JP6548103B2 - Motor drive unit and electrically assisted bicycle - Google Patents

Description

  The present invention relates to a motor drive unit and an electrically assisted bicycle capable of traveling by adding an auxiliary driving force generated by a motor to a manual driving force by a pedaling force from a pedal.

  By having a motor supplied with power from a capacitor such as a battery, and detecting a human driving force consisting of a stepping force applied to a pedal by a torque sensor, and adding an auxiliary driving force (assisting force) of the motor corresponding to the human driving force, There are already known electrically assisted bicycles that can easily travel on uphills and the like.

  For example, as shown in FIG. 14, in the electrically assisted bicycle, there is one in which a motor drive unit 102 having a motor 101 and the like built therein is disposed at a location where a crankshaft 103 is provided (Patent Document 1 etc.). In the power-assisted bicycle 100 having such a configuration, the motor drive unit 102 having a relatively large weight is disposed at a low position in the center in the front-rear direction of the power-assisted bicycle 100 (that is, in the middle between the front and rear wheels) Ru. Therefore, the motor-assisted bicycle 100 with this arrangement configuration can lift the front wheel 110 and the rear wheel 111 more easily than the one in which the motor is built in the front wheel hub and the rear wheel hub, and there is a step on the traveling path. However, the vehicle body 113 can be easily maneuvered, so that the vehicle body 113 can be well managed, and the running stability is also good.

  Further, in such a motor drive unit 102, as shown in FIGS. 15 and 16, the outer peripheral surface of the human power transmission member (intermediate shaft) 104 to which the human power driving force from the crankshaft 103 is transmitted and the opposing portion thereof. There is a structure in which a magnetostrictive torque sensor 105 for detecting a human driving force is provided. That is, the magnetostriction generation unit 105a is formed on the outer peripheral surface of the human power transmission member 104, and the coil 105b for detecting the fluctuation of the magnet is disposed in a non-contact state so as to face the magnetostriction generation unit 105a. . Then, when the left and right pedals 112 (see FIG. 14) are depressed, the crank shaft 103 is twisted by the stepping force (hand drive force), so that the twist state of the hand transmission member 104 to which the hand drive force from the crank shaft 103 is transmitted. Is detected by the torque sensor 105.

  In FIG. 15 and FIG. 16, reference numeral 106 denotes an interlocking body (inner part) connected to a cylindrical body (outer part) 109 fitted to the human power transmitting body 104 via a one-way clutch (claw member) 107 Reference numeral 108 denotes a driving sprocket as a driving force output wheel mounted at the end of the interlocking body 106.

  Here, in the motor drive unit of the electrically assisted bicycle, as disclosed in, for example, Patent Document 2, there is also a structure of mechanically detecting a torque (human power). However, with such a structure, the parts come into contact with each other at the point where torque is detected, for example, to cause mechanical resistance, so the remaining capacity for output of the battery is exhausted and the auxiliary driving force can not be added. In some cases, there is a disadvantage that the burden on the passenger is large.

  On the other hand, in the motor drive unit 102 that detects torque (human driving force) by the magnetostrictive torque sensor 105 as shown in FIGS. 14 to 16, the coil 105b that detects torque (human driving force) generates magnetostriction. It is arrange | positioned non-contactingly with respect to the part 105a. Therefore, there is almost no burden on the passenger even when the remaining capacity for output of the battery is exhausted and the auxiliary driving force can not be added.

  Further, in the motor drive unit 102, since the magnetostriction generator 105a is formed on the human power transmission member 104 separate from the crankshaft 103, the following advantages are also obtained. That is, not only the torque (the manual driving force) in the rotational direction but also a part of the weight from the rider's foot is applied downward to the both ends of the crankshaft 103 from the foot of the passenger via the pedal 112 to bend the crankshaft 103 Bending stress is exerted. Therefore, when the magnetostriction generating portion is formed on the crankshaft, this bending stress may become a disturbance factor or noise when detecting torque (human driving force), and the torque detection capability may be reduced. In addition, since the material of the crankshaft must be selected so that it can sufficiently cope with large bending stress, the material is extremely limited, and in some cases, it is necessary to use one with a low torque detection capability. There are times when you can not get it

  On the other hand, in the motor drive unit 102 shown in FIG. 14 to FIG. 16, since the magnetostriction generating portion 105 a is formed on the human power transmission body 104 separate from the crankshaft 103, bending stress is generated by the crankshaft 103. It is harder to act than that, and the torque detection capability can be improved as compared with the case where the magnetostrictive portion is formed on the crankshaft. Moreover, since the material suitable for forming the magnetostriction generation part 105a in the outer peripheral surface can be used as the human power transmission body 104, the torque detection capability can be improved also by this.

  Further, the one-way clutch (clutch member) 107 provided in the motor drive unit 102 is provided for the following reason. That is, in the conventional electrically-assisted bicycle of this type, even when the rider stops pedaling the pedal 112, the motor 101 is controlled to keep rotating for a while (in the case of performing so-called delay control). In this case, if the one-way clutch 107 is not provided, the auxiliary driving force from the motor 101 is transmitted to the crank shaft 103, and the pedal 112 tries to keep rotating freely. Therefore, the auxiliary driving force from the motor 101 is cut off by the one-way clutch 107 so that such a force does not act on the crankshaft 103 and the pedal 112.

  By the way, as described above, in the motor drive unit 102 provided with the magnetostrictive torque sensor 105, a rotation sensor 115 (see FIG. 16) for detecting the rotation of the crankshaft 103 or the like is provided. In the motor drive unit 102, the outer peripheral portion of the cylindrical body (outer portion) 109 engaged with the human power transmission member 104 is disposed to be exposed from the outside. If a rotation detection tooth, a permanent magnet, or the like is fixed to the outer peripheral portion of the cylindrical body (outer portion) 109 and a rotation detection tooth is formed, a permanent magnet and a coil are used as the rotation sensor 115 A so-called pickup sensor (magnetic sensor) is provided.

JP, 2009-208710, A JP 10-81292 A

  However, in the motor drive unit 102 shown in FIGS. 14 to 16, since the rotation sensor 115 and the permanent magnet etc. are disposed on the cylinder (outer portion) 109 near the magnetostrictive torque sensor 105, the torque As a disturbance factor or noise at the time of detecting (the manual drive force), there is a possibility that the detection capability of the torque may be reduced.

  SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and it is possible to detect a torque by a magnetostrictive torque sensor and detect a rotation of a crank shaft or the like while stopping the rider from pedaling. It is an object of the present invention to provide a motor drive unit and an electrically assisted bicycle capable of maintaining torque detection capability well without transmission of auxiliary driving force from the crank shaft to the crankshaft.

  In order to solve the above problems, the motor drive unit according to the present invention is a motor drive unit used for an electrically assisted bicycle that can travel by adding an auxiliary drive force generated by a motor to a manual drive force by pedal force from a pedal. A crank shaft passing through a unit case constituting the outer shell of the motor drive unit; a cylindrical human power transmission body disposed on the outer periphery of the crank shaft; and a rotation shaft substantially parallel to the crank shaft A reduction mechanism having a reduction gear supported thereon, a rotation shaft substantially parallel to the crankshaft, and a motor provided on the rotation shaft with a tooth portion meshing with the reduction gear, and controlling the motor The motor comprising: a control unit having a control substrate; and a connection member connecting the motor and the control substrate, wherein the unit case is divided by a dividing portion. A first space in which the rotor portion and the stator portion are disposed, and a second space in which the control substrate and the crankshaft are disposed, and the control substrate includes the motor Is disposed in the second space so as to have a region overlapping with the stator portion when the rotational axis of the shaft is viewed in the axial direction, and part of the second space between the region and the stator portion And the connecting member is disposed to pass through the space.

  Further, in the motor drive unit according to the present invention, an end portion of the control substrate on the opposite side to the crankshaft side in the control substrate is positioned in a direction away from the crankshaft from the rotation shaft of the reduction gear. .

  Further, in the motor drive unit according to the present invention, the control substrate is disposed in the unit case so that a substrate surface extends in a direction intersecting the crankshaft.

  Further, in the motor drive unit of the present invention, the reduction gear is located in the second space.

  Moreover, the motor drive unit of this invention is equipped with the rotation body which rotates with the said crankshaft, and the rotation detector which detects the rotation speed of the said rotation body.

  Further, in the motor drive unit of the present invention, the rotation detector and the rotating body are disposed in the second space.

  Further, in the motor drive unit of the present invention, the rotating body has a detected portion whose rotation is detected by the rotation detector, and the detected portion looks in a direction substantially orthogonal to the crankshaft direction. And the speed reducing gear.

  Further, in the motor drive unit according to the present invention, a torque sensor is provided on the outer periphery of the human power transmission body, and a magnetostrictive generation portion of the torque sensor is formed on the human power transmission body, and the magnetostrictive generation portion is formed. A coil is disposed on the outer periphery of the human power transmitter.

  Further, in the motor drive unit according to the present invention, the rotation shaft of the reduction gear is disposed on the first bearing disposed on the rotor portion side in the axial direction, and on the opposite side to the rotor portion side in the axial direction. Supported by a second bearing, and an inner diameter of the second bearing is smaller than an inner diameter of the first bearing.

  Further, in the motor drive unit of the present invention, the connection member is connected to the motor at a position in a direction away from the crankshaft from the rotation shaft of the reduction gear.

  Further, in order to solve the above problems, the electrically assisted bicycle according to the present invention includes a motor drive unit, a front wheel disposed on the front side of the electrically assisted bicycle, and a rear side disposed on the rearward side of the electrically assisted bicycle. And a battery for supplying power to the motor drive unit.

  Further, in the electrically powered bicycle according to the present invention, the axis of the reduction gear is disposed below the axis of the crankshaft and the axis of the motor in the vertical direction of the electrically assisted bicycle.

  Further, in the electrically powered bicycle according to the present invention, the battery is disposed closer to the rotation shaft of the motor than the crankshaft in the front and rear direction of the electrically powered bicycle, and in the vertical direction of the electrically powered bicycle It is disposed above the motor drive unit.

  In the electrically assisted bicycle of the present invention, the motor drive unit and the battery are disposed between the front wheel and the rear wheel.

  Further, the present invention is a motor drive unit used for an electrically assisted bicycle capable of traveling by adding an auxiliary drive force generated by a motor to a manual drive force by a pedaling force from a pedal, the outer shell of the motor drive unit On the outer periphery of the crankshaft, a motor having a crankshaft that passes through a unit case that constitutes a part, a motor having a rotation axis parallel to the crankshaft, a cylindrical human power transmission body disposed on the outer periphery of the crankshaft, and A composite body having a large diameter gear portion and combining the manual driving force transmitted through the manual power transmission body with the auxiliary driving force from the motor, and rotation of the rotation shaft of the motor A reduction mechanism having a rotation axis parallel to the crankshaft and transmitting a signal to the large-diameter gear portion, and a control printed circuit board disposed in the unit case; The control unit and the rotary shaft of the motor pass through, and are disposed in the unit case, on the side of the tooth portion provided on the rotary shaft of the motor with respect to the rotor portion of the motor, A first wall extending in a direction orthogonal to the rotation axis of the motor, and the control printed circuit board are disposed on the opposite side of the rotor of the motor with respect to the first wall, and the control When the printed circuit board is viewed from the axial direction of the rotation shaft of the motor, the printed circuit board is disposed so as to at least partially overlap the motor, the control unit is connected to the printed circuit board for control, and from the printed circuit board for control The connector may have a connecting member extending in the direction of the motor, and the connecting member may extend in the direction of the motor through the first wall.

  Further, according to the present invention, the reduction gear mechanism is disposed on the rotor portion side of the motor as viewed in a direction substantially orthogonal to the rotation shaft of the small diameter gear portion meshing with the large diameter gear portion and the small diameter gear portion. The reduction gear may include a reduction large-diameter gear that meshes with a tooth of the rotation shaft of the motor.

  Further, according to the present invention, the rotational driving force from the combined body is not transmitted to the motor between the reduction large-diameter gear portion and the large-diameter support shaft portion supporting the reduction large-diameter gear portion. A one-way clutch may be provided.

  The present invention further includes a rotation sensor for detecting the rotation of the human power transmitting body or the combined force body, and a torque sensor disposed on the outer periphery of the crankshaft, wherein the rotation sensor is in the crankshaft direction. It may be disposed between the torque sensor and the large diameter gear portion while being disposed at a position overlapping the reduction large diameter gear portion when viewed in a direction substantially orthogonal.

