JPH055710B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an integrated control device for a suspension device and a steering device with variable characteristics.

A vehicle's suspension device has the role of supporting the weight of the vehicle and cushioning road surface irregularities, and it not only improves ride comfort but also prevents pitching, rolling, and
Furthermore, it has a significant effect on stability and responsiveness during turning. Therefore, by appropriately changing the suspension characteristics of the front and rear wheels of the vehicle, the dynamic characteristics can be varied in various ways. For example, in Utility Model Application Publication No. 56-147107, a steering sensor that detects changes in steering angle and a vehicle speed sensor are used to detect roll speed, and control is performed to increase (harden) the damping force of all-wheel shock absorbers. A device has been disclosed that prevents the roll speed from exceeding a predetermined value and improves both maneuverability and ride comfort.

On the other hand, power steering devices have become widely used as steering devices for steering vehicles, especially from the viewpoint of ease of steering. Due to this significant impact, various improvements have been proposed in the past. For example, Japanese Patent Application Laid-Open No. 55-55059 discloses that the number of revolutions of an oil pump that supplies hydraulic pressure to a hydraulically operated power steering system is controlled according to changes in vehicle speed, the axle load of the steered wheels, or steering resistance. A control device has been proposed that stabilizes steering by supplying pressure oil.

These conventional devices have individually improved the suspension device or steering device,
Although this method has achieved a certain degree of effectiveness, there are limits to its effectiveness when these suspension devices and steering devices are individually controlled. In particular, since there are individual differences in driver preferences regarding vehicle dynamic characteristics such as steering response and ride comfort, which differ widely from person to person, these conventional methods do not necessarily meet the driver's needs. It wasn't.

Therefore, it is an object of the present invention to comprehensively control a suspension device and a steering device with variable characteristics to provide appropriate steering response and control according to the driver's preference.
The object of the present invention is to provide a control device for a suspension device and a steering device that can provide stability, ride comfort, etc.

The object of the present invention is to provide at least one of a suspension device for each wheel, a steering device for steering a steerable wheel among the wheels, and a damping force and a spring constant of the suspension device. , a first control means that changes the suspension characteristics to either an all-wheel hard state or an all-wheel soft state by simultaneously switching all wheels; and a second control means that changes a transmission characteristic between a steering wheel of a steering device and a steered wheel. control means;
A first control signal for simultaneously switching at least one of the damping force and spring constant of the suspension device for all wheels is output to the first control means, and the transmission of the steering device is performed in accordance with the output of the first control signal. a controller that outputs a second control signal for changing the characteristic to the second control means, the controller being configured to change the transmission characteristic of the steering device simultaneously with the change of the suspension characteristic of the suspension device. This can be achieved by a comprehensive control system for suspension and steering, which is characterized by:

According to the present invention, since the controller is provided to control the suspension characteristics of the suspension device and the steering characteristics of the steering device to be changed at the same time, the dynamic characteristics of the vehicle can be adjusted according to the driver's preference. It becomes possible to change it over a wide range. For example, if the suspension device has a large spring constant or has a relatively strong damping force, increasing the assist force of the power steering device will create a sporty feeling that responds sensitively to steering operations. is obtained.
On the other hand, if the suspension characteristics are blackened so that the spring constant of the suspension device becomes smaller or the damping force is weakened, and the assist force of the power steering device is controlled to be weakened accordingly, the vehicle will be It gives you a gentle feeling. When using a manual steering system, a sporty feeling can be obtained by reducing the steering gear ratio for hard suspension characteristics and improving steering sharpness, and increasing the steering gear ratio for soft suspension characteristics. If you turn the steering relatively gently, you can get a gentle feeling. Other combinations include weakening the assist force of the power steering device for hard suspension characteristics, or increasing the steering gear ratio and increasing the assist force of the power steering device for soft suspension characteristics. Alternatively, the steering gear ratio may be reduced. In this case, the change in the vehicle dynamic characteristics due to the switching of the characteristics does not appear too drastically, so it is suitable for cases where it is desired to change the dynamic characteristics in a relatively small range.

Although the characteristic control according to the present invention may be selectively performed by a manual switch, it is also possible to perform automatic switching depending on the driving conditions of the vehicle.

