Abstract:
There is provided an air cleaner in which an adsorption element for adsorbing vaporized fuel is surely fixed to a housing without additionally providing a special step, and moreover the performance of element and the performance of an air cleaner itself can be maintained, and a manufacturing method for the air cleaner. The air cleaner is configured so that a filter element and an adsorption element for adsorbing vaporized fuel are incorporated in a housing formed by joining the open ends of a pair of housing members to each other. At the open end of each of the housing members, a welding protrusion projecting toward the open end on the other side is formed, and a connecting portion formed with a welding protrusion is provided on a holding frame of the adsorption element.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an air cleaner that filters air flowing in an air intake system of an internal combustion engine and a method for manufacturing the same. 
     2. Description of the Related Art 
     In an internal combustion engine, evaporated fuel sometimes flows from the engine side into an air cleaner. In the conventional air cleaner, in order to adsorb the vaporized fuel, an adsorbent has been provided in the air cleaner in addition to a filter element. This adsorbent is preferably fixed in the air cleaner to prevent the adsorbent from being removed by the user. 
     As one example of such a technique, an air cleaner disclosed in Japanese Patent Laid-Open No. 2002-266713 is available. The air cleaner disclosed in this publication has a filter element provided so as to partition the interior of a housing into the clean side and the dust side. A plate-shaped adsorption element provided with an adsorbent is provided in parallel with the filter element. Also, on the inner surface of the housing, an inner flange projecting toward the center side so as to be parallel with the filter element is formed throughout the entire periphery. On one surface side of the inner flange, welding pins are formed. On the other hand, the adsorption element has a frame at the peripheral edge thereof. In this frame, insertion holes are formed at positions corresponding to the welding pins formed on the inner flange. 
     The adsorption element is attached to the housing by inserting the welding pins into the insertion holes formed in the frame of the adsorption element, collapsing the tip ends of the welding pins projecting from the surface of the frame by heating, and staking the frame by the welding pins. 
     However, in the technique disclosed in the aforementioned publication, it is necessary to provide a step of fixing the adsorption element. Moreover, since this step involves work in the housing, the step takes much time and effort. 
     In addition, in the attaching step, the adsorption element is adversely affected by heat for heating the pins, and also melt residues melting out from the tip ends of the pins at the time of heating may be generated. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide an air cleaner in which an adsorption element provided with an adsorbent is surely fixed to a housing without additionally providing a special step, and moreover the performance of element and the performance of an air cleaner itself can be maintained, and a manufacturing method for the air cleaner. 
     To achieve the above object, firstly, the present invention adopts an air cleaner described below. 
     In an air cleaner ( 1 ) including a housing ( 1 A), the housing ( 1 A) consisting of a pair of housing members ( 2 ,  20 ) each formed with an open end, and being configured so that the open ends are closed by being joined to each other; and a filter element ( 60 ) for filtering air taken into the housing ( 1 A), the filter element ( 60 ) being assembled so as to partition the interior of the housing ( 1 A) into regions of the housing members ( 2 ,  20 ), in the housing ( 1 A), an adsorption element ( 40 ) for adsorbing vaporized fuel flowing in from the engine side is further arranged on either one side of the housing members ( 2 ,  20 ) so as to face to the filter element ( 60 ), the adsorption element including an adsorbent ( 41 ) for adsorbing the vaporized fuel and a holding frame ( 42 ) for holding the outer peripheral edge of the adsorbent ( 41 ); at the open end of each of the housing members ( 2 ,  20 ), a welding protrusion ( 12 ,  29 ) which projects toward and abuts on the open end on the other side is provided; on the holding frame ( 42 ), a connecting portion ( 46 ) is provided in which a welding protrusion ( 47 ) abutting on the welding protrusion ( 29 ) of the housing member ( 20 ) on the reverse side to the side on which the adsorption element ( 40 ) is arranged via the filter element ( 60 ) is formed; and the welding protrusions ( 12 ,  29 ) of both of the housing members ( 2 ,  20 ) abut on each other, and the welding protrusion ( 47 ) formed in the connecting portion ( 46 ) abuts on the welding protrusion ( 29 ) of the housing member ( 20 ) located on the reverse side to the adsorption element ( 40 ), whereby the welding protrusions are vibration welded so that the housing ( 1 A) and the adsorption element ( 40 ) are formed integrally. 
     In the air cleaner ( 1 ) in accordance with the present invention, the welding protrusions ( 12 ,  29 ) of the housing members ( 2 ,  20 ) and the welding protrusion ( 47 ) of the adsorption element ( 40 ), which are welded and integrated, are formed so as to extend along the welding protrusions ( 12 ,  29 ,  47 ) with a predetermined distance being provided on the inside and the outside, and are surrounded by wall portions ( 11 ,  48 ) for preventing burrs produced by vibration welding of the welding protrusions ( 12 ,  29 ,  47 ) from scattering. 
     Also, in the air cleaner ( 1 ) in accordance with the present invention, at the open end of each of the housing members ( 2 ,  20 ), a flange portion ( 8 ,  26 ) is formed which projects to the outside and is lapped mutually, and the welding protrusion ( 12 ,  29 ) of each of the housing members ( 2 ,  20 ) is formed on the surface on which the flange portions ( 8 ,  26 ) face to each other. 
