US3760863A - Method for the manufacture of cast iron parts having internally arranged friction bearing surfaces - Google Patents

Method for the manufacture of cast iron parts having internally arranged friction bearing surfaces Download PDF

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Publication number
US3760863A
US3760863A US00043725A US3760863DA US3760863A US 3760863 A US3760863 A US 3760863A US 00043725 A US00043725 A US 00043725A US 3760863D A US3760863D A US 3760863DA US 3760863 A US3760863 A US 3760863A
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US
United States
Prior art keywords
core
cast iron
cooling
bore
casting
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Expired - Lifetime
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US00043725A
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English (en)
Inventor
E Weyersberg
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.)
Dr Ing HCF Porsche AG
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Dr Ing HCF Porsche AG
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.)
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Publication date
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D19/00—Casting in, on, or around objects which form part of the product
    • B22D19/08—Casting in, on, or around objects which form part of the product for building-up linings or coverings, e.g. of anti-frictional metal

Definitions

  • the core can take the form of a thin-walled steel bushing which is removed from the bearing bore after the cast iron part has cooled and is removed from the mold.
  • the core can be removed by either turning-out or pressing-out, and after removal of the core, the bore or at least a portion of the bore can be ground to the desired dimensions.
  • the core Prior to the casting process, the core can be subjected to either heating or cooling, and during the casting process, a cooling medium stream can be passed through the core.
  • the present invention relates to a method for the manufacture of cast iron parts having internally arranged friction bearing surfaces, and more particularly, to the manufacture of gray cast iron parts for rockerarms in internal combustion engines which are provided with a bearing bore which is produced by a core placed into the mold;
  • the steel bushing may be removed from the bore by means of turning, after removal of the casting from the mold. Especially with continuous or through bores, recesses or the like, the steel bushing may also be pressed out. Through proper dimensioning of the wall thickness of the steel bushing, it is possible to adjust the depth of the surface zone which is influenced by the higher cooling speed.
  • the present invention further provides that the steel bushing is preheated prior to the casting process in order to obtain a definite texture formation on the surface zones through one cooling speed or its temperature magnitude, respectively.
  • the bushing is so pre-heated that a cooling speed of about 500 C/min. is attained whereby a ledeboritic texture is formed at the surface zones which shows satisfactory running characteristics with sufficient hardne'ss.
  • the dissociation of carbide may be decreased so that a harder texture structure is provided at the surface zone.
  • a decrease in the cooling speed and a possible simultaneous increase of Si as an alloying constituent leads to an increase in the dissociation of carbide and therewith to a lesser hard texture structure in the surface zone.
  • the method of the present invention further provides for, passinga cooling stream through the bushing whereby a constant heat leak-off through the steelbushing is attained for an arbitrary time, and by this means the depth of the surface zone influenced by the increased heat leak-off speed may be arbitrarily varied.
  • a number of cast parts can be placed together in one mold for the manufacture of smaller continuous bores or recesses, respectively in cast iron parts, and in place of providing single steel bushings for each part, a common steel tube passing through a number of casting parts may be used.
  • the method of the present invention provides still a further measure for influencing the cooling speed by covering the steel bushings or steel tube with a layer of poor or non-heat conducting material.
  • the method of the present invention results in several advantages.
  • a heat conducting steel bushing in place of a core of non-heat conducting material, a higher cooling speed of the cast iron and, thereby, a greater hardness of the surface is obtained in the surface zones of bores or recesses of cast iron parts without creating more than an insignificant distortion of the recess, so that the desired friction surface or sliding surface may be produced through a simple mechanical treatment of the surface such as grinding.
  • a ledeboric texture structure with adjustment of the cooling speed in each case for a higher or lower share of non-dissociating carbide and therewith a greater or lesser hardness, a sufficient hardness as well as a satisfactory running characteristic of the surface is obtained.
  • FIGURE is a cross-sectional view of a rockerarm for an internal combustion engine manufactured in accordance with the method of the present invention.
  • the rockerarm 1 is made of gray cast iron and consists essentially of a first lever arm 2 operatively connected with a cam shaft and a second lever 3 operatively cooperating with a valve stem as well as a bearing bore 4.
  • surface zones 5 and 6 consist of a hard texture structure and are provided through insertion of corresponding ingot molds into a casting mold.
  • a surface zone of l to 2 mm. depth having a ledeboritic texture structure 7 is created at the same time along the friction bearing or sliding bearing surface 4' of the bearing bore 4 over which the rockerarm l is swingably supported on the rockerarm shaft.
  • the sole FIGURE shows a steel bushing 8 insertedinto the casting mold for the creation of the ledeboritic texture structure 7.
  • the steel bushing 8 is subject to a higher cooling speed of the cast iron at the surface zones along the friction bearing surface 4' of the bearing bore 4 and releases thereby the formation of a ledeboric texture structure.
  • the steel bushing 8 is removed from the bearing bore 4 through a turn-out operation and the friction bearing surface 4 is ground to the proper dimensions. It can be readily seen that no further finishing operation is required.
  • Method for the manufacture of cast iron parts comprising: inserting a core of a thin-walled steel bushing into a casting mold, casting the cast iron part in the casting mold, forming a bearing bore in the cast iron part by meaans of the core including cooling of the portion of the cast iron part adjacent the core at a predetermined starting rate of approximately 500C/min., removing the cast iron part from the casting mold, and removing the core from the bearing bore.
  • Method according to claim 1 further including subjecting the core to a temperature change process prior to casting of the part.
  • Method according to claim 1 further including passing a cooling medium stream through the core during casting and cooling of the part.
  • Method according to claim 1 including the step of covering the core with a layer of material having low heat conductivity.
  • Method according to claim 1 including forming a plurality of cast iron parts Simultaneously in one mold, wherein the cast iron parts form a continuous bore, and passing a single core through the bores of all the cast iron parts in lieu of individual cores for each bore.
  • Method according to claim 8 including subjecting the core to a temperature change process.
  • Method according to claim 1 including the step of cooling the portion of the cast iron part adjacent the core at the predetermined starting rate and cooling the other portions of the cast iron part at a different cooling rate.
  • Method according to claim 10 including dimensioning of the wall thickness of the core for assuring the cooling of the portion of the cast iron part adjacent the core at the predetermined starting rate.
  • Method according to claim 1 including dimensioning of the wall thickness of the core for assuring the cooling of the portion of the cast iron part adjacent the core at the predetermined starting rate.
  • bearing bore is provided with a hardened surface layer adjacent the core, and including the step of dimensioning the wall thickness of the core in accordance with a desired thickness of the hardened surface layer.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)
  • Detergent Compositions (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)
US00043725A 1969-06-11 1970-06-05 Method for the manufacture of cast iron parts having internally arranged friction bearing surfaces Expired - Lifetime US3760863A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19691929602 DE1929602A1 (de) 1969-06-11 1969-06-11 Verfahren zur Herstellung von Graugussteilen mit innenliegenden Gleitlagerflaechen

