GB2121908A - A camshaft - Google Patents

A camshaft Download PDF

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Publication number
GB2121908A
GB2121908A GB8316359A GB8316359A GB2121908A GB 2121908 A GB2121908 A GB 2121908A GB 8316359 A GB8316359 A GB 8316359A GB 8316359 A GB8316359 A GB 8316359A GB 2121908 A GB2121908 A GB 2121908A
Authority
GB
United Kingdom
Prior art keywords
cam
shaft
camshaft
cams
projection
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.)
Granted
Application number
GB8316359A
Other versions
GB8316359D0 (en
GB2121908B (en
Inventor
Shigeru Urano
Michiyoshi Matsuzaki
Shunsuke Takeguchi
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.)
Nippon Piston Ring Co Ltd
Original Assignee
Nippon Piston Ring Co Ltd
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 Nippon Piston Ring Co Ltd filed Critical Nippon Piston Ring Co Ltd
Publication of GB8316359D0 publication Critical patent/GB8316359D0/en
Publication of GB2121908A publication Critical patent/GB2121908A/en
Application granted granted Critical
Publication of GB2121908B publication Critical patent/GB2121908B/en
Expired legal-status Critical Current

Links

Classifications

    • 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
    • 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
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00Supplementary information concerning processes or compositions relating to powder metallurgy

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Gears, Cams (AREA)

Abstract

A composite camshaft for use in an internal combustion engine comprises a tubular steel shaft 1 and a plurality of cams 31-38 mounted on the shaft. The shaft has a plurality of circumferentially spaced longitudinally extending grooves or projections 11-14 which in number are equal to or less than the engine cylinders. Every cam is identically shaped to have at least one projection or groove 30 in its inner periphery for co- operation with one of the grooves or projections of the shaft. The projection or groove 30 is angularly spaced by a preselected angle ??? from a symmetrical centre-line of the cam, passing through the cam nose, the preselected angle being one half of an angle ??? defined between the case noses of a pair of inlet and exhaust cams. <IMAGE>

