CN117755383A - Electric steering gear - Google Patents

Abstract

The invention discloses an electric steering gear, comprising: a driving motor; the input shaft is in transmission connection with the steering wheel and is in transmission connection with the driving motor, and a plurality of first transmission gears are arranged on the input shaft; the torque rod shaft is provided with a plurality of second transmission gears and a plurality of electric control actuators, the plurality of first transmission gears and the plurality of second transmission gears are meshed in a one-to-one correspondence manner and form a plurality of groups of gear sets, and the transmission ratio of each group of gear sets is different; the output shaft is in transmission connection with the torsion bar shaft; and the controller is electrically connected with the driving motor. The controller can control the electric control actuator to mesh the corresponding second transmission gear with the torsion bar shaft according to the signals acquired by the sensor so as to drive the output shaft to rotate, so that the output shaft outputs corresponding torque value and rotation angle value, and the power is not lost, and the power of the motor is utilized to the maximum extent.

Description

Electric steering gear

Technical Field

The invention relates to the technical field of automobiles, in particular to an electric steering gear.

Background

In general, an Electric Power Steering (EPS) is provided with a motor serving as a driving source and a torque sensor. The torque sensor outputs a sensor signal based on a torsion force of a torsion bar provided in the middle of the steering shaft. Then, in response to the steering torque detected based on the sensor signal sent from the torque sensor, the torque in the motor is controlled so that an appropriate assist force is applied to the steering system in accordance with the steering torque. Therefore, it is necessary to detect the steering torque in a stable and highly accurate manner in the electric power steering.

In the related art, the electric steering gear cannot be well matched with corresponding torque, the service lives of the motor and the whole steering gear can be reduced, the output torque value is always a larger value due to the fixed gear ratio, and when the vehicle needs smaller steering force, excessive power is not needed, so that the power of the motor is wasted.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the invention provides the electric steering gear, and the controller can control the electric control actuator to mesh the corresponding second transmission gear with the torsion bar shaft according to the signals acquired by the sensor so as to drive the output shaft to rotate, so that the output shaft outputs corresponding torque value and rotation angle value, the power is not lost, and the power of the motor is utilized to the maximum extent.

An electric power steering apparatus according to an embodiment of a first aspect of the present invention includes: a driving motor; the input shaft is in transmission connection with the steering wheel and is in transmission connection with the driving motor, and a plurality of first transmission gears are arranged on the input shaft; the torsion bar shaft is provided with a plurality of second transmission gears and a plurality of electric control actuators, the electric control actuators are in one-to-one correspondence with the second transmission gears, the electric control actuators are used for meshing the second transmission gears with the torsion bar shaft, the first transmission gears are in one-to-one correspondence with the second transmission gears and form a plurality of groups of gear sets, and the transmission ratio of each group of gear sets is different; the output shaft is in transmission connection with the torsion bar shaft; a controller electrically connected to the drive motor and the electrically controlled actuator, the controller configured to: the controller controls the driving motor to start according to a corner signal, a torque signal, an engine rotating speed signal and a vehicle speed signal transmitted from the steering wheel end, the driving motor drives the plurality of first transmission gears of the input shaft to rotate, and the controller controls the electric control actuator to engage the second transmission gears with the torsion bar shaft together so as to drive the output shaft to rotate.

According to the electric steering gear disclosed by the embodiment of the invention, the controller can control the electric control actuator to mesh the corresponding second transmission gear with the torsion bar shaft according to the signal acquired by the sensor so as to drive the output shaft to rotate, so that the output shaft outputs a corresponding torque value and a corresponding rotation angle value, the power is not lost, and the power of the motor is utilized to the maximum extent.

According to the electric power steering gear provided by the embodiment of the invention, the gear sets are three groups.

According to the electric power steering gear of the embodiment of the invention, the transmission ratios of three groups of gear sets are i1, i2 and i3 respectively, and the relation is satisfied by i1, i2 and i 3: i1 is more than or equal to 22.5 and less than or equal to 23.5, i2 is more than or equal to 19.5 and less than or equal to 21.5, and i1 is more than or equal to 17.5 and less than or equal to 18.5.

