JP2009154744A - Body structure for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To damp a propagation sound propagating from the outside of an automobile and, if kept intact, coming into the inside of the automobile, while reducing weight. <P>SOLUTION: In a front door 20, at least a main part (a first door constituent 22) is formed of a honeycomb structure 23 made of a synthetic resin. The honeycomb structure 23 consists of a honeycomb part 24 made up of a plurality of cells 26 demarcated from each other by a partition wall 25 to form a cylindrical shape and a pair of sealing plate parts 27, 28 for sealing each cell 26 by sandwiching the honeycomb part 24 from both sides thereof. The honeycomb structure 23 is arranged so as to place one sealing plate part 27 on the outside of the automobile and the other sealing plate part 28 on the inside of the automobile. The sealing plate part 27 on the outside of the automobile is provided with a communication hole part 63 for communicating with the outside of the sealing plate part 27 and each cell 26 in the honeycomb part 24. The communication hole part 63 is made to function as a resonance pipe for reducing propagation sound propagating from the outside of the automobile to the honeycomb structure 23. The inside space 64 of the cell 26 is made to function as a resonance chamber. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an automobile body structure suitable as a structure constituting an automobile body such as an automobile door.

  In order to improve the fuel efficiency of automobiles, weight reduction of automobiles is an effective means. This is because if the vehicle is lightened, the energy required to operate the vehicle can be reduced. Methods for reducing the weight of automobiles include reducing the weight of materials, reducing the size and weight of each component, and reducing the number of components by improving functions.

In this regard, for example, Patent Document 1 proposes a technique for reducing the weight of the structure constituting the automobile body. In this automobile body structure, an iron pipe is disposed between the inner panel and the outer panel, and cushioning materials are disposed in passenger protection areas above and below the iron pipe. The cushioning material is composed of a honeycomb structure and a face material adhered to both surfaces thereof. In this body structure for automobiles, weight reduction is achieved by constituting a part of the cushioning material with a honeycomb structure. Further, when an impact is applied to the body structure for an automobile, the shock is absorbed by deformation of the cushioning material.
Japanese Patent Laid-Open No. 2004-255906

  However, in the technique described in Patent Document 1, although the body structure for automobiles can be lightened and the weight of the automobile can be reduced, and the fuel efficiency can be improved. This causes a new problem that the noise of the vehicle is easily propagated into the vehicle body structure and easily enters the vehicle.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a vehicle body structure capable of attenuating a propagation sound that propagates from the outside of the vehicle and enters the vehicle while reducing the weight. To provide a body.

  In order to achieve the above object, the invention according to claim 1 is characterized in that at least a main part is formed of a honeycomb structure made of a synthetic resin, and the honeycomb structure is partitioned by partition walls to form a cylindrical shape. A vehicle body structure comprising: a honeycomb portion composed of a plurality of cells; and a sealing plate portion that sandwiches the honeycomb portion from both sides and seals each cell, wherein one of the two sealing plate portions is located outside the vehicle. The honeycomb structure is disposed so that the other is located on the inner side of the vehicle, and on the sealing plate portion on the outer side of the vehicle, the outside of the sealing plate portion and at least some of the cells in the honeycomb portion By providing a communication hole portion that communicates with each other, the communication hole portion functions as a resonance tube for reducing the propagation sound that propagates from the outside of the vehicle to the honeycomb structure, and the internal space of the cell is propagated through the propagation space. And summarized in that to function as a resonance chamber for reducing.

The cells constituting the honeycomb structure generally indicate a hexagonal cylindrical shape, but may be a polygonal cylindrical shape other than a hexagonal shape or a cylindrical shape.
According to the above configuration, in the automobile body structure, the honeycomb structure constituting at least the main part thereof is formed of the synthetic resin, and the honeycomb structure includes the honeycomb part and the pair of sealing plate parts. Because it is lightweight.

  In addition, when propagation sound having a predetermined frequency characteristic generated outside the vehicle, such as traveling sound and wind noise, propagates to the body structure for an automobile, the communication hole portion of the sealing plate portion outside the vehicle in the honeycomb structure Functions as a resonance tube, and the internal space of the cell functions as a resonance chamber. Therefore, a predetermined frequency component determined by the internal volume of the internal space (resonance chamber) of the cell and the cross-sectional area and length of the communication hole (resonance tube) of the propagation sound is determined by the communication hole and the cell. It is reduced by the resonance effect of the internal space. As a result, the propagation sound that propagates from outside the vehicle and attempts to enter the vehicle is attenuated.

