Patent Publication Number: US-2022228705-A1

Title: Accessory Component Mounting Structure for Canister

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a 35 U.S.C. § 371 US National Stage Entry application claiming priority to PCT Patent Application No. PCT/JP2020/024073 filed Jun. 19, 2020, which claims priority to Japanese Patent Application No. 2019-116346, filed Jun. 24, 2019, each of which is hereby incorporated herein by reference in its entirety for all purposes. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     TECHNICAL FIELD 
     The present disclosure relates generally to an accessory component mounting structure for a canister. 
     BACKGROUND 
     Conventionally, an accessory component mounting structure may be provided for a canister, for example, as described in Japanese Laid-Open Patent Publication No. 2010-106712. The mounting structure includes a cylindrical component mounting portion provided in the canister and an accessory component having a heat-generating portion that generates heat. The accessory component inserted into the internal space of the component mounting portion is mounted by snap-fitting. The accessory component is provided with a projection that is in contact with the side wall of the component mounting portion to suppress rattling. The accessory component has a built-in motor that generates heat, which may accumulate in the internal space of the component mounting portion of the canister. 
     SUMMARY 
     Embodiments described herein are directed to devices and methods to suppress heat generated by the heat-generating portion of the accessory component from accumulating in the internal space of the component mounting portion of the canister. 
     According to one aspect of the present disclosure, an accessory component mounting structure for a canister includes a tubular component mounting portion provided in the canister and an accessory component having a heat-generating portion. The accessory component is inserted into the internal space of the component mounting portion and is mounted by snap-fitting. A gap passage communicating an opening side of the component mounting portion with the rear side thereof is formed between the component mounting portion and the accessory component. A communication hole communicating the gap passage to the outside is formed in the component mounting portion. 
     According to the above aspect, the gap passage communicating with the outside via the communication hole is formed between the component mounting portion and the accessory component. Therefore, air may pass through the gap passage to aid in dissipating heat accumulated in the gap passage. As a result, it is possible to suppress the heat generated by the heat-generating portion of the accessory component from accumulating in the internal space of the component mounting portion of the canister. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a canister and a purge pump mounted to the canister according to an embodiment. 
         FIG. 2  is an enlarged front view of the purge pump mounted to the canister. 
         FIG. 3  is a cross-sectional view of the canister and purge pump of  FIG. 1  taken along line III-III of  FIG. 2 . 
         FIG. 4  is a cross-sectional view of the canister and purge pump of HG,  1  taken along line IV-IV of  FIG. 2 . 
         FIG. 5  is a perspective view of a pump mounting portion of the canister of FIG. 
         FIG. 6  is an exploded view of the canister and the purge pump of  FIG. 1 . 
         FIG. 7  is a front view of the purge pump of  FIG. 1 . 
         FIG. 8  is a left side view of the purge pump of  FIG. 1 . 
         FIG. 9  is a right side view of the purge pump of  FIG. 1 . 
         FIG. 10  is a plan view of the purge pump of  FIG. 1 . 
         FIG. 11  is a rear view of the purge pump of  FIG. 1 . 
         FIG. 12  is a bottom view of the purge pump of  FIG. 1 . 
         FIG. 13  is a front view of the pump mounting portion of the canister of  FIG. 1 . 
         FIG. 14  is a cross-sectional view of the pump mounting portion of the canister of  FIG. 1  taken along line XIV-XIV of  FIG. 13 , 
         FIG. 15  is a cross-sectional view of the pump mounting portion of the canister of  FIG. 1  taken along line XV-XV of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an embodiment of the present disclosure will be described with reference to the figures. In the present embodiment, a structure for mounting a purge pump as an accessory component to a canister will be described. 
     In a vehicle, such as an automobile, a canister filled with an adsorbent for adsorbing and desorbing fuel vapor is provided to prevent the fuel vapor generated in the fuel tank from being discharged into the atmosphere. The canister allows the adsorbent to adsorb the fuel vapor generated while the internal combustion engine (engine) is stopped. When the engine is driven, the fuel vapor is desorbed (purged) from the adsorbent by utilizing the intake negative pressure of the engine, and the desorbed fuel vapor is communicated to and combusted by the engine. 
