EP0646723B1

EP0646723B1 - Apparatus suitable for use in batteryless vehicle, for reducing and controlling loads such as electrical components upon its start-up

Info

Publication number: EP0646723B1
Application number: EP19940113766
Authority: EP
Inventors: Yuji C/O Kabushiki Kaisha Honda Ono; Yuichi C/O Kabushiki Kaisha Honda Morino
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 1993-10-05
Filing date: 1994-09-02
Publication date: 1997-05-28
Anticipated expiration: 2014-09-02
Also published as: JP3201684B2; JPH07103112A; DE69403420D1; BR9403994A; CN1109554A; EP0646723A1; DE69403420T2; CN1052528C

Description

The present invention relates to an apparatus for reducing and controlling electrical loads such as electrical components upon starting an engine of a batteryless vehicle.
When an engine is started up, the number of revolutions of an input shaft of a generator is low and an output voltage generated from the generator is low. Thus, there is a situation in which power cannot be sufficiently supplied to an igniter. Therefore, a starting apparatus suitable for use in a batteryless vehicle, of a type wherein when the engine is started by either a kick starter or a recoil starter, loads such as a lamp, etc. are electrically disconnected, and the loads such as the lamp, etc. are then connected when an output voltage generated from a generator has risen, thereby making it possible to supply sufficient power to an igniter and smoothly start the engine, has been disclosed in Japanese Utility Model Application Laid-Open No. 4-137264.
However, the conventional starting apparatus for the batteryless vehicle has a problem in that when the output voltage generated from the generator in a state in which the loads such as the lamp, etc. are being disconnected, has reached a predetermined threshold voltage, the load connection is made to thereby increase the electrical load on the generator upon the load connection, with the result that the output voltage is often reduced.
Since the weight or quantity (power to be used up by the connected load) of the connected load varies depending on the states of setting of various switches or the like, the degree of reduction in the output voltage generated upon connecting the load also varies.
Since the generated output is insufficient during an engine start-up period from the ignition to the complete explosion, there is a possibility that when other load is connected during this period, an engine speed is reduced and the power cannot be sufficiently supplied to the igniter.
Further, if consideration is taken in such a manner that power can be supplied to all the loads at idle, it is then necessary to set a threshold voltage for the load connection to a voltage lower than the generated output voltage at full load under the idle state.
FIG. 6 is a graph for describing rise characteristics of voltages output from the generator upon starting up the engine.
A characteristic A indicated by an imaginary line in FIG. 6 shows a characteristic of an output voltage generated at non-load. This characteristic is obtained by measuring the output voltage of the generator with a high input impedance type voltmeter, for example, supplying the same voltage as the measured voltage to an igniter from another power supply and determining the output voltage in a state in which the loads such as the lamp, etc. are all electrically disconnected.
A first crest of a waveform of the output voltage is formed by powerfully rotating an output shaft of the engine under the operation of either the kick starter or the recoil starter.
At a time t1, the igniter starts to supply an igniting high voltage to an ignition or spark plug. At a time t2, the engine is brought into a completely-exploded state and hence runs at idle speed under an idling state. Since, at this time, no load is connected to the generator, the generated output voltage is set as a substantially upper-limit value of a voltage control range by a voltage regulating circuit (regulator) incorporated into (or provided outside) the generator.
A characteristic B indicated by a dot line represents a rise characteristic of an output voltage generated (at full load) in a state in which the igniter and all the loads supplied with the power from the generator have been connected to the generator.
Since the entire load on the generator is heavy, the generated output voltage is reduced and the timing for obtaining each of the ignition and the complete explosion is slightly delayed. However, an output voltage generated in a state in which the engine has been successfully started and the engine speed has reached the idle speed, becomes a voltage (corresponding to a substantially lower-limit value of the voltage control range by the voltage regulating circuit (regulator) though this voltage depends on the electrical generating capacity of the generator) substantially lower than that obtained at the characteristic A (at full non-load).
