JP2017036665A - Engine unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine unit capable of restarting an engine in a shorter time while avoiding increase in size of a rotary electrical machine.SOLUTION: An engine unit mounted to a vehicle, comprises a four-stroke engine body, a rotary electrical machine configured to be able to rotate a crankshaft while receiving supply of electric power from a battery equipped on the vehicle and to be able to charge the battery by electric power generation associated with rotation of the crankshaft, an inverter for controlling an electric current flowing between the battery and the rotary electrical machine, and a control device controlling the inverter, the rotary electrical machine and the four-stroke engine body. The control device, after combustion of the engine is stopped, by executing vector control to the rotary electrical machine according to the rotation speed of the crankshaft and the position of the crankshaft, controls rotation of the crankshaft to stop the rotation of the crankshaft.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an engine unit.

  The engine unit is mounted on a vehicle such as a motorcycle. The engine unit includes, for example, a rotating electrical machine that functions as a motor and a generator.

  Such a rotating electrical machine functions as a starter motor when the engine is started. The rotating electrical machine is driven by a battery provided in the vehicle when the engine is started, and rotates the crankshaft to start the engine. When the engine is started, the rotational resistance of the crankshaft in the compression stroke increases as the gas in the cylinder is compressed in the compression stroke. Accordingly, the rotating electrical machine must rotate the crankshaft over the high load region of the compression stroke.

  Further, since the rotating electrical machine is mounted on a vehicle such as a motorcycle, it must be suitable for mounting on the vehicle. Specifically, the rotating electrical machine must be a size suitable for mounting on a vehicle, for example. From the viewpoint of vehicle mountability and running performance, the rotating electrical machine is desirably small.

  However, normally, when the rotating electrical machine is downsized, the output torque of the rotating electrical machine decreases. This makes it difficult to start the engine quickly. This is undesirable for a vehicle that restarts the engine after it has been stopped. Therefore, a vehicle that restarts the engine after stopping the engine requires both a reduction in the size of the rotating electrical machine and a reduction in the time required to restart the engine.

  Patent Document 1 discloses an engine start control device that reduces the size of the starter motor and shortens the restart time of the engine after the combustion of the engine is stopped.

JP 2004-124878 A

  However, it has been difficult for the engine start control device of Patent Document 1 to realize a sufficiently short engine restart while avoiding an increase in the size of the rotating electrical machine.

  The present invention has been made in view of the above-described problems. An object of the present invention is to provide an engine unit that can restart an engine in a shorter time while avoiding an increase in size of a rotating electrical machine.

The present invention employs the following configuration in order to solve the above-described problems.
(1) An engine unit mounted on a vehicle,
The engine unit is
It has a high load region and a low load region during four strokes in a combustion stop state, and the load for rotating the crankshaft in the high load region is larger than the load for rotating the crankshaft in the low load region A 4-stroke engine body,
A rotating electrical machine configured to receive power from a battery included in the vehicle to rotate the crankshaft, and to be able to charge the battery by power generation accompanying rotation of the crankshaft;
An inverter for controlling a current flowing between the battery and the rotating electrical machine;
A control device for controlling the inverter, the rotating electrical machine, and the 4-stroke engine main body;
The control device controls the rotation of the crankshaft by performing vector control on the rotating electrical machine according to the rotational speed of the crankshaft and the position of the crankshaft after the combustion of the four-stroke engine main body is stopped. To stop the rotation of the crankshaft.

  According to the configuration of (1), the control device performs, for example, control for accelerating the rotation of the crankshaft or control for imparting resistance to the rotation of the crankshaft according to the rotational speed of the crankshaft and the position of the crankshaft. According to the vector control, the degree of acceleration or resistance can be controlled according to the rotational speed of the crankshaft and the position of the crankshaft. As a result, the crankshaft can be stopped at a position suitable for shortening the time taken until the four-stroke engine body is restarted. Therefore, it is possible to shorten the time from when the crankshaft is stopped to when the stroke engine body is restarted. Here, the rotation of the crankshaft when the engine is restarted may be performed from the stop position of the crankshaft before the engine is restarted. Further, the rotation of the crankshaft when the engine is restarted may be performed from a position after the crankshaft further moves from the stop position. In any case, according to the configuration of (1), the crankshaft can be stopped at a position suitable for reducing the time required for restarting. Therefore, according to the configuration of (1), the time from the engine combustion stop to the engine restart can be shortened without requiring an increase in the size of the rotating electrical machine.

  The vector control performed on the rotating electrical machine according to the rotational speed of the crankshaft and the position of the crankshaft is not particularly limited, but may be performed as follows, for example. The control device determines the control content of the rotation of the crankshaft according to the rotational speed of the crankshaft and the position of the crankshaft at the time of starting vector control. After determining the control content, the control device controls the rotation of the crankshaft by open loop control based on the determined control content, and stops the rotation of the crankshaft.

  Further, the vector control may be performed as follows, for example. The control device performs feedback control in accordance with the rotation speed of the crankshaft and the position of the crankshaft during the period of vector control. In this case, the control device changes the control content according to the rotational speed of the crankshaft and the position of the crankshaft, controls the rotation of the crankshaft based on the changed control content, and stops the rotation of the crankshaft. Let Further, feedback control may be performed during a part of the period during which the vector control is performed, and open loop control may be performed during the remaining period.

  Further, the control of the rotation of the crankshaft by the vector control may be performed in at least a part of a period after the combustion of the 4-stroke engine main body is stopped until the rotation of the crankshaft is stopped. For example, in a vehicle in which the lower limit value of the crankshaft rotation speed and the crankshaft rotation speed at which the crankshaft position can be detected exceeds 0 (rpm), the crankshaft rotation by vector control is performed during the following period. Also good. That is, at least part of the period from when the combustion of the engine is stopped until at least one of the crankshaft rotational speed and the crankshaft position is not detected as the crankshaft rotational speed decreases, The shaft may be rotated. In this case, during the period from when at least one of the rotation speed of the crankshaft and the position of the crankshaft is not detected until the rotation of the crankshaft is stopped, the rotation of the crankshaft by vector control is not performed. Good.