According to some embodiments of the invention, the controller has a boost mode in which the controller is further configured to: and transmitting the torque signal, the vehicle speed signal and the angle signal to the controller, acquiring a power-assisted torque value by the controller according to the steering wheel angle value, the torque value and the vehicle speed signal, transmitting the power-assisted torque value to the driving motor, and outputting the corresponding power-assisted torque value by the driving motor.

According to some embodiments of the invention, the controller has a return mode in which the controller is further configured to: and transmitting the torque signal, the vehicle speed signal and the angle signal to the controller, acquiring a positive torque value by the controller according to the steering wheel angle value, the torque value and the vehicle speed signal, transmitting the positive torque value to the driving motor, and outputting a corresponding positive torque value by the driving motor.

According to some embodiments of the invention, the controller has a damping compensation mode in which the controller is further configured to: and transmitting the torque signal, the vehicle speed signal and the angle signal to the controller, acquiring a damping compensation torque value by the controller according to the steering wheel angle value, the torque value and the vehicle speed signal, transmitting the damping compensation torque value to the driving motor, and outputting the corresponding damping compensation torque value by the driving motor.

According to some embodiments of the invention, the controller has a friction compensation mode in which the controller is further configured to: and transmitting the torque signal, the vehicle speed signal and the angle signal to the controller, acquiring a friction compensation torque value by the controller according to the steering wheel angle value, the torque value and the vehicle speed signal, transmitting the friction compensation torque value to the driving motor, and outputting the corresponding friction compensation torque value by the driving motor.

According to some embodiments of the invention, the controller has an auxiliary compensation mode in which the controller is further configured to: and transmitting the torque signal, the vehicle speed signal and the angle signal to the controller, acquiring an auxiliary compensation torque value by the controller according to the steering wheel angle value, the torque value and the vehicle speed signal, transmitting the auxiliary compensation torque value to the driving motor, and outputting the corresponding auxiliary compensation torque value by the driving motor.

According to some embodiments of the invention, the controller has a protection mode in which the controller is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller, the controller obtains a power-reducing signal according to the steering wheel angle value, the torque value and the vehicle speed signal, and the controller controls the driving motor to output a corresponding torque value according to the power-reducing signal.

According to some embodiments of the invention, the electric power steering apparatus further includes: the steering device comprises a steering angle sensor and a torque sensor, wherein the steering angle sensor and the torque sensor are arranged on an input shaft and are electrically connected with a controller, the torque sensor is used for detecting torque change, and the steering angle sensor is used for detecting an angle value of a steering wheel.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic view of an internal transmission structure of an electric power steering apparatus according to an embodiment of the present invention;

fig. 2: the overall control logic schematic diagram of the electric steering gear according to the embodiment of the invention;

fig. 3: an electric power steering apparatus according to an embodiment of the present invention is a basic functional schematic diagram of an electric power steering apparatus.

Reference numerals:

100. an electric power steering device;

10. an input shaft; 11. a torque sensor; 12. a rotation angle sensor;

20. a driving motor;

30. a first transmission gear;

40. a torsion bar shaft; 41. a second transmission gear; 42. an electric control actuator;

50. an output shaft;

60. and a controller.

Detailed Description

Embodiments of the present invention will be described in detail below, by way of example with reference to the accompanying drawings.

An electric power steering apparatus 100 according to an embodiment of the present invention is described below with reference to fig. 1 to 3.

As shown in fig. 1 to 2, the electric power steering apparatus 100 includes: the drive motor 20, the input shaft 10, the torsion bar shaft 40, the output shaft 50, and the controller 60. The driving motor 20 can be controlled by the controller 60 to rotate a motor shaft, the motor shaft rotates to drive a gear of the input shaft 10 to rotate, and the gear of the input shaft 10 rotates to drive an output shaft to rotate.

