Power-assisted sensor of electric power-assisted bicycle

Abstract

The utility model relates to the field of power-assisted sensors, and discloses a power-assisted sensor of an electric power-assisted bicycle, which is characterized in that a circuit board is fixed in a mounting groove, two Hall elements are arranged on the circuit board, a crank sleeve is rotatably mounted in a mounting rotating groove, and the crank sleeve comprises a mounting ring seat; an installation outer ring is formed on the protruding part of the surface of the upper end of the installation ring base, a magnetic ring is installed on the surface of the outer ring of the installation outer ring, and fixing pieces used for being fixed to a bicycle crank are arranged on the surface of the inner ring of the installation outer ring and the surface of the inner ring of the installation ring base. Wherein the cross section of the fixing piece is of a regular hexagon structure, the size of the inscribed circle of the fixing piece is not larger than the minimum machining size of the crank, when the crank sleeve is installed on the crank, the crank can enable the six inner edges of the fixing piece to deform to a certain degree and expand outwards, and then the crank sleeve is firmly fixed to the crank. And in the using process, falling cannot occur, and the stability is improved.

Description

Technical Field

[0001] The utility model relates to the field of assist sensors, in particular to an assist sensor for an electric assist bicycle. Background Art

[0002] An assist bicycle uses a battery as an auxiliary power source, is equipped with a motor, and automatically completes the assist acceleration process through the cooperation of an assist sensor and a motor controller. The assist sensor is generally installed on the crank of the bicycle pedal. The crank of the bicycle pedal is a cylindrical structure. When installing, the crank passes through the fixing device inside the assist sensor. The fixing device is a ring structure, and the size of the circular hole inside it matches the size of the crank, and an interference fit is used. The outer diameter size of the same type of bicycle crank is determined. However, there will be certain errors in the processing of the crank, which makes the size of the crank within a certain tolerance range. For some cranks with larger tolerances, when installing (that is, the size of the crank is larger than the rated size or smaller than the rated size), it will be inconvenient to install due to the size being too large or too small. When the size is too large, it is difficult to socket it into the fixing device, and when the size is too small, it is easy to fall off after installation. For this reason, we designed an assist sensor for an electric assist bicycle. Summary of the Utility Model

[0003] To solve the technical problem that the assist sensor is not convenient to install, the utility model provides an assist sensor for an electric assist bicycle.

[0004] The utility model is realized by adopting the following technical solutions: An assist sensor for an electric assist bicycle includes a sensor protection shell. An upper cover is installed above the sensor protection shell through screws. A mounting rotating groove is formed by a recess design at the center inside the sensor protection shell. An installation groove is also provided on the outer ring of the sensor protection shell. A circuit board is fixed in the installation groove. Two Hall elements are arranged on the circuit board, and a single-chip microcomputer is also arranged at the lower end of the circuit board.

[0005] A crank sleeve is rotatably installed in the mounting rotating groove. The crank sleeve includes a mounting ring seat. A mounting outer ring is formed by a protruding part on the upper end surface of the mounting ring seat. A magnetic ring is installed on the outer surface of the mounting outer ring, and fixing parts for fixing with the bicycle crank are arranged on the inner surfaces of both the mounting outer ring and the mounting ring seat.

[0006] As a further improvement of the above solution, a mounting protrusion is formed by a downward protrusion design at the bottom end of the outer part of the sensor protection shell. The mounting protrusion has a cavity design to form a mounting rotating groove. The crank sleeve is placed inside the mounting protrusion. A reinforcing rib is arranged between the outer surface of the mounting protrusion and the sensor protection shell, which is convenient for the installation of the crank sleeve. Moreover, the local height of the sensor protection shell increases, the height of the rest remains unchanged, and the overall thickness also remains unchanged, which improves the strength and reduces the overall size and weight.

[0007] As a further improvement of the above solution, the cross-section of the fixing member is in a hexagonal structure. The outer six corners of the fixing member are connected to the inner ring surfaces of the mounting outer ring and the mounting ring seat and are thickened. The overall thickness of the fixing member is relatively thin. When the crank sleeve is installed on the crank, the crank can cause the six inner sides of the fixing member to deform to a certain extent and expand outwards, so that the crank sleeve is firmly fixed on the crank and will not fall off during use.

