DK172217B1 - Piston for diesel engines - Google Patents

Piston for diesel engines Download PDF

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Publication number
DK172217B1
DK172217B1 DK90295A DK90295A DK172217B1 DK 172217 B1 DK172217 B1 DK 172217B1 DK 90295 A DK90295 A DK 90295A DK 90295 A DK90295 A DK 90295A DK 172217 B1 DK172217 B1 DK 172217B1
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DK
Denmark
Prior art keywords
piston
ribs
bores
cylindrical
refrigerant
Prior art date
Application number
DK90295A
Other languages
Danish (da)
Other versions
DK90295A (en
Inventor
Joern Dragsted
Original Assignee
Dampskibsselskabet Af 1912
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by Dampskibsselskabet Af 1912 filed Critical Dampskibsselskabet Af 1912
Priority to DK90295A priority Critical patent/DK172217B1/en
Priority to EP96610030A priority patent/EP0758715A1/en
Publication of DK90295A publication Critical patent/DK90295A/en
Application granted granted Critical
Publication of DK172217B1 publication Critical patent/DK172217B1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F02F3/0015—Multi-part pistons
    • F02F3/003—Multi-part pistons the parts being connected by casting, brazing, welding or clamping
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F02F3/0076—Pistons  the inside of the pistons being provided with ribs or fins
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F02F3/16—Pistons  having cooling means
    • F02F3/20—Pistons  having cooling means the means being a fluid flowing through or along piston
    • F02F3/22—Pistons  having cooling means the means being a fluid flowing through or along piston the fluid being liquid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/02—Engines characterised by their cycles, e.g. six-stroke
    • F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
    • F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F02F3/0015—Multi-part pistons
    • F02F3/003—Multi-part pistons the parts being connected by casting, brazing, welding or clamping
    • F02F2003/0061—Multi-part pistons the parts being connected by casting, brazing, welding or clamping by welding
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F2200/00—Manufacturing
    • F02F2200/04—Forging of engine parts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
    • F05C2201/00—Metals
    • F05C2201/04—Heavy metals
    • F05C2201/0433—Iron group; Ferrous alloys, e.g. steel
    • F05C2201/0448—Steel

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)

Description

DK 172017 B1DK 172017 B1

Opfindelsen angår et stempel til dieselmotorer, og som omfatter flere dele, der er sammenføjet ved hjælp af svejsning, og som er indrettet til at overføre forbrændingskræfter til en stempelstang.The invention relates to a piston for diesel engines, which comprises several parts which are joined by welding and which are adapted to transfer combustion forces to a piston rod.

5 Det er kendt at reducere godstykkelserne i toppen af et stempel og dermed godstemperaturerne ved at anvende ribber til understøtning af toppen. Der er i denne forbindelse tale om ud i ét støbte konstruktioner med radiale ribber eller kombinationer af radiale og cirkulære ribber. Det er karakteri-10 stisk for disse konstruktioner, at stemplets indvendige overflade ikke lader sig bearbejde eller kun kan bearbejdes med meget store omkostninger til følge, idet der kræves værktøjer, som kan komme ind i de trange hulrum, ligesom det er vanskeligt at fjerne spåner fra bearbejdningen. Dertil kom-15 mer, at materialekvaliteten kun vanskeligt lader sig kontrollere som følge af støbehuden og de dårlige adkomstforhold.5 It is known to reduce the thickness of the goods at the top of a piston and thus the goods temperatures by using ribs to support the top. In this context, these are in one molded structure with radial ribs or combinations of radial and circular ribs. It is characteristic of these designs that the inner surface of the piston cannot be machined or can only be machined at very high cost, requiring tools which can enter the narrow cavities, as is difficult to remove chips. from machining. In addition, the quality of the material can only be difficult to control due to the molding and the poor access conditions.

Til en række formål vil ubearbejdede indvendige overflader være tilstrækkelige, men i takt med, at motorydelsen ønskes forøget, stilles der større krav til overfladebeskaffenhed og 20 materialekvalitet for at sikre bedst mulig varmetransmission og udmattelsesstyrke. Dette betyder, at ud i ét støbte stempeltoppe med ribbeunderstøtninger bliver dyrere at fremstille. I forbindelse med mindre stempler til firetaktsmotorer er det kendt at fremstille stempeltoppen af flere dele, som be-25 arbejdes hver for sig og efterfølgende sammenføjes ved hjælp af elektronstrålesvej sning.For a variety of purposes, unworked interior surfaces will suffice, but as engine performance is desired to increase, greater demands are made on surface texture and material quality to ensure the best possible heat transmission and fatigue strength. This means that in one molded piston top with rib supports becomes more expensive to manufacture. In connection with smaller pistons for four-stroke engines, it is known to produce the piston top of several parts, which are machined separately and subsequently joined together by electron beam welding.

