JPS60157910A - Suspension device of vehicle - Google Patents

Abstract

PURPOSE:To improve the riding comfortableness by providing an operation releasing means which releases the operation of a restraining means by a control means, according to the result derived from a discriminating means so as to adjust the operation period of the restraining means to be a necessary/sufficient and optimum period needed according to the oscillating state of avehicle. CONSTITUTION:A suspension system consists of attenuation force variable shock absorbers 13a-13d and torsional rigidity variable stabilizers 14f and 14r. A controller 50 which controls driving circuits 31 and 45 consists of an interface circuit 51, a processor 52 and a memory 53. The processor 52 discriminates the turning state of a vehicle according to both the detected signals of a car speed detector 1 and a steering angle detector 2. After starting the control of absorbers 13a-13d and the stabilizers 14f and 14r, the processor makes interruption action according to the detected signals of the ground clearance detector 35 of each of the absorbers 13a-13d. For the purpose of restraining the rolling state, the interruption treatment is executed after the absorbers 13a-13d and the stabilizers 14f and 14r are controlled to increase the attenuation force and the torsional rigidity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a suspension system for a vehicle that is controlled to suppress rocking due to rolling or pitching of the vehicle.

[Prior art]

As a conventional suspension system for a vehicle, there is one shown in FIG. 1, for example. Namely, 1 is a vehicle speed detector, 2 is a steering angle detector, 3 is a throttle opening detector, 4 is a stop lamp switch, and 5 is an automatic transmission inhibitor switch, which constitute the vehicle condition detection means 6. has been done. Each detection signal from the vehicle condition detection means 6 is input to the microcomputer 7, which performs predetermined arithmetic processing and outputs a control signal according to the vehicle condition to control the damping force of the variable damping force shock absorber 8. It is output to device 9. In this case, the control by the microcomputer 7 includes the following aspects.

First, when it is determined that the acceleration applied to the vehicle body will increase based on the detection signal of the throttle opening detector 3, the damping force of the variable damping force shock absorber 8 is increased for a predetermined period of time to prevent the vehicle body from starting off. Suppression and exerts anti-splash function.

Furthermore, when it is determined that the roll of the vehicle will increase based on the detection signal of the steering angle detector 2, the damping force of the variable damping force shock absorber 8 is increased for a predetermined period of time to suppress the roll when turning, thereby exerting an anti-roll function. let

Furthermore, when braking in a high-speed range is detected based on the detection signals from the vehicle speed detector 1 and the stop lamp switch 4, the damping force of the variable damping force shock absorber 8 is increased for a predetermined period of time to suppress nose dive and prevent anti-dive. Demonstrate functionality.

When it is detected that the automatic transmission has been shifted from the neutral or parking range to the D range based on the detection signal of the inhibitor switch 5, the damping force variable shock is activated for a predetermined period of time after the inhibitor switch 5 is turned from on to off. The damping force of the absorber 8 is increased to suppress the vehicle's tail-sloping that occurs when a shift operation is performed while the vehicle is stopped, thereby demonstrating the anti-slip function.

However, in such conventional suspension systems for vehicles, the system detects a state that causes rolling or pitching of the vehicle, starts control to increase the damping force of the variable damping force shore absorber, and then adjusts the damping force after a predetermined period of time has elapsed. Since the damping force is configured to return to its original state, even when pitching or rolling has subsided within a predetermined time, damping force control continues, and the damping of the variable damping force shock absorber continues until the predetermined time is reached. The problem was that the force was maintained at a high level, resulting in a decrease in ride comfort and running stability.

[Purpose of the invention]

The present invention was made by focusing on such conventional problems, and detects a rolling state or a rocking state due to pitching, and when the amount of displacement falls within a predetermined range, the rolling or pitching is suppressed by a suppressing means. The purpose is to solve the above problem by ending the suppression.

[Structure of the invention]

In order to achieve the above object, the present invention includes a suppressing means for suppressing rolling or pitching of a vehicle, which is attached to at least one of a front wheel or a rear wheel, as shown in the basic configuration diagram of FIG. A vehicle comprising: a vehicle state detecting means for detecting vehicle state detecting means; and a control means for operating the suppressing means based on a detection signal of the vehicle state detecting means; A state detecting means and a roll angle or a pinch angle of the vehicle or a displacement amount corresponding thereto are detected based on a detection signal of the vehicle rocking state detecting means, and whether the detected value is continuously within a predetermined range for a predetermined period of time. The present invention relates to a suspension system for a vehicle, characterized in that it comprises a determining means for determining whether or not the present invention is present, and an operation canceling means for canceling the operation of the suppressing means by the control means based on the determination result of the determining means.

