KR101473778B1 - Method and apparatus for heating at least one injector of an engine - Google Patents

Abstract

The present invention relates to a method and apparatus for heating one or more injectors, for example a gas injector of a vehicle.

It is therefore an object of the present invention to provide an apparatus and method for preventing a valve pin from sticking to a valve seat of an injector at low temperatures.

This object is achieved by a device according to the invention and a method according to the invention for heating one or more injectors of an engine. In this case, the method comprises the steps of providing an engine control unit and an additional control device, wherein the engine control unit is operable to operate an additional control device and a method whereby the injector can be heated and / or executed by moving its valve pin , Actuating the injector by the further control device.

Injector, heating, sticking

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus and an apparatus for heating one or more injectors,

The present invention relates to an apparatus and a method for heating one or more injectors, for example a gas injector of an automobile.

For example, such gas injectors may be used in conjunction with other fuel injectors, such as gasoline injectors, to enable the user to switch between operation by gas and operation by other fuels. In gasoline-powered vehicles, the cost of fuel can be significantly reduced in such vehicles, as the end-user costs double the cost of a vehicle driven by a combination of gas and gasoline, for example natural gas.

In prior art gas injectors, the valve seat and valve needle of the valve are made of a metal / metal pair material. However, this has the disadvantage that it can not seal the valve well.

Alternatively, instead of a metal / metal pair material, a metal / base metal may be used to form the valve. In this case, the base metal used for the valve seat is, for example, an elastomer which is a hard rubber. The valve pin itself is still made of metal. The formation of the valve seat with rubber has the advantage that, as in the prior art, the sealing of the valve and / or the injector is improved as compared to when the valve seat is made of metal. However, the metal / rubber pair may experience a "sticking " or" seizing "phenomenon of the valve needle in the rubber valve seat, for example in cold ambient conditions, such as immediately below 0 占 폚. Therefore, under these conditions, the gas injector must be heated to compensate for such defects. Without such a valve heating function, a gas injector with a valve seat made of rubber can not operate at temperatures below zero degrees, which is a disadvantage to the consumer.

It is therefore an object of the present invention to provide an apparatus and method for preventing a valve pin from sticking to a valve seat of an injector at low temperatures.

According to the invention, this object is achieved by an engine control unit and an additional control device, wherein the additional control device is arranged to prevent the valve pin of the injector from moving in its valve seat, The injector is operated in accordance with the pulse profile of the engine control unit.

This has the advantage that it makes it possible to use an injector with a valve seat made of nonmetal, for example rubber. As described above, such injectors have the advantage of having better sealing properties than injectors having metal / metal pairs. This way also ensures that the movement of the valve pin will cause the injector to heat up and prevent the valve pin from sticking to the valve seat, thus ensuring that the valve pin can not quickly stick to the valve seat, especially at low temperatures. An added advantage is that the conventional engine control unit can be used as the actual control of the injector is carried out by the additional control device, which uses the pulses from the engine control unit for this purpose.

In another embodiment of the present invention, an additional control device controls the injector in accordance with the pulse profile of the engine control unit used, for example, to operate another fuel injector. The injector is, for example, a gas injector, while the other injector is another fuel injector, such as, for example, a gasoline injector. By means of the pulse profile, the engine control unit, on the other hand, instructs the additional control device to perform the injection operation of the gasoline injector, while, on switching to the gas mode, the valve pin does not stick to the valve seat, Prepare the gas injector to ensure reliable operation of the injector.

According to another embodiment of the present invention, in order to prepare the injector, the emptying of the rail connected to the gas injector is performed first. This ensures that no gas is present in the rail at the start of the heating of the injector. By emptying the rails, the length of the pulse for actuating the injector is selected so that the valve is not open or opened for a short period of time. The length of the pulse in this case is gradually increased to a predetermined maximum value, for example, of this operating phase, in order to prevent a sudden drop in pressure. When the rail is finally emptied, an actual heating operation may be initiated, during which the valve pin is moved in a reciprocating and / or open and closed position at a maximum amount. The length of the pulse may be set to, for example, a maximum value in this case, and thus may not require a gradual increase from this operating phase to the maximum value. This has the advantage, on the other hand, that the gas injector is ready for reliable operation and, on the other hand, that the running behavior of the engine during preparation is not compromised by, for example, a sudden sudden pressure drop in the rail.