Formålet med opfindelsen er at tilvejebringe et stempel, som er velegnet til brug til især store totaktsdieselmotorer, og som forholdsvis billigt lader sig fremstille.The object of the invention is to provide a piston which is suitable for use in especially large two-stroke diesel engines and which is relatively inexpensive to manufacture.

30 Dette opnås ifølge opfindelsen ved, at stemplet har en central ud i ét tildannet del, som er indrettet til at blive fast forbundet med stempelstangen, og som omfatter en cylindrisk central væg, der strækker sig koaksialt med stemplets 2 DK 172017 B1 midterakse, radialt fra den centrale væg udragende ribber, der i alt væsentligt strækker sig i radiale planer, der indeholder stemplets midterakse, og en stempeltop, der som en endevæg for den cylindriske centrale væg og mellemrummene 5 imellem de radiale ribber strækker sig ud til området i umiddelbar nærhed af ribbernes ydre ender, og at stemplet har en yderste cylindrisk del, som er forsynet med udvendige rundt-gående ribber til optagelse af tætningsringe, og som ved den øvre ende er forbundet med stempeltoppens ydre periferi ved 10 hjælp af svejsning.This is achieved according to the invention in that the piston has a central part in one formed part which is arranged to be fixedly connected to the piston rod and which comprises a cylindrical central wall extending coaxially with the center axis of the piston, radially ribs extending from the central wall substantially extending in radial planes containing the center axis of the piston, and a piston top extending as an end wall of the cylindrical central wall and the spaces 5 between the radial ribs extending into the immediate vicinity. the outer end of the ribs, and that the piston has an outer cylindrical portion which is provided with outer circumferential ribs for receiving sealing rings and which is connected at the upper end to the outer periphery of the piston tip by welding.

Herved opnås et enkelt opbygget stempel, hvis dele let lader sig bearbejde i et ønsket omfang og derefter sammenføje ved svejsning, såsom elektronstrålesvejsning. Den centrale del vil alene overføre forbrændingskræfterne til stempelstangen, 15 dels via den cylindriske understøtning nærmest centrum og dels via de herfra udgående radiale ribber i forbindelse med stempeltoppen. De radiale ribbers udstrækning, tykkelse og antal afpasses efter den forventede motorbelastning. Den acceptable stempeltoptykkelse kan opnås ved bearbejdelse med 20 traditionelle skærende værktøjer, og spåner kan let fjernes.Hereby a single constructed piston is obtained, the parts of which are easily machined to a desired extent and then joined together by welding, such as electron beam welding. The central portion will only transfer the combustion forces to the piston rod, 15 partly via the cylindrical support closest to the center and partly via the radial ribs extending therefrom in connection with the piston top. The extent, thickness and number of the radial ribs are adjusted to the expected engine load. The acceptable piston thickness can be obtained by machining with 20 traditional cutting tools and chips can be easily removed.

Også materialekvaliteten lader sig let kontrollere overalt, idet adkomstforholdene er gode. Herved opnås væsentlige omkostningsmæssige fordele i forhold til traditionelle med ribber tildannede stempler samt en særdeles stor forøgelse af 25 sikkerheden for, at materialekvaliteten modsvarer specifikationerne. Ribbernes antal kan være forholdsvis stort, idet der ikke skal tages hensyn til minimumkrav for støbekerners tykkelse, således som det er tilfældet i forbindelse med traditionelle støbte stempeltoppe. Dette indebærer, at stempel-30 toppens tykkelse kan reduceres yderligere trods samme spændingsniveau .The quality of the material is also easily controlled everywhere, as the access conditions are good. This provides significant cost advantages over traditional rib-shaped pistons as well as an extremely large increase in the certainty that the material quality meets the specifications. The number of ribs can be relatively large, taking into account minimum requirements for the thickness of the casting cores, as is the case with traditional molded pistons. This means that the thickness of the piston 30 can be further reduced despite the same voltage level.

