Hydraulic brake system for a working machine and working machine

Abstract

The utility model relates to a kind of hydraulic braking system for engineering machinery, including hydraulic pump, brake liquid filling valve, front axle running brake, rear axle running brake, brake foot valve and hydraulic oil tank, brake liquid filling valve includes pressure oil port and first oil outlet;The input port of hydraulic pump is fluidly connected with the hydraulic oil tank, and the output port of hydraulic pump is fluidly connected with the pressure oil port of brake liquid filling valve;First oil outlet is fluidly connected with front axle running brake and rear axle running brake respectively via brake foot valve;Hydraulic braking system further includes energy accumulator and brake direction control valve, energy accumulator is fluidly connected with first oil outlet, brake direction control valve is arranged between brake liquid filling valve and brake foot valve and has first position, when being in first position, hydraulic fluid from energy accumulator and first oil outlet can be supplied to front axle running brake and rear axle running brake via brake direction control valve and brake foot valve.The utility model further relates to a kind of engineering machinery.

Description

Technical Field

[0001] This utility model relates to the field of engineering machinery, and more specifically to a hydraulic braking system for engineering machinery and an engineering machinery including the hydraulic braking system. Background Technology

[0002] Traditional hydraulic braking systems in construction machinery are typically dual-circuit systems. A single pump serves as the hydraulic oil source, simultaneously filling two brake accumulators via a brake filling valve. The fluid is then supplied to the front and rear axle service brakes via a brake pedal valve, thus achieving vehicle braking. The front and rear axles have two separate circuits, making the hydraulic system complex and costly.

[0003] The present invention aims to solve at least one of the above-mentioned problems in the prior art, as well as other problems. Utility Model Content

[0004] According to one aspect of this utility model, a hydraulic braking system for engineering machinery is provided, comprising a hydraulic pump, a brake filling valve, a front axle service brake, a rear axle service brake, a brake pedal valve, and a hydraulic oil tank, wherein:

[0005] The brake fluid filling valve includes a pressure port and a first outlet port;

[0006] The inlet of the hydraulic pump is fluidly connected to the hydraulic oil tank, and the outlet of the hydraulic pump is fluidly connected to the pressure oil port of the brake filling valve.

[0007] The first outlet of the brake filling valve is fluidly connected to the front axle service brake and the rear axle service brake via the brake foot valve.

[0008] The hydraulic braking system is characterized in that it further includes an accumulator and a braking direction control valve, wherein:

[0009] The accumulator is fluidly connected to the first outlet of the brake fluid charging valve.

[0010] The brake direction control valve is located between the brake filling valve and the brake foot valve and has a first position. When the brake direction control valve is in the first position, hydraulic fluid from the accumulator and the first outlet of the brake filling valve can be supplied to the front axle service brake and the rear axle service brake via the brake direction control valve and the brake foot valve.

[0011] Advantageously, the brake direction control valve also has a second position and a third position, wherein:

[0012] When the brake direction control valve is in the second position, hydraulic fluid from the accumulator and the first outlet of the brake charging valve can be supplied to the front axle service brake only through the brake direction control valve and the brake pedal valve.

[0013] When the brake direction control valve is in the third position, hydraulic fluid from the accumulator and the first outlet of the brake charging valve can be supplied to the rear axle service brake only through the brake direction control valve and the brake foot valve.

[0014] Advantageously, the brake direction control valve is provided with a first branch and a second branch, wherein:

[0015] When the brake direction control valve is in the first position, hydraulic fluid from the accumulator and the first outlet of the brake charging valve can be supplied to the front axle service brake and the rear axle service brake via the first branch and the second branch, respectively.

[0016] When the brake direction control valve is in the second position, hydraulic fluid from the first outlet of the accumulator and the brake filling valve can be supplied to the front axle service brake via the first branch, while the second branch is cut off.

[0017] When the brake direction control valve is in the third position, hydraulic fluid from the accumulator and the first outlet of the brake charging valve can be supplied to the rear axle service brake via the second branch, and the first branch is cut off.

[0018] Advantageously, when a fault occurs in the hydraulic circuit leading to the front axle service brake, the brake direction control valve switches to its third position; when a fault occurs in the hydraulic circuit leading to the rear axle service brake, the brake direction control valve switches to its second position.

[0019] Advantageously, the hydraulic braking system also includes a parking brake, and the brake fluid filling valve further includes a check valve, a filling pressure control valve, a parking brake valve, a safety relief valve, and a second outlet, wherein:

[0020] The second outlet of the brake fluid filling valve is fluidly connected to the parking brake.

