JPH02246874A - Rear wheel steering gear - Google Patents

Abstract

PURPOSE:To enable the most appropriate steering corresponding to the running condition of a vehicle by connecting a controller for controlling the output of the first and second power source individually according to the running condition of the vehicle to the first and second power source. CONSTITUTION:When a first and a second motors 25, 26 are rotated by the command of a controller 35 in both steering gears Sr, Sl, the rotational force is transmitted to rods 28 through the engagement between worms 27 and racks 28a, and the rods 28 are shifted either to the right or to the left in the drawing. When the rods 28 are shifted, oscillating link members 32 are oscillated either clockwise or anticlockwise with supporting members 30 as fulcrums, arms 33 connected to the members 32 are shifted in either one of the directions of an arrow (Y). Rear wheels 23, 24 mounted at connecting members 34 are thus steered individually. That is to say, the braking state, backing state and throttle opening information of a vehicle are inputted into the controller 35, and rear wheel steering angles can be controlled individually according to the acceleration/deceleration and proceeding direction of the vehicle.

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention connects individual steering devices to the left and right rear wheels, controls the steering angles of the left and right rear wheels individually, and maintains the vehicle under optimal conditions. The present invention relates to a rear wheel steering device that allows steering by using the steering wheel.

(Prior Art) The conventional rear wheel steering device shown in FIG.
It is connected to side rod 3.4.

When the handle 1 is turned, the handle 1a rotates together with the handle 1, and this rotational force is transmitted through the engagement between the rack and the binion of the front wheel steering device 2.
It is transmitted to the side rod 3.4. The side rod 3.4 moves in either the left or right direction in the drawing, and steers the front wheel 7.8 via a knuckle arm 5.6 connected to the side rod 3.4.

In addition, a rear wheel steering device 9 is provided separately from the front wheel steering device 2, and this rear wheel steering device 9 includes a motor 10, a shaft driver 11 linked to the motor IO, and a shaft driver 11 that is directly connected to the motor 10. The main elements are an encoder 12 and an electromagnetic brake 13. The output shaft (not shown) of the motor 1O is linked to a shaft (not shown) of the shaft driver 11, and side rods 14, 15 are connected to both ends of this shaft, respectively.

When the motor IO rotates, this rotational force is transmitted to the side rod 14.15 via the shaft driver 11. The rotational force of the motor 10 is applied to the side rod 14.
15, the side rod 14.15 moves to either the left or right direction in the drawing, and also moves the rear wheel 18.19 via the knuckle arm 16.17 connected to this side rod 14.15. Turn the wheel.

The steering device 9 configured in this manner has its motor lO
and an electromagnetic brake 1.3 are connected to a controller 20, and a vehicle speed sensor 21 is connected to this controller 20.
, a surface width steering angle sensor 22 provided on the side rod 4 of the front wheel.
and encoder 12 are connected.

When the steering wheel 1 is turned and the front wheels 7.8 are steered, the front wheel steering angle sensor 22 detects the actual front wheel steering angle, the vehicle speed sensor 21 detects the actual vehicle speed, and these output signals are sent to the controller. Enter 20.

The motor IO rotates according to the input signal.

Further, when the motor IO rotates, the encoder 12 detects the actual rotation amount of the motor IO, and feeds back this output signal to the controller 20 to perform feedback control of the rear wheel steering angle.

That is, in this rear wheel steering device, the rear wheels 18 and 19 are both connected to a single rear wheel steering device 9 to which the motor 10 is linked, and the rotational force of the motor IO controlled by the controller 20 is transferred to the rear wheels 18 and 19. .19 to control the steering of the rear wheels 18.19.

Therefore, both the left and right rear wheels 18 and 19 are steered in the same direction and by the same angle. In this way, the left and right rear wheels are steered in the same manner, so when the vehicle speed is low, the front and rear wheels can be steered in opposite phases, and when the vehicle speed is high, they can be steered in the same phase, but it is not possible to steer both the left and right rear wheels individually. I can't.

(Problems to be Solved by the Present Invention) The conventional rear wheel steering device as described above cannot steer both the left and right rear wheels individually, so the steering angle of the rear wheels is adjusted to the optimum state according to the driving conditions. cannot be controlled.

