EP4490334A1 - Ébauche de piston, piston et procédé - Google Patents

Ébauche de piston, piston et procédé

Info

Publication number
EP4490334A1
EP4490334A1 EP23712481.3A EP23712481A EP4490334A1 EP 4490334 A1 EP4490334 A1 EP 4490334A1 EP 23712481 A EP23712481 A EP 23712481A EP 4490334 A1 EP4490334 A1 EP 4490334A1
Authority
EP
European Patent Office
Prior art keywords
piston
percent
combustion chamber
steel alloy
blank
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
EP23712481.3A
Other languages
German (de)
English (en)
Inventor
Holger Germann
Gerhard Luz
Edward Werninghaus
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
KS Kolbenschmidt GmbH
Original Assignee
KS Kolbenschmidt GmbH
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.)
Filing date
Publication date
Application filed by KS Kolbenschmidt GmbH filed Critical KS Kolbenschmidt GmbH
Publication of EP4490334A1 publication Critical patent/EP4490334A1/fr
Pending legal-status Critical Current

Links

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 
    • F02F3/16—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
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
    • 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

Definitions

  • the present invention relates to a piston blank for a piston, a piston with such a piston blank and a method for producing such a piston using such a piston blank.
  • Pistons for internal combustion engines can be made from steel alloys, such as the tempered steel 42CrMo4 or the microalloyed steel 38MnVS6.
  • Such pistons can either be made in one piece or can be composed of a lower piston part and an upper piston part, which can be connected to one another using a joining process. Cooling of such a piston can take place via a jet of cooling oil, which is injected into a circumferential annular cooling channel of the piston using an injection nozzle. For this purpose, a certain minimum volume flow of the cooling oil is necessary in order to keep highly stressed areas of the piston below a critical temperature for scaling of the piston via appropriate heat dissipation.
  • the aforementioned materials Due to their chemical composition, the aforementioned materials have a predetermined thermal conductivity that is similar for both materials. Depending on the design of the piston cooling, this results in a certain combustion chamber surface temperature. This combustion chamber surface temperature cannot be increased any further since the aforementioned materials have limited resistance to scaling. If the combustion chamber surface temperature increases further, this can result in cracking caused by scaling and thus the piston failing.
  • WO 2014/198896 A1 describes a piston, in particular a steel piston, for an internal combustion engine with a piston crown that is part of a combustion chamber, at least the piston crown having an oxidation protection layer.
  • an object of the present invention is to provide an improved piston blank for a piston.
  • the piston blank is made at least in sections from a steel alloy that has a chromium content of 0.5 to 2 percent by weight and a silicon content of 2.5 to 3.5 percent by weight.
  • the steel alloy has the aforementioned chromium content and the silicon content, the steel alloy is particularly resistant to scaling.
  • a combustion chamber surface temperature of a piston made from the piston blank can be increased without the piston becoming scaled. This leads to an increase in the thermodynamic efficiency of engine combustion. This means that stricter requirements with regard to fuel consumption and emissions, especially CO2 emissions, can be met.
  • a temperature of a surface of a piston crown of the piston can be understood in particular.
  • the “combustion chamber surface temperature” can generally be understood to mean a temperature of a surface of a combustion chamber assigned to the piston. The surface of the piston crown can be part of the combustion chamber.
  • the piston blank differs from the piston in that the piston, in comparison to the piston blank, is machined, for example, with the aid of a removal and/or forming manufacturing process.
  • the piston blank can also differ from the piston in that a lower piston part of the piston blank and an upper piston part of the piston blank are not yet firmly connected to one another.
  • the piston blank or the piston can in particular be assigned a symmetry or central axis, with respect to which the piston blank or the piston can be constructed essentially rotationally symmetrical.
  • This aforementioned central axis can in particular be formed by a central axis of a cylinder which encloses surfaces of a piston skirt of the piston and thereby has a minimum diameter, the central axis of the cylinder being arranged perpendicular to a bolt bore of the piston.
  • the piston blank or the piston is also assigned a coordinate system with a width direction or x-direction, a vertical direction or y-direction and a depth direction or z-direction.
  • the y direction can also be called the axial direction.
  • the terms “y-direction” and “axial direction” can therefore be interchanged in any way.
  • the directions are oriented perpendicular to each other.
  • the central axis coincides with the y-direction or is oriented parallel to the y-direction.
  • a radial direction is also assigned to the piston blank or the piston.
  • the radial direction is oriented perpendicular to the central axis and points away from it.
  • the steel alloy is preferably a so-called low-alloy steel alloy.
  • the steel alloy can, for example, be formed into the piston blank as a semi-finished product using a forging process.
  • the piston blank or the previously mentioned lower piston part and the aforementioned piston upper part can therefore be forged components.
  • the piston blank or the lower piston part and the upper piston part can also be cast components or cast components reworked by a forging process.
  • the steel alloy is provided at least in the area of a combustion chamber bowl of the piston blank or the piston. In the event that the piston blank has a lower piston part as mentioned above and an upper piston part, for example only the upper piston part can be made of the steel alloy.
  • the steel alloy from which the piston blank is made has a lower thermal conductivity. This results in less heat being dissipated from a combustion chamber of an internal combustion engine having the piston during operation of the piston. This increases the combustion chamber surface temperature, which leads to an increase in the thermodynamic efficiency of engine combustion.
  • the alloy components chromium and silicon prevent scaling at the increased combustion chamber surface temperature.
