A lid-fastening structure for fastening a lid using a bolt, which is rotatably held in the lid for closing an adjustment opening. An insertion hole for inserting the bolt is formed in the lid. A portion of the circumferential edge of the insertion hole is cut out in a way that allows the bolt to slide, and a backslide-limiting opening for limiting the return of the bolt to the insertion hole is formed so as to be continuous with the circumferential edge. A supporting/fastening hole is formed continuous with the backslide-limiting opening to a smaller radius than is the insertion hole, the supporting/fastening hole being cut out so as to allow the bolt to advance.

TECHNICAL FIELD

The present invention relates to a structure including a lid for opening and closing an opening and a bolt for fastening the lid to an undercover, and more particularly to a lid-fastening structure for fastening a lid by using a bolt adapted to be threaded into an undercover through a hole formed in the lid.

BACKGROUND ART

A pendant fitment having an oblong hole and a temporary stop plate it) provided on one end side of the oblong hole for fitting engagement with a root of a thread of a bolt is known as disclosed in Patent Document 1, for example. A bolt is inserted into an opposite end side of the oblong hole and, thereafter, the pendant fitment provided with the temporary stop plate is displaced such that the temporary stop plate is caught by the thread of the bolt. The pendant fitment does not need to be supported by a human operator and, hence, a work for threading a nut with the belt becomes ease.

A ceiling hanger having an elongated hole formed by three holes communicating together is disclosed in Patent Document 2. The three holes are a loose fit hole having a diameter larger than an outside diameter of a bolt, a temporary stop hole continuous with the loose fit hole and having a diameter slightly larger than a root diameter of the bolt, and a locking hole continuous with the temporary stop hole and having a diameter for ordinary threading engagement with the bolt. The three holes have a continuous width that allows movement of the bolt from the loose fit hole to the locking hole. The loose fit hole of the ceiling hanger is loosely fitted with the bolt and then the ceiling hanger is displaced such that the temporary stop hole is caught by a thread of the bolt.

A band-like spring member having a C-shaped coupling section and three locking sections extending radially outwards from opposite ends and an intermediate portion of the C-shaped coupling section for gripping a bolt is disclosed in Patent Document 3, for example. The band-like spring member is forced against a bolt so that the bolt moves toward an opening of the C-shaped coupling section, then forcibly opens the coupling section and finally fits with the band-line spring member.

However, when the technique disclosed in Patent Document 1 is applied to a member having an oblong hole, such as a lid or a like swingable member, it may occur that a bolt drops off under its own weight when the lid is opened. Furthermore, it is not possible to turn the bolt so that the bolt is screwed into the lid.

When used with a swingable member such as a lid, the technique disclosed in Patent Document 2 allows a bolt to return from the locking hole to the loose fit hole and eventually come off from the lid. An attempt to prevent returning of the bolt to the loose fit hole by reducing the diameter of the temporary stop hole will cause undue deformation by the bolt and eventually lose its prescribed temporary-stop function.

The technique disclosed in Patent Document 3 involves an increase in the number of parts used because of a stopper function required to prevent returning of the bolt from the opening of the C-shaped coupling section under the resiliency of the spring member. In case where a bolt is to be held on a plate-like member, a separate coupling member must be joined to the plate-like member.

According to the techniques disclosed in Patent Documents 1 to 3, works for fastening a lid (plate-like member) using a bolt cannot be performed speedily.

Patent Document 4 discloses a lid structure including a maintenance lid provided on an undercover located below an engine room. The lid structure is simple in construction, lightweight and inexpensive because the lid is detachable when moved to slid in a forward direction of the vehicle.

However, the lid structure disclosed in Patent Document 4 renders maintenance work and lid-assembling work tedious and time-consuming because when the lid is detached for maintenance, the detached lid should then be placed on a different position via a manual placement operation. Furthermore, when an engine is installed, on a manufacturing line, a tightening work should be performed from below after the undercover is attached, making the lid-assembling operation highly time-consuming. Additionally, the lid requires a pull-out space in front of the undercover, which will enlarge a working space in front of the undercover.