The input shaft 10 is in driving connection with the steering wheel, and the input shaft 10 is in driving connection with the drive motor 20, and a plurality of first transmission gears 30 are provided on the input shaft. The controller 60 may receive a rotation angle signal, a torque signal, an engine speed signal, and a vehicle speed signal from the steering wheel end through the input shaft 10, so that the controller 60 controls the driving motor 20 to rotate. The first transmission gear 30 of the input shaft 10 is in geared connection with the drive motor 20, the first transmission gear 30 of the input shaft 10 is also in geared connection with the torsion bar shaft 40, and the output shaft 50 will produce a power assistance to the wheels. In addition, the plurality of first transmission gears 30 are rigidly connected to the shaft body of the input shaft 10, and when the controller 60 controls the driving motor 20 to rotate, the gears of the driving motor 20 drive the first transmission gears 30 of the input shaft 10 to rotate, so as to drive the output shaft 50 to rotate. Specifically, the plurality of first transmission gears 30 is three.

And, the output shaft 50 is in transmission connection with the torsion bar shaft 40, and the torsion bar shaft 40 rotates to drive the output shaft 50 to rotate.

In addition, the torsion bar shaft 40 is provided with a plurality of second transmission gears 41 and a plurality of electric control actuators 42, the plurality of electric control actuators 42 are in one-to-one correspondence with the plurality of second transmission gears 41, the electric control actuators 42 mesh the second transmission gears 41 with the torsion bar shaft 40 together, the plurality of first transmission gears 30 are in one-to-one correspondence with the plurality of second transmission gears 41 and form a plurality of groups of gear sets, and the transmission ratio of each group of gear sets is different. That is, the torsion bar shaft 40 is provided with a plurality of second transmission gears 41 and a plurality of electric control actuators 42, the number of the electric control actuators 42 is identical to that of the second transmission gears 41, and the positions are in one-to-one correspondence, and the electric control actuators 42 can mutually mesh the second transmission gears 41 with the torsion bar shaft 40. The second transmission gear 41 is selectively meshed with the torsion bar shaft 40, and the electric control actuator 42 is combined with the corresponding second transmission gear 41 according to the information of the controller 60 and under the action of the locking structure to provide power assistance for the vehicle. Wherein, the electric control actuator 42 can be a synchronizer. The plurality of first transmission gears 30 are in one-to-one correspondence with the plurality of second transmission gears 42, and the plurality of first transmission gears 30 and the plurality of second transmission gears form a plurality of sets of gear sets, each set of gear sets including one first transmission gear 30 and one second transmission gear 42, the transmission ratio of each set of gear sets being different to output different torques through the output shaft 50.

And, the controller 60 is electrically connected to the drive motor 20, the controller 60 being configured to: the controller 60 controls the driving motor 20 to start according to the rotation angle signal, the torque signal, the engine rotation speed signal and the vehicle speed signal transmitted from the steering wheel end, the driving motor 20 drives the plurality of first transmission gears 30 of the input shaft 10 to rotate, and the controller 60 controls the electric control actuator 42 to engage the second transmission gears 41 with the torsion bar shaft 40 so as to drive the output shaft 50 to rotate. That is, the controller 60 may acquire signals, such as a rotation angle signal, a torque signal, an engine rotation speed signal, a vehicle speed signal, etc., through the input shaft 10 in driving connection with the steering wheel, and process the signals to control the driving motor 20 to start, the driving motor 20 drives the plurality of first transmission gears 30 of the input shaft 10 to rotate, the electric control actuator 42 engages the corresponding second transmission gears with the torsion bar shaft 40 according to the information processed by the controller 60, and the output shaft 50 is in driving connection with the torsion bar shaft 40, so that the output shaft 50 rotates and outputs corresponding torque values and rotation angle values.

Thus, the controller 60 may control the electric control actuator 42 to engage the corresponding second transmission gear 41 with the torsion bar shaft 40 according to the signal obtained by the sensor, so that the output shaft 50 outputs the corresponding torque value and the rotation angle value. When the vehicle state is identified to require a large torque, the motor can provide a large torque to sacrifice rotational speed to obtain a larger torque, and when the vehicle state is identified to require a small torque, the motor can provide a small torque, so that power is not lost, and the power of the motor is utilized to the maximum.

