An automatic parking control system and method for forklift ramps

Abstract

This invention discloses an automatic parking control system and method for forklifts on ramps, belonging to the field of forklift control technology. The hydraulic control section includes a hydraulic accumulator; the hydraulic accumulator is connected to a second control valve, which is connected to a first control valve, and the first control valve is connected to a parking actuator. The electrical control section includes an electronic controller and a parking switch; the electronic controller is electrically connected to an angle sensor, a speed pedal, an indicator light, a control unit, and the second control valve; the control unit includes a control section and an execution section, the control section of the control unit is electrically connected to the electronic controller, and the output of the execution section of the control unit is electrically connected to the first control valve; the parking switch is electrically connected between the indicator light and the input of the execution section of the control unit. This invention achieves automatic parking when the forklift is on a ramp, with stable and reliable control, improving driver safety on ramps, reducing driving risks, and minimizing accidents when the forklift is on a ramp.

Description

Technical Field

[0001] This invention relates to the field of forklift control system technology, specifically to an automatic parking control system and method for forklifts on ramps. Background Technology

[0002] Forklifts are mobile machines used in factories, docks, or storage yards. Forklifts generally have two braking systems: a service brake to slow down or stop the vehicle, and a parking brake to ensure the vehicle is reliably stationary.

[0003] Chinese patent discloses an automatically controlled hydraulic braking system for forklifts (CN217230137U), including a hydraulic oil tank and an oil pump. The oil pump's suction port is connected to the hydraulic oil tank. The oil pump's outlet is connected to the inlet of a two-position two-way solenoid valve and the inlet of a check valve. The outlet of the two-position two-way solenoid valve is connected to the hydraulic oil tank. The outlet of the check valve is connected to the inlet of a two-position three-way solenoid directional valve and an accumulator. The working port of the two-position three-way solenoid directional valve is connected to a parking brake. The outlet of the two-position three-way solenoid directional valve is connected to the hydraulic oil tank.

[0004] The shortcomings of the existing technology are: when a forklift is heavily loaded and going uphill, due to its large inertia, if the driver does not operate in time, the forklift is prone to slipping, which brings great safety hazards. Therefore, driving a forklift on a slope, especially under heavy load, requires a high level of driving skill from the driver. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides an automatic parking control system and method for forklift ramps.

[0006] This invention is achieved through the following technical solution: an automatic parking control system for forklift ramps.

[0007] Includes brake discs for braking forklifts and parking actuators for controlling the brake discs;

[0008] It also includes hydraulic control and electrical control components;

[0009] The hydraulic control section includes a hydraulic accumulator; the hydraulic accumulator is connected to a second control valve via a pipeline, the second control valve is connected to a first control valve via a pipeline, and the first control valve is connected to the parking actuator via a pipeline.

[0010] The electronic control unit includes an electronic controller and a parking switch; the electronic controller is electrically connected to an angle sensor, a speed pedal, an indicator light, and a control unit, and is also electrically connected to the second control valve;

[0011] The angle sensor is used to detect the pitch angle information of the forklift and transmit the pitch angle information to the electronic controller;

[0012] The speed pedal is used to input throttle signals to the forklift's engine and transmit the speed pedal's action information to the electronic controller;

[0013] The control unit includes a control section and an execution section. The control section of the control unit is electrically connected to the electronic controller, and the output of the execution section of the control unit is electrically connected to the first control valve.

[0014] The parking switch is electrically connected between the indicator light and the input terminal of the actuator of the control unit; when the parking switch is in the first position, the parking switch is electrically connected to the actuator of the control unit and disconnected from the indicator light; when the parking switch is in the second position, the parking switch is disconnected from the actuator of the control unit and connected to the indicator light.

[0015] Furthermore, the angle sensor is a horizontal sensor or a slope sensor.

[0016] The parking actuator is a pressure-relief spring brake.

[0017] The control unit is a relay, the control part is a relay control coil, and the execution part is a relay normally closed contact.

[0018] The electronic controller is a PLC controller or a controller specifically for mobile vehicles.

[0019] The first control valve has a drive coil; when the drive coil of the first control valve is energized, the left position of the first control valve is activated, and oil flows into the parking actuator through the first control valve; when the drive coil of the first control valve is de-energized, the right position of the first control valve is activated, and oil flows out of the parking actuator through the first control valve.

[0020] The second control valve has a drive coil; when the drive coil of the second control valve is energized, the right position of the second control valve is activated, and oil is prohibited from entering the first control valve through the second control valve; when the drive coil of the second control valve is de-energized, the left position of the second control valve is activated, and oil is allowed to flow through the second control valve to the first control valve.