[Effect]

A suppressing means for suppressing rolling or pitching of the vehicle, which is attached to at least one of the front wheels or the rear wheels, a vehicle state detecting means for detecting a vehicle state, and the suppressing means is actuated based on a detection signal from the vehicle state detecting means. In a vehicle equipped with a control means, the vehicle oscillation state detection means detects the oscillation state due to rolling or pitching of the vehicle, and based on the detection signal, the determination means determines the roll angle or pitch angle of the vehicle or the amount of displacement corresponding to these. and determining whether the detected value continues to be within a predetermined range for a predetermined period of time, and further, based on the determination result of the determination means, the activation of the suppressing means by the control means is canceled by the activation canceling means. Accordingly, when the rocking state of the vehicle is brought to an end, the suppressing means is returned to its original state, thereby improving riding comfort and running stability.

〔Example〕 The present invention will be explained below based on the drawings.

FIG. 3 is a schematic configuration diagram showing one embodiment of the present invention;
4 is a sectional view showing an example of a variable damping force shock absorber applicable to the present invention. FIG. 5 is a block diagram showing a control circuit thereof. FIG. It is a sectional view showing an example.

In Fig. 3, 10 is the vehicle body, lla and llb are the front wheels,
11c and 11d are rear wheels, and a suspension system 12 is interposed between these vehicle body 10, front wheels 11a and llb, and rear wheel 11C1lid.

The suspension system 12 includes variable damping force shock absorbers 13a to 13a disposed between the vehicle body 10 and each wheel 112 to 11d.
13d and between the front wheels 11a and llb and the rear wheels 11c and ll
Torsional rigidity variable stabilizer 14f, 1 arranged between a
4r.

Each of the variable damping force shock absorbers 13a to 13d has a monotube type shock absorber configuration, as shown in FIG. , and a free piston 19 is disposed at the bottom of the free piston 19, whereby the upper chamber 20. A middle chamber 21 and a lower chamber 22 are defined. The piston 17 has an upper chamber 20.
A liquid passage 23 is formed which communicates between the upper chamber 20 and the middle chamber 21. The middle chamber 21 is filled with liquid, and the lower chamber 22 is filled with high-pressure gas.

Further, a cylindrical body 28 made of a non-magnetic material is fixed to the upper end of the piston iron 18, and a detection coil 27 for detecting the amount of displacement of the piston iron 18 is wound inside, and the lower part thereof covers the cylinder tube 15.

The solenoid 24 has a lead wire 29 led out to the outside through a central opening 30 formed in the center of the piston rod 18, and is connected to a drive circuit 31 that supplies excitation current. Further, as shown in FIG. 5, the detection coil 27 is incorporated in the LC oscillator 32 as a coil that determines its oscillation frequency, and is transmitted from the LC oscillator 32 based on the inductance change according to the amount of displacement of the piston rond 18. (A frequency oscillation output is obtained.Then, the oscillation output is supplied to the frequency-voltage converter 34 via a low-pass filter 33 that removes frequency components due to unevenness of the road surface, and the conversion output is used as a vehicle height detection signal. is output as

These detection coils 27°LC oscillator 32. The low-pass filter 33 and the frequency-voltage converter 34 constitute a vehicle height detector 35 as a means for detecting vehicle rocking state.

Further, each of the torsional rigidity variable stabilizers 14f and 14r has a U-shaped torsion bar 36 as shown in FIG.
is divided into two halves 36a and 36b at the center, and a torsionally variable rigidity mechanism 37 is formed at the opposing end of each half 36a and 36b. This torsional rigidity variable mechanism 37
A cylindrical part 38 fixed to the end of the half body 36a, and a half body 36b formed at the end of the half body 36b and loosely fitted into the cylindrical part 38.
and an O-ring 40 that is attached to the tip of the cylindrical portion 38 and slides on the outer peripheral surface of the half body 36b.
It has an end cover 41 equipped with. A chamber 42 is formed by the end surface of the half body 36a, the cylindrical portion 38, and the end surface of the disk portion 39, the cylindrical portion 38, the disk portion 39. A magnetic fluid is sealed in each of the chambers 43 formed by the half body 36b and the end cap 41.

