Brake control system and method for diesel fork lift truck

Abstract

The invention discloses a diesel fork lift truck braking control system which comprises a power supply part used for providing a power source, a gear switch used for controlling the gear of a fork lift truck, a controller, a braking part, a seat switch and a truck speed sensor. The brake part comprises a parking brake valve, a parking brake switch and a brake pressure low switch; the controller is in signal communication with the gear switch, the parking brake switch, the brake pressure low switch, the seat switch and the vehicle speed sensor, the state of the forklift is obtained by detecting the gear, the parking brake switch state and the brake pressure state of the forklift, and when a vehicle runs and parking brake is not released, the parking brake low switch is switched on or switched off. The system can give an alarm and control the forklift not to run until the parking brake is released, so that the forklift can run normally, and the situation that the forklift runs with the brake is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of forklift braking, and in particular to a braking control system and method for an internal combustion forklift. Background Art

[0002] The electronic parking brake on an internal combustion forklift achieves braking by compressing the brake friction disc with mechanical spring force. Electronic control effectively and timely controls the opening of the solenoid valve and oil circuit. Releasing the electronic parking brake button directly controls the parking solenoid valve. When the solenoid valve is energized, transmission oil fills the parking brake. Pressure builds in the brake oil chamber to overcome the spring force acting on the friction plate, releasing the parking brake.

[0003] Compared to traditional handbrakes, electronic parking brakes are easier to operate, require less effort, and require less space. However, due to the small size of the parking brake switch, many drivers overlook it and often forget to release it. Furthermore, the parking brake switch on internal combustion forklifts must be capable of unexpected release, and cannot use a self-resetting parking brake switch like that used in automobiles. This can also result in the controller de-energizing the forward or reverse solenoid valves if the parking brake switch is not released or brake pressure is low, leaving the vehicle in neutral. Summary of the Invention

[0004] The object of the present invention is to provide a braking control system and method for an internal combustion forklift to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A braking control system for an internal combustion forklift, comprising a power supply unit for providing power, a gear switch for controlling the gear position of the forklift, a controller, a braking unit, a seat switch, and a vehicle speed sensor;

[0007] The braking unit includes a parking brake valve, a parking brake switch, and a low brake pressure switch;

[0008] The controller is in signal communication with the gear switch, parking brake switch, low brake pressure switch, seat switch, and vehicle speed sensor.

[0009] As a further solution of the present invention: the power supply unit includes a power supply and a start switch and a fuse connected to the power supply, and the gear switch includes a forward gear, a reverse gear, and a neutral gear.

[0010] As a further solution of the present invention: a second power processing module, a second CAN transceiver, and a single-chip microcomputer are provided in the controller.

[0011] As a further solution of the present invention: the controller signal is connected to the instrument panel, the instrument panel is connected to the gear switch and vehicle speed sensor signal, the instrument panel is provided with a display screen, and the instrument panel is provided with a first power processing module and a first CAN transceiver.

[0012] As a further solution of the present invention: the controller signal is connected to the engine controller, a third CAN transceiver is provided in the engine controller, and the engine controller is signal-connected to the second CAN transceiver in the controller through the third CAN transceiver.

[0013] As a further solution of the present invention: a first relay is provided in the controller, the first relay is electrically connected to the parking brake valve, and the first relay is signal-connected to the single-chip microcomputer.

[0014] As a further solution of the present invention: the single chip computer signal is connected to a second relay and a third relay, the second relay is connected to a forward valve, the third relay is connected to a reverse valve, and the forward valve and reverse valve are arranged in the forklift gearbox to control the forklift to move forward and backward.

[0015] A braking control method for an internal combustion forklift, comprising the following steps:

[0016] S1, forklift power on self-test;

[0017] S2, start the forklift;

[0018] S3: Detection of the forklift driver's position, gear position, and brake status. If the forklift driver leaves the driving position, the forklift cannot move. If the forklift is in the forward or reverse gear and is in the braking state, an alarm will be issued to remind the driver to release the forklift brake.

[0019] S4. Detect the throttle status of the forklift. If the driver steps on the throttle, detect the brake status of the forklift. If the parking brake is not released, release the parking brake.

[0020] S5. During the driving process, the forklift parking brake switch and the low brake pressure switch are detected. If the parking brake switch is detected to be triggered, the forklift does not brake. If the low brake pressure switch is triggered, the oil pressure of the parking brake valve decreases, and the oil supply to the parking brake valve is cut off, the forklift stops, and the parking brake is activated.

