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GB2167524A - Camshafts for internal combustion engines - Google Patents

Camshafts for internal combustion engines Download PDF

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Publication number
GB2167524A
GB2167524A GB08511181A GB8511181A GB2167524A GB 2167524 A GB2167524 A GB 2167524A GB 08511181 A GB08511181 A GB 08511181A GB 8511181 A GB8511181 A GB 8511181A GB 2167524 A GB2167524 A GB 2167524A
Authority
GB
United Kingdom
Prior art keywords
shaft
camshaft
ribs
sintered members
sintered
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.)
Withdrawn
Application number
GB08511181A
Other versions
GB8511181D0 (en
Inventor
Alberto Bimbi
Luciano Golzio
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.)
TECNAMOTOR SpA
Original Assignee
TECNAMOTOR SpA
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 TECNAMOTOR SpA filed Critical TECNAMOTOR SpA
Publication of GB8511181D0 publication Critical patent/GB8511181D0/en
Publication of GB2167524A publication Critical patent/GB2167524A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01LCYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/02Valve drive
    • F01L1/04Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • F01L1/047Camshafts
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16DCOUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D1/00Couplings for rigidly connecting two coaxial shafts or other movable machine elements
    • F16D1/06Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16HGEARING
    • F16H53/00Cams ; Non-rotary cams; or cam-followers, e.g. rollers for gearing mechanisms
    • F16H53/02Single-track cams for single-revolution cycles; Camshafts with such cams
    • F16H53/025Single-track cams for single-revolution cycles; Camshafts with such cams characterised by their construction, e.g. assembling or manufacturing features

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
  • Gears, Cams (AREA)

Abstract

A composite camshaft 10 for an internal combustion engine comprises a supporting shaft 12 which carries a series of sintered members consisting of cams 14, journals 16, a toothed wheel 18 and a lobed rotor 20 for operating an oil pump. In order to avoid additional operations such as welding to fix the sintered members angularly on the shaft, the shaft is provided with ribs 22 and the sintered members have complementary grooves 24 in which the ribs fit. The sintered members may be fixed axially in position on the shaft 12 by being made a force fit on the shah and on the ribs 22. <IMAGE>

