JP2019182168A - Center pillar inner and center pillar - Google Patents

Abstract

To achieve both light weight and impact resistance of a center pillar while restricting a cost increase.SOLUTION: A center pillar inner 20 comprises: an inner member 21 having: an opening 21a serving as a mounting part for a seat belt retractor; and a side sill mounting part 21b serving as a mounting part for a side sill 30; and a CFRP member 22 joined to a surface of the inner member 21. The CFRP member 22 is provided at least between the opening 21a and the side sill mounting part 21b.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an automobile center pillar inner.

  FIG. 1 is a diagram showing a vehicle body structure of a general automobile, and members such as a center pillar, a roof side rail, and a side sill are provided in a portion corresponding to a vehicle side surface. The center pillar has an upper end joined to the roof side rail and a lower end joined to the side sill. Center pillars are required to have impact resistance to protect passengers in the event of a side collision of a car, and technological development to improve impact resistance has been ongoing.

  Patent Document 1 discloses that among the outer member and the inner member constituting the center pillar, the inner member is formed of CFRP (carbon fiber reinforced resin). Patent Document 2 discloses that the outer member is made of aluminum and the inner member is made of CFRP. Patent Document 3 discloses that a reinforcing member made of CFRP is filled between an outer member and an inner member.

JP 2013-212731 A International Publication No. 2015/025572 JP, 2014-080183, A

  When CFRP is applied as the inner member of the center pillar as in Patent Documents 1 and 2, the impact resistance required for the center pillar is not ensured because it is lighter than metal but has low elongation. Further, it is not preferable to use the inner member as it is as CFRP because the increase in cost is remarkable as compared with the case of using metal.

  In recent years, weight reduction of vehicles has been regarded as important for improving fuel efficiency. However, if a reinforcing member is filled between an outer member and an inner member as in Patent Document 3, the size of the reinforcing member increases. Inevitably increases the weight. In the case of Patent Document 3, it is conceivable to reduce the thickness of the inner member, for example, in order to reduce the weight of the vehicle, but this cannot sufficiently ensure the impact resistance of the center pillar.

  This invention is made | formed in view of the said situation, and it aims at making the weight reduction of a center pillar and impact resistance compatible, suppressing the increase in cost.

  The present invention that solves the above-described problems includes an inner member having an opening that serves as a seat belt retractor mounting portion, a side sill mounting portion that serves as a side sill mounting portion, and a CFRP member joined to the surface of the inner member. The CFRP member is provided at least between the opening and the side sill attaching portion.

  According to another aspect of the present invention, there is provided a center pillar, comprising a center pillar outer and the center pillar inner, wherein the center pillar outer and the center pillar inner are joined to each other at a flange portion. It is a feature.

  According to the present invention, it is possible to achieve both weight reduction and impact resistance of the center pillar while suppressing an increase in cost.

It is a figure which shows the vehicle body structure of a common motor vehicle. It is a figure which shows schematic structure of the center pillar which concerns on the 1st Embodiment of this invention. It is an exploded view of the center pillar which concerns on the 1st Embodiment of this invention. It is a figure which shows the inner member of the center pillar which concerns on the 1st Embodiment of this invention. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. It is a figure which shows schematic structure of the center pillar which concerns on the 2nd Embodiment of this invention. It is a figure equivalent to the AA cross section in FIG. 2 of the center pillar which concerns on the 2nd Embodiment of this invention. It is a figure equivalent to the BB cross section in FIG. 2 of the center pillar which concerns on the 2nd Embodiment of this invention. It is a figure which shows schematic structure of the center pillar which concerns on the 3rd Embodiment of this invention. It is a figure which shows schematic structure of the center pillar which concerns on the 4th Embodiment of this invention. It is a figure which shows the analysis model of the side collision simulation in an Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

