Brake circulation system for loading machine

Abstract

The utility model discloses a brake circulation system for a loading machine, and belongs to the technical field of engineering machinery. The defects that in the prior art, a traditional brake system is poor in brake effect and even fails due to the fact that brake fluid in a pipeline is lacked are overcome. The main body structure of the hydraulic control system comprises a power assembly used for conveying gas or oil, a brake caliper assembly used for braking a front axle and a rear axle and a hydraulic control reversing assembly used for braking or releasing braking of the brake caliper assembly, a P port of the hydraulic control reversing assembly is connected with a high-pressure oil port of the power assembly, and an A port of the hydraulic control reversing assembly is connected with an oil inlet of the brake caliper assembly. The port B is connected with an oil outlet of the brake caliper assembly, and the port T is connected with an oil tank. The utility model is mainly applied to engineering machinery such as loaders and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of engineering machinery, and in particular relates to a brake circulation system for a loader. Background Art

[0002] Among the existing loader braking systems, air-over-oil dry-axle brakes have the lowest cost and are the most widely used, but their reliability is currently unstable. This is because when braking, a large amount of heat is generated when the brake caliper and the brake disc rub against each other, causing the brake oil to boil or even vaporize. When the pedal is released, the brake fluid spurts out from the vent of the booster pump oil cup, and the brake fluid in the pipeline is lacking, resulting in poor braking effect or even failure, which is extremely dangerous.

[0003] Therefore, in the prior art, a forward check valve is added behind the booster pump, and a pneumatic or electrically controlled reversing valve is installed behind the brake caliper. When the pedal is pressed on the pedal valve, the reversing valve is closed to brake; when the pedal is released, the reversing valve discharges high-pressure and high-temperature oil once to complete a cycle. Therefore, the use of pneumatically controlled reversing valves has problems such as inaccurate air pressure control and poor brake follow-up when the brake is released. When an electrically controlled reversing valve is used, the control is complex and requires the pressure of the air pressure sensor to be converted into current and then reversely controlled to control the on-off of the proportional valve. Especially for coal safety conditions, the solenoid valve and sensor must also meet coal safety certification requirements, which is more expensive and has a higher failure rate.

[0004] For example, the Chinese utility model patent application number 201820140901.4 discloses a loader braking system. Although the system uses a larger brake oil tank 6 so that the low-temperature oil in the brake oil tank 6 is mixed with the high-pressure and high-temperature brake fluid to reduce the oil temperature, a part of the low-temperature brake fluid will flow back to the oil cavity in the middle part of the booster pump 8, so that this brake circuit system can reduce the temperature of the brake fluid, thereby avoiding the brake fluid temperature being at a high temperature and unable to be released. However, the output air pressure of the pedal valve is used to control the opening and closing of the reversing valve, thereby controlling the dynamic pressure. Since the output air brake pressure range of the air brake pedal is approximately (0-1) MPa, the valve volume is large and the control accuracy is low. Utility Model Content

[0005] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a brake circulation system for a loader.

[0006] In order to achieve the above purpose, the utility model is implemented by adopting the following technical solutions:

[0007] A brake circulation system for a loader includes a power assembly for gas or oil delivery, a brake caliper assembly for front and rear axle braking, and a hydraulically controlled reversing assembly for braking or releasing the brake caliper assembly, wherein the P port of the hydraulically controlled reversing assembly is connected to the high-pressure oil port of the power assembly, the A port is connected to the oil inlet of the brake caliper assembly, the B port is connected to the oil outlet of the brake caliper assembly, and the T port is connected to the oil tank.

[0008] Preferably, a filter is provided between the T-port of the hydraulically controlled reversing assembly and the oil tank.

[0009] Preferably, the hydraulically controlled reversing assembly comprises a one-way valve and a switch valve, and the oil inlet of the one-way valve is connected to the hydraulic control port of the switch valve.

