Abstract:
An engine starting apparatus with an antitheft function enables rapid and secure starting of a kick-started engine. The engine starting apparatus includes an immobilizer CPU and an ignition CPU, which cooperate to enable authorized engine startup and to prevent unauthorized access. The immobilizer CPU outputs a permission signal if an authentication code from the outside corresponds to a reference code in a vehicle, but outputs an inhibition signal if the authentication code and the reference code fail to correspond. When a starting pedal is kicked, the ignition CPU begins to energize the engine&#39;s ignition system, in response to a predetermined engine starting instruction, before the input reference code is verified. If proper authentication is verified by the permission signal, the ignition CPU continues to allow normal engine starting procedure. If the inhibition signal is received from the immobilizer CPU, the ignition CPU interrupts the normal procedure and inhibits engine starting.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present invention claims priority under 35 USC 119 based on Japanese Patent Application No. 2003-419792, filed Dec. 17, 2003. The entire subject matter of the priority document is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to an engine starting apparatus with an antitheft function. More particularly, the present invention relates to an engine starting apparatus, with an antitheft function, suitable for use with a motorcycle which includes a kick-starting mechanism.  
         [0003]     Some engine startup devices including anti-theft features are known. An immobilizer of the transponder type, which utilizes an authentication code, is known for use as a vehicle antitheft apparatus, such as that disclosed in Japanese Laid-Open Patent No. 2000-329041. The immobilizer described in this reference is used as a substitute security device in place of a conventional lock apparatus of the mechanical locking type, such as a handlebar lock apparatus and a wheel lock apparatus.  
         [0004]     In an immobilizer of the type described in the reference, an authentication code, registered in advance in an ignition key or a portable terminal module, is transmitted toward an authentication apparatus attached to the vehicle body side. If the authentication code coincides, or has a predetermined relationship with an authentication code registered in advance in the authentication apparatus, then starting of an engine is enabled. However, if they do not coincide with each other, or do not have the predetermined relationship, then starting of the engine is prevented.  
         [0005]     In the apparatus disclosed in Japanese Laid-Open Patent No. 2000-329041, the authentication apparatus receives power from a power supply carried on the vehicle body. Accordingly, if sufficient power is not supplied to the authentication apparatus, because of a drop of a battery voltage or the like, then verification of the authentication codes cannot be performed. Particularly with a motorcycle, since a battery carried thereon often has a comparatively small capacity, a drop of the battery voltage must be considered.  
         [0006]     A technique is disclosed in Japanese Laid-Open Patent No. 2002-370621 to make it possible to authenticate an authentication code, even in a condition where the battery voltage is low. This technique divides an authentication procedure of a code in a motorcycle which includes a kick-starting mechanism into three stages, and advances the authentication procedure by one stage by one kick operation. Accordingly, starting of the engine is allowed after three kick operations.  
         [0007]     According to Japanese Laid-Open Patent No. 2002-370621, mentioned above, starting of the engine is permitted only after the validity of an authentication code is confirmed. Thus, even if a generator is driven by a kick-starting mechanism, and driving power is obtained thereby, the power obtained by the first kick is all consumed in the authentication procedure of the authentication code. Consequently, the engine cannot be started by the first kick, but at least three kick operations are required before the engine is started.  
         [0008]     Although the known devices have some utility for their intended purposes, a need still exists in the art for an improved authenticating apparatus for a motorcycle. In particular, there is a need for an improved authenticating apparatus which ensures security, yet which enables a user to start an engine in a shorter period of time than the previously known technology.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention provides an engine starting apparatus with an antitheft function, which improves over the known technology described above, and which can start an engine in a short period of time when the engine is started by a kick.  
         [0010]     An engine starting apparatus with an antitheft function according to a first embodiment of the present invention compares an authentication code, fed in from the outside, with a reference code registered in advance in a vehicle, and starting of an engine is permitted or inhibited depending upon whether or not the two codes correspond according to a relationship set in advance. The engine starting apparatus of the first embodiment hereof is characterized in that the following measures are taken.  
         [0011]     (1) The engine starting apparatus with an antitheft function according to the first embodiment hereof includes a permission signal generator for outputting a permission signal if the authentication code and the reference code correspond, but outputting an inhibition signal if the authentication code and the reference code have any other relationship as an authentication result. The engine starting apparatus also includes starting control mechanism for beginning starting control in response to a predetermined engine starting instruction before the authentication result is sent out; and that the starting control mechanism continues the starting control in response to the permission signal but stops the starting control in response to the inhibition signal.  
