JPH04112698A - Inverter device for synchronized operation - Google Patents

Abstract

PURPOSE:To automatically set the output frequency of an inverter device in case of performing synchronized operation by equipping it with an inverter part, which converts DC input into AC and outputs it, and a control means, which controls the output frequency of the inverter. CONSTITUTION:First, by setting the input of a synchronized operation signal by a setter 16, the automatic calculation mode of output frequency fA is selected. Next, the acceleration and deceleration times in case of processing a work are set in inverter devices 2 and 3, respectively. Next, the certain constant velocity revolution No of the work is selected, and selected No is set in the inverter devices 2 and 3. Next, the calculation formula stored in ROM 30 is executed by CPU 17, and it performs the automatic calculation of the output frequency of fA of the inverter device 2. Furthermore, the output frequency fA is automatically set to an output frequency seller 26 by the command of CPU 17. Next, the output frequency fB of the inverter device 3 is automatically set. When the inverter devices 2 and 3 are controlled according to the above operation, two driving motors 4 and 5 becomes synchronized operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] This invention processes a star-shaped workpiece using a pair of drive motors via a speed change mechanism. The present invention relates to an inverter device for synchronous operation of the drive motor in the above case.

[Prior Art 1] A machine tool may have two or more drive motors, each of which is driven and controlled by an independent inverter device, and each performs a different machining operation. On the other hand, in order to increase the machining speed, two drive motors are sometimes mechanically coupled and machining operations are performed while operating synchronously.

FIGS. 4 and 5 are configuration diagrams showing a drive section of a conventional machine tool. Section 4 shows an example in which different machining operations are performed, and Fig. 5 shows an example in which processing operations are performed in synchronized operation. In Fig. 3, (R), fsl, and (T) are three-phase AC power , fzl and t31 each indicate a t inverter device. f4) and is) indicate a three-phase induction motor (hereinafter referred to as "drive motor") for driving the ball shaft.

f6), +71 indicates the transmission mechanism, which is composed of a breech and a belt. Transmission mechanism (6), (7)
Since the workpieces of each drive motor are different, the speed ratio is set to an optimum value according to the workpiece. Therefore, the speed change ratios of the speed change mechanisms (6) and (7) are generally different.

Here, the gear ratios of the transmission mechanisms (6) and (7) are set to TA and T, respectively.
ll. (81 and () are chucks that grip the workpieces, which are connected to the outputs of the transmission mechanisms (6) and (7), respectively. (10) and (11) are the workpieces that serve as loads.

FIG. 6 is a configuration diagram showing a conventional inverter device, and FIG. 7 is a curve diagram showing acceleration time and deceleration time. In the figure (
11) is a forward converter that converts alternating current to direct current, +121
is an inverse converter that converts direct current to alternating current, (13) is 111p
This is a capacitor that smoothes the output voltage of the converter (11). (14) is a drive circuit that drives the inverter (12), (I5) is a control (pulmonary part) that controls the drive circuit (14), and (16) is an input means for setting the operating conditions of the inverter device. (17) is a calculation means that generates a drive command to the drive circuit (14), and is an example of the setting device CPtJ.
(25) This is a memory having a RAM function.

(20) is the same Il! for drive motors (4) and (5). When processing a workpiece (I[]l) by Jl operation, this is a synchronization signal storage unit that stores an input synchronization signal. (21)
are acceleration time storage units that store acceleration times when the drive motors (4) are operated independently. (22) is a deceleration time storage section that similarly stores deceleration time.

(23) is an acceleration time storage section that stores the acceleration time of the drive motor (4) in the case of synchronous operation. (24) is a deceleration time storage section that similarly stores deceleration time.

(25) is an output frequency storage unit that stores the output frequency of the inverter device. In FIG. 7, tA indicates acceleration time, and t@ indicates deceleration time.

Next, the operation will be explained. First, a case will be described in which the drive motors (4) and (5) each independently process a workpiece. In such a case, the attained frequency f1, acceleration and deceleration times of the inverter devices f2) and f3) are set to optimal values in consideration of the processing speed of each workpiece and the speed change mechanisms fG) and '+71.

