DE102008045493B4 - Vehicle vibration damping system with additional suspension element - Google Patents

Abstract

Vehicle vibration damping system having at least two vehicle parts (1, 2) which are oscillatable relative to one another by means of at least one first suspension element (9, 20, 22),
With
at least one second suspension element (10, 19, 21), on which an inertia element (12, 12a, 12b) acts whose inertial force at occurring vibration movements of at least one of the vehicle parts (1, 2) on an actuating unit (14, 14a, 14b; 15, 16) for continuously readjusting at least one spring-related parameter of the second suspension element (10, 19, 21) for changing a vibration transmission function,
characterized in that
the first suspension element is a gas spring (20) or a mechanical spring (9, 22) which is arranged between the vehicle parts (1, 2) or between a vehicle part (1, 2) and at least one between the vehicle parts (1, 2,) Connecting element (3, 4) is arranged.

Description

The invention relates to a vehicle vibration damping system with at least two vehicle parts, which are movable relative to each other by means of at least one suspension element, according to the preamble of claim 1.

Conventionally, in the vehicle area, two mutually swinging vehicle parts, such as a seat portion of a vehicle seat, which is resiliently disposed relative to a vehicle seat bottom, a suspension element and an additional damping element in the form of a damper to take energy from the suspension system and dampen the spring movement, if in the case of resonance strong deflections of this spring-oscillating system are caused.

Such a damper may be configured differently in its construction. For example, hydraulic dampers essentially consist of a piston guided on a piston rod in an oil-filled cylinder. With axial movement of the piston rod and thus of the piston relative to the cylinder, the oil must flow through narrow channels and valves in the piston. Due to the resistance, which is given to the oil thereby, pressure differences are generated, which generate the damping forces via effective surfaces. With increasing speed of the piston movement, the flow resistance and thus the damping effect increases, whereby within certain limits this characteristic can be influenced in a targeted manner.

There are also known mechanical shock absorbers. These consist in principle of spring-loaded friction surfaces. The layered leaf springs have multiple spring elements and are combined spring / damper units. The deflection of the spring absorbs the shock and stores it in the spring. The friction between the individual spring leaves dampens the vibration and converts part of the spring forces into heat.

The publication DE 42 23 786 A1 discloses a vibration sensor for a system for vibration isolation of large mass objects, such as machines, units or buildings, consisting of a partially filled with a viscous or viscoelastic medium damper housing which dips a damper stamp which is at least indirectly connected to the system to be isolated a between elastic damper and mass to be damped interposed elastic element is provided and the mass of the damper temple is increased by an additional mass beyond its necessary for its static and dynamic strength due to the material used mass and / or the damper housing via an intermediate elastic element on its base is supported.

Likewise, air spring damper are known in which the medium air can take over both spring and damper tasks.

Frequently, such an arrangement of a damper, for example in a vehicle seat or between a driver's cab and a vehicle base frame, requires a complex construction in order to obtain optimum damping of differently directed and differently strong vibrations. It is necessary to take into account a precise balance between the damping and suspension characteristics which are intended, for example, to allow a seating comfort range within a suspension-force characteristic of a swinging vehicle seat. Moreover, these damper systems have the disadvantage that they reduce the vibration reduction in the subcritical and supercritical region and thus worsen the vibration comfort.

It is therefore an object of the invention to provide a vehicle vibration damping system with improved vibration comfort, which has at least two vehicle parts, which are oscillating relative to each other by means of at least one suspension element, wherein in such a system, the arrangement of one or more dampers in dependence It is not necessary to design the system presented here, or it is possible to resort to dampers with low power dissipation in order to minimize the negative influence of the damper in the over- and under-critical suspension area as far as possible.

This object is achieved according to the features of claim 1.

It is an essential point of the invention that, in a vehicle vibration damping system having at least two vehicle parts, which are oscillating relative to each other by means of at least one first suspension element, at least one second suspension element is present on which acts an inertial element, the inertial force of at least one vibration movements occurring the vehicle parts acts on an adjusting unit for the continuous readjustment of at least one spring-relevant parameter of the second suspension element for changing a vibration transmission function. Thus, instead of a damper, as has hitherto been the case, a suitable arrangement of an inertia element in conjunction with the second suspension element can be used, whereby at least a suspension element parameter can be changed continuously in such a way that the suspension-relevant parameter counteracts by the introduced on the vibration damping system vibration and the resulting force on the suspension element and effectively reduces the introduced vibration in all areas (also over- and subcritical). With a certain arrangement of the inertia element, it is possible to completely dispense with conventional dampers.

