JPH04215514A - Suspension control system - Google Patents

Abstract

PURPOSE:To set a plurality of suspensions to desired control positions with a simple switch, lever mechanism or the like in a suspension control system of a truck or the like having a shock absorber and other suspensions variable in the damping force respectively interposed in the chassis and carbureter sides. CONSTITUTION:While a damping force of the carbureter side suspension is constituted to be stepwise or infinitely controlled following a damping force of the chassis side suspension, the following operation is shut off by a predetermined change-over operation and characteristically the damping force of the cargureter side suspension can be maintained constant irrespective of the damping force of the chassis side suspension.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a suspension control system for trucks, etc., in which a shock absorber or other suspension capable of variable damping force is interposed on each of the chassis side and the driver's cab (hereinafter referred to as the cab). The present invention relates to a suspension control method that allows the plurality of suspensions to be set at desired control positions using a simple switch mechanism, lever mechanism, or the like.

0002

[Prior Art] Shock absorbers that constitute suspensions have been used in the past to improve steering stability and ride comfort depending on vehicle speed and road conditions while driving, or to prevent sudden nose dive during braking. Suspension control devices are known in which the damping force can be varied in stages and the damping force can be switched as appropriate. (Special Public Interest Publication No. 63-63401)

[0003] This type of device is configured to be able to automatically vary the damping force by determining the driving condition, the presence or absence of braking force, or the road condition based on various signals that detect vehicle speed, deceleration, etc. However, there are individual differences in the perceived damping force, and there are also drivers who prioritize the feeling of speed over ride comfort, so in conventional suspension control devices, it is possible to switch between automatic control and manual control as appropriate. configure,
In the case of manual control, the damping force can be switched between two or three stages using a damping force changeover switch or the like.

[0004] On the other hand, in trucks and other vehicles, in order to ensure a stable ride during long-distance driving, suspensions are installed not only on the chassis side (between the tires and the chassis) but also on the cab side (between the chassis and the cab). exists.

[0005]

[Problems to be Solved by the Invention] However, in such a device, configuring each of the suspensions on the chassis side and the cab side to be manually adjustable using a switch mechanism individually makes the operation complicated and also causes switching errors. is likely to occur.

In view of the drawbacks of the prior art, the present invention provides a suspension control system that allows a desired or optimal damping force to be set by a simple switch or lever operation even in a vehicle in which suspension is provided on both the chassis side and the cab side. The purpose is to provide a method.

[0007]

[Means for Solving the Problems] The first aspect of the present invention is that the suspension damping force on the cab side can be controlled stepwise or steplessly by following the damping force on the chassis side by operating a switch or a lever. The first feature and the second feature are that the following operation is cut off by a predetermined switching operation, and the damping force of the cab side suspension is maintained constant regardless of the damping force of the chassis side suspension. At the point.

The first feature of the second invention is that the suspension damping force on the cab side can be controlled in stages by following the damping force on the chassis side by an input signal from a switch. The key point is that the control of both suspensions is shifted to automatic setting when the switch is turned off.

[0009]

[Operation] According to the first invention, since the deceleration of the suspension on one side is controlled to follow the deceleration of the suspension on the other side, even if suspensions are provided on the chassis side and the cab side respectively. Even in such a case, it is possible to control the deceleration of both suspensions with a single manual operation, so that a desired damping force can be set with a simple switch or lever operation without making any operational mistakes.

[0010] Also, uniformly matching the damping forces of the suspensions on the chassis side and the cab side may not necessarily be desirable due to road conditions or individual differences in sensation, and it may not be preferable to give priority to the sense of speed over ride comfort. There are also drivers that do this.

In such a case, the above request can be easily achieved by maintaining the damping force of the cab side suspension at a constant level regardless of the damping force of the chassis side suspension, and more specifically, by maintaining the damping force at a level between hard and soft. This can be achieved smoothly with simple operations.

Now, the above operation is effective for manual operation, but if the manual operation and automatic operation are to be performed in parallel, a separate changeover switch must be provided, and the changeover switch must be switched to the auto side. Users may forget what they are doing and perform manual operations, which can lead to operational errors.