<First Embodiment>
As shown in FIG. 2, the center pillar 1 of the first embodiment includes a center pillar outer 10 and a center pillar inner 20. The center pillar outer 10 is a member made of, for example, a cold rolled steel plate or a hot stamped steel plate. As shown in FIGS. 2 and 3, the center pillar inner 20 includes an inner member 21 joined to the center pillar outer 10 and a CFRP member 22 joined to the inner member 21. The inner member 21 is a member made of, for example, a hot rolled steel plate. In addition, the raw material which comprises the center pillar outer 10 and the inner member 21 will not be specifically limited if it is a metal, For example, an aluminum alloy etc. may be sufficient. The CFRP member 22 is a member made of a carbon fiber reinforced resin in which a predetermined matrix resin contains carbon fibers as a reinforced fiber resin. The matrix resin and carbon fiber constituting the CFRP member will be described in detail later.

  As shown in FIG. 4, the inner member 21 which is a component of the center pillar inner 20 has an opening 21 a provided so that a seat belt retractor (winding device) can be attached, and a side sill 30 can be attached. The side sill attaching part 21b provided in the. The side sill attachment portion 21 b corresponds to a portion of the inner member 21 that is covered with the side sill 30 when the inner member 21 and the side sill 30 are joined. Therefore, the opening 21 a corresponds to a seat belt retractor mounting location, and the side sill mounting portion 21 b corresponds to a side sill mounting location. Although the side sill attaching part 21b of 1st Embodiment is formed in planar shape so that the surface contact with the side sill 30 is formed, the shape of the side sill attaching part 21b is not specifically limited.

  As shown in FIGS. 2 to 6, the shape of the opening 21a of the inner member 21 from slightly below to the upper end 21c is a hat shape in a cross-sectional view perpendicular to the height direction, and the flange portion 21d is formed. Has been. The center pillar 1 is manufactured by joining the flange portion 21d of the inner member 21 and the flange portion 10a of the center pillar outer 10 having a hat shape like the inner member 21 to each other by spot welding, for example.

  In the first embodiment, the CFRP member 22 is provided on the entire surface of the inner member 21. The shape of the CFRP member 22 is the same as the shape between the side sill attachment portion 21b and the upper end portion 21c of the inner member 21, and the CFRP member 22 covers, for example, the opening 21a of the inner member 21. A hole 22a (FIG. 3) having the same shape as the opening 21a is provided. The thickness of the CFRP member 22 is appropriately changed according to the required impact resistance and weight limit, but is preferably 1 to 4 mm, for example.

  The CFRP member 22 is joined to the inner surface of the inner member 21. The joining method of the inner member 21 and the CFRP member 22 is not particularly limited, but is joined using, for example, an adhesive. Further, if the matrix resin of the CFRP member 22 is a thermoplastic resin, the CFRP member 22 may be joined by being heated and thermally bonded to the inner member 21. Therefore, for example, the center pillar inner 20 is manufactured by bonding the CFRP member 22 to the inner surface of the inner member 21 using an adhesive after joining the inner member 21 and the center pillar outer 10. Looking at the cross section of the center pillar inner 20 in this case, it can be confirmed that an adhesive is present between the inner member 21 and the CFRP member 22.

  Further, for example, the center pillar inner 20 is formed by bonding a CFRP member 22 whose shape is adjusted so that the blank opening 21a is not covered to the blank of the inner member 21 in which the opening 21a is formed. It is manufactured by joining by press forming after that. When the inner member 21 and the CFRP member 22 are joined before the center pillar outer 10 and the center pillar inner 20 are joined, the spot welding spot between the center pillar outer 10 and the center pillar inner 20 is covered with the CFRP member 22. In order to prevent a broken state, the CFRP member 22 is provided with a hole (not shown) in advance at a position corresponding to the spot welding spot position.

  If the matrix resin of the CFRP member 22 is a thermoplastic resin, the bonding between the inner member 21 and the CFRP member 22 is compared with the case where a thermosetting resin is used by adhesive or heat fusion as described above. And it can join more firmly. Thereby, even if an impact is applied to the center pillar inner 20 in the case of a side collision, the CFRP member 22 follows the deformation of the inner member 21, so that the reinforcing effect is increased. In addition, CFRP using a thermoplastic resin has a larger elongation than CFRP using a thermosetting resin (about 1-2%). Therefore, if the thermoplastic resin is applied to the CFRP member 22, the work amount due to the pulling of the CFRP member 22 at the time of a side collision becomes larger than that in the case of using the thermosetting resin, so that the impact resistance is further improved. A specific method for joining the inner member 21 and the CFRP member 22 will be described later.

