JP2006315627A - Floor panel of vehicle body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the acoustic radiation from a floor panel by reducing effectively the vibratory energy of the floor panel originating from the vibration transmitted from frame members of the body even if the shape of the floor panel involves a certain restriction over the height direction. <P>SOLUTION: The floor panel 2 etc. of the vehicle body to constitute a vehicle floor while it is coupled with frame members 20, 22, 27, 28 etc., arranged in the fore and aft direction of the vehicle body and in the vehicle width direction, is equipped with a high rigidity portion 70 formed in the central part of a region S1 etc. surrounded by the frame members in such a way as protruding up or down and a low rigidity portion 72 formed flat around the high rigidity portion, wherein the high rigidity portion is furnished with a recess 70b consisting of a curved surface having a circular or an elliptical shape when viewed on the plan as protruding in a curved surface oppositely to the protruding direction in the central part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a floor panel for a vehicle body, and more particularly to a floor panel for a vehicle body that is connected to a frame member disposed in the longitudinal direction of the vehicle body and the vehicle width direction and constitutes the floor of an automobile.

  It is known that the vibrations of the engine and the suspension are transmitted to the floor panel via the frame member, and the floor panel vibrates to generate uncomfortable vehicle interior vibration and noise. Such unpleasant vibration transmitted from the engine or suspension is mainly 400 Hz or less in an automobile, and has a peak at a frequency around 250 Hz, which is road noise caused by tire cavity resonance.

  Conventionally, in order to suppress such vibration noise, it is generally performed to attach a vibration damping material or a vibration damping material to each part of the floor panel and the vehicle body in the vicinity thereof. However, this method requires a very large amount of vibration damping materials and vibration damping materials, and thus has a problem that the vehicle weight increases and the cost also increases. It is also known to increase the rigidity by forming a large number of beads on the floor panel or increasing the panel thickness, thereby shifting the natural frequency of the floor panel to a high band higher than 400 Hz. This method has the advantage of suppressing the resonance peak in the low frequency region, but on the other hand, the vibration in the high frequency region increases on the contrary. Needed a lot and had similar problems.

Also, the floor panel is formed with a plurality of shell structure convex portions that are resistant to bending, compression, and tension, and concave portions extending vertically and horizontally between these convex portions, and a vibration damping material is provided in the concave portions, and concentrated in the concave portions. A panel structure is known in which the generated vibration is attenuated by a damping material (Patent Document 1). In this panel structure, a concave portion is formed between a plurality of convex portions so as to extend vertically and horizontally like a mesh, thereby increasing a vibration energy loss coefficient with respect to bending deformation in all directions.
The applicant has proposed a floor panel structure described in Patent Document 2.

JP-A-6-107235 Japanese Patent Application Laid-Open No. 2004-237871

  Here, when the panel structure of Patent Document 1 is applied to the region surrounded by the frame member of the floor panel, there are a plurality of convex portions, or the concave portions extend vertically and horizontally like a mesh, Vibration and noise cannot be reduced sufficiently. For example, when vibration energy flows into the floor panel from the four sides via the frame member, there is a problem that if there are a plurality of protrusions, vibrations are less likely to concentrate in the recesses, and vibration distortion is dispersed throughout the panel area due to the recesses. There is a problem that the entire panel area is likely to vibrate. On the other hand, in terms of manufacturing, there is also a problem that the cost increases when the damping material is provided in the vertical and horizontal directions like the mesh in accordance with the concave portion.

  On the other hand, the present applicant forms a high-rigidity portion that protrudes upward or downward in the center of the area of the floor panel surrounded by a plurality of frame members, and is flat and low-rigidity in the entire area around the high-rigidity portion. The floor panel structure which formed the part is proposed (patent document 2). According to this floor panel structure, by forming one high-rigidity portion at the center of the region, there is an advantage that vibration can be effectively concentrated on the low-rigidity portion, and without the above-described problems, Vibration and noise can be reduced.

  However, even the floor panel structure shown in Patent Document 2 has the following cases in which it is difficult to reduce vibration and noise. That is, when the high rigidity part is formed by protruding the floor panel itself upward or downward, the protrusion height of the high rigidity part is the exhaust pipe or auxiliary equipment disposed below or above the vehicle body of the floor panel. It is necessary to suppress the height so as not to interfere with the height of the passenger or to prevent the passenger from stepping on the foot comfort (such as the occupant feeling a sense of incongruity by feeling a dent or the like). However, the smaller the protrusion height is, the more difficult it is to sufficiently increase the rigidity of the high-rigidity part. In such a case, vibration is less likely to concentrate on the low-rigidity part. Such a problem is particularly noticeable when the area surrounded by the frame member is relatively large or rectangular.

  In addition, from the viewpoint of securing the foot comfort of passengers, even if the height of the high-rigidity part is increased, a thick carpet that has been hollowed out according to its shape is laid, or the high-rigidity part is filled with urethane, etc. It is conceivable to secure the treading feeling by passing another steel plate member above the floor panel. However, in these cases, there are problems in terms of increase in vehicle weight and cost.

  Therefore, the present invention has been made to solve the above-described problems of the prior art, and even if the floor panel shape is restricted in the height direction, the floor panel is caused by vibration transmitted from the frame member of the vehicle body. It is an object of the present invention to provide a floor panel for a vehicle body that can effectively reduce vibration energy and reduce acoustic radiation from the floor panel.

In order to achieve the above object, the present invention relates to a floor panel of a vehicle body that is connected to a frame member disposed in the longitudinal direction of the vehicle body and in the vehicle width direction and constitutes the floor of an automobile, and is an area surrounded by the frame member A high-rigidity part that protrudes upward or downward from the center of the high-rigidity part, and a low-rigidity part that is formed flat around the high-rigidity part. Thus, it protrudes in a curved shape in a direction opposite to the protruding direction, and is formed with a circular or oval curved concave portion in plan view.
In the present invention configured as described above, since the high-rigidity portion and the low-rigidity portion are provided, the vibration energy concentrates on the low-rigidity portion due to the difference in stiffness between them. In the low-rigidity portion, the vibration energy of the floor panel is reduced by the large vibration distortion caused by the concentrated vibration energy and the damping ability of the material (steel plate) constituting the floor panel itself. In addition, since the high-rigidity part is formed at the center of the region surrounded by the frame member and the low-rigidity part is formed around the high-rigidity part, vibration is effectively concentrated on the low-rigidity part and greatly distorted. The vibration transmitted to the high-rigidity portion is effectively cut off by the low-rigidity portion, and the vibration energy of the vibration transmitted to the floor panel via the frame member is reduced without being distributed to the entire floor panel. As a result, acoustic radiation from the floor panel can be more reliably reduced.
Furthermore, in the present invention, since the curved portion is formed in the highly rigid portion, the rigidity of the highly rigid portion can be greatly increased. That is, the curved concave portion has a high rigidity by projecting in a curved shape, and its peripheral portion extends in a curved shape when formed in a circular shape or an elliptical shape in plan view. The rigidity in all directions including the vehicle body longitudinal direction and the vehicle width direction can be increased. Further, since the curved concave portion protrudes in the direction opposite to the protruding direction of the high-rigidity portion, the height of the high-rigidity portion can be kept small. Therefore, the curved concave portion does not interfere with exhaust pipes and auxiliary equipment provided below and above the vehicle body of the floor panel, or without deteriorating the feeling of stepping on the passenger, A rigidity difference from the low rigidity portion can be obtained with certainty. As a result, even if there is a restriction in the height direction on the floor panel shape, the acoustic radiation from the floor panel due to vibration transmitted from the frame member of the vehicle body can be reduced.

In the present invention, the curved concave portion preferably has a continuous curvature over the entire surface.
In the present invention configured as described above, since the curvature is continuous over the entire surface of the curved concave portion, the rigidity of the high-rigidity portion can be more reliably increased.

In the present invention, preferably, the high-rigidity portion protrudes upward, and the curved concave portion of the high-rigidity portion protrudes downward with a protrusion height smaller than the protrusion height of the high-rigidity portion.
In the present invention configured as described above, the curved concave portion protrudes downward with respect to the high-rigidity portion protruding upward, and the protrusion height is smaller than the protrusion height of the high-rigidity portion. Interference with the exhaust pipe and the like can be prevented more reliably.

In the present invention, preferably, the protruding height of the high-rigidity portion from the low-rigidity portion is 10 mm or less.
In this invention comprised in this way, it can prevent more reliably that the step comfort of a passenger | crew deteriorates.

In the present invention, it is preferable that a groove portion extending so as to communicate the curved concave portion and the low rigidity portion is further formed in the high rigidity portion.
In the present invention configured as described above, since the groove portion is formed, the rigidity of the highly rigid portion can be increased with respect to the direction in which the groove portion extends. In particular, since the groove portion extends so as to communicate the curved concave portion and the low-rigidity portion, the rigidity of the high-rigidity portion can be more reliably increased.

In the present invention, preferably, the highly rigid portion is further formed with a groove portion extending radially with respect to the curved concave portion.
In the present invention configured as described above, since the groove portion is formed, the rigidity of the highly rigid portion can be increased with respect to the direction in which the groove portion extends. In particular, since the groove portion extends radially with respect to the curved concave portion, the rigidity of the high-rigidity portion can be more reliably increased.

