JPH0769029A - Suspension control device for vehicle - Google Patents

Abstract

PURPOSE:To maintain riding comfort almost constant even in the initial stage of travel at cold time by selecting an adequate threshold value group, and weakening damping forces of dampers relatively when a travel distance after an engine is started is less than a preset distance and a water temperature of engine cooling water is lower than a preset temperature. CONSTITUTION:When a travel distance based on a signal taken in from a travel range finder 38 after a vehicle engine is started is judged as less than a preset distance (for example, 1km), and when a cooling water temperature by a water temperature gauge 37 is judged as lower than a preset temperature, a controller 25 judges that oil inside of oil dampers arranged with every wheel is cooled. In the initial stage of travel at cold time, a threshold value of vertical directional acceleration detected by a vertical acceleration sensor 19 is set in and changed to a second threshold value. Thereby, damping forces of the respective oil dampers are made hard to be put in a medium condition and a hard condition, and a phenomenon that the damping forces of the oil dampers become larger than usual is restrained, and riding comfort is maintained almost constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle suspension control device, and more particularly to a vehicle suspension control device suitable for improving the riding comfort at the initial stage of vehicle running in cold weather such as winter.

[0002]

2. Description of the Related Art Conventionally, in a vehicle equipped with a suspension control device, an anti-nose dive control for suppressing a nose dive phenomenon in which the nose is lowered when the vehicle is braked, a squat phenomenon in which the vehicle tail is lowered when the vehicle starts or suddenly accelerates Anti-squat control to suppress, steering stability control such as anti-roll control to suppress rolling phenomenon during cornering, and pitching / bouncing suppression control to suppress pitching phenomenon / bouncing phenomenon. Ride comfort control such as rough road response control when driving on rough roads is performed.

[0003]

By the way, the riding comfort of the vehicle is determined by various factors such as the specifications of the coil spring and the oil damper (shock absorber) constituting the suspension mechanism, the specifications of the tire, and the like. Among them, the ratio of the oil damper to the ride comfort of the vehicle is high, and the damping force of the oil damper that defines the ride comfort depends on the viscosity of the oil injected into the oil damper.

However, in the above-described conventional suspension control device, regardless of the change in the oil viscosity inside the oil damper (in other words, regardless of the temperature),
When the absolute value of the vertical acceleration acting on the vehicle becomes a predetermined value (for example, an absolute value of 0.2 [G]) or more, the damping force is set to the "medium state", and the predetermined value (for example, 0.3
Since the damping force was set to the "hard state" when the absolute value of [G] was exceeded, the oil inside the oil damper was cold especially at the initial stage of running the vehicle during cold weather such as winter. As a result, the damping force of the oil damper is more likely to enter the "medium state" or the "hard state" than in the normal time (when it is warm except winter), and as a result, there is a problem that the vehicle occupant feels a comfortable ride.

[0005]

An object of the present invention is to improve the inconvenience of the above-mentioned conventional example, and in particular, by making it difficult for the damping force of the oil damper to be in a high damping force state at the initial stage of traveling of the vehicle in cold weather such as winter. It is an object of the present invention to provide a vehicle suspension control device that improves the riding comfort of the vehicle.

[0006]

SUMMARY OF THE INVENTION The present invention provides a vertical acceleration measuring means for measuring vertical acceleration acting on a vehicle equipped with a suspension mechanism, and a mileage measurement for measuring a running distance of the vehicle after the engine is started. Means and water temperature measuring means for measuring the water temperature of the engine cooling water of the vehicle,
Corresponding to a set of first threshold value groups each having a plurality of positive and negative reference values centering on vertical acceleration 0 [G], and respective reference values of the first threshold value group And the absolute value of each of the set reference values has a value larger than the absolute value of each of the reference values of the first threshold value group. If the vertical acceleration measured by the stored storage means and the vertical acceleration measuring means is larger than the maximum reference value or smaller than the minimum reference value of the first threshold value group, or the second threshold value group. Control means for setting the damping force of the suspension mechanism to a high state for a predetermined time when the maximum reference value is larger than the maximum reference value or smaller than the minimum reference value, and the control means measures by the travel distance measuring means. The second threshold value group is selected when the running distance after engine start of the vehicle is less than a set distance and the water temperature of the engine cooling water measured by the water temperature measuring means is less than the set temperature. The configuration is such that it has a threshold value selection function. This aims to achieve the above-mentioned object.

