Piezo Direct Fuel Injection **![](0logo.gif)** **[rexresearch.com](../index.htm)** --- **Georg BACHMAIER, Georg / Bernhard GOTTLIEB** **Piezo Direct Fuel Injection** --- [**http://www.continental-corporation.com/**](http://www.continental-corporation.com/) ![](piezodfi.jpg) --- [**http://www.earthtimes.org/articles/show/continentals-direct-injection-technology-saves,622656.shtml**](http://www.earthtimes.org/articles/show/continentals-direct-injection-technology-saves,622656.shtml) 14 Nov 2008 AUBURN HILLS, Mich., Nov. 14 /PRNewswire/ -- Who would have thought that a forty-five millimeter long invention could improve engine performance, reduce emissions and fuel consumption by twenty percent? Continental, one of the world's largest automotive suppliers, developed such an innovative technology and is the first to mass-produce the gasoline Piezo direct injection system. "We are very proud of our Piezo direct injection technology and the contributions it brings toward our goal of reducing fuel consumption and emissions," said Kregg Wiggins, Senior Vice President Powertrain, Continental NAFTA - Region. Continental's Powertrain division is the pioneer of Piezo injection technology. It is part of the wide range of products that Continental supplies today -- from optimized tires, electronics and mechanical components -- that combined could reduce fuel consumption by up to 40 per cent. Production of the first generation of Piezo injectors for diesel engines began in 2000. Production of gasoline Piezo began in 2006. Continental is the market leader in Piezo direct injection systems. "We believe there will be a significant demand for direct injection technology moving forward as a direct result of the benefits to the end consumer," said Wiggins. "The Piezo direct injectors offer our customers the latest technology to significantly reduce carbon dioxide while simultaneously taking fuel economy to new levels." This completely integrated system takes full advantage of the fast switching speeds and precise fuel metering of Piezo technology, making it possible to use a spray-guided stratification combustion process in a gasoline engine for the first time ever. During the combustion process, gasoline is directly injected into the combustion chamber near peak pressure to better utilize the fuel, resulting in a combustible mixture formed in the upper part of the combustion chamber in the immediate area of the spark plug. In this way, the innovation creates the conditions for a stratified charge. Spray-guided combustion, which is the most efficient form of stratified charge, is only possible with the performance features of Piezo technology because a precise, constant and stable injection must be directed to the immediate spark plug area. The nozzle needle completes its full stroke in just 0.2 milliseconds, while the maximum deviation between individual injected quantities of fuel is 2 percent -- even with the typically short injection pulses under driving conditions. For cleaner combustion, extremely fine atomization of the fuel must be maintained. At an injection pressure of approximately 200 bar, the average diameter of the fuel droplets is only 15 thousandths of a millimeter. Together with injector nozzles that open into the engine cylinder, an optimally prepared cloud mixture at the edge of the spark plug is yielded under nearly all operating conditions. This innovation is the only solution on the market able to do this. This spray-guided combustion process is a first in a gasoline engine, and as a consequence, the extent of operating conditions that allow stratified charge is considerably expanded. For example, high displacement engines are able to achieve greater fuel economy at partial loads, while ensuring optimum cylinder charging at full load. Additionally, OEMs may be interested in using the injector to more tightly control combustion processes, including multiple pulses to control the start of combustion. This technique is an enabler to someday allow them to realize Homogeneous Charge Compression Ignition (HCCI). Continental today received the first Environmental PACE (Premier Automotive Suppliers' Contribution to Excellence) Award from Automotive News for its trend-setting gasoline Piezo direct injection technology which improves engine performance, reduces emissions and fuel consumption by 20 percent. This is the third award the Piezo technology has received. The system was also recognized during Ward's 