At MINExpo 2021, Komatsu introduced a new underground hard rock drilling machine with several advanced features originating from customer input and collaboration. Unlike previous models, it includes hoseless booms. The ZJ32Bi is a battery-electric, medium-class jumbo which, according to the company, is built on a common platform for increased user adoption and efficient training.
A drilling jumbo consists of one or more hydraulically powered rock drill carriages, attached onto a chassis which holds the operator cabin and the engine or other powerplant. Drilling jumbos are usually used in underground mining if excavation is done by drilling and blasting. They are also used in tunneling, if rock hardness prevents the use of boring machines.
The new machine offers a standard reduced hose configuration — only six per boom — with a hoseless option. The hoseless boom permits all fluid and communication transfer inside of the boom cylinder, offering a potential game-changer in terms of automation and productivity. A hoseless boom also eliminates the need to account for hoses in automation algorithms and eliminates wear between the inner and outer boom tubes for improved drilling accuracy over time.
Because of the common platform of the ZJ32Bi, it essentially becomes a multifunction drilling machine. Other key features of the ZJ32Bi include:
• An intelligent control system that allows for semiautonomous functionality or operator augmentation.
• A modular battery-electric driveline with up to 130 kW (65 kW base) of onboard energy for the demanding tram cycles and rigorous hard rock mining.
• A newly designed fully enclosed operator cabin with advanced noise reduction, operator ergonomics, and double-curved glass with a focus on air cleanliness
• Lightweight, durable feeds in fixed and double telescopic versions, featuring cast polyurethane components to reduce weight and help improve longevity.
The unit is also available in a diesel model (ZJ32i).
While Komatsu did not announce technical specifications for the ZJ32Bi at MINExpo, the related ZJ21 includes jumbo hydraulics for bolter head and boom movements. The carrier hydraulics includes variable displacement piston pumps with load-sensing, closed center circuit design for high efficiency. Oil tank volume is 48 gallons. Steering hydraulics uses a variable displacement piston pump with load-sensing, closed center circuit design; stick steering with a direct-acting control valve; and two double-acting steer cylinders. The totally enclosed service brake is hydraulically-applied, spring-released on front and rear axles with automatic brake application.