  The center pillar inner 20 of the first embodiment and the center pillar 1 including the center pillar inner 20 are configured as described above. At the time of a side collision, a compressive load is applied to the center pillar outer 10 and a tensile load is applied to the center pillar inner 20, but the center pillar inner 20 of the first embodiment is provided with a CFRP member 22. Thus, the tensile load generated at the time of a side collision can be received by the CFRP member 22. Since CFRP is excellent in specific strength, it is possible to improve impact resistance while achieving weight reduction without increasing the strength of the inner member 21. Along with this, it becomes possible to use a metal such as a mild steel plate having high ductility for the inner member 21, and it is possible to suppress breakage of the center pillar inner 20 at the time of a side collision.

  Thus, if the center pillar inner 20 is configured by joining the CFRP member 22 to the inner member 21, the impact resistance of the center pillar 1 can be improved. In other words, by using the center pillar inner 20 of the first embodiment, sufficient impact resistance can be ensured even if the thickness of the inner member 21 is reduced for the purpose of reducing the weight of the vehicle. That is, both the weight reduction and impact resistance of the center pillar 1 can be achieved. Further, in the center pillar inner 20 as in the first embodiment, an increase in cost can be suppressed as compared with the case where the entire inner member 21 is configured by CFRP.

  Furthermore, if the amount of the CFRP member 22 is such that it can be used for the center pillar inner 20, when the center pillar inner 20 is reused as scrap, the inner member 21 and the CFRP member 22 may be dissolved as they are without being separated. Impurities do not increase excessively. Therefore, the center pillar inner 20 in which the CFRP member 22 is joined to the inner member 21 is also excellent in recyclability.

<Second Embodiment>
As shown in FIGS. 7 to 9, the CFRP member 22 of the second embodiment is not provided on the entire surface of the inner member 21 as in the first embodiment, and the opening 21 a of the inner member 21 and the side sill are not provided. The region between the mounting portion 21 b and the entire flange portion 21 d of the inner member 21 are provided. In the following description, a region between the opening 21a of the inner member 21 and the side sill attaching portion 21b is referred to as a “lower portion 21e” of the inner member 21.

  At the time of a side collision, large plastic strain is likely to occur in the lower portion 21e of the inner member 21 and the flange portion 21d on the side of the opening 21a, but the center pillar inner 20 of the second embodiment has a lower portion 21e and a flange. Since the CFRP member 22 is provided on the entire portion 21d, it is possible to effectively reinforce a portion that is easily deformed at the time of a side collision. That is, the flange portion 21 d is a joint portion with the center pillar outer 10, and is a portion that is easily subjected to an impact input to the center pillar outer 10. By providing the CFRP member 22 in the flange portion 21d, it is possible to suppress deformation of the flange portion 21d according to the deformation of the center pillar outer 10 due to a side collision. Thereby, the impact resistance of the center pillar inner 20 can be improved effectively. Therefore, if the center pillar inner 20 of the second embodiment is used, the amount of use of the CFRP member 22 is reduced and the cost is reduced as compared with the case where the CFRP member 22 is provided on the entire surface of the inner member 21 as in the first embodiment. Sufficient impact resistance can be ensured while suppressing and reducing the weight.

<Third Embodiment>
As shown in FIG. 10, the CFRP member 22 of the third embodiment is provided on the lower portion 21e of the inner member 21 and the flange portion 21d 'on the side of the opening 21a. As described above, the plastic strain of the inner member 21 that occurs at the time of a side collision is likely to increase between the lower portion 21e and the flange portion 21d 'on the side of the opening portion 21a, so that the CFRP member 22 is opened as in the second embodiment. Even if the flange 21d ′ positioned above the portion 21a is not provided, if the CFRP member 22 is provided on the flange 21d ′ on the side of the opening 21a, the inner member 21 is effectively reinforced. be able to. Therefore, if the center pillar inner 20 of the third embodiment is used, the usage amount of the CFRP member 22 is further reduced with respect to the center pillar inner 20 of the second embodiment to reduce the cost and reduce the weight. Sufficient impact resistance can be ensured.

