JP2718850B2 - Automatic meshing device in gear grinding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic meshing device in a gear grinding machine capable of automatically matching the phases of a gear and a grindstone.

[0002]

2. Description of the Related Art Conventionally, in a gear grinding machine, a tooth surface of a gear is ground by a grindstone. In this case, the phases of the gear and the grindstone must be matched.

Therefore, a technical idea for facilitating the phase adjustment between the gear and the grinding wheel is disclosed in Japanese Patent Publication No. Sho 62-38089, "Automatic meshing device in gear grinding machine".

The above-mentioned "automatic meshing device in a gear grinding machine"
Is the position of the grindstone and the gear from the signal indicating the amount of rotational displacement output from the rotary encoder attached to the tool shaft and a reference signal, and the signal output from the work sensor for detecting the tooth tip of the gear. The phase difference is detected, and the phase is automatically corrected based on the detection result.

In other words, if the phase difference between the reference signal output from the rotary encoder and the signal output from the work sensor for detecting the tip of the gear is constant, the phase between the gear and the grinding wheel is constant. In this case, the phase value is detected by counting a signal indicating the amount of rotational displacement output from the rotary encoder.

[0006]

However, the "automatic meshing device in a gear grinding machine" in the above-mentioned prior art is required.
In this case, a precondition is necessary that the gear is circular and not eccentric, that is, the phase of the detection signal for detecting the tooth tip of the gear is constant. However, some gears are eccentric, and in this case, the phase of a signal output from the work sensor for detecting the tooth tip of the gear changes according to the rotation angle, and the grinding wheel and the gear are automatically performed. Phase correction becomes unstable.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem. By correcting a change in phase data due to eccentricity of a gear, automatic phase correction between a grinding wheel and a gear can be stabilized. It is an object of the present invention to provide an automatic meshing device in a gear grinding machine which can be performed by using the automatic meshing device.

[0008]

In order to achieve the above-mentioned object, the present invention provides each tooth passing through the rotation of a gear having a pulse width corresponding to the detection time of each tooth, and A work detector that generates a detection signal in which the period of the center position of each pulse width is constant, and a rotation amount detector that is attached to a rotating shaft of a grinding wheel that grinds the gear and detects a rotational displacement amount of the grinding wheel. And the phase of the gear and the grinding wheel match.
The number of A-phase output pulses of the rotation amount detector between the zero point output of the rotation amount detector and the detection timing of the tooth from the work detector is adjusted by initial phase adjustment.
In the automatic meshing device in the gear grinding machine for automatically matching the number of pulses obtained by
A frequency dividing circuit that divides the phase output pulse by を to generate a 分 frequency-divided pulse;
And counted in 2 divided pulses, and eccentricity measuring means for determining the eccentricity of the teeth to be detected, the detection timing of the next tooth of the teeth of the detection target, counting the A phase output pulses of the rotation amount detector And a pulse width center position detecting means for outputting a coincidence signal when the count value coincides with the eccentricity amount, and delaying the detection signal to determine the start point of the pulse width of the detection signal as the coincidence signal. And a correction pulse output means for making the output time substantially the same as the output time point.

[0009]

