JP2008160995A - Generator, and vehicle equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a generator capable of stabilizing a power generation amount while suppressing excessive power generation, and to provide a vehicle equipped with the generator. <P>SOLUTION: The generator 30 includes a rotor 31, a permanent magnet 31a, a first guide member 32, a weight 32c, a slider 33 and a stator core 38. The rotor 31 is connected to a crankshaft 251 and rotates according to the rotation of the crankshaft 251. When the rotational speed of the crankshaft 251 is increased, the weight 32c moves in a direction of moving away from the rotary shaft due to the centrifugal force. Accordingly, the slider 33 is pushed by the weight 32c, causing the stator core 38 to move. As a result, the facing area between the permanent magnet 31 and the stator core 38 is reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a generator that generates electric power using engine power and a vehicle including the same.

  Motorcycles, four-wheeled vehicles, and the like are provided with a generator that generates power using power generated by an engine. Such a generator is roughly classified into an inner rotor type in which a rotor is provided inside the stator core and an outer rotor type in which a rotor is provided outside the stator core. In recent years, an outer rotor type generator that can be reduced in size while maintaining a sufficient power generation amount is generally used.

  The amount of power generated by the generator as described above changes according to the rotational speed of the engine. FIG. 13 is a diagram showing an example of the relationship between the power generation amount of a conventional generator provided in a motorcycle and the rotational speed of the engine. In FIG. 13, the horizontal axis indicates the rotation speed, and the vertical axis indicates the power.

  In the example of FIG. 13, as indicated by the solid line A, the power generation amount of the generator is small in the region where the engine speed is low (around 1500 rpm), and suddenly increases when the engine speed increases to around 3000 rpm. It is rising.

  Here, for example, when the power consumption of the motorcycle is the value indicated by the alternate long and short dash line B, the difference between the value indicated by the solid line A and the value indicated by the alternate long and short dash line B is surplus power generation. In the example of FIG. 13, the surplus power generation amount in the low speed region is small, but the surplus power generation amount in the medium / high speed region is large. In this case, since the engine is loaded according to the amount of power generated by the generator, the power loss of the engine in the medium and high speed range increases. Thereby, the running stability in the middle and high speed range of the motorcycle is lowered.

  In addition, when the power generation capacity of the generator is reduced in order to reduce the surplus power generation amount in the medium and high speed range, the power generation amount in the low speed range is insufficient. As a result, malfunctions may occur in the electronic components of the motorcycle.

  Therefore, in order to solve the above-described problems, an outer rotor type generator that can adjust the amount of power generation according to the rotational speed of the engine has been developed (see, for example, Patent Document 1).

In the AC generator provided with the voltage control mechanism described in Patent Document 1, a plurality of permanent magnets are provided on the inner peripheral side of the rotor. The plurality of permanent magnets move to the outer peripheral side of the rotor by centrifugal force as the rotational speed of the rotor increases. In this case, the magnetic flux density between the stator yoke fixed inside the rotor and the rotor is lowered. Thereby, also when the rotational speed of a rotor increases, the increase in electric power generation can be suppressed.
JP-A-8-251894

  By the way, when moving a permanent magnet in the state where the rotational speed of a rotor is high, a vibration of a rotor and a permanent magnet becomes large. In this case, it is difficult to stabilize the magnetic flux density between the rotor and the stator yoke. Therefore, it becomes difficult to adjust the power generation amount of the generator.

  An object of the present invention is to provide a generator capable of stabilizing the amount of power generation while suppressing excessive power generation, and a vehicle including the same.

  (1) A generator according to a first aspect of the present invention is a generator that generates electric power using the rotational motion of a rotating shaft, and is fixed to the rotor that rotates about the rotating shaft according to the rotational motion of the rotating shaft. A magnet that rotates together with the rotor, a core that is movable between the rotating shaft and the magnet in the axial direction of the rotating shaft, a winding wound around the core, and a rotational speed of the rotating shaft. A moving mechanism is provided that moves the core in a first direction parallel to the axial direction so that the facing area between the magnet and the core decreases with an increase.

  According to this generator, the magnet fixed to the rotor and the rotor rotates according to the rotational movement of the rotating shaft. When the rotational speed of the rotating shaft increases, the core is moved in the first direction by the moving mechanism so that the facing area between the core and the magnet provided between the rotating shaft and the magnet decreases.

  As a result, when the rotating shaft rotates at a medium to high speed, the number of magnetic lines of force (magnetic flux density) passing through the core and the winding decreases. As a result, it is possible to suppress the amount of power generation during the middle and high speed rotation of the rotating shaft.