As shown in fig. 1, the number of gear sets is three, that is, the first transmission gears 30 are three, the second transmission gears 42 are three, and the three first transmission gears 30 and the three second transmission gears 42 constitute three gear sets to output different torques through the output shaft 50.

Wherein, when the controller 60 recognizes that the vehicle speed is 0-20km/h and the engine speed is 0-1500r/min, the electric control actuator 42 is connected with one of the second transmission gears 41, and the output shaft 50 can output three-level torque: 7300N.m to meet the power assist required for in-situ steering and low speed travel; when the controller 60 recognizes that the vehicle speed is 20-60km/h and the engine speed is 1500-2000r/min, the electric control actuator 42 is connected with the other second transmission gear 41, and the output shaft 50 can output the secondary torque: 5100N.m to meet the assistance required for medium speed driving; when the controller 60 recognizes that the vehicle speed is 20-60km/h and the engine speed is 2000-2500r/min, the electric control actuator 42 is connected with the second transmission gear 41, and the output shaft 50 can output primary torque: and 3500N.m to meet the assistance required for high-speed running.

And, the transmission ratios of the three sets of gear sets are i1, i2 and i3, respectively, and i1, i2 and i3 satisfy the relation: i1 is more than or equal to 22.5 and less than or equal to 23.5, i2 is more than or equal to 19.5 and less than or equal to 21.5, and i1 is more than or equal to 17.5 and less than or equal to 18.5. That is, the three sets of gear sets have three gear ratios, i1, i2, and i3, respectively, wherein one set of gear sets has a gear ratio i1, and the gear ratio ranges from 22.5 to 23.5, such that the output shaft 50 can output three levels of torque: 7300n.m; the other set of gear sets has a gear ratio i2, which ranges from 19.5 to 21.5, such that the output shaft 50 can output a secondary torque: 5100n.m; the gear ratio of the other set of gears is i3, the range of gear ratios is between 17.5 and 18.5, so that the output shaft 50 can output primary torque: 2500 n.m.

In addition, as shown in fig. 3, the controller 60 has a power assist mode in which the controller 60 is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller 60, the controller 60 obtains a power-assisted torque value according to the steering wheel angle value, the torque value and the vehicle speed signal, the power-assisted torque value is transmitted to the driving motor 20, and the driving motor 20 outputs a corresponding power-assisted torque value. Specifically, when the power mode is ign_on, under the condition that the electric power steering device 100 has no fault, the electric power steering device 100 enters a power-assisted mode, a driver applies torque to the steering wheel to rotate the steering wheel, the input shaft 10 is in transmission connection with the steering wheel, a sensor at the input shaft 10 detects torque change and the current angle value of the steering wheel, meanwhile, the sensor also detects vehicle speed information, a torque signal, a vehicle speed signal and an angle signal are transmitted to the controller 60 for processing, and the controller 60 selects a proper power-assisted curve according to the current steering wheel angle value, the detected torque value and the vehicle speed signal for calculation, so that the needed power-assisted torque value is obtained. And transmits the assist torque value to the driving motor 20, and the driving motor 20 outputs a corresponding assist torque value to assist the output shaft 50.

When the power mode is switched to non ign_on or the electric power steering apparatus 100 fails, the electric power steering apparatus 100 exits the assist mode.

And, as shown in fig. 3, the controller 60 also has a return mode in which the controller 60 is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller 60, the controller 60 obtains a positive torque value according to the steering wheel angle value, the torque value and the vehicle speed signal, and sends the positive torque value to the driving motor 20, and the driving motor 20 outputs a corresponding positive torque value. Specifically, when the power mode is ign_on, in the case where the electric power steering apparatus 100 has no fault and the vehicle is traveling forward, the electric power steering apparatus 100 enters a return mode, that is, when the vehicle is traveling forward, the driver applies a torque to the steering wheel to rotate the steering wheel, the input shaft 10 is in driving connection with the steering wheel, the sensor at the input shaft 10 detects a torque change and an angle value at which the steering wheel is currently located, and at the same time, the sensor also detects a vehicle speed signal, and transmits the torque signal, the vehicle speed signal and the angle signal to the controller 60 for processing, the controller 60 calculates a return torque value according to the steering wheel angle value, the torque value, the vehicle speed signal, and the like, and transmits the return torque value to the driving motor 20, and the driving motor 20 outputs a corresponding return torque value, thereby applying a return torque to the output shaft 50.

