WO2016013045A1 - Engine system and saddle-type vehicle - Google Patents

Abstract

A forward-rotation positioning operation in which a crankshaft is rotated in the forward direction is performed before starting an engine, and a reverse-rotation starting operation in which the crankshaft is rotated in the reverse direction is performed when starting the engine. In the forward-rotation positioning operation, a rotation drive unit drives the crankshaft such that the crank angle reaches a predetermined reverse-rotation start range. In the reverse-rotation starting operation: the rotation drive unit drives the crankshaft such that the crank angle transitions from the reverse-rotation start range, passes through a predetermined starting air-intake range, and reaches a predetermined starting ignition range; a fuel injection device injects fuel when the crank angle is in the starting air-intake range, such that a fuel-air mixture passes through an air-intake port from an air-intake passage and is introduced into a combustion chamber; and an ignition device performs ignition when the crank angle is in the starting ignition range. Ignition by the ignition device is prohibited during the forward-rotation positioning operation.

Description

Engine system and saddle riding type vehicle

The present invention relates to an engine system and a saddle-ride type vehicle equipped with the same.

In saddle riding type vehicles such as motorcycles, when the engine is started, a large torque is required because the crank angle exceeds the angle corresponding to the first compression top dead center. Therefore, there is a technique for rotating the crankshaft in the reverse direction in order to improve the startability of the engine.

In the engine system described in Patent Document 1, the air-fuel mixture is introduced into the combustion chamber while the crankshaft is rotated in the reverse direction when the engine is started. The air-fuel mixture in the combustion chamber is ignited in a state where the air-fuel mixture in the combustion chamber is compressed by the rotation of the crankshaft in the reverse direction. The crankshaft is rotationally driven in the forward direction by the combustion energy of the air-fuel mixture, and the torque in the forward direction of the crankshaft is increased.

Further, before the engine is started, the crankshaft is rotated in the forward direction or the reverse direction so that the crank angle becomes a predetermined angle. As a result, the crankshaft can be rotated in the reverse direction from a certain position when the engine is started.
JP 2014-77405 A

When the crankshaft is aligned as described above before starting the engine, the inventors perform an unintended operation in response to the output of the crank angle sensor during the alignment operation. I found a problem that I cannot adjust properly.

An object of the present invention is to provide an engine system and a saddle-ride type vehicle capable of appropriately adjusting a crank angle before starting the engine.

(1) An engine system according to an aspect of the present invention includes an engine unit including an engine and a rotation drive unit, and a control unit that controls the engine unit, and the engine is disposed in an intake passage for guiding air to a combustion chamber. A fuel injection device arranged to inject fuel, an ignition device configured to ignite an air-fuel mixture in a combustion chamber, an intake valve that opens and closes an intake port, and an exhaust valve that opens and closes an exhaust port are driven. The rotary drive unit is configured to rotationally drive the crankshaft in the forward direction or the reverse direction, and the control unit rotates the crankshaft in the forward direction before starting the engine. The engine unit is controlled so that a reverse rotation start operation is performed in which the crankshaft is rotated in the reverse direction when the engine is started. The rotation drive unit drives the crankshaft so that the crank angle reaches a predetermined reverse rotation start range in the forward rotation alignment operation, and the crank angle is predetermined from the reverse rotation start range in the reverse rotation start operation. The crankshaft is driven to reach a predetermined starting ignition range beyond the predetermined starting intake range, and the valve drive unit is configured to rotate the intake port when the crank angle is within the starting intake range in the reverse rotation starting operation. The fuel injection device drives the intake valve so that the air-fuel mixture is introduced into the combustion chamber from the intake passage through the intake port when the crank angle is in the start intake range in the reverse rotation start operation. The ignition device is ignited when the crank angle is within the starting ignition range in the reverse rotation starting operation, and the control unit ignites the ignition device during the forward rotation alignment operation. To stop.

In this engine system, the engine unit performs a normal rotation alignment operation before starting the engine. In the forward rotation alignment operation, the crankshaft is rotated in the forward direction so that the crank angle reaches the reverse rotation start range. In this case, since ignition by the ignition device is prohibited, unintended combustion of the air-fuel mixture in the engine is prevented in response to the output of the crank angle sensor. Thereby, the crank angle can be appropriately adjusted to the reverse rotation start range.

After that, the engine unit performs reverse rotation starting operation when starting the engine. In this case, since the crankshaft is rotated in the reverse direction from the state where the crank angle is in the reverse rotation start range, the crank angle surely passes through the start intake air range. For this reason, the air-fuel mixture can be appropriately introduced into the combustion chamber, and the combustion of the air-fuel mixture can be appropriately caused in the combustion chamber. Thereby, the torque in the positive direction of the crankshaft is increased, and the crank angle can easily exceed the angle corresponding to the first compression top dead center.

(2) The control unit may prohibit the fuel injection by the fuel injection device during the forward rotation alignment operation.

In this case, combustion of the air-fuel mixture is prevented during the forward rotation alignment operation, and adverse effects on the catalyst due to exhaust of the unburned air-fuel mixture from the combustion chamber are prevented.

(3) The engine system may further include a main switch operated by the driver, and the control unit may control the engine unit so that the forward rotation alignment operation is performed when the main switch is turned on.

In this case, the forward rotation alignment operation is appropriately performed before starting the engine.

(4) The engine system may further include a starter switch operated by the driver, and the control unit may control the engine unit so that the forward rotation alignment operation is performed when the starter switch is turned on.

In this case, the forward rotation alignment operation is appropriately performed before starting the engine.

(5) When the predetermined idling stop condition is satisfied, the control unit is configured so that the operations of the fuel injection device and the ignition device are stopped and the forward rotation alignment operation is performed after the rotation of the crankshaft is stopped. The engine unit may be controlled such that the reverse rotation starting operation is performed when a predetermined idling stop cancellation condition is satisfied by controlling the unit.

In this case, the engine is automatically stopped and restarted, and the forward rotation alignment operation is appropriately performed before the engine is restarted.