<Fourth Embodiment>
As shown in FIG. 11, the CFRP member 22 of the fourth embodiment is provided only at the lower portion 21 e of the inner member 21. As for the plastic strain of the inner member 21 generated at the time of a side collision, the lower portion 21e between the side sill attachment portion 21b and the opening portion 21a in the inner member 21 tends to be significantly large. Therefore, even when the CFRP member 22 is provided only in the lower portion 21e as in the fourth embodiment, the inner member 21 can be effectively reinforced. Therefore, if the center pillar inner 20 of the fourth embodiment is used, sufficient impact resistance can be ensured while further reducing the weight with respect to the center pillar inner 20 of the third embodiment. Efficiency is even better.

  As described in the above first to fourth embodiments, there are a plurality of embodiments for the joint portion of the CFRP member 22 to the inner member 21, but weight reduction and impact resistance while suppressing an increase in cost. From the viewpoint of achieving both of these, the CFRP member 22 needs to be provided at least in the lower portion 21e of the inner member 21 where the plastic strain is greatest at the time of a side collision.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this example. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  For example, in the first to fourth embodiments, the CFRP member 22 is joined to the inner surface of the inner member 21. However, the CFRP member 22 may be joined to the outer surface of the inner member 21. . That is, the CFRP member 22 may be provided between the center pillar outer 10 and the inner member 21. In this case, the center pillar inner 20 is manufactured by performing press molding in a state where the blank of the inner member 21 and the CFRP member 22 are bonded in advance. Thereafter, the center pillar outer 10 and the center pillar inner 20 are joined by, for example, spot welding to form the center pillar 1. When spot welding is performed, a hole (not shown) is provided in advance in the CFRP member 22 at a position corresponding to the spot welding spot position so that the CFRP member 22 does not cover the spot welding spot of the inner member 21. It is done.

<Types of CFRP members>
The CFRP member that can be affixed to the inner member in each embodiment means a carbon fiber reinforced resin member made of a matrix resin and a composite carbon fiber material contained in the matrix resin. As the carbon fiber, for example, a PAN-based or pitch-based one can be used. By using the carbon fiber, the strength with respect to weight can be improved efficiently.

  As the matrix resin used for the CFRP member, either a thermosetting resin or a thermoplastic resin can be used. Examples of the thermosetting resin include epoxy resins, unsaturated polyester resins, and vinyl ester resins. As thermoplastic resins, polyolefins (polyethylene, polypropylene, etc.) and acid-modified products thereof, polyamide resins such as nylon 6 and nylon 66, thermoplastic aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate, polyethersulfone And polyphenylene ether and modified products thereof, polyarylate, polyetherketone, polyetheretherketone, polyetherketoneketone, styrene resins such as vinyl chloride and polystyrene, and phenoxy resin. The matrix resin may be formed of a plurality of types of resin materials.

  Considering application to a metal member, it is preferable to use a thermoplastic resin as a matrix resin from the viewpoint of workability and productivity. Furthermore, the density of the reinforcing fiber material can be increased by using a phenoxy resin as the matrix resin. Moreover, since the phenoxy resin has a molecular structure very similar to that of an epoxy resin that is a thermosetting resin, the phenoxy resin has a heat resistance comparable to that of an epoxy resin. Moreover, application to a high temperature environment is also possible by further adding a curing component. In the case of adding a curable component, the addition amount may be appropriately determined in consideration of the impregnation property to the reinforcing fiber material, the brittleness of the FRP member, the tact time, the workability, and the like.

