Undercover attachment structure

Abstract

Insertion grooves (28) into which mutually opposing sides of an undercover (14) are inserted are formed so as to face one other in lower portions of a pair of side walls (2004) of a battery cover (22) that face one other in the width direction of a vehicle. The insertion grooves (28) are formed between upper flanges (30) and lower flanges (32) that face one other. Spaces between tip ends (3002) of the upper flanges (30) and tip ends (3202) of the lower flanges (32) constitute openings (28A) through which the sides of the undercover (14) are inserted into the insertion grooves (28), and the tip ends (3002) of the upper flanges (30) protrude farther than the tip ends (3202) of the lower flanges (32). The insertion grooves (28) are formed such that, in a state in which the sides of the undercover (14) have been inserted into the insertion grooves (28), vertical displacement of the sides is restricted.

Description

Undercover mounting structure

[0001] The present invention relates to an attachment structure for an undercover that covers the underside of a battery pack.

[0002] In electric vehicles such as electric vehicles and hybrid vehicles that use a motor as a drive source, when a battery pack that supplies power to the motor is located under the vehicle body, an undercover is provided to cover the underside of the battery pack to protect the battery pack from foreign objects such as pebbles, mud, dust, etc. Known undercover mounting structures include one in which the undercover is attached to the underside of the battery pack via multiple fastening members, and one in which both sides of the undercover are engaged with side sills (see Patent Document 1).

[0003] Japanese Patent Application Publication No. 2013-14274

[0004] The undercover is a thin plate made of metal or synthetic resin, and is therefore prone to bending. In recent years, as battery packs have become larger, the undercover has also become larger, making it even more prone to bending. Therefore, workers must install the undercover from below the battery pack while supporting the large, bent undercover, which can be difficult to do, and some kind of improvement is needed. The present invention has been made in consideration of the above circumstances, and aims to provide an undercover installation structure that is advantageous in facilitating installation work and improving work efficiency.

[0005] To achieve the above object, one embodiment of the present invention provides an undercover mounting structure in which a substantially rectangular undercover covering the underside of a battery pack disposed under a vehicle body is attached to the lower part of the vehicle body via a fastener, the undercover having an insertion groove formed in the vehicle body into which one of opposing sides of the undercover is inserted and which restricts vertical displacement of the one side. Another embodiment of the present invention also provides an insertion groove formed in the vehicle body into which the other of the opposing sides of the undercover is inserted and which restricts vertical displacement of the other side. Another embodiment of the present invention also provides an insertion groove formed between opposing upper and lower flanges, an opening between a tip of the upper flange and a tip of the lower flange through which the side of the undercover is inserted into the insertion groove, and the tip of the upper flange protrudes beyond the tip of the lower flange. In one embodiment of the present invention, the insertion groove has a length along the length direction of the side, the undercover has a length along the length direction of the side and a width perpendicular to this length, and guides are provided at both ends of the insertion groove in the length direction to abut against both ends of the length direction of the side of the undercover and to prevent the undercover from tilting in the width direction.In another embodiment of the present invention, the insertion groove is formed between an upper flange and a lower flange facing each other, the space between the upper flange and the lower flange is formed with a dimension larger than the thickness of the undercover, and protrusions are provided on the side that abut against the upper flange and the lower flange when the side is inserted into the insertion groove and prevent the side from moving in the thickness direction of the undercover and in the direction perpendicular to the thickness direction.In addition, one embodiment of the present invention is characterized in that the insertion groove has a length along the length direction of the side, the undercover has a length along the length direction of the side and a width perpendicular to the length, a vehicle body side temporary fastening portion is provided at a location on the lower part of the vehicle body opposite the center of the undercover in the length and width directions, and a cover side temporary fastening portion is provided at the center of the undercover in the length and width directions, which is releasably connected to the vehicle body side temporary fastening portion to temporarily fasten the undercover.