  The control of the rotation of the crankshaft includes, for example, at least one of a control for accelerating the rotation of the crankshaft and a control for imparting resistance to the rotation of the crankshaft. In the control of the rotation of the crankshaft, at least one of the control for accelerating the rotation of the crankshaft and the control for imparting resistance to the rotation of the crankshaft may be performed. For example, both control for imparting resistance to rotation of the crankshaft and control for accelerating the rotation of the crankshaft may be performed during a period in which the rotation of the crankshaft is controlled. Further, only control for accelerating the rotation of the crankshaft may be performed. In this case, for example, after the control for accelerating the rotation of the crankshaft is performed, the inertial rotation of the crankshaft is performed until the rotation of the crankshaft is stopped. Even in such an aspect, according to the configuration of (1) above, the rotation of the crankshaft is controlled by vector control according to the rotational speed of the crankshaft and the position of the crankshaft. The crankshaft can be accurately stopped at a position suitable for shortening the time. As a result, the time required for restart can be shortened. However, in the control of the rotation of the crankshaft, it is preferable that at least control for imparting resistance to the rotation of the crankshaft is performed. This is because the crankshaft can be stopped accurately and in a short time at a position suitable for shortening the time required for restarting.

  The acceleration of crankshaft rotation will be described. The rotation of the crankshaft is temporarily continued by inertia after the combustion of the 4-stroke engine is stopped. The rotational speed of the crankshaft gradually decreases during the period in which the crankshaft continues to rotate. The acceleration of the rotation of the crankshaft means that the rotation of the crankshaft is relatively accelerated as compared to the gradually decreasing rotation speed of the crankshaft. Therefore, the control for suppressing the decrease in the rotation speed of the crankshaft, that is, the control for reducing the amount of decrease in the rotation speed of the crankshaft corresponds to the control for accelerating the rotation of the crankshaft. Further, the control for maintaining the rotation speed of the crankshaft so that the amount of decrease in the rotation speed of the crankshaft is 0 or substantially 0 corresponds to the control for accelerating the rotation of the crankshaft. The control for increasing the rotation speed of the crankshaft also corresponds to the control for accelerating the rotation of the crankshaft.

  The application of resistance to the rotation of the crankshaft is control for promoting a decrease in the rotation of the crankshaft, that is, a control for increasing the amount of decrease in the rotation speed of the crankshaft. In the preferred embodiment of (1) above, the application of resistance to rotation of the crankshaft is performed such that a period during which electric power is supplied from the power storage unit to the rotating electrical machine occurs. As a result, the braking force can be further increased and the time required for restarting is further shortened. The power storage unit includes a battery and a capacitor provided between the battery and the inverter.

  In the preferred embodiment of the above (1), the application of the resistance to the rotation of the crankshaft is performed so that, for example, a period in which the rotating electrical machine generates power and charges the battery is generated. Thereby, the time required for restart is shortened while suppressing power consumption.

  ADVANTAGE OF THE INVENTION According to this invention, the engine unit which can perform engine restart in a shorter time can be provided, avoiding the enlargement of a rotary electric machine.

1 is a partial cross-sectional view schematically showing a schematic configuration of an air-cooled engine unit according to a first embodiment of the present invention. It is explanatory drawing which shows typically the relationship between the crank angle position at the time of engine starting, and required torque. It is the expanded sectional view which expanded and showed the rotary electric machine in FIG. 1, and its vicinity part. It is sectional drawing which shows a cross section perpendicular | vertical to the rotating shaft line of the rotary electric machine shown in FIG. It is a block diagram which shows the electrical basic composition which concerns on the engine unit shown in FIG. It is a flowchart explaining operation | movement of the engine unit shown in FIG. It is a chart explaining the movement of the crankshaft from the engine combustion stop to the engine restart in the engine unit EU of the first embodiment. It is a flowchart explaining operation | movement of the engine unit which concerns on 2nd embodiment of this invention. (A) is a chart explaining the movement of the crankshaft from engine combustion stop to engine restart in the engine unit EU of the second embodiment, and (b) is the engine combustion in the engine unit EU of the third embodiment. It is a chart explaining the movement of the crankshaft from the stop to the engine restart. It is an external view which shows the vehicle by which an engine unit is mounted. It is a fragmentary sectional view showing typically a schematic structure of a water cooling type engine unit concerning the present invention.

[Engine unit]
FIG. 1 is a partial cross-sectional view schematically showing a schematic configuration of an air-cooled engine unit EU according to the first embodiment of the present invention. The engine unit EU in the present embodiment is a vehicle four-stroke engine unit.

  The engine unit EU is provided in a motorcycle (see FIG. 10) that is an example of a vehicle. The engine unit EU includes a 4-stroke engine body E and a rotating electrical machine SG. The 4-stroke engine body E is a single-cylinder 4-stroke engine. The 4-stroke engine body E has a relationship between the crank angle position and the required torque shown in FIG.

  FIG. 2 is an explanatory view schematically showing the relationship between the crank angle position and the required torque when the engine is started.

  The four-stroke engine body E has a high load region where the load for rotating the crankshaft 5 is large and the low load region where the load for rotating the crankshaft 5 is smaller than the load in the high load region during the four strokes. Looking at the rotation angle of the crankshaft 5 as a reference, the low load region is wider than the high load region. The rotation angle region corresponding to the low load region is wider than the rotation angle region corresponding to the high load region. More specifically, the four-stroke engine body E rotates while repeating four steps of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. As shown in FIG. 2, the compression stroke is included in the high load region and is not included in the low load region. In the four-stroke engine main body E of the present embodiment, the high load region is a region that substantially overlaps the compression stroke, and the low load region is a region that substantially overlaps the intake stroke, the expansion stroke, and the exhaust stroke. However, the boundaries between the high load region and the low load region do not need to coincide with the boundaries of the above-described processes.

  As shown in FIG. 1, the engine unit EU includes a rotating electrical machine SG. The rotating electrical machine SG is a three-phase brushless rotating electrical machine. The rotating electrical machine SG rotates the crankshaft 5 to start the four-stroke engine body E when the engine is started. The rotating electrical machine SG functions as a generator by being rotated by the crankshaft 5 at least after the start of the 4-stroke engine body E. In the case where the rotating electrical machine SG functions as a generator, the rotating electrical machine SG does not always need to function as a generator after the start of combustion of the engine. For example, after the combustion of the engine starts, the rotating electrical machine SG may not function as a generator immediately, and the rotating electrical machine SG may function as a generator when a predetermined condition is satisfied. Examples of such predetermined conditions include that the engine rotation speed has reached a predetermined speed, and that a predetermined time has elapsed since the start of engine combustion. Further, after the start of combustion of the engine, a period in which the rotating electrical machine SG functions as a generator and a period in which the rotating electrical machine SG functions as a motor (for example, a vehicle driving motor) may be included.

