unit for storing rotation error data of a rotation transmission mechanism of the system, the data storing unit having a number of bits proportional to the number of pulses generated during one rotation of the second pulse generator; An up / down counter that increases / decreases the pulse selection coefficient data based on the data read from the storage unit, and a first pulse generator and a subtraction counter connected to the up / down counter. , The subtraction counter is set with the pulse selection coefficient data that has been increased or decreased, and the set pulse selection coefficient data is subtracted by the pulse sent from the first pulse generator A drive signal of the work rotation drive system is sent to the drive command signal generator.

[Operation] Data relating to the error is read from the data storage unit by the output pulse of the second pulse generator and introduced into the up / down counter. In the up / down counter, the pulse selection coefficient data is corrected by the error data, and the corrected pulse selection coefficient data is set in the subtraction counter. The pulse generated by the first pulse generator is introduced into the subtraction counter and subtracted from the set pulse selection coefficient data, and when it reaches 0, an output signal of the work rotation drive system is output to the drive command signal generator. Be done.

[Embodiment] Next, a preferred embodiment of a synchronous operation control device for a gear grinding machine according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an external configuration of a gear grinding machine,
Among them, reference numeral 10 indicates a bed, and a cutting table 12 is arranged on the upper surface of the bed 10. Cutting table 12
Moves forward and backward in the direction of arrow A under the action of rotation of the cutting motor 14. A traverse table 16 is further arranged on the upper surface of the cutting table 12, and the traverse table 16 is provided.
Moves forward and backward by the traverse motor 18 in the direction of arrow A, that is, in the direction of arrow B. A gear, that is, a work 20 is arranged on the traverse table 16. This work 20 is rotated by a work spindle motor 22. On the other hand, a column 24 is arranged on the bed 10 in the traveling direction of the cutting table 12, and a swivel table 26 is held by the column 24. The swivel table 26 swivels in the direction of arrow C by a motor (not shown) arranged in the column 24. Further, a shift table 28 is provided on the swivel table 26, and the shift table 28 is driven by a shift motor 30. Move in the direction of arrow D. Shift table 28
A grindstone spindle unit 32 is attached to this. As shown in FIG. 2, the grindstone spindle unit 32 includes a grindstone rotation driving motor 34 and a first gear rotated by the motor 34.
36, a second gear 40 that meshes with the first gear 36, and a grindstone 38 is attached to one end of a rotation shaft of the first gear 36, and the second gear 40.
And a first pulse generator 42 that engages with the other end of the rotating shaft. The circular grindstone 38 is formed by engraving spiral grooves on its periphery.

On the other hand, on the work side, the work 20 is detachably supported on one end of the rotary shaft 44, and a relatively large-diameter gear 46 and a small-diameter gear 48 are axially supported on the other end of the rotary shaft 44. To be done.
The gear 46 meshes with a gear 52 attached to one end of the rotary shaft 50, and a gear 54 is rotatably supported on the other end of the rotary shaft 50. The gear 54 has a smaller diameter than that of the gear 56. Mesh with. The gear 56 is pivotally supported on one end of a rotary shaft 58 of the work spindle motor 22.

The gear 48 then meshes with a larger diameter gear 60. In this case, the gear 60 is rotatably held by a rotary shaft 62, and a second pulse generator 64 is attached to the other end of the rotary shaft 62. Two conductors 66 and 68 are derived from the second pulse generator 64 and connected to a pulse selector 70. The pulse selector 70 and the output side of the first pulse generator 42 are connected via a lead wire 72, and the output side of the pulse selector 70 is a drive command signal generator for driving the work spindle motor 22, that is, , And is connected to the motor driver 74 via a lead wire 76. In order to energize the work spindle motor 22, a lead wire 78 is led out from the motor driver 74 and is connected to the input side of the motor 22.

Next, the internal configuration of the pulse selector 70 will be described with reference to FIG.