[0006] According to one embodiment of the present invention, an insertion groove into which one of the opposing sides of the undercover is inserted and which restricts vertical displacement of the one side is provided on the vehicle body. Therefore, when installing the undercover, by inserting one side of the undercover into the insertion groove, even a large undercover can be easily installed by one person, which is advantageous in improving the efficiency of the undercover installation work. Furthermore, because the side of the undercover can be supported by the insertion groove, the number of fasteners used to install the undercover to the vehicle body can be reduced, which is advantageous in reducing parts costs. Furthermore, if an insertion groove into which the other side of the undercover is inserted and which restricts vertical displacement of the other side is provided on the vehicle body, even a large undercover can be easily installed by one person, which is advantageous in improving the efficiency of the undercover installation work. Furthermore, an opening is formed between the tip of the upper flange and the tip of the lower flange through which the edge of the undercover is inserted into the insertion groove. If the tip of the upper flange protrudes beyond the tip of the lower flange, the tip of the upper flange can be used as a guide during insertion, making it easy to insert the edge of the undercover into the insertion groove from the opening, which is advantageous for improving the efficiency of the undercover installation work. Furthermore, if guides are provided at both ends of the length of the insertion groove to abut against both ends of the length of the edge of the undercover and prevent the undercover from tipping over in the width direction, the guides abut against both ends of the length of the edge of the undercover when inserting the edge of the undercover into the insertion groove, allowing the edge of the undercover to be positioned in the length direction, which makes it easy to install the undercover and is advantageous for improving the efficiency of the undercover installation work. Furthermore, the guides ensure the strength of the insertion groove, which is advantageous for protecting the insertion groove from the weight of the battery pack.Furthermore, if the edges are provided with protrusions that abut against the upper and lower flanges when the edges are inserted into the insertion grooves and that suppress movement of the edges in the thickness direction of the undercover and in the direction perpendicular to the thickness direction, movement of the edges in the thickness direction of the undercover and in the direction perpendicular to the thickness direction is suppressed, and therefore the undercover is more reliably supported via the insertion grooves and the protrusions when inserted into the insertion grooves, making it easier for one person to install an enlarged undercover, which is advantageous in terms of improving the efficiency of the undercover installation work.Furthermore, since vibration of the undercover while the vehicle is traveling can be suppressed, this is advantageous in ensuring quietness and livability in the vehicle interior and improving occupant comfort. Furthermore, if a vehicle body side temporary fastening portion is provided at the lower part of the vehicle body at a location opposite the center of the length and width of the undercover, and a cover side temporary fastening portion is provided at the center of the length and width of the undercover that can be engaged and detached with the vehicle body side temporary fastening portion to temporarily fasten the undercover, the undercover installation work can be facilitated without the need for any dedicated jig for temporary fastening, which is advantageous in improving the efficiency of the undercover installation work.

[0007] FIG. 3(A) is a cross-sectional view of the undercover mounting structure according to the first embodiment, taken along a cross section perpendicular to the vehicle longitudinal direction. FIG. 3(B) is a bottom view of the undercover mounting structure according to the first embodiment, as viewed from below. FIG. 3(A) is a bottom view of the undercover mounting structure according to the second embodiment, as viewed from below, and FIG. 3(B) is a cross-sectional view taken along line A-A in FIG. 3(A). FIG. 3(A) is a perspective view of the undercover according to the third embodiment. FIG. 5(A) and (B) are cross-sectional views showing the state in which the long sides of the undercover are inserted into the insertion grooves in the undercover mounting structure according to the third embodiment, with FIG. 5(A) showing a case in which the protrusion is formed as a curved portion, and FIG. 5(B) showing a case in which the protrusion is formed as a bulged portion. FIG. 3(B) is a bottom view of the undercover mounting structure according to the fourth embodiment, as viewed from below. FIG. 3(B) is a cross-sectional view showing a modified example of the fourth embodiment.

[0008] First Embodiment A first embodiment of the present invention will be described below with reference to the drawings. The undercover mounting structure of this embodiment is applied to a battery pack that is mounted on an electric vehicle using only a motor as a drive source, a hybrid vehicle, or an electric vehicle using a motor as a drive source, such as a plug-in hybrid vehicle that can be externally charged or externally powered, and that supplies power to the motor.

[0009] As shown in FIG. 1 , a battery pack 12 is disposed under a vehicle body 10, and an undercover 14 is provided under the vehicle body 10 to cover the underside of the battery pack 12. In the following drawings, the symbol UP indicates the upper side of the vehicle, the symbol FR indicates the front side of the vehicle, and the symbol RH indicates the width direction of the vehicle. The battery pack 12 includes a battery case 16, a battery pack 18 consisting of multiple battery modules housed in the battery case 16, a control device (not shown) that controls the battery pack 18, a DC / DC converter (not shown), a cooling device (not shown) that cools the battery modules, and the like. The battery case 16 is made of metal and includes a battery tray 20 and a battery cover 22. The battery tray 20 includes a rectangular bottom wall 2002 in a plan view and four side walls 2004 extending from the four sides of the bottom wall 2002. The battery pack 18, the control device, the DC / DC converter, and the cooling device are attached to the bottom wall 2002.

[0010] A pair of long sides of the bottom wall 2002 of the battery tray 20 is arranged along the front-to-rear direction of the vehicle, and a pair of short sides of the bottom wall 2002 is arranged along the vehicle width direction. The battery cover 22 includes an upper wall 2202 that is rectangular in plan view and faces the bottom wall 2002, four side walls 2204 that extend perpendicularly from the four sides of the upper wall 2202, and rectangular frame-shaped flanges 2206 that are provided on the outer peripheries of the lower ends of the side walls 2204. The battery cover 22 and the battery tray 20 are fastened together with a plurality of bolts B1, with the flanges 2206 of the battery cover 22 overlapping the upper ends of the side walls 2004 of the battery tray 20. The battery tray 20 is arranged in the center of the vehicle width direction and is attached to a pair of side members 24 via mounting portions 2010 and bolts B2 provided on a pair of side walls 2004 that face each other in the vehicle width direction. In the drawing, reference numeral 26 denotes a floor panel extending in the longitudinal direction and the width direction of the vehicle, and the upper ends of a pair of side members 24 are joined to the lower surface of the floor panel 26 on both sides in the width direction of the vehicle.

[0011] Opposing insertion grooves 28, into which opposing edges of the undercover 14 are inserted, are formed in the lower portions of a pair of side walls 2004 of the battery cover 22 that face each other in the vehicle width direction. The insertion grooves 28 are formed between the opposing upper flange 30 and lower flange 32. An opening 28A is formed between the tip 3002 of the upper flange 30 and the tip 3202 of the lower flange 32, into which the edge of the undercover 14 is inserted, and the tip 3002 of the upper flange 30 protrudes beyond the tip 3202 of the lower flange 32. The insertion grooves 28 are formed to restrict vertical displacement of the edge of the undercover 14 when inserted therein, and in FIG. 1 , reference numeral 33 denotes the back wall of the insertion groove 28.

[0012] As shown in FIG. 2 , the undercover 14 has a rectangular shape. When the undercover 14 is attached to the lower part of the vehicle body 10, a pair of long sides 1402 of the undercover 14 are aligned along the fore-and-aft direction of the vehicle, and a pair of short sides 1404 of the undercover 14 are aligned along the vehicle width direction. Therefore, the undercover 14 has a length extending in the fore-and-aft direction of the vehicle and a width extending in the vehicle width direction. In this embodiment, the long sides 1402 of the undercover 14 are inserted into the insertion grooves 28. Due to the increased size of the battery pack 12, the length of the undercover 14 is, for example, approximately 3 m and the width is approximately 2 m. A plurality of mounting holes 1410 are provided at the center of the width direction of the undercover 14, spaced apart along the length of the undercover 14. As shown in FIG. 1 , a plurality of stud bolts 34 are provided in the bottom wall 2002 of the battery tray 20, which is the underside of the vehicle body 10, corresponding to the plurality of mounting holes 1410.