       FIG. 1  is a perspective view of an embodiment of a canister  10  to which a purge pump  50  is mounted.  FIG. 2  is a front view of the purge pump mounted to the canister.  FIG. 3  is a cross-sectional view taken along line III-III of  FIG. 2 .  FIG. 4  is a cross-sectional view taken along line IV-IV of  FIG. 2 .  FIG. 5  is a perspective view of a pump mounting portion of the canister. Directions are discussed with reference to the arrows in each figure. In the present embodiment, the up-down direction corresponds to the up-down direction of the vehicle. The front-rear direction corresponds to the front-rear direction of the vehicle. The arrangement direction of the canister may be changed as appropriate. 
     As shown in  FIG. 1 , canister  10  includes an outer canister case  12  formed in a substantially cuboid shape with a relatively low height (in the up-down direction) as compared to its length and width in the front-rear and left-right directions, respectively. The canister case  12  is hollow and made of resin. An adsorbent configured to adsorb and desorb fuel vapor is provided in the internal space of the canister case  12 . For example, granular activated carbon may be used as the adsorbent. The granular activated carbon may be, for example, crushed activated carbon (crushed charcoal) and/or granulated charcoal. Powdered activated carbon may be made into a granular form using a binder, thereby forming the granular activated carbon. 
     At the center of the front side of the canister case  12 , a tank port  14  projects forward and is in fluid communication with the internal space of the canister case  12 . At the right end of the front side of the canister case  12 , an atmospheric port  16  projects forward and is in fluid communication with the internal space of the canister case  12 . A fuel vapor passage connected to the fuel tank is connected to the tank port  14 . An atmospheric passage opened to the atmosphere is connected to the atmospheric port  16 . 
     A pump mounting portion  20 , which has a tubular shape and an opening in its front surface, is formed at a front portion on the left side of the canister case  12 . A purge pump  50  is received in the pump mounting portion  20  (see  FIG. 1  to  FIG. 4 ). As shown in  FIG. 4 , the purge pump  50  includes a suction port  56  and a discharge port  58 . In the internal space of the pump mounting portion  20 , a purge port  18  in fluid communication with the internal space of the canister case  12  project forwards. The suction port  56  of the purge pump  50  is connected to the purge port  18 . The discharge port  58  of the purge pump  50  is connected to a purge passage in fluid communication with the intake passage of the engine. The pump mounting portion  20  and the purge pump  50  will be described in more detail below. 
     While the engine is stopped, fuel vapor in the fuel tank is guided, via the tank port  14 , to the internal space of the canister  10 . The fuel vapor is then adsorbed by the adsorbent. During the operation of the engine, the fuel vapor is desorbed from the adsorbent via the air flowing into the internal space of the canister  10  from the atmospheric port  16 . Then, the fuel vapor is forcibly purged to the intake passage of the engine by the purge pump  50 . 
       FIG. 6  is an exploded view of the canister  10  and the purge pump  50 .  FIG. 7  is a front view,  FIG. 8  is a left side view,  FIG. 9  is a right side view,  FIG. 10  is a plan view,  FIG. 11  is a rear view, and  FIG. 12  is a bottom view of the purge pump  50 . As shown in  FIG. 6 , the purge pump  50  may include a pump unit  52  and a motor unit  60 . The motor unit  60  drive the pump unit  52 . 
     The motor unit  60  includes an electric motor. The motor unit  60  generates heat due to operation of the electric motor. Accordingly, the motor unit  60  may also be referred to herein as a “heat-generating portion.” The motor unit  60  includes a substantially cylindrical outer motor housing  62 . The motor housing  62  includes a left end surface  62   a  and an outer peripheral surface  62   b.    
     A flange  64  extends outward from the motor housing  62  and is positioned at one end (e.g., the right end) in the axial direction of the motor housing  62 . As shown in  FIG. 8 , the flange  64  has a shape similar to an octagon in a side view. A lower surface  64   b  and a front surface  64   c  of the flange  64   g  intersect and are oriented perpendicular to each other. The flange  64  may have a substantially heptagon shape. The flange  64  has an upper surface  64   a  and the lower surface  64   b  that are oriented parallel to each other. An electric connector  66  projects forward from an upper end of a front surface  64   c  (see  FIG. 10 ). The electric connector  66  connects to an external connector for supplying power to the motor unit  60 . 
     Engagement projections  68  extend up-and-down symmetrically on the upper surface  64   a  and the lower surface  64   b  of the flange  64  (see  FIGS. 6, 7, 9 and 10 ). Each engagement projection  68  has a right-angled triangular prism shape. Each engagement projection  68  has a slope facing obliquely rearward and extending in the left-right direction. 
