On Nov. 20th of 2004, I was discussing the purchase of carbon fiber sleeves for a project that involved the making of a carbon fiber bicycle fork. During the discussion with the salesperson regarding the different types of carbon fiber weave, I asked about the durability and the lightness of the carbon fiber sleeve when encapsulated in a resin. After my discussions with the salesperson, I realized that for my application the resin would need to be pulled through the layers of carbon in order to allow the structure to withstand impact. Once cured, it would need to be heat treated and painted in order to be able to withstand direct UV light from the sun. At this point, I found that the resin used for this process could only withstand an average temperature about 400 degrees Fahrenheit. From experimenting with carbon fiber and the limitations it holds, I found that the carbon fiber could hold up in continuous contact with open flame, without significant damage. I then reached the conclusion that carbon fiber would be a valuable material to use in extreme heat situations, such as vehicle exhaust systems.
I decided to fabricate an exhaust, header/tubing system for an engine which is composed of, but not limited to, carbon fiber reinforced matrix composite material, so as to be light weight, low heat conductive, high temperature resistant, and cool rapidly.
I discovered a new method of making the exhaust, header/tubing system which consists of the following steps. The first step is to form the desired component from an collapsible apparatus, using multiple sleeves of fiber, but not limited to carbon, material that has a uniform weave. The fiber, but not limited to carbon, covers the entirety of the mold, then fills in the uniform weave with an alumina-silicate resin. This process forms an exhaust, header/tubing system structure from the mixture of fiber, but not limited to carbon, material by placing the first layer of carbon and resin, for a given amount of time sufficient to convert the resin to a carbon composite matrix. This is done by firing the exhaust component shaped structure at a temperature and period of time sufficient to convert the aluminum-silicate resin to a carbon fiber composite, and a carbon fiber composite exhaust (CMX) is formed. By repeating the following procedures, one can obtain a desired strength that will be sufficient to allowing the formed component the capability to span a series of length between exhaust mounts/hangers.
Conventional exhaust systems are heavy and cumbersome, as well as consisting of metals that conducts heat, as well as providing slow heat distribution. Metallic exhaust systems are bonded together by welds. If a weld protrudes in the inner portion of an exhaust pipe, then the air flow becomes constrained, and engine efficiency is negatively impacted. The difficulty with metal welds is that it is not readily apparent if the welds protrude into the inside of the exhaust pipes. A high rate of exhaust gas flow is a necessity in engine performance. Metals have a limited capacity to form small bend radii before becoming kinked; good pipes are made with U and J bends, so that compact bends can be assembled using parts of the tubes; however, compound curves create a less direct path for gases to escape. Interior smoothness, i.e. protruding welds, and compound bends are factors considered by designers wanting to achieve maximum performance. The extreme periods of high temperatures within of the exhaust system presents yet another problem, which those skilled in the field would agree is a difficultly. Heat is a result of high power generation; a key component that radiates this heat is the exhaust system consisting of the header, tubing, and tail pipe components. In engine performance prior art have used exotic steels and ceramics to help optimize the exhaust, but with limited success. Methods of coating the components with a ceramic lining or paint have been useful to help dampen the extreme heat but still the problem remains of power loss due to excessive heat created by the exhaust header, tubing, and tail pipe components
Those skilled in the art will clearly see the advantages of this invention. The drawings that have been selected are accompanied by a detailed description that can be briefly described as follows:
FIG. 1 is a drawing of a prior art exhaust manifold, complete with cross-section views.
FIG. 2 is a drawing of the present exhaust manifold/tubing system invention (CMX), including a perspective and a cross-section view of a CMX system.
FIG. 1 illustrates a typical combustion engine manifold. The manifold 1 is a prior art metallic manifold. Cross-section FIG. 1A is a detailed view of manifold 1, and layer 2 is metallic, with no additives used, such as a composite or matrix material. FIG. 1B is a cross-section of a manifold (not shown) with a ceramic lining. Layer 3 is a metallic, with a lining of ceramic coating 4 on the inside to help prevent the metallic from heating. FIG. 2 represents a carbon fiber composite exhaust (CMX) header 5, consisting of layers of carbon fiber and resin. FIG. 2A is a cross-section of the CMX header 5. Layer 7 is a composite; that is, a fiber and resin formed from a collapsible apparatus in the shape of the desired form that is needed for the appropriate application. Layer 8 is a coating of resin that insulates layer 7. Layer 9 is a composite; that, is, a fiber and resin formed to protect the coat of insulating resin. Layer 10 is a composite; that is, a fiber and resin that add strength and protect from foreign objects that might damage the insulating fiber and resin composite layers 7-9. The fully assembled tube 11 consists of layers 7-10 that have been formed over each other. The metallic, but not limited to metallic-based material, compression/connection tube 6, is then pressed and bonded with a resin, giving the exhaust system a firm connection that will not leak, or compress between the combustion engines exhaust ports, located on the cylinder heads, on either one or both sides of the combustion engine.
There are numerous advantages that CMX can offer for an internal combustion engine over the current metallic, metallic ceramic matrix and ceramic exhaust components.
There are many distinct advantages offered by a CMX internal combustion engine exhaust, header/tubing system over current metal manifolds, which are described as follows:
1) Being that the exhaust, header/tubing system is a fiber composite ceramic, it inherently has a better non-insulating capability than the metallic counterpart, thus reducing the heat load in the engine compartment.
