A device and method for measuring a pre-set clearance angle of a brake clearance adjustment arm of a vehicle

Abstract

In order to solve the problem of poor preset gap angle detection accuracy of brake gap adjusting arm, the application provides a kind of automobile brake gap adjusting arm preset gap angle measuring device and method, including main worm wheel fixing device, the hexagonal head fixing device for fixing and detecting the main worm hexagonal head of brake gap adjusting arm, adjusting arm body fixing device, the driving device for adjusting arm control ring and driving control ring rotation and detecting the rotation angle and torque in the process of rotation, the main worm wheel fixing device includes the fixing assembly for fixing the main worm wheel of brake gap adjusting arm and the position is adjustable in the height direction, the adjusting arm body fixing device drives brake gap adjusting arm body to rotate around the main worm wheel axis by setting torque applying assembly to apply a certain torque, by the above device and method, the interference of unnecessary gap and friction is eliminated to the greatest extent, and the accuracy of preset gap angle measurement of the measured piece is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a device and method for measuring the preset clearance angle of an automotive brake clearance adjustment arm. Background Technology

[0002] In heavy-duty vehicle braking, the brake clearance adjusting arm is a key component responsible for transmitting torque and adjusting the brake clearance. The size of the brake clearance directly affects the vehicle's braking performance and safety. When the brake clearance is too small, it can easily cause the brake wear temperature to rise, which may lead to fire or tire blowout in severe cases. When the brake clearance is too large, the braking force will decrease, resulting in an excessively long braking distance and inability to stop, both of which can easily lead to serious safety accidents. The preset clearance angle of the brake clearance adjusting arm is closely related to the brake clearance. It determines the initial inherent clearance between the brake drum and the brake pads. That is, under any circumstances, the brake clearance should always maintain a certain value to ensure braking safety and performance. This certain value is determined by the preset clearance angle of the brake clearance adjusting arm. Therefore, verifying the accuracy of this angle is very important.

[0003] Currently, the types and quantities of equipment for detecting the preset clearance angle of automotive brake clearance adjusting arms are limited in the industry. The existing methods use a fixed adjusting arm worm gear, a lever to rotate the control ring, and the torque change is detected to calculate the angle value as the preset clearance angle. However, this process does not eliminate the influence of various clearances of the brake clearance adjusting arm on the test results, does not consider the effect of friction, and lacks a clear definition of the torque value. In actual testing, the installation method and testing method of the brake clearance adjusting arm have issues with rationality, and the experimental logic is not rigorous enough. This results in poor consistency of the output preset clearance angle, with a large difference from the design value, leading to the abandonment of equipment by some manufacturers and causing economic losses. The measurement of the preset clearance angle should be obtained by detecting the rotational torque and angle of the brake clearance adjusting arm control ring through meticulous testing methods and calculations. This is the most direct and convenient method without disassembling the brake clearance adjusting arm. Summary of the Invention

[0004] To address the issues of poor accuracy in detecting the preset clearance angle of the brake clearance adjusting arm and the lack of rigor and logic in the testing method, this invention provides a device and method for measuring the preset clearance angle of an automotive brake clearance adjusting arm. The technical solution adopted is as follows:

[0005] A device for measuring the preset clearance angle of an automotive brake clearance adjusting arm, characterized in that it comprises:

[0006] The main worm gear fixing device includes a fixing component for fixing to the internal teeth of the main worm gear, and the fixing component is adjustable in the height direction;

[0007] A worm gear hexagonal head fixing device includes a first fixed bracket, a connecting plate, and a worm gear hexagonal head clamp. The first fixed bracket and the brake clearance adjusting arm are axially adjustable in the main worm gear. The connecting plate is adjustablely connected to the first fixed bracket in the height direction. The worm gear hexagonal head clamp is fixedly connected between the worm gear hexagonal head and the connecting plate. The connecting plate is rotatably connected to the first fixed bracket along a longitudinal plane parallel to the main worm gear axis to drive the worm gear hexagonal head clamp to be coaxially connected with the worm gear hexagonal head. Furthermore, a first angle encoder and a tightening assembly are provided between the worm gear hexagonal head clamp and the connecting plate. The first angle encoder is fixedly connected between the worm gear hexagonal head clamp and the connecting plate. The tightening assembly is used to tighten or loosen the connecting plate and the first angle encoder. In the loosened state, the worm gear hexagonal head clamp rotates with the brake clearance adjusting arm and the main worm gear.

[0008] The adjusting arm body fixing device includes a fixing plate and a torque applying component connected between the fixing plate and the brake gap adjusting arm body. The fixing plate is adjustablely connected to the main worm gear fixing device along an axis parallel to the brake ring. The output end of the torque applying component is connected to the brake gap adjusting arm body and is used to drive the brake gap adjusting arm body to rotate around the main worm gear axis.

[0009] The driving device includes a second fixed bracket, a servo motor, and a tensioning sleeve. The axial position of the main worm gear of the second fixed bracket and the fixed assembly is adjustable along the brake gap adjustment arm. The servo motor is fixedly connected to the second fixed bracket, and its output shaft is fixedly connected to the control ring through the tensioning sleeve. A detection assembly for detecting the rotation angle and torque of the control ring is also provided between the servo motor and the tensioning sleeve. A circumferential limiting device for limiting the relative rotation of the two along the circumferential direction of the inner circle of the control ring is connected between the tensioning sleeve and the control ring.

[0010] Furthermore, the main worm gear fixing device includes a base plate, a side plate, and a fixing assembly. The side plate is fixedly connected to the top of the base plate. The fixing assembly consists of an adjusting base and an adjusting arm spline shaft. A height adjustment mechanism is connected between the adjusting base and the side plate. The length of the adjusting arm spline shaft is distributed along a direction parallel to the axis of the main worm gear. One end of the shaft is fixedly connected to the adjusting base, and the other end is fixedly connected to the internal gear of the main worm gear.

[0011] Furthermore, the height adjustment mechanism includes an adjustment plate, a height adjustment bolt, and a sliding guide mechanism disposed between the adjustment base and the side plate. The adjustment plate is fixedly connected to the top of the side plate, the length of the height adjustment bolt is distributed along the height direction and is threadedly connected to the adjustment plate, and the lower end of the height adjustment bolt abuts against the upper end of the adjustment base.

[0012] Furthermore, a first guide rail is provided below the base plate, the length of the first guide rail is distributed along a direction parallel to the axis of the main worm gear, and the base plate slides along the length direction of the first moving guide rail.

[0013] Furthermore, the connecting plate includes a bracket mounting plate and a clamp mounting plate vertically fixedly connected to the bracket mounting plate. The bracket mounting plate is adjustablely connected to the first fixed bracket along the height direction. The worm hexagonal head clamp is detachably fixedly connected between the worm hexagonal head and the clamp mounting plate. The bracket mounting plate can be rotatably connected to the first fixed bracket along a longitudinal plane parallel to the axis of the main worm to drive the worm hexagonal head clamp on the clamp mounting plate to be coaxially distributed with the main worm.

