JP6281587B2 - Vehicle panel structure - Google Patents

Description

  The present invention relates to a vehicle panel structure made of fiber reinforced synthetic resin capable of forming a vehicle floor panel and the like, and more particularly to a vehicle panel structure capable of ensuring both rigidity and vibration damping performance.

  Conventionally, fiber reinforced synthetic resin (FRP), in which synthetic fiber is embedded as a reinforcing fiber in the base synthetic resin and has increased strength and rigidity, has been widely used as a material that is lightweight, has high strength and high rigidity. ing. In recent years, carbon fiber reinforced synthetic resin (CFRP) using carbon fibers as reinforcing fibers has attracted attention. CFRP is stronger and more rigid than steel of the same weight, but it is difficult and expensive to process and mass-produce, so it is used in a limited range as a material for aircraft and vehicles with limited production. ing.

  On the other hand, in recent years, fuel efficiency reduction of automobiles has progressed. For reducing fuel consumption, reducing the weight of a vehicle is an effective means. By using a metal member that has been reduced in weight, the weight is reduced while maintaining strength and rigidity. For example, the weight is reduced by using high-tensile steel to thin the member or adopting an aluminum alloy member.

  In order to further reduce the weight, it has been studied to employ high-strength FRP as a panel member such as a floor panel. In general, FRP panels have reinforcing fibers arranged uniformly in a plurality of directions within a panel surface so that rigidity can be secured in any direction. In order to ensure rigidity in a specific direction, as in Patent Document 1, reinforcing fibers may be arranged in a direction of ± 45 ° with respect to the reference direction uniformly within the panel surface.

WO2013191093A1

  By the way, conventionally, it is known that panel members such as a floor panel and a roof panel of a vehicle are likely to vibrate due to an input from a suspension due to road surface unevenness or the like. In particular, the vibration of the floor panel forming the bottom surface of the passenger compartment is easily transmitted to the occupant, which may cause discomfort to the occupant. Therefore, when adopting FRP as a floor panel to reduce the weight of the vehicle, it is not easy to achieve both rigidity ensuring and vibration damping performance.

  An object of the present invention is to provide a vehicle panel structure capable of ensuring both rigidity and vibration damping performance.

  According to a first aspect of the present invention, there is provided a vehicle panel structure including a panel member formed in a rectangular shape using a synthetic resin as a base material and having a peripheral portion fixed to a panel support portion of a vehicle body. A fiber dense portion formed by arranging a plurality of reinforcing fibers in a base material so as to be continuous with a diagonal region of a predetermined width including a pair of diagonal lines in a straight line parallel to the diagonal line and over the entire length of the diagonal region; and A plurality of reinforcing fibers are arranged in the base material so as to be continuous in a plurality of directions in at least a region other than the fiber dense portion of the panel member and linearly extend from the end portion to the end portion of the panel member. A fiber coarse portion, the fiber dense density of the fiber dense portion is set larger than the fiber dense density of the fiber coarse portion, and the stiffness is a value of the ratio of the Young's modulus of the fiber dense portion and the Young's modulus of the coarse fiber portion The ratio is set to 7.4 or higher It is characterized.

  As a result, strength and rigidity can be ensured by arranging reinforcing fibers in parallel to the diagonal lines in the fiber dense portions of a predetermined width parallel to the pair of diagonal lines, and fibers can be formed by the coarse fiber portions formed in the areas other than the fiber dense portions. Since vibration can be absorbed by allowing bending in the rotation direction and bending in the out-of-plane direction around the dense portion, a vehicle panel structure that can achieve both rigidity and vibration damping performance can be provided.

  A vehicle panel structure according to a second aspect of the present invention is the vehicle panel structure having a panel member formed in a rectangular shape using a synthetic resin as a base material and having a peripheral edge portion fixed to the panel support portion of the vehicle body. A panel main body formed by arranging a plurality of reinforcing fibers in a base material so as to be linearly continuous in a plurality of directions and from one end to the other end of the panel member, and a pair of the panel members A pair of band-shaped members made of a synthetic resin each having a diagonal line and having a predetermined width, wherein a plurality of reinforcing fibers are arranged in the synthetic resin so as to be continuous in parallel with the band-shaped member and over the entire length. A pair of belt-shaped members, and the fiber arrangement density of the pair of band-shaped members is set to be larger than the fiber arrangement density of the panel body, and the ratio of the Young's modulus of the band-shaped member to the Young's modulus of the panel body Value rigidity ratio is set to 7.4 or higher It is characterized in that it is.

