DE2051858B2 - HYDRAULIC TWO-PIPE TELESCOPIC VIBRATION DAMPER, IN PARTICULAR FOR VEHICLES - Google Patents

Description

pfungsventile _v

as a result of im

draws that the space in which the inside an- JfI * ^^^ aeordinated throttle channels (31) in the valve bottom opening cross-section of the

(21) open through a shutter (22) * ₅ and ^{throttle k} ^.

is covered, which, in "at the center of the site as compensation for ^

for ⁵ ass the control valve (53) parallel connected the ^^^^

Has check valve (50). the piston ^ sc ™

15. Teieskopvibration damper according to the ^ usgle.chs-bw supply ^ aum, _{λ occurs} claims 1, 2, 4 to 7 and 12 to 14th thereby 30 pressure ones Grcgteters. ^ Es ^ P ^ gekennzeichne 'that between the valve bottom also den _n f " ^S _r ^S1 SSt bill.

(21) and the closure flap (22) which the tem- thermal expansion ^^^ S

_P erature, dependent control valve (53) forming B ₁ - Mjg ^^ S ^?

metal disk is clamped. "H" makes sense that the pressure increase

16. Telescopic speed damper after arrival and it leuüjtg a _lifetime r of claim 1 and possibly one or more- ™ «J ^ JJg ¹ ™? _d is characterized, for example, the Dichren of claims 2 to 15, characterized marked ρ ^^. ^^^ _of Rückstroßraumes directly, that the separation tube exposed to 24) specific to sememe f "^^^^ the sealing lips piston end face a constriction (77 Sorter strain This point, with which it rests at the corresponding end of the 4 ° very strong constriction, _bevelling and working cylinder (19), although more than deserved in the case of _{the high} Heri Til d Uf Through-flow slots (28) J ^^^^ gungsdlmpfcn

it is difficult, the damping fluid T ^ s petatur to dominate, so that geJ2J5 _{te Daem fe ^For} cold and hard to stay, while poorly cooled damper in summer are so hot that they partially or completely fail Vu _in winter: the heating of the Damping fluid

'"" ^, ^ r ^ sserter cooling of the damping

J ^ _s g ^ _it ^m ^ _r ^Ve _e ^{r been} _beaten , fluss gkeit v. rges 8 _hrfft

Working cylinder (19) is applied, however, over part of the circumference * through-flow slots (28) remain between the separating tube and the working cylinder, over which the outer annular space (26) with the inner. Annular space (25) in connection stands.

₅ o

The invention relates to a hydraulic twin-tube telescopic vibration damper, msbesonuere for vehicles, consisting of an am
End of a ^ r pistonCange attached, in one with
The working cylinder filled with damping fluid 55
sliding and with at least one through
flow of damping fluid depending on the direction
Controlling damping valve provided working piston and from a cylindrical outer housing, 00 a on the working cylinder κηη-centrically surrounding
that with the working cylinder a nngiormigen Aus ^^
equal space for the displacement of the piston rod
Damping fluid t binds. The Aus S?
the same room with one of the working cylinder
The closed working space at at least one end 65 passes through the flow of the damping flow

774 _is a

ny

be, tan the to

gkicferaun

tnsche

encompassing auspices in two

is divided. Daoei becomes the over end of the work

v. “As the work space

displaced fluid from it to the outer annulus adjacent to the airflow housing, that in this known the workspace ver-Fall, i. H. without back damping

liquid, is passed into the outer annulus, developed to largely independent liquids is limited to a promotion of Dämpfupgs- because the viscosity problem caused by the liquid in the outer annulus only reached with the help of the invention, almost constant-pressure level, so that the throughput of the liquid temperatures to be cooled is omitted. Damping fluid is correspondingly lower. It 5 Another improvement made by the Erfinist It is advantageous if the vibration damper has a cooling effect that can be achieved when it is heated lent quickly reached its operating temperature, in damping fluid is possible that the which he does his job best. In the working piston in a manner known per se, only one in known vibration damper is provided with a damping valve that opens in this way continued increased cooling to achieve io and the attenuation that opens in the pressure stage Operating temperature delayed. As a result of the valve at the piston end of the working height Viscosity of the damping fluid in the room, the temperature-dependent control valve after the warm-up phase works the vibration damper is switched on.

