Abstract:
Because the relationship of the fuel injection quantity to a designated injection period differs in a half-lift region and a full-lift region, the purpose of the present invention is to bring the flow rate characteristics of an intermediate-lift region close to the flow rate characteristics of the full-lift region and improve the controllability of small fuel injection quantities. Provided are a peak current supply period in which a valve body of a fuel injection valve causes the magnetic force necessary for a valve-opening action to be generated, and a lift quantity adjustment period in which, after the peak current supply period, a current lower than the peak current is passed for a prescribed period; further provided is a current interrupt period in which a drive current is rapidly lowered before the lift quantity adjustment period.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a control device for electromagnetic fuel injection valve. 
       BACKGROUND ART 
       [0002]    Conventionally, a maximum injection quantity and a minimum injection quantity is defined as indices indicating a performance of a fuel injection valve for injecting fuel into an internal combustion engine. The quantity of fuel that a fuel injection valve can inject by keeping valve-opening of the fuel injection valve for a prescribed period (for example, one second) is defined as the maximum injection quantity. Injecting a larger injection quantity in a unit time is desired for requirement of the maximum injection quantity, and it can be addressed by increasing, as a determination factor, a setting value of a part represented by a valve-body lift quantity (moving quantity) in the fuel injection valve or a nozzle diameter provided in a distal end of the fuel injection valve. Meanwhile, the minimum injection quantity indicates the smallest injection quantity with which the fuel injection valve can stably inject, and the injection quantity is desirably required to be smaller. By the way, the injection quantity with which injection can be stably performed can be inevitably reduced by shortening a valve-opening instruction time for the fuel injection valve. However, the injection quantity varies between injection valves with identical specifications and identical driving instruction time. Therefore, the variation in the injection quantity falling within a prescribed range is set as a requirement. 
         [0003]    In recent years, technological development for widening the range (hereinafter referred to as a dynamic range) between the maximum injection quantity and the minimum injection quantity that has been already mentioned is actively made for an electromagnetic fuel injection valve of a direct-injection internal combustion engine in particular. Particularly, so-called half-lift control in which an active fuel injection is controlled from a state where the valve body of the fuel injection valve is not fully open is catching attention for further reducing the minimum injection quantity while keeping the conventional maximum injection quantity. 
         [0004]    For example, in the technique of PTL 1, the half-lift control is realized by improving the mechanism of the fuel injection valve such that the lift quantity of the valve body can be fixed to two levels of a high lift and a low lift and by setting a driving current of the fuel injection valve for each level. 
         [0005]    In the technique of PTL 2, half-lift control of an electromagnetic fuel injection valve is realized by performing control to supply a valve-opening current for opening the valve body against a fuel pressure upstream of the fuel injection valve for a short period of time to start closing the valve before reaching a state where the valve body is fully open such that the lift quantity of the valve body is in a parabolic motion. 
       CITATION LIST 
     Patent Literature 
       [0006]    PTL 1: JP 2002-266722 A 
         [0007]    PTL 2: JP 2013-2400 A 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0008]    With the technique of PTL 1, it is necessary to improve the mechanism of the fuel injection valve to realize the half-lift control, and the lift quantity in a half-lift region cannot be changed continuously. 
         [0009]    In addition, in the technique described in PTL 2, a specific scheme to continuously changing the lift quantity in the half-lift region in which the fuel injection is finished before the valve body reaches a full-lift state is neither taken into consideration. Further, even if the lift quantity in the half-lift region is variably controlled on the basis of the technique described in PTL 2, a problem that the relationship of a fuel injection quantity with an injection instruction period is different from a full-lift region in which a fuel injection instruction is stopped after the valve body reaches the full-lift position will arise. 
         [0010]    An object of the present invention is made in consideration of such a problem and lies in making flow-rate properties in a half-lift region to be closer to flow-rate properties in a full-lift region to improve the controllability of a minute fuel injection quantity. 
       Solution to Problem 
       [0011]    To solve the problem described above, a control device of the present invention is a control device for electromagnetic fuel injection valve that supplies a driving current to a solenoid to open a valve body with a magnetic force and injects a fuel into an internal combustion engine, and is characterized in that a supply period of the driving current includes a peak current supply period in which a magnetic force necessary for a valve-opening action of the valve body is generated, and 
         [0012]    a lift quantity adjustment period in which a current lower than the peak current is passed for a prescribed period after the peak current supply period. The control device controls, in accordance with a length of the lift quantity adjustment period, at least one of a lift quantity of the valve body, an actual valve-opening period before the valve body reaches a full-lift position, and a fuel injection quantity injected into the internal combustion engine before the valve body reaches the full-lift position. 