When the power mode is switched to the non-ign_on, or when the electric power steering apparatus 100 is out of order, or when the vehicle speed is zero, the electric power steering apparatus 100 exits the return mode.

Further, as shown in fig. 3, the controller 60 has a damping compensation mode in which the controller 60 is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller 60, the controller 60 obtains a damping compensation torque value according to the steering wheel angle value, the torque value and the vehicle speed signal, the damping compensation torque value is transmitted to the driving motor 20, and the driving motor 20 outputs a corresponding damping compensation torque value. Specifically, when the power mode is ign_on, the electric power steering device 100 enters the damping compensation mode under the conditions that the electric power steering device 100 has no fault and the vehicle runs at a high speed, that is, when the vehicle runs at a high speed, the sensor at the input shaft 10 detects the torque change and the angle value at which the steering wheel is currently positioned, and simultaneously the sensor also detects the vehicle speed signal, the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller 60 for processing, the controller 60 calculates the damping compensation torque value according to the steering wheel angle value, the torque value, the vehicle speed signal and the like, and transmits the damping compensation torque value to the driving motor 20, and the driving motor 20 outputs the corresponding damping compensation torque value to apply the damping compensation torque to the input shaft 10.

When the power mode is switched to the non-ign_on, or when the electric power steering apparatus 100 is out of order, or when the vehicle speed is zero, the electric power steering apparatus 100 exits the damping compensation mode.

Still further, as shown in fig. 3, the controller 60 has a friction compensation mode in which the controller 60 is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller 60, the controller 60 obtains a friction compensation torque value according to the steering wheel angle value, the torque value and the vehicle speed signal, and transmits the friction compensation torque value to the driving motor 20, and the driving motor 20 outputs a corresponding friction compensation torque value. Specifically, when the power mode is ign—on, in the case where the electric power steering apparatus 100 has no fault, the electric power steering apparatus 100 enters a friction compensation mode, that is, the sensor at the input shaft 10 detects a torque change and an angle value at which the steering wheel is currently located, and at the same time, the sensor also detects a vehicle speed signal, the torque signal, the vehicle speed signal, and the angle signal are transmitted to the controller 60 for processing, the controller 60 calculates a friction compensation torque value according to the steering wheel angle value, the torque value, the vehicle speed signal, and the like, and transmits the friction compensation torque value to the driving motor 20, and the driving motor 20 outputs a corresponding friction compensation torque value to apply a friction compensation torque to the input shaft 10.

When the power mode is switched to the non ign_on or when the electric power steering apparatus 100 has a failure, the electric power steering apparatus 100 exits the friction compensation mode.

In addition, as shown in fig. 3, the controller 60 has an auxiliary compensation mode in which the controller 60 is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller 60, the controller 60 obtains an auxiliary compensation torque value according to the steering wheel angle value, the torque value and the vehicle speed signal, and transmits the auxiliary compensation torque value to the driving motor 20, and the driving motor 20 outputs a corresponding auxiliary compensation torque value. Specifically, when the power mode is ign_on, after the electric steering gear 100 enters the friction compensation mode, the sensor at the input shaft 10 detects a torque change and the current angle value of the steering wheel, and at the same time, the sensor also detects a vehicle speed signal, the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller 60 for processing, the controller 60 calculates an auxiliary compensation torque value according to the steering wheel angle value, the torque value, the vehicle speed signal and the like, and transmits the auxiliary compensation torque value to the driving motor 20, and the driving motor 20 outputs a corresponding auxiliary compensation torque value to apply an auxiliary compensation torque to the output shaft 50.