PRIOR ART LITERATURE

Patent Documents

SUMMARY OF INVENTION

Technical Problem

An object of the present invention is to provide a lid-fastening structure, which is able to ensure that a work for fastening a lid using a bolt can be performed speedily, and which can eliminate the need to provide a separate function to limit returning of the bolt.

Solution to Problem

In the invention according to a first aspect, there is provided a lid-fastening structure comprising: an undercover; a lid for closing an opening formed in the undercover; and a bolt rotatably held in the lid, wherein the lid includes: an insertion hole formed to allow insertion of the bolt; a backslide-limiting opening formed by cutting out a portion of a circumferential edge of the insertion hole in such a way as to allow the bolt to slide, the backslide-limiting opening being continuous with the circumferential edge of the insertion hole and configured to limit returning of the bolt to the insertion hole; a supporting/fastening hole formed continuous with the backslide-limiting opening to a radius smaller than a radius of the insertion hole, the supporting/fastening hole having a circumferential edge partially cut out to allow the bolt to enter the supporting/fastening hole; and a retainer part formed between an external thread and a bearing surface of the bolt for preventing the bolt from dropping off.

In the invention according to a second aspect, preferably, a portion including the backslide-limiting opening of the lid is formed by a material which is elastically deformable when the bolt is caused to slide.

In the invention according to a third aspect, preferably, the backslide-limiting opening has a tapered guide portion having a width reducing gradually in a in a direction away from the insertion hole.

In the invention according to a fourth aspect, preferably, the retainer part is in the form of a disk having a radius smaller than the radius of the insertion hole and larger than the radius of the supporting/fastening hole.

In the invention according to a fifth aspect, preferably, the lid has a front side adapted to be pressed by the bearing surface of the bolt and includes a protrusion formed on a back side thereof, the protrusion being located at such a position as to engage the bearing surface of the bolt when the bolt is inserted in the insertion hole from the back side of the lid.

In the invention according to a sixth aspect, preferably, the lid has one end portion releasably connectable to the undercover and an opposite end portion including a T-shaped engagement hook engaged with and held on the undercover, and the undercover has a stepped section configured to extend along an edge of the lid for engagement with the engagement hook, the stepped section having an assembly hole configured to allow passage of the hook.

In the invention according to a seventh aspect, preferably, the lid has a rib extending from the engagement hook toward the one end portion of the lid.

In the invention according to an eighth aspect, preferably, the stepped section includes a step higher than an inner surface of the undercover, and a bulged portion provided on the step so as to avoid interference with the lid when the lid is closed and lying alongside the inner surface of the undercover.

In the invention according to a ninth aspect, preferably, the lid includes a stepped rib extending across the rib.

In the invention according to a tenth aspect, preferably, the one end portion of the lid is fastened to the undercover by the bolt rotatably supported on the one end portion of the lid.

Advantageous Effects of Invention

In the invention according to the first aspect, the lid has an insertion hole, a backslide-limiting opening continuous with a circumferential edge of the insertion hole for limiting returning of a bolt to the insertion hole, a supporting/fastening hole having a radius smaller than a radius of the insertion hole and cut out to allow the bolt to enter the supporting/fastening hole, and the bolt has a retainer part provided between an external thread and a bearing surface for preventing the bolt to dropping off from the insertion hole. With this arrangement, the bolt can be held on the lid in a condition where the bolt is fitted in the supporting/fastening hole. This can eliminate the need to locate the bolt when the lid is to be reattached after removal. Fastening operation using the bolt can be achieved speedily.

In the invention according to the second aspect, because a portion including the backslide-limiting opening of the lid is formed by a material which is elastically deformable when the bolt is caused to slide, there is no need to provide a separate means for limiting returning of the bolt to the insertion hole.

In the invention according to the third aspect, since the backslide-limiting opening has a tapered guide portion having a width reducing gradually in a direction away from the insertion hole, the bolt is guided by the guide portion and hence is able to move smoothly when the bolt is caused to slide from the insertion hole toward the supporting/fastening hole.