     As shown in  FIG. 7 , the pump unit  52  includes a pump housing  54  with a short cylindrical shape. The pump unit  52  also includes an impeller  55 , which is accommodated in the internal space of the pump housing  54  and rotatable about its central axis (see  FIG. 9 ). The pump housing  54  is concentrically disposed on the right side of the flange  64  of the motor unit  60 . The pump housing  54  has an outer diameter larger than the outer diameter of the motor housing  62  of the motor unit  60  and smaller than the outer diameter of the flange  64 . The pump housing  54  has a right end surface  54   a  and an outer peripheral surface  54   b.    
     As shown in  FIG. 9 , a front surface  54   c  and a lower surface  54   d , which are oriented perpendicular to each other, are formed at the front lower corner of the outer peripheral surface  54   b  of the pump housing  54 . The front surface  54   c  extends tangentially downward from the front end of the outer peripheral surface  54   b . The lower surface  54   d  extends tangentially forward from the lower end of the outer peripheral surface  54   b.    
     The suction port  56 , which has a cylindrical shape and projects rearward, is provided at the right end surface  54   a  of the pump housing  54 , so as to extend rearward from its axial center (see  FIGS. 10 to 12 ). The discharge port  58 , which has a cylindrical shape and extends forward, is provided at the lower end of the front surface  54   c  (see  FIG. 7 ). The suction port  56  and the discharge port  58  are in fluid communication with the internal space of the pump housing  54 . The impeller  55  is connected to an output shaft provided in the motor unit  60 . 
     When power is supplied to the motor unit  60  of the purge pump  50 , the motor unit  60  is driven, thereby rotating the impeller  55  of the pump unit  52 . As a result, the purge gas in the canister  10  is sucked through the suction port  56  of the pump unit  52  and pressurized, and then discharged from the discharge port  58 . The purge gas discharged from the discharge port  58  is pumped to the intake passage of the engine via the purge passage. 
       FIG. 13  is a front view of the pump mounting portion  20  of the canister  10 .  FIG. 14  is a cross-sectional view taken along line XIV-XIV of  FIG. 13 .  FIG. 15  is a cross-sectional view taken along line XV-XV of  FIG. 13 . As shown in  FIG. 14 , the pump mounting portion  20  includes a corner wall portion  22  with a square tubular shape. The pump mounting portion  20  also includes a rear wall  28  that closes the rear end surface of the corner wall portion  22  (see  FIG. 15 ). The rear wall  28  also serves as a partition wall that partitions the internal space of the corner wall portion  22  and the internal space of the canister case  12  in front and rear direction. 
     As shown in  FIG. 13 , the purge port  18  is disposed at a position right of the central portion of the rear wall  28 . The purge port  18  has a stepped cylindrical shape protruding forward from the rear wall  28  (see  FIGS. 14 and 15 ). The suction port  56  of the purge pump  50  connects to the purge port  18  by insertion (see  FIGS. 3 and 4 ). 
     As shown in  FIG. 13 , the corner wall portion  22  may have a left side wall  23 , a right side wall  24 , an upper side wall  25 , and a lower side wall  26 . The pump mounting portion  20  may also be referred to herein as a “component mounting portion.” The right side wall  24  also serves as a partition wall that partitions the internal space of the corner wall portion  22  and the internal space of the canister case  12  in right and left direction (see  FIG. 15 ). The upper side wall  25  is formed so as to be substantially in the same plane as an upper wall  12   b  of the canister case  12  (see  FIG. 6 ). The left side wall  23 , the right side wall  24 , the upper side wall  25 , and the lower side wall  26  may also be referred to herein as the “side wall.” 
     As shown in  FIG. 15 , the left side wall  23  of the corner wall portion  22  is disposed at a position shifted more leftward than a left side wall  12   a  of the canister case  12 . Consequently, the left end  28   a  of the rear wall  28  extends leftward and is exposed to the outside (see  FIG. 5 ). As shown in  FIG. 14 , the lower side wall  26  of the corner wall portion  22  is disposed at a position shifted more downward than a lower wall  12   c  of the canister case  12 . Consequently, the lower end  28   b  of the rear wall  28  extends downward and is exposed to the outside (see  FIG. 5 ). The left side wall  23 , the upper side wall  25 , the lower side wall  26 , the left end  28   a  of the rear wall  28 , and the lower end  28   b  of the rear wall  28  may also be referred to herein as the “wall exposed to the outside.” 