The pulse sorter 70 includes a data section 80, and the data section 80
Is generated by one rotation of the second pulse generator 64
From the (+) data part 82 having positive data for correction proportional to the number of phase pulses, and the (-) data part 84 having negative data for correction of the same amount as this (+) data part 82. Basically composed. The data contained in the (+) data part 82 and the (-) data part 84 is for eliminating the error during the synchronous operation, which is particularly caused by the mechanical accuracy of the gears 46 and 52. As is clear from the figure, the plus data and the minus data consist of signals of 0 and 1, and as described above, the number of plus data and the number of minus data are equal. In this case, the data section 80 is connected to the first counter 85, and the first counter 85 is connected to a conductor.
The Z-phase pulse signal of the second pulse generator 64 is sent as a reset signal via 66, while the A-phase pulse signal of the second pulse generator 64 sent from the conductor 68 is sent as a clock signal. Is configured.

An output lead is derived from the (+) data section 82 and is connected to one input terminal of the first AND gate circuit 86, while an output lead from the (-) data section 84 is the second. Is connected to one input terminal of the AND gate circuit 88. The AND gate circuits 86 and 88 are configured so that the A-phase pulse signal of the second pulse generator 64 is introduced to the other input terminal of the AND gate circuits 86 and 88 through a lead wire 68.

By the way, the output side of the first AND gate circuit 86 is connected to the up port of the second counter 90, and the output side of the second AND gate circuit 88 is connected to the down port of the second counter 90. In addition to these outputs, data relating to a pulse selection coefficient described later is introduced into the second counter 90, and a set signal is introduced from a second delay circuit 96 described later.

Now, the output side of the second counter 90 is connected to one input terminal of the third counter 92. The signal of the first pulse generator 42 is introduced to the other input terminal of the third counter 92 via the lead wire 72. The output side of the third counter 92 is connected to the motor driver 74. In this case, the output side of the third counter 92 is connected to the first delay circuit 94 and the second delay circuit 96 which are branched and connected in series, and the first delay circuit
The output side of 94 is configured to branch and send the set signal to the third counter 92, and the output side of the second delay circuit 96 is connected to the second counter 90 and sends the set signal to it. Is configured.

Next, a method for obtaining the (+) data and the (-) data of the data section 80 will be described.

First, considering the effect that gear 46,52,54 and 56 constituting the gear train on the machining accuracy of the workpiece 20, as shown in FIG. 4, with respect to the ideal working curve L _1, pitch error, lead Due to an error, the processing accuracy curve L ₂ generally fluctuates slightly up and down. That is, in general, a read error Δle of the work 20 exists between the value indicated by the machining curve L ₁ and the actual machining accuracy curve L ₂ at the predetermined point X. Therefore, the read error Δle can be expressed by the following equation.

Δle = Al ・ rw ・ sin (θ + θ1) + A2 ・ rw ・ sin (θ ・ r12 + θ2) + A3 ・ rw ・ r23 ・ sin (θ ・ r12 + θ3) +4 ・ rw ・ r23 ・ sin (θ ・ r12 ・ r34 + θ4)… (Formula 1) However, A1 to 4: Equivalent amount of eccentricity converted from the amount of eccentricity, such as the deviation of tooth grooves of gears 46, 52, 54 and 56, pitch error, etc. Pitch diameter r12: Pitch diameter of gear 46 / Pitch diameter of gear 52 r23: Pitch diameter of gear 52 / Pitch diameter of gear 54 r34: Pitch diameter of gear 54 / Pitch diameter of gear 56 θ: arc tan (2X ・ tanβ / Pitch diameter of work) Here, β is a twist angle of the work θ1 to 4: initial phase angles of the gears 46, 52, 54 and 56. As a result, the following is understood from the first expression. That is, the influence of the error included in the gear 46 appears as the pitch error of the work 20, and the influence of the error included in the gear 52 is the work.
It appears as a lead error of 20. On the other hand, the influence of the error of the gear 54 and the gear 56 is relatively small, so that it is often negligible. That is, if the error contained in the gears 46 and 52 is corrected as much as possible, the accuracy of synchronous operation between the grindstone 33 and the workpiece 20 will be significantly improved.

Therefore, in order to meet the above object, the present invention utilizes the following device to obtain error data (see FIG. 5). That is, the third pulse generator 100 is attached to the rotary shaft 62 in place of the second pulse generator 64, and
Lead wires 102 and 104 from the pulse generator 100
6 Connect to one input side. On the other hand, the fourth pulse generator 108 is connected to one end of the rotary shaft 58, and the output side thereof is connected to the other input side of the CPU 106 via a conductor 110.

In such a configuration, if the work spindle motor 22 is driven to rotate, its rotational force is changed to the gear 56-54-52-46-
It is transmitted to the gear 60 via 48 and rotates the third pulse generator 100. Therefore, the CPU 106 causes the third pulse generator 10 to
With the introduction of the Z phase pulse of 0, the number of the A phase pulse sent from the fourth pulse generator 108 is read and this is continued until the arrival of the next Z phase pulse. During this time, CPU106
Reads the A-phase pulse sent from the third pulse generator 100, obtains the ratio of the A-phase generated pulses of the third pulse generator 100 and the fourth pulse generator 108, and calculates the ratio by this measured value. And the theoretical value, and treat this as an error.

FIG. 6 shows a plot of accumulated errors due to actual measurement with respect to the theoretical value of the number of A-phase pulses of the fourth pulse generator 108 based on the output pulse of the third pulse generator 100 relating to the A-phase. That is, FIG. 6 shows the third pulse generator 10
It shows how much the A-phase pulse of the fourth pulse generator 108 is generated with an error larger than the theoretical value for each cycle of the Z-phase pulse of 0. Here, the third pulse generator 100 is substantially the same as the second pulse generator 64 shown in FIG. 2, and this error Δ is the same as the second pulse generator 64 when the grindstone 38 and the workpiece 20 are in the synchronous operation state. It is a rotation angle error that occurs when one pulse generator 100 makes one rotation and that depends on the number of teeth of the work and the twist angle of the teeth.

Therefore, based on the above premise, when the value of Δ is rounded to be an integer, if a state in which the work side and the tool side are perfectly synchronized is represented by a horizontal straight line O, an error of The values are shown in the curve of FIG. Can be expressed as The values represented by small circles in FIG. 6 are cumulative errors. When this small circle changes to the plus side, 1 is set in the (+) data section 82 via the counter 85, and when it changes to the minus side, 1 is set in the (-) data section 84, and in all other cases It should be stored in ROM as 0.

Note that FIG. 6 has been simplified for easy understanding.

Next, a state in which the gear grinding machine of this embodiment is actually operated will be described.

First, when the grindstone rotation driving motor 34 of the grindstone spindle unit 32 is energized, the first gear 36 rotates and the first gear 36 rotates.
The second gear 40 that meshes with the 36 also rotates. Therefore, the grindstone 38 attached to one end of the rotary shaft and the first pulse generator 42 engaged with the other end of the rotary shaft start to rotate. As a result,
The first pulse generator 42 includes a second gear 40, that is, a grindstone 38.
The number of pulses corresponding to one rotation amount of
Pulse), and this pulse is introduced via a wire 72 to a third counter 92 constituting the pulse selector 70.

On the other hand, on the work side, the rotation of the work spindle motor 22 is transmitted to the work 20 via the gear trains 56-54-52-46 and further transmitted to the second pulse generator 64 via the gears 48 and 60. To be done. As a result, the second pulse generator 64
Generates a Z-phase pulse and an A-phase pulse, which are introduced into the pulse selector 70 via conductors 66, 68, respectively. The Z-phase pulse of the second pulse generator 64 corresponds to the zero point of the rotation and is generated once per rotation. On the other hand, the A-phase pulse of the second pulse generator 64 generates the number of pulses corresponding to the rotation angle.

Therefore, the A-phase pulse of the second pulse generator 64 is used as a clock signal, and the (+) data and (-) data of the data section 80 are read every time the clock signal counts, and the second counter 90 outputs the data. The introduced pulse selection coefficient data is corrected by the (+) data and (−) data as needed, and the corrected data is stored in the third counter 92.
Is set as the data in.

To explain this in more detail, the first of the pulse selector 70
When the Z-phase pulse is introduced into the counter 85 via the lead wire 66, the first counter 85 is reset, and the (+) data section 82 and the (-) data section 84 receive the respective A-phase pulse clock signals. The data is read.

