阅读说明：本技术 带驻车功能的双缸双向双领蹄式鼓式可自调的制动器 (Double-cylinder bidirectional double-collar shoe type drum self-adjustable brake with parking function ) 是由 黄东方 胡凯 汪永胜 黄国兴 黄伟杰 朱子亨 凌利峰 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种带驻车功能的双缸双向双领蹄式鼓式可自调的制动器。制动底板总成的两侧安装前后置蹄总成,之间安装连接有轮缸总成和制动蹄回位弹簧,轮缸总成和制动蹄回位弹簧下方的前后置蹄总成上部之间安装驻车自调机构,前后置蹄总成下部之间安装连接有自调轮缸总成和驻车拉索；驻车自调机构中,调隙板铰接安装在推板的一端,用板销穿过推板和调隙板上各自的销孔将推板和调隙板之间铰接,推板和调隙板之间通过齿啮合；拉紧弹簧一端与板销钩接,用拉紧弹簧另一端越过调隙板后钩接到推板的弹簧接孔处。本发明能够使带有自增力式鼓式制动器的车辆可以实现手动驻车,省去了单独开发驻车装置的费用,且可靠度高。(The invention discloses a double-cylinder bidirectional double-collar shoe type drum self-adjustable brake with a parking function. Front and rear shoe assemblies are arranged on two sides of the brake bottom plate assembly, a wheel cylinder assembly and a brake shoe return spring are arranged and connected between the front and rear shoe assemblies, a parking self-adjusting mechanism is arranged between the upper parts of the front and rear shoe assemblies below the wheel cylinder assembly and the brake shoe return spring, and a self-adjusting wheel cylinder assembly and a parking cable are arranged and connected between the lower parts of the front and rear shoe assemblies; in the parking self-adjusting mechanism, a gap adjusting plate is hinged to one end of a push plate, a plate pin penetrates through respective pin holes in the push plate and the gap adjusting plate to hinge the push plate and the gap adjusting plate, and the push plate and the gap adjusting plate are meshed through teeth; one end of the tension spring is hooked with the plate pin, and the other end of the tension spring passes through the gap adjusting plate and then is hooked at the spring connecting hole of the push plate. The invention can realize manual parking of the vehicle with the self-boosting drum brake, saves the cost of independently developing a parking device and has high reliability.)

1. The utility model provides a but take two-way two lead hoof formula drum-type self-modulation's of double-cylinder of parking function stopper which characterized in that:

the brake comprises a brake bottom plate assembly (1), a front shoe assembly (2), a wheel cylinder assembly (3), a rear shoe assembly (4), a parking self-regulating mechanism (5), a brake shoe return spring (6), a self-regulating wheel cylinder assembly (7), a brake drum (10) and a parking cable (8); a front shoe assembly (2) and a rear shoe assembly (4) are arranged on two sides of a brake bottom plate assembly (1), a wheel cylinder assembly (3) and a brake shoe return spring (6) are arranged and connected between the upper parts of the front shoe assembly (2) and the rear shoe assembly (4), a parking self-regulating mechanism (5) is arranged between the front shoe assembly (2) and the upper part of the rear shoe assembly (4) below the wheel cylinder assembly (3) and the brake shoe return spring (6), and a self-regulating wheel cylinder assembly (7) and a parking cable (8) are arranged and connected between the lower parts of the front shoe assembly (2) and the rear shoe assembly (4);

the parking self-adjusting mechanism (5) comprises a tension spring (21), a push plate (19), a gap adjusting plate (20) and a plate pin (22), wherein the gap adjusting plate (20) is hinged to one end of the push plate (19), the plate pin (22) penetrates through respective pin holes in the push plate (19) and the gap adjusting plate (20) to hinge the push plate (19) and the gap adjusting plate (20), and the push plate (19) and the gap adjusting plate (20) are meshed through teeth to form a tooth meshing pair; one end of a tension spring (21) is hooked with a plate pin (22), a spring connecting hole is formed in the middle of a push plate (19) close to the gap adjusting plate (20), and the other end of the tension spring (21) is hooked to the spring connecting hole of the push plate (19) after passing through the gap adjusting plate (20).