Publications (1)

Publication Number Publication Date
US3760863A true US3760863A (en) 1973-09-25

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ID=5736675

Family Applications (1)

Application Number Title Priority Date Filing Date
US00043725A Expired - Lifetime US3760863A (en) 1969-06-11 1970-06-05 Method for the manufacture of cast iron parts having internally arranged friction bearing surfaces

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US (1) US3760863A (enrdf_load_stackoverflow)
DE (1) DE1929602A1 (enrdf_load_stackoverflow)
FR (1) FR2045971B3 (enrdf_load_stackoverflow)
GB (1) GB1252875A (enrdf_load_stackoverflow)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100323213A1 (en) * 2009-06-19 2010-12-23 Trevor Aitchison Multilayer overlays and methods for applying multilayer overlays
US20130048701A1 (en) * 2011-08-31 2013-02-28 Prakash K. Mirchandani Methods of forming wear resistant layers on metallic surfaces
CN104747627A (zh) * 2013-12-31 2015-07-01 现代自动车株式会社 由异质材料制造的制动盘及其制造方法

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US256257A (en) * 1882-04-11 Chill for chilling metal
US345455A (en) * 1886-07-13 Henry bennett stanert
US950637A (en) * 1909-06-07 1910-03-01 John Walthart Latcher Casting apparatus.
US1391675A (en) * 1920-05-12 1921-09-27 Albert H Emery Art of producing hollow castings
US1393195A (en) * 1920-03-20 1921-10-11 Bradley Ross Edward Billet-casting
US1579743A (en) * 1923-04-25 1926-04-06 Jr John Harries Warlow Method of and means for casting steel or other ingots or castings
US2304879A (en) * 1940-05-15 1942-12-15 Joseph S Brazil Casting method
US2749587A (en) * 1949-02-21 1956-06-12 Walter Macfarlane & Company Lt Method of producing grey iron castings in preheated refractory coated male and female dies
US3483916A (en) * 1968-01-31 1969-12-16 Union Carbide Corp Ferro alloy casting process

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US256257A (en) * 1882-04-11 Chill for chilling metal
US345455A (en) * 1886-07-13 Henry bennett stanert
US950637A (en) * 1909-06-07 1910-03-01 John Walthart Latcher Casting apparatus.
US1393195A (en) * 1920-03-20 1921-10-11 Bradley Ross Edward Billet-casting
US1391675A (en) * 1920-05-12 1921-09-27 Albert H Emery Art of producing hollow castings
US1579743A (en) * 1923-04-25 1926-04-06 Jr John Harries Warlow Method of and means for casting steel or other ingots or castings
US2304879A (en) * 1940-05-15 1942-12-15 Joseph S Brazil Casting method
US2749587A (en) * 1949-02-21 1956-06-12 Walter Macfarlane & Company Lt Method of producing grey iron castings in preheated refractory coated male and female dies
US3483916A (en) * 1968-01-31 1969-12-16 Union Carbide Corp Ferro alloy casting process

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100323213A1 (en) * 2009-06-19 2010-12-23 Trevor Aitchison Multilayer overlays and methods for applying multilayer overlays
US9050673B2 (en) 2009-06-19 2015-06-09 Extreme Surface Protection Ltd. Multilayer overlays and methods for applying multilayer overlays
US20130048701A1 (en) * 2011-08-31 2013-02-28 Prakash K. Mirchandani Methods of forming wear resistant layers on metallic surfaces
US8800848B2 (en) * 2011-08-31 2014-08-12 Kennametal Inc. Methods of forming wear resistant layers on metallic surfaces
CN104747627A (zh) * 2013-12-31 2015-07-01 现代自动车株式会社 由异质材料制造的制动盘及其制造方法
US20150184712A1 (en) * 2013-12-31 2015-07-02 Hyundai Motor Company Brake disc manufactured from heterogeneous materials and method of manufacturing the same
US9562578B2 (en) * 2013-12-31 2017-02-07 Hyundai Motor Company Brake disc manufactured from heterogeneous materials and method of manufacturing the same
CN104747627B (zh) * 2013-12-31 2018-09-14 现代自动车株式会社 由异质材料制造的制动盘及其制造方法

Also Published As

Publication number Publication date
FR2045971B3 (enrdf_load_stackoverflow) 1973-03-16
GB1252875A (enrdf_load_stackoverflow) 1971-11-10
DE1929602A1 (de) 1970-12-17
FR2045971A7 (enrdf_load_stackoverflow) 1971-03-05

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