Patent Publication Number: US-6905536-B2

Title: Increased surface area hydrocarbon adsorber

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to a hydrocarbon adsorbing or absorbing device that may be used in the induction system of a motor vehicle, and in particular, to a hydrocarbon adsorbing device having a configuration for providing an increased surface area of adsorbent material. 
   There continues to be a push to reduce emissions from internal combustion engines. One manner in which emissions are generated from an internal combustion engine is when the engine is shut off. Fuel which has been released from fuel injectors, but has not been consumed prior to engine shut down, may evaporate outwardly through the intake manifold, the intake air ducts and air filter to eventually escape into the atmosphere and contribute to air pollution. 
   In an effort to reduce these types of inadvertent evaporative emissions, many types of filters have been developed. Examples of filters for use in the intake system of a vehicle are found in U.S. Pat. No. 6,432,179 to  Lobovsky  et al. and U.S. Patent Application Publication No. U.S. 2002/0029693 to  Sakakibara  et al., both of which are incorporated herein by reference. The publication of  Sakakibara  et al. discloses several embodiments of hydrocarbon adsorbing devices having a case surrounding an inner cylinder portion. A hydrocarbon adsorbent material is provided in a chamber defined by the case and the inner cylinder portion. The inner cylinder portion has a central bore that extends through its length to permit induction air to pass therethrough, and also has windows that allow any hydrocarbons in the induction system to pass through a filter surrounding the inner cylinder portion to the hydrocarbon adsorbent material in the chamber to be adsorbed thereby. 
   The publication to  Sakakibara  et al. also discloses one embodiment, wherein the filter element is bent in a waveform in either the axial direction of the air intake passages or in a peripheral direction of the air intake passage.  Sakakibara  et al. indicates that providing the filter element in a waveform increases the surface area and efficiency of the adsorbent material. Although the waveform designs in the filter element disclosed by  Sakakibara  et al. increase the exposed surface area of the hydrocarbon adsorbent material in the chamber, it is an object of the present invention to provide a hydrocarbon adsorbing device with an even greater exposed surface area of hydrocarbon adsorbing material and having increased efficiency. 
   SUMMARY OF THE INVENTION 
   The object of the invention has been met by providing in one embodiment a hydrocarbon adsorbing device capable of adsorbing or absorbing and subsequently releasing hydrocarbons in the induction system of a motor vehicle. The hydrocarbon adsorbing device includes an inner cylinder that contains a hydrocarbon adsorbing material and an outer cylinder that also contains a hydrocarbon adsorbing material. The inner cylinder is located within the outer cylinder. The hydrocarbon adsorbing device also includes an intermediate member with a hydrocarbon adsorbing material that is located between the inner cylinder and the outer cylinder. 
   Another feature of the invention is to provide an embodiment of a hydrocarbon adsorbing device that is capable of adsorbing or absorbing and subsequently releasing hydrocarbons in the induction system of a motor vehicle that includes a cylinder of hydrocarbon adsorbing material; a pleated member of hydrocarbon adsorbing material attached to and extending from the cylinder; and a flange attached to the cylinder. The flange extends outwardly from the cylinder and may be used to locate the hydrocarbon adsorbing device in the induction system. 
   It is also a feature of the invention to provide an embodiment of a hydrocarbon adsorbing device that is capable of adsorbing or absorbing and subsequently releasing hydrocarbons in the induction system of a motor vehicle that includes an inner member having a hydrocarbon adsorbing material and an outer member having a hydrocarbon adsorbing material. The inner member is located within the outer member, and an intermediate member having a hydrocarbon adsorbing material is located between the inner member and the outer member and extends therebetween. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic view showing an embodiment of an increased surface area hydrocarbon absorbing device in the induction system of a vehicle; 
       FIG. 2  is a perspective view of the hydrocarbon absorbing device from  FIG. 1  removed from the induction system; 
       FIG. 3  is a cross-sectional side view of the hydrocarbon adsorbing device taken along lines  3 — 3  of  FIG. 2 ; 
       FIG. 4  is an end view of the hydrocarbon adsorbing device of  FIG. 2  as viewed from the end with the flange; 
       FIG. 5  is an end view of a second embodiment of an increased surface area hydrocarbon adsorbing device; 
       FIG. 6  is an end view of a third embodiment of an increased surface area hydrocarbon adsorbing device; and 
       FIG. 7  is an end view of a fourth embodiment of an increased surface area hydrocarbon adsorbing device. 
