EP4581281A1 - Amortisseur hydraulique pour suspension de véhicule pourvue d'un élément d'arrêt d'extrémité hydraulique fonctionnant pendant la course de compression de l'amortisseur - Google Patents

Amortisseur hydraulique pour suspension de véhicule pourvue d'un élément d'arrêt d'extrémité hydraulique fonctionnant pendant la course de compression de l'amortisseur

Info

Publication number
EP4581281A1
EP4581281A1 EP23776096.2A EP23776096A EP4581281A1 EP 4581281 A1 EP4581281 A1 EP 4581281A1 EP 23776096 A EP23776096 A EP 23776096A EP 4581281 A1 EP4581281 A1 EP 4581281A1
Authority
EP
European Patent Office
Prior art keywords
shock absorber
cup
shaped body
secondary piston
piston
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP23776096.2A
Other languages
German (de)
English (en)
Inventor
Luca BISTOLFI
Luca CAPURSO
Fabio COTTO
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Way Assauto SRL
Original Assignee
Way Assauto SRL
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Way Assauto SRL filed Critical Way Assauto SRL
Publication of EP4581281A1 publication Critical patent/EP4581281A1/fr
Pending legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/32—Details
    • F16F9/34—Special valve constructions; Shape or construction of throttling passages
    • F16F9/346—Throttling passages in the form of slots arranged in cylinder walls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/32—Details
    • F16F9/48—Arrangements for providing different damping effects at different parts of the stroke
    • F16F9/49—Stops limiting fluid passage, e.g. hydraulic stops or elastomeric elements inside the cylinder which contribute to changes in fluid damping

