CA1282350C - Composite tubular elements and methods of fabrication - Google Patents
Composite tubular elements and methods of fabricationInfo
- Publication number
- CA1282350C CA1282350C CA000533849A CA533849A CA1282350C CA 1282350 C CA1282350 C CA 1282350C CA 000533849 A CA000533849 A CA 000533849A CA 533849 A CA533849 A CA 533849A CA 1282350 C CA1282350 C CA 1282350C
- Authority
- CA
- Canada
- Prior art keywords
- tube
- layer
- reinforcing
- tubular element
- sleeve
- 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
Links
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
- F16C3/00—Shafts; Axles; Cranks; Eccentrics
- F16C3/02—Shafts; Axles
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- 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
- F16C3/00—Shafts; Axles; Cranks; Eccentrics
- F16C3/02—Shafts; Axles
- F16C3/023—Shafts; Axles made of several parts, e.g. by welding
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- 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
- F16C3/00—Shafts; Axles; Cranks; Eccentrics
- F16C3/02—Shafts; Axles
- F16C3/026—Shafts made of fibre reinforced resin
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Ocean & Marine Engineering (AREA)
- Mechanical Engineering (AREA)
- Laminated Bodies (AREA)
- Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
- Moulding By Coating Moulds (AREA)
- Manufacture Of Alloys Or Alloy Compounds (AREA)
Abstract
ABSTRACT
The present invention relates to a unique fiber-reinforced metallic tubular element, along with a unique method for producing such tubular elements on a production basis. The tubular element includes a cylindrical aluminum tube surrounded by a fiber composite sleeve which includes a plurality of individual reinforcing graphite fibers oriented parallel to the longitudinal axis of the tube and uniformly positioned about the circumference of the tube. In the preferred embodiment of the invention, an isolation layer is positioned between the graphite reinforcing layer and the outer surface of the aluminum tube, and a protective covering layer of fiber material surrounds the tube and is adhered to the outer surface of the graphite reinforcing layer. In the preferred method of the present invention, a plurality of cylindrical metal tubes are coupled to one another in an end-to-end relationship by a plurality of joining plug members to form a longitudinally extending series of metal tubes. The series of metal tubes are fed along a longitudinal axis to an apparatus for applying the individual layers of the composite fiber sleeve along with a curable resin material to the tube. As the series of tubes having the cured composite sleeve thereon exits the apparatus, the tubes are severed at each of the joining plugs to produce a plurality of individual fiber reinforced tubular elements. Alternate methods of manufacturing the fiber reinforced tubular elements are also disclosed. In the preferred embodiment of the invention, the fiber reinforced tubular element is utilized as a vehicle drive shaft.
The present invention relates to a unique fiber-reinforced metallic tubular element, along with a unique method for producing such tubular elements on a production basis. The tubular element includes a cylindrical aluminum tube surrounded by a fiber composite sleeve which includes a plurality of individual reinforcing graphite fibers oriented parallel to the longitudinal axis of the tube and uniformly positioned about the circumference of the tube. In the preferred embodiment of the invention, an isolation layer is positioned between the graphite reinforcing layer and the outer surface of the aluminum tube, and a protective covering layer of fiber material surrounds the tube and is adhered to the outer surface of the graphite reinforcing layer. In the preferred method of the present invention, a plurality of cylindrical metal tubes are coupled to one another in an end-to-end relationship by a plurality of joining plug members to form a longitudinally extending series of metal tubes. The series of metal tubes are fed along a longitudinal axis to an apparatus for applying the individual layers of the composite fiber sleeve along with a curable resin material to the tube. As the series of tubes having the cured composite sleeve thereon exits the apparatus, the tubes are severed at each of the joining plugs to produce a plurality of individual fiber reinforced tubular elements. Alternate methods of manufacturing the fiber reinforced tubular elements are also disclosed. In the preferred embodiment of the invention, the fiber reinforced tubular element is utilized as a vehicle drive shaft.
Description
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TITLE
CO~POSITE TUBULAR ELEMENTS AND METHODS OF FABRICATION
BACKGROUND OF THE INVENTION
The present in~ention relates generally to fiber reinforced tubular elements such as vehicle drive shafts and, in particular, to a graphite reinforced luminum drive shaft and a method for producing such a drive shaft.
Over the past decade, there has been an ongoing endeavor by the industry to reduce the weight of vehicles in order to improve fuel economy. In addition to downsizing and redesigning vehicles to make the most efficient use of $he available space, a great deal of attention has been given to constructing various vehicular components of lighter weight materials. For example, in the area of drive shafts, it has been proposed to replace conventional steel drive shafts with lighter weight aluminum tubes. However, depending on the length of the drive shaft, and the maximum speed at which the drive shaft is to be rotated, vibration problems can arise.
While typically the tubular steel or aluminum drive shafts are adequate to transmit the torsional forces involved, there is a tendency for a shaft to "whip" or resonate mechanically when ~he shaft reaches a certain vehicle speed, typicalIy referred to as a critical speed.
Consequently, in order to overcome the critical speed limitations of single long drive shafts, typically multiple sections of shafts are employed. In these instances, adjacent individual drive shaft sections are connected to one another by means of a universal joint assembly which in turn is supported by a bearing mounting unit affixed to the vehicle frame.
In order to accommodate a longer drive shaft such that the universal joint assemblies and the bearing mounting units can be eliminated, it has been proposed to reinforce metal tubes with a fiber reinforced sleeve portion to ~ ~ ~X 3 ~
increase the axial stiffness of the shaft without substantially increasing its weight. For example, United States Patent Nos. 4,131,701; 4,173,670; and 4,214,932 all disclose fiber composite aluminum drive shafts wherein aluminum tubes are wrapped with alternating layers of resin-impregnated woven fiberglass cloth and resin-impregnated fiber reinforcing sheets. The reinforcing sheets are comprised of continuous unindirectional graphite ~iber layers, with the graphite fibers arranged at angles between +5 to +20 with respect to the longitudinal axis of the tube. Another approach to reinforcing a tubular metallic drive shaft is disclosed in United States Patent No. 4,272,971, which discloses a drive shaft wherein the fiber reinforcing layer is applied to the inside surface of an aluminum`tube.
While the above-discussed fiber-reinforced drive shafts have satisfactory operating characteristics, they have been found difficult and expensive to produce on a high volume production basis.
SUM~.ARY OF THE INVENTION
The present invention relates to a unique fiber reinforced aluminum drive shaft, along with a unique method for producing such drive shafts on a production basis.
The drive shaft of the present invention includes a cylindrical metal tube having a longitudinal axis which, in the preferred embodiment of the invention, is typically constructed of aluminum. An isolation layer of cloth material surrounds the aluminum tube and is adhered to the outex surface of tne tube. A reinforcing fiber layer also surrounds the tube and is adhered to the outer surface of the isolation layer. In accordance with the present invention, the reinforcing fiber layer includes a plurality of individual reinforcing graphite fibers which are orientated parallel to the longitudinal axis of the tube and are uniformly positioned about the circumference of the , .
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tube. ~n the above discussed prior art, the graphitefibers were specifically located non-parallel with the longitudinal axis. Finally, the drive shaft includes a covering layer of fiber material surrounding the tube and adhered to the outer surface of the reinforcin~ fiber layer.
The present invention includes a unique approach to producing the fiber reinforced drive shafts on a production basis. In the method of the presen~ invention, a plurality of cylindrical metal tubes each having a longitudinal axis are coupled to one another in an end-to-end relationship by a plurality of joining plastic plug members to form a longitudinally extending series of metal tubes. The series of metal tubes are fed along a longitudinal path through an apparatus for applying the individual layers of the composite fiber sleeve to the tube.
Initially, the isolation layer of cloth material is applied around the outer surface of the tube. Next, the plurality of individual reinforcing fibers are applied about the circumference of the tube such that the individual reinforcing fibers are parallel to the longitudinal axis of the tube~. Next, the covering layer of fiber material is applied around the outer surface of the reinforcing fiber layer.
While the individual layers are being applied to the tube, a vinylester liquid resin material is applied ~o saturate the individual layers, and the drive shaft having the saturated layers applied thereto is then passed through a heated forming die wherein the liquid resin is cured to firmly adhere the individual layers to the series of tubes.
As the series of tubes having the cured composite sleeve thereon exits the apparatus, the tubes are severed at each of the joining plugs to produce a plurality of individual fiber reinforced drive shafts. In some instances, wherein a connecting member such as a yoke portion or a splined shaft is to be welded to the end of the drive shafts, it ~ ~323~3 has been found desirable to strip a selected end portion of the composite reinforcing layer from the drive shaft to prevent heat damage to the end of the composite sleeve during the welding operation.
