JPH0734779Y2 - 4-wheel steering vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a pitman arm for front wheels for a rear wheel through a link mechanism and a mode switching gear box equipped with a mode switching actuator for switching modes when the vehicle speed is zero. The present invention relates to improvement of a four-wheel steering vehicle connected to an actuator.

[Prior Art] Various four-wheel steering vehicles are known (for example, JP-A-62-19957).
No. 2, etc.).

In these four-wheel steering vehicles, when the front and rear wheels are not neutral at the time of mode switching, the driver needs to operate the steering wheel to make the front and rear wheels neutral. However, the driver has to look at the state of the front and rear wheels each time to see how much the front and rear wheels are deviated from neutral and how much the steering wheel should be operated.

Further, Japanese Patent Application Laid-Open No. 59-81266 is known as a technique relating to four-wheel steering. However, according to this known technique, the ratio at which the rear wheels are steered with respect to the rotation of the steering wheel, that is, the steering ratio is manually variable, and the driver knows whether the front and rear wheels are at the center position. I can't.

Further, Japanese Laid-Open Patent Publication No. 60-85073 discloses a technique for issuing an alarm when the steering angle ratio is manually set, since it is dangerous if the vehicle speed exceeds a predetermined speed. However, even with this known technique, the driver cannot know whether the front and rear wheels are in the neutral position.

[Problems to be Solved by the Invention] Therefore, an object of the present invention is to enable a driver to easily know whether or not the front and rear wheels are in a neutral position, and thus to easily perform a mode switching operation. To provide a steering wheel.

[Means for Solving the Problems] According to the present invention, the front wheel pitman arm is connected to the rear wheel actuator via the link mechanism and the mode switching gear box, and the mode switching gear box is operated when the vehicle speed is zero. A four-wheel steering vehicle having a mode switching actuator for switching between the vehicle speed detection means, the rear wheel steering angle display means, and the mode position detection means for detecting the confirmation of the mode from the operation of the mode switching actuator, and the vehicle speed detection means. And a steering wheel operation request buzzer operated by a signal from the controller, the controller operating the mode switching actuator in response to a signal from the rear wheel steering angle display means.
The steering wheel operation request buzzer is activated when the rear wheels are not in the neutral position during wheel steering, and the steering wheel operation request buzzer is activated when the front and rear wheels are not in the neutral position and the mode position detecting means is not ON during the four-wheel in-phase steering. It has a function of operating the steering wheel operation request buzzer when the front and rear wheels are not in the neutral position and the mode position detecting means is not turned on during the four-wheel reverse phase steering.

[Operation] In the four-wheel steering vehicle configured as described above, at the time of mode switching, the controller operates the steering wheel operation request buzzer when the front and rear wheels are not in the neutral position based on the signal from the mode position detecting means, and the mode display lamp Blinks to alert the driver.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, one end of a front pitman arm 3 of a gear box 2 fixed to a frame connected to a steering wheel 1 is provided with a front drag ring 4
A front tie rod arm 6 formed integrally with the front steering arm 5 is connected to a front tie rod arm 6 on the other side via a front tie rod 7.

The other end of the front pickman arm 3 has one end of a torque tube 11 rotatably supported by an idler lever bracket 10 fixed to the frame F via a first idler link 8 and a first idler lever 9. Are linked to. The other end of the torque tube 11 is connected to the input side of a mode switching gearbox 30 fixed to the frame, and the rear pitman arm on the output side of the mode switching gearbox 30.
One end 13 is connected to a rear steering arc actuator 15 pivotally attached to an actuator bracket 16 fixed to the frame at one end via a rear pitman link 14. The other end of the rear steering actuator 15 is connected to the middle of a second idler lever 18 pivotally attached to a second idler lever bracket 17 fixed to the frame, and the end portion of the second idler lever 18 is a rear drag. It is connected to the rear steering arm 20 via a link 19. A rear tie rod arm 21 formed integrally with the rear steering arm 20 is connected to a rear tie rod arm 21 on the other side via a rear tie rod 22.

The front oil pump 23 supplies the oil in the oil tank 25 to the gear box 2 via the front inlet tube 24a, and returns it to the tank 25 via the filter 26 by the front return tube 24b. The oil pump 27 supplies the oil in the oil tank 25 to the rear steering actuator 15 via the rear inlet tube 28a, and the rear return tube
By 28b, it is returned to the oil tank 25 via the filter 29.