In the present invention, preferably, the high-rigidity portion is formed with a corrugated portion constituted by at least two curved surface portions, and the curved concave portion of the high-rigidity portion is formed between the curved surface portions of the corrugated portion. ing.
In the present invention configured as described above, the rigidity of the high-rigidity portion can be more reliably increased by the corrugated portion and the curved concave portion formed between the curved surface portions of the corrugated portion.

In the present invention, preferably, the high-rigidity part is formed in a rectangular shape, and two curved surface parts of the wave-shaped part are formed side by side in the longitudinal direction of the rectangular high-rigidity part.
In the present invention configured as described above, since the curved surface portions of the corrugated portion are arranged in the longitudinal direction of the highly rigid portion formed in a rectangular shape, the rigidity in the longitudinal direction of the highly rigid portion can be reliably increased. Furthermore, by forming the curved concave portion between the curved surface portions, the rigidity in the longitudinal direction of the high-rigidity portion can be more reliably increased.

In order to achieve the above object, the present invention is a vehicle body floor panel which is connected to a frame member disposed in the longitudinal direction of the vehicle body and in the vehicle width direction and forms the floor of an automobile, and is surrounded by the frame member. A high-rigidity portion formed at the center of the region, and a low-rigidity portion formed flat around the high-rigidity portion, and the high-rigidity portion includes at least two curved surface portions. Further, the corrugated portion is formed, and further, a curved concave portion having a circular shape or an elliptical shape in a plan view is formed so as to protrude upward or downward in a curved shape across the curved surface portions of the corrugated portion. Yes.
In the present invention configured as described above, the high rigidity portion formed at the center of the region surrounded by the frame member and the low rigidity portion formed around the high rigidity portion are transmitted to the floor panel via the frame member. The vibration energy of the generated vibration is greatly distorted due to the effective concentration of vibration in the low-rigidity part, and the vibration transmitted to the high-rigidity part is effectively cut off in the low-rigidity part, and further through the frame member Thus, vibration energy of vibration transmitted to the floor panel is reduced without being distributed to the entire floor panel. Furthermore, the rigidity of the high-rigidity portion can be more reliably increased by the corrugated portion and the curved concave portion. That is, since the curved concave portion protrudes in a curved shape upward or downward and has a circular shape or an elliptical shape in plan view, the rigidity of the high rigidity portion in all directions including the vehicle body longitudinal direction and the vehicle width direction can be increased. Furthermore, since the curved concave portion is formed between the curved surface portions of the corrugated portion, the rigidity in the direction in which the corrugated portion extends can be more reliably increased. Therefore, according to the present invention, even if the height of the high-rigidity portion is not increased, the rigidity thereof can be greatly increased. As a result, the exhaust pipes and accessories provided below and above the vehicle body of the floor panel The above-described rigidity difference between the high-rigidity portion and the low-rigidity portion can be reliably obtained without interfering with the above-mentioned or without deteriorating the feeling of stepping on the occupant. As a result, even if there is a restriction in the height direction on the floor panel shape, the acoustic radiation from the floor panel due to vibration transmitted from the frame member of the vehicle body can be reduced.

  According to the present invention, even if the floor panel shape is restricted in the height direction, the vibration energy of the floor panel due to the vibration transmitted from the frame member of the vehicle body is effectively reduced, and the acoustic radiation from the floor panel is reduced. be able to.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a perspective view showing an underbody of an automobile provided with a floor panel according to an embodiment of the present invention. As shown in FIG. 1, an underbody 1 of an automobile includes a plurality of floor panels 2, 4, 6, 8, 10, 12, 14, and 16 that form a floor portion (floor portion) of a passenger compartment, and these floors. And a plurality of frame members connected to the panel. The plurality of frame members include a front side frame 18, a side sill 20, a floor side frame 22, a rear side frame 24, and a No. 1 to No. No. 9 cross members 26 to 34, No. 9 provided between these cross members and extending in the longitudinal direction of the vehicle body. 1 to No. Three tunnel side members 36-38.

First, the frame member will be described with reference to FIG. A pair of front side frames 18 having a closed cross-sectional structure extending in the longitudinal direction of the vehicle body so as to surround the engine room from both the left and right sides are provided at a front portion of the underbody 1 of the automobile. These front side frames 18 have a closed cross-section No. at the front end of the vehicle body. One cross member 26 is joined, and an engine 40 and a front suspension cross member 42 are attached to the front side frame 18, and a front suspension 44 is attached to the front suspension cross member 42.
The rear end portions of the pair of front side frames 18 are No. 1 extending in the vehicle width direction at the end portion of the floor portion on the vehicle body front side. 2 It is joined to the cross member 27. This No. The two cross members 27 are attached to a downward inclined portion of a dash panel (not shown) that partitions the vehicle compartment and the engine compartment, and a pair of torque box members 27a having a closed cross-sectional structure provided outside the vehicle body of each front side frame 18. And a dash lower cross member 27b having a closed cross-sectional structure disposed so as to be sandwiched between the front side frames 18.

  This No. 2 The pair of side sills 20 provided on the floor portion behind the vehicle body from the cross member 27 has a closed cross-sectional structure, and the front end portion thereof is No.2. The two cross members 27 are joined to both ends in the vehicle width direction. A pair of U-shaped floor side frames 22 extending in the longitudinal direction of the vehicle body are provided between the side sills 20, and the front end portions of the floor side frames 22 are connected to the rear end portions of the front side frames 18. In addition to being joined, 2 It is joined to the cross member 27. These floor side frames 22 are No. 3 cross member 28 and no. 4 so that it protrudes inward in the vehicle width direction between the cross member 29 and 22a. The connecting portion 30a with the 5 cross member 30 is bent in the vehicle width direction, and the other portions extend linearly.

  The rear end portions of the floor side frames 22 are joined to the front end portions of the rear side frames 24 each having a U-shaped cross section and extending in the longitudinal direction of the vehicle body. Further, the front end portions of these rear side frames 24 bend outward in the vehicle width direction, and are also joined to the inner side surface of the side sill 20 in the vehicle width direction. The front end portion has a reinforcing member extending in the vehicle width direction. 24a is provided. These rear side frames 24 extend to the end edge of the floor portion on the rear side of the vehicle body. No. 7 cross member 32 and No. 7 A rear suspension cross member 46 is attached between the eight cross members 33 and a rear suspension 48 is attached to the rear suspension cross member 46.

  No. No. 2 on the vehicle body rear side of the cross member 27. 2 extends in a straight line in the vehicle width direction parallel to the cross member 27. Three cross members 28 are provided. This No. The three cross members 28 are joined to the side sills 20 at both left and right ends in the vehicle width direction, and intersect the floor side frame 22 and are joined to the floor side frame 22 on both the left and right sides in the vehicle width direction. This No. No. 3 on the vehicle body rear side of the cross member 28. No. 3 which extends linearly in the vehicle width direction parallel to the cross member 28 Four cross members 29 are provided, and both left and right end portions in the vehicle width direction are joined to the side sill 20. No. The four cross members 29 intersect with the floor side frame 22 on both the left and right sides in the vehicle width direction and are joined to the floor side frame 22. These No. 3 and no. The four cross members 28 and 29 protrude upward at a substantially central position in the vehicle width direction where the floor tunnel portion 50 is provided.

No. No. 4 on the vehicle body rear side of the cross member 29. 5 to No. 7 cross members 30, 31, and 32 are provided, and the cross members 30 to 32 extend linearly in the vehicle width direction in parallel to each other. No. The left and right ends of the cross member 30 in the vehicle width direction are joined to the floor side frame 22 respectively. 6 and no. The left and right ends in the vehicle width direction of the seven cross members 31 and 32 are joined to the rear side frame 24, respectively. No. 7 on the rear side of the vehicle body of the cross member 32, the center of the vehicle width direction is curved forward. Eight cross members 33 are provided so as to extend in the vehicle width direction, and left and right end portions in the vehicle width direction are respectively joined to the rear side frame 24.
This No. On the rear side of the vehicle body of the 8 cross member 33, a No. of closed cross-sectional structure that extends linearly in the vehicle width direction at the edge of the floor portion on the rear side of the vehicle body. Nine cross members 34 are provided, and both left and right ends in the vehicle width direction are joined to the rear ends of the rear side frame 24, respectively.

  In addition to the front side frame 18, the side sill 20, the floor side frame 22, and the rear side frame 24 described above as reinforcing members in the longitudinal direction of the vehicle body, the vehicle body longitudinal direction is provided at both edges of the floor tunnel portion 50 in the vehicle width direction. No. with a U-shaped cross section 1 to No. Three tunnel side members 36 to 38 are disposed. No. 1 tunnel side member 36 is No.1. 2 cross member 27 and No. 2 3 extends linearly across the cross member 28, and both end portions in the longitudinal direction of the vehicle body are respectively No. 2 cross member 27 and No. 2 3 It is joined to the cross member 28. No. 2 The tunnel side member 37 is 4 cross member 29 and no. 5 extends linearly between the cross member 30 and both end portions in the longitudinal direction of the vehicle body are respectively No. 5 and No. 5 cross members 30. 4 cross member 29 and no. 5 is joined to the cross member 30. No. 3 tunnel side member 38 is No.3. 6 cross member 31 and No. 6 7 extends linearly across the cross member 32, and both ends in the longitudinal direction of the vehicle body are respectively No. 7 and No. 7 cross member 32. 6 cross member 31 and No. 6 7 is joined to the cross member 32.

