Method for detecting steering force of forklift steering wheel

Abstract

The application provides a forklift steering wheel steering force detection system and method, comprising: collecting the steering torque of the steering wheel; collecting the input voltage of the steering motor; calibrating the rotating speed of the steering wheel by adjusting the input voltage value of the steering motor; detecting the rotating circle number of the steering wheel, obtaining the time required for the steering wheel to rotate one circle according to the rotating speed of the steering wheel, and setting the forward and reverse rotation time of the steering motor according to the time; and obtaining the steering force of the steering wheel under different rotating speed conditions. The application fully considers the influence of the rotating speed of the steering wheel on the steering force, and accurately detects the steering force of the steering wheel when it rotates forward and backward under different rotating speeds.

Description

Technical Field

[0001] This invention relates to a forklift, and more particularly to a system and method for detecting the steering force of a forklift steering wheel. Background Technology

[0002] In recent years, with the rapid development of my country's economy, various large-scale infrastructure construction projects, docks, freight yards, manufacturing industries, tourist attractions, logistics centers, and other industries have sprung up like mushrooms after rain, leading to the widespread application of forklifts. However, due to their relatively harsh working environment, often involving load operations in open or confined spaces, forklifts face high safety performance requirements. For example, the "Special Equipment Safety Technical Specifications" stipulate that for power steering forklifts, the hand operating force applied to the steering wheel during steering should be 6N-20N, with a difference of no more than 5N between left and right steering forces; for mechanical steering vehicles, the hand operating force applied to the steering wheel during steering should not exceed 150N. Therefore, steering force is a crucial performance indicator for forklifts, directly reflecting their maneuverability, and its results directly impact their market competitiveness. Thus, accurate measurement of steering force is extremely important.

[0003] Current methods for testing forklift steering force use a torque meter mounted on the steering wheel, requiring the operator to manually rotate the wheel. Because this method relies on manual steering, the steering wheel speed cannot be accurately controlled, and the speed of rotation significantly impacts steering force. This ultimately affects the consistency and standardization of test results, as well as subsequent precise analysis and improvement. Summary of the Invention

[0004] The purpose of this invention is to provide a system and method for detecting steering force of a forklift steering wheel, which can accurately control the rotation speed and steering time of the steering wheel, and display the changes in steering force throughout the process, ultimately achieving accurate detection of steering force of the forklift steering wheel.

[0005] To meet the above requirements, the technical solution of the present invention is as follows:

[0006] A method for detecting the steering force of a forklift steering wheel, comprising the following steps:

[0007] (1) Collect the steering torque T of the steering wheel 方向盘 ;

[0008] (2) Collect the input voltage U of the steering motor 转向电机 ;

[0009] (3) By adjusting the input voltage U of the steering motor 转向电机 The size is used to calibrate the steering wheel speed V. 方向盘 ;

[0010] (4) Detect the number of turns N of the steering wheel.方向盘 According to the steering wheel speed V 方向盘 Calculate the time t required for the steering wheel to turn one revolution. 方向盘 According to t 方向盘 To set the forward and reverse rotation time of the steering motor;

[0011] (5) According to F 方向盘 =T 方向盘 / r 方向盘 The steering force required for forward and reverse rotation of the steering wheel under different speed conditions is obtained, where r 方向盘 The radius of the steering wheel.

[0012] In a further embodiment, the steering torque of the steering wheel in step (1) is obtained by a torque sensor installed on the steering column of the steering wheel.

[0013] In a further embodiment, the input voltage of the steering motor in step (2) is obtained by collecting the output voltage of the motor speed controller. The motor speed controller is equipped with a voltage adjustment knob, and the speed of the steering wheel is adjusted by rotating the adjustment knob.

[0014] Preferably, in step (3), the steering wheel rotation speed V 方向盘 The calibration results are as follows:

[0015]

[0016] Preferably, when the positive terminal of the steering motor is connected to the positive terminal of the output power supply of the motor speed controller, the steering wheel turns forward; when the positive terminal of the steering motor is connected to the negative terminal of the output power supply of the motor speed controller, the steering wheel turns backward.

[0017] Further options, when U 转向电机 When U is positive, it indicates that the steering wheel is turning forward; when U is positive, it indicates that the steering wheel is turning forward. 转向电机 A negative value indicates that the steering wheel is reversed;

[0018] When the steering torque T 方向盘 When the value is positive, it indicates that the steering wheel is turning forward, and the steering torque T is positive. 方向盘 A negative value indicates that the steering wheel is in reverse.

