Driving starting control method of reach forklift

Abstract

The invention discloses a running starting control method of a reach forklift, which comprises the following steps of: detecting a voltage signal of a running accelerator of the forklift, judging whether a driver has an acceleration intention or not according to the voltage signal, and if so, monitoring a forward switch and a backward switch of the forklift; according to the collected forward switching value signal and the collected backward switching value signal, it is judged that the forklift is in driving wheel side driving or bearing wheel side driving during driving starting; the corresponding rotating speeds of a forklift traction motor and a forklift bearing wheel are obtained in real time, and the linear speed ratio K of the corresponding driving wheel to the bearing wheel is calculated; according to the linear speed ratio K and the driving state, whether the driving wheel is in a slipping state or not is judged, and if yes, the starting torque of the traction motor is reduced, so that the driving wheel does not slip. According to the invention, the accuracy and convenience of driving and starting of the forklift can be improved, and the running safety of the forklift is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of forklift starting control, and more specifically, to a driving starting control method for a reach forklift. Background Art

[0002] Since the mast of a reach forklift can move forward and backward along the inner guide rails of the outriggers, loading and unloading of goods is convenient and suitable for operations in narrow aisles and confined spaces. Existing reach forklifts have the following problems when driving and starting: under slippery road conditions, when driving and starting toward the drive side, the drive wheel will slip, causing wear of the drive wheel; under normal road conditions, when the mast (fork) moves forward to the load-bearing wheel end and drives and starts toward the drive wheel side, the drive wheel will slip, causing wear of the drive wheel. Therefore, it is of great significance to accurately and safely control the start of the forklift and quickly adjust the driving state of the forklift according to the driver's acceleration intention to avoid slipping, so as to improve the safety of the forklift operation. Summary of the invention

[0003] The present invention provides a driving and starting control method for a reach forklift, which solves the problem that the existing reach forklift is prone to slipping when driving and starting, and is unsafe. The method can improve the accuracy and convenience of the forklift's driving and starting, and increase the safety of the forklift's operation.

[0004] To achieve the above objectives, the present invention provides the following technical solutions:

[0005] A travel start control method for a reach forklift, comprising:

[0006] By detecting the voltage signal of the forklift's accelerator, and judging whether the driver has the intention to accelerate according to the voltage signal, if yes, monitoring the forward switch and reverse switch of the forklift;

[0007] According to the collected forward switch signal and reverse switch signal, it is judged whether the forklift is driving on the driving wheel side or the load wheel side when starting;

[0008] Obtain the corresponding rotation speed of the forklift traction motor and the forklift load-bearing wheel in real time, and calculate the corresponding linear speed ratio K of the driving wheel and the load-bearing wheel;

[0009] According to the linear speed ratio K and the driving state, it is determined whether the driving wheel is in a slipping state. If so, the starting torque of the traction motor is reduced to prevent the driving wheel from slipping.

[0010] Preferably, judging whether the driving wheel is in a slipping state according to the linear velocity ratio K and the driving state includes:

[0011] When the forklift starts to travel on the driving wheel side, if the ratio K of the driving wheel linear velocity to the load-bearing wheel linear velocity is greater than the slip setting threshold, it is determined that the driving wheel is in a slipping state.

[0012] Preferably, it also includes:

[0013] When the forklift starts driving on the driving wheel side, if the ratio K of the driving wheel linear speed to the load-bearing wheel linear speed is less than the slip setting threshold, the traction motor is controlled to rotate counterclockwise so that the traction motor starting torque is corrected according to the first starting torque coefficient, and the slip setting threshold is in the range of 0.97~1.03.

[0014] Preferably, it also includes:

[0015] When the forklift starts driving on the driving wheel side, if the ratio K of the driving wheel linear speed to the load-bearing wheel linear speed is greater than the slip setting threshold, the traction motor is controlled to rotate counterclockwise, and the traction motor starting torque is reduced according to the second starting torque coefficient.

[0016] Preferably, it also includes:

[0017] When the forklift starts driving on the load-bearing wheel side, the traction motor is controlled to rotate clockwise, and the traction motor torque is made equal to the starting torque setting value.

[0018] Preferably, the starting torque setting value T=Tmax*K3, wherein Tmax is the maximum torque of the traction motor, K3 is the third starting torque setting coefficient, and 0.7≤K3≤1.

[0019] Preferably, the starting torque of the traction motor is corrected according to the first starting torque coefficient, including:

[0020] The starting torque of the traction motor T1=Tmax*K1, wherein K1 is a first starting torque coefficient, and 0.5≤K1≤0.8.

