DE102022131718A1 - CRANK ARM AND CRANK ARRANGEMENT FOR A MUSCLE POWERED VEHICLE - Google Patents

Abstract

A crank arm includes an arm body and a force sensor. The force sensor includes a first strain gauge, a second strain gauge, a third strain gauge, and a fourth strain gauge. The first strain gauge, the second strain gauge, the third strain gauge, and the fourth strain gauge are arranged to satisfy a first equation (1)θ1−θ2+θ3−θ4=−2(1+v)IpIL2L1θa.

Description

BACKGROUND

TECHNICAL AREA

The present invention relates to a crank arm and a crank assembly for a human-powered vehicle.

BACKGROUND INFORMATION

A human-powered vehicle includes a crank device that includes a crank arm. The crank arm includes a sensor configured to measure a force applied to the crank arm during pedaling. The position at which a pedal force is applied from the user's shoe to a pedal can affect the force measured by the sensor. It is desirable to improve the measurement accuracy of a force sensor.

SUMMARY OF THE INVENTION

in einem Fall zu erfüllen, in dem: θ1 einen ersten Winkel darstellt, der bei einer Betrachtung in der axialen Richtung zwischen der Längsachse und der ersten Messachse definiert ist; θ2 einen zweiten Winkel darstellt, der bei einer Betrachtung in der axialen Richtung zwischen der Längsachse und der zweiten Messachse definiert ist; θ3 einen dritten Winkel darstellt, der bei einer Betrachtung in der axialen Richtung zwischen der Längsachse und der dritten Messachse definiert ist; θ4 einen vierten Winkel darstellt, der bei einer Betrachtung in der axialen Richtung zwischen der Längsachse und der vierten Messachse definiert ist; v eine Poissonzahl eines Materials des Kurbelarms darstellt; Ip ein zweites polares Flächenmoment des Kurbelarms darstellt; I ein zweites Flächenmoment des Kurbelarms darstellt; L1 einen ersten Abstand darstellt, der von einer Mitte eines Referenzquerschnitts zu dem ersten Dehnungsmessstreifen in dem Referenzquerschnitt definiert ist, wobei der Referenzquerschnitt entlang einer ersten Referenzebene senkrecht zu der Längsachse genommen wird; L2 einen zweiten Abstand darstellt, der von der Mitte des Referenzquerschnitts zu dem ersten Dehnungsmessstreifen in einer Richtung senkrecht zu der ersten Lochmittenachse und der Längsachse definiert ist; und θa einen Neigungswinkel darstellt, der zwischen der Längsachse und einer zweiten Referenzebene senkrecht zu der ersten Lochmittenachse definiert ist.According to a first aspect of the present invention, a crank arm for a human-powered vehicle includes an arm body and a force sensor. The arm body has a crank axle mounting hole, a pedal axle mounting hole, and a longitudinal axis. The crank axle mounting hole has a first hole center axis defining an axial direction. The pedal axle mounting hole has a second hole center axis parallel to the first hole center axis. The longitudinal axis extends to pass through the first hole center axis and the second hole center axis. The force sensor includes a first strain gauge, a second strain gauge, a third strain gauge, and a fourth strain gauge. The first strain gauge is attached to the crank arm and has a first measuring axis. The first strain gauge is configured to produce a first output indicative of a first amount of deformation occurring along the first measuring axis. The second strain gauge is attached to the crank arm and has a second measuring axis. The second strain gauge is configured to produce a second output indicative of a second amount of deformation occurring along the second measurement axis. The third strain gauge is attached to the crank arm and has a third measurement axis. The third strain gauge is configured to produce a third output indicative of a third amount of deformation occurring along the third measurement axis. The fourth strain gauge is attached to the crank arm and has a fourth measurement axis. The fourth strain gauge is configured to produce a fourth output indicative of a fourth amount of deformation occurring along the fourth measurement axis. The first strain gauge is closer to the first hole center axis than the third strain gauge and the fourth strain gauge when viewed along the first hole center axis. The second strain gauge is closer to the first hole center axis than the third strain gauge and the fourth strain gauge when viewed along the first hole center axis. The first strain gauge, the second strain gauge, the third strain gauge and the fourth strain gauge are arranged to satisfy a first equation (1) $$\theta 1-\mathrm{<figure-callout\; id="2"\; label="\theta "\; filenames="DE102022131718A1\_0008.png,DE102022131718A1\_0012.png"\; state="\{\{state\}\}">\theta </figure-callout>}2+\theta 3-\mathrm{<figure-callout\; id="4"\; label="\theta "\; filenames="DE102022131718A1\_0008.png,DE102022131718A1\_0017.png"\; state="\{\{state\}\}">\theta </figure-callout>}4=-\frac{2}{\left(1+v\right)}\frac{Ip}{I}\frac{L2}{L1}\theta a$$

in a case where: θ1 represents a first angle defined between the longitudinal axis and the first measuring axis when viewed in the axial direction; θ2 represents a second angle defined between the longitudinal axis and the second measuring axis when viewed in the axial direction; θ3 represents a third angle defined between the longitudinal axis and the third measuring axis when viewed in the axial direction; θ4 represents a fourth angle defined between the longitudinal axis and the fourth measuring axis when viewed in the axial direction; v represents a Poisson's ratio of a material of the crank arm; Ip represents a second polar moment of area of the crank arm; I represents a second moment of area of the crank arm; L1 represents a first distance defined from a center of a reference cross-section to the first strain gauge in the reference cross-section, the reference cross-section being taken along a first reference plane perpendicular to the longitudinal axis; L2 represents a second distance defined from the center of the reference cross section to the first strain gauge in a direction perpendicular to the first hole center axis and the longitudinal axis; and θa represents an inclination angle defined between the longitudinal axis and a second reference plane perpendicular to the first hole center axis.

In the crank arm according to the first aspect, since the first strain gauge, the second strain gauge, the third strain gauge and the fourth strain gauge are arranged to satisfy the first equation (1), it is possible to reduce the influence of a position in which a pedaling force is applied from a user's shoe to a pedal on a deformation amount measured by the force sensor. Thus, it is possible possible to improve the measurement accuracy of the force sensor.

According to a second aspect of the present invention, the crank arm according to the first aspect is configured such that the longitudinal axis defines a first region and a second region when viewed in the axial direction, the longitudinal axis being provided between the first region and the second region when viewed in the axial direction. The first strain gauge and the third strain gauge are provided in the first region when viewed in the axial direction. The second strain gauge and the fourth strain gauge are provided in the second region when viewed in the axial direction.

With the crank arm according to the second aspect, it is possible to reliably improve the measurement accuracy of the force sensor.

According to a third aspect of the present invention, the crank arm according to the first or second aspect is configured such that, when viewed in the axial direction, a first longitudinal distance is defined between the first strain gauge and the axis of rotation in a first direction. The first direction is defined such that, when viewed in the axial direction, it is parallel to the longitudinal axis. A second longitudinal distance is defined between the second strain gauge and the axis of rotation in the first direction when viewed in the axial direction. The first longitudinal distance is equal to the second longitudinal distance.

With the crank arm according to the third aspect, it is possible to reliably improve the measurement accuracy of the force sensor.

According to a fourth aspect of the present invention, the crank arm according to the third aspect is configured such that, when viewed in the axial direction, a third longitudinal distance is defined between the third strain gauge and the first hole center axis in the first direction. A fourth longitudinal distance is defined between the fourth strain gauge and the first hole center axis in the first direction when viewed in the axial direction. The third longitudinal distance is equal to the fourth longitudinal distance.

With the crank arm according to the fourth aspect, the measuring accuracy of the force sensor can be improved even more reliably.

According to a fifth aspect of the present invention, the crank arm according to any one of the first to fourth aspects is configured such that a first perpendicular distance is defined between the first strain gauge and the longitudinal axis in a second direction when viewed in the axial direction. The second direction is perpendicular to the longitudinal axis when viewed in the axial direction. A second perpendicular distance is defined between the second strain gauge and the longitudinal axis in the second direction when viewed in the axial direction. The first perpendicular distance is equal to the second perpendicular distance.

With the crank arm according to the fifth aspect, it is possible to reliably improve the measurement accuracy of the force sensor.

According to a sixth aspect of the present invention, the crank arm according to the fifth aspect is configured such that a third vertical distance is defined between the third strain gauge and the longitudinal axis in the second direction when viewed in the axial direction. A fourth vertical distance is defined between the fourth strain gauge and the longitudinal axis in the second direction when viewed along the axis of rotation. The third vertical distance is equal to the fourth vertical distance.

With the crank arm according to the sixth aspect, it is possible to improve the measurement accuracy of the force sensor even more reliably.

According to a seventh aspect of the present invention, the crank arm according to any one of the first to sixth aspects is configured such that a calculation result of the first equation (1) ranges from 3 degrees to 5 degrees.

With the crank arm according to the seventh aspect, it is possible to reliably improve the measurement accuracy of the force sensor.

According to an eighth aspect of the present invention, the crank arm according to any one of the first to seventh aspects is configured such that the crank arm is free from a strain gauge other than the first strain gauge, the second strain gauge, the third strain gauge and the fourth strain gauge.

With the crank arm according to the eighth aspect, it is possible to simplify the structure of the force sensor and reduce the manufacturing cost of the crank arm.

According to a ninth aspect of the present invention, the crank arm according to any one of the first to eighth aspects further comprises a first Arm end and a second arm end. The arm body extends between the first arm end and the second arm end along the longitudinal axis. The crank axle mounting hole is provided at the first arm end. The pedal axle mounting hole is provided at the second arm end. The first arm end has a first thickness defined along the first hole center axis and having a first axial center. The second arm end has a second thickness defined along the second hole center axis and having a second axial center. The longitudinal axis is defined to pass through the first axial center and the second axial center.

With the crank arm according to the ninth aspect, it is possible to reliably improve the measurement accuracy of the force sensor.

According to a tenth aspect of the present invention, the crank arm according to any one of the first to ninth aspects is configured such that the arm body includes a mounting surface. The first strain gauge, the second strain gauge, the third strain gauge, and the fourth strain gauge are provided on the mounting surface. The longitudinal axis extends along the mounting surface.

