CN108394511B

CN108394511B - Electronic speed-changing angle sensing structure

Info

Publication number: CN108394511B
Application number: CN201710069227.5A
Authority: CN
Inventors: 母学智; 张桂荣; 简吉明; 张重仁
Original assignee: AD II Engineering Inc
Current assignee: AD II Engineering Inc
Priority date: 2017-02-08
Filing date: 2017-02-08
Publication date: 2020-03-17
Anticipated expiration: 2037-02-08
Also published as: CN108394511A

Abstract

The invention provides an electronic speed-changing angle sensing structure, which comprises a switch unit, a driving unit and a sensing unit. The switch unit has a link mechanism. The driving unit is positioned on the switch unit; the driving unit defines a power transmission path and a non-power transmission path except the power transmission path; the driving unit outputs power along the power transmission path to drive the link mechanism to act, and the driving unit is provided with a worm wheel on the power transmission path. The sensing unit is connected with the driving unit and is positioned on the non-power transmission path; the sensing unit comprises a sensing gear and a sensing assembly, wherein the sensing gear synchronously rotates with the power output shaft, and the sensing assembly detects the rotation angle of the sensing gear.

Description

Electronic speed-changing angle sensing structure

Technical Field

The present invention relates to a derailleur of a bicycle, and more particularly, to an electronic shift angle sensing structure with high resolution.

Background

Since the derailleur usually has a relatively small movement range, in order to more accurately confirm the position of the derailleur in time according to the road conditions, the electrical control accuracy of the derailleur in the bicycle industry is more and more required, for example, in taiwan patent application No. I247711, "electric derailleur for bicycle", a digital sensor is directly arranged on the output shaft of the motor 21, but the driving force directly generated by the output shaft of the motor 21 still needs to output a real driving force through the reduction gear assembly 22, and then the moving position of the derailleur is calculated by the real driving force. In other words, the relationship between the output power of the motor 21 and the real driving force is the speed reduction relationship, the absolute position from the output power of the motor 21 to the moving position of the derailleur needs to be specifically converted rather than directly measured, and the required number of rotations and angle of the derailleur are both lower than the number of rotations and angle detected by the digital sensor, so that the reduction gear assembly 22 does more work, and not only wear is easily generated, but also the number of rotations and angle converted by the speed reduction is lower in resolution.

U.S. patent application No. US5480356 "Speed Change Device for cycles" provides a motor 21 incorporating a reduction gear to drive the screw and an encoder 32 to detect the rotational angle of the screw, however, this design will only make the difference between each step about 7-8 degrees, which is relatively expensive to manufacture compared to the need to select a detector with small tolerance and high precision.

Chinese patent application No. CN100372730C, "gear reduction apparatus for bicycle component", is to integrate a reduction mechanism and a position sensor into a single device for easy disassembly and maintenance, and also does not provide any significant ink for improving resolution.

Therefore, it is highly desirable to provide an angle sensing structure with high precision and low cost.

Disclosure of Invention

The invention aims to provide an electronic speed change angle sensing structure which can give consideration to both high precision and low cost.

Therefore, the present invention provides an electronic speed-changing angle sensing structure, which comprises a switch unit, a driving unit and a sensing unit. The switch unit has a link mechanism. The driving unit is arranged on the switch unit; the driving unit defines a power transmission path and outputs power along the power transmission path to drive the connecting rod mechanism to move; the driving unit at least comprises a power output shaft on the power transmission path. The sensing unit is connected to the driving unit and is positioned outside the power transmission path; the sensing unit comprises a sensing gear and a sensing assembly, wherein the sensing gear and the sensing assembly synchronously rotate with the power output shaft, and the sensing assembly is used for detecting the rotation angle of the sensing gear.

Through the structure, the sensing unit is arranged outside the power transmission path, so that the resolution can be further improved, the chance of reducing abrasion is reduced, the cost is considered, and the effects of rapid speed change and accurate fine adjustment are achieved.

Drawings

FIG. 1 is a perspective view of an electronic shift angle sensing structure of the present invention;

FIG. 2 is an exploded perspective view of the electronic shift angle sensing structure of the present invention;

FIG. 3 is a schematic view of the driving unit and the sensing unit in FIG. 2 from another angle; and

FIG. 4 is a block diagram of an electronic shift angle sensing structure according to the present invention.

[ notation ] to show

Switch unit 10

Base 11 link mechanism 12

Drive unit 20

Motor 21 reduction gear assembly 22

Worm 23 and worm wheel 24

Power take-off shaft 25

Power transmission path P1 non-power transmission path P2

Sensing unit 30

Sensing gear 31 sensing assembly 32

Angle sensor 321 count sensor 322

Control element 33

Detailed Description

Fig. 1 to 4 show an electronic gearshift angle sensing structure according to the present invention, which includes a switch unit 10, a driving unit 20 disposed on the switch unit 10, and a sensing unit 30 connected to the driving unit 20.

The switch unit 10 at least includes a base 11 and a connecting rod mechanism 12, which is a transmission structure of the current bicycle transmission, please refer to fig. 1 and 4. The driving unit 20 defines a power transmission path P1 and a non-power transmission path P2 other than the power transmission path P1; the driving unit 20 outputs power along the power transmission path P1 to move the link mechanism 12 relative to the base 11.

