Capital Equipment News

In recent years, R&D efforts by leading excavator OEMs have resulted in the development of energy-efficient excavators and more productive machines. The major technological advancements are positively impacting fuel efficiency and improving productivity. As the excavator is used throughout the day, the monetary benefit through fuel conservation and increased productivity is too high to be ignored, writes Munesu Shoko.

Fuel expense in owning and operating excavators is a constant and accounts for a large chunk of total machine operating costs. With the unpredictable nature of fuel prices and fuel’s absolute necessity for fleet-driven operations, most equipment owners have simply looked at how much fuel they are burning and paid the bill. Recently, technology has changed, and now with the addition of production data, producers can look at their fuel efficiency (how they are using fuel) and know its impact to the bottom line.

At the heart of the efficiency drive in today’s excavators is the introduction of energy-efficient engines by original equipment manufacturers (OEMs.) Martijn Donkersloot, product manager, Dig Assist EMEA at Volvo Construction Equipment, says fuel can account for as much as 95% of lifetime ownership costs.

Volvo driving increased efficiency and productivity

“Volvo boosts fuel efficiency through a highly optimised Volvo Group engine platform and efficient Tier 4 Final technology that includes SCR and light EGR. This combination allows engines to perform at optimum levels, burn less fuel and drive down costs,” says Donkersloot.

According to Steven Faucher, excavation product application specialist for Africa, Middle East at Caterpillar, to provide optimum fuel efficiency and to lower full consumption, Caterpillar’s Next Generation excavators have been designed with some interesting features. “Firstly, all engines use electronic injection to allow more precise control of the injection, and the use of various power modes to adapt machine performance and consumption to the needs of each specific situation,” says Faucher.

Faucher adds that with Cat’s New Generation excavators, engine operating RPMs have been reduced significantly. For example, with the new Cat 320 and 323 models, RPMs come at 1 650, compared with 1 700 and 1 800 on the previous models.

“The injection system has also improved. Our Cat engines use high pressure fuel systems and new injectors that work to achieve lower fuel consumption. In addition, the injection system has been designed to withstand challenges often encountered in Africa and the Middle East, such as a high sulphur fuel content, as well as water and debris mixed with fuel – this can drastically reduce the life of the injectors,” says Faucher. 

Faucher adds that power density has increased in the new Cat Next Generation range. Most of the machines either deliver the same power rating with lower displacement, or retain the same displacement with more power. With larger turbos and reinforced components there is no compromise to equipment durability.

“The engine is clearly an important element in the reduction of fuel consumption, in addition, we have redesigned our hydraulic systems to help make the most of engine power,” adds Faucher.

On one of the latest JCB excavators, the JCB JS305 which is a 31 700 kg tracked excavator fitted with a mechanical 6-cylinder, 7,2 l JCB DieselMAX 672 engine delivering 165 Kw/224 hp of power. “The peak torque comes at 960 Nm at a low RPM of 1 300, and consequently the fine-tuning of matching the engine to the hydraulics has resulted in a very fuel efficient excavator,” explains Andrew Boyers, business development manager – Africa at JCB.

Sophisticated electronics

The introduction of new sophisticated electronics has provided excavator manufacturers with new tools to increase hydraulic system efficiency. Faucher says the addition of electronics allows for better management of engines and hydraulic systems, and so the whole system is more efficient. “Since at Caterpillar we manufacture both machines and engines, we can go a step further and make sure these two systems communicate,” he says.

“For example, with traditional engine control systems, the engine speed is constantly monitored, and if an increase in the hydraulic load causes a drop in the engine speed, the engine control will deliver more fuel to get back to the desired engine speed,” says Laurent Sarignac, excavation product marketing specialist for Africa, Middle East. “Because there is no anticipation, the engine speed fluctuates, and those fluctuations can be quite high. If the engine speed is low, the machine could stall.”

With the latest Cat excavators, Sarignac says both the engine and hydraulic systems work together. “The hydraulic system tells the engine ahead of time to put more fuel and how much to put, and this drastically reduces fluctuations in engine speed. The engine runs at a lower speed without the risk of stalling under load and allows for a greater fuel economy,” says Sarignac.

According to Donkersloot, modern Volvo excavators all have Volvo’s ECO mode, which delivers up to 5% improvement in the machine’s total fuel efficiency – without any loss of performance in most operating conditions. It also features a stop-start engine function to reduce fuel consumption after the machine is inactive for a pre-set period.

Meanwhile, Hyundai Construction Equipment’s (HCE) Intelligent Power Control (IPC) controls power depending on work environments. Its mode can be selected and released on the monitor. On the excavation mode, pump flow can be easily controlled by a lever, reducing fuel consumption.

Speaking about work modes, Sarignac reasons that most of the times the different machine working modes have an impact on engine speed (and therefore the maximum hydraulic flow) and engine response. They require the operator to make a choice between saving fuel and being slow, or working hard and burn more.

“Caterpillar has introduced a Smart Mode operation on its new range of Cat excavators. The mode constantly monitors how the operator is working. If the operator is working slowly and not using maximum flow, the engine speed will automatically reduce slightly to save fuel, and as soon as he resumes fast operations, the engine speed will go back to normal. The system generates about 10% incremental savings without any impact on productivity,” explains Sarignac.

Enhanced hydraulic systems

In addition, manufacturers have found many ways to increase the efficiency of the hydraulic systems through improved valve designs and optimised work modes. According to Boyers, the JS305 has two working modes, Eco and Power.

