Seat frame angle detection device

Abstract

The application discloses a seat framework angle detection device and relates to the technical field of automobile interior parts, which comprises a fixed disc, a movable block, a rotary transmission assembly, an angle sensing assembly and a wire harness assembly; the fixed disc is fixedly installed on the outside of a seat framework and keeps relative stillness with the seat framework and serves as an overall installation reference; the movable block is sleeved on the outer periphery of a seat rotating shaft and is located between a seat angle adjuster and the rotary transmission assembly; the movable block is provided with a long-strip-shaped movable groove extending in the radial direction; the long-strip-shaped movable groove is in radial sliding fit with the seat rotating shaft and is used for compensating the radial deviation of the rotating shaft caused by eccentric movement of the seat angle adjuster; and the rotary transmission assembly is coaxially sleeved on the outer periphery of the seat rotating shaft and rotates synchronously with the seat rotating shaft. The application realizes the effects of automatic compensation of eccentric movement of the seat angle adjuster and self-adaptive adjustment of the radial deviation of the rotating shaft, and solves the problems of part jamming and detection structure dislocation caused by eccentric movement.

Description

Technical Field

[0001] This invention relates to the technical field of automotive interior parts, and in particular to a seat frame angle detection device. Background Technology

[0002] The backrest of a car seat adjusts its tilt angle using a seat pivot and seat adjuster. The seat frame angle detection device is a sensing component installed on the pivot on the outer side of the seat frame. Its core function is to collect the seat back rotation angle in real time, identify the seat adjustment posture, and output standardized angle electrical signals. This provides data support for intelligent functions such as vehicle seat memory, autonomous driving seat posture adaptation, and airbag posture linkage, making it an indispensable core sensing component of the intelligent car seat control system.

[0003] Currently, most angle detection devices for automotive seats on the market adopt an assembly structure where a mechanical encoder is rigidly connected to the seat shaft. The encoder base is directly and rigidly locked to the seat frame, and the encoder detection shaft and the seat shaft are rigidly connected via a flange without an independent buffer compensation structure; there is no sliding transition component between the transmission components and the angle adjuster; the signal harness is directly laid along the periphery of the seat shaft without distinguishing between the moving and fixed areas, and the entire system relies on a single rigid connector to achieve coaxial alignment between the encoder and the shaft.

[0004] During operation, the seat adjuster generates an eccentric compound motion, causing radial offset of the seat shaft. The rigid connection structure has no radial adjustment margin, which can easily cause the coaxiality of the encoder detection shaft and the seat shaft to deviate, resulting in distorted angle detection values. Furthermore, the rigid connection lacks a sliding adapter structure, causing components to squeeze and jam each other during eccentric shaft movement, resulting in jamming of the seat back adjustment. All wiring harnesses are arranged in the movement area around the shaft. When the seat is repeatedly adjusted, the wiring harnesses continuously rub and interfere with the rotating components, which can easily lead to wire wear, signal breakage, and inability to output angle signals stably for a long time. Summary of the Invention

[0005] This application provides a seat frame angle detection device, which realizes automatic compensation for the eccentric movement of the seat adjuster and adaptive adjustment of the radial offset of the rotating shaft, thus solving the problems of component jamming and misalignment of the detection structure caused by eccentric movement.

[0006] This application provides a seat frame angle detection device, which adopts the following technical solution: A seat frame angle detection device includes a fixed plate, a movable block, a rotary transmission assembly, an angle sensing assembly, and a wiring harness assembly; The fixing plate is fixedly installed on the outside of the seat frame and remains relatively stationary with respect to the seat frame, serving as the overall installation reference. The movable block is sleeved on the outer periphery of the seat pivot and located between the seat adjuster and the rotary transmission assembly. The movable block has a radially extending elongated movable groove, which forms a radial sliding fit with the seat pivot to compensate for the radial offset of the pivot caused by the eccentric movement of the seat adjuster. The rotary transmission component is coaxially mounted on the outer circumference of the seat shaft and rotates synchronously with the seat shaft, used to transmit the rotational motion of the seat shaft to the angle sensing component; The angle sensing component is fixedly mounted at the center of the fixed plate. The detection axis of the angle sensing component is arranged coaxially with the seat shaft, and is used to collect the rotation angle of the seat shaft and output the angle electrical signal. One end of the wiring harness assembly is connected to the signal and power supply ports of the angle sensing assembly, and the other end extends outward along the side of the fixed disk and is arranged in the non-moving area, isolated from the moving parts.