With the crank arm according to the tenth aspect, it is possible to reliably improve the measurement accuracy of the force sensor.

in einem Fall zu berechnen, in dem: E den Verformungsbetrag des Kurbelarms darstellt; E1 die erste Ausgabe darstellt; E2 die zweite Ausgabe darstellt; E3 die dritte Ausgabe darstellt; und E4 die vierte Ausgabe darstellt.According to an eleventh aspect of the present invention, the crank arm according to any one of the first to tenth aspects further comprises an electronic controller electrically connected to the first strain gauge, the second strain gauge, the third strain gauge and the fourth strain gauge. The electronic controller is configured to calculate a deformation amount of the crank arm based on the first output, the second output, the third output, the fourth output and a second equation (2). $$E=E1-\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="DE102022131718A1\_0008.png,DE102022131718A1\_0012.png"\; state="\{\{state\}\}">E</figure-callout>}2+E3-\mathrm{<figure-callout\; id="4"\; label="E"\; filenames="DE102022131718A1\_0008.png,DE102022131718A1\_0017.png"\; state="\{\{state\}\}">E</figure-callout>}4$$

in a case where: E represents the deformation amount of the crank arm; E1 represents the first output; E2 represents the second output; E3 represents the third output; and E4 represents the fourth output.

With the crank arm according to the eleventh aspect, it is possible to reliably improve the measurement accuracy of the force sensor.

According to a twelfth aspect of the present invention, a crank assembly comprises the crank arm according to any one of the first to eleventh aspects and a crank axle.

With the crank assembly according to the twelfth aspect, it is possible to reduce the influence of the position where the pedaling force is applied from the user's shoe to the pedal on the amount of deformation measured by the force sensor. Thus, it is possible to improve the measurement accuracy of the force sensor in the crank assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

• 1 ist eine perspektivische Ansicht einer Kurbelanordnung eines muskelkraftbetriebenen Fahrzeugs nach einer ersten Ausführungsform.
• 2 ist eine Seitenrissansicht der in 1 dargestellten Kurbelanordnung.
• 3 ist eine Seitenrissansicht eines Kurbelarms der in 1 dargestellten Kurbelanordnung.
• 4 ist eine Seitenrissansicht des Kurbelarms der in 1 dargestellten Kurbelanordnung.
• 5 ist ein schematisches Blockdiagramm der in 1 dargestellten Kurbelanordnung.
• 6 ist eine Seitenrissansicht des Kurbelarms der in 1 dargestellten Kurbelanordnung, wobei ein Gehäuse weggelassen wurde.
• 7 ist eine Draufsicht auf einen Kraftsensor des Kurbelarms der in 1 dargestellten Kurbelanordnung.
• 8 ist eine schematische Querschnittsansicht des Kurbelarms entlang der Linie VIII-VIII von 4.
• 9 ist ein schematisches Blockdiagramm einer Kurbelanordnung nach einer Modifikation.
• 10 ist eine perspektivische Ansicht einer Kurbelanordnung nach einer zweiten Ausführungsform.
• 11 ist ein schematisches Blockdiagramm der in 10 dargestellten Kurbelanordnung.
• 12 ist eine perspektivische Ansicht einer Kurbelanordnung nach einer Modifikation.
• 13 ist eine perspektivische Ansicht einer Kurbelanordnung nach einer dritten Ausführungsform.
• 14 ist ein schematisches Blockdiagramm der in 13 dargestellten Kurbelanordnung.
• 15 ist eine weitere perspektivische Ansicht der in 13 dargestellten Kurbelanordnung.

A more complete understanding of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

• 1 is a perspective view of a crank assembly of a human-powered vehicle according to a first embodiment.
• 2 is a side elevation view of the 1 crank arrangement shown.
• 3 is a side elevation view of a crank arm of the 1 crank arrangement shown.
• 4 is a side elevation view of the crank arm of the 1 crank arrangement shown.
• 5 is a schematic block diagram of the 1 crank arrangement shown.
• 6 is a side elevation view of the crank arm of the 1 crank arrangement shown, with one housing omitted.
• 7 is a top view of a force sensor of the crank arm of the 1 crank arrangement shown.
• 8th is a schematic cross-sectional view of the crank arm along the line VIII-VIII of 4 .
• 9 is a schematic block diagram of a crank assembly after a modification.
• 10 is a perspective view of a crank assembly according to a second embodiment.
• 11 is a schematic block diagram of the 10 crank arrangement shown.
• 12 is a perspective view of a crank assembly after a modification.
• 13 is a perspective view of a crank assembly according to a third embodiment.
• 14 is a schematic block diagram of the 13 crank arrangement shown.
• 15 is another perspective view of the 13 crank arrangement shown.

DESCRIPTION OF THE EMBODIMENTS

The embodiments will now be described with reference to the accompanying drawings, in which like reference numerals designate corresponding or identical elements in the various drawings.

First embodiment

As in 1 , a human-powered vehicle 2 includes a crank assembly 10 according to one of the embodiments. The crank assembly 10 is rotatable relative to a vehicle body 2A of the human-powered vehicle 2 about an axis of rotation A1. The crank assembly 10 is rotatable relative to the vehicle body 2A of the human-powered vehicle 2 about the axis of rotation A1 in a direction of rotation D1. The crank assembly 10 is rotatable relative to the vehicle body 2A of the human-powered vehicle 2 about the axis of rotation A1 in a drive direction of rotation D11 during pedaling. The direction of rotation D1 includes the drive direction of rotation D11 and a reverse direction of rotation D12. The reverse direction of rotation D12 is a direction opposite to the drive direction of rotation D11.

In the present application, the term “human-powered vehicle” includes a vehicle that moves with a propulsion force that includes at least the human power of a user who drives the human-powered vehicle (i.e., the driver). The human-powered vehicle includes various types of bicycles such as mountain bikes, racing bikes, city bikes, cargo bikes, hand bikes, and recumbent bicycles. In addition, the human-powered vehicle also includes an electric bicycle (e-bike). The electric bicycle is an electrically assisted bicycle that assists the propulsion of a vehicle with an electric motor. However, the total number of wheels of the human-powered vehicle is not limited to two. The human-powered vehicle can also be a vehicle with one wheel or three or more wheels, for example. In particular, the human-powered vehicle does not include a vehicle that uses only an internal combustion engine as a propulsion force. In general, a light road vehicle, i.e. a vehicle that does not require a driver's license for public road traffic, is considered a human-powered vehicle.

The crank assembly 10 includes a crank arm 14 and a crank axle 16. The crank assembly 10 includes a crank arm 18. The crank arm 14 is attached to the crank axle 16. The crank arm 18 is attached to the crank axle 16. The crank arm 14, the crank axle 16 and the crank arm 18 are rotatable relative to the vehicle body 2A of the human-powered vehicle 2 in the drive rotation direction D 11.

The crank assembly 10 further includes a sprocket 20. The crank assembly 10 further includes a sprocket 22. The sprocket 20 is configured to engage a chain 4. The sprocket 22 is configured to engage the chain 4. The sprocket 20 or 22 is configured to transmit a driving force via the chain 4 to another sprocket, for example a rear sprocket. The sprocket 20 is attached to one of the crank axle 16 and the crank arm 18. The sprocket 22 is attached to at least one of the crank axle 16, the crank arm 18, and the sprocket 20. The sprocket 22 may be omitted from the crank assembly 10 if needed and/or desired.

As in 2 , the crank axle 16 includes a first axle end 16A and a second axle end 16B. The crank axle 16 extends between the first axle end 16A and the second axle end 16B along the axis of rotation A1. The crank arm 14 is attached to the first axle end 16A. The crank arm 18 is attached to the second axle end 16B.

The crank arm 14 for the human power vehicle 2 includes an arm body 14A. The arm body 14A has a crank axle mounting hole 14B and a pedal axle mounting hole 14C. The crank axle mounting hole 14B has a first hole center axis CA11. The first hole center axis CA11 defines an axial direction D2. The pedal axle mounting hole 14C has a second hole center axis CA12. The second hole center axis CA12 is parallel to the first hole center axis CA11. The crank axle 16 is connected to the crank axle mounting hole 14B. The first hole center axis CA11 coincides with the rotation axis A1.

The crank arm 14 further includes a first arm end 14D and a second arm end 14E. The arm body 14A extends between the first arm end 14D and the second arm end 14E. The crank axle mounting hole 14B is provided at the first arm end 14D. The pedal axle mounting hole 14C is provided at the second arm end 14E.

The crank arm 18 for the muscle-powered vehicle 2 comprises an arm body 18A. The arm body 18A has a crank axle fastening hole 18B and a pedal axle mounting hole 18C. The crank axle mounting hole 18B has a first hole center axis CA21. The first hole center axis CA21 defines an axial direction D3. The pedal axle mounting hole 18C has a second hole center axis CA22. The second hole center axis CA22 is parallel to the first hole center axis CA21. The crank axle 16 is coupled to the crank axle mounting hole 18B. The first hole center axis CA21 coincides with the rotation axis A1 and the first hole center axis CA11.

The crank arm 18 further includes a first arm end 18D and a second arm end 18E. The arm body 18A extends between the first arm end 18D and the second arm end 18E. The crank axle mounting hole 18B is provided at the first arm end 18D. The pedal axle mounting hole 18C is provided at the second arm end 18E.

In the present embodiment, crank arm 14 is a left crank arm while crank arm 18 is a right crank arm. However, crank arm 14 may be a right crank arm if needed and/or desired. Crank arm 18 may be a left crank arm if needed and/or desired.

In the present application, the following directional terms "front", "rear", "forward", "backward", "left", "right", "across", "upward" and "downward" and all other similar directional terms refer to the directions determined based on a user (e.g., a driver) facing a handlebar or controller in the user's standard position (e.g., on a saddle or a seat) in the human-powered vehicle 2. Accordingly, these terms used to describe the crank assembly 10 or other components are to be interpreted with respect to the human-powered vehicle 2 equipped with the crank assembly 10 or other components as used in an upright driving position on a horizontal surface.

As in 2 As can be seen, the human-powered vehicle 2 includes a pedal 24. The pedal 24 includes a pedal axle 24A and a pedal body 24B. Namely, the crank assembly 10 for the human-powered vehicle 2 includes the pedal axle 24A and the pedal body 24B. The pedal body 24B is rotatably connected to the pedal axle 24A. The pedal axle 24A is adapted to be attached to the crank arm 14 of the crank assembly 10. The pedal axle 24A is threadably engaged with the pedal axle attachment hole 14C of the crank arm 14.

The pedal body 24B is coupled to the pedal axle 24A for rotation about a rotation axis A2. The pedal axle 24A extends along the rotation axis A2. The pedal body 24B includes a tread 24C on which a shoe of the user is to be placed. The pedal body 24B may have a binding structure to which a cleat of the shoe is to be fixedly coupled.

The human-powered vehicle 2 includes a pedal 26. The pedal 26 includes a pedal axle 26A and a pedal body 26B. The crank assembly 10 for the human-powered vehicle 2 includes the pedal axle 26A and the pedal body 26B. The pedal body 26B is rotatably coupled to the pedal axle 26A. The pedal axle 26A is configured to be attached to the crank arm 18 of the crank assembly 10. The pedal axle 26A is threadably engaged with the pedal axle attachment hole 18C of the crank arm 18.