[0021] The pressure port of the brake filling valve is fluidly connected to the first and second outlet ports of the brake filling valve via a check valve.

[0022] The filling pressure control valve is located between the oil inlet of the check valve and the oil return port of the brake filling valve.

[0023] The parking brake valve is located between the oil outlet of the one-way valve and the second oil outlet of the brake filling valve;

[0024] The safety relief valve is located between the pressure port and the return port of the brake filling valve.

[0025] Advantageously, the parking brake valve is a solenoid valve. When the parking brake valve is energized, hydraulic fluid at the outlet of the one-way valve can be supplied to the parking brake via the parking brake valve to release the parking brake. When the parking brake valve is de-energized, the hydraulic fluid in the parking brake is released to achieve parking braking.

[0026] Advantageously, when the pressure at the outlet of the one-way valve is greater than a preset first threshold, the filling pressure control valve switches from a position where its inlet and outlet are fluidly disconnected to a position where its inlet and outlet are fluidly connected.

[0027] Advantageously, when the pressure at the pressure port of the brake filling valve is greater than a preset second threshold, the safety relief valve switches from a position where its inlet and outlet are fluid disconnected to a position where its inlet and outlet are fluid connected.

[0028] According to another aspect of the present invention, an engineering machine is provided, wherein the engineering machine includes a hydraulic braking system according to the present invention.

[0029] The hydraulic braking system of this invention only has one accumulator, which supplies oil to the front and rear axle service brakes via a brake direction control valve. Furthermore, even if one brake circuit fails, the other brake circuit can still achieve full vehicle braking. This design simplifies the hydraulic braking system, reduces overall machine cost, and improves the operational safety of construction machinery. Attached Figure Description

[0030] The present invention will now be described in more detail with reference to the illustrative accompanying drawings. The drawings and corresponding embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Wherein:

[0031] Figure 1 A schematic diagram of the hydraulic braking system for engineering machinery according to a preferred embodiment of the present invention is shown.

[0032] List of reference numerals in the attached diagram:

[0033] 1. Hydraulic pump 2. Brake filling valve

[0034] 3 Parking brake 4 Front axle service brake

[0035] 5. Rear axle service brake; 6. Brake foot valve

[0036] 7. Hydraulic oil tank 8. Accumulator

[0037] 9 Brake Direction Control Valve 10 Check Valve

[0038] 11 Filling pressure control valve 12 Parking brake valve

[0039] 13 Safety relief valve 100 Hydraulic braking system

[0040] P Pressure port A1 First outlet

[0041] A2 Second oil outlet T Return port Detailed Implementation

[0042] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to enable those skilled in the art to more fully understand and implement the present invention. However, it will be apparent to those skilled in the art that implementations of the present invention may not include some of these specific details. Furthermore, it should be understood that the present invention is not limited to the specific embodiments described. Rather, the present invention can be conceived to be implemented with any combination of the features and elements described below, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are for illustrative purposes only and should not be construed as elements or limitations of the claims unless expressly set forth in the claims.

[0043] Figure 1 The schematic diagram illustrates the hydraulic principle of a hydraulic braking system 100 for engineering machinery or other types of machinery according to a preferred embodiment of the present invention.

[0044] like Figure 1 As shown, the hydraulic braking system 100 includes a hydraulic pump 1, a brake filling valve 2, a parking brake 3, a front axle service brake 4, a rear axle service brake 5, a brake foot valve 6, and a hydraulic oil tank 7.

[0045] The inlet of hydraulic pump 1 is fluidly connected to hydraulic oil tank 7, and the outlet of hydraulic pump 1 is fluidly connected to the pressure port P (or inlet) of brake filling valve 2. The first outlet A1 of brake filling valve 2 is fluidly connected to the front axle service brake 4 and the rear axle service brake 5 via brake pedal valve 6. The second outlet A2 of brake filling valve 2 is fluidly connected to parking brake 3.

[0046] According to this utility model, the hydraulic braking system 100 further includes an accumulator 8 and a brake direction control valve 9. The accumulator 8 is fluidly connected to the first oil outlet A1 of the brake filling valve 2. The brake direction control valve 9 is disposed between the brake filling valve 2 and the brake pedal valve 6.