[0014] Furthermore, the worm gear hexagonal head clamp includes a clamp housing, a clamping assembly, and an adjusting bolt. The inner wall of the clamp housing is circumferentially spaced with multiple sets of mounting seats. The clamping assembly consists of multiple sets of connecting seats corresponding to the mounting seats, a fixed shaft fixedly connected between two adjacent connecting seats, and a clamping contact rotatably connected to the fixed shaft. The correspondingly distributed mounting seats and connecting seats are detachably and fixedly connected. The clamping contact, at its connection to the rotating shaft and near the worm gear hexagonal head, is provided with a locking mechanism that mates with the worm gear hexagonal head. The unit has an abutment portion at one end away from the hexagonal head of the worm gear, which mates with the adjusting bolt. One axial end of the adjusting bolt is abutted against the abutment portion, and the other end is detachably fixed to the clamp mounting plate. A spring piece is provided between the abutment portion of the clamping hand and the inner wall of the clamp housing. One end of the spring piece is fixed to the inner wall of the clamp housing, and the other end abuts against the outer side of the abutment portion of the clamping hand. The first angle encoder is coaxially fixed to the adjusting bolt, and the tightening assembly has a stop-rotation nut, which is threadedly connected to the adjusting bolt.

[0015] Furthermore, the first fixed bracket is provided with a third elongated hole distributed along the height direction, the bracket mounting plate is distributed along the longitudinal plane parallel to the axis of the main worm gear, and the bracket mounting plate is provided with arc-shaped holes corresponding to the positions of the third elongated holes on the first fixed bracket.

[0016] Furthermore, the torque application assembly consists of a cylinder connecting seat, a cylinder, a tension sensor, and a U-shaped fork. A cylinder mounting base is fixedly connected to the side of the fixing plate near the brake gap adjusting arm. The cylinder mounting base is adjustablely fixed to the side of the fixing plate near the brake gap adjusting arm along the height direction. The cylinder body is rotatably connected to the cylinder mounting base through the cylinder connecting seat. The cylinder piston rod axis is distributed along the main worm gear axis parallel to the brake gap adjusting arm, and one end of the piston rod is fixedly connected to the brake gap adjusting arm body through the U-shaped fork. The cylinder connecting seat and the cylinder mounting base are rotatably connected.

[0017] Furthermore, the fixing plate is provided with a fourth elongated hole distributed along the height direction, and the cylinder mounting base is provided with mounting holes distributed corresponding to the positions of the fourth elongated hole.

[0018] Furthermore, the detection component includes a torque limiter, a torque sensor, and an angle encoder. The second fixed bracket is provided with two sets of mounting plates spaced apart along the axial direction of the control ring. The torque limiter, torque sensor, and angle encoder are sequentially and coaxially fixedly connected and rotatably connected between the two sets of mounting plates. The servo motor is fixedly connected to the second fixed bracket, and its output shaft is coaxially and fixedly connected to the torque limiter. The end of the angle encoder near the brake ring is connected to the control ring connection assembly.

[0019] Furthermore, the circumferential limiting device includes an adjusting lever and a lever adjusting arm. The lever adjusting arm is fixedly connected to the tensioning sleeve. The lever adjusting arm is provided with lever adjusting holes whose length is distributed along the rotation plane parallel to the control ring. The length direction of the adjusting lever is distributed along the axis parallel to the control ring. One end of the adjusting lever is adjustablely fixedly connected to the lever adjusting arm along the length direction of the lever adjusting hole, and the other end is detachably fixedly connected to the control ring.

[0020] Furthermore, a second guide rail is provided below the second fixed bracket, the length of the second guide rail is distributed along the control ring axis of the brake gap control arm, and the second fixed bracket slides along the length of the second guide rail.

[0021] A method for measuring the preset clearance angle of an automotive brake clearance adjusting arm, based on the aforementioned automotive brake clearance adjusting arm preset clearance angle measuring device, is characterized by comprising the following steps:

[0022] S1. The main worm gear fixing device is used to install and fix the brake clearance adjusting arm. The fixing component is fixedly connected to the main worm gear of the brake clearance adjusting arm and adjusted to a suitable height.

[0023] S2. Adjust the rotation center of the drive device to be basically aligned with the center of the control ring of the brake gap adjusting arm, and fix the control ring connecting assembly of the drive device to the inner circle of the control ring of the brake gap adjusting arm to achieve complete alignment, and fix the expansion sleeve to the control ring through the circumferential limiting device.

[0024] S3. Connect the adjusting arm body fixing device to the brake clearance adjusting arm body, and apply torque to the brake clearance adjusting arm body using the torque applying component to eliminate the free clearance between the main worm gear and the main worm, the clearance between the brake clearance adjusting arm body and the main worm gear, and the clearance between the main worm gear and the fixing component.

[0025] S4. Install and fix one side of the hexagonal head of the main worm using the hexagonal head fixing device. Adjust the hexagonal head clamp and the hexagonal head of the worm using the hexagonal head clamp, connecting plate and clearance shim to eliminate the gap between the main worm and the hexagonal head clamp.

[0026] S5. Adjust the tightening assembly to loosen the worm hexagonal head clamp from the connecting plate. Drive the control ring to rotate via the servo motor, which in turn drives the pinion assembly and worm to rotate. When the first angle encoder detects a change in the worm hexagonal head rotation angle, it controls the servo motor to stop rotating and records the torque at this time as the initial torque M.

[0027] S6. Tighten the hexagonal head clamp of the worm gear to the connecting plate using the tightening assembly so that the main worm gear cannot rotate. Drive the control ring to rotate from any position along the rotation direction in step S5 through the servo motor. When the rotation reaches the initial torque M, stop the servo motor rotation and control the servo motor to rotate in the opposite direction. Record the rotation angle and torque values ​​during the rotation process and form a curve showing the relationship between rotation angle and rotation torque.

[0028] S7. After rotating to N peaks, stop the test and calculate the theoretical preset clearance angle = ∠AB - (∠BC + ∠CD + ∠DE + … ∠N) / N based on the rotation angle - rotation torque relationship curve, where:

[0029] ∠AB is the preset clearance angle plus the angle of one ratchet tooth of the clutch worm gear pinion;

[0030] ∠BC is the angle at which the small gear of the clutch worm rotates past the second ratchet tooth;

[0031] ∠CD is the angle at which the small gear of the clutch worm rotates past the third ratchet tooth;

[0032] ∠DE is the angle at which the clutch worm pinion rotates past the fourth ratchet tooth;

[0033] ∠N is the angle at which the clutch worm pinion rotates through the Nth ratchet tooth.

[0034] The beneficial effects of this invention are as follows:

[0035] 1. The relative positional relationship between the main worm gear fixing device and the drive device can be adjusted by the first guide rail and the second guide rail respectively, thereby realizing the connection between the fixing component and the expansion sleeve and the brake clearance adjusting arm. In addition, the height adjustment mechanism drives the fixing component to move up and down to ensure the centering installation of the brake clearance adjusting arm and avoid the influence of friction and clearance caused by misalignment on the test results.

[0036] 2. By applying torque to the brake clearance adjusting arm housing through the torque application component in the brake clearance adjusting arm body fixing device, the clearance between the main worm wheel and the main worm can be effectively eliminated, and the clearance between the brake clearance adjusting arm housing and the main worm wheel can also be eliminated simultaneously, as well as the clearance between the main worm wheel and the adjusting arm spline shaft in the circumferential direction of the main worm wheel.