  Further, in the electrically assisted bicycle of the present invention, the motor drive unit having a motor is disposed at an intermediate position between the front wheel and the rear wheel, and the assist drive generated by the motor to the manual drive force by the pedaling force from the pedal. A power-assisted bicycle capable of traveling by applying a force, wherein the manual drive force is transmitted to an outer periphery of a crankshaft to which a manual drive force from a pedal is transmitted, and a torque for detecting the manual drive force A cylindrical human power transmission body in which a magnetostriction generating portion of the sensor is formed is disposed, and a manual driving force from the human power transmission body is transmitted from one end side to the outer periphery of the crankshaft, and the crankshaft and the other end side. An interlocked body having a coaxial drive power output wheel attached thereto is disposed, and the drive power from the interlock is endlessly wound around the drive power output wheel and the manual drive power output wheel. Through the driving force transmitter An intermediate cylinder engaged with the human power transmission body is provided on the outer periphery of the crankshaft so as to be transmitted to the rear wheel, and a one-way clutch is disposed between the intermediate cylinder and the interlocking body. A rotation detector is provided which detects the rotation of the intermediate cylinder or the human power transmitter, and an optical sensor is used as the rotation detector, and the rotation detection on the outer periphery of the intermediate cylinder or the human power transmitter In the position corresponding to the sensor, one rotation body is installed for blocking or reflecting the light of the light sensor, and the rotation detector is a position where the light sensor is 90 degrees out of phase of its output signal in the rotation direction of the rotation body Two of them are provided side by side, the intermediate cylinder is attached to the inside of the one-way clutch, and the position where the rotating body is attached is with respect to the radial direction centering on the axial center of the crankshaft. , Said one way Pitch and position disengaged with the interlocking member, or may be characterized in that from the reference position is a position where the inside.

  With this configuration, the torque can be detected by the magnetostrictive torque sensor, and the rotation of the intermediate cylinder or the human power transmitter can be detected by the rotation detector, and thus the rotation of the crankshaft or the pedal can be detected. Further, the one-way clutch disposed between the intermediate cylinder and the interlocking body can be configured so that the auxiliary driving force from the motor is not transmitted to the crankshaft when the rider stops pedaling. . In addition, since an optical sensor is used as a rotation detector for detecting the rotation of the intermediate cylinder or the human power transmission body, when a magnetic sensor is used as the rotation detector, torque (human driving force) is detected. It is possible to prevent the torque detection capability from becoming a disturbance factor or noise, and to detect the torque well.

  Further, the present invention may be characterized in that a rotating body for blocking or reflecting the light of the optical sensor is attached at a position corresponding to the rotation detector on the outer periphery of the intermediate cylinder or the human power transmitter. Here, as a method of detecting the rotation of the crankshaft, it is conceivable to provide the crankshaft with a rotating body for blocking or reflecting the light of the light sensor and to detect the light emitted to the rotating body. . However, as in the present configuration, by attaching a rotating body that blocks or reflects the light of the light sensor to the outer periphery of the intermediate cylinder or the human power transmitting body, the rotating body that blocks or reflects the light of the light sensor is cranked. The resolution of the rotation detector can be improved because it is disposed at a portion with a larger diameter than in the case where it is provided at the shaft. In addition, as a specific example of the rotating body, it is conceivable to configure the rotating body by a disk, a cylinder or the like in which the teeth are formed over the entire circumference, and to provide the emitting portion and the light receiving portion so as to sandwich the teeth. In this case, a disc or cylinder having a toothed portion is attached to an intermediate cylinder or a human power transmitting member having a diameter relatively larger than that of the crankshaft. Therefore, as a disc or a cylinder having a toothed portion Even if the dimension in the radial direction from the inner diameter portion to the outer diameter portion is not increased so much, the tooth portions can be formed more at relatively large diameter positions, and the tooth portions are formed at relatively small diameter positions The resolution of the rotation detector can be improved compared to the Further, in order to obtain the same resolution of the rotation detector in the case where the rotating body is attached to the crankshaft, the dimensions in the radial direction from the inner diameter portion to the outer diameter portion of the disk or cylinder formed with the tooth portion It is conceivable to make the size larger, but in this case, there is a possibility that the disc or the cylinder having the teeth formed may be easily deformed. On the other hand, by attaching the rotating body to the intermediate cylindrical body or the human power transmitting body disposed on the outer periphery of the crankshaft, the dimension in the radial direction from the inner diameter portion to the outer diameter portion is made too large. Since it is not necessary, the possibility of deformation of the rotating body can be minimized.

  Further, according to the present invention, as described above, one rotating body for blocking or reflecting the light of the optical sensor is attached at a position corresponding to the rotation detector on the outer periphery of the intermediate cylinder or the human power transmitter. The rotation detector may be characterized in that two light sensors are provided side by side at positions where the phase of the output signal differs by 90 degrees in the rotation direction of the rotating body. This configuration makes it possible to detect that the pedal is stopped or turned in the reverse direction.

  Further, according to the present invention, the interlocking body may combine the human-powered driving force transmitted through the human-power transmission body with the auxiliary driving force from the motor. Also, instead of this, an auxiliary driving force output wheel may be provided which is engaged with the endless driving force transmitting body to output the auxiliary driving force output from the motor.

  Further, according to the present invention, a reduction mechanism having a reduction gear portion and a reduction gear support shaft for supporting the reduction gear portion is disposed in the transmission path of the auxiliary driving force, and the reduction gear portion and the reduction gear portion A one-way clutch for disconnecting the manual drive force that does not transmit the manual drive force to the motor side may be disposed between the gear support shaft and the gear support shaft.

  With this configuration, the one-way clutch for disconnecting the manual drive force disposed between the reduction gear portion and the reduction gear support shaft even when the pedal is crawled and rotated when the remaining capacity of the battery is exhausted. Thus, it is not necessary to rotate the reduction gear or motor, and it is not necessary to apply an extra force to the pedal.

  Further, according to the present invention, the motor, the reduction mechanism, and the control unit are incorporated in the motor drive unit, and the motor and the control unit overlap in a side view and are disposed on opposite sides in the width direction. It may be a feature.

  According to this configuration, the area of the motor drive unit in a side view (the projected area in the lateral direction) can be reduced (the device can be made compact). In addition, since the motor and the control unit are disposed on the opposite side in the width direction in the motor drive unit, the control unit is not easily affected by the heat of the motor, and good reliability can be maintained.

