Intelligent bulldozers provide productivity boost

New smart dozers provide faster working and greater efficiency - Mike Woof reports

Both 178 Caterpillar and 2300 Komatsu are making key moves in offering intelligent bulldozing capabilities on their latest machines. In the medium-sized bulldozer market, both companies have sophisticated new models that will increase both productivity and finish quality, while lowering running costs for the user.

Caterpillar’s D6K2 bulldozer represents a significant step ahead for the firm’s equipment range, featuring the latest low emission engine technology. This medium sized dozer retains the hydrostatic drive of the earlier D6K model but offers additional productivity, while actually being more economical on fuel. Jean François Villar works at Caterpillar’s Grenoble plant where the machine is manufactured and he said that the 13.3tonne D6K2 is intended as a dozer for fine grading operations.

A number of the improvements are straightforward upgrades of the basic design. At 3.2m the blade is 10% wider than for the previous model and Villar said, “We increased the width of the blade by 32cm and we increased the height of the spill plate.” And he added that for the 13.95tonne low ground pressure (LGP) model, a 3.68m wide dozer blade is also available.

An innovative feature comes in the shape of a gyroscope mounted underneath the blade that forms part of a system intended to limit quick variations in blade movement. This senses the movement of the blade and helps limit over-compensation to height variations by inexpert operators, which can otherwise cause uneven surfaces and especially in fine-grading operations. This does not replace the AccuGrade machine control system however and serves as an additional tool to ensure finer finishing and Villar added, “Behind the blade we put in sensors to measure the force.”

The undercarriage has been beefed up to extend working life and reduce wear and tear. This is an important point for a dozer as undercarriage maintenance requirements and the life of the individual components forms a key factor in the uptime and running costs for the machine. The machine has eight bottom rollers and an additional carrier roller on the undercarriage. It is fitted with Caterpillar’s SystemOne long life bushes, which increase track wear life to up to 5,000 hours in normal operating conditions.

Meanwhile the new low emission version of the C6.6 engine also offers major reductions in maintenance needs and fuel consumption. The exhaust has a passive system for catching NOX and soot particles, a key feature as this has no need for periodic regeneration and this is said to last the life of the machine.

The diesel is rated at 97kW and as the engine operates at lower rpm than the unit in the earlier D6K, it uses less fuel. Villar said, “We save around 5-20% of fuel in some applications, compared with the old machine. You can select the eco-mode in either forward or reverse.”
Meanwhile 262 Komatsu Europe International is now introducing the D61EXi/PXi-23 to the European market. This machine is highly important as it is one of Komatsu’s first intelligent machine control machines and is equipped with fully-automatic blade control. This allows the D61i-23 dozer to carry out both roughing out and finish grading in automatic mode.

The machine control systems are embedded in the dozer’s hydraulics in the factory, a significant move as this means that there is no need for the user to fit masts that carry the various receivers. The 342 Topcon machine control technology allows highly accurate working on-site, with a massive reduction in the need for reworking and this is integrated with Komatsu's proprietary KOMTRAX machine tracking system.

Linking the machine control technology with the KOMTRAX system will offer customers significant gains as it will allow a much more efficient working cycle as well as more effective fleet management. Access to real-time machine data means that the contractor can use the internet to track work progress including the amount of soil dozed at jobsites. The embedded technology can be used with the latest sophisticated software also, to further improve earthmoving efficiency.

The add-on components for a machine control system that would usually be mounted on the blade are now replaced with a factory installed cab top GNSS (Global Navigation Satellite System) antenna, an enhanced inertial measuring unit (IMU+), and with stroke sensing hydraulic cylinders. These components are installed at the Komatsu manufacturing facility during machine assembly, along with the machine control monitor and controllers mounted inside the cab. According to Komatsu this integrated sensor package is more robust and also eliminates the need to install and remove GNSS antennas and cables from the blade. When rough dozing, the automatic blade control monitors blade load and adjusts blade elevation, to minimize track slip and perform high-efficiency dozing. As work progresses closer to the target finish grade, the automatic blade control adjusts to deliver finish grade performance with high-level precision. When compared to conventional add-on machine control systems, an increase of up to 13% in efficiency
can be measured when using Komatsu’s technological innovation in combination rough dozing.

Meanwhile for the driver, selectable dozing modes allow the system response to be tailored to the operation, optimising performance. Similarly, blade load settings are adjustable between presets to match the conditions. From pass to pass, this intelligent control system can be left with the automatic blade control engaged as it automates lowering of the blade at the start of a pass and raises it at the end.

As the machine is driven, its cab-top GNSS antenna collects surface data by measuring the elevation. The stroke sensing angle cylinder also measures the actual angle of the blade for high precision grading accuracy on cross-slope. At the same time, the KOMTRAX package sends machine operating information to a secure website. Data such as operating hours, fuel consumption, location, cautions and maintenance alerts are relayed to the internet application for analysis.

In addition, the KOMTRAX fleet monitoring system increases machine availability, reduces the risk of machine theft, allows for remote diagnosis by the distributor, and provides other information to improve efficiency and productivity.

Other improvements include longer track-on ground standard (EX) and low ground pressure (PX) models for additional flotation. Depending on the specification, operating weights can range from 17.74-18.66tonnes, while the machine is powered by a diesel rated at 127kW.

Chinese dozer development

1171 Shantui continues to develop its dozer line, following on from the unveiling of the top-of-the-range SD90 model late last year. The 105tonne SD90 with its 708kW diesel features a 45m3 blade and is still in development, with a launch date still to be announced. However the company is now offering the latest version of its proven SD32 platform, the SD32PLUS bulldozer.

This machine is part of the new PLUS range of improved bulldozer models Shantui is now offering, featuring upgraded operator controls, new 196 Cummins diesels, and more robust hydraulics. The company claims that its SD32PLUS is its most technologically advanced bulldozer so far. The SD32 models weigh in at just over 37tonnes and are powered by diesels rated at 235kW. Meanwhile the SD22E extended track bulldozer is a modification of the firm’s existing SD22. Performance and reliability have been increased while fuel consumption and maintenance needs have been reduced.

The machine’s extended track length helps reduce ground pressure, although the machine is said to offer high manoeuvrability. The SD22E is designed for earthmoving operations on soft ground and is available with various engine options including units from 2731 Weichai Power, Weichai Deutz, Cummins and Shangchai. This 24.6tonne dozer is powered by a 162kW diesel.