A torque sensor and mounting structure for a power-assisted bicycle

Abstract

The present invention discloses a torque sensor and an installation structure for an assisted bicycle, including a shaft body, a strain gauge, a gear, and a cylinder body. Among them, the shaft body is embedded in the bottom bracket, one end of the shaft body is rotatably arranged in the cylinder body by means of a bearing, and the other end of the shaft body is provided with a second stepped groove for installing an inner transmission component. The gear is rotatably arranged in the cylinder body by means of a bearing and is at one end close to the second stepped groove. A through groove and a third stepped groove are formed in the middle of the gear. The through groove is for the shaft body to pass through, and the third stepped groove is for installing an outer transmission component. The inner transmission component and the outer transmission component cooperate with each other so that when the shaft body rotates clockwise, the gear can be driven to rotate. When the runner rotates clockwise, the shaft body can remain stationary. A groove body is formed at one end of the shaft body away from the gear for embedding the strain gauge.

Description

Technical Field

[0001] The present invention relates to the technical field of torque sensors for assisted bicycles, and specifically to a torque sensor for an assisted bicycle and an installation structure thereof. Background Art

[0002] A torque sensor is one of the important components of an assisted bicycle. It can sense the riding environment of the rider, such as riding with the wind, against the wind, uphill, downhill, etc. By transmitting the sensed data to the controller, the motor can be reasonably controlled to participate in the driving process. However, existing torque sensors often adopt a mid-mounted structure, that is, the torque sensor is placed in the bottom bracket of the assisted bicycle. At this time, the strain gauge is installed on the gear, and the torque situation is determined by the slight deformation of the gear. However, the gear is often driven by both the motor and human power, and both will affect the gear, resulting in a more complex torque sensing situation. Moreover, in the prior art, a wireless transmission device is often used to realize the transmission of signals such as those of the strain gauge, and its stability is generally average.

[0003] Therefore, it is necessary to provide a torque sensor for an assisted bicycle and an installation structure thereof to solve the problems raised in the above background art. Summary of the Invention

[0004] To achieve the above object, the present invention provides the following technical solution: A torque sensor for an assisted bicycle, comprising a shaft body, a strain gauge, a gear, and a cylinder body. Among them, one end of the shaft body is rotatably arranged in the cylinder body by a bearing, and the other end of the shaft body is provided with a second stepped groove for installing an inner transmission component. The gear is rotatably arranged in the cylinder body by a bearing and is close to one end of the second stepped groove. A through groove and a third stepped groove are formed in the middle of the gear. The through groove is for the shaft body to pass through, and the third stepped groove is for installing an outer transmission component. The inner transmission component and the outer transmission component cooperate with each other so that when the shaft body rotates clockwise, the gear can be driven to rotate. When the gear rotates clockwise, the shaft body can remain stationary. A groove is formed at one end of the shaft body away from the gear for embedding the strain gauge.

[0005] Further, as a preference, a first stepped groove is formed in the middle of the shaft body for accommodating an electrical connection component. The electrical connection component includes a mounting frame, a conductive block, a first wire, a second wire, and a conductive ring. Among them, the mounting frame is fixedly embedded in the cylinder body, and a plurality of conductive blocks are fixed on the mounting frame. At least two conductive blocks are connected to the first wire, and at least two conductive blocks are connected to the second wire;

[0006] A plurality of conductive rings are fixed on the shaft body, and the number of conductive rings is equal to the sum of the number of the first wires and the number of the second wires;

[0007] The guide ring corresponding to the first wire is electrically connected to the strain gauge by a third wire;

[0008] The guide ring corresponding to the second wire is electrically connected to the strain gauge by a fourth wire;

[0009] It further includes an integrated cable, in which a fifth wire and a sixth wire are arranged. Among them, the fifth wire is electrically connected to the conductive block corresponding to the first wire, and the sixth wire is connected to the conductive block corresponding to the second wire.

[0010] Further, as a preference, an installation ring is embedded between the guide ring and the shaft body, and adjacent guide rings are separated by a spacer ring. Both the installation ring and the spacer ring are made of non-conductive materials.