  Thereby, it is possible to secure the strength and rigidity by arranging the reinforcing fibers at a high fiber density in parallel with the diagonal line on the belt-like member having a predetermined width parallel to the pair of diagonal lines, and by the panel main body portion in which the fibers are arranged at a coarse fiber density. Since the vibration can be absorbed by allowing the bending in the rotation direction and the bending in the out-of-plane direction around the belt-like member, it is possible to provide a vehicle panel structure capable of ensuring both rigidity and vibration damping performance.

  The vehicle panel structure of a third invention is characterized in that, in the first or second invention, the rigidity ratio is set to 74 or less. As a result, the upper limit of the rigidity ratio is set, and the loss coefficient that allows the deflection required for vibration damping can be secured above a certain level, providing a vehicle panel structure that can achieve both rigidity securing and vibration damping performance it can.

  According to the vehicle panel structure of the present invention, it is possible to achieve both rigidity ensuring and vibration damping performance, and it is possible to provide a vehicle panel that is improved over the conventional vehicle panel.

It is a perspective view which shows the floor panel of the vehicle body of the vehicle which concerns on the Example of this invention. It is a top view of the panel member of the panel structure for vehicles. It is a longitudinal cross-sectional view of the state which attached the said panel member to the vehicle body. It is a figure which shows the relationship between the loss coefficient of a panel member, and rigidity. 6 is a plan view of a panel member of a vehicle panel structure according to Embodiment 2. FIG. It is a longitudinal cross-sectional view of the state which attached the panel member of FIG. 5 to the vehicle body.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

As shown in FIG. 1, the floor panel of the vehicle V has, for example, four panel bodies 5a to 5d, and the outer peripheral portions of the panel bodies 5a to 5d are fixed to the panel support portion of the vehicle body.
The vehicle width direction inner end portions of these panel bodies 5a to 5d are fixed to the panel support portion 3a of the floor tunnel 30, and the vehicle width direction outer end portions of the panel bodies 5a to 5d are fixed to the panel support portion 3b of the side sill 31. Yes. The front end portions of the front panel members 5a and 5b are fixed to the panel support portion 3c of the dash lower panel 32, and the rear end portion is fixed to the panel support portion (not shown) of the cross member 33.

The front end portions of the rear-row panel bodies 5c and 5d are fixed to the panel support portion 3d of the cross member 33, and the rear end portions are fixed to a panel support portion (not shown) of a cross member not shown.
The arrow F direction indicates the front, the arrow L direction indicates the left side, and the arrow U direction indicates the upper side.

As shown in FIGS. 2 and 3, a vehicle panel structure 1 (hereinafter referred to as a panel structure 1) described below is applicable to the panel bodies 5a to 5d shown in FIG.
The panel member 2 constituting the panel structure 1 is made of FRP in which a plurality of reinforcing fibers 4 are embedded in a synthetic resin base material (for example, thermosetting epoxy-based synthetic resin), and the length of one side is, for example, 1000 to 1200 mm. It is formed in a rectangular shape with a thickness of 2 to 3 mm, for example. As the reinforcing fiber 4, for example, carbon fiber or aramid fiber can be employed.

  As shown in FIG. 2, the panel member 2 has a plurality of linearly continuous reinforcing fibers 4 arranged from end to end and are embedded in a synthetic resin base material. The diameter of the reinforcing fiber 4 is, for example, 7 to 10 μm. The reinforcing fiber 4 has a high strength with respect to a tensile force and bears the strength and rigidity of the panel member 2. The synthetic resin base material has viscoelasticity and absorbs vibration energy through the bending of the panel member 2 in the out-of-plane direction to attenuate the vibration.

  As shown in FIG. 2 and FIG. 3, the panel member 2 has a predetermined first fiber arrangement density (for example, the proportion of the reinforcing fibers 4 in the unit cross-sectional area is 10 to 30%) in the base material. The fiber coarse portions 6a to 6d included and the second fiber arrangement density larger than the first fiber arrangement density of the fiber coarse portions 6a to 6d (for example, the proportion of the reinforcing fibers 4 in the unit cross-sectional area is 50 to 60%). The fiber 4 has fiber dense portions 7a and 7b included in the base material.

  The dense fiber portions 7 a and 7 b are provided in a diagonal region having a predetermined width (for example, 20 to 30 mm width) including a pair of diagonal lines of the panel member 2. In the fiber dense portions 7a and 7b, the reinforcing fibers 4 are provided so as to continue linearly in parallel to the corresponding diagonal line over the entire length of the diagonal line region. In the fiber dense portion 7a, the reinforcing fibers 4 are arranged in the second fiber arrangement density in a direction parallel to one diagonal line of the panel member 2, and in the fiber dense portion 7b, the second fiber arrangement density is arranged in a direction parallel to the other diagonal line. Is arranged in.