(6) Before starting the engine, the control unit does not prohibit ignition by the ignition device when the crankshaft rotates in the forward direction without being driven by the rotation driving unit. The ignition by the ignition device may be prohibited when the crankshaft is rotated in the forward direction by being driven by the rotation drive unit.

When the crankshaft is rotated in the positive direction by a starting operation such as pushing or kicking, the crankshaft is not driven by the rotation drive unit. On the other hand, when the crankshaft is rotated in the forward direction in the forward rotation starting operation, the crankshaft is driven by the rotation drive unit. Therefore, the presence or absence of ignition by the ignition device can be appropriately controlled based on the presence or absence of driving of the crankshaft by the rotation drive unit. Therefore, without requiring a complicated configuration and complicated control, the mixture is properly mixed when a start operation such as pushing or kick start occurs while preventing the combustion of the air-fuel mixture during the forward rotation alignment operation. The engine can be started by burning the air.

(7) The engine system further includes a kick starter that is operated by a driver's foot to rotate the crankshaft in the forward direction, and the control unit is configured to move the crankshaft in the forward direction by operating the kick starter by the driver. When rotating, the ignition by the ignition device may not be prohibited.

In this case, it is possible to start the engine by appropriately burning the air-fuel mixture during operation of the kick start unit while preventing the air-fuel mixture from burning during the forward rotation alignment operation.

(8) A saddle-ride type vehicle according to another aspect of the present invention includes a main body portion having drive wheels and the engine system that generates power for rotating the drive wheels.

In this saddle-ride type vehicle, since the engine system is used, the crank angle can be appropriately adjusted to the reverse rotation start range before the engine is started.

According to the present invention, the crank angle can be appropriately adjusted before the engine is started.

FIG. 1 is a schematic side view showing a schematic configuration of a motorcycle according to an embodiment of the present invention. FIG. 2 is a schematic diagram for explaining the configuration of the engine system. FIG. 3 is a diagram for explaining the normal operation of the engine unit. FIG. 4 is a diagram for explaining the forward rotation alignment operation and the reverse rotation start operation of the engine unit. FIG. 5 is a flowchart of the mode update process. FIG. 6 is a flowchart for explaining the engine start process. FIG. 7 is a flowchart for explaining the engine start process. FIG. 8 is a flowchart for explaining the engine start process. FIG. 9 is a flowchart for explaining the engine start process.

Hereinafter, a motorcycle will be described as an example of a saddle-ride type vehicle according to an embodiment of the present invention with reference to the drawings.

(1) Motorcycle FIG. 1 is a schematic side view showing a schematic configuration of a motorcycle according to an embodiment of the present invention. In the motorcycle 100 of FIG. 1, a front fork 2 is provided at the front portion of the vehicle body 1 so as to be swingable in the left-right direction. A handle 4 is attached to the upper end of the front fork 2, and a front wheel 3 is rotatably attached to the lower end of the front fork 2.

The seat 5 is provided at the substantially upper center of the vehicle body 1. Below the seat 5, an ECU (Engine Control Unit) 6 and an engine unit EU are provided. The engine unit EU includes, for example, a single cylinder engine 10. The engine unit EU is provided with a kick pedal KP for starting the engine 10. The engine system 200 is configured by the ECU 6, the engine unit EU, and the kick pedal KP. A rear wheel 7 is rotatably attached to the lower rear end of the vehicle body 1. The rear wheel 7 is rotationally driven by the power generated by the engine 10.

(2) Engine System FIG. 2 is a schematic diagram for explaining the configuration of the engine system 200. As shown in FIG. 2, the engine unit EU includes an engine 10 and a starter / generator 14. The engine 10 includes a piston 11, a connecting rod 12, a crankshaft 13, an intake valve 15, an exhaust valve 16, a valve drive unit 17, a spark plug 18 and an injector 19.

The piston 11 is provided so as to be able to reciprocate in the cylinder 31 and is connected to the crankshaft 13 via a connecting rod 12. The reciprocating motion of the piston 11 is converted into the rotational motion of the crankshaft 13. A starter / generator 14 is provided on the crankshaft 13. The starter / generator 14 is a generator having a function of a starter motor, and rotates the crankshaft 13 in the forward direction and the reverse direction and generates electric power by the rotation of the crankshaft 13. The forward direction is the direction of rotation of the crankshaft 13 during normal operation of the engine 10, and the reverse direction is the opposite direction. The starter / generator 14 directly transmits torque to the crankshaft 13 without using a reduction gear. When the rotation of the crankshaft 13 in the positive direction is transmitted to the rear wheel 7, the rear wheel 7 is rotationally driven.

The kick pedal KP is connected to the crankshaft 13. When the driver operates the kick pedal KP with his / her foot, the crankshaft 13 is rotated forward. Hereinafter, starting the engine 10 by operating the kick pedal KP is referred to as kick start.

A combustion chamber 31 a is formed on the piston 11. The combustion chamber 31 a communicates with the intake passage 22 through the intake port 21 and communicates with the exhaust passage 24 through the exhaust port 23. An intake valve 15 is provided to open and close the intake port 21, and an exhaust valve 16 is provided to open and close the exhaust port 23. The intake valve 15 and the exhaust valve 16 are driven by a valve drive unit 17. The intake passage 22 is provided with a throttle valve TV for adjusting the flow rate of air flowing from the outside. The spark plug 18 is configured to ignite the air-fuel mixture in the combustion chamber 31a. The injector 19 is configured to inject fuel into the intake passage 22.

ECU6 contains CPU (central processing unit) and memory, for example. A microcomputer may be used instead of the CPU and the memory. A main switch 40, a starter switch 41, an intake pressure sensor 42, a crank angle sensor 43, and a current sensor 44 are electrically connected to the ECU 6. The main switch 40 is provided, for example, below the handle 4 in FIG. 1, and the starter switch 41 is provided, for example, in the handle 4 in FIG. The main switch 40 and the starter switch 41 are operated by the driver. The intake pressure sensor 42 detects the pressure in the intake passage 22. The crank angle sensor 43 detects the rotational position of the crankshaft 13 (hereinafter referred to as the crank angle). The current sensor 44 detects a current (hereinafter referred to as a motor current) flowing through the starter / generator 14.