[0011] Further, as a preference, the first wire, the third wire, and the fifth wire are used for power transmission, and the second wire, the fourth wire, and the sixth wire are used for signal transmission.

[0012] Further, as a preference, a V-shaped ring groove is formed on the surface of the guide ring.

[0013] Further, as a preference, a first bevel gear is coaxially fixed on one side of the gear. The first bevel gear is respectively rotatably connected to the shaft body and the cylinder body by bearings. The first bevel gear and the second bevel gear are meshed at 90°, and the second bevel gear is rotatably arranged in the cylinder body by a bearing and is driven by an external motor.

[0014] Further, as a preference, a ring body is coaxially fixed on the shaft body. Counting strips are fixed on the outer peripheral side of the ring body. A counter is fixed on the inner wall of the cylinder body. It further includes a controller. The controller jointly controls the driving force of the external motor on the gear according to the feedback of the counter and the feedback of the strain gauge. And when the counter feeds back that the rotation speed of the shaft body is greater than the speed threshold, and the strain gauge feeds back that the torque is less than the stress threshold, at this time the controller controls the external motor to reduce the driving force on the gear.

[0015] Further, as a preference, the inner transmission component is a ratchet wheel, and the ratchet wheel is coaxially fixed on the shaft body

[0016] The outer transmission component includes an installation ring. A plurality of limiting grooves are evenly arranged in the circumferential direction on the inner side of the installation ring. Pawls are hinged in the limiting grooves. The middle part of the pawl is connected to the installation ring by a spring.

[0017] A torque sensor installation structure is used to install a torque sensor in the bottom bracket of an assisted bicycle. A ring gasket is fixed on the outer surface of the cylinder body. A first sealing plate is arranged between the gear and the first bevel gear. The first sealing plate can be threadedly connected to the bottom bracket. A second sealing plate is arranged on the side of the shaft body away from the gear. The second sealing plate can be threadedly connected to the bottom bracket.

[0018] An extension cylinder is embedded at the bottom of the five-way joint. The motor has a motor shaft, and a centering cylinder is provided at a position of the motor close to the motor shaft. The centering cylinder can be threadedly connected to the extension cylinder. A square groove is formed at the bottom of the second bevel gear, and the end of the motor shaft has a square head.

[0019] Compared with the prior art, the present invention provides a torque sensor for a power-assisted bicycle and an installation structure, having the following beneficial effects:

[0020] In the present invention, the strain gauge is arranged on the shaft body. Moreover, the inner transmission component and the outer transmission component cooperate with each other so that when the external motor drives the gear to rotate, it will not affect the shaft body. At this time, the strain gauge will not be affected. When the foot pedals the pedal to drive the shaft body to rotate, the gear can be driven to rotate. At this time, the strain gauge will detect a slight deformation of the shaft body, thereby accurately determining the torque.

[0021] In the present invention, an electrical connection component is provided, which can stably supply power and transmit data for the strain gauge.

[0022] In the present invention, the motor for power assistance can be directly installed below the cylinder body, improving the installation efficiency and the driving efficiency. At the same time, the installation of the motor can also realize the positioning of the shaft body. Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of a torque sensor for a power-assisted bicycle;

[0024] Figure 2 It is a schematic installation diagram of a torque sensor for a power-assisted bicycle;

[0025] Figure 3 It is Figure 1 an enlarged schematic diagram of part A of

[0026] Figure 4 It is a schematic structural diagram of the inner transmission component and the outer transmission component in a torque sensor for a power-assisted bicycle;

[0027] In the figure: 1, shaft body; 101, first stepped groove; 102, second stepped groove; 3, strain gauge; 4, gear; 5, cylinder body; 6, ring body; 7, electrical connection component; 8, inner transmission component; 9, outer transmission component; 10, counting bar; 11, counter; 12, first sealing plate; 13, first bevel gear; 14, second bevel gear; 15, gear groove; 16, five-way joint; 17, extension cylinder; 18, motor; 19, motor shaft; 20, ring gasket; 21, second sealing plate; 71, mounting bracket; 72, conductive block; 73, first wire; 74, second wire; 75, guide ring; 76, spacer ring; 77, mounting ring; 91, mounting ring; 92, pawl; 93, spring. Detailed implementation mode

