JP7284351B2 - Engine starting device and straddle-type vehicle - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine starter and, more particularly, to an engine starter that executes swingback control to reverse drive a crankshaft up to a predetermined range and then switch to normal drive when starting an engine.

Conventionally, there has been known a configuration in which an ACG starter motor that is driven by power supplied from a battery and generates power in a driven state is attached to the crankshaft of an engine.

Patent Literature 1 discloses an engine starter that controls an ACG starter motor to reverse drive a crankshaft up to a predetermined range and then performs swingback control to switch to normal drive when the engine is started. .

JP-A-2000-283010

However, in the technique of Patent Document 1, when stopping the reverse drive in the swing-back control, if the rotational speed of the ACG starter motor is equal to or higher than the predetermined value, it is stopped, and if the rotational speed is less than the predetermined value, the predetermined It is configured to stop after the elapse of time, and there is still room for improvement in how to stop it accurately within a desired range.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems of the prior art, and to provide an engine starter capable of accurately stopping reverse drive in swingback control within a desired range.

In order to achieve the above object, the present invention provides an ACG starter motor (50) that drives a crankshaft (C) of an engine (E) in the forward or reverse direction and generates power with the rotational force of the crankshaft (C). ), a crank angle sensor (40) for detecting the rotation state of the crankshaft (C), and the rotation speed (Ne) of the crankshaft (C) using the rotation state detected by the crank angle sensor (40) and a control unit (80) for controlling the driving and power generation of the ACG starter motor (50), wherein the control unit (80) controls the starting of the engine (E) When the rotational speed (Ne) exceeds a threshold value (Ne1) during the swing-back control, the control unit (80) executes swing-back control to reversely drive the crankshaft (C) to a predetermined range. The first point is that the output of the ACG starter motor (50) is reduced, and the output of the ACG starter motor (50) is increased when the rotation speed (Ne) becomes equal to or less than a threshold value (Ne1) during the swingback control. has the characteristics of

Further, after the swingback control, the control unit (80) drives the crankshaft (C) in the forward rotation direction until the engine (E) is completely started. When the rotation speed (Ne) exceeds a threshold value (Ne2) during forward rotation, the ACG starter motor (50) is stopped and the rotation speed (Ne ) becomes equal to or less than the threshold value (Ne2), the ACG starter motor (50) is driven.

Further, the control unit (80) determines that the engine (E) has been started when the rotation speed (Ne) exceeds an engine start completion threshold value (Ne3), and drives the ACG starter motor (50). There is a third feature in stopping the

A fourth characteristic is that the detection of the predetermined range for stopping the reverse drive in the swing-back control is performed by pushing back near the top dead center of the compression stroke.

Further, the crank angle sensor (40) includes a plurality of sensor elements, and the rotation speed calculation means (81) uses the plurality of sensor elements to calculate the rotation speed while the crankshaft (C) rotates once. A fifth feature is that (Ne) is calculated twice or more.

The sixth characteristic is that the predetermined range in which the reverse rotation is stopped in the swingback control is a position a little past the compression top dead center in the normal rotation direction.

A seventh feature is that the vehicle is a straddle-type vehicle equipped with an engine starter.

According to the first feature, an ACG starter motor (50) that drives a crankshaft (C) of an engine (E) in the forward or reverse direction and generates power by the rotational force of the crankshaft (C); calculating a rotation speed (Ne) of the crankshaft (C) using a crank angle sensor (40) for detecting the rotation state of the crankshaft (C) and the rotation state detected by the crank angle sensor (40); In an engine starting device (100) comprising a control section (80) for controlling driving and power generation of the ACG starter motor (50), the control section (80) controls the crank when starting the engine (E). A swing-back control is executed to reversely drive the shaft (C) to a predetermined range, and the control unit (80) controls the ACG starter motor when the rotation speed (Ne) exceeds a threshold value (Ne1) during the swing-back control. (50) is reduced and the output of the ACG starter motor (50) is increased when the rotation speed (Ne) becomes equal to or less than the threshold value (Ne1) during the swingback control. By switching ON/OFF of the driving according to the rotation speed of the ACG starter motor, the ACG starter motor can be accurately stopped within a predetermined range.

