Citroen C4 L technology highlights secret

Citroen C4 L has received much attention in recent months. C4 L is equipped with 1.6T turbocharged direct-injection engine with confidence. The high-end market for compact models, in addition to 1.6T Citroen C4L body structure and materials how? Let's take a look together.

● The manufacturing process adopts laser welding technology The most fashionable welding technology at the moment is laser welding. It seems that the laser welding technology is used to suddenly move the squid. Laser welding technology was first applied in the military field, and it has the advantages of high welding strength, high precision, high efficiency, and small thermal deformation, and was gradually devolved into the civilian automobile manufacturing industry. The C4 L is also a fashionable one, and laser welding technology was adopted in due course.

● Passive safety has bright spots - safety cage body structure ◆ Safe cage body structure and ultra-high strength thermoformed steel plate C4 L's body adopts a safety cage structure, the popular saying is to design the body into a closed loop structure, making it When the top is under pressure or when the body is tumbling, it has a high strength to ensure the living space; the body floor cross and the longitudinal beams are staggered into a mesh structure so that the vehicle can disperse and transmit energy when subjected to impact. At the same time, the closed-loop structure adopts ultra-high strength thermoformed steel with tensile strength of up to 1500 MPa. The horizontal and vertical beams of the floor are made of high-strength steel with tensile strength of 600 MPa, which is among the highest in its class.

â—† The front impact beam of the high-strength aluminum alloy anti-collision steel beam C4 L is made of high-strength aluminum alloy. Its cross-section is closed, and its strength is equivalent to that of a conventional steel beam. The weight is 50% of that of the steel beam. After Citroen C5 and Sega used the same Front collision beam. From the picture of the above-mentioned body structure, it can be seen that the front and rear impact beams have the same color, which indicates that the strength of the front and rear impact beams is similar, but it is not known whether the rear impact beam on the actual car also adopts a high-strength aluminum alloy.

â—† Vehicle-mounted expansion sheets and damping sheets reduce noise The sources of vehicle noise include many noises such as fetal noise, wind noise, etc., which enter the passenger compartment through the connection between the vehicle body and the outside, and spread in the gaps of the sheet metal parts. The C4 L uses expansion sheets. And damper to reduce noise.

● New additions to the powertrain - 1.6T turbocharged direct injection engine + 6AT transmission ◆ 1.6T turbocharged direct injection engine (EP6CDTM) comparison First of all, let's take a look at the comparison of the engine's parameters with that of competing models.

1.6T Engine and Competing Model Engine Comparison Model C4   L   1.6T British Long GT   1.6T new speed   1.8TSI   1.6T Engine Model EP6CDTM LLU EA888 MR16DDT Intake Mode Turbocharged Turbocharged Turbocharged Turbocharged Inline Mode In-cylinder Direct Injection Multipoint Electronic Injection In-cylinder Direct Injection In-cylinder Direct Injection Maximum Power 163 hp (120 kW) / 6000rpm 184 hp (135 kW)/5800 rpm 160 hp (118 kW)/5000-6200 rpm 190 hp (140 kW)/5600 rpm Maximum torque 240 Nm/1400-4000 rpm 235 Nm/2200-5600 rpm 250 Nm /1500-4200rpm 240Nm/m/2400-5200rpm Cylinder head material Aluminum Aluminum Aluminum Aluminum cylinder material Aluminum Iron Iron and aluminum Special technology Intake CVVT No inlet VVT Dual C-VTC

Although the 1.6T engine in these models is not the most outstanding data, but its data also belong to the ranks of the mainstream supercharged engine, power is also the same with the Volkswagen 1.8TSI engine, the turbine delay is also the lightest, 1400rpm can output the maximum torque. In addition, after the domestic Citroen series models are naturally aspirated engines, the new 1.6T engine is also considered a breakthrough.