Next, a case will be described in which the drive motors (4) and (5) operate synchronously to process a workpiece. When darning, the optimum value of the rotation speed of the workpiece is determined by taking into consideration the processing method of the workpiece. Now, the rotation speed of the workpiece is N. Then, the rotational speeds of drive motors (4) and (5) are N, , N, respectively.
, the gear ratio is T,,T.

Then, the following formula is obtained.

No = NAXTA = Nm Become.

NA=120 fa/Pa=No/Ta f
rpm-(21Na”120 fs/pH=
No /Ts (rpml fl Therefore, the output frequency of each inverter is as follows.

FA=JJoPa/120 TAf4+f, =N,
P, /120 Ta +5+ Now, if the rotation speed of the workpiece is set to No and the processing is performed, the output frequency of the inverter device is calculated as (fa,
I was looking for fs. Furthermore, in order to achieve synchronous operation, it is necessary to equalize the acceleration and deceleration times of the drive motors f4) and +5i.

Note that the acceleration time here refers to the time required for the output frequency of the inverter devices (4) and (5) to reach fA or fll from zero. Furthermore, the deceleration time refers to the time it takes for the output frequency to reach zero from fl or f.

The above output frequency fA acceleration and deceleration time were set in the inverter device using the following procedure.

Although only the inverter device A (2) will be explained, the settings of the inverter device B (3) are also similar. The worker
The setting device (16) is operated to manually input the synchronous operation signal to High in the synchronous signal storage section (20) in the memory (18). Furthermore, the acceleration time is set in the acceleration time storage section (23) by a similar operation. Also, the deceleration time is set in the deceleration time storage section (24). Similarly, the output frequency f is set in the output frequency storage section (25).

[Problems to be Solved by the Invention] Since the conventional inverter device is configured as described above, when performing synchronous operation, the operator needs to calculate the output frequency of the inverter device using a desired calculation formula. There was a problem that the calculation was complicated.

The present invention has been made to solve such problems, and an object of the present invention is to provide an inverter section that can automatically set the output frequency of the inverter device when performing synchronous operation.

[Means for Solving the Problems] An inverter device for synchronous operation according to the present invention includes an inverter unit that converts DC input into AC and outputs it, and a control unit that controls the output frequency of the inverter unit,
In an inverter device for synchronous operation that synchronously controls a pair of drive motors that respectively drive a single driven object via a mechanical conversion device.

The control means includes an input means for inputting an input for commanding synchronous operation, a desired rotational speed of the driven object, an acceleration time to reach the desired rotational speed, and at least one of a deceleration time for the opposite; a first storage means for storing the data of the driven object; a calculation means for calculating an output frequency of the inverter section corresponding to a desired rotational speed of the driven object based on the first storage means; It has a second storage means for temporarily storing information about the inverter section based on the calculation result stored in the second storage means and the acceleration time or deceleration time stored in the first storage means. It controls the output frequency.

1 Effect] The inverter device for synchronous operation configured as described above automatically calculates the output frequency of the inverter section by setting the desired rotation speed, acceleration time, and deceleration time of the driven object, and calculates the output frequency of the inverter section based on the calculation result. .

Controls the output frequency of the inverter section.

[Embodiment 1 of the Invention Figure 1 is a block diagram showing an embodiment of the present invention.
11) to [18), (201 to (25) indicate the same or equivalent parts as before. (30) indicates the read-only memory (
ROM), and has an output frequency f1
Memorize the formula below.

fA = KA No (61 Here, K, = P, /120 TA Note that the above explanation was about inverter device A (2), but the storage contents in the first storage means of inverter device B (3) are as follows. .

f,=, No m where □=P@/120 Ta (26) is a second storage means that temporarily stores the calculation result of the output frequency fA or f8.

Next, the operation will be explained based on the flowchart of FIG. Now, in order to carry out machining work by synchronous operation, both ends of the workpiece (lO) are gripped by chucks (8) and (9), respectively, and the drive motors f4) and (51) are mechanically coupled.

