DE102016224682A1 - Method for heating a gas valve, in particular a fuel injector - Google Patents

Abstract

For a method for heating a gas valve (31), in particular a fuel injector (31), with a magnet coil (36) by generating eddy currents, wherein the gas valve (31) can be opened by energizing the magnet coil (36), wherein the magnet coil ( 36) by a voltage source (21,22) is acted upon by a current (13), it is proposed that the magnetic coil (36) during at least one heating period (49,50) corresponding to a voltage-time profile (10) with an alternating Voltage (12) is applied, so that in the gas valve (31) eddy currents are generated, wherein the current (13) during the entire heating period (49,50) is smaller than an opening current (lo), which is used to open the gas valve (31 ) necessary is.

Description

State of the art

The invention relates to a method for heating a gas valve, in particular a fuel injector, having the features of the preamble of the independent claim 1.

An internal combustion engine has one or more cylinders with a combustion chamber into which a precisely defined amount of fuel is to be injected at a precisely defined time in the cylinder duty cycle. Fuel injectors are used to meter the amount of fuel. All fuel injectors together with their control form an injection system.

Fuel injectors for gaseous fuels must have a particularly small leakage, so that the predetermined time-volume profile for the injection is maintained exactly. In place of the usual in fuel injectors for liquid fuels metal-metal seals at the metering point therefore often metal-elastomer seals are used. At cold ambient temperatures, these seals tend to stick. If the opening force exerted during activation of the injector is insufficient to overcome the resistance caused by sticking in addition to the restoring force of the valve spring and the back pressure of the gas in the fuel rail, the injector is not functional and the cold start is jeopardized.

From the EP 1 950 409 B1 a method for controlling an injection system is known with which the cold start of a bivalent, that can be operated either with gasoline or gas, internal combustion engine can be facilitated.

In a monovalent, i. only gas-powered, internal combustion engine, there is an even more urgent need to facilitate the cold start, since there is no possibility in a failure of the cold start to move the motor vehicle by its own power.

Disclosure of the invention

According to the invention, a method is proposed for heating a gas valve, in particular a fuel injector, with a magnetic coil by generating eddy currents. The gas valve can be opened by energizing the magnetic coil, wherein the magnetic coil is acted upon by a current from a voltage source. According to the invention, the magnet coil is subjected during at least one heating period corresponding to a voltage-time profile with an alternating voltage, so that eddy currents are generated in the gas valve, wherein the current during the entire heating period is less than an opening current, which is necessary to open the gas valve ,

Advantages of the invention

By the method and apparatus, during the heating period, the application of alternating voltage, i. E. Time-varying voltage, a time-varying magnetic field generated. The time-varying magnetic field generated by the magnetic coil induces eddy currents in electrically conductive parts of the gas valve, for example a fuel injector. The eddy currents can advantageously heat the electrically conductive parts of the gas valve. Thus, can be introduced by the inventive method by the alternating voltage and thereby induced in the electrically conductive parts of the gas valve eddy currents even with comparatively low currents, a very high heat output. The eddy currents can be advantageously induced for example in a gas injector designed as a gas valve, for example in the armature of the fuel injector, so that this is heated and the heat is introduced directly, for example, to the metal-elastomer seal of the fuel injector. By heating in the region of the metal-elastomeric seal by the eddy currents, for example in the armature or in other electrically conductive parts of the fuel injector, the region of the metal-elastomeric seal can be heated to a temperature at which sticking of the elastomer to the metal is excluded. Thus, the fuel injector for injecting fuel can be easily and safely opened by energizing the solenoid, without sticking of the elastomer to the metal occurs. Thus, the cold start of a motor vehicle can be advantageously improved by the inventive method and apparatus according to the invention, for example, for a gas valve designed as a fuel injector. In this case, during the heating period, the current through the coil is advantageously always lower than an opening current which is necessary for opening the gas valve. Thus, for example, a gas valve designed as a fuel injector in the method according to the invention and in the device according to the invention during the entire heating period, while the eddy currents for heating the fuel injector are induced in electrically conductive parts of the injector, advantageously closed so that advantageously no fuel during the entire heating period is injected by the fuel injector.

