Higher injection pressure saves fuel and also increases performance and torque. “Over the next decade, the vast majority of diesel engines will manage with injection pressures of around 2,000 bar. Although 3,000 bar is not unrealistic, it will be limited to racing cars and high-performance diesel engines.” (Dr. Markus Heyn, President of the Diesel Systems division at Robert Bosch GmbH)

Figure 1 Diesel facts. The diesel engine offers the ideal combination of fuel economy and driving pleasure, particularly appreciated by business travellers and commuters.

Common-rail diesel: The CRS3-25 common-rail system features Bosch’s first piezo injector for passenger vehicles that works with an injection pressure of 2,500 bar. With their higher injection pressure, the new piezo models from Bosch are at the technological vanguard. The optimized fuel injection system atomizes the fuel more finely, improving combustion. Lower consumption is just one advantage of this technology.

By way of comparison: The pressure generated by a common-rail system is roughly equivalent to the pressure a 2,000-kilogram rhinoceros would exert standing on a fingernail. The compressed fuel is then finely dispersed at the speed of a supersonic jet.

Enhanced performance: A higher injection pressure generates greater specific power and increases torque. This is why increasing an engine’s injection pressure makes it more powerful: the time available for combustion is extremely limited as soon as an engine is running at full load and high engine speed. This means the fuel must be injected into the engine very quickly at high pressure in order to achieve optimum power yield.

Turbo: The more air there is in the combustion chamber, the higher the injection pressure must be. A large amount of fuel has to be introduced within a short space of time to achieve a combustible air-fuel mixture. Multiple turbocharged engines – particularly bi-turbo and tri-turbo models – benefit from injection pressures in excess of 2,000 bar.

Emissions: A higher injection pressure is a key factor in reducing an engine’s untreated emissions. Indeed, in compact-class vehicles it can often even help to avoid the need for exhaust gas treatment. The greater the injection pressure, the more finely both the injector and injection nozzle can be constructed. This improves atomization and results in a better air-fuel mixture, meaning that optimum combustion is achieved and no soot can form.

Systems competence: A higher injection pressure requires more than just a re-engineered injector. With its comprehensive diesel systems competence, Bosch is able to assemble a finely tuned system comprising not only the control unit, but also the fuel pump, the common-rail system and the injector.

Figure 2 Bosch CRS3-25 with 2,500 bar pressure. A higher injection pressure requires more than just a re-engineered injector. With its comprehensive diesel systems competence, Bosch is able to assemble a finely tuned system comprising not only the control unit, but also the fuel pump, the common-rail system and the injector.

Development of injection pressure – Bosch began with 100 bar

up to 100 bar

Goal at the start of development in 1922

over 100 bar
First series-production inline injection pump
(MAN truck, 1927)

300 bar
VE distributor injection pump (VW Golf D, 1975)

900 bar
Axial-piston pump (Audi 100 TDI, 1989)

1,500 – 1,750 bar
VP 44 radial-piston pump
(Opel Vectra, Audi A6 2.5 TDI, 1996; BMW 320d, 1998)

1,350 bar
Common rail (Alfa-Romeo 156 2.4 JTD, 1997)

2,050 bar
Unit injector system (VW Passat TDI, 1998)

over 2,000 bar
Common rail with piezo injector
(first deployed in the Audi A6 3.0 TDI, 2003/4)

2,500 bar
CRS3-25 common-rail system (available in series-production vehicles as of 2014)

On January 7, 1902, Bosch was granted the patent for a high-voltage magneto in combination with a spark plug. This invention was the first to guarantee reliable ignition of the air-fuel mixture in internal combustion engines, meaning Bosch spark plugs helped to achieve a breakthrough in the automotive industry. For 111 years, Bosch spark plugs have played an essential role in the development of high-performance, economical and environmentally-friendly engines. Today, virtually all vehicle manufacturers put their trust in Bosch spark plugs in their original equipment. Boat engines, jet skis, garden and forestry equipment, stationary gas engines, water pumps and emergency generators also use Bosch spark plugs.

• Current Bosch product range comprises around 1250 types of spark plug
• Virtually all vehicle manufacturers now place their trust in Bosch spark plugs
• Modern spark plugs protect the engine and catalytic converter

In the last 111 years, Bosch has developed over 20,000 different types of spark plug and produced over 11 billion spark plugs in total. In addition to production in Germany, spark plugs are also currently being manufactured at Bosch locations in Brazil, China, India and Russia. Working closely with engine manufacturers worldwide, Bosch engineers have consistently developed the spark plugs since their conception. The current Bosch product range comprises around 1250 types of spark plug with 26 different electrode layouts. Thanks to innovative material combinations, complex construction details and state-of-the-art manufacturing techniques, Bosch spark plugs enable clean and efficient fuel combustion in gasoline engines and protect both the engine and the catalytic converter. Among motorists, Bosch spark plugs have been synonymous with quality and reliability for many years.