10 Best Engine's of 2007 for the BMW 335i Twin Turbo-3-liter engine contribution and the Automotive News 2008 PACE Award. According to Automotive News, this year's honorees were chosen from the 2008 Automotive News PACE Award winners and were honored again for further innovations contributing to the environmental sustainability and/or solving environmental problems. With targeted annual sales volume of 25 billion Euros for 2008, the Continental Corporation is one of the top automotive suppliers worldwide. As a supplier of brake systems, systems and components for the powertrain and chassis, instrumentation, infotainment solutions, vehicle electronics, tires and technical elastomers, the corporation contributes towards enhanced driving safety and protection of the global climate. Continental is also a competent partner in networked automobile communication. Today, the corporation employs approximately 146,500 people at nearly 200 locations in 36 countries. As a worldwide leading technology and systems partner to the automotive industry, the Chassis & Safety Division of Continental AG integrates extensive know-how and leading-edge quality in the fields of active and passive driving safety, safety and chassis sensors, and chassis components. The Division achieves sales of more than euro 5 billion (based on 2006 figures) with a workforce of more than 27,500 (2007). Chassis & Safety develops and produces electronic and hydraulic brake and chassis control systems, sensors, driver assistance systems, airbag systems, occupant classification systems, washer systems, and electronic air suspension systems. --- [**http://usa.vdo.com/press/releases/powertrain/2006/SV\_20060403\_e.htm**](http://usa.vdo.com/press/releases/powertrain/2006/SV_20060403_e.htm) **Siemens VDO Takes The Direct Route To Injection** *Gasoline Direct Injection Strategy Helps Engines Meet Emissions Targets Without Sacrificing Horsepower* Auburn Hills, Mich., April 03, 2006 Siemens VDO is helping customers take a more direct route in their efforts to meet impending fuel economy regulations by offering gasoline direct injection technology that improves vehicle fuel economy. Direct injection fuel delivery injects gasoline directly into the engine's combustion chamber, enabling the vehicle to start with less fuel while simultaneously improving vehicle drivability and emissions. "Gasoline Direct Injection (GDI) offers the customer a more efficient, cleaner combustion solution by directly injecting the fuel into the combustion chamber near peak pressure to better utilize the gasoline," said Siemens VDO North American Director of Powertrain Gasoline Systems Mike Crane. "Direct injection provides a precisely metered charge to the cylinder that allows beneficial engine design and operating changes - like a higher compression ratio - to be employed on the engine. GDI fundamentally promotes more stable combustion giving the customer better performance and lower hydrocarbon and carbon dioxide emissions with no sacrifice in engine performance. The technology also offers multi-fuel capabilities for emerging E85 applications." Siemens VDO currently is pursuing a dual strategy of solenoid-actuated and piezo-actuated direct injection to address the needs of diverse customer market segments and models. The core components of both these gasoline direct injection systems are the injectors, the EMS 2 engine management system with corresponding software and a high-pressure fuel pump. "Piezo Direct Injection (PDI) offers the customer the greatest possible fuel savings throughout an extended engine operating range by facilitating stable lean combustion in stratified operation," said Crane. "Compared with a conventional port injection, PDI helps reduce fuel consumption by 20 percent, depending on the total level of system integration, including engine downsizing." The Solenoid Direct Injection (SDI) system is a cost effective solution offering significant opportunities to save fuel, reduce emissions and boost torque at lower engine speeds compared to port injection systems. The Deka DI XL2 injector delivers the versatility required for variable injection through enhanced linearity, very fast opening and closing times and varying nozzle designs for swirl or multi-stream spray geometry for optimal adaptation to specific engine requirements. The company also has developed a new high-pressure pump with greater flow control accuracy that requires less power from the