An automatic clearance adjusting arm for an automobile brake and its rotation angle control device.

Abstract

This invention relates to an automatic brake clearance adjusting arm and its rotation angle control device for an automobile brake. The rotation angle control device is installed in the third through hole of the housing. The rotating angle control device uses a right-handed external support spring as a one-way clutch. A slot is provided inside the transmission gear, and the clutch sleeve has a plug that can be inserted into the slot. The arc of the slot is equal to the arc of the plug plus the set clearance α°. The clutch can be infinitely divided in the circumferential direction, allowing for stepless adjustment during operation. Unlike existing technologies where the adjusting arm rotation angle exceeds the set value α° but is insufficient to drive the one-way ratchet to engage the next tooth, requiring slow compensation through other mechanisms, this invention allows for rapid adjustment to the set value α°, avoiding lag in the automatic adjustment function of the adjusting arm and minimizing brake clearance fluctuations. Furthermore, the external support spring can transmit greater torque than the clamping spring, eliminating the problem of one-way clutch slippage and ensuring the automatic adjustment function of the adjusting arm remains functional, thus guaranteeing driving safety.

Description

[Technical Field]

[0001] This invention relates to the field of automotive brake technology, and in particular to an automatic clearance adjusting arm for automotive brakes and its rotation angle control device. [Background Technology]

[0002] The automatic brake clearance adjusting arm of a car brake achieves automatic adjustment by controlling the rotation angle of the adjusting arm. The automatic adjustment function is triggered when the rotation angle exceeds a set value. In existing technology, the rotation angle control device uses meshing one-way ratchet teeth. Due to strength considerations, the one-way ratchet can only have N teeth (usually N is 10-20 teeth) in the circumferential direction as the adjustment transmission mechanism. When the adjustment arm rotation angle exceeds the set value, the ratchet engages across one tooth, rotating during the brake return stroke to drive the adjustment mechanism to compensate for the clearance. When the adjustment arm rotation angle exceeds the set value but is insufficient to drive the one-way ratchet teeth to engage to the next tooth, compensation must be made slowly through other mechanisms. The automatic adjustment action of the adjusting arm is delayed. For example, after a car is newly equipped with an automatic adjusting arm and the initial clearance is adjusted, it requires 30-60 presses of the brake pedal to reach the set clearance. Furthermore, after the automatic adjustment arm completes, the brake clearance fluctuates significantly. In addition, the one-way clutch using a clamping spring structure has a slippage failure problem, affecting driving safety. [Summary of the Invention]

[0003] To address the aforementioned issues, this invention provides an automatic brake clearance adjusting arm and its rotation angle control device for automotive brakes. This arm can quickly adjust the clearance to a set value, and the brake clearance fluctuation is minimal after the adjusting arm has automatically adjusted. The external support spring used in this device can transmit greater torque than the clamping spring, and it eliminates the slippage failure problem of the one-way clutch, ensuring that the automatic adjustment function of the adjusting arm will not fail and guaranteeing driving safety.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] An automatic clearance adjusting arm for an automotive brake includes a housing. The housing has a first through hole and a second through hole that are axially connected. A worm gear is installed in the first through hole, and a first worm matching the worm gear is installed in the second through hole. A helical spring is provided at one end of the first worm, and a clutch gear is sleeved at the other end. A control disc assembly, including a gear ring, is provided at one end of the first through hole. The housing also has a third through hole that communicates with the first and second through holes, and the axial directions of the third through hole are parallel to those of the first through hole. A rotation angle control device is installed in the third through hole. The rotation angle control device includes a spindle, and a transmission gear, a return torsion spring, a clutch sleeve, and a second worm sequentially sleeved on the spindle. The clutch sleeve has a first axial countersunk hole opening towards the second worm, and the second worm has a second axial countersunk hole communicating with the first axial countersunk hole. The rotation angle control device also includes a spacer sleeved on the spindle and located within the first and second axial countersunk holes, and a spacer sleeved on the spacer and located within the first and second axial countersunk holes. The external support spring; the transmission gear meshes with the gear ring, and the second worm meshes with the clutch gear; the transmission gear has an axially extending slot, and the clutch sleeve has a plug that can be axially inserted into the slot and rotate radially relative to it. The radial width of the slot is greater than the radial width of the plug, so that a rotational gap is formed between the slot and the plug, and the angle of the rotational gap is α°; one end of the return torsion spring is connected to the transmission gear, and the other end is connected to the plug; when the transmission gear rotates α°, the transmission gear drives the clutch sleeve. Synchronous rotation; when the second worm is fixed and the clutch sleeve tends to rotate counterclockwise, the friction between the inner surface of the first axial countersunk hole and the outer surface of the outer support spring decreases, and the clutch sleeve overcomes the friction and rotates counterclockwise relative to the outer support spring and the second worm, slipping; when the second worm is fixed and the clutch sleeve tends to rotate clockwise, the friction between the inner surface of the first axial countersunk hole and the outer surface of the outer support spring increases, and the clutch sleeve and the outer support spring lock each other, and the clutch sleeve, the outer support spring and the second worm are locked and do not rotate relative to each other.

