JPS5856907A - Damping force adjuster for suspension - Google Patents

Abstract

PURPOSE:To improve the drivability and the comfortability, by controlling the damping force of the suspension automatically in accordance to the actual car speed thereby optimizing the damping force of the suspension in the preset car speed region. CONSTITUTION:A car speed detecting means 1, meand 5, 6 for detecting whether the detected car speed is below the setting low car speed or above the setting high car speed and means 7 for holding the detected car speed signal for the predetermined interval and maintaining the suspension at the predetermined damping level, are provided. Consequently the damping force of the suspension is controlled automatically. For example when the low car speed detecting means 6 will produce the signal indicating that it is below 50km/h, the holding means 7 is disabled to stop the operation of the relay circuit 8 thus to deenergize the solenoid 9. Consequently the open valve of the suspension will open to increase the piston stroke and to reduce the damping force thereby the operation of the suspension is softened.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a damping force adjustment device for a suspension in a vehicle or the like.

Generally speaking, depending on the road surface condition, when the vehicle is traveling at high speed, the damping force of the suspension is set to a high level 1" in order to suppress rolling of the vehicle body due to downwind or pitching caused by the brakes and to improve steering stability. On the other hand, when the vehicle travels at low speeds, it is desirable to set the damping force of the suspension low in order to provide a comfortable ride.

For this reason, a system has been proposed in which the damping force of the suspension can be manually changed by turning on and off a switch. The structure was such that the damping ring could be set high at speeds above Km/h. However, since the on/off operation is a manual operation, there is a problem that such operation is cumbersome when the road condition is poor or when driving at night, and this actually impairs steering stability.

The present invention has been made to improve the problems of the conventional art θ), and particularly includes a vehicle speed detection means and a vehicle speed detected by the means that determines whether the vehicle speed is below a set low vehicle speed or above a set high vehicle speed. and a holding means for holding the detected vehicle speed signal for a certain period of time to maintain the suspension at a predetermined damping force level. The present invention provides a suspension damping force adjustment device that improves steering stability and ride comfort over the entire vehicle speed range.

Hereinafter, one embodiment of the present invention θ) will be specifically described with reference to the drawings.

FIG. 1 is a block circuit diagram of the present invention θ] damping force adjustment device θ). In the figure, numeral 1 is a pulse sensor that generates a number θ pulses proportional to the vehicle speed. For example, an on/off signal can be sent from a force reed switch on the main body side installed opposite to a magnet piece attached to the axle side. Output
It also consists of θ). 2 is an amplifier, which includes a circuit for shaping the pulse waveform from the DjlB pulse sensor 1 (θ);
) Mono multivibrator 3 is connected to amplifier 2. This θ) mono multivibrator 3 uses the rise or fall of θ pulse θ from the amplifier 2 to form a pulse with a predetermined pulse width θ.
A mono multivibrator 3 (to which a filter 4 including an integrating circuit is connected. Here, it outputs an average voltage (current) according to the pulse width θ). The average voltage is determined by the vehicle speed σ
] The voltage is at a level corresponding to the magnitude of the vehicle speed, and is input to the comparators 5 and 6i/(, which are the next stage high/low vehicle speed detection means. Also, one comparator 6 has a voltage level corresponding to the damping force of the suspension at a high predetermined value. Signal data of the vehicle speed (for example, 80 km/h) to be set to is input from the terminal 5α, and the signal data of the vehicle speed to be set to θ] comparator 6
The suspension J) damping force is set to a low predetermined value, and signal data indicating the vehicle speed (for example, 50 in/h) is input from the terminal 6α. 7 is each comparator 5 mentioned above.
, 6, and a solenoid 9 is connected to the output side of the holding circuit 7 via a relay circuit 8. This solenoid 9 controls the biasing of a member that adjusts the opening area of a valve hole or orifice provided in a piston or the like of the suspension body 1o.

In this embodiment, the suspension is operated in two damping modes, high and low, so the holding circuit 7 holds the output of the comparator 5 in the high-speed setting range, stops operating in the low-speed setting range, and turns off. You can do it like this.

Next, the effect will be described.