  According to the present invention, a cylindrical human power transmitter having a magnetostrictive portion of a torque sensor for detecting a human drive force formed on the outer periphery of a crankshaft, and an intermediate cylinder engaged with the human power transmitter. And an intermediate cylinder that rotates integrally with the crankshaft without affecting the torque sensor by using an optical sensor as a rotation detector that detects the rotation of the intermediate cylinder or the human power transmission body. The rotation of the body or human power transmission member can be detected easily and reliably. In addition, although it is conceivable to use a torque sensor as a rotation detector as well, rotation can be detected easily and reliably and control is simplified as compared with the case where a torque sensor is used in this way. There is an advantage.

  In addition, by attaching a rotating body for blocking or reflecting the light of the optical sensor at a position corresponding to the rotation detector on the outer circumference of the intermediate cylinder or the human power transmission body, a relatively high resolution as a rotation detector You can get In addition, even when a disc or cylinder having teeth formed over the entire circumference is attached to the outer periphery of the intermediate cylindrical body or the human power transmitting body as the rotating body, the radial direction from the inner diameter portion to the outer diameter portion of the rotating body Since it is not necessary to make the size of the element too large, the possibility of deformation of the teeth and the like can be minimized, and good reliability can be maintained.

  Further, a reduction gear mechanism having a reduction gear portion and a reduction gear support shaft supporting the reduction gear portion is disposed in a transmission path of the auxiliary driving force, and the reduction gear portion and the reduction gear support shaft By installing a one-way clutch for disconnecting the manual drive force between the two and not transmitting the manual drive force to the motor side, even if the pedal is turned and rotated when the remaining capacity of the battery is exhausted, It is not necessary to rotate the gears or the motor, and it is not necessary to apply an extra force to the pedal (the so-called drag resistance can be extremely reduced).

  Further, the motor, the speed reduction mechanism, and the control unit are incorporated in the motor drive unit, and the motor and the control unit are disposed side by side in a side view and on opposite sides in a widthwise view in a front view (or plan view). By doing so, the area (projected area in the lateral direction) of the motor drive unit in a side view can be made particularly small (compacted) as a single-axis motor drive unit, and the control unit It becomes hard to be affected and can maintain good reliability.

Overall side view of the electrically assisted bicycle according to the embodiment of the present invention Partial cutaway side view of the same electric assist bicycle Side view of the motor drive unit of the same electrically assisted bicycle (drive sprocket omitted) The plane cross-sectional view of the motor drive unit of the same electric power assist bicycle (IV-IV arrow arrow plane sectional view of FIG. 3) Principal part enlarged plan cross-sectional view of motor drive unit of the same electric power assist bicycle Side view of the rotation detector and rotor of the motor drive unit of the same electrically assisted bicycle Diagram for explaining the operation of the rotation detector and the rotating body of the motor drive unit Diagram for explaining the operation of the rotation detector and the rotating body of the motor drive unit An enlarged plan cross-sectional view of a motor drive unit of an electrically assisted bicycle according to another embodiment of the present invention A partially cutaway side view of an electrically assisted bicycle according to another embodiment of the present invention Flat cross-sectional view of the motor drive unit of the same electric assist bicycle Principal part enlarged plan cross-sectional view of motor drive unit of the same electric power assist bicycle An enlarged plan cross-sectional view of an essential part of a motor drive unit in an electrically assisted bicycle according to still another embodiment of the present invention Side view of a conventional electrically assisted bicycle Plan sectional view of the motor drive unit in the conventional electrically assisted bicycle Principal cross-sectional plan view of a motor drive unit in the conventional electrically assisted bicycle

  Hereinafter, a motor drive unit and an electrically assisted bicycle according to an embodiment of the present invention will be described based on the drawings. In addition, the left-right direction and the front-back direction in the following description mean the direction in the state which got on the said electrically assisted bicycle 1 toward the advancing direction. Further, the configuration of the present invention is not limited to the configuration described below.

  1 and 2 in FIG. 1 indicate an electrically assisted bicycle according to the embodiment of the present invention. As shown in FIGS. 1 and 2, this electrically assisted bicycle 1 comprises a metal frame 2 comprising a head pipe 2a, a front fork 2b, a main pipe 2c, an upright pipe 2d, a chain stay 2e, a seat stay 2f and the like. A front wheel 3 rotatably mounted at the lower end of the front fork 2b, a rear wheel 4 rotatably mounted at the rear end of the chain stay 2e, a handle 5 for changing the direction of the front wheel 3, and a saddle 6; A crank 7 and a pedal 8 to which a human driving force consisting of pedaling force is applied, an electric motor 21 (see FIG. 4) as a driving source for generating an auxiliary driving force (assisting force), and various electrics including this motor 21 A battery drive comprising a motor drive unit 20 provided with a control unit 24 (see FIG. 4) for performing control and the like, and a secondary battery for supplying driving power to the motor 21. 12 and a handle 5 or the like, attached so as to integrally rotate coaxially with the hand operation portion (not shown) which can be operated by a passenger or the like and the crankshaft 7a, with manual drive force and assistance A drive sprocket (also referred to as front sprocket, crank sprocket or front gear) 13 as a drive power output wheel body that outputs a resultant force combined with a drive force, and a hub (also referred to as rear hub) 9 of rear wheel 4 A rear sprocket (also sometimes referred to as rear gear) 14 as a rear wheel body, and a chain as an endless drive power transmission body that is endlessly wound in a rotatable state over the drive sprocket 13 and the rear sprocket 14 And a chain cover 17 that covers the side of the chain 15 and the like from the side. The battery 12 is an example of a storage battery and is preferably a secondary battery, but another example of the storage battery may be a capacitor or the like. The crank 7 is composed of a crank arm 7b provided respectively on the left and right and a crankshaft 7a connecting the left and right crank arms 7b.

  As shown in FIGS. 1 and 2, also in this electrically assisted bicycle 1, the motor drive unit 20 is at an intermediate position between the front wheel 3 and the rear wheel 4 (more specifically, the intermediate position), such as substantially behind the crankshaft 7a. At the bottom of the And since it arrange | positions motor drive unit 20 with comparatively large weight in the center of the power-assisted bicycle 1 by setting it as such an arrangement composition, it is easy to lift the front wheel 3 or the rear wheel 4, Even if there is a level difference, the vehicle body (frame 2 etc.) of the electrically assisted bicycle 1 can be easily got over, and the running stability also becomes good.

