WO2019198673A1

WO2019198673A1 - T-shaped joint structure

Info

Publication number: WO2019198673A1
Application number: PCT/JP2019/015347
Authority: WO
Inventors: 野樹木本
Original assignee: 日本製鉄株式会社
Priority date: 2018-04-09
Filing date: 2019-04-08
Publication date: 2019-10-17
Also published as: JP6683293B2; JPWO2019198673A1; CN111918812A

Abstract

A T-shaped joint structure comprising: a first member which is a hollow member having a first flat portion and a second flat portion connected to the first flat portion; and a second member which is a hollow member extending perpendicularly to the longitudinal direction of the first member and brought into contact with, and fixed to, the first flat portion of the first member. The second member has a joint portion at which the second member is joined to the second flat portion of the first member. In a cross section perpendicular to the longitudinal direction of the first member, taken so as to include the hollow portion of the second member, the thickness of the second flat portion of the first member is larger than the thickness of the first flat portion of the first member, and the thickness of the joint portion of the second member is larger than the thickness of the portion of the second member other than the joint portion.

Description

T-shaped joint structure

The present invention relates to a T-joint structure