JP3214826U - Torque detection device for electric assist bicycle - Google Patents

Abstract

To provide a torque detection device for an electrically assisted bicycle that accurately detects the magnitude of human power output torque and accurately controls matching between the electric assist and the magnitude of the output torque of human power. An attachment part that can be fixed to a vehicle body 1 of an electrically assisted bicycle, and a torque sensing device installed on the attachment part. The torque sensing device includes a sensor elastic body 6 arranged vertically, a deformation sensor capable of detecting deformation of the sensor elastic body is installed in the sensor elastic body, a sensing sprocket 7 is installed in the sensor elastic body, and the sensing sprocket is a transmission chain. 4 is engaged with the tension part 41, and the tension part is formed with a V-shaped curved part at the position of the sensing sprocket. An electrical signal corresponding to the amount of deformation is output. [Selection] Figure 1

Description

  The present invention relates to the technical field of a power-assisted bicycle, and more particularly to a detection device that can accurately detect the magnitude of pedaling force when a person rides on a bicycle.

  At present, electric bicycles equipped with a storage battery and a hub motor are widely used in China due to advantages such as labor saving and convenience. However, the conventional electric bicycle has the following problems. The electric bicycle takes charge of the pedal, which makes it easy for a person who rides the bicycle to maneuver, but the pedal and the hub motor as the power source can be controlled separately. In other words, a person riding a bicycle can directly control the rotation speed of the hub motor by an electric switch installed on the steering wheel of the vehicle, thereby driving the vehicle march completely with electric power. In this way, it is difficult for a person riding a bicycle to smoothly control the electric switch in the electric driving state, so that the electric power assist drive and the pedal depression drive cannot be satisfactorily cooperated, and thereby the pure electric power drive is achieved. Only the mode can be used, and pedaling cannot be used unless the electricity stored in the battery is exhausted. The traveling method has the advantage of being quick and labor-saving, but it is likely to cause speeding and may cause a danger of traveling. Also, it cannot meet the demand that some users train their bodies by running with human power.

  Therefore, an electric assist bicycle is provided, and the basic structure and operation principle of the electric assist bicycle is similar to that of the electric bicycle, which also drives the hub motor by the storage battery, thereby driving the vehicle. However, the control of the rotation speed of the hub motor is controlled by a signal detected by the corresponding sensor, and when the controller receives a signal such as the pedal speed, torque, or vehicle state output from the sensor, The operating state and output torque can be automatically controlled. In other words, a person riding a bicycle can not realize pure power drive without adopting pedaling travel, and power drive can be used only for auxiliary drive, thereby effectively limiting the traveling speed of the vehicle. And at the same time achieve the goal of labor saving.

  For example, in the “electrically assisted vehicle control method and system” disclosed in Patent Document 1, the method detects the marching speed of the electrically assisted vehicle by a speed sensor, detects the traveling state of the electrically assisted vehicle by a level, When starting to ride on an assist vehicle, the marching speed is greater than zero, and if the traveling state of the electrically assisted vehicle is a horizontal traveling state at this time, the electrically assisted vehicle is simply driven by a torsional force acting on the pedal by human power, and the vehicle Record the rotation speed or torsional force value of the pedal in the horizontal running state. If the driving state of the electrically assisted vehicle is an uphill driving state, the drive motor is activated and rotated forward to form auxiliary power, whereby the pedal achieves the rotational speed or torsional force value in the horizontal driving state. . That is, when the vehicle climbs the hill, the torsional force value output by the person riding on the bicycle by stepping on the pedal and the traveling speed of the vehicle are kept in agreement with the speed during horizontal traveling. If the traveling state of the electrically assisted vehicle is a downhill traveling state, the inertia of the vehicle drives the reverse rotation of the drive motor to generate electric power, thereby charging the mobile power source.

