Hydraulic integrated valve block and hydraulic braking system comprising same

Abstract

The utility model provides an integrated valve block and a hydraulic brake system comprising the hydraulic integrated valve block, the hydraulic integrated valve block comprises a valve body, the valve body is provided with an oil inlet P0, an oil return port and a detection oil port M connected with a pressure sensor; an OPS electromagnetic valve is connected between the oil inlet P0 and the pilot oil port P1, an unloading valve is connected between the oil inlet P0 and the energy storage oil port P2, a logic valve is connected between the oil inlet P0 and the cooling oil port D, and the unloading valve is connected with the logic valve through an oil way. The oil inlet end of the brake oil port P3 is connected with the energy storage oil port P2 through a two-position three-way electromagnetic valve. Control oil ways of a service brake, a parking brake, a drive axle, an OPS function and the like are integrated into the integrated valve block and are respectively connected and controlled through oil ports. The hydraulic system is easy to install, compact in structure and convenient to install and maintain, and cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of forklifts, in particular to a hydraulic integrated valve block and a hydraulic brake system containing the hydraulic integrated valve block. Background Art

[0002] Heavy-duty forklifts' service and parking brakes are mostly hydraulically operated. To ensure reliable braking, the entire hydraulic system consists of two hydraulic circuits: service and parking brakes. Furthermore, the service brakes, mounted on the drive axle, generate heat due to prolonged friction between the friction pads during braking, requiring hydraulic fluid flushing and cooling. Furthermore, the hydraulic system of an electric forklift typically uses a motor-driven hydraulic pump to supply oil for operations such as lifting and tilting. If the power is cut off, the hydraulic pump stops operating, but the working mechanism's weight-based lowering operation remains unrestricted. This could result in the forklift continuing to operate unattended, potentially leading to accidents. Therefore, to improve safety, new vehicle safety regulations require that all working mechanisms have an OPS protection feature to ensure that the operator is in the correct driving position before operation, thereby reducing accidents caused by incorrect operation.

[0003] However, the braking system of existing electric forklifts involves control oil circuits such as the service brake, parking brake, drive axle cooling, and OPS functions, so many hydraulic components are required, resulting in poor assembly and maintenance performance and high costs. Utility Model Content

[0004] In order to solve the above problems, the utility model provides an integrated valve block and a hydraulic brake system which integrate the functions of hydraulic OPS, parking brake, service brake, pilot oil source, drive axle cooling and the like.

[0005] The specific technical solutions adopted in this utility model are as follows:

[0006] The first utility model object of the present utility model is to provide a hydraulic integrated valve block, including a valve body, on which an oil inlet P0, an oil return port 1 T1, and an oil return port 2 T2 are provided; the valve body is also provided with a cooling oil port D connected to a drive axle, a pilot oil port P1 connected to a pilot handle, an energy storage oil port P2 connected to an accumulator 1, a brake oil port P3 connected to a parking brake, and a detection oil port M connected to a pressure sensor;

[0007] The oil inlet P0 is respectively connected to the pilot oil port P1, the energy storage oil port P2, the brake oil port P3, the cooling oil port D, and the detection oil port M. An OPS solenoid valve is connected between the oil inlet P0 and the pilot oil port P1, an unloading valve is connected between the oil inlet P0 and the energy storage oil port P2, a logic valve is connected between the oil inlet P0 and the cooling oil port D, and the unloading valve and the logic valve are connected through an oil circuit; the oil inlet end of the brake oil port P3 is connected to the energy storage oil port P2 through a two-position three-way solenoid valve.

[0008] In a further solution, the oil inlet P0 is connected to the energy storage oil port P2 through the throttle valve 1 and the one-way valve 2 in sequence, and the oil outlet end of the one-way valve 2 is connected to the OPS solenoid valve through the pressure reducing valve.

[0009] In a further solution, the oil outlet end of the OPS solenoid valve is connected to the pilot oil port P1 through a one-way valve 4, and the oil return end is connected to the oil return port 1 T1.

[0010] In a further solution, a throttle valve 2 and a one-way valve 3 are connected in sequence between the two-position three-way solenoid valve and the energy storage oil port P2; the return oil port of the two-position three-way solenoid valve is connected to the return oil port 2 T2 through the one-way valve 1.

