JPH05201378A - Steering damper - Google Patents

Abstract

PURPOSE:To rapidly and accurately cope with the occurrence of disturbance by individually regulating initial set values on the side where a damping force is high and the side where the damping force is low through regulation of the respective throttles of a first orifice arranged on a piston and a second orifice in a bypass passage and moreover rapidly switching the throttle to the side, where the damping force is high, by means of an on-off valve. CONSTITUTION:First and second orifices 20 and 29 the throttles of which are individually regulatable through first and second adjusters 16 and 30 are located on a piston 17 and in a bypass passage 24, respectively. A valve 40 for opening and closing the bypass passage 24 is controlled by a control device 47 such that it is closed when a load by disturbance exceeds a threshold level and opened at other time than the above. Since, in the second orifice 29, when the valve 40 is opened, a damping force is generated, regulation of the second orifice 29 is important to the initial set value of a damping force on the normal state side. When the valve 40 is closed, fluid flows only through the first orifice 20 and a damping force is extremely increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering damper used in a steering device for a motorcycle, the damping force being adjustable.

[0002]

2. Description of the Related Art Such a steering damper is well known, and an example thereof is disclosed in JP-A-60-219183. In this system, a piston is fitted in a cylinder to divide the inside of the cylinder into two chambers, a variable orifice is provided in a communication passage between these two chambers, and the variable orifice is changed based on a vehicle speed or the like to allow traveling. The damping force is automatically controlled according to changes in the state.

[0003]

By the way, it is desired that the damping force of such a steering damper can be adjusted to an appropriate initial setting value in accordance with the course and the skill of the occupant.
Moreover, it is also desirable that both the high damping side and the low damping side can be adjusted individually during this initialization. However, the above-mentioned conventional example merely allows automatic adjustment, and does not satisfy such a requirement. Therefore, the present invention aims at satisfying the various requirements.

[0004]

In order to solve the above-mentioned problems, a steering damper according to the present invention makes a throttle provided in a piston variable as an orifice communicating between two chambers in a cylinder divided by the piston. A first orifice and a second orifice, which is provided in a bypass passage communicating between the two chambers and has a variable throttle, are provided.
An on-off valve is provided in the bypass passage.

[0005]

When the throttle of the first orifice provided in the piston is adjusted, the initial setting value of the damping force on the side where the damping force is large can be adjusted as desired. Further, by adjusting the throttle of the second orifice provided in the bypass passage, it becomes possible to adjust the initial setting value of the damping force on the side where the damping force is small. Moreover, the throttles of the first orifice and the second orifice can be individually adjusted. Furthermore, when the on-off valve is closed, the side with the larger damping force is quickly switched.

[0006]

EXAMPLE One example is shown in FIGS. FIG. 2 shows the left side surface of the front part of the vehicle body of the motorcycle in which the example product is used. The upper end portion of the front fork 2 supporting the front wheel 1 is provided with a bottom bridge 3 and a top bridge 4,
It is connected to a steering shaft 6 which is rotatably supported by the head pipe 5. The steering shaft 6 is rotated by a handle 7.

A head pipe 5 is provided at a front end portion of a main frame 8 which constitutes a part of a vehicle body frame and extends in the front-rear direction, and a cylinder of a steering damper 10 is provided on a front side surface of the main frame 8 via a bracket 9. 11 is fixed.

The tip of the piston rod 12 of the steering damper 10 is connected to a bracket 14 attached to the front fork 2 via a joint 13, and a load sensor 15 is provided in the middle of the piston rod 12.
Is provided.

FIG. 1 shows a detailed structure of the steering damper 10. A piston 17 is provided at the end of the piston rod 12 inside the cylinder 11, and the inside of the cylinder 11 is divided into first and second chambers 18 and 19 by this piston 17. The first and second chambers 18 and 19 are communicated with each other by a first orifice 20 formed by bending in a crank shape in the end portion of the piston 17 and the piston rod 12 inside thereof.

A small-diameter projection 21 formed at the inner end of the cylinder 11 of the first adjuster 16 faces the bent portion of the first orifice 20 located at the axial center of the piston rod 12 so as to be movable back and forth. By moving the small-diameter protrusion 21 back and forth, the flow rate of the fluid in the first orifice 20 can be adjusted.

A male screw portion 16a is provided on the outer circumference of the first orifice 20 in the vicinity of the small-diameter protrusion portion 21, and a female screw portion 1 formed on the inner peripheral surface of the piston 17 correspondingly.
7a is engaged. When the knob 16b formed at the rear end of the first adjuster 16 is rotated, the small diameter protrusion 21
Can move forward and backward to change the damping force, so that the first adjuster 16 can manually adjust the initial value of the damping force by the first orifice 20.