2. The double-cylinder bidirectional double-collar shoe type drum self-adjustable brake with the parking function as claimed in claim 1, wherein: the pin holes on the push plate (19) are kidney-shaped holes (K), and the plate pins (22) are movably matched with the pin holes on the push plate (19); the pin holes on the gap adjusting plate (20) are round holes (M), and the plate pin (22) is in interference fit with the pin holes on the gap adjusting plate (20).

3. The double-cylinder bidirectional double-collar shoe type drum self-adjustable brake with the parking function as claimed in claim 1, wherein: push pedal (19) divide into major structure and the structure that sinks, adjust crack board (20) department at the installation and set up to the structure that sinks, it transfers crack board (20) to sink structural articulated installation, transfer crack board (20) and process for the circular arc tooth near push pedal (19) major structure's side, the major structure of push pedal (19) is equipped with other convex part in the one end of being connected with the structure that sinks, other convex part side processing is the arc tooth, the arc tooth of the other convex part of push pedal (19) is used for and transfers the circular arc tooth meshing of crack board (20) to be connected, the tooth meshing pair of formation is used for self-modulation and adjusts spacingly.

4. The double-cylinder bidirectional double-collar shoe type drum self-adjustable brake with the parking function as claimed in claim 1, wherein: the gap adjusting device is characterized by further comprising a limiting spring (18), the other end of the push plate (19) of the gap unadjusted plate (20) is provided with the limiting spring (18), and the limiting spring (18) is hooked to a hooking hole (H) formed in the other end of the push plate (19).

5. The double-cylinder bidirectional double-collar shoe type drum self-adjustable brake with the parking function as claimed in claim 1, wherein: the parking self-adjusting mechanism is arranged between the upper parts of the front shoe assembly (2) and the rear shoe assembly (4).

6. The double-cylinder bidirectional double-collar shoe type drum self-adjustable brake with the parking function as claimed in claim 5, wherein: and one end of the gap adjusting plate (20) far away from the tooth meshing pair is provided with a hook-shaped structure which is hooked into a limiting groove (F) formed in the upper part of the front shoe assembly (2), the end part of the other end of the push plate (19) which is not connected with the gap adjusting plate (20) is provided with a push plate notch (B), and a tendon of the rear shoe assembly (4) is clamped and embedded in the push plate notch (B).

7. The double-cylinder bidirectional double-collar shoe type drum self-adjustable brake with the parking function as claimed in claim 1, wherein: the rear hoof assembly (4) is further provided with a parking pull arm (24), the parking pull arm (24) is hinged to a tendon of the rear hoof assembly (4) through a pull arm pin (23), and the pull arm pin (23) penetrates through the tendon of the rear hoof assembly (4) and then is provided with a check ring (25) for axial limiting installation.

8. The double-cylinder bidirectional double-collar shoe type drum self-adjustable brake with the parking function as claimed in claim 3, wherein: the circle center of the circular arc tooth is positioned on the central axis of the plate pin (22).

Technical Field

The invention relates to a hydraulically-triggered double-cylinder bidirectional double-collar shoe type drum self-adjustable brake, in particular to a double-cylinder bidirectional double-collar shoe type drum self-adjustable brake with a parking function.

Background

The hydraulic double-cylinder bidirectional double-collar shoe type drum brake is mainly used on engineering vehicles and trailers with large loads and slow speeds, the braking is required to be effective and stable, and the self-energizing drum brake with the clearance self-adjusting function can well meet the use requirements of the vehicles.

However, the working environment of a conventional engineering truck or trailer is relatively severe, and the conventional self-boosting drum brake may be used on a steep mountain road or an uneven building site, and has high service braking efficiency and good reliability under a common condition. However, the mechanical parking (hand brake) device of such vehicles is often realized by a separate device, which results in:

firstly, the cost is higher: the mechanical parking device is independently designed and needs a special structure to realize, so that the cost is high;

secondly, the space utilization rate is low: the arrangement of the mechanical parking device needs to consider the spatial arrangement of the whole chassis, specially divide the position for placing the mechanical parking device and consider the connection problem of the peripheral related peripheral parts;

thirdly, the maintenance cost is high: the single mechanical parking device needs to be additionally maintained, and the maintenance cost is high;

in view of the above, in combination with the structure and function of the drum brake, the drum brake itself can integrate the service brake and the parking brake, but since the self-energizing drum brake has a compact structure, the space after the function device of the clearance self-adjusting mechanism is added is more complicated, and the arrangement of the manual parking device becomes more difficult.

