DE2911768C2 - Adjustable shock absorbers, in particular for motor vehicles - Google Patents

Description

a) The control slide (23) is arranged in the axial direction on an "armature (21), which is in a electric coil (20) immersed within the longitudinal bore (19) in the upper part of the Piston rod (13) is arranged and an electrical supply line (32) from outside of the shock absorber (1) !:

b) the cylinder (2) has at least one permanent magnet (36, 39) at its upper end:

c) on the cylindrical inner wall of the pot (34) is arranged in the axial direction at least one w coil (35, 38), which also has a Has feed line (37) from outside the shock absorber.

2. Adjustable shock absorber narh claim I. «5 characterized in that ι 'r permanent magnet is at least one ring magnet (36,39,42,43). the on Cylinder (2) is arranged.

J. Adjustable shock absorber according to claim I. characterized in that the permanent magnets (42, 43) are mutually offset in order to produce a direction-dependent, phase-shifted electrical signal generate and that on the cylindrical inner wall of the pot (34) in the axial direction two coils (41) are arranged, each having a feed line (44, 45) from outside the shock absorber (1).

4. Adjustable shock absorber according to claim 1, characterized in that the coil (38) on the cylindrical inner wall of the pot consists only of a single turn and in the area of the The bottom of the pot is arranged.

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The invention relates to a controllable shock absorber, in particular for motor vehicles, consisting of a cylinder filled with a damping liquid and with a cylindrical pot that extends over the cylinder and carries a piston rod centrally and axially inside the cylinder, which plunges into the cylinder and which at its end one against the cylinder wall carries sealed disc, which divides the cylinder space into two chamber halves and having the direction-dependent high and low pressure valves, having a movably arranged in an axial ^ bore of the piston rod, spring-loaded in the axial direction of the control slide, of an additional passage opening in the rest position / operative position between the two Chamber halves closes.

A large number of shock absorbers have become known, some of which are also continuously adjustable or adjustable shock absorbers are known. DE-OS 15 05 497 includes, for example, a continuously adjustable Shock absorbers, in particular for motor vehicles, consisting of one filled with damping fluid Cylinder, a hollow piston rod which is arranged displaceably therein and has a hollow piston rod under it Control means and a working piston with two groups of axially extending in it Liquid passage channels are provided, each group of which is preferably on the outlet side through their inner circumference fesi on the piston clamped valve spring plates is covered, with at least one The valve plate assembly is supported by a support piston resting on its outer circumference with contact pressure which can be regulated by the control means control means penetrating hollow piston rod acts directly on the support piston, whereby the contact pressure of the support piston is regulated independently of the hydraulic conditions prevailing in the damper can be. However, the design used here to control the shock absorber is not very effective. Because the damping influences are superimposed anyway. thereby providing an accurate and perfect step k * e damping isolation is not possible.

In another known adjustable shock absorber of this type according to the German patent application B 81 235 11/63 c and B 82 476 11/63 c the control of the valve spring plate (s) takes place adjacent support piston for the purpose of changing the damper setting via a hollow in the Adjusting rod arranged on the piston rod, through which throttle openings leading to the support piston more or less wide open and due to the resulting hydraulic flow pressure or Back pressure the support piston can be regulated with regard to their contact pressure on the Ventilfederplatie. the The support pistons are regulated here as a function of the hydraulic forces prevailing in the damper Ratios Such a control of the damping resistance also leads to superimposition of the Damping effects. The damping caused by the different placement of the valve spring plates clamped on the working piston wi d. superimposed the contact pressure of the support piston or pistons, which depends on the respective dynamic pressure conditions. This results in greater inaccuracies. the for today's automotive engineering can no longer be tolerated. Furthermore, the use of the support piston in part.

The DE-OS I6 55M7 is also a adjustable hydraulic telescopic shock absorber, especially for motor vehicles, has become known with a control element located outside the damping body via a transverse and / or an axial one Bore in a piston rod is in communication. Inside a .Steuerraumes, which by a cylindrical widening of the axial bore at the end of the Piston rod is formed, a control sleeve and a control piston between spring elements and a Arranged stop. This arrangement works, like the ones previously mentioned, purely hydraulically. For controlling or regulation of the shock absorber must therefore disadvantageously from the outside an additional hydraulic medium

are fed. For this purpose, additional units must be made available outside, such. B. to Pressure generation, which makes an additional effort that is no longer justifiable today.