[0047] exist Figure 1 In the embodiment shown, the brake direction control valve 9 has a first position ( Figure 1 The middle position shown), the second position ( Figure 1 (shown as left position) and third position ( Figure 1(As shown in the right position). When the brake direction control valve 9 is in the first position, hydraulic fluid from the accumulator 8 and the first outlet A1 of the brake filling valve 2 can be supplied to the front axle service brake 4 and the rear axle service brake 5 via the brake direction control valve 9 and the brake pedal valve 6. When the brake direction control valve 9 is in the second position, hydraulic fluid from the accumulator 8 and the first outlet A1 of the brake filling valve 2 can be supplied to the front axle service brake 4 only via the brake direction control valve 9 and the brake pedal valve 6. When the brake direction control valve 9 is in the third position, hydraulic fluid from the accumulator 8 and the first outlet A1 of the brake filling valve 2 can be supplied to the rear axle service brake 5 only via the brake direction control valve 9 and the brake pedal valve 6.

[0048] Advantageously, such as Figure 1 As shown, the brake direction control valve 9 is configured as a three-position three-way valve, which includes a first branch and a second branch. The first branch is used to connect the accumulator 8 and the first outlet A1 of the brake fluid filling valve 2 to the front axle service brake 4. The second branch is used to connect the accumulator 8 and the first outlet A1 of the brake fluid filling valve 2 to the rear axle service brake 5.

[0049] When the brake direction control valve 9 is in the first position, the first branch and the second branch are fluidly connected. Therefore, the hydraulic fluid from the accumulator 8 and the first oil outlet A1 of the brake filling valve 2 can be supplied to the front axle service brake 4 and the rear axle service brake 5 via the first branch and the second branch, respectively.

[0050] When the brake direction control valve 9 is in the second position, the first branch is fluid connected and the second branch is cut off. Therefore, the hydraulic fluid from the accumulator 8 and the first outlet A1 of the brake filling valve 2 can be supplied to the front axle service brake 4 via the first branch.

[0051] When the brake direction control valve 9 is in the third position, the first branch is cut off and the second branch is fluid connected. Therefore, the hydraulic fluid from the accumulator 8 and the first outlet A1 of the brake filling valve 2 can be supplied to the rear axle service brake 5 via the second branch.

[0052] When the hydraulic braking system 100 is operating normally (without malfunction), the brake direction control valve 9 is in the first position ( Figure 1 (in the middle position), hydraulic fluid can be supplied to the front axle service brake 4 and the rear axle service brake 5 simultaneously through the first branch and the second branch to achieve vehicle braking.

[0053] When a fault occurs in the oil circuit leading to the front axle service brake 4 (e.g., an oil leak), the pressure in the first branch of the brake direction control valve 9 decreases, and pressure feedback from the second branch is sent to the right side of the brake direction control valve 9, pushing the valve core of the brake direction control valve 9 to move to the left, causing the valve to switch to its third position. Figure 1 (Right position), at this time the first branch is cut off, and the hydraulic fluid can be supplied to the rear axle service brake 5 through the second branch to achieve normal braking of the whole vehicle.

[0054] When a fault occurs in the oil circuit leading to the rear axle service brake 5 (e.g., an oil leak), the pressure in the second branch of the brake direction control valve 9 decreases, and pressure feedback from the first branch is sent to the left side of the brake direction control valve 9, pushing the valve core of the brake direction control valve 9 to move to the right, causing the valve to switch to its second position. Figure 1 (Left position), at this time the second branch is cut off, and the hydraulic fluid can be supplied to the front axle service brake 4 through the first branch to achieve normal braking of the whole vehicle.

[0055] Advantageously, the brake filling valve 2 includes a one-way valve 10, a filling pressure control valve 11, a parking brake valve 12, and a safety relief valve 13.

[0056] The pressure port P of the brake filling valve 2 is fluidly connected to the first outlet A1 and the second outlet A2 of the brake filling valve 2 via a check valve 10. The check valve 10 ensures that the hydraulic fluid can only flow from the pressure port P toward the first outlet A1 and the second outlet A2, and cannot flow in the opposite direction.

[0057] The filling pressure control valve 11 is located between the oil inlet of the check valve 10 and the oil return port T of the brake filling valve 2. The oil return port T is fluidly connected to the hydraulic oil tank 7.

[0058] The filling pressure control valve 11 is used to set the filling pressure of the accumulator 8. For example... Figure 1 As shown, when it is necessary to charge the accumulator 8, the charging pressure control valve 11 is in the position where the fluid flow between its inlet and outlet is disconnected. When the pressure at the outlet of the check valve 10 is greater than a preset first threshold, the charging pressure control valve 11 is in the position where the fluid flow between its inlet and outlet is disconnected (e.g., ...). Figure 1 When the valve is switched to the position where its inlet and outlet are in fluid communication (not shown), the hydraulic fluid from the pressure port P of the brake charging valve 2 returns to the hydraulic oil tank 7 through the charging pressure control valve 11, and stops charging the accumulator 8.