In another form of embodiment, the heating of the injector is terminated, for example when the temperature at the rail exceeds a predetermined threshold, for example when the injector is heated sufficiently to allow the valve pin to move freely in the injector. This has the advantage that it is possible to prevent overheating of the injector or rail.

In another form of embodiment according to the present invention, it is optionally possible to additionally provide a preparatory step to be carried out before the actuation step of emptying the rails. In this preparatory step, the additional control device determines the length of the pulse for actuating the injector such that the injector is not opened. In other words, the valve pin hardly moves or does not move at all. In this case, some initial preheating of the injector may be generated by the electrical voltage realized by the pulse, so that the injector need not move between the open and closed positions.

In another form of embodiment according to the invention, the engine control unit activates an additional control device, for example via a CAN data link, so that the further control device executes the respective operating phase for heating the injector. The additional control device calculates and / or determines the operating time of the injector in each operating phase. This has the advantage that other operations, such as the activation of each activation phase, are performed by the engine control unit, which need not be performed in real time, while operations such as the execution of the activation phase can be performed in real time by the additional control device. This enables the system including the engine control unit and the additional control device to be configured simply and economically.

In another embodiment according to the present invention, the emptying of the rails is carried out in a gentle and / or controlled manner so that the running behavior of the engine is not affected. Particularly, by gradually increasing the pulse length to the maximum value in this operation step, a rapid pressure drop and consequent unintended rotation speed change can be reliably prevented.

In another embodiment of the present invention, for example, when a situation occurs in which the temperature of the rail, the temperature of the injector, or the ambient temperature is below the threshold value, heating of the injector is performed where the ambient temperature limit is, for example, / RTI > This has the advantage that the heating function of the injector is only carried out in an important range and it is also possible to rely on values already determined for other devices in the engine control unit.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, a very simplified diagram is shown in Fig. 1, which shows a structure according to the invention of a control device 10 for heating a gas injector of a vehicle. In this case, the device 10 comprises an engine control unit (MSG) of the type typically used in vehicles. In addition to this engine control unit MSG, an additional control device GAS_BOX is provided according to the invention. Which is connected to the engine control unit (MSG), for example by the CAN data line 12. The additional control device (GAS_BOX) is used to operate the gasoline-and gas-injector in accordance with the engine control unit (MSG).

Compared to the manner in which the engine control unit directly operates the gasoline- and gas-injectors, the additional control unit GAS_BOX has the advantage that it can be simply connected as an additional part of the engine control unit used in the vehicle. In the manner in which the engine control unit directly operates the injector, on the other hand, the engine control unit provided to the vehicle can not be used, but rather for this purpose to realize the heating function in the case of a gas injector and to operate the gasoline- and gas- There is a need to provide a specially configured engine control unit. Thus, modification of the vehicle may be accompanied by complete replacement of the engine control unit, while it may be maintained in embodiments in accordance with the present invention.

According to the invention, the additional control device (GAS_BOX) is connected to one or more gasoline injectors 14 and one or more gas injectors 16, or as shown in figure 1, for example four gasoline- and four gases And is connected to the injectors 14 and 16. The engine control unit MSG delivers the control pulse IV_IN to the additional control unit GAS_BOX to activate the gasoline- and gas-injectors 14, 16. The mode (MOD_1-3) to be executed via the CAN data link 12 is communicated to the additional control device GAS_BOX.