The operation of the main switch 40 and the starter switch 41 is given to the ECU 6 as operation signals, and the detection results by the intake pressure sensor 42, the crank angle sensor 43 and the current sensor 44 are given to the ECU 6 as detection signals. The ECU 6 controls the starter / generator 14, the spark plug 18, and the injector 19 based on the given operation signal and detection signal.

(3) Engine Operation For example, the engine 10 is started when the starter switch 41 is turned on after the main switch 40 of FIG. 2 is turned on, and the engine 10 is stopped when the main switch 40 is turned off. The engine 10 can also be started by a starting operation such as pushing or kicking.

Further, the engine 10 may be automatically stopped when a predetermined idle stop condition is satisfied, and then the engine 10 may be automatically restarted when a predetermined idle stop cancellation condition is satisfied. . The idle stop condition includes, for example, a condition relating to at least one of a throttle opening (opening of the throttle valve TV), a vehicle speed, and a rotational speed of the engine 10. The idling stop release condition is, for example, that the throttle opening is larger than 0 when the accelerator grip is operated. Hereinafter, a state where the engine 10 is automatically stopped when the idle stop condition is satisfied is referred to as an idle stop state.

The engine unit EU performs a forward rotation alignment operation before the engine 10 is started, and performs a reverse rotation start operation when the engine 10 is started. However, when the engine 10 is started by pushing or kicking, the engine unit EU does not perform the reverse rotation starting operation. Thereafter, the engine unit EU performs a normal operation. FIG. 3 is a diagram for explaining a normal operation of the engine unit EU. FIG. 4 is a diagram for explaining the forward rotation alignment operation and the reverse rotation start operation of the engine unit EU.

In the following description, the top dead center through which the piston 11 passes during the transition from the compression stroke to the expansion stroke is referred to as the compression top dead center, and the top dead center through which the piston 11 passes during the transition from the exhaust stroke to the intake stroke. Called dead point. The bottom dead center through which the piston 11 passes during the transition from the intake stroke to the compression stroke is called the intake bottom dead center, and the bottom dead center through which the piston 11 passes during the transition from the expansion stroke to the exhaust stroke is called the expansion bottom dead center.

3 and 4, the rotation angle in the range of two rotations (720 degrees) of the crankshaft 13 is represented by one circle. Two rotations of the crankshaft 13 correspond to one cycle of the engine 10. The crank angle sensor 43 in FIG. 2 detects the rotational position of the crankshaft 13 in the range of one rotation (360 degrees). The ECU 6 determines whether the rotational position detected by the crank angle sensor 43 based on the pressure in the intake passage 22 detected by the intake pressure sensor 42 is one of the two rotations of the crankshaft 13 corresponding to one cycle of the engine 10. It is determined whether it corresponds to the rotation of. Thereby, the ECU 6 can acquire the rotational position of the crankshaft 13 in the range of two rotations (720 degrees).

3 and 4, the angle A0 is a crank angle when the piston 11 (FIG. 2) is located at the exhaust top dead center, and the angle A2 is a crank angle when the piston 11 is located at the compression top dead center. The angle A1 is a crank angle when the piston 11 is located at the intake bottom dead center, and the angle A3 is a crank angle when the piston 11 is located at the expansion bottom dead center. Arrow R1 represents the direction of change of the crank angle when the crankshaft 13 is rotating forward, and arrow R2 represents the direction of change of the crank angle when the crankshaft 13 is rotated reversely. Arrows P1 to P4 indicate the moving direction of the piston 11 when the crankshaft 13 rotates forward, and arrows P5 to P8 indicate the moving direction of the piston 11 when the crankshaft 13 rotates reversely.

(3-1) Normal Operation The normal operation of the engine unit EU will be described with reference to FIG. In normal operation, the crankshaft 13 (FIG. 2) rotates in the positive direction. Therefore, the crank angle changes in the direction of arrow R1. In this case, as indicated by arrows P1 to P4, the piston 11 (FIG. 2) descends in the range from the angle A0 to the angle A1, the piston 11 rises in the range from the angle A1 to the angle A2, and from the angle A2 The piston 11 descends in the range up to the angle A3, and the piston 11 rises in the range from the angle A3 to the angle A0.

At angle A11, fuel is injected into the intake passage 22 (FIG. 2) by the injector 19 (FIG. 2). In the positive direction, the angle A11 is located on the more advanced side than the angle A0. Subsequently, in the range from the angle A12 to the angle A13, the intake port 21 (FIG. 2) is opened by the intake valve 15 (FIG. 2). In the positive direction, the angle A12 is positioned more retarded than the angle A11 and more advanced than the angle A0, and the angle A13 is positioned more retarded than the angle A1. The range from the angle A12 to the angle A13 is an example of the normal intake range. Thereby, the air-fuel mixture containing air and fuel is introduced into the combustion chamber 31a (FIG. 2) through the intake port 21.

Next, at the angle A14, the air-fuel mixture in the combustion chamber 31a (FIG. 2) is ignited by the spark plug 18 (FIG. 2). In the positive direction, the angle A14 is located on the more advanced side than the angle A2. By igniting the air-fuel mixture, an explosion (combustion of the air-fuel mixture) occurs in the combustion chamber 31a. The combustion energy of the air-fuel mixture becomes the driving force for the piston 11. Thereafter, the exhaust port 23 (FIG. 2) is opened by the exhaust valve 16 (FIG. 2) in the range from the angle A15 to the angle A16. In the positive direction, the angle A15 is located on the more advanced side than the angle A3, and the angle A16 is located on the more retarded side than the angle A0. The range from the angle A15 to the angle A16 is an example of the normal exhaust range. Thereby, the gas after combustion is discharged | emitted through the exhaust port 23 from the combustion chamber 31a.