  Although the above invention has the advantage of automatically controlling the driving mode of the vehicle according to the actual driving state, the following defects still exist. First, the vehicle cannot achieve electric assist when it is in a horizontal running state within most of the time. That is, the main reason for determining whether or not assistance is required is the vehicle driving state signal obtained by the level, and therefore the assist effect is not clear. Second, in general situations, people have a high running speed when driving horizontally, and correspondingly lower the running speed when going uphill, thereby overloading the mobile power supply and hub motor to its service life It is desirable to avoid affecting. However, in the above invention, the control system of the output torque at the time of the electric assist is not rational, and it controls not the magnitude of the output torque but the traveling speed of the vehicle, which is advantageous for the simplification of the control system. However, it is easy to cause the problem that the output torque at the time of the electric assist is excessive. In particular, when the slope of the uphill is very large or the load on the vehicle is large, it causes overload operation of the mobile power supply and the hub motor, thereby seriously affecting its service life.

  Further, in the above invention, there is a description of a concept of detecting the pedal torque by directly installing the torque sensor 1 on the pedal. However, the conventional torque sensor generates a corresponding output electric signal mainly by deformation after receiving the torque, and the pedal receives a limited torque when the vehicle is driven. That is, the amount of deformation is very small, which makes it difficult for the torque sensor to detect it accurately, and if a highly accurate torque sensor is used, the manufacturing cost of the entire vehicle is greatly increased.

Chinese Patent Application No. 1062875858

  The purpose of the present invention is to solve the problem that it is difficult to accurately control the output torque of the electric assist based on the magnitude of the torque that the electric assist vehicle adopting chain transmission has been output manually. The torque detection device for the vehicle is capable of accurately detecting the output torque of the human-powered traveling, whereby the controller accurately controls the output torque of the electric assist, and the output torque of the electric assist and the output of the human power Matching the magnitude of the torque, ensuring that the rider can easily control the speed of the vehicle according to the subjective will of the person, saving labor and achieving a good training effect.

  In order to achieve the above object, the present invention uses the following technical solutions. A torque detection device for an electrically assisted bicycle, comprising: an attachment part that can be fixed to a vehicle body of the electrically assisted bicycle; and a torque sensing device that is installed on the attachment part, wherein the torque sensing device is installed on the attachment part and vertically A deformation sensor capable of detecting deformation of the sensor elastic body is installed on the sensor elastic body, a sensing sprocket is installed on the sensor elastic body, and the sensing sprocket is a tension portion of the transmission chain of the electrically assisted bicycle. The transmission chain tension part is formed with a V-shaped curved part where it comes into contact with the sensing sprocket, and a tension mechanism is installed at the loose part of the transmission chain to give the transmission chain an initial tension. The part is stretched and the sensing sp When push socket, sensor elastic body to generate a deformation, deformation sensor at this time can output an electrical signal corresponding to the amount of deformation of the sensor an elastic body.

  In the prior art, there is a means to control the output torque of the drive motor by detecting the torque of the pedal and chainring, but all the sensors for detecting the conventional torque measure the deformation of the parts. Therefore, the pedal and the chainring itself have a rigid structure. Therefore, the amount of deformation of pedals and chainrings when a bicycle rider rides on a bicycle is extremely small, and correspondingly, the accuracy of the electrical signal output from it is limited or the cost is extremely high. Must be used. Therefore, people can generally only determine whether the vehicle is in a running state by the above sensor, and correspondingly output torque of the drive motor based on the magnitude of pedal or chainring torque when riding. I can't control it. In the present invention, by installing a sensing sprocket that presses against the tension portion of the transmission chain, a V-shaped curved portion is formed where the tension portion contacts the sensing sprocket. Thus, when a bicycle rider starts riding, the pedal drives the forward rotation of the chain ring, and at this time, the tension portion of the transmission chain is tensioned and tensioned, thereby forming a V-shaped curved portion. Pushing the sensing sprocket that is located, and further causing deformation in the sensor elastic body, the deformation sensor in the sensor elastic body can output the corresponding electrical signal, and the drive motor can respond to the corresponding torque based on the magnitude of the electrical signal Is output. As can be appreciated, with reasonable material selection and structural design, the sensor elastic body can have sufficient elasticity so that the sensor elastic body can generate a sufficiently large deformation when starting to ride on the vehicle. In other words, the present invention indirectly obtains the output torque of manual driving by detecting the degree of tension of the transmission chain, thereby easily realizing matching between the output torque of the drive motor and the output torque of manual driving. be able to. In particular, the sensor elastic body installed in the mounting part can easily form a structure similar to a cantilever, so that the sensing sprocket can generate a large curved deformation when pushed to the transmission chain, It is advantageous for the controller to accurately control the output torque of the drive motor. The tension mechanism can give a stable initial tension to the transmission chain, thereby ensuring the stability of the electric signal output from the deformation sensor.