  According to a second aspect of the present invention, in the first aspect of the present invention, an outer panel having a design surface as an outer surface of the vehicle is provided on the outer side of the sealing plate portion provided with the communication hole portion. The gist is that it is arranged.

  According to the above configuration, since the communication hole portion is provided in the sealing plate portion outside the vehicle in the honeycomb structure, if the outer surface of the sealing plate portion is a design surface, Therefore, the communication hole portion is present and the appearance is impaired. However, in the invention described in claim 2, the outer panel is further arranged on the vehicle outer side of the sealing plate portion, and the surface on the vehicle outer side is the design surface. This outer panel hides the communication hole portion of the sealing plate portion so that the communication hole portion cannot be seen from the outside of the vehicle body structure. Therefore, the appearance of the automobile body structure is determined solely by the outer surface of the outer panel, and deterioration of the appearance due to the communication hole is suppressed by the outer panel.

  The invention according to claim 3 is the invention according to claim 2, wherein support pillars are interposed at a plurality of locations between the outer panel and the sealing plate part having the communication hole part. Is the gist.

  According to said structure, the outer pillar is spaced apart from the sealing board part of a honeycomb structure to the vehicle outer side by interposing a support pillar part in the several places between an outer panel and a sealing board part. The space between the outer panel and the sealing plate portion allows the outer panel to bend toward the inside of the vehicle. Therefore, when a load is applied to the automobile body structure due to an impact from the outside of the vehicle, portions other than the support column portion of the outer panel are once bent toward the inside of the vehicle. When this load is removed, the outer panel tries to return to the state before being bent by its elastic restoring force.

The gist of the invention described in claim 4 is that, in the invention described in claim 3, the outer panel is made of a synthetic resin plate having flexibility.
By forming the outer panel with a flexible synthetic resin plate, the outer panel can bend flexibly according to the load when a load is applied, but its own elastic restoring force when the load is removed. This ensures that the original state is restored. In addition, since the outer panel is formed of a synthetic resin, the body structure for automobiles can be further reduced in weight.

  According to the present invention, at least a main part is constituted by a honeycomb structure made of a synthetic resin, and further, a communication hole functioning as a resonance tube is provided in a sealing plate part on the vehicle outer side, and the internal space of the cell is used as a resonance chamber. Since it is made to function, the propagation sound which propagates from the outside of a vehicle and tries to enter the inside of the vehicle can be attenuated while reducing the weight.

Hereinafter, an embodiment in which the body structure for an automobile of the present invention is embodied in a front door of an automobile will be described with reference to FIGS.
As shown by a two-dot chain line in FIGS. 5 and 6, in the body 11 of the automobile, an opening 12 serving as a passenger's elevator is provided near the side of the front seat (driver's seat, passenger seat). The front door 20 of the present embodiment is for opening and closing the opening 12 by approaching and separating from the periphery of the opening 12 at the periphery thereof.

  The front door 20 includes a door main body 21 that is a main part thereof, a windshield FG provided on the upper side of the door main body 21, and an adjacent to the upper side of the door main body 21 so as to surround the windshield FG. And a window frame portion 33 surrounding the frame. The door main body 21 is supported in the vicinity of the front edge 13 of the opening 12 so as to be openable and closable by a door hinge 51 provided at the front end thereof.

  The vehicle outer side part which forms the main part of the door main body 21 is constituted by a first door structure 22 made of fiber reinforced resin. The first door structure 22 is formed by an injection molding method. The fiber reinforced resin is a composite material containing a synthetic resin such as PP, PA, or PET as a base material, and a fiber such as carbon fiber or glass fiber having a relatively short fiber length as a reinforcing material. This fiber length is set on condition that it does not hinder the molding of the first door component 22 by the injection molding method, and is desirably 50 μm to 2000 μm.

