Middle shaft type torque sensor of electric power-assisted bicycle

Abstract

The utility model discloses a center shaft type torque sensor of an electric power-assisted bicycle. The center shaft type torque sensor comprises a center shaft, a PCB support and a rotating assembly composed of a magnetic ring support and a twisting sleeve. The PCB support and the rotating assembly are sequentially arranged on the center shaft in a sleeving mode. A strain gauge is arranged on the surface of the twisting sleeve; a receiving end PCB is arranged on the PCB bracket; external threads or spline teeth are arranged in the middle of the middle shaft, and the twisting sleeve is in transmission connection with the middle shaft through the external threads or the spline teeth; the magnetic ring support is sequentially sleeved with a magnetic ring and an output end coil, and the rear end face of the magnetic ring support is sleeved with an output end PCB connected with a strain gauge circuit. A receiving end coil in electromagnetic induction connection with the output end coil is installed on the PCB support, and the receiving end coil is connected with a receiving end PCB circuit. According to the utility model, the torsion borne by the center shaft is measured through the strain gauges, and the measured torque signal is continuous, real-time and accurate.

Description

TECHNICAL FIELD

[0001] The utility model relates to the manufacturing technology of middle shaft type torque sensor, in particular to a middle shaft type torque sensor of electric power-assisted bicycle. BACKGROUND

[0002] In this era of nationwide fitness and green travel, cycling has been popular among more and more people because of its natural sports ground and aerobic exercise method. Because the infrastructure work in China is very good, the total mileage of the pavement is the first in the world, and the asphalt road conditions are excellent, which makes the cycling in China develop vigorously. As a new type of bicycle, electric power-assisted bicycle can intelligently provide power according to the user's effort, effectively reduce the user's fatigue, and ensure the user's riding experience and safety compared with traditional non-assisted bicycles and pure electric two-wheeled electric vehicles.

[0003] Torque sensor is an element for sensing the user's effort on the electric power-assisted bicycle, and is a crucial part of the entire electric power-assisted bicycle system. As an input end, the accuracy of the torque sensor directly affects the judgment of the controller and the user experience. The commonly used sensors on the market include speed sensors, pseudo torque sensors, and torque sensors. The speed sensor can only sense the speed of the user's pedaling or the speed of the bicycle running, and cannot effectively feedback the user's intention. The pseudo torque sensor simulates the user's effort signal by processing the speed signal, which is better than the speed sensor, but still cannot accurately feedback. The torque sensor measures the size of the user's pedaling force and the pedaling speed (the torque sensor generally includes a speed sensor) when the user rides, and can accurately feedback (the controller adjusts the motor output power according to the torque signal) according to the user's intention (the size of the effort). Torque sensor is being more and more widely accepted by electric power-assisted bicycle system. SUMMARY

[0004] The utility model solves the technical problem of the prior art, and provides a middle shaft type torque sensor of electric power-assisted bicycle, which has simple structure, convenient installation, and can ensure signal transmission continuity and accuracy.

[0005] The utility model adopts the technical scheme for solving the above technical problems:

[0006] The application discloses a middle shaft type torque sensor of an electrically assisted bicycle, which comprises a middle shaft, a PCB board support and a rotating assembly composed of a magnetic ring support and a torsion sleeve; the PCB board support and the rotating assembly are sequentially sleeved on the middle shaft; the surface of the torsion sleeve is provided with strain gauges; the PCB board support is provided with a receiving end PCB connected with an output cable; the middle part of the middle shaft is provided with external threads or spline teeth; the torsion sleeve in the rotating assembly is connected with the middle shaft through the external threads or the spline teeth; the magnetic ring support is mostly inserted into the right end hole of the PCB board support, a magnetic ring and an output end coil are sequentially sleeved on the inserted part, the rear end surface of the magnetic ring support is sleeved with an output end PCB connected with the strain gauge circuit; the PCB board support is provided with a receiving end coil connected with the output end coil through electromagnetic induction, and the receiving end coil is connected with the receiving end PCB circuit.

[0007] In order to optimize the above technical scheme, the specific measures taken also include:

[0008] Three receiving end PCBs are equi-arcuately arranged on the PCB board support, and Hall elements used for cooperation with the magnetic ring measurement are arranged on the receiving end PCBs; a plurality of strain gauges are equi-arcuately arranged on the circumferential surface of the torsion sleeve.

[0009] The PCB board support is sleeved with an outer sleeve, and a magnetic shielding sleeve is sleeved with the output end coil; the outer sleeve and the PCB board support are filled with encapsulation.