[0021] As a further solution of the present invention: S1 comprises the following steps:

[0022] S1.1. The forklift's start switch is closed to position N, and the forklift's instruments, controllers, and engine controller are powered;

[0023] S1.2, the gear switch is in neutral. After the instrument receives the neutral signal, the neutral indicator light will light up to remind the driver that the forklift is in neutral, and the neutral signal will be uploaded to the vehicle CAN bus;

[0024] S1.3. The driver sits in the seat, the seat switch is closed, and the controller detects that the driver is safely seated. It converts the detected seat signal into a bus signal and uploads it to the vehicle CAN bus. The vehicle speed sensor outputs to the vehicle CAN bus.

[0025] S1.4. The instrument panel reads the seat signal on the CAN bus and detects that the driver has sat correctly in the seat. The seat indicator light goes off. If the driver has not sat correctly in the seat, the seat indicator light comes on. If the driver has not sat correctly in the seat for more than 1.5 seconds, a text reminder alarm will be displayed on the instrument panel LCD screen.

[0026] As a further solution of the present invention: in said S3, the instrument detects the neutral signal and the parking brake signal simultaneously. If the gear switch is in neutral and the parking brake switch is pulled, no alarm is given. If it is detected that the gear switch is not in neutral and the parking brake switch is not released, the instrument alarm is given and a reminder "Please release the parking brake" is given.

[0027] When the controller detects that a person has left the seat and the switch is disconnected for more than 1.5 seconds, the controller controls the forklift to lock and cannot move;

[0028] When the controller detects that the seat switch is disconnected for more than 1.5 seconds and then closed, if the gear switch is in the forward gear or reverse gear, the controller controls the forklift to lock and cannot move; if the gear switch returns to neutral and then to the forward gear or reverse gear, the controller can control the forklift to lock the contact and the forklift can move forward or reverse.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. This application obtains the forklift status by detecting the forklift's gear position, parking brake switch status, and brake pressure status. When the vehicle is moving and the parking brake is not released, this application system will issue an alarm and control the forklift to be unable to move until the parking brake is released. This avoids the situation where the forklift is driving with the brakes on.

[0031] 2. This application detects the brake pressure status. Since the forklift uses the hydraulic system to provide hydraulic oil to pull the piston and resist the parking brake spring to release the parking brake, when the oil supply pressure is insufficient, the parking brake will generate a certain braking force under the action of the spring. If the forklift is in a driving state at this time, it will cause the parking brake to wear out quickly. This application can detect the brake oil pressure and promptly issue an alarm and cut off the brake oil supply in time when the brake oil pressure is insufficient, so that the forklift stops and is in a braking state, avoiding rapid wear of the brake caused by the forklift driving;

[0032] 3. This application states that if the parking brake switch is accidentally touched during the driving of the forklift, the parking brake of the forklift will not be affected, thus avoiding damage to the forklift caused by accidental touching of the parking brake;

[0033] 4. This application is provided with a seat switch, by which it is possible to determine whether the driver is in the driving position. When the forklift driver is not in the driving position, the brakes will not be released, avoiding dangerous situations such as the forklift sliding down a slope due to mis-release of the brakes. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the circuit diagram of the system for this implementation;

[0035] In the figure: 1-power supply, 2-start switch, 3-fuse, 4-gear switch, 5-instrument, 6-controller, 7-parking brake solenoid valve, 8-parking brake switch, 9-low brake pressure switch, 10-seat switch, 11-engine controller, 12-first power processing module, 13-first CAN transceiver, 14-display, 15-second power processing module, 16-speed sensor, 17-second CAN transceiver, 18-single-chip microcomputer, 19-first relay, 20-third CAN transceiver, 21-forward valve, 22-reverse valve, 23-second relay, 24-third relay. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] See also Figure 1In an embodiment of the present invention, a braking control system for an internal combustion forklift includes a power supply unit, a gear switch 4, an instrument 5, a controller 6, a braking unit, a seat switch 10, and a vehicle speed sensor 16. The controller 6 is in signal communication with the gear switch 4, the parking brake switch 8, the low brake pressure switch 9, the seat switch 10, and the vehicle speed sensor 16.

