Abstract: A deformable fastener assembly for use with a gas turbine engine. The deformable fastener may be used to fasten a component of the gas turbine that is subjected to high temperatures and thermal deformation, such as an impingement sleeve assembly, to a rigid portion, such as the inner turbine shell of the gas turbine engine. The deformable fastener assemblies may permit components to be fastened to a rigid portion of the gas turbine with a consistent load input to permit frictional transient sliding of the component relative to the rigid portion of the gas turbine engine.

Abstract: An exit piece (66) with an inlet throat (67) that conducts a combustion gas flow (36A) in a path (82) from a combustor (63) to an annular chamber (68) that feeds the first blade section (37) of a gas turbine (26). The exit piece further includes an outlet portion (69) that forms a circumferential segment of the annular chamber. The outlet portion interconnects with adjacent outlet portions by hinges (78A, 78B, 80A, 80B). Each hinge may have a hinge axis (82A, 82B) parallel to a centerline (21) of the turbine. Respective gas flows (36A) are configured by an assembly (60) of the exit pieces to converge on the feed chamber (68) into a uniform helical flow that drives the first blade section with minimal circumferential variations in force.

Abstract: A gas turbine system includes a fuel nozzle. The fuel nozzle includes a first fluid conduit defining a first fuel passage, a second fluid conduit defining a second fuel passage, and a third fluid conduit defining an oxidant passage. A first plurality of orifices is disposed along the first fluid conduit and is configured to fluidly couple the first fuel passage to the oxidant passage. A second plurality of orifices is disposed on the third fluid conduit and is configured to fluidly couple the second fuel passage to the oxidant passage. A first diameter of the first plurality of orifices is less than a second diameter of the second plurality of orifices.

Abstract: An air bleed system for a gas turbine engine includes an annular bleed case with a manifold therein. The annular bleed case has a forward section and an aft section and ligaments connecting the two sections. The forward section, the aft section and the ligaments define bleed ports. The manifold is disposed radially outward of the ligaments and communicates with the series of bleed ports.

Abstract: A throttle valve for preventing a sudden unintended acceleration, the throttle valve regulating an amount of air supplied to an engine mounted on a vehicle and including a valve main body, a flow path formed in the valve main body and having an inlet through which the air flows in and an outlet connected to the engine, and a flow rate regulating unit regulating an amount of the air in the flow path by opening or closing the flow path, in which, when a rapid pressure drop occurs at the outlet side connected to the engine, the flow rate regulating unit is pressed by a force generated due to a difference in pressure between the inlet and the outlet so as to close the flow path without use of an additional drive source.

Abstract: A premixed charge of air and a low reactivity fuel is created in a combustion chamber space by the time at which a piston comes substantially to top dead center at which time a high reactivity fuel is directly injected into a central zone of the combustion chamber space which is bounded partially by a central bowl cavity in the piston head which is itself surrounded by an upright intermediate wall. The high reactivity fuel combusts by conventional diesel combustion and creates a flame front which propagates into an outer zone of the combustion chamber space which is bounded partially by the upright intermediate wall and an outer bowl cavity in the piston head to initiate combustion of the premixed air-fuel charge in the outer zone of the combustion chamber space.

Abstract: Methods and systems are provided for improving engine knock control by accounting for a drop in charge cooling efficiency of a knock control fluid at higher temperatures. In response to the prediction of an elevated temperature of a knock control fluid at a time of release from a direct injector, a pulse width of the injection is adjusted. Any knock relief deficits are compensated for using alternate engine adjustments, such as boost or spark timing adjustments.

Abstract: There is provided a system and method for controlling an engine. A request signal indicative of a demand for the engine to output a required power level is first receive. A position control signal is then generated in response to the request signal. The position request signal is indicative of a first request for adjusting a present position of a variable geometry mechanism of the engine towards a commanded position to achieve the required power level. An acceleration rate control signal is further generated on the basis of the position control signal. The acceleration rate control signal is indicative of a second request for adjusting an acceleration rate of the engine in accordance with the commanded position of the variable geometry mechanism. The position control signal and the acceleration rate control signal are then output to the engine.

Abstract: Methods and systems for fuel system leak detection in a hybrid electric vehicle using a fuel reservoir are disclosed. In one example approach, a method comprises, during an engine off condition, delivering fuel from a fuel tank into a reservoir while the fuel tank is vented to atmosphere, discontinuing delivering fuel into the reservoir, sealing the fuel tank from atmosphere, and following the sealing, indicating a leak based on a pressure increase in the fuel tank from a pressure when sealed from venting.

