SE178197C1

SE178197C1 -

Info

Publication number: SE178197C1
Authority: SE
Publication date: 1961-01-01

Description

Uppfinnare: W P Mansfield Prioritet begerd fran den 11 november 1952 och den 3 juni 1953 (Storbritcuznien) Foreliggande uppfinning avser en forbranningsmotor med en cylinder och dari anbragta inlopps- och utloppsoppningar for instromning och utstr8mning av gaser till och fran cylindern. Uppfinningen kannetecknas av en kombination mellan dels en avgasdriven forkompressor, som matar cylindern med friskfyilning med ett tryck och i en mangd, som är beroende av motorns belastning oth varvtal, dels styrorgan, som oppna och stanga namnda oppningar vid sa avpassade och °foranderliga tidpunkter under motorns takter, att friskfyllningens volym vid i huvudsak det I cylindern med alla oppningar stangda radande tillforseltrycket ar vasentligt mindre an cylinderns totalvolym, och sa, att det effektiva kompressionsslaget är mindre an det effektiva expansionsslaget, samt dels en av forbranningstopptrycket i cylindern sa styrd omstallningsanordning for forandring av kompressionsrummets volym i cylindern, att forbranningstopptrycket Or i huvudsak konstant. Andamalet harmed ãr att denna kombination skall medfora att kompressionsforhallandet är foranderligt med ett mindre belopp an expansionsf8rhallandet f5r varje forandring av motorns belastning och varvtal, medan kompressionsforhallandet och den effektiva delen av kolvens kompressionsslag är mindre an expansionsforhallandet resp. kolvens expansionsslag. Inventor: W P Mansfield Priority Desired from 11 November 1952 and 3 June 1953 (Great Britain) The present invention relates to an internal combustion engine with a cylinder and inlet and outlet openings provided therein for the inflow and outflow of gases to and from the cylinder. The invention can be characterized by a combination between an exhaust-driven pre-compressor, which feeds the cylinder with fresh filling with a pressure and in an amount which depends on the engine load and speed, and control means, which open and close said openings at such adapted and variable times during the rate of the engine, that the volume of the fresh filling at substantially the radiating supply pressure in the cylinder with all openings is substantially less than the total volume of the cylinder, and that the effective compression stroke is less than the effective expansion stroke, and a changeover device controlled by the combustion peak pressure change in the volume of the compression chamber in the cylinder, that the combustion peak pressure Or is substantially constant. The purpose is that this combination should mean that the compression ratio is variable by a smaller amount than the expansion ratio for each change of the engine load and speed, while the compression ratio and the effective part of the piston compression stroke are smaller than the expansion ratio resp. piston expansion stroke.

Tidinstallningen av oppningarnas styrorgan sakerstaller att vid sugslaget tillforseln av friskluft i cylindern bringas att upphara genom stangningen av inloppet eller nagon speciell oppning, som kan sta oppen, nar kolven alltjamt har ett avsevart stycke att tillryggalagga f8r att na slutet av sitt kolvslag, varigenom friskluften expanderar i cylindern, innan den komprimeras pa nytt under kompres sionsslaget, eller nar vid kompressionsslaget den siststangande oppningen 1 cylindern stung-es, sedan kolven har tillryggalagt ett avsevart stycke av kolvslaget, varigenom en del av den friskluft som fanns i cylindern, nar kolven befann sig i sitt bortersta lage fran det skadliga rummet, fortranges tillbaka ut ur cylindern. Pit detta satt bibehalles i cylindern den luftfyllning, som shall komprimeras och delta I forbranningsprocessen, vid ett i huvudsak konstant varde och Or avsevart mindre an cylinderns totalvolym. Stangningen ay den sista 8ppning som shall stanga sker nar kolven befinner sig intill kolvslagets mitt. Del Or tydligt att de hada beskrivna anordningarna ge samma resultat, eftersom i det forsta fallet den inom cylindern expanderade och pa nytt komprimerade inloppsluften nar samma tryck och temperatur vid den likvarda punkt av kompressionsslaget i det andra fallet da friskluften infores i cylindern pa nu beskrivet satt. The timing of the opening means of the openings ensures that during the suction stroke the supply of fresh air in the cylinder is caused to cease by closing the inlet or any special opening which can stand open when the piston still has a considerable distance to travel to reach the end of its piston stroke, whereby the fresh air expands in the cylinder, before it is compressed again during the compression stroke, or when at the compression stroke the last opening in the cylinder is stung, after the piston has traveled a considerable distance of the piston stroke, whereby part of the fresh air present in the cylinder when the piston was in its farthest layer from the harmful space, is pushed back out of the cylinder. Pit this is maintained in the cylinder the air filling which is to be compressed and participate in the combustion process, at a substantially constant value and Or considerably less than the total volume of the cylinder. The closing at the last opening which is to close takes place when the piston is located next to the middle of the piston stroke. Part Or it is clear that the devices described had the same result, since in the first case the expanded and re-compressed inlet air within the cylinder reaches the same pressure and temperature at the equivalent point of the compression stroke in the second case when the fresh air is introduced into the cylinder as described .

En kylare kan vara anordnad fOr kylning av friskfyllningen efter dess komprimering medelst forkompressorn men fore dess inmatning i cylindern. A cooler may be provided for cooling the fresh filling after its compression by means of the pre-compressor but before its introduction into the cylinder.

Omstallningsanordningen for automatisk forandring av kompressionsrummets volym kan besta av en kolv, som in utford i tva huvuddelar, vilka mellan sig bilda minst en kammare, varvid dessa delar i och for forandring av kompressionsvolymen aro rorliga relativt varandra genom styrda rorelser av ett fluidum in i och ut ur namnda kammare under inverkan av gastryck och troghetskrafter. The adjusting device for automatic change of the volume of the compression space may consist of a piston which challenges two main parts, which between them form at least one chamber, these parts being movable relative to each other in order to change the compression volume by controlled movements of a fluid into and out of said chamber under the influence of gas pressure and inertial forces.

Genom att man anvander mindre an en cylinderfyllning mojliggores att omstallningsanordningen kan arbeta Over ett bredare omrade av kompressions- och expansionsforhallandena in som yore mojligt, darest en full cylinderfyllning anvandes, i det att den mins- 2— — kade fyllningen komprimeras till och expanderar fran en variabel kompressionsvolym. By using less than one cylinder fill, it is possible for the adjusting device to operate over a wider range of compression and expansion conditions as far as possible, where a full cylinder fill is used, in that the reduced fill is compressed to and expands from a variable compression volume.