       Advantageous Effects of Invention 
       [0013]    According to the present invention, it is possible to make the relationships of a fuel injection quantity with an injection instruction period of a half-lift region and a full-lift region closer to each other, and thus it is possible to improve the controllability of a minute fuel injection quantity. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0014]      FIG. 1  is an illustration of an overall configuration of the present invention. 
           [0015]      FIG. 2  is a diagram illustrating a configuration of a fuel injection valve control device. 
           [0016]      FIG. 3  is an illustration of a conventional method of driving a fuel injection valve. 
           [0017]      FIG. 4  is a chart illustrating a conventional fuel injection quantity property. 
           [0018]      FIG. 5  is an illustration of half-lift control according to conventional control. 
           [0019]      FIG. 6  is an illustration of a method of driving a fuel injection valve according to the present invention. 
           [0020]      FIG. 7  is an illustration of valve behavior of the fuel injection valve according to the present invention. 
           [0021]      FIG. 8  is an example of a timing chart in a half-lift state according to the present invention. 
           [0022]      FIG. 9  is another example of a timing chart in a half-lift state according to the present invention. 
           [0023]      FIG. 10  is an illustration of fuel injection quantity properties according to the present invention. 
           [0024]      FIG. 11  is an illustration of a driving method of a second exemplary embodiment. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0025]    Exemplary embodiments of the present invention will be described below with reference to drawings. 
       First Exemplary Embodiment 
       [0026]      FIG. 1  illustrates an example of a basic configuration of a fuel injection control device. First, a battery voltage  109  supplied from an on-vehicle battery is supplied to a fuel injection valve control device  101 , which is provided in an engine control unit (hereinafter referred to as ECU) that is not illustrated, via a fuse  103  and a relay  104 . 
         [0027]    In the present exemplary embodiment, a normally-closed electromagnetic fuel injection valve will be described as a fuel injection valve  108  controlled by the fuel injection valve control device  101 . The fuel injection valve  108  drives a valve body in an opening direction by supplying a current to a solenoid to generate a magnetic attractive force and closes the valve in accordance with, for example, a spring force or a supplied combustion power by cutting off the current supplied to the solenoid. 
         [0028]    The configuration of the fuel injection valve control device  101  will be described herein. The fuel injection valve control device  101  includes a high voltage generation unit  106  that generates, on the basis of the battery voltage  109 , a high power-source voltage (hereinafter referred to as a high voltage  110 ) required when opening the valve body provided in the fuel injection valve  108 , and the high voltage generation unit  106  boosts the battery voltage  109  to reach a desired target high voltage on the basis of an instruction from a driving IC  105 . The high voltage generation unit may be implemented by, for example, a booster circuit including a coil, a condenser, and a switching element. As described above, the fuel injection valve  108  is provided with two lines of power sources including the high voltage  110  for securing a valve-opening power of the valve body and the battery voltage  109  that causes the valve body to remain open such that the valve body is not closed after being opened. 
         [0029]    In addition, a fuel injection valve driving units  107   a  and  107   b  are provided upstream and downstream of the fuel injection valve  108  and supply a driving current to the fuel injection valve  108 . The details will be described later, and thus the description is omitted herein. 
         [0030]    The high voltage generation unit  106 , the fuel injection valve driving units  107   a  and  107   b  are controlled by the driving IC  105  and apply the high voltage  110  or the battery voltage  109  to the fuel injection valve  108  to achieve a desired driving current. In addition, in the driving IC  105 , choosing the driving period of the fuel injection valve  108  (current-passing time of the fuel injection valve  108 ) and a driving voltage, and a set value of the driving current are controlled on the basis of an instruction value calculated at a fuel injection valve pulse signal calculation block  102   a  and a fuel injection valve drive waveform instruction block  102   b  provided in an in-ECU (not illustrated) block  102 . 
