JPS59117474A - Speed controller for industrial machine such as crane or the like - Google Patents

Abstract

PURPOSE:To improve the deterioration of a low speed starting characteristic and inching characteristic due to soft starting property by combining a speed command applied with soft starting property with a signal in response to the quantity of variation of the operating amount of a controller as a speed command. CONSTITUTION:The output signal of a controller is inputted to a differentiator 6 and an integrator 7. The differentiator 6 differentiates the rise and fall of this signal, and the integrator 7 integrates the signal to provide soft starting property and cushion starting property. An operational amplifier 10 adds the outputs of the differentiator 6 and the integrator 7, and outputs as a speed command. A speed control amplifier 13 applies a deviation between the speed command and the speed signal detected by a tachometer generator 11 to a phase controller 14.

Description

[Detailed Description of the Invention] The present invention relates to a speed control device for various weight movements such as turning, traveling, and traversing in cranes and other face and corner machines, and concerns deterioration of low-speed starting characteristics and inching characteristics when equipped with a soft start function. It is designed to prevent this.

When operating a crane, if the operating amount of the controller's knob 1 is given as the speed command for one of the drive motors, it will cause sudden notches (sharply operating the 1/1 handle) and reverse notches (reverse rotation without stopping). When operating the machine, it may put strain on the machine and cause it to malfunction. It's also dangerous because the hanging baggage shakes a lot.

Therefore, regardless of sudden operation of the controller, the
So-called soft starts and cushion stops are being considered, which slow down operations such as stopping and reversing (7:l). Conventional soft start and cushion stop are performed by integrating the amount of controller operation, as shown in Figure 1.
It was used as a speed command for the drive motor. However, with such a device, the rise of the speed command is gradual, so
When controlling by inching (steps) as shown in FIG. 2, there is a drawback that the speed command does not increase sufficiently and the followability of the motor deteriorates.

This invention has been made based on the above-mentioned points, and provides a speed side control device for industrial machinery such as a crane, which prevents deterioration of low-speed starting characteristics and inching characteristics when equipped with a soft start function. This is what I am trying to do.

According to this invention, the speed command with the soft start characteristic is adjusted to 1 g@
The above objective was achieved by synthesizing .

Hereinafter, an embodiment of the present invention will be described with reference to an imaginary diagram 1m.

In the AA diagram, three-phase alternating current pressure is supplied from the power lines lu, lv, and 1w, and -? Then, the voltage it;
It is supplied to the drive motor 3 for turning, traveling, traversing, etc.).

The controller 4 commands the moving direction and moving speed of the object by operating the handle 5. Here, it can be operated in 5 stages: O notch (1'i' stop), +1 non-notch (forward rotation, low speed), +2 notch (forward rotation, wide speed), -1 notch (reverse rotation, slow speed), and -2 notch (reverse rotation related). It looks like this. The controller 4 outputs a signal whose polarity and magnitude correspond to the operation method and number of operations.

The output signal of the controller 4 is input to a differentiating circuit 6 and an integrating circuit 7, respectively. The integrating circuit 7 integrates this signal, smoothes its rise and fall, and provides soft start, cushion stop characteristics. 1, the differentiating circuit 6 differentiates the rising and falling edges of this signal.

The outputs of the differentiating circuit 6 and the integrating circuit 7 are adjusted in level with a volume 8.9, and then added with an operational amplifier 10.
It is numbed and output as a speed command.

FIG. 4 shows the molding of each of the above parts.

The output of the operational amplifier lO obtained at the final time as a speed command is the fa component output superimposed on the rise and fall of the integral output, so it is possible to improve the poor followability at startup due to the soft start characteristic. can. Furthermore, since the copy signal is superimposed at the beginning of the valley notch operation of the controller 4, as shown in FIG. can get.

In Fig. 3, the speed of motor 3 is equal to the speed of tacho generator 1.
1 is detected. In the sword II calculation point 12, the deviation between the speed command value and the speed detection value is calculated. This deviation signal is speed city 0
#Input to the phase control circuit 14 via the amplifier 13.

The magnitude and polarity of the output signal of the speed increase control circuit 13 indicates the magnitude of the torque and the direction of rotation of the motor 3. An ignition pulse is created with a phase that corresponds to the magnitude of the output signal of the controller 13.The torque direction detection circuit 15
The direction in which the motor 3 should rotate is detected based on the polarity of the output signal of the phase shifter 13, and forward/reverse switching logic is used so that the output of the phase shift circuit 14 traces the thyristor in the appropriate phase rotation direction. make it work.

When the speed of the motor 3 detected by the tachogenerator becomes smaller than a preset value, the comparator 9 causes the forward/reverse switching logic 16 to switch to the current state.
Ru. As a result, even if the reverse notch is turned on, switching of the drive direction of the motor 3 is prevented when the speed drops below the set value.
The yoke caused by the slippage in the driving direction is loosened. In addition,
It is adjusted by the speed setting (IN is volume 2).

Additionally, a timer is also used to prevent shocks caused by reverse notches. That is, the -+0 operation detection circuit 2 detects that the masonry controller 4 has been operated from - (reverse) to 0 (stop), drives the timer, and sets the comparator to the switch 24 for a certain period of time. By turning off the output of , the switch is prevented from switching to the + (forward rotation) direction. When the operation is detected, the timer 26 is driven, and the output of the converter 20 is turned off for a certain period of time by the switch thorn, thereby preventing switching in the - (reverse) direction.Timer 23 , 26 are adjusted by volume controllers 29, respectively.

If the tacho generator 1 is not installed,
Point 1lbIj! As shown by the addition, the speed command value may be used instead of the speed detection value L).

Further, as a measure to prevent shock caused by the brake, in this embodiment, similarly to the forward/reverse switching described above, the brake is not applied unless the speed of the motor 3 falls below a certain value. That is, the brake relay 31 is turned on only when the output of the comparator reaches %ll, and the brake 3
2 is now ready to be created. However, if you perform a reverse notch operation, you can simply reverse the position by 1 without applying the brake 32, so 0 non-touch (4+stop) is detected by the 0 notch detection circuit.
Only when an operation is detected, the AND circuit 34 is turned on and the brake 32 is applied.

In the above embodiment, the invention of C is applied to a crane, but the present invention is not limited to this and can be applied to other industrial machines having soft start characteristics.

As explained above, according to the present invention, a signal corresponding to the amount of change in the operation amount of the controller is synthesized with the speed command given the soft start characteristic, so that a large signal is generated at the rising edge of the speed command. As a result, it is possible to improve the deterioration of low-speed starting characteristics and inching characteristics caused by soft start characteristics.

Explanation of the inner surface quantity rate Figure 1 is a waveform diagram showing conventional soft start characteristics, Figure 2 is a waveform diagram showing conventional soft start characteristics.
The figure shows the inching characteristic when using the soft start characteristic shown in Fig. 1. The third part is a block diagram showing an embodiment of the present invention, and the fourth part shows each part of the circuit shown in Fig. 3. The fifth figure is a waveform diagram showing the operation of the circuit shown in FIG.

Iu, Iv, 1w...power line, 2...-thyristor circuit for voltage control and phase switching, 3...groove +
Motivation, 4... Controller, 6... Differential circuit, 7
...Integrator circuit, 31...Brake relay, 32.
··brake.

Claims (1)

[Claims] a controller that outputs a signal according to the amount of operation of the controller; a first circuit that outputs the output signal of the controller with a slow change; and a first circuit that outputs a signal that corresponds to the amount of change in the output signal of the controller. Speed of an industrial machine such as a crane, which is equipped with a circuit of 2 and a means for synthesizing the output signals of the first circuit and the second circuit of MiJ and outputting it as a speed command for a side control object. #tl device.