Vehicular control device, control method and straddle type vehicle

Abstract

To provide a technique for improving restartability after automatic stop of an engine.SOLUTION: A vehicular control device includes assisting control means for executing normal assisting control for driving an electric motor capable of assisting starting of an engine mounted to a vehicle until speed of the engine reaches first prescribed speed at start of the engine. The engine is automatically stopped when an idling stop condition is satisfied, and is restarted when a restarting condition is satisfied. At restart of the engine, the assisting control means can execute restart assisting control for driving the electric motor until the speed of the engine reaches second prescribed speed higher than the first prescribed speed.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device, a control method, and a straddle-type vehicle. [Background technology]

[0002] In recent years, research and development has been conducted to contribute to energy efficiency in order to ensure access to sustainable and advanced energy. As part of this research and development, vehicles equipped with an idle stop function have been proposed from the perspective of environmental considerations and energy conservation. Such vehicles are advantageous in terms of improving fuel efficiency because the engine automatically stops when the vehicle is stopped temporarily at a traffic light, and can contribute to the effective use of limited resources. It is desirable that the engine be restarted smoothly after automatically stopping so that the vehicle can be started quickly. Patent Documents 1 and 2 propose technologies for improving restartability by performing position control to stop the crankshaft, which rotates by inertia, at a position where it is easy to restart the engine when the engine is automatically stopped. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6070669 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-120373 Summary of the Invention [Problem to be solved by the invention]

[0004] After the engine automatically stops, it may be necessary to immediately restart it. If a restart is requested before the crankshaft position control disclosed in Patent Document 1 or Patent Document 2 is completed, the request may not be immediately accepted.

[0005] An object of the present invention is to provide a technique for improving the restartability of an engine after it has been automatically stopped. [Means for solving the problem]

[0006] According to the present invention, A vehicle control device (10) including an auxiliary control means (11) that performs normal auxiliary control to drive an electric motor (34) capable of assisting the start of an engine (30) mounted on a vehicle (100) until the engine (30) reaches a first specified rotation speed (NL) when the engine (30) is started, the engine (30) is automatically stopped when an idle stop condition is satisfied, and is restarted when a restart condition is satisfied; The auxiliary control means (11) When restarting the engine (30), a restart assist control can be executed to drive the electric motor (34) until the engine (30) reaches a second specified rotation speed (NH) higher than the first specified rotation speed (NL). A vehicle control device is provided. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technique for improving the restartability of an engine after it has been automatically stopped. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a left side view of a saddle-ride type vehicle according to an embodiment of the present invention; [Figure 2] FIG. 2 is a block diagram of a control device, a drive system, and an operating system of the saddle-ride type vehicle of FIG. 1. [Figure 3] (A) and (B) are explanatory diagrams of the operation of the decompression mechanism. [Figure 4] 10 is a flowchart showing an example of processing executed by a processing unit. [Figure 5] 10 is a flowchart showing an example of processing executed by a processing unit. [Figure 6] 4 is a timing chart showing an example of transitions of the crank angle, engine speed, and control state during stop position control. [Figure 7]4 is a timing chart showing an example of transitions of the engine speed and the driving state of the electric motor relative to the crank angle during pre-brake control. [Figure 8] 10 is a flowchart showing an example of processing executed by a processing unit. [Figure 9] 10 is a flowchart showing an example of processing executed by a processing unit. [Figure 10] 10 is a flowchart showing an example of processing executed by a processing unit. [Figure 11] 10 is a flowchart showing an example of processing executed by a processing unit. [Figure 12] 6A to 6C are flowcharts showing examples of processing executed by a processing unit. [Figure 13] 10 is a flowchart showing an example of processing executed by a processing unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be omitted.

[0010] <Overview of saddle-type vehicle> Fig. 1 is a left side view of a saddle-ride type vehicle (hereinafter also simply referred to as a vehicle) 100 according to one embodiment of the present invention. In Fig. 1, arrow D1 indicates the longitudinal direction of vehicle 100, with F indicating the front side and B indicating the rear side. Arrow D2 indicates the width direction of vehicle 100, with L indicating the left side and R indicating the right side when viewed in the forward direction of vehicle 100. The D1 and D2 directions are horizontal directions. Arrow D3 indicates the vertical direction of vehicle 100, with U indicating the upper side and D indicating the lower side.

[0011] Vehicle 100 is a scooter-type motorcycle that has a step floor 108 on which the rider's legs rest, provided between steering handlebars 102 and a seat 109 on which the rider sits. However, the present invention is also applicable to other types of saddle-ride type vehicles.

[0012] A head pipe 104 is fixed to the front end of the body frame 101. The head pipe 104 rotatably supports a steering stem 103 extending downward from a steering handlebar 102. A pair of left and right front forks 105 that rotatably support a front wheel 110 are fixed to the lower part of the steering stem 103. A front wheel brake 118 that brakes the front wheel 110 is supported on the pair of front forks 105. The front wheel brake 118 is, for example, a disc brake device.

[0013] A front handle cowl 113 supporting a headlight 111 and a meter device 114 is provided in front of the steering handle 102. A rear handle cowl 115 is provided behind the steering handle 102. The meter device 114 displays various information such as vehicle speed and remaining fuel. The head pipe 104 and steering stem 103 are covered with a cover 116. A front combination lamp 107 is provided at the front of the vehicle 100.

[0014] A swing-type power unit 106 is pivotally supported behind the step floor 108 so that it can swing freely. Rear wheels 112, which are drive wheels, are pivotally supported on the power unit 106 so that the power unit 106 rotates the rear wheels 112. The rear end of the power unit 106 is suspended from the vehicle body by a rear cushion 117. A rear wheel brake 119 that brakes the rear wheels 112 is also supported on the power unit 106. The rear wheel brake 119 is, for example, a drum-type brake device.

