NO820482L

NO820482L - DEVICE FOR HYDRAULIC CYLINDER FOR DUMPING MOTION TO END POSITION

Info

Publication number: NO820482L
Application number: NO820482A
Authority: NO
Inventors: Inge Blomqvist
Original assignee: Vaggeryds Mek Verk
Priority date: 1981-02-17
Filing date: 1982-02-17
Publication date: 1982-08-18
Also published as: SE8101054L; GB2095753A; DE3204358A1; FI820505L

Description

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Foreliggende oppfinnelse vedrører en anordning for bevegelsesdemping av stempel, med vedhengende deler i en hydraulsylinder, i stempelets endestilling. Slike an- The present invention relates to a device for damping the movement of a piston, with attached parts in a hydraulic cylinder, in the end position of the piston. Such an-

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ordninger er tidligere kjent fra eksempelvis SE^-utlegnings-skrifter 347 046 og 7713290-0, den siste med pubiiserings-nummer 416 157, som beskriver to konstruksjoner', der en har forsøkt å oppnå en tilfredsstillende endestillingsdemping ved hjelp av et sylindrisk dempingslegeme plassert ved stempelet og som i nærheten av endestillingen med et visst spill trenger inn i en kanal som struper den utstrøm-mende hydraulvæsken, hvor det er opptatt en ringformet utsparing som med aksialt spill opptar et likeledes ringformet strupelegeme, som under påvirkning av hydraulvæske-trykket, idet stempelet nærmer seg endestillingen, legger seg mot den av utsparingens sidevegger som ligger lengst bort fra stempelet og i denne stillingen utøver' ytterligere arrangements are previously known from, for example, SE^ layout documents 347 046 and 7713290-0, the latter with publication number 416 157, which describes two constructions', where an attempt has been made to achieve a satisfactory end position damping by means of a cylindrical damping body placed at the piston and which near the end position with a certain play penetrates into a channel which throttles the outgoing hydraulic fluid, where an annular recess is occupied which with axial play occupies an equally annular throttle body, which under the influence of the hydraulic fluid pressure, as the piston approaches the end position, it rests against the side walls of the recess which is farthest from the piston and in this position exerts further

<1>i strupning av hydraulvæsken, f.eks. olje, og dermed økende retardering av stempelbevegelsen, hvilket jo er; ønskelig for å unngå altfor store påkjenninger, som lettj oppstår idet stempelet nærmer seg en endestilling. ! <1>in throttling of the hydraulic fluid, e.g. oil, and thus increasing retardation of the piston movement, which is indeed; desirable to avoid excessive stresses, which easily occur as the piston approaches an end position. !

For å oppnå et ønsket retarderingsforløp, som er avpasset hydraulsylinderens arbeid, kan ifølge den ovenfor sist anførte patentskriften aksiale spor opptas i demping;;-legemets manteloverflate, og disse sporene kan varieres med hensyn til dybde og/eller lengde. Disse sporene vil da i forening med strup; elegemet danne lekkasjeviegger for hydraulvæsken og slik resultere i en strupning av hydraul-væskeutløpet, avhengig av stempelets avstand til endestillingen, fra stempelets trykkside og dermed jen tilpas-set retardering. I In order to achieve a desired deceleration sequence, which is adapted to the work of the hydraulic cylinder, according to the above-mentioned last patent document, axial grooves can be recorded in the casing surface of the damping body, and these grooves can be varied with respect to depth and/or length. These tracks will then in union with throat; the body forms leakage walls for the hydraulic fluid and thus results in a throttling of the hydraulic fluid outlet, depending on the piston's distance to the end position, from the pressure side of the piston and thus an adapted deceleration. IN

Idet stemp> elet senere snur på grunn av, Ihydraul- væskens endrete strømningsretning vil strupelegemet umiddelbart oppnå full adgang til motsvarende stempelside under hele den kommende drivingen av stempelet i den jnye retningen, As the piston later turns due to the hydraulic fluid's changed flow direction, the throttle body will immediately gain full access to the corresponding piston side during the entire upcoming drive of the piston in the new direction,

I samsvar med den ovenfor først nevnte^ patentskriften anvendes på samme måte i samsvar med foreliggende oppfinnelse et ringformet strupelegeme med ikke-deformerbart tverrsnitt, men den .er oppslisset og ligger med et visst elastisk trykk mot en av utløpskanalens s'ider, hvori-gjennom ekstra kanaler 14 må opptas i den veggen strupelegemet ikke ligger mot. Oppslissingen er også -nødvendig for inn- og uttaking av strupelegemet fra utsparingen. Denne anordningen er altså temmelig komplisert |og kostbar In accordance with the first-mentioned above-mentioned patent document, an annular throat body with a non-deformable cross-section is used in the same way in accordance with the present invention, but it is slit and lies with a certain elastic pressure against one of the sides of the outlet channel, through which extra channels 14 must be taken up in the wall the larynx is not against. The slitting is also necessary for inserting and removing the larynx from the recess. This device is therefore rather complicated and expensive

i framstilling og vedlikehold.in production and maintenance.