  • scaling or “oxidation wear” can be understood to mean the high-temperature corrosion of metals caused by direct chemical reactions with hot gases containing oxygen.
  • the steel alloy can contain the elements carbon, manganese, phosphorus, sulfur, molybdenum, titanium, lead, antimony, aluminum, nitrogen, copper, tin, nickel and boron. Oxygen and hydrogen can also be contained in small amounts in the steel alloy.
  • the chromium content is 0.9 to 1.2 percent by weight and/or the silicon content is 2.85 to 3 percent by weight.
  • the steel alloy has a carbon content of 0.35 to 0.5, in particular 0.4 to 0.44, percent by weight.
  • This low carbon content makes the steel alloy easy to form, meaning the piston blank can be manufactured and/or machined using a forging process.
  • the steel alloy has a manganese content of 0.5 to 0.9, in particular 0.6 to 0.8, percent by weight.
  • a property of the manganese content in the steel alloy is that the hardenability of the steel alloy is increased.
  • the steel alloy has a titanium content of 0.005 to 0.015 percent by weight.
  • the titanium content gives the steel alloy high toughness, strength and ductility.
  • the steel alloy has a molybdenum content of 0.1 to 0.3, in particular 0.15 to 0.2, percent by weight.
  • the molybdenum content leads to an increase in the tempering resistance and the high-temperature strength of the steel alloy.
  • the steel alloy has a silicon content of 2.5 to 3.5, in particular 2.85 to 3, percent by weight.
  • the silicon content leads to an increase in tensile strength and yield strength as a result of solid solution solidification and, as a diffusion barrier for oxygen, increases the resistance to scaling of the steel alloy.
  • the steel alloy has an increased resistance to scaling at 550 to 650 ° C, in particular at 580 to 600 ° C.
  • Scaling resistance or “scaling resistance” is primarily understood to mean resistance to scaling.
  • the scaling resistance can be determined by measuring a weight of the piston blank or the piston or additionally by measuring a scale layer thickness, aging or annealing the piston blank or the piston at a certain temperature, then measuring the weight of the piston blank or the piston and finally determining a Degree of oxidation can be determined based on a change in weight of the piston blank or the piston.
  • the increased resistance to scaling allows the piston to be used at higher temperatures, which means the combustion chamber surface temperature can be increased with the advantages mentioned above.
  • the piston blank has a lower piston part and an upper piston part, the upper piston part being made from the steel alloy, the lower piston part being made from the steel alloy or from a further material that differs from the steel alloy, and wherein the further material is in particular a higher one Thermal conductivity than the steel alloy.
  • At least the upper piston part is preferably made of the steel alloy.
  • “Thermal conductivity” or “thermal conductivity coefficient” is a material property that determines heat flow through a material due to heat conduction. The lower the thermal conductivity, the better the thermal insulation.
  • the other material can be, for example, the previously mentioned tempered steel 42CrMo4 or the microalloyed beam 38MnVS6.
  • the lower piston part and the upper piston part are connected to one another using a joining process.
  • the lower piston part and the upper piston part are materially connected to one another to form an intermediate component of the piston from which the finished piston is produced. In the case of cohesive connections, the connection partners are formed by atomic or molecular lar forces held together.
  • Cohesive connections are non-detachable connections that can only be separated again by destroying the connecting means and/or the connecting partners.
  • the lower piston part and the upper piston part are welded together, in particular friction welded together.
  • the intermediate component can be further processed using an abrasive manufacturing process, in particular using a cutting process, in order to form the piston from the intermediate component.
  • the upper piston part and the lower piston part can be connected to one another in a form-fitting manner.
  • a positive connection is created by two connection partners interlocking or reaching behind each other.
  • the lower piston part and the upper piston part can be screwed together.
  • the piston blank is a one-piece component that is made entirely of the steel alloy.
  • the piston blank does not have a separate lower piston part and upper piston part.
  • “One-piece” or “one-piece” means in the present case that the piston blank is not composed of different sub-components, but rather forms a single component.
  • the piston blank can in particular be designed in one piece of material.
  • “One-piece material” means that the piston blank is made entirely of the same material, namely the steel alloy.
  • the piston differs from the piston blank in that the lower piston part and the upper piston part of the piston are firmly connected to one another.
  • the piston may further differ from the piston blank in that the piston blank is used to form the piston is processed.
  • the processing can be carried out, for example, using a forging process and/or a removal process, such as turning, milling, eroding or the like.
  • the piston is part of the previously mentioned internal combustion engine.
  • the internal combustion engine can include multiple pistons.
  • the piston comprises a combustion chamber bowl and a cooling channel which runs at least in sections around the combustion chamber bowl, an average first wall thickness of a first wall provided between the combustion chamber bowl and the cooling channel being greater than 5 percent, preferably greater than 6 percent, preferably greater than 7 percent, a piston diameter of the piston.
  • the combustion chamber bowl can already be formed on the piston blank, in particular on the upper piston part.
  • the combustion chamber bowl can be formed and/or reworked using a removal process or a forging process.
  • the cooling channel runs in a ring around the central axis of the piston.
  • a cooling oil in particular engine oil, can be passed through the cooling channel to dissipate heat from the piston.
  • the cooling oil can, for example, be injected into the cooling channel through bores provided on the piston using an injection nozzle. Because the first wall thickness is greater than 5 percent of the piston diameter, the dissipation of heat by the cooling oil in the area of the combustion chamber bowl can be further reduced. This leads to an additional increase in the combustion chamber surface temperature and thus in the thermodynamic efficiency.