     As shown in  FIG. 6 , an elastic engaging piece  30 , which has a strip-plate shape, is positioned at the front end of the center, in the left-right direction, of the upper side wall  25 . The elastic engaging piece  30  is formed by a U-shaped cutout opening  32  in the upper side wall  25 , so as to surround the elastic engaging piece  30 . As a result, the front end of the elastic engaging piece  30  has a fixed end and a free end. The elastic engaging piece  30  is configured to be elastically deformed in the vertical direction (see the two-dot chain line  30  in  FIG. 14 ). An engaging hole  34 , which has a square shape is formed in the center of the elastic engaging piece  30 . 
     Another elastic engaging piece  30  (the same reference number), which is opposed and symmetrical with the elastic engaging piece  30  of the upper side wall  25  in the up-and-down direction, is formed on the lower side wall  26 . Engaging holes  34  of the elastic engaging pieces  30  are positioned such that both engagement projections  68  of the purge pump  50  simultaneously engages holes  34  when the purge pump  50  is sufficiently inserted into the pump mounting portion  20  is completed (see  FIG. 3 ). 
     As shown in  FIG. 13 , upper and lower left projections  40 , which are parallel to each other, extends from the inner surfaces of the left side wall  23 . Upper and lower right projections  41 , which are parallel to each other, extend from the inner surface of the right side wall  24 . Both left projections  40  and both right projections  41  may be disposed so as to face each other. 
     An upper left projection  42  and an upper right projection  43 , which are parallel to each other, extend from the inner surface of the upper side wall  25 . A lower left projection  44  and a lower right projection  45 , which are parallel to each other, extend from the inner surface of the lower side wall  26 . The upper left projection  42  and the lower left projection  44  are disposed opposite to each other. The upper right projection  43  and the lower right projection  45  are disposed opposite to each other. The left projections  40 , the right projections  41 , the upper left projection  42 , the upper right projection  43 , the lower left projection  44 , and the lower right projection  45  each has a linear and rib shape. These projections  40 - 45  also extend in the axial direction of the corner wall portion  22 , that is, in the front-rear direction. The left projections  40 , the right projections  41 , the upper left projection  42 , the upper right projection  43 , the lower left projection  44 , and the lower right projection  45  may each also be referred to herein as the “supporting projection.” 
     As shown in  FIG. 6 , a reinforcing flange or rib  47  extends over the entire circumference of the outer peripheral portion of the open end of the corner wall portion  22 . The reinforcing rib  47  may also be referred to herein as a “first reinforcing rill” A reinforcing flange or rib  48  is provided at the center of the corner wall portion  22  in the front-rear direction. The reinforcing rib  48  extend over the outer periphery of the left side wall  23 , the upper side wall  25 , and the lower side wall  26  and has a general C-shape. The reinforcing rib  48  is positioned so as to cross the vicinity of the rear of both the elastic engaging pieces  30 . The reinforcing rib  48  may also be referred to herein as a “second reinforcing rib.” The second reinforcing rib  48  extends over the entire circumference of the corner wall portion  22 . 
     A communication slot or hole  70  extends through the rear end of the left side wall  23 . The communication hole  70  has a long narrow shape oriented in the up-down direction. The communication hole  70  penetrates the left side wall  23  in the wall thickness direction, that is, the left-right direction (see  FIG. 15 ). The communication hole  70  may also be referred to herein as a “first communication hole.” 
     As shown in  FIG. 5 , a communication slot or hole  72  extends through the left end  28   a  of the rear wall  28 . The communication hole  72  has a long narrow shape oriented in the up-down direction. The communication hole  72  penetrates the rear wall  28  in the wall thickness direction, that is, the front-rear direction (see  FIG. 15 ). The communication hole  72  may also be referred to herein as a “second communication hole.” 
     As shown in  FIG. 6 , the purge pump  50  is inserted into the pump mounting portion  20  of the canister  10  from the front (specifically, by press-fitting in this embodiment). The purge pump  50  is inserted with the suction port  56  facing backward and the motor housing  62  facing left. 
