WO2016152029A1

WO2016152029A1 - Engine system and saddle-type vehicle

Info

Publication number: WO2016152029A1
Application number: PCT/JP2016/001032
Authority: WO
Inventors: 裕生山口; 貴裕増田
Original assignee: ヤマハ発動機株式会社
Priority date: 2015-03-23
Filing date: 2016-02-26
Publication date: 2016-09-29
Also published as: TW201638462A

Abstract

Provided is an engine system in which when starting an engine, the human force of a user is applied to an input section of a manual start unit. A crankshaft rotates in a reverse direction as a result of human force being transmitted as torque to the crankshaft from a force transmission section of the manual start unit. Fuel that is injected by an injector is guided into a combustion chamber from an intake passage via an intake port as a result of an intake valve being driven during a period in which the crankshaft rotates in the reverse direction. An air-fuel mixture is subsequently ignited by a spark plug at a point in time at which a piston has not reached a compression top dead center and the air-fuel mixture is in a compressed state within the combustion chamber as a result of reverse rotation of the crankshaft. Torque from the crankshaft to the input section during forward rotation of the crankshaft is either blocked by the force transmission section or attenuated.

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.

A saddle-ride type vehicle such as a motorcycle equipped with an engine may be provided with a mechanism for starting the engine manually. Patent Document 1 describes a kick starter provided in a motorcycle. The kick starter includes a kick pedal for applying torque to the crankshaft of the engine. An occupant of the saddle riding type vehicle can start the engine by depressing the kick pedal.
JP 2012-67700 A

In the kick starter described in Patent Document 1, when starting the engine, the crank angle exceeds an angle corresponding to the first compression top dead center, and thus it is necessary to apply a large torque to the crankshaft. . Therefore, the occupant is required to step on the kick pedal with a very strong force. However, it is difficult for some occupants to step on the kick pedal with such a strong force that the crank angle exceeds the angle corresponding to the first compression top dead center.

Therefore, a torque that should be applied to the crankshaft when starting the engine can be reduced by providing a decompression mechanism (decompression mechanism) in the valve drive unit that opens the valve of the engine to reduce the pressure in the cylinder. Is possible. According to this configuration, the occupant can start the engine even when the kick pedal is depressed with a weaker force. However, if a decompression mechanism is provided in the valve drive unit, the valve drive unit becomes complicated.

An object of the present invention is to provide an engine system and a saddle-ride type vehicle that can easily start an engine by human power with a simple configuration.

(1) An engine system according to one aspect of the present invention includes an engine, a manual starter that is manually operated by a user to start the engine, and a control unit configured to control the engine. , Configured to drive a crankshaft rotatably provided in the forward or reverse direction, a fuel injection device disposed in the intake passage, an intake valve that opens and closes the intake port, and an exhaust valve that opens and closes the exhaust port A manual valve drive unit and an ignition device configured to ignite an air-fuel mixture in the combustion chamber. The manual start unit includes an input unit to which a user's human power is applied when starting the engine, and an input unit. A power transmission unit that transmits the generated human power to the crankshaft as a torque for rotating the crankshaft in the reverse direction. And the control unit drives the intake valve so that the fuel injected by is guided to the combustion chamber from the intake passage through the intake port at a first time point in the period in which the crankshaft is rotated in the reverse direction. After the fuel is introduced into the combustion chamber at the time, the air-fuel mixture is compressed in the combustion chamber due to the reverse rotation of the crankshaft, and the air-fuel mixture becomes the air-fuel mixture at the second time when the piston does not reach the compression top dead center. The ignition device is controlled to ignite, and the power transmission unit interrupts transmission of torque from the crankshaft to the input unit or rotates torque from the crankshaft to the input unit when the crankshaft rotates in the positive direction. Attenuate.

In this engine system, the user's human power is applied to the input part of the manual starting part when starting the engine. Human power applied to the input unit is transmitted as torque to the crankshaft by the power transmission unit of the manual starter. As a result, the crankshaft rotates in the reverse direction.

The intake valve is driven by the valve drive unit so that the fuel injected by the fuel injection device is guided from the intake passage through the intake port into the combustion chamber at a first time point during which the crankshaft is rotated in the reverse direction. . After the fuel is introduced into the combustion chamber at the first time point, at a second time point when the air-fuel mixture is compressed in the combustion chamber due to the reverse rotation of the crankshaft and the piston does not reach the compression top dead center. The mixture is ignited by the ignition device.

In this case, the piston is driven so that the crankshaft rotates in the positive direction by the energy of combustion generated in the combustion chamber. Thereby, sufficient torque in the positive direction is obtained, and the crank angle can easily exceed the angle corresponding to the first compression top dead center. Therefore, the engine can be started stably. Torque from the crankshaft to the input unit during rotation of the crankshaft in the positive direction is interrupted or attenuated by the power transmission unit. Therefore, after the engine is started, the rotation of the input unit due to the crankshaft torque can be prevented.

