A manual / self-adjustable hydraulic brake clearance adjustment mechanism

Abstract

This utility model discloses a manual and automatic adjustable hydraulic brake clearance adjustment mechanism. It includes manual adjustment, which involves fixing an internal threaded sleeve to the brake base and threading an adjusting bolt to the internal threaded sleeve. Adjusting the axial position of the adjusting bolt within the internal threaded sleeve adjusts the axial position of its front end, thereby adjusting the brake clearance. It also includes automatic adjustment, which involves sliding a transmission sleeve within a perforated sleeve, with the brake shoe's tail rod abutting against the transmission sleeve. The outer circumference of the transmission sleeve has a helical groove, and a pin in a pin hole on the perforated sleeve wall is engaged in the helical groove. The front section of the clutch shaft is fitted into the shaft hole of the transmission sleeve via a one-way bearing. The clutch shaft engages with the adjusting bolt via a bevel gear mechanism through a transmission piston. This utility model effectively solves the problems of braking lag, deviation, and excessive braking distance caused by the untimely manual adjustment of the brake clearance, achieving integrated manual and automatic adjustment.

Description

Technical Field

[0001] This utility model relates to a brake clearance adjustment mechanism for automotive hydraulic brakes, and more specifically, to a brake clearance adjustment mechanism for hydraulic brakes that integrates manual and automatic adjustment. Background Technology

[0002] In automotive hydraulic brakes, a proper clearance, known as the brake clearance, needs to be maintained between the brake pads and the brake drum to ensure optimal braking performance. However, the factory-set brake clearance gradually increases due to brake pad wear during use, causing uneven clearance across the four wheels. This can lead to braking lag, vehicle drift, and excessively long braking distances, posing safety hazards and potentially causing traffic accidents. Therefore, it is necessary to adjust the position of the brake pads regularly to maintain the proper clearance with the brake drum. Currently, manual adjustment devices are installed on various models of hydraulic drum brake trucks and buses for manually adjusting the brake clearance. Manual adjustment relies on periodic manual control from under the vehicle to bring the brake pads closer to the brake drum, reducing the clearance between the pads and the drum. However, for randomly occurring wear, this manual periodic adjustment method inevitably suffers from untimely adjustments. Furthermore, the accuracy of manual periodic adjustments heavily depends on the operator's experience, making it difficult to guarantee the quality of the adjustment. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, this utility model provides a manual and automatic adjustable hydraulic brake clearance adjustment mechanism, integrating manual and automatic adjustment functions to ensure timely clearance adjustment and provide assurance for driving safety.

[0004] To achieve the purpose of this invention, the following technical solution is adopted:

[0005] This utility model discloses a manually and automatically adjustable hydraulic brake clearance adjustment mechanism, including a wheel cylinder and brake shoes; its characteristic is that the adjustment mechanism includes a manual adjustment structure and an automatic adjustment structure; the manual adjustment structure consists of an internally threaded sleeve and an adjusting bolt: the internally threaded sleeve is fixedly connected to the brake base, and the adjusting bolt is threadedly connected to the internally threaded sleeve; by adjusting the axial position of the adjusting bolt in the internally threaded sleeve, the axial position of the front end face of the adjusting bolt is changed, thereby adjusting the brake clearance; the automatic adjustment structure consists of a smooth hole The device comprises a sleeve, a transmission sleeve, a one-way bearing, a clutch shaft, and a transmission piston. The perforated sleeve is fixedly connected to the brake base and is coaxial with the internally threaded sleeve. The transmission sleeve is slidably fitted within the perforated sleeve, with the tail rod end face of the brake shoe abutting against the front end face of the transmission sleeve. The tail of the transmission sleeve has a shaft hole, and the outer circumference of the transmission sleeve has a spiral groove. A pin passes through a pin hole on the inner wall of the perforated sleeve and engages in the spiral groove. The one-way bearing is disposed in the shaft hole of the transmission sleeve, and the outer ring of the one-way bearing is statically fitted with the transmission sleeve. The clutch shaft... The front section is fitted into the inner ring of a one-way bearing, allowing for a one-way rotational fit between the transmission sleeve and the clutch shaft. The tail end face of the clutch shaft and the front end face of the transmission piston form a bevel gear engagement structure. This structure allows the clutch shaft and the transmission piston to transmit power to each other during bevel gear engagement and also allows them to disengage from the bevel gear engagement. The clutch shaft has a central shaft hole, through which a fixing bolt passes and is threaded into an internal threaded hole on the end face of the transmission piston. The central shaft hole of the clutch shaft is a stepped hole at the front end, formed by... The fixing bolt presses the inner hole compression spring into the stepped hole of the clutch shaft; the transmission piston abuts against the front end of the adjusting bolt with its large diameter outer annular surface at the front end, and the small diameter body section of the transmission piston is installed in the inner hole of the adjusting bolt, so that the transmission piston and the adjusting bolt form an axial sliding fit. A hole bottom compression spring is set in the inner hole of the adjusting bolt, and the tail end face of the transmission piston abuts against the hole bottom compression spring to obtain axial elastic force. A through groove is machined in the center of the transmission piston, and the pin passes through the through groove and is engaged with the adjusting bolt, so that the transmission piston and the adjusting bolt are linked circumferentially.

