Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21H—MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS, WHEELS, RINGS, BARRELS, BALLS
  • B21H7/00—Making articles not provided for in the preceding groups, e.g. agricultural tools, dinner forks, knives, spoons
  • B21H7/18—Making articles not provided for in the preceding groups, e.g. agricultural tools, dinner forks, knives, spoons grooved pins; Rolling grooves, e.g. oil grooves, in articles
  • B21H7/182—Rolling annular grooves
  • B21H7/185—Filet rolling, e.g. of crankshafts
• • 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
  • B23P9/00—Treating or finishing surfaces mechanically, with or without calibrating, primarily to resist wear or impact, e.g. smoothing or roughening turbine blades or bearings; Features of such surfaces not otherwise provided for, their treatment being unspecified
  • B23P9/02—Treating or finishing by applying pressure, e.g. knurling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B5/00—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor
  • B24B5/36—Single-purpose machines or devices
  • B24B5/42—Single-purpose machines or devices for grinding crankshafts or crankpins
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C3/00—Shafts; Axles; Cranks; Eccentrics
  • F16C3/04—Crankshafts, eccentric-shafts; Cranks, eccentrics
  • F16C3/06—Crankshafts
  • F16C3/08—Crankshafts made in one piece
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49229—Prime mover or fluid pump making
  • Y10T29/49231—I.C. [internal combustion] engine making
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49229—Prime mover or fluid pump making
  • Y10T29/49286—Crankshaft making

Definitions

• the invention relates to a method for finishing the bearing points on main and connecting rod bearing journals of crankshafts for motor vehicle engines, the crankshafts being rounded between the bearing points and the transitions adjacent to the bearing points, such as cheeks or pass bearings.
• Deep rolling rollers which have a diameter of approximately 15 mm and a rounding radius of approximately 1.3 mm, are pressed with defined force into the radii or recesses which limit the respective bearing point of the main or connecting rod bearing journal on both sides. Pressing in the hard deep rolling rollers creates a plastic deformation between the transition, for example the cheek or the thrust bearing of the crankshaft, and the bearing point and in this way brings a state of residual compressive stress into the crankshaft, which increases the fatigue strength of the crankshaft. Part of the width of the bearing point is required for deep rolling.
• recesses or fillets increase the stress level on crankshafts under bending and torsional stress, because they also weaken the diameter at the transition to the cheek. This applies equally to the main and pin bearings, so that the stress at the transition to the cheek increases as a result of the punctures.
• DE 198 33 363 A1 discloses a “method for turning machining of rotating surfaces on workpieces, preferably on crankshafts, and a disk-shaped tool for carrying out the method”
• the puncture and bearing points are fine-machined by finishing good surface quality and low roughness at the machining points are achieved, which increases the fatigue strength of the crankshaft.
• the object of the present invention is to achieve bearings of the greatest possible width on a crankshaft and at the same time to significantly increase their fatigue strength.
• crankshaft This problem is solved by fine machining the crankshaft.
• this can be a crankshaft, which already has low manufacturing tolerances in its preprocessing, for example by casting, forging and subsequent hardening.
• crankshafts can already be machined that already have a machining function Processing, for example by milling, have been subjected to and then undergo finishing. Such crankshafts can also have been hardened after roughing.
• the residual compressive stress state of the crankshaft is largely preserved. In this way, wider bearing points can be created than was previously the case. This is possible by not touching the radius in the transition between the bearing and the adjacent cheek, but only taking away material at the edge of the rolled-in zone caused by deep rolling, in which the grinding wheel or the tool with which the bearing is finished. As a result, the material removal during finishing of the bearing points can be kept low and is only between 0.1 and 0.3 mm.
• the method is therefore particularly suitable for the fine machining of crankshafts hardened on the running surface of the bearings, the depth of penetration of the hardening being small due to the small amount of material removed.
• the rolling depth of the rounding results from the required increase in fatigue strength. It is usually around 0.2 mm. In comparison to deep-groove recesses, the depth of the rounding can be less.
• the finished machining of the bearing point can be carried out either with an undefined cutting edge, for example by grinding, or with a specific cutting edge, for example by milling, turning, broaching, turning broaching or turning-turning broaching.
• the distance on both sides between the transitions and the respective bearing point is determined by the width of the finishing tool. It is between 0.5 and 5 mm, preferably 1 mm.
• crankshaft obtained in this way is characterized by tangent radii between the respective bearing points and their transitions.
• FIG. 2 shows a section of a bearing journal of a crankshaft according to FIG. 1,
• the crankshaft 1 has two main bearing journals 2 and a crank bearing journal 3.
• the crankshaft 1 is rotatably mounted in the engine block (not shown) of a motor vehicle engine with the two main bearing journals 2 about the axis of rotation 4.
• the axis of rotation 5 of the crank pin 3 is removed from the axis of rotation 4 of the crankshaft 1 by the distance 6, which corresponds to the stroke.
• the transitions between the two main bearing journals 2 and the pin bearing journal 3 form the two cheeks 7. Between the main bearing 2, the pin bearing journal 3 and the respective transitions 7, grooves 8 are provided.
• the theoretically available largest bearing width 9 is reduced by the two fillets 8 to the actually available bearing width 10, as can be seen in FIG. 2.
• the bearing point 11 which belongs to a main 2 or a pin journal 3, is now rolled with the help of a deep rolling roller (not shown).
• the rounding radius 12 of the deep rolling roller should be approximately 1.2 mm. It is rolled down to a rolling depth 13 of approximately 0.2 mm.
• the bearing point 11 can be machined, be it pre-processed by milling, turning or broaching and then also hardened.
• a theoretically maximum achievable width 22 of the bearing point 11 cannot, however, be achieved as long as it is provided that in the final machining of the main 2 or pin bearing journal 3, a removal 18 or 20 of the bearing point 11 should also take place.
• the bearing 11 can also be machined with a milling cutter or a broaching tool with a small depth of cut.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Agronomy & Crop Science (AREA)
• Ocean & Marine Engineering (AREA)
• Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
• Rolling Contact Bearings (AREA)
• Milling Processes (AREA)
• Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=30775042

Family Applications (1)

Country Status (6)

Cited By (3)

Families Citing this family (14)

Citations (8)

Family Cites Families (9)

• 2002
  • 2002-08-06 DE DE10235957A patent/DE10235957B4/de not_active Revoked
• 2003
  • 2003-08-02 US US10/521,144 patent/US7827684B2/en not_active Expired - Fee Related
  • 2003-08-02 EP EP03784155A patent/EP1526945B1/de not_active Expired - Lifetime
  • 2003-08-02 AU AU2003258563A patent/AU2003258563A1/en not_active Abandoned
  • 2003-08-02 WO PCT/EP2003/008575 patent/WO2004014600A1/de not_active Ceased
  • 2003-08-02 JP JP2004526858A patent/JP2006500230A/ja active Pending
  • 2003-08-02 DE DE50312802T patent/DE50312802D1/de not_active Expired - Lifetime

Patent Citations (8)

Non-Patent Citations (1)

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