Low beam module adjusting device

Abstract

The utility model relates to the technical field of automobile lighting, especially near light module adjusting device, include: base, pivot, with base rotation is connected, one end connects near light optical module, drive unit, is fixed on the base, flexible transmission unit, is connected between the output of drive unit and pivot, is used for the rotation movement of drive unit output is converted to the torque acting on pivot, electromagnetic lock unit, set up on the base and cooperate with pivot, wherein, flexible transmission unit includes the flexible transmission element that can be received and is not transmitted and pushes the pressure, electromagnetic lock unit configuration is: when electrifying, generates the magnetic force to directly act on pivot, forms the friction pair of restriction pivot rotation, when power failure, magnetic force eliminates, friction pair separates, the utility model discloses through with flexible no backlash transmission and rigid direct locking two function modules separate and integration, realize no backlash, low noise, high accuracy and position keep the stability of firmness.

Description

Technical Field

[0001] This utility model relates to the field of automotive lighting technology, and in particular to a low beam module adjustment device. Background Technology

[0002] With the development of automotive intelligence and electrification, adaptive headlight systems (such as AFS and ADB) are becoming increasingly popular. Such systems require the low beam module to make rapid, precise and quiet dynamic angle adjustments based on vehicle attitude (such as pitch), steering or road conditions in order to achieve optimal lighting effect and safety.

[0003] Currently, the mainstream solutions for adjusting the low beam module angle mostly employ rigid mechanical transmission mechanisms, such as micro stepper motors or servo motors driving the module rotation through reduction gear sets or precision screws. In practical applications, especially in scenarios involving long-term, high-frequency, minute angle adjustments, these traditional solutions inevitably suffer from manufacturing and assembly gaps in rigid transmission mechanisms like gear meshing and screw pairs. Over time, wear increases these gaps, leading to a backlash between the adjustment command and the actual position output, severely reducing adjustment accuracy and repeatability. High-frequency, minute angle adjustments mean frequent starts, stops, and reversals of gears or screws, easily generating audible mechanical friction and impact noise, affecting the overall vehicle NVH quality. Simultaneously, these frequent micro-movements exacerbate wear on contact surfaces, shortening service life. Once adjusted, maintaining the module position typically relies on the motor's self-locking torque or the friction of the transmission mechanism. In environments with continuous vehicle vibration, this method may result in slow displacement or retraction, failing to achieve absolutely stable position maintenance.

[0004] Therefore, to address the above problems, a low beam module adjustment device is proposed. By separating and integrating two functional modules, flexible backlash-free transmission and rigid direct locking, a backlash-free, low-noise, high-precision, and stable position holding is achieved. Utility Model Content

[0005] In order to overcome the problems of mechanical backlash, noise and wear, and insufficient holding force in the daily use of traditional low beam module angle adjustment mechanisms.

[0006] The technical solution of this utility model is: a low beam module adjustment device, comprising:

[0007] Base;

[0008] A rotating shaft is rotatably connected to the base, with one end connected to the near-beam optical module;

[0009] The drive unit is fixed to the base;

[0010] A flexible transmission unit is connected between the output end of the drive unit and the rotating shaft, and is used to convert the rotational motion output by the drive unit into a torque acting on the rotating shaft;

[0011] An electromagnetic locking unit is disposed on the base and cooperates with the rotating shaft;

[0012] The flexible transmission unit includes a retractable flexible transmission element that does not transmit pushing force; the electromagnetic locking unit is configured to generate magnetic force when energized to act directly on the rotating shaft, forming a friction pair that restricts the rotation of the rotating shaft; when de-energized, the magnetic force is eliminated and the friction pair separates.