  • a respective wall thickness between the cooling channel and the combustion chamber bowl and between an inner shape of the piston and the combustion chamber bowl is usually designed to be 3.5 percent of the piston diameter.
  • heat dissipation can be reduced.
  • An increase in the combustion chamber surface temperature and the thermodynamic efficiency can also be achieved by adapting a geometry, in particular a cross-sectional geometry, of the cooling channel.
  • the cooling channel can be equipped with a smaller cross-sectional geometry compared to cooling channels known internally, which also reduces the dissipation of heat from the combustion chamber bowl. This measure is also advantageous in terms of the dimensions and height of the piston.
  • the cooling channel can alternatively be designed as an open cooling channel, which is sprayed with cooling oil via a freely accessible inner surface using the injection nozzle.
  • the piston can also be designed entirely without a cooling channel.
  • the amount of cooling oil used to cool the piston can be reduced. This also increases the combustion chamber surface temperature and thus the thermodynamic efficiency. There is also an additional efficiency advantage as the power loss of a required oil pump is reduced, which leads to an indirect contribution to fuel savings.
  • the “piston diameter” is to be understood as meaning a diameter of a smallest cylinder, which includes a so-called piston skirt of the piston.
  • the first wall thickness of the first wall is defined in particular as a smallest distance between the combustion chamber trough, in particular a rounding of the combustion chamber trough, and the cooling channel, in particular a wall of the cooling channel.
  • the average first wall thickness is at least 5 millimeters.
  • the “average” first wall thickness is to be understood in particular as meaning that the first wall thickness, viewed along its extension direction or main extension direction, is on average at least 5 millimeters or is greater than 5 percent of the piston diameter.
  • a direction can be be understood as the direction along which the first wall has its greatest geometric extent.
  • the “extension direction” or “main extension direction” can be understood to mean a course of the first wall along a surface of the combustion chamber bowl. This surface can be referred to as the combustion chamber bowl surface. This means that the first wall thickness can be less than the previously mentioned 5 percent of the piston diameter or 5 mm in some areas or locally.
  • the first wall thickness is on average at least 5 millimeters or the first wall thickness is greater than 5 percent of the piston diameter.
  • extension direction and “main extension direction” can be used interchangeably in this case.
  • an average second wall thickness of a second wall provided between the combustion chamber bowl and an inner shape of the piston is greater than 5 percent, preferably greater than 6 percent, particularly preferably greater than 7 percent, of the piston diameter.
  • the combustion chamber trough preferably has a combustion chamber trough bottom facing the combustion chamber and the internal shape facing away from the combustion chamber.
  • the combustion chamber bowl base and the inner shape can each be conical or conical. Facing the combustion chamber, the second wall forms the combustion chamber trough floor. Facing away from the combustion chamber, the second wall forms the interior shape.
  • the first wall and the second wall merge into one another.
  • the second wall thickness of the second wall is defined in particular as a smallest distance between the combustion chamber trough, in particular the combustion chamber trough bottom of the combustion chamber trough, and the inner shape.
  • the first wall merges into the second wall or vice versa, in particular at the previously mentioned rounding of the combustion chamber bowl. This means in particular that the first wall is connected to the second wall.
  • the average second is
  • Wall thickness at least 5 millimeters.
  • the second wall can be less than the second wall thickness of at least 5 millimeters or 5 percent of the piston diameter in some areas or locally. On average, however, the second wall thickness is always greater than 5 millimeters or at least 5 percent of the piston diameter.
  • the second wall thickness viewed along an extension direction or main extension direction of the second wall, is on average at least 5 millimeters or is at least 5 percent of the piston diameter.
  • the design measures such as increasing the wall thickness of the walls, adapting the geometry of the cooling channel and/or reducing the amount of cooling oil, have an analogous effect, which leads to a higher combustion chamber surface temperature by reducing the dissipation of heat.
  • the thermodynamic efficiency of combustion can be increased and thus fuel consumption can be reduced.
  • CO2 emissions can be reduced.
  • the prerequisite for this is sufficient resistance to scaling.
  • the alloy components of the steel alloy lead to increased resistance to scaling. This means that a limit temperature above which technically relevant scaling occurs can be shifted to a higher temperature. Due to the high resistance to scaling of the steel alloy, additional measures on the combustion side can also be taken to increase the combustion chamber surface temperature and increase the thermodynamic efficiency.
  • thermodynamic efficiency of the internal combustion engine can be significantly increased using a permanent and at the same time low thermally conductive steel alloy, at least for the upper piston part and/or in the area of the combustion chamber bowl. This allows consumption advantages and the reduction of CO2 emissions to be achieved. This means that the constantly increasing requirements of legislation and the market can be met. Increasingly stricter limits with regard to exhaust gases, fuel consumption and emissions, especially CO2 emissions, can be adhered to.
  • the piston blank is made from a steel alloy which has a chromium content of 0.5 to 2 percent by weight and a silicon content of 2.5 to 3.5 percent by weight.
  • the piston blank can be a cast component.
  • the piston blank can also be a forged component.
  • the piston blank can also be a cast component, which is reworked using a forging process.
  • the lower piston part and the upper piston part can be manufactured separately from one another.