[0021] An automatic parking control method for forklifts on ramps includes the following steps:

[0022] When the forklift is going uphill and the parking switch is in the first position

[0023] If the driver releases the accelerator pedal, the electronic controller detects that the accelerator pedal signal is zero, and the electronic controller determines that the pitch angle information of the angle sensor is within the preset threshold range. Then the electronic controller outputs a control signal, and the control unit of the second control valve and the control unit are energized simultaneously.

[0024] When the second control valve is energized, the brake fluid cannot pass through the second control valve;

[0025] When the control unit is energized, the actuator is disconnected and the first control valve is de-energized. After the first control valve is de-energized, the brake fluid in the parking actuator flows out through the first control valve to relieve pressure, and the parking actuator contacts the brake disc under the action of the internal spring to achieve braking.

[0026] At this time, the electronic controller outputs a signal to illuminate the indicator light, indicating that the forklift is in the parking state.

[0027] Furthermore, the threshold range of the pitch angle information of the angle sensor in the electronic controller is 3° to 20°.

[0028] Compared with the prior art, the beneficial effects of the present invention are: the present invention realizes the automatic parking function when the forklift goes uphill, the control method is stable and reliable, improves the safety of the driver when driving the forklift on the slope, reduces the driving risk, and can reduce the occurrence of accidents when the forklift goes uphill. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of an automatic parking control system for forklifts on ramps according to the present invention.

[0030] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0031] Figure 3 This is a control flowchart of an automatic parking control method for forklifts on ramps according to the present invention.

[0032] In the diagram: 1. Brake disc; 2. Parking actuator; 3. Hydraulic accumulator; 4. Second control valve; 5. First control valve; 6. Electronic controller; 7. Parking switch; 8. Indicator light; 9. Control unit; 91. Control section; 92. Actuator section; 10. Angle sensor; 11. Speed ​​pedal. Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0034] Combination Figure 1 , Figure 2 and Figure 3As shown, an automatic parking control system for a forklift ramp includes a brake disc 1 mounted on the chassis drive shaft of the forklift, and a parking actuator 2 that is contactably mounted on the brake disc 1. The parking actuator 2 is a pressure-release spring brake. When the forklift is braking, the parking actuator 2 contacts the brake disc 1 to control the braking of the forklift by the brake disc 1; when the forklift is not braking, the parking actuator 2 does not contact the brake disc 1.

[0035] An automatic parking control system for forklift ramps mainly includes a hydraulic control component and an electronic control component;

[0036] The hydraulic control system includes a hydraulic accumulator 3. The hydraulic accumulator 3 is connected to a second control valve 4 via a pipeline. The second control valve 4 is connected to a first control valve 5 via a pipeline. The first control valve 5 is connected to the parking actuator 2 via a pipeline. A check valve is installed in the pipeline between the hydraulic accumulator 3 and the second control valve 4. The hydraulic accumulator 3 is connected to the hydraulic system to ensure sufficient oil pressure within it. The hydraulic accumulator 3 provides power to the parking brake, i.e., drives the brake fluid flow.

[0037] In this embodiment, the first control valve 5 is equipped with a drive coil. When the drive coil of the first control valve 5 is energized, the left position of the first control valve 5 is activated, and oil from the second control valve 4 can flow into the parking actuator 2 through the first control valve 5. When the drive coil of the first control valve 5 is de-energized, the right position of the first control valve 5 is activated, and oil flows out of the parking actuator 2 through the first control valve 5 and enters the oil tank.

[0038] In this embodiment, the second control valve 4 is equipped with a drive coil. When the drive coil of the second control valve 4 is energized, the right-hand position of the second control valve 4 is activated, and oil is prevented from entering the first control valve 5 through the second control valve 4. When the drive coil of the second control valve 4 is de-energized, the left-hand position of the second control valve 4 is activated, and oil is allowed to flow through the second control valve 4 to the first control valve 5.

[0039] An electronic control component of an automatic parking control system for forklifts on ramps includes an electronic controller 6 and a parking switch 7. The electronic controller 6 is a PLC controller or a dedicated controller for mobile vehicles. The electronic controller 6 is electrically connected to an angle sensor 10, a speed pedal 11, an indicator light 8, a control unit 9, and a second control valve 4. The angle sensor 10 is a level sensor or a ramp sensor, used to detect the vehicle's angle in the horizontal direction, i.e., the vehicle's pitch angle, and transmits this pitch angle information to the electronic controller 6. The speed pedal 11 is used to input a throttle signal to the forklift's engine and transmits the speed pedal's action information to the electronic controller 6. After acquiring the signals, the electronic controller 6 makes a judgment based on the signal values ​​and outputs control signals to the second control valve and the control unit.

[0040] The control unit 9 is a relay, including a control unit 91 and an execution unit 92. The control unit 91 is a relay control coil, and the execution unit 92 is a normally closed contact of the relay. The control unit 91 of the control unit 9 is electrically connected to the electronic controller 6, and the output terminal of the execution unit 92 of the control unit 9 is electrically connected to the first control valve 5.