  The substantially entire first door structure 22 is formed by a honeycomb structure 23. As shown in at least one of FIGS. 3, 7, and 10 (A), the honeycomb structure 23 includes a honeycomb portion 24 and a pair of sealing plate portions 27 and 28. The honeycomb portion 24 is composed of a large number of cells 26 having a hexagonal cylindrical shape partitioned by partition walls 25. A large number of cells 26 are joined side by side in parallel, and the honeycomb portion 24 has a honeycomb shape as a whole. The length L1 of one side at the open end of each cell 26 is set to about 50 mm. The inside of the cell 26 is a space having a predetermined internal volume. The sealing plate portions 27 and 28 are located on both sides of the honeycomb portion 24 in the height direction of the cells 26 (left and right direction in FIG. 7) and seal the cells 26. In the present embodiment, the honeycomb portion 24 and the sealing plate portion 28 on the vehicle interior are integrally formed. The sealing plate portion 27 on the outside of the vehicle is formed separately from the honeycomb portion 24 and is joined to the honeycomb portion 24 by means such as welding or adhesion after the formation.

  As shown in at least one of FIGS. 1 and 2, a cylindrical frame portion 29 having a hollow interior is provided at the lower end portion and the rear end portion of the first door structure 22. The tubular frame portion 29 is not constituted by the honeycomb structure 23. Locking holes 31 for locking a clip (not shown) for attaching a door trim, which will be described later, are provided at a plurality of locations of the cylindrical frame portion 29.

  Further, a portion of the door main body 21 that is closer to the vehicle interior than the first door component 22 (hereinafter referred to as “vehicle inner portion 32”) and the upper window frame portion 33 are the same as the first door component 22. It is comprised by the 2nd door structure 34 which consists of the same fiber reinforced resin. The second door structure 34 is also formed by an injection molding method. The window frame part 33 is formed narrow along the periphery of the windshield FG.

  The vehicle interior portion 32 of the second door structure 34 has a function of increasing the strength of the door main body 21 together with the first door structure 22, and functional parts on the vehicle interior side of the first door structure 22 are fastened. It functions as a location. In a region R (see FIG. 1) in the vicinity of the vehicle interior side of the first door structure 22, at least a part of the vehicle interior portion 32 of the second door structure 34 passes through the central portion of the region R and is the same region. Of the outer edge of R, it is provided at a location reaching the vicinity of the portion facing each other in the front-rear direction.

  As a form that satisfies this condition, in this embodiment, the vehicle interior portion 32 is formed in a substantially rectangular frame shape. More specifically, the vehicle interior portion 32 has a pair of pillar portions (a front pillar portion 35 and a rear pillar portion 36) in a portion of the region R facing each other in the front-rear direction of the outer edge portion. The front and rear pillar portions 35 and 36 extend substantially in the vertical direction, and their upper end portions are located at the upper end portion of the first door structure 22. In addition, the vehicle interior portion 32 has an upper bridge portion 37 that spans between the upper end portion of the front column portion 35 and the upper end portion of the rear column portion 36, which is the outer edge portion of the region R. Further, in the vehicle interior portion 32, only the lower bridge portion 38 spanned between the front pillar portion 35 and the rear pillar portion 36 is provided in the central portion and the peripheral portion (excluding the outer edge portion) of the region R. Have. These front and rear pillar portions 35 and 36 and the upper and lower bridge portions 37 and 38 are formed wider than the window frame portion 33.

  As shown in at least one of FIGS. 4 to 7, substantially the entire second door structure 34 (the vehicle interior portion 32 and the window frame portion 33) is formed by a honeycomb structure 41. The honeycomb structure 41 includes the same structure as the honeycomb structure 23 in the first door structure 22, that is, a honeycomb portion 42 and a pair of sealing plate portions 46 and 47. The honeycomb part 42 includes a large number of hexagonal cylindrical cells 44 and 45 that are partitioned from each other by partition walls 43.

  However, the sizes of the cells 44 and 45 are different between the vehicle interior portion 32 and the window frame portion 33. As shown in FIG. 10B, the length L2 of one side of the cell 44 in the vehicle interior portion 32 is set to about 25 mm, which is shorter than the length L1 of one side of the cell 26 in the first door structure 22. . This is because one side is shortened to make the cell 44 smaller, so that in the vehicle interior portion 32 (front and rear pillar portions 35 and 36 and upper and lower both bridge portions 37 and 38) which are not so wide, the cell 44 is formed in the width direction. This is to secure the strength of the vehicle interior side portion 32 by arranging at least a plurality of the above.

  Further, as shown in FIG. 10C, the length L3 of one side of the cell 45 in the window frame portion 33 is set to about 15 mm, which is shorter than the length L2 of one side of the cell 44 in the vehicle interior portion 32. ing. This is because by shortening one side to make the cell 45 smaller, at least a plurality of cells 45 are arranged in the width direction in the narrow window frame portion 33 to ensure the strength of the window frame portion 33.

  As shown in at least one of FIGS. 7 and 8, the sealing plate portions 46 and 47 are located on both sides of the honeycomb portion 42 in the height direction of the cells 44 and 45 (the left-right direction in FIGS. 7 and 8). Each cell 44 (45) is sealed. In the present embodiment, the honeycomb portion 42 and one (inner side) sealing plate portion 47 are integrally formed. The other (vehicle outer side) sealing plate portion 46 is formed separately from the honeycomb portion 42. The sealing plate portion 46 on the vehicle exterior side is joined to the honeycomb portion 42 by means such as welding or adhesion.

  The first door structural body 22 and the second door structural body 34 (the vehicle interior portion 32) are mutually connected by means such as adhesion and welding at the adjacent sealing plate portions 28 and 46 of the honeycomb structures 23 and 41. (See FIG. 7).

  The door hinge 51 described above is one of the functional components located on the vehicle inner side than the first door structure 22 as shown in at least one of FIGS. 1 and 2. The door hinge 51 includes a pair of upper and lower hinge bodies 52 and 53 and a connecting portion 54 that extends in the vertical direction and connects the upper and lower hinge bodies 52 and 53. As shown in at least one of FIGS. 5, 6, and 8, the connecting portion 54 is fastened to the vehicle interior portion 32 by bolts 55 and nuts 56 at both upper and lower ends thereof. The upper and lower hinge bodies 52 and 53 protrude forward from the connecting portion 54 and are supported on the body 11 in the vicinity of the front end edge 13 of the opening 12 so as to be openable and closable (turnable). The connecting portion 54 is provided with a locking hole 57 similar to the cylindrical frame portion 29 of the first door constituting body 22 described above (see FIG. 1).

  A synthetic resin door trim 58 is disposed on the vehicle inner side of the vehicle inner side portion 32 as shown by a two-dot chain line in FIGS. 5 and 6. The door trim 58 is also one of the functional components located on the vehicle inner side than the first door structure 22. The inner surface of the door trim 58 constitutes a design surface. Here, an armrest 59 is formed integrally with the door trim 58. The door trim 58 is attached to the cylindrical frame portion 29 by locking a plurality of clips (not shown) in the locking holes 31 and 57 at the plurality of locations, and via the connecting portion 54 of the door hinge 51. Fastened to the second door structure 34.

  As shown in FIGS. 1 and 2, an impact beam 62 made of fiber reinforced resin is disposed in the vicinity of the vehicle interior side of the first door structure 22. The fiber reinforced resin used here contains a fiber such as carbon fiber or glass fiber having a longer fiber length than the fiber in the fiber reinforced resin in the first door structure 22 and the second door structure 34 and is reinforced. Synthetic resin. The impact beam 62 is formed of a plate-like body extending substantially in the front-rear direction, the front end thereof is located at the front end portion of the first door component 22, and the rear end of the impact beam 62 is located at the rear end portion of the first door component 22. positioned. The impact beam 62 is formed by a molding method different from the first door structure 22 and the second door structure 34, for example, compression molding, extrusion molding, or the like. The impact beam 62 is fixed to the inner surface of the first door structure 22 by bonding, welding, or the like.

  In addition to the above configuration, in the present embodiment, as shown in at least one of FIGS. 7 to 9, the sealing plate portion 27 on the vehicle exterior side of the first door structure 22 is connected to the outside of the sealing plate portion 27. A communication hole 63 is provided to communicate with each cell 26 in the honeycomb part 24. The communication hole portion 63 is provided for all the cells 26 in the honeycomb portion 24, and the opening area is set smaller than the area of the open end of the cell 26. With this configuration, each communication hole 63 is caused to function as a resonance tube for reducing the propagation sound that propagates from the outside of the vehicle to the honeycomb structure 23 and thus the front door 20 and enters the vehicle. . Further, the internal space 64 of each cell 26 is made to function as a resonance chamber for reducing the propagation sound.