For example, a gas spring device is used in the suspension device, and a control gas chamber is connected to the gas chamber of the gas spring device via a solenoid valve, and the effective volume of the gas chamber is changed by opening and closing the solenoid valve to control the gas spring. All you have to do is change the characteristics of In addition, an oleo damper in which the piston is provided with a variable diameter orifice may be used, or a means for varying the volume of the gas chamber of the gas spring and a means for varying the diameter of the piston orifice of the oleo damper may be combined. .
Furthermore, any means may be used as long as the suspension characteristics can be varied between hard and soft. As means for varying the characteristics of the steering device, in the case of a power steering system, a known method that changes the power assist force may be used, such as a method that changes the rotation speed of the hydraulic pump of the power steering system, Alternatively, any method may be used, such as a method that changes the bypass amount of pressure oil. In the case of manual steering, a gear ratio switching mechanism that changes the steering gear ratio may be provided. In any case, by employing such means, it is possible to change the transmission characteristics between the steering wheel and the steered wheels by making the operating force of the steering device lighter or heavier.

Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIGS. 1 and 2, the handle 10
is connected via a steering shaft 12 to a pinion shaft 16 having a steering pinion 14 . The pinion 14 meshes with a rack 20 on the steering rack shaft 18.
8 moves left and right according to the rotation of the pinion 14, and connects the front wheels 26, 28 via the knuckle arms 22, 24.
The steering force is transmitted to the In order to assist this steering force, a hydraulically operated power assist device 30 is provided, and this device has a control valve 31 provided on the pinion shaft 16 and a power cylinder 32 on the rack shaft 18. cylinder 32
An oil pump 36 connected to the engine 34 is provided to supply hydraulic pressure to the engine 34. Pressure oil from the pump 36 is introduced into the control valve 31 through a hydraulic pressure supply passage 38, is switched by the valve 31 according to the operation of the handle 10, and is supplied to the power cylinder 3 via a hydraulic passage 40 or 42.
The piston 32
Move a to assist the steering force. At this time, the hydraulic passage to which pressure oil is not supplied is the hydraulic return passage 4.
4 to pump the hydraulic oil in the cylinder 32
Return to. The hydraulic pressure return passage 44 is provided with a solenoid valve 46 that adjusts the amount of oil returned to the pump 36 through the passage 44, and the hydraulic supply passage 38 is provided with a bypass passage 49 that communicates with the solenoid valve 46. The solenoid 46a of the valve 46 is connected to a controller 50, which receives power from a power source 51, and operates a vehicle speed sensor 52 and a manual switch 54.
Solenoid valve 46 receives the signal from
send a control signal to. Plunger 46 of valve 46
b is displaced by an amount corresponding to the current or electric power from the controller 50, thereby changing the flow rate in the passage 38 and controlling the hydraulic pressure in the cylinder 32, that is, the assist force. front wheel 2
A suspension device 60 is provided in association with the wheels 6 and 28 and the rear wheels 56 and 58. This suspension device includes a shock absorber 66 consisting of a spring 62 and an oleo damper 64, and furthermore, an air spring 68 is formed around the damper 64 by a diaphragm made of a suitable elastic material. The orifice provided in the piston of the shock absorber 66 has a variable diameter, and a solenoid 69 is installed in the piston rod 67 to change the diameter.
A plunger is provided which is driven by the
When the solenoid 69 is energized, the plunger rotates to reduce the diameter of the orifice, increase the damping force, and harden the suspension characteristics of the suspension device. Furthermore, the air spring 68 is connected to a control air chamber 72 through an air pipe 70, and the state of communication between the air spring 68 and the control chamber 72 is controlled by the operation of a solenoid valve 74 provided at the entrance of this chamber 72. Ru. In this example, when the solenoid 74a of the solenoid valve 74 is energized, communication is cut off. When the communication between the air spring 68 and the control chamber 72 is cut off, the effective volume of the air chamber is reduced, so the spring constant of the air spring increases, and the suspension characteristics of the suspension system become harder. Thus, the suspension characteristics of the suspension system can be controlled by operating the solenoids 69, 74a in response to signals from the controller 50.

As described above, the controller 50 receives the vehicle speed signal as an input, and the control signal given from the controller 50 to the solenoid valve 46 changes depending on the vehicle speed. That is, the solenoid valve 46 is controlled so that the amount of pressure oil supplied from the pump 36 to the control valve 31 decreases as the vehicle speed increases. When the manual switch 54 is operated, the solenoid valve 4 is activated from the controller 50.
The level of the signal applied to the valve 46 decreases, the opening degree of the valve 46 decreases, and the assist force increases as a whole. At the same time, a signal is given from the controller 50 to the solenoids 69, 74a of the suspension device, and the characteristics of the front and rear wheel suspension devices become hard.