[0019] The second objective of this invention is to provide a forklift steering wheel force detection system, including a torque sensor mounted on the steering column of the steering wheel, the torque sensor being rigidly connected to a steering motor, the power supply terminal of the steering motor being electrically connected to a motor speed controller, and the motor speed controller being electrically connected to a power source to provide power.

[0020] In a further embodiment, a contactor is connected between the steering motor and the motor speed controller. The coil of the contactor is connected to the power supply through a time relay, and the contacts of the contactor are connected in series between the steering motor and the motor speed controller.

[0021] In a further embodiment, the contactor has two sets of contacts consisting of normally open and normally closed contacts, which are connected in series to the positive and negative output terminals of the motor speed controller.

[0022] A further embodiment also includes a data acquisition processor, which is connected to both the motor speed controller and the torque sensor to acquire the output voltage of the motor speed controller and the steering torque of the torque sensor, respectively.

[0023] This application detects the steering wheel torque using a torque sensor, adjusts the output voltage of the motor speed controller by adjusting a knob on the controller, thus obtaining the input voltage of the steering motor. The steering wheel speed is then calibrated using this input voltage, allowing the determination of the steering wheel speed under different voltage conditions. Finally, the real-time steering force under different speed conditions is calculated. This fully considers the influence of steering wheel speed on steering force, accurately detecting the steering force.

[0024] This application uses a time relay to precisely control the forward and reverse rotation time of the steering wheel, thereby ensuring that the steering wheel automatically turns to the limit position and then immediately turns in the opposite direction, completing the automatic detection of steering force at different speeds of the steering wheel. Attached Figure Description

[0025] Figure 1 This is a schematic diagram illustrating the principle of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments and 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1:

[0028] A forklift steering wheel force detection system includes the following steps:

[0029] (1) The steering torque T of the steering wheel is collected by a torque sensor installed on the steering column of the steering wheel. 方向盘 ;

[0030] (2) Rotate the adjustment knob to adjust the output voltage of the motor speed controller and detect the real-time input voltage U of the steering motor. 转向电机 ;

[0031] (3) By adjusting the input voltage U of the steering motor 转向电机The size is used to calibrate the steering wheel speed V. 方向盘 ;

[0032] Utilizing the voltage and speed regulation principle of DC steering motors, the input power voltage of the steering motor is changed by adjusting the knob on the motor regulator, thereby altering the motor's speed. Rotating the knob to the right increases the steering motor voltage and thus its speed; conversely, rotating it to the left decreases the speed.

[0033] That is, when the speed controller knob is turned to the scale of 20, the input voltage U of the steering motor is... 转向电机 The voltage is 1.57V, at which point the steering wheel speed V is... 方向盘 The speed is 9.3 rpm, as detailed below:

[0034]

[0035] (4) Detect the number of turns N of the steering wheel. 方向盘 The number of rotations can be counted by eye movement or by installing a counter on the steering wheel. The specific operation is as follows: First, turn the steering wheel clockwise until it can no longer be turned; this point is taken as a reference point. Then, turn the steering wheel counterclockwise, recording each time it passes the reference point as one rotation, until the steering wheel can no longer be turned counterclockwise. The number of rotations N is then obtained. 方向盘 ;

[0036] According to the steering wheel speed V 方向盘 Calculate the time t required for the steering wheel to turn one revolution. 方向盘 The specific formula is: t 方向盘 =N 方向盘 / V 方向盘 ;

[0037] Then according to t 方向盘 To set the forward and reverse rotation time of the steering motor, ensuring that the steering wheel automatically turns to the limit position and then immediately turns in the opposite direction, thus completing the automatic detection of steering force at different steering wheel speeds;

[0038] (5) According to F 方向盘 =T 方向盘 / r 方向盘 The steering force required for forward and reverse rotation of the steering wheel under different speed conditions is obtained, where r 方向盘 The radius of the steering wheel.

[0039] In this embodiment, the determination of the steering wheel's forward and reverse direction is based on the following three aspects:

[0040] When the positive terminal of the steering motor is connected to the positive terminal of the motor speed controller's output power, the steering wheel turns forward; when the positive terminal of the steering motor is connected to the negative terminal of the motor speed controller's output power, the steering wheel turns backward.