[0037] 3. A worm gear hexagonal head clamp is used to fix and clamp the worm gear hexagonal head of the brake clearance adjusting arm. The worm gear hexagonal head clamp in this solution can tightly clamp the worm gear hexagonal head to avoid excess clearance. Moreover, the worm gear hexagonal head clamp and the first angle encoder are fixed on the brake clearance adjusting arm through the connecting plate. The installation angle of the worm gear hexagonal head clamp can be adjusted through the first arc hole provided on the bracket mounting plate to make the worm gear hexagonal head clamp coaxial with the worm of the brake clearance adjusting arm, so as to avoid the influence of friction and internal stress.

[0038] 4. A gap shim is set between the worm hexagonal head clamp and the end face of the brake clearance adjusting arm where the worm hexagonal head is located to ensure that a certain gap is left between the two, so as to prevent the worm hexagonal head clamp from being tightly attached to the brake clearance adjusting arm housing during installation, and to avoid the friction generated during the testing process from affecting the initial rotation torque of the worm.

[0039] 5. After the adjusting bolt passes through the first angle encoder, it is clamped to the hexagonal head of the worm through the clamping contact. While fixing the hexagonal head of the worm, the rotation angle of the worm can be measured by the first angle encoder. Moreover, the adjusting bolt is equipped with an anti-rotation nut. Tightening the anti-rotation nut can prevent the adjusting bolt from rotating, thus avoiding the problem of inaccurate angle measurement caused by the rotation of the worm when the rotation control ring reaches the initial rotation torque.

[0040] 6. By using a shrink sleeve tightly attached to the inner wall of the control ring, the control ring of the adjusting arm is supported on the center of rotation. This can avoid the gaps and friction between the control ring and the cover plate, and between the control ring and the pinion on the pinion assembly, from affecting the peak and characteristic values ​​of the torque during rotation, thus affecting the angle calculation.

[0041] 7. The adjustment lever can be adjusted along the length of the adjustment hole on the lever adjustment arm to adjust the installation position of the adjustment lever. Furthermore, by connecting the adjustment lever with the control ring fixing hole on the adjustment lever with bolts, the position of the adjustment lever in the axial direction of the control ring can be adjusted to fit the control ring. This method is applicable to fixing the control ring of the brake clearance adjustment arm of different product models.

[0042] 8. In the brake clearance adjusting arm body fixing device, the position of the torque applying component in the worm gear axis can be adjusted through the second elongated hole, and the position of the torque applying component in the height direction can be adjusted through the fourth elongated hole to match different models of brake clearance adjusting arms;

[0043] 9. In the torque loading assembly, the cylinder is connected to the cylinder mounting base via a cylinder connecting seat. The cylinder and the cylinder connecting seat can rotate along the rotating pin on the cylinder mounting base. When the cylinder applies force to the brake clearance adjusting arm, the direction of the force is at an obtuse or acute angle with the brake clearance adjusting arm to prevent internal stress from being generated and affecting the applied force value. This effectively eliminates the free clearance between the main worm and the main worm wheel, and avoids affecting the measurement of the preset clearance angle.

[0044] 10. This solution effectively improves the accuracy of test results by eliminating friction and gaps that may affect the accuracy of the test and minimizing interference from irrelevant factors. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of the present invention.

[0046] Figure 2 Schematic diagram of the main worm gear fixing device

[0047] Figure 3 Schematic diagram of the hexagonal head fixing device for worm gear

[0048] Figure 4 Schematic diagram of the hexagonal head clamp for worm gears

[0049] Figure 5 Schematic diagram of the fixture housing structure

[0050] Figure 6 Schematic diagram of the clamping tentacle structure

[0051] Figure 7 Schematic diagram of the clamping component structure

[0052] Figure 8 Schematic diagram of the connection structure between the clamp housing and the clamping assembly

[0053] Figure 9 Schematic diagram of the gap gasket structure

[0054] Figure 10 Schematic diagram of the arm body fixing device for adjustment

[0055] Figure 11 Schematic diagram of the drive device structure

[0056] Figure 12 Schematic diagram of the lever adjustment arm structure

[0057] Figure 13 Schematic diagram of the adjustment lever structure

[0058] Figure 14 Theoretical curve of torque versus rotation angle for brake clearance adjusting arm control ring

[0059] Wherein, 1-base plate, 101-first elongated hole, 102-second elongated hole, 103-notch;

[0060] 2-Side upright plate, 201-Guide groove, 202-Adjustment base mounting hole;

[0061] 3-Adjusting base, 301-Adjusting plate, 302-Fixed flange, 303-Adjusting arm spline shaft, 304-Adjusting arm support disc, 305-Adjusting plate, 306-Height adjusting bolt, 307-Guide key, 308-Fasting bolt;

[0062] 4-First fixed bracket, 401-Third elongated hole, 402-First base plate mounting hole;

[0063] 5-Connecting plate, 501-Bracket mounting plate, 502-First arc hole, 503-Clamp mounting plate, 504-Second arc hole;

[0064] 6-Worm gear hexagonal head clamp, 601-Clamp housing, 602-Fixing nut, 603-Adjusting bolt, 604-Anti-rotation nut, 605-Gap washer, 606-Clamping contact, 607-Rotating hole, 608-Abutting part, 609-Snap-fitting part, 6010-Rotating shaft, 6011-Connecting block, 6012-Fixing seat, 6013-Fixing bolt, 6014-Spring piece, 6015-Conical head;

[0065] 7 - First Angle Encoder;

[0066] 8-Fixing plate, 801-Fourth elongated hole, 802-Second base plate mounting hole;

[0067] 9-Cylinder mounting base, 901-Rotating pin, 10-Cylinder connecting seat, 11-Cylinder, 12-Tension / compression sensor, 13-U-shaped fork, 1301-Adjusting arm pin;

[0068] 14-Second fixed bracket, 1401-End face bearing, 15-Servo motor, 16-Torque limiter, 17-Torque sensor, 18-Second angle encoder, 19-Transition bushing, 20-Tightening sleeve.

[0069] 21-Toggle lever adjusting arm, 2101-Fixing bolt hole, 2102-Through hole, 2103-Toggle lever adjusting hole;

[0070] 22-Adjusting lever, 2201-Externally threaded lever, 2202-Control ring fixing hole;

[0071] 23-Turn lever adjusting nut, 24-Turn lever tightening nut, 25-Control ring fixing bolt, 26-First guide rail, 27-First locking handle, 28-Second guide rail, 29-Second locking handle, 30-Brake clearance adjusting arm. Detailed Implementation

[0072] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0073] In the description of the invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the view direction or positional relationship, and are only for the convenience of describing the invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the invention.

[0074] like Figure 1 As shown, a device for measuring the preset clearance angle of an automotive brake clearance adjusting arm includes a main worm gear fixing device, a worm hexagon head fixing device, an adjusting arm body fixing device, and a drive device. The main worm gear fixing device is adjustable in position along the axis of the main worm and includes a fixing component for fixing the main worm gear of the brake clearance adjusting arm. The fixing component is adjustable in height. The worm hexagon head fixing device is used to fix and detect the hexagon head of the main worm gear of the brake clearance adjusting arm. The adjusting arm body fixing device drives the brake clearance adjusting arm body to rotate around the axis of the main worm gear through a torque applying component to apply a certain torque to the brake clearance adjusting arm body. The drive device is used to drive the control ring to rotate and detect the rotation angle and torque during the rotation process for calculating the preset clearance angle.