[0015] 2 is a block diagram of the control device 10, drive system, and operation system of the saddle-ride type vehicle 100. The power unit 106 includes a transmission 35 and a centrifugal clutch 36 provided in a drive transmission path between the engine 30 and the rear wheel 112. The transmission 35 of this embodiment is a continuously variable transmission that combines a belt and two variable diameter pulleys, and receives driving force from the crankshaft 30a of the engine 30 and outputs the driving force to the centrifugal clutch 36. The centrifugal clutch 36 transmits and cuts off the driving force output from the transmission 35 to the rear wheel 112. The centrifugal clutch 36 enters a transmitting state due to the action of centrifugal force as the rotation speed of the output shaft of the transmission 35 increases, and enters a transmission cut-off state when the rotation speed of the output shaft of the transmission 35 is low.

[0016] In this embodiment, the engine 30 is a single-cylinder, four-stroke, DOHC engine, and is equipped with a throttle 31 that adjusts the amount of intake air, a fuel injection device (injector) 32 that injects fuel, and an ignition device 33 that ignites the air-fuel mixture in the combustion chamber. The electric motor 34 is connected to a crankshaft 30a of the engine 30. The electric motor 34 functions as a starter that starts the engine 30, and also functions as an alternator that is driven by the engine 30 to generate electricity.

[0017] The throttle grip 41 is a throttle operator that is operable by the rider and allows the rider to adjust the opening of the throttle 31. The throttle grip 41 is rotatably mounted on the right steering handlebar 102. In the present embodiment, the throttle grip 41 and the throttle 31 are physically connected by a mechanical wire. However, a throttle-by-wire system may be adopted in which the throttle grip 41 and the throttle 31 are not physically connected and the rider's throttle operation (accelerator operation) is converted into an electrical signal to control the throttle.

[0018] The brake lever 42 is a brake operator that is operable by the rider and can operate a front wheel brake 118 that applies a braking force to the front wheel 110 of the vehicle 100. The brake lever 42 is disposed in front of the throttle grip 41. When the rider operates the brake lever 42 with his / her right hand, the front wheel brake 118 provided on the front wheel 110 is operated, and a braking force is applied to the front wheel 110.

[0019] The brake lever 43 is a brake operator that is operable by the rider and can operate a rear wheel brake 119 that applies a braking force to the rear wheel 112 of the vehicle 100. The brake lever 43 is disposed in front of the left traveling handlebar 102. When the rider operates the brake lever 43 with his / her left hand, the rear wheel brake 119 that is provided on the rear wheel 112 is operated, and a braking force is applied to the rear wheel 112.

[0020] The vehicle 100 includes a control device 10. The control device 10 is an electric circuit including a processing unit 11 represented by a CPU, a storage unit 12 such as a semiconductor memory, and an input / output interface (I / O) 13 with an external device. The control device 10 also includes a circuit for processing sensor signals and a circuit for driving actuators. The processing unit 11 can also be called a control unit because it executes control processing for the vehicle 100. The storage unit 12 stores programs executed by the processing unit 11 and data used in processing by the processing unit 11 (for example, target transition information Tne, described later). A plurality of processing units 11 and a plurality of storage units 12 may be provided. For example, an electric circuit including a processing unit and a storage unit that control the automatic stop and restart of the engine 30, described later, and an electric circuit including a processing unit and a storage unit that control the electric motor 34 may be provided separately.

[0021] The control device 10 acquires the detection results of the various sensors 21 to 23 and controls the engine 30 and the electric motor 34. The throttle operation sensor 21 is a sensor that detects the rider's operation of the throttle grip 41. The throttle operation sensor 21 may be a sensor that is provided on the throttle grip 41 and detects the amount of rotation of the throttle grip 41, or a sensor that is provided on the throttle 31 and detects the throttle opening.

[0022] The crank angle sensor 22 is a sensor that detects the amount of rotation of the crankshaft 30a of the engine 30. The detection result of the crank angle sensor 22 can identify the position (rotational position) of the crankshaft 30a and the rotation speed of the engine 30 (i.e., the rotation speed of the crankshaft 30a). The rotational position of the crankshaft 30a may be expressed as θ. The engine 30 is a four-stroke engine, and the crankshaft 30a rotates twice in four strokes. Therefore, θ takes a value in the range of 0 degrees to 720 degrees, and the compression top dead center is 0 degrees. The rotation speed of the engine 30 may also be expressed as NE. The unit is rpm. The vehicle speed sensor 23 is a sensor that detects the speed of the vehicle 10, and is a sensor that detects the amount of rotation of the front wheels 110, for example.

[0023] The starter switch 24 is a switch used by the rider to instruct the start of the engine 30. When the rider turns on the starter switch 24 while a power switch (not shown) is on, the control device 10 accepts this as a start operation and starts the engine 30. Note that the starter switch 24 may be provided integrally with the power switch, and in this case, the switching positions of the power switch may include ACC ON (power ON), ignition ON (start operation), and OFF (power OFF).

[0024] <Decompression mechanism> The engine 30 is provided with a decompression mechanism. As an example, Figures 3(A) and 3(B) are explanatory diagrams of the operation of a decompression mechanism 90. The decompression mechanism 90 is a mechanism that opens the valves of the engine 30 to reduce compression torque when the engine 30 is started, and the decompression mechanism 90 of this embodiment is a centrifugal automatic decompression mechanism that opens the exhaust valves (not shown) of the engine 30.

[0025] The decompression mechanism 90 includes a decompression cam 91 provided on the side of the exhaust cam 46, a decompression weight 92 that rotates the decompression cam 91 from a decompression operating state to a decompression inactive state by centrifugal force according to the rotational speed of the camshaft 44 of the exhaust cam 46, and a torsion coil spring 94 that urges the decompression weight 92 in the closing direction toward the camshaft 44.

[0026] The decompression cam 91 is supported so as to be rotatable about a rotation center shaft 90a. The decompression cam 91 has a groove 91a into which an operating pin 92a provided in a decompression weight 92 is inserted.

[0027] The decompression weight 92 is supported so as to be able to swing freely on a decompression pin 93 that protrudes from the side of the exhaust cam 46 and is parallel to the camshaft 44. The decompression weight 92 has a curved shape so as to surround the camshaft 44. An operating pin 92a is provided at one end of the decompression weight 92. The operating pin 92a is slidable in a groove portion 91a, and the decompression cam 91 can be rotated by displacement of the operating pin 92a.