According to the above configuration, the engine can be easily started with weaker human power without providing a decompression mechanism (decompression mechanism) in the valve drive unit. Therefore, the configuration of the engine system can be simplified. As a result, the engine can be easily started manually with a simple configuration.

(2) The control unit may prohibit ignition of the air-fuel mixture of the ignition device when the rotational speed in the reverse direction of the crankshaft exceeds a predetermined threshold at the second time point.

When the crankshaft rotates in reverse and passes through the compression top dead center, when the human power is applied to the input of the manual starter, the reverse rotation speed of the crankshaft exceeds a predetermined threshold. There is. In this case, the piston is driven so that the crankshaft rotates in the reverse direction due to the combustion energy generated in the combustion chamber, and therefore the engine cannot be started properly.

According to the above configuration, when the reverse rotation speed of the crankshaft exceeds the threshold value, the mixture is not ignited at the second time point for the first time, and the second and subsequent rotation speeds are below the threshold value. The air-fuel mixture is ignited at the second time point. Therefore, even when a very large human power is applied to the manual starter, the engine can be appropriately started with a simple configuration.

(3) The power transmission unit may include a reverse input suppression function that transmits torque from the input unit to the crankshaft but limits torque transmitted from the crankshaft to the input unit.

In this case, the torque from the crankshaft to the input section when the crankshaft rotates in the positive direction can be cut off or attenuated with a simple configuration.

(4) The manual starting unit may include a kick starting unit, and the input unit may include a kick pedal.

In this case, the user can easily start the engine by depressing the kick pedal of the kick starting portion.

(5) The engine system further includes a motor that is provided on the crankshaft and is configured to be capable of rotationally driving the crankshaft in the forward direction, and the control unit causes the motor to move the crankshaft in the forward direction after the second time point. It may be driven.

In this case, a greater torque in the positive direction is obtained after the second time point by the motor. Thereby, the crank angle can more easily exceed the angle corresponding to the first compression top dead center. As a result, the engine can be started more easily.

(6) When the control unit detects that a predetermined start condition is satisfied, the motor may rotate the crankshaft in the reverse direction.

According to this configuration, when sufficient electric power remains in the engine system, the user can start the engine system more easily when a predetermined start condition is satisfied. On the other hand, when sufficient electric power does not remain in the engine system, the user can easily start the engine by applying human power to the input unit of the manual starting unit.

(7) The motor may include a rotating electric machine that can generate electric power by rotating the crankshaft after the engine is started.

In this case, electric power is generated by the rotation of the crankshaft after the engine is started. Therefore, it is possible to easily supply electric power for rotating the motor when the engine is started.

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

In this saddle-ride type vehicle, driving wheels are rotated by the power generated from the engine system. Thereby, a main-body part moves.

In the engine system, the user's human power is applied to the input part of the manual starting part when the engine is started. Human power applied to the input unit is transmitted as torque to the crankshaft by the power transmission unit of the manual starter. As a result, the crankshaft rotates in the reverse direction.

According to the present invention, the engine can be easily started manually with a simple configuration.

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 partially enlarged sectional view of the engine unit. FIG. 4 is an enlarged cross-sectional view for explaining the details of the power transmission unit. FIG. 5 is an enlarged cross-sectional view for explaining details of the power transmission unit. FIG. 6 is a schematic diagram for explaining the operation of the power transmission unit. FIG. 7 is a schematic diagram for explaining the operation of the power transmission unit. FIG. 8 is a diagram for explaining the normal operation of the engine unit. FIG. 9 is a diagram for explaining the reverse rotation start operation of the engine unit. FIG. 10 is a diagram for explaining engine starting in the reverse rotation starting operation. FIG. 11 is a flowchart of 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 system 200 is configured by the ECU 6 and the engine unit EU. 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, a rotating electrical machine 14, and a manual starter 500. The engine 10 includes a piston 11, a connecting rod (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. Hereinafter, the rotation direction of the crankshaft 13 during normal operation of the engine 10 is referred to as a forward direction, and the direction opposite to the forward direction is referred to as a reverse direction.

Rotating electric machine 14 is provided on the crankshaft 13. The rotating electrical machine 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 rotating electrical machine 14 transmits torque directly to the crankshaft 13 without using a reduction gear.

Also, a manual starter 500 is provided on the crankshaft 13. In the present embodiment, manual starter 500 is a kick starter and is kicked by the occupant when engine 10 is started. In this case, the occupant can easily start the engine 10 by depressing the kick pedal of the manual starter 500.

