Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C7/00—Connecting-rods or like links pivoted at both ends; Construction of connecting-rod heads
  • F16C7/02—Constructions of connecting-rods with constant length
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C7/00—Connecting-rods or like links pivoted at both ends; Construction of connecting-rod heads
  • F16C7/02—Constructions of connecting-rods with constant length
  • F16C7/026—Constructions of connecting-rods with constant length made of fibre reinforced resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2206/00—Indexing codes related to the manufacturing of suspensions: constructional features, the materials used, procedures or tools
  • B60G2206/01—Constructional features of suspension elements, e.g. arms, dampers, springs
  • B60G2206/10—Constructional features of arms
  • B60G2206/11—Constructional features of arms the arm being a radius or track or torque or steering rod or stabiliser end link
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2206/00—Indexing codes related to the manufacturing of suspensions: constructional features, the materials used, procedures or tools
  • B60G2206/01—Constructional features of suspension elements, e.g. arms, dampers, springs
  • B60G2206/70—Materials used in suspensions
  • B60G2206/71—Light weight materials
  • B60G2206/7101—Fiber-reinforced plastics [FRP]

Definitions

• the present invention relates to connecting rods particularly of the type used for connecting pistons to crank shafts in machines such as internal combustion engines.
• FRP connecting rods having the requisite strength and a much reduced weight.
• FRP connecting rods having the requisite strength and a much reduced weight.
• One of the problems which arise in the successful construction of a FRP connecting rod is the attachment of the connecting rod to the piston and the crank shaft.
• the end of the connecting rod connected to the piston is commonly known as the little end, whilst that connected to the crank shaft is commonly known as the big end. It is the big end connection which poses the most problems.
• Connecting rods are conventionally split at the big end along a diagonal of a hole which is designed to surround the crank shaft, the diagonal being at right angles to the axis of the connecting rod.
• Connection of the main body of the connecting rod to a detachable cap is usually effected by means of nuts and bolts.
• the design of a FRP connecting rod it is usual to have fibres in the FRP material aligned substantially longitudinally to the connecting rod axis as the main stresses therein are tension and, particularly, in compression.
• the holes drilled at the big end of the connecting rod to allow passage of a bolt lie substantially parallel to the adjacent fibres.
• the nut and bolt combination results in a shear effect, and FRP materials have low strength to shear forces parallel tothe alignment of the fibres therein.
• the present invention provides a novel form of FRP connecting rod.
• a connecting rod includes a backbone formed from continuous fibred Fibre Reinforced Plastic, at least a substantial proportion of the continuous fiores being unidirectionally aligned along the length of the backbone, and at least one of a big and little end formed from short-fibred Fibre Reinforced Plastic, the short fibres having random alignment, the material of the end being bonded to the material of the backbone.
• the backbone will usually be so shaped as to provide a degree of stiffness against bending and twisting, and a preferred embodiment has a backbone consisting of 2 channel sections bonded together along the bases of the channels.
• the materials of the end and of the backbone are preferably bonded together by an injection moulding process.
• the bonding together of two channel sections to form the backbone, and of the backbone to the end, may be performed in one process.
• 2 identical channel sections are formed from continuous fibred FRP by sandwiching a sheet of FRP between 2 thin metal sheets, the FRP sheet being aligned such that a substantial proportion of th fibres will lie along the length of the channels, the sandwich being then heated to an appropriate temperature and forced against a first mould by air pressure, the channels then being bonded together at the base of the channel sections, the resultant backbone being positioned relative to a second mould defining the shape of a big end, short fibred FRP material then being injected into the end mould such that the material bonds to the material of the backbone.
• Both ends of the backbone may be treated, at the same time with the backbone being positioned in a mould defining the final shape of the rod, and injecting short fibred FRP at both big and little ends.
• the FRP materials are preferably thermoplastic materials and might be, for example, polytheretherketone (PEEK).
• PEEK polytheretherketone
• a suitable material is Fiberite (RTM) APC2 manufactured by the Fiberite Company, and a suitable short fibred material is Victrex (RTM) manufactured by ICI pic, which is available with varying percentages and types of fibre reinforcement.
