JPH11268885A - Crane traveling device and inverter for crane traveling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To re-accelerate or reverse a crane from the operating speed or stop it at a prescribed position quickly and easily by providing a speed detecting means. SOLUTION: This speed detecting means has a speed sensor constituted of a pulse generator and a pulse encoder. The speed sensor outputs the pulse signal proportional to the revolving speed, and a speed operation section 17 generates a speed signal ωr. A command signal is sent to an acceleration/ deceleration computing unit 5, the difference between the command signal and the speed signal ωr is calculated by a subtracter 8, and it is proportionally integrated or proportionally amplified by an error controller 9. The speed signal ωr is sent to a current controller and a pulse width modulation(PWM) inverter section 19 via a magnetic flux controller 18. The output of a torque controller 10 is fed to a slip angle computing unit 15, the slide angular frequency ωs of a traveling motor 1 is calculated, and the output angular frequency ω1 is fed to a current controller and the PWM inverter section 19. The speed of the traveling motor 1 is controlled by pulse width modulation control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane traveling device and an inverter for a crane traveling device, and more particularly to a crane traveling device capable of smoothly accelerating, decelerating, and stopping and an inverter device for a crane traveling device as a control device thereof. It is about.

[0002]

2. Description of the Related Art In a crane traveling machine operated by an operator (hereinafter referred to as an operator) on a crane, a traveling motor can (1) easily change its speed. (2) By setting the acceleration / deceleration time, smooth acceleration / deceleration can be performed automatically. (3) High efficiency operation is possible. (4) Maintenance-free. Such is desired.

[0003] In recent years, the speed control of the traveling motor has been based on a crane control method based on the secondary resistance control of the winding type motor, and the relationship between the output voltage V and the output frequency F (V / F) has been determined in advance. (V / F inverter) that controls the induction motor so as to control the induction motor to a variable speed by using a so-called V / F inverter. Conventionally, the crane traveling motor (coasting operation) in this inverter-driven crane traveling motor is used.
At that time, the output of the inverter was shut off and the vehicle was operating in a free-run state. FIG. 13 shows a time chart of this operation. In FIG. 13, the horizontal axis represents time, and the vertical axis represents traveling crane speed, and shows a case where the vehicle is stopped at the target position from the speed N1 state. The solid line indicates the actual speed, and the two-dot chain line indicates the speed command of the acceleration / deceleration calculation unit. The section indicated by A indicates a section where deceleration is performed by the foot brake, and the section indicated by B indicates a coasting operation (coasting operation; simple free-run deceleration).

[0004] In a traveling motor of a crane with an inverter, when decelerating, an operator operates with a foot,
That is, in order to decelerate by applying the foot brake,
When the inverter is in operation, the motor current increases,
The inverter trips (output cutoff) for the purpose of protecting itself, so the crane stops. In the worst case, the main circuit element of the inverter will be damaged. For this reason, when decelerating, the output of the inverter is cut off and the vehicle is decelerated in a free-run state, that is, in a coasting operation (coasting operation).

If the crane does not reach the target stop position, the crane is accelerated again from the coasting operation. If the vehicle has gone too far, a reverse operation may be performed. There are several of these methods for loads other than cranes. For example, Japanese Patent Publication No. 4-24959 describes the case of an instantaneous power failure, but the coasting operation of the crane is not an instantaneous power failure compared to the case of the crane this time. Consider the same thing because it is driving. First, the rotation frequency induced from the residual voltage of the free running motor is detected. After the power is restored, the output frequency F given from the inverter is the detected frequency. The output voltage V of the inverter is gradually increased from near zero to a predetermined V / F
After ascending to the pattern, the operation is returned to the V / F operation based on the normal V / F pattern.

In Japanese Patent Application Laid-Open No. 50-88527, the presence or absence of the residual voltage of the motor is detected.
The output voltage was controlled so as to have the same phase, and when there was no output voltage, the output of the inverter was directly supplied to the motor. However, when there is no residual voltage, for crane traveling, the operator forcibly reduces the motor speed by operating the foot brake, and if the output frequency and voltage output until then are given, the actual speed will be reduced. The speed command does not match and the speed changes suddenly.

