Golden Dragon XML6127J78 "Snow Leopard" Test Driving

Golden Dragon, struggling in domestic bus market for years, launched many impressive products. In large bus field, Golden Dragon XML6127-series products are undoubtedly well received in tourism and passenger transport markets, and even appointed to serve "Two Sessions of NPC and CPPCC".

During the test driving, the new-generation XML6127 "Snow Leopard", like ferocious animals, is refreshing to the reporters.

Many domestic bus manufacturers, when upgrading its series products, continue the names instead of the style of the products. From the appearance we can see that its body design is fierce and full of personality: Upward straight lines, start from the trapezoidal edge of the front face, warp the car doors windows and the driver windows on both sides of the front part of the vehicle, link with the lower part of the side-window, and arrive at the tailstock. According to the pursuit of fashion products of the customers, popular elements such as a large area of Chrome trim decoration linking with the headlight at the front part and English sign “SNOW LEOPARD” set at the front side panels were added to “Snow Leopard”.

At the front part of the snow leopard, the overall downwards pressed lines make the vehicle steady. Although the fog lights and headlight position do not change much, the subtle changes make the vehicle more vivid. Reporters also find out those “Snow Leopard” headlights with integrated LED lights, in addition to increasing lighting, are more in line with the current needs of the mainstream. Overall, the design of “Snow Leopard” highlights the beauty of balance. Avant-garde flame of the head light also well reflects the designer’s meaning of innovation.

Same with large trucks, “Snow Leopard” with 49-seats, has through luggage compartment, interior luggage rack, center-board drinking fountains and vehicle-mounted toilet which meets the not only the needs of market organization leasing and also meet the tourism transport requirement in the holiday. The difference is that the car adopts the design of pairs of guide chair at the front door.

Snow leopard interior decoration is concise and elegant. Its beige interior and seats with beige and dark brown leather materials make it economical and practical.

Two inside security sunroof and side windows all used fully enclosed glasses. Built-in sliding windows are optional at the back part of both sides of the vehicle. It is worth mentioning that the seats of the passenger area of the vehicle, same as Golden Dragon”Tianjiao” series, using parallel moving design, pan up to 7cm, increase distance between closing seat, and improving the comfort of long time ride. But the reporter also found that if the both sides of the aisle seats are panning our, the 40cm passageway may seem rather narrow for the passengers to pass. In addition, the seat luggage rack above also use open design. Interior small blocks can prevent sliding in moving. The opening height of the luggage rack is 21cm, which is quite practical.

The distance between last two seat rows is quite wide and the knee pith can reach up to 40cm for the seat layout. So the penultimate row is the most spacious part in the vehicle. But the passenger has to step up to 35cm stairs. The last row of seats are also 35cm, while the distance between the seat and the roof is 162cm, which will not affect the ride comfort.

It not rare that a large-scale vehicle for long-distance passengers transport and tourism is equipped with vehicle-mounted toilet .Compared with similar products of other brands, its bathroom space is larger. According to the observations of the operators, the interior height of most bathrooms of large-scale buses cannot meet the normal passengers’ upright standing needs, thus narrow interior spaces reduce their commodity. In this part, XML6127J78 has really done a good job.

In addition to practical space design, “Snow Leopard” also has good performance in noise testing for its good sealing and sound insulation. According to test data, the lower engine speed is one important reason for its lower noise.

Form 1: Noise Testing at a Constant Speed  dB

Consideration to Operability and Economical Eefficiency

The driving area of “Snow Leopard” is the same as “Tianjiao” which the reporter drives. According to the technical staff, “Snow Leopard” series used the newest G7 platform; inheriting the advantages of “Golden phoenix”, and adopted the concept of modularity and platform, which could use driving area modules, rigid axle air suspension / stiffness bridge spring / independent front axle module (can be used for low entry layout), high / low-floor modules, air suspension, drive axle / leaf spring suspension axle modules, power modules, etc, reduced the species of chassis parts, the research and develop costs and lower the maintenance costs later.

The “Snow Leopard” uses the newest front axle system, while maintaining the same premise guiding mechanism, Swing-airbags, increased lateral stiffness, reduce vertical stiffness. In the suspension set-ups, a good balance was made between load and comfort. The body of the vehicle can maintain good stability when driving and cornering at high speeds.
“XML6127” serials were known for its economic and environmental protecting characteristics. The reporters found that Golden Dragon is constantly reinforcing the character after test drive.