[0013] Preferably, when the module angle needs to be adjusted, the control unit first commands the electromagnetic locking unit to de-energize, and the reset spring separates the friction block from the brake disc, releasing the shaft constraint; then, the control unit commands the drive motor to rotate precisely, winding or releasing the metal strip; the metal strip pulls the worm spring, gently and without impact driving the shaft to rotate; the angle sensor provides real-time position feedback, forming a closed-loop control; after adjustment, the control unit immediately commands the electromagnetic locking unit to energize, and the electromagnetic force drives the friction block to forcefully press against the brake disc, generating a huge static friction torque to rigidly lock the shaft; finally, the drive motor stops working; the whole process is completed instantaneously, achieving smooth adjustment while maintaining rigidity, adapting to the requirements of vehicle lights for high-frequency, micro-volume, quiet, and highly reliable adjustment.

[0014] Preferably, the flexible transmission element is a metal belt; the drive unit includes a motor and a reel driven by the motor, with one end of the metal belt wound and fixed on the reel.

[0015] Preferably, the flexible transmission unit further includes a worm spring box, which is fixed to the rotating shaft; the other end of the metal strip is connected to the outer end of the worm spring inside the worm spring box, and the inner end of the worm spring is fixed to the worm spring box.

[0016] Preferably, the electromagnetic locking unit includes:

[0017] The brake disc is coaxially and fixedly connected to the rotating shaft;

[0018] An electromagnetic actuator is fixed on the base, and a friction block is provided at its end near the brake disc;

[0019] The electromagnetic actuator is configured to drive the friction block to press against the end face or circumferential face of the brake disc when energized, thereby forming the friction pair.

[0020] Preferably, a reset elastic element is also included, which acts on the friction block or the moving part of the electromagnetic actuator to provide a tendency force to separate the friction block from the brake disc.

[0021] Preferably, the device also includes an angle detection unit for detecting the rotation angle of the shaft.

[0022] Preferably, the system also includes a control unit, which is electrically connected to the drive unit, the electromagnetic locking unit, and the angle detection unit, respectively.

[0023] The control unit is configured to: upon receiving an angle adjustment command, first control the electromagnetic locking unit to de-energize and release the rotating shaft, then control the drive unit to operate so as to drive the rotating shaft to rotate to the target angle through the flexible transmission unit, and then control the electromagnetic locking unit to energize to lock the rotating shaft.

[0024] The beneficial effects of this utility model are:

[0025] 1. This utility model relies entirely on the unidirectional tension of the metal belt and the elastic deformation of the worm spring for transmission, eliminating any gear meshing gaps and thus eliminating backlash and hysteresis. The metal belt drive and electromagnetic locking operation have extremely low noise, overcoming the meshing noise of traditional gears. Furthermore, the main wear occurs only on the friction pair during locking, and it is static friction, resulting in almost no wear on the transmission parts and improving the reliability of the device. The direct friction clamping force provided by the electromagnetic locking is much greater than the self-locking force of the motor, which can resist strong vibrations and ensure that the position does not drift. By separating and integrating the two functional modules of flexible backlash-free transmission and rigid direct locking, backlash-free, low-noise, high-precision, and stable position holding are achieved.

[0026] 2. This utility model ensures that the electromagnetic locking unit is in a locked state by default when the power is off, thus guaranteeing that the lighting settings remain unchanged after the vehicle is turned off and improving safety. Attached Figure Description

[0027] Figure 1 The diagram shown is a first three-dimensional structural schematic of the low beam module adjustment device of this utility model;

[0028] Figure 2 The diagram shown is a second three-dimensional structural schematic of the low beam module adjustment device of this utility model;

[0029] Figure 3 The diagram shown is a partial three-dimensional structural schematic of the low beam module adjustment device of this utility model;

[0030] Figure 4 The image shown is a top view of the low beam module adjustment device of this utility model;

[0031] Explanation of reference numerals in the attached drawings: 1. Base; 2. Shaft; 31. Motor; 32. Reel; 41. Metal belt; 42. Worm coil spring box; 51. Brake disc; 52. Electromagnetic actuator; 53. Friction block; 54. Push rod; 6. Angle detection unit; 61. Permanent magnet; 62. Hall sensor; 7. Reset elastic element; 71. Reset compression spring. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] Example 1

[0034] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 This utility model provides an embodiment: a low beam module adjustment device, comprising:

[0035] Base 1;

[0036] The rotating shaft 2 is rotatably connected to the base 1, and one end of it is connected to the near-beam optical module.

[0037] The drive unit is fixed on the base 1;

[0038] A flexible transmission unit is connected between the output end of the drive unit and the rotating shaft 2, and is used to convert the rotational motion output by the drive unit into a torque acting on the rotating shaft 2;

[0039] An electromagnetic locking unit is mounted on the base 1 and engages with the rotating shaft 2;

[0040] The flexible transmission unit includes a retractable flexible transmission element that does not transmit pushing force; the electromagnetic locking unit is configured to generate magnetic force when energized to act directly on the rotating shaft 2, forming a friction pair that restricts the rotation of the rotating shaft 2; when de-energized, the magnetic force is eliminated and the friction pair separates.

[0041] When the module angle needs to be adjusted, the control unit first commands the electromagnetic locking unit to de-energize, and the reset spring separates the friction block 53 from the brake disc 51, releasing the constraint of the rotating shaft 2. Subsequently, the control unit commands the drive motor 31 to rotate precisely, winding or releasing the metal strip 41. The metal strip 41 drives the rotating shaft 2 to rotate smoothly and without impact by pulling the worm spring. The angle sensor provides real-time feedback on the position, forming a closed-loop control. After the adjustment is in place, the control unit immediately commands the electromagnetic locking unit to energize, and the electromagnetic force drives the friction block 53 to press the brake disc 51 tightly, generating a huge static friction torque to rigidly lock the rotating shaft 2. Finally, the drive motor 31 stops working. The whole process is completed in an instant, achieving smooth adjustment while maintaining rigidity, which meets the requirements of vehicle lights for high-frequency, micro-scale, quiet, and highly reliable adjustment.

[0042] Furthermore, the flexible transmission element is a metal belt 41; the drive unit includes a motor 31 and a reel 32 driven by the motor 31, with one end of the metal belt 41 wound and fixed on the reel 32; the motor 31 drives the reel 32 to wind and unwind the metal belt 41 in both forward and reverse directions, converting the rotational motion into the linear extension and retraction motion of the metal belt 41; the metal belt 41 itself does not have compressive stiffness and can only transmit unidirectional tension, which is the basis for its backlash-free transmission; the reel 32 can be equipped with a micro reducer to increase torque.

[0043] Furthermore, the flexible transmission unit also includes a worm spring box 42, which is fixed to the rotating shaft 2. The other end of the metal belt 41 is connected to the outer end of the worm spring inside the worm spring box 42, and the inner end of the worm spring is fixed to the worm spring box 42. When the metal belt 41 is tightened by the rotating shaft 32, the tension acts on the outer end of the worm spring, causing the worm spring to tend to tighten or loosen, thereby smoothly converting the linear tension of the metal belt 41 into a torque that drives the rotating shaft 2 to rotate. The elastic characteristics of the worm spring make the transmission process smooth and shock-free. When the motor 31 releases the metal belt 41 in the reverse direction, the rotating shaft 2 rotates in the reverse direction under the action of the gravity torque of the low beam module itself, while simultaneously loosening the worm spring and sending out the metal belt 41. The entire transmission process has no rigid meshing, achieving zero backlash.

[0044] Furthermore, the electromagnetic locking unit includes:

[0045] Brake disc 51 is fixedly connected coaxially to rotating shaft 2;

[0046] An electromagnetic actuator 52 is fixed on the base 1, and a friction block 53 is provided at its end near the brake disc 51.

[0047] The electromagnetic actuator 52 is configured to drive the friction block 53 to press against the end face or circumferential surface of the brake disc 51 when energized, forming a friction pair.