Furthermore, by induced eddy currents, an advantageously higher heating effect in the example designed as a fuel injector Gas valve can be generated, for example, would be possible by heat generation in current flow through the solenoid due to the ohmic resistance of the solenoid.

Further advantageous embodiments and modifications of the invention are made possible by the features specified in the subclaims.

According to an advantageous embodiment, it is provided that the alternating voltage is generated during the heating period by alternately turning on and off the power source during the heating period, the power source is switched on for a duty after switching on and off after switching off for a switch-off. Thus, an alternating voltage can advantageously be generated at the magnetic coil and, for example, by repeatedly switching on and off the voltage source advantageously good eddy currents for heating the gas valve can be generated. In this case, for example, the voltage applied to the magnetic coil voltage can advantageously be varied rapidly, resulting in an advantageously rapidly changing magnetic field, which can advantageously induce strong eddy currents in the electrically conductive components of the gas valve.

In an advantageous embodiment, after switching on the voltage source when reaching a maximum duty cycle and / or reaching a Abschaltstromstärke the voltage source is turned off again. The Abschaltstromstärke is none than the opening current. Thus, in an advantageously simple manner opening the gas valve, in particular of the fuel injector, be prevented within the heating period by the power source is switched off in good time after switching. The time of switching off the voltage source after switching on can thus advantageously be regulated, for example, in terms of time, over the maximum switch-on duration. The time of switching off after switching on can advantageously be regulated but also via the current through the magnetic coil by the voltage source is turned off when the current has reached the Abschaltstromstärke after switching on the power source.

It may also prove advantageous if the switch-on duration and / or the switch-off duration and / or the heating duration are determined by motor parameters. Engine parameters may include, for example, engine sizes and environmental variables such as engine temperature, gas temperature and fuel pressure, engine speed, engine load and, for example, duration and location of the regular energization for opening the gas valves configured as fuel injectors, for example, or one or more of these values may be included in the engine parameters. Thus, the method can be advantageously adapted to the operating conditions and the control of the engine.

Advantageously, the magnet coil is subjected to a voltage, in particular of a booster voltage, which is greater than a battery voltage, for example as the battery voltage of a starter battery for the motor vehicle. By a booster voltage can advantageously be compared to a lower battery voltage, for example, the battery voltage of the starter battery for the motor vehicle, when the power source, the magnetic field is built faster and as a result, stronger eddy currents and a higher heating effect.

Advantageously, the switching off of the voltage source by means of a quick-release device. By a quick extinguishing device, for example with a Zener diode, a steep current drop edge can be achieved. Thus, an advantageous rapid magnetic field degradation and consequently stronger eddy currents and thus a higher heating effect can be achieved.

In an advantageous embodiment, it is provided that part of the coil energy dissipated when the voltage source is switched off by means of the quick-release device is recovered for the generation of the voltage, in particular for the generation of the booster voltage.

In an advantageous embodiment, a start-up of a starter is delayed by the duration of the heating and starting of the starter for engine start and metering of fuel by, for example, a gas valve designed as a fuel injector only begins after the heating time.

It may prove advantageous if the solenoid is acted upon by an opening current during at least one opening period before and / or after the heating period, wherein the opening current is greater than or equal to the opening current, so that the fuel injector is opened during the opening period. Thus, in the case of a fuel injector as a gas valve, the fuel injector can also be heated, for example, during a heating period between two opening periods. By heating also between two opening operations, short-term cooling of the fuel injector during operation can advantageously be prevented and it can advantageously be a continuous operation of the fuel injector without sticking, for example, the elastomer to the metal, for example in the region of the metal-elastomeric seal, For example, between two opening periods, be ensured.