  • the lower piston part and the upper piston part are firmly connected to one another, in particular welded to one another, to form the aforementioned intermediate component or the piston.
  • the intermediate component can be processed using a removal and/or forming manufacturing process.
  • piston blank, the piston and/or the method also include combinations of features or embodiments described above or below with regard to the exemplary embodiments that are not explicitly mentioned.
  • the person skilled in the art will also add individual aspects as improvements or additions to the respective basic shape of the piston blank, the piston and/or the process.
  • piston blank, the piston and/or the method are the subject of the subclaims and the exemplary embodiments of the piston blank, the piston and/or the method described below. Furthermore, the piston blank, the piston and/or the method are explained in more detail using preferred embodiments with reference to the accompanying figures.
  • Fig. 1 shows a schematic side view of an embodiment of a vehicle!
  • FIG. 2 shows a schematic sectional view of an embodiment of a piston for an internal combustion engine
  • Fig. 3 shows the detailed view III according to Fig. 2;
  • Fig. 4 shows a schematic perspective partial sectional view of the piston according to Fig. 2
  • Fig. 5 shows a schematic sectional exploded view of an embodiment of a piston blank for the piston according to Fig. 2;
  • Fig. 6 shows a schematic sectional view of an intermediate component for the piston according to Fig. 2;
  • FIG. 7 shows a schematic block diagram of an embodiment of a method for producing the piston blank according to FIG. 2.
  • the vehicle 1 shows a schematic side view of an embodiment of a vehicle 1.
  • the vehicle 1 is a motor vehicle, in particular a passenger car.
  • the vehicle 1 can also be a commercial vehicle, for example a truck, a harvester or a construction machine.
  • the vehicle 1 can also be a military vehicle.
  • the vehicle can also be an aircraft, a watercraft or a rail vehicle.
  • it is assumed below that the vehicle 1 is a motor vehicle, in particular a passenger car.
  • the vehicle 1 includes a body 2, which encloses a passenger compartment or vehicle interior 3 of the vehicle 1. A driver and passengers can stay in the vehicle interior 3.
  • the body 2 delimits an environment 4 of the vehicle 1 from the vehicle interior 3.
  • the vehicle interior 3 is accessible from the surroundings 4 using doors.
  • the vehicle 1 includes a chassis with several wheels 5, 6.
  • Wheels 5, 6 are basically arbitrary.
  • the vehicle 1 preferably has four wheels
  • the vehicle 1 can, for example, have six wheels 5, 6 point.
  • the wheels 5, 6 are part of a chassis of the vehicle 1. Only two wheels 5, 6 can be driven. However, all wheels 5, 6 can also be driven. In this case, the vehicle 1 is a four-wheel drive vehicle.
  • the vehicle 1 includes an internal combustion engine or an internal combustion engine 7.
  • the internal combustion engine 7 can be a diesel engine or a gasoline engine.
  • the vehicle 1 can be driven purely by the internal combustion engine 7.
  • the vehicle 1 can also be a hybrid vehicle.
  • the vehicle 1 has at least one electric motor in addition to the internal combustion engine 7.
  • the internal combustion engine 7 includes an engine block and a plurality of pistons accommodated in piston bores of the engine block.
  • the internal combustion engine 7 can have three, four, five, six or more than six pistons.
  • FIG. 2 shows a schematic sectional view of an embodiment of a piston 8 for the internal combustion engine 7.
  • FIG. 3 shows the detailed view III according to FIG. 2.
  • FIG .2 to 4 referenced simultaneously.
  • the piston 8 can be part of a vehicle 1 as explained above, in particular the internal combustion engine 7. However, the piston 8 is particularly preferably part of a commercial vehicle. In this case, the vehicle 1 is a commercial vehicle.
  • the internal combustion engine 7 and thus the piston 8 can be used in any vehicle 1, ships, machines or the like. Furthermore, the internal combustion engine 7 or the piston 8 can also be used for stationary applications, such as for generators, power, heat or the like.
  • the piston 8 can include a symmetry or central axis 9, to which the piston 8 can be constructed essentially rotationally symmetrical.
  • the piston 8 is assigned a coordinate system with a width direction or x-direction x, a vertical direction or y-direction y and a depth direction or z-direction z.
  • the y direction y can also be called the axial direction.
  • the terms “y-direction” and “axial direction” can therefore be interchanged in any way.
  • the directions x, y, z are oriented perpendicular to each other.
  • the central axis 9 corresponds in particular to the y-direction y or is oriented parallel to it.
  • the piston 8 is also assigned a radial direction R.
  • the radial direction R is oriented perpendicular to the central axis 9 and points away from it.
  • the piston 8 has a piston foot or piston skirt 10 and a piston head 11. Viewed along the central axis 9, the piston skirt 10 is arranged below the piston head 11.
  • the piston skirt 10 has a piston hub with a bolt bore 12, in which a bolt, not shown, for coupling the piston 8 to a connecting rod, not shown, of the internal combustion engine 7 can be received.
  • a symmetry or central axis 13 of the bolt bore 12 intersects the central axis 9 or is arranged offset from it.
  • the central axis 13 is oriented perpendicular to the central axis 9.
  • the central axis 13 corresponds to the z direction z or is oriented parallel to it.
  • a shaft section 14, 15 is provided on both sides of the piston hub.
  • a first shaft section 14 and a second shaft section 15 are provided.
  • the shaft sections 14, 15 can be cylindrical in sections. In other words, the shaft sections 14, 15 can form part of a cylinder which is constructed rotationally symmetrical to the central axis 9.
  • the shaft sections 14, 15 together form a so-called piston skirt of the piston 8.
  • the shaft sections 14, 15 can be constructed in sections rotationally symmetrical to the central axis 9. Included However, the shaft sections 14, 15 in particular do not form a complete cylinder.
  • One of the shaft sections 14, 15 forms a pressure side of the piston 8, the other of the shaft sections 14, 15 forming a counter-pressure side of the piston 8.
  • the shaft sections 14, 15 are connected to one another using wall sections 16, 17.
  • a first wall section 16 and a second wall section 17 are provided.
  • the radial direction R points away from the central axis 9 towards the shaft sections 14, 15 and outwards.
  • the bolt bore 12 breaks through the wall sections 16, 17.