â—†Technical Highlights of 1.6T Turbocharged Direct Injection Engine (EP6CDTM) In terms of power, the biggest highlight of C4 L is the deployment of one of Ward's top ten engines jointly developed by BMW and the symbol Citroen Group, 2007-2012. The EP6CDTM turbocharged engine with the international annual engine honor for six consecutive times was also used in the BMW MINI and Peugeot 207cc (tuning is different). At present, many opponents have joined the small-displacement booster engine to improve their competitiveness. This time, the C4 L is equipped with this EP6CDTM 1.6L turbocharged engine and will target its opponents (the new Sagitar, Hideo GT, etc.) and is ready for a big fight.

Focusing first on the engine as a whole, the EP6CDTM uses a high-pressure cast aluminum cylinder and an integrated cast aluminum cylinder head to improve heat dissipation and reduce the overall weight by one-third. The highly rigid cylinder also effectively suppresses engine vibration and noise. All-aluminum engines have great advantages over their competitors' cast iron cylinders.

Since BMW and the BMW jointly developed the engine and naturally applied BMW's technology, the Twin scroll technology is actually a single-turbo dual-scroll tube technology that BMW has always adopted. The exhaust pipe with a 4-2 distribution reduces the exhaust gas interference. In addition, the double scroll can also increase the gas flow rate at the exhaust end, which helps to reduce the turbine's delay. Thanks to this, the engine can output 163 horsepower (120 kilowatts) at a speed of 6000 rpm, which can be achieved from 1400 rpm. 240 Nm of maximum torque.

The EP6CDTM also uses Bosch's in-cylinder direct injection system to achieve homogeneous combustion with a maximum injection pressure of up to 120 bar, better atomization and better fuel economy. The latest official fuel consumption data released recently shows that the comprehensive fuel consumption of the C4 L 100km is 7.5L.

The CVVT continuously variable intake timing system can continuously delay or advance the intake phase within a range of crankshaft rotation angle of 70 degrees to ensure the efficiency of the engine under different operating conditions, which is conducive to the improvement of the engine's low-speed torque performance. Can reduce fuel consumption and emission quality. The camshaft is also driven by the timing chain. Compared to the traditional timing belt, the chain will not have skipping and the transmission is more reliable.

The oil pump of the general engine works with a constant displacement, and the engine will have excess oil at high speeds. In order to eliminate this phenomenon, the EP6CDTM engine uses a variable-displacement vane-type oil pump that can fully meet the engine oil demand at low speeds, effectively reducing overshoot at high speeds, and improving engine fuel economy. When the engine is running at a high speed, the temperature inside the cylinder is very high. Excessive temperature easily affects the life of the piston and can also cause engine knock. The piston independent cooling system can solve these problems well.

The engine accessory is driven by a belt, which inevitably increases the engine load and increases fuel consumption. Some high-end brand models use electromagnetic clutch pumps (ie, an electromagnetic clutch in the pump). The price of such pumps is relatively high. Citroën chose a more "grassroots" approach to achieve the disconnection and integration of the pump: a movable friction wheel is added between the engine pulley and the pump drive wheel. When the cold car starts, the pump drive is disconnected and the pump stops working. It can make the engine warm up quickly and reduce the fuel consumption. When the water temperature reaches normal, the pump drive is combined and the pump works normally. Of course, these water temperature signals are all sent out by electronically controlled thermostats. Electronic thermostats are more accurate and sensitive than traditional paraffin thermostats, and they work better with clutch pumps.

In addition, the 1.6T engine also uses micro-groove machining technology to enhance the oil storage capacity of the bearing to ensure efficient lubrication performance, accelerate the early running-in between the bearing and the crankshaft, and prolong the service life of the bearing.

â—† EC5 1.6L, EC8 1.8L naturally aspirated engine technology highlights The C4 L is also equipped with two naturally aspirated engines, EC5 1.6L and EC8 1.8L, all meeting the national five emission standards. EC series engines also use the intake CVVT continuously variable timing system, which can adjust the intake air phase according to the engine operating conditions within a range of 46 crankshaft rotation angles. The above-mentioned variable displacement oil pump and piston independent cooling system are also applied to EC series engines.