The pedal body 26B is pivotally coupled to the pedal axle 26A about a pivot axis A3. The pedal axle 26A extends along the pivot axis A3. The pedal body 26B includes a tread 26C upon which a user's shoe is to be placed. The pedal body 26B may include a binding structure to which a cleat is to be fixedly coupled.

The crank assembly 10 includes an electrical device 27. The electrical device 27 is at least partially provided on at least one of the crank arm 14, the crank axle 16, the crank arm 18, and the sprocket 20 and/or 22. The electrical device 27 is at least partially provided on the crank arm 14. In the present embodiment, the electrical device 27 is entirely provided on the crank arm 14. The electrical device 27 is provided between the first arm end 14D and the second arm end 14E. The electrical device 27 is mounted on an outer surface of the crank arm 14. However, the electrical device 27 may be at least partially provided inside the crank arm 14 if needed and/or desired. The electrical device 27 may be at least partially provided on the crank axle 16, the crank arm 18, and the sprocket 20 and/or 22 if needed and/or desired.

As in 3 As can be seen, the arm body 14A has a longitudinal axis LA1. The longitudinal axis LA1 extends such that it passes through the first hole center axis CA11 and the second hole center axis CA12. The arm body 14A extends between the first arm end 14D and the second arm end 14E along the longitudinal axis LA1.

As in 4 As can be seen, the longitudinal axis LA1 intersects the first hole center axis CA11 and the second hole center axis CA12. The longitudinal axis LA1 is not perpendicular to the first hole center axis CA11 and the second hole center axis CA12. The longitudinal axis LA1 is inclined with respect to the first hole center axis CA11 and the second hole center axis CA12.

The arm body 14A includes a mounting surface 14S. The electric device 27 is provided on the mounting surface 14S. The mounting surface 14S has a flat shape. The longitudinal axis LA1 extends along the mounting surface 14S.

The first arm end 14D has a first thickness T1 defined along the first hole center axis CA11. The first hole center axis CA11 has a first axial center point CP1. The second arm end 14E has a second thickness T2 defined along the second hole center axis CA12. The second hole center axis CA12 has a second axial center point CP2. The longitudinal axis LA1 is defined to pass through the first axial center point CP1 and the second axial center point CP2.

The longitudinal axis LA1 is not parallel and not perpendicular to the first hole center axis CA11. The longitudinal axis LA1 is inclined relative to the first hole center axis CA11. The longitudinal axis LA1 is not parallel and not perpendicular to the second hole center axis CA12. The longitudinal axis LA1 is inclined with respect to the second hole center axis CA12. The longitudinal axis LA1 is not parallel and not perpendicular to the mounting surface 14S. The longitudinal axis LA1 is inclined with respect to the mounting surface 14S. However, the longitudinal axis LA1 can run perpendicular to the first hole center axis CA11 if required and/or desired. The longitudinal axis LA1 can run perpendicular to the second hole center axis CA12 if required and/or desired. The longitudinal axis LA1 can run parallel to the mounting surface 14S if required and/or desired.

As in 5 As can be seen, the electrical device 27 includes an electronic controller EC1. In the present embodiment, the crank arm 14 further includes the electronic controller EC1. However, the electronic controller EC1 may be provided on another part (e.g., the crank axle 16, the crank arm 18) of the crank assembly 10 if necessary and/or desired.

The electrical device 27 further comprises a radio communicator WC1. The radio communicator WC1 is configured to wirelessly communicate with an additional radio communicator WC2 of an additional electrical device 6. The radio communicator WC1 is configured to wirelessly transmit a force with respect to the crank assembly 10. The electronic controller EC1 is electrically connected to the radio communicator WC1. The electrical device 27 comprises a housing 28. The radio communicator WC1 and the electronic controller EC1 are provided in the housing 28. As shown in 1 As can be seen, the housing 28 is attached to the crank assembly 13. The housing 28 is attached to the crank arm 14.

As in 5 As can be seen, the electronic controller EC1 includes a processor 30P, a memory 30M, a circuit board 30C, and a bus 30D. The electrical device 27 for the human-powered vehicle 2 includes the circuit board 30C. The processor 30P is coupled to the memory 30M. The memory 30M is coupled to the processor 30P. The processor 30P and the memory 30M are electrically mounted on the circuit board 30C. The processor 30P is electrically connected to the memory 30M via the circuit board 30C and the bus 30D. The memory 30M is electrically connected to the processor 30P via the circuit board 30C and the bus 30D. The bus 30D is provided on the circuit board 30C. The electronic controller EC1 includes a semiconductor.

The processor 30P includes, for example, at least one of a central processing unit (CPU), a microprocessing unit (MPU), and a memory controller. The memory 30M is electrically connected to the processor 30P. The memory 30M includes, for example, at least one of a volatile memory and a non-volatile memory. Examples of the volatile memory include a random access memory (RAM) and a dynamic random access memory (DRAM). Examples of the non-volatile memory include a read only memory (ROM), an electrically erasable programmable ROM (EEPROM), and a hard disk drive (HDD). The memory 30M includes memory areas, each with an address. The processor 30P is configured to control the memory 30M, store data in the memory areas of the memory 30M, and read data from the memory areas of the memory 30M. The processor 30P may also be referred to as a hardware processor 30P. The memory 30M may also be referred to as a hardware memory 30M. The memory 30M may also be referred to as computer-readable storage medium 30M.

The electronic controller EC1 is programmed to execute at least one control algorithm of the electrical device 27. The memory 30M (e.g. the ROM) stores at least one program with at least one program instruction. The at least one program is read into the processor 30P, and thereby the at least one control algorithm of the electrical device 27 is executed based on the at least one program. The electronic controller EC1 may also be referred to as an electronic control circuit or electronic circuit EC1. The electronic controller EC1 may also be referred to as an electronic hardware controller EC1.

The structure of the electronic controller EC1 is not limited to the above structure. The structure of the electronic controller EC1 is not limited to the processor 30P, the memory 30M and the bus 30D. The electronic controller EC1 can be realized by pure hardware or a combination of hardware and software. The processor 30P and the memory 30M can be integrated as a chip such as an application-specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

As in 5 As can be seen, the radio communicator WC1 is electrically connected to the processor 30P and the memory 30M via the circuit board 30C and the bus 30D. The radio communicator WC1 is electrically mounted on the circuit board 30C. The radio communicator WC1 includes a signal transmission circuit or a signal transmission circuit, a signal reception circuit or a signal reception circuit, and an antenna. Therefore, the radio communicator WC1 may also be referred to as a radio communicator circuit or a radio communicator circuit WC1.

The radio communicator WC1 is configured to superimpose digital signals on carrier waves using a predetermined radio communication protocol to transmit signals wirelessly. Examples of the predetermined radio communication protocol are Wi-Fi (registered trademark), Zigbee (registered trademark), Bluetooth (registered trademark), ANT (registered trademark), and other radio communication protocols. In the present embodiment, the radio communicator WC1 is configured to encrypt signals using a cryptographic key to generate encrypted radio signals. The radio communicator WC1 is configured to transmit radio signals via the antenna. The radio communicator WC1 may be a one-way radio communication device such as a receiver or a two-way radio communication device such as a transceiver.

The radio communicator WC1 is configured to receive radio signals via the antenna. In the present embodiment, the radio communicator WC1 is configured to decrypt the radio signals to recognize the signals transmitted from other radio communicators. The radio communicator WC1 is configured to decrypt the radio signals using the cryptographic key.

As in 5 As can be seen, the crank arm 14 for the human-powered vehicle 2 comprises a force sensor 32. The force sensor 32 is arranged to determine rotational information(s) INF1. The rotational information(s) INF1 includes a force exerted on the crank assembly 10 in the rotational direction D1 (see eg 1 ). Therefore, the force sensor 32 is configured to measure the force exerted on the crank assembly 10. The force sensor 32 is configured to output a measurement value indicative of the force exerted on the crank assembly 10 in the rotational direction D1. In the present embodiment, the force sensor 32 is configured to measure the force exerted on the crank assembly 13. The force sensor 32 is configured to measure the force exerted on the crank arm 14. However, the force sensor 32 may be configured to measure the force exerted on another part of the crank assembly 10 if needed and/or desired. The force sensor 32 may be configured to measure the force exerted on another part (e.g., the crank axle 16, the crank arm 18) of the crank assembly 13 if needed and/or desired.

The electronic controller EC1 is configured to receive the rotation information(s) INF1 determined by the force sensor 32. The electronic controller EC1 is electrically connected to the force sensor 32. The electronic controller EC1 is electrically connected to the force sensor 32 to receive the rotation information(s) INF1 determined by the force sensor 32. The electronic controller EC1 is configured to receive the force measured by the force sensor 32. The electronic controller EC1 is electrically connected to the force sensor 32 to receive the force measured by the force sensor 32.

The force sensor 32 includes, for example, a sensor body 34 and a measuring circuit 36. The sensor body 34 is attached to the crank assembly 13. The sensor body 34 is attached to the crank arm 14. The sensor body 34 is configured to detect a change in the electrical resistance The sensor body 34 is configured to output the change in electrical resistance as a function of the degree of deformation of the crank assembly 10. The sensor body 34 is configured to output the change in electrical resistance as a function of the deformation of the crank arm 14. The measuring circuit 36 is electrically connected to the sensor body 34 to convert the output of the sensor body 34 into a voltage that indicates the degree of deformation of the crank assembly 10 (e.g. the crank arm 14). The measuring circuit 36 forms, for example, a bridge circuit with the force sensor 32.

As in 5 As can be seen, the measuring circuit 36 is electrically connected to the electronic controller EC1. The measuring circuit 36 is electrically mounted on the circuit board 30C of the electronic controller EC1. The measuring circuit 36 is electrically connected to the sensor body 34 via, for example, the circuit board 30C and an additional circuit board such as a flexible printed circuit. The electronic controller EC1 is electrically connected to the measuring circuit 36 to receive the deformation amount of the crank assembly 10 (e.g., the crank arm 14).

As in 5 As can be seen, the electrical device 27 further comprises a position detector 38. The position detector 38 is configured to determine the rotation information(s) INF1. The rotation information(s) INF1 contains/contains a rotation position of the crank assembly 10. Thus, the position detector 38 is configured to detect the rotation position of the crank assembly 10.

The electronic controller EC1 is configured to receive the rotation information(s) INF1 determined by the position detector 38. The electronic controller EC1 is electrically connected to the position detector 38 to receive the rotation information(s) INF1 determined by the position detector 38. The electronic controller EC1 is configured to receive the rotational position detected by the position detector 38. The electronic controller EC1 is electrically connected to the position detector 38 to receive the rotational position detected by the position detector 38.