The first suspension element can be both a gas spring and a mechanical spring, which is preferably arranged between the vehicle parts or between one of the vehicle parts and a connecting element arranged between the vehicle parts. The advantage here is that the gas spring (air cushion) can work without compressed air and only with ambient air (atmospheric air).

The first suspension element is preferably used for pre-setting a fixed level between the first vehicle part and the second vehicle part, wherein the first vehicle part may be a vehicle seat top and the second vehicle part may be a vehicle seat bottom.

For example, in the case of a mechanical design of the second suspension element, the inertia element may be connected to the suspension element as an inertial mass by means of a lever mechanism such that upon deflection of one of the vehicle parts and thus upon a change in the tensioning force of the suspension element, which may be a torsion spring, one of the Can be connected vehicle seat parts, the inertial mass, which is moved only delayed due to their inertia, the suspension element acted upon by a modified spring biasing force and thus a different suspension effect of the second suspension element is achieved. It can thereby even be achieved that the instantaneous position of the inertia element, which is determined by an acceleration movement of one of the vehicle parts on which the inertia element is pivotally mounted, sets the lever mechanism in relation to the suspension element such that the resulting change in the Spring force against the acceleration movement of the introduced vibration acts. This has the consequence that a vibration amplitude of the entire vehicle vibration system occurring with the introduced vibration is reduced and thus damped.

The torsion spring element is detachably connected (disconnectable) with one of the vehicle parts, such as a rocker. This connection (connection) or release (switch off) can be done by a control unit. The control unit may be controlled by a vibration path or by way of the inertia element by means of an inertial sensor. The suspension of the vehicle parts can be set to a certain level (rest position) initially. In this position, the additional spring element is connected to the rocker (connection). With excited vibrations, the suspension comes to a shift from this rest position. With this shift, the additional spring element is tensioned, so that a force is created, which acts opposite to vibration movement. With large deflections, especially in the resonance range, a force becomes counterproductive because stored energy increases the vibrations. Thanks to the control unit connected to the inertia element, the connection to the rocker is released when certain acceleration values are reached, whereupon the spring element relaxes and thereby energy is discharged from the system.

The first suspension element can be a mechanically functioning compression spring which serves as a vibration element between the two vehicle parts, also for the initial setting of a predeterminable level of a vehicle seat or an initial weight adjustment. The second suspension element can be a torsion spring, which itself constitutes a type of spring regulator or is connected to such a spring regulator which, with a corresponding deflection of the inertia element and at the same time initiated oscillation, which can act on the torsion spring via one end, the suspension element Torsion spring can relax.

The inertia element can be connected as a mass element directly or by means of a lever mechanism, ideally a single lever, with the spring regulator or the torsion spring. At a certain position of the inertia element, the spring regulator is then actuated and the additional spring is released. This can be done by the inertia element with a certain delay in an initiated vibration on the vehicle parts only then acts on the spring controller when it is correspondingly strongly deflected by a correspondingly strong acting vibration. This leads to a dissipation of energy from the suspension system.

Instead of a mechanically formed second suspension element can also be a valve assembly which is connected to the inertia or the (s) used to be used with appropriate deflection of the torsion element, which is caused by vibrations introduced to the vehicle parts, the supply and exhaust air and by a gas spring, which is the second suspension element to regulate or less strong or stronger.

Ideally, it can be achieved by such a system that the inertia element always moves in the opposite direction to the externally introduced oscillatory motion in the vehicle vibration damping system or is positioned oppositely to effect a spring-damping effect.

In order to determine the size of the spring-relevant parameter to be newly set, at least one acceleration value or a speed value of the inertia element is determined when vibration movements occur.

Alternatively or additionally, at least one distance covered by the inertia element can be determined when oscillation movements occur in order to determine the suspension-relevant parameter to be newly set.