<Adhesive resin layer>
When the reinforcing member is formed of a CFRP member or the like, an adhesive resin layer is provided between the CFRP member and the metal member (in the above embodiment, the inner member 21), and the CFRP member and the metal member are joined by the adhesive resin layer. May be.

  The kind of adhesive resin composition which forms an adhesive resin layer is not specifically limited. For example, the adhesive resin composition may be either a thermosetting resin or a thermoplastic resin. The kind of thermosetting resin and thermoplastic resin is not particularly limited. Examples of thermoplastic resins include polyolefins and acid-modified products thereof, polystyrene, polymethyl methacrylate, AS resin, ABS resin, thermoplastic aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate, polyimide, polyamide, polyamide Use one or more selected from imide, polyetherimide, polyethersulfone, polyphenylene ether and modified products thereof, polyphenylene sulfide, polyoxymethylene, polyarylate, polyetherketone, polyetheretherketone, and polyetherketoneketone can do. Moreover, as a thermosetting resin, 1 or more types chosen from an epoxy resin, a vinyl ester resin, a phenol resin, and a urethane resin can be used, for example.

  The adhesive resin composition can be appropriately selected according to the characteristics of the matrix resin constituting the CFRP member, the characteristics of the reinforcing member, or the characteristics of the metal member. For example, the adhesiveness is improved by using a resin having a polar functional group or a resin subjected to acid modification as the adhesive resin layer.

  Thus, the adhesion between the CFRP member and the metal member can be improved by adhering the CFRP member to the metal member using the above-described adhesive resin layer. Then, the deformation followability of the CFRP member when a load is input to the metal member can be improved. In this case, the effect of the CFRP member on the deformed body of the metal member can be more reliably exhibited.

  In addition, the form of the adhesive resin composition used for forming the adhesive resin layer can be, for example, a liquid such as powder or varnish, or a solid such as a film.

  Moreover, you may mix | blend a crosslinking curable resin and a crosslinking agent with an adhesive resin composition, and may form a crosslinkable adhesive resin composition. Thereby, since the heat resistance of the adhesive resin composition is improved, application under a high temperature environment becomes possible. As the cross-linking curable resin, for example, a bifunctional or higher functional epoxy resin or a crystalline epoxy resin can be used. Moreover, an amine, an acid anhydride, etc. can be used as a crosslinking agent. Moreover, various additives, such as various rubber | gum, an inorganic filler, a solvent, may be mix | blended with the adhesive resin composition in the range which does not impair the adhesiveness and physical property.

  The compounding of the CFRP member into the metal member can be realized by various methods. For example, it can be obtained by bonding a CFRP prepreg as a CFRP member or a CFRP molding prepreg, which is a CFRP member, and a metal member with the above-described adhesive resin composition and solidifying (or curing) the adhesive resin composition. . In this case, for example, the CFRP member and the metal member can be combined by performing thermocompression bonding.

  The above-mentioned adhesion of the CFRP or CFRP molding prepreg to the metal member can be performed before molding, during molding, or after molding. For example, a CFRP or CFRP molding prepreg may be bonded to the metal member after a metal material, which is a workpiece, is molded into the metal member. Alternatively, a CFRP or CFRP molding prepreg may be bonded to the workpiece by thermocompression bonding, and then the workpiece to which the CFRP member is bonded is molded to obtain a composite metal member. If the matrix resin of the CFRP member is a thermoplastic resin, the portion where the CFRP member is bonded can be formed by bending or the like. Further, when the matrix resin of the CFRP member is a thermoplastic resin, composite batch molding in which the thermocompression bonding step and the molding step are integrated may be performed.

  In addition, the joining method of a CFRP member and a metal member is not restricted to the adhesion | attachment by the adhesive resin layer mentioned above. For example, the CFRP member and the metal member may be mechanically joined. More specifically, a fastening hole is formed at a position corresponding to each of the CFRP member and the metal member, and these are fastened through the hole by fastening means such as a bolt or a rivet, whereby the CFRP member and the metal member are fastened. The member may be joined. In addition, the CFRP member and the metal member may be joined by a known joining means. In addition, the CFRP member and the metal member may be joined together by a plurality of joining means. For example, the adhesion by the adhesive resin layer and the fastening by the fastening means may be used in combination.

