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

Definitions

• the present invention relates to a piston for an internal combustion engine, with a piston head and a piston skirt and with a ring portion and a cooling channel, according to the preamble of claim 1.
• a generic piston is known for example from DE 10 2006 056 013 A1.
• the piston comprises a piston head and one of them
• piston head has a ring portion
• piston rings can be arranged.
• a circumferential ring carrier is also provided in the region of the ring part.
• the piston is also provided with a circumferential cooling channel.
• the cooling channel is arranged at a distance from the piston crown and from the ring section within the piston. The disadvantage here is that such an arrangement of the cooling channel a
• Limitation represents the size of a piston recess on the piston crown.
• a ring carrier for a piston of an internal combustion engine is known from DE 101 34 293 A1.
• a sheet metal part of the ring carrier is open to a ring carrier part of the ring carrier to form a cooling channel together with the ring carrier part.
• an aluminum piston with a cooling channel is known, which is formed with a central constriction.
• the cooling channel is by a casting process formed in the piston and arranged radially within a ring carrier and spatially separated therefrom.
• the present invention addresses the problem of providing a piston of the generic type with an improved or at least alternative
• Piston recess distinguishes.
• the present invention is based on the general idea to arrange the cooling channel of the piston for an internal combustion engine at least partially directly to the ring part and in particular on the ring carrier of the piston and thus on the one hand to create space for forming a larger piston recess and on the other hand, the cooling, especially in the region of the ring section , too
• the cooling channel of the piston is formed so that it has a taper in cross-section approximately centrally.
• the piston according to the invention thus has a cooling channel, which is formed circumferentially in a piston head of the piston and has a substantially central cross-sectional taper.
• the Kol ben köpf further comprises said, circumferential ring section, in which said ring carrier, which is also circumferential, is arranged.
• the ring carrier now forms a wall section of the cooling channel, so that the cooling channel is at least partially disposed directly on the ring carrier and is in direct contact therewith.
• the cooling channel is at least partially disposed directly on the ring carrier and is in direct contact therewith.
• improved cooling in this area is ensured by the direct coupling of the cooling channel with the ring carrier.
• an improved cooling of the piston is achieved in the region of the piston recess, since the piston recess can be formed closer to the cooling channel, and the cooling channel can be placed closer to the piston crown.
• the special design of the cooling channel with the approximately centrally disposed circumferential taper serves in particular to achieve an improved heat transfer and thus the better cooling of the piston. In this case, this cross section is given along the axial direction of the piston.
• Cooling channel to a constriction so that a flowing through the cooling channel coolant is selectively accelerated and aligned on the one hand by the upward and downward movement of the piston and the constriction in the manner of a nozzle and on the other hand, now limited to a relatively narrow flow cross-section equal directed flow in the partial volume above and below the constriction is forced in each case into a roller-shaped flow. This causes a much higher flow velocity of the engine oil commonly used as a coolant along the surface of the cooling channel.
• the stabilization of the piston, in particular the piston head by means of the ring carrier is particularly necessary when the piston is made of a light metal, in particular aluminum or of an aluminum-containing material.
• the constriction of the cooling channel to form the cross section according to the invention is arranged approximately centrally in the cooling channel.
• the circumferential cooling channel which has a generally elongate, approximately in the axial direction, that is, parallel to the piston axis, extending cross-section, has a constriction approximately at half the axial height of the cooling channel.
• the cooling channel may be formed symmetrically in cross section, wherein a plane of symmetry or symmetry line or a point of symmetry in the region of the constriction of the cooling channel is arranged.
• an axisymmetric cross section may be kidney-shaped, while a point-symmetrical cross-section may be formed approximately dumbbell or eight-shaped.
• the upper and the lower part volume are shaped so that an axially passing through the constriction
• Coolant flow is taken off-center and substantially tangentially in a dome-shaped fillet at the top or bottom of the cooling channel.
• the kinetic energy of the oil is largely used to produce the inventively desired cylindrical movement in the upper or
• the oil jet after its passage through the constriction could alternatively strike the end area in a central jet.