[0007] Preferably, it further includes an elastic coaxial positioning circlip and a radial support spring; the elastic coaxial positioning circlip encircles the mechanical encoder detection shaft and the inner ring of the rotating disk, and the radial support spring maintains a pre-compression of 0.15-0.25mm after assembly. The radial support spring is made of silicon manganese spring steel with an elastic stiffness of 1200-1600N / mm; the elastic coaxial positioning circlip and the inner ring of the rotating disk adopt a radial interference fit of 0.02-0.04mm.

[0008] Preferably, it also includes a fully enclosed dustproof cover; the fully enclosed dustproof cover is fixedly installed on the outside of the fixed plate, and completely covers the fixed plate, the angle sensing component and the lead-out area of ​​the wiring harness component.

[0009] Preferably, the rotary transmission component is a rotary disk, and the angle sensing component is a mechanical encoder; The rotating disk is sleeved on the outer circumference of the seat shaft, and is coaxially aligned and rotates synchronously with the seat shaft and the mechanical encoder detection axis; the mechanical encoder is fixedly assembled at the center of the fixed disk, and the mechanical encoder detection axis is arranged coaxially with the seat shaft.

[0010] Preferably, the rotary transmission assembly includes a transmission shaft, a drive gear, a grating gear, and fan blades; the angle sensing assembly includes photoelectric devices and a PCBA board. Preferably, the drive shaft is coaxially connected to the seat shaft, the drive gear is fixed on the drive shaft, and the grating gear meshes with the drive gear for transmission; the fan blade is coaxially fixed to the center of the grating gear and rotates synchronously; the photoelectric device is fixed on the fixed disk, and the photoelectric device has a groove to accommodate the fan blade, and generates photoelectric signals by sensing the rotation of the fan blade; the PCBA board integrates a signal protection circuit composed of magnetic beads and ESD tubes.

[0011] Preferably, the number of fan blades is not less than two and they are evenly distributed along the circumference at equal angles; the transmission ratio between the grating gear and the drive gear is 1:N, where N is an integer greater than 1.

[0012] Preferably, the optoelectronic device is a dual-output optoelectronic device, with the two output channels staggered along the tangent direction of the fan blade rotation trajectory, and the staggered distance is equal to one-quarter of the distance between adjacent edges of the fan blade.

[0013] Preferably, the rotary transmission assembly includes a transmission shaft and a disk; the angle sensing assembly includes a ring array magnet, a Hall chip, and a PCBA board.

[0014] Preferably, the drive shaft is coaxially connected to the seat shaft, and the disk is coaxially fixed to the end of the drive shaft; the annular array magnet is fixed inside the disk, with no less than eight magnets distributed at equal angles along the circumference; the Hall chip is fixedly installed on the fixed disk and located below the disk, and outputs an angle signal by sensing the change in the magnetic field generated by the rotation of the disk; the PCBA board integrates a signal protection circuit composed of magnetic beads and ESD tubes.

[0015] In summary, this application has the following beneficial effects: 1. In order to solve the functional defects of radial offset of the rotating shaft and inaccuracy of encoder coaxiality caused by eccentric movement of seat adjuster, the present invention further optimizes the invention by setting a movable block with radial elongated movable groove. The movable block is arranged between the rotating disk and the adjuster and forms a radial sliding fit with the rotating shaft to achieve the effect of automatic compensation of eccentric displacement of the rotating shaft.

[0016] 2. To address the functional defects of the encoder mounting reference being prone to shaking and the lack of stable support in coaxial arrangement, this invention further optimizes the system by setting up a fixed plate that is relatively stationary with respect to the seat frame. The mechanical encoder is fixedly mounted at the center of the fixed plate with its axis coaxial with the seat's rotating shaft, thereby achieving the effect of stable encoder detection reference and unified coaxial positioning reference.

[0017] 3. To address the functional defect that the encoder cannot synchronously acquire the rotation angle along with the seat shaft, this invention further optimizes the process by providing a rotating disk coaxially fitted around the outer circumference of the seat shaft. The rotating disk synchronously follows the rotation of the seat shaft and aligns with the encoder detection shaft, thereby achieving the effect of synchronously transmitting the rotational motion of the shaft to the encoder and acquiring the angle in real time.

