JP2695537B2 - Running material cutting method in numerical controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention automatically cuts a continuous material fed from a material feeder to a predetermined length by a cutting means which reciprocates in a running direction of the material without stopping. The present invention relates to a running material cutting method in a numerical controller.

[0002]

2. Description of the Related Art Conventionally, when a continuous material traveling at a constant speed along a predetermined line is cut to a predetermined length without stopping, a cutter body which reciprocates in a traveling direction of the material is provided. A traveling material cutting method is generally used in which the position of a cutter attached to a main body is adjusted to a position having a predetermined length and the speed is adjusted to the speed of the material to cut the material by the cutter. FIG. 5 is a block diagram showing an example of a numerical controller for realizing a conventional running material cutting method. The part program analysis unit 21 stores a part program PP as shown below which is stored in advance in the part program storage unit 16. Read and analyze. N001GOOX ₀ running cut positioning N002G79X ₁ LcQc running cut fixed cycle to a fixed cycle start position Incidentally, _{X 1} is the target value, Lc is the cut length, Qc is the command of the number of repetitions.

The part program analysis unit 21 sets a cutting length command Lc in the cutting length storage unit 22, and sets a repeat count command Qc in the repeat count designating storage unit 23. The cutting length storage unit 22 converts the set cutting length Lc into the number of pulses Lp. In the gate G2, when the count value SC from the repeat counter control unit 19 is 0, that is, in the first cutting cycle, the cutting operation start command SCM from the part program analysis unit 21 is sent via the gate G4 to the cutting start counter storage unit. Send to 17. The pulse counter 12 reads the pulse PS of the pulse generator PG operated by the traveling movement of the material 2 and sets it as Fp to set the cutting start counter storage unit 17
To send to. The disconnection start counter storage unit 17 has a gate G4.
When the cutting operation start command SCM is received from, Fp sent from the pulse counter 12 is set in PCOUNT, and the function generator 18 operates the cutting cycle. The function generator 18 drives the cutter body 4 based on the pulse PS of the pulse generator PG with respect to the target value X ₁ and the motor driver 1
1, driven by the drive motor 10 and the cutter body feed drive mechanism 9.

Further, the speed of the cutter body 4 obtained by the position detector 7 attached to the drive motor 10;
Material 2 obtained by pulse PS of pulse generator PG
The speeds are compared by the speed comparator 15, and if the two speeds match, the cutting command SSC is sent to the cutting control unit 8 and the material 2 is cut by the cutter in the cutter body 4. Function generator 1
8 confirms whether or not the cutting completion signal SCED is inputted from the cutting control unit 8, and when the cutting completion signal SCED is inputted, the cutter body 4 is moved to a predetermined position by the drive motor drive unit 11, the drive motor 10 and the cutter body feed drive mechanism 9. At the same time as returning to the position, the function generation end signal SFE is repeatedly sent to the counter control section 19 to increment the count value SC. The number-of-repetitions comparison unit 20 stores the count value SC of the repetition counter control unit 19 and the number-of-repetitions designation storage unit 23
When the count value SC is equal to the command Rc of the number of repetitions, all the processing is ended.

On the other hand, when the count value SC is less than the command Rc of the number of repetitions, it is not the first cutting cycle, so the adder 13 stores the cutting length Lp and the cutting start counter stored in the cutting length storage unit 22. The pulse counter 12 stored in the section 17 and stored in the previous cutting cycle
Value of PCOUNT is added. The pulse counter 12 reads the pulse PS of the pulse generator PG, sets it as Fp, and sends it to the comparator 14. Comparator 14 is adder 1
The added value from 3 is compared with the value Fp of the pulse counter 12, and when Fp ≧ PCOUNT + Lp, the gate G3
To open the cutting start counter storage unit 1 via the gate G4.
7 Then, after that, when the start of the cutting cycle is controlled by the gate G3, the same cutting cycle as described above is continued, and the cutting cycle is ended when the cutting cycle reaches the specified number of times or more.

Here, a supplementary explanation of the process of controlling the cutter body 4 based on the pulse of the pulse generator 5 with respect to the target value X ₁ of the function generator 18 in the numerical controller for realizing the conventional method will be given with reference to FIG. To do. FIG. 6 shows the calculation unit amount for controlling the cutter body 4 by the sampling control cycle SPn for sampling the count value of the pulse of the pulse generator 5. The point at which the pulse of the pulse generator 5 operating by the traveling movement of the material 2 reaches the cutting length Lp is P1, but since it is recognized in the sampling control cycle SP1, the material 2 has already advanced to the position of the point P2. Will be out. Therefore, the calculation operation is started by using the travel length ΔP1 as the movement amount of the cutter body 4, and the travel length ΔP2 of the material 2 obtained by the pulse of the pulse generator 5 counted between the sampling control cycles in the subsequent sampling control cycle. , ΔP3, ..., ΔPn are used as the movement amount of the cutter body 4 to perform the calculation operation.