[0041] The parking switch 7 is electrically connected between the indicator light 8 and the input terminal of the actuator 92 of the control unit 9. When the indicator light 8 is illuminated, the forklift is in a parked state; when it is off, the forklift is in a non-parked state. The parking switch 7 has two positions. When the parking switch 7 is in the first position, it is electrically connected to the actuator 92 of the control unit 9, and disconnected from the indicator light 8. When the parking switch 7 is in the second position, it is disconnected from the actuator 92 of the control unit 9, and connected to the indicator light 8. Example

[0042] Based on the above embodiment one, a method for automatic parking control of forklift ramps includes the following steps:

[0043] When the forklift is parked on level ground;

[0044] When the parking switch 7 is in the open state, i.e., the second position, the parking switch 7 and the actuator 92 of the control unit 9 are not electrically connected. At this time, the coil of the first control valve 5 is de-energized and the first control valve 5 is in the right position. The brake fluid in the parking actuator 2 flows out through the right position of the first control valve 5 to relieve pressure. The parking actuator 2 contacts the brake disc 1 under the action of the internal spring to achieve braking.

[0045] Angle sensor 10 detects the horizontal angle of the vehicle in real time and sends the angle detection signal to electronic controller 6. Since the forklift is on flat ground, electronic controller 6 determines that the angle signal value is not within the preset threshold range (in this embodiment, the preset threshold range of the angle signal corresponds to an angle of 3° to 20°). Electronic controller 6 does not send an output signal. Therefore, the control unit 91 of control unit 9 and the coil of second control valve 4 are not energized. At this time, second control valve 4 is in the left position.

[0046] The parking switch 7 and indicator light 8 are electrically connected at this time. When indicator light 8 is lit, it means that the forklift is currently in the parking state.

[0047] When a forklift is traveling on level ground;

[0048] The parking switch 7 is in the unopened state, i.e., the first position. The parking switch 7 is electrically connected to the actuator 92. The coil of the first control valve 5 is energized and the first control valve 5 is working in the left position. The angle sensor 10 detects the horizontal angle of the vehicle and sends the angle detection signal to the electronic controller 6. The electronic controller 6 determines that the angle signal value is not within the preset threshold range. At this time, the electronic controller 6 does not need to make a judgment based on the signal from the speed pedal 11. The electronic controller 6 does not issue a control signal. The coil of the second control valve 4 and the control unit 91 of the control unit 9 are both de-energized. The second control valve 4 is working in the left position. The brake fluid enters the parking actuator 2 through the second control valve 4 and the first control valve 5 in sequence. The brake fluid pressure is balanced with the spring force in the parking actuator 2, causing the parking actuator 2 to leave the brake disc 1. The forklift is in the non-parking state.

[0049] In this situation, the electronic controller 6 does not send a signal to the indicator light 8 and the parking switch 7 is not electrically connected to the indicator light 8, so the indicator light 8 does not light up.

[0050] When a forklift is driving on a ramp;

[0051] When the forklift drives up the ramp, the parking switch 7 is in the inactive state (first position), and the parking switch 7 is electrically connected to the actuator 92. The coil of the first control valve 5 is energized, and the first control valve 5 is in the left position. The angle sensor 10 detects the horizontal angle of the vehicle and sends the angle detection signal to the electronic controller 6. The electronic controller 6 determines that the angle signal value is within a preset threshold range. The electronic controller 6 detects that the speed pedal 11 signal value is greater than zero. At this time, the electronic controller 6 does not issue a control signal. The coil of the second control valve 4 and the control unit 91 of the control unit 9 are both de-energized. The second control valve 4 is in the left position, and the forklift is in a non-parking state.

[0052] In this situation, the electronic controller 6 does not send a signal to the indicator light 8 and the parking switch 7 is not electrically connected to the indicator light 8, so the indicator light 8 does not light up.

[0053] When parking a forklift on a ramp;

[0054] When the forklift is on an uphill slope, the parking switch 7 is still in the non-open state (first position). The driver releases the speed pedal 11, and the electronic controller 6 detects that the speed pedal 11 signal is zero. The electronic controller 6 also determines that the angle signal value of the forklift on the slope is within the preset threshold range. The electronic controller 6 outputs a control signal, and the control unit 91 of the second control valve 4 and the control unit 9 are energized simultaneously. The second control valve 4 operates in the right position under the action of the coil, preventing the brake fluid from passing through the second control valve 4. Meanwhile, the control unit 91 of the control unit 9 is energized, causing the actuator 92 to disconnect. The first control valve 5 is de-energized and operates in the right position. The brake fluid in the parking actuator 2 flows out through the right position of the first control valve to achieve pressure relief. The parking actuator 2 contacts the brake disc 1 under the action of the internal spring to achieve braking.