The present invention also concerns alternate methods of manufacturing the drive shafts.
BRIEF DESCRIPTION OF THE DRA~JINGS
The above, as well as other advan~ages of the present invention, will become readily apparent to one skilled in the art from the following detailed description of the preferred embodiments of the invention when considered in light of the accompanying drawings, in which:
Fig. 1 is a side elevational view of a fiber reinforced composite tubular element of the present invention, shown for use as a drive shaft;
Fig. 2 is a fragmentary sectional view taken along line 2-2 in Fig. 1 and showing ~he individual layers which constitute the preferred embodiment of the fiber composite sleeve;
Fig. 3 is a schematic diagram showing one method of fabricating the fiber composite tubular element of the invention on a continuous basis wherein the fiber composite sleeve is formed and cured about a series of individual metal tubes temporarily joined together and moving in a longitudinal path;
Fig. 4 is a side elevational view of a composite fiber reinforced tubular element produced according t~ the method schematically illustrated in Fig. 3;
Fiq. 5 is a schematic drawing which illustrates an alternate method of assembly of the drive shaft wherein individual previously formed and cured fiber composite sleeves are slipped over and adhesively secured to an associated metal tube; and Fig. 6 is a schematic drawing which illustrates a further alternate method of manufacture wherein a preformed ~ . '.' ~ '.:' i23~C) and uncured, resin-saturated fiber reinforcing sleeve is slipped over a metal tube member and subsequently cured thereon.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to Fig. 1, there is shown a drive shaft 10 which utilizes a composite tubular element embodying the features of the present invention. The drive shaft 10 incl~des an outer composite fiber reinforcing sleeve 12 which surrounds and is attached to the exterior of a cylindrical metal tube 14. As illustrated, first and second connecting members 16 and 18, which are shown as yoke portions, are connected to opposite ends of the metal tube 14 for coupling the drive shaft between a drive member ~not shown) and a driven member (not shown). While the connecting members are shown as yoke portions for connection to an associated universal joint assembly (not shown), it will be appreciated that other types of connecting members such as, for example, a splined shaft ~o end can be used.
The connecting members 16 and 18 are typically secured to the ends of the metal tube 14 by a welding operation.
To prevent heat damage to the composite sleeve 12 when the connecting members are attached, the ends of the reinforcing sleeve 12 are spaced inwardly from the ends of the metal tube 14 to provide exposed metal end portions 20 and 22. As will appear more fully below, in the preferred method of manufacture, the reinforcing sleeve 12 is initially formed along the entire length of the metal tube 14 and is subsequently stripped from the end portions 20 and 22 by severing it circumferentially with a saw, and peeling it off. In other methods of manufacture, the reinforcing sleeve 12 is formed so that it initially does not cover end portions 20 and 22.
Turning now to Fig. 2, there is shown a cross-section through the tube 14 and the preferred embodiment of the 35~
composite reinforcing sleeve 12. Typically, the metal tube 14 is a cylindrical aluminum tube fabricated in a conventional manner. The length, diameter, and wall thickness of the tube, along with the particular aluminum alloy from which the tube is formed, may vary from application to application, depending on the particular power transmission requirements of the drive shaft. In any event, the use of the composite reinforcing sleeve 12 having the specific construction of the present invention has been found to sufficiently increase the axial stiffness of the aluminum tube such that weight of the tube can be substantially reduced as compared with a ~ubular aluminum drive shaft without the reinforcing sleeve.
The composite reinforcing sleeve 12 basically consists of three sections: an isolation layer 32, a fiber reinforcing layer 34, and a covering layer 36. As will be discussed, in the preferred method of manufacture, the individual layers of the sleeve 12 are bonded to one another and the tube by a vinylester resin.
The isolation layer 32 includes individual layers 32a, 32b, and 32c. The first isolation layer 32a is composed of a plurality of longitudinally extending threads of string material equally spaced about the circumference of the tube. This layer is not essential to the functioning of the invention but, as will be discussed, is provided as a visual indicator to avoid contact of a saw blade (not shown) with the metal tube 14 when striping the end portions of ~he reinforcing sleeve 12 as previously described. In the preferred embodiment of the drive shaft, the lay~r 32a consists of eight longitudinally extending polyester strings equally spaced about the circumerence of the tube.
The second isolation layer 32b is composed of individual strips of a thin screen-like cloth material which extend longitudinally and have overlapping lateral edge portions to completely surround the tube. This layer functions to isolate the fiber reinforcing layer 34, which is typically graphite, from the aluminum tube 14, since it has been found that direct contact between graphite and aluminum results in undesirable electrolytic corrosion.
The exact width of the individual strips will be dependent on the number of strips utilized, along with the outside diameter of the tube. While the number of strips of cloth material which are utilized to surround the tube can vary from application to application, in the preferred embodiment, four individual strips of cloth material are utilized.
The third isolation layer 32c is similar to the first layer 32a, and is comprised of a plurality of longitudinally disposed threads of polyester string uniformally spaced about the circumference of the tube. In the preferred embodiment, eight threads are used. Again, this is not an essential layer, but is provided to form and hold the strips of cloth material in place on the metal tube 14. It will be appreciated that, while the isolation string layers 32a and 32c are shown in Fig. 2 as spacing the isolation cloth layer 32b from both the tube 14 and the fiber reinforcing layer 34, there is actually contact between the layer 32b and the tube 14 and between the layer 32b and the reinforcing layer 34 in the regions between the spaced apart longitudinally extending threads.
The fiber reinforcing layer 34 is typically comprised of graphite and includes a plurality of individual and independent reinforcing fiber strands or "tows" which, in accordance with the present invention, are preferably located parallel to the longitudinal axis of the tube, and uniformly positioned about the isolation layer 32. Each tow consists of a predetermined number of longitudinally disposed, individual graphite fibers. The exact number of tows of graphite which are utilized will depend on the number of individual fibers located in each tow and the overall amount of reinforcing which is desired. In one , ~
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35t) preferred embodiment, ~15 longitudinally disposed tows of graphite fibers are utilized, with each tow being composed of 36,000 individual fibers of graphite.
The covering or protective layer 36 includes individual layers 36a, 36b, and 36c, and functions as a means for retaining the longitudinal graphite strands of the layer 34 adjacent the metal tube 14. The first covering layer 36a is comprised of a circumferential wrapping of fiberglass strands. The number of circumferential wrappings per given length of the tube will be dependent on the amount of graphite which has been applied to the tube, along with the number of individual glass fibers included in each strand~ In the preferred embodiment, each strand is composed of 1,800 continuous glass filaments, and is wrapped about the tube to produce twenty wraps per longitudinal inch.
The second covering layer 36b is another circumferential wrapping, similar to that of the first covering layer 36a, but with polyester string, of a type similar to that used in the first and third isolation layers 32a and 32c. It should be noted that the layers 36a and 36b, although illustrated as overlying layers, do not visually form separate layers, since the strands of one wrapping will typically fall in between the strands of the other, so that layers 36a and 36b appear visually as a single layer.
The third covering layer 36c, which is the outermost layer of the sleeve 12, is applied similarly to and is identical in material characteristics to that of the isolation layer 32b, and provides an outer cloth covering which produces a smooth outer surface on the drive shaft.
Turning now to Fig. 3, there is shown schematically an apparatus 40 for forming composite tubular elements of the type illustrated in Fig. 2 on a continuous basis. As shown in Fig. 3, a plurality of metal tubes, shown as l~a, 14b, 14c, 14d, are interconnected in an end-to-end 3~;0 relationship by a plurality of plug members 42. The plug members ~2, which typically are constructed of a plastic material, are shown as double-ended, with a centrally located protruding annular flange portion 44 having an outer diameter greater than the outside diameter of the tubes. As will be discussed, the protruding flange portion 44, after each layer of the composite sleeve has been applied and cured on the tubes, provides an annular raised portion in the sleeve which functions as a visual reference to define the specific location at which the tubes must sawed apart.
The apparatus 40 includes a plurality of individual application stations which, as discussed in more detail below, are utilized to apply the various materials required to form the composite fiber sleeve on the aluminum tube.
The apparatus also includes a pair of pulling rollers 46 and 48 for pulling the longitudinally extendin~ series of tubes through the apparatus along a longitudinally extending path at a predetermined speed.
As shown in Fig. 3, at first station 50, the first isolation layer 32a of longitudinally extending, circumferentially spaced apart string is applied. String from a plurality of rolls 52 passes through a guide means 54 and an application means 56~ which may be pulleys or the like, into place on the tube 14. Although four rolls are shown, eight rolls are used in the preferred embodiment of the invention. Also, while shown as tapered rolls or spools, the spools used are preferably of the center-feed type, so that the last turn is on the outside, and additional rolls can be connected without interrupting the process.