[0041] When U转向电机 When U is positive, it indicates that the steering wheel is turning forward; when U is positive, it indicates that the steering wheel is turning forward. 转向电机 A negative value indicates that the steering wheel is reversed;

[0042] When the steering torque T 方向盘 When the value is positive, it indicates that the steering wheel is turning forward, and the steering torque T is positive. 方向盘 A negative value indicates that the steering wheel is in reverse.

[0043] Example 2:

[0044] See Figure 1 A forklift steering wheel force detection system includes a torque sensor 6. One end of the torque sensor 6 is connected to a steering motor 5 via a key, and the other end is mounted on the steering column drive shaft of a steering wheel 7 via a transition fixture. The steering motor 5 is fixed to the outriggers of the forklift overhead guard via the fixture, and the two are rigidly connected. When the steering motor 5 rotates, it drives the torque sensor 6 to rotate, which in turn drives the steering column drive shaft of the steering wheel 7 to rotate, thereby driving the wheels to rotate. The power supply terminal of the steering motor 5 is electrically connected to a motor speed controller 7 via a contactor 3. Specifically, the coil of the contactor 3 is connected to a power supply 1 via a time relay 2, and the contacts of the contactor 3 are connected in series between the steering motor 5 and the motor speed controller 4. The motor speed controller 4 is electrically connected to the power supply 1 to provide power.

[0045] It also includes a data acquisition processor 8, which is a conventional product in the field and is commercially available. The data acquisition processor 8 is connected to the motor speed controller 4 and the torque sensor 6 respectively, and acquires the output voltage of the motor speed controller 4 and the steering torque of the torque sensor 6.

[0046] In this embodiment, the steering motor 5 is a DC 12V motor with a speed range of 0.1-3 r / s.

[0047] The torque sensor has an output voltage of ±5V and a range of ±3Nm.

[0048] Time relay 2 is powered by 12V and is used to control the on / off time of the steering motor's forward and reverse rotation. The control on / off time can be as low as 0.1s and as high as 99h. When the steering motor is operating at different working voltages, the corresponding on and off times of the time relay are set. This ensures that the steering wheel automatically turns in the opposite direction immediately after reaching its limit position, thus completing the automatic detection of steering force at different steering wheel speeds.

[0049] Contactor 3 is a 12V DC contactor used to control the positive and negative terminals of the input voltage to the steering motor. The contacts of contactor 3 consist of two sets of contacts, one normally open and one normally closed, connected in series with the positive and negative terminals of the power output of the motor speed controller 4. Figure 1As shown, normally closed contact K1 and normally open contact K2 form a contact group, and normally closed contact K4 and normally open contact K3 form a second contact group.

[0050] Power supply 1 is a 12V DC power supply.

[0051] By adjusting the adjustment knob on the motor speed controller 4, the output voltage is changed, which in turn adjusts the input power supply to the steering motor, thereby controlling the steering wheel speed. Based on the number of steering wheel rotations and the speed, the time required for one full rotation of the steering wheel can be calculated, allowing the setting of the on / off time of the time relay 2.

[0052] Time relay 2 is energized, and its output terminal is connected to the positive terminal of the coil of contactor 3. The negative terminal of the coil of contactor 3 is connected to the negative terminal of power supply 1 to form a circuit.

[0053] When time relay 2 is turned on, the coil of contactor 3 is energized, its normally closed contacts K1 and K4 are open, and its normally open contacts K2 and K3 are closed. The positive terminal of the voltage regulation output of motor speed controller 4 is connected to the negative terminal of the power input of steering motor 5 through normally open contact K2, and the negative terminal of the voltage regulation output is connected to the positive terminal of the power input of steering motor 5 through normally open contact K3. That is, the steering motor is in reverse.

[0054] When the output of time relay 2 is in the open state, the coil of contactor 3 is not energized, its normally closed contacts K1 and K4 are closed, and its normally open contacts K2 and K3 are open. The voltage regulation output terminal "+" of motor speed controller 4 is connected to the power input terminal "+" of steering motor 5 through normally closed contact K1, and the voltage regulation output terminal "-" is connected to the power input terminal "-" of steering motor 5 through normally closed contact K4. That is, steering motor 5 is in the forward rotation state.

[0055] The data acquisition processor 8 collects the output voltage of the motor speed controller 4 and the steering torque of the torque sensor 6, respectively, and calculates the steering force of the steering wheel under different speeds and forward / reverse conditions. This ensures the consistency and standardization of the test results, as well as subsequent accurate analysis and improvement.