A characteristic C indicated by a solid line represents a rise characteristic of an output voltage generated at light load in which the load on the generator is set as the igniter alone, for example. Since the load is light, a rise in the generated output is also quick and a generated output voltage higher than that obtained at full load can be obtained under the idle speed.
Now, consider that the voltage lower than the output voltage generated at idle speed under full load is represented as a threshold voltage VTH and the load connection is made when the threshold voltage VTH is reached. The generated output voltage rises at the rise characteristic indicated by symbol B and the load is connected when the generated output voltage has reached the threshold voltage VTH (at a time tTH), so that the load on the generator is made heavy. There is therefore developed a situation in which the generated output voltage rises again after it has been reduced to a voltage less than or equal to the threshold voltage. Further, there is produced a situation in which when the difference between the threshold voltage VTH for starting the supply of the power to the load and the threshold voltage for stopping the supply of the power to the load becomes small or when the hysteresis characteristic is not set, the supply of the power to the load is temporarily stopped and hence the lamp or the like that has lighted up once, is temporarily turned off.
Furthermore, it often happens that since the voltage to be supplied to the igniter is also reduced, a sufficient high voltage is not supplied to the spark plug, thus causing no complete explosion.
There is therefore a demand for an apparatus suitable for use in a batteryless vehicle, for reducing and controlling loads such as electrical components upon its start-up, wherein power generated from a generator is supplied to an igniter in preference to others during an engine start operation and the power is supplied to other load such as a lamp or the like after the engine has reliably been started.
According to the present invention, there is provided an apparatus for reducing and controlling electrical loads such as electrical components upon starting an engine of a batteryless vehicle, the vehicle comprising a generator driven by the engine so as to supply power to the loads based on a rotational output of the engine and to actuate an igniter based on the rotational output, said apparatus comprising switching means provided between an output of the generator and an electrical load other than the igniter and load supply-power controlling means for activating the switching means so as to be brought into a closed state upon starting the engine and for supplying the power generated by the generator to said other load, characterized in that the load supply-power controlling means activate the switching means in response to a signal related to an engine speed detected by engine speed detecting means and bring the switching means into the closed state when the engine speed related signal has reached a predetermined engine speed threshold higher than a maximum peak engine speed at the start of the engine.
When the engine speed detected by the engine speed detecting means has reached the predetermined engine speed higher than a maximum peak engine speed at the start of the engine (e.g., an engine speed slightly lower than an idle speed), the load supply-power controlling means drives the switching means so as to be brought into the closed state to thereby supply the power generated by the generator to other load (e.g., a lamp or the like).
Thus, the other load is electrically disconnected upon starting the engine until the engine speed reaches the predetermined speed. Therefore, since the power generated according to the rotation of the engine is effectively supplied to the igniter, the engine can be reliably started.
To ensure the indicating function of an indicator system even upon starting the vehicle, the apparatus can be constructed as defined in claim 2. The generated power is supplied to the igniter, the indicator system for indicating the state of the vehicle, and the horn or the like as needed. Therefore, the state (the neutral position of the gear, for example) of the vehicle can be displayed so as to be visually observed by the driver.
To make it unnecessary to provide a space for newly mounting an apparatus for reducing and controlling loads such as electrical components upon starting a batteryless vehicle as a space for newly mounting a control circuit or the like in the vehicle is small, and to cause the apparatus to share the use of other already-provided circuit device or form it integrally with the other device, the apparatus can be constructed as defined in claim 3.
The engine speed detecting means is made up of the crank angle sensor which has already been provided for the igniter and the load supply-power controlling means is formed integrally with the igniter. Therefore, the load supply-power controlling means can be realized by sharing the use of either a control circuit for controlling a circuit for waveform-shaping an output detected by the crank angle sensor and an ignition timing or a control microcomputer or the like. As a result, the load supply-power controlling means can be economically materialized. It is also unnecessary to ensure a new mounting space or the like.
