CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority from Japanese Patent Application No. 2009-109802 filed on Apr. 28, 2009. The entire content of this priority application is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a speaker apparatus for use in a vehicle. The speaker apparatus is to be mounted to the vehicle. 
     BACKGROUND 
     In a known speaker apparatus for use with a vehicle and to be mounted to the vehicle, a claw-fixing portion has been adopted as a means for fixing a speaker grille to an interior member. The interior material has an attachment hole to which the speaker grille is attached. On the other hand, the speaker grille has a claw-fixing portion to be engaged with a hole edge of the attachment hole. Thus, accompanying engagement of the claw-fixing portion with the hole edge, the speaker grille can fixed in the attachment hole. Claw fixing is advantageous than screwing, welding, etc. when miniaturization of the apparatus is required. 
     However, when subjected to a force, the claw-fixing portion can deform and easily slip out of the attachment hole. In order to avoid this inconvenience, screwing or welding referred above is generally used. However, screwing needs the speaker grille to be attached from the outside of the vehicle compartment. Then, the hole edge of the attachment hole has to be exposed to the inside of the compartment, which provides a poor appearance. On the other hand, welding needs to be performed in a direction perpendicular to the plane of the interior member. Accordingly, the speaker grille cannot be welded obliquely to a plane of the interior member. Thus, fixing the speaker grille to the interior member by claw fixing regardless of the shape of the interior member is difficult. 
     Thus, there is a need for a speaker apparatus that can be fixed by claw fixing regardless of the shape of the interior member and can be prevented from accidental removal from the interior member. 
     SUMMARY 
     A speaker apparatus in accordance with the present invention is for use with a vehicle having a compartment and is to be mounted to the vehicle. The speaker apparatus includes: an interior member including a hole edge that defines an attachment hole; a speaker unit configured to be placed in the attachment hole, the speaker unit including a limiting member; and a speaker grille configured to be attached in the attachment hole from an inside of the compartment, the speaker grille including a claw-fixing portion that is bendable and is configured to be engaged with the hole edge. Accompanying the engagement of the claw-fixing portion with the hole edge, the speaker grille is fixed to the interior member. Accompanying the placement of the speaker unit in the attachment hole, the limiting member is positioned in a bending space for the claw-fixing portion and thereby prevents disengagement of the claw-fixing portion from the hole edge. 
     With such a configuration, first, the claw-fixing portion is inserted into the attachment hole from the inside of the vehicle compartment and is engaged with the hole edge of the attachment hole. The speaker grille is then fixed to the interior member. Next, accompanying the placement of the speaker unit in the attachment hole, the limiting member is positioned in the bending space for the claw-fixing portion. Then, disengagement of the claw-fixing portion from the hole edge is prevented. Thus, the speaker grille is fixed by the claw fixing while is prevented from slipping out of the attachment hole regardless of the shape of the interior member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view illustrating a speaker grille in a state normally attached to a speaker unit; 
         FIG. 2  is an exploded sectional view illustrating the attachment structure of the speaker apparatus of  FIG. 1 ; 
         FIG. 3  is a front perspective view of the speaker grille; 
         FIG. 4  is a rear perspective view of the speaker grille; and 
         FIG. 5  is a front perspective view of the speaker unit. 
     
    
    
     DETAILED DESCRIPTION 
     &lt;Embodiment&gt; 
     An embodiment of the present invention will be described with reference to  FIGS. 1 through 5 . In this embodiment, as illustrated in  FIG. 1 , a speaker apparatus for use in a vehicle includes a speaker unit  10 , a speaker grille  20 , etc. An exploded sectional view of the speaker apparatus is illustrated in  FIG. 2 . Both the speaker unit  10  and the speaker grille  20  are attached and are fixed to a trim board  30 . The trim board  30  is an illustration of an “interior member”. Note that the left side and the right side in  FIGS. 1 and 2  are herein designated as the front and as the rear, respectively. 
     The trim board  30  is made of synthetic resin such as polypropylene, mixture of wood-based material and synthetic resin, etc. A skin  40  is adhered to a part or the entire of an inner face of the trim board  30 . Furthermore, the trim board  30  has a speaker attachment hole  31  formed through the thickness thereof. 
     The speaker attachment hole  31  is formed in an overhanging face of the trim board  30 . On the other hand, both the central axis of the speaker unit  10  and the central axis of speaker grille  20  are horizontally oriented. Thus, the protruding length of the top of the speaker grille  20  protrudes from the trim board  30  less than than the protruding length of the bottom. 
     The speaker unit  10  includes a speaker body  12  and a bracket  13 . The speaker body  12  has a speaker  11 . The bracket  13  supports the speaker body  12  so that the speaker body  12  is attached and fixed to a back face (a face opposed to the vehicle body) of the trim board  30  via the bracket  13 . The speaker  11  has a generally known structure such as a diaphragm. In this embodiment, the speaker  11  is a tweeter that can reproduce mainly high frequencies. The speaker body  12  has a metal frame that supports the outer peripheral edge of the speaker  11 . 
