JPS6311492A - Damping force controller for steering damper - 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 (Field of Industrial Application) The present invention relates to improving the functionality of a steering damper provided in a steering wheel of a two-axle vehicle.

(Prior Art) For example, a steering damper as shown in FIG. 6 is known as a steering damper that damps vibrations transmitted from the front wheels to the steering wheel. The interior of the cylinder 2 ( ) is divided into oil chambers 22 and 23 on both sides by a freely slidable piston 21 housed therein, and the oil chambers 22 and 23 have check valves 24 and 23 respectively
It communicates with the pressure control valve 1 via. Further, the pressure control valve 1 communicates with an accumulator 27 that absorbs volume changes, and the accumulator 27 directly communicates with the oil chambers 22 and 23 via check valves 28 and 29. The pressure control valve 1 is configured to change the valve opening pressure by a current supplied from an external power source (not shown).

In this steering damper, when the piston 21 moves inside the cylinder 20 toward the oil chamber 22, the hydraulic oil in the oil chamber 22 passes through the check valve 24, pushes open the pressure control valve 1, and flows into the oil chamber 23 from the check valve 29. , when the piston 21 is displaced toward the oil chamber 23 side, the hydraulic oil in the oil chamber 23 flows into the check valve 2.
5. It flows into the oil chamber 22 through the pressure control valve i=f+ and the check valve 28. In either case, the resistance generated when the hydraulic oil passes through the pressure control valve 1 increases and generates a damping force. Note that by controlling the current supplied to the pressure control valve 1 in conjunction with a vehicle speed sensor and a steering wheel angle sensor (not shown), a damping force corresponding to IL speed and steering wheel angle can be obtained.

Furthermore, between the oil chamber 22 and the check valve 24 and the oil chamber 23
A steering damper has also been proposed in which an accumulator is interposed between the pressure control valve 1 and the check valve 25 to absorb minute vibrations that do not cause the pressure control valve 1 to open. Publication No.).

(Problem to be solved by the invention) By the way, when a two-wheeled vehicle lands from a jump or wheelie, or after passing a four-wheeler, when the direction of the steering wheel is different from the direction of travel, the grounding point of the front wheel is not aligned with the steering axis. Because it is not on the line, the so-called kick-pack phenomenon occurs in which the steering wheel swings forcefully due to the running resistance of the rear supination acting on the ground contact point at the same time as the front wheel lands. However, if the damping force of the pressure control valve 1 is set to be large in order to alleviate this problem with the steering damper, the damping force during normal driving also becomes large, making the overall handling extremely heavy.

On the other hand, if emphasis is placed on light handling during normal driving, the steering damper must be used to suppress the kick-pack phenomenon, and the shake of the steering wheel must be suppressed using physical strength. In other words, it has been difficult to achieve both nimble handling and suppression of the kick-pack phenomenon in the steering damper.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a steering damper control device that can temporarily increase damping force only in response to the kick-pack phenomenon.

(Means for Solving the Problems) The present invention provides a steering damper that controls the energization of a solenoid pressure control valve installed in an oil passage of the steering damper to change the damping force generated by the control valve. In the cargo force control device, a front wheel load detection means is interposed in the front wheel hydraulic shock absorber, and energization to the control valve is controlled to increase the damping force based on a decrease in the front wheel load detected by the detection means. Equipped with a control circuit.

(Function) Before the kick-pack phenomenon, the load applied to the front wheels decreases compared to normal driving, so the detection means detects this decrease in front wheel load, and the control circuit energizes the solenoid of the depletion valve based on this. control to increase damping force.

(Example) Embodiments of the present invention are shown in FIGS. 1 to 5.

In Fig. 1, reference numeral 1 denotes a pressure control valve installed in the oil passage in the steering damper, and the valve opening pressure and the air pressure after opening are controlled by the control current ■ supplied through the control unit 2, which is a control circuit. Change resistance. A signal from a pressure sensor 3 provided to detect the load on the front wheel and a signal from a steering wheel angle sensor 4 installed in the steering wheel are input to the control unit 2. The pressure sensor 3 is installed inside the front 7 oak that supports the front wheels, and detects the pressure P of the hydraulic oil that increases due to the contraction of the front 7 oak, and outputs a signal to the control unit 2. Further, the steering wheel angle sensor 4 detects the rotation angle φ of the steering wheel from the longitudinal direction of the vehicle body and outputs a signal to the control unit 2.