  • the shaft sections 14, 15 and the wall sections 16, 17 enclose an interior 18 of the piston skirt 10.
  • the interior 18 is open downwards in the orientation of FIGS. 2 to 4.
  • the previously mentioned bolt for coupling the piston 8 to the connecting rod runs along the central axis 13 through the interior 18.
  • the piston 8 has a cooling channel 19 which runs completely around the central axis 9 and is preferably constructed rotationally symmetrical to it.
  • the cooling channel 19 is in particular toroidal.
  • the cooling channel 19 has a wall 20 which defines a geometry or a cross-sectional geometry of the cooling channel 19.
  • a cooling oil in particular engine oil, can be passed through the cooling channel 19 in order to dissipate heat Q introduced into the piston 8 during operation.
  • the cooling oil can be injected into the cooling channel 19 using an injection nozzle arranged below the piston 8 in the orientation of FIGS. 2 to 4.
  • the cooling channel 19 is in fluid communication with the interior 18.
  • the number of holes 21, 22 is basically arbitrary.
  • several bores 21, 22 are provided, which can be arranged evenly distributed around the central axis 9.
  • the bores 21, 22 can also be arranged unevenly distributed around the central axis 9 be.
  • cooling oil can be injected into the interior 18 from below using the aforementioned injection nozzle. At least some of the cooling oil passes through the bores 21, 22 into the cooling channel 19 and out again. Heat Q is then removed from the piston 8 with the cooling oil.
  • the piston head 11 has a piston crown 23 which faces a cylinder head of the internal combustion engine 7. A large part of the heat Q is also introduced into the piston crown 23.
  • the piston crown 23 faces in particular a combustion chamber 24 of the internal combustion engine 7.
  • the piston crown 23 comprises an annular piston crown section 25, which spans a plane oriented perpendicular to the central axis 9.
  • the piston crown 23 has a combustion chamber bowl 26, which is set back with respect to the piston crown section 25. Viewed along the central axis 9 or along the y direction y, the combustion chamber bowl 26 is thus arranged offset or recessed with respect to the piston crown section 25.
  • the combustion chamber bowl 26 can have any geometry.
  • the combustion chamber bowl 26 has a shoulder 27 which runs around the central axis 9 and is set back relative to the piston crown section 25 when viewed along the y-direction y.
  • a combustion chamber trough edge 28 of the combustion chamber trough 26 protrudes radially into the combustion chamber trough 26 when viewed counter to the radial direction R.
  • the edge of the combustion chamber trough 28 is adjoined by a rounding 29 that runs around the central axis 9.
  • the rounding 29 merges into a, in particular conical or conical, combustion chamber bowl base 30, which extends upwards when viewed along the y-direction y.
  • the combustion chamber bowl base 30 ends, viewed along the y direction y, but below the paragraph 27.
  • a first wall 31 (FIG. 3) is provided between the combustion chamber trough 26 and the cooling channel 19.
  • the first wall 31 fluidly separates the cooling channel 19 from the combustion chamber bowl 26.
  • the first wall 31 runs completely around the central axis 9.
  • the first wall 31 has a first wall thickness w31.
  • the first wall thickness w31 is at least 5 mm.
  • an average of the first wall thickness w31 over the entire first wall 31 is at least 5 mm. This means that the first wall 31 can also have a smaller first wall thickness w31 than 5 mm in some areas or locally.
  • the first wall thickness w31 is always at least 5 mm on average.
  • the “main extension direction” is to be understood as meaning a direction, in this case the y direction y, along which the first wall 31 has its greatest geometric extent.
  • a second wall 32 separates the combustion chamber bowl 26 from the interior 18.
  • the second wall 32 forms the combustion chamber trough floor 30 on the front side.
  • the inner shape 33 can be conical or conical.
  • the second wall 32 has a second wall thickness w32.
  • the second wall thickness w32 is also at least 5 mm.
  • an average of the second wall thickness w32 over the entire second wall 32 is at least 5 mm.
  • the second wall 32 can also have a smaller second wall thickness w32 than 5 mm in some areas or locally.
  • the second wall thickness w32 is always at least 5 mm on average.
  • the piston 8 has a piston diameter d8.
  • the piston diameter d8 is defined as a diameter of the smallest possible cylinder, which includes the piston skirt, i.e. the shaft sections 14, 15. This cylinder is countersunk oriented right to the central axis 13.
  • the first wall thickness w31 is at least on average greater than 5% of the piston diameter d8.
  • the first wall thickness w31 is at least on average greater than 6% of the piston diameter d8.
  • the first wall thickness w31 is at least on average greater than 7% of the piston diameter d8.
  • the first wall thickness w31 is at least 5 mm on average.
  • the second wall thickness w32 is also at least on average greater than 5% of the piston diameter d8.
  • the second wall thickness w32 is at least on average greater than 6% of the piston diameter d8. Particularly preferably, the second wall thickness w32 is at least on average greater than 7% of the piston diameter d8. However, the second wall thickness w32 is at least 5 mm on average.
  • any number of cutting planes E can be placed through the central axis 9.
  • the central axis 9 lies in each of these cutting planes E.
  • the first wall thickness w31 and/or the second wall thickness w32 is on average at least 5%, preferably 6%, more preferably 7%, of the piston diameter d8 and/or is at least 5 mm.
  • the average wall thicknesses w31, w32 can each be calculated separately.
  • the respective average wall thickness w31, w32 can be calculated along a cutting contour of the first wall 31 and/or the second wall 32 located in the respective cutting plane E with a constant step size or a constant increment of not more than 1 mm.
  • the wall thicknesses w31, w32 are calculated along a line formed by the aforementioned cutting contour, which is formed by a section of the cutting plane E with surfaces of the combustion chamber bowl 26 and the piston crown section 25.
  • the first wall thickness w31 of the first wall 31 is defined in particular as a smallest distance between the combustion chamber trough 26, in particular the rounding 29, and the cooling channel 19, in particular the wall 20 of the cooling channel 19.