Then, at a second station 58, the second isolation layer 32b of strips of cloth material is applied. As shown, the layer 32b is applied in four segments. At the second station 58, the material of the second layer 32b is applied from rolls 60 and 62. While not shown in the ~8X3~(~
drawings, the rolls 62 are preferably located along a line which is perpendicular to the line along which the rolls 60 are located. The individual strips are urged into conformance with the shape of tube 14 by a conical preformer 64.
Next, at a third station 66, the third isolation layer 32c of string is applied to form the cloth layer 32b around the tube 14. As with the first station 50, the string from a plurality of rolls 68 passes through a guide means 70 and an application means 72 into position around the tube 14.
At a fourth station 74, approximately half of the fiber reinforcing layer 34 is applied. A set of rolls 76, although shown as six in number for simplicity, actually number approximately half of the total number of graphite tows to be applied. The tows supplied from the rolls 76 pass through individual apertures in a forming ring 78 into conformance with the shape of the tube 14. Then, at a fifth station 80, a resin mixture is supplied from a tank 82 through a line 84 to a dispensing end 86, from which it l 20 coats the first half of the fiber reinforcing layer 34 and the underlying isolation layer 32.
The resin mix contained in the tank 82 is~preferably a vinylester resin mix of the type available under the trade name Derakane. A suitable resin mixture is available from Dow Chemical of Joliet, Illinois under part number 411-35.
In addition, any conventional resin mixture may be used, although it should be selected from among those that remain flexible after curing. Although not shown in the drawings, a catalyst or hardener can be mixed with the resin mixture shortly before application of the mixture to the partially formed sleeve~
At a sixth station 88, the remainder ~f the desired number of graphite tows are applied from a set of rolls 90 through a forming ring 92 into conformance with the tube 14 3S and, at a seventh station 94, are again coated with the , ': : , .
.
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resin mixture from the ~ank 82, through a line 96 and a dispensing end 98.
An eighth station 100 and a ninth station 102 include a spinner head 104 having rolls 106 and 108 for circumferentially wrapping covering layers 36a and 36b respectively. Of course, more than one such spinner head 104 may be provided, and more than a single roll can be used to apply the layers 36a and 36b. As illustrated, the head 104 contains the fiberglass material of the first covering layer 36a on the roll 106 and the polyester string material of the second covering layer 36b on the roll 108.
As previously described, the layers 36a and 36b are circumferential wrappings which, in the preferred embodiment, are applied at a rate of approximately twenty per inch. At a tenth station 110, the resin mix from the tank 82 is again applied, through a line 112 and a dispensing end 114.
Then, at an eleventh station 116, the final layer, the third covering layer 36c, is applied. A set of rolls 118 contain cloth material identical to that contained by the rolls 60, which material is urged into conformance with the tube 14 by a conical performer 120. A set of rolls 122 contain cloth material identical to that contained on the rolls 62, which material is urged into conformance with the tube 14 by a conical entrance 124 of a heated forming die 126. ~s was ~he case with the rolls 60 and 62, the rolls 118 and 122 are preferably located along lines perpendicular to one another. The forming die 126 not only forms the surface of the continuous drive shaft assembly, but also provides appropriate heat input to effect a rapid cure of the resin mixture as the series of drive shafts are pulled through the apparatus 40.
The continuous chain of composite tubular elements 10 is then cut apart at protruding flange portions 48, and stripped in a manner as described above to form exposed metal end portions 20 and 22, to which appropriate ~8~3~0 connecting members can be attached by conventional welding.
The composite tubular element produced by the method of Fig. 3 is shown in Fig. 4 prior to the attachment of the connecting members.
It will be appreciated that other methods can be utilized to produce a fiber-reinforced aluminum drive shaft embodying the principal features of the present invention.
Fox example, Fig. 5 schematically illustrates a method wherein a stiff, performed, precut and previously cured reinforcing sleeve 130 of a predetermined length is provided, with an internal diameter slightly larger than the external diameter of the metal tube 14. As illustrated in Fig. 5, the reinforcing sleeve 130 is slipped into position over a metal tube 132, to which a layer of glue 134 has been applied.
Various types of glues or bonding agents may be used for the glue 134. One such structural adhesive which can be used is commercially known as Metalbond 1133, and is an elastomer modified epoxy material sold by the Narmco division of Celanese Corp, New York, New York. Such adhesives may be applied by brushing or spraying.
Fig. 6 illustrates schematically a further alternate method of making a composite tubular element according to the invention, in which a fiber-reinforced sleeve 140 saturated with uncured resin, but made to appropriate length, is slipped over a metal tube 142 and is subsequently cured to bond the sleeve 140 to the metal tube 142. If desired, an appropriate structural adhesive may be used to assist in bonding the sleeve to the tube. In Fig.
6, the fiber-reinforced sleeve 140 is formed on a mandrel 148, and is saturated with resin from a tank 150 through a line 152 and a dispensing end 15g, or by any other convenient means, such as brushing or spraying. As illustrated, the reinforcing sleeve 140 includes three layers, an inner layer of isolation material applied by rolls 156, an intermediate layer of longitudinally ' extending reinforcing fiber applied by rolls 158, and an outer layer of covering6material applied by rolls 160~
As shown in Fig.-~, there is a supply of metal tubes 142, onto each of which a reinforcing sleeve member 140 is placed by sliding it off mandrel 148 and onto the tube 142, wherein it is urged into position by applying circumferentially forces 162 in any convenient manner, such as by drawing a forming die over it. Then, the reinforcing member 140 is cured in place on the metal tube 142, either by the passage of time without application of heat, or by the application of heat in any convenient manner.
The precise embodiment of the reinforcing sleeve used in the methods illustrated in Figs. 5 and 6 may differ from the construction shown in Fig. 2 and produced by the method of Fig. 3. For example, the first and third isolation layers 32a and 32c of Fig. 2, which provide a visual indicia for stripping the ends of the sleeve in the method of Fig. 3, would not be required in the methods of Figs. 5 and 6, since the reinforcing sleeves are formed to length before application to the metal tube. In addition~ in some instances, the second isolation layer 32b may also not be necessary, since the glue used to retain a previously formed cured or uncured reinforcing sleeve to a metal tube may by itself provide a suitable isolation layer between the graphite and the aluminum. Also, the outer most covering layer 36c of Fig. 2, which is provided to form a smooth exterior surface is not an absolutely necessity, nor is the use of two di~ferent materials, shown as covering layers 36a and 36b to retain the primary reinforcing fiber layer 34 in place.
In accordance with the provisions of the patent statutes, the composite tubular element of the present invention, along with the methods of producing the tubular element, have been illustrated and described in its preferred embodiments. However, it will be appreciated tha~ numerous modifications and variations of the disclosed .
~LZ8'~350 invention will be apparent to one skilled in the art, including re-arrangement in the ordering of layers and the addition or omission of layers, and may be made without departing from the scope of the attached claims.
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TITLE
CO~POSITE TUBULAR ELEMENTS AND METHODS OF FABRICATION
BACKGROUND OF THE INVENTION
The present in~ention relates generally to fiber reinforced tubular elements such as vehicle drive shafts and, in particular, to a graphite reinforced luminum drive shaft and a method for producing such a drive shaft.
Over the past decade, there has been an ongoing endeavor by the industry to reduce the weight of vehicles in order to improve fuel economy. In addition to downsizing and redesigning vehicles to make the most efficient use of $he available space, a great deal of attention has been given to constructing various vehicular components of lighter weight materials. For example, in the area of drive shafts, it has been proposed to replace conventional steel drive shafts with lighter weight aluminum tubes. However, depending on the length of the drive shaft, and the maximum speed at which the drive shaft is to be rotated, vibration problems can arise.
While typically the tubular steel or aluminum drive shafts are adequate to transmit the torsional forces involved, there is a tendency for a shaft to "whip" or resonate mechanically when ~he shaft reaches a certain vehicle speed, typicalIy referred to as a critical speed.
Consequently, in order to overcome the critical speed limitations of single long drive shafts, typically multiple sections of shafts are employed. In these instances, adjacent individual drive shaft sections are connected to one another by means of a universal joint assembly which in turn is supported by a bearing mounting unit affixed to the vehicle frame.