Abstract: An internal combustion engine in a motor vehicle is automatically shut off and started by way of a start-stop device, wherein an automatic shut-off process is initiated during a coasting operation phase of the internal combustion engine, and an automatic start process is initiated when at least one activation command occurs. For shutting off the internal combustion engine in the coasting operation phase, a gas exchange in cylinders of the internal combustion engine is at least almost completely suppressed and, at the same time, a torque converter lock-up clutch disposed between the internal combustion engine and the transmission for power transmission purposes is actuated such that the torque converter lock-up clutch remains or is at least almost completely engaged.

Abstract: An engine-powered work tool includes an engine having a crank shaft, an output controller and a wind governor. The output controller includes an output control shaft angularly rotatable about its axis for controlling a rotation speed of the crank shaft. The wind governor can control the angular rotation of the output control shaft and includes: a governor plate for receiving cooling air generated at a cooling fan connected to the crank shaft; an arm fixed to the output control shaft; and a governor spring connected to the arm for biasing the output control shaft to increase the rotation speed of the crank shaft. The governor plate functions to bias the output control shaft to decrease the rotation speed of the crank shaft upon receipt of the cooling air. The governor spring has an end changeable in position relative to the output controller among a plurality of prescribed positions.

Abstract: Various methods for estimating electric actuator temperature during certain operational windows are provided. In one example, a method comprises adjusting an electric motor to position a wastegate at a desired wastegate position, while during selected conditions, deviating from the desired position by at least one full half-turn of the motor and indicating motor temperature based on winding resistance averaged over the full half-turn.

Abstract: An ignition control device for an internal combustion engine, which controls the number of times of ignition operation such that it becomes neither too large nor too small, according to a flowing state of a mixture in a cylinder. In the ignition control device, a target ignition timing is used as an in-cylinder flow parameter indicative of the strength of a tumble flow generated in a cylinder. When the target ignition timing is more advanced than a predetermined reference position, it is determined that the tumble flow is strong, and multiple ignition control is executed by setting the number of times of ignition to a plurality of times, whereas when the former is more retarded than the latter, it is determined that the tumble flow is not strong, and normal ignition control is executed by setting the number of times of ignition to only once.

Abstract: A method and a system for providing vacuum via an engine are described. In one example, introduction of a gaseous fuel is ceased in response to a request for the engine to provide vacuum to a vehicle vacuum system.

Abstract: Methods and systems are provided for improving canister purging during the limited engine operation time in a hybrid electric vehicle. Prior to a transition into an engine-on mode, a canister heater is operated to heat the canister to an optimum temperature based on vehicle operating conditions. Upon transition into the engine-on mode, fuel vapors released from the heated canister are purged to an engine intake.

Abstract: There is provided an internal combustion engine control apparatus that can more accurately calculate a volume efficiency correction coefficient and can more accurately estimate the amount of air that flows into a cylinder and the external exhaust gas recirculation amount. In an internal combustion engine provided with an exhaust gas recirculation apparatus including an exhaust gas recirculation valve and an exhaust gas recirculation path, based on a cylinder flow rate, an exhaust gas recirculation amount, an inner-intake-pipe density, and an inner-intake-pipe density changing amount, a volume efficiency correction coefficient, as a volume efficiency corresponding value, is calculated; then, by use of the calculated volume efficiency correction coefficient, a cylinder intake air amount and a recirculation amount of exhaust gas that is taken into the cylinder are calculated.

Abstract: A method for controlling differences in cylinder mixtures for a two cylinder bank engine having a turbocharger is presented. In one example, the description includes a method for adjusting valve timing to reduce cylinder mixture variation.

Abstract: A method for operating an internal combustion engine comprising an emission control system that includes at least one catalytic and/or filter-effective emission control component. In conjunction with a cold start and/or a warm-up of the internal combustion engine, the internal combustion engine is operated using a cold start engine operation process having predefined values for predefined operating parameters of the internal combustion engine. An amount of hydrocarbons (HC) stored in one or more of the at least one emission control component is estimated, and the cold start engine operation process is activated when the estimation indicates that the amount of stored HC exceeds a predefined maximum amount of stored HC.

