WO2002027181A1

WO2002027181A1 - Engine starter

Info

Publication number: WO2002027181A1
Application number: PCT/JP2001/008518
Authority: WO
Inventors: Mitsunori Inaba; Kimio Yukimori; Yoshihiro Kaneko; Yutaka Nozue
Original assignee: Mitsuba Corporation
Priority date: 2000-09-28
Filing date: 2001-09-28
Publication date: 2002-04-04
Also published as: AU2001292288A1; EP1321666A4; CN1214184C; JPWO2002027181A1; EP1321666A1; CN1466658A

Abstract

An engine starter capable of cranking a crankshaft finally in forward direction after driving in revere direction, wherein a motor is energized so as to be intermittently rotated in forward direction before the driving in reverse direction at least under specified conditions so that assured start can be performed at all times, whereby, as necessary, the crankshaft (piston) can be moved to an optimum position and, in addition, this control can be realized without using any special angle sensor.

Description

Technical field

The present invention is! _T Akira on Taido equipment

Background art

2. Description of the Related Art Conventionally, there is an automobile in which an engine is cranked by an electric motor and the electric motor is used as a generator. By doing so, one electric motor can serve as both the starting device and the generator, and the auxiliary equipment of the engine can be simplified.

Also, with the starter, since the piston position at the time of starting the engine is not constant, it is possible to start from a state where it stops at the position immediately before the compression stroke, and it is also possible to reliably start even in cold conditions where viscous resistance etc. is large. It is conceivable to increase the output of the motor to make it possible to start the motor immediately, but there is a problem that the motor becomes larger.

In order to enable starting under the above-mentioned conditions even when the output of the motor is small, it is preferable to use a pendulum type starting device that rotates the engine once at the start and then drives the engine forward. In this case, by reversing to the expansion stroke, a large approach section in the forward direction can be secured, and rebound due to compression pressure can be used. It will be possible to get enough rotation speed to get over the journey.

In the above-mentioned pendulum type starter, in order to ensure reliable starting with a small motor, a large approach section can always be secured to the crankshaft in the reverse direction toward the expansion stroke prior to reverse drive. Location, eg within or close to the compression stroke It is necessary to stop at the intake stroke position. Otherwise, if the engine load is heavy (ie, the viscous resistance is large), such as at low temperatures, the compression stroke in the expansion stroke can be reversed to a predetermined position during the ascent at normal temperature, but just before the expansion stroke. There is a risk of stopping at Conversely, when the engine load is light, such as at high temperatures, there is a risk that the engine will reverse until it exceeds the top dead center of the expansion stroke.

However, the crankshaft angle (piston position) when the engine is stopped can generally be estimated, but cannot always be said to be the same. If the reverse drive amount is set in consideration of the error, a sufficient approach section cannot always be obtained, and the motor Cannot be reduced as much as possible. In order to know the piston position, it is conceivable to provide an encoder or the like, but there is a problem that the price of the device rises. Disclosure of the invention

In view of such problems of the prior art, a main object of the present invention is to move a crankshaft (piston) to an optimal position as necessary so that a reliable start can be always performed. It is another object of the present invention to provide a starting device for performing a pendulum starting operation.

A second object of the present invention is to provide a starting device capable of starting an engine reliably and with minimum power consumption.

A third object of the present invention is to provide a starting device capable of simplifying a crankshaft angular position sensor used in such a starting device and minimizing the cost of the device.

A fourth object of the present invention is to provide a starting device suitable for adopting an idle stop structure that requires frequent restarts.

A fifth object of the present invention is to provide a starting device suitable for using an electric motor also serving as a generator.

Such an object is, according to the invention, for the crankshaft of the engine to be started. An engine starting device that drives a crankshaft in a reverse direction by an electric motor connected to the crankshaft, and finally cranks the engine in a forward rotation direction, wherein the electric motor connected to the crankshaft and the crankshaft A sensor for detecting an angular position, and a controller for controlling energization of the electric motor based on an output signal of the sensor, wherein the controller, at least under predetermined conditions, precedes the reverse driving. The present invention is attained by providing an engine starting device characterized in that the motor is adapted to energize the electric motor in a forward rotation direction.

According to this, in a state where the crankshaft is driven forward in advance and moved to the position within the compression stroke, the crankshaft is temporarily stopped, so that the repulsive force of the compression pressure is used, and a sufficient approaching distance is provided in the reverse direction. After driving, it is possible to finally clamp in the forward direction, and a reliable start can be expected. In particular, if the drive is performed in the normal forward direction with a small torque due to intermittent drive or intermittent drive, idling is stopped when waiting for a signal (idle stop), or when starting when re-riding. Even if the engine is hot enough and the friction loss is small, the rotation speed will be too high to get over the top dead center, and if it is compressed to just before the top dead center, a large compression repulsion will occur, causing a large reversal force. It is possible to prevent the subsequent start start position from being greatly deviated from an appropriate position due to being rebounded.

Further, the crankshaft angular position to be switched from the intermittent forward rotation to the reverse drive is determined by a predetermined return direction rotation angle with respect to the energization drive direction when the intermittent forward rotation is turned off. The position where the push-back is performed a predetermined number of times is set as a position where the push-back is performed a predetermined number of times. This makes it possible to easily and inexpensively determine the crankshaft angular position to be switched to the reverse drive.

The crankshaft angle position sensor can provide the necessary angle information If there is, the crankshaft angular position to be switched from the intermittent forward rotation to the reverse drive is determined in advance, and when the output of the crankshaft angular position sensor detects that the angle has been reached, The electric motor may be switched to the reverse drive.