In order to accommodate a longer drive shaft such that the universal joint assemblies and the bearing mounting units can be eliminated, it has been proposed to reinforce metal tubes with a fiber reinforced sleeve portion to ~ ~ ~X 3 ~
increase the axial stiffness of the shaft without substantially increasing its weight. For example, United States Patent Nos. 4,131,701; 4,173,670; and 4,214,932 all disclose fiber composite aluminum drive shafts wherein aluminum tubes are wrapped with alternating layers of resin-impregnated woven fiberglass cloth and resin-impregnated fiber reinforcing sheets. The reinforcing sheets are comprised of continuous unindirectional graphite ~iber layers, with the graphite fibers arranged at angles between +5 to +20 with respect to the longitudinal axis of the tube. Another approach to reinforcing a tubular metallic drive shaft is disclosed in United States Patent No. 4,272,971, which discloses a drive shaft wherein the fiber reinforcing layer is applied to the inside surface of an aluminum`tube.
While the above-discussed fiber-reinforced drive shafts have satisfactory operating characteristics, they have been found difficult and expensive to produce on a high volume production basis.
SUM~.ARY OF THE INVENTION
The present invention relates to a unique fiber reinforced aluminum drive shaft, along with a unique method for producing such drive shafts on a production basis.
The drive shaft of the present invention includes a cylindrical metal tube having a longitudinal axis which, in the preferred embodiment of the invention, is typically constructed of aluminum. An isolation layer of cloth material surrounds the aluminum tube and is adhered to the outex surface of tne tube. A reinforcing fiber layer also surrounds the tube and is adhered to the outer surface of the isolation layer. In accordance with the present invention, the reinforcing fiber layer includes a plurality of individual reinforcing graphite fibers which are orientated parallel to the longitudinal axis of the tube and are uniformly positioned about the circumference of the , .
, ' ' -' ' -' ' ,, Z35~
tube. ~n the above discussed prior art, the graphitefibers were specifically located non-parallel with the longitudinal axis. Finally, the drive shaft includes a covering layer of fiber material surrounding the tube and adhered to the outer surface of the reinforcin~ fiber layer.
The present invention includes a unique approach to producing the fiber reinforced drive shafts on a production basis. In the method of the presen~ invention, a plurality of cylindrical metal tubes each having a longitudinal axis are coupled to one another in an end-to-end relationship by a plurality of joining plastic plug members to form a longitudinally extending series of metal tubes. The series of metal tubes are fed along a longitudinal path through an apparatus for applying the individual layers of the composite fiber sleeve to the tube.
Initially, the isolation layer of cloth material is applied around the outer surface of the tube. Next, the plurality of individual reinforcing fibers are applied about the circumference of the tube such that the individual reinforcing fibers are parallel to the longitudinal axis of the tube~. Next, the covering layer of fiber material is applied around the outer surface of the reinforcing fiber layer.
While the individual layers are being applied to the tube, a vinylester liquid resin material is applied ~o saturate the individual layers, and the drive shaft having the saturated layers applied thereto is then passed through a heated forming die wherein the liquid resin is cured to firmly adhere the individual layers to the series of tubes.
As the series of tubes having the cured composite sleeve thereon exits the apparatus, the tubes are severed at each of the joining plugs to produce a plurality of individual fiber reinforced drive shafts. In some instances, wherein a connecting member such as a yoke portion or a splined shaft is to be welded to the end of the drive shafts, it ~ ~323~3 has been found desirable to strip a selected end portion of the composite reinforcing layer from the drive shaft to prevent heat damage to the end of the composite sleeve during the welding operation.
The present invention also concerns alternate methods of manufacturing the drive shafts.
BRIEF DESCRIPTION OF THE DRA~JINGS
The above, as well as other advan~ages of the present invention, will become readily apparent to one skilled in the art from the following detailed description of the preferred embodiments of the invention when considered in light of the accompanying drawings, in which:
Fig. 1 is a side elevational view of a fiber reinforced composite tubular element of the present invention, shown for use as a drive shaft;
Fig. 2 is a fragmentary sectional view taken along line 2-2 in Fig. 1 and showing ~he individual layers which constitute the preferred embodiment of the fiber composite sleeve;
Fig. 3 is a schematic diagram showing one method of fabricating the fiber composite tubular element of the invention on a continuous basis wherein the fiber composite sleeve is formed and cured about a series of individual metal tubes temporarily joined together and moving in a longitudinal path;
Fig. 4 is a side elevational view of a composite fiber reinforced tubular element produced according t~ the method schematically illustrated in Fig. 3;
Fiq. 5 is a schematic drawing which illustrates an alternate method of assembly of the drive shaft wherein individual previously formed and cured fiber composite sleeves are slipped over and adhesively secured to an associated metal tube; and Fig. 6 is a schematic drawing which illustrates a further alternate method of manufacture wherein a preformed ~ . '.' ~ '.:' i23~C) and uncured, resin-saturated fiber reinforcing sleeve is slipped over a metal tube member and subsequently cured thereon.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to Fig. 1, there is shown a drive shaft 10 which utilizes a composite tubular element embodying the features of the present invention. The drive shaft 10 incl~des an outer composite fiber reinforcing sleeve 12 which surrounds and is attached to the exterior of a cylindrical metal tube 14. As illustrated, first and second connecting members 16 and 18, which are shown as yoke portions, are connected to opposite ends of the metal tube 14 for coupling the drive shaft between a drive member ~not shown) and a driven member (not shown). While the connecting members are shown as yoke portions for connection to an associated universal joint assembly (not shown), it will be appreciated that other types of connecting members such as, for example, a splined shaft ~o end can be used.
The connecting members 16 and 18 are typically secured to the ends of the metal tube 14 by a welding operation.
To prevent heat damage to the composite sleeve 12 when the connecting members are attached, the ends of the reinforcing sleeve 12 are spaced inwardly from the ends of the metal tube 14 to provide exposed metal end portions 20 and 22. As will appear more fully below, in the preferred method of manufacture, the reinforcing sleeve 12 is initially formed along the entire length of the metal tube 14 and is subsequently stripped from the end portions 20 and 22 by severing it circumferentially with a saw, and peeling it off. In other methods of manufacture, the reinforcing sleeve 12 is formed so that it initially does not cover end portions 20 and 22.
Turning now to Fig. 2, there is shown a cross-section through the tube 14 and the preferred embodiment of the 35~
composite reinforcing sleeve 12. Typically, the metal tube 14 is a cylindrical aluminum tube fabricated in a conventional manner. The length, diameter, and wall thickness of the tube, along with the particular aluminum alloy from which the tube is formed, may vary from application to application, depending on the particular power transmission requirements of the drive shaft. In any event, the use of the composite reinforcing sleeve 12 having the specific construction of the present invention has been found to sufficiently increase the axial stiffness of the aluminum tube such that weight of the tube can be substantially reduced as compared with a ~ubular aluminum drive shaft without the reinforcing sleeve.
The composite reinforcing sleeve 12 basically consists of three sections: an isolation layer 32, a fiber reinforcing layer 34, and a covering layer 36. As will be discussed, in the preferred method of manufacture, the individual layers of the sleeve 12 are bonded to one another and the tube by a vinylester resin.
The isolation layer 32 includes individual layers 32a, 32b, and 32c. The first isolation layer 32a is composed of a plurality of longitudinally extending threads of string material equally spaced about the circumference of the tube. This layer is not essential to the functioning of the invention but, as will be discussed, is provided as a visual indicator to avoid contact of a saw blade (not shown) with the metal tube 14 when striping the end portions of ~he reinforcing sleeve 12 as previously described. In the preferred embodiment of the drive shaft, the lay~r 32a consists of eight longitudinally extending polyester strings equally spaced about the circumerence of the tube.
The second isolation layer 32b is composed of individual strips of a thin screen-like cloth material which extend longitudinally and have overlapping lateral edge portions to completely surround the tube. This layer functions to isolate the fiber reinforcing layer 34, which is typically graphite, from the aluminum tube 14, since it has been found that direct contact between graphite and aluminum results in undesirable electrolytic corrosion.
The exact width of the individual strips will be dependent on the number of strips utilized, along with the outside diameter of the tube. While the number of strips of cloth material which are utilized to surround the tube can vary from application to application, in the preferred embodiment, four individual strips of cloth material are utilized.
The third isolation layer 32c is similar to the first layer 32a, and is comprised of a plurality of longitudinally disposed threads of polyester string uniformally spaced about the circumference of the tube. In the preferred embodiment, eight threads are used. Again, this is not an essential layer, but is provided to form and hold the strips of cloth material in place on the metal tube 14. It will be appreciated that, while the isolation string layers 32a and 32c are shown in Fig. 2 as spacing the isolation cloth layer 32b from both the tube 14 and the fiber reinforcing layer 34, there is actually contact between the layer 32b and the tube 14 and between the layer 32b and the reinforcing layer 34 in the regions between the spaced apart longitudinally extending threads.