  Therefore, when this generator is provided in the vehicle, it is possible to prevent the power loss of the engine from becoming large when the vehicle is traveling at medium to high speed. Thereby, the running stability of the vehicle is improved.

  Moreover, in this generator, the facing area of a core and a magnet can be reduced by moving a core. That is, it is not necessary to move the magnet that is a rotating body. In this case, since the facing area can be changed in a state where the magnet is stabilized, it is possible to prevent the number of magnetic lines of force crossing the core from changing in an unstable manner. Thereby, the power generation amount of the generator can be sufficiently stabilized.

  (2) The moving mechanism may include a centrifugal governor mechanism.

  In this case, by using the centrifugal governor mechanism, the core can be moved without using a driving device such as a motor. Thereby, the manufacturing cost of a generator can be reduced. Further, the facing area between the core and the magnet can be easily and reliably adjusted according to the speed of the rotating shaft.

  (3) The generator may further include a biasing member that biases the core in a second direction opposite to the first direction.

  In this case, when the rotational speed of the rotating shaft decreases after the core is moved in the first direction by the moving mechanism, the core can be easily moved in the second direction. Thereby, appropriate power generation according to the rotational speed of the rotating shaft can be performed. As a result, the power generation amount of the generator can be reliably stabilized.

  (4) A vehicle according to a second invention includes drive wheels, an engine, a power transmission mechanism for transmitting power generated by the engine to the drive wheels, and a generator according to the first invention. .

  In this vehicle, the power generated by the engine is transmitted to the drive wheels via a power transmission mechanism. Thereby, the driving wheel is driven.

  In this vehicle, the generator according to the first invention is provided. In this case, the facing area between the magnet and the core of the generator decreases as the rotational speed of the engine increases. Thereby, when the engine is rotating at medium and high speeds, the number of magnetic lines of force (magnetic flux density) passing through the core and the windings decreases. As a result, it is possible to suppress the amount of power generated during medium and high speed rotation of the engine.

  Therefore, it is possible to prevent the power loss of the engine from increasing when the vehicle is traveling at a medium to high speed. Thereby, the running stability of the vehicle is improved.

  Moreover, in this generator, the facing area of a core and a magnet can be reduced by moving a core. That is, it is not necessary to move the magnet that is a rotating body. In this case, since the facing area can be changed in a state where the magnet is stabilized, it is possible to prevent the number of magnetic lines of force crossing the core from changing in an unstable manner. Thereby, the power generation amount of the generator can be sufficiently stabilized. As a result, the running stability of the vehicle is further improved.

  (5) The power transmission mechanism includes a centrifugal clutch, and the moving mechanism moves the core from the first position to the second position according to an increase in the rotational speed of the rotating shaft before the centrifugal clutch is connected. Also good.

  In this case, since the core is moved before the centrifugal clutch is connected, it is possible to prevent excessive power generation in the generator when the vehicle is traveling. Thereby, it is possible to prevent large power generation braking from occurring in the generator when the vehicle is traveling. As a result, it is possible to prevent the vehicle from receiving an impact based on fluctuations in engine power loss, and the driver can drive the vehicle comfortably and safely.

  (6) The power transmission mechanism includes a centrifugal clutch, and the moving mechanism moves the core from the first position to the second position in accordance with an increase in the rotation speed of the rotating shaft before the centrifugal clutch starts the connection operation. You may let them.

  In this case, the core is moved before the centrifugal clutch enters the half-clutch state. That is, the core is moved before the vehicle starts. Thereby, it is possible to prevent excessive power generation in the generator when the vehicle starts. As a result, it is possible to prevent large generator braking from occurring at the generator when the vehicle starts, and the vehicle can start smoothly.

  (7) The power transmission mechanism includes a centrifugal clutch, and the moving mechanism moves the core from the first position to the second position in response to an increase in the rotation speed of the rotation shaft and decreases the rotation speed of the rotation shaft. Accordingly, the core may be moved from the second position to the first position while the centrifugal clutch is disengaged.

  In this case, the core is returned to the original position while the centrifugal clutch is disengaged. Therefore, it is possible to prevent the rotational speed of the drive wheels from changing suddenly even when power generation braking occurs in the generator due to the return of the core to the original position and the rotational speed of the engine decreases. As a result, it is possible to prevent an impact from occurring on the vehicle, and the safety of the vehicle is improved.

  ADVANTAGE OF THE INVENTION According to this invention, the electric power generation amount at the time of middle high speed rotation of a generator can be suppressed. Moreover, since it is not necessary to move the magnet which is a rotary body, the electric power generation amount of a generator can fully be stabilized. Further, when this generator is provided in the vehicle, it is possible to prevent an increase in engine power loss when the vehicle is traveling at a medium to high speed. Thereby, the running stability of the vehicle is improved.

