JPH0815869B2 - Power steering device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a power steering device in which steering stability and directional stability are improved by making handling heavy when starting or suddenly accelerating.

(Prior Art) The conventional power steering device is good at low speed,
At high speeds, the steering was too light and the maneuverability was unstable.

For this reason, various vehicle speed-sensitive power steering devices have been proposed in which the weight of the steering wheel is variable depending on the vehicle speed.

FIG. 6 is a block diagram showing a conventional example of a speed-sensitive power steering device, FIG. 7 is a diagram for explaining a power assist amount used in the conventional example device, and FIG. FIG. 9 is a conceptual diagram showing a conventional device, and FIG. 9 is an enlarged external view showing a steering gear portion of the conventional device.

In FIG. 6, 1 is a vehicle speed sensor, 2 is a torque sensor, 3 is a controller, 4 is a driver, 5 is an actuator, and 6 is a steering gear.

The vehicle speed sensor 1 is a sensor that detects the traveling speed of the vehicle. The torque sensor 2 is a sensor for detecting steering torque, and is attached to the steering gear 6 as shown in FIG.

The outputs of the vehicle speed sensor 1 and the torque sensor 2 are connected to the controller 3, respectively. In controller 3,
The power assist amount is determined from the steering torque of the steering gear 6 detected by the torque sensor 2 and the vehicle speed detected by the vehicle speed sensor 1.

As shown in FIG. 7, the power assist amount is variable so as to increase when the vehicle speed is low and decrease when the vehicle speed is high. Therefore, in the high speed range, the amount of assist can be reduced and the steering can be controlled to be heavy.

The controller 3 drives the actuator 5 via the driver 4 by the control signal based on the assist amount. The actuator 5 is for assisting the steering operation in accordance with the power assist amount, and for example, an electric motor is used.

The output shaft of the actuator 5 is provided with a speed reducer 5a, and the output reduced by the speed reducer 5 is connected to a rack 6a that meshes with the steering gear 6. In addition,
8 is a case, 9 is a steering wheel, and 10 is a tire.

(Problems to be solved by the invention) However, even in the speed-sensitive power steering device as described above, no special consideration is given when starting or suddenly accelerating. There was a problem that the sex deteriorates.

An object of the present invention is to provide a power steering device capable of improving maneuverability and directional stability by making a steering wheel heavy when starting or suddenly accelerating.

(Means for Solving Problems) In order to achieve the above object, a power steering device according to the present invention includes a throttle sensor that detects a throttle opening, a vehicle speed sensor that detects a vehicle running speed, and a steering torque. The first assist amount and the acceleration determined from the throttle opening and the steering torque, based on the torque sensor, the throttle opening speed calculated from the output of each sensor and the throttle opening, and the acceleration calculated from the vehicle speed. The second assist amount determined from the steering torque and the steering torque, and the third assist amount determined from the vehicle speed and the steering torque are obtained, and the smallest one of the first to third assist amounts is set as the actual assist amount. , A controller that outputs a control signal that makes the steering heavier at the time of sudden acceleration when starting, and steering by the output of the controller. It is composed of an actuator that assists the ring.

(Examples) Hereinafter, the present invention will be described in detail with reference to the drawings and the like.

FIG. 1 is a block diagram showing an embodiment of a power steering device according to the present invention, FIG. 2 is a flow chart showing the operation of a controller of the device of the same embodiment, and FIGS.
It is the figure which showed the control map each used by the said controller.

In this embodiment, the same reference numerals are given to the parts that perform the same functions as the above-mentioned conventional example.

The throttle sensor 7 newly added in the present invention is a sensor for detecting the throttle opening.

The outputs of the vehicle speed sensor 1, the torque sensor 2, and the throttle sensor 7 are connected to the controller 3. The controller 3 is for generating a control signal based on the power assist amount determined according to the flowchart of FIG. 2 with reference to the maps of FIGS. 3 to 5 described later. The output of the controller 3 is connected to the actuator 5 via the driver 4.

