JPS60219183A - Steering gear for motorcycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a steering device for a motorcycle.

[Prior art]

As the motorcycle number, t, and vehicle speed increase, irregular disturbances transmitted from the road surface to the handlebars via the front wheels become larger, causing abnormal vibrations called shimmy. For this reason, the steering stability tends to deteriorate as the speed increases.

In order to prevent such deterioration of steering stability, as described in Japanese Utility Model Publication No. 43-19056, a piston is fitted into a cylinder filled with oil, and two oil chambers are separated by the piston. Some steering shock absorbers are interposed between the handle member and the vehicle body frame, and the steering shock absorber is configured to communicate with the handle member through an orifice. By installing this steering shock absorber, abnormal vibrations such as shimmy can be absorbed by hydraulic damping.

However, the above-mentioned steering shock absorber has the disadvantage that it provides a large amount of resistance when the vehicle attempts to turn the steering wheel significantly during low-speed driving, making the steering operation difficult.

[Purpose of the invention]

The purpose of the present invention is to automatically change the hydraulic shock absorbing force of the steering shock absorber according to the driving condition, even in a two-axle automatic vehicle equipped with a steering shock absorber, so as to maintain good steering stability at all times. An object of the present invention is to provide a steering device for a motorcycle that can be maintained.

[Structure of the invention]

To achieve the above object, the present invention provides a steering shock absorber constructed by fitting a piston into a cylinder, dividing the inside of the cylinder into two oil chambers, and communicating these two oil chambers through an orifice. in a motorcycle connected between a handle member that rotates together with the handle and a vehicle body frame, the degree of aperture of the orifice of the steering damper can be adjusted, and the detection detects a steering performance control factor of the handle. The present invention is characterized in that a detector is provided, and the degree of aperture of the orifice is controlled by a detection signal from the detector.

In the present invention, the steering performance control factors are factors that have a correlation with the steering performance of the steering wheel, such as vehicle speed, acceleration/deceleration, acceleration/deceleration frequency, steering angle, steering angle acceleration, average steering angle, and the steering performance of the vehicle body. Refers to posture (degree of forward or backward leaning), etc.

The speed can be detected from a speedometer, and can also be detected from the accelerator opening degree and engine rotational speed as an alternative vehicle speed value. Acceleration/deceleration can be detected from the brake oil pressure, but it can also be detected by processing the vehicle speed, accelerator opening, etc. with a differentiator. This is suitable for accelerator opening and brake oil pressure because it allows for predictive control. The steering angle can be detected from the relative position between the steering axis and the head pipe of the vehicle body frame. The rudder angle acceleration can be obtained by processing the rudder angle using a two-machine divider. Further, the average steering angle can be obtained by averaging the integrated steering angles. The attitude of the vehicle body can be determined using a level device or the like.

As mentioned above, vehicle speed has a correlation with the shimmy (abnormal vibration) phenomenon of the steering system, and the higher the vehicle speed, the more likely shimmy will occur. For example, generally about 50-80km/h
At a vehicle speed of approximately 6 to 8 Hz, vibrations around the steering axis (w
obb18), and the speed is about 110km/h.
When the vehicle speed is higher than that, a meandering phenomenon of approximately 2 to 3 Hz occurs
eave ) will now be generated.

Therefore, this vehicle speed is detected as a steering control factor,
Shimmy can be suppressed by adjusting the degree of aperture of the adjustable orifice of the steering damper based on the detection signal so as to provide a hydraulic damping force that absorbs abnormal vibrations.

When the vehicle speed reaches ultra-high speeds of 200 km/h or more, the self-lining torque and the gyroscopic effect of the wheels increase, which improves straight-line performance, but tends to increase the steering force. At such extremely high speeds, the degree of aperture of the orifice may be controlled so that the hydraulic damping force of the steering damper becomes slightly smaller than at the high speeds.