  Hereinafter, a generator according to an embodiment of the present invention and a motorcycle including the generator will be described with reference to the drawings.

(1) Structure of Motorcycle FIG. 1 is a schematic side view of a motorcycle according to an embodiment of the present invention. In the following description, front, rear, left, and right mean front, rear, left, and right when viewed in a state where the user is seated on a motorcycle seat.

  As shown in FIG. 1, a motorcycle 100 according to the present embodiment includes a body frame 10. A head pipe 11 is formed in front of the body frame 10. A steering shaft 11S is attached to the head pipe 11 so as to be swingable in the left-right direction. A handle 14 is attached to the upper end of the steering shaft 11S.

  A front fork 12 that rotatably supports the front wheel 13 is connected to the steering shaft 11S. As a result, the front fork 12 swings in the left-right direction in accordance with the operation of the handle 14 by the rider.

  A seat 15 including a main seat 15a and a tandem seat 15b is provided on the upper portion of the body frame 10. An engine 20 is attached to a part of the body frame 10 at a substantially central portion of the motorcycle 100 in the front-rear direction. The engine 20 is integrally attached to a swing arm (not shown) together with the power transmission system 70.

  A rear wheel 16 is rotatably provided at one end of a swing arm (not shown). The engine 20 and the rear wheel 16 are connected through a power transmission system. As a result, the rear wheel 16 can rotate as the engine 20 rotates.

  In FIG. 1, as indicated by arrows X, Y, and Z, three directions orthogonal to each other are defined as an X direction, a Y direction, and a Z direction. That is, in FIG. 1, the left-right direction of the motorcycle 100 is defined as the X direction, the front-rear direction of the motorcycle 100 is defined as the Y direction, and the up-down direction of the motorcycle 100 is defined as the Z direction. In the subsequent drawings, three directions orthogonal to each other are defined as an X direction, a Y direction, and a Z direction.

(2) Engine and Power Transmission System FIG. 2 is a diagram showing the structure of the engine 20 and the power transmission system 70 of FIG.

  As shown in FIG. 2, the engine 20 includes a cylinder 21, a piston 22, a connecting rod 23, and two cranks 24a and 24b. One ends of crankshafts 251 and 252 are fixed to the cranks 24a and 24b, respectively. The other end of the crankshaft 251 is connected to the generator 30. In the generator 30, power generation is performed using the rotational force of the crankshaft 251. Details of the generator 30 will be described later.

  A connecting gear 26 is fixed to the other end of the crankshaft 252. The rotational force of the crankshaft 252 is transmitted to the centrifugal clutch 40 via the connection gear 26. One end of a first transmission shaft 41 is connected to the centrifugal clutch 40. The centrifugal clutch 40 is disconnected when the engine 20 is not operating, and is connected when the rotational speed of the engine 20 increases. Thereby, the rotational force of the crankshaft 252 is transmitted to the first transmission shaft 41.

  A side gear 42 is fixed to the other end of the first transmission shaft 41. The side gear 42 meshes with a side gear 44 fixed to one end of the second transmission shaft 43. Thereby, the rotational force of the first transmission shaft 42 is transmitted to the second transmission shaft 43.

  The other end of the second transmission shaft 43 is connected to one end of the propeller shaft 46 via a universal joint 45. A side gear 47 is fixed to the other end of the propeller shaft 46. The side gear 47 is in mesh with the ring gear 48. One end of a drive shaft 49 is fixed to the ring gear 48. The rotational force of the propeller shaft 46 is transmitted to the drive shaft 49 via the side gear 47 and the ring gear 48. The rear wheel 16 in FIG. 1 is connected to the other end of the drive shaft 49.

  With the configuration as described above, the rotational force generated by the engine 20 is transmitted to the rear wheel 16 in FIG. 1, and the rear wheel 16 is driven.

(3) Generator FIG. 3 is an assembled perspective view showing the generator 30 of FIG. 1, and FIGS. 4 and 5 are longitudinal sectional views of the generator 30. 4 shows the state of the generator 30 when the engine 20 is idling, and FIG. 5 shows the state of the generator 30 when the engine 20 rotates at high speed.

  As shown in FIGS. 3 to 5, the generator 30 includes a rotor 31, a first guide member 32, a slider 33, a thrust bearing 34, a washer 35, a fixing pin 36, a second guide member 37, a stator core 38, a spring. A member 381 and a cover member 39 are included.