[0075] Main worm gear fixing device such as Figure 1 and Figure 2 As shown, the device includes a fixing assembly, which consists of a base plate 1, a side plate 2, and an adjustment base 3. The base plate 1 is horizontally distributed, the side plate 2 is fixedly connected to the middle of the right side above the base plate 1, and the adjustment base 3 is connected to the left side of the side plate 2. A height adjustment mechanism is provided between the adjustment base 3 and the side plate 2 to adjust the height position of the adjustment base 3 on the side plate 2.

[0076] Specifically, the base plate 1 has a first elongated hole 101 and a second elongated hole 102 at its front and rear ends, respectively, both of which are horizontally distributed along the left and right directions. A first guide rail 26 is provided below the base plate 1, and the length of the first guide rail 26 is distributed along the axis of the main worm gear parallel to the brake clearance adjusting arm. The base plate 1 is slidably connected to the ground above through the first guide rail 26, and a first locking handle 27 is provided on the first guide rail 26 to fix the position of the base plate 1 on the first guide rail 26. The side uprights 2 are vertically distributed along the height direction. The adjusting base 3 consists of an adjusting plate 301, a fixing flange 302, and an adjusting arm spline shaft. Composed of 303, the adjusting plate 301 is parallel to the left side of the side plate 2. The fixing flange 302 is detachably fixed to the left side of the adjusting plate 301 by bolts. The adjusting arm spline shaft 303 is fixedly connected to the left side of the fixing flange 302. The left end of the adjusting arm spline shaft 303 is fixedly connected to the internal gear of the main worm gear on the brake clearance adjusting arm. An adjusting arm support disc 304 is also coaxially fixedly connected to the adjusting arm spline shaft 303. The adjusting arm support disc 304 fits against the opposite side of the brake clearance adjusting arm away from the brake ring, thereby fixing the brake clearance adjusting arm. The height adjustment... The mechanism includes a guide key 307 and a guide groove 201. The guide groove 201 is located on the left side of the side plate 2 and its length is distributed vertically. The guide key 307 is fixedly connected to the right side of the adjustment plate 301 and slides up and down in cooperation with the guide groove 201. The adjustment plate 301 can slide up and down along the side plate 2 through the cooperation of the guide key 307 and the guide groove 201. An adjustment plate 305 is also fixedly connected above the adjustment plate 301. A height adjustment bolt 306 is threaded onto the adjustment plate 305. The height adjustment bolt 306 has its length distributed vertically, and its lower end abuts against the side plate 2. At the upper end, and on the side plate 2, there are four sets of adjustment base mounting holes 202. The adjustment base mounting holes 202 are all elongated holes distributed along the height direction. The adjustment plate 301 is provided with mounting holes that are distributed in the same position as the adjustment base mounting holes 202. By rotating the height adjustment bolt 306, the adjustment plate 301 and the adjustment arm spline shaft 303 can be driven to slide along the height direction of the side plate 2. After the height adjustment is completed, the fastening bolt 308 is passed through the adjustment base mounting holes 202 and the mounting holes on the adjustment plate 301 to fix it, thereby completing the height adjustment of the adjustment base 3.

[0077] Worm gear hexagonal head fixing device such as Figure 1 , Figures 3-9 As shown, it comprises a first fixed bracket 4, a connecting plate 5, a worm gear hexagonal head clamp 6, and a first angle encoder 7. The worm gear hexagonal head clamp 6 is fixedly connected between the first fixed bracket 4 and the main worm gear hexagonal head of the brake clearance adjusting arm through the connecting plate 5. The first angle encoder 7 is fixedly connected between the worm gear hexagonal head clamp 6 and the connecting plate 5.

[0078] Specifically, the first fixed bracket 4 is provided with a third elongated hole 401 distributed along the height direction, and a first base plate mounting hole 402 is provided at the lower end. The first base plate mounting hole 402 is an elongated hole distributed along the left and right direction, and its position corresponds to the position of the first elongated hole 101. The first fixed bracket 4 can slide left and right along the first elongated hole 101 on the base plate 1, and the two are fixed by bolts passing through the first base plate mounting hole 402 and the first elongated hole 101.

[0079] The connecting plate 5 has an overall L-shaped structure, consisting of a bracket mounting plate 501 and a clamp mounting plate 503 vertically fixed to the bracket mounting plate 501. The bracket mounting plate 501 is distributed along the Z-axis plane parallel to the axis of the main worm gear. The bracket mounting plate 501 is provided with two sets of first arc holes 502 for engaging with the third elongated hole 401. Through the first arc holes 502, the connecting plate 5 can be rotated and adjusted along the plane of the bracket mounting plate 501 to ensure that the worm hexagonal head clamp and the main worm gear are coaxially distributed. After adjustment, the bracket mounting plate 501 and the first fixed bracket 4 are fixed with bolts. The clamp mounting plate 503 is distributed along the Z-axis plane parallel to the axis of the main worm gear. The clamp mounting plate 503 is provided with four sets of second arc holes 504 for mounting the first angle encoder 7.

[0080] The worm gear hexagonal head clamp 6 consists of a clamp housing 601, a clamping assembly disposed inside the clamp housing 601, an adjusting bolt 603, and an anti-rotation nut 604. Multiple sets of evenly spaced fixing seats 6012 are fixedly connected circumferentially to the inner wall of the clamp housing 601. The clamping assembly consists of clamping contacts 606, a rotating shaft 6010, and a connecting block 6011. Multiple sets of clamping contacts 606 are provided, evenly spaced along the circumferential direction of the inner wall of the clamp housing 601. The length of the clamping contacts 606 is distributed parallel to the axis of the main worm gear and close to the hexagonal head of the worm gear. One end of the head is a snap-fit ​​part 609, which can be clamped to the outer wall of the hexagonal head of the worm gear. The end away from the hexagonal head of the worm gear is an abutment part 608. A rotating hole 607 is provided in the middle of the length direction of the clamping contact 606. A rotating shaft 6010 is rotatably connected in each rotating hole 607. Two adjacent sets of rotating shafts 6010 are fixedly connected and a set of connecting blocks 6011 is fixedly connected to each other. The number and position of the connecting blocks 6011 correspond to multiple sets of fixed seats 6012. The connecting blocks 6011 and the fixed seats 6012 are provided with mounting holes distributed in corresponding positions. The two are fixed by fixing bolts 6013. A fixed connection is made to secure the clamping assembly to the inner wall of the clamp housing 601. A fixing nut 602 is coaxially fixed to the end of the clamp housing 601 away from the hexagonal head of the worm gear. An adjusting bolt 603 is threadedly connected to the fixing nut 602 and can move axially within the clamp housing 601, allowing adjustment of the axial position of the adjusting bolt 603 within the clamp housing 601. The end of the adjusting bolt 603 near the hexagonal head of the worm gear is a tapered head 6015, used to engage with the abutment portion 608 on the clamping contact 606. The clamping contact 606 and the clamp... A spring piece 6014 is also provided between the inner walls of the housing 601. One end of the spring piece 6014 is fixedly connected to the inner wall of the clamp housing 601, and the other end abuts against the outer side of the abutment part 608. By adjusting the bolt 603 moving axially in the clamp housing 601, the cone head 6015 can be driven to cooperate with the abutment part 608 to drive the clamping contact 606 to rotate along the rotating shaft 6010, thereby driving the snap-fit ​​part 609 of the clamping contact 606 to open or close, thereby realizing the loosening or clamping action of the worm gear hexagonal head. Moreover, the adjusting bolt 603 is coaxially fixedly connected to the first angle encoder 7.