Furthermore, when riding a motorcycle in sports or on curved roads, it is better to use less steering force so that the rider can operate the steering wheel more quickly. Since this type of driving is characterized by frequent acceleration and deceleration, the frequency of acceleration and deceleration is detected as a steering performance control factor, and when the frequency of acceleration and deceleration exceeds a certain reference amount, the degree of orifice aperture is determined. It is better to reduce the hydraulic damping force of the steering damper by one step to reduce the steering force.

Also, when looking at the state of steering wheel operation on motorcycles, when turning the steering wheel significantly, the vehicle speed is slowed down.
On the other hand, when driving at high speeds, you don't have to turn the steering wheel too much. For this reason, a large steering angle appears at low speeds, but only a small steering angle tends to appear at high speeds. therefore,
By detecting the appearance of this steering angle as a steering performance control factor and reducing the degree of aperture of the orifice and reducing the hydraulic damping force of the steering damper when the steering angle is large, the steering wheel can be made lighter. Furthermore, when small steering angles occur frequently, by increasing the orifice aperture and increasing the hydraulic damping force of the steering damper, the steering wheel can be made heavier, improving steering stability at high speeds.

Also, when the vehicle speed is accelerated or decelerated, the vehicle body pitches (
(swinging back and forth) and changing steering geometry such as caster angle and trail, resulting in poor steering stability. for example,
When the vehicle body leans forward due to deceleration, the caster angle and trail become smaller, resulting in a decrease in self-lining torque and poor straight-line performance. In addition, when tilting backwards when two people are riding or when starting suddenly, the front wheels are amplified, which is the opposite of the above, and although the steering system's geometry strengthens the ability to drive straight, the distributed load on the front wheels decreases. This actually weakens the straightness of the vehicle.

If sudden steering is performed under these conditions, the vehicle will become unstable. Therefore, in such a case, if the acceleration/deceleration or the attitude of the vehicle body is detected as a steering performance control factor and the orifice aperture is adjusted accordingly, the hydraulic damping force of the steering damper will increase and the steering stability will be improved. do.

Furthermore, when driving on an uneven road surface, the driving resistance is applied as a reaction force to the steering wheel via the front wheels. This reaction force becomes a large force, usually called kickback, when the vehicle is running at high speed or when there is a large disturbance, making the steering stability unstable. Generally, the limit to which a human can physically suppress a kick bank is 4 to 5 Hz, and it is considered difficult to suppress a kink hack at a higher frequency than this. Such a high frequency kick bank has a correlation with the steering angle acceleration R. Therefore, this steering angular acceleration is detected as a steering performance control factor, and when the steering angle acceleration is a high-frequency steering back that exceeds the limit that humans can suppress, the orifice aperture is set to Gotenba, and the hydraulic damping force of the steering shock absorber is reduced. Just make it bigger.

Generally, it is difficult to achieve both straight-line performance and steerability in a motorcycle. That is, if the geometry is changed to increase the self-lining torque in order to improve straight-line performance, the steering force when turning the steering wheel increases.

Therefore, in addition to using a geometry that does not increase the self-lining torque too much, the above-mentioned steering angle is used as a steering performance control factor, and the detected current steering angle R is compared with the average steering angle R to determine whether l R - Rl is equal to or greater than the reference amount. In this case, if the degree of restriction of the orifice is adjusted to the maximum and the hydraulic damping force of the steering shock absorber is increased, both straightness and steering performance can be achieved.

It is preferable that each of the above-mentioned steering performance control factors is mainly based on vehicle speed and/or steering angle, but by combining these with other steering performance control factors, comprehensive steering stability that can be applied to all driving conditions can be achieved. You will be able to improve your sexuality.

[Embodiments of the invention]

Hereinafter, the present invention will be explained with reference to specific embodiments shown in the drawings.

In the figure, 1 is a body frame of a motorcycle, and a steering shaft 2 is rotatably fitted into a hend pipe 1a at the front of the body frame 1, and the steering shaft 2 has an upper end and a lower end. An upper bracket 3 and a lower bracket 4 are each fixed.