Disclosure of Invention

In order to solve the problem of resource and cost waste caused by the fact that a hand parking brake device is designed independently in the prior art, the invention aims to provide a self-adjustable double-cylinder bidirectional double-collar shoe type drum brake with a parking function, so that a mechanical brake device is added to the bidirectional double-collar shoe type drum brake on the basis of the conventional service brake function, two functions of service and parking can be realized simultaneously on the premise that a vehicle of the bidirectional double-collar shoe type drum brake can directly adopt one set of brake, the parking is carried out by directly adopting the structure without influencing the original service brake, and the cost and the space can be saved.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the brake comprises a brake bottom plate assembly, a front shoe assembly, a wheel cylinder assembly, a rear shoe assembly, a parking self-regulating mechanism, a brake shoe return spring, a self-regulating wheel cylinder assembly, a brake drum and a parking cable; a front shoe assembly and a rear shoe assembly are arranged on two sides of the brake bottom plate assembly, a wheel cylinder assembly and a brake shoe return spring are arranged between the front shoe assembly and the upper part of the rear shoe assembly, a parking self-adjusting mechanism is arranged between the front shoe assembly and the upper part of the rear shoe assembly below the wheel cylinder assembly and the brake shoe return spring, and a self-adjusting wheel cylinder assembly and a parking inhaul cable are arranged between the front shoe assembly and the lower part of the rear shoe assembly; the parking self-adjusting mechanism comprises a tension spring, a push plate, a gap adjusting plate and a plate pin, wherein the gap adjusting plate is hinged to one end of the push plate, the plate pin penetrates through respective pin holes in the push plate and the gap adjusting plate to hinge the push plate and the gap adjusting plate, and the push plate and the gap adjusting plate are meshed through teeth to form a tooth meshing pair; one end of the tension spring is hooked with the plate pin, the middle part of the push plate close to the gap adjusting plate is provided with a spring connecting hole, and the other end of the tension spring passes through the gap adjusting plate and then is hooked at the spring connecting hole of the push plate.

The pin holes on the push plate are waist-shaped holes, and the plate pins are movably matched with the pin holes on the push plate; the pin holes on the gap adjusting plates are round holes, and the plate pins are in interference fit with the pin holes on the gap adjusting plates.

The push pedal divide into major structure and structure of sinking, transfer crack board department at the installation and set up to the structure of sinking, the structural articulated installation of sinking transfers the crack board, transfer the crack board and process for the arc tooth near the side of push pedal major structure, the major structure of push pedal is equipped with other convex part in the one end of being connected with the structure of sinking, other convex part side is processed for the dogtooth, the arc tooth of the other convex part of push pedal is used for and transfers the arc tooth meshing of crack board to be connected, the tooth meshing pair of formation is used for self-modulation and adjusts spacingly.

The gap adjusting device further comprises a limiting spring, wherein the other end of the push plate without the gap adjusting plate is provided with the limiting spring, and the limiting spring is hooked to a hook-connecting hole formed in the other end of the push plate.

The parking self-adjusting mechanism is arranged between the tendons at the upper parts of the front shoe assembly and the rear shoe assembly.

The gap adjusting plate is provided with a hook-shaped structure at one end far away from the tooth meshing pair, the hook-shaped structure is hooked in a limiting groove formed in the upper portion of the front shoe assembly, a push plate notch is formed in the end portion, which is not connected with the gap adjusting plate, of the other end of the push plate, and a tendon of the rear shoe assembly is clamped and embedded in the push plate notch.

The rear hoof assembly is further provided with a parking pull arm, the parking pull arm is hinged to a tendon of the rear hoof assembly through a pull arm pin, and the pull arm pin penetrates through the tendon of the rear hoof assembly and then is provided with a check ring for axial limiting installation.