When the output frequency and voltage are given from zero,
As shown in FIG. 10 of the present application, since the so-called soft start in which the speed is once suddenly reduced to zero and then gradually accelerated is performed, the luggage suspended by the crane may shake greatly. As described above, in the conventional inverter for traveling a crane, the deceleration, the re-acceleration, and the reversing operation from the running speed are not smoothly performed.

Further, as described in the conventional example of Japanese Patent Application Laid-Open No. 50-88527, when the phase and frequency of the residual voltage of the motor do not match, the elements constituting the inverter and the motor are adversely affected. Therefore, although not described here, the example most commonly implemented as a crane traveling inverter is that even if it cannot be stopped at the target position, do not re-accelerate until the motor stops reliably, Or it was not allowed to be in the reverse operation. In this case, since the operator is on the crane, it is sufficiently known whether or not the crane (motor) has stopped, and the user has to restart until he stops. In other words, the operation is stopped once, and then stopped while finely adjusting the target position again.

[0009]

Problems to be solved by the present invention are as follows.

1) When the traveling crane is likely to stop in front of the target position while decelerating during coasting while the operator operates or releases the foot brake,
The motor does not always stop and then re-accelerate, and even if it overshoots, it does not stop and then reverses, but rather re-accelerates or reverses from the current driving speed, and quickly responds to it. And easily stop at the target position according to the operator's will.

2) When the motor for traveling is operated, acceleration, deceleration,
During reverse operation, the acceleration / deceleration torque of the inverter should be adjustable, and the acceleration or deceleration should be smooth without significantly increasing the load swing.

3) Responsiveness is 10 times or more that of the V / F inverter, and is responsive. Improving responsiveness allows the operator to absorb load fluctuations by acceleration / deceleration operations. Conventionally, V /
The responsivity of the F inverter is about 1 Hz, which means that the responsivity can be realized ten times or more. (In order to improve the responsiveness, of course, the frequency and the phase should be matched, but until now the phase suddenly changed near the zero crossing, and it was not possible to turn it on again while measuring the zero crossing point. However, it was not possible to cope with the case where the speed suddenly changed to the reverse direction.) An object of the present invention is to make it possible to cope with these without any problem.

The present invention is not a response to an instantaneous power failure, but a response to acceleration / deceleration operation of a traveling crane, and is usually performed by an operator during deceleration, re-acceleration, and reverse operation after coasting, which frequently occurs repeatedly. An object of the present invention is to provide a user-friendly crane traveling inverter that can be operated as desired.

[0014]

These objects are attained by the present invention as follows.

1) A speed detecting means is provided to enable rapid acceleration and reverse rotation as desired by the operator and to improve responsiveness.

2) In order to provide the above speed detecting means, the inverter is a vector control with a speed sensor, or the speed sensor is attached but the inverter is a sensorless vector control, and the speed detecting means by speed estimation calculation without using a speed sensor. It consists of an inverter that uses any of the provided speed sensorless vector controls.

3) At the time of coasting, foot brake operation or brake release, the current of the inverter is kept flowing without setting the output of the inverter to the free-run state, and the inverter is electrically connected to the motor, and the maximum torque of the motor is maintained. And the torque is limited by the first torque limit value.
Leave the power on.

4) After the coasting operation, at the time of re-acceleration or reverse rotation, a target speed command is set, and then the torque is limited by the second torque limit value. The operator can freely set the second limit value.

5) At the time of coasting, the inverter is in the first torque limiting state.

The inverter operates in a power running state regardless of whether the foot brake is on or off. -Or drive in the regenerative (brake) state.・ Furthermore, these can be switched so as to be in the regenerative state when the foot brake is on and the power running state when it is off.