[0006] As a preferred embodiment, it is further defined as follows: the external support spring is a right-handed spring; the outer circular surfaces at both ends of the external support spring are respectively interference-fitted with the inner surface of the first axial countersunk hole and the inner surface of the second axial countersunk hole.

[0007] As a preferred embodiment, it is further defined that the diameter of the spacer is smaller than the inner diameter of the outer support spring.

[0008] As a preferred embodiment, it is further defined as follows: the slot has a first sidewall and a second sidewall. When the transmission gear rotates clockwise by α°, the first sidewall abuts against the sidewall of the insert block, and the transmission gear drives the clutch sleeve to rotate clockwise; when the transmission gear rotates counterclockwise by α°, the second sidewall abuts against the sidewall of the insert block, and the transmission gear drives the clutch sleeve to rotate counterclockwise.

[0009] As a preferred embodiment, it is further defined as follows: there is a reset space between the transmission gear and the insert block to accommodate the return torsion spring, and the return torsion spring is fitted between the transmission gear and the insert block.

[0010] As a preferred embodiment, the rotation angle control device further includes a bushing sleeved on the mandrel, the bushing sleeve being fixedly connected to the mandrel, one end of the bushing sleeve abutting against the second worm gear, and the other end being provided with a gap elimination cavity, a gap elimination spring being fitted inside the gap elimination cavity, the third through hole being a blind hole, one end of the gap elimination spring abutting against the gap elimination cavity, and the other end abutting against the third through hole.

[0011] As a preferred embodiment, it is further defined that the bushing is snap-fitted to the spindle.

[0012] As a preferred embodiment, it is further defined as follows: the bushing is provided with a fifth through hole communicating with the gap elimination cavity, the inner wall of the fifth through hole has an elastic locking block extending into the gap elimination cavity, and the mandrel is provided with a locking groove that matches the elastic locking block, and the elastic locking block is embedded in the locking groove during assembly.

[0013] As a preferred embodiment, the control panel assembly is further defined as follows: the control arm and the cover plate are covered on the outside of the first through hole and the cover plate covers the third through hole. The control arm and the gear ring are respectively riveted to both sides of the cover plate and can rotate relative to it.

[0014] As a preferred embodiment, it is further defined that: an upper cap and a lower cap are respectively provided at both ends of the second through hole.

[0015] As a preferred embodiment, it is further defined as follows: the housing is provided with a fourth through hole located above and connected to the second through hole, and an oil nozzle and a dust cover covering the oil nozzle are provided in the fourth through hole.

[0016] A rotation angle control device includes a spindle, and a transmission gear, a return torsion spring, a clutch sleeve, and a second worm gear sequentially sleeved on the spindle. The clutch sleeve has a first axial countersunk hole opening towards the second worm gear, and the second worm gear has a second axial countersunk hole communicating with the first axial countersunk hole. The rotation angle control device further includes a spacer sleeved on the spindle and located within the first and second axial countersunk holes, and an outer support spring sleeved on the spacer and located within the first and second axial countersunk holes. The transmission gear has an axially extending slot, and the clutch sleeve has a plug that can be axially inserted into the slot and rotated radially relative to it. The radial width of the slot is greater than the radial width of the plug, such that a gap is formed between the slot and the plug. The rotation clearance is α°; one end of the return torsion spring is connected to the transmission gear, and the other end is connected to the insert block; when the transmission gear rotates α°, the transmission gear drives the clutch sleeve to rotate synchronously; when the second worm is fixed and the clutch sleeve tends to rotate counterclockwise, the friction between the inner surface of the first axial countersunk hole and the outer surface of the outer support spring decreases, and the clutch sleeve overcomes the friction and rotates counterclockwise relative to the outer support spring and the second worm, slipping; when the second worm is fixed and the clutch sleeve tends to rotate clockwise, the friction between the inner surface of the first axial countersunk hole and the outer surface of the outer support spring increases, and the clutch sleeve and the outer support spring lock each other, and the clutch sleeve, the outer support spring and the second worm are locked and do not rotate relative to each other.

[0017] As a preferred embodiment, it is further defined as follows: the external support spring is a right-handed spring; the outer circular surfaces at both ends of the external support spring are respectively interference-fitted with the inner surface of the first axial countersunk hole and the inner surface of the second axial countersunk hole.

[0018] As a preferred embodiment, it is further defined that the diameter of the spacer is smaller than the inner diameter of the outer support spring.

[0019] As a preferred embodiment, it is further defined as follows: the slot has a first sidewall and a second sidewall. When the transmission gear rotates clockwise by α°, the first sidewall abuts against the sidewall of the insert block, and the transmission gear drives the clutch sleeve to rotate clockwise; when the transmission gear rotates counterclockwise by α°, the second sidewall abuts against the sidewall of the insert block, and the transmission gear drives the clutch sleeve to rotate counterclockwise.