[0006] The characteristic of the manual / automatic integrated adjustable hydraulic brake gap adjustment mechanism of this utility model is that a set movable gap is maintained between the pin and the spiral groove.

[0007] The characteristic of this utility model of a manual / automatic integrated adjustable hydraulic brake clearance adjustment mechanism is that a dial is set on the outer circumference of the adjusting bolt, and the axial position of the adjusting bolt in the internal threaded sleeve is adjusted by rotating the dial.

[0008] The characteristic of this utility model of a manual / automatic integrated adjustable hydraulic brake gap adjustment mechanism is that the internal threaded sleeve and the smooth hole sleeve are integral components.

[0009] The characteristic of the manual / automatic integrated adjustable hydraulic brake gap adjustment mechanism of this utility model is that the clutch structure of the bevel gear engagement is that the end face of the clutch shaft is set as the outer bevel gear surface, and the end face of the transmission piston is set as the inner bevel gear surface, forming an engagement between the outer bevel gear surface and the inner bevel gear surface.

[0010] Compared with existing technologies, the beneficial effects of this utility model are reflected in:

[0011] 1. This utility model effectively solves the problems of braking lag, deviation, and excessive braking distance caused by untimely manual adjustment, thus providing reliable protection for driving safety and reducing the workload of drivers and maintenance personnel.

[0012] 2. This utility model can be used to replace the original manual adjustment mechanism and is widely used in various hydraulically braked vehicles. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] The following components are labeled in the diagram: 1. Wheel cylinder, 2. Pin, 3. Smooth sleeve, 4. Transmission sleeve, 5. Fixing bolt, 6. Brake shoe, 7. Inner hole compression spring, 8. One-way bearing, 9. Clutch shaft, 10. Bottom hole compression spring, 11. Bevel gear, 12. Dial, 13. Adjusting bolt, 14. Internal thread sleeve, 15. Spiral groove, 16. Tension spring, 17. Transmission piston, 18. Pin rod, 19. Through groove. Detailed Implementation

[0015] See Figure 1 In this embodiment, the manually adjustable hydraulic brake clearance adjustment mechanism includes a wheel cylinder 1 and a brake shoe 6, such as... Figure 1 As shown, the brake shoe 6 is applied by the wheel cylinder 1, and the brake shoe 6 is reset by the tension spring 16.

[0016] The brake clearance adjustment mechanism in this embodiment includes a manual adjustment structure and an automatic adjustment structure.

[0017] Figure 1 The manual adjustment structure shown consists of an internal threaded sleeve 14 and an adjusting bolt 13. The internal threaded sleeve 14 is fixedly connected to the brake base, and the adjusting bolt 13 is threadedly connected to the internal threaded sleeve 14. By adjusting the axial position of the adjusting bolt 13 in the internal threaded sleeve 14, the axial position of the front end face of the adjusting bolt 13 is changed, and the front end face of the adjusting bolt 13 pushes the brake shoe 6, thereby realizing the manual adjustment of the brake clearance.

