JP6369525B2 - Vehicle panel structure - Google Patents

Description

  The present invention relates to a panel structure incorporated in a vehicle.

  The panel structure is generally used to form a wide surface of a vehicle. For example, the panel structure is used as a vehicle roof or floor panel. In order to protect passengers in the vehicle, high rigidity is required for the panel structure. On the other hand, in order to dampen vibration (for example, vibration transmitted from a road surface), high damping performance may be required for the panel structure. If the vibration transmitted to the occupant is sufficiently damped, the occupant can spend comfortably in the vehicle.

  Rigidity is generally a performance that contradicts the damping performance. That is, if the panel structure has high rigidity, the panel structure does not attenuate vibrations so much. If the panel structure has a high damping performance, the rigidity of the panel structure is not so high.

  Patent document 1 discloses the panel structure which consists of a damping elastic layer and a pair of panel member formed from the carbon fiber reinforced plastic. The damping elastic layer is sandwiched between two panel members. Since the carbon fiber reinforced plastic used for these panel members has high rigidity, the panel structure can have sufficient rigidity to protect the occupant. The damping elastic layer attenuates the transmitted vibration, so that the vibration is sufficiently damped before reaching the occupant.

JP 2011-183562 A

  The damping elastic layer of Patent Document 1 is filled in the entire space between the two panel members. Since the viscoelastic material used as the vibration damping elastic layer generally has a large specific gravity, the panel structure of Patent Document 1 is heavy. This adversely affects other vehicle performance (eg, fuel economy). In addition, viscoelastic materials are generally expensive. Therefore, the vehicle incorporating the panel structure of Patent Document 1 is also expensive.

  An object of the present invention is to provide a lightweight and inexpensive panel structure having high rigidity and excellent damping performance.

A vehicle panel structure according to an aspect of the present invention includes a restrained first peripheral edge, and a first corner, a second corner, a third corner, and a first corner formed by the first peripheral. A first panel member made of a resin having a first region forming a curved surface having a rectangular outline having a quadrangular corner, a second peripheral edge constrained together with the first peripheral edge, and the second A resin-made second panel member having a second region surrounded by a peripheral edge and forming a curved surface facing the first region, and is formed between the first region and the second region. A plurality of viscoelastic members that are spaced apart from each other and cover an area of 12.5% to 50% of the first region . The first region is virtually set to be orthogonal to the z-axis that is virtually set to pass through the center of the first region and the center of the second region in the space. The first divided region, the second divided region, the first divided region, and the y axis that is virtually set to be orthogonal to the z axis and the x axis at the intersection of the z axis and the x axis. It is conceptually divided into three divided areas and a fourth divided area . Said plurality of viscoelastic members, the first viscoelastic member disposed between the first divided region and the second region, which is disposed between the second divided region and the second region 2 viscoelastic member, a fourth viscoelastic disposed between the third divided region and the third viscoelastic member and the fourth divided region and the second region arranged between the second region It consists only of members . The first corner portion is a corner portion of the first divided region . The second corner portion is a corner portion of the second divided region . The third corner portion is a corner portion of the third divided region . The fourth corner is a corner of the fourth divided region . The first viscoelastic member is disposed closer to the first corner than the intersection . The second viscoelastic member is disposed closer to the second corner than the intersection . The third viscoelastic member is disposed closer to the third corner than the intersection . The fourth viscoelastic member is disposed closer to the fourth corner than the intersection.

  According to the above-described configuration, since the first panel member and the second panel member are made of resin, the vehicle panel structure is lightweight and can have high rigidity. Since the plurality of viscoelastic members are arranged in a space formed between the first region of the first panel member and the second region of the second panel member, the vibration transmitted to the vehicle panel structure is sufficient. Is attenuated. Since the second viscoelastic member is separated from the first viscoelastic member, the plurality of viscoelastic members do not completely occupy the space between the first region and the second region. Therefore, the vehicle panel structure does not become excessively heavy.

The first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member are a first divided region, a second divided region, a third divided region, which are conceptually divided from the first region, Since the vehicle panel structure is disposed corresponding to each of the fourth divided regions, the vehicle panel structure can attenuate the vibration over a plane defined by the x-axis and the y-axis. Since the first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member are separated from each other, the plurality of viscoelastic members are disposed between the first region and the second region. It does not take up space completely. Therefore, the vehicle panel structure does not become excessively heavy.

Since each of the first region and the second region is a curved surface, the vehicle panel structure can be suitably used for a vehicle part that requires a curved shape. Since the plurality of viscoelastic members cover an area of 12.5% or more of the first region, the vibration transmitted to the vehicle panel structure is sufficiently damped. Since the plurality of viscoelastic members cover an area of 50% or less of the first region, the vehicle panel structure does not become excessively heavy.

Since the first region is a curved surface having a rectangular outline bent at the first corner, the second corner, the third corner, and the fourth corner formed by the first peripheral edge, The vehicle panel structure can be suitably used for a part of a vehicle that requires formation of a curved surface. The first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member have a first corner corner and a second corner from the intersection formed by the x axis, the y axis, and the z axis. Since they are arranged near the corner, the third corner, and the fourth corner, respectively, these viscoelastic members can effectively attenuate the vibration transmitted to the vehicle panel structure.

A vehicle panel structure according to another aspect of the present invention is a resin-made first panel member having a constrained first peripheral edge and a first region forming a plane surrounded by the first peripheral edge. And a second peripheral portion that is constrained together with the first peripheral portion, and a second region that is surrounded by the second peripheral portion and forms a plane that faces the first region. Two panel members and a plurality of viscoelasticity arranged apart from each other in a space formed between the first region and the second region and covering an area of 10% or more and 50% or less of the first region A member. The first region is virtually set to be orthogonal to the z-axis that is virtually set to pass through the center of the first region and the center of the second region in the space. The first divided region, the second divided region, the first divided region, and the y axis that is virtually set to be orthogonal to the z axis and the x axis at the intersection of the z axis and the x axis. It is conceptually divided into three divided areas and a fourth divided area. The plurality of viscoelastic members include a first viscoelastic member disposed between the first divided region and the second region, and a second disposed between the second divided region and the second region. Only the viscoelastic member, the third viscoelastic member disposed between the third divided region and the second region, and the fourth viscoelastic member disposed between the fourth divided region and the second region. Consists of. The first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member have a square shape. The second viscoelastic member is arranged in a line-symmetrical position with the first viscoelastic member with respect to the x axis. The third viscoelastic member is arranged in a line-symmetrical position with the second viscoelastic member with respect to the y-axis. The fourth viscoelastic member is disposed at a point-symmetrical position with the second viscoelastic member around the z axis. Between the first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member, a cruciform shape extending along the x-axis and the y-axis with a predetermined width. A void zone is formed. The square shapes of the first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member have sides of a predetermined length. The predetermined width is not less than 0.13 times and not more than 0.20 times the predetermined length.

  According to the above-described configuration, since each of the first region and the second region is a flat surface, the vehicle panel structure can be suitably used for a vehicle portion where a flat surface is required. Since the plurality of viscoelastic members cover an area of 10% or more of the first region, the vibration transmitted to the vehicle panel structure is sufficiently damped by the plurality of viscoelastic members. Since the plurality of viscoelastic members cover an area of 50% or less of the first region, the vehicle panel structure does not become excessively heavy.

Between the first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member, a cross-shaped gap band extending along the x-axis and the y-axis with a predetermined width is formed. Therefore, the first panel member and the second panel member are likely to bend along the cross-shaped gap band. The width of the gap band is not more than 0.20 times the length of the square side of the first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member. The elastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member can effectively share the strain energy derived from the deformation of the first panel member and the second panel member. As a result, the vehicle panel structure can have excellent damping performance against vibration. The width of the gap band is not less than 0.13 times the length of the square sides of the first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member. The elastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member are not excessively dense. Therefore, the vehicle panel structure does not become excessively heavy.

  In the above configuration, each of the first region and the second region may be rectangular. Even if the first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member are separated from the four corners of the first region and the second region, respectively. Good.

  According to the above configuration, the first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member are separated from the four corners of each of the first region and the second region. Therefore, these viscoelastic members are arranged in a place where the first panel member and the second panel member are easily deformed. Therefore, the first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member effectively share the strain energy derived from the deformation of the first panel member and the second panel member. Can do. As a result, the vehicle panel structure can have excellent damping performance against vibration.