Test drive vehicle is equipped with displacement of 8L Yuchai YC6L330-42 diesel engine, which has maximum power of 243 kW and reaches the maximum toque of 1280Nm at 1200 ~ 1700 r / min, Qianjiang Gear 6-speed transmission and Dongfeng Dana Axle with ratio 3.55. The assembly configuration is characterized by economic and practical. On the one hand, it refers to the purchase costs; On the other hand, it refers to the using costs. Splitter ratio of axles and optimized transmissions which enables the engine to work in the low load region, supplemented with reasonable intake and exhaust system of the engine, can promote the combustion of the fuel and a good working condition of the engine; Compared with traditional fans, the car uses a large air pressure low-energy cooling fan with speed reduced to 200 ~ 500 r / min, for reduced the energy consumption of cooling system and the consumption of the engine accessory ratio.

Different from previous test drive, the test drive vehicles was loaded with sandbags in baggage compartment, representing real loading conditions. In such conditions, the test result is closer to the users’ actual use. In several groups of acceleration tests, the 0～60 km/h acceleration process is shorter, then the acceleration time significantly extends. In actual use, 0～60 km/h acceleration function is demanding.

By testing the speed of each gears (exceptⅠ, Ⅵ), the speed ranges of each gear keep within 20 km / h for different working conditions. When the engine keeps an even speed, the engine works with the speed of 1400～1 700 r/min, which is the economic engine speed range (green area on the disc). In order to better help the driver achieve economic driving, Golden trip fuel-efficient driving system was installed to the vehicle, which is similar to driving style evaluation system that reads rotation speed, vehicle speed, instantaneous fuel consumption, torque through CAN-bus, calculates the gear status matching the current state of vehicle, give the actual gear, make comparison display and gives voice prompts differences. Currently, the function has achieved prompting economic manipulation such as the current gear, up / downshift, instantaneous fuel consumption, the optimal driving state (ECO state), and long time idling. Besides, the system also pays more attention to safety driving. The system will alert the driver when operations like speeding, rapid acceleration / deceleration, neutral glide, was performed. The drivers could learn the current running state of the vehicle and the evaluation of their driving style via 7-inch color LCD screen on the dashboard.

Form 2: Acceleration Time Testing  s    

Form 3: Speed in Each Gear   km/h

In addition, the reporter noted, the model use aluminum wheels, aluminum balloon pistons lightweight hydraulic retarder, aluminum doors and luggage compartment door and other lightweight materials. Llightweight frame, aluminum shell also reduced vehicle transmission quality and contributed to its economy.

Using Technology and Intelligence to enhance Safety

The tested vehicle is equipped with the visible "safe" driving prompts at the dashboard, advanced security measures like forward collision warning system and anti-fatigue driving assistance systems are also readily available.

There are three separate installations of detection and display devices on the dashboard. The forward collision warning system and observing probe of the road deviation warning system which uses dynamic imaging algorithm and communicates with Can-bus to warn the drivers by voice and light alarm are in the middle of the dashboard. The probe of preventing fatigue driving system is on the left of the dashboard. The system used advanced pupil detection technology, and will give voice prompts, take pictures for reference and warn the drivers for safety after finding the driver falling asleep or driving without attention by testing the drivers’ pupil state.
Iron general 2 tire pressure +screen of car backing radar system.

Thanks to its four-wheel disc brakes and ABS, although it is close to its load capability, the vehicle braking distance is comparable conducted from the brake test data. In the auxiliary brake, the engine exhaust valve brake and eddy current retarder improve vehicle driving safety in the mountain. When retarder handle was turned, the speed of the vehicle is reduced immediately under the function of 2200 Nm of braking torque, without using the main brake. Compared with the main brake, the brake force of the retarder lasts longer. The speed will not increase rapidly in inertia, even if the retarder switch is turned off.

In today"s commercial vehicle areas, safety, economy, comfort has become the three major development themes. We must rely much on more advanced electronics and intelligent technology to achieve the goals. From the "Golden Phoenix" to "Snow Leopard", make us see that Golden Dragon accurately grasp the development trend.

Form 4: Braking Distance Testing  m

Form 5: Configuration of Golden Dragon XML6127J78