  • the second wall thickness w32 of the second wall 32 is defined in particular as a smallest distance between the combustion chamber trough 26, in particular the combustion chamber trough bottom 30, and the inner shape 33.
  • the first wall 31 merges into the second wall 32 at the rounding 29 or vice versa. This means in particular that the first wall 31 is connected to the second wall 32.
  • a ring section or an annular field 34 is provided on the piston head 11.
  • the ring field 34 in particular forms a substantially cylindrical outer surface of the piston head 11, which can be constructed rotationally symmetrical to the central axis 9.
  • the ring field 34 has a plurality of ring grooves 35 arranged one above the other when viewed along the y-direction y, only one of which is provided with a reference number in FIG.
  • the annular grooves 35 are suitable for receiving piston rings. For example, two or three such annular grooves 35 are provided.
  • a top land 36 adjoining the piston crown 23 is part of the ring field 34. However, the top land 36 does not have an annular groove 35 as mentioned above for receiving a piston ring.
  • the piston 8 is in two parts and includes a lower piston part 37 and an upper piston part 38.
  • the lower piston part 37 and the upper piston part 38 are two separate components which are materially connected to one another to form the piston 8.
  • cohesive connections the connection partners are held together by atomic or molecular forces.
  • Cohesive connections are non-detachable connections that can only be separated again by destroying the connecting means and/or the connecting partners.
  • Cohesive connections can be made, for example, by gluing, soldering or welding.
  • the lower piston part 37 is welded to the upper piston part 38, in particular friction welded.
  • pistons in particular in known steel pistons, either a tempered steel 42CrMo4 or a microalloyed steel 38MnVS6 can be used as materials.
  • These pistons can either be made in one piece or have a lower piston part and an upper piston part, which are connected to one another by a joining operation. As a rule, the entire piston is made of the same material, even in two-part concepts.
  • the cooling of such a piston takes place via a jet of cooling oil, which is injected into a circumferential, annular cooling channel using an injection nozzle.
  • a certain minimum volume flow of cooling oil is necessary in order to keep the highly stressed areas, in particular the edge of the combustion chamber bowl, below the critical temperature for scaling of the piston via appropriate heat dissipation.
  • Both of the above-mentioned materials 42CrMo4 and 38MnVS6 have a thermal conductivity that is determined by their chemical composition and is similar for both materials. This results in a certain combustion chamber surface temperature with standard piston cooling. This cannot be increased further because both materials have limited resistance to scaling, and an increase in the combustion chamber surface temperature could lead to a crack caused by scaling and thus to failure of the piston.
  • a low-alloy steel alloy with the following chemical composition is particularly suitable for the piston 8:
  • Silicon Si 2.5 to 3.5 percent by weight, in particular 2.85 to 3 percent by weight.
  • Chromium CE 0.5 to 2 percent by weight, in particular 0.9 to 1.2 percent by weight.
  • Manganese Mn 0.5 to 0.9 percent by weight, in particular 0.6 to 0.8 percent by weight.
  • Titanium Ti 0.005 to 0.015 percent by weight.
  • Molybdenum Mo 0.1 to 0.3 percent by weight, in particular 0.15 to 0.2 percent by weight.
  • the steel alloy mainly contains the element iron Fe.
  • the steel alloy has increased resistance to scaling at 550 to 650 °C, especially at 580 to 600 °C.
  • the entire piston 8 is made of this steel alloy.
  • the piston 8 is in two parts and has the upper piston part 38 that is separate from the lower piston part 37, only the upper piston part 38, which has the combustion chamber bowl 26, can be made of the steel alloy.
  • the tempered steel 42CrMo4 or the microalloyed steel 38MnVS6 are then preferably used for the lower piston part 37.
  • the increase in the combustion chamber surface temperature can be further increased by constructive measures by reducing the cooling effect in the area of the combustion chamber bowl 26. This is possible because the steel alloy can withstand a higher surface temperature in the combustion chamber bowl 26 due to its higher resistance to scaling without causing the piston 8 to fail.
  • This increase in the combustion chamber surface temperature can be achieved by the measures already explained above and which can be combined with one another.
  • the wall thicknesses w31, w32 in the area of the combustion chamber trough 26 the dissipation of heat Q through the cooling oil is further reduced and thus leads to an additional increase. tion of the combustion chamber surface temperature and thus the thermodynamic
  • the cooling channel 19 can be equipped with a smaller cross section compared to known pistons, whereby the dissipation of heat Q is reduced. In addition, this measure is advantageous with regard to the dimensions and the overall height of the piston 8.
  • the cooling channel 19 can be designed as an open cooling channel, which is sprayed with the cooling oil via a freely accessible inner surface. Furthermore, it is also possible to completely dispense with the cooling channel 19.
  • the use of the steel alloy with low thermal conductivity leads to a reduction in the dissipation of heat Q from the combustion chamber trough 26 to the cooling channel 19 and thus to an increase in the surface temperature of the combustion chamber trough 26 and the combustion chamber 24.
  • the steel alloy has a higher temperature than the materials 42CrMo4 or 38MnVS6 Thermal conductivity is around 20 W/m*K lower. Simulations have shown that a combustion chamber bowl edge temperature at the combustion chamber bowl edge 28 increases by 2 K for every 1 W/m*K reduced thermal conductivity.
  • the steel alloy is also highly resistant to scaling, which means that a limit temperature at which technically relevant scaling occurs can be shifted by at least 70 K towards a higher temperature. Due to the high resistance to scaling of the steel alloy, additional measures on the combustion side can also be taken to increase the combustion chamber surface temperature and to increase the thermodynamic efficiency.
  • thermodynamic efficiency of the internal combustion engine 7 can be increased. This allows consumption advantages and advantages in terms of CO2 emissions to be realized.
  • FIG. 5 shows a schematic sectional exploded view of an embodiment of a piston blank 39 for the piston 8.