When the intermittent forward rotation is not performed, as in the case of the preliminary forward rotation, the expansion stroke is reversed to exceed the top dead center, or the compression stroke of the expansion stroke is reduced. In order to avoid being bounced off by force, the reverse drive can be performed intermittently.

A sensor for detecting at least one of the battery voltage and the engine temperature, and only when at least one of the battery voltage and the engine temperature is lower than a predetermined lower limit from an output signal of the sensor. However, if the intermittent forward rotation is performed, only when the battery voltage is low or the engine temperature is low, the crankshaft rotates once and then reverses, and the expansion stroke is reversed. This prevents the battery from being rebounded by the compression repulsion force at the time of starting, and allows quick and minimal power consumption starting according to the situation.

In particular, when restarting at the time of the engine, such as in the case of idling stop or starting at the time of re-riding, the friction is small, and it is easy to be bounced off by the compression repulsion, so it is merely an intermittent forward rotation direction In some cases, the crankshaft angular position may not be able to reach the position within the predetermined compression stroke due to the current supply. In such a case, intermittent forward direction power supply may be repeated. In order to make the crankshaft angular position effectively reach the position within the predetermined compression stroke, it is preferable to gradually reduce the energization duty ratio when intermittent energization in the normal rotation direction is repeated.

In order to be able to obtain necessary angle information without using an expensive encoder or the like, the crankshaft angle position sensor is required to have an absolute position sensor that gives an absolute angular position of the crankshaft, and a higher resolution. A relative position sensor for detecting a change in the angle of the crankshaft. It is preferable that the absolute angular position of the crankshaft can be obtained with high resolution. For example, the absolute position sensor may include an ignition timing sensor, the electric motor may include a brushless motor, and the relative position sensor may include a commutation signal sensor of the brushless motor.

In such a case, the angle position of the crankshaft to be shifted from the reverse drive to the final cranking in the forward rotation direction is determined based on the output generated by the ignition timing sensor during the exhaust stroke of the engine. The determination can be made based on the output of the relative position sensor. As a result, the absolute angular position of the crankshaft can be obtained at a high resolution, so that the absolute angular position of the crankshaft can be used not only for starting control but also for ignition control and electronic fuel injection control.

Since the ignition timing sensor normally generates output signals in both the compression stroke and the exhaust stroke, it is important to distinguish between them in order to know the absolute angular position of the crankshaft. From such considerations, it is preferable that the detection by the ignition timing sensor be invalidated within a predetermined angle after the intermittent preliminary energization in the normal rotation direction and after the reverse rotation drive.

If the relative position sensor can detect the direction of rotation, such as a commutation signal sensor of a brushless motor, the final position is determined based on the detected direction of rotation and the result of detection by the ignition timing sensor. The output generated by the ignition timing sensor during the exhaust stroke of the engine can be identified so as to be a reference for shifting to the cranking in the normal forward direction. It is also possible to identify the output generated by the ignition timing sensor during the exhaust stroke of the engine based on the detected time point of reversal of the rotational direction so as to serve as a reference for shifting to the final forward direction cranking. it can. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic configuration diagram of an engine starting device to which the present invention is applied.

FIG. 2 is a fragmentary longitudinal sectional view of an engine starting device to which the present invention is applied. FIG. 3 is an end view of a partly broken main part taken along the arrow ΙΠ_ΙΙΙ line in FIG.

FIG. 4 is a schematic circuit configuration diagram of an engine starting device to which the present invention is applied.

FIG. 5 is a diagram showing a commutation signal of a motor (brushless motor) to which the present invention is applied.

FIG. 6 is a flowchart showing a control flow according to the present invention.

FIG. 7 is an explanatory diagram showing a change in stroke in a case where the preliminary forward drive of the four-stroke engine to which the present invention is applied is not performed.

FIG. 8 is an explanatory diagram corresponding to the control procedure in FIG.

FIG. 9 is a time chart corresponding to the control procedure in FIG.

FIG. 10 is an explanatory diagram showing a change in stroke when performing preliminary forward drive of a four-cycle engine to which the present invention is applied.

FIG. 11 is an explanatory view corresponding to the control procedure in FIG.

FIG. 12 is a time chart corresponding to the control procedure in FIG.

FIG. 13 is a process change explanatory diagram for explaining a configuration for avoiding erroneous recognition of the output of the ignition timing sensor when performing preliminary forward drive of a four-cycle engine to which the present invention is applied.

FIG. 14 is an explanatory diagram corresponding to the control procedure in FIG.

FIG. 15 is a time chart corresponding to the control procedure in FIG.

FIGS. 16 to 18 are time charts for explaining another configuration for avoiding erroneous recognition of the output of the ignition timing sensor when performing preliminary forward rotation of the four-cycle engine to which the present invention is applied. .

FIG. 19 is a time chart for explaining another configuration for avoiding erroneous recognition of the output of the ignition timing sensor when performing preliminary forward rotation driving of the four-cycle engine to which the present invention is applied.

FIG. 20 illustrates yet another configuration for avoiding erroneous recognition of the output of the ignition timing sensor when performing preliminary forward drive of a four-cycle engine to which the present invention is applied. Time chart.