[0081] During installation, the end of the adjusting bolt 603 away from the worm gear hexagonal head passes through the through hole on the first angle encoder 7 and then through the clamp mounting plate 503. The first angle encoder 7 is fixed to the adjusting bolt 603 and tightened onto the clamp mounting plate 503 by the anti-rotation nut 604. Moreover, one end of the first angle encoder 7 is fixed to the second arc hole 504 of the clamp mounting plate 503 by bolts. Through the second arc hole 504, the first angle encoder 7 can rotate a certain angle, which facilitates the installation of the first angle encoder 7. The worm gear hexagonal head clamp 6 moves up and down along the third elongated hole 401 on the first fixed bracket 4 through the bracket mounting plate 501 and matches the appropriate installation angle through the first arc hole 502, thereby adapting to different rotation angles of the brake clearance adjusting arm 30.

[0082] In addition, the worm gear hexagonal head fixing device also includes a clearance shim 605, the clearance shim 605 having the following structure: Figure 9 As shown, an opening is provided for engaging with the hexagonal head of the worm gear. A clearance shim 605 is provided between the hexagonal head clamp 6 of the worm gear and the end face of the brake clearance adjusting arm where the hexagonal head of the worm gear is located. By providing the clearance shim 605, a certain gap can be maintained between the hexagonal head clamp 6 of the worm gear and the brake clearance adjusting arm 30, so as to avoid the friction generated by the contact between the hexagonal head clamp 6 of the worm gear and the brake clearance adjusting arm 30 during the testing process, which would affect the test results.

[0083] Adjust the arm body fixing device, such as Figure 1 , Figure 2 , Figure 10 As shown, the assembly includes a fixing plate 8, a cylinder mounting base 9, a cylinder connecting seat 10, a cylinder 11, a tension / compression sensor 12, and a U-shaped fork 13. The fixing plate 8 has an L-shaped structure, with a fourth elongated hole 801 distributed along the height direction at the upper part, and a second base plate mounting hole 802 corresponding to the position of the second elongated hole 102 at the lower end. The second base plate mounting hole 802 is an elongated hole distributed along the left-right direction. The fixing plate 8 can be moved left and right along the length direction of the second elongated hole 102 to adjust its position, and the two are fixed by bolts passing through the second base plate mounting hole 802 and the second elongated hole 102. The cylinder mounting base 9 has... The cylinder mounting base 9 is provided with mounting holes corresponding to the position of the fourth elongated hole 801. The mounting position of the cylinder mounting base 9 can be adjusted along the length direction of the fourth elongated hole 801, and the two are fixed by bolts. The cylinder connecting seat 10 is rotatably connected to the cylinder mounting base 9 via a rotating shaft pin 901. The cylinder body of the cylinder 11 is fixedly connected to the cylinder connecting seat 10. The piston rod axis is distributed along the front-back direction in the view direction, that is, along the direction parallel to the main worm axis. The tension and compression sensor 12 is fixedly connected between the piston rod of the cylinder 11 and the U-shaped fork 13. The U-shaped fork 13 is fixedly connected to the brake clearance adjusting arm body via an adjusting arm pin 1301.

[0084] By adjusting the cylinder 11 in the arm body fixing device, a certain torque can be applied to the brake clearance adjusting arm body, which can simultaneously eliminate the free clearance between the worm wheel and worm on the brake clearance adjusting arm and the clearance between the brake clearance adjusting arm housing and the main worm wheel. Furthermore, the cooperation between the adjusting arm body fixing device and the main worm wheel fixing device can eliminate the clearance between the main worm wheel and the fixing component, preventing the above clearances from affecting the measurement results, thereby improving the measurement accuracy.

[0085] Drive device such as Figure 1 , Figures 11-13 As shown, it includes a second fixed bracket 14, a servo motor 15, a torque limiter 16, a torque sensor 17, a second angle encoder 18, a tension sleeve 20, and a circumferential limiting device, wherein the circumferential limiting device includes a lever adjustment arm 21 and an adjustment lever 22.

[0086] Specifically, the second fixed bracket 14 has a U-shaped plate structure, and the two side plates of its U-shaped structure are spaced apart along the axis of the control ring of the brake clearance adjusting arm. Figure 1 The components are distributed in a left-right direction, and end face bearings 1401 are provided on both side plates. The servo motor 15 is fixedly connected to the left side plate of the second fixed bracket 14, and its output shaft is rotatably connected to the left side plate through the end face bearing 1401. The torque limiter 16, torque sensor 17, and second angle encoder 18 are coaxially fixedly connected and located between the left and right side plates of the second fixed bracket 14. One end of the torque limiter 16 is coaxially fixedly connected to the output shaft of the servo motor 15. The right end of the main shaft of the second angle encoder 18 is coaxially rotatably connected to the right side plate of the second fixed bracket 14 through the end face bearing 1401. The main shaft of the second angle encoder 18 passes through the right side plate of the second fixed bracket 14 to the right and is coaxially fixedly connected to the transition sleeve 19 and the tightening sleeve 20. One end of the tightening sleeve 20 is tightly fitted with the inner circle of the control ring of the brake gap adjusting arm. The lever adjusting arm 21 is fixedly connected to the left side of the tightening sleeve 20. Figure 12 As shown, the upper part of the lever adjusting arm 21 is provided with a through hole 2102 for coaxial fixed engagement with the outer surface of the expansion sleeve 20 and a fixing bolt hole 2101 for fixing with the expansion sleeve 20, and the lower part is provided with a lever adjusting hole 2103. The length of the lever adjusting hole 2103 is distributed along the plane parallel to the control ring. The adjusting lever 22 is as follows: Figure 13As shown, its length is distributed parallel to the axis of the control ring, including an externally threaded lever 2201 and a control ring fixing hole 2202. One end of the externally threaded lever 2201 is located inside the lever adjustment hole 2103 and can slide along the length direction of the lever adjustment hole 2103 to adjust the position of the lever 22 in the length direction of the lever adjustment arm 21. Moreover, the externally threaded lever 2201 is threaded with a lever adjustment nut 23 and a lever tightening nut 24. The lever adjustment nut 23 and the lever tightening nut 24 are located on the left and right sides of the lever adjustment arm 21, respectively. The nut 23 and the lever tightening nut 24 can tighten and fix the adjusted lever 22 and lever adjusting arm 21 after the position adjustment is completed; the control ring fixing hole 2202 is located at the end of the adjusted lever 22 near the control ring, and its length is distributed in a direction parallel to the axis of the control ring. The control ring fixing hole 2202 is fixedly connected to the through hole on the control ring of the brake gap adjusting arm 30 by the control ring fixing bolt 25. The control ring fixing bolt 25 passes through the through hole on the control ring from right to left and is threaded to the control ring fixing hole 2202 and tightened, thereby fixing the right end of the adjusted lever 22 to the control ring.