As already mentioned, the two vehicle parts may be a vehicle seat bottom part and a vehicle seat top part, on which a seat surface with a backrest is arranged. Likewise, a vehicle base frame and a sprung gear train and / or a vehicle cabin and a vehicle base frame are conceivable as vehicle parts. This makes it clear that the vehicle vibration damping system according to the invention is applicable both to vehicle seats and to vehicle cabs, as are known for example in tractors, or to the suspension of vehicles.

If the second suspension element is a torsion spring, one end thereof is preferably connected to one end of a scissor arm of a scissor frame arranged between the vehicle seat upper part and the vehicle seat bottom part. The same end of the torsion spring can also be connected to the inertia element, which is designed to be pivotable.

If a gas spring is used as the second suspension element, it may be arranged as part of the second spring element between a arranged scissors frame and the vehicle upper part or vehicle lower part.

The inertia element is preferably the mass element, which is provided with a predeterminable mass, that is to say can also be changed in its inertia by changing a weight or by changing a lever arm, to which the inertia element is fastened, in order to achieve optimum vibration damping behavior Vehicle vibration damping system to obtain. As a result, it can be avoided, for example, that the second suspension element is deflected to the stops when an extremely strong vibration is introduced into the vibration damping system from outside.

When using the valve arrangement as an actuating unit for changing the gas pressure occurring in the spring element designed as a gas spring, the cross section of at least one gas supply and discharge line of the gas spring is prevented as a function of the movement of the inertia element. This makes it possible to use, for example, an air spring as the suspension element, whose internal pressure in the end regions of the air spring can be set to different degrees by influencing the valve arrangement by means of the inertial mass. For example, in a strong deflection of the suspension element by an externally introduced vibration, the inertia element may be arranged due to its inertia in a position which allows the valve assembly to be adjusted, for example by means of a lever so that thereby the cross section of the gas supply is increased and amplified Gas or air is introduced into the air spring to counteract the strong vibration movement.

Further advantageous embodiments will become apparent from the dependent claims.

Advantages and expediencies can be found in the following description in connection with the drawing. Hereby show:

1 in a schematic representation of a detail of a vehicle seat with a vehicle vibration damping system according to a first embodiment of the invention,

2 in a schematic representation of a detail of a vehicle seat with a vehicle vibration damping system according to a second embodiment of the invention and

3 in a schematic representation of a detail of a vehicle seat with a vehicle vibration damping system according to a third embodiment of the invention.

In 1 is a schematic representation of a detail of a vehicle seat with the vehicle vibration damping system according to a first embodiment of the invention shown. A vehicle seat shell 1 is with a vehicle seat base 2 by means of a scissors rack 3 . 4 and it attached plain bearings 5 . 6 as well as fixed camps 7 . 8th connected so that it can swing up and down.

One between the vehicle seat top 1 and the vehicle seat bottom 2 arranged mechanical compression spring 9 serves to perform an initial level and / or weight adjustment with respect to the weight of the driver using the seat and as an additional vibration element between the two vehicle parts 1 . 2 to act.

An additionally arranged torsion spring 10 is - as by means of the double arrow 11 shown - is connected to an additional spring controller not shown here as a control unit, which serves, with appropriate deflection of an inertial mass 12 . 12a . 12b to initiate a relaxation process of the torsion spring. The inertial mass 12 thus serves as acceleration-sensitive weight, which at the initiation of the vibrations, as for example in the case of passing through a pothole by introducing the resulting vibrations on the vehicle seat base 2 can arise, acts on a resulting acceleration and with a certain time delay undergoes a correspondingly strong deflection, as indicated by the double arrow 13 is reproduced.

This is the inertia element 12 , which with the reference signs 12a and 12b is shown in different deflections, by means of a lever 14 with one end of the torsion spring 10 , at least indirectly, connected. The reference numerals 14a and 14b show different positions of the lever 14 ,

With the same end of the torsion spring 10 is also a scissor arm 4 of the scissors rack 3 . 4 connected, so that a corresponding change in the position of the scissor arm 4 based on the spring force of the torsion spring 10 acts, as with a certain time delay, a deflection of the inertial element 12 causes. Such a position of the scissor arm 4 is caused by, for example, an initiated from below vibration on the vehicle seat base 2 reached.

The torsion spring and possibly an interaction of the spring regulator are about a rotation axis 15 rotatably arranged.