“The Eco mode offers precise, efficient excavation, resulting in significant lower fuel consumption. The JCB JS305 also benefits from an innovative hydraulic regeneration system which recycles oil across the cylinders for faster cycle times and reduced fuel consumption,” says Boyers.

Donkersloot says Volvo excavators offer the latest in operating sophistication. “For example, pump flow is controlled for combined digging and swinging operations to reduce the flow loss through the overload relief valves, while maintaining digging power and maximum swing torque,” he says.

Faucher says Cat’s Next Generation of excavators is equipped with electro-hydraulic (EH) valves that provide several benefits over pilot-operated valves. These include reduced pressure losses, which help reduce fuel consumption; fewer hydraulic lines on the 320 and 323 Next Generation excavators, resulting in 20% less oil required, thereby lowering long-term operating costs; and positive flow control, which puts energy where needed precisely, when needed.

“Pilot lines and associated filters are no longer required and so the associated maintenance costs are eliminated. Our EH valves are combined with larger pumps to allow productivity to be maintained while the engine RPMs are reduced.  Finally, EH valves allow the integration of solutions to improve job site efficiency, such as Grade Assist and Payload technologies, standard on the Cat Performance Series excavators,” says Faucher.

Machine control systems

Machine control systems, such as digging operation assisting systems, are also taking centre stage. Faucher says over the past 20 years, productivity per worked hour has doubled in manufacturing. Meanwhile, over the same period, productivity in construction only increased by 25%. He is of the view that bridging such a gap can’t be done through traditional ways. “We believe control and guidance technologies are the breakthrough that will allow our customers to achieve unprecedented levels of productivity and operator efficiency gains,” says Faucher.

For example, Sarignac notes that Cat’s Grade with 2D helps operators reach the desired grade quickly and accurately. When engaged, the monitor gives the operator a visual indication of the bucket depth, eliminating the need of a grade checker. The Assist Mode automates the bucket motion. When engaged, the bucket will follow the desired depth and slope, eliminating the guess work, undercutting, overcutting and greatly reducing the need for surveyors.

“Customers can easily upgrade from 2D to Cat GRADE with 3D to create and edit designs with ease and see the front linkage’s full range of motion on a second high-resolution 254 mm touchscreen monitor. The machine automatically compensates for excavator pitch and roll caused by sloping ground conditions,” says Sarignac.

“The excavator’s exact position is known by using GPS and GLONASS systems. The operator can view the digitalised model of the result right in the cab to guide him/her to perform the job without any guess work. To assist with planning and to monitor a job site progress accurately, the system can inform the back office of what has been done to update the ‘live’ project,” adds Sarignac. 

Another great technology introduced by Caterpillar is Payload, an on-board weighing system to achieve precise load targets and increase load efficiency with on-the-go weighing and real-time estimates of the payload without swinging. It enables customers to track daily productivity such as truck target weights and load/cycle counts. Calibration can be performed in a matter of minutes. By combining Payload with VisionLink, production targets can be remotely managed.

When it comes to automation control systems for excavators, HCE has been conducting research and development (R&D) on its Machine Control (MC), a semi-auto levelling operation system, and Machine Guidance (MG), a surveying assistant system. The performance verification shows that overall productivity increases by 30%. The two systems are also effective in additional reduction of costs, such as overhead costs. In the case of the MG system, the commercialisation process is in progress and the MG-applied machines will be launched in European, North American and South Korean markets first. In future, Hyundai will expand to other regions depending on customer demand.

Elsewhere, in 2016, Volvo CE launched its latest machine control technology, Dig Assist. Designed for crawler and wheeled excavators, Dig Assist provides real-time guidance for operators. Using Volvo Co-Pilot – the award-winning in-cab interface with a 10-inch high-resolution touch screen –  allows operators to easily input job specifications and track progress to ensure the job is done right the first time, every time.

“Volvo CE is the only manufacturer that offers such an upgradable and flexible solution to assist excavating. In April 2018, during Intermat Paris, Volvo CE announced that the DigAssist system could now even be upgraded to a true 3D machine control system supplied by Topcon, which is running on the Co-Pilot system,” says Donkersloot. 

Digitalisation to the fore

The global excavator market is also witnessing digitalisation, which is helping the construction industry to work efficiently. As the introduction of 3D CAD ignited the digitalisation of product data and lifecycle management, the augmented reality/virtual reality (AR/VR) technologies are now accelerating the digitalisation of manufacturing (Smart Factory). Today, HCE reports that it has moved significantly on its journey to digital transformation.

The digital integrity of Hyundai’s excavator, better known as Digital Twin, enables the virtual validations, where many performances and requirements are simulated and the excavator can even be manufactured in virtual world. New models’ style can be reviewed with the aid of AR/VR technologies at the early stage of the development process and both fuel efficiency and productivity can be evaluated with the aid of site simulation.

According to Donkersloot, automation, digitalisation and energy efficiency have been identified as important focus areas in the Volvo Group’s Technology Plan. An example of digitalisation within Volvo CE is CareTrack, its very own telematics system.

“CareTrack is a system that gives extensive insight into Volvo machines. By monitoring key information, the system helps to reduce fuel costs, optimise machinery and operator performance, as well as proactively manage service and maintenance; all of which result in efficiency and higher profits,” says Donkersloot.

Meanwhile, Cat Connect LINK technologies, such as Cat Product Link, transmit data wirelessly from Cat machines and turn it into essential insights about the location, status and productivity of the equipment – from fuel burn and payload weights to cycle times and job progress. “LINK brings together all Cat Connect technologies to help customers make timely, fact-based decisions to boost productivity,” concludes Faucher.

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