Hydraulic brake circuit control system and reach truck

Abstract

The application discloses a hydraulic brake circuit control system and a telescopic arm forklift. The hydraulic brake circuit control system comprises a service brake circuit, a vehicle axle brake, a service brake valve and a flow regulating valve. A working oil port on one side of the service brake valve is connected with the vehicle axle brake through a service brake working oil path to control the liquid filling or discharging of the vehicle axle brake. The hydraulic pump is connected with an oil inlet on the other side of the service brake valve through a first pumping oil path, and the flow regulating valve is arranged in the first pumping oil path to regulate the flow of the liquid filling or discharging of the vehicle axle brake. The application cancels the traditional liquid filling valve and liquid filling circuit, directly supplies brake oil to the service brake circuit through the hydraulic pump, fully supplies the brake oil liquid, has a quick response, and simplifies the whole brake system. For vehicle axle brakes of different specifications and sizes, the flow regulating valve can regulate the flow, thereby regulating the service brake response time, and the generality is better.

Description

Technical Field

[0001] This application belongs to the field of hydraulic control of engineering vehicles, specifically relating to a telescopic boom forklift and its hydraulic braking circuit control system. Background Technology

[0002] Telescopic forklifts are off-road, high-speed material handling machines, and braking control is essential during travel and parking. For example... Figure 1 As shown, the commonly used fully hydraulic braking circuit in telescopic forklifts typically requires a filling valve 15, multiple pressure sensors, and an accumulator 9, with the braking energy primarily derived from the energy stored in the accumulator 9. (Refer to...) Figure 1 When the hydraulic pump starts, it first charges the accumulator 9 through the charging valve 15. When the accumulator pressure reaches the set pressure of the charging valve, the charging valve 15 switches the hydraulic system to the bypass oil circuit.

[0003] This type of fully hydraulic braking circuit is quite complex. The braking energy supply relies entirely on the oil stored in the accumulator, so many pressure relays for pressure detection need to be added to the circuit, resulting in high costs. At the same time, the filling pressure of the filling valve is affected by the bypass load, and the filling time of the accumulator is limited by the flow rate of the filling valve, so the system output flow cannot be adjusted as needed. Summary of the Invention

[0004] The purpose of this application is to provide a hydraulic braking circuit control system and a telescopic forklift, which has a simpler and more reliable braking system and a controllable and adjustable braking response time.

[0005] To achieve the above objectives, the first aspect of this application provides a hydraulic braking circuit control system, the hydraulic braking circuit control system comprising:

[0006] The service brake circuit includes an axle brake, a service brake valve, and a flow regulating valve. The working port on one side of the service brake valve is connected to the axle brake through the service brake working oil circuit to control the filling or draining of the axle brake.

[0007] A hydraulic pump is connected to the inlet on the other side of the service brake valve via a first pumping oil circuit. The flow regulating valve is located in the first pumping oil circuit to regulate the flow rate of the axle brake filling or draining fluid.

[0008] In some embodiments, the flow regulating valve is a pressure-compensated flow regulating valve whose flow rate is unaffected by the load.

[0009] In some embodiments, the service braking circuit includes:

[0010] An accumulator serves as an auxiliary power source for vehicle braking and is connected in parallel with the first pumping oil circuit to the oil inlet of the vehicle brake valve.

[0011] In some embodiments, the service braking circuit includes:

[0012] A service brake pressure relay is used to monitor the service brake pressure in the service brake working oil circuit in real time, and to trigger an alarm signal when the service brake pressure is lower than a set value; and

[0013] The control signal pressure relay is used to monitor the service brake pressure in the service brake working oil circuit and trigger the brake light signal when the service brake pressure is greater than the set pressure.

[0014] In some embodiments, the hydraulic braking circuit control system includes:

[0015] A parking brake circuit includes a parking brake and a parking directional valve for controlling the filling or draining of the parking brake.

[0016] The oil inlet on one side of the parking directional valve is connected to the hydraulic pump through a second pumping oil circuit, and the first pumping oil circuit and the second pumping oil circuit are arranged in parallel.

[0017] In some embodiments, the working port on the other side of the parking directional valve is connected to the parking brake via a parking control working oil circuit, and the parking control working oil circuit is equipped with a one-way throttle valve.

[0018] In some embodiments, the one-way throttle valve includes a one-way valve and an adjustable flow valve arranged in parallel.

[0019] In some embodiments, the parking brake circuit includes:

[0020] A pressure-reducing relief valve is installed in the second pumping oil circuit.