Ved at tildanne stemplet af en ud i ét tildannet central del og en ydre cylindrisk del, som derefter svejses sammmen ved hjælp af f.eks. elektronstrålesvejsning, opnås at der kan an-35 vendes forskellige materialer til fremstillingen af de for- 3 DK 172017 B1 skellige dele. Den yderste cylindriske del kan være af et hærdbart materiale, såsom ulegeret stål med et højt kulstof-indhold, medens den centrale del kan være fremstillet af et mere varmebestandigt materiale, såsom en speciel legering, 5 f.eks. Cr-Mo-stål. Hvis den yderste cylindriske del ikke er fremstillet af et tilstrækkeligt slidstærkt materiale, vil overfladen i de rundtgående ringspor passende være Cr-belag-te. De to dele kan imidlertid også være fremstillet af ens materialer og derved svejses sammen ved traditionel svejs-10 ning.By forming the piston of an integrally formed central part and an outer cylindrical part, which are then welded together by e.g. electron beam welding, it is achieved that different materials can be used to make the various parts. The outermost cylindrical portion may be of a hardenable material such as a high carbon content of non-alloy steel, while the central portion may be made of a more heat resistant material such as a special alloy, e.g. Cr-Mo steel. If the outer cylindrical portion is not made of a sufficiently durable material, the surface of the circumferential ring grooves will suitably be Cr coated. However, the two parts may also be made of identical materials and thereby be welded together by conventional welding.

Det er også kendt at fremstille stempler med indre kanaler til cirkulation af kølemiddel. I modsætning til traditionelt ubearbejdede, ribbede stempler med stempeltoppen støbt ud i ét kan der ved hjælp af stemplet ifølge en første udførelses-15 form for opfindelsen iværksættes en effektiv køling af toppen, hvis der i hvert ribbemellemrum er fastgjort en ledeplade, som afgrænser et øverste, nærmest stempeltoppen værende øvre kølerum, og den indre ende af hvert af disse kølerum er i åben forbindelse med den cylindriske centrale vægs indre 20 via gennemgående boringer heri, og den yderste cylindriske dels nedre ende har en aflukningsindretning til tætsluttende aflukning af området omkring den centrale del over for omgivelserne. Ved hjælp af sådanne ledeplader sikres der effektiv køling af bagsiden af stempeltoppen. Ledepladerne fastgøres 25 passende til ribberne ved hjælp af svejsning eller skruer. Kombinationen af radiale ribber, hvis funktion primært er bærende, men også varmeledende, sikrer optimale strømningsforhold for det varmeoverførende kølemiddel og muliggør, at stempeltoppen kan fremstilles med de mindst mulige gods-30 tykkelser. Aflukningsindretningen dannes passende af et stempelskørt, som tjener til styring af stemplet i en omgivende foring.It is also known to produce pistons having internal ducts for circulating refrigerant. In contrast to traditionally unworked, ribbed pistons with the piston top molded in one, an effective cooling of the top can be effected by means of the piston according to a first embodiment of the invention if a baffle plate defining a top is secured in each rib spacing. , the upper cooling compartment being closest to the piston top, and the inner end of each of these cooling compartments is openly connected to the inner 20 of the cylindrical central wall via through bores herein, and the lower end of the outer cylindrical portion has a closure device for tightly sealing the area around the central share towards the surroundings. Such baffles ensure efficient cooling of the back of the piston top. The guide plates are securely fastened to the ribs by welding or screws. The combination of radial ribs, whose function is primarily load-bearing but also heat-conductive, ensures optimum flow conditions for the heat-transferring refrigerant and enables the piston top to be manufactured with the least possible thicknesses. The closure device is suitably formed by a piston skirt which serves to guide the piston in a surrounding casing.

Ifølge en anden udførelsesform for opfindelsen kan der i ribberne findes boringer, som strækker sig fra den centrale vægs 35 indre til ribbernes ydre ender, og som er indrettet til at 4 DK 172017 B1 lede kølemiddel frem til eller væk fra de ydre ender af de øvre kølerum. Herved sikres der effektiv styring af strømmen af kølemiddel, således at denne kommer til at virke effektivt overalt på bagsiden af stempeltoppen og de tilstødende dele 5 af stemplet. Alternativt kan der ifølge en tredje udførelsesform for opfindelsen findes boringer i stempelstangen til at lede kølemidlet væk fra stemplets indre.According to another embodiment of the invention, bores may be provided in the ribs extending from the interior of the central wall 35 to the outer ends of the ribs, which are adapted to direct refrigerant to or away from the outer ends of the upper walls. cold room. This ensures effective control of the flow of refrigerant so that it will work effectively everywhere on the back of the piston top and the adjacent parts 5 of the piston. Alternatively, according to a third embodiment of the invention, bores can be found in the piston rod to guide the refrigerant away from the interior of the piston.

Særligt hensigtsmæssigt kan ifølge en fjerde udførelsesform for opfindelsen stempelstangen have et centralt aksialt hul, 10 hvori der er monteret en ledeindretning til at lede kølemiddel frem til og væk fra de respektive sæt af boringer.Particularly conveniently, according to a fourth embodiment of the invention, the piston rod may have a central axial hole 10 in which a cooling device is provided for conducting refrigerant up to and away from the respective sets of bores.