  The frame member having the U-shaped cross section described above, that is, the floor side frame 22, the rear side frame 24, No. 2 3 to No. 8 cross members 28 to 33 and No. 8 1 to No. Each of the three tunnel side members 36 to 38 is formed such that an open portion having a U-shaped cross section faces upward of the vehicle body, and the lower surface of each floor panel 2, 4, 6, 8, 10, 12, 14, 16 is These are joined to the flange portion of each frame member to form a substantially rectangular closed cross section.

  Next, the floor panel will be described with reference to FIG. As shown in FIG. 1, an underbody 1 of an automobile is provided with first to eighth floor panels 2, 4, 6, 8, 10, 12, 14, and 16 each integrally formed by press-molding steel plates. .

  The first floor panel 2 is No. 2 cross member 27, a pair of side sills 20, and A floor tunnel portion 50 is provided so as to cover the space surrounded by the three cross members 28 and bulges upward so as to extend in the vehicle longitudinal direction at a substantially central position in the vehicle width direction. The front edge of the first floor panel 2 is No. 2 is joined to the vehicle body rear side surface of the cross member 27, and the bottom surfaces of the remaining three sides are connected to the pair of side sills 20 and 3 on the left and right sides in the vehicle width direction. The lower surface of the 1 tunnel side member 36 and the floor side frame 22 are joined. In the first floor panel 2, panel regions S 1 and S 2 surrounded by the frame members 20, 22, 27, 28, 36 are respectively formed on the left and right sides of the floor tunnel portion 50 in the vehicle width direction.

  The second floor panel 4 is No. 3 cross member 28, a pair of side sills 20, and A floor tunnel portion 50 is provided so as to cover the space surrounded by the four cross members 29 and bulges upward so as to extend in the vehicle longitudinal direction at a substantially central position in the vehicle width direction. As for this 2nd floor panel 4, the lower surface of the edge of the 4 sides is No.2. 3 cross member 28, a pair of side sills 20, and The lower surface is bonded to the floor side frame 22 on both the left and right sides in the vehicle width direction. In addition, a fold portion 54 that is bent in a straight line is formed at both edges in the vehicle width direction of the floor tunnel portion 50 of the second floor panel 4, and the floor tunnel portion 50 rises from the fold portion 54. Further, the second floor panel 4 is formed with linear bead portions 56 on both sides thereof along the curved portion 22a of the floor side frame 22 described above. The bead portion 56 is formed by protruding the second floor panel 4 itself upward of the vehicle body. No. 3 cross member 28 no. 4 extends to the cross member 29. In the second floor panel 4, panel regions S 3 and S 4 surrounded by the frame members 20, 22, 28, 29, the bent portion 54 and the bead portion 56 are provided on the left and right sides of the floor tunnel portion 50 in the vehicle width direction. Each is formed.

  The third floor panel 6 is No. 4 cross member 29, floor side frame 22 and No. 4 A floor tunnel portion 50 is formed so as to cover the space surrounded by the five cross members 30 and bulges upward so as to extend in the vehicle longitudinal direction at a substantially central position in the vehicle width direction. As for this 3rd floor panel 6, the lower surface of the edge part of the 4 sides is No.2. 4 cross member 29, each floor side frame 22, and No. 4 cross member 29. 5 on each of the left and right sides in the vehicle width direction. The lower surface of the 2 tunnel side member 37 is joined. In addition, the third floor panel 6 has a No. 3 on both the left and right sides of the floor tunnel portion 50. 4 cross member 29 and no. A bead portion 58 extending linearly in the vehicle width direction is formed in parallel with the five cross member 30. The bead portion 58 is formed by protruding the third floor panel 6 itself upward of the vehicle body. In the third floor panel 6, panel regions S5 and S6 surrounded by the frame members 22, 29, 30, 37 and the bead portion 58 are respectively formed on the left and right sides of the floor tunnel portion 50 in the vehicle width direction. Yes.

  The fourth floor panel 8 is provided outside the third floor panel 6 in the vehicle width direction. 4 extends in the longitudinal direction of the vehicle body so as to cover the space surrounded by the cross member 29, the side sill 20, the floor side frame 22, and the rear side frame 24. It extends to the vicinity of the 8 cross member 33. These fourth floor panels 8 are joined to the frame members 20, 22, 24, and 29.

  The fifth floor panel 10 is No. 5 cross member 30, No. 5 6 The cross member 31, the pair of floor side frames 22 and the pair of rear side frames 24 are provided so as to cover the space, and the lower surfaces of the edges of the four sides are the frame members 22, 24, 30 respectively. , 31. In addition, a fold portion 54 that is bent in a straight line is formed at both edges in the vehicle width direction of the floor tunnel portion 50 of the fifth floor panel 10, and the floor tunnel portion 50 rises from the fold portion 54. In the fifth floor panel 10, panel regions S 7 surrounded by the frame members 22, 24, 30, 31 and the bent portion 54 are respectively formed on the left and right sides of the floor tunnel portion 50 in the vehicle width direction.

  The sixth floor panel 12 is No. 6 cross member 31, No. 6 7 is provided so as to cover the space surrounded by the cross member 32 and the pair of rear side frames 24, and the lower surfaces of the edges of the four sides are respectively joined to the frame members 24, 31, 32, On both the left and right sides in the vehicle width direction, no. The lower surface of the three tunnel side member 38 is joined. In the sixth floor panel 12, panel regions S8 surrounded by the frame members 24, 31, 32, and 38 are respectively formed on the left and right sides of the floor tunnel portion 50 in the vehicle width direction.

The seventh floor panel 14 is No. 7 cross member 32, no. It is provided so as to cover the space surrounded by the eight cross members 33 and the pair of rear side frames 24, and the lower surfaces of the edge portions of the four sides are joined to the frame members 24, 32 and 33, respectively.
The eighth floor panel 16 is No. 8 cross member 33, no. 9 is provided so as to cover the space surrounded by the cross member 34 and the pair of rear side frames 24, and the lower surfaces of the edge portions of the four sides are joined to the frame members 24, 33 and 34, respectively.

In such an underbody 1 of an automobile, vibrations of the engine 40, the front suspension 44, and the rear suspension 48 are respectively transmitted through a pair of floors via the front suspension cross member 42, the front side frame 18, and the rear suspension cross member 46. Largely transmitted to the side frame 22 and the rear side frame 24, and further transmitted to the cross members 26 to 34, the side sill 20, and the tunnel side members 36 to 38, and these vibrations are transmitted to the floor panels 2 to 16. As described above, the vibration transmitted to each floor panel is mainly a vibration of 400 Hz or less having a peak at a frequency in the vicinity of 250 Hz, which is road noise caused by tire cavity resonance. Acoustic radiation from the panel is generated, which becomes a factor of worsening vibration noise in the passenger compartment.
In the embodiment of the present invention, by providing the floor panel 2 with a vibration reduction structure, acoustic radiation from the floor panel 2 due to vibration transmitted from the frame member to the floor panel 2 is suppressed. The other floor panels 4, 6, 8, 10, 14, 16 are composed of conventional panels.

  Here, the vibration reducing structure will be described. The vibration reduction structure is provided with a predetermined high rigidity part (high rigidity part) and a predetermined low rigidity part (low rigidity part) in a predetermined area (panel area) of the floor panel surrounded by frame members. It is a thing. The vibration energy transmitted to the floor panel is concentrated on the low rigidity part due to the difference in rigidity between the high rigidity part and the low rigidity part. The large vibration distortion caused by this concentrated vibration energy and the material constituting the floor panel (steel plate) ) Vibration energy is converted into thermal energy by its own damping ability. As a result, since the vibration of the floor panel is reduced, the acoustic radiation from the floor panel is reduced (vibration reducing effect). Furthermore, when a damping material is provided in the low-rigidity part, the damping material is distorted with the distortion of the low-rigidity part, so that the vibration energy concentrated on the low-rigidity part is further reduced, and as a result, from the floor panel Acoustic radiation is more effectively reduced.

  In addition, by providing the high-rigidity part at the center of the panel area and providing the low-rigidity part so as to surround the high-rigidity part around the entire area, as will be described later, vibration is greatly concentrated on the low-rigidity part. To do. Further, the vibration transmitted from the frame member to the floor panel is reduced before being transmitted to the high rigidity portion (vibration blocking effect). Further, vibration energy of vibration transmitted to the floor panel via the frame member is reduced without being distributed to the entire floor panel. As a result, acoustic radiation from the floor panel can be more reliably reduced.

2 and 3, the effect of reduction of acoustic radiation by such a vibration reduction structure obtained by experiments will be described. FIG. 2 is a plan view (a) showing an experimental model of a floor panel having a vibration reducing structure and a cross-sectional view (b) taken along the line AA, and FIG. 3 is an experimental model of FIG. 2 and a conventional panel. It is a diagram which shows the experimental result obtained from this experimental model.
As shown in FIG. 2, the experimental model is obtained by attaching a panel 62 having a vibration reducing structure to an experimental frame member 60 having a rectangular cross section arranged in a square shape in plan view. The panel 62 is formed by press-molding a steel plate having a thickness of about 0.7 mm, and the size of the panel surrounded by the frame member 60 is about 300 mm in length and width. Yes. The panel 62 is formed with a high-rigidity portion 64 and a flat low-rigidity portion 66 around the high-rigidity portion 64, and a damping material 68 is attached to the low-rigidity portion 66.