[0059] The parking brake valve 12 is located between the oil outlet of the one-way valve 10 and the second oil outlet A2 of the brake filling valve 2.

[0060] Advantageously, the parking brake 3 is a hydraulically released type, meaning that the brake can be released when hydraulic fluid is supplied to the release chamber of the parking brake 3, and braking can be achieved when the hydraulic fluid in the release chamber of the parking brake 3 is released. The parking brake valve 12 is advantageously a solenoid valve. When the parking brake valve 12 is energized, hydraulic fluid at the outlet of the one-way valve 10 can be supplied to the parking brake 3 via the parking brake valve 12 to release the parking brake; when the parking brake valve 12 is de-energized, the hydraulic fluid in the parking brake 3 is released to the hydraulic oil tank 7 via the parking brake valve 12 to achieve parking braking.

[0061] The energization and de-energization of the parking brake valve 12 can be advantageously controlled by a switch. The switch can be installed, for example, in the cab of the construction machinery.

[0062] Safety relief valve 13 is located between the pressure port P and the return port T of brake fluid filling valve 2. Safety relief valve 13 is used to limit the maximum pressure at pressure port P, protecting system components. When the pressure at pressure port P exceeds a preset second threshold, safety relief valve 13 disconnects fluid from its inlet and outlet ports (e.g., ...). Figure 1 (as shown) Switch to the position where its inlet and outlet are in fluid communication (not shown).

[0063] The hydraulic braking system 100 of this invention only has one accumulator 8, which supplies oil to the front and rear axle service brakes via a brake direction control valve 9. Furthermore, if one brake circuit fails, the other brake circuit can still achieve vehicle braking. This design simplifies the hydraulic braking system, reduces overall machine cost, and improves the operational safety of construction machinery.

[0064] Industrial applicability

[0065] The working principle of the hydraulic braking system 100 according to this utility model is explained in detail below.

[0066] When it is necessary to release the parking brake, the operator energizes the parking brake valve 12 by switching on the switch, supplying hydraulic fluid to the parking brake 3 to release the parking brake.

[0067] When the hydraulic braking system 100 is operating normally (without malfunction), the brake direction control valve 9 is in the first position ( Figure 1 (In the middle position). When the operator actuates the brake foot valve 6, hydraulic fluid can be supplied simultaneously to the front axle service brake 4 and the rear axle service brake 5 through the first branch and the second branch to achieve vehicle braking.

[0068] When a fault occurs in the hydraulic circuit leading to the front axle service brake 4 (e.g., a leak), the brake direction control valve 9 switches to its third position. Figure 1(Right position), at which point the first branch is cut off. When the operator actuates the brake foot valve 6, hydraulic fluid can be supplied to the rear axle service brake 5 through the second branch, achieving normal braking of the entire vehicle.

[0069] When a fault occurs in the hydraulic line leading to the rear axle service brake 5 (e.g., a leak), the brake direction control valve 9 switches to its second position. Figure 1 (Left position), at which point the second branch is cut off. When the operator actuates the brake foot valve 6, hydraulic fluid can be supplied to the front axle service brake 4 through the first branch, achieving normal braking of the entire vehicle.

[0070] The hydraulic braking system of this utility model has been described above with reference to specific embodiments. It will be apparent to those skilled in the art that various changes and modifications can be made to the hydraulic braking system of this utility model without departing from the design principles of this utility model. For example, embodiments of this utility model may not include some of the features described, and this utility model is not limited to the described specific embodiments, but any combination of the described features and elements is conceivable. Other embodiments will be apparent to those skilled in the art in light of consideration of the specification and practice with the disclosed hydraulic braking system. The specification and examples are to be considered exemplary only, and the true scope is indicated by the appended claims and their equivalents.