En effektiv styring af strømmen af kølemiddel til og fra det øvre kølerum opnås, hvis ifølge en femte udførelsesform for opfindelsen der ved ribbernes ydre ender er monteret en 15 rundtgående cylindrisk ring, hvis øvre ende befinder sig i niveau med endepladernes ydre ender og er tætsluttende forbundet hermed samt med de mellemliggende dele af ribberne, og der i ringen findes et hul ud for hver boring i ribberne.An efficient control of the flow of refrigerant to and from the upper cooling compartment is achieved if, according to a fifth embodiment of the invention, a circular cylindrical ring is mounted at the outer ends of the ribs, the upper end of which is aligned with the outer ends of the end plates and is tightly connected. herewith as well as with the intermediate portions of the ribs, and in the ring there is a hole next to each bore in the ribs.

Særligt enkelt kan ifølge en sjette udførelsesform for opfin-20 delsen ledeindretningen omfatte et rør, som er placeret koak-sialt med stempelstangen og har en rundtgående flange, hvormed den støder op til den indvendige side af den centrale dels cylindriske centrale væg imellem de respektive sæt af boringer.In particular, according to a sixth embodiment of the invention, the guide device may comprise a tube coaxially positioned with the piston rod and having a circumferential flange with which it abuts the inner side of the central part's cylindrical central wall between the respective sets. of bores.

25 Opfindelsen forklares nærmere nedenfor under henvisning til tegningen, hvor fig. 1 viser en del af et aksialt snit igennem en udførelsesform for et stempel ifølge opfindelsen, monteret på enden af en stempelstang, hvoraf der kun er vist en del, 30 fig. 2 et snit efter linien II-II i fig. 1, og 5 DK 172017 B1 fig. 3 en del af en anden udførelsesform for den centrale del af stemplet ifølge opfindelsen, set i aksialt snit monteret på enden af en stempelstang.The invention is explained in more detail below with reference to the drawing, in which fig. 1 shows a portion of an axial section through an embodiment of a piston according to the invention, mounted on the end of a piston rod, of which only a portion is shown; FIG. 2 is a sectional view taken along line II-II of FIG. 1 and 5 DK 172017 B1 fig. 3 shows a part of another embodiment of the central part of the piston according to the invention, seen in axial section mounted on the end of a piston rod.

Det i fig. 1 og 2 viste stempel, som er forsynet med det ge-5 nerelle henvisningstal 1, omfatter en central del, som er forsynet med det generelle henvisningstal 2, og en yderste cylindrisk del, som er forsynet med det generelle henvisningstal 3. Den centrale del 2 omfatter en cylindrisk central væg 4 ud fra hvilken, der strækker sig radiale ribber 5, som 10 i alt væsentligt strækker sig langs radiale planer, der indeholder stemplets midterakse 6. Foroven, set i forhold til fig. 1, har den centrale del 2 en stempeltop 7, som danner en endevæg for den cylindriske centrale væg 4 og mellemrummene imellem ribberne 5 og strækker sig ud til området i umiddel-15 bar nærhed af ribbernes 5 ydre ender. Stempeltoppen har på almindelig kendt måde en nærmest skålformet form med en fordybning ved midten ned imod stempelstangssiden.The FIG. 1 and 2, provided with the general reference numeral 1, includes a central portion provided with the general reference numeral 2 and an outer cylindrical portion provided with the general reference numeral 3. The central portion 2 comprises a cylindrical central wall 4 from which extends radial ribs 5, which extend substantially along radial planes containing the center axis 6 of the piston as seen in relation to FIG. 1, the central portion 2 has a piston top 7 which forms an end wall of the cylindrical central wall 4 and the spaces between the ribs 5 and extends to the region in the immediate vicinity of the outer ends of the ribs 5. The piston top has a generally bowl-shaped shape with a recess at the middle down towards the piston rod side in a generally known manner.