Description

SPECIFICATION A camshaft The invention relates to a camshaft for operating inlet and exhaust valves in an internal combustion engine.
Camshafts for use in an internal combustion engine are required to have wear-resistant cams as well as a rigid and fatigue-resistant shafts.
Moreover, it has recently become desirable for camshafts to be light in weight in order to save on fuel. In general, one piece camshafts of chilled iron or hardened alloy cast iron are superior in wearresistance. However, the camshaft of cast iron becomes disadvantageous with length, because it cannot be lengthened without increasing warpage by casting and thickness to have a desired strength.
A composition camshaft has been disclosed in Published Japanese Utility Model Application No.
51-7367 and Published Unexamined Japanese Patent Application No. 54-41266 which has a tubular shaft of steel pipe and cams made of oilimpregnated sintered alloy. The cams are positioned on the shaft by means of grooveprojection connections. The disclosed camshaft has a shaft formed with grooves equal in number to the cams which are double in number of the engine cylinders, because every cylinder has a pair of different crank angles for actuation of its inlet and exhaust valves. However, providing so many grooves on the shaft leads to disadvantages one of which is that the shaft needs many expensive machining bperations. Another disadvantage is that the shaft cannot compensate for reduction in strength due to many grooves without increasing weight and thickness.
In contrast, if the number of grooves in the shaft is reduced to less than the number of cams, the cams increase in kind because of the need to have the projections formed at two or more different positions in accordance with the reduced number of grooves. Each kind of cam of sintered alloy or cast-steel requires a different kind of mould. This leads to disadvantages one of which is that the cams become costly. Another disadvantage is that there is a greater risk that the cams will be incorrectly assembled on the shaft.
According to the invention there is provided a camshaft for use in an internal combustion engine with a plurality of cylinders, comprising a tubular steel shaft and a plurality of cams mounted on the shaft, the shaft having a plurality of grooves or projections for co-operation with at least one groove or projection provided in the inner periphery of each cam, the groove or projection in the inner periphery of the cam being spaced by a preselected angle from a symmetrical line of the cam passing through a cam nose, said preselected angle being one-half of an angle defined between the respective cam noses of a pair of inlet and exhaust cams.
Preferred and/or optional features of the invention are set fourth in claims 2-6.
The invention will now be more particularly described with reference to the accompanying drawings, in which: Figure 1 is a longitudinal section of one embodiment of a camshaft according to the invention; Figure 2 is a perspective view of the relevant portion of the camshaft of Figure 1; Figure 3 is a front elevation of a cam of Figure 1; Figure 4 is a section taken along the line IV--IV of Figure 1 but somewhat rotated; Figure 5 is a view, similar to Figure 2, of another embodiment of the invention; and Figure 6 is a front elevation of a cam of another embodiment.
Referring firstly to Figure 1 the camshaft shown therein has a tubular shaft 1 of steel pipe provided with longitudinally extending circumferentially spaced grooves 11, 12, 13 and 14. The camshaft also has inlet cams 31, 33, 35, 37, exhaust cams 32, 34, 36, 38, journals 4, a gear 5, a driving side end part 21, and a free end part 22 all of which are individually mounted on the shaft 1. Each cam has a projection 30 formed in its inner periphery for fitting engagement with one of the longitudinally extending grooves 11-13. The cams are generally made of sintered alloy which is readily mouldable, appropriately lubricative, and metallurgically wear-resistant.Particularly, the cams are made of liquid phase sintered alloy to obtain high compression strength and metallurgical bonding with the shaft when the assembly of the cams and the shaft is sintered as one-piece at a temperature causing a diffusion of liquid phase. The journals 4, the gear 5, and the end parts 21,22 are not required to be highly wear-resistant and therefore may be made of steel, plastic resin, cast-iron, or sintered alloy.
As seen in Figure 2, the longitudinally extending grooves 11, 12, 1 3, 14 formed in the shaft 1 are equal in number to the number of cylinders of a non-illustrated four cylinder engine to position each cam at a predetermined position.
Each cam has, as previously mentioned, a projection 30 formed on its inner periphery 39 for fitting engagement with one of the four grooves 11,12, 13, and 14. Cams 32 forthe first cylinder are angularly positioned by groove 11 in which the respective projections 30 are located and cams 33, 34 for the second cylinder are positioned by groove 1 2 in which the respective projections 30 are located. The other cams for the third and fourth cylinders are positioned by grooves 13, 14. The journal 4 is metallurgically secured to the stem 1.
As seen in Figure 3, the projection 30 is angularly spaced by an angle /3 from a symmetrical line A-A passing through the top of the cam nose 300 of the cam 3.
As seen in Figure 4, the inlet and exhaust cams 31,32 have their cam noses located on opposite sides of a plane passing through the respective projections 30. The symmetrical lines of the inlet and exhaust cams 31, 32 define therebetween an angle of a and intersect the aforesaid plane with the same angle of p on opposite sides. The inlet and exhaust cams 31, 32 are identical in shape but reversed with respect to each other in order that their projections 30 can be fitted in a common groove in the shaft. The result of this is that the number of grooves is one half of the number of cams or equal to the number of the cylinders. The angle A js one half of an angle of a defined between the respective cam noses of inlet and exhaust cams 31 and 32 of the same cylinder.
In the case of cams of sintered alloy, the alloy powder can be moulded in the same kind of mould and shaped into a kind of cam, which is available both as an inlet valve cam and as an exhaust valve cam when reversed.
The shaft of the camshaft requires only one half of the number of grooves of the known arrangement. One advantage of this is that expensive machining operations are significantly decreased. Another advantage is that the shaft strength is reduced less due to the grooves.
In the embodiment of Figure 5, the tubular shaft 1 has projections 10 in place of the grooves of the previous embodiment, while the cams 3 are each formed with a groove 30 for fitting engagement with the'projection. The shaft can be thinned without losing its strength because of having no groove. The cams and the shaft are easily and correctly assembled by making a notched mark 1 7 indicating the individual cylinder on the projection 10 and another mark 301 on the side of the cam prior to assembling. The inlet and exhaust cams 31 and 32 are easily paired when their same marks 301 oppose each other and their angular and axial positions on the shaft can be confirmed by the mark 17.
The projection or groove of each cam can be formed not only on the side of the cam nose 300, i.e. at a position angularly spaced from the cam nose by an acute angle, as seen in Figure 3 but also on the side opposite to the cam nose 300, i.e.
at a position angularly spaced from the cam nose by an obtuse angle, as seen in Figure 6, in which the cam 3 has its projection 30 located at a position spaced by an angle of p from the symmetrical line A-A passing through the cam nose 300 on the side opposite to the cam nose.
The cam may have two projections on the same and opposite sides of cam nose, if the side is marked.
Cams of steel can have as many projections as the number of cylinders. For example, it can have four projections in the case of an engine with four cylinders each having a phase difference of 90 degrees. However, in the case of cams of sintered alloy, it is desirable to have only a single projection, because of the difficulty otherwise in producing the necessary mold. The projection is rather shaped in the form of an arc than a triangle.
The projection on or grooves in the shaft are equal in number to the cylinders. However, two or more cylinders with the same phase should be counted as one cylinder. For example, eight cylinders are counted as four cylinders if every two cylinders are of the same phase, resulting in that the shaft is formed with four projections or grooves. This means that a camshaft embodying the invention becomes more advantageous with the number of engine cylinders.
While only certain embodiments of the invention have been illustrated and described, it is apparent that alterations, modifications and changes may be made without departing from the scope thereof as defined by the appended claims.