engine to operate compared to competitive pumps. The pump generates fuel pressures of up to 20 MPa (200 bar) and works on the transfer principle. The moving parts are contained in an oil chamber separated from the fuel system by a stainless-steel diaphragm to minimize the drive torque, while simultaneously preventing oil contamination of the fuel. "Whether it is a solenoid or piezo system, the Siemens VDO Direct Injection solution is the more direct route to meeting Corporate Average Fuel Economy (CAFE) and emissions targets for the internal combustion engine, while maintaining and in some cases improving performance and drivability," said Crane... --- [**http://usa.vdo.com/products\_solutions/cars/powertrain/gasoline-systems/gasoline-direct-injection/piezo-direct-injection/**](http://usa.vdo.com/products_solutions/cars/powertrain/gasoline-systems/gasoline-direct-injection/piezo-direct-injection/) **Piezo Direct Injection** **Taking fuel economy to new levels** Piezo technology in particular highlights our major contribution to the development of injection systems. We were the first company to put this technology into series production for diesel engines, and are now again up with the frontrunners using piezo injectors in gasoline engines. By using Piezo direct injection, we facilitate stable lean combustion in stratified operation, thereby achieving the greatest possible fuel savings throughout an extended engine operating range. Compared with a conventional gasoline engine with port injection, this technology can reduce fuel consumption by up to 20%, depending on the type of vehicle and driving cycle. --- **DE10244614** **High pressure injection valve for direct fuel injection with fluid cooling and filling process, has electrically insulating heat conductive fluid around the valve needle piezo actuator** Inventor: BACHMAIER GEORG [DE] ; GOTTLIEB BERNHARD Applicant: SIEMENS AG 2004-04-15 **Abstract** --- An injection valve (1) comprises a long hollow cylindrical housing (4) containing a multi-player piezoelectric actuator (2) operating a jet needle (5) for fluid dosing. A hollow space (3) around the actuator is filled with an inert, electrically insulating thermally conductive fluid in contact with the housing. An Independent claim is also included for a filling process for the above. ![](fig1.jpg) --- **US2006231068** **Method and device for controlling the transition between normal operation and overrun fuel cut-off operation of an otto engine operated with direct fuel injection** Inventor: WEISS FRANK [DE] ; ZHANG HONG [DE] Applicant: SIEMENS AKTIENGESELLSCHAFT 2006-10-19 Also published as: US7383813 (B2) DE10334401 (B3) WO2005012712 (A1) EP1649153 (A1) **Abstract** -- The problem during overrun fuel cut-off operations, i.e. cut-off of fuel injection during trailing throttle conditions of the vehicle, is that the transition entails an undue torque jump, resulting in the smooth operation of the engine and the driving comfort of the passengers of the vehicle being affected. The aim of the invention is to reduce the torque jump. Said aim is achieved by injecting fuel into a cylinder of the Otto engine in a multiple injection process, at least a partial quantity of the fuel that is to be injected being injected during the compression phase, whereby the quantity of air that is taken in advantageously decreases because no internal cooling takes place while the efficiency is advantageously reduced due to the lesser degree of swirling, resulting in lower torque.; Overall, torque (DM) is reduced to a significantly greater extent than by merely adjusting the spark angle (ZW) while smooth operation of the Otto engine is not affected. --- **US2007055436** **Method and device for controlling the transition in a direct injection internal combustion engine** Inventor: WEISS FRANK [DE] ; ZHANG HONG [DE] Applicant: SIEMENS AKTIENGESELLSCHAFT 2007-03-08 Also published as: US7328683 (B2) WO2005024213 (A1) KR20060081411 (A) JP2007533887 (T) EP1660766 **Abstract** --- During the changeover from a first operating mode of a spark-ignition engine with direct fuel injection to a second operating mode, in particular between a homogeneous stoichiometric and homogeneous lean, stratified or HCCI operation with changeovers of the valve stroke or the valve phase, there is the risk of an undesired torque jump, which can lead to a perceptible jolting of the vehicle or to a disturbance in the running of the spark-ignition engine. The