FIG. 21 is a time chart for explaining still another configuration for avoiding erroneous recognition of the output of the ignition timing sensor when performing preliminary forward drive of a four-cycle engine to which the present invention is applied. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a schematic configuration diagram of an engine starting device to which the present invention is applied. As shown in FIG. 1, the electric motor (generator) 1 of the present starting device is provided coaxially and directly connected to the crankshaft 2 of the four-stroke engine ENG, and performs cranking at the time of starting. It is designed to be used as a generator while the engine is running. Further, each signal of an induction switch IG and a star switch ST is input to a controller ECU that controls the motor 1 and the engine ENG. An ignition signal P and a fuel injection signal F are output from the controller ECU to the engine ENG.

Next, the structure of the electric motor 1 will be described below with reference to FIGS. As shown in the figure, the electric motor 1 has a flat bottomed cylindrical opening 3 which is coaxially fixed to the crankshaft 2 of the engine ENG and also serves as a flywheel. Evening mouth — A predetermined number of arc-shaped magnets 4 are fixed to the inner peripheral surface of the cylindrical portion of evening 3 so that the N and S poles are alternately arranged in the circumferential direction.

The motor 1 further has an inner stator 5 coaxially arranged to cooperate with the outer rotor 3. The inner stay 5 is provided inside the peripheral wall of the rotor 3 so as to face the magnetic poles of the magnet 4 and radially with respect to the crankshaft 2. It has a core 7 and a stay coil 6 wound around each stay core, and is fixed to an end face of the engine ENG by screwing with a fixed port 11. As shown in FIG. 4, each stage coil 6 responds to a motor control signal from a CPU in the controller ECU. It is connected to each drive element, such as an FET, in a motor dryino 14 for driving the motor 1. Note that this ACG Star has a three-phase brushless motor structure, and the MONO DRYNO 14 has two FETs for high, single-mouth driving for each of U, V, and W phases. The middle part of the pair of high-low FETs is connected to the staying coils 6 of each phase.

A reluctor 8 made of a magnetic material is fixed to the outer peripheral surface of the peripheral wall of the rotor 3. A pulsar (magnetic detection coil) 9 is fixed to an end face of the engine ENG via a bracket 10 so that the pulsar 9 (magnetic detection coil) 9 faces the outer peripheral surface of the peripheral wall of the rotor 3 by a mounting port 12. . The pulsar 9 forms an ignition timing sensor in cooperation with the reluctor 8 by detecting a magnetic change caused by the passage of the reluctor 8. Three Hall elements 13 constituting a commutation position detection sensor are disposed inside the inner steering unit 5 of the motor 1. Further, the outer rotor 3 is provided with an annular sensor magnet 15 as an object to be detected on an outer peripheral surface of a protruding end of a boss protruding toward the engine body. Each of the Hall elements 13 is fixed to a proper position of the inverter 5 via a positioning case in order to detect a change in the magnetic pole position of the sensor magnet 15. As shown in FIG. 3, three Hall elements 13 are arranged at predetermined regular angular pitches in the circumferential direction corresponding to the U, V, and W phases.

As shown in Figs. 1 and 4, the controller ECU monitors the engine temperature TE and the battery voltage BT. In accordance with the detected values, for example, based on table data stored in advance in ROM, the control can be changed to perform an efficient and appropriate preliminary operation. The engine temperature TE is determined by the temperature of the engine, such as the temperature of the cooling water in a water-cooled engine, the ambient temperature in the engine room, the temperature of the electric motor (generator) 1, and the temperature of the controller ECU when installed in the engine room. What is necessary is just to give an index of the temperature of that part. Next, the starting procedure of the thus-configured starting apparatus will be described below. In this embodiment, since a three-phase brushless motor is used, the Hall element 13 has the rising (L → H) / falling (H → H) of the U, V, and W phases as shown in FIG. (→ L) timing, and the change of rotation angle can be determined in units of 10 degrees based on the commutation position signal from the Hall element 13 from the combination of these phase states. . In this case, since the number of combinations is six, the same combination is repeated every 60 degrees. Although the relative angle change can be detected by itself, the absolute angle cannot be determined.

Since this engine ENG is a four-stroke engine, as shown in FIG. 7, the compression, expansion, exhaust, and intake strokes are performed while the crankshaft rotates twice, that is, 720 degrees. The pulsar 9 is located slightly before the top dead center between the compression and expansion strokes (0 1) and slightly before the top dead center between the exhaust and intake strokes (0 2), that is, 0 1 3 6 At a position separated by 0 degrees, the passage of the reactor 8 is detected. Here, Θ1 is called an ignition timing reference position, and 02 is called an angle calculation reference position. At this time, since the reluctor 8 has a predetermined width, the pulsar 9 generates pulses having polarities opposite to each other with the passage of the leading edge and the trailing edge of the reluctor 8, thereby causing the pulser 9 to move to the position of the reluctor 8. Generate the corresponding signal. Here, the pulsar 9 can determine the absolute angular position of the reductor 8, but can detect only one point in 360 degrees by itself, and whether it is in the compression stroke or the exhaust stroke. Cannot be distinguished.

When the engine ENG is stopped, the crankshaft is expected to be in the exhaust or intake stroke, but its position cannot usually be specified. Therefore, if it is attempted to start the engine suitably by driving the crankshaft reversely before the final forward rotation start operation (pendulum start operation), how much the crankshaft should be driven in reverse rotation I can't judge. In other words, depending on the position of the crankshaft at the time of starting, even if it is driven in reverse, the expansion stroke is reversed Due to the compression resistance at the time, the crankshaft is not fully reversed, so that a sufficient approaching distance, that is, a final forward drive with a sufficient pendulum action, cannot be performed, or conversely, the top dead center is increased from the side of the expansion stroke. It can be exceeded. Therefore, in this embodiment, prior to the pendulum starting operation, the crankshaft is driven forward (preliminary forward drive) as necessary, within a range not exceeding the top dead center of the compression / expansion stroke. In addition, the pendulum starting operation is performed after securing a sufficient approach distance for the reverse rotation drive. Also, when the engine is started in a warm state, such as when restarting after an idle stop, friction loss is small, and a preliminary forward drive is not required. Even if the preliminary forward drive is not performed, the problem that the reverse drive becomes excessive and the top dead center is reversed from the expansion stroke side must be considered.

