US3506501A - Die-quenched crankshaft - Google Patents

Die-quenched crankshaft Download PDF

Info

Publication number
US3506501A
US3506501A US553142A US3506501DA US3506501A US 3506501 A US3506501 A US 3506501A US 553142 A US553142 A US 553142A US 3506501D A US3506501D A US 3506501DA US 3506501 A US3506501 A US 3506501A
Authority
US
United States
Prior art keywords
crankshaft
die
quenching
hardness
journals
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Lifetime
Application number
US553142A
Other languages
English (en)
Inventor
Raymond H Hays
Jack E Sansom
Kenneth D Gladden
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.)
Caterpillar Inc
Original Assignee
Caterpillar Tractor Co
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.)
Filing date
Publication date
Application filed by Caterpillar Tractor Co filed Critical Caterpillar Tractor Co
Application granted granted Critical
Publication of US3506501A publication Critical patent/US3506501A/en
Assigned to CATERPILLAR INC., A CORP. OF DE. reassignment CATERPILLAR INC., A CORP. OF DE. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: CATERPILLAR TRACTOR CO., A CORP. OF CALIF.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/30—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for crankshafts; for camshafts
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/62—Quenching devices
    • C21D1/673—Quenching devices for die quenching
    • 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
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/902—Metal treatment having portions of differing metallurgical properties or characteristics
    • Y10S148/904—Crankshaft
    • 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
    • Y10T74/00—Machine element or mechanism
    • Y10T74/21—Elements
    • Y10T74/2173—Cranks and wrist pins