[0055] The electronic controller 6 outputs a signal to control indicator light 8 to illuminate, indicating that the forklift is in the parking state.

[0056] When the forklift is going downhill;

[0057] Release the speed pedal 11, but the angle sensor 10 detects a negative angle signal at this time, which does not fall within the preset threshold angle range. Therefore, the forklift can still drive and does not implement automatic parking.

[0058] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, 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.

Claims

1. A forklift ramp automatic parking control system, comprising a brake disc (1) for braking the forklift and a parking actuator (2) for controlling the brake disc (1); characterized in that: it further comprises a hydraulic control part and an electric control part; the hydraulic control part comprises a hydraulic accumulator (3), the hydraulic accumulator (3) is connected with a second control valve (4) through a pipeline, the second control valve (4) is connected with a first control valve (5) through a pipeline, and the first control valve (5) is connected with the parking actuator (2) through a pipeline; the electric control part comprises an electronic controller (6) and a parking switch (7), the electronic controller (6) is electrically connected with an angle sensor (10), a speed pedal (11), an indicator light (8) and a control unit (9), and the electronic controller (6) is further electrically connected to the second control valve (4); the angle sensor (10) is used for detecting the pitch angle information of the forklift and transmitting the pitch angle information to the electronic controller (6); the speed pedal (11) is used for inputting a throttle signal to the engine of the forklift and transmitting the action information of the speed pedal (11) to the electronic controller (6); the control unit (9) comprises a control part (91) and an execution part (92), the control part (91) of the control unit (9) is electrically connected with the electronic controller (6), and the output end of the execution part (92) of the control unit (9) is electrically connected with the first control valve (5); the parking switch (7) is electrically connected between the indicator light (8) and the input end of the execution part (92) of the control unit (9); when the parking switch (7) is in the first position, the parking switch (7) is electrically connected with the execution part (92) of the control unit (9), and the parking switch (7) is disconnected with the indicator light (8); when the parking switch (7) is in the second position, the parking switch (7) is disconnected with the execution part (92) of the control unit (9), and the parking switch (7) is electrically connected with the indicator light (8).

2. The automatic hill hold control system for a forklift truck according to claim 1, characterized by: The angle sensor (10) is a level sensor or a ramp sensor.

3. The automatic hill hold control system for a forklift truck of claim 1, wherein: The parking actuator (2) is a pressure release spring brake.

4. The automatic hill hold control system for a forklift truck of claim 1, wherein: The control unit (9) is a relay, the control part (91) is a relay control coil, and the execution part (92) is a relay normally closed contact.

5. The automatic hill hold control system for a forklift truck of claim 1, wherein: The electronic controller (6) is a PLC controller or a mobile vehicle special controller.

6. The automatic hill hold control system for a forklift truck of claim 1, wherein: The first control valve (5) has a driving coil; when the driving coil of the first control valve (5) is powered, the left side of the first control valve (5) is activated, and the oil flows into the parking actuator (2) through the first control valve (5); when the driving coil of the first control valve (5) loses power, the right side of the first control valve (5) is activated, and the oil flows out of the parking actuator (2) through the first control valve (5).

7. The automatic hill hold control system for a forklift truck of claim 1, wherein: The second control valve (4) has a drive coil; when the drive coil of the second control valve (4) is electrified, the right side of the second control valve (4) is activated, and the oil is prohibited from entering the first control valve (5) through the second control valve (4); when the drive coil of the second control valve (4) is de-energized, the left side of the second control valve (4) is activated, and the oil is allowed to flow to the first control valve (5) through the second control valve (4).

8. A method for controlling automatic hill hold of a forklift truck, using the automatic hill hold control system for a forklift truck according to any one of claims 1 to 7, characterized by, The method comprises the following steps: When the forklift is on the ramp and the parking switch (7) is in the first position; If the driver releases the speed pedal (11), the electronic controller (6) detects that the speed pedal (11) signal is equal to zero, and the electronic controller (6) judges that the value of the pitch angle information of the angle sensor (10) at this time is in the preset threshold range, then the electronic controller (6) outputs a control signal, and the second control valve (4) and the control part (91) of the control unit (9) are electrified at the same time; After the second control valve (4) is electrified, the brake oil cannot pass through the second control valve (4); After the control part (91) of the control unit (9) is electrified, the execution part (92) is disconnected, and the first control valve (5) is de-energized; after the first control valve (5) is de-energized, the brake oil in the parking actuator (2) flows out through the first control valve (5) to achieve pressure relief, and the parking actuator (2) contacts the brake disc (1) under the action of the internal spring to achieve braking; At this time, the electronic controller (6) outputs a signal to control the indicator light (8) to turn on, indicating that the forklift is in the parking state.

9. The method of claim 8, wherein: The threshold range of the pitch angle information of the angle sensor (10) in the electronic controller (6) is 3° to 20°.

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