invention thus proposes, in particular in the case of an inadmissibly large torque jump, the initiation of a multiple injection of fuel in addition to the conventional compensation by the displacement of the ignition angle. A partial quantity of said fuel is injected during the compression phase to reduce the degree of efficiency, thus reducing the torque produced. --- **US2006278196** **Method for controlling an internal combustion engine operating with direct fuel injection** Inventor: BEER JOHANNES [DE] ; ZHANG HONG [DE] Applicant: SIEMENS AKTIENGESELLSCHAFT Also published as: US7210449 (B2) DE10256474 (B3) EP1567760 (A1) WO2004051067 2006-12-14 **Abstract** --- Disclosed is a method, according to which the air fed to the combustion chambers of an internal combustion engine is pre-compressed by means of a boosting device, particularly an exhaust gas turbocharger. The valve overlap of the gas exchange valves of the internal combustion engine is adjusted by variably displacing the camshaft. The quantity of fuel to be injected, which is required for homogeneously operating the internal combustion engine, is determined and injected directly into the combustion chambers of the internal combustion engine, the total quantity of fuel to be injected being divided into two partial quantities. A first partial quantity is injected into the intake stroke while a second partial quantity is injected into the compression stroke. The ratio at which the two partial quantities are divided is defined according to the load range of the internal combustion engine. --- **US2006112680** **Method for heating an exhaust gas catalyst for an internal combustion engine operating with direct fuel injection** Inventor: BEER JOHANNES [DE] ; ZHANG HONG [DE] Applicant: SIEMENS AKTIENGESELLSCHAFT 2006-06-01 Also published as: US7155899 (B2) DE10259052 (B3) EP1576268 (A1) WO2004055347 **Abstract** -- The invention relates to the heating of an exhaust gas catalyst arranged on an internal combustion engine with direct fuel injection, variable valve drive and a blower device, whereby, after recognition of a cold start for the internal combustion engine, by means of a device, the valve lift (VH) and the valve overlap (VO) for the gas exchange valves and the position of a throttle valve, arranged in the inlet tract of the internal combustion engine are adjusted to give a positive pressure drop between the inlet side and the exhaust side of the internal combustion engine such that at least a part of the air pumped by the blower device is pumped directly from the inlet to the outlet side of the internal combustion engine into the exhaust line as flushing air. Optimal reaction conditions are thus obtained in the exhaust gas catalyst. --- **WO2005052344** **METHOD AND DEVICE FOR OPTIMISING THE OPERATION OF AN INTERNAL COMBUSTION ENGINE EMBODIED WITH A DIRECT FUEL INJECTION SYSTEM** Inventor: PRZYMUSINSKI ACHIM [DE] ; JUNG UWE Applicant: SIEMENS AG [DE] ; PRZYMUSINSKI ACHIM 2005-06-09 **Abstract** --- With direct injection of fuel into an internal combustion engine, the problem arises that the amount of fuel to be injected must be controlled with regard to a minimum consumption, minimal pollutant or noise emissions with the greatest possible driving comfort. Conventionally, a compromise is used for the optimisation of the injection with regard to all the above criteria, with the use of a only a few parameters to describe the actual driving situation, above all engine speed and load. The full potential of modern internal combustion engines with multiple injections is, as a rule, not fully realized as a result of said compromise and taking into account of little environmental data.; According to the invention, said problem may be resolved, by means of establishing a classifier (1), which continuously selects one of several different optimisation strategies and then correspondingly controls the direct injection system or other related control systems. The overall performance of the engine management can thus be advantageously improved. --- **US2005085990** **Method for the drift compensation of an injector for the direct fuel injection in a cylinder of an internal combustion engine as well as a device** Inventor: BOHNIG RALF [DE] ; CLOAREC GUY-MICHEL Applicant: SIEMENS AG 2005-04-21 **Abstract** --- In the case of direct injection internal combustion engines, the problem occurs that especially the injection of a minimum amount of fuel depends