CN211995983U - Pedal force sensing mechanism of electric bicycle - Google Patents

Abstract

The utility model discloses an electric bicycle's pedal force sensing mechanism, it includes a crank axle, an axle sleeve, one or more sensing unit and a the control unit. The shaft sleeve is sleeved on the crankshaft and performs unidirectional transmission with the crankshaft by using an isolator, the sensing units are arranged on the shaft sleeve at equal intervals and are used for sensing the torque of the shaft sleeve and respectively and correspondingly generating a plurality of sensing signals, and the control unit is electrically connected with the sensing units and is used for receiving the sensing signals of the sensing units and calculating the average value of the torque corresponding to the sensing signals, so that the control unit controls the motor to output the corresponding assistance according to the average value. Therefore, the utility model discloses an adopt the mode of average value, make sensing unit's mounted position can not receive the restriction to increase installation convenience and promote the sensing precision.

Description

Pedal force sensing mechanism of electric bicycle

Technical Field

The utility model relates to an electric bicycle is related to the field, especially relates to an electric bicycle's power of stepping sensing mechanism.

Background

In order to reduce the burden on the rider, a sensor is usually mounted on the crank shaft of a typical electric bicycle, and a controller controls the magnitude of the boosting force provided by the boosting motor according to the sensed result by sensing a change in a value of the crank shaft, such as a rotational speed or a torque.

The method disclosed in the chinese publication No. M453843 is mainly to attach a bending moment strain gauge and a torque strain gauge to the center of a crankshaft at a predetermined angle to sense the strain generated when the crankshaft is subjected to bending moment and torque, and further determine pedal force signals at the left and right ends of the crankshaft. However, in the above patent documents, the bending moment strain gauge and the torque strain gauge are individually sensed, and there is still a need for improvement in accuracy.

The method disclosed in the chinese publication No. I564214 is mainly to use the strain generated by the axial force applied to the girder by the strain gauges to detect the strain as the torque sensing value between the crank shaft and the toothed disc, so as to improve the torque sensing accuracy. However, in the above patent document, the process of attaching a plurality of strain gauges to the girder is rather inconvenient.

SUMMERY OF THE UTILITY MODEL

A primary object of the present invention is to provide a pedaling force sensing mechanism for an electric bicycle, which can increase the convenience of installation and improve the sensing precision.

In order to achieve the above objective, the pedal force sensing mechanism of the first embodiment of the present invention includes a crank shaft, a shaft sleeve, an isolator, a plurality of sensing units, and a control unit. The shaft sleeve is rotatably sleeved on the crankshaft; the isolator is arranged between the crankshaft and the shaft sleeve and is used for providing a one-way transmission effect; the sensing units are arranged on the shaft sleeve in an equally spaced mode and used for sensing the torque of the shaft sleeve and respectively generating a sensing signal correspondingly; the control unit is electrically connected with the sensing units and used for receiving the sensing signals of the sensing units and calculating the average value of the torque corresponding to the sensing signals, so that the control unit controls the motor to output the corresponding assistance force according to the average value.

Preferably, each sensing unit is a strain gauge and is directly attached to the outer circumferential surface of the shaft sleeve.

In order to achieve the above objective, a pedal force sensing mechanism according to a second embodiment of the present invention includes a crank shaft, a shaft sleeve, an isolator, a sensing unit, and a control unit. The shaft sleeve is made of magnetized material and is sleeved on the crankshaft in a rotatable way; the isolator is arranged between the crankshaft and the shaft sleeve and is used for providing a one-way transmission effect; the sensing units are annularly arranged on the shaft sleeve at equal intervals and used for sensing the torque of the shaft sleeve and correspondingly generating a plurality of sensing signals; the control unit is electrically connected with the sensing unit and used for receiving the sensing signals of the sensing unit and calculating the average value of the torque corresponding to the sensing signals, so that the control unit controls the motor to output the corresponding assistance according to the average value.

Preferably, the sensing unit has a mounting base and a plurality of sensors, the mounting base has a ring portion and two sensing portions, the ring portion has a sleeve hole sleeved on the shaft sleeve, the two sensing portions protrude from one side surface of the ring portion and are located at two opposite sides of the sleeve hole, each sensing portion has a containing groove, and at least one sensor and one control unit are arranged in each containing groove. Through the technical characteristics, the two sensors can deduce the relative position between the two sensors and the shaft sleeve, so as to further obtain the torque generated by the shaft sleeve, and the two control units can control the motor to output corresponding assistance force.

