JP2017065412A - Vehicle understructure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle understructure capable of suppressing destruction of an undercover caused by a load inputted to a service hole cover and falling-off of fastening bolts or screws.SOLUTION: When a load to a vehicle rear side is inputted to a service hole cover 14, a screw 16 moves toward the vehicle rear side in a hole part 32 of a fastened part 20 of an undercover 10, and an end surface 37 of a case nut 18 engaged by the screw 16 is brought into contact with a first rib 28. The end surface 37 and the first rib 28 come into surface-contact with each other, and thus stress applied to the first rib 28 is reduced. In other words, as the strength of the fastened part 20 is set larger than that of a fitting part 40 of the service hole cover 14, only the service hole cover 14 is destroyed when the load is inputted to the service hole cover 14, and destruction of the undercover 10 and falling-off of the screw 16 are suppressed.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vehicle lower structure.

  Conventionally, a service hole for maintenance is formed in the under cover attached to the lower part of the engine room, and the service hole cover is fastened from below the under cover with bolts or screws to close the service hole. .

JP 2006-327429 A

  By the way, when the vehicle rides on the curb and a load is input to the service hole cover, the under cover fastened to the service hole cover may be damaged, and the repair cost may increase. Further, when the service hole cover is dropped from the under cover, the fastening bolts or screws are dropped together with the service hole cover, and the tires of the vehicle may be punctured.

  In consideration of the above-described facts, an object of the present invention is to provide an undercarriage for a vehicle that suppresses breakage of an undercover caused by input of a load to a service hole cover and dropping of a fastening bolt or screw.

  The invention according to claim 1 is attached to the lower part of the engine room, a service hole is formed, and an under cover in which a fastened part is formed around the service hole, and a case attached to the fastened part A nut and a fastening portion are provided, and are made of the same material as the under cover, and a service hole cover that is attached to the under cover and closes the service hole, and is inserted from the fastening portion to the fastened portion, Reinforced portion of the under cover in which the bolt or screw screwed to the case nut is in contact with the end surface of the case nut when a load is input to the service hole cover, and the strength of the fastened portion is higher than the fastening portion And comprising.

  According to this configuration, the bolt or the screw is inserted from the fastening portion of the service hole cover to the fastened portion of the undercover, and the bolt or screw is screwed into the case nut attached to the fastened portion. Service hole cover will be concluded.

  On the other hand, when a load is input to the service hole cover, for example, when the vehicle rides on a curbstone, the load is transmitted from the fastening portion of the service hole cover to the bolt or screw, and the fastening portion of the under cover and the bolt or screw are relatively Moving. At this time, the case nut screwed with the bolt or the screw is also moved relative to the fastening portion, and the end surface of the case nut comes into contact with the reinforcing portion. As a result, the load transmitted from the bolt or screw to the fastened portion is dispersed, and the stress acting on the reinforcing portion is reduced. That is, the stress applied from the case nut, the bolt, or the screw to the fastening portion of the under cover and the fastening portion of the service hole cover made of the same material is smaller in the fastened portion. In other words, the strength of the fastened portion is greater than the strength of the fastened portion of the service hole cover by providing this reinforcing portion in the fastened portion of the under cover. As a result, the fastening portion of the service hole cover is broken before the fastened portion of the under cover is broken by the load input to the service hole cover. Therefore, the destruction of the under cover and the drop of the bolt or screw from the under cover are suppressed.

  Since the vehicle lower structure according to the first aspect of the present invention has the above-described configuration, it is possible to suppress the destruction of the undercover and the drop of the bolt or the screw when the load is input to the service hole cover.

It is an exploded perspective view explaining the lower structure for vehicles concerning one embodiment of the present invention. It is a perspective view which shows the attaching part of the undercover which concerns on one Embodiment of this invention. It is the sectional view on the AA line in FIG. It is a top view of the service hole cover which concerns on other embodiment of this invention.