  Regions other than at least the diagonal region of the panel member 2 are constituted by fiber coarse portions 6a to 6d, and these fiber coarse portions 6a to 6d are linearly continuous from the end to the end of the panel member 2. A plurality of reinforcing fibers 4 are arranged in parallel with a pair of diagonal directions and intersect each other and are arranged at a first fiber arrangement density. In the fiber coarse portions 6a to 6d, the reinforcing fibers 4 in three or more different directions may be arranged at the first fiber arrangement density in a pseudo isotropic manner.

  The panel member 2 is made by injecting a synthetic resin base material into a mold in which a plurality of reinforcing fibers 4 are arranged so as to form, for example, the fiber coarse portions 6a to 6d and the fiber dense portions 7a and 7b, and applying temperature and pressure. Molded. A layer in which a plurality of reinforcing fibers 4 are arranged in a direction along one of a pair of diagonal lines so as to form the fiber coarse portions 6a to 6d and the fiber dense portions 7a and 7b, and the fiber coarse portions 6a to 6d and the fibers. The panel member 2 may be formed by alternately laminating a plurality of layers in which a plurality of reinforcing fibers 4 are arranged in the direction along the other diagonal line so as to form the dense portions 7a and 7b.

Since the panel member 2 is provided with the fiber dense portions 7a and 7b exhibiting strength and rigidity in a diagonal region having a predetermined width along a pair of diagonal lines, the strength and rigidity of the panel member 2 can be secured. Moreover, since the fiber rough portions 6a to 6d that can exhibit the vibration damping performance by the viscoelasticity of the synthetic resin base material are provided at least in a region other than the diagonal region, the vibration damping performance can be ensured.
That is, the fiber dense portions 7a and 7b of the panel member 2 are not easily deformed due to high strength and rigidity in the in-plane direction and the out-of-plane direction, and the fiber dense portions 7a and 7b are in-plane because they are along a pair of diagonal lines. It is difficult to deform with respect to the shearing force, and the vibration can be attenuated by allowing the fiber coarse portions 6a to 6d to be twisted around one of a pair of diagonal lines or to bend in the out-of-plane direction. .

  FIG. 4 shows the relationship between the loss factor and rigidity of the panel member 2 having a thickness of 2 mm. The loss factor is an index indicating how much energy is absorbed when the material is deformed, and the greater the loss factor, the higher the vibration damping performance. Note that the thickness of the panel member 2 is not limited to this and is appropriately set according to the application site and the like, but the relationship between the loss coefficient and the rigidity shows the same tendency as in FIG. 4 even at different thicknesses.

  In FIG. 4, the solid line is a curve connecting points where existing steel plate panel members, synthetic resin panel members, and the like are plotted with squares, and the rigidity and loss coefficient are unique to the material. The points plotted with ▲ indicate the Young's modulus of the fiber dense portions 7a and 7b of the CFRP panel member 2 and the Young's modulus of the coarse fiber portions 6a to 6d by the present inventor in order to achieve both rigidity securing and vibration damping performance. The examination result which changed and changed the ratio value (rigidity ratio) variously is shown. This simulation is carried out by keeping the Young's modulus of the coarse fiber portions 6a to 6d constant and changing the Young's modulus of the dense fiber portions 7a and 7b. The Young's modulus of the fiber dense portions 7a and 7b can be changed by changing the second fiber arrangement density, changing the diameter of the reinforcing fibers 4, or the like.

  The solid line has a relationship that the loss factor decreases as the stiffness increases, and the stiffness decreases as the loss factor increases. Also in the panel member 2 made of CFRP, when the rigidity is increased (the rigidity ratio is increased), the loss coefficient is decreased, and the same tendency as the solid line is shown. However, the panel member 2 is located on the upper right side of the solid line. If the rigidity is the same as that of the existing panel member, the loss coefficient is improved, and if the loss coefficient is the same, the rigidity is improved.

  Here, the rigidity and loss factor of the panel member 2 are appropriately determined depending on the location, size, structure, etc. of the vehicle body in which the panel member 2 is used. In this embodiment, for example, the rigidity ratio is set to 7.4 or more in order to ensure the rigidity required for the panel bodies 5a to 5d of the floor panel. Further, in order to ensure the required vibration damping performance, the rigidity ratio is set to 74 or less.

