Device and method for measuring preset clearance angle of automobile brake clearance adjusting arm

Abstract

In order to solve the problem of poor detection accuracy of a preset clearance angle of a brake clearance adjusting arm, the invention provides a device and a method for measuring the preset clearance angle of an automobile brake clearance adjusting arm. Comprising a main worm gear fixing device, a worm hexagonal head fixing device used for fixing and detecting a main worm hexagonal head of the brake clearance adjusting arm, an adjusting arm body fixing device, and a driving device used for centering an adjusting arm control ring, driving the control ring to rotate and detecting the rotation angle and torque in the rotation process. The main worm gear fixing device comprises a fixing assembly which is used for fixing a main worm gear of the brake clearance adjusting arm and is adjustable in position in the height direction, and the adjusting arm body fixing device drives an arm body of the brake clearance adjusting arm to rotate around the axis of the main worm gear by arranging a torque applying assembly so as to apply a certain torque. The interference of unnecessary clearance and friction force is eliminated to the greatest extent, and the accuracy of the measurement of the preset clearance angle of the to-be-measured piece is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of vehicles, and in particular to a device and method for measuring a preset clearance angle of a vehicle brake clearance adjustment arm. Background Art

[0002] When a heavy-duty vehicle brakes, the brake clearance adjustment arm is a key component responsible for transmitting torque and adjusting brake clearance. The size of the brake clearance directly affects the braking performance and safety of the vehicle. When the brake clearance is too small, it is easy to cause brake drag and temperature to rise, and in severe cases, it may cause fire or tire blowout; when the brake clearance is too large, the braking force is attenuated, resulting in a long braking distance and inability to stop, which may easily lead to serious safety accidents; the preset clearance angle of the brake clearance adjustment arm is closely related to the brake clearance, which determines the initial inherent clearance between the brake drum and the brake shoe, that is, under any circumstances, the brake clearance should always maintain a certain value to ensure the safety and performance of braking. This certain value is determined by the preset clearance angle of the brake clearance adjustment arm. Therefore, it is very important to verify the accuracy of this angle.

[0003] At present, there are few types and quantities of preset clearance angle detection equipment for automobile brake clearance adjustment arms in the industry. A fixed adjustment arm worm gear is used, and a lever is used to turn the control ring to detect torque changes and calculate the angle value as the preset clearance angle. This process does not exclude the influence of various clearances of the brake clearance adjustment arm on the test results, does not consider the influence of friction, and does not have a clear definition of torque value. In the actual detection process of the detection method, there are problems with the rationality of the installation method and detection method of the brake clearance adjustment arm, and the test logic is not rigorous enough, resulting in poor consistency of the output preset clearance angle results and a large difference from the design value, causing the relevant manufacturers to abandon the equipment and cause economic losses. The measurement of the preset clearance angle should be achieved by detecting the torque and angle of the rotation of the brake clearance adjustment arm control ring through careful detection methods and calculation detection. It is the most direct and convenient way to achieve it without disassembling the brake clearance adjustment arm. Summary of the invention

[0004] In order to solve the technical problems of poor detection accuracy of the preset clearance angle of the brake clearance adjustment arm and lack of rigor and logic in the test method, the present invention provides a device and method for measuring the preset clearance angle of the automobile brake clearance adjustment arm, and the technical solution adopted is as follows: A device for measuring a preset clearance angle of a vehicle brake clearance adjustment arm, characterized by comprising: The main worm gear fixing device comprises a fixing component for fixingly connecting with the inner teeth of the main worm gear, and the fixing component is adjustable in height direction; A worm hexagonal head fixing device comprises a first fixing bracket, a connecting plate, and a worm hexagonal head clamp, wherein the position between the first fixing bracket and the brake clearance adjustment arm in the main worm gear axis direction is adjustable, the connecting plate is adjustably connected to the first fixing bracket in the height direction, the worm hexagonal head clamp is fixedly connected between the worm hexagonal head and the connecting plate, and the connecting plate is rotatably connected to the first fixing bracket along a longitudinal plane parallel to the main worm axis to drive the worm hexagonal head clamp to be coaxially connected to the worm hexagonal head, and a first angle encoder and a tightening assembly are further arranged between the worm hexagonal head clamp and the connecting plate, the first angle encoder is fixedly connected between the worm hexagonal head clamp and the connecting plate, the tightening assembly is used to tighten or loosen the connecting plate and the first angle encoder, and in the loosened state, the worm hexagonal head clamp rotates with the main worm of the brake clearance adjustment arm; The adjusting arm body fixing device comprises a fixing plate, a torque applying assembly connected between the fixing plate and the brake clearance adjusting arm body, the fixing plate is adjustably connected to the main worm gear fixing device along the axis parallel to the brake ring, and the output end of the torque applying assembly is connected to the brake clearance adjusting arm body to drive the brake clearance adjusting arm body to rotate around the main worm gear axis; The driving device includes a second fixed bracket, a servo motor, and a clamping sleeve. The axial position of the main worm gear along the brake clearance adjustment arm between the second fixed bracket and the fixed component is adjustable. The servo motor is fixedly connected to the second fixed bracket and the output shaft is fixedly connected to the control ring through the clamping sleeve. A detection component for detecting the rotation angle and torque of the control ring is also arranged between the servo motor and the clamping sleeve. A circumferential limit device is connected between the clamping sleeve and the control ring for limiting the relative rotation of the two along the circumferential direction of the inner circle of the control ring.

[0005] Furthermore, the brake clearance adjustment arm includes a bottom plate, a side plate, and a fixed assembly. The side plate is fixedly connected to the top of the bottom plate. The fixed assembly consists of an adjustment base and an adjustment arm spline shaft. A height adjustment mechanism is connected between the adjustment base and the side plate. The length of the adjustment arm spline shaft is distributed in a direction parallel to the axis of the main worm gear. One axial end is fixedly connected to the adjustment base, and the other end is fixedly connected to the inner teeth of the main worm gear.

[0006] Furthermore, the height adjustment mechanism includes an adjustment plate, an adjustment bolt, and a sliding guide mechanism arranged 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 adjustment bolt is distributed along the height direction and is threadedly connected to the adjustment plate. The lower end of the adjustment bolt abuts against the upper end of the adjustment base.