Therefore, there is a problem in that the vehicle cannot be steered under optimal conditions depending on the driving conditions of the vehicle.

An object of the present invention is to provide a rear wheel steering device that can perform optimal steering according to the driving conditions of a vehicle.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a steering device that steers rear wheels using power from a power source such as a motor, and a steering device that steers rear wheels using power from a power source such as a motor, and a steering device that steers rear wheels using power from a power source such as a motor. In the rear wheel steering device provided with a controller for controlling the output of the power source,
A trapezoidal link unit is provided, a swinging link member is connected to one side of one arm of the first and second trapezoidal link units, one side of the other arm is fixed, and a connecting member is connected to the other side of both arms. A rear wheel is attached to this connecting member to form a first and second steering device, and a first power source is linked to a swinging link member of the first steering device, and a swinging link member of the second steering device is connected to the swinging link member of the second steering device. The structure is such that the second power source is linked to the second power source, and the swinging link member is swung according to the output of the first and second power sources, and the output of the first and second power source is adjusted according to the driving conditions of the vehicle. The configuration is such that a controller for individual control is connected to the first and second power sources.

(Action of the present invention) As described above, a steering device in which a power source such as a motor is linked is individually connected to both left and right rear wheels via its trapezoidal link unit, and the output of the office power source is transmitted by a controller. Since they are controlled individually, the steering angles of both the left and right rear wheels can be controlled individually.

(Effects of the Present Invention) According to the rear wheel steering device of the present invention, both the left and right rear wheels can be controlled individually.

Therefore, the steering angles of the left and right rear wheels can be made different, and both the left and right rear wheels can be steered toward the toe-in side or toward the toe-out side.

Furthermore, by inputting information on the brake state, reverse state, and throttle opening of the vehicle into the controller, the rear wheel turning angle can be individually controlled according to the acceleration/deceleration and traveling direction of the vehicle.

Therefore, the vehicle can be steered under optimal conditions depending on the driving conditions of the vehicle.

(Embodiment of the present invention) In the first embodiment of the present invention shown in Fig. 1.2, a first steering device Sr and a second steering device Sft are connected to the left and right rear wheels 23 and 24, respectively. .

The above-mentioned 1.2 steering devices Sr, Su have 1st and 2nd steering devices.
Motors 25 and 26 are provided, and a worm 27 is attached to the output shafts 25a and 26a of the first and second motors 25 and 26, respectively. Further, the worm 27 is the first
．． The rods 28 are engaged with the racks 28a of the rods 28 provided in the two steering devices Sr%SJ2, respectively.

Then, the rotational force of the first and second motors 25 and 26 is applied to the first and second motors through the engagement between the worm 27 and the rack 28a.
The information is transmitted to the two trapezoidal link units A and B, but since the configurations of both the first and second trapezoidal link units A and B are the same, each trapezoidal link unit A and B is transmitted to the first and second trapezoidal link units A and B shown in FIG. The trapezoidal link unit A will be described with reference to the same reference numerals.

The first trapezoidal link unit A shown in FIG.
Support members 29 and 30 are provided at the support member 29 and one side of the arm 31 is fixed to the support member 29, and a swing link member 32 is swingably attached to the support member 30.

Further, one end of the swing link member 32 is connected to the rod 2.
8, and an arm 33 at the other end.
One side is rotatably connected. Then, the connecting member 34 is passed over the other side of the arms 31 and 33, and the arm 3
3 and a connecting member 34 are swingably connected to each other, and rear wheels 23 and 24 are respectively attached to this connecting member 34.

In both the steering devices Sr and S2 configured as described above, when the first and second motors 25 and 26 rotate, the rotational force is transmitted to the rod 2 through the engagement between the worm 27 and the rack 28a.
8, and the rod 28 moves in either the left or right direction in the drawing. When the rod 28 moves, the swing link member 3
2 swings clockwise or counterclockwise in the drawing with the support member 30 as a fulcrum, and the arm 33 connected to the swinging link member 32 moves in either direction of the arrow y in the drawing. The rear wheel 23 attached to the connecting member 34.
24 are steered individually.