When a magnetic field is applied to this magnetic fluid, the magnetic particles are attracted into the magnetic field depending on the strength of the magnetic field, creating a dense part and a sparse part of the magnetic particles, and the magnetic particles located in the dense part The density of the particles determines the internal frictional resistance of this magnetic fluid. Utilizing these characteristics of magnetic fluid,
To impart torsional rigidity to a stabilizer and to continuously change the torsional rigidity.

An excitation coil 44 is wound around the outer peripheral surface of the cylindrical portion 38 in order to apply a magnetic field to the magnetic fluid.

A drive circuit 45 that supplies the excitation current is connected to the excitation coil 44, and the excitation current from the drive circuit 45 excites the excitation coil 44 to form a magnetic field that acts on the magnetic fluid.

Reference numeral 50 denotes a control device for controlling the drive circuits 31 and 45, and is composed of a microcomputer. As shown in FIG. 7, this control device 50 mainly includes an interface circuit 51. It is configured with an arithmetic processing unit 52 and a storage device 53.

The interface circuit 51 includes a vehicle speed detector 1°, a steering angle detector 2. Throttle opening detector 3. Stop lamp switch 4. Detection signals from the inhibitor switch 5 and the vehicle height detector 35 are supplied.

The arithmetic processing unit 52 contains damping force control registers 542 to 54d indicating the control state of the damping force of the variable damping force shock absorbers 132 to 13d and a control state of the roll rigidity of the variable torsional rigidity stabilizers 14f and 14r. It has roll stiffness registers 55f, 55r, and when these registers 54a to 54d, '55f, 55r are set, a control signal C3a with a logical value of "1" operates the drive circuit 31°45 via the interface circuit 51.
~C3d, C3f, and C3r are output, and the damping force variable shock absorber 1 is output from the drive circuit 31.45 accordingly.
38-13d solenoids 24. The excitation coils 44 of the variable torsional rigidity stabilizers 14f and 14r are excited to increase the damping force of the variable damping force shock absorbers 13a to 13d, and the variable torsional rigidity stabilizers 14f and 14r are
Increases torsional rigidity. In addition, each register 54a to 54d
.

When 55f and 55f are reset, the control signals C3a to C3d, C3f, and C3r have a logical value of "0", and the excitation current from the drive circuit 31.45 is cut off, and the damping force variable shock absorbers 13a to 13d are The damping force is reduced, and the torsional rigidity variable stabilizer 14f,
14r roll stiffness is reduced.

The storage device 53 stores at least predetermined programs and various setting values necessary for the arithmetic processing unit 52 to perform arithmetic processing.

The arithmetic processing unit 52 determines the turning state of the vehicle based on the detection signals of the vehicle speed detector 1 and the steering angle detector 2. Variable damping force shock absorber 13a on the axle 11a, 11C side.

Damping force control register 54 to increase the damping force of 13c.
a, 54c to control signal CSa.

C3c is set to a logic value "1", and the drive circuit 31 is set accordingly.
An excitation current is output from the solenoid 24 of the variable damping force shock absorber 13a, 13c. Therefore, the damping force of the variable damping force shock absorbers 13a, 13c is increased. At the same time, the torsional stiffness control registers 55f and 55r are set to set the control signals C3f and C3r to logical value "1", and the excitation current is supplied from the drive circuit 45 to the excitation coils 44 of the torsional stiffness variable stabilizers 14f and 14r to control these. It is excited to increase its torsional rigidity, and the rolling of the vehicle is suppressed through the cooperation of the variable damping force shock absorbers 13a, 13c and the variable torsional rigidity stabilizers 14f, 14r.

In addition, the arithmetic processing unit 52 determines the sudden acceleration based on the detection signal of the throttle opening detector 3, and sets the damping force control registers 54c and 54d in order to suppress the swash phenomenon at the rear of the vehicle body that occurs during the sudden acceleration. to increase the damping force of variable damping force shock absorbers 13c and 13d,
Suppress the scattering phenomenon.

