Wheel loaders

Doosan has rolled out of a series of updates to its well-known wheeled loader to produce the DL420 wheeled loader

Specifications of Doosan DL420 wheeled loader

Doosan DL420 wheeled loader

Machine weight 22,300kg
Bucket 3.5m3
Engine 10.8-litre Cummins QSM11 six-cylinder turbo
Rated power 280hp @ 2000rpm
Max power 310hp @ 1700rpm
Torque 1451Nm @ 1400rpm
Transmission ZF 4WG210 automatic powershift 4F, 3R
Working speed range 0-38km/h forward, 0-18.4km/h reverse
Fuel tank capacity 367 litres

   ·Longer torque curve at lower rpm makes it a lot more fuel effective
   ·Doosan’s boom suspension, Load Isolation Method (LIS) makes for a comfortable ride
   ·Straightforward to operate with the throttle and joystick
   ·Additional bucket capacity now accessible

Engineering and performance

The DL420 wheel loader uses the identical fundamental architecture, chassis, transmission, axles and loader arms as the DL400. There is a realignment of bucket capacities, up from the DL400′s 3.9 cubes to four.5 cubic metres.

Most loader pins have increased in diameter from 90-100mm, giving an improve in bearing surface region of practically 50 percent to cope with the extra loading.

The cab is largely unchanged, save for a new instrument panel and supplementary switch gear to permit deeper interrogation of what’s going on inside.

Power now comes from a Cummins QSM11, as identified inside the bigger DL450 and flagship DL500 models, which brings two much more litres of engine capacity over and above the DL400′s QSL9.

Engine and power

This bigger Cummins motor packs a 310hp peak, which occurs at 1700rpm, with rated power falling away to 280hp at 2000rpm. Maximum torque delivery takes location at 1400rpm, where 1450Nm finds its way out of the QSM11′s crankshaft, giving near identical performance to the outgoing model.

At lower rpm though, the torque curve is held up for considerably longer and, combined with the bigger capacity engine, this has the potential to translate into a fuel saving of around 10 percent, claims the firm.

Controls

The DL420 keeps the integration of forward and reverse shuttle control on the loader’s joystick control, and this is furthermore to the normal steering column-mounted twist grip lever, and gives operators greater selection in how machine control is executed.

The twist grip still remains the priority system for direction adjustments, which indicates the operator needs to activate the joystick buttons for shuttle operation.

There is certainly also a kick-down function on the joystick too, giving access to initial gear when climbing steep stockpiles or when you need some extra muscle when loading.

Other characteristics of the cab incorporate an air suspension seat and a steering column that adjusts for reach and rake, plus cab pressurisation, air filtration and climate control.

The cab is carried on viscous, so there’s a generous level of vibration damping and noise suppression. Operator comfort is further enhanced with Doosan’s boom suspension, called Load Isolation Program (LIS).

Beneath the right-hand cab window are two hinged panels delivering access to the cab filtration method. Behind the cab you can find swing-out rear mudguards that aid maintenance access in and around the engine and cooling compartments.

Air filter and exhaust silencer are located over the best of the engine, although the offside contains two diesel filters.

The test

The DL420′s roomy cab is straightforward to access and characteristics several storage areas as well as a cool box. The interior has black and grey plastics all through. The air seat is fully adjustable and extremely comfy too.

Switchgear is laid out in a logical pattern to the correct of the operator, and all are clearly and sensibly marked.

All round vision is superb having a low front windscreen line, well-positioned mirrors along with a reversing camera.

I’ve a option of transmission controls, but favour the joystick forwards/reverse thumb button control program and activate the controls which will enable me to maintain my left hand on the steering wheel and my right hand on the loader joystick.

It’s just so straightforward to make use of, but only soon after it has been activated. Doing so needs the neutral button on the front of the joystick to be pressed initial, along with an authorisation button on the back of the joystick.

And this sequence of events has to be carried out every time the engine is restarted. Ok, so you soon get into the habit and I guess safety sits high on the list. This control pattern stays activated unless you press the neutral button or use the standard shuttle lever.

I opt to preset third on the shuttle lever as my highest gear, then flicked the transmission mode selector round to “automatic gears 2-4″.

My selection means first gear is only accessed utilizing kick-down, and fourth is in no way brought into play, so the box need to spend most of its time working in second and third – and third gear really should keep revs down on load and carry, contributing to fuel savings.

Once transmission options have been produced, driving the Doosan is just a matter of pressing the throttle and toggling between forward or reverse direction arrows together with your thumb on the joystick – it really is that simple. And it works extremely nicely indeed, permitting quick and effortless shuttle modifications, and great modulation too.

The extra bucket capacity now offered on the DL420 comes in handy, and it takes small effort to fill it. A gentle prod of the throttle soon buries the bucket into the largest pile of stone now gathered under among the screen’s discharge belts.

I dab the R button with my thumb and pull the loader away from the stockpile with a secure bucketful of material. Reversing round, I cover the brakes and thumb the F button to smoothly change direction.

All that is necessary is a gentle push of the throttle to ease the loader forward, and then easing off the throttle provokes an early upshift into third gear. The DL glides quickly across website at low rpm.

Doosan’s LIS boom suspension is working gently in the background, adding to the ride high quality too.

As I approach the stockpile and ease off, the transmission glides into second – if I hadn’t been seeking at the dashboard, I wouldn’t have felt it – I then bury the throttle as the loader starts its climb.

Nearing the crest, I raise the loader arms slightly and tip the bucket to empty the first pass onto the heap. A tap of the R button coincides with my left foot hovering over the brake pedal, and I alter direction and ease the DL420 back down the ramp. Adjustable boom height control and return to dig complement the responsive loader controls, making this load and carry task an effortless one.

This loader is much more than comfy working in an envelope that spans 1200-1700rpm, and this is where operators will notice just how effortless the DL420 handles its tasks.

Operating this DL420 feels no different to the DL400 and DL350. The Korean maker has cleverly engineered a feeling of no fuss, no loudly screaming engine and no intrusive hydraulic whines into its DL line-up. This 1 actually is really a quiet machine.

The DL420 has the prospective to be far more fuel-efficient and remains a really competent loader.