[0021] Preferably, the starting torque of the traction motor is reduced according to the second starting torque coefficient, including:

[0022] The starting torque T1 of the traction motor = Tmax*K1*K2, wherein K2 is the second starting torque coefficient, and K2=0.2.

[0023] Preferably, the calculation to obtain the corresponding ratio K of the driving wheel linear velocity to the load-bearing wheel linear velocity includes:

[0024] It is calculated according to the formula: K=V2 / V1, where V1=2*PI*R1*n1*(C1 / 10), V2=2*PI*R2*n2*(C2 / 10)*i, V1 is the linear velocity of the load-bearing wheel, V2 is the linear velocity of the driving wheel, PI is pi, R1 is the rolling radius of the load-bearing wheel, R2 is the rolling radius of the driving wheel, n1 is the maximum speed set for the load-bearing wheel, n2 is the maximum speed set for the traction motor, C1 is the voltage signal of the load-bearing wheel speed sensor, C2 is the voltage signal of the traction motor speed sensor, and i is the speed ratio of the driving gearbox.

[0025] Preferably, when the forklift starts driving and is traveling on the driving wheel side or the load wheel side, the target speed n3 of the traction motor is n2*(C2 / 10).

[0026] The present invention provides a driving and starting control method for a reach forklift, which obtains the corresponding ratio K of the linear velocity of the driving wheel to the linear velocity of the load-bearing wheel by calculation, and judges whether the front drive wheel is in a slipping state according to the ratio K. When in a slipping state, the starting torque of the traction motor is reduced, so as to solve the problem that the existing reach forklift is prone to slipping and unsafe when driving and starting. It can improve the accuracy and convenience of the forklift's driving and starting, and increase the safety of the forklift's operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below.

[0028] Figure 1 The present invention provides a schematic diagram of a driving and starting control method for a reach forklift. DETAILED DESCRIPTION

[0029] In order to enable persons skilled in the art to better understand the solutions of the embodiments of the present invention, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and implementation modes.

[0030] The present invention provides a driving and starting control method for a reach forklift, which solves the problem that the current reach forklift is prone to slipping when starting, and is unsafe. The method can improve the accuracy and convenience of the forklift's driving and starting, and increase the safety of the forklift's operation.

[0031] like Figure 1 As shown, a driving and starting control method for a reach forklift includes:

[0032] 101: Detecting the voltage signal of the forklift's accelerator and judging whether the driver has the intention to accelerate based on the voltage signal, and if so, monitoring the forward switch and the reverse switch of the forklift.

[0033] 102: According to the collected forward switch signal and backward switch signal, it is determined whether the forklift is driving on the driving wheel side or the load wheel side when starting.

[0034] 103: Obtain the corresponding rotation speeds of the forklift traction motor and the forklift load-bearing wheel in real time, and calculate the corresponding linear speed ratio K of the driving wheel and the load-bearing wheel.

[0035] 104: According to the linear speed ratio K and the driving state, determine whether the driving wheel is in a slipping state. If so, reduce the starting torque of the traction motor to prevent the driving wheel from slipping.

[0036] Specifically, the travel system of the reach-type forklift includes a controller, a load-bearing wheel speed sensor, a traction motor speed sensor, a forklift travel accelerator, a forward switch, a reverse switch, etc. The load-bearing wheel speed sensor is used to detect the sensor signal C1 of the load-bearing wheel speed, and its variation range is 0-10V; the traction motor speed sensor is used to detect the sensor signal C2 of the traction motor speed, and its variation range is 0-10V; the forklift travel accelerator is used to detect the judgment signal C3 of the driver's acceleration intention, and its variation range is 0-5V; the forward switch is used to identify the forward switch signal C4 of the forklift's intention to travel to the drive wheel side, when C4=1, it indicates that the forklift is traveling to the drive wheel side; the reverse switch is used to identify the reverse switch signal C5 of the forklift's intention to travel to the load-bearing wheel side, when C5=1, it indicates that the forklift is traveling to the drive wheel side. The controller controls the rotation direction and torque of the traction motor according to the above signals, thereby controlling the driving direction and starting acceleration of the forklift. The controller calculates the linear velocity ratio K of the driving wheel and the load-bearing wheel, and determines whether the front drive wheel of the forklift is in a slipping state through the linear velocity ratio K. If so, the traction motor is controlled to reduce the starting torque so that the driving wheel does not slip. This method can improve the accuracy and convenience of the forklift's driving and starting, and increase the safety of the forklift's operation.

