JPH05322703A - Device for detecting control failure in lowering in cargo handling equipment - Google Patents

Abstract

PURPOSE:To provide a device for detecting control failure in lowering in cargo handling equipment for detecting presence of control failure in lowering in a low speed range where load is not applied to a brake. CONSTITUTION:A device comprises a designates speed power generator 3 connected to a motor to drive a cargo handling machine to lift/lower a cargo, and a timer to hold operation in a low speed operation range for a specified time even when it receives a high speed lowering command, in lowering the cargo. It also comprises a control failure detection relay 16 to compare a cargo lowering speed detected by the designated speed power generator 3 with the upper limit speed for low speed operation in operation in the low speed operation range which is preliminarily set, and output an abnormality detection signal to actuate a brake so as to stop lowering the cargo.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unwinding control failure detecting device for detecting control failure during unwinding of cargo handling equipment for hoisting and lowering cargo handling.

[0002]

2. Description of the Related Art FIGS. 5 and 6 are views showing the configuration of a conventional mechanical and electric unwinding control failure detecting apparatus for cargo handling equipment. In the figure, 1 is a motor, 2 is a brake, 3 is a DC finger speed generator, 4 is a centrifugal force speed switch set at 130% speed, 5 is a coupling, 6 is a controller, 7 is a printed circuit board, 8 Is a resistor for speed feedback adjustment, and 9 is a voltage relay set to a value 1.3 times the full speed value.

FIG. 7 is a diagram showing a speed transition at the start of conventional winding control, in which the vertical axis represents speed and the horizontal axis represents time.

In the case of the mechanical type shown in FIG. 5, the motor 1
The rotation speed is detected by the centrifugal force speed switch (governor switch) 4 connected to the shaft of
It was operating at 0% overspeed, turning off the power and tightening brake 2. On the other hand, in the case of the electric type shown in FIG. 6, the DC finger speed generator 3 is used to detect the voltage, the speed feedback adjusting resistor 8 is set, and the voltage relay 9 is used.
At that time, it was operated at an overspeed of 130% of the full speed value, the power was turned off, and the brake 2 was tightened.

[0005]

The conventional unwinding control failure detecting device for cargo handling equipment is constructed as described above, and the safety device against overspeed detects about 130% overspeed. During the unwinding operation at the rated load of a crane, etc., depending on various conditions, it may not be stopped by the brake and the suspended load may slide down. The braking energy required by the brake is proportional to the square of the rotation speed. Therefore, there is a problem that the braking performance of the brake is deteriorated due to lack of braking energy.

The present invention has been made in order to solve the above-mentioned problems, and the unwinding control of the cargo handling equipment for detecting the presence or absence of the unwinding control failure in the low speed region where the brake is not burdened. The purpose is to obtain a defect detection device.

[0007]

The unwinding control failure detecting device for cargo handling equipment according to the present invention is connected to an electric motor for driving the cargo handling machine to hoist and lower the cargo handling machine, and the winding operation of the cargo handling machine is performed through the electric motor. A finger speed generator that detects the hoisting and lowering speed, a low-speed operation area holding unit that holds the operation in the low-speed operation area for a predetermined time even when receiving a high-speed unwinding command during cargo unloading, and in the low-speed operation area for the predetermined time. During operation, the lowering speed of the cargo handling detected by the finger speed generator is compared with the upper limit speed during low speed operation in the preset low speed operation region, and the lowering speed of the cargo handling is low speed operation. If the time upper limit speed is exceeded, it is determined that the control is defective during unwinding, and control failure detection means that outputs an abnormality detection signal to operate the brake that stops the lowering of the cargo handling is provided.

[0008]

According to the present invention, the low speed operation area holding means holds the operation in the low speed operation area for a predetermined time even when a high speed unwinding command is received during the cargo unloading operation, and the control failure detection means operates the low speed operation for the predetermined time. During operation in the operation area, the lowering speed of the cargo handling detected by the finger speed generator is compared with the upper limit speed during low speed operation in the preset low speed operation area, and the lowering speed of the cargo handling is If it exceeds the upper limit speed during low speed operation, it is determined that the control is unsuccessful during unwinding, an abnormality detection signal is output, and the brake that stops the lowering of the cargo handling is operated.

[0009]

【Example】

Example 1. An embodiment of the first invention will be described with reference to FIGS. In the figure, the same reference numerals as those of the conventional example indicate the same or equivalent elements as those of the conventional example.

FIG. 1 is a schematic diagram showing the construction of an unwinding control failure detection device for cargo handling equipment, and FIGS. 2 and 3 are low-speed region holding circuits for the unwinding control failure detection device for cargo handling equipment shown in FIG. 1, respectively. 6A and 6B are a low speed region control failure detection circuit diagram. 1 to 3
In Fig. 1, 8 is a resistance for speed feedback adjustment,
In FIG. 3, 10 is a voltage relay set to a value 1.2 to 1.3 times the low speed value, 11 is a hoisting / lowering low speed notch,
12 is a high speed notch for winding and lowering, 13 is a low speed relay,
Reference numeral 14 is a high-speed operation timer (a low-speed operation timer for a certain time when high-speed acceleration is required), 15 is a high-speed operation relay, 16 is a control failure (abnormality) detection relay, and 17 is an operation prevention timer at the time of notch return.

The device according to the present invention is equipped with a device for automatically performing a low speed operation for a certain period of time even when the unwinding operation is performed at a high speed and performing a speed check in that area to detect a control failure. is there.