In the mode switching gear box 30, an input side bevel gear and an output side bevel gear having a diameter larger than that of the bevel gear are provided on the same axis, and a planetary gear that meshes with these bevel gears is connected to the input side bevel gear via a gear arm. It is rotatably supported on the shaft part of. Further, there is provided a mode switching actuator 33 including a mode switching in-phase actuator that operates a clutch that connects and disconnects both bevel gears, and a mode switching anti-phase actuator that locks rotation of the gear arm.

With this configuration, in the in-phase mode of four-wheel steering (4WS), the mode switching in-phase actuator is extended and the clutch is moved to connect both bevel gears. Therefore, the rotation of the torque tube 11 is directly transmitted from the rear pitman arm 13 to the rear wheels, and the in-phase steering angle characteristic in which the front wheel steering angle and the rear wheel steering angle are equal is obtained.

In the reverse phase mode, the clutch is disengaged to extend the mode switching reverse phase actuator to fix the gear arm and lock the rotation. Therefore, the rotation of the torque tube 11 is transmitted from the input-side bevel gear to the output-side bevel gear having a diameter larger than that of the input-side bevel gear through the planetary gear while being decelerated.
A reverse phase mode characteristic is obtained in which the rear wheel steering angle is smaller than the front wheel steering angle.

In two-wheel steering (2WS), both actuators are turned off, and one of the rear steering systems is fixed by a neutral locking device according to a known technique to lock the rear wheels to neutral.

Since the mode switching in-phase actuator is adapted to operate when the front and rear wheels are in the neutral position to connect the clutch to determine the in-phase mode, the in-phase position sensor 37 for detecting the in-phase mode determination is provided. ing. Similarly, the mode switching reverse-phase actuator operates when the front and rear wheels are in the neutral position to fix the gear arm to determine the reverse-phase mode. A position sensor 39 is provided. Both of these position sensors 38 and 39 together with the mode switching actuator 33 are connected to the controller 34.
It is connected to the.

The controller 34 includes a vehicle speed sensor 32 which is a vehicle speed detecting means and a rear steering angle sensor 37 which is a rear wheel steering angle detecting means.
From the steering wheel operation request buzzer 35 which is an alarm means, the rear steering angle monitor 37 which is a rear wheel steering angle display means, and the 4WS in-phase mode switch, 4WS anti-phase mode switch and 2WS switch which also function as mode display lamps not shown. The mode changeover switch 36 and the neutral lock device (not shown) are connected to each other. In addition, the mode display lamp displays the mode that was previously switched by turning on the key switch.Before the mode is confirmed at the time of mode switching, the mode switching lamp also blinks the mode switching lamp and requests the steering wheel operation. Illuminates the lamp in that mode.

In FIG. 2, the key switch of the controller 34 is ON.
Then, the controller 34 converts the signal from the rear steering angle sensor 37 into an analog-digital signal (step S41) and displays it on the rear steering angle monitor 37 (step S40).
42).

At the time of control, as shown in FIG. 3, the controller 34 determines whether the vehicle speed is zero based on the signal from the vehicle speed sensor 32 (step S1). If YES, the 2WS mode switch is turned on based on the signal from the mode switch 36.
It is determined whether or not N is set (step S2). If YES, the neutral lock release device is turned off, and it is determined whether or not the rear wheels are neutrally locked (step S3). In the case of NO, the steering wheel operation request buzzer 35 is activated and the 2WS mode lamp blinks to alert the driver (step S4 and
S5). With this alarm, the driver looks at the rear steering angle monitor 37 to determine the direction and amount of the steering wheel operation, and when the steering wheel operation is performed to return the rear wheels to the neutral position, the rear wheels are locked at the neutral position, and step S3 is executed. If YES, controller 34
Turns off the mode switching actuator 33 (step S
6). Next, similarly, it is determined whether or not the opposite-phase position sensors 38 and 39 are both OFF (step S7). N
In the case of O, the process returns to step S6, the OFF signal is output again to the mode switching actuator 33, and the mode switching actuator 33 is turned OFF and step S7
If YES, turn off the steering wheel operation request buzzer 35 (step S8), turn off the lamp of the mode that was switched last time (step S9), turn on the 2WS mode lamp (step 10), and end the control. .