[0011] In a further solution, the oil outlet end of the oil inlet P0 is connected to a relief valve, and the oil outlet end of the relief valve is connected to the second oil return port T2.

[0012] The second object of the present utility model is to provide a hydraulic braking system containing the above-mentioned hydraulic integrated valve block, wherein the oil outlet end of the energy storage oil port P2 is also connected to a foot brake valve and a power cut-off switch, the foot brake valve is connected to the service brake, and the power cut-off switch is connected to the gearbox signal.

[0013] In a further solution, the oil outlet end of the brake oil port P3 is also connected to a low-pressure alarm switch for detecting the oil pressure of the hydraulic oil entering the parking brake through the brake oil port P3.

[0014] In a further solution, the oil outlet end of the pilot oil port P1 is further connected to an accumulator 2 for supplying hydraulic oil to the forklift mast.

[0015] In a further solution, the oil inlet P0 is connected to the oil tank through a hydraulic pump, and the hydraulic pump is electrically connected to a pump motor for driving; the oil return port 1 T1 and the oil return port 2 T2 are both connected to the oil tank.

[0016] This hydraulic integrated valve block integrates control circuits for the service brake, parking brake, drive axle, and OPS functions, all connected and controlled via oil ports. This simplifies hydraulic system installation, improves installation and maintenance, and reduces costs.

[0017] The utility model detects the pressure value of the accumulator 1 by means of a pressure sensor. When the pressure value is lower than the lower limit value of the filling of the accumulator 1, the pump motor keeps working even if the electric forklift does not perform any hydraulic action, driving the hydraulic pump to always fill the accumulator 1 with liquid. When the pressure value exceeds the upper limit value of the filling of the accumulator 1, the pump motor stops working, thereby achieving an energy-saving effect.

[0018] The utility model is connected to the oil outlet end of the brake oil port P3 of the hydraulic integrated valve block with a low-pressure alarm switch, which is used to detect the pressure value of the hydraulic oil entering the parking brake. When the pressure value is lower than the pressure required to release the parking brake, the low-pressure alarm switch alarm light will light up, indicating that the pressure of the hydraulic oil is low and the entire vehicle needs to be stopped for maintenance.

[0019] The utility model installs multiple one-way valves on the internal oil circuit of the hydraulic integrated valve block, thereby controlling the flow direction of the hydraulic oil and preventing the hydraulic oil from entering the parking brake or the foot brake valve from leaking, thereby ensuring that the parking brake or the service brake is always in a released state during the driving process of the entire vehicle; at the same time, a throttle valve is added to adjust the flow of the hydraulic oil to reduce the impact of the hydraulic oil on the accumulator or the two-position three-way solenoid valve; the utility model controls the direction of the hydraulic oil through the two-position three-way solenoid valve, which is used to release the parking brake or cool the drive axle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The utility model is further described in detail below with reference to the accompanying drawings:

[0021] Figure 1 Schematic diagram of the hydraulic integrated valve block of the present invention;

[0022] Figure 2 is a schematic diagram of a hydraulic brake system of the present invention;

[0023] In the figure: 1- oil tank, 2- hydraulic pump, 3- hydraulic integrated valve block, 31- overflow valve, 32- logic valve, 33- two-position three-way solenoid valve, 34- unloading valve, 35- pressure reducing valve, 36- OPS solenoid valve, 37- one-way valve 1, 38- one-way valve 2, 39- one-way valve 3, 310- one-way valve 4, 311- throttle valve 1, 312- throttle valve 2;

[0024] 4-parking brake, 5-low pressure alarm switch, 6-accumulator 1, 7-power cut-off switch, 8-accumulator 2, 9-pressure sensor, 10-drive axle, 11-foot brake valve, 12-pilot handle. DETAILED DESCRIPTION

[0025] The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0026] In this application, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," "fixed," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or communication; direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0027] Example 1:

[0028] like Figure 1 As shown, a hydraulic integrated valve block includes a valve body, on which are provided an oil inlet P0, an oil return port 1 T1, and an oil return port 2 T2; the valve body is also provided with a cooling oil port D connected to a drive axle 10, a pilot oil port P1 connected to a pilot handle 12, an energy storage oil port P2 connected to an accumulator 1 6, a brake oil port P3 connected to a parking brake 4, and a detection oil port M connected to a pressure sensor 9;

[0029] The oil inlet P0 is respectively connected to the pilot oil port P1, the energy storage oil port P2, the brake oil port P3, the cooling oil port D, and the detection oil port M. An OPS solenoid valve 36 is connected between the oil inlet P0 and the pilot oil port P1, an unloading valve 34 is connected between the oil inlet P0 and the energy storage oil port P2, a logic valve 32 is connected between the oil inlet P0 and the cooling oil port D, and the unloading valve 34 and the logic valve 32 are connected through an oil circuit; the oil inlet end of the brake oil port P3 is connected to the energy storage oil port P2 through a two-position three-way solenoid valve 33.