Now, the set vehicle speed of the comparator 5 is set to 80 Km/h, and the set vehicle speed f of the comparator 6σ) is set to <50 Km/h, and setting signals corresponding to these are input to each terminal 6α, 5b.

In such a state, when a stopped vehicle is started and gradually accelerated, the pulse sensor 1 detects the number θ per predetermined time.
A pulse is output, which is shaped into a waveform and input to the mono multivibrator 3. The rising edge of the pulse outputs a pulse voltage with a constant width σ), and this θ) output is input to the filter 4 and converted to a DC voltage. Ru. Subsequently, this DC voltage is input to the comparator 5.6 (θ), but as the vehicle accelerates, the voltage increases by 301 (m,/h...80
Km7/A, and the previously set vehicle speed θ)80Kn
When 1/A is exceeded, the comparator 5 outputs a missing signal and the signal holding circuit 7 holds the comparison signal output.

Subsequently, the relay circuit 8 is activated based on this held signal output, and continues to energize the solenoid 9 during the holding period. (Then, the opening valves of the suspension and/or valves are closed, and the damping force is maintained at a high level.
It is possible to suppress rolling and pitching during high-speed driving, thereby ensuring stability in handling. The relationship between vehicle speed, damping force, and σ) is shown by the curve α in FIG.

On the other hand, when driving at high speed, for example, when the vehicle speed is 80 km/
h to 701<m/h...50 Krn/h, and outputs a signal indicating that the vehicle speed has become less than 50 Km/h set by the comparator 6. Therefore, the holding circuit 7 becomes inactive, the operation of the relay circuit 8 stops, and the solenoid 9 becomes deenergized, and this state is maintained. θ)
As a result, the suspension σ) opening valve and the like open to increase the piston θ) stroke and reduce the damping force. Thus, when driving at low speeds of 50-2/h or less, it is possible to obtain the advantage of softening the suspension θ) operation to make the ride more comfortable. In the above, each set vehicle speed is set to +50 Km/h and 80 Km/h, but it goes without saying that any set vehicle speed other than these may be freely selected, such as =10 m/h and 70 Krn/h. The relationship between vehicle speed and damping force is shown in the curve σ in Figure 2.

By the way, when a vehicle is traveling at high speed and is about to enter a rough road, the brakes may be pressed.
If the damping force of the suspension were to decrease immediately, the front of the vehicle would sink into a nose-dive condition, and in the worst case, a part of the front of the vehicle could collide with a bump in the road, which is extremely dangerous and could be extremely dangerous for the occupants. Ride comfort also becomes extremely poor. Also, when driving at high speed on a rough road while driving at low speed, as soon as the vehicle speed reaches the set vehicle speed of 80 Km/h K, the suspension damping force becomes high, and the light rain will stop even if the previous 4 tensions are maintained. It is possible that the vehicle enters the high speed range while pitching, which may impair steering stability and become dangerous.

Therefore, timers 11 and 12 are connected between the comparators 6 and 6 and the signal holding circuit 7, respectively, as shown in FIG. By doing this, if you brake suddenly while driving at a high speed of 50 km/h or higher, the vehicle speed will drop to 50 km/h.
Even though the vehicle speed has significantly decreased below Km/h, by extending and holding the output of the comparator 5 by the set time using the timer 11, the vehicle speed has significantly decreased as shown by the dotted line curve C in FIG. Even though the damping force has decreased, the state of high damping force can be maintained for the set time.

In this way, nose dive during such braking operation can be effectively prevented. Although the set time in this case depends on the road conditions, it is necessary to set it in consideration of the vehicle speed range and acceleration/deceleration where the nose dive is small, and if necessary, the timer operation may be continued until the vehicle speed reaches the OK m/h. It is also possible to maintain a high damping force by the suspension θ).

Also, when the vehicle speed exceeds 80 km/h while driving on a rough road, the timer 12 extends the output of the comparator 6θ for a certain period of time, so that the attenuation is reduced as shown by the dotted curve d in Figure 2. The low force state can be maintained for the predetermined period of time. In this way, it is possible to appropriately absorb the impact of the vehicle when it enters a high speed.

