| February 02, 2011
Case takes on the fuel efficiency challenge once again, and adds a nifty monitor
By Marcia Gruver Doyle
When Case set about to up their game with its C Series excavators, it knew the immediate challenge would be fuel efficiency. Not only did it have to top the fuel efficiency gains of its B Series machines – which had realized a 15 percent increase from previous models – the company would have to overcome the 5 percent fuel inefficiency of the required Tier 4 Interim engine, a cooled exhaust gas recirculation unit with a diesel particulate filter.
• ROPS optional
• Overall cab space increased 7 percent
• Airflow increased 25 percent
• Air conditioning performance increased 8 percent
• 500-hour engine oil change interval
• 5,000-hour hydraulic oil change interval
• 1,000-hour greasing interval
• Gas shock cylinders on service doors and hood
• Rear camera standard
• Optional side cameras
• Optimized mirror placement
• Low house and engine hood for increased visibility
4. Productivity/operating costs
• 5 percent faster cycle times than previous models
• Up to 10 percent fuel savings
• Case Intelligent Hydraulic System
• 6 percent more lift capacity
• 7-inch LED color screen
• Machine data and camera views
• Fuel consumption-per-hour meter
• New line of buckets, couplers and teeth
• Case SmartFit teeth and adaptors decrease change out time to around 15 minutes
• 10 attachment presets for auxiliary hydraulics, five for single-flow attachments and
five for dual-flow
So in order to achieve its goal of gaining a 10 percent boost in fuel efficiency, Case engineers had to come up with a 15 percent total increase. This wasn’t accomplished in one technological swoop, but with a combination of incremental approaches that included improvement of hydraulic pressure loss, advances in engine and pump matching management, spool stroke control and a variety of other approaches (see chart on page 54). As a result, Case says its CX250C excavator, when used in a trenching application, can save more than 3 gallons per hour versus some competitive models.
“As fuel prices start to go up again, there’s more interest in fuel conservation,” says Tim O’Brien, marketing manager for Case’s heavy product line. “Contractor revenue rates are flat, and they’re always looking for ways to save money.”
This fuel savings is part of a total package of C Series improvements now available on the initial three models: the CX250C, replacing the CX240B; the CX300C, replacing the CX290B; and the CX350C, replacing the CX350B. Two of these models have taken on additional weight, jumping them to the next excavator size class.
Fine tuning the hydraulic systems, Case engineers increased cycle time speed 3 to 5 percent from previous models, extra speed that the company says will allow users to fill up to 10 more trucks per shift. According to Case, the following features of the new Case Intelligent Hydraulic System enable both fuel efficiency and improved performance and control:
• Swing relief control, which gives lower flow at the start of the swing operation
• Boom economy control, lowering engine rpms during boom down and swing operation
• Auto economy control, lowering rpms when there’s no control input, and stopping the engine after a set idle time. (Since long periods of idling tends to clog diesel particulate filters, this helps offset that problem.)
• Spool stroke control, providing automatic pressure adjustment in a digging operation.
“All of this gives the operator a better feel and control,” O’Brien says. “The swing relief control, for instance, goes into action when you’re pulling out of a hole and swinging the machine toward a truck to dump a load. Since this is a multifunction action, instead of throwing all the hydraulic oil into the boom or swing circuits during part of the cycle it meters it out and uses the energy more efficiently.”
In the cab
While the outside sheet metal of the C Series doesn’t differ much from the B Series – primarily tweaks required by the increased air flow needs of the T4i engine – the cab is all new. Now an optional ROPS structure, the cab has an inside, doors-closed decibel level of 69, “which we expect to be best in its class,” O’Brien says.
The cab eye-catcher is its 7-inch color monitor, within easy view of the operator and aligned with the cab’s front right pillar. The monitor toggles between two primary screens: machine data or the standard rear-view camera. (With an optional side camera, the camera view can be split between both cameras.)
A full range of information is available in the machine data – or instrument – monitor screen, including engine mode, operating temperatures, and a gallons-per-hour fuel economy meter, much like the miles-per-gallon reading found on today’s cars.
The monitor also takes you through 10 attachment presets for auxiliary hydraulics, with five settings for single-flow attachments such as hammers, and five settings for dual flow attachments, allowing you to quickly change between different types of attachments – and jobs.
“All of our cab changes were based on about 1,000 customer interviews,” O’Brien says. “Between our new rear camera, repositioned mirrors and low house and engine hood, we feel we’ve given users the operational confidence that comes with total 360-degree visibility.” EW