  Further, an outer panel 65 made of a flexible synthetic resin plate is disposed on the vehicle exterior side of the sealing plate portion 27 as a part of the door main body portion 21. The outer surface (outer surface 65 </ b> A) of the outer panel 65 forms a design surface of the door body 21. Support pillar portions 66 are interposed at a plurality of locations between the outer panel 65 and the sealing plate portion 27. These support pillars 66 may be provided on the outer panel 65, or conversely, may be provided on the sealing plate part 27. In the present embodiment, the support column portion 66 protrudes from a plurality of locations on the vehicle inner surface of the outer panel 65 toward the vehicle inner side. The outer panel 65 is fixed to the honeycomb structure 23 in a state where the plurality of support pillar portions 66 are in contact with the sealing plate portion 27. As described above, the support column portions 66 are interposed at a plurality of locations between the outer panel 65 and the sealing plate portion 27, so that the outer panel 65 is separated from the sealing plate portion 27 by a predetermined distance to the vehicle outer side. .

The front door 20 configured as described above is lightweight for the following reason.
(I) The substantially whole 1st door structure 22 which comprises the vehicle outer side part of the door main-body part 21 is formed of the synthetic resin.

(Ii) Substantially the entire second door structure 34 constituting the vehicle interior portion 32 and the window frame portion 33 is made of synthetic resin.
(Iii) The entire outer panel 65 is made of synthetic resin.

  (Iv) The substantially entire first door structure 22 and the substantially entire second door structure 34 are formed by the honeycomb structures 23 and 41, respectively. The honeycomb structures 23 and 41 are formed of a large number of cells 26, 44 and 45 having a hexagonal cylindrical shape, and the cells 26, 44 and 45 are sandwiched between the honeycomb portions 24 and 42 from both sides. It is comprised by a pair of sealing board part 27,28,46,47 which seals.

  By making each cell 26, 44, 45 a hexagonal cylinder, the volume of the internal space 64 can be maximized, and the material of the partition walls 25, 43 can be reduced. This leads to the honeycomb structures 23 and 41 becoming lighter.

  (V) In the region R in the vicinity of the vehicle inner side of the first door component 22, the second door component 34 has a pair of column portions (front and rear column portions 35, 36) opposite to each other on the front and rear of the outer edge portion. In the region R, the central portion and its peripheral portion (excluding the outer edge portion) have only a long lower bridge portion 38 spanned between the front and rear pillar portions 35 and 36. Not there.

Therefore, the front door 20 becomes lighter than when the second door structure 34 is provided over substantially the entire region R.
By the way, a propagation sound having a predetermined frequency characteristic generated outside the vehicle, such as a running sound of a car and a wind noise, propagates to the front door 20. However, the communication hole portion 63 of the sealing plate portion 27 outside the vehicle in the honeycomb structure 23 functions as a resonance tube, and the internal space 64 of the cell 26 functions as a resonance chamber. That is, the honeycomb structure 23 functions as a Helmholtz resonance box. Therefore, the communication hole portion 63 and the cell 26 are determined by the internal volume of the internal space 64 (resonance chamber) of the cell 26 and the cross-sectional area and length of the communication hole portion 63 (resonance tube) among the propagation sound. Resonates with a predetermined frequency component (resonance frequency), and the sound pressure level at the resonance frequency is reduced. Propagation sound that attempts to enter the vehicle through the front door 20 is attenuated.

  Here, since the communication hole portion 63 is provided in the sealing plate portion 27 outside the vehicle in the honeycomb structure 23 as described above, the outer surface (outer surface 27A) of the sealing plate portion 27 is temporarily assumed. Is a design surface, the communication hole portion 63 exists on the design surface, and the appearance is impaired. Although each communication hole 63 has a small diameter, the influence on the deterioration of the appearance of each communication hole 63 is small. However, the communication hole portion 63 is provided for each cell 26, and a large number exist in the sealing plate portion 27. Therefore, the degree of influence on the appearance deterioration of the front door 20 caused by these communication hole portions 63 cannot be ignored.