[0021] In some embodiments, the parking brake circuit includes:

[0022] The parking pressure relay is used to monitor the parking brake pressure in the parking control oil circuit in real time, and to trigger an alarm signal when the parking brake pressure is lower than a safety preset value.

[0023] In some embodiments, the hydraulic braking circuit control system includes:

[0024] A main check valve is located at the pump port of the hydraulic pump and is used to prevent hydraulic oil from flowing back into the pump. The second pumping oil circuit is connected downstream of the main check valve.

[0025] A second aspect of this application also provides a telescopic forklift, the telescopic forklift including the hydraulic braking circuit control system described above according to this application.

[0026] In the hydraulic brake circuit control system and telescopic forklift of this application, the traditional filling valve and filling circuit are eliminated. Brake fluid is directly supplied to the service brake circuit via a hydraulic pump, resulting in ample brake fluid supply, fast response, and a simplified braking system. Furthermore, for axle brakes of different sizes, the flow rate can be adjusted via a flow regulating valve, thereby regulating the service brake response time and adapting to situations with large variations in brake displacement in forklifts.

[0027] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0028] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:

[0029] Figure 1 Hydraulic schematic diagram of the fully hydraulic braking circuit for existing telescopic forklifts; and

[0030] Figure 2 This is a hydraulic schematic diagram of the hydraulic braking circuit control system of a telescopic boom forklift according to a specific embodiment of this application.

[0031] Explanation of reference numerals in the attached figures

[0032] 1. Hydraulic pump 2. Main check valve

[0033] 3 Main relief valve 4 Pressure reducing relief valve

[0034] 5 Parking directional valve 6 Parking pressure relay

[0035] 7. One-way throttle valve 8. Flow regulating valve

[0036] 9. Accumulator 10. Service brake valve

[0037] 11 Service brake pressure relay 12 Control signal pressure relay

[0038] 13 Axle brakes 14 Parking brakes

[0039] 15 Filling valve

[0040] L0 Service brake working oil circuit; L1 First pumping oil circuit

[0041] L2 Second Pump Oil Circuit; L3 Parking Control Working Oil Circuit Detailed Implementation

[0042] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0043] The hydraulic braking circuit control system and telescopic forklift according to this application are described below with reference to the accompanying drawings.

[0044] This application discloses a hydraulic braking circuit control system. For example... Figure 2 As shown, in one specific embodiment, the hydraulic braking circuit control system includes:

[0045] The service brake circuit includes an axle brake 13, a service brake valve 10, and a flow regulating valve 8. The working oil port on one side of the service brake valve 10 is connected to the axle brake 13 through the service brake working oil circuit L0 to control the filling or draining of the axle brake 13.

[0046] The hydraulic pump 1 is connected to the oil inlet on the other side of the service brake valve 10 through the first pumping oil circuit L1. The flow regulating valve 8 is installed in the first pumping oil circuit L1 to regulate the flow rate of filling or draining the axle brake 13.

[0047] Compared to Figure 1 The hydraulic braking method shown has drawbacks such as high cost, system complexity, and difficulty in arranging in confined spaces. Figure 2 In the embodiment shown, the filling valve and filling circuit are eliminated, the filling pressure is not affected by the bypass load, and the hydraulic pump 1 directly supplies brake fluid to the service brake circuit, instead of mainly supplying brake fluid through the accumulator 9. The brake fluid supply is sufficient, the response is fast, and the entire braking system is simplified. Moreover, the flow rate is adjusted only by the flow regulating valve 8, thereby adjusting the service brake response time to adapt to situations such as large changes in the brake displacement of the forklift.

[0048] The flow regulating valve 8 can be a pressure-compensated flow regulating valve whose flow rate is unaffected by the load. It can adjust the flow rate according to the actual needs of the axle brake 13, thereby adjusting the vehicle braking response time. Because the flow rate is unaffected by the load, the flow regulation of the flow regulating valve 8 is reliable and stable. Obviously, the opening of the flow regulating valve 8 can be adjusted accordingly for different sizes of axle brakes 13 to ensure compatibility. During operation, manual adjustment can be used, allowing for a one-time adjustment tailored to the specifications of the axle brake 13.

[0049] It should be noted that pressure-compensated flow control valves whose flow rate is unaffected by load are well known to those skilled in the art, so the internal structure of the valve body will not be described in detail here.