Furthermore, a wheel suspension for land vehicles has become known through DE-OS 24 41 172, wherein between the carrier and the body a hydraulic damping device, a displacement converter and an acceleration converter on the Vehicle body are arranged. The displacement transducer generates a first signal that is the position of the wheel carrier opposite the body, the acceleration converter on the vehicle body generates a second signal which corresponds to the vertical component of the acceleration of the body corresponds to the wheel. Furthermore, there is a control device which is used to change the damping force of the damping device in accordance with the first and the second signal can be set in function, so that the second signal of the acceleration converter to assume a setpoint as a function of the first signal. To this end, the control device a function generator to which the first signal is fed at an output terminal; and which generates an output signal which corresponds to a desired value of the second signal, wherein a comparator is provided. the attenuator according to the error between the second signal and controls the output signal from the function generator

A disadvantage of this hydraulic damping device is. that the two signals must be picked up by different attenuators and the control signal is in turn fed to two different damping devices.

The invention is therefore based on the object. a shock absorber of the type mentioned above Create, the damping characteristics of which can also be controlled electrically. being all for scheme or Control necessary parts within the shock absorber - except for an electronic amplifier Or an electronic signal transmitter - integrated disordered st.η should.

The solution to this problem is characterized according to the invention by the following features:

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·) The control slide (23) is arranged in the axial direction on an armature (21) which is immersed in an electrical coil (20). Jie is arranged inside the longitudinal bore (19) in the upper part of the piston rod (13) and which has an electrical feed (32) from outside the shock absorber (1):
b) the cylinder (2) points at its upper end

at least one permanent magnet (36,39);
C) on the cylindrical inner wall of the pot (34) '5 at least one coil (36, 38) is arranged in the axial direction, which also has a feed (37) from outside the shock absorber.

Further advantageous embodiments of the invention are characterized in the subclaims.

The shock absorber according to the invention has the advantage that it acts on the shock absorber from the outside applicable control signals or switching pulses in his Damping characteristics changed and can throw adapted to the respective conditions. In advantageous All units necessary for control or regulation are wise - except of course possibly necessary electronic amplifier or an electronic signal transmitter - within the Integrated shock absorber, which can still retain the same dimensions as known Prior art shock absorbers.

Advantageously, the coil within the shock absorber according to the invention can be over the outer Supply line control signals or control pulses or control pulses are fed so that accordingly these impulses the armature more or less dips into the coil and thereby the one with the armature fixed control slide the lower opening of the longitudinal bore within the piston rod more or releases less. By releasing the longitudinal tread an additional connection between the lower chamber half and the upper chamber half of the cylinder created by circumventing the known Valves within a shock absorber. This longitudinal bore of the piston rod in cooperation the transverse bore penetrating the longitudinal bore thus represent a bypass through the Control slide controlled or generally lockable and is evident. The bypass can either be open or closed in unloaded operation.

The invention advantageously provides a fully adjustable or controllable telescopic shock absorber available Because inside the coil or the coils of the pot are through the or the ring magnets of the cylinder with alternating loads on the telescopic shock absorber one or more Stresses induced, over which all data to adapt the damping properties to the respective Condition of the shock absorber can be derived. These data are amplitude, slope, acceleration. Frequency and direction. This data can be evaluated in a computer that in turn generates an output signal corresponding to the respective state of the telescopic shock absorber, which is fed as a control signal to the coil inside the piston rod of the shock absorber.

Furthermore, the telescopic shock absorber according to the invention be filtered as a controller with special properties, in which this the output signal the coil inside the pot after amplification and analysis again as the input signal for the coil is supplied within the piston rod.

In particular, it is with the telescopic shock absorber according to the invention possible, this according to the originating from the encoder system pot coil - cylinder magnet Regulate signal. Therefore, the telescopic shock absorber according to the invention can practically immediately respond to every type of ground or every driving behavior and accordingly his Correct or support characteristics for optimal driving behavior.

Furthermore, the shock absorber according to the invention, as well as the telescopic shock absorber according to the invention, can be provided with a switch which 7. B. only switches the bypass inside the piston rod on or off when the vehicle is under load. As a result, in the simplest embodiment of the shock absorber according to the invention, a shock absorber can be obtained for two driving modes, namely for load operation and for normal operation.

Furthermore, it is possible within the pot, a coil with z. B. to provide only a single turn, which serves as a dwarf and which is huge is arranged in or on the end of the pot.

Then there is a signal via this limit switch (! (■ give, the telescopic shock absorber is switched to harder operation.

Three examples of the invention are shown in the drawing and described below. It shows

1 shows a cross section through an entire shock absorber to illustrate the cylinder, the pot, the control spool and the armature omitting the permanent magnet on the cylinder and the coil on the Pot.