in particular on different operating parameters such as the speed, the start of the injection or the rail pressure. Therefore, a method or a device is suggested in which a control unit ( 10 ) subdivides the complete range of values of at least one operating parameter into discrete sections. Subsequently, for each section, at least one operating point is specified for which a corresponding correction value depending on the operating parameter is determined and obtained. The correction value is then stored together with its corresponding operating point. This has the advantage that the correction value can be determined more accurately because interpolation can for example also be performed between two operating points. --- **FR2855848** **Otto engine operating speeds passage controlling method, involves adapting switching thresholds according to quality of combustion of air/fuel mixture and using value of thresholds to control switching process of speeds** Inventor: WEISS FRANCK ; ZHANG HONG Applicant: SIEMENS AG [DE] 2004-12-10 **Abstract** -- The method involves obtaining quality of combustion of air/fuel mixture in cylinders of an Otto engine from gradient velocity of rotation. Switching thresholds are adapted according to the quality of the combustion. A predetermined value of the switching thresholds is used to control subsequent switching process of two operating speeds e.g. operation with homogenous mixture and stratified mixture. - An INDEPENDENT CLAIM is also included for a device of controlling passage between two operating speeds of an Otto engine with direct fuel injection. --- **WO2004065775** **METHOD FOR CALCULATING PRESSURE FLUCTUATIONS IN A FUEL SUPPLY SYSTEM OF AN INTERNAL COMBUSTION ENGINE OPERATING WITH DIRECT INJECTION OF FUEL AND FOR CONTROLLING THE INJECTION VALVES THEREOF** Inventor: BRUNELLI MARCO CLAUDIO PIO Applicant: SIEMENS AG [DE] ; BRUNELLI MARCO CLAUDIO PIO [DE] 2004-08-05 Also published as: DE10302806 (A1) EP1585895 **Abstract** --- The method involves obtaining quality of combustion of air/fuel mixture in cylinders of an Otto engine from gradient velocity of rotation. Switching thresholds are adapted according to the quality of the combustion. A predetermined value of the switching thresholds is used to control subsequent switching process of two operating speeds e.g. operation with homogenous mixture and stratified mixture. - An INDEPENDENT CLAIM is also included for a device of controlling passage between two operating speeds of an Otto engine with direct fuel injection. --- **DE10341789** **Start-up method for an internal combustion engine uses direct fuel injection into a combustion chamber, pressure assessment and coolant temperature** Inventor: ESER GERHARD [DE] ; ZHANG HONG Applicant: SIEMENS AG [DE] 2005-04-28 **Abstract** --- An assessed value (PAKT) is determined for fuel pressure during a start-up process. A low-pressure start is controlled if a preset number of assessed values fall short of a preset threshold value. Otherwise, a high-pressure start (HP) is controlled. Fuel pressure assessed values are detected by relying on a variable for coolant temperature (TCO). - An INDEPENDENT CLAIM is also included for a device for starting up an internal combustion engine. --- **DE10341089** **Direct fuel injection system for internal combustion engine maximizes amount of air trapped in cylinder by injecting compressed natural gas during compression stroke after inlet valve has closed** Inventor: WEISS FRANK [DE] ; ZHANG HONG Applicant: SIEMENS AG 2005-04-28 Also published as: NL1026955 (A1) NL1026955 **Abstract** --- During the induction stroke the inlet valve (EV) is open during the first part of the stroke (a1) from top dead center (OT) to approximately 90 degrees crank angle (W). It gradually closes during the second part of the stroke (a2), with closure finishing at or near a crank angle of 180 degrees. - The inlet and exhaust valves are closed during the compression stroke (b). A control computer with a program store and a data store regulates injection of fuel gas (E1-4). --- **EP1296053** **Process for direct fuel injection in the form of two injections with different injection angles and injection control device** Inventor: ZHANG HONG DR Applicant: SIEMENS AG [DE] 2003-03-26 **Abstract** --- Fuel injector module, for an IC motor, has a compensation unit linked to the actuator, within a sleeve with heat conductivity in contact with it and the housing to