2) Being that the exhaust, header/tubing system is a fiber reinforced composite, it is inherently corrosion resistant.
3) Being that the exhaust, header/tubing system is a fiber reinforced composite, it inherently is more temperature resistant than its metallic counterpart.
4) Being that the exhaust, header/tubing system is a fiber reinforced composite, it inherently is substantially lighter than its metallic counterpart
5) Being that the exhaust, header/tubing system is a fiber reinforced composite, it reduces the heat retained to a minimal factor compared to its metallic counterparts.
6) Being that the exhaust, header/tubing system is a fiber reinforced composite, and it is manufactured with a water-based resin, it has the inherent potential for recycling for future CMX applications.
Fabrication of a CMX Exhaust Header/Tubing System.
First the mold process,
This process consists of determining which component of the exhaust will be fabricated. Then a mold, in the proper shape, will be constructed out of a collapsible apparatus.
Second the lay up,
Depending on the application, a fiber material such as, but not limited to, carbon will be either layered on or pulled over as a sleeve to conform to the mold.
Third saturating,
The fiber will now be saturated with a resin. In this example, an alumina-silicate resin is diluted to a ratio of 1 part resin to 5 parts water. This step may also include squeezing, and/or injecting, the mixture of resin and water into the form of the component mold of the structure.
Fourth firing,
The resin-saturated structure is then heated as per the following example, but it should be noted that there are numerous definitions of heating and cooling cycles, not limited to the example presented here:
A) Heat from ambient temperature to 300 degree F.
B) Hold at 300 degree F. for 15 minutes
C) Cool at ambient temperature. For 15 minutes.
Fifth mold removal,
The collapsible apparatus is now removed from the CMX composite, which is then saturated by brushing on a non-diluted alumina-silicate resin.
Sixth firing,
The resin-saturated structure is heated as per the following example, but it should be noted that there are numerous definitions of heating and cooling cycles, not limited to the example presented here:
A) Heat from ambient temperature to 450 degree F.
B) Hold at 450 degrees F. for 30 minutes.
C) Cool at ambient temperature for 15 minutes
Seventh adding strength,
Multiple layers are utilized in this application, each adhering to the foregoing procedure.
Eighth insertion of connection/compression tube,
The connection/compression tube, but not limited to metallic material, is then inserted. These tubes are used as a surface at which the exhaust, header/tubing system may be jointed with the internal combustion engine, and then bonded with resin. Then the component must be fired in a procedure as follows:
A) Heat from ambient temperature to 300 degrees F.
B) Hold at 300 degrees F. for 30 minutes
C) Cooled at ambient temperatures for 1 hour.
Ninth the coating,
Once the exhaust, header/tubing system has gone through the previously stated steps, described above, it is then coated with a, but not limited, to high-temperature silicone paint. Once coating, the component is then fired.
A) Hold at ambient temperature for 1 hour.
B) Heat from ambient temperature to 200 degrees F.
C) Hold at 200 degrees F. for 15 minutes.
D) Cool at ambient temperature for 1 hour.
There are numerous definitions for desired thermal heat treatments, and the foregoing is only one example, not intended to be exhaustive.
This process is an example of how a carbon and resin, but not limited to, carbon fiber and alumina-silicate resin can be formed in to an exhaust, header/tubing system for, but limited to, a motorcycle and automobile.
The design of the mold for each system will differ as the technology surrounding internal combustion engines changes, as one experienced in this field would understand.
This invention is applicable to any internal combustion engine such as, but not limited to, 2 cycle engines, 4 cycle engines or 4/6/8/10/12/16 cylinder internal combustion engines.
Use of Carbon Fiber Composite Exhaust (CMX)
New regulations have been made for the 2005 season of Formula 1 racing. These regulations have heavily impacted the performance requirements of the car, a person associated with the production of these high performance automobiles would agree.
In part A, it is stated that only one engine may be used for every two race weekend. This means that unlike previous seasons where engines could be changed at any point, the driver must be more cautious when running the engine at high revolutions (RPS) to insure that the engine does not fail due to overheating.
By having a CMX system instead of a metallic exhaust, the engine would have a larger margin heat fluctuation, which causes temporary high peak temperatures, because the CMX system would not conduct as much heat as the metallic counterpart. During pit stops in a race situation, the CMX system would quickly cool and enable the mechanics to start and complete work on the engine components more quickly without added risk of severe burns.
In part B, the changed rules on the aerodynamics resulted in having to create and modify the aerodynamics of the car, so that the proper down force could be achieved. These modifications cause overheating complications within the airflow in the engine compartment.
Since a CMX system would emit less heat than the metallic counterpart, the use of a CMX system would result in a cooler engine compartment, minimizing the overheating complications brought on by the aerodynamic modifications.
Overall, having a CMX system on a high performance engine, such as a Formula 1 race car, will benefit the race crew by having a cooler engine compartment; as well as allowing mechanics, when having to fix a problem that is located near the engine, to have an exhaust system that has cooled dramatically within seconds. This fast-cooling ability of a CMX system can help prevent severe burns that could be given by its metallic counterparts and provide a larger period of time for working repairs within a given period of time.