Den cylindriske centrale væg 4, de radiale ribber 5 og stempeltoppen 7 er tildannet ud i ét, idet de er fremstillet ved 20 støbning eller smedning af et passende materiale og bearbejdet efter ønske. Imellem ribberne 5 er der fastgjort ledeplader 8, som har et forløb, der er i alt væsentligt parallelt med stempeltoppen 7. Disse ledeplader 8, som er fastgjort på ikke nærmere vist måde ved svejsning eller fastskruning, af-25 grænser et øvre kølerum 9, som er beliggende imellem stempeltoppen 7 og den enkelte ledeplade 8. Hvert kølerum 9 er forbundet med den cylindriske centrale vægs inderside ved hjælp af en gennemboring 10 og ligger ellers åben ud til området omkring ribberne ved ledepladernes 8 ydre ender, set i radial 30 retning. Som vist ved hjælp af punkterede linier, er der derudover tildannet en boring 11 igennem hver ribbe strækkende sig fra den cylindriske centrale vægs 4 indvendige side ved den længst væk fra stempeltoppen 7 beliggende ende til et område tæt ved ledepladerne 8, men i niveau under disse, set 35 i retning væk fra stempeltoppen 7.The cylindrical central wall 4, the radial ribs 5 and the piston top 7 are formed integrally as they are made by casting or forging a suitable material and machined as desired. Between the ribs 5, baffles 8 are mounted which have a course substantially parallel to the piston top 7. These baffles 8, which are fixed in a not shown manner by welding or screwing, define an upper cooling chamber 9, located between the piston top 7 and the individual baffle 8. Each cooling compartment 9 is connected to the inside of the cylindrical central wall by means of a bore 10 and is otherwise open to the area around the ribs at the outer ends of the baffles 8, seen in radial 30 direction. In addition, as shown by dashed lines, a bore 11 is formed through each rib extending from the inner side of the cylindrical central wall 4 at the farthest end of the piston top 7 to a region close to the baffles 8, but at a level below these. , seen 35 in the direction away from the piston top 7.

6 DK 172017 B16 DK 172017 B1

Den centrale del 2 er fastgjort til den yderste cylindriske del ved hjælp af elektronstrålesvejsning ved 12. Den yderste cylindriske del 3 har på den udvendige side rundtgående spor 12, 13, 14, 15, og 15' hvori der i de fire sidstnævnte er 5 anbragt tætningsringe 16, 17, 18 og 18' på almindelig kendt måde. Det øverste spor 12 tjener til fastgribning af et løfteværktøj. Umiddelbart ud for ledepladernes 8 ydre ender har den yderste cylindriske del en rundtgående fordybning 19 i indervæggen.The central portion 2 is secured to the outermost cylindrical portion by electron beam welding at 12. The outermost cylindrical portion 3 has on its outer side circumferential grooves 12, 13, 14, 15, and 15 'in which the four latter are arranged 5 sealing rings 16, 17, 18 and 18 'in a generally known manner. The upper groove 12 serves to grasp a lifting tool. Immediately beyond the outer ends of the guide plates 8, the outer cylindrical portion has a circumferential recess 19 in the inner wall.

10 Stemplet 1 er fastgjort på enden af en stempelstang 20 via den centrale del 2, således at den centrale cylindriske væg 4 og ribberne 5 støder direkte an imod stempelstangen 20 og understøttes af denne. Hertil er ribberne 5 tildannet med en aksialt udragende forhøjning 21 ved deres ydre ender til 15 anlæg imod stempelstangens 20 udvendige periferi. Fastgørelsen til stempelstangen kan foregå på almindelig kendt måde ved hjælp af bolte, således som vist skematisk ved 22.The piston 1 is secured to the end of a piston rod 20 via the central portion 2 such that the central cylindrical wall 4 and the ribs 5 abut directly against the piston rod 20 and are supported by it. To this end, the ribs 5 are formed with an axially extending projection 21 at their outer ends for abutment 15 against the outer periphery of the piston rod 20. The fastening to the piston rod can be carried out in a generally known manner by means of bolts, as shown schematically at 22.

Ved den nedre længst væk fra stempeltoppen 7 beliggende ende er den yderste cylindriske del forsynet med et ringformet 20 stempelskørt 23, som også fungerer som en aflukningsindretning, som er fastgjort ved hjælp af bolte 24, og som ligger tætsluttende an imod stempelstangens 20 udvendige periferi. Imellem aflukningsindretningen 23 og stempelstangen 20 er der anbragt en tætningsring 25. Aflukningsringen 23 er således 25 dimensioneret, at den under brug ligger styrende an imod cylinderens indvendige side.At the lower furthest away from the piston top 7, the outer cylindrical portion is provided with an annular 20 piston skirt 23, which also acts as a closure device which is secured by bolts 24 and which seals closely against the outer periphery of the piston rod 20. Between the closure device 23 and the piston rod 20, a sealing ring 25. A sealing ring 23 is dimensioned such that it is in use guiding it towards the inside of the cylinder during use.

Stempelstangen 20 er tildannet med et centralt aksialt hul 26, hvori der er anbragt en rørformet ledeindretning 27, som strækker sig koaksialt med stempelstangen og ved den øvre 30 ende har en påsvejset flange 28 til fastgørelse af ledeindretningen 27 på en række af fremspring 29, som er tildannet på enden af stempelstangen 20 rundt langs kanten af hullet 26. Disse fremspring 29 er således placeret, at der imellem fremspringene 29 er fri passage ind til boringerne 11 igennem 7 DK 172017 B1 ribberne 5. Ledeindretningen 27 er fastgjort til stempelstangen ved hjælp af bolte 30 og ligger tæt an imod den indvendige side af den centrale cylindriske væg 4 i området imellem mundingerne ind til de to sæt af boringer 10 og 11, der lig-5 ger adskilt fra hinanden i aksial retning. For at lette fastgørelsen af ledeindretningerne 27 har flangen 28 en rundtgå-ende udsparing 31 til optagelse af fremspringene 29.The piston rod 20 is formed with a central axial hole 26, in which is arranged a tubular guide device 27 which extends coaxially with the piston rod and at the upper 30 has a welded flange 28 for attaching the guide device 27 to a series of projections 29 which is formed on the end of the piston rod 20 around the edge of the hole 26. These projections 29 are positioned so that between the projections 29 there is free passage into the bores 11 through the ribs 5. The guide device 27 is attached to the piston rod by means of bolts 30 and adjoin the inner side of the central cylindrical wall 4 in the region between the orifices to the two sets of bores 10 and 11 which are spaced apart in axial direction. To facilitate the attachment of the guide devices 27, the flange 28 has a circumferential recess 31 for receiving the projections 29.

Ved brug af stemplet ledes der kølemiddel ind til stemplet via stempelstangen 20 langs den udvendige side af ledeindret-10 ningen 27, således som vist ved hjælp af en pil 32. Herfra strømmer kølemidlet, som vist ved hjælp af en pil 33, igennem boringerne 11 frem til den indvendige side af den yderste cylindriske del 3 ved fordybningen 19. Herfra strømmer det, som vist ved hjælp af en pil 34, op imod stempeltoppen 7 og 15 tilbage radialt indad, som vist ved hjælp af en pil 35, igennem kølerummene 9 for til sidst at strømme igennem boringerne 10 ind til det indre af den centrale del 2, hvorfra det strømmer bort igennem det indre af ledeindretningen 27, som vist ved hjælp af en pil 36. Den beskrevne styring af strøm-20 men af kølemiddel sikrer, at de dele af stemplet, der udsættes for de højeste temperaturer, dvs. området omkring stempeltoppens 7 periferi hurtigt tilføres nyt kølemiddel, som hurtigt fjernes igen, således at der sikres god køling og dermed mulighed for anvendelse af en særlig tynd stempeltop 25 7.Using the plunger, refrigerant is introduced into the plunger via piston rod 20 along the outside of guide device 10, as shown by an arrow 32. From here, the refrigerant, as shown by an arrow 33, flows through the bores 11 to the inner side of the outer cylindrical portion 3 at the recess 19. From here, as shown by means of an arrow 34, it flows back radially inwards, as shown by means of an arrow 35, through the chambers 9, as shown by an arrow 35. finally flowing through the bores 10 into the interior of the central portion 2, from which it flows away through the interior of the guide device 27, as shown by an arrow 36. The described control of the flow of refrigerant ensures that the parts of the piston exposed to the highest temperatures, i.e. the area around the periphery of the piston top 7 is quickly added to new refrigerant, which is quickly removed again, thus ensuring good cooling and thus the possibility of using a particularly thin piston top 25 7.

I stedet for boringerne 11 kunne der være anbragt boringer 37, som er vist ved hjælp af punkterede linier, igennem stempelstangen 20, hvorved kølemidlet ledes centralt op igennem ledeindretningen 27 og radialt ud igennem kølerummene 9 og 30 derfra ned i bunden af stemplet og ind til stempelstangens 20 indre igen via boringerne 37.Instead of the bores 11, bores 37, which are shown by dotted lines, could be arranged through the piston rod 20, whereby the refrigerant is guided centrally up through the guide device 27 and radially out through the cooling rooms 9 and 30 from there into the bottom of the piston and into the the interior of the piston rod 20 again via the bores 37.

Som vist i fig. 3, hvor dele svarende til dem, der er vist i fig. 1 og 2, er forsynet med samme henvisningstal, kan der rundt langs ribbernes ydre periferi være monteret en rundtgå-As shown in FIG. 3, wherein parts similar to those shown in FIG. 1 and 2, provided with the same reference numerals, there may be mounted around the outer periphery of the ribs.

Claims (7)

8 DK 172017 B1 ende cylindrisk ring 38, som er tætsluttende forbundet med ledepladerne 8 ved dens øvre nærmest stempeltoppen 7 værende ende. I ringen 38 er der huller 39 ud for boringerne 11 igennem ribberne 5. Ved hjælp af denne ring 39 sikres der yder-5 ligere effektiv styring af strømmen af kølemidlet frem til kølerummene 9 umiddelbart under stempeltoppen 7 samt enklere montage af ledepladerne, idet disse kan være forbundet med ringen 38 for monteringen imellem ribberne 5. Opfindelsen er blevet beskrevet under henvisning til fore-10 trukne udførelsesformer. Der kan foretages mange ændringer, uden at man herved afviger fra opfindelsens idé.8 cylindrical ring 38 which is tightly connected to the baffles 8 at its upper end closest to the piston top 7. In the ring 38, holes 39 are provided for the bores 11 through the ribs 5. This ring 39 further ensures effective control of the flow of the refrigerant to the cooling rooms 9 immediately below the piston top 7 and easier mounting of the baffles, which can The invention has been described with reference to preferred embodiments. Many changes can be made without departing from the idea of the invention. 1. Stempel til dieselmotorer, og som omfatter flere dele (2, 15 3) , der er sammenføjet ved hjælp af svejsning, og som er ind rettet til at overføre forbrændingskræfter til en stempelstang (20), kendetegnet ved, at stemplet (1) har en centralt ud i ét tildannet del (2) , som er indrettet til at blive fast forbundet med stempelstangen (20) , og som om- 20 fatter en cylindrisk central væg (4), der strækker sig koak-sialt med stemplets midterakse (6), radialt fra den centrale væg udragende ribber (5), der i alt væsentligt strækker sig i radiale planer, der indeholder stemplets (1) midterakse (6), og en stempeltop (7), der som en endevæg for den cylindriske 25 centrale væg (4) og mellemrummene imellem de radiale ribber (5) strækker sig ud til området i umiddelbar nærhed af ribbernes (5) ydre ender, og at stemplet (1) har en yderste cylindrisk del (3) , som er forsynet med udvendige rundtgående ringspor (13, 14, 15 og 15') til optagelse af tætningsringe 30 (16, 17, 18 og 18'), og som ved øvre ende er forbundet med stempeltoppens (7) ydre periferi ved hjælp af svejsning.Piston for diesel engines, comprising a plurality of parts (2, 15 3) joined by welding and adapted to transfer combustion forces to a piston rod (20), characterized in that the piston (1) has a centrally formed part (2) formed to be fixedly connected to the piston rod (20) and comprising a cylindrical central wall (4) extending coaxially with the center axis of the piston ( 6), radially projecting ribs (5) extending substantially in radial planes containing the center axis (6) of the piston (1) and a piston top (7) which acts as an end wall for the cylindrical 25 the central wall (4) and the spaces between the radial ribs (5) extend to the area in the immediate vicinity of the outer ends of the ribs (5) and the piston (1) has an outer cylindrical portion (3) which is provided with external circular grooves (13, 14, 15 and 15 ') for receiving sealing rings 30 (16, 17, 18 o g 18 ') and connected at the upper end to the outer periphery of the piston top (7) by welding. 2. Stempel ifølge krav 1, og hvori der findes kanaler til cirkulation af kølemiddel, kendetegnet ved, at der 9 DK 172017 B1 i hvert af ribbemellemrummene er fastgjort en ledeplade (8), som afgrænser et øverste nærmest stempeltoppen (7) værende øvre kølerum (9) , og at den indre ende af disse kølerum (9) er i åben forbindelse med den cylindriske centrale vægs (4) 5 indre via gennemgående boringer (10) heri, og at den yderste cylindriske dels (3) nedre ende har en aflukningsindretning (23) til tætsluttende aflukning af området omkring den centrale del (2) over for omgivelserne.Piston according to claim 1, wherein there are channels for circulating refrigerant, characterized in that a guide plate (8) is defined in each of the rib spacers defining an upper cooling chamber (7) which is closest to the piston top (7). (9) and that the inner end of these cooling compartments (9) is openly connected to the inner of the cylindrical central wall (4) via through bores (10) therein, and that the lower end of the outer cylindrical part (3) has a closure device (23) for tightly sealing the area around the central portion (2) towards the surroundings. 3. Stempel ifølge krav 2, kendetegnet ved, at der 10 i ribberne (5) findes boringer (11), som strækker sig fra den centrale vægs (4) indre til ribbernes (5) ydre ender, og som er indrettet til at lede kølemiddel frem til eller væk fra de ydre ender af de øvre kølerum (9).Piston according to claim 2, characterized in that bores (11) are provided in the ribs (11) which extend from the interior of the central wall (4) to the outer ends of the ribs (5) and which are arranged to guide refrigerant up to or away from the outer ends of the upper cooling compartments (9). 4. Stempel ifølge krav 2 eller 3, kendetegnet 15 ved, at der findes boringer (37) i stempelstangen til at lede kølemiddel væk fra stemplets (1) indre.Piston according to claim 2 or 3, characterized in that bores (37) are provided in the piston rod to direct refrigerant away from the interior of the piston (1). 5. Stempel ifølge krav 2, 3 eller 4, kendetegnet ved, at stempelstangen (20) har et centralt aksialt hul (26), hvori der er monteret en ledeindretning (27) til at lede kø- 20 lemiddel frem til og væk fra de respektive sæt af boringer henholdsvis (10 og 11).Piston according to claim 2, 3 or 4, characterized in that the piston rod (20) has a central axial hole (26) in which is mounted a guide device (27) for passing refrigerant up to and away from the respective sets of bores, respectively (10 and 11). 6. Stempel ifølge krav 2, 3 eller 4, kendetegnet ved, at der ved ribbernes (5) ydre ender er monteret en rundtgående cylindrisk ring (38), hvis øvre ende befinder sig 25. niveau med ledepladernes (8) ydre ender og er tætsluttende forbundet hermed samt med de mellemliggende dele af ribberne, og at der i ringen (38) findes et hul (39) ud for hver boring (11) i ribberne (5).Piston according to claim 2, 3 or 4, characterized in that at the outer ends of the ribs (5) is mounted a circumferential cylindrical ring (38), the upper end of which is at a level 25 with the outer ends of the guide plates (8) and is tightly connected thereto as well as with the intermediate portions of the ribs, and that in the ring (38) there is a hole (39) next to each bore (11) in the ribs (5). 7. Stempel ifølge krav 5, kendetegnet ved, at 30 ledeindretningen (27) omfatter et rør, som er placeret koak- sialt med stempelstangen og har en rundtgående flange (28) , hvormed den støder op til den indvendige side af den centrale 10 DK 172017 B1 dels (2) cylindriske centrale væg (4) imellem de respektive sæt af boringer (henholdsvis 10 og 11). 5Piston according to claim 5, characterized in that the guide device (27) comprises a pipe coaxially positioned with the piston rod and has a circumferential flange (28) with which it abuts the inner side of the central 10 DK. 172017 B1 partly (2) cylindrical central wall (4) between the respective sets of bores (10 and 11, respectively). 5
DK90295A 1995-08-11 1995-08-11 Piston for diesel engines DK172217B1 (en)

