JPH05338577A - Damping force control device of suspension for motorcycle - Google Patents

Abstract

PURPOSE:To provide the damping force control device of a suspension for a motorcycle which can insure appropriate damping force by simple construction. CONSTITUTION:The damping force control device of a suspension for a motorcycle is constituted of a vehicle speed detecting means 16, a reference damping force setting means 31 by which the damping force of a front side and a rear side shock absorbers 13, 10 are set to reference values (reference damping force) in response to the case of turning a corner of decided curvature at the detected vehicle speed, and a damping force correcting means 32 by which the above-stated reference damping force is corrected according to the road surface condition or the posture of the vehicle. The damping force correcting means 32 is constituted of a stroke position detecting means 14, an expansion/contraction speed computing means 33, a first damping force correcting means 34, a road surface condition estimating means 35, and a second damping force correcting means 36, otherwise, detecting means 17, 18 to detect brake pressure of the front and rear wheels, a deceleration computing means 38, a posture change mode setting means 39 to set the change mode of a vehicle posture from the obtained deceleration, and a damping force correcting means 40 to correct into the damping force in response to the set posture change mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping force control device for a motorcycle suspension, and more particularly to an improvement of a damping force setting method for obtaining an appropriate damping force according to a running condition with a simple structure. ..

[0002]

2. Description of the Related Art Conventionally, as a damping force control device for an automobile suspension, a number of sensors such as a steering angle sensor, a lateral G sensor, a vertical acceleration sensor, etc.
There is a device in which an appropriate damping force corresponding to the running state of the vehicle is obtained (for example, Japanese Patent Laid-Open Nos. 60-193710 and 61-1519).

[0003]

However, the above-mentioned conventional control device is for a four-wheeled vehicle, and is employed as it is as a damping force control device for a motorcycle, which is premised to incline the vehicle body when turning a corner. It is not possible. Further, the above conventional device has a problem that the structure is complicated and the cost is high, and it is not suitable for a vehicle having a relatively low price such as a motorcycle.

The present invention has been made in view of the above conventional circumstances, and an object of the present invention is to provide a damping force control device for a suspension for a motorcycle which can ensure an appropriate damping force with a simple structure.

[0005]

The invention according to claim 1 is based on FIG.
As shown in (a), the damping force of the vehicle speed detecting means 16 and the front and rear shock absorbers 13 and 10 is set to a value (reference damping force) corresponding to the case of turning at a corner of a predetermined curvature at the detected vehicle speed. A damping force control device for a suspension for a motorcycle, comprising: a reference damping force setting means 31 for setting; and a damping force correction means 32 for correcting the reference damping force according to a road surface condition or a vehicle attitude. ..

According to a second aspect of the invention, as shown in FIG. 1B, the damping force correcting means 32 is provided in the front shock absorber 1.
Stroke position detection means 14 for detecting the stroke position of No. 3, and expansion / contraction speed calculation means 33 for calculating the expansion / contraction speed of the front shock absorber 13 when the absolute value of the difference between the detected stroke position and the average stroke position is equal to or greater than the reference value. Front shock absorber 1
The first damping force correction means 34 for correcting the reference damping force of No. 3 into the corrected damping force according to the expansion / contraction speed, and the road surface condition is predicted when the absolute value of the difference between the detected stroke position and the average stroke position is equal to or greater than the reference value. A suspension for a motorcycle, which comprises a road surface condition predicting means 35 and a second damping force correcting means 36 for correcting the reference damping force of the rear shock absorber 14 into a corrected damping force according to the prediction. It is a damping force control device.

Further, the invention of claim 3 is the one shown in FIG.
As shown in FIG. 3, the damping force correction means 32 is provided with detection means 17 and 18 for detecting the brake pressures of the front and rear wheels, and a deceleration for obtaining a deceleration from the detected brake pressure when the detected brake pressure is a reference value or more. A calculation means 38, an attitude change mode setting means 39 for setting a change mode of the vehicle attitude from the obtained deceleration, and a damping force correction means for correcting the reference damping force to a damping force according to the set attitude change mode. 40 is a damping force control device for a motorcycle suspension.