• a central jet preferably in the upper and / or lower end region of the cooling channel in each case acting as a beam splitter circumferential rib present.
• the cooling channel according to the invention can be formed only above, only below or on both sides with such a beam splitter. In the latter case, the cooling channel according to the invention may also have a dumbbell-shaped, for example
• the ring carrier is radially inwardly thicker, in particular to ensure a better or more stable arrangement of the ring carrier in the region of the ring part.
• the decisive factor here is that an upper ring carrier wall in the axial direction and an axially lower ring carrier wall of the ring carrier in
• a preferred Ni-resist ring carrier has a smaller one
• Ring carrier is particularly advantageous when the piston is poured.
• the ring carrier can be used during or before the casting process in a corresponding mold. Accordingly, the
• Ring carrier prefers a cross-section which extends radially inwards
• the cross-section of the ring carrier can be shaped like a quadrangle, for example trapezoidal, triangular or polygonal or the like.
• the ring carrier is made of a nickel alloy such as Ni resist.
• the ring carrier on the vorzutul made of light metal for example made of aluminum or an aluminum alloy piston ends occurring in the first annular groove wear
• the piston is produced by a casting method, wherein the cooling channel is preferably formed by means of an insert in the piston.
• the cooling channel could also be in a, in
• Substantially annular casting may be formed which is attached to an otherwise forged piston.
• the insert forming the cooling channel is inserted in a corresponding casting mold for the production of the piston or the casting and is then surrounded with the material forming the piston.
• the insert may be configured as a sand core or salt core, which following the
• the insert part for forming the cooling channel is preferably a sheet metal part which is welded or soldered to the ring carrier and forms the cooling channel between the two.
• This has the advantage that the desired shape of the cooling channel can be realized by a simple forming of the designed as a sheet metal part insert.
• the cross-sectional shape of the cooling channel with its substantially central constriction can be produced comparatively easily without having to use relatively fragile salt cores due to the desired shape.
• the ring carrier forms, for example, a projecting into the cooling channel on the radially outer side protrusion.
• a suitable salt core from either axial direction could be placed on the ring carrier, a corresponding sheet metal part can be bent to fit after placing on the ring carrier.
• FIG. 1 shows a longitudinal section through a piston according to a first
• Fig. 2 is a longitudinal section through a piston according to a second
• Fig. 1 shows a piston 1, which is produced by means of a casting process.
• a mold 2 of the piston 1 is shown by means of a solid line, while a final shape 3 of the piston 1 is shown by a dashed line.
• the casting mold 2 is machined or milled, for example by a turning process.
• the piston 1 also has a ring carrier 4 and a cooling channel 5, which previously welded or soldered are implemented as an insert 6 and are accordingly introduced before pouring the piston 1 in a corresponding mold and
• the ring carrier 4 is preferably made of Ni resist and the cooling channel 5 made of austenitic steel / sheet metal.
• the piston 1 also comprises a piston head 7 and a ring part 8 circumferentially formed in the piston head 7.
• a plurality of annular grooves 9 serving to receive piston rings are formed, one of these annular grooves 9 being formed in the radially outer region of the annular carrier 4 is.
• the direction indicated by an arrow 18 radial direction is given with respect to an axial axis 10 of the piston 1 and extends correspondingly perpendicular thereto.
• the cooling channel 5 is arranged in regions directly on the ring carrier 4, so that the ring carrier 4 forms a wall section 11 of the cooling channel 5. Accordingly, the ring carrier 4 and the cooling channel 5 are in direct contact, so that the cooling channel 5 on the one hand radially as far outside can be arranged as possible and also ensures improved cooling of the ring section 8.
• the cooling passage 5 is formed to have a kidney-shaped cross section.
• the kidney-shaped cross-section is realized by means of a constriction 12 which lies in the region of approximately half of an axial height 13 of the cooling channel 5.
• This shape of the cooling channel 5 is realized by means of a forming of the designed as a sheet metal part 14 insert 6 to form the cooling channel 5.
• the kidney-shaped cooling channel 5 is formed substantially symmetrical, with a corresponding line of symmetry or plane of symmetry in the region of the constriction 12 of the cooling channel 5 extends.
• the ratios of the dimensions of the cooling channel 5 should preferably be as follows:
• the first relationship allows a sufficiently large volume to hold the coolant, whereas the second relationship is important for the acceleration of the coolant, such as oil.