Definitions

  • a twin-tube hydraulic shock absorber for a vehicle suspension typically comprises an outer cylindrical tube, an inner cylindrical tube coaxial to the outer cylindrical tube and defining with it an annular chamber, a piston rod arranged coaxially to the two cylindrical tubes and partially protruding therefrom, and a main piston which is slidably mounted in the inner cylindrical tube and is fixed to the lower end of the piston rod.
  • the main piston separates the inner volume of the inner cylindrical tube into an extension chamber and a compression chamber, in which a damping fluid, typically oil, is contained.
  • the main piston is provided with a first pair of unidirectional valves, namely a compensation valve, which during the compression phase of the shock absorber controls the flow of the damping fluid from the compression chamber to the extension chamber, and a rebound valve, which during the extension phase of the shock absorber controls the flow of the damping fluid from the extension chamber to the compression chamber.
  • a valve assembly is provided at the bottom of the shock absorber and comprises a second pair of unidirectional valves, namely a compression valve, which during the compression phase controls the flow of the damping fluid from the compression chamber to the annular chamber, and an intake valve, which during the extension phase controls the flow of the damping fluid from the annular chamber to the compression chamber.
  • a hydraulic shock absorber for a vehicle suspension provided with a hydraulic end stop member operating in compression is described, for example, in WO2016/146660.
  • This document discloses, in particular, a hydraulic shock absorber for a vehicle suspension in which the hydraulic end stop member comprises a cup-shaped body mounted in the compression chamber of the shock absorber, coaxially thereto, and a secondary piston attached to the piston rod of the shock absorber, in particular coaxially thereto and underneath the main piston, so as to slide in the cup-shaped body when the shock absorber approaches the end-stroke position during the compression stroke.
  • the cupshaped body comprises a side wall and a bottom wall which define, together with the secondary piston, a working chamber in which the damping fluid is compressed by the secondary piston when the latter slides in the working chamber towards the bottom wall of the cup-shaped body.
  • axial grooves or channels are provided on the inner surface of the side wall of the cup-shaped body to allow the damping fluid to flow axially out of the working chamber when the secondary piston slides in the working chamber towards the bottom wall of the cup-shaped body.
  • the invention is based on the idea of providing a hydraulic end stop member which, as in the state of the art, also comprises a cup-shaped body and a secondary piston, but wherein, unlike the state of the art, the cup-shaped body is fixed to the piston rod of the shock absorber, in particular underneath the main piston, and wherein the secondary piston is configured to slide within the cup-shaped body in the final section of the compression stroke of the shock absorber due to the relative movement between the cup-shaped body, which is drivingly connected to the piston rod of the shock absorber, and the valve assembly at the bottom of the shock absorber.
  • the hydraulic end stop member further comprises a pin attached to the valve assembly at the bottom of the shock absorber and extending coaxially to the cup-shaped body, said pin being associated with the secondary piston so as to allow it to slide within the cup-shaped body in the final section of the compression stroke of the shock absorber.
  • the secondary piston is mounted outside the cupshaped body, in particular at the end of the pin attached to the valve assembly at the bottom of the shock absorber, so as to penetrate into the cup-shaped body in the final section of the compression stroke of the shock absorber.
  • the terms “axially” and “axially” identify the direction of the longitudinal axis of the shock absorber, as well as the longitudinal axis of the hydraulic end stop member.
  • terms such as “upper” and “lower” are intended to refer to the shock absorber arrangement shown in Figures 1 and 7, with reference respectively to the first and second embodiments of the invention proposed herein, wherein the main piston of the shock absorber is mounted at the lower end of the piston rod and therefore the piston rod and the main piston move downwards during the compression stroke of the shock absorber and upwards during the extension stroke of the shock absorber.
  • the main piston 20 separates the inner volume of the inner cylindrical tube 14 into an upper chamber 22, or extension chamber, and a lower chamber 24, or compression chamber, in which a damping fluid, typically oil, is contained.
  • a damping fluid typically oil
  • the secondary piston 38 also has, in the illustrated example, a cup-shaped configuration, with a bottom wall 46 and a cylindrical side wall 48.
  • the bottom wall 46 faces the open end, i.e. the lower end, of the cup-shaped body 36.
  • the secondary piston 38 is provided with sealing means (not shown), formed for example by a sealing ring, to ensure sealing between the cylindrical side wall 48 of the secondary piston 38 and the cylindrical side wall 42 of the cup-shaped body 36.
  • the secondary piston 38 has a through hole 50, which in the illustrated example is provided in the bottom wall 46, to allow the flow of the damping fluid in the direction from the compression chamber 24 to the inside of the cup-shaped body 36.
  • Elastic means are provided within the cup-shaped body 36, which are formed for example by a conical spring 54 and act on the secondary piston 38 so as to exert a downward elastic force on it, thereby tending to keep the secondary piston 38 in a lower end-stroke position, in which the secondary piston 38 abuts against a stop ring 56 mounted at the lower end of the cup-shaped body 36.