Description

SPECIFICATION Camshafts for internal combustion engines This invention relates to camshafts for internal combustion engines.
As is known, the primary function of such camshafts is that of actuating, by means of cams, the valves of four-stroke engines, either directly by acting on tappets or valve stems, or indirectly by means of rockers with or without push rods.
Camshafts furthermore sometimes also actuate other mechanisms of the engine, such as distributors, pumps, revolution counters and compressors and are rotated through a transmission comprising a gear train or toothed belt, by the engine crank shaft.
In many cases camshafts function also as ducting for lubricating oil which enters them at bearings which support the shafts and is then distributed through apertures in the shafts into the zones which require lubrication.
An important mechanical characteristic of such shafts is that of having good torsional and flexural strength, and optimum resistance to wear, especially at the most critical points which are the operative tips of the cams.
Traditionally, these camshafts are produced by drop-forging steel or by casting alloyed cast iron.
They are then subject to a series of machining operations, such as turning, profile turning, gear cutting, drilling and milling, and are then subjected to heat treatments and finally to finish machining.
In recent times, in view of the ease with which even complicated profiles can be obtained by the technique of sintering of metal powders and in view of the high wear resistance which such profiles offer either as a result of surface hardening treatments or owing to the high oil retention which the sintered material possesses, camshafts have appeared on the market either manufactured entirely by the sintering technique, or of a composite nature made by mixed techniques, which provide for the fitting of sintered cams of other members on to a supporting shaft of steel.In the latter case, the mechanical connection with fixes the various sintered members to the shaft, keying them in the exact positions for relative timing, is based upon welding procedures, such as electrical resistance welding, brazing with the sintered metal still green, or brazing between the shaft and the finished sintered metal.
These fixing techniques are complex and expensive and furthermore they require complicated arrangements for correctly positioning the sintered members on the shaft on the required angular positions.
The object of the present invention is to overcome the aforementioned disadvantages, and to provide a camshaft of the composite type which does not require additional operations for holding the sintered members in the correct positions relative to the supporting shaft, and may avoid delicate welding operations between the components.
To this end, according to this invention, a composite camshaft for an internal combustion engine comprises a supporting shaft and a series of sintered members, including cams and optionally journals or a toothed wheel mounted on the supporting shaft, and is characterised in that the supporting shaft has externally, at least at the zones where the sintered members are mounted, prismatic coupling means, and each sintered member has internally complementary prismatic coupling means which interengage with the coupling means on the shaft to key the sintered members angularly in position on the shaft.
The prismatic coupling means and complementary prismatic coupling means are, of course, such as to acheive the correct relative angular positions of the sintered members on the supporting shaft.
The coupling means preferably consist of ribs on the supporting shaft and corresponding grooves in the sintered members, or vice versa. When the ribs are on the shaft they may be machined by conventional procedures, for example by milling, roll forming, broaching, extrusion or drawing, and may extend axially or helically with respect to the shaft.
The axial fixing of the sintered members relative to the supporting shaft may be achieved by providing a simple force fit between the inter-engaging prismatic coupling means, or by bonding or welding at the zone encompassed by the sintered members.
An example of a camshaft in accordance with the invention will now be described with reference to the accompanying drawings in which: Figure l is a partly cut-away slightly diagrammatic perspective view of the camshaft; and Figures 2, 3 and 4 are cross-sectional views as seen in the directions of the arrows on the lines 1111, Ill-Ill and IV-IV respectively in Figure 1.
The example of the composite camshaft in accordance with this invention, referenced generally 10 in Figure 1, is composed basically of a hollow supporting shaft 12 carrying, in axially spaced apart positions, a series of members made by sintering metallic powders. These sintered members include, in this example, cams 14 for actuating the valves of the cylinders of the engine, journals 16 for the rotational support of the shaft 10, a toothed gear wheel 11 for driving the shaft 10, and a rotor with lobes 20 for actuating a lubricating oil pump of the engine.
The sintered members 14-20 are torsionally keyed on the supporting shaft 12 by simple prismatic couplings. The prismatic couplings consist, in the example illustrated, of external ribs 22 machined directly on the supporting shaft 12 by conventional mechanical procedures, and of internal grooves of complementary form 24, machined or otherwise formed in the sintered members 12 - 20.
In the example illustrated, the ribs 22 extend continuously in directions parallel to the axis of the supporting shaft 12 and are three in number spaced at equal angular intervals around the shaft, as also are the grooves 24 of the members 14 20. It should, however, be noted that the form and arrangement of the ribs 22 and of the grooves 24 may be different from that shown in the example.
In particular, the ribs 22 may be provided only in the zones where the sintered members 14-20 are fitted.
According to a further variant, which is not illus trated, the ribs 22 have a helical form rather than extending axially, to permit exact angular phase adjustment of the members 14-20 relative to the supporting shaft 12 without the necessity of inter vening in the arrangement of the grooves 24.
The axial retention of the sintered members 14 20 relative to the supporting shaft 12 may be achieved simply by providing a force-fit between the ribs 22 and the grooves 24. Alternatively, the axial connection may be achieved by adhesively bonding or by welding at the limited zones em compassed by said members.
It will be apparent from the foregoing that the construction according to this invention enables the maufacture of the camshaft to be considerably simplified, at the same time improving the struc tural strength by reason of the fact that, owing to the prismatic couplings described above, the bend ing strength and torsional strength of the camshaft as a whole is solely entrusted to the function of the supporting shaft 12.

Claims (5)

