JPS6127769A - Rear-wheel steering controller for vehicles - Google Patents

Abstract

PURPOSE:To improve drivability for garaging, file parking, etc., controlling a selector valve with operation of a mode switch, while selecting a rear-wheel non- steering mode, a rear-wheel opposite phase steering mode and a rear-wheel equal phase steering mode in an optional manner. CONSTITUTION:In time of rear-wheel non-steering, if a mode switch 30 is selected to a neutral mode 30b, both solenoids 29a and 29b are not energized, and a selector valve 29 keeps up a neutral position 29c. Therefore, in time of front- wheel steering, power steering oil pressure is not fed to an actuator 16 whereby rear wheels 2 are no longer steered. As for rear-wheel non-steering, if the switch 30 is selected to an opposite phase steering mode 30c, the selector valve 29 comes to an opposite phase position 29d whereby oil pressure in time of front- wheel steering is fed to a chamber 19 of the actuator 16. As a result, rear wheels 2 are steered in the reverse direction. As for rear-wheel equal phase steering, the switch 30 is selected to a equal phase steering mode 30d. The actuator 16 makes rear wheels 2 steer in the same direction as front wheels 1.

Description

Detailed Description of the Invention (Industrial Application Wf) The present invention is a rear wheel steering control device that simultaneously steers the rear wheels when steering the front wheels of a vehicle to facilitate garage parking and parallel parking. It is related to.

(Prior Art) This type of rear wheel steering control device is configured so that when the front wheel steering system is of a power steering type, the rear wheels are also steered via an actuator using power steering hydraulic pressure that power assists the steering of the front wheels. This is advantageous in the sense that there is no need to newly install a hydraulic system.

Therefore, the present applicant had previously proposed this type of rear wheel steering control device in Japanese Patent Application No. 15885/1983.

This device is configured to supply power steering hydraulic pressure to the actuator so that the actuator steers the rear wheels in the opposite direction to the front wheels (referred to as reverse phase steering of the rear wheels).

(Problem to be Solved by the Invention) However, in the case of a rear wheel steering control device that only performs time-phase steering to rotate the rear wheels, it is difficult to park the rear wheels in a garage or parallel park due to the following reasons. Not necessarily useful. For example, when starting from a parked state with one side of the vehicle approaching an obstacle, if the rear wheels are steered in reverse phase, the rear of the vehicle will collide with the obstacle, making it impossible to start from the parked state. In this case, the rear wheels should not be steered, and it is preferable to first steer the rear wheels in the same direction as the front wheels when starting the vehicle (referred to as in-phase steering of the rear wheels) so that the entire vehicle body is free from obstacles. It is best to move away from the vehicle and then reverse-phase steer the rear wheels to reduce the turning radius.

If even after doing this, the vehicle cannot depart because there are other vehicles in front and behind it, it is necessary to take measures such as turning the vehicle without turning the rear wheels and repeating the above-mentioned rear wheel steering again.

Therefore, in order to facilitate garage parking and parallel parking, simply having the rear wheels steered in reverse phase may not be sufficient, or as described above, it may be harmful and the driver may be required to steer the rear wheels in a reverse direction depending on the situation. It must be possible to arbitrarily select and use the rudder (neutral) mode, rear wheel anti-phase steering mode, and rear wheel in-phase steering mode.

Means for Solving Problem C) In order to meet such demands, the present invention proposes a rear wheel steering control device for a vehicle that is configured so that the driver can arbitrarily select one of the above eight modes. Specifically, in the power steering hydraulic pressure supply circuit of the actuator, there is a neutral position in which power steering hydraulic pressure is not supplied to the actuator, and a reverse position in which power steering hydraulic pressure is supplied to the actuator so that the actuator steers the rear wheels in the opposite direction to the front wheels. An 8-position switching valve is installed that has a phase position and an in-phase position that supplies power steering hydraulic pressure to the actuator so that the actuator steers the rear wheels in the same direction as the front wheels, and the switching valve can be manually moved to any position. 0 (Function) When the mode switch sets the 8-position switching valve to the neutral position, power steering hydraulic pressure is not supplied to the actuator when steering the front wheels, and the rear wheels cannot be steered. You can prevent it from happening. When the 8-position switching valve is set to the reverse phase position by the mode switch, when the power steering hydraulic pressure for steering the front wheels is supplied to the actuator, this actuator can steer the rear wheels in the reverse phase. With the mode switch setting the 8-position switching valve to the same phase position, when the power steering hydraulic pressure for steering the front wheels is supplied to the actuator, this actuator can steer the rear wheels in the same phase. Therefore, by operating the mode switch and selecting one of the eight positions of the switching valve, the driver can arbitrarily obtain a rear wheel non-steering mode, a rear wheel reverse phase steering mode, or a rear wheel in-phase steering mode. Become.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

Fig. 1 shows an embodiment of the rear wheel steering control device of the present invention, in which 1 indicates two front wheels, 2 indicates two rear wheels, 8 indicates a steering wheel, 4 indicates a steering gear, and 5 indicates power steering. Reference numeral 5 includes a control pulp 6 provided in relation to the steering gear 4 and a power cylinder 7.