[0018] 4. To address the functional defects of wire harnesses being prone to wear and interference when placed in the moving area, this invention further optimizes the system by providing a zoned wire harness assembly. One end of the wire harness is connected to the encoder, and the other end extends along the side of the fixed disk to the non-moving area, thereby achieving complete isolation between the wire harness and the moving parts and preventing wire wear and breakage.

[0019] 5. To further optimize the invention and address the functional defect of continuous coaxiality deviation under long-term vibration, this invention also adds an elastic coaxial positioning retainer and a radial support spring. The retainer surrounds the encoder shaft and the rotating disk, and the spring continuously applies preload to achieve stable control of coaxial error and continuous stability of detection accuracy under vibration conditions. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the seat frame angle detection device in Embodiment 1. Figure 2 This is an exploded view of the internal structure of the seat frame angle detection device in Embodiment 1. Figure 3 This is a schematic diagram of the connection structure between the elastic coaxial positioning clasp and the radial support spring in Embodiment 2. Figure 4 This is a schematic diagram of the overall installation structure of the photoelectric structure in Embodiment 3; Figure 5 This is a schematic diagram of the connection structure between the fan blade and the optoelectronic device in Embodiment 3; Figure 6 This is a schematic diagram of the connection structure between the magnet and the Hall chip in Embodiment 4; Explanation of reference numerals in the attached drawings: 1. Movable block; 2. Rotary disk; 3. Mechanical encoder; 4. Fixed disk; 5. Wiring harness assembly; 6. Flexible coaxial positioning ring; 7. Radial support spring; 8. Drive gear; 9. Grating gear; 10. PCBA; 11. Optoelectronic device; 12. Fan blade; 13. Drive shaft; 14. Magnet; 15. Hall effect chip. Detailed Implementation

[0021] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0022] Example 1: This invention discloses a seat frame angle detection device, such as... Figure 1 and Figure 2 As shown, it includes a movable block 1, a rotating disk 2, a mechanical encoder 3, a fixed disk 4, and a wire harness assembly 5.

[0023] Specifically, the fixed plate 4 serves as the installation reference for the device and is fixedly installed on the outside of the seat frame, remaining relatively stationary with respect to the seat frame. It is located at the connection point between the seat adjuster and the detection component, providing fixed support for the mechanical encoder 3.

[0024] The mechanical encoder 3 is fixedly mounted at the center of the fixed plate 4. The encoder detection axis is coaxial with the seat rotation axis and is located in the middle area between the fixed plate 4 and the rotating plate 2. It is the core execution component for angle detection.

[0025] The rotating disk 2 is mounted on the outer periphery of the seat shaft and located outside the detection end of the mechanical encoder 3. It is coaxially aligned with the seat shaft and the detection shaft of the mechanical encoder 3 and rotates synchronously with the seat shaft.

[0026] The movable block 1 is fitted around the outer periphery of the seat pivot and is located between the rotating disk 2 and the seat adjuster. The movable block 1 has a long movable groove that forms a radial sliding fit with the seat pivot, which is adapted to the eccentric + rotational composite motion trajectory of the adjuster.

[0027] One end of the wiring harness assembly 5 is connected to the signal / power supply port of the mechanical encoder 3, and the other end extends outward along the side of the fixed disk 4 and is arranged in the non-moving area of ​​the device to avoid interference with moving parts such as the rotating disk 2 and the movable block 1.

[0028] By setting an encoder on the angle adjuster and setting a movable block 1 on the seat frame, the movable block 1 is fitted outside the seat's pivot, and a long strip-shaped movable groove is provided between the movable block 1 and the seat pivot, so that when the angle adjuster moves eccentrically, the movable block 1 can still cooperate with the encoder and perform detection.

[0029] The mechanical encoder 3 solution converts the rotational motion of the seat frame drive shaft into on / off signals of mechanical contacts, enabling precise detection of angle changes. This solution leverages the hardware structure of the mechanical encoder 3, directly linking with the drive shaft without relying on optical or magnetic field sensing principles. Its core advantages lie in its strong anti-interference capability and wide environmental adaptability, making it suitable for scenarios with dynamic angle variations during seat adjustment.

[0030] Example 2: When vehicles travel long-term on harsh driving conditions such as rural dirt roads, continuous speed bumps, and gravel roads, they must withstand vibrations with a frequency of 10-50Hz and an amplitude of 0.5-3mm. Furthermore, the road environment contains high concentrations of dust, metal debris, and other impurities. Simultaneously, users frequently adjust the seat back angle during daily commutes and long-distance driving. Seat angle detection data is crucial for functions such as seat memory, airbag posture matching, and autonomous driving seat posture adaptation. Therefore, strict requirements are placed on the long-term stable operation and detection accuracy of the detection device, ensuring a deviation-free detection process.

[0031] When the original detection device operates under the aforementioned harsh conditions, it is susceptible to continuous impact from high-frequency vibration, resulting in a slight offset of 0.1-0.3mm in the coaxiality between the mechanical encoder 3 and the seat shaft. At the same time, dust and metal debris tend to accumulate rapidly inside the long slot of the moving block 1, which in turn causes problems such as delayed eccentric compensation action and motion jamming. Ultimately, this leads to frequent jumps in the angle detection signal and a significant decrease in the accuracy of rotation direction recognition, making it unable to meet the usage requirements under harsh conditions.

[0032] To address the aforementioned issues, and targeting the core pain points of long-term bumpy vibration and high-dust environments, a triple protection structure was designed and configured, featuring coaxiality anti-deviation positioning, dustproof self-cleaning of sliding pairs, and wear-resistant drag reduction. This effectively avoids problems such as encoder coaxial misalignment and dust accumulation and jamming of sliding pairs caused by vibration, fundamentally solving the problems of eccentric compensation action asynchrony and angle detection signal distortion, and ensuring the device's long-term stable detection capability under harsh road conditions.

[0033] like Figure 3 As shown, in terms of coaxiality anti-deviation positioning, an elastic coaxial positioning ring 6 and a radial support spring 7 are set between the fixed disk 4 and the rotating disk 2. The elastic coaxial positioning ring 6 encircles the detection shaft of the mechanical encoder 3 and the inner ring of the rotating disk 2. After assembly, the radial support spring 7 maintains a pre-compression of 0.15-0.25mm. The radial support spring 7 is made of silicon manganese spring steel with an elastic stiffness of 1200-1600N / mm. The elastic coaxial positioning ring 6 and the inner ring of the rotating disk 2 adopt a radial interference fit of 0.02-0.04mm. Relying on the synergistic constraint of this pre-compression, elastic stiffness, and radial interference fit, the radial deviation caused by bumps and vibrations is offset, ensuring that the coaxiality error between the mechanical encoder 3 and the seat shaft is always controlled within the range of ≤0.05mm, thus ensuring the stability of the detection benchmark.

[0034] Example 3: As Figure 4 and Figure 5 As shown, the product is installed on the back of the seat frame. At this position, the product is fixed relative to the drive shaft 13, making it less susceptible to eccentric movement from the adjuster. The drive shaft 13 is coaxially connected to the drive gear 8, which meshes with a grating gear 9. A fan blade 12 is coaxially connected to the center of the grating gear 9. Specifically, the fan blade 12 is fixedly installed in the groove of the photoelectric device 11. The drive shaft 13 drives the drive gear 8 to rotate, which in turn drives the fan blade 12 to rotate. The fan blade 12 moves within the groove of the photoelectric device 11, and finally, the photoelectric device 11 outputs a corresponding electrical signal.

[0035] The number of fan blades 12 is positively correlated with the encoder resolution, and different precision requirements can be adapted by adjusting the number of fan blades 12. Furthermore, the transmission ratio between the drive gear 8 and the grating gear 9 is set to 1:N; N is an integer. The detection accuracy is improved by amplifying the rotation angle. For example, when the transmission ratio is 1:3, a 1° rotation of the drive shaft 13 corresponds to a 3° rotation of the grating gear 9, which improves the pulse signal resolution by 3 times. Dual-channel signal anti-interference design. In addition, by setting a combination protection circuit of ferrite beads and ESD tubes on the PCBA10 board, the interference of automotive electromagnetic radiation on photoelectric signals is suppressed, ensuring stable signal phase difference and avoiding misjudgment of direction recognition.

[0036] Example 4: Figure 6 As shown, the product is installed on the back of the seat frame. At this position, the product is fixed relative to the drive shaft 13, making it less susceptible to the eccentric movement of the adjuster. A disk is coaxially connected to the center of the drive shaft 13. A Hall chip 15 is installed inside the disk, and eight magnets 14 are evenly spaced on the upper surface of the Hall chip 15. Specifically, the drive shaft 13 drives the disk to rotate, and the Hall chip 15 receives changes in the magnetic field below the disk, ultimately outputting a corresponding electrical signal.