Også anordningen ifølge den ovenfor sistnevnte 'patentskriften er beheftet med anseelige ulempe,r. Her anvendes et ringformet strupelegeme med elastisk tverrsnitt, Also the device according to the above-mentioned last-mentioned 'patent document is subject to considerable disadvantages, r. An annular throat body with an elastic cross-section is used here,

■ bl.a. for å kunne innføres i og tas ut fra utsparingen,■ i.a. to be able to be inserted into and removed from the recess,

og den er utstyrt med spor fordelt rundt omkretsen, gjennom hvilke hydraulvæskenjpasserer ved tilbakebevegelsen. (Denne kon- and it is equipped with grooves distributed around the circumference, through which hydraulic fluid passes during the return movement. (This con-

struksjonen krever stor presisjon ved tilvirkningen og strupelegemet er relativt ømtålelig, og utsettes lett for slitasje, som påvirker dets levetid og funksjon'. the structure requires great precision during manufacture and the larynx is relatively delicate, and is easily exposed to wear and tear, which affects its lifespan and function'.

Det er også kjent anordninger med stive, forskyv-bare strupelegemer som ligger i utløpskanalene. Noen vari-abel strupning som likner den som påvirker strupelegemene ved anordningen i samsvar med foreliggende oppfinnelse finnes ikke. Ved disse anordingene synes det knapt mulig uten kompliserte foranstaltninger å endre det e,n gang inn-stilte strupeforløpet. There are also known devices with rigid, displaceable throat bodies located in the outlet channels. There is no variable throttling similar to that which affects the larynx bodies in the device according to the present invention. With these arrangements, it seems hardly possible without complicated measures to change the once set throat course.

Fordelene ved anorduiingen ifølge oppfinnelsen består i at strupelegemet ved helt å kunne innlåses i utsparingen ved hjelp av en låsering eller innvendig Seegersikring, som etter behov kan fjernes og settes jpå igjen, kan utføres særlig robust med ikke-def ormerbartj tverrsnitt og uten behov for å slisses opp. Montering og Idemontering d.v.s. utskifting av strupelegemet er derfor en svært enkel og rask operasjon, hvilket er en stor fordel, da nettopp The advantages of the device according to the invention consist in the fact that the throat body can be completely locked into the recess by means of a locking ring or an internal Seeger safety device, which can be removed and reattached as required, and can be made particularly robust with a non-deformable cross-section and without the need to slit up. Assembly and Idea assembly, i.e. replacement of the larynx is therefore a very simple and quick operation, which is a great advantage, precisely then

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disse strupelegemer kan bli sterkt slitt på kort tid ved intensiv drift, selv om dette ikke skjer så raskt med anordningen ifølge denne oppfinnelsen. Videre er tilvirkningen av utsparingen ifølge denne oppfinnelsen særs enkel fordi utsparingen har en svært enkel form. these larynxes can be severely worn in a short time during intensive operation, although this does not happen so quickly with the device according to this invention. Furthermore, the manufacture of the recess according to this invention is particularly simple because the recess has a very simple shape.

Det har vist seg særlig fordelaktig å oppnå den variable struping, som kreves idet stempelet nærmer seg endestillingen, gjennom de aksiale sporene, som er opptatt i dempingslegemer av typen angitt i kr,av 1. Disse sporene It has proved particularly advantageous to achieve the variable throttling, which is required as the piston approaches the end position, through the axial grooves, which are occupied in damping bodies of the type indicated in NOK, of 1. These grooves

