Forklift braking system and forklift

Abstract

The utility model relates to the technical field of forklift braking, in particular to a forklift braking system and a forklift. The brake system comprises a prefill valve, an oil inlet of the prefill valve is connected with an oil outlet of a gear oil pump, and an oil outlet of the prefill valve is connected with an energy accumulator; an oil inlet of the hydraulic brake valve is connected between an oil outlet of the prefill valve and the energy accumulator, and a working oil port of the hydraulic brake valve is connected with a brake caliper of a brake disc; a first control end of the hydraulic brake valve is connected with a brake pedal, and when the brake pedal is stepped down, an oil inlet of the hydraulic brake valve is communicated with a working oil port; the one-way valve group is arranged between a working oil port of the hydraulic brake valve and a brake caliper of the brake disc; the one-way valve set is used for enabling the working oil port of the hydraulic brake valve to be communicated with the brake caliper in a one-way mode when the pressure of the working oil port of the hydraulic brake valve reaches a preset threshold value. According to the utility model, the gear oil pump of the forklift system is connected with the prefill valve to provide high-pressure oil, so that the braking force is effectively improved, and an additional power-assisted mechanism is not needed.

Description

Technical Field

[0001] This utility model relates to the field of forklift braking technology, specifically to a forklift braking system and a forklift. Background Technology

[0002] Hydraulic braking systems are a key technology in heavy-duty forklifts (such as 7-ton class), and still hold an important position, especially in traditional internal combustion forklifts and some electric forklifts. The core components of a hydraulic braking system consist of a master cylinder, brake calipers, brake discs / drums, hydraulic lines, and valves. For some models, due to overall height and space limitations, most of the space is occupied by existing basic components, making the design, installation, and maintenance of other components extremely inconvenient. To meet specific requirements and space constraints, how to rationally arrange the positions of various components and design an efficient braking system is a pressing issue that needs to be addressed in heavy-duty forklift development.

[0003] The existing working principle of forklift hydraulic braking is as follows: the driver presses the pedal → the master cylinder compresses the brake fluid → the hydraulic pressure is transmitted to the wheel cylinders → the wheel cylinders push the friction pads to press against the brake discs → generating braking torque. This system relies on Pascal's law (uniform transmission of pressure in a closed fluid), exhibiting force amplification characteristics, making it suitable for heavy equipment. Traditional hydraulic braking (mechanical): relies entirely on manual or vacuum assistance; its structure is simple but its braking force is limited, and due to space constraints, it is difficult to install additional assist structures. Utility Model Content

[0004] The purpose of this utility model is to provide a forklift braking system and forklift. The system uses a gear oil pump connected to a filling valve to provide high-pressure oil, which effectively improves the braking force without the need for an additional power assist mechanism. When the brake pedal is depressed, the brake valve switches to open, allowing the hydraulic oil output from the filling valve to flow into the brake caliper through the brake valve and the check valve assembly. The check valve assembly only opens when the pressure at the working port of the brake valve reaches a threshold, thereby achieving the goal of improving braking force while ensuring the safe use of the hydraulic system.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, this utility model provides a forklift braking system, which includes:

[0007] The filling valve has an inlet port connected to the outlet port of the gear oil pump, and the outlet port is connected to the accumulator.

[0008] The hydraulic brake valve has an inlet port connected between the outlet port of the filling valve and the accumulator, and a working port connected to the brake caliper of the brake disc; the first control end of the hydraulic brake valve is connected to the brake pedal, and when the brake pedal is depressed, the inlet port and the working port of the hydraulic brake valve are connected.

[0009] A one-way valve assembly is located between the working port of the hydraulic brake valve and the brake caliper of the brake disc; the one-way valve assembly is used to ensure unidirectional flow of the oil circuit between the working port of the hydraulic brake valve and the brake caliper of the brake disc when the pressure at the working port of the hydraulic brake valve reaches a preset threshold.

[0010] Optionally, the control port of the filling valve is connected to a pressure switch, which is used to control the oil outlet pressure of the filling valve.