     In the process of inserting the purge pump  50  into the pump mounting portion  20 , the left end surface  62   a  of the motor housing  62  of the purge pump  50  is in sliding contact with both the left projections  40  of the corner wall portion  22 . The upper and lower ends of the outer peripheral surface  62   b  of the motor housing  62  are in sliding contact with the upper left projection  42  and the lower left projection  44  of the corner wall portion  22 . Further, the right end surface  54   a  of the pump housing  54  of the purge pump  50  is in sliding contact with both right projections  41  of the corner wall portion  22 . The upper end of the outer peripheral surface  54   b  of the pump housing  54  is in sliding contact with the upper right projection  43  of the corner wall portion  22 . The lower surface  54   d  of the pump housing  54  is in sliding contact with the lower right projection  45  of the corner wall portion  22 . As a result, the purge pump  50  is positioned by press fitting and is positioned with respect to the radial direction of the corner wall portion  22 . In addition, the suction port  56  is disposed concentrically with and oppositely to the purge port  18 . 
     Further, when the purge pump  50  is pushed in, the suction port  56  is simultaneously inserted into the purge port  18  to complete the connection (see  FIGS. 2 to 4 ). Both elastic engaging pieces  30  of the corner wall portion  22  are bent and elastically deformed in the expanding direction by both engagement projections  68  of the purge pump  50 . Thereafter, both elastic engaging pieces  30  are elastically restored simultaneously or substantially simultaneously with the completion of the connection of the suction port  56  with the purge port  18 . Thus, both engaging holes  34  are engaged with both engagement projections  68  (see  FIG. 3 ). As a result, the purge pump  50  is prevented from disengaging the pump mounting portion  20 , thereby mounting of the purge pump  50  to the canister  10  by snap-fitting (see  FIG. 1 ). 
     The purge pump  50  is supported in the internal space of the corner wall portion  22  with a predetermined gap therebetween. This gap is maintained by the left projections  40 , the right projections  41 , the upper left projection  42 , the upper right projection  43 , the lower left projection  44 , and the lower right projection  45  of the pump mounting portion  20  (see  FIG. 2 ). Thus, a gap passage  75 , which communicates the front end opening of the pump mounting portion  20  with the rear wall  28  of the pump mounting portion  20 , is provided between the corner wall portion  22  of the pump mounting portion  20  and the purge pump  50  (see  FIGS. 2 to 4 ). 
     The rear end of the gap passage  75  is in fluid communication with the outside air via the first communication hole  70  and the second communication hole  72  of the pump mounting portion  20  (see  FIG. 4 ). As previously described, the gap passage  75  extends between the corner wall portion  22  of the pump mounting portion  20  and the purge pump  50 . A predetermined distance may be set between the rear wall  28  of the pump mounting portion  20  and the front side, excluding the suction port  56 , of the purge pump  50  (see  FIG. 4 ). 
     The purge pump  50  is positioned so that the motor housing  62  of the motor unit  60  faces the left side wall  23  of the pump mounting portion  20 . The motor housing  62  is disposed in the portion of the gap passage  75  that extends substantially linearly from the front end opening toward the first communication hole  70  and the second communication hole  72 . The purge pump  50  is positioned so that the pump housing  54  of the pump unit  52  faces the right side wall  24  of the pump mounting portion  20 . 
     The canister  10 , to which the purge pump  50  is mounted (see  FIG. 1 ), may be attached to a rigid structure, such as a frame of a vehicle. Therefore, when a vehicle is traveling, the air introduced to the pump mounting portion  20  of the canister  10  via the opening thereof passes through the gap passage  75 . The air is then discharged to the outside via the first communication hole  70  and the second communication hole  72 . As a result, heat accumulated in the gap passage  75  is dissipated. 
     According to the accessory component mounting structure of the present embodiment, the gap passage  75  in fluid communication with the outside via the first communication hole  70  and the second communication hole  72  is provided between the pump mounting portion  20  and the purge pump  50 . Accordingly, air can pass through the gap passage  75 , thereby dissipating heat accumulated in the gap passage  75  and preventing the heat generated by the motor unit  60  of the purge pump  50  from accumulating in the internal space of the pump mounting portion  20  of the canister  10 . Consequently, deterioration of the purge pump  50  due to a rise in temperature of the purge pump  50  may be reduced and/or avoided. Further, moisture that may have entered the gap passage  75  may be discharged to the outside together with the air introduced into the gap passage  75 . 