[0007]

According to the traveling material cutting method in the above-described conventional numerical control device, the start operation of the cutting cycle and the arithmetic operation of the cutter body in the cutting cycle generate the pulse generated by the traveling movement of the material. It is controlled based on the pulse count value of the vessel. Therefore, it is based on the pulse count value that it is determined that the traveling movement of the material has reached the cutting length Lp, so that the start position of the cutting cycle may generate an error of one pulse of the pulse count value. When operating read operation for example, the output pulse of the pulse generator shown in FIG. 7 at the sampling control cycle, pulse pulse count value is generated after the traveling movement of the material has reached the cutting length Lp a pulse exceeding Fp _n That is, in the sampling control cycle SP1, it is performed by the pulse after Fp _{n + 1} , and the moving amount thereof indicates ΔP1. However, since the traveling movement of the material actually reaches the cutting length Lp at the point P1 ′, the position where the cutting cycle is started starts with an error of ΔΔP1, and this error is equal to the error of the cutting length of the material. turn into.

The figure (a) shows the calculated movement amount of the cutter body in the conventional method, and the figure (b) shows the ideal calculated movement amount of the cutter body. For example, pulse generator 1
1024 pulses per revolution, one revolution of the pulse generator with the traveling amount of material 40πmm, traveling speed of material 12 m / min,
If the sampling control period is 5 ms, the pulse generator 1
The amount of material movement for the pulse is about 0.123 mm, the number of pulses generated during the sampling control period is about 8.15, and the error is 0.123 mm because the error is one pulse at maximum. Further, since the number of pulses generated in one sampling control cycle is 8.15, the count value of the pulse of the pulse generator shows 8 to 9 pulses, and the calculated movement amount of the cutter body is 0.984 mm (for 8 pulses). From 1.10
There was a drawback that the calculation speed was 7 mm (for 9 pulses) and the calculation speed was not constant.

As a method of solving this problem, the error can be reduced by increasing the number of pulses per one rotation of the pulse generator, but the pulse generator having the increased number of pulses is expensive. was there. Also,
As another method, the error can be reduced by reducing the traveling movement amount of the material per one rotation of the pulse generator, but since the pulse generator is generally rotated in non-slip contact with the material, There is a problem that there is a limit to reducing the movement amount per rotation. The present invention has been made under the circumstances described above, and the object of the present invention is to
It is an object of the present invention to provide a running material cutting method in a numerical control device capable of reducing a judgment error of a cutting cycle start position and obtaining a stable material cutting length.

[0010]

According to the present invention, there is provided cutting means for reciprocating in the traveling direction of the material by reading the count value of the pulse generated by the continuous traveling movement of the material delivered at a constant speed. The present invention relates to a traveling material cutting method in a numerical control device that controls the relative speed between the cutting means and the material while controlling the speed of the cutting means and automatically cuts the material into a predetermined length without stopping the material. The object of the present invention is to calculate the number of decimals when converting the predetermined length into the count value of the pulse as the traveling amount of the material, and read it by sampling control having a constant period. The count value of the free running counter that counts up in a predetermined cycle and the count of the free running counter when the pulse is input. A value obtained by correcting the count value of the pulse read by the sampling control based on the count value of the interpolation reference counter that stores the count value and converting the corrected pulse count value and the predetermined length into a pulse count value. The cutting cycle start position is determined based on the above, and the feed unit amount of the cutting means for each sampling control cycle is calculated based on the corrected pulse count value.

[0011]

According to the present invention, the feed unit amount of the cutter body is calculated by processing the count value of the feed pulse counter indicating the running length of the material to the right of the decimal point. It is smaller than the minute and stable cutting can be performed.

[0012]

FIG. 1 is a block diagram showing an example of a numerical controller for realizing the running material cutting method of the present invention, corresponding to FIG. 5, and the same components are designated by the same reference numerals and the description thereof will be omitted. Further, FIG. 2 is a flowchart for explaining an operation example of its main part. The interpolation reference counter 32 stores the count FRp of the free running counter 31 by the input of the pulse Ps of the pulse generator 5, and when the storage is completed, the count value FRp of the free running counter 31 is cleared. The calculator 33 reads the pulse Fp of the pulse counter 12 for each sampling control cycle (step S
1), the count value FRp of the free running counter 31 and the count value FMp of the interpolation reference counter 32
Is read (steps S2 and S3), and the calculation process {Fp +
(FRp / FMp)} is performed (step S4), and the count value Fp 'of the correction process obtained as a result is output.
This count value Fp 'is sent to the cutting start counter storage unit 17 that specifies the start time of the cutting cycle or the function generating unit 18 that operates the cutting cycle, and thereafter the same cutting cycle control as in the conventional case is performed.