[0048] The brake disc 51 is rigidly connected to the rotating shaft 2, and locking the brake disc 51 directly locks the rotating shaft 2; the electromagnetic actuator 52 can be in the form of an E-type electromagnet, etc. When energized, it generates a strong magnetic attraction force, which directly or through a mechanical lever pushes the friction block 53 (which can be made of wear-resistant ceramic or powder metallurgy material) to press the brake disc 51, generating a huge static friction torque, thereby achieving rigid and absolute locking of the rotating shaft 2 and resisting external vibration interference.

[0049] Furthermore, it also includes a reset elastic element 7, which acts on the moving parts of the friction block 53 or the electromagnetic actuator 52 to provide a tendency force to separate the friction block 53 from the brake disc 51. When the electromagnetic actuator 52 is de-energized, the force of the reset elastic element 7 ensures that the friction block 53 quickly and reliably disengages from the brake disc 51, releasing the rotating shaft 2 so that it can rotate freely for the next adjustment and avoid dragging.

[0050] Furthermore, it also includes an angle detection unit 6, which is used to detect the rotation angle of the rotating shaft 2. The angle detection unit 6 can be a non-contact angle sensor composed of a magnet mounted on the rotating shaft 2 and a Hall sensor 62 fixed on the base 1, which provides closed-loop feedback for the adjustment process and ensures adjustment accuracy.

[0051] Furthermore, it also includes a control unit, which is electrically connected to the drive unit, the electromagnetic locking unit, and the angle detection unit 6, respectively.

[0052] The control unit is configured to: upon receiving an angle adjustment command, first de-energize the electromagnetic locking unit to release the rotating shaft 2, then control the drive unit to run so as to drive the rotating shaft 2 to rotate to the target angle through the flexible transmission unit, and then energize the electromagnetic locking unit to lock the rotating shaft 2.

[0053] Upon receiving an angle adjustment command from the vehicle's upper-level controller (such as the headlight ECU), the electromagnetic locking unit is first de-energized to release the rotating shaft 2. Then, based on feedback from the angle detection unit 6, the drive unit is controlled to operate, driving the rotating shaft 2 to rotate to the target angle via the flexible transmission unit. Once the angle detection unit 6 confirms that the shaft is in place, the electromagnetic locking unit is immediately energized to forcefully lock the rotating shaft 2. Finally, the drive unit is de-energized. This separation control logic is clear, ensuring the accuracy of the adjustment action and the reliability of the locking.

[0054] Through the above steps, the transmission of this utility model relies entirely on the unidirectional tension of the metal belt 41 and the elastic deformation of the worm spring, without any gear meshing gap, thus eliminating backlash in principle and thereby eliminating backlash and hysteresis; the transmission of the metal belt 41 and the electromagnetic locking action have extremely low noise, overcoming the meshing noise of traditional gears; and the main wear only occurs on the friction pair during locking, and it is static friction, with almost no wear on the transmission part, improving the reliability of the device; the direct friction clamping force provided by the electromagnetic locking is much greater than the self-locking force of the motor 31, which can resist strong vibrations, ensure that the position does not drift, and achieve backlash-free, low-noise, high-precision, and stable position holding.

[0055] Example 2

[0056] Optionally, this embodiment provides a basic low beam module adjustment device; the device mainly includes a base 1, a rotating shaft 2, a drive unit, a flexible transmission unit, and an electromagnetic locking unit.

[0057] The base 1 serves as the supporting structure for the entire device and is fixedly installed inside the headlight housing. The rotating shaft 2 is rotatably connected to the base 1 via a bearing (such as a sliding bearing or a rolling bearing). One end of the shaft is used to rigidly mount the low beam optical module. The weight of the module and the optical center constitute the load torque acting on the rotating shaft 2.

[0058] The drive unit is fixed on the base 1. Its core is a miniature DC brushed motor 31 or a stepper motor 31, and the output shaft is connected to a precision reel 32. The motor 31 is selected with low torque requirements because it is mainly used to overcome the elastic deformation force and small friction force in the system, rather than directly driving the load.