kan lett anbringes og eventuelt justeres, dessuten kan hele dempingslegemet, idet minste på den ene siden, lett byttes ut dersom det er ønsket. Det har imidlertid vist sejg at høye trykkpåkjenninger oppstår ved strupestedene mellom sporene 30,31 og strupelegemet 8,9, idet stempeiet skal bremses ved endestillingen. Dersom strupelegemet ;da har fjærende tverrsnitt, oppstår elastisk deformasjon i.ukon-trollerbar grad og dermed øket slitasje og risiko for material-tretthet og eventuelt en forandring i dempings-evnen. can be easily placed and possibly adjusted, and the entire damping body, being the smallest on one side, can be easily replaced if desired. However, it has been proven that high pressure stresses occur at the throat points between the grooves 30,31 and the throat body 8,9, as the stem must be braked at the end position. If the larynx has a springy cross-section, elastic deformation occurs to an uncontrollable degree and thus increased wear and risk of material fatigue and possibly a change in the damping ability.

En formstabil utføring av strupelegemet er altså et viktig vilkår av flere viktige årsaker som også framgår av beskrivelsen i en viss utstrekning. A dimensionally stable design of the larynx is therefore an important condition for several important reasons which also appear from the description to a certain extent.

Ytterligere trekk ved oppfinnelsen framgår av de vedlagte patentkravene. Further features of the invention appear from the attached patent claims.

Oppfinnelsen forklares nærmere i tilknytning tilThe invention is explained in more detail in connection with

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et nedenfor beskrevet utførelseseksempel, med tilhørende vedlagt tegning som viser, delvis i tverrsnitt, et side-riss av en hydraulsylinde.r utsty^rt med en anordning i samsvar med oppfinnelsen. Det bør imidlertid iakttas at oppfinnelsen ikke er begrenset bare til det som' framgår av dette utførelseseksempelet uten at andre alternativ også omfattes av oppfinnelsen i den grad de kan leses ut av kravene eller kan ansees ekvivalente med disse.<j>På tegningen er følgend^e sifferbetegnelser benyttet: an embodiment described below, with the corresponding attached drawing showing, partly in cross-section, a side view of a hydraulic cylinder equipped with a device in accordance with the invention. However, it should be noted that the invention is not limited only to what appears in this embodiment without other alternatives also being covered by the invention to the extent that they can be read from the requirements or can be considered equivalent to these. e numerical designations used:

Dempingsanordningen ifølge oppfinnelsen fungerer på følgende måte: Gjennom åpning A strømmer hydraulvæsken inn.og forårsaker en bevegelse i stempel 4 m.fl. sammen- - hengende komponenter i pilens retning. I det dempingshylsen 10 når strupelegemet 8, skjer strupning av hydraulvæske-strømmen. Trykkforskjellen som oppstår over strupelegemet?sider medfører at dette forskyves i pilens retning til det når den tettende overflaten på dempingsdelen 7,jd.v.s. mot den av utsparingens 27 sidevegger som ligger nærmest ut- - løpsåpning B. Idet denne stillingen nås, må gjenværende hydraulvæskemengde presses ut i spalten mellom strupelegemet 8 og dempingshylsen 10. Dette gir en effektiv demp-ing (retardering) av bevegelsen. I hylsen 10 kan det lages spor 30 som.utfreses slik at det dannes en voksende strup-' ning, hvilket gir en myk ,brenising. The damping device according to the invention works in the following way: Through opening A, the hydraulic fluid flows in and causes a movement in piston 4 etc. connected components in the direction of the arrow. When the damping sleeve 10 reaches the throttle body 8, the hydraulic fluid flow is throttled. The pressure difference that occurs across the sides of the throat means that this is displaced in the direction of the arrow until it reaches the sealing surface of the damping part 7, jd.v.s. against the one of the recess's 27 side walls which is closest to outlet opening B. When this position is reached, the remaining amount of hydraulic fluid must be forced out into the gap between the throttle body 8 and the damping sleeve 10. This provides an effective damping (retardation) of the movement. In the sleeve 10, a groove 30 can be made which is milled out so that a growing throat is formed, which gives a soft firing.

Når senere hydraulvæskens strømningsretning end-res og det utøves trykk på åpning B, påvirkes stempel-stempelstang i retning motsatt pilen. Fordi dette skjer, forskyves strupelegemet 8 mot sperringen 21 og åpner dermed veien for hydraulvæsken. Strupelegemet 8 har et antall utfreste (eller liknende) spor 28, som gir fri passasje for hydraulvæsken umiddelbart idet strupel;egemet for-- later den tettende overflaten hos delen 7, d.v.s. overflaten til utsparingen 27. When later the direction of flow of the hydraulic fluid is changed and pressure is exerted on opening B, the piston-piston rod is affected in the direction opposite to the arrow. Because this happens, the throttle body 8 is displaced towards the barrier 21 and thus opens the way for the hydraulic fluid. The throttle body 8 has a number of milled (or similar) grooves 28, which provide free passage for the hydraulic fluid immediately as the throttle body leaves the sealing surface of the part 7, i.e. the surface of the recess 27.