[0030] The hydraulic integrated valve block of this utility model integrates the control oil circuits of the service brake, parking brake, drive axle, OPS function, etc., and connects and controls them through oil ports. This makes the system simple to install, the compact structure is easy to install and maintain, and also reduces costs.

[0031] In a further solution, the oil inlet P0 is connected to the energy storage oil port P2 through the throttle valve 1 311 and the one-way valve 2 38 in sequence, and the oil outlet end of the one-way valve 2 38 is connected to the OPS solenoid valve 36 through the pressure reducing valve 35.

[0032] In a further embodiment, the oil outlet end of the OPS solenoid valve 36 is connected to the pilot oil port P1 through the one-way valve 4 310, and the oil return end is connected to the oil return port 1 T1.

[0033] To ensure normal pressure in the braking system, pressure sensor 9 monitors the pressure in accumulator 6. When the pressure falls below the lower filling pressure limit set for accumulator 6, the pump motor remains operational, even when the forklift is not performing any hydraulic operations. This drives hydraulic pump 2 to charge accumulator 6 and maintain normal oil pressure. Hydraulic oil from inlet port P0 of the hydraulic integrated valve block 3 flows through throttle valve 1 311 and check valve 2 38 into accumulator 6 for filling. Throttle valve 1 311 primarily regulates the flow of hydraulic oil to reduce impact on accumulator 6. Check valves 2 38 and 4 310 control the direction of hydraulic oil flow.

[0034] In a further embodiment, a throttle valve 2 312 and a check valve 3 39 are sequentially connected between the two-position, three-way solenoid valve 33 and the accumulator oil port P2. The oil return port of the two-position, three-way solenoid valve 33 is connected to the oil return port 2 T2 via a check valve 1 37. The throttle valve 2 312 functions similarly to the throttle valve 1 311, also regulating the flow of hydraulic oil. The check valve 3 39 primarily prevents leakage of hydraulic oil entering the parking brake 4, thereby ensuring that the parking brake 4 remains released during vehicle operation. Similarly, the check valve 4 310 also serves to prevent leakage of pressure in the accumulator 2 8.

[0035] The oil outlet of the oil inlet P0 is connected to a relief valve 31, and the oil outlet of the relief valve 31 is connected to the oil return port 2 T2. When the hydraulic pump continues to work, excess hydraulic oil can return to the oil tank through the relief valve 31.

[0036] Example 2:

[0037] like Figure 2 The figure shows a hydraulic brake system incorporating the hydraulic integrated valve block of Example 1. The outlet of the accumulator oil port P2 is also connected to a foot brake valve 11 and a power cutoff switch 7. The foot brake valve 11 is connected to the service brake, and the power cutoff switch 7 is signal-connected to the transmission. When the brake pedal is depressed, the foot brake valve 11 opens, directing hydraulic oil from accumulator 1 through the foot brake valve 11 to the service brake, releasing the service brake. A pressure sensor electrically connected to the power cutoff switch 7 detects the oil pressure in accumulator 1 and the foot brake valve 11. When the oil pressure falls below the pressure required by the service brake, the power cutoff switch 7 is connected to the circuit and sends a signal to the transmission, causing the transmission to shut off its power output circuit.

[0038] In a further solution, the oil outlet end of the brake oil port P3 is further connected to a low-pressure alarm switch 5 for detecting the oil pressure of the hydraulic oil entering the parking brake 4 through the brake oil port P3.

[0039] The pressure threshold of the low-pressure alarm switch 5 is set according to the hydraulic oil pressure required to release the parking brake 4. When the oil pressure detected by the low-pressure alarm switch 5 is lower than the pressure threshold, the low-pressure alarm switch 5 activates the alarm, that is, the alarm light comes on, indicating that the hydraulic oil pressure is low and the vehicle needs to be stopped for maintenance.