[0018] Figure 1The automatic adjustment structure shown consists of a perforated sleeve 3, a transmission sleeve 4, a one-way bearing 8, a clutch shaft 9, and a transmission piston 17. The perforated sleeve 3 is fixedly connected to the brake base and is coaxial with the internal threaded sleeve 14. The transmission sleeve 4 is slidably fitted in the perforated sleeve 3, and the end face of the tail rod of the brake shoe 6 abuts against the front face of the transmission sleeve 4. The tail of the transmission sleeve 4 has a shaft hole, and the outer circumferential surface of the transmission sleeve 4 has a spiral groove 15. The pin 2 passes through the pin hole on the inner wall of the perforated sleeve 3. The pin 2 is locked in the pin hole within the spiral groove 15; the one-way bearing 8 is disposed in the shaft hole of the transmission sleeve 4, with the outer ring of the one-way bearing 8 in static fit with the transmission sleeve 4; the front section of the clutch shaft 9 is fitted into the inner ring of the one-way bearing 8, enabling a one-way rotational fit between the transmission sleeve 4 and the clutch shaft 9; the tail end face of the clutch shaft 9 and the front end face of the transmission piston 17 are engaged by bevel teeth 11 in a clutch structure, allowing the clutch shaft 9 and the transmission piston 17 to engage via the bevel teeth. During engagement, they drive each other and can also disengage the bevel gear engagement between the clutch shaft 9 and the transmission piston 17. The clutch shaft 9 has a central shaft hole, through which the fixing bolt 5 passes and is threaded to the internal thread hole on the end face of the transmission piston 17. The central shaft hole of the clutch shaft 9 is a stepped hole at the front end, and the internal compression spring 7 is pressed into the stepped hole of the clutch shaft 9 by the fixing bolt 5. The transmission piston 17 abuts against the front end of the adjusting bolt 13 with its large diameter outer ring surface at the front end. The small diameter body section of the transmission piston 17 is installed in the inner hole of the adjusting bolt 13, so that the transmission piston 17 and the adjusting bolt 13 form an axial sliding fit. A bottom compression spring 10 is set in the inner hole of the adjusting bolt 13. The tail end face of the transmission piston 17 abuts against the bottom compression spring 10 to obtain axial elastic force. A through groove 19 is machined in the center of the transmission piston 17. The pin 18 passes through the through groove 19 and is engaged with the adjusting bolt 13, so that the transmission piston 17 and the adjusting bolt 13 are linked circumferentially.

[0019] In practice, the corresponding technical measures also include:

[0020] A set clearance is maintained between the pin 2 and the spiral groove 15 to ensure the normal clearance between the brake shoes and the brake drum. A dial 12 is provided on the outer circumference of the adjusting bolt 13. The axial position of the adjusting bolt 13 in the internal thread sleeve 14 is adjusted by rotating the dial 12. The dial 12 is provided for easy operation, and the dial 12 and the adjusting bolt 13 are connected by a key. The internal thread sleeve 14 and the smooth hole sleeve 3 are integral components, making the adjustment mechanism compact and easy to assemble. The bevel gear engagement clutch structure sets the end face of the clutch shaft 9 as an external bevel gear surface and the end face of the transmission piston 17 as an internal bevel gear surface. Engagement is formed between the external and internal bevel gear surfaces. When the bevel gears are engaged, the clutch shaft 9 and the transmission piston 17 drive each other. When the bevel gears are disengaged, the clutch shaft 9 and the transmission piston 17 rotate relatively independently.

[0021] When braking is applied during normal intervals, wheel cylinder 1 is pushed by hydraulic oil... Figure 1 The brake shoe 6 is pushed to the right in the direction indicated by the middle arrow (to the right). Under the action of the bottom spring 10, the transmission piston 17 pushes the clutch shaft 9, and the transmission sleeve 4 moves to the right in a straight line until the front end face of the transmission sleeve 4 moves to position a1. The distance the front end face of the transmission sleeve moves is L1. At this time, the set gap between the spiral groove 15 and the pin 2 is eliminated. That is to say, the set gap between the spiral groove 15 and the pin 2 is equal to the value of L1, thereby ensuring that the normal braking gap is not recorded and adjusted.

[0022] When braking is applied due to increased brake shoe wear clearance, the normal clearance is first eliminated using the set clearance between the spiral groove 15 and the pin 2, i.e., the front end face of the transmission sleeve 4 moves to position a1. Due to the increased wear clearance, the wheel cylinder continues to push the brake shoe to the right until the front end face of the transmission sleeve 4 moves to position a2, with a movement distance of L2. At this time, under the constraint of the spiral groove 15 and the pin 2, the transmission sleeve 4 simultaneously generates a certain angle of right rotation. This right rotation drives the one-way bearing 8 to rotate at a corresponding angle on the outer diameter of the clutch shaft 9, thereby recording the brake shoe wear clearance. The automatic adjustment mechanism is then in a pre-adjustment state.

[0023] When the brake is released, the pressure of the hydraulic oil decreases, and the brake shoe 6 begins to return to its original position under the action of the tension spring 16. At the same time, the transmission sleeve 4 is also pushed back to its initial position. During the return process, the transmission sleeve 4 rotates to the left due to the action of the spiral groove 15 and the pin 2, causing the one-way bearing 8 inside the transmission sleeve 4 to grip the clutch shaft 9 and rotate to the left together. The clutch shaft 9 drives the transmission piston 17 through the bevel teeth 11. The transmission piston 17 drives the adjusting bolt 13 to rotate in the internal threaded sleeve 14 through the pin 18 and extend a certain distance. Under the resistance of the rightward-moving adjusting bolt, the brake shoe 6 can no longer return to its original position. The brake shoe approaches the brake drum, which reduces the brake clearance and achieves the purpose of automatic adjustment.

[0024] When maintenance or replacement of brake pads is required to increase the brake clearance, the dial 12 is manually turned, which drives the adjusting bolt 13 to rotate. This, in turn, drives the transmission piston 17 to rotate via the pin 18, causing the bevel teeth 11 between the clutch shaft 9 and the transmission piston 17 to separate, thereby increasing the brake clearance. This greatly facilitates the disassembly, maintenance, and repair of the brake drum.

Claims

1. A self-adjusting hydraulic brake brake gap adjustment mechanism comprising a wheel cylinder (1) and a brake shoe (6); characterized by: The adjustment mechanism includes a manual adjustment structure and an automatic adjustment structure. The manual adjustment structure consists of an internal threaded sleeve (14) and an adjusting bolt (13). The internal threaded sleeve (14) is fixedly connected to the brake base, and the adjusting bolt (13) is threadedly connected to the internal threaded sleeve (14). By adjusting the axial position of the adjusting bolt (13) in the internal threaded sleeve (14), the axial position of the front end face of the adjusting bolt (13) is changed, thereby adjusting the brake clearance. The automatic adjustment structure consists of a perforated sleeve (3), a transmission sleeve (4), a one-way bearing (8), a clutch shaft (9), and a transmission piston (17). The perforated sleeve (3) is connected to the brake base. The base is fixedly connected and coaxial with the internal threaded sleeve (14); the transmission sleeve (4) is slidably fitted in the perforated sleeve (3), and the tail end face of the brake shoe (6) abuts against the front end face of the transmission sleeve (4); the tail of the transmission sleeve (4) has a shaft hole, and the outer circumferential surface of the transmission sleeve (4) has a spiral groove (15), and the pin (2) passes through the pin hole on the inner wall of the perforated sleeve (3) and is engaged in the spiral groove (15); the one-way bearing (8) is set in the shaft hole of the transmission sleeve (4), the outer ring of the one-way bearing (8) is statically fitted with the transmission sleeve (4), and the front part of the clutch shaft (9) is fitted in the inner ring of the one-way bearing (8), so that the transmission sleeve (4) and the clutch shaft are engaged. (9) are in a one-way rotational fit; the tail end face of the clutch shaft (9) and the front end face of the transmission piston (17) are a bevel gear meshing clutch structure, which enables the clutch shaft (9) and the transmission piston (17) to drive each other when the bevel gears are meshing, and also enables the clutch shaft (9) and the transmission piston (17) to disengage from the bevel gear meshing; the clutch shaft (9) has a central shaft hole, and the fixing bolt (5) passes through the central shaft hole of the clutch shaft (9) and is threadedly connected to the internal thread hole provided on the end face of the transmission piston (17); the central shaft hole of the clutch shaft (9) is a stepped hole at the front end, and the internal hole compression spring (7) is pressed into the step of the clutch shaft (9) by the fixing bolt (5). In the hole; the transmission piston (17) with its large diameter outer ring surface at the front end abuts against the front end of the adjusting bolt (13), the small diameter body section of the transmission piston (17) is installed in the inner hole of the adjusting bolt (13), so that the transmission piston (17) and the adjusting bolt (13) form an axial sliding fit. A hole bottom compression spring (10) is set in the inner hole of the adjusting bolt (13), and the tail end face of the transmission piston (17) abuts against the hole bottom compression spring (10) to obtain axial elastic force. A through groove (19) is machined in the center of the transmission piston (17), and the pin (18) passes through the through groove (19) and is engaged with the adjusting bolt (13), so that the transmission piston (17) and the adjusting bolt (13) are linked circumferentially.

2. The self-adjusting hydraulic brake brake lash adjustment mechanism of claim 1 wherein There is a set clearance between the pin (2) and the spiral groove (15).

3. The self-adjusting hydraulic brake lash adjustment mechanism of claim 1 wherein A dial (12) is provided on the outer circumference of the adjusting bolt (13), and the axial position of the adjusting bolt (13) in the internal threaded sleeve (14) is adjusted by rotating the dial (12).

4. The self-adjusting hydraulic brake lash adjustment mechanism of claim 1, wherein The internal threaded sleeve (14) and the smooth hole sleeve (3) are integral components.

5. The self-adjusting hydraulic brake brake lash adjustment mechanism of claim 1 wherein The bevel gear meshing clutch structure is to set the end face of the clutch shaft (9) as the outer bevel gear surface and the end face of the transmission piston (17) as the inner bevel gear surface, so that meshing is formed between the outer bevel gear surface and the inner bevel gear surface.

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