     Since the left projections  40 , the right projections  41 , the upper left projection  42 , the upper right projection  43 , the lower left projection  44 , and the lower right projection  45  provided on the pump mounting portion  20  abut the purge pump  50 , rattling of the purge pump  50  is suppressed. At the same time, it is possible to form the gap passage  75 . By suppressing the rattling of the purge pump  50 , it is possible to suppress the vibration of the purge pump  50  and the wear of the contact portion between each of the projections  40  to  45  and the purge pump  50 . Since the projections  40  to  45  aid in the formation of the gap passage  75  and the support of the purge pump  50 , the configuration may be simplified in the present embodiment. 
     The left projections  40 , the right projections  41 , the upper left projection  42 , the upper right projection  43 , the lower left projection  44 , and the lower right projection  45  are provided on the pump mounting portion  20 . Therefore, compared with the case where the projections  40  to  45  are formed on the purge pump  50 , the dimensions of the projections  40  to  45  may be more easily controlled, and the support position of the purge pump  50  may be more easily managed. Further, it is possible to prevent the heat generated by the motor unit  60  of the purge pump  50  from accumulating in the internal space of the pump mounting portion  20  of the canister  10 . Moreover, this may be done without requiring a design change of the purge pump  50 . 
     The purge pump  50  is held by the projecting ends of the projections  40  to  45 . Accordingly, the degree of rattling of the purge pump  50  may be easily adjusted and controlled by the extension amount of the projections  40  to  45 , as compared with the case where the purge pump  50  is held in a surface contact by the inner surface of the corner wall portion  22 . 
     The first communication hole  70  is formed at the left side wall  23  of the pump mounting portion  20 , which is exposed to the outside. The second communication hole  72  is formed at the left end  28   a  of the rear wall  28  of the pump mounting portion  20 , which is exposed to the outside. Therefore, the air permeability of the gap passage  75  may be improved. 
     The purge pump  50  is disposed such that the motor unit  60  faces the left side wall  23  of the pump mounting portion  20 , which is exposed to the outside. Therefore, it is possible to suppress heat from accumulating on the right side wall  24  as compared with the case where the motor unit  60  of the purge pump  50  faces the right side wall  24  of the pump mounting portion  20 , which is not exposed to the outside. As a result, the resin deterioration of the right side wall  24  may be suppressed. 
     Since the motor unit  60  of the purge pump  50  is exposed to the gap passage  75 , the cooling efficiency of the motor unit  60  may be improved by the air passing through the gap passage  75 . Since the motor unit  60  is disposed in the portion of the passage that extends substantially linearly from the front end opening of the gap passage  75  toward the first communication hole  70  and the second communication hole  72 , the cooling efficiency of the motor unit  60  may be further improved. 
     The rigidity of the pump mounting portion  20  may be improved by the first reinforcing rib  47 , which is formed on the outer peripheral of the opening end of the corner wall portion  22  of the pump mounting portion  20 . 
     The rigidity of the pump mounting portion  20  may be improved by the second reinforcing rib  48  formed on the outer peripheral of the central portion, in the front-rear direction, of the corner wall portion  22  of the pump mounting portion  20 . 
     Since the heat dissipation area of the pump mounting portion  20  is increased by the first reinforcing rib  47  and the second reinforcing rib  48 , heat dissipation of the internal space of the pump mounting portion  20  may be promoted. 
     The above is a description of an embodiment of the technology disclosed herein. However, the technology may be implemented in various other forms. For example, in the above embodiment, the purge pump  50  is exemplified as an accessory component. However, an On-Board Diagnosis (OBD) pump used for a leakage test of the canister  10  performed when the engine of the vehicle is stopped or any other component may be used as the accessory component. 
     In the above embodiment, the gap passage  75  is formed by providing support projections on the pump mounting portion  20 . However, the gap passage  75  may alternatively be formed by providing support projections on the purge pump  50 . Further, the gap passage  75  may alternatively be formed by providing support protrusions on both the pump mounting portion  20  and the purge pump  50 . The rib-shaped support protrusion may be one or more. The support projection is not limited to a rib-shape and may be changed to an arbitrary shape as long as the support projection forms a gap passage. 
     For example, the number, shape, and position of the communication hole may be changed as appropriate. For example, one of the first communication hole  70  and the second communication hole  72  may be omitted. The number of the first communication hole  70  and/or the second communication hole  72  may be increased (e.g., more than one first communication hole  70  and/or more than one second communication hole  72  may be provided). A communication hole may be formed at a lower end  28   b  of the rear wall  28 . In the above embodiment, the front end opening of the pump mounting portion  20  is used as an air inlet, and the first communication hole  70  and the second communication hole  72  are used as air outlets. Alternatively, the first communication hole  70  and the second communication hole  72  of the pump mounting portion  20  may be used as inlets, and the front end opening may be used as an outlet. 