In this starting device, first, when the induction switch IG is turned on, a predetermined preparatory operation is performed, and then the starter switch ST is turned on to perform cranking. The cranking may be a simple forward drive only cranking or a pendulum cranking consisting of reverse / forward drive. This operation is automatically performed during a series of operations in which the driver turns on the identification switch IG and then turns on the switch ST overnight.

As shown in FIG. 6, in the first step ST1, it is determined whether or not the battery voltage BT is lower than a predetermined lower limit BTL. If the battery voltage BT is higher, the process proceeds to the second step ST2, where the engine temperature is determined. It is determined whether TE is lower than a predetermined lower limit TEL. If higher, the process proceeds to the third step ST3.

In the third step ST3, since it is determined that the preliminary forward drive is unnecessary, the preliminary reverse drive before turning on the star switch ST is indicated by the arrow A in Figs. 7 and 8. Intermittently in the reverse direction. As shown in FIG. 9, the power-on time t1 during intermittent driving is, for example, about 5 Oms, and the power-off time t2 may be the same. Intermittent drive is used when the engine is started in a warm state, such as when the battery voltage is high or when restarting after an idle stop. 'This is to prevent the reverse rotation drive from becoming excessive due to a small amount of Yon-Loss, so that the top dead center does not move backward from the expansion stroke side. Therefore, if there is no possibility that the top dead center will be reversed from the expansion stroke side by taking measures to prevent the reverse drive from becoming excessive, the reverse drive should not be performed intermittently. And can be continuous.

Then, in a fourth step ST4, it is determined whether or not the compression start position Θe set at the middle position of the expansion stroke has been reached as shown in FIGS. The determination as to whether or not the compression start position 0e has been reached is made by utilizing the fact that the compression pressure is increased by reversing the expansion stroke and a repulsive force is generated by the compression pressure. That is, based on the commutation position signal from the Hall element 13, when the energization is turned off, it is pushed back more than a predetermined rotation angle (for example, 20 degrees) with respect to the normal rotation direction a predetermined number of times (one or more times) When the above is detected, or when the power is turned on, a predetermined rotation angle in the reverse direction

(E.g., 20 degrees) may be a case where rotation of less than or equal to a predetermined number of times (one or more times) is detected. However, as a result of past control operations, if the absolute angular position of the crankshaft is known, including stroke distinction, or if the angle sensor can provide such information, the crankshaft angular position will be At this time, it is also possible to detect that the compression start position 0e has been reached and stop the reverse rotation drive.

If it is determined in the fourth step ST4 that the compression start position 0e has been reached, the operation proceeds to the fifth step ST5. In the fifth step ST5, since the position detected as the compression start position in the fourth step ST4 cannot be considered to be an accurate position, the position is set as the temporary compression start position 0e. Then, proceed to the sixth step ST6.

Then, in the sixth step ST6, the final forward drive is performed. Note that when the compression start position 0e is detected, as shown in Figs. 7 and 8, the standstill is in a state of stopping in the position within the expansion stroke. 7 and 8, the motor 1 is continuously energized so as to be driven in the forward direction as shown by the arrow B in FIGS. When starting in this way, a sufficient approach section from the position within the expansion stroke to the compression stroke is secured, and the rebound of the compression pressure can be used, so that the top dead center of the compression stroke can be overcome. An increase in rotation speed can be expected. In this forward rotation, as shown in FIGS. 7 and 8, when the passage of the reductor 8 is detected as a pulsar output signal during the passage of the exhaust stroke, the detected position is set as the angle calculation reference position 02, and the temporary compression start position is set. Instead of 0 e, it is used as the reference for the regular angular position. This angular position can be used for timing control such as starting, ignition or fuel injection as a reference for knowing the absolute angle.

In the present embodiment, the conditions under which a sufficient increase in the rotation speed in the final forward rotation cranking can be expected without the need for a preliminary forward rotation drive are defined in the first step ST1 and the second step ST2. The determination is made based on the battery voltage BT and the engine temperature TE. When the battery voltage BT is lower than the lower limit value BTL, the driving torque of the motor 1 is low, and when the engine temperature TE is lower than the lower limit value TEL, it can be determined that the friction loss is large due to a large viscous resistance, and in any case, Unless preliminary forward rotation is performed, a sufficient increase in the rotation speed in the final forward rotation cranking cannot be expected. In those cases, proceed to the seventh step ST7.