  The rotating electrical machine SG is attached to the crankshaft 5 of the 4-stroke engine body E. In this embodiment, the rotating electrical machine SG is attached to the crankshaft 5 without a power transmission mechanism (for example, a belt, a chain, a gear, a speed reducer, a speed increaser, or the like). However, in the present invention, the rotating electrical machine SG may be configured to rotate the crankshaft 5 by the rotation of the rotating electrical machine SG. Therefore, the rotating electrical machine SG may be attached to the crankshaft 5 via a power transmission mechanism. In the present invention, it is preferable that the rotation axis of the rotating electrical machine SG and the rotation axis of the crankshaft 5 substantially coincide. Moreover, it is preferable that the rotary electric machine SG is attached to the crankshaft 5 not via a power transmission mechanism like this embodiment.

  The 4-stroke engine body E includes a crankcase 1 (engine case 1), a cylinder 2, a piston 3, a connecting rod 4, and a crankshaft 5. The cylinder 2 is provided in a manner protruding from the crankcase 1 in a predetermined direction (for example, obliquely upward). The piston 3 is provided in the cylinder 2 so as to be reciprocally movable. The crankshaft 5 is rotatably provided in the crankcase 1. One end (for example, the upper end) of the connecting rod 4 is connected to the piston 3. The other end (for example, the lower end) of the connecting rod 4 is connected to the crankshaft 5. A cylinder head 6 is attached to an end portion (for example, an upper end portion) of the cylinder 2. The crankshaft 5 is supported on the crankcase 1 through a pair of bearings 7 in a rotatable manner. One end portion 5 a (for example, right end portion) of the crankshaft 5 protrudes outward from the crankcase 1. A rotating electrical machine SG is attached to one end portion 5 a of the crankshaft 5.

  The other end portion 5 b (for example, the left end portion) of the crankshaft 5 protrudes outward from the crankcase 1. A primary pulley 20 of a continuously variable transmission CVT is attached to the other end portion 5 b of the crankshaft 5. The primary pulley 20 has a fixed sheave 21 and a movable sheave 22. The fixed sheave 21 is fixed to the distal end portion of the other end portion 5 b of the crankshaft 5 so as to rotate together with the crankshaft 5. The movable sheave 22 is splined to the other end 5 b of the crankshaft 5. Therefore, the movable sheave 22 is movable along the axial direction X, and rotates with the crankshaft 5 in such a manner that the distance from the fixed sheave 21 is changed. A belt B is hung on the primary pulley 20 and a secondary pulley (not shown). The rotational force of the crankshaft 5 is transmitted to the drive wheels of the motorcycle (see FIG. 8). The 4-stroke engine body E of the present embodiment is an air-cooled engine.

  FIG. 3 is an enlarged cross-sectional view showing the rotating electrical machine SG in FIG. 1 and its vicinity in an enlarged manner. 4 is a cross-sectional view showing a cross section perpendicular to the rotation axis J of the rotating electrical machine SG shown in FIG.

  The rotating electrical machine SG includes an outer rotor 30, an inner stator 40, and a magnetic sensor unit (not shown). The outer rotor 30 has an outer rotor main body 31. The outer rotor main body 31 is made of, for example, a ferromagnetic material. The outer rotor main body 31 has a bottomed cylindrical shape. The outer rotor main body 31 includes a cylindrical boss portion 32, a disk-shaped bottom wall portion 33, and a cylindrical back yoke portion 34. The cylindrical boss portion 32 is fixed to the crankshaft 5 while being inserted into the one end portion 5 a of the crankshaft 5. The bottom wall portion 33 is fixed to the cylindrical boss portion 32 and has a disk shape that extends in the radial direction Y of the crankshaft 5. The back yoke portion 34 has a cylindrical shape extending from the outer peripheral edge of the bottom wall portion 33 in the axial direction X of the crankshaft 5. The back yoke portion 34 extends in a direction approaching the crankcase 1.

  The bottom wall portion 33 and the back yoke portion 34 are integrally formed, for example, by press molding a metal plate. In the present invention, the bottom wall portion 33 and the back yoke portion 34 may be configured separately. That is, in the outer rotor main body 31, the back yoke portion 34 may be formed integrally with other parts constituting the outer rotor main body 31, and is separate from other parts constituting the outer rotor main body 31. It may be configured on the body. In the case where the back yoke portion 34 and other portions are configured separately, the back yoke portion 34 may be made of a ferromagnetic material, and the other portion may be made of a material other than the ferromagnetic material. .

  A tapered insertion hole 32 a for inserting one end portion 5 a of the crankshaft 5 is formed in the cylindrical boss portion 32 along the axial direction X of the crankshaft 5. The tapered insertion hole 32 a has a taper angle corresponding to the outer peripheral surface of the one end portion 5 a of the crankshaft 5. When the one end portion 5a of the crankshaft 5 is inserted into the insertion hole 32a, the outer peripheral surface of the one end portion 5a contacts the inner peripheral surface of the insertion hole 32a, and the crankshaft 5 is fixed to the insertion hole 32a. Thereby, the boss part 32 is positioned with respect to the axial direction X of the crankshaft 5. In this state, the nut 35 is screwed into the male screw portion 5 c formed at the tip portion of the one end portion 5 a of the crankshaft 5. Thereby, the cylindrical boss part 32 is fixed to the crankshaft 5.

  The cylindrical boss portion 32 has a large-diameter portion 32 b at the base end portion of the cylindrical boss portion 32 (the right portion of the cylindrical boss portion 32 in the drawing). The cylindrical boss portion 32 has a flange portion 32c extending outward in the radial direction on the outer peripheral surface of the large diameter portion 32b. A large-diameter portion 32b of the cylindrical boss portion 32 is inserted into a hole portion 33a formed in the center portion of the bottom wall portion 33 of the outer rotor main body portion 31. In this state, the flange portion 32c is in contact with the outer peripheral surface (right side surface in the figure) of the bottom wall portion 33. A rivet 36 in which the flange portion 32 c of the cylindrical boss portion 32 and the bottom wall portion 33 of the outer rotor main body portion 31 penetrate the flange portion 32 c and the bottom wall portion 33 at a plurality of locations in the circumferential direction of the outer rotor main body portion 31. It is fixed integrally with.