[0028] Example 1: Please refer to Figures 1 to 4 In the embodiment of the present invention, a torque sensor for a power-assisted bicycle includes a shaft body 1, a strain gauge 3, a gear 4, and a cylinder body 5. Wherein, one end of the shaft body 1 is rotatably arranged in the cylinder body 5 by means of a bearing, and the other end of the shaft body 1 is provided with a second stepped groove 102 for installing an internal transmission component 8. The gear 4 is rotatably arranged in the cylinder body 5 by means of a bearing and is close to one end of the second stepped groove 102. A through groove and a third stepped groove are provided in the middle of the gear 4. The through groove is for the shaft body 1 to pass through, and the third stepped groove is for installing an external transmission component 9. The internal transmission component 8 and the external transmission component 9 cooperate with each other so that when the shaft body 1 rotates clockwise, the gear 4 can be driven to rotate. When the gear 4 rotates clockwise, the shaft body 1 can remain stationary. A groove is provided at one end of the shaft body 1 away from the gear 4 for embedding the strain gauge 3.

[0029] In this embodiment, the strain gauge 3 is arranged on the shaft body 1, and the internal transmission component 8 and the external transmission component 9 cooperate with each other so that when the gear 4 rotates clockwise (viewed from the right side to the left side of the shaft body), the shaft body 1 can remain stationary. That is, when the external motor drives the gear to rotate, it will not affect the shaft body, and at this time, the strain gauge 3 will not be affected. When the pedal is stepped on to drive the shaft body to rotate, the gear 4 can be driven to rotate. At this time, the strain gauge will detect a slight deformation of the shaft body, so as to determine the torque.

[0030] To ensure the effective power supply and data transmission for the strain gauge, a first stepped groove 101 is provided in the middle of the shaft body 1 for accommodating the electrical connection component 7. The first stepped groove 101 can provide a space for the installation of the electrical connection component 7 and limit its position, improving the installation efficiency and stability.

[0031] The electrical connection component 7 includes a mounting bracket 71, a conductive block 72, a first wire 73, a second wire 74, and a conducting ring 75. Wherein, the mounting bracket 71 is fixedly embedded in the cylinder body 5, and a plurality of conductive blocks 72 are fixed on the mounting bracket 71. At least two conductive blocks are connected to the first wire 73, and at least two conductive blocks are connected to the second wire 74;

[0032] A plurality of conducting rings 75 are fixed on the shaft body 1, and the number of the conducting rings 75 is equal to the sum of the number of the first wires and the number of the second wires;

[0033] The conducting ring 75 corresponding to the first wire 73 is electrically connected to the strain gauge 3 by a third wire;

[0034] The conducting ring 75 corresponding to the second wire 74 is electrically connected to the strain gauge 3 by a fourth wire;

[0035] It further includes an integrated cable in which a fifth wire and a sixth wire are provided. Among them, the fifth wire is electrically connected to the conductive block 72 corresponding to the first wire 73, and the sixth wire is connected to the conductive block 72 corresponding to the second wire 74.

[0036] It should be noted that in this embodiment, the guide ring 75 is a ring structure, and its outer surface can continuously contact the first wire 73 and the second wire 74, so as to realize the transmission of electricity and signals during the relative rotation process.

[0037] In addition, an installation ring 77 is embedded between the guide ring 75 and the shaft body 1, and adjacent guide rings 75 are separated by a spacer ring 76. Both the installation ring and the spacer ring are made of non-conductive materials.

[0038] In addition, the first wire, the third wire, and the fifth wire are used for power transmission, and the second wire, the fourth wire, and the sixth wire are used for signal transmission.

[0039] In addition, a V-shaped ring groove is formed on the surface of the guide ring 75, so as to effectively limit the first wire and the second wire and ensure their contact quality.