  Preferably, one end of the sensor elastic body is fixed to a mounting part, and the sensing sprocket is installed at the other end of the sensor elastic body, whereby the sensor elastic body has a cantilever shape, and the sensing sprocket has a tension portion. Engage with the upper side.

  The sensor elastic body has a cantilever shape, and the sensing sprocket is installed at the hanging end of the sensor elastic body, so that the sensing sprocket installed at the hanging end of the sensor elastic body is mounted on the sensor elastic body when getting on the vehicle. As much as possible, the bending deformation can be generated, and the control signal output from the deformation sensor can accurately control the output torque of the drive motor.

  Preferably, the sensing sprocket is installed at one end of the sensor elastic body, a guide sprocket is installed at the other end of the sensor elastic body, and the sensing sprocket and the guide sprocket are respectively positioned on both sides of the tension portion of the transmission chain of the electrically assisted bicycle. The sensing sprocket and the guide sprocket are engaged with the tension portions, respectively, and the tension portion of the transmission chain is formed with a Z-shaped curved portion after the guide sprocket and the sensing sprocket are wound sequentially.

  Sensing sprockets and guide sprockets that press against the transmission chain are installed on both the upper and lower sides of the tension portion of the transmission chain, whereby the tension portion forms a Z-shaped curved portion at the sensing sprocket. Thus, when a bicycle rider starts riding, the pedal drives the forward rotation of the chainring, and at this time the tension of the transmission chain is tensioned and thereby pushes the guide sprocket and sensing sprocket. Further, the sensor elastic body is bent and deformed, the deformation sensor in the sensor elastic body can output a corresponding electric signal, and the drive motor outputs a corresponding torque based on the magnitude of the electric signal. By rationally designing the relative position between the guide sprocket and the sensing sprocket, the Z-shaped curved part formed by the transmission chain at the location of the sensing sprocket has a sufficient depression angle, so that the tension part is sensing Sufficient push force is generated against the sprocket.

  Preferably, the mounting part includes a vertically arranged support stand, and the sensor elastic body is fixed to an upper portion of the support stand and fixed to a lower portion of the support stand between a chain ring and a ratchet of the electric assist bicycle. A disassembled hoop that can be connected to the fork is installed.

  The disassembling hoop facilitates the connection and mounting between the support stand and the body fork, and the vertically installed support stand is not only advantageous for reducing the mounting space, but it is mainly axial when riding on the vehicle Can also be subjected to tension or pressure along. Therefore, the strength and rigidity can be remarkably improved.

  Preferably, the attachment part includes an attachment plate disposed horizontally, one end of the sensor elastic body is fixed to one side of the attachment plate, and an ellipse shape that can be connected to the body of the electric assist bicycle on the other side of the attachment plate A screw hole is provided, a downwardly inclined curved portion is provided at the other end of the sensor elastic body, the sensing sprocket is provided at the end of the curved portion, and the sensing sprocket is engaged with the upper side of the tension portion of the transmission chain.

  The horizontally arranged mounting plate is advantageous for placement and attachment in the vehicle body of the present invention, and the downwardly inclined curved portion is advantageous for opening the pitch between the sensor elastic body and the transmission chain. , Avoid interference and friction between the two when getting on the vehicle.