[0007]

According to the present invention, when the vehicle shifts to the running state after the engine is started, the vertical acceleration measuring means measures the vertical acceleration with respect to the vehicle, and the running distance measuring means measures the running distance after the engine is started. The water temperature measuring means measures the water temperature of the engine cooling water. At this time, the control means selects the second threshold value group when the running distance after the engine start of the vehicle is less than the set distance and the water temperature of the engine cooling water of the vehicle is less than the set temperature.

That is, when the water temperature of the engine cooling water of the vehicle is less than the set temperature and the traveling distance after the engine is started is less than the set distance, in other words, when the vehicle is in the initial stage of traveling in cold weather such as winter. Is the vertical acceleration 0
Each reference value is set corresponding to each reference value of a set of first threshold value groups having a plurality of positive and negative reference values centered on [G], and each set reference value. The vertical acceleration is the first threshold value for selecting a set of second threshold groups each having an absolute value greater than the absolute value of each reference value of the first threshold group. When the value is larger than the maximum reference value of the group or smaller than the minimum reference value or larger than the maximum reference value of the second threshold group or smaller than the minimum reference value, the damping force of the suspension mechanism is set to a high state for a predetermined time. At the time of control, it is possible to make it difficult to enter a higher damping force of the suspension mechanism at the initial stage of traveling in cold weather such as winter. Therefore, for example, in the case where the suspension mechanism is hydraulic, even when the oil inside the suspension mechanism is cold at the initial stage of vehicle running in cold weather such as winter, the riding comfort is kept substantially constant as when the oil is warm. It becomes possible to keep.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment to which the vehicle suspension control device of the present invention is applied will be described below with reference to the drawings.

First, the structure of the main part of a vehicle equipped with the vehicle suspension control device of this embodiment will be described with reference to FIG. 2. In the vicinity of the right front wheel of the vehicle 1, the oil damper 3,
A suspension mechanism 2 including a coil spring 4 and an actuator 5 is arranged, a suspension mechanism 6 including an oil damper 7, a coil spring 8 and an actuator 9 is arranged near the left front wheel, and near the right rear wheel. Is provided with a suspension mechanism 10 including an oil damper 11, a coil spring 12, and an actuator 13, and a suspension mechanism 14 including an oil damper 15, a coil spring 16, and an actuator 17 is provided near the left rear wheel. It is set up.

Inside the vehicle 1, a steering sensor 18 for detecting a steering angle, a vertical acceleration sensor 19 for detecting a vertical acceleration acting on the vehicle, a vehicle speed sensor 20 for detecting a vehicle speed, and a vehicle driver. A throttle sensor 21 for detecting the throttle opening based on the accelerator pedal depression operation, a brake switch 22 for detecting the brake operation state based on the vehicle driver's brake pedal depression operation, and an engine rotation speed signal An ignition coil 23, a water temperature gauge 37 for displaying a water temperature of engine cooling water, an odometer 38 for displaying a mileage of a vehicle, and an electronic suspension controller 25 (hereinafter abbreviated as a controller) for suspension control are provided. Has been done.

Next, the structure of the vehicle suspension control system of this embodiment will be described with reference to FIG. 1. The controller 25 has a battery 28 through fuses 26 and 27.
And the ignition switch 30 via the fuse 29.
, The brake switch 22, the stop lamp 31 that lights up when the brake is operated, and the auto / sport switch 3
2, the DN switch 33, and the ignition coil 23
, Noise filter 34, sport / auto lamp 3
5 and 5 are connected to each other.

Further, the controller 25 includes a vehicle speed sensor 20, a steering sensor 18, a vertical acceleration sensor 19, a throttle sensor 21, an engine control controller (EPI controller) 36, and a water temperature gauge 37.
, Odometer 38, each oil damper 3, 7, 11,
The actuators 5, 9, 13, and 17 for setting the damping force of 15 to a predetermined state (“hard state”, “soft state”, “medium state”) are respectively connected.

