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 
  • F02F3/0015—Multi-part pistons
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
  • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
  • B23P15/10—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass pistons
• • 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
  • 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
  • F02F2003/0046—Multi-part pistons the parts being connected by casting, brazing, welding or clamping by crimping

Definitions

• the invention relates to a piston, in particular a cooling channel piston, an internal combustion engine and a method for its production, according to the features of the respective preamble of the independent claims.
• the piston consists after its completion of one piece and is composed of at least two parts, preferably exactly two parts, which are made separately from each other and then joined together.
• DE 10 2010 056 220 A1 describes an easily manufactured, for example, by casting, the first piston component, which can be connected to the second piston component, preferably by means of a friction welding process.
• EP 1 878 902 A2 describes the structure of a piston comprising an upper part and a lower part, which are supported via joining webs in the region of contact zones and connected to one another.
• a clamping connection arises here by a Twisting from the upper part to the lower part, comparable to a coupling. This is very complicated to handle.
• the invention is based on the object that the assembly of upper part and lower part to realize by a different joining than by a welding or soldering.
• the at least two piston parts have geometries corresponding to their connection region in order to effect a positive connection. Furthermore, the invention provides that the two parts are permanently joined together by a form fit to a one-piece piston.
• the positive connection and the correspondingly shaped areas of the upper part and the lower part, which form the positive locking, are designed so that the two parts are permanently and permanently connected to each other after execution of the positive locking operation. Since a piston of an internal combustion engine is a component made of a structural material (such as steel, aluminum, or the like), it may be necessary to have at least those portions required for positive engagement, but also the other entire upper part and the entire lower part, are heated to a much higher temperature than the ambient temperature before assembly.
• the positive connection between the lower part and the upper part takes place in a joining direction. A joining direction facilitates the handling and allows higher cycle times.
• a compound in which at least two components to be mechanically interlocked and due to their geometric shape to connecting components in the connection area the connection remains, is referred to as positive locking. Even if there is no power transmission between the components to be connected or the power transmission between the components to be connected is interrupted, the connection is maintained. Connections with undercut, riveted joints or dovetail joints are, for example, attributed to the positive connections.
• dovetail profile or connection is selected when viewed in cross-section, the shape of the spring or the groove remotely pronounced of the bifurcated shape of the tail of a swallow.
• the geometry of the spring or the groove in cross section corresponds to a trapezoid, a flat quadrilateral with two mutually parallel sides.
• the spring in cross-section with its tip connected to the element to be connected triangle, in particular isosceles triangle conceivable.
• the groove then has a corresponding corresponding cross-sectional shape for receiving the spring.
• Piston in particular cooling channel piston, an internal combustion engine comprising at least one lower part and at least one upper part, wherein the at least two Kolbentetle have in their connection region corresponding geometries to effect a positive connection.
• a robust connection between the at least one lower part of a piston and the at least one upper part of a piston is created, which meets the requirements for use in an internal combustion engine and thus long term conditions of operation withstands.
• the piston it is provided for the piston that corresponding geometries are designed as tongue and groove.
• a secure positive connection is created because the groove preferably has an undercut, which is accessed by the spring behind.
• the geometries required for this purpose can be produced industrially with reasonable effort.
• the piston it is provided for the piston that the spring, at least after joining, has the profile of a counter-spring to the groove. It is conceivable here that the spring already has the geometry of the groove before joining. During the joining process, a temporary, preferably elastic deformation of the spring takes place.
• the spring assumes the geometry of the spring only during the joining process. In this case, tolerances can be safely compensated from the manufacturing process, since the exact geometry of the fastener is formed only during the joining process. In both cases described, a robust positive connection is created between the at least one lower part and the at least one upper part of the piston.
• the groove has in its section the negative of a dovetail profile. This creates undercuts, which can be safely engaged behind by the spring. It thus creates a resilient positive connection.
• the spring has a dovetail profile at least after the joining in section.
• the shape of the spring may deviate in cross-section from the shape of the groove. After joining, the spring almost fills, preferably completely out the groove.
• the piston that the lower part and the upper part are permanently and non-releasably connected to one another after the form-locking process has been carried out.
• a joining step that can be done with high cycle times, one-piece pistons are produced. There is no additional heat input into the material, which could lead to a change in the structure within the alloy ' or of the metal. The material properties of the starting material are fully retained.
• the connection is thus reliably produced at high cycle times.
• the joining process can be described by the documentation of the force Joining be monitored. An elaborate monitoring of the joint in the subsequent, as required for example in a cohesive connection, is eliminated. Also reduces effort and costs for Handiingwerkmaschinee, since only one joining direction must be realized.
• At least one part, upper part or lower part is heated to a significantly higher temperature than the ambient temperature before assembly.
• one of the parts to be joined may be heated prior to assembly. If the spring and groove have different geometries prior to joining, heating a component facilitates finding the new shape of the spring.
• the spring assumes the geometry of the groove during the joining process. As a result, a play-free, positive connection is generated.
