JP3251335B2 - Damping force control system for motorcycle suspension - Google Patents

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 in a method for setting a damping force so that a proper damping force can be obtained according to a running state by a simple structure. .

[0002]

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

[0003]

However, the above-mentioned conventional control device is for a four-wheeled vehicle, and is used as it is as a damping force control device for a motorcycle on the premise that the vehicle body is inclined when turning a corner. It is not possible. Further, the above-mentioned conventional apparatus has a problem that the structure is complicated and the cost is high, and it is not suitable for a relatively low-cost vehicle such as a motorcycle.

The present invention has been made in view of the above-mentioned conventional circumstances, and has as its object to provide a damping force control device for a motorcycle suspension that can secure an appropriate damping force with a simple structure.

[0005]

According to the first aspect of the present invention, the centrifugal force acts by turning the vehicle speed detecting means and the damping force of the front and rear shock absorbers at a detected vehicle speed at a corner having a predetermined curvature. Reference damping force setting means for setting the damping force to be optimal when the substantial sprung load is increased, stroke position detecting means for detecting the stroke position of the front shock absorber, detected stroke position and average stroke position Expansion / contraction speed calculating means for calculating the expansion / contraction speed of the front shock absorber when the absolute value of the difference between the first shock absorber and the first shock absorber is equal to or greater than a reference value, Force correction means, predicting the road surface condition 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 damping force control device for a motorcycle suspension, comprising: a second damping force correction means for correcting the reference damping force of the rear shock absorber to a corrected damping force according to the prediction.

According to a second aspect of the present invention, the damping force of the vehicle speed detecting means and the front and rear shock absorbers is turned by a centrifugal force by turning a corner having a predetermined curvature at the detected vehicle speed. Reference damping force setting means for setting an optimum damping force when the upper load is increased; brake pressure detecting means for detecting front and rear wheel brake pressures respectively; and detecting when the detected brake pressure is higher than a reference value. A deceleration calculating means for obtaining a deceleration from the brake pressure; an attitude change mode calculating means for obtaining a vehicle attitude change mode from the obtained deceleration; and a damping force corresponding to the determined attitude change mode. A damping force control device for a motorcycle suspension, comprising: a third damping force correcting means for correcting the damping force.

[0007]

[0008]

According to the motorcycle damping force control apparatus according to the first and second aspects of the present invention, the damping force of the shock absorber is detected during a normal running on a relatively flat road surface in a straight running or a turning running. It is set to a value (reference damping force) that takes into account the substantial increase in the sprung load at the time of cornering at the set vehicle speed.

According to the first aspect of the present invention, the reference damping force is corrected by the following procedure. For example, in the case of overcoming a convex part 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 a reference value, the expansion / contraction speed of the front shock absorber is calculated, and The reference damping force is corrected to a corrected damping force according to the expansion / contraction speed. 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 second aspect of the present invention, the reference damping force is corrected by the following procedure. When the brake pressure is equal to or higher than the reference value, a deceleration is calculated from the brake pressure, a change mode of the vehicle posture is set based on the deceleration, and the reference damping force is corrected to a correction damping force corresponding to the posture change mode. You.

As described above, according to the present invention, during normal straight running and turning running, the reference damping force is set according to the vehicle speed and taking into account the centrifugal force at the time of turning, so that the vehicle can ride on a convex portion on the road, If the vehicle falls into a concave part or the vehicle changes its position due to braking, the damping force is corrected to the correction 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 diagrams for explaining a motorcycle damping force control device according to an embodiment of the present invention. FIG. 2 is a block diagram, FIG. 3 is a flowchart, and FIG. It is a side view.

In FIG. 4, reference numeral 1 denotes a motorcycle on which the apparatus of the embodiment is mounted. The motorcycle 1 includes a front fork (front suspension) 3 which is supported by a head pipe 2a of a body frame 2 so as to be steerable left and right. To support the front wheel 4,
A rear arm 6 pivotally supported by a rear arm bracket 2b of the vehicle body frame 2 pivotally supports the rear wheel 6, and supports and suspends an engine 7 below a central portion of the vehicle body frame 2 while fueling upward. It has a structure in which a tank 8 is mounted.

The rear arm 6 and the lower end of the rear arm bracket 2b are connected by a link mechanism 11. Between the link mechanism 11 and the upper part of the rear arm bracket 2b, a rear shock absorber 10 including a shock absorbing spring and a damping damper is provided. A rear suspension 12 is constituted by the rear arm 6, the link mechanism 11, and the rear shock absorber 10.

The front fork 3 is formed by connecting upper portions of a pair of left and right telescopic fork bodies 3a, 3a to each other with a pair of upper and lower brackets 3b, 3b. A front shock absorber 13 including a damper is incorporated.

An F-suspension sensor 14 for detecting a stroke position of the front fork 3 is mounted above the front fork 3.
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.

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

The link mechanism 11 of the rear suspension 12 is provided with an R-suspension 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 for detecting the vertical acceleration of a sprung portion at the rear of the vehicle body is mounted on the seat rail 2c of the vehicle body frame 2.

At a position below the seat of the vehicle body frame 2, a control unit 21 constituting a main part of the apparatus of this embodiment is disposed. 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
5 is provided with operation units 24a and 25a that perform the same operation in duplicate. The calculation units 24a and 25a are provided with the above-described reference damping force setting means 31, expansion / contraction speed calculation means 33, first damping force correction means 34, road surface condition prediction means 35, second damping force correction means 36, deceleration. It has various functions such as a calculating means 38, a posture change mode calculating means 39, and a third damping force correcting means 40.

