Dual brake switch braking system for electric fork truck and fault detection method thereof

Abstract

The application discloses a kind of electric fork truck with double brake switch brake system and its fault detection method, including brake pedal mechanism, brake switch one, brake switch two, VCU controller, instrument and brake signal lamp, brake switch one obtains the trigger point of brake pedal signal in brake pedal mechanism is set at brake pedal at initial position, brake switch two obtains the trigger point of brake pedal signal in brake pedal mechanism is set at preset position in brake pedal stroke And the signal trigger point position of brake switch one is different.The application is provided with two groups of brake switches, can ensure that when one brake switch is damaged, the vehicle realizes effective braking, ensures safety, and utilizes two brake switch trigger positions, judges the working state of two brake switches according to motor feedback brake deceleration rate signal, so that maintenance personnel can judge fault type and position, and carry out rapid repair.

Description

Technical Field

[0001] This invention relates to the field of electric forklift technology, and in particular to a dual-brake switch braking system for electric forklifts and its fault detection method. Background Technology

[0002] Currently, the braking signals of electric forklifts all come from a single brake switch. If the brake switch is damaged and cannot output a braking signal, it will lead to brake failure, which can easily cause safety accidents.

[0003] The following issues need to be addressed:

[0004] 1) When there is a need for braking, a safety accident may occur because the brake switch is damaged and cannot output a braking signal.

[0005] 2) When there is no braking requirement, the brake switch is damaged and outputs a braking signal, causing the entire vehicle to brake suddenly. However, the electric forklift cannot provide timely feedback and alarm for this state. If this state continues to operate, it will easily lead to damage to goods and a reduction in operating efficiency. Summary of the Invention

[0006] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to provide a dual-brake switch braking system for electric forklifts and its fault detection method, ensuring effective braking of the entire vehicle and facilitating maintenance personnel to determine the type and location of faults for rapid repair.

[0007] According to the present invention, a dual-brake switch braking system for an electric forklift includes a brake pedal mechanism, a first brake switch, a second brake switch, a VCU controller, an instrument panel, and a brake indicator light. The trigger point for the first brake switch to acquire the brake pedal signal in the brake pedal mechanism is set at the initial position of the brake pedal. The trigger point for the second brake switch to acquire the brake pedal signal in the brake pedal mechanism is set at a preset position during the brake pedal travel, and is different from the trigger point of the first brake switch. The signal output terminals of the first and second brake switches are respectively connected to the signal input terminal of the VCU controller. The signal output terminal of the VCU controller is respectively connected to the signal input terminal of the instrument panel and the signal input terminal of the brake indicator light.

[0008] Preferably, a fault detection method for a dual-brake switch braking system for an electric forklift is provided. When the brake pedal travel is at the trigger point of brake switch one, the braking deceleration rate fed back to the VCU controller by the motor is B. When the brake pedal travel is at the trigger point of brake switch two, the braking deceleration rate fed back to the VCU controller by the motor is A. Braking deceleration rate A is greater than braking deceleration rate B. The fault detection method for the braking system during vehicle braking involves the following steps:

[0009] S1: The VCU controller receives the switch signals feedback from brake switch 1 and brake switch 2 and the brake deceleration rate signal a feedback from the motor. If the VCU controller receives that brake switch 1 is in the closed state and brake switch 2 is in the closed state, execute step S2; if the VCU controller receives that brake switch 1 is in the closed state and brake switch 2 is in the open state, execute step S6; if the VCU controller receives that brake switch 1 is in the open state and brake switch 2 is in the open state, execute step S10; if the VCU controller receives that brake switch 1 is in the open state and brake switch 2 is in the closed state, execute step S14;

[0010] S2: The VCU controller performs a comparison operation on the real-time detected brake deceleration rate signal a with the brake deceleration rates of A and B. If a = B, execute step S3; if B < a < A, execute step S4; if a ≥ A, execute step S5;

[0011] S3: The VCU controller outputs that both brake switch 1 and brake switch 2 are in abnormal working states, gives a fault prompt through the instrument, shuts down the whole vehicle, and enters the fault judgment mode;

