Cummins Inc.’s QSM 11-L engine installed in the Case 921E articulated wheel loader has improved operating efficiency and reduced fuel consumption with an adjustable power curve feature, according to the manufacturer.
A customized QSM electronic control calibration developed for the 921E loader interfaces with the engine and powertrain via the CANbus control network. The QSM electronic engine control module also recognizes when the 921E is in standby mode and automatically lowers engine speed to 600 rpm for further fuel saving.
The 921E wheel loader was introduced in 2007 to join the Case E Series line with a new cab, a larger bucket capacity payload of 5.75 cu. yd. (4.4 cu m) and upgrades including the Tier III-compliant QSM heavy-duty engine with a 297 hp (221 kW) net output. In March 2008 the 921E was honored with an “Excellence in Equipment Engineering” award from Diesel Progress magazine in the wheel loader category, based on a reader vote.
“We are delighted that the 921E has received this award which reflects the success of the smart engineering work by the wheel loader team at Case Construction Equipment” commented Silvio Novaes, Cummins industrial account executive.
“Cummins customer application group worked very closely with the Case engineers to develop the QSM electronic calibration and feature set for the 921E. With the adjustable power curve and idle standby feature, operators of the 921E can expect to see higher performance and useful fuel savings,” added Novaes.
A digital display in the 921E cab enables the operator to select the most appropriate power curve for the engine — maximum, standard or economy — to precisely match power output, torque and fuel economy to the working activity of the wheel loader.
For fast production activities or when a high breakout force is required, selecting the maximum work mode boosts the engine output to 297 hp (221 kW) net at 1,800 rpm. For operations with lighter materials, using the economy work mode will adjust engine power down to 229 hp (171 kW) net at 1,400 rpm.
When in automatic work mode, the engine self-adjusts for varied operating conditions between a standard power curve with 274 hp (204 kW) output and the maximum power curve with 297 hp output.
With a peak torque of 1,090 ft.-lbs. (1,478 Nm) arriving at 1,400 rpm and a torque rise of 50 percent, the heavy-duty QSM engine provides abundant reserves of strength for a high breakout force and a full-height lift capacity of 29,738 lbs. (13,489 kg), according to the manufacturer.
Built at the Case Construction Equipment plant in Fargo, N.D., the 921E wheel loader has an operating weight of 50,622 lb. (22,962 kg) and is Tier III-emissions-compliant for the North American market and Stage IIIA-compliant for the European market. The QSM 11-L engine is manufactured at the Cummins Jamestown plant in upstate New York.
Enhanced Engine Calibration
The Case 921E wheel loader provides a successful example of Cummins ability to develop enhanced electronic calibrations for improved equipment integration.
“Using Cummins PowerMatch tool set to custom-tailor the engine torque curves and calibration features to the specific operation of the equipment enables us to realize higher productivity and fuel efficiency benefits for the customer,” commented Scott Files, director, Cummins Industrial Application Engineering.
“We closely analyze the duty cycle of the equipment and then match it to the ideal sweet spots on the engine map for maximum torque and minimum fuel consumption. This provides the programming building blocks to create a performance-optimized calibration for the machine.”
“Importantly, Cummins full-authority engine management system with CANbus connectivity means we can fully realize the value of the customized calibration with the machine installation,” added Files.
For more information, visit www.cummins.com.