KR200230363Y1 - Load and current detector for crane and truck - Google Patents

Abstract

The present invention detects the weight and the amount of current at the time of load detection, thereby reducing the probability of accidents caused by equipment failure due to overweight or overcurrent, and improving the productivity by improving the equipment operation rate. The present invention relates to an applied load and current detection device, which includes a weight detection device and an overload safety device in one system, and solves problems such as reliability deterioration and structural defects of the load cell due to the weight deviation occurring during field use. As well as improving the weight detection function and safety function against overload, it is possible to improve the reliability and the operation rate by improving the economic efficiency and convenience of management by eliminating redundant facilities.

Description

Load and current detector for crane and trucks {Load and current detector for crane and truck}

The present invention relates to a load and current detection device that is applied to cranes and bogies, and more particularly, the probability that an accident may occur due to an overload or an equipment failure due to the detection of the current and the amount of current at the same time. The present invention relates to a load and current detection device applied to cranes and bogies that can lower the cost, improve facility utilization, and improve productivity.

1 is a view showing the configuration of a load detection device of a conventional overhead traveling crane.

As shown in the figure, a conventional overhead crane includes a motor 1, a wire drum 2, a wire rope 3, a summing box 4, and a load cell controller ( load cell controller (5), control room (6), equalizer sheave (7), load cell (8), load cell cable (9), etc. It is organically connected and is comprised so that the article 11 may be wound up or moved.

In the construction of the overhead crane, the load cell 8 is provided with a strain gauge directly responsible for the detection of the weight, which is a sensor for detecting mechanical minute changes as an electrical signal. The strain gauge includes an electrical resistance wire made of metal such as Constantan, Nichrome, and the like, and uses the Wheatstone bridge circuit to take out a resistance change as a voltage change.

The load cell 8 is mounted to an equalizer sheave 7, which is connected to a wire rope 3. Therefore, the change in the weight generated by the load 16 and the load of the wire rope 3 is sensed by the strain gauge of the load cell 8, and the resistance value detected by the strain gauge and converted into an electrical signal is measured by the load cell cable 9. It is transmitted by, and the load cell controller 5 is controlled by the resistance value as a data.

According to the conventional weight detection method as described above, since the load cell 8 mounted on the equalizer sheave 7 is sensitive to the change of the load, there are many errors in the change of the resistance value, thereby causing the inaccuracy of the weight detection. In addition, the resistance of the strain gauge is detected only by the change of the load, and the change of the current which may occur when the motor 1 is driven is not sensed. There was a problem of deterioration.

In addition, since the metal resistance element constituting the strain gauge has a function of stretching and contracting depending on the material, cracks and breakage of the notch part due to the mechanical and physical change of the metal resistance element and the change of the added load are prevented. There is a problem that causes frequent failure of the equipment, resulting in a decrease in the utilization rate of the equipment.

In addition, in the conventional cranes and trolleys, a load cell 8, which is a weight detection device that has to be weighed at the time of shipment of a product, and a load limiter, which is an electrical device that operates when an additional load exceeds a standard, Since the structure is installed in a double, the weight deviation according to the installation location is large, the operation reliability is lowered and the maintenance and repair of the maintenance worker is inconvenient.

The present invention has been devised to solve the problems as described above, when working with cranes and trolleys, equipped with a weight detection device and an overload safety device in one system to reduce the reliability caused by the weight deviation occurred during on-site use It solves the problems of structural defects of load cell, improves maintenance, and meets weight detection function and safety function against overload, thereby ensuring economic efficiency and convenient management by eliminating redundant facilities. It is an object of the present invention to provide a load and current detection device applied to cranes and bogies that can increase the reliability of equipment and increase the operation rate.

1 is a configuration diagram of a load detection device of a conventional overhead crane;

2 is a configuration of the overhead crane with a load and current detection device according to the present invention,

3 is a schematic configuration diagram of a load detection system according to the present invention;

4 is a schematic configuration diagram of a display device of a load detection system according to the present invention;

5 is a flowchart illustrating an operation of detecting a load by the present invention;

6 is a flowchart illustrating an operation of detecting a current amount according to the present invention.