  • the hydraulic end stop member further comprises a pin 58, which is attached to the bottom valve assembly 30 of the shock absorber and extends upwards, i.e. towards the assembly formed by the cup-shaped body 36 and the secondary piston 38.
  • the pin 58 is arranged coaxially to the shock absorber, i.e. with its axis substantially coincident with the longitudinal axis z.
  • the pin 58 is normally at a distance from the secondary piston 38. In such a condition, the hydraulic end stop member is not working and therefore the damping force generated by it is zero, or substantially zero.
  • the secondary piston 38 penetrates more and more into the cup-shaped body 36, thereby urging the secondary piston 38 more and more towards the bottom wall 40 of the cup-shaped body 36, i.e. upwards, against the action of the conical spring 24. Consequently, the volume of the working chamber 52 of the cup-shaped body 36 is progressively reduced, thereby forcing the damping fluid contained in this chamber to flow out of it through the holes 44 provided in the cylindrical side wall 42 of the cup-shaped body 36.
  • the cup-shaped body 36 is provided with a pressure limiting valve, generally indicated with 60.
  • the pressure limiting valve 60 basically comprises a set of discs 62 (or, more generally, at least one disc 62) which are arranged in abutment against the upper face, i.e. the face facing the main piston 20, of the bottom wall 40 of the cup-shaped body 36, so as to prevent the flow of the damping fluid out of the working chamber 52 via through holes 64 provided in the bottom wall 40 of the cup-shaped body 36, up to a given limit value of the pressure in the working chamber 52.
  • the discs 62 deform elastically, thereby leaving a free passage between them and the upper face of the bottom wall 40 of the cup-shaped body 36.
  • the damping fluid can therefore flow from the working chamber 52 of the cup-shaped body 36 through the through holes 64 and the free passage between the bottom wall 40 and the discs 62, thereby avoiding a further increase in pressure in the working chamber 52 and consequently a further increase in the damping force on the piston rod 18.
  • the cup-shaped body 36 is fixed to the lower end of the piston rod 18 of the shock absorber using the threaded portion, indicated with 66, normally provided at that end for the mounting of a nut with which the main piston 20 of the shock absorber is fixed to the piston rod 18.
  • the bottom wall 40 of the cup-shaped body 36 has an axial threaded hole 68 into which the aforementioned threaded portion 66 of the piston rod 18 can be screwed.
  • one or more spacers 70 will also be mounted on the piston rod 18, between the main piston 20 and the cup-shaped body 36, in order to correctly position the cup-shaped body 36 with respect to the main piston 20 so as to avoid interference between said components, in particular between the discs 62 of the pressure limiting valve mounted on the bottom wall 40 of the cup-shaped body 36 and the main piston 20.
  • the cup-shaped body 36 can be easily mounted on the piston rod 18 of an ordinary shock absorber, without requiring any special modifications of the same piston rod.
  • FIG. 7 to 12 A further embodiment of a hydraulic shock absorber according to the present invention is illustrated in Figures 7 to 12, where parts and elements identical or corresponding to those of the shock absorber according to the embodiment of Figures 1 to 6 are indicated with the same reference numerals.
  • This further embodiment differs from the one previously described substantially in that the secondary piston 38 is not slidably mounted within the cup-shaped body 36, but is fixed to the free end (upper end) of the pin 58, and in that the cup-shaped body 36 is devoid of the stop ring 56 (as well as the spring 54), in such a way that during the compression movement of the shock absorber, starting from a certain point and up to the end of the compression stroke, the secondary piston 38 penetrates into the cupshaped body 36 and starts to slide inside it, thereby reducing the volume of the working chamber 52 of the cup-shaped body 36.
  • Figure 8 shows the condition in which, during the compression stroke of the shock absorber, the secondary piston 38 starts to enter the cup-shaped body 36, thereby closing the working chamber 52
  • Figure 9 shows the condition in which, still during the compression stroke of the shock absorber, the secondary piston 38 is completely inside the cup-shaped body 36
  • Figure 10 shows the condition in which, during the extension stroke of the shock absorber, the secondary piston 38 is still inside the cup-shaped body 36, but is now moving downwards with respect to the cup-shaped body 36.
  • the secondary piston 38 is provided with a non-return valve 76 having the function of allowing the damping fluid to enter the working chamber 52 of the cup-shaped body 36 during the extension stroke of the shock absorber.
  • the non-return valve 76 basically includes one or more discs 78 which are arranged on the upper face of the secondary piston 38 and are adapted to close a plurality of axial through holes 80 extending through the secondary piston 38 parallel to the axis thereof (i.e. parallel to the longitudinal axis z).
  • the discs 78 keep the axial through holes 80 closed during the compression stroke, while during the extension stroke they deflect or move (e.g.
  • the non-return valve 76 allows the damping fluid to flow from the compression chamber 24 of the shock absorber to the working chamber 52 of the cup-shaped body 36 through the axial through holes 80 in the secondary piston 38, as well as through the holes 44 in the cylindrical side wall 42 of the cup-shaped body 36.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Damping Devices (AREA)