Also advantageous is a computer program that is set up to carry out the method.

Also advantageous is a device for heating a gas valve, in particular a fuel injector, wherein the device comprises at least one control device and at least one gas valve.

Further advantageous is a motor vehicle with the device.

list of figures

• 1 ein Ausführungsbeispiel eines als Kraftstoffinjektor ausgebildeten Gasventils,
• 2 ein beispielhaftes Spannungs-Zeit-Profil und ein beispielhaftes Strom-Zeit-Profil während der Heizungsdauer des erfindungsgemäßen Verfahrens,
• 3 ein Ablaufdiagramm eines Ausführungsbeispiels des erfindungsgemäßen Verfahrens,
• 4 eine schematisches Schaltbild,
• 5 ein Ablaufdiagramm des erfindungsgemäßen Verfahrens.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. Show it

• 1 an embodiment of a gas injector designed as a gas valve,
• 2 an exemplary voltage-time profile and an exemplary current-time profile during the heating period of the method according to the invention,
• 3 a flowchart of an embodiment of the method according to the invention,
• 4 a schematic circuit diagram,
• 5 a flow diagram of the method according to the invention.

Embodiments of the invention

The inventive method and the inventive device for heating a gas valve 31 with a magnetic coil 36 by generating eddy currents in this application is exemplified by a fuel injector 31 for the injection of a gaseous fuel, for example, CNG (compressed natural gas,) formed gas valve 31 described. The gas valve 31 but can also be a gas valve, for example 31 with a magnetic coil 36 for the metering of LNG (liquefied natural gas), in which, for example, metal-metal seals can stick together by low temperatures and can be heated by the method and the device. Furthermore, it may be at the gas valve 31 with magnetic coil 36 For example, to an electrically controlled pressure regulator or an electric shut-off valve (shut off valve), or other gas valves 31 with magnetic coil 36 in which it can lead to a bonding of metal-elastomer seals or other seals such as metal-to-metal seals by low temperatures.

1 shows a section through an embodiment of a fuel injector 31 trained gas valve 31 with a magnetic coil 36 , The fuel injector 31 is for example intended for injection or metering of a medium to be injected, for example for internal combustion engines. That through the fuel injector 31 In particular, a gaseous fuel, for example natural gas (compressed natural gas, CNG), may be present. The fuel injector 31 may be provided, for example, for the injection of the gaseous fuel in an operated with the gaseous fuel internal combustion engine of a motor vehicle. The fuel can, for example, via a feed called rail at least one fuel injector 31 be supplied. The fuel injector 31 may for example be designed for use in a gas engine or in a fuel cell and for controlling a natural gas flow or the hydrogen flow from an inflow side 38 to a downstream side 39 serve.

The fuel injector 31 For example, has a multi-part housing 32 in which the magnetic coil 36 is arranged, for example, a guide sleeve 33 embraces. In the guide sleeve 33 is a substantially tubular plug 34 fixed, in which a spiral spring 35 is inserted, which represents a biasing spring and a magnet armature 37 acts, slidably along a longitudinal axis of the fuel injector 31 in the guide sleeve 33 is arranged. The magnet armature 37 , which is formed substantially tubular, has an interior, which with the inflow side 38 of the fuel injector 31 is connected and from the radial outflow holes 40 and an axial outflow hole 41 branch. The radial outflow holes 40 lead to a high pressure room 42 from the magnet armature 37 , from the guide sleeve 33 and from a seat plate 45 is limited. The axial outflow hole 41 leads to the front of the magnet armature 37 ,

In this embodiment of the fuel injector 31 serves the magnet armature 37 as a valve closure member and has in its the plug 34 facing away from an elastomeric seal 44 that with the seat plate 45 made of metal, so that outflow openings 46 are controllable in the seat plate 43 are formed. In the closed state of the fuel injector 31 lies the elastomer seal 44 on the seat plate 45 where it forms the metal-elastomer seal and closes the outlet openings 46 , The magnetic coil 36 can be acted upon by a current, causing the armature 37 with the elastomer seal 44 is lifted and the outflow openings 46 thus be released. Thus, the fuel injector 31 by energizing the magnetic coil 36 openable, for example, when the current through which solenoid 36 is greater than an opening current strength lo, which is used to open the fuel injector 31 necessary is.