         [0012]     (2) The engine starting apparatus with an antitheft function is characterized in that the engine starting apparatus further includes: a regulator for regulating a driving voltage obtained by kick starting and outputting the regulated driving voltage to a power supply line; a first feed line for supplying the driving voltage from the power supply line to the authentication mechanism; and a second feed line for supplying the driving voltage from the power supply line to the starting control mechanism through first switch; that the authentication mechanism starts the authentication when the driving voltage exceeds a predetermined value; and that the starting control mechanism begins the starting control when the first switch is on and the driving voltage exceeds the predetermined value.  
         [0013]     (3) The engine starting apparatus with an antitheft function is characterized in that it further includes: an electric load to which the driving voltage is supplied from the power supply line through second switch; and that the second switch is controlled to an off state for a period of time before the engine exhibits full combustion after the starting control is begun.  
         [0014]     (4) The engine starting apparatus with an antitheft function is characterized in that the starting control mechanism permits or inhibits operation of an ignition system in response to the authentication result.  
         [0015]     According to the described embodiment of the present invention, the following effects are achieved.  
         [0016]     (1) According to a first aspect of the invention, starting of the engine is permitted before the validity of the authentication code is confirmed. Thereafter, the starting control is continued until after the validity of the authentication code is denied. The starting of the engine is inhibited only after the validity is denied. Therefore, where the starting operation is performed using the normal authentication code, the starting of the engine can be performed in a short period of time.  
         [0017]     (2) According to a second aspect of the invention, since the driving voltage obtained by the first kick starting is supplied to the starting control mechanism, starting of the engine can be begun with the kick starting.  
         [0018]     (3) According to a third aspect of the invention, since supply of power to the electric load before the engine exhibits a full combustion and the power obtained by the kick starting can be used all for the starting of the engine, the engine can be started with low power.  
         [0019]     (4) According to another aspect of the invention, since operation of the ignition system is inhibited and the starting of the engine is limited thereby, when the validity of the authentication code is denied, the starting of the engine can be prevented with certainty.  
         [0020]     For a more complete understanding of the present invention, the reader is referred to the following detailed description section, which should be read in conjunction with the accompanying drawings. Throughout the following detailed description and in the drawings, like numbers refer to like parts. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]      FIG. 1  is a side elevational view of an appearance of a scooter type motorcycle to which an engine starting apparatus with an antitheft function according to the present invention is applied.  
         [0022]      FIG. 2  is a block diagram showing a configuration of a major portion of the engine starting apparatus with an antitheft function according to the present invention.  
         [0023]      FIG. 3  is a flow chart illustrating a procedure of “immobilizer control” executed by an immobilizer CPU.  
         [0024]      FIG. 4  is a flow chart illustrating a procedure of indicator control.  
         [0025]      FIG. 5  is a flow chart illustrating a procedure of “starting control” executed by an ignition CPU.  
         [0026]      FIG. 6  is a timing chart (ignition permission) illustrating operation of the present embodiment.  
         [0027]      FIG. 7  is a timing charge (ignition inhibition) illustrating operation of the present embodiment. 
     
    
     DETAILED DESCRIPTION  
       [0028]     It should be understood that only structures considered necessary for clarifying the present invention are described herein. Other conventional structures, and those of ancillary and auxiliary components of the system, are assumed to be known and understood by those skilled in the art.  
         [0029]     In the following discussion, an illustrative embodiment of the present invention is described in detail with reference to the drawings.  FIG. 1  is a side elevational view of a scooter-type motorcycle, to which an engine starting apparatus with an antitheft function according to a first embodiment of the present invention is applied.  
         [0030]     The motorcycle includes a vehicle body front portion  1  and a vehicle body rear portion  2 , connected to each other through a low floor portion  3 . The remaining skeleton of the motorcycle, other than the parts already mentioned, is formed as a vehicle body frame including a down tube and a main pipe.  
         [0031]     The vehicle body front portion  1 , vehicle body rear portion  2  and floor portion  3  are covered with a front cover  4 , a body cover  5  and a center cover  6 , respectively. On the vehicle body front portion  1 , a handlebar  7  is supported for rotation on a steering head, and provided at an upper location, while a front fork  8  is supported for rotation on and extends downwardly from the steering head. A front wheel  9 F is supported for rotation at a lower end of the front fork  8 .  
         [0032]     A swing unit  20  is connected and supported for rocking motion to and at a lower end of a rising portion of the main pipe through a link member  18 . A four single-cylinder four-cycle engine  13  is carried at a front portion of the swing unit  20 . A kick pedal  19  for starting the engine when the battery voltage is low is connected to a crankshaft of the engine  13 . A belt type continuously variable transmission  21  extends rearwardly from the engine  13 , and a rear wheel  9 R is supported for rotation on a reduction gear  14  provided at a rear portion of the continuously variable transmission  21  through a centrifugal clutch. A rear suspension  15  is interposed between an upper end of the reduction gear  14  and the main pipe.  
         [0033]     An upper portion of the handlebar  7  is covered with a handlebar cover  10 , which also serves as an instrument panel. The steering head, front fork  8  and handlebar  7  form a steering mechanism. Grip portions of the handlebar  7  project leftwardly and rightwardly of the vehicle body from the handlebar cover  10 , and a side mirror  11 L ( 11 R) projects upwardly from the handlebar cover  10 . A handlebar lock module  12  is operable to lock the handlebar  7 , in order to disable steering.  
         [0034]     A seat  16  is provided above the body cover  5 , in such a manner as to cover an accommodation box. The seat  16  can be opened and closed, and a helmet or the like can be accommodated in the accommodation box, below the seat  16 . A number plate attaching portion  1   7 , a luggage, a tail lamp and so forth are provided at a rear portion of the body cover  5 . Although an intake pipe, a carburetor, an air cleaner and so forth are disposed incidentally to the engine, they are not shown in the drawings.  
         [0035]      FIG. 2  is a simplified schematic block diagram showing major portions of the engine starting apparatus with an antitheft function according to the selected embodiment of the present invention. Like reference characters to those described above denote like or equivalent elements.  
         [0036]     An ignition key  30  has a memory  31  built therein, in which an identification code [ID] is stored in advance, along with a transmitter  32  for transmitting the identification code. The transmitter  32  of the ignition key  30  and a key cylinder  33  are coupled to each other, for example, by an induction coil (antenna)  34 .  
         [0037]     When the ignition key  30  is inserted in the key cylinder  33 , power is supplied to the transmitter  32  from a receiver  42  through the induction coil  34 . In response to this, the transmitter  32  reads the authentication code from the memory  31 , and transmits it to the key cylinder  33  side. The authentication code is received by a reception section  42   a  of the receiver  42 , and is then demodulated into a digital code by a demodulation section  42   b,  and conveyed to an immobilizer CPU  43 .  
         [0038]     The immobilizer CPU  43  includes a storage section  43   a  for storing a reference code [IDref] unique to each vehicle and a correlation comparison section  43   b  for comparing the identification code [ID] conveyed thereto and the reference code [IDref] to each other.  
         [0039]     An indicator lamp  49  is connected in series to a power supply line to the immobilizer CPU  43 . The correlation comparison section  43   b  outputs a permission signal when it is determined that the identification code [ID] and the reference code [IDref] coincide with each other, or have a relationship determined in advance. However, the correlation comparison section  43   b  outputs an inhibition signal when they do not coincide with each other or do not have the relationship determined in advance as an authentication result signal (S 1 , S 2 ) to an ignition CPU  44 .  
         [0040]     When driving power is supplied from an ignition switch  40 , the ignition CPU  44  begins supplying power to enable starting of the engine. Then, the ignition CPU  44  detects an ignition timing based on a pulser signal detected by a pulser unit  41 , and energizes an ignition unit  45  every time an ignition timing occurs. After the engine is started, the ignition CPU  44  energizes a headlamp relay  46  to cause the headlamp  47  to emit light. An engine stopping switch  48  is connected in series to a power supply line to the ignition CPU  44 .  
         [0041]     An ACG (alternating current generator-motor) starter  50  is connected to the crankshaft of the engine, and also to the kick pedal  19 . A regulator  51  limits an output voltage of the ACG starter  50  to a predetermined voltage, and outputs the predetermined voltage to be supplied to the control units  43 ,  44  mentioned hereinabove, and also to a battery  52  and a further DC load  53 .  
         [0042]     Now, operation of the depicted embodiment is described in detail with reference to flow charts.  FIG. 3  is a flow chart illustrating a procedure of immobilizer control executed by the immobilizer CPU  43 .  
         [0043]     At step S 10 , an initialization process is executed, which is unique to the immobilizer CPU  43 . At step S 11 , flickering of the indicator lamp  49  is started.  