The fiber reinforcing layer 34 is typically comprised of graphite and includes a plurality of individual and independent reinforcing fiber strands or "tows" which, in accordance with the present invention, are preferably located parallel to the longitudinal axis of the tube, and uniformly positioned about the isolation layer 32. Each tow consists of a predetermined number of longitudinally disposed, individual graphite fibers. The exact number of tows of graphite which are utilized will depend on the number of individual fibers located in each tow and the overall amount of reinforcing which is desired. In one , ~
~ .
:
35t) preferred embodiment, ~15 longitudinally disposed tows of graphite fibers are utilized, with each tow being composed of 36,000 individual fibers of graphite.
The covering or protective layer 36 includes individual layers 36a, 36b, and 36c, and functions as a means for retaining the longitudinal graphite strands of the layer 34 adjacent the metal tube 14. The first covering layer 36a is comprised of a circumferential wrapping of fiberglass strands. The number of circumferential wrappings per given length of the tube will be dependent on the amount of graphite which has been applied to the tube, along with the number of individual glass fibers included in each strand~ In the preferred embodiment, each strand is composed of 1,800 continuous glass filaments, and is wrapped about the tube to produce twenty wraps per longitudinal inch.
The second covering layer 36b is another circumferential wrapping, similar to that of the first covering layer 36a, but with polyester string, of a type similar to that used in the first and third isolation layers 32a and 32c. It should be noted that the layers 36a and 36b, although illustrated as overlying layers, do not visually form separate layers, since the strands of one wrapping will typically fall in between the strands of the other, so that layers 36a and 36b appear visually as a single layer.
The third covering layer 36c, which is the outermost layer of the sleeve 12, is applied similarly to and is identical in material characteristics to that of the isolation layer 32b, and provides an outer cloth covering which produces a smooth outer surface on the drive shaft.
Turning now to Fig. 3, there is shown schematically an apparatus 40 for forming composite tubular elements of the type illustrated in Fig. 2 on a continuous basis. As shown in Fig. 3, a plurality of metal tubes, shown as l~a, 14b, 14c, 14d, are interconnected in an end-to-end 3~;0 relationship by a plurality of plug members 42. The plug members ~2, which typically are constructed of a plastic material, are shown as double-ended, with a centrally located protruding annular flange portion 44 having an outer diameter greater than the outside diameter of the tubes. As will be discussed, the protruding flange portion 44, after each layer of the composite sleeve has been applied and cured on the tubes, provides an annular raised portion in the sleeve which functions as a visual reference to define the specific location at which the tubes must sawed apart.
The apparatus 40 includes a plurality of individual application stations which, as discussed in more detail below, are utilized to apply the various materials required to form the composite fiber sleeve on the aluminum tube.
The apparatus also includes a pair of pulling rollers 46 and 48 for pulling the longitudinally extendin~ series of tubes through the apparatus along a longitudinally extending path at a predetermined speed.
As shown in Fig. 3, at first station 50, the first isolation layer 32a of longitudinally extending, circumferentially spaced apart string is applied. String from a plurality of rolls 52 passes through a guide means 54 and an application means 56~ which may be pulleys or the like, into place on the tube 14. Although four rolls are shown, eight rolls are used in the preferred embodiment of the invention. Also, while shown as tapered rolls or spools, the spools used are preferably of the center-feed type, so that the last turn is on the outside, and additional rolls can be connected without interrupting the process.
Then, at a second station 58, the second isolation layer 32b of strips of cloth material is applied. As shown, the layer 32b is applied in four segments. At the second station 58, the material of the second layer 32b is applied from rolls 60 and 62. While not shown in the ~8X3~(~
drawings, the rolls 62 are preferably located along a line which is perpendicular to the line along which the rolls 60 are located. The individual strips are urged into conformance with the shape of tube 14 by a conical preformer 64.
Next, at a third station 66, the third isolation layer 32c of string is applied to form the cloth layer 32b around the tube 14. As with the first station 50, the string from a plurality of rolls 68 passes through a guide means 70 and an application means 72 into position around the tube 14.
At a fourth station 74, approximately half of the fiber reinforcing layer 34 is applied. A set of rolls 76, although shown as six in number for simplicity, actually number approximately half of the total number of graphite tows to be applied. The tows supplied from the rolls 76 pass through individual apertures in a forming ring 78 into conformance with the shape of the tube 14. Then, at a fifth station 80, a resin mixture is supplied from a tank 82 through a line 84 to a dispensing end 86, from which it l 20 coats the first half of the fiber reinforcing layer 34 and the underlying isolation layer 32.
The resin mix contained in the tank 82 is~preferably a vinylester resin mix of the type available under the trade name Derakane. A suitable resin mixture is available from Dow Chemical of Joliet, Illinois under part number 411-35.
In addition, any conventional resin mixture may be used, although it should be selected from among those that remain flexible after curing. Although not shown in the drawings, a catalyst or hardener can be mixed with the resin mixture shortly before application of the mixture to the partially formed sleeve~
At a sixth station 88, the remainder ~f the desired number of graphite tows are applied from a set of rolls 90 through a forming ring 92 into conformance with the tube 14 3S and, at a seventh station 94, are again coated with the , ': : , .
.
~LZ ~ 3 ~
resin mixture from the ~ank 82, through a line 96 and a dispensing end 98.
An eighth station 100 and a ninth station 102 include a spinner head 104 having rolls 106 and 108 for circumferentially wrapping covering layers 36a and 36b respectively. Of course, more than one such spinner head 104 may be provided, and more than a single roll can be used to apply the layers 36a and 36b. As illustrated, the head 104 contains the fiberglass material of the first covering layer 36a on the roll 106 and the polyester string material of the second covering layer 36b on the roll 108.
As previously described, the layers 36a and 36b are circumferential wrappings which, in the preferred embodiment, are applied at a rate of approximately twenty per inch. At a tenth station 110, the resin mix from the tank 82 is again applied, through a line 112 and a dispensing end 114.
Then, at an eleventh station 116, the final layer, the third covering layer 36c, is applied. A set of rolls 118 contain cloth material identical to that contained by the rolls 60, which material is urged into conformance with the tube 14 by a conical performer 120. A set of rolls 122 contain cloth material identical to that contained on the rolls 62, which material is urged into conformance with the tube 14 by a conical entrance 124 of a heated forming die 126. ~s was ~he case with the rolls 60 and 62, the rolls 118 and 122 are preferably located along lines perpendicular to one another. The forming die 126 not only forms the surface of the continuous drive shaft assembly, but also provides appropriate heat input to effect a rapid cure of the resin mixture as the series of drive shafts are pulled through the apparatus 40.
The continuous chain of composite tubular elements 10 is then cut apart at protruding flange portions 48, and stripped in a manner as described above to form exposed metal end portions 20 and 22, to which appropriate ~8~3~0 connecting members can be attached by conventional welding.
The composite tubular element produced by the method of Fig. 3 is shown in Fig. 4 prior to the attachment of the connecting members.
It will be appreciated that other methods can be utilized to produce a fiber-reinforced aluminum drive shaft embodying the principal features of the present invention.
Fox example, Fig. 5 schematically illustrates a method wherein a stiff, performed, precut and previously cured reinforcing sleeve 130 of a predetermined length is provided, with an internal diameter slightly larger than the external diameter of the metal tube 14. As illustrated in Fig. 5, the reinforcing sleeve 130 is slipped into position over a metal tube 132, to which a layer of glue 134 has been applied.
Various types of glues or bonding agents may be used for the glue 134. One such structural adhesive which can be used is commercially known as Metalbond 1133, and is an elastomer modified epoxy material sold by the Narmco division of Celanese Corp, New York, New York. Such adhesives may be applied by brushing or spraying.
Fig. 6 illustrates schematically a further alternate method of making a composite tubular element according to the invention, in which a fiber-reinforced sleeve 140 saturated with uncured resin, but made to appropriate length, is slipped over a metal tube 142 and is subsequently cured to bond the sleeve 140 to the metal tube 142. If desired, an appropriate structural adhesive may be used to assist in bonding the sleeve to the tube. In Fig.