  With regard to the above configuration, the vehicle panel structure includes a first foam member disposed between the first region and the plurality of viscoelastic members, and a region between the second region and the plurality of viscoelastic members. You may further provide the 2nd foaming member arrange | positioned.

  According to the above configuration, the first foam member is disposed between the first region and the plurality of viscoelastic members, and the second foam member is disposed between the second region and the plurality of viscoelastic members. Therefore, the designer who designs the vehicle panel structure can increase the thickness of the vehicle panel structure without excessively thickening the first panel member, the second panel member, and the plurality of viscoelastic members. Can be given. Therefore, the vehicle panel structure can have high rigidity while being lightweight, and is inexpensive.

  The vehicle panel structure described above can have high rigidity and excellent damping performance. In addition, the above-described vehicle panel structure is lightweight and inexpensive.

It is a schematic right view of the vehicle panel structure of 1st Embodiment. FIG. 2 is a schematic plan view of the vehicle panel structure shown in FIG. 1. It is a schematic top view of the vehicle panel structure of 2nd Embodiment. It is a schematic diagram of four analysis models created by the present inventors (third embodiment). It is a graph showing the relationship between an area ratio and a strain energy share. FIG. 4 is a schematic diagram of one of the four analysis models shown in FIG. 3 (fourth embodiment). It is the schematic of another analysis model created by the present inventors. It is the schematic of another analysis model created by the present inventors. It is a graph showing the relationship between the distance between the viscoelastic parts of the analysis model shown by FIG. 5A thru | or FIG. 5C, and strain energy share. It is a schematic plan view (section (a)), a front view (section (b)), and a right side view (section (c)) of the vehicle panel structure of the fifth embodiment. It is the schematic of the four analysis models created by the present inventors (sixth embodiment). It is a graph showing the relationship between an area ratio and a strain energy share. FIG. 9 is a schematic diagram of one of the four analysis models shown in FIG. 8 (seventh embodiment). It is the schematic of another analysis model created by the present inventors. It is the schematic of another analysis model created by the present inventors. It is a graph showing the relationship between the distance between the viscoelastic parts shown by FIG. 10A thru | or FIG. 10C, and a strain energy share rate. FIG. 8 is a schematic perspective view of a vehicle in which the vehicle panel structure shown in FIG. 7 is incorporated (eighth embodiment). FIG. 13 is a schematic enlarged view of the vehicle panel structure shown in FIG. 12. It is a schematic right view of the panel structure for vehicles of 9th Embodiment.

  Various features relating to the vehicle panel structure are described below. For the purpose of clarifying the terminology and direction, such as “left”, “right”, “front”, “rear”, “up” and “down”. Accordingly, these terms should not be used to limit the interpretation of the principles of the following embodiments.

<First Embodiment>
Unlike the prior art, the inventors of the present invention can effectively transmit vibration transmitted to the vehicle panel structure even if the viscoelastic member is not completely filled in the thin gap between the two panel members. Found to be attenuated. In the first embodiment, an exemplary vehicle panel structure is described.

  FIG. 1A is a schematic right side view of a vehicle panel structure (hereinafter referred to as “panel structure 100”) according to a first embodiment. FIG. 1B is a schematic plan view of the panel structure 100. The panel structure 100 will be described with reference to FIGS. 1A and 1B.

  The panel structure 100 includes two panel members 110 and 120 and two viscoelastic members 210 and 220. The panel member 110 is substantially equal in shape and size to the panel member 120. Each of the panel members 110 and 120 is a resin plate having high rigidity. For example, each of panel members 110 and 120 may be a plate material formed from fiber reinforced plastic. Preferably, each of panel members 110 and 120 is a plate material made of carbon fiber reinforced plastic. However, other resin materials that satisfy the rigidity required for the vehicle may be used for the panel members 110 and 120. Therefore, the principle of the present embodiment is not limited to a specific resin material used for the panel members 110 and 120.

  Each of the viscoelastic members 210 and 220 has lower rigidity than each of the panel members 110 and 120, but is superior to the panel members 110 and 120 in the damping characteristic that attenuates the vibration transmitted to the panel structure 100. Each of the viscoelastic members 210 and 220 may be formed of a rubber material such as styrene-butadiene rubber, chloroprene rubber, butyl rubber, nitrile rubber, or ethylene propylene rubber. However, other rubber materials that satisfy the vibration damping performance required for the vehicle may be used for the viscoelastic members 210 and 220. Therefore, the principle of this embodiment is not limited to a specific rubber material used for the viscoelastic members 210 and 220.

  Alternatively, each of the viscoelastic members 210 and 220 may be a polyester resin, a vinyl ester resin, a polyurethane resin, or other elastomer resin. Various resin materials that satisfy the vibration damping performance required for vehicles can be used as the viscoelastic members 210 and 220. Therefore, the principle of this embodiment is not limited to a specific resin material used for the viscoelastic members 210 and 220.

  Panel member 110 includes a peripheral surface 111, an upper surface 112, and a lower surface 113. The peripheral surface 111 forms a rectangular outline of the upper surface 112 and the lower surface 113. The upper surface 112 faces the panel member 120. The lower surface 113 forms a surface opposite to the upper surface 112. Similarly, the panel member 120 includes a peripheral surface 121, an upper surface 122, and a lower surface 123. The peripheral surface 121 of the panel member 120 forms a rectangular outline of the upper surface 122 and the lower surface 123 of the panel member 120. The lower surface 123 of the panel member 120 faces the upper surface 112 of the panel member 110. The upper surface 122 of the panel member 120 forms a surface opposite to the lower surface 123 of the panel member 120. Regarding the present embodiment, the first panel member is exemplified by one of the panel members 110 and 120. The second panel member is exemplified by the other of the panel members 110 and 120.

  When the panel structure 100 is incorporated in a vehicle (not shown), the peripheral surfaces 111 and 121 are constrained by a vehicle frame (not shown) and other parts (not shown) of the vehicle. The term “constrained” may mean a state in which the positional variation of the peripheral surfaces 111 and 121 is limited. That is, the peripheral surfaces 111 and 121 are firmly connected to a vehicle portion adjacent to the panel structure 100, and relative positional fluctuation therebetween hardly occurs. Regarding the present embodiment, the first peripheral edge is exemplified by one of the peripheral surfaces 111 and 121. The second peripheral portion is exemplified by the other of the peripheral surfaces 111 and 121.

  The thin space 130 is formed between the upper surface 112 surrounded by the peripheral surface 111 and the lower surface 123 surrounded by the peripheral surface 121. The viscoelastic members 210 and 220 are disposed in the space 130. Regarding the present embodiment, the first region is exemplified by one of the upper surface 112 and the lower surface 123. The second region is arranged by the other of the upper surface 112 and the lower surface 123.

  With respect to this embodiment, the viscoelastic members 210 and 220 are in direct contact with the upper surface 112 and the lower surface 123. However, another member (for example, a plate formed of a foam material) is inserted between the viscoelastic members 210 and 220 and the upper surface 112 and / or between the viscoelastic members 210 and 220 and the lower surface 123. Also good.

  1A and 1B show an orthogonal coordinate system set virtually. The z axis is set so as to pass through the centers of the upper surfaces 112 and 122 and the lower surfaces 113 and 123. The x axis is orthogonal to the z axis in the space 130. The y axis is orthogonal to the x axis and the z axis at the intersection of the x axis and the z axis. Each of the upper surface 112 of the panel member 110 and the lower surface 123 of the panel member 120 is a flat surface substantially parallel to a virtual plane defined by the x-axis and the y-axis. The x axis may be a virtual axis extending in the front-rear direction of the vehicle. In this case, the y-axis is a virtual axis extending in the vehicle width direction, and the z-axis is a virtual axis extending in the vehicle vertical direction. However, various definitions may be given for the Cartesian coordinate system. Therefore, the principle of the present embodiment is not limited to a specific definition related to the orthogonal coordinate system.

  As shown in FIG. 1B, the viscoelastic members 210 and 220 are rectangular (rectangular) having long sides extending in the extending direction of the x-axis. The terms “rectangular” and / or “rectangular” do not necessarily mean a rectangular (rectangular) in the mathematical sense. For example, the corners of the viscoelastic members 210 and 220 may be slightly curved.

