FR2510692A1 - Hydraulic shock absorber for vehicle - has symmetrical blades on central shaft dividing hydraulic cylinder into two volumes - Google Patents

Abstract

The shock absorber is for vehicles whose suspension springs are made by torsion bars, such as tracked vehicles, and has a shaft (18) supporting two blades (20,21) symmetrically fixed to the shaft. The bearing (7) is made of two circular end plates (8, 9) connected by two plane pieces (10) symmetrical with respect to the longitudinal axis of symmetry. The shaft is placed in the bearing so that the blades (20,21) form, between the plates (8,9) and the cylindrical housing (1), two volumes (35,26) whose capacities vary as the shaft rotates.

Description

HYDRAULIC SHOCK ABSORBER

  The present invention relates to shock absorbers

  hydraulic and more particularly a damping

  eur intended for vehicles whose suspension springs are made up of torsion bars, for example che-illé vehicles It is designed to be housed in the bearing supporting the suspension arm and its tubular shape leaving a space in its central part free of large diameter, allows it to be crossed by the supporting shaft

the suspension arm.

  This shaft rotates the moving part of

  the shock absorber during suspension travel.

  The shock absorber assembly is as essential

  partially subjected to the damping torque while most of the other reactions caused by the suspension are taken up by the bearing supporting the suspension arm. There are already dampers of the so-called type & paddles, but none of these really respond to necessities of modern technology, and is

  why the present invention aims to achieve

  ser a hydraulic damper of the so-called paddle type having a structure allowing easy manufacture and assembly without difficulties, for essentially

reduce the manufacturing cost.

  But the object of the present invention is also, in the context of this advantageous shock absorber embodiment, to give it an increased lifespan by allowing it to operate for times much longer than those of the prior art. More specifically, the present invention relates to

  a hydraulic damper of the paddle type, charac-

  terrified by the fact that it has a supporting tree

  as two symmetrical pallets fixed on said shaft, a monobloc bearing made up of two connected crowns

  between them by two symmetrical bars in relation

  port to a longitudinal axis of symmetry>

  a cylindrical casing comprising a shoulder

  front of abutment surrounding said monobloc bearing, said shaft equipped with the two said pallets being arranged in said bearing so that the two pallets form between the two crowns, the two bars and said casing two volumes whose value varies in opposite direction when said shaft turns relative

audit bearing.

  According to another characteristic of the present invention, said damper comprises means for compensating for fluid arranged in at least one of the two said pallets.

  According to another characteristic of the present invention

  tion, said fluid compensation means consist of at least one reservoir produced in

  said pallet, said tank comprising a reservoir

  ve of fluid, controllable means for communicating said reservoir with at least one of said volumes and, means for applying pressure to said

  fluid contained in said reservoir.

  Other features and advantages of this

  invention will appear during the description

  following given with reference to the accompanying drawings, by way of illustration but in no way limitative, in which: FIG. 1 represents, in an exploded perspective view, an embodiment of a shock absorber according to the invention,

  Figure 2 shows a half section along

  dinal of the shock absorber according to Figure 1, Figure 3 shows a cross section of the shock absorber according to Figures 1 and 2, and, Figure 4 shows a view developed on a plane of one half of a shock absorber according to figures

1 to 3.

  It should be noted that the figures representing the same embodiment of a shock absorber, the same

  references denote the m 8 my elements.

  The embodiment of the shock absorber illustrated is constituted by: 1 a cylindrical casing 1, comprising a shoulder 2 The cylindrical casing 1 comprises a series of radial holes 3, in which are immobilized pins 4 The shoulder 2 has a series of holes 5 parallel to the axis of revolution of the casing 1, in which are immobilized pins 6 The casing 1 is immobilized in rotation in the bearing 66 supporting the suspension arm of the vehicle by suitable means , for example radial grooves 23 which correspond to similar grooves in the body of the bearing 66.

  a shock absorber bearing 7 which is housed in the bore

  main ge of the casing 1 and abuts against the shoulder 2 The bearing 7 consists of two

  crowns 8 and 9 interconnected by two bars-

  rettes 10 and 11 symmetrical about the axis

  longitudinal, the whole forming a monobloc assembly.

  The crown 8 comprises: a series of radial holes 12 corresponding with the holes 3 of the casing 1, and in which come

  to place the immobilization tokens 4.

  two grooves 13 and 14 for mounting the

seals.

The crown 9 comprises:

  a series of holes 15 parallel to the longitu-

  dinal of the corresponding shock absorber with the holes of the shoulder 2 and in which come

house the immobilization tokens 6.

  two grooves 16 and 17 allowing the mounting of the seals,

  a hollow shaft 18 which is received in the bearing 7.

  The inner bore of this shaft includes rods

  lures 19 allowing it to be driven in rotation by the shaft 65 which carries the suspension arm, two movable pallets 20 and 21 mounted symmetrically with respect to the axis of the hollow shaft 18 and fixed to the latter by screws 22 Each of the pallets and 21 has several sealing flaps 23-1, 23-2, 24-1, 24-2, adjusted sliding in the housings -1, 25-2, 26-1, 26-2, and applied against the faces corresponding crowns 8 and 9 by spring blades 27 at the rate of one leaf spring per sealing flap. The movable pallets 20 and 21 which move in

  rotation in m Ome time that the hollow shaft 18 has

  are trying the transfer control devices the

  liquid in the shock absorber described below.