  A vehicle lower structure according to an embodiment of the present invention will be described with reference to FIGS. In addition, each figure is typical and the illustration with a low relevance to the present invention is omitted. Further, in FIG. 1, an arrow FR indicates the front of the vehicle, an arrow W indicates the vehicle width direction, and an arrow UP indicates the upper side of the vehicle.

(Constitution)
As shown in FIG. 1, the vehicle lower structure according to the present embodiment includes an under cover 10 located below the engine room, a service hole cover 14 that closes an opening 12 of the under cover 10 described later, and a service hole. A screw 16 for fastening the cover 14 to the under cover 10 and a case nut 18 (see FIGS. 2 and 3) provided on the under cover 10 and screwed into the screw are basically provided.

  As shown in FIG. 1, the under cover 10 has a substantially planar shape, and is attached to the body below the engine room. The under cover 10 is made of resin, and a substantially rectangular opening 12 is formed on the vehicle rear side. In the under cover 10, two fastening portions 20 of the screw 16 are provided on the peripheral portion of the opening 12 on the vehicle front side and one on the vehicle rear side. An accommodation portion 22 into which a claw portion 41 of a service hole cover 14 to be described later is inserted is formed on the vehicle rear side of the peripheral portion of the opening portion 12.

  As shown in FIGS. 2 and 3, the fastened portion 20 is a portion protruding upward of the vehicle as compared with the general surface 23 of the undercover 10, and has a vertical wall portion 20 </ b> A and a flat portion 20 </ b> B. The fastened portion 20 is substantially equal to a portion of the undercover 10 surrounded by the vertical wall 24 and the vertical wall 26. As shown in FIG. 2, the vertical wall 24 has a width portion 24A extending in the vehicle width direction, and a front and rear portion 24B extending from the vehicle width direction end portion of the width portion 24A to the vehicle rear side. It is formed in an L shape in view. Further, the vertical wall 26 is formed to extend from the middle of the front and rear portions 24B of the vertical wall 24 to the width portion 24A side in the vehicle width direction.

  In the fastened portion 20, a first rib 28 is formed on the vehicle front side of the vertical wall 26. The first rib 28 extends in the vehicle width direction parallel to the vertical wall 26 and is rectangular when viewed from the vehicle width direction. The first rib 28 comes into contact with an end surface 37 of an upper plate 38A (described later) of the case nut 18 when a load is applied to the service hole cover 14, and is formed at substantially the same height as the upper plate 38A.

  As shown in FIG. 2, the second rib 30 is formed continuously from the vehicle width direction end of the vertical wall 26 to the vehicle front side. The second rib 30 is formed at the end in the vehicle width direction opposite to the front and rear portions 24B of the vertical wall 24, and has a triangular shape when viewed from the vehicle width direction having an inclined portion extending from the top of the vertical wall 26 to the first rib 28. It is a rib.

  Moreover, as shown in FIG. 3, the to-be-fastened part 20 has the hole 32 for screw 16 insertion formed in the center. Further, in the fastened portion 20, a case nut 18 is disposed above the hole portion 32.

  As shown in FIGS. 2 and 3, the case nut 18 includes a sandwiching portion 38 in which a substantially rectangular upper plate 38A and lower plate 38B are connected in a U-shape. As shown in FIG. 3, the sandwiching portion 38 sandwiches the fastened portion 20 of the under cover 10 between the upper plate 38 </ b> A and the lower plate 38 </ b> B. The upper plate 38A is mounted (arranged) in the area surrounded by the one rib 28).

  Further, the case nut 18 includes a cylindrical portion 36 in which a screw hole 34 into which the tip of the screw 16 is screwed is formed at the center portion of the upper plate 38A. Further, the case nut 18 is provided with a convex portion 39 having an outer diameter smaller than that of the cylindrical portion 36 on the lower surface of the upper plate 38A. The convex portion 39 is for positioning the case nut 18 on the fastened portion 20 by being inserted into the hole portion 32 of the fastened portion 20.

