JPS59232750A - Neumeric control method - Google Patents

Abstract

PURPOSE:To rework a screw accurately through simple prework, by producing a single rotation signal at the gearing position and controlling to correct the delay of work. CONSTITUTION:When grinding a work by a gear grinder, a grinding wheel 101 and a work 102 are geared under stopped state of a spindle motor 103. Upon production of a gearing complietion signal by depressing a gearing depression button, a controller will reset a reversible counter for producing a single rotation signal to zero. Then the grinding wheel 101 and the work 102 are separated to set the grinding wheel to the start-of-work position thus to rotate the grinding wheel 101 and to command the number of teeth (N) while to command start of work. Thereafter, a single rotation signal is produced from a reversible counter and the controller will devide the frequency of pulses produced from a position coder 104 in accordance to the number of teeth (N) thus to start synchronous rotation of work 102 by means of the frequency divided pulses. After reaching to steady state, delay of servo system is corrected to perform grinding by means of the grinding wheel 101.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a numerical control method, and particularly to a numerical control method suitable for reworking or grinding threaded or geared screws or gears.

If you want to recut or grind a gear that has been cut, or if you want to rework a screw that has been turned once after it has been removed from the processing machine for some reason, such as for dimensional correction, the grinding wheel has already been machined. The position must be controlled so that it fits perfectly on the teeth, or the thread cutting tool must be set so that it correctly traces along the thread, then it must be ground or reworked. For this reason, conventionally, a mark is placed before removing the workpiece, and when installing or installing the workpiece, the mark is referred to and the workpiece is installed in the exact same position as before removal, or after the workpiece has been installed appropriately, a trial Due to a mistake, adjustments were made such as shifting the signal generation position for one rotation of the main spindle or shifting the thread cutting start position. However, this method was not preferable because the adjustment work was troublesome.

In view of the above, an object of the present invention is to provide a numerical control method that allows grinding or reworking to be performed with high precision by performing simple preliminary work.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a schematic explanatory diagram of a gear grinding machine. A grindstone 101 is arranged to face a workpiece (gear) 102, and is rotated by an AC spindle motor 105 at a predetermined rotational speed. A position encoder 104 is attached to the spindle motor 105, and the spindle motor 10
One rotation signal is generated every time 3 rotates once, and one pulse (for example, 4096 pulses per one rotation) is generated every time the driver rotates by a predetermined angle. The whetstone 101 is rotatably attached to a frame 105, and the frame 105 is placed on a whetstone shift slide 106 and can move in the Y-axis direction, and the whetstone shift slide 106 is placed on a whetstone cutting slide 107. X-axis direction (cutting direction)
It is now possible to move to. Therefore, the grindstone 101 is rotatable at a constant speed and is movable in the X and Y axis directions. The gear 102 is the Vosisilon coder 1
It is configured to rotate in synchronization with the pulses generated from 04 (this rotation axis is referred to as the work rotation axis), and is also configured to be able to move up and down in the X-axis direction (up and down direction).

Next, a first reprocessing and grinding method according to the present invention will be explained.

(A) First, the grindstone 101 and the workpiece 102 are meshed with the spindle motor 105 stopped, that is, with the grindstone 101 and the workpiece (gear) 102 stationary.

(b) Upon completion of tooth alignment, when a tooth alignment complete signal is generated by pressing the alignment completion button provided on the operation panel (not shown), the controller device (described later) uses a built-in one-rotation signal generation signal. Reset the reversible counter to zero. The reversible counter is configured so that when a one-rotation signal is generated from the position coder 104 at the initial stage, its contents become zero.
In addition, the pulses generated every predetermined rotation of the spindle motor 103 are reversibly counted according to the rotation direction, and the count returns to zero with 4096 pulses generated per one rotation (the capacity of the reversible counter is 4096 (=2”
). However, when the gearing completion signal is generated, the contents of the reversible counter are cleared to zero, and from then on, the contents of the reversible counter are cleared to zero.
An overflow pulse or borrow pulse is generated every time 96 pulses are generated, and the overflow pulse and hypolow pulse are used as one rotation signal. In other words, the position where the one-rotation signal is generated is shifted by the tooth alignment position.