6, the fiber-reinforced sleeve 140 is formed on a mandrel 148, and is saturated with resin from a tank 150 through a line 152 and a dispensing end 15g, or by any other convenient means, such as brushing or spraying. As illustrated, the reinforcing sleeve 140 includes three layers, an inner layer of isolation material applied by rolls 156, an intermediate layer of longitudinally ' extending reinforcing fiber applied by rolls 158, and an outer layer of covering6material applied by rolls 160~
As shown in Fig.-~, there is a supply of metal tubes 142, onto each of which a reinforcing sleeve member 140 is placed by sliding it off mandrel 148 and onto the tube 142, wherein it is urged into position by applying circumferentially forces 162 in any convenient manner, such as by drawing a forming die over it. Then, the reinforcing member 140 is cured in place on the metal tube 142, either by the passage of time without application of heat, or by the application of heat in any convenient manner.
The precise embodiment of the reinforcing sleeve used in the methods illustrated in Figs. 5 and 6 may differ from the construction shown in Fig. 2 and produced by the method of Fig. 3. For example, the first and third isolation layers 32a and 32c of Fig. 2, which provide a visual indicia for stripping the ends of the sleeve in the method of Fig. 3, would not be required in the methods of Figs. 5 and 6, since the reinforcing sleeves are formed to length before application to the metal tube. In addition~ in some instances, the second isolation layer 32b may also not be necessary, since the glue used to retain a previously formed cured or uncured reinforcing sleeve to a metal tube may by itself provide a suitable isolation layer between the graphite and the aluminum. Also, the outer most covering layer 36c of Fig. 2, which is provided to form a smooth exterior surface is not an absolutely necessity, nor is the use of two di~ferent materials, shown as covering layers 36a and 36b to retain the primary reinforcing fiber layer 34 in place.
In accordance with the provisions of the patent statutes, the composite tubular element of the present invention, along with the methods of producing the tubular element, have been illustrated and described in its preferred embodiments. However, it will be appreciated tha~ numerous modifications and variations of the disclosed .
~LZ8'~350 invention will be apparent to one skilled in the art, including re-arrangement in the ordering of layers and the addition or omission of layers, and may be made without departing from the scope of the attached claims.
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Claims (31)
1. A composite fiber reinforced tubular element particularly useful as a vehicle drive shaft and comprising:
an elongate cylindrical metal tube having a longitudinal axis;
a cylindrical reinforcing sleeve secured to a cylindrical surface of said metal tube and extending longitudinally along said tube, said reinforcing sleeve including an isolation layer adjacent said cylindrical surface of said tube, a reinforcing fiber layer adjacent said isolation layer, and a covering layer adjacent said reinforcing fiber layer;
a cured resin impregnated into and forming a matrix for securing said isolation, fiber reinforcing, and covering layers to each other;
said isolation layer including a plurality of strips of flexible sheet material extending longitudinally along said tube with adjacent ones of said strips having overlapping longitudinal edge portions to prevent direct contact between said reinforcing fiber layer and said cylindrical surface of said tube;
said reinforcing fiber layer increasing the stiffness of said metal tube and being formed of a plurality of separate tows of continuous reinforcing fibers uniformly circumferentially positioned on said isolation layer in parallel relationship to said longitudinal axis of said tube; and said covering layer including a string material circumferentially positioned on said reinforcing fiber layer for maintaining said reinforcing fibers adjacent said isolation layer.
an elongate cylindrical metal tube having a longitudinal axis;
a cylindrical reinforcing sleeve secured to a cylindrical surface of said metal tube and extending longitudinally along said tube, said reinforcing sleeve including an isolation layer adjacent said cylindrical surface of said tube, a reinforcing fiber layer adjacent said isolation layer, and a covering layer adjacent said reinforcing fiber layer;
a cured resin impregnated into and forming a matrix for securing said isolation, fiber reinforcing, and covering layers to each other;
said isolation layer including a plurality of strips of flexible sheet material extending longitudinally along said tube with adjacent ones of said strips having overlapping longitudinal edge portions to prevent direct contact between said reinforcing fiber layer and said cylindrical surface of said tube;
said reinforcing fiber layer increasing the stiffness of said metal tube and being formed of a plurality of separate tows of continuous reinforcing fibers uniformly circumferentially positioned on said isolation layer in parallel relationship to said longitudinal axis of said tube; and said covering layer including a string material circumferentially positioned on said reinforcing fiber layer for maintaining said reinforcing fibers adjacent said isolation layer.
2. A tubular element as defined in claim 1 wherein said covering layer includes a plurality of second strips of flexible sheet material applied to said string material and extending longitudinally along said tube with adjacent ones of said second strips having overlapping longitudinal edge portions.
3. A tubular element as defined in claim 1 wherein said cylindrical surface of said tube is an outer cylindrical surface.
4. A tubular element as defined in claim 1 wherein said reinforcing fiber layer includes graphite fibers.
5. A tubular element as defined in claim 4 wherein said metal tube is made of aluminum.
6. A tubular element as defined in claim 5 including connecting yoke members secured to each end of said metal tube.
7. A composite fiber reinforced tubular element particularly useful as a vehicle drive shaft and comprising:
an elongate cylindrical metal tube having a longitudinal axis;
a cylindrical reinforcing sleeve secured to a cylindrical surface of said metal tube and extending longitudinally along said tube, said reinforcing sleeve including an isolation layer adjacent said cylindrical surface of said tube, a reinforcing fiber layer adjacent said isolation layer, and a covering layer adjacent said reinforcing fiber layer;
a cured resin impregnated into and forming a matrix for securing said isolation, fiber reinforcing, and covering layers to each other;
said isolation layer providing a barrier to prevent direct contact between said reinforcing fiber layer and said cylindrical surface of said tube;
said reinforcing fiber layer increasing the stiffness of said metal tube and being formed of a plurality of separate tows of continuous reinforcing fibers uniformly circumferentially positioned on said isolation layer in parallel relationship to said longitudinal axis of said tube; and said covering layer providing a means for maintaining said reinforcing fibers adjacent said isolation layer.
an elongate cylindrical metal tube having a longitudinal axis;
a cylindrical reinforcing sleeve secured to a cylindrical surface of said metal tube and extending longitudinally along said tube, said reinforcing sleeve including an isolation layer adjacent said cylindrical surface of said tube, a reinforcing fiber layer adjacent said isolation layer, and a covering layer adjacent said reinforcing fiber layer;
a cured resin impregnated into and forming a matrix for securing said isolation, fiber reinforcing, and covering layers to each other;
said isolation layer providing a barrier to prevent direct contact between said reinforcing fiber layer and said cylindrical surface of said tube;
said reinforcing fiber layer increasing the stiffness of said metal tube and being formed of a plurality of separate tows of continuous reinforcing fibers uniformly circumferentially positioned on said isolation layer in parallel relationship to said longitudinal axis of said tube; and said covering layer providing a means for maintaining said reinforcing fibers adjacent said isolation layer.
8. A tubular element as defined in claim 7 wherein said cylindrical surface of said tube is an outer cylindrical surface.
9. A tubular element as defined in claim 7 wherein said isolation layer comprises a plurality of strips of flexible sheet material extending longitudinally along said tube with adjacent ones of the strips having overlapping longitudinal edge portions to prevent direct contact between said reinforcing fiber layer and said cylindrical surface of said tube.
10. A tubular element as defined in claim 9 wherein said isolation layer also includes inner and outer layers respectively disposed on opposite sides of said strips, each of said inner and outer layers comprising a plurality of string members extending longitudinally along said tube and circumferentially spaced apart about said longitudinal tube axis.
11. A tubular element as defined in claim 4 wherein said covering layer comprises a string material circumferentially applied to said reinforcing fiber layer for maintaining said reinforcing fibers adjacent said isolation layer.
12. A tubular element as defined in claim 11 wherein said string material includes continuous glass filaments.
13. A tubular element as defined in claim 12 wherein said covering layer also includes a polyester string material applied circumferentially to said reinforcing fiber layer.
14. A tubular element as defined in claim 13 wherein said covering layer also includes a layer of cloth material applied to said circumferentially applied string materials.
15. A tubular element as defined in claim 14 wherein said covering layer also includes a layer of cloth material applied to said circumferentially applied string material.
16. A tubular element as defined in claim 15 wherein said layer of cloth material includes a plurality of strips of flexible sheet material extending longitudinally along said tube with adjacent ones of said strips having overlapping longitudinal edge portions.
17. A tubular element as defined in claim 7 wherein said reinforcing fiber layer includes graphite fibers.
18. A tubular element as defined in claim 7 wherein said metal tube is made of aluminum.
19. A tubular element as defined in claim 7 including connecting yoke members secured to each end of said metal tube.
20. A method of making a fiber reinforced tubular element comprising the steps of:
(a) providing a cylindrical metal tube having a longitudinal axis;
(b) applying an isolation layer around the outer surface of the metal tube;
(c) applying a reinforcing fiber layer around the outer surface of the isolation layer by positioning a plurality of individual and independent reinforcing fibers uniformly about the circumference of the tube and parallel to the longitudinal axis of the tube;
(d) applying a covering layer around the outer surface of the reinforcing fiber layer;
(e) applying a liquid resin material to the isolation layer, the reinforcing fiber layer, and the covering layer; and (f) curing the liquid resin material to firmly adhere the isolation layer, the reinforcing fiber layer, and the covering layer to the tube to form a fiber reinforced sleeve.