1.2 steering device Sr, SI as described above
L connects these 1.2 motors 25, 26 to the controller 35. On the other hand, the front wheel steering angle sensor 22 provided on the side rod 4 on the front wheel side and the rear wheel steering angle sensors 36 and 37 provided on the arms 33 of the 1.2 trapezoidal link units A and B are connected to this controller 35. At the same time, the vehicle speed sensor 38, the brake switch 39,
A reverse gear switch 40 and a throttle opening sensor 41 are also connected.

Then, the output signals detected by these sensors and the switch on/off signals are input to the controller 35. On the other hand, the controller 35 processes these input signals and individually determines rear wheel steering angle target values for the rear wheels 23 and 24.

This determination is carried out by patterns A to K in the rudder angle determination pattern table in Figure 3.
The process is performed as follows according to each pattern shown in .

That is, (a) When the vehicle speed is low as shown in patterns A and B in Figure 3, the steering direction of both the left and right rear wheels is reversed to the steering direction of the front wheels, and the steering angle is The wheels are made larger and the steering angles of both rear wheels are made equal.

(b) When the vehicle speed is high as shown in patterns C and D in Figure 3, the steering direction of the left and right rear wheels is set in the same phase as the steering direction of the front wheels, contrary to the above patterns A and B. At the same time, the steering angle is made smaller. Furthermore, the steering angles of both the left and right rear wheels are made equal.

Note that the patterns A to D are similar to the conventional patterns.

(c) Patterns E to H in FIG. 3 are patterns in which the brake switch and reverse gear switch are all turned off. Therefore, the steering mode is similar to the patterns of F notes A to D. However, in this pattern, the left and right rear wheel steering angles are different from each other as shown in FIG.

In other words, in the case of patterns E and F where the vehicle speed is low or low,
When the vehicle turns due to steering, the steering angle of the inner wheels whose turning radius becomes smaller is increased, and the steering angle of the outer wheels is decreased.

In addition, in the case of patterns G and H, where the vehicle speed is high, when the vehicle turns, the steering angle of the outer wheels, where the load increases due to the centrifugal force of the vehicle, is made smaller, and the inner wheels, where the load decreases. I am trying to increase the rudder angle.

(d) Furthermore, as shown in pattern I% J in Figure 3, when decelerating with the steering wheel in neutral, both left and right rear wheels are moved to the toe-in side while making the steering angles of the left and right rear wheels equal. I'm trying to change direction. This also maintains the straightness of the vehicle.

Furthermore, as shown in the pattern in the figure, when the vehicle is moving backward, the left and right rear wheels are steered to the toe-out side, while the left and right rear wheels are made to have the same steering angle regardless of the operation of the steering wheel. In other words, the vehicle is steered toward toe-in in the direction of travel when traveling in reverse, thereby maintaining the straightness of the vehicle.

As described above, according to the rear wheel turning angle determination pattern shown in FIG. 3, in addition to the conventional pattern of four items, a pattern of six new items is added. Then, the left and right wheels can be steered to the toe-in side or toe-out side by individually changing the steering angles of the left and right rear wheels or by individually changing the steering direction.

The rear wheel steering device configured as described above is different from the conventional one in that when the steering wheel 1 is turned, the front wheels 7.8 are steered, and the output signal of the front wheel steering angle sensor 22 that detects the front wheel steering angle is inputted to the controller 35. The same is true.

The controller 35 also controls the front wheel steering angle sensor 22.
In addition, vehicle speed sensor 38, throttle opening sensor 41
It receives the output signal of the brake switch 39 and the opening ON/OFF signal of the reverse gear switch 40. Then, the controller 35 determines the rear wheel turning angle target value of each of the left and right rear wheels 23.24 according to these input signals, and outputs the output signal of this rear wheel turning angle target value to the first and second motors 25.24. 2
6 individually.

Further, the first and second motors 25.26 that have received the output signal from the controller 35 as described above rotate according to the output signal from the controller 35, and the rear wheels 23.24 rotate according to the direction and amount of rotation. Turn the wheels individually.

Also, at the same time as the rear wheels 23.24 are steered, the output signal of the rear wheel steering angle sensor 36.37 that detects the actual steered angle is fed back to the controller 35, and the rear wheels 23.24 are
The steering angle of the vehicle is controlled by feedback.