The controller 25 determines the steering operation state based on the output signal of the steering sensor 18, determines the degree of vertical acceleration acting on the vehicle based on the output signal of the vertical acceleration sensor 19, and detects the vehicle speed sensor 2.
The degree of vehicle speed is determined based on the output signal of 0, the degree of throttle opening (unit [deg]) is determined based on the output signal of the throttle sensor 21, and the brake switch 22
The operating condition of the brake is determined based on the output signal of the engine, the water temperature of the engine cooling water is determined based on the signal captured from the water temperature gauge 37 through the electric wiring, and the temperature is captured from the odometer 38 through the electrical wiring. The distance traveled after the engine of the vehicle is started is determined based on the signal.

The characteristic points of this embodiment will now be described. FIG. 3 shows a first threshold value (FIG. 3) relating to vertical acceleration acting on the vehicle detected by the vertical acceleration sensor 19.
It is a figure which shows (a)) and a 2nd threshold value (FIG.3 (b)), and is memorize | stored in the memory 39 incorporated in the controller 25. As will be described later, the controller 25 sets the threshold value of the vertical acceleration detected by the vertical acceleration sensor 19 in accordance with the traveling distance after the engine start of the vehicle and the water temperature of the engine cooling water, as described above. The setting is changed to a value or a second threshold. The curved line in the figure indicates the vertical acceleration detected by the vertical acceleration sensor 19 when the vehicle is traveling.

In this case, when the first threshold value is used while the vehicle is running (when the oil in the oil damper is warm), the detected vertical acceleration is equal to or greater than the absolute value of 0.2 [G]. In case of oil damper 3,7,11,15
Set the damping force of "medium" to 0.3 [G]
If the absolute value of the above is exceeded, each oil damper 3, 7, 1
The damping forces of 1 and 15 are set to the "hard state". When the second threshold value is used when the vehicle is traveling (when the oil in the oil damper is cold), the absolute value of the measured vertical acceleration is equal to or greater than the absolute value of 0.25 [G]. Sets the damping force of each oil damper 3,7,11,15 to "medium state", 0.35 [G]
If the absolute value of the above is exceeded, each oil damper 3, 7, 1
The damping forces of 1 and 15 are set to the "hard state".

To explain this in detail, the controller 25
When it is determined that the mileage after the engine start of the vehicle based on the signal acquired from the odometer 38 is less than the set distance (for example, 1 km), the temperature of the engine cooling water based on the signal acquired from the water temperature meter 37 is set to the set temperature. When it is determined that the temperature is lower than the (water temperature threshold value), it is determined that the oil inside each oil damper 3, 7, 11, 15 is cold, and the vertical acceleration sensor 1
The threshold value of the vertical acceleration detected by 9 is changed to the second threshold value, and each oil damper 3, 7, 11, 1
The damping force of 5 is hard to enter the "medium state" and the "hard state" (because the upper and lower limits of the second threshold are smaller than the upper and lower limits of the first threshold). ).

As a result, the damping force of the oil damper becomes larger than that at the normal time, because the oil inside the oil damper is cold as in the conventional case, especially at the initial stage of running of the vehicle in cold weather such as winter, so that the occupant of the vehicle is not affected. It suppresses the phenomenon that the ride comfort is felt tight and controls the ride comfort to be substantially constant. In this case, the predetermined traveling distance (for example, 1 km) after starting the engine of the vehicle and the set temperature of the engine cooling water temperature are set to the respective oil dampers 3, 3.
It is a reference for determining whether the oil inside 7, 11, 15 is cold or warm.

On the other hand, the controller 25 uses the odometer 3
When it is determined that the running distance after the engine start of the vehicle based on the signal taken from 8 is more than the set distance (for example, 1 km), it is determined that the water temperature of the engine cooling water based on the signal taken from the water temperature gauge 37 is not less than the set temperature. In this case, it is determined that the oil inside each oil damper 3, 7, 11, 15 is warm, and the threshold value of the vertical acceleration detected by the vertical acceleration sensor 19 is set to the first threshold value. It is like this.

Next, an example of suspension control in this embodiment having the above-mentioned configuration will be described with reference to FIG.

