CN1978265B - Steering angle transmission ratio adjustable steering system - Google Patents

Abstract

The invention discloses a steering system with adjustable steering angle transmission ratio, which comprises a steering column for driving the rotation of the steering wheel and a steering gear for controlling the wheel angle, and an angle transmission ratio adjustment is arranged between the steering column and the steering gear The mechanism also includes a control device, and the control device is used to control the transmission ratio of the angular transmission ratio adjustment mechanism to be greater than 1 at low speed and smaller than 1 at high speed. The invention realizes the requirement of sensitive steering of the vehicle at low speed and the stability of the vehicle at high speed. And according to the real-time vehicle speed signal and engine speed signal, the angular transmission ratio of the control steering system is steplessly adjustable.

Description

Steering system with adjustable steering angle transmission ratio

【Technical field】

The invention relates to a steering system of an automobile, in particular to a steering system capable of adjusting the angular transmission ratio of the steering system to realize optimal control of the vehicle. the

【Background technique】

The steering system is an important part of the chassis system of the car. Its function is to control the wheels to rotate at a certain angular transmission ratio according to the rotation of the steering wheel, thereby controlling the steering of the vehicle. Therefore, the steering system is related to the handling stability of the vehicle and the safety of driving. the

The angular transmission ratio of most existing steering systems is not adjustable, that is, after the design of the steering system is completed, the steering angular transmission ratio is also fixed. With the continuous progress and development of modern automobile technology, such a steering system can no longer meet the requirements of modern vehicles for low-speed steering sensitivity and high-speed stability. The wheel angle means that the angular transmission ratio of the steering system is expected to be small; while at high speeds, it is hoped that the angular transmission ratio should not be too small, so as to avoid a slight steering wheel rotation causing the car to deviate a lot from the track. the

Now there is also a steering gear with variable transmission ratio. The principle is to realize different steering angles with different steering angle transmission ratios by processing teeth with variable modulus on the rack. However, the processing technology of this rack is relatively Difficult. In addition, the steering gear equipped with a variable modulus rack only realizes that the vehicle has different steering angle transmission ratios under different wheel angle conditions (such as when the wheel angle is small—that is, when it is close to the straight-line driving condition of the vehicle, the steering The angular transmission is relatively large to ensure the stability of straight-line driving. When the wheel rotation angle is large, the steering angle transmission is relatively small, so this steering gear does not fundamentally solve the requirements for sensitive steering at low speeds and driving stability at high speeds.

【Content of invention】

The main purpose of the present invention is to provide a steering system with adjustable steering angle transmission ratio in order to solve the problems of the prior art. At low speeds, the angular transmission ratio of the steering system is reduced to meet the requirements of sensitive steering of vehicles at low speeds. At high speed, increase the steering angle transmission ratio to meet the requirements for vehicle stability at high speed. the

The second purpose of the present invention is to provide a steering system with adjustable steering angle transmission ratio, which controls the angular transmission ratio of the steering system according to the vehicle speed and engine speed, so that the steering angle transmission ratio is steplessly adjustable. the

To achieve the above object, the present invention discloses a steering system with adjustable steering angle transmission ratio, which includes a steering column for driving the rotation of the steering wheel and a steering gear for controlling the wheel angle. The angular transmission ratio adjustment mechanism also includes a control device, and the control device is used to control the transmission ratio of the angular transmission ratio adjustment mechanism to be greater than 1 at low speeds and less than 1 at high speeds. Therefore, the angular transmission ratio of the steering system is less than 1 at low speeds and greater than 1 at high speeds. In this paper, the angular transmission ratio of the steering system refers to the ratio of the steering wheel's rotation angle to the steering knuckle's rotation angle on the same side, which is the relationship between input and output. The transmission ratio of the angular transmission ratio adjustment mechanism refers to the ratio of the angle that the output shaft turns to the angle that the input shaft turns, which is the relationship between the output ratio and the input. the

The angular transmission ratio adjustment mechanism includes a driving disc, a variable ratio transmission device and a driven disc. The input end of the driving disc is connected to the lower shaft of the steering column, and the output end is connected to the input of the driven disc through the variable ratio transmission device. The output end of the driven disc is connected to the input end of the steering gear, and the control device controls the variable ratio transmission device to output different transmission ratios. the