Abstract: A system according to the principles of the present disclosure includes a stop-start module and a throttle control module. The stop-start module stops an engine when a driver depresses a brake pedal while an ignition system is on and the engine is idling. The throttle control module selectively opens a throttle valve when fuel injection in the engine is stopped while the ignition system is on based on engine speed and a manifold pressure within an intake manifold. The stop-start module starts the engine when the driver releases the brake pedal.

Abstract: An engine control apparatus for a hybrid vehicle is provided with a conversion angle detecting device, an angle determining device, an engine load calculating device and an engine control device. The conversion angle detecting device detects a rotational phase of a cam with respect to a crankshaft as a detected conversion angle of a variable valve operating mechanism of an engine. The angle determining device determines if the detected conversion angle is different from a starting conversion angle when the engine is started. The engine load calculating device calculates a requested load to be imposed on the engine based on the detected conversion angle if the detected conversion angle is different from to the starting conversion angle at a time the engine is started. The engine control device controls the engine in accordance with the requested engine load that was calculated.

Abstract: In an inductive element which is intermittently excited by a boosting opening and closing element and charges a high-voltage capacitor to a high voltage, an inductive element current proportional to a voltage across both ends of a current detection resistor and a boosted detection voltage which is a divided voltage of the high-voltage capacitor are input to a boosting control circuit portion via a high-speed A/D converter provided in an arithmetic and control circuit unit. The boosting control circuit portion adjusts the inductive element current so as to be suitable for the time from the present rapid excitation to the next rapid excitation, and controls opening and closing of the boosting opening and closing element so as to obtain a targeted boosted high voltage which is variably set by a microprocessor of an arithmetic and control circuit unit.

Abstract: A method and system for improving operation of an engine that is supplied a fuel having a low super critical temperature is presented. In one example, the method supplies fuel to cool a direct injection fuel pump and participate in combustion in an engine cylinder after the fuel is vaporized. The method also provides for injecting a liquid fuel to the engine cylinder via the direct injection fuel pump.

Abstract: In a method for operating a valve, e.g., a fuel injector of an internal combustion engine in a motor vehicle which is activated with the aid of an actuator, the actuator is activated using a control variable which has a predetermined control period. The control period is formed as a function of a setpoint value for a closing delay time of the valve which characterizes a time difference between an end of the control period and a closing point in time of the valve.

Abstract: A method controlling operation of an engine utilizing a number of preset operating parameters is provided. An operating mode of the engine is determined. An operating state of the engine is determined. A first plurality of engine parameter settings are retrieved from a memory in response to the determined operating mode and the determined operating state of the engine. The first plurality of engine parameter settings are applied to at least one control algorithm of the engine. A rate of soot accumulation from the engine is monitored. The rate of soot accumulation is compared to a predetermined soot accumulation rate threshold. A second plurality of engine parameter settings are retrieved from a memory in response to the monitored rate of soot accumulation exceeding the predetermined soot accumulation rate threshold.

Abstract: A method for the production of a piston for an internal combustion engine, having a piston head, a piston skirt, and a circumferential recess configured between the piston head and the piston skirt. The piston has a piston base body and a piston ring element. The piston base body has at least a crown region of a combustion bowl as well as the piston skirt. The piston ring element has at least a piston crown, a wall region of the combustion bowl, a circumferential top land, and a circumferential ring belt with ring grooves. The piston ring element has a circumferential cooling channel between the wall region of the combustion bowl and the ring belt, closed with a closure element. The piston base body and the piston ring element are connected by a circumferential joining seam in the region of the combustion bowl.

Abstract: A green treatment process for cleaning exhaust gas generated in the air oxidation of benzene homologs is disclosed. It takes the hot pressurized exhaust gas generated in the benzene homolog air oxidation process as driving power and heating source: firstly, introducing the said exhaust gas into a turbine refrigerator so that it can drive the refrigerator to generate the cooling capacity that will be utilized for condensing the gas phase in the upper part of the flash evaporator and for trapping organics entrained in the exhaust gas; then, leading the exhaust gas with lowered temperature and pressure into corresponding heat exchangers to provide a part of heating source for the flash evaporator and to preheat the reaction raw materials. Furthermore, introducing the condensed exhaust gas into a water absorption scrubber for further removal of trace organics entrained therein.