[0010] Preferably, the power assembly includes an air tank, an air brake valve and a booster pump, the air brake valve is connected to the air tank and the booster pump respectively, the P port of the one-way valve is connected to the high-pressure oil port of the booster pump, the A port of the one-way valve is connected to the oil inlet of the brake caliper assembly, the B port of the switch valve is connected to the oil outlet of the brake caliper assembly, and the T port of the switch valve is connected to the oil tank.

[0011] Preferably, the hydraulically controlled reversing assembly and the booster pump are each provided at one location.

[0012] Preferably, the hydraulically controlled reversing assembly and the booster pump are each provided at two locations.

[0013] Preferably, the power assembly includes a hydraulic pedal valve and an oil source, the oil suction port of the oil source is connected to the oil tank, the oil outlet is respectively connected to the P1 port and P2 port of the hydraulic pedal valve, the A1 port and A2 port of the hydraulic pedal valve are both connected to the P port of the one-way valve, the T1 port and T2 port of the hydraulic pedal valve are both connected to the oil tank, the A port of the one-way valve is connected to the oil inlet of the brake caliper assembly, the B port of the switch valve is connected to the oil outlet of the brake caliper assembly, and the T port of the switch valve is connected to the oil tank.

[0014] Preferably, the hydraulically controlled reversing assembly and the hydraulic pedal valve are each provided in one place.

[0015] Preferably, the hydraulically controlled reversing components are provided at two locations, and the hydraulic pedal valve is provided at one location.

[0016] Preferably, the hydraulically controlled reversing component is a hydraulically controlled reversing valve.

[0017] Preferably, the power assembly includes an air tank, an air brake valve and a booster pump, the air brake valve is connected to the air inlets of the air tank and the booster pump respectively, the P port of the hydraulically controlled reversing valve is connected to the high-pressure oil port of the booster pump, the A port is connected to the oil inlet of the brake caliper assembly, the B port is connected to the oil outlet of the brake caliper assembly, and the T port is connected to the oil tank.

[0018] Preferably, the hydraulically controlled reversing valve and the booster pump are each provided at one location.

[0019] Preferably, the hydraulically controlled reversing valve and the booster pump are each provided at two locations.

[0020] Preferably, the power assembly includes a hydraulic pedal valve and an oil source, the oil suction port of the oil source is connected to the oil tank, the oil outlet is respectively connected to the P1 port and P2 port of the hydraulic pedal valve, the A1 port and A2 port of the hydraulic pedal valve are both connected to the P port of the hydraulically controlled reversing valve, the T1 port and T2 port of the hydraulic pedal valve are both connected to the oil tank, the A port of the hydraulically controlled reversing valve is connected to the oil inlet of the brake caliper assembly, the B port of the hydraulically controlled reversing valve is connected to the oil outlet of the brake caliper assembly, and the T port of the hydraulically controlled reversing valve is connected to the oil tank.

[0021] Preferably, the hydraulically controlled reversing valve and the hydraulic pedal valve are each provided at one location.

[0022] Preferably, the hydraulically controlled reversing valve is provided at two locations, and the hydraulic pedal valve is provided at one location.

[0023] Compared with the prior art, the beneficial effects of the utility model are:

[0024] 1. In embodiments 8-13, a hydraulically controlled reversing valve is applied to the brake circulation system. When the pedal is stepped on, the oil of the brake caliper is disconnected from the return oil circuit. When the pedal is released, the brake caliper oil proportionally reduces the pressure to release the brake pressure. The hydraulically controlled reversing valve has a simple system, reliable control and low cost.

