Air bag cover

An air bag cover is formed of synthetic resin and is connected to and held by the body of a car in a plurality of discontinuous portions thereof along the peripheral edge of an opening formed on the interior side of the car in such a manner that the air bag cover not only can cover an air bag folded in the peripheral edge of the opening on the car interior side, but also, when an air bag main body of the air bag is developed and expanded, can be so opened and moved as to allow the air bag main body to project toward the opening side. The air bag cover further includes a restricting wall which projects toward the body of the car in such a manner that it can connect together these connecting/holding portions while the restricting wall is disposed on the back surface side of the air bag cover, in more particular, on the side of the folded air bag main body that is distant from the opening and on the opening side of connecting/holding portions.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to an air bag cover which is formed of
 synthetic resin and is used to cover an air bag of a side air bag device
 to be stored into the peripheral edge of an opening formed in the
 periphery of a door of a car or the like.
 The present application is based on Japanese Patent Application No. Hei.
 10-129300, which is incorporated herein by reference.
 2. Description of the Related Art
 Conventionally, in a side air bag device of this type, an air bag is folded
 and stored in the peripheral edge of an opening formed in the peripheral
 edge of a door or a window on the interior side of a car, in particular,
 over a portion thereof extending from a pillar portion and roof side rail
 portion; and, when gas for expansion is charged into the air bag, an air
 bag cover covering the folded air bag is opened and moved to thereby
 develop and expand the air bag (see Japanese Patent Publication No. Hei.
 9-315253).
 And, in order that, when the air bag is developed and expanded, the air bag
 cover can be opened and moved by a given amount while preventing the
 damage thereof, on the back surface side of the air bag cover, in
 particular, in the two discontinuous portions thereof along the peripheral
 edge of the above-mentioned opening, there are provided a plurality of
 connecting/holding portions where the air bag cover can be connected to
 and held by the body of the car (see Japanese Patent Application No. Hei.
 9-129617).
 However, in the early stage of the expansion of the air bag main body,
 during the time until the air bag main body projects toward the opening
 side, the pressure of the air bag main body acts on a wide area on the
 back surface side of the air bag cover and, for this reason, the
 connecting/holding portions themselves must be so formed as to have a
 strength of a certain degree.
 Therefore, in order to enhance the strength thereof, the connecting/holding
 portions are structured in such a manner that they are large in thickness.
 However, since the air bag cover itself is molded of synthetic resin, a
 sink or a depression is easy to occur in the air bag cover due to the
 large thickness of the connecting/holding portions.
 SUMMARY OF THE INVENTION
 The present invention aims at eliminating the above drawback found in the
 conventional air bag covers. Accordingly, it is an object of the invention
 to provide an air bag cover which can prevent occurrence of such sink to
 thereby be able to secure a sufficient strength when expanding an air bag.
 In attaining the above-object, according to the invention, there is
 provided an air bag cover which is formed of synthetic resin and also
 which is connected to and held by the body of a car in a plurality of
 discontinuous connecting/holding portions thereof along the peripheral
 edge of an opening formed on the interior side of the car in such a manner
 that it covers an air bag folded in the peripheral edge of the
 above-mentioned opening and, when an air bag main body of the folded air
 bag is developed and expanded, it can be so opened and moved as to allow
 the air bag main body to project toward the above-mentioned opening. A
 restricting wall projects toward the car body in such a manner that it can
 connect together the plurality of connecting/holding portions on the back
 surface side of the present air bag cover, in more particular, on the side
 of the air bag main body that is distant from the above-mentioned opening
 and on the above-mentioned opening side of the connecting/holding
 portions.
 According to the invention, the present air bag cover includes the
 projecting wall which projects toward the car body in such a manner that
 it can connect together the plurality of connecting/holding portions on
 the back surface side of the present air bag cover, in more particular, on
 the side of the air bag main body that is distant from the above-mentioned
 opening and on the above-mentioned opening side of the connecting/holding
 portions. Thanks to this, until the air bag main body projects toward the
 opening side in the early stage of the expansion of the air bag main body,
 even if the pressure of the air bag main body is going to act on the
 respective connecting/holding portions, such pressure is allowed to act
 only a small area due to the restricting wall disposed on the opening side
 of the connecting/holding portions, thereby being able to reduce the
 pressure loads that could be applied onto the respective
 connecting/holding portions.