[0040] Furthermore, the oil outlet of the pilot oil port P1 is also connected to an accumulator 2 8 for supplying hydraulic oil to the forklift mast. That is, when the vehicle stalls or malfunctions, the accumulator 2 8 can provide a certain amount of hydraulic oil to the mast to ensure that the forks can return to a safe position.

[0041] In a further solution, the oil inlet P0 is connected to the oil tank 1 through a hydraulic pump 2, and the hydraulic pump 2 is electrically connected to a pump motor for driving; the oil return port 1 T1 and the oil return port 2 T2 are both connected to the oil tank 1.

[0042] The working process of the above hydraulic brake system:

[0043] S1. After starting, the hydraulic pump 2 introduces the hydraulic oil into the hydraulic integrated valve block 3; at the same time, the pressure sensor 9 is used to instantly detect the oil pressure V0 of the accumulator 6, and the lower limit value V1 and the upper limit value V2 of the filling of the accumulator 6 are set in advance; V1 and V2 can be set according to the capacity of the accumulator.

[0044] When the oil pressure V0 is lower than the lower filling limit V1 of accumulator 1-6, the pump motor will continue to operate even if the electric forklift does not perform any hydraulic operation, driving the hydraulic pump 2 to constantly fill accumulator 1-6. In other words, the hydraulic oil from the oil inlet P0 of the integrated valve block 3 enters accumulator 1-6 through the throttle valve 1 311 and the one-way valve 2 38, thereby filling accumulator 1-6.

[0045] S2. When the oil pressure V0 reaches the upper limit V2 of the filling of accumulator 6, the unloading valve 34 is controlled to open. The hydraulic oil pushes the valve core of the logic valve 32 through the unloading valve 34 to connect the K11 and K12 oil ports. The hydraulic oil flows from the oil inlet P0 of the integrated valve block 3 through the K11 and K12 oil ports of the logic valve 32 and then into the cooling oil port D to cool the drive axle 10.

[0046] S3. When the oil pressure V0 is between V1 and V2, the unloading valve 34 is closed, the oil ports K11 and K12 of the logic valve 32 are disconnected, and the hydraulic oil discharged from the hydraulic pump 2 continues to charge the accumulator 6;

[0047] S4. Depress the brake pedal, the foot brake valve 11 opens, and the hydraulic oil in the accumulator 6 is introduced into the service brake through the foot brake valve 11 to release the service brake;

[0048] The pressure sensor electrically connected to the power cut-off switch 7 detects the oil pressure E1 of the accumulator 6 and the foot brake valve 11. When the oil pressure E1 is lower than the pressure value E0 required by the service brake, the circuit of the power cut-off switch 7 is connected and a signal is sent to the gearbox, which then cuts off its power output line switch.

[0049] S5. Pull up the parking brake switch. The two-position three-way solenoid valve 33 is energized and operates in the right position. The hydraulic oil in the accumulator 1 6 enters the parking brake 4 through the one-way valve 3 39, the two-position three-way solenoid valve 33, and the brake oil port P3, releasing the parking brake.

[0050] A low-pressure alarm switch 5 is also connected to the oil outlet end of the brake oil port P3. The low-pressure alarm switch 5 detects the pressure value F1 of the hydraulic oil entering the parking brake 4. When the pressure value F1 is lower than the pressure F0 required to release the parking brake 4, the low-pressure alarm switch 5 alarms, that is, the alarm light comes on, indicating that the pressure of the hydraulic oil is low and the entire vehicle needs to be stopped for inspection.

[0051] S6. When the parking brake switch is pressed, the two-position three-way solenoid valve 33 loses power and works in the left position. The hydraulic oil in the accumulator 16 enters the drive axle 10 through the one-way valve 39, the two-position three-way solenoid valve 33, and the cooling oil port D to cool it. When the hydraulic oil pressure is too high, the one-way valve 137 will open and return to the oil tank. Here, the one-way valve 137 can be set as a pressure-limiting valve. When a certain pressure is reached, the oil circuit will be opened.

[0052] When the low-pressure alarm switch 5 detects that the pressure value F1 of the hydraulic oil entering the parking brake 4 is lower than the pressure F0 required for the parking brake 4 to release the brake, the low-pressure alarm switch 5 lights up and alarms, and the parking brake of the electric forklift is locked.