A handle 7 is fixed to the upper part of the upper bracket 3. Furthermore, front forks 5.degree. 5 are fixed to both ends of the upper bracket 3 and lower bracket 4, respectively, and a front wheel 6 is pivotally supported at the lower ends thereof. Above and below the upper and lower brackets 3.
4 and the left and right front forks 5, 5 are members that rotate together around the steering shaft 2 by operating the handle 7 left and right, and constitute the handle member referred to in the present invention. . Rotates integrally with the handle 7 above.

A steering shock absorber 8 is connected between the lower bracket 4 and the vehicle body frame 1.

As shown in FIGS. 3 and 4, this steering shock absorber 8 is composed of a cylinder 9 completely filled with hydraulic oil and a piston 10 that fits into this cylinder 9. A piston rod 11 to which the piston 10 is fixed is , penetrating the inside of the cylinder 9 from front to back. One end of the piston rod II protruding from the cylinder 9 is rotatably connected to the vehicle body frame 1 side via a connecting portion 11a, and the cylinder 9 is connected via a connecting portion 9a provided on its outer periphery. It is rotatably connected to the lower bracket 4 side.

Inside the cylinder 9, two oil chambers A are formed by the piston 10.
, H, these two oil chambers A and B communicate with each other via a communication passage 12 provided within the inner wall of the cylinder 9. A valve body 14 is provided in the middle of the communication path 12, and this valve body 14 is rotationally driven by a pulse motor 15. The valve body 14 is provided with a large number of throttle orifices 13a, 13b, 13c, and 13d having different degrees of restriction, one of which selectively communicates with the communication path 12. Further, the pulse motor 15 is connected to the drive circuit 2
The rotation is controlled by a control signal output from 2.

Note that the valve body 14 is not limited to a cylindrical configuration as shown in FIGS. 3 and 4, but may also be a plate-shaped valve body 14 as shown in FIG. 5.6.
′ may be used. Alternatively, it may be constructed of a needle valve facing one orifice, and the degree of aperture may be continuously changed by changing the distance between the needle valve and the orifice.

When steering the handlebar 7 or when the front wheels 6 receive a reaction force from the road surface, the lower bracket 4
It also rotates left and right. At this time, the above-mentioned steering shock absorber 8 expands and contracts as the piston 10 slides within the cylinder 9. Therefore, the hydraulic oil in the oil chambers A and B moves through the communication passage 12 and generates a hydraulic damping force when passing through the throttle orifice of the valve body 14.

The above-mentioned hydraulic damping force becomes the smallest when the throttle orifice 13a with the smallest degree of restriction (largest degree of opening) communicates, and the hydraulic damping force is the smallest when the degree of restriction is the largest (the degree of opening is the smallest).
It becomes the largest when the throttle orifice 13d communicates.

Such aperture control can be performed by driving the pulse monitor 15 using a control signal from the drive circuit 22.

In the above motorcycle, the speedometer 16 is provided with a vehicle speed detector 16a, and the head pipe 1a is provided with a steering angle detector 17, as detectors for detecting steering performance control factors of the control system.

Further, an accelerator opening detector 18a is provided on the accelerator grip portion 18 of the handle 7, an oil pressure detector 19a is provided on the brake mask cylinder 19 for detecting oil pressure as a braking signal, and the vehicle body frame 1 is provided with an A posture detector 2° is provided to detect changes in the tilt of the body.

Detection signals such as vehicle speed, rudder angle, acceleration/deceleration, attitude, etc. detected by each of the above-mentioned detectors, as well as signals such as rudder angle acceleration, average rudder angle, etc. derived from the rudder angle are processed in the arithmetic processor 21, for example, by the seventh
The process is performed according to the flowchart shown in the figure, and the pulse motor 15 is driven via the drive circuit 22 to adjust the degree of restriction of the restriction orifice of the valve body 14 in the steering damper s.

As shown in the flowchart of FIG. 7, the above-mentioned detection signals control the degree of restriction of the restriction orifice of the valve body 14 according to processes such as phase (2) and phase (2), respectively. Control is mainly carried out in Phase I, and Phase (2) can be omitted if necessary.