In the invention according to the fourth aspect, since the retainer part is in the form of a disk having a radius smaller than the radius of the insertion hole and larger than the radius of the supporting/fastening hole, the bolt can smoothly move into fitting engagement with the supporting/fastening hole merely by forcing the bolt to slide.

In the invention according to the fifth aspect, by virtue of a protrusion formed on the back side of the lid and located at such a position as to engage the bearing surface of the bolt, when the bolt is inserted in the insertion hole from the back side of the lid, the bolt is caused to tilt to one side due to interference between the bearing surface and the protrusion, making it impossible to fully insert the bolt into the insertion hole. With the bolt thus tilting, the bearing surface and the retainer part of the bolt are non-parallel to a surrounding surface of the insertion hole and may interfere with the lid. The bolt is no longer possible to move (slide) in a direction toward the supporting/fastening hole. Wrong insertion of the bolt from the opposite side (back side) of the lid can thus be prevented.

In the invention according to the sixth aspect, a lid mechanism includes a lid having one end portion detachably connectable to the undercover and an opposite end portion engaged with and held on the undercover or another undercover. The lid includes a T-shaped engagement hook provided on the one end portion, and the undercover has a stepped section configured to extend along an edge of the lid for engagement with the engagement hook, and an assembly hole formed in the stepped section and configured to allow passage of the hook. With this arrangement, the lid hangs down from the stepped section and an edge of the assembly hole where the engagement hook is caught. At the time of manufacture, because the lid is hooked on the undercover and subsequently fastened (attached) to the undercover, the lid assembling operation can be achieved easily in a relatively short period of time.

Furthermore, since the lid can remain in a handing position during maintenance, the maintenance time can be reduced.

In the invention according to the seventh aspect, the rib extending from the engagement hook toward the one end portion of the lid serves to distribute an impact (load) produced when the lid or the engagement hook is subjected to an air resistance, splashing water, or a flying small pebble. The engagement hook is thus protected against undue distortion or flexing which may cause drop off of the lid.

In the invention according to the eighth aspect, since, the stepped section includes a step higher than an inner surface of the undercover, and a bulged portion provided on the step so as to avoid interference with the lid when the lid is closed and lying alongside the inner surface of the undercover, it is possible to arrange the lid alongside the inner surface of the undercover.

In the invention according to the ninth aspect, the stepped rib formed on the lib across the rib is able to reinforce the lid itself. The stepped rib has a function to distribute an impact (load) produced when the underside of the lid is subjected to an air resistance, splashed water, or a flying small pebble. By virtue of the stepped rib, distortion of the lid is further suppressed and drop off of the lid can be avoided with increased reliability.

In the invention according to the tenth aspect, since the one end portion of the lid is fastened to the undercover by the bolt rotatably supported on the one end portion of the lid, working time for fastening the lid using the bolt can be further reduced. This will allow for temporary opening of the lid during a vehicle-assembly-line operation for the purpose of achieving a work inside the engine room.

DESCRIPTION OF EMBODIMENTS

A preferred embodiment of the present invention will be described below in greater detail with reference to the accompanying sheets of drawings.

Embodiment

As shown inFIGS. 1 and 2, a vehicle11is provided with a lid structure12and a lid-fastening structure13. The lid structure12and the lid-fastening structure13are provided on an undercover16which covers an engine15from below.

The vehicle11includes a vehicle body17having a front body21, and the engine21supported on the front body21. The front body21includes a left front side frame22, a right front side frame23(FIG. 2) substantially the same as the left front side frame22, and a front sub-frame25mounted to the left and right front side frames22,23from below.

The right front side frame23and the left front side frame22are substantially symmetric with respect to a longitudinal centerline C passing through the center in a vehicle width direction.

The engine15is of the horizontal type. An engine body26has pistons (not shown) arranged in the width direction of the vehicle11. A non-illustrated transmission integrally connected with the engine body26is arranged to extend in the vehicle width direction.