  The back yoke portion 34 of the outer rotor main body 31 is provided with a plurality of permanent magnet portions 37 on the inner peripheral surface of the back yoke portion 34. Each permanent magnet portion 37 is provided such that the S pole and the N pole are aligned in the radial direction of the rotating electrical machine SG.

  The plurality of permanent magnet portions 37 are provided so that N poles and S poles are alternately arranged in the circumferential direction of the rotating electrical machine SG. In the present embodiment, the number of magnetic poles of the outer rotor 30 facing the inner stator 40 is 24. The number of magnetic poles of the outer rotor 30 refers to the number of magnetic poles facing the inner stator 40. The number of magnetic pole surfaces of the permanent magnet portion 37 facing the tooth portion 43 of the stator core ST corresponds to the number of magnetic poles of the outer rotor 30. The magnetic pole surface per magnetic pole included in the outer rotor 30 corresponds to the magnetic pole surface of the permanent magnet portion 37 facing the inner stator 40. The magnetic pole surface of the permanent magnet part 37 is covered with a nonmagnetic material (not shown) provided between the permanent magnet part 37 and the inner stator 40. No magnetic material is provided between the permanent magnet portion 37 and the inner stator 40. It does not specifically limit as a nonmagnetic material, For example, a stainless steel material is mentioned. In the present embodiment, the permanent magnet portion 37 is a ferrite magnet. However, in the present invention, conventionally known magnets such as neodymium bond magnets, samarium cobalt magnets and neodymium magnets can be employed as the permanent magnets. The shape of the permanent magnet part 37 is not particularly limited. The outer rotor 30 may be an embedded magnet type (IPM type) in which the permanent magnet part 37 is embedded in a magnetic material, but the permanent magnet part 37 is exposed from the magnetic material as in the present embodiment. A surface magnet type (SPM type) is preferred.

  As described above, the outer rotor 30 attached to the crankshaft 5 and attached to rotate together with the crankshaft 5 is a rotating body for increasing the inertia of the crankshaft 5. A cooling fan F having a plurality of blade portions Fa is provided on the outer peripheral surface (the right side surface in FIGS. 1 and 3) of the bottom wall portion 33 constituting the outer rotor 30. The cooling fan F is fixed to the outer peripheral surface of the bottom wall portion 33 with a fixture (a plurality of bolts Fb).

  The inner stator 40 includes a stator core ST and a plurality of stator windings W. Stator core ST is formed, for example, by laminating thin silicon steel plates along the axial direction. The stator core ST has a hole 41 having an inner diameter larger than the outer diameter of the cylindrical boss portion 32 of the outer rotor 30 at the center of the stator core ST. Further, the stator core ST has a plurality of tooth portions 43 that integrally extend outward in the radial direction (see FIG. 4). In the present embodiment, a total of 18 tooth portions 43 are provided at intervals in the circumferential direction. In other words, the stator core ST has a total of 18 slots SL (see FIG. 4) formed at intervals in the circumferential direction.

  A stator winding W is wound around each tooth portion 43. The multi-phase stator winding W is provided so as to pass through the slot SL. Each of the multi-phase stator windings W belongs to one of the U phase, the V phase, and the W phase. For example, the stator windings W are arranged in the order of the U phase, the V phase, and the W phase.

  As shown in FIG. 3, the inner stator 40 is formed with a hole 41 in the central portion in the radial direction of the rotating electrical machine SG. In the hole portion 41, the crankshaft 5 and the cylindrical boss portion 32 of the outer rotor 30 are disposed at a distance from the wall surface (inner stator 40) of the hole portion 41. In this state, the inner stator 40 is attached to the crankcase 1 of the four-stroke engine main body E. The end portion (tip surface) of the tooth portion 43 of the inner stator 40 is disposed at a distance from the magnetic pole surface (inner peripheral surface) of the permanent magnet portion 37 constituting the outer rotor 30. In this state, the outer rotor 30 rotates in conjunction with the rotation of the crankshaft 5. The outer rotor 30 rotates integrally with the crankshaft 5.

  The outer rotor 30 will be further described with reference to FIG. The permanent magnet portion 37 is provided outside the inner stator 40 in the radial direction of the rotating electrical machine SG. The back yoke portion 34 is provided outside the permanent magnet portion 37 in the radial direction. The permanent magnet portion 37 includes a plurality of magnetic pole surfaces 37 a in the circumferential direction on the surface facing the inner stator 40. The magnetic pole surface 37a is arranged in the circumferential direction of the rotating electrical machine SG. Each of the magnetic pole surfaces 37a is an N pole or an S pole. The N pole and the S pole are alternately arranged in the circumferential direction of the rotating electrical machine SG. The magnetic pole surface 37 a of the permanent magnet portion 37 faces the inner stator 40. In the present embodiment, a plurality of magnets are disposed in the radial direction of the rotating electrical machine SG, and each of the plurality of magnets is disposed in a posture in which the S pole and the N pole are directed in the radial direction of the rotating electrical machine SG. . One S pole and one N pole adjacent in the circumferential direction constitute a magnetic pole pair. The number of magnetic pole pairs is ½ of the number of magnetic pole surfaces 37a. In the present embodiment, 24 magnetic pole surfaces 37a facing the inner stator 40 are provided on the outer rotor 30, and the number of magnetic pole pairs of the outer rotor 30 is twelve. In the figure, twelve magnetic pole pairs 37p are shown. However, for easy viewing of the figure, the reference numeral 37p indicates only one pair.