  The viscoelastic member 210 is separated from the viscoelastic member 220 in the extending direction of the y-axis. Therefore, a gap band 131 that extends straight along the x-axis is formed between the viscoelastic members 210 and 220. The viscoelastic member 210 is arranged in line symmetry with the viscoelastic member 220 about the x axis. Regarding the present embodiment, the first viscoelastic member is exemplified by one of the viscoelastic members 210 and 220. The second viscoelastic member is exemplified by the other of the viscoelastic members 210 and 220.

  As shown in FIGS. 1A and 1B, the viscoelastic members 210 and 220 do not completely occupy the space 130. Therefore, the panel structure 100 is lighter than the conventional panel structure.

  1A and 1B indicate the distance between the viscoelastic members 210 and 220 by the symbol “DTC”. The designer may determine the distance DTC so as to suit the characteristics of the panel members 110 and 120 and the environment in which the panel structure 100 is used. If the panel members 110 and 120 are expected to be greatly distorted near the peripheral surfaces 111 and 121, the designer may set a large value for the distance DTC. If the panel members 110, 120 are expected to be greatly distorted near the central region of the panel members 110, 120, the designer may set a small value for the distance DTC. If the viscoelastic members 210 and 220 cover a region where the panel members 110 and 120 are greatly distorted, the viscoelastic members 210 and 220 can be distorted greatly. This means that the viscoelastic members 210 and 220 can effectively attenuate the vibration transmitted to the panel structure 100.

  With respect to the present embodiment, the viscoelastic members 210 and 220 are rectangular. However, the viscoelastic member may have other shapes. The viscoelastic member may be circular, elliptical, square, triangular or other polygonal. The principle of this embodiment is not limited to a specific shape of the viscoelastic member.

Second Embodiment
The vehicle panel structure may have more than two viscoelastic members. In this case, the designer can selectively arrange the viscoelastic member in a region where the panel member is largely distorted, while forming a space in a region where the panel member is not significantly distorted. As a result, the viscoelastic member can effectively attenuate the vibration transmitted to the vehicle panel structure, and the vehicle panel structure becomes very light. In the second embodiment, an exemplary vehicle panel structure having four viscoelastic members will be described.

  FIG. 2 is a schematic plan view of a vehicle panel structure (hereinafter referred to as “panel structure 100A”) according to the second embodiment. A panel structure 100A will be described with reference to FIGS. 1A and 2. The description of the above-described embodiment is applied to elements having the same reference numerals as those of the above-described embodiment.

  Similar to the first embodiment, the panel structure 100 </ b> A includes a panel member 110 and another panel member (not shown in FIG. 2) disposed on the panel member 110. The description of the first embodiment is applied to the panel member 110. The description regarding the panel member 120 described with reference to FIG. 1A is applied to another panel member.

  The panel structure 100A further includes four viscoelastic members 210A, 220A, 230A, and 240A. Each of the viscoelastic members 210A, 220A, 230A, and 240A may be formed of a rubber material such as styrene-butadiene rubber, chloroprene rubber, butyl rubber, nitrile rubber, or ethylene propylene rubber. However, other rubber materials that satisfy the vibration damping performance required for the vehicle may be used for the viscoelastic members 210A, 220A, 230A, and 240A. Therefore, the principle of this embodiment is not limited to the specific rubber material used for the viscoelastic members 210A, 220A, 230A, and 240A.

  Alternatively, each of the viscoelastic members 210A, 220A, 230A, 240A may be a polyester resin, a vinyl ester resin, a polyurethane resin, or other elastomer resin. Various resin materials that satisfy the vibration damping performance required for vehicles can be used as the viscoelastic members 210A, 220A, 230A, and 240A. Therefore, the principle of this embodiment is not limited to a specific resin material used for the viscoelastic members 210A, 220A, 230A, and 240A.

  Unlike the first embodiment, each of the viscoelastic members 210A, 220A, 230A, and 240A has a square shape in plan view. The term “square” does not necessarily mean a square in the mathematical sense. That is, the corners of the viscoelastic members 210A, 220A, 230A, and 240A may be slightly curved, or may be slightly different in the lengths of the sides.

  The orthogonal coordinate system described in connection with the first embodiment is also shown in FIG. The upper surface 112 of the panel member 110 is conceptually divided into four divided regions 141, 142, 143, and 144 by the x axis and the y axis. The divided area 141 corresponds to the fourth quadrant of the xy coordinates. The divided area 142 corresponds to the first quadrant of xy coordinates. The divided area 143 corresponds to the second quadrant of the xy coordinates. The divided area 144 corresponds to the third quadrant of the xy coordinates. With respect to the present embodiment, the first divided region is exemplified by the divided region 141. The second divided area is exemplified by the divided area 142. The third divided area is exemplified by the divided area 143. The fourth divided area is exemplified by the divided area 144.

  The viscoelastic member 210A is disposed between the divided region 141 and the lower surface of another panel member. The viscoelastic member 220A is disposed between the divided region 142 and the lower surface of the other panel member. The viscoelastic member 230A is disposed between the divided region 143 and the lower surface of the other panel member. 240 A of viscoelastic members are arrange | positioned between the division area 144 and the lower surface of another other panel member. Regarding the present embodiment, the first viscoelastic member is exemplified by a viscoelastic member 210A. The second viscoelastic member is exemplified by a viscoelastic member 220A. The third viscoelastic member is exemplified by a viscoelastic member 230A. The fourth viscoelastic member is exemplified by a viscoelastic member 240A.

  The viscoelastic members 210A, 220A, 230A, and 240A are separated from each other. The viscoelastic member 220A is arranged symmetrically with the viscoelastic member 210A about the x axis. The viscoelastic member 230A is arranged line-symmetrically with the viscoelastic member 220A with respect to the y-axis. The viscoelastic member 240A is arranged point-symmetrically with the viscoelastic member 220A around the z-axis. Therefore, a cross-shaped gap band 132 extending along the x-axis and the y-axis is formed between the viscoelastic members 210A, 220A, 230A, and 240A.

  Unlike the gap band 131 shown in FIG. 1A, the gap band 132 extends not only in the x-axis extending direction but also in the y-axis extending direction, and thus the panel structure 100A is very light.

  FIG. 2 shows the distance between the viscoelastic members 210A and 220A and the distance between the viscoelastic members 230A and 240A by the symbol “DTY”. FIG. 2 shows the distance between the viscoelastic members 210A and 240A and the distance between the viscoelastic members 220A and 230A by the symbol “DTX”. The designer may determine the distances DTX and DTY so as to suit the characteristics of the panel member 110 and another panel member and the environment in which the panel structure 100A is used. If the panel member 110 and another panel member are expected to be greatly distorted near the periphery, the designer may set a large value for each of the distances DTX and DTY. If the panel member 110 and another panel member are expected to be greatly distorted near the central region, the designer may set a small value for the distances DTX, DTY. If the viscoelastic members 210A, 220A, 230A, and 240A cover a region where the panel member 110 and the other panel member are greatly distorted, the viscoelastic members 210A, 220A, 230A, and 240A can also be greatly distorted. This means that the viscoelastic members 210A, 220A, 230A, and 240A can effectively attenuate the vibration transmitted to the panel structure 100A.

<Third Embodiment>
The inventors have created various analysis models that simulate the vehicle panel structure described in connection with the second embodiment, and set an appropriate ratio of the sum of the areas of the plurality of viscoelastic members to the area of the panel member. Verified. In 3rd Embodiment, the suitable ratio of the area sum of the several viscoelastic member with respect to the area of a panel member is demonstrated.

  FIG. 3 shows four analysis models 301, 302, 303, and 304 created by the present inventors. The analysis models 301, 302, 303, and 304 are described with reference to FIGS. 1A, 2 and 3. FIG.

  The analysis model 301 includes four viscoelastic portions 311, 312, 313, and 314. The viscoelastic portions 311, 312, 313 and 314 are equal in area. The viscoelastic portions 311, 312, 313, and 314 correspond to the viscoelastic members 210 </ b> A, 220 </ b> A, 230 </ b> A, and 240 </ b> A described with reference to FIG. 2, respectively. The viscoelastic portions 311, 312, 313 and 314 are equal in area. FIG. 3 shows the total area of the viscoelastic portions 311, 312, 313, and 314 by the symbol “TS1”. The area TS1 corresponds to the area of the upper surface 112 of the panel member 110 covered with the viscoelastic members 210A, 220A, 230A, and 240A.