  Preferably, the mounting part includes a vertical support stand arranged at two front and rear intervals, the front and rear ends of the sensor elastic body are respectively fixed to the two front and rear support stands, and the sensing sprocket has sensor elasticity. A guide sprocket that is installed in the middle of the body, meshes with the tension of the transmission chain at the top of the support stand, and can be connected to and fixed to the fork between the chain ring and the ratchet of the power-assisted bicycle at the bottom of the support stand A separate disassembled hoop is installed, and the guide sprocket and sensing sprocket are located on both sides of the tension part of the transmission chain.

  In this aspect, two guide sprockets are installed on the side of the transmission chain facing the sensing sprocket, thereby forming a character-shaped arrangement with the three sprockets. The transmission chain can form a V-shaped curved portion that is fixed when the guide sprocket, the sensing sprocket and the guide sprocket are sequentially wound. By adjusting the relative position of the three sprockets, the transmission chain can form a deep V-shaped bend, thereby creating a greater push force against the sensing sprocket with the same transmission chain tension, and The push force received by the sensing sprocket is ensured to be related only to the transmission chain tension, i.e., the torque of the chain ring, and is applied to the electrical signal output by the angle sensor due to external factors such as the relative distance between the chain ring and the ratchet. Avoid influence and interference.

  Preferably, the deformation sensor is a resistance strain gauge that is in close contact with the surface of the sensor elastic body, thereby easily detecting the bending deformation of the sensor elastic body.

  Preferably, the tension mechanism includes a tension rocker whose one end is rotatably installed on the vehicle body, a tension sprocket that meshes with a loose portion is installed on the other end of the tension rocker, a tension spring is installed on the tension rocker, The spring drives the swinging of the tension rocker, whereby the tension sprocket is pressed against the slack portion.

  The tension spring may be a torsion spring or a tension spring, and the tension sprocket can be meshed with the inside of the loosened portion, whereby an inherent tension is formed in the transmission chain, and the length of the transmission chain, etc. Avoid changes in output signal due to changes.

  Therefore, the present invention has the following beneficial effects. It is possible to accurately detect the magnitude of the manpower output torque when riding an electric assist bicycle, thereby accurately controlling the matching between the output torque of the electric assist and the manpower output torque. It ensures that the rider can easily control the speed of the vehicle according to his / her subjective will and achieves a good training effect as well as labor saving.

It is the schematic of the 1st structure of this invention. It is the schematic of the 2nd structure of this invention. It is the schematic of the connection structure of a support stand and a vehicle body. It is the schematic of the 3rd structure of this invention. It is the schematic of the connection structure of a sensor elastic body and a mounting plate. It is the schematic of the 4th structure of this invention.

  The present invention will be further described below with reference to the drawings and embodiments for carrying out the invention.

  As shown in FIG. 1, a torque detection device for an electrically assisted bicycle, which is suitable for detecting a human power output torque of an electrically assisted bicycle when a person riding a bicycle travels by stepping on a pedal, thereby Control the output torque accurately. The power-assisted bicycle here includes a vehicle body 1, a chain ring 2 and a ratchet 3 installed on the vehicle body, and a transmission chain 4 wound around the chain ring and the ratchet, and an upper portion located between the chain ring and the ratchet in the transmission chain. Is a tension part 41, a lower part is a slack part 42, and the chain ring is connected to the pedal 22 by the crank 21. The electric assist bicycle further includes a drive motor that can provide auxiliary power, a controller that can control the operation state and output torque of the drive motor, and a storage battery that supplies power to the drive motor.

  The present invention includes a torque sensing device and a mounting part used for mounting the torque sensing device, and the mounting part can be fixed to a vehicle body of an electrically assisted bicycle. In order to easily detect the manpower output torque, the torque sensing device includes a rod-shaped sensor elastic body 6 installed on the mounting part, the sensor elastic body is disposed vertically along the front and rear, and the sensor elastic body has sensor elasticity. A deformation sensor capable of detecting body deformation is installed. Preferably, the deformation sensor is a resistance strain gauge that is in close contact with the surface of the sensor elastic body. Further, it is necessary to further install the sensing sprocket 7 on the sensor elastic body, and the sensing sprocket is pressed against the tension portion of the transmission chain and meshed with the tension portion of the transmission chain, whereby the tension portion of the transmission chain is connected to the sensing sprocket. A V-shaped curved portion is formed at the contact point.