At low temperatures, it may happen that the elastomeric seal 44 at the clapboard 45 sticks and thus releasing the outflow openings 46 and thus opening the fuel injector 31 difficult or hindered. For example, in the case of a cold start, the elastomer seal may become stuck 44 on the seat plate 45 come. Such sticking can be prevented by the fuel injector 31 , in particular in the region of the metal-elastomer seal, is heated, so that adhesion is advantageously prevented.

Heating the fuel injector 31 For example, by induction of eddy currents in electrically conductive parts of the fuel injector 31 and by the heat generated by the eddy currents in the electrically conductive parts. For example, eddy currents in the armature 37 be generated. One in the magnet armature 37 generated heat can heat directly in the region of the metal-elastomer seal and prevent sticking of the metal-elastomer seal.

By the method described in the present application are eddy currents in electrically conductive parts, in particular the armature 37 , the fuel injector 31 induces around the fuel injector 31 to heat and thus prevent sticking of the metal-elastomer seal and thus a safe and reliable opening of the fuel injector 31 to ensure.

This is the solenoid 36 of the fuel injector 31 used. The magnetic coil 36 is caused by a voltage source 21 . 22 from a stream 13 applied. In the process, the solenoid coil 36 during at least one heating period 49 . 50 according to a voltage-time profile 10 with an alternating voltage 12 applied. This is done by the magnetic coil 36 generates an alternating magnetic field in the electrically conductive parts of the fuel injector 31 Generated eddy currents. The eddy currents thus generated heat the electrically conductive parts of the fuel injector 31. Here is the stream 13 during the entire heating period 49 . 50 smaller than the opening current Io, which opens the fuel injector 31 necessary is. Thus, the fuel injector remains 31 during the entire heating period 49 . 50 closed. The opening current intensity Io can be, for example, from the voltage source 21, 22, for example from the booster voltage 21 or, for example, also depend on a gas pressure, for example in a rail arranged upwards in the flow direction of the fuel injector 31. The opening current intensity Io is shown as constant over the time course in the figures, but it can also vary, for example, over the time course of the method.

In 2 are an example of a voltage-time profile 10 and a resulting current-time profile during a heating period 49 . 50 shown. The at the magnetic coil 36 voltage applied 12 is in time with the magnet coil 36 flowing electricity 13 represented over the course of a time t. In the diagram in 2 Accordingly, the time t is plotted on the right and the voltage U (t) dependent on the time t and the current intensity I (t) dependent on the time t are plotted upward. The magnetic coil 36 gets from the alternating tension 12 loaded and in the solenoid 36 flows a resulting stream 13 ,

The alternating voltage 12 during the heating period 49 . 50 For example, by switching on alternately 15 and off 16 the voltage source 21 . 22 during the heating period 49 . 50 be generated. This is in 2 based on a final stage signal 11 is represented by the voltage source 21 . 22 when switching on 15 switched on and off. The voltage source 21 . 22 is after switching on 15 for a duty cycle 17 switched on. The voltage source 21, 22 is turned off 16 is switched off again and after switching off 16 for a switch-off 18 switched off. In the process is during the heating period 49 . 50 for example, alternately and repeatedly turned on and off again. In other words, change during the heating period 49 . 50 duty cycles 17 with switch-off periods 18 from. In this embodiment, by way of example, all turn-on durations 17 are the same length and all turn-off periods 18 of equal length. During the heating period 49 . 50 can the switch-on times 17 and / or the switch-off periods 18 but also be different in length. This is based on the output stage switching signal 11 shown switching on 15 and off 16 the voltage source 21 . 22 results in the in 2 illustrated voltage curve of the voltage 12 and current flow of the stream 13 ,