The front two wheels 1 are linked to each other through a conventional steering linkage consisting of a tie rod 8, a side rod 9, and a knuckle arm 10, and the tie rod 8 is drivingly connected to the steering link wheel 8 through a steering gal. Thus, when operating the steering wheel 8,
The rotation is transmitted to the tie rod 8 via the steering gear 4, displacing it longitudinally (to the right in the figure when steering to the left, to the left in the figure when steering to the right), and moves both front wheels 1 in the steering direction. Can be steered.

A hydraulic oil flow from a pump (not shown) flows through the control pulp 6 of the power steering 5, and after this flow, the hydraulic oil flow is returned to the pump. The control valve 6 throttles the hydraulic oil flow in response to the steering load when steering the front wheels by the steering wheel 8, generates power steering hydraulic pressure, and sends it to the connecting pipe 11 when steering to the left, or to the connecting pipe 11 when steering to the right. The time is output to the connection pi 'f12.

The power steering hydraulic pressure output to the engine 11 or 12 is supplied to the corresponding cylinder chamber of the power cylinder 7, and power assists the longitudinal displacement of the tie rod 8, that is, the steering of the front wheels 1, and if light power steering is possible. The rear wheels 2 are also connected to each other via a normal steering linkage consisting of a tie rod 18, a side rod 15, and a knuckle anim 15, and an actuator 16 for steering the rear wheels is provided in relation to the tie rod 18. This actuator includes a cylindrical housing 17 fixed to the vehicle body, and a tie rod 18 is slidably passed through the housing in the longitudinal direction. A piston 18 is integrally formed on the tie rod 18, and is slidably fitted into the cylindrical housing 17, so that the piston 18 is attached to the tie rod 18.
A pressure chamber 19.20 is defined on both sides of the pressure chamber 8.

A small diameter portion 18a is set on the tie rod 18, and a spring seat 21.22 is slidably fitted into the small diameter portion 18a, and a reaction spring 28 is compressed between these spring seats.
2 is elastically supported at the separation limit position shown in the figure with a preload. Then, by housing the spring seats 2122 in the air chambers 24 and bringing the spring seats 21.22 into contact with the end walls 24a and 24b of the air chambers, the tie rod 13 is placed in the neutral position shown in the figure with the preload (the rear wheel is elastically supported at the stroke position of the tie rod 18 where it is not steered.

Power steering hydraulic pressure supply circuits 25 and 26 are provided extending from the power cylinder 7 chambers to which the pipes 11 and 12 are connected, and power steering hydraulic pressure supply circuits 27 and 28 are also extended from the pressure chambers 19 and 20 of the actuator 16, respectively. These circuits 25, 26 and 2
7. Insert the 8-position switching valve 29 between 28 and 28. This valve is a spring center type 8-position electromagnetic switching valve, and when both solenoids 29a and 29b are deenergized, it is in the neutral position 290, when the solenoid 29a is energized, it is in the opposite phase position z9d, and when the solenoid 29b is energized, it is in the in-phase position. 29e. Note that the switching valve 29 is in the neutral position 290 and the circuit 25~
28 are individually shut off, power steering hydraulic pressure is not supplied to the pressure chambers 19, 20, and these pressure chambers are used as containment chambers, and the circuits 25, 26 are connected to the circuits 27, 28, respectively, at the reverse phase position 29 (i). , circuit 25. at in-phase position 298.
26 are connected to a circuit 28127, respectively.

The switching valve solenoids 29a and 29b are controlled by being connected to the 8-position mode switch 80, the front wheel large steering angle detection switch 31, and the battery 32 as shown in the figure. First, to explain the mode switch 30, this switch has a manual contact 80a and eight fixed contacts sob, aoc, and aod, and when the manual contact 80a is brought into contact with the fixed contact 8.Ob, the rear wheel is not rotated. Fixed contact 80C for rudder mode (neutral mode)
When contacting the rear wheel reverse phase steering mode, the fixed contact 8
00 is connected to one terminal of the solenoid 29a, and the fixed contact 80d is connected to one terminal of the solenoid 29b. The manual contact 80a is the front wheel large steering angle detection switch 8.
1, and the other terminal of the switch is connected via the battery 82 to the other terminals of both solenoids 29a and 29b.