3 and 4 show an embodiment of the invention using a manual steering system.

In the device of this example, the steering device includes a gear mechanism 80 with a variable gear ratio so that the transmission characteristics between the steering wheel and the steered wheels can be changed. This gear mechanism 80 is provided in the middle of the steering shaft 12, and controls the gear ratio between the shaft part on the handle 10 side, that is, the input shaft 12a, and the shaft part on the pinion shaft side, that is, the output shaft 12b.
It can be changed by a signal from the controller 50. A gear 82 is formed integrally with the input shaft 12a, and the gear 82 meshes with a gear 84. The gear 84 includes a gear casing 90 that supports these shafts 12a and 12b via a bearing device 86 attached to the input shaft 12a and a bearing device 88 attached to the output shaft 12b.
The countershaft 92 is housed in the casing 90 and is rotatably attached to a countershaft 92 that is attached to the casing 90 substantially parallel to the input/output shaft. A gear 94 having a smaller number of teeth than the gear 84 is provided integrally with the gear 84, and the gear 94 meshes with a gear 96 rotatably attached to the output shaft 12b. Input shaft 12a and output shaft 12
A gear 98 is formed on the input shaft 12a, a gear 100 is formed on the output shaft, and a gear 102 is provided integrally with the gear 96 adjacent to the gear 100, at the mutually adjacent distal ends of the shafts b. A coupling sleeve 104 is splined to these gears 98, 100, 102. The sleeve 104 includes a shift fork 1 for moving the sleeve.
06 is engaged. Shift fork 106 is
It is attached to a plunger 112 actuated by a solenoid 110 housed in a casing 108 supported by bearing arrangements 86,88. The solenoid 110 is energized or demagnetized by a signal from the controller 50.
When 0 is not energized, the plunger 112 is pressed to the lower position in FIG. 4 by the spring 114. At this time, the sleeve 104 is engaged with both the gear 100 of the output shaft 12b and the gear 102 integrated with the gear 96, and the output shaft 12b rotates together with the gear 96.
Therefore, the handle 10 that rotates the input shaft 12b
The steering force is transmitted in this order to gear 82, gear 84, gear 94, and gear 96, thereby rotating the output shaft. In this case, the ratio of the steering angle of the output shaft to the input shaft (gear ratio) is large, and the steering force of the handle 10 is relatively small. When the solenoid 110 is energized and the plunger 112 is pulled upwardly against the force of the spring 114, the shift fork 106 moves against the sleeve 10.
4, the sleeve 104 disengages the gear 100 of the output shaft and the gear 102 integrated with the gear 96, and the sleeve 104 disengages the gear 98 of the input shaft 12a and the gear 100 of the output shaft 12b. and engage both. Thereby, the input and output shafts 12a and 12b are directly connected, and the steering force for rotating the input shaft is directly transmitted to the output shaft 12b. In this case, the above-mentioned gear ratio is small, and at the same time the responsiveness of the steering becomes high, a relatively large steering force is required. The inputs to controller 50 and suspension equipment in this example are the same as in the previous example. Therefore, the driver can operate the manual switch 54 to simultaneously change the suspension characteristics and the transmission characteristics between the steering wheel and the steering wheels, thereby obtaining the desired motion characteristics.

The above-mentioned examples illustrate specific combinations of the transmission characteristics between the steering wheel and the helm and the suspension characteristics of the suspension device, and the combinations according to the invention include all other combinations.

5 and 6 show part of the dynamic characteristics when the vehicle speed is held approximately constant for a specific combination of the transmission characteristics between the steering wheel and the steering wheel and the suspension characteristics of the suspension device according to the present invention. has been done.