Therefore, in the present invention, the automatic/manual changeover switch is not specially provided, but when the manual operation switch is turned off, the control is given priority and the setting is shifted to the automatic setting. This allows the system to automatically switch to auto setting even if you forget to perform an operation, so there is no problem with ride comfort or steering stability.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, and relative positions of the components described in this example are not intended to limit the scope of this invention, but are merely illustrative examples. Not too much.

FIG. 2 shows a schematic configuration of a cab-over type truck according to an embodiment of the present invention, in which a pair of left and right cab suspensions 3 are provided between the cab 1 and the chassis 2, on the front end side and the rear end side of the cab 1, respectively. A pair of left and right chassis suspensions 4 are provided on the front wheel side and the rear wheel side between the axle and the chassis 2, respectively.
are arranged respectively.

As is well known, the suspensions 3 and 4 include shock absorbers 3A and 4A whose damping force can be varied in stages by voltage control to an internal actuator, as well as coil springs or roof springs (not shown). They are installed consecutively. That is, more specifically, the shock absorber 4A on the chassis 2 side has a damping degree that is switched between two levels, large and small, and thereby the chassis suspension 4 is set to hard and soft (hereinafter referred to as hard/soft).
This enables two-stage setting. On the other hand, the shock absorber 3A on the side of the cab 1 has a damping degree that can be switched in three stages: large, small, and medium.As a result, the cab suspension 3 can be set in three stages: hard, soft, and the middle (hereinafter referred to as hard/soft/normal). possible.

Further, electrical components such as various sensors for performing suspension control, which will be described later, are attached to the inside of the cab 1 or the chassis 2. Cab 1 for electrical equipment
To explain in order of the inside and the chassis 2 side, 11 is an ECS mode changeover switch for manual control, and consists of a hard switch 11a and a soft switch 11b for setting the damping degree of the shock absorber 4A on the chassis 2 side to be large or small.

Reference numeral 12 denotes a changeover switch on the cab suspension 3 side, which selects between an auto mode in which the damping degree is set to hard and soft based on the control signal from the control side, and a normal damping degree regardless of the damping degree on the chassis 2 side. It is configured to be switchable between a normal mode and a normal mode. 13 is a brake switch, which is turned on by stepping on the foot brake. Reference numeral 20 denotes a control unit in which various ICs for performing control operations described later are incorporated.

A pair of acceleration sensors 14 are installed near the left and right front wheels, and detect vertical movements of the vehicle such as pitching and bouncing. (hereinafter referred to as vertical G sensor)
A vehicle speed sensor 15 is attached to the output shaft of the transmission 16 and detects the traveling speed of the vehicle.

FIG. 3 is a control block diagram showing the overall configuration of the suspension control mechanism built into the vehicle, including a control unit 20 in which a manual control circuit 20A and an automatic control circuit 20B are built, the chassis 2 side and the cab. Control circuits 21 and 22 that switch the damping level of the actuators incorporated in the shock absorbers 3A and 4A on the 1 side, respectively.
Consisting of The auto control circuit 20B in the control unit 20 includes the pitching/bouncing control circuit 2
0B1, an unsprung (suspension spring on the chassis side) flapping control circuit 20B2 when going over a step/protrusion, and a nose dive control circuit 20B2. The control signal is output to control circuits 21 and 22 on the chassis 2 side and the cab 1 side, respectively, to perform predetermined control.

The control circuit 22 on the cab 1 side includes an auto/normal selector switch 12, a power relay 23, and a power supply unit that outputs a voltage corresponding to the attenuation level (hard/soft/normal) to the actuator in the shock absorber. 24, etc., and the changeover switch 12
When is in auto mode, generally a control signal corresponding to the attenuation level on the chassis 2 side is sent to the control unit 20.
is output to the power supply unit 24 via the power relay 23, thereby supplying the voltage corresponding to hardware/software to the actuator 25. On the other hand, when the changeover switch 12 is switched to normal mode, the control unit 20 side By outputting an ON signal from the changeover switch to the power supply unit 24 via the power relay 23, a constant voltage corresponding to the normal mode can be supplied to the actuator 25, regardless of the control signal.