[0008] As a further improvement of the above solution, a plurality of equally spaced reinforcing arc blocks are provided on the outer ring surface of the mounting outer ring, and positioning protrusions are formed on the outwardly protruding parts on the left and right sides. A positioning notch is formed by removing a part of the inner ring surface of the magnetic ring. The positioning protrusion is clamped in the positioning notch. The outward side of the reinforcing arc block is in an arc structure, and this arc structure fits the inner ring surface of the magnetic ring, which can quickly install and fix the magnetic ring and enable the magnetic ring to rotate together with the crank sleeve.

[0009] As a further improvement of the above solution, the magnetic ring is made of a neodymium iron boron material, and forty-eight equally spaced magnetic regions are formed by magnetizing the magnetic ring through a magnetizer inside. The two Hall elements are Hall element one and Hall element two respectively, and the included angle between the two Hall elements is not greater than 7.5 degrees. It is set that there is a time difference in the pulse signals formed by Hall element one and Hall element two and the magnetic field on the magnetic ring, that is, one is generated first and the other is generated later, so as to be able to distinguish whether the crank of the bicycle rotates forward or backward, and thus be able to judge whether the user is stepping on the crank forcefully to make the bicycle move forward and needs assistance, or the crank of the bicycle rotates idly and does not need assistance.

[0010] As a further improvement of the above solution, a wire groove is also provided in the sensor protection shell, and a wire is placed in the wire groove. The inner end of the wire is electrically connected to the circuit board. The wire is placed outside through the opening of the sensor protection shell, and the other end of the wire is used to be connected to the drive motor of the bicycle, so as to control the rotation of the drive motor. The overall thickness of the sensor protection shell is relatively thin, and a cavity groove is formed by its internal sinking design. The crank sleeve, the circuit board and the Hall element can all be placed inside.

[0011] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0012] 1. By arranging a fixing member inside the crank sleeve in the present utility model, the cross-section of the fixing member is in a regular hexagonal structure, and the inscribed circle of the fixing member is set to a size not greater than the minimum machining size of the crank. When the crank sleeve is installed on the crank, the crank can cause the six inner sides of the fixing member to deform to a certain extent and expand outwards, so that the crank sleeve is firmly fixed on the crank and will not fall off during use, improving the stability;

[0013] 2. By setting two Hall elements, these two Hall elements can determine the running state of the bicycle, and then can provide corresponding assistance as needed. Moreover, 48 magnetic regions are provided on the magnetic ring, making the magnetic fields on the magnetic ring more dense respectively. And when the crank rotates 7.5 degrees, a pulse signal can be generated, making the moving distance of the crank small and the time to generate the pulse signal shorter, thereby improving the accuracy of the assistance sensor.

[0014] 3. The overall size of the assistance sensor is small, the weight is light, and the strength is large. The overall modular design facilitates the installation and replacement of internal components. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of the overall structure of the assistance sensor for an electric-assisted bicycle provided by the present utility model;

[0016] Figure 2 It is Figure 1 a schematic diagram of the structure without the upper cover in

[0017] Figure 3 It is Figure 2 an exploded view of

[0018] Figure 4 It is Figure 2 a distribution diagram of the magnetic regions of the magnetic ring in

[0019] Figure 5 It is Figure 1 a bottom schematic diagram of

[0020] Main Symbol Explanation:

[0021] 1. Upper cover; 2. Sensor protection shell; 21. Wire groove; 22. Installation rotating groove; 23. Installation groove; 3. Crank sleeve; 31. Installation ring seat; 32. Installation outer ring; 33. Fixing piece; 34. Positioning protrusion; 4. Wire; 5. Magnetic ring; 51. Positioning notch; 52. Magnetic region; 6. Circuit board; 7. Hall element. Detailed Embodiment

[0022] Next, in combination with the drawings and specific embodiments, the present utility model will be further described. It should be noted that on the premise of no conflict, the following described embodiments or technical features can be arbitrarily combined to form new embodiments.