[0007] Furthermore, a first guide rail is arranged below the bottom plate, and the length of the first guide rail is distributed in a direction parallel to the axis of the main worm gear, and the bottom plate can slide along the length direction of the first movable guide rail.

[0008] 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 adjustably 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, and 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.

[0009] Furthermore, the worm hexagonal head clamp comprises a clamp housing, a clamping assembly, and an adjusting bolt. The inner wall of the clamp housing is provided with a plurality of groups of mounting seats at intervals along the circumferential direction. The clamping assembly is composed of a plurality of groups of connecting seats distributed corresponding to the plurality of mounting seats, a fixed shaft fixedly connected between two adjacent connecting seats, and a clamp tentacle rotatably connected to the fixed shaft. The correspondingly distributed mounting seats and connecting seats are detachably fixedly connected. A clamping joint matching with the worm hexagonal head is provided at the connection between the clamp tentacle and the rotating shaft and at one end close to the worm hexagonal head. The worm gear has one end which is fixed to the locking nut and the other end which is detachably connected to the fixture mounting plate. The worm gear has one end which is fixedly secured to the fixture housing and has a locking nut which is secured to the fixture housing.

[0010] Furthermore, 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 a longitudinal plane parallel to the axis of the main worm, and the bracket mounting plate is provided with arc holes distributed corresponding to the position of the third elongated hole on the first fixed bracket.

[0011] Furthermore, the torque application assembly consists of a cylinder connecting seat, a cylinder, a tension sensor and a U-shaped fork. The cylinder mounting base is adjustably fixedly connected to a side of a fixed plate close to a brake clearance adjustment arm along a height direction. The cylinder body portion is rotatably connected to the cylinder mounting base through the cylinder connecting seat. The axis of the cylinder piston rod is distributed along a main worm axis parallel to the brake clearance adjustment arm and one end of the piston rod is fixedly connected to the arm body of the brake clearance adjustment arm through a U-shaped fork. A cylinder mounting base is fixedly connected to a side surface of the fixed plate close to the brake clearance adjustment arm, and the cylinder connecting seat is rotatably connected to the cylinder mounting base.

[0012] Furthermore, the fixing plate is provided with fourth elongated holes distributed along the height direction, and the cylinder mounting base is provided with mounting holes distributed corresponding to the positions of the fourth elongated holes.

[0013] Furthermore, the detection component includes a torque limiter, a torque sensor, and an angle encoder. The second fixed bracket is provided with two groups of mounting plates spaced apart along the axial direction of the control ring. The torque limiter, torque sensor, and angle encoder are coaxially fixedly connected in sequence and the three are rotatably connected between the two groups of mounting plates. The servo motor is fixedly connected to the second fixed bracket and the output shaft is coaxially fixedly connected to the torque limiter. The end of the angle encoder close to the brake ring is connected to the control ring connecting assembly.

[0014] Furthermore, the circumferential limit assembly includes an adjustment rod and a rod adjustment arm, the rod adjustment arm is fixedly connected to the expansion sleeve, and a rod adjustment hole is provided on the rod adjustment arm, the length direction of the adjustment rod is distributed along the axial direction parallel to the control ring, and one end of the adjustment rod is adjustably fixedly connected to the rod adjustment arm along the length direction of the rod adjustment hole, and the other end is detachably fixedly connected to the control ring.

[0015] Furthermore, a second guide rail is arranged below the second fixed bracket, the length of the second guide rail is distributed along the axis direction of the control ring of the brake clearance control arm, and the second fixed bracket can slide along the length direction of the second guide rail.

[0016] A method for measuring a preset clearance angle of an automobile brake clearance adjustment arm is based on the above-mentioned device for measuring a preset clearance angle of an automobile brake clearance adjustment arm, and is characterized in that it comprises the following steps: S1. The main worm gear fixing device is used to install and fix the brake clearance adjustment arm, and the main worm gear of the brake clearance adjustment arm is fixedly connected with the fixing assembly and adjusted to a suitable height; S2. Adjust the rotation center of the driving device to be basically aligned with the center of the control ring of the brake clearance adjustment arm, and fix it to the inner circle of the control ring of the brake clearance adjustment arm through the control ring connecting component of the driving device to achieve complete alignment, and fix the expansion sleeve to the control ring through the circumferential limit component; S3, connecting the adjusting arm body fixing device with the brake clearance adjusting arm body, and applying torque to the brake clearance adjusting arm body by using a torque applying assembly 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 assembly; S4. Install and fix one side of the hexagonal head of the main worm by using the worm hexagonal head fixing device, and adjust the worm hexagonal head fixture and the worm hexagonal head by using the worm hexagonal head fixture, the connecting plate and the gap gasket to eliminate the gap between the main worm and the worm hexagonal head fixture; S5. Adjust the tightening assembly so that the worm hexagonal head fixture and the connecting plate are in a loose state, and drive the control ring to rotate through the servo motor, thereby driving the pinion assembly and the worm to rotate. When the first angle encoder detects a change in the value of the worm hexagonal head angle, the servo motor is controlled to stop rotating, and the torque at this time is recorded as the initial torque M; S6. Tighten the worm hexagonal head fixture and the connecting plate by using a tightening assembly to prevent the main worm from rotating. The control ring is driven by a servo motor to rotate from any position along the rotation direction in step S5. When the servo motor rotates to the initial rotation torque M, the servo motor is stopped and controlled to rotate in the opposite direction. The rotation angle and torque values ​​during the rotation process are recorded to form a rotation angle-rotation torque relationship curve. S7. After rotating to N peaks, stop the test and calculate the theoretical preset clearance angle = ∠AB-(∠BC+∠CD+∠DE+…∠N) / N according to 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 pinion; ∠BC is the angle at which the clutch worm pinion rotates past the second ratchet tooth; ∠CD is the angle at which the clutch worm pinion 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.