  In this way, when the chain ring drives the forward rotation of the ratchet by the transmission chain, the tension portion of the transmission chain is stretched to push the sensing sprocket, thereby causing the sensor elastic body to bend and deform. The sensor can output a corresponding electrical signal, and the controller controls the operation of the drive motor and outputs a corresponding assist torque after receiving the signal output by the deformation sensor. It can be understood that when a person riding a bicycle or a bicycle rider tries to improve the traveling speed, the manual torque output by the pedal by the bicycle rider is correspondingly improved, and at this time the tension of the tension part of the transmission chain is Correspondingly, the push force received by the sensing sprocket is increased, the amount of bending deformation of the sensor elastic body is correspondingly increased, the electrical signal output from the deformation sensor is increased, and the controller is operated by the drive motor. Control to output a larger assist torque. By rationally selecting the structural parameters such as the material and length of the sensor elastic body, the sensor elastic body can have sufficient elasticity, so that the sensor elastic body undergoes a sufficiently large deformation when starting to ride on the vehicle. Can be generated. In other words, the present invention indirectly obtains the output torque of manual driving by detecting the degree of tension of the transmission chain, and can easily realize the matching between the output torque of the driving motor and the output torque of manual driving. it can.

  In order to ensure the stability of the electrical signal output from the deformation sensor, a tension mechanism can be installed at the slack portion of the transmission chain. Specifically, the tension mechanism includes a tension locker 11 and a rotation shaft is installed on the vehicle body. One end of the tension locker is rotatably installed on the rotation shaft of the vehicle body and meshes with the hanging end of the tension rocker inside the loose portion. Tension sprocket 9 is installed, tension spring is installed on the tension rocker, and the tension spring drives the rocker of the tension rocker, so that the tension sprocket pushes the loosened part outward and is stable to the entire transmission chain. Maintain initial tension. During manual running, the tension of the tension portion of the transmission chain is improved by manual torque, and at this time, the deformation sensor can output a stable electrical signal. As a matter of course, the tension spring may be a torsion spring fitted to the rotating shaft, and one end of the torsion spring is hooked on the tension rocker and the other end is hooked on the vehicle body. Alternatively, the tension spring may be a tension spring, and one end of the tension spring is connected to the tension rocker and the other end is connected to the vehicle body.

  In order to be advantageous in detecting the bending deformation of the sensor elastic body, one end of the sensor elastic body is fixed to a mounting part, and the other end of the sensor elastic body is suspended, whereby the sensor elastic body has a cantilever shape. Can do. The sensing sprocket is installed at the suspended end of the sensor elastic body, and the sensing sprocket meshes with the upper side of the tension portion. Thus, when riding a vehicle, the sensing sprocket installed at the suspended end of the sensor elastic body can cause the sensor elastic body to bend as much as possible, so that the control signal output by the deformation sensor is The output torque of the drive motor can be accurately controlled.

  Preferably, as shown in FIG. 2, the sensing sprocket is installed at one end of the sensor elastic body, the guide sprocket 8 is installed at the other end of the sensor elastic body, and the guide sprocket and the sensing sprocket are positioned on the same side of the sensor elastic body. To do. The guide sprocket and the sensing sprocket are located on the upper and lower sides of the transmission chain tension part, the sensing sprocket is pressed against the transmission chain tension part, and meshed with the transmission chain tension part, and the guide sprocket is the tension of the transmission chain. The transmission chain is engaged with the tension portion of the transmission chain, and the transmission chain tension portion forms a Z-shaped curved portion after winding the guide sprocket and the sensing sprocket sequentially. As described above, when the chain ring drives the forward rotation of the ratchet by the transmission chain, the tension portion of the transmission chain is stretched to push the guide sprocket and the sensing sprocket, thereby generating a curved deformation in the sensor elastic body. The deformation sensor at this time can output a corresponding electric signal, and the controller controls the operation of the drive motor and outputs the corresponding assist torque after receiving the signal output from the deformation sensor.