  The movable pallets 20 and 21 being symmetrical with respect to the axis of the damper, it is only described the devices located in the pallet 20 This is how they comprise: two volume compensation chambers 28 and 29 The chamber 28 is in communication with the working chamber of the shock absorber 7-5 via

  the hole 30 and the flat make-up valve 32.

  The chamber 29 is in communication with the working chamber 36 via the hole 31 and the

flat valve for feed 6.

  The make-up valves 32 and 33 are fixed to the pallet 20 by screws 34 The compensation chambers 28 and 29 are limited, on the one hand, by the corresponding faces of the rings 9 and 8, and

  on the other hand, by pistons 37 and 38 fitted each

  cun of a Seal and which are 6 balances

  by springs 39 and 40 respectively.

  a central chamber 41 comprising the damping valves proper This chamber is closed at each of its ends by two seats 42 and 43 each held in place by a circlip

44 and 45.

  These monkeys are respectively fitted with valves

  damping 46 and 47 These two dampers

  are kept in their seat by the res-

  return spell 48 These damping valves have a skirt 67 and 70 a Just in the corresponding bore 68 and 71 of the seat and in which slots 69 and 72 are made allowing the

passage of the liquid.

  The seat 42 has a groove 49 and orifices

  which are in communication by the groove 51 pra-

  ticked on the hollow shaft 18 with the working chamber

vail 35.

  The seat 43 has a groove 52 and orifices

  53 which are in communication by the groove 54 pra-

  ticked in the hollow shaft 18 with the

work 36.

  A non-return valve with blade 55 fixed by a rivet 56 in the pallet 20 allows the passage of the liquid

  from the central chamber 41 to the working chamber

  vail 36 via ports 57 and 57-1

  and of the groove 58 formed in the hollow shaft 18.

  A non-return valve with blade 59 fixed by a rivet 60 in the pallet 20 allows the passage of the liquid from the central chamber 41 to the working chamber 5 via the orifices 61 and 61-1 and

  of the groove 62 formed in the hollow shaft 18.

  The operation of the shock absorber described above is as follows: The shock absorber includes qfaatre working chambers

35,36,63,64.

  The chamber 35 is delimited by: a part of the external lateral surface of the hollow shaft 18, a part of the internal lateral surface of the cylindrical casing 1, a radial face of the pallet 20, a radial face of the bar 11,

  part of the flat inner face of the neck

line 8,

  part of the flat outer face of the

line 9.

  It is easy to see that the other three bedrooms of

  work are delimited in m 9 my conditions.

  The working chambers 35 and 63 are symmetrical

  relative to the longitudinal axis of the shock absorber.

  The same is true of working chambers 36 and 64.

  When the hollow shaft 18 rotates under the action of the stresses of the suspension, it enters with it the movable pallets 20 and 21 and, therefore, the symmetrical working chambers 35 and 63 or

  36 and 64 increase or decrease in volumes together

  ble, the direction of the volume variation being invert-

  for the two groups of working chambers

  metrics. Controlling as will be explained below the transfer of the volume from chamber 35 to the chamber

  36 and from room 63 to room 64 and vice versa-

  ment following the direction of rotation of the shaft 18, the pressure is increased in one of the two groups of symmetrical working chambers, which causes the birth of a resistant couple on the hollow shaft 18 which is precisely the torque d amortization created

by the shock absorber.

  Let us examine by way of example, in more detail, what happens during the transfer of the volume of liquid located in the chamber 35 towards the chamber 36, that is to say when the pallet 20 moves in the direction of the

arrow F (see fig 4).

  The liquid located in the chamber 35, the volume of which decreases, passes through the groove 51 and the groove 49 & through the orifices 50 of the seat 42 repelling the

  damping valve 46 against the return spring

  pel 48 The liquid arrives in the central chamber 41, passes through the orifices 57 and 57-1, pushes the non-return valve 55 and ends by the groove 58 in the chamber 36 whose volume increases.

  note that due to the crossing of the overflow valve

  weaving 46, the pressure rises in the chamber 35 to a value depending on the characteristics of the valve 46 dimensions of the slots and of the seat,

  of the spring 48 and the drive speed

  pallet 20 This pressure applies the

  non-return valve 59 on the ends of the orifices

  these 61 and 61-1 pocketing the liquid from the chamber 35

  to enter chamber 41 otherwise than in French

  squeezing the damper 46 Pressure

  reached in chamber 35 creates a resistance force

  advancement of the pallet 20 in its movement

  vement. The phenomena that we have just described for the

  working chamber 35 occur in the same way

  simultaneously in the working room

  symmetrical 63 So that for a sense of stress

  given tation of the shaft 18, a group of symmetrical working chambers is under pressure, while the second group of symmetrical working chambers is in depression The phenomenon is reversed for the reverse stressing direction of the shaft 18 We see

  so easily that one adorns in this way a

  full resistant on the shaft 18 in both directions of rotation The volume compensation chambers 28

  and 29 are intended to absorb variations in your

  lumes of oil contained in the shock absorber due to variations in operating temperature

  and moreover, to compensate for leaks between the various

  its parts in order to keep the working chambers always correctly filled with liquid. It will be noted that the make-up valves 32 and 33 are

  applied to their respective seats by the pres-

  Zion reigning in the corresponding working chamber

  dante, so as to avoid during pressing

  working chambers return of the liquid

to the clearing houses,; ion.