[0059] The flexible transmission unit is connected between the output end (spool 32) of the drive unit and the rotating shaft 2; its core flexible transmission element is a high-strength, low-elongation stainless steel metal strip 41; one end of the metal strip 41 is fixed and wound on the spool 32, and the other end is connected to the rotating shaft 2; the key characteristic of the metal strip 41 is that it can only withstand tension and can hardly withstand pressure (i.e., it does not transmit thrust); when the spool 32 reverses and tries to push the metal strip 41, the metal strip 41 will loosen due to loss of tension and will not transmit reverse thrust to the rotating shaft 2, thus eliminating the reverse transmission gap (backlash) in physical principle.

[0060] The electromagnetic locking unit is mounted on the base 1 and directly engages with the rotating shaft 2. Its basic components include a brake disc 51 rigidly connected coaxially to the rotating shaft 2, and an electromagnetic actuator 52 fixed on the base 1. When the electromagnetic actuator 52 is energized, it generates a magnetic field. This magnetic force directly or indirectly drives a friction block 53 to press against the surface (end face or circumferential surface) of the brake disc 51, forming a friction pair with a high static friction coefficient. The frictional torque generated by this friction pair is much greater than the reverse torque that may be caused by the load on the rotating shaft 2, thereby achieving absolute locking of the rotating shaft 2. When the electromagnetic actuator 52 is de-energized, the magnetic force disappears, the friction block 53 separates from the brake disc 51, and the rotating shaft 2 returns to freedom.

[0061] When the low beam module angle needs to be adjusted, the electromagnetic locking unit is first de-energized and unlocked; the drive unit motor 31 starts, driving the reel 32 to rotate; if the module needs to rotate in one direction (e.g., lift), the motor 31 rotates forward to wind up the metal strip 41, the metal strip 41 is pulled and pulls its connection point with the rotating shaft 2, thereby applying a unidirectional rotational torque to the rotating shaft 2, driving the module to rotate; after adjustment, the electromagnetic locking unit is instantly energized, the friction block 53 forcefully locks the brake disc 51, rigidly fixing the rotating shaft 2 in the target position, and then the motor 31 stops; if reverse adjustment is required, the motor 31 reverses to release the metal strip 41, at which time the rotating shaft 2 and the module rotate in the opposite direction under the action of their own gravity torque, while pulling out the slack metal strip 41; during this process, the transmission always relies on unidirectional tension, without rigid impact or backlash.

[0062] Example 3

[0063] Optionally, this embodiment further refines the preferred structures of the flexible transmission unit and the electromagnetic locking unit based on embodiment 2.

[0064] The flexible transmission unit specifically includes a stainless steel metal strip 41, a reel 32 driven by a motor 31, and a worm spring box 42. The worm spring box 42 is a housing fixedly mounted on the rotating shaft 2. Inside it is a worm spring, the inner end of which is fixed to the central shaft (or inner wall) of the worm spring box 42, and its outer end extends out of the box and is fixedly connected to the end of the metal strip 41. The metal strip 41 is preferably a high-strength precision stainless steel strip with a thickness of 0.05-0.2mm and a width of 2-5mm.

[0065] The electromagnetic locking unit specifically includes a brake disc 51 fixedly connected coaxially to the rotating shaft 2, and an E-type miniature electromagnet as an electromagnetic actuator 52; a coil is wound on the iron core of the electromagnet; a friction block 53 made of wear-resistant material (such as ceramic or copper-based powder metallurgy) is set at the end of the electromagnet via a non-magnetic push rod 54 (or directly as part of the armature), facing the end face of the brake disc 51; the brake disc 51 is preferably made of steel to enhance the coefficient of friction and wear resistance with the friction block 53.