(3-2) Forward rotation alignment operation and reverse rotation start operation The forward rotation alignment operation and reverse rotation start operation of the engine unit EU will be described with reference to FIG. In the forward rotation alignment operation, the crank angle is adjusted to the reverse rotation start range by forward rotation of the crankshaft 13 (FIG. 2). The reverse rotation start range is, for example, in the range from angle A0 to angle A2 in the forward direction, and preferably in the range from angle A13 to angle A2. In this example, the reverse rotation start range is a range from the angle A30a to the angle A30b. The range from the angle A30a to the angle A30b is included in the range from the angle A13 to the angle A2. When the engine 10 is stopped with the crank angle being in the reverse rotation start range, the forward rotation alignment operation is not performed.

During the forward rotation alignment operation, fuel injection by the injector 19 and ignition by the spark plug 18 are prohibited. Thus, even when the crank angle reaches the angle A11 in FIG. 3, the fuel is not injected by the injector 19, and even when the crank angle reaches the angle A14 in FIG. 3, ignition by the spark plug 18 is not performed. Therefore, the air-fuel mixture is not burned in the combustion chamber 31a during the forward rotation alignment operation.

In the reverse rotation start operation, the crankshaft 13 is rotated in the reverse direction from the state where the crank angle is in the reverse rotation start range. As a result, the crank angle changes in the direction of arrow R2. In this case, as indicated by arrows P5 to P8, the piston 11 descends in the range from the angle A2 to the angle A1, the piston 11 rises in the range from the angle A1 to the angle A0, and from the angle A0 to the angle A3. The piston 11 descends in the range, and the piston 11 rises in the range from the angle A3 to the angle A2. The moving direction of the piston 11 when the crankshaft 13 rotates in the reverse direction is opposite to the moving direction of the piston 11 when the crankshaft 13 rotates in the forward direction.

In this example, during reverse rotation of the crankshaft 13, the intake port 21 is opened in the range from the angle A13 to the angle A12 and the exhaust port 23 is opened in the range from the angle A16 to A15, as in the forward rotation. Although opened, the present invention is not limited to this. During reverse rotation of the crankshaft 13, the intake port 21 may not be opened in the range from the angle A13 to the angle A12, and the exhaust port 23 may not be opened in the range from the angle A16 to the angle A15.

At angle A23, fuel is injected into the intake passage 22 (FIG. 2) by the injector 19 (FIG. 2). In the reverse direction, the angle A23 is located on the more advanced side than the angle A0. Further, in the range from the angle A21 to the angle A22, the intake port 21 (FIG. 2) is opened by the intake valve 15 (FIG. 2). The range from the angle A21 to the angle A22 is an example of the starting intake air range. In the reverse direction, the angles A21 and A22 are in the range from the angle A0 to the angle A3. Since the piston 11 rises in the range from the angle A1 to the angle A0, even if the intake port 21 is opened in the range from the angle A13 to the angle A12, air and fuel are hardly introduced into the combustion chamber 31a. On the other hand, since the piston 11 descends in the range from the angle A0 to the angle A3, the intake port 21 is opened in the range from the angle A21 to the angle A22, so that the air-fuel mixture containing air and fuel is taken in from the intake passage 22. It is introduced into the combustion chamber 31a through the port 21.

Subsequently, energization of the ignition coil connected to the ignition plug 18 (FIG. 2) is started at the angle A31a, and the air-fuel mixture in the combustion chamber 31a is ignited by the ignition plug 18 (FIG. 2) at the angle A31. . In the reverse direction, the angle A31a is located on the more advanced side than the angle A31, and the angle A31 is located on the more advanced side than the angle A2. The angle A31 is an example of the starting ignition range.

Further, at the angle A31, the rotation direction of the crankshaft 13 is switched from the reverse direction to the forward direction. In this case, the torque in the positive direction of the crankshaft 13 is increased by the combustion of the air-fuel mixture. Thereafter, the engine 10 shifts to the normal operation of FIG.

In the present embodiment, the air-fuel mixture in the combustion chamber 31a is ignited by the spark plug 18 after the reverse rotation of the crankshaft 13 is stopped. Thereby, the crankshaft 13 can be reliably driven in the forward direction. If it is possible to drive the crankshaft 13 in the forward direction by adjusting the ignition timing, etc., the air-fuel mixture in the combustion chamber 31a is stopped by the spark plug 18 before the reverse rotation of the crankshaft 13 is stopped. May be ignited.

As described above, in the present embodiment, when the engine 10 is started, the air-fuel mixture is guided to the combustion chamber 31a while the crankshaft 13 is reversely rotated by the starter / generator 14, and then the piston 11 is brought to the compression top dead center. In the approached state, the air-fuel mixture in the combustion chamber 31a is ignited. Thereby, the piston 11 is driven so that the crankshaft 13 rotates in the forward direction, and sufficient torque in the forward direction is obtained. As a result, the crank angle exceeds the angle A2 corresponding to the first compression top dead center.

(3-3) Adjustment of Crank Angle When the engine 10 is stopped, the rotation of the crankshaft 13 may stop in a state where the crank angle is in the range from the angle A0 to the angle A2 for the following reason.

When the valve drive unit 17 in FIG. 2 is a camshaft, the valve drive unit 17 rotates in conjunction with the rotation of the crankshaft 13. When the valve drive unit 17 lifts the intake valve 15, a biasing force of a valve spring (not shown) is applied as a reaction force from the intake valve 15 to the valve drive unit 17. Similarly, when the valve drive unit 17 lifts the exhaust valve 16, a biasing force of a valve spring (not shown) is applied as a reaction force from the exhaust valve 16 to the valve drive unit 17.

