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
  • F02F1/00—Cylinders; Cylinder heads 
  • F02F1/004—Cylinder liners
• • 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
  • F02F1/00—Cylinders; Cylinder heads 
  • F02F2001/008—Stress problems, especially related to thermal stress

Definitions

• the invention relates to a cylinder liner for covering the cylindrical wall of a cylinder of an internal combustion engine and to a cylinder block of an internal combustion engine having at least one cylinder equipped with such a cylinder.
• cylinder liner In its most general form, an internal combustion engine, or heat engine, comprises a motor unit in which is formed at least one cylinder inside which is mounted mobil a piston connected by a connecting element such as a link, to a crankshaft.
• the engine block comprises three main parts, one of which is called cylinder block (s), because it comprises one or more cylinders.
• cylinder block s
• the single spelling block "cylinders" is adopted without this should exclude from the invention the engines having a single cylinder.
• the cylinder block is covered on one side with a cylinder head (second main part) in which are arranged the means necessary for the operation of the internal combustion, in particular intake means, exhaust means and possibly means for ignition.
• a crankcase in which is housed a crankshaft (third main part).
• the engine block comprises at least one cylinder delimited by a straight cylindrical wall inside which can translate a piston connected by a connecting rod at the crankshaft.
• the cylinder head comprises, for the cylinder or for each of the cylinders, the distribution means, for example at least one intake valve, at least one exhaust valve and possibly a spark plug, as well as mechanical means for controlling the valves.
• the crankcase contains the crankshaft and connecting rod and the oil tank needed to lubricate the engine.
• the sealing between the three main parts of the combustion engine, namely between the cylinder block and the cylinder head respectively and the crankcase is provided by gaskets. More particularly, the upper seal, that is to say the seal between the cylinder block and the cylinder head, is provided by a cylinder head gasket specially designed for this purpose.
• this operation will always include, for each of the cylinders, a step of admission of fuel and air necessary for combustion, a step of compressing the fuel / air mixture, an internal combustion stage of the fuel / air mixture and a step of exhausting the burned fuel. These four stages are organized, by an adequate architecture of the combustion engine, in two or four cycles.
• the deformations are generally related to the dynamic stresses due to the thermodynamic cycles. But they are also due to the prestressing forces due to the clamping loads of the cylinder head and the cap housing covering the cylinder head.
• the cylinder liner may be stationary or movable, and when stationary, it may be permanently attached in the cylinder block or removable.
• the present invention relates to a fixed cylinder liner, but possibly removable for the cladding of the cylindrical wall of a cylinder of an internal combustion engine.
• the advantage of the design of an internal combustion engine having a jacketed cylinder cylinder block is to be able to benefit from both a light and flexible engine and rigid cylinders and in particular sufficiently hard to resist the friction of the piston.
• This sealing is provided by means of a head gasket made, for example, from several superposed metal sheets.
• the cylinder head gasket is able to seal between the cylinder block and the cylinder head with a predetermined flexibility that can be exerted in an axial direction of the cylinder.
• the fact of making the cylinder block in two materials namely the cylinder block itself of a light and relatively soft alloy and the cylinder or cylinder liners in a heavy and hard material, also causes problems. different thermal behaviors of the two components of the cylinder block.
• the thermal behavior requires particular attention when designing the cylinder block, since the cooling of the cylinder block, by air or by liquid, is more or less easy to implement depending on the dimensions of the cylinder block and the number and of the arrangement of the cylinders.
• the upper edges of the cylinder liners are at a lower level with respect to a plane determined by the contact surface of the cylinder block with the cylinder head. Accordingly, in such a situation, the seal of cylinder head rests essentially, if not exclusively, on the body of the lightweight metal cylinder block.
• each of the cylinder liners causes an extraordinary pressure on the bridge formed by the part of the cylinder block situated between two neighboring cylinders.