  However, in the present embodiment, the outer panel 65 is further arranged on the vehicle exterior side of the sealing plate portion 27, and the vehicle exterior surface (outer surface 65A) is a design surface. The outer panel 65 hides the communication hole 63 of the sealing plate portion 27 so that the communication hole 63 cannot be seen from the outside of the front door 20. Therefore, the outer panel 65 compensates for the deterioration of the appearance due to the communication hole 63.

  Further, the space formed between the outer panel 65 and the sealing plate portion 27 by interposing the support column portion 66 allows the outer panel 65 to bend toward the vehicle interior side. Accordingly, when a relatively small load is applied to the front door 20 due to a light impact or the like from the outside of the vehicle, for example, when a shopping cart or the like is lightly applied to the front door 20 from the outside of the vehicle, the support column of the outer panel 65 is supported. A portion other than the portion 66 is once bent toward the inside of the vehicle.

When the shopping cart is moved away from the front door 20 and the load is removed, the outer panel 65 is restored to the state before being bent by its own elastic restoring force.
On the other hand, when a large load is applied to the door main body 21 of the front door 20 from the outside of the vehicle due to a relatively large impact or the like, the outer panel 65 is elastically deformed to be larger than its maximum elastic deformation amount. The load is transmitted to the first door structure 22 and the second door structure 34. At this time, the door main body 21 of the front door 20 exhibits high strength for the following reason.

  (I) The substantially entire first door structure 22 and the substantially entire second door structure 34 are composed of the honeycomb portions 24 and 42 and a pair of sealing plate portions 27 and 28 (46, 47) on both sides thereof. It is comprised by the honeycomb structures 23 and 41.

  When a load due to impact or the like is applied to the front door 20 from the outside of the vehicle and transmitted to the honeycomb structures 23 and 41, the sealing plate portions 27 and 28 (46 and 47) themselves are not so strong against bending stress. The cells 26 and 44 of 24 and 42 are difficult to expand and contract. That is, the honeycomb structures 23 and 41 have a high strength by changing the force applied to the sealing plate portions 27 and 28 (46, 47) to bend them into the force for expanding and contracting the honeycomb portions 24 and 42. Demonstrate. As a result, the honeycomb structures 23 and 41 have high rigidity and are not easily deformed.

(II) The vehicle interior portion 32 of the second door structural body 34 is disposed on the vehicle interior side of the first door structural body 22 and the height of the cells 26 and 44 is substantially increased. thing.
Generally, in the honeycomb structures 23 and 41, the strength tends to increase as the height of the cells 26 and 44 increases, so that the substantial height of the cells 26 and 44 increases as described above. The strength of the door main body 21 is higher than that of the first door component 22 alone.

  (III) Since the two sealing plate portions 28 and 46 are interposed between the honeycomb portion 24 of the first door constituting body 22 and the honeycomb portion 42 of the second door constituting body 34, the sealing plate portion 28, The substantial thickness of 46 is doubled, and the door main body 21 has a larger thickness than the case where one sealing plate portion (only one of the sealing plate portions 28 and 46) is interposed between the honeycomb portions 24 and 42. Strength increases.

  (IV) When the bonding means of the honeycomb structures 23 and 41 is bonding, an adhesive layer is interposed between the bonding portions (between two adjacent sealing plate portions 28 and 46). This adhesive layer also contributes to increasing the strength of the door body 21.

(V) Both reinforcing fibers are mixed in the first door structure 22 and the second door structure 34 made of synthetic resin.
Since the strength is increased as in the above (I) to (V), the relatively large load is reliably received by the first door structure 22 and the second door structure 34.

  In particular, the vehicle interior portion 32 of the second door structure 34 is formed in a square frame shape by the front and rear pillar portions 35 and 36 and the upper and lower bridge portions 37 and 38. Regarding the outer edge portion of the region R in the vicinity of the vehicle interior side of the first door structure 22, the front and rear pillar portions 35 and 36 are located at portions opposite to each other before and after the outer edge portion. That is, the front and rear column portions 35 and 36 are located in the vicinity of the vehicle outer side of the peripheral edge portion of the opening 12 in the body 11 of the automobile. Further, in the region R in the vicinity of the vehicle interior side of the first door structure 22, the upper edge portion, the central portion, and the peripheral portion thereof are formed in an elongated upper and lower bridge portion 37 between the front and rear pillar portions 35 and 36. , 38 are suspended. Therefore, when a load is applied to the door main body 21 as described above, the load is generated in the vehicle interior portion 32 of the second door constituting body 34 by the elongated upper and lower bridge portions 37 and 38 and both the front and rear pillar portions. 35 and 36 are transmitted in this order. This load is received by the highly rigid body 11 located on the vehicle inner side of both the front and rear column portions 35 and 36.