[0066] The device operates as follows:

[0067] Unlocking and Adjustment Preparation: The control unit (which can be integrated into the headlight ECU or be a standalone module) receives the adjustment command; first, it cuts off the current to the electromagnet coil in the electromagnetic locking unit, and the magnetic force disappears;

[0068] Soft transmission process: The control unit drives the motor 31 to rotate the reel 32 in the required direction and angle; taking the module lifting as an example: the motor 31 rotates forward, winding the metal strip 41; the metal strip 41 is under tension, and the tension at its end acts on the outer end of the worm spring, attempting to wind the worm spring tighter; since the inner end of the worm spring is fixed on the rotating shaft 2, this tendency to wind tight is converted into a torque that drives the rotating shaft 2 to rotate. Its size is related to the tension of the metal strip 41. and the stiffness coefficient of the coil spring It is related to the amount of deformation, and the relationship can be approximately expressed as follows: ,in This is the angular displacement of shaft 2; this torque smoothly and continuously drives shaft 2 to overcome the load torque. (Mainly generated by the gravity of the module) Rotation; there is no metallic impact sound throughout the transmission process, only a very low motor 31 running sound.

[0069] Rigid locking process: When the angle sensor (as described in Embodiment 4 below) reports that the rotating shaft 2 has reached the target angle, the control unit immediately applies a short-duration high-current pulse to the electromagnet coil; the electromagnet generates a strong attraction force, attracting the armature (or drive rod 54) and pushing the friction block 53 with a large positive pressure. Press the brake disc 51 end face; the maximum static friction torque generated at this time for:

[0070]

[0071] in, The coefficient of static friction between friction block 53 and brake disc 51 is given. The effective radius of friction is ensured during design. Much greater than the maximum possible load torque (For example This ensures that the shaft 2 will not slip even slightly under any vehicle vibration environment.

[0072] Hold and Standby: After locking is completed, the control unit can cut off the power supply to motor 31; the system enters standby mode, and the module position is firmly held by the mechanical friction torque of the electromagnetic locking unit, without consuming electrical energy.

[0073] Example 4

[0074] Optionally, based on embodiment 3, this embodiment further integrates a reset mechanism, detection and closed-loop control functions, forming a complete and high-performance adjustment device.

[0075] In this embodiment, a return compression spring 71 is added between the electromagnetic actuator 52 (E-type electromagnet) and the base 1. This spring acts on the movable armature of the electromagnet or the push rod 54 connected to the friction block 53, providing it with an elastic force that always points away from the brake disc 51. When the electromagnet is de-energized, this elastic force... It is sufficient to overcome the residual magnetic force of the armature and the friction between moving parts, ensuring that the friction block 53 can be quickly and reliably separated from the brake disc 51, realizing unlocking upon power failure, and avoiding adjustment delay or jamming caused by any adhesion.

[0076] At the end of the rotating shaft 2, a permanent magnet 61 is coaxially fixedly mounted, constituting the signal generation part of the angle detection unit 6; a Hall sensor 62 is fixedly mounted on the base 1 at a position corresponding to the permanent magnet 61; when the rotating shaft 2 rotates, the direction of the magnetic field of the permanent magnet 61 changes relative to the Hall sensor 62, and the voltage signal output by the sensor changes continuously accordingly; through calibration, this voltage signal has a definite functional relationship with the absolute rotation angle of the rotating shaft 2. This enables non-contact, high-resolution real-time detection of the two-angle pivot.

[0077] A dedicated control unit (which may be a microcontroller MCU) is integrated into the device or is part of the headlight ECU; the input port of the control unit receives angle adjustment commands from the upper system and real-time angle feedback signals from the Hall sensor 62; its output ports are connected to and control the motor driver 31 of the drive unit and the power switch of the electromagnet coil in the electromagnetic locking unit, respectively.

[0078] The complete closed-loop control process is as follows:

[0079] Command parsing and unlocking: The control unit receives the target angle. The control unit outputs a signal to disconnect the power switch of the electromagnet coil, and the electromagnet is de-energized; under the action of the reset spring, the friction block 53 separates from the brake disc 51, and the rotating shaft 2 is unlocked.

