Metal working – Method of mechanical manufacture – Prime mover or fluid pump making
Patent
1997-10-23
1999-12-28
Cuda, Irene
Metal working
Method of mechanical manufacture
Prime mover or fluid pump making
74569, B23P 1500
Patent
active
060064293
ABSTRACT:
A built-up camshaft has cam discs which are secured to a tube under mechanical prestress, are of annular design, and are inductively hardened all the way around at a boundary layer on their outer periphery before they are secured to the tube. The hardening of the boundary layer is formed in such a manner that, due to the hardening, high residual compressive stresses (at least -450 N/mm.sup.2) are produced in an at least approximately 0.5 mm deep boundary zone near the surface in such a manner that, even after the cam discs are mounted on the tube, the superimposing residual tensile stresses in the boundary zone, induced by the joining, only partly compensate the original residual compressive stresses, i.e. there are still only residual compressive stresses (at least -150 N/mm.sup.2) in the boundary zone near the surface even after the pressing-on. Sufficiently high residual compressive stress in the boundary zone can be produced by effecting the inductive heating of the cam disc in two stages. Specifically, first of all the cam disc is loaded with a medium-frequency alternating magnetic field and thus the entire annular body of the cam disc is preheated to at least 250.degree. C. but below the transformation temperature. The cam disc is then loaded with a second alternating magnetic field changed in its intensity and/or its frequency relative to the alternating magnetic field of the first stage, as a result of which only the boundary zone is heated up to the transformation temperature or below it. After the quenching of the cam disc heated in such a manner, the high residual compressive stresses appearing a boundary zone of sufficient depth.
REFERENCES:
patent: 3598458 (1971-08-01), Evans
patent: 4584034 (1986-04-01), Hagiwara et al.
patent: 4675488 (1987-06-01), Mucha et al.
patent: 4744836 (1988-05-01), Pfaffmann
patent: 4749834 (1988-06-01), Mucha et al.
patent: 4785147 (1988-11-01), Mucha et al.
patent: 4798178 (1989-01-01), Greulich et al.
patent: 4855551 (1989-08-01), Mucha et al.
patent: 4905538 (1990-03-01), Watanabe et al.
patent: 5004370 (1991-04-01), Swars
patent: 5009395 (1991-04-01), Pfaffmann
patent: 5037490 (1991-08-01), Swars et al.
patent: 5039360 (1991-08-01), Brugarolas et al.
patent: 5308408 (1994-05-01), Katila
German article entitled "Prazisions-Stahlrohr ist Herz der gebauten Nockenwelle", Seite 48, VDI nachrichten, Nr. 39 / Sep. 26, 1986.
German catalog entitled "Gebaute Nockenwellen" by Presta Someflor-date unknown.
Geschaftsbericht 1988 der Oerlikon-Buhrle Holding AG und des Oerlikon-Buhrle Konzerns (Stand Dec. 31, 1988).
German article entitled "Kraft und Formschuluss halten gestinterte Nocken auf gangige Rohre" by Von Michael Pyper, Seite 46, VDI nachrichten, Nr. 39 / Sep. 25, 1987.
German article entitled "Einfluss von Eigenspannungen auf die Werkstoffanstrengung in walzbeanspruchten Bauteilen" by E. Broszeit et al., Z. Werkstofftechnik 16, (1985). pp. 19-24.
German article entitled "uber rontgenographische und mechanische Eigenspannungsanalysen an induktiv geharteten Nocken aus 100Cr6", Karlsruhe University, Apr. 8, 1994, pp. 1-9.
German article entitled "uber rontgenographische und mechanische Eigenspannungsanalysen an induktiv geharteten, aufgepressten Nocken aus 100Cr6", Karlsruhe University, Apr. 21, 1994, pp. 1-5.
German article entitled "uber rontgenographische und mechanische Eigenspannungsanalysen sowie Restaustenitbestimmungen an induktiv geharteten Nocken aus 100Cr6", Karlsruhe University, Jun. 2, 1994, pp. 1-6.
German article entitled "uber rontgenographische und mechanische Eigenspannungsanalysen an einer induktiv geharteten Nocken aus 100Cr6", Karlsruhe University, Mar. 1, 1994, pp. 1-4.
German article entitled "Untersuchungen fur Fa. Presta: Gebaute Nockenwelle fur Ford (USA) mit Nocken aus 100 Cr 6 GKZ HI", Nov. 2, 1993.
Automotive Technology International '92 entitled "Selective surface treatmentof gears by induction profile hardening" by George D. Pfaffmann, pp. 143, 145, 146, 149 and 150.
German article entitled "Eigenspannungen; Definition und Entstehungsursachen" by K.H. Kloos, Deutshche Gesellschaft fur Metallkunde E.V., 1979.
German article entitled "Walzfestigkeit einsatzgeharteter Bauteile" by H. Stangner et al., Carl Hanser Verlag, Muenchen 1990, pp. 224-229.
Bid dated Feb. 3, 1988 and invoice of Feb. 26, 1988.
Duell Christoph
Hanisch Gustav
Cuda Irene
Daimler-Chrysler AG
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