 This in turn makes it possible to reduce the thicknesses of the respective
 connecting/holding portions, thereby being able to prevent the sink that
 could be otherwise produced in molding.
 Therefore, according to the invention, there can be provided an air bag
 cover which can prevent the occurrence of the sink to thereby be able to
 secure a sufficient strength when the air bag is expanded.
 Also, since, when the air bag main body is developed and expanded, the
 expansion of the air bag main body parting away from the opening side is
 restricted by the restricting wall, the projecting direction of the air
 bag main body can be directed in a given direction, which makes it
 possible to increase the fly-out speed of the air bag main body toward the
 opening side.
 Features and advantages of the invention will be evident from the following
 detailed description of the preferred embodiments described in conjunction
 with the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
 Now, description will be given below of an embodiment of an air bag cover,
 according to the invention with reference to the accompanying drawings.
 That is, an air bag cover 11 according to the embodiment of the invention
 shown in FIGS. 1, 2 and 4 to 6 is an air bag which can be used in a side
 air bag device M incorporating therein an air bag 41 that is folded
 between a front pillar portion PF and a roof side rail portion R disposed
 in the peripheral edge of an opening W formed in a door portion or a
 window portion on the interior side of a car.
 The side air bag device M comprises an air bag 41, an inflator 39 which is
 used to supply gas for expansion to the folded air bag 41, a mounting
 bracket 36 which is used not only to connect the air bag 41 to the
 inflator 39 but also to mount and fix the inflator 39 to a side panel 2 of
 a body 1 of the car, and two kinds of air bag covers of a first cover 11
 and a second cover 31 for covering the folded air bag 41. An air bag
 cover, according to the present embodiment, is composed of a garnish 11 as
 the first air bag cover disposed in the front pillar portion PF and a roof
 interior member 31 as the second air bag cover disposed in the roof side
 rail portion R. And, according to the present embodiment, the air bag
 cover, which is to be connected to and held by the body 1 through three
 connecting/holding portions thereof 13, 17 and 19 thereof, is formed as
 the garnish 11.
 Also, according to the present embodiment, until the side air bag device M,
 with the air bag 41 extending from the front pillar portion PF to the side
 rail portion R, is mounted onto the body 1 of the car, as shown in FIG.
 10, the side air bag device M is treated as an air bag assembly A.
 Referring to the structure of the front pillar portion PF, as shown in
 FIGS. 2 to 6, the front pillar portion PF comprises an folded air bag 41;
 a front pillar main body 4, which is situated on the body 1 side and is
 composed of a reinforcing panel 6, an inner panel 7 and an outer panel 6
 respectively made of steel plates; and, a garnish 11 serving as an air bag
 cover 11 which is to be mounted on and fixed to the inner panel 7 for
 covering the folded air bag 41.
 At given positions of the inner panel 7, there are formed a mounting hole
 7a (see FIG. 6) for mounting and fixing the garnish 11, a securing hole 7c
 (see FIG. 4), a securing hole 7d (see FIGS. 2 and 3), and a mounting hole
 7g (see FIG. 5) for mounting the folded air bag 41. A nut 7b is fixed to
 the mounting hole 7a, and a mounting bolt 29 serving as fixing means for
 mounting and fixing the garnish 11 is inserted into the mounting hole 7a:
 and, the securing leg portion 17 of the garnish 11 is inserted into and
 secured to the securing hole 7c.
 Also, a securing pin 21, which is disposed in the garnish 11 and is formed
 of metal, is inserted into and secured to the securing hole 7d. The
 securing hole 7d includes a large-width portion 7e opened in a circular
 shape and a small-width portion 7f having a smaller opening width than the
 large-width portion 7e and extending from the large-width portion 7e. The
 extending direction of the small-width portion 7f is a direction in which
 a sliding/securing portion 19 of a cover main body 12 (which will be
 discussed later) with the securing pin 21 embedded therein is moved when
 the air bag 41 is developed and expanded; and, in the present embodiment,
 the small-width portion 7f is formed in such a manner as to extend
 obliquely upwardly along the front pillar portion PF.
 Also, the mounting hole 7g is formed in the inner panel 7 in such a manner
 that a nut 7h is fixed to the peripheral edge of the back surface side
 (car outside) of the inner panel 7. Further, a weather strip S is mounted
 on the end portion of the pillar main body 4. By the way, reference
 character D shown in FIGS. 2, 4 to 7 designates a door of a car.