[0038] The power supply unit includes: a power supply for providing power to the entire control system; a start switch 2 for supplying power to and starting the entire machine, which is divided into the power-on Acc gear and the start Star gear; and a fuse 3 for overcurrent protection, which is used to protect electrical equipment.

[0039] The gear switch 4 includes a forward gear, a reverse gear, and a neutral gear.

[0040] The instrument 5 and the controller 6 are connected to the instrument panel 5 by signal. The instrument panel 5 is connected to the gear switch 4 and the vehicle speed sensor 16 by signal. A display screen 14 is provided on the instrument panel 5. A first power processing module 12 and a first CAN transceiver 13 are provided in the instrument panel 5. The instrument 5 is used for parking brake signal collection, CAN bus signal uploading and CAN bus signal reception, and indicator light lighting or extinguishing control.

[0041] The vehicle controller 6VCU is used to control the operation of the vehicle brake valve. The controller 6 is equipped with a second power processing module 15, a second CAN transceiver 17, and a single-chip microcomputer 18. The controller 6 is signal-connected to the engine controller 11. The engine controller 11 is equipped with a third CAN transceiver 20. The engine controller 11 is signal-connected to the second CAN transceiver 17 in the controller 6 through the third CAN transceiver 20.

[0042] A first relay 19 is provided in the controller 6, and the first relay 19 is electrically connected to the parking brake valve 7. The first relay 19 is in signal communication with the single-chip computer 18, and the single-chip computer 18 is in signal communication with a second relay 23 and a third relay 24. The second relay 23 is connected to the forward valve 21, and the third relay 24 is connected to the reverse valve 22. The forward valve 21 and the reverse valve 22 are provided in the forklift gearbox for controlling the forklift to move forward and backward.

[0043] The braking unit includes a parking brake valve 7, a parking brake switch 8, and a low brake pressure switch 9. The parking brake valve 7 is installed on the gearbox and controls the opening and closing of the solenoid valve oil circuit. When the solenoid valve is energized, the transmission oil fills the parking brake, and the brake oil chamber generates pressure to overcome the spring force acting on the friction plate, thereby releasing the parking brake. The parking brake switch 8 is used to provide resistance to the forklift when it is parked, so that the forklift does not slide down the slope and can be parked steadily. The low brake pressure switch 9 detects the pressure of the brake system. When the controller detects low brake pressure, it can switch related circuits to improve driving safety.

[0044] The seat switch 10 detects in real time whether the driver is sitting correctly in the seat and controls the forklift's movement, parking, lifting and other actions according to the driver's status to ensure safe driving or operation of the forklift.

[0045] CAN transceiver 13, CAN transceiver 17, CAN transceiver 20 upload and receive data between the instrument, controller and engine controller ECU in real time, and communicate with each other.

[0046] A braking control method for an internal combustion forklift, comprising the following steps:

[0047] S1, forklift power on self-test;

[0048] S1 includes the following steps:

[0049] S1.1. Close the forklift's start switch 2 to the 0N position, and the forklift's instrument 5, controller 6, and engine controller 11 are powered;

[0050] S1.2, the gear switch 4 is in neutral. After receiving the neutral signal, the instrument 5 lights up the neutral indicator to remind the driver that the forklift is in neutral, and uploads the neutral signal to the vehicle CAN bus;

[0051] S1.3. The driver sits in the seat, and the seat switch 10 is closed. The controller 6 detects that the driver is safely seated and converts the detected seat signal into a bus signal and uploads it to the vehicle CAN bus. The vehicle speed sensor 16 also outputs the signal to the vehicle CAN bus.

[0052] S1.4: Instrument 5 reads the seat signal on the CAN bus and detects that the driver is correctly seated in the seat. The seat indicator light turns off. If the driver is not correctly seated in the seat, the seat indicator light turns on. If the driver still does not sit properly in the seat for more than 1.5 seconds, a text reminder alarm is displayed on the instrument LCD screen.

[0053] also,

[0054] When the parking brake switch 8 is closed, the instrument detects the parking brake closing signal, lights up the parking brake indicator light, converts the detected signal into a CAN signal and uploads it to the vehicle CAN bus;

[0055] When the low brake pressure switch 9 is closed, the vehicle controller converts the low brake pressure signal into a CAN bus signal and uploads it to the vehicle CAN bus;

[0056] Instrument 5 reads the low brake pressure bus signal on the vehicle and lights up the low brake pressure indicator light when low brake pressure is detected;

[0057] S2, start the forklift;

[0058] S3: Detection of the forklift driver's position, gear position, and brake status. If the forklift driver leaves the driving position, the forklift cannot move. If the forklift is in the forward or reverse gear and is in the braking state, an alarm will be issued to remind the driver to release the forklift brake.