  A plurality of detected portions 38 for detecting the rotational position of the outer rotor 30 are provided on the outer surface of the outer rotor 30. The plurality of detected parts 38 are detected by a magnetic action. The plurality of detected portions 38 are provided on the outer surface of the outer rotor 30 at intervals in the circumferential direction. In the present embodiment, the plurality of detected portions 38 are provided on the outer peripheral surface of the outer rotor 30 at intervals in the circumferential direction. The plurality of detected portions 38 are disposed on the outer peripheral surface of the cylindrical back yoke portion 34. Each of the plurality of detected portions 38 protrudes outward in the radial direction Y of the rotating electrical machine SG from the outer peripheral surface of the back yoke portion 34. The bottom wall portion 33, the back yoke portion 34, and the detected portion 38 are integrally formed, for example, by press-molding a metal plate such as iron. That is, the detected part 38 is made of a ferromagnetic material. Details of the arrangement of the detected parts 38 will be described later.

  The rotor position detection device 50 is a device that detects the position of the outer rotor 30. The rotor position detection device 50 is provided at a position facing the plurality of detected parts 38. That is, the rotor position detection device 50 is disposed at a position where the plurality of detected portions 38 sequentially face the rotor position detection device 50. The rotor position detection device 50 faces a path through which the detected portion 38 passes as the outer rotor 30 rotates. The rotor position detection device 50 is disposed at a position away from the inner stator 40. In the present embodiment, the rotor position detection device 50 includes the back yoke portion 34 and the permanent magnet portion 37 of the outer rotor 30 between the rotor position detection device 50 and the inner stator 40 and the stator winding W in the radial direction of the crankshaft 5. Is arranged to be located. The rotor position detection device 50 is disposed outside the outer rotor 30 in the radial direction of the rotating electrical machine SG, and faces the outer peripheral surface of the outer rotor 30.

  The rotor position detection device 50 includes a detection winding 51, a detection magnet 52, and a core 53. The detection winding 51 functions as a pickup coil that detects the detected portion 38. The core 53 is a member extending in the shape of, for example, an iron bar. The detection winding 51 magnetically detects the detected portion 38. The rotor position detection device 50 starts detecting the rotational position of the outer rotor 30 after the crankshaft 5 starts rotating. The rotor position detecting device 50 may employ a configuration other than the type in which the voltage generated by the electromotive force associated with the passage of the detected portion 38 changes. For example, the rotor position detection device 50 may employ a configuration in which the detection winding 51 is always energized and the energization current changes due to the change in inductance accompanying the passage of the detected portion 38. The rotor position detection device 50 is not particularly limited, and may include a Hall element or an MR element. The engine unit EU (see FIG. 1) of the present embodiment may include a Hall element or an MR element.

  Here, with reference to FIG. 4, the arrangement of the detected portions 38 in the outer rotor 30 will be described. The plurality of detected portions 38 in the present embodiment are provided on the outer surface of the outer rotor 30 and are provided at positions where the relative positions of the magnetic pole surface with respect to the pair 37p are the same. The rotor position detection device 50 is provided at a position facing the plurality of detected portions 38. In FIG. 4, a predetermined position in the circumferential direction in the magnetic pole pair 37p formed by two magnetic poles (S pole and N pole) adjacent in the circumferential direction is indicated by a one-dot chain line. In the present embodiment, the eleven detected portions 38 that are one less than the number of specified positions are provided in the outer rotor 30. The eleven detected parts 38 are respectively provided at eleven of the twelve prescribed positions.

FIG. 5 is a block diagram showing an electrical basic configuration of the engine unit EU shown in FIG.
The engine unit EU includes a 4-stroke engine body E, a rotating electrical machine SG, and a control device CT. A rotating electrical machine SG, a spark plug 29, and a battery 14 are connected to the control device CT.

  Control device CT is connected to a plurality of stator windings W, and supplies a current from battery 14 provided in the vehicle to the plurality of stator windings W. The control device CT includes a rotating electrical machine control unit 62, a combustion control unit 63, and a plurality of switching units 611 to 616. Control device CT in this embodiment has six switching parts 611-616. The switching units 611 to 616 constitute a three-phase bridge inverter. The plurality of switching units 611 to 616 are connected to the respective phases of the plurality of phases of the stator winding W, and switch the passage / interruption of current between the plurality of phases of the stator winding W and the battery 14. More specifically, when the rotating electrical machine SG functions as a starter motor, energization and deenergization of each of the plurality of phases of the stator winding W are switched by the on / off operations of the switching units 611 to 616. Further, when the rotating electrical machine SG functions as a generator, the current passing between each of the stator windings W and the battery 14 is switched by the on / off operation of the switching units 611 to 616. By sequentially switching on and off the switching units 611 to 616, rectification and voltage control of the three-phase AC output from the rotating electrical machine SG is performed. In the present specification, the operation in which the control device CT supplies the current of the battery 14 to the stator winding W when the switching units 611 to 616 are turned on is referred to as “energization”. A distinction is made from the operation of passing current between the stator winding W of the plurality of phases and the battery 14 by the ON operation.

  Each of the switching units 611 to 616 includes a switching element. The switching element is, for example, a transistor, and more specifically, an FET (Field Effect Transistor). However, in addition to the FET, for example, a thyristor and an IGBT (Insulated Gate Bipolar Transistor) can also be used for the switching units 611 to 616.

  The rotating electrical machine control unit 62 controls the operation of the rotating electrical machine SG by controlling each on / off operation of the switching units 611 to 616. The rotating electrical machine control unit 62 includes a stop control unit 621, a positioning unit 622, and a restart control unit 623. The rotating electrical machine control unit 62 and the combustion control unit 63 are realized by computer hardware (not shown) and control software executed by the computer hardware. However, part or all of the rotating electrical machine control unit 62 and the combustion control unit 63 can be realized by a hardware circuit that is an electronic circuit. Moreover, the rotary electric machine control part 62 and the combustion control part 63 may be comprised in the position which mutually separated as a mutually different apparatus, for example, and may be comprised integrally.

The stop control unit 621 performs processing for stopping the rotation of the crankshaft 5 by controlling the rotation of the crankshaft 5 by performing vector control on the rotating electrical machine SG after the combustion of the engine is stopped. The positioning unit 622 positions the crankshaft 5 by rotating the crankshaft 5 after the combustion of the engine and the rotation of the crankshaft 5 stop.
When the restarting control unit 623 receives a restart command, the restarting control unit 623 performs processing for starting rotation of the crankshaft 5 by controlling the rotating electrical machine SG.