Definitions

  • a multi-throw crankshaft is produced by a novel heat treating method which results in a finished crankshaft having a carbon content of .Z4-.40% case hardened to a substantially martensitic case over substantially its entire outer surface to a surface hardness of Rockwell C 44-54; and having a depth of hardness of .G60-.200 inch.
  • This invention relates to a new improved die-quench hardened crankshaft and die-quenching apparatus and method for producing the same.
  • the current commercial practice of processing forged steel crankshafts is to heat and quench the entire surface for grain refinement and subsequently temper for producing a machineable hardness. After cold straightening and basic machining, the bearing surfaces are induction hardened, reheated to tempering temperature, and then finally finish ground. In some cases the bearing fillets are shot peened prior to final finishing to increase fatigue strength.
  • the tempering temperature of the crankshafts has been raised from 540 to 740 F. to increase the ductility in the crank surface to prevent longitudinal cracking in field service and, unfortunately, the hardness level has been lowered from Rockell C 49--57 to the present Rockwell C 40-46. This in turn has reduced the fatigue strength and wear-life of the crankshafts.
  • a further problem is that if a complete crankshaft is heated and immediately quenched in an open quenching tank, distortion is so great that considerable time is consumed in straightening the cold crankshaft to make it usable. This is not only objectionable from a cost standpoint but it has been proven that when a piece of steel "ice is straightened following heat treatment, some areas are structurally weakened. In many cases, the distortion is so great that it cannot be corrected within the desired limits.
  • crankshafts are again straightened and a peening operation is done in the area of the pin and main journals.
  • This operation is necessary on present production crankshafts to alleviate undesirable residual stresses caused by the sharp transition between the hardened and relatively unhardened portions of the crankshaft formed by the induction hardening in the fillet area. This tends to relieve the stressed area between the hardened portion of the bearing surfaces and the fillets and eliminate cracks that generally start in this area if no peening is done.
  • the present invention provides a low carbon content crankshaft which is completely die-quench hardened after substantially all machining operations have been performed thereon and which eliminates the need for the straightening process previously required, the shot peening operation, and the plugging of the crankshaft oil holes. Since low carbon quenched and tempered steels are tougher than high carbon steels at the same hardness level, it is possible to use a low carbon steel at a higher hardness level with no increase in susceptibility to longitudinal cracking, but with marked improvement in fatigue life. As a result of the invention, the final crankshaft hardness is of a higher value, such as Rockwell C 49-54, than that attainable previously without encountering cracking problems, etc.
  • the novel die-quenching apparatus of the present invention it is possible to harden the entire surface of the crankshaft since when placed within the die the crankshaft is straightened and properly held while jets of water under pressure drastically quench the journals, thereby achieving an excellent surface hardening pattern. While the quenching process is taking place, the entire fixture and crankshaft are submerged and, due to the greatly agitated water from the jets, the hardness pattern is continued out into the cheeks and/ or throws of the crankshaft.
  • the low carbon content die-quench hardened crankshaft of the present invention has numerous other advantages such as increased fatigue life, higher surface hardness, elimination of longitudinal stress cracking, greater core strength and quench hardened llets. Moreover, a more economical grade of steel can be used than was previously possible.
  • FIG. 1 is a side elevation of one embodiment of diequenching apparatus constructed in accordance with the invention
  • FIG. 2 is a partial cross section taken on the line II--II of FIG. 1;
  • FIG. 3 is a plan view taken on the line III-III of FIG. 2;
  • FIG. 4 is a cross sectional view taken on the line IV-IV of FIG. 2;
  • FIG. 5 is a longitudinal view, partially in section, of a modified embodiment of die-quenching apparatus constructed in accordance with the invention.
  • FIG. 6 is a cross sectional view taken on the line VI-VI of FIG. 5;
  • FIG. 7 is a cross sectional view taken on the line VII-VII of FIG. 5.
  • the die-quenching apparatus of the invention comprises a movable upper platen 10 adapted to cooperate with a work supporting lower platen 12.
  • the platens 10 and 12 are respectively provided with a plurality of upper 14 and lower 16 die blocks which are adapted to receive therebetween a cylindrical workpiece such as the multi-throw crankshaft 18, on which the quenching operation is to be performed.
  • the die blocks are of like construction, they are of different heights and in different locations, to secure the respective journals of crankshaft 18 in proper position.
  • the lower platen 12 is provided with a plurality, preferably four, of spring loaded buttons 20 which support the crankshaft by its cheeks 22 when it is first placed in the apparatus.
  • buttons 20 prevent the crankshaft journals 24 from coming into contact with the cold metal of the die blocks 16 until the upper platen 10 is lowered into place for commencement of the straightening and quenching operation.
  • Contact of the hot journals with the relatively cold die blocks for any length of time prior to application of the quench water effects a mild quench of the contact area and is detrimental to the quenching operation.
  • the platens 10 and 12 and die blocks 14 and 16 are of hollow construction, the die blocks being secured to the platens by suitable retaining means 26 and alignment pins 28.
  • a plurality of conduits, as indicated at 30 and 32, are connected to the platens allowing water under pressure to be directed through the platens to the die blocks.
  • the upper die blocks 14 and lower die blocks 16 have generally cylindrically shaped opposed surfaces 34 for substantially surrounding the crankshaft 18 whenthe platens are in closed position.
  • Two or more protruding pads 36 are suitably spaced about each die block surface for contact with and support of the crankshaft journals 24.
  • Suitable retaining bolts 38 are provided for securing and adjusting the pads 36 with respect to their respective die blocks. Shims 40 can be removed or added between the pads and their respective blocks so as to shift the workpiece either laterally or vertically.
  • a plurality of small passageways 42 are provided in both the cylindrical surfaces 34 of the die blocks and the pads 36 to allow jets of water during the quenching operation to contact as much of the crankshaft journal surfaces as possible. It is important that the external surfaces of the pads 36 be shaped so as to make minimal contact with the journals during the quenching operation. Although the pads are shown with arcuately shaped external surfaces, these surfaces could be of any other suitable shape such, for example, as triangular with radiused corners providing the support for the various journals.
  • the upper platen and lower platen 51 receive water through ports 52.
  • Support blocks 54 and 56 Suitably secured to each of the platens, and in uid communication therewith, are supporting blocks 54 and 56.
  • Upper and lower die blocks 58 and 60 are secured to their respective supporting blocks by retaining bolts 62, the bolt heads of which are accessible through normally plugged apertures 64.
  • the pads 66 are an integral part of the die blocks 58 and 60.
  • the pads 66 are integrally formed on the die blocks, lateral and vertical adjustment thereof must be made via the die blocks 58 and 60.
  • the die blocks are adjusted vertically by changing shims 74 located between the die blocks and their respective supporting blocks.
  • an inverted T-shaped bracket 75 is fastened to the lower platen by means of bolts 76 and alignment pins 78.
  • a bifurcated leg 80 Located at the mid-portion of the bar of the T-shaped bracket is a bifurcated leg 80 which closely receives the support block 56.
  • Integrally formed on the support block 56 are a pair of spaced arms 82 which straddle the leg 80 of -bracket 75.
  • the support block 56 is adjustably secured to the bracket by means of fasteners 84 adapted to be received in oversized holes 86 formed in the arms 82. It will be readily understood that after loosening fasteners r84 the support block 56 and its associated die block 60 may be shifted horizontally by removing or adding shims 88 and loosening or tightening an adjusting screw 90.
  • Multi-throw crankshafts having a substantially martensitic case may now be produced with the following properties and characteristics; carbon content: .Z4-.40% C.; surface hardness: Rockwell C 44-55; depth of hardness: .G60-.200 inch (as measured five Rockwell C points below the surface hardness). Test results have indicated that the above crankshafts, ⁇ when die-quenched in the apparatus of the invention, have a Total Indicator Runout of less than .020 inch.
  • crankshaft In operation, immediately after the crankshaft has been furnace heated to its austenitizing temperature, it is placed in the lower platen and supported above the lower die blocks by the spring loaded buttons.
  • the buttons prevent the crankshaft journals from coming into contact with the die pads until a very short time prior to the beginning of the quenching cycle.
  • the upper die is then moved into position forcing the spring loaded buttons downwardly which allows the crankshaft to be clamped in position as shown in FIGS. 2 and 5.
  • fluid quenchant preferably water under very high pressure
  • fluid quenchant preferably water under very high pressure
  • the entire crankshaft is submerged and subjected to a drastic-quench so as to cause the hardness case to be extended over the entire crankshaft.
  • the heat treat pattern is distributed evenly throughout the entire exposed surfaces of the crankshaft including the oil hole surfaces inside the crankshaft. It is to be understood that the submersion process could be eliminated by providing sufficient water jets in the die-quenching apparatus to spray the entire crankshaft.
  • Method of heat treating a steel multi-throw crankshaft containing about .Z4-40% carbon comprising: furnace heating the entire crankshaft to its austenitizing temperature; placing said crankshaft in a die-quenching fixture; closing said dies about said crankshaft and establishing minimal surface contact between said crankshaft journals and said dies While rmly maintaining said crankshaft in xed axial alignment; and drastically quenching said crankshaft by spraying liuid quenchant under high pressure through said -xture and over substantially the entire surface thereof to produce an essentially martinsitic case over the surface of said multi-throw crankshaft.
  • a carbon steel multi-throw die-quenched crankshaft having a carbon content of about .24-40%; case hardened to a substantially martensitic case over substantially its entire surface to a surface hardness of Rockwell C 44-54; and having a depth of hardness of .G60-.200 inch.
  • a multi-throw crankshaft as set forth in claim 3 having in its unstraightened condition a total indicator runout of less than .020 inch,
  • CLAIM l line 2 "40%” should read 40%
  • CLAIM 3 line 2 "40%” should read .40%

