JP5838877B2 - Engine stop control device - Google Patents

Description

  The present invention relates to an engine stop control device.

  Conventionally, when the vehicle is temporarily stopped due to a signal or the like, the engine is temporarily stopped when a predetermined engine stop condition is satisfied, and then the engine is restarted according to the throttle operation at the time of restart (idling stop). Control is known.

  In this idle stop control, when the engine is temporarily stopped, it is preferable to arrange the crankshaft at a predetermined crank angle in order to improve startability at the time of restart.

  Therefore, the conventional engine start control device executes “rewind control” in which the motor is driven “after the engine is stopped” to reverse the crankshaft to a predetermined crank angle.

JP 2002-130095 A

  The conventional engine start control device executes “rewinding control” by reversing the crankshaft once stopped. Therefore, a motor that reverses the crankshaft to a predetermined crank angle must exhibit a corresponding torque in order to reverse the crankshaft that is stopped. Then, the power consumption of the motor will be required accordingly.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an engine stop control device capable of controlling the crank angle when the engine is stopped with lower torque and lower power consumption than in the prior art.

  In order to solve the above problems, an engine stop control device according to the present invention includes a motor connected to an engine crankshaft and capable of driving the crankshaft in a reverse direction, and the engine stop under a predetermined engine stop condition. After starting the control, when the crankshaft reaches the compression stroke and starts to reverse by the compression reaction force, the crankshaft is temporarily driven to assist the rotation of the crankshaft that is still in reverse rotation. And a control device that stops the engine in any one of an intake stroke, an exhaust stroke, and an explosion stroke.

  ADVANTAGE OF THE INVENTION According to this invention, the engine stop control apparatus which can control the crank angle at the time of an engine stop with low torque and low power consumption than before can be provided.

1 is a left side view showing a motorcycle to which an engine stop control device according to an embodiment of the present invention is applied. The block diagram which shows the control apparatus of the motorcycle which concerns on embodiment of this invention. The conceptual diagram which shows the stop process control which the stop control apparatus which concerns on embodiment of this invention performs. The flowchart which shows the stop process control function which the stop control apparatus which concerns on embodiment of this invention performs.

  An embodiment of an engine stop control device according to the present invention will be described with reference to FIGS.

  FIG. 1 is a left side view showing a motorcycle to which an engine stop control device according to an embodiment of the present invention is applied.

  In the present embodiment, front and rear, top and bottom, and left and right expressions are based on a rider who rides the motorcycle 1 and is a user of the motorcycle 1.

  As shown in FIG. 1, the motorcycle 1 according to this embodiment is a scooter type. The motorcycle 1 is a so-called underbone body frame 2, a front wheel 5 disposed in front of the body frame 2, and is supported to be swingable in the left-right direction with respect to the body frame 2 so that the front wheel 5 can rotate. A steering mechanism 6 to be supported, a rear wheel 7 disposed behind the vehicle body frame 2, a rear wheel 7 that is supported so as to be swingable in the vertical direction with respect to the vehicle body frame 2, and rotatably supports the engine 8; A power unit 11 integrally including a transmission device 9, a vehicle body cover 12 covering the vehicle body frame 2, and a seat 13 on which a rider can be seated are provided.

  The vehicle body frame 2 includes a plurality of steel hollow tubes combined together. Specifically, the vehicle body frame 2 includes a head pipe 15 disposed in the upper front portion, a down tube 16 connected to the head pipe 15, and a cross member 17 connected to the rear end portion of the down tube 16. A pair of left and right seat rails 18 connected to the vicinity of the left and right ends of the member 17.

  The head pipe 15 supports the steering mechanism 6 so as to be steerable in the left-right direction of the vehicle. The down tube 16 extends rearward from the front upper end connected to the head pipe 15 while being inclined downward and bent in an L-letter shape in a side view. The cross member 17 extends from the central portion connected to the down tube 16 in the left and right directions of the vehicle. The left and right seat rails 18 extend rearward and upward from the front lower end connected to the cross member 17, and include a front half portion having a large slope and a rear half portion having a small slope.