• the hot forming results in a non-detachable, at least form-fitting connection between the lower part and the upper part of a piston.
• the connection between the at least one lower part and the at least one upper part of the piston is formed such that it can not come loose during operation of an internal combustion engine.
• Trained is the positive connection according to the invention such that it counteracts the forces exposed during operation in an internal combustion engine. These are predominantly forces whose vector is parallel to the central longitudinal axis of the piston.
• FIG. 1 shows a sectional view of a two-part piston before joining
• 2A and B is a sectional view before and after the joining process
• Fig. 3A and B a joined piston blank
• FIG. 5 shows a further embodiment of a piston upper part (commercial vehicle piston) as a sectional view
• Fig. 6 is a sectional view after the joining of the piston of FIG. 5 and
• Figures 1 to 4B show a first embodiment of a piston according to the invention and Figures 5 to 7B show a further embodiment of a piston according to the invention.
• the same reference numerals are given for both embodiments.
• top, bottom, left, right, front, back, etc. refer exclusively to the example representation and position of the device and other elements selected in the respective figures. These terms are not intended to be limiting, that is to say that different positions and / or mirror-symmetrical design or the like may change these references.
• FIG. 1 shows an upper part 3 (here designed as a rotating part) and a lower part 2, which is designed as a forged lower part 2, a piston 1.
• an upper part 3 here designed as a rotating part
• a lower part 2 which is designed as a forged lower part 2
• piston 1 a piston 1.
• Other manufacturing methods and combinations are of course conceivable.
• the radially encircling groove 4 is executed as a Schwaibenschwanznut recognizable in the lower part 2, in which case two radially and concentrically mutually arranged grooves 4 are present. Alternatively, only one groove 4 or more than two grooves 4 may be present.
• the corresponding springs 5 are present, which engage in the executed as a dovetail groove 4 when the upper part 3 is joined to the lower part 2.
• other geometric shapes of the groove 4 are conceivable.
• the region 6 of the upper part 3 is heated before joining. These are in particular the spring 5 and the springs 5, which are intended to engage in the dovetail groove 4 and the dovetail grooves 4, respectively. Alternatively or additionally, the groove 4 itself can be heated.
• Figure 2 shows the state in which the upper part 3 is pressed or pressed onto the lower part 2, fn the upper view of Figure 2, the upper part 3 is not yet fully pressed onto the lower part 2. This is evident from the fact that the downwardly facing springs 5 are not yet fully pressed into the groove 4 and have not yet deformed. Only when further pressed or pressed by the upper part 3 in the direction of the lower part 2, there is a deformation of the springs 5 of the upper part 3 in the grooves 4 of the lower part 2, as can be seen in the lower illustration of FIG. Here are also facing each other joining surfaces 7 of the upper part 3 on the corresponding surfaces of the lower part 2 over the entire surface. The joining direction is identified by the reference symbol F in the figures.
• FIG. 3 shows a piston blank 8 designed and assembled according to FIGS. 1 and 2, which still has to be supplied to a finishing operation before it can be operationally installed in the cylinder of an internal combustion engine.
• Figures 4A and 4B finally show the finished finished piston 1, in the z. B. annular grooves 9 and valve pockets 10 have been introduced. In addition, there was a processing of the interior of the combustion chamber 1 1 1. At this point it should be noted that the parting plane 12 is stepped between the upper part 3 and lower part 2, but may also lie in the same plane. In addition, there are variations with regard to the parting plane 12 between the upper part 3 and the lower part 2. In Figure 4B is a parting plane 12 (viewed from above) between 7
• the top and middle annular groove 9 recognizable.
• the outer parting plane 12 may also be above or below it.
• a Riehikanalkolben is shown in Figures 4A and 4B, which concentrically around the combustion chamber 11 around a radially encircling cooling channel 13 has. Such a cooling channel may, but need not be present. The same applies to the combustion chamber trough 11.
• the design is not limited to such, as shown in Figures 4.
• the finished piston 1 has two opposite shaft wall sections 14, which are supported on the cylinder wall of the internal combustion engine during operation of the piston 1.
• the two supporting shaft wall sections 14 are connected to each other via recessed connecting walls 15, wherein in the connecting walls 15 in known per se, the pin bore 16 is arranged.
• other types of piston for internal combustion engines are conceivable, to which the method and the inventive construction are applicable.
• FIG. 5 shows an alternative embodiment of a piston blank 8 'of the upper part 3' of the piston according to FIGS. 1 to 4B r, wherein it can be seen that transfer bores 17 are present in this upper part 3 '.
• transfer bores 17 By means of these transfer bores 17, it is possible to exchange a cooling medium between the radially encircling outer cooling channel 13 and the inner inner region 18 of the piston.
• the piston has an outer (here radially encircling)
• Figures 6, 7A and 7B show a variant of a piston 1 ", which is specifically geared to the requirements in commercial vehicles (NPP)
• Figure 6 shows the piston blank 8", after which the upper part 3 "and the lower part 2" have been assembled according to the invention are.
• 7A and 7B show the finished piston 1 ", which has been supplied to the finishing operation
• the annular grooves 9 and further recesses 19 have been introduced above and below the annular grooves 9.
• Another significant advantage of the method according to the invention is the fact that no weakenings in the structure in the region of the upper part 3, 3 ', 3 "and of the lower part 2, 2", which are joined together, occur due to the form-locking connection according to the invention.

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

Applications Claiming Priority (3)

Publications (1)

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ID=51418880

Family Applications (1)

Country Status (5)

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• 2013
  • 2013-09-19 DE DE102013218764.5A patent/DE102013218764A1/de not_active Ceased
• 2014
  • 2014-02-13 US US14/776,814 patent/US20160025034A1/en not_active Abandoned
  • 2014-02-13 WO PCT/EP2014/052817 patent/WO2014139750A1/de active Application Filing
  • 2014-02-13 EP EP14706798.7A patent/EP2971715A1/de not_active Withdrawn
  • 2014-02-13 CN CN201480014646.3A patent/CN105143652A/zh active Pending

Non-Patent Citations (1)

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