  In order to increase the strength and rigidity of the mounting part, the mounting part may be a support stand 50 arranged vertically, the sensor elastic body being fixed to the upper part of the support stand by screws and the lower part of the support stand A disassembly-type hoop 51 is arranged in FIG. Specifically, as shown in FIG. 3, the disassembling hoop includes a semicircular groove installed in the lower part of the support stand, abuts the lower part of the support stand, and is connected to the clamp plate 511 with a screw. A semicircular groove corresponding to the semicircular groove of the stand is installed. Thus, the cylindrical fork located between the chain ring and the ratchet in the vehicle body is engaged in the semicircular groove at the lower part of the support stand, and then the clamp plate abuts the lower part of the support stand. Are simultaneously engaged in a semicircular groove in the clamping plate. Subsequently, the clamp plate can be tightly secured to the support stand with screws, allowing the fork to be securely clamped and positioned in the semicircular groove, thereby securing the support stand orthogonal to the fork. When riding a vehicle, the support stand is primarily subjected to axial tension or pressure. Therefore, the strength and rigidity can be remarkably improved.

  Naturally, as shown in FIGS. 4 and 5, the mounting part may use a horizontally mounted mounting plate 52, and one end of the sensor elastic body is fixed to one side of the mounting plate by a screw, and the mounting plate Two oblong screw holes 521 on the front and rear sides are provided on the other side. In this way, we can fix the mounting plate to the body of the electrically assisted bicycle with screws installed in the oval screw holes, and the oval screw holes facilitate the adjustment of the mounting plate position. Preferably, the bending portion 61 inclined downward is installed at the suspended end of the sensor elastic body, and the sensing sprocket can be installed at the end of the bending portion. In this way, when the sensing sprocket meshes with the upper side of the transmission chain tension, a sufficient pitch can be formed between the sensor elastic body and the transmission chain, avoiding interference and friction between the two when riding on the vehicle. .

  As is well known, when riding on a vehicle, the transmission chain tension portions on both the front and rear sides of the sensing sprocket each have a tilting tension, and the resultant force of the push on the sensing sprocket is formed by the two front and rear tensions. The inclination angle of the tension part on both sides of the sensing sprocket changes as the sensing sprocket mounting position changes, so the electrical signal output from the resistance strain gauge changes with the same human power output torque, and the controller drive motor output torque It is not advantageous to control to. Therefore, as shown in FIG. 6, the attachment part may be a support stand arranged at two intervals on the front and rear sides, and the two support stands are arranged vertically. The front end of the sensor elastic body is fixed to the front support stand, the rear end of the sensor elastic body is fixed to the rear support stand, the sensing sprocket is installed at the middle position of the sensor elastic body, and the sensing sprocket is below the tension part. Engage side. In addition, a guide sprocket 8 that meshes with the upper side of the tension portion of the transmission chain is installed at the upper part of each support stand, and a fork that is connected and fixed between the chain ring and the ratchet of the electric assist bicycle at the lower part of the support stand. The two disassembled hoops are installed, and the two guide sprockets and sensing sprockets are positioned on both the upper and lower sides of the tension portion of the transmission chain, thereby forming an inverted-shaped array.

  When the transmission chain is wound around the first guide sprocket, the sensing sprocket and the second guide sprocket sequentially, the transmission chain is formed with a V-shaped curved portion projecting at a position contacting the sensing sprocket, and the V-shaped curved The part has a fixed depression angle. By adjusting the relative positions of the three sprockets, a deep V-shaped curved portion can be formed in the transmission chain. At this time, the depression angle defined for the V-shaped curved portion is small, thereby forming a larger downward push force on the sensing sprocket with the same transmission chain tension, thereby causing deformation in the sensor elastic body and causing resistance strain. The gauge can output a corresponding electrical signal, and the push force received by the sensing sprocket is only related to the transmission chain tension, i.e. the chainring torque, and external factors such as the relative distance between the chainring and the ratchet Avoid interference and interference with the electrical signal output by the angle sensor.