A spring regulator may be configured to relax the torsion spring 10 causes, if this is in a compensation range whose Ausgleichsbereichsgrenzen is set in the central region of a spring travel of the torsion spring. Thus, the torsion spring is relaxed in this compensation area, whereas outside this compensation range, the torsion spring can act as an additional vibration element.

If an initiated oscillation and thus an acceleration acting on the vehicle parts take place, their strength determines the position of the inertial mass 12 , which in turn regulates the action of the spring regulator. This results from the different stress state of the torsion spring 10 a reduction of the spring force and thus influencing a suspension parameter. This reduced spring force acts against the initiated acceleration, which leads to a reduction of the vibration amplitude of the oscillating vehicle seat.

In the 2 is a schematic representation of a detail of a vehicle seat with a vehicle vibration damping system according to a second embodiment of the invention shown.

Identical and equivalent parts are provided with the same reference numerals.

A valve arrangement 16 is with a supply air line 18 , on the example, ambient air can be sucked, and an exhaust duct 17 that connects to a gas spring 19 as a second suspension element manufactures connected. The valve assembly also has an inertial mass suspended therefrom 12 out, in different positions 12a and 12b is reproduced and along the double arrow 13 is pivotable.

The inertial mass 12 is by means of a lever 14 who works in different positions 14a and 14b is reproduced, with a fulcrum 15 connected to the valve assembly, via which an adjustment of the valve assembly can be achieved.

A first suspension element 20 is primarily used for level and / or weight adjustment, which takes place when occupying the vehicle seat and is between the scissor arm 3 and the vehicle seat bottom 2 arranged. In contrast, the first suspension element, namely the gas spring 19 , between the scissor arm 4 and the vehicle seat upper 1 arranged.

Again the inertial mass reacts 12 on accelerations caused by vibrations introduced on the vehicle seat base 2 and the vehicle seat shell 1 act, react.

By introducing a vibration can with a certain time delay, the position of the inertial mass 12 be changed, which leads to a change in the cross section of the valve assembly. This leads to a reduction of the vibration amplitude of the vehicle seat in vibration.

In 3 is a schematic representation of a detail of a vehicle seat with a vehicle vibration damping system according to a third embodiment of the invention shown. Identical and equivalent components are provided with the same reference numerals.

In the 3 reproduced third embodiment is different from that in 2 illustrated second embodiment of the invention in that instead of a further gas spring as the first suspension element is a mechanically acting spring 22 between the vehicle seat base 2 and the vehicle seat upper 1 is connected. The second embodiment is intended for vehicles with existing compressed air. The air suspension is already integrated in the vehicle and it is still a gas spring installed. On the other hand, the third embodiment works as well as the first embodiment without compressed air.

The advantage here is that the gas spring (air cushion) can work without compressed air and only with ambient air (atmospheric air). When there is no acceleration or acceleration up, the valve is opened and the gas spring does not produce a spring action. With an acceleration downwards, the valve is locked, thereby creating an additional spring action against the acceleration. The energy stored in the gas spring is derived from the vibration system during acceleration changes.

The first suspension element is again a gas spring 21 used, over a connecting line 17 with a valve assembly 16 responsible for regulating gas supply and discharge. Via an ambient air supply line 18 finds a supply of air to the valve assembly 16 instead of.

By the respective position of the inertial mass 12 becomes the cross section within the valve assembly 16 designed differently to thereby control the gas supply and discharge and thus the gas pressure within the gas spring 21 to effect. Such a gas spring 21 can in turn have a compensation range, which is provided with compensation range limits, which - depending on the system design - in the central region of the spring travel of the gas spring 21 can lie. Within the compensation area, the gas spring acts 21 as a weak damper, whereas outside the counterbalancing area it serves as an additional spring-acting gas spring or oscillating gas spring.

All disclosed in the application documents features are claimed as essential to the invention, provided they are new individually or in combination over the prior art.