  In the exemplary embodiment of the hydraulic hye damper which has been described c: above with the support of FIGS. 1 to 4, the rolling means for bringing the two volumes or sections 35 and 36 into communication,

are located in the palette.

  But, it is quite obvious that the invention sa 4 ppliquó also to a hydraulic damper in which the rolling means could tra "r 6 alises da-s the walls of the bars 10 and 11, and the lainge of the fluid s' would therefore carry out between two contingent volumes separated by one of these two bars. ans zzo-çssezd eun ienbl: -rclde anod (0 # "6 C) BTXG úOtu Sep iqe (9 cllçc) semn-ro- & oq Tpoop un etrpour nv oe Ae a To Aaaega q Tpnp uo Tqvo Ttrnmoo tre eol: m op - (CCILC i ZC 10 c) Selq-epzmmmoo e Txe úOm Sep oc Op Tn Ij op 9 & aesga oirn; uuqaodmoo JTO Aagoga q Tpeo TPWI Stmp PSTI Uga (6 Z "RZ) z-rojuzeega un stz Tom nu vd sg> n 4 l: q Lstzoo quos ep-rn-rj op uo.F:;, estzeclmoo op sua úouz 9:; I: pser enb ; j: vj er avd go-Faqq -ovaiao e UOT 1-aorpuehea VI Txoreer iness-p-laomy / C (talloz) se:; qo Ted seq Tp xnep sep etin Ou Touz nv suvp spoodo Tp ep Tnlj op ('" 6 Z "PZ) scores -uec Tmoo op Gtx O úOm Se P e: -z O c Tm O o -r-Finb 11: -ej e T a-aci 991: agq -0 vamo Uo Tqv o Tpue & Ga VI uo Tes aness Tqaomy / Z 99 = 10 A Oq Tpsep Xnep STXTOM oz nie az- lzw oprn Tj: np (Mi igt?) e'q'eczl: uml Op STXGXOM Sep:; e gae T Tvd 4 Tpnv 4 aoddva avd aumoq eaqau q-Fpe T puunb esze & U-F Sues tre G-Fa U & me-rie & VI quop (g C "C) somn-ro A xnep ao 4 woo ql: pe T qe oe ;; eza -eq xnop se I eseuuoanoo xnep Sel eaque eunovqo 4 uemaoj 9944 Blvd xnep L sol enb uobvj op W ao Trud q Tpel su-ep q Sods Tp 4 u-eqg

  (LLPI'OZ) se-iqe-r-'ed sell: p xnop sep gdl: nbp eaqa-a q Tpel.

  O Tqotxom ae Blvd q Tpel quvano 4 ue 994 nq op: toe Aa GS (Z) -itzeme-rnede un quuqioduroo (t) enb-Frptzl: -rúo ae; aieo un I'r'etzl: p Ob -n; TS Txol e Ta 4 ga Li Ce op oxv un -q qaodclva avd sonb Taqgmús (O t) seq 4 eaaeq xnop jed saddled ea 4 ue soe Tjea (6 'a) se = oanoo xnop op gnq Tqszroo (Z) oolqouotu ao Trecl un (PL) eaqjv; Tpel ans seqx Tj sonb Taqqu Lîs (LZIOZ) sqq-lerec, xnop:; zmlaoc Tclne (q Q oaqaie im eqaodwoo -rl:, nb eC aud lenb T Invap úq aness T; aomy / L sx O 1 1 y O 1 a N a A ff 9 Ob

2690 L Z

  said fluid contained in said reservoir.

  4 / damper according to claim 3

  characterized by the fact that said means control

  dables for placing said reservoir in communication with at least one of said volumes are constituted by a conduit (30,31) passing through said pallet, a fluid valve (32,33) disposed in said conduit, said valve having a direction passing from said reservoir to said volume and a clogging sense

from said volume to said reservoir.

  / Shock absorber according to one of claims 4 and 5 characterized in that the means for applying pressure to said fluid contained in said tank comprises a separating piston (37,38) sliding in said tank with seal in contact with said fluid, and means (39,40) for exerting a force on said piston (37,38) tending to compress said fluid

fluid.

  6 / damper according to claim 5 characterized in that said means for exerting a force on said piston consist of a spring (39.40) disposed between said piston

  (37,38) and part of the wall of said tank.

  7 / Shock absorber according to one of claims

  previous characterized in that said rolling means are located in said pallets.

  8 / Shock absorber according to one of claims

  1 to 6 characterized in that said means

  are located in said bars.