Abstract

L'amortisseur hydraulique (10) comprend : un premier tube cylindrique (14), une tige de piston (18) qui est disposée coaxialement au premier tube cylindrique (14) et fait saillie d'un côté supérieur de celui-ci, un piston principal (20) qui est fixé à la tige de piston (18) et est monté coulissant dans le premier tube cylindrique (14) de façon à diviser le volume interne du premier tube cylindrique (14) en une chambre de dilatation (22) et une chambre de compression (24) contenant un fluide d'amortissement, et un élément d'arrêt d'extrémité hydraulique (36, 38, 58) qui est disposé dans la chambre de compression (24) et fonctionne dans une section finale de la course de compression de l'amortisseur (10) pour dissiper hydrauliquement l'énergie cinétique de la tige de piston (18). L'élément d'arrêt d'extrémité hydraulique (36, 38, 58) comprend : un corps en forme de coupelle (36), qui est fixé à la tige de piston (18), sous le piston principal (20), et est conçu de façon à être ouvert au niveau de sa partie inférieure, un piston secondaire (38), qui est conçu pour coulisser à l'intérieur du corps en forme de coupelle (36) dans la section finale de la course de compression de l'amortisseur (10) de façon à comprimer le fluide d'amortissement présent dans une chambre de travail (52) définie entre le corps en forme de coupelle (36) et le piston secondaire (38), et une broche (58) fixée à une zone inférieure du premier tube cylindrique (14) et s'étendant coaxialement au corps en forme de coupelle (36), la broche (58) étant associée au piston secondaire (38) de façon à permettre au piston secondaire (38) de coulisser à l'intérieur du corps en forme de coupelle (36) dans la section finale de la course de compression de l'amortisseur (10).
EP23776096.2A 2022-08-30 2023-08-22 Amortisseur hydraulique pour suspension de véhicule pourvue d'un élément d'arrêt d'extrémité hydraulique fonctionnant pendant la course de compression de l'amortisseur Pending EP4581281A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT202200017763 2022-08-30
PCT/IB2023/058351 WO2024047469A1 (fr) 2022-08-30 2023-08-22 Amortisseur hydraulique pour suspension de véhicule pourvue d'un élément d'arrêt d'extrémité hydraulique fonctionnant pendant la course de compression de l'amortisseur

Publications (1)

Publication Number Publication Date
EP4581281A1 true EP4581281A1 (fr) 2025-07-09

Family

ID=84360062

Family Applications (1)

Application Number Title Priority Date Filing Date
EP23776096.2A Pending EP4581281A1 (fr) 2022-08-30 2023-08-22 Amortisseur hydraulique pour suspension de véhicule pourvue d'un élément d'arrêt d'extrémité hydraulique fonctionnant pendant la course de compression de l'amortisseur

Country Status (4)

Country Link
EP (1) EP4581281A1 (fr)
JP (1) JP2025527810A (fr)
KR (1) KR20250059461A (fr)
WO (1) WO2024047469A1 (fr)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6377972B2 (ja) * 2014-06-13 2018-08-22 ヤマハモーターハイドロリックシステム株式会社 単筒式油圧緩衝器
FR3074244B1 (fr) * 2017-11-29 2019-10-18 Psa Automobiles Sa Amortisseur hydraulique avec butee de fin de course autoreglable suivant la charge
IT201800010763A1 (it) * 2018-12-03 2020-06-03 Sistemi Sospensioni Spa Ammortizzatore idraulico, particolarmente per sospensione di veicolo, con tampone idraulico operante durante la corsa di compressione dell'ammortizzatore e con dispositivo di regolazione per regolare il comportamento del tampone idraulico in funzione del carico del veicolo.

Also Published As

Publication number Publication date
JP2025527810A (ja) 2025-08-22
KR20250059461A (ko) 2025-05-02
WO2024047469A1 (fr) 2024-03-07

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