[0010] The left end bearing used for rotation support is arranged at the left end of the middle shaft, and the outer periphery of the left end bearing is provided with a left bearing cup used for screwing with the five-way pipe of the bicycle.

[0011] The connecting threads or connecting spline used for connection with the gear plate transmission of the bicycle are arranged at the right end of the torsion sleeve, and the gear plate lock nut used for locking the gear plate is arranged at the right end of the torsion sleeve.

[0012] The right end bearing used for rotation support is arranged at the left side of the connecting threads or connecting spline on the torsion sleeve, and the outer periphery of the right end bearing is provided with a right bearing cup used for screwing with the five-way pipe of the bicycle.

[0013] The special-shaped steel pipe used for protection is sleeved with the left segment part of the torsion sleeve on which the right end bearing is arranged, the left end port of the special-shaped steel pipe covers the output end PCB, and the special-shaped steel pipe, the torsion sleeve and the output end PCB are also filled with encapsulation.

[0014] The first clamping spring used for cooperation with the left end bearing positioning and the second clamping spring used for preventing the axial stringing of the rotating assembly are arranged on the middle shaft; the third clamping spring used for preventing the stringing of the right end bearing is arranged in the right bearing cup.

[0015] The first sealing ring is arranged between the PCB board support and the magnetic ring support, and the second sealing ring is arranged between the torsion sleeve and the middle shaft.

[0016] The wave-shaped gasket is arranged between the left tooth bowl and the left end bearing, and the rubber gasket is press-fitted between the left end bearing and the outer sleeve.

[0017] Compared with the prior art, the utility model discloses a rotating assembly and a PCB board support are sleeved on the middle shaft, the rotating assembly is composed of a magnetic ring support and a torsion sleeve, the torsion sleeve in the rotating assembly is connected with the middle shaft in transmission through external thread or spline tooth, the magnetic ring support is provided with a magnetic ring, an output end coil and an output end PCB, and the PCB board support is provided with a receiving end coil and a receiving end PCB. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 It is the sectional view structure drawing of the utility model;

[0019] Fig. 2 It is the explosion drawing of the utility model;

[0020] Fig. 3 It is the three-dimensional structure schematic diagram of the utility model;

[0021] Fig. 4 It is the assembly schematic diagram of the utility model and electric power-assisted bicycle five-way pipe. DETAILED DESCRIPTION

[0022] The embodiments of the utility model are further described in detail below in combination with the drawings.

[0023] Figs. 1 to 4 It is the structure and assembly schematic diagram of the utility model.

[0024] The reference signs in it are: first sealing ring F1, second sealing ring F2, first clasp spring H1, second clasp spring H2, third clasp spring H3, rubber coating J, tooth disc lock nut M, wave-shaped gasket P1, rubber gasket P2, aluminum gasket P3, left tooth bowl W1, right tooth bowl W2, middle shaft 1, spline tooth 11, PCB board support 2, receiving end PCB 21, receiving end coil 22, magnetic ring support 3, magnetic ring 31, output end coil 32, output end PCB 33, torsion sleeve 4, connecting spline 41, outer sleeve 5, magnetic isolation sleeve 6, special-shaped steel pipe 7, left end bearing 81, right end bearing 82, output cable 9.

[0025] As Figs. 1 to 4As shown in the utility model discloses a kind of middle shaft formula torque sensors of electric power-assisted bicycle, the torque sensor includes middle shaft 1, non-rotating component and rotating component.Non-rotating component mainly includes PCB board support 2 and fixedly installed receiving end PCB 21 and receiving end coil 22 on the PCB board support 2.Rotating component mainly includes magnetic ring support 3 and torsion sleeve 4 connected together and magnetic ring 31, output end coil 32 and output end PCB 33 installed on magnetic ring support 3.PCB board support 2 and magnetic ring support 3 and torsion sleeve 4 in rotating component are successively sleeved on middle shaft 1, and the middle part of middle shaft 1 is provided with external thread or spline tooth 11, and torsion sleeve 4 in rotating component is connected by external thread or spline tooth transmission.Middle shaft 1 can transmit the torsional moment received to torsion sleeve 4 by external thread or spline tooth, and torsion sleeve 4 produces slight deformation under stress.A plurality of strain gauges are pasted on the outer circumferential surface of torsion sleeve 4 with equal radian, and the strain gauges convert the slight deformation into electrical signal line and transmit to output end PCB 33, and output end PCB 33 further transmits the received electrical signal to receiving end coil 22 by output end coil 32 electromagnetically.Receiving end coil 22 further transmits the sensed electrical signal line to receiving end PCB 21, and receiving end PCB 21 further transmits to the outside after processing the received electrical signal by connected output cable 9.The transmission mode of electrical signal of the utility model, when transmitting from rotating component (torsion sleeve 4, magnetic ring support 3, output end PCB 33 and output end coil 22) to non-rotating component (PCB board support 2, receiving end PCB 21 and receiving end coil 22), electromagnetic induction principle is adopted, which can reduce the mechanical wear between accessories, improve the service life of product, and ensure the continuity, real-time and accuracy of signal transmission.