[0012] S4: The VCU controller outputs that brake switch 1 is in the normal working state and brake switch 2 is in the abnormal working state, gives a fault prompt through the instrument, shuts down the whole vehicle, and enters the fault judgment mode;

[0013] S5: The VCU controller outputs that both brake switch 1 and brake switch 2 are in the normal working states, displays through the instrument, and the whole vehicle runs normally;

[0014] S6: The VCU controller performs a comparison operation on the real-time detected brake deceleration rate signal a with the brake deceleration rates of A and B. If a = B, execute step S7; if B < a < A, execute step S8; if a ≥ A, execute step S9;

[0015] S7: The VCU controller outputs that brake switch 1 is in the abnormal working state and brake switch 2 is in the normal working state, gives a fault prompt through the instrument, shuts down the whole vehicle, and enters the fault judgment mode;

[0016] S8: The VCU controller outputs that both brake switch 1 and brake switch 2 are in the normal working states, displays through the instrument, and the whole vehicle runs normally;

[0017] S9: The VCU controller outputs that brake switch 1 is in the normal working state and brake switch 2 is in the abnormal working state, gives a fault prompt through the instrument, shuts down the whole vehicle, and enters the fault judgment mode;

[0018] S10: The VCU controller performs a comparison operation on the braking deceleration signal a detected in real time with braking decelerations A and B. If a = B, step S11 is executed; if B < a < A, step S12 is executed; if a ≥ A, step S13 is executed;

[0019] S11: The VCU controller outputs that both brake switch one and brake switch two are in normal working states, which are displayed through the instrument, and the whole vehicle runs normally;

[0020] S12: The VCU controller outputs that brake switch one is in an abnormal working state and brake switch two is in a normal working state, gives a fault prompt through the instrument, the whole vehicle stops, and enters the fault judgment mode;

[0021] S13: The VCU controller outputs that both the working states of brake switch one and brake switch two are abnormal, gives a fault prompt through the instrument, the whole vehicle stops, and enters the fault judgment mode;

[0022] S14: The VCU controller performs a comparison operation on the braking deceleration signal a detected in real time with braking decelerations A and B. If a = B, step S15 is executed; if B < a < A, step S16 is executed; if a ≥ A, step S17 is executed;

[0023] S15: The VCU controller outputs that brake switch one is in a normal working state and brake switch two is in an abnormal working state, gives a fault prompt through the instrument, the whole vehicle stops, and enters the fault judgment mode;

[0024] S16: The VCU controller outputs that both the working states of brake switch one and brake switch two are abnormal, gives a fault prompt through the instrument, the whole vehicle stops, and enters the fault judgment mode;

[0025] S17: The VCU controller outputs that brake switch one is in an abnormal working state and brake switch two is in a normal working state, gives a fault prompt through the instrument, the whole vehicle stops, and enters the fault judgment mode.

[0026] Preferably, when the whole vehicle is in the braking process, both the brake signal lamp and the instrument brake signal indicator light are lit.

[0027] Preferably, when the whole vehicle starts to run, the working states of brake switch one and brake switch two are judged. At this time, brake switch one and brake switch two are in the initial untriggered state. When the initial states of brake switch one and brake switch two are abnormal, the whole vehicle cannot be used normally, and a fault prompt is given on the instrument; when the initial states of the brake switches are normal, deeply stepping on the brake pedal triggers brake switch one and brake switch two, and the working states of brake switch one and brake switch two are judged.

[0028] Preferably, when the vehicle is started, the vehicle will operate normally only if the working states of brake switch one and brake switch two are both normal.

[0029] The beneficial effects of this invention are as follows: by setting two sets of brake switches, it can be ensured that the whole vehicle can achieve effective braking when one brake switch fails, thus ensuring safety. Furthermore, by utilizing the different trigger positions of the two sets of brake switches, the working status of the two sets of brake switches can be determined based on the braking deceleration rate signal fed back by the motor. The VCU controller provides real-time feedback on the brake switch status through the instrument, which facilitates fault detection. At the same time, maintenance personnel can determine the fault type and location based on the information fed back by the instrument and carry out rapid repairs. Attached Figure Description

[0030] In the attached diagram:

[0031] Figure 1 This is a flowchart illustrating a fault detection method for a dual-brake switch braking system for electric forklifts during forklift operation, as proposed in this invention.