[0008]

According to the damping force control device for a motorcycle suspension of the first aspect of the present invention, the damping force of the shock absorber is detected during straight running or turning normal running on a relatively flat road surface. It is set to a value (reference damping force) that takes into account the substantial increase in sprung load during cornering at vehicle speed. On the other hand, if there is a change in the road surface condition due to a manhole or the like, or a change in the vehicle attitude due to a braking operation, the reference damping force is corrected to a corrected damping force corresponding to the change.

According to the second aspect of the invention, the correction operation is performed in the following procedure. For example, when riding over a convex portion such as a manhole on the road, if the absolute value of the difference between the detected stroke position and the average stroke position exceeds the reference value, the expansion / contraction speed of the front shock absorber is calculated and the front shock absorber The reference damping force is corrected to the correction damping force according to the expansion / contraction speed. Further, the damping force of the rear shock absorber is corrected to the corrected damping force obtained from the prediction based on the absolute value of the difference.

According to the third aspect of the invention, the correction operation is performed in the following procedure. When the brake pressure is equal to or higher than the reference value, the deceleration is calculated from the brake pressure, the vehicle attitude change mode is set based on the deceleration, and the reference damping force is corrected to the corrected damping force according to the attitude change mode. It

As described above, according to the present invention, during normal straight traveling and turning traveling, the reference damping force is set according to the vehicle speed and the centrifugal force at the time of turning is taken into consideration so that the vehicle can ride on a convex portion on the road. When the vehicle falls into a recess or when the vehicle posture changes due to braking, the damping force is corrected to the correct damping force according to the expansion / contraction speed of the shock absorber or the posture change mode. Force characteristics are obtained.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 2 to 4 are views for explaining a damping force control device for a motorcycle suspension according to an embodiment of the present invention. FIG. 2 is a block diagram, FIG. 3 is a flowchart diagram, and FIG. 4 is a motorcycle. It is a side view.

In FIG. 4, reference numeral 1 denotes a motorcycle equipped with the device of the embodiment, which is provided with a front fork (front suspension) 3 pivotally supported left and right by a head pipe 2a of a body frame 2. Pivot the front wheel 4,
A rear arm 6 pivotally supported by a rear arm bracket 2b of the vehicle body frame 2 is pivotally supported up and down to pivotally support a rear wheel 6, and an engine 7 is suspended and supported on a lower side of a central portion of the vehicle body frame 2 and a fuel is provided on an upper side thereof. It has a structure in which the tank 8 is mounted.

A link mechanism 11 connects the rear arm 6 and the lower end of the rear arm bracket 2b. A rear shock absorber 10 including a shock absorbing spring and a damping damper is provided between the link mechanism 11 and the upper portion of the rear arm bracket 2b. A rear suspension 12 is composed of the rear arm 6, the link mechanism 11, and the rear shock absorber 10.

The front fork 3 comprises a pair of left and right telescopic fork bodies 3a, 3a, the upper portions of which are connected and fixed by a pair of upper and lower brackets 3b, 3b. A front shock absorber 13 including a damper is built in.

An F suspension stroke sensor 14 for detecting the stroke position of the front fork 3 is mounted on the upper portion of the front fork 3, and the body frame 2 is further mounted.
An F-side sprung acceleration sensor 15 for detecting the vertical acceleration of the sprung portion of the front shock absorber 13 is disposed near the head pipe 2a.

At the lower end of the front fork 3, a vehicle speed sensor 16 for detecting the vehicle speed based on the rotation speed of the front wheel 4 is provided.
Is installed. Furthermore, the hydraulic cylinder 23 of the front brake 22 that brakes the front wheels 4 has a front brake pressure sensor 1 that detects the hydraulic pressure in the cylinder 23.
7 are provided. Although not shown in FIG. 4, a rear brake hydraulic pressure sensor 18 for detecting the hydraulic pressure in the rear brake hydraulic cylinder for the rear wheel 6 is used.
(See FIG. 2).