Since the capacity discharge type igniter of d.c. power operation-type (DC-CDI) performs and effects the ignition using the power generated from the generator, the or each apparatus according to the present invention, which efficiently makes use of the generated power, becomes more effective.
Preferred embodiments of the present invention will hereinafter be described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an apparatus suitable for use in a batteryless vehicle as defined in claim 1, for reducing loads such as electrical components upon starting the batteryless vehicle.
FIG. 2 is a view for describing a circuit configuration of one specific example of each of a load supply-power controlling means and a switching means.
FIG. 3 is a graph for describing a hysteresis characteristic indicative of the supply of power to other load and the stoppage of its supply.
FIG. 4 is a block diagram illustrating an apparatus suitable for use in a batteryless vehicle as defined in claim 2, for reducing loads such as electrical components upon starting the batteryless vehicle.
FIG. 5 is a block diagram showing an apparatus suitable for use in a batteryless vehicle as defined in each of claims 3 and 4, for reducing loads such as electrical components upon starting the batteryless vehicle.
Fig. 6 is a graph for describing rise characteristics of voltages output from a generator upon starting an engine.
FIG. 1 is a block diagram illustrating an apparatus suitable for use in a batteryless vehicle as defined in claim 1, for reducing loads such as electrical components or equipment upon starting the batteryless vehicle.
The apparatus 1 comprises a generator 3 driven in accordance with a rotational output of an engine 2, an ignition device or igniter 4 and a switching means 7 for controlling the supply of power to other load 6 other than a load supply-power controlling device 5. A capacitor 8 electrically connected between an output terminal 3a on the positive-polarity side of the generator 3 and a ground terminal 3b is used to stabilize a power supply.
The generator 3 is made up of an ac generator body (hereinafter called an "ACG") 11 and a rectifying/regulating unit (regulate rectifier) 12.
The ACG 11 has a rotor (not shown) coupled to an output shaft 2a of the engine 2 and rotatably driven with the rotation of the engine 2, a permanent magnet (not shown) attached to the rotor and stator coils 11a through 11c used for taking out a generated output.
The rectifying/regulating unit (regulate rectifier) 12 has a rectifier circuit 13 comprised of six rectifying devices connected to each other in a three-phase bridge arrangement, for rectifying an a.c. voltage induced in each of the stator coils 11a through 11c, and an output voltage regulating circuit 14 for regulating an output voltage generated between the output terminal 3a and the ground terminal 3b.
Next, the generated voltage output to the output terminal 3a of the generator 3 is supplied to each of the igniter 4 and the load supply-power controlling means 5 and supplied to the other load 6 via the switching means 7.
A magnet 2b is mounted to either the output shaft 2a of the engine 2 or the rotor of the ACG 11 so as to correspond to an angular or rotational position of a crank shaft. A pickup coil 15 for detecting magnetic flux produced from the magnet 2b and generating an induced electromotive voltage therefrom forms a crank angle sensor and a means for detecting an engine speed. A signal 15a output from the pickup coil 15 is supplied to the igniter 4 as a signal related to an ignition timing. Further, the signal 15a is also supplied to the load supply-power controlling means 5 as a signal related to the engine speed.
Incidentally, the present embodiment shows the construction wherein the signal related to either the crank angle or the engine speed is obtained using the electromagnetic coupling. However, the signal related to the angular position of the engine or the rotation thereof may be obtained using the optical coupling between a light-emitting means to a light-receiving means both combined into one.
The igniter 4 sets the ignition timing based on the signal 15a output from the pickup coil 15 and supplies an igniting high voltage 4a to a spark plug 16 with a predetermined timing.
The load supply-power controlling means 5 comprises a waveform shaping circuit 20, a load connection deciding means 30 and a switch driving means 40. Incidentally, reference numeral 5a indicates a power terminal on the positive-polarity side and reference numeral 5b indicates a power terminal on the negative-polarity side (the ground side).
The waveform shaping circuit 20 converts the signal 15a output from the pickup coil 15 into a binary-level signal 20a and outputs it therefrom.