The preferred solution is: the driving disc and the driven disc face each other and are arranged along the same central axis, and their opposite sides are provided with an annular groove centered on the axis of the central axis, and the cross-sectional shape of the annular groove is a circle Arc shape; the variable ratio transmission device includes rollers, which are arranged between the annular grooves of the driving disc and the driven disc and are located on the same side of the central axis. the

The surfaces of the annular grooves and the rollers of the driving disc and the driven disc are rough surfaces; or the surfaces of the annular grooves and the rollers of the driving disc and the driven disc are provided with the same grooves. the

Wherein the preferred solution is: the size of the driving disc and the driven disc are equal, and the number of the rollers is two or three, which are evenly arranged between the annular grooves of the driving disc and the driven disc relative to the central axis. the

The variable ratio transmission device also includes a rotating shaft on which the roller is rotatable around its own axis, and the control device is used to control the rotation of the rotating shaft so that the roller has different inclinations in the annular grooves of the driving disc and the driven disc. horn. the

The control device includes a motor, the output of which is coupled to the shaft. the

Another improvement of the present invention is that the control device further includes a signal processing unit, the signal processing unit responds to the vehicle speed signal and the engine speed signal, and outputs a control signal to the motor after processing. the

The beneficial effects of the present invention are: 1) the program is provided with an angular transmission ratio adjustment mechanism between the steering column and the steering gear, and the angular transmission ratio adjustment mechanism can be controlled according to different vehicle speeds to have different transmission ratios. The transmission ratio of the angular transmission ratio adjustment mechanism is greater than 1, and a larger wheel angle can be obtained with a smaller steering wheel rotation, thereby realizing the requirement of sensitive steering of the vehicle at low speeds. At high speed, the angular transmission ratio of the angular transmission ratio adjustment mechanism is less than 1, and a smaller wheel angle can be obtained with a larger steering wheel rotation, so as to meet the requirements for vehicle stability at high speeds. 2) The signal processing unit controls the motor to rotate at a certain angle according to the real-time vehicle speed signal and engine speed signal, thereby controlling the inclination angle of the roller in the annular grooves of the driving disc and the driven disc, which can change the rotation of the roller in the two annular grooves of the master and slave. The distance from the contact point on the top to the central axis of the main and driven discs, thereby changing the angular transmission ratio. Because the inclination angle of the roller can be changed continuously, the angular transmission ratio can be adjusted steplessly. the

The features and advantages of the present invention will be described in detail with reference to the accompanying drawings. the

【Description of drawings】

Fig. 1 is the structural representation of the angular transmission ratio adjusting mechanism of a kind of embodiment of the present invention;

Fig. 2 is the installation schematic diagram of roller among Fig. 1;

Fig. 3 is a schematic diagram of a position where the transmission ratio of the angular transmission ratio adjustment mechanism of Fig. 1 is greater than 1;

Fig. 4 is a schematic diagram of the position where the transmission ratio of the angular transmission ratio adjustment mechanism of Fig. 1 is equal to 1;

FIG. 5 is a schematic diagram of the position of the angular transmission ratio adjustment mechanism in FIG. 1 where the transmission ratio is less than 1. FIG. the