(c) Next, the grindstone 101 and the workpiece 102 are separated, the grindstone is set at the processing start position, and the corresponding rear-limb grindstone 101 is rotated.

(Then, command the number of teeth N and command the start of machining.

09 After commanding to start machining, when a one-rotation signal is generated from the reversible counter, the control device changes the pulses generated from the Vosisilon coder 104 according to the number of teeth N (so that the workpiece rotates once while the grindstone rotates by the number of teeth N). The frequency is divided, and synchronous rotation of the workpiece (southeast) 102 is started by the frequency division pulse.

(v) After the rotational speed of the workpiece (gear) 102 reaches a steady state, in other words, after a predetermined time that takes into account the delay time of the servo system, the actual delay amount ε4 of the servo system is checked and the delay amount is canceled. Give an extra movement command by the amount of delay f″L.

(G) After the correction is completed, a correction completion signal is generated, and the correction completion signal causes the grindstone 101 to move in the X-axis direction (cutting direction) (
/C and perform grinding.

FIG. 2 is a block diagram for realizing the grinding method according to the present invention. The flip-flop 201 is normally set and is reset by the alignment completion signal TC5.

The reversible counter 202 has a capacity of 4096 (=212), and its contents are normally cleared by the one-rotation signal RTS generated from the position pulse 104 (when the flip-flop 201 is set), and the count value becomes zero when the one-rotation signal is generated. After that, the position pulse PP generated every time the spindle motor 106 rotates by a predetermined angle is counted up or down depending on the direction of rotation. The reversible counter 202 outputs the correction completion signal TC3-i to the differentiating circuit 20.
Its contents are cleared by the rising pulse BUP generated from 5.

After that, while counting the position pulse PP, 4096
After generation of the position pulse PP, an overflow pulse or a voltage pulse (hereinafter referred to as the j&M positive one-time transmission signal) CR3 is generated. flip flop 204
is set by the processing start signal MST, and the timer 205
is a predetermined time 1 after the flip frog 204 is set.
When ゛a has elapsed, the time oat < iva TOV is output. The frequency dividing circuit 206 generates a position pulse 1 based on the input number of teeth N, and generates a correction one rotation signal cR5lc1gJ.
The frequency of the horizontal pulse PP generated from 04 is divided. In addition, the workpiece (gear) 10 for one rotation of the grindstone 101
The amount of 20 rotations is 1/'N rotation.

Therefore, the frequency of the position pulse PP is divided based on the number of teeth N, and the rotation of the workpiece can be synchronized with the rotation of the grindstone and the workpiece by the frequency-divided pulse pd. Divided pulse p
d is input to the workpiece rotation servo circuit 209 via the OR gate 207, and rotates the workpiece rotation morph 210. Time over signal TOV after driving motor 210
When turned on, the correction pulse generation circuit 21r reads from the servo circuit 209 the delay amount of the servo system for rotating the workpiece, and outputs ε correction pulses Pc. The servo circuit 209 (a) counts up the pulses output from the OR gate 207, counts down the pulses generated from the pulse coder 20B every time the motor 210 rotates by a predetermined amount, and calculates the command 6 and the actual movement. (b) a DA converter that generates an analog voltage proportional to the error; (c) a speed control circuit; and (c) other circuits.

Therefore, since the delay amount of the servo system 6 is equal to the contents of the error register, when the correction pulse generation circuit 212 time-over signal TOV is generated, the error l/register contents are read as the delay amount εA, and 64 correction pulses are generated. Generates Pc.

FIG. 3 is a block diagram for realizing another reprocessing and grinding method according to the present invention. To 2 In the embodiment shown in Fig. 2, a correction pulse Pc is generated to correct the workpiece position so as to correct the delay amount of 6 people from the commanded position of the workpiece (gear) 102, but the actual MI example shown in Fig. 5 In this case, the one-rotation signal generation position is corrected in accordance with the delay signal so that the same effect as in FIG. 2 can be obtained in terms of value.