[0087] In addition, a second guide rail 28 is provided below the second fixed bracket 14. The length of the second guide rail 28 is distributed along the left and right direction, that is, along the axis of the control ring. The second guide rail 28 is fixedly connected to the ground. The slider slidably connected to the second guide rail 28 is fixedly connected to the lower end face of the second fixed bracket 14. The left end of the base plate 1 is also provided with a notch 103, which can be used to slide the drive device a certain distance to one side of the base plate 1 to avoid interference between components. The drive device can be adjusted to move in the left and right direction through the second guide rail 28, thereby adjusting the relative positional relationship between the tension sleeve 20 and the control ring in the left and right direction.

[0088] The drive device can eliminate the gap between the control ring and the cover plate, and between the two ratchet teeth in the clutch pinion assembly. This avoids the impact of unexpected friction and sudden changes in rotation angle caused by the gap on the characteristic points of the rotation torque and the detection of the rotation angle. At the same time, the control ring is fixed by adjusting the lever 22 to prevent relative rotation between the control ring and the tension sleeve 20 from affecting the measurement results.

[0089] A method for measuring the preset clearance angle of a vehicle brake clearance adjusting arm, based on the aforementioned vehicle brake clearance adjusting arm preset clearance angle measuring device, includes the following steps:

[0090] S1. Install and fix the brake clearance adjusting arm using the main worm gear fixing device, and adjust the position of the fixing component to correspond to the position of the main worm gear of the brake clearance adjusting arm.

[0091] Specifically, the adjusting plate 301 is adjusted to a suitable height and fixed. After the fixing flange 302 is installed on the left side of the adjusting plate 301, the spline shaft 303 of the adjusting arm is fixed to the internal gear of the main worm gear of the brake clearance adjusting arm 30.

[0092] S2. Adjust the rotation center of the drive device to be basically aligned with the center of the control ring of the brake gap adjusting arm, and fix it with the inner circle of the control ring of the brake gap adjusting arm through the expansion sleeve of the drive device to achieve complete alignment.

[0093] Specifically, the relative positions of the base plate 1 and the second fixed bracket 14 in the left-right and front-back directions are adjusted by the first guide rail 26 and the second guide rail 28 respectively, and the height of the control ring is adjusted by the height adjustment mechanism in the main worm gear fixing device, so that the expansion sleeve 20 in the drive device is coaxially distributed with the control ring, completing the initial alignment; the second fixed bracket 5 is moved left and right by the second guide rail 28 until the right end of the expansion sleeve 20 is inserted into the inner circle of the control ring, and the two are interference-fitted. Then, the lever adjusting arm 21 is adjusted to be parallel to the control ring, and the lever 22 is adjusted along the length direction of the lever adjusting hole 2103 so that the right end of the adjusting lever 22 corresponds to the position of the through hole on the control ring. After the bolt passes through the through hole on the control ring, it is threadedly connected to the control ring fixing hole 2202 and tightened to fix the right end of the adjusting lever 22 to the control ring. The external thread lever 2201 on the left side is tightened to the lever adjusting arm 21 by lever tightening nut 24 and lever adjusting nut 23. Finally, the connection and fixation between the drive device and the control ring are completed, achieving perfect alignment. Through the characteristics of the expansion sleeve 20, the inner wall of the control ring is supported outward in the circumferential direction to ensure that the inner wall of the control ring is uniformly stressed in the circumferential direction, thereby ensuring that the center of the control ring is coaxial with the rotation center of the drive device and eliminating the interference of the gap and friction between the control ring and the brake gap control arm housing in the axial direction of the main worm gear.

[0094] S3. Connect the adjusting arm body fixing device to the brake clearance adjusting arm body, and apply torque to the brake clearance adjusting arm body using the torque applying component to eliminate the gap between the main worm wheel and the main worm, the gap between the adjusting arm housing and the main worm wheel, and the gap between the main worm wheel and the fixing component.

[0095] Specifically, the fixing plate 8 moves left and right along the second elongated hole 102 to adjust the position of the torque loading component and the brake clearance adjusting arm 30 in the left and right direction. The cylinder mounting base 9 moves up and down along the fourth elongated hole 801 to adjust the relative position of the torque loading component and the upper end connection of the brake clearance adjusting arm 30. After adjustment, it is fixed to the upper end of the brake clearance adjusting arm 30 by the U-shaped fork 13 and the adjusting arm pin 1301. The cylinder 11 is activated to apply a torque of 6.8 Nm to the brake clearance adjusting arm 30 in a direction parallel to the axis of the main worm. Through the above adjustment, the clearance between the main worm wheel and the main worm in the axial direction of the main worm, the clearance between the housing of the brake clearance adjusting arm 30 and the main worm wheel in the radial direction of the main worm, and the clearance between the main worm wheel and the adjusting arm spline shaft 303 in the circumferential direction of the main worm wheel can be effectively eliminated.

[0096] S4. Install and fix one end of the hexagonal head of the main worm using the hexagonal head fixing device. Adjust the positional relationship between the hexagonal head clamp 6 and the worm hexagonal head using the hexagonal head clamp 6, the connecting plate 5, and the gap shim 605 to eliminate the gap between the main worm hexagonal head and the hexagonal head clamp.

[0097] Specifically, firstly, the first fixed bracket 4 is moved left and right along the first elongated hole 101 to a suitable position. The first angle encoder 7 is fixedly connected to the second arc hole 504 of the clamp mounting plate 503 by bolts. The worm hexagonal head clamp 6 is placed between the worm hexagonal head and the first angle encoder 7. The position of the bracket mounting plate 501 in the height direction on the third elongated hole 401 is adjusted so that the position of the worm hexagonal head clamp 6 corresponds to the position of the worm hexagonal head in the height direction. The bracket mounting plate 501 can be rotated through the first arc hole 502 to find a suitable angle to match the different rotation angles of the brake clearance adjusting arm 30. The adjusting bolt 603 is adjusted from the front... The adjusting bolt 603 passes sequentially through the through hole on the fixture mounting plate 503 and the first angle encoder 7, and is threadedly connected to the fixing nut 602, extending into the fixture housing 601 for a certain length. One end of the adjusting bolt 603, which extends into the fixture housing 601, contacts the abutment part 608 of the fixture contactor 606. A gap shim 605 is placed between the fixture housing 601 and the front end face of the brake gap adjusting arm 30, i.e., the end face where the worm hexagonal head is located. Rotating the adjusting bolt 603 causes the clamping part 609 of the fixture contactor 606 to rotate inward, thereby clamping the worm hexagonal head through multiple sets of clamping parts 609 and removing the gap shim 605.

[0098] It should be noted that when detecting the rotation angle of the worm gear hexagonal head, the anti-rotation nut 604 is in a loose state, that is, it is not in contact with the end face of the fixture mounting plate 503, and the adjusting bolt 603 can rotate; when detecting the rotation angle of the control ring, the anti-rotation nut 604 needs to be tightened to the end face of the fixture mounting plate 503 to prevent the rotation of the worm gear hexagonal head from causing inaccurate positioning of the initial reverse adjustment torque characteristic value, resulting in error in the result.

[0099] By setting the gap shim 605, a certain gap is ensured between the worm gear hexagonal head clamp 6 and the brake gap adjusting arm 30. During the testing process, the friction generated by the direct contact between the worm gear hexagonal head clamp 6 and the brake gap adjusting arm 30 will not affect the test results.