  The analysis model 302 includes four viscoelastic portions 321, 322, 323, and 324. The viscoelastic portions 321, 322, 323 and 324 are equal in area. The viscoelastic portions 321, 322, 323, and 324 correspond to the viscoelastic members 210A, 220A, 230A, and 240A described with reference to FIG. The viscoelastic portions 321, 322, 323 and 324 are equal in area. FIG. 3 shows the total area of the viscoelastic portions 321, 322, 323, and 324 by the symbol “TS2”. The area TS2 corresponds to the area of the upper surface 112 of the panel member 110 covered with the viscoelastic members 210A, 220A, 230A, and 240A.

  The analysis model 303 includes four viscoelastic portions 331, 332, 333, and 334. The viscoelastic portions 331, 332, 333, and 334 are equal in area. The viscoelastic portions 331, 332, 333, and 334 correspond to the viscoelastic members 210A, 220A, 230A, and 240A described with reference to FIG. The viscoelastic portions 331, 332, 333, and 334 are equal in area. FIG. 3 shows the total area of the viscoelastic portions 331, 332, 333, and 334 by the symbol “TS3”. The area TS3 corresponds to the area of the upper surface 112 of the panel member 110 covered with the viscoelastic members 210A, 220A, 230A, and 240A.

  The analysis model 304 includes one viscoelastic part 340. FIG. 3 shows the area of the viscoelastic portion 340 with the symbol “TS4”. The area TS4 is the largest among the areas TS1, TS2, TS3, TS4. The area TS1 is the smallest among the areas TS1, TS2, TS3, TS4. The area TS3 is larger than the area TS2.

  The viscoelastic portions 311 to 314, 321 to 324, 331 to 334, and 340 are different from each other only in area, but are equal to each other in other characteristics (for example, viscoelastic characteristics and rigidity).

  Each of the analysis models 301, 302, 303, 304 includes a panel pair 350. The panel pair 350 corresponds to the set of the panel members 110 and 120 described with reference to FIG. 1A. Each of the viscoelastic portions 311 to 314, 321 to 324, 331 to 334, and 340 is interposed between the panel pair 350. The area of the panel pair 350 coincides with the viscoelastic part 340 (that is, the area TS4). With respect to the analysis model 304, the viscoelastic portion 340 completely overlaps the panel pair 350, so the panel pair 350 is not shown in FIG.

  The present inventors have found that the strain energy when the twisting force around the x-axis is applied to the analysis models 301, 302, 303, 304 under the condition that the peripheral edge that describes the rectangular outline of the panel pair 350 is constrained. Was analyzed. The torsional force given at the time of analysis is equal among the analysis models 301, 302, 303, and 304. The inventors calculated the strain energy share from the analysis result. The strain energy sharing ratio may be defined by the following mathematical formula.

  FIG. 4 is a graph showing the relationship between the area ratio and the strain energy share. With reference to FIG.3 and FIG.4, the relationship between an area ratio and a strain energy share rate is demonstrated.

  The horizontal axis of the graph shown in FIG. 4 represents the ratio (area ratio) of the areas TS1, TS2, TS3, TS4 of the viscoelastic portions 311 to 314, 321-324, 331 to 334, 340 with respect to the area of the panel pair 350. . The vertical axis of the graph shown in FIG. 4 is the strain energy sharing ratio obtained from the above formula.

  As shown in FIG. 4, the strain energy share has a peak value in the area ratio range of 10% to 50%. In particular, the strain energy sharing ratio takes a large value in the range of 12.5% to 30%.

  The damping performance of the panel structure may be defined as the following increase function F: If the value of the increase function F is large, the panel structure can effectively attenuate the vibration.

  As described in connection with the above-described embodiment, the panel member has a very high rigidity, so that the attenuation coefficient of the panel member is much smaller than the attenuation coefficient of the viscoelastic member. Therefore, the damping performance is mainly determined by the strain energy sharing ratio of the viscoelastic member.

  Since the damping coefficient is constant among the analysis models 301, 302, 303, and 304, a high strain energy sharing ratio means excellent damping performance against vibration. Therefore, the analysis model 302 has the most excellent attenuation performance among the analysis models 301, 302, 303, and 304 shown in FIG.

<Fourth embodiment>
In addition to the analysis described in relation to the third embodiment, the present inventors verified an appropriate distance between a plurality of viscoelastic members. In the fourth embodiment, an appropriate distance between a plurality of viscoelastic members will be described.

  FIG. 5A shows the analytical model 302 described in connection with the third embodiment. The description of the third embodiment is applied to the analysis model 302.

  5B and 5C show other analysis models 305 and 306 created by the present inventors. The analysis models 302, 305, and 306 will be described with reference to FIGS. 2 and 5A to 5C.

  The analysis model 305 shown in FIG. 5B includes a panel pair 350, similar to the analysis model 302. The analysis model 305 further includes four viscoelastic portions 351, 352, 353, and 354 inserted between the panel pair 350. The viscoelastic portions 351, 352, 353, and 354 correspond to the viscoelastic members 210A, 220A, 230A, and 240A described with reference to FIG. The viscoelastic portions 351, 352, 353, and 354 differ from the viscoelastic portions 321, 322, 323, and 324 of the analysis model 302 only in positions. That is, the viscoelastic portions 351, 352, 353, and 354 coincide with the viscoelastic portions 321, 322, 323, and 324 in area, viscoelastic characteristics, and rigidity.

  The analysis model 306 shown in FIG. 5C includes a panel pair 350, similar to the analysis model 302. The analysis model 306 further includes four viscoelastic portions 361, 362, 363, 364 interposed between the panel pair 350. The viscoelastic portions 361, 362, 363, and 364 correspond to the viscoelastic members 210A, 220A, 230A, and 240A described with reference to FIG. The viscoelastic portions 361, 362, 363, 364 differ from the viscoelastic portions 321, 322, 323, 324 of the analysis model 302 only in position. That is, the viscoelastic portions 361, 362, 363, and 364 correspond to the viscoelastic portions 321, 322, 323, and 324 in area, viscoelastic characteristics, and rigidity.

  The Cartesian coordinate system described in connection with the above embodiments is shown in FIGS. 5A to 5C. The symbol “DXA” shown in FIG. 5A indicates the distance between the viscoelastic portions 321 and 324 and the distance between the viscoelastic portions 322 and 323, respectively. The symbol “DYA” shown in FIG. 5A indicates the distance between the viscoelastic portions 321 and 322 and the distance between the viscoelastic portions 323 and 324, respectively. The symbol “DXB” shown in FIG. 5B indicates the distance between the viscoelastic portions 351 and 354 and the distance between the viscoelastic portions 352 and 353, respectively. The symbol “DYB” shown in FIG. 5B indicates the distance between the viscoelastic portions 351 and 352 and the distance between the viscoelastic portions 353 and 354, respectively. The symbol “DXC” shown in FIG. 5C indicates the distance between the viscoelastic portions 361 and 364 and the distance between the viscoelastic portions 362 and 363, respectively. The symbol “DYC” shown in FIG. 5B indicates the distance between the viscoelastic portions 361 and 362 and the distance between the viscoelastic portions 363 and 364, respectively. The following inequality shows the relationship between these distances.

  The inventors have applied a twisting force around the x-axis to the analysis models 302, 305, and 306 under the analysis conditions described in connection with the third embodiment, and the distortion of these analysis models 302, 305, and 306. The energy share was calculated.

  FIG. 6 is a graph showing the relationship between the distance between the viscoelastic portions and the strain energy sharing rate. With reference to FIG. 5A thru | or FIG. 6, the relationship between the distance between viscoelastic parts and a strain energy share rate is demonstrated.

  Data point A shown in FIG. 6 corresponds to analysis model 302. Data point B shown in FIG. 6 corresponds to analysis model 305. Data point C shown in FIG. 6 corresponds to analysis model 306.

  Each of the viscoelastic portions 321 to 324, 351 to 354, and 361 to 364 is a square having a side having a length LTH. The horizontal axis of the graph shown in FIG. 6 represents the ratio of the width of the cruciform gap to the length LTH (hereinafter referred to as “gap width ratio”). FIG. 6 shows a calculation formula for the gap width ratio corresponding to the data points A, B, and C. FIG. The vertical axis of the graph in FIG. 6 indicates the strain energy sharing ratio obtained from the analysis models 302, 305, and 306.