         [0031]    Next, the driving units  107   a  and  107   b  for the fuel injection valve  108  illustrated in  FIG. 1  will be described with reference to  FIG. 2 . As described with reference to  FIG. 1 , the driving unit  107   a  upstream of the fuel injection valve  108  supplies the high voltage  110  from the high voltage generation unit  106  in the drawing to the fuel injection valve  108  via a diode  201  provided for preventing a countercurrent and by using a switching element of TR_Hivboost  203  in the drawing so as to supply a current required for opening the fuel injection valve  108 . Meanwhile, after opening the fuel injection valve  108 , the battery voltage  109  required for keeping an open state of the fuel injection valve  108  is supplied to the fuel injection valve  108  via a diode  202  for preventing a countercurrent and by using a switching element of TR_Hivb  204  in a similar manner to the high voltage  110 . 
         [0032]    Next, the fuel injection valve driving unit  107   b  downstream of the fuel injection valve  108  is provided with a switching element of TR_Low  205 . A power source supplied from the fuel injection valve driving unit  107   a  that is upstream can be applied to the fuel injection valve  108  by turning the driving circuit TR_Low  205  on, and desired current control of the fuel injection valve  108  that will be described later is performed by detecting a current consumed by the fuel injection valve  108  with a shunt resistor  206 . To be noted, the present description shows an example of a method of driving the fuel injection valve  108 , and the battery voltage  109  may be used when opening the fuel injection valve  108  in place of the high voltage  110  in the case where, for example, a fuel pressure is relatively low or the high voltage generation unit  106  has a malfunction. 
         [0033]    Next, current control of the fuel injection valve  108  in a conventional technique will be described with reference to  FIGS. 3 and 4 . Generally, in the case of driving the fuel injection valve  108  of a direct-injection internal combustion engine, a current profile  302  is set beforehand on the basis of properties of the fuel injection valve  108 , and the injection quantity property of the fuel injection valve  108  with the current profile  302  is recorded in an ECU (not illustrated). The fuel injection valve control device  101  calculates driving instruction time (hereinafter a pulse signal  301 ) of the fuel injection valve  108  from an operation state (inhaled air quantity) of an internal combustion engine (not illustrated) and the injection quantity property of the fuel injection valve  108 . 
         [0034]      FIG. 3  illustrates an example of this control method. The pulse signal  301  is turned on at a desired injection timing T 304  calculated in the ECU, and current control of the fuel injection valve  108  is performed on the basis of the driving current profile  302  recorded in the ECU beforehand. 
         [0035]    The driving current profile  302  in the example of  FIG. 3  is constituted by a plurality of target current values including a valve-opening peak current  302   a  for opening the fuel injection valve  108  and a first holding current  302   b  and a second holding current  302   c  for holding the valve-open state. The fuel injection valve control device  101  operates the fuel injection valve  108  by switching between the target current values ( 302   a,    302   b,  and  302   c  in  FIG. 3 ) on the basis of a control sequence set beforehand, and continues to apply a driving current to the fuel injection valve  108  until T 308  at which the pulse signal  301  is turned off. 
         [0036]    Next, valve body behavior of the fuel injection valve  108  will be described. After the pulse signal is turned on (T 304 ), the high voltage is applied to the fuel injection valve  108  until reaching the valve-opening current  302   a.  The valve body starts opening at a time point (T 305  in  FIG. 3 ) when a residual magnetic field based on electric properties unique to the fuel injection valve reaches a prescribed quantity. The valve body continues valve-opening action thereafter as a result of valve-opening force from the valve-opening current (current behavior until reaching  302 A) remaining, and the valve body reaches a stopper position on the valve-opening side (T 306 ). At that time, a surplus opening force causes a boucing motion of the valve body for some time (period of  301 ), and the valve body transitions to a stable valve open state (T 307 ). Thereafter, a state in which the valve body is fully open is kept until a time point (T 308 ) at which the pulse signal is turned off. Thereafter, the residual magnetic field of the fuel injection valve  108  is reduced, and the valve body is completely closed (T 309 ) after going through a valve-closing operation. The state in which the valve body is fully open in this behavior is defined as full lift in the present invention. After time T 307  at which the full-lift and the stable valve open state is reached, the fuel injection quantity is adjusted by controlling the time in which the position of the full lift is kept by the time in which the first holding current  302   b  and the second holding current  302   c  are supplied. 
         [0037]    Next, the injection quantity property in the case of using the driving current  302  illustrated in  FIG. 3  will be described with reference to  FIG. 4 . It has been explained that the fuel injection quantity property is determined from the driving current profile  302  and the period in which the pulse signal  301  is on. In the case where the length of the pulse signal  301  is set as the horizontal axis and the fuel injection quantity per driving time is set as the vertical axis, a property represented by  401  is obtained. 