 The garnish 11 serving as an air bag cover is composed of a garnish main
 body 12 serving as a cover main body formed of synthetic resin such as
 olefin-system thermoplastic elastomer or the like, and a cap 25 to be
 disposed in the garnish main body 12.
 The garnish main body 12 serving as a cover main body, as shown in FIGS. 2,
 and 4 to 6, comprises a long molding portion 12a which is formed by
 injection molding, and a surface layer 12e which is formed of fabric or
 the like and is to be bonded onto the design surface side of the garnish
 main body 12; and, the molding portion 12a includes, in the edge thereof
 on the opening W side, a door portion 12d with a thin hinge portion 12c
 interposed between a general portion 12b thereof and the door portion 12d,
 whereby, when developing and expanding the air bag 41, the door portion
 12d can be rotated about the hinge portion 12c to be opened with respect
 to the general portion 12b. By the way, in the general portion 12b, not
 only there are disposed a mounting boss portion 13, the securing leg
 portion 17, and the sliding/securing portion 19 with the securing pin 21
 embedded therein, but also there is provided a restricting wall 23. Also,
 the molding portion 12a is formed by insert molding, in which the securing
 pin 21 is used as an insert.
 And, in the upper portion of the garnish main body 12, as shown in FIGS. 1,
 6 and 8, there is formed the mounting boss portion 13 including a mounting
 hole 13a through which the mounting bolt 29 can be inserted. A sleeve 15,
 which is formed of metal, is fitted with the inner peripheral surface of
 the mounting hole 13a so that the fastening force of the mounting bolt 29
 can be secured when the garnish main body 12 is mounted and fixed to the
 inner panel 7. Also, in the periphery of the mounting boss portion 13 that
 is situated on the front surface side (car interior side) of the garnish
 main body 12, there is formed a storing recessed portion 14 into which the
 cap 25 can be fitted.
 The cap 25, which is used to cover the mounting bolt 29, includes a molding
 portion 25a which can be formed of synthetic resin such as polyamide or
 the like by injection molding, and a surface layer 25c which is formed of
 the same material as the surface layer 12e and is to be bonded to the
 molding portion 25a. In the molding portion 25a, there is provided a
 securing pawl 25b which can be secured to a securing groove 29b formed in
 the head portion 29a of the mounting bolt 29. By the way, in the cap 25,
 there is disposed a removal preventive member which can be inserted via a
 through hole (not shown) formed in the storing recessed portion 14 and is
 capable of securing the cap 25 to the peripheral edge of the present
 through hole: that is, even if the cap 25 is removed from the mounting
 bolt 29, the present removal preventive member is able to prevent the cap
 25 from being removed from the garnish main body 12.
 On the back surface side of the garnish main body 12, in more particular,
 in a substantially middle portion thereof in the vertical direction, as
 shown in FIG. 4, there is formed the securing leg portion 17 which can be
 inserted into and secured to the securing hole 7c of the inner panel 7.
 Also, in the lower portion of the back surface side (car exterior side) of
 the garnish main body 12, as shown in FIGS. 2 and 3, there is formed the
 sliding/securing portion 19 in which the securing pin 21 is embedded. On
 the front surface side (car interior side) of the sliding/securing portion
 19, as shown in FIGS. 2 and 9, there are formed a large number of
 lightening holes 19a in order to be able to restrict the influence of the
 sink or depression as much as possible.
 The securing pin 21, which is formed of metal such as brass or the like,
 includes a embedding flange portion 21a and a securing flange portion 21c
 which are respectively formed in the two end portions of a
 cylindrical-shaped shaft portion 21b of the securing pin 21 in such a
 manner as to project in the radial direction of the securing pin 21. And,
 the embedding flange portion 21a is embedded in the sliding/securing
 portion 19. On the other hand, the securing flange portion 21c is secured
 to the peripheral edge of the small-width portion 7f of the securing hole
 7d formed in the inner panel 7, with the shaft portion 21b inserted
 through the small-width portion 7f. The securing flange portion 21c is
 formed larger than the opening width of the small-width portion 7f, and
 the securing flange portion 21c also have such size and shape as permits
 itself to be inserted into the large-width portion 7e of the inner panel 7
 from the front side (car interior side) of the inner panel 7.