The manual starter 500 transmits the human power during the kick operation by the occupant as torque to the crankshaft 13 to drive the crankshaft 13 to rotate in the reverse direction. Details of the manual starter 500 will be described later. During normal operation of the engine 10, the forward rotation of the crankshaft 13 is transmitted to the rear wheel 7, so that the rear wheel 7 is rotationally driven.

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, a current sensor 44 and a temperature sensor 45 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 a passenger. 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 flowing through the rotating electrical machine 14 (hereinafter referred to as a motor current). The temperature sensor 45 detects, for example, the water temperature or oil temperature in the engine 10 or the machine temperature as a value corresponding to the temperature of the engine 10 (hereinafter referred to as engine temperature).

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, the current sensor 44 and the temperature sensor 45 are given to the ECU 6 as detection signals. The ECU 6 controls the rotating electrical machine 14, the spark plug 18, and the injector 19 based on the given operation signal and detection signal.

(3) Manual starter FIG. 3 is a partially enlarged sectional view of the engine unit EU. As shown in FIG. 3, the manual starting unit 500 includes an input unit 510, an arm unit 520, a shaft unit 530, a drive gear 540, a driven gear 550, and a power transmission unit 560. In this example, the input unit 510 is a kick pedal. The shaft portion 530 extends in parallel with the rotation center line RC of the crankshaft 13 and is fixed to the casing 210 of the engine unit EU so as to be rotatable. One end portion of the shaft portion 530 protrudes outward of the casing 210.

The input unit 510 and one end of the shaft unit 530 are connected by an arm unit 520. Drive gear 540 is provided at the other end of shaft portion 530. The drive gear 540 is engaged with the driven gear 550 while being urged in one direction by an urging member (not shown). The driven gear 550 has a cylindrical portion 551. The crankshaft 13 is inserted into the cylindrical portion 551. Between the inner peripheral surface of the cylindrical portion 551 and the outer peripheral surface of the crankshaft 13, a power transmission portion 560 and a bearing B1 are disposed.

The power transmission unit 560 transmits torque from the input unit 510 to the crankshaft 13, but includes a reverse input suppression function that limits the torque transmitted from the crankshaft 13 to the input unit 510. The power transmission unit 560 is, for example, a clutch mechanism. In this example, the power transmission unit 560 is a two-way clutch, but the present invention is not limited to this. The power transmission unit 560 may be a clutch mechanism having a torque diode, a torque limiter, or another damper mechanism.

When the engine 10 is started, the passenger kicks the input unit 510. The human power of the kick operation by the occupant is transmitted to the shaft portion 530 through the arm portion 520 as torque for rotating the shaft portion 530. In this case, the drive gear 540 rotates against a biasing force of a biasing member (not shown). The torque of drive gear 540 is transmitted to driven gear 550. As a result, the driven gear 550 rotates around the rotation center line RC of the crankshaft 13.

When the engine 10 is started, the torque of the driven gear 550 is transmitted to the crankshaft 13 by the power transmission unit 560. As a result, the crankshaft 13 rotates in the reverse direction around the rotation center line RC. On the other hand, during normal operation of engine 10, torque transmission from crankshaft 13 rotating in the forward direction to driven gear 550 is interrupted or attenuated by power transmission unit 560. Hereinafter, the details of the power transmission unit 560 will be described.

(4) Details of Power Transmission Unit FIGS. 4 and 5 are enlarged cross-sectional views for explaining details of the power transmission unit 560. In the following description, the radial direction of the crankshaft 13 centered on the rotation center line RC is referred to as an axial radial direction, and the circumferential direction of the crankshaft 13 centered on the rotation centerline RC is referred to as an axial circumferential direction. A direction away from the rotation center line RC in the axial radial direction is referred to as a radially outward direction. As shown in FIG. 4, the power transmission unit 560 includes a fixed plate 561, a roller holding unit 562, an urging member 563, and a plurality of (eight in the example of FIG. 5) rollers 564. FIG. 4 shows only one of the plurality of rollers 564.

The fixed plate 561 has a pressing part 561a and a protruding part 561b. The pressing portion 561a has an annular shape and is provided on the outer side in the radial direction of the crankshaft 13. The protruding portion 561b is provided so as to protrude radially outward from the outer peripheral portion of the pressing portion 561a and bend at a right angle. The tip of the protruding portion 561b is fixed to a plate fixing portion 211 provided in the casing 210.