Next, the manual control method which constitutes the main part of the present invention will be explained step by step based on the flowchart shown in FIG. 1 and the time chart shown in FIG. First, after starting operation, the manual control circuit 20 in the control unit 20 is activated based on the signal from the mode changeover switch 11.
At A, first determine whether or not the hard switch 11a is turned on, and if it is turned on, then determine whether the changeover switch 12 on the cab 1 side is set to auto or normal, and if it is set to auto, the switch 12 on the cab 1 side The damping degree of the shock absorber 3A (actuator) on the cab 1 side is set to the hard side, and in the case of normal, only the chassis 2 side is set to hard and the cab 1 side GA is set to normal.

Next, if the hard switch 11a is OFF, it is then determined whether or not the soft switch 11b is ON, and if it is ON, the selector switch 12 on the cab 1 side is set to auto/normal in the same manner as above. If it is auto, the damping degree of the shock absorber 3A on the cab 1 side as well as the chassis 2 side is set to the soft side, and if it is normal, only the chassis 2 side is set to soft and the cab 1 side is set to normal. Ru.

When both the hard switch 11a and the soft switch 11b are OFF, the system shifts to auto mode control. For example, when pitching/housing occurs, the control circuit 2 is activated based on the signal from the vertical G sensor 14.
The 0B1 side judges this, and based on the output control signal, both the chassis 2 side and the cab 1 side are set to hard.
Similarly, if a step/protrusion occurs, G sensor 1
This is judged on the control circuit 20B2 side based on the signal of 4, and both the chassis 2 side and the cab 1 side are set to soft based on the output control signal. High speed running state and control circuit 20B3
Both the chassis 2 side and the cab 1 side are set to hard based on the output control signal determined by the side, and when the brake switch is turned on, the deceleration corresponding to the change in vehicle speed per unit time is set. If it becomes below a certain level, the control circuit 20B4 side judges this and sets both the chassis 2 side and the cab 1 side to hard based on the output control signal.

[0025]

As described above, according to the first invention, even when suspensions are provided on both the chassis side and the cab side, such as in a cab-over type truck, the deceleration of both suspensions can be controlled by one manual operation. This makes it possible to set the desired damping force with a simple switch or lever operation without making any operational mistakes.

Furthermore, according to the present invention, the damping force of the suspension on the cab side can be maintained constant without having to follow the damping force of the suspension on the chassis side, so that the suspension control state can be changed depending on the road condition etc. This further improves the product quality and the value of use.

According to the second invention, even when manual suspension control operation and auto control operation are selectively performed in parallel, the automatic/manual changeover switch is not specially provided, and when the manual operation switch is turned OFF, The above control can be prioritized and shifted to auto setting, which improves operability, and even if you forget to operate it, it automatically shifts to auto setting, so there is no problem with ride comfort or steering stability. . It has various effects such as

[Brief explanation of the drawing]

[Fig. 1] Flowchart diagram showing a manual control method for suspension control, which is the main part of the present invention.

FIG. 2 is an overall configuration diagram showing a schematic configuration of various parts incorporated in a cab-over type truck according to an embodiment of the present invention.

FIG. 3 is a control block diagram showing the overall configuration of the suspension control mechanism built into the vehicle.

[Figure 4] Time chart diagram of the manual control method shown in Figure 1

[
Explanation of symbols] 1 Cab 2 Chassis 3, 4 Suspension

Claims (2)

[Claims] Claim 1: In a suspension control system for a vehicle in which a suspension with variable damping force is interposed on each of the chassis side and the cab side, the suspension damping force on the cab side is made to follow the damping force on the chassis side, and the damping force is adjusted gradually or completely. The present invention is characterized in that it is configured so that it can be controlled in stages, and that the following operation is interrupted by a predetermined switching operation, so that the damping force of the cab side suspension can be maintained constant regardless of the damping force of the chassis side suspension. Suspension control method Claim 2: In a suspension control system for a vehicle in which a suspension with variable damping force is interposed on each of the chassis side and the cab side, the suspension damping force on the cab side follows the damping force on the chassis side by an input signal from a switch. A suspension control system characterized in that the suspension control system is configured so that the control can be controlled in stages, and the control of both suspensions can be shifted to automatic setting when the switch is turned off.