The automatic engagement device in gear grinding machine according to the present invention, firstly, by the teeth of the gear pass through the workpiece detector in accordance with the rotation of the gear, each tooth from the workpiece detector, A detection signal having a pulse width corresponding to the detection time of each tooth and having a constant period at the center position of each pulse width is generated. On the other hand, from the rotation amount detector attached to the rotation shaft of the grinding wheel for grinding the gear,
A 0-point output and an A-phase output pulse are output as the grindstone rotates. Then, in this automatic meshing device, in order to match the phases of the gear and the grinding wheel, the rotation amount detection between the zero point output of the rotation amount detector and the tooth detection timing from the work detector is performed. It operates to automatically match the number of A-phase output pulses of the detector to the number of pulses obtained by the initial phase matching . While the coincidence operation is being performed, the frequency dividing circuit generates a 1/2 frequency-divided pulse obtained by dividing the A-phase output pulse by half, and the eccentricity measuring means , The pulse width of the detection signal is 1 /
The number of eccentricity of the tooth to be detected is obtained by counting with the frequency-divided pulse. Then, in the pulse width center position detecting means,
The detection timing of the next tooth of the tooth to be detected, said counting of the A-phase output pulses of the rotation amount detector is started and the count value match signal at the time of the match with the eccentric amount is outputted. This coincidence signal is input to the correction pulse output means,
In the correction pulse output means, the detection signal is subjected to delay processing so that the start time of the pulse width is made substantially the same as the output time of the coincidence signal. As a result, the phase of the pulse of the corrected detection signal is delayed to approximately the center of the pulse width of the detection signal pulse generated by the work detector. Since the cycle of the center position of each pulse width of the detection signal generated from this work detector is fixed, even if the work is eccentric, the cycle of the detection timing of each tooth is set to the case of the work without eccentricity. As in the case of (1), the counting of the A-phase output pulse output from the rotation amount detector can be stably performed regardless of the eccentric state of the work.

Next, when the work detection signal immediately after the gear pitch is measured is input, the phase signal correction means starts counting pulses output from the rotation amount detector. When the measured value matches the gear pitch, a coincidence signal is output.

The correction pulse output means derives a signal simulated by the coincidence signal with the center position of the tooth tip.

Therefore, the phase correcting means can derive a signal indicating the phase at the approximate center position of the tooth tip.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of an automatic meshing device in a gear grinding machine according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view showing an external structure of a gear grinding machine 10 embodying the present invention. The gear grinding machine 10 has a bed 12
The cutting table 14 is disposed on the upper surface of the
4 moves forward and backward in the direction of arrow A under the rotation of the cutting motor 16.

The cutting table 14, on which the traverse table 18 is disposed on the upper surface, is moved by a traverse motor 20 in a direction perpendicular to the direction of arrow A, ie, in the direction of arrow B.

On the traverse table 18, a work 22 composed of gears or the like and a work sensor 24 are arranged in proximity to the work 22. The work 22 rotates under the rotation of the work spindle motor 26.

The work sensor 24 detects the number of teeth of the work 22 rotated by the work spindle motor 26 by a proximity switch and generates a predetermined pulse.

On the other hand, a column 28 is arranged on the bed 12 in the direction of travel of the cutting table 14 and a turning table 30 is held on the column 28. The turning table 30 is turned in the direction of arrow C by a motor (not shown) provided in the column 28, and a shift table 32 is further provided on the turning table 30. The shift table 32 includes a shift motor 34. The arrow D
Move in the direction. A grindstone spindle unit 36 is engaged with the shift table 32.

As shown in FIG. 2, the grindstone spindle unit 36 has a grindstone spindle motor 38, a first gear 40 rotated by the grindstone spindle motor 38, meshes with the first gear 40, and has one of its rotating shafts. It is basically composed of a second gear 44 on which the grinding wheel 42 is mounted at the end, and a first pulse generator 46 which engages with the other end of the rotation shaft of the second gear 44.

The grindstone 42 has a circular shape, and several grooves are formed on the periphery thereof.

On the other hand, as shown in FIG. 3, the work 22 is detachably supported on one end of a rotary shaft 48 via a pair of clamp jigs 50, and an electromagnetic clutch is mounted on the other end of the rotary shaft 48. A relatively large-diameter gear 54 is pivotally supported via 52. The gear 54 meshes with a gear 56 having a smaller diameter, and the gear 56 is supported by a shaft 58. One end of the shaft 58 is connected to the work spindle motor 26 via the coupling 60, and the other end is connected to the second pulse generator 62.

A control circuit 63 for controlling the gear grinding machine 10 configured as described above will be described with reference to FIG.

The output terminal of the first pulse generator 46 provided on the grinding wheel spindle unit 36 for outputting the A-phase pulse is connected to the input terminals of the indexing operation circuit 64, the counter circuit 66 and the phase correction circuit 68. . Indexing operation circuit 64
Is connected to the input terminal of the AND gate 70, and the other output terminal is connected to the input terminal of the AND gate 72.

The output terminal of the AND gate 70 is connected to the input terminal of the OR gate 74, and the output terminal of the AND gate 72 is connected to the control terminal of the OR gate 74. The output terminal of the OR gate 74 is connected to the input terminal of the amplifier circuit 76, and the output terminal of the amplifier circuit 76 is connected to the work spindle motor 26. That is, the output signal of the OR gate 74 is amplified by the amplifier circuit 76 and the work spindle motor 26 is energized.

An output terminal of the first pulse generator 46 for outputting a zero-point signal is connected to a control terminal of a counter circuit 66, and is also connected to a control terminal of a count memory circuit 78. It is connected to the input terminal of the count memory circuit 78. One output terminal of the count memory circuit 78 is connected to the control terminal of the AND gate 72, and the other output terminal is connected to the control terminal of the AND gate 70.
0 input terminal.

The output terminal of the counter circuit 80 is connected to the input terminal of the AND gate 82, and the output terminal of the AND gate 82 is connected to the input terminal of the amplifier circuit 84. The output terminal of the amplifier circuit 84 is connected to the cutting motor 16, and a cutting command signal for the work 22 is introduced to the control terminal of the AND gate 82.

The output of the work sensor 24 facing the work 22 is connected to a waveform shaping circuit 86 for shaping the waveform. The output terminal of the waveform shaping circuit 86 is connected to the other input terminal of the phase correcting circuit 68. The output terminal 68 is connected to the control terminal of the counter circuit 66 and the control terminal of the count memory circuit 78.

In the figure, reference numeral 88 denotes an amplifier circuit for amplifying a signal for automatically engaging the work 22 with the grindstone 42.
2 is introduced.

FIG. 5 is a block diagram showing the structure of the phase correction circuit 68.

A signal output from the work sensor 24 is supplied to a work pitch measuring circuit 92 via an inverter gate 90.
And a correction pulse output circuit 98 via an inverter gate 94.

On the other hand, the A-phase pulse train output from the first pulse generator 46 is input to the correction circuit 96 and also to the 1/2 frequency dividing circuit 100, and the output signal of the 1/2 frequency dividing circuit 100 is output. Is input to the work pitch measuring circuit 92 and the correction pulse output circuit 98.

The pulse width data output from the work pitch measuring circuit 92 is input to a correction circuit 96 and a correction pulse output circuit 98, and the enable signal ph-EN output from the correction circuit 96 is input to a correction pulse output circuit 98. Is done. The output of the correction pulse output circuit 98 is input to the counter circuit 66 and the count memory circuit 78 as described above.

The operation of controlling the gear grinding machine 10 by the control circuit 63 configured as described above will be described with reference to FIGS.

First, the initial phase adjustment of the grindstone 42 and the work 22 is performed. The information on the module and the number of teeth of the work 22 obtained by the initial phase adjustment is used to continuously grind a plurality of the same works 22. It is used when you do.

In the initial state, the electromagnetic clutch 52 is deenergized (step S1), so that the rotating shaft 48 can be easily rotated manually. Next, the cutting motor 16 is energized to advance the cutting table 14 (step S2). At this time, since the grindstone spindle motor 38 is inactive, the grindstone 42 stops rotating.
Therefore, the operator engages the grindstone 42 and the work 22 to perform phase adjustment.

Next, the grindstone 42 is rotated by rotating the grindstone spindle motor 38 at a low speed (step S3).
In order to rotate the work spindle motor 26 in synchronization with 8, the work 22 rotates in the direction opposite to the rotation direction of the grinding wheel 42.

In such a state, starting from the zero-point signal output from the first pulse generator 46, an A-phase pulse output from the first pulse generator 46 until a pulse is output from the work sensor 24. The number N is counted (step S4) (see FIG. 7). That is, the A-phase pulse and the zero-point signal of the first pulse generator 46 are introduced to the counter circuit 66.

On the other hand, the waveform signal from the work sensor 24 is once shaped into a pulse by the waveform shaping circuit 86 and then introduced into the counter circuit 66 via the phase correcting circuit 68. The counter circuit 66 counts the A-phase pulse from the time when the zero-point signal is introduced to the time when the signal from the work sensor 24 is introduced. The counted number of pulses N is stored in the count memory circuit 78. At the same time, the A-phase pulse of the second pulse generator 62 is counted from the first pulse output time obtained from the work sensor 24, and is continued until the next pulse is output from the work sensor 24. In this case, the count number is set to M (see FIG. 7).

Therefore, the following equation holds for the count number M.

M = 1 / Z2 × P2 × T1 / T2 (1) where Z2: number of teeth of the work T1: number of teeth of the gear 54 T2: number of teeth of the gear 56 P2: 1 of the second pulse generator 62 Number of A-phase pulses per rotation Accordingly, if the number of teeth Z2 of the work 22 to be mounted on the rotating shaft 48 is known in advance, the count number M becomes a definite value. Therefore, if the counter circuit 66 is provided with a digital display function in advance, the measured value m different from the theoretical value M can be obtained.
Is displayed on the counter circuit 66, it is estimated that the workpiece 22 is erroneously loaded, the output of the work sensor 24 is defective, or a defective workpiece is loaded (step S5).

When the theoretical value (M) matches the measured value (m), the driving of the grindstone spindle motor 38 is stopped (step S6), and at the same time, the rotation of the work spindle motor 26 is also stopped. Then, the cutting motor 16 is re-energized to retreat the cutting table 14 to complete the initial phase adjustment (step S7).

At this time, it should be noted that the pulse number N is held in the count memory circuit 78 as it is. Of course, when the theoretical value (M) is different from the measured value (m), the work 22 infers an erroneous insertion or the like, and it is needless to say that the work 22 needs to be detached.

Next, a step of automatically meshing the grindstone 42 and the work 22 using the value N stored in the count memory circuit 78 at the time of the initial phase adjustment will be described with reference to FIG.
This will be described with reference to the flowchart of FIG.

When the grindstone spindle motor 38 is energized in a state where the work 22 is attached, the work spindle motor 26 which is electrically connected thereto is also driven, and the two enter a synchronous operation. Then, when the electromagnetic clutch 52 is energized (step S10), the work 22 rotates under the rotation of the work spindle motor 26 (step S11). In this state, if the cutting motor 16 is energized, the cutting table 14 moves forward gradually (step S12), but before the work 22 and the grindstone 42 mesh with each other,
Once, the cutting motor 16 is deactivated. This is because, in the normal state, the work 22 is out of phase with the grindstone 42, and it is necessary to correct it.

Then, starting from the zero-point signal of the first pulse generator 46, the signal A is output until the work sensor 24 outputs.
The number N ′ of phase pulses is counted by the counter circuit 66 and is derived to the count memory circuit 78. As a result,
In the count memory circuit 78, the value N already stored is compared with the value N ′ counted this time (step S13). When N and N 'are equal, this indicates that there is no phase shift, and just in case, the count of the value N' is continued a predetermined number of times (K times) via the counter circuit 80 (step S14). If they are also equal, the signal is introduced to the AND gate 82 (see FIG. 9).

When a cutting command signal is input to the control terminal of the AND gate 82, the AND gate 82 is opened, and the signal is sufficiently amplified by the amplifier circuit 84 to energize the cutting motor 16 and the cutting table 14 Is advanced (step S15). On the other hand, the signal relating to the equivalent value is introduced into an AND gate 70, and a rotation signal n / α having a normal cycle from the indexing operation circuit 64 is introduced into the AND gate 70. Is opened. This signal is introduced into the OR gate 74, and the work spindle motor 26 is operated synchronously via the amplifier circuit 76 to shift to a normal grinding process.

When the value N 'is not equal to the stored value N, this means that there is a phase shift between the grindstone 42 and the work 22. Therefore, the signal is introduced into the input terminal of the AND gate 72. Since the signal n / α ′ relating to the phase shift from the index calculation circuit 64 is introduced into the control terminal of the AND gate 72, The AND gate 72 is opened. Therefore, the output signal of the AND gate 72 reaches the amplifier circuit 76 via the OR gate 74, and increases or decreases the rotation speed of the work spindle motor 26 according to the value N '(step S16). By repeating this, a value N ′ substantially equal to the value N is finally obtained, and the phase shift is eliminated. That is, the n / α signal from the indexing operation circuit 64 and the signal of N ≒ N ′ from the count memory circuit 78 enter the AND gate 70, the output signal of which opens the OR gate 74, and the whetstone 42 and the work 22 Is returned to normal, and thereafter, the workpiece 22 maintains the same phase with respect to the grindstone 42. In this case, the count memory circuit 7
In N, since N ≒ N ', the coincidence signal is introduced to the counter circuit 80, and the cutting motor 16 is energized after K times of confirmation checks, as described above.

If the work 22 is eccentric or is mounted eccentrically, FIG.
As shown in (a) to (d), since the distance Y between the work 22 and the work sensor 24 changes according to the rotation angle, the pulse width and generation timing of the output pulse of the work sensor 24 change. Therefore, the phase correction circuit 6 shown in FIG.
8, the output pulse of the work sensor 24 is corrected, so that A
A reference pulse for accurately counting the number of phase pulses N is output to the counter circuit 66 and the count memory circuit 78.

The operation of correcting the output pulse of the work sensor 24 by the phase correction circuit 68 will be described with reference to FIGS. 4, 5, 10 and 11.

FIG. 11A shows a pulse output from the work sensor 24 when the work 22 is not eccentric, and FIG. 11B shows a pulse output from the work sensor 24 when the work 22 is eccentric. Is shown. FIG.
As can be understood from (a) and (b), focusing on the fact that the phase of the central portion of the output pulse at the time of eccentricity is substantially the same as the phase of the central portion of the output pulse at the time of normality, Is corrected to the phase at the center of the normal output pulse (see FIG. 11D).

That is, as shown in FIG. 4, the work detection signal wks whose waveform has been shaped by the waveform shaping circuit 86.
s and the A-phase pulse signal ph-A output from the first pulse generator 46 are input to the phase correction circuit 68.

The work pitch measurement circuit 92 of the phase correction circuit 68 includes the work detection signal wkss and the 1/2 frequency divider 1
A-phase pulse signal 1/2 divided by 1/2 by 00
ph-A is input, the work pitch measuring circuit 92
Starts counting the A-phase pulse signal ｐｈ ph-A, which is the output of the 分 divider circuit 100, by the (n−1) th positive edge of the work detection signal wkss (n−1), The counting is terminated at the negative edge of wkss (n-1), and the count data P _n-1 is output to the correction circuit 96 and the correction pulse output circuit 98. The correction circuit 96 and the correction pulse output circuit 98 store the count data P _n-1 in their respective storage circuits.

Next, the correction circuit 96 detects the (n-1) th count data P stored in the storage circuit by the next positive edge of the nth work detection signal wkss (n).
_n-1 is decremented by the A-phase pulse signal ph-A. When the stored count data _Pn-1 becomes "0", the enable signal ph is sent to the correction pulse output circuit 98.
-EN is output.

At this time, the time required for the count data P _n-1 to be decremented by the A-phase pulse signal ph-A to "0" is approximately 1/2 of the work detection signal wkss (n). .

On the other hand, the correction pulse output circuit 98 outputs the n-th 1/2 frequency-divided A-phase pulse signal 1/2 ph-A
And the work detection signal wkss (n) are input, and when the enable signal ph-EN is input, the output signal is turned “ON” and the (n−1) -th count data P _{n−1 is changed} to the n-th count data. Is started by the A-phase pulse signal 1/2 ph-A, and when the count data P _n-1 becomes “0”, the output signal is turned “OFF”.

With such an operation, the positive edge of the output signal output from the correction pulse output circuit 98 to the counter circuit 66 and the count memory circuit 78 is a work detection signal w detected when the work is not eccentric.
kss (n) is substantially at the center of the phase (see FIG. 11D), and by such repetition of the operation, the work detection signal wkss always detected when the work is not eccentric.
An output signal in which the phase at the substantially central portion becomes a positive edge is obtained.