  FIG. 3 is a side view of the motor drive unit 20 (the drive sprocket 13 is omitted), and FIG. 4 is a plan cross-sectional view of the motor drive unit 20. As shown in FIGS. 3 and 4, the motor drive unit 20 includes a unit case 22 including a motor case 22a, a left case 22b, and a right case 22c. The shaft 7a penetrates left and right. Further, a substantially cylindrical human power transmission body 28 to which a human power driving force from the crankshaft 7 a is transmitted to the outer periphery of the crankshaft 7 a, and an intermediate cylindrical body 23 to which the human power driving power from the human power transmission body 28 is transmitted; The manual driving force from the intermediate cylinder 23 is transmitted through the one-way clutch (one-way clutch for cutting off the auxiliary driving force) 30, and the manual driving force and the motor 21 transmitted through the manual transmission body 28 etc. The interlocking body 29 which functions as a combined body which combines the auxiliary driving force of the above is disposed. Furthermore, a speed reducing mechanism 25 having a speed reducing gear 36 and the like is disposed at the center of the unit case 22 in the front-rear direction, and a motor 21 is disposed at the rear left side in the unit case 22. A control printed circuit 24a provided with electronic components for performing various types of electrical control, a control unit 24 having a storage unit of various information, and the like are disposed.

  Specifically, as shown in FIGS. 4 and 5, the crankshaft 7a is rotatably disposed by the bearings 26 and 27 in a state in which the front portion of the motor drive unit 20 penetrates left and right, and the left side of the crankshaft 7a The tubular human-power transmission body 28 is fitted on the outer periphery of the inclining portion via the serration portion (or spline portion) 7 c so as to rotate integrally. A serration portion (or spline portion) 28b is also formed at a position corresponding to the serration portion (or spline portion) 7c of the crankshaft 7a in the inner periphery of the human power transmission body 28, and the serration portion (or spline portion) of the crankshaft 7a ) 7c is engaged.

  A magnetostriction generating portion 31b to which magnetic anisotropy is imparted is formed on the outer peripheral surface of the human power transmitting body 28, and a coil 31a is disposed on the outer periphery via a fixed gap (space). A magnetostrictive torque sensor (human power detection unit) 31 is configured by the generation unit 31 b and the coil 31 a. Thus, the human drive force from the crankshaft 7a is transmitted to the human power transmitter 28, and the torque sensor 31 detects the human drive force. Further, in the magnetostrictive torque sensor 31, the magnetostriction generating portion 31b is formed in a spiral shape that forms, for example, +45 degrees and -45 degrees with respect to the axial center direction of the human power transmission body 28, and the human power transmission body 28 When a manual drive force is transmitted to the surface, distortion occurs in the magnetostrictive portion 31b on the surface of the human power transmission body 28 to generate an increase and a decrease in permeability, so by measuring the inductance difference of the coil 31a. It is configured to be able to detect the magnitude of torque (human driving force). In this embodiment, with the above configuration, it is also possible to detect that the crankshaft 7a has been rotated in the opposite direction, but the present invention is not limited to this.

  The intermediate cylindrical body 23 is disposed at a position adjacent to the right side of the human power transmission body 28 on the outer periphery of the crank shaft 7a and is rotatably disposed with respect to the crankshaft 7a. A serration portion (or spline portion) 28 a formed on the outer periphery and a serration portion (or spline portion) 23 a formed on the inner periphery of the left end portion of the intermediate cylindrical body 23 are fitted. In this embodiment, a serration portion (or spline portion) 23a formed on the inner periphery of the left end portion of the intermediate cylindrical body 23 is fitted to the serration portion (or spline portion) 28a of the human power transmission body 28 from the outside There is.

  Further, as described above, the one-way clutch (one-way clutch for cutting off the auxiliary driving force) 30 is disposed between the intermediate cylinder 23 and the interlocking body 29, and the middle one is disposed inside the one-way clutch 30. The cylindrical body 23 is attached, and the interlocking body 29 is attached to the outside of the one-way clutch 30. The interlocking body 29 is disposed on the outer periphery of the crankshaft 7a so as to be rotatable with respect to the crankshaft 7a, and the auxiliary driving force from the motor 21 is transmitted. On the other hand, in the one-way clutch 30, the manual drive force in the forward direction from the intermediate cylinder 23 is transmitted to the interlocking body 29, while the auxiliary driving force in the forward direction from the interlocking body 29 is via the intermediate cylinder 23. It is configured not to be transmitted to the crankshaft 7a or the pedal 8 side. That is, even in this electrically assisted bicycle 1, so-called delay control is performed so that the motor 21 continues to rotate for a while even if the rider stops pedaling, but assistance is provided by the one-way clutch 30. The driving force is cut off to prevent the crankshaft 7a and the pedal 8 from rotating freely.

  Furthermore, as shown in FIGS. 5 and 6, the motor drive unit 20 detects the rotation of the intermediate cylindrical body 23, which is a member that rotates integrally with the crankshaft 7a, and thus the crankshaft 7a and the pedal 8. Two rotation detectors 10 (10A, 10B) are provided. In this embodiment, two light sensors, which are a pair consisting of the emitting unit 10a and the light receiving unit 10b, are arranged in the lateral direction (more specifically, the rotation direction of the tooth portion 11b of the rotating body 11 described later) Detector 10 (10A, 10B) is constituted (refer to Drawing 6-Drawing 8). Further, on the outer periphery of the left end portion of the intermediate cylindrical body 23, a rotating body 11 for blocking or transmitting the light of the rotation detector 10 (10A, 10B) is attached. The rotating body 11 has a substantially cylindrical attachment portion 11a attached and fixed to the outer periphery of the left end portion of the intermediate cylinder 23, and a tooth portion extending in the outer peripheral direction in a comb (tebbed) tooth shape from the left end portion of the attachment portion 11a. And (light shielding portion) 11b. Then, the light emitting path between the light emitting portion 10a and the light receiving portion 10b of the rotation detector 10 (10A, 10B) is provided by the tooth portion 11b and the tooth groove portion (light transmitting portion) 11c between these tooth portions 11b. By passing through, the rotation detector 10 is configured to detect the number of rotations (rotation amount) of the intermediate cylindrical body 23, and in turn, the crankshaft 7a and the pedal 8. Further, as shown in FIGS. 7 and 8 (in terms of arrangement in the drawing, they are shown in the opposite arrangement state to FIG. 6), the two rotation detectors 10A and 10B are each at a position where the phase of the output signal differs by 90 degrees. Since the input signal is different depending on the rotation direction of the rotation detectors 10A and 10B, the intermediate cylinder 23, and further, the forward and reverse directions of the crankshaft 7a and the pedal 8 are arranged based on the input signal. It can detect also about each rotation direction of. As shown in FIGS. 4 and 5, in this embodiment, the rotation detector 10 is provided with the rotating body 11 via the support member 18 extending rearward from the inside of the front end portion of the unit case 22. It is attached to the point.