[0011] Optionally, the hydraulic brake valve includes a connecting working position, a cutting-off working position, and a return working position; when the brake pedal is depressed, the hydraulic brake valve switches to the connecting working position, and the oil inlet and working port of the hydraulic brake valve are connected.

[0012] Optionally, the second control terminal of the hydraulic brake valve is connected to a control switch. When the control switch is turned on, the hydraulic brake valve switches to the return oil working position, and the working oil port and the return oil port of the hydraulic brake valve are connected.

[0013] Optionally, when the brake pedal is not depressed and the control switch is closed, the hydraulic brake valve is in the off working position, and the oil inlet, working oil port and return oil port of the hydraulic brake valve are all closed.

[0014] Optionally, the one-way valve assembly includes a first oil circuit, on which a first one-way valve and a spring are provided; when the hydraulic brake valve is in the connected working position and the working oil port pressure of the hydraulic brake valve reaches a preset threshold, the spring is compressed, and the hydraulic oil output from the working oil port of the hydraulic brake valve is delivered to the brake caliper of the brake disc through the first one-way valve.

[0015] Optionally, the preset threshold is 1 bar.

[0016] Optionally, the one-way valve assembly further includes a second oil circuit connected in parallel with the first oil circuit. A second one-way valve is provided on the second oil circuit. When the hydraulic brake valve is in the return oil working position, the hydraulic oil withdrawn from the brake caliper of the brake disc can be connected to the working oil port of the hydraulic brake valve through the second one-way valve.

[0017] Optionally, the energy storage device is a bladder-type energy storage device.

[0018] Secondly, this utility model provides a forklift that includes the aforementioned forklift braking system.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] In the braking system of this invention, the inlet of the filling valve is connected to the outlet of the gear oil pump of the forklift system itself. This allows the engine power of the forklift system to be used for auxiliary pressurization, effectively improving braking force and reducing the driver's pedal force. Furthermore, when the driver depresses the brake pedal, the brake control valve switches direction, allowing the high-pressure oil output from the gear oil pump to be delivered to the brake caliper via the filling valve, hydraulic brake valve, and check valve assembly to complete braking. The check valve assembly only opens when the pressure at the brake valve's working port reaches a threshold, thus reducing pedal force and improving the response speed of the hydraulic brake valve while ensuring the safe operation of the hydraulic system. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the forklift braking system in Example 1;

[0022] Figure 2 for Figure 1 A structural diagram from another perspective;

[0023] Figure 3 This is a hydraulic schematic diagram of the forklift braking system in Example 1.

[0024] The following are the labels in the diagram: 1. Filling valve; 2. Accumulator; 3. Hydraulic brake valve; 4. Brake pedal; 5. Check valve assembly; 51. First check valve; 52. Second check valve; 6. Brake caliper. Detailed Implementation

[0025] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention. Example 1

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0028] Combination Figure 1 and Figure 2 This embodiment provides a forklift braking system, which includes a filling valve 1, an accumulator 2, and a hydraulic brake valve 3. Combined with... Figure 3 The hydraulic schematic diagram of the forklift braking system is explained in detail below, specifically the oil inlet of the filling valve 1 ( Figure 2 The P port is connected to the outlet of the gear oil pump. In this embodiment, the gear pump inside the forklift system is used as the power source of the braking system to provide the required braking pressure inside the braking system. There is no need to arrange an additional booster structure, so there is no difficulty in space arrangement and the braking force of the system can be effectively improved.

[0029] The inlet of the filling valve 1 (port P in the attached drawing) is connected to the outlet of the gear oil pump, and the outlet of the filling valve 1 (port A in the attached drawing) is connected to the accumulator 2. In one specific embodiment, the filling valve 1 is a single-circuit filling valve, which can quickly fill the accumulator 2 with hydraulic oil. The control port of the filling valve 1 (port SW in the attached drawing) is connected to a pressure switch, which controls the outlet pressure of the filling valve 1. After the outlet pressure of the filling valve 1 reaches a preset pressure, the filling is automatically cut off to protect the system safety. In this embodiment, the accumulator 2 is a bladder-type accumulator, but it can also be other energy storage devices with the same function in the prior art. The return port of the filling valve 1 (port T in the attached drawing) is connected to the return oil tank.