[0017] The beneficial effects of the present invention are: 1. The relative position relationship between the main worm gear fixing device and the driving device can be adjusted respectively through the first guide rail and the second guide rail, so as to realize the connection between the fixing assembly and the expansion sleeve and the brake clearance adjustment arm, and the fixing assembly is driven up and down in combination with the height adjustment mechanism to ensure the centering installation of the brake clearance adjustment arm, avoiding the influence of friction and clearance caused by different axes on the detection results; 2. The torque applying assembly provided in the arm body fixing device of the brake clearance adjustment arm is used to load the brake clearance adjustment arm housing with torque, which can effectively eliminate the gap between the main worm gear and the main worm, and can also simultaneously eliminate the gap between the brake clearance adjustment arm housing and the main worm gear, and eliminate the gap between the main worm gear and the adjustment arm spline shaft in the circumferential direction of the main worm gear; 3. A worm hexagonal head fixture is used to fix and clamp the worm hexagonal head of the brake clearance adjustment arm. The worm hexagonal head fixture in this scheme can tightly clamp the worm hexagonal head to avoid excess clearance, and the worm hexagonal head fixture and the first angle encoder are fixed to the brake clearance adjustment arm through a connecting plate. The installation angle of the worm hexagonal head fixture can be adjusted through the first arc hole set on the bracket mounting plate, so that the worm hexagonal head fixture is coaxial with the worm of the brake clearance adjustment arm to avoid the influence of friction and internal stress; 4. A gap gasket is set between the worm hexagonal head fixture and the end face of the brake clearance adjustment arm where the worm hexagonal head is located to ensure that there is a certain gap between the two to prevent the worm hexagonal head fixture from being closely attached to the brake clearance adjustment arm housing during installation, thereby avoiding the friction generated during the detection process from affecting the initial rotational torque of the worm; 5. After passing through the first angle encoder, the adjusting bolt is clamped by the clamp tentacles and the hexagonal head of the worm. While fixing the hexagonal head of the worm, the rotation angle of the worm can be measured by the first angle encoder. In addition, a stop nut is provided on the adjusting bolt. Tightening the stop nut can prevent the adjusting bolt from rotating, thereby avoiding the problem of inaccurate angle measurement caused by the rotation of the worm when the rotating control ring reaches the initial rotation torque; 6. Use a locking sleeve to fit tightly against the inner wall of the control ring and support the control ring of the adjusting arm on the center of rotation, which can prevent the gap 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 the rotation process, thereby affecting the calculation of the angle; 7. The adjustment lever can adjust the installation position of the adjustment lever along the length direction of the lever adjustment hole on the lever adjustment arm, and the position of the adjustment lever in the axial direction of the control ring can be adjusted by connecting the bolt with the control ring fixing hole on the adjustment lever to make it fit the control ring, which can be applied to the fixing of the control ring of the brake clearance adjustment arm of different product models; 8. In the arm body fixing device of the brake clearance adjustment arm, the position of the torque applying assembly in the axial direction of the worm gear can be adjusted through the second long hole, and the position of the torque applying assembly in the height direction can be adjusted through the fourth long hole to match different models of brake clearance adjustment arms; 9. In the torque loading assembly, the cylinder is connected to the cylinder mounting base through the 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 adjustment arm body, the direction of the force forms an obtuse or acute angle with the brake clearance adjustment arm body to prevent the generation of internal stress and affect the applied force value, thereby effectively eliminating the free gap between the main worm and the main worm wheel, and avoiding affecting the measurement of the preset gap angle; 10. This solution effectively improves the accuracy of the test results by eliminating friction and gap that may affect the detection accuracy and avoiding interference from irrelevant factors to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of the present invention Figure 2 Schematic diagram of the main worm gear fixing device structure Figure 3 Schematic diagram of the worm hexagonal head fixing device structure Figure 4 Schematic diagram of the worm hexagonal head fixture structure Figure 5 Schematic diagram of the fixture housing structure Figure 6 Schematic diagram of the gripper tentacle structure Figure 7 Schematic diagram of the clamping assembly structure Figure 8 Schematic diagram of the connection structure between the fixture housing and the clamping assembly Fig. 9 Schematic diagram of the gap gasket structure Fig.10 Schematic diagram of the structure of the arm body fixing device for adjusting the arm Fig.11 Schematic diagram of the drive device structure Fig.12 Schematic diagram of the lever adjustment arm structure Fig.13 Schematic diagram of the lever structure for adjustment Fig.14 The theoretical curve of torque and rotation angle of brake clearance adjustment arm control ring Among them, 1-bottom plate, 101-first long strip hole, 102-second long strip hole, 103-recess; 2-side plate, 201-guide groove, 202-adjustment base mounting hole; 3-adjustment base, 301-adjustment plate, 302-fixing flange, 303-adjustment arm spline shaft, 304-adjustment arm support disc, 305-adjustment plate, 306-height adjustment bolt, 307-guide key, 308-fastening bolt; 4-first fixing bracket, 401-third long hole, 402-first bottom plate mounting hole; 5-connecting plate, 501-bracket mounting plate, 502-first arc hole, 503-clamp mounting plate, 504-second arc hole; 6-worm hexagonal head clamp, 601-clamp housing, 602-fixing nut, 603-adjusting bolt, 604-stop nut, 605-gap gasket, 606-clamp tentacle, 607-rotation hole, 608-abutment part, 609-clamping part, 6010-rotation shaft, 6011-connecting block, 6012-fixing seat, 6013-fixing bolt, 6014-spring, 6015-cone head; 7- first angle encoder; 8-fixed plate, 801-fourth long hole, 802-second bottom plate mounting hole; 9-cylinder mounting base, 901-rotating pin, 10-cylinder connecting seat, 11-cylinder, 12-tension pressure sensor, 13-U-shaped fork, 1301-adjusting arm pin; 14-second fixed bracket, 1401-end bearing, 15-servo motor, 16-torque limiter, 17-torque sensor, 18-second angle encoder, 19-transition sleeve, 20-expansion sleeve, 21- lever adjustment arm, 2101- fixing bolt hole, 2102- through hole, 2103- lever adjustment hole; 22-adjustment lever, 2201-external thread lever, 2202-control ring fixing hole; 23- lever adjustment nut, 24- 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 adjustment arm. DETAILED DESCRIPTION

[0019] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0020] In the description of the invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the viewing direction or positional relationships and are only for the convenience of describing the invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention.