  As shown in FIG. 6, the peak of the strain energy sharing ratio appears in the range of the void width ratio of 0.13 to 0.20. That is, if the width of the cross-shaped gap is set to be 0.13 times or more and 0.20 times that of the viscoelastic member, the strain energy sharing ratio can have a large value. As described in relation to the third embodiment, a large strain energy sharing ratio means excellent damping performance.

  5A to 5C show contour lines representing strain energy sharing ratios in the viscoelastic portions 321 to 324, 351 to 354, and 361 to 364, respectively. The viscoelastic portion 321 in FIG. 5A is divided into seven regions LV1, LV2, LV3, LV4, LV5, LV6, and LV7 by contour lines. The strain energy share is the smallest in the region LV1. The strain energy sharing ratio is the largest in the region LV7. The strain energy share is the second smallest in the region LV2. The strain energy sharing ratio is the second largest in the region LV6. The strain energy sharing ratio is the third smallest in the region LV3. The strain energy share is the third largest in the region LV5. The region LV <b> 7 extends in the extending direction of the x axis along the side facing the viscoelastic portion 322.

  The region LV7 shown in the viscoelastic portion 351 in FIG. 5B is much narrower than the region LV7 shown in the viscoelastic portion 321. This means that the panel pair 350 of the analysis model 302 is greatly distorted along the gap band formed between the viscoelastic portions 321 to 324, while the strain deformation of the panel pair 350 of the analysis model 305 is dense. It means that it is inhibited by the arranged viscoelastic parts 351, 352, 353, and 354. Therefore, a void width that is too narrow means that the damping performance is adversely affected.

  A region LV7 shown in the viscoelastic portion 361 of FIG. 5C is wider than the region LV7 shown in the viscoelastic portion 351 of FIG. 5B, but is narrower than the region LV7 shown in the viscoelastic portion 321. This result is due to the viscoelastic portion 361 being too far from the vicinity of the x-axis where the panel pair 350 is greatly distorted.

  FIG. 5A shows an alternate long and short dash line CDL that passes through the center of the viscoelastic portion 321 and is parallel to the x-axis. The viscoelastic portion 321 is conceptually divided into two regions 325 and 326 by a one-dot chain line CDL. Region 326 is closer to the x-axis than region 325. In order to increase the difference between the strain energy sharing rate generated in the region 326 and the strain energy sharing rate generated in the region 325 in the presence of the twisting force around the x-axis, the designer The position may be set. If the strain energy sharing rate generated in the region 326 is large and the strain energy sharing rate generated in the region 325 is small, the viscoelastic portion 321 can effectively attenuate the vibration. With respect to this embodiment, the first viscoelastic portion is illustrated by region 325. The second viscoelastic portion is exemplified by the region 326. The straight line is exemplified by a one-dot chain line CDL.

  As shown in FIG. 5A, the region LV <b> 1 with the lowest strain energy sharing ratio appears near the four corners of the panel pair 350. Therefore, the designer arranges the viscoelastic portions 321, 322, 323, and 324 at positions that are separated from the four corners of the panel pair 350 and that the distortion deformation of the panel pair 350 is not excessively hindered. May be. As a result, a region where a high strain energy sharing ratio appears can occupy large portions of the viscoelastic portions 321, 322, 323, and 324.

<Fifth Embodiment>
With respect to the above-described embodiment, the two panel members sandwiching the plurality of viscoelastic members form a flat surface. Therefore, the vehicle panel structure described in relation to the above-described embodiment can be suitably used to form a substantially flat wide region such as a vehicle floor panel. However, vehicles have not only flat areas but also curved areas (eg roofs). In a fifth embodiment, an exemplary vehicle panel structure having two panel members that form a curved surface is described.

  FIG. 7 is a schematic plan view (section (a)), front view (section (b)), and right side surface of a vehicle panel structure (hereinafter referred to as “panel structure 100B”) of a fifth embodiment. It is a figure (section (c)). With reference to FIG. 7, panel structure 100B will be described. The description of the above-described embodiment is applied to elements having the same reference numerals as those of the above-described embodiment.

  Similar to the second embodiment, the panel structure 100B includes four viscoelastic members 210A, 220A, 230A, and 240A. The description of the second embodiment is applied to the viscoelastic members 210A, 220A, 230A, and 240A.

  Panel structure 100B further includes two panel members 110B and 120B. The viscoelastic members 210A, 220A, 230A, and 240A are disposed between the panel members 110B and 120B. Panel member 110B is substantially equal in shape and size to panel member 120B. Each of the panel members 110B and 120B is a resin plate having high rigidity. For example, each of panel members 110B and 120B may be a plate material formed from fiber reinforced plastic. Preferably, each of panel members 110B and 120B is a plate material made of carbon fiber reinforced plastic. However, other resin materials that satisfy the rigidity required for the vehicle may be used for the panel members 110B and 120B. Therefore, the principle of this embodiment is not limited to a specific resin material used for the panel members 110B and 120B.

  As in the first embodiment, the panel members 110B and 120B include peripheral surfaces 111 and 121, respectively. The description of the first embodiment is applied to the peripheral surfaces 111 and 121.

  Panel member 110B further includes an upper surface 112B and a lower surface 113B. The peripheral surface 111 forms a rectangular outline of the upper surface 112B and the lower surface 113B. The upper surface 112B faces the panel member 120B. The lower surface 113B forms a surface opposite to the upper surface 112B.

  Panel member 120B further includes an upper surface 122B and a lower surface 123B. The peripheral surface 121 forms a rectangular outline of the upper surface 122B and the lower surface 123B. The lower surface 123B of the panel member 120B is opposed to the upper surface 112B of the panel member 110B. The upper surface 122B of the panel member 120B forms a surface opposite to the lower surface 123B of the panel member 120B.

  The orthogonal coordinate system described in connection with the first embodiment is shown in FIG. The upper surfaces 112B and 122B and the lower surfaces 113B and 123B are curved so as to protrude in the positive direction of the z-axis. Regarding the present embodiment, the first panel member is exemplified by the panel member 110B. The second panel member is exemplified by the panel member 120B.

  The thin space 130 </ b> B is formed between the upper surface 112 </ b> B surrounded by the peripheral surface 111 and the lower surface 123 </ b> B surrounded by the peripheral surface 121. The viscoelastic members 210 and 220 are disposed in the space 130B. For the present embodiment, the first region is illustrated by the top surface 112B. The second region is arranged by the lower surface 123B.

  The upper surfaces 112B and 122B and the lower surfaces 113B and 123B are substantially parallel to each other. Unlike the first embodiment, the space 130B between the upper surface 112B and the lower surface 123B is curved so as to protrude in the positive direction of the z-axis. The curvature of a curved surface (not shown: hereinafter referred to as “virtual curved surface”) virtually set at an intermediate position between the upper surface 112B and the lower surface 123B may be defined as the curvature of the panel structure 100B.

  The curvature of the virtual curved surface in the extending direction of the x axis may coincide with the curvature of the virtual curved surface in the extending direction of the y axis. In this case, the panel structure 100B forms part of the surface of the sphere. The curvature (> 0) of the virtual curved surface in the extending direction of the x axis may not coincide with the curvature (> 0) of the virtual curved surface in the extending direction of the y axis. In this case, the panel structure 100B forms part of the surface of an elliptic sphere.

  Regarding this embodiment, the curvature of the virtual curved surface in the extending direction of the x-axis and the y-axis is set to a value larger than “0”. However, one of the curvatures of the virtual curved surface in the extending direction of the x-axis and the y-axis may be set to “0”. In this case, the vehicle panel structure can be used as a plate member curved along the x-axis or the y-axis. If the curvature of the virtual curved surface in the extending direction of the x-axis and the y-axis is both set to “0”, the designer follows the design principle described in relation to the first to fourth embodiments. Based on this, the vehicle panel structure can be designed.

  Regarding the present embodiment, each of the viscoelastic members 210A, 220A, 230A, 240A is in direct contact with the upper surface 112B and the lower surface 123B. However, other members (for example, a plate formed of a foam material) may be provided between the viscoelastic members 210A, 220A, 230A, 240A and the upper surface 112B and / or the viscoelastic members 210A, 220A, 230A, 240A and the lower surface 123B. May be inserted between the two.

  Similar to the second embodiment, the viscoelastic members 210A, 220A, 230A, and 240A are separated from each other in the space 130B. Therefore, the panel structure 100B is much lighter than the conventional vehicle panel structure completely filled with the viscoelastic member.