[0080] Closed-loop control: The control unit reads the current value from Hall sensor 62 to obtain the actual angle. ; Calculate the angle deviation According to the deviation The size and direction are determined by using PID or other control algorithms to calculate the control quantity (such as PWM duty cycle) required by motor 31, and drive motor 31 to rotate.

[0081] Position determination and locking: During the adjustment process, the control unit continuously compares... and When the conditions for arrival are met (such as...) ,in When the preset small angle tolerance (e.g., 0.02°) is met, the adjustment is determined to be in place; the control unit immediately outputs a signal to close the power switch of the electromagnet coil, the electromagnet is energized, the friction block 53 presses the brake disc 51, and a rigid lock is achieved.

[0082] Status confirmation and completion: After the locking action is completed, the control unit can read the angle sensor signal again after a short delay to confirm that the angle has not changed after locking. Then, the motor 31 drive is turned off and the "adjustment completed" status is reported to the system. The entire adjustment-locking cycle can be controlled within 100-300 milliseconds.

[0083] This embodiment ensures the reliability of unlocking by integrating a reset spring, achieves high-precision closed-loop control through the angle detection unit 6, and intelligently coordinates the drive and locking logic through the control unit, ultimately realizing the adjustment function of "fast, accurate, quiet and secure".

[0084] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A low beam module adjustment device, characterized in that: include: Base (1); The rotating shaft (2) is rotatably connected to the base (1), and one end of it is connected to the near-light optical module; The driving unit is fixed on the base (1); A flexible transmission unit is connected between the output end of the drive unit and the rotating shaft (2) to convert the rotational motion output by the drive unit into a torque acting on the rotating shaft (2); An electromagnetic locking unit is disposed on the base (1) and cooperates with the rotating shaft (2); The flexible transmission unit includes a retractable flexible transmission element that does not transmit pushing force; the electromagnetic locking unit is configured to generate magnetic force when energized to act directly on the rotating shaft (2) to form a friction pair that restricts the rotation of the rotating shaft (2); when de-energized, the magnetic force is eliminated and the friction pair is separated.

2. The low beam module adjustment device according to claim 1, characterized in that: The flexible transmission element is a metal belt (41); the driving unit includes a motor (31) and a reel (32) driven by the motor (31), with one end of the metal belt (41) wound and fixed on the reel (32).

3. The low beam module adjustment device according to claim 2, characterized in that: The flexible transmission unit also includes a worm spring box (42), which is fixed on the rotating shaft (2); the other end of the metal strip (41) is connected to the outer end of the worm spring inside the worm spring box (42), and the inner end of the worm spring is fixed on the worm spring box (42).

4. The low beam module adjustment device according to claim 1, characterized in that: The electromagnetic locking unit includes: Brake disc (51) is coaxially and fixedly connected to the rotating shaft (2); An electromagnetic actuator (52) is fixed on the base (1), and a friction block (53) is provided at its end near the brake disc (51). The electromagnetic actuator (52) is configured to drive the friction block (53) to press against the end face or circumferential face of the brake disc (51) when energized, thereby forming the friction pair.

5. The low beam module adjustment device according to claim 4, characterized in that: It also includes a reset elastic element (7) that acts on the moving part of the friction block (53) or the electromagnetic actuator (52) to provide a tendency force to separate the friction block (53) from the brake disc (51).

6. The low beam module adjustment device according to any one of claims 1-5, characterized in that: It also includes an angle detection unit (6) for detecting the rotation angle of the rotating shaft (2).

7. The low beam module adjustment device according to claim 6, characterized in that: It also includes a control unit, which is electrically connected to the drive unit, the electromagnetic locking unit and the angle detection unit (6) respectively; The control unit is configured to: when receiving an angle adjustment command, first control the electromagnetic locking unit to de-energize and release the rotating shaft (2), then control the drive unit to run so as to drive the rotating shaft (2) to rotate to the target angle through the flexible transmission unit, and then control the electromagnetic locking unit to energize to lock the rotating shaft (2).

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