 And, on the back surface side (car exterior side) of the garnish main body
 12, as shown in FIGS. 1, 2, 4 to 6, 8 and 9, there is provided the
 restricting wall 23 which projects toward the inner panel 7 side of the
 body 1, in order that the mounting boss portion 13, securing leg portion
 17 and sliding/securing portion 19 respectively serving as the
 connecting/holding portions can be connected together on the side of the
 main body 42 of the folded air bag 41 that is distant from the opening W,
 and on the opening W side of the connecting/holding portions 13, 17 and
 19. The thickness t (see FIG. 9) of the restricting wall 23 is set in the
 range of 1-4 mm, in order to be able to prevent any sink from being
 produced on the front surface side of the molding portion 12a. If the
 thickness t exceeds 4 mm, then the sink is easy to occur; and, if the
 thickness t is less than 1 mm, then the molding portion 12a is difficult
 to mold and, even if the molding portion 12a can be molded, it is
 difficult to secure a given strength. By the way, in the present
 embodiment, the thickness t of the restricting wall 23 is set for 2 mm.
 Referring next to the roof side rail R, the roof side rail R, as shown in
 FIG. 7, includes the folded air bag 41, a roof side rail main body 9 which
 is formed of a steel plate and situated on the body 1 side, and a roof
 interior member 31 serving as an air bag cover which can be assembled to
 the body 1 at a given position (not shown) thereof.
 In the roof side rail main body 9, at a given position thereof, there is
 formed a mounting hole 9a into which the folded air bag 41 can be mounted.
 The mounting hole 9a is structured such that a nut 9b is fixed to the
 peripheral edge of the roof side rail main body 9 on the back surface (car
 exterior side) thereof. Also, a weather strip S is mounted on the end
 portion of the roof side rail main body 9.
 The roof interior member 31 is formed of synthetic resin having such
 flexibility that, when expanding the air bag 41, the edge 31a thereof on
 the opening W side can be pressed by the air bag 41 and separated easily
 from the roof side rail main body 9.
 And, the air bag assembly A employed in the side air bag device M according
 to the present embodiment, as shown in FIG. 10, comprises an air bag 41,
 an inflator 39, a mounting bracket 36 for connecting the air bag 41 and
 inflator 39 to each other, a plurality of mounting brackets 54 which can
 be assembled to the air bag 41 and can be used to mount the air bag 41
 onto the body 1, and a tape member 57 for wrapping the folded air bag main
 body 42.
 The air bag 41, as shown in FIG. 11, includes an air bag main body 42 which
 allows the gas for expansion from the inflator 39 to flow therein, and,
 when the gas for expansion flows therein, can develop from its folded
 state and expand in such a manner that it increases in thickness; a
 connecting cylindrical portion 50 to be connected to the inflator 39; and,
 a plurality of mounting piece portions 52 to be disposed on the upper edge
 side of the air bag main body 42.
 The air bag main body 42, which is formed of polyamide yarn or the like by
 double weaving the same, comprises a bag portion 43 including a car
 interior wall portion 43a and a car exterior wall portion 43b, a
 connecting portion 44 which is densely woven in the peripheral portion and
 central portion of the bag portion 43 in such a manner that it can seal
 the bag portion 43, and a plate-shaped portion 45 which is woven in a thin
 plate shape in the periphery of the connecting portion 44. By the way,
 after the air bag main body 42 is woven in a bag, on the air bag main body
 42, there is formed a coating layer by applying silicone or the like onto
 the surface of the air bag main body 42, in order to be able not only to
 enhance the heat resistance of the air bag main body 42 but also to
 prevent the leakage of the gas for expansion therefrom.
 The bag portion 43 includes: an expansion portion 43c which allows the gas
 for expansion to flow therein and, when the gas for expansion flows
 therein, can expand in such a manner that it increases in thickness; and,
 a gas flow-in portion 43d which allows the gas for expansion to flow into
 the expansion portion 43c.
 The connecting portion 44 comprises: a peripheral connecting portion 44a
 which is densely woven in such a manner that it can seal the bag portion
 43 in the periphery of the bag portion 43; and, two central connecting
 portions 44b which are respectively woven densely in such a manner as to
 be able to connect the car interior wall portion 43a and the car exterior
 wall portion 43b to each other in the neighborhood of the central portion
 of the expansion portion 43c of the bag portion 43. And, the central
 connecting portions 44b and 44b, when the bag portion 43 is expanded,
 respectively apply tensile forces onto an area ranging from the connecting
 cylindrical portion 50 to the upper rear portion of the air bag main body
 42 to thereby prevent the expansion portion 43c from moving toward the car
 exterior side even if such pressure as to move the expansion portion 43c
 toward the car exterior side is applied to the expansion portion 43c.