[0028] The torsion coil spring 94 is wound multiple times around the decompression pin 93. The torsion coil spring 94 is then wound around the camshaft 44, with one end of the spring being fixed to the side of the exhaust cam 46. The other end of the torsion coil spring 94 is engaged in a hole 92b formed in the decompression weight 92. The torsion coil spring 94 constantly urges the decompression weight 92 in a direction approaching the camshaft 44.

[0029] The decompression mechanism 90 configured as described above is in a decompression operating state as shown in FIG. 3A when the engine 30 starts and the rotation speed of the rotating camshaft 44 is equal to or lower than a predetermined rotation speed. In other words, the centrifugal force generated in the decompression weight 92 is smaller than the biasing force of the torsion coil spring 94, and the decompression weight 92 oscillates only slightly. A portion of the cam surface of the decompression cam 91 protrudes outward from the outer circumferential surface of the base circular portion of the exhaust cam 46. During the rotation of the exhaust cam 46, when a portion of the cam surface of the decompression cam 91 faces the decompression cam abutment portion 57b of the exhaust-side rocker arm 57, the decompression cam 91 pushes up the decompression cam abutment portion 57b of the rocker arm 57. As a result, the rocker arm 57 rotates about the rocker arm shaft 57a and pushes down the exhaust valve. As a result, even when the engine 30 is in the compression stroke, the exhaust valve is opened, and the function of reducing the compression torque of the engine 30 is activated, thereby improving the startability of the engine 30.

[0030] When the rotation speed of the engine 30 increases and the rotation speed of the rotating camshaft 44 exceeds a predetermined rotation speed, the centrifugal force acting on the decompression weight 92 becomes greater than the biasing force of the torsion coil spring 94, causing the decompression weight 92 to swing in a direction away from the camshaft 44. This causes the operating pin 92a to move within the groove 91a of the decompression cam 91, causing the decompression cam 91 to rotate. When the decompression cam 91 rotates, as shown in FIG. 3(B), the decompression cam abutment portion 57b of the rocker arm 57 no longer contacts the decompression cam 91, and the roller 57c of the rocker arm 57 abuts against the outer peripheral surface of the exhaust cam 46. The rocker arm 57 moves in accordance with the shape of the outer peripheral surface of the exhaust cam 46, causing the decompression mechanism 90 to enter a decompression inoperative state, and the function of reducing the compression torque of the engine 30 no longer works.

[0031] In this way, the operating state of the decompression mechanism 90 changes depending on the rotational speed of the engine 30. The upper limit rotational speed of the engine 30 at which the decompression mechanism 90 can reliably reduce the compression torque of the engine 30 is called the decompression operating speed. The decompression operating speed is, for example, 800 rpm.

[0032] <Processing example> A description will be given of an example of processing executed by the control device 10. The processing unit 11 repeatedly executes each of the processes described below at predetermined intervals (for example, every few msec).

[0033] <Status data update process> 4 is a flowchart showing an example of a status data update process, in which various status data are updated based on the detection results of the sensors 21-24.

[0034] In S1, the detection results of the sensors 21 to 24 are acquired. In S2, each state data stored in the storage unit 12 is updated based on the detection results acquired in S1. Types of state data to be updated include, for example, the throttle state (e.g., closed or open state) based on the detection results of the throttle operation sensor 21, θ and NE based on the detection results of the crank angle sensor 22, the vehicle speed based on the detection results of the vehicle speed sensor 23, and the rider's starting operation based on the detection results of the starter switch 24.

[0035] <Normal start control> Normal start control is executed when the power supply to the vehicle 100 is ON, waits for a start operation by the rider on the starter switch 24, and starts the engine 30 based on the start operation. Normal start control is a basic start control for the rider to start the engine 30 when riding the vehicle 100, and is control in which the rider turns on the power supply and turns on the starter switch 24 to start the engine 40. When a start operation is performed, the engine 30 is started while the electric motor 34 is driven as a starter.

[0036] <Idle stop / restart control> 5 is a flowchart showing an example of processing related to idle stop control. The control device 10 performs idle stop control of the engine 30. In idle stop control, the engine 30 is automatically stopped when it is estimated that the vehicle 100 will stop temporarily, and after the automatic stop, the engine 30 is restarted when it is estimated that the vehicle 100 will start moving.

[0037] In the following description, the IS flag is a flag in which ON and OFF information is stored using a predetermined storage area in the storage unit 12 of the control device 10. The IS flag is a flag that indicates whether or not the engine is in an idle stop state, and is switched to ON during an idle stop state and to OFF during other than an idle stop state.

[0038] Here, a predetermined position of the crankshaft 30a that allows the engine 30 to be restarted more smoothly will be described. When starting the engine 30, the rotational load is greatest when the piston passes over the compression top dead center during forward rotation of the crankshaft 30a. Therefore, when stopping the engine 30, the crankshaft 30a is positioned at a predetermined position (for example, a position within 30 degrees after the compression top dead center; position P, described below). This position is called the start preparation position. If the engine 30 is then started, the running period until the piston reaches the compression top dead center can be lengthened, and the rotational speed of the crankshaft 30a when the piston reaches the compression top dead center can be increased. As a result, the startability of the engine 30 can be improved.

[0039] Referring to Figure 5, in S11, it is determined whether or not the IS flag is ON. If it is OFF, the process proceeds to S12, and if it is ON, the engine is currently in idle stop mode, so the process proceeds to S16. In S12, it is determined whether or not the idle stop conditions are met based on the status data. If it is determined that the idle stop conditions are met, the process proceeds to S13, and if it is determined that the idle stop conditions are not met, the process ends.

[0040] The idle stop condition may be, for example, that the vehicle speed is equal to or less than a specified speed (for example, 3 km / h) and that the throttle 31 is closed for a specified time (for example, 3 seconds). Other conditions may include that the headlights 36 are turned off or that the rider has previously permitted the execution of idle stop control (that is, that an idle stop switch is provided and the rider has turned it ON).

[0041] In this embodiment, the idle stop condition is a condition that can be met while the vehicle 100 is traveling, and does not require the vehicle 100 to be stopped (such as the vehicle speed being 0 for a certain period of time). As a result, the engine 30 automatically stops while the vehicle 100 decelerates and stops, thereby improving fuel efficiency compared to when the vehicle 100 must be stopped.