LIST OF REFERENCE NUMBERS

1

Vehicle seat shell

2

Vehicle seat bottom

3, 4

scissors-type frame

4a

End of the scissor arm

5, 6

bearings

7, 8

fixed bearing

9, 22

Mechanical spring

10

torsion spring

11, 13

movement arrows

12, 12a, 12b

inertial mass

14, 14a, 14b

lever

15

axis of rotation

16

valve assembly

17, 18

interconnectors

19, 20, 21

gas spring

Claims (13)

Vehicle vibration damping system with at least two vehicle parts ( 1 . 2 ), which by means of at least one first suspension element ( 9 . 20 . 22 ) are oscillatory relative to each other, with at least one second suspension element ( 10 . 19 . 21 ) to which an inertia element ( 12 . 12a . 12b ), the inertial force of which occurs when oscillatory movements of at least one of the vehicle parts ( 1 . 2 ) to an actuator ( 14 . 14a . 14b ; 15 . 16 ) for the continuous readjustment of at least one spring-relevant parameter of the second suspension element ( 10 . 19 . 21 ) acts to change a vibration transmission function, characterized in that the first suspension element is a gas spring ( 20 ) or a mechanical spring ( 9 . 22 ), which between the vehicle parts ( 1 . 2 ) or between a vehicle part ( 1 . 2 ) and at least one between the vehicle parts ( 1 . 2 ,) arranged connecting element ( 3 . 4 ) is arranged. Vehicle vibration damping system according to claim 1, characterized in that a first vehicle part, a vehicle seat bottom ( 2 ) and a second vehicle part, a vehicle seat upper part ( 1 ) is with seat. Vehicle vibration damping system according to claim 1, characterized in that on the vehicle seat upper part ( 1 ) and / or on the vehicle seat bottom ( 2 ) at least one torsion spring ( 10 ) is arranged as a second suspension element, the first end having one end ( 4a ) of a scissor arm ( 4 ) one between the vehicle seat top ( 1 ) and the vehicle seat bottom ( 2 ) arranged scissors rack ( 3 . 4 ) connected is. Vehicle vibration damping system according to claim 3, characterized in that at the first end of the torsion spring ( 10 ) the inertia element ( 12 . 12a . 12b ) is pivotally mounted. Vehicle vibration damping system according to claim 4, characterized in that the inertia element ( 12 . 12a . 12b ) by means of at least one lever ( 14 . 14a . 14b ) with the first end of the torsion spring ( 10 ) indirectly via a spring regulator for controlling and / or locking the torsion spring ( 10 ) connected is. Vehicle vibration damping system according to claim 2, characterized in that on the vehicle seat upper part ( 1 ) and / or on the vehicle seat bottom ( 2 ) at least one gas spring ( 19 . 21 ) as part of the second suspension element between a scissor arm ( 4 ) one between the vehicle seat top ( 1 ) and the vehicle seat bottom ( 2 ) arranged scissors rack ( 3 . 4 ) and the vehicle seat upper part ( 2 ) or the vehicle seat bottom ( 2 ) is arranged. Vehicle vibration damping system according to claim 6, characterized in that the gas spring ( 19 . 21 ) with a valve arrangement ( 16 ) is connected as an actuating unit, which the gas spring ( 19 . 21 ) and the inertia element ( 12 . 12a . 12b ) for changing a gas spring ( 19 . 21 ) connecting gas pressure, wherein the valve arrangement ( 16 ) a cross section of at least one Gaszu- and -abführleitung ( 17 ) of the gas spring ( 19 . 21 ) in dependence on the movement of the inertia element ( 12 . 12a . 12b ) changed. Vehicle vibration damping system according to one of the preceding claims, characterized in that at least one acceleration value of the inertia element (15) is used to determine the size of the newly relevant spring-relevant parameter. 12 . 12a . 12b ) can be determined at occurring vibration movements. Vehicle vibration damping system according to one of the preceding claims, characterized in that at least one speed value of the inertia element (15) is used to determine the size of the newly relevant spring-relevant parameter. 12 . 12a . 12b ) can be determined at occurring vibration movements. Vehicle vibration damping system according to one of the preceding claims, characterized in that for determining the size of the newly to be adjusted spring-relevant parameter at least one of the inertial element ( 12 . 12a . 12b ) Distance traveled in occurring vibration movements can be determined. Vehicle vibration damping system according to claim 1, characterized in that a first vehicle part is a vehicle base frame and a second vehicle part is a sprung gear train. Vehicle vibration damping system according to claim 1, characterized in that a first vehicle part is a vehicle cabin and a second vehicle part is a vehicle base frame. Vehicle vibration damping system according to one of the preceding claims, characterized in that an inertia element is a mass element ( 12 . 12a . 12b ) with a predeterminable mass.

Images