     As illustrated in  FIG. 5 , the bracket  13  has a cylindrical portion  14 . The cylindrical portion  14  is cylindrical and has a hollow throughout its back-and-forth length. The cylindrical portion  14  surrounds the speaker  11 . 
     The bracket  13  further has a protection frame  15  on a front end of the cylindrical portion  14 . The protection frame  15  covers the front of the speaker  11  so as to protect the speaker  11  from possible damage from the front. When attaching the speaker unit  10 , the operator can firmly hold the bracket  13  to support the speaker unit  10 . Because the protection frame  15  covers the speaker  11  and protects the speaker  11  from possible damage, the operator can handle the speaker unit  10  easily and without directly contacting the speaker  11 . 
     The bracket  13  further has two attachment plates  16  on the rear end of the cylindrical portion  14 . The attachment plates  16  extend in opposite directions with respect to the cylindrical portion  14 . Each attachment plate  16  has an attachment hole  17  formed through the thickness thereof. Screws (not illustrated) are inserted in the attachment holes  17  and then are screwed up into the trim board  30 . The speaker unit  10  is thus fixed to the trim board  30 . 
     As illustrated in  FIGS. 2 and 3 , the speaker grille  20  has a mesh  21 , a front opening member  22 , and a base  23 . The front opening member  22  has a substantially circular opening. The mesh  21  is stretched over the opening of the front opening member  22 . The base  23  supports the front opening member  22 . As illustrated in  FIG. 4 , the base  23  has a hollow throughout the back-and-forth length thereof. A front-end opening of the base  23  is substantially circular and is disposed coaxially with a front end of the opening of the front opening member  22 . A rear-end opening is substantially oval and is disposed obliquely to an axis of the front opening member  22 . 
     As illustrated in  FIG. 4 , the mesh  21  has a plurality of flaps  21 A. The flaps  21 A are inserted in respective first slits  22 A of the front opening member  22  and in respective second slits  23 A of the front end of the base  23 , and further extend rearward. The mesh  21  is thus fixed to the speaker grille  20  to cover the opening of the front opening member  22 . 
     As illustrated in  FIG. 4 , the base  23  of the speaker grille  20  has a plurality of claw-fixing portions  24 . The claw-fixing portions  24  extend rearward from the rear end of the base  23 . The claw-fixing portions  24  are circumferentially spaced from each other around the rear end of the base  23 . The claw-fixing portions  29  protrude beyond the rear end of the base  23 . The claw-fixing portions  24  can bend radially inward (i.e. toward the axis of the front opening member  22 ). 
     As illustrated in  FIG. 1 , each claw-fixing portion  24  has a recess  25 . The recess  25 A is fitted on a hole edge  32  of the speaker attachment hole  31 . The recess  25  has two walls opposed to each other with respect to the back-and-forth direction of the front opening member  22 . These walls configure engagement faces  26 . The engagement faces  26  are engaged with the hole edge  32  of the speaker attachment hole  31 . The plane of each engagement face  26  crosses the back-and-forth direction. Accompanying engagement of the engagement faces  26  with the hole edge  32  of the speaker attachment hole  31 , the speaker grille  20  is fixed to the trim board  30 . In addition, the claw-fixing portions  24  have support ribs  27 . As illustrated in  FIG. 4 , the support ribs  27  are disposed radially inside the claw fixing portions  24 . The support ribs  27  support the claw-fixing portions  24  against being broken. 
     Referring to  FIG. 5  again, the bracket  13  has a plurality of limiting pieces  18  (each is an illustration of a “limiting member”). The limiting pieces  18  are elongated in the back-and-forth direction and thin. The limiting pieces  18  are disposed in an area surrounding an outer peripheral face of the speaker  11 . Specifically, in this embodiment, the limiting pieces  18  are circumferentially spaced from each other on an outer peripheral face of the cylindrical portion  14 . When the speaker unit  10  is in a state normally placed in the speaker attachment hole  31  as illustrated in  FIG. 1 , the limiting pieces  18  are positioned radially inside the respective claw-fixing portions  24 . That is, the speaker unit  10  and the speaker grille  20  define a bending space that allows the claw-fixing portions  24  to bend, and the limiting pieces  18  are positioned in the bending space. A clearance is provided between each claw-fixing portion and the respective limiting piece  18 . The clearance is set such that the engagement faces  26  of the recess  25  are securely held in engagement with the hole edge  32  of the speaker attachment hole  31  even in the event when the claw-fixing portion  24  bends radially inward by the dimension for the clearance. Therefore, even when the speaker grille  20  is subjected to force, the claw-fixing portion  24  contacts the limiting piece  18  so that further bending deformation of the claw-fixing portion  24  is stopped. Thus, the claw-fixing portion  24  is safe from being removed from the engagement with the hole edge  32  of the speaker attachment hole  31 . 