The roller holding part 562 has a cylindrical part 562a, a flange part 562b, and a sliding part 562c. The cylindrical portion 562a is provided so as to surround a part of the outer peripheral surface of the crankshaft 13. A cylindrical sliding bearing SB is fixed to the inner peripheral surface of the cylindrical portion 562a. An oil supply path OS is formed in the portion of the crankshaft 13 where the sliding bearing SB overlaps. Lubricating oil is supplied between the inner peripheral surface of the sliding bearing SB and the outer peripheral surface of the crankshaft 13 through the oil supply path OS. By the sliding bearing SB, the slipping property between the roller holding portion 562 and the crankshaft 13 is ensured.

A part of the cylindrical portion 562a is disposed inside the cylindrical portion 551 of the driven gear 550. A bearing B2 is disposed between the cylindrical portion 562a and the cylindrical portion 551 of the driven gear 550. The roller holding part 562 and the driven gear 550 are relatively rotatable in the axial circumferential direction via the bearing B2.

The flange portion 562b is provided outside the cylindrical portion 551 of the driven gear 550 so as to protrude radially outward from one end portion of the cylindrical portion 562a. The sliding portion 562c is provided so as to protrude radially outward from the outer peripheral surface of the cylindrical portion 562a with a certain distance from the flange portion 52a.

Between the flange part 562b and the sliding part 562c, the pressing part 561a of the fixed plate 561 is disposed so as to come into contact with the sliding part 562c. Further, an urging member 563 is disposed between the pressing portion 561a and the flange portion 562b. The biasing member 563 is, for example, a wave spring. The pressing portion 561a is urged by the urging member 563 so as to be pressed against the sliding portion 562c.

As shown in FIG. 5, the cross section of the inner peripheral surface of the cylindrical portion 551 of the driven gear 550 is polygonal. The inner peripheral surface of the cylindrical portion 551 is composed of a plurality of flat surfaces (hereinafter referred to as cam surfaces) CF. In this example, the cross section of the inner peripheral surface of the cylindrical portion 551 is a regular octagonal shape, and the inner peripheral surface of the cylindrical portion 551 is configured by eight cam surfaces CF. In the cylindrical portion 551, a plurality of notches CT are formed at equal angular intervals in the axial direction in the cylindrical portion 562a of the roller holding portion 562.

Between the inner peripheral surface of the cylindrical portion 551 of the driven gear 550 and the outer peripheral surface of the crankshaft 13, a roller 564 having a substantially columnar shape is disposed in each notch CT. The width of each notch CT in the axial circumferential direction is slightly larger than the diameter DA of the cross section of the roller 564.

In the axial direction, the maximum distance D1 between the outer peripheral surface of the crankshaft 13 and the inner peripheral surface of the cylindrical portion 551 is larger than the diameter DA of the cross section of the roller 564. The maximum distance D1 is a distance in the axial diameter direction between the end of each cam surface CF and the outer peripheral surface of the crankshaft 13. On the other hand, in the axial direction, the minimum distance D2 between the outer peripheral surface of the crankshaft 13 and the inner peripheral surface of the cylindrical portion 551 is smaller than the diameter of the cross section of the roller 564. The minimum distance D <b> 2 is a distance in the axial diameter direction between the center portion of each cam surface CF and the outer peripheral surface of the crankshaft 13.

Thus, the roller 564 does not pass between the center portion of each cam surface CF and the outer peripheral surface of the crankshaft 13, and the movement range in the axial direction of each roller 564 with respect to the cylindrical portion 551 is limited. Accordingly, each roller 564 moves in the axial direction in conjunction with the rotation of the cylindrical portion 551 in the axial direction.

(5) Action of Clutch Mechanism FIGS. 6 and 7 are schematic diagrams for explaining the action of the power transmission unit 560. 6 and 7 show one roller 564 and a cylindrical portion 551, a roller holding portion 562, and a part of the crankshaft 13. The other rollers 564 operate in the same manner as the rollers 564 of FIGS. In the following description, the rotational speed of the driven gear 550 and the rotational speed of the crankshaft 13 when it is assumed that torque is not transmitted between the driven gear 550 and the crankshaft 13 are referred to as an input rotational speed and an output rotational speed, respectively.

1 before starting the engine 10, as shown in FIG. 6A, the rollers 564 are separated from the crankshaft 13. Therefore, power transmission unit 560 is in a disconnected state. When the engine 10 is started, the occupant kicks the input unit 510 shown in FIG. 3 to rotate the driven gear 550 in the reverse direction DR2 as shown in FIG. 6B. Accordingly, each roller 564 moves in the reverse direction DR2 while being in contact with the cam surface CF of the driven gear 550 and the outer peripheral surface of the crankshaft 13. In this case, each roller 564 pushes the roller holding portion 562, and the roller holding portion 562 rotates in the reverse direction DR2.