Pa liknande salt medger tillampningen av omstallningsanordningen att den anvanda friskluftlyllningen, Aiken kan sta. under Mgt tryck, kan minskas till mindre mangd an den luftfyllning som är tillracklig vid en konstant kompressionsvolym, enar omstallningsanordningen for forandring av kompressionsvolymen tillforsakrar att den mindre luftfyllningen komprimeras och bringas att expanderh over ett bredare omrade f8r kompressionsforhallandet. Vid igangsattning och lag belastning av motorn komprimeras lagtrycksfyllningen Over ett stort kompressionsfOrhallande, varvid kompressionsvolymen Or ringa, vilket sakerstaller god forbranning, medan vid hog belastning hogtrycksfyllningen komprimeras Over ett lagtrycksforhallande och kompressionsvolymen darvid Or stor, varigenom alltfor hoga maximitryck undvikas. On similar salt, the application of the conversion device allows the used fresh air wool, Aiken can stand. under high pressure, can be reduced to a lesser extent than the air filling which is sufficient at a constant compression volume, the adjustment device for changing the compression volume ensures that the smaller air filling is compressed and caused to expand over a wider range for the compression ratio. During start-up and low load of the engine, the low-pressure filling is compressed over a large compression ratio, whereby the compression volume Or is small, which means good combustion, while at high load the high-pressure filling is compressed over a low-pressure ratio and the compression volume is thereby greatly avoided.

Kombinationen medfor dessutom att den fordelaktiga omstandigheten med mindre kompressionsforhallande On expansionsforhallande bibchalles Over motorns hela belastnings- och varvtalsomrade. The combination also means that the advantageous condition with less compression ratio On expansion ratio bibchalles Over the entire engine's load and speed range.

Kombinationen astadkommer ocksh att avgasdrivna forkompressorer arbeta mer effektivt, i det att den bridrar till att avpassa eller utbalansera den av avgasturbinen levererade effekten rued den av kompressorn avfordrade effekten. Turbokompressorn far salunda mojlighet att arbeta under sina mest effektiva betingelser for att avge en given mangd fyllning i form av en jamforelsevis ringa volym vid relativt Mgt tryck, vilket i sin tar leder till anvandning av mindre an en cylinderfyllning med jamforelsevis Mgt tryck snarare an till anvandning av en full cylinderfyllning vid relativt lagt tryck. The combination also ensures that exhaust-driven pre-compressors operate more efficiently, in that it bridges to adjust or balance the power delivered by the exhaust turbine to the power required by the compressor. The turbocharger thus has the opportunity to operate under its most efficient conditions to deliver a given amount of filling in the form of a comparatively small volume at relatively high pressure, which in turn leads to the use of less than a cylinder filling with comparatively high pressure rather than to use of a full cylinder filling at relatively low pressure.

Man finner salunda, hurusom oppningarnas tidsinstallning minskar den i cylindern kvarhallna volymen inloppsluft samt minskar kompressionsfarhallandet och salunda sambandet mellan dessa samt expansionsforhallandet och kolvslaget, valet sistnamnda forbIir oforandrat; medan variationen med avseende ph kompressionsvolymen forandrar bade expansions- och kompressionsforhallandena, men icke kolvslagen, och pa grund av skillnaden i effektiv volym mellan de bada kolvslagen forandras kompressionsforkallandet med ett mindre belopp On expansionsforhallandet. Vid alla delbelastningar, dar behovet av en forbattrad verkningsgrad Or storst, Ras kompressions- och expansionsfarhallandena, nar belastningen akar, till regleringsgriinsen for bibehalla.nde av maximalt forbranningstryck vid i huvudsak konstant varde. It is thus found that the time installation of the openings reduces the volume of inlet air retained in the cylinder and reduces the compression ratio and thus the relationship between these and the expansion ratio and piston stroke, the latter choice remains unchanged; while the variation with respect to the pH of the compression volume changes both the expansion and compression ratios, but not the piston types, and due to the difference in effective volume between the two piston types, the compression call changes with a smaller amount on the expansion ratio. At all sub-loads, where the need for an improved efficiency is greatest, the compression and expansion conditions, when the load increases, increase to the control limit for maintaining maximum combustion pressure at a substantially constant value.

Forsok ha visat att nar graden av forkompression akar, den avgasenergi som star till forfogande, nar motorn arbetar vid full belastning, Or storre On den som erfordras for att komprimera fyllningsluften till det tryck som vid fullt utnyttjande av kompressionsslaget ger det tillOtliga maximala eylindertrycket. Okningen av expansionsforhallandet icke blott akar motorns arbetseffekt Titan minskar darjamte avgasernas temperatur, vilket minskar forkompressorns tendens, nar den arbetar under full belastning, att avge mer luft an som erfordras for att uppratthalla motorns arbetseffekt. Attempts have shown that when the degree of pre-compression increases, the exhaust energy available when the engine is operating at full load, or greater than that required to compress the filling air to the pressure which, when fully utilizing the compression stroke, gives the maximum maximum cylinder pressure. Increasing the expansion ratio not only increases the engine's operating power Titan also reduces the temperature of the exhaust gases, which reduces the tendency of the pre-compressor, when operating under full load, to emit more air than is required to maintain the engine's operating power.

Metoden har den ytterligare fordelen, att en given kylvatska i en efterkylare kan utvinna mer varme fran luftfyllningen ph grund av den till ett hogre varde komprimerade fyllningen. Med ett givet cylindertryck vid slutet av det minskade effektiva kompressionsslaget Or salunda kompressionstemperaturen lagre och en storre luftvikt finnes i cylindern, si att en stone belastning kan tOlas, innan gransvardena for motorns temperatur uppnas. Darjamte minskas kolvens kompressionsarbete ytterligare. Alternativt kan en given grad av fyIlningskylning erhallas med en mindre efterkylare eller en kylvatska med hagre temperatur On vad som Or nadvandigt i normala fall. For att atervinna mer av avgasernas energi i form av energi i fyllningsluften kan verkningsgraden av turbo-forkompressionsprocessen forbattras genom anvandning av en efterkylare eller ett antal efterkylare melIan tva eller fler kompresssionssteg. The method has the further advantage that a given cooling liquid in an aftercooler can extract more heat from the air filling ph due to the filling being compressed to a higher value. With a given cylinder pressure at the end of the reduced effective compression stroke, the compression temperature is lower and a greater air weight is present in the cylinder, so that a stone load can be tolerated before the limit values for the engine temperature are reached. At the same time, the compression work of the piston is further reduced. Alternatively, a given degree of filling cooling can be obtained with a smaller aftercooler or a coolant with a higher temperature than is usual in normal cases. In order to recover more of the energy of the exhaust gases in the form of energy in the filling air, the efficiency of the turbo-compression process can be improved by using an aftercooler or a number of aftercoolers between two or more compression stages.

Bifogade ritningar visa som exempel nagra utforingsformer av uppfinningen. Ph rifflingarna visar fig. 1 ett axialsnitt genom en utforingsform av kolven. Fig. 2 visar ett mot fig. 1 vinkelrOtt axialsnitt genom samma kolv. Fig. 3 visar en planvy efter linjen A—A i fig. 1. Fig. 4 visar i aixalsnitt en kolv enligt en annan utforingsform. Fig. 5 Or en planvy, tagen langs linjen A—A i fig. 4. Fig. 6 och 7 visa axialsnitt av ett par ytterligare utforingsformer av kolven enligt uppfinningen. Fig. 8 visar schematiskt en med turbinkompression arbetande farbranningsmotor med kylare melIan kompressorn och motorcylindern. Fig. 9 visar schematiskt en med turbinkompression arbetande forbranningsmotor med kylare mellan tva kompressionssteg. Fig. 10 visar schematiskt en med turbinkompression arbetande forbranningsmotor med mekaniskt driven kompressor eller blasmaskin, avsedd sasom hjalpaggregat till avgasturbinkompressorn. Fig. 11 Or ett diagram, som visar forhallandet melIan tryck oeh volym for fyllningen i cylindern hos en motor, i vilken kvoten mellan ex.- pansionsforhallandet och kompressionsfarhallandet Or vasentligt storre On 1. Fig. 12 Or ett diagram, som visar forhallandet mellan fyllningens tryck och volym vid kompressionsslaget i cylindern under starten av en motor, i vii-ken kvoten mellan expansionsforhallandet och kompressionsforhallandet Or vasentligt star-re On 1. Fig. 13 dr ett diagram, som visar forhallandet mellan fyllningens tryck och yolym I cylindern till en motor, som arbetar med — —3 normalt forlopp under startfOrhallandena. Fig. 14 ar ett diagram, som visar forhallandet mellan fyllningens tryck och volym i cylin- dern hos en motor, som arbetar under startperioden med kvoten mellan expansionsforh5.1- landet och kompressionsforhallandet vasentligt storre an 1 och forsedd med en anordning for forandring av denna kvoi. The accompanying drawings show by way of example some embodiments of the invention. The corrugations show Fig. 1 an axial section through an embodiment of the piston. Fig. 2 shows an axial section perpendicular to Fig. 1 through the same piston. Fig. 3 shows a plan view along the line A-A in Fig. 1. Fig. 4 shows in axial section a piston according to another embodiment. Fig. 5 is a plan view, taken along the line A-A in Fig. 4. Figs. 6 and 7 show axial sections of a pair of further embodiments of the piston according to the invention. Fig. 8 schematically shows a turbine compression combustion engine with cooler between the compressor and the engine cylinder. Fig. 9 schematically shows an internal combustion engine operating with turbine compression with cooler between two compression stages. Fig. 10 schematically shows an internal combustion engine operating with turbine compression with a mechanically driven compressor or blowing machine, intended as an auxiliary unit for the exhaust turbine compressor. Fig. 11 Or a diagram showing the ratio between pressure and volume of the filling in the cylinder of an engine in which the ratio between the expansion ratio and the compression ratio Or is substantially larger On 1. Fig. 12 Or a diagram showing the ratio between the filling pressure and volume at the compression stroke of the cylinder during the start of an engine, at the ratio between the expansion ratio and the compression ratio , which works with - —3 normal course during the starting conditions. Fig. 14 is a diagram showing the relationship between the pressure and volume of the filling in the cylinder of an engine operating during the starting period with the ratio between the expansion ratio and the compression ratio substantially greater than 1 and provided with a device for changing it kvoi.

Vid ett utforande enligt uppfinningen finnes i varje cylinder i en forbranningsmotor av fyrtaktstyp en kolv enligt fig. 1, 2 och 3, utford av tva huvuddelar, vilka hada aro skalformade och med sina oppna andar vanda mot vevaxeln eller den eljest forefintliga anord- ningen for omvandling av kolvarnas framoch aterghende rorelse till rotationsrorelse. In an embodiment according to the invention, in each cylinder of a four-stroke internal combustion engine there is a piston according to Figs. conversion of the forward and rearward motion of the pistons into rotational motion.

Den ena kolvdelen Or anordnad inuti den andra. Den yttre skalformade delens 5 ?lyre dude eller valvda botten 6 bildar sjalva kolvbottnen och vander mot fOrbranningsrummet en yta av vanlig profil samt Or forsedd med kolvringar pa samma stallen som vanligt, medan den inre skalformiga kolvdelen 1 at axiellt forskjutbar inuti den yttre kolvdelen. Den inre delen 1 Or pa vanligt satt medelst en kolvbult 2 ansluten till vevstakens 4 lillande 3. Den yttre delens axialrorelse i forhallande till den inre delen astadkommer forandringar av cylinderns ovanfor kolvbottnen 6 belagna kompressionsvolym. En kammare 7 Or anordnad mellan den inre delens 1 oversida och kolvbottnens 6 undersida, medan en undre, ringformig kammare 8 bildas av en urtagning vid nedre anden av den inre sketlformade delens sidovagg. Inat och uppht begransas den nedre kammaren 8 av urtagningens hada ytor pa den inre kolvdelen, medan kammarens 8 yttersida begransas av insidan av den yttre holydelens mantel och kammarens undersida begransas av en cylindrisk, inatriktad ring 16 kring insidan av mantelns nedre ande. Denna ring Or lampligen gangad och inskruvad namnda mantels nedre ande, sa. att den kan insattas efter det att den inre kolvdelen har anbragts i sitt lage. Regleringen av rorelsen mellan kolvens inre och yttre d.elar sker med hjalp av olja, som strommar in i och ut ur den ovre kammaren 7 och den nedre, ringformiga kammaren 8. One piston part Or arranged inside the other. The outer shell-shaped part 5? Lyre dude or arched bottom 6 forms the piston bottom itself and faces the combustion chamber a surface of ordinary profile and Or provided with piston rings in the same place as usual, while the inner shell-shaped piston part 1 is axially displaceable inside the outer piston part. The inner part 1 Or in the usual way by means of a piston bolt 2 connected to the small shaft 3 of the connecting rod 4. A chamber 7 Or is arranged between the upper side of the inner part 1 and the lower side of the piston bottom 6, while a lower, annular chamber 8 is formed by a recess at the lower end of the side cradle of the inner shell-shaped part. Inwardly and upwards, the lower chamber 8 is bounded by the hot surfaces of the recess on the inner piston part, while the outer side of the chamber 8 is bounded by the inside of the outer hollow part jacket and the underside of the chamber is bounded by a cylindrical, aligned ring 16 around the inside of the lower end. This ring Or aptly threaded and screwed in the lower spirit of the said mantle, sa. that it can be inserted after the inner piston part has been fitted in its bearing. The movement between the inner and outer parts of the piston is regulated by means of oil, which flows into and out of the upper chamber 7 and the lower, annular chamber 8.

En oljekanal 9 Or anordnad i vevstaken 4 och f8rbinder ett tryeksmorjoljesystem med yttre vevstakslagret, varifran oljan gar genom en ringformig kanal 10 kring lagerhylsan till ett hal 10a i oversidan av vevstakens lillande. Alternativt kan den ringformiga kanalen, om kolvbulten Or fast anordnad vid vevstakens lillande och ingen lagerhylsa finnes, lopa kring kolybulten, eller ocksa kan ett hal vara anordnat genom kolvbulten. Yttersidan av denna ande av vevstaken Or utformad delvis cylindrisk och delvis sfarisk och ph densamma Or anpressat ett ihaligt organ 10b for att bilda en tatning omkring halet. Detta ihaliga organ ar med skjutpassning anbragt 1 ett uriag 1 undersidan av bottnen I det inre skalformiga organet och pressas av en fjader 10c till standig ber8ring med vevstakens ande. Alternativt kunna fixerade, mot varandra passande ytor vara anordnade med lampliga spelrum. Oljan strammar genom en axiell kanal 10d i det ihaliga organet till en backventil 11, Iran vilken oljan strommar och darifran till den ovre kammaren 7. Olja strommar Oven genom en annan backventil 12 och en kanal till den nedre kammaren 8. For att begransa det tryck, som i oljekamrarna ut8vas av oljans troghetskraft i vevstaken, sarskilt vid hoga motor-vandal, kan backventilernas lyftrorelse be- gransas, eller alternativt kunna tryckreducerings- .eller stryporgan (smala kanaler) vara anordnade pa lampliga stallen i oljekanalerna i kolven eller vevstaken pa vagen till hamrarna. An oil channel 9 is arranged in the connecting rod 4 and connects a pressure lubricating oil system to the outer connecting rod bearing, from which the oil passes through an annular channel 10 around the bearing sleeve to a slide 10a in the upper side of the crankcase. Alternatively, the annular channel, if the piston bolt Or is fixedly arranged at the crank of the connecting rod and no bearing sleeve is present, can run around the carbon fiber bolt, or a slide can also be arranged through the piston bolt. The outside of this spirit of the connecting rod Or is formed partly cylindrical and partly spherical and the same Or pressed a hollow member 10b to form a seal around the tail. This hollow member is slidably fitted to an underside of the bottom of the inner shell-shaped member and pressed by a spring 10c into constant contact with the spirit of the connecting rod. Alternatively, fixed, mating surfaces can be arranged with suitable clearances. The oil flows through an axial channel 10d in the hollow member to a non-return valve 11, Iran which the oil flows to and from there to the upper chamber 7. Oil flows above through another non-return valve 12 and a channel to the lower chamber 8. To limit the pressure , which in the oil chambers is exerted by the oil's inertia force in the connecting rod, especially at high engine vandal, the lifting movement of the non-return valves can be limited, or alternatively pressure reducing or throttling means (narrow channels) can be arranged in suitable positions in the oil channels in the piston or connecting rod. to the hammers.

Yttersida_n av den inre skalformiga delen har ett ringformigt spar, som bildas mellan den nedre kammaren och delens botten, varigenom tva radiella flansar 18 och 19 bildas, medan ett avlastningshal 17 Or anordnat i den inre delens sidovagg for att hindra att ett tryck bygges upp av olja, som lacker forbi flansarna, och som skulle kunna ut8va tryck ph hada kolvdelarnas vaggar. DO de bada kolvdelarnas vaggar kunna goras tillrackligt kraftiga for att motsta detta tryck, kunna avlastningshalet och namnda spar undvaras for att fOrbattra tatningen av den ovre och den nedre oljekammaren. The outer side of the inner shell-shaped part has an annular groove, which is formed between the lower chamber and the bottom of the part, whereby two radial flanges 18 and 19 are formed, while a relief hall 17 Or is arranged in the side cradle of the inner part to prevent a pressure from building up. oil, which varnishes past the flanges, and which could exert pressure on the cradles of the piston parts. DO the cradles of the two piston parts can be made sufficiently strong to withstand this pressure, the relief tail and the said grooves can be dispensed with in order to improve the sealing of the upper and lower oil chambers.

Tatningsringar kunna anvandas for att tillsluta de lackvagar, som bildas av spelrummen mcllan den inre och den yttre kolvdelen, sasom visas i fig. 4. Sealing rings can be used to close the paint waves formed by the clearances between the inner and outer piston parts, as shown in Fig. 4.

UtstrOmningen av olja ur den ovre kammaren sker genom en avlastningsventil, som innefattar laminerade cirkulara skivor 13 av fjaderstal, vilka kunna ha suceessivt avta Arbetssattet sker pa foljande satt: Under 4— — den senare delen av varje avgastakt och forsta delen av insugningstakten verkar kraften till foljd av den yttre kolvdelens troghet och trogheten hos oljan i den ovre kammaren, samt i viss utstrackning trogheten hos oljepeIaren i vevstaken, pa olj an i den nedre kammaren och bringar en del av denna att strain-ma ut genom utloppskanalerna, varigenom den. yttre kolvdelen forskjutes en mycket liten stracka (av storleksordningen 0,1 mm) uppat i forhallande till den inre kolvdelen. Samtidigt okas den ovre oljekammarens volym, och olja strommar in i densamma genom backventilen 11. Om motorbelastningen just har minskats, sa att maximitrycket är lagre an det som behi5vs for att lyfta avlastningsventilen, dvs. det tillstand, under vilket en alining av kompressionsfOrhallandet .erfordras, upprepas namnda forlopp under varje arbetstakt utan vidare, till dess det kompressionsfOrhallande uppnas, som gee det i forvag bestamda maximitryck, vid vilket avlastningsventilen oppnas. Genom den nasta lilla uppaigkende rorelsen tikas kompressionsforhallandet nagot Over det nodvandiga vardet, varfor det maximala cylindertrycket nagot overstiger det varde, som erfordras for att overvinna avlastningsventi1ens 13 tryck, vilken da oppnas och slapper ut en liten rnangd olj a, varigenom den yttre kolvdelen bringas rora sig nedat en liten stracka i forhallande till den inre kolvdelen. Om motorns belastning nu forblir konstant vid det laga vardet, fortsatter den. yttre kolvdelen att rora sig uppat och nedat i mycket ringa utstrackning i forhallande till den. inre kolvdelen under varje takt, varvid desssa delars inbordes medellage motsvarar det varde pa det maximala cylindertrycket, vilket bestammes av avlastningsventilens oppningstryck. The outflow of oil from the upper chamber takes place through a relief valve, which comprises laminated circular discs 13 of spring steel, which may have successively decrease. The mode of operation takes place as follows: followed by the inertia of the outer piston part and the inertia of the oil in the upper chamber, and to some extent the inertia of the oil column in the connecting rod, on oil in the lower chamber and causes part of it to strain out through the outlet channels, whereby it. the outer piston part is displaced by a very small distance (of the order of 0.1 mm) upwards in relation to the inner piston part. At the same time, the volume of the upper oil chamber increases, and oil flows into it through the non-return valve 11. If the engine load has just been reduced, then the maximum pressure is lower than what is needed to lift the relief valve, ie. the state under which an alignment of the compression ratio is required, said process is repeated during each work stroke without further ado, until the compression ratio is reached, which gives the predetermined maximum pressure at which the relief valve is opened. Due to the next small upward movement, the compression ratio is slightly increased above the required value, so that the maximum cylinder pressure slightly exceeds the value required to overcome the pressure of the relief valve 13, which then opens and releases a small amount of oil, thereby bringing the outer piston part down a small stretch in relation to the inner piston part. If the engine load now remains constant at the low level, it continues. outer piston part to move up and down to a very small extent in relation to it. the inner piston part during each stroke, the average layer of the inboard of these parts corresponding to the value of the maximum cylinder pressure, which is determined by the opening pressure of the relief valve.

Om motorns spj all nu oppnas, har eylindertrycket en tendens att okas avsevart Over det varde, som erfordras for att avlastningsventilen 13 skall oppnas, men da. denna ventil oppnas med en avsevard genomloppsarea, komrner olja Iran den ovre kammaren 7 att snabbt utstromma, sa att den yttre kolvdelen snabbt forskjutes nedat i forhallande till den inre kolvdelen och kompresssionsvolymen okas, varigenom maxinaalt cylindertryck bibehalIes mycket nara det forutbestamda vardet. If the engine speed is now opened, the cylinder pressure tends to increase considerably above the value required for the relief valve 13 to be opened, but then. this valve is opened with a considerable passage area, oil will cause the upper chamber 7 to flow out quickly, so that the outer piston part is rapidly displaced downwards in relation to the inner piston part and the compression volume is increased, whereby maximum cylinder pressure is maintained very close to the predetermined value.

Kolven installer sig salunda sjalv med begransad hastighet i beroende av en minskning av motorns beiastning, varvid denna hastighet bestammes av den area, som star till forfogande for laekning Iran den nedre kammaren. Det finnes intet behov av en snabb okning av kompressionsforhdllandet och dessutom skulle en star relativ uppatgaende rorelse av den yttre kolvdelen under varje takt joke vara Onskvard, emedan den vid konstant belastning skulle resultera i en lika stor nedatgaende rorelse under varje takt och darmed fororsaka en. betydande effektforlust genom oljans pum.pning. A andra sidan Or det onskvart att kolven sa snabbt som mojligt reagerar for en. plotslig Okning av bransletillforseln till ma-torn for att undvika alltfor hoga cylindertryck och darmed foljande knackning och/eller ga mekaniska spanningar. Omstallningshastigheten bestammes av avlastningsventilen 13. Den ovan beskrivna anordningen medf8r en mycket hog reaktionshastighet tack vare den. stora area, som vid en liten rorelse frilagges vid periferien, saint friheten fran differentialverkan, som gOr att vissa ventiltyper stangas vid ett tryck som är avsevart lagre an Oppningstrycket. The piston thus installs itself at a limited speed due to a reduction in the engine load, this speed being determined by the area available for healing the lower chamber. There is no need for a rapid increase in the compression ratio and moreover a star relatively upward movement of the outer piston part during each stroke would be a joke, since at constant load it would result in an equal downward movement during each stroke and thus cause one. significant power loss through oil pumping. On the other hand, it is unfortunate that the piston reacts as quickly as possible to one. sudden increase in fuel supply to the engine to avoid excessive cylinder pressures and consequent knocks and / or mechanical stresses. The conversion speed is determined by the relief valve 13. The device described above has a very high reaction speed due to it. large area, which in a small movement is exposed at the periphery, saint the freedom from differential action, which means that certain valve types are closed at a pressure which is considerably lower than the opening pressure.

Tills det beraknade minsta kompressionsforhallandet uppnatts, uppbares den av gastrycket paverkade kolvdelen pa olja i den Or-re kammaren 7, varfor gastrycket joke fOror: sakar nagra bOjningsspanningar i kolvbottnen, vilken endast tjanar till att skilj a gas en fran oljan. Kolvbottnen behOver darfor endast beraknas for att motstâ sin egen och oljans troghetsbelastningar, vilka hada verka densamma mot slutet av utblasningstakten och under fOrsta delen av insugningstakten. det beraknade minsta kompressionsforhallandet uppnas, vilar insidan av den. yttre kolvdelens batten pa lampliga ytor, anordnade pa oversidan av den inre kolvdelen. Until the calculated minimum compression ratio is reached, the piston part affected by the gas pressure is carried on oil in the Or-re chamber 7, for which reason the gas pressure jokes: there are no bending stresses in the piston bottom, which only serves to separate gas from the oil. The bottom of the piston therefore only needs to be calculated to withstand the inertial loads of its own and the oil, which would have had the same effect towards the end of the blow-out rate and during the first part of the intake rate. the calculated minimum compression ratio is reached, the inside of it rests. the outside of the outer piston part on suitable surfaces, arranged on the upper side of the inner piston part.

I stallet for den lamellbyggda avlastningsventilen 13 kunna fjaderbelastade ventiler 13 av forut kand typ vara anordnade i och omkring det inre skalformiga organets batten, sasom visas i fig. 4 och 5, varvid utstromning fran dessa ventiler sker direkt till rummet i den inre delen 1, varifran oljan avgar till motorns oljepump. Enligt fig. 4 tillfores kolvbottnen kylolj a genom en ihalig, central pelare eller tapp 24, som med ena anden ar fast vid den yttre kolvdelens botten och som Sr forskjutbar i en kanal i den inre kolvdelen 1. Olj an ledes genom denna tapp fran vevtappslagret 2 till radiella kanaler 26, som aro utformade mellan den yttre kolvdelens 5 batten. och en med radiella spar fOrsedd platta 25, vilken anligger mot insidan av denna batten och bildar den byre kammarens 7 Ovre begransningsvagg. De radiella kylkanalerna 26 leda oljan till ett ringformigt utrymme 28, i vilket olj an skakas fram och tillbaka och darigenom kyler den del av kolven, som upptager kolvringarna, varefter denna olja avgar till motorns oljesump genom kanalen 27. Instead of the lamella-built relief valve 13, spring-loaded valves 13 of the prior art type can be arranged in and around the batten of the inner shell-shaped member, as shown in Figs. from which the oil escapes to the engine oil pump. According to Fig. 4, the piston bottom is supplied with cooling oil through a hollow, central column or pin 24, which with one end is fixed to the bottom of the outer piston part and which is displaceable in a channel in the inner piston part 1. Oil is led through this pin from the crank bearing 2 to radial channels 26, which are formed between the bat of the outer piston part 5. and a plate 25 provided with radial grooves, which abuts against the inside of this batten and forms the upper boundary cradle of the barrel chamber 7. The radial cooling channels 26 lead the oil to an annular space 28, in which oil is shaken back and forth and thereby cools the part of the piston which receives the piston rings, after which this oil escapes to the engine oil sump through the channel 27.

Vid denna liksom vid den fOregaende konstruktionen Sr kolvbottnen fri fran bojningspakanningar, och gastryeket Overfores till oljan genom kolvbottnen och den med oljekanalen forsedda plattan samt astadkommer endast en komprimering av dessa delar. Foljaktligen kan kolvbottnen goras tunnare an vid den normala kolvkonstruktionen, och en given tillforsel av kylolj a kan da effektivare uppratthalla godtagbara temperaturer pa kolvbottnens mot forbranningsrummet vanda yta. In this case, as in the previous construction, the piston bottom is free from bending gaskets, and the gas is transferred to the oil through the piston bottom and the plate provided with the oil channel, and only a compression of these parts is effected. Consequently, the piston bottom can be made thinner than in the normal piston construction, and a given supply of cooling oil can then more efficiently maintain acceptable temperatures on the surface of the piston bottom towards the combustion chamber.

En. extra, stallbar utstromningsoppning 29 — — kan vara anordnad for att Oka stromningsarean for lackning frau den nedre oljekammaren, varigenom det blir mojligt att reglera kolvens atergangshastighet, dã belastningen upphor. One. extra, adjustable outflow opening 29 - - can be arranged to increase the flow area for lacquering from the lower oil chamber, whereby it becomes possible to regulate the return speed of the piston, when the load ceases.

Vid ett annat utforande, avsett att tillampas vid en tvatakts dieselmotor (fig. 6), är kolyens yttre del 5 utformad som en cylinder med en axiell kanal, i vilken den inre delen 1 ar axiellt forskjutbar. Kompressionsvolymen forandras med belastningsforandringarna. Kolvbottnens rorliga del innefattar en upp- och nedvand skhlformig del 1, som är forskjutbar i den cylindriska delens kanal och forsedd med en ring 30, som är anbragt i ett spar i de-lens 1 mantel och begransar delens 1 rorelse uppht. I den skalformiga delens 1 invandiga kanal är aven en tredje cylindrisk del 31 anordnad, vilken är med skjutpassning anbragt I delen 1 och bildar den undre begransningsvaggen for kammaren 7, som Or belagen melIan delens 31 oversida och insidan av bottnen pa den rorliga kolvdelen. Derma tredje del ar pa sin undersida bearbetad till lamplig form for att stodja mot den cylindriska eller sfariska yttersidan pa vevstakens lillande. Den tredje delen 31 Or fOrsedd med en skivliknande avlastningsventil 13 av det slag, som beskrivits for den forsta utforingsformen. Denna ventil tjanar till att slappa ut olj a frau oljekammaren 7 till sumpen, dâ oljetrycket overskrider ett valt varde, medan en backventil 32 Or anordnad mellan oljekammaren och oljetillforseln fran vevstakslagret. In another embodiment, intended to be applied to a two-stroke diesel engine (Fig. 6), the outer part 5 of the coal is formed as a cylinder with an axial channel, in which the inner part 1 is axially displaceable. The compression volume changes with the load changes. The movable part of the piston bottom comprises an upward and downward shell-shaped part 1, which is displaceable in the channel of the cylindrical part and provided with a ring 30, which is arranged in a groove in the jacket 1 of the part 1 and limits the movement of the part 1 upwards. A third cylindrical part 31 is also arranged in the inner channel of the shell-shaped part 1, which is arranged with a sliding fit in the part 1 and forms the lower boundary wall for the chamber 7, which is coated between the upper side of the part 31 and the inside of the bottom of the movable piston part. This third part is machined on its underside into a suitable shape to abut against the cylindrical or spherical outer surface of the connecting rod. The third part 31 Or is provided with a disc-like relief valve 13 of the type described for the first embodiment. This valve serves to release oil from the oil chamber 7 to the sump, when the oil pressure exceeds a selected value, while a non-return valve 32 Or is arranged between the oil chamber and the oil supply from the connecting rod bearing.

Vid denna tillampning pa en tvataktsmotor erfordras icke nagon undre oljekammare, emedan resultanten av de gas- och troghetskrafter, som verka pa den skalformiga delen och den tredje delen 31 alltid utgores av en nedat verkande kraft. Liksom i de foregaende fallen tillates nedatgaende riirelse av den skalformiga delen dd. cylindertrycket okas over gransvardet, genom att avlastningsventilen 13 oppnas. Kolvens uppatgaende rorelse astadkommes genom att olja under tryck passerar genom inloppsbackventilen 32 till kammaren 7. Detta kan vid ett for smorjoljesystem nor-malt arbetstryck ske under spolningsperioden, da gastrycket Or mycket lagt, emedan den skalformiga delens troghetsbelastning Or ringa. Den tredje kolvdelens 31 massa Or avsevdrt storre, men vid laga varvtal kan denna del lyftas obetydligt och darigenom tillata olj a fran vevstaken att bortga mellan lagringsytorna pa delen 31 och pa vevstaken. Detta innebar lake nagon olagenhet. En reglerbar stromningsbegransningsanordning kan vara anordnad i samband med en eller flera av oljetillforselkanalerna 33, 31 och 35 for att uppna lampliga genoms tromningsareor. In this application to a two-stroke engine no lower oil chamber is required, since the resultant of the gas and inertial forces acting on the shell-shaped part and the third part 31 always consist of a downward acting force. As in the previous cases, downward movement of the shell-shaped part dd is allowed. the cylinder pressure is increased above the threshold, by opening the relief valve 13. The upward movement of the piston is achieved by oil under pressure passing through the inlet check valve 32 to the chamber 7. This can occur with a lubricating oil system normal working pressure during the flushing period, when the gas pressure Or is very low, because the inertial part of the shell part is small. The mass of the third piston part 31 is considerably larger, but at low speeds this part can be lifted insignificantly and thereby allow oil from the connecting rod to move between the storage surfaces on the part 31 and on the connecting rod. This meant lake no trouble. An adjustable flow limiting device may be provided in connection with one or more of the oil supply channels 33, 31 and 35 to achieve lamps through the flow areas.

Forandringen i kompressionsfarhallandet kan saledes erhallas utan att astadkomma forandringar i tidsinstallningen for de av kolven tacIrta och frilagda oppningarna. The change in the compression ratio can thus be obtained without effecting changes in the time installation of the openings exposed by the piston.

Fig. 7 visar en anordning, vid vilken den backventil 12, soin reglerar oljestromningen till den nedre kammaren 8, dr anordnad inuti kolvbulten 2, medan oljetillforseln till den ovre kammaren 7 sker genom backventilen 11 och den stromningsbegransande oppningen i plattan eller skivan 11a for att begransa oljetillstromningen till den ovre kammaren. I ovrigt ar anordningen av vanligt slag och arbetar pa samma satt som ovan beskrivits i anslutning till fig. 1, 2 och 3. Fig. 7 shows a device in which the non-return valve 12 regulates the oil flow to the lower chamber 8, which is arranged inside the piston bolt 2, while the oil supply to the upper chamber 7 takes place through the non-return valve 11 and the flow restricting opening in the plate or disc 11a limit the oil inflow to the upper chamber. Otherwise, the device is of the usual type and operates in the same manner as described above in connection with Figs. 1, 2 and 3.

Alternativt kan i huvudsak samma resultat erhallas genom att gra vevstaken foranderlig till sin langd, varvid den eller de erforderliga oljekamrarna Oro forsedda med motsvarande back- och avlastningsventiler, alit efter vad som erfordras. Alternatively, substantially the same result can be obtained by making the connecting rod variable to its length, the required oil chamber (s) being provided with corresponding check and relief valves, alit as required.

Fig. 8 visar sasom exempel en schematisk sammanstallning av en motor med en avgasturbindriven kompressor 39 och en anordning, innefattande en motorkolv med rorlig botten 42 for att halla det maximala cylindertrycket vid ett ph forhand bestamt Mgt varde, Oven da belastningen är som lagst. Den erforderliga forkortningen av den verksamma kompressionstakten erhalles genom lampligt anordnande av tidpunktomstallningen for inlopps- och/eller avgasventilkroppen 43 resp. 44 pa ovan beskrivet sat, och motorn Or forsedd med en kylare 45 Indian kompressorn 39 och motorcylindern. Fig. 8 shows, by way of example, a schematic assembly of an engine with an exhaust gas turbine compressor 39 and a device, comprising an engine piston with a movable bottom 42 for maintaining the maximum cylinder pressure at a pH predetermined Mgt value, even when the load is at its lowest. The required shortening of the effective compression rate is obtained by appropriately arranging the timing changeover for the inlet and / or exhaust valve body 43 resp. 44 on the set described above, and the engine Or equipped with a radiator 45 Indian compressor 39 and the engine cylinder.

Fig. 9 visar sasoni exempel en sammanstallning av en motor, liknande motorn enligt fig. 8, med en tvastegskompressor 46 och en kylare 47 mellan dessa steg. Fig. 9 shows, for example, an assembly of an engine, similar to the engine of Fig. 8, with a two-stage compressor 46 and a cooler 47 between these stages.

DO det foreslagna kompressorsystemet tilllampas hos en tvataktsmotor, erhdllas samma fordelar som vid tillampning hos fyrtaktsmotorer, dvs. hog verkningsgrad vid laga belastningar och goda startegenskaper utan att ven:- tilernas tidpunktsomstallning behover andras. Genom den okade verkningsgraden sankes avgastemperaturen och -trycket, vilket i sin tur minskar den av turbinkompressorn avgivna luftvolymen. I nagra fall vid sma belastningar Or den av kompressorn avgivna luften icke tillracklig for att astadkomma effektiv spolning av motorcylindern, och i vissa fall kan en mekaniskt driven kompressor anvandas for att drivas i serie eller parallellt med den turbindrivna kompressorn. Fig. 10 visar schematiskt en tvataktsmotor, i vilken kvoten mellan expansionsforhallandet och kompressionsforhallandet Or vasentligt stiforre On 1 och som Or forsedd med en kolv 48 av ovan angiven typ samt med en mekaniskt driven kompressor 49, vilken Or kopplad i serie med kompressorn 50. DO the proposed compressor system is applied to a two-stroke engine, the same advantages are obtained as when applied to four-stroke engines, ie. high efficiency at low loads and good starting properties without the need to change the timing of the tiles. Due to the increased efficiency, the exhaust gas temperature and pressure are lowered, which in turn reduces the air volume emitted by the turbine compressor. In some cases at low loads the air delivered by the compressor is insufficient to effect efficient flushing of the engine cylinder, and in some cases a mechanically driven compressor may be used to operate in series or in parallel with the turbine driven compressor. Fig. 10 schematically shows a two-stroke engine, in which the ratio between the expansion ratio and the compression ratio Or is substantially stifor On 1 and which Or is provided with a piston 48 of the type indicated above and with a mechanically driven compressor 49, which Or is connected in series with the compressor 50.

Forhallandena mellan arbetsfluidets tryck och volym under motorns arbetstakter for oil- havisas i fig. 11-14. Fig. 11 visar en fordelaktig diagramform for full belastning, varvid expansionstakten Or langre On kompressisonstakten, vilket astadkommes 6— — genom reglering av ventilernas ventilperiod pa sadant satt, att trycket i cylindern joke okas narrinvart over kompressorns matningstryck A, tills kolven har rort sig till laget a i kompressionstakten, dar den aterstaende delen a, b av takten ãr avsevart kortare an expansionstakten d och e. En olagenhet med att driva en motor med denna ventilperiod Or att matningstrycket A vid turbinkompressorns start Jigger nara atmosfarstrycket B °eh att trycket i cylindern vid a Or i motsvarande grad lagt, sasom visas i fig. 12, varfar kompressionen Iran a till b icke ãr tillracklig for att tillforsakra tandning av branslet. En kand metod att overvinna denna brist Or att ;Wandra motorns ventilperiod sá, att kompressionstakten okas till samina langd som expansionstakten for startning och gang vid lag belastning. Tryck-volymdiagrammet blir da normalt sasom visas i fig. 13. Oct fordelaktiga tillstandet med kvoten mellan expansionsforhallandet och kompressionsforhallandet stone an 1 gar forlorat. The relationships between the pressure and volume of the working fluid during the engine's operating rates for oil are shown in Figs. 11-14. Fig. 11 shows an advantageous diagram form for full load, whereby the expansion rate Or longer On the compression rate, which is achieved 6 - by adjusting the valve period of the valves in such a way that the pressure in the cylinder jokes is increased narrin over the compressor supply pressure A layer at the compression rate, where the remaining part a, b of the rate is considerably shorter than the expansion rate d and e. a Or correspondingly laid, as shown in Fig. 12, the compression Iran a to b is not sufficient to ensure ignition of the branch. A well-known method of overcoming this shortcoming is to; The pressure-volume diagram then normally becomes as shown in Fig. 13. The advantageous state with the ratio between the expansion ratio and the compression ratio stone is lost.

DO motorn enligt uppfinningen Or forsedd med en anordning for andring av motorns kompression.svolyin uppnas god start och god gang vid lag belastning utan att man behover tillgripa varierbar ventilperiod och utan att man hehover avsta fran det viktiga villkoret, att kvoten mellan expansionsforhallandet och kompressionsfarhallandet skall vara storre On 1. Fig. 14 visor relationen mellan tryek och volym for fyllningen under start och lag belastning med denna anordning. DO the engine according to the invention Is provided with a device for changing the engine compression. be larger On 1. Fig. 14 shows the relationship between pressure and volume of the filling during start and low load with this device.

Kompressionen borjar IrAn ett tryck nara atmosfarstryeket vid punkten a, sedan kolven har utfort en avsevard del av sin slaglangd, men p0 grund av den minskade kompressionsvolymen uppna's full kornpressionstemperatur och fullt kompressionstryek, och forbranningen efterfoljes av expansion i mycket stort farhaliande. Den erforderliga fOrandringen av kompressionsvolymen kan uppn.as genom anvandning av de i fig. 1-7 beskrivna anordningarna. The compression starts a pressure near the atmospheric pressure at point a, after the piston has performed a considerable part of its stroke, but due to the reduced compression volume full grain compression temperature and full compression pressure is achieved, and the combustion is followed by expansion in very large range. The required change in the compression volume can be achieved by using the devices described in Figs. 1-7.

De nu beskrivna utfaringsformerna aro endast att betrakta som exempel, och detaljanordningarna kunna forandras ph manga satt utan att uppfinningstanken frangas. The embodiments now described are to be considered only as examples, and the detail devices can be changed in many ways without departing from the inventive concept.

Claims

Patentanspralo

A combustion engine with a cylinder (40) and then provided inlet and outlet openings for inflow and outflow of gases to and from the cylinder, characterized by a combination of an exhaust gas driven pre-compressor (39, 46, 50), which feeds the cylinder with fresh-filling with a try & and in a quantity, which Or depending on the engine load and speed, partly control means (43, 1-4), arranged to open and close the said openings at such adapted and invariable times during the engine speeds, that healthy -fill volume at essentially the In the cylinder with all openings sta.ngda, rowing supply pressure Or considerably within On cylinder total volume, and said that the effective grain compression stroke Or less On effective expansion stroke, as well as one of the combustion stop pressure in the cylinder so controlled adjustment device for changing the volume of the compression chamber in the cylinder, that the combustion peak pressure Or is substantially constant.

2. An internal combustion engine according to claim 1, characterized in that a cooler Or is provided for cooling the fresh filling after its compression by means of the pre-compressor but before its introduction into the cylinder.

Internal combustion engine according to claim 1 or 2, characterized in that the conversion device changes the volume of the compression chamber consists of a piston, which Or challenges in two main parts (1, 5), which between them form at least one chamber (7), these parts in and for change of the compression volume Agile relative to each other by controlled motions of a fluid into and out of said chamber under the influence of gas pressure and inertial forces. Request publications: Patent patent ter! Ran Sweden 17,878; France 798 013; Switzerland 217,848; United Kingdom 598,522; Germany 461450, 461963, 728904, 741563; U. S. A. 880825, 1 329 811, 2 097 883, 2 134 995, 2 169 243, 2 305 810. Stockholm 1962. Kungl. Boktr. P. A. Isforstedt & Semer. 620089 P1.1.