[0059] In this embodiment, the instrument detects both the neutral signal and the parking brake signal. If the forward signal F or the reverse signal R of the gear switch 4 is not closed, the gear switch is in the neutral position N, and the parking brake switch 8 is pulled, no alarm will be given. If the gear switch 4 is detected to be in a non-neutral position (forward or reverse) and the parking brake switch 8 is not released, the instrument 5 will give an alarm and remind "Please release the parking brake". If the parking brake has been released at this time, a "low brake pressure" reminder will be given.

[0060] When the controller 6 detects that the person has left the seat and the switch 10 is disconnected for more than 1.5 seconds, the single-chip microcomputer 18 in the controller 6 no longer outputs the control relay 23 or 24, and the transmission cannot move forward or reverse at this time. When the controller 6 detects that the seat switch 10 is closed, but the controller 6 detects that the gear switch 4 is in forward gear F or reverse gear R, the controller 6 also does not output the second relay 23 or relay 24, and the transmission is also in neutral at this time. Only when the controller 6 detects that the gear switch 4 returns to neutral gear N and then to forward gear F or reverse gear R, the single-chip microcomputer 18 in the controller 6 outputs the control relay 23 or relay 24, and the transmission can move forward or reverse.

[0061] S4. Detecting the throttle status of the forklift. If the driver steps on the accelerator of the forklift, the engine controller 11 is energized and uploads the throttle signal and engine speed signal of the CAN bus. Detecting the braking status of the forklift, the controller 6 detects that the parking brake switch 8 is disconnected, and the single-chip microcomputer 18 in the controller 6 controls the output of the first relay 19 to be energized, thereby controlling the parking brake valve to be energized and oil to be supplied, thereby releasing the brake disc. If the controller 6 detects that the gear switch 4 is in the forward gear F or the reverse gear R, and the controller detects that the throttle opening on the CAN bus of the entire machine is not 0, the single-chip microcomputer 18 in the controller 6 controls the output of the first relay 19 to be energized, thereby controlling the parking brake valve to be energized and oil to be supplied, thereby releasing the brake disc.

[0062] S5: The forklift is driving. During driving, the parking brake switch 8 and the low brake pressure switch 9 are detected. If the parking brake switch 8 is detected to be triggered, the forklift does not brake. If the low brake pressure switch 9 is triggered, the oil pressure of the parking brake valve decreases, and the oil supply to the parking brake valve is cut off, the forklift stops, and the parking brake is activated.

[0063] In this embodiment, when the controller 6 detects that the brake pressure is low after the brake valve is energized, the single chip microcomputer 18 in the controller 6 controls the output of the first relay 19 to be de-energized, controls the parking brake valve to stop supplying oil, and the brake disc is locked;

[0064] The controller detects that the gear switch 4 is in the forward gear F or the reverse gear R, and at the same time detects that the vehicle speed is not 0, the parking brake switch 8 changes from open to closed, the single chip microcomputer 18 in the controller 6 controls the output first relay 19 to be continuously energized and must not be de-energized, controls the parking brake valve to be energized and oil supplied, and the brake disc is released.

[0065] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0066] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A braking control system for an internal combustion forklift, characterized in that: It includes a power supply unit for providing power, a gear switch (4) for controlling the gear position of the forklift, a controller (6), a brake unit, a seat switch (10), and a vehicle speed sensor (16); The braking unit includes a parking brake valve (7), a parking brake switch (8), and a low brake pressure switch (9); The controller (6) is in signal communication with the gear switch (4), the parking brake switch (8), the low brake pressure switch (9), the seat switch (10), and the vehicle speed sensor (16).

2. The internal combustion forklift brake control system according to claim 1, characterized in that: The power supply unit includes a power supply (1), a start switch (2) and a fuse (3) connected to the power supply (1), and the gear switch (4) includes a forward gear, a reverse gear, and a neutral gear.

3. The internal combustion forklift brake control system according to claim 1, characterized in that: The controller (6) is provided with a second power processing module (15), a second CAN transceiver (17), and a single chip microcomputer (18).