Then, the data read from the (+) data section 82 is transferred to the A of the second pulse generator 64 in the first AND gate circuit 86.
An AND operation is performed with the phase pulse, and the result is input to the up port of the second counter 90. On the other hand, the data read from the (-) data section 84 is ANDed with the A-phase pulse output from the second pulse generator in the second AND gate circuit 88,
It is input to the down port of the second counter 90.

Here, the pulse selection coefficient data N will be described.

The pulse selection coefficient data N is given by the following equation.

N = (P1 / PM) ・ (T2 / TA) ・ (Z2 / Z1) ・ (Z4 / Z3) (Formula 2) However, P1: The number of pulses per revolution of the first pulse generator 42 PM : Number of drive pulses to the motor driver 74 required to rotate the work spindle motor 22 once T1: Number of teeth of the grindstone 38 T2: Number of teeth of the work 20 Z1: Number of teeth of the gear Z2: Number of teeth of the gear 52 Z3 : Number of teeth of gear 54 Z4: Number of teeth of gear 56 That is, the pulse selection coefficient data N is for the grindstone 38 and the workpiece.
The number of pulses generated by the first pulse generator 42 when it is assumed that the reduction gear interposed between the motor 22 and the workpiece 20 has perfect accuracy when 20 is meshingly rotating in synchronization. And the ratio of the number of drive pulses introduced to the motor driver 74, the ratio of the number of teeth of the work to the number of threads of the grindstone, the ratio of the number of teeth of the gear Z2 and the number of teeth of the gear Z1, the number of teeth of the gear Z4 and the gear Z3.
It is the product of the ratio with the number of teeth.

In other words, the data N relating to the pulse selection coefficient means that the pulse generated from the first pulse generator 42 is divided by the pulse selection coefficient data N so that the work 20 and the grindstone 38 are synchronously operated (for example, 54). In the frequency division, the value of N becomes 54). For example, assuming that there is no mechanical error between the gears 46 and 52, the pulse selection coefficient data N
Is set in the third counter 92 as it is, and the third counter 92 divides the output pulse of the first pulse generator 42 by N and outputs it to the motor driver 74 side. However, in the present invention, as described above, the mechanical error is eliminated by the gears 46, 52.
It is assumed that the pulse selection coefficient data N is (+) data from the data section 80.
It will be corrected with the (-) data.

The third counter 92 decrements the value of the corrected pulse selection coefficient data N set by 1 for each pulse input from the first pulse generator 42, and when the value becomes 0, the motor driver 74 Pulse is output to.

That is, the third counter 92 divides the number of pulses generated by the first pulse generator 42 by the pulse selection coefficient data N. When the set value of the pulse subtracted by the third counter 92 becomes 0 in this way, as described above, the third counter 92
An output pulse is output from the counter 92. This output pulse is output to the motor driver 74 via the lead wire 76.

When the pulse is input from the third counter 92, the motor driver 74 outputs a motor drive current to the work spindle motor 22 via the lead wire 78, and rotates the work spindle motor 22 by shifting it by one step. As a result, the work 20 rotates slightly via the gears 46, 52, 54 and 56 corresponding to the one step.

On the other hand, when the value related to the corrected pulse selection coefficient data set in the third counter 92 becomes 0, the third counter 92 outputs a pulse to the first delay circuit 94,
The delay circuit 94 outputs a signal for setting new corrected pulse selection coefficient data N to the third counter 92 after a lapse of a minute time. As a result, the contents of the second counter 90 when the set signal is input, that is, the new corrected pulse selection coefficient data is set in the third counter 92. On the other hand, the signal of the output pulse “0” of the third counter 92 is further input to the second counter 90 as a set signal via the second delay circuit 96 after a lapse of a short time. As a result, the signal related to the new pulse selection coefficient data is set in the second counter 90. When the pulse of the first pulse generator 42 is input in such a set state, the second counter 90 restarts the same operation as before, and the input signals from the first and second AND gate circuits 86 and 88 are input. In response to this, the pulse selection coefficient data N is increased or decreased again.

In this way, when the second pulse generator 64 makes one revolution,
All the data in the (+) data section 82 and the (-) data section 84 are read, and one data read cycle is completed. Then, the first counter 85 is reset again by the next Z-phase pulse generated by the second pulse generator 64, and the next data read cycle starts.