As described above, the pressing portion 561a (FIG. 4) of the fixed plate 561 is pressed against the sliding portion 562c (FIG. 4) of the roller holding portion 562 by the biasing member 563 (FIG. 4). For this reason, when the roller holding portion 562 rotates, friction is generated between the pressing portion 561a and the sliding portion 562c. The friction force acts as a rotation resistance of the roller holding portion 562. Accordingly, a drag force in the positive direction DR1 acts on the roller 564 from the roller holding portion 562, and the roller 564 is held in a state of being pressed against the cam surface CF and the outer peripheral surface of the crankshaft 13. In this case, the crankshaft 13 is prohibited from rotating in the positive direction DR1 with respect to the driven gear 550. On the other hand, the rotation of the crankshaft 13 in the reverse direction DR2 with respect to the driven gear 550 is not prohibited.

As shown in FIG. 6C, when the output rotational speed in the reverse direction DR2 of the crankshaft 13 is lower than the input rotational speed in the reverse direction DR2 of the driven gear 550, the power transmission unit 560 is connected. In this case, the torque in the reverse direction DR2 of the driven gear 550 is transmitted to the crankshaft 13, and the crankshaft 13 rotates integrally with the driven gear 550 in the reverse direction DR2.

As shown in FIG. 7A, when the output rotational speed in the reverse direction DR2 of the crankshaft 13 becomes higher than the input rotational speed in the reverse direction DR2 of the driven gear 550 due to inertia, the power transmission unit 560 is in an idling state. In this case, torque is not transmitted between the driven gear 550 and the crankshaft 13, and the crankshaft 13 rotates in the reverse direction DR2 at a higher rotational speed than the driven gear 550 while the driven gear 550 rotates in the reverse direction DR2.

After the kick operation by the occupant, when the rotation due to the inertia stops, as shown in FIG. 7B, the rotation of the driven gear 550 stops and the rotation of the roller 564 and the roller holding portion 562 also stops. In this case, the holding of the roller 564 by the roller holding unit 562 is released. As a result, the power transmission unit 560 is disconnected, and the crankshaft 13 rotates in the reverse direction DR2 without being subjected to rotational resistance by the driven gear 550.

As will be described later, after the crankshaft 13 rotates by a predetermined angle, the rotation direction of the crankshaft 13 is switched from the reverse direction DR2 to the forward direction DR1. Even in this case, since the power transmission unit 560 is in a disconnected state, the torque of the crankshaft 13 is not transmitted to the driven gear 550. Therefore, the crankshaft 13 rotates in the positive direction DR1 in a state where torque transmission from the crankshaft 13 to the input unit 510 (FIG. 3) is interrupted.

(6) Engine Operation For example, the engine 10 is started by turning on the starter switch 41 in FIG. 2 or kicking the input unit 510 with the main switch 40 in FIG. 2 turned on. . Further, the engine 10 is stopped by turning off the main switch 40 of FIG. 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 related to at least one of a throttle opening (opening of the throttle valve TV), a vehicle speed, and a rotation 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 reverse rotation starting operation when the engine 10 is started. Thereafter, the engine unit EU performs a normal operation. FIG. 8 is a diagram for explaining a normal operation of the engine unit EU. FIG. 9 is a diagram for explaining 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.

8 and 9, 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).

8 and 9, 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.

Hereinafter, rotation of the crankshaft 13 in the forward direction is referred to as forward rotation, and rotation of the crankshaft 13 in the reverse direction is referred to as reverse rotation. Arrow R1 indicates the direction of change in the crank angle when the crankshaft 13 rotates forward, and arrow R2 indicates the direction of change in the crank angle when the crankshaft 13 rotates 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.

(A) 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 forward. Therefore, the crank angle changes in the direction of arrow R1. In this case, as indicated by the arrow P1, the piston 11 (FIG. 2) descends in the range from the angle A0 to the angle A1. Next, as indicated by the arrow P2, the piston 11 rises in the range from the angle A1 to the angle A2. Subsequently, as indicated by the arrow P3, the piston 11 is lowered in the range from the angle A2 to the angle A3. Thereafter, as indicated by the arrow P4, 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, combustion 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.

(B) Reverse rotation start operation FIGS. 10A and 10B are diagrams for explaining the start of the engine 10 in the reverse rotation start operation. 10A and 10B, the horizontal axis indicates the crank angle, and the vertical axis indicates the rotational load of the crankshaft 13. The reverse rotation starting operation of the engine unit EU will be described with reference to FIGS. 9 and 10 (a) and 10 (b).

In this example, before the reverse rotation start operation is performed, the crank angle is adjusted to a predetermined reverse rotation start range. The reverse rotation start range is, for example, in the range from angle A0 to angle A2 in the positive direction, and preferably in the range from angle A13 to angle A2. In FIG. 9, the reverse rotation start range is an angle A30. The angle A30 is in the range from the angle A13 to the angle A2.

In the reverse rotation start operation, the occupant performs a kick operation of the input unit 510 in FIG. 3 or an operation for satisfying a predetermined start condition while the crank angle is in the reverse rotation start range. Thereby, the crankshaft 13 is rotated in the reverse direction by the rotating electrical machine 14 or the manual starter 500 in FIG. 2, and the crank angle changes in the direction of the arrow R2 in FIG.

In this case, as indicated by the arrow P6, the piston 11 is lowered in the range from the angle A2 to the angle A1. Next, as indicated by the arrow P5, the piston 11 rises in the range from the angle A1 to the angle A0. Subsequently, as indicated by an arrow P8, the piston 11 is lowered in the range from the angle A0 to the angle A3. Thereafter, as indicated by an arrow P7, 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.

As shown in FIGS. 10A and 10B, the rotational load on the crankshaft 13 is maximized at an angle A2 corresponding to the compression top dead center. Further, between the angle A1 and the angle A0, the rotational load on the crankshaft 13 increases due to the drive of the intake valve 15. Further, between the angle A0 and the angle A3, the rotational load on the crankshaft 13 increases due to the drive of the exhaust valve 16.

In this example, even when the crankshaft 13 rotates in the reverse direction, the intake port 21 is opened in the range from the angle A13 to the angle A12 in FIG. 9 and exhausted in the range from the angle A16 to A15 as in the forward rotation. Mouth 23 is opened. However, at the time of 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. .

As shown in FIG. 9, at an 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.

In the range from the angle A1 to the angle A0, the piston 11 rises, so 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, when the rotational speed in the reverse direction of the crankshaft 13 is equal to or less than a predetermined threshold value at the angle A31a, energization to the ignition coil connected to the ignition plug 18 (FIG. 2) is started. The After that, at the angle A31, by stopping energization to the ignition coil, the air-fuel mixture in the combustion chamber 31a is ignited by the spark plug 18 (FIG. 2). 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.

In this way, torque in the positive direction due to combustion is obtained. Accordingly, the crank angle can more easily exceed the angle corresponding to the first compression top dead center in the forward rotation. As a result, the engine 10 can be started more easily. Thereafter, the engine 10 shifts to the normal operation of FIG.

On the other hand, when the rotational speed of the crankshaft 13 in the reverse direction exceeds the threshold value at the angle A31a, the piston 11 (FIG. 2) performs the first compression top dead in the reverse rotation with the crankshaft 13 rotating in the reverse direction. The point will be passed. In this case, the piston 11 is driven so that the crankshaft 13 rotates in the reverse direction by the energy of combustion generated in the combustion chamber 31a, and the piston 11 is not driven so that the crankshaft 13 rotates in the forward direction. Therefore, the engine 10 cannot be started properly. Therefore, when the reverse rotation speed of the crankshaft 13 exceeds the threshold value, energization of the ignition coil is prohibited and ignition of the air-fuel mixture is not performed.

In this case, as shown in FIG. 10 (b), the crankshaft 13 is further reversely rotated by 720 degrees or more, and the ignition coil is turned on at an angle A31a after the second time when the rotational speed of the crankshaft 13 is below the threshold value. Is started, and the current supply to the ignition coil is stopped at the angle A31, whereby the mixture in the combustion chamber 31a is ignited by the ignition plug 18 (FIG. 2). Thereby, even when a very large human power is applied to the manual starter 500, the engine 10 can be appropriately started with a simple configuration.

Thus, 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 manual starter 500 or the rotating electrical machine 14. Thereafter, the air-fuel mixture in the combustion chamber 31a is ignited with the piston 11 approaching the compression top dead center. Thereby, the piston 11 is driven so that the crankshaft 13 rotates forward.

In the present embodiment, at the same time as the reverse rotation of the crankshaft 13 is stopped, the air-fuel mixture in the combustion chamber 31a is ignited by the spark plug 18, but the crankshaft 13 can be driven in the forward direction. If there is, the stop of the reverse rotation of the crankshaft 13 and the ignition by the spark plug 18 may not be simultaneous.

(7) Engine start process ECU6 performs an engine start process based on the control program previously memorize | stored in memory. FIG. 11 is a flowchart of the engine start process. The engine start process is performed, for example, when the main switch 40 (FIG. 2) is turned on or when the engine 10 shifts to an idle stop state.

As shown in FIG. 11, the ECU 6 determines whether or not a predetermined start condition is satisfied (step S1). When the engine unit EU is not in the idle stop state, the start condition is, for example, that the starter switch 41 (FIG. 2) is turned on. When the engine unit EU is in the idle stop state, the start condition is that the idle stop release condition is satisfied.