<Brief description of the symbols of the main parts of the drawings>

1 motor, 2 wire drum,

3 ... wire rope, 4 ... summing box,

5 ... load cell controller, 6 ... control room,

7 ... equalizer sheave, 8 ... load cell,

9 ... load cell cable, 10 ... hook,

11 ... load, 12 ... load detection system,

12-1 ... power supply, 12-2 ... DC amplification circuit,

12-3 ... filter, 12-4 ... A / D converter,

12-5 ... alarm generating device, 12-6 ...

12-6-1 ... Power supply indicator, 12-6-2 ...

12-6-3 ... weight display, 12-6-4 ... current display,

12-6-5 ... Overweight and overcurrent indicator, 12-6-6 ... Alarm generation indicator,

13 ... motor cable, 14 ... current transformer.

In order to achieve the above object, the present invention provides a load and current detection device applied to a crane and a truck equipped with a load cell having a strain gauge, wherein the load and current detection device includes a load detection system and a current transformer, The load detection system includes a power supply for supplying power for operation, a DC amplification circuit for amplifying an analog signal detected and output from the load cell, a filter for canceling noise generated from the DC amplification circuit, and An A / D converter that converts the analog signal passed through the filter into a digital signal, an alarm generator that sounds an alarm when overweight or overcurrent, and a display device that displays the digital signal passing through the A / D converter and various situations Through the load cell cable to the summing box, which is a strain gauge control box. To be connected to the load cell, said current transformer is connected to one end and that the load-detecting system, the other end is characterized in that connected to the motor via a motor cable.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a block diagram showing a crane with a load and current detection device according to the present invention, the difference from the conventional configuration shown in Figure 1 is the current transformer 14 and the motor cable 13 is further The load cell controller 5 has been replaced by the load detection system 12. That is, the load detection system 12 according to the present invention is located in the control room 6, one end of which is connected to the summing box 4, which is a strain gauge control box, and the other end of which is connected to the current transformer 14. It is.

The current transformer 14 is connected to the motor 1 through the motor cable 13, the current applied from the motor 1 is transmitted to the current transformer 14 through the motor cable 13, the current The transformer 14 converts the current received through the motor cable 13 into a current value and transmits it to the load detection system 12.

The load detection system 12 is configured to control not only the weight which is a physical quantity that can be obtained by the operation of the load cell 8 but also the amount of current which is an electric quantity that can be obtained by the operation of the motor 1. That is, a function of controlling data related to a current that a load limiter, which is a conventional electrical device, is in charge within a system without having a separate system for detecting weight and amount of current, and a mechanical device such as a load cell. It is now possible to express all the functions of controlling the data concerning the weight in charge. This makes it easier to detect two pieces of data: weight and current, so that more accurate monitoring of plant operation can result in lower equipment failure rates and longer plant life.

3 is a schematic configuration diagram of a load detection system 12 according to the present invention.

As shown in the figure, the load detection system 12 according to the present invention includes a power supply device 12-1, a DC amplification circuit 12-2, a filter 12-3, and an A / D converter 12-. 4) an alarm generating device 12-5 and a display device 12-6.

The power supply device 12-1 is a power supply means for driving a facility such as a crane having a load detection system 12. Accordingly, when the power is supplied by the power supply 12-1, the motor 1, the load cell 8, and other components operate sequentially.

When the hook 10 installed on the crane hoists the load 11, the strain gauge senses the resistance change and the load cell 8 outputs a signal. The DC amplification circuit 12-2 amplifies the output signal. It is a means to.

The filter 12-3 is a means for canceling noise generated when the DC amplifier circuit 12-2 amplifies a signal, and the signal passing through the filter 12-3 is an A / D converter 12-4. Is delivered.

