Structure of hydraulic braking system

Abstract

The utility model discloses a hydraulic brake system structure which comprises a support assembly, an adjusting mechanism, a brake switch, a multi-friction-plate wet brake, a hand brake operating lever assembly, an energy accumulator and two brake pumps. The two brake pumps are fixed to the support assembly through bolts. The adjusting mechanism can move back and forth on the support assembly. A pedal plate on the support assembly moves, and brake oil in a piston extrusion pipeline in a brake pump flows to a left multi-friction-plate wet brake and a right multi-friction-plate wet brake which are arranged on an input transmission shaft of a planetary mechanism in a rear axle shell through a brake switch; the hose and the hard conduit are connected between the brake pump and the brake switch; the hose and the hard conduit are connected between the brake switch and the wet brake. According to the utility model, large braking force and good accurate braking performance can be exerted under the action of relatively small braking pedal force; a satisfactory man-machine engineering state is achieved by adjusting the support assembly for fixing the pedal to move back and forth; the number of parts is reduced, and cost is reduced.

Description

Technical Field

[0001] The utility model relates to a component of a tractor, in particular to a structure of a hydraulic brake system. Background Art

[0002] With the increasing trend of the total mass and speed of tractors, without a brake booster, the driver's pedal force may not meet the required braking force or the pedal braking force may be too large. Therefore, for a brake system that directly installs the service brake on the rear drive shaft, the user's braking comfort is very poor. Usually, the position of the service brake pedal is fixed, and it is difficult to achieve the best pedal position due to different physical differences of customers, and it is impossible to achieve satisfactory ergonomics.

[0003] Currently, the parking mechanism and parking control of tractors on the market are mostly arranged independently and separated from the driving brake mechanism, resulting in a complex braking system structure, a large number of parts and high costs. Utility Model Content

[0004] In view of the above situation, in order to overcome the defects of the prior art, the utility model provides a structure of a hydraulic brake system that can exert large braking force and good precision braking performance under relatively small brake pedal force, and the adopted adjustment mechanism can make the support assembly of the fixed foot pedal move forward and backward to meet the needs of different users and achieve a satisfactory ergonomic state; a handbrake lever assembly is arranged in the adopted brake switch to realize the parking function, maximize the sharing of components of the driving brake system, simplify the brake structure, and reduce the cost of the hydraulic brake system.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a structure of a hydraulic brake system, including a support assembly, an adjustment mechanism, a brake switch, a multi-friction plate wet brake, a handbrake lever assembly, an accumulator, and two brake pumps, wherein the two brake pumps are fixed to the support assembly by bolts; four bolts are fixed vertically to the driving floor through the elliptical holes of the support assembly; the adjustment mechanism can move forward and backward on the support assembly; when the pedal on the support assembly moves, the piston in the brake pump squeezes the brake oil in the pipeline through the brake switch and flows to the left and right two multi-friction plate wet brakes arranged on the input transmission shaft of the planetary mechanism in the rear axle housing; a first hose and a first hard conduit are connected between the brake pump and the brake switch; and a second hose and a second hard conduit are connected between the brake switch and the wet brake.

[0006] Preferably, the brake switch adopts a dual-circuit brake switch, whose two oil inlets are connected to the oil circuit and the accumulator through the oil pipe. When the brake system pressure is abnormal, the hydraulic oil is supplemented to ensure effective braking pressure.

[0007] Preferably, the handbrake lever assembly is connected to the brake switch via a steel cable, and the handbrake is returned via a return spring.

[0008] Preferably, the parking brake operation includes a handle assembly, an outer cylinder, screws, springs, plugs, and steel cables. The outer cylinder is installed on the driving floor, and the handle assembly is inside the outer cylinder, connected to the support arm of the brake switch through a steel cable with a slide rod end: push the handle assembly down to release the brake; lift the handle assembly up to brake, then turn right 90° to lock it, and then step on the brake pedal to realize the parking stop function. When releasing the parking brake, just release the handle assembly and the return spring will pull the support arm back to its original position.

[0009] Preferably, the adjustment mechanism includes a rotating handle bolt and a rocker arm installed on the handle threaded shaft, which swings in a circle with the positioning shaft as the axis, and realizes the front and rear movement of the support assembly through the pin, connecting rod and pin. The user can adjust the front and rear position of the support assembly where the foot pedal is installed according to different physical needs to achieve a comfortable operating state and reduce driving fatigue.

[0010] Preferably, the dual-way brake switch is composed of two two-position two-way valve-type switches with exactly the same structure, including a housing, a push rod, a valve seat, a first spring, a second spring, a valve assembly, a guide sleeve, a fixing plate, a cam mechanism, an end cover assembly, and a support arm; the dual-way brake switch connects or disconnects the hydraulic oil circuit between the brake pump and the brake, and can maintain the hydraulic pressure of the two-way brake system pipelines to maintain the required brake pressure.

[0011] Preferably, the double chambers can work synchronously through the cam mechanism. When the cam mechanism is operated to rotate 90° along the opening direction, the valve can move from the locked position to the open position. When the valve is locked, it is equivalent to a one-way valve. At this time, the working hydraulic oil can only reach the brake through the valve and cannot flow back, so it can maintain the pressure of the brake and realize the parking brake function; in the other position, that is, the valve open position, the dual-way brake switch is equivalent to two channels; the cam mechanism is centered by the fixed plate, its working surface is in contact with the push rod, and is connected to the shell by two M4 screws by the end cover assembly and fixed between the shell and the end cover assembly, with a rotation working angle of 90°; by operating the support arm and the cam mechanism, the push rod will move up and down to open or close the valve assembly, and its double chambers work synchronously. The cam mechanism has a symmetrical working surface and has the function of simultaneously locking the braking pressure of the two channels.

[0012] Preferably, a brake pressure proportional to the operating force is provided to the brake system through a brake pump. Each machine is equipped with two brake pumps. The upper part is an air bleed nozzle assembly and an oil storage chamber, and an observation window is provided for observing the oil storage condition of the oil storage chamber. The lower part has an external output oil circuit and a double-ear mounting hole. The driver applies force to the piston rod through the foot pedal to move the piston rod downward and compress the oil, which will provide the vehicle braking system with a brake pressure proportional to the operating pedal force, thereby realizing the braking function; when the operating force is released, the brake pressure disappears.

[0013] Preferably, the left and right multi-friction plate wet brakes are respectively installed in the left and right rear axle housings, and are arranged on the left and right planetary mechanism input drive shafts. The multi-friction plate wet brakes are composed of two pairs of symmetrically arranged pistons, brake discs, friction disc assemblies, and return assemblies. The hydraulic pressure acts on the pistons, so that the friction disc assembly is clamped between the brake disc and the piston to realize the braking function.

[0014] The utility model can exert a large braking force and good precise braking performance under the action of a relatively small brake pedal force; a satisfactory ergonomic state is achieved by adjusting the support assembly of the fixed foot pedal to move forward and backward; the parking brake mechanism shares the parts of the driving brake system to the greatest extent, reduces the number of parts, and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation to the present invention.

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 It is a top view schematic diagram of the utility model;

[0018] Figure 3 for Figure 2 Middle AA section view;

[0019] Figure 4 for Figure 2 Middle EE section view;

[0020] Figure 5 for Figure 1 Middle FF section view;

[0021] Figure 6 It is a partial cross-sectional view of the brake switch in the utility model;

[0022] Figure 7 It is a cross-sectional view of the brake pump in the utility model;

[0023] Figure 8This is a braking principle diagram of the utility model. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments; based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0025] like Figure 1-8 As shown, a structure of a hydraulic brake system has two independent hydraulic circuits, which can realize three braking functions: single-side wheel braking, simultaneous braking while driving, and hand brake parking. With separate brake pedals, the tractor can realize single-side wheel braking when working in the field, and can realize a small radius of circumferential head rotation at the head of the field. When the tractor is driving on the road, the two brake pedals are mechanically connected together to realize the simultaneous braking function. Lifting the parking brake handle and rotating it 90° clockwise can maintain the oil pressure in the brake hydraulic pipeline and realize the parking stop function.

[0026] The structure of the hydraulic brake system includes a support assembly 1, two brake pumps 2, an adjustment mechanism 3, a brake switch 4, a multi-friction plate wet brake 5, a handbrake lever assembly 6, and an accumulator 7. The two brake pumps 2 are fixed to the support assembly 1 by bolts; four bolts are fixed vertically to the driving floor 40 through the elliptical holes of the support assembly 1; the support assembly 1 is moved forward and backward by rotating the handle of the adjustment mechanism 3; the pedal 8 on the support assembly 1 moves, and the piston in the brake pump 2 squeezes the brake oil in the pipeline through the brake switch 4 and flows to the left and right multi-friction plate wet brakes 5 arranged on the input transmission shaft of the planetary mechanism in the rear axle housing 9; the first hose 10 and the first hard conduit 11 are connected between the brake pump and the brake switch; the second hose 12 and the second hard conduit 13 are connected between the brake switch 4 and the wet brake 5.

[0027] The brake switch 4 adopts a dual-circuit brake switch. The two oil inlets are connected to the oil line through the oil pipe 39 to the accumulator 7. When the brake system pressure is abnormal, the hydraulic oil is supplemented to ensure effective brake pressure. The handbrake lever assembly 6 is connected to the brake switch 4 through the steel cable 14, and the handbrake is returned by the return spring 15. Normal braking is often used for deceleration during the driving of the tractor. The force applied by the driver on the left and right foot pedals 9 is the same, and the brake pressure is proportional to the force applied on the foot pedal 8. When the foot pedal 8 is stepped on, the piston rod of the brake pump 2 moves downward to increase the pressure of the corresponding system; the brake pressure will change accordingly by changing the force applied to the foot pedal 8. Differential braking is often used for turning when the tractor is driving, and the force applied by the driver on the left and right foot pedals 8 is different. Parking brake operation: including handle assembly 48, outer cylinder 49, screw 50, spring 51, screw plug 52, and steel cable 14. The outer cylinder 49 is installed on the driving floor 40, and the handle assembly 48 is inside the outer cylinder 49, and is connected to the support arm 32 of the brake switch 4 through a steel cable 14 with a slide rod end: push the handle assembly 48 down to release the brake; lift the handle assembly 48 up to apply the brake, then turn it 90 degrees to the right to lock it, and then step on the brake pedal to realize the parking function. When releasing the parking brake, just release the handle assembly 48, and the return spring 15 will pull the support arm 32 back to its original position.

[0028] The adjustment mechanism mainly includes a rotating handle bolt 16, a rocker arm 17 installed on the handle threaded shaft, and a positioning shaft 18 as the axis, which swings in a circle and moves the support assembly 1 forward and backward through the pin 19, the connecting rod 20 and the pin 2 21. The user can adjust the front and rear position of the support assembly 1 where the foot pedal 8 is installed according to different physical needs to achieve a comfortable operating state and reduce driving fatigue.

[0029] The dual-way brake switch is composed of two two-position two-way valve switches with the same structure, which connect or disconnect the hydraulic oil circuit between the brake pump and the brake, and can maintain the hydraulic pressure of the two-way brake system pipelines to maintain the required brake pressure. The cam mechanism 30 can make the double chambers work synchronously. When the cam mechanism 30 is operated to rotate 90° along the opening, the valve can be moved from the locked position to the open position. When the valve is locked, it is equivalent to a one-way valve. At this time, the working hydraulic oil can only reach the brake 5 through the valve, but cannot flow back, so it can maintain the pressure of the brake and realize the parking brake function; in the other position, that is, the valve open position, the dual-way brake switch is equivalent to two channels. The dual-way brake switch is mainly composed of a housing 22, a push rod 23, a valve seat 26, a spring 25, a spring 27, a valve assembly 28, a guide sleeve 24, a fixing plate 29, a cam mechanism 30, an end cover assembly 31, and a support arm 32. The cam mechanism 30 is centered by the fixing plate 29, and its working surface contacts the push rod 23. It is connected to the housing 22 by the end cover assembly 31 through two M4 screws and fixed between the housing 22 and the end cover assembly 31, with a 90° rotation working angle. By operating the arm 32 and the cam mechanism 30, the push rod 23 will move up and down to open or close the valve assembly 28. Its double chambers work synchronously. The cam mechanism 30 has a symmetrical working profile and has the function of locking the braking pressure of the two channels at the same time.

[0030] The brake pump 2 provides the brake system with a brake pressure proportional to the operating force. Two brake pumps 2 are installed on each machine. The upper part is the bleed nozzle assembly 45 and the oil storage chamber, and is provided with an observation window 46 to observe the oil storage situation in the oil storage chamber. The lower part has an external output oil circuit and a double-ear mounting hole. The driver applies force to the piston rod 47 through the foot pedal, so that the piston rod 47 moves downward and compresses the oil, which will provide the vehicle braking system with a brake pressure proportional to the operating pedal force to achieve the braking function. When the operating force is released, the brake pressure disappears.

[0031] The left and right multi-friction plate wet brakes 5 are respectively installed in the left and right rear axle housings 9 and arranged on the left and right planetary mechanism input transmission shafts 33 and 34. The multi-friction plate wet brakes 5 are composed of two pairs of symmetrically arranged pistons 35, brake discs 36, friction disc assemblies 37, return assemblies 38 and other parts. The hydraulic pressure acts on the pistons 35, so that the friction disc assemblies 37 are clamped between the brake discs 36 and the pistons 35 to achieve the braking function.

[0032] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0033] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A structure of a hydraulic brake system, characterized in that: The invention comprises a support assembly (1), an adjustment mechanism (3), a brake switch (4), a multi-friction plate wet brake (5), a hand brake lever assembly (6), an accumulator (7), and two brake pumps (2). The two brake pumps (2) are fixed to the support assembly (1) by bolts; four bolts are passed through the elliptical holes of the support assembly (1) and are vertically fixed to the driving floor (40); the adjustment mechanism (3) can move forward and backward on the support assembly (1); when the pedal (8) on the support assembly (1) moves, the piston in the brake pump (2) squeezes the brake oil in the pipeline through the brake switch (4) and flows to the left and right two multi-friction plate wet brakes (5) arranged on the input transmission shaft of the planetary mechanism in the rear axle housing (9); a first hose (10) and a first hard conduit (11) are connected between the brake pump and the brake switch; and a second hose (12) and a second hard conduit (13) are connected between the brake switch (4) and the wet brake (5).

2. The structure of a hydraulic brake system according to claim 1, characterized in that: The brake switch (4) adopts a dual-circuit brake switch, and its two oil inlets are connected to the oil circuit and connected to the accumulator (7) through the oil pipe (39). When the brake system pressure is abnormal, hydraulic oil is supplemented to ensure effective brake pressure.

3. The structure of a hydraulic brake system according to claim 1, characterized in that: The handbrake lever assembly (6) is connected to the brake switch (4) via a steel cable (14), and the handbrake is returned via a return spring (15).

4. The structure of a hydraulic brake system according to claim 1, characterized in that: The parking brake operation comprises a handle assembly (48), an outer cylinder (49), a screw (50), a spring (51), a screw plug (52), and a steel cable (14). The outer cylinder (49) is installed on the driving floor (40). The handle assembly (48) is inside the outer cylinder (49) and is connected to the support arm (32) of the brake switch (4) through a steel cable (14) with a slide rod end. The handle assembly (48) is pushed down to release the brake; the handle assembly (48) is lifted up to apply the brake, and then turned right 90 degrees to lock it, and then the brake pedal is stepped on to realize the parking stop function. When releasing the parking brake, it is only necessary to release the handle assembly (48) and the return spring (15) will pull the support arm (32) back to the original position.

5. The structure of a hydraulic brake system according to claim 1, characterized in that: The adjustment mechanism comprises a rotating handle bolt (16) and a rocker arm (17) mounted on a handle threaded shaft, and swings in a circle with a positioning shaft (18) as the axis, and realizes the front and rear movement of the support assembly (1) through a pin shaft 1 (19), a connecting rod (20) and a pin shaft 2 (21); the user can adjust the front and rear position of the support assembly (1) on which the foot pedal (8) is mounted according to different physical needs, so as to achieve a comfortable operating state and reduce driving fatigue.

6. The structure of a hydraulic brake system according to claim 1, characterized in that: The dual-way brake switch is composed of two two-position two-way valve type switches with completely identical structures, including a housing (22), a push rod (23), a valve seat (26), a first spring (25), a second spring (27), a valve assembly (28), a guide sleeve (24), a fixing plate (29), a cam mechanism (30), an end cover assembly (31), and a support arm (32); the dual-way brake switch connects or disconnects the hydraulic oil circuit between the brake pump and the brake, and can maintain the hydraulic pressure of the two-way brake system pipelines to maintain the required brake pressure.

7. The structure of a hydraulic brake system according to claim 6, characterized in that: The cam mechanism (30) can make the double chambers work synchronously. When the cam mechanism (30) is operated to rotate 90 degrees along the opening direction, the valve can be moved from the locked position to the open position. When the valve is locked, it is equivalent to a one-way valve. At this time, the working hydraulic oil can only reach the brake (5) through the valve, but cannot flow back. Therefore, it can maintain the pressure of the brake and realize the parking brake function. When the valve is in the other position, that is, the valve is opened, the dual-way brake switch is equivalent to two channels. The cam mechanism (30) is centered by the fixed plate (29). Its working surface contacts the push rod (23) and is connected to the housing (22) by the end cover assembly (31) through two M4 screws and fixed between the housing (22) and the end cover assembly (31), with a 90° rotation working angle; by operating the support arm (32) and the cam mechanism (30), the push rod (23) will move up and down to open or close the valve assembly (28), and its two chambers work synchronously. The cam mechanism (30) has a symmetrical working profile and has the function of locking the braking pressure of the two channels at the same time.

8. The structure of a hydraulic brake system according to claim 1, characterized in that: A brake pressure proportional to the operating force is provided to the brake system through a brake pump (2). Two brake pumps (2) are installed in each machine. The upper part is a bleed nozzle assembly (45) and an oil storage chamber, and is provided with an observation window (46) for observing the oil storage condition of the oil storage chamber. The lower part is provided with an external output oil circuit and a double-ear mounting hole. The driver applies force to the piston rod (47) through a foot pedal to move the piston rod (47) downward, compressing the oil, thereby providing the vehicle braking system with a brake pressure proportional to the operating pedal force, thereby realizing the braking function. When the operating force is released, the brake pressure disappears.

9. The structure of a hydraulic brake system according to claim 1, characterized in that: The left and right multi-friction plate wet brakes are respectively installed in the left and right rear axle housings (9) and arranged on the left and right planetary mechanism input transmission shafts (33) and (34). The multi-friction plate wet brake (5) is composed of two pairs of symmetrically arranged pistons (35), a brake disc (36), a friction disc assembly (37), and a return assembly (38). The hydraulic pressure acts on the piston (35), so that the friction disc assembly (37) is clamped between the brake disc (36) and the piston (35), thereby realizing the braking function.

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