     In the above-described air cleaner ( 1 ), in either one of the flange portions ( 8 ,  26 ), an outside wall portion ( 11 ) is formed at a position separating a predetermined distance from the welding protrusions ( 12 ,  29 ,  47 ) on the outside of the welding protrusions ( 12 ,  29 ) of the housing members and the welding protrusion ( 47 ) of the adsorption element, which are welded and integrated, the outside wall portion ( 11 ) projecting toward the other flange portion ( 8 ,  26 ) and preventing burrs from scattering; on the holding frame ( 42 ) of the adsorption element ( 40 ), an inside wall portion ( 48 ) is formed at a position separating a predetermined distance from the welding protrusions ( 12 ,  29 ,  47 ) on the inside of the welding protrusions ( 12 ,  29 ) of the housing members and the welding protrusion ( 47 ) of the adsorption element, which are welded and integrated, the inside wall portion ( 48 ) projecting toward the flange portion ( 26 ) of the housing member ( 20 ) on the reverse side to the housing member ( 2 ) on which the adsorption element ( 40 ) is arranged, and preventing burrs produced by vibration welding of the welding protrusions ( 12 ,  29 ,  47 ) from scattering; and the outside wall portion ( 11 ) surrounds the outside of the welding protrusions, whereby a space is formed which is closed by the outside wall portion ( 11 ), the welding protrusions ( 12 ,  29 ,  47 ), and the flange portions ( 8 ,  26 ), and the inside wall portion ( 48 ) surrounds the inside of the welding protrusions, whereby a space is formed which is closed by the inside wall portion ( 48 ), the welding protrusions ( 12 ,  29 ,  47 ), the connecting portion ( 46 ) of the holding frame, and the flange portion ( 26 ). 
     Further, in the above-described air cleaner ( 1 ), in the vicinity of the open end of each of the housing members ( 2 ,  20 ), a projecting portion ( 5 ,  23 ) formed by projecting the peripheral wall surface ( 3 ,  21 ) of the housing member ( 2 ,  20 ) to the outside is formed, the projecting portion ( 5 ,  23 ) is formed by a horizontal surface ( 6 ,  24 ) extending from the peripheral wall surface ( 3 ,  21 ) toward the outside and a vertical surface ( 7 ,  25 ) extending toward the housing member ( 2 ,  20 ) on the other side at the outside edge of the horizontal surface ( 6 ,  24 ), and the projecting portions ( 5 ,  23 ) are combined and the interior there of is configured as an insertion portion in which the peripheral edge portion of the filter element ( 60 ) is inserted; the flange portion ( 8 ,  26 ) is formed at the tip end of the vertical surface ( 7 ,  25 ); the holding frame ( 42 ) of the adsorption element ( 40 ) is formed so that a bent surface ( 45 ) formed by bending the outer peripheral edge thereof is formed along the peripheral direction of the adsorption element ( 40 ) and is in close contact with the inner surface of the projecting portion ( 5 ,  23 ); and at the tip end of the bent surface ( 45 ), the connecting portion ( 46 ) which projects further outward and is formed with the welding protrusion ( 47 ) at the tip end thereof and the inside wall portion ( 48 ) which extends toward the flange portion ( 26 ) of the housing member ( 20 ) on the inside of the welding protrusion ( 29 ) of the housing member ( 20 ) on the reverse side to the side on which the adsorption element ( 40 ) is arranged are formed. 
     Also, in the above-described air cleaner ( 1 ) in accordance with the present invention, in the vicinity of the open end of each of the housing members ( 2 ,  20 ), a projecting portion ( 5 ,  23 ) formed by projecting the peripheral wall surface ( 3 ,  21 ) of the housing member ( 2 ,  20 ) to the outside is formed, the projecting portion ( 5 ,  23 ) is formed by a horizontal surface ( 6 ,  24 ) extending from the peripheral wall surface ( 3 ,  21 ) toward the outside and a vertical surface ( 7 ,  25 ) extending toward the housing member ( 2 ,  20 ) on the other side at the outside edge of the horizontal surface ( 6 ,  24 ), and the projecting portions ( 5 ,  23 ) are combined and the interior thereof is configured as an insertion portion in which the peripheral edge portion of the filter element ( 60 ) is inserted; the flange portion ( 8 ,  26 ) is formed at the tip end of the vertical surface ( 7 ,  25 ); the holding frame ( 42 ) of the adsorption element ( 40 ) is formed so that a bent surface ( 45 ) formed by bending the outer peripheral edge thereof is formed along the peripheral direction of the adsorption element ( 40 ) and is in close contact with the inner surface of the projecting portion ( 5 ); and at the tip end of the bent surface ( 45 ), the connecting portion ( 46 ) which projects further outward and is formed with the welding protrusion ( 47 ) at the tip end thereof and the inside wall portion ( 48 ) which extends toward the flange portion ( 26 ) of the housing member ( 20 ) on the inside of the welding protrusion ( 29 ) of the housing member ( 20 ) on the reverse side to the side on which the adsorption element ( 40 ) is arranged are formed. 
     In the present invention, in the housing member ( 102 ) in which the adsorption element ( 140 ) is arranged, a support member ( 180 ) which is lapped on the adsorption element ( 140 ) and supports the adsorbent ( 141 ) is provided so as to be located on the interior side of the adsorption element ( 140 ). 
     In this case, at a peripheral edge ( 181 ) of the support member ( 180 ), a welding protrusion ( 187 ) projecting toward the housing member ( 120 ) on the reverse side to the housing member ( 102 ) in which the support member ( 180 ) is arranged is formed, and the welding protrusion is configured by being held between the welding protrusion ( 112 ) formed on the housing member ( 102 ) in which the support member ( 180 ) is arranged and the welding protrusion ( 147 ) formed on the holding frame ( 142 ) of the adsorption element ( 140 ). 
     Also, to achieve the above-described object, secondly, the present invention adopts a manufacturing method for an air cleaner ( 1 ) described below. 