The circle center of the circular arc tooth is positioned on the central axis of the plate pin.

The invention comprises a brake device which can park on the basis of the running function of a bidirectional double-collar shoe type drum brake assembly, wherein the parking brake device is composed of a parking pull arm and related auxiliary parts, and the auxiliary parts comprise a pull arm pin for fixing the pull arm on a shoe rib and a check ring.

The invention is provided with a parking inhaul cable for driving the pull arm to rotate and a parking self-adjusting mechanism for transmitting motion.

The brake bottom plate assembly is fixed on the frame, the brake wheel cylinder is fixed on the bottom plate through a bolt, the rear brake shoe fixed with the parking pull arm is connected with the lower end of the front brake shoe through the self-adjusting wheel cylinder assembly, the upper end of the rear brake shoe is leaned against the brake wheel cylinder assembly, the pull arm is connected with the front brake shoe rib in the middle of the rear brake shoe, the pull arm is fixed on two sides of the wheel cylinder on the bottom plate assembly through the compression spring mechanism, one end of the inhaul cable is connected with the pull arm, and the other end of the inhaul cable is fixed on a parking handle of a cab. When the vehicle needs to be stably parked, the parking handle is pulled up, the inhaul cable is pulled to drive the pull arm to rotate, and then the inhaul cable is transmitted through the parking self-adjusting mechanism to enable the brake shoe to be opened and tightly pressed with the brake drum, so that the vehicle is parked.

The invention has the beneficial effects that:

the invention realizes that a double-cylinder bidirectional double-collar shoe type drum brake with a clearance self-adjusting function is additionally provided with a mechanical parking device, realizes that one double-cylinder bidirectional double-collar shoe type drum brake simultaneously realizes the functions of service braking and parking braking, and realizes the clearance self-adjustment of a friction plate and a brake drum.

Compared with a conventionally used double-cylinder bidirectional double-collar shoe type drum brake, the double-cylinder bidirectional double-collar shoe type drum brake integrates the functions of driving and parking, solves the problem of resource and cost waste caused by the fact that a hand parking brake device is separately designed in the prior art, can be used for parking reliably without influencing the original driving brake by directly adopting the structure, and saves cost and space.

The invention can realize manual parking of the vehicle with the self-boosting drum brake, saves the cost of independently developing a parking device and has high reliability.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a cross-sectional view of the self-alignment mechanism of fig. 1.

Fig. 3 is a back view of fig. 1.

Fig. 4 is a lower sectional view of fig. 1.

FIG. 5 is a three-dimensional schematic view of a brake shoe and shoe belt pull arm.

Fig. 6 is a schematic structural diagram of the self-adjusting mechanism of the present invention.

Fig. 7 is an exploded view of the self-alignment mechanism.

Fig. 8 is a cross-sectional view of the self-adjusting mechanism.

FIG. 9 is a plan view of the push plate.

In the figure: the brake device comprises a brake bottom plate assembly 1, a front shoe assembly 2, a wheel cylinder assembly 3, a rear shoe assembly 4, a self-adjusting mechanism 5, a brake shoe return spring 6, a self-adjusting wheel cylinder assembly 7, a parking cable 8, a front brake oil pipe assembly 9, a brake drum 10, a rear brake oil pipe assembly 11, a tee joint 12, a fastening bolt 13, a deflation screw 14, a spring pull rod 15, a pressure spring 16, a pressure spring seat 17, a limiting spring 18, a push plate 19, a gap adjusting plate 20, a tensioning spring 21, a plate pin 22, a pull arm pin 23, a parking pull arm 24 and a retainer ring 25.

Detailed Description

The invention is further described with reference to the accompanying drawings and the detailed description.