Wherein the controller 60 is further configured to: the controller 60 enters the auxiliary compensation mode when the vehicle deviates in the traveling direction due to road surface or crosswind or the like; and/or the controller 60 enters the auxiliary compensation mode when the vehicle is deviated in the traveling direction due to the asymmetry of the suspension, the abrasion of the tire, and the like; and/or the controller 60 enters the auxiliary compensation mode when a deviation of the traveling direction occurs under the sudden acceleration/deceleration condition of the vehicle. Specifically, the auxiliary compensation modes are divided into three modes, namely a lateral disturbance compensation mode, a deviation compensation mode and a torque compensation mode.

In short, when the power mode is ign_on, the electric power steering device 100 enters the lateral disturbance compensation mode in the case that the electric power steering device 100 has no fault and the vehicle is traveling straight forward, that is, the vehicle may deviate in the traveling direction due to road bump or lateral wind, and the controller 60 may calculate the auxiliary compensation torque value according to the yaw rate, the vehicle speed, the steering wheel torque, and other signals to correct, and send the auxiliary compensation torque value to the driving motor 20, and the driving motor 20 outputs the corresponding auxiliary compensation torque value to apply the auxiliary compensation torque value to the output shaft 50.

At this time, when the power mode is switched to the non ign_on, or when the electric power steering apparatus 100 has a failure, or when the vehicle speed is zero, or when the steering wheel angle sensor is unchanged, the electric power steering apparatus 100 exits the side disturbance compensation mode.

Alternatively, when the power mode is ign_on, in the case where the electric power steering apparatus 100 is not faulty and the vehicle is traveling straight forward, the electric power steering apparatus 100 enters the deviation compensation mode, that is, when the vehicle is traveling straight forward, the vehicle may deviate in the traveling direction due to the asymmetry of the suspension, the abrasion of the tire, etc., and the controller 60 may calculate the auxiliary compensation torque value according to the signals of the longitudinal acceleration, the vehicle speed, the steering wheel angle, etc., correct the auxiliary compensation torque value, and transmit the auxiliary compensation torque value to the driving motor 20, and the driving motor 20 outputs the corresponding auxiliary compensation torque value to apply the auxiliary compensation torque value to the output shaft 50.

At this time, when the power mode is switched to the non ign_on, or when the electric power steering apparatus 100 has a failure, or when the vehicle speed is zero, the electric power steering apparatus 100 exits the deviation compensation mode.

Alternatively, when the power mode is ign—on, if the electric power steering apparatus 100 is not in failure and the vehicle is rapidly accelerating or decelerating, the electric power steering apparatus 100 enters the torque compensation mode, that is, if the vehicle is rapidly accelerating or decelerating, the running direction may deviate, the controller 60 may calculate the auxiliary compensation torque value according to the wheel speed difference, the longitudinal acceleration, or the like, correct the auxiliary compensation torque value, send the auxiliary compensation torque value to the driving motor 20, and the driving motor 20 outputs a corresponding auxiliary compensation torque value to apply the auxiliary compensation torque value to the output shaft 50.

At this time, when the power mode is switched to the non ign_on, or when the electric power steering apparatus 100 has a failure, or when the longitudinal acceleration is zero, the electric power steering apparatus 100 exits the torque compensation mode.

In addition, as shown in fig. 3, the controller 60 has a protection mode in which the controller 60 is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller 60, the controller 60 obtains a reduction power assisting signal according to the steering wheel angle value, the torque value and the vehicle speed signal, and the controller 60 controls the driving motor 20 to output a corresponding torque value according to the reduction power assisting signal. That is, when the power mode is ign_on, after the electric power steering apparatus 100 enters the protection mode, the sensor at the input shaft 10 detects the torque change and the current angle value of the steering wheel, and at the same time, the sensor also detects the vehicle speed signal, and transmits the torque signal, the vehicle speed signal and the angle signal to the controller 60 for processing, the controller 60 obtains the power-reducing signal according to the steering wheel angle value, the torque value and the vehicle speed signal, and the controller 60 controls the driving motor 20 to output the corresponding torque value according to the power-reducing signal, and applies the torque to the output shaft 50.