[0100] S5. Adjust the tightening assembly to loosen the worm hexagonal head clamp from the connecting plate. Drive the control ring to rotate counterclockwise via the servo motor 15, thereby driving the pinion assembly and worm to rotate. When the first angle encoder 7 detects a change in the worm hexagonal head rotation angle, it controls the servo motor 15 to stop rotating and records the torque value measured by the torque sensor 17 at this time as the initial rotational torque M.

[0101] Specifically, the anti-rotation nut 604 is loosened to ensure that the clamp housing 601 can rotate with the hexagonal head of the worm. At this time, the servo motor 15 drives the expansion sleeve 20 and the control ring to rotate counterclockwise. The torque sensor 17 and the second angle encoder 18 record the detection values. When the first angle encoder 7 detects the rotation of the main worm, the servo motor 15 stops working and records the measured torque value at this time as the initial rotational torque M of the main worm.

[0102] S6. Tighten the worm hexagonal head clamp 6 to the connecting plate 5 using the tightening assembly to prevent the main worm from rotating. Drive the control ring to rotate counterclockwise from any position via the servo motor 15. Stop the servo motor 15 when it reaches the initial torque M. Then continue to control the servo motor 15 to rotate clockwise. Record the rotation angle and torque values ​​during the rotation process and form a curve showing the relationship between rotation angle and rotation torque.

[0103] S7. After rotating to N peaks, stop the test and calculate the theoretical preset gap angle based on the rotation angle-rotation torque relationship curve:

[0104] like Figure 14 As shown, in this embodiment, N=3, and:

[0105] OA point: The angle through which the servo motor 15 drives the control arm to rotate in the opposite direction from any position to reach the initial rotational torque M of the worm gear. At this time, the anti-rotation nut 604 is in the tightened state.

[0106] AB: When the servo motor 15 drives the control loop to rotate clockwise, it rotates past the preset gap angle and the angle of one ratchet tooth;

[0107] BC: When the servo motor 15 drives the control ring to continue rotating clockwise, it rotates through the angle of the second ratchet.

[0108] CD: When the servo motor 15 drives the control ring to continue rotating clockwise, it rotates through the angle of the third ratchet.

[0109] DE: When the servo motor 15 drives the control ring to continue rotating clockwise, it rotates through the angle of the fourth ratchet.

[0110] The theoretically preset clearance angle = ∠AB - (∠BC + ∠CD + ∠DE) / 3, where:

[0111] ∠AB is the preset clearance angle plus the angle of one ratchet tooth of the clutch worm gear pinion;

[0112] ∠BC is the angle at which the small gear of the clutch worm rotates past the second ratchet tooth;

[0113] ∠CD is the angle at which the small gear of the clutch worm rotates past the third ratchet tooth;

[0114] ∠DE is the angle at which the clutch worm pinion rotates past the fourth ratchet tooth;

[0115] The theoretical preset clearance angle of the test piece can be calculated using the above formula. The boundary value and characteristic value of the torque during the rotation of the brake clearance adjustment arm control ring are accurately located, forming a torque-angle relationship curve with obvious characteristic values. The true result of the preset clearance angle can be obtained by using the periodic time averaging method.

[0116] The technical solution described in this application can eliminate the influence of various interference factors such as gaps and friction forces in the adjusting arm itself and the external environment without disassembling the adjusting arm, and accurately detect the preset angle of the small worm gear of the brake clearance adjusting arm corresponding to the brake clearance.

[0117] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A device for measuring the preset clearance angle of an automotive brake clearance adjusting arm, characterized in that, include: The main worm gear fixing device includes a fixing component for fixing to the internal teeth of the main worm gear, and the fixing component is adjustable in the height direction; A worm gear hexagonal head fixing device includes a first fixed bracket, a connecting plate, and a worm gear hexagonal head clamp. The first fixed bracket and the brake clearance adjusting arm are axially adjustable in the main worm gear. The connecting plate is adjustablely connected to the first fixed bracket in the height direction. The worm gear hexagonal head clamp is fixedly connected between the worm gear hexagonal head and the connecting plate. The connecting plate is rotatably connected to the first fixed bracket along a longitudinal plane parallel to the main worm gear axis to drive the worm gear hexagonal head clamp to be coaxially connected with the worm gear hexagonal head. Furthermore, a first angle encoder and a tightening assembly are provided between the worm gear hexagonal head clamp and the connecting plate. The first angle encoder is fixedly connected between the worm gear hexagonal head clamp and the connecting plate. The tightening assembly is used to tighten or loosen the connecting plate and the first angle encoder. In the loosened state, the worm gear hexagonal head clamp rotates with the brake clearance adjusting arm and the main worm gear. The adjusting arm body fixing device includes a fixing plate and a torque applying component connected between the fixing plate and the brake gap adjusting arm body. The fixing plate is adjustablely connected to the main worm gear fixing device along an axis parallel to the brake ring. The output end of the torque applying component is connected to the brake gap adjusting arm body and is used to drive the brake gap adjusting arm body to rotate around the main worm gear axis. The driving device includes a second fixed bracket, a servo motor, and a tensioning sleeve. The axial position of the main worm gear of the second fixed bracket and the fixed assembly is adjustable along the brake gap adjustment arm. The servo motor is fixedly connected to the second fixed bracket, and its output shaft is fixedly connected to the control ring through the tensioning sleeve. A detection assembly for detecting the rotation angle and torque of the control ring is also provided between the servo motor and the tensioning sleeve. A circumferential limiting device for limiting the relative rotation of the two along the circumferential direction of the inner circle of the control ring is connected between the tensioning sleeve and the control ring.

2. The vehicle brake clearance adjustment arm preset clearance angle measuring device according to claim 1, characterized in that, The main worm gear fixing device includes a base plate, a side plate, and a fixing assembly. The side plate is fixedly connected to the top of the base plate. The fixing assembly consists of an adjusting base and an adjusting arm spline shaft. A height adjustment mechanism is connected between the adjusting base and the side plate. The length of the adjusting arm spline shaft is distributed along a direction parallel to the axis of the main worm gear. One end of the axial direction is fixedly connected to the adjusting base, and the other end is fixedly connected to the internal gear of the main worm gear.

3. The vehicle brake clearance adjustment arm preset clearance angle measuring device according to claim 2, characterized in that, The height adjustment mechanism includes an adjustment plate, a height adjustment bolt, and a sliding guide mechanism disposed between the adjustment base and the side plate. The adjustment plate is fixedly connected to the top of the side plate. The length of the height adjustment bolt is distributed along the height direction and is threadedly connected to the adjustment plate. The lower end of the height adjustment bolt abuts against the upper end of the adjustment base.

4. The vehicle brake clearance adjustment arm preset clearance angle measuring device according to claim 2 or 3, characterized in that, A first guide rail is provided below the base plate. The length of the first guide rail is distributed along a direction parallel to the axis of the main worm gear, and the base plate slides along the length direction of the first moving guide rail.

5. The vehicle brake clearance adjustment arm preset clearance angle measuring device according to claim 1, characterized in that, The connecting plate includes a bracket mounting plate and a clamp mounting plate vertically fixed to the bracket mounting plate. The bracket mounting plate is adjustablely connected to the first fixed bracket along the height direction. The worm hexagonal head clamp is detachably fixedly connected between the worm hexagonal head and the clamp mounting plate. The bracket mounting plate can be rotatably connected to the first fixed bracket along a longitudinal plane parallel to the axis of the main worm to drive the worm hexagonal head clamp on the clamp mounting plate to be coaxially distributed with the main worm.

6. The vehicle brake clearance adjustment arm preset clearance angle measuring device according to claim 1 or 5, characterized in that, The worm gear hexagonal head clamp includes a clamp housing, a clamping assembly, and adjusting bolts. The inner wall of the clamp housing is circumferentially spaced with multiple sets of mounting seats. The clamping assembly consists of multiple sets of connecting seats corresponding to the mounting seats, a fixed shaft fixedly connected between adjacent connecting seats, and a clamping contact rotatably connected to the fixed shaft. The corresponding mounting seats and connecting seats are detachably and fixedly connected. The clamping contact, at the connection point with the rotating shaft and near the worm gear hexagonal head, has a locking portion that mates with the worm gear hexagonal head. The end away from the hexagonal head of the worm gear is provided with an abutment part that mates with the adjusting bolt. One end of the adjusting bolt is axially connected to the abutment part, and the other end is detachably fixed to the clamp mounting plate. A spring piece is provided between the abutment part of the clamping hand and the inner wall of the clamp housing. One end of the spring piece is fixed to the inner wall of the clamp housing, and the other end abuts against the outer side of the abutment part of the clamping hand. The first angle encoder is coaxially fixed to the adjusting bolt, and the tightening assembly is a stop-rotation nut. The stop-rotation nut is threadedly connected to the adjusting bolt.

7. The vehicle brake clearance adjustment arm preset clearance angle measuring device according to claim 6, characterized in that, The first fixed bracket is provided with a third elongated hole whose length is distributed along the height direction. The bracket mounting plate is distributed along the longitudinal plane parallel to the axis of the main worm gear, and the bracket mounting plate is provided with arc-shaped holes that correspond to the positions of the third elongated holes on the first fixed bracket.

8. The vehicle brake clearance adjustment arm preset clearance angle measuring device according to claim 1, characterized in that, The torque application assembly consists of a cylinder connecting seat, a cylinder, a tension sensor, and a U-shaped fork. A cylinder mounting base is fixedly connected to the side of the fixing plate near the brake gap adjusting arm. The cylinder mounting base is adjustablely fixed to the side of the fixing plate near the brake gap adjusting arm along the height direction. The cylinder body is rotatably connected to the cylinder mounting base through the cylinder connecting seat. The cylinder piston rod axis is distributed along the main worm gear axis parallel to the brake gap adjusting arm, and one end of the piston rod is fixedly connected to the brake gap adjusting arm body through the U-shaped fork. The cylinder connecting seat and the cylinder mounting base are rotatably connected.

9. The vehicle brake clearance adjustment arm preset clearance angle measuring device according to claim 8, characterized in that, The fixing plate is provided with a fourth elongated hole distributed along the height direction, and the cylinder mounting base is provided with mounting holes distributed corresponding to the positions of the fourth elongated hole.

10. The vehicle brake clearance adjustment arm preset clearance angle measuring device according to claim 1, characterized in that, The detection component includes a torque limiter, a torque sensor, and an angle encoder. The second fixed bracket is provided with two sets of mounting plates spaced apart along the axial direction of the control ring. The torque limiter, torque sensor, and angle encoder are sequentially and coaxially fixedly connected and rotatably connected between the two sets of mounting plates. The servo motor is fixedly connected to the second fixed bracket and its output shaft is coaxially and fixedly connected to the torque limiter. The end of the angle encoder near the brake ring is connected to the control ring connection assembly.

11. The vehicle brake clearance adjustment arm preset clearance angle measuring device according to claim 1, characterized in that, The circumferential limiting device includes an adjusting lever and a lever adjusting arm. The lever adjusting arm is fixedly connected to the tensioning sleeve. The lever adjusting arm is provided with lever adjusting holes whose length is distributed along the rotation plane parallel to the control ring. The length direction of the adjusting lever is distributed along the axis parallel to the control ring. One end of the adjusting lever is adjustablely fixedly connected to the lever adjusting arm along the length direction of the lever adjusting hole, and the other end is detachably fixedly connected to the control ring.

12. The vehicle brake clearance adjustment arm preset clearance angle measuring device according to claim 1, characterized in that, A second guide rail is provided below the second fixed bracket. The length of the second guide rail is distributed along the axis of the control ring of the brake gap control arm, and the second fixed bracket slides along the length of the second guide rail.

13. A method for measuring the preset clearance angle of an automotive brake clearance adjusting arm, based on the automotive brake clearance adjusting arm preset clearance angle measuring device according to any one of claims 1-12, characterized in that, Includes the following steps: S1. The main worm gear fixing device is used to install and fix the brake clearance adjusting arm. The fixing component is fixedly connected to the main worm gear of the brake clearance adjusting arm and adjusted to a suitable height. S2. Adjust the rotation center of the drive device to be basically aligned with the center of the control ring of the brake gap adjusting arm, and fix the control ring connecting assembly of the drive device to the inner circle of the control ring of the brake gap adjusting arm to achieve complete alignment, and fix the expansion sleeve to the control ring through the circumferential limiting device. S3. Connect the adjusting arm body fixing device to the brake clearance adjusting arm body, and apply torque to the brake clearance adjusting arm body using the torque applying component to eliminate the free clearance between the main worm gear and the main worm, the clearance between the brake clearance adjusting arm body and the main worm gear, and the clearance between the main worm gear and the fixing component. S4. Install and fix one side of the hexagonal head of the main worm using the hexagonal head fixing device. Adjust the hexagonal head clamp and the hexagonal head of the worm using the hexagonal head clamp, connecting plate and clearance shim to eliminate the gap between the main worm and the hexagonal head clamp. S5. Adjust the tightening assembly to loosen the worm hexagonal head clamp from the connecting plate. Drive the control ring to rotate via the servo motor, which in turn drives the pinion assembly and worm to rotate. When the first angle encoder detects a change in the worm hexagonal head rotation angle, it controls the servo motor to stop rotating and records the torque at this time as the initial torque M. S6. Tighten the hexagonal head clamp of the worm gear to the connecting plate using the tightening assembly so that the main worm gear cannot rotate. Drive the control ring to rotate from any position along the rotation direction in step S5 through the servo motor. When the rotation reaches the initial torque M, stop the servo motor rotation and control the servo motor to rotate in the opposite direction. Record the rotation angle and torque values ​​during the rotation process and form a curve showing the relationship between rotation angle and rotation torque. S7. After rotating to N peaks, stop the test and calculate the theoretical preset clearance angle = ∠AB - (∠BC + ∠CD + ∠DE + … ∠N) / N based on the rotation angle - rotation torque relationship curve, where: ∠AB is the preset clearance angle plus the angle of one ratchet tooth of the clutch worm gear pinion; ∠BC is the angle at which the small gear of the clutch worm rotates past the second ratchet tooth; ∠CD is the angle at which the small gear of the clutch worm rotates past the third ratchet tooth; ∠DE is the angle at which the clutch worm pinion rotates past the fourth ratchet tooth; ∠N is the angle at which the clutch worm pinion rotates through the Nth ratchet tooth.

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