[0025] 2. In embodiments 3, 4, 9, and 10 of the present invention, the hydraulically controlled reversing valve is used in the air brake system; in embodiments 6, 7, 12, and 13, hydraulic oil is used to achieve braking and is used for the circulation of the full hydraulic brake system;

[0026] 3. The brake system adopts a hydraulically controlled reversing valve, which has good brake release followability and circulates and cools the brake fluid, effectively reducing the brake fluid temperature and improving the safety performance of braking;

[0027] 4. The one-way valve and the switch valve are combined into a hydraulically controlled reversing component, which has the same functions and effects as the hydraulically controlled reversing valve, and the purchase cost of the one-way valve and the switch valve is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of Example 3 of the present utility model;

[0029] Figure 2 This is a schematic diagram of Example 4 of the present utility model;

[0030] Figure 3 This is a schematic diagram of Example 6 of the present utility model;

[0031] Figure 4 This is a schematic diagram of Example 7 of the present utility model;

[0032] Figure 5 This is a schematic diagram of Example 9 of the present utility model;

[0033] Figure 6 This is a schematic diagram of Example 10 of the present utility model;

[0034] Figure 7 This is a schematic diagram of Example 12 of the present utility model;

[0035] Figure 8 This is a schematic diagram of Example 13 of the present utility model;

[0036] Fig. 9 This is a structural schematic diagram of the hydraulically controlled reversing valve in the utility model;

[0037] Fig.10 It is a schematic diagram of the followability of the pressures at the P and B ports when the pedal is released in the utility model.

[0038] In the figure: 1. Air storage tank; 2. Air brake valve; 3. Booster pump; 4. Hydraulic control reversing assembly; 41. Check valve; 42. Switch valve; 43. Hydraulic control reversing valve; 5. Brake caliper assembly; 6. Oil tank; 7. Filter; 8. Hydraulic pedal valve; 9. Oil source; 11. Spring 1; 12. Check valve spool; 14. Valve spool; 15. Spring 2. DETAILED DESCRIPTION

[0039] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.

[0040] Embodiment 1:

[0041] A brake circulation system for a loader includes a power assembly for gas or oil delivery, a brake caliper assembly 5 for front and rear axle braking, and a hydraulically controlled reversing assembly 4 for braking or releasing the brake caliper assembly 5, wherein the P port of the hydraulically controlled reversing assembly 4 is connected to the high-pressure oil port of the power assembly, the A port is connected to the oil inlet of the brake caliper assembly 5, the B port is connected to the oil outlet of the brake caliper assembly 5, and the T port is connected to the oil tank 6; a filter 7 is provided between the T port of the hydraulically controlled reversing assembly 4 and the oil tank 6, and the filter 7 can prevent the system from being blocked.

[0042] Embodiment 2:

[0043] like Figure 1 As shown, a brake circulation system for a loader is different from Example 1 in that the hydraulically controlled reversing component 4 includes a one-way valve 41 and a switch valve 42 , and the oil inlet of the one-way valve 41 is connected to the hydraulic control port of the switch valve 42 .

[0044] Embodiment 3:

[0045] For example Figure 1 As shown, a brake circulation system for a loader is different from Example 2 in that the power assembly includes an air tank 1, an air brake valve 2 and a booster pump 3, the air brake valve 2 is respectively connected to the air inlet of the booster pump 3 and the air tank 1, the P port of the one-way valve 41 is connected to the high-pressure oil port of the booster pump 3, the A port of the one-way valve 41 is connected to the oil inlet of the brake caliper assembly 5, the B port of the switch valve 42 is connected to the oil outlet of the brake caliper assembly 5, and the T port of the switch valve 42 is connected to the oil tank 6.

[0046] Furthermore, the hydraulically controlled reversing assembly 4 and the booster pump 3 are both provided with two locations, such as Figure 1 As shown, one booster pump 3 is connected to one hydraulically controlled reversing assembly 4, one hydraulically controlled reversing assembly 4 is connected to the front axle brake caliper, and the other hydraulically controlled reversing assembly 4 is connected to the rear axle brake caliper.

[0047] Embodiment 4:

[0048] like Figure 2 As shown, a brake circulation system for a loader is different from Example 3 in that the hydraulically controlled reversing component 4 and the booster pump 3 are both provided in one place, that is, only one booster pump 3 is connected to only one hydraulically controlled reversing component 4, and the front axle brake caliper and the rear axle brake caliper are connected in parallel and then connected to one hydraulically controlled reversing component 4.