EC5   1.6L Naturally Aspirated Engine Intake Mode Natural Suction Mode Multi-point EFI Maximum Power 114 hp (84 kW)/6000 rpm Max Torque 150 Nm/4500 rpm Cylinder Head Material Aluminum Cylinder Material Cast Iron Specific Technology Inlet CVVT

As we all know, the opening of the valve is driven by the camshaft, and the friction between the cam and the valve stem is very frequent. The valve stem of EC series engine is coated with DLC coating (diamond-like coating), which has diamond-grade hardness, can effectively improve the wear resistance of the top cylinder surface, reduce the friction system of 0.02-0.1, and give more power. Used to do work.

◆ "Lateral Love" - ​​Aisin 6AT gearbox has been used by CVT, 6AT and 6-speed dual-clutch gearboxes in the competition. Citroen's 6AT seems to be a bit late. The C4 L is equipped with The Aisin second generation F21-250 (TF-70SC) 6AT gearbox (1.8L and 1.6T engine with 6AT) is also considered to be standing on the same starting line with everyone. This transmission uses the TF-80SC's hydraulic distributor and electronic control unit with economical, sports and snow modes. The Citroen C5 uses this transmission. 1.6L, 1.8L two naturally aspirated engines are also equipped with 5-speed manual transmission.

Gearbox Matching 1.6L naturally aspirated engine 1.8L naturally aspirated engine 1.8L naturally aspirated engine 1.6L supercharged direct injection engine 5 speed manual   5-speed manual 6-speed automatic 6-speed automatic ● Interior highlights - environmentally friendly materials, seat design Interior odor will directly stimulate the driver, and even toxic. The C4 L interior material is subjected to Duolun VOC analysis to ensure that the smell of the vehicle is above the standard.

The contour of the seat, the geometry of the seat surface, and the use of materials all affect the comfort of the seat. During the design phase, engineers use seat pressure distribution analysis to explore the forces of the hips and legs of the human body to improve seat comfort more specifically.

● Tyre air shortage in the direct tire pressure monitoring system can lead to insufficient vehicle power and increased fuel consumption. Severe abnormal tire pressure can also cause traffic accidents. Citroen C4 L is equipped with a pressure sensor in each tire to constantly monitor the pressure of each tire, and the data can be intuitively displayed on the screen in the car. When an abnormality occurs, it can be automatically alarmed. The indirect tire pressure monitoring system uses the change of the wheel speed with the rolling reduction, and it cannot detect the specific wheel of the abnormal pressure.

● Inheritance and Innovation The rear windshield of the C4 L inherits the design concept of the C5, which uses a hyperboloid glass. From an aerodynamic point of view, it can provide greater downforce at high speeds and improve driving stability. It can be used in practical applications. Increase the size and opening angle of the trunk opening.

Citroen C5 uses a central fixed steering wheel, the middle of the control area does not turn with the steering wheel, but this innovative technology does not seem to be recognized by users, many consumers feel very uncomfortable. Today, C4 L gave up this technology and returned to the traditional multi-function steering wheel.

Perhaps you, like me, are speeding when you are driving in a loop or on a high speed road. The C4 L's LVV speed limit function solves this problem. You only need to set the limit speed on the multi-function steering wheel, and the ECU will limit the maximum speed of the vehicle according to the command.

Full text summary:

Although the data of the 1.6T turbocharged direct injection engine is not so outstanding, it can be considered as a mainstream position in the high-end compact market. With the "late" 6AT gearbox, Citroen is back to the same starting line. The body structure and materials are also at the forefront of the market, and vehicles are equipped with some practical configurations. However, the specific competitiveness, but also wait for the official listing price.