In this system, it is possible to switch between the gasoline mode and the gas mode. In this case, according to the invention, the system structure in the form of a master (engine control unit (MSG) / slave (GAS_BOX)) concept is used, so that for the gas valve heating function, Mode, which is preferably because the additional control unit GAS_BOX does not carry out independent injection without being transmitted by the engine control unit (MSG) for safety reasons. In this case, the injector heating function is achieved by movement and / or opening and closing of the gas injector, but without simultaneous injection of the appropriate amount of gas. In this case, a low-pressure shut-off valve disposed upstream of the gas rail (not shown) may be provided, which is kept closed during the heating function to prevent subsequent gas flow from the pressure reducer.

If the vehicle is in gasoline mode, the gasoline injector is operated by an additional control device (GAS_BOX). In this case, the additional control device GAS_BOX transmits, for example, the signal and / or pulse profile IV_IN of the substantially unchanged engine as a single signal IV_OUT_petrol to the gasoline injector. In the gasoline mode, the gas injector is simultaneously prepared and / or heated to reliably operate the gas injector upon conversion from the gasoline mode to the gas mode. This means that it is ensured that the valve pin of each gas injector does not "stick" to the valve seat.

For this purpose, the additional control device GAS_BOX is adapted to change and / or regulate the signal and / or pulse profile IV_IN of the engine control unit MSG in a suitable manner, in particular at low temperatures, Thereby preventing "sticking" In this case, adjustment of the pulse profile (IV_OUT_GAS) is performed, for example, in three stages (MOD_1 to MOD_3). In the first step (MOD_1), the gas injector is operated without, for example, causing actual opening of the gas injector. In the second step (MOD_2) the metered discharge of the shut off gas rail is made up of a suction manifold through a gas injector. In this case, the pressure PGAS_L in the gas rail decreases.

The heating of the gas injector in the three steps MOD_1 to MOD_3 will be described in detail with reference to Fig. Fig. 2 shows three steps (MOD_1 to MOD_3) of the valve pin control according to the invention in order to reliably prevent "sticking" of the valve pin to a non-metallic valve seat, for example, Fig.

The diagram shows the pulse profile IV_IN as the pulse profile IV_IN is transferred from the engine control unit MSG to the further control device GAS_BOX. In the additional control device GAS_BOX, the pulse profile IV_IN is accepted unchanged, for example, and the gasoline injector is operated by the selected pulse profile IV_OUT_PETROL.

The pulse profile IV_OUT_GAS is additionally marked and the additional control device GAS_BOX is capable of preventing this valve profile from " The gas injector is operated. The additional control device GAS_BOX appropriately changes the pulse profile IV_OUT_GAS for this purpose to operate the gas injector in such a way that the gas injector is warmed and / or heated. In this case, the pulse profile is divided into steps (MOD_1) to (MOD_3). That is, the pulse profile (IV_OUT_GAS) of the gas injector is coupled to the pulse profile (IV_IN) of the engine control unit (MSG) and / or the pulse profile of the gasoline injector. This means that the low phase 18 of the pulse of the engine control unit MSG is matched to the low phase 20,21 of the pulse for operating the gas injector in a manner dependent on the system.

The first step (MOD_1) is then performed first to move the valve pin in an appropriate manner so that the valve pin does not "stick " to the valve seat. In this case, the performance quantity (LV_HEAT_GAS_IV_MOD_1) is set to 1, that is, the first step (MOD_1) is activated, and the engine control unit (MSG) outputs the output to the additional control device (GAS_BOX) via the CAN data link And the additional control device GAS_BOX starts the first step (MOD_1).