A click 23 is provided in the portion of the first adjuster 16 where the rear side of the piston 17 overlaps. The click 23 protrudes in the radial direction of the first adjuster 16 and can engage with a concave portion provided at an appropriate interval on the inner peripheral surface of the piston 17 side such as a ball or a pin, and urges this in the protruding direction. It consists of a spring. The provision of the click 23 provides a feeling of moderation when the first adjuster 16 is rotated to adjust the aperture of the first orifice 20.

A side portion of the cylinder 11 partially projects laterally to form a bypass passage 24. Bypass passage 2
Reference numeral 4 includes an intermediate portion 25 that is substantially parallel to the piston rod 12, and a first chamber side passage 26 and a second chamber side passage 27 that are bent at right angles from both ends thereof and communicate with the first chamber 18 or the second chamber 19. ..

A second portion is provided in the bent portion 28 on the second chamber side passage 27 side.
The orifice 29 is provided, and the small-diameter protrusion 31 formed at the tip of the second adjuster 30 advances and retracts, whereby the throttle amount can be adjusted, and as a result, the bypass passage 24 by the second orifice 29 is adjusted. The initial damping force on the side is manually adjustable.

The second adjuster 30 is the first adjuster 16
It has almost the same structure as. In the figure, reference numeral 32 is a male screw portion formed on the outer circumference of the second adjuster 30, 33a is a thick corner portion of the cylinder 11, 34 is a female screw portion, 35 is a click, and 36 is a knob.

On the other hand, a valve 40 for opening and closing the bypass passage 24 is provided at the bent portion of the intermediate portion 25 which is connected to the first chamber side passage 26. The valve 40 is a substantially columnar member having an axis coincident with the axis of the intermediate portion 25, and is rotatably supported by the thick portion 33b of the cylinder 11.

The valve 40 is formed with a passage 41 that is bent at a right angle, one opening end 42 of which opens to the axial center of the valve 40 and always communicates with the intermediate portion 25, and the other opening end 43 of which is the outer periphery of the valve 40. It opens to the surface. The other open end 43
Can take an open position in which it communicates with the first chamber side passage 26 and a closed position in which it does not communicate by the rotation of the valve 40. However, the structure of the valve 40 is not limited to this embodiment, and various other structures can be adopted.

When the other open end 43 is in the open position, the bypass passage 24 is in communication, so the valve 40 is open. When the other open end 43 is in the closed position, the bypass passage 24 is inactive, so the valve 40 is It will be closed.

The valve 40 is connected to an output shaft 45 of a motor 44. The motor 44 is supported in a motor case 46 formed integrally with the bypass housing 24, and is drive-controlled by the control device 47 to open and close the valve 40. However, the motor 44 can not only open and close the valve 40, but can also change its opening continuously.

The control device 47 is composed of a microcomputer and outputs a drive control signal for the motor 44 based on the detection signal from the load sensor 15.

The load sensor 15 has screw holes formed in the boss portion 15a, and screw portions 12a, 13a formed in the front end portion of the piston rod 12 and the rear end portion of the joint 13 are formed in the boss portion 15a.
Are connected to each other between the end portions of the piston rod 12 and the joint 13, and when a load is applied in the pushing and pulling direction from the joint 13 side, an electric signal corresponding to the load amount is input to the control device 47. It is supposed to do.

First, the adjustment of the initial set value in this embodiment will be described. In FIG. 1, when the valve 40 is open, the fluid in the cylinder 11 passes through two passages, the first orifice 20 and the bypass passage 24, and the fluid flows through the first and second chambers 18 and 18.
Since it is possible to move between No. 19 and No. 19, the flow rate of the fluid becomes large, and the damping force of the steering damper 10 becomes a relatively small normal state. This normal state is set so that a light steering can be performed during normal traveling and a disturbance up to a certain level can be dealt with.

In this state, if the first adjuster 16 and the second adjuster 30 are individually adjusted, the respective throttle amounts of the first orifice 20 and the second orifice 29 can be adjusted respectively, so that the initial setting value of the damping force can be simplified. Be adjustable. Particularly, since the second orifice 29 produces a damping force only when the valve 40 is open, it is important to adjust the second orifice 29 for the initial setting value of the damping force in the normal state.

Bypass passage 24 when valve 40 is closed
Since the fluid is not passed through, the fluid in the first and second chambers 18 and 19 passes only through the first orifice 20, and the damping force becomes extremely large. Therefore, in this state, the damping force increases only in accordance with the throttle amount of the first orifice 20, and this throttle amount is predetermined by the initial set value by the first adjuster 16.

The damping force in the up state is such that even if a large disturbance such as an extremely large load is applied, the forward / backward movement of the piston rod 12 is restricted so that the handle 7 is hard to swing and straightness can be secured. Is set.