The load connection deciding means 30 generates a load connection command signal 30a therefrom in response to the binary-level signal 20a when it detects that the engine speed has exceeded a predetermined engine speed. Incidentally, a hysteresis characteristic is set to the load connection deciding means 30. After the load connection command signal 30a has been generated by the load connection deciding means 30, the load connection deciding means 30 is activated so as to hold the output indicative of the load connection command signal 30a as it is until the engine speed reaches an engine speed rather lower than the previous engine speed.
Based on the load connection command signal 30a, the switch driving means 40 drives the switching means 7 so as to be brought into a closed state (i.e., a state in which the power is supplied to other load).
The switching means 7 is made up of a relay having a normally-opened type contact (make contact).
The operation of the present embodiment having the above-described construction will be described.
When the engine is started by either an unillustrated kick starter or an unillustrated recoil starter so as to rotatably drive the output shaft 2a, the generator 3 generates a voltage corresponding to the number of revolutions of the output shaft 2a at the output terminal 3a. The generated voltage is supplied to the igniter 4 and the load supply-power controlling means 5. Since a contact 7a of the relay of the switching means 7 is in an opened state, no power is supplied to the other load 6 such as a lamp or the like.
The igniter 4 supplies the igniting high voltage 4a to the spark plug 16 with the predetermined timing, based on the output signal 15a of the pickup coil 15 to thereby ignite the engine.
The load connection deciding means 30 provided within the load supply-power controlling means 5 monitors the engine speed based on the output signal 15a of the pickup coil 15. Further, when the engine speed reaches the predetermined engine speed, e.g., an engine speed slightly lower than an idle speed, the load connection deciding means 30 generates the load connection command signal 30a therefrom and hence the switch driving means 40 energizes an excitation winding 7b of the relay in response to the load connection command signal 30a. As a result, the contact 7a of the relay is brought into a closed state so that the power is supplied to the other load 6.
Since the hysteresis characteristic has been set to the load connection deciding means 30, the other load 6 is coupled to the generator 3 so that the load on the generator 3 becomes heavy. Even when the heavy load is put on the engine 2 correspondingly and the engine speed is temporarily reduced, the generation of the load connection command signal 30a from the load connection deciding means 30 is not stopped.
A characteristic E shown in FIG. 6 represents a rise characteristic of an output voltage generated according to this invention. If the load connection is made under an engine speed approximate to that at a complete explosion, then the characteristic E can supply or provide more power by power corresponding to a region F indicated by hatching as compared with a characteristic D (conventional example).
Incidentally, the characteristics D and E shown in FIG. 6 respectively represent those obtained when all the loads have been connected. When the number of lamps or the like to be lighted is low, the output voltage generated at the idle speed is higher than that obtained by the characteristic B (at full load).
FIG. 2 is a view for describing a circuit configuration of one specific example of a combination of the load supply-power controlling means and the switching means.
The load supply-power controlling means 5 shown in FIG. 2 is constructed by a discrete circuit as an illustrative example.
The waveform shaping circuit 20 comprises an amplifier 21 for amplifying the signal 15a output from the pickup coil 15 and a Schmitt trigger circuit 22 for converting an amplified output into a binary signal level. Since the output voltage varies depending on the number of revolutions of the engine 2, even a signal at a low engine speed can be reliably detected by amplifying the output signal 15a of the pickup coil 15 that uses the electromagnetic coupling.
The load connection deciding means 30 has a monostable multivibrator 31 triggered at either a rising edge or a falling edge of a waveform-shaped output 20a corresponding to an output produced from the Schmitt trigger 22 to thereby generate a pulse having a predetermined time interval therefrom, an integrating circuit 32 for integrating an output pulse 31a produced from the monostable multivibrator 31, a voltage comparator 34 for comparing an integrated output 32a produced from the integrator circuit 32 with each of reference voltages VTH1 and VTH2 supplied from a reference voltage generating circuit 33 and outputting a load connection command signal 30a based on the result of comparison, and a hysteresis circuit 35 for changing a reference voltage VTH based on the load connection command signal 30a and providing a hysteresis characteristic.