According to the second feature, the control unit (80) drives the crankshaft (C) in the forward rotation direction until the engine (E) is completely started after the swingback control, and the control unit (80) stops driving the ACG starter motor (50) when the rotational speed (Ne) exceeds a threshold value (Ne2) during driving in the forward direction, and stops driving the ACG starter motor (50) during driving in the forward direction; Since the ACG starter motor (50) is driven when the rotation speed (Ne) becomes equal to or lower than the threshold value (Ne2), the ACG starter motor (50) is driven until the engine is started in an unstable rotation state at low rotation where rotation fluctuation is likely to increase. It is supported by a starter motor, and reliable engine starting can be realized.

According to the third feature, the control unit (80) determines that the engine (E) has been started when the rotation speed (Ne) exceeds an engine start completion threshold value (Ne3), and the ACG starter Since the driving of the motor (50) is stopped, the completion of engine start-up can be confirmed by monitoring the number of revolutions.

According to the fourth feature, detection of the predetermined range for stopping the reverse drive in the swing-back control is performed by pushing back near the compression top dead center, so that it is possible to improve the accuracy of detection of the predetermined range.

According to the fifth feature, the crank angle sensor (40) includes a plurality of sensor elements, and the rotation speed calculation means (81) uses the plurality of sensor elements to rotate the crankshaft (C) by one rotation. Since the rotational speed (Ne) is calculated twice or more during one rotation of the crankshaft, more precise control becomes possible by calculating the rotational speed twice or more during one rotation of the crankshaft.

According to the sixth feature, the predetermined range in which the reverse rotation is stopped in the swingback control is a position a little past the compression top dead center in the forward rotation direction. It becomes easier to get over the compression top dead center, and the startability of the engine is improved.

According to the seventh feature, since the straddle-type vehicle is provided with the engine starting device, it is possible to obtain a straddle-type vehicle provided with the engine starting device with excellent engine startability.

1 is a left side view of a motorcycle as a straddle-type vehicle according to an embodiment of the present invention; FIG. 1 is a block diagram showing the configuration of an engine control device; FIG. 4 is a graph showing the transition of the rotational speed of the crankshaft during reverse rotation driving of swingback control. 4 is a time chart showing the flow of swingback control according to the embodiment; 4 is a flowchart showing the procedure of engine start control according to the present embodiment;

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a left side view of a motorcycle 1 according to one embodiment of the invention. The motorcycle 1 is a scooter-type straddle-type vehicle provided with a low floor 24 between a steering handle 3 and a seat 22 on which the driver's feet are placed.

At the front end of the vehicle body frame F, a head pipe F1 is provided to rotatably support a steering stem 28. As shown in FIG. The vehicle body frame F includes a main frame F2 extending rearward and downward from the head pipe F1, a pair of left and right underframes F3 extending rearward and rearward of the vehicle body from the lower end of the main frame F2, and extending rearward and upward along with the underframes F3. and an extending rear frame F4.

A bottom bridge 26 that supports the front fork 10 that rotatably supports the front wheel WF on the front wheel axle FS is fixed to the lower end of the steering stem 28 . A steering handle 3 extending in the vehicle width direction is fixed to the upper end of the steering stem 28 . The front and rear of the steering handle 3 are covered with a handle cover 5 that supports the meter device. A front fender 9 is attached to the front fork 10 to cover the upper side of the front wheel WF.

A headlight 8 and a pair of left and right flasher lamps 27 are supported between a center cowl 6 disposed in front of a steering stem 28 and a pair of left and right front side cowls 7 in the vehicle width direction. . A floor panel 25 is connected to the rear of the front side cowl 7 so as to face the legs of the driver.

A lower front portion of the seat 22 is covered with a seat lower panel 23, and a rear cowl 20 is connected to the rear of the seat lower panel 23 to cover the left and right sides of the rear frame F4 in the vehicle width direction. At the rear end of the underframe F3, a unit-swing type power unit P integrating an engine E and a transmission is rotatably supported. A rear cushion 16 suspends the rear end of the power unit P, which rotatably supports the rear wheel WR on the rear wheel axle RS, from the rear frame F4. A crankshaft (crankshaft) C of the engine E is fixed with an ACG starter motor 50 that functions as a generator and a motor.