• Relationships a particularly effective cooling, in particular by the roller-shaped movement of the coolant in the cooling channel 5 can be achieved.
• a cooling channel ceiling 21 of the cooling channel 5 is substantially dome-or
• the constriction 12 has in the shown
• Embodiment according to FIG. 1 the same distance from the cooling channel bottom 22 and the cooling channel ceiling 21, whereby the coolant is forced in the region of the cooling channel ceiling 21 in a circular circumferential flow, as indicated by the circular arrows, so that the coolant several times per piston stroke can interact with the wall of the cooling channel 5 in the region of a piston crown 16 and the piston recess 17.
• coolant of lower temperature is always accelerated by the constriction 12 and re-supplied.
• the radial dimension B of the substantially dome-shaped cooling channel ceiling 21 at its widest point at least equal to twice the radial dimension b of the constriction 12, ie B> 2xb. In this case, the training of a
• cylindrical flow favors that the coolant of lower temperature off-center and preferably enters tangentially into the rounding of the dome-shaped cooling duct ceiling and is thus not significantly hindered by the already deflected from the cooling duct ceiling 21 and back flowing coolant in its flow.
• the accelerated flow of oil through the constriction 12 leads to improved cooling of the ring carrier 4, to which also the increasing thickness of the ring carrier 4 contributes radially inward and thereby enlarged contact surface of the ring carrier 4 for the coolant.
• the roller-shaped movement of the coolant increases the flow velocity of the oil, inter alia, along the dome-shaped cooling channel ceiling 21 and there improves the heat transfer and thereby the cooling of the piston crown 16 and the bowl rim or piston recess 17.
• the piston 1 also has a piston stem 15, not shown in detail, which is arranged on the side projecting from a piston head 16 of the piston head 2 side of the piston head 2 and projects axially from the piston head 16.
• the piston 1 comprises in the piston head 16 a piston recess 17.
• Piston well 17 in particular in the radial direction larger form, for example, to achieve improved mixing or combustion of an air fuel mixture in an associated combustion chamber of an associated internal combustion engine.
• FIG. 2 shows a further variant of the piston 1 according to the invention. in the
• the cooling channel 5 is tilted tilted in the radial direction in the embodiment shown in FIG. Thereby occurs in the region of the constriction 12 substantially axially directed flow on the radially inner side in the dome-shaped cooling duct ceiling, while in the opposite direction on the radially outer side in the
• the cross section may, for example, have the shape of a slightly obliquely standing "8" according to Fig. 2.
• the shape of the cooling channel can more exactly match the shape of the piston recess 17 adapted and the heat transfer can be improved without having to deviate from an axial flow through the constriction 12.
• constriction 12 takes place from both radial sides of the cooling channel 5, so that the corresponding wall portion 1 1 in contrast to the straight
• the ring carriers 4 have a conical cross-section in cross-section with a radially inwardly enlarging cross-section.
• an axially lower ring carrier wall 19 and an axially upper ring carrier wall 20 of the ring carrier 4 are aligned in cross-section with each other and accordingly not parallel in the examples shown, with the terms below and above refer to the illustration shown.
• Such a design of the respective ring carrier 4 allows a better arrangement or a better grip of the ring carrier in the piston, in particular in a trained as Einlegteil 6 ring carrier. 4
• the ring carrier 4 shown in FIG. 1 has a trapezoidal cross-section, so that the wall portion 1 1, as mentioned, is straight in cross section.
• the ring carrier shown in FIG. 2 also has a trapezoidal cross section, wherein the wall portion 1 1 has a shape adapted to the centrally narrowed shape of the cooling channel 5 shape.
• the first relationship causes a sufficiently large space for receiving the coolant, whereas the second relationship the required
• Bi B 2 . All in all, with such a Cooling channel geometry a particularly effective cooling of the piston 1 can be achieved.

Landscapes

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

Priority Applications (5)

Applications Claiming Priority (2)

Publications (2)

Family

ID=49035570

Family Applications (1)

Country Status (7)

Families Citing this family (2)

Citations (3)

Family Cites Families (22)

• 2012
  • 2012-08-31 DE DE102012215541.4A patent/DE102012215541A1/de not_active Withdrawn
• 2013
  • 2013-08-20 WO PCT/EP2013/067302 patent/WO2014033011A2/de not_active Ceased
  • 2013-08-20 CN CN201380045679.XA patent/CN104603438B/zh not_active Expired - Fee Related
  • 2013-08-20 EP EP13753156.2A patent/EP2890883B1/de not_active Not-in-force
  • 2013-08-20 JP JP2015528957A patent/JP6340368B2/ja not_active Expired - Fee Related
  • 2013-08-20 BR BR112015004142A patent/BR112015004142A8/pt not_active Application Discontinuation
  • 2013-08-20 US US14/423,656 patent/US9664137B2/en not_active Expired - Fee Related

Patent Citations (3)

Also Published As

Similar Documents

Legal Events