In the seventh step ST7, in contrast to the third step ST3, preliminary forward drive, that is, intermittent drive in the forward direction is performed as shown by an arrow C in FIGS. 10 and 11. In this case, if measures are taken to prevent the top dead center from being exceeded from the compression stroke side and to move the crankshaft position to a position within the compression stroke prior to the reverse rotation drive, preliminary measures can be taken. The forward rotation drive can be performed continuously instead of intermittently. In the next eighth step ST8, as shown in FIGS. 10 and 11, it is determined whether or not the compression start position 0p in the compression stroke has been reached in the same manner as in the fourth step ST4. That is, based on the commutation position signal from the Hall element 13, it is detected that the push-back by more than a predetermined rotation angle (for example, 20 degrees) with respect to the reverse rotation direction is performed a predetermined number of times (one or more times) when the power is turned off. Or a case where it is detected that the motor rotates only less than or equal to a predetermined rotation angle (for example, 20 degrees) in the normal rotation direction at the time of energization is detected for a predetermined number of times (one or more times). If it is determined that the compression start position θρ has been reached, the process proceeds to the ninth step ST9.In the ninth step ST9, the position is set as a temporary compression start position 0ρ as in the fifth step ST5. 10. Go to step ST10. In this case as well, if the absolute angle position of the crankshaft is known including the distinction of the stroke as a result of the past control operation, or if the angle sensor can provide such information, the crankshaft angle position can be changed. It is also possible to stop the normal rotation drive by detecting that the compression start position 0 ° has actually been reached.

In the 10th step ST10, pendulum start control is performed. When the compression start position 0Ρ is detected, as shown in Figs. 10 and 11, it stands by at the position inside the compression stroke and stands by. As shown in (1), when the starter switch ST is turned on, the motor 1 is continuously energized to perform reverse drive from the standby position (see FIG. 12). At the time of this reverse rotation, as shown in FIGS. 10 and 11, when the passage of the reductor 8 is detected as a pulsar output signal during the passage of the exhaust stroke, the detected position is set as the angle calculation reference position 02, and the temporary compression start position is set. Instead of 0 °, it is used as the reference for the regular angle position. This angular position can be used for timing control such as starting, ignition or fuel injection as a reference for knowing the absolute angle.

The normal compression start position Θ e when reversing the expansion stroke based on the angle calculation reference position 0 2 can be obtained, and when the compression start position 0 e is reached, the power supply to the motor 1 is stopped in the same manner as above. Reverse the expansion stroke by inertia. After stopping and reversing in the middle of the expansion stroke (Θ4), the motor 1 is continuously energized so as to drive in the forward direction (arrow E in FIGS. 9 and 11) and crank. Thus, the clan When the inertia force of the crankshaft balances with the compressive force caused by reversing the expansion stroke and the crankshaft is driven forward for the first time when the crankshaft stops and reverses, so that the motor rotates forward immediately after the reverse drive. Power consumption can be reduced compared to

In this way, even if the viscous resistance is high due to the low temperature and the friction loss is large, once the motor rotates in the forward direction to the compression stroke and then reverses, the run-in section is long and the reverse drive is performed. Therefore, the rotation speed at the time of reversing the expansion stroke can be sufficiently increased. Furthermore, the compression repulsion caused by the increase in the compression pressure when the expansion stroke is reversed causes a force to push back the piston, and the rotation speed can be increased by a sufficient approach section in the normal rotation direction. Therefore, a torque that can easily get over the top dead center in the compression stroke at the time of forward rotation can be generated, so that the motor 1 with a small rated output can be started even when the friction loss is large.

For example, when idling is stopped at a traffic light or the like, the angular position information is stored as an absolute value because the identification switch IG remains on, so such restart control at idle stop is This can be performed based on the stored angle calculation reference position 02. It can also be used for ignition control or electronic fuel injection control at start-up or normal time.

In this case, when the angle position is obtained from the angle calculation reference position Θ2, it can be used as a regular absolute angle position. On the other hand, when it is obtained from the change in the rotation speed of the crankshaft 2 at the time of compression rebound, it is used as a tentative absolute value, but since it does not differ greatly, for example, the expansion stroke at startup is reversed. There is no problem in finding the optimum reversal position when starting using the compression repulsion obtained by this, or using it for ignition control or electronic fuel injection control at the time of starting.

At the end of the preparatory operation, when the engine is stopped during idle stop, or when the engine is stopped, a predetermined rotation angle (for example, 20 °) from the compression start position 0 e (θ p) (Degrees) There is a case where it stops in a place more than. In such a case, according to the present invention, the preliminary operation is performed again. This makes it possible to perform a suitable restart while securing a sufficient approach section, regardless of whether the start control is to be performed in the normal rotation or the Z inversion.

When stopping at a position far from the compression start position 0 e (θ p), it is considered that the rebound due to the compression repulsion force in the expansion or compression stroke is large, so when performing the above-mentioned preliminary operation again In this case, it is preferable to set an energization ON time shorter than the energization ON time t1 in the preliminary operation before that. As a result, the above-mentioned rebound can be reduced, and it can be stopped near the expansion or compression stroke.

Further, it is preferable that the lengths of the power-on time t1 and the power-off time t2 in the preliminary operation are changed based on at least one of the battery voltage BT and the engine temperature TE. For example, when the battery voltage is low or the engine is cold, the energization ON time t1 is increased and the energization OFF time t2 is further reduced.On the other hand, when the battery voltage is high or the engine temperature is high, the energization ON time or 1 is decreased. At the same time, the energization off time t 2 can be further increased. As a result, it is possible to perform optimal start control according to a change in the engine start environment.

If it is not likely to stop within a predetermined angle (for example, 20 degrees) from the compression start position after the detection of the compression start position during the preparatory operation, the low side of the driver circuit 14 after the detection of the predetermined angle. It is recommended that the power generation (regeneration) braking by the motor 1 be applied by turning on all of the FETs to stop the crankshaft 2 within a predetermined angle from the compression start position. This makes it possible to avoid repeating the preliminary operation again.