[0042] In S13, automatic stop control is executed to automatically stop the engine 30. For example, the engine 30 can be stopped by cutting off the supply of fuel by the fuel injection device 32 or by stopping ignition by the ignition device 33. In S14, the IS flag is set to ON. In S15, stop position control is executed to position the crankshaft 30a of the engine 30 at a start preparation position. Details will be described later.

[0043] S16 to S18 are processes performed during an idle stop of the engine 30. In S16, it is determined whether or not a restart condition is met. An example of the restart condition is when the rider opens the throttle 31 (rotates the throttle grip 41). If it is determined that the restart condition is met, the process proceeds to S17, and if it is determined that the restart condition is not met, the process ends.

[0044] In S17, restart control is executed. The electric motor 34 is driven as a starter to rotate the crankshaft 30a in the forward direction, while the fuel injection device 32 supplies fuel and the ignition device 33 ignites it to drive the engine 30. The restart control will be described later. In S18, the IS flag is set to OFF.

[0045] <Stop position control> The stop position control in S15 of Fig. 5 will now be described in detail. Fig. 6 is a timing chart showing an example of transitions of the crank angle θ, engine speed NE, and control state CNT during stop position control. The horizontal axis represents time. Regarding the control state CNT, IS indicates the execution interval of the automatic stop control (S13), PB indicates the execution interval of the pre-brake control, and MB indicates the execution interval of the main brake control.

[0046] In the stop position control of this embodiment, after the automatic stop control (S13), the crankshaft 30a rotating by inertia is stopped within the range of the start preparation position P by the driving force of the electric motor 34. The electric motor 34 is rotated in a direction that reverses the forward rotating crankshaft 30a, thereby braking the crankshaft 30a.

[0047] The main brake control is a control that drives the electric motor 34 when the crankshaft 30a reaches a braking start position θs that is close to the start preparation position P, thereby stopping the crankshaft 30a at the start preparation position P. There is variation in the reduction in the rotational speed of the crankshaft 30a that rotates by inertia after the automatic stop. For this reason, even if the main brake control is started at the same θs, there may be cases where the crankshaft 30a cannot be stopped at the start preparation position P. Therefore, in this embodiment, pre-brake control is performed before the main brake control to previously control the reduction in the rotational speed of the crankshaft 30a that rotates by inertia.

[0048] 7 is a timing chart showing an example of transitions of the engine speed NE and the driving state of the electric motor 34 with respect to the crank angle θ during pre-brake control. The pre-brake control is initiated on the condition that NE becomes equal to or less than a threshold speed NEth. In the pre-brake control, the electric motor 34 is controlled so that the speed NE of the crankshaft 30a decreases in accordance with predetermined target transition information Tne. In this embodiment, the target transition information Tne defines a target value of NE with respect to θ. In the illustrated example, the target transition information Tne has a profile in which NE temporarily increases monotonically when θ exceeds 0 degrees, and then decreases monotonically toward θ=720 degrees.

[0049] By reducing the rotational speed of the crankshaft 30a, which rotates by inertia after the automatic stop, in accordance with the target transition information Tne, it is possible to suppress variations in the reduction in rotation speed and accurately stop the crankshaft 30a at the start preparation position P under main brake control. Accurate stopping reduces the frequency of subsequent position adjustments, and also enables the crankshaft 30a to be quickly stopped at the start preparation position P. Therefore, restartability can be improved even when a restart is requested immediately after the automatic stop of the engine 30. In particular, if the engine 30 automatically stops while the vehicle 100 is decelerating and stopping, and a restart request is made immediately after the vehicle 100 stops, it becomes possible to position the crankshaft 30a at the start preparation position P before the vehicle 100 stops, further improving restartability.

[0050] In this embodiment, PWM control is assumed as the output control method for the electric motor 34. However, in the pre-brake control, in order to simplify the control of the current supply to the electric motor 34, either an ON state with a duty ratio of 100% or an OFF state with a duty ratio of 0% is selected to control the reduction in the rotational speed of the crankshaft 30a. In the ON state, a braking force caused by the drive of the electric motor 34 acts on the crankshaft 30a. In the OFF state, the electric motor 34 is not driven, and therefore the braking force does not act on the crankshaft 30a. "ON" and "OFF" in FIG. 7 indicate the ON state and the OFF state, respectively. Note that in this embodiment, the duty ratio in the ON state is 100%, but it may be a ratio other than 100%, such as 80% or 90%.

[0051] In this embodiment, feedback control is used to reduce the rotation speed NE of the crankshaft 30a in accordance with the target transition information Tne. More specifically, state data of the engine rotation speed NE (referred to as the detected rotation speed Dne) is compared with the target transition information Tne, and control is performed so that the detected rotation speed Dne follows the target transition information Tne. By using feedback control, the rotation speed NE of the crankshaft 30a can be reduced more accurately in accordance with the target transition information Tne.

[0052] Here, control may be performed so that the detected rotation speed Dne exactly matches the target transition information Tne. However, when the detected rotation speed Dne is lower than the target transition information Tne, the need for control is low. Therefore, in this embodiment, when the target transition information Tne exceeds the detected rotation speed Dne, the ON state is selected, and when the detected rotation speed Dne is equal to or lower than the target transition information Tne, the OFF state is selected. In FIG. 7, the ON state is selected in sections R1, R2, and R3 where the target transition information Tne exceeds the detected rotation speed Dne, suppressing an increase in the rotation speed of the crankshaft 30a, and the OFF state is selected in other sections. In this way, by controlling the electric motor 34 only when there is a high need for rotation speed adjustment, control can be simplified.

[0053] 8 is a flowchart showing an example of the stop position control process in S15 of FIG. 5. In S21, it is determined based on the state data whether the detected rotation speed Dne is equal to or less than the threshold rotation speed NEth. If the detected rotation speed Dne is equal to or less than the threshold rotation speed NEth, the process proceeds to S22. The threshold rotation speed NRth is set to a low rotation speed range at which the centrifugal clutch 36 is in the transmission cut-off state. With the centrifugal clutch 36 in the transmission cut-off state, pre-brake control can be performed in a state where the load from the road surface via the rear wheel 112 is not transmitted to the crankshaft 30a. This allows control to be performed that is not affected by the driving state, improving the accuracy of the stop position of the crankshaft 30a.