     The first reinforcing rib  47  may be omitted. The number of the second reinforcing ribs  48  may be increased or may be omitted. The reinforcing rib may be formed on an outer peripheral of the component mounting portion, or may also be formed on an inner periphery thereof. In addition, the reinforcing ribs may be formed continuously in the circumferential direction of the component mounting portion, or may be formed intermittently in the circumferential direction. 
     The various examples described above in detail with reference to the attached drawings are intended to be representative of the present disclosure and are thus non-limiting embodiments. The detailed description is intended to teach a person of skill in the art to make, use, and/or practice various aspects of the present teachings, and thus does not limit the scope of the disclosure in any manner. Furthermore, each of the additional features and teachings disclosed above may be applied and/or used separately or with other features and teachings in any combination thereof, to provide an improved accessory component mounting structure for a canister, and/or methods of making and using the same. 
     Techniques are disclosed in various aspects in the present disclosure. A first embodiment is an accessory component mounting structure for a canister including a tubular component mounting portion provided in the canister and an accessory component having a heat-generating portion that generates heat. The accessory component is inserted into the internal space of the component mounting portion and is mounted by snap-fitting. A gap passage communicating an opening side of the component mounting portion with the rear side thereof is formed between the component mounting portion and the accessory component. A communication hole providing fluid communication between the gap passage and the outside is formed in the component mounting portion. 
     According to the first embodiment, the gap passage communicating with the outside via the communication hole is formed between the component mounting portion and the accessory component. Therefore, air may pass through the gap passage and the heat accumulated in the gap passage may be dissipated. As a result, it is possible to suppress the heat generated by the heat-generating portion of the accessory component from accumulating in the internal space of the component mounting portion of the canister. 
     A second embodiment is the accessory component mounting structure for the canister according to the first embodiment, wherein the component mounting portion is provided with a support projection. The support projection abuts the accessory component and forms a gap. The gap serves as the gap passage. 
     According to the second embodiment, since the support projection provided on the component mounting portion abuts the accessory component, it is possible to form a gap that serves as the gap passage while also suppressing the rattling of the accessory component. Since the support projection is formed on the component mounting portion, compared with the case where the support projection is formed on the accessary component, the dimensions of the support projection may be easily controlled and the support position of the accessory component may be easily managed. Further, it is possible to prevent the heat generated by the heat-generating portion of the accessory component from accumulating in the internal space of the component mounting portion of the canister. This may be done without requiring a design change in the accessary component. 
     A third embodiment is the accessory component mounting structure for the canister according to the first embodiment or the second embodiment, wherein the communication holes are formed at a side wall and a rear wall of the component mounting portion, wherein the side and rear walls are exposed to the outside. 
     According to the third embodiment, since the communication holes are formed at a side wall and a rear wall of the component mounting portion, with the walls being exposed to the outside, the air permeability of the gap passage may be improved. 
     A fourth embodiment is the accessory component mounting structure for the canister according to any one of the first to third embodiment, wherein the accessory component is disposed such that the heat-generating portion faces the side wall of the component mounting portion, the side wall being exposed to the outside. 
     According to the fourth embodiment, it is possible to suppress heat from accumulating on the wall of the component mounting portion that is not exposed to the outside, as compared with the case where the heat-generating portion of the accessory component faces the wall of the component mounting portion that is not exposed to the outside. 
     A fifth embodiment is the accessory component mounting structure for the canister according to any one of the first to fourth embodiment, wherein the heat-generating portion of the accessory component is exposed to the gap passage. 
     According to the fifth embodiment, since the heat-generating portion of the accessory component is exposed to the gap passage, the cooling efficiency of the heat-generating portion may be improved by the air passing through the gap passage. 
     A sixth embodiment is the accessory component mounting structure for the canister according to any one of the first to fifth embodiment, wherein a reinforcing rib, which extends in the circumferential direction is formed on the component mounting portion. 
     According to the sixth embodiment, the rigidity of the component mounting portion may be improved by the reinforcing rib, which is formed on the component mounting portion. Since the heat dissipation area of the component mounting portion is increased by the reinforcing rib, heat dissipation of the internal space of the component mounting portion may be promoted.