[0037] The eight magnets 14 are arranged in a ring array, with the center-to-center angle of adjacent magnets 14 being 45°, which can improve the resolution. In addition, the two Hall chips 15 are staggered along the tangent of the disk, with a spacing of 1 / 4 of the center distance of the magnet 14, to ensure that the dual signals generate a stable timing difference of 10ms±1ms during rotation, and to avoid the failure of orientation recognition due to the failure of a single chip. Furthermore, magnet 14 is made of neodymium iron boron material to ensure that Hall chip 15 can stably trigger signals, while avoiding chip saturation caused by excessive magnetic field.

[0038] Working Principle: First, the pre-installation and fixing of the entire detection device are completed. The fixing plate 4 is locked and fixed to the outside of the seat frame, ensuring that the fixing plate 4 and the seat frame remain relatively stationary throughout, thus establishing a stable installation benchmark. Then, the mechanical encoder 3 is assembled in the center position of the fixing plate 4, and the encoder detection axis is adjusted to ensure that it is strictly coaxial with the seat shaft, completing the positioning and installation of the core component for angle detection. Next, the rotating plate 2 and the movable block 1 are sequentially fitted onto the outer circumference of the seat shaft from the outside to the inside. The position is adjusted so that the rotating plate 2 fits against the detection end of the mechanical encoder 3, and the movable block 1 is clamped between the rotating plate 2 and the seat angle adjuster, so that the long strip-shaped movable groove of the movable block 1 forms a freely sliding radial fit structure with the seat shaft. At the same time, the wiring harness assembly 5 is assembled, with one end of the wiring harness plugged into the signal and power supply ports of the mechanical encoder 3, and the other end extending outward along the side of the fixing plate 4, completely stored in the non-moving area away from the shaft, avoiding all moving parts.

[0039] Subsequently, the user operates the seat adjustment handle to drive the seat adjuster, causing the seat back to tilt and rotate. The seat shaft rotates synchronously, and the eccentric structure of the adjuster causes a slight radial offset in the shaft. When the shaft experiences radial displacement, the movable block 1 automatically adapts to the eccentric trajectory of the shaft through its radially elongated movable groove, offsetting the radial offset caused by the adjuster. This prevents the rotating disk 2 and encoder detection shaft from being pulled out of place by the shaft, ensuring that the coaxial structure does not deform or jam. Next, the seat shaft drives the outer rotating disk 2 to rotate synchronously. The rotating disk 2 and encoder detection shaft are coaxially aligned, transmitting the complete rotation angle and direction of the shaft synchronously to the mechanical encoder 3. The encoder, relying on its internal mechanical contact structure, converts the continuous rotational displacement into continuous on / off electrical signals, accurately quantifying the real-time deflection angle of the seat back, and distinguishing between forward and reverse rotation actions through signal timing.

[0040] Meanwhile, the radial support spring 7 continuously outputs a constant preload force to the elastic coaxial positioning circlip 6. The circlip encircles the encoder detection shaft and the inner ring of the rotating disk 2, offsetting the radial vibration caused by vehicle travel bumps and controlling the coaxiality error to a very small range. The spiral guide dust removal grooves on both sides of the long groove of the moving block 1 rely on the centrifugal airflow generated by the rotation to continuously blow away the dust in the grooves. The PTFE bushing reduces sliding friction loss, and the outer fully enclosed dustproof cover blocks the intrusion of external impurities. Multiple auxiliary structures ensure the long-term smooth operation of the moving parts. Subsequently, the angle electrical signal generated by the mechanical encoder 3 is stably transmitted outward through the wiring harness assembly 5. The wiring harness is arranged in the non-moving area and will not be pulled or rubbed when the seat is adjusted.

[0041] Ultimately, the vehicle controller receives the continuous angle signals transmitted by the wiring harness and completes functions such as seat angle recording and posture linkage. The entire device relies on the coordinated operation of the eccentric compensation structure, coaxial positioning structure, and partitioned wiring harness structure of the movable block 1 to synchronously collect the seat rotation angle throughout the process. It is not affected by the eccentricity of the angle adjuster, road vibration, dust and impurities, and continuously outputs high-precision, distortion-free angle sensing signals.