<Metal member and its surface treatment>
The metal member according to the present invention may be plated. Thereby, corrosion resistance improves. In particular, it is more suitable when the metal member is a steel material. The type of plating is not particularly limited, and known plating can be used. For example, as a galvanized steel sheet (steel material), a galvanized steel sheet, a galvannealed steel sheet, a Zn-Al-Mg alloy-plated steel sheet, an aluminum-plated steel sheet, an electrogalvanized steel sheet, an electric Zn-Ni alloy-plated steel sheet, etc. Can be used.

  Moreover, the metal member may be coated with a film called chemical conversion treatment on the surface. Thereby, corrosion resistance improves more. As the chemical conversion treatment, a generally known chemical conversion treatment can be used. For example, as the chemical conversion treatment, zinc phosphate treatment, chromate treatment, chromate-free treatment or the like can be used. Further, the film may be a known resin film.

  In addition, the metal member may be one that has been generally painted. Thereby, corrosion resistance improves more. As the coating, a known resin can be used. For example, as a coating, an epoxy resin, a urethane resin, an acrylic resin, a polyester resin, or a fluorine resin can be used as a main resin. Moreover, generally well-known pigment may be added to the coating as needed. The coating may be a clear coating to which no pigment is added. Such coating may be applied to the metal member in advance before the CFRP member is combined, or may be applied to the metal member after the CFRP member is combined. Alternatively, the CFRP member may be combined after the metal member has been painted in advance, and then painted. The paint used for painting may be a solvent-based paint, a water-based paint, a powder paint, or the like. In general, a known method can be applied as a method of painting. For example, electrodeposition coating, spray coating, electrostatic coating, immersion coating, or the like can be used as a coating method. Since electrodeposition coating is suitable for coating the end face and gap portion of a metal member, it is excellent in corrosion resistance after coating. Moreover, coating film adhesion improves by performing generally well-known chemical conversion treatments, such as a zinc phosphate process and a zirconia process, on the surface of a metal member before coating.

  In order to evaluate the impact resistance due to the difference in the configuration of the center pillar inner, an analysis model as shown in FIG. 12 was created and a side collision simulation was performed. The simulation conditions conform to the conditions of the side impact test of JNCAP. Table 1 below shows the configuration of each center pillar for which a side collision simulation was performed.

  The center pillar inner of Comparative Example 1 is composed only of a 340 MPa class steel plate having a plate thickness of 0.95 mm. The center pillar inner of Comparative Example 2 is composed of only a 340 MPa grade steel plate having a plate thickness of 0.6 mm. The steel plate of Comparative Example 2 is a so-called thinned steel plate that is thinner than the steel plate of Comparative Example 1.

  The center pillar inner of Example 1 has a configuration in which a CFRP member having a thickness of 2 mm is attached to the entire surface of the steel plate of Comparative Example 2 using an adhesive, and is the same as that of the first embodiment shown in FIG. It is a configuration. The center pillar inner of Example 2 has a configuration in which a CFRP member having a thickness of 2 mm is attached to the entire lower portion and flange portion of the steel plate of Comparative Example 2 using an adhesive. The second pillar shown in FIG. The configuration is the same as that of the embodiment. The center pillar inner of Example 3 has a configuration in which a CFRP member having a thickness of 2 mm is attached to the lower portion of the steel plate of Comparative Example 2 and the flange portion on the side of the opening using an adhesive. This is the same configuration as the fourth embodiment shown in FIG. The center pillar outer is common in each example, and is composed of only 1.5 GPa class hot stamped steel plate. In addition, the numerical value in the parenthesis described in the item of total weight in Table 1 indicates a difference from the total weight of the center pillar of Comparative Example 2.