With the engine body26and the transmission26being integrally united together, the engine body26of the engine15is fastened to the left and right front side frames22,23. The engine15has a front bracket28supported on an engine front mount31of the front sub-frame25.

The sub-frame25is formed into parallel crosses in a plan view of the vehicle11. The sub-frame25includes a front crossbeam33disposed adjacent to a front face of the vehicle, a left beam35extending from a left end34of the front crossbeam33in a rearward direction of the vehicle, a right beam37extending from a right end36of the front crossbeam33in a rearward direction of the vehicle, a rear crossbeam38interconnecting a rear end of the left barn35and a rear end of the right beam37, and the engine front mount31provided on the middle of the front crossbeam33.

As shown inFIG. 3, the engine front mount31supports a front part of the engine15and includes a base41joined to the front crossbeam33, and an engine fastening member42secured to the base41by means of a bolt43and a nut44. As shown inFIG. 2, the undercover16is attached to the sub-frame25from below.

The undercover16is composed of a front undercover47and a rear undercover48, as shown inFIGS. 2 and 6.

The front undercover47is formed from synthetic resin or plastic and extends from a bumper-face lower end51(FIG. 1) and a front bulkhead lower member53of a front bulkhead52to the front crossbeam33such that the front undercover47reaches the rear undercover48. The front undercover47is fixed to the bumper-face lower end51and the front bulkhead lower member53by means of clips (not shown).

As shown inFIG. 4, the front undercover47has a rear edge55cut out to form a relief opening56. The relief opening56is provided to open beneath a jack-retainer section57provided at the middle of the front crossbeam33of the front sub-frame25.

The front sub-frame25can be jacked up and down while the front sub-frame25including the jack-retainer section57is supported on a lift device61(FIG. 7). In this instance, the relief opening56prevents a front jack bearing surface62(FIG. 7) of the lift device61from interfering with the front undercover47.

The rear undercover48covers the engine body26and the transmission from below, as shown inFIG. 6. The rear undercover48is composed of a rear undercover body64formed from synthetic resin or plastic, an exhaust heat cover65formed of a steel plate, and a plastic lid66formed from synthetic resin or plastic (as indicated by a dotted pattern). As shown inFIG. 4, the rear undercover48had an edge attached by clips71(also seeFIG. 14) to a bottom68of the front sub-frame25.

The rear undercover48has an adjustment opening73formed in the vicinity of the engine front mount31. The adjustment opening73forms a part of the lid structure12.

In the lid structure12, the lid66is attached to the adjustment opening73by a fastening device13. As shown inFIG. 12, the fastening device13includes an undercover fastening section75provided on the rear undercover48, and an internal thread member76provided on the undercover fastening section75.

Referring now toFIGS. 1-11,14and17-19, the lid structure12is configured such that one end portion83(FIG. 11) of the lid66is releasably connected to the under cover16that covers the vehicle body17of the vehicle17or an engine room81of the vehicle body from below, and an opposite end portion84of the lid66is hooked or caught onto the undercover16or another undercover (not shown).

As shown inFIGS. 11 and 17, the lid structure12include T-shaped engagement hooks85, a stepped section87formed on the undercover16and configured to extend along an edge86of the lid66so as to engage and hold the engagement hooks85, and an assembly hole88formed in the stepped section87and configured to allow the passage of the engagement hooks85.

The lid structure12has ribs91(FIGS. 11,14and19) extending from each engagement hook85toward the one end portion83of the lid66. As shown inFIGS. 10 and 11, the stepped section87includes a step93higher than an inner surface92of the undercover16by a height H, and a bulged portion94provided on the step93and extending along the inner surface92of the undercover16so as to avoid interference with the lid66when the lid66is closed.

The lid structure12also includes a stepped rib95(also seeFIG. 19) formed on the lid66and extending across the ribs91. The one end portion83of the lid66is secured to the undercover16by means of bolts96(FIG. 12) rotatably held on the lid66.