[0030] The inlet of the hydraulic brake valve 3 (port P in the attached figure) is connected between the outlet of the filling valve 1 and the accumulator 2, and the working port (port A in the attached figure) is connected to the brake caliper 6 of the brake disc. The first control end of the hydraulic brake valve 3 is connected to the brake pedal 4. When the brake pedal 4 is depressed, the inlet and working port of the hydraulic brake valve 3 are connected. A one-way valve group 5 is provided between the working port of the hydraulic brake valve 3 and the brake caliper 6 of the brake disc. The one-way valve group 5 is used to make the oil circuit between the working port of the hydraulic brake valve 3 and the brake caliper 6 of the brake disc unidirectional when the pressure of the working port of the hydraulic brake valve 3 reaches a preset threshold. In one specific embodiment, the one-way valve assembly 5 includes a first oil circuit, on which a first one-way valve 51 and a spring are provided. When the hydraulic brake valve 3 is in the connected working position and the working port pressure of the hydraulic brake valve 3 reaches a preset threshold (as an optional typical value, the preset threshold here is 1 bar), the spring is compressed, and the hydraulic oil output from the working port of the hydraulic brake valve 3 is delivered to the brake caliper 6 of the brake disc through the first one-way valve 51. In some specific embodiments, the single-circuit filling valve 1 in this embodiment can also be replaced by a hydraulic valve with other control methods, such as electronic control or pneumatic control.

[0031] To explain the hydraulic oil flow, when the brake pedal 4 is depressed, the hydraulic oil output from the outlet of the filling valve 1 (if the vehicle is not started or the gear pump malfunctions, the accumulator 2 is needed as a backup power source; the hydraulic oil output here is from inside the accumulator 2) passes through the inlet and working port of the hydraulic brake valve 3, and then through the first oil circuit of the one-way valve group 5 to the brake caliper 6 of the brake disc to complete braking. In this embodiment, by controlling the hydraulic brake valve 3 and the one-way valve group 5, the high-pressure oil output from the gear pump can be stably delivered to the brake caliper 6 of the brake disc for braking when the brake pedal 4 is depressed, thereby ensuring the safety of the hydraulic system while increasing braking force through the gear pump.

[0032] Specifically, the hydraulic brake valve 3 includes a connected working position, a cut-off working position, and a return oil working position. When the brake pedal 4 is depressed, the hydraulic brake valve 3 switches to the connected working position, and the inlet and working oil ports of the hydraulic brake valve 3 are connected. A control switch is connected to the second control terminal of the hydraulic brake valve 3. When the control switch is open, the hydraulic brake valve 3 switches to the return oil working position, and the working oil port and the return oil port (T port in the attached diagram) of the hydraulic brake valve 3 are connected. When the brake pedal 4 is not depressed and the control switch is closed, the hydraulic brake valve 3 is in the cut-off working position, and the inlet, working oil port, and return oil port of the hydraulic brake valve 3 are all closed. Figure 2 In one specific embodiment, the connecting working position, the cutting-off working position, and the oil return working position are respectively the upper position, the middle position, and the lower position of the hydraulic brake valve 3. The brake pedal 4 is connected to the upper end of the hydraulic brake valve 3, and the control switch is connected to the lower end of the hydraulic brake valve 3. In one specific embodiment, the control switch can be electrically controlled, hydraulically controlled, or pneumatically controlled.