[0049] Embodiment 5:

[0050] like Figure 3 As shown, a brake circulation system for a loader is different from Example 2 in that the power assembly includes a hydraulic pedal valve 8 and an oil source 9, the oil suction port of the oil source 9 is connected to the oil tank 6, and the oil outlet is respectively connected to the P1 port and the P2 port of the hydraulic pedal valve 8, the A1 port and the A2 port of the hydraulic pedal valve 8 are both connected to the P port of the one-way valve 41, the T1 port and the T2 port of the hydraulic pedal valve 8 are both connected to the oil tank 6, the A port of the one-way valve 41 is connected to the oil inlet of the brake caliper assembly 5, the B port of the switch valve 42 is connected to the oil outlet of the brake caliper assembly 5, and the T port of the switch valve 42 is connected to the oil tank 6.

[0051] In this embodiment, the oil source 9 may be a hydraulic pump, or may be an oil source drawn from a working system.

[0052] Embodiment 6:

[0053] For example Figure 3 As shown, a brake circulation system for a loader is different from Example 5 in that the hydraulically controlled reversing component 4 is provided at two locations, and the hydraulic pedal valve 8 is provided at one location, that is, the A1 port of the hydraulic pedal valve 8 is connected to the P port of a one-way valve 41, and the A2 port of the hydraulic pedal valve 8 is connected to the P port of another one-way valve 41.

[0054] Embodiment 7:

[0055] like Figure 4 As shown, a brake circulation system for a loader is different from Example 6 in that the hydraulically controlled reversing component 4 and the hydraulic pedal valve 8 are both provided with one place, that is, the A1 port and the A2 port of the hydraulic pedal valve 8 are connected in parallel and then connected to the P port of the hydraulically controlled reversing component 4, and the front axle brake caliper and the rear axle brake caliper are connected in parallel and then connected to a hydraulically controlled reversing component 4.

[0056] Embodiment 8:

[0057] like Figure 5 As shown, a brake circulation system for a loader is different from Example 1 in that the hydraulically controlled reversing component 4 is a hydraulically controlled reversing valve 43.

[0058] The power assembly includes an air tank 1, an air brake valve 2 and a booster pump 3. The air brake valve 2 is connected to the air inlets of the air tank 1 and the booster pump 3 respectively. The P port of the hydraulically controlled reversing valve 43 is connected to the high-pressure oil port of the booster pump 3, the A port is connected to the oil inlet of the brake caliper assembly 5, the B port is connected to the oil outlet of the brake caliper assembly 5, and the T port is connected to the oil tank 6.

[0059] Embodiment 9:

[0060] For example Figure 5 As shown, a brake circulation system for a loader is different from Example 8 in that the hydraulically controlled reversing valve 43 and the booster pump 3 are both provided at two locations.

[0061] Embodiment 10:

[0062] like Figure 6 As shown, a brake circulation system for a loader is different from Example 9 in that the hydraulically controlled reversing valve 43 and the booster pump 3 are both provided in one place.

[0063] Embodiment 11:

[0064] like Figure 7 As shown, a brake circulation system for a loader, the power component includes a hydraulic pedal valve 8 and an oil source 9, the oil suction port of the oil source 9 is connected to the oil tank 6, the oil outlet is respectively connected to the P1 port and the P2 port of the hydraulic pedal valve 8, the A1 port and the A2 port of the hydraulic pedal valve 8 are both connected to the P port of the hydraulically controlled reversing valve 43, the T1 port and the T2 port of the hydraulic pedal valve 8 are both connected to the oil tank 6, the A port of the hydraulically controlled reversing valve 43 is connected to the oil inlet of the brake caliper assembly 5, the B port of the hydraulically controlled reversing valve 43 is connected to the oil outlet of the brake caliper assembly 5, and the T port of the hydraulically controlled reversing valve 43 is connected to the oil tank 6.