The front wheel large steering angle detection switch 81 is connected to an extension tube 88 on the power cylinder 7, as shown in FIG. 2(a).
A switch case 81a made of a non-conductive material is fixedly fixed to the extension tube through a switch case 81a, a movable contact 81b made of a conductive material is housed inside the switch case 81a so as to be movable in the radial direction of the tie rod 8, and this is pushed onto the tie rod 8. A spring 310 attached and a pair of terminals 81 fixed inside the switch case.
d.

811e. Then, a notch 8a into which the movable contact 84b enters is formed in the tie rod 8 in a shift range of the tie rod 8 corresponding to a front wheel steering angle range below a certain level,
At this stroke position, ``from the movable contact 81b to the terminal a
These terminals are arranged so that ci and aie are separated.

Thus, while the front wheel steering angle is below a certain level, the movable contact 81b enters the notch 8a as shown in FIG. 2(a), and the terminal a
There is no conduction between xd and axe, and the switch 81 is turned off. Then, while the front wheel steering angle is above a certain level, the movable contact 81b comes off the notch 8a as shown in No. 211(b) (this figure shows the state when steering to the right) and connects both terminals 81 d , , 818
As a result of conduction between these terminals, the switch 81 can detect that the front wheel steering angle is above a certain level by turning on the switch 81.

The operation of the above embodiment will be explained next. When the driver does not want to steer the rear wheels 2, or when it is dangerous to steer the rear wheels when driving at high speed, the driver should set the manual contact aOa of the mode switch 80 to the first position.
As shown in the figure, contact the solid contact 30b to select the neutral mode. At this time, the solenoids 29a, 29b+-j continue to be deenergized under any conditions, and the switching valve 29 is maintained at the neutral position 290 as shown in FIG. Therefore, even if the power steering hydraulic pressure is guided to the circuit 25 or 26 by front wheel steering, it will not be supplied to the actuator 16, and the actuator 16 will not steer the rear wheels 2 and will keep them in a non-steered state. I can do it. Note that even if the rear wheels 2 receive kickback from the road surface at this time, there is no risk of the vehicle being steered because the tie rods 18 are locked by the containment oil in the pressure chambers 19 and 20.

Next, when desiring reverse phase steering of the rear wheels 2, the driver selects the reverse phase steering mode by bringing the movable contact 80a of the mode switch 80 into contact with the fixed contact aOC as shown in FIG. In this state, when the front wheel 1 is steered to the right beyond a certain level as shown in FIG. 8, the front wheel large steering angle detection switch a1 is closed as described above, and the solenoid 29a is energized by the battery 82. At this time, the switching valve 29 is in the reverse phase position 29d as shown in FIG. 8, allowing the circuits 25 and 26 to communicate with the circuits 27 and 28, respectively.

On the other hand, when the front wheels are steered, the power steering hydraulic pressure is outputted to the pipe 11 as described above, and the power steering hydraulic pressure is supplied to the pressure chamber 19 from the related circuit 25 through the circuit 27. Since the front wheel steering angle is above a certain level, this power steering oil pressure is sufficiently high, and the piston 18 and therefore the tie rod 13 are moved to the right by overcoming the pre-lead by the reaction force spring 28 as shown in FIG. The front wheels 1 can be steered in the opposite direction.

Furthermore, if the front wheel 1 is reversely steered to the right for more than a certain amount,
The switching valve 29 is similarly set to the opposite phase position 29a. In this case, as described above, the power steering hydraulic pressure is output to the pipe 12, so this hydraulic pressure is transferred to the circuit 26.
28 to the pressure chamber 20, and the actuator 16 can again steer the rear wheels 2 in the opposite direction to the front wheels 1 as required.

Next, when desiring in-phase steering of the rear wheels 2, the driver selects the in-phase steering mode by bringing the movable contact 8oa of the mode switch 3o into contact with the fixed contact 80d as shown in FIG. In this state, when the front wheel 1 is steered to the right beyond a certain level as shown in FIG. 4, the front wheel large steering angle detection switch 81 closes as described above, and the solenoid 29a is energized by the valve y-vs2. At this time, the switching valve 29 is in the same phase position 29e as shown in FIG. 4, and the circuits 25.26ft and 25.26ft are respectively connected to the circuits 28.27.