As shown inFIGS. 8,9and12, the lid-fastening structure13includes the bolts96rotatably held on the lid66that closes the opening (adjustment opening)73. Reference numeral97denotes a fastening opening (seeFIG. 16) through which each bolt96passes.

As shown inFIG. 16, the lid66has an insertion hole101formed to allow insertion of the bolt96(FIG. 13), and a backslide-limiting opening104formed by cutting out a portion103of a circumferential edge102of the insertion hole101in such a way as to allow the bolt96to slide (in the direction of arrow a1), the backslide-limiting opening104being continuous with the circumferential edge102and configured as to limit returning of the bolt96to the insertion hole101.

Furthermore, the lid66also has a supporting/fastening hole108formed contiguous with the backslide-limiting opening104into a radius rh smaller than a radius r of the insertion hole101. A portion107of a circumferential edge106of the supporting/fastening hole108is cut out to allow the bolt96to enter the supporting/fastening hole108(in the direction of arrow a1).

As shown inFIG. 13, the bolt96has an external thread111, a bearing surface112, and a retainer part113provided between the external thread111and the bearing surface112for preventing removal of the bolt96from the supporting/fastening hole108. The retaining part113prevents the bolt96from moving in the direction of an axis cb of the bolt96(i.e., the E-axis direction) and eventually dropping off from the supporting/fastening hole108.

A portion including the backslide-limiting opening104of the lid66is formed by a material such as plastic which is elastically deformable when the bolt96is forced to slide (in the direction of arrow a1). The backslide opening104has a tapered guide portion115having a width reducing gradually in a direction away from the insertion hole101(i.e., the direction of arrow a1) from a maximum width W to a minimum width Wh.

The retainer part113is in the form of a disk having a radius rs which is smaller than the radius r of the insertion hole101and larger than the radius rh of the supporting/fastening hole108.

The lid66has a front side116(FIGS. 13,14,15and22) adapted to be pressed by the bearing surface112of the bolt96, and a back side117on which is formed a protrusion118of an arcuate shape (having a radius rb) for abutting engagement with the bearing surface112of the bolt96when the bolt96is inserted into the insertion hole101from the back side117(in the direction of arrow a2).

The fastening device13includes the bolts96provided on the lid66, and the fastening openings97(each including the insertion hole101, the supporting/fastening hole108, and the backslide-limiting opening104) formed in the lid66. The fastening device13also includes the undercover fastening sections75and the internal thread members76that are provided on the rear undercover48.

As shown inFIG. 13, each bolt96has a head141, a support shank142, the retainer part113, the external thread111, and a positioning part143. The head141has the bearing surface112and a flange145.

The support shank142has an outside diameter substantially equal to an outside diameter of the external thread111, and a length in a direction of the axis cb of the bolt96(i.e., the E-axis direction) which is slightly larger than a thickness of the lid66of the undercover16(by 2 mm, for example).

The retainer part113is in the form of a disk and has the radius rs substantially equal to a radius of the head141so that the retainer part113can pass through the insertion hole101formed in the lid66as shown inFIGS. 15 and 16. The radius r of the insertion hole111is larger than that of the retainer part113. The insertion hole101has a mouth (cutout portion103) formed in the circumferential edge thereof near the supporting/fastening hole108.

The radius rh (FIG. 16) of the supporting/fastening hole108is slightly larger than the radius of the support shank142of the bolt96. The supporting/fastening hole108has a mouth (cutout portion107) formed in the circumferential edge thereof near the insertion hole101(as indicated by a phantom line) so that the supporting/fastening hole108is continuous with the backslide-limiting opening104.

As shown inFIG. 16, the backslide-limiting opening104has a guide portion115formed at a desired angle α relative to a line S passing through the center T of the insertion hole101and the center Th of the supporting/fastening hole108.

Stopper parts147,147are formed at junctions between the guide portion115and the circumferential edge of the supporting/fastening hole108(located adjacent to the cutout portion107). The lid66is fastened to the undercover fastening section75by means of the bolt96while the bolt96is held in position against displacement by the stopper parts147,147.