  Further, a large diameter gear portion 29b for inputting the auxiliary driving force from the motor 21 is integrally formed on the outer periphery of the interlocking body 29 at the left side, and the driving force output wheel body is on the outer periphery of the right end of the interlocking body 29. As the drive sprocket 13 is inserted, the interlocking body 29 and the drive sprocket 13 rotate integrally. The crankshaft 7 a is rotatably supported via the interlocking body 29 by a bearing 27 externally fitted to the interlocking body 29. A thin-walled bearing or the like is provided between the interlocking body 29 and the crankshaft 7a, between the intermediate cylindrical body 23 and the crankshaft 7a, and between the right inner peripheral surface of the human power transmitter 28 and the crankshaft 7a. May be arranged.

  As shown in FIG. 4, the motor 21 is rotatably supported at its rotary shaft 21a and rotor portion 21b by bearings 32,33. Further, the rotary shaft 21a of the motor 21 is protruded rightward, and a tooth portion 21c is formed on the outer periphery of this protruding portion. The reduction mechanism 25 is configured to amplify rotational torque (auxiliary driving force) of the motor 21 through the reduction gear 36 and transmit the amplified torque to the large diameter gear portion 29 b of the interlocking body 29. Here, the support shaft for reduction gear 36 (reduction gear support shaft) is an example of a reduction gear small diameter support shaft portion (rotation reduction gear support shaft) rotatably supported by bearings 34 and 35. , A small diameter support shaft portion 36a and a reduction gear large diameter support shaft portion having a diameter larger than this (this is another example of a reduction gear support shaft, hereinafter simply referred to as a large diameter support shaft portion) It is integrally formed with 36b. Further, on the outer periphery of the small diameter support shaft portion 36a, a small diameter reduction gear portion (which is an example of a reduction gear portion separately from the small diameter support shaft portion 36a, hereinafter simply referred to as a small diameter gear portion) 36c It is assembled so that it may rotate integrally via a serration part (or spline part) etc. The small diameter gear portion 36 c is engaged with the large diameter gear portion 29 b of the interlocking body 29. On the other hand, on the outer periphery of the large diameter support shaft portion 36b of the reduction gear 36, a large diameter reduction gear portion (another example of the reduction gear portion, hereinafter simply referred to as the large diameter gear portion) 36d is disposed While the large diameter gear portion 36 d is engaged with the tooth portion 21 c of the rotation shaft 21 a of the motor 21, between the large diameter support shaft portion 36 b and the large diameter gear portion 36 d in the reduction gear 36 A one-way clutch 37 for manual drive force cutting is provided for not transmitting the rotational drive force from the interlocking body 29 to the motor 21 side.

  In the one-way clutch 37, an inner peripheral portion of the large diameter gear portion 36d of the reduction gear 36 based on the motor output (auxiliary driving force) is opposed such that a certain amount of auxiliary driving force is output during traveling. In the case where the drive sprocket 13 is relatively rotated forward with respect to the outer peripheral portion of the large diameter support shaft portion 36b (ie, the number of rotations of the inner periphery of the large diameter gear portion 36d of the reduction gear 36 in the forward direction) However, when the rotation speed of the outer periphery of the large diameter support shaft portion 36b opposed thereto is larger than the rotational speed in the forward direction), the auxiliary driving force transmitted to the large diameter gear portion 36d of the reduction gear 36 is It operates to transmit to the diameter support shaft 36b. Then, the auxiliary driving force is transmitted to the large diameter gear portion 29 b of the interlocking body 29 via the small diameter support shaft portion 36 a and the small diameter tooth portion 36 c. As a result, in the interlocking body 29, the manual drive force and the auxiliary drive force are combined, and the combined force of these is generated from the drive sprocket 13 as a drive output wheel body to the rear wheel 4 via the chain 15. It is transmitted.

  On the other hand, when the remaining capacity of the battery 12 disappears and the auxiliary driving force is not output from the motor 21, the large diameter gear portion 36d of the reduction gear 36 based on the motor output (auxiliary driving force) When the inner circumferential portion rotates in the direction opposite to the direction in which the drive sprocket 13 is advanced relatively to the outer circumferential portion of the large diameter support shaft portion 36b opposed thereto (the large diameter gear portion of the reduction gear 36 In the case where the number of revolutions in the forward direction of the inner periphery of 36d is smaller than the number of revolutions in the forward direction of the outer periphery of the large diameter support shaft portion 36b opposed thereto, the large diameter gear portion 36d of the reduction gear 36 The one-way clutch 37 disconnects the auxiliary driving force that has been transmitted to the large-diameter support shaft portion 36b.

  As a result, the remaining capacity of the battery 12 disappears, and when the pedal 8 is turned over in a state where the auxiliary driving force is not output from the motor 21 or the like, the small diameter gear portion 36c and the small diameter support shaft portion 36a or the large diameter Although the support shaft portion 36b is rotated, the large diameter gear portion 36d and the rotation shaft 21a and the rotor portion 21b of the motor 21 are not rotated.

  In the above configuration, when the pedal 8 is depressed during forward traveling, the manual driving force based on the pedaling force applied to the pedal 8 is transmitted from the crankshaft 7a to the manual transmission body 28, the intermediate cylindrical body 23, and the interlocking body 29. The driving force is detected by a torque sensor 31 provided on the human power transmitter 28. Then, the auxiliary driving force corresponding to the manual driving force is transmitted to the interlocking body 29 via the reduction gear 36 of the reduction mechanism 25 and the like, and the resultant force combined by the interlocking body 29 makes the chain 15 from the drive sprocket 13 It is transmitted to the rear wheel 4 via As a result, by adding the auxiliary driving force (assisting force) of the motor 21 corresponding to the manual driving force, it is possible to travel easily even on an uphill or the like.