Claims (7)

1. A camshaft for use in an internal combustion engine with a plurality of cylinders, comprising a tubular steel shaft and a plurality of cams mounted on the shaft, the shaft having a plurality of grooves or projections for co-operation with at least one groove or projection provided in the inner periphery of each cam, the groove or projection in the inner periphery of the cam being spaced by a preselected angle from a symmetrical line of the cam passing through a cam nose, said preselected angle being one-half of an angle defined between the respective cam noses of a pair of inlet and exhaust cams.
2. A camshaft as claimed in claim 1, wherein the number of said grooves or projections in said shaft is at most equal to the number of cylinders of the engine in which the camshaft is designed to operate.
3. A camshaft as claimed in claim 1 or claim 2, wherein each cam is of sintered alloy.
4. A camshaft as claimed in any one of claims 1-3, wherein the groove or projection in the inner periphery of said cam is spaced from the nose of the cam by an acute angie.
5. A camshaft as claimed in any one of claims 1-4, wherein the shaft is provided with grooves and each is provided with at least one projection.
6. A camshaft as claimed in any one of claims 4, wherein the shaft is provided with projections and each cam is provided with at least one groove.
7. A camshaft for use in an internal combustion engine, substantially as hereinbefore described with reference to any one of the embodiments shown in the accompanying drawings.
GB8316359A 1982-06-17 1983-06-16 A camshaft Expired GB2121908B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8957582U JPS58191305U (en) 1982-06-17 1982-06-17 camshaft

Publications (3)

Publication Number Publication Date
GB8316359D0 GB8316359D0 (en) 1983-07-20
GB2121908A true GB2121908A (en) 1984-01-04
GB2121908B GB2121908B (en) 1985-09-18

Family

ID=13974596

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8316359A Expired GB2121908B (en) 1982-06-17 1983-06-16 A camshaft

Country Status (3)