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Articles (AREA)
  • Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
US553142A 1966-05-26 1966-05-26 Die-quenched crankshaft Expired - Lifetime US3506501A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US55314266A 1966-05-26 1966-05-26

Publications (1)

Publication Number Publication Date
US3506501A true US3506501A (en) 1970-04-14

Family

ID=24208286

Family Applications (1)

Application Number Title Priority Date Filing Date
US553142A Expired - Lifetime US3506501A (en) 1966-05-26 1966-05-26 Die-quenched crankshaft

Country Status (4)

Country Link
US (1) US3506501A (ref)
JP (1) JPS4939368B1 (ref)
BE (1) BE698170A (ref)
GB (2) GB1190951A (ref)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4057230A (en) * 1976-03-03 1977-11-08 Caterpillar Tractor Co. Die quench machine and method
US5492308A (en) * 1992-12-28 1996-02-20 Neturen Co., Ltd. Constrained quenching apparatus and heat treatment apparatus
US6048418A (en) * 1998-06-16 2000-04-11 Sterling Detroit Company Ring forming apparatus and heat treating process
US20110094282A1 (en) * 2009-10-23 2011-04-28 Thyssenkrupp Umformtechnik Gmbh Method and hot forming system for producing a hardened, hot formed workpiece
CN115505716A (zh) * 2022-10-25 2022-12-23 青岛德盛机械制造有限公司 一种曲轴热处理工艺及系统

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005024292A1 (de) * 2005-05-27 2006-11-30 Volkswagen Ag Härten eines Rohteiles für eine Low Cost-Fertigung

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1742739A (en) * 1928-10-31 1930-01-07 Bertis H Urschel Tempering machine
US1924296A (en) * 1929-02-11 1933-08-29 Linde Air Prod Co Heat treatment of crank shafts
US2255103A (en) * 1938-10-15 1941-09-09 Ohio Crankshaft Co Equipment for electric heating
US2343889A (en) * 1938-10-15 1944-03-14 Ohio Crankshaft Co Apparatus for electric heating
US2492434A (en) * 1942-12-08 1949-12-27 Mueller Co Projectile quenching apparatus
US2599575A (en) * 1945-02-14 1952-06-10 Timken Axle Co Detroit Shaft
US2709077A (en) * 1954-04-26 1955-05-24 Mederic E Berard Device for prevention of tool deformation during hardening
US3108913A (en) * 1961-03-16 1963-10-29 Ohio Crankshaft Co Crankshafts and method of hardening same
US3305409A (en) * 1962-12-26 1967-02-21 Int Harvester Co Heat process for crankshafts