  The distance d1 between the end surface 37 of the upper plate 38A on the vehicle rear side and the end surface 28A of the first rib 28 on the vehicle front side in the vehicle front-rear direction is defined by the outer peripheral surface of the convex portion 39 of the case nut 18 and It is set narrower than the interval d2 with the inner peripheral surface of the hole 32.

  As shown in FIG. 1, the service hole cover 14 is formed in a substantially flat plate shape that is slightly larger than the size of the opening 12. The service hole cover 14 is formed of the same resin material as the under cover 10. Three attachment portions 40 corresponding to the fastened portion 20 of the undercover 10 and one claw portion 41 are formed on the peripheral portion of the service hole cover 14. As shown in FIG. 1, the mounting portion 40 is a circular portion in plan view that is formed to protrude above the vehicle from the general surface 42, and includes a vertical wall portion 40 </ b> A and a flat portion 40 </ b> B as shown in FIG. 3. ing. As shown in FIG. 3, a hole 44 for inserting the screw 16 is formed in the central portion of the mounting portion 40.

  Note that the vehicle front side end portion of the service hole cover 14 is in contact with the lower surface of the under cover 10. Further, the lower plate 38B of the case nut 18 is interposed between the fastened portion 20 of the under cover 10 and the mounting portion 40 of the service hole cover 14 as described above. Further, a washer 48 is interposed between the attachment portion 40 and the screw 16.

  In the undercover 10 of the present embodiment, the fastened portion 20 that is a portion defined by the vertical wall portion 20A rising from the general surface 23 and the flat portion 20B extending from the upper end of the vertical wall portion 20A is provided. This corresponds to the fastened portion of the under cover of the present invention. In the service hole cover 14 according to the present embodiment, the mounting portion 40 including the vertical wall portion 40A and the flat surface portion 40B rising from the general surface 42 corresponds to a fastening portion of the service hole cover according to the present invention.

(Action)
The operation of the vehicle lower structure thus configured will be described.
In the vehicle lower structure of the present embodiment, the claw portion 41 of the service hole cover 14 is inserted into the housing portion 22 of the under cover 10 from below the vehicle, the hole portion 44 of the mounting portion 40 of the service hole cover 14, and the under cover 10. The service hole cover 14 is fastened to the under cover 10 by inserting the screw 16 into the hole 32 of the fastened portion 20 and screwing the screw 16 into the screw hole 34 of the case nut 18. As a result, the opening 12 is closed by the service hole cover 14.

  When removing the service hole cover 14 from the under cover 10, the service hole cover 14 can be easily removed from the under cover 10 by removing the screws 16 and then extracting the claw portions 41 from the housing portion 22.

  Next, an operation when a load from the front side of the vehicle to the rear side of the vehicle is input to the service hole cover 14 when the vehicle rides on a curb or the like when moving forward will be described.

  In this case, when a load toward the vehicle rear side is input to the service hole cover 14, a load toward the vehicle rear side acts on the screw 16 that is fastened. Therefore, the screw 16 moves to the vehicle rear side in the hole portion 32 of the fastened portion 20 of the under cover 10. Here, since the interval d1 is narrower than the interval d2, before the convex portion 39 of the case nut 18 into which the screw 16 is screwed contacts the wall surface of the hole 32, the upper plate 38A of the case nut 18 on the vehicle rear side. The end surface 37 of this is in contact with the first rib 28. An end surface 37 extending in the vehicle width direction is formed on the case nut 18 (upper plate 38A) on the vehicle rear side, and an end surface 28A on the vehicle front side extending in the vehicle width direction is also formed on the first rib 28. Since it is formed, the end surface 37 of the case nut 18 is in contact (surface contact) with the end surface 28A of the first rib 28 over the entire surface (full width).

  As a result, compared with the stress acting on the fastened portion 20 by the convex portion 39 of the case nut 18 coming into contact with the hole portion 32 of the fastened portion 20 of the undercover 10, the first end from the end surface 37 of the case nut 18. The stress acting on the end face 28A of the rib 28 is reduced. Therefore, the strength of the fastened portion 20 can be improved.