  The rotor 31 has a cylindrical shape with one side opened. A cylindrical permanent magnet 31 a is fixed to the inner peripheral surface of the rotor 31. A shaft fixing member 31 b is fixed to the outside of the lower portion of the rotor 31. The shaft fixing member 31 b has a cylindrical portion 311 and a flange portion 312. The crankshaft 251 is fixed to the cylindrical portion 311 by a nut 25a and a washer 25b.

  The first guide member 32 has a disk shape. A through hole 32 a is formed at the center of the first guide member 32. The crankshaft 251 and the cylindrical portion 311 are inserted through the through hole 32a. The flange portion 312 of the shaft fixing member 31b, the rotor 31, and the first guide member 32 are fixed by bolts (not shown). Accordingly, the rotor 31 and the first guide member 32 rotate with the rotation of the crankshaft 251.

  Six guide grooves 32b are formed on one surface of the first guide member 32 so as to extend in the radial direction. As shown in FIGS. 4 and 5, the guide groove 32b is formed so as to become deeper toward the central axis. A spherical weight 32c is movably provided in the guide groove 32b.

  As shown in FIGS. 3 to 5, the slider 33 has a cylindrical portion 331 and a flange portion 332. The slider 33 is rotatably provided on one side of the first guide member 32 such that the crankshaft 251 and the cylindrical portion 311 of the shaft fixing member 31b are inserted into the cylindrical portion 331. The thrust bearing 34 and the washer 35 are rotatably fitted to the outer peripheral portion of the cylindrical portion 331 of the slider 33.

  The second guide member 37 has a first cylindrical portion 37a and a second cylindrical portion 37b having a diameter larger than that of the first cylindrical portion 37a. As shown in FIG. 4, the second guide member 37 is fixed to the cover member 39 by a fixing pin 36.

  As shown in FIGS. 3 to 5, a conductive wire 38 a is wound around the stator core 38. The stator core 38 is fixed to the outer peripheral portion of the cylindrical support member 382. The support member 382 is attached to the outer peripheral portion of the second cylindrical portion 37b of the second guide member 37 so as to be movable in the axial direction.

  On one surface of the support member 382, four substantially fan-shaped spring holding portions 38b are provided. A spring holding hole 38c is formed in the substantially central portion of the spring holding portion 38b. The four spring members 381 are provided between the support member 382 and the cover member 39 so that one end contacts the cover member 39 and the other end contacts the bottom of the spring holding hole 38c. As a result, the stator core 38, the washer 35, the thrust bearing 34, and the slider 33 are biased in a direction away from the cover member 39.

(4) Operation of generator When centrifugal speed of engine 20 is low, a large centrifugal force does not act on weight 32c. Therefore, the resultant force of the elastic force of the spring member 381 and the magnetic force between the permanent magnet 31a and the stator core 38 becomes larger than the centrifugal force of the weight 32c. In this case, as shown in FIG. 4, the stator core 38, the washer 35, the thrust bearing 34, and the slider 33 are held at a position where the flange 332 and the first guide member 32 are closest to each other (hereinafter referred to as a reference position). Is done. The diameter of the weight 32c is set to a value slightly larger than the maximum depth of the guide groove 32b. Therefore, the flange 332 and the first guide member 32 are not in contact with each other even at the reference position.

  In a state where the engine 20 is operating normally (for example, when the motorcycle 100 is running), the weight 32c rotates at a high speed around the crankshaft 251. Thereby, the centrifugal force acting on the weight 32c is increased. In this case, a force is applied to the weight 32c to move in the direction away from the central axis in the guide groove 32b.

  As described above, the guide groove 32b is formed so as to become shallower as the distance from the central axis increases. Therefore, as shown in FIG. 5, when the weight 32 c moves in the guide groove 32 b in a direction away from the central axis, one part of the first guide member 32 is pressed while a part of the weight 32 c pushes the slider 33. It protrudes from the surface to the cover member 39 side. As a result, the stator core 38, the washer 35, the thrust bearing 34, and the slider 33 move in a direction approaching the cover member 39.

  Thus, in the present embodiment, when the rotational speed of the engine 20 increases, the stator core 38 is moved in the direction approaching the cover member 39 by the centrifugal force acting on the weight 32c. Thereby, the opposing area of the stator core 38 and the permanent magnet 31a decreases. In this case, the number of lines of magnetic force crossing the stator core 38 is reduced (magnetic flux density is reduced). Therefore, even when the rotational speed of the engine 20 (rotor 31) increases, the power generation amount of the generator 30 can be suppressed.