[0056] Example 3:

[0057] This embodiment uses the CPD25 forklift as an example for illustration as follows:

[0058] 1. First, connect the steering motor and the torque sensor with a flat key. The steering motor is installed on the support leg of the overhead guard, and the other end of the torque sensor is installed on the steering column of the steering wheel through a transition fixture.

[0059] 2. Power the time relay, contactor, motor speed controller and data acquisition processor through a 12V DC power supply. The data acquisition processor powers the torque sensor. The data acquisition processor reads the input voltage value of the steering motor and the steering torque value detected by the torque sensor.

[0060] 3. Turn the steering wheel. First, turn the steering wheel counterclockwise to the end and record this as the reference point. Then, turn the steering wheel clockwise to the end and record the number of steering wheel rotations as 5. Then, turn it in the opposite direction and record the number of steering wheel rotations as 5.

[0061] 4. The radius of the steering wheel is measured to be 0.120m;

[0062] 5. Measure the steering force at a steering wheel speed of 30 rpm:

[0063] 5.1 The time required to turn the steering wheel 5 times is: 5 / (30 / 60) = 10 seconds. Set the on and off time of the time relay to 10 seconds.

[0064] 5.2 Based on the steering wheel rotation speed V 方向盘 According to the calibration results, when the steering wheel speed is 30 rpm, the power supply voltage of the steering motor needs to be 4.19V. Then adjust the adjustment knob on the motor speed controller and check the output voltage value of the motor speed controller in real time through the data acquisition processor. When the value is 4.19V, stop turning the adjustment knob.

[0065] 5.3 Power is supplied to the time relay and contactor, and the steering motor starts working. After the steering wheel rotates for 10 seconds, the steering motor rotates in the opposite direction, and this cycle repeats. The steering torque curve is recorded in real time by the data acquisition processor. According to the steering wheel steering force detection standard requirements, it is measured three times. The maximum right-turn torque is 0.93 Nm and the maximum left-turn torque is 0.99 Nm. Through calculation, the steering wheel steering force is calculated as follows: right-turn steering force: 0.93 / 0.12 = 7.75 N, left-turn steering force: 0.99 / 0.12 = 8.25 N.

[0066] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0067] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for detecting the steering force of a forklift steering wheel, characterized in that: Includes the following steps: (1) Collect the steering torque T of the steering wheel 方向盘 ; (2) Collect the input voltage U of the steering motor 转向电机 ; (3) By adjusting the input voltage U of the steering motor 转向电机 The size is used to calibrate the steering wheel speed V. 方向盘 ; (4) Detect the number of turns N of the steering wheel. 方向盘 According to the steering wheel speed V 方向盘 Calculate the time t required for the steering wheel to turn one revolution. 方向盘 According to t 方向盘 To set the forward and reverse rotation time of the steering motor; (5) According to F 方向盘 =T 方向盘 / r 方向盘 The steering force required for forward and reverse rotation of the steering wheel under different speed conditions is obtained, where r 方向盘 The radius of the steering wheel.

2. The detection method according to claim 1, characterized in that: In step (1), the steering torque of the steering wheel is obtained by a torque sensor installed on the steering column of the steering wheel.

3. The detection method according to claim 1, characterized in that: In step (2), the input voltage of the steering motor is obtained by collecting the output voltage of the motor speed controller. The motor speed controller is equipped with a voltage adjustment knob, and the speed of the steering wheel is adjusted by rotating the adjustment knob.

4. The detection method according to claim 3, characterized in that: In step (3), the steering wheel rotation speed V 方向盘 The calibration results are as follows: 。 5. The detection method according to claim 3, characterized in that: When the positive terminal of the steering motor is connected to the positive terminal of the motor speed controller's output power, the steering wheel turns forward; when the positive terminal of the steering motor is connected to the negative terminal of the motor speed controller's output power, the steering wheel turns backward.

6. The detection method according to claim 1, characterized in that: When U 转向电机 When U is positive, it indicates that the steering wheel is turning forward; when U is positive, it indicates that the steering wheel is turning forward. 转向电机 A negative value indicates that the steering wheel is reversed; When the steering torque T 方向盘 When the value is positive, it indicates that the steering wheel is turning forward, and the steering torque T is positive. 方向盘 A negative value indicates that the steering wheel is in reverse.

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