On the other hand, when the front wheels are steered, the power steering hydraulic pressure is outputted to the pipe 11 as described above, and the power steering hydraulic pressure is supplied to the pressure chamber 20 from the related circuit 25 through the circuit 28. Since the front wheel steering angle is above a certain level, this power steering oil pressure is sufficiently high, and the piston 18 and therefore the tie rod 18 are moved to the left as shown in FIG. The vehicle can be steered in the same direction as the front wheels 1.

Furthermore, if the front wheel l is reversely steered to the left for a certain amount of time,
The switching valve 29 is similarly set to the in-phase position 29e. In this case, as described above, since the power steering hydraulic pressure is output to the pipe 12, - this hydraulic pressure is output to the circuit 26.
．． 27 to the pressure chamber 19, and the actuator 16 can again steer the rear wheels 2 in the same direction as the front wheels 1 as required.

By the way, if you forget to set the motor switch 8o to the neutral mode shown in Fig. 1 and drive at high speed with the reverse phase steering mode shown in Fig. 3 or the in-phase steering mode shown in Fig. 4, the high vehicle speed In this case, the front wheel large steering angle detection switch 81 is turned off as described above because the front wheel steering angle is not made to exceed the above-described certain value. Therefore, the solenoids 29a, 29
b is not energized and the switching valve 29 is in the neutral position 29.
Keep 0. Therefore, even if the vehicle drives at high speed without returning the mode switch 80 to the neutral mode, there is no danger that the rear wheels 2 will be steered.

FIG. 5 shows another embodiment of the invention, in which the circuits 27, 28 are placed in communication with each other in the neutral position 290 of the switching valve 29. In this case, the switching valve 29 is moved to the reverse phase position 29.
(Even after switching from the 1 or in-phase position 298 to the neutral position 290, communication is maintained between the circuits 27 and 28, that is, between the actuator pressure chambers 19 and 2o (see Figs. 1, 3, and 4). It is possible to prevent the rear axle 2 from remaining steered after the switching. In this case, the pressure chamber 19°2
Since hydraulic oil can come and go through circuits 27 and 28 between 0 and 0,
Although the tie rod 18 cannot be kept pulled up, steering of the rear wheels 2 due to kickback from the road surface can be prevented by preloading the reaction spring 23.

(Effects of the Invention) Thus, as described above, the rear wheel steering control device of the present invention is configured so that the driver can arbitrarily switch between the rear wheel non-steering mode, the rear wheel reverse phase steering mode, and the rear wheel in-phase steering mode. By selecting and using these modes depending on the situation, the driver can extremely easily take the vehicle in and out of the garage, parallel park, and start from the parked state, which can be extremely effective in practical use. .

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing an embodiment of the rear wheel steering control device of the present invention, Fig. 2(a) is a sectional view of the front wheel large steering angle detection switch used in the embodiment, and ff1('b) is Similarly, FIGS. 8 and 4 are explanatory views of the operation of the apparatus shown in FIG. 1, respectively, and FIG. 5 is a circuit diagram of a changing section showing another example of the present invention. 1...Front wheel 2...Rear wheel 8 steering wheel 4...Steering gear 5...Power steering 6...Control valve? ...Power cylinder 8...Tie rod 9...
・Side rod 1o...knuckle arm 18・
・・Tie rod 14・・Side rod 15・
...Knuckle arm 16...Actuator 18
... Piston 21.22 ... Spring seat 28
... Reaction springs 25 to 28 ... Power steering hydraulic pressure supply circuit 29
... 8 position switching valve 290 ... Neutral position 29 (
1... Anti-phase position 29e... In-phase position 80.
...Mode switch 81...Front wheel large steering angle detection switch 82...Battery. Figure 1 Figure 2 (a) (b) Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. In a vehicle in which the front wheels steered by the steering wheel are power assisted by power steering hydraulic pressure, and the rear wheels are also steered via the actuator by this power steering hydraulic pressure, the actuator is installed in the power steering hydraulic pressure supply circuit of the actuator. a neutral position in which power steering hydraulic pressure is not supplied to the actuator, a reverse position in which power steering hydraulic pressure is supplied to the actuator so that the actuator steers the rear wheels in the opposite direction to the front wheels, and a reverse position in which the actuator steers the rear wheels in the same direction as the front wheels. A rear vehicle characterized in that a three-position switching valve having an in-phase position for supplying power steering hydraulic pressure to an actuator for steering is inserted, and a mode switch is provided for manually switching the switching valve to an arbitrary position. Wheel steering control device.