  The relationship between the facing area between the stator core 38 and the permanent magnet 31a and the rotational speed of the engine 20 can be adjusted by the spring constant of the spring member 381, the weight of the weight 32c, the shape of the guide groove 32b, and the like. Thereby, it becomes possible to adjust the electric power generation amount of the generator 30 appropriately according to use conditions. The details of the relationship between the facing area between the stator core 38 and the permanent magnet 31a and the rotational speed of the engine 20 will be described later.

(5) Effect As described above, in the present embodiment, as the rotational speed of the engine 20 increases, the facing area between the stator core 38 and the permanent magnet 31a decreases. Therefore, it is possible to prevent excessive power generation in the generator 30 during the medium-high speed rotation of the engine 20. Thereby, the running stability of the vehicle is improved.

  In the present embodiment, the power generation amount of the generator 30 is adjusted by moving the stator core 38. In this case, since the stator core 38 is not rotating, it is possible to prevent vibrations from occurring during movement. Moreover, since the permanent magnet 31a which is a rotary body does not move, it can prevent that a vibration generate | occur | produces in the permanent magnet 31a. As a result, when the stator core 38 is moved, it is possible to prevent the change in the number of magnetic lines of force (magnetic flux density) crossing the stator core 38 from becoming unstable. Thereby, the electric power generation amount of the generator 30 can be adjusted appropriately.

  Further, in the present embodiment, the movement of the weight 32c due to centrifugal force converts the rotational motion of the crankshaft 251 into motion in the direction of the rotational axis, thereby moving the stator core 38. That is, the stator core 38 can be moved without using a driving device such as a motor. As a result, the manufacturing cost of the motorcycle 100 can be reduced.

  Further, in the present embodiment, the inertial force of the rotor 31 is also obtained when the load on the engine 20 increases due to the dynamic braking that occurs when the stator core 38 returns to the reference position (when the power loss of the engine 20 occurs). Therefore, the rotor 31 can be prevented from stopping. Thereby, it is possible to prevent the engine 20 from stopping. As a result, the driver can drive the motorcycle 100 comfortably and safely.

(6) Other Examples of Power Transmission System (6-1) Examples Using Chains FIG. 6 is a diagram illustrating another example of the power transmission system 70 of FIG. The power transmission system 70 in FIG. 6 differs from the power transmission system 70 in FIG. 2 in the following points.

  In the power transmission system 70 of FIG. 6, the other end of the crankshaft 252 is connected to the generator 30. The other end of the crankshaft 251 is connected to the centrifugal clutch 40. A first sprocket 51 is fixed to the centrifugal clutch 40. When the rotational speed of the crankshaft 251 increases and the centrifugal clutch 40 is connected, the first sprocket 51 rotates.

  A transmission shaft 52 is provided behind the crankshaft 251. A second sprocket 53 is fixed to the transmission shaft 52. A chain 54 is bridged between the first and second sprockets 51 and 53. The rotational motion of the first sprocket 51 is transmitted to the second sprocket 53 via the chain 54. Thereby, the transmission shaft 52 rotates.

  A drive shaft 55 is provided behind the transmission shaft 52. The rear wheel 16 of FIG. 1 is connected to one end of the drive shaft 55. A connection gear 56 is fixed to the drive shaft 55. The rotational movement of the transmission shaft 52 is transmitted to the drive shaft 55 via the connection gear 56. Thereby, the drive shaft 55 rotates.

  With the configuration as described above, the rotational force generated by the engine 20 is transmitted to the rear wheel 16 in FIG. 1, and the rear wheel 16 is driven.

(6-2) Example Using Belt FIG. 7 is a diagram showing another example of the power transmission system 70 of FIG. The power transmission system of FIG. 7 differs from the power transmission system of FIG. 2 in the following points.

  In the power transmission system 70 of FIG. 7, a crankshaft 251 is provided so as to penetrate the generator 30. Specifically, the crankshaft 251 is provided so as to penetrate the cover member 39 and the second guide member 37 of FIG. A first pulley 61 is fixed to the other end of the crankshaft 251. When the crankshaft 251 rotates, the first pulley 61 rotates.

  A transmission shaft 62 is provided behind the crankshaft 251. A second pulley 63 is rotatably provided on the transmission shaft 62. A belt 64 is bridged between the first and second pulleys 61 and 63. The rotational movement of the first pulley 61 is transmitted to the second pulley 63 via the belt 64.

  A centrifugal clutch 40 is provided at one end of the transmission shaft 62. The rotational motion of the second pulley 63 is transmitted to the centrifugal clutch 40 via a predetermined transmission mechanism. When the rotational speed of the second pulley 63 increases and the centrifugal clutch 40 is connected, the transmission shaft 62 rotates.