Next, the operation of the power steering device according to the present invention will be described focusing on the flowchart of the controller 3 shown in FIG.

The throttle opening signal from the throttle sensor 7, the vehicle speed signal from the vehicle speed sensor 1, and the steering torque signal from the torque sensor 2 are input to the controller 3 (101).

The controller 3 calculates the throttle opening speed from the throttle opening signal (102), and further calculates the acceleration from the vehicle speed signal (103).

Next, the power assist amount A is determined from the map 1 from the throttle opening speed and the steering torque (104). Map 1
3 is a map in which the power assist amount A appears on the vertical axis due to the steering torque on the horizontal axis and the throttle opening speed as shown in FIG. 3, and the assist amount decreases as the throttle opening speed increases. That is, when the accelerator is suddenly depressed such as at the time of starting or sudden acceleration, the assist amount is reduced and the steering wheel is controlled to be heavier.

In addition, the power assist amount B is calculated by the acceleration and the steering torque.
Is determined from the map 2 (105). Map 2 is the 4th
As shown in the figure, the map is such that the power assist amount B appears on the vertical axis by the steering torque and acceleration on the horizontal axis.
The larger the acceleration, the smaller the assist amount. In other words, when the accelerator is suddenly depressed, such as during sudden acceleration, the number of passengers and the load are large, and the case where the throttle opening speed is not supported is taken into consideration. Also in this case, when the acceleration is large, the assist amount is reduced and the steering wheel is controlled to be heavy.

Further, the power assist amount C is calculated from the vehicle speed and the steering torque.
Is determined from the map 3 (106). This map 3
As shown in FIG. 5, the map is such that the power assist amount C appears on the vertical axis from the steering torque and vehicle speed on the horizontal axis.
This is similar to a conventional map.

Finally, the smallest one of the power assist amounts A, B, C calculated in steps 104 to 106 is selected and output to the driver 4 as the actual assist amount (107).

The driver 4 drives the actuator 5 according to the control signal from the controller 3 so that the assist amount is calculated.

Therefore, in addition to the conventional control only for vehicle speed, the power assist amount is determined based on the throttle opening speed and acceleration, and the steering wheel can be controlled to be heavier when it is determined that the vehicle is starting or suddenly accelerating. .

(Effects of the Invention) As described in detail above, according to the present invention, the assist amount is determined in consideration of the throttle opening speed and the traveling acceleration, so that the steering stability and the directional stability at the start can be improved. You can In addition, steering stability at the time of sudden acceleration, that is, when the accelerator is stepped on can be similarly improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a power steering device according to the present invention, FIG. 2 is a flow chart showing the operation of a controller of the device of the same embodiment, and FIGS.
It is the figure which showed the control map each used by the said controller. FIG. 6 is a block diagram showing a conventional example of a speed-sensitive power steering device, FIG. 7 is a diagram for explaining the power assist amount used in the conventional example device, and FIG. 8 is the same. FIG. 9 is a conceptual diagram showing a conventional device, and FIG. 9 is an enlarged external view showing a steering gear portion of the conventional device. 1 ... Vehicle speed sensor, 2 ... Torque sensor, 3 ... Controller, 4 ... Driver, 5 ... Actuator, 6 ... Steering gear, 7 ... Throttle opening sensor, 8 ... Gear box, 9 ... Steering, 10 ... tire

Claims (1)

[Claims] 1. A throttle sensor for detecting a throttle opening, a vehicle speed sensor for detecting a traveling speed of a vehicle, a torque sensor for detecting a steering torque, and a throttle calculated from an output from each sensor and a throttle opening. Based on the acceleration calculated from the opening speed and the vehicle speed, the first assist amount determined from the throttle opening and the steering torque, the second assist amount determined from the acceleration and the steering torque, and the vehicle speed and the steering torque. A controller that outputs a control signal that makes the steering heavier at the time of sudden acceleration at the time of starting, with the smallest assist amount among the first to third assist amounts as the actual assist amount. A power steering device comprising an actuator that assists steering by the output of the controller.