  On the other hand, when the rider stops pedaling the pedal 8 while traveling, the rotation of the crankshaft 7a and the intermediate cylinder 23 is also stopped accordingly, so that the stopped state is detected by the rotation detector 10, and the motor 21 is stopped. Is stopped or braked. As described above, since the motor 21 is immediately stopped or braked when the rider stops pedaling the pedal 8 while traveling, the motor 21 is wastefully driven, and the consumption of the battery 12 can be suppressed.

  Further, according to the above configuration, by using an optical sensor as the rotation detector 10 (10A, 10B), the rotation of the intermediate cylindrical body 23 can be detected easily and reliably without exerting the influence of magnetism on the torque sensor 31. can do. That is, when a magnetic sensor is separately provided as the rotation detector 10 and a magnet is embedded in a part of the intermediate cylinder or a magnetic sensor having a magnet is used, the magnetic field generated by the magnetostriction generating portion 31 b The noise at the time of torque detection, such as fluctuation of, may occur, and the detection capability of torque may be reduced. On the other hand, since the optical sensor is used as the rotation detector 10, the rotation of the intermediate cylinder 23 can be detected easily and reliably in a state where the torque detection capability is well maintained. In addition, by using an optical sensor as the rotation detector 10, the rotation can be detected easily and reliably and at the same time the control is easy, so that the rotation can be detected quickly, and the rotation of the pedal 8 and the crankshaft 7a is stopped or reversely rotated. There is also an advantage that the motor 21 can be stopped quickly by detecting the

  Further, in the above configuration, the rotating body 11 is attached to the outer periphery of the intermediate cylindrical body 23. With this configuration, since the intermediate cylindrical body 23 is disposed on the outer periphery of the crankshaft 7a, the rotating body 11 should be disposed at a portion with a larger diameter than in the case where the rotating body 11 is provided on the crankshaft 7a. Therefore, even when the rotating body 11 having the same dimension in the radial direction is assembled, more teeth 11b can be formed in the rotating body 11, and the rotation detector 10 can detect without any trouble, and the rotation can be performed. The resolution of the detector 10 can be improved.

  When the rotation detector 10 composed of an optical sensor is attached to the crankshaft 7a to obtain the same resolution of the rotation detector 10, a disk or the like having a toothed portion is formed from the inner diameter portion to the outer diameter portion. Although it is conceivable to increase the dimension in the radial direction, in this case, there is a possibility that the disk or the cylinder in which the teeth are formed may be easily deformed. On the other hand, as described above, by attaching the rotating body 11 to the intermediate cylindrical body 23 disposed on the outer periphery of the crankshaft 7a, the radial direction from the inner diameter portion to the outer diameter portion of the rotating body 11 It is not necessary to increase the size too much, and the possibility of deformation of the teeth 11 b of the rotating body 11 can be minimized.

  Further, instead of attaching the rotating body 11 to the intermediate cylindrical body 23, as shown in FIG. 9, it may be attached to a human power transmitting body 28 disposed on the outer periphery of the crankshaft 7a. According to this configuration, the diameter of the mounting portion of the rotating body 11 is slightly smaller than that of the intermediate cylindrical body 23, so the resolution may be slightly reduced, but the human power transmitting body 28 also rotates integrally with the crankshaft 7a. As a result, the rotation of the human power transmitter 28, and hence the crank shaft 7a and the pedal 8 can be detected well. When the rotating body 11 is attached to the intermediate cylindrical body 23, the intermediate cylindrical body 23 is easily affected by the vibration from the one-way clutch 30 for cutting off the auxiliary driving force, etc. In the case of being attached to 28, there is an advantage of being less susceptible to the influence of vibration from the one-way clutch 30 or the like.

  Also, as a method of attaching the rotating body 11 to the human power transmitting body 28, there are bonding and press-fitting methods, but when the rotating body 11 is press-fit to the human power transmitting body 28 and assembled, There is a possibility that the resulting distortion may adversely affect the torque sensor 31. On the other hand, when the rotating body 11 is attached to the intermediate cylindrical body 23, such a problem does not occur, so the rotating body 11 can be easily and reliably applied to the intermediate cylindrical body 23 and to the torque sensor 31. It can be attached and fixed without adverse effects.

  In the above embodiment, the rotary body 11 having the teeth 11b for blocking light is provided, and the light passing through the tooth groove 11c between the teeth 11b is detected. For example, the rotational position and the number of rotations may be detected by providing a similar rotating body and providing a light receiving unit at a position where light is reflected, and inputting the reflected light.

  Further, in the above configuration, the rotation detector 10 for detecting the rotation of the interlocking body 29, the manual transmission body 28 and the crankshaft 7a is provided, and the interlocking body 29, the manual transmission body 28 and the crankshaft 7a are positive by the control unit 24. When it is detected that the vehicle is rotating in the direction (the direction in which the motor-assisted bicycle 1 moves forward), the vehicle travels temporarily with no force, or the pedal 8 becomes the top dead center or the bottom dead center position. Even in the case where the torque fluctuates due to a temporary weakening of the pedaling force, control may be performed to suppress the fluctuation of the auxiliary driving force. According to this configuration, it is possible to suppress the fluctuation of the auxiliary driving force when traveling and to improve the ride comfort.

  Further, in the above configuration, the small diameter gear portion 36c and the large diameter gear portion 36d as a plurality of reduction gear portions, the small diameter gear portion 36c and the small diameter gear portion 36c and The reduction gear 36 of the reduction mechanism 25 having a small diameter support shaft 36a and a large diameter support shaft 36b as a reduction gear support shaft for supporting the large diameter gear 36d is disposed. And, in this embodiment, a one-way clutch for manual drive force cutting which does not transmit the manual drive force from the interlocking body 29 side to the motor 21 side between the large diameter gear portion 36d and the large diameter support shaft portion 36b. 37 are provided.

  As a result, the remaining capacity of the battery 12 disappears, and when the pedal 8 is turned over in a state where the auxiliary driving force is not output from the motor 21 or the like, the small diameter gear portion 36c and the small diameter support shaft portion 36a or the large diameter Although the support shaft portion 36b is rotated, the large diameter gear portion 36d and the rotation shaft 21a and the rotor portion 21b of the motor 21 are not rotated, and it is not necessary to apply an extra force to the pedal 8 (the so-called drag resistance is extremely reduced be able to).