[0020] As a preferred embodiment, it is further defined as follows: there is a reset space between the transmission gear and the insert block to accommodate the return torsion spring, and the return torsion spring is fitted between the transmission gear and the insert block.

[0021] As a preferred embodiment, the rotation angle control device further includes a bushing sleeved on the mandrel, the bushing sleeve being fixedly connected to the mandrel, one end of the bushing sleeve abutting against the second worm gear, and the other end being provided with a gap elimination cavity, a gap elimination spring being fitted inside the gap elimination cavity, the third through hole being a blind hole, one end of the gap elimination spring abutting against the gap elimination cavity, and the other end abutting against the third through hole.

[0022] As a preferred embodiment, it is further defined that the bushing is snap-fitted to the spindle.

[0023] As a preferred embodiment, it is further defined as follows: the bushing is provided with a fifth through hole communicating with the gap elimination cavity, the inner wall of the fifth through hole has an elastic locking block extending into the gap elimination cavity, and the mandrel is provided with a locking groove that matches the elastic locking block, and the elastic locking block is embedded in the locking groove during assembly.

[0024] The beneficial effects of this invention are as follows: The rotation angle control device of this invention uses a right-handed external support spring as a one-way clutch. A slot is provided inside the transmission gear, and the clutch sleeve has a plug that can be inserted into the slot. The arc of the slot is equal to the arc of the plug plus the set gap α°. The clutch can be infinitely divided in the circumferential direction, allowing for stepless adjustment during operation. This avoids the situation in existing technologies where the adjustment arm rotation angle exceeds the set value α° but is insufficient to drive the one-way ratchet to engage to the next tooth, requiring slow compensation through other mechanisms. This design can quickly adjust to the set value α°, avoiding the lag problem of the automatic adjustment function of the adjustment arm. Furthermore, after the automatic adjustment of the adjustment arm is completed, the brake gap fluctuation is small. Additionally, the external support spring can transmit greater torque than the clamping spring, eliminating the problem of one-way clutch slippage failure and ensuring that the automatic adjustment function of the adjustment arm does not fail, thus guaranteeing driving safety. [Attached Image Description]

[0025] Figure 1 This is an exploded view of the structure created by this invention;

[0026] Figure 2 This is an exploded view of the rotation angle control device;

[0027] Figure 3 This is a partial sectional view created by the present invention;

[0028] Figure 4 This is a side view of the rotation angle control device;

[0029] Figure 5 yes Figure 4 Sectional view at point AA;

[0030] Figure 6 yes Figure 4 Sectional view at point BB;

[0031] Figure 7 This is a schematic diagram of the control panel assembly;

[0032] Figure 8 This is a sectional view of the bushing.

Detailed Implementation Methods

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0034] As attached Figure 1 To be continued Figure 8As shown, an automatic clearance adjusting arm for an automotive brake includes a housing 1. The housing 1 has a first through hole 2 and a second through hole 3 that are axially connected. A worm gear 4 is installed in the first through hole 2, and a first worm 5 matching the worm gear 4 is installed in the second through hole 3. A helical spring 6 is provided at one end of the first worm 5, and a clutch gear 7 is sleeved at the other end. A control disc assembly, including a gear ring 9, is provided at one end of the first through hole 2. The housing 1 also has a third through hole 10 that communicates with the first through hole 2 and the second through hole 3, and the axial direction of the third through hole 10 is parallel to that of the first through hole 2. A rotation angle control device 11, including a spindle 12, is installed in the third through hole 10. The transmission gear 13, return torsion spring 14, clutch sleeve 15, and second worm gear 18 are sequentially sleeved on the spindle 12. The clutch sleeve 15 is provided with a first axial countersunk hole 141 with an opening facing the second worm gear 18. The second worm gear 18 is provided with a second axial countersunk hole 161 communicating with the first axial countersunk hole 141. The rotation angle control device 11 also includes a spacer 17 sleeved on the spindle 12 and located in the first axial countersunk hole 141 and the second axial countersunk hole 161, and an outer support spring 16 sleeved on the spacer 17 and located in the first axial countersunk hole 141 and the second axial countersunk hole 161. The transmission gear 13 meshes with the gear ring 9, and the second worm gear 18 meshes with the clutch gear 7 to realize the transmission of force and the compensation of backlash. The transmission gear 13 has an axially extending slot 131. The clutch sleeve 15 has a plug 151 that can be axially inserted into the slot 131 and rotate radially relative to it. The radial width of the slot 131 is greater than the radial width of the plug 151, creating a rotational gap 134 between the slot 131 and the plug 151. The angle of the rotational gap 134 is α°. One end of the return torsion spring 14 is connected to the transmission gear 13, and the other end is connected to the plug 151. The elasticity of the return torsion spring 14 determines the relative position of the transmission gear 13 and the clutch sleeve 15 under no external force, thus maintaining a relative distance between the slot 131 and the plug 151. When the transmission gear 13 rotates α°, it drives the clutch sleeve 15 to rotate synchronously. Furthermore, the slot 131 has a first sidewall 132 and a second sidewall 133. When the transmission gear 13 rotates clockwise by α°, the first sidewall 132 abuts against the sidewall of the insert block 151, and the transmission gear 13 drives the clutch sleeve 15 to rotate clockwise. When the transmission gear 13 rotates counterclockwise by α°, the second sidewall 133 abuts against the sidewall of the insert block 151, and the transmission gear 13 drives the clutch sleeve 15 to rotate counterclockwise.