[0037] Further, judging whether the driving wheel is in a slipping state according to the linear velocity ratio K and the driving state includes:

[0038] When the forklift starts to travel on the driving wheel side, if the ratio K of the driving wheel linear velocity to the load-bearing wheel linear velocity is greater than the slip setting threshold, it is determined that the driving wheel is in a slipping state.

[0039] The method also includes: when the forklift starts driving on the driving wheel side, if the ratio K of the driving wheel linear velocity to the load-bearing wheel linear velocity is less than a slip setting threshold, controlling the traction motor to rotate counterclockwise so that the traction motor starting torque is corrected according to a first starting torque coefficient, and the slip setting threshold is in the range of 0.97 to 1.03.

[0040] The method also includes: when the forklift is driving and starting on the driving wheel side, if the ratio K of the driving wheel linear velocity to the load-bearing wheel linear velocity is greater than a slip setting threshold, controlling the traction motor to rotate counterclockwise and reducing the traction motor starting torque according to a second starting torque coefficient.

[0041] The method further includes: when the forklift is driving and starting on the load-bearing wheel side, controlling the traction motor to rotate clockwise and making the traction motor torque equal to the starting torque setting value.

[0042] Furthermore, the starting torque setting value T=Tmax*K3, wherein Tmax is the maximum torque of the traction motor, K3 is the third starting torque setting coefficient, and 0.7≤K3≤1.

[0043] Further, the starting torque of the traction motor is corrected according to the first starting torque coefficient, including:

[0044] The starting torque of the traction motor T1=Tmax*K1, wherein K1 is a first starting torque coefficient, and 0.5≤K1≤0.8.

[0045] Further, the starting torque of the traction motor is reduced according to a second starting torque coefficient, including:

[0046] The starting torque T1 of the traction motor = Tmax*K1*K2, wherein K2 is the second starting torque coefficient, and K2=0.2.

[0047] Further, the calculation to obtain the corresponding ratio K of the driving wheel linear velocity to the load-bearing wheel linear velocity includes:

[0048] It is calculated according to the formula: K=V2 / V1, where V1=2*PI*R1*n1*(C1 / 10), V2=2*PI*R2*n2*(C2 / 10)*i, V1 is the linear velocity of the load-bearing wheel, V2 is the linear velocity of the driving wheel, PI is pi, R1 is the rolling radius of the load-bearing wheel, R2 is the rolling radius of the driving wheel, n1 is the maximum speed set for the load-bearing wheel, n2 is the maximum speed set for the traction motor, C1 is the voltage signal of the load-bearing wheel speed sensor, C2 is the voltage signal of the traction motor speed sensor, and i is the speed ratio of the driving gearbox.

[0049] Furthermore, when the forklift starts to travel on the driving wheel side or the load wheel side, the target speed n3 of the traction motor is n2*(C2 / 10).

[0050] In one embodiment, the control process includes the following steps:

[0051] S1: The sensor signal C1 that monitors the load-bearing wheel speed. The controller calculates the load-bearing wheel linear speed V1=2*PI*R1*n1*(C1 / 10) based on C1.

[0052] S2, the sensor signal C2 for monitoring the traction motor speed, the controller calculates the driving wheel linear speed V2=2*PI*R2*n2*(C2 / 10)*i according to the sensor signal C2.

[0053] S3, monitoring the judgment signal C3 of the vehicle's acceleration intention, the forward switch signal C4, and the reverse switch signal C5.

[0054] S4. The controller calculates the ratio K of the linear velocity of the driving wheel to the linear velocity of the load-bearing wheel, K=V2 / V1.

[0055] When C5=1, execute S5; when C4=1, K≤slip setting threshold (driving wheel does not slip), execute S6; when C4=1, K>slip setting threshold (driving wheel slips), execute S7.

[0056] S5. The controller controls the traction motor to rotate clockwise, the target speed of the traction motor n3=n2*(C2 / 10), and the torque of the traction motor T1=Tmax*K3.

[0057] K3 is the third starting torque setting coefficient, and 0.7≤K3≤1, and K3 is set according to the starting acceleration requirement of the vehicle.

[0058] S6. The controller controls the traction motor to rotate counterclockwise, the traction motor target speed n3=n2*(C2 / 10), and the traction motor torque T1=Tmax*K1. At this time, the vehicle drives on the side of the driving wheel, and K≤slip setting threshold.

[0059] K1 is the first starting torque coefficient, and 0.5≤K1≤0.8. K1 can be set according to the starting acceleration requirement of the vehicle.

[0060] S7. The controller controls the traction motor to rotate counterclockwise, the target speed of the traction motor is n3=n2*(C2 / 10), and the torque of the traction motor is Tmax*K1*K2. At this time, the vehicle drives on the driving wheel side, K>slip setting threshold, where K2 is the second starting torque coefficient, and K2=0.2.