[0054] In S22, it is determined based on the status data whether the crankshaft 30a is rotating forward or not. If it is determined that the crankshaft 30a is rotating forward, the process proceeds to S23. If it is determined that the crankshaft 30a has already stopped or is rotating in the reverse direction, the process proceeds to S27.

[0055] In S23, pre-brake control is executed. FIG. 9 is a flowchart showing an example of the processing of the pre-brake control in S23. In S31, a target rotational speed is set based on the target transition information Tne and θ based on the state data. That is, among the rotational speeds defined in the target transition information Tne, the rotational speed corresponding to the current θ is read and set. In S32, it is determined whether or not the detected rotational speed Dne based on the state data exceeds the target rotational speed set in S31. If the detected rotational speed Dne exceeds the target rotational speed, the process proceeds to S33; if not, the process proceeds to S34. In S33, the electric motor 34 is driven at a duty ratio of 100%. Thereby, an increase in the rotational speed of the crankshaft 30a is suppressed. Then, the process proceeds to S35. In S34, the electric motor 34 is turned OFF (duty ratio 0%), and then the process proceeds to S35.

[0056] In S36, it is determined whether or not the end condition of the pre-brake control is satisfied. If the end condition is satisfied, the pre-brake control is terminated. The end conditions can include, for example, that the detected rotational speed Dne is less than or equal to the threshold rotational speed (<NEth), that the execution time of the pre-brake control has reached the specified time, and that θ based on the state data has reached the braking start position θs. If any one of these is satisfied, the pre-brake control may be terminated.

[0057] Return to FIG. 8. In S24, it is determined whether or not the crankshaft 30a is rotating forward based on the state data. If it is determined that it is rotating forward, the process proceeds to S25; if it is determined that the crankshaft 30a has already stopped or is rotating backward, the process proceeds to S27. In S25, main-brake control is executed. FIG. 10 is a flowchart showing an example of the processing of the main-brake control in S25.

[0058] In S41, it is determined based on the status data whether the angle θ of the crankshaft 30a has reached the braking start position θs. If it is determined that the angle θ of the crankshaft 30a has reached the braking start position θs, the process proceeds to S42. In S42, the electric motor 34 is driven at a duty ratio of 100%. This duty ratio of 100% is maintained until the main brake control ends, and the crankshaft 30a is stopped. By fixing the duty ratio at 100%, the braking force can be increased. Since the main brake control aims to immediately stop the crankshaft 30a, feedback control like pre-brake control is not performed. After S42, the process proceeds to S43.

[0059] In S43, it is determined whether the crankshaft 30a has stopped. In this embodiment, the criterion is whether the crankshaft 30a has rotated in the reverse direction. That is, in S43, it is determined whether the crankshaft 30a has rotated in the reverse direction based on the status data. For example, if the crankshaft 30a has rotated in the reverse direction by a predetermined angle, it is determined that the crankshaft 30a has rotated in the reverse direction. Alternatively, if the reverse rotation of the crankshaft 30a has continued for a predetermined time, it is determined that the crankshaft 30a has rotated in the reverse direction. Alternatively, if any of these conditions is confirmed, it is determined that the crankshaft 30a has rotated in the reverse direction. Using the reverse rotation as the criterion makes it easier to determine whether the crankshaft 30a has stopped, and also prevents the crankshaft 30a from being erroneously determined to have stopped if it continues to rotate in the forward direction without stopping, thereby making it possible to more reliably determine whether the crankshaft 30a has stopped. If it is determined that the crankshaft 30a has rotated in the reverse direction, the main brake control is terminated.

[0060] Returning to FIG. 8, in S26, it is determined based on the status data whether the position of the crankshaft 30a is deviated from the start preparation position P. If it is determined that the position is not deviated, the process proceeds to S28, where the electric motor 34 is turned OFF. If it is determined that the position is deviated, the process proceeds to S27. In S27, control is executed to drive the electric motor 34 to advance or return the crankshaft 30a to the start preparation position P, and if the position of the crankshaft 30a is at the start preparation position P, the process proceeds to S28. Even if an error occurs in the pre-brake control or the main brake control, the stop position adjustment control in S27 can reliably prepare for restart.

[0061] <Restart control> An example of the restart control in S17 of Figure 5 will be described. The restart condition may be satisfied (S16) even before the vehicle 100 stops (during the stop position control (S15)). Depending on the control stage of the stop position control and the degree of throttle operation by the rider, the vehicle may not be able to restart smoothly. In particular, during the main brake control (S25), the decompression mechanism 90 may be in both an operating state and an inoperable state. Because the rotation speed of the crankshaft 30a is relatively low, if the decompression mechanism 90 is in an inoperable state, the compression top dead center may not be able to be smoothly passed depending on the position of the piston.

[0062] Therefore, in this embodiment, restarting is performed when the decompression mechanism 90 is in an operating state. Figure 11 is a flowchart showing an example of restart control (S17).

[0063] In S51, it is determined whether the current control stage is main brake control. Information about the control stage is stored and updated in the storage unit 12, for example, and the determination in S51 can be made by referring to this information. If the current control stage is main brake control, the process proceeds to S52; if not, the process proceeds to S53.

[0064] In S52, it is determined whether the engine speed (coasting speed) NE is equal to or less than the decompression action speed. If the engine speed NE is equal to or less than the decompression action speed, the process proceeds to S53; if not, the process of S52 is repeated. In S53, the engine 30 is restarted. The electric motor 34 is driven as a starter to rotate the crankshaft 30a in the forward direction, while the fuel injection device 32 supplies fuel and the ignition device 33 ignites it to drive the engine 30.

[0065] In this manner, in this embodiment, if the restart condition is met during the main brake control (S25), restarting can be delayed until the decompression mechanism 90 is in an operating state, thereby improving restartability.