[0021] like Figure 1As shown, a preset clearance angle measuring device for an automobile brake clearance adjustment arm comprises a main worm gear fixing device, a worm hexagonal head fixing device, an adjustment arm body fixing device and a driving device. The main worm gear fixing device can adjust the position along the main worm axis direction, and comprises a fixing component for fixing the main worm gear of the brake clearance adjustment arm, and the fixing component is adjustable in height direction. The worm hexagonal head fixing device is used to fix and detect the main worm hexagonal head of the brake clearance adjustment arm. The adjustment arm body fixing device drives the brake clearance adjustment arm body to rotate around the main worm gear axis through a torque applying component to apply a certain torque to the brake clearance adjustment arm body. The driving device is used to drive the control ring to rotate and detect the rotation angle and torque during the rotation process, so as to calculate the preset clearance angle.

[0022] Main worm gear fixing device Figure 1 and Figure 2 As shown, it includes a fixing component, which consists of a bottom plate 1, a side plate 2 and an adjustment base 3. The bottom plate 1 is horizontally distributed, the side plate 2 is fixedly connected to the middle position on the right side above the bottom plate 1, the adjustment base 3 is connected to the left side of the side plate 2, and a height adjustment mechanism is provided between the adjustment base 3 and the side plate 2 for adjusting the height position of the adjustment base 3 on the side plate 2.

[0023] Specifically, the front and rear ends of the bottom plate 1 are respectively provided with a first long hole 101 and a second long hole 102, the lengths of which are horizontally distributed in the left-right direction. A first guide rail 26 is provided below the bottom plate 1, and the length of the first guide rail 26 is distributed along the main worm axial direction parallel to the brake clearance adjustment arm. The bottom 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 for fixing the position of the bottom plate 1 on the first guide rail 26; the side plate 2 is vertically distributed in the height direction; the adjustment base 3 is composed of an adjustment plate 301, a fixing flange 302, and an adjustment arm spline shaft 303, the adjustment plate 301 is distributed in parallel on the left side of the side vertical plate 2, the fixing flange 302 is detachably fixedly connected to the left side of the adjustment plate 301 by bolts, the adjustment arm spline shaft 303 is fixedly connected to the left side of the fixing flange 302, the left end of the adjustment arm spline shaft 303 is fixedly connected to the main worm gear inner teeth on the brake clearance adjustment arm, and the adjustment arm spline shaft 303 is also coaxially fixedly connected with an adjustment arm support disc 304, the adjustment arm support disc 304 is fitted with the opposite side of the brake clearance adjustment arm away from the brake ring, thereby fixing the brake clearance adjustment arm; the height adjustment The mechanism includes a guide key 307 and a guide groove 201. The guide groove 201 is arranged on the left side of the side stand 2 and its length is distributed in the vertical direction. The guide key 307 is fixedly connected to the right side of the adjustment plate 302 and is slidably connected with the guide groove 201 up and down. The adjustment plate 302 cooperates with the guide groove 201 through the guide key 307 so that it can slide up and down along the side stand 2. An adjustment plate 305 is also fixedly connected above the adjustment plate 301. A height adjustment bolt 306 is threadedly connected to the adjustment plate 305. The length of the height adjustment bolt 306 is distributed in the vertical direction, and its lower end abuts against the side stand 2. The upper end position, and four groups of adjustment base mounting holes 202 are arranged on the side vertical plate 2. The adjustment base mounting holes 202 are all long holes whose lengths are distributed along the height direction. The adjustment plate 301 is provided with mounting holes whose positions correspond to the adjustment base mounting holes 202. By rotating the height adjustment bolts 306, the adjustment plate 301 and the adjustment arm spline shaft 303 can be driven to slide along the height direction of the side vertical plate 2. After the height adjustment is completed, the height of the adjustment base 3 is adjusted by fastening the bolts 308 through the adjustment base mounting holes 202 and the mounting holes on the adjustment plate 301.

[0024] Worm hexagonal head fixing device Figure 1 , Figure 3-Figure 9 As shown, it includes a first fixed bracket 4, a connecting plate 5, a worm hexagonal head clamp 6 and a first angle encoder 7. The worm hexagonal head clamp 6 is fixedly connected between the first fixed bracket 4 and the main worm hexagonal head of the brake clearance adjustment arm through the connecting plate 5, and the first angle encoder 7 is fixedly connected between the worm hexagonal head clamp 6 and the connecting plate 5.

[0025] Specifically, the first fixed bracket 4 is provided with a third elongated hole 401 distributed along the height direction, and a first bottom plate mounting hole 402 is provided at the lower end. The first bottom plate mounting hole 402 is an elongated hole whose length is distributed along the left-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 bottom plate 1, and the two are fixed by passing bolts through the first bottom plate mounting hole 402 and the first elongated hole 101.

[0026] The overall structure of the connecting plate 5 is an L-shaped plate, which is composed of a bracket mounting plate 501 and a clamp mounting plate 503 vertically fixedly connected to the bracket mounting plate 501. The bracket mounting plate 501 is distributed along a Z-direction plane parallel to the axis of the main worm gear. Two groups of first circular arc holes 502 are arranged on the bracket mounting plate 501 for cooperating with the third long strip hole 401. Through the setting of the first circular arc holes 502, the connecting plate 5 can be rotated and adjusted along the plane where the bracket mounting plate 501 is located to ensure that the worm hexagonal head clamp and the main worm gear are coaxially distributed. After the adjustment is completed, the bracket mounting plate 501 and the first fixed bracket 4 are fixed by bolts; the clamp mounting plate 503 is distributed along a Z-direction plane parallel to the axis of the main worm gear. Four groups of second circular arc holes 504 are arranged on the clamp mounting plate 503 for installing the first angle encoder 7.