     In addition, each limiting piece  18  has a guide end  19 . The limiting piece  18  has a contact portion for the claw-fixing portion  24  to contact. The guide end  19  is disposed in front of the contact portion. The guide end  19  extends radially inward and frontward. Thus, when the speaker unit  10  is being attached in the speaker attachment hole  31 , the guide end  19  guides the speaker unit  10  to the normal attachment position so that the attachment operation is easy. Furthermore, because the clearances are provided between the claw-fixing portions  24  and the respective limiting pieces  18 , the speaker unit  10  can be smoothly inserted to the inside of the base  23  of the speaker grille  20 . 
     This embodiment is configured as above. The operation of the present embodiment will hereinafter be described. First, the speaker grille  20  is attached to the trim board  30  from the inside of the compartment. More specifically, the claw-fixing portions  24  slidingly contact the hole edge  32  of the speaker attachment hole  31  while bending radially inward. Then, when a distal end portion of the claw-fixing portions  24  have passed the hole edge  32 , the claw-fitting portions  24  elastically return, and the recesses  25  is fitted on the hole edge  32 . The hole edge  32  is thus engaged with the front and rear engagement faces  26  of the recesses  25  in the back-and-forth direction, and the speaker grille  20  is fixed to the trim board  30 . Next, the speaker unit  10  is fixed to the speaker attachment hole  31  of the trim board  30  from the outside of the compartment. 
     Note here that, in this embodiment, accompanying attachment of the speaker unit  10  to the trim board  30  whereto the speaker grille  20  has been attached, the speaker unit  10  is placed in the base  23  of the speaker grille  20 , and the limiting pieces  18  are positioned radially inside the respective claw-fixing portions  24 . Therefore, further radially inward bending of the claw-fixing portions  24  is stopped, and the engagement faces  26  of the claw-fixing portions  24  are held in engagement with the hole edge  32  of the speaker attachment hole  31 . 
     As described above, in this embodiment, the limiting pieces  18  are positioned radially inside the claw-fixing portions  24 . Therefore, the claw-fixing portions  24  contacts the limiting pieces  18  so that the engagement faces  26  of the claw-fixing portions  24  are held in engagement with the hole edge  32  of the speaker attachment hole  31 . This makes it possible to prevent accidental removal of the speaker grille  20  even when the speaker grille  20  is subjected to force. Thus, even in the case where the speaker attachment hole  31  of the trim board  30  is arranged in the inclined face, accidental removal of the speaker grille  20  can be prevented. 
     Furthermore, because the speaker unit  10  includes the speaker body  12  and the bracket  13 , the operator can firmly hold the bracket  13  to handle the speaker unit  10 . This makes it easy to handle the speaker unit  10 . Furthermore, because the operator does not have to directly contact the speaker  11 , the speaker  11  can be protected from possible damage. Moreover, because the bracket  13  includes the limiting pieces  18  arranged around the cylindrical portion  14 , additional limiting pieces  18  can be provided by minor design change. 
     &lt;Other Embodiments&gt; 
     The present invention is not limited to the embodiment described above with reference to the drawings. For example, following embodiments are also included within the scope of the present invention. 
     (1) In the above-described embodiment, the speaker grille  20  is attached to the trim board  30 . In accordance with the present invention, the speaker grille  20  may be attached to other places such as a top face of an instrument panel, a pillar garnish, a quarter trim, a deck side trim. Furthermore, in the above-described embodiment, the speaker unit  10  is fixed to the trim board  30 . In accordance with the present invention, the speaker unit  10  may be fixed directly to the vehicle body panel. 
     (2) In the above-described embodiment, the wide and thin limiting pieces  18  are illustrated as the limiting member. In accordance with the present invention, the limiting member does not have to be wide and thin. The limiting member may be column-shaped protrusions. 
     (3) In the above-described embodiment, the tweeter is illustrated as the speaker  11 . In accordance with the present invention, the type of the speaker is not limited to the tweeter. For example, the speaker may be a full-range speaker. 
     (4) In the above-described embodiment, the limiting pieces  18  are arranged on the bracket  13 . In accordance with the present invention, the limiting member may be arranged on the speaker body  12 .
A speaker apparatus in accordance with the present invention is for use with a vehicle having a compartment and is to be mounted to the vehicle. The speaker apparatus includes: an interior member including a hole edge that defines an attachment hole; a speaker unit configured to be placed in the attachment hole, the speaker unit including a limiting member; and a speaker grille configured to be attached in the attachment hole from an inside of the compartment, the speaker grille including a claw-fixing portion that is bendable and is configured to be engaged with the hole edge. Accompanying the engagement of the claw-fixing portion with the hole edge, the speaker grille is fixed to the interior member. Accompanying the placement of the speaker unit in the attachment hole, the limiting member is positioned in a bending space for the claw-fixing portion and thereby prevents disengagement of the claw-fixing portion from the hole edge.