Too high damping force, which dampens the vibration Advantageously within the meaning of the invention he makes seem too harsh. 15 lying task is also that in the case of

From the French patent specification 1 093 996 phase the throughput of the damping fluid is also known by throttling the compensating chamber of the compensating chamber and increasing the operating temperature after reaching the two-tube telescopic vibration damper. This concentric separating tube into an outer and a purpose serves the further feature of the invention to subdivide the inner annular space. The ao that with a telescopic vibration damper, with an outer ring with increased cooling, the direction of flow of the working piston acting for cooling in addition to a damping liquid of the working piston, which is directed in both stroke directions, is disordered at the front of the piston from the direction of movement of the working piston Bottom valve is dependent on the piston rod side, in the heated state of the damping-arranged throttle orifices constantly connected with the fluid ib ^r e flow direction also in the inner working space, so that, depending on the pressure annular space, the piston is independent of the direction of movement of the working conditions in the piston rod-side working space, while the flow damping fluid flows in both directions through the direction in the cold state in both annular spaces these throttle openings. When the working piston changes direction, cooling of the damping fluid can be effective on this 30 reverses. In this way, the damping fluid does not flow through, however, since the throughput in the warm state of the outer annular space is very low only in damping fluid. one direction. This ensures that with

The present invention now always has new partial quantities of liquid for each working stroke would be provided, the disadvantages described above bypassed the outer jacket and by the eliminate known vibration dampers, d. H. 35 airflow can be cooled. Such a measure a vibration damper of the type mentioned above is shown in FIG. 12 of the German patent type to create, in which the bandwidth of the possi- ble 1 216 126 is known per se, but not in borrowed temperature fluctuations of the damping connection with the features according to the invention fluid is reduced to a minimum. To solve two concentric annuli and one thermodes Problem is proposed according to the invention, 40 static control of the damping fluid. the that the measure known per se the flow of the damping fluid also only comes through The aforementioned inventive features control optimally from the work area into the compensation area The damping valve has a temperature that is known per se, because it is only dependent on the damping door when it is heated Control valve is connected downstream, which the liquid expediently (optimal cooling effect), at Damping liquid displaced from the working space - on the other hand, cold damping liquid from the above speed in the cold state in the inner annulus and the reasons stated is undesirable. after heating to a given temperature The choice of a suitable, temperature-dependent

leads into the outer annulus. controllable valve is basically at will

On the one hand, this provides optimal cooling for the specialist. For example, it would be conceivable

of the heated damping fluid, namely 50 that - as is known per se as temperature-

Lich through heat exchange with the external, independently controllable valve, an expansion valve The damper housing is constantly cooled by the airstream. serves. According to the invention, however, constnik-on the other hand are preferred for a cold dampening and cost reasons that as a liquid - In that they only have a bimetallic sheet in the inner, temperature-dependent controllable valve comparatively well insulated annulus of the supply 55 is used The temperature-dependent controllable valve is Raumes reaches - the best conditions for an appropriately ring-shaped bimetal disc with zeneine rapid heating to normal operating central recess formed in such a way that it is in the temperature given. It is thus - largely uncold - a slightly conical and dependent on it has a flat shape depending on the outside temperature or the warmed state, seasonal influences - one also with permanent 60 Except for the thermostatically controllable valve The temperature of the damping bimetallic sheet is the one channel to the inside fung liquid and thus a correspondingly equal annular space closing or releasing control remaining Function of the vibration damper valve on towards the outer ring space guaranteed As a result, there is an opening, spring-loaded non-return valve Significant advantage: 65 valve switched in parallel. As a damping fluid, relatively cheap pressure levels can increase the damping force, which is the case with er oils be used; there is no need for expensive dampening fluid that is beneficial in their viscosity behavior of the temperature It is also recommended that the temperature-