[0027] The worm hexagonal head clamp 6 is composed of a clamp housing 601, a clamping assembly arranged inside the clamp housing 601, an adjusting bolt 603 and a stop nut 604. The inner wall of the clamp housing 601 is fixedly connected with a plurality of fixed seats 6012 evenly distributed along the circumferential direction; the clamping assembly is composed of a clamp tentacle 606, a rotating shaft 6010, and a connecting block 6011. The clamp tentacle 606 is provided with a plurality of groups, and the plurality of groups of clamp tentacle 606 are evenly distributed along the circumferential direction of the inner wall of the clamp housing 601. The length of the clamp tentacle 606 is distributed in a direction parallel to the main worm axis and close to the worm hexagonal head. One end of the head is a clamping portion 609, which can be clamped with the outer wall of the worm hexagonal head, and the end away from the worm hexagonal head is an abutment portion 608. A rotating hole 607 is provided in the middle of the length direction of the clamp tentacle 606, and a rotating shaft 6010 is rotatably connected in the rotating hole 607. Two adjacent groups of rotating shafts 6010 are fixedly connected and fixedly connected with a group of connecting blocks 6011. The number and position of the connecting blocks 6011 correspond to the multiple groups of fixed seats 6012. The connecting blocks 6011 and the fixed seats 6012 are provided with mounting holes distributed in corresponding positions, and the two are fixed by fixing bolts 6013. The clamping assembly is fixedly connected to the inner wall of the clamp housing 601; a fixing nut 602 is coaxially fixedly connected to the end of the clamp housing 601 away from the worm hexagonal head, and the adjusting bolt 603 is threadedly connected to the fixing nut 602 and can be axially moved inside the clamp housing 601 along the clamp housing 601, so that the axial position of the adjusting bolt 603 inside the clamp housing 601 can be adjusted, and the end of the adjusting bolt 603 close to the worm hexagonal head is a cone head 6015, which is used to cooperate with the abutment portion 608 on the clamp tentacle 606, so that the clamp tentacle 606 and the clamp can be fixedly connected to the inner wall of the clamp housing 601; a fixing nut 602 is coaxially fixedly connected to the end of the clamp housing 601 away from the worm hexagonal head, and the adjusting bolt 603 is threadedly connected to the fixing nut 602 and can be axially moved inside the clamp housing 601 along the clamp housing 601, so that the axial position of the adjusting bolt 603 inside the clamp housing 601 can be adjusted. A spring piece 6014 is also provided between the inner walls of the shell 601, one end of the spring piece 6014 is fixedly connected to the inner wall of the clamp shell 601, and the other end abuts against the outer side surface of the abutment portion 608. By adjusting the bolt 603 to move in the axial direction of the clamp shell 601, the cone head 6015 can be driven to cooperate with the abutment portion 608 to drive the clamp tentacle 606 to rotate along the rotating shaft 6011, thereby driving the clamping portion 609 of the clamp tentacle 606 to open or shrink, thereby realizing the loosening or clamping action of the worm hexagonal head, and the adjusting bolt 603 is coaxially fixedly connected to the first angle encoder 7.

[0028] During installation, the end of the adjusting bolt 603 away from the worm hexagonal head passes through the through hole on the first angle encoder 7 and then through the fixture mounting plate 503. The first angle encoder 7 is fixed to the adjusting bolt 603 and tightened on the fixture mounting plate 503 by the stop nut 604. One end of the first angle encoder 7 is fixed to the second arc hole 504 of the fixture mounting plate 503 by a bolt. Through the second arc hole 504, the first angle encoder 7 can be rotated to a certain angle, which is convenient for the installation of the first angle encoder 7; the worm hexagonal head fixture 6 moves up and down along the third long 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, so as to adapt to the different rotation angles of the brake clearance adjustment arm 30.

[0029] In addition, the worm hexagonal head fixing device also includes a gap gasket 605, and the structure of the gap gasket 605 is as follows: Fig. 9 As shown, an opening for cooperating with the worm hexagonal head is provided, and a gap gasket 605 is provided between the worm hexagonal head fixture 6 and the end face of the brake clearance adjustment arm body where the worm hexagonal head is located. By providing the gap gasket 605, a certain gap can be retained between the worm hexagonal head fixture 6 and the brake clearance adjustment arm 30, thereby avoiding the friction generated by the contact between the worm hexagonal head fixture 6 and the brake clearance adjustment arm 30 during the detection process and affecting the detection result.

[0030] Adjust the arm body fixing device, such as Figure 1 , Figure 2 , Fig.10 As shown, it includes a fixing plate 8, a cylinder mounting base 9, a cylinder connecting seat 10, a cylinder 11, a tension and pressure sensor 12 and a U-shaped fork 13. The fixing plate 8 is an L-shaped structure, and a fourth long hole 801 distributed along the height direction is provided on the upper part, and a second bottom plate mounting hole 802 distributed corresponding to the position of the second long hole 102 is provided at the lower end. The second bottom plate mounting hole 802 is a long hole distributed along the left and right direction. The fixing plate 8 can move left and right along the length direction of the second long hole 102 to adjust the position, and the second bottom plate mounting hole 802 and the second long hole 102 are fixed by bolts passing through the second bottom plate mounting hole 802 and the second long hole 102; the cylinder mounting base 9 is provided with a fourth long hole 801 distributed along the height direction, and a second long hole 102 is provided at the lower end. There are mounting holes distributed corresponding to the positions of the fourth long hole 801, and the cylinder mounting base 9 can adjust its mounting position along the length direction of the fourth long hole 801, and the two are fixed by bolts; the cylinder connecting seat 10 is rotatably connected to the cylinder mounting base 9 through the rotating shaft pin 901, the cylinder body part of the cylinder 11 is fixedly connected to the cylinder connecting seat 10, and the piston rod axis is distributed along the front and rear direction of the viewing direction of the figure, that is, distributed along the direction parallel to the main worm axis, the tension and pressure sensor 12 is fixedly connected between the piston rod of the cylinder 11 and the U-shaped fork 13, and the U-shaped fork 13 is fixedly connected to the brake clearance adjustment arm body through the adjusting arm pin 1301.

[0031] By adjusting the cylinder 11 in the arm body fixing device, a certain torque can be applied to the brake clearance adjusting arm body, so as to simultaneously eliminate the free clearance between the worm gear and the worm on the brake clearance adjusting arm and the clearance between the brake clearance adjusting arm housing and the main worm gear. In addition, the cooperation between the adjusting arm body fixing device and the main worm gear fixing device can eliminate the clearance between the main worm gear and the fixed component, thereby preventing the above-mentioned clearance from affecting the measurement result, thereby improving the measurement accuracy.