As shown inFIGS. 10,12,13and20, the undercover fastening section75includes a raised fastening part151raised from the step93of the stepped section87at a front part of the step93. The raised fastening part151has a hole152for the passage therethrough of the retainer part113of the bolt96.

With the hole152being at the center, a first positioning rib153and a second positioning rib154are formed in opposed relation, and a third positioning rib155is formed continuously with, the first and second positioning ribs153,154. Reinforcing ribs156are disposed outside the second and third positioning ribs154,155and formed integrally with the second and third positioning ribs154,155, respectively.

The first positioning rib153faces forwardly of the vehicle11and is disposed upright along a front edge of the raised fastening part151directed forwardly of the vehicle11. The raised fastening part151has an inner edge158(FIG. 12) facing the lid66, and the internal thread member76is assembled with the inner edge158so as to grip the raised fastening part151.

The third positioning rib155has an internal thread positioning stopper161formed at an inner side thereof for determining a position (in the vehicle width direction) of the internal thread member76.

By thus providing the first, second and third ribs153,154,155, it is possible to increase the strength of the raised fastening part151. Furthermore, by virtue of the first and second ribs153,154and the internal thread positioning stopper161, it is possible to restrict movement of the internal thread member76in both a longitudinal (or front-rear) direction of the vehicle11and a width direction of the vehicle11.

As shown inFIGS. 12 and 13, the internal thread member76is assembled from the inner edge158of the raised fastening part151so that a clip portion163grips the raised fastening part151. The internal thread member163is composed of the clip portion163and an internal thread portion164formed integrally with the clip portion163. The internal thread member76is slightly movable in both the vehicle width direction and the longitudinal direction of the vehicle so that it can move to accommodate dimensional variation of various parts when the bolt96is threaded into the internal thread member76.

Referring next toFIGS. 17 to 20, lid assembly operation will be described. As shown inFIG. 17, each engagement hook85of the lid66is inserted through an insertion hole135of a corresponding one of the assembly holes88of the rear undercover48, as indicated by the arrow a4.

Then, as shown inFIG. 18, lateral projections132,132and a suspending support part131of the engagement hook85pass in succession through the insertion hole135. With the suspending support part131being inserted through a slide hole136of the assembly hole88, the lid66is turned in the direction of the arrow a6while the suspending support part131is allowed to slide along the slide hole136(also seeFIG. 19) in the direction of the arrow a5.

Subsequently, as shown inFIGS. 18,19and20, temporary stopper prongs128of the lid66are engaged with a rear edge166of the front undercover47located adjacent to the relief opening56, as indicated by the arrow a7. In this instance, the lateral projections132of each engagement hook85of the lid66are disposed near a wall134of the stepped section87but they are not in contact with the wall134of the stepped section87.

Finally, the bolts96held in advance on the lid66are threaded into internal thread portions164of the internal thread members76provided on the undercover fastening section75of the rear undercover48until the bolts96assume the position shown inFIG. 13. Assembly of the lid66is thus completed.

Operation of the lid-fastening structure13will next be described. The lid-fastening structure13can retain the bolts96while keeping a condition in which the96are fitted in the supporting/fastening holes108(FIG. 16) of the lid66. With this arrangement, there is no need locate bolts when the lid66is to be reattached after removal. The lid-fastening operation using the bolts96can thus be achieved in a rapid manner.

Referring next toFIGS. 21 and 22, description will be made of the manner in which the bolts96are assembled and also of an operation to limit returning of the bolts96.

At first, each bolt96is held with its distal end directed toward the front side116of the lid66, as indicated by phantom lines shown inFIG. 22, and the bolt96is inserted through the insertion hole101of the lid66, as indicated by phantom lines shown inFIG. 21(a) until the bearing surface112of the head141of the bolt96comes in contact with the rear undercover48, or alternatively, the support shank142of the bolt96is disposed in confrontation with an inner circumference of the insertion hole101.