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dependently controlled control valve parallel-connected the seat for the temperature-dependently controlled one

To design the check valve in such a way that a valve control valve opens in parallel check valve

body of the check valve in its opening points.

position against a baffle plate comes to rest, according to the invention, the cap fulfills a behind which, in a manner known per se, a further structurally advantageous function is added to the 5 gas filling receiving gas space is arranged. going that between valve housing of the push-up-like already indicated, temperature valves and sealing caps need the temperature-related Volume changes of the damping fluid-dependent controllable valve forming bimetal disc speed is clamped because of the made possible by the invention.

Little temperature fluctuations are hardly taken into account. The fixing of the end on the piston rod side to be seen, so that the gas space in the advantageous separating tube should according to a preferred Aushafter Way can be kept small. The volume, guide form of the invention take place in that which is displaced by the piston rod, the same becomes a constriction at this end the baffle plate is pressed and points out again, with which it is at the corresponding end of the fetched. The baffle plate is intended to mix the working cylinder, but with one Complicate the damping medium with the gas. That part of the circumference through-flow slots between For this reason and in order to maintain cavitation in the separating tube and working cylinder, gas protrudes prevent, under slight pressure, the outer annulus with the inner annulus warming only slightly increased The gas pressure is connected.

not required to generate any damper forces. Embodiments of the invention are used in the. The increase in pressure is explained in more detail over the expansion of the following description on the basis of the drawing for practical installation in the vehicle. It shows
imperceptible. The gas space is more practical. 1 shows an embodiment of a telescopic vibration damper connected to the outer annular space according to the invention through a central recess in the impact-related telescopic vibration damper in the longitudinal disk, so 25 section,

that the gas is the damping liquid located there. F i g. 2 the flow conditions of the damping

can apply. liquid in the cold state in the compression stage

It has already been indicated that the damping a telescopic vibration damper according to Fi g. 1,

resistance to the piston movement was not provided by the fig. 3 the flow conditions of the damping

Gas cushion can be influenced. Rather, the damping fluid is in the cold state in the rebound stage

iung resistance by in a known manner a telescopic vibration damper according to FIG. 1

valve springs acting on the damping valves and

determined whose bias is expediently adjustable F i g. 4 the flow conditions of the damping is possible. With the last-mentioned measure, a liquid in the heated state is in the pressure resp. Adjustment of the damper identification possible. 35 rebound stage in a telescopic vibration damper

With regard to the formation of the in the on according to FIG.

The end of the working space on the piston side is arranged. A tubular outer housing 10 of the telescope is arranged Valve bottom with vibration damper through damping valves, which this reversed on all sides Connecting channels between the Ar- is on its upper face by a working space and the compensation space is closed according to the 40 housing cover 11, which is a preferred Embodiment of the invention pre-fastening bolt 12 carries for the connection of the struck that opposite the central axis on the outside telescopic vibration damper, for example arranged intake ducts in the valve base, which form a body of a motor vehicle. By through an opening in the rebound damping valve an annular seal 13 is the interior of the be controlled directly with the inner annulus 45 telescopic vibration damper opposite the outer end Compensating space are in connection, while the atmosphere is sealed gas-tight. The lower evening internally arranged throttle channels, which by a circuit of the telescopic vibration damper forms a in the pressure stage opening damping valve ge piston rod agitation 14, which together with be controls, open into a space that zui via an elastic piston rod seal 15 a guide and sealing of a piston rod II depending on the temperature of the control valve controlled ring-shaped channel with the inner ring-serves, at the upper end of which a working piston Π space and a check valve with which the telescopic vibration damper is screwed outer annular space of the compensation space connect via the piston rod guide 14, which also the is cash. Piston rod seal 15 receives, the outside Furthermore, with regard to the structural 55 housing 10 is rolled up, and the telescopic oscillation Training of the shock absorber according to the invention damper is thus closed. The piston rod K as particularly advantageous in terms of production and assembly, it has a fastening eye at its lower end Haft suggested that the piston on the front side 18, which zui attachment of the Teleskopschwin Valve bottom arranged at the end of the working space, for example on a wheel carrier to fix the working cylinder and the separating 60 of a motor vehicle, is used, working piston 17 um The tube in the outer housing is stepped piston rod 16 are in a working cylinder 1! and a side recess for connection slidably disposed, and the former is through a its externally arranged intake channels and the piston ring 20 relative to the working cylinder 19 sealed by the control valve depending on the temperature. The upper end of the working cylinder Has channel with the inner annulus. 65 19, which runs through the piston rod guide at the bottom The space in which the one arranged throttle is closed off forms a valve bath 21 Channels open into the valve base, is covered by a verder and a closure cap 22 Closing cap covered, which is in its center To fix the housing cover 11 and de