The control unit 2 receives pressure P from the pressure sensor 3.
The preset pressure P (I
A differential amplifier IIa 5 is provided which outputs the difference Δl) from the difference Δl). Note that the pressure P (IG) is the hydraulic fluid pressure inside the front fork at the balanced position during normal running. Further, a comparator 6 is provided to compare this difference ΔP with 8Pma which is set separately. ΔPmax is the pressure P inside the 70-ton hook when the front wheel is suspended in the air. and set value p (tc
), and only when ΔP is equal to or exceeds ΔPn+ax, the comparator 6 conducts the relay 7 and draws a constant current from the power supply 8. is supplied to the adder circuit 9. The control unit 2 also includes a function conversion circuit 1 () that converts the pressure difference Δ]J output from the differential amplifier 5 into a corresponding proportionality constant K as shown. Furthermore, the rotation angle φ of the handle detected by the handle angle sensor 4 is determined by the rotation speed dφ of the handle.
/di and the same rotation speed dφ/d
A multiplication circuit 12 that multiplies t by the proportionality constant K described above is provided. Signal current K・dφ/dt output from the multiplier circuit 12
is manually input to the adder circuit 9, and the adder circuit 5] combines this signal current K·dφ/clt and the above-mentioned constant current I.

The sum of the current (■) is output as the control current of the pressure control valve 1.

Next, the effect will be explained.

1jt when running stably on a track with no gate protrusions
For a load of 1 G acting on the i-wheel, the front wheel load is negative when braking or when passing a convex part, and is less than this when passing a fourth part. Furthermore, when the front wheels lift off the ground, such as when jumping or doing a wheelie, the load on the front wheels becomes zero. Front 7-hole elastic body 1d that supports the front wheel
changes depending on the front wheel load, and the pressure P of the hydraulic oil sealed in the front fork also changes accordingly.

In this control system, the control unit 2 controls the pressure control valve 1 as follows based on the hydraulic oil pressure P detected by the pressure sensor 3 and the handle angle φ detected by the handle angle sensor 4.

When the detected pressure P of the pressure sensor 3 is equal to but exceeds the hydraulic pressure P (IG) in the IG load state, the output ΔP of the differential amplifier 5 is 0, so the function conversion circuit 1
The proportional constant converted by 0 is 0, and the comparator 6 does not switch the relay 7 either. Therefore, Canada
As shown in FIG. 2, the control current l output from the 11'il path 5 becomes O regardless of the rotational speed dφ/di of the handle. That is, the pressure control valve 1 of the steering damper is kept fully open, and as shown in Fig. 3, the damping force is only slightly generated as the steering wheel speed dφ/dv increases and is suppressed to the minimum, so the steering wheel operation is light. , will not make the driver tired.

Next, when the front wheel passes through the four parts, the 70-ton fork moves and the pressure P decreases, and the output of the differential amplifier 5 of the control unit 2 becomes ΔP>0. As a result, the function conversion circuit 10 converts Δ11 into the corresponding proportionality constant K, multiplies it by W, and inputs the signal to the circuit 12.

-No. 11 The steering wheel rotation speed dφ/dt obtained by differentiating the steering wheel angle φ detected by the steering wheel angle sensor 4 with the differentiating circuit 11 is input to the calculation circuit 12, and the multiplication circuit 1
2 outputs the product K·dφ/dt to the adder circuit 9 as a signal current. Also, if the front wheel is not floating in the air at this time, Δ1) <ΔPma, so the comparator 6 does not switch the relay 7, and the power supply 8, i, and 1111 from the t7111 circuit 9 are disconnected. There is.

Therefore, the adder circuit 9 outputs the signal current K·dφ/dt inputted from the multiplier circuit 12 as it is to the pressure control valve 1 as the control current I. Therefore, this control current ■ is proportional to the proportional constant and the handle rotation speed dφ/dt.
It changes as shown in W1 to W in the figure, and the damping force generated by the pressure control valve 1 also changes correspondingly as shown in the figure Pt53. Therefore, when the front wheel load is small, the steering damper generates a large damping force to prevent the steering wheel from swinging after passing through the four parts.

