ABSTRACT
Large haul trucks cooperating with wheel loaders are used on a large scale for horizontal hauling in underground mines of KGHM Polish Copper. Most of the population of LHD trucks are machines with a capacity of up to 25 tons produced by KGHM ZANAM. The latest products include the TB series of trucks: CB4-20TB, CB4-24TB. These are modern machines, equipped with a monitoring system that acquires many operational parameters according to the KGHM data acquisition standard. They are developed in close cooperation with users. Thanks to the data from the onboard monitoring system, machines have been equipped with the Lock-up system, which is closely related to the operation of the gearbox. The article describes the effects analysis of the use of the “lock-up” function in the CB4 20TB machine, based on monitoring data analysis. The Lock-up function is automatically activated by the digital transmission controller under certain conditions. For specified operating ranges, the gearbox mechanically blocks the hydraulic torque converter. This action improves the efficiency of the transmission, which translates into fuel consumption, exhaust emissions, reduction of heat emission by the converter. It improves the efficiency of engine-based braking, reducing the load on the friction-based braking system thus prolonging the lifespan of the brakes and the safety of the users. In the paper, the technical and economic benefits and the improvement of machine operation safety are analyzed. They are expressed by reducing the load on braking systems, reducing the temperature of the oil in the gearbox and reducing the fuel consumption.