Therefore, the pedal force sensing mechanism of the present invention can prevent the installation position of the sensing unit from being restricted by the average value, thereby increasing the installation convenience and improving the sensing accuracy.

The detailed structure, characteristics, assembly or use of the pedaling force sensing mechanism of the electric bicycle provided by the present invention will be described in the following detailed description of the embodiments. However, those of ordinary skill in the art should understand that the detailed description and specific examples are given for the purpose of illustration only, and are not intended to limit the scope of the invention.

Drawings

Fig. 1 is a perspective view of a pedal force sensing mechanism according to a first embodiment of the present invention;

fig. 2 is a partially exploded perspective view of the pedal force sensing mechanism according to the first embodiment of the present invention;

fig. 3 is a sectional view of the pedaling force sensing mechanism according to the first embodiment of the present invention;

FIG. 4 is a perspective view showing the appearance of the pedal force sensor mechanism of the first embodiment of the present invention in use with a motor;

FIG. 5 is a sectional view showing the pedal force sensing mechanism of the first embodiment of the present invention in use with a motor;

fig. 6 is a perspective view of a pedaling force sensing mechanism according to a second embodiment of the present invention;

fig. 7 is a partial perspective exploded view of a pedal force sensing mechanism according to a second embodiment of the present invention;

fig. 8 is a partial sectional view of a pedal force sensing mechanism according to a second embodiment of the present invention.

Description of the symbols:

10: pedal force sensing mechanism

12: pedal force sensing mechanism

20: crank shaft

30: shaft sleeve

32: first ring tooth part

34: second ring gear part

36: measured portion

38: sleeve ring part

40: sensing unit

42: control unit

50: motor with a stator having a stator core

51: shell body

52: speed reducer

53: transmission gear

54: isolator

55: isolator

60: sensing unit

61: mounting seat

62: ring part

63: sensing part

64: containing groove

65: sensor device

66: control unit

70: shaft sleeve

71: measured portion

Detailed Description

Applicants first describe herein, throughout this specification and in the claims that follow, the terms "comprises" and "comprising" are used in the appended claims to refer to the same or like parts. Next, in the embodiments and the drawings to be described below, the same element numbers denote the same or similar elements or structural features thereof.

Referring to fig. 1 and 2, the pedal force sensing mechanism 10 according to the first embodiment of the present invention is disposed in a housing 51 and includes a crank shaft 20, a shaft sleeve 30, an isolator 54, two sensing units 40, and a control unit 42.

The left and right ends of the crank axle 20 protrude out of the housing 51 (as shown in fig. 4) and are assembled with a pedal (not shown) via a crank arm (not shown), respectively, such that the crank axle 20 can be driven by the left and right pedals to rotate.

The sleeve 30 is coaxially sleeved on the crankshaft. The shaft sleeve 30 has a first annular tooth portion 32, a second annular tooth portion 34, a tested portion 36 and a sleeve portion 38 in sequence from left to right, wherein the first annular tooth portion 32 is used for assembling with a big toothed disc (not shown) so that the shaft sleeve 30 and the big toothed disc can synchronously move, and the second annular tooth portion 34 is used for assembling with a transmission gear 53 so that the shaft sleeve 30 can be driven by the transmission gear 53.

The isolator 54 is disposed in the collar portion 38 of the sleeve 30 and connected to the crankshaft 20, as shown in fig. 5, so that the crankshaft 20 can drive the sleeve 30 to rotate when the pedaling force is applied, but the sleeve 30 cannot drive the crankshaft 20 when the pedaling force is applied in the reverse direction.

Both sensing units 40 are strain gauges in the present embodiment. As shown in fig. 2 and 3, the two sensing units 40 are attached to the measured portion 36 of the shaft sleeve 30 and are disposed at an angle of 180 degrees with respect to the axis of the crankshaft 20, so as to sense the torque generated when the shaft sleeve 30 is subjected to the pedaling force transmitted from the crankshaft 20, and respectively generate a sensing signal.