  • the piston 8 can be manufactured with the help of the piston blank 39.
  • the piston blank 39 includes a lower piston part 37 as mentioned above and an upper piston part 38 as mentioned above.
  • the piston blank 39 differs from the piston 8 in that the lower piston part 37 is not yet connected to the piston part. Upper part 38 is connected.
  • the piston blank 39 can also differ from the piston 8 in that the piston 8 is machined after welding the lower piston part 37 to the upper piston part 38. Eroding, milling, turning or the like can be used as abrasive processes.
  • the piston blank 39 can also be formed to form the piston 8 using a forming manufacturing process, for example a forging process.
  • the central axis 9 can be assigned to the piston blank 39.
  • the previously mentioned coordinate system with the directions x, y, z can also be assigned to the piston blank 39.
  • the radial direction R can also be assigned to the piston blank 39.
  • the cooling channel 19 is partially formed on the lower piston part 37 and partially on the upper piston part 38.
  • a first cooling channel section 19A is provided on the lower piston part 37.
  • a second cooling channel section 19B can be provided on the piston upper part 38.
  • the cooling channel sections 19A, 19B together form the cooling channel 19.
  • the piston upper part 38 has the combustion chamber trough 26, which can be processed to produce the piston 8 from the piston blank 39 using a machining or forming manufacturing process, in order to produce the piston 8 in FIGS. 2 to 4 to produce the final geometry of the combustion chamber bowl 26 shown.
  • the lower piston part 37 and the upper piston part 38 are two separate components which can be materially connected to one another, in particular welded to one another.
  • the lower piston part 37 has a first joining surface 40 which runs annularly around the central axis 9 and a second joining surface 41 which runs around the central axis 9 in a ring. Viewed along the radial direction R, the second joining surface 41 is placed within the first joining surface 40.
  • the piston top part 38 has a first joining surface 42 which runs annularly around the central axis 9 and a second joining surface 43 which runs around the central axis 9 in a ring. Viewed along the radial direction R, the second joining surface 43 is placed within the first joining surface 42.
  • the lower piston part 37 can also have a circumferential shoulder 44, which extends radially out of the lower piston part 37 when viewed along the radial direction R. Paragraph 44 is optional.
  • the lower piston part 37 and the upper piston part 38 are each one-piece, in particular one-piece material, components. “In one piece” or “one-piece” means in the present case that the lower piston part 37 and the upper piston part 38 are not each composed of different sub-components, but rather each form a single component.
  • At least the upper piston part 38 is made, at least in sections, from the previously mentioned highly scaling-resistant steel alloy.
  • the upper piston part 38 is made of the steel alloy.
  • the lower piston part 37 can be made, for example, from the materials 42CrMo4 or 38MnVS6. Alternatively, the lower piston part 37 can also be made of the same highly scaling-resistant steel alloy from which the upper piston part 38 is made.
  • the piston blank 39 can also be a one-piece component. In this case, the lower piston part 37 and the upper piston part 38 are not two separate components that are subsequently connected to one another. The piston blank 39 is then made entirely of the highly scaling-resistant steel alloy.
  • “One-piece material” means that the lower piston part 37 and the upper piston part 38 are each made entirely of the same material.
  • the piston 8 itself or the piston blank 39, however, is made up of several parts.
  • the lower piston part 37 is preferably a cast component.
  • the piston upper part 38 can also be a cast component.
  • the lower piston part 37 can also be a Be a forged component.
  • the piston upper part 38 can also be a forged component. In the event that the lower piston part 37 and/or the upper piston part 38 is each a cast component, these can be reworked using a forging process. However, the lower piston part 37 and/or the upper piston part 38 can also be manufactured or machined using an abrasive manufacturing process.
  • FIG. 6 shows a schematic sectional view of an intermediate component 45 for the piston 8.
  • the lower piston part 37 and the upper piston part 38 are connected to one another at their joining surfaces 40 to 43 to form joining planes 46, 47.
  • the joining planes 46, 47 can be weld seams, in particular friction weld seams.
  • the first joining surfaces 40, 42 and the second joining surfaces 41, 43 are each firmly connected to one another.
  • the intermediate component 45 differs from the piston blank 39 in that the lower piston part 37 is firmly connected to the upper piston part 38, in particular welded. Friction welding, for example, is a suitable welding process.
  • the piston 8 differs from the intermediate component 45 in that, in contrast to the intermediate component 45, the piston 8 is reworked using a removal and/or forming manufacturing process.
  • the combustion chamber bowl 26 is machined, the annular field 34 is formed onto the intermediate component 45, the shoulder 44 is removed and protruding beads of the joining plane 46 are removed.
  • a cylindrical outer surface 48 of the intermediate component 45 can be machined to produce the ring field 34.
  • Figure 7 shows a schematic block diagram of an embodiment
  • the piston blank 39 is made from the steel alloy, which has a chromium content of 0.5 to 2 percent by weight and a silicon content of 2.5 to 3.5 percent by weight.
  • Step S1 may include casting, forming and/or machining the steel alloy.
  • the lower piston part 37 and the upper piston part 38 can be manufactured as separate components. In this case, at least the upper piston part 38 is made of the steel alloy.
  • the piston blank 39 can also be manufactured as a one-piece component in step S1. In this case, the lower piston part 37 and the upper piston part 38 are not two separate components.
  • the method can include a step S2, in which the lower piston part 37 and the upper piston part 38 are joined or assembled to form the intermediate component 45.
  • the lower piston part 37 and the upper piston part 38 are connected to one another in a material-fluid manner at the joining surfaces 40 to 43, in particular welded.
  • the lower piston part 37 and the upper piston part 38 are preferably friction-welded together at the joining surfaces 40 to 43.