         [0044]     At step S 12 , an authentication result signal is sent out to the ignition CPU  44 . In the present embodiment, the authentication result signal is formed from a pair of authentication result signals S 1  and S 2 , that is, 2 bits. It is defined that a combination (H, L) of the “H” level of the signal S 1  and the “L” level of the signal S 2  represents “permission”. Another combination (L, H) of the “L” level of the signal S 1  and the “H” level of the signal S 2  represents “inhibition”. In the example shown at step S 12  in  FIG. 3 , the combination of (S 1 =H, S 2 =L) corresponding to the “permission” is sent out.  
         [0045]     Information communication between the immobilizer CPU  43  and the ignition CPU  44  is performed using multi bits in this manner. Thereby, information communication between the ignition CPU  44  and the immobilizer CPU  43  can be performed with a higher degree of accuracy.  
         [0046]     At step S 13 , an identification code [ID] received from the ignition key  30  and demodulated by the receiver  42  is fed in. At step S 14 , the reference code [IDref] stored in the storage section  43   a  is read out. At step S 15 , the identification code [ID] fed in and the reference code [IDref] are compared and correlated with each other by the correlation comparison section  43   b.    
         [0047]     At step S 16 , a result of the comparison is evaluated. If the identification code [ID] and the reference code [IDref] coincide with each other, or have the relationship determined in advance, then the processing advances to step S 17 . At step S 17 , it is determined whether or not the ignition switch  40  is on. If the ignition switch  40  is on, then the processing advances to step S 18 . At step S 18 , an authentication result signal (permission) wherein the signal SI has the “H” level and the signal S 2  has the “L” level is sent out.  
         [0048]     On the other hand, if, at step S 16  described above, the identification code [ID] and the reference code [IDref] do not coincide with each other or do not have the relationship determined in advance, then the processing advances to step S 19 . At step S 19 , it is determined whether or not the ignition switch  40  is on. If the ignition switch  40  is on, then the processing advances to step S 20 . At step S 20 , which an authentication result signal (inhibition) wherein the signal S 1  has the “L” level and the signal S 2  has the “H” level is sent out. It is to be noted that, if it is determined at one of steps S 17  and S 19  that the ignition switch  40  is off, then the processing advances to step S 21 . At step S 21 , indicator control for controlling the indicator lamp  49  is executed.  
         [0049]      FIG. 4  is a flow chart illustrating a procedure for the indicator control. At step S 31 , a 24-hour timer T 1  is started. At step S 32 , an authentication result signal (inhibition) wherein the signal S 1  has the “L” level and the signal S 2  has the “H” level is sent out. At step S 33 , the procedure enters a power save mode. At step S 34 , the indicator lamp  49  starts flickering. At step S 35 , it is determined whether or not the ignition switch  40  remains off.  
         [0050]     If the ignition switch  40  remains off, then the processing advances to step S 36 . At step S 36 , it is determined whether or not the timer T 1  exhibits a time-out state. If the timer T 1  exhibits a time-out state, that is, if 24 hours elapse after the ignition switch  40  is switched off, then the indicator lamp  49  is turned off at step S 37  to suppress the power consumption of the battery  52 . On the other hand, if it is detected at step S 35  that the ignition switch  40  is turned on, then the processing advances to step S 38 . At step S 38 , the mode changes from the power save mode back to a normal mode.  
         [0051]      FIG. 5  is a flow chart illustrating a procedure of the “starting control” executed by the ignition CPU  44 . At step S 51 , an initialization process is executed, which is unique to the ignition CPU  44 . At step S 52 , energization of the headlamp relay  46  is inhibited to turn off the headlamp  47 . At step S 53 , a timer T 2  starts. At steps S 54  and S 55 , the authentication result signals S 1  and S 2  are referred to. If the authentication result signals S 1  and S 2  exhibit the “permission” condition wherein the signal S 1  has the “H” level and the signal S 2  has the “L” level, then the processing advances to step S 56 . At step S 56 , an ignition permission flag is set. On the other hand, if the authentication result signals S 1  and S 2  exhibit the “inhibition” condition, then the processing advances to step S 57 . At step S 57 , an ignition inhibition flag is set.  
         [0052]     At step S 58 , it is determined based on an engine speed and so forth whether or not the engine is in a full combustion condition. If the engine is in a full combustion condition, then the processing advances to step S 59 . At step S 59 , it is determined whether or not the timer T 2  is in a time-out condition. In the present embodiment, the timer T 2  is set in advance such that it exhibits a time-out state at 200 ms. If the timer T 2  is in a time-out condition, then the processing advances to step S 60 . At step S 60 , energization of the headlamp relay  46  is started to turn on the headlamp.  