In the present embodiment, the position detector 38 includes an acceleration sensor. The acceleration sensor is configured to detect an inclination angle of the crank arm 14 about the rotation axis A1 as the rotation position of the crank assembly 10. The inclination angle of the crank arm 14 indicates the rotation position of the crank assembly 10. Examples of the acceleration sensor include a two-axis acceleration sensor.

The electronic controller EC1 is electrically connected to the acceleration sensor to receive the inclination angle detected by the acceleration sensor of the position detector 38. The electronic controller EC1 is configured to calculate the rotational position of the crank assembly 10 based on the inclination angle detected by the acceleration sensor of the position detector 38. The position detector 38 may include other sensors, such as a gyroscopic sensor or a magnetic sensor (e.g., a magnetic body and a Hall sensor), instead of or in addition to the acceleration sensor, if necessary and/or desired.

The electronic controller EC1 is configured to count the number of revolutions of the crank assembly 10 per unit time based on the rotational position detected by the position detector 38. Namely, the electronic controller EC1 is configured to determine a rotational speed (e.g., a cadence) of the crank assembly 10 based on the rotational position detected by the position detector 38. However, the electrical device 27 may, if necessary and/or desired, include a cadence sensor that is a separate sensor from the position detector 38. In such embodiments, the cadence sensor includes a detection object and a detector. The detection object is mounted on a surface separated from the vehicle body 2A (see, e.g., FIG. 1). 1 ) and the crank assembly 10. The detector is provided on the other of the vehicle body 2A and the crank assembly 10. The detector is configured to detect the detection object.

As in 5 As can be seen, the electrical device 27 includes an electrical power source 42. The electrical power source 42 is electrically connected to the radio communicator WC1, the electronic controller EC1, the force sensor 32, and the position detector 38 to supply electricity to the radio communicator WC1, the electronic controller EC1, the force sensor 32, and the position detector 38. The electrical device 27 includes a voltage controller configured to control the electricity supplied by the power source 42. Examples of the electrical power source 42 include a battery (e.g., a primary battery, a secondary battery).

The electrical device 27 includes an electrical connection terminal 45 to which a cable connector of an electrical cable can be detachably connected. The electrical connection terminal 45 is electrically connected to the electronic controller EC1. In a case where the electrical power source 42 includes a secondary battery, the electrical power source 42 can be charged via the electrical connection terminal 45. In such embodiments, the electrical device 27 includes a voltage controller which is arranged to control the electricity supplied from a power source via the electrical connection port 45. The electronic controller EC1 can be arranged to communicate with another electrical device 27 via the electrical connection port 45 and an electrical cable in order to, for example, update the software when necessary and/or desired.

The electronic controller EC1 is configured to calculate the force based on the deformation amount of the crank assembly 10 (e.g. the crank arm 14) determined by the force sensor 32. The electronic controller EC1 is configured to calculate the force (e.g. the torque) exerted on the crank assembly 10 based on the deformation amount of the crank assembly 10 (e.g. the crank arm 14) determined by the force sensor 32. The rotation information(s) INF1 include(s) the power INF 11 applied to the crank assembly 10 and a rotational speed INF12 of the crank assembly 10. For example, the electronic controller EC1 is configured to calculate the power INF 11 exerted on the crank assembly 10 based on the torque exerted on the crank assembly 10 (e.g. the crank arm 14) and the rotational speed INF12 of the crank assembly 10. However, if necessary and/or desired, the electronic controller EC1 may be configured to calculate the power INF 11 applied to the crank assembly 10 based on other data. For example, the electronic controller EC1 may be configured to calculate an average of the power INF 11 during one revolution of the crank arm 14. For example, the electronic controller EC1 may be configured to calculate the total power during one revolution of the crank assembly 13 by doubling the power INF11 on the single crank arm.

The electronic controller EC1 is configured to control the radio communicator WC1 to wirelessly transmit the rotation information(s) INF1. The electronic controller EC1 is configured to control the radio communicator WC1 to wirelessly transmit the power INF11 calculated by the electronic controller EC1 based on the force detected by the force sensor 32. The electronic controller EC1 is configured to control the radio communicator WC1 to wirelessly transmit the rotation speed INF12 calculated by the electronic controller EC1.

The electrical device 27 is configured to communicate with the additional electrical device 6. The additional electrical device 6 is configured to receive the rotation information(s) INF1 (e.g., the power INF11, the rotation speed INF12) wirelessly from the electrical device 27. The additional electrical device 6 is configured to wirelessly transmit a signal SG to the electrical device 27 at predetermined intervals. The electrical device 27 is configured to recognize from the signal SG that the radio communication between the electrical device 27 and the additional electrical device 6 is normal. Examples of the additional electrical device 6 include a cyclocomputer, a smartphone, and a tablet computer.

The additional electrical device 6 includes the additional radio communicator WC2, an additional electronic controller EC2, a display 46 and a user interface 48. The additional electronic controller EC2 is electrically connected to the additional radio communicator WC2, the display 46 and the user interface 48 to control the additional radio communicator WC2, the display 46 and the user interface 48.

The additional radio communicator WC2 is configured to wirelessly receive the rotation information(s) INF1 from the radio communicator WC1. The additional electronic controller EC2 is electrically connected to the additional radio communicator WC2 to receive the rotation information(s) INF1 (e.g. the power INF11, the rotation speed INF12) wirelessly received from the additional radio communicator WC2.

As in 5 As can be seen, the additional electronic control EC2 includes a processor 50P, a memory 50M, a printed circuit board 50C and a bus 50D. The processor 50P is coupled to the memory 50M. The memory 50M is coupled to the processor 50P. The processor 50P and the memory 50M are electrically mounted on the printed circuit board 50C. The processor 50P is electrically connected to the memory 50M via the printed circuit board 50C and the bus 50D. The memory 50M is electrically connected to the processor 50P via the printed circuit board 50C and the bus 50D. The bus 50D is provided on the printed circuit board 50C. The additional electronic control EC2 includes a semiconductor.

The processor 50P includes, for example, at least one of a CPU, an MPU, and a memory controller. The memory 50M is electrically connected to the processor 50P. The memory 50M includes, for example, at least one of a volatile memory and a non-volatile memory. Examples of the volatile memory include a RAM and a DRAM. Examples of the non-volatile memory include a ROM, an EEPROM, and an HDD. The memory 50M contains memory areas, each with an address. The processor 50P is configured to control the memory 50M, store data in the memory areas of the memory 50M, and read data from the memory areas of the memory 50M. The processor 50P may also be referred to as the hardware processor 50P. The memory 50M may also be referred to as the hardware memory 50M. The memory 50M may also be referred to as the computer-readable storage medium 50M.

The additional electronic controller EC2 is programmed to execute at least one control algorithm of the additional electrical device 6. The memory 50M (e.g. the ROM) stores at least one program with at least one program instruction. The at least one program is read into the processor 50P, and thereby the at least one control algorithm of the additional electrical device 6 is executed based on the at least one program. The additional electronic controller EC2 may also be referred to as electronic control circuit or electronic control circuit EC2. The additional electronic controller EC2 may also be referred to as additional electronic hardware controller EC2.

The structure of the additional electronic controller EC2 is not limited to the above structure. The structure of the additional electronic controller EC2 is not limited to the processor 50P, the memory 50M, and the bus 50D. The additional electronic controller EC2 can be realized by pure hardware or a combination of hardware and software. The processor 50P and the memory 50M can be integrated as a chip such as an ASIC or an FPGA.

As in 5 As can be seen, the additional radio communicator WC2 is electrically connected to the processor 50P and the memory 50M via the circuit board 50C and the bus 50D. The additional radio communicator WC2 is electrically mounted on the circuit board 50C. The additional radio communicator WC2 includes a signal transmission circuit or a signal transmission circuit, a signal reception circuit or a signal reception circuit, and an antenna. Therefore, the additional radio communicator WC2 may also be referred to as a radio communicator circuit or a radio communicator circuit WC2.

The additional radio communicator WC2 is configured to superimpose digital signals on carrier waves using a predetermined radio communication protocol to transmit signals wirelessly. Examples of the predetermined radio communication protocol are Wi-Fi (registered trademark), Zigbee (registered trademark), Bluetooth (registered trademark), ANT (registered trademark), and other radio communication protocols. In the present embodiment, the additional radio communicator WC2 is configured to encrypt signals using a cryptographic key to generate encrypted radio signals. The additional radio communicator WC2 is configured to transmit radio signals via the antenna. The additional radio communicator WC2 may be a one-way radio communication device such as a receiver or a two-way radio communication device such as a transceiver.

The additional radio communicator WC2 is configured to receive radio signals via the antenna. In the present embodiment, the additional radio communicator WC2 is configured to decrypt the radio signals to recognize the signals transmitted by other radio communicators. The additional radio communicator WC2 is configured to decrypt the radio signals using the cryptographic key.

The display 46 is configured to display the rotation information(s) INF1 (e.g. the power INF11, the rotation speed INF12) wirelessly transmitted from the radio communicator WC1 of the electrical device 27. The additional electronic control EC2 is configured to control the display 46 to display the rotation information(s) INF1 (e.g. the power INF11, the rotation speed INF12).

The user interface 48 is configured to receive user input. Examples of the user interface 48 include a mouse, a keyboard, and a touch panel. The additional electronic controller EC2 is configured to receive the user input via the user interface 48.

The additional electrical device 6 includes an electrical power source 52 and a power source holder 54. The power source 52 is electrically connected to the additional radio communicator WC2, the additional electronic controller EC2, the display 46 and the user interface 48 to supply electricity to the additional radio communicator WC2, the additional electronic controller EC2, the display 46 and the user interface 48. The power source holder 54 is electrically connected to the additional radio communicator WC2, the additional electronic controller EC2, the display 46 and the user interface point 48 to supply the additional radio communicator WC2, the additional electronic controller EC2, the display 46 and the user interface 48 with electricity from the electric power source 52. The power source holder 54 is configured to detachably hold the electric power source 52. Examples of the electric power source 52 include a battery (e.g., a primary battery, a secondary battery).

As in 5 As can be seen, the electrical device 27 is configured to communicate with an external electrical device 8. The external electrical device 8 is configured to receive a user input INF2 from the user. The external electrical device 8 is configured to transmit the user input INF2 to the electrical device 27. The electronic controller EC1 is configured to receive the user input INF2 from the external electrical device 8. Examples of the external electrical device 8 include a cyclocomputer, a smartphone, a tablet computer, and a personal computer.

The external electrical device 8 includes an external radio communicator WC3, an external electronic controller EC3, a display 56 and a user interface 58. The external electronic controller EC3 is electrically connected to the external radio communicator WC3, the display 56 and the user interface 58 to control the external radio communicator WC3, the display 56 and the user interface 58.