     In a manufacturing method for an air cleaner ( 1 ), including the steps of forming a housing ( 1 A) by joining open ends of a pair of housing members ( 2 ,  20 ) formed with the open end and by closing the open ends; attaching an adsorption element ( 40 ) into the housing ( 1 A), the adsorption element ( 40 ) including an adsorbent ( 41 ) for adsorbing vaporized fuel and a holding frame ( 42 ) for holding the outer peripheral edge of the adsorbent ( 41 ) to adsorb the vaporized fuel flowing in from the engine side; and assembling a filter element ( 60 ) for filtering air so as to partition the interior of the housing ( 1 A) into regions of the housing members ( 2 ,  20 ), at the open end, a welding protrusion ( 12 ,  29 ) that projects toward and abuts on the open end on the other side is provided, and further on the holding frame ( 42 ), a connecting portion ( 46 ) is provided in which a welding protrusion ( 47 ) abutting on the welding protrusion ( 12 ,  29 ) of the housing member ( 2 ,  20 ) is formed; in the housing forming step and the adsorption element attaching step, the adsorption element ( 40 ) is fitted in one of the housing members ( 2 ,  20 ) from the open end; the welding protrusion ( 12 ) of one housing member ( 2 ) in which the adsorption element ( 40 ) is fitted and the welding protrusion ( 47 ) of the adsorption element ( 40 ) is caused to abut on the welding protrusion ( 29 ) of the other housing member ( 20 ); and then, one housing member ( 2 ) in which the adsorption element ( 40 ) is fitted and the other housing member ( 20 ) are vibrated relatively in the direction in which both of the housing members ( 2 ,  20 ) slide while a force which presses the housing members ( 2 ,  20 ) against each other is applied, whereby the housing ( 1 A) and the adsorption element ( 40 ) are formed integrally by vibration welding at the same time. 
     In the above-described manufacturing method, in one housing member ( 102 ) in which the adsorption element ( 140 ) is fitted, a support member ( 180 ) for supporting the adsorbent ( 141 ) of the adsorption element ( 140 ) is located on the interior side of the adsorption element ( 140 ), and the adsorption element ( 140 ) and the support member ( 180 ) are lapped on each other and are fitted in one housing member ( 102 ); and a welding protrusion ( 187 ) which is formed at the peripheral edge of the support member ( 180 ) and extends toward the welding protrusion ( 129 ) of the other housing member ( 120 ) is held between the welding protrusion ( 112 ) of one housing member ( 102 ) and the welding protrusion ( 147 ) of the adsorption element ( 140 ), and in this state, the welding protrusion ( 112 ) of the one housing member ( 102 ), the welding protrusion ( 187 ) of the support member ( 180 ), and the welding protrusion ( 147 ) of the adsorption element ( 140 ) are caused to abut on the welding protrusion ( 129 ) of the other housing member ( 120 ), whereby these welding protrusions are vibration welded at the same time. 
     In the present invention, three members of the paired housing members and the adsorption element are welded in one step of the vibration welding step. Therefore, there is no need for separately providing a step for attaching the adsorption element to the housing members, so that an air cleaner provided with the adsorption element can be manufactured efficiently. Moreover, since the adsorption element is vibration welded to the housing, the construction can be made such that the adsorption element cannot be removed easily. 
     When vibration welding is performed, burrs are produced from the welding protrusions. In the present invention, the wall portions are formed on the inside and outside of the welding protrusion of the housing and the connecting portion of the adsorption element to confine burrs. Therefore, burrs do not intrude into the air cleaner, so that the adsorption element and the engine are not damaged. Therefore, the performance and quality of air cleaner can be maintained. 
     Further, by providing the support member, the adsorbent of the adsorption element can be prevented from being deflected to the downstream side of the flow of air. Since the deflection of adsorbent can be prevented by the provision of support member, the adsorbent can be formed so as to be thin. Further, since the adsorbent is thin, the airflow resistance of air passing through the adsorbent is reduced. Therefore, on the downstream side of the filter element, the adsorption element can be provided so as to cover the transverse section in the housing in almost the whole region. If the adsorption element is provided in such a manner, vaporized fuel flowing into the housing can be adsorbed surely, and therefore the vaporized fuel can be prevented effectively from leaking to the upstream side. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of an air cleaner; 
         FIG. 2  is a longitudinal sectional view showing a part of an air cleaner; 
         FIG. 3  is a perspective view of a holder; 
         FIG. 4  is a partial view showing the states of a first housing member, a second housing member, and an absorption element before they are vibration welded; 
         FIG. 5  is a partial view showing the states of a first housing member, a second housing member, and an absorption element after they have been vibration welded; 
         FIG. 6  is a perspective view of an air cleaner showing a state before a filter element is mounted in a completed housing; 
         FIG. 7  is a longitudinal sectional view of a part of an air cleaner formed with an outside wall portion and an inside wall portion in a different way from the air cleaner shown in  FIG. 2 ; 
         FIG. 8  is an exploded perspective view of an air cleaner in accordance with a second embodiment; and 
         FIG. 9  is a longitudinal sectional view of a part of an air cleaner. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the present invention will now be described with reference to the accompanied drawings. 
     First Embodiment 
       FIG. 1  is an exploded perspective view of an air cleaner  1  in accordance with a first embodiment of the present invention.  FIG. 2  is a longitudinal sectional view showing a part of the air cleaner  1 . 
     The air cleaner  1  includes a housing  1 A forming an outer shell and a filter element  60  stored in the housing  1 A to filter air flowing in the housing  1 A. Also, the air cleaner  1  is provided with a holder  70  for fixing the position of the filter element  60  stored in the housing  1 A with respect to the housing  1 A so that the holder  70  can be inserted in and drawn from the housing. Further, the air cleaner  1  is provided with an adsorption element  40  for adsorbing a vaporized fuel, which is evaporated and flows into the air cleaner  1  from the engine side, in the housing  1 A. 
     The housing  1 A is made up of a pair of housing members  2  and  20 . In  FIGS. 1 and 2 , the housing member arranged on the upper side is the first housing member  2  and forms the clean side of the air cleaner  1 , and the housing member arranged on the lower side is the second housing member  20  and forms the dust side thereof. That is to say, in the air cleaner  1 , air flows in from the second housing side on the lower side, and filtered air flows out from the first housing side on the upper side. 
     The first housing member  2  includes a peripheral wall surface  3  consisting of four surfaces and a top surface  4  closing the upper end thereof, and the lower surface thereof is open as an open end. On one surface  3   b  of the peripheral wall surface  3 , an outflow port  10  for allowing filtered air to flow out is formed. On the other hand, the second housing member  20  includes a peripheral wall surface  21  consisting of four surfaces and a bottom surface  22  closing the lower end thereof, and the upper end thereof is open as an open end. On one surface  21   b  of the peripheral wall surface  21 , an inflow port  27  for allowing air to flow in is formed. 
     The housing  1 A is configured so that the open end formed on the lower end of the first housing member  2  and the open end formed on the upper end of the second housing member  20  are lapped on each other, and these open ends are welded to each other in a state in which the open end of one housing member is closed by the other housing member. 
     In the vicinity of the open end forming the lower surface of the first housing member  2 , a projecting portion  5  that projects the peripheral wall surface  3  toward the outside is formed on three surfaces excluding one surface  3   a  of the four surfaces forming the peripheral wall surface  3 . The projecting portion  5  forms an insertion portion in which the peripheral edge of the filter element  60  is disposed, as explained in detail later. The projecting portion  5  is made up of a horizontal surface  6  projecting horizontally toward the outside at a position having a predetermined height from the lower end of the first housing member  2  and a vertical surface  7  that is bent toward the lower end side at the outer peripheral edge of the horizontal surface  6  and is formed so as to cover the outer periphery of the first housing member  2 . 
     In a portion in which the peripheral wall surface  3  of the first housing member  2  and the horizontal surface  6  intersect, a groove  13  having an L-shaped cross section is formed along a ridge line forming the top portion of inner surface. The groove  13  performs a function of confining burrs. 
     Further, at the lower end of the vertical surface  7 , a flange portion  8  projecting toward the outside is formed. On the lower surface of the flange portion  8 , namely, on the surface facing to the second housing member  20 , a welding protrusion  12  projecting toward the second housing member  20  is formed. 
     At the outer peripheral edge of the flange portion  8 , an outside wall portion  11  is formed over the three surfaces of the peripheral wall surface  3  on which the flange portion  8  is formed. The outside wall portion  11  is formed so as to surround the outside of the welding protrusion  12  with a predetermined distance being provided between the outside wall portion  11  and the welding protrusion  12 . The outside wall portion  11  also performs a function of confining burrs, as explained in detail later. 
     In contrast, in the vicinity of the open end of the remaining one surface, a concave portion  9  is formed in which a middle portion excluding both right and left side portions is depressed toward the upside from the lower end of the first housing member  2 . The concave portion  9  is formed as an opening  1 B for attaching and detaching the filter element  60 . 
     Similarly, in the vicinity of the open end forming the upper surface of the second housing member  20 , on the peripheral wall surface  21  corresponding to the projecting portion  5  of the first housing member  2 , a projecting portion  23  that projects the peripheral wall surface  21  toward the outside is formed. The projecting portion  23  is also made up of a horizontal surface  24  projecting horizontally toward the outside at a position that is lowered a predetermined dimension from the upper end of the second housing member  20  and a vertical surface  25  that is bent toward the upper end side at the outer peripheral edge of the horizontal surface  24  and is formed so as to cover the outer periphery of the second housing member  20 . 
     At the upper end of the vertical surface  24 , a flange portion  26  projecting toward the outside at the upper end of the vertical surface  25  is formed. In this flange portion  26  as well, a welding protrusion  29  projecting toward the first housing member  2  is formed on the surface facing to the flange portion  8  of the first housing member  2 . The welding protrusion  29  is caused to abut on and welded to the welding protrusion  12  formed on the first housing member  2 . As shown in  FIG. 2 , the lower end of the outside wall portion  11  formed in the first housing member  2  abuts on the outer peripheral edge of the flange portion  26 . The welding protrusion  29  of the second housing member  20  is formed so as to have a width that is about two times the width of the welding protrusion  12  of the first housing member  2  so that both of the welding protrusion  12  of the first housing member  2  and a welding protrusion  47  of the adsorption element  40 , described in detail later, abut on the tip end of the welding protrusion  29 . 
     In a surface  21   a  of the second housing member  20 , which surface  21   a  corresponds to the surface  3   a  formed with the concave portion  9  of the first housing member  2 , a concave portion is similarly formed in which a middle portion excluding both right and left side portions is depressed toward the downside from the upper end of the second housing member  20 . The concave portion  28  of the second housing member  20  is formed as the opening  1 B for attaching and detaching the filter element  60  together with the concave portion  9  of the first housing member  2 . 
     Further, the air cleaner  2  has the holder  70  shown in  FIG. 3 . The position of the holder  70  is fixed by pushing the filter element  60  stored in the housing  1 A against the housing  1 A. The holder  70  includes a lid portion  71  for closing the opening  1 B of the housing  1 A, a pair of wedge portions  72  that extend perpendicularly to the lid portion  71  and are inserted in the housing  1 A, and a connecting portion  74  for connecting both of the wedge portions  72  to each other on the tip end side of the wedge portions  72 . The lid portion  71  has a substantially rectangular shape capable of covering the whole of the opening  1 B of the housing  1 A. In each of the wedge portions  72 , a guide surface  73  that tilts so that the height thereof increases from the tip end toward the root is formed on the inner surface facing to each other. 