In addition, as a conventional panel, an experimental model was prepared in which a steel plate having the same thickness as that of the panel 62 and a panel formed entirely on the surface was attached to the frame member 60 (not shown). The same amount of vibration damping material as that of the panel 62 was pasted on the entire surface of this conventional panel. In the experiment, a part of the frame member 60 to which the floor panel is attached is given a vibration force of a frequency of 500 Hz or less (white noise) with a vibrator, and the vibration magnitude of the panel with respect to the vibration magnitude of the frame. The ratio (vibration rate) was measured.
As shown in FIG. 3, the vibration rate of the panel 62 having the vibration reduction structure is lower than that of the conventional panel over a relatively wide range of a frequency of 400 Hz or less, and particularly, road noise caused by tire cavity resonance. As a result, the peak height appearing in the vicinity of 250 Hz is greatly reduced. Thus, it can be said that the acoustic radiation radiated from the panel is reduced by the vibration reducing structure.

  Next, the first embodiment of the present invention will be specifically described with reference to FIGS. 4 (a) to 4 (c). The first embodiment of the present invention is applied to a floor panel 2, and the vibration reduction structure according to the present embodiment is provided in each of the panel areas S1 and S2. The configurations of the vibration reduction structures in the panel regions S1 and S2 are the same, and are the same on the left and right sides of the floor tunnel portion 50 in the vehicle width direction. Therefore, hereinafter, the panel region S1 on the left side in the vehicle width direction with respect to the traveling direction will be described with reference to FIG. 4, and description of the other panel regions will be omitted. FIG. 4A is an enlarged plan view showing the panel region S1 of the floor panel 2 according to the first embodiment of the present invention, and FIG. 4B and FIG. 4C are respectively shown in FIG. It is sectional drawing which shows the cross-section of the floor panel 2 seen along line bb and cc.

First, as shown in FIG. 4A, the panel region S1 is a rectangular region surrounded by the frame members 20, 22, 27, and 28, and each frame member 20, 22, 27, and 28 is a straight line. The opposing frame members extend in parallel with each other.
In the panel region S1, one high-rigidity portion 70 is formed at the center thereof, and a low-rigidity portion 72 that extends in a square shape so as to surround the high-rigidity portion 70 around the high-rigidity portion 70 is formed. Is formed.

  Next, as shown in FIG. 4B and FIG. 4C, the high-rigidity portion 70 is integrally formed with the floor panel itself protruding in the out-of-plane direction, in this embodiment, upward, and the boundary portion. In 70a, it is raised from the low rigidity portion 72 at a discontinuous angle. On the other hand, the low-rigidity portion 72 is formed substantially flat so that its rigidity is smaller than that of the high-rigidity portion 70.

  As shown in FIGS. 4A to 4C, a damping material 74 is attached to the upper surface of the low-rigidity portion 72. This damping material 74 is an asphalt damping material and has a rectangular opening along the peripheral edge (a boundary with the low rigidity portion) 70 a of the high rigidity portion 70, and matches the shape of the low rigidity portion 72. It is formed in a sheet shape extending in a square shape, and is provided over the entire region of the low rigidity portion 72. The vibration damping material 74 may be another vibration damping material such as a coating type vibration damping material.

  Next, as shown to Fig.4 (a), the highly rigid part 70 is formed in the rectangular shape match | combined with the shape of the panel area | region S1, and while the four sides of the boundary part 70a extend linearly, each frame member It is formed so as to be parallel to 20, 22, 27 and 28. By forming in this way, the rigidity of the low-rigidity portion 72 is not increased, and a difference in rigidity between the high-rigidity portion 70 and the low-rigidity portion 72 is obtained reliably. That is, if the boundary portion 70a extends in a curved shape, the rigidity of the low-rigidity portion 72 is increased. However, if the boundary portion 70a extends linearly, the rigidity of the low-rigidity portion 72 does not need to be increased.

  Further, the high-rigidity portion 70 is formed so that the ratio of the area occupied in the panel region S1 is large in plan view (so that the area is at least larger than that of the low-rigidity portion 72). On the other hand, the width of the low-rigidity portion 72 (relative distance between each side of the boundary portion 70 a and each frame member 20, 22, 27, 28) is separated by a predetermined distance so that vibration concentrates on the low-rigidity portion 72. . Thus, the high-rigidity part 70 is formed over most of the panel region S1 so as not to hinder the concentration of vibration on the low-rigidity part 72.

  Next, as shown in FIG. 4A, the high-rigidity portion 70 is formed with an elliptical curved concave portion 70b in plan view. The curved concave portion 70b is formed in the central portion of the high-rigidity portion 70, and its peripheral edge portion 70c extends in a curved shape and has an elliptical shape. The curved concave portion 70b has an elliptical long axis extending in the longitudinal direction of the rectangular high-rigidity portion 70, and an intermediate portion in the longitudinal direction of the high-rigidity portion 70 (in the middle of the longitudinal direction, The portion extending in the short side direction) is formed so as to cross 70d.

  4B and 4C, the curved concave portion 70b is in a downward direction opposite to the upward direction, which is the entire protruding direction of the high-rigidity portion 70. As shown in FIG. It protrudes in a concave shape. And this curved surface recessed part 70b is comprised by the curved surface (curved surface in which a curvature does not change discontinuously) with the continuous curvature. In the present embodiment, the curvature continuously changes over the entire surface.

  On the other hand, a portion (curved convex portion) 70e other than the curved concave portion 70b in the high-rigidity portion 70 is formed by a curved surface that is convexly curved, and the curvature is continuous over the entire surface. The curvature is discontinuous at the boundary portion 70c between the curved convex portion 70e and the curved concave portion 70b.

  The height h of the portion of the high-rigidity portion 70 that protrudes most from the low-rigidity portion 72 (height of the peripheral edge portion 70c with respect to the low-rigidity portion 72) is 8 mm, and the protrusion height hb of the curved concave portion 70b (peripheral edge portion 70c). The height is 6 mm. Accordingly, the curved concave portion 70 b does not protrude downward from the low-rigidity portion 72. As described above, in the first embodiment, the entire high-rigidity portion 70 is formed so as to protrude upward with respect to the low-rigidity portion 72.

Next, the function and effect of the first embodiment will be described.
First, the floor panel 2 is provided with a high-rigidity portion 70 and a low-rigidity portion 72 in the panel region (S1, S2). Therefore, vibration energy is concentrated on the low-rigidity portion 72 due to the difference in rigidity between them. To do. As described above, in the low rigidity portion 72, the vibration energy of the floor panel 2 is reduced, and the acoustic radiation from the floor panel 2 can be reduced. Furthermore, since the low-rigidity portion 72 is provided with the vibration damping material 74, as described above, the acoustic radiation from the panel region can be further effectively reduced.

  Here, in the floor panel 2 of the present embodiment, a vibration system (a “mass point”) is used as the high-rigidity portion 70 and a “spring” is used as the low-rigidity portion 72 that connects the material point (high-rigidity portion 70) and the frame member. It can be considered that a spring-mass system is formed. The frame member can be regarded as an excitation source. In such a vibration system, there is only one mass point (high rigidity portion 70) supported by the spring (low rigidity portion 72), and the heavier the spring, the larger the spring bends (the low rigidity portion 72 is greatly distorted). ) And the vibration of the mass point is reduced (vibration transmitted to the high-rigidity portion 70 is effectively blocked by the spring low-rigidity portion 72 (vibration blocking effect)). In the present embodiment, based on such a viewpoint, only one high-rigidity portion 70 is formed in the central portion of the panel region S1, and the area thereof is relatively large, so that the high-rigidity portion 70 is surrounded in the entire periphery. A low-rigidity portion 72 is formed. Therefore, the low-rigidity portion 72 can be greatly distorted, and as a result, the above-described vibration reduction effect can be obtained more reliably. In addition, among the vibrations transmitted from the frame member to the floor panel, the vibration transmitted to the high-rigidity portion 70 can be effectively blocked by the low-rigidity portion 72, and as a result, the high-rigidity having a relatively large area. Acoustic radiation from the unit 70 is suppressed. Furthermore, vibration energy of vibration transmitted to the floor panel via the frame member is reduced without being distributed to the entire floor panel.

  Next, since the curved recess 70b is formed in the highly rigid portion 70, the rigidity of the highly rigid portion 70 can be further increased as compared with the case where the curved recess 70b is not formed. That is, the curved concave portion 70b has high rigidity due to its curved curved shape, and also has an elliptical shape in plan view and a peripheral portion extending in a curved shape. In addition, the rigidity in all directions including the vehicle width direction can be increased. Furthermore, since the curvature of the curved concave portion 70b is continuous over the entire surface, the rigidity of the high-rigidity portion 70 can be more reliably increased. The curved concave portion 70b may include a portion having a constant curvature (a portion having a circular cross section) as long as the curvature is continuous. Even in such a case, the same operation can be obtained.

  Here, to increase the rigidity of the high-rigidity part, it is effective to increase the height of the high-rigidity part, but it interferes with the exhaust pipes and accessories provided below or above the vehicle body of the floor panel. Or, the occupant's stepping feeling may be worsened. However, according to the present embodiment, the curved concave portion 70b can further increase the rigidity of the high-rigidity portion 70, so that the height of the high-rigidity portion 70 does not interfere with the exhaust pipe or the like, or the occupant's foot feeling It is possible to reliably increase the rigidity of the high-rigidity portion 70 while suppressing the height to a level that does not deteriorate.