To open the fuel injector 31 during the heating period 49 . 50 to prevent is the electricity 13 during the entire heating period 49 . 50 smaller than the opening current strength lo from the magnet armature 37 is moved and the fuel injector 31 thus opens. This can be done, for example be achieved that the voltage source 21 . 22 when the electricity 13 a turn-off current la is reached again. The Abschaltstromstärke la is smaller than the opening current intensity lo. Furthermore, the opening of the fuel injector 31 during the heating period 49 . 50 be achieved by that the voltage source 21 . 22 when reaching a maximum duty cycle 19 is switched off again. The maximum duty cycle 19 starts, for example, after switching on 15 the voltage source 41 . 22 , Becomes the voltage source 21 . 22 For example, when reaching the maximum duty cycle 19 turned off, so is the maximum duty cycle 19 equal to the duty cycle 17 , The current 13 in the magnetic coil 36 Thus, for example, by the maximum duty cycle 19 limited so that the fuel injector 31 during the heating period 49 . 50 not open.

Advantageously, the heating period can be controlled 49,50, for example, map-dependent. In the map, for example, engine sizes and environmental variables such as engine temperature, fuel temperature, fuel pressure, engine speed, engine load and duration and location of the regular current to open the fuel injector 31 received.

In one embodiment of the method may also after switching off 16 the voltage source 21 . 22 switching on 15 the voltage source 21,22 take place only when one in the fuel injector 31 stored coil energy is largely degraded again. This can advantageously be an energy accumulation in the solenoid, for example, visible at a virtually instantaneous current jump when switching, can be prevented.

In the method, the duty cycle 17 and / or the switch-off duration 18 and / or the duration of heating 49 . 50 also be determined by motor parameters. Engine parameters may include, for example, engine sizes and environmental variables such as engine temperature, gas temperature and fuel pressure, engine speed, engine load, and also duration and location of the regular energization to open the fuel injectors, or one or more of these values may be included in the engine parameters. The heating time 49 . 50 For example, it can also be controlled depending on the map. In the map, for example, engine sizes and environmental variables such as engine temperature, fuel temperature, fuel pressure, engine speed, engine load and duration and location of the regular current to open the fuel injector 31 received.

Before and / or after the heating period 49.50, the solenoid can 36 during at least one opening period 51 from an opening stream 14 be acted upon, the opening current 14 greater than or equal to the opening current Io, so that the fuel injector 31 during the opening period 51 is opened. This is in 3 illustrated by a flowchart.

In 3a is a start request 53 after commissioning of the motor vehicle with KL15 Ein 52 shown. 3b shows the start request as in the method 53 for example, a preheating time 55 is delayed and then a start run 46 is initiated. In 3c the engine speed n (t) is shown as a function of time t. How out 3b and 3c can be seen accelerates the start of the race 46 the engine to a starter speed. After the onset of combustion takes place in this embodiment, starting from the starter speed a speed up.

Parallel to the starter in 3b and the engine speed n (t) in 3c is in 3d the energization of the solenoid 36 with the flow 13 represented in the process. During the heating periods 49,50 becomes the solenoid coil 36 with an alternating voltage 12 which is one in 3d illustrated alternating storm 13 in the magnetic coil 36 causes. The current 13 is during the entire heating periods 49,50 smaller than an opening current Io, the opening of the fuel injector 31 is necessary. A first heating period 49 , serves as in 3 shown, preheating the fuel injector before it is opened for the first time after commissioning and injects fuel into the engine. The first heating period 49 can thus serve to improve the cold start of the engine and the fuel injector 31 to heat up before the first injection process after starting the engine.

Furthermore, in 3d For example, a current flow of the current 13 during opening times 51 shown. During opening times 51 becomes the magnetic coil 36 through an opening flow 14 applied, which is greater than or equal to the opening current Io. Thus, the fuel injector opens 31 during opening times 51 and injects fuel into the engine. In 3d are exemplary two opening times 51 shown.