     The filter element  60  stored in the housing  1 A has a rectangular external shape, and includes a pleated filter medium  61  and a frame  62  for holding the outer peripheral edge of the filter medium  61 . On the outer peripheral surface of the frame  62  is mounted a seal packing  64  throughout the entire periphery. 
     The filter medium  61 , which is a member formed by laminating a nonwoven fabric etc., allows air flowing into the air cleaner  1  to pass through to filter the air. The frame  62  for holding the filter medium  61  is formed, for example, by injection molding a resin. The frame  62  is formed with a support leg  66  extending downward and a packing mounting flange  63  projecting to the outside from the outer peripheral surface. 
     The lower end of a portion forming the side of the support leg  66  tilts so that the height on the opening  1 B side of the portion is small and the height on the interior side thereof is large. The lower end of the portion forming the side of the support leg  66  is supported on the guide surface  73  provided on the wedge portion  77  of the holder  70 . 
     On the other hand, the packing mounting flange  63  is a portion on which the seal packing  64  is mounted. At the tip end of the packing mounting flange  63 , a stopper  65  projecting to the upside and the downside is formed to prevent the seal packing  64  attached to the packing mounting flange  63  from coming off. The frame  62  of this embodiment is provided with a rib  67  extending in the width direction in the center in the depth direction of the filter element  60 . However, this rib  67  is inessential and need not be especially provided. 
     The seal packing  64  is mounted on the frame  62  by inserting the packing mounting flange  63  in a mounting slit formed on the inside of the seal packing  64  and by bonding the seal packing  64  to the packing mounting flange  63  with an adhesive. In the upper part of the seal packing  64 , an interference  64   a  is formed, and a seal is provided by pressing the interference  64   a  against the first housing member  2  side. The seal packing  64  of this embodiment is inserted in the insertion portion of the housing  1 A, and the interference  64   a  is pressed against the first housing member  2  side, by which the seal packing  64  seals the joint portion between the first housing member  2  and the second housing member  20 . 
     That is to say, the wedge portion  72  of the holder  70  is provided with the tilting guide surface  73 , and on the other hand, the frame  62  of the filter element  60  is provided with the tilting support leg  66  at the lower end thereof. Therefore, when the holder  70  is inserted from the opening  1 B, the filter element  60  stored in the housing  1 A is pushed up by the guide surface  73 , and is gradually pressed against the first housing member  2  side. Thereby, the upper side of the sealing packing  64  is pressed against the back surface of a holding frame  42  of the adsorption element  40 . When the upper side of the sealing packing  64  is pressed against the back surface of the holding frame  42 , the interference  64   a  is crushed by the holding frame  42 , and thereby the clean side in the housing  1 A is sealed. At this time, in a state in which the holder  70  is completely inserted in the housing  1 A, the entire periphery of the seal packing  64  is pressed against the holding frame  42  uniformly by the tilt of the guide surface  73  and the tilt of the support leg  66  having a tilt reverse to the tilt of the guide surface  73 . 
     The adsorption element  40  that adsorbs vaporized fuel in the housing  1 A is made up of a rectangular adsorbent  41  whose inside is open, the holding frame  42  for holding the outer peripheral edge of the adsorbent  41 , and an inner frame  51  provided on the open inside of the adsorbent  41  to hold the adsorbent  41 . 
     The adsorbent  41 , which is formed of activated carbon or the like, adsorbs vaporized fuel flowing into the housing  1 A through the outflow port  10 . 
     The holding frame  42  is a member formed, for example, by injection molding a resin. In the center in the width direction of the holding frame  42 , a bent portion  43  is formed, and a bent surface  45  is formed, the bent surface  45  being bent downward so that the outer side of the bent portion  43  is at almost right angles to the inner side of the bent portion  43 . At the outer peripheral edge of the holding frame  42 , there are formed a connecting portion  46  projecting to the outside and an inside wall portion  48  projecting further downward. Further, at the tip end of the connecting portion  46 , the welding protrusion  47  projecting downward is formed along the peripheral direction of the holding frame  42 . However, as is apparent from  FIG. 1 , on one side corresponding to the opening  1 B of the housing  1 A, of four sides forming the holding frame  42 , the bent surface  45  is not formed, and a concave portion  42   a  having almost the same shape as that of the concave portion  9  formed in the first housing member is formed. 
     As shown in  FIG. 2 , a portion  44  on the inner side of the bent portion  43  is matched with the horizontal surface  6  forming the projecting portion  5  of the first housing member  2 , and the bent surface  45  is matched with the vertical surface  7 , by which the holding frame  42  is brought into close contact with the inner surface of the projecting portion  5 . 
     The welding protrusion  47  formed in the connecting portion  46  is vibration welded, together with the welding protrusion  12  formed in the flange portion  8  of the first housing member  2 , to the welding protrusion  29  formed in the flange portion  26  of the second housing member  20 . On the other hand, on the inside of the welding protrusion  29  formed on the second housing member  20 , the inside wall portion  48  is formed at a position separating a predetermined distance from the welding protrusion  29  so as to separate the interior of the housing  1 A from the portion in which the welding protrusion  29  is formed. By the inside wall portion  48 , the welding protrusion  29  of the second housing member  20 , the connecting portion  46  formed on the holding frame  42 , and the flange portion  26  of the second housing member  20 , a closed space B is formed. The inside wall portion  48  performs a function of confining burrs, and burrs produced at the time of vibration welding are accumulated in the space B. 
     On the other hand, at the inner edge of the holding frame  42 , a holding groove  50  is formed in the center in the thickness direction. The holding groove  50  accommodates the outer edge of the adsorbent  41  therein, and holds the outer peripheral edge of the adsorbent  41 . Also, at the inner edge of the holding frame  42 , a protrusion  49  projecting upward is formed. The protrusion  49  is formed along the inner edge of the holding frame  42 , and the height thereof is consistent with the depth of the groove  13  having an L-shaped cross section, which is formed in the inner surface of the first housing member  2 . When the adsorption element  40  is attached to the housing  1 A, the protrusion  49  performs a function of confining burrs together with the groove in the first housing member  2 . 