  Further, when the highly rigid portion is formed in a rectangular shape, the greater the distance in the longitudinal direction, the more difficult it is to increase the rigidity unless the protruding height in the out-of-plane direction is increased. However, in the present embodiment, the curved concave portion 70b extends in an elliptical shape at the center of the high-rigidity portion 70, and the long axis of the ellipse extends in the longitudinal direction of the rectangular-shaped high-rigidity portion 70. The high-rigidity portion 70 is formed so as to cross the intermediate portion 70d in the longitudinal direction. Therefore, even if the height of the high-rigidity portion is suppressed, the rigidity in the longitudinal direction can be more reliably increased.

  Similarly, when the area of the panel region is large, it is effective to increase the area of the high-rigidity part in order to concentrate vibration on the low-rigidity part. It is difficult to increase the rigidity unless the height of the protrusion is made larger than that of the small case. However, even in such a case, according to the curved concave portion 70b of this embodiment, the rigidity of the high-rigidity portion can be reliably increased while suppressing the height of the high-rigidity portion.

  Next, in the present embodiment, the entire high-rigidity portion 70 is formed so as to protrude upward with respect to the low-rigidity portion 72. Therefore, interference with an exhaust pipe or the like disposed below the floor panel can be prevented. Here, the present applicant has found that if the protruding height of the high-rigidity portion 70 is 10 mm or less, the stepping comfort of the occupant is not deteriorated. In the present embodiment, since the protruding height h of the high-rigidity portion 70 is 8 mm, it is possible to prevent the step comfort of the passenger from deteriorating. In addition, you may make it the whole highly rigid part protrude below, In this case, interference with the auxiliary machines etc. which are arrange | positioned at the vehicle interior side can be prevented.

  In this way, according to the present embodiment, it is possible to reliably obtain a large difference in rigidity from the low-rigidity part while preventing interference with the exhaust pipe and the like and deterioration of the foot comfort of the passenger. As a result, the acoustic radiation from the floor panel can be more reliably reduced by the above-described vibration reduction effect.

  Next, a second embodiment of the present invention will be described. Similar to the first embodiment, the second embodiment of the present invention is applied to the floor panel 2 of the underbody 1 of the automobile shown in FIG. In the second embodiment, a groove portion 80f described later is formed in the high-rigidity portion 80, and the other basic configuration is the same as that of the first embodiment described above. Here, only differences from the first embodiment will be described with reference to FIGS. 5 (a) to 5 (c). FIG. 5A is an enlarged plan view showing a panel region S1 of the floor panel 2 according to the second embodiment of the present invention, and FIG. 5B and FIG. 5C are respectively shown in FIG. It is sectional drawing which shows the cross-section of the floor panel 2 seen along line bb and cc.

  As shown in FIGS. 5A to 5C, also in the second embodiment, a high-rigidity portion 80 is formed at the center portion of the panel region S1 and the high height is formed as in the first embodiment. A low-rigidity portion 82 is formed so as to surround the high-rigidity portion 80 in the entire area around the rigid portion 80. Moreover, the damping material 84 is provided in the low-rigidity part 82 similarly to 1st Embodiment. Further, similarly to the first embodiment, the highly rigid portion 80 is formed with an elliptical curved concave portion 80b in plan view.

  Next, in the second embodiment, in addition to the same configuration as that of the first embodiment, a groove 80f is formed. As shown in FIG. 5A, four groove portions 80f are formed, and each is formed on the curved convex portion 80e so as to communicate the curved concave portion 80b and the low-rigidity portion 82. Further, each of the groove portions 80f extends radially from the curved concave portion 80b. Further, as shown in FIG. 5C, these groove portions 80f are formed so as to protrude in the opposite direction (downward direction) to the protruding direction (upward direction) of the high-rigidity portion 80.

Next, the function and effect of the second embodiment will be described.
First, in this 2nd Embodiment, about the structure similar to 1st Embodiment, there exists an effect similar to the effect of 1st Embodiment mentioned above. In particular, the vibration energy in the panel region is reduced by the high-rigidity portion 80 and the low-rigidity portion 82, as in the operational effects of the first embodiment described above, so that the acoustic radiation from the panel region can be reduced. Moreover, the vibration energy in the panel region is further reduced by the damping material 84. Further, only one high-rigidity portion 80 is formed at the center portion of the panel region (S1, S2) and the area thereof is relatively large, and the low-rigidity portion 80 surrounds the high-rigidity portion 80 in the entire periphery. 82, the vibration is effectively concentrated on the low-rigidity portion 82 and greatly distorted, and the vibration transmitted to the high-rigidity portion 80 is effectively blocked by the low-rigidity portion 82. The vibration energy of the vibration transmitted to the floor panel 2 via the members 20, 22, 27, 28 is reduced without being distributed to the entire floor panel. As a result, acoustic radiation from the floor panel 2 can be more reliably reduced.
In the second embodiment, in addition to the configuration of the first embodiment, a groove 80f is formed. The operation of the groove 80f will be described. By forming the groove portion 80f, it is possible to increase the rigidity of the high-rigidity portion 80 mainly in the direction in which the groove portion 80f extends. In particular, the groove portion 80f is formed in the curved convex portion 80e and extends so as to communicate the curved concave portion 80b and the low-rigidity portion 82, so that the rigidity of the high-rigidity portion 80 can be increased more reliably. In addition, since a plurality of groove portions 80f are formed and extend radially from the curved concave portion 80b, the rigidity of the high-rigidity portion 80 can be more reliably increased in all directions including the vehicle body longitudinal direction and the vehicle width direction.
The groove portion 80f may be formed on the curved convex portion 80e so as to extend to the vicinity of the low rigid portion 82 or the curved concave portion 80b without communicating with the low rigid portion 82 and / or the curved concave portion 80b. Also in this case, it is preferable that the groove 80f extends radially.

  As described above, according to the second embodiment, the curved concave portion 80b and the groove portion 80f prevent the interference with the exhaust pipe or the like and the deterioration of the stepping feeling of the occupant, while reducing the rigidity difference from the low rigidity portion. It can be obtained with greater certainty. As a result, the acoustic radiation from the floor panel can be more reliably reduced by the above-described vibration reduction effect.

  Next, a third embodiment of the present invention will be described. The third embodiment of the present invention is applied to the floor panel 2 of the automobile underbody 1 shown in FIG. 1 as in the first embodiment. In the third embodiment, the high-rigidity portion 90 has a corrugated portion, and the corrugated portion is formed with a curved concave portion 90b and a groove portion 90f similar to those of the above-described embodiments. Since other basic configurations are the same as those of the first and second embodiments described above, only differences from the above-described embodiments will be mainly described with reference to FIGS. 6 (a) to 6 (d). To do. FIG. 6A is an enlarged plan view showing a panel region S1 of the floor panel 2 according to the third embodiment of the present invention. FIGS. 6B to 6D are respectively the same as FIG. It is sectional drawing which shows the cross-section of the floor panel 2 seen along line bb, cc, and dd. In FIG. 6A, contour lines corresponding to the degree of protrusion of the high-rigidity portion 90 in the vehicle body vertical direction (the out-of-plane direction of the floor panel 2) are also shown. In the high-rigidity portion 90, lines other than lines indicating the boundary portion 90a with the low-rigidity portion 92, the peripheral edge portion 90c of the curved concave portion 90b, and the groove portion 90f indicate such contour lines.

  As shown in FIGS. 6A to 6C, also in the third embodiment, similarly to the first embodiment, the rectangular high-rigidity portion 90 in a plan view is formed in the central portion of the panel region S1. A low-rigidity portion 92 that is formed and extends in a square shape so as to surround the high-rigidity portion 90 in a plan view and has a flat cross section is formed in the entire area around the high-rigidity portion 90. Further, similarly to the first embodiment, a vibration damping material 94 is provided in the low rigidity portion 92.

  Next, as shown in FIGS. 6 (a) and 6 (b), in the third embodiment, the high-rigidity portion 90 is a curved surface portion 90g that protrudes upward in a region on the front side in the longitudinal direction of the vehicle body. And a concave curved surface portion 90h projecting downward in the rear region, and a wave shape portion composed of the two curved surface portions 90g and 90h has a first shape as described later. An elliptical curved concave portion 90b and groove portion 90f are formed in a plan view similar to that of the first embodiment.

  First, the wave shape portion will be described. As shown in FIGS. 6B to 6D, the high-rigidity portion 90 was raised upward at a discontinuous angle from the low-rigidity portion 92 over the entire circumference of the boundary portion 90a. A raised portion 90e is formed, and a curved surface portion 90g is projected upward with respect to the upper end position (reference height he) of the raised portion 90e so as to be convex with respect to the passenger compartment. It protrudes in the direction and is formed in a concave shape with respect to the passenger compartment. Each curved surface portion 90g, 90h is formed of a curved surface having the same size and shape and having a continuous curvature. Further, the curvature continuously changes in the vicinity of the boundary portion 90d so that the curvature is continuous over the curved surface portions 90g and 90h, and the curvature is zero at the boundary portion 90d.