Fig. 2 shows a section along the line AA in F ig. I to show the cross hole inside the piston rod,

Fig. 3 shows an example of a shock absorber according to the invention, with the piston rod and the cylinder according to FIG. I can be designed.

Fig. 4 shows another example of a Shock absorber, with the coil in the pot only having a single turn and serving as a limit indicator and

F i g. 5 shows another example of a shock absorber according to the invention, each with two coils and two Permanent magnets for directional discrimination of the same.

In the figures, the same parts are identified by the same reference symbols.

According to FIGS. 1 and 2, the adjustable shock absorber 1 consists of a lower, cylindrical part 2. which is filled with a damping liquid and an upper, cylindrical pot part 3, which the Cylinder 2 overlaps. At the upper end of the pot part 3 as at the lower end of the cylinder 2 are each one Bracket 4, 5 arranged for fastening the shock absorber 1 on the one hand to the body and on the other hand on the wheel or on the wheel axle.

A hollow piston rod 13 is / entrisch arranged within the pot 3, which thus has a through hole 19. The piston rod 13 is guided centrally and sealed within a cover 17, the cover 17 closing the cylinder 2. A ring seal 18 seals the cover 17 against the piston rod 13. At the lower end of the piston rod 13, which is immersed in the cylinder 2, there is a disk 8, which is firmly connected to the piston rod 13. This disk 8 is slidably arranged within the cylinder 2 and is suitably sealed with respect to the cylinder wall. In the example shown in FIG. 1, the disk 8 is securely held by means of an intermediate disk 16 and a nut 15, which is screwed onto the lower end of the piston rod 13. The disk 8 also has a set of springs II, 12 on each of its two flat hinge surfaces, which through-bores 9 and 10 cover within the disk 8. The springs can, for example, have different spring values, whereby the disk 8 represents a high pressure and low pressure valve. The pot together with the piston rod and the disk attached to it is now relatively movable with respect to the cylinder. The plate 8 thus divides the cylinder space into two chamber halves 6 and 7, which are provided on the valve bores 9, 10 with each other in conjunction ^h.

In the upper part of the piston rod 13, a coil is now arranged in the longitudinal direction, which is in its interior an anchor 21 receives the lower end of the anchor has a conical taper, which in a " The lower end of the coil 20 arranged conical holding part 22 engages End position of the armature 21 created.

The armature 21 is blind at its lower, tapered end with a control slide 2 \ \, which also extends within the inner bore 19 of the piston rod 13. This longitudinal bore 19 is a Sackbohmng in the example shown here. a through hole 31 being guided centrally through the lower end. The diameter of this through hole 31 is smaller than that of the l.iingsbohriing 19. Furthermore, a transverse bore 30 is guided through the piston rod transversely to this longitudinal bore 31, whereby this transverse bore 30 is thus in the area of the upper chamber half 7 of the cylinder 2. The control slide 21 now dips into the through hole 31. the sleeve fitting into the through hole. The control slide 23 is further pretensioned by a compression spring 24, which is supported on the one hand on the end wall 26 of the sack hole 19 and on the other hand on a holding part 25 firmly connected to the control slide 23. The holding part 25 can /. B. be a nut or a cross pin. The control slide 23 and the armature i \ are thus pressed into a defined position by the compression spring 24, in which in FIG. example shown above.

The coil 20 also has an outwardly leading supply line 32 on. this lead is insulated within the shock absorber. Further the shock absorber can have a ground connection 33.

The control slide 23 also has on his lower end a longitudinal bore 27 running in the axial direction, which in the region of the longitudinal bore 19 or the Sackbohmng is penetrated by a transverse bore 28, 29. This makes the entire interior of the Piston rod 13 filled with the damping fluid, which is always under the same pressure prevails within the upper chamber half 7. As a result, the armature takes 21 together with the control slide 23 always a defined position. this location not being due to different pressures within the system being affected.

The mode of operation of the shock absorber shown is as follows:

In the rest position of the armature 21 and the control slide 23, the shock absorber works like a ordinary shock absorber. The bypass. formed by the through hole 31 and the transverse hole 30 inside the piston rod 13 is either closed or open: in the example shown here is the Bypass open when in rest position. In this case, the damping of this shock absorber is soft set.

If a current is now sent through the coil 20 via the supply line λ2, the armature 21 is completely drawn into the coil 20 due to the magnetic field, whereby the lower end of the control slide 23 moves into the through-hole 31 and blocks the cross-hole 30 running to it. As a result, the bypass can be closed suddenly, whereby the damping characteristics of the shock absorber can be changed suddenly. In the example shown here, the shock absorber 1 is switched to "hard" operation.