Landscapes

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

Abstract

Est divulguée une ébauche de piston (39) pour un piston (8), ladite ébauche de piston (39) étant constituée au moins en partie d'un alliage d'acier contenant de 0,5 à 2 pour cent en poids de chrome et de 2,5 à 3,5 pour cent en poids de silicium.
EP23712481.3A 2022-04-13 2023-03-15 Ébauche de piston, piston et procédé Pending EP4490334A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102022108997.5A DE102022108997A1 (de) 2022-04-13 2022-04-13 Kolbenrohling, kolben und verfahren
PCT/EP2023/056651 WO2023198394A1 (fr) 2022-04-13 2023-03-15 Ébauche de piston, piston et procédé

Publications (1)

Publication Number Publication Date
EP4490334A1 true EP4490334A1 (fr) 2025-01-15

Family

ID=83436004

Family Applications (1)

Application Number Title Priority Date Filing Date
EP23712481.3A Pending EP4490334A1 (fr) 2022-04-13 2023-03-15 Ébauche de piston, piston et procédé

Country Status (5)

Country Link
US (1) US20250230779A1 (fr)
EP (1) EP4490334A1 (fr)
CN (1) CN217538859U (fr)
DE (1) DE102022108997A1 (fr)
WO (1) WO2023198394A1 (fr)

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2821176C2 (de) 1978-05-13 1982-12-09 Mahle Gmbh, 7000 Stuttgart Kolben mit Bodenplatte für Verbrennungsmotor
DE4014705C2 (de) 1990-05-08 1999-06-10 Mahle Gmbh Gekühlter Tauchkolben für Verbrennungsmotoren mit voneinander getrenntem Kolbenoberteil und Kolbenschaft
EP2295777B1 (fr) 2003-03-31 2016-12-07 Hitachi Metals, Ltd. Piston pour machine à combustion et son procédé de fabrication
DE102009032941A1 (de) * 2009-07-14 2011-01-20 Mahle International Gmbh Mehrteiliger Kolben für einen Verbrennungsmotor und Verfahren zu seiner Herstellung
DE102012111679A1 (de) * 2012-01-19 2013-07-25 Gesenkschmiede Schneider Gmbh Niedrig legierter Stahl und damit hergestellte Bauteile
WO2014198896A1 (fr) 2013-06-14 2014-12-18 Ks Kolbenschmidt Gmbh Procédé permettant de produire une couche de protection contre l'oxydation pour un piston destiné à être utilisé dans un moteur à combustion interne et piston pourvu d'une couche de protection contre l'oxydation
WO2017021565A1 (fr) * 2015-08-05 2017-02-09 Gerdau Investigacion Y Desarrollo Europa, S.A. Acier faiblement allié à résistance élevée et à résistance élevée à l'oxydation à chaud
DE102020211247A1 (de) 2020-09-08 2022-03-10 Federal-Mogul Nürnberg GmbH Kolben für einen Verbrennungsmotor, Verbrennungsmotor mit einem Kolben und Verwendung einer eisenbasierten Legierung

Also Published As

Publication number Publication date
US20250230779A1 (en) 2025-07-17
WO2023198394A1 (fr) 2023-10-19
CN217538859U (zh) 2022-10-04
DE102022108997A1 (de) 2023-10-19

Similar Documents

Publication Publication Date Title
DE102011085476A1 (de) Funktionsoptimierte Gestaltung einer Zylinderlaufbuchse
DE102010033879A1 (de) Verfahren zur Herstellung eines Kolbens für einen Verbrennungsmotor sowie Kolben für einen Verbrennungsmotor
DE102011013067A1 (de) Verfahren zur Herstellung eines Kolbens für einen Verbrennungsmotor
DE10209168B4 (de) Stahlkolben mit Kühlkanal
EP2513462A1 (fr) Procédé de fabrication d'un piston pour un moteur à combustion interne et piston fabriqué selon ce procédé
DE102008063947B4 (de) Kolben mit standardisiertem Kolbenboden bei variabler Kompressionshöhe
DE102016220136A1 (de) Verfahren zum Herstellen eines Gegenstandes mittels Laserschmelzen
EP2622197B1 (fr) Procédé de fabrication d'un perçage de ventilation dans un palier de butée de carter de vilebrequin d'un moteur à combustion interne à pistons alternatifs
EP4490334A1 (fr) Ébauche de piston, piston et procédé
EP1430211B1 (fr) Procede pour produire un piston ou une tete de piston pour un moteur a combustion interne
EP2604379A2 (fr) Procédé de fabrication d'une pièce métallique formée avec blindage
DE102021106120A1 (de) Verfahren zum befestigen von ventilsitzeinsätzen am aluminium-zylinderkopf
EP2976181B1 (fr) Procédé de production d'un piston pour un moteur à combustion interne
DE102018007215A1 (de) Kolben für einen Verbrennungsmotor, insbesondere eines Kraftfahrzeugs, sowie Verfahren zur Herstellung eines solchen Kolbens
DE102014017756A1 (de) Zylinderkopf für eine Verbrennungskraftmaschine und Verfahren zum Herstellen eines Zylinderkopfes
DE102012221858A1 (de) Kolben und Kolbenring-Anordnung mit einer gestuften Kolbenringnut
DE102010052578A1 (de) Kolben für eine Brennkraftmaschine
DE102008014664B4 (de) Verfahren zur Herstellung einer Zylinderlaufbuchse
EP2976180B1 (fr) Procédé de production d'un piston pour moteur à combustion interne
DE10230745B4 (de) Verfahren zur Herstellung eines Kolbens mit kurzer Kompressionshöhe
DE102023106531A1 (de) Kolben und verbrennungsmotor
DE102018214230A1 (de) Verfahren zur Herstellung eines Kolbens für einen Verbrennungsmotor, Kolben und Verbrennungsmotor
EP1225348A2 (fr) Elément d'un materiau composite avec une surface de rupture et procédé pour préparer un point de rupture
DE102022102051A1 (de) Kolbenrohling, Kolben und Verfahren
DE102017003562A1 (de) Nasse Zylinderlaufbuchse für eine Hubkolbenmaschine, insbesondere eines Kraftfahrzeugs

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20241009

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)