JP6366822B2 - Body chassis member - Google Patents

Description

  The present invention relates to a vehicle body chassis member in which a CFRP member is combined with an iron member.

  A front header is connected to the lower surface of the front edge of the roof panel of the automobile to form a closed cross section between the roof panel and the front header, and a cavity reinforcing portion located inside the closed cross section is formed on the front edge of the roof panel. A device that enhances NV performance and collision performance by being integrally formed is known from Patent Document 1 below.

  Further, Patent Document 2 below discloses a technique that suppresses the generation of noise by changing the resonance frequency of the roof panel by fixing the mass addition portion to the lower surface of the roof panel of the automobile with an adhesive.

Japanese Unexamined Patent Publication No. 2013-35295 Japanese Unexamined Patent Publication No. 2006-21696

  By the way, as disclosed in Patent Documents 1 and 2 described above, a vehicle body chassis member such as a roof arch is coupled to a vehicle body panel member such as a roof panel, so that the natural frequency of the vehicle body panel member is reduced to a resonance frequency region. It is possible to suppress the generation of noise by preventing the vehicle body panel member from resonating.

  In this case, in order to sufficiently increase the natural frequency of the vehicle body panel member and prevent resonance, it is necessary to minimize the weight while increasing the rigidity of the vehicle body chassis member coupled to the vehicle body panel member. However, since the rigidity improvement and weight reduction of the vehicle body chassis member are in a trade-off relationship, the vehicle body chassis member is required to be lightweight and have high rigidity.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a vehicle body chassis member that is lightweight, highly rigid, and has a high resonance frequency.

To achieve the above object, according to the present invention, while being configured closed section in the opening of the iron member of the open cross-section by bonding the CFRP member is bonded to the vehicle body panel member viscoelastic adhesive A vehicle body chassis member, wherein the vehicle body chassis member is a roof arch, the vehicle body panel member is a roof panel, and both ends of the roof arch in the vehicle width direction are connected to upper ends of left and right pillars; member of Rukoto bonded by the viscoelastic adhesive to the lower surface of the roof panel vehicle chassis member to the first feature is proposed.

  According to the invention, in addition to the first feature, the CFRP member is formed by impregnating an epoxy resin into a large number of unidirectional fibers oriented in the longitudinal direction, and the iron-based material is made of an epoxy adhesive. A vehicle body chassis member having a second feature of being bonded to the member is proposed.

According to the invention, in addition to the first or second feature, the iron member has a hat-shaped cross section having at least a pair of flange portions, and the CFRP member is bonded to the pair of flange portions. vehicle chassis member to the third feature that the Ru been proposed.

  The roof arch 11 of the embodiment corresponds to the vehicle body chassis member of the present invention, the urethane adhesive 15 of the embodiment corresponds to the viscoelastic adhesive of the present invention, and the roof panel 16 of the embodiment corresponds to the present invention. Corresponding to the vehicle body panel member of the invention, the center pillar 17 of the embodiment corresponds to the pillar of the present invention.

  According to the first feature of the present invention, since the vehicle body chassis member is configured to have a closed cross section by adhering the CFRP member to the open portion of the iron member having an open cross section, the vehicle body chassis member is more completely made than the one made of iron. The resonance frequency can be increased by being light and highly rigid.

Moreover, since the vehicle body chassis member is bonded to the vehicle body panel member with a viscoelastic adhesive, the vehicle body chassis member can effectively prevent the resonance of the vehicle body panel. In particular, the body chassis member is a roof arch, the body panel member is a roof panel, both ends of the roof arch in the vehicle width direction are connected to the upper ends of the left and right pillars, and the CFRP member is viscoelastically bonded to the lower surface of the roof panel. Since it is bonded with the agent, the roof arch can effectively prevent the resonance of the roof panel.

  According to the second feature of the present invention, the CFRP member is constituted by impregnating a large number of unidirectional fibers oriented in the longitudinal direction with an epoxy resin, and is bonded to the iron member with an epoxy adhesive. The natural frequency of the body chassis member can be increased by a CFRP member having a higher specific rigidity than that of iron.

According to the third aspect of the present invention, the iron member has a hat-shaped cross section having at least a pair of flange portions, and the CFRP member is bonded to the pair of flange portions, thereby increasing the height of the iron member. it is possible to increase the rigidity of the body chassis member without, Ru can be increased only vehicle compartment space amount that reduced the height of the vehicle chassis member.