Next, the operation and effect of the vehicle panel structure 1 will be described.
As described above, the reinforcing fibers can be arranged in parallel to the diagonal lines in the fiber dense portions having a predetermined width parallel to the pair of diagonal lines to ensure the strength and rigidity, and the fiber coarseness formed in the region other than the fiber dense portions. Since the vibration can be absorbed by allowing the portion to bend in the rotation direction around the fiber dense portion and the deflection in the out-of-plane direction, it is possible to provide a vehicle panel structure capable of ensuring both rigidity and vibration damping performance.
Further, the specific gravity of the panel member 2 of the vehicle panel structure 1 is about 1.5, and the specific gravity of the existing steel panel member, for example, is 7.85, so that the weight can be reduced.

  Further, in the panel member 2, fiber dense portions 7a and 7b in which the reinforcing fibers 4 are arranged at the second fiber arrangement density are formed in the diagonal region having a predetermined width, and the reinforcing fibers 4 are the first fibers in the other regions. Since the fiber coarse portions 6a to 6d arranged at the arrangement density are formed, the total amount of the reinforcing fibers 4 used in the panel member 2 can be reduced, and the manufacturing cost can be reduced.

Next, a vehicle panel structure 11 (hereinafter referred to as a panel structure 11) according to a second embodiment will be described with reference to FIGS.
The panel member 12 constituting the panel structure 11 includes a rectangular panel main body 18 and a pair of band-shaped members 19 and 20 fixed to both upper and lower surfaces of the panel main body 18. The panel structure 11 can be applied to the panel bodies 5a to 5d in FIG.

  As shown in FIGS. 5 and 6, the panel main body 18 is made of FRP in which a plurality of reinforcing fibers 14 are embedded in a base material (for example, thermosetting epoxy-based synthetic resin), and one side is, for example, 1000 to 1200 mm thick. Is formed in a panel shape of 2 to 3 mm, for example. The panel main body 18 includes a plurality of reinforcing fibers 14 at a predetermined first fiber arrangement density (for example, the proportion of the reinforcing fibers 14 in the unit cross-sectional area is 10 to 30%), and constitutes a coarse fiber portion. The directions in which the reinforcing fibers 14 extend are two directions along a pair of diagonal lines of the rectangular panel body 18, but may be a plurality of directions of three or more in a pseudo isotropic manner.

  In the panel body 18, a plurality of reinforcing fibers 14 that are linearly continuous from one end to the other are arranged, and are embedded in the synthetic resin base material. As the reinforcing fiber 14, for example, carbon fiber or aramid fiber can be employed, and the diameter thereof is, for example, 7 to 10 μm.

  The band-shaped members 19 and 20 are made of FRP in which a plurality of reinforcing fibers 14 are embedded in a synthetic resin base material (for example, a thermosetting epoxy-based synthetic resin), and have a width of, for example, 20 to 30 mm, a thickness of, for example, 2-3 mm, and a long length. The length is the same as the diagonal line of the panel body 18 and both ends thereof are formed so as to match the corner shape of the panel body 18. The band-shaped members 19 and 20 are included at a second fiber arrangement density in which the reinforcing fibers 14 are higher than the first fiber arrangement density (for example, the proportion of the reinforcing fibers 4 in the unit cross-sectional area is 50 to 60%). Is configured.

The strip-shaped members 19 and 20 are arranged with a plurality of reinforcing fibers 14 extending so as to be continuous in a straight line parallel to the diagonal along the entire diagonal length of the panel body 18 and are embedded in the synthetic resin base material. It has become. As the reinforcing fiber 14, for example, carbon fiber or aramid fiber can be employed, and the diameter thereof is, for example, 7 to 10 μm.
The belt-like member 19 is disposed on the upper surface of the panel main body 18 in parallel with one diagonal line, and is fixed to the panel main body 18 by bonding. The belt-like member 20 is disposed on the lower surface of the panel main body 18 in parallel with the other diagonal line, and is fixed to the panel main body 18 by bonding.

  Since the panel member 12 has the belt-like members 19 and 20 constituting the fiber dense portion 17 intersecting along a pair of diagonal lines, it is possible to ensure the strength and rigidity in a pair of diagonal directions in which the reinforcing fibers 14 extend. Moreover, since the panel member 12 has the panel main body part 18 which comprises the fiber coarse part 16, the bending of the panel main body part 18 is permitted by the viscoelasticity of the base material, and vibration energy can be absorbed to attenuate the vibration. it can. Accordingly, the panel member 12 has the characteristics shown in FIG. 4 like the panel member 2 of the first embodiment. For example, the rigidity ratio is 7.4 in order to ensure the rigidity required for the panel bodies 5a to 5d of the floor panel. Set as above. Further, in order to ensure the required vibration damping performance, the rigidity ratio is set to 74 or less.