[0065] In this embodiment, the hydraulically controlled reversing valve 43 can realize that when the pedal is released, when the pressure of the P port decreases, the pressure of the B port also decreases proportionally, and at the same time, the oil in the A port and the B port will not return to the P port, so the brake followability of the hydraulically controlled reversing valve 43 is good. Fig.10 shown.

[0066] Embodiment 12:

[0067] For example Figure 7 As shown, a brake circulation system for a loader, the hydraulically controlled reversing valve 43 is provided at two locations, and the hydraulic pedal valve 8 is provided at one location.

[0068] Embodiment 13:

[0069] like Figure 8 As shown, a brake circulation system for a loader, the hydraulically controlled reversing valve 43 and the hydraulic pedal valve 8 are both provided in one place.

[0070] Herein, the working principle is described by taking Example 9 as an example:

[0071] After the vehicle is started, the air tank 1 is filled with gas. When braking, the air brake valve 2 is switched, and the gas enters the booster pump 3 and begins to build pressure. The pressure is output to the hydraulic control reversing valve 43. When the pressure at the P port is about p1-p2 bar (such as 3-6 bar), the one-way valve composed of the spring 11 and the one-way valve core 12 is closed. The valve core 14 in the hydraulic control reversing valve 43 does not move. At this time, the P port to the A port is not connected, and the B port to the T port is open. When the pressure continues to rise and exceeds p2 bar, due to the large right side area of ​​the valve core 14, the valve core 14 overcomes the spring force of the spring 2 15 and moves to the left until the valve core 14 combines with the end face of the reversing valve body to form a cone seal, and the B port to the T port is cut off. Since the pressure at the P port is greater than p2 bar, the P port to the A port is connected, and the A port is connected to the inlet of the brake caliper. The oil enters the brake caliper. Since the B port to the T port is cut off, the brake system begins to build pressure and brakes.

[0072] When the brake pedal is released and a certain release angle is maintained, the pressure at the P port of the hydraulically controlled reversing valve 43 begins to decrease to a certain value, such as the pressure at the P port decreases from 120 bar to 100 bar. Fig. 9As shown, the pressure at the right side P port of the valve core 14 in the hydraulically controlled reversing valve 4 decreases, while the pressure at the left side B chamber remains unchanged. Under the action of the spring force of the spring 2 15 and the pressure of the B chamber, it is reset. When the spring force and the force of the B chamber are greater than the right chamber pressure at P, the B port to the T port begins to be connected, and the pressure at the B port begins to decrease, such as the pressure at the B port decreases from 120 bar to about 110 bar. When the force at the A port is greater than the spring force of the spring 2 15 and the force at the B chamber, the hydraulically controlled reversing valve 4 is reversed again, and the B port to the T port is cut off to achieve a certain brake pressure release. Since there is a one-way valve from the P port to the A port, the oil will not flow from the A port to the P port. At the same time, the A port and the B port are connected, and circulate through the B port to the T port.

[0073] When the brake pedal is completely released, the pressure at the P port of the hydraulically controlled reversing valve 43 is 0 bar, the pressure at the P port on the right side of the valve core 14 in the hydraulically controlled reversing valve 43 is 0 bar, and the pressure at the B port on the left side is reduced to 0 bar. Under the action of the spring force of the spring 15, the valve core 14 moves from the left side to the right side, and the B port to the T port begins to be connected, the pressure at the A chamber and the B chamber is reduced to 0 bar, and the brake is released. At the same time, the A port and the B port are connected, and the oil returns from the B port to the T port, and the oil circulates.