A center stand 13 is attached to the lower portion of the power unit P, and a kick starter 14 is attached to the left side surface of the power unit P in the vehicle width direction so that the power unit P can be started by the passenger's foot. An air cleaner box 19 is arranged above the power unit P. As shown in FIG.

Under cowls 11 are connected to the left and right sides of the low floor 24 in the vehicle width direction to cover the sides and bottom of the underframe F3. A side stand 12 supported by the underframe F3 is provided on the left side of the undercowl 11 in the vehicle width direction. A pillion step 21 supported by the rear frame F4 is provided in front of the air cleaner box 19. As shown in FIG. A rear grip 18 supported by the rear frame F<b>4 is arranged behind the seat 22 , and a tail light device 17 is arranged at the rear end portion of the rear cowl 20 . A rear fender 15 is provided below the taillight device 17 . An ECU 80 as an engine control device is arranged below the seat 22 .

FIG. 2 is a block diagram showing the configuration of the engine control device 100. As shown in FIG. The rotor position, that is, the crank angle of ACG starter motor 50 is detected by U-phase sensor 40U, V-phase sensor 40V and W-phase sensor 40W mounted on crank angle sensor 40 . The crank angle sensor 40 is also provided with a PCB sensor 40P that detects a singular point. Since the PCB sensor 40P detects the singular point, it can detect the compression top dead center and the exhaust top dead center.

The ECU 80 includes rotational speed calculation means 81 for calculating the rotational speed of the crankshaft C based on the output signal of the crank angle sensor 40 , ACG starter motor driving means 82 for controlling the ACG starter motor 50 , and the ACG starter motor 50 . A forward rotation/reverse determination section 83 for determining which state of forward rotation/reverse rotation is present is included. Electric power generated by ACG starter motor 50 is returned to battery B via ECU 80 . An output signal of a starter SW (switch) 92 is input to the ECU 80 . The ECU 80 controls the ACG starter motor 50 as well as the fuel injection device 90 and the ignition device 91 .

The crank angle sensor 40 according to this embodiment includes three sensor elements, and the rotational speed calculation means 81 calculates the rotational speed Ne twice or more during one rotation of the crankshaft C using the three sensor elements. This enables finer control with respect to changes in the rotation speed Ne.

When the engine E is started, the ECU 80 according to the present embodiment performs swing-back control to reverse drive the crankshaft C up to a predetermined range and then switch to forward rotation. Furthermore, when the rotation speed Ne of the crankshaft C exceeds the threshold value Ne1 during the reverse rotation driving of the swingback control, the driving duty of the PWM control is switched from 100% to 0%, and the rotation speed Ne of the crankshaft C is equal to or lower than the threshold value Ne1. When this occurs, the drive duty of the PWM control is alternately switched from 0% to 100%, and the drive of the motor is terminated when the compression reaction force pushes back. be.

FIG. 3 is a graph showing the transition of the rotation speed Ne of the crankshaft C during reverse drive of swingback control. When the crank angle r=0, reverse driving of the ACG starter motor 50 is started with a drive duty of 100%. Next, at the crank angle r1, the rotation speed Ne in the reverse rotation direction exceeds the upper limit set value for reverse rotation Ne1 (for example, 600 rpm) as a threshold. This reverse rotation upper limit set value Ne1 is set, for example, so that the crankshaft C does not go over compression top dead center due to reverse rotation.

The ECU 80 switches the drive duty from 100% to 0% when the rotational speed Ne exceeds the reverse rotation upper limit set value Ne1. As a result, the rotation speed Ne starts to decrease, and when the rotation speed Ne becomes equal to or lower than the reverse rotation upper limit set value Ne1, the drive duty is switched from 0% to 100%. By repeating this process, the ACG starter motor 50 can continue reverse rotation generally along the reverse rotation upper limit set value Ne1 by simple control based only on the output value of the crank angle sensor 40 . In addition, since the inertial force of the crankshaft C is large and a control delay occurs, the rotation speed Ne during the reverse rotation becomes like a line graph along the reverse rotation upper limit set value Ne1.