Thus, the high-rigidity portion 90 is formed with the curved surface portions 90g and 90h side by side in the longitudinal direction (long-side direction) of the rectangular high-rigidity portion 90, and the cross-sectional shape in the longitudinal direction is a wave shape. In other words, a corrugated portion is formed in which a convex curved surface and a concave curved surface appear continuously in the longitudinal direction.
The height he of the rising portion 90e is 6 mm, and the height of each curved surface portion 90g, 90h with respect to its upper end position (reference height he) is 4 mm, which is the same as each other. Accordingly, the height h of the portion of the curved surface portion 90g that protrudes most from the low-rigidity portion 92 is 10 mm at the maximum. And since the curved surface recessed part 90b is formed so that it may protrude below with respect to each of these curved surface parts 90g and 90h, the height of the highly rigid part 90 will be 10 mm or less. Further, a curved concave portion 90 b is formed so that the entire high rigidity portion 90 protrudes upward with respect to the low rigidity portion 92.

  Next, the curved concave portion 90b will be specifically described. As shown in FIG. 6A, the curved concave portion 90b is formed over the curved surface portions 90g and 90h of the above-described corrugated portion. Specifically, the long axis of the ellipse is formed in the central portion of the high-rigidity portion 90 and extends in the longitudinal direction of the rectangular high-rigidity portion 90, and the boundary portion 90d between the curved surface portions 90g and 90h. It is formed to cross.

  As shown in FIGS. 6B to 6D, the curved concave portion 90b protrudes in the opposite direction to the protruding direction with respect to the curved surface portion 90g, and the protruding direction with respect to the curved surface portion 90h. It protrudes further downward in the same direction. Similar to the first embodiment, the curved concave portion 90b is formed by a curved surface that protrudes in a concave shape in a downward direction that is opposite to the protruding direction of the entire high-rigidity portion 90 and has a continuous curvature.

  Next, the groove portion 90f will be described. As shown in FIG. 6A, similarly to the second embodiment, groove portions 90f that extend radially with respect to the curved concave portion 90b are formed so that the curved concave portion 90b and the low-rigidity portion 92 communicate with each other. As shown in FIGS. 6C and 6D, each of the groove portions 90f is formed so as to protrude downward with respect to the curved surface portions 90g and 90h or the rising portion 90e.

Next, the function and effect of the third embodiment will be described.
First, in this embodiment, about the structure similar to 1st Embodiment, there exists an effect similar to the effect of 1st Embodiment mentioned above. In particular, the vibrational energy of the panel region is reduced by the high-rigidity portion 90 and the low-rigidity portion 92 as in the case of the above-described operational effects of the first embodiment, so that acoustic radiation from the panel region can be reduced. In addition, the vibration damping material 94 further reduces vibration energy in the panel region. Further, only one high-rigidity portion 90 is formed at the central portion of the panel region (S1, S2), and the area thereof is relatively large. The low-rigidity portion 90 surrounds the high-rigidity portion 90 around the entire periphery. 92 is formed, the vibration is effectively concentrated on the low-rigidity portion 92 and greatly distorted, and the vibration transmitted to the high-rigidity portion 90 is effectively blocked by the low-rigidity portion 92, and the frame The vibration energy of the vibration transmitted to the floor panel 2 via the members 20, 22, 27, 28 is reduced without being distributed to the entire floor panel. As a result, acoustic radiation from the floor panel 2 can be more reliably reduced. Moreover, regarding the groove part 90f, there exists an effect similar to the effect of 2nd Embodiment.
Next, in the third embodiment, since the high-rigidity portion 90 has the corrugated portions (90g, 90h, 90d), the rigidity of the high-rigidity portion 90 can be more reliably increased. That is, the curved surface portions 90g and 90h constituting the wave shape portion have high rigidity due to the curved curved surface shape, and further, since the curvature is continuous throughout the wave shape portion, the rigidity of the high rigidity portion 90 as a whole. Can be increased. In particular, the rigidity can be increased in the direction in which the wave shape extends, that is, the direction in which the convex curved surface and the concave curved surface appear continuously. In the present embodiment, since the corrugations are continuous in the longitudinal direction of the high-rigidity portion 70, the rigidity in the longitudinal direction can be more reliably increased even if the height of the high-rigidity portion is suppressed. Further, since the curved surfaces 90g and 90h have the same height, the rigidity of the high-rigidity portion 90 can be increased more reliably.

  Furthermore, since the curved concave portion 90b formed of a curved surface having a continuous curvature is formed over the curved surface portions 90g and 90h of the corrugated portion, as in the first embodiment, the rigidity of the high-rigidity portion 90 is more sure. Can be increased. In particular, the curved concave portion 90b is formed at the center of the high-rigidity portion 90, and the long axis of the ellipse extends in the longitudinal direction of the high-rigidity portion 90 so as to cross the boundary portion 90d between the curved surface portions 90g and 90h. Since it extends, the rigidity in the longitudinal direction of the highly rigid portion 90 can be more reliably increased.

  As described above, in the third embodiment, the corrugated portions (90g, 90h, 90d), the curved concave portion 90b, and the groove portion 90f prevent the interference with the exhaust pipe or the like and the deterioration of the foot comfort of the passenger. The rigidity difference from the low-rigidity part can be obtained more reliably. As a result, the acoustic radiation from the floor panel can be more reliably reduced by the above-described vibration reduction effect. As a modification of the present embodiment, the rising portion 90e may not be formed, and the curved surface portions 90g and 90h may be formed so as to protrude upward and downward with respect to the low-rigidity portion 92, respectively. In this case, in order not to deteriorate the occupant's feeling of stepping on the occupant, the high-rigidity part is combined with the height from the low-rigidity part in the uppermost part and the height from the low-rigidity part in the lowermost part. It is preferable that the thickness is 10 mm or less.

  Next, a fourth embodiment of the present invention will be described. 4th Embodiment of this invention is applied to the floor panel 2 of the underbody 1 of the motor vehicle shown in FIG. 1 similarly to 1st Embodiment. In the fourth embodiment, the high-rigidity portion 100 has a corrugated portion having a shape different from that of the third embodiment, and the corrugated portion is formed with a curved concave portion 100b similar to the above-described embodiments. . Since other basic configurations are the same as those of the above-described embodiments, only differences from the above-described embodiments will be mainly described with reference to FIGS. 7A to 7C. FIG. 7A is an enlarged plan view showing a panel region S1 of the floor panel 2 according to the fourth embodiment of the present invention, and FIG. 7B and FIG. 7C are respectively shown in FIG. It is sectional drawing which shows the cross-section of the floor panel 2 seen along line bb and cc. 7A also shows contour lines in the same manner as in FIG. 6A. In the high-rigidity portion 100, a line indicating the boundary portion 100a with the low-rigidity portion 102 and the peripheral edge portion 100c of the curved concave portion 100b. Lines other than indicate such contour lines.

  As shown in FIGS. 7A to 7C, also in the fourth embodiment, similarly to the first embodiment, a rectangular high-rigidity portion 100 in a plan view is formed at the center of the panel region S1. A low-rigidity portion 102 that is formed and extends in a square shape to surround the high-rigidity portion 100 in plan view and has a flat cross section is formed in the entire area around the high-rigidity portion 100. Moreover, the damping material 104 is provided in the low-rigidity part 102 similarly to 1st Embodiment.

  Next, as shown in FIGS. 7A and 7B, in the fourth embodiment, the high-rigidity portion 100 includes two curved surface portions 100g and 100h and a boundary between the curved surface portions 100g and 100h. A corrugated portion is formed by the portion 100d, and an elliptical curved concave portion 100b is formed in the corrugated portion in plan view similar to the first embodiment, as will be described later.

  First, the wave shape portion will be described. As shown in FIGS. 7 (b) to 7 (d), the high-rigidity portion 100 has a convex shape with respect to the passenger compartment, protruding upward in the front and rear regions of the vehicle body longitudinal direction. Two curved surface portions 100g and 100h are formed. These curved surface portions 100g and 100h are formed of curved surfaces having the same size and shape and continuous curvature. The protruding heights of these curved surface portions 100g and 100h from the low rigidity portion 102 are both 8 mm. Further, the entire high-rigidity portion 100 is formed so as to protrude upward in the out-of-plane direction with respect to the low-rigidity portion 102.

  7A, the boundary portion 100d between the curved surface portions 100g and 100h extends in a straight line in the short side direction of the high-rigidity portion 100 in the middle of the long-side direction of the high-rigidity portion 100. Yes. As shown in FIG. 7B, the boundary portion 100d is formed of a curved surface having a curvature that protrudes in a concave shape downward, and the curved surface portions 100g and 100h and the concave curved surface of the boundary portion 100d are mutually connected. The curvature is formed to change continuously. Accordingly, the curvature is 0 at each boundary (two locations) between the boundary portion 100d and the curved surface portions 100g and 100h. Thus, the highly rigid part 100 is formed so that the cross-sectional shape of the longitudinal direction becomes a wave shape.

  Next, the curved concave portion 100b will be described. As shown in FIG. 7A, the curved concave portion 100b is formed over the curved surface portions 100g and 100h of the above-described corrugated portion. Specifically, the long axis of the ellipse is formed in the central portion of the high-rigidity portion 100 and extends in the longitudinal direction of the rectangular high-rigidity portion 90, and the boundary portion 100d between the curved surface portions 100g and 100h. It is formed to cross.