F i g. 2 shows a side view of the piston rod 13, the disk 8 being shown in a partial section. From Fig. 2 shows the course of the transverse bore 30 transversely to the through bore 31. The cross hole 30 is designed here as an elongated slot 3 now shows an example of an inventive

Lien shock absorber, the cylinder and the Piston rod together with control slide, armature and coil according to the description of Γ i g. I be designed can. The shock absorber of FIG. J therefore consists of a cylinder 2 with one arranged above it cylindrical pot 34. which overlaps the cylinder 2 downwards. This pot 34 points on its inner wall an axially aligned spool 35. where this coil »for example consists of a single turn can exist. This coil 35 has a lead 37 which leads to the outside and which is inside the pot is performed in isolation.

The cylinder 2 has at its upper tinde in or a permanent magnet 36 on the manicl wall, which can advantageously be an annular permanent magnet. Thus, through the coil 35 inside the pot and the permanent magnet 36 on the cylinder, an electrical Encoder system formed. The remaining parts of the telescopic shock absorber correspond to those in Fig. I. to the is weighed.

If the I opt J4 now moves relative to cylinder 2, so As a result of this movement, a voltage is induced within the coil 35, which via the lead 37 in an electronic evaluation, not shown, can be given. Likewise, a can from The control signal originating from this evaluation is fed to the feed 32 and thus to the coil 20 be given within the piston rod 13 to change the position of the control slide.

F i g. 4 shows an embodiment of a telescopic shock absorber according to the invention, wherein in the pot a coil 38 is arranged in the area of its bottom. which only consists of a single turn. Of the The cylinder carries a permanent magnet 39 at its upper end inside the pot, which is also here is preferably a ring magnet. The rest of the design of the telescopic shock absorber corresponds to that in Fi g. 1. why reference is made to this.

If the cylinder moves so far into the pot that the limit indicator, formed by the system Coil 38 - permanent magnet 39. emits a signal, the telescopic shock absorber is controlled harder.

Fig. 5 shows a further embodiment of a telescopic shock absorber according to the invention, a directional discrimination of the movement of the shock absorber also taking place here. Inside the pot is z. B. a bifilar wound double coil 41 is arranged. This double coil 41 has two outward feed lines 44 and 45 for its two winding layers. At its upper end, the cylinder has two permanent magnets 42, 43, which are preferably designed as ring magnets. These two permanent magnets 42, 43 have with respect to their distance from one another z. B. a division by 1.5 times the winding distance of the double coil 41, so that the two signals received from the double coil 41 have a phase shift of 90 ° . In this way, in addition / u the other data, such as speed. Acceleration. Frequency can also be discriminated against the direction of movement. The reference number 46 denotes the mass connection of the telescopic shock absorber. Otherwise, the telescopic shock absorber corresponds to the design according to FIGS. I and 3, which is why reference is made to this.

List of reference numbers

1 Shock absorbers 2 cylinder 3 cylindrical pot 4.5 Brackets 6th lower chamber half c 7th upper half of the chamber 8th disc 9, 10 Valve bores II. 12 Valve springs 13th Piston rod 14th End part of the piston rod 15th mother 16 Index washer 17th Cylinder cover 18th Ring seal 19th L. longitudinal drilling inside the piston rod 20th Kitchen sink 21 anchor 22nd conical hatchet 23 Control spool 24 Compression spring 25th Counter-halation of the spring 26th Front wall 27 Länysbohrung within the end of the Control slide 28.29 Cross bores within the control slide over 23 to the longitudinal bore 27 30th Cross hole inside the piston rod to the through hole 31 within the Piston rod 31 Through hole 32 electrical feed to coil 20 33 Ground connection 34 cylindrical pot 35 Kitchen sink 36 ring-shaped permanent magnet 37 Feed to spool 35 38 Coil consisting of a single win manure 39 Permanent magnet 40 Coil feed line 41 Double coil 42.43 Permanent magnets 44.45 Feed lines of the double coil 41 46 Ground connection

For this purpose 3 sheets of drawings

Claims (1)

Patent claims: I. Adjustable shock absorber, especially for motor vehicles, consisting of one with a Cylinder filled with damping fluid and with a cylindrical one that extends over the cylinder Pot, which carries a piston rod axially and axially on the inside, which dips into the cylinder and which on its end carries a disk sealed against the cylinder wall, which divides the cylinder space in two Divides chamber halves and has the directional high and low pressure valves, with one in an axial bore of the piston rod movably arranged, in the axial direction spring-loaded control slide, which in the rest position / working position ment closes an additional passage opening between the two halves of the chamber, characterized by the following features: