DK146345B

DK146345B - VIP ARM AND TURNING MECHANISMS FOR STEP-TURN TURNING VALVES IN COMBUSTION ENGINES

Info

Publication number: DK146345B
Application number: DK90279A
Authority: DK
Inventors: Jordan Gentscheff
Original assignee: Maschf Augsburg Nuernberg Ag
Priority date: 1978-03-14
Filing date: 1979-03-05
Publication date: 1983-09-12
Also published as: DK146345C; FR2420030A1; DK90279A; DE2810956C2; DE2810956A1; FR2420030B1; JPS54126813A

Description

i 146345in 146345

Opfindelsen angår en vippearms- og drejningsmekanisme til trinvis drejning af tallerkenventiler i forbrændingsmotorer ved hjælp af pi ventilerne anbragte, med en under tryk stiende smøremiddelstrøm påvirkelige løbeskovie, som er anbragt pi ventilskaftet oven over 5 ventilføringen.BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a rocker arm and pivot mechanism for stepwise rotation of plate valves in internal combustion engines by means of the p valves arranged with a pressurized lubricant flow running vane arranged in the valve shaft above the valve guide.

Fra DE-patentansøgning P 21 19 596 kendes allerede en ventil, som pi sin i gasvekselkanalen indragende del har i forhold til strømningen skråtstillede løbeskovie.From DE patent application P 21 19 596, a valve is already known which has a slanting bushing which is inclined in the gas exchange channel in relation to the flow.

De i gasvekselkanalen indragende løbeskovie udgør imidlertid 10 en strømningsmodstand, som hæmmer gasstrømningen, hvorved virknings graden af en efterfølgende turbine i en udstødsgasturbolader formindskes.However, the running shovel projecting into the gas exchange channel constitutes a flow resistance which inhibits the gas flow, thereby reducing the efficiency of a subsequent turbine in an exhaust gas turbocharger.

Pi grund af den varme udstødsgas er de forholdsvis tynde løbeskovie også udsat for slid som følge af vaxmekorrosion, hvorfor 15 der pi grund af den yderligere stødpivirkning og den høje strømningshastighed af udstødsgassen er risiko for, at dele af løbeskovlene brækker af og kan føre til beskadigelse af turbinen i den efterfølgende udstødsgasturbolader.Due to the hot exhaust gas, the relatively thin running blades are also subject to wear due to wax corrosion, which is why due to the additional shock effect and the high flow velocity of the exhaust gas, parts of the running blades break down and can lead to damage of the turbine in the subsequent exhaust gas turbocharger.

Endvidere afhænger også det til ventilen overførte drejnings-20 moment meget af motorens øjeblikkelige belastningstilstand. Der er derfor ikke sikkerhed for en drejning i delbelastningsomrldet. Dette gælder også ved drift ved fuld belastning, hvis de i gasstrømmen indragende løbeskovie er formindsket pi grund af korrosion.Furthermore, the torque transmitted to the valve also depends greatly on the instantaneous load condition of the motor. Therefore, there is no certainty of a rotation in the partial load range. This also applies to operating at full load if the running coves entering the gas stream are reduced due to corrosion.

Da fremstillingsomkostningerne for ventiler med pisvejste 25 eller pikrympede løbeskovie er forholdsvis høje, bliver den regelmæssige, på grund af slid nødvendige udskiftning af ventilerne dyr.As the manufacturing costs of valves with pitch welded 25 or pitch-shrunk running stoves are relatively high, the regular replacement of the valves due to wear is expensive.

I modsætning hertil har den foreliggende opfindelse til opgave at tilvejebringe en enkel vippearms- og drejningsmekanisme, som uafhængigt af forbrændingsmotorens belastningstilstand udøver et 30 konstant drejningsmoment pi ventilen i åbningsintervallet, og som ikke medfører nogen strømningsmodstand i gasvekselkanalen.In contrast, the present invention has the object of providing a simple rocker arm and pivot mechanism which independently of the combustion engine load condition exerts a constant torque at the valve in the orifice interval and which does not cause any flow resistance in the gas exchange channel.

Ifølge opfindelsen løses denne opgave ved, at smøremiddelstrømmen føres gennem en i hvert fald i ventilens åbningsinterval mod løbeskovlene rettet dyse, som er fast anbragt pi den ventilen 35 aktiverende vippearm.According to the invention, this task is solved by passing the lubricant flow through a nozzle at least in the opening interval of the valve towards the running vanes, which are fixedly mounted on the valve 35 activating rocker arm.

Fortrinsvis har vippearmen en fra dysen til den drejningsfaste vippearmsaksel førende boring, som i en til ventilens åbnings- 2 146345 interval svarende vinkelstilling af vippearmen er i forbindelse med en i vippearmsakslen radialt forløbende boring, som er afgrenet fra en i vippearmsakslen udformet central boring, som fører smøremiddel under tryk. Man opnår derved, at løbeskovlene kun påvirkes med en 5 smøremiddelstråle under Ibningsfasen, hvorved smøremiddelkredsløbet kun skal afgive den til drejning af ventilen nødvendige energi. En forringelse af virkningsgraden af andre funktionselementer, fx. af udstødsgasturboladeren, er herved udelukket.Preferably, the rocker arm has a bore leading from the nozzle to the pivotal rocker shaft which, in an angular position corresponding to the valve's opening opening, is in communication with a bore radially extending in the rocker shaft, which is branched from a central drill shaft formed in the rocker shaft. applies lubricant under pressure. This results in that the running blades are only affected by a 5 lubricant jet during the Ibening phase, whereby the lubricant circuit must only supply the energy required for turning the valve. A decrease in the efficiency of other functional elements, e.g. of the exhaust gas turbocharger is hereby excluded.

Hensigtsmæssigt er løbeskovlen anbragt pi et med ventil-10 skaftet drejningsfast forbundet turbinehjul. Turbinehjulet kan være udløseligt fastgjort pi ventilskaftet. Denne foranstaltning har den fordel, at der ved fremstillingen kan anvendes enkle og dermed billigt udskiftelige ventiler, som ikke behøver nogle specielle yderligere foranstaltninger til anbringelse af vippearms- og drej-15 ningsmekanismen. Der kan let anbringes turbinehjul med forskellige diametre, hvorved man let kan variere drejningsmomentet.Conveniently, the impeller is mounted on a turbine wheel connected to the valve shaft which is rotatably fixed. The turbine wheel may be releasably attached to the valve shaft. This measure has the advantage that simple and thus cheaply replaceable valves can be used in the manufacture, which do not need any special additional measures for applying the rocker arm and pivot mechanism. Turbine wheels with different diameters can easily be placed, which makes it possible to vary the torque easily.

I en yderligere fordelagtig udformning af opfindelsen er turbinehjulets løbeskovie udformet af hovedsagelig aksialt forløbende boringer, som er anbragt ved turbinehjulskivens omkreds, og hvis 20 diameter er større end differensen mellem turbinehjulets udvendige diameter og diameteren af den cirkel, på hvilken boringernes centre ligger.In a further advantageous embodiment of the invention, the running shovel of the turbine wheel is formed of mainly axially extending bores disposed at the circumference of the turbine wheel, the diameter of which is greater than the difference between the outside diameter of the turbine wheel and the diameter of the circle on which the centers of the bores lie.

Opfindelsen skal i det følgende forklares nærmere under henvisning til tegningen, pi hvilken 25 fig- 1 viser et snit af en vippearms- og drejnings mekanisme ifølge opfindelsen set fra siden, og fig. 2 en udførelsesform for et turbinehjul, som påvirkes af en smøremiddelstrøm fra en dyse, 30 set fra oven.BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained in greater detail below with reference to the drawing, in which: FIG. 1 is a side view of a rocker arm and pivot mechanism according to the invention; 2 shows an embodiment of a turbine wheel which is affected by a lubricant flow from a nozzle, 30 seen from above.

I fig. 1 er vist en ventil 1, som ved hjælp af en ventilføring 2 er lejret i en forbrændingsmotors topstykke. Ventilen 1 aktiveres mod virkningen af en ventilfjeder 4 ved hjælp af en 35 vippearm 5, hvis ene ende indvirker pi ventilen 1, og hvis anden ende er påvirket af en stødstang 6. Vippearmen 5 er lejret pi en hul fast aksel 7, som gennemstrømmes af smøremiddel under tryk, og som har en 146345 3 radialt forløbende boring 8. Denne boring 8 er i den til den åbne stilling af ventilen 1 svarende vinkelstilling af vippearmen 5 i forbindelse med en i denne anbragt boring 9, som fører ud gennem en dyse 10. I forbindelsesstillingen af de to boringer 8,9 er dysen 10 5 rettet mod løbeskovlene 12 i et turbinebjul 11, som er drejningsfast anbragt ved den øvre ende af ventilen 1. Pi undersiden af turbinehjulet 1 findes et aksialleje 13, mod hvilket ventilfjederen 4 støtter.In FIG. 1, a valve 1 is shown which, by means of a valve guide 2, is mounted in the head of an internal combustion engine. The valve 1 is actuated against the action of a valve spring 4 by means of a 35 rocker arm 5, one end of which acts on the valve 1 and the other end is actuated by a thrust rod 6. The rocker arm 5 is mounted on a hollow fixed shaft 7 which is flowed by pressurized lubricant having a radially extending bore 8. This bore 8 is in the angular position of the rocker arm 5 corresponding to the open position of the valve 1 in connection with a bore 9 disposed therein which extends through a nozzle 10 In the connecting position of the two bores 8,9, the nozzle 10 5 is directed to the running blades 12 of a turbine shaft 11 which is pivotally mounted at the upper end of the valve 1. In the underside of the turbine wheel 1 there is an axial bearing 13 against which the valve spring 4 supports. .

I fig. 2 er vist en udførelsesform for turbinehjulet 11, hvis 10 løbeskovie 12 dannes if de mellemrum, som fremkommer mellem udad åbne boringer 14.In FIG. 2, an embodiment of the turbine wheel 11 is shown, whose 10 running bucket 12 is formed in the spaces that appear between outwardly open bores 14.

Under ventildrejemekanismens drift er forbindelsen mellem boringerne 8 og 9 afbrudt i den til ventilens lukkestilling svarende vinkelstilling af vippearmen. Når vippearmen 5 vippes ved hjælp af 15 stødstangen 6, bringes ventilen 1 i åbningsstillingen. Samtidig kommer boringerne 8 og 9 i indburdes forbindelse, si at den i akslen 7 værende, under tryk stående smøreolie gennem disse boringer 8,9 strømmer til dysen og træder ud fra denne i form af en stråle 15, som påvirker turbinehjulet 11's løbeskovie 12. Derved sættes den med 20 turbinen 11 fast forbundne ventil i omdrejning, idet den er frit drejeligt understøttet mod ventilfjederen 4 ved hjælp af det under turbinehjulet 11 anbragte aksialleje 13.During the operation of the valve switching mechanism, the connection between bores 8 and 9 is interrupted in the angular position of the rocker arm corresponding to the valve closing position. When the rocker arm 5 is tilted by means of the thrust bar 6, the valve 1 is brought into the opening position. At the same time, the bores 8 and 9 come into contact with each other, so that the lubricating oil present in the shaft 7 through these bores 8,9 flows to the nozzle and exits therefrom in the form of a beam 15 which affects the running bucket 12 of the turbine wheel 11. Thereby, the valve connected to the turbine 11 is turned in rotation, being freely pivotally supported against the valve spring 4 by means of the axial bearing 13 located below the turbine wheel 11.

Vippearms- og drejningsmekanismen ifølge opfindelsen er således praktisk taget ikke udsat for slid. Den påvirkes kun i 25 ventilens åbningsstilling med strømningsmiddel under sikring af et konstant drejningsmoment.Thus, the rocker arm and pivot mechanism of the invention is practically not subject to wear. It is actuated only in the opening position of the valve with flow means while ensuring a constant torque.