   

   DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
   In  FIG. 1 , a block diagram of a motor vehicle is shown generally indicated as  10 . The motor vehicle includes an induction system generally indicated as  12  for receiving air through an intake port  14  For supplying the air to facilitate combustion in an engine (not shown). The induction system  12  also has an air cleaner  16  and a hydrocarbon adsorbing or absorbing device generally indicated as  20 , which includes a hydrocarbon adsorbing member  22 , for use in adsorbing any unburned fuel left in the induction system  12  after engine shutdown. 
   Now referring to  FIGS. 2-4 , the first embodiment of the hydrocarbon adsorbing member  22  is shown. The hydrocarbon adsorbing member  22  includes an outer cylinder or member  24 , an inner cylinder or member  26 , and an intermediate or pleated member  28 . Inner cylinder  26  is located within the outer cylinder  24  such that the inner cylinder  26  and the outer cylinder  24  share a common axis A, and the intermediate member  28  is located between the cylinders  26 ,  24 . In the embodiment shown, the outer cylinder  24 , inner cylinder  26  and intermediate member  28  all include a malleable hydrocarbon adsorbent material. The hydrocarbon adsorbent material may be provided in a sheet having a thickness or from 0.030 inches to 0.060 inches or other appropriate thickness as required. The material advantageously exhibits a cardboard-like appearance and consistency but is thermoplastically deformable so that it may be heated and bent and retain the bent shape. The thermoplastic material serves as a substrate for an adsorbent or absorbent composition, which may be activated carbon material or may include any other known material for absorbing hydrocarbons, such as zeolite, porous polymer beads, an inorganic porous material, such as silica gel, an activated aluminum, or the like. 
   Alternatively, the substrate may be formed of a thermoset resin impregnated paper, such as, or similar to, the filter material typically incorporated in pass through air filters for automotive applications. 
   An economical implementation of the invention may include that the adsorbent or absorbent material in the form of a particulate be attached to the substrate by means of a contact adhesive, or by a thermoset resin. In the case of a thermoplastic substrate, a polymer may be chosen having significant tack, or adhesion at temperatures elevated above room temperature. In such thermoplastic substrates, the sorbent material may be adhered to the substrate by thermobonding, optionally benefiting by the application of pressure to the sorbent material to enhance adhesion to the substrate. 
   Further, in the case of a thermoset resin impregnated paper, the sorbent material may be adhered to the substrate independent of the impregnation of the paper to provide strength and moisture resistance to the paper material. Also, the sorbent material may be added to the shaped impregnated paper as a subsequent measure by means of a subsequent application of thermoset resin. Still further, the thermoset impregnated filter paper may be partially cured to what is known as a “B” stage, to form a ‘pre-preg’. The pre-preg may be heated to soften the thermoset resin, the sorbent material adhered to it, and then it can be configured to its final shape in a subsequent operation. 
   Intermediate member  28  may consist of a single sheet of material that is folded along fold lines  30   a ,  30   b , with the fold lines  30   a ,  30   b  abutting alternately against the outer cylinder  24  and the inner cylinder  26 , respectively. In this manner, the intermediate member  28  extends completely, around the circumference of the inner cylinder  26 . Alternatively, a plurality of sheets of material may form the intermediate member  28 . 
   The hydrocarbon adsorbing member  22  may include a flange  32  attached to one end of the outer cylinder  24  and extending outwardly therefrom. The flange  32  may comprise the same malleable hydrocarbon adsorbing material as the rest of the hydrocarbon adsorbing member  22 , or it may be made from a structural non-hydrocarbon adsorbing material, such as plastic, aluminum, or stainless steel. 
   The hydrocarbon adsorbing member  22  may be assembled from square or rectangular sheets of the hydrocarbon adsorbing material which are cut, rolled into cylindrical shapes, and joined along mating edges. Both the outer cylinder  24  and inner cylinder  26  are formed in this manner. The mating ends of the sheets may be joined with an adhesive, stapes, heat sealing, or any other well-known joining means. Intermediate member  28  is also fabricated from a square or rectangular sheet of hydrocarbon adsorbing material and thermoplastically folded along the fold lines  30   a ,  30   b , which extend parallel to axis A. As should be readily apparent, the sheet of hydrocarbon material is folded in opposite directions from the plane of the hydrocarbon adsorbing material to make fold lines  30   a  alternating with fold lines  30   b . As with the inner and outer cylinders  26 ,  24 , mating ends of the sheet of material making up intermediate member  28  are joined to one another using the same techniques as discussed above for the inner and outer cylinders  26 ,  24 . The hydrocarbon adsorbing member  22  may also be fabricated by molding, extrusion or other known means in addition to the method outlined above. 