In FIG. 1, the DC finger speed generator 3 is used to detect the voltage in the same manner as the conventional one, and the overspeed detection voltage relay 9 is 130% of the full speed value, and the low speed region speed failure (abnormal).
Two-level speed failure (abnormal) in the detection voltage relay 10
Check.

In FIG. 2 and FIG. 3, even if a high speed command is immediately input, the low speed region speed defect (abnormality) detection voltage relay 10 checks the control defect by providing the low speed region for a certain period of time. It has a circuit configuration.

That is, the conventional overspeed detection is performed by setting the full speed value to 130.
%, The control failure state is checked by speed check in the low speed operation area, and when high speed unwinding operation is performed, the automatic operation is performed by the high speed operation timer 14 as the low speed operation area holding means at the start of operation. By holding the low speed state for several seconds, the feedback voltage is read from the DC finger speed generator 3 and compared with the regular feedback voltage as the preset upper limit speed during low speed operation to detect the control failure as the control failure detection means. The relay is checked for control failure, and if an abnormality in the control device is detected, the emergency brake (not shown) is activated.

Next, the operation of the sequence circuit shown in FIGS. 2 and 3 will be described. In FIG. 2, the low-speed operation relay 13 is attracted by the hoisting / lowering low-speed notch 11, the low-speed operation timer 14 holds the low-speed operation for a predetermined time during high-speed acceleration, and then the high-speed operation relay 15 is attracted. It is a circuit configuration.

In FIG. 3, as conditions for attracting the control failure (abnormality) detection relay 16, the contact of the low speed operation relay 13 is turned on in the low speed region, and the contact of the voltage relay 10 is turned on (detection of control failure) at a predetermined speed of the low speed notch or more. , So that the control failure detection relay 16 does not operate when the notch is returned,
The escape prevention timer 17 is provided for a certain period of time.

As shown in FIG. 4, if the vertical axis = speed and the horizontal axis = time, the low speed region is maintained for a certain period of time, a speed check is performed, and when an abnormality occurs, the operation can be stopped with the braking capacity of the brake being small. ..

In the first embodiment, the low speed operation area holding means and the control failure detection means are constituted by hardware such as a timer and a relay. However, software for programming the above operation procedure by using a microcomputer is shown. Similar effects can be obtained with the configuration.

[0019]

As described above, according to the present invention, at the time of cargo unloading, the low speed operation area holding means for maintaining the operation in the low speed operation area for a predetermined time even if a high speed unwinding command is received, and the above-mentioned predetermined operation. Time During operation in the low speed operation area, the lowering speed of the above cargo handling detected by the finger speed generator is compared with the preset lower speed upper limit speed during operation in the low speed operation area. And the control failure detection means for outputting an abnormality detection signal for activating the brake that stops the unwinding of the cargo handling, so that the unwinding control of the cargo handling in the low-speed operation region where the braking capacity of the brake is small. There is an effect that a defect can be detected, and an item with high safety can be obtained that can perform an emergency stop without putting a load on the brake.

[Brief description of drawings]

FIG. 1 is a block diagram of an unwinding control failure detection device for cargo handling equipment according to an embodiment of the present invention.

FIG. 2 is a low-speed area holding circuit diagram of the unwinding control failure detection device shown in FIG.

FIG. 3 is a low speed region control defect detection circuit diagram of the unwinding control defect detection device shown in FIG.

FIG. 4 is a graph showing a relationship between speed and time during a lowering operation of the unwinding control failure detection device shown in FIG. 1.

FIG. 5 is a block diagram of a conventional mechanical unwinding control failure detection device for cargo handling equipment.

FIG. 6 is a block diagram of a conventional unwinding control failure detection device for a cargo handling facility.

FIG. 7 is a graph showing the relationship between speed and time during the unwinding operation of the unwinding control failure detection device for the conventional cargo handling equipment shown in FIGS. 5 and 6.

[Explanation of symbols]

1 Motor 2 Brake 3 DC finger speed generator 4 Centrifugal force speed switch set to 130% speed 5 Coupling 6 Control failure detector 7 Printed circuit board 8 Speed feedback adjustment resistor 9 1.3 times the full speed value Voltage relay 10 set to 1.2 to 1.3 times the low speed value voltage relay 11 hoisting / lowering low speed notch 12 hoisting / lowering high speed notch 13 low speed operation relay 14 high speed operation timer (Low-speed operation timer for a certain period of time during high-speed acceleration) 15 High-speed operation relay 16 Control failure (abnormality) detection relay 17 Notch return operation prevention timer

Claims (1)

[Claims] 1. A finger speed generator connected to an electric motor for driving a cargo handling machine to hoist and lower the cargo handling, and detecting a hoisting and lowering speed of the cargo handling via the electric motor;
A low speed operation area holding means for holding the operation in the low speed operation area for a predetermined time even after receiving the high speed unwinding command, and the cargo handling detected by the finger speed generator during the operation in the low speed operation area for the predetermined time. The lowering speed is compared with the lower speed upper limit speed in the operation in the preset low speed operation region, and if the lowering speed of the above cargo handling exceeds the lower speed upper limit speed, it is determined that the unwinding control is poor, An unwinding control failure detection device for cargo handling equipment, comprising: a control failure detection means for outputting an abnormality detection signal to operate a brake for stopping the unwinding of the cargo operation.