  In the side collision simulation carried out under the above conditions, the amount of intrusion of the center pillar into the vehicle and the weight efficiency at the ground height corresponding to the chest and waist of the occupant were evaluated. In Table 2 below, the rate of change of the amount of penetration of the pillars in the center pillars of Comparative Example 1 and Examples 1 to 3 with respect to the center pillar of Comparative Example 2 (reduction in collision in Table 2) and weight efficiency (reduction in collision / weight increase) ).

  As shown in Table 2, in the center pillars in Examples 1 to 3, the weight efficiency related to the collision reducing effect was improved in both the chest and the waist as compared with the center pillar in Comparative Example 1 in which the plate thickness of the inner member was large. Further, in this simulation, the effect of improving the weight efficiency for the chest was the largest in Example 1, and the effect of improving the weight efficiency for the waist was the largest in Example 2. Also in Example 3, the effect of improving the weight efficiency with respect to the waist is equal to that of Example 2, and the weight efficiency is excellent.

  Although the center pillar of Example 1 is not necessarily light in weight reduction effect compared to Comparative Example 1 in which the plate thickness of the inner member is large, in view of the results shown in Table 2 above, the center pillar inner of Example 1 In the case of the configuration, it is estimated that sufficient impact resistance can be obtained even if the plate thickness of the inner member is further reduced. For this reason, the impact resistance equivalent to or higher than that of Comparative Example 1 can be ensured while further reducing the weight. Therefore, if the center pillar inner of Example 1 is used, both weight reduction and impact resistance can be achieved.

  The collision reduction effect of the center pillar of Example 2 is equivalent to that of Comparative Example 1 in both the chest and waist, but the weight efficiency is improved. Therefore, if the center pillar inner of Example 2 is used, both weight reduction and impact resistance can be achieved. In addition, the impact reduction effect of the center pillar of Example 3 is equivalent to that of Comparative Example 1 in which the impact resistance of the center pillar as a whole including the chest and waist is large. In addition, as shown in Table 2, the center pillar of Example 3 has a large weight reduction effect with respect to Comparative Example 1 in which the plate thickness of the inner member is large. Therefore, if the center pillar inner of Example 3 is used, both weight reduction and impact resistance can be achieved. Moreover, in Example 3, since the effect of weight reduction is large with respect to Comparative Example 1, even if the plate thickness of the CFRP member is increased by, for example, about 0.1 mm to improve the impact resistance, the Comparative Example 1 is improved. The effect of weight reduction can be sufficiently obtained.

  In addition, the configuration of the center pillar inner of Example 3 is such that a CFRP member is provided on the lower part of the inner member and the flange part on the side of the opening. It is presumed that sufficient impact resistance can be obtained even when the CFRP member is provided only at the lower portion of the inner member where the plastic strain sometimes increases. Therefore, even if the CFRP member is a center pillar inner provided only at the lower part of the inner member, both weight reduction and impact resistance can be achieved, and the cost of the material can be suppressed.

  The present invention can be used for an automobile center pillar.

1 Center Pillar 10 Center Pillar Outer 10a Center Pillar Outer Flange 20 Center Pillar Inner 21 Inner Member 21a Inner Member Opening 21b Inner Member Side Sill Mounting 21c Inner Member Upper End 21d Inner Member Flange 21d ′ Opening Side flange portion 21e Inner member lower portion 22 CFRP member 22a CFPR member hole 30 Side sill

Claims (5)

An inner member having an opening serving as a seat belt retractor mounting position and a side sill mounting section serving as a side sill mounting position;
A CFRP member joined to the surface of the inner member,
A center pillar inner in which the CFRP member is provided at least between the opening and the side sill attachment.   The center pillar inner according to claim 1, wherein the CFRP member is further provided on a flange portion of the inner member on the side of the opening.   The center pillar inner according to claim 2, wherein the CFRP member is further provided at a flange portion of the inner member positioned above the opening.   The center pillar inner according to any one of claims 1 to 3, wherein a matrix resin of the CFRP member is a thermoplastic resin. Center pillar outer,
The center pillar inner according to any one of claims 1 to 4, and
The center pillar, wherein the center pillar outer and the center pillar inner are joined to each other by a flange portion.

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