Abstract: A hydraulic circuit for a jet engine thrust reverser is disclosed. The hydraulic circuit may comprise a primary hydraulic actuator cylinder assembly and a secondary hydraulic actuator cylinder assembly. The primary hydraulic actuator cylinder assembly may be hydraulically coupled to the secondary hydraulic actuator cylinder assembly, in a master-slave relationship, and the secondary hydraulic actuator cylinder assembly may drive a thrust reverser blocker door. The primary hydraulic actuator cylinder assembly may comprise a rod, and the rod may comprise a channel through which hydraulic fluid is capable of flowing. The hydraulic circuit may further comprise a group of secondary hydraulic actuator cylinder assemblies, wherein the group of secondary hydraulic actuator cylinder assemblies may be coupled to the primary hydraulic actuator cylinder assembly.

Abstract: A gaseous fuel mixer for an internal combustion engine includes a check valve. The check valve includes a check valve member that induces mixing of a gaseous fuel flow and an intake air flow as the gaseous fuel flow and intake air flow move or pass from an upstream side of the check valve to a downstream side of the check valve.

Abstract: A supercharging system for an engine includes: a cylinder block forming a combustion chamber; an intake manifold connected to the cylinder block to supply ambient air thereto; an exhaust manifold collecting exhaust gas discharged from the combustion chamber and guiding the same to the environment; a third supercharge path connecting an inlet of the intake manifold to the exhaust manifold; and an electric supercharger supplying compressed air to the exhaust manifold through the third supercharge path. Responsiveness of an engine is enhanced and stabilization of the engine is promoted.

Abstract: A method for operating an engine system is described herein. The method includes moving a plurality of vanes in a variable geometry turbocharger toward a closed position in response to tip-out and after moving the plurality of vanes toward the closed position, moving an EGR valve from a fully closed position toward an open position in response to tip-in, the EGR valve in fluidic communication with an exhaust sub-system upstream of the turbine. The method further includes, after moving the EGR valve toward an open position, moving the plurality of vanes based on one or more of a driver-requested torque, engine speed, and engine temperature.

Abstract: An intake manifold having an EGR-air flow distributor for distributing the desired air flow and EGR-air mixture through the intake manifold to each cylinder is disclosed. The EGR-air flow distributor includes a set of guide vanes defining plural flow channels in a plenum region of the inlet manifold. The EGR-air flow distributor also includes an EGR tube partially extending into the inlet manifold and having a slot formed therein for introducing EGR into the plenum region at a single location between the engine throttle and the guide vanes.

Abstract: A motor vehicle exhaust gas recirculation valve arrangement for an exhaust gas recirculation system of an internal combustion engine includes an electric drive motor, an intermediate shaft, an eccentric shaft, and a valve drive. The electric drive motor comprises a motor shaft and a motor pinion. The intermediate shaft comprises an intermediate shaft pinion and an output gear. The output gear is configured to mesh with the motor pinion. The eccentric shaft comprises an eccentric and a drive gear. The drive gear is configured to mesh with the intermediate shaft pinion. A valve drive comprises a valve plate, a valve rod, and a link. The link is configured to have the eccentric engage therein. The intermediate shaft is arranged laterally beside the eccentric shaft so that the eccentric and the link lie beside the drive motor.

Abstract: Methods and systems are provided for detecting a fuel system leak. While a system vacuum pump is operated to supply vacuum to a vacuum consumption device, air exhausted from the vacuum pump is routed to a fuel system to apply positive pressure thereon. A fuel system leak is identified based on a rate of decay of the pressure applied from the vacuum pump.

Abstract: Methods and systems are provided for estimating a fuel canister purge flow based on outputs of an intake manifold oxygen sensor. For example, during boosted engine operation when exhaust gas recirculation (EGR) is flowing below a threshold and purge is enabled, purge flow may be estimated based on changes in the sensor output while modulating a canister purge valve between an open and closed position. Then, during subsequent operation wherein EGR and purge flow are enabled, the output of the sensor may be adjusted based on the estimated purge flow.

Abstract: To reduce size and weight of canister while improving adsorbing/desorbing performance by optimizing adsorbent that fills chamber located at air release side. Adsorbent filling chambers 8, 9 located at air port 5 side, of a plurality of chambers 5˜8 that are arranged in series along an air flow direction in case 2, is formed by macroscopic pore whose diameter is 50 nm or greater. The adsorbent has hollow cylindrical shape whose inside thickness is 0.6 to 1.5 mm and whose outside diameter is 4 to 6 mm or hollow spherical shape whose inside thickness is 0.6 to 1.5 mm and whose diameter is 4 to 6 mm. A ratio of volume of the macroscopic pore whose diameter is less than 500 nm to total volume of the macroscopic pore whose diameter is equal to or greater than 50 nm is within a range of 30 to 70%.