The integrating circuit 32 is made up of a time-constant circuit comprised of a charging resistor 32b and a capacitor 32c. Reference numeral 32d indicates a resistor for setting a discharge time constant. Respective diodes designated at reference numerals 32e and 32f are used to switch between a charge time constant and the discharge time constant.
A transistor 35a of the hysteresis circuit 35 is in an off state when no load connection command signal 30a is output from the voltage comparator 34. The sum of voltages applied across series-connected constant-voltage diodes or zener diodes ZD1 and ZD2 is supplied to a reference-voltage input terminal K of the voltage comparator 34. When the load connection command signal 30a is output from the voltage comparator 34, the transistor 35a is brought into an on state so as to short-circuit the zener diode ZD2. Thus, the voltage across the zener diode ZD1 is supplied to the reference-voltage input terminal K of the voltage comparator 34. As a result, the action of switching between a first threshold voltage VTH1 used for generating the load connection command signal 30a and a second threshold voltage VTH2 used for stopping the generation of the load connection command signal 30a is carried out.
Reference numeral 33a indicates a resistor used to supply a bias current to each of the zener diodes ZD1 and ZD2. Reference numeral 35b indicates a base resistor and reference numeral 35c indicates a base-to-emitter resistor.
The present embodiment shows the case where since the amplitude of the output signal corresponding to the waveform-shaped output 20a varies depending on the number of revolutions or speed of the engine 2, the width of the pulse to be output based on the waveform-shaped output 20a is respecified or reset by the monostable multivibrator 31. However, the monostable multivibrator 31 may be provided within the waveform shaping circuit 20 as an alternative to the Schmitt trigger circuit 22.
Further, the output voltage determined depending on the engine speed may be obtained by using a frequency-to-voltage converter (F-V converter) instead of the monostable multivibrator 31 and the integrating circuit 32.
The switch driving means 40 is made up of an NPN transistor 41 which is brought into a conducting state based on the load connection command signal 30a. Reference numeral 42 indicates a base resistor and reference numeral 43 indicates a base-to-emitter resistor.
The switching means 27 comprises a PNP transistor 27a. Reference numerals 27b and 27c respectively indicate a base resistor and a base-to-emitter resistor.
Since the present embodiment is constructed in the above-described manner, the voltage determined depending on the number of revolutions of the engine is output from the integrating circuit 32. Next, the voltage comparator 34 compares the voltage 32a determined according to the engine speed with the first threshold voltage VTH1 (corresponding to the sum of the voltages across the zener diodes ZD1 and ZD2) in a state in which the load connection command signal 30a is not being output from the voltage comparator 34.
Here, the first threshold voltage VTH1 is set to a voltage corresponding to an engine speed lower than an engine speed Nei (e.g., 1200 rpm) at the time that the engine runs at idle and to an engine speed Neon (e.g., 1000 rpm) higher than the maximum peak engine speed Nep (e.g., 800 rpm) at the starting of the engine by either the kick starter or the recoil starter.
When the supply of the power to the other load 6 is initiated, the engine speed is sometimes temporarily reduced when the load is heavy. Further, even when the engine speed is instantly reduced due to a defective condition of the rotation of the engine, the second threshold voltage for cutting off or stopping the output so as to continue the supply of the power to the other load 6 is set to a voltage corresponding to an engine speed Neoff (e.g., 500 rpm) rather lower than the maximum peak engine speed at the starting of the engine.
Thus, when the engine speed Ne reaches the engine speed Neon corresponding to the first threshold voltage as shown in FIG. 3, the switching means is brought into the closed state so that the supply of the power to the other load 6 is started. On the other hand, when the engine speed Ne is reduced to the engine speed Neoff corresponding to the second threshold voltage, the supply of the power to the other load 6 is stopped. Since, however, the engine speed Neoff has been set to an engine speed rather lower than the idle engine speed Nei, the supply of the power to the other load 6 is not immediately stopped when the engine is in normal operation.