4. The internal combustion forklift brake control system according to claim 3, characterized in that: The controller (6) is signal-connected to an instrument panel (5), and the instrument panel (5) is signal-connected to the gear switch (4) and the vehicle speed sensor (16). A display screen (14) is provided on the instrument panel (5), and a first power processing module (12) and a first CAN transceiver (13) are provided in the instrument panel (5).

5. The internal combustion forklift brake control system according to claim 3, characterized in that: The controller (6) is signal-connected to an engine controller (11), a third CAN transceiver (20) is provided in the engine controller (11), and the engine controller (11) is signal-connected to a second CAN transceiver (17) in the controller (6) via the third CAN transceiver (20).

6. The internal combustion forklift brake control system according to claim 3, characterized in that: A first relay (19) is provided in the controller (6), the first relay (19) is electrically connected to the parking brake valve (7), and the first relay (19) is signal-connected to the single-chip microcomputer (18).

7. The internal combustion forklift brake control system according to claim 3, characterized in that: The single chip computer (18) is connected to a second relay (23) and a third relay (24) via a signal; the second relay (23) is connected to a forward valve (21); the third relay (24) is connected to a reverse valve (22); the forward valve (21) and the reverse valve (22) are arranged on the forklift gearbox to control the forklift to move forward and backward.

8. A method for controlling a brake of an internal combustion forklift using the brake control system according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, forklift power on self-test; S2, start the forklift; S3, forklift driver position detection, gear detection, and brake status detection. If the forklift driver leaves the driving position, the forklift cannot move; If the forklift is in forward or reverse gear and the forklift is in braking state, an alarm will sound to remind you to release the forklift brake; S4. Detect the throttle status of the forklift. If the driver steps on the throttle, detect the brake status of the forklift. If the parking brake is not released, release the parking brake. S5, the forklift is traveling. During the traveling process, the parking brake switch (8) and the low brake pressure switch (9) of the forklift are detected. If the parking brake switch (8) is detected to be triggered, the forklift does not brake. If the low brake pressure switch (9) is triggered, the oil pressure of the parking brake valve is reduced, and the oil supply to the parking brake valve of the forklift is cut off, the forklift stops, and the parking brake is activated.

9. The internal combustion forklift brake control method according to claim 8, characterized in that: Said S1 comprises the following steps: S1.

1. The start switch (2) of the forklift is closed to position (0)N, and the forklift's instrument (5), controller (6), and engine controller (11) are powered; S1.2, the gear switch (4) is in neutral, and after the instrument (5) receives the neutral signal, the neutral indicator light is turned on to remind the driver that the forklift is in neutral, and the neutral signal is uploaded to the vehicle CAN bus; S1.3, the driver sits on the seat, the seat switch (10) is closed, the controller (6) detects that the driver sits on the seat safely, and converts the detected seat signal into a bus signal and uploads it to the vehicle CAN bus; the vehicle speed sensor (16) outputs to the vehicle CAN bus; S1.4, the instrument (5) reads the seat signal on the CAN bus and detects that the driver is sitting on the seat correctly, then the seat indicator light goes out; if it detects that the driver is not sitting on the seat correctly, the seat indicator light is turned on. If the time is greater than 1.5 seconds and the driver has not sat on the seat correctly, a text reminder alarm is issued on the instrument LCD screen.

10. The internal combustion forklift brake control method according to claim 8, characterized in that: In said S3, the instrument (5) detects the neutral signal and the parking brake signal simultaneously. If the gear switch (4) is in neutral and the parking brake switch (8) is pulled up, no alarm is given. If it is detected that the gear switch (4) is not in neutral and the parking brake switch (8) is not released, the instrument (5) gives an alarm and reminds "Please release the parking brake"; When the controller (6) detects that the person has left the seat and the switch (10) is disconnected for more than 1.5 seconds, the controller (6) controls the forklift to be locked and unable to move; When the controller (6) detects that the seat switch (10) is disconnected for more than 1.5 seconds and then closed, if the gear switch (4) is in the forward gear or the reverse gear, the controller (6) controls the forklift to lock and cannot move; if the gear switch (4) returns to the neutral gear and then to the forward gear or reverse gear, the controller (6) can control the forklift to lock the contact and the forklift can move forward or backward.

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