     In the air cleaner  1  configured as described above, on the outside of the welding protrusions  12 ,  29  and  47 , a closed space A is formed by the outside wall portion  11  functioning to confine burrs, the flange portion  8 , and the flange portion  26  of the second housing member, so that burrs produced at the time of vibration welding are accumulated in the space A. Also, on the inside of the welding protrusions  12 ,  29  and  47 , the closed space B is formed by the welding protrusions  12  and  47 , the inside wall portion  48  functioning to confine burrs, the connecting portion  46  of the holding frame  42 , and the flange portion  26  of the second housing member, so that burrs produced at the time of vibration welding are accumulated in the space B. 
     As shown in  FIG. 2 , the protrusion  49  formed at the inner edge of the holding frame  42  of the adsorption element  40  also performs a function of confining burrs. Specifically, even in the case where burrs pass through between the projecting portion  5  formed on the first housing member  2  and the holding frame  42  at the time of vibration welding, the protrusion  49  prevents burrs from intruding into the housing  1 A. The burrs having passed through are accumulated in a small space formed by the protrusion  49  and the groove  13  in the first housing member  2 . 
     The air cleaner  1  is manufactured as described below. 
     First, as shown in  FIG. 4 , the adsorption element  40  is fitted on the inside of the first housing member  2 . At this time, the bent potion  43  formed on the holding frame  42  of the adsorption element  40  is caused to coincide with the boundary between the horizontal surface  6  and the vertical surface  7  in the projecting portion  5  of the first housing member  2 , and the portion  44  on the inner side of the bent portion  43  is brought into close contact with the inner surface of the horizontal surface  6 , and the bent surface  45  is brought into close contact with the inner surface of the vertical surface  7 . 
     Next, the open end of the first housing member  2  and the open end of the second housing member  20  are lapped on each other, and each open end is closed by the other housing member  2 ,  20 . At this time, both of the tip end of the welding protrusion  12  formed in the flange portion  8  of the first housing member  2  and the tip end of the welding protrusion  47  formed in the connecting portion  46  of the holding frame  42  are caused to abut on the tip end of the welding protrusion  29  formed in the flange portion  26  of the second housing member  20 . 
     Next, a force for pressing both of the housing members  2  and  20  against each other to clamp both the members is applied to the housing members  2  and  20 . At the same time, the first housing member  2  in which the adsorption element  40  has been fitted and the second housing member  20  are vibrated so that both of the members slide in the horizontal direction. For example, the position of the first housing member  2  in which the adsorption element  40  has been fitted is fixed, and the second housing member  20  is vibrated with respect to the first housing member  2  and the adsorption element  40 . Thereby, frictional heat is generated between the welding protrusion  12  of the first housing member  2  and the welding protrusion  29  of the second housing member  20  and between the welding protrusion  47  of the holding frame  42  and the welding protrusion  29  of the second housing member  20 . The welding protrusions  12 ,  29  and  47  are heat welded by the frictional heat, and thereby the first housing member  2  and the second housing member  20  are integrated, and also the holding frame  42  of the adsorption element  40  and the second housing member  20  are integrated. 
     The step of vibration welding is carried out until the welding protrusions  12 ,  29  and  47  are melted appropriately, and thereby the tip end of the outside wall portion  11  and the tip end of the inside wall portion  48  abut on the flange portion  26  of the second housing member  20  as shown in  FIG. 5 . 
     When the welding protrusions  12 ,  29  and  47  are melted by the frictional heat, burrs are produced accordingly from the welding protrusions  12 ,  29  and  47 . However, the air cleaner  1  is provided with the inside wall portion  48  on the inside of the welding protrusion  12 . As described above, the inside wall portion  48  separates the position at which the welding protrusion  12  is provided from the interior of the housing  1 A, so that the inside wall portion  48  performs a function of confining burrs. Therefore, the burrs produced at the time of vibration welding are prevented from scattering in the housing  1 A by the inside wall portion  48 . The burrs produced are accumulated in the space B. Similarly, the outside wall portion  11  provided on the outer side of the welding protrusion  12  also performs a function of confining burrs, and prevents the burrs produced at the time of vibration welding from scattering to the outside of the housing  1 A. The burrs produced are accumulated in the space A. 
     As described above, when the first housing member  2 , the second housing member  20 , and the adsorption element  40  are integrated by vibration welding, the housing  1 A is completed in which the opening  1 B is formed in one surface  3   a ,  21   a  of the four peripheral wall surfaces  3 ,  21 . Then, the filter element  60  is stored in the housing  1 A from the opening  1 B, and subsequently the holder  70  is inserted through the opening  1 B in the same way. When the holder  70  is inserted, the filter element  60  is pushed up gradually to the first housing member  2  on the upper side by the guide surfaces  73  formed on the inner surfaces of the wedge portions  72  of the holder  70 . 
     As described above, the guide surface  73  formed in the wedge portion  72  of the holder  70  is formed so that the opening  1 B side is high, and tilts downward slantwise toward the tip end. On the other hand, the support leg  66  formed on the frame  62  of the filter element  60  is formed so that the height on the interior side thereof is large and the height on the opening  1 B side is small. That is to say, the directions of tilts of the guide surface  73  and the support leg  66  are reverse to each other. Therefore, when the holder  70  is inserted completely, the seal packing  64  provided around the filter element  60  is pushed against the back surface of the holding frame  42  of the adsorption element  40  by a force that is uniform throughout the entire periphery. 