FIG. 4 is a block diagram showing an apparatus suitable for use in a batteryless vehicle as defined in claim 2, for reducing and controlling loads such as electrical components upon starting the batteryless vehicle.
The apparatus 51 is constructed in such a manner that power generated from a generator 3 is supplied to an indicator-system load 70 even when an engine is started and the supply of the power to other load 6 through a switching means 7 is stopped upon starting the engine.
In the present embodiment, the indicator-system load 70 includes a high-beam indicator lamp 72 that lights up by a beam changeover switch 71 closed when beams cast by headlights are switched to the high level side, a neutral indicator lamp 74 which is turned on by a neutral switch 73 closed when a gear is shifted to a neutral position, a sidestand storage confirmation lamp 76 that is turned on by a sidestand switch 75 closed when a sidestand is in an accommodated state, an oil-level warning lamp 78 turned on by an oil switch 76 and used to issue a warning that engine oil is insufficient, a horn 80 rumbled by activating a horn switch 79, etc.
Incidentally, the indicator-system load 70 may be provided with a fuel warning lamp (not shown) turned on by an unillustrated fuel level switch, for indicating a state in which the remaining quantity of fuel is low.
Since the power is normally supplied to the indicator-system load 70, a driver can visually observe a display or indication of an indicator system upon starting the engine to confirm whether or not an electric system is in operation.
Since the power to be used up by the indicator-system load 70 is so low, the power supplied to the igniter 4 is little reduced, so that the engine 2 can be smoothly started.
The other load 6 comprises a direction indicator 61 having a plurality of lamps that blink by actuating a winker relay 61b under the switching action of a direction indicator switch 61a, a high-beam headlamp 63 and a low-beam headlamp 64 which are selectively turned on by a high/low beam changeover switch 62, a taillamp 65, and loads 69 such as various lamps, a buzzer, etc.
FIG. 4 illustrates one example of the indicator-system load 70 and the other load 6. Various loads should be suitably selected according to vehicle equipment and functions.
The various loads are represented by symbols indicative of lamps in FIG. 4 but may be other electrical loads such as a light-emitting diode, etc. according to purposes.
FIG. 5 is a block diagram showing an apparatus suitable for use in a batteryless vehicle as defined in each of claims 3 and 4, for reducing and controlling loads such as electrical components upon starting the batteryless vehicle.
The apparatus 81 is constructed in such a manner that a load supply-power controlling means 83 is integrally formed within an ignition device or igniter 82. The igniter 82 is made up of a DC-CDI (capacity discharge type igniter of d.c. power operation-type).
The igniter 82 comprises a dc-ac converter (DC-AC converter) 84 for receiving a voltage generated from a generator 3 to be supplied to a power terminal 82a on the positive-polarity side as a power input and generating dual ac outputs therefrom, a rectifying and smoothing circuit 85 for rectifying one of the ac outputs with a rectifying device 85a and smoothing the rectified one with a smoothing capacitor 85b, a constant-voltage circuit 86 for receiving a smoothed output as an input and supplying a stable power voltage, a one-chip microcomputer (hereinafter called a "CPU") 87 activated in response to the voltage supplied from the constant-voltage circuit 86, a waveform shaping circuit 88 for shaping the waveform of an output 15a detected by a pick-up coil 15 and supplying a waveform-shaped output 88a to the CPU 87, a thyristor (SCR) 90 triggered based on an ignition command signal 89a generated from an ignition timing controlling means 89 of the CPU 87, a capacitor 91 for storing discharging energy therein, etc.
One end of a primary winding 92a of an igniting high-voltage generating transformer 92 is electrically connected to an ignition output terminal 82b. An ignition or spark plug 16 is connected to one end of a secondary winding 92b. The other ends of the primary winding 92a, the secondary winding 92b and the spark plug 16 are respectively grounded.
Reference numeral 82c indicates a power terminal on the negative-polarity side.