  The first rib 28 has one end in the vehicle width direction connected to the vertical wall 24 and the other end connected to the second rib 30. Further, the second rib 30 is formed integrally with the vertical wall 26 extending in the vehicle width direction. That is, the fastened part 20 has higher strength.

  Thus, since the strength of the fastened portion 20 of the under cover 10 is higher than the mounting portion 40 of the service hole cover 14 formed of the same material as the under cover 10, When a load is applied to the rear side of the vehicle, the mounting portion 40 is broken by the collision of the screw 16 with the hole 44 of the mounting portion 40 of the service hole cover 14, and the service hole cover 14 falls off the under cover 10. However, when the upper plate 38A (end surface 37) of the case nut 18 is brought into contact with the first rib 28, the destruction of the fastened portion 20 of the under cover 10 is suppressed, and the screw 16 fastened to the case nut 18 is Dropping from the undercover 10 is suppressed.

  That is, even if the vehicle rides on the curb or the like and a load on the rear side of the vehicle is input to the service hole cover 14 and the service hole cover 14 is destroyed and falls off the under cover 10, the under cover 10 itself And the service hole cover 14 can be prevented from falling off the under cover 10 and damaging the vehicle itself or the body of the following vehicle (burst tires).

(Other embodiments)
In the above embodiment, the vertical wall 26, the first rib 28, and the second rib are provided on the fastened portion 20 in order to make a difference in strength between the fastened portion 20 of the undercover 10 and the mounting portion 40 of the service hole cover 14. Although what provided 30 was demonstrated, it is not limited to this.

  For example, as shown in FIG. 3, the strength of the fastened part 20 is further increased by making the plate thickness t1 of the flat part 20B of the fastened part 20 thicker than the plate thickness t2 of the flat part 40B of the fastening part 40. It can be considered that the strength is higher than 40. Even if a load from the vehicle front side to the vehicle rear side is input to the service hole cover 14, the service hole cover 14 is broken, and even if the service hole cover 14 falls off, the fastened portion 20 of the under cover 10 is broken. Thus, the screw 16 is prevented from dropping from the fastened portion 20 together with the service hole cover 14. Moreover, destruction of the undercover 10 itself is also suppressed.

  Alternatively, in the vehicle lower structure, as shown in FIG. 4, it is also conceivable to provide a notch 50 on the vehicle front side of the hole 44 of the service hole cover 14. When a load from the vehicle front side to the vehicle rear side acts on the service hole cover 14, the screw 16 comes into contact with the vehicle front side of the hole 44. As a result, stress concentrates on the notch 50 of the hole 44, and the service hole cover 14 is broken with a lower input load. As a result, the service hole cover 14 is destroyed before the undercover 10 is destroyed, and the falling off of the screw 16 from the undercover 10 is suppressed.

  In the above embodiment, the service hole cover 14 is fastened to the under cover 10 with the screw 16, but may be fastened with a bolt.

10 Undercover 12 Opening (Service Hall)
14 Service hole cover 16 Screw 18 Case nut 20 Fastened part 26 Vertical wall (reinforcement part)
28 1st rib (reinforcement part)
30 2nd rib (reinforcement part)
38A End face 40 Mounting part (fastening part)

Claims (1)

An under cover that is attached to the lower part of the engine room, has a service hole, and has a fastened portion formed around the service hole;
A case nut attached to the fastened portion;
A service hole cover that is provided with a fastening portion, is made of the same material as the under cover, is attached to the under cover and closes the service hole,
A bolt or a screw inserted from the fastening portion into the fastened portion and screwed into the case nut;
A reinforcing part of the under cover in which the end face of the case nut is brought into contact when a load is input to the service hole cover, and the strength of the fastened part is higher than the fastening part,
A vehicle lower structure comprising:

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