   The intermediate member  28  is also joined to the outer cylinder  24  and the inner cylinder  26  along the respective fold lines  30   a ,  30   b , using an adhesive or other well-known joining means. In this manner, sufficient structural rigidity is provided in the hydrocarbon adsorbing member  22  to contribute integrity for utilization in the induction system  12 . 
   Flange  32  may also be adhered to the outer flange  24  using an adhesive or other well-known means, and the flange  24  may be used to locate the hydrocarbon adsorbing member  22  in the induction system  12 . As shown in  FIG. 1 , hydrocarbon adsorbing member  22  is placed directly in the induction system  12  with the flange  24  located at a juncture. However, it should be realized that hydrocarbon adsorbing member  22  may also be placed in a separate housing (not shown) before placing the hydrocarbon adsorbing member  22  in the induction system  12 . 
   In operation, air is received through air intake port  14  and passes through air cleaner  16  and the hydrocarbon adsorbing member  22  en route to the engine. The direction of the air flow is along axis A, such that the hydrocarbon adsorbing member  22  provides little resistance or restriction to the air flow. Upon engine shutdown, any unburned fuel that would escape to the atmosphere through the induction system  12  is substantially absorbed or adsorbed on the surfaces of the adsorbing device  20  before being released into the atmosphere through the air intake port  14 . Applicant&#39;s invention provides an efficient means of adsorbing the hydrocarbon based upon the increased surface area or hydrocarbon adsorbing material over known prior art. In the embodiment of  FIGS. 1-4 , hydrocarbons may be adsorbed on an inner surface of outer cylinder  24 ; on both the inner and outer surfaces or the inner cylinder  26 ; on both surfaces of the intermediate member  28 ; and by any exposed surfaces of flange  32 . 
   When the engine is operated, environmental air will flow through air intake port  14  and the hydrocarbon adsorbing member  22  en route to the engine. The air flowing past the member will purge the hydrocarbons from the hydrocarbon adsorbing members carrying them to the engine to be combusted. 
   Now referring to  FIG. 5 , an alternate embodiment hydrocarbon adsorbing member is shown generally indicated as  122 . The hydrocarbon adsorbing member  122  is similar to hydrocarbon adsorbing member  22  except in the configuration of the intermediate member. In this embodiment, an intermediate folded member  128  is utilized that includes radiused folds  130   a ,  130   b  in place of the angled folds of intermediate member  128 . The hydrocarbon adsorbing member  122  is assembled and operates in a similar manner as the hydrocarbon adsorbing member  22 . 
   A third embodiment of a hydrocarbon adsorbing member is shown generally as  222  in FIG.  6 . The hydrocarbon adsorbing member  222  includes folded portions  230   a ,  230   b  that extend along a portion of the circumferences of the outer cylinder and the inner cylinder, respectively. An intermediate member  228  is disposed between the inner cylinder and the outer cylinder. This embodiment is also assembled in a similar manner and operates similarly to the hydrocarbon adsorbing member  22 . 
   A fourth embodiment of a hydrocarbon adsorbing member is shown in  FIG. 7  generally as  322 . Hydrocarbon adsorbing member  322  has an intermediate portion  328  that includes a plurality of individual radially extending hydrocarbon adsorbing members  330  that are attached to the inner and outer cylinders. Hydrocarbon adsorbing member  322  may include a stiffening member  334  to provide increased structural rigidity to the structure. The stiffening member  334  may also be another cylindrical member thereby creating a cylinder-within-a-cylinder-within-a-cylinder design that may include any number of concentric or acentric cylinders, each separated by an intermediate member. 
   While the invention has been taught with specific reference to the above-described embodiments, one skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention. For example, not all of the parts need be manufactured from the hydrocarbon adsorbing material. Plastics, aluminum, stainless steel, and other materials can be used to provide the structures; however, obviously, if non-hydrocarbon adsorbing materials are used, the efficiency of the unit may be lessened. In addition, the flange need not be located at an end of the outer cylinder, but may be located anywhere along the length of the cylinder or more than one flange may be used. Also, a flange may be attached to the inner cylinder. 
   It would also be possible to manufacture the hydrocarbon adsorbing device with only one of either the inner or outer cylinders or multiple cylinders and intermediate members. Other shapes may also be substituted for the cylindrical shape, such as a square, rectangular or oval, or any shape that may match the cross section of the induction system. A housing may also be used to hold the hydrocarbon adsorbing member that allows air to pass along the outside of the outer cylinder to provide an even greater surface area for adsorbing hydrocarbons. It should also be realized that the intermediate member may include any number of folds and may be more or less than the folds depicted. Therefore, the described embodiments are to be considered in all respects only as illustrative and not restrictive, and the scope of the invention is indicated by the following claims rather than by the description.