【Detailed ways】

Embodiment 1. As shown in Figure 1, it is a schematic diagram of a mechanical roller type stepless angular transmission ratio adjustment mechanism. The driving disc 1 is connected to the lower shaft peripheral end of the steering column through the input shaft, and the driven disc 2 is output The shaft is connected to the steering gear input shaft. The input shaft, the driving disc 1, the driven disc 2 and the output shaft are installed along the same central axis 16, and the driving disc 1 and the driven disc 2 are equal in size. In order to make the driving disc 1 and the driven disc 2 coaxial and ensure the stability of rotation, the shaft of the driven disc 2 is inserted into the shaft core of the driving disc 1 and can rotate freely, or the shaft of the driven disc 2 is sleeved on the driving disc 1 off-axis and free to rotate. Annular grooves 101, 201 are respectively formed on opposite sides of the driving disk 1 and the driven disk 2, and the cross-sectional shape of the annular grooves 101, 201 is an arc shape. The variable ratio transmission device includes two rollers 3, 4 and two rotating shafts (i.e. upper shaft 5 and lower shaft 12), each roller is installed between the annular grooves 101, 201 of the driving disc 1 and the driven disc 2, but every None of the rollers intersects the central axis 16, that is, the rollers will not cross the central axis 16 from the annular groove 101 to the annular groove 201. The two rollers are installed symmetrically with respect to the central axis 16, and the surfaces of the rollers are in close contact with the surface of the annular groove. Of course, there can also be three or four rollers, which are evenly installed between the annular grooves 101, 201 of the driving disc 1 and the driven disc 2. Increasing the number of rollers can increase the transmission force between the main and driven discs, but too many rollers will increase the complexity and cost of the design, so it is better to have two or three rollers. As shown in FIG. 2 , the roller 3 is mounted on the upper shaft 5 through a needle bearing 6 and a stop ring 7 , so that the roller 3 can rotate around its own axis 3 a. The upper shaft input gear 8 is installed on the upper shaft 5 through a spline. When the upper shaft input gear 8 rotates, it drives the upper shaft 5 to rotate, and simultaneously drives the roller 3 to produce different inclinations along the axis of the upper shaft 5 . The roller 4 is installed on the lower shaft 12 in the same way, and is rotatable around its own axis 4a. The surface of the annular groove of the driving disc 1 and the driven disc 2, and the surfaces of the rollers 3 and 4 are rough surfaces, and the rollers 3 and 4 transmit the motion of the driving disc 1 to the driven disc 2 through friction; it also includes a shell and a compression spring 13 , one end of the compression spring 13 is against the shell, and the other end is against the outer side of the driven disc 2, the compression spring 13 moves together with the entire angular transmission ratio adjustment mechanism, relying on the elastic force of the compression spring 13, the driving disc 1 , rollers 3 and 4, and driven disc 2 are tightly pressed together to ensure the required frictional force for transmission torque. The roller can also transmit motion from the driving disc to the driven disc in other ways, such as processing the same groove on the contact surface between the roller and the driving disc, and transmitting the motion through the mutual engagement of the grooves. the

When the steering wheel is turned, the steering column drives the input shaft and the driving disc 1 to rotate around the central axis 16, and through the ring surface 101 on the driving disc 1, the rollers 3 and 4 are driven around their own axes 3a and 4 by the friction between them. 4a rotates by itself, thereby driving the driven disc 2 and the output shaft to rotate around the central axis. The driven disc 2 and the output shaft drive the steering gear to rotate again to realize the steering action. Changing the inclination angle of the rollers 3 and 4 can change the distance from the contact points of the rollers 3 and 4 on the main and slave annular grooves to the central axis 16, thereby changing the transmission ratio of the angular transmission ratio adjustment mechanism. As shown in Figure 3, it is the working condition that the transmission ratio is greater than 1, the contact points of the rollers 3 and 4 in the annular groove 101 are far away from the central axis 16, and the contact points in the annular groove 201 are close to the central axis 16, and the driving disc is smaller The rotation angle of the driven disc can obtain a larger rotation angle, so the transmission ratio in this state is greater than 1, which affects the entire steering system and reduces the angular transmission ratio of the steering system. As shown in FIG. 4 , the transmission ratio is equal to 1, and the contact points of the rollers 3 and 4 in the annular grooves 101 and 102 are at the same distance from the central axis 16 . As shown in FIG. 5 , the transmission ratio is less than 1. The contact points of the rollers 3 and 4 in the annular groove 101 are close to the central axis 16 , and the contact points in the annular groove 201 are far away from the central axis 16 . the

The control device includes a signal processing unit and a motor. The signal processing unit can be realized by a vehicle-mounted computer. In order to realize the stepless adjustment of the angular transmission ratio, the vehicle-mounted computer controls the rotation direction and rotation angle of the motor 11 according to the vehicle speed signal and the engine speed signal. The rotary motion is coupled to the input gear 8 of the upper shaft, which in turn drives the input gear 10 of the lower shaft. The driving of the input gear 8 by the motor 11 can be that the driving gear 15 of the motor 11 directly meshes with the input gear 8, or can be driven by a gear, for example, the driving gear 15 of the motor transmits on the driven gear 14 meshed with it, and the driven gear 14 and The pinion 9 is installed on the same shaft, and the speed of the two is the same, and then the motion is transmitted to the input gear 8 of the upper shaft and the input gear 10 of the lower shaft through the pinion 9, the driven gear 14, the driving gear 15 of the motor and the input gear 8 of the upper shaft The transmission ratio between pinion 9 and pinion 9 is greater than 1, so as to realize the deceleration and torque increase of the motor. The upper shaft input gear 8 and the lower shaft input gear 10 have the same number of teeth, so as to ensure that the upper shaft 5 and the lower shaft 12 have the same rotation angle. It is transmitted to the upper shaft input gear 8 and the lower shaft input gear 10, and the two gears drive the upper shaft 5 and the lower shaft 12 to rotate around their axes respectively, so that the rollers 3 and 4 have an inclination angle, and the transmission ratio between the input shaft and the output shaft is changed. Thereby changing the angular transmission ratio of the steering system. For example, when the vehicle speed is low, the on-board computer controls the rotation angle and steering of the motor 11 to make the rollers 3 and 4 reach the state in Fig. 3, which reduces the angular transmission ratio of the steering system and makes the vehicle turn more flexibly at low speeds. When the vehicle speed is high, the on-board computer controls the angle of rotation and steering of the motor 11 to make the rollers 3 and 4 reach the state in Fig. 5, which increases the angular transmission ratio of the steering system and makes the vehicle more stable when running at high speed. the