[0021]

FIG. 1 shows an embodiment of the present invention. FIG. 1 shows a vector control configuration with a speed sensor. Reference numeral 1 denotes a crane traveling drive motor which is an induction motor. The output side of the traveling motor 1 is equipped with a foot brake 30 for applying a mechanical braking force. Reference numeral 2 denotes a speed sensor including a pulse generator for detecting speed, a pulse encoder, and the like, which is built in the motor or placed separately on a crane. The speed sensor outputs a pulse frequency proportional to the number of revolutions, and the speed calculation unit 17 obtains a speed signal ωr.

On the other hand, the traveling speed of the crane is controlled by a speed setting device 3-
1, 3, 2 and 3-3. In the figure, the three-stage speed is set, but the speed is not limited to three stages. This value may be set by a variable resistor,
A digital value may be set by a nonvolatile or volatile memory, a digital switch, or the like. The switches 4-1, 4-2, and 4-3 are not simultaneously selected by the speed switch. However, it is unavoidable that the instantaneous switch is turned on due to the delay of the switch-on time and the release time. This switch is labeled SF0, SF1, SF2 and is usually selected by a notch controller which switches the crane speed by the operator.

Next, the speed command is sent to the acceleration / deceleration calculator 5,
When the speed is switched, the maximum acceleration limit value is set so that the luggage does not shake, and the output of the acceleration / deceleration calculator 5 normally rises and falls with the inclination set to the maximum acceleration limit value. The inclination is set by the acceleration or deceleration time until reaching the target speed. The acceleration time and the deceleration time can be set separately.

The acceleration time and the deceleration time can be switched between a first acceleration / deceleration time 6-1 and a second acceleration / deceleration time 6-2 by an acceleration / deceleration time switch 7 (hereinafter referred to as CH1). The output of the acceleration / deceleration calculator 5 is subtracted by the subtractor 8 from the speed signal ωr, and is proportionally amplified or proportionally amplified by the error adjuster 9 to form a feedback loop.

The output of the error controller 9 is input to a torque limiter 10, which limits the output so as to limit the torque of the traveling motor. The limit value is a maximum torque value 13 determined by the maximum capacity of the inverter and the motor, and a first torque limit value 12 that can be adjusted from the outside.
-1 and a second torque limit value 12 that can be adjusted from the outside
-2. First torque limit value 12-1, second
The torque limit value 12-2 is enabled when the torque limit enable switch 14 operated from the outside is turned on, and one of the first and second torque limit values is selected by the torque limit value changeover switch 25 (hereinafter referred to as CH2). it can.

The output of the torque limiter 10 is sent to the current controller and the PWM inverter unit 19 as a torque current It for the running motor. On the other hand, the speed signal ωr output from the speed calculator 17 is input to the magnetic flux controller 18. The magnetic flux controller 18 performs an operation to make the traveling motor constant the magnetic flux in the constant torque region and make the magnetic flux inversely proportional to the rotation speed in the constant output region. The calculation result is sent to the current controller and the PWM inverter unit 19 as a magnetic flux component current Im. The output It of the torque limiter 10 is calculated by the slip angular frequency calculator 1
5, the slip angular frequency ωs of the traveling motor is calculated, and the adder 16 calculates the output angular frequency ω of the traveling motor.
1 = ωr + ωs is calculated. The output angular frequency ω1 of the adder 16 is sent to the current controller and the PWM inverter unit 19.

Current controller and PWM inverter section 19
In the above, the magnitude I1 of the primary current of the traveling motor is vector-combined by the torque component current It and the magnetic flux component current Im, and the primary current frequency of the motor is determined by the output angular frequency ω1 of the traveling motor. Further, the speed of the traveling motor 1 is controlled by the current controller and the PWM inverter unit 19 by pulse width modulation (PWM) control.