• the compression exerted on this part of the cylinder block contributes in its way to the fragility of the cylinder block.
• Another major disadvantage is the expansion of this part itself, forming the bridge between two neighboring cylinders. This expansion exerts a strong pressure first on the cylinder head gasket due to the plasticization of the metal in this part of the cylinder block.
• this expansion exerts a strong pressure on the two neighboring shirts to "create” the space necessary for its expansion. Deformation of the cylinder liners mistletoe resulting is very detrimental to the contact between the inner walls of the shirts and the corresponding pistons.
• the plasticity of the metal particularly when it is aluminum, can be at the origin of slots forming between the jackets and the cylinder block, which hampers the tightness of the cylinder head gasket.
• a particularly stressed space on this subject and particularly critical as regards the question of whether the cylinder block withstands thermal stresses, is the space between two neighboring cylinders.
• the cylinder liners have the general shape of a straight cylindrical tube having an inner wall for guiding a piston in translation and an outer wall intended to take bearing on the cylindrical wall of the constituent recess of the cylinder.
• the inner and outer walls of the liner are substantially co-cylindrical, not necessarily cylindrical of rotation, and delimit between them an upper edge of the liner for receiving at least a portion of a cylinder head gasket.
• the object of the invention is to propose a solution for overcoming the disadvantages mentioned above. More particularly, the object of the invention is to propose an improvement of the jacketed cylinders.
• the object of the invention is achieved with a cylinder liner for the cladding of the cylindrical wall of a cylinder of an internal combustion engine, the liner having an inner wall for guiding a piston in translation and a outer wall intended to bear on the cylindrical wall of the recess constituent of the cylinder, the inner and outer walls of the cylinder liner being substantially co-cylindrical and delimiting between them an upper edge of the liner for receiving at least a portion of a cylinder head gasket.
• the outer wall of the cylinder liner comprises an upper portion flaring towards the upper edge of the liner.
• This arrangement of the invention makes it possible at the same time to retain the traditional design of a cylinder liner covering the cylindrical wall of a cylinder of an internal combustion engine with the necessary distances between two neighboring cylinders, and the need for obtain a contact surface of the cylinder block towards the breech as homogeneous as possible.
• the cylinder liner is a tubular element whose cross section is no longer constant over its entire height, but which is provided with a widening by flaring or any other form of expansion of the outer wall of the cylinder liner, in an annular zone terminating at the upper edge of the liner. Thanks to this design of the invention, the average distance required between two neighboring cylinders is maintained over most of the height of the corresponding jackets to take account of the technical requirements in terms of the static and dynamic stability of the cylinder block in the cylinder. space between two neighboring cylinders.
• the enlargement of the upper part of the cylinder liner can take different forms.
• this enlargement can have a conical shape just as it can have a convex shape more or less complex according to casting constraints or other aspects of manufacture to be taken into account.
• the dimensions of the widening or widening of the upper part of the outer wall of the jacket according to the invention are determined as a function of the radial distance between the outer walls of two cylinder liners intended to dress the cylindrical walls of two neighboring cylinders.
• the flaring of the upper part of the liner can be determined so that the upper edges of two lining the cylindrical walls of two neighboring cylinders define between them a negligible space, but existing when the engine is cold. This space decreases or disappears when the engine becomes hot.
• the flaring of the upper part of the liner can be determined so that the upper edges of two lining the cylindrical walls of the two adjacent cylinders are brought closer to one another so that there is no space between these upper edges when the engine is hot. A negligible space then reappears when the engine cools.