[0050] When the vehicle needs to brake while driving, the driver presses the pedal of the service brake valve 10. The pressurized oil pumped from the hydraulic pump 1 passes through the flow regulating valve 8 and the service brake valve 10 to reach the axle brake 13, thereby achieving braking.

[0051] To further improve braking reliability, Figure 2 The service braking circuit also includes:

[0052] The accumulator 9 serves as an auxiliary power source for the vehicle's braking system and is connected in parallel with the first pumping oil circuit L1 to the oil inlet of the vehicle's brake valve 10.

[0053] The accumulator 9 and the first pumping oil circuit L1 with the flow regulating valve 8 are connected in parallel to the oil inlet of the service brake valve 10, serving as the dual oil source for the service brake working oil circuit L0. The accumulator 9 is only an auxiliary power source for the service brake. When the engine starts, the hydraulic pump 1 outputs high-pressure oil to fill the accumulator 9. During vehicle operation, when a complete machine failure causes the engine to be unable to provide power, the oil in the accumulator 9 can supply the service brake valve 10 for braking.

[0054] also, Figure 2 The service braking circuit also includes:

[0055] Service brake pressure relay 11 is used to monitor the service brake pressure in the service brake working oil circuit L0 in real time, and trigger an alarm signal when the service brake pressure is lower than the set value; and

[0056] The control signal pressure relay 12 is used to monitor the service brake pressure in the service brake working oil circuit L0 and trigger the brake light signal when the service brake pressure is greater than the set pressure.

[0057] In other words, the service brake pressure relay 11 can monitor the service brake pressure in real time. When the brake pressure is insufficient, the service brake pressure relay 11 will sound an alarm, prompting the driver to stop for maintenance or to apply emergency braking. Similarly, the control signal pressure relay 12 will trigger a signal to control the opening and closing of the brake lights when the brake pressure is sufficient to brake the axle brake 13.

[0058] The hydraulic pump 1 pumps pressurized oil not only to the axle brake 13, but also to the parking brake 14. (See also...) Figure 2 The hydraulic braking circuit control system also includes a parking brake circuit, which includes a parking brake 14 and a parking directional valve 5 for controlling the filling or draining of the parking brake 14; wherein, the oil inlet on one side of the parking directional valve 5 is connected to the hydraulic pump 1 through the second pumping oil circuit L2, and the first pumping oil circuit L1 and the second pumping oil circuit L2 are set in parallel.

[0059] Among them, the working oil port on the other side of the parking reversing valve 5 is connected to the parking brake 14 through the parking control working oil circuit L3, and a one-way throttle valve 7 is provided in the parking control working oil circuit L3.

[0060] When the forklift needs to be driven on the road, the parking directional valve 5 is energized and switched to the lower position. At this time, the pressurized oil pumped from the hydraulic pump 1 passes through the parking directional valve 5 and opens the parking brake 14, releasing the vehicle's parking brake and allowing the vehicle to move. When the vehicle needs emergency braking, the emergency brake button is operated, causing the parking directional valve 5 to be de-energized. At this time, the parking brake 14 discharges oil under the action of spring force. The discharged oil returns to the oil tank through the one-way throttle valve 7 and the parking directional valve 5.

[0061] At this time, due to the presence of the one-way throttle valve 7, the oil discharged from the parking brake 14 can be controlled, serving as a delay buffer. In this embodiment, the one-way throttle valve 7 includes a one-way valve and an adjustable flow valve arranged in parallel. This allows for a quick-opening and slow-closing effect. When driving on the road is required, the pumped pressurized oil can quickly reach the parking brake 14 through the one-way valve in the one-way throttle valve 7 to release the parking brake. When the vehicle needs emergency braking, the discharged oil returns through the adjustable flow valve in the one-way throttle valve 7 at a slower speed, thus preventing sudden braking and providing a certain buffering effect.

[0062] Since the flow rate and pressure of the brake fluid in the second pumping oil circuit L2 are not large, they are sufficient to meet the requirements of the parking brake 14. Figure 2 The parking brake circuit also includes a pressure relief valve 4, which is located in the second pumping oil circuit L2. The relief valve 4 ensures that the pressure in the parking brake circuit meets the braking pressure requirements. Furthermore, the parking brake circuit also includes a parking pressure relay 6, which monitors the parking brake pressure in the parking control working oil circuit L3 in real time and triggers an alarm signal when the parking brake pressure is lower than a safety preset value, prompting the driver to stop for inspection.