Figure 1 111 years of spark plugs

Overview

• 1902: Bosch granted the patent for a high-voltage magneto in combination with a spark plug
• 1914: First Bosch spark plug factory opened in Stuttgart.
• 1927: “Heat range” concept introduced by Bosch – Bosch still uses the same standard measurement for a spark plug’s thermal productivity today. It is important for ensuring optimal calibration in each engine
• 1939: Spark plug factory opened in Bamberg.
• 1968: One billion spark plugs produced by Bosch
• 2012: Eleven billion spark plugs produced by Bosch
• 2013: 111-year anniversary of Bosch spark plugs

Bosch pollen filters

Millions of people suffer from pollen allergy. One out of six suffers from itching, sneezing attacks and hay fever – especially in spring. This can lead to dangerous situations while driving, since a sneezing driver is a blind driver. That’s why people suffering from pollen allergy should keep the windows closed while driving. To prevent the allergenic pollen to get into the car through the ventilation or air-conditioning systems, most cars are nowadays equipped with a cabin filter. In an effective manner it keeps pollen, dust and even pollution out of the passenger compartment. Nevertheless – just as with any filter – the effect of the cabin filter also decreases once the filter capacity is exhausted.

Figure 1 For some of us it’s that time of year (Source: Bosch)

“Cabin filters cope with a restricted amount only and should thus be replaced once a year”, the patient counselling of the German Allergy and Asthma Association recommends. “In doing so, a trained specialist workshop should clean the filter surroundings, the channels and the evaporator at the same time”.

Figure 2 Cutaway picture of an activated carbon cabin filter: 1 Preliminary filter, 2 Microfiber fleece, 3 Filter, 4 Activated carbon. (Source: Bosch)

In order to achieve an optimum filter effect during the critical pollen season, the cabin filter should be replaced already in early spring, Bosch filter experts recommend, too. In this context exchanging the standard filter by an activated-carbon filter is well worth it. Its activated carbon layer – made out of coconut shells – absorbs gaseous pollution thanks to its spongy structure. In addition to pollen and fine particulates, Bosch activated-carbon cabin filters even retain stinking and harmful gases such as ozone or nitric oxide. Any workshop can quickly and easily replace the filter or the standard filter by an activated-carbon filter.

Additional information can be accessed at www.bosch-automotive.com

Introduction

The electric (or electronic) parking brake, also known as an automatic parking brake (APB), is a function offering the driver increased comfort and convenience. In addition, as the hand lever is not used, car manufacturers have more freedom of choice as to where they site the operating parts within the car.

Features such as hill- or auto-hold are also possible with an EPB. Hill-hold stops the car rolling away accidentally when standing still or setting off. Auto-hold keeps the brake pressure applied after the driver releases the pedal. If the ABS sensors detect any movement the pressure is increased. If the accelerator is pressed (or the clutch released on a manual) the brakes are let off.

There are two main systems in use as described below; namely the cable-pull and electric-hydraulic type. Both methods include a visual warning light on the dashboard. The second of these is now the most common. A third full-electric type will start to be used in the near future.

Types of EPB

Figure 1 Cable pull system (Source: Landrover)

Cable-pull systems

The cable pull system is simply a development of the traditional lever and cable method. As the switch is operated, a motor, or motors, pull the cable by either rolling it on a drum or using an internally threaded gear on a spiral attached to the cable. The electronic parking brake module shown as figure 1, also known as the EPB actuator, is fitted to some Range Rover and Landrover models. The parking brake can be released manually on most vehicles. After removing a plastic cover or similar, pulling a wire cable loop will let off the brake.

Electric-hydraulic caliper systems

These types are usually employed as part of a larger control system such as an electronic stability program (ESP).

Figure 2 Electric-hydraulic parking brake caliper (Source: Bosch Press)

When the driver presses the switch to activate the parking brake, the ESP unit automatically generates pressure in the braking system and presses the brake pads against the disc. The calipers are then locked in position by an electrically controlled solenoid valve. The caliper remains locked without any need for hydraulic pressure. To release the brake, the ESP briefly generates pressure again, slightly more than was needed to lock the caliper, and the valve is released. This system is show as figure 2.

Full electric drive-by-wire systems

The drive-by-wire system shown in figure 3 was developed by Continental. It uses an electric motor (3) and gearbox to apply pressure on the pads and therefore on to the disc (7). A key component is the parking brake latch. This is like a ratchet and it prevents the pressure in the piston from rotating the motor – and it therefore keeps the brakes applied.

Figure 3 Electric drive-by-wire brake caliper components. 1 Electric motor, 2 Gearbox, 3 Spindle piston, 4 Parking brake latch, 5 Brake pads, 8 Brake anchor, 7 Brake disc. (Source: Continental)

Control system

The diagram shown as figure 4 is a generic layout of an EPB system. It is from a company known as Allegro Micro Systems and they provide a wide range of motor driver, power management, and Hall-effect sensor ICs.