[0032] Drive device such as Figure 1 , Figure 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 locking sleeve 20 and a circumferential limit assembly, wherein the circumferential limit assembly includes a lever adjustment arm 21 and an adjustment lever 22 .

[0033] Specifically, the second fixing bracket 14 is a U-shaped plate structure, and the two side plates of the U-shaped structure are spaced apart along the axis direction of the control ring of the brake clearance adjustment arm. Figure 1 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 bearing 1401. The torque limiter 16, the torque sensor 17, and the second angle encoder 18 are coaxially fixedly connected in sequence and are located between the left and right side plates of the second fixed bracket 14. The left 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 15 through the end bearing 1401. The main shaft of the second angle encoder 18 passes through the right side plate of the second fixed bracket 15 to the right and is coaxially fixedly connected with a transition sleeve 19 and a clamping sleeve 20 in sequence. One end of the clamping sleeve 20 is tightly matched with the inner circle of the control ring of the brake clearance adjustment arm. The lever adjustment arm 21 is fixedly connected to the left side of the clamping sleeve 20. Fig.12 As shown, the upper portion of the lever adjustment arm 21 is provided with a through hole 2102 for coaxially fixing 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 portion is provided with a lever adjustment hole 2103, the length of the lever adjustment hole 2103 is distributed along a plane parallel to the control ring, and the lever 22 is adjusted as shown in FIG. Fig.13As shown, its length is distributed along the direction parallel to the axis of the control ring, and includes 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, so as to adjust the position of the adjustment lever 22 in the length direction of the lever adjustment arm 21. In addition, a lever adjustment nut 23 and a lever tightening nut 24 are threadedly connected to the externally threaded lever 2201. The lever adjustment nut 23 and the lever tightening nut 24 are respectively located on the left and right sides of the lever adjustment arm 21. The nut 23 and the lever tightening nut 24 can tighten and fix the adjustment lever 22 and the lever adjustment arm 21 whose positions have been adjusted; the control ring fixing hole 2202 is located at the end of the adjustment lever 22 close to the control ring, and the length is distributed in a direction parallel to the axis of the control ring. The control ring fixing hole 2202 and the through hole on the control ring of the brake clearance adjustment arm 30 are fixedly connected through 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 threadedly connected to the control ring fixing hole 2202 and tightened, thereby fixing the right end of the adjustment lever 22 to the control ring.

[0034] 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-right direction, i.e., along the axis direction of the control ring. The second guide rail 28 is fixedly connected to the ground. A slider slidably connected to the second guide rail 28 is fixedly connected to the lower end surface of the second fixed bracket 14. A recess 103 is also provided at the left end of the base plate 1, which can be used to drive the device to slide a certain distance toward one side of the base plate 1 to avoid interference between components. The second guide rail 28 can be used to adjust the drive device to move in the left-right direction, thereby adjusting the relative position relationship between the expansion sleeve 20 and the control ring in the left-right direction.

[0035] The driving device can eliminate the gap between the control ring and the cover plate, and between the two ratchets in the clutch pinion assembly, to avoid accidental friction and sudden change in rotation angle caused by the gap during rotation, which may affect the characteristic points of the torque and the detection of the rotation angle. At the same time, the control ring is fixed by adjusting the lever 22 to avoid relative rotation between the control ring and the expansion sleeve 20, which may affect the measurement results.

[0036] A method for measuring a preset clearance angle of an automobile brake clearance adjustment arm, based on the above-mentioned preset clearance angle measuring device of an automobile brake clearance adjustment arm, comprises the following steps: S1. Use the main worm gear fixing device to install and fix the brake clearance adjustment arm, and adjust the position of the fixing component to correspond to the main worm gear position of the brake clearance adjustment arm; Specifically, the adjustment plate 301 is adjusted to a suitable height and fixed, and after the fixing flange 302 is installed to the left side of the adjustment plate 301 , the adjustment arm spline shaft 303 is fixed to the inner teeth of the main worm gear of the brake clearance adjustment arm 30 .

[0037] S2. Adjust the rotation center of the driving device to be basically aligned with the center of the control ring of the brake clearance adjustment arm, and fix the driving device to the inner circle of the control ring of the brake clearance adjustment arm through the expansion sleeve to achieve complete alignment; Specifically, the relative positions of the bottom plate 1 and the second fixing bracket 14 in the left-right and front-back directions are adjusted respectively by the first guide rail 26 and the second guide rail 28, 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, and the preliminary alignment is completed; the second fixing 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 fit, and then the lever adjustment arm 21 is adjusted to be parallel to the control ring, and the lever 22 is adjusted along the length direction of the lever adjustment hole 2103, so that the right end of the adjustment 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 by the bolt, thereby fixing the right end of the adjustment arm lever 22 to the control ring, and the external threaded lever 2201 on the left is tightened on the lever adjusting arm 21 through the lever tightening nut 24 and the lever adjusting nut 23, finally completing the connection and fixation between the drive device and the control ring, achieving complete centering, and through the characteristics of the expansion sleeve 20, the inner wall of the inner circle 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, eliminating the interference of the gap and friction between the control ring and the brake clearance control arm housing in the axial direction of the main worm gear.

[0038] S3, connecting the adjusting arm body fixing device with the brake clearance adjusting arm body, and applying torque to the brake clearance adjusting arm body by using the torque applying assembly to eliminate the gap between the main worm gear and the main worm, the gap between the adjusting arm housing and the main worm gear, and the gap between the main worm gear and the fixing assembly; Specifically, the fixing plate 8 moves left and right along the second long hole 102 to adjust the position of the torque loading assembly and the brake clearance adjustment arm 30 in the left and right directions, and the cylinder mounting base 9 moves up and down along the fourth long hole 801 to adjust the relative position of the torque loading assembly and the upper end connection part of the brake clearance adjustment arm 30. After adjustment, it is fixed to the upper end of the brake clearance adjustment arm 30 through the U-shaped fork 13 and the adjustment arm pin shaft 1301, and the cylinder 11 is actuated to apply a torque of 6.8 Nm to the brake clearance adjustment arm 30 in a direction parallel to the axis of the main worm. Through the above adjustment, the gap between the main worm wheel and the main worm of the brake clearance adjustment arm 30 in the axial direction of the main worm, the gap between the brake clearance adjustment arm 30 housing and the main worm wheel in the radial direction of the main worm wheel, and the gap between the main worm wheel and the adjustment arm spline shaft 303 in the circumferential direction of the main worm wheel can be effectively eliminated.