compensate for the housing change through thermal expansion Inventor: DICK JUERGEN [DE] ; LIXL HEINZ Applicant: SIEMENS AG [DE] --- **DE10152903** **Direct fuel injection control system for internal combustion engine has timing controlled to promote stratified charge at low speed and homogenous mixture at high speed** Inventor: SCHOPP GERHARD [DE] ; WIESE THILO Applicant: SIEMENS AG [DE] **Abstract** --- The control system performs a first control step (S10) to determine the running speed (U) of the engine. The second step (S11) compares the engine speed with a threshold value (SW). If U greater than SW (Ja), then a third step (S12) is performed, to calculate the injection path for the next cylinder to receive a fuel injection. If U less than SW (Nein), then a fourth step (S13) is performed, to calculate the injection paths for all cylinders. The third or fourth step runs a fifth step (S14) which triggers the next fuel injection. 2003-05-15 --- **EP1124057** **Fuel injector with a cone shaped bent spray** Inventor: NITKIEWICZ JAMES ANTHONY [US] ; FOCHTMAN JAMES PAUL Applicant: SIEMENS AUTOMOTIVE CORP LP [US] 2001-08-16 Also published as: EP1124057 (A3) US6308901 (B1) JP2001221134 **Abstract** --- An injector for high pressure direct fuel injection in an internal combustion engine is disclosed. The injector has a downstream end and a longitudinal axis extending therethrough. The injector has an outlet orifice located at the downstream end. The outlet orifice has an outlet axis oblique to the longitudinal axis. The outlet orifice discharges a circular cone-shaped spray having a spray axis co-linear with the outlet axis. A method of forming a bent circular cone-shaped spray pattern is also disclosed. --- **DE19943142** **Direct fuel injection dosing/proportioning device especially for petrol and diesel-powered combustion** **engines** Inventor: GOTTLIEB BERNHARD [DE] ; KAPPEL ANDREAS Applicant: SIEMENS AG [DE] 2001-04-12 **Abstract** --- A fuel dosing/proportioning device has an axially- displaceable needle (20,30) carried in a housing (17) and forming together with one wall of the housing (17) an externally opening valve. An actuator cavity is provided for receiving an electromechanical actuator, which is supported on the housing (17) and by means of an expansion of the actuator the valve needle (20,30) is lifted in a controlled manner so as to open and close the valve. With positioning of the valve needle (20,30) on a valve seat (2) of the valve, at least one pressurisable boring (14) opens out into sealing face formed by the valve needle (20,30) and the valve seat(2). --- **WO0009878** **METHOD FOR CONTROLLING AN INTERNAL COMBUSTION ENGINE WITH DIRECT FUEL INJECTION** Inventor: FROEHLICH JOHANN [DE] ; ZHANG HONG Applicant: SIEMENS AG [DE] ; FROEHLICH JOHANN 2000-02-24 **Abstract** --- An internal combustion engine with direct fuel injection is operated with a stratified air-fuel mixture when a condition depending upon the air-fuel mixture ratio is met. Otherwise, the internal combustion engine is operated with a homogeneous air-fuel mixture. --- **FR2778699** **Valve control device e.g. for common-rail diesel direct fuel injection system for vehicle combustion engine** Inventor: KAPPEL ANDREAS ; MOCK RANDOLF Applicant: SIEMENS AG [DE] 1999-11-19 Also published as: FR2778699 (B1) ITMI991025 (A1) DE19821768 (A1) US6062533 **Abstract** --- A valve control device includes a housing (1) provided with a hydraulic chamber (2) and two borings (3,4) both discharging into the hydraulic chamber (2). Also included is a primary drive (5) arranged at least partially in the first boring (3) and provided with a piston boring (16) which discharges into the hydraulic chamber (2). A secondary-side lifting element (7) is arranged in the second boring (4) so that the primary drive (5) and the lifting element (7) form a piston chamber (9) within the piston boring (16). The surface of the lifting element (7) pressure-actively exposed to the fluid (6) in the hydraulic chamber (2) in the direction of movement, is smaller than that of the primary drive (5).; The pressure active surface of the lifting element acting in the direction of the piston boring (16) in the hydraulic chamber (2) is greater than the surface acting in the direction of the second boring (4). A hydraulic drag is present between the primary drive (5) and the lifting element (7), the latter serving to close the connecting line (27) against the outflow. ---