[0013] Next, the installation of the undercover 14 will be described. With the vehicle raised upward with a jack, the worker lifts the center of the length of the undercover 14 from below, inserts one long side 1402 of the undercover 14 into one of the insertion grooves 28, and then inserts the other long side 1402 into the other insertion groove 28. Then, the worker presses the center of the length of the undercover 14, which has been bent downward, against the underside of the bottom wall 2002 of the battery tray 20, inserts the stud bolts 34 into the mounting holes 1410, and tightens the nuts 36 onto the stud bolts 34, thereby completing the installation of the undercover 14.

[0014] Therefore, according to this embodiment, the installation work of an enlarged undercover 14 can be easily performed by one person, thereby improving the efficiency of the installation work of the undercover 14. Furthermore, because the long side 1402 of the undercover 14 can be supported by the insertion groove 28, the number of stud bolts 34 and nuts 36, which are fasteners for attaching the undercover 14 to the battery tray 20 of the battery pack 12, can be reduced, which is advantageous in reducing parts costs. Furthermore, in this embodiment, the opening 28A through which the side of the undercover 14 is inserted into the insertion groove 28 is formed between the tip 3002 of the upper flange 30 and the tip 3202 of the lower flange 32. Since the tip 3002 of the upper flange 30 protrudes beyond the tip 3202 of the lower flange 32, the tip 3002 of the upper flange 30 can be used as a guide during insertion. Therefore, the long side 1402 of the undercover 14 can be easily inserted from the opening 28A into the insertion groove 28, which is more advantageous in improving the efficiency of the installation work of the undercover 14.

[0015] Second Embodiment Next, a second embodiment will be described with reference to FIGS. 3A and 3B. In the following embodiments, portions and members similar to those of the first embodiment are denoted by the same reference numerals, and their description will be omitted. The following description will focus on the differences. As shown in FIGS. 3A and 3B, a vehicle-body temporary fastening portion is provided in place of the stud bolt 34 on the bottom wall 2002 of the battery tray 20, which is the lower part of the vehicle body 10, at a location facing the center of the undercover 14 in the longitudinal and width directions. The vehicle-body temporary fastening portion is formed by a temporary fastening hole 2020. A cover-side temporary fastening portion is provided in the center of the undercover 14 in the longitudinal and width directions. The cover-side temporary fastening portion is formed by a temporary fastening pin 38 that is releasably coupled to the vehicle-body temporary fastening portion. According to the second embodiment, when attaching the undercover 14, the worker lifts the center of the undercover 14 in the longitudinal direction from below, inserts one long side 1402 of the undercover 14 into one of the insertion grooves 28, and then inserts the other long side 1402 into the other insertion groove 28. Next, by pressing the center of the longitudinal direction of the undercover 14, which has been bent downward, against the underside of the bottom wall 2002 of the battery tray 20, the temporary fixing pins 38 can be engaged with the temporary fixing holes 2020, thereby temporarily fixing the undercover 14 to the battery tray 20. Therefore, with the undercover 14 temporarily fixed, the stud bolts 34 can be inserted into the mounting holes 1410 and the nuts 36 can be fastened to the stud bolts 34. This eliminates the need for any dedicated jig for temporary fixation, facilitating the installation of the undercover 14 and advantageously improving the efficiency of the installation of the undercover 14. It is also possible to arbitrarily form the vehicle body side temporary fastening portion with a temporary fastening pin and the cover side temporary fastening portion with a temporary fastening hole.