[0066] <Starting assist control> An example of drive control of the electric motor 34 in the normal start control and the restart control (S17) will be described. When starting the engine 30, the electric motor 34 is driven as a starter, thereby enabling the engine 30 to be started smoothly. In particular, when restarting the engine 30 after an automatic stop, the restartability can be improved by the assistance of the electric motor 34.

[0067] Specifically, as described above, the restart condition (S16) may be satisfied before the vehicle 100 is stopped (during the stop position control (S15)). If the restart condition is satisfied immediately after the automatic stop of the engine 30, when the engine speed (coastal speed) NE is relatively high, and the rider performs an operation to open the throttle widely, the pressure in the cylinder increases. Depending on the position of the piston, it may not be possible to smoothly go over the compression top dead center. Therefore, by driving the electric motor 34 to assist the start when restarting the engine 30, a smooth restart can be achieved.

[0068] On the other hand, during normal start control, the engine 30 needs to be started from a stopped state. If a relatively low-output electric motor 34 is used, the electric motor 34 alone may not provide enough driving force, which may result in an unsmooth start of the engine 30. Therefore, during normal start control, the drive control of the electric motor 34 needs to be performed so that the engine 30 is started within the operating range of the decompression mechanism 90. If the drive control of the electric motor 34 were performed identically during normal start control and restart control, the engine 30 may exceed the operating range of the decompression mechanism 90 before the engine 30 is started, which may prevent the decompression mechanism 90 from continuing to operate, resulting in an unsmooth start of the engine 30. Therefore, in this embodiment, different drive controls are performed during normal start control and restart control (S17).

[0069] FIG. 12A is a flowchart showing an example of drive control of the electric motor 34 executed by the processing unit 11 of the control device 10, and particularly shows an example of processing related to starting assistance for the engine 30. In S61, it is determined whether the engine speed NE is equal to or less than a threshold value THs. If it is equal to or less than the threshold value THs, the process proceeds to S62, and if it exceeds the threshold value THs, the process proceeds to S63. The threshold value THs is, for example, a speed lower than the idling speed, more specifically, several hundred rpm. When the engine speed NE is equal to or less than the threshold value THs, this includes, for example, a case where normal start control is performed (when the engine 30 is started by the rider's start operation). When the engine speed NE exceeds the threshold value THs, this includes, for example, a case where the restart condition is met after an automatic stop when the engine speed (coastal speed) NE is relatively high.

[0070] Normal assist control is executed at S62. Fig. 12B is a flowchart showing an example of the normal assist control process.

[0071] In S71, the electric motor 34 is driven. Here, the electric motor 34 is driven at a relatively high duty ratio (for example, a ratio in the range of 80 to 100%). In S72, it is determined whether the engine speed NE is equal to or greater than the specified speed NL. If the engine speed NE is equal to or greater than the specified speed NL, the process proceeds to S73, and if the engine speed NE is less than the specified speed NL, the process of S72 is repeated. In other words, the driving of the electric motor 34 continues until the engine speed NE reaches the specified speed NL, and once the engine speed NE reaches the specified speed NL, it is determined that the engine 30 has started stably. In S73, the driving of the electric motor 34 is terminated.

[0072] In step S63 of Fig. 12(A), the restart assist control is executed. Fig. 12(C) is a flowchart showing an example of the restart assist control process.

[0073] In S81, the electric motor 34 is driven. Here, the electric motor 34 is driven at a relatively high duty ratio (for example, a ratio in the range of 80 to 100%). In S82, it is determined whether the engine speed NE is equal to or greater than a specified speed NH. If the engine speed NE is equal to or greater than the specified speed NH, the process proceeds to S83, and if the engine speed NE is less than the specified speed NH, the process of S82 is repeated. In other words, the driving of the electric motor 34 continues until the engine speed NE reaches the specified speed NH, and once the engine speed NE reaches the specified speed NH, it is determined that the engine 30 has started stably. In S83, the driving of the electric motor 34 is terminated.

[0074] The specified rotation speeds NL and NH have a relationship of specified rotation speed NL<specified rotation speed NH. The specified rotation speed NL is set, for example, to approximately the idling rotation speed of the engine 34, and the specified rotation speed NH is set, for example, to be several hundred rotations higher than the specified rotation speed NL. When compared with the decompression action rotation speed, for example, the specified rotation speed NL may be equal to or lower than the decompression action rotation speed, and the specified rotation speed NH may be higher than the decompression action rotation speed. When compared with the threshold rotation speed NEth, which is the start condition for pre-brake control, for example, the relationship may be specified rotation speed NL<threshold rotation speed NEth<specified rotation speed NH. When the restart condition is met immediately after the start of pre-brake control, the electric motor 34 is driven up to the specified rotation speed NH, thereby improving the restartability of the engine 34.

[0075] Through this control, restart assistance by the electric motor 34 continues up to higher rotation speeds during restart, thereby improving restartability. Note that during restart, even a relatively low-output electric motor 34 contributes to restart due to the inertia of the pistons of the engine 30. On the other hand, by setting the specified rotation speed NL during normal start triggered by the rider's start operation rather than uniformly setting the specified rotation speed to NH, it is possible to promote the establishment of starting of the engine 30 within the operating range of the decompression mechanism 90. Therefore, startability can be ensured in both normal start and restart.

[0076] By switching between normal assist control and restart assist control based on the engine speed NE, it is possible to distinguish between normal start and restart, and even in the case of restart, if the engine speed NE is low, control equivalent to normal assist control is performed, ensuring startability.

[0077] Second Embodiment In the example of restart control shown in Fig. 11, restart is started based on the engine speed NE, but it may also be based on the elapsed time of main brake control. Fig. 13 is a flowchart showing an example of restart control (S17) that replaces that shown in Fig. 11.

[0078] In S51, it is determined whether the current control stage is main brake control. This is the same processing as in the example of Figure 11. If the current control stage is main brake control, the processing proceeds to S52', and if not, the processing proceeds to S53.

[0079] In S52', it is determined whether the elapsed time from the start of main brake control exceeds a predetermined time. The elapsed time is measured, for example, by a software timer that starts measuring time from the start of main brake control. The predetermined time is determined, for example, by experiment or simulation, as the longest time from the start of main brake control until the decompression mechanism 90 enters an actuated state, and the determined longest time is set as the predetermined time.