[0063] In addition, the hydraulic braking circuit control system also includes a main check valve 2, which is located at the pump port of the hydraulic pump 1 and is used to prevent hydraulic oil from flowing back into the pump. The second pumping oil circuit L2 is connected to the downstream of the main check valve 2.

[0064] In addition, the hydraulic brake circuit control system also includes a main relief valve 3. The main relief valve 3 acts as a safety valve and is connected between the main check valve 2 and the oil tank. When the oil pressure in the first pumping oil circuit L1 or the second pumping oil circuit L2 exceeds the set pressure of the main relief valve 3, it will overflow back to the oil tank, which can protect the entire brake control circuit.

[0065] This application also discloses a telescopic boom forklift, including the aforementioned hydraulic braking circuit control system. Given the highly variable axle brake displacement requirements of forklifts, existing hydraulic braking methods are costly, complex, and unsuitable for confined spaces. Therefore, in this application's embodiment, a flow regulating valve 8 is installed in the service brake circuit. This valve adjusts the flow rate according to the actual needs of the axle brakes, thereby regulating the response time. This eliminates the need for a hydraulic charging circuit, simplifies the entire braking system, and is unaffected by existing bypass pressure. Furthermore, a throttle valve 7 is added to the parking brake circuit, which can act as a buffer during emergency braking.

[0066] It should be noted that the hydraulic braking circuit control system of this application is not limited to use in telescopic boom forklifts, but can also be more widely applied to other engineering vehicles.

[0067] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0068] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0069] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0070] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A hydraulic braking circuit control system, characterized in that, The hydraulic braking circuit control system includes: The service brake circuit includes an axle brake (13), a service brake valve (10), a flow regulating valve (8), a service brake pressure relay (11), and a control signal pressure relay (12). The working port on one side of the service brake valve (10) is connected to the axle brake (13) through the service brake working oil circuit (L0) to control the filling or draining of the axle brake (13). The service brake pressure relay (11) is used to monitor the service brake pressure of the service brake working oil circuit (L0) in real time and trigger an alarm signal when the service brake pressure is lower than the set value. The control signal pressure relay (12) is used to monitor the service brake pressure of the service brake working oil circuit (L0) and trigger a brake light signal when the service brake pressure is greater than the set pressure. A hydraulic pump (1) is connected to the inlet on the other side of the service brake valve (10) via a first pumping oil passage (L1). A flow regulating valve (8) is located in the first pumping oil passage (L1) to regulate the flow rate of the axle brake (13) during filling or draining. The parking brake circuit includes a parking brake (14) and a parking directional valve (5) for controlling the filling or draining of the parking brake (14). The oil inlet on one side of the parking directional valve (5) is connected to the hydraulic pump (1) through the second pumping oil circuit (L2). The first pumping oil circuit (L1) and the second pumping oil circuit (L2) are connected in parallel. The working oil port on the other side of the parking directional valve (5) is connected to the parking brake (14) through the parking control working oil circuit (L3). The parking control working oil circuit (L3) is provided with a one-way throttle valve (7). The one-way throttle valve (7) includes a one-way valve and an adjustable flow valve connected in parallel.

2. The hydraulic braking circuit control system according to claim 1, characterized in that, The flow regulating valve (8) is a pressure-compensated flow regulating valve whose flow rate is not affected by the load.

3. The hydraulic braking circuit control system according to claim 1, characterized in that, The service braking circuit includes: The accumulator (9) serves as an auxiliary power source for the vehicle braking system and is connected in parallel with the first pumping oil circuit (L1) to the oil inlet of the vehicle braking valve (10).

4. The hydraulic braking circuit control system according to claim 1, characterized in that, The parking brake circuit includes: A pressure-reducing relief valve (4) is installed in the second pumping oil circuit (L2).

5. The hydraulic braking circuit control system according to claim 1, characterized in that, The parking brake circuit includes: The parking pressure relay (6) is used to monitor the parking brake pressure of the parking control working oil circuit (L3) in real time, and to trigger an alarm signal when the parking brake pressure is lower than the safety preset value.

6. The hydraulic braking circuit control system according to claim 1, characterized in that, The hydraulic braking circuit control system includes: The main check valve (2) is located at the pump port of the hydraulic pump (1) and is used to prevent hydraulic oil from flowing back into the pump. The second pumping oil passage (L2) is connected to the valve downstream of the main check valve (2).

7. A telescopic boom forklift, characterized in that, The telescopic forklift includes a hydraulic braking circuit control system according to any one of claims 1 to 6.

Images