Even if the start condition is not satisfied, the occupant can start the engine 10 by kicking the input unit 510 of FIG. Therefore, when the start condition is not satisfied in step S1, the ECU 6 proceeds to the process of step S3. On the other hand, when the starting condition is satisfied in step S1, the ECU 6 controls the rotating electrical machine 14 so that the crankshaft 13 is rotated in the reverse direction (step S2).

When the crank angle is not in the reverse rotation start range (angle A30) at the start of the engine start process, the crank angle is adjusted to the reverse rotation start range before the crankshaft 13 is reversely rotated.

Next, the ECU 6 determines whether or not the crankshaft 13 has rotated in the reverse direction (step S3). The fact that the crankshaft 13 is not rotating reversely means that the starting condition is not satisfied in step S1, or that the kick operation of the input unit 510 is not performed. Therefore, if the crankshaft 13 is not rotating in reverse in step S3, the ECU 6 returns to the process in step S1. Thus, ECU 6 repeats the processes of steps S1 to S3 until the starting condition is satisfied in step S1 or the input unit 510 is kicked.

When the crankshaft 13 rotates in the reverse direction in step S3, the ECU 6 determines whether or not the fuel injection condition is satisfied (step S4). For example, the fuel injection condition is that the crank angle obtained from the detection results of the intake pressure sensor 42 (FIG. 2) and the crank angle sensor 43 (FIG. 2) reaches the angle A23 in FIG. If the fuel injection condition is not satisfied, the ECU 6 repeats the process of step S4.

When the fuel injection condition is satisfied in step S4, the ECU 6 controls the injector 19 (FIG. 2) so that the fuel is injected into the intake passage 22 (FIG. 2) (step S5). In this case, the ECU 6 may control the injector 19 in response to a pulse signal from the crank angle sensor 43.

Next, the ECU 6 determines whether or not the ignition condition is satisfied (step S6). For example, the ignition condition is that the crank angle obtained from the detection results of the intake pressure sensor 42 (FIG. 2) and the crank angle sensor 43 (FIG. 2) reaches the angle A31a in FIG. If the ignition condition is not satisfied, the ECU 6 repeats the process of step S6.

When the ignition condition is satisfied in step S6, the ECU 6 determines whether or not the rotational speed of the crankshaft 13 is equal to or less than a threshold value (step S7). If the rotational speed of the crankshaft 13 exceeds the threshold value in step S7, the ECU 6 returns to the process in step S6. The ECU 6 repeats the processes of steps S6 and S7 until the rotational speed of the crankshaft 13 becomes equal to or less than the threshold value.

If the rotational speed of the crankshaft 13 is equal to or lower than the threshold value in step S7, the ECU 6 performs ignition by energizing the ignition coil (step S8). In this case, the ECU 6 may control the ignition coil in response to the pulse signal from the crank angle sensor 43. Thereafter, the ECU 6 controls the rotating electrical machine 14 so that the crankshaft 13 is rotated in the forward direction (step S9). As a result, the engine start process ends.

According to the engine start process of FIG. 11, when sufficient electric power remains in the engine system 200, the occupant can start the engine system 200 more easily when a predetermined start condition is satisfied. it can. On the other hand, when sufficient electric power does not remain in the engine system 200, the occupant can easily start the engine 10 by applying human power to the input unit 510 of the manual starting unit 500.

(8) Effect In the engine system 200 according to the present embodiment, the user's human power is applied to the input unit 510 of the manual starter 500 when the engine 10 is started. The human power applied to the input unit 510 is transmitted as torque to the crankshaft 13 by the power transmission unit 560 of the manual start unit 500. Thereby, the crankshaft 13 rotates in the reverse direction.

During the period in which the crankshaft 13 is rotated in the reverse direction, the fuel injected by the injector 19 is guided from the intake passage 22 through the intake port 21 into the combustion chamber 31a. Thereafter, when the air-fuel mixture is compressed in the combustion chamber 31a due to the reverse rotation of the crankshaft 13 and the piston 11 does not reach the compression top dead center, the air-fuel mixture is ignited by the spark plug 18.

In this case, the piston 11 is driven by the energy of combustion generated in the combustion chamber 31a so that the crankshaft 13 rotates in the forward direction. Thereby, sufficient torque in the positive direction is obtained, and the crank angle can easily exceed the angle corresponding to the first compression top dead center. Therefore, the engine 10 can be started stably. Torque from the crankshaft 13 to the input unit 510 when the crankshaft 13 rotates in the positive direction is interrupted or attenuated by the power transmission unit 560. Therefore, after the engine 10 is started, the rotation of the input unit 510 due to the torque of the crankshaft 13 can be prevented.