» L ·

2 7 57

9 10

Valve bottom 21 and indirectly also the working check valve 50 arranged 22 is open. In A spacer sleeve 23 is used for cylinder 19. A valve body 51 of the is located between the open position of the spacer sleeve 23 and the valve base 21 is the check valve on.-ter baffle plate 49 on, wherein the cap 22 clamped. jtJoch a narrow passage opening 52 for the

The space between the working cylinder 19 5 damping fluid remains open in order to and the outer housing 10 forms a compensating equalizing volume of the piston rod space for being displaced by the piston rod.

Damping fluid. It is through a separating tube 24 Above the valve base 21 is a control valve

arranged in an inner annular space 25 and an outer 53, which is divided depending on the annular space 26. The separating tube 24 operates at the temperature of the damping fluid and consists of a bimetallic disk at its upper end from the valve base 21. This bimetal hold. At the bottom, however, it has a constriction 27 washer between the valve base 21 and the one with which it rests against the working cylinder 19. The cap 22 is clamped. Depending on the "constriction 27 is in front of the circumference. Position, the temperature-dependent control valve interrupts flow slots 28, which establish a connection between the two annular spaces 25 and the damping fluid flow pressed through the throttle channel 31, either in the inner 26. A connection between an upper annular space 25 or through the piston front-open check valve 50 located by a spring 54 above the working piston 17 in the outer side chamber 29 of the working space and the annular space 26. The position mentioned is taken by the inner annular space 25 is provided by several lateral aa bimetallic discs of the control valve 53 when the recesses 30 are cold, throttle channels 31 and a damping fluid. It is shown in FIGS of the control valve 53 goes from Fig. 4 sensitive piston rod-side chamber 33 of the Ar and applies to a strongly heated damping working space through a suction channel 34 in the liquid.

Piston rod guide 14 with both the inner The mode of operation of the part according to the invention

Annular space 25 as well as with the outer annular space 26 of the scopic vibration damper is now as follows, whereby the connection between the piston is initially a cold state of the damping liquid side 29 and the piston-like appearance are assumed to be: in the pressure stage side chamber 33 is represented by another, the 30 (movement of the working piston 17 according to arrow 55 ic working piston 17 penetrating throttle channel 35 Fig. 2) the damping fluid is from dei. In the rest position of the working piston 17, the chamber 24 on the piston side, through which the throttle channels 31 and 35 and the intake 46 and the throttle channel 31 are positioned against the channels 32 and 34 through damping valves 36 and 35, respectively. Resistance of the on the valve plate of the damping 39 and 37 or 38 closed. The valve spring 40, which also acts as valve 36, as well as damping valves 36, which work through check valves, open only when the bimetal 37, 38 and 39 are bent upwards when the control valve 53 has a corresponding disk between it and the movement of the working piston 17 as a result of the in whose valve seat 56 opening radial channel 57 in the chamber 29 or 33 occurring underpressure or the inner annular space 25 (arrows 58 and 59) ge overpressure. In the present case, the attenuation (arrow 60) opens when the pressure is negative in the piston rod guide 14 in the chamber 29 or 33, the damping valves 36 or piston rod-side chamber 33 de. Open work rooms «39. The valve plates of the damping valves are sucked in (arrow 61). The damping resistance wire