Next, the operation of the present invention will be described with reference to FIG. FIG. 2 omits the operation during acceleration of the traveling motor. The speed setting units 3-1, 3-2, and 3-3 correspond to SF0, SF1, and SF2, respectively, the speed corresponding to SF0 is N1, the speed corresponding to SF1 is zero speed, and S
The speed corresponding to F2 is set to N2. The switch input is not described in FIG.
There is an EV input, and FIG. 2 shows a case of a forward rotation input FW. In addition, the torque limit TL is turned on when the torque limit enable switch 14 (“torque limit TL” signal in FIG. 2) is turned on, and the torque limit changeover switch CH2 (“torque limit changeover CH2” signal in FIG. 2) is turned off. To select the first torque limit, and to select the second torque limit. When the torque limit effective switch 14 (“torque limit TL” signal in FIG. 2) is turned off, it is possible to output up to the maximum torque.

The acceleration time switching CH1 switches the acceleration and the deceleration time between first and second. When CH1 (the "acceleration / deceleration time switching CH1" signal in FIG. 2) is off, the load swing is minimized for crane traveling. Optimum first acceleration / deceleration time is selected. CH1 (the "acceleration / deceleration time switching CH1" signal in FIG. 2) is on, the second acceleration / deceleration time is selected, and the minimum acceleration / deceleration time is input. That is, the acceleration / deceleration function is canceled when CH1 is turned on. The speed setting corresponds to the switch, and the multi-speed (zero speed) SF1 and the multi-speed (N
1) SF0, multi-stage speed (N2) SF2. In the time chart, the solid line indicates the actual speed of the crane traveling motor, and the two-dot chain line indicates the speed command of the output of the acceleration / deceleration calculator 5. First, SF0 (switch 4-1) is on, and the crane traveling speed is operating at N1. Next, at time t1 when the coasting operation is started, the torque limit TL is turned on, and at time t2, the acceleration / deceleration time switching CH1 is turned on.
In step 3, SF1 is turned on. In FIG. 2, “multi-stage speed (zero speed) SF
When the "1" signal is on, the speed set by the speed setting unit 3-2 is valid, and when the "multi-stage speed (N1) SF0" signal is on, the speed set by the speed setting unit 3-1 is valid.
Speed setting device 3 when "Multi-stage speed (N2) SF2" signal is on
The speed set in -3 is effective. Note that SF0, S
F1 and SF2 are logically prioritized so as not to be valid at the same time.
1, SF0 and SF2 are given priority in this order. For this reason,
When SF1 is input, the speed is torque-limited, but goes to zero speed. Next, at time t4, SF0 turns off. In the section indicated by A where the foot brake is turned on, the running motor has a steep slope of deceleration, and in the section B where the foot brake is turned off, the slope of deceleration becomes gentle.

At time t3, the speed command indicated by the two-dot chain line is instantaneously set to zero because the acceleration time switching CH1 is ON and the zero speed of SF1 is selected. The coasting operation is from t3 to t6, and SF1 is turned off at time t6.
At time t5, the multi-stage speed SF2 is turned on for the next preparation.

At time t6, the zero speed command of the multi-stage speed SF1 is released, so that the speed command is given by the multi-stage speed SF2, and the speed N2 is set. At the same time, torque limit switching CH2
Is turned on, and the first torque limit value is changed to the second torque limit value. The setting of the second torque limit value is set to a torque limit value at which the crane traveling speed is moderately accelerated, and is set to a value larger than the first limit value. For this reason, the crane traveling motor operates at the speed N at the second torque limit value.
Accelerate to 2.

At time t7 when the speed reaches N2, the torque limit TL is turned off and the torque limit is released, so that the torque of the traveling motor can be output up to the maximum torque. After releasing the torque limit or simultaneously with the torque limit switch C
H2, after the acceleration / deceleration time switching CH1 is turned off, time t8
To select the zero speed of the multi-stage speed SF1, decelerate and stop according to the deceleration time set in the first acceleration time. In FIG. 2, since the traveling crane is too short of the stop position, it is not necessary to wait until it stops before re-acceleration in the case of re-acceleration. The coasting operation is from time t3 to t6. In this section, since the speed command is zero and the actual speed is high, even when the torque is limited, the motor performs regenerative braking and assists the foot brake.

In FIG. 2, the operations at t2 and t3 are reversed. At t2, the zero speed SF1 is switched from off to on. At t3, the acceleration time switchover CH1 is switched from off to on. Therefore, the order is not particularly defined.

The same applies to FIGS. 3 to 6 described below.

FIG. 3 shows the reverse rotation operation when the stop position is about to exceed the predetermined position.
From time t6 to time t6 (at time t6 in FIG. 2).
Then, the "forward FW" signal is turned on, and the "forward FW" signal is switched off from the "forward rev" signal off state. Other operations are the same as those in FIG.

FIG. 4 is different from FIG. 2 in that, during coasting, the speed setting is not switched to the zero speed of SF1 and the N1 of SF0 is not changed.
Leave. For this reason, since the speed setting is higher than the actual speed, the motor performs a power running operation although the torque is limited. When the torque limit value is adjusted to the load torque, the torque generated by the motor becomes substantially equal to the load torque. Therefore, when the foot brake is off, the speed is substantially horizontal, and the vehicle is driven in the power-on state.

FIG. 5 shows the state of FIG.
In the same manner as described above, the power running operation is switched from the forward rotation FW to the reverse rotation REV.

FIG. 6 is a combination of FIG. 3 and FIG.
When the foot brake is on, the motor sets a speed command to zero speed so as to perform regenerative operation, and works to assist the foot brake. When the foot brake is off, the speed setting is N1 of SF1
The motor is switched to power running operation. By adjusting the torque limit value, it is possible to set a slight acceleration when the foot brake is off so that the operator can easily adjust the target position.

Next, FIG. 7 shows the configuration of a specific embodiment using a speed sensorless vector control without using a speed sensor. The difference from FIG. 1 is that there is no pulse generator 2 which is a speed sensor for detecting the speed of the traveling motor. or,
In FIG. 1, the current controller and the PWM inverter 19
In addition, the primary angular frequency ω1 is given by obtaining the slip angular frequency ωs from the torque component current It and further adding this ωs to the speed signal ωr, but in FIG. 7, the current controller and the PWM inverter 19 , The slip frequency ωs is determined by the slip angular frequency calculation 15 from the torque component current Itf, and ω1−ωs is calculated by the subtractor 8a to determine the speed signal ωr. In FIG. 7, the magnetic flux component current Im is controlled by a speed signal ωr at a certain speed or less, and when the speed exceeds the certain speed, the flux is weakened. However, in FIG. 7, a speed sensor (pulse generator 2) is used. ), There is no output angle frequency ω1. In this case, the speed detecting means calculates the slip angular frequency calculation 15, the current controller and P
It is composed of the WM inverter unit 19.

The foot brake operation during deceleration, the torque limit TL, the torque limit switching CH2 of the first torque limit value and the second torque limit value, the acceleration / deceleration time switching CH1, the multi-speed (N
1) SF0, multi-speed (zero speed) SF1, multi-speed (N2) S
The operation at the timing of F2 is exactly the same as that in FIGS.

According to the above embodiment, at the time of deceleration during coasting, when the traveling crane is likely to stop in front of the target position while the foot brake is operated or the foot brake is released by the operator, the speed at which the vehicle is currently operating is reduced. There is an effect that the vehicle can be re-accelerated or reversed, and the corresponding operation can be quickly performed, and the vehicle can be easily stopped at the target position as the operator intends. In addition, the acceleration / deceleration torque of the inverter can be adjusted during the running motor operation, acceleration, deceleration, and reverse rotation, so that there is an effect that the acceleration or deceleration can be smoothly performed without greatly increasing the load swing. Furthermore, using a vector control inverter with a sensor,
Since this can be realized by adjusting the torque command It, the response can be improved to ten times or more of the conventional V / F inverter, and there is an effect that the load can be absorbed by the acceleration / deceleration operation by the operator.

FIGS. 8 and 9 show a torque limit input TL, a torque limit value switch CH2 for switching between the first torque limit value and the second torque limit value, an acceleration / deceleration time switch CH1, and a multi-speed (N1) S.
The timing operation of F0, multi-speed (zero speed) SF1, and multi-speed (N2) SF2 is automatically generated inside the inverter. In the figure, 20 is a deceleration input switch, 21a and 21b are resistors, 22 is a photocoupler, 23
Is a timing generation circuit, and PV and Vcc are control power supplies insulated from each other. The photocoupler 22 is a deceleration input switch 20
Used to electrically insulate the logic side of the inverter from the logic side of the inverter. When the deceleration input switch 20 is turned on, the photocoupler 22 is turned on, and the timing generation circuit 2
3 and the times t1 to t4 shown in FIGS. When the deceleration input switch 20 is turned off, the times t5 to t9 shown in FIGS. 2 to 6 occur, and the crane traveling inverter in which the deceleration timing is automatically performed by the traveling inverter by the traveling inverter. is there.

According to the embodiments shown in FIGS. 8 and 9, the timing generation circuit can be integrated in the inverter unit, and the inverter device can be integrated in a compact manner as a crane control.

FIG. 10 shows another embodiment of the present invention, in which the portion of the second torque limit value 12-2 in FIGS. 1, 7, 8, and 9 is implemented by another method. In FIGS. 1, 7, 8, and 9, the second torque limit value is a fixed value set by a nonvolatile memory or a volatile memory, a variable resistor, a digital switch, or the like. Using a potentiometer 12-4, a DC power supply 12-3 is connected to both ends of the potentiometer to supply a constant voltage.
FIG. 10 is similar to the embodiment shown in FIGS. 1, 7, 8, and 9 except that the second torque limit value 12-2 is replaced by a potentiometer 12-4.

As the second torque limit value, the negative voltage of the sliding part of the potentiometer and the DC power supply 12-3 is taken out as an output, and is obtained as the terminal voltage Vo. The potentiometer 12-4 can be directly operated by the operator. If the vehicle is likely to stop shortly after the coasting operation, the potentiometer 12-4 re-accelerates, and if it goes too far, it reverses. However, the operator adjusts the second torque limit value. It is made possible.

FIG. 11 is a diagram showing a mechanism in which the potentiometer 12-4 is linked with a stepping accelerator switch. Reference numeral 31 denotes a base of the accelerator switch for stepping, 32 denotes a step platform, and a spring 33 is attached between the base 31 and the step platform 32. When the stepped foot is released, the spring returns to its original state. Reference numeral 38 denotes a support fitting for fixing the base 31 and the step 32. Numeral 34 denotes a slide bar for transmitting the stepping angle θ of the step 32 to the potentiometer 12-4, and converts the rotary motion into a reciprocating motion. A fixing screw 36 fixes the step 32 and the slide bar 34. The slide bar 34 is pressed by a slide bar holder 37. On the other hand, a connecting plate 35 is attached to the potentiometer 12-4, and is attached to the slide bar 34 with a universal stopper 39.

When the operator steps on the tread plate 32 by θ, the slide bar 34 is lowered and the potentiometer 12
−4 rotates θp. FIG. 12 shows the relationship between these operations.
Stepping angle θo on the horizontal axis Potentiometer 12-4 on the vertical axis
Output voltage Vo. When not stepping on, the output is V01 at the initial angle θo, and VO2 is output at the maximum stepping angle θmax. Depending on the degree to which the operator steps, the acceleration torque,
Alternatively, the torque for reverse rotation can be adjusted, and the more the step is depressed, the larger the torque is, so that the acceleration can be adjusted as if the driver were stepping on the accelerator of the vehicle.
Although the accelerator is used in FIG. 11, the operation is not limited to the operation with the foot but may be performed with the hand, as long as the operator can easily change the set value. The mechanism in FIG. 11 shows an example in which the stepping amount is converted into an angle, but the mechanism is not limited to this. According to the configuration of the embodiment shown in FIGS. 10 to 12 in this manner, the deceleration is performed by the foot brake, and the acceleration is performed by the second limit torque adjustment.
This has the effect of enabling easy-to-use crane running operation that can adjust the acceleration as if pressing the brake and accelerator of the car.