[0039] S4, installing and fixing one end of the hexagonal head of the main worm by means of the worm hexagonal head fixing device, and adjusting the positional relationship between the worm hexagonal head fixture 6 and the worm hexagonal head by means of the worm hexagonal head fixture 6, the connecting plate 5 and the gap gasket 605, so as to eliminate the gap between the main worm hexagonal head and the worm hexagonal head fixture; Specifically, first, the first fixed bracket 4 is moved left and right along the first long hole 101 to a suitable position, the first angle encoder 7 is fixedly connected to the second arc hole 504 of the fixture mounting plate 503 by bolts, the worm hexagonal head fixture 6 is placed between the worm hexagonal head and the first angle encoder 7, and the height direction of the bracket mounting plate 501 on the third long hole 401 is adjusted so that the worm hexagonal head fixture 6 corresponds to the height direction of the worm hexagonal head. 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 adjustment arm 30; the bolt 603 is adjusted from the front It passes through the through hole on the clamp mounting plate 503 and the first angle encoder 7 backward in sequence, and then is threadedly connected to the fixing nut 602 and extends into the clamp housing 601 for a certain length. One end of the adjusting bolt 603 extending into the clamp housing 601 contacts the abutment portion 608 of the clamp tentacle 606, and a gap gasket 605 is placed between the clamp housing 601 and the front end face of the brake clearance adjustment arm 30, i.e., the end face where the worm hexagonal head is located. Rotating the adjusting bolt 603 drives the clamp tentacle 606 to rotate inwardly, thereby clamping the worm hexagonal head through multiple sets of clamping portions 609 and removing the gap gasket 605.

[0040] It should be noted that when detecting the rotation angle of the worm hexagonal head, the stop 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, it is necessary to tighten the stop nut 604 to the end face of the fixture mounting plate 503 to prevent the rotation of the worm hexagonal head from causing inaccurate positioning of the initial reverse adjustment torque characteristic value, resulting in result errors.

[0041] By setting the gap gasket 605, a certain gap is ensured to be retained between the worm hexagonal head fixture 6 and the brake clearance adjustment arm 30, and the friction generated by the direct contact between the worm hexagonal head fixture 6 and the brake clearance adjustment arm 30 will not affect the detection result during the detection process.

[0042] S5. Adjust the tightening assembly so that the worm hexagonal head fixture and the connecting plate are in a loose state, and drive the control ring to rotate counterclockwise through the servo motor 15, thereby driving the pinion assembly and the worm to rotate. When the first angle encoder 7 detects a change in the value of the worm hexagonal head angle, the servo motor 15 is controlled to stop rotating, and the torque value measured by the torque sensor 17 at this time is recorded as the initial torque M; Specifically, the stop 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, and the torque sensor 17 and the second angle encoder 18 record the detection value. When the first angle encoder 7 detects that the main worm is rotating, the servo motor 15 stops working and records the torque value measured at this time as the initial rotation torque M of the main worm. S6. Use the tightening assembly to tighten the worm hexagonal head fixture 6 and the connecting plate 5 to prevent the main worm from rotating. The servo motor 15 drives the control ring to rotate counterclockwise from any position. When the servo motor 15 rotates to the initial torque M, the servo motor 15 is stopped. Then the servo motor 15 is continued to rotate clockwise. The rotation angle and torque values ​​during the rotation process are recorded to form a rotation angle-rotation torque relationship curve. S7. When the rotation reaches N peaks, stop the test and calculate the theoretical preset clearance angle according to the rotation angle-rotation torque relationship curve: like Fig.14 As shown, in this embodiment, N=3, and: Point OA: the angle at which the servo motor 15 drives the control arm to rotate in the opposite direction from any position to reach the initial rotation torque M of the worm, at which time the stop nut 604 is in a tightened state; AB: When the servo motor 15 drives the control ring to rotate clockwise, it rotates through a preset clearance angle and an angle of a ratchet; BC: When the servo motor 15 drives the control ring to continue to rotate clockwise, it rotates past the angle of the second ratchet; CD: When the servo motor 15 drives the control ring to continue to rotate clockwise, it rotates past the angle of the third ratchet; DE: When the servo motor 15 drives the control ring to continue to rotate clockwise, it rotates past the angle of the fourth ratchet; Theoretical preset clearance angle = ∠AB-(∠BC+∠CD+∠DE) / 3, where: ∠AB is the preset clearance angle plus the angle of one ratchet tooth of the clutch worm pinion; ∠BC is the angle at which the clutch worm pinion rotates past the second ratchet tooth; ∠CD is the angle at which the clutch worm pinion rotates past the third ratchet tooth; ∠DE is the angle at which the clutch worm pinion rotates past the fourth ratchet tooth; The theoretical preset clearance angle of the test piece can be calculated through the above formula, and the boundary value and characteristic value of the torque during the rotation of the brake clearance adjustment arm control ring can be accurately located to form a torque and angle relationship curve with obvious characteristic values. The actual result of the preset clearance angle can be measured through the periodic time averaging method.

[0043] The technical solution described in the present application can eliminate the influence of interference factors such as various clearances and frictions within the adjusting arm and the outside world 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.

[0044] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

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

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

3. The preset clearance angle measuring device for the automobile brake clearance adjustment arm according to claim 2, characterized in that: The height adjustment mechanism includes an adjustment plate, an adjustment bolt, and a sliding guide mechanism arranged 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 adjustment bolt is distributed along the height direction and is threadedly connected to the adjustment plate. The lower end of the adjustment bolt abuts against the upper end of the adjustment base.

4. The preset clearance angle measuring device for the automobile brake clearance adjustment arm according to claim 2 or 3, characterized in that: A first guide rail is arranged below the bottom plate, and the length of the first guide rail is distributed in a direction parallel to the axis of the main worm gear, and the bottom plate can slide along the length direction of the first movable guide rail.