[0040] In this embodiment, a first bevel gear 13 is coaxially fixed on one side of the gear 4. The first bevel gear 13 is respectively rotatably connected to the shaft body 1 and the cylinder body 5 by bearings. The first bevel gear 13 and the second bevel gear 14 are meshed at 90°. The second bevel gear 14 is rotatably arranged in the cylinder body 5 by a bearing and is driven by an external motor 18. That is to say, in this embodiment, the motor for boosting can be directly installed below the cylinder body 5, which improves the installation efficiency and the driving efficiency.

[0041] In this embodiment, a ring body 6 is coaxially fixed on the shaft body 1. A counting strip 10 is fixed on the outer peripheral side of the ring body 6. A counter 11 is fixed on the inner wall of the cylinder body 5. It further includes a controller. The controller jointly controls the driving force of the external motor on the gear 4 according to the feedback of the counter and the feedback of the strain gauge. And when the counter feedback shows that the rotation speed of the shaft body 1 is greater than the rotation speed threshold, and the strain gauge feedback shows that the torque is less than the stress threshold, at this time, the controller controls the external motor to reduce the driving force on the gear 4.

[0042] It needs to be explained that when the counter feedbacks that the rotation speed of shaft body 1 is greater than the rotation speed threshold, it means that the rotation speed of shaft body 1 is faster. When the strain gauge feedback torque is less than the stress threshold, it means that pedaling is almost effortless. At this time, two situations will occur. In the first case, the rider rides normally and drives shaft body 1 to rotate clockwise. At this time, it is mainly driven by the motor, and the rotation speed of the driving gear is too fast. At this time, the controller controls the external motor to reduce the driving force for gear 4. In the second case, the rider subjectively wants the controller to control the external motor to reduce the driving force for gear 4. At this time, the rider reciprocates to drive shaft body 1 to rotate alternately clockwise and counterclockwise in a small range. The counting bar is frequently counted in a short time, thereby forcing the counter feedback shaft body 1 rotation speed to be greater than the speed threshold. At this time, the controller controls the external motor to reduce the driving force for gear 4.

[0043] It should also be noted that the relative position of the counting bar and the foot pedal can be determined during installation, so that the position of the counting bar can be judged from the foot pedal.

[0044] In this embodiment, Figure 4 The inner transmission component 8 is a ratchet, which is coaxially fixed on the shaft body 1.

[0045] The outer transmission assembly 9 includes a mounting ring 91 , a plurality of limiting grooves are arranged in a uniform circumferential array on the inner side of the mounting ring 91 , a pawl 92 is hinged in the limiting groove, and the middle part of the pawl 92 is connected to the mounting ring 91 by a spring 93 .

[0046] Embodiment 2: A torque sensor installation structure is used to install the torque sensor in the five-way bracket 16 of a power-assisted bicycle, wherein a ring gasket 20 is fixed to the outer surface of the cylinder 5, a first sealing plate 12 is provided between the gear 4 and the first bevel gear 13, and the first sealing plate 12 can be connected to the five-way bracket 16 threadedly, and a second sealing plate 21 is provided on the side of the shaft 1 away from the gear, and the second sealing plate 21 can be connected to the five-way bracket 16 threadedly.

[0047] In this embodiment, an extension tube 17 is embedded in the bottom of the five-way joint 16, the motor 18 has a motor shaft 19, and a straightening tube is provided at a position close to the motor shaft 19 of the motor 18, and the straightening tube can be threadedly connected to the extension tube, a square groove is provided at the bottom of the second bevel gear 14, and the end of the motor shaft 19 has a square head.

[0048] In this way, the motor can be effectively installed and the shaft can also be positioned.

[0049] In addition, a hole is opened in the middle of the bottom bracket to allow the integrated cable to pass through it.