[0023] Embodiment:

[0024] Please combine with Figures 1-5, the assist sensor of the electric assist bicycle in this embodiment includes a sensor protective housing 2. An upper cover 1 is installed above the sensor protective housing 2 by screws. A mounting rotating groove 22 is formed by grooving at the center inside the sensor protective housing 2. An installation groove 23 is also provided on the outer ring of the sensor protective housing 2. A circuit board 6 is fixed in the installation groove 23. Two Hall elements 7 are provided on the circuit board 6, and a single-chip microcomputer is also provided at the lower end of the circuit board 6;

[0025] A crank sleeve 3 is rotatably installed in the mounting rotating groove 22. The crank sleeve 3 includes a mounting ring seat 31. A protruding part on the upper surface of the mounting ring seat 31 forms a mounting outer ring 32. A magnetic ring 5 is installed on the outer surface of the mounting outer ring 32. And fixing parts 33 for fixing with the bicycle crank are provided on the inner surfaces of both the mounting outer ring 32 and the mounting ring seat 31.

[0026] Please combine Figures 2-5 , as an embodiment of the present utility model, the outer bottom end of the sensor protective housing 2 protrudes downward to form a mounting protrusion. The mounting protrusion has a cavity design to form a mounting rotating groove 22. The crank sleeve 3 is placed inside the mounting protrusion. A reinforcing rib is provided between the outer surface of the mounting protrusion and the sensor protective housing 2, which is convenient for the installation of the crank sleeve 3. And the local height of the sensor protective housing 2 increases, while the height of the rest remains unchanged, and the overall thickness also remains unchanged, and the strength is improved, and the overall size and weight are also reduced.

[0027] The cross-section of the fixing part 33 is in a hexagonal structure. The six outer corners of the fixing part 33 are connected to the inner surfaces of the mounting outer ring 32 and the mounting ring seat 31 and are thickened. The overall thickness of the fixing part 33 is relatively thin. The fixing part 33 is made of an elastic material and has a relatively thin thickness. The outer diameter size of the same model of bicycle crank is determined, but there will be certain errors in the processing process, so that the size of the crank is within a certain tolerance range. We set the inscribed circle of the fixing part 33 to a size not greater than the minimum size of the crank processing. When the crank sleeve 3 is installed on the crank, the crank can cause a certain degree of deformation of the six inner sides of the fixing part 33 and expand outward, so that the crank sleeve 3 is firmly fixed on the crank and will not fall off during use.

[0028] A plurality of equally spaced reinforcing arc blocks are provided on the outer surface of the mounting outer ring 32. And positioning protrusions 34 are formed on the protruding parts of the reinforcing arc blocks on the left and right sides. A positioning notch 51 is formed by removing part of the inner surface of the magnetic ring 5. The positioning protrusion 34 is clamped in the positioning notch 51. The outer side of the reinforcing arc block is in an arc structure, and this arc structure fits the inner surface of the magnetic ring 5, which can quickly install and fix the magnetic ring 5 and enable the magnetic ring 5 to rotate together with the crank sleeve 3.

[0029] Please combine Figures 2-4, as an embodiment of the present utility model, the magnetic ring 5 is made of neodymium iron boron material, and forty-eight equally spaced magnetic regions 52 are formed by magnetizing the inside of the magnetic ring 5 through a magnetizer. The two Hall elements 7 are respectively Hall element one and Hall element two, and the included angle between the two Hall elements 7 is not greater than 7.5 degrees. The magnetic regions 52 in the magnetic ring 5 will generate a magnetic field. When the magnetic regions 52 on the magnetic ring 5 pass by the Hall element 7, the carriers on the Hall element 7 will deflect, and then a pulse signal will be generated on the Hall element 7. This pulse signal will be detected by the single-chip microcomputer to drive the drive motor of the electric assist bicycle to work and assist the bicycle. Moreover, it is set that there is a time difference between the pulse signals formed by Hall element one and Hall element two and the magnetic field on the magnetic ring 5, that is, one is generated first and the other is generated later. Thus, it can be determined whether the crank of the bicycle rotates forward or backward, and then it can be judged whether the user is stepping on the crank forcefully to make the bicycle move forward and needs assistance, or whether the crank of the bicycle rotates idly and does not need assistance. And by setting 48 magnetic regions on the magnetic ring 5, the included angle between every two adjacent magnetic regions is 7.5 degrees, which makes the magnetic field on the magnetic ring 5 more dense, and a pulse signal can be generated every time the crank rotates 7.5 degrees, making the moving distance of the crank small and the time for generating the pulse signal shorter, thereby improving the accuracy of the assist sensor.