• Figure 1 is an elevation of a connecting rod
• Figure 2 is an end elevation, in section along line II-I of Figure 1, of the connecting rod
• Figure 3 is a plan view, in section along line III-III of Figure 1,
• FIG 4 is a perspective view of an apparatus for making a backbone member for the connecting rod illustrated in Figures 1 to 3.
• Figure 5 is a plan view of a backbone member
• Figure 6 is an end view of a backbone member
• Figure 7 is a perspective view of an apparatus for bonding a piston end member to the backbone member.
• a connecting rod ( Figures 1 to 3 ) 10 has a backbone 11 formed from 2 channel members 12, 13 each formed from continuous fibred FRP material, the continuous fibres being substantially unidirectionally aligned with a centre line 14 of the connecting rod.
• Each channel member 12, 13 (see Figure 3) has a base 15, sides 16, and flanges 17.
• the flange members 17 are extended as illustrated in Figure 1 at 18 in the vicinity of a first end of the backbone 11.
• a big end portion 20 formed from short fibre FRP is bonded to the end 19 of the backbone 11, the bonding extending over the extensions 18 of the flanges 17.
• a semi circular channel 21 is symmetrically positioned with reference to the centre line 14 at the first end 19 of the backbone 11.
• the big end portion 20 is connected to a cap portion 22, which defines a semi circular channel 23 complementary with the semi circular channel
• a second end 30 of the backbone 11 which has extensions 31 of the flanges 17 has a little end portion of short fibre FRP, 32, bonded thereto.
• the little end portion 32 and backbone 11 have a hole 33 there through, the centre line of the hole 33 passing through the axis 14 of the backbone 11.
• FIG. 1 to 3 can be produced ( Figures 4 to 7) by sandwiching a sheet of continuous fibred FRP 40 between 2 thin sheets 41 of a metal such as aluminium and forcing the sheet by, for example, air pressure (as illustrated at 42) into a channel 43 in a die 44.
• the alignment of the fibres in the sheet 40 should be such that they lie substantially longitudinally along an axis of a channel member ( Figures 5, 6) that is formed.
• the channel has a base 15, sides 16 and flanges 17.
• Extensions 18, 31 are formed on the flanges 17, either by machining oversized flanges, or by shaping of the sheet 40.
• a backbone 11 is formed ( Figure 6) by bonding the bases 15 of 2 identical cnannels together.
• An end member 20, or end 32 is attached at an end 19 or 30 by positioning the end within a mould box 50 ( Figure 7) having a mould to form the appropriate end shape, and injecting short fibre FRP through an aperture 51. By keeping the mould a"tthe appropriate temperature the materials of the backbone 11 and end members will be bonded together.
• the connecting rod may be formed in one operation by positioning the channel members in a mould defining the shape of the final rod, and simultaneously bonding bases 15 of the channel members together and injecting short fibre FRP into big 20 and little 32 end mould boxes similar to box 50.
• a connecting rod according to the invention,in which the backbone was formed from Fib-exite (RTM) APC2 and the end members from Victorex (RTM) having a 30% carbon fibre reinforcement was constructed and tested.
• the end members for the test specimen were assembled by machining material from block end members to fill the channels in a backbone such as that illustrated in Figures 5 and 6, and the two were then bonded together by heating and the application of pressure.
• the connecting rod was used in an engine running at various speeds ranging from 1,500 to 3,000 rpm at minimum load, and survived 3 x 10" cycles without any signs of fatigue cracking,even about the bolt holes or neck regions of the assembly.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
• Reinforcement Elements For Buildings (AREA)
• Moulding By Coating Moulds (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10625550

Family Applications (1)

Country Status (10)

Cited By (1)

Families Citing this family (4)

Family Cites Families (8)

• 1987
  • 1987-10-19 GB GB878724466A patent/GB8724466D0/en active Pending
• 1988
  • 1988-10-18 PT PT88790A patent/PT88790B/pt not_active IP Right Cessation
  • 1988-10-18 ES ES888803158A patent/ES2011156A6/es not_active Expired
  • 1988-10-19 BR BR888807756A patent/BR8807756A/pt not_active IP Right Cessation
  • 1988-10-19 KR KR1019890701097A patent/KR890701910A/ko not_active Withdrawn
  • 1988-10-19 JP JP63508434A patent/JPH03500802A/ja active Pending
  • 1988-10-19 EP EP88909214A patent/EP0444020A1/en not_active Withdrawn
  • 1988-10-19 WO PCT/GB1988/000881 patent/WO1989003940A1/en not_active Ceased
  • 1988-10-19 AU AU25521/88A patent/AU611968B2/en not_active Ceased
• 1990
  • 1990-04-06 DK DK086690A patent/DK86690A/da not_active Application Discontinuation
  • 1990-04-11 GB GB9008305A patent/GB2229792B/en not_active Expired - Lifetime

Non-Patent Citations (1)

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