Then the bolt96is moved to slide in the direction of the arrow b1. In this instance, the support portion115guides sliding movement of the support shank142of the bolt96. Subsequently, the support shank142comes in contact with the stopper parts147and then forces the stopper parts147to undergo elastic deformation, as shown inFIG. 21(b).

Finally, the support shank142passes through the stopper parts147and enters the supporting/fastening hole108, whereupon the stopper parts147recover their original shape and, hence, the mouth (cutout portion107) becomes narrower than the diameter of the support shank142. Now, the bolt96is hardly possible to move out from the supporting/fastening hole108. Assembly of the bolts96is thus completed.

In the lid-fastening structure13, because the bolts96are retained in a condition in which the bolts96are fitted in the supporting/fastening holes108of the lid66, there is no need to locate bolts when the lid66is reattached after removal (seeFIGS. 1 and 14). The bolt fastening operation can thus be achieved speedily.

Referring next toFIG. 22, a function to prevent wrong assembly of the bolt96will be described. If the bolt96is inserted into the insertion hole101from the back side117of the lid66as indicated by the arrow b2, the bolt96will tilt to one side due to interference with the bearing surface112of the bolt96and the protrusion118before the support shank142is fully received in the insertion hole101.

With the bolt96thus tilting, the bearing surface112and the retainer part113of the bolt96are non-parallel with a surrounding surface of the insertion hole101(on the back side117) and may interfere with the lid. The bolt96is no longer possible to move in a direction toward the supporting/fastening hole108. Wrong insertion of the bolt96from the opposite side (back side117) can thus be prevented.

Referring back toFIGS. 9 to 11, the lid structure12will be described in detail. The lid structure12includes the aforesaid adjustment opening73, the lid66, the engagement hooks85, the stepped section87, the assembly hole88, the ribs91, the bulged portion94, and the stepped rib95.

As shown inFIG. 9, the adjustment opening73is an opening formed by cutting out a part of a front edge121of the rear undercover48so as to face in a forward direction of the vehicle11. The adjustment opening73includes the stepped section87formed such that when the lid66is in the closed position, the lid66is received in the stepped section87and located at substantially the same height as a ground height of the undercover16.

The lid66has a body124formed into a generally rectangular plate-like configuration, as shown inFIGS. 8,11and19. The lid body124has an inverted U-shaped bulged body portion125provided at a front end thereof so as to avoid interference with the jack bearing surface62of the lift device61(FIG. 7).

As shown inFIG. 19, the bulged body portion125has an edge127rising to face forwardly of the vehicle11, and the temporary stopper prongs128project from the edge127in a forward direction of the vehicle11. The stepped rib95(FIG. 11) is formed between the engagement hooks85and the bulged body portion125of the lid body124and extends along the edge86(FIG. 11) of the lid66.

As shown inFIG. 11, each of the engagement hooks86is formed by the suspending support part131formed to project from the lid61, and the pair of lateral projections132formed to project from a distal end of the suspending support part131in opposite lateral directions perpendicular to the suspending support part131. When the lid66is opened (FIG. 14), the lateral projections132are hooked on the stepped section87.

As shown inFIG. 10, the stepped section87includes the wall134formed at a front portion of the undercover16and extending vertically upward from the inner surface92of the undercover16, and the step93formed continuously with the wall134and extending parallel to the undercover16. The bulged portion93provided on the step93has a length corresponding to a distance between two adjacent ones of the ribs91.

The assembly hole88formed in the undercover16has a T-shaped configuration, as shown inFIGS. 9 and 10. The assembly hole88includes the insertion hole135located on a forward side of the wall134and extending in the vehicle width direction, and a slide hole136continuous with the insertion hole135and extending perpendicular to the insertion hole135. The slide hole136has a width smaller than a width of the insertion hole135. The assembly hole88further includes a suspension hole137continuous with the slide hole136.