At the crank angle r2, it is detected that the crankshaft C has reached a predetermined range a little past the compression top dead center in the forward rotation direction by the generation of push-back reaction force, and the reverse rotation is stopped. Here, it is assumed that the push-back reaction force that suddenly increases as the compression top dead center approaches is generated when the ratio of the interval between the previous pulse and the current pulse of the crank angle sensor 40 is greater than a predetermined value. In the region where the push-back reaction force is generated, the crankshaft C does not move due to the relationship between the push-back reaction force and the force of the reverse drive. The ratio of the interval to the current pulse becomes larger than a predetermined value. Graph A indicated by a one-dot chain line indicates a case where startability deteriorates due to deterioration of the battery or the ACG starter motor 50, and graph B indicated by a two-dot chain line indicates a case where the start angle of reverse rotation is different.

FIG. 4 is a time chart showing the flow of swingback control according to this embodiment. This time chart shows, from the top, the rotational speed Ne of the crankshaft C, the drive instruction of the ACG starter motor 50, and the motor duty. In this embodiment, by limiting the motor duty to two patterns of 100% and 0%, it is possible to simplify the motor control and reduce the design burden and control burden.

At time t=0, the drive instruction for the ACG starter motor 50 is "stop", the rotational speed Ne is zero, and the motor duty is also zero. At time t1, the drive instruction is switched from "stop" to "reverse" in response to the ON operation of the starter switch 92, and the motor duty is switched to 100%.

At time t2, the rotation speed Ne in the reverse rotation direction exceeds the reverse rotation upper limit set value Ne1, so that the motor duty is switched to 0%. Next, at time t3, the motor duty is switched to 100% because the rotation speed Ne becomes equal to or lower than the reverse rotation upper limit set value Ne1.

At time t4, the drive instruction is switched from reverse rotation to forward rotation, and the motor duty is switched to 100% in the forward rotation direction. After that, at time t5, the rotation speed Ne exceeds the engine start determination set value Ne3 (for example, 1000 rpm), and the motor drive ends.

Note that switching control between 100% and 0% motor duty during motor driving can be performed not only during reverse rotation driving of swingback control, but also during forward rotation driving after reverse rotation driving. As a result, the ACG starter motor provides support until the engine is completely started in an unstable rotation state at low speeds where rotation fluctuations are likely to increase, and reliable engine start-up can be realized.

FIG. 5 is a flowchart showing the procedure of engine start control according to this embodiment. In step S1, it is determined whether or not the starter switch 92 has been turned on, and if an affirmative determination is made, the process proceeds to step S2. If a negative determination is made in step S1, the process returns to the determination in step S1.

If an affirmative determination is made in step S1, the starter relay is turned on in step S2. At step S3, the motor duty for driving the ACG starter motor 50 in the reverse direction is set to 100%. In step S4, a motor reverse drive command is output.

In step S5, it is determined whether or not the rotational speed Ne (reverse rotation Ne) exceeds the upper limit set value for reverse rotation Ne1. If the determination is affirmative, the motor duty is switched to 0% in step S6. , the motor duty of 100% is maintained in step S7.

In step S8, it is determined whether or not the compression top has been detected. More specifically, it is determined whether or not the position slightly advanced in the forward rotation direction from the top dead center of the compression stroke is within a predetermined range for terminating the reverse rotation.

In step S9, forward rotation driving is started with a motor duty of 100%. In step S10, a motor forward rotation drive command is output. In step S11, it is determined whether or not the rotation speed (forward rotation Ne) exceeds the forward rotation upper limit set value Ne2. If the determination is affirmative, the motor duty is switched to 0% in step S12, while the determination is negative. Then, the motor duty of 100% is maintained in step S13. The forward upper limit set value Ne2 for forward rotation must be set above the compression top dead center, so it can be set to a value equal to or slightly larger than the reverse upper limit set value Ne1 (for example, 600 rpm).