  A transmission shaft 68 is provided behind the transmission shaft 62. A connection gear 65 is fixed to one end of the transmission shaft. The rotational motion of the transmission shaft 62 is transmitted to the transmission shaft 68 via the connecting gear 65. Thereby, the transmission shaft 68 rotates.

  A drive shaft 66 is provided behind the transmission shaft 68. A connection gear 67 is fixed to one end of the drive shaft 66. The rear wheel 16 is connected to the other end of the drive shaft 66. The rotational motion of the transmission shaft 68 is transmitted to the drive shaft 66 through the connection gear 67. Thereby, the drive shaft 66 rotates.

  With the configuration described above, the rotational force generated by the engine 20 is transmitted to the rear wheel 16 and the rear wheel 16 is driven.

(6-3) Relationship between Permanent Magnet of Rotor and Stator Core As described above, in the above embodiment, the permanent magnet 31a (see FIG. 4) can be changed by changing the spring constant of the spring member 381 (FIG. 4). 3, 4 and 5) and the facing area between the stator core 38 (FIGS. 3, 4 and 5) can be adjusted. Hereinafter, an adjustment method according to use conditions will be described with an example.

(A) Basic Example FIG. 8 is a diagram showing an example of the relationship between the facing area between the permanent magnet 31a and the stator core 38 (hereinafter abbreviated as facing area) and the rotational speed of the engine 20 (FIG. 1).

  In FIG. 8 and FIGS. 9 to 11 described later, the vertical axis indicates the facing area, and the horizontal axis indicates the rotational speed of the engine 20. 8 to 11, the value r1 indicates the idle rotation speed of the engine 20, and the value r2 indicates the rotation speed of the engine 20 at the start of connection of the centrifugal clutch 40 (see FIGS. 2, 6, and 7). The value r3 indicates the rotational speed of the engine 20 at the time when the centrifugal clutch 40 is completely connected. That is, the centrifugal clutch 40 is in a half-clutch state between the values r2 and r3.

  8 to 11, the solid line indicates the change in the facing area in the process of increasing the rotational speed of the engine 20, and the alternate long and short dash line indicates the change in the facing area in the process of decreasing the rotating speed of the engine 20.

  In the example of FIG. 8, the facing area decreases after the rotational speed of the engine 20 exceeds the value r3. That is, after the centrifugal clutch 40 is connected, the stator core 38 starts moving from the reference position (the state shown in FIG. 4). Hereinafter, the rotational speed of the engine 20 when the stator core 38 starts moving from the reference position is referred to as a start speed. Further, the stator core 38 has returned to the reference position in a state where the rotational speed of the engine 20 is lower than the start speed. Hereinafter, the rotational speed of the engine 20 when the stator core 38 returns to the reference position is referred to as a return speed.

  Here, in the example of FIG. 8, hysteresis is formed in the change in the facing area. In this case, even if a fluctuation occurs in the rotation speed of the engine 20, if the hysteresis is larger than the fluctuation width, the weight 32c (FIG. 4) can be prevented from vibrating. Thereby, it can prevent that a vibration generate | occur | produces in the generator 30 (FIG. 4).

  In this example, the difference between the start speed and the return speed is reduced by adjusting the spring constant of the spring member 381 (FIG. 4), the weight of the weight 32c, the shape of the guide groove 32b (FIG. 4), and the like. be able to. In this case, the region of the rotational speed of the engine 20 where the weight 32c moves due to the centrifugal force is narrowed.

  Here, when the weight 32c is moving, the generator 30 may vibrate. Therefore, the rotational speed of the engine 20 may not be stable. Therefore, by reducing the difference between the start speed and the return speed, the rotational speed region of the engine 20 in which vibration is generated in the generator 30 can be narrowed. Thereby, the behavior of the engine 20 can be stabilized.

  In this example, the hysteresis of the facing area can be reduced by oil lubrication or the like. In this case, the difference between the position of the stator core 38 when the rotational speed is increased and the position of the stator core 38 when the rotational speed is decreased can be reduced at any rotational speed of the engine 20. Thereby, even when vibration is generated in the generator 30 while the weight 32c is moving, the weight 32c can be prevented from greatly vibrating. As a result, the behavior of the weight 32c can be stabilized, and fluctuations in power loss of the engine 20 can be suppressed.