When the engine 10 is stopped, the air-fuel mixture is not combusted in the combustion chamber 31a, so that the rotational force of the crankshaft 13 and the valve drive unit 17 gradually decreases. In this case, the reaction force from the intake valve 15 or the exhaust valve 16 may stop the rotation of the valve drive unit 17 and the crankshaft 13 may stop rotating accordingly.

When the crank angle is in the vicinity of the angle A15, the reaction force from the exhaust valve 16 is applied to the valve drive unit 17. Thereby, when the crank angle is in the vicinity of the angle A15, the rotation of the crankshaft 13 tends to stop. Further, when the crank angle is in the vicinity of the angle A0, a reaction force from the intake valve 15 and a reaction force from the exhaust valve 16 are applied to the valve drive unit 17, respectively. Thereby, the rotation of the crankshaft 13 is easily stopped even when the crank angle is in the vicinity of the angle A0.

As described above, when the engine 10 is started, the crankshaft 13 is reversely rotated by the reverse rotation starting operation. At that time, if the reverse rotation start operation is started from a state where the crank angle is in the range from the angle A0 to the angle A31 in the reverse direction, the engine 10 cannot be started properly.

Specifically, when the reverse rotation of the crankshaft 13 is started from a state where the crank angle is in the range from the angle A15 to the angle A31, the crank angle is not passed through the range from the angle A21 to the angle A22. To reach. In this case, the air-fuel mixture is not introduced into the combustion chamber 31a. Therefore, at the angle A31, combustion of the air-fuel mixture does not occur in the combustion chamber 31a, and a driving force for rotating the crankshaft 13 in the forward direction cannot be obtained.

Also, the closer the crank angle is to the angle A31, the higher the pressure in the combustion chamber 31a. Therefore, when the crankshaft 13 does not have a rotation speed higher than a certain level, the crank angle does not easily reach the angle A31. If reverse rotation of the crankshaft 13 is started from a crank angle close to the angle A31, the rotation speed of the crankshaft 13 does not increase, and the crank angle may not reach the angle A31.

When the reverse rotation of the crankshaft 13 is started from a state where the crank angle is in the range from the angle A0 to the angle A21, the crank angle changes in the range from the angle A21 to the angle A22 while the rotation speed of the crankshaft 13 is low. . In this case, the air-fuel mixture is difficult to be introduced into the combustion chamber 31a in the range from the angle A21 to the angle A22. Therefore, even if the air-fuel mixture in the combustion chamber 31a is ignited at the angle A31, a sufficient driving force for rotating the crankshaft 13 in the forward direction cannot be obtained. Similarly to the above, there is a possibility that the rotational speed of the crankshaft 13 does not sufficiently increase and the crank angle does not reach the angle A31.

Therefore, in this embodiment, the crank angle is adjusted to the reverse rotation start range (in this example, the range from the angle A30a to the angle A30b) by the forward rotation alignment operation before the reverse rotation start operation. By starting reverse rotation of the crankshaft 13 from a state where the crank angle is in the reverse rotation start range, the rotational speed of the crankshaft 13 is sufficiently increased when the crank angle reaches the angle A21. Therefore, the air-fuel mixture is sufficiently introduced into the combustion chamber 31a in the range from the angle A21 to the angle A22. Further, since the rotation speed of the crankshaft 13 is sufficiently increased, the crank angle reliably reaches the angle A31. Therefore, the air-fuel mixture can be properly burned in the combustion chamber 31a at the angle A31. Thereby, sufficient driving force for rotating the crankshaft 13 in the forward direction is obtained. As a result, the engine 10 can be properly started.

(4) Control of fuel injection and ignition During forward rotation of the crankshaft 13, the ECU 6 controls the spark plug 18 and the injector 19 in one of the permission mode and the prohibit mode. In the permission mode, fuel is injected by the injector 19 when the crank angle is the angle A11 in FIG. 3, and the air-fuel mixture is ignited by the spark plug 18 when the crank angle is the angle A14 in FIG. On the other hand, in the prohibit mode, fuel injection by the injector 19 and ignition by the spark plug 18 are prohibited. Thereby, the fuel injection by the injector 19 and the ignition by the spark plug 18 are not performed regardless of the crank angle.

ECU6 performs a mode update process based on a control program stored in advance in the memory. Thereby, the control mode of ECU6 is updated suitably. FIG. 5 is a flowchart of the mode update process. The mode update process is continuously performed at a constant cycle while the main switch 40 is on.

As shown in FIG. 5, the ECU 6 determines whether or not the crankshaft 13 is rotating forward based on the detection result by the crank angle sensor 43 (FIG. 2) (step S1). When the crankshaft 13 is not rotated forward, the ECU 6 ends the mode update process without updating the control mode. When the crankshaft 13 is rotating forward, the ECU 6 determines whether or not the engine unit EU is operating normally (step S2).

If the engine unit EU is in normal operation, the ECU 6 updates the control mode to the permission mode (step S3) and ends the mode update process. Accordingly, as described above, the fuel is injected by the injector 19 at the angle A11 (FIG. 3) while the crankshaft 13 is rotated forward, and the air-fuel mixture in the combustion chamber 31a is injected by the spark plug 18 at the angle A14 (FIG. 3). Is ignited.

On the other hand, if the engine unit EU is not in normal operation, the ECU 6 determines whether or not the starter / generator 14 is driving the crankshaft 13 based on the detection result by the current sensor 44 (step S4). When the starter / generator 14 is driving the crankshaft 13, the engine unit EU is in the forward rotation alignment operation. In this case, the ECU 6 updates the control mode to the prohibit mode (step S5) and ends the mode update process. As a result, fuel injection by the injector 19 and ignition by the spark plug 18 are prohibited.

On the other hand, when the starter / generator 14 is not driving the crankshaft 13, there is a high possibility that the crankshaft 13 is normally rotated by a starting operation such as pushing or kicking. In this case, the ECU 6 updates the control mode to the permission mode (step S3) and ends the mode update process. Thus, the engine 10 is started by a starting operation such as pushing or kicking.