Furthermore, when the front wheel is completely suspended in the air, such as during a no-yump or wheelie, the detected pressure P of the pressure sensor 3 is
becomes the minimum, and the output ΔP of the differential amplifier 5 reaches the set value Δpm
It becomes equal to ax. As a result, a signal current is output from the comparator 6, the relay 7 becomes conductive, and a constant current I is applied to the adding circuit 9 from the electric current wi8. is output. Therefore, the control current (■) output from the adder circuit 9 is added to the current No. 48 K·dφ/dt input from the multiplier circuit 12. is added. Therefore, as shown in Fig. 2, the control current I is ()
, and the handle rotation speed dφ/ with ■ o as the starting point.
-L rises with dt. As a result, the damping force generated by the pressure control valve 1 becomes as shown in W in FIG. 3, which is the initial value F.

As well as holding the handle stably in the air! ! '
For kick pack when landing on J wheel, handle speed dφ
The destructive force that further increases according to /dL strongly damps the vibration of the steering wheel. Therefore, when you land, the handlebars will not be taken off, and your arms that support the handlebars will not be subject to a large amount of force. Moreover, after landing, the pressure P detected by the pressure sensor 3 rises by 2 due to the contraction of the front 7 oak, and the control current 2 outputted by the control unit 2 increases. decreases, so the pressure f? 7 The reducing force of control valve 1 also decreases at the same time. Return to state. Therefore, the steering wheel can be operated with light force after landing.

Note that instead of using the pressure sensor 3 as the means for detecting the 111f wheel load, the stroke position of the steering damper may be detected. In this case, the stroke sensor that detects the stroke position is structured so that a plurality of reed switches installed on one side of the steering damper cylinder and the piston rond are switched sequentially by a magnet attached to the other side with the stroke, or one is installed on the cylinder side. It is configured using a so-called differential transformer, which has primary and secondary coils, and when a magnetic body provided on the piston side is displaced relative to these coils, the output voltage of the secondary coil changes according to the displacement. . The setting value of the differential amplifier 5 of the control unit 2 is the stroke position X (1,) under the IG load condition, and the function conversion circuit is set so that the proportional constant K is determined for the difference ΔX from the detected stroke position 10.

Similarly, the set value of the comparator 6 is 8Xts, which is the difference between the stroke position X and X(iG) when the Mfj wheel is suspended in the air.
Set to a.

Further, the present invention can also be implemented with a configuration as shown in FIG. 4 without using the steering wheel angle sensor 4.

In this case, since the control current I is changed using only the detected pressure 1 of the pressure sensor 3 as a parameter, the normal running? ? Even when the front wheel is floating, the rate of increase in damping force with respect to the steering wheel rotation speed dφ/di does not change as shown in Figure 5.
As shown in FIG. 4, the control unit 2 has a simple configuration consisting of only a differential amplifier 5 and a function conversion circuit 10, and the steering wheel angle sensor 4 is also unnecessary, so it can be implemented at low cost.

(Effects of the Invention) As described in (1) below, the present invention provides a means for detecting the load on the front wheels, and a control for controlling energization to the pressure control valve of the outer steering damper based on the front wheel load detected by the detecting means. Because it is equipped with a circuit, when the front wheel becomes airborne due to a jump, wheelie, or passing a four-way road, the damping force of the steering damper can be temporarily increased in preparation for the kick-pack phenomenon that occurs when the 111J wheel touches down. can. In other words, it is possible to prevent the steering wheel from shaking due to the kick-pack phenomenon without affecting the damping force during normal driving, which has the effect of greatly improving steering stability.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG.
The figure is a graph showing the control voltage characteristics on the same side, Figure 3 is a graph also showing the damping force characteristics, Figure 4 is a block diagram showing the configuration of another embodiment, and Figure 5 is also the same showing the damping force characteristics. It is a graph. Further, FIG. 6 is a circuit diagram of a control system of a steering damper showing a conventional example. 1...Pressure control valve, 2...Control unit,
3...Pressure sensor.

Claims (1)

[Claims] In a damping force control device for a steering damper that controls energization to a solenoid pressure control valve installed in an oil passage of a steering damper to change the damping force generated by the control valve, a means for detecting a front wheel load is provided. A damping force control device for a steering damper, comprising a control circuit that controls energization of the control valve so as to increase the damping force based on a decrease in the detected front wheel load.