  In the belt-type power transmission system 70 as described in FIG. 7, the impact (engine) generated in the power transmission system 70 in the belt (FIG. 7) and the first and second pulleys 61 and 63 (FIG. 7). Impact and the like based on a change in power loss of 20) can be mitigated. Therefore, as in the example of FIG. 8, even when the stator core 38 returns to the reference position with the centrifugal clutch 40 connected, it is possible to mitigate the impact based on the power generation braking and the like generated in the generator 30. Thus, the driver can drive the motorcycle 100 comfortably and safely.

(B) Example of Engine Rotation Speed at End of Stator Core Moving Operation FIG. 9 is a diagram showing another example of the relationship between the facing area and the engine 20 rotation speed.

  In this example, when the rotational speed of the engine 20 increases, the facing area reaches the minimum value before the rotational speed of the engine 20 reaches the value r3. In this case, it is possible to reliably prevent the generator 30 from generating excessive power when the centrifugal clutch 40 is connected, that is, when the motorcycle 100 is traveling. Accordingly, it is possible to prevent a large power generation braking from being generated in the generator 30 when the motorcycle 100 is traveling. As a result, the rotational speed of the engine 20 is stabilized, and the driver can drive the motorcycle 100 comfortably and safely.

  Further, the relationship shown in FIG. 9 can be effectively applied to the shaft type power transmission system 70 (FIG. 2) or the chain type power transmission system 70 (FIG. 6).

  Here, in the shaft-type or chain-type power transmission system 70, when the centrifugal clutch 40 is connected, the impact based on the power loss of the engine 20 is transmitted to the rear wheel 16 (FIG. 1) without being alleviated. The Therefore, as shown in FIG. 9, the movement of the stator core 38 is completed before the centrifugal clutch 40 is completely connected, thereby preventing the impact based on the power loss of the engine 20 from being transmitted to the rear wheel 16. be able to. As a result, it is possible to prevent the motorcycle 100 from generating an impact, and the traveling safety of the motorcycle 100 is improved.

(C) Example of Engine Rotation Speed at Start of Stator Core Movement Operation FIG. 10 is a diagram illustrating another example of the relationship between the facing area and the rotation speed of the engine 20.

  In this example, when the rotational speed of the engine 20 increases, the facing area reaches the minimum value before the rotational speed of the engine 20 reaches the value r2. In this case, the movement of the stator core 38 is completed before the centrifugal clutch 40 enters the half-clutch state. That is, the movement of the stator core 38 is completed before the motorcycle 100 starts. In this case, it is possible to reliably prevent excessive power generation in the generator 30 when the motorcycle 100 starts. In addition, when the motorcycle 100 starts, it is possible to prevent large generator braking from occurring in the generator 30. As a result, the motorcycle 100 can be started smoothly.

  Further, the relationship shown in FIG. 10 can be effectively applied to the shaft type power transmission system 70 (FIG. 2) or the chain type power transmission system 70 (FIG. 6), similarly to the relationship shown in FIG. .

  As shown in FIG. 10, the movement of the stator core 38 is completed before the connection operation of the centrifugal clutch 40 is started, thereby reliably preventing an impact based on the power loss of the engine 20 from being transmitted to the rear wheel 16. can do. As a result, it is possible to reliably prevent the motorcycle 100 from generating an impact, and the traveling safety of the motorcycle 100 is further improved.

(D) Example when Limiting Movement of Weight FIG. 11 is a diagram illustrating another example of the relationship between the facing area and the rotational speed of the engine 20 when the movement of the weight 32c is limited. FIG. 12 shows an example of a method for limiting the movement of the weight 32c.

  As shown in FIG. 12, in this example, a protrusion 90 is formed at a substantially central portion of the bottom surface of the guide groove 32b. In this case, the movement of the weight 32c is restricted at the protrusion 90. Specifically, as shown in FIG. 11, when the rotational speed of the engine 20 is increased, the facing area rapidly decreases when the weight 32 c exceeds the protrusion 90. Thereafter, the facing area gradually decreases.

  Further, when the rotational speed of the engine 20 is reduced, the facing area increases rapidly when the weight 32c exceeds the protrusion 90. Thereafter, the facing area increases gradually.

  In this way, by limiting the movement of the weight 32c, it is possible to increase the hysteresis of the change in the facing area. Thereby, it becomes possible to apply the generator 30 to more various use conditions.

  In this example, when the rotational speed of the engine 20 decreases, the stator core 38 returns to the reference position while the rotational speed of the engine 20 is equal to or less than the value r2. That is, the stator core 38 returns to the reference position with the centrifugal clutch 40 disconnected. Thereby, even when the power loss of the engine 20 is suddenly changed by returning the stator core 38 to the reference position, it is possible to prevent the rotational speed of the rear wheel 16 from rapidly decreasing. As a result, it is possible to prevent the motorcycle 100 from being impacted, and the safety of the motorcycle 100 is further improved.