Further, the arithmetic processing unit 52 determines the braking state in a high vehicle speed range based on the detection signals of the vehicle speed detector 1 and the stop lamp switch 4, and is configured to suppress the nose dive phenomenon at the front of the vehicle body that occurs during braking. , damping force control register 5
4a and 54b to increase the damping force of the variable damping force shock absorbers i3a and 13b to suppress the nose dive phenomenon.

Further, the arithmetic processing unit 52 determines the shift of the automatic transmission from the neutral or parking range to the D range based on the detection signal of the inhibitor switch 5, and in order to suppress the shift drift phenomenon that occurs at the time of the shift. The damping force control registers 54a, 54b (or 54c, 54d) are set to increase the damping force of the variable damping force shock absorbers 13a, 13b (or 13c, 13d) to suppress the shift drift phenomenon.

Furthermore, after starting the control of each of the variable damping force shock absorbers 13a to 13d and the variable torsional rigidity stabilizers 14f and 14r, the arithmetic processing unit 52 detects the vehicle height detector 3 of each of the variable damping force shock absorbers 13a to 13d.
Based on the detection signal No. 5, the interrupt processing shown in the flow chart of FIG. 8 or FIG. 9 is executed.

Here, the flowchart in FIG. 8 shows the process of canceling the rolling suppression state when the vehicle is controlled to suppress the rolling state due to turning, and as described above, the process is performed to suppress the rolling state. Variable damping force shock absorbers 138 to 13d and variable torsional rigidity stabilizer 1
The interrupt processing is executed after 4f and 14r are controlled to increase their damping force and torsional rigidity.

That is, first, in step (3), the detection signals of the vehicle height detectors 35 of the left variable damping force shock absorbers 13a and 13c are read, their average values are calculated, and this left side average value is stored in a predetermined storage area of the storage device 53. Remember.

Next, in step (2), the detection signals of the vehicle height detectors 35 of the right variable damping force shock absorbers 13b and 13d are read, their average values are calculated, and this right side average value is stored in a predetermined storage area of the storage device 53. .

Next, in step (2), the roll amount R is calculated by calculating the difference between the right side average value and the left side average value.

Next, in step (2), it is determined whether the roll amount R is within a predetermined range S (for example, ±0.5° in roll angle). If the determination result is R>S, the process returns to step (2), and if R≦S, the process proceeds to step (2).

In step ■, it is determined whether R≦S continues for a predetermined time (for example, 0.5 seconds), and if it is determined that it has not continued for a predetermined time, the process returns to step ■ and continues for a predetermined time. If it is determined that the

In step (2), the damping force control registers 542 to 54d and the roll stiffness control registers 55f and 55r are reset, and each control signal CS a -CS d and C3f, C3r is reset.
is set to logical value “0”. Therefore, each drive circuit 31.
The excitation current from 45 is cut off, and therefore the damping force of the variable damping force shock absorbers 13a to 13d and the torsional rigidity of the variable torsional rigidity stabilizers 14f and 14r are reduced and the original state is restored.

The flowchart in FIG. 9 shows the process for canceling the suppression state when control is performed to suppress pitching of the vehicle due to a shift phenomenon, a nose dive phenomenon, a shift shift phenomenon, etc. The interrupt process is executed after the variable damping force shock absorbers 13a to 13d are controlled to increase their damping forces.

That is, first, in step (2), the detection signals of the vehicle height detector 35 of the variable damping force shock absorbers 13a, 13b on the front wheel side are read, their average value is calculated, and this front wheel average value is stored in a predetermined storage area of the storage device 53. Remember.

Next, in step @, the detection signals of the vehicle height detector 35 of the variable damping force absorbers 13c and 13d on the rear wheel side are read, their average value is calculated, and this rear wheel average value is stored in the storage device 53. It is stored in a predetermined storage area.

Next, in step [phase], the pitch amount P is calculated by calculating the difference between the front wheel average value and the rear wheel average value.

Next, in step [phase], the pitch amount P falls within a predetermined range U −
(For example, it is determined whether the pinch angle is within ±0.5'). If the determination result is P>U, the process returns to step (2), and if P≦U, the process proceeds to step [phase].