[0080] If the elapsed time exceeds the predetermined time, the process proceeds to S53, otherwise the process of S52' is repeated. In S53, the engine 30 is restarted. This is the same process as in the example of FIG.

[0081] <Other embodiments> In the above embodiment, the condition for starting the pre-brake control is that the detected rotation speed Dne is equal to or less than the threshold rotation speed NEth (S21), but a requirement for the angle θ of the crankshaft 30a may also be added. For example, in the example of Fig. 6, the pre-brake control is started before the angle θ of the crankshaft 30a becomes 0 degrees, but it may be started after the angle θ becomes 0 degrees.

[0082] In the above embodiment, the saddle-ride type vehicle 100 is provided with the centrifugal clutch 36 and the continuously variable transmission 35. However, the present invention can also be applied to a saddle-ride type vehicle with a manual clutch and transmission, or a saddle-ride type vehicle with an automatic clutch and automatic transmission. In either case, the stop position control can be executed only if the clutch is in a disengaged state.

[0083] 11, the determination is made based on the control stage, but the determination may also be made based on the engine speed NE. In this case, if the engine speed NE is equal to or less than a predetermined threshold, the process may proceed to S52, and if the engine speed NE exceeds the predetermined threshold, the process may proceed to S53. The same applies to the example in FIG. 13.

[0084] In the determination of S61 in Fig. 12(A), the engine speed NE is used as the criterion, but the determination may also be based on the type of start control (normal start control or restart control). In this case, if the normal start control is selected, the process may proceed to S62, and if the restart control is selected, the process may proceed to S63.

[0085] In the above embodiment, the stop position control (S15) is performed after the automatic stop control (S13), but the stop position control (S15) may not be performed. In this case, the processing of Fig. 11, Fig. 12(A) to Fig. 12(C), or Fig. 13 can be performed. In the processing of Fig. 11 and Fig. 13, the engine speed NE may be used as a reference for the determination in S51.

[0086] <Summary of the embodiment> The above-described embodiments disclose at least the following vehicle control device, control method, and saddle-ride type vehicle.

[0087] Item 1. A vehicle control device (10) including an auxiliary control means (11) that performs normal auxiliary control to drive an electric motor (34) capable of assisting the start of an engine (30) mounted on a vehicle (100) until the engine (30) reaches a first specified rotation speed (NL) when the engine (30) is started, the engine (30) is automatically stopped when an idle stop condition is satisfied, and is restarted when a restart condition is satisfied; The auxiliary control means (11) When restarting the engine (30), a restart assist control can be executed to drive the electric motor (34) until the engine (30) reaches a second specified rotation speed (NH) higher than the first specified rotation speed (NL). A vehicle control device comprising:

[0088] According to this embodiment, it is possible to provide a technology for improving the restartability of the engine after the automatic stop, and to ensure the startability of the engine in both the normal start and the restart.

[0089] Item 2. The vehicle control device (10) according to item 1, The normal auxiliary control is executed when the rotation speed of the engine (30) is equal to or lower than a threshold value (THs), The restart assist control is executed when the rotation speed of the engine (30) exceeds the threshold value (THs). A vehicle control device comprising:

[0090] According to this embodiment, by using the engine speed as a reference, engine startability can be ensured in both normal start and restart cases.

[0091] Item 3. The vehicle control device (10) according to item 1, The idle stop condition is a condition that can be satisfied while the vehicle (100) is traveling, The restart condition is a condition that can be met while the vehicle (100) is running. A vehicle control device comprising:

[0092] According to this embodiment, the fuel efficiency of the vehicle can be improved.

[0093] Item 4. The vehicle control device (10) according to item 1, an automatic stop control means (11) for controlling the engine (30) to automatically stop and restart the engine (30); The automatic stop control means (11) When the idle stop condition is satisfied, the engine (30) is automatically stopped, and a stop position control is executed to brake the crankshaft (30a) of the engine (30) rotating by inertia with the driving force of the electric motor (34) and stop the crankshaft (30a) at a predetermined position (P), The stop position control is a pre-brake control for controlling the electric motor (34) so ​​that the rotational speed of the crankshaft (30a) decreases in accordance with predetermined target transition information (Tne); and a main brake control for controlling the electric motor so that the crankshaft (30a) stops at the predetermined position (P) after the pre-brake control. A vehicle control device comprising:

[0094] According to this embodiment, when the engine is automatically stopped, the crankshaft rotating by inertia can be stopped accurately at a predetermined position, thereby improving restartability.

[0095] Item 5. A vehicle control device (10) according to item 4, the pre-brake control is initiated when the rotational speed of the engine (30) decreases to a predetermined rotational speed that is higher than the first specified rotational speed (NL) and lower than the second specified rotational speed (NH). A vehicle control device comprising:

[0096] According to this embodiment, if the restart condition is met immediately after the start of the pre-brake control, the electric motor is driven up to the second specified rotation speed, thereby improving the restartability of the engine.

[0097] Item 6. A vehicle control device (10) according to item 4, The engine (30) is provided with a decompression mechanism (90) that opens a valve of the engine (30) to reduce compression torque when the engine (30) is started, The automatic stop control means (11) When the restart condition is satisfied during the main brake control, restart of the engine (30) is started after the rotation speed of the engine (30) falls below the rotation speed at which the compression torque reduction function of the decompression mechanism (90) operates. A vehicle control device comprising:

[0098] According to this embodiment, the engine is restarted with the decompression mechanism in an operating state, thereby improving restartability.

[0099] Item 7. A vehicle control device (10) according to item 4, The engine (30) is provided with a decompression mechanism (90) that opens a valve of the engine (30) to reduce compression torque when the engine (30) is started, The automatic stop control means (11) If the restart condition is satisfied during the main brake control, restart of the engine (30) is started after a predetermined time has elapsed since the start of the main brake control. A vehicle control device comprising:

[0100] According to this embodiment, the engine can be easily restarted with the decompression mechanism in operation, thereby improving restartability.