The embodiments of the present invention have been described above. According to these embodiments, the following effects can be obtained.

1) During coasting, the running motor can be re-accelerated and reversed quickly without stopping, so that the motor can be easily stopped at the target position according to the operator's intention.

2) After coasting, the acceleration time of the inverter can be changed by the second torque limit value, so that it can be set according to the preference of the operator.
Since the operator can freely switch to the torque limitation, the degree of load swing prevention can be adjusted.

3) Since the operator can respond at high speed, the operator can turn on / off the foot brake during driving in order to suppress the deflection of the load, thereby improving usability.

[0052]

1) When the crane is stopped at the target position, even if the crane does not reach the target position or goes too far, the traveling motor can be quickly re-accelerated and reversed without temporarily stopping. Can be easily stopped at the target position as will be described.

2) When the crane is stopped at the target position, the maximum torque value, the first torque limit value, and the second torque limit value are switched, and the torque can be adjusted, so that the load swing does not greatly increase. Acceleration or deceleration can be performed smoothly, improving usability.

3) By using the vector control inverter having the speed detecting means, a high-speed response can be made, so that the operator can turn on and off the foot brake during driving in order to suppress the load swing, thereby improving the usability. .

[Brief description of the drawings]

FIG. 1 is an embodiment of a control configuration diagram according to the present invention.

FIG. 2 is a time chart at the time of re-acceleration of one embodiment according to the present invention.

FIG. 3 is a time chart at the time of reverse rotation of one embodiment according to the present invention.

FIG. 4 is a time chart at the time of re-acceleration of another embodiment according to the present invention.

FIG. 5 is a time chart at the time of reverse rotation of another embodiment according to the present invention.

FIG. 6 is a time chart at the time of reverse rotation of still another embodiment according to the present invention.

FIG. 7 is another embodiment of a control configuration diagram according to the present invention.

FIG. 8 shows an embodiment in which a timing circuit is provided in the inverter unit of the present invention.

FIG. 9 shows another embodiment in which a timing circuit is provided in the inverter unit of the present invention.

FIG. 10 shows an embodiment in which the second torque limit value is variable according to the present invention.

FIG. 11 is a machine configuration diagram for generating a second torque limit value according to the present invention.

FIG. 12 is a characteristic diagram for explaining the present invention.

FIG. 13 is a time chart for explaining the operation of the conventional technique.

[Explanation of symbols]

1 ... induction motor (motor) 2 ... pulse generator
3-1, 3-2, 3-3: speed setting device or speed data, 4-1, 4-2, 4-3: switch, 5: acceleration / deceleration calculator, 6-1, 6-2: acceleration / deceleration Time data, 7 ...
Acceleration / deceleration time changeover switch, 8: subtractor, 9: error adjuster, 10: torque limiter, 11: minimum value circuit,
12-1: First torque limit value, 12-2: Second torque limit value, 12-3: DC power supply, 12-4: Potentiometer, 13: Maximum torque value, 14: Torque limit effective switch, 15: Slip frequency Arithmetic unit, 16: adder, 17: speed calculation unit, 18: magnetic flux controller, 19
... Current controller and PWM inverter section 8a Subtractor 17a Speed calculation section 20 Deceleration input switch 21a 21b Fixed resistance 22 Photocoupler 23 Timing generation circuit 24a 24b
Inverter unit, 25: Torque limit switch, 30: Brake, 31: Base, 32: Step platform,
33 ... spring, 34 ... slide bar, 35 ... connecting plate, 36
... fixing screws, 37 ... slide bar holder, 38 ... support brackets, 39 ... universal stoppers.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kei Tomojiri 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd.