EFFECTS OF THE INVENTION According to the present invention, as described above, when the cutting tool rotated by the first rotary drive source and the work member rotated by the second rotary drive source are operated in synchronization, the rotation thereof is performed. A mechanical error of a transmission mechanism that decelerates and transmits is previously obtained as information, and the rotation of the rotary drive source is corrected and controlled based on this information. Therefore, it is possible to easily perform the operation with excellent synchronization accuracy without mechanically improving the accuracy of the transmission mechanism. That is, a highly accurate synchronous operation control device for a gear grinding machine can be obtained at a low price, and the assembly and adjustment of the rotational force transmission mechanism can be facilitated, resulting in a reduction in man-hours and eventually a reduction in manufacturing cost. Produce the desired effect.

The present invention has been described above with reference to the preferred embodiments.
The present invention is not limited to this embodiment, when a belt or chain is used instead of the gear,
Needless to say, various modifications can be made without departing from the scope of the present invention, such as application even when the number of gears forming the gear train is reduced.

[Brief description of drawings]

1 is a perspective view of a gear grinding machine, FIG. 2 is a circuit diagram of a synchronous operation control device of the gear grinding machine of FIG. 1, and FIG. 3 is an embodiment according to the present invention. FIG. 4 is a circuit diagram showing the internal configuration of the pulse selector shown in FIG. 2, FIG. 4 is an explanatory diagram showing the correlation between the ideal machining accuracy of the workpiece and the actual machining accuracy curve, and FIG. FIG. 6 is a circuit diagram of an apparatus for obtaining (+) (−) data, and FIG. 6 is a table showing error curves and (+) (−) data obtained by the apparatus of FIG. 10 …… bed, 12 …… cutting table 14 …… cutting motor, 16 …… traverse table 18 …… traverse motor, 20 …… work 22 …… work spindle motor, 24 …… column 26 …… swivel table, 28 …… Shift table 30 …… Shift motor, 32 …… Grinding wheel spindle unit 34 …… Grinding wheel rotation drive motor, 36 …… Gear wheel 38 …… Grinding wheel, 40 …… Second gear 42 …… First pulse Generator, 44 …… Rotary shaft 46, 48 …… Gear, 50 …… Rotary shaft 52,54,56 …… Gear, 58 …… Rotary shaft 60 …… Gear, 62… Axis 64 …… Second pulse generator , 66, 68 …… Conductor 70 …… Pulse sorter, 72 …… Conductor 74 …… Motor driver, 76, 78 …… Conductor 80 …… Data part, 82 …… (+) Data part 84 …… (−) Data section, 85 ... First counter 86 ... First AND gate circuit, 88 ... Second AND gate circuit 90 ... Second counter, 92 ... The third counter 94 ...... first delay circuit, 96 ...... second delay circuit

Continuation of front page (56) Reference JP-A-58-59728 (JP, A) JP-A-54-57285 (JP, A) JP-A-57-33944 (JP, A)

Claims (1)

[Claims] 1. A tool rotation drive system and a work rotation drive system,
A first pulse generator which is interposed in the tool rotation drive system and generates a number of pulses corresponding to the rotation amount; and a number of pulses which is interposed in the work rotation drive system and corresponds to the rotation amount. A second pulse generator, a pulse selector that receives the outputs of the first pulse generator and the second pulse generator, and a drive command signal generator connected to the output side of the pulse selector. A synchronous operation control device for a gear grinding machine provided, wherein the pulse selector is data of a rotation error of a rotation transmission mechanism of the workpiece rotation drive system, and the data is generated during one rotation of the second pulse generator. A data storage unit that stores data consisting of a number of bits proportional to the number of pulses that occur in the pulse generator, an up-down counter that increases or decreases pulse selection coefficient data based on the data read from the data storage unit, The subtraction counter includes a 1-pulse generator and a subtraction counter connected to the up / down counter, and the subtraction counter is set with pulse selection coefficient data that has been increased / decreased, and the set pulse selection coefficient data is generated by the first pulse generation. A synchronous operation control device for a gear grinding machine, characterized in that a drive signal of a work rotation drive system is sent to the drive command signal generator every time when the result of subtraction by the pulse sent from the machine becomes 0.