[0033] In this embodiment, the hydraulic brake valve 3 has three working positions. In the braking state, i.e., when the brake pedal 4 is depressed, the hydraulic brake valve 3 is in the connected working position, allowing hydraulic oil to flow to the brake disc to complete braking. When the hydraulic brake valve 3 is in the return working position, the hydraulic oil in the brake caliper 6 of the brake disc needs to exit and flow back to the oil tank. To achieve this oil flow, the one-way valve assembly 5 in this embodiment also includes a second oil circuit connected in parallel with the first oil circuit. The second oil circuit is equipped with a second one-way valve 52. When the hydraulic brake valve 3 is in the return working position, the hydraulic oil exiting from the brake caliper 6 of the brake disc can be connected to the working port of the hydraulic brake valve 3 through the second one-way valve 52, and then connected to the oil tank through the return port of the hydraulic brake valve 3 to complete the return. In this embodiment, the one-way valves of the first and second oil circuits are arranged in opposite directions to avoid hydraulic oil cross-flow. Example 2

[0034] Based on the same inventive concept as Embodiment 1, this embodiment provides a forklift that includes the forklift braking system described in Embodiment 1.

[0035] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A forklift braking system, characterized in that, include: The filling valve (1) has an inlet port connected to the outlet port of the gear oil pump and an outlet port connected to the accumulator (2). The hydraulic brake valve (3) has an inlet port connected between the outlet port of the filling valve (1) and the accumulator (2), and a working port connected to the brake caliper (6); the first control end of the hydraulic brake valve (3) is connected to the brake pedal (4), and when the brake pedal (4) is pressed, the inlet port and the working port of the hydraulic brake valve (3) are connected. A one-way valve assembly (5) is provided between the working port of the hydraulic brake valve (3) and the brake caliper (6); the one-way valve assembly (5) is used to make the oil circuit between the working port of the hydraulic brake valve (3) and the brake caliper (6) unidirectionally open when the pressure of the working port of the hydraulic brake valve (3) reaches a preset threshold.

2. The forklift braking system according to claim 1, characterized in that, The control port of the filling valve (1) is connected to a pressure switch, which is used to control the oil outlet pressure of the filling valve (1).

3. The forklift braking system according to claim 1, characterized in that, The hydraulic brake valve (3) includes a connecting working position, a cutting-off working position and a return working position; when the brake pedal (4) is pressed, the hydraulic brake valve (3) switches to the connecting working position, and the oil inlet and working oil port of the hydraulic brake valve (3) are connected.

4. The forklift braking system according to claim 3, characterized in that, The second control terminal of the hydraulic brake valve (3) is connected to a control switch. When the control switch is turned on, the hydraulic brake valve (3) switches to the return oil working position, and the working oil port and the return oil port of the hydraulic brake valve (3) are connected.

5. The forklift braking system according to claim 4, characterized in that, When the brake pedal (4) is not depressed and the control switch is closed, the hydraulic brake valve (3) is in the cut-off working position, and the oil inlet, working oil port and return oil port of the hydraulic brake valve (3) are all cut off.

6. The forklift braking system according to claim 4, characterized in that, The one-way valve group (5) includes a first oil circuit, on which a first one-way valve (51) and a spring are provided; when the hydraulic brake valve (3) is in the connected working position and the working oil port pressure of the hydraulic brake valve (3) reaches a preset threshold, the spring is compressed, and the hydraulic oil output from the working oil port of the hydraulic brake valve (3) is delivered to the brake caliper (6) through the first one-way valve (51).

7. The forklift braking system according to claim 6, characterized in that, The preset threshold is 1 bar.

8. The forklift braking system according to claim 6, characterized in that, The one-way valve group (5) also includes a second oil circuit connected in parallel with the first oil circuit. A second one-way valve (52) is provided on the second oil circuit. When the hydraulic brake valve (3) is in the return oil working position, the hydraulic oil withdrawn from the brake caliper (6) can be connected to the working oil port of the hydraulic brake valve (3) through the second one-way valve (52).

9. The forklift braking system according to claim 1, characterized in that, The accumulator (2) is a bladder-type accumulator (2).

10. A forklift, characterized in that, Includes the forklift braking system as described in any one of claims 1-9.

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