As shown inFIGS. 11,14and19, two adjacent ribs91are formed to have a distance therebetween, which divides the width of each engagement hook85into three substantially equal parts. These ribs91have upper edges extending straightway to the center of the lid66and also have a height varying to accommodate the difference in level formed by the stepped rib95. While the lid66is in a closed state, the ribs91are positioned below the bulged portion94.

The bulged portion94is formed in a region to cover the distance between the two adjacent ribs91and is able to reinforce that part93a(FIG. 10) of the step93in which the assembly hole88is formed.

Referring next toFIGS. 17 to 20, description will be made of the manner in which the lid66is assembled. Firstly, as shown inFIG. 17, each of the engagement hooks85of the lid66is inserted in the insertion hole135of the assembly hole88of the rear undercover48as indicated by the arrow a4.

Then, as shown inFIG. 18, the lateral projections132and the suspending support part131of the engagement hook85are caused to pass in succession through the insertion hole135. The suspending support part131is placed in a condition in which it is inserted through the slide hole136of the assembly hole88, and the lid66is then turned in the direction of the arrow a6while the suspending support part131is allowed to slide along the slide hole136as indicated by the arrow a5(also seeFIG. 19).

Subsequently, as shown inFIGS. 19 and 20, the temporary stopper prongs128of the lid66are engaged with and held on the rear edge166of the front undercover47located adjacent to the relief opening56, as indicated by the arrow a7. In this instance, the lateral projections132of each engagement hook85of the lid66are disposed near the wall134(FIG. 18) of the stepped section87but they are not in contact with the wall134.

Finally, the bolts96held in advance on the lid66are threaded into the internal thread portions164of the internal thread members76provided on the undercover fastening section75of the rear undercover48until the bolts96assume the position shown inFIG. 13. Assembly of the lid66is thus completed.

Description will next be made of operation of the lid structure12. In the lid structure12, because the lid66is assembled in the manner as described above, the lid assembling operation is made easier and the assembly time can be reduced.

When the lid66is opened as shown inFIGS. 1 and 14, for the purpose of assembly or maintenance, for example, the engagement hooks85are engaged with and held on the stepped section87of the rear undercover48so that the lid66hangs down from the rear undercover48without detachment. This eliminates the need to manually remove the lid66from the rear undercover48and place the lid66near the human operator. Thus, the maintenance time can be reduced.

During the assembly process, the bolt43and the nut44of the engine front mount31are tightened with a desired toque.

Prior to the assembly process, the engine15is mounted on the front sub-frame25, and the bolt43and the nut44are tightened with a torque which is about half of the desired torque. Subsequently, the undercover16is attached to the front sub-frame25.

Thereafter, the front sub-frame25is lifted upward, and the engine15is fastened to the left and right front side frame23.

Finally, during the assembly process, the lid66is opened and allowed to hand down, as shown inFIGS. 1 and 14. Then, the lid66is turned in the direction of the arrow a8shown inFIG. 14and, thereafter, the bolt43and the nut44of the engine front mount31are tightened until a desired axial force is obtained.

INDUSTRIAL APPLICABILITY

With the arrangements so far described, the present invention can be used advantageously as a lid-fastening structure for an automobile.

REFERENCE SIGNS LIST

11: vehicle12: lid structure13: lid-fastening structure16: undercover17: vehicle body66: lid73: opening (adjustment opening)81: engine room83: one end portion of lid84: opposite end portion of lid85: engagement hook86: edge of lid87: stepped section88: assembly hole91: rib92: inner surface of undercover93: step94: bulged portion95: stepped rib96: bolt101: insertion hole102: circumferential edge of insertion hole103: portion of circumferential edge of insertion hole104: backslide-limiting opening106: circumferential edge of supporting/fastening hole107: portion of circumferential edge of supporting/fastening hole108: supporting/fastening hole111: external thread of bolt112: bearing surface of bolt113: retainer part of bolt115: guide portion116: front side of lid117: back side of lid118: protrusionr: radius of insertion holerh: radius of supporting/fastening holers: radius of retainer part