The A / D converter 12-4 is a means for converting an input analog signal into a digital signal, and both the signal output with respect to the weight and the signal output with respect to the current are driven by the A / D converter 12-4. It is converted into a digital signal and displayed on the display device 12-6.

The alarm generating device 12-5 alerts the driver when the weight and current amount detected by the load cell 8 and the current transformer 14 exceed the preset reference value and detect an overweight and overcurrent. As a means, an alarm is automatically generated not only when a request is made through the alarm generation instruction unit 12-6-6 described later but also when it is determined that the overload and overcurrent are determined by the load detection system 12.

FIG. 4 is a schematic configuration diagram of the display device 12-6 of the load detection system 12 according to the present invention. Referring to FIG. 4, each configuration of the display device 12-6 will be described in detail.

The display device 12-6 is an interface between the driver and the facility for displaying various information so that the driver can operate the crane and the truck efficiently and easily. The display device 12-6 includes a power supply indicating unit 12-6-1 and an adjusting unit. 12-6-2, weight display unit 12-6-3, current display unit 12-6-4, overweight and overcurrent display unit 12-6-5, and alarm occurrence instructing unit 12 -6-6) to display digital signals and various situations.

The power supply instructing unit 12-6-1 is connected to the power supply unit 12-1 and is means for instructing to supply power or to stop the power supply.

The adjusting part 12-6-2 is a means for instructing the hook 10 to raise or lower the article 11, and when the overweight and overcurrent are not reached, when the overweight or overcurrent is reached, It can be used in the form of an instruction.

The weight display unit 12-6-3 is a means for displaying the weight according to the change in resistance value detected by the strain gauge in the load cell 8 as a digital signal, and the driver displays the overweight and overcurrent display unit 12-6-5. Even if there is no change, the lifting or lowering of the article 11 may be determined by empirical rule with reference to the value displayed on the weight display unit 12-6-3.

The current display unit 12-6-4 is a means for displaying the output current of the motor 1 as a digital signal, and the driver may change the weight display unit even if there is no change in the overweight and overcurrent display unit 12-6-5. 12-6-3, the empirical rule may be used to determine the lifting or lowering of the load (11).

The overweight and overcurrent display unit 12-6-5 has a weight corresponding to a change in resistance value detected by the strain gauge in the load cell 8 exceeding a limit weight and detected as an overweight or a current value through the motor 1 is increased. It is a means for displaying information about the overcurrent when the limit current is detected. The limit weight may be a rated load, which is a value obtained by subtracting the weight of the hook 10 and other attaching devices from the lifting load.

The alarm generation instruction unit 12-6-6 is a means for requesting the alarm generation device 12-5 shown in FIG. 3 to generate an alarm, and may be used to notify the outside in case of overweight and overcurrent.

FIG. 5 is a flowchart illustrating an operation of detecting a weight by a load detection system 12 according to the present invention having the configuration as described above, and referring to FIGS. 2 to 5 of the load detection system 12 according to the present invention. The weight detection operation will be described in detail.

First, the driver instructs the power supply 12-1 to supply power. At this time, the input power applies a voltage to the motor 1 through a transformer and a relay contact, and the applied voltage can be controlled by a sequence contact, so when the driving of the motor 1 ends, the applied voltage is cut off. The operation of the electrical and mechanical devices is configured to be stopped.

The motor 1 is driven by the application of the power, and the wire drum 2 and the equalizer sheave 7 which are mechanical devices are operated by the driving of the motor 1.

Next, the load cell 8 mounted on the equalizer sheave 7 operates, and the strain gauge of the load cell 8 operates to sense the resistance value.

The signal which is the resistance value of the strain gauge output from the load cell 8 is amplified by the DC amplification circuit 12-2, and the filter 12-3 is in the process of amplifying the signal in the DC amplification circuit 12-2. Remove the noise generated.