As in 5 As can be seen, the external electronic control EC3 includes a processor 60P, a memory 60M, a printed circuit board 60C, and a bus 60D. The processor 60P is connected to the memory 60M. The memory 60M is coupled to the processor 60P. The processor 60P and the memory 60M are electrically mounted on the printed circuit board 60C. The processor 60P is electrically connected to the memory 60M via the printed circuit board 60C and the bus 60D. The memory 60M is electrically connected to the processor 60P via the printed circuit board 60C and the bus 60D. The bus 60D is provided on the printed circuit board 60C. The external electronic control EC3 includes a semiconductor.

The processor 60P includes, for example, at least one of a CPU, an MPU, and a memory controller. The memory 60M is electrically connected to the processor 60P. The memory 60M includes, for example, at least one of a volatile memory and a non-volatile memory. Examples of the volatile memory include a RAM and a DRAM. Examples of the non-volatile memory include a ROM, an EEPROM, and an HDD. The memory 60M includes memory areas, each with an address. The processor 60P is configured to control the memory 60M, store data in the memory areas of the memory 60M, and read data from the memory areas of the memory 60M. The processor 60P may also be referred to as a hardware processor 60P. The memory 60M may also be referred to as a hardware storage 60M. The memory 60M may also be referred to as a computer-readable storage medium 60M.

The external electronic controller EC3 is programmed to execute at least one control algorithm of the additional electrical device 6. The memory 60M (e.g. the ROM) stores at least one program with at least one program instruction. The at least one program is read into the processor 60P, and thereby the at least one control algorithm of the additional electrical device 6 is executed based on the at least one program. The external electronic controller EC3 may also be referred to as an electronic control circuit or electronic control circuit EC3. The external electronic controller EC3 may also be referred to as an external electronic hardware controller EC3.

The structure of the external electronic controller EC3 is not limited to the above structure. The structure of the external electronic controller EC3 is not limited to the processor 60P, the memory 60M, and the bus 60D. The external electronic controller EC3 can be realized by pure hardware or a combination of hardware and software. The processor 60P and the memory 60M can be integrated as a chip such as an ASIC or an FPGA.

The external radio communicator WC3 is arranged to communicate wirelessly with another radio communicator such as the radio communicator WC1 and the additional radio communicator WC2. However, the external electrical device 8 may also include an external wired communicator if required and/or desired. The external wired communicator is arranged to communicate with the electrical device 27 via an electrical cable using power line communication technology (PLC).

As in 5 As can be seen, the external radio communicator WC3 is electrically connected to the processor 60P and the memory 60M via the circuit board 60C and the bus 60D. The external radio communicator WC3 is electrically mounted on the circuit board 60C. The external radio communicator WC3 contains a signal transmission circuit or a signal transmission circuit, a signal reception circuit or a signal reception circuit and an antenna. Therefore, the external radio communicator WC3 can also be called an external radio communicator circuit or external radio communicator circuit WC3.

The external radio communicator WC3 is configured to superimpose digital signals on carrier waves using a predetermined radio communication protocol to transmit signals wirelessly. Examples of the predetermined radio communication protocol are Wi-Fi (registered trademark), Zigbee (registered trademark), Bluetooth (registered trademark), ANT (registered trademark), and other radio communication protocols. In the present embodiment, the external radio communicator WC3 is configured to encrypt signals using a cryptographic key to generate encrypted radio signals. The external radio communicator WC3 is configured to transmit radio signals via the antenna. The external radio communicator WC3 may be a one-way radio communication device such as a receiver or a two-way radio communication device such as a transceiver.

The external radio communicator WC3 is configured to receive radio signals via the antenna. In the present embodiment, the external radio communicator WC3 is configured to decrypt the radio signals to recognize the signals transmitted from other external radio communicators. The external radio communicator WC3 is configured to decrypt the radio signals using the cryptographic key.

The display 56 is arranged to display information(s) relating to the human-powered vehicle 2. The external electronic controller EC3 is arranged to control the display 56 to display the information(s) relating to the human-powered vehicle 2. The information(s) relating to the human-powered vehicle 2 includes, for example, the rotation information(s) INF1 and the settings of the crank assembly 10.

The user interface 58 is configured to receive the user input INF2. Examples of the user interface 58 include a mouse, a keyboard, and a touch panel. The external electronic controller EC3 is configured to receive the user input via the user interface 58. The external electronic controller EC3 is configured to receive the user input INF2 via the user interface 58.

The electronic controller EC1 is configured to receive the user input INF2 from the external electrical device 8. The electronic controller EC1 is configured to receive the user input INF2 via the radio communicator WC1 and the external radio communicator WC3. The electronic controller EC1 is configured, for example, to change the settings based on the user input INF2.

The external electrical device 8 includes an electrical power source 62 and a power source holder 64. The electrical power source 62 is electrically connected to the external radio communicator WC3, the external electronic controller EC3, the display 56, and the user interface 58 to supply electricity to the external radio communicator WC3, the external electronic controller EC3, the display 56, and the user interface 58. The power source holder 64 is electrically connected to the external radio communicator WC3, the external electronic controller EC3, the display 56, and the user interface 58 to supply electricity from the electrical power source 62 to the external radio communicator WC3, the external electronic controller EC3, the display 56, and the user interface 58. The power source holder 64 is configured to detachably hold the electrical power source 62. Examples of the electrical power source 62 include a battery (e.g., a primary battery, a secondary battery).

As in 5 As can be seen, the electronic controller EC1 is configured to control the radio communicator WC1 to wirelessly transmit the rotation information(s) INF1 at predetermined intervals. The electronic controller EC1 is configured to control the radio communicator WC1 to wirelessly transmit the rotation information(s) INF1 using radio signals at the predetermined intervals. The electronic controller EC1 is configured to control the radio communicator WC1 to wirelessly transmit the power INF11 and the rotation speed INF12 using the radio signals at the predetermined intervals.

The additional radio communicator WC2 of the additional electrical device 6 is arranged to wirelessly receive the rotation information INF1 transmitted from the radio communicator WC1 of the electrical device 27 at the predetermined intervals. The additional radio communicator WC2 of the additional electrical device 6 is arranged to wirelessly transmit the power ation INF 11 and the rotation speed INF12 transmitted from the radio communicator WC1 of the electrical device 27 at the predetermined intervals.

The additional electronic controller EC2 of the additional electric device 6 is configured to control the display 46 to display the rotation information INF1 wirelessly received from the additional radio communicator WC2 at the predetermined intervals. The additional electronic controller EC2 is configured to control the display 46 to display the power INF11 and the rotation speed INF12 wirelessly received from the additional radio communicator WC2 at the predetermined intervals. The additional electronic controller EC2 is configured to control the display 46 to display the latest values of the power INF11 and the rotation speed INF12. Thus, the user can recognize the power INF11 and the rotation speed INF12 of the crank assembly 10 via the display 46 of the additional electric device 6 while pedaling.

As in 6 As can be seen, the force sensor 32 includes a first strain gauge G1, a second strain gauge G2, a third strain gauge G3, and a fourth strain gauge G4. The sensor body 34 includes the first strain gauge G1, the second strain gauge G2, the third strain gauge G3, and the fourth strain gauge G4. The crank arm 14 is free from any strain gauge other than the first strain gauge G1, the second strain gauge G2, the third strain gauge G3, and the fourth strain gauge G4. The force sensor 32 is free from any strain gauge other than the first strain gauge G1, the second strain gauge G2, the third strain gauge G3, and the fourth strain gauge G4. The first strain gauge G1, the second strain gauge G2, the third strain gauge G3 and the fourth strain gauge G4 are provided integrally. However, at least one of the first strain gauge G1, the second strain gauge G2, the third strain gauge G3 and the fourth strain gauge G4 may, if required and/or desired, be provided separately from another of the first strain gauge G1, the second strain gauge G2, the third strain gauge G3 and the fourth strain gauge G4.

The sensor body 34 is provided on the mounting surface 14S. The first strain gauge G1, the second strain gauge G2, the third strain gauge G3, and the fourth strain gauge G4 are provided on the mounting surface 14S. The first strain gauge G1 is attached to the crank arm 14. The second strain gauge G2 is attached to the crank arm 14. The third strain gauge G3 is attached to the crank arm 14. The fourth strain gauge G4 is attached to the crank arm 14. The sensor body 34 is attached to the mounting surface 14S with, for example, an adhesive.

When viewed along the first hole center axis CA11, the first strain gauge G1 is closer to the first hole center axis CA11 than the third strain gauge G3 and the fourth strain gauge G4. When viewed along the first hole center axis CA11, the second strain gauge G2 is closer to the first hole center axis CA11 than the third strain gauge G3 and the fourth strain gauge G4.

The longitudinal axis LA1 defines a first region R1 and a second region R2 when viewed in the axial direction D2. The longitudinal axis LA1 is arranged between the first region R1 and the second region R2 when viewed in the axial direction D2. The first strain gauge G1 and the third strain gauge G3 are provided in the first region R1 when viewed in the axial direction D2. The second strain gauge G2 and the fourth strain gauge G4 are provided in the second region R2 when viewed in the axial direction D2.

The first strain gauge G1 is symmetrical to the second strain gauge G2 when viewed in the axial direction D2 with respect to the longitudinal axis LA1. The third strain gauge G3 is symmetrical to the fourth strain gauge G4 when viewed in the axial direction D2 with respect to the longitudinal axis LA1.

As in 6 As can be seen, a first longitudinal distance LD1 is defined in a first direction D41 when viewed in the axial direction D2 between the first strain gauge G1 and the axis of rotation A1. The first direction D41 is defined such that it runs parallel to the longitudinal axis LA1 when viewed in the axial direction D2. A second longitudinal distance LD2 is defined in the first direction D41 when viewed in the axial direction D2 between the second strain gauge G2 and the axis of rotation A1.

For example, the first longitudinal distance LD1 when viewed in the axial direction D2 is between between the first measuring center GC1 of the first strain gauge G1 and the axis of rotation A1 in the first direction D41. The second longitudinal distance LD2 is defined when viewed in the axial direction D2 between the second measuring center GC2 of the second strain gauge G2 and the axis of rotation A1 in the first direction D41.

A third longitudinal distance LD3 is defined when viewed in the axial direction D2 between the third strain gauge G3 and the first hole center axis CA11 in the first direction D41. A fourth longitudinal distance LD4 is defined when viewed in the axial direction D2 between the fourth strain gauge G4 and the first hole center axis CA11 in the first direction D41.