In step [phase], P≦U for a predetermined time (for example, 0.
5 seconds) Determine whether it is continuing or not, and if it is determined that it has not continued for a predetermined time, return to step ■; if it is determined that it has continued for a predetermined time, move to step [phase] do.

In step @, the damping force control registers 54a to 5, id
is reset, and each control signal C31a-C31d is set to logical value "0". Therefore, the excitation current from each drive circuit 31 is cut off, and therefore the damping force of the variable damping force shock absorbers 13a to 13d is reduced and returned to their original state.

Next, the effect will be explained. First, the control device 50
Based on the detection signals from each detector 1 to 5, driving conditions such as corner entry, acceleration, starting, and braking are determined. In some cases,
damping force control registers 54a to 5 to suppress these
4d and/or roll stiffness control registers 55f, 55r
is cent. When each register is set, the control signal C3a-C3d corresponding to the registered register is
, C3f, and C3r take the logical value "1," and the damping force of the variable damping force shock absorbers 138 to 13d and/or the torsional rigidity of the variable torsional rigidity stabilizers L4f and 14r are increased.

In this state, the variable damping force shock absorber 13
a to 13d and/or torsional rigidity variable stabilizer 14f
, 14r is the rolling suppression control or the pitching suppression control, the interrupt process shown in FIG. 8 or 9 is executed.

That is, when the rolling suppression control is performed, the interruption process shown in FIG. 8 is executed, and first, in step (2), the average value of the left side vehicle height of the vehicle is calculated. Next, in step (2), the average value of the right side vehicle height of the vehicle is calculated.

Then, in step (2), the roll amount R is calculated by calculating the difference between the average value of the left vehicle height and the average value of the right vehicle height.

Next, in step (2), it is determined whether the roll amount R is within a predetermined range S or not. In this case, when the vehicle is turning, the roll amount R is large, so the process returns to step (2) and steps (2) to (2) are repeated again. Then, just before the turning state ends, the roll amount R becomes smaller,
Since R≦S, the process moves from step ■ to step ■. In step (2), it is determined whether or not R≦S continues for a predetermined time, and if it continues for a predetermined time, the process proceeds to step (2) where the damping force control registers 548 to 54d and the roll stiffness control register 55f are set. 55r is reset to end the interrupt processing.

When each register is reset, each control signal C31a-C32d is output from the control device 50.

C32f and C82r have a logical value of "0", and therefore the excitation current from each drive circuit 31.45 is cut off. As a result, the damping force of the variable damping force shock absorbers 13a to 13d and the torsional rigidity of the variable torsional rigidity stabilizers 14f and 14r are reduced and returned to their original states.

In addition, if the turning motion is repeated continuously, such as during slalom running, return from step ■ to step ■, repeat step ■ to step ■ until the turning motion is completed, and then step from step ■ to step ■ when the turning motion is completed. Then, the process moves to step (3), resets each register, and ends the interrupt processing.

If the pitching suppression control is performed, the interrupt process shown in FIG. 9 is executed, and first, in step (2), the average value of the vehicle height of the front wheels of the vehicle is calculated. Next, in step @, the average value of the vehicle height on the rear wheel side of the vehicle is calculated. Then, in step (2), the pitch amount P is calculated by calculating the difference between the average value of the front wheel side vehicle height and the average value of the rear wheel side vehicle height.

Next, in step (2), it is determined whether the pinch amount P is within a predetermined range U. In this case, when the vehicle is in a pitching state, the pinch amount P is large, so the process returns to step (2) and steps (2) to (2) are repeated again. Then, just before the pitching state ends, the pinch amount P
becomes smaller and P≦U, so the transition is made from step (2) to step [phase]. In step [phase], it is determined whether P≦U continues for a predetermined time, and if it continues for a predetermined time, the process moves to step [phase] and the damping force control registers 54a to 54d are reset. to end the interrupt processing.

When each register is reset, each control signal C3a-C3d outputted from the control device 50 has a logical value of "0", so that the excitation current from each drive circuit 31 is cut off. As a result, the variable damping force absorber 138-1
The damping force of 3d is reduced and the state returns to its original state.

Also, if the pitching motion is repeated continuously,
Return from step ■ to step ■, repeat steps ■ to step ■ until the pitching operation is completed, and at the end of the turn, move from step ■ to step [phase], then move to step [phase] to reset each register. ,
Ends interrupt processing.