1. A composite camshaft for an internal com bustion engines, the camshaft comprising a sup porting shaft and a series of sintered members, including cams and optionally journals or a toothed wheel mounted on the supporting shaft, characterised in that the supporting shaft has ex ternally, at least at the zones where the sintered members are mounted, prismatic coupling means, and each sintered member has internally comple mentary prismatic coupling means which inter-en gage with the coupling means on the shaft to key the sintered members angularly in position on the shaft.
2. A camshaft according to Claim 1, in which the coupling means and the complementary cou pling means comprise respectively, ribs on the shaft and grooves in the sintered members.
3. A camshaft according to Claim 2, in which the ribs extend parallel to the axis of the support ing shaft.
4. A camshaft according to Claim 2, in which the the ribs extend helically with respect to the axis of the supporting shaft.
5. A camshaft according to Claim 1, substantially as described with reference to the accompanying drawings.
5. A camshaft according to any one of the pre ceding Claims, in which the sintered members are fixed axially in position on the shaft by being a force fit on the shaft and on the prismatic coupling means.
6. A camshaft according to Claim 1, substan tially as described with reference to the accompa nying drawings.
I Amendments to the claims have been filed, and have the following effect: (a) Claims 1 to 6 above have been deleted or tex tually amended.
(b) New or textually amended claims have been filed as follows:
1. A composite camshaft for an internal combustion engines, the camshaft comprising a supporting shaft and a series of sintered members, including cams and optionally journals or a toothed wheel mounted on the supporting shaft, characterised in that the supporting shaft has externally, at least at the zones where the sintered members are mounted, prismatic ribs formed integrally with, and projecting from the circular profile of, the shaft, and each sintered member as internally complementary prismatic grooves which inter-engage with the integral ribs on the shaft to key the sintered members angularly in position on the shaft.
2. A camshaft according to Claim 1, in which the ribs extend parallel to the axis of the supporting shaft.
3. A camshaft according to Claim 1, in which the ribs extend helically with respect to the axis of the supporting shaft.
4. A camshaft according to any one of the preceding Claims, in which the sintered members are fixed axially in position on the shaft by being a force fit on the shaft and on the prismatic ribs.
GB08511181A 1984-11-19 1985-05-02 Camshafts for internal combustion engines Withdrawn GB2167524A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT68156/84A IT1180140B (en) 1984-11-19 1984-11-19 COMPOSITE TIMING SHAFT FOR ENDOTHERMAL ENGINES

Publications (2)

Publication Number Publication Date
GB8511181D0 GB8511181D0 (en) 1985-06-12
GB2167524A true GB2167524A (en) 1986-05-29

Family

ID=11308228

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08511181A Withdrawn GB2167524A (en) 1984-11-19 1985-05-02 Camshafts for internal combustion engines

Country Status (4)

Country Link
DE (2) DE8517900U1 (en)
FR (1) FR2573479A1 (en)
GB (1) GB2167524A (en)
IT (1) IT1180140B (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4809562A (en) * 1987-09-30 1989-03-07 The Torrington Company Camshaft manufacture
EP0340128A1 (en) * 1988-04-28 1989-11-02 Valtubes Camshaft assembling method and camshaft obtained
USRE33888E (en) * 1986-01-17 1992-04-21 The Torrington Company Method of making a camshaft for reciprocating piston engines
US5197351A (en) * 1989-02-28 1993-03-30 Viv Engineering Inc. Cam shaft and process for manufacturing the same
EP0540977A1 (en) * 1991-11-06 1993-05-12 SMH Management Services AG Internal combustion engine with oil pump on the camshaft
USRE34565E (en) * 1986-01-17 1994-03-22 The Torrington Company Camshaft for reciprocating piston engines
DE19606732A1 (en) * 1995-02-27 1996-09-05 Emishaft Co Joined multilayer waves
GB2341220A (en) * 1998-09-04 2000-03-08 Cummins Engine Co Ltd Camshaft alignment and arrangement relative to crankshaft
EP2133516A1 (en) * 2007-04-03 2009-12-16 Toyota Jidosha Kabushiki Kaisha Internal combustion engine controller
FR3057915A1 (en) * 2016-10-20 2018-04-27 Renault S.A.S HIGH PRESSURE FUEL PUMP ARRANGEMENT ACTUATED BY CRANKSHAFT FACE SIDE FITTING

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2747537B2 (en) 1988-11-21 1998-05-06 クルップ プレスタ アーゲー Camshaft
US5107805A (en) * 1991-07-18 1992-04-28 Borg-Warner Automotive Transmission & Engine Components Corporation Camshaft with extra cam to increase the magnitude of torque pulsations therein
DE10220838C1 (en) * 2002-05-08 2003-12-18 Porsche Ag Internal combustion engine
DE202013007575U1 (en) * 2013-08-26 2014-11-28 GM Global Technology Operations LLC (n. d. Ges. d. Staates Delaware) Camshaft for an internal combustion engine, internal combustion engine and motor vehicle with an internal combustion engine