Claims

1. A hydraulic braking system for engineering machinery, comprising a hydraulic pump (1), a brake filling valve (2), a front axle service brake (4), a rear axle service brake (5), a brake pedal valve (6), and a hydraulic oil tank (7), wherein: The brake filling valve (2) includes a pressure port (P) and a first outlet port (A1); The inlet of the hydraulic pump (1) is fluidly connected to the hydraulic oil tank (7), and the outlet of the hydraulic pump is fluidly connected to the pressure port (P) of the brake filling valve (2). The first outlet (A1) of the brake filling valve (2) is fluidly connected to the front axle service brake (4) and the rear axle service brake (5) via the brake foot valve (6); The hydraulic braking system (100) is characterized in that it further includes an accumulator (8) and a braking direction control valve (9), wherein: The accumulator (8) is fluidly connected to the first oil outlet (A1) of the brake fluid filling valve (2). The brake direction control valve (9) is located between the brake filling valve (2) and the brake foot valve (6) and has a first position. When the brake direction control valve (9) is in the first position, hydraulic fluid from the accumulator (8) and the first outlet (A1) of the brake filling valve (2) can be supplied to the front axle service brake (4) and the rear axle service brake (5) via the brake direction control valve (9) and the brake foot valve (6).

2. The hydraulic braking system according to claim 1, characterized in that, The brake direction control valve (9) also has a second position and a third position, wherein: When the brake direction control valve (9) is in the second position, hydraulic fluid from the first outlet (A1) of the accumulator (8) and the brake filling valve (2) can be supplied to the front axle service brake (4) only via the brake direction control valve (9) and the brake foot valve (6). When the brake direction control valve (9) is in the third position, hydraulic fluid from the first outlet (A1) of the accumulator (8) and the brake filling valve (2) can be supplied to the rear axle service brake (5) only via the brake direction control valve (9) and the brake foot valve (6).

3. The hydraulic braking system according to claim 2, characterized in that, The brake direction control valve (9) is provided with a first branch and a second branch, wherein: When the brake direction control valve (9) is in the first position, hydraulic fluid from the first outlet (A1) of the accumulator (8) and the brake filling valve (2) can be supplied to the front axle service brake (4) and the rear axle service brake (5) via the first branch and the second branch, respectively. When the brake direction control valve (9) is in the second position, hydraulic fluid from the first outlet (A1) of the accumulator (8) and the brake filling valve (2) can be supplied to the front axle service brake (4) via the first branch, and the second branch is cut off. When the brake direction control valve (9) is in the third position, hydraulic fluid from the first outlet (A1) of the accumulator (8) and the brake filling valve (2) can be supplied to the rear axle service brake (5) via the second branch, and the first branch is cut off.

4. The hydraulic braking system according to claim 2 or 3, characterized in that, When a fault occurs in the oil circuit leading to the front axle service brake (4), the brake direction control valve (9) switches to its third position; When a fault occurs in the oil circuit leading to the rear axle service brake (5), the brake direction control valve (9) switches to its second position.

5. The hydraulic braking system according to any one of claims 1 to 3, characterized in that, The hydraulic braking system also includes a parking brake (3), and the brake filling valve (2) further includes a check valve (10), a filling pressure control valve (11), a parking brake valve (12), a safety relief valve (13), and a second oil outlet (A2), wherein: The second outlet (A2) of the brake filling valve (2) is fluidly connected to the parking brake (3); The pressure port (P) of the brake filling valve (2) is fluidly connected to the first outlet (A1) and the second outlet (A2) of the brake filling valve (2) via a check valve (10); The filling pressure control valve (11) is located between the oil inlet of the check valve (10) and the oil return port (T) of the brake filling valve (2); The parking brake valve (12) is located between the oil outlet of the one-way valve (10) and the second oil outlet (A2) of the brake filling valve (2); The safety relief valve (13) is located between the pressure port (P) and return port (T) of the brake filling valve (2).

6. The hydraulic braking system according to claim 5, characterized in that, The parking brake valve (12) is a solenoid valve. When the parking brake valve (12) is energized, the hydraulic fluid at the outlet of the one-way valve (10) can be supplied to the parking brake (3) through the parking brake valve (12) to release the parking brake. When the parking brake valve (12) is de-energized, the hydraulic fluid in the parking brake (3) is released to realize the parking brake.

7. The hydraulic braking system according to claim 5, characterized in that, When the pressure at the outlet of the one-way valve (10) is greater than the preset first threshold, the filling pressure control valve (11) switches from the position where the fluid is disconnected between its inlet and outlet to the position where the fluid is connected between its inlet and outlet.

8. The hydraulic braking system according to claim 5, characterized in that, When the pressure at the pressure port (P) of the brake filling valve (2) is greater than the preset second threshold, the safety relief valve (13) switches from the position where its inlet and outlet are fluid disconnected to the position where its inlet and outlet are fluid connected.

9. An engineering machinery, characterized in that, The engineering machinery includes a hydraulic braking system according to any one of claims 1 to 8.

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