Abstract: An air filter for a combustion engine for off-load motorcycles is made from a porous foam material. The air filter has contiguous side surface forming a cavity with at least two openings where the side surface contains at least one filter layer, a bottom surface closing at least one of the two openings where the bottom surface contains at least one filter layer, where the side surface has more air resistant than the bottom surface. The side surface has more air resistant than said bottom surface by arranging any combination of thickness of the surfaces, number of layers, and porosity ratio of the layers.

Abstract: A hand-held working implement comprises an internal combustion engine, an air filter, and an intermediate flange, wherein the intermediate flange is arranged between the air filter and the internal combustion engine, wherein the bottom of the intermediate flange is arranged opposite the air filter bottom, wherein the air filter bottom and the intermediate flange bound an interior space, wherein the interior space comprises a portion of the duct, wherein a portion of the duct in the interior space is bounded by at least one boundary wall which protrudes into the interior space transversely with respect to the air filter bottom, wherein the boundary wall is formed integrally on the intermediate flange and/or on the air filter bottom, and wherein the boundary wall bridges the spacing between the air filter bottom and the bottom of the intermediate flange.

Abstract: A system and method for engaging a slide-in mountable fuel pump assembly with a fan cover of an internal combustion engine is disclosed. The fuel pump assembly includes a fuel pump configured to pump fuel from a fuel source to the engine and a mounting bracket affixed to or formed integrally with the fuel pump and configured to slidingly engage a fan cover of the engine so as to enable selective mounting and removal of the fuel pump assembly to and from the fan cover. The mounting bracket further includes a main plate affixed to or formed integrally with the fuel pump and a track formed on each of opposing sides of the main plate, with the track configured to slidingly engage a mating feature formed on the fan cover of the engine so as to selectively mount the fuel pump assembly to the fan cover.

Abstract: A fuel injection valve includes a cylinder internal pressure sensor disposed in the vicinity of a distal end thereof. The cylinder internal pressure sensor detects a cylinder internal pressure in a cylinder and outputs a first sensor signal Ss1 responsive to the detected cylinder internal pressure. Further, a signal processor, which carries out predetermined signal processing with respect to the first sensor signal Ss1 to thereby convert the first sensor signal Ss1 into a second sensor signal Ss2, is disposed between the cylinder internal pressure sensor and a solenoid unit, which is disposed on a proximal end side of the fuel injection valve.

Abstract: The inventive subject matter provides apparatus, systems and methods for treating and delivering a fuel to a combustion chamber of an engine in order to improve efficiency of the engine. In one aspect of the invention, a fuel injector that cooperates with an internal combustion engine to combust a first fuel to produce power is presented. The fuel injector includes a fuel inlet, a pre-conditioning vortex chamber, and an excitation chamber. The fuel injector includes a vortex chamber that conforms a pulsed amount of the first fuel to produce a vortex that includes a coherent dynamic pressure wave. The fuel injector also includes an excitation mechanism that at least partially ignites the fuel.

Abstract: The present invention relates to a fuel injector. The fuel injector is provided with an injection nozzle, an injection valve, and an electromagnetic actuator. The injection valve has a movable needle to adjust the flow of fuel through the injection nozzle. The electromagnetic actuator is adapted to move the needle between a closing position and an opening position of the injection valve and is provided with a movable plunger which is mechanically connected to the needle and has at least one feeding through hole for the passage of fuel towards the injection nozzle. The plunger is provided with a hydraulic type braking device, which is coupled to the feeding hole and hydraulically dissipates kinetic energy to slow down the opening stroke of the needle when the needle moves towards the opening position of the injection valve.

Abstract: A fuel injection valve realizing improved circumferential uniformity of swirling fuel is provided. The fuel injection valve includes swirling chambers each having an inner peripheral wall whose curvature is gradually larger from upstream to downstream, paths for swirling each of which, having a fuel flow-in region formed along a valve axis direction, guides fuel to the associated one of the swirling chambers, and fuel injection orifices open into the associated swirling chambers, respectively. In the fuel injection valve, a curved portion is formed on the bottom, in a sectional view along the valve axis direction, of an inlet portion of each of the paths for swirling so as to change the fuel flow in each of the paths for swirling.