As described above, in this embodiment, the positive edge of the work detection signal wkss for controlling the counter circuit 66 and the count memory circuit 78 corresponds to the work detection signal wkss detected when the work is not eccentric. The phase correction circuit 68 corrects the phase so that the phase is substantially at the center, so that even if the workpiece is eccentric, the counting of the A-phase pulses output from the first pulse generator 46 can be stably performed. This makes it possible to automatically correct the phase between the work 22 and the grindstone 42.

[0058]

In the automatic meshing device in the gear grinding machine according to the present invention, since the phase correction means derives the center position of the tooth tip of the gear and the simulated phase signal, the phase data of the tooth tip due to the eccentricity of the gear is obtained. The change can be corrected, and the automatic phase correction between the gear and the grindstone can be stably performed.

Therefore, it is possible to suppress the failure of gear processing by the gear grinding machine, to improve the processing quality, and to improve the productivity.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an external configuration of a gear grinding machine that implements an automatic meshing device according to the present invention.

FIG. 2 is an explanatory diagram showing a correlation between a grindstone and a work shown in the embodiment of FIG.

FIG. 3 is an explanatory diagram showing a correlation between a work, a pulse generator, and a work spindle motor for driving them in the embodiment shown in FIG. 1;

FIG. 4 is a block diagram of a control circuit of the embodiment shown in FIG. 1;

FIG. 5 is a block diagram of the phase correction circuit shown in FIG. 4;

FIG. 6 is a flowchart of an initial phase adjustment of the embodiment shown in FIG. 1;

FIG. 7 is a time chart of an initial phase adjustment of the embodiment shown in FIG. 1;

FIG. 8 is a flowchart of the automatic engagement of the embodiment shown in FIG.

FIG. 9 is a time chart for automatic engagement of the embodiment shown in FIG. 1;

10 is a diagram illustrating an output of the work sensor of the embodiment shown in FIG.

11 is a diagram illustrating an output of the work sensor of the embodiment shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Gear grinder 12 ... Bed 14 ... Cut table 16 ... Cut motor 18 ... Traverse table 20 ... Traverse motor 22 ... Work 24 ... Work sensor 26 ... Work spindle motor 28 ... Column 30 ... Rotating table 32 ... Shift table 34 ... Shift motor 38 ... Whetstone spindle motor 42 ... Whetstone 46 ... First pulse generator 52 ... Electromagnetic clutch 64 ... Indexing operation circuit 66,80 ... Counter circuit 68 ... Phase correction circuit 76,84,88 ... Amplification circuit 78 ... Count memory circuit 86 ... waveform shaping circuit 92 ... work pitch measuring circuit 96 ... correction circuit 98 ... correction pulse output circuit 100 ... 1/2 frequency dividing circuit

Claims (1)

(57) [Claims] 1. For each tooth passing with the rotation of the gear,
It has a pulse width corresponding to the detection time of each of these teeth, and
A work detector that generates a detection signal in which the period of the center position of each pulse width is constant; and a rotation amount detector that is attached to a rotating shaft of a grindstone that grinds the gear and detects a rotational displacement amount of the grindstone. The number of A-phase output pulses of the rotation amount detector between the zero point output of the rotation amount detector and the detection timing of the tooth from the work detector in order to match the phases of the gear and the grinding wheel. Is the pulse obtained by initial phase matching
An automatic meshing device in a gear grinding machine for automatically matching a number to a number , wherein a frequency dividing circuit for dividing the A-phase output pulse of the rotation amount detector by half to generate a 1/2 frequency-divided pulse; by counting the pulse width of the detection signal by the 1/2 frequency division pulse, the eccentricity measuring means for determining the eccentricity of the teeth to be detected, the detection timing of the next tooth of the teeth of the detection target, the amount of rotation A pulse width center position detecting means for starting counting of an A-phase output pulse of the detector and outputting a coincidence signal when the counted value coincides with the eccentricity amount ; An automatic meshing device for a gear grinding machine, comprising: at least a phase correction unit comprising: a correction pulse output unit configured to set a start point of a pulse width substantially equal to an output time point of the coincidence signal.