5. The preset clearance angle measuring device for the automobile brake clearance adjustment arm according to claim 1, characterized in that: 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 adjustably 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, and 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 preset clearance angle measuring device for the automobile brake clearance adjustment arm according to claim 1 or 5, characterized in that: The worm hexagonal head clamp comprises a clamp housing, a clamping assembly, and an adjusting bolt. The inner wall of the clamp housing is provided with a plurality of mounting seats at intervals along the circumferential direction. The clamping assembly is composed of a plurality of connecting seats distributed corresponding to the plurality of mounting seats, a fixed shaft fixedly connected between two adjacent connecting seats, and a clamp tentacle rotatably connected to the fixed shaft. The correspondingly distributed mounting seats and connecting seats are detachably fixedly connected. A clamping portion cooperating with the worm hexagonal head is provided at the connection between the clamp tentacle and the rotating shaft and at one end close to the worm hexagonal head. An abutment portion cooperating with the adjusting bolt is provided at the end away from the hexagonal head of the worm gear, one axial end of the adjusting bolt is abutted and connected with the abutment portion, and the other end is detachably fixedly connected to the clamp mounting plate, and a spring sheet is provided between the abutment portion of the clamp tentacle and the inner wall of the clamp shell, one end of the spring sheet is fixed to the inner wall of the clamp shell, and the other end abuts against the outer side surface of the abutment portion of the clamp tentacle, the first angle encoder is coaxially fixedly connected to the adjusting bolt, and the tightening assembly is a stop nut, and the stop nut is threadedly connected to the adjusting bolt.

7. The preset clearance angle measuring device for the automobile brake clearance adjustment arm according to claim 6, characterized in that: The first fixed bracket is provided with a third long strip hole whose length is distributed along the height direction, the bracket mounting plate is distributed along a longitudinal plane parallel to the axis of the main worm, and the bracket mounting plate is provided with an arc hole distributed corresponding to the position of the third long strip hole on the first fixed bracket.

8. The preset clearance angle measuring device for the automobile brake clearance adjustment arm 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. The cylinder mounting base is adjustably fixedly connected to a side of a fixed plate close to a brake clearance adjustment arm along a height direction. The cylinder body portion is rotatably connected to the cylinder mounting base via the cylinder connecting seat. The axis of the cylinder piston rod is distributed along a main worm axis parallel to the brake clearance adjustment arm, and one end of the piston rod is fixedly connected to the arm body of the brake clearance adjustment arm via a U-shaped fork. A cylinder mounting base is fixedly connected to a side surface of the fixed plate close to the brake clearance adjustment arm, and the cylinder connecting seat is rotatably connected to the cylinder mounting base.

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

10. The preset clearance angle measuring device for the automobile brake clearance adjustment arm 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 groups of mounting plates spaced apart along the axial direction of the control ring. The torque limiter, torque sensor, and angle encoder are coaxially fixedly connected in sequence and the three are rotatably connected between the two groups of mounting plates. The servo motor is fixedly connected to the second fixed bracket and the output shaft is coaxially fixedly connected to the torque limiter. The end of the angle encoder close to the brake ring is connected to the control ring connecting assembly.

11. The preset clearance angle measuring device for the automobile brake clearance adjustment arm according to claim 1, characterized in that: The circumferential limit assembly includes an adjustment lever and a lever adjustment arm. The lever adjustment arm is fixedly connected to the expansion sleeve. The lever adjustment arm is provided with a lever adjustment hole whose length is distributed along a rotation plane parallel to the control ring. The length direction of the adjustment lever is distributed along an axial direction parallel to the control ring, and one end of the adjustment lever is adjustably fixedly connected to the lever adjustment arm along the length direction of the lever adjustment hole, and the other end is detachably fixedly connected to the control ring.

12. The preset clearance angle measuring device for the automobile brake clearance adjustment arm according to claim 1, characterized in that: A second guide rail is arranged below the second fixed bracket. The length of the second guide rail is distributed along the axis direction of the control ring of the brake clearance control arm. The second fixed bracket can slide along the length direction of the second guide rail.

13. A method for measuring a preset clearance angle of an automobile brake clearance adjustment arm, based on a device for measuring a preset clearance angle of an automobile brake clearance adjustment arm according to any one of claims 1 to 12, characterized in that: The following steps are involved: S1. The main worm gear fixing device is used to install and fix the brake clearance adjustment arm, and the main worm gear of the brake clearance adjustment arm is fixedly connected with the fixing assembly and adjusted to a suitable height; S2. Adjust the rotation center of the driving device to be basically aligned with the center of the control ring of the brake clearance adjustment arm, and fix it to the inner circle of the control ring of the brake clearance adjustment arm through the control ring connecting component of the driving device to achieve complete alignment, and fix the expansion sleeve to the control ring through the circumferential limit component; S3, connecting the adjusting arm body fixing device with the brake clearance adjusting arm body, and applying torque to the brake clearance adjusting arm body by using a torque applying assembly 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 assembly; S4. Install and fix one side of the hexagonal head of the main worm by using the worm hexagonal head fixing device, and adjust the worm hexagonal head fixture and the worm hexagonal head by using the worm hexagonal head fixture, the connecting plate and the gap gasket to eliminate the gap between the main worm and the worm hexagonal head fixture; S5. Adjust the tightening assembly so that the worm hexagonal head fixture and the connecting plate are in a loose state, and drive the control ring to rotate through the servo motor, thereby driving the pinion assembly and the worm to rotate. When the first angle encoder detects a change in the value of the worm hexagonal head angle, the servo motor is controlled to stop rotating, and the torque at this time is recorded as the initial torque M; S6. Tighten the worm hexagonal head fixture and the connecting plate by using a tightening assembly to prevent the main worm from rotating. The control ring is driven by a servo motor to rotate from any position along the rotation direction in step S5. When the servo motor rotates to the initial rotation torque M, the servo motor is stopped and controlled to rotate in the opposite direction. The rotation angle and torque values ​​during the rotation process are recorded to form a rotation angle-rotation torque relationship curve. S7. After rotating to N peaks, stop the test and calculate the theoretical preset clearance angle = ∠AB-(∠BC+∠CD+∠DE+…∠N) / N according to 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 pinion; ∠BC is the angle at which the clutch worm pinion rotates past the second ratchet tooth; ∠CD is the angle at which the clutch worm pinion 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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