  In addition, in the honeycomb structures 23 and 41, even if some of the many cells 26, 44, 45 are broken, the destructive force hardly reaches the other cells 26, 44, 45. Therefore, even if a part of the first door structure 22 or a part of the second door structure 34 is damaged, other parts of the first door structure 22 or other parts of the second door structure 34 It is unlikely that parts will be destroyed.

  Further, the impact beam 62 formed of fiber reinforced resin and bonded to the vehicle interior side of the first door structure 22 contains long fibers. From this, the impact beam 62 exhibits higher rigidity than the case where the impact beam 62 is formed of a fiber reinforced resin containing fibers having the same length as the fibers in the first door structure 22. Therefore, the impact beam 62 is not easily deformed even when a load is applied from the outside of the vehicle. Even if a large load that damages the first door structure 22 is applied to the front door 20, the impact beam 62 is not damaged and receives the load. It is possible to suppress a phenomenon in which a load hitting the front door 20 tries to enter the vehicle interior side rather than the impact beam 62.

According to the embodiment described in detail above, the following effects can be obtained.
(1) Most of the first door constituting body 22 that is a main part of the front door 20 is formed by a honeycomb structure 23 made of synthetic resin (see FIGS. 5 and 6). Therefore, the weight of the front door 20 can be reduced, the weight of the automobile employing the front door 20 can be reduced, and fuel consumption can be improved.

  (2) In the front door 20, the honeycomb structure 23 is disposed so that the sealing plate portion 27 is positioned on the vehicle outer side and the sealing plate portion 28 is positioned on the vehicle inner side, and the sealing plate portion on the vehicle outer side is disposed. 27 is provided with a communication hole portion 63 for communicating the outside of the sealing plate portion 27 with the cells 26 in the honeycomb portion 24 (see FIGS. 7 to 9). Therefore, by making the communication hole 63 and the internal space 64 of the cell 26 function as a resonance tube (communication hole 63) and a resonance chamber (internal space 64) in the Helmholtz resonance box, respectively, The predetermined frequency component of the propagation sound propagating from the outside to the front door 20 can be reduced. In this way, it is possible to attenuate the propagation sound that propagates from the outside of the vehicle to the front door 20 and tries to enter the vehicle.

Accordingly, it is not necessary to take separate measures such as attaching a soundproofing material or a sound absorbing material to the front door 20 in order to suppress the invasion of the propagation sound into the vehicle.
(3) Since the communication hole 63 is provided for each cell 26, the internal space 64 of each cell 26 can function as a resonance chamber, and a great effect of suppressing the invasion of the propagation sound into the vehicle can be obtained. it can.

  (4) The outer panel 65 is disposed on the vehicle exterior side of the sealing plate portion 27, and the outer surface 65A is used as the design surface of the front door 20 (see FIG. 9). Therefore, the communication panel 63 of the sealing plate 27 is concealed by the outer panel 65 so that the communication hole 63 cannot be seen from the outside of the front door 20, and the appearance of the front door 20 is deteriorated due to the communication hole 63. Can be suppressed.

  (5) By interposing the support pillars 66 at a plurality of locations between the outer panel 65 and the sealing plate part 27, the outer panel 65 and the sealing plate part 27 have a space that allows the outer panel 65 to bend toward the vehicle interior. (See FIG. 9). For this reason, even when a relatively small load is applied to the front door 20 from the outside of the vehicle, the outer panel 65 can be once bent and then restored to its original state by the elastic restoring force of the outer panel 65. The problem that the outer panel 65 remains depressed due to the load can be solved. There is no need to repair the recessed portion of the outer panel 65 separately.

  (6) The outer panel 65 in the above (4) and (5) is formed of a flexible synthetic resin plate. Therefore, when a load is applied to the front door 20 from the outside of the vehicle, only the outer panel 65 can be reliably bent, and when the load is removed, the outer panel 65 once bent can be reliably returned to its original state. In addition, the front door 20 can be further reduced in weight.