Wherein the controller 60 is further configured to: the controller 60 enters a protection mode when the steering wheel is turned near the limit position; and/or the controller 60 enters a protection mode when the controller 60 is providing an over-voltage or under-voltage power; and/or the controller 60 enters the protection mode when the steering angle and the steering torque are abnormal. That is, the protection mode includes three cases, the first is an end protection or soft dead center protection mode, the second is an overload protection or dead center protection mode, and the third is an overvoltage or undervoltage protection mode.

Specifically, when the power mode is ign_on, and the electric power steering device 100 is in the end protection mode or the soft dead center protection mode when the steering wheel is rotated near the limit position without any trouble, that is, when the steering wheel is rotated near the limit position, the controller 60 acquires a power-down signal according to the steering wheel angle value, the torque value, and the vehicle speed signal, and the controller 60 controls the driving motor 20 to output a corresponding torque value according to the power-down signal, thereby avoiding the impact ON the machine.

At this time, when the power mode is switched to the non ign_on, or when the electric power steering apparatus 100 has a failure, or when the vehicle speed is zero, or when the steering wheel is turned out of the vicinity of the limit position, the electric power steering apparatus 100 exits the end protection mode or the soft dead center protection mode.

Or, when the power mode is ign_on, in the case that the electric power steering device 100 has no fault and the steering angle and the steering torque are abnormal, the electric power steering device 100 enters an overload or dead point protection mode, that is, when the steering angle and the steering torque of the steering wheel are in abnormal states, the controller 60 judges whether to enter an overload state according to the steering wheel angle value, the torque value and the vehicle speed signal, if entering the overload state, the controller 60 obtains a power reduction signal, the calculated torque value is sent to the driving motor 20, the driving motor 20 outputs a corresponding torque value, the power is reduced, and the damage to the motor caused by continuous heavy current output is avoided.

At this time, when the power mode is switched to the non ign_on, or when the electric power steering apparatus 100 has a failure, or when the steering angle and the steering torque are normal, the electric power steering apparatus 100 exits the overload or dead center protection mode.

Or, when the power mode is ign_on, the electric power steering device 100 enters an overvoltage or undervoltage protection mode under the condition that the electric power steering device 100 has no fault and the power supply voltage of the controller 60 exceeds the limit, that is, when the power supply voltage of the controller 60 is too high or too low, the controller 60 judges whether to enter an overvoltage or undervoltage state according to the power supply voltage state of the controller 60, if entering the overvoltage or undervoltage state, the controller 60 obtains a power-reducing signal, the calculated torque value is sent to the driving motor 20, the driving motor 20 outputs a corresponding torque value, power-reducing is performed, and hardware damage is avoided.

At this time, when the power supply mode is switched to non ign_on, or when the electric power steering apparatus 100 has a failure, or when the power supply voltage of the controller 60 is normal, the electric power steering apparatus 100 exits the overvoltage or undervoltage protection mode.

Referring to fig. 1, the electric power steering apparatus 100 further includes: the rotation angle sensor 12 and the torque sensor 11, the rotation angle sensor 12 and the torque sensor 11 are disposed on the input shaft 10, and the rotation angle sensor 12 and the torque sensor 11 are electrically connected with the controller 60, the torque sensor 11 is used for detecting torque variation, and the rotation angle sensor 12 is used for detecting an angle value of the steering wheel. The rotation angle sensor 12 and the torque sensor 11 are located at the input shaft 10, and detect an angle value and a torque change of a steering wheel of the steering wheel through the input shaft 10.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. An electric power steering apparatus (100), characterized by comprising:

a drive motor (20);

the input shaft (10) is in transmission connection with the steering wheel and the driving motor (20), and a plurality of first transmission gears (30) are arranged on the input shaft (10);

the torsion bar shaft (40), a plurality of second transmission gears (41) and a plurality of electric control actuators (42) are arranged on the torsion bar shaft (40), the electric control actuators (42) and the second transmission gears (41) are in one-to-one correspondence, the electric control actuators (42) are used for meshing the second transmission gears (41) with the torsion bar shaft (40), the first transmission gears (30) and the second transmission gears (41) are in one-to-one correspondence and form a plurality of groups of gear sets, and the transmission ratio of each group of gear sets is different;