In this way, during normal rotation of the crankshaft 13 by normal operation, or during normal rotation of the crankshaft 13 by pushing or kick starting or the like, fuel injection by the injector 19 and ignition by the spark plug 18 are performed based on changes in the crank angle. Done. On the other hand, during forward rotation of the crankshaft 13 by forward rotation alignment operation, fuel injection by the injector 19 and ignition by the spark plug 18 are prohibited.

(5) Engine start process ECU6 performs an engine start process based on the control program previously memorize | stored in memory. 6 to 9 are flowcharts for explaining the engine start process. The engine start process is performed when the main switch 40 or the starter switch 41 in FIG. 2 is turned on or when the engine 10 shifts to the idle stop state.

(5-1) First Example FIGS. 6 to 8 are flowcharts of a first example of the engine start process. In the first example, first, the ECU 6 determines whether or not the current crank angle is stored in the memory (step S11). The current crank angle is stored in the memory when the engine 10 was stopped last time, for example. For example, immediately after the main switch 40 is turned on, the current crank angle is not stored. In the idle stop state, the current crank angle is stored.

If the current crank angle is not stored, the ECU 6 controls the starter / generator 14 so that the crankshaft 13 rotates in the forward direction (step S12). In this case, the torque of the starter / generator 14 is determined based on the detection signal from the current sensor 44 (FIG. 2) so that the crank angle does not reach the angle A2 (FIGS. 3 and 4) corresponding to the compression top dead center. Is adjusted.

As described above, the control mode of the spark plug 18 and the injector 19 is maintained in the prohibit mode during the forward rotation alignment operation. Therefore, at the time of forward rotation of the crankshaft 13 at step S12 and step S16 described later, fuel injection by the injector 19 and ignition by the spark plug 18 are prohibited.

Next, the ECU 6 determines whether or not a specified time has elapsed since the rotation of the crankshaft 13 was started in step S12 (step S13). When the specified time has not elapsed, the ECU 6 controls the starter / generator 14 so that the rotation of the crankshaft 13 in the positive direction is continued. When the specified time elapses, the ECU 6 controls the starter / generator 14 so that the rotation of the crankshaft 13 is stopped (step S14). Thereby, the crank angle is adjusted to the reverse rotation start range.

In step S12, the crank angle may be detected when the crankshaft 13 is rotated in the forward direction, and the crank angle may be adjusted to the reverse rotation start range based on the detected value.

On the other hand, if the current crank angle is stored in step S11, the ECU 6 determines whether or not the current crank angle is in the reverse rotation start range (step S15). If the current crank angle is not in the reverse rotation start range, the ECU 6 controls the starter / generator 14 so that the crankshaft 13 rotates in the forward direction (step S16). In this case, the torque of the starter / generator 14 is determined based on the detection signal from the current sensor 44 (FIG. 2) so that the crank angle does not reach the angle A2 (FIGS. 3 and 4) corresponding to the compression top dead center. Is adjusted.

Next, the ECU 6 determines whether or not the current crank angle has reached the reverse rotation start range based on detection signals from the intake pressure sensor 42 and the crank angle sensor 43 (step S17). If the current crank angle has not reached the reverse rotation start range, the ECU 6 controls the starter / generator 14 so that the forward rotation of the crankshaft 13 is continued (step S16). When the current crank angle reaches the reverse rotation start range, the ECU 6 controls the starter / generator 14 so that the rotation of the crankshaft 13 is stopped (step S14). Thereby, the crank angle is adjusted to the reverse rotation start range.

In the processes in steps S16 and S17, the crank angle is adjusted with higher accuracy than in the processes in steps S12 and S13, and the power consumption by the starter / generator 14 is suppressed.

7 After the crank angle is adjusted to the reverse rotation start range by forward rotation of the crankshaft 13, the process of step S21 in FIG. 7 is performed. In step S15, when the current crank angle is in the reverse rotation start range, the process of step S21 of FIG. 7 is performed as it is.

As shown in FIG. 7, in step S21, the ECU 6 determines whether or not a predetermined starting condition for the engine 10 is satisfied. The starting condition of the engine 10 is, for example, that the starter switch 41 (FIG. 2) is turned on or that the idle stop cancellation condition is satisfied.

In addition, when the engine start process is started by turning on the starter switch 41, the process of step S21 may not be performed. In that case, the forward rotation alignment operation and the reverse rotation start operation are continuously performed.

If the start condition of the engine 10 is satisfied, the ECU 6 performs a timeout setting for the engine start process (step S22). Specifically, the elapsed time is measured from that point. When the elapsed time reaches a predetermined end time, the engine start process is forcibly ended (step S38 described later).

Next, the ECU 6 controls the starter / generator 14 so that the crankshaft 13 is rotated in the reverse direction (step S23). Next, the ECU 6 determines whether or not the current crank angle has reached the angle A23 in FIG. 4 based on detection signals from the intake pressure sensor 42 (FIG. 2) and the crank angle sensor 43 (FIG. 2). (Step S24). The ECU 6 repeats the process of step S24 until the current crank angle reaches the angle A23. When the current crank angle reaches the angle A23, the ECU 6 controls the injector 19 so that fuel injection into the intake passage 22 (FIG. 2) is started (step S25). In this case, when the crank angle reaches the angle A23, a pulse signal is given from the crank angle sensor 43 to the ECU 6, and the ECU 6 may control the injector 19 so that fuel is injected in response to the pulse signal. .

Next, the ECU 6 determines whether or not a predetermined injection time has elapsed since the start of fuel injection in step S10 (step S26). The ECU 6 controls the injector 19 so that fuel injection is continued until a predetermined injection time has elapsed. When the predetermined injection time has elapsed, the ECU 6 controls the injector 19 so that the fuel injection is stopped (step S27).

Next, as shown in FIG. 8, the ECU 6 determines whether or not the motor current has reached a predetermined threshold value based on the detection signal from the current sensor 44 (step S31). In this case, the motor current increases as the crank angle approaches the angle A2 in FIG. In this example, when the crank angle reaches the angle A31 in FIG. 4, the motor current reaches the threshold value.