As shown in fig. 1 and 2, the embodied brake includes a brake shoe assembly 1, a front shoe assembly 2, a wheel cylinder assembly 3, a rear shoe assembly 4, a parking self-adjusting mechanism 5, a brake shoe return spring 6, a self-adjusting wheel cylinder assembly 7, a brake drum 10 and a parking cable 8; the brake base plate assembly 1 is installed on a frame, a front shoe assembly 2 and a rear shoe assembly 4 are installed on two sides of the brake base plate assembly 1, a wheel cylinder assembly 3 and a brake shoe return spring 6 are installed and connected between the front shoe assembly 2 and the upper portion of the rear shoe assembly 4, a parking self-adjusting mechanism 5 is installed between the front shoe assembly 2 and the upper portion of the rear shoe assembly 4 below the wheel cylinder assembly 3 and the brake shoe return spring 6, and a self-adjusting wheel cylinder assembly 7 and a parking inhaul cable 8 are installed and connected between the front shoe assembly 2 and the lower portion of the rear shoe assembly 4; one end of the parking cable 8 is sleeved at the point C at the tail end of the parking pull arm 24, and the other end of the parking cable is connected to the handle end of the vehicle chassis. The brake wheel cylinder assembly 3 and the self-adjusting wheel cylinder assembly 7 are fixedly arranged on the upper side and the lower side of the brake bottom plate assembly 1 and are fastened by fastening bolts 13; the upper ends of the front shoe assembly 2 and the rear shoe assembly 4 are connected to the clamping grooves on two sides of the brake wheel cylinder assembly 3, and the lower ends of the front shoe assembly and the rear shoe assembly are connected to the clamping grooves on two sides of the self-adjusting wheel cylinder assembly 7.

In the invention, one of two brake cylinders is a brake wheel cylinder assembly 3, and the other brake cylinder is a self-adjusting wheel cylinder assembly 7, one side of the brake wheel cylinder assembly 3 realizes automatic shoe drum clearance adjustment through a parking self-adjusting push plate assembly 5, and the other side of the brake wheel cylinder assembly 7 adjusts shoe drum clearance.

As shown in fig. 3 and 4, the brake further includes: the front shoe assembly 2 and the rear shoe assembly 4 are arranged on two sides of the end surface of the brake bottom plate assembly 1 through a mechanism consisting of a phase pressure spring pull rod 15, a pressure spring 16 and a pressure spring seat 17, one end of the phase pressure spring pull rod 15 is fixedly connected to the end surface of the brake bottom plate assembly 1, the other end of the phase pressure spring pull rod 15 penetrates through the front shoe assembly 2/the rear shoe assembly 4 to be connected with the pressure spring seat 17, and the pressure spring 16 is sleeved outside the phase pressure spring pull rod 15 between the pressure spring seat 17 and the front shoe assembly 2/the rear shoe assembly 4. And the air release screw 14 is arranged on the brake wheel cylinder assembly 3.

The brake wheel cylinder assembly 3 and the self-adjusting wheel cylinder assembly 7 are connected with the front brake oil pipe assembly 9, the rear brake oil pipe assembly 11 and the tee joint 12 in series, the brake wheel cylinder assembly 3 and the self-adjusting wheel cylinder assembly 7 are connected to the tee joint 12 through the front brake oil pipe assembly 9 and the rear brake oil pipe assembly 11 respectively, brake fluid is divided into the brake wheel cylinder assembly 3 and the self-adjusting wheel cylinder assembly 7 through the tee joint 12, pistons on two sides of the brake wheel cylinder assembly 3 and the self-adjusting wheel cylinder assembly 7 are opened to push the front shoe assembly 2 and the rear shoe assembly 4 to be opened to be attached to the brake drum 10, and service braking is achieved.

The parking brake device is formed by a parking pull arm 24 and related auxiliary parts, wherein the auxiliary parts comprise a pull arm pin 23, a check ring 25, a parking self-adjusting push plate assembly 5 and a parking inhaul cable 8.

As shown in fig. 5, the rear shoe assembly 4 is further provided with a parking pull arm 24, the parking pull arm 24 is hinged to a tendon of the rear shoe assembly 4 through a pull arm pin 23, and the pull arm pin 23 passes through the tendon of the rear shoe assembly 4 and then is provided with a retaining ring 25 for axial limiting installation.