Then, in step S14, it is determined whether or not the rotational speed (forward rotation Ne) exceeds an engine start determination set value Ne3 (for example, 1000 rpm). , ends the sequence of controls. On the other hand, if a negative determination is made in step S14, the process returns to the determination of step S11.

As described above, according to the engine control device 100 according to the present embodiment, the ECU 80 executes swingback control for driving the crankshaft C in reverse to a predetermined range when the engine E is started. When the rotational speed Ne exceeds the threshold Ne1 during control, the ACG starter motor 50 is stopped (0% duty), and when the rotational speed Ne becomes equal to or less than the threshold Ne1 during swingback control, the ACG starter motor 50 is driven. (100% duty), the ACG starter motor 50 can be accurately stopped within a predetermined range by switching ON/OFF of the drive according to the rotational speed of the ACG starter motor during the reverse drive of the swingback control. becomes.

The form of the motorcycle, the form of the ACG starter motor and the crank angle sensor, the upper limit set value of the rotation speed, etc. are not limited to the above embodiment, and various modifications are possible. The engine starting device according to the present invention is not limited to motorcycles, and can be applied to straddle-type three-wheeled vehicles, four-wheeled vehicles, and the like.

DESCRIPTION OF SYMBOLS 1... Motorcycle 40... Crank angle sensor 50... ACG starter motor 80... ECU (control part) 81... Rotation speed calculation means 82... ACG starter motor drive means 83... Forward rotation/reverse rotation determination part 100... Engine starting device, E... Engine, C... Crankshaft, Ne... Rotational speed, Ne1... Upper limit set value for reverse rotation (threshold value), Ne2... Upper limit set value for forward rotation (threshold value), Ne3... Engine start completion threshold

Claims (7)

an ACG starter motor (50) that drives the crankshaft (C) of the engine (E) in the forward or reverse direction and generates electricity with the rotational force of the crankshaft (C);
a crank angle sensor (40) for detecting the rotation state of the crankshaft (C);
calculating the rotation speed (Ne) of the crankshaft (C) using the rotation state detected by the crank angle sensor (40);
In an engine starting device (100) comprising a control section (80) for controlling driving and power generation of the ACG starter motor (50),
When the engine (E) is started, the control unit (80) executes swing-back control to reversely drive the crankshaft (C) to a predetermined range,
The control unit (80) reduces the output of the ACG starter motor (50) when the rotation speed (Ne) exceeds a threshold value (Ne1) during the swingback control, and reduces the rotation speed during the swingback control. An engine starting device characterized by increasing the output of the ACG starter motor (50) when the speed (Ne) becomes equal to or less than a threshold value (Ne1). After the swing-back control, the control unit (80) drives the crankshaft (C) in the forward rotation direction until the engine (E) is completely started,
The control unit (80) stops driving the ACG starter motor (50) when the rotation speed (Ne) exceeds a threshold value (Ne2) during driving in the forward direction, and rotates the ACG starter motor (50) in the forward direction. 2. The engine starter according to claim 1, wherein the ACG starter motor (50) is driven when the rotational speed (Ne) becomes equal to or less than a threshold value (Ne2) during the driving of the engine. When the rotation speed (Ne) exceeds an engine start completion threshold (Ne3), the control unit (80) determines that the start of the engine (E) is complete, and stops driving the ACG starter motor (50). 3. The engine starting device according to claim 2, wherein: 4. The engine starter according to claim 3, wherein the detection of the predetermined range for stopping the reverse drive in the swingback control is performed by pushing back near the compression top dead center. The crank angle sensor (40) includes a plurality of sensor elements,
The control unit (80) includes rotation speed calculation means (81),
4. The rotation speed calculating means (81) uses the plurality of sensor elements to calculate the rotation speed (Ne) twice or more during one rotation of the crankshaft (C). 2. The engine starting device according to claim 1. 6. The engine starter according to claim 5, wherein the predetermined range in which the reverse drive is stopped in the swingback control is a position a little past the compression top dead center in the normal rotation direction. A straddle-type vehicle comprising the engine starting device according to any one of claims 1 to 6.

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