The operation of the free running counter 31 and the interpolation reference counter 32 will be supplemented with reference to FIG. The free-running counter 31 is a counter that counts up the count value FRp at a constant speed by an internal clock and is cleared each time the interpolation reference counter 32 stores the count value FRp of the free-running counter 31, and the speed is a pulse counter. It is faster than the count speed of 12. Interpolation reference counter 32 is a counter for storing a count value FMp _n by pulse Ps input from the pulse generator 5 a count value FRp of the free running counter 31. Count value Fp _n of the pulse counter 12 when the sampling control with a sampling control period SPn, interpolation reference counter 32
Of the count value FMp _n, free-running counter 31
Count FRp _n of which indicates that is read.
Therefore, the count value of the interpolation reference counter 32 indicates the time of the pulse interval of the pulse generator 5, and the count value of the free running counter 31 changes from the generation of the pulse of the pulse generator 5 immediately before the sampling control is started to the sampling control. The time until the start is shown, and when converted into the pulse number of the pulse counter 12, it becomes FRp / FMp pulse. Therefore, the count value of the pulse counter 12 during sampling control is Fp + (FRp / FMp). Therefore, by setting the count value of the pulse counter 12 used at the time of sampling control to Fp + (FRp / FMp), an accurate count value obtained up to the value below the decimal point is used, and therefore, when starting the cutting cycle. The position can be controlled accurately.

For example, as in the prior art, the pulse generator 1 rotation makes 1024 pulses, the material traveling amount 40 pi mm makes one pulse generator rotation, the material traveling speed 12 m / min) Sampling control period 5 ms, and the interpolation pulse period Is 10πs, the count value FMp of the interpolation reference counter is about 61 pulses, and it is sufficient to process one byte below the decimal point. Therefore, free running counter 1
The error for the pulse is about 0.002 mm. In this way, the count value of the pulse counter 12 is processed as a count value below the decimal point, and the cutting length set by the cutting length setting means is converted to the count value of the pulse counter 12 up to the decimal point and below the decimal point. If determination count value of the comparison, the variation of the calculation of the feed unit of the cutter body 4 significantly that when the can Ru reduce both sampling control every cycle error in the position at the start of cutting cycle be reduced it can. In the calculation of the cutter body 4 by the conventional sampling control, the reading pulse causes a variation of one pulse for each sampling control as shown by the dotted line in FIG. 4, so that the moving speed of the cutter body 4 is not stable, but the sampling control is performed in the present invention. Since the value below the decimal point is taken when reading the count value by, the error of the read count value for each sampling control is reduced as shown by the solid line in the figure, and the cutter body 4 is controlled at a stable calculation speed. can do.

[0015]

As described above, according to the running material cutting method in the numerical controller of the present invention, a material having a high cutting length can always be stably obtained, so that the number of processing steps thereafter can be reduced. Therefore, the processing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a numerical control device for realizing a running material cutting method according to the present invention.

FIG. 2 is a flowchart for explaining the method of the present invention.

FIG. 3 is a time chart for explaining the method of the present invention.

FIG. 4 is a time chart for comparing the method of the present invention with a conventional method.

FIG. 5 is a block diagram showing an example of a numerical control device that realizes a conventional running material cutting method.

FIG. 6 is a time chart for explaining a conventional method.

FIG. 7 is a time chart for explaining problems in the conventional method.

[Explanation of symbols]

 31 Free-Running Counter 32 Interpolation Reference Counter 33 Computing Unit

Claims (1)

(57) [Claims] 1. A cutting means for reciprocally moving in the traveling direction of the material by reading the count value of pulses generated by the traveling movement of the continuous material sent at a constant speed, and controlling the speed of the cutting means. When the relative position between the cutting means and the material is controlled and the material is automatically cut into a predetermined length without being stopped, the pulse length is the count value of the pulse with the predetermined length as the travel distance of the material. The free running counter is counted when the pulse is input and the count value of the free running counter that counts up at a predetermined cycle read by sampling control with a constant cycle when calculating Based on the count value of the interpolation reference counter that stores the count value of The cutting cycle start position based on the corrected pulse count value and a value obtained by converting the corrected pulse count value into the pulse count value, and based on the corrected pulse count value. A method of cutting a traveling material in a numerical control device, characterized in that a feed unit amount of the cutting means is calculated for each sampling control cycle.