Note that the worm 27 and the rack 28a are
In order to transmit only the output from the motor 25 and 26 side,
The lead angle of the gear teeth is set small. Even if an external force is applied from the rear wheels 23, 24 side, the worm gear prevents reverse rotation and prevents the rear wheels 23, 24 from wobbling.

The second embodiment shown in FIG. 4 is the above-mentioned 1.2 steering device Sr, Sj! The connection type between the 1.2 motors 25 and 26 and the 1.2 trapezoidal link units A and B is changed.

That is, a worm wheel 43 provided with a gear shaft 42 is rotatably mounted on one side of the support member 30. Also,
The eccentric shaft 43a is integrally connected to the gear shaft 42.
One side of the arm 33 is rotatably connected to a, and
The worm wheel 43 is engaged with the worm 27.

The gear shaft 42 and the eccentric shaft 43a constitute the swing link member of the present invention.

When the first and second motors 25 and 26 rotate, the worm wheel 43 rotates around the gear shaft 42 through the engagement between the worm 27 and the worm wheel 43. When the worm wheel 43 rotates in this manner, the eccentric shaft 43a rotates about the gear shaft 42 in either a clockwise or counterclockwise direction in the drawing. And eccentric shaft 4
The arm 33 connected to the rear wheel 3a is moved in either the left or right direction as indicated by the arrow y in the figure, thereby individually steering the rear wheels 23 and 24.

Note that the first and second motors 25 and 26 and the eccentric shaft 43a are
As mentioned above, the worm 27 and the worm wheel 43 are connected through meshing, but the advance angle of the teeth of these gears is set small, and only the output from the 1st and 2nd motors 25 and 26 is transmitted to the rear wheels. I am trying to communicate this to the public.

In this way, even if an external force is applied from the rear wheels 23, 24 side, the worm gear prevents reverse rotation and prevents the rear wheels 23, 24 from wobbling.

The third embodiment shown in FIG. 5 shows another embodiment in which the motors serving as the power sources for the 1.2 steering devices Sr and SfL are replaced with power cylinders.

In the third embodiment shown in FIG. 5, a hydraulic valve V which is switched in accordance with an output signal from a controller 35 is connected between a power cylinder S and a pump P. Moreover, the power cylinder S has a piston 45 provided with a rod 45a in its cylinder body 44, and is slidably installed therein. Oil chambers R, R2 are defined on the left and right sides of the piston 45, and the tip of the rod F45a is connected to the swing link member 32.

Since the configuration other than the above is the same as that of the first embodiment, the above description will be quoted as is and the description will be omitted.

When the hydraulic valve V is switched in accordance with the output signal of the controller 35, and the pump P and one of the oil chambers R1, R of the power cylinder S, for example, the oil chamber R1, communicate with each other, the other oil chamber R2 and tank T are connected. In this way, when the internal oil chambers R1 and R2 communicate with the pump P1 tank T, pressure oil is guided to the oil chamber R1, and the hydraulic oil in the oil chamber R2 on the opposite side is returned to the tank T. therefore,
The piston 45 of the power cylinder S moves rightward in the drawing according to the amount of pressure oil supplied. Furthermore, when the pump P and the other oil chamber R2 communicate with each other, it is natural that the piston 45 moves to the left in the drawing, contrary to the above.

When the piston 45 of the power cylinder S moves in the left-right direction in the drawing as described above. This stroke amount is 7pJ1.2 trapezoidal link units A and H through the swing link member 32.
This is similar to the first embodiment, in that the rear wheels 23 and 24 are individually steered.

A pair of springs 46 are provided on both sides of the piston 45, and when the power cylinder S is under no load, the piston 45 is held at the normal position shown in the figure by the spring force of the springs 46.

The spring 46 also has a fail-safe function of holding the piston 45 at the normal position and keeping the rear wheels neutral when pressure oil is no longer supplied to the power cylinder S.

In the fourth embodiment shown in FIG. 6, the motors serving as the power sources for the first and second steering devices Sr and SJ2 are replaced with rotary actuators.