The controller 25 mounted on the vehicle 1 is
Based on the signal taken from the odometer 38, it is determined whether or not the mileage of the vehicle 1 after the engine is started is equal to or longer than a set distance (for example, 1 km) (step S1), and the mileage after the vehicle engine is started is determined. If the distance exceeds the set distance (for example, 1 km), it is determined that the oil inside the oil dampers 3, 7, 11, and 15 has warmed up, and step S described later is performed.
9 is executed, while the running distance after the vehicle engine is started is less than the set distance (for example, 1 km), the engine cooling water temperature is set to the set temperature (water temperature based on the signal taken from the water temperature gauge 37). It is determined whether or not the threshold value is exceeded (step S2).

The controller 25 controls the oil dampers 3, when the temperature of the engine cooling water exceeds the set temperature.
It is judged that the oil inside 7, 11, 15 is warm,
On the other hand, if the water temperature of the engine cooling water is lower than the set temperature while executing the processing of step S9 and later described later, it is determined that the oil inside the oil dampers 3, 7, 11, 15 is cold, and the vertical acceleration sensor 19 The threshold value of the vertical acceleration detected by is changed to the second threshold value (see FIG. 3B) (step S3).

That is, the controller 25 sets the damping force of each oil damper 3, 7, 11, 15 to "medium" when the absolute value of the detected vertical acceleration exceeds the absolute value of 0.25 [G]. When the absolute value of the vertical acceleration detected is equal to or greater than the absolute value of 0.35 [G], the damping force of each oil damper 3, 7, 11, 15 is set to the “hard” state. Therefore (that is, by changing the normal first threshold value to the second threshold value), when the oil inside each oil damper 3, 7, 11, 15 is cold, each oil damper 3,7,11,15 damping force is "medium" than when using the first threshold
It is difficult to enter the state or "hard state".

Next, the controller 25 determines that the absolute value of the vertical acceleration detected by the vertical acceleration sensor 19 is 0.
It is determined whether or not the absolute value is 25 [G] or more (step S4), and the absolute value of the vertical acceleration is 0.25 [G].
If less than the absolute value of, each actuator 5, 9, 1
The operation of the oil dampers 3, 17 is controlled to control the oil dampers 3, 7, 1
The damping forces of 1 and 15 are set to the "soft state" (step S5).

If the absolute value of the vertical acceleration is greater than or equal to 0.25 [G] in the determination in step S4, the controller 25 further determines the vertical acceleration to be 0.35.
It is determined whether or not the absolute value of [G] is greater than or equal to the absolute value (step S6). If the absolute value of the vertical acceleration is less than the absolute value of 0.35 [G], each actuator 5, 9, 13, 1
7, the operation of each oil damper 3, 7, 11, 15
For example, after setting the damping force of 2 to the "medium state" for 2 seconds and then returning to the "soft state" (step S7), if the vertical acceleration is equal to or greater than the absolute value of 0.35 [G], After controlling the operation of 5, 9, 13, 17 and holding the damping force of each oil damper 3, 7, 11, 15 in the "hard state" for 2 seconds, for example, the "soft state"
(Step S8).

On the other hand, the controller 25 determines in step S1.
When the traveling distance after the vehicle engine is started is equal to or more than the set distance (for example, 1 km) in the determination of No.
It is determined that the oil inside each oil damper 3, 7, 11, 15 is warm, and the threshold value of the vertical acceleration detected by the vertical acceleration sensor 19 is the first threshold value (see FIG. 3).
(See (a)) (step S9).

That is, the controller 25 "medium" the damping force of each oil damper 3, 7, 11, 15 when the absolute value of the detected vertical acceleration is equal to or greater than the absolute value of 0.2 [G]. When the absolute value of the vertical acceleration exceeds the absolute value of 0.3 [G], the damping force of each oil damper 3, 7, 11, 15 is set to the “hard” state. In this case, the oil dampers 3, 7, 11, 1
A damping force of 5 is more likely to enter the "medium" or "hard" state than when using the second threshold.

Next, the controller 25 determines that the absolute value of the vertical acceleration detected by the vertical acceleration sensor 19 is 0.
It is determined whether the absolute value of 2 [G] or more is reached (step S10). If the absolute value of the vertical acceleration is less than the absolute value of 0.2 [G], each actuator 5, 9, 13,
17 to control the operation of each of the oil dampers 3, 7, 11, 1
The damping force of 5 is set to "soft state" (step S1)
1).