[0026] By Fig. 1 As can be seen, the magnetic ring support 3 of the utility model mostly extends into the right end hole of the PCB board support 2, and the magnetic ring 31 and the output end coil 32 are sleeved on the extended part, and the output end PCB 33 is sleeved on the rear end face of the magnetic ring support 3, and the receiving end coil 22 is installed on the PCB board support 2 and located at the outer periphery of the output end coil 32.The center of the output end coil 32 and the receiving end coil 22 is aligned, and the signal is transmitted non-contactly by electromagnetic induction principle.

[0027] As shown in the embodiment, Fig. 1 Three receiving end PCBs 21 are installed on the PCB board support 2 with equal radian, and the receiving end PCB 21 is provided with a Hall element for cooperation with the magnetic ring 31 measurement.Magnetic ring 31 is provided with 18 to 36 pairs of magnetic poles, and the Hall element detects the rotational speed of the middle shaft 1 by measuring the change of the magnetic pole.

[0028] In the embodiment, the outer sleeve 5 is sleeved on the PCB support 2, and the magnetic isolation sleeve 6 is sleeved on the outer periphery of the receiving end coil 22; the outer sleeve 5 and the PCB support 2 are filled with encapsulation glue. The encapsulation glue can protect the receiving end PCB 21, and the outer sleeve 5, the magnetic isolation sleeve 6 and the PCB support 2 form an integrated body.

[0029] In the embodiment, the left end of the middle shaft 1 is provided with a left end bearing 81 for rotation support, and the outer periphery of the left end bearing 81 is provided with a left cup W1 for screw assembly with the five-way pipe of the bicycle.

[0030] In the embodiment, the right end of the torsion sleeve 4 is provided with a connecting thread or connecting spline 41 for connection with the gear plate transmission of the bicycle, and the right end of the torsion sleeve 4 is provided with a gear plate lock nut M for locking the gear plate.

[0031] In the embodiment, the right end bearing 82 for rotation support is arranged on the left side of the connecting thread or connecting spline 41 of the torsion sleeve 4, and the outer periphery of the right end bearing 82 is provided with a right cup W2 for screw assembly with the five-way pipe of the bicycle. The outer sides of the left cup W1 and the right cup W2 of the utility model are provided with gear teeth and wrench grooves, and the gear teeth are provided with anti-glue for preventing the gear teeth from loosening, and the gear teeth are locked and matched with the five-way thread of the bicycle during use.

[0032] In the embodiment, the special-shaped steel pipe 7 for protection is sleeved on the left segment of the torsion sleeve 2 where the right end bearing 82 is arranged, and the left end port cover of the special-shaped steel pipe 7 covers the output end PCB 33, and the special-shaped steel pipe 7 is also filled with encapsulation glue J between the torsion sleeve 4, the magnetic ring support 3 and the output end PCB 33.

[0033] In the embodiment, the first clamping spring H1 for positioning cooperation with the left end bearing 81 and the second clamping spring H2 for preventing the rotation assembly from axially moving are arranged on the middle shaft 1; the third clamping spring H3 for preventing the right end bearing 82 from moving is arranged in the right cup W2.

[0034] In the embodiment, the first sealing ring F1 is arranged between the PCB support 2 and the magnetic ring support 3, and the second sealing ring F2 is arranged between the torsion sleeve 4 and the middle shaft 1.

[0035] In the embodiment, the wave-shaped gasket P1 is arranged between the left cup W1 and the left end bearing 81, and the rubber pad P2 is press-fitted between the left end bearing 81 and the outer sleeve 5; the aluminum gasket P3 is sleeved on the left cup W1 and the right cup W2.

[0036] The utility model discloses a strain gauge formula principle measures moment of force, and torsion cover links with the middle axle and the tooth disc through the key or the thread respectively, and a plurality of strain gauges are pasted on the torsion cover, when the torsional moment that the middle axle received is transmitted to the tooth disc through the torsion cover, the torsion cover produces trace deformation under the force, and the strain gauge that sets up on the torsion cover will trace deformation into electric signal, and the output end PCB receives the signal through the output end coil and the receiving end coil, and the signal is transmitted to the receiving end PCB, and the receiving end PCB exports after signal processing.