         [0038]    To describe this in detail, in the section  402  between the time point T 305  at which the valve body starts to open and the time point T 306  at which the valve body reaches the full lift, the fuel injection quantity increases as the lift quantity of the valve body increases on the basis of the supplying time of the valve-opening peak current  302   a.  In this period, since an inclination  401   a  of the fuel injection quantity is determined in accordance with the opening speed of the valve body and the power-source voltage for the peak current is derived from the high voltage  110 , a property in which the inclination of  401   a  increases steeply is given. 
         [0039]    Thereafter, the valve body collides with a stopper, and thus boucing also occurs in the fuel injection quantity property due to the boucing motion  310  that has been already described (period from T 306  to T 307 ). This bouncing period  403  is generally not used because of, for example, large differences in properties between fuel injection valves or poor reproducibility between injection operations. 
         [0040]    Thereafter, the valve body after the bouncing is settled (T 307 ) has an increasing property with an inclination  401   b  proportional to the length of the pulse signal for keeping a full-lift position, and the minimum injection quantity of a conventional fuel injection valve  108  is treated as a fuel injection quantity at the time of full lift  405 +a surplus quantity. 
         [0041]    Next, an example in which half-lift control is performed on the basis of the conventional method of driving the fuel injection valve  108  described with  FIG. 3  will be described with reference to  FIG. 5 . First, the half-lift control of the present invention is defined as performing such an operation that the behavior of the valve body draws a parabola by turning the pulse signal off in the period (period from T 305  to T 306  in  FIG. 3 ) from the time at which the valve body starts to open to the time at which the valve body comes into contact with the stopper. 
         [0042]    In  FIG. 5 , for easier understanding of a timeline scale, the pulse signal  301 , the driving current  302 , and the valve behavior  303  at the time of full lift illustrated in  FIG. 3  are illustrated by broken lines. 
         [0043]    The valve-opening peak current increases after the time point T 304  at which a pulse signal  501  is turned on ( 505 ,  506 , or  507 ). Thereafter, by turning the pulse signal  501  off at a stage (T 502 , T 503 , or T 504 ) before the time point T 306  at which the valve body collides with the stopper, T 502 , T 503 , and T 504  respectively draw loci  505 ,  506 , and  507 , and the driving current becomes 0 A. In the case where the valve-opening action is started at T 306  after the sequence that has been already described and the pulse signal  501  is turned off at T 502 , valve behavior represented by  507  is shown. Similarly,  508  is shown for T 503 , and  509  is shown for T 504 . Since it is before the valve body collides with the stopper, it becomes possible to perform half-lift control on the valve body behavior. Examples of a problem that arises at this time include a problem that the inclination  401   a  at this time becomes a different property from the inclination  401   b  at a full-lift region since the inclination  401   a  is steep. Specifically, the fuel injection quantity property in this case is the period indicated by  402  in  FIG. 4 . If the valve-opening peak current is prolonged over T 503 , the valve body will grow powerfully until reaching a stopper position  510 , and thereafter the boucing motion that has been already described will occur. Therefore, in order to realize the half-lift control illustrated in  FIG. 5 , it is required to perform control to address the steepness of  401   a.  Specifically, it is required to make the gain of correction of the pulse signal  501  represented by a combustion pressure correction to be adaptable equally to the inclination of the conventional control  401   b,  or make modification to control resolution so as not to use the boucing period  403 . 
         [0044]    For example, in the case where a required injection quantity less than the minimum injection quantity that has been already described is calculated in the ECU, a method of not using the period  403  by skipping to the half-lift control period  402  illustrated in  FIG. 5  can be considered. It is needless to say that care needs to be taken for differences of injection quantity that occur in this skipping control and the computation for the skipping control becomes complex. 
         [0045]    To solve these problems, the method of driving the fuel injection valve  108  according to the present invention is shown.  FIG. 6  is a schematic diagram of a case where full-lift control is performed via a driving method according to the present invention. First, a peak current supply period  609  for generating a magnetic force required for valve-opening action of the valve body provided in the fuel injection valve  108  is provided. In this period, a pulse signal  601  is turned on (T 604 ) and a driving current  602  is until either of reaching a valve-opening peak current value  610  and reaching a prescribed period is satisfied and drives the fuel injection valve  108  with the high voltage  110  similarly to the valve-opening peak current illustrated in  FIG. 3 . 
         [0046]    In addition, this peak current supply period  609  needs to be greater than a valve-openability-guaranteeing minimum current value  611 , which enables surely performing valve-opening even under the maximum combustion pressure under which the fuel injection valve  108  is used, or than a period corresponding thereto. That is, this peak current supply period  609  is for generating at least a minimum magnetic force required for performing valve-opening action of the fuel injection valve  108  to guarantee valve-opening of the fuel injection valve. 
         [0047]    After the requirement for completing the peak current supply period is satisfied, a lift quantity adjustment period  603  in which a current lower than the peak current is supplied to the fuel injection valve  108  for a prescribed period is provided. This lift quantity adjustment period  603  applies a low voltage represented by the battery voltage  109  to the fuel injection valve  108 . 
         [0048]    The present invention is characterized by controlling the lift quantity of the valve body in the half-lift state before reaching the full lift in accordance with the length of the lift quantity adjustment period  603 . The details of this point will be described later with reference to  FIG. 7  and drawings assigned with greater numbers. A target current value  612  of the lift quantity adjustment period  603  needs to be equal to or greater than a valve-opening-holdability-guaranteeing minimum current value  613  that allows holding the valve-open state of the fuel injection valve  108 . 
         [0049]    In addition, the present invention is characterized by being provided with a current cutoff period (from T 605  to T 606 ) for quickly reducing the peak current after the peak current supply period  609  and before transitioning to the lift quantity adjustment period  603 . This is for the purpose of counterbalancing an excess valve-opening force (for example, in the case where the combustion pressure is low), which has occurred in the peak current supply period, in the current cutoff period (from T 605  to T 606 ). This once cancels the power of the valve body at the time of valve opening, and thus the controllability of the lift quantity in the half-lift state in the lift quantity adjustment period  603  thereafter is improved. 
         [0050]    To quickly reduce the peak current in the current cutoff period (from T 605  to T 606 ), supply of the high voltage  110  and the battery voltage  109  to the fuel injection valve  108  may be cut off. Further, to quickly reduce the peak current, a negative voltage may be applied to the fuel injection valve  108 . To apply the negative voltage, for example, a counter-electromotive force generated in the solenoid of the fuel injection valve  108  may be used. A current passing through the fuel injection valve  108  can be reduced by providing a path that is connected to a ground and the high voltage generation unit  106  (or an on-vehicle power source) via a commutator and serves as an escape for a countercurrent generated in the fuel injection valve  108  due to the counter-electromotive force when the driving units  107   a  and  107   b  are both turned off. 
         [0051]    Here, completion requirement during the current cutoff period (from T 605  to T 606 ) transitions to the lift quantity adjustment period  603  when either one of a case of being reduced to reach a prescribed current value and a case of a prescribed period having passed is satisfied. When transitioning to the lift quantity adjustment period  603 , control is performed via either of the battery voltage  109  and the high voltage  110  such that a target current value  612  is reached. 
         [0052]    Next, the valve behavior will be described with reference to  FIG. 7  and by the method of driving the fuel injection valve illustrated in  FIG. 6 . Turning on and turning off of a pulse signal  701  is performed at the same timing as in  FIG. 6 . For convenience of description, the valve behavior  303  illustrated in  FIG. 3  is illustrated by a broken line and referred to as valve behavior  702  in  FIG. 6 . 
         [0053]    In the valve-opening action, with the driving method illustrated in  FIG. 3 , the lift quantity increases with a high valve-opening speed as  705  and settles in the full-lift position after going through a boucing period  707 , and with the driving method of the present invention illustrated in  FIG. 6 , behavior represented by  706  is exhibited. This can be achieved mainly by controlling the growth of the valve behavior in the lift quantity adjustment period  603 . Stable valve-opening action, that is, half-lift control of the minimum lift quantity is generated from the peak current or the peak current and the current cutoff period (from T 605  to T 606 ) (the details will be described with reference to  FIG. 8 ), and increase of the lift quantity thereafter is controlled with the length of the lift quantity adjustment period  603 . 
         [0054]    Since the lift quantity adjustment period  603  is controlled by the battery voltage  109  and the speed of the valve speed is moderated, the full-lift position is reached in a soft-landed state  708  without the occurrence of a boucing period  707 . 
         [0055]    Next, the half-lift control of the present invention will be described with reference to  FIGS. 8 to 10 . First, the half-lift control will be described with the minimum lift quantity that has been already described and with reference to  FIG. 8 . It is assumed that a timing T 805  at which a pulse signal  801  in  FIG. 8  is turned off is in the current cutoff period (from T 605  to T 606 ) from the completion requirement of the peak current supply period  609  described with reference to  FIG. 6 . 
         [0056]    For convenience of description, the driving current  602  of  FIG. 6  is illustrated by a broken line, and the valve behavior at that time is illustrated by a broken line  702 . In this scene, since a current is supplied to the fuel injection valve  108  only during the peak current supply period  609 , a case where driving is performed only with the high voltage  110  is indicated. Although a pulse signal  801  is turned off at T 805 , since the current cutoff period (from T 605  to T 606 ) is provided for the driving current  602  illustrated in FIG.  6 , the same locus is also obtained in the case where the pulse signal  801  is turned off in this period. 
         [0057]    Valve behavior  803  at this time may be set so as to be the minimum lift quantity of the half-lift control. This is because the peak current supplied in the peak current supply period  609  is required to be set so as to surpass the valve-openability-guaranteeing minimum current value  611  required when opening the fuel injection valve  108 , a degree in which difference derived from machine difference and pulsation width with respect to a target combustion pressure is considered even for fuel injection valves  108  with the same properties is assumed, and there is a possibility that the valve body does not open in the case where the current is lower than this. Of course, the peak current has a room for these factors to a certain degree. However, in a basic idea, the electric energy constituted by the peak current supply period  609  or by the peak current supply period  609  and the current cutoff period (from T 605  to T 606 ) is the minimum lift quantity having the reproducibility illustrated in  FIG. 8 . 
         [0058]    The description of  FIG. 9  will be made on the basis of this.  FIG. 9  illustrates the driving current and the valve behavior in the case where the pulse signal  601  is turned off in an arbitrary timing after the turning-off timing of the pulse signal  801  of  FIG. 8 . 
         [0059]    A pulse signal  901  of  FIG. 9  is turned on at T 903  and turned off at each timing of T 805 , T 904 , T 905 , T 906 , and T 907 . At this time, the driving current becomes the same locus at T 805  and T 904  as illustrated in  FIG. 8 . This part has been described with reference to  FIG. 8  and is thus omitted. The driving current in the case of turning off the pulse signal at T 905  is referred to as  908 , and those thereafter will be referred to as  909  and  910 , respectively. In addition, the valve behavior in the case of T 805  and T 904  draws a locus represented by a broken line  803 , and in the case of turning off the pulse signal at T 905 , valve behavior  911  is obtained. Those thereafter will be  912  and  913  in this order. In this way, the valve lift quantity grows in accordance with the length of the pulse signal  901  while tracing the valve behavior  702  at the time of full lift described with reference to  FIG. 7 . Further, if the peak current supply period  609  and the current cutoff period (from T 605  to T 606 ) are set so as to be substantially regular periods, the length of the lift quantity adjustment period  603  will be determined in accordance with the length of the pulse signal  901 . In addition, as illustrated in  FIG. 8 , the valve behavior  803  corresponds to the minimum lift quantity of the present invention and the valve lift quantity thereafter is determined on the basis of the length of the lift quantity adjustment period  603 . In other words, an actual valve-opening period or the fuel injection quantity of the fuel injection valve  108  in the half-lift state is controlled on the basis of the length of the lift quantity adjustment period  603 . 
         [0060]    This enables continuously increasing the lift quantity until reaching the full-lift position without the occurrence of boucing while providing a smooth valve-opening action. To see this as a fuel injection quantity property, a property illustrated in  FIG. 10  is obtained. An injection quantity property  1001  is raised from a time point T 1002  at which the valve body starts the valve-opening action until the time point T 605  at which the peak current  610  is reached, and transitions to the current cutoff period (from T 605  to T 606 ). In the current cutoff period from T 605  to T 606 , the driving current  902  does not change whenever the pulse signal  901  is turned off. Therefore, the valve behavior draws the same locus (T 803 ). Therefore, the injection quantity property  1001  becomes a flat property until a time point T 1003  at which the current cutoff period (from T 605  to T 606 ) is completed. Thereafter, a current is supplied from the battery voltage  109  as a result of transitioning to the lift quantity adjustment period  603 , and the injection quantity property starts to rise again. 
         [0061]    As described with the valve behavior of  FIG. 9 , in the present invention, there is no big difference in the inclination of the injection quantity property between a half-lift period  1006  and a full-lift period  1007 . Therefore, the control can be executed without considering the half-lift region and the full-lift region. 
         [0062]    In the present invention, the state described with reference to  FIG. 8  is the minimum injection quantity. Therefore, the injection quantity at T 1003  corresponds to this. 
         [0063]    The present exemplary embodiment shows an example in which the present invention can be effectively used and includes, for example, making the valve-opening action of the valve behavior  706  illustrated in  FIG. 7  to be in an appropriate state by causing the target current value  612  in the lift quantity adjustment period  603  to be variable with a lapse of time. To be noted, the most appropriate state referred to herein indicates causing the inclinations of the injection quantity property  1001  in  1006  and  1007  of  FIG. 10  to match each other to such a degree as not to influence the control, and this indicates optimizing the target current value  612  by, for example, fitting. 
       Second Exemplary Embodiment 
       [0064]    Another exemplary embodiment according to the present invention will be described with reference to  FIG. 11   
         [0065]    In the first exemplary embodiment, the minimum lift quantity has been described with reference to  FIG. 8 , and a means for further improving the effect in this point will be described. 
         [0066]    As has been already described, the stable valve behavior  803  guaranteed by the peak current supply period  609  or by the peak current supply period  609  and the current cutoff period (from T 605  to T 606 ), is not necessarily the same between fuel injection valves  108  with identical specifications. That is, changing the length of the peak current supply period  609  or the peak current value  610  due to machine difference of the fuel injection valve  108 . 
         [0067]    In other words, the valve behavior indicated by  803  in  FIG. 8  is desirably similar between a plurality of fuel injection valves  108  provided in the same internal combustion engine. From the results of examination by the inventors of the present invention, it is confirmed that, if the variety of valve behavior at this time is below a certain quantity, the valve lift quantity according to the length of the peak current supply period  609  also grows within that range. Therefore, the current supplied in the peak current supply period  609  is adjusted such that the lift quantity indicated by  803  in  FIG. 8  falls within a certain range. 
         [0068]    I this case, with a control device including a means capable of directly detecting the valve lift quantity, it is enough as long as at least one of the length of the peak current supply period  609  and the peak current value  610  and one or more of the length of the current cutoff period (from T 605  to T 606 ) and the target current during current cutoff are adjusted. Here, adjustment using the actual valve-opening period  711  correlated with the lift quantity will be described. 
         [0069]    In  FIG. 11 , the driving current indicates, on the basis of  602  in  FIG. 6 , valve behavior ( 803  and  1102 ) of different fuel injection valves  108  at a timing in which a pulse signal  1101  is the same (on from T 1109  to T 1110 ). 
         [0070]    In this case, the actual valve-opening period of  803  is  1104  and the actual valve-opening period of  1102  is  1105 . By using a function to detect these two periods, difference between the two is eventually calculated and corrected to the peak current supply period  609 . Although it is half lift in  FIG. 11 , the effect can be achieved also with a method of detecting the difference between the two at the time of full lift. In addition, in the case where the difference is at the time of full lift, it is corrected to the length of the peak current supply period  609  or the peak current value  610  by dividing the difference by the ratio with the lift quantity in the peak current supply period  609  to detect the difference in a full-lift quantity  1108 . 
         [0071]    In addition, the correction at this time is based on an idea of performing relative correction between fuel injection valves  108  provided in the same internal combustion engine, and, for example, the difference from the other fuel injection valves  108  is calculated by setting the longest actual valve-opening period  711  as the standard, and the correction is performed on the full-lift quantity and the peak current supply period  609  and the peak current  610  that serve as bases. 
         [0072]    The peak current supply period  609  and the peak current  610  that serve as bases serve as bases indicate, for example, the peak current supply period  609  and the peak current  610  described with reference to  FIG. 8  for the fuel injection valve  108  that is the most difficult to open. This enables reducing the variety of the valve lift quantity in  FIG. 8  caused by, for example, machine difference. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           101  fuel injection valve control device 
           106  high voltage generation unit 
           108  fuel injection valve 
           109  battery voltage 
           601  pulse signal 
           602  driving current 
           603  lift quantity adjustment period 
           609  peak current supply period 
           610  peak current value 
           611  valve-openability-guaranteeing minimum current value 
           612  target current value 
           613  valve-opening-holdability-guaranteeing minimum current value