36 and 39 are each acted upon by a section of the throttle duct 31 and the intake duct, on the one hand, by the transversely formed valve spring 40 and 41 in the pressure stage their bias by a nut 42 or 43 34 and by the bias of the valve spring 4C is adjustable thereby Lt a setting that determines the damping valve 39 in the working piston Damper detection possible. The pressure 17 remains closed in the pressure stage.

springs 40 and 41 each by a bolt 44 and 50 In de? Rebound stage (movement of the working piston 1 "

45, the bolt 44 in the valve base 21 at the same time according to arrow 62 in Fi g. 3) on the other hand, the damper opens

to fix the valve plate of the damping valve fungsventil 39 in the working piston 17, so that eir

37 serves. The valve plate of the damping valve 37 fluid exchange through the throttle channel 3f has a recess 46, dwnit damping between the piston-facing chamber 29 around fluidity from the piston-side chamber 29 in 55 of the piston-rod-side chamber 33 of the working the throttle channel 31 can reach. room can take place (arrow 63). The ones in the print

As can be seen in particular from FIGS. 2, 3 and 4 through the exiting volume of the pistons, a gas space 47 above the valve bottom rod 16 is the resultant enlargement of the total 21 with a gas volume of the chambers 29 and ^{1 under low pressure} "* 3 is filled by refilling, while the chambers 29 and 33 of the 6u flow of damping medium into the working space and - to some extent - also the ring.

spaces 25 and 26 filled with damping fluid due to excess pressure in the piston rod side egg

are. The gas chamber 47 is closed at the bottom by a chamber 33 with the damping valve 38 a central recess 48 provided impact and negative pressure in the piston front side egg disk 49 delimited, d> 3 a mixture of 65 chamber 29, the damping valve 37 is open Dif Is to prevent gas with the damping liquid. Damping fluid therefore now flows in the ring As FIG. 4 shows, there is contact with the space 25 according to arrow 64 τ η in the opposite direction unc Gas instead when sin in the center of the cap passes through the suction channel 32 from above ii

- ■ - «Β *. 27 57

the piston-enclosed chamber 29

as s-

Chamber 33 of the

For this purpose 2 sheets of drawings

27 57

Claims (12)