         [0053]     At step S 61 , ignition control is executed. If the ignition permission flag is in a set state, then the ignition unit  45  is energized at every ignition timing determined based on the pulser signal. If the ignition inhibition flag is in a set state, then the ignition is inhibited irrespective of any ignition timing.  
         [0054]      FIGS. 6 and 7  are timing charts illustrating the operation of the present embodiment described above. In particular,  FIG. 6  illustrates the operation when the identification code [ID] and the reference code [IDref] coincide with each other.  FIG. 7  illustrates the operation when the identification code [ID] and the reference code [IDref] do not coincide with each other.  
         [0055]     Referring to  FIG. 6 , the ignition key  30  is inserted into the key cylinder  33  and turned to switch on the ignition switch  40  at time t 1 . Thereafter, the kick pedal  19  is kicked. The output voltage of the regulator  51  reaches a driving voltage for the CPUs  43  and  44  at time t 2 . Then, the immobilizer CPU  43  starts the “immobilizer control” ( FIG. 3 ) and the ignition CPU  44  starts the “starting control” ( FIG. 5 ).  
         [0056]     After the “immobilizer control” ( FIG. 3 ) is started, an authentication result signal (permission) is sent out at step S 12 . Thus, the level of the signal S 1  changes to the “H” level and the level of the signal S 2  changes to the “L” level. In the “starting control” ( FIG. 5 ), the authentication result signal (permission) is detected at steps S 54  and S 55 , and the processing advances to step S 56 . At step S 56 , the ignition permission flag is set. Since it is determined at step S 58  that the engine is not in a full combustion condition as yet, the processing advances to step S 61 . At step S 61 , the ignition control is started. When an ignition timing comes at time t 3 , the ignition unit  45  is energized because the ignition permission flag is in a set state.  
         [0057]     Returning to the “immobilizer control” ( FIG. 3 ), at step S 15 , an identification code [ID] received from the ignition key  30  and the reference code [IDref] are compared with each other. If it is confirmed at step S 16  that they coincide with each other or have the relationship determined in advance, then the processing advances to step S 18 , at which an authentication result signal (permission) is sent out. Accordingly, the ignition CPU  44  can continue to cause the ignition unit  45  to be energized every time an ignition timing comes at step S 61  of the “starting control” ( FIG. 5 ).  
         [0058]     Thereafter, the engine exhibits a full combustion condition at time t 5 , and this is detected at step S 58 . Then, if it is detected at step S 59  that the timer T 2  exhibits a time-out condition, then the headlamp  47  is turned on at step S 60 .  
         [0059]     On the other hand, suppose that it is determined at step S 16  in the “immobilizer control” of  FIG. 3  that the identification code [ID] and the reference code [IDref] do not coincide with each other and an authentication result signal (inhibition) is sent out at step S 20 . Then, the processing of the ignition CPU  44  advances from step S 54  or S 55  to step S 57 . At step S 57 , the ignition inhibition flag is set at time t 4 . Accordingly, since the ignition unit  45  is not energized thereafter by the ignition control at step S 61  even if an ignition timing comes, starting of the engine is blocked.  
         [0060]     It is to be noted that, it is described in the description of the embodiment above that starting of the engine is controlled by permitting or inhibiting operation of the ignition unit  45  in response to the authentication result signals S 1  and S 2 . However, the present invention is not limited to this. In particular, starting of the engine may be controlled otherwise by permitting or inhibiting operation of an injector or a fuel pump.  
         [0061]     Further, in the present embodiment, the ID authentication by the immobilizer CPU  43  and the engine starting determination are performed before the crankshaft of the engine  13  is rotated twice after a point of time of generation by the kick pedal  19 . The ID authentication and the engine starting permission determination are performed in a short period of time while the crankshaft makes two rotations in this manner. Therefore, even if the ID authentication results in failure, the driver can be prevented from realizing starting of the engine before the ID authentication.  
         [0062]     Although the present invention has been described herein with respect to a number of specific illustrative embodiments, the foregoing description is intended to illustrate, rather than to limit the invention. Those skilled in the art will realize that many modifications of the preferred embodiment could be made which would be operable. All such modifications, which are within the scope of the claims, are intended to be within the scope and spirit of the present invention.