For example, the third longitudinal distance LD3 is defined when viewed in the axial direction D2 between the third measuring center GC3 of the third strain gauge G3 and the rotation axis A1 in the first direction D41. The fourth longitudinal distance LD4 is defined when viewed in the axial direction D2 between the fourth measuring center GC4 of the fourth strain gauge G4 and the rotation axis A1 in the first direction D41.

The first longitudinal distance LD1 is equal to the second longitudinal distance LD2. The third longitudinal distance LD3 is equal to the fourth longitudinal distance LD4. The first longitudinal distance LD1 is shorter than the third longitudinal distance LD3 and the fourth longitudinal distance LD4. The second longitudinal distance LD2 is shorter than the third longitudinal distance LD3 and the fourth longitudinal distance LD4.

A first vertical distance PD1 is defined in a second direction D42 when viewed in the axial direction D2 between the first strain gauge G1 and the longitudinal axis LA1. The second direction D42 when viewed in the axial direction D2 runs perpendicular to the longitudinal axis LA1. A second vertical distance PD2 is defined in the second direction D42 when viewed in the axial direction D2 between the second strain gauge G2 and the longitudinal axis LA1.

For example, the first vertical distance PD1 is defined in the second direction D42 between the first measuring center GC1 of the first strain gauge G1 and the longitudinal axis LA1 when viewed in the axial direction D2. The second vertical distance PD2 is defined in the second direction D42 between the second measuring center GC2 of the second strain gauge G2 and the longitudinal axis LA1 when viewed in the axial direction D2.

A third vertical distance PD3 is defined when viewed in the axial direction D2 between the third strain gauge G3 and the longitudinal axis LA1 in the second direction D42. A fourth vertical distance PD4 is defined when viewed along the rotation axis A1 between the fourth strain gauge G4 and the longitudinal axis LA1 in the second direction D42.

For example, the third vertical distance PD3 is defined in the second direction D42 between the third measuring center GC3 of the third strain gauge G3 and the longitudinal axis LA1 when viewed in the axial direction D2. The fourth vertical distance PD4 is defined in the second direction D42 between the fourth measuring center GC4 of the fourth strain gauge G4 and the longitudinal axis LA1 when viewed in the axial direction D2.

The first vertical distance PD1 is equal to the second vertical distance PD2. The third vertical distance PD3 is equal to the fourth vertical distance PD4. The first vertical distance PD1 is equal to the third vertical distance PD3 and the fourth vertical distance PD4. The second vertical distance PD2 is equal to the third vertical distance PD3 and the fourth vertical distance PD4.

As in 7 , the sensor body 34 includes a resin film 34A. The first strain gauge G1, the second strain gauge G2, the third strain gauge G3, and the fourth strain gauge G4 are provided on the resin film 34A. The resin film 34A has electrical insulation. One of the first strain gauge G1, the second strain gauge G2, the third strain gauge G3, and the fourth strain gauge G4 is electrically insulated from another of the first strain gauge G1, the second strain gauge G2, the third strain gauge G3, and the fourth strain gauge G4 by the resin film 34A.

The first strain gauge G1 has a first measurement axis GA1. The first strain gauge G1 is configured to produce a first output indicative of a first amount of deformation occurring along the first measurement axis GA1. For example, the measurement circuit 36 is electrically connected to the first strain gauge G1 to convert the output of the first strain gauge G1 into a voltage indicative of the first output.

The second strain gauge G2 has a second measuring axis GA2. The second strain The second strain gauge G2 is configured to produce a second output indicative of a second amount of strain occurring along the second measurement axis GA2. For example, the measurement circuit 36 is electrically connected to the second strain gauge G2 to convert the output of the second strain gauge G2 into a voltage indicative of the second output.

The third strain gauge G3 has a third measurement axis GA3. The third strain gauge G3 is configured to produce a third output indicative of a third amount of deformation occurring along the third measurement axis GA3. For example, the measurement circuit 36 is electrically connected to the third strain gauge G3 to convert the output of the third strain gauge G3 into a voltage indicative of the third output.

The fourth strain gauge G4 has a fourth measurement axis GA4. The fourth strain gauge G4 is configured to produce a fourth output indicative of a fourth amount of deformation occurring along the fourth measurement axis GA4. For example, the measurement circuit 36 is electrically connected to the fourth strain gauge G4 to convert the output of the fourth strain gauge G4 into a voltage indicative of the fourth output.

As in 7 , the first strain gauge G1 includes at least two first longitudinal wires G11 and at least one first intermediate wire G12. The at least two first longitudinal wires G11 and the at least one first intermediate wire G12 are provided on the resin film 34A. The at least two first longitudinal wires G11 extend along the first measuring axis GA1. The at least one first intermediate wire G12 connects two adjacent longitudinal wires of the at least two first longitudinal wires G11. The at least two first longitudinal wires G11 have a straight shape extending along the first measuring axis GA1. The at least one first intermediate wire G12 has a curved shape. However, the shape of the first strain gauge G1 is not limited to the illustrated shape.

The first strain gauge G1 has a first width W1. The first width W1 is defined in a first width direction WD1, which runs perpendicular to the first measuring axis GA1 when viewed in the axial direction D2. The first measuring axis GA1 is defined such that it halves the first width W1 when viewed in the axial direction D2. The first strain gauge G1 has a first measuring center GC1. The first measuring center GC1 is defined on the first measuring axis GA1.

The second strain gauge G2 includes at least two second longitudinal wires G21 and at least one second intermediate wire G22. The at least two second longitudinal wires G21 and the at least one second intermediate wire G22 are provided on the resin film 34A. The at least two second longitudinal wires G21 extend along the second measuring axis GA2. The at least one second intermediate wire G22 connects two adjacent longitudinal wires of the at least two second longitudinal wires G21. The at least two second longitudinal wires G21 have a straight shape extending along the second measuring axis GA2. The at least one second intermediate wire G22 has a curved shape. However, the shape of the second strain gauge G2 is not limited to the illustrated shape.

The second strain gauge G2 has a second width W2. The second width W2 is defined in a second width direction WD2, which runs perpendicular to the second measuring axis GA2 when viewed in the axial direction D2. The second measuring axis GA2 is defined such that it halves the second width W2 when viewed in the axial direction D2. The second strain gauge G2 has a second measuring center GC2. The second measuring center GC2 is defined on the second measuring axis GA2.

The third strain gauge G3 includes at least two third longitudinal wires G31 and at least one third intermediate wire G32. The at least two third longitudinal wires G31 and the at least one third intermediate wire G32 are provided on the resin film 34A. The at least two third longitudinal wires G31 extend along the third measuring axis GA3. The at least one third intermediate wire G32 connects two adjacent longitudinal wires of the at least two third longitudinal wires G31. The at least two third longitudinal wires G31 have a straight shape extending along the third measuring axis GA3. The at least one third intermediate wire G32 has a curved shape. However, the shape of the third strain gauge G3 is not limited to the illustrated shape.

The third strain gauge G3 has a third width W3. The third width W3 is defined in a third width direction WD3, which runs perpendicular to the third measuring axis GA3 when viewed in the axial direction D2. The third measuring axis GA3 is defined such that it halves the third width W3 when viewed in the axial direction D2. The third strain gauge G3 has a third measuring center GC3. The third measuring center GC3 is defined on the third measuring axis GA3.

The fourth strain gauge G4 includes at least two fourth longitudinal wires G41 and at least one fourth intermediate wire G42. The at least two fourth longitudinal wires G41 and at least one fourth intermediate wire G42 are provided on the resin film 34A. The at least two fourth longitudinal wires G41 extend along the fourth measuring axis GA4. The at least one fourth intermediate wire G42 connects two adjacent longitudinal wires of the at least two fourth longitudinal wires G41. The at least two fourth longitudinal wires G41 have a straight shape extending along the fourth measuring axis GA4. The at least one fourth intermediate wire G42 has a curved shape. However, the shape of the fourth strain gauge G4 is not limited to the illustrated shape.

The fourth strain gauge G4 has a fourth width W4. The fourth width W4 is defined in a fourth width direction WD4, which runs perpendicular to the fourth measuring axis GA4 when viewed in the axial direction D2. The fourth measuring axis GA4 is defined such that it halves the fourth width W4 when viewed in the axial direction D2. The fourth strain gauge G4 has a fourth measuring center GC4. The fourth measuring center GC4 is defined on the fourth measuring axis GA4.

The force sensor 32 includes first electrical terminals GT11 and GT12, second electrical terminals GT21 and GT22, third electrical terminals GT31 and GT32, and fourth electrical terminals GT41 and GT42. The force sensor 32 includes first wirings GW11 and GW12, second wirings GW21 and GW22, third wirings GW31 and GW32, and fourth wirings GW41 and GW42. The first electrical terminals GT11 and GT12, the second electrical terminals GT21 and GT22, the third electrical terminals GT31 and GT32, and the fourth electrical terminals GT41 and GT42 are provided on the resin film 34A. The first wirings GW11 and GW12, the second wirings GW21 and GW22, the third wirings GW31 and GW32, and the fourth wirings GW41 and GW42 are provided on the resin film 34A.

The first electrical terminals GT11 and GT12 are connected to the first strain gauge G1 via the first wirings GW11 and GW12. The second electrical terminals GT21 and GT22 are connected to the second strain gauge G2 via the second wirings GW21 and GW22. The third electrical terminals GT31 and GT32 are connected to the third strain gauge G3 via the third wirings GW31 and GW32. The fourth electrical terminals GT41 and GT42 are connected to the fourth strain gauge G4 via the fourth wirings GW41 and GW42. The first electrical terminals GT11 and GT12, the second electrical terminals GT21 and GT22, the third electrical terminals GT31 and GT32, and the fourth electrical terminals GT41 and GT42 are electrically connected to the measuring circuit 36.

As in 7 As can be seen, the first strain gauge G1, the second strain gauge G2, the third strain gauge G3 and the fourth strain gauge G4 are arranged so as to satisfy a first equation (1). For example, a calculation result of the first equation (1) is in the range of 3 degrees to 5 degrees. $$\theta 1-\mathrm{<figure-callout\; id="2"\; label="\theta "\; filenames="DE102022131718A1\_0008.png,DE102022131718A1\_0012.png"\; state="\{\{state\}\}">\theta </figure-callout>}2+\theta -\mathrm{<figure-callout\; id="4"\; label="\theta "\; filenames="DE102022131718A1\_0008.png,DE102022131718A1\_0017.png"\; state="\{\{state\}\}">\theta </figure-callout>}4=-\frac{2}{\left(1+v\right)}\frac{Ip}{I}\frac{L2}{L1}\theta a$$

θ1 represents a first angle defined between the longitudinal axis LA1 and the first measuring axis GA1 when viewed in the axial direction D2. θ2 represents a second angle defined between the longitudinal axis LA1 and the second measuring axis GA2 when viewed in the axial direction D2. θ3 represents a third angle defined between the longitudinal axis LA1 and the third measuring axis GA3 when viewed in the axial direction D2. θ4 represents a fourth angle defined between the longitudinal axis LA1 and the fourth measuring axis GA4 when viewed in the axial direction D2.