Abstract: An internal combustion engine has an ignition promotion unit that has a function of promoting ignition of fuel sprays formed by the small quantity injections by supplying the fuel sprays with electric energy. The engine is provided with a control device which has a combustion control unit that carries out processing of causing the fuel injection valve to perform the plurality of times of small quantity injections so that fuel sprays formed by the first-time small quantity injection from among the plurality of times of small quantity injections are connected with one another by the fuel sprays formed by the subsequent small quantity injections from among the plurality of times of small quantity injections.

Abstract: One embodiment provides a recoil starter mechanism, including: a starter case having a rotation shaft; a rope reel rotatably mounted on the rotation shaft; a coil spring wound on the rotation shaft, one end thereof being formed into a tip projecting portion; a hold plate holding the coil spring to the rotation shaft; and a ratchet which is formed into a ring-like shape and interposed between the rope reel and the hold plate. The ratchet includes: a fulcrum around which the ratchet is swingable with respect to the rope reel; a guide groove in which the tip projecting portion is engaged; and an engagement pawl which is to be engaged with an engagement portion of a pulley to thereby start an engine. The guide groove and the engagement pawl are disposed at opposite sides so as to interpose the rotation shaft therebetween.

Abstract: Systems and methods for starting an engine of a hybrid vehicle that includes two electric machines capable of starting an engine are presented. In one example, one of the two electric machines is selected to start the engine in response to degradation of one or more vehicle components and an engine start request.

Abstract: A process is provided for preparing a defined starting operation of a motor vehicle selectable by the driver, having a starting element arranged between an engine and a transmission. In the event of a maximal power demand by the driver and in the event of the selection of the defined starting operation by an electronic control unit, the rotational speed or the torque of the engine is set to a specified value, wherein the specified value is automatically determined by the electronic control unit as function of a determined friction parameter, by which at least one relative prediction concerning the transmissible drive torque to be expected for the acceleration operation can be made, such that, by use of the specified during the starting and acceleration operation following the preparation, the maximally possible drive torque is achieved for the best possible acceleration.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, torque demand of a driveline after a shift is forecast to determine if it is desirable to start the engine early so that engine torque is available after the shift. The approach may improve vehicle torque response.

Abstract: A remote start vehicle system for a vehicle is provided. The system includes a remote start requester configured to request that the engine be started. The remote start requester is operable to request that the engine be started when the remote start requester is located outside of the vehicle. A control module is configured to cause the engine to be started upon request from the remote start requester. A sensor assembly is configured to sense a neutral gear state of the transmission, where the neutral gear state indicates whether the transmission is in neutral. The sensor assembly is configured to communicate the neutral gear state to the control module. The control module is configured to prevent the engine from being started if the neutral gear state indicates that the transmission is not in neutral. A method of remotely starting an engine is also provided.

Abstract: A method for detecting the development of detonation phenomena in an internal combustion engine (1) which includes determining the variance (?i) of each combustion taken into account for a given cylinder (2) and in a given engine point as a function of the comparison between the detonation energy (?i) of each combustion taken into account and the self-learnt mean detonation energy (?i_m) for the given cylinder (2) and in the given engine point; calculating the maximum variance (?i_max) for a given cylinder (2) and in a given engine point with a reduction of the spark advance actuated in the given cylinder (2); and determining the development of detonation phenomena for each combustion taken into account as a function of the comparison between the maximum variance (?i_max) and the variance (?i) of each combustion taken into account for a given cylinder (2) and in a given engine point.

Abstract: A method for controlling the surface temperature of a glow plug. A heating current flowing through the glow plug and a voltage applied to the glow plug are measured, a temperature-dependent control variable is calculated from measured values of the heating current and the voltage using a first calculation rule, a target value of the control variable is calculated from a target temperature using a second calculation rule, the control variable is compared with the target value and, to minimize any deviation, the duty cycle of the pulse-width modulation is changed in accordance with this deviation. A value other than electrical resistance dependent on current and voltage is used as the control variable. The calculation rule in accordance with which this variable is calculated from measured values of current and voltage is provided to carry out the method and is established in each case for a series of glow plugs.