[0042] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A seat frame angle detection device, characterized in that, Includes a fixed disk (4), a movable block (1), a rotary transmission assembly, an angle sensing assembly, and a wiring harness assembly (5); The fixing plate (4) is fixedly installed on the outside of the seat frame and remains relatively stationary with respect to the seat frame, serving as the overall installation reference; The movable block (1) is sleeved on the outer periphery of the seat shaft and located between the seat adjuster and the rotary transmission assembly. The movable block (1) has a long strip-shaped movable groove extending radially. The long strip-shaped movable groove and the seat shaft form a radial sliding fit to compensate for the radial offset of the shaft caused by the eccentric movement of the seat adjuster. The rotary transmission component is coaxially mounted on the outer circumference of the seat shaft and rotates synchronously with the seat shaft, used to transmit the rotational motion of the seat shaft to the angle sensing component; The angle sensing component is fixedly mounted at the center of the fixed disk (4). The detection axis of the angle sensing component is arranged coaxially with the seat shaft, and is used to collect the rotation angle of the seat shaft and output the angle electrical signal. One end of the wiring harness assembly (5) is connected to the signal and power supply port of the angle sensing assembly, and the other end extends outward along the side of the fixed disk (4) and is arranged in the non-moving area, isolated from the moving parts.

2. The seat frame angle detection device according to claim 1, characterized in that, It also includes an elastic coaxial positioning circlip (6) and a radial support spring (7); the elastic coaxial positioning circlip (6) surrounds the detection shaft of the mechanical encoder (3) and the inner ring of the rotating disk (2); the radial support spring (7) maintains a pre-compression of 0.15-0.25mm after assembly; the radial support spring (7) is made of silicon manganese spring steel with an elastic stiffness of 1200-1600N / mm; the elastic coaxial positioning circlip (6) and the inner ring of the rotating disk (2) are radially interference-fitted with a diameter of 0.02-0.04mm.

3. The seat frame angle detection device according to claim 1, characterized in that, It also includes a fully enclosed dustproof cover; the fully enclosed dustproof cover is fixedly installed on the outside of the fixed plate (4), and covers the fixed plate (4), the angle sensing component and the lead-out area of ​​the wiring harness component (5).

4. The seat frame angle detection device according to claim 1, characterized in that, The rotary transmission component is a rotary disk (2), and the angle sensing component is a mechanical encoder (3). The rotating disk (2) is sleeved on the outer circumference of the seat shaft, and is coaxially aligned with the seat shaft and the detection shaft of the mechanical encoder (3) and rotates synchronously; the mechanical encoder (3) is fixedly assembled at the center of the fixed disk (4), and the detection axis of the mechanical encoder (3) is arranged coaxially with the seat shaft.

5. The seat frame angle detection device according to claim 1, characterized in that, The rotary transmission assembly includes a transmission shaft, a drive gear, a grating gear, and fan blades; the angle sensing assembly includes photoelectric devices and a PCBA board.

6. The seat frame angle detection device according to claim 5, characterized in that, The drive shaft is coaxially connected to the seat shaft, the drive gear is fixed on the drive shaft, and the grating gear meshes with the drive gear for transmission; the fan blade is coaxially fixed to the center of the grating gear and rotates synchronously; the photoelectric device is fixed on the fixed disk (4), and the photoelectric device has a groove to accommodate the fan blade, and generates photoelectric signals by sensing the rotation of the fan blade; the PCBA board integrates a signal protection circuit composed of a magnetic bead and an ESD tube.

7. The seat frame angle detection device according to claim 6, characterized in that, The number of fan blades is no less than two and they are evenly distributed along the circumference at equal angles; the transmission ratio between the grating gear and the drive gear is 1:N, where N is an integer greater than 1.

8. The seat frame angle detection device according to claim 7, characterized in that, The optoelectronic device is a dual-output type optoelectronic device, with the two output channels staggered along the tangent direction of the fan blade rotation trajectory, and the staggered distance is equal to one-quarter of the distance between adjacent edges of the fan blade.

9. The seat frame angle detection device according to claim 1, characterized in that, The rotary transmission assembly includes a transmission shaft and a disk; the angle sensing assembly includes a ring array magnet, a Hall chip, and a PCBA board.

10. The seat frame angle detection device according to claim 9, characterized in that, The drive shaft is coaxially connected to the seat shaft, and the disk is coaxially fixed to the end of the drive shaft; the annular array magnet is fixed inside the disk, with no less than eight magnets distributed at equal angles along the circumference; the Hall chip is fixedly installed on the fixed disk (4) and located below the disk, and outputs an angle signal by sensing the change in the magnetic field generated by the rotation of the disk; the PCBA board integrates a signal protection circuit composed of a magnetic bead and an ESD tube.

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