Figure 4 EPB general system layout (Source: Allegro Micro Systems Inc.)

Like all other similar layouts, the electric parking brake system has inputs and outputs. The control switch and wheel position sensors being the main inputs but also shown in figure 4 is a current sensor in the motor supply. This allows monitoring of motor performance and torque. The outputs are the motor and a warning lamp. On most systems there will also be a diagnostic output for reading by a scan tool either directly or via the CAN bus.

Roller testing

NOTE: Always check and follow specific instructions and specifications provided by the vehicle manufacturer.

Testing the parking brake on rollers is possible on both systems. Cable pull types can be tested much like ordinary hand or parking brakes. But there is a risk of locking the wheels. Some manufacturers have test modes – so double check!

The types with caliper motors can also be tested on rollers but the procedure is slightly different. Most of the caliper-motor systems (TRW for example) have special software incorporated in the ECU for brake testing. When the car is put on a rolling road and the rear wheels are driven by the test equipment, the ECU detects this as a test situation because the rear wheels are moving and the fronts are not. It therefore puts the system into test mode. If a multi-function display is used on the vehicle dashboard, it will display an appropriate message. The technician can then operate the handbrake-switch. The ECU applies the electric parking brake with enough force to obtain a reading on the roller brake tester. The wheels should not lock. After the test is complete the rollers are stopped and the switch is released. When the switch is activated again, the brakes are re-applied in the normal way and the wheels will be locked.

Summary

The key drivers for enhanced systems such as the EPB are increase functions, comfort and safety as well as greater freedom for vehicle designers.

The addition of electrical functions to the normal hydraulic caliper is currently (2013) the most common. However, brake-by-wire is just round the corner and development is unlikely to stop…

‘When “The Terminator” came out in 1984, it involved an annihilating future wherein machines had risen against us. Having arrived in that future, we now know better. The machines won’t kill us. But they are removing us from the equation.’

Read more here: http://www.automotive-technology.com/knowledgebank/articles/cars-communication.html

50 million injection valves and 10 million high-pressure pumps manufactured at Bosch

Rapid market growth continues

• Gasoline direct injection is key for economical engines
• Up to 15 percent lower fuel consumption and CO2 emissions
• Global manufacturing network

Gasoline direct injection systems are continuing to enjoy rapid market growth. Thanks to this, the Bosch Gasoline Systems division is celebrating a production milestone in November 2012: 50 million gasoline injection valves from the HDEV5 series and 10 million high-pressure pumps from the HDP line have been manufactured. Only last year, the 25 millionth injection valve and the 5 millionth high-pressure pump rolled off the line in the Bosch global manufacturing network. Within a year, then, the total number manufactured has doubled. The HDP went into series production in 2006 and initially featured in GM’s Ecotec engines. The HDEV5 had its premiere that same year in the PSA/BMW Prince engine.

Bosch: pioneer in gasoline direct injection

The supplier of technology and services is regarded as a pioneer in the area of gasoline direct injection. Bosch launched this technology in 1951, initially for the two-stroke engine of the compact Gutbrod Superior car. Three years later, gasoline direct injection for four-stroke engines debuted in the legendary gull-wing Mercedes-Benz 300 SL. This paved the way for the development of passenger-car gasoline engines that combined higher performance with lower fuel consumption and emissions. When gasoline direct injection is used in combination with turbocharging and electronic engine management, it results in an approximately 15 percent reduction in fuel consumption and CO2 emissions, and achieves this without sacrificing torque or performance.

The combination of turbocharging and gasoline direct injection also permits downsizing – that is, engines with smaller displacements which consume less fuel and emit less CO2. Since ever more automakers are opting for downsizing, the international market for gasoline direct injection systems is steadily growing. “We estimate that by 2015, the share of gasoline direct injection will triple to 18 percent of all vehicles manufactured worldwide,” says Dr. Rolf Bulander, the president of the Bosch Gasoline Systems division.

Injection pressures up to 200 bar

If mixture formation is homogeneous, the HDEV5 high-pressure injection valve makes a major contribution to optimum, and thus fuel efficient, combustion. Up to seven individually positioned injection holes enable the spray pattern to be flexibly adapted to different engines. Moreover, the high-pressure injection valve and the high-pressure pump are designed for system pressures of up to 200 bar. The HDP5 high-pressure pump is characterized by its compact dimensions and its light, 750-gram weight. Thanks to the use of stainless steel, the current components of the gasoline direct injection system are highly resistant and can handle fuels such as ethanol, which makes them suitable for worldwide use. Bosch currently produces high-pressure pumps and injection valves at its lead plants in Bamberg and Nuremberg (Germany), as well as in Bursa (Turkey), Wuxi (China), Charleston (U.S.), and Korea.