[0101] Item 8. A control method for controlling an engine (30) mounted on a vehicle and an electric motor (34) capable of assisting starting of the engine (30), comprising: a normal auxiliary control step of driving the engine (30) until the engine (30) reaches a first specified rotation speed (NL) when the engine (30) is started; an automatic stop step of automatically stopping the engine (30) when an idle stop condition is satisfied; a restart step of restarting the automatically stopped engine (30) when a restart condition is met, In the restart step, a restart assist control step can be executed in which the electric motor (34) is driven until the engine (30) reaches a second specified rotation speed (NH) higher than the first specified rotation speed (NL). A control method comprising:

[0102] According to this embodiment, it is possible to provide a technology for improving the restartability of the engine after the engine has been automatically stopped. The startability of the engine can be ensured in both the normal start and the restart.

[0103] Item 9. an engine (30); an electric motor (34) capable of rotating a crankshaft (30a) of the engine (30); a control means (11) for controlling the engine (30) and the electric motor (34); A saddle-type vehicle (100) comprising: The control means (11) a normal start control for starting the engine (30) based on a rider's start operation and driving the electric motor until the engine (30) reaches a first specified rotation speed (NL); an automatic stop control for automatically stopping the engine (30) when an idle stop condition is satisfied; a restart control for restarting the automatically stopped engine (30) when a restart condition is met; In the restart control, the control means (11) is capable of executing a restart assist control for driving the electric motor until the engine (30) reaches a second specified rotation speed (NH) that is higher than the first specified rotation speed (NL). A saddle-type vehicle characterized by:

[0104] According to this embodiment, it is possible to provide a technology for improving the restartability of the engine after the engine has been automatically stopped. The startability of the engine can be ensured in both the normal start and the restart.

[0105] Although the embodiments of the invention have been described above, the invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the gist of the invention. [Explanation of symbols]

[0106] 11 processing units, 30 engines, 34 electric motors, 100 vehicles

Claims

1. A vehicle control device (10) including an auxiliary control means (11) that performs normal auxiliary control to drive an electric motor (34) capable of assisting the start of an engine (30) mounted on a vehicle (100) until the engine (30) reaches a first specified rotation speed (NL) when the engine (30) is started, the engine (30) is automatically stopped when an idle stop condition is satisfied, and is restarted when a restart condition is satisfied; The auxiliary control means (11) When restarting the engine (30), a restart assist control can be executed to drive the electric motor (34) until the engine (30) reaches a second specified rotation speed (NH) higher than the first specified rotation speed (NL). A vehicle control device comprising:

2. 2. A vehicle control device (10) according to claim 1, The normal auxiliary control is executed when the rotation speed of the engine (30) is equal to or lower than a threshold value (THs), The restart assist control is executed when the rotation speed of the engine (30) exceeds the threshold value (THs). A vehicle control device comprising:

3. 2. A vehicle control device (10) according to claim 1, The idle stop condition is a condition that can be satisfied while the vehicle (100) is traveling, The restart condition is a condition that can be met while the vehicle (100) is running. A vehicle control device comprising:

4. 2. A vehicle control device (10) according to claim 1, an automatic stop control means (11) for controlling the engine (30) to automatically stop and restart the engine (30); The automatic stop control means (11) When the idle stop condition is satisfied, the engine (30) is automatically stopped, and a stop position control is executed to brake the crankshaft (30a) of the engine (30) rotating by inertia with the driving force of the electric motor (34) and stop the crankshaft (30a) at a predetermined position (P), The stop position control is a pre-brake control for controlling the electric motor (34) so ​​that the rotational speed of the crankshaft (30a) decreases in accordance with predetermined target transition information (Tne); and a main brake control for controlling the electric motor so that the crankshaft (30a) stops at the predetermined position (P) after the pre-brake control. A vehicle control device comprising:

5. 5. A vehicle control device (10) according to claim 4, the pre-brake control is initiated when the rotational speed of the engine (30) decreases to a predetermined rotational speed that is higher than the first specified rotational speed (NL) and lower than the second specified rotational speed (NH). A vehicle control device comprising:

6. 5. A vehicle control device (10) according to claim 4, The engine (30) is provided with a decompression mechanism (90) that opens a valve of the engine (30) to reduce compression torque when the engine (30) is started, The automatic stop control means (11) When the restart condition is satisfied during the main brake control, restart of the engine (30) is started after the rotation speed of the engine (30) falls below the rotation speed at which the compression torque reduction function of the decompression mechanism (90) operates. A vehicle control device comprising:

7. 5. A vehicle control device (10) according to claim 4, The engine (30) is provided with a decompression mechanism (90) that opens a valve of the engine (30) to reduce compression torque when the engine (30) is started, The automatic stop control means (11) If the restart condition is satisfied during the main brake control, restart of the engine (30) is started after a predetermined time has elapsed since the start of the main brake control. A vehicle control device comprising:

8. A control method for controlling an engine (30) mounted on a vehicle and an electric motor (34) capable of assisting starting of the engine (30), comprising: a normal auxiliary control step of driving the engine (30) until the engine (30) reaches a first specified rotation speed (NL) when the engine (30) is started; an automatic stop step of automatically stopping the engine (30) when an idle stop condition is satisfied; a restart step of restarting the automatically stopped engine (30) when a restart condition is met, In the restart step, a restart assist control step can be executed in which the electric motor (34) is driven until the engine (30) reaches a second specified rotation speed (NH) higher than the first specified rotation speed (NL). A control method comprising:

9. an engine (30); an electric motor (34) capable of rotating a crankshaft (30a) of the engine (30); a control means (11) for controlling the engine (30) and the electric motor (34); A saddle-type vehicle (100) comprising: The control means (11) a normal start control for starting the engine (30) based on a rider's start operation and driving the electric motor until the engine (30) reaches a first specified rotation speed (NL); an automatic stop control for automatically stopping the engine (30) when an idle stop condition is satisfied; a restart control for restarting the automatically stopped engine (30) when a restart condition is met; In the restart control, the control means (11) is capable of executing a restart assist control for driving the electric motor until the engine (30) reaches a second specified rotation speed (NH) that is higher than the first specified rotation speed (NL). A saddle-type vehicle characterized by:

Images