[0032] Figure 2 This is a flowchart of the fault detection method for a dual-brake switch braking system for electric forklifts proposed in this invention during forklift startup. Detailed Implementation

[0033] Reference Figure 1 A dual-brake switch braking system for an electric forklift includes a brake pedal mechanism, a first brake switch, a second brake switch, a VCU controller, an instrument panel, and brake indicator lights. The trigger point for the first brake switch to acquire the brake pedal signal in the brake pedal mechanism is set at the initial position of the brake pedal. The trigger point for the second brake switch to acquire the brake pedal signal in the brake pedal mechanism is set at a preset position during the brake pedal travel, and the trigger point is different from that of the first brake switch. The signal output terminals of the first and second brake switches are respectively connected to the signal input terminals of the VCU controller. The signal output terminals of the VCU controller are respectively connected to the signal input terminals of the instrument panel and the brake indicator lights.

[0034] A fault detection method for a dual-brake switch braking system in an electric forklift is provided. When the brake pedal travel is at the trigger point of brake switch one, the braking deceleration rate fed back to the VCU controller by the motor is B. When the brake pedal travel is at the trigger point of brake switch two, the braking deceleration rate fed back to the VCU controller by the motor is A. Braking deceleration rate A is greater than braking deceleration rate B. The fault detection method for the braking system during vehicle braking involves the following steps:

[0035] S1: The VCU controller receives the switch signals feedback from Brake Switch 1 and Brake Switch 2 and the braking deceleration signal a feedback from the motor. If the VCU controller receives that Brake Switch 1 is in the closed state and Brake Switch 2 is in the closed state, execute Step S2; if the VCU controller receives that Brake Switch 1 is in the closed state and Brake Switch 2 is in the open state, execute Step S6; if the VCU controller receives that Brake Switch 1 is in the open state and Brake Switch 2 is in the open state, execute Step S10; if the VCU controller receives that Brake Switch 1 is in the open state and Brake Switch 2 is in the closed state, execute Step S14;

[0036] S2: The VCU controller performs a comparison operation on the real-time detected braking deceleration signal a with braking decelerations A and B. If a = B, execute Step S3; if B < a < A, execute Step S4; if a ≥ A, execute Step S5;

[0037] S3: The VCU controller outputs that the working states of both Brake Switch 1 and Brake Switch 2 are abnormal, gives a fault prompt through the instrument panel, shuts down the whole vehicle, and enters the fault judgment mode;

[0038] S4: The VCU controller outputs that Brake Switch 1 is in the normal working state and Brake Switch 2 is in the abnormal working state, gives a fault prompt through the instrument panel, shuts down the whole vehicle, and enters the fault judgment mode;

[0039] S5: The VCU controller outputs that both Brake Switch 1 and Brake Switch 2 are in the normal working state, displays it through the instrument panel, and the whole vehicle runs normally;

[0040] S6: The VCU controller performs a comparison operation on the real-time detected braking deceleration signal a with braking decelerations A and B. If a = B, execute Step S7; if B < a < A, execute Step S8; if a ≥ A, execute Step S9;

[0041] S7: The VCU controller outputs that Brake Switch 1 is in the abnormal working state and Brake Switch 2 is in the normal working state, gives a fault prompt through the instrument panel, shuts down the whole vehicle, and enters the fault judgment mode;

[0042] S8: The VCU controller outputs that both Brake Switch 1 and Brake Switch 2 are in the normal working state, displays it through the instrument panel, and the whole vehicle runs normally;

[0043] S9: The VCU controller outputs that Brake Switch 1 is in the normal working state and Brake Switch 2 is in the abnormal working state, gives a fault prompt through the instrument panel, shuts down the whole vehicle, and enters the fault judgment mode;

[0044] S10: The VCU controller performs a comparison operation on the real-time detected braking deceleration signal a with the braking decelerations of A and B. If a = B, step S11 is executed; if B < a < A, step S12 is executed; if a ≥ A, step S13 is executed;

[0045] S11: The VCU controller outputs that both the braking switch one and the braking switch two are in normal working states, which are displayed through the instrument, and the whole vehicle runs normally;