In the first step MOD_1 the gas injector is operated by a pulse of the further control device GAS_BOX where the length of the high phase 24 of the pulse of the pulse profile IV_OUT_GAS is controlled by the additional control device GAS_BOX, So that the valve pin does not move at all or moves very little so that only the electric voltage is applied. In the latter case, the valve pin opens only to the extent that the injector is not open and ensures that no gas escapes from the gas injector. That is, in the first step (MOD_1), the operating time and / or the clock time (T_ON_HEAT_GAS_IV) of the gas injector is small such that the gas injector does not open including all the tolerances. This means that the operating time T_ON_HEAT_GAS_IV is less than the battery voltage correction value TI_ADD_DLY_GAS (basic position) for the gas injector, for example. In this case, the " non "-activation time (T_OFF_HEAT_GAS_IV) is applied so that when the gas valve or the gas injector is opened, the next operation time T_ON_HEAT_GAS_IV can be reliably closed . Therefore, since no pressure relief occurs in the gas rail, the pressure PGAS_L in the gas rail shown in Fig. 2 becomes substantially constant in the first step (MOD_1).

The second stage (MOD_2) is then utilized to discharge the connected gas rails in a gentle and / or controlled manner, correspondingly gradually releasing the gas rail pressure PGAS_L in doing so. In this case, the gas rails are emptied through one or more gas injectors or valves in a controlled manner such that the operation of the vehicle is not substantially negatively affected.

To start the second stage (MOD_2), the engine control unit (MSG) sets the performance value (LV_HEAT_GAS_IV_MOD_2) to 1, that is, the second stage (MOD_2) is activated. The engine control unit MSG relays it to the additional control unit GAS_BOX via the CAN data link 12 and instructs the additional control unit GAS_BOX to start the second step MOD_2.

In the second step (MOD_2), the pulse length and / or high phase 24 of the gas injector is increased, as shown in FIG. In this case, the length of the pulse is selected so that the valve pin reciprocates much more than in the first step (MOD_1). More precisely, the injector is moved back and forth by a pulse to such an extent that the injector is only slightly repeatedly opened for a short period of time to allow controlled pressure relief from the gas rail. In this case, the maximum operating time (T_ON_HEAT_GAS_IV_MOD_2_MAX) of the second step (MOD_2) is determined and / or applied such that the injector and / or valve includes all tolerances, e.g. As shown in Fig. 2, the pressure PGAS_L gradually decreases in the gas rail. Thus, a "finely" metered discharge of the shut off gas rail is made through the gas injector, for example, to the intake manifold of the engine.

On entry to the second step (MOD_2), for example all the variables are initialized to values from the first step (MOD_1). The operation time T_ON_HEAT_GAS_IV is gradually increased or increased until the maximum value T_ON_HEAT_GAS_IV_MOD_2_MAX of the second step MOD_2 is reached or the rail pressure PGAS_L of the gas rail reaches or falls below the threshold value.

During this process, very abrupt pressure drops occur in the gas rails, which can lead to failures due to pressure drop. In the case of a very abrupt pressure drop, a very large amount of gas is discharged through the gas injector, whereby not all gases may be sufficiently combusted, resulting in an excessively rich gas mixture, . This may result in irregular operation of the engine correspondingly.

Thus, if the pressure drop in the gas rail is made too large, re-initialization is performed. This means that the operating time in the second step (MOD_2) is once again started and slowly increases, for example, with the operating time and / or variable of the first step (MOD_1). As already described, the operating time in the first step (MOD_1) is configured such that the valve pin does not move at all or moves only slightly so that the injector is not opened in any case. From this operating time, in this case, the second step (MOD_2) is repeated until the maximum operating time T_ON_HEAT_GAS_IV_MOD_2_MAX of the second step (MOD_2) has reached or the rail pressure PGAS_L of the gas rail has reached a limit of, for example, 0 bar By increasing the operating time and / or the length of the pulse until it reaches < RTI ID = 0.0 > a < / RTI > Such a newly incrementing step may start after a predetermined delay time (C_TDLY_HEAT_GAS_IV_INC_STOP), for example. In this case, delay time (C_TDLY_HEAT_GAS_IV_INC) may be optionally or additionally provided after each incremental step to wait until the system responds.