FIG. 1 is a diagram schematically showing a cross-sectional shape of a vehicle body chassis member bonded to a vehicle body panel member. (First embodiment) FIG. 2 is a perspective view of the upper part of the vehicle body of the automobile. (First embodiment) 3 is a cross-sectional view taken along line 3-3 of FIG. (First embodiment) FIG. 4 is a graph showing the relationship between the weight of the vehicle body chassis member and the natural frequency. (First embodiment) FIG. 5 is a graph showing the relationship between the weight and rigidity of the vehicle body chassis member. (First embodiment) FIG. 6 is a graph showing the effect of reducing the booming noise according to this embodiment. (First embodiment) FIG. 7 is a diagram schematically showing a cross-sectional shape of the vehicle body chassis member bonded to the vehicle body panel member. (Second Embodiment) FIG. 8 corresponds to FIG. (Second Embodiment)

11 Car body chassis member (roof arch)
12 Iron member 12c Flange portion 13 CFRP member 14 Epoxy adhesive 15 Urethane adhesive (viscoelastic adhesive)
16 Body panel member (roof panel)
17 Center pillar (pillar)

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

First embodiment

  First, a first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the vehicle body chassis member 11 of the present embodiment is used as a roof arch 11, for example, and has a bottom wall 12a, a pair of side walls 12b, 12b, and a pair of flange portions 12c, 12c. The steel member 12 having a cross section and a CFRP (carbon fiber reinforced resin) member 13 in the form of a flat band plate, and both sides of the CFRP member 13 are epoxy-based on a pair of flange portions 12c, 12c of the iron member 12. A rectangular closed cross section is formed by bonding with the adhesive 14. The CFRP member 13 is obtained by impregnating an epoxy resin into a large number of carbon continuous fibers (UD) oriented parallel to the longitudinal direction and curing the carbon continuous fibers (UD).

  In the vehicle body chassis member 11 having such a structure, a surface of the CFRP member 13 opposite to the surface bonded with the epoxy adhesive 14 is a viscoelastic urethane adhesive 15 and a vehicle body panel member 16 of the automobile. Is adhered to the lower surface of the roof panel 16.

  2 and 3 specifically show the vehicle body chassis member 11 (roof arch 11) schematically shown in FIG. 1, and the iron member 12 has three hat-shaped cross-sections, so that 3 .., Six side walls 12b, and four flange portions 12c. The flat strip-like CFRP member 13 bonded to the iron member 12 with the epoxy adhesive 14 is slightly shorter than the iron member 12, and the iron member 12 protrudes outward in the vehicle width direction from both ends thereof. Both ends of the iron member 12 and both side edges of the roof panel 16 that is the vehicle body panel member 16 are superimposed on the upper ends of the pair of left and right center pillars 17 and 17 of the automobile, and are joined together by welding. The CFRP member 13 is bonded to the lower surface of the roof panel 16 with a urethane adhesive 15.

  The graph of FIG. 4 shows the relationship between the weight and the natural frequency of the vehicle body chassis member 11 (roof arch 11) made of various materials. Is an iron hat-shaped cross section. In any case, when the plate thickness is increased, the weight increases, but the natural frequency hardly increases and the natural frequency of the target height cannot be achieved.

  The symbol ▲ indicates a closed cross section formed by connecting a flat aluminum member to a steel member having a hat-shaped cross section, and the symbol ♦ indicates a closed cross section configured by connecting a flat iron member to a steel member having a hat-shaped cross section. In any case, the natural frequency increases due to the closed cross-section, but the target natural frequency cannot be achieved. The mark * is an open cross section made of CFRP, which is extremely lightweight and increases the natural frequency, but the target natural frequency cannot be achieved.

  On the other hand, the ■ mark is the one in this embodiment in which a flat CFRP member 13 is joined to the iron member 12 having a hat-shaped cross section to form a closed cross-section, and the one having an aluminum hat-shaped cross section (see the ● marks) ), Or with a thin hat-shaped cross-section made of iron (see x), the natural frequency is increased significantly to achieve the target natural frequency. Can do.

  The graph of FIG. 5 shows the relationship between weight and rigidity for the vehicle body chassis member 11 (roof arch 11) made of various materials. If rigidity is important, even if a flat steel member is combined with a hat-shaped iron member to form a closed cross section (see ◆), the same rigidity as this embodiment (see ■) is secured. Although it is made of iron and is heavy, the natural frequency cannot be increased.

That is, when the vibration is input to the connection portion between the upper ends of the center pillars 17 and 17 at both ends of the roof arch 11 which is a long member, and the center portion in the longitudinal direction of the roof arch 11 resonates, the natural frequency of the roof arch 11 is increased. f0 is that the rigidity of the roof arch 11 is k and the mass of the roof arch 11 is m,
f0 = (1 / 2π) · √ (k / m)
Given in. k / m is specific rigidity, and the present embodiment (refer to ■ mark) in which the CFRP member 13 is combined with the iron member 12 has a specific rigidity k / m as compared with that of the entire iron member (refer to the mark ◆). Therefore, the natural frequency f0 of the roof arch 11 can be increased accordingly.