     On the other hand, the lid portion  71  of the holder  70  closes the opening  1 B. Thereby, the air cleaner  1  is completed. In this embodiment, both of the inside wall portion  48  and the outside wall portion  11  are provided on the first housing member  2 . However, the configuration is not limited to this one. 
       FIG. 7  shows the air cleaner  1  in accordance with an embodiment different from the embodiment shown in  FIG. 2 . In the air cleaner  1  shown in  FIG. 7 , the outside wall portion  11  is provided in the outer edge portion of the flange portion of the second housing member  20 , and the tip end thereof is formed so as to extend to the flange portion of the first housing member  2 . Also, the inside wall portion  48  is provided in the inner edge portion of the flange portion of the second housing member  20 , and the tip end thereof is formed so as to abut on the holding frame  42  of the adsorption element  40 . 
     Even if the wall portions  11  and  48  are provided on the outer side and the inner side of the welding protrusions  12 ,  29  and  47 , respectively, in this manner, the wall portions  11  and  48  perform a function of confining burrs, and surely prevent the burrs produced at the time of vibration welding from scattering to the inside and outside of the housing  1 A. 
     Second Embodiment 
       FIGS. 8 and 9  show an air cleaner  100  in accordance with a second embodiment of the present invention. 
     The air cleaner  100  in accordance with this embodiment has a support member  180  for preventing an adsorption element  140  from deflecting. 
       FIG. 8  is an exploded perspective view of the air cleaner  100 . The air cleaner  100  has a housing  101  forming an outer shell and a filter element  160  stored in the housing  101 . The housing  101  is configured by joining a first housing member  102  forming the upper part of the housing  101  and a second housing member  120  forming the lower part thereof. The first housing member  102  includes a peripheral wall surface  103  and a top surface  104 , and the lower part thereof is open. Also, the second housing member  120  includes a peripheral wall surface  121  and a bottom surface  122 . In this air cleaner  100  as well, the upper side of the housing  101 , formed by the first housing member  102 , is the clean side, and the lower side of the housing  101 , formed by the second housing member  120 , is the dust side. Also, in the peripheral wall surface  103  of the first housing member  102 , an outflow port  110  is provided, and in the peripheral wall surface  121  of the second housing member  120 , an inflow port  127  is provided. Further, in the joint portion between the first housing member  102  and the second housing member  120 , an opening  100 B is formed in one surface of the peripheral wall surfaces  103  and  121  of the housing  101 . The opening  100 B is used to insert the filter element  160  into the housing  101 . 
     The filter element  160  includes a frame  162  forming the peripheral edge portion thereof and a pleated filter medium  161  arranged on the inside of the frame  162 . Also, on the outer surface of the frame  162  is mounted a packing  163  throughout the entire periphery. As in the air cleaner  100  of the first embodiment, the filter element  160  is configured so as to be inserted from the opening  100 B by the holder  170  and is stored in the housing  101 . The construction of the holder  170 , the procedure for inserting the filter element  160  into the housing  101  by using the holder  170 , and the like are the same as those in the air cleaner  100  in accordance with the first embodiment, so that the explanation thereof is omitted here. Also, the second embodiment is the same as the first embodiment in that the filter element  160  is held in the housing  101  by utilizing wedge portions  172  of the holder and that a lid portion  171  closes the opening  100 B. The filter element  160  is not provided with a rib on the inside of the frame  162 . However, the rib may be provided as in the case of the first embodiment. 
     In the first housing member  102  forming the clean side, the adsorption element  140  and the support member  180  are provided in such a manner as to be lapped on each other. The adsorption element  140  is made up of a holding frame  142  forming the peripheral edge thereof and an adsorbing portion  141  that is arranged on the inside of the holding frame  142  and is held by the holding member  142 . The adsorbing portion  141  is configured so as to close the entire surface on the inside of the holding frame  142 , and no opening is formed in the central portion of the adsorbing portion  141 . On the other hand, the support member  180  is made up of a frame portion  181  forming the peripheral edge portion and a plurality of ribs  182  extending in the longitudinal and transverse directions on the inside of the frame portion  181 . The support member  180  is configured so that the ribs  182  support the adsorbing portion  141  by lapping the support member  180  on the adsorption element  140  to prevent the adsorbing portion  141  from being deflected to the downstream side by the flow of air. 
     In the air cleaner  100 , four members of the first and second housing members  102  and  120 , the adsorption element  140 , and the support member  180  are integrated by vibration welding.  FIG. 9  shows the details of the joint portion between the first and second housing members  102  and  120 , which is a portion in which the four members are vibration welded. 
     At the peripheral edge of the second housing member  120  is formed a flange portion  126  projecting to the outside, and on the upper surface thereof is formed a welding protrusion  129  projecting upward. The flange portion  126  is formed on three surfaces excluding the surface in which the aforementioned opening  100 B is formed, of the peripheral edges of the second housing member  120 . The welding protrusion  129  is formed over the total length of the flange portion  126 . 
     On the other hand, in the first housing member  102  forming the upper part of the housing  101 , the support member  180  and the adsorption element  140  are arranged by being lapped on each other with the support member  180  being positioned on the interior side of the first housing member  102 . In the vicinity of the open end of the first housing member  102  as well, on three surfaces of the peripheral wall surface  103 , a projecting portion  105  projecting outward is formed. This projecting portion  105  is also made up of a horizontal surface  106  projecting horizontally and a vertical surface  107  extending downward at the outer peripheral edge of the horizontal surface  106 . Further, at the lower end of the vertical surface  107 , a flange portion  108  projecting outward is formed. 