• the object of the invention is also achieved with a cylinder block of an internal combustion engine having at least two cylinders, each cylinder comprising a cylindrical wall dressed with a cylinder liner having the characteristics described above.
• This cylinder block can be arranged so that the upper surface of the cylinder block is substantially free of spaces between the adjacent cylinder liners or the upper surface of the cylinder block is free of space between two cylinder liners covering two neighboring cylinders, when the engine is hot.
• FIG. 1 represents, in an axial section, two cylinder liners according to a first embodiment of the invention, dressing two neighboring cylinders
• FIG. 2 shows, in perspective and extract view, the cylinder liners of FIG. 1 covering two neighboring cylinders
• FIG. 3 shows the two cylinder liners of FIG. 1 in more detail
• FIG. 1 is an axial section, two cylinder liners according to a second embodiment of the invention, dressing two neighboring cylinders, - Figure 5 shows, in a very schematic perspective view, a cylinder block four-cylinder in line, and Figure 6 shows, in a very diagrammatic perspective view, a cylinder block four cylinders staggered.
• A1 and B1 for the first embodiment of the jacket of the invention and A2 and B2 for the second embodiment of the sleeve of the invention.
• a cylinder liner 2 according to the first embodiment of the invention is intended for the cladding of the cylindrical wall 1 of an Al or Bl cylinder of a cylinder block C of an internal combustion engine.
• the outer wall 4 of the cylinder liner 2 comprises an upper portion 6 flaring towards the upper edge 5 of the liner 2.
• the outer wall 4 of the cylinder liner 2 comprises an upper portion 6 substantially conical.
• the outer wall 4 is provided with striations 8 intended to improve the intimate connection between the cylinder block C and the jacket 2.
• These striations 8 may be made over the entire axial length of the jacket, that is to say up to upper edge 5, or the axial length of the sleeve with the exception of that of the upper part 6, just as these striations may be limited to an annular portion of the sleeve.
• the cylinder liner 2 is not provided with striations, especially when it is a removable cylinder liner or, conversely, that these striations go up to the upper surface of the cylinder. shirt.
• the flaring of the upper part 6 of the outer wall 4 of the jacket 1 of the invention is determined as a function of a radial distance 7 (see Figure 5) between the outer walls 4 of the two cylinder liners 2 intended to dress the cylindrical walls 1 of the two neighboring cylinders A1, B1.
• the flare is referenced at 9.
• the flaring 9 of the upper part 6 of the outer wall 4 of the cylinder liner of the invention can be made in a concave form (FIG. 1) or in a strictly conical form ( Figures 2, 3).
• the taper shown in FIG. 3, in detail A can be easily expressed by means of an angle 11 opening between the right periphery of the outer wall 4 and the orientation of the upper conical portion 6 of the shirt 2.
• the liner 102 comprises an inner wall 3 for guiding a piston in translation and an outer wall 104 intended to bear on the cylindrical wall 1 of the cylinder.
• the inner and outer walls 104 of the cylinder liner 102 are substantially co-cylindrical and delimit between them an upper edge 5 of the liner for receiving at least a portion of a cylinder head gasket.
• the second embodiment differs from the first essentially by the shape of widening or widening of the upper part 106 or 6. Indeed, to show that I 1 flaring of the upper part of the outer wall of the cylinder liner according to the invention.
• the invention may be of any technically reasonable form, the flare according to FIG.
• This arrangement of the invention also makes it possible to provide a thermal bridge between the adjacent shirts and especially a substantially continuous bearing surface for the support of a cylinder head gasket interposed between all the upper edges 5 of the jackets. cylinder 2 and the cylinder head covering the cylinders.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Cylinder Crankcases Of Internal Combustion Engines (AREA)
• Pistons, Piston Rings, And Cylinders (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

Country Status (5)

Families Citing this family (10)

Family Cites Families (19)

• 2005
  • 2005-06-29 FR FR0506654A patent/FR2887926B1/fr not_active Expired - Fee Related
• 2006
  • 2006-06-28 WO PCT/FR2006/001504 patent/WO2007003761A1/fr not_active Ceased
  • 2006-06-28 US US11/993,845 patent/US8695558B2/en active Active
  • 2006-06-28 JP JP2008518917A patent/JP5041296B2/ja not_active Expired - Fee Related
  • 2006-06-28 EP EP06778697.0A patent/EP1896714B1/de not_active Not-in-force

Non-Patent Citations (1)

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