Enjoy, rework gears, or grind 1 unit per unit
102 (11th ¥') delay - M:ip(
degl, or of the thread cutting tool in the case of reprocessing thread cutting) j% f'L'('H; εp (mm) is generally the command method Kl (deg/sec or rat +11[T1/
Since the command speed FC is proportional to
16, the delay amount εI) can be predicted using the following formula %[11 (where C is a constant specific to the system). 1. By the way, the command method 1 pci" is the rotational speed of the spindle vS (rev/sec) and the main qth + 42'4dit (for gear grinding and bob cutting, N is the number of teeth. 4- and 560°/N, and in the case of thread cutting, it is calculated by the following formula % formula % (:). Therefore, according to formulas (1) to (3), Q;
+ji iL i%Jεp is or εp = C- to -Vs (5), and the angle θ of one rotation signal to be shifted (advanced) is εp O=-・560° (N)
becomes. Therefore, in the case of gear grinding and hobbing reprocessing, the angle given by equation (6), and in the case of thread cutting and reworking, the angle given by equation (7) is 1 revolution. Shifting allows the grinding wheel to fit perfectly against the newly machined teeth during grinding or reworking, or the threading tool to correctly trace along the already machined thread. Furthermore, (6),
(7) One rotation of the can by the angle θ that accepts the equation: To shift the waste, the first correction 1 of the brass generated from the reversible counter 2C12
The number I1^M θ M determined by the following formula may be set to □·4096 (8)60 in the reversible counter by the rotation signal CRS.

Next, the operation shown in FIG. 5 will be explained.

(a) With the mass and spindle motor 103 stopped, the grindstone 101 and gear 102 are meshed (see M in Figure 1).

(b) When the tooth alignment is completed, press the tooth alignment completion button provided on the operation panel (not shown). As a result, the toothing completion signal TC
3 occurs, flip-flop 301 is set, and after one clock pulse time, flip-flop 502 is set. As a result, a pulse is generated for one clock time 11'' from the anime game) 303 and the reversible counter 202
The content of is reset to zero (flip-flop 301
~302, a differential circuit is formed by the anchor 605). Although not shown, the reversible counter 202 is initially configured so that its content becomes zero when the one-rotation signal RTS is generated from the position encoder 104. PP is reversibly counted according to the direction of rotation, and returns to zero after 4096 pulses are generated per rotation. However, when the toothing completion signal TC3 is generated, the contents of the reversible counter 202 are cleared to zero, and every 4096 pulses generated thereafter, an overflow pulse or a hypolow pulse is generated. One rotation signal (referred to as corrected one rotation signal) becomes CR5. Therefore, the above-mentioned toothing completion signal T
The reset operation by C3 shifts the one-rotation signal generation position to the tooth alignment position.

(c) Next, the grindstone and the workpiece are separated, the grindstone is set at the processing start position, and then the spindle motor (grindstone) is rotated at a steady speed.

4. As the spindle motor 103 rotates, a pulse PP is generated from the position coder 104, and the pulse PP is inputted to the reversible counter 202 and the speed detector 505.

The reversible counter 202 counts the pulses, and when the pulse train PP is input to the speed detector 305, the rotational speed V8 of the spindle motor 105 is detected by a known method and inputted to the preset value calculation circuit 606.

← The reset value calculation circuit 506 (4), (6),
A preset value M is calculated from equation (8).

N After 1 is calculated to the series reset value, reversible color/re 2
When the one-rotation signal CR3 is generated from 02, the flip-flop 301 is reset, and after one clock sys time, the flip-flop 302 is reset to 1. As a result, a preset enable signal is generated from the AND gate 305, and the value M is preset in the reversible counter 304.

Through the above processing, the one-rotation signal CR5 has been advanced by the angle shown in equation (6) from the tooth alignment position.

(G) When the machining start command MST is issued, the frequency dividing circuit 206 divides the pulse PP generated from the position coder 104 according to the number of teeth (N) in synchronization with the one-rotation signal CR3. The frequency is divided so that the workpiece rotates once while rotating by the number of teeth N, and the workpiece (gear) is rotated synchronously by the pulse pd. That is, the frequency divided pulse p
d is input to the servo rotation M 209 and rotates the motor 210 for rotating the workpiece.

As described above, in the example shown in Fig. 3, the generation position of the one-rotation signal was shifted (advanced) by an amount corresponding to the amount of delay of the workpiece from the commanded rotational position, so that the grinding wheel was perfectly aligned with the vertically machined teeth. Grinding is performed accordingly.