  The steering mechanism 6 includes an internal suspension mechanism (not shown), a pair of left and right front forks 19 that rotatably support the front wheels 5, a front fender 20 that covers the front wheels 5, and a top portion of the front forks 19. A pair of left and right handles 21 to be connected. The motorcycle 1 turns when the rider steers the handle 21 left and right. A handle 21 on the right side of the vehicle is an accelerator grip 21a.

  The power unit 11 also serves as a swing arm. Further, the power unit 11 is connected to the cross member 17 via the link member 22. The link member 22 supports the power unit 11 so as to be swingable with respect to the pivot shaft 23. The rear cushion unit 25 is installed between the power unit 11 and the vehicle body frame 2 that are separated from each other, and buffers the force transmitted from the rear wheel 7 to the vehicle body frame 2.

  The engine 8 is a small displacement of 50 cc class or 125 cc class, for example, a four-cycle internal combustion engine, and directs the center line of a cylinder (not shown) in the front-rear direction of the motorcycle 1.

  The intake system 26 is disposed above the power unit 11 and supplies an air-fuel mixture (fuel / air mixture) to the engine 8. The intake system 26 includes an air cleaner 27, an outlet pipe 28, a fuel injection device 29, and an intake pipe 31 in order from the upstream side.

  The rear wheel 7 obtains driving force from the engine 8 via the transmission device 9.

  The vehicle body cover 12 is a design surface that covers the vehicle body frame 2, and adjusts the appearance of the motorcycle 1. The vehicle body cover 12 includes a handle cover 33, a front leg shield 35, a footboard 36, a frame center cover 37, a frame side cover 38, and a frame lower cover 39, which are each made of synthetic resin and connected to each other.

  The front leg shield 35 faces the rear side of the seat 13 and shields the traveling wind to protect the rider's legs.

  The footboard 36 is a large cover connected to the front leg shield 35, the frame center cover 37, and the frame lower cover 39, and includes a footrest portion 41 on which a rider straddling the seat 13 bends a knee and places a foot.

  The frame side cover 38 has a pair of left and right, and covers each side surface below the seat 13.

  The frame lower cover 39 covers the lower part of the foot board 36.

  The seat 13 includes a front half portion 13a where a rider sits by bending a knee while keeping his feet and knees aligned with the footrest portion 41, and a rear half portion 13b where a passenger sits. Further, the seat 13 covers the upper portion of the storage box 42 and the fuel tank 43 and is connected to the frame side cover 38.

  The rear fender 45 extends rearward from the lower side of the fuel tank 43 and covers the upper side of the rear wheel 7.

  Next, the stop control device 51 of the engine 8 will be described in detail.

  FIG. 2 is a block diagram showing a motorcycle control apparatus according to an embodiment of the present invention.

  As shown in FIG. 2, the motorcycle 1 according to the present embodiment stops the engine 8 by shutting off the power supply and the ignition switch 53 that opens and closes with an ignition key (not shown) centered on the control device 52. A kill switch 55, a throttle position sensor 56 for measuring the opening of a throttle valve (not shown), a water temperature sensor 57 for measuring the coolant temperature of the engine 8, and a start command based on the start operation of the engine 8. A starter switch 58 for outputting and a brake switch 59 for detecting whether or not a brake (not shown) is operated are provided.

  The motorcycle 1 includes a crank angle sensor 62 that measures the crank angle of the crank shaft 61 of the engine 8, a vehicle speed sensor 63 that measures the angular speed of the rear wheel 7 with the transmission device 9, and a crank shaft 61 connected to the crank shaft 61. A starter motor 65 capable of driving the shaft 61 in the forward rotation direction and the reverse rotation direction, a starter motor power supply circuit 66 that supplies power to the starter motor 65 or shuts it off, and an ignition plug 67 that ignites the air-fuel mixture in the engine 8; A fuel injector 68 for supplying an air-fuel mixture to the engine 8 and a battery 69 are provided.