On the other hand, instead of setting the low-speed set vehicle speed 50 Km/A and the high-speed set vehicle speed 80 Km/h k separately as described above, as shown in FIG. ) Mutual switching can also be performed automatically. However, in this case θ), timer 11.
Without 12, the switching point between high speed and low speed is the same vehicle speed of 60K.
In/h, the attenuation state changes constantly (θ), which causes a chill-lag operation, which is not desirable in practice.

However, by connecting the timer 11.12%' as shown in Fig. 4 σ) curves e and f, for example, when switching from high speed to low speed, the vehicle speed is delayed by 40 km/h. When switching from low speed to high speed, the damping force is increased at a time-delayed vehicle speed of 70 km/h (θ), and in reality, the non-chip lag operation as described above (σ) is performed. θ] which has the advantage of eliminating the worry of

In addition, in the above description, the solenoid is automatically energized or deenergized depending on the vehicle speed, and the damping force of the suspension is automatically adjusted based on this. Needless to say, the damping force can be manually adjusted as desired.

As shown in σ), if the vehicle speed (θ), high speed and low speed (θ) is determined in advance according to the road conditions, the damping force will be automatically adjusted when the vehicle speed reaches the set vehicle speed (θ). Adjustment is possible, and maneuverability can be ensured, especially at high speeds. In addition, during high-speed driving (θ), during sudden braking, the suspension can be maintained at a high damping force by operating a timer to prevent unexpected nose dive.

As explained above, according to the present invention, the vehicle speed detecting means for detecting the actual vehicle speed and the vehicle speed data obtained by the vehicle speed detecting means are equal to or higher than the set high vehicle speed that is -f for the suspension v (predetermined θ) high damping force. high vehicle speed detecting means for detecting that the vehicle speed data indicates that the suspension is less than a predetermined low damping force of 1C; The suspension retaining means maintains the operation of the suspension with the damping force adjusted based on the output from the means, and the suspension damping force is automatically controlled according to the actual vehicle speed, which is preferable depending on the road condition. By simply determining the high and low speed settings, the suspension damping force that is most preferable for the set vehicle speed can be automatically adjusted. In addition, by installing a timer that delays the low damping force adjustment of the suspension for a predetermined period of time when the vehicle speed during deceleration is at least below the set low vehicle speed, the timer function delays the timing of switching the damping force σ) and prevents sudden braking. You can prevent dangers such as nose dives. In this way, various effects such as vehicle running θ) can be prevented from inadvertent rolling or pitching, handling stability can be improved, and passenger comfort can be improved.

[Brief explanation of drawings]

Fig. 1 is a block circuit diagram of the damping force adjusting device according to the present invention, Fig. 2 is a damping force characteristic diagram of the damping force adjusting device according to the present invention, Fig. 3 is a damping force characteristic diagram of the damping force adjusting device according to the present invention, and Fig. 3 is a damping force adjusting device showing another embodiment. Figure 4 is a damping force characteristic diagram of the block circuit diagram. 1... Actual vehicle speed detection means 5.
・・・・・・・・・・・・High vehicle speed detection means 6...
......Low vehicle speed detection means 7...
...... Holding means 11.12... Timer

Claims (2)

[Claims] (1) a vehicle speed detection means for detecting the actual vehicle speed; The vehicle speed data adjusts the suspension to a predetermined θ.
) Low vehicle speed detection means for detecting that the vehicle speed is below the set low vehicle speed at which the damping force should be set, and retention for maintaining the operation of the suspension with the damping force adjusted based on the output from these high vehicle speed detection means or low vehicle speed detection means. 1. A suspension θ) damping force adjusting device, characterized in that the suspension θ) damping force is automatically controlled according to the actual vehicle speed. (2) a vehicle speed means for detecting the actual vehicle speed; a high vehicle speed detecting means for detecting that the vehicle speed data obtained by the vehicle speed detecting means is higher than a set high speed at which the suspension should be adjusted to a predetermined high damping force; and the vehicle speed data low vehicle speed detection means for detecting that the vehicle speed is lower than the set low vehicle speed, and the damping force of the suspension is adjusted based on θ) output from these high vehicle speed detection means or low vehicle speed detection means. At least during deceleration θ), when the vehicle speed falls below the set low vehicle speed, the suspension θ)
Suspension damping force adjustment bag a characterized by comprising a timer that delays low damping force adjustment for a predetermined period of time.