DESCRIPTION OF SYMBOLS 1 Car body 11 Tension rocker 2 Chain ring 21 Crank 22 Pedal 3 Ratchet 4 Transmission chain 41 Tension part 42 Loose part 50 Support stand 51 Removable hoop 511 Clamp plate 52 Mounting plate 521 Oval screw hole 6 Sensor elastic body 61 Curved part 7 Sensing sprocket 8 Guide sprocket 9 Tension sprocket

Claims (8)

In the torque detection device for an electric assist bicycle including an attachment part that can be fixed to the body of the electric assist bicycle and a torque sensing device attached to the attachment part,
The torque sensing device includes a sensor elastic body that is installed on a mounting part and is arranged vertically, a deformation sensor that can detect deformation of the sensor elastic body is installed on the sensor elastic body, and a sensing sprocket is installed on the sensor elastic body. The sensing sprocket meshes with the tension part of the transmission chain of the power-assisted bicycle, and the transmission chain tension part has a V-shaped curved part where it comes into contact with the sensing sprocket. When the tension mechanism of the transmission chain is installed and the sensing sprocket is pushed by the tension of the transmission chain, the sensor elastic body is deformed. At this time, the deformation sensor is an electric signal corresponding to the deformation amount of the sensor elastic body. It is possible to output ,
Torque detection device for electric assist bicycles. One end of the sensor elastic body is fixed to a mounting part, and the sensing sprocket is installed at the other end of the sensor elastic body, whereby the sensor elastic body has a cantilever shape, and the sensing sprocket meshes with the upper side of the tension portion. It is characterized by
The torque detection device for an electrically assisted bicycle according to claim 1. The sensing sprocket is installed at one end of the sensor elastic body, and a guide sprocket is installed at the other end of the sensor elastic body. The guide sprocket meshes with the tension part, and the tension part of the transmission chain is formed with a Z-shaped curved part after winding the guide sprocket and the sensing sprocket sequentially,
The torque detection device for an electrically assisted bicycle according to claim 1. The mounting part includes a vertically arranged support stand, and the sensor elastic body is fixed to an upper part of the support stand and connected to a fork fixed between a chain ring and a ratchet of an electric assist bicycle at a lower part of the support stand. A possible disassembly type hoop is installed,
The torque detection device for an electrically assisted bicycle according to any one of claims 1 to 3. The mounting part includes a mounting plate arranged horizontally, one end of the sensor elastic body is fixed to one side of the mounting plate, and an oval screw hole that can be connected to the body of the electric assist bicycle is provided on the other side of the mounting plate. Installed, a curved portion inclined downward is installed at the other end of the sensor elastic body, the sensing sprocket is installed at the end of the curved portion, and the sensing sprocket meshes with the upper side of the tension portion of the transmission chain. ,
The torque detection device for an electrically assisted bicycle according to any one of claims 1 to 3. The mounting part includes a vertical support stand arranged at two intervals in the front and rear, the front and rear ends of the sensor elastic body are fixed to the two front and rear support stands, respectively, and the sensing sprocket is positioned between the sensor elastic bodies. The guide sprocket that is installed at the position and meshes with the tension part of the transmission chain is installed at the upper part of the support stand, and it can be connected to the fork between the chain ring and the ratchet of the electric assist bicycle and fixed at the lower part of the support stand A hoop is installed, and the guide sprocket and the sensing sprocket are respectively located on both sides of the tension portion of the transmission chain.
The torque detection device for an electrically assisted bicycle according to claim 1. The deformation sensor is a resistance strain gauge that is in close contact with the surface of a sensor elastic body,
The torque detection device for an electrically assisted bicycle according to any one of claims 1 to 3 or 6. The tension mechanism includes a tension rocker that is rotatably installed at one end on the vehicle body, a tension sprocket that engages with a loose portion is installed at the other end of the tension rocker, a tension spring is installed on the tension rocker, and the tension spring is a tension spring. The rocker is driven to swing, so that the tension sprocket is pressed against the loose part,
The torque detection device for an electrically assisted bicycle according to any one of claims 1 to 3 or 6.

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