FIG. 5 shows the relationship between the steering force of the steering wheel 10 and the yaw rate. Lines a and b show the characteristics when a manual steering device is used, and line a shows the characteristics when the all-wheel suspension characteristics of the suspension device are soft. The damping force is small, and line b indicates the case where the all-wheel suspension characteristics are controlled to be hard. In this case, the steering force and yaw rate are almost directly proportional, and the yaw rate is larger when the suspension characteristic is harder for the same steering force. Lines c and d are when a power steering device is used and the assist force is controlled to be low; line c shows soft all-wheel suspension characteristics, and line d shows hard all-wheel suspension characteristics. This shows what was controlled in this way. In this case as well, the steering force increases as the yaw rate increases, but this tendency is slower than in lines a and b. This is because the assist force of the power steering device is acting. In general, the control valve of a power steering device is a torque-sensitive type, and assist force begins to be generated when the steering force exceeds the point indicated by A or B, which increases the amount of pressure oil supplied to the power cylinder as the steering resistance increases. . Regarding lines c and d, if the yaw rate is the same, a softer all-wheel suspension characteristic requires a larger steering force. Lines e and f are the cases where the power steering device was similarly used and the assist force was controlled to be large; line e was controlled so that the all-wheel suspension characteristics were soft, and line f was controlled so that the suspension characteristics were hard. This is the case. The trends of lines e and f are the same as those of lines c and d, but since the assist is large, the overall steering force is small. Even in this case, the assist force is cut off below points C and D so that the driver can obtain an appropriate steering sensation. By arbitrarily combining the suspension characteristics of the suspension with the transmission characteristics between the steering wheel and the steering wheel of the power steering, it is possible to obtain a steering feeling that matches the driver's preference. In the embodiments shown in FIGS. 1 and 2, c and f are selected as the steering characteristics, and the switching is performed in accordance with the switching between hard and soft suspension characteristics.

FIG. 6 shows the relationship between the steering angle of the steering wheel and the yaw rate when a manual steering device is used. Lines a and b indicate the input shaft 12a and output shaft 12b of the steering shaft 12.
This is a case where the steering force is controlled to be transmitted to the output shaft 12b via a predetermined gear mechanism without directly connecting the output shaft 12b. In this case, the ratio of the steering angle of the input shaft to the steering angle of the output shaft 12b, that is, the gear ratio, is large.
The steering force on the steering wheel is relatively small. Line a shows the case where the all-wheel suspension characteristics are controlled softly, and line b shows the case where the all-wheel suspension characteristics are controlled hard. On the other hand, lines c and d are input shaft 1
2a and the output shaft 12b are directly connected, that is, when the gear ratio is made small, line c shows the case where the all-wheel suspension characteristics are controlled to be soft, and line d shows the case where the all-wheel suspension characteristics are controlled to be hard. In either case, the steering angle and yaw rate are almost directly proportional. Furthermore, when the steering wheel steering angle is the same, the smaller the gear ratio, that is, the direct connection state, the larger the yaw rate, and the harder the suspension characteristics of the suspension device, the larger the yaw rate. By arbitrarily combining the suspension characteristics of the suspension and the steering characteristics of the manual steering, it is possible to obtain a steering feeling that matches the driver's preference.
In other words, the transmission characteristics a, b, c, and d between the steering wheel and the steering wheel are selected, and the switching is performed in accordance with the switching of the suspension characteristics between hard and soft.

As described above, the dynamic characteristics of the vehicle vary depending on changes in the suspension characteristics of the suspension device and the transmission characteristics between the steering wheel and the steering wheel.
By operating the manual switch, the driver can obtain the driving characteristics according to his/her preference.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view of a suspension device and a steering device according to one embodiment of the present invention, FIG. 2 is a control circuit diagram of the embodiment of FIG. 1, and FIG. 3 is another embodiment of the present invention. FIG. 4 is a diagram similar to FIG. 1 of the example, FIG. 4 is a diagram similar to FIG. 2 of the embodiment of FIG. 3, and FIG. 5 is a diagram similar to FIG.
A graph showing the relationship between steering force and yaw rate, and FIG. 6 is a graph showing the relationship between steering angle and yaw rate. Explanation of symbols, 10...Handle, 18...Rack shaft, 30...Power assist device, 36...Oil pump, 50...Controller, 54...Manual switch, 60...Suspension device, 66
...Shock absorber, 72...Controlled air chamber,
80...Gear mechanism.

Claims (1)

[Claims] 1. Simultaneously switching at least one of the suspension device of each wheel, the steering device that steers a steerable wheel among the wheels, and the damping force and spring constant of the suspension device. a first control means for changing suspension characteristics to either all-wheel hard or all-wheel soft; a second control means for changing transmission characteristics between a steering wheel of a steering device and a steering wheel; A first control signal for simultaneously switching at least one of the damping force and the spring constant of the steering device for all wheels is output to the first control means, and the transfer characteristic of the steering device is adjusted in accordance with the output of the first control signal. a controller that outputs a second control signal to be changed to the second control means, the controller:
A comprehensive suspension and steering control device, characterized in that it is configured to change the transmission characteristic of a steering device at the same time as the suspension characteristic of the suspension device changes.