The DC-AC converter 84 has a self-exicited oscillator circuit 84a, an NPN-type switching transistor 84b and a power-transducing transformer 84c. Reference numeral 84d indicates a base resistor and reference numeral 84e indicates a base-to-emitter resistor.
The switching transistor 84b is switched in response to the output of the self-excited oscillator circuit 84a to interrupt a current which flows in a primary winding 84f of the power-transducing transformer 84c at intervals. Therefore, ac voltages corresponding to the ratio of the primary winding to an igniting winding 84g on the secondary side and the ratio of the primary winding to a power winding 84h on the secondary side are produced in their corresponding igniting winding 84g and power winding 84h.
The ac voltage developed in the power winding 84h is supplied to the CPU 87 through the rectifying and smoothing circuit 85 and the constant-voltage circuit 86.
The ac voltage developed in the igniting winding 84g is rectified by a rectifying diode 93 and the rectified voltage is stored in the capacitor 91.
When the ignition command signal 89a is output, a voltage divided by a current limiting resistor 94 and a gate ground resistor 95 is applied to the gate of the thyristor 90, which is in turn brought into a conducting state, so that the electric charge stored in the capacitor 91 is rapidly discharged. Since the capacitor 91 is connected in series with the primary winding 92a of the igniting high-voltage generating transformer 92, a high voltage is produced in the secondary winding 92b by a pulse current obtained upon the above rapid discharge, so that ignition is made by a spark plug 16.
The output 15a detected by the pickup coil 15, which forms a crank angle sensor, is supplied to the ignition timing controlling means 89 and the load supply-power controlling means 83 through a signal input terminal 82e and the waveform shaping circuit 88.
The ignition timing controlling means 89 is constructed in such a way as to output the ignition command signal 89a in accordance with a predetermined timing, based on an ignition control program stored in advance. Therefore, the ignition command signal 89a is generated depending on the rotation of an engine 2 with the predetermined timing so that the engine 2 is fired up.
Since the waveform-shaped output 88a is produced depending on the rotation of the engine 2, a generating cycle of the waveform-shaped output 88a is inversely proportional to the number of revolutions or speed of the engine 2.
Based on a prestored load connection decision program, the load supply-power controlling means 83 counts a time interval required for a predetermined number of preset waveform-shaped outputs 88a to appear. Further, the load supply-power controlling means 83 calculates either an average period or an average engine speed from the result of counting. When either the calculated average period or the calculated average engine speed exceeds a predetermined threshold related to a load connection, the load supply-power controlling means 83 outputs a load connection command signal 83a therefrom. After the load connection command signal 83a has been output from the load supply-power controlling means 83, the load supply-power controlling means 83 monitors whether either the average period or the average engine speed is less than or equal to a predetermined threshold related to a load nonconnection. If either the average period or the average engine speed is found less than or equal to the predetermined threshold related to the load nonconnection, then the output of the load connection command signal 83a from the load supply-power controlling means 83 is stopped.
Incidentally, the respective threshold values are set so as to meet the relationship shown in FIG. 3.
A decision as to both the load connection and the load disconnection may be made based on the counted time interval without calculating either the average period or the average engine speed.
Further, the decision as to the load connection may be made based on either a period (an instantaneous value) between two adjacent waveform-shaped outputs 88a without being based on the average value or based on an average value (short-time average value) obtained during a relatively short time so as to make the timing for the load connection as soon as possible. Furthermore, the decision as to the load disconnection may be made based on an average value (long-time average) obtained during a time longer than that taken at the time of the decision as to the load connection so as to avoid the frequent stoppage of the supply of power to the load due to an instantaneous reduction in the engine speed.
When the load connection command signal 83a is output, an NPN transistor 88a provided within a switch driving means 88 is made conductive so that an excitation winding 7b of a relay forming a switching means 7 is energized, with the result that a contact 7a thereof is closed so as to supply the power to other load 6.
Reference numerals 88b and 88c designated in the switch driving circuit 88 indicate a base resistor and a base-to-emitter resistor respectively.