As shown in phase (2), when the motorcycle is stopped or starts running, the orifice aperture is set to be small as in step 30. By detecting the vehicle speed in step 31, the orifice aperture is controlled to be small when the vehicle speed is low (step 32), large when the vehicle is high (step 34), and medium when the vehicle is extremely high (step 33). - Through such control, the hydraulic damping force of the steering shock absorber 8 changes as described above, preventing abnormal vibrations at high speeds or ultra-high speeds, and making it possible to operate the steering wheel with a small steering force at low speeds. .

In phase 2, assuming the state of phase I described above, if cruise control is in operation as determined in step 35, the orifice aperture is corrected to Gotemba in step 36, strengthening straightness during cruising and stabilizing the running. Improve your sexuality. When the cruise control operation is not being performed, the acceleration/deceleration is detected and the acceleration/deceleration frequency is calculated in steps 37 and 38. If the frequency is equal to or higher than the reference amount, the orifice aperture is reduced by one step in step 39 to reduce the steering force when driving on a curved road or during sports driving, thereby improving steering stability.

Further, when the acceleration/deceleration frequency is less than the reference amount, the steering angle R is detected in step 40, and the steering angle R is detected in steps 41 and 4.
In step 2, the steering angle acceleration R and the average steering angle R are calculated, and in step 43, the vehicle body attitude (presence of forward or backward tilt) is detected. If the steering angular acceleration is equal to or greater than the reference amount, the orifice aperture is increased by one step in step 36 to prevent the squeak caused by road surface disturbance. If the average steering angle or IR-101 is greater than the reference value, the orifice aperture is increased by one step in step 36 to improve the steering performance. Also,
When the vehicle body posture is about 1 forward or backward tilted, the orifice aperture is corrected by one step in step 36 to improve steering stability.

Thereafter, by repeating Phases I and II, the motorcycle can always maintain good handling stability depending on the driving condition.

〔Effect of the invention〕

As described above, the present invention provides a steering shock absorber in which a piston is fitted into a cylinder, the inside of the cylinder is divided into two oil chambers, and these two oil chambers are communicated through an orifice. In a motorcycle connected between a handle member that rotates together with the handle and a vehicle body frame, a detector is provided that makes it possible to adjust the degree of aperture of the orifice of the steering shock absorber and detects a steering performance control factor of the handle. established,
Since the configuration is such that the degree of aperture of the orifice is controlled based on the detection signal of this detector, the hydraulic damping force of the steering shock absorber is automatically controlled according to changes in the running condition of the motorcycle, and good steering stability is always achieved. can be maintained.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the main parts of a motorcycle equipped with a steering device according to an embodiment of the present invention together with a control circuit, and Fig. 2 is a partially cutaway plan view showing the main parts of the motorcycle. , 3rd
The figure is a longitudinal cross-sectional view of the steering shock absorber installed in the same motorcycle.
The figure is a view taken along the TV-IV arrow in FIG. 3, FIG. Fig. 7 is a diagram showing an example of a control flowchart. 1... Vehicle body frame, 4... Lower plug throat (〕λ
8... Steering shock absorber, 9... Cylinder, 10... Piston, 12... Communication path, 14,
14'--valve body, 13a, 13b, 13c, 13
d... Squeezing orifice, 15... Nonoru smoke,
16a... Vehicle speed detector, 17... Rudder angle detector,
18a...Accelerator opening degree detector, 19a...Oil pressure detector, 20...Attitude detector, 21...Arithmetic processing unit, 22...Drive circuit, A, B...Oil chamber. Agent: Patent Attorney Shin Ogawa − Patent Attorney Ken Noguchi Teru Patent Attorney Kazuhiko Saishita

Claims (1)

[Claims] A steering shock absorber is constructed by fitting a piston into a cylinder to divide the inside of the cylinder into two oil chambers, and communicating these two oil chambers via an orifice. In the motorcycle connected to the frame, the degree of aperture of the orifice of the steering @impact device is adjustable, and a detector is provided to detect a steering control factor of the handlebar, and a detection signal of the detector is provided. A steering device for a motorcycle configured to control the degree of aperture of the orifice.