First, in step (50), the input of the synchronous operation number A is set by the setting device (16). As a result, the process proceeds to the next step and the automatic calculation mode of the output frequency fA is selected. Next, in step (51), the acceleration and deceleration times for machining the workpiece are set to inverter units Rf2) and (3+, respectively) using the setter (16).In step (52), the constant speed of the workpiece is The rotational speed N. is selected and the selected N. is selected for each of the inverter devices f21, +] using the setting device (16).

By the operations in steps f51) and f52), the desired acceleration/deceleration of the workpiece is determined! (X axis - time, Y axis - rotational speed N of the workpiece) is obtained. Step (531
Then, the calculation formula fA=No stored in ROM (301)
KA is executed by the CPU (17) to automatically calculate the output frequency f1 of the inverter device (2). Further, in step (54), the output frequency f1 obtained in step (53) is automatically set in the output frequency setting section (26) by the instruction of the CPU (17).

Steps (55) and (56) are inverter installed! B(3+
These steps correspond to steps (53) and (54), respectively, to automatically set the output frequency f8. The inverter device [21,
When (3) is controlled, the two drive motors (4) and (5) become synchronously operated. Therefore, the workpiece (lO) is processed by the drive motors f4) and f51. In the above embodiment, the inverter device +2)
, +3+ output frequencies fA, f are calculated and automatically set based on individual calculation formulas, but the present invention is not limited to this. For example, the output frequency f8 may be calculated and automatically set based on the result of the output frequency fA. Now, if we transform the fli formula, we get the following formula.

fATA/P, ='l Ts/P, (8) f
B=fAK, (91 Here, Kc=TA/TBPA Formula (9) is stored in the ROM (30) of the inverter device (3). Similarly, the ROM (30) of the inverter device (2)
30) stores the formula (1).

The operation will be explained below based on the flowchart shown in FIG.

The same reference numerals as in Figure 2 of the section indicate the same or equivalent parts. Therefore, in step (57), the inverter B
This is the step of calculating 9'I of the output frequency f in (3). Such calculations are performed on CPU f17) and ROM +3
01.

[Effects of the Invention 1] The present invention can be applied to any number of rotations N of the workpiece. and the gear ratio T- of the machine tool, the number of poles P of the Tm drive motor.

The output frequency fAf of the inverter device considering Pll,
The desired calculation formula for determining There is no need to calculate the output frequency, and there is an effect of preventing mistakes in setting the inverter device due to miscalculations.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an inverter device for synchronous operation showing an embodiment of the present invention, and FIGS. 2 and 3 are flowcharts showing an embodiment of the invention. FIG. 6 is a configuration diagram showing a drive unit of a machine tool, FIG. 6 is a configuration diagram showing a conventional inverter device for synchronous operation, and FIG. 7 is a curve diagram showing conventional acceleration time and deceleration time. In the figure, +2+,
+3+ is the inverter device, (41, +5+ is the drive motor fG), +7+ is the transmission mechanism (10+ is the workpiece f16), the setting device (17) is the input means, and the calculation means is C P Ll ('18 ) 20th) RAM, which is a storage means; (26) is a storage unit (30) that stores the calculation result of the output frequency of the inverter unit;
Show the means. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] A pair of drive motors are provided with an inverter section that converts DC input into alternating current and output, and a control means that controls the output frequency of the inverter section, and that drive a single drive target via a mechanical converter, respectively. In the inverter device for synchronous operation that performs synchronous control, the control means controls at least any of an input for commanding synchronous operation, a desired rotational speed of the driven object, an acceleration time to reach the desired rotational speed, and a deceleration time for the opposite. an input means for inputting the input data, a first storage means for storing the input data, and an output frequency of the inverter section corresponding to a desired rotational speed of the driven object is calculated based on the first storage means. comprising a calculation means and a second storage means for temporarily storing the result of the calculation means;
An inverter device for synchronous operation that controls an output frequency of the inverter section based on the calculation result stored in the storage means and the acceleration time or deceleration time stored in the first storage means.