[0035] In this embodiment, the outer support spring 16 is a right-handed spring; the outer circular surfaces at both ends of the outer support spring 16 are respectively interference-fitted with the inner surface of the first axial countersunk hole 141 and the inner surface of the second axial countersunk hole 161. Furthermore, the outer circular surfaces of the outer support spring 16 form friction pairs with the inner surfaces of the first axial countersunk hole 141 and the second axial countersunk hole 161, forming a torsion spring clutch mechanism. When the second worm 18 is fixed and the clutch sleeve 15 tends to rotate counterclockwise, the friction between the inner surface of the first axial countersunk hole 141 and the outer surface of the outer support spring 16 decreases. Under the action of friction, the winding of the outer support spring 16 tends to deform inward. The clutch sleeve 15 overcomes the friction and rotates counterclockwise relative to the outer support spring 16 and the second worm 18, causing slippage. When the second worm 18 is fixed and the clutch sleeve 15 tends to rotate clockwise, the friction between the inner surface of the first axial countersunk hole 141 and the outer surface of the outer support spring 16 increases with the increase of the clockwise rotation torque of the clutch sleeve 15. Under the action of friction, the winding of the outer support spring 16 tends to expand outward. The clutch sleeve 15 and the outer support spring 16 are locked together. The clutch sleeve 15, the outer support spring 16, and the second worm 18 are locked and do not rotate relative to each other. The outer support spring 16 acts as a one-way clutch throughout the process.

[0036] When the car brakes, the gear ring 9 drives the transmission gear 13 to rotate counterclockwise, and the transmission gear 13 rotates for more than [time period missing]. Figure 6 After the set value α° is reached, the clutch sleeve 15 will rotate counterclockwise. Under the action of friction, the outer support spring 16 tends to deform inward. The friction pair pressure formed by the inner hole surface of the clutch sleeve 15 and the outer circle surface of the outer support spring 16 decreases, and the friction force decreases accordingly. The clutch sleeve 15 overcomes the friction force and rotates relative to the second worm gear 18. The rotation angle is the rotation angle of the clutch sleeve 15 minus the set value α°. When the car brakes and returns to its original position, the gear ring 9 drives the transmission gear 13 to rotate clockwise. The transmission gear 13 rotates for more than 100 degrees. Figure 6After setting the value α°, the clutch sleeve 15 will rotate clockwise. Under the action of friction, the outer support spring 16 tends to deform outward. The clutch sleeve 15, constrained by friction, locks with the outer support spring 16 and the second worm gear 18 to form an integral rigid structure for transmission. At this time, the clutch sleeve 15 drives the second worm gear 18 to rotate clockwise to eliminate the excessive rotation angle exceeding the set value α°. The spacer between the outer support spring 16 and the spindle 12 can keep the clutch 15, the outer support spring 16 and the second worm gear 18 in a certain coaxial relationship, which plays a limiting role for the outer support spring 16, reduces the risk of excessive tangential deformation of the outer support spring 16, and effectively improves the service life of the product. Using a right-hand rotating outer support spring as a one-way clutch, the clutch can be infinitely divided in the circumferential direction and is infinitely adjustable during operation. There is no situation in the prior art where the rotation angle of the adjusting arm is greater than the set value α°, but insufficient to drive the one-way ratchet tooth to engage to the next tooth, and can only be slowly compensated by other mechanisms. This design can quickly adjust to the set value α°, avoiding the lag problem of the automatic adjustment function of the adjusting arm and ensuring driving safety. After the automatic adjustment of the adjusting arm is completed, the brake clearance fluctuation is small. In addition, the outer support spring can transmit greater torque than the clamping spring, and there is no problem of slippage failure of the one-way clutch, ensuring that the automatic adjustment function of the adjusting arm will not fail and ensuring driving safety.

[0037] In this embodiment, the diameter of the spacer 17 is smaller than the inner diameter of the outer support spring 16, that is, the diameter of the spacer 17 is smaller than the minimum diameter when the outer support spring 16 is in a contracting trend. The spacer 17 keeps the clutch 15, the outer support spring 16, and the second worm gear 18 in a certain coaxial relationship and plays a limiting role for the outer support spring 16.