When a parking handle of the vehicle is pulled up, the parking cable 8 is pulled to drive the parking pull arm 24 to rotate around the pull arm pin 23 of the rear shoe assembly 4, the parking self-adjusting mechanism 5 is pushed to move forwards, the front shoe assembly 2 moves forwards until the front shoe assembly 2 is attached to the brake drum 10, the parking pull arm 24 is continuously pulled to rotate, the rear shoe assembly 4 moves backwards to be pressed against the brake drum 10, and the vehicle is stably parked.

As shown in fig. 6 and 7, the parking self-adjusting mechanism 5 comprises a tension spring 21, a push plate 19, a gap adjusting plate 20 and a plate pin 22, wherein the gap adjusting plate 20 is hinged to one end of the push plate 19, the plate pin 22 penetrates through respective pin holes on the push plate 19 and the gap adjusting plate 20 to hinge the push plate 19 and the gap adjusting plate 20, and the push plate 19 and the gap adjusting plate 20 are meshed through teeth to form a tooth meshing pair; as shown in fig. 8, one end of the tension spring 21 is hooked with the plate pin 22, a spring connecting hole is formed in the middle of the push plate 19 close to the gap adjusting plate 20, the spring connecting hole is a through hole, and the other end of the tension spring 21 passes through the gap adjusting plate 20 and then is hooked at the spring connecting hole of the push plate 19.

As shown in fig. 9, the pin hole of the push plate 19 is a kidney-shaped hole K, and the length direction of the kidney-shaped hole K is along the connection direction between the front shoe assembly 2 and the rear shoe assembly 4, i.e., the length direction of the push plate 19. The plate pin 22 is in clearance fit with the pin hole on the push plate 19; the pin holes on the gap adjusting plate 20 are round holes M, and the plate pins 22 are tightly fitted with the pin holes on the gap adjusting plate 20.

The push plate 19 is divided into a main body structure and a sinking structure, the sinking structure is arranged at the position where the gap adjusting plate 20 is arranged, and the sinking structure and the main body structure part are not positioned on the same plane and are mutually parallel, staggered and integrally connected; the gap adjusting plate 20 is installed through pin holes with waist-shaped holes in a sinking structure in a hinged mode, the side face, close to the main structure of the push plate 19, of the gap adjusting plate 20 is machined into arc teeth, the circle center of each arc tooth is located on the central axis of the plate pin 22, a side convex portion is arranged at one end, connected with the sinking structure, of the main structure of the push plate 19, the side face of the side convex portion is close to the gap adjusting plate 20 and is machined into arc teeth, the arc teeth of the side convex portion of the push plate 19 are used for being meshed and connected with the arc teeth of the gap adjusting plate 20, and a formed tooth meshing pair is used for self-adjusting and adjusting limiting between the push plate 19 and the gap adjusting plate 20. During service braking, the arc-shaped teeth of the convex part beside the push plate 19 and the arc-shaped teeth of the gap adjusting plate 20 are disengaged; when the automobile is not braked, the arc teeth of the convex part beside the push plate 19 are meshed with the arc teeth of the gap adjusting plate 20.

The rear shoe assembly further comprises a limiting spring 18, the other end of the push plate 19 of the gap-unadjusted plate 20 is provided with the limiting spring 18, one end of the limiting spring 18 is hooked to a hooking hole H formed in the other end of the push plate 19, the hooking hole H is a through hole, and the other end of the limiting spring 18 is hooked to a hole J formed in the upper portion of a tendon of the rear shoe assembly 4.

As shown in fig. 2 and 6, a gap adjusting plate 20 is provided with a hook-shaped structure at one end far away from the tooth meshing pair, the hook-shaped structure is located at the upper side of a point G in fig. 6, and the hook-shaped structure is hooked into a strip-shaped limiting groove F formed in the upper part of the front shoe assembly 2 to prevent the parking self-adjusting mechanism from falling off from the limiting groove F of the front shoe assembly 2 in the adjusting process; the push plate 19 is provided with a push plate notch B at the other end part which is not provided with the gap adjusting plate 20, and the tendon of the rear hoof assembly 4 is clamped and embedded in the push plate notch B.