  The control device 52 includes a microcomputer and includes a central processing unit (not shown), a memory (not shown), and an I / O unit (not shown). The memory stores in advance data such as a control program executed by the central processing unit and constants necessary for executing the control program. The memory is used as a data storage area and a work area for temporarily storing calculation data of the central processing unit. The control device 52 has an idle stop control function for performing idle stop control as one of the control programs.

  The power supply of the control device 52 is performed directly from the battery 69 or indirectly from the battery 69 through the ignition switch 53 and the kill switch 55 in order. The control device 52 receives signals from a throttle position sensor 56, a water temperature sensor 57, a starter switch 58, a brake switch 59, a crank angle sensor 62, and a vehicle speed sensor 63. Further, the control device 52 outputs a control signal to the starter motor power circuit 66, the spark plug 67, and the fuel injection device 29 based on these power supply and input signals.

  The crank angle sensor 62 measures the crank angle by measuring the rotation of the crankshaft 61 and a camshaft (not shown) linked to the crankshaft 61, and the engine 8 is used for the compression stroke, the explosion stroke, the exhaust stroke, and the intake stroke. The process is detected and the measurement result and the detection result are output to the control device 52. The determination of which stroke the engine 8 is in may be made on the control device 52 side based on the measurement result of the crank angle.

  The starter motor power supply circuit 66 opens and closes an electric circuit that electrically connects the starter motor 65 and the battery 69 to supply power to the starter motor 65 or cut it off. The starter motor power circuit 66 is a switching circuit that drives the starter motor 65 in two directions so that the crankshaft 61 can be driven in the forward direction and the reverse direction.

  Since the starter motor 65 can be driven in two directions by the starter motor power supply circuit 66, the crankshaft 61 that is stopped can be normally rotated to start the engine 8, while the crankshaft 61 can be reversely rotated.

  The stop control device 51 includes a starter motor 65, a crank angle sensor 62, a starter motor power circuit 66, and a control device 52. The stop control device 51 controls the crank angle sensor 62, the starter motor 65, and the starter motor power supply circuit 66 when the control device 52 performs the idle stop control, thereby assisting the reverse rotation of the crankshaft 61 to operate the engine 8. Always stop at any one of the intake stroke, exhaust stroke, and explosion stroke (that is, the stroke other than the compression stroke). This series of controls performed by the stop control device 51 is referred to as “stop stroke control”. The stop stroke control may be a part of the idle stop control or may be a separate function that cooperates with the idle stop control. The stop stroke control is incorporated in the control device 52 as a stop stroke control function.

  That is, the stop control device 51 includes a starter motor 65 connected to the crankshaft 61 of the engine 8, a crank angle sensor 62 that measures the crank angle of the crankshaft 61, and a starter that supplies power to or shuts off the starter motor 65. After starting the stop control of the engine 8 under the motor power supply circuit 66 and a predetermined engine stop condition, when the crankshaft 61 that has reached the compression stroke starts to reverse due to the compression reaction force, the starter motor 65 is temporarily driven. And a control device 52 that stops the crankshaft 61 in any one of an intake stroke, an exhaust stroke, and an explosion stroke by assisting the rotation of the crankshaft 61 that is still in reverse rotation.

  Next, stop stroke control performed by the stop control device 51 will be described.

  FIG. 3 is a conceptual diagram showing stop stroke control performed by the stop control device according to the embodiment of the present invention.

  As shown in FIG. 3, the engine 8 according to the present embodiment sucks an air-fuel mixture into a cylinder (not shown), compresses the air-fuel mixture, ignites and explodes the compressed air-fuel mixture, and generates combustion gas. A series of operations (cycles) until exhaust is a four-stroke engine in which a piston (not shown) is raised and lowered twice, that is, the crankshaft 61 is rotated twice during one cycle.

  In the stop stroke control, after the control device 52 starts the idle stop control under a predetermined engine stop condition, the change in the crank angle θ of the crankshaft 61 or the angular velocity ω of the crankshaft 61 is monitored. At this time, the stop stroke control determines whether the crankshaft 61 is rotating forward or reversely from the crank angle θ or the angular velocity ω.