When the current flowing through the starter / generator 14 reaches a predetermined threshold value, the ECU 6 controls the starter / generator 14 so that the reverse rotation of the crankshaft 13 is stopped (step S32). Then, energization to the ignition coil is started (step S33). Next, the ECU 6 determines whether or not a predetermined energization time has elapsed since the energization was started in step S33 (step S34). The ECU 6 continues energization to the ignition coil until a predetermined energization time elapses. When a predetermined energization time has elapsed, the ECU 6 stops energizing the ignition coil (step S35). Thereby, the air-fuel mixture in the combustion chamber 31a is ignited by the spark plug 18. Further, the ECU 6 controls the starter / generator 14 so that the crankshaft 13 rotates in the forward direction (step S36). Thereby, ECU6 complete | finishes an engine starting process, and engine unit EU transfers to the normal operation | movement of FIG. Note that the driving of the crankshaft 13 by the starter / generator 14 is stopped after a predetermined time elapses from the process of step S36, for example.

In step S31, if the motor current has not reached the threshold value, the ECU 6 determines whether or not a predetermined end time has elapsed from the timeout setting in step S22 of FIG. 7 (step S37). Due to an abnormality in the engine unit EU, a predetermined end time may elapse from the timeout setting without the current flowing through the starter / generator 14 reaching the threshold value. The abnormality of the engine unit EU includes a malfunction of the starter / generator 14 or a malfunction of the valve drive unit 17. If the end time has not elapsed, the ECU 6 returns to the process of step S21. When the end time has elapsed, the ECU 6 controls the starter / generator 14 so that the reverse rotation of the crankshaft 13 is stopped (step S38), and informs the driver that an abnormality has occurred in the engine unit EU. A warning is given (step S39). Specifically, for example, a warning lamp (not shown) is turned on. Thereby, ECU6 complete | finishes an engine starting process.

(5-2) Second Example FIG. 9 is a flowchart of a second example of the engine start process. The ECU 6 may perform steps S41 to S51 in FIG. 9 instead of steps S31 to S39 in FIG.

In the example of FIG. 9, the ECU 6 determines the crankshaft 13 in advance after the reverse rotation of the crankshaft 13 is started in step S23 of FIG. 7 based on the detection signal from the crank angle sensor 43 (FIG. 2). It is determined whether or not the rotation angle has been reversed (step S41). The reverse rotation angle corresponds to, for example, an angle from the angle A30a to the angle A31 in FIG. For example, after a reverse rotation of the crankshaft 13 is started, if a prescribed number of pulses corresponding to the reverse rotation angle is given as a detection signal from the crank angle sensor 43, the ECU 6 determines that the crankshaft 13 has rotated the reverse rotation angle. judge.

When the crankshaft 13 rotates at the reverse rotation angle, the ECU 6 controls the starter / generator 14 so that the reverse rotation of the crankshaft 13 is stopped (step S42), and starts energizing the ignition coil (step S42). Step S43).

Next, after the energization is started in step S43, the ECU 6 determines whether or not the crankshaft 13 has rotated a predetermined energization angle (step S44). The energization angle corresponds to the angle at which the crankshaft 13 rotates during the energization time in step S24 of FIG. For example, after energization is started, when a specified number of pulses corresponding to the energization angle is given as a detection signal from the crank angle sensor 43, the ECU 6 determines that the crankshaft 13 has rotated the energization angle.

When the crankshaft 13 rotates at the energization angle, the ECU 6 stops energizing the ignition coil (step S45) and controls the starter / generator 14 so that the crankshaft 13 rotates in the forward direction (step S46). Then, the engine start process is terminated.

On the other hand, when the crankshaft 13 is not rotating at the reverse rotation angle in step S31, the ECU 6 determines whether or not a first end time predetermined from the timeout setting in step S7 has elapsed (step S47). . If the first end time has not elapsed, the ECU 6 returns to the process of step S41. When the first end time elapses, the ECU 6 controls the starter / generator 14 so that the reverse rotation of the crankshaft 13 is stopped (step S48), and that an abnormality has occurred in the engine unit EU. The driver is warned (step S51), and the engine start process is terminated.

If the crankshaft 13 is not rotated at the energization angle in step S44, the ECU 6 determines whether or not a second end time determined in advance from the timeout setting in step S22 in FIG. S49). The second end time is set longer than the first end time. If the second end time has not elapsed, the ECU 6 returns to the process of step S44. When the second end time has elapsed, the ECU 6 stops energizing the ignition coil (step S50), warns the driver that an abnormality has occurred in the engine unit EU (step S51), and performs engine start processing. finish.

Thus, in the second example, the reverse rotation of the crankshaft 13 is stopped based on the detection signal from the crank angle sensor 43 (steps S41 and S42). Further, energization to the ignition coil is stopped based on the detection signal from the crank angle sensor 43 (steps S44 and S45). Thereby, reverse rotation of the crankshaft 13 and energization to the ignition coil can be stopped at an appropriate timing.

Also, after the energization of the ignition coil is started in step S43, when the second end time has elapsed in step S39, the energization of the ignition coil is stopped in step S50. This prevents energization of the ignition coil from continuing for a long time.

(6) Effect In engine system 200 according to the present embodiment, fuel injection by injector 19 and ignition by spark plug 18 are prohibited during the forward rotation alignment operation. Thereby, in response to a detection signal (for example, a pulse signal) from the crank angle sensor 43, unintended combustion of the air-fuel mixture in the engine 10 is prevented. Accordingly, the crank angle can be appropriately adjusted to the reverse rotation start range before the engine 10 is started.

Thereafter, when the engine 10 is started, the engine unit EU performs a reverse rotation start operation. In this case, the crank angle surely passes through the starting intake air range. Therefore, the air-fuel mixture can be appropriately introduced into the combustion chamber 31a, and combustion of the air-fuel mixture can be appropriately caused in the combustion chamber 31a. Thereby, the torque in the positive direction of the crankshaft 13 is increased, and the crank angle can easily exceed the angle A2 corresponding to the first compression top dead center.