  The combustion control unit 63 controls the combustion operation of the four-stroke engine body E by causing the ignition plug 29 to perform an ignition operation. When the four-stroke engine main body E includes a fuel injection device that injects fuel into a passage that guides air to the combustion chamber of the cylinder 2 (see FIG. 1) to generate an air-fuel mixture, the combustion control unit 63 The combustion operation of the four-stroke engine body E is controlled by controlling the injection of the apparatus.

  A starter switch 16 for starting the 4-stroke engine main body E is connected to the rotating electrical machine control unit 62. The starter switch 16 is operated by the driver when the four-stroke engine body E is started. Further, the rotating electrical machine control unit 62 of the control device CT detects the state of charge of the battery 14 by detecting the voltage of the battery 14. However, the detection of the state of charge of the battery 14 can employ, for example, a configuration for detecting the current flowing through the battery 14 in the state of charge, in addition to the configuration for detecting the voltage of the battery 14.

  The control device CT controls the inverter 61 by the rotating electrical machine control unit 62. The control device CT controls the rotating electrical machine SG through the operation of the inverter 61. In the present embodiment, a capacitor (not shown) is provided between the inverter 61 and the battery 14, and the battery 14 and the capacitor constitute a power storage unit.

FIG. 6 is a flowchart for explaining the operation of the engine unit EU shown in FIG.
The stop operation of the engine unit EU described here is started from the combustion operation state of the engine unit EU (step S11).

  The combustion operation state is, for example, an idling state. The idling state refers to a state where the vehicle is stopped and the engine is rotating. In the idling state, the engine is in a no-load state and is operating at a minimum rotational speed. Note that the description of the operation when the acceleration command is input in the idling state and the idling state is ended and the vehicle starts to travel will be omitted. Hereinafter, the combustion state will be described using an example of an idling state.

  In a vehicle in which the engine stops while the vehicle is stopped, it is determined that the vehicle has stopped after a predetermined time has elapsed since the vehicle stopped, and the engine stops. In this case, during the period from when the vehicle stops to when it is determined that the vehicle has stopped, the vehicle is in a state where the vehicle is stopped and the engine is stopped, that is, in an idling state.

  Further, among vehicles in which the engine stops while the vehicle is stopped, there is a vehicle configured to charge the battery by operating the engine when the remaining amount of the battery decreases while the vehicle is stopped. The operation of the engine here can be said to be an operation for power generation. However, during the operation of the engine here, the vehicle is stopped and the engine is rotating, that is, the idling state. Thus, the idling state may be started for power generation when the vehicle is stopped.

  When the engine unit EU is in the idling state, that is, the combustion operation state (step S11), if the combustion stop command is not input (step S12: NO), the combustion operation state is continued. For example, when the engine unit EU is in the idling state (step S11), if the combustion stop command is not input (step S12: NO), the idling state is continued. On the other hand, if a combustion stop command is input (step S12: YES), combustion of the engine is stopped (step S13). The combustion stop command may be an internal command generated when the control device CT determines that the vehicle has stopped. Further, the combustion stop command may be an external command input by the driver. Even if the combustion of the engine is stopped, the crankshaft 5 continues to rotate temporarily due to inertia. The rotation of the crankshaft 5 is detected by the rotor position detection device 50. Note that the rotor position detection device 50 according to the present embodiment detects a change in electromotive force associated with the passage of the detected portion 38. Therefore, the rotor position detection device 50 of the present embodiment cannot detect the rotation of the crankshaft 5 when the rotation of the crankshaft 5 becomes slow and the change in electromotive force becomes small. However, it can be said that the crankshaft 5 is rotating at least when the rotation of the crankshaft 5 is detected by the rotor position detection device 50. The rotor position detection device 50 is not limited to the example of the present embodiment, and may be configured to detect the rotation of the crankshaft 5 until the rotation of the crankshaft 5 stops, for example.

  After stopping the combustion of the engine (after step S13), the control device CT controls the rotation of the crankshaft 5 by performing vector control to stop the rotation of the crankshaft 5 (step S14). The control device CT performs vector control on the rotating electrical machine according to the rotational speed of the crankshaft 5 and the position of the crankshaft. The control device CT performs control for accelerating the rotation of the crankshaft or control for imparting resistance to the rotation of the crankshaft while performing feedback according to the rotational speed of the crankshaft 5 and the position of the crankshaft 5.

  The vector control is control for turning on / off the plurality of switching units 611 to 616 by a PWM modulated signal. In vector control, the duty ratio changes dynamically within an electrical angle of 180 °. As a result, a sinusoidal current flows through the stator winding W. Here, the sine wave current includes a current having a ripple current associated with ON / OFF of the plurality of switching units 611 to 616.

  The application of resistance to rotation of the crankshaft by vector control is realized, for example, by flowing a current along the direction of the sine wave so as to synchronize with the sine wave of the induced voltage of the stator winding W. In other words, the application of resistance to rotation of the crankshaft by vector control is realized, for example, by forcibly extracting the induced current in the direction of the current due to the induced voltage.

  The acceleration of the rotation of the crankshaft 5 by the vector control is realized, for example, by flowing a current in the direction opposite to the direction of the sine wave so as to synchronize with the sine wave of the induced voltage of the stator winding W. In other words, acceleration of rotation of the crankshaft 5 by vector control is realized by, for example, passing a current from the battery 14 to the stator winding W so as to overcome the induced voltage of the stator winding W.

  Control of rotation of the crankshaft by vector control can be performed by controlling the phase and amplitude of the current flowing through the stator winding W. According to the vector control, the degree of acceleration or resistance can be precisely controlled according to the rotational speed of the crankshaft 5 and the position of the crankshaft.

  Further, when the switching elements 611 to 616 are turned on / off by PWM control, the switching elements 611 to 616 and the plurality of phases of the stator winding W function as a chopper circuit. As a result, the current flowing from the stator winding W through the switching elements 611 to 616 toward the battery 14 is boosted. Therefore, even when the idling speed is low (for example, about 1000 rpm), it is possible to draw current from the stator windings W having a plurality of phases. As a result, a strong braking force can be obtained. Even if the induced voltage of the stator winding W is lower than the voltage of the battery 14, the battery 14 can be charged by the action of the chopper circuit. In a state where the rotation speed is closer to the rotation speed when the engine is stopped than the rotation speed when idling, the power of the battery 14 is consumed. However, the resistance to rotation of the crankshaft 5 by vector control is still applied to the crankshaft. A strong braking force is generated for 5 rotations.