Claims

1. A brake circulation system for a loader, characterized in that: The invention comprises a power assembly for gas or oil delivery, a brake caliper assembly (5) for front and rear axle braking, and a hydraulically controlled reversing assembly (4) for braking or releasing the brake caliper assembly (5), wherein the P port of the hydraulically controlled reversing assembly (4) is connected to the high-pressure oil port of the power assembly, the A port is connected to the oil inlet of the brake caliper assembly (5), the B port is connected to the oil outlet of the brake caliper assembly (5), and the T port is connected to the oil tank (6).

2. The brake circulation system for a loader according to claim 1, characterized in that: The hydraulically controlled reversing component (4) comprises a one-way valve (41) and a switch valve (42), and the oil inlet of the one-way valve (41) is connected to the hydraulic control port of the switch valve (42).

3. The brake circulation system for a loader according to claim 2, characterized in that: The power assembly comprises an air storage tank (1), an air brake valve (2) and a booster pump (3); the air brake valve (2) is connected to the air storage tank (1) and the booster pump (3) respectively; the P port of the one-way valve (41) is connected to the high-pressure oil port of the booster pump (3); the A port of the one-way valve (41) is connected to the oil inlet of the brake caliper assembly (5); the B port of the switch valve (42) is connected to the oil outlet of the brake caliper assembly (5); and the T port of the switch valve (42) is connected to the oil tank (6).

4. The brake circulation system for a loader according to claim 3, characterized in that: The hydraulically controlled reversing component (4) and the booster pump (3) are each provided at one location or at two locations.

5. The brake circulation system for a loader according to claim 2, characterized in that: The power assembly comprises a hydraulic pedal valve (8) and an oil source (9); the oil suction port of the oil source (9) is connected to the oil tank (6); the oil outlet is respectively connected to the P1 port and the P2 port of the hydraulic pedal valve (8); the A1 port and the A2 port of the hydraulic pedal valve (8) are both connected to the P port of the one-way valve (41); the T1 port and the T2 port of the hydraulic pedal valve (8) are both connected to the oil tank (6); the A port of the one-way valve (41) is connected to the oil inlet of the brake caliper assembly (5); the B port of the switch valve (42) is connected to the oil outlet of the brake caliper assembly (5); and the T port of the switch valve (42) is connected to the oil tank (6).

6. The brake circulation system for a loader according to claim 5, characterized in that: The hydraulically controlled reversing component (4) and the hydraulic pedal valve (8) are both provided at one location.

7. The brake circulation system for a loader according to claim 5, characterized in that: The hydraulically controlled reversing components (4) are provided at two locations, and the hydraulic pedal valve (8) is provided at one location.

8. The brake circulation system for a loader according to claim 1, characterized in that: The hydraulically controlled reversing component (4) is a hydraulically controlled reversing valve (43).

9. The brake circulation system for a loader according to claim 8, characterized in that: The power assembly comprises an air storage tank (1), an air brake valve (2) and a booster pump (3); the air brake valve (2) is connected to the air inlets of the air storage tank (1) and the booster pump (3) respectively; the P port of the hydraulically controlled reversing valve (43) is connected to the high-pressure oil port of the booster pump (3); the A port is connected to the oil inlet of the brake caliper assembly (5); the B port is connected to the oil outlet of the brake caliper assembly (5); and the T port is connected to the oil tank (6).

10. The brake circulation system for a loader according to claim 8, characterized in that: The power assembly comprises a hydraulic pedal valve (8) and an oil source (9); the oil suction port of the oil source (9) is connected to the oil tank (6); the oil outlet is respectively connected to the P1 port and the P2 port of the hydraulic pedal valve (8); the A1 port and the A2 port of the hydraulic pedal valve (8) are both connected to the P port of the hydraulically controlled reversing valve (43); the T1 port and the T2 port of the hydraulic pedal valve (8) are both connected to the oil tank (6); the A port of the hydraulically controlled reversing valve (43) is connected to the oil inlet of the brake caliper assembly (5); the B port of the hydraulically controlled reversing valve (43) is connected to the oil outlet of the brake caliper assembly (5); and the T port of the hydraulically controlled reversing valve (43) is connected to the oil tank (6).

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