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1742739A (en) * 1928-10-31 1930-01-07 Bertis H Urschel Tempering machine
US1924296A (en) * 1929-02-11 1933-08-29 Linde Air Prod Co Heat treatment of crank shafts
US2255103A (en) * 1938-10-15 1941-09-09 Ohio Crankshaft Co Equipment for electric heating
US2343889A (en) * 1938-10-15 1944-03-14 Ohio Crankshaft Co Apparatus for electric heating
US2492434A (en) * 1942-12-08 1949-12-27 Mueller Co Projectile quenching apparatus
US2599575A (en) * 1945-02-14 1952-06-10 Timken Axle Co Detroit Shaft
US2709077A (en) * 1954-04-26 1955-05-24 Mederic E Berard Device for prevention of tool deformation during hardening
US3108913A (en) * 1961-03-16 1963-10-29 Ohio Crankshaft Co Crankshafts and method of hardening same
US3305409A (en) * 1962-12-26 1967-02-21 Int Harvester Co Heat process for crankshafts

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4057230A (en) * 1976-03-03 1977-11-08 Caterpillar Tractor Co. Die quench machine and method
US5492308A (en) * 1992-12-28 1996-02-20 Neturen Co., Ltd. Constrained quenching apparatus and heat treatment apparatus
US6048418A (en) * 1998-06-16 2000-04-11 Sterling Detroit Company Ring forming apparatus and heat treating process
US20110094282A1 (en) * 2009-10-23 2011-04-28 Thyssenkrupp Umformtechnik Gmbh Method and hot forming system for producing a hardened, hot formed workpiece
CN115505716A (zh) * 2022-10-25 2022-12-23 青岛德盛机械制造有限公司 一种曲轴热处理工艺及系统

Also Published As

Publication number Publication date
GB1190952A (en) 1970-05-06
JPS4939368B1 (ref) 1974-10-25
GB1190951A (en) 1970-05-06
BE698170A (ref) 1967-11-08

Similar Documents

Publication Publication Date Title
Tekeli Enhancement of fatigue strength of SAE 9245 steel by shot peening
US3661655A (en) Metallic articles and the manufacture thereof
US3377214A (en) Method for hardening crankshaft
US3506501A (en) Die-quenched crankshaft
DE3910959C2 (de) Verfahren zum Herstellen von Wälzlagerelementen aus durchhärtendem Wälzlagerstahl
US3944444A (en) Method for heat treating cylindrical products
US6270595B1 (en) Bushing for crawler belt and method of manufacture
US3589697A (en) Die-quenched crankshaft
US3884730A (en) Machine element of surface-hardened steel having an improved resistance against wear, heat, and mechanical stress
US3466202A (en) Method of making wear resistant spring leaf
US2170130A (en) Method of and apparatus for hardening a metal article
US6030471A (en) Method for producing a hardened wheel
Dossett Introduction to cast iron heat treatment
US5049207A (en) Heat treatment process for bushing used in track of endless track tractor
US20030070737A1 (en) High-hardness, highly ductile ferrous articles
JPH03166320A (ja) トラックブッシュおよびその製造方法
US2310987A (en) Grinding ball and the method of making the same
US1924296A (en) Heat treatment of crank shafts
US2875109A (en) Method for the isothermal treatment of alloys after casting
Totten et al. Advances in polymer quenching technology
Savićević et al. Influece of the austempering temperature on the tensile strength of the austempered ductile iron (ADI) samples
EP0339152B1 (en) Heat treatment process for bushing used in track of endless track tractor
Grum Residual stresses in induction hardened steels
Üllen et al. The Characterization After Normalizing Treatment of Hot Forged 16MnCr5 and 20MnCr5 Cementation Steels
US3419260A (en) Wear resistant leaf spring

Legal Events

Date Code Title Description
AS Assignment

Owner name: CATERPILLAR INC., A CORP. OF DE.,ILLINOIS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:CATERPILLAR TRACTOR CO., A CORP. OF CALIF.;REEL/FRAME:004669/0905

Effective date: 19860515

Owner name: CATERPILLAR INC., 100 N.E. ADAMS STREET, PEORIA, I

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:CATERPILLAR TRACTOR CO., A CORP. OF CALIF.;REEL/FRAME:004669/0905

Effective date: 19860515