[0016] Third Embodiment Next, a third embodiment will be described with reference to FIGS. 4, 5A, and 5B. As shown in FIGS. 5A and 5B, the space between the upper flange 30 and the lower flange 32 that define the insertion groove 28 is larger than the thickness of the undercover 14. As shown in FIGS. 4, 5A, and 5B, a protrusion 40 is provided on a long side 1402 of the undercover 14. The protrusion 40 abuts against the upper flange 30 and the lower flange 32 when the long side 1402 is inserted into the insertion groove 28, suppressing movement of the long side 1402 in the thickness direction of the undercover 14 and in a direction perpendicular to the thickness direction. The protrusions 40 are provided at multiple locations spaced apart along the length of the undercover 14. FIG. 4A shows a case in which the protrusion 40 is formed as a curved portion that protrudes toward one side in the thickness direction of the undercover 14 and extends along the length of the undercover 14. FIG. 4B shows a case in which the protrusion 40 is formed as a bulge that protrudes toward one side in the thickness direction of the undercover 14. According to the third embodiment, the protrusions 40 abut against the upper flange 30 and the lower flange 32, suppressing movement of the long side 1402 of the undercover 14 in the thickness direction and in the direction perpendicular to the thickness direction, and therefore, when the undercover 14 is inserted into the insertion groove 28, the undercover 14 is more reliably supported via the insertion groove 28 and the protrusions 40, making it easier for one person to install a larger undercover 14, which is advantageous in improving the efficiency of the installation work of the undercover 14. Furthermore, because the protrusions 40 suppress movement of the undercover 14 in the thickness direction and in the direction perpendicular to the thickness direction, vibration of the undercover 14 while the vehicle is traveling can be suppressed, which is advantageous in ensuring quietness and livability in the vehicle interior and improving comfort for occupants.

[0017] Fourth Embodiment Next, a fourth embodiment will be described with reference to FIG. 6 . In the fourth embodiment, guides 42 are provided at both longitudinal ends of the insertion groove 28. The guides 42 abut against both longitudinal ends of the long side 1402 of the undercover 14 to prevent the undercover 14 from tipping over in the width direction, and the tips of the guides 42 are formed with inclined surfaces 4202 for smoothly guiding the undercover 14 into the insertion groove 28. According to the fourth embodiment, when the long side 1402 of the undercover 14 is inserted into the insertion groove 28, the guides 42 abut against both longitudinal ends of the long side 1402 of the undercover 14, thereby enabling the long side 1402 of the undercover 14 to be positioned in the longitudinal direction. This allows the stud bolts 34 to be easily inserted into the mounting holes 1410 of the undercover 14, facilitating the installation of the undercover 14 and advantageously improving the efficiency of the installation of the undercover 14. Furthermore, when performing maintenance such as replacing the battery assembly 18 in the battery pack 12 at a repair shop or the like, the battery pack 12 is removed from the vehicle body 10 and placed on a workbench or floor, and the weight of the battery pack 12 is applied to the lower flange 32, which defines the insertion groove 28. In this embodiment, the strength of the lower flange 32 is ensured by the guide 42, which is advantageous in protecting the lower flange 32 from the weight of the battery pack 12. In this case, as shown in FIG. 7 , a protrusion 44 may be provided that protrudes downward from the underside of the lower flange 32. Providing the protrusion 44 separates the underside of the lower flange 32 upward from the floor, which is more advantageous in protecting the lower flange 32 from the weight of the battery pack 12.