  As shown in FIGS. 7B to 7D, the curved concave portion 100b protrudes in the opposite direction to the protruding direction with respect to the curved surface portions 100g and 100h. Similar to the first embodiment, the curved concave portion 100b is configured by a curved surface that protrudes in a concave shape in a downward direction that is opposite to the overall protruding direction of the high-rigidity portion 100 and has a continuous curvature.

Next, the function and effect of the fourth embodiment will be described.
First, in this embodiment, about the structure similar to 1st Embodiment, there exists an effect similar to the effect of 1st Embodiment mentioned above. In particular, since the vibration energy of the panel region is reduced by the high-rigidity portion 100 and the low-rigidity portion 102, as in the operation and effect of the first embodiment described above, acoustic radiation from the panel region can be reduced. Moreover, the vibration energy in the panel region is further reduced by the damping material 104. Further, only one high-rigidity portion 100 is formed at the center portion of the panel region (S1, S2) and the area thereof is relatively large. 102 is formed, the vibration is effectively concentrated on the low-rigidity portion 102 and greatly distorted, and the vibration transmitted to the high-rigidity portion 100 is effectively blocked by the low-rigidity portion 102, and the frame The vibration energy of the vibration transmitted to the floor panel 2 via the members 20, 22, 27, 28 is reduced without being distributed to the entire floor panel. As a result, acoustic radiation from the floor panel 2 can be more reliably reduced.
Next, in the fourth embodiment, since the high-rigidity portion 100 has the corrugated portions (100g, 100h, 100d), the rigidity of the high-rigidity portion 100 can be more reliably increased as in the third embodiment. In addition, since the wave shape extends in the longitudinal direction of the high-rigidity portion 100, the rigidity in the longitudinal direction of the high-rigidity portion 100 can be more reliably increased.

  Furthermore, since the curved concave portion 100b configured by a curved surface having a continuous curvature is formed over the curved surface portions 100g and 100h of the corrugated portion, as in the third embodiment, The rigidity can be increased more reliably. Further, similarly to the third embodiment, the long axis of the ellipse of the high-rigidity portion 100 extends in the longitudinal direction of the high-rigidity portion 100 so as to cross the boundary portion 100d between the curved surface portions 100g and 100h. The rigidity in the longitudinal direction of the rigid portion 100 can be more reliably increased.

  As described above, in the fourth embodiment, the wave shape portions (100g, 100h, 100d) and the curved concave portion 100b prevent interference with the exhaust pipe or the like and deterioration of the foot comfort of the occupant, while reducing the rigidity. The difference in rigidity with the part can be obtained more reliably. As a result, the acoustic radiation from the floor panel can be more reliably reduced by the above-described vibration reduction effect. In the fourth embodiment, the same groove portions (80f, 90f) as in the second and third embodiments may be formed. Also in this case, the same effects as those described above with respect to the groove can be obtained.

  Next, a fifth embodiment of the present invention will be described. The fifth embodiment of the present invention is applied to the floor panel 2 of the underbody 1 of the automobile shown in FIG. 1 as in the first embodiment. In the fifth embodiment, the high-rigidity portion 110 has a corrugated portion similar to that of the fourth embodiment, and the corrugated portion is formed with a curved concave portion 110b whose shape and protruding direction are different from those of the above-described embodiments. Has been. Since other configurations are the same as those of the above-described embodiments, only differences from the above-described embodiments will be mainly described with reference to FIGS. 8A to 8C. FIG. 8A is an enlarged plan view showing the panel region S1 of the floor panel 2 according to the fifth embodiment of the present invention. FIGS. 8B and 8C are respectively the same as FIG. It is sectional drawing which shows the cross-section of the floor panel 2 seen along line bb and cc. In FIG. 8 (a), contour lines are also shown in the same manner as in FIG. 6 (a). In the high-rigidity portion 110, a line indicating the boundary portion 110a with the low-rigidity portion 112 and the peripheral edge portion 110c of the curved concave portion 110b. Lines other than indicate such contour lines.

  As shown in FIGS. 8A to 8C, in the fifth embodiment as well, in the same manner as in the first embodiment, a rectangular high-rigidity portion 110 in the center of the panel region S1 is seen in plan view. A low-rigidity portion 112 that is formed and extends in a square shape so as to surround the high-rigidity portion 110 in a plan view and has a flat cross section is formed in the entire area around the high-rigidity portion 110. Moreover, the damping material 114 is provided in the low-rigidity part 112 similarly to 1st Embodiment.

  Next, as shown in FIGS. 8A and 8B, in the fifth embodiment, as in the fourth embodiment, the high-rigidity portion 110 includes two curved surface portions 110g and 110h and a boundary. A waveform portion is formed by the portion 110d. In the present embodiment, a circular curved concave portion 110b is formed on the corrugated portion so as to protrude upward in a plan view.

  The curved concave portion 110b will be described. As shown in FIG. 8A, the curved concave portion 110b is formed in a circular shape in a plan view and is formed over the curved surface portions 110g and 110h of the above-described corrugated portion. Specifically, the curved concave portion 110b is formed at the central portion of the high-rigidity portion 110 and is formed so as to cross the boundary portion 110d between the curved surface portions 110g and 110h.

  As shown in FIGS. 8A to 8C, the curved concave portion 110b covers a valley region between the curved surface portions 110g and 110h (a region near the boundary portion 110d including the boundary portion 110d). Or it forms so that each curved surface part 110g, 110h may be connected, and it curves and protrudes in the convex direction upwards which is the same as the whole protrusion direction of the highly rigid part 110. The curved concave portion 110b is formed of a curved surface having a continuous curvature, as in the first embodiment. The curved concave portion 110b protrudes in the same direction as the protruding direction with respect to the curved surface portions 110g and 110h, and the height with respect to the low-rigidity portion 102 is 8 mm, which is the same as the curved surface portions 110g and 110h. Is formed.

Next, functions and effects of the fifth embodiment will be described.
First, in this embodiment, about the structure similar to 1st Embodiment, there exists an effect similar to the effect of 1st Embodiment mentioned above. In particular, similar to the effects of the first embodiment described above, the vibration energy in the panel region can be reduced by the high-rigidity portion 110 and the low-rigidity portion 112, and acoustic radiation from the panel region can be reduced. Moreover, the vibration energy in the panel region is further reduced by the damping material 114. Further, only one high-rigidity part 110 is formed at the center of the panel region (S1, S2) and the area thereof is relatively large, and the low-rigidity part 110 surrounds the high-rigidity part 120 around the entire periphery. 112 is formed, the vibration is effectively concentrated on the low-rigidity portion 112 and greatly distorted, and the vibration transmitted to the high-rigidity portion 110 is effectively blocked by the low-rigidity portion 112, and the frame The vibration energy of the vibration transmitted to the floor panel 2 via the members 20, 22, 27, 28 is reduced without being distributed to the entire floor panel. As a result, acoustic radiation from the floor panel 2 can be more reliably reduced.
Next, in the fifth embodiment, since the high-rigidity portion 110 has the corrugated portions (110g, 110h, 110d), the rigidity of the high-rigidity portion 110 is more reliably ensured as in the third and fourth embodiments. Further, since the wave shape extends in the longitudinal direction of the high-rigidity portion 110, the rigidity in the longitudinal direction of the high-rigidity portion 110 can be more reliably increased.

  Furthermore, since the curved surface concave portion 110b composed of a curved surface having a continuous curvature is formed over the curved surface portions 110g and 110h of the corrugated portion, high rigidity is achieved as in the third and fourth embodiments. The rigidity of the portion 110 can be more reliably increased. Here, in the present embodiment, the curved concave portion 110b is formed in a circular shape in plan view. Thus, even if the shape of the curved concave portion is a circular shape, the curved curved shape and the peripheral portion extend in a curved shape, and thus the same operational effects as the elliptical curved concave portion described above are exhibited. On the other hand, when the high-rigidity portion has a rectangular shape as in the present embodiment, it is preferable to form an elliptical shape. Note that the curved concave portion of the first to fourth embodiments described above may be formed in a circular shape in plan view, or in the fifth embodiment, the curved concave portion 110b may be formed in an elliptical shape in plan view. .

  Next, even if it is formed so as to protrude in a convex shape in the upward direction, which is the same as the entire protruding direction of the high-rigidity portion 110, like the curved concave portion 110b of this embodiment, the curved concave portion 110b Similar to the first to fourth embodiments described above, the rigidity of the high-rigidity portion 110 can be further increased. In particular, the curved concave portion 110b is formed so as to cover the valley region between the curved surface portions 110g and 110h (the vicinity region of the boundary portion 110d including the boundary portion 110d) or to connect the curved surface portions 110g and 110h. Therefore, the curved surface portion 110b can further increase the rigidity of the corrugated portion, and as a result, the rigidity of the high-rigidity portion 110 can be more reliably increased.

  In addition, since the entire high-rigidity portion 100 is formed so as to protrude upward with respect to the low-rigidity portion 102, interference with an exhaust pipe or the like disposed below the floor panel can be prevented. Further, the curved concave portion 110b is formed so that the protruding height from the low-rigidity portion 102 is 8 mm, which is the same as that of the curved surface portions 110g and 110h. It can also prevent the stepping comfort of foot from getting worse.