The rotary type actuator C shown in FIG.
9 inside. Further, a partition member 50 is provided inside the body 47, and this partition member 50 and the rotor member 4
9, oil chambers R1%R2 are defined on both sides of the partition member 50.

A hydraulic valve V is connected to the oil chambers R1 and R2, and an eccentric shaft 48a is integrally connected to one side of the rotating shaft 48, and one side of the arm 33 is rotatably connected to the eccentric shaft 48a. ing.

Further, the rotating ring 48 and the eccentric shaft 48a constitute a swing link member of the present invention.

The configuration other than the above is the same as that of the third embodiment.

When the hydraulic valve V is switched in accordance with the output signal of the controller 35, pressure oil is guided to one of the oil chambers R, R2 of the pump P and the actuator C, for example, the oil chamber R1, and the pressure oil is guided to the oil chamber R1 of the pump P and the actuator C. The hydraulic oil in R2 is returned to the hS tank T, which is the same as in the third embodiment.

In this way, when pressure oil is introduced into the oil chamber R1, the rotor member 49 of the actuator C rotates clockwise in the drawing, and the rotating shaft 48 similarly rotates. Further, when the pressure oil is introduced into the oil chamber R2, the rotating shaft 48 naturally rotates counterclockwise in the drawing, contrary to the above.

As described above, when the rotating shaft 48 rotates clockwise or counterclockwise in the drawing, the eccentric shaft 48a is centered around the rotating shaft 48.
rotates either clockwise or counterclockwise in the drawing. The moving rear wheel 23. is connected to the eccentric shaft 48a.
24 are steered individually.

Note that a pair of left and right springs 51 are provided between one side of the rotor member 49 and the inside of the body 47.

When the actuator C is under no load, the rotor member 49 is held at the normal position shown in the figure by the action of the spring force of the spring 51. Further, when pressure oil is no longer supplied to the actuator C, it has a fail-safe function to maintain the rear wheels in neutral, which is similar to the third embodiment.

According to the first to fourth embodiments described above, both the left and right rear wheels can be controlled individually.

Therefore, the steering angles of the left and right rear wheels can be made different, and both the left and right rear wheels can be steered toward the toe-in side or toward the toe-out side.

Furthermore, by inputting information on the brake state, reverse state, and throttle opening of the vehicle into the controller, the rear wheel turning angle can be individually controlled according to the acceleration/deceleration and traveling direction of the vehicle.

Therefore, the vehicle can be steered under optimal conditions depending on the driving conditions of the vehicle.

[Brief explanation of drawings]

Drawings 1 to 3 show a first embodiment of this invention.
Fig. 1 is a circuit diagram, Fig. 2 is a plan view of the trapezoidal link unit, Fig. 3 is a rear wheel steering angle determination pattern table calculated by the controller, Fig. 4 is a circuit diagram of the second embodiment, and Fig. 5 is a plan view of the trapezoidal link unit. FIG. 6 is a circuit diagram of the third embodiment, FIG. 6 is a circuit diagram of the fourth embodiment, and FIG. 7 is a circuit diagram of a conventional rear wheel steering device. Sr--first steering device, si--second steering device, A--first trapezoidal link unit, B--second trapezoidal link unit, 25--first motor, 26--second
Motor, 31--Arm, 32--Swinging link member, 33--Arm, 34-Connecting member, 35--Controller, 42--Gear shaft, 43a--Eccentric shaft, S--
Power cylinder, 48 - rotating shaft, 48a = eccentric shaft, C
...actuator.

Claims (1)

[Claims] A rear wheel steering device that includes a steering device that steers the rear wheels using power from a power source such as a motor, and a controller that inputs driving conditions of the vehicle and controls the output of the power source. A link unit is provided, a swinging link member is connected to one side of one arm of the first and second trapezoidal link units, one side of the other arm is fixed, and a connecting member is attached to the other sides of both arms. The first and second steering devices are configured by attaching the rear wheels to the connecting member, and the first power source is linked to the swinging link member of the first steering device, and the swinging link member of the second steering device is connected to the first power source. The second power sources are linked together, and the swing link member is swung according to the outputs of the first and second power sources, and the outputs of the first and second power sources are individually controlled according to the running conditions of the vehicle. A rear wheel steering device comprising a controller connected to the first and second power sources.