Note that the present invention can be embodied in another embodiment described below.
(A) As shown in FIG. 11, a cylindrical portion 67 that protrudes from the inner surface of the sealing plate portion 27 into the internal space 64 of the cell 26 and is open at both ends is provided. The inside may be a communication hole portion 63 that allows the outside of the sealing plate portion 27 to communicate with the internal space 64 of the cell 26. If it does in this way, it will become easy to ensure the length of a resonance pipe (communication hole part 63).

  (B) The communication hole 63 may not necessarily be provided for all the cells 26. If the communication hole portion 63 is provided for at least some of the cells 26 in the honeycomb portion 24, the effect of attenuation of the propagation sound can be obtained.

  (C) In the front door 20, the first door structure 22 and the second door structure 34 may be provided integrally. In short, at least the main part of the front door 20 only needs to be formed of the honeycomb structure 23 made of synthetic resin.

(D) The impact beam 62 may be formed of metal (steel plate) instead of the fiber reinforced resin.
(E) With respect to the pair of sealing plate portions 27 and 28 (46, 47), the relationship between what is integrally formed with the honeycomb portion 24 (42) and what is joined is reversed from the above embodiment. Also good.

  (F) The present invention can be applied to automobile doors such as a rear door and a back door in addition to the automobile front door 20 described above. The present invention can also be applied to an automobile body structure other than the automobile door.

In addition, the technical ideas that can be grasped from the respective embodiments will be described together with their effects.
(A) In the automobile body structure according to any one of claims 1 to 4, the communication hole portion is provided for each cell of all the cells in the honeycomb portion.

  According to said structure, the internal space of each cell can be functioned as a resonance chamber, and the big effect which suppresses the penetration | invasion of the propagation sound into a vehicle can be acquired.

The front view which shows the state which looked at the front door from which the door trim was removed in one Embodiment which actualized this invention from the vehicle inside. The perspective view which shows the state which looked at the front door of FIG. 1 from diagonally forward inside the vehicle. The front view which shows the internal structure of a 1st door structure in the front door of the embodiment. The front view which shows the internal structure of a 2nd door structure in the front door of the embodiment. Sectional drawing which shows the cross-sectional structure along the AA of FIG. Sectional drawing which shows the cross-sectional structure along the BB line of FIG. The fragmentary sectional view which expands and shows the X section in FIG. The fragmentary sectional view which expands and shows the Y section in FIG. The fragmentary sectional view which expands and shows the Z section in FIG. (A)-(C) are the partial front views which show the cell in a honeycomb structure. FIG. 10 is a partial cross-sectional view corresponding to FIG. 9 and showing another embodiment of the communication hole.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 22 ... 1st door structure, 23 ... Honeycomb structure, 24 ... Honeycomb part, 25 ... Partition, 26 ... Cell, 27, 28 ... Sealing plate part, 63 ... Communication hole part, 64 ... Internal space, 65 ... Outer panel , 65A ... outer surface, 66 ... support column part.

Claims (4)

At least a main part is formed of a honeycomb structure made of a synthetic resin, and the honeycomb structure is formed of a plurality of cells that are partitioned by partition walls to form a cylindrical shape, and each cell sandwiching the honeycomb part from both sides. A body structure for an automobile comprising a pair of sealing plate portions for sealing,
The honeycomb structure is disposed so that one of the sealing plate portions is located outside the vehicle and the other is located inside the vehicle, and the sealing plate portion outside the vehicle is disposed outside the sealing plate portion. By providing a communication hole portion that communicates with at least a part of the cells in the honeycomb portion, the communication hole portion functions as a resonance tube for reducing sound propagated to the honeycomb structure from outside the vehicle. And an internal space of the cell is made to function as a resonance chamber for reducing the propagation sound. 2. The vehicle body structure according to claim 1, wherein an outer panel having a design surface as an outer surface of the vehicle is disposed outside the sealing plate portion provided with the communication hole portion. The automobile body structure according to claim 2, wherein support pillar portions are interposed at a plurality of locations between the outer panel and the sealing plate portion having the communication hole portion. The body structure for an automobile according to claim 3, wherein the outer panel is made of a synthetic resin plate having flexibility.

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