Priority Applications (2)

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DK90295A DK172217B1 (en) 1995-08-11 1995-08-11 Piston for diesel engines
EP96610030A EP0758715A1 (en) 1995-08-11 1996-08-12 A piston for diesel engines

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Application Number Priority Date Filing Date Title
DK90295 1995-08-11
DK90295A DK172217B1 (en) 1995-08-11 1995-08-11 Piston for diesel engines

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DK172217B1 true DK172217B1 (en) 1998-01-05

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US6740912B1 (en) 1999-06-24 2004-05-25 Agere Systems Inc. Semiconductor device free of LLD regions
ATE272167T1 (en) * 2000-05-17 2004-08-15 Baschieri & Pellagri TWO-STROKE INTERNATIONAL ENGINE WITH INCREASED EFFICIENCY AND LOW TOXIC Emission
DE10047258C2 (en) * 2000-09-23 2003-02-06 Ks Kolbenschmidt Gmbh Piston with ring section supported and welded onto the base part
KR101706751B1 (en) 2016-09-30 2017-02-27 삼영기계 (주) High preassure piston crown
JP2022066724A (en) * 2020-10-19 2022-05-02 株式会社ジャパンエンジンコーポレーション Liquid cooling type piston and cross head type internal combustion engine
CN113374593A (en) * 2021-06-30 2021-09-10 东风商用车有限公司 Piston connecting rod structure and internal combustion engine

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FR1531024A (en) * 1966-07-12 1968-06-28 Burmeister & Wains Mot Mask Improvements relating to pistons, in particular for internal combustion engines
CH496882A (en) * 1968-09-20 1970-09-30 Sulzer Ag Liquid-cooled piston of a reciprocating internal combustion engine
DK123730B (en) * 1970-10-23 1972-07-24 Burmeister & Wains Mot Mask Piston for internal combustion engines.
DE2730071A1 (en) * 1977-07-02 1979-01-04 Maschf Augsburg Nuernberg Ag MULTI-PIECE PISTON FOR COMBUSTION MACHINERY
US4502422A (en) * 1982-12-27 1985-03-05 General Motors Corporation High output oil cooled floating piston

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