  The crankshaft 61 in the stop process is gradually decelerated or braked by a compression reaction force applied to the piston and various losses each time it reaches the compression stroke, while rotating forward by inertia (line a in FIG. 3). ) And finally starts to reverse due to the compression reaction force in the compression stroke (line b in FIG. 3).

  At this time, the stop stroke control detects the start of reverse rotation of the crankshaft 61. Based on this detection result, the stop stroke control temporarily drives the starter motor 65 to assist the rotation of the crankshaft 61 that is rotating in reverse (line c in FIG. 3).

  In the stop stroke control, when the starter motor 65 is temporarily driven, the crankshaft 61 is released from the compression stroke, and can be returned to any one of the intake stroke, the exhaust stroke, and the explosion stroke (section A in FIG. 3). The rotation of the crankshaft 61 is assisted until the angular velocity is equal to or higher than the angular velocity α1 and smaller than the angular velocity α2 overcoming the compression top dead center (line c in FIG. 3).

  Note that the magnitude relationship between the angular velocities ω, α1, and α2 focuses on the magnitude of the absolute value for simplicity of explanation, and the same applies to the following.

  The reverse rotation assistance of the crankshaft 61 is achieved by the angular velocity ω of the crankshaft 61 being greater than or equal to an angular velocity α1 that can be returned to any one of the intake stroke, exhaust stroke, and explosion stroke (section A in FIG. 3), and compression top dead center. Therefore, the angular velocity ω may be accelerated, maintained, or moderated (reduced negative angular acceleration). In order to assist reverse rotation of the crankshaft 61, the starter motor 65 may be temporarily driven a plurality of times. This reverse assist control of the crankshaft 61 is based on a change per unit time in the crank angle measured by the crank angle sensor 62.

  The crankshaft 61 assisted in reverse rotation in this way returns at least to the intake stroke. Then, after returning to the intake stroke, the crankshaft 61 stops at the crank angle of any one of the intake stroke, the exhaust stroke, and the explosion stroke by the inertial force acting in the reverse direction (in FIG. 3, a line segment d). ). From the viewpoint of restarting the engine 8, it is preferable that the crank angle at which the crankshaft 61 is stopped reach the exhaust stroke or the explosion stroke.

  The stop stroke control is repeatedly performed at every cycle of the engine 8 during the idle stop control period. Further, in the stop stroke control, when the crankshaft 61 that normally rotates in the stop process loses the angular velocity and cannot reach the compression stroke, the starter motor 65 is temporarily driven and the crankshaft 61 that is still rotating forward is still being driven. Assisting the rotation of the cylinder to reach the compression stroke.

  The stop stroke control will be further described.

  FIG. 4 is a flowchart showing a stop stroke control function performed by the stop control device according to the embodiment of the present invention.

  As shown in FIG. 4, the control device 52 of the stop control device 51 according to the present embodiment determines whether or not the crankshaft 61 is reversely rotated by a change in the crank angle θ acquired from the crank angle sensor 62.

  In addition, the control device 52 assists the rotation of the crankshaft 61 that is rotating in reverse until the starter motor 65 is temporarily driven until the angular velocity becomes higher than the angular velocity that can be returned to the exhaust stroke.

  Further, the control device 52 assists the rotation of the crankshaft 61 during the reverse rotation until the angular velocity is smaller than the angular velocity overcoming the compression top dead center by temporarily driving the starter motor 65.

  The stop stroke control function by the control device 52 will be specifically described in detail.

  In order to simplify the following description, when the piston is at the compression top dead center, the crank angle is 0 degree as a reference, and a section greater than 0 degree and below the next bottom dead center (crank angle 180 degrees) is defined. In the compression stroke, the section greater than 180 degrees and below the top dead center (crank angle 360 degrees) is the exhaust stroke, and the section greater than 360 degrees and below the next bottom dead center (crank angle 540 degrees) is the intake stroke from 540 degrees. A section that is largely below the bottom dead center (crank angle 720 degrees) is defined as a compression stroke. Further, when the crankshaft 61 rotates twice and the crank angle reaches 720 degrees, that is, when the piston reaches the compression top dead center again, the crank angle is returned to 0 degrees.