Next, a second embodiment of the present invention will be described. In the second embodiment, the ignition switch IG is first turned on, and then the start switch ST is turned on to perform cranking. At this time, as shown in FIG. When the IG is turned on, first, the motor 1 is intermittently driven in the normal rotation direction to execute a preliminary normal rotation drive. The energization ON time t1 during this intermittent drive may be, for example, about 50 ms. In this case as well, a precautionary measure should be taken to avoid exceeding the top dead center from the compression stroke side and to move the crankshaft position to the position within the compression stroke prior to the reverse rotation drive. Forward drive can be performed continuously instead of intermittently.

In addition, when the identification switch IG is in the ON state, the rotation angle of the crankshaft 2 (keyhole-evening 3) is counted based on the commutation position signal of the brushless motor, and counting is started with the reference signal described later. In the illustrated example, a three-phase brushless motor is used for the electric motor 1, and the above-described Hall element 13 causes each phase U · V as shown in FIG. 6 used in the description of the previous embodiment. Thus, a relative angle sensor that detects the rising (L → H) / falling (H → L) timing and counts the rotation angle at every 10 degrees in this way is configured. In this preliminary forward drive, the compression stroke of the four-stroke engine ENG is rotated to just before the top dead center of the compression stroke as shown by the arrow A in FIGS. 13 and 14. As control for this, the rotation speed can be calculated from the above rotation angle count, so if it is determined that the rotation speed has stopped in the power-off state during intermittent drive, the piston will rise to near the top dead center. As a result, the cylinder pressure rises, and it can be determined that the piston has stopped due to the compression pressure. At that point, the forward rotation drive is stopped. In the intermittent drive, the crankshaft 2 can be rotated until the top dead center cannot be exceeded (torque that can overcome the compression repulsion cannot be generated). This is because the rotation can be performed until the angle substantially matches the predetermined angle (01).

Then, the electric motor 1 is driven in the reverse direction when the switch ST is turned on (arrow B in FIGS. 13 and 14). At this time, in the illustrated example of the four-stroke engine, the passage (return angle calculation reference position 0 2) of the reluctor 8 is detected by the pulser 9 in the exhaust stroke. As a result, a signal similar to that of the ignition timing reference position 01 is generated. From the angle calculation reference position 02, the rotation angle is counted again, and the predetermined angle α is counted.When the reverse rotation stop position 03 set within the expansion stroke is reached, the motor 1 is driven in the reverse direction. Is stopped, and the motor 1 is driven in the forward direction from the forward / reverse position 0 4 where the inertia force in the reverse direction and the compression repulsion force rising by reversing the expansion stroke are balanced (FIGS. 13 and 1). 4 arrow C). In this way, when the inertia of the crankshaft balances with the compressive force caused by reversing the expansion stroke and the crankshaft stops and reverses (0 4), the forward rotation is performed for the first time. Θ 3) Power consumption can be reduced as compared with the case of starting forward drive. As a result, a compression repulsion force caused by an increase in compression pressure when the expansion stroke is reversed causes a force to push back the piston, and provides an assisting force in a forward rotation direction to secure a sufficient approaching section. As a result, the torque that can easily overcome the top dead center during the compression stroke during forward rotation can be generated by increasing the rotation speed, so that the motor 1 with a small rated output can be easily used. Cranking can be performed.

By the way, during the first preliminary forward drive described above, the crankshaft 2 is rotated forward to a position (the imaginary line D in FIGS. 13 and 14) at which the pulser 9 can detect the initial end (tip) of the reluctor 8 for some reason. In the case of rotation in the reverse direction, the end is detected even after the reversal, and in such a case, an erroneous detection signal G is detected as shown by the imaginary line in FIG. Then, the erroneous detection signal G is erroneously recognized as the angle calculation reference position signal 、 2, and the erroneous recognition inversion position 0 5 (see FIG. 13) counting a predetermined angle from the ignition timing reference position 0 1 is detected. Stop reverse drive. Then, after stopping after idling from the false recognition reversal position S5, the motor is driven forward as shown by the imaginary line arrow E in FIG. 13, so that no assist force is obtained, and furthermore, the approach during the forward drive is performed. There is a possibility that the number of sections will be reduced (about half of the above), and it will not be possible to reach the rotation speed enough to get over the top dead center. On the other hand, in the present invention, in order to prevent the generation of the erroneous detection signal G, a predetermined angle after the electric motor 1 changes from the normal rotation to the reverse rotation is set to invalidate the signal detection by the pulsar 9. The mask section M is defined as Note that the angle of the mask section M may be larger than the angle at which the reluctor 8 can be detected by the pulsar 9 and somewhat smaller than 360 degrees until the angle calculation reference position signal 02 can be generated. For example, it may be about 200 degrees.

Next, another embodiment for avoiding erroneous detection of the relaxation time 8 by the pulsar 9 as a reference for obtaining the absolute angle will be described below with reference to FIGS. The pulsar 9 in this starting device detects a signal generated when the first end and the last end of the reluctor 8 pass. The pulsar detection signal in the normal rotation direction during normal operation is shown in FIG. As shown in FIG. 6, a negative first reference pulse p 1 is generated when the reluctor 8 passes through the first end, and a positive second reference pulse P 2 is generated when the reluctor 8 passes through the end. By integrating these reference pulses, a pulsar output (pulsar reluctor) signal is generated as a square wave corresponding to the position of the reluctor 8. In the following control, it does not matter whether the reference pulses P 1 and P 2 are positive or negative.