     On the lower surface of the flange portion  108 , a welding protrusion  112  projecting toward the second housing member  120  is formed. Also, at the outer peripheral edge of the flange portion  108 , an outside wall portion  111  is formed so as to surround the outside of the welding protrusions  112  and  129  with a predetermined distance being provided between the outside wall portion  111  and the welding protrusions  112  and  129 . The tip end of the outside wall portion  111  abuts on the flange portion  126  of the second housing member  120 , by which a closed space A is formed between the outside wall portion  111  and the welding protrusions  112  and  129 . Therefore, the outside wall portion  111  also performs a function of confining burrs when vibration welding is performed. 
     The adsorption element  140  and the support member  180  are arranged so as to be fitted on the inside of the projecting portion  105  of the first housing member  102 . Both of the frame portion  181  forming the peripheral edge of the support member  180  and the holding frame  142  of the adsorption element  140  are formed with bent portions  143  and  183 , respectively, in an intermediate portion in the width direction thereof, so that outer edges  145  and  185  are directed to the flange portion  126  of the second housing member  120 . The support member  180  and the adsorption element  140  are arranged on the inside of the projecting portion  105  so that the bent portions thereof coincide with a bent portion  109  that is a boundary line between the horizontal surface  106  and the vertical surface  107  in the projecting portion  105 . 
     The outer peripheral edge of the frame portion  181  of the support member  180  projects outward along the flange portion  108 , and at the tip end thereof, a welding protrusion  187  projects toward the welding protrusion  129  of the second housing member  120 . The outer surface of the welding protrusion  187  is in close contact with the inner surface of the welding protrusion  112  formed on the first housing member  102 . On the other hand, the outer peripheral edge of the holding frame  142  of the adsorption element  140  is forked into two parts; the outside is formed as a welding protrusion  147 , and the inside is formed as an inside wall portion  148 . Explaining in more detail, the outside part projects outward, and the tip end thereof is formed with the welding protrusion  147  projecting toward the welding protrusion  129  of the second housing member  120 . The outer surface of the outside part is in close contact with the inner surface of the support member  180 . On the other hand, at the tip end of the holding frame  142 , a part on the inner side of the inside part projects toward a portion on the inside of the welding protrusion  129  in the flange portion of the second housing member  120 . This projecting part is the inside wall portion  148 . The inside wall portion  148  is also formed so as to be parallel with the welding protrusions  129  and  147  with a fixed distance being provided between the inside wall portion  148  and the welding protrusions  129  and  147 . The inside wall portion  148  forms a space B together with the welding protrusions  129  and  147 , and performs a function of confining burrs when vibration welding is performed. 
     Thus, in the joint portion between the first housing member  102  and the second housing member  120 , the welding protrusion  112  of the first housing member  102 , the welding protrusion  187  of the support member  180 , and the welding protrusion  147  of the adsorption element  140  project toward the welding protrusion  129  of the second housing member  120  in a lapped state in the named order from the outside of the housing  101 . Also, on the outside of the welding protrusion  112  of the first housing element  102 , the outside wall portion  111  is provided, and on the inside of the welding protrusion  147  of the adsorption element  140 , the inside wall portion  148  is provided. The welding protrusions  112 ,  129 ,  147  and  187  are surrounded by the outside wall portion  111  and the inside wall portion  148 . Therefore, the burrs produced at the time of vibration welding remain in the spaces A and B formed between the outside wall portion  111  and the inside wall portion  148 , and thereby the burrs are surely prevented from scattering. As is apparent from  FIG. 9 , the thickness dimension of the welding protrusion  129  of the second housing member  120  is approximately equal to a sum of thickness dimensions of the welding protrusions  112 ,  148  and  187  formed on the first housing member  102 , the support member  180 , and the adsorption element  140 , respectively. 
     In the air cleaner  100  of this embodiment, as indicated by an encircled portion X, on the upper surface of the inner edge portion of the frame portion  181  of the support member  180 , a protrusion  188  projecting toward the inner surface of the first housing member  102  is formed along the inner edge portion of the frame portion  181 . On the other hand, on the inner surface of the first housing member  102 , a groove is formed at a position corresponding to the protrusion  188 . The upper end of the protrusion  188  abuts on the inner surface of the first housing member  102  at the position of this groove. Therefore, a space C is formed by the protrusion, the upper surface of the frame portion  181 , and the inner surface of the groove. Similarly, in the inner edge portion of the holding frame  142  of the adsorption element  140 , a protrusion  149  projects toward the frame portion  181  of the support member  180 . Therefore, a space D is formed on the inside surrounded by the protrusion  149 , the holding frame  142  of the adsorption element  140 , and the support member  180 . 
     These spaces C and D perform a function of confining burrs so that even if the burrs produced at the time of vibration welding pass between the first housing member  102  and the support member  180  and between the support member  180  and the adsorption element  140 , the burrs are prevented from intruding into the housing  101 . 
     According to the air cleaner  100  configured as described above, when air is sucked, the air having passed through the filter element  160  successively passes through the adsorbing portion  141  of the adsorption element  140 . At this time, by the pressure of air, the adsorbing portion  141  is subjected to a force for pushing away the adsorbing portion  141  toward the first housing member  102  on the upper side. However, since the ribs  182  of the support member  180  supports the adsorbing portion  141 , the adsorbing portion  141  is effectively prevented from deflecting greatly to the first housing member  102  side. 
     When the engine is stopped, the vaporized fuel flowing into the housing  101  from the engine side is adsorbed by the adsorbing portion  141  of the adsorption element  140 , and thereby the vaporized fuel is prevented from leaking further to the upstream side. In particular, in the air cleaner  100  in accordance with the second embodiment, since the adsorbing portion  141  covers the whole surface, the vaporized fuel having flown into the housing  101  cannot move further to the upstream side unless it passes through the adsorbing portion  141 . Therefore, the adsorbing portion  141  surely adsorbs vaporized fuel. 
     The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.