  The control device CT controls the rotation of the crankshaft 5 according to the rotational speed of the crankshaft 5 and the position of the crankshaft 5. The control device CT controls the degree of acceleration or resistance according to the position of the crankshaft 5. For example, the control device CT performs control to give higher resistance to the rotation of the crankshaft as the rotation speed of the crankshaft 5 is higher. Further, for example, the control device CT performs control to give higher resistance to the rotation of the crankshaft as the position of the crankshaft 5 is closer to the target stop position.

  The control device CT detects the position and rotation speed of the crankshaft 5 based on a signal from the rotor position detection device 50. However, the control device CT may detect the position and rotation speed of the crankshaft 5 based on signals from devices or sensors other than the rotor position detection device 50 such as the combustion control unit 63, for example.

  The control device CT periodically reflects the position and rotational speed of the crankshaft 5 in the control of the rotation of the crankshaft 5. The frequency at which the control device CT reflects the position and rotational speed of the crankshaft 5 in the control of the rotation of the crankshaft 5 is one or more times. For example, a control method in which the control device CT controls the rotation of the crankshaft 5 in accordance with the rotational speed of the crankshaft 5 and the position of the crankshaft 5 can be employed. However, the control device CT may continuously reflect the position and rotational speed of the crankshaft 5 in the control of the rotation of the crankshaft 5.

  The control device CT stops the crankshaft at or near the target position by controlling the rotation of the crankshaft 5 to stop the rotation of the crankshaft 5. The target position is a position set in advance as a position suitable for shortening the time taken until the 4-stroke engine body E restarts. The target position will be described later.

  After the crankshaft 5 is stopped (step S15: YES), when a restart command is input (step S16: YES), the control device CT rotates the crankshaft 5 (step S18). Thereafter, the control device CT restarts the engine (step S18).

FIG. 7 is a chart for explaining the movement of the crankshaft from the engine combustion stop to the engine restart in the engine unit EU of the present embodiment.
FIG. 7 shows a target position P1 as a target position set in the four-stroke engine body in the present embodiment. The target position P1 is a position suitable for shortening the time required for restarting the crankshaft 5 from the stopped state in the four-stroke engine body E. The target position P1 is set in the compression stroke of the 4-stroke engine body E.

  In the engine unit EU of the present embodiment, after the combustion of the four-stroke engine main body E is stopped, the control device CT performs vector control on the rotating electrical machine SG according to the rotational speed and position of the crankshaft 5. The control device CT controls the rotation of the crankshaft 5 to stop the rotation of the crankshaft 5 at or near the target position P1.

  When the restart command is input, the control device CT rotates the crankshaft 5 from the target position P1. Thereafter, the control device CT restarts the engine.

  In the engine unit EU of the present embodiment, for example, after the combustion of the 4-stroke engine main body is stopped, the rotation of the crankshaft is not controlled and the crankshaft 5 is stopped at a position other than the target position P1 or the vicinity of the target position P1. Thus, the time taken to restart is shortened.

  Thus, according to the present embodiment, the time from the engine combustion stop to the engine restart can be shortened without requiring an increase in the size of the rotating electrical machine.

  Next, a second embodiment of the present invention will be described. In the following description of the second embodiment, elements corresponding to those in the first embodiment are denoted by the same reference numerals, and differences from the first embodiment described above will be mainly described.

  FIG. 8 is a flowchart for explaining the operation of the engine unit EU according to the second embodiment of the present invention.

  After the combustion of the 4-stroke engine main body E stops (after step S13), the control device CT in the present embodiment controls the rotation of the crankshaft 5 by vector control (step S214). Stop at a target position suitable for starting the reverse rotation. Further, the control device CT is after the combustion of the 4-stroke engine main body E and the rotation of the crankshaft 5 are stopped (step S15: YES), and before the restart command is input (before step S17). ), The crankshaft 5 is positioned (step S216). The controller CT reversely rotates the crankshaft 5 when positioning the crankshaft 5. That is, in positioning the crankshaft 5, the crankshaft 5 rotates in the opposite direction to the normal rotation during engine combustion.

  FIG. 9A is a chart for explaining the movement of the crankshaft from the engine combustion stop to the engine restart in the engine unit EU of the second embodiment. A target position P1 shown in FIG. 9A is a position suitable for starting the positioning of the crankshaft 5 in the four-stroke engine body E of the present embodiment.

  In the engine unit EU of the present embodiment, after the combustion of the four-stroke engine main body E is stopped, the control device CT performs vector control on the rotating electrical machine SG according to the rotational speed and position of the crankshaft 5. The control device CT controls the rotation of the crankshaft 5 to stop the rotation of the crankshaft 5 at or near the target position P1.

  Thereafter, the control device CT rotates the crankshaft 5 backward from the target position P1 or the vicinity of the target position P1 to another position P2. When a restart command is input, the control device CT rotates the crankshaft 5 forward from the position P2.

  When the crankshaft 5 rotates in the reverse direction to the position P2 and starts rotating in response to the input of the restart instruction, the crankshaft 5 rotates in the normal direction over almost the entire low load region from the expansion stroke to the compression stroke, and then compressed. The high load area in the process is reached. Therefore, the rotational speed of the crankshaft 5 can be increased before reaching the high load region. And the high load area | region of a compression stroke can be overcome using both the big inertia force accompanying high rotational speed, and the output torque of the rotary electric machine SG. The target position P1 is a position suitable for the control device CT to start reverse rotation of the crankshaft 5 to the position P2.

  In the engine unit EU of the present embodiment, for example, after the combustion of the 4-stroke engine main body is stopped, the rotation of the crankshaft is not controlled, and the crankshaft 5 is at a position other than the target position P1 or the vicinity of the target position P1 (for example, P1 ′). Compared with the case of stopping at, the time taken to restart is shortened.

Subsequently, a third embodiment of the present invention will be described.
The control device CT in the third embodiment is different from the control device CT in the third embodiment in that the crankshaft 5 is rotated forward and the crankshaft 5 is stopped in positioning the crankshaft 5.