In 3d are next to the first heating period 49 additional second heating periods 50 shown. The second heating period 50 can, for example, as in 3d shown between two opening times 51 , before an opening period 51 and after an opening period 51 be arranged. This will be during the second heating period 50 after opening and closing the fuel injector 31 Eddy currents in the fuel injector 31 induced and the fuel injector 31 warmed up before the fuel injector 31 again during another opening period 51 is opened. In this way, for example, during the injection of fuel occurring cooling of the advantageous fuel injector 31 be counteracted. So can the fuel injector 31 for example, by an alternating current 13 be heated below the opening current Io and this, for example, only by the opening times 51 for opening the fuel injector 31 be interrupted, in which the current 13 is greater than the opening current Io.

As in 3 illustrated in the method, for example, a first heating period 49 for preheating the fuel injector 31 be provided, then several second heating periods 50 be provided, between which the fuel injector 31 is opened. During an opening period 51 is, for example, no Wirbelstromheizen the fuel injector 31 intended.

4 shows an example of a schematic interconnection, through which the method can be performed. The voltage 12 is caused by a voltage source 21 . 22 provided. The voltage source 21 . 22 For example, a battery voltage 22 be, so for example the battery voltage 22 the starter battery of the motor vehicle. For example, the voltage source 21, 22 may also be a booster voltage 21 act, which is greater than the battery voltage 21 , that is, for example, greater than the battery voltage 21 the starter battery of the motor vehicle. Furthermore, in 4 an example of a switch 23 for switching the voltage source 21 . 22 and a power resistor 24 , Further shows 4 schematically several parallel-connected magnetic coils 36 of fuel injectors 31 , The magnetic coils 36 but can also be connected in series, for example, or it can, for example, a single solenoid 36 available. Furthermore, in 4 another switch 26 and a current sense resistor 27 shown. The current measuring resistor 27 can be used to determine the current 13 can be used, which can then be adjusted, for example, with the Abschaltstromstärke Ia to a timely turn off 16 the voltage source 21 . 22 during the heating period in a 49, 50 ensure that the fuel injector 31 during the heating period 49 . 50 not open. By means of the switch 23 For example, a selection of the voltage source 21 . 22 That is, for example, between the battery voltage 22 and the booster voltage 21 respectively. The magnetic coil 36 can thus with a tension 12 , for example with a booster voltage 21 , which is greater than the battery voltage 22 , for example, greater than the battery voltage 22 the starter battery of the motor vehicle. By means of the further switch 26 can turn on 15 and switching off 16 the voltage source 21 . 22 for example during the heating period 49 . 50 respectively. The energization of the magnetic coil 36 of the fuel injector 31 for opening the fuel injector 31 , so for example during the opening period 51 , for example, by means of switching 23 for example, from both voltage source 21 . 22 that is the battery voltage 22 and the booster voltage 21. Here, for example, as an additional function, the current control based on the current measuring resistor 27 added. The desk 23 and the other switch 26 For example, by the in 4 shown control 28 driven. For rapid magnetic field degradation, for example, a quick extinguishing device may be provided by means of the switching off 16 the voltage source 21,22 takes place.

Advantageously, for example, a part of the off 16 the voltage source 21,22 by means of the quick-release device degraded coil energy to generate the voltage 12 , for example, the booster voltage 21 be recovered.

5 shows an example of a flowchart of an embodiment of the method for heating a fuel injector 31 with a magnetic coil 36 ,

In step 300 the procedure begins.

In step 301 For example, a 52 shut-off valves in the fuel circuit are energized with KL15, so that the fuel operating pressure at the fuel injector 31 provided.

In step 302 the start request is expected, the heating fuel injector 31 triggers.