  The description of the second embodiment is applied to the arrangement pattern of the viscoelastic members 210A, 220A, 230A, and 240A on the orthogonal coordinate system. Therefore, a cross-shaped gap band 132B is formed between the viscoelastic members 210A, 220A, 230A, and 240A. Unlike the second embodiment, the cross-shaped gap band 132B is curved in the extending direction of the x-axis and the y-axis.

  Since the panel members 110B and 120B are curved, the panel structure 100B is present in the presence of a twisting force around the x-axis and / or the y-axis, as compared with the vehicle panel structure described in relation to the second embodiment. It is hard to be distorted. Therefore, the panel structure 100B can have a relatively high rigidity.

<Sixth Embodiment>
The inventors have created various analysis models that simulate the vehicle panel structure described in connection with the fifth embodiment, and set an appropriate ratio of the sum of the areas of the plurality of viscoelastic members to the area of the panel member. Verified. In the sixth embodiment, an appropriate ratio of the area sum of the plurality of viscoelastic members to the area of the panel member will be described.

  FIG. 8 shows four analysis models 401, 402, 403, 404 created by the present inventors. The analysis models 401, 402, 403, and 404 will be described with reference to FIGS.

  The analysis model 401 includes four viscoelastic portions 411, 412, 413, and 414. The viscoelastic portions 411, 412, 413, and 414 are equal to each other in area. The viscoelastic portions 411, 412, 413, and 414 correspond to the viscoelastic members 210A, 220A, 230A, and 240A described with reference to FIG. The viscoelastic portions 411, 412, 413, and 414 are equal to each other in area. FIG. 8 shows the total area of the viscoelastic portions 411, 412, 413, and 414 by the symbol “TS1”. The area TS1 corresponds to the area of the upper surface 112B of the panel member 110B covered with the viscoelastic members 210A, 220A, 230A, and 240A.

  The analysis model 402 includes four viscoelastic portions 421, 422, 423, and 424. The viscoelastic portions 421, 422, 423, and 424 are equal in area. The viscoelastic portions 421, 422, 423, and 424 correspond to the viscoelastic members 210A, 220A, 230A, and 240A described with reference to FIG. The viscoelastic portions 421, 422, 423, and 424 are equal in area. FIG. 8 shows the total area of the viscoelastic portions 421, 422, 423, 424 by the symbol “TS2”. The area TS2 corresponds to the area of the upper surface 112B of the panel member 110B covered with the viscoelastic members 210A, 220A, 230A, and 240A.

  The analysis model 403 includes four viscoelastic portions 431, 432, 433, and 434. The viscoelastic portions 431, 432, 433, and 434 are equal in area. The viscoelastic portions 431, 432, 433, and 434 respectively correspond to the viscoelastic members 210A, 220A, 230A, and 240A described with reference to FIG. The viscoelastic portions 431, 432, 433, and 434 are equal in area. FIG. 8 shows the total area of the viscoelastic portions 431, 432, 433, and 434 by the symbol “TS3”. The area TS3 corresponds to the area of the upper surface 112B of the panel member 110B covered with the viscoelastic members 210A, 220A, 230A, and 240A.

  The analysis model 404 includes one viscoelastic portion 440. FIG. 8 shows the area of the viscoelastic portion 440 by the symbol “TS4”. The area TS4 is the largest among the areas TS1, TS2, TS3, TS4. The area TS1 is the smallest among the areas TS1, TS2, TS3, TS4. The area TS3 is larger than the area TS2.

  The viscoelastic portions 411 to 414, 421 to 424, 431 to 434, and 440 are different from each other only in area, but are equal to each other in other characteristics (for example, viscoelastic characteristics and rigidity).

  Each of the analysis models 401, 402, 403, 404 includes a panel pair 450. The panel pair 450 corresponds to the set of panel members 110B and 120B described with reference to FIG. Each of the viscoelastic portions 411 to 414, 421 to 424, 431 to 434, and 440 is interposed between the panel pair 450. The area of the panel pair 450 coincides with the viscoelastic portion 440 (that is, the area TS4). With respect to the analytical model 404, the viscoelastic portion 440 completely overlaps the panel pair 450, so the panel pair 450 is not shown in FIG.

  The present inventors have found that the strain energy when the twisting force around the x-axis is applied to the analysis models 401, 402, 403, 404 under the condition that the peripheral edge that describes the rectangular outline of the panel pair 450 is constrained. Was analyzed. The torsional force given at the time of analysis is equal between the analysis models 401, 402, 403, and 404. The curvature of the panel pair 450 in the extending direction of the x-axis was “0.17”. The curvature of the panel pair 450 in the extending direction of the y-axis was “0.46”.

  FIG. 9 is a graph showing the relationship between the area ratio and the strain energy sharing ratio. With reference to FIG.8 and FIG.9, the relationship between an area ratio and a strain energy share rate is demonstrated.

  The horizontal axis of the graph shown in FIG. 9 represents the ratio (area ratio) of the areas TS1, TS2, TS3, and TS4 of the viscoelastic portions 411 to 414, 421 to 424, 431 to 434, and 440 with respect to the area of the panel pair 450. . The vertical axis of the graph shown in FIG. 9 is the strain energy sharing ratio obtained from the mathematical formula described in relation to the third embodiment.

  Unlike the third embodiment, the data shown in FIG. 9 does not show a peak. The curve in the graph of FIG. 9 is an increasing function and is similar to a logarithmic function. The strain energy sharing ratio changes at a high level in an area of 12.5% or more. The strain energy sharing rate increases rapidly in the area ratio range of 0% to 12.5%. In addition, the strain energy share shows a significant increase even in the area ratio range of 12.5% to less than 25%. The strain energy sharing rate slightly increases in the range of the area ratio of 12.5% to 50%. On the other hand, the strain energy sharing ratio is substantially constant in the area ratio range exceeding 50%. From the graph of FIG. 9, it can be seen that an area ratio exceeding 50% increases the weight of the vehicle panel structure, but hardly contributes to the improvement of the damping performance. Therefore, if the viscoelastic member is disposed between curved panel members, the area ratio is preferably set in the range of 12.5% to 50%. More preferably, the area ratio may be set in a range of 25% to 50%.

<Seventh embodiment>
In addition to the analysis described in relation to the sixth embodiment, the present inventors verified an appropriate distance between a plurality of viscoelastic members. In the seventh embodiment, an appropriate distance between a plurality of viscoelastic members will be described.

  FIG. 10A shows the analytical model 402 described in connection with the sixth embodiment. The description of the sixth embodiment is applied to the analysis model 402.

  10B and 10C show four analysis models 405 and 406 created by the present inventors. The analysis models 402, 405, and 406 are described with reference to FIGS. 7 and 10A to 10C.

  The analysis model 405 shown in FIG. 10B includes a panel pair 450 similar to the analysis model 402. The analysis model 405 further includes four viscoelastic portions 451, 452, 453, and 454 interposed between the panel pair 450. The viscoelastic portions 451, 452, 453, and 454 correspond to the viscoelastic members 210A, 220A, 230A, and 240A described with reference to FIG. Viscoelastic portions 451, 452, 453, and 454 differ from viscoelastic portions 421, 422, 423, and 424 of analysis model 402 only in position. That is, the viscoelastic portions 451, 452, 453, and 454 coincide with the viscoelastic portions 421, 422, 423, and 424 in area, viscoelastic characteristics, and rigidity.

  The analysis model 406 shown in FIG. 10C includes a panel pair 450, similar to the analysis model 402. The analysis model 406 further includes four viscoelastic portions 461, 462, 463, and 464 interposed between the panel pair 450. The viscoelastic portions 461, 462, 463, and 464 correspond to the viscoelastic members 210A, 220A, 230A, and 240A described with reference to FIG. The viscoelastic portions 461, 462, 463, and 464 differ from the viscoelastic portions 421, 422, 423, and 424 of the analysis model 402 only in positions. That is, the viscoelastic portions 461, 462, 463, and 464 coincide with the viscoelastic portions 421, 422, 423, and 424 in area, viscoelastic characteristics, and rigidity.