The driving unit 20 includes at least a motor 21, a reduction gear assembly 22, a worm 23 driven by the reduction gear assembly 22, a worm wheel 24 (i.e., a driving wheel) engaged with the worm 23, and a power output shaft 25 integrated with the worm wheel 24 to rotate synchronously on a power transmission path P1.

The sensing unit 30 is located outside the power transmission path P1. For the definition of the present invention, the paths formed by the power transmission members other than the power transmission path P1 may be defined as non-power transmission paths, and the aforementioned defined non-power transmission path P2 is merely an example. Accordingly, the sensing unit 30 can be specifically described as being located on the non-power transmission path P2. Obviously, the sensing unit 30 is located outside the reduction gear assembly 22.

Referring to fig. 2 to 4, the sensing unit 30 includes a sensing gear 31 (i.e., a driven wheel) engaged with the worm wheel 24 of the driving unit 20, a sensing element 32 connected to the sensing gear 31, and a control element 33 (only shown in fig. 4) electrically connected to the sensing element 32. The sensing gear 31 and the worm 23 are respectively provided at opposite sides of the worm wheel 24. The axis of the worm 23 is orthogonal to the axis of the worm wheel 24, and the axis of the sensing gear 31 is parallel to the axis of the power output shaft 25, so that the sensing gear 31 is provided on the non-power transmission path P2 without interfering with the power transmission path P1.

As shown in fig. 4, the sensing assembly 32 may further include an angle sensor 321 and a counting sensor 322; the control unit 33 detects the rotation angle δ of the sensing gear 31 by the angle sensor 321, detects the number N of rotations of the sensing gear 31 by the count sensor 322, and feeds back the rotation angle δ and the number N to the driving unit 20.

In the foregoing embodiment, the diameter of the sensing gear 31 is smaller than that of the worm wheel 24, so that the sensing gear 31 directly rotates along with the worm wheel 24 and has a higher rotation speed ratio, such as 3:1, thereby improving the resolution and accuracy of angle sensing and reducing the chance of abrasion of the reduction gear assembly 22

It should be noted that the sensing gear 31 can be set to coincide with the rotation angle of the worm wheel 24 (i.e., the power output shaft 25), so that the rotation angle δ and the number N of rotations detected by the angle sensor 321 and the counter sensor 322 are the same as the power output shaft 25, and therefore, the conversion of the rotation speed reduction is not required. In addition, the electronic speed change angle sensing structure of the invention does not need to consider the design factor of the reduction gear assembly 22 any more, and further avoids the cost trouble that a high-precision sensor is needed in the reduction gear assembly 22.

It is emphasized that the sensor assembly 32 employed in the foregoing embodiments is merely illustrative and does not limit the type of sensor to which the present invention is applied, nor is it necessary to use both an angle sensor and a counting sensor, but a single sensor may be used as the angle assembly of the present invention.

In summary, the sensing unit 30 of the electronic speed-changing angle sensing structure of the present invention is disposed at a position other than the power transmission path P1, so that the sensing unit has a higher resolution, and at the same time, the probability of wear of the reduction gear assembly 22 is reduced, and the requirement of using a high-precision sensor is eliminated, so that the cost is considered, and the effects of rapid speed change and precise fine adjustment are achieved.

The present invention and its embodiments are not limited to the above examples, but the concept may be replaced or changed within the concept and scope of the claims.

Claims

1. An electronic speed-change angle sensing structure, comprising:

a switching unit having a link mechanism;

a driving unit arranged on the switch unit; the driving unit defines a power transmission path which is formed by a motor, a reduction gear assembly, a worm and a worm wheel which are meshed with each other in sequence, and outputs power to a power output shaft along the power transmission path, and the power output shaft drives the connecting rod mechanism to act; and

the sensing unit is connected to the driving unit and is positioned outside the power transmission path; the sensing unit comprises a sensing gear and a sensing component, wherein the sensing gear synchronously rotates with the power output shaft, and the sensing component is used for detecting the rotation angle of the sensing gear;

wherein, this worm is driven to rotate by this reduction gear subassembly, and this power output shaft and this worm wheel integration are as an organic whole, and this worm wheel drives this sensing gear and rotates.

2. The electronic shift angle sensing structure as defined in claim 1, wherein: the axis of the sensing gear is parallel to the axis of the power output shaft.

3. The electronic shift angle sensing structure as defined in claim 1, wherein: the sensing gear has a higher rotational speed than the power take-off shaft.

4. The electronic shift angle sensing structure as defined in claim 3, wherein: the rotation speed ratio of the sensing gear to the power output shaft is 3: 1.

5. The electronic shift angle sensing structure as defined in claim 1, wherein: the rotational speed of the sensing gear is equal to the power take-off shaft.

6. The electronic shift angle sensing structure as defined in claim 1, wherein: the sensing assembly comprises an angle sensor, a counting sensor and a control element electrically connected with the angle sensor and the counting sensor; the control element detects the rotation angle of the sensing gear by the angle sensor, detects the revolution number of the sensing gear by the counting sensor, and feeds back the rotation angle and the revolution number to the driving unit.