As in 8th , v represents the Poisson's ratio of the material of the crank arm 14. Examples of the material of the crank arm 14 include aluminum, iron, titanium, and stainless steel. For example, in a case where the material of the crank arm 14 includes aluminum, the Poisson's ratio v is 0.33. However, the material of the crank arm 14 and its Poisson's ratio are not limited to the above materials and values.

Ip represents a second polar area moment of the crank arm 14. I represents a second area moment of the crank arm 14. The crank arm 14 has a reference cross-section RC which is 8th The reference cross-section RC is cut along a first reference plane RP1 (see e.g. 4 ) perpendicular to the longitudinal axis LA1. The reference cross section RC is recorded on the sensor body 34 of the force sensor 32. In the 8th In the reference cross-section RC shown, the crank arm 14 has a first outer length B1, a second outer length H1, a first inner length B2 and a second inner length H2. The second polar area moment Ip of the crank arm 14 is calculated on the basis of the first outer length B1, the second outer length H1, the first inner length B2 and the second inner length H2. The second surface torque I of the crank arm 14 is calculated based on the first outer length B1, the second outer length H1, the first inner length B2 and the second inner length H2.

L1 represents a first distance defined from a center point C of the reference cross-section RC to the first strain gauge G1 in the reference cross-section RC. L2 represents a second distance defined from the center point C of the reference cross-section RC to the first strain gauge G1 in a direction D5 perpendicular to the first hole center axis CA11 and the longitudinal axis LA1. The first distance L1 is defined, for example, from the center point C of the reference cross-section RC to the first measuring center point GC1 of the first strain gauge G1 in the reference cross-section RC. The second distance L2 is defined from the center point C of the reference cross-section RC to the first measuring center point GC1 of the first strain gauge G1 in the direction D5.

In the present embodiment, the first distance L1 is equal to a distance L12 defined from the center C of the reference cross section RC to the second strain gauge G2 in the reference cross section RC. The first distance L1 is equal to a distance L13 defined from the center C of the reference cross section RC to the third strain gauge G3 in the reference cross section RC. The first distance L1 is equal to the distance L14 defined from the center C of the reference cross section RC to the fourth strain gauge G4 in the reference cross section RC. The distance L12 is defined, for example, from the center C of the reference cross section RC to the second measurement center GC2 of the second strain gauge G2 in the reference cross section RC. The distance L13 is defined from the center C of the reference cross section RC to the third measurement center GC3 of the third strain gauge G3 in the reference cross section RC. The distance L14 is defined from the center C of the reference cross-section RC to the fourth measuring center GC4 of the fourth strain gauge G4 in the reference cross-section RC.

The second distance L2 is equal to a distance L22 defined from the center C of the reference cross-section RC to the second strain gauge G2 in the direction D5. The second distance L2 is equal to a distance L23 defined from the center C of the reference cross-section RC to the third strain gauge G3 in the direction D5. The second distance L2 is equal to a distance L24 defined from the center C of the reference cross-section RC to the fourth strain gauge G4 in the direction D5. The distance L22 is defined, for example, from the center C of the reference cross-section RC to the second measuring center GC2 of the second strain gauge G2 in the direction D5. The distance L23 is defined from the center C of the reference cross-section RC to the third measuring center GC3 of the third strain gauge G3 in the direction D5. The distance L24 is defined from the center C of the reference cross-section RC to the fourth measuring center GC4 of the fourth strain gauge G4 in the direction D5.

As in 4 , θa represents an inclination angle defined between the longitudinal axis LA1 and a second reference plane RP2 perpendicular to the first hole center axis CA11.

As in 7 , the electronic controller EC1 is electrically connected to the first strain gauge G1, the second strain gauge G2, the third strain gauge G3, and the fourth strain gauge G4. The electronic controller EC1 is configured to calculate a deformation amount of the crank arm 14 based on the first output, the second output, the third output, the fourth output, and a second equation (2). $$E=E1-\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="DE102022131718A1\_0008.png,DE102022131718A1\_0012.png"\; state="\{\{state\}\}">E</figure-callout>}2+E3-\mathrm{<figure-callout\; id="4"\; label="E"\; filenames="DE102022131718A1\_0008.png,DE102022131718A1\_0017.png"\; state="\{\{state\}\}">E</figure-callout>}4$$

E represents the deformation amount of the crank arm 14. E1 represents the first output. E2 represents the second output. E3 represents the third output. E4 represents the fourth output. For example, the measuring circuit 36 is configured to convert the output of the first strain gauge G1 into a voltage indicating the first output E1. The measuring circuit 36 is configured to convert the output of the second strain gauge G2 into a voltage indicating the second output E2. The measuring circuit 36 is configured to convert the output of the third strain gauge G3 into a voltage indicating the third output E3. The measuring circuit 36 is configured to convert the output of the fourth strain gauge G4 into a voltage indicating the fourth output E4. The electronic controller EC1 is configured to calculate the deformation amount E of the crank arm 14 based on the first output E1, the second output E2, the third output E3, and the fourth output E4 and the second equation (2).

As in 9 As can be seen, the electrical device 27 may be provided on the crank arm 18 if necessary and/or desired. In such embodiments, the crank assembly 10 includes at least one of the electrical device 27, the provided on the crank arm 14, and the electrical device 27 provided on the crank arm 18. The electrical device 27 provided on the crank arm 18 is configured to wirelessly transmit the rotation information(s) INF1 of the crank arm 18, while the electrical device 27 provided on the crank arm 14 is configured to wirelessly transmit the rotation information(s) INF1 of the crank arm 14. The additional electrical device 6 is configured to separately display the power INF 11 applied to the crank arm 14 and the power INF 11 applied to the crank arm 18. The additional electrical device 6 is configured to display one of the rotational speed INF12 of the crank arm 14 and the rotational speed INF12 of the crank arm 18. The additional electrical device 6 may be configured to display an average value of the rotational speed INF12 of the crank arm 14 and the rotational speed INF12 of the crank arm 18.

Second embodiment

A crank assembly 210 according to a second embodiment will be described below with reference to 10 and 11 The crank assembly 210 has the same structure and/or construction as that of the crank assembly 10, except for the arrangement of the electrical device 27. Therefore, elements having substantially the same function as in the first embodiment are numbered the same here and will not be described and/or illustrated in detail again here for the sake of brevity.

As in the 10 and 11 , the crank assembly 210 includes the crank arm 14 and the crank axle 16. The crank assembly 210 includes an electrical device 227. The electrical device 227 has substantially the same structure as the structure of the electrical device 27 of the first embodiment. The electrical device 227 is at least partially provided on at least one of the crank axle 16, the crank arm 14, and the sprocket 20 and/or 22. The electrical device 227 is at least partially provided on the crank arm 14.

As in 11 As can be seen, the electrical device 227 is provided partly on the crank arm 14, partly on the crank axle 16 and partly on the crank arm 18. The radio communicator WC1, the electronic controller EC1, the force sensor 32 and the position detector 38 are attached to the crank arm 14. The electric power source 42 and the power source holder 44 are provided on the crank axle 16. The electric connection terminal 45 is provided on the crank arm 18. The power source holder 44 is connected to the electronic controller EC1 and the electric connection terminal 45 via an electric cable.

As in 10 As can be seen, the electrical device 227 includes the housing 28 and an additional housing 224. The additional housing 224 is attached to the crank arm 18. The electrical connection port 45 is coupled to the additional housing 224. The additional housing 224 includes, for example, a housing body 224A and a cover 224B. The housing body 224A is attached to the crank arm 18. The cover 224B is removably attached to the housing body 224A to at least partially cover the electrical connection port 45. The electrical connection port 45 can be connected to an electrical cable to charge the electrical power source 42 via the electrical connection port 45 and the power source holder 44.

As in the 12 As can be seen in the modification shown, the electrical device 227 can be provided at least partially on the sprocket 20 if necessary and/or desired. The additional housing 224 can be attached to the sprocket 20 if necessary and/or desired.

Third embodiment

A crank assembly 310 according to a third embodiment will be described below with reference to 13 to 15 The crank assembly 310 has the same structure and/or design as the crank assembly 210, with the exception of an additional force sensor. Therefore, elements that have substantially the same function as in the first and second embodiments are numbered the same here and are not described and/or illustrated again in detail here for the sake of brevity.

As in the 13 and 14 As can be seen, the crank assembly 310 includes the crank arm 14 and the crank axle 16. The crank assembly 310 includes an electrical device 327 and a force sensor 332. The electrical device 327 has substantially the same structure as the structure of the electrical device 327 of the second embodiment. The force sensor 332 has substantially the same structure as the structure of the force sensor 32 of the first embodiment. The electrical device 327 is provided at least partially on one of the crank axle 16, the crank arm 14 and the sprocket 20 and/or 22. The electrical device 327 is at least partially provided on the crank arm 14.

As in 14 As can be seen, the electrical device 327 is provided partly on the crank arm 14, partly on the crank axle 16 and partly on the crank arm 18. The radio communicator WC1, the electronic controller EC1, the force sensor 32 and the position detector 38 are provided on the crank arm 14. The electric power source 42 and the power source holder 44 are provided on the crank axle 16. The electric connection port 45 is provided on the crank arm 18. The power source holder 44 is connected to the electronic controller EC1 via an electric cable. The power source holder 44 is connected to the electric connection port 45 via an electric cable.

The radio communicator WC1 is configured to wirelessly transmit the rotation information(s) INF1 relating to the crank assembly 310. The rotation information(s) INF1 include(s) the power INF11 and the rotation speed INF12 of the crank assembly 310 (e.g., the crank arm 14). In addition, the radio communicator WC1 is configured to wirelessly transmit rotation information(s) INF3 relating to the crank assembly 310 (e.g., the crank arm 18).

The electrical device 327 for the crank assembly 310 of the human-powered vehicle 2 comprises a force sensor 332. The force sensor 332 is configured to determine the rotational information(s) INF3. The rotational information(s) INF3 contains a force exerted on the crank assembly 310 (e.g. the crank arm 18) in the rotational direction D1 (see e.g. 15 ). Therefore, the force sensor 332 is configured to measure the force exerted on the crank assembly 310. The force sensor 332 is configured to output a measurement value indicative of the force exerted on the crank assembly 310 in the rotational direction D1. In the present embodiment, the force sensor 332 is configured to measure the force exerted on the crank arm 18. However, the force sensor 332 may be configured to measure the force exerted on another part of the crank assembly 10 if needed and/or desired.