[0053] S7. Operate the pilot handle 12 to first detect the driver's position. The switch of the OPS solenoid valve 36 is installed under the cab seat. When the driver is in the normal working position, the switch of the OPS solenoid valve 36 is turned on and energized. The hydraulic oil output from the hydraulic pump 2 is sequentially introduced into the pilot handle 12 through the oil inlet P0, the throttle valve 1 311, the check valve 2 38, the pressure reducing valve 35, and the OPS solenoid valve 36 for pilot operation.

[0054] When the driver is not in the normal working position, the OPS solenoid valve 36 loses power, and the hydraulic oil flows through the oil inlet P0, throttle valve 1 311, check valve 2 38, pressure reducing valve 35, and OPS solenoid valve 36 in sequence, and then flows back to the fuel tank 1 from the oil return port 1 T1. In other words, the oil supply line to the pilot handle 12 is cut off, and the forklift does not move when the pilot handle 12 is operated.

[0055] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application are within the scope of protection of the pending claims of the present application.

Claims

1. A hydraulic integrated valve block, comprising a valve body, characterized in that: The valve body is provided with an oil inlet P0, an oil return port 1 T1 and an oil return port 2 T2; the valve body is also provided with a cooling oil port D connected to a drive axle (10), a pilot oil port P1 connected to a pilot handle (12), an energy storage oil port P2 connected to an energy storage device 1 (6), a brake oil port P3 connected to a parking brake (4), and a detection oil port M connected to a pressure sensor (9); The oil inlet P0 is connected to the pilot oil port P1, the energy storage oil port P2, the brake oil port P3, the cooling oil port D, and the detection oil port M respectively; an OPS solenoid valve (36) is connected between the oil inlet P0 and the pilot oil port P1; an unloading valve (34) is connected between the oil inlet P0 and the energy storage oil port P2; a logic valve (32) is connected between the oil inlet P0 and the cooling oil port D; and the unloading valve (34) and the logic valve (32) are connected via an oil circuit; the oil inlet end of the brake oil port P3 is connected to the energy storage oil port P2 via a two-position three-way solenoid valve (33).

2. The hydraulic integrated valve block according to claim 1, characterized in that: The oil inlet P0 is connected to the energy storage oil port P2 through the throttle valve 1 (311) and the one-way valve 2 (38) in sequence, and the oil outlet end of the one-way valve 2 (38) is connected to the OPS solenoid valve (36) through the pressure reducing valve (35).

3. The hydraulic integrated valve block according to claim 2, characterized in that: The oil outlet end of the OPS solenoid valve (36) is connected to the pilot oil port P1 through a one-way valve (310), and the oil return end is connected to the oil return port T1.

4. The hydraulic integrated valve block according to claim 1, characterized in that: A throttle valve 2 (312) and a check valve 3 (39) are sequentially connected between the two-position three-way solenoid valve (33) and the energy storage oil port P2; the oil return port of the two-position three-way solenoid valve (33) is connected to the oil return port 2 T2 via a check valve 1 (37).

5. The hydraulic integrated valve block according to claim 1, characterized in that: The oil outlet end of the oil inlet P0 is connected to a relief valve (31), and the oil outlet end of the relief valve (31) is connected to the second oil return port T2.

6. A hydraulic brake system comprising the hydraulic integrated valve block according to any one of claims 1 to 5, characterized in that: The oil outlet end of the energy storage oil port P2 is also connected to a foot brake valve (11) and a power cut-off switch (7); the foot brake valve (11) is connected to the service brake, and the power cut-off switch (7) is connected to a transmission signal.

7. The hydraulic brake system according to claim 6, characterized in that: The oil outlet end of the brake oil port P3 is also connected to a low-pressure alarm switch (5) for detecting the oil pressure of the hydraulic oil entering the parking brake (4) through the brake oil port P3.

8. The hydraulic brake system according to claim 6, characterized in that: The oil outlet end of the pilot oil port P1 is also connected to an accumulator 2 (8) for supplying hydraulic oil to the forklift mast.

9. The hydraulic brake system according to claim 6, characterized in that: The oil inlet P0 is connected to the oil tank (1) via a hydraulic pump (2), and the hydraulic pump (2) is electrically connected to a pump motor for driving; the oil return port 1 T1 and the oil return port 2 T2 are both connected to the oil tank (1).

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