Next, functions and effects of the vehicle panel structure 11 will be described.
A belt-shaped member having a predetermined width parallel to a pair of diagonal lines can be provided with a high fiber density in parallel with the diagonal lines to ensure strength and rigidity, and the band-shaped member is formed by a panel body portion in which the fibers are disposed at a coarse fiber density. Since the vibration can be absorbed by allowing the bending in the rotation direction and the bending in the out-of-plane direction as the center, it is possible to provide a vehicle panel structure capable of ensuring both rigidity and vibration damping performance.

  Since the panel main body 18 and the strip-shaped members 19 and 20 are separately manufactured and then fixed to form the panel member 12, the panel member 12 can be easily manufactured and the manufacturing cost can be reduced. Further, the specific gravity of the panel member 12 is about 1.5, and the specific gravity of an existing panel member, for example, a steel plate panel member, is 7.85, so that the weight can be reduced.

  Furthermore, since the band-like members 19 and 20 constituting the fiber dense portion 17 along a pair of diagonal lines necessary for securing the rigidity of the panel member 12 are fixed to the panel body portion 18 constituting the fiber coarse portion 16, The total amount of the reinforcing fibers 14 used for the panel member 12 can be reduced, and the manufacturing cost can be reduced.

Next, an example in which the first and second embodiments are partially changed will be described.
1) In Example 1, in addition to the fiber dense portion 7a, a fiber dense portion having the same width is formed in parallel on both sides of the fiber dense portion 7a, and the fiber dense portion having the same width is formed on both sides of the fiber dense portion 7b. May be formed in parallel.
2) In Example 2, in addition to the belt-like member 19, a belt-like member having the same width as that on both sides of the belt-like member 19 and a belt-like member having the same width on both sides of the belt-like member 20 may be provided. Good.

3) In the second embodiment, the belt-like members 19 and 20 may be disposed on the lower surface of the panel body 18. In this case, you may form in the overlapping shape which closely_contact | adhered both in the cross | intersection part of the strip | belt-shaped members 19 and 20. FIG.
4) In the first and second embodiments, the vehicle panel structure of the present invention is applied to a floor panel. However, the present invention is not limited to this, and is also applied to a panel-like member in another part of the vehicle. Is possible.

5) In addition, those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. is there.

V Vehicle 1, 11 Vehicle panel structure 2, 12 Panel member 3 a to 3 c Panel support portion 4, 14 Reinforcing fiber 5 a to 5 d Panel body 6 a to 6 d Fiber coarse portion 7 a, 7 b Fiber dense portion 18 Panel body portion 19, 20 Band shape Element

Claims (3)

In a vehicle panel structure having a panel member that is formed in a rectangular shape using a synthetic resin as a base material and a peripheral portion is fixed to a panel support portion of a vehicle body,
A fiber formed by arranging a plurality of reinforcing fibers in a base material so as to be linearly continuous with a diagonal region of a predetermined width including a pair of diagonal lines of the panel member, parallel to the diagonal line and over the entire length of the diagonal region. Dense part,
A plurality of reinforcing fibers are arranged in the base material so as to be continuous in a plurality of directions at least in the region other than the fiber dense portion of the panel member and linearly from the end portion to the end portion of the panel member. Comprising a coarse fiber portion,
The fiber arrangement density of the fiber dense part is set larger than the fiber arrangement density of the fiber coarse part,
A vehicle panel structure, characterized in that a stiffness ratio, which is a value of a ratio between a Young's modulus of the dense fiber portion and a Young's modulus of the coarse fiber portion, is set to 7.4 or more. In a vehicle panel structure having a panel member that is formed in a rectangular shape using a synthetic resin as a base material and a peripheral portion is fixed to a panel support portion of a vehicle body,
The panel member is
A panel main body formed by arranging a plurality of reinforcing fibers in the base material so as to be linearly continuous from one end to the other end of the panel member in a plurality of directions,
A pair of band-shaped members made of synthetic resin having a predetermined width, each including a pair of diagonal lines of the panel member, and a plurality of the band members in the synthetic resin so as to be linearly continuous in parallel with the band-shaped member over the entire length. A pair of belt-like members formed by arranging the reinforcing fibers of
The fiber arrangement density of the pair of belt-shaped members is set to be larger than the fiber arrangement density of the panel main body,
A vehicle panel structure, wherein a rigidity ratio, which is a value of a ratio between a Young's modulus of the belt-shaped member and a Young's modulus of the panel main body, is set to 7.4 or more.   The vehicle panel structure according to claim 1, wherein the rigidity ratio is set to 74 or less.