By the way, in FIG. 3, the shift i of the one-rotation signal is calculated based on the formula (4), ((1>, (8)), and the one-rotation signal generation position is shifted by the shift record. ) If the amount of delay εp predicted by the formula does not match the actual distance -εA, a grinding error will occur.Therefore, a method of correcting the amount of delay by combining the first and second embodiments is also effective1. Fig. 4 is a Bukok diagram of an embodiment of the above method, and the same parts as in Fig. 2 and Fig. m13 are given the same reference numerals. is added to FIG. 6 and is the fc part.

When the machining start command MST is generated, flip-flop 2 is activated.
04 is set, and the timer 205 starts measuring time and generates a time-over signal TOV after the predetermined time Ta has elapsed. When the time-over signal TOV is generated, the correction pulse generation circuit 212 calculates the delay signal εp, which is the calculation result of equation (4) inputted from the preset value calculation circuit 306, and the actual delay amount read from the error register of the servo circuit 209. The difference in εA is calculated and εA-εp) correction pulses PC are output to the servo circuit 209 via the pulse synthesis circuit 401.

As described above, according to the present invention, since the one-rotation signal is sacrificed at the tooth alignment position and the workpiece delay amount is corrected, it is possible to perform grinding and re-machining of screws with high precision with simple pre-work. did it.

Although the case of gear grinding is described in detail below, it goes without saying that the present invention can also be applied to the case of remachining screws using a lathe.

[Brief explanation of the drawing]

Figure 1 is a schematic explanation of a gear grinder, a clear diagram, Figure 2, Figure 5,
- Figure 4 is a block diagram for realizing the method of the present invention. 101... Grindstone, 102... Work (gear), 10
3-°. AC spindle motor, 104゛°・position coater, 105...frame, 106-゛・grindstone shift slide, 107...grindstone cutting slide, 202...
Reversible counter, 205... Timer, 206... Frequency dividing circuit, 209... Sir, O circuit, 211... Speed detector, 212... °° correction Papal power generation circuit, 214...
...Wheelstone cutting position control circuit, 505...Speed detector,
306...Glicent performance, f,: [n! circuit, 40
1...) Pulse synthesis circuit. Patent applicant: Representative of FANUC Co., Ltd. Patent attorney: Minoru Tsuji (external name: Figure 1)

Claims (3)

[Claims] (1) In a numerical control method for reworking or grinding threaded or geared screws or gears,
With the main spindle stopped, align the thread cutting tool or grindstone with the workpiece, make sure that a signal for one revolution of the main shaft is generated at the alignment position, and after releasing the engagement between the thread cutting tool or grindstone and the workpiece, start the thread cutting. Set the tool or grindstone at the machining start position, rotate the main spindle at a steady speed, and after the main spindle 1 rotation signal is output, the pulse generated every time the main spindle rotates by a predetermined angle will cause the thread cutting to be performed properly. In the case of gear rotation machining or grinding, the workpiece is rotated in synchronization with the spindle, and then the actual delay amount from the commanded position of the thread cutting tool or workpiece is corrected, and remachining or grinding is performed. A numerical control method characterized by performing the following. (2) In a numerical control method for reprocessing or grinding threaded or geared screws or gears,
Align the thread cutting tool or grindstone with the workpiece while the spindle is stopped, and make sure that a signal for one rotation of the spindle is generated at the alignment position. After releasing the engagement between the thread cutting tool or grindstone and the workpiece, set the spindle at a steady state. The rotational speed of the spindle is detected by the pulses generated every time the spindle rotates at a predetermined angle, and the amount of delay of the thread cutting crab tool or workpiece is predicted from the detected speed, and the synchronization difference caused by the amount of delay is corrected. The shift amount of the one-rotation signal generation position for correction is determined, the one-rotation signal generation position is shifted by the determined shift amount, and the reprocessing or grinding is performed based on the detection of the one-time transmission signal of the hind leg. Characteristic numerical control method. (3) Correct the position of the thread cutting tool in the case of thread cutting reprocessing, or the workpiece position in the case of gear 111 machining or grinding, by the difference between the predicted delay amount and the actual delay amount. A number f direct control method according to claim (2).