The link mechanism 11 of the rear suspension 12 is equipped with an R suspension stroke sensor 19 for detecting the stroke position of the rear shock absorber 10 based on the rotation angle of the support shaft 11a of the link mechanism 11. An R-side sprung acceleration sensor 20 is mounted on the seat rail 2c of the vehicle body frame 2 to detect the vertical acceleration of the sprung portion of the vehicle body rear portion.

A control unit 21, which constitutes a main part of the apparatus of this embodiment, is disposed below the seat of the vehicle body frame 2. As shown in FIG. 2, the control unit 21 includes a main CPU 2 to which the detection signals of the sensors 14 to 20 are input via the input interfaces 26.
4, a sub CPU 25, and both CPUs 24, 2
Reference numeral 5 includes arithmetic units 24a and 25a that perform the same arithmetic operation in duplicate. Each of the calculation units 24a and 25a includes the reference damping force setting means 31, the expansion / contraction speed calculation means 33, the first damping force correction means 34, the road surface condition prediction means 35, the second damping force correction means 36, and the deceleration. It has various functions such as a calculation means 38, a posture change mode calculation means 39, and a third damping force correction means 40.

The main CPU 24 is connected to the sub C
Judgment unit 2 which makes a failure judgment by arithmetic comparison with PU25
4c, and a control signal corresponding to the calculation result from the judging section 24c and the calculating section 24a.
Front and rear suspension solenoid valves 28 through 7
a, 28b, and a controller 24b for outputting to the abnormality warning device 28c.

Next, the operation of the apparatus of this embodiment will be described with reference to the flow chart shown in FIG. When the main switch is turned on, the program starts and the vehicle speeds Vi, F, R suspension stroke positions Sf, Sr,
Various data such as F, R brake pressures Pfi, Pri, F, R sprung acceleration are read (step S1).

It is judged whether or not the vehicle speed Vi is within a range of a predetermined low speed Vmin to a lower limit speed Vo (step S2). If the vehicle speed Vi is outside the range, the sampling speed Tj is immediately reached. After the passage of, the F, R average stroke positions Sfa, Sra are calculated. These values are values obtained by averaging the stroke fluctuation amounts Sfi and Sri. (Step S3).

Then, the reference damping forces Ff and Fr of the front and rear shock absorbers 13 and 10 corresponding to the detected vehicle speed Vi are set (step S4), and a control signal corresponding to the reference damping force is transmitted to the interface 27. Through solenoid valve 28
a and 28b.

Here, the reference damping force is the built-in vehicle speed-
It is read from the damping force map (see FIG. 3A). This vehicle speed-reference damping force map sets an optimal damping force when a substantial sprung load is increased due to centrifugal force acting by turning a corner having a predetermined curvature at a certain vehicle speed.

Then, each of the brake pressures Pfi and Pr
It is determined whether or not at least one of i is lower than the lower limit pressures Pfm and Prm when the braking operation is being performed (step S5). If it is smaller, it is determined that the braking operation is not performed, and the F suspension stroke variation is further performed. It is determined whether or not the absolute value of the amount Sfi is larger than the threshold value Sfm for whether or not the second control for correcting the reference damping force is performed (step S6).

When the stroke variation amount Sfi is larger than the threshold value Sfm, the expansion / contraction speed Vf of the front side shock absorber is further calculated as if it has climbed over a predetermined convex portion or has fallen into a concave portion, and the above-mentioned reference The damping force is corrected to an appropriate corrected damping force Ff 'corresponding to the expansion / contraction speed Vf (steps S7 and S8), and a control signal corresponding to the corrected damping force is output to the front solenoid valve 28a.

Simultaneously with the calculation of the expansion / contraction speed of the F suspension, the road surface condition is predicted based on the stroke variation Sfi, and the reference damping force of the rear suspension is corrected to an appropriate corrected damping force Fr 'based on the prediction. (Step S9,
S10), a control signal is output to the rear solenoid valve 28b. Note that the main CPU 24 performs the calculation and the sub-CPU performs the calculation, so that the simultaneous calculation can be performed.