(a) providing a cylindrical metal tube having a longitudinal axis;
(b) applying an isolation layer around the outer surface of the metal tube;
(c) applying a reinforcing fiber layer around the outer surface of the isolation layer by positioning a plurality of individual and independent reinforcing fibers uniformly about the circumference of the tube and parallel to the longitudinal axis of the tube;
(d) applying a covering layer around the outer surface of the reinforcing fiber layer;
(e) applying a liquid resin material to the isolation layer, the reinforcing fiber layer, and the covering layer; and (f) curing the liquid resin material to firmly adhere the isolation layer, the reinforcing fiber layer, and the covering layer to the tube to form a fiber reinforced sleeve.
21. A method of making a fiber reinforced tubular element comprising the steps of:
(a) providing a cylindrical metal tube having a longitudinal axis;
(b) applying an isolation layer of cloth material around the outer surface of the metal tube;
(c) applying a reinforcing fiber layer around the outer surface of the isolation layer by positioning a plurality of individual reinforcing fibers parallel to the longitudinal axis of the tube and uniformly disposed about the circumference of the tube;
(d) applying a covering layer of fiber material around the outer surface of the reinforcing fiber layer;
(e) applying a liquid resin material to the isolation layer, the reinforcing fiber layer, and the covering layer; and (f) curing the liquid resin material to firmly adhere the isolation layer, the reinforcing fiber layer, and the covering layer to the tube to form a fiber reinforced sleeve.
(a) providing a cylindrical metal tube having a longitudinal axis;
(b) applying an isolation layer of cloth material around the outer surface of the metal tube;
(c) applying a reinforcing fiber layer around the outer surface of the isolation layer by positioning a plurality of individual reinforcing fibers parallel to the longitudinal axis of the tube and uniformly disposed about the circumference of the tube;
(d) applying a covering layer of fiber material around the outer surface of the reinforcing fiber layer;
(e) applying a liquid resin material to the isolation layer, the reinforcing fiber layer, and the covering layer; and (f) curing the liquid resin material to firmly adhere the isolation layer, the reinforcing fiber layer, and the covering layer to the tube to form a fiber reinforced sleeve.
22. The method according to claim 21 including, subsequent to step (a), the step of feeding the metal tube along a longitudinal path, and wherein steps (b) through (e) are performed while the tube travels in a longitudinal path.
23. The method according to claim 21 including, subsequent to step (f), the step of stripping a selected portion of the fiber reinforced sleeve from at least one end of the tubular element to provide an exposed metal surface.
24. A method of making fiber reinforced tubular elements comprising the steps of:
(a) providing a plurality of cylindrical metal tubes each having a longitudinal axis;
(b) joining the plurality of metal tubes to form a longitudinally extending series of metal tubes;
(c) feeding the series of joined metal tubes along a longitudinal path; and (d) applying a reinforcing fiber layer around the outer surface of the joined metal tubes as the tubes travel in a longitudinal path, including the step of uniformly positioning a plurality of individual reinforcing fibers about the circumference of the tube such that the individual reinforcing fibers are parallel to the longitudinal axis of the tubes; and (e) severing the series of tubes to produce a plurality of individual fiber reinforced tubular elements.
(a) providing a plurality of cylindrical metal tubes each having a longitudinal axis;
(b) joining the plurality of metal tubes to form a longitudinally extending series of metal tubes;
(c) feeding the series of joined metal tubes along a longitudinal path; and (d) applying a reinforcing fiber layer around the outer surface of the joined metal tubes as the tubes travel in a longitudinal path, including the step of uniformly positioning a plurality of individual reinforcing fibers about the circumference of the tube such that the individual reinforcing fibers are parallel to the longitudinal axis of the tubes; and (e) severing the series of tubes to produce a plurality of individual fiber reinforced tubular elements.
25. A method of making fiber reinforced tubular elements comprising the steps of:
(a) providing a plurality of cylindrical metal tubes each having a longitudinal axis;
(b) joining the plurality of metal tubes with a plurality of joining plug members to form a longitudinally extending series of metal tubes;
(c) feeding the series of joined metal tubes along a longitudinal path;
(d) applying a reinforcing fiber layer around the outer surface of the joined metal tubes as the tubes travel in a longitudinal path, including the step of uniformly positioning a plurality of individual reinforcing fibers about the circumference of the tube such that the individual reinforcing fibers are parallel to the longitudinal axis of the tubes;
(e) applying a liquid resin material to the reinforcing fiber layer;
(f) curing the liquid resin material to firmly adhere the reinforcing fiber layer to the series of tubes to form a fiber reinforced sleeve; and (g) severing the series of tubes at each of the joining plugs to produce a plurality of individual fiber reinforced tubular elements.
(a) providing a plurality of cylindrical metal tubes each having a longitudinal axis;
(b) joining the plurality of metal tubes with a plurality of joining plug members to form a longitudinally extending series of metal tubes;
(c) feeding the series of joined metal tubes along a longitudinal path;
(d) applying a reinforcing fiber layer around the outer surface of the joined metal tubes as the tubes travel in a longitudinal path, including the step of uniformly positioning a plurality of individual reinforcing fibers about the circumference of the tube such that the individual reinforcing fibers are parallel to the longitudinal axis of the tubes;
(e) applying a liquid resin material to the reinforcing fiber layer;
(f) curing the liquid resin material to firmly adhere the reinforcing fiber layer to the series of tubes to form a fiber reinforced sleeve; and (g) severing the series of tubes at each of the joining plugs to produce a plurality of individual fiber reinforced tubular elements.
26. The method according to claim 25 wherein step (d) includes the step of initially applying an isolation layer of cloth material around the outer surface of the tubes and wherein the reinforcing layer is applied to the outer surface of the isolation layer.
27. The method according to claim 25 wherein step (d) includes the step of subsequently applying a covering layer of fiber material around the outer surface of the reinforcing fiber layer.
28. The method according to claim 25 including, subsequent to step (g), the step of stripping a selected portion of the fiber reinforced sleeve from at least one end of the tubular element to provide an exposed metal end surface.
29. A method of making a fiber reinforced tubular element, comprising the steps of:
(a) providing a cylindrical metal tube;
(b) providing a fiber reinforced preformed sleeve including a plurality of individual reinforcing fibers parallel to the longitudinal axis of the sleeve;
(c) positioning the fiber reinforced sleeve over the metal tube; and (d) securing the sleeve to the tube.
(a) providing a cylindrical metal tube;
(b) providing a fiber reinforced preformed sleeve including a plurality of individual reinforcing fibers parallel to the longitudinal axis of the sleeve;
(c) positioning the fiber reinforced sleeve over the metal tube; and (d) securing the sleeve to the tube.
30. A method of making a fiber reinforced tubular element, comprising the steps of:
(a) providing a cylindrical metal tube;
(b) providing a fiber reinforced preformed sleeve impregnated with a cured resin and including a plurality of individual reinforcing fibers parallel to the longitudinal axis of the sleeve;
(c) applying an adhesive to a portion of the outer surface of the metal tube; and (d) positioning the fiber reinforced sleeve over the metal tube adjacent the adhesive to secure the sleeve to the tube.
(a) providing a cylindrical metal tube;
(b) providing a fiber reinforced preformed sleeve impregnated with a cured resin and including a plurality of individual reinforcing fibers parallel to the longitudinal axis of the sleeve;
(c) applying an adhesive to a portion of the outer surface of the metal tube; and (d) positioning the fiber reinforced sleeve over the metal tube adjacent the adhesive to secure the sleeve to the tube.
31. A method of making a fiber reinforced tubular element, comprising the steps of:
(a) providing a cylindrical metal tube;
(b) providing a fiber reinforced preformed sleeve impregnated with an uncured and curable resin material, said sleeve including a plurality of individual reinforcing fibers parallel to the longitudinal axis of the sleeve:
(c) placing the uncured fiber reinforced sleeve over the metal tube; and (d) curing the curable resin to firmly adhere the sleeve to the tube.