If the absolute value of the vertical acceleration is 0.2 [G] or more in the determination of step S10, the controller 25 further determines that the vertical acceleration is 0.3 [G]. Is determined to be equal to or greater than the absolute value of (step S12), and the absolute value of the vertical acceleration is 0.3.
If it is less than the absolute value of [G], each actuator 5,
The operation of 9, 13, 17 is controlled, and each oil damper 3,
After holding the damping force of 7, 11, and 15 in the "medium state" for 2 seconds, for example, while returning to the "soft state" (step S13), the absolute value of the vertical acceleration is equal to or greater than the absolute value of 0.3 [G]. In case of, each actuator 5, 9,
The operation of 13, 17 is controlled, and each oil damper 3, 7, 1
The damping forces of 1 and 15 are held in the "hard state" for 2 seconds, for example, and then returned to the "soft state" (step S14). The above is the flow of suspension control in the present embodiment.

As described above, according to this embodiment, the running distance of the vehicle after the engine is started is the set distance (for example, 1K).
If it is less than m) and the water temperature of the engine cooling water is less than the set temperature, it is determined that the oil inside each oil damper 3, 7, 11, 15 is cold, and the threshold value of the vertical acceleration is set to The first threshold value (normal threshold value) is changed to the second threshold value, and each oil damper 3, 7, 11, 15 is changed.
Even if the oil inside each oil damper 3,7,11,15 is cold at the initial stage of running the vehicle in cold weather such as winter, It is possible to keep the riding comfort substantially constant as when the oil is warm.

That is, in this embodiment, since the threshold value of the vertical acceleration is changed in accordance with the traveling distance and the water temperature at the initial stage of traveling of the vehicle in cold weather such as winter, the oil dampers 3, 7, 11 are changed. It is possible to correct the viscosity change of the oil inside the oil damper 15. As a result, the oil inside the oil damper is cooled at the initial stage of vehicle running during cold weather such as winter, as in the conventional case, and the oil damper is damped. It is possible to solve the problem that the force becomes stronger than usual and the rider feels a comfortable ride.

Further, according to this embodiment, signals are fetched from the vertical acceleration sensor 19, the water temperature gauge 37 and the odometer 38 which are preliminarily installed in the vehicle to perform the suspension control of FIG. It is possible to configure the suspension control device of the present embodiment at low cost without the need to add components such as sensors.

In this case, in this embodiment, the first threshold value and the second threshold value relating to the vertical acceleration sensor 19 are set to the numerical values shown in FIG. 3 above, but the numerical values are not limited to these numerical values. Absent.

Further, in this embodiment, each oil damper 3,
Although the predetermined traveling distance after the engine is started during the traveling of the vehicle, which serves as a criterion for determining whether the oil inside 7, 11, and 15 is cold or warm, is set to 1 km, the present invention is not limited to this value.

Further, in the present embodiment, in steps S7, S8, S13, S14 in FIG. 4, the damping force of each oil damper 3, 7, 11, 15 is set to "medium state" or "hard state" for 2 seconds. The control to return to the "soft state" after holding was performed, but the time to maintain the "medium state" or "hard state" is not limited to 2 seconds, but any time (short time in seconds) Can be set to.

[0036]

As described above, according to the vehicle suspension control device of the present invention, when the water temperature of the engine cooling water of the vehicle is less than the set temperature and the traveling distance after the engine is started is less than the set distance, that is, When the vehicle is in an early stage of running in cold weather such as winter, a set of first threshold values each having a plurality of positive and negative reference values centering on the vertical acceleration 0 [G] is provided. A set of values that are set respectively corresponding to the respective reference values of the group and whose absolute values of the respective set reference values are respectively greater than the absolute values of the respective reference values of the first threshold value group. In order to select the second threshold group, when the vertical acceleration is greater than the maximum reference value of the first threshold group or less than the minimum reference value, or greater than the maximum reference value of the second threshold group. Or minimum When the damping force of the suspension mechanism is set to a higher value for a predetermined time when the value is smaller than the value, it is possible to prevent the damping force of the suspension mechanism from entering a higher value at the initial stage of running in cold weather such as winter. Therefore, if the suspension mechanism is hydraulic, for example, even when the oil inside the suspension mechanism is cold at the initial stage of vehicle running in cold weather such as winter, the ride comfort is almost the same as when the oil is warm. The effect that it can be kept constant can be achieved.