As described above, the first and second orifices 20 and 29 of which the throttles can be individually adjusted by the first adjuster 16 and the second adjuster 30 are respectively provided in the piston 1
7 and the bypass passage 24, it is possible to individually adjust the initial setting values of the high damping force side and the low damping force side, and it is possible to make unique settings according to the course and the skill of the occupant.

Next, automatic control of damping force at the time of disturbance will be described. First, FIG. 3 illustrates a method for controlling the opening / closing of the valve 40.
5 is a diagram showing a correlation with a load change applied to No. 5; FIG. The load changes are shown as convex when the load is applied to the right side of the handle and as downwardly convex when the load is applied to the left side of the handle.

In principle, the valve 40 is controlled to close when the load due to the disturbance exceeds the threshold level, and to open otherwise. The set value Vth of the threshold level is a boundary value between a disturbance that cannot be dealt with by the normal damping force and a disturbance that can be dealt with by the normal damping force, and is set by experience.

Therefore, the valve 40 is opened to provide the damping force in the normal state when the vehicle is traveling normally or when the disturbance level does not reach the threshold level in principle. On the other hand, if a disturbance above the threshold level occurs, the valve 4
0 closes to increase damping force and ensure straightness.

At this time, the load applied to the load sensor 15 due to the disturbance rises extremely quickly, so that the load sensor 15 can detect the disturbance quickly and input a detection signal to the control device 47 (FIG. 1). As a result, the drive control of the motor 44 by the control device 47 is immediately executed and the valve 40 is closed. Therefore, the damping force can be increased immediately after the occurrence of the disturbance, and the disturbance can be dealt with accurately.

In this embodiment, the amount of change in load per predetermined time (ΔM / Δt: absolute value) is constantly calculated by the control device 47 and compared with the judgment value A. The judgment value A is a value determined by experience, and when the load change amount becomes equal to or larger than the judgment value A (ΔM / Δt ≧ A), the valve 40 is immediately closed regardless of the set value Vth of the threshold level. .

In this way, when an extremely fast disturbance is applied, it is possible to respond promptly and accurately before the threshold level is reached, and it is possible to fully prepare for an extremely fast disturbance. However, this control condition is not always necessary and can be omitted.

FIG. 4 is a flow chart of the processing in the control device 47. After the start, it is judged whether or not the amount of change in load is the judgment value A or more based on the detection signal of the load sensor 15 (step 1). If NO, it is determined whether the load M is equal to or more than the threshold level set value Vth (step 2). If YES, a drive control signal is output to the motor 44 to open the valve 40, and the steering damper 10 is opened.
Increase the damping force of (step 3) and return to step 1.

If NO, the valve 40 is driven by the motor 44.
To open the steering damper 10 to the normal damping force (step 4) and return to step 1. If YES (ΔM / Δt ≧ A) in step 1, the process immediately proceeds to step 3 and the valve 40 is closed.

[0035]

As described above, according to the present invention, as an orifice for communicating between two chambers in a cylinder, a first orifice for varying a throttle provided in a piston and a throttle provided in a bypass passage communicating between the two chambers. Is provided with a second orifice that is variable, and an opening / closing valve is provided in the bypass passage.

For this reason, the throttles of the first orifice and the second orifice can be individually adjusted to individually adjust the initial setting values of the large damping force side and the small damping force side. It is now possible to set unique settings according to your skill. Further, when the on-off valve is closed, it is possible to quickly switch to the side with the larger damping force, and it is possible to deal with disturbance quickly and accurately.

[Brief description of drawings]

FIG. 1 is a sectional view of a steering damper according to an embodiment.

FIG. 2 is a side view of a main part of a motorcycle using an embodiment.

FIG. 3 is a graph showing a control method

FIG. 4 is a flowchart of the control device.

[Explanation of symbols]

 6 Steering shaft 7 Handle 10 Steering damper 11 Cylinder 12 Piston rod 15 Load sensor 17 Piston 16 First adjuster 18 First chamber 19 Second chamber 20 First orifice 24 Bypass passage 29 Second orifice 30 First adjuster 40 Valve 44 Motor 47 Control device

Claims (1)

[Claims] 1. A piston is fitted in a cylinder to divide the inside of the cylinder into two chambers, and these two chambers are communicated with each other through an orifice, and at least one of a piston rod to which the piston is attached and a cylinder is connected. In a steering damper that is connected to a handle-side member that rotates integrally with a handle and the other is connected to a vehicle body frame, the orifice communicates between a first orifice provided in a piston and a variable throttle, and the two chambers. The steering damper is provided with a second orifice provided in the bypass passage for changing the throttle, and an opening / closing valve provided in the bypass passage.