[0037] The best embodiment of the utility model has been illustrated, and various changes or modifications made by those skilled in the art will not deviate from the scope of the utility model.

Claims

1. A center-shaft torque sensor for an electric-assisted bicycle, comprising a center-shaft (1), a PCB board bracket (2), and a rotating assembly consisting of a magnetic ring bracket (3) and a torsion sleeve (4); the PCB board bracket (2) and the rotating assembly are sequentially mounted on the center-shaft (1); strain gauges are provided on the surface of the torsion sleeve (4); a receiving end PCB (21) connected to an output cable (9) is provided on the PCB board bracket (2); characterized in that: The central shaft (1) is provided with an external thread or spline (11) in the middle. The torsion sleeve (4) in the rotating assembly is connected to the central shaft (1) through the external thread or spline transmission. The magnetic ring bracket (3) extends into the right end hole of the PCB board bracket (2). The extended part is fitted with a magnetic ring (31) and an output coil (32) in sequence. The rear end face of the magnetic ring bracket (3) is fitted with an output PCB (33) connected to the strain gauge circuit. The PCB board bracket (2) is equipped with a receiving coil (22) that is electromagnetically connected to the output coil (32). The receiving coil (22) is connected to the receiving PCB (21) circuit.

2. The bottom bracket torque sensor for an electric-assist bicycle according to claim 1, characterized in that: The PCB board support (2) is equipped with three receiving PCBs (21) with equal arcs. The receiving PCBs (21) are provided with Hall elements for cooperation with magnetic ring measurement. The circumferential surface of the torsion sleeve (4) is provided with multiple strain gauges with equal arcs.

3. The bottom bracket torque sensor for an electric-assist bicycle according to claim 2, characterized in that: The PCB board support (2) is fitted with an outer sleeve (5), and a magnetic shielding sleeve (6) is fitted around the outer periphery of the receiving coil (22); the space between the outer sleeve (5) and the PCB board support (2) is filled with adhesive.

4. A bottom bracket torque sensor for an electric-assist bicycle according to claim 3, characterized in that: The left end of the central shaft (1) is positioned and installed with a left end bearing (81) for rotational support. The outer periphery of the left end bearing (81) is provided with a left thread cup (W1) for screw assembly with the bottom bracket of a bicycle.

5. A bottom bracket torque sensor for an electric-assist bicycle according to claim 4, characterized in that: The right end of the torsion sleeve (4) is formed with a connecting thread or connecting spline (41) for connecting with the chainring drive of a bicycle, and the right end of the torsion sleeve (4) is fitted with a chainring lock nut (M) for locking the chainring.

6. A bottom bracket torque sensor for an electric-assist bicycle according to claim 5, characterized in that: The right end bearing (82) for rotational support is positioned and installed on the left side of the connecting thread or connecting spline (41) on the torsion sleeve (4). The outer periphery of the right end bearing (82) is provided with a right threaded cup (W2) for screw assembly with the bottom bracket of a bicycle.

7. A bottom bracket torque sensor for an electric-assist bicycle according to claim 6, characterized in that: The torsion sleeve (4) is fitted with a protective shaped steel tube (7) on the left section of the right end bearing (82) where it is installed. The left end of the shaped steel tube (7) covers the output end PCB (33). The space between the shaped steel tube (7), the torsion sleeve (4), and the output end PCB (33) is also filled with adhesive (J).

8. A bottom bracket torque sensor for an electric-assist bicycle according to claim 7, characterized in that: The central shaft (1) is equipped with a first retaining ring (H1) for positioning and cooperating with the left end bearing (81) and a second retaining ring (H2) for preventing axial movement of the rotating assembly; the right toothed cup (W2) is equipped with a third retaining ring (H3) for preventing movement of the right end bearing (82).

9. A bottom bracket torque sensor for an electric-assist bicycle according to claim 8, characterized in that: A first sealing ring (F1) is installed between the PCB board support (2) and the magnetic ring support (3), and a second sealing ring (F2) is installed between the torsion sleeve (4) and the central shaft (1).

10. A bottom bracket torque sensor for an electric-assist bicycle according to claim 9, characterized in that: A corrugated shim (P1) is provided between the left toothed cup (W1) and the left end bearing (81), and a rubber shim (P2) is press-fitted between the left end bearing (81) and the outer sleeve (5); both the left toothed cup (W1) and the right toothed cup (W2) are fitted with aluminum shims (P3).

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