an output shaft (50), wherein the output shaft (50) is in transmission connection with the torsion bar shaft (40);

a controller (60), the controller (60) being electrically connected to the drive motor (20) and the electrically controlled actuator (42), the controller (60) being configured to: the controller (60) controls the driving motor (20) to start according to a rotation angle signal, a torque signal, an engine rotation speed signal and a vehicle speed signal transmitted from the steering wheel end, the driving motor (20) drives the plurality of first transmission gears (30) of the input shaft (10) to rotate, and the controller (60) controls the electric control actuator (42) to engage the second transmission gears (41) with the torsion bar shaft (40) so as to drive the output shaft (50) to rotate.

2. The electric power steering gear (100) according to claim 1, wherein the gear sets are three sets.

3. The electric power steering gear (100) according to claim 2, wherein the gear ratios of three sets of said gear sets are i1, i2 and i3, respectively, i1, i2 and i3 satisfying the relation: i1 is more than or equal to 22.5 and less than or equal to 23.5, i2 is more than or equal to 19.5 and less than or equal to 21.5, and i1 is more than or equal to 17.5 and less than or equal to 18.5.

4. The electric power steering gear (100) according to claim 1, wherein the controller (60) has a power assist mode in which the controller (60) is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller (60), the controller (60) obtains a power-assisted torque value according to the steering wheel angle value, the torque value and the vehicle speed signal, the power-assisted torque value is transmitted to the driving motor (20), and the driving motor (20) outputs a corresponding power-assisted torque value.

5. The electric power steering gear (100) according to claim 1, wherein the controller (60) has a return mode in which the controller (60) is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller (60), the controller (60) obtains a positive torque value according to the steering wheel angle value, the torque value and the vehicle speed signal, the positive torque value is transmitted to the driving motor (20), and the driving motor (20) outputs a corresponding positive torque value.

6. The electric power steering gear (100) according to claim 1, wherein the controller (60) has a damping compensation mode in which the controller (60) is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller (60), the controller (60) obtains a damping compensation torque value according to the steering wheel angle value, the torque value and the vehicle speed signal, the damping compensation torque value is transmitted to the driving motor (20), and the driving motor (20) outputs a corresponding damping compensation torque value.

7. The electric power steering gear (100) according to claim 1, wherein the controller (60) has a friction compensation mode in which the controller (60) is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller (60), the controller (60) obtains a friction compensation torque value according to the steering wheel angle value, the torque value and the vehicle speed signal, the friction compensation torque value is transmitted to the driving motor (20), and the driving motor (20) outputs a corresponding friction compensation torque value.

8. The electric power steering gear (100) according to claim 1, wherein the controller (60) has an auxiliary compensation mode in which the controller (60) is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller (60), the controller (60) obtains an auxiliary compensation torque value according to the steering wheel angle value, the torque value and the vehicle speed signal, the auxiliary compensation torque value is transmitted to the driving motor (20), and the driving motor (20) outputs a corresponding auxiliary compensation torque value.

9. The electric power steering gear (100) according to claim 7, wherein the controller (60) has a protection mode in which the controller (60) is further configured to: the torque signal, the vehicle speed signal and the angle signal are transmitted to the controller (60), the controller (60) obtains a reduced power assisting signal according to the steering wheel angle value, the torque value and the vehicle speed signal, and the controller (60) controls the driving motor (20) to output a corresponding torque value according to the reduced power assisting signal.

10. The electric power steering gear (100) according to any one of claims 1 to 9, further comprising: the steering device comprises a rotation angle sensor (12) and a torque sensor (11), wherein the rotation angle sensor (12) and the torque sensor (11) are arranged on an input shaft (10) and are electrically connected with a controller (60), the torque sensor (11) is used for detecting torque change, and the rotation angle sensor (12) is used for detecting an angle value of a steering wheel.