[0050] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A torque sensor for a power-assisted bicycle, characterized in that: it includes a shaft body, a strain gauge, a gear and a cylinder body. Among them, one end of the shaft body is rotatably arranged in the cylinder body by means of a bearing, and the other end of the shaft body is provided with a second stepped groove for installing an inner transmission component. The gear is rotatably arranged in the cylinder body by means of a bearing and is at one end close to the second stepped groove. A through groove and a third stepped groove are provided in the middle of the gear. The through groove is for the shaft body to pass through, and the third stepped groove is for installing an outer transmission component. The inner transmission component and the outer transmission component cooperate with each other so that when the shaft body rotates clockwise, the gear can be driven to rotate. When the gear rotates clockwise, the shaft body can remain stationary. A groove body is provided at one end of the shaft body away from the gear for embedding the strain gauge; a first stepped groove is provided in the middle of the shaft body for accommodating an electrical connection component. The electrical connection component includes a mounting frame, a conductive block, a first wire, a second wire and a conducting ring. Among them, the mounting frame is fixedly embedded in the cylinder body, and a plurality of conductive blocks are fixed on the mounting frame. At least two conductive blocks are connected with the first wire, and at least two conductive blocks are connected with the second wire; a plurality of conducting rings are fixed on the shaft body, and the number of the conducting rings is equal to the sum of the number of the first wires and the number of the second wires; the conducting ring corresponding to the first wire is electrically connected to the strain gauge by means of a third wire; the conducting ring corresponding to the second wire is electrically connected to the strain gauge by means of a fourth wire; it further includes an integrated cable, and a fifth wire and a sixth wire are arranged in the integrated cable. Among them, the fifth wire is electrically connected to the conductive block corresponding to the first wire, and the sixth wire is connected to the conductive block corresponding to the second wire; a ring body is coaxially fixed on the shaft body, a counting strip is fixed on the outer peripheral side of the ring body, a counter is fixed on the inner wall of the cylinder body, and a controller is further included. The controller jointly controls the driving force of an external motor on the gear according to the feedback of the counter and the feedback of the strain gauge. And when the counter feeds back that the rotational speed of the shaft body is greater than the rotational speed threshold and the strain gauge feeds back that the torque is less than the stress threshold, at this time the controller controls the external motor to reduce the driving force on the gear; when the rider reciprocally drives the shaft body to rotate in a small range in a clockwise and counterclockwise alternating manner, the controller controls the external motor to reduce the driving force on the gear.

2. The torque sensor for a power-assisted bicycle according to claim 1, characterized in that: a mounting ring is embedded between the conducting ring and the shaft body, and adjacent two conducting rings are separated by a spacer ring. Both the mounting ring and the spacer ring are made of non-conductive materials.

3. The torque sensor for a power-assisted bicycle according to claim 1, characterized in that: the first wire, the third wire and the fifth wire are used for power transmission, and the second wire, the fourth wire and the sixth wire are used for signal transmission.

4. The torque sensor for a power-assisted bicycle according to claim 1, characterized in that: a V-shaped ring groove is provided on the surface of the conducting ring.

5. The torque sensor for a power-assisted bicycle according to claim 1, characterized in that: A first bevel gear is coaxially fixed on one side of the gear. The first bevel gear is rotatably connected to the shaft and the cylinder by bearings respectively. The first bevel gear is meshed with the second bevel gear at 90 degrees. The second bevel gear is rotatably arranged in the cylinder by bearings and driven by an external motor.

6. A torque sensor for a power-assisted bicycle according to claim 1, Features: The inner transmission component is a ratchet, which is coaxially fixed on the shaft. The outer transmission component includes a mounting ring, and a plurality of limit grooves are arranged in a circumferentially uniform array on the inner side of the mounting ring. A pawl is hinged in the limit groove, and the middle part of the pawl is connected to the mounting ring by a spring.

7. A torque sensor mounting structure, used for mounting the torque sensor for a power-assisted bicycle according to any one of claims 5 to 6 in the bottom bracket of the power-assisted bicycle, Features: A ring gasket is fixed on the outer surface of the cylinder, a first sealing plate is arranged between the gear and the first bevel gear, the first sealing plate can be connected to the five-way thread, and a second sealing plate is arranged on the side of the shaft away from the gear, the second sealing plate can be connected to the five-way thread.

8. A torque sensor mounting structure according to claim 7, Features: An extension tube is embedded in the bottom of the five-way coupling, the motor has a motor shaft, a stabilizing tube is arranged near the motor shaft, the stabilizing tube can be threadedly connected to the extension tube, a square groove is provided at the bottom of the second bevel gear, and the end of the motor shaft has a square head.

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