In the foregoing embodiment, the rotation of the motor 11 is coupled to the upper shaft 5 and the lower shaft 12 and can also be driven by a belt. the

Embodiment 2. The angular transmission ratio adjustment mechanism includes a driving disc and a driven disc. The driving disc is connected to the lower shaft peripheral end of the steering column through the input shaft, and the driven disc is connected to the input shaft of the steering gear through the output shaft. The driving disk is a disk with the same diameter, and the driven disk includes three kinds of transmission disks whose diameter is larger, equal to or smaller than the diameter of the driving disk. Using the principle of the gearbox, the control device controls one of the driven disks with three diameters to pass through the driving disk. Gear meshing or belt driving to achieve an adjustable transmission ratio. the

The control device in the second embodiment can also be just a simple control, and three button switches can be set on the automobile operation panel, respectively, the transmission ratio is greater than 1, equal to 1 and less than 1, respectively for the steering system at low speeds. Small angular transmission ratio, normal angular transmission ratio and high angular transmission ratio of the steering system at high speed. When one of the three switches is pressed, the switch generates a level signal to the control device, which controls the angular transmission ratio adjustment mechanism to provide the corresponding transmission ratio. The transmission ratio of the angular transmission ratio adjusting mechanism in this way is not steplessly adjustable. the

Claims (6)

1. A steering system with adjustable steering angle transmission ratio, comprising a steering column for driving the steering wheel and a steering gear for controlling the wheel angle, an angular transmission ratio adjustment mechanism and control device, the angular transmission ratio adjustment mechanism includes a driving disc, a variable ratio transmission device and a driven disc, the input end of the driving disc is connected to the lower shaft of the steering column, and the output end is connected to the driven disc through a variable ratio transmission device The input end of the disk is connected, and the output end of the driven disk is connected with the input end of the steering gear. The driving disk and the driven disk are arranged along the same central axis facing each other, and the opposite sides are all opened with the central axis The shaft center of the circular groove is the circular groove, and the cross-sectional shape of the circular groove is an arc shape; the variable ratio transmission device includes rollers, and the rollers are arranged between the annular grooves of the driving disc and the driven disc, and the control The device is used to control the angular transmission ratio adjustment mechanism. The transmission ratio is greater than 1 at low speed and less than 1 at high speed. The key is installed on the upper shaft input gear of the upper shaft, and the upper shaft and the lower shaft are respectively equipped with rollers, and the rollers can rotate around their own axes. The control device includes a motor, and the motor is rotationally coupled to the upper shaft The input gear, the upper shaft input gear drives the lower shaft input gear, and the motor drives the upper shaft and the lower shaft to rotate so that the rollers have different inclination angles between the annular grooves of the driving disc and the driven disc. 2. The steering system according to claim 1, characterized in that: the surfaces of the annular grooves of the driving disc and the driven disc, and the surfaces of the rollers are rough surfaces. 3. The steering system according to claim 2, further comprising a casing and a compression spring, one end of the compression spring abuts against the casing, and the other end abuts against the outer side of the driven disk. 4. The steering system according to claim 1, characterized in that: the annular groove surfaces and the roller surfaces of the driving disc and the driven disc are provided with the same grooves. 5. The steering system according to claim 1, characterized in that: the size of the driving disc and the driven disc are equal, the number of the rollers is two or three, and they are evenly arranged on the driving disc and the driven disc with respect to the central axis. between the annular grooves of the disc. 6. The steering system according to claim 1, wherein the control device further comprises a signal processing unit, the signal processing unit responds to the vehicle speed signal and the engine speed signal, outputs a control signal to the motor after processing. the

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