  As described above, according to the fifth embodiment, the corrugated portions (110g, 110h, 110d) and the curved concave portion 110b prevent the interference with the exhaust pipe or the like and the deterioration of the foot comfort of the occupant. The rigidity difference from the rigid part can be obtained more reliably. As a result, the acoustic radiation from the floor panel can be more reliably reduced by the above-described vibration reduction effect. In the fifth embodiment also, the groove portions (80f, 90f) similar to those in the second and third embodiments may be formed. Also in this case, the same effects as those described above with respect to the groove can be obtained.

Next, another aspect of each embodiment of the present invention will be described.
First, as shown in FIG. 9, when forming a wave-shaped portion in the high-rigidity portion, a total of four curved surface portions 120 g are formed, two each in the long-side direction and the short-side direction of the rectangular high-rigidity portion 120. You may do it. Here, reference numeral 122 denotes a low rigidity portion, and reference numeral 124 denotes a vibration damping material, both of which are formed in the same manner as in the third to fifth embodiments. In FIG. 9, contour lines are also shown in the same manner as in FIG. 6A. In the high-rigidity portion 120, lines other than the lines indicating the boundary portion 120a with the low-rigidity portion 122 and the peripheral edge portion 120c of the curved concave portion 120b. Indicates such contour lines.
In this aspect, as in the fourth embodiment, all of the four curved surface portions 120g protrude upward, and the curved concave portion 120b protrudes downward (see FIG. 7B). Further, as shown in FIG. 9, the curved concave portion 120b is formed in the central portion of the high-rigidity portion 110 so as to cross all the boundary portions 120d between the curved surface portions 120g.

According to such a high-rigidity portion 120, the rigidity can be more reliably increased both in the vehicle longitudinal direction and in the vehicle width direction. In particular, when the area of the floor panel surrounded by the frame member (panel area S1 or the like) is large, or when forming a square high-rigidity portion in a square area such as the panel area S7, for example. It is preferable to form as shown in FIG.
In addition, you may form the curved surface recessed part 120b so that it may protrude in the same direction as the direction where a highly rigid part protrudes like 5th Embodiment (refer FIG.8 (b)). Moreover, you may form the four curved surface parts 120g so that a convex-shaped and concave curved-surface part may be located in a line like 3rd Embodiment (refer FIG.6 (b)). For example, a curved surface portion projecting upward (see 90g in FIG. 6B) is arranged so as to be located diagonally, and a curved surface portion projecting downward (see 90h in FIG. 6B) is placed on the other side. You may arrange | position so that it may be located on a diagonal.

  Next, the corrugated portion formed in the highly rigid portion may be formed such that three or more curved portions are arranged in the longitudinal direction of the highly rigid portion. Even in such a case, it is preferable that a curved concave portion is formed over each curved surface portion.

Next, the floor panel 2 to which each of the above-described embodiments is applied is provided across the vehicle width direction and has a plurality of panel regions (S1, S2). Similar effects can be obtained also in a floor panel in which individual panels are used for each panel, and the peripheral edge of each panel is joined to each frame.
Next, for example, as in the above-described floor panels 4, 6, and 11, a part thereof is also surrounded by a bead portion (56, 58) and / or a folding portion (54) that is a vibration regulating portion while being surrounded by a frame member. Even when the same vibration reduction structure as that of the above-described embodiment is provided in the panel regions S4 to S7, the same effect can be obtained.
Next, even if a vibration reducing structure similar to that of the above-described embodiment is formed in a panel region whose shape is not rectangular, for example, the panel regions S4 to S6 of the above-described floor panels 4 and 6, the same effect can be obtained. can get. In this case, the high-rigidity part may be formed in a trapezoidal shape according to the shape of the panel region, for example, and the shape of each curved surface part may be a trapezoidal shape in plan view.

It is a perspective view which shows the underbody of the motor vehicle provided with the floor panel by embodiment of this invention. It is the top view (a) which shows the experimental model of the floor panel which has a vibration reduction structure, and sectional drawing (b) seen along the AA line. It is a diagram which shows the experimental result obtained from the experimental model of FIG. 2, and the experimental model of the conventional panel. It is an enlarged plan view which shows panel area | region S1 of the floor panel 2 by 1st Embodiment of this invention. FIG. 5 is a cross-sectional view showing a cross-sectional structure in the longitudinal direction of the vehicle body as viewed along line bb in FIG. It is sectional drawing which shows the cross-section of the vehicle width direction seen along the cc line of Fig.4 (a). It is an enlarged plan view which shows panel area | region S1 of the floor panel 2 by 2nd Embodiment of this invention. FIG. 6 is a cross-sectional view showing a cross-sectional structure in the longitudinal direction of the vehicle body as viewed along line bb in FIG. It is sectional drawing which shows the cross-section of the vehicle width direction seen along the cc line of Fig.5 (a). It is an enlarged plan view which shows panel area | region S1 of the floor panel 2 by 3rd Embodiment of this invention. It is sectional drawing which shows the cross-sectional structure of the vehicle body front-back direction seen along the bb line of Fig.6 (a). It is sectional drawing which shows the cross-sectional structure of the vehicle width direction seen along the cc line of Fig.6 (a). It is sectional drawing which shows the cross-section of the vehicle width direction seen along the dd line of Fig.6 (a). It is an enlarged plan view which shows panel area | region S1 of the floor panel 2 by 4th Embodiment of this invention. It is sectional drawing which shows the cross-sectional structure of the vehicle body front-back direction seen along the bb line | wire of Fig.7 (a). It is sectional drawing which shows the cross-sectional structure of the vehicle width direction seen along the cc line of Fig.7 (a). It is an enlarged plan view which shows panel area | region S1 of the floor panel 2 by 5th Embodiment of this invention. It is sectional drawing which shows the cross-sectional structure of the vehicle body front-back direction seen along the bb line | wire of Fig.8 (a). It is sectional drawing which shows the cross-sectional structure of the vehicle body front-back direction seen along the cc line of Fig.8 (a). It is an enlarged plan view which shows panel area | region S1 of the floor panel 2 by the other aspect of this invention.

Explanation of symbols

1 Car underbody
2,4,6,8,11,12,14,16 1st to 8th floor panels
S1 to S8 Panel area
18 Front side frame
20 Side sills
22 Floor side frame
24 Rear side frame
26-34 No. 1-No. 9 cross members
36-38 No. 1-No. 3 tunnel side members
40 engine
42 Front suspension cross member
46 Rear suspension cross member
70,80,90,100,110,120 High rigidity part
72,82,92,102,112,122 Low rigidity part
74,84,94,104,114,124 Damping material
70a, 80a, 90a, 100a, 110a, 120a Peripheral part of high rigidity part (boundary part with low rigidity part)
70b, 80b, 90b, 100b, 110b, 120b Curved concave part of high rigidity part
70c, 80c, 90c, 100c, 110c, 120c
70e, 80e Curved convex part of high rigidity part
90e Rising part of high rigidity part
90d, 100d, 110d, 120d Boundaries between each curved surface
90g, 90h, 100g, 100h, 110g, 110h, 120g Each curved surface part of the corrugated part of the highly rigid part

Claims (9)

A vehicle body floor panel connected to a frame member disposed in a vehicle longitudinal direction and a vehicle width direction and constituting a vehicle floor,
A high-rigidity part that protrudes upward or downward at the center of the region surrounded by the frame member, and a low-rigidity part that is formed flat around the high-rigidity part,
A floor panel of a vehicle body, wherein the high-rigidity portion has a curved concave portion that protrudes in a curved shape in a direction opposite to the protruding direction at a central portion thereof and is circular or elliptical in a plan view.   The vehicle body floor panel according to claim 1, wherein the curved concave portion has a continuous curvature over the entire surface.   The vehicle floor panel according to claim 1 or 2, wherein the high-rigidity portion protrudes upward, and the curved concave portion of the high-rigidity portion protrudes downward at a protrusion height smaller than the protrusion height of the high-rigidity portion.   The floor panel of a vehicle body according to any one of claims 1 to 3, wherein a protruding height of the high-rigidity portion from the low-rigidity portion is 10 mm or less.   The vehicle body floor panel according to any one of claims 1 to 4, wherein the high-rigidity portion is further formed with a groove portion extending so as to connect the curved concave portion and the low-rigidity portion.   The floor panel of a vehicle body according to any one of claims 1 to 4, wherein the high-rigidity portion is further formed with a groove portion extending radially with respect to the curved concave portion. The high-rigidity part is formed with a wave-shaped part composed of at least two curved surface parts,
The floor panel of a vehicle body according to any one of claims 1 to 6, wherein the curved concave portion of the high-rigidity portion is formed between the curved surface portions of the corrugated portion. The high rigidity portion is formed in a rectangular shape,
The floor panel of a vehicle body according to claim 7, wherein two curved portions of the wave-shaped portion are formed side by side in the longitudinal direction of the rectangular high-rigidity portion. A vehicle body floor panel connected to a frame member disposed in a vehicle longitudinal direction and a vehicle width direction and constituting a vehicle floor,
A high-rigidity portion formed at the center of the region surrounded by the frame member, and a low-rigidity portion formed flat around the high-rigidity portion,
The high-rigidity part is formed with a wave-shaped part composed of at least two curved surface parts, and further protrudes in a curved shape upward or downward between each curved surface part of the wave-shaped part, and is circular in plan view. Or the floor panel of the vehicle body characterized by the oval-shaped curved recessed part being formed.

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