If the rail pressure of the gas rail PGAS_L finally reaches the limit of, for example, 0 bar, the transition to the third step (MOD_3) can be made after the time applied. To start the third step (MOD_3), the engine control unit (MSG) sets the performance value (LV_HEAT_GAS_IV_MOD_3) to 1, that is, the third step (MOD_3) is activated. The engine control unit MSG relays it to the additional control unit GAS_BOX via the CAN data link 12 in a corresponding manner and instructs the additional control unit GAS_BOX to start the third step MOD_2.

In the third step (MOD_3), the length of the pulse is once again increased to reciprocate the valve pin more greatly. In this case the length of the pulse can be maximized such that the length of the pulse for controlling the gas injector corresponds substantially to 1: 1 to the pulse for controlling the gasoline injector. Since the gas rail has been emptied in the previous second step MOD_2, the pressure of the gas rail PGAS_L is still a constant value and / or 0 bar as shown in Fig. In the third step (MOD_3), as in the actual heating step, the valve pin is heated or heated by the generated movement of the valve pin, so that even at low temperatures, the valve pin does not stick to the valve seat of the rubber and ensures a reliable operating mode of the gas injector. That is, the first stage (MOD_1) and the second stage (MOD_2) are the preparation stage while the third stage (MOD_3) produces the largest heating capacity.

In the third step MOD_3, for example, the operating time T_ON_HEAT_GAS_IV is at its maximum, that is, the operating time substantially corresponds to the operating time of the gasoline injector. In other words, the length of the high phase 24 of the pulse for the gas injector is in this case the length of the high phase 22 of the pulse profile IV_IN of the gasoline injector and / or engine control unit MSG same. The "non" -operating time in the third step (MOD_3) may be set to zero, for example. This means that no additional low phase 21 is inserted between them in the high phase 24, as did the first phase (MOD_1) and the second phase (MOD_2). In this way the maximum heating capacity is provided.

The duration of the total operation for the injection pulse is limited by the maximum time (C_T_MAX_HEAT_IV_GAS_MOD_3). In this case the time (C_T_MAX_HEAT_IV_GAS_MOD_3) represents the pseudo PWM signal within the injection time (TI_PETROL_TIME) of the gasoline injector in order to limit the heating capacity in case of very high loads.

As described above, the heating function of the gas injector is realized by the master / slave concept including the engine control unit MSG and the additional control unit GAS_BOX. In principle, the described operation of the gas injector may be totally calculated by the additional control device GAS_BOX or the engine control unit MSG. However, the advantage of separating these calculations is that a smaller amount is communicated via the CAN data link 12, and moreover, a time-critical signal can be evaluated in the most advantageous place in this case It is a point. In other words, the engine control unit MSG performs calculations and / or operations that do not need to be executed in real time, while the additional control unit GAS_BOX performs calculations and / or operations to be performed, for example, in real time .

The additional control device GAS_BOX therefore performs the calculation and / or distribution of the pulses for operating the gas injector in accordance with the previously described three steps (MOD_1 - MOD_3), as well as the operation of the gasoline injector. On the other hand, the engine control unit MSG specifies, for example, by the additional control device GAS_BOX the timing at which the three stages (MOD_1 to MOD_3) are to be started and which of them is to be started. In this case, for example, subsequent quantities are transferred from the engine control unit (MSG) to the additional control device (GAS_BOX) via the CAN data link 12. First, the amount (LV_HEAT_GAS_IV_MOD_1-3) representing each of the stages (MOD_1, MOD_2, MOD_3) acts. Furthermore, an amount (TI_ADD_DLY_GAS) (basic position) indicating the battery voltage correction for the gas injector is transmitted. The following quantities are sent further:

- LV_HEAT_GAS_IV_MOD_1 - Heating with parameter setting 1, in which the operating time of the gas injector (TI_GAS_times) which is smaller than the battery voltage correction value (TI_ADD_DLY_GAS) (default position) for the gas injector is executed, thereby ensuring that no valve is open.