The electronic controller EC1 is configured to receive the rotation information INF3 determined by the force sensor 332. The electronic controller EC1 is electrically connected to the force sensor 332 to receive the rotation information INF3 determined by the force sensor 332. The electronic controller EC1 is configured to receive the force measured by the force sensor 332. The electronic controller EC1 is electrically connected to the force sensor 332 to receive the force measured by the force sensor 332.

The force sensor 332 includes, for example, a sensor body 334 and a measuring circuit 336. The sensor body 334 is attached to the crank arm 18. The sensor body 334 is configured to output a change in electrical resistance depending on the degree of deformation of the crank assembly 310. The sensor body 334 is configured to output the change in electrical resistance depending on the amount of deformation of the crank arm 18. The measuring circuit 336 is electrically connected to the sensor body 334 to convert the output of the sensor body 334 into a voltage indicative of the amount of deformation of the crank assembly 310 (e.g., the crank arm 18). The measuring circuit 336 forms, for example, a bridge circuit with the force sensor 332.

The measuring circuit 336 is electrically connected to the electronic controller EC1. The measuring circuit 336 is electrically mounted on the circuit board 30C of the electronic controller EC1. The measuring circuit 336 is electrically connected to the sensor body 334 via, for example, the circuit board 30C and an additional circuit board such as a flexible printed circuit. The electronic controller EC1 is electrically connected to the measuring circuit 336 to receive the rotation information(s) INF1. The electronic controller EC1 is electrically connected to the measuring circuit 336 to receive the deformation amount of the crank assembly 310 (e.g., the crank arm 18).

As in the 13 and 15 As can be seen, the electrical device 327 includes the housing 28, the additional housing 224 and an additional housing 324. The additional housing 324 is attached to the crank arm 18. As shown in 14 As can be seen, the force sensor 332 is provided in the additional housing 324. The electrical connection port 45 can be coupled to the additional housing 324 if needed and/or desired. In such embodiments, the additional housing 224 can be omitted from the electrical device 327.

The force sensor 332 has substantially the same structure as the structure of the force sensor 32 described and illustrated in the first embodiment. Therefore, the description of the force sensor 32 can also be used as the description of the force sensor 332. Therefore, for the sake of brevity, it will not be described in detail here.

In the present application, the term “comprising” and its derivatives, as used herein, are intended to be open-ended terms, which which specify the presence of the named features, elements, components, groups, integers and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. This concept also applies to words which have a similar meaning, such as the terms "including", "having" and their derivatives.

Also, the terms “limb,” “section,” “part,” “part,” “element,” “body,” and “structure,” when used in the singular, can have the dual meaning of a single part or a plurality of parts.

The ordinal numbers such as "first" and "second" as mentioned in the present application are merely identifiers, but have no further meaning such as a particular order or the like. In addition, for example, the term "first element" does not in itself imply the presence of a "second element", and the term "second element" does not in itself imply the presence of a "first element".

The term “pair of” as used herein may include the configuration in which the pair of elements have different shapes or structures from each other, in addition to the configuration in which the pair of elements have similar shapes or structures to each other.

The terms “a” (or “an”), “one or more” and “at least one” may be used interchangeably herein.

The phrase "at least one of," as used in this disclosure, means "one or more" of a desired selection. For example, the phrase "at least one," as used in this disclosure, means "only a single selection" or "both of two selections" when the number of selections is two. For example, the phrase "at least one," as used in this disclosure, means "only a single selection" or "any combination of equal to or more than two selections" when the number of selections is equal to or more than three. For example, the phrase “at least one of A and B” includes (1) A alone, (2) B alone, and (3) both A and B. The phrase “at least one of A, B, and C” includes (1) A alone, (2) B alone, (3) C alone, (4) both A and B, (5) both B and C, (6) both A and C, and (7) all of A, B, and C. In other words, the phrase “at least one of A and B” in this disclosure does not mean “at least one of A and at least one of B.”

Finally, as used herein, terms such as "substantial," "about," and "approximately" mean a reasonable amount of deviation from the modified term so that the end result is not materially changed. All numerical values described in this application can be construed to include the terms "substantial," "about," and "approximately."

Of course, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

REFERENCE SIGNS

18

Crank arm

14A

Arm body

18B

Crank axle mounting hole

CA11

first hole center axis

18C

Pedal axle mounting hole

CA12

second hole center axis

LA1

Longitudinal axis

32; 323

Force sensor

G1

first strain gauge

GA1

first measuring axis

G2

second strain gauge

GA2

second measuring axis

G3

third strain gauge

GA3

third measuring axis

G4

fourth strain gauge

GA4

fourth measuring axis

14D

first end of the arm

14E

second arm end

14S

Mounting surface

EC1

electronic control

16

Crank axle

Claims (12)

A crank arm for a human-powered vehicle, comprising: an arm body having a crank axle mounting hole with a first hole center axis defining an axial direction, a pedal axle mounting hole having a second hole center axis parallel to the first hole center axis and a longitudinal axis extending to pass through the first hole center axis and the second hole center axis; a force sensor comprising: a first strain gauge attached to the crank arm and having a first measuring axis, the first strain gauge configured to produce a first output indicative of a first amount of deformation occurring along the first measuring axis; a second strain gauge attached to the crank arm and having a second measuring axis, the second strain gauge configured to produce a second output indicative of a second amount of deformation occurring along the second measuring axis; a third strain gauge attached to the crank arm and having a third measuring axis, the third strain gauge configured to produce a third output indicative of a third amount of deformation occurring along the third measuring axis; and a fourth strain gauge attached to the crank arm and having a fourth measurement axis, the fourth strain gauge configured to produce a fourth output indicative of a fourth amount of deformation occurring along the fourth measurement axis; wherein the first strain gauge is closer to the first hole center axis than the third strain gauge and the fourth strain gauge when viewed along the first hole center axis; wherein the second strain gauge is closer to the first hole center axis than the third strain gauge and the fourth strain gauge when viewed along the first hole center axis; the first strain gauge, the second strain gauge, the third strain gauge and the fourth strain gauge are arranged to satisfy a first equation (1) $$\theta 1-\theta 2+\theta 3-\theta 4=-\frac{2}{\left(1+v\right)}\frac{Ip}{I}\frac{L2}{L1}\theta a$$

in a case where: θ1 represents a first angle defined between the longitudinal axis and the first measuring axis when viewed in the axial direction; θ2 represents a second angle defined between the longitudinal axis and the first measuring axis when viewed in the axial direction; θ3 represents a third angle defined between the longitudinal axis and the first measuring axis when viewed in the axial direction; θ4 represents a fourth angle defined between the longitudinal axis and the first measuring axis when viewed in the axial direction; v represents the Poisson's ratio of the material of the crank arm; Ip represents a second polar moment of area of the crank arm; I represents a second moment of area of the crank arm; L1 represents a first distance defined from the center of a reference cross-section to the first strain gauge in the reference cross-section, the reference cross-section being taken along a first reference plane perpendicular to the longitudinal axis; L2 represents a second distance defined from the center of the reference cross-section to the first strain gauge in a direction perpendicular to the first hole center axis and the longitudinal axis; and θa represents an inclination angle defined between the longitudinal axis and a second reference plane perpendicular to the first hole center axis. Crank arm after Claim 1 , wherein the longitudinal axis defines a first region and a second region when viewed in the axial direction, the longitudinal axis being provided between the first region and the second region when viewed in the axial direction, the first strain gauge and the third strain gauge being provided in the first region when viewed in the axial direction, and the second strain gauge and the fourth strain gauge being provided in the second region when viewed in the axial direction. Crank arm after Claim 1 or 2 , wherein a first longitudinal distance is defined in a first direction when viewed in the axial direction between the first strain gauge and the axis of rotation, the first direction being defined to be parallel to the longitudinal axis when viewed in the axial direction, a second longitudinal distance is defined in the first direction when viewed in the axial direction between the second strain gauge and the axis of rotation, and the first longitudinal distance is equal to the second longitudinal distance. The crank arm after Claim 3 , in which a third longitudinal distance when viewed in the axial direction between the third strain gauge and the first hole center axis in the first direction, a fourth longitudinal distance is defined when viewed in the axial direction between the fourth strain gauge and the first hole center axis in the first direction, and the third longitudinal distance is equal to the fourth longitudinal distance. Crank arm according to one of the Claims 1 until 4 , wherein a first perpendicular distance when viewed in the axial direction is defined between the first strain gauge and the longitudinal axis in a second direction, the second direction being perpendicular to the longitudinal axis when viewed in the axial direction, a second perpendicular distance when viewed in the axial direction is defined between the second strain gauge and the longitudinal axis in the second direction, and the first perpendicular distance is equal to the second perpendicular distance. Crank arm after Claim 5 wherein a third vertical distance when viewed in the axial direction is defined between the third strain gauge and the longitudinal axis in the second direction, a fourth vertical distance when viewed along the axis of rotation is defined between the fourth strain gauge and the longitudinal axis in the second direction, and the third vertical distance is equal to the fourth vertical distance. Crank arm according to one of the Claims 1 until 6 , in which a calculation result of the first equation (1) ranges from 3 degrees to 5 degrees. Crank arm according to one of the Claims 1 until 7 wherein the crank arm is free of any strain gauge other than the first strain gauge, the second strain gauge, the third strain gauge, and the fourth strain gauge. Crank arm according to one of the Claims 1 until 8th , further comprising: a first arm end; and a second arm end, wherein the arm body extends between the first arm end and the second arm end along the longitudinal axis, the crank axle mounting hole is provided at the first arm end, the pedal axle mounting hole is provided at the second arm end, the first arm end has a first thickness defined along the first hole center axis and having a first axial center, the second arm end has a second thickness defined along the second hole center axis and having a second axial center, and the longitudinal axis is defined to pass through the first axial center and the second axial center. Crank arm according to one of the Claims 1 until 9 , wherein the arm body includes a mounting surface, the first strain gauge, the second strain gauge, the third strain gauge and the fourth strain gauge are provided on the mounting surface, and the longitudinal axis runs along the mounting surface. Crank arm according to one of the Claims 1 until 10 , further comprising an electronic controller electrically connected to the first strain gauge, the second strain gauge, the third strain gauge and the fourth strain gauge, the electronic controller being configured to calculate a deformation amount of the crank arm based on the first output, the second output, the third output, the fourth output and a second equation (2) $$E=E1-E2+E3-E4$$

in a case where: E represents the deformation amount of the crank arm; E1 represents the first output; E2 represents the second output; E3 represents the third output; and E4 represents the fourth output. Crank assembly comprising: the crank arm according to one of the Claims 1 until 11 ; and a crank axle.

Images