  The Cartesian coordinate system described in connection with the above embodiment is shown in FIGS. 10A to 10C. The symbol “DXA” shown in FIG. 10A indicates the distance between the viscoelastic portions 421 and 424 and the distance between the viscoelastic portions 422 and 423, respectively. The symbol “DYA” shown in FIG. 10A indicates the distance between the viscoelastic portions 421 and 422 and the distance between the viscoelastic portions 423 and 424, respectively. The symbol “DXB” shown in FIG. 10B indicates the distance between the viscoelastic portions 451 and 454 and the distance between the viscoelastic portions 452 and 453, respectively. The symbol “DYB” shown in FIG. 10B indicates the distance between the viscoelastic portions 451 and 452 and the distance between the viscoelastic portions 453 and 454, respectively. The symbol “DXC” shown in FIG. 10C indicates the distance between the viscoelastic portions 461 and 464 and the distance between the viscoelastic portions 462 and 463, respectively. The symbol “DYC” shown in FIG. 10B indicates the distance between the viscoelastic portions 461 and 462 and the distance between the viscoelastic portions 463 and 464, respectively. The following inequality shows the relationship between these distances.

  The inventors have applied a twisting force around the x-axis to the analysis models 402, 405, and 406 under the analysis conditions described in connection with the sixth embodiment, and the distortion of these analysis models 402, 405, and 406. The energy share was calculated.

  FIG. 11 is a graph showing the relationship between the distance between the viscoelastic portions and the strain energy sharing rate. With reference to FIG. 10A thru | or FIG. 11, the relationship between the distance between viscoelastic parts and a strain energy share rate is demonstrated.

  Data point A shown in FIG. 11 corresponds to analysis model 402. A data point B shown in FIG. 11 corresponds to the analysis model 405. Data point C shown in FIG. 11 corresponds to analysis model 406.

  Each of the viscoelastic portions 421 to 424, 451 to 454, 461 to 464 is a square having sides with a length LTH. The horizontal axis of the graph shown in FIG. 11 represents the ratio of the width of the cross-shaped gap to the length LTH (hereinafter referred to as “gap width ratio”). FIG. 11 shows a calculation formula for the gap width ratio corresponding to the data points A, B, and C. FIG. The vertical axis of the graph in FIG. 11 indicates the strain energy share obtained from the analysis models 402, 405, and 406.

  10A to 10C, the panel pair 450 is equally divided into a first divided region 471, a second divided region 472, a third divided region 473, and a fourth divided region 474 by the x-axis and the y-axis. The The viscoelastic portions 421, 451, 461 are sandwiched between the panel pair 450 in the first divided region 471. The viscoelastic portions 422, 452, and 462 are sandwiched by the panel pair 450 in the second divided region 472. The viscoelastic portions 423, 453, and 463 are sandwiched by the panel pair 450 in the third divided region 473. The viscoelastic portions 424, 454, 464 are sandwiched between the panel pair 450 in the fourth divided region 474.

  The panel pair 450 includes a first corner portion 481, a second corner portion 482, a third corner portion 483, and a fourth corner portion 484. The first corner portion 481, the second corner The corner portion 482, the third corner portion 483, and the fourth corner portion 484 have rectangular outlines that are bent. The first corner portion 481 is one of the four corner portions of the first divided region 471. The second corner portion 482 is one of the four corner portions of the second divided region 472. The third corner portion 483 is one of the four corner portions of the third divided region 473. The third corner corner 483 is a diagonal of the first corner corner 481. The fourth corner portion 484 is one of the four corner portions of the fourth divided region 474. The fourth corner 484 is a diagonal of the second corner 482.

  Under the relationship shown in the above inequality, the centers of the viscoelastic portions 421, 422, 423, and 424 are the first corner portion 481, the second corner portion 482 in the analysis models 402, 405, and 406, The third corner 483 and the fourth corner 484 are closest to each other. The centers of the viscoelastic portions 461, 462, 463, and 464 are closest to the intersection of the x axis and the y axis in the analysis models 402, 405, and 406.

  As shown in FIG. 11, when the gap width ratio increases, the strain energy sharing rate also increases. This means that the four viscoelastic portions are located at the first corner portion 481, the second corner portion 482, and the third corner from the center of the panel pair 450 (ie, the intersection of the x axis, the y axis, and the z axis). If arranged near the corner 483 and the fourth corner 484, respectively, it means that the four viscoelastic portions can have a large strain energy share. As explained in connection with the above-described embodiment, a large strain energy sharing ratio means excellent damping performance.

  10A to 10C show contour lines representing strain energy sharing ratios in the viscoelastic portions 421 to 424, 451 to 454, 461 to 464, respectively. The viscoelastic part 421 in FIG. 10A is divided into seven regions LV1, LV2, LV3, LV4, LV5, LV6, and LV7 by contour lines. The strain energy share is the smallest in the region LV1. The strain energy sharing ratio is the largest in the region LV7. The strain energy share is the second smallest in the region LV2. The strain energy sharing ratio is the second largest in the region LV6. The strain energy sharing ratio is the third smallest in the region LV3. The strain energy share is the third largest in the region LV5. The region LV7 extends in the extending direction of the x axis along the side facing the viscoelastic portion 422.

  The panel pair 450 is curved downward along the x-axis and the y-axis from the center of the panel pair 450. Therefore, the region near the center of the panel pair 450 is least deformed in the panel pair 450. This is demonstrated by the fact that the smallest region LV1 in the strain energy sharing ratio appears near the center of the panel pair 450, as shown in FIGS. 10A to 10C.

  The contour lines in FIGS. 10A to 10C indicate strain energy that increases from the center of the panel pair 450 toward the first corner corner 481, the second corner corner 482, the third corner corner 483, and the fourth corner corner 484. It shows the pattern of share rate. This means that the curved panel pair 450 is closer to the first corner portion 481, the second corner portion 482, the third corner portion 483, and the fourth corner portion 484 than the center region of the panel pair 450. It shows that it is easy to bend. Accordingly, the four viscoelastic portions are arranged closer to the first corner portion 481, the second corner portion 482, the third corner portion 483, and the fourth corner portion 484 than the center of the panel pair 450, respectively. If so, the four viscoelastic portions can have a large strain energy share.

  FIG. 10A shows a one-dot chain line CDL that passes through the center of the viscoelastic portion 421 and is parallel to the x-axis. The viscoelastic portion 421 is conceptually divided into two regions 425 and 426 by a one-dot chain line CDL. Region 426 is closer to the x-axis than region 425. In order to increase the difference between the strain energy sharing rate generated in the region 425 and the strain energy sharing rate generated in the region 426 in the presence of the twisting force around the x-axis, the designer The position may be set. If the strain energy sharing rate generated in the region 425 is large and the strain energy sharing rate generated in the region 426 is small, the viscoelastic portion 421 can effectively attenuate the vibration. With respect to this embodiment, the first viscoelastic portion is exemplified by region 425. The second viscoelastic part is exemplified by region 426. The straight line is exemplified by a one-dot chain line CDL.

<Eighth Embodiment>
The vehicle panel structure described in relation to the fifth to seventh embodiments can be suitably used for a vehicle roof. In the eighth embodiment, a vehicle incorporating a vehicle panel structure will be described.

  FIG. 12 is a schematic perspective view of a vehicle VCL in which the panel structure 100B is incorporated. The vehicle VCL will be described with reference to FIG. The description of the above-described embodiment is applied to elements having the same reference numerals as those of the above-described embodiment.

  Panel structure 100B is used as a roof of vehicle VCL. The viscoelastic members 210A and 220A are located behind the viscoelastic members 230A and 240A. The viscoelastic members 210A and 240A are located to the left of the viscoelastic members 220A and 230A.

  The peripheral part of the panel structure 100B is connected to a pair of roof rails RFR. In addition, the panel structure 100B is connected to the windshield WSD and the rear window RWD via a front header (not shown) and a rear header (not shown).

  FIG. 13 is a schematic enlarged view of the panel structure 100B shown in FIG. With reference to FIG. 10A, FIG. 12 and FIG. 13, the structure of the peripheral portion of the panel structure 100B will be described.

  Panel members 110B and 120B are penetrated by rivets RVT at the peripheral edge. In addition, the adhesive layer AHL bonds the upper surface 112B of the panel member 110B and the lower surface 123B of the panel member 120B. Therefore, the panel members 110B and 120B are restrained at the peripheral edge of the panel structure 100B. Accordingly, conditions similar to those of the analysis model described in connection with the sixth embodiment and the seventh embodiment are created in the vehicle VCL. As a result, a distribution pattern similar to the distribution pattern of the strain burden rate described with reference to FIG. 10A appears in the viscoelastic members 210A, 220A, 230A, and 240B.