 The plate-shaped portion 45 is used not only to secure the whole shape of
 the air bag 41 ranging from the connecting cylindrical portion 50 to the
 upper rear portion of the air bag main body 42, but also to reduce the
 volume of the bag portion 43 to thereby shorten the time necessary up to
 the completion of the expansion of the expansion portion 43c. And, the
 plate-shaped portion 45 includes a front plate-shaped portion 45a for
 connecting the gas flow-in portion 43d and expansion portion 43c to each
 other, and a rear plate-shaped portion 45b for connecting the expansion
 portion 43c and rear-portion-side mounting piece portion 52B to each
 other.
 The connecting cylindrical portion 50 is mounted on the outside of the
 inflator 39 and, in more particular, it is disposed on the leading end
 portion of the gas flow-in portion 43d, that is, the portion of the
 inflator 39 where the connecting cylindrical portion 50 can be connected
 to the inflator 39 when it is tightened by the mounting bracket 36.
 And, the connecting cylindrical portion 50 includes, on the inner periphery
 side of the gas flow-in portion 43d, two cylindrical-shaped long and short
 inner tubes 46 and 47 in order to be able to secure its heat resistance
 against high-temperature gas for expansion from the inflator 39.
 Referring now to the mounting piece portions 52, as shown in FIGS. 5, 7 and
 11, there are formed mounting holes 52a in the mounting piece portions 52
 in such a manner that they extend through their respective mounting piece
 portions 52, and mounting brackets 54 are fixedly secured to their
 respective mounting piece portions 52, in order that the mounting piece
 portions 52 can be mounted to the pillar main body 4 and roof side rail
 main body 9 of the body 1 using their respective mounting bolts 55. Each
 mounting bracket 54 is composed of metal-plate-made inner and outer plates
 54a and 54b which are respectively disposed in the car interior and
 exterior portions of its associated mounting piece portion 52, while inner
 and outer plates 54a and 54b include mounting holes 54c respectively in
 communication with the mounting hole 52a of their associated mounting
 piece portion 52. In mounting the inner and outer plates 54a and 54b,
 after their associated mounting piece portion 52 are respectively
 interposed between their associated inner and outer plates 54a and 54b, if
 the inner and outer plates 54a and 54b are staked in part, then they can
 be mounted to their associated mounting piece portion 52.
 The inflator 39, which is formed as an inflator of a cylinder type,
 includes: an inflator main body which is capable of discharging the gas
 for expansion from a given gas discharge port; and, a diffuser which is
 fixed to the inflator main body and is used to guide the gas for expansion
 in the axial direction of the inflator. And, to the end portion of the
 inflator 39, there is connected a lead wire 39a which is used to input a
 signal for discharging of the gas for expansion.
 The mounting bracket 36, which is formed of a metal plate, is structured
 such that it can connect the connecting cylindrical portion 50 of the air
 bag 41 mounted on the outside of the inflator 39 to the inflator 39, and
 also can mount the inflator 39, with the cylindrical portion 50 connected
 thereto, onto the side panel 2 of the body 1 using a bolt 37.
 The tape member 57 is formed of adhesive tape which is produced by applying
 adhesives onto cloth, paper or the like.
 Next, description will be given below of an operation to mount the side air
 bag device M onto a car. At first, there is prepared the air bag assembly
 A previously. The air bag assembly A can be prepared in the following
 manner.
 That is, firstly, the air bag 41 is folded by a given folding machine and
 is properly wrapped by the tape member 57. As a method for folding the air
 bag 41, according to the present embodiment, there is employed a twisted
 folding method in which folds C composed of ridge-shaped folds and
 recess-shaped folds are sequentially formed in the portions of the air bag
 41 that are respectively shown by two-dot chained lines in FIG. 12 and,
 after then, the air bag 41 is folded along the folds C.
 After then, while matching the mounting holes 52a and 54c to each other,
 the inner and outer plates 54a and 54b are arranged on the two sides of
 the respective mounting piece portions 52 and are then staked, and the
 mounting brackets 54 are respectively mounted onto their associated
 mounting piece portions 52. By the way, the mounting piece portions 52,
 which have been folded into the air bag 41, are pulled out from their
 folded positions and, after then, their associated mounting brackets 54
 are mounted onto the thus pulled-out mounting piece portions 52.