When detecting the passage of the reactor 8 in the exhaust stroke at the time of reverse rotation in the start control, as shown in Fig. 17, the second reference pulse P2 is generated first, and then the first reference pulse P1 is generated. Then, the same pulsar output signal as above is generated. At the time of preliminary forward driving, if it does not reach 0 1, the second reference pulse P 2 obtained first can be recognized as the angle calculation reference position signal 02 at the time of reverse rotation.

On the other hand, when the crankshaft 2 rotates to the position where the first end of the reductor 8 is detected at the time of the first preliminary forward rotation, which is the problem described above, and then reverses from the middle of the reluctor 8, FIG. As shown in (1), the rising of the first reference pulse P1 is detected in the forward rotation direction, and the rising of the first reference pulse P1 is detected again in the reverse rotation direction after the inversion. In this way, each reference pulse is Since it occurs at the time of turning, it is possible to determine that it is different from the case of FIG. 17, and thus erroneous detection can be prevented. The normal rotation and the reverse rotation can be determined by checking the appearance order of the U, V, and W phases shown in FIG.

Further, as another modified embodiment of the procedure for preventing erroneous detection by comparison with the rotation direction at the time of generation of the reference pulse, rotation is performed only at the time of reverse rotation in order to continue reverse drive by a predetermined angle α from the angle calculation reference position 02. Since the angle only needs to be counted, the counting of the rotation angle can be limited to the reverse rotation. Therefore, if the time when the first reference pulse # 1 is generated in the forward rotation as in the case of FIG. 18, it is not the reference pulse corresponding to the angle calculation reference position 02 for performing the rotation angle force counting. Judgment can be made, and erroneous detection can be prevented.

Still another embodiment for avoiding erroneous detection of the reluctor .8 by the pulsar 9, which is to be a reference for obtaining the absolute angle, will be described below with reference to FIG. In this embodiment, when the reference pulses Ρ 1 and Ρ 2 are generated and the states of the U, V and W phases are associated in advance, it is determined whether or not the state is normal. . First, in the case of forward rotation, when the first reference pulse Ρ 1 is generated Τ 1, L · L ·, and when the second reference pulse Ρ 2 is generated Τ 2, L · Η · L So that Conversely, when such a change in state is detected, it can be determined that the vehicle is in the normal rotation state.

On the other hand, when the passage of the reluctor 8 is detected at the time of reverse rotation, the second reference pulse まず 2 is first generated as shown by the imaginary line in FIG. · Each state of W phase is L · L · L. Then, as shown by the imaginary line, when the first reference pulse Ρ 1 occurs では 4 at L Τ L Τ 、 It can be determined that the passage of the reductor 8 has been detected during the reverse rotation. The state shown by the inversion in FIG. 19 is a state in which the first reference pulse Ρ1 is generated at the first forward rotation, and the state is inverted and reversed before the second reference pulse Ρ2 is generated. In this case, the states of the U, V, and W phases are L, L, and H at the time T1 occurs when the first reference pulse P1 occurs, and then the first reference pulse P1 is imaginary at the time of reverse rotation. As shown in Fig. 5, when the occurrence occurs, L · L · Η again occurs at T4, and this state change does not correspond to any of the above two states (forward rotation / reverse rotation state). Can be determined to be different from this, and erroneous detection can be prevented in this way.

However, if any one of the U, V, and W phases changes during the generation of any of the reference pulses, a normal forward / reverse rotation state may not be distinguished. For example, as shown in FIG. 20, both the reference states are changed so that the state of the U phase changes during the generation of the first reference pulse Ρ1 and the state of the V phase changes during the generation of the second reference pulse Ρ2. It is assumed that the state of the U, V, and W phases at the time of generation of the pulses Ρ 1 Ρ Ρ 2 was previously associated. That is, one cycle of each of the U, V, and W phases is 60 degrees, whereas the width of the reluctor 8 is determined to be 50 degrees. Therefore, during the forward rotation, the states of the U, V, and W phases are L, L, and L between the time point 時点 1 when the first reference pulse Ρ1 is generated and the time point Τ2 when the second reference pulse Ρ2 is generated. From Η to L · Η · 、, and during reverse rotation, from the time Τ 3 when the second reference pulse Ρ 2 occurs to the time Τ 4 when the first reference pulse ρ 1 occurs, from L · L · 時にはChanges to Η · L · Η. When passing through the first end of Reactor 8 at the time of forward rotation and reversing in the middle of Retractor 8, and passing through the first end of Relaxation 8 in the opposite direction this time, each state of U, V, W phase Changes from L · L · の at time point Τ 1 to Η · L · の at time point Τ 4. Therefore, the inverted state cannot be distinguished from the inverted state.

In such a case, such a problem can be avoided by performing the detection of the reference pulse at least partially at the time of falling, instead of at the time of generation of the pulse, that is, at the time of rising. When the falling time is used as a reference, the states of the u′v′w phase change from Η · L. «At time T 4 to L·L · Η at time T3 during forward rotation, and during reverse rotation. , From the time point L 2 Η Η 時点 to the time point T 1 · L · LΗ. Anti At the time of rotation, the state changes from H · L · H at time T4 to L·L · H at time T1. Therefore, the reversal state cannot be distinguished from the normal rotation, but can be distinguished from the reverse rotation state, and there is no possibility that the ignition timing reference position 01 is confused with the angle calculation reference position 02 during the reverse rotation. it can.

A further embodiment for avoiding erroneous detection of the reluctor 8 by the pulser 9 which is to be a reference for obtaining the absolute angle will be described below with reference to FIG. In this embodiment, the inversion state is determined by monitoring changes in the U, V, and W phases, and the U, V, and W phases are determined as described above. To

Since any one of the phases switches from rising to falling every 10 degrees, it is detected at each switching timing and the state change is observed.