The main CPU 24 is provided with the sub C
Judgment unit 2 for judging failure by operation comparison with PU25
4c and a control signal corresponding to the calculation result from the determination unit 24c and the calculation unit 24a.
7, front and rear suspension solenoid valves 28
a, 28b, and a control unit 24b for outputting to the abnormality warning device 28c.

Next, the operation of this embodiment will be described with reference to the flowchart shown in FIG. When the main switch is turned on, the program starts, and the vehicle speed 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 determined whether or not the vehicle speed Vi is within a range from a predetermined low speed Vmin to a lower limit speed Vo (step S2). If the vehicle speed Vi is outside the above range, it is immediately determined. Are elapsed, F and R average stroke positions Sfa and Sra are calculated. These values are values obtained by averaging the stroke variation amounts Sfi and Sri. (Step S3).

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

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

The above-mentioned brake pressures Pfi, Pr
It is determined whether at least one of i is smaller than the lower limit pressures Pfm and Prm when the braking operation is being performed (step S5). When it is smaller, it is determined that the braking operation is not being performed, and the F suspension stroke variation is further determined. It is determined whether the absolute value of the amount Sfi is greater than a threshold value Sfm for determining whether to perform the second control for correcting the reference damping force (step S6).

If the stroke variation Sfi is greater than the threshold value Sfm, the expansion / contraction speed Vf of the front shock absorber is further calculated as whether the vehicle has climbed over a predetermined convex portion or dropped into a concave portion, 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, a 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 correction damping force Fr 'based on the prediction. (Step S9,
S10), a control signal is output to the rear solenoid valve 28b. Note that the calculation of (1) is performed by the main CPU 24, and the calculation of (2) is performed by the sub CPU, whereby simultaneous calculation is possible.

If it is determined in step S5 that the brake pressure is larger than the reference value, it is determined that the braking operation is being performed, and the threshold value for determining whether or not the current deceleration .alpha. The speed is compared with the speed αj (step S11).
4, if it is equal to or greater than the threshold value, the deceleration αi at that time
Is calculated from the brake pressure (step S1).
2). The deceleration αi is read from a built-in brake pressure-deceleration map (see FIG. 3B). In this map, the characteristic lines a and b show the deceleration when only the front brake and the rear brake are actuated, respectively, and when both act, the sum of the two is obtained.

Next, a posture change mode corresponding to the calculated deceleration αi is set, and the reference damping force is corrected to corrected damping forces Ff ′ and Fr ′ corresponding to the posture change mode (steps S12 to S14). ), 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 the present embodiment, the shock absorbers 13, 1
Since the zero damping force is set to a reference value damping force according to the vehicle speed, an appropriate damping force can be obtained even when cornering with a simple structure, and the reference damping force can be adjusted according to the road surface condition and the braking operation. , It is possible to cope with a change in the vehicle attitude due to pushing up from the road surface or braking.

[0031]

As described above, according to the motorcycle damping force control apparatus according to the present invention, during normal straight running and cornering, the reference according to the vehicle speed and the centrifugal force at the time of turning is taken into account. Set the damping force,
If you get on a convex part on the road, fall into a concave part, or change the vehicle posture due to braking,
Since the correction is made to the correction damping force according to the expansion / contraction speed or the posture change mode of the shock absorber, there is an effect that an appropriate damping force characteristic can be obtained with a simple structure.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims 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 flowchart for explaining the operation of the embodiment.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motorcycle 13,10 Front and rear shock absorbers 14 Stroke position detecting means 16 Vehicle speed detecting means 17,18 Brake pressure detecting means 31 Reference damping force setting means 32 Damping force correcting means 33 Expansion / contraction speed calculating means 34 First damping force correction Means 35 Road surface condition predicting means 36 Second damping force correcting means 38 Deceleration calculating means 39 Attitude change mode setting means 40 Third damping force correcting means

Continuation of the front page (56) References JP-A-55-11924 (JP, A) JP-A-1-212688 (JP, A) JP-A-4-8614 (JP, A) JP-A-60-193710 (JP) JP-A-61-1519 (JP, A) JP-A-62-39386 (JP, A) JP-A-1-229790 (JP, A) JP-A-3-10979 (JP, A) 58-152406 (JP, U) Hira 2-59092 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B62K 25/04 B60G 17/015

Claims (2)

(57) [Claims] The vehicle speed detecting means and the damping force of the front and rear shock absorbers are turned at a detected vehicle speed at a corner having a predetermined curvature.
As a result, centrifugal force acts and the actual sprung load increases.
A reference damping force setting means for setting an optimum damping force in a state where the shock absorber has been set, and a stroboscope for detecting a stroke position of the front shock absorber.
Stroke position detecting means, the detected stroke position and the average stroke.
Front shock absorber when the absolute value of the difference from the
Expansion / contraction speed calculating means for determining the expansion / contraction speed of the
Compensation of the reference damping force of the
First damping force correcting means for correcting the detected stroke position,
When the absolute value of the difference from the average stroke position is
Predict the surface condition and set the reference damping force of the rear shock absorber
A damping force control device for a motorcycle suspension, comprising: a second damping force correction unit that corrects the correction damping force according to the measurement . 2. A vehicle speed detecting means and front and rear shock absorbers.
Turns at the detected vehicle speed at a corner with a predetermined curvature.
As a result, centrifugal force acts and the actual sprung load increases.
Reference damping force setting to set the optimal damping force when
Means and brakes for respectively detecting front and rear wheel brake pressures
Key pressure detection means, and if the detected brake pressure is
Deceleration calculator that calculates deceleration from the detected brake pressure
The vehicle attitude change mode is determined from the step and the determined deceleration.
Attitude change mode calculation means and the above-mentioned reference damping force
Third reduction to correct the damping force according to the changed posture change mode
Damping force control apparatus for a motorcycle suspension, characterized in that a衰力correction means.