Note that the above embodiment merely shows one embodiment of the present invention, and the variable damping force shock absorber 13a
The configurations 13d to 13d are not limited to the above example, and it goes without saying that any other shock absorber capable of changing the damping force may be applied. Similarly, the torsional rigidity variable stabilizers 14f and 14r are not limited to the above example.

Other stabilizers capable of varying torsional rigidity can be used.

Further, in the above embodiment, the variable damping force shock absorber 13 is used as a suppressing means for suppressing the rolling state of the vehicle.
8 to 13d and torsional rigidity variable stabilizers 14f, 14
Although the case where both r are used has been described, it is also possible to omit either one of them, and furthermore, the variable damping force shock absorbers 13a, 13b on the front wheel side or the rear wheel side are used.
or 13c, 13d and torsional rigidity variable stabilizer 14
Either f or 14r may be omitted.

Furthermore, it is not limited to the case where both rolling suppression and pitching suppression are performed, and either one of these may be performed.

Further, the vehicle rocking state detection means is not limited to the above example, and a vehicle height detector using ultrasonic waves, a vehicle rocking acceleration detector, or other detectors can be applied.

〔Effect of the invention〕

As explained above, according to the present invention, there is provided a suppressing means for suppressing rolling or pitching of the vehicle, which is attached to at least one of the front wheels or the rear wheels, a vehicle state detecting means for detecting the vehicle state, and a vehicle state detecting means for detecting the vehicle state. A vehicle comprising a control means for activating the suppressing means based on a detection signal from the means, a vehicle rocking state detecting means for detecting a vehicle rocking state due to rolling or pitching of the vehicle, and a vehicle rocking state detecting means for detecting a vehicle rocking state due to rolling or pitching of the vehicle; A determining means for detecting a roll angle or a pinch angle of a vehicle or a displacement amount corresponding thereto based on a detection signal, and determining whether the detected value continues to be within a predetermined range for a predetermined period of time; The present invention is configured to include an operation canceling means for canceling the operation of the suppressing means by the control means based on the determination result. Therefore, when the vehicle is in a vehicle shaking state that causes rolling or pitching, and the suppressing means is activated to suppress this,
When the vehicle shaking state is detected and the vehicle shaking state is converged, the operating state of the suppressing means can be released, so that the operating state of the suppressing means can be adjusted according to the vehicle shaking state. The effect can be obtained that the adjustment can be made to a sufficient optimum time and that riding comfort and running stability can be ensured.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional example, FIG. 2 is a block diagram showing the basic structure of the present invention, FIG. 3 is a schematic block diagram showing an embodiment of the present invention, and FIG. 4 is a block diagram showing the basic structure of the present invention. 5 is a block diagram showing a vehicle rocking state detection means; FIG. 6 is a sectional view showing an example of a variable torsional rigidity stabilizer; FIG. A block diagram showing an example of the control device, and FIGS. 8 and 9 are flowcharts for explaining the operation of the control device. 1... Vehicle speed detector, 2... Steering angle detector, 3... Throttle opening detector, 4...
...Stop lamp switch, 5...Inhibitor switch, 6.Old...Vehicle condition detection means, 13a~
13d... Variable damping force shock absorber, 1
4f, 14r... Torsional rigidity variable stabilizer,
31... Drive circuit, 35... Vehicle height detector, 45... Drive circuit, 5o... Control device. Patent Applicant Nissan Motor Co., Ltd. Representative Patent Attorney Tetsuya Mori Patent Attorney Yoshiaki Inner Patent Attorney Shimizu Masaru Representative Patent Attorney Kajiyama Bezere Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] A suppressing means for suppressing rolling or pitching of the vehicle, which is attached to at least one of the front wheels or the rear wheels, a vehicle state detecting means for detecting a vehicle state, and the suppressing means is actuated based on a detection signal from the vehicle state detecting means. a vehicle rocking state detection means for detecting a vehicle rocking state due to rolling or pitching of the vehicle; and a vehicle roll angle or pitch angle or a determining means for detecting displacement amounts corresponding to these and determining whether or not the detected value continues to be within a predetermined range for a predetermined period of time; 1. A suspension system for a vehicle, comprising a deactivation means for deactivating the suspension.