Claims (10)

[Claims] 1. A crane traveling motor, a speed detecting means for detecting a speed of the crane traveling motor, a speed calculating unit inputted from an output signal of the speed detecting means, a multi-stage speed setting device for crane traveling, a multi-stage A switch for selecting a speed setting device, an acceleration / deceleration calculator, a switch for switching the first or second acceleration / deceleration time, a vector inverter having a torque limit input switch, and a machine mounted on the output shaft of the crane traveling motor. A brake that applies a specific braking force is provided, and during the coasting operation of the crane, the torque is limited by the first torque limit value while the inverter and the motor are electrically connected, and the deceleration time is minimized. By switching and setting the zero speed command, the brake is operated and decelerated while the inverter is in the power-on state. Crane traveling device to drive switch to limit. 2. The method according to claim 1, wherein the inverter is operated in a power running state.
The crane traveling device as described. 3. An inverter is switched between a regenerative state and a powering state.
The crane traveling device according to claim 1, wherein the crane traveling device is operated in a regenerative state when the brake is on and a power running state when the brake is off. 4. A crane traveling motor, a crane traveling multi-stage speed setting device, a switch for selecting the multi-stage speed setting device, an acceleration / deceleration calculator, and a switch for switching between a first and a second acceleration / deceleration time. A vector inverter having a torque limiting input switch, a speed calculator for calculating the speed of the crane traveling motor based on the output frequency of the inverter, and applying a mechanical braking force to the output shaft of the crane traveling motor. Equipped with a brake, and during the coasting operation of the crane, in a state where the inverter and the motor are electrically connected, a torque limit is applied by the first torque limit value,
A crane that switches the deceleration time to the shortest time, sets a zero speed command, activates the brake while the inverter is in the power-on state, decelerates, and switches to the second torque limit value during re-acceleration or reverse operation. Traveling device. 5. The crane traveling apparatus according to claim 4, wherein the inverter is operated in a power running state during the coasting operation of the crane. 6. The crane traveling apparatus according to claim 4, wherein the inverter is switched between a regenerative state and a powering state during coasting operation of the crane, and is operated in a regenerative state when the brake is on and a powering state when the brake is off. 7. A crane traveling motor, speed detecting means for detecting a speed of the crane traveling motor, a notch controller for selecting a multi-stage speed for the crane traveling, and a mechanically connected output shaft of the crane traveling motor. A crane traveling device comprising: a brake for applying an appropriate braking force; and an inverter for driving the crane traveling motor to a speed selected by the notch controller when the notch controller is switched. An acceleration / deceleration time changeover switch for switching a change time of a speed command signal, the inverter configured as a vector inverter having a torque limiting function, and the notch controller for setting the speed command to zero speed and operating the brake to decelerate the speed command. First torque of torque limiting function Multiplied by the torque limited by the limit value,
During the deceleration, the notch controller issues a speed command to the second
A crane traveling device, comprising: a control unit that switches to apply a torque limit based on a second torque limit value of the torque limiting function during a re-acceleration or reverse rotation operation at a high speed. 8. The crane traveling apparatus according to claim 7, further comprising means for changing the second torque limit value by stepping or manually. 9. A switch for selecting a multi-stage speed setting device for controlling the speed of the crane traveling motor, a first and a second acceleration / deceleration time switch for switching the time of an acceleration / deceleration calculator, and a first and a second switch. 2) An input switch for inputting the torque limit input switch during the coasting operation of the crane and during the re-acceleration or reverse operation, and the on / off operation of the input switch automatically controls the on / off timing inside the vector inverter. Inverter device. 10. A means for selecting a multi-stage speed setting device for controlling the speed of a crane traveling motor, an acceleration / deceleration time switching means for switching the time of an acceleration / deceleration calculator, a terminal for inputting a deceleration command, An inverter device for traveling a crane, comprising timing generation means for generating a timing signal for deceleration, re-acceleration, and reverse rotation operation inside a vector inverter when a deceleration command from a command input terminal is turned on and off.