In step S5, if the brake pressure is larger than the reference value, it is determined that the braking operation is being performed, and the current deceleration αn obtained from the detected vehicle speed is decremented by a threshold value as to whether or not it is considered that there is no deceleration. It is compared with the speed αj (step S11), and if it is less than the threshold value, step S11.
4, the deceleration αi at that time is exceeded when the threshold value is exceeded.
Is calculated from the brake pressure (step S1)
2). The deceleration αi is read from the built-in brake pressure-deceleration map (see FIG. 3B). In this map, characteristic lines a and b represent decelerations when only the front brake and only the rear brake are actuated, and when both are actuated, they are the sum of both.

Next, the attitude change mode is set according to the calculated deceleration αi, and the reference damping force is corrected to the corrected damping forces Ff 'and Fr' according to the attitude change mode (steps S12-14). ), A control signal corresponding to the damping force is output to each of the solenoid valves 28a and 28b. This corrected damping force is supplied until the current deceleration αn becomes smaller than the threshold deceleration αj (step S
15).

As described above, in this embodiment, the shock absorbers 13 and 1 are
Since the damping force of 0 is set to the reference value damping force according to the vehicle speed, an appropriate damping force can be obtained even during cornering with a simple structure, and the reference damping force can be adjusted according to the road surface condition and braking operation. Since it is corrected by the above, it is possible to cope with changes in the vehicle posture due to thrusting up from the road surface or braking.

[0031]

As described above, according to the damping force control device for a motorcycle suspension according to the present invention, a standard in which the centrifugal force is applied according to the vehicle speed during normal straight running and cornering. Set the damping force,
When riding on a convex part on the road or falling into a concave part, or when the vehicle posture changes due to braking,
Since the correction damping force is corrected according to the expansion / contraction speed or posture change mode of the shock absorber, there is an effect that proper damping force characteristics can be obtained with a simple structure.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing a configuration of the present invention.

FIG. 2 is a block diagram of a control device for a motorcycle suspension according to an embodiment of the present invention.

FIG. 3 is a flow chart for explaining the operation of the above embodiment.

FIG. 4 is a side view of a motorcycle equipped with the device of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 motorcycle 13 and 10 front and rear shock absorbers 14 stroke position detection means 16 vehicle speed detection means 17, 18 brake pressure detection means 31 reference damping force setting means 32 damping force correction means 33 expansion and contraction speed calculation means 34 first damping force correction Means 35 Road surface condition prediction means 36 Second damping force correction means 38 Deceleration calculation means 39 Attitude change mode setting means 40 Third damping force correction means

Claims (3)

[Claims] 1. A vehicle speed detecting means, a reference damping force setting means for setting a damping force of the front and rear shock absorbers to a value corresponding to a case of turning at a corner of a predetermined curvature at a detected vehicle speed, road surface conditions or A damping force control device for a suspension for a motorcycle, comprising: damping force correcting means for correcting the reference damping force according to a vehicle attitude. 2. The damping force correction means according to claim 1, wherein the absolute value of the difference between the stroke position detection means for detecting the stroke position of the front shock absorber and the detected stroke position and the average stroke position is not less than a reference value. At this time, the expansion / contraction speed calculating means for obtaining the expansion / contraction speed of the front shock absorber, the first damping force correction means for correcting the reference damping force of the front shock absorber to the corrected damping force according to the expansion / contraction speed, the detected stroke position and the average stroke A second damping force correction means for predicting the road surface condition when the absolute value of the difference from the position is equal to or greater than the reference value, and correcting the reference damping force of the rear shock absorber to the corrected damping force according to the prediction. A damping force control device for a motorcycle suspension. 3. The braking force detecting means according to claim 1, wherein the damping force correcting means detects the brake pressure of the front and rear wheels, and the deceleration from the detected brake pressure when the detected brake pressure is equal to or higher than a reference value. A deceleration calculating means for obtaining, a posture change mode calculating means for obtaining a change mode of the vehicle posture from the obtained deceleration, and a third damping force for correcting the reference damping force to a damping force according to the obtained posture changing mode. A damping force control device for a motorcycle suspension, comprising: a correction means.