Patent claims: 1. Hydraulic two-tube telescopic vibration damper, especially for vehicles, consisting of a piston rod attached to the end of a piston rod, displaceable in a working cylinder filled with damping fluid and provided with at least one damping valve that controls the flow of damping fluid depending on the direction and a working piston The cylindrical outer housing concentrically surrounding the working cylinder, which after the working cylinder forms an annular compensating space for the damping fluid displaced by the piston rod, which is connected to a working space enclosed by the working cylinder at at least one end via damping valves which control the flow of the damping fluid depending on the direction and which is divided into an outer and an inner annular space by a separating tube concentric to the outer housing and to the working cylinder, with at least part of the damping fluid displaced from the working space for cooling in the outer ring ring adjoining the outer housing cooled by the airstream, characterized in that the Pämpfungswntil (36) controlling the flow of the damping fluids from the working chamber (chamber 29) into the balancing chamber (ring chambers 25 and 26) A known temperature-dependent control valve (53) is connected downstream, which conducts the damping liquid displaced from the working chamber in the cold state into the inner annular space (25) and, after heating to a predetermined temperature, into the outer annular space (26). 2. Telescopic vibration damper according to claim 1, which is at the end of the piston face Working chamber has a damping valve which opens in the pressure stage, characterized in that that the working piston (17) in a known manner only one opening in the rebound stage Has damping valve (39) and in the '.5 Pressure stage opening damping valve (36 ") at the piston end of the working space temperature-dependent control valve (53) is connected downstream. 3. Telescopic vibration damper according to Proverbs 1 and 2, in which the flow direction of the damping fluid directed into the outer annular space for cooling is independent of the direction of movement of the working piston, characterized in that in the heated state of the Da. ^The direction of flow in the inner annular space (25) is also independent of the direction of movement of the working piston (17), while the direction of flow in the cold state in both annular spaces (25 and 26) reverses when the working piston (17) changes direction. 4. Telescopic vibration damper according to claim 1 and optionally one or both of claims 2 and 3, characterized in that a Dehnstotfregler A \ int as a temperature-dependent control valve (53) in a known manner 5. TeleskopSGhÄmgungsdamper according to claims 1 and 4 and optionally one or Both of claims 2 and 3, characterized in that a bimetal sheet serves as the temperature-dependent control valve (53) in a manner known per se 6. Telescopic vibration damper according to claims 1, 4 and 5 and optionally one or both of claims 2 and 3, characterized in that the temperature-dependent control valve (53) is designed as an annular Bnnetallscheibe clamped on its circumference, which is a slightly conical in the cold state and in the heated state has a flat shape. 7. Telescopic vibration damper according to claims 1 and 2 and optionally one or more of claims 3 to 6, characterized in that the one channel (57) to the inner annular space (25) closing or releasing control valve (53) in the direction of the outer annular space ( 26) opening check valve (50) loaded by a spring (54) is connected in parallel. 8. Telescopic vibration damper according to claims 1, 2 and 7, characterized in that that the control valve (53) parallel-connected check valve (SO) at the same time as a damping valve to increase the damping force in the Pressure stage is formed when the damping fluid is heated. 9. Telescopic vibration damper according to the claims 1, 2, 7 and 8, in which part of the compensation chamber is filled with gas, characterized in that that a valve body (51) of the check valve (50) in its open position comes to rest against a baffle plate (49), behind which a the gas filling receiving gas space (4Ό arranged is 10. Telescopic vibration damper according to claims 1, 2 and 7 to 9, characterized in that that the gas space (47) through its central recess in the baffle plate (49) with the outer annulus (26) is connected. 11. Telescopic vibration damper according to claims 1, 2, 7 and 8 and optionally one or more of the remaining claims 3 to 10, in which the damping force is determined by the valve springs acting on the damping valves, characterized in that the bias of the valve springs (40 and 41) the case of overpressure in a chamber (29 or 33) of the opening Avbeitsraumes damping valves (36 or 39) and the bias of the Fede- of the check valve (50) are adjustable (54) in manner known per se. 12. Telescopic vibration damper according to claims 1, 2 and 7 and optionally one One or more of the remaining claims 3 to 11, in which a valve base is arranged at the piston end of the working space, which through Has damping valves controlled connection features between the working space and the compensation space, characterized in that suction channels (32) in the valve base (21) arranged on the outside with respect to the central axis, which pass through a damping valve that opens in the rebound stage (37) are controlled, are directly connected to the inner ßingnram (25), while internally arranged throttle channels (31), which are controlled by the damping valve (36) that opens in the pressure stage, open into a space that is accessed via the control valve (S3) controlled annular channel (Sf) to the inner annular space (25) UUD via the check valve (5 NC) m the outer Ringranm (26) is connectable 13 Teieskopschwingungsdämpfer after the fractures 1, 2, HND 12, gekeünzeichnet characterized in that the at The valve base (2l) arranged at the piston end of the working chamber for fixing the working cylinder (19) and the ^ S (24) in the outer housing (Ϊ0) is supported and ine lateral recess open Working cylinder concentric separating tube J ^ em » outer and an inner annulus önteneiu, w- With at least some of the ans dem ^ ^{™haben 1} ™ V * " urged damping fluid for ™ ung s outer, to which the wind blows: housing adjacent annulus v With two-pipe Meskor ^ chwmgmajd AA described above, vne »^ by the t'SA. Patentschnfl12785 ™ ± 0 French patent specification 1093 996 are known, the damping fluid is the piston stroke through ^ f ^? ^ ⁰¹ * space in the outer compensation space - and vice versa - Βζ * »»: * equal and Vorxatsraum "Sg compensation for the ^