Therefore, the upper ends of the front shoe assembly and the rear shoe assembly are connected to clamping grooves on two sides of the brake wheel cylinder assembly, the lower ends of the front shoe assembly and the rear shoe assembly are connected to clamping grooves on two sides of the self-adjusting wheel cylinder assembly and are installed on two sides of the end face of the brake bottom plate assembly through the same pressure spring mechanisms, the parking pull arm is hinged to a rear shoe rib hole of the rear brake shoe assembly through a pull arm pin and is fixed and limited through a check ring, and the end A of the gap adjusting plate 20 is clamped into a limiting groove F of the front shoe assembly.

The parking draw arm and the rear brake shoe assembly are clamped into a push plate notch B, the parking self-adjusting mechanism and the rear brake shoe assembly are hooked by a limiting spring at the same time, the parking self-adjusting mechanism and the rear brake shoe assembly are connected together and do not fall off, the self-adjusting function is realized by moving a notch on the front brake shoe assembly, and the parking self-adjusting mechanism does not fall off in the working process by tensioning the front brake shoe assembly and the rear brake shoe assembly through two brake shoe return springs.

The implementation working process of the invention is as follows:

when the automobile is braked, the front shoe assembly 2 and the rear shoe assembly 4 are separated from each other to two sides by the thrust of a wheel cylinder piston of the wheel cylinder assembly 3, self-adjustment is carried out at the moment, a limiting groove F on the front shoe assembly 2 is connected with an E point of the gap adjusting plate 20 in a clamping mode, the front shoe assembly 2 and the rear shoe assembly 4 are controlled to be separated and opened to an adjusting distance under the limiting effect of the self-adjusting structure 5, and the separation motion is divided into two stages:

the first stage is as follows: through the separation and the opening of the pistons at the two ends of the wheel cylinder assembly 3 against the front shoe assembly 2 and the rear shoe assembly 4, the plate pin 22 overcomes the spring force of the tension spring 21 and moves close to the front shoe assembly 2 in the kidney-shaped hole on the push plate 19 until the position closest to the front shoe assembly 2 in the kidney-shaped hole is taken as a limit position, namely the plate pin 22 also moves to the leftmost side in the kidney-shaped hole on the push plate 19, at the moment, the point E in the figure 6 is driven by the front shoe assembly 2 to the leftmost side in the figure 6, and the gap adjusting plate 20 also moves in parallel to the leftmost side; meanwhile, the push plate 19 is moved towards the direction close to the rear shoe assembly 4 under the force of the limiting spring 18, namely, moved towards the right side in the figure 6;

after the first stage is finished, the gap adjusting plate 20 is just separated from the meshing teeth on the push plate 19;

and a second stage: when the front shoe assembly 2 and the rear shoe assembly 4 are worn, the front shoe assembly 2 and the rear shoe assembly 4 continue to move in a separating mode, the gap adjusting plate 20 is driven to rotate around the central axis of the plate pin 22, the G point of the gap adjusting plate 20 at the limit position of the kidney-shaped hole moves to the L point, and the tooth meshing position between the push plate 19 and the gap adjusting plate 20 is driven to deflect;

when the automobile is not braked, the wheel cylinder assembly 3 does not work to release pressure, the brake shoes of the front shoe assembly 2 and the rear shoe assembly 4 return under the spring force of the brake shoe return spring 6, the parking self-adjusting mechanism 5 returns through the force of the tension spring 21 to drive the gap adjusting plate 20 and the push plate 19 to return and approach until the push plate 19 and the gap adjusting plate 20 are driven to be meshed with each other again, at the moment, self-adjustment is completed, the distance from the point G to the point L is the distance for realizing self-adjustment, and the gap X between the front friction plate and the brake drum and the gap X between the rear friction plate and the brake drum are adjusted.

Therefore, the invention integrates the functions of driving and parking, solves the problem of resource and cost waste caused by the independent design of a hand parking brake device in the prior art, and can reliably park without influencing the original driving brake by directly adopting the structure, thereby saving the cost and the space.

The above examples are illustrative of the present invention and are not intended to be limiting, and any simple modification of the present invention is within the scope of the present invention.