In the illustrated example, as shown in FIG. 21, the state of each phase is monitored in each section Ta to Tg between each detection timing (10-degree pitch). The U, V, and W phases change in the order of LHH, LLH, HLH, HLL, HHL, LHL, LHH when the crankshaft rotates forward, and when the crankshaft rotates reversely. It changes in the reverse order. However, in the case of passing through the first end of the reluctor 8 at the time of the forward rotation, being reversed in the middle of the reluctor 8, and passing through the first end of the reluctor 8 this time in the opposite direction, this order is lost. For example, when inverted in the section Td corresponding to the middle of the reluctor 8, each state of the U'V'W phase changes in the order of LHH, LLH, HLH, HLL, HLH, LLH, LHH, and is clear from the reverse. Can be distinguished. In this case, there is no need to consider the timing of the generation of the reference pulses P 1 and P 2, so what is the timing of the generation of the reference pulse and the timing of the generation of the commutation pulse (change of each phase)? It is also possible to prevent the erroneous detection. Therefore, there is no need to assemble them with the exact positional relationship between them.

In the illustrated example, a four-cycle engine is shown, but according to the present invention, if a similar reluctor is provided on the bottom dead center side, the present invention can be applied to a two-cycle engine as it is. As described above, the present invention has been described with respect to the specific embodiments. However, those skilled in the art can make various modifications and changes without departing from the concept of the present invention described in the claims.

Claims

The scope of the claims

1. An engine starting device for driving a crankshaft in a reverse direction by an electric motor connected to the crankshaft of an engine to be started, and finally cranking the engine in a forward direction,

An electric motor connected to the crankshaft;

A sensor for detecting the angular position of the crankshaft;

A controller for controlling energization of the electric motor based on the output signal of the sensor,

An engine starting device, characterized in that the controller is adapted to energize the electric motor in a forward direction at least under predetermined conditions prior to the reverse driving.

2. The engine starting device according to claim 1, wherein the energization in the forward rotation direction is intermittent.

3. The crankshaft angular position to be switched from the intermittent forward direction energization to the reverse direction drive is changed to the predetermined return direction rotation with respect to the energizing drive direction when the intermittent forward direction energization is turned off. 3. The engine starting device according to claim 2, wherein the pushing back by an angle or more is a position detected a predetermined number of times.

4. The crankshaft angular position to be switched from the intermittent forward direction energization to the reverse direction drive is rotated only in the forward direction by a predetermined rotation angle or less when the intermittent forward direction energization is on. 3. The engine starting device according to claim 2, wherein the position is detected at a predetermined number of times.

5. The crankshaft angle position to be switched from the intermittent forward rotation to the reverse drive is determined in advance, and when the output of the crankshaft angle position sensor detects that the angle has been reached, 3. The engine starter according to claim 2, wherein the motor is switched to the reverse drive.

6. The engine starter according to claim 2, wherein the reverse drive is performed intermittently when the intermittent forward energization is not performed.

7. A sensor for detecting at least one of the battery voltage and the engine temperature is further provided, and at least one of the battery voltage and the engine temperature is lower than a predetermined lower limit value based on an output signal of the sensor. The engine according to claim 2, wherein the intermittent forward energization is performed only in the case.

8. The engine starting device according to claim 2, wherein the intermittent forward rotation is repeatedly performed until the crankshaft angular position reaches a position within a predetermined compression stroke.

9. When the intermittent forward energization is repeatedly performed until the crankshaft angular position reaches a position within a predetermined compression stroke, the energization duty ratio is gradually reduced. 8. The engine starting device according to 8.

10. If the intermittent forward energization is repeated until the crankshaft angular position reaches a position within a predetermined compression stroke, after the regenerative braking section, the reverse direction 9. The engine starting device according to claim 8, wherein driving is started.

11. The crankshaft angular position sensor has an absolute position sensor that gives an absolute angular position of the crankshaft, and a relative position sensor that detects a change in the angle of the crankshaft with higher resolution. 2. The engine starting device according to claim 1, wherein the absolute angle position of the crankshaft can be obtained with high resolution by combining the two.

12. The engine starting device according to claim 11, wherein the absolute position sensor includes an ignition timing sensor.

13. The motor according to claim 11, wherein the electric motor comprises a brushless motor, and the relative position sensor includes a commutation signal sensor of the brushless motor. Engine starter.

14 4. Before the transition from the reverse drive to the final forward cranking, the angular position of the crankshaft is determined based on the output generated by the ignition timing sensor during the exhaust stroke of the engine. 13. The engine starting device according to claim 12, wherein the determination is made based on an output of the relative position sensor.

15. The engine start according to claim 14, wherein the detection by the ignition timing sensor is invalidated within a predetermined angle after the reverse rotation driving after the forward rotation direction energization. apparatus.

16. The relative position sensor can detect the rotation direction, and the timing to shift to the final forward rotation cranking based on the detected rotation direction and the detection result by the ignition timing sensor. 15. The engine starter according to claim 14, wherein an output generated by the ignition timing sensor during an exhaust stroke of the engine is identified as much as possible.

17. The relative position sensor can detect the rotation direction and, based on the detected reversal of the rotation direction, set the reference to be the timing of the evening to shift to the final cranking in the normal rotation direction. 15. The engine starting device according to claim 14, wherein an output generated by the ignition timing sensor during an exhaust stroke of the engine is identified.