Electric assist bicycle torque measurement device capable of detecting pedaling torque at two ends of crank shaft

Abstract

The invention provides an electric assist bicycle torque measurement device capable of detecting pedaling torque at two ends of a crank shaft. The pedaling torque and motor power are connected to a hollow shaft sleeved on the crank shaft by corresponding one-way transmission devices and are transmitted to a transmission sprocket. A torque detection unit is arranged on the hollow shaft and positioned between a first one-way transmission device and a second one-way transmission device. Therefore, the power transmission of a middle motor and the power transmission of pedals do not affect each other. When the torque detection unit senses a pedaling torque value higher than a set pedaling torque value, the middle motor can provide appropriate electric assist power to reduce the detected torquevalue to the set pedaling torque value. The electric assist bicycle torque measurement device allows an entire middle electric assist system to be small in size, and allows the pedaling torque controlto be simple and not affected by the external environment.

Description

technical field [0001] The invention relates to a torque detection device for an electric bicycle that can detect the pedaling torque at both ends of the crankshaft. The pedaling torque and motor power of the invention are both connected to a hollow shaft sleeved outside the crankshaft through a corresponding one-way transmission device. and transmitted to the transmission sprocket; the torque detection unit is located on the hollow shaft and is located between the first one-way transmission device and the second one-way transmission device; The power transmission does not affect each other, and the torque detection unit can accurately measure the torque transmitted by the left and right ends of the crankshaft; accordingly, when the torque detection unit senses a value higher than the set pedaling torque, it can make The mid-mounted motor provides appropriate electric assistance to reduce the detected torque value to the set pedaling torque value. Background technique [00...

AI Technical Summary

Problems solved by technology

[0004] However, the existing pedal shaft does not have a hollow shaft, but if a torque detection unit is directly arranged on the pedal shaft, the torque detection unit will only be able to sense the torque at one end of the pedal shaft. Pedal torque; if you want to sense the pedal torque at both ends of the pedal shaft, you must install torque detection units on both sides of the chain plate, which will lead to high overall volume and installation costs

[0005] And another existing pedal shaft is provided with a hollow shaft, which is to install a torque detection unit on the hollow shaft. When it is combined with the power transmission of the mid-mounted motor, if the aforementioned dual If there is a one-way transmission device, the power transmission between the mid-mounted motor and the pedal will affect each other; if there is only a one-way transmission device between the pedal shaft and the hollow shaft, the pedal torque will be affected by the hysteresis force of the motor; if only the motor power There is a one-way transmission device between the transmission and the hollow shaft. When the motor rotates, it will force the pedal shaft to rotate synchronously, which will cause uncomfortable riding

[0006] And in another existing pedal shaft, although it is provided with a hollow shaft outside the pedal shaft, the torque detection unit is not located on the hollow shaft, such as the sprocket disc, chain, and rear frame of an electric vehicle. ;According to this design, when the torque detection unit senses a value higher than the set pedaling torque, and the mid-mounted motor provides electric assistance, the detected torque value will not decrease but increase, which will cause the torque control of the electric bicycle errors and difficulties

In addition, its sensor is exposed, which will be easily damaged by the outside or weather or affect its sensing results

[0007] Existing such as the "BICYCLE WITH AUXILIARY POWERUNIT" case of U.S. Patent Publication No. 20120048634, its pedal crankshaft 38 is provided with a hollow sleeve 72, and directly connects with the sprocket disc 36; A rotating shaft 108 and a sprocket 60; the sprocket disc 36 and the sprocket discs 60 and 62 are connected by a chain 44; the power transmission of the motor in this design is not directly combined with the hollow shaft as in the ideal design above, and the entire center The size of the electric assist system is complex but not small; in terms of power transmission, there are two more sprocket discs 60, 62, which will also increase the energy loss of the transmission system

[0008] Existing " torsion sensing device for electric bicycle " patent such as China Taiwan Patent Certificate No. M451316, although it is provided with the driven sleeve (hollow shaft) that is sleeved on the crankshaft, detection unit, one-way clutch and big plate, but its Not combined with a mid-mounted motor; obviously, the design will only be used in front-drive and rear-drive e-bikes

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