[0030] Please combine with Figures 2-4 , as an embodiment of the present utility model, a wire groove 21 is further provided inside the sensor protection shell 2, and a wire 4 is placed in the wire groove 21. The inner end of the wire 4 is electrically connected to the circuit board 6. The wire 4 is placed outside through the opening of the sensor protection shell 2, and the other end of the wire 4 is used to connect to the drive motor of the bicycle, so as to control the rotation of the drive motor. The overall thickness of the sensor protection shell 2 is relatively thin, and a cavity is formed by the sunken design inside it. The crank sleeve 3, the circuit board 6 and the Hall element 7 can all be placed inside it, which also makes the overall size small, the weight light and the strength high. The overall modular design is convenient for the installation and replacement of internal components.

[0031] The above embodiments are only the preferred embodiments of the present utility model and cannot be used to limit the scope of protection of the present utility model. Any non-substantial changes and substitutions made by those skilled in the art based on the present utility model belong to the scope of protection required by the present utility model.

Claims

1. An electric power-assisted bicycle power-assist sensor, comprising a sensor protection shell (2), an upper cover (1) being mounted on the sensor protection shell (2) by screws, characterized in that: The recessed groove at the center of the sensor protective shell (2) is designed to form a mounting groove (22), and the outer ring of the sensor protective shell (2) is also provided with a mounting groove (23), a circuit board (6) is fixed in the mounting groove (23), two Hall elements (7) are provided on the circuit board (6), and a single-chip microcomputer is also provided at the lower end of the circuit board (6); A crank sleeve (3) is rotatably mounted in the mounting groove (22), the crank sleeve (3) comprising a mounting ring seat (31), a mounting outer ring (32) is formed on a protruding portion of the upper end surface of the mounting ring seat (31), a magnetic ring (5) is mounted on the outer ring surface of the mounting outer ring (32), and a fixing piece (33) for fixing to a bicycle crank is provided on the inner ring surfaces of the mounting outer ring (32) and the mounting ring seat (31).

2. The electric power-assisted bicycle power-assisting sensor according to claim 1, characterized in that: The outer bottom end of the sensor protective shell (2) is designed to protrude downward to form a mounting protrusion, and the mounting protrusion cavity is designed to form a mounting rotation groove (22). The crank sleeve (3) is placed in the mounting protrusion, and a reinforcing rib is provided between the outer ring surface of the mounting protrusion and the sensor protective shell (2).

3. The power assist sensor for an electric power assist bicycle as claimed in claim 1, characterized in that: The cross section of the fixing member (33) is a hexagonal structure. The six outer corners of the fixing member (33) are connected to the inner ring surface of the mounting outer ring (32) and the mounting ring seat (31) and are thickened. The overall thickness of the fixing member (33) is relatively thin.

4. The power assist sensor for an electric power assist bicycle as claimed in claim 1, characterized in that: The outer ring surface of the mounting outer ring (32) is provided with a plurality of reinforcing arc blocks distributed at equal intervals, and the outwardly protruding portions of the reinforcing arc blocks on the left and right sides are formed with positioning protrusions (34), and the inner ring surface of the magnetic ring (5) is cut away to form a positioning notch (51), and the positioning protrusion (34) is snapped into the positioning notch (51).

5. The power assist sensor for an electric power assist bicycle as claimed in claim 1, characterized in that: The magnetic ring (5) is made of a neodymium iron boron material, and the interior of the magnetic ring (5) is magnetized by a magnetizer to form forty-eight equally spaced magnetic regions (52), and the two Hall elements (7) are Hall element one and Hall element two, respectively, and the angle between the two Hall elements (7) is no greater than 7.5 degrees.

6. The power assist sensor for an electric power assist bicycle as claimed in claim 1, characterized in that: A wire groove (21) is also provided in the sensor protection shell (2), and a wire (4) is placed in the wire groove (21), and the inward end of the wire (4) is electrically connected to the circuit board (6).

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