[0038] In this embodiment, there is a reset space between the transmission gear 13 and the insert block 151 to accommodate the return torsion spring 14. The return torsion spring 14 is fitted between the transmission gear 13 and the insert block 151. The reset space limits the return torsion spring 14, preventing excessive deformation that could lead to elastic deformation and effectively improving the product's service life.

[0039] In this embodiment, the rotation angle control device 11 further includes a bushing 19 sleeved on the mandrel 12. The bushing 19 is fixedly connected to the mandrel 12, and the fixed connection method includes, but is not limited to, snap-fit ​​connection, threaded connection, adhesive fixation, etc. One end of the bushing 19 abuts against the second worm gear 16, and the other end is provided with a gap elimination cavity 191. A gap elimination spring 20 is fitted inside the gap elimination cavity 191. The third through hole 10 is a blind hole. One end of the gap elimination spring 20 abuts against the gap elimination cavity 191, and the other end abuts against the third through hole 10.

[0040] In this embodiment, the bushing 19 is snap-fitted to the spindle 12. More specifically, the bushing 19 is provided with a fifth through hole 192 communicating with the gap-eliminating cavity 191. The inner wall of the fifth through hole 192 has an elastic locking block 193 extending into the gap-eliminating cavity 191. The elastic locking block 193 has a guide slope 194 on the side facing the fifth through hole 192, facilitating the insertion of the spindle 12. The spindle 12 is provided with a groove 121 matching the elastic locking block 193. During assembly, the front end of the spindle 12 passes sequentially through the transmission gear 13, the return torsion spring 14, the clutch sleeve 15, the spacer sleeve 17, the outer support spring 16, the second worm gear 18, and the fifth through hole 28, allowing the elastic locking block 193 to embed into the groove 121, simplifying assembly. To make the installation between the bushing 19 and the spindle 12 more secure, multiple elastic locking blocks 193 can be provided. The groove 121 is an annular groove. Alternatively, the number of slots 131 and inserts 151 can be one or more. In this embodiment, the number of slots 131 and inserts 151 is preferably two. When there are two slots 131 and inserts 151, the load-bearing capacity between the transmission gear 13 and the clutch sleeve 15 is larger, and the structure is reliable and stable.

[0041] In this embodiment, the control panel assembly includes a control arm 8 and a cover plate 22. The cover plate 22 covers the outside of the first through hole 2 and also covers the third through hole 10. The cover plate 22 provides one-sided coverage of the third through hole 10, serving a decorative purpose and providing waterproof and dustproof effects. The control arm 8 and the gear ring 9 are respectively riveted to both sides of the cover plate 22 and can rotate relative to it, resulting in a simple structure.

[0042] In this embodiment, an upper cap 23 and a lower cap 24 are respectively provided at both ends of the second through hole 3 to seal the second through hole 3. The housing is provided with a fourth through hole located above and connected to the second through hole 3. An oil nozzle 25 and a dust cover 26 covering the oil nozzle 25 are provided in the fourth through hole. Lubricating oil can be injected into the housing 1 through the oil nozzle 25 to reduce wear, improve performance, and extend service life.

[0043] A rotation angle control device includes a spindle 12, and a transmission gear 13, a return torsion spring 14, a clutch sleeve 15, and a second worm gear 18 sequentially sleeved on the spindle 12. The clutch sleeve 15 has a first axial countersunk hole 141 opening towards the second worm gear 18, and the second worm gear 18 has a second axial countersunk hole 161 communicating with the first axial countersunk hole 141. The rotation angle control device also includes a spacer 17 sleeved on the spindle 12 and located within the first axial countersunk hole 141 and the second axial countersunk hole 161, and a spacer 17 sleeved on the spacer 17 and located within the first axial countersunk hole 141 and the second axial countersunk hole 161. The outer support spring 16 is located within the 161; the transmission gear 13 has an axially extending slot 131, and the clutch sleeve 15 has a plug 151 that can be axially inserted into the slot 131 and rotated radially relative to it. The radial width of the slot 131 is greater than the radial width of the plug 151, so that a rotation gap 134 is formed between the slot 131 and the plug 151, and the angle of the rotation gap 134 is α°; one end of the return torsion spring 14 is connected to the transmission gear 13, and the other end is connected to the plug 151; when the transmission gear 13 rotates α°, the transmission gear 13 drives the clutch sleeve 15 to rotate synchronously. Furthermore, the slot 131 has a first sidewall 132 and a second sidewall 133. When the transmission gear 13 rotates clockwise by α°, the first sidewall 132 abuts against the sidewall of the insert block 151, and the transmission gear 13 drives the clutch sleeve 15 to rotate clockwise. When the transmission gear 13 rotates counterclockwise by α°, the second sidewall 133 abuts against the sidewall of the insert block 151, and the transmission gear 13 drives the clutch sleeve 15 to rotate counterclockwise.

[0044] In this embodiment, the outer support spring 16 is a right-handed spring; the outer circular surfaces at both ends of the outer support spring 16 are respectively interference-fitted with the inner surface of the first axial countersunk hole 141 and the inner surface of the second axial countersunk hole 161. Furthermore, the outer circular surfaces of the outer support spring 16 form friction pairs with the inner surfaces of the first axial countersunk hole 141 and the second axial countersunk hole 161, forming a torsion spring clutch mechanism. When the second worm 18 is fixed and the clutch sleeve 15 tends to rotate counterclockwise, the friction between the inner surface of the first axial countersunk hole 141 and the outer surface of the outer support spring 16 decreases. Under the action of friction, the winding of the outer support spring 16 tends to deform inward. The clutch sleeve 15 overcomes the friction and rotates counterclockwise relative to the outer support spring 16 and the second worm 18, causing slippage. When the second worm 18 is fixed and the clutch sleeve 15 tends to rotate clockwise, the friction between the inner surface of the first axial countersunk hole 141 and the outer surface of the outer support spring 16 increases with the increase of the clockwise rotation torque of the clutch sleeve 15. Under the action of friction, the winding of the outer support spring 16 tends to expand outward. The clutch sleeve 15 and the outer support spring 16 are locked together. The clutch sleeve 15, the outer support spring 16, and the second worm 18 are locked and do not rotate relative to each other. The outer support spring 16 acts as a one-way clutch throughout the process.

[0045] In this embodiment, the diameter of the spacer 17 is smaller than the inner diameter of the outer support spring 16, that is, the diameter of the spacer 17 is smaller than the minimum diameter when the outer support spring 16 is in a contracting trend. The spacer 17 keeps the clutch 15, the outer support spring 16, and the second worm gear 18 in a certain coaxial relationship and plays a limiting role for the outer support spring 16.

[0046] In this embodiment, there is a reset space between the transmission gear 13 and the insert block 151 to accommodate the return torsion spring 14. The return torsion spring 14 is fitted between the transmission gear 13 and the insert block 151. The reset space limits the return torsion spring 14, preventing excessive deformation that could lead to elastic deformation and effectively improving the product's service life.

[0047] As a preferred embodiment, it is further defined as follows: there is a reset space between the transmission gear 13 and the insert block 151 to accommodate the return torsion spring 14, and the return torsion spring 14 is fitted between the transmission gear 13 and the insert block 151.

[0048] In this embodiment, the rotation angle control device further includes a bushing 19 sleeved on the mandrel 12. The bushing 19 is fixedly connected to the mandrel 12, and the fixed connection method includes, but is not limited to, snap-fit ​​connection, threaded connection, adhesive fixation, etc. One end of the bushing 19 abuts against the second worm gear 16, and the other end is provided with a gap elimination cavity 191. A gap elimination spring 20 is fitted inside the gap elimination cavity 191. The third through hole 10 is a blind hole. One end of the gap elimination spring 20 abuts against the gap elimination cavity 191, and the other end abuts against the third through hole 10.

[0049] In this embodiment, the bushing 19 is snap-fitted to the spindle 12. More specifically, the bushing 19 is provided with a fifth through hole 192 communicating with the gap-eliminating cavity 191. The inner wall of the fifth through hole 192 has an elastic locking block 193 extending into the gap-eliminating cavity 191. The elastic locking block 193 has a guide slope 194 on the side facing the fifth through hole 192, facilitating the insertion of the spindle 12. The spindle 12 is provided with a groove 121 matching the elastic locking block 193. During assembly, the front end of the spindle 12 passes sequentially through the transmission gear 13, the return torsion spring 14, the clutch sleeve 15, the spacer sleeve 17, the outer support spring 16, the second worm gear 18, and the fifth through hole 28, allowing the elastic locking block 193 to embed into the groove 121, simplifying assembly. To make the installation between the bushing 19 and the spindle 12 more secure, multiple elastic locking blocks 193 can be provided. The groove 121 is an annular groove. Alternatively, the number of slots 131 and inserts 151 can be one or more. In this embodiment, the number of slots 131 and inserts 151 is preferably two. When there are two slots 131 and inserts 151, the load-bearing capacity between the transmission gear 13 and the clutch sleeve 15 is larger, and the structure is reliable and stable.

Claims

1. An automatic clearance adjustment arm of an automobile brake, comprising a housing (1), an axially connected first through hole (2) and a second through hole (3) are formed on the housing (1), a worm wheel (4) is installed in the first through hole (2), a first worm (5) matched with the worm wheel (4) is installed in the second through hole (3), a helical spring (6) is arranged at one end of the first worm (5), and a clutch gear (7) is sleeved at the other end of the first worm (5); one end of the first through hole (2) is provided with a control disc assembly, the control disc assembly comprises a gear ring (9); a third through hole (10) connected with the first through hole (2) and the second through hole (3) is further arranged on the housing (1), and the third through hole (10) is axially parallel to the first through hole (2); characterized in that The third through hole (10) is provided with a rotation angle control device (11), the rotation angle control device (11) comprises a mandrel (12), a transmission gear (13), a return torsion spring (14), a clutch sleeve (15) and a second worm (18) which are sequentially sleeved on the mandrel (12), the clutch sleeve (15) is provided with a first axial counterbore (141) which is open to the second worm (18), the second worm (18) is provided with a second axial counterbore (161) which is communicated with the first axial counterbore (141), the rotation angle control device (11) further comprises a spacer sleeve (17) which is sleeved on the mandrel (12) and located in the first axial counterbore (141) and the second axial counterbore (161), and an outer supporting spring (16) which is sleeved on the spacer sleeve (17) and located in the first axial counterbore (141) and the second axial counterbore (161); the transmission gear (13) is engaged with the gear ring (9), and the second worm (18) is engaged with the clutch gear (7); the transmission gear (13) is provided with an axially extending insertion slot (131), the clutch sleeve (15) has an insertion block (151) which can be axially inserted into the insertion slot (131) and can rotate radially relative to the insertion slot (131), the radial width of the insertion slot (131) is greater than the radial width of the insertion block (151), so that a rotation gap (134) is formed between the insertion slot (131) and the insertion block (151), and the angle of the rotation gap (134) is α°; one end of the return torsion spring (14) is connected with the transmission gear (13), and the other end is connected with the insertion block (151); when the transmission gear (13) rotates α°, the transmission gear (13) drives the clutch sleeve (15) to rotate synchronously; when the second worm (18) is fixed and the clutch sleeve (15) has a tendency to rotate counterclockwise, the friction force generated between the inner hole surface of the first axial counterbore (141) and the outer circular surface of the outer supporting spring (16) is reduced, the clutch sleeve (15) overcomes the friction force and rotates counterclockwise relative to the outer supporting spring (16) and the second worm (18); when the second worm (18) is fixed and the clutch sleeve (15) has a tendency to rotate clockwise, the friction force generated between the inner hole surface of the first axial counterbore (141) and the outer circular surface of the outer supporting spring (16) is increased, the clutch sleeve (15) and the outer supporting spring (16) are locked, and the clutch sleeve (15), the outer supporting spring (16) and the second worm (18) are in a locked state without relative rotation; the outer circular surfaces at both ends of the outer supporting spring (16) are in interference connection with the inner hole surfaces of the first axial counterbore (141) and the second axial counterbore (161) respectively; the diameter of the spacer sleeve (17) is smaller than the minimum diameter of the outer supporting spring (16) when the outer supporting spring (16) has a tendency to shrink, and the spacer sleeve (17) keeps the clutch sleeve (15), the outer supporting spring (16) and the second worm (18) in a certain coaxial relationship, and limits the outer supporting spring (16).

2. The automatic slack adjuster arm of claim 1, wherein The outer supporting spring (16) is a right-handed spring.

3. The automatic slack adjuster arm of claim 2, wherein The slot (131) has a first side wall (132) and a second side wall (133), when the transmission gear (13) rotates clockwise by α°, the first side wall (132) abuts against the side wall of the plug (151), the transmission gear (13) drives the clutch sleeve (15) to rotate clockwise; when the transmission gear (13) rotates counterclockwise by α°, the second side wall (133) abuts against the side wall of the plug (151), the transmission gear (13) drives the clutch sleeve (15) to rotate counterclockwise.

4. The automatic slack adjuster arm of claim 3, wherein The transmission gear (13) and the plug (151) have a reset space for accommodating the return torsion spring (14), the return torsion spring (14) is sleeved between the transmission gear (13) and the plug (151).

5. The automatic slack adjuster arm of claim 4, wherein The rotation angle control device (11) further comprises a shaft sleeve (19) sleeved on the mandrel (12), the shaft sleeve (19) is fixedly connected with the mandrel (12), one end of the shaft sleeve (19) abuts against the second worm (18), the other end is provided with a gap elimination cavity (191), a gap elimination spring (20) is sleeved in the gap elimination cavity (191), the third through hole (10) is a blind hole, one end of the gap elimination spring (20) abuts against the gap elimination cavity (191), and the other end abuts against the third through hole (10).

6. The automatic slack adjuster arm of claim 5, wherein The shaft sleeve (19) is snap connected with the mandrel (12).

7. An automatic slack adjuster arm for a vehicle brake as defined in claim 6 wherein The shaft sleeve (19) is provided with a fifth through hole (192) penetrating through the gap elimination cavity (191), the inner wall of the fifth through hole (192) has an elastic clamping block (193) extending into the gap elimination cavity (191), the mandrel (12) is provided with a clamping groove (121) matched with the elastic clamping block (193), and the elastic clamping block (193) is embedded in the clamping groove (121) during assembly.

8. An automatic slack adjuster arm for a vehicle brake as set forth in any of claims 1-7, characterized in that The control disc assembly comprises a control arm (8) and a cover plate (22), the cover plate (22) covers the outside of the first through hole (2), the cover plate (22) covers the third through hole (10), and the control arm (8) and the gear ring (9) are respectively riveted on the two sides of the cover plate (22) and can rotate relative to the cover plate (22).

9. An automatic slack adjuster arm for a vehicle brake as set forth in any of claims 1-7, characterized in that The second through hole (3) is provided with an upper cover (23) and a lower cover (24) at both ends respectively.

10. The automatic slack adjuster arm of any of claims 1-7, wherein The shell is provided with a fourth through hole located at the upper end of the second through hole (3) and communicating with the second through hole (3), the fourth through hole is provided with an oil nozzle (25) and a dust cover (26) covering the oil nozzle (25).

11. A rotation angle control device characterized by It comprises a mandrel (12), a transmission gear (13), a return torsion spring (14), a clutch sleeve (15) and a second worm (18) which are sleeved on the mandrel (12) in sequence, the clutch sleeve (15) is provided with a first axial counterbore (141) which is open towards the second worm (18), the second worm (18) is provided with a second axial counterbore (161) which is communicated with the first axial counterbore (141), the rotation angle control device (11) further comprises a spacer sleeve (17) which is sleeved on the mandrel (12) and located in the first axial counterbore (141) and the second axial counterbore (161), and an outer supporting spring (16) which is sleeved on the spacer sleeve (17) and located in the first axial counterbore (141) and the second axial counterbore (161); the transmission gear (13) is provided with an axially extending insertion slot (131) inside, the clutch sleeve (15) has an insertion block (151) which can be axially inserted into the insertion slot (131) and can rotate radially relative to the insertion slot (131), the radial width of the insertion slot (131) is greater than the radial width of the insertion block (151), so that a rotation gap (134) is formed between the insertion slot (131) and the insertion block (151), the angle of the rotation gap (134) is α°; one end of the return torsion spring (14) is connected with the transmission gear (13), and the other end is connected with the insertion block (151); when the transmission gear (13) rotates α°, the transmission gear (13) drives the clutch sleeve (15) to rotate synchronously; when the second worm (18) is fixed and the clutch sleeve (15) has a tendency to rotate counterclockwise, the friction force generated between the inner hole surface of the first axial counterbore (141) and the outer circular surface of the outer supporting spring (16) is reduced, the clutch sleeve (15) slips counterclockwise relative to the outer supporting spring (16) and the second worm (18) by overcoming the friction force; when the second worm (18) is fixed and the clutch sleeve (15) has a tendency to rotate clockwise, the friction force generated between the inner hole surface of the first axial counterbore (141) and the outer circular surface of the outer supporting spring (16) is increased, the clutch sleeve (15) and the outer supporting spring (16) are locked with each other, the clutch sleeve (15), the outer supporting spring (16) and the second worm (18) are in a locked state without relative rotation; the outer circular surfaces at both ends of the outer supporting spring (16) are connected with the inner hole surfaces of the first axial counterbore (141) and the second axial counterbore (161) in interference; the diameter of the spacer sleeve (17) is smaller than the minimum diameter of the outer supporting spring (16) when it is in a tendency of shrinking inwards, the spacer sleeve (17) keeps the clutch sleeve (15), the outer supporting spring (16) and the second worm (18) in a certain coaxial relationship, and limits the outer supporting spring (16).

12. The rotation angle control device according to claim 11, characterized by The outer supporting spring (16) is a right-handed spring.

13. The rotation angle control device according to claim 12, characterized by The slot (131) has a first side wall (132) and a second side wall (133), when the transmission gear (13) rotates clockwise by α°, the first side wall (132) abuts against the side wall of the plug-in block (151), the transmission gear (13) drives the clutch sleeve (15) to rotate clockwise; when the transmission gear (13) rotates counterclockwise by α°, the second side wall (133) abuts against the side wall of the plug-in block (151), the transmission gear (13) drives the clutch sleeve (15) to rotate counterclockwise.

14. The rotation angle control device according to claim 13, characterized by The transmission gear (13) and the plug-in block (151) have a reset space for accommodating the reset torsion spring (14), the reset torsion spring (14) is sleeved between the transmission gear (13) and the plug-in block (151).

15. The rotation angle control device according to claim 14, characterized by It also includes a shaft sleeve (19) sleeved on the mandrel (12), the shaft sleeve (19) is fixedly connected with the mandrel (12), one end of the shaft sleeve (19) abuts against the second worm (18), and the other end is provided with a gap elimination cavity (191), and the gap elimination cavity (191) is sleeved with a gap elimination spring (20).

16. The rotation angle control device according to claim 15, characterized by The shaft sleeve (19) is snap-connected with the mandrel (12).

17. The rotation angle control device according to claim 16, characterized by The shaft sleeve (19) is provided with a fifth through hole (192) penetrating through the gap elimination cavity (191), the inner wall of the fifth through hole (192) has an elastic clamping block (193) extending into the gap elimination cavity (191), and the mandrel (12) is provided with a clamping groove (121) matched with the elastic clamping block (193), and when assembled, the elastic clamping block (193) is embedded into the clamping groove (121).

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