Country Link
JP (1) JPS58191305U (en)
DE (1) DE3321846A1 (en)
GB (1) GB2121908B (en)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0153409A1 (en) * 1983-08-03 1985-09-04 NIPPON PISTON RING CO., Ltd. Cam shaft and method of manufacturing thereof
GB2172088A (en) * 1985-03-06 1986-09-10 Fischer Ag Georg Compound camshaft
FR2593228A1 (en) * 1986-01-17 1987-07-24 Torrington Co CAMSHAFT FOR ALTERNATIVE PISTON MOTORS AND METHOD FOR MANUFACTURING THE SAME
US4774852A (en) * 1986-02-26 1988-10-04 Etablissement Supervis Campshaft for actuating valve tappets in internal combustion engines
WO1989002997A1 (en) * 1987-10-01 1989-04-06 Husted Royce Hill Camshafts and methods of making same
FR2644543A1 (en) * 1989-03-17 1990-09-21 Renault
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
US5287615A (en) * 1987-12-15 1994-02-22 Emitech Gesellschaft Fur Emissionstechnologie Mbh Process for joining a hollow shaft and elements slid thereon
USRE34565E (en) * 1986-01-17 1994-03-22 The Torrington Company Camshaft for reciprocating piston engines
GB2271827A (en) * 1992-10-26 1994-04-27 Pitney Bowes Inc Mounting a bearing race on a shaft
GB2277361A (en) * 1993-04-21 1994-10-26 T & N Technology Ltd Manufacture of camshafts
WO1996027077A1 (en) * 1995-02-27 1996-09-06 Emitec Gesellschaft Für Emissionstechnologie Mbh Assembled multi-layer shafts
US5992017A (en) * 1994-12-20 1999-11-30 Grafchev; Alexei Petrovich Method and tool for the manufacture of a built-up camshaft
GB2341220A (en) * 1998-09-04 2000-03-08 Cummins Engine Co Ltd Camshaft alignment and arrangement relative to crankshaft
US6189194B1 (en) * 1996-06-26 2001-02-20 Daimlerchrysler Ag Method for joining and inspecting
GB2467334A (en) * 2009-01-30 2010-08-04 Mechadyne Plc Assembled camshaft for i.c. engines
WO2016037790A1 (en) * 2014-09-10 2016-03-17 Delphi International Operations Luxembourg S.À R.L. Driveshaft assembly
CN106246724A (en) * 2016-08-24 2016-12-21 常州市群星印刷有限公司 The printing machine's bearing that inner ring is fixed
US9683464B2 (en) 2012-08-16 2017-06-20 Amtek Tekfor Holding Gmbh Method for producing a camshaft module and corresponding camshaft module

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60209607A (en) * 1984-03-31 1985-10-22 Mitsubishi Metal Corp Structure of cam shaft in internal-combustion engine
JPS61290271A (en) * 1985-06-18 1986-12-20 Nippon Piston Ring Co Ltd Hollow cam shaft
DE3536296C1 (en) * 1985-10-11 1987-03-26 Supervis Ets camshaft
DE3717190A1 (en) * 1987-05-22 1988-12-15 Supervis Ets CAMSHAFT FOR CONTROLLING VALVES IN COMBUSTION ENGINES AND METHOD FOR THEIR PRODUCTION
DE4008906A1 (en) * 1990-03-20 1991-09-26 Gkn Automotive Ag Hollow IC engine camshaft - has drive tube with inner opening incorporating wedges with inner space
DE19520306C2 (en) * 1995-06-02 1998-05-20 Ford Werke Ag Composite camshaft, in particular for internal combustion engines
DE19710847C2 (en) * 1997-03-15 1999-01-07 Selzer Fertigungstech Composite control shaft and process for its manufacture
DE19829830A1 (en) * 1998-07-03 2000-01-05 Volkswagen Ag Shaft arrangement
DE102009055327A1 (en) * 2009-12-28 2011-06-30 Robert Bosch GmbH, 70469 Piston pump with eccentric ring
DE102012008219B4 (en) * 2012-04-25 2019-05-16 Audi Ag Valve gear of an internal combustion engine

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5854901B2 (en) * 1977-09-08 1983-12-07 トヨタ自動車株式会社 Camshaft manufacturing method and device