In step 303 For example, the first heating period takes place 49 for preheating the fuel injector 31 by means of eddy currents, wherein the magnetic coil 36 with an alternating voltage 12 is applied, so that in the fuel injector 31 Eddy currents are induced, with the current 13 during the entire first heating period 49 is less than the opening current Io. The length of the first heating period 49 can be determined for example via a map. Engine characteristics and environmental variables such as, for example, engine temperature, fuel temperature, fuel pressure, engine load or intake pressure can be included in the characteristic map.

In step 304 for example, the starting run 46 initiated.

In step 305 For example, the second heating period takes place 50 for additional heating of the fuel injector 31 by means of eddy currents, wherein the magnetic coil 36 with an alternating voltage 12 is applied, so that in the fuel injector 31 Eddy currents are induced, the electricity 13 during the entire second heating period 50 is less than the opening current Io. The length of the second heating period 49 can be determined for example via a map. In the map, for example, engine sizes and environmental variables such as engine temperature, fuel temperature, fuel pressure, engine speed, engine load and duration and location of the regular current to open the fuel injector 31 received.

In step 306 the normal operation of the engine is initiated.

In step 307 the procedure ends.

Of course, further embodiments and hybrid forms of the illustrated embodiments are possible.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1950409 B1 [0004]

Claims (12)

Method for heating a gas valve (31), in particular a fuel injector (31), with a magnet coil (36) by generating eddy currents, wherein the gas valve (31) can be opened by energizing the magnet coil (36), the magnet coil (36 ) is acted upon by a current source (13) through a voltage source (21, 22), characterized in that the magnetic coil (36) has at least one heating period (49, 50) corresponding to a voltage-time profile (10) with an alternating voltage (12) is applied, so that in the gas valve (31) eddy currents are generated, wherein the current (13) during the entire heating period (49,50) is smaller than an opening current strength (Io), which is used to open the gas valve (31) necessary is. Method according to Claim 1 characterized in that the alternating voltage (12) is generated during the heating period (49,50) by alternately turning on (15) and turning off (16) the voltage source (21,22) during the heating period (49,50) Voltage source (21,22) after switching on (15) for a duty cycle (17) is turned on and after turning off (16) for a turn-off (18) is turned off. Method according to Claim 2 , characterized in that after switching on (15) of the voltage source (21,22) on reaching a maximum duty cycle (19) and / or reaching a Abschaltstromstärke (la), the voltage source (21,22) is turned off again, the Abschaltstromstärke (la) none is as the opening current (Io). Method according to one of Claims 2 to 3 , characterized in that the switch-on duration (17) and / or the switch-off duration (18) and / or the heating duration (49, 50) are determined by motor parameters. Method according to one of the preceding claims, characterized in that the magnetic coil (36) with a voltage (12), in particular with a booster voltage (21) is applied, which is greater than a battery voltage (22). Method according to one of the preceding claims, characterized in that the switching off (16) of the voltage source (21,22) by means of a quick extinguishing device. Method according to Claim 6 , characterized in that a part of when coil (16) of the voltage source (21,22) degraded by means of quick extinguishing coil energy of generation of the voltage (12) is recovered. Method according to one of the preceding claims, characterized in that starting (47) of a starter is delayed at least by the heating period (49, 50) and only after the heating period (49, 50) starting (47) of the starter for an engine start and a Metering of fuel by the fuel injector (36) begins. Method according to one of the preceding claims, characterized in that the solenoid coil (36) during at least one opening period (51) before and / or after the heating period (49,50) is acted upon by an opening current (14), wherein the opening current (14) is greater than or equal to the opening current (Io), so that the fuel injector (31) is opened during the opening period (51). Computer program that is set up, the procedure according to one of Claims 1 to 9 perform. Device for heating a gas valve (31), in particular a fuel injector (31), the device comprising at least one control device and at least one gas valve (31), the device being adapted to carry out the method according to one of Claims 1 to 9 perform. Motor vehicle with device after Claim 11 ,

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