[0018] In the embodiment, the location of the vehicle body 10 where the insertion groove 28 is provided is the lower portion of the side wall 2004 of the battery tray 20. However, the location of the vehicle body 10 where the insertion groove 28 is provided may include frame members such as the side members 24, and members and parts attached to these frame members, and therefore is not limited to the battery tray 20 of the battery pack 12 as in the embodiment. Furthermore, if the location of the vehicle body 10 where the insertion groove 28 is provided is the bottom wall 2002 of the battery tray 20, the upper flange 30 is also used as the bottom wall 2002, so the upper flange 30 may be omitted and only the lower flange 32 may be provided. Furthermore, in the embodiment, the case where a pair of opposing long sides 1402 of the undercover 14 are respectively provided with insertion grooves 28 into which the pair of long sides 1402 are inserted has been described. However, a single insertion groove 28 may be provided and one of the pair of long sides 1402 may be inserted into this insertion groove 28. However, if two insertion grooves 28 are provided and a pair of long sides 1402 are inserted into the insertion grooves 28, as in the embodiment, the installation work of the enlarged undercover 14 can be easily performed by one person, which is more advantageous in terms of improving the efficiency of the installation work of the undercover 14.

[0019] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0020] This application is based on a Japanese patent application (Patent Application No. 2023-173433) filed on October 5, 2023, the contents of which are incorporated herein by reference.

[0021] REFERENCE SIGNS LIST 10 Vehicle body 12 Battery pack 14 Under cover 1402 Long side 1404 Short side 1410 Mounting hole 16 Battery case 18 Assembled battery 20 Battery tray 2002 Bottom wall 2004 Side wall 2010 Mounting portion 2020 Temporary fixing hole (vehicle body side temporary fixing portion) 22 Battery cover 2202 Upper wall 2204 Side wall 2206 Flange 24 Side member 26 Floor panel 28 Insertion groove 28A Opening 30 Upper flange 3002 Tip 32 Lower flange 3202 Tip 33 Back wall 34 Stud bolt (fastener) 36 Nut (fastener) 38 Temporary fixing pin (cover side temporary fixing portion) 40 Protrusion 42 Guide 4202 Inclined surface 44 Protruding portion B1, B2 bolts

Claims

1. An undercover mounting structure in which a substantially rectangular undercover covering the underside of a battery pack arranged at the bottom of a vehicle body is mounted to the bottom of the vehicle body via fasteners, wherein an insertion groove into which one of two opposing sides of the undercover is inserted and which restricts vertical displacement of the one side is provided on the vehicle body.

2. The undercover mounting structure according to claim 1, characterized in that an insertion groove is provided on the vehicle body into which the other of the opposing sides of the undercover is inserted, and which restricts vertical displacement of the other side.

3. The undercover mounting structure according to claim 1 or 2, characterized in that the insertion groove is formed between an upper flange and a lower flange facing each other, an opening is formed between the tip of the upper flange and the tip of the lower flange through which the edge of the undercover is inserted into the insertion groove, and the tip of the upper flange protrudes beyond the tip of the lower flange.

4. An undercover mounting structure as described in claim 1 or 2, characterized in that the insertion groove has a length along the length direction of the side, the undercover has a length along the length direction of the side and a width perpendicular to said length, and guides are provided at both ends of the length direction of the insertion groove to abut against both ends of the length direction of the side of the undercover and prevent the undercover from falling in the width direction.

5. An undercover mounting structure as described in claim 1 or 2, characterized in that the insertion groove is formed between an upper flange and a lower flange facing each other, the space between the upper flange and the lower flange is formed with a dimension larger than the thickness of the undercover, and a protrusion is provided on the edge that abuts against the upper flange and the lower flange when the edge is inserted into the insertion groove and suppresses movement of the edge in the thickness direction of the undercover and in a direction perpendicular to the thickness direction.

6. The undercover mounting structure as described in claim 1 or 2, characterized in that: the insertion groove has a length along the length direction of the side; the undercover has a length along the length direction of the side and a width perpendicular to said length; a vehicle body side temporary fastening portion is provided on the lower part of the vehicle body at a location facing the center of the length and width directions of the undercover; and a cover side temporary fastening portion is provided at the center of the length and width directions of the undercover, which is releasably connected to the vehicle body side temporary fastening portion to temporarily fasten the undercover.

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