<Ninth Embodiment>
A large thickness may be required for the vehicle panel structure. However, the large thickness of the vehicle panel structure tends to result in a large weight of the vehicle panel structure. In the ninth embodiment, a lightweight vehicle panel structure having a large wall thickness will be described.

  FIG. 14 is a schematic right side view of a vehicle panel structure (hereinafter, referred to as “panel structure 100C”) according to a ninth embodiment. The panel structure 100C will be described with reference to FIG. The description of the above-described embodiment is applied to elements having the same reference numerals as those of the above-described embodiment.

  As in the first embodiment, the panel structure 100C includes two panel members 110 and 120 and two viscoelastic members 210 and 220. The description of the first embodiment is applied to the panel members 110 and 120 and the viscoelastic members 210 and 220.

  The panel structure 100C further includes foam members 310 and 320. The foam member 310 is disposed between the viscoelastic members 210 and 220 and the upper surface 112 of the panel member 110. The foam member 320 is disposed between the viscoelastic members 210 and 220 and the lower surface 123 of the panel member 120. With respect to this embodiment, the first foam member is exemplified by one of the foam members 310 and 320. The second foam member is exemplified by the other of the foam members 310 and 320.

  The foam members 310 and 320 may be formed of a general foam plastic. For example, the foamed members 310 and 320 may be foamed plastics formed from a resin material such as polyurethane, polystyrene, polyolefin, phenol resin, polyvinyl chloride, urea resin, silicone, polyimide, and melamine resin.

  Since the panel structure 100C includes the foam members 310 and 320, it can have a large thickness. Since the foam members 310 and 320 contain bubbles, they are very lightweight. Therefore, the panel structure 100C does not become excessively heavy.

  The various features described above may be combined or modified to suit the overall design of various vehicles.

  With respect to the above-described embodiment, the edge of the viscoelastic member is substantially parallel to the edge of the panel member. However, the viscoelastic member may be arranged so that the edge of the viscoelastic member extends in a direction different from the edge of the panel member.

  With respect to the embodiments described above, the plurality of viscoelastic members are equal to one another in shape and size. However, the designer determines the shape and size of each of the plurality of viscoelastic members so as to meet various conditions such as the physical characteristics and shape characteristics of the panel members and the environment in which the vehicle panel structure is used. May be. Accordingly, one of the plurality of viscoelastic members may differ from the other one of the plurality of viscoelastic members in shape and / or size.

  The principle of the above-described embodiment is suitably used for panel members mounted on various vehicles.

100, 100A, 100B, 100C ... Panel structure (vehicle panel structure)
110 ... panel member (first or second panel member)
110B ... Panel member (first panel member)
111, 121 ... peripheral surface (first or second peripheral part)
112 ... upper surface (first or second region)
112B ... upper surface (first region)
120 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Panel member (second or first panel member)
120B ... Panel member (second panel member)
123 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Lower surface (second or first region)
123B ........... Bottom surface (second area)
131 ········································· ......・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Divided area (first divided area)
142 ........... Divided area (second divided area)
143 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Division area (third division area)
144... ...... Divided area (fourth divided area)
210 ... Viscoelastic member (first or second viscoelastic member)
210A ... Viscoelastic member (first viscoelastic member)
220 ... Viscoelastic member (second or first viscoelastic member)
220A ... Viscoelastic member (second viscoelastic member)
230A ... Viscoelastic member (third viscoelastic member)
240A ... Viscoelastic member (4th viscoelastic member)
310 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Foam member (first or second foam member)
311 to 314 Viscoelastic part (first to fourth viscoelastic members)
320 ................ Foam member (second or first foam member)
321-324 ... Viscoelastic part (first to fourth viscoelastic members)
331-334 ..... Viscoelastic part (1st-4th viscoelastic member)
350 ..... Panel pair (first and second panel members)
351-354 ... Viscoelastic part (first to fourth viscoelastic members)
361-364 Viscoelastic part (first to fourth viscoelastic members)
411-414 Viscoelastic part (1st-4th viscoelastic member)
421 to 424 ... Viscoelastic part (first to fourth viscoelastic members)
431-434 ..... Viscoelastic part (1st-4th viscoelastic member)
450 ... Panel pair (first and second panel members)
451-454 ..... Viscoelastic part (1st-4th viscoelastic member)
461-464 Viscoelastic part (first to fourth viscoelastic members)
471 ... 1st divided area 472 ... 2nd divided area 473 ... ... 3rd divided area 474 ... 4th divided area 481 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ First corner 482 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Second corner 483・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 3rd corner 484 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 4th corner

Claims (4)

A curved surface having a constrained first peripheral edge and a rectangular outline having a first corner, a second corner, a third corner, and a fourth corner formed by the first peripheral. A first region member made of a resin having a first region,
A resin-made second panel having a second peripheral edge constrained together with the first peripheral edge, and a second region that is surrounded by the second peripheral edge and forms a curved surface facing the first region. Members,
A plurality of viscoelastic members disposed apart from each other in a space formed between the first region and the second region and covering an area of 12.5% or more and 50% or less of the first region ; With
The first region is virtually set to be orthogonal to the z-axis that is virtually set to pass through the center of the first region and the center of the second region in the space. The first divided region, the second divided region, the first divided region, and the y axis that is virtually set to be orthogonal to the z axis and the x axis at the intersection of the z axis and the x axis. It is conceptually divided into three divided areas and a fourth divided area,
Said plurality of viscoelastic members, the first viscoelastic member disposed between the first divided region and the second region, which is disposed between the second divided region and the second region 2 viscoelastic member, a fourth viscoelastic disposed between the third divided region and the third viscoelastic member and the fourth divided region and the second region arranged between the second region It consists only of members,
The first corner is a corner of the first divided region,
The second corner is a corner of the second divided region,
The third corner is a corner of the third divided region;
The fourth corner is a corner of the fourth divided region;
The first viscoelastic member is disposed closer to the first corner than the intersection;
The second viscoelastic member is disposed closer to the second corner than the intersection,
The third viscoelastic member is disposed closer to the third corner than the intersection;
The fourth viscoelastic member is a vehicle panel structure that is disposed closer to the fourth corner than the intersection . A resin-made first panel member having a constrained first peripheral edge and a first region forming a plane surrounded by the first peripheral edge;
A resin-made second panel having a second peripheral edge constrained together with the first peripheral edge, and a second region that is surrounded by the second peripheral edge and forms a plane opposite to the first region. Members,
A plurality of viscoelastic members disposed apart from each other in a space formed between the first region and the second region and covering an area of 10% to 50% of the first region. ,
The first region is virtually set to be orthogonal to the z-axis that is virtually set to pass through the center of the first region and the center of the second region in the space. The first divided region, the second divided region, the first divided region, and the y axis that is virtually set to be orthogonal to the z axis and the x axis at the intersection of the z axis and the x axis. It is conceptually divided into three divided areas and a fourth divided area,
The plurality of viscoelastic members include a first viscoelastic member disposed between the first divided region and the second region, and a second disposed between the second divided region and the second region. Only the viscoelastic member, the third viscoelastic member disposed between the third divided region and the second region, and the fourth viscoelastic member disposed between the fourth divided region and the second region. Consists of
The first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member have a square shape,
The second viscoelastic member is arranged in a line-symmetrical position with the first viscoelastic member with respect to the x axis,
The third viscoelastic member is disposed at a position symmetrical with the second viscoelastic member with respect to the y-axis,
The fourth viscoelastic member is disposed at a point-symmetrical position with the second viscoelastic member around the z-axis,
Between the first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member, a cruciform shape extending along the x-axis and the y-axis with a predetermined width. A void zone is formed,
The square shapes of the first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member have sides of a predetermined length,
The vehicle panel structure wherein the predetermined width is not less than 0.13 times and not more than 0.20 times the predetermined length . Each of the first region and the second region is rectangular.
The first viscoelastic member, the second viscoelastic member, the third viscoelastic member, and the fourth viscoelastic member are separated from four corners of each of the first region and the second region.
The vehicle panel structure according to claim 2 . A first foam member disposed between the first region and the plurality of viscoelastic members;
A second foam member disposed between the second region and the plurality of viscoelastic members.
The vehicle panel structure according to any one of claims 1 to 3 .

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