In the present embodiment, before the engine 10 is started, when the crankshaft 13 is rotated in the forward direction without being driven by the starter / generator 14, the fuel injection and ignition by the injector 19 are performed. Ignition by the plug 18 is not prohibited. As a result, when the crankshaft 13 is rotated in the forward direction by pushing or kicking, the engine 10 can be started by appropriately burning the air-fuel mixture. Further, since the fuel injection and ignition prohibition are controlled based on the operation of the starter / generator 14, the combustion of the air-fuel mixture during the forward rotation alignment operation is not required without requiring a complicated configuration and complicated control. Is prevented.

(7) Other embodiments (7-1)
In the above embodiment, both the fuel injection by the injector 19 and the ignition by the spark plug 18 are prohibited during the forward rotation alignment operation, but the present invention is not limited to this. By prohibiting ignition by the spark plug 18, the air-fuel mixture is prevented from being burned in the combustion chamber 31a. Therefore, the fuel injection by the injector 19 does not have to be prohibited during the forward rotation alignment operation. However, in order to appropriately adjust the air-fuel ratio in the combustion chamber 31a in the reverse rotation start operation and to prevent the unburned air-fuel mixture from being discharged from the combustion chamber 31a to the outside through the exhaust passage 24, the spark plug 18 It is preferable that fuel injection by the injector 19 is also prohibited together with ignition by

(7-2)
The above embodiment is an example in which the present invention is applied to the motorcycle 100 having the kick pedal KP, but the present invention may be applied to the motorcycle 100 having no kick pedal KP. In addition, the present invention may be applied not only to motorcycles but also to other saddle riding type vehicles such as an automatic tricycle or an ATV (All Terrain Vehicle).

(8) Correspondence between each constituent element of claim and each element of the embodiment Hereinafter, an example of correspondence between each constituent element of the claim and each element of the embodiment will be described. It is not limited to.

In the above embodiment, the engine unit EU is an example of an engine unit, the engine 10 is an example of an engine, the starter / generator 14 is an example of a rotational drive unit, the ECU 6 is an example of a control unit, and an injector 19 is an example of a fuel injection device, an ignition plug 18 is an example of an ignition device, a valve drive unit 17 is an example of a valve drive unit, an intake valve 15 is an example of an intake valve, and an exhaust valve 16 is an exhaust gas. It is an example of a valve, the main switch 40 is an example of a main switch, the starter switch 41 is an example of a starter switch, and the kick pedal KP is an example of a kick starter. The motorcycle 100 is an example of a saddle-ride type vehicle, the rear wheel 7 is an example of a driving wheel, and the vehicle body 1 is an example of a main body.

As the constituent elements of the claims, various other elements having configurations or functions described in the claims can be used.

The present invention can be effectively used for various engine systems and saddle riding type vehicles.

Claims (8)

An engine unit including an engine and a rotational drive unit;
A control unit for controlling the engine unit,
The engine is
A fuel injection device arranged to inject fuel into an intake passage for directing air to the combustion chamber;
An ignition device configured to ignite an air-fuel mixture in the combustion chamber;
An intake valve that opens and closes the intake port and an exhaust valve that drives the exhaust valve that opens and closes the exhaust port, and
The rotational drive unit is configured to rotationally drive the crankshaft in a forward direction or a reverse direction,
The controller performs a forward rotation alignment operation in which the crankshaft is rotated in the forward direction before starting the engine, and a reverse rotation start operation in which the crankshaft is rotated in the reverse direction when the engine is started. Control the engine unit to be performed,
The rotation drive unit drives the crankshaft so that the crank angle reaches a predetermined reverse rotation start range in the forward rotation alignment operation, and the crank angle rotates in the reverse rotation start operation. Driving the crankshaft to reach a predetermined start ignition range beyond a predetermined start intake range from a start range;
The valve drive unit drives the intake valve so that the intake port is opened when a crank angle is in the start intake range in the reverse rotation start operation,
In the reverse rotation start operation, the fuel injection device injects fuel so that an air-fuel mixture is introduced from the intake passage through the intake port into the combustion chamber when a crank angle is in the start intake range.
The ignition device ignites when the crank angle is in the start ignition range in the reverse rotation start operation,
The control unit is an engine system that prohibits ignition by the ignition device during the forward rotation alignment operation. The engine system according to claim 1, wherein the control unit prohibits fuel injection by the fuel injection device during the forward rotation alignment operation. It further includes a main switch operated by the driver,
The engine system according to claim 1, wherein the control unit controls the engine unit so that the forward rotation alignment operation is performed when the main switch is turned on. Further provided with a starter switch operated by the driver,
The engine system according to claim 1, wherein the control unit controls the engine unit so that the forward rotation alignment operation is performed when the starter switch is turned on. The control unit is configured to stop the operations of the fuel injection device and the ignition device and perform the forward rotation alignment operation after the crankshaft rotation is stopped when a predetermined idling stop condition is satisfied. 5. The engine unit is controlled to control the engine unit so that the reverse rotation start operation is performed when a predetermined idling stop release condition is satisfied. The engine system described in. The control unit does not prohibit ignition by the ignition device when the crankshaft rotates in the forward direction without being driven by the rotation driving unit before the engine is started. The ignition by the ignition device is prohibited when the crankshaft is rotated in the forward direction by being driven by the rotary drive unit before starting the engine. The engine system described in. A kick starter that is operated by a driver's foot to rotate the crankshaft in a positive direction;
The engine system according to any one of claims 1 to 6, wherein the control unit does not prohibit ignition by the ignition device when the crankshaft is rotated in a positive direction by an operation of the kick start unit by a driver. . A main body having a drive wheel;
A straddle-type vehicle comprising: the engine system according to any one of claims 1 to 7 that generates power for rotating the drive wheels.

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