  FIG. 9B is a chart for explaining the movement of the crankshaft from the engine combustion stop to the engine restart in the engine unit EU of the third embodiment. The target position P1 is a position suitable for starting the positioning of the crankshaft 5 in the four-stroke engine body E of the present embodiment.

  In the engine unit EU of the present embodiment, after the combustion of the four-stroke engine main body E is stopped, the control device CT performs vector control on the rotating electrical machine SG according to the rotational speed and position of the crankshaft 5. The control device CT controls the rotation of the crankshaft 5 to stop the rotation of the crankshaft 5 at or near the target position P1.

  Thereafter, the control device CT rotates the crankshaft 5 forward from the target position P1 or the vicinity of the target position P1 to another position P2. When a restart command is input, the control device CT rotates the crankshaft 5 forward from the position P2.

  When the crankshaft 5 starts to rotate in response to the input of the restart instruction by rotating forward to the position P2, the crankshaft 5 can get over the high load region of the compression stroke at a low speed. Thereafter, the crankshaft 5 normally rotates over almost the entire low load region from the expansion stroke to the next compression stroke, and then reaches the second high load region in the compression stroke. Therefore, the rotational speed of the crankshaft 5 can be increased before reaching the high load region. And the high load area | region of a compression stroke can be overcome using both the big inertia force accompanying high rotational speed, and the output torque of the rotary electric machine SG. The target position P1 is a position suitable for the control device CT to start normal rotation to the position P2 of the crankshaft 5.

  In the engine unit EU of the present embodiment, for example, after the combustion of the 4-stroke engine main body is stopped, the rotation of the crankshaft is not controlled, and the crankshaft 5 is at a position other than the target position P1 or the vicinity of the target position P1 (for example, P1 ′). Compared with the case of stopping at, the time taken to restart is shortened.

[Motorcycle]
FIG. 10 is an external view showing a vehicle on which the engine unit EU according to the first to third embodiments is mounted.
A vehicle A shown in FIG. 10 includes an engine unit EU, a vehicle body 101, wheels 102 and 103, and a battery 14. The engine unit EU mounted on the vehicle A drives the wheel 103 that is a driving wheel, and rotates the wheel 103 to cause the vehicle A to travel.

  The vehicle A shown in FIG. 10 has heat resistance while ensuring early startability, and is equipped with an engine unit having a simple structure and high vehicle mountability, so that the entire vehicle A can be made compact.

  A vehicle A shown in FIG. 10 is a motorcycle. However, the vehicle of the present invention is not limited to a motorcycle. Examples of the vehicle of the present invention include scooter type, moped type, off-road type, and on-road type motorcycles. The straddle-type vehicle is not limited to a motorcycle, and may be an ATV (All-Train Vehicle) or the like, for example. Further, the vehicle according to the present invention is not limited to a saddle-ride type vehicle, and may be a four-wheel vehicle having a passenger compartment.

  In the present embodiment, a three-phase brushless rotating electrical machine is shown as an example of a starter motor. However, the configuration of the stator winding of the starter motor of the present invention is not limited to a three-phase configuration, and may be, for example, a two-phase configuration or a configuration of four or more phases.

  In the present embodiment, the air-cooled four-stroke engine main body E has been described as an example of the four-stroke engine main body E. However, the 4-stroke engine body E is not limited to the air-cooled type.

  FIG. 11 is a partial cross-sectional view schematically showing a schematic configuration of a water-cooled engine unit EU. The present invention is also applicable to an engine unit EU provided with a water-cooled four-stroke engine main body E shown in FIG.

  In the present embodiment, the case where the four-stroke engine body E is a single cylinder engine has been described. However, the engine unit of the present invention is not particularly limited as long as it is an engine unit having a high load region and a low load region. That is, a multi-cylinder engine may be used. Examples other than the present embodiment include engines such as an in-line single cylinder, a parallel two-cylinder, an in-line two-cylinder, a V-type two-cylinder, and a horizontally opposed two-cylinder. The number of cylinders of the multi-cylinder engine is not particularly limited, and the multi-cylinder engine may be, for example, a four-cylinder engine. However, the four-cylinder engine includes an engine unit that does not have a low load region, such as a four-cylinder engine in which the compression stroke of each cylinder is generated at equal intervals (four-cylinder engine that performs explosion at equal intervals). Thus, the engine unit which does not have a low load area | region does not correspond to the engine unit of this invention.

  The terms and expressions used herein are used for explanation and are not used for limited interpretation. It should be recognized that any equivalents of the features shown and described herein are not excluded and that various modifications within the claimed scope of the invention are permitted.

  The present invention can be embodied in many different forms. This disclosure should be considered as providing an example of the principles of the invention. Many illustrated embodiments are described herein with the understanding that these examples are not intended to limit the invention to the preferred embodiments described and / or illustrated herein.

  Several illustrative embodiments of the invention have been described herein. The present invention is not limited to the various preferred embodiments described herein. The present invention includes all embodiments including equivalent elements, modifications, deletions, combinations (eg, combinations of features across the various embodiments), improvements, and / or changes that can be recognized by those skilled in the art based on this disclosure. Include. Claim limitations should be construed broadly based on the terms used in the claims and should not be limited to the embodiments described herein or in the process of this application. Such embodiments should be construed as non-exclusive. For example, in this disclosure, the term “preferably” is non-exclusive and means “preferably but not limited to”.

A vehicle CT control device E 4-stroke engine main body EU engine unit SG rotating electrical machine 5 crankshaft 50 rotor position detection device 61 inverters 611 to 616 switching unit

Claims (1)

An engine unit mounted on a vehicle,
The engine unit is
It has a high load region and a low load region during four strokes in a combustion stop state, and the load for rotating the crankshaft in the high load region is larger than the load for rotating the crankshaft in the low load region A 4-stroke engine body,
A rotating electrical machine configured to receive power from a battery included in the vehicle to rotate the crankshaft, and to be able to charge the battery by power generation accompanying rotation of the crankshaft;
An inverter for controlling a current flowing between the battery and the rotating electrical machine;
A control device for controlling the rotating electrical machine and the 4-stroke engine main body,
The control device controls the rotation of the crankshaft by performing vector control on the rotating electrical machine according to the rotational speed of the crankshaft and the position of the crankshaft after the combustion of the four-stroke engine main body is stopped. To stop the rotation of the crankshaft.

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