Further, in the vehicle suspension control device of the present invention, the second threshold value group is set to the first when the running distance after the engine is started is equal to or more than the set distance and the temperature of the engine cooling water is equal to or more than the set temperature. When the suspension mechanism is equipped with a hydraulic system, for example, when the suspension mechanism is a hydraulic system, the oil inside the suspension mechanism will be removed during the normal driving stage after the vehicle starts running in cold weather such as winter. When it gets warm, the damping force of the suspension mechanism can be controlled accordingly, so that an appropriate riding comfort can be ensured.

[Brief description of drawings]

FIG. 1 is a control block diagram showing a configuration of a main part of a vehicle in the present embodiment to which the present invention is applied.

FIG. 2 is a schematic diagram showing a configuration of a main part of a vehicle in the present embodiment.

FIG. 3 is a diagram showing a first threshold value and a second threshold value relating to vertical acceleration and measured vertical acceleration in the present embodiment.

FIG. 4 is a flow chart of suspension control in the present embodiment.

[Explanation of symbols]

2,6,10,14 Suspension mechanism 3,7,11,15 Oil damper 4,8,12,16 Coil spring 5,9,13,17 Actuator 19 as a main part of suspension mechanism Vertical acceleration sensor 25 Controller as control means 37 Water thermometer as water temperature measurement means 38 Odometer as mileage measurement means 39 Memory as storage means

Claims (2)

[Claims] 1. A vertical acceleration measuring means for measuring a vertical acceleration acting on a vehicle equipped with a suspension mechanism, a running distance measuring means for measuring a running distance of the vehicle after the engine is started, and an engine cooling of the vehicle. A water temperature measuring means for measuring the water temperature of water, a set of first threshold value groups each having a plurality of positive and negative reference values centered on a vertical acceleration of 0 [G], and the first threshold value group. The threshold value is set corresponding to each reference value of the threshold group, and the absolute value of each set reference value is larger than the absolute value of each reference value of the first threshold group. Storage means for storing a set of second threshold groups;
When the vertical acceleration measured by the vertical acceleration measuring means is larger than the maximum reference value of the first threshold group or smaller than the minimum reference value, or larger than the maximum reference value of the second threshold group. Or a control means for setting the damping force of the suspension mechanism to a higher state for a predetermined time when the value is smaller than the minimum reference value, the control means after starting the engine of the vehicle measured by the mileage measuring means. Is less than the set distance,
Further, the vehicle suspension control is provided with a threshold value selecting function for selecting the second threshold value group when the water temperature of the engine cooling water measured by the water temperature measuring means is lower than a set temperature. apparatus. 2. A vertical acceleration measuring means for measuring a vertical acceleration acting on a vehicle equipped with a suspension mechanism, a running distance measuring means for measuring a running distance of the vehicle after the engine is started, and an engine cooling for the vehicle. A water temperature measuring means for measuring the water temperature of water, a set of first threshold value groups each having a plurality of positive and negative reference values centered on a vertical acceleration of 0 [G], and the first threshold value group. The threshold value is set corresponding to each reference value of the threshold group, and the absolute value of each set reference value is larger than the absolute value of each reference value of the first threshold group. Storage means for storing a set of second threshold groups;
When the vertical acceleration measured by the vertical acceleration measuring means is larger than the maximum reference value of the first threshold group or smaller than the minimum reference value, or larger than the maximum reference value of the second threshold group. Or a control means for setting the damping force of the suspension mechanism to a higher state for a predetermined time when the value is smaller than the minimum reference value, the control means after starting the engine of the vehicle measured by the mileage measuring means. A traveling distance determining function for determining whether the traveling distance is less than a set distance, and a water temperature determining function for determining whether the water temperature of the engine cooling water measured by the water temperature measuring means is less than a set temperature, The control means further selects a threshold value for selecting the second threshold value group when the travel distance is less than the set distance and the water temperature is less than the set temperature. -Option function and the travel distance is the predetermined distance or more or the first and second threshold groups when the water temperature becomes the set temperature or more
And a threshold value switching function for switching to the threshold value group of the vehicle suspension control device.