[0061] It can be seen that the present invention provides a driving and starting control method for a reach forklift, which obtains the corresponding ratio K of the linear velocity of the driving wheel to the linear velocity of the load-bearing wheel by calculation, and determines whether the front drive wheel is in a slipping state according to the ratio K. When in a slipping state, the starting torque of the traction motor is reduced, thereby solving the problem that the existing reach forklift is prone to slipping during driving and starting, which is unsafe. It can improve the accuracy and convenience of the forklift's driving and starting, and increase the safety of the forklift's operation.

[0062] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A travel start control method for a reach forklift, characterized in that: include: By detecting the voltage signal of the forklift's accelerator, and judging whether the driver has the intention to accelerate according to the voltage signal, if yes, monitoring the forward switch and reverse switch of the forklift; According to the collected forward switch signal and reverse switch signal, it is judged whether the forklift is driving on the driving wheel side or the load wheel side when starting; Obtain the corresponding rotation speed of the forklift traction motor and the forklift load-bearing wheel in real time, and calculate the corresponding linear speed ratio K of the driving wheel and the load-bearing wheel; According to the linear speed ratio K and the driving state, it is determined whether the driving wheel is in a slipping state. If so, the starting torque of the traction motor is reduced to prevent the driving wheel from slipping.

2. The driving start control method of a reach forklift according to claim 1, characterized in that: The step of judging whether the driving wheel is in a slipping state according to the linear velocity ratio K and the driving state includes: When the forklift starts to travel on the driving wheel side, if the ratio K of the driving wheel linear velocity to the load-bearing wheel linear velocity is greater than the slip setting threshold, it is determined that the driving wheel is in a slipping state.

3. The driving start control method of a reach forklift according to claim 2, characterized in that: Also includes: When the forklift starts driving on the driving wheel side, if the ratio K of the driving wheel linear speed to the load-bearing wheel linear speed is less than the slip setting threshold, the traction motor is controlled to rotate counterclockwise so that the traction motor starting torque is corrected according to the first starting torque coefficient, and the slip setting threshold is in the range of 0.97~1.

03.

4. The driving start control method of a reach forklift according to claim 3, characterized in that: Also includes: When the forklift starts driving on the driving wheel side, if the ratio K of the driving wheel linear speed to the load-bearing wheel linear speed is greater than the slip setting threshold, the traction motor is controlled to rotate counterclockwise, and the traction motor starting torque is reduced according to the second starting torque coefficient.

5. The driving start control method of a reach forklift according to claim 4, characterized in that: Also includes: When the forklift starts driving on the load-bearing wheel side, the traction motor is controlled to rotate clockwise, and the traction motor torque is made equal to the starting torque setting value.

6. The driving start control method of a reach forklift according to claim 5, characterized in that: The starting torque setting value T=Tmax*K3, wherein Tmax is the maximum torque of the traction motor, K3 is the third starting torque setting coefficient, and 0.7≤K3≤1.

7. The driving start control method of a reach forklift according to claim 6, characterized in that: The starting torque of the traction motor is corrected according to the first starting torque coefficient, including: The starting torque of the traction motor T1=Tmax*K1, wherein K1 is a first starting torque coefficient, and 0.5≤K1≤0.

8.

8. The driving start control method of a reach forklift according to claim 7, characterized in that: The traction motor starting torque is reduced according to a second starting torque coefficient, including: The starting torque T1 of the traction motor = Tmax*K1*K2, wherein K2 is the second starting torque coefficient, and K2=0.

2.

9. The driving start control method of a reach forklift according to claim 8, characterized in that: The calculation to obtain the corresponding ratio K of the driving wheel linear velocity to the load-bearing wheel linear velocity includes: It is calculated according to the formula: K=V2 / V1, where V1=2*PI*R1*n1*(C1 / 10), V2=2*PI*R2*n2*(C2 / 10)*i, V1 is the linear velocity of the load-bearing wheel, V2 is the linear velocity of the driving wheel, PI is pi, R1 is the rolling radius of the load-bearing wheel, R2 is the rolling radius of the driving wheel, n1 is the maximum speed set for the load-bearing wheel, n2 is the maximum speed set for the traction motor, C1 is the voltage signal of the load-bearing wheel speed sensor, C2 is the voltage signal of the traction motor speed sensor, and i is the speed ratio of the driving gearbox.

10. The driving start control method of a reach forklift according to claim 9, characterized in that: When the forklift starts driving on the driving wheel side or the load wheel side, the target speed n3 of the traction motor is n2*(C2 / 10).

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