- LV_HEAT_GAS_IV_MOD_2 - heating to parameter setting 2, in which the operating time (TI_GAS_times) of the gas injector greater than or only slightly greater than the battery voltage correction value (TI_ADD_DLY_GAS) for the gas injector (basic position) is executed, ) At the end of the valve.

- LV_HEAT_GAS_IV_MOD_3 - Heating with parameter setting 3, here the maximum value for the operating time of the gas injector (TI_GAS_times) is applied to achieve the maximum heating capacity.

The parameter settings 1 to 3 include, for example, the following quantities:

(IP_X) for the operating time (IP_T_ON_HEAT_GAS_IV_MOD_x) of the valve of the gas injector for determining the high phase 24 of the operating time TI_GAS of the gas injector,

For the non-operating time 25 (IP_T_OFF_GAS_IV_MOD_x) of the valve of the gas injector to determine the low phase 20, 21 of the operating time TI_GAS for the three steps (x = 1 to 3) And includes an appropriate property map (IP_X).

The decision as to whether the injector heating is necessary is made, for example, in accordance with the gas rail temperature TGAS_L. Above the applicable threshold, the gas injector is recognized as "warm" If injector heating is required, three steps (MOD_1 - MOD_3) with an applicable period are executed and terminated in a "heating" state under normal conditions. After the gas injector has been heated, the transition to the gas mode must be carried out without any delay to prevent the gas injector from being restarted again "sticking ". This also applies to the overrun fuel cutoff phase in which the driver releases the accelerator. If these steps at a low temperature are longer than the predetermined and / or applied time, the function is changed to the "reset" state, in which the operating mode is switched back to gasoline to initiate a new injector heating cycle. In this case, it is in principle possible to omit the first step (MOD_1) and to execute only the second step (MOD_2) and the third step (MOD_3).

3, a diagram illustrating an example of the characteristics of the gas injector heating according to the present invention is shown. Here, the second step (MOD_2) in which the pressure release of the gas rail occurs is displayed. This diagram shows, on the one hand, a reduction of the pressure PGAS_L and at the same time shows the characteristics of the rotational speed of the engine and the characteristics of the valve operating time (T_ON_HEAT_IV_GAS) 24 of the gas injector. As can be inferred from the diagram, the valve operating time T_ON_HEAT_IV_GAS of the gas injector is set such that the operating time reaches the maximum value TI_ON_HEAT_GAS_IV_MOD_2_MAX of the second step (MOD_2), or when the rail pressure PGAS_L of the gas rail is 0 lt; RTI ID = 0.0 > bar < / RTI > In this case it can be deduced from the diagram that the injector can be operated in a controlled manner so that the optimum pressure reduction in the gas rail is obtained while the rotational speed of the engine is not adversely affected. In other words, a very abrupt pressure drop and thus, for example, the generation of a very rich gas mixture can be prevented in the second step (MOD_2) by the operation of an appropriate and controlled injector. In this case the regulated pressure gradient of the pressure PGAS_L is the result of the opening of the additional injector.

The present invention has been described with reference to an engine having a gasoline- and gas-injector. However, the present invention is not limited to a gasoline injector. The present invention can, in principle, be used in place of a gasoline injector, for example in any type of fuel injector, such as a diesel injector (as an example only).

Fig. 1 shows a diagram for explaining the structure of a control apparatus according to the present invention.

FIG. 2 shows a diagram illustrating three steps (MOD_1 - MOD_3) for heating the main unit according to an embodiment of the present invention.