 Also, the folded condition of the connecting cylindrical portion 50 folded
 into the air bag 41 is also removed and, after then, the inflator 39 is
 inserted into the inner tube 47 of the thus unfolded connecting
 cylindrical portion 50, and further the mounting bracket 36 is mounted on
 the inflator 39.
 And, if the mounting bolts 55 are provisionally assembled to their
 respective mounting brackets 54 at a proper time, then the air bag
 assembly A can be assembled or prepared.
 After then, to mount the air bag assembly A onto the body 1 of the car, as
 shown in FIGS. 1, 4 and 7, the mounting bracket 36 is mounted on and fixed
 to the side panel 2 using the mounting bolt 37, and the mounting brackets
 54 are respectively arranged in the inner panel 7 of the pillar main body
 4 and in the roof side rail main body 9 in such a manner that the mounting
 holes 54c, 52a, 7g, 9a are matched to each other; and, after then, the
 respective mounting bolts 55 are threadedly engaged with their associated
 nuts 7h and 9b through the mounting holes 52a and 54c, so that the air bag
 assembly A can be mounted onto the body 1.
 And, after the air bag assembly A is mounted onto the body 1, the lead wire
 39a is connected to a given air bag operation circuit. At the same time,
 as shown in FIGS. 1 to 7, in the pillar portion PF, the garnish main body
 12 is mounted on and fixed to the inner panel 7 and, in the roof side rail
 portion R, the roof interior member 31 is assembled to a given portion of
 the body 1, thereby covering the air bag assembly A.
 To mount and fix the garnish main body 12 to the inner panel 7, after the
 securing flange portion 21c of the securing pin 21 is inserted (in
 particular, it is inserted to a position shown by a two-dot chained line
 2lcP in FIG. 3) from the large-width portion 7e of the securing hole 7d,
 the securing flange portion 21c is moved toward the small-width portion 7f
 (in particular, it is moved to a position shown by a solid line in FIG. 3)
 and, at the same time, the securing leg portion 17 is inserted into and
 secured to the securing hole 7c. Further, the mounting bolt 29 is
 threadedly engaged with the nut 7b of the mounting hole 7a through the
 mounting hole 13a of the mounting boss portion 13 and, next,
 simultaneously when the cap 25, which has been previously connected to the
 garnish main body 12, is fitted into the storing recessed portion 14, the
 securing pawl 25b is secured to the securing groove 29b of the bolt 29,
 thereby being able to complete the operation to mount and fix the garnish
 main body 12 to the inner panel 7 of the body 1; that is, the mounting of
 the side air bag device M into the car can be completed.
 And, after the side air bag device M is mounted into the car, if the
 inflator 39 is operated, then the gas for expansion is allowed to flow
 into the bag portion 43 of the air bag main body 42 of the air bag 41, so
 that the gas flow-in portion 43d and expansion portion 43c of the bag
 portion 43 are caused to expand to thereby break the tape members 57.
 Also, the garnish main body 12 of the garnish 11 in the pillar portion PF
 is pressed by the air bag main body 42, so that, as shown by two-dot
 chained lines in FIGS. 2, 4 to 6, the securing leg portion 17 is removed
 from the securing hole 7c and also the securing flange portion 21c of the
 securing pin 21 slidingly moves the small width portion 7e of the securing
 hole 7d to a position of 2lcB shown by a two-dot chained line in FIG. 3.
 Accordingly, the garnish main body 12 moves its lower portion obliquely
 upwardly along the pillar portion PF and moves its
 substantially-vertical-direction middle portion toward the car interior
 side in such a manner as to part from the inner panel 7, thereby opening
 the door portion 12d. Further, the roof interior member 31 of the roof
 side rail portion R is pressed by the air bag main body 42 to thereby, as
 shown by a two-dot chained line in FIG. 7, open the edge 31a of the roof
 interior member 31. As a result, as shown by a two-dot chained line in
 FIG. 1, the air bag main body 42 is developed and expanded greatly in such
 a manner as to cover the opening W.