  First, the control device 52 starts idling stop control when a predetermined engine stop condition is satisfied after the motorcycle 1 temporarily stops due to a signal or the like. At this time, the stop control device 51 starts stop stroke control. The stop control device 51 stores reverse rotation assist OFF information prior to the start of stop stroke control.

  Then, when the stop stroke control is started, in step S1, the control device 52 determines whether or not reverse rotation assist OFF information is stored. If the reverse rotation assist OFF information is stored, the control device 52 advances the control to step S2. Otherwise, the control device 52 advances the control to step S4. When the control device 52 repeatedly performs the stop stroke control until the crankshaft 61 stops, it is determined whether or not the crankshaft 61 has already started reverse rotation at the (n-1) th time when starting the nth stop stroke control. Check in.

  In step S2, the control device 52 determines whether or not the crankshaft 61 is reversely rotated. Specifically, the control device 52 monitors whether the current angular velocity ω of the crankshaft 61 is a negative value or whether the measurement result of the crank angle sensor 62 is moving backward. It is determined whether the shaft 61 is reversed. If the crankshaft 61 is moving backward, the control device 52 advances the control to step S3. Otherwise, the control device 52 advances the control to step S6. Note that the control device 52 sequentially acquires the measurement results of the crank angle sensor 62 in order to calculate the current angular velocity ω of the crankshaft 61.

  In step S3, the control device 52 stores information indicating that it is necessary to assist the reverse rotation of the crankshaft 61 (reverse rotation assist ON information), and the control proceeds to step S6.

  On the other hand, in step S4, the control device 52 acquires the current crank angle θ from the crank angle sensor 62, and determines whether or not the acquired crank angle θ is greater than 0 degree and less than or equal to 540 degrees (that is, It is determined whether the crankshaft 61 is out of the compression stroke and is in any one of the intake stroke, the exhaust stroke, and the explosion stroke). If the crank angle θ is greater than 0 degree and less than or equal to 540 degrees, the control device 52 advances the control to step S5. Otherwise, the control device 52 advances the control to step S6.

  In step S5, the control device 52 stores information indicating that it is not necessary to assist the reverse rotation of the crankshaft 61 (reverse rotation assist OFF information), and the control proceeds to step S6.

  Next, in step S <b> 6, the control device 52 determines whether to start the starter motor 65. Specifically, the control device 52 calculates the current angular speed ω of the crankshaft 61, and the calculated current angular speed ω of the crankshaft 61 deviates from the compression stroke, and any one of the intake stroke, the exhaust stroke, and the explosion stroke. It is determined whether or not the angular velocity α1 is greater than or equal to the angular velocity α1 that can be returned to the stroke and is smaller than the angular velocity α2 that exceeds the compression top dead center, and whether or not the reverse rotation assist ON information is stored. If the angular velocity ω of the crankshaft 61 is not less than the angular velocity α1 and smaller than the angular velocity α2 and the reverse rotation assist ON information is stored, the control device 52 advances the control to step S7. Otherwise, the control device 52 advances the control to step S8.

  In step S <b> 7, the control device 52 closes the starter motor power circuit 66 and drives the starter motor 65 to finish the stop process control.

  In step S <b> 8, the control device 52 opens the starter motor power supply circuit 66 to cut off the power supply to the starter motor 65 and ends the stop stroke control.

  The stop control device 51 can arbitrarily adjust the crank angle at which the crankshaft 61 stops by appropriately adjusting the angular velocity α2 that limits the upper limit of the angular velocity of the crankshaft 61 during reverse rotation.

  The stop control device 51 of the engine 8 according to the present embodiment does not perform “rewinding control” by reversing the crankshaft 61 once stopped, unlike the conventional engine start control device, but the crankshaft that is still in reverse rotation. By assisting the rotation of 61 with the starter motor 65, the engine 8 can be stopped in any one of the intake stroke, the exhaust stroke, and the explosion stroke other than the compression stroke. This reverse rotation assist of the crankshaft 61 can be performed with a smaller torque than when the stopped crankshaft 61 is reversely rotated, so that the power consumption required for the reverse rotation of the starter motor 65 can also be suppressed.