Thus, since the DC-CDI 82 has control circuits such as the waveform shaping circuit 88, the CPU 87, etc. and the power supplying means 84, 85 and 86 used for these circuits, the pickup coil 15 forming the crank angle sensor can be used as an engine speed sensor and the load supply-power controlling means 83 can be constructed by adding a deciding means made as to whether the number of revolutions used for the load connection is reached, to a control circuit unit made up of the CPU 87.
Accordingly, a large number of parts in the circuits can be commonly used by forming the load supply-power controlling means 83 integrally with the DC-CDI 82. Further, there is a merit that it is unnecessary to ensure a new mounting space.
When the speed of the engine 2 reaches the predetermined speed, each of the apparatuses 1, 51 and 81 according to the present invention provides an electrical connection to the other load 6. Therefore, the range of variation in the generated voltage at the time that the other load 6 is connected can be made smaller by setting, as the threshold, such an engine speed that the maximum generated power of the ACG 11 is commensurate with the power to be used up by the other load 6 or a reduction in the generated voltage falls within a predetermined range even when the other load is connected.
Further, when it is desired to set the voltage actually supplied to the load upon connecting the load to greater than the minimum operating voltage (VL) for each of various loads, an engine speed (NeVL) capable of obtaining the minimum operating voltage (VL) inclusive of an output voltage regulating operation of the rectifying/regulating unit (regulate rectifier) 12 of the generator 3, may be set as a threshold used for the load connection in a state (under full load) in which the load corresponding to the electrical equipment is the heaviest.
When it is desired to ensure the minimum operation ensuring voltage (VM) for each of the igniters 4 and 82 though there is no harm in reducing the voltage supplied to the load, an engine speed (NeVM) capable of providing the minimum operation ensuring voltage (VM) inclusive of the output voltage regulating operation of the rectifying/regulating unit (regulate rectifier) 12 of the generator 3 may be set as the threshold used for the load connection in the state (under full load) in which the load corresponding to the electrical equipment is the heaviest. In this case, it is desirable that the load connection is made when a state in which the engine speed exceeds the threshold continues for a predetermined time and the load connection is prevented from being made due to a temporary rise in the engine speed. Thus, when the engine speed that allows the load connection is set to a tolerable low value, the difference between the threshold related to the load disconnection and the threshold related to the load connection may be made small. Alternatively, the hysteresis characteristic is not provided to the load connection deciding means. Accordingly, when a state in which the engine speed is less than or equal to the threshold continues for a time set so as to be shorter than a load on-connection monitoring time, the load disconnection may be made.

Claims

An apparatus for reducing and controlling electrical loads (6) such as electrical components upon starting an engine (2) of a batteryless vehicle, the vehicle comprising a generator (3) driven by the engine (2) so as to supply power to the loads (6) based on a rotational output of the engine (2) and to actuate an igniter (4; 82) based on the rotational output, said apparatus comprising:
- switching means (7, 27) provided between an output of the generator (3) and an electrical load (6) other than the igniter (4; 82); and

- load supply-power controlling means (5; 83) for activating the switching means (7; 27) so as to be brought into a closed state upon starting the engine (2) and for supplying the power generated by the generator (3) to said other load (6),
characterized in that the load supply-power controlling means (5; 83) activate the switching means (7; 27) in response to a signal related to an engine speed detected by engine speed detecting means (15) and bring the switching means (7; 27) into the closed state when the engine speed related signal has reached a predetermined engine speed threshold higher than a maximum peak engine speed at the start of the engine.
The apparatus according to claim 1, wherein the power generated by the generator (3) is always supplied to an indicator system (70) for indicating a state of the batteryless vehicle.
The apparatus according to claim 1, wherein said engine speed detecting means (15) comprises a crank angle sensor provided to detect an ignition timing of the igniter (82) and said load supply-power controlling means (83) is formed integrally with the igniter (82).
The apparatus according to claim 3, wherein said igniter (82) is a capacity discharge type igniter of d.c. power operation-type.