The analog signal, which has been amplified and filtered through the DC amplifier 12-2 and the filter 12-3, is converted into a digital signal by a double integration method through the A / D converter 12-4.

Finally, the weight display unit 12-6-3 outputs the weight converted into the digital signal. If overweight occurs in this process, the overweight and overcurrent indicators 12-6-5 are lit, and the alarm generating device 12-5 generates an alarm. It shuts off and the drive of the motor 1 is stopped. Therefore, in the state in which the driving of the equipment is stopped, the mechanic and the driver can prevent the occurrence of equipment failure and accident in advance by lowering the lifting load 11.

FIG. 6 is a flowchart illustrating an operation of detecting an amount of current by the load detection system 12 according to the present invention having the configuration as described above. Referring to FIGS. 2 to 4 and 6, the load detection system according to the present invention ( The current detection operation of 12) will be described in detail.

First, the driver instructs the power supply 12-1 to supply power. At this time, the input power applies a voltage to the motor 1 through a transformer and a relay contact, and the applied voltage can be controlled by a sequence contact, so when the driving of the motor 1 ends, the applied voltage is cut off. The operation of the electrical and mechanical devices is configured to be stopped.

Subsequently, a current is applied to the motor 1 so that the motor 1 is driven. The current is always applied regardless of whether it is a load hoist or a no load hoist.

Next, the current transformer 14 converts the applied current into a current value and transfers this value to the A / D converter 12-4. The A / D converter 12-4 converts the received analog signal into a digital signal.

Finally, the current display unit 12-6-4 outputs the amount of current received as a digital signal. When overcurrent occurs in this process, the overweight and overcurrent display unit 12-6-5 lights up, and the alarm generating device 12-5 generates an alarm, and the applied voltage is cut off to The drive is stopped. Therefore, in the state in which the operation of the equipment is stopped, the mechanic and the driver check the burnout state of the motor 1 and check whether it is overweight, and lower the hoisted load 10 at the time of overload, thereby preventing the occurrence of equipment failure and accident. To prevent.

As described above, the load recognition operation and the current amount recognition operation of the load detection system 12 are performed simultaneously, and are configured to perform detection and control of overweight and overcurrent in one system.

According to the present invention, it is equipped with a load detection system capable of detecting the weight and the amount of current in the crane and the bogie at the same time to detect both the overweight and the overcurrent in one system, so that the operation is simple and the operation status of the equipment This enables more accurate detection of equipment, which can lower the rate of equipment failure and further increase the capacity of the equipment and prevent accidents.

Claims (2)

In the load and current detection device applied to a crane and a load cell equipped with a load cell having a strain gauge, The load and current detection device is composed of a load detection system and a current transformer, The load detection system A power supply for supplying power for operation, A DC amplification circuit for amplifying the analog signal detected and output by the load cell; A filter for canceling noise generated in the DC amplifier circuit; An A / D converter for converting the analog signal passing through the filter into a digital signal; Alarm generation device that alarms the alarm when overweight or overcurrent, It is composed of a display device for displaying the digital signal passed through the A / D converter and various situations, The load cell is connected to the load cell via a summing box which is a strain gauge control box through a load cell cable, The current transformer is a load and current detection device applied to the crane and the balance, characterized in that one end is connected to the load detection system, the other end is connected to the motor through a motor cable. The method of claim 1, The display device A power supply indicator connected to the power supply to instruct power to be turned on or off, A control unit for instructing the movement of the load, A weight display unit displaying a weight according to a change in resistance value detected by the strain gauge of the load cell as a digital signal; A current display unit for displaying the output current of the motor as a digital signal, Overweight that displays information when the weight according to the resistance change detected by the strain gauge of the load cell exceeds the limit weight and is detected as an overweight or the current value through the motor exceeds the limit current and is detected as an overcurrent and An overcurrent display, A load and current detection device applied to a crane and a truck, characterized by comprising an alarm generation indicator for requesting the alarm generation device to generate an alarm when an overweight or an overcurrent occurs.