In some steel metallurgical plants, sometimes the electronic scale cannot be used because the too high temperature or the lifting height of the crane is not enough, especially when the lifting tonnage is particularly large, the cost of the large tonnage of the electronic overhear crane scale is increased more, the lifting height and The use of the hook scale is limited by the high temperature limit, but there is a need to measure the weights that are lifted during the work. In this case, VOZ and the crane factory jointly developed the overhear crane scale.
big screen
Orbital overhear crane scale installation diagram
Weighing control instrument
Antenna transmitting A/D box
Schematic diagram of the pulley type overhear crane scale
Crane cart
Due to many restrictions on the crane, such as space, installation difficulty and other factors, depending on the scene, the overhear crane scale installation methods are also diverse, such as fixed pulley type, small car model, track type.
Electronic overhead crane scale naming rules
Instrument model
Accessory configuration
TC-bearing type
TP-bypass
TP-pressure type
TL-pull
TG-track type
TD-double car type
TP- fixed pulley
TX-axis pin type
Form code: CY-overhead crane electronic weighing equipment wired transmission
          CS-overhead crane electronic weighing equipment wireless transmission
Expressed in units: tons, kilograms
Rated capacity: expressed in 1 or more digits
Structure model: TC, TY, TP, TL, etc.
Usually, there are five ways to install
1. Fixed pulley measurement
In this scheme, the original pulley block is hung on two ends of the special force transmission shaft at both ends, and the two ends of the transmission shaft are press-fitted on two load cells on the trolley platform. This structure can guarantee the accuracy reaches the level of 0.5% FS. The characteristics of this structure are:
(1) The basic structure of the overhead crane is unchanged, the transmission shaft and the two side panels are considered with sufficient safety factor in the design, and the process is subjected to strict quality inspection and has reliable safety performance;
(2) The load cell is installed on the trolley platform of the overhead crane, and has better safety conditions, which can ensure the flatness and levelness of the sensor installation, thereby obtaining high-precision and reliable measurement performance;
(3) The heat treatment of the sensor is convenient, and it can be used in high temperature applications such as lifting a ladle.
(4) All renovation and installation work is carried out on the trolley platform, working conditions are good, installation and future maintenance and overhaul work are more convenient;
 
(5) The parts required for the transformation are organized and produced in the factory. It has good product quality, and the workload of the site and users is small. The spare parts are guaranteed, which is conducive to popularization and application.
2. Dynamic track scale of track type load cell
The scheme is to select the appropriate position on the trolley track of the vehicle, cut off a section of the original track, and replace the orbital sensor. When the trolley passes the track sensor, it automatically performs dynamic weighing measurement. The traditional track type weighing is mostly static. Because the actual operation is difficult to accurately stay at the designated position, the use value of the vehicle is not high, which limits its use. Now the dynamic technology of the factory can automatically and accurately weigh during the driving process, which has no influence on the driver's operation and driving performance, and completely changes the adaptability of this method. The characteristics of this structure are:
(1) The transformation work is simple, and there is no change in the part of the trolley and the lifting mechanism;
(2) It is possible to overcome the weighing error caused by the height of the hook and the length of the wire rope;
(3) The measurement accuracy is higher, the single measurement is better than 1%, and the cumulative accuracy is better than 0.5%;
(4) The signal cable of the sensor and the motor power supply cable of the trolley can be separately routed to reduce the interference caused by frequent start and stop of the motor;
(5) The weighing instrument has dynamic weighing and weighing value retention function. When the weighing is over and the car leaves the sensor position, the display screen can still display the previous weighing result until the next weighing. Automatic recording and printing;
(6) The disadvantage of using the orbital sensor structure is that it is necessary to ensure that the trolley passes through the metering area each time it is metered, which limits its use to a certain extent.
The above two structural forms are the main structural forms of the factory's modified driving electronic scales, and there are some forms, which are also briefly introduced.
3. Install the load cell under the balance bar shaft
This type of structural transformation work is relatively simple, but because of the small force ratio, the stability of the metering performance and the low precision, it is only selected when the measurement accuracy is low or the extra large tonnage is required, and other transformation schem is indeed difficult.After modification, it can achieve an accuracy of about 1% F•S. With this structure, the user needs to provide the following technical information to the factory: the general plan of the car; the assembly drawing of the balance frame; the part drawing of the balance frame.
4. Increase the structure of the platform scale
According to the structure of the trolley to process a platform scale, and the hoisting cylinder, the fixed pulley block and the motor on the original trolley are all moved to the platform scale, and then the platform scale is installed on the trolley, that is, the entire lifting mechanism is moved from the trolley to the platform scale. This type of structural transformation has a large workload. After the transformation, the height of the trolley has increased a lot. It is subject to the limitation of the workshop and lifting equipment, but the weighing accuracy is high, and the precision can reach 0.2% after the transformation.
5. Install two sensors directly on both ends of the original pulley shaft
 
The modification method is to remove the original U-shaped pallet, solder the two sensors to install the small platform, as the sensor installation base, after installing the sensor, press the fixed pulley shaft directly on the sensor, and have sufficient space at both ends of the pulley shaft.
This kind of structure should be modified on site. Due to the limited conditions, the quality of the sensor mounting base is difficult to guarantee, affecting the accuracy, especially the maintenance and overhaul in the future is quite difficult. Only when the user is changing the driving, can this scheme be adopted.
Transmission methods are usually divided into wired transmission and wireless transmission:
First, wired transmission
Wired transmission uses a shielded cable to transmit sensor signals to the meter. This form of signal is stable and is not susceptible to interference, but this form is complicated to install and complicated to repair.
Second, wireless transmission
Wireless transmission is the installation of a transmitting and receiving system, which transmits the sensor to the instrument through radio signals. This form is simple to install and easy to maintain, but the signal is easily disturbed in harsh environments or under strong magnetic fields.