According to the above configuration, the engine 10 can be easily started with weaker human power without providing a decompression mechanism (decompression mechanism) in the valve drive unit 17. Therefore, the configuration of engine system 200 can be simplified. As a result, the engine 10 can be easily started manually with a simple configuration.

(9) Other Embodiments (a) In the above embodiment, the manual starter 500 is a kick starter having a kick pedal, but the present invention is not limited to this. The manual starter 500 may be a recoil starter. In this case, the user can start the recoil starter by pulling the starter rope as an input unit and rotating the crankshaft. Manual starter 500 may be another type of starter that can start the engine manually.

(B) In the above embodiment, the engine system 200 includes the rotating electrical machine 14, but the present invention is not limited to this. The engine system 200 may include a starter motor and a generator separately in place of the rotating electrical machine 14, or may include one of a starter motor and a generator. Alternatively, the engine system 200 may not include any of the rotating electrical machine 14, the starter motor, and the generator.

(C) The above embodiment is an example in which the present invention is applied to a motorcycle. However, the present invention is not limited to this, and other saddle-type vehicles such as a motorcycle or an ATV (All Terrain Vehicle) are used. The present invention may be applied.

(10) Correspondence between each component of claim and each part of embodiment The following describes an example of a correspondence between each component of the claim and each element of the embodiment. It is not limited to.

In the above embodiment, the engine 10 is an example of an engine, the manual starter 500 is an example of a manual starter and a kick starter, the ECU 6 is an example of a controller, and the crankshaft 13 is an example of a crankshaft. is there. The intake passage 22 is an example of an intake passage, the injector 19 is an example of a fuel injection device, the intake port 21 is an example of an intake port, the intake valve 15 is an example of an intake valve, and the exhaust port 23 is an exhaust port. The exhaust valve 16 is an example of an exhaust valve.

The valve drive unit 17 is an example of a valve drive unit, the spark plug 18 is an example of an ignition device, the input unit 510 is an example of an input unit and a kick pedal, and the power transmission unit 560 is an example of a power transmission unit. Piston 11 is an example of a piston. The engine system 200 is an example of an engine system, the rotating electrical machine 14 is an example of a motor and a rotating electrical machine, the rear wheel 7 is an example of a driving wheel, the vehicle body 1 is an example of a main body, and the motorcycle 100 is a vehicle. It is an example of a riding type vehicle.

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

An engine,
A manual starter manually operated by a user to start the engine;
A control unit configured to control the engine,
The engine is
A crankshaft provided rotatably in the forward or reverse direction;
A fuel injection device disposed in the intake passage;
A valve drive unit configured to drive an intake valve that opens and closes the intake port and an exhaust valve that opens and closes the exhaust port; and
An igniter configured to ignite the air-fuel mixture in the combustion chamber,
The manual starter is
An input unit to which a user's human power is applied when starting the engine;
A power transmission unit that transmits human force applied to the input unit to the crankshaft as torque for rotating the crankshaft in the reverse direction;
The valve drive unit guides the fuel injected by the fuel injection device into the combustion chamber from the intake passage through the intake port at a first time point in a period in which the crankshaft is rotated in the reverse direction. Drive the intake valve so that
After the fuel is introduced into the combustion chamber at the first time point, the control unit is in a state where the air-fuel mixture is compressed in the combustion chamber by the rotation of the crankshaft in the reverse direction and the piston is compressed. Controlling the igniter to ignite the air-fuel mixture at a second time when the dead center is not reached,
The power transmission unit interrupts transmission of torque from the crankshaft to the input unit or attenuates torque from the crankshaft to the input unit during rotation of the crankshaft in the positive direction; Engine system.
The control unit prohibits ignition of the air-fuel mixture of the ignition device when the reverse rotation speed of the crankshaft exceeds a predetermined threshold at the second time point. The engine system described.
The said power transmission part contains the reverse input suppression function in which the torque transmitted from the said input part to a crankshaft is transmitted, but the torque transmitted from the said crankshaft to the said input part is restrict | limited. Engine system.
The manual starter includes a kick starter,
The engine system according to any one of claims 1 to 3, wherein the input unit includes a kick pedal.
A motor provided on the crankshaft and configured to be able to rotate the crankshaft in a positive direction;
The engine system according to any one of claims 1 to 4, wherein the control unit drives the crankshaft in the forward direction by the motor after the second time point.
The engine system according to claim 5, wherein the motor rotates the crankshaft in the reverse direction when the control unit detects that a predetermined start condition is satisfied.
The engine system according to claim 5 or 6, wherein the motor includes a rotating electrical machine capable of generating electric power by rotation of the crankshaft after the engine is started.
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.