(a) providing a cylindrical metal tube;
(b) providing a fiber reinforced preformed sleeve impregnated with an uncured and curable resin material, said sleeve including a plurality of individual reinforcing fibers parallel to the longitudinal axis of the sleeve:
(c) placing the uncured fiber reinforced sleeve over the metal tube; and (d) curing the curable resin to firmly adhere the sleeve to the tube.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US85771786A | 1986-04-30 | 1986-04-30 | |
| US857,717 | 1986-04-30 |
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| CA1282350C true CA1282350C (en) | 1991-04-02 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000533849A Expired - Lifetime CA1282350C (en) | 1986-04-30 | 1987-04-03 | Composite tubular elements and methods of fabrication |
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| JP (1) | JPH0818409B2 (en) |
| KR (1) | KR950011948B1 (en) |
| AU (3) | AU591763B2 (en) |
| BR (1) | BR8701503A (en) |
| CA (1) | CA1282350C (en) |
| DE (1) | DE3711258C2 (en) |
| ES (1) | ES2004398A6 (en) |
| FR (1) | FR2598115B1 (en) |
| GB (1) | GB2189862B (en) |
| IT (1) | IT1205783B (en) |
| MX (1) | MX168886B (en) |
| SE (1) | SE505566C2 (en) |
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|---|---|---|---|---|
| FR2632244B1 (en) * | 1988-06-03 | 1991-02-15 | Pechiney | METAL-FIBER-RESIN COMPOSITE MATERIAL AND METHOD FOR MANUFACTURING THEREOF WITH JOINTING SPIRALS |
| GB2222653A (en) * | 1988-09-07 | 1990-03-14 | Ti Corporate Services | Hollow tubular structures of fibre reinforced plastics material and method for their production |
| DE19908604A1 (en) * | 1999-02-27 | 1999-12-30 | Daimler Chrysler Ag | Driveshaft for motor vehicles |
| DE102010063094A1 (en) * | 2010-12-15 | 2012-06-21 | Bayerische Motoren Werke Aktiengesellschaft | Method for producing a material-hybrid component |
| US10875265B2 (en) | 2019-01-08 | 2020-12-29 | Goodrich Corporation | Hybrid metallic/composite arrangement for torque, bending, shear, and axial loading |
| CN117463901B (en) * | 2023-12-25 | 2024-03-15 | 丰果(中国)有限公司 | Alloy pipe layer forming device of explosion-proof pipe |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB916761A (en) * | 1958-05-13 | 1963-01-30 | Permali Ltd | Improvements relating to the manufacture of pipes and other articles of hollow crosssection |
| US3202560A (en) * | 1961-01-23 | 1965-08-24 | Rock Island Oil & Refining Co | Process and apparatus for forming glass-reinforced plastic pipe |
| US3400426A (en) * | 1964-12-21 | 1968-09-10 | Koppers Co Inc | Cut-off mechanism |
| US3433696A (en) * | 1965-10-15 | 1969-03-18 | Koch Ind Inc | Apparatus for making filament reinforced plastic pipe |
| GB1231091A (en) * | 1967-04-24 | 1971-05-05 | ||
| DE1704761A1 (en) * | 1967-06-10 | 1971-06-03 | Kloeckner Werke Ag | Process for the production of glass fiber reinforced pipes |
| GB1305198A (en) * | 1969-10-24 | 1973-01-31 | ||
| GB1351732A (en) * | 1970-03-19 | 1974-05-01 | Secr Defence | Fishing rods and processes for their manufacture |
| US3813098A (en) * | 1970-06-22 | 1974-05-28 | H Fischer | Prestressed elements |
| GB1326943A (en) * | 1970-08-06 | 1973-08-15 | Fischer H C | Stressed elements and production thereof |
| DE2520623B2 (en) * | 1975-05-09 | 1980-07-31 | Messerschmitt-Boelkow-Blohm Gmbh, 8000 Muenchen | Fiber-reinforced plastic tube |
| US4089190A (en) * | 1976-04-14 | 1978-05-16 | Union Carbide Corporation | Carbon fiber drive shaft |
| US4082277A (en) * | 1976-08-03 | 1978-04-04 | Auken Richard L Van | Golf club shaft |
| US4047731A (en) * | 1976-09-10 | 1977-09-13 | Exxon Research And Engineering Company | Bicycle frame |
| US4173670A (en) * | 1977-05-27 | 1979-11-06 | Exxon Research & Engineering Co. | Composite tubular elements |
| US4171626A (en) * | 1978-03-27 | 1979-10-23 | Celanese Corporation | Carbon fiber reinforced composite drive shaft |
| JPS5515801A (en) * | 1978-07-15 | 1980-02-04 | Exxon Research Engineering Co | Tubular compound body and its preparation |
| US4272971A (en) * | 1979-02-26 | 1981-06-16 | Rockwell International Corporation | Reinforced tubular structure |
| US4214932A (en) * | 1979-05-17 | 1980-07-29 | Exxon Research & Engineering Co. | Method for making composite tubular elements |
| US4248062A (en) * | 1979-10-05 | 1981-02-03 | Shakespeare Company | Drive shaft assembly and method for making same |
| DE3121241C2 (en) * | 1980-05-28 | 1984-07-19 | Dainippon Ink And Chemicals, Inc., Tokio/Tokyo | Method of manufacturing a composite plastic pipe from thermoplastic resin |
| FR2546473B1 (en) * | 1983-05-24 | 1987-12-11 | Verre Tisse Sa | TUBULAR MATERIAL BASED ON A RESIN REINFORCED BY A TEXTILE MATERIAL AND FRAME OF A BICYCLE OR SIMILAR VEHICLE MADE FROM SUCH A MATERIAL |
| JPS604052A (en) * | 1983-06-22 | 1985-01-10 | 横浜ゴム株式会社 | Corrosion-resistant structure |
| DE3528629A1 (en) * | 1985-08-09 | 1987-02-12 | Man Technologie Gmbh | METHOD FOR PRODUCING A ROTOR TUBE |
-
1987
- 1987-03-06 IT IT47815/87A patent/IT1205783B/en active
- 1987-03-30 AU AU70784/87A patent/AU591763B2/en not_active Expired
- 1987-04-02 MX MX005867A patent/MX168886B/en unknown
- 1987-04-02 BR BR8701503A patent/BR8701503A/en not_active IP Right Cessation
- 1987-04-03 SE SE8701401A patent/SE505566C2/en not_active IP Right Cessation
- 1987-04-03 KR KR1019870003196A patent/KR950011948B1/en not_active IP Right Cessation
- 1987-04-03 ES ES8700967A patent/ES2004398A6/en not_active Expired
- 1987-04-03 GB GB8708016A patent/GB2189862B/en not_active Expired - Lifetime
- 1987-04-03 DE DE3711258A patent/DE3711258C2/en not_active Expired - Fee Related
- 1987-04-03 CA CA000533849A patent/CA1282350C/en not_active Expired - Lifetime
- 1987-04-29 FR FR878706118A patent/FR2598115B1/en not_active Expired - Lifetime
- 1987-04-30 JP JP62104887A patent/JPH0818409B2/en not_active Expired - Fee Related
-
1990
- 1990-03-09 AU AU51237/90A patent/AU644784B2/en not_active Expired
-
1993
- 1993-10-18 AU AU49068/93A patent/AU666584B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2598115A1 (en) | 1987-11-06 |
| KR870010332A (en) | 1987-11-30 |
| DE3711258A1 (en) | 1987-10-08 |
| FR2598115B1 (en) | 1991-02-15 |
| IT8747815A0 (en) | 1987-03-06 |
| BR8701503A (en) | 1988-01-19 |
| SE8701401L (en) | 1987-10-31 |
| JPS62267133A (en) | 1987-11-19 |
| MX168886B (en) | 1993-06-14 |
| DE3711258C2 (en) | 2003-11-13 |
| IT1205783B (en) | 1989-03-31 |
| JPH0818409B2 (en) | 1996-02-28 |
| GB8708016D0 (en) | 1987-05-07 |
| SE8701401D0 (en) | 1987-04-03 |
| ES2004398A6 (en) | 1989-01-01 |
| GB2189862B (en) | 1991-02-20 |
| AU644784B2 (en) | 1993-12-23 |
| AU7078487A (en) | 1987-10-08 |
| KR950011948B1 (en) | 1995-10-12 |
| SE505566C2 (en) | 1997-09-15 |
| AU666584B2 (en) | 1996-02-15 |
| AU5123790A (en) | 1990-08-02 |
| AU591763B2 (en) | 1989-12-14 |
| GB2189862A (en) | 1987-11-04 |
| AU4906893A (en) | 1994-01-13 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed | ||
| MKEC | Expiry (correction) |
Effective date: 20121205 |