Prinsipielt fungerer dempingen i den andre enden på samme måte. Ved foreliggende oppfinnelse oppnås altså en ytterligere betraktelig forbedret anordning ved hvilker. en uten ekstra ventiler (overstrømnings- og tilbakeslags-ventiler) kan oppnå en endestillingsdemping, som på grunn av dempingslegemets og strupelegemets utforming :og plass-ering vokser (retarderingen øker) til å bli maksimal ved endestillingen og der sylinderen har full trykkraft alle-rede fra start i dempet stilling. Det oppstår altså ingen forstyrrende strupning av hydraulvæsken ved starit fra dempet stilling. In principle, the damping at the other end works in the same way. With the present invention, a further considerably improved device is thus achieved by which. one without additional valves (overflow and non-return valves) can achieve end-position damping, which due to the design and placement of the damping body and throttle body grows (retardation increases) to become maximum at the end position and where the cylinder already has full thrust from the start in a damped position. There is thus no disruptive throttling of the hydraulic fluid when starting from a damped position.

Claims

1. Device for postural damping of the moving ice of the piston with associated piston rod etc. components in a hydraulic cylinder, where next to one side of the piston is a damping body (10,29) which is attached to the piston and which along the circumference is equipped with a number of axial grooves (30,31) whose depth and/or width decreases in the direction against the piston (4), during a damping course with a certain play penetrates into an outlet channel in a cylinder end] or in a part (7) next to a cylinder end (5), as this channel forms an outlet for the pressurized hydraulic fluid in the cylinder space in front of the piston ( 4) and whereby in the opening of the outlet channel facing the piston, a recess (27) in the channel wall is occupied around the damping body (10,29) when it penetrates into the channel, in which recess an annular throttle body (8,9) is inserted with axial play, whereby the damping body (10,29) during the damping fqr stroke is arranged so that it passes through the throttle body (8,9), whereby this is first pressed by the hydraulic fluid against the side walls of the recess (2^) which are furthest away . from the piston (4) and thus restricts the throttling in the outlet of the hydraulic fluid mainly to the openings formed between the throttle body (8,9) and the grooves (30,31) exiting the damping body (10,29), as the throttle body (8,9) is an -

in order to prevent the return of the piston (4) from moving towards the open part of the recess (27) and thereby freeing the fluid for passage in the other direction to the piston (4), characterized in that the annular throat body (8,9) is designed with non-deformable cross-section and has a number of axially continuous grooves (28) occupied near the outer circumference, which provide free passage for the hydraulic fluid and whereby a groove with a inserted removable tracking ring (20,21), e.g. a so-called Seeger lock, which prevents the throat body (8,9) from leaving the recess (27) and whose inner diameter! is greater than the smallest diameter of the grooves (28) occupied in the throttle body (8,9), which enables free supply of hydraulic fluid to the piston during its return! and that the throat body (8,9) after removal of the tracking ring (20,21) can be taken out from the is inserted into the recess (27).

2. Device in accordance with claim 1, c al r a c t e r a c t i r e d in that the damping body up to one side of the piston (4) consists of a sleeve (10). which encloses the piston rod (2) and is suitably designed with a chamfered end. IN

3. Device in accordance with claim 1 or 2, characterized in that the damping body at the other end of the piston (4) is designed as a! cylindrical part (29) of the piston rod (2) itself, and which is designed with a chamfered end. j Device in accordance with any of the preceding requirements, characterized in that the opening: which ie the enclosure of the track ring (20,21) constitutes the only path for the hydraulic fluid during the passage to or from the space up to one side of the piston and that this opening is -in series with the grooves (28) which are occupied in the larynx (8>, 9) next to it. the grooves (30,31) which are possibly connected in parallel with these grooves and which are occupied in the damping body (10, 29) whereby the first grooves (28) upon the piston (4)'s return immediately enable the hydraulic fluid to exert full pressure on the piston (4), as soon as < larynx in (8,9) has left the plant towards one of the side walls of the recess as for the hydraulic fluid. is facing the connection opening (A and B respectively). in in