 Now, as described before, on the back surface side of the garnish main body
 12 serving as an air bag cover according to the present embodiment, there
 is provided the restricting wall 23 which projects toward the inner panel
 7 side of the body 1, in order that, when the air bag main body is
 developed and expanded, the connecting/holding portions 13, 17 and 19 can
 be connected together due to the restricting wall 23, on the side of the
 folded air bag main body 42 that is distant from the opening W, and, in
 more particular, on the opening W side of the connection hold portions 13,
 17 and 19. Therefore, until the air bag main body 42 projects toward the
 opening W side in the developing and expanding operation of the air bag
 main body 42, even if the pressure F of the air bag main body 42 (see FIG.
 8) is going to act on the securing boss portion 13, securing leg portion
 17 and sliding/securing portion 19 respectively serving as the
 connecting/holding portions, the pressure F is allowed to act on only a
 small area due to the restricting wall 23 disposed on the opening W side
 of the connecting/holding portions 13, 17 and 19, thereby preventing the
 pressure F from being applied concentratedly onto the connecting/holding
 portions 13, 17 and 19 which respectively project on the back surface side
 of the garnish main body 12, which in turn can reduce pressure loads
 acting on the respective connecting/holding portions 13, 17 and 19.
 Thanks to this, the respective connecting/holding portions 13, 17 and 19
 can be formed small in thickness and, in. particular, in the present
 embodiment, the dimension X of the mounting boss portion 13 and
 sliding/securing portion 19 in the radial direction thereof as well as the
 thickness dimension Y of the securing leg portion 17 can be reduced,
 thereby being able to prevent the occurrence of the sink that could be
 otherwise produced in molding. By the way, in the present embodiment, the
 surface layer 12e is bonded to the surface side of the molding portion 12a
 of the garnish main body 12. However, unless the dimensions X and Y are
 rather small, in spite of the bonded surface layer 12e, there is a fear
 that depressions are caused to occur on the front surface side of the
 garnish main body 12 due to the sink.
 Therefore, in the garnish 11 serving as an air bag cover according to the
 present embodiment, the occurrence of the sink can be prevented to thereby
 be able to secure a sufficient strength when the air bag 41 is expanded.
 By the way, because the thickness t of the restricting wall 23 is set in
 the range of 1-4 mm, the occurrence of the sink can be prevented on the
 front surface side of the molding portion 12a.
 Also, in the present embodiment, since the expansion of the air bag main
 body 42 to be moved apart from the opening W is restricted by the
 restricting wall 23 when the air bag main body 42 is developed and
 expanded, the projecting direction of the air bag main body 42 is directed
 in a given direction, thereby being able to increase the fly-out speed of
 the air bag main body 42 toward the opening W side.
 Further, in the present embodiment, there is illustrated a case in which
 the restricting wall 23 is structured in a continuous wall. However, this
 is not limitative but, for example, as shown in FIG. 13, there can also be
 employed a structure in which the restricting wall 23 is composed of
 discontinuous walls 23. Or, as shown in FIG. 14, in consideration of an
 operation to remove the garnish main body 11 from the mold after it is
 molded, the individual restricting walls 23 can be arranged in a stepwise
 manner.
 Still further, in the present embodiment, as the connecting/holding
 portions, there are illustrated the following three portions: that is, the
 mounting boss portion 13 which is disposed in one end portion of the air
 bag cover 11 and is to be completely mounted on and fixed to the body 1;
 the sliding/securing portion 19 which is disposed in the other end portion
 of the air bag cover 11 and, when the air bag main body 42 is developed
 and expanded, can be connected to the body 1 in such a manner that it can
 be slided toward the central portion of the air bag cover ll; and, the
 securing leg portion 17 which is disposed in the neighborhood of the
 central portion of the air bag cover 11 and, when the air bag main body 42
 is developed and expanded, can be connected to the body 1 in such a manner
 that it can be removed toward the car interior side. However, this is not
 limitative but, for example, if the air bag cover is mounted on the body
 at a plurality of discontinuous positions thereof, then the
 connecting/holding portions can be all composed of connecting/holding
 portions that are mounted on and fixed to the body completely, or the
 connecting/holding portions can be used in combination with other kinds of
 connect/hold means.
 Moreover, in the present embodiment, as the air bag cover, there is
 illustrated the garnish 11 which is disposed in the front pillar portion
 PF. Of course, the invention is not limited to this. That is, the
 invention can also apply to an air bag cover which is disposed in the
 periphery of the opening formed on the car interior side such the center
 pillar portion PC, a rear pillar portion and the like, and is connected to
 and held by the body at a plurality of discontinuous positions thereof.