FIG. 3 shows a diagram showing an example of the profile of gas injector heating according to the second step (MOD_2) of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

10 control device

12 CAN data link

14 Gasoline Injector

16 Gas injector

18 Low phase (engine control unit)

20 Low phase (gas injector)

21 Additional low phase (gas injector)

22 High phase (engine control unit)

24 High phase (gas injector)

Claims (15)

A method for heating one or more injectors (16) of an engine, a) providing an engine control unit (MSG) and an additional control device (GAS_BOX), said engine control unit activating said additional control device; And b) actuating the injector by the further control device such that the injector is capable of being heated, executed, or heated and executed by moving its valve pin; Lt; / RTI > Wherein step b) c) emptying the gas rail connected to the injector (16) by operating the injector, the length of the pulse for actuating the injector being selected such that the injector is only opened; And d) heating the injector once the gas rail is completely emptied, the length of the pulse for operating the injector being set to the maximum possible; ≪ / RTI > Injector heating method. The method according to claim 1, Characterized in that said additional control device (GAS_BOX) controls said injector in accordance with the pulse profile of said engine control unit. Injector heating method. 3. The method of claim 2, Characterized in that said additional control device (GAS_BOX) selectively activates one or more additional injectors for fuel injection by said pulse profile. Injector heating method. delete The method according to claim 1, Characterized in that the injector heating step is terminated when the temperature at the gas rail reaches or exceeds the predetermined limit to a predetermined limit which is sufficiently warmed that the valve pin can move freely in the injector. Injector heating method. The method according to any one of claims 1 to 3 and 5, The step b) optionally further comprises a preparation step b1) (MOD_1) The preparation step b1) is carried out prior to emptying the gas rail, Wherein the length of the pulse for actuating the injector in the preparation step b1) is selected so that the injector is not opened. Injector heating method. The method according to claim 6, (MSG) so that said additional control device executes individual operating steps such as at least one of the preparation step (MOD_1), said gas rail emptying step (MOD_2), and said injector heating step (MOD_3) Activates said additional control device (GAS_BOX) Characterized in that said additional control device determines the length of the pulse in the respective operating phase. Injector heating method. The method according to any one of claims 1 to 3 and 5, Characterized in that the step of emptying the gas rail is carried out in a controlled manner in which the running behavior of the engine is not affected. Injector heating method. The method according to any one of claims 1 to 3 and 5, When the condition that at least one of the injector (16) and the gas rail is placed below the threshold, which is a time point at which the attachment of the valve pin starts to occur in the valve seat of the injector, is formed, heating of the injector Features, Injector heating method. An apparatus (10) for heating one or more injectors (16) of an engine, Wherein the apparatus comprises an engine control unit (MSG) and an additional control device (GAS_BOX) The additional control device activates the injector in accordance with the pulse profile of the engine control unit such that the injector is able to be heated or executed, or heated and executed, by moving its valve pin, Wherein said additional control device (GAS_BOX) for operating said injector suitably adjusts the pulse profile of said engine control unit (MSG) in operating steps, One operating step includes emptying the rail connected to the injector (MOD_2) The further control device regulates the length of the pulse for actuating the injector such that the injector is only open, Characterized in that in one actuating step the injector heating step (MOD_3), said further control device increases the length of said pulse so that an adequate heating capacity can be obtained, Injector heater. delete 11. The method of claim 10, The further control device (GAS_BOX) optionally has an additional preparation step (MOD_1) as an operating step, Characterized in that a pulse for actuating the injector in the further control device is selected in the additional preparation step so that the injector is not opened, Injector heater. 11. The method of claim 10, Characterized in that said additional control device (GAS_BOX) selectively activates one or more additional injectors for injecting fuel. Injector heater. 13. The method of claim 12, The additional control device GAS_BOX may be provided as an "add-on" part on the engine control unit MSG via the data link 12, Said additional control device activates said additional control device to execute individual operating steps (MOD_1 - MOD_3), such as one or more of a preparation phase, a rail emptying and an injector heating phase, Characterized in that said additional control device determines the length of the pulse of the respective operating phase. Injector heater. An engine having at least one injector (16) having an injector heater (10) according to any of claims 10 and 12 to 14, Wherein the injector (16) comprises a valve pin made of a metal and a valve seat made of a non- engine.

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