The control unit 42 is sleeved on the shaft sleeve 30 and electrically connected to the two sensing units 40, and is configured to receive the sensing signals of the two sensing units 40, calculate an average value of torques corresponding to the two sensing signals, and further control the motor 50 to output a corresponding assistance force.

As described above, when the motor 50 is driven, as shown in fig. 5, the motor 50 drives the transmission gear 53 through the speed reducer 52, and then the shaft sleeve 30 is driven by the transmission gear 53, so as to provide the auxiliary power. However, when the motor 50 is not driven, even though the sleeve 30 is driven to rotate, the rotation of the sleeve 30 is not fed back to the motor 50 through the reducer 52 by the isolator 55, so as to avoid damage to the motor 50.

The pedaling force sensing mechanism 12 of the second embodiment of the present invention provides another way to sense the torque of the shaft sleeve 70. As shown in fig. 6 and 7, the sensing unit 60 has a mounting base 61 and four sensors 65, the mounting base 61 has a ring portion 62 and two sensing portions 63, the ring portion 62 is sleeved on the detected portion 71 of the shaft sleeve 70, and the two sensing portions 63 protrude from one side of the ring portion 62 and are located on two opposite sides of the detected portion 71 of the shaft sleeve 70. As shown in fig. 8, each of the sensing portions 63 has one receiving groove 64, and two sensors 65 are disposed in each of the receiving grooves 64. The sleeve 70 is made of a magnetized material, and the relative position between the sleeve 70 and the sleeve 70 can be estimated by the arrangement of the sensors 65, so that the torque generated when the sleeve 70 is subjected to the pedaling force applied by the rider can be obtained, and the control unit 66 controls the motor 50 to output the corresponding assisting force according to the average value of the torque.

It should be noted that, in order to more accurately sense the pedaling force transmitted from the crankshaft 20 to the bushing 30 via the isolator 54, the number of the sensing units 40 or the sensors 65 may be adjusted according to the actual application, as long as they are arranged at equal intervals, for example, three sensors are spaced by 120 degrees, and if four sensors are spaced by 90 degrees, and so on.

To sum up, the utility model discloses a pedaling force sensing mechanism 10, 12 through the mode of taking the average value, make two sensing unit 40 and a plurality of sensor 60's mounted position as long as be separated by 180 degrees can, so can reduce the restriction in the use by a wide margin, and then reach the purpose that increases the convenience of use and promote the sensing precision.

Claims (4)

1. A pedal force sensing mechanism for an electric bicycle, comprising:

a crank shaft;

a shaft sleeve rotatably sleeved on the crank shaft;

an isolator between the crankshaft and the sleeve to allow the crankshaft to rotate in one direction relative to the sleeve;

the sensing units are arranged on the outer peripheral surface of the shaft sleeve and are arranged at equal intervals, are used for sensing the torque of the shaft sleeve and respectively and correspondingly generate a sensing signal; and

and the control unit is electrically connected with the sensing units and used for receiving the sensing signals of the sensing units and calculating the average value of the torque corresponding to the sensing signals.

2. The pedaling force sensing mechanism for an electric bicycle according to claim 1, wherein each of the sensing units is a strain gauge and is attached to an outer circumferential surface of the bushing.

3. A pedal force sensing mechanism for an electric bicycle, comprising:

a crank shaft;

a shaft sleeve rotatably sleeved on the crankshaft, wherein the shaft sleeve is made of magnetized materials;

an isolator between the crankshaft and the sleeve to allow the crankshaft to rotate in one direction relative to the sleeve;

the sensing unit is annularly arranged on the shaft sleeve at equal intervals and used for sensing the torque of the shaft sleeve and correspondingly generating a plurality of sensing signals; and

and the control unit is electrically connected with the sensing unit and used for receiving the sensing signals of the sensing unit and calculating the average value of the torque corresponding to the sensing signals.

4. The pedaling force sensing mechanism of an electric bicycle according to claim 3, wherein the sensing unit comprises a mounting base and a plurality of sensors, the mounting base comprises a ring portion and two sensing portions, the ring portion is sleeved on the shaft sleeve, the two sensing portions protrude from one side surface of the ring portion and are located at two opposite sides of the shaft sleeve, each sensing portion comprises a receiving slot, and at least one sensor is disposed in each receiving slot.

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