  In this example, the movement of the weight 32c is restricted by the protrusion 90. In this case, the movement of the weight 32c is less affected by the oil in the power transmission system 70 than when the movement of the weight 32c is limited by increasing the coefficient of friction between the guide groove 32b and the weight 32c. Therefore, even when the oil temperature rises, it is possible to prevent the hysteresis of the change in the facing area from changing.

  In this example, the movement of the weight 32c is restricted by one protrusion 90, but a plurality of protrusions may be provided, and the movement of the weight 32c is restricted by providing one or more recesses. May be.

(7) Other Embodiments In the above embodiment, the spring member 381 is provided. However, if the magnetic force acting between the permanent magnet 31a and the stator core 38 is sufficiently large, the spring member 381 may not be provided. Good.

  In the above embodiment, the motorcycle 100 has been described as an example of a vehicle to which the generator 30 is applied. However, the generator 30 is applied to other vehicles such as an automatic tricycle and a saddle-ride type automobile. May be.

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

  In the above embodiment, the crankshaft 251 or the crankshaft 252 is an example of a rotating shaft, the permanent magnet 31a is an example of a magnet, the stator core 38 is an example of a core, and the conducting wire 38a is an example of a winding, The first guide member 32 and the weight 32c are examples of a moving mechanism, the spring member 381 is an example of an urging member, the rear wheel 16 is an example of a driving wheel, and the power transmission system 70 is an example of a power transmission mechanism. It is.

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

  The present invention can be effectively used as a generator for various vehicles.

1 is a schematic side view of a motorcycle according to an embodiment of the present invention. It is a figure which shows the structure of the engine and power transmission system of FIG. It is an assembly perspective view which shows the generator of FIG. It is a longitudinal cross-sectional view of a generator. It is a longitudinal cross-sectional view of a generator. It is a figure which shows the other example of the power transmission system of FIG. It is a figure which shows the other example of the power transmission system of FIG. It is a figure which shows an example of the relationship between an opposing area and the rotational speed of an engine. It is a figure which shows an example of the relationship between an opposing area and the rotational speed of an engine. It is a figure which shows an example of the relationship between an opposing area and the rotational speed of an engine. It is a figure which shows an example of the relationship between an opposing area and the rotational speed of an engine. It is a figure which shows an example of the method for restrict | limiting the movement of a weight. It is a figure which shows an example of the relationship between the electric power generation amount of the conventional generator, and the rotational speed of an engine.

Explanation of symbols

16 Rear wheel 20 Engine 30 Generator 31 Rotor 31a Permanent magnet 32 First guide member 32c Weight 38 Stator core 38a Conductor 70 Power transmission system 100 Motorcycle 251, 252 Crankshaft 381 Spring member

Claims (7)

A generator that generates electricity using the rotational motion of a rotating shaft,
A rotor that rotates about the rotational axis according to the rotational motion of the rotational axis;
A magnet fixed to the rotor and rotating together with the rotor;
A core provided to be movable with respect to the axial direction of the rotary shaft between the rotary shaft and the magnet;
A winding wound around the core;
And a moving mechanism that moves the core in a first direction parallel to the axial direction so that the facing area between the magnet and the core decreases as the rotational speed of the rotating shaft increases. And the generator. The generator according to claim 1, wherein the moving mechanism includes a centrifugal governor mechanism. The generator according to claim 1, further comprising a biasing member that biases the core in a second direction opposite to the first direction. Drive wheels,
Engine,
A power transmission mechanism for transmitting power generated by the engine to the drive wheels;
A vehicle comprising the generator according to claim 1. The power transmission mechanism includes a centrifugal clutch,
The said moving mechanism moves the said core from a 1st position to a 2nd position according to the increase in the rotational speed of the said rotating shaft, before the said centrifugal clutch is connected. vehicle. The power transmission mechanism includes a centrifugal clutch,
5. The moving mechanism moves the core from a first position to a second position in accordance with an increase in rotational speed of the rotating shaft before the centrifugal clutch starts a connection operation. Or the vehicle of 5. The power transmission mechanism includes a centrifugal clutch,
The moving mechanism moves the core from the first position to the second position according to an increase in the rotation speed of the rotation shaft, and the centrifugal clutch is disconnected according to a decrease in the rotation speed of the rotation shaft. The vehicle according to any one of claims 4 to 6, wherein the core is moved from the second position to the first position in a state where the core is in a state of being on the vehicle.

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