  Further, in the present embodiment, as shown in FIG. 3, the motor 21 and the control unit 24 are disposed so as to substantially overlap in a side view. Thereby, the area (projected area in the lateral direction) of the motor drive unit 20 in a side view is output from the one drive shaft and the auxiliary drive force from the drive sprocket 13 in this embodiment. Thus, there is an advantage that the motor drive unit 20 can be made smaller (made compact) as a so-called single-axis motor drive unit 20. The motor 21 and the control unit 24 are disposed on the opposite side in the width direction in a front view or a plan view of the motor drive unit 20 (the motor 21 is disposed on the left side, and the control unit 24 is disposed on the right side). ). As a result, the control unit 24 is unlikely to be affected by the heat of the motor 21 and good reliability can be maintained.

  In the above embodiment, the case where the one-way clutch 37 for manual drive force cutting is disposed between the large diameter gear portion 36d and the large diameter support shaft portion 36b has been described. A one-way clutch 37 for cutting off the driving force may be disposed between the small diameter gear portion 36c and the small diameter support shaft portion 36a.

  In the above embodiment, the case has been described in which the electrically assisted bicycle 1 is provided with a so-called single-axis motor drive unit 20 that outputs the manual drive force and the auxiliary drive force from one shaft. It is not limited. In the electrically assisted bicycle 40 shown in FIG. 10, as shown in FIG. 11 to FIG. 13, separately from the drive sprocket 13 as a manual drive force output wheel body disposed at one end of the crankshaft 7a, A motor drive unit 50, also referred to as a so-called two-shaft type, is provided with an auxiliary driving force output sprocket 51 as an auxiliary driving force output wheel body for outputting an auxiliary driving force. The motor drive unit 50 is provided with a rotation detector 10 including an optical sensor for detecting the rotation of the intermediate cylinder 23 or the human power transmitter 28 that rotates integrally with the crankshaft 7 a.

  As shown in FIGS. 11 and 12, in this embodiment, the auxiliary driving force from the motor 21 is output from the auxiliary driving force output sprocket 51 via the reduction mechanism 25 and the auxiliary driving force is an endless driving force. It is synthesized by a chain 15 as a transmission body and transmitted to the rear wheel 4. Then, as shown in FIGS. 12 and 13, as in the above embodiment, the rotating body 11 is attached to the intermediate cylindrical body 23 or the human power transmitting body 28, and the intermediate cylindrical body is formed by the rotation detector 10 formed of an optical sensor. The rotation of the crankshaft 23 or the pedal 8 is detected. Also according to this embodiment, it is possible to obtain the same effect as that of the above embodiment.

  The present invention is applicable to various types of electrically assisted bicycles capable of traveling by adding an auxiliary driving force generated by a motor to a manual driving force by a pedaling force from a pedal.

Claims (14)

A motor drive unit used for an electrically assisted bicycle capable of traveling by adding an auxiliary driving force generated by a motor to a manual driving force by a pedaling force from a pedal,
A crankshaft that passes through a unit case that constitutes an outer shell of the motor drive unit;
A cylindrical human power transmitter disposed on the outer periphery of the crankshaft;
A reduction mechanism having a reduction gear supported on a rotation shaft substantially parallel to the crankshaft;
A motor having a rotation axis substantially parallel to the crankshaft, and a tooth portion meshing with the reduction gear being provided on the rotation axis;
A control unit having a control substrate for controlling the motor;
A connecting member for connecting the motor and the control substrate;
The unit case is divided by a dividing portion, a first space in which a rotor portion and a stator portion of the motor are disposed, and a second space in which the control substrate and the crankshaft are disposed. Have inside,
The control substrate is disposed in the second space so as to have a region overlapping with the stator portion when the rotary shaft of the motor is viewed in the axial direction, and the control substrate is interposed between the region and the stator portion Arranged to form a space that is part of the second space,
The connection member is disposed to pass through the space. 2. The motor drive unit according to claim 1, wherein an end of the control substrate on the opposite side to the crankshaft side in the control substrate is located in a direction away from the crankshaft with respect to a rotation shaft of the reduction gear. The motor drive unit according to claim 1, wherein the control substrate is disposed in the unit case such that a substrate surface extends in a direction intersecting the crankshaft. The motor drive unit according to any one of claims 1 to 3, wherein the reduction gear is located in the second space. A rotating body that rotates with the crankshaft;
The motor drive unit according to any one of claims 1 to 4, further comprising: a rotation detector that detects the number of rotations of the rotating body. The motor drive unit according to claim 5, wherein the rotation detector and the rotating body are disposed in the second space. The rotating body has a detected portion whose rotation is detected by the rotation detector,
The motor drive unit according to claim 5 or 6, wherein the detection target portion is disposed at a position overlapping with the reduction gear when viewed in a direction substantially orthogonal to the crankshaft direction. A torque sensor is provided on the outer periphery of the human power transmission body,
A magnetostrictive portion of the torque sensor is formed on the human power transmission body,
The motor drive unit according to any one of claims 1 to 7, wherein a coil is disposed on the outer periphery of the human power transmission member in which the magnetostrictive part is formed. The rotation shaft of the reduction gear is supported by a first bearing disposed on the side of the rotor portion in the axial direction, and a second bearing disposed on the opposite side of the rotor portion in the axial direction.
The motor drive unit according to any one of claims 1 to 8, wherein an inner diameter of the second bearing is smaller than an inner diameter of the first bearing. The motor drive unit according to any one of claims 1 to 9, wherein the connection member is connected to the motor at a position in a direction away from the crankshaft from a rotation shaft of the reduction gear. The motor drive unit according to any one of claims 1 to 10.
Front wheels disposed on the front side of the electrically assisted bicycle;
A rear wheel disposed on the rear side of the electrically assisted bicycle;
An electrically assisted bicycle comprising: a battery for supplying power to the motor drive unit. The electric power assisted bicycle according to claim 11, wherein an axial center of the reduction gear is disposed below an axial center of the crankshaft and an axial center of the motor in the vertical direction of the electrically assisted bicycle. The battery is disposed on the rotary shaft side of the motor with respect to the crankshaft in the front-rear direction of the electrically assisted bicycle, and is disposed above the motor drive unit in the vertical direction of the electrically assisted bicycle. The electrically assisted bicycle according to claim 11 or 12. The electrically assisted bicycle according to any one of claims 11 to 13, wherein the motor drive unit and the battery are disposed between the front wheel and the rear wheel.

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