[0046] S12: The VCU controller outputs that the braking switch one is in an abnormal working state and the braking switch two is in a normal working state, and gives a fault prompt through the instrument. The whole vehicle stops and enters the fault judgment mode;

[0047] S13: The VCU controller outputs that both the working states of the braking switch one and the braking switch two are abnormal, and gives a fault prompt through the instrument. The whole vehicle stops and enters the fault judgment mode;

[0048] S14: The VCU controller performs a comparison operation on the real-time detected braking deceleration signal a with the braking decelerations of A and B. If a = B, step S15 is executed; if B < a < A, step S16 is executed; if a ≥ A, step S17 is executed;

[0049] S15: The VCU controller outputs that the braking switch one is in a normal working state and the braking switch two is in an abnormal working state, and gives a fault prompt through the instrument. The whole vehicle stops and enters the fault judgment mode;

[0050] S16: The VCU controller outputs that both the working states of the braking switch one and the braking switch two are abnormal, and gives a fault prompt through the instrument. The whole vehicle stops and enters the fault judgment mode;

[0051] S17: The VCU controller outputs that the braking switch one is in an abnormal working state and the braking switch two is in a normal working state, and gives a fault prompt through the instrument. The whole vehicle stops and enters the fault judgment mode.

[0052] In the fault judgment mode, the whole vehicle can be powered on normally while the instrument gives a warning, and operations such as the whole vehicle cannot drive, the goods shelf cannot lift or tilt, etc.

[0053] When the whole vehicle is in the braking process, both the braking signal lamp and the instrument braking signal indicator light up.

[0054] Refer to Figure 2When the vehicle is started, the working status of brake switch one and brake switch two is judged. At this time, brake switch one and brake switch two are in the initial non-triggered state. When the initial state of brake switch one and brake switch two is abnormal, the vehicle cannot be used normally and a fault prompt will be displayed on the instrument. When the initial state of the brake switches is normal, pressing the brake pedal deeply will trigger brake switch one and brake switch two, and the working status of brake switch one and brake switch two will be judged.

[0055] When the vehicle is started, it will only operate normally if both brake switch one and brake switch two are found to be in normal working condition.