  FIG. 6 shows a vehicle body chassis member 11 (see solid line) made up of a thin plate (t = 1.0 mm) made of iron and a vehicle body chassis member made up of a thick plate (t = 1.8 mm) made of iron. 11 (refer to the chain line) and the relationship between the input frequency and the response level of the vehicle body chassis member 11 (refer to the broken line) of the present embodiment in which the CFRP member 13 is combined with the iron member 12 of t = 1.0 mm. Is shown. According to the present embodiment, even though a thin plate of t = 1.0 mm is used, it is equivalent to the steel open-section vehicle body chassis member 11 (see the chain line) using a thick plate of t = 1.8 mm. It can be seen that the response level is obtained (see the frequency domain enclosed by an ellipse). By reducing the response level of the member (the roof arch 11 in the embodiment), the sound pressure generated by the peripheral components (the roof panel 16 in the embodiment) associated therewith can be reduced.

  As described above, according to the present embodiment, the vehicle body chassis member 11 is configured to have a closed cross section by bonding the CFRP member 13 to the open portion of the iron member 12 having an open cross section. Thus, the vehicle body chassis member 11 is lightweight and highly rigid, so that the resonance frequency can be increased. The CFRP member 13 is constituted by impregnating an epoxy resin into a large number of unidirectional fibers oriented in the longitudinal direction, and is bonded to the iron member 12 with an epoxy adhesive 14. The natural frequency of the vehicle body chassis member 11 can be increased by the CFRP member 13 having high rigidity.

  The iron member 12 has a hat-shaped cross section having at least a pair of flange portions 12c and 12c, and the CFRP member 13 is bonded to the pair of flange portions 12c and 12c, so that the height of the iron member 12 is not increased. The rigidity of the vehicle body chassis member 11 can be increased, and the vehicle compartment space can be increased by the amount by which the height of the vehicle body chassis member 11 is reduced. Moreover, since the vehicle body chassis member 11 is bonded to the vehicle body panel member 16 with the urethane-based adhesive 15 that is a viscoelastic adhesive, the vehicle body chassis member 11 can effectively prevent resonance of the vehicle body panel member 16.

  Further, when the vehicle body chassis member 11 is the roof arch 11 and the vehicle body panel member 16 is the roof panel 16, both ends of the roof arch 11 in the vehicle width direction are connected to the upper ends of the left and right center pillars 17 and 17, and the CFRP member 13 is bonded to the lower surface of the roof panel 16 by the urethane adhesive 15 which is a viscoelastic adhesive, so that the roof arch 11 can effectively prevent resonance of the roof panel 16.

Second embodiment

  Next, a second embodiment of the present invention will be described with reference to FIGS.

  The vehicle body chassis member 11 of the first embodiment has its CFRP member 13 bonded to the lower surface of the vehicle body panel member 16 with a urethane-based adhesive 15, but the vehicle body chassis member 11 of the second embodiment is Is inverted, and the bottom wall 12 a is bonded to the vehicle body panel member 16 with the urethane adhesive 15.

  Also according to the second embodiment, it is possible to achieve the same effect as that of the first embodiment.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the vehicle body chassis member 11 of the present invention is not limited to the roof arch of the embodiment, and the vehicle body panel member 16 of the present invention is not limited to the roof panel of the embodiment.

  Further, the cross section of the iron member 12 is not necessarily a hat-shaped cross section, and may be an open cross section.

  Further, the cross section of the CFRP member 13 is not necessarily flat.

Claims (3)

While being configured closed section in the opening by bonding a CFRP-made member (13) of the steel member of the open cross-section (12), vehicle chassis to be adhered to a vehicle body panel member (16) with viscoelastic adhesive (15) A member (11),
Before Symbol vehicle chassis member (11) is a roof arch, the vehicle body panel member (16) is a roof panel, with both vehicle transverse direction end of the roof arch is connected to the upper end of the left and right pillars (17), The vehicle body chassis member, wherein the CFRP member (13) is bonded to the lower surface of the roof panel with the viscoelastic adhesive (15).   The CFRP member (13) is constructed by impregnating an epoxy resin into a number of unidirectional fibers oriented in the longitudinal direction, and is bonded to the iron member (12) with an epoxy adhesive (14). The vehicle body chassis member according to claim 1, wherein the vehicle body chassis member is a feature.   The iron member (12) has a hat-shaped cross section having at least a pair of flange portions (12c), and the CFRP member (13) is bonded to the pair of flange portions (12c). The vehicle body chassis member according to claim 1 or claim 2.

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