If step S2 is NO, the 4WS common mode switch is ON.
If YES, the mode switching anti-phase actuator is turned off (step S13), and the mode switching in-phase actuator is turned on (step S14). Next, it is determined whether or not the in-phase position sensor 38 is ON, that is, whether or not the mode switching in-phase actuator operates normally and the in-phase mode is confirmed (step S15). In the case of NO, that is, when the front and rear wheels are not in the neutral position, the steering wheel operation request buzzer 35 is activated, and the 4WS common mode lamp blinks to give an alarm (steps S16 and S17). With this alarm, the driver sees the rear steering angle monitor 37 and knows the direction and amount of the steering wheel operation, operates the steering wheel, and the front and rear wheels are returned to the neutral position, and the mode switching in-phase actuator operates and step S15 becomes YES, Turn on the unlock actuator (step S1
8). Next, it is determined whether or not the neutral lock is released (step S19). If YES, the steering wheel operation request buzzer 35 is turned off (step S20), the previous mode lamp is turned off (step S21), and the 4WS in-phase is set. The mode lamp is turned on (step S22), and the control ends. Also, step S12
If NO, the process directly goes to step S21.

When step S11 is NO, it is determined whether the 4WS reverse phase mode switch is ON (step S23). If YES, the mode switching in-phase actuator is turned off (step S24), and the mode switching anti-phase actuator is turned on (step S25). Next, it is determined whether the anti-phase position sensor 39 is ON, that is, whether the mode switching anti-phase actuator has normally operated and the anti-phase mode has been established (step S2).
6). In the case of NO, that is, when the front and rear wheels are not in the neutral position, the steering wheel operation request buzzer 35 is activated, and the 4WS reverse phase mode lamp blinks to give an alarm (steps S27 and S2).
8). With this alarm, the driver sees the rear steering angle monitor 37 to know the direction and amount of the steering wheel operation, operates the steering wheel to return the front and rear wheels to the neutral position, and the mode switching negative-phase actuator operates to set YES in step S26. Then, the controller 34 turns on the unlock actuator (step
S29). Next, it is determined whether or not the neutral lock is released (step S30). If YES, the steering wheel operation request buzzer 35 is turned off (step S31), the previous mode lamp is turned off (step S32), and the 4WS reverse operation is performed. The phase mode lamp is turned on (step S33), and the control ends. Also, step S23
If is NO, the process directly goes to step 32.

[Effects of the Invention] As described above, the present invention has the following excellent effects.

(I) Since the handle operation request buzzer operates when the front and rear shafts are not in the neutral position when the mode is switched, the driver may steer to the neutral position.

(Ii) Therefore, the driver does not have to get off the vehicle every time the mode is switched.

(Iii) Mode switching between two-wheel steering and four-wheel steering (in-phase and anti-phase) can be easily performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall configuration diagram showing an embodiment of the present invention, FIG. 2 is a flow chart diagram for displaying a steering angle, and FIG. 3 is a control flow chart diagram for mode switching. 3 ... Front pitman arm, 15 ... Rear steering actuator, 30 ... Mode switching gear box,
31 …… Rear steering angle sensor, 32 …… Vehicle speed sensor, 33 …… Mode selector actuator, 34 …… Controller, 35 …… Handle operation request buzzer, 36 …… Mode selector switch, 37
...... Rear steering angle monitor, 38 …… In-phase position sensor, 39
... Reverse-phase position sensor

Claims (1)

[Scope of utility model registration request] 1. A four-wheel steering vehicle having a front wheel pitman arm connected to a rear wheel actuator via a link mechanism and a mode switching gear box, the mode switching gear box having a mode switching actuator for switching modes when the vehicle speed is zero. In the above, a vehicle speed detection means, a rear wheel steering angle display means, and a mode position detection means for detecting the confirmation of the mode from the operation of the mode switching actuator are provided, and further signals from the vehicle speed detection means and the rear wheel steering angle display means are provided. And a steering wheel operation request buzzer that operates in response to a signal from the controller. The controller operates the steering wheel operation request buzzer when the rear wheels are not in the neutral position during two-wheel steering. When four-wheel in-phase steering, the front and rear wheels are not in the neutral position The steering wheel operation request buzzer is activated when the detection means is not ON, and the steering wheel operation request buzzer is activated when the front and rear wheels are not in the neutral position and the mode position detection means is not ON during four-wheel reverse phase steering. A four-wheel steering vehicle having a function.