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1115093A (en) * 1965-12-30 1968-05-22 G K N Screws And Fasteners Ltd Improvements in or relating to cam shafts
GB1117816A (en) * 1965-07-31 1968-06-26 Gkn Screws Fasteners Ltd Improvements relating to cam shafts
GB1131379A (en) * 1966-09-13 1968-10-23 Motosacoche Sa Improvements in or relating to a cam shaft
GB1499946A (en) * 1975-04-21 1978-02-01 Dresser Ind Crankshaft construction

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE7330201U (en) * 1974-08-14 Engels A Gmbh Camshaft for the valve control of internal combustion engines
DE368775C (en) * 1923-02-09 Samuel Haltenberger Automatic altitude control device for aircraft engines
FR552028A (en) * 1921-09-30 1923-04-19 Aeroplanes Voisin Sa Timing drive shaft for four-stroke combustion engines
DE2336241A1 (en) * 1973-07-17 1975-02-06 Volkswagenwerk Ag Compound camshaft assembly for combustion engine - consists of shaft carrying separate bearings cams gearwheels etc fixed in correct positions
FR2503250B1 (en) * 1981-04-03 1987-07-24 Kubota Ltd MOTOR CAMSHAFT
FR2541720B1 (en) * 1983-02-24 1987-05-22 Citroen Sa GLUE SINTERED CAMSHAFT

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1117816A (en) * 1965-07-31 1968-06-26 Gkn Screws Fasteners Ltd Improvements relating to cam shafts
GB1115093A (en) * 1965-12-30 1968-05-22 G K N Screws And Fasteners Ltd Improvements in or relating to cam shafts
GB1131379A (en) * 1966-09-13 1968-10-23 Motosacoche Sa Improvements in or relating to a cam shaft
GB1499946A (en) * 1975-04-21 1978-02-01 Dresser Ind Crankshaft construction

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE34565E (en) * 1986-01-17 1994-03-22 The Torrington Company Camshaft for reciprocating piston engines
USRE33888E (en) * 1986-01-17 1992-04-21 The Torrington Company Method of making a camshaft for reciprocating piston engines
US4809562A (en) * 1987-09-30 1989-03-07 The Torrington Company Camshaft manufacture
FR2630790A1 (en) * 1988-04-28 1989-11-03 Valtubes METHOD FOR ASSEMBLING A REPORTED CAM SHAFT AND CAM TREE SO OBTAINED
EP0340128A1 (en) * 1988-04-28 1989-11-02 Valtubes Camshaft assembling method and camshaft obtained
US5197351A (en) * 1989-02-28 1993-03-30 Viv Engineering Inc. Cam shaft and process for manufacturing the same
EP0540977A1 (en) * 1991-11-06 1993-05-12 SMH Management Services AG Internal combustion engine with oil pump on the camshaft
DE19606732C2 (en) * 1995-02-27 2001-11-08 Emitec Emissionstechnologie Joined multilayer waves
US6192582B1 (en) 1995-02-27 2001-02-27 Emitec Gesellschaft Für Emissionstechnologie Mbh Assembled multi-layer shafts
DE19606732A1 (en) * 1995-02-27 1996-09-05 Emishaft Co Joined multilayer waves
GB2341220A (en) * 1998-09-04 2000-03-08 Cummins Engine Co Ltd Camshaft alignment and arrangement relative to crankshaft
EP2133516A1 (en) * 2007-04-03 2009-12-16 Toyota Jidosha Kabushiki Kaisha Internal combustion engine controller
EP2133516A4 (en) * 2007-04-03 2012-02-01 Toyota Motor Co Ltd Internal combustion engine controller
US8166935B2 (en) 2007-04-03 2012-05-01 Toyota Jidosha Kabushiki Kaisha Control system of internal combustion engine
FR3057915A1 (en) * 2016-10-20 2018-04-27 Renault S.A.S HIGH PRESSURE FUEL PUMP ARRANGEMENT ACTUATED BY CRANKSHAFT FACE SIDE FITTING

Also Published As

Publication number Publication date
GB8511181D0 (en) 1985-06-12
FR2573479A1 (en) 1986-05-23
DE8517900U1 (en) 1988-07-07
IT8468156A1 (en) 1986-05-19
IT1180140B (en) 1987-09-23
IT8468156A0 (en) 1984-11-19
DE3522020A1 (en) 1986-05-28

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Legal Events

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)