Claims

1. A fault detection method for a dual-brake switch braking system for an electric forklift, the dual-brake switch braking system for the electric forklift comprising: A brake pedal mechanism, a first brake switch, a second brake switch, a VCU controller, an instrument, and a brake signal lamp. The trigger point for the first brake switch to obtain the brake pedal signal in the brake pedal mechanism is set at the initial position of the brake pedal. The trigger point for the second brake switch to obtain the brake pedal signal in the brake pedal mechanism is set at a preset position in the brake pedal stroke and is different from the signal trigger point position of the first brake switch. The signal output ends of the first brake switch and the second brake switch are respectively connected to the signal input end of the VCU controller. The signal output end of the VCU controller is respectively connected to the signal input end of the instrument and the signal input end of the brake signal lamp. When the brake pedal stroke is at the signal trigger point position of the first brake switch, the braking deceleration rate fed back by the motor to the VCU controller is B. When the brake pedal stroke is at the signal trigger point position of the second brake switch, the braking deceleration rate fed back by the motor to the VCU controller is A. The braking deceleration rate A is greater than the braking deceleration rate B. It is characterized in that when the whole vehicle is in the braking process, the steps of the fault detection method of the braking system are as follows: S1: The VCU controller receives the switch signals fed back by the first brake switch and the second brake switch and the real-time detected braking deceleration rate signal a fed back by the motor. If the VCU controller receives that the first brake switch is in the closed state and the second brake switch is in the closed state, execute step S2; if the VCU controller receives that the first brake switch is in the closed state and the second brake switch is in the open state, execute step S6; if the VCU controller receives that the first brake switch is in the open state and the second brake switch is in the open state, execute step S10; if the VCU controller receives that the first brake switch is in the open state and the second brake switch is in the closed state, execute step S14; S2: The VCU controller performs a comparison operation on the real-time detected braking deceleration rate signal a with the braking deceleration rates A and B. If a = B, execute step S3; if B < a < A, execute step S4; if a ≥ A, execute step S5; S3: The VCU controller outputs that both the first brake switch and the second brake switch are in an abnormal working state, gives a fault prompt through the instrument, stops the whole vehicle, and enters the fault judgment mode; S4: The VCU controller outputs that the first brake switch is in a normal working state and the second brake switch is in an abnormal working state, gives a fault prompt through the instrument, stops the whole vehicle, and enters the fault judgment mode; S5: The VCU controller outputs that both the first brake switch and the second brake switch are in a normal working state, displays through the instrument, and the whole vehicle runs normally; S6: The VCU controller performs a comparison operation on the real-time detected braking deceleration rate signal a with the braking deceleration rates A and B. If a = B, execute step S7; if B < a < A, execute step S8; if a ≥ A, execute step S9; S7: The VCU controller outputs that the first brake switch is in an abnormal working state and the second brake switch is in a normal working state, gives a fault prompt through the instrument, stops the whole vehicle, and enters the fault judgment mode; S8: The VCU controller outputs that both the first brake switch and the second brake switch are in a normal working state, displays through the instrument, and the whole vehicle runs normally; S9: The VCU controller outputs that Brake Switch 1 is in normal working condition and Brake Switch 2 is in abnormal working condition, gives a fault prompt through the instrument panel, shuts down the whole vehicle, and enters the fault judgment mode; S10: The VCU controller compares and calculates the real-time detected brake deceleration signal a with the brake decelerations A and B. If a = B, execute step S11; if B < a < A, execute step S12; if a ≥ A, execute step S13; S11: The VCU controller outputs that both Brake Switch 1 and Brake Switch 2 are in normal working condition, displays it through the instrument panel, and the whole vehicle runs normally; S12: The VCU controller outputs that Brake Switch 1 is in abnormal working condition and Brake Switch 2 is in normal working condition, gives a fault prompt through the instrument panel, shuts down the whole vehicle, and enters the fault judgment mode; S13: The VCU controller outputs that both Brake Switch 1 and Brake Switch 2 are in abnormal working condition, gives a fault prompt through the instrument panel, shuts down the whole vehicle, and enters the fault judgment mode; S14: The VCU controller compares and calculates the real-time detected brake deceleration signal a with the brake decelerations A and B. If a = B, execute step S15; if B < a < A, execute step S16; if a ≥ A, execute step S17; S15: The VCU controller outputs that Brake Switch 1 is in normal working condition and Brake Switch 2 is in abnormal working condition, gives a fault prompt through the instrument panel, shuts down the whole vehicle, and enters the fault judgment mode; S16: The VCU controller outputs that both Brake Switch 1 and Brake Switch 2 are in abnormal working condition, gives a fault prompt through the instrument panel, shuts down the whole vehicle, and enters the fault judgment mode; S17: The VCU controller outputs that Brake Switch 1 is in abnormal working condition and Brake Switch 2 is in normal working condition, gives a fault prompt through the instrument panel, shuts down the whole vehicle, and enters the fault judgment mode.

2. The fault detection method for a dual-brake switch braking system for an electric forklift according to claim 1, characterized in that: When the whole vehicle is in the braking process, both the brake signal lamp and the instrument panel brake signal indicator light are on.

3. The fault detection method for a dual-brake switch braking system for an electric forklift according to claim 1, characterized in that: When the whole vehicle starts to run, the working conditions of Brake Switch 1 and Brake Switch 2 are judged. At this time, Brake Switch 1 and Brake Switch 2 are in the initial untriggered state. When the initial states of Brake Switch 1 and Brake Switch 2 are abnormal, the whole vehicle cannot be used normally, and a fault prompt is given on the instrument panel; when the initial states of the brake switches are normal, deeply step on the brake pedal to trigger Brake Switch 1 and Brake Switch 2, and judge whether the working conditions of Brake Switch 1 and Brake Switch 2 are normal.

4. The fault detection method for a dual-brake switch braking system for an electric forklift according to claim 3, characterized in that: When the whole vehicle starts to run, only when the judgments on the working conditions of Brake Switch 1 and Brake Switch 2 are both normal, the whole vehicle operates normally.

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