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0153409A1 (en) * 1983-08-03 1985-09-04 NIPPON PISTON RING CO., Ltd. Cam shaft and method of manufacturing thereof
EP0153409A4 (en) * 1983-08-03 1986-02-20 Nippon Piston Ring Co Ltd Cam shaft and method of manufacturing thereof.
GB2172088A (en) * 1985-03-06 1986-09-10 Fischer Ag Georg Compound camshaft
FR2593228A1 (en) * 1986-01-17 1987-07-24 Torrington Co CAMSHAFT FOR ALTERNATIVE PISTON MOTORS AND METHOD FOR MANUFACTURING THE SAME
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
US4774852A (en) * 1986-02-26 1988-10-04 Etablissement Supervis Campshaft for actuating valve tappets in internal combustion engines
WO1989002997A1 (en) * 1987-10-01 1989-04-06 Husted Royce Hill Camshafts and methods of making same
US5287615A (en) * 1987-12-15 1994-02-22 Emitech Gesellschaft Fur Emissionstechnologie Mbh Process for joining a hollow shaft and elements slid thereon
US5197351A (en) * 1989-02-28 1993-03-30 Viv Engineering Inc. Cam shaft and process for manufacturing the same
EP0397540A1 (en) * 1989-03-17 1990-11-14 Regie Nationale Des Usines Renault Camshaft for engine with variable valve timing
FR2644543A1 (en) * 1989-03-17 1990-09-21 Renault
GB2271827A (en) * 1992-10-26 1994-04-27 Pitney Bowes Inc Mounting a bearing race on a shaft
US5392511A (en) * 1993-04-21 1995-02-28 T & N Technology Limited Manufacture of camshafts
GB2277361A (en) * 1993-04-21 1994-10-26 T & N Technology Ltd Manufacture of camshafts
GB2277361B (en) * 1993-04-21 1995-11-08 T & N Technology Ltd Manufacture of camshafts
US5992017A (en) * 1994-12-20 1999-11-30 Grafchev; Alexei Petrovich Method and tool for the manufacture of a built-up camshaft
WO1996027077A1 (en) * 1995-02-27 1996-09-06 Emitec Gesellschaft Für Emissionstechnologie Mbh Assembled multi-layer shafts
US5979386A (en) * 1995-02-27 1999-11-09 Emitech Gesellschaft Fur Emissionstechnologie Mbh Assembled multi-layer shafts
US6192582B1 (en) 1995-02-27 2001-02-27 Emitec Gesellschaft Für Emissionstechnologie Mbh Assembled multi-layer shafts
US6189194B1 (en) * 1996-06-26 2001-02-20 Daimlerchrysler Ag Method for joining and inspecting
GB2341220A (en) * 1998-09-04 2000-03-08 Cummins Engine Co Ltd Camshaft alignment and arrangement relative to crankshaft
GB2467334A (en) * 2009-01-30 2010-08-04 Mechadyne Plc Assembled camshaft for i.c. engines
US9683464B2 (en) 2012-08-16 2017-06-20 Amtek Tekfor Holding Gmbh Method for producing a camshaft module and corresponding camshaft module
WO2016037790A1 (en) * 2014-09-10 2016-03-17 Delphi International Operations Luxembourg S.À R.L. Driveshaft assembly
EP3006722A1 (en) * 2014-09-10 2016-04-13 Delphi International Operations Luxembourg S.à r.l. Driveshaft assembly
US10557448B2 (en) 2014-09-10 2020-02-11 Delphi Technologies Ip Limited Driveshaft assembly with indexing means
CN106246724A (en) * 2016-08-24 2016-12-21 常州市群星印刷有限公司 The printing machine's bearing that inner ring is fixed

Also Published As

Publication number Publication date
GB8316359D0 (en) 1983-07-20
JPS58191305U (en) 1983-12-19
DE3321846C2 (en) 1990-07-05
GB2121908B (en) 1985-09-18
DE3321846A1 (en) 1983-12-22

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Legal Events

Date Code Title Description
PE20 Patent expired after termination of 20 years