  Further, the stop control device 51 for the engine 8 according to the present embodiment places the crankshaft 61 in any one of the intake stroke, the exhaust stroke, and the explosion stroke other than the compression stroke when the engine 8 is stopped. Therefore, the angular velocity ω of the crankshaft 61 can be sufficiently accelerated before the air-fuel mixture is compressed in the compression stroke at the time of restart in the idle stop control. In other words, the stop control device 51 of the engine 8 uses the section from the stop position (stop crank angle) of the crankshaft 61 to the compression stroke as a running section of the crankshaft 61, and the startability when the engine 8 is restarted. Can be improved.

  Further, the stop control device 51 of the engine 8 according to the present embodiment ensures that the crankshaft 61 reaches the outside of the compression stroke by assisting the reverse rotation of the crankshaft 61 until the angular velocity α1 that can be returned to the exhaust stroke becomes equal to or higher. be able to.

  Furthermore, the stop control device 51 of the engine 8 according to the present embodiment more reliably compresses the crankshaft 61 by assisting the reverse rotation of the crankshaft 61 until the angular velocity is smaller than the angular velocity α2 that exceeds the compression top dead center. You can reach out of the process.

  Therefore, according to the stop control device 51 for the engine 8 according to the present embodiment, the crank angle when the engine is stopped can be controlled with lower torque and lower power consumption than in the prior art.

  The stop control device 51 is not limited to the engine 8 of the scooter type motorcycle 1 but may be a super sport or an off-road type.

DESCRIPTION OF SYMBOLS 1 Motorcycle 2 Body frame 5 Front wheel 6 Steering mechanism 7 Rear wheel 8 Engine 9 Transmission device 11 Power unit 12 Car body cover 13 Seat 13a Front half 13b Rear half 15 Head pipe 16 Down tube 17 Cross member 18 Seat rail 19 Front fork 20 Front fender 21 Handle 21a Accelerator grip 22 Link member 23 Pivot shaft 25 Rear cushion unit 26 Intake system 27 Air cleaner 28 Outlet pipe 29 Fuel injection device 31 Intake pipe 33 Handle cover 35 Front leg shield 36 Footboard 37 Frame center cover 38 Frame side cover 39 Frame Lower cover 41 Footrest part 42 Storage box 43 Fuel tank 45 Rear fender 51 Stop control device 52 Control device 53 Ignition Down switch 55 kill switch 56 throttle position sensor 57 water temperature sensor 58 starter switch 59 brake switch 61 crankshaft 62 crank angle sensor 63 vehicle speed sensor 65 starter motor 66 starter motor power supply circuit 67 spark plug 68 fuel injector 69 Battery

Claims (4)

A motor connected to the crankshaft of the engine and capable of driving the crankshaft in the reverse direction;
After the engine stop control is started under a predetermined engine stop condition, when the crankshaft reaches the compression stroke and starts reverse rotation by the compression reaction force, the motor is temporarily driven to rotate the crank that is still in reverse rotation. An engine stop control device comprising: a control device that stops the crankshaft in any one of an intake stroke, an exhaust stroke, and an explosion stroke by assisting rotation of the shaft. A crank angle sensor for measuring a crank angle of the crankshaft;
2. The engine stop control device according to claim 1, wherein the control device determines whether or not the crankshaft is reversely rotated based on a change in the crank angle acquired from the crank angle sensor. 3. The engine according to claim 1, wherein the control device assists the rotation of the crankshaft that is reversely rotated until the angular velocity at which the motor can be returned to the exhaust stroke becomes equal to or higher than the angular velocity by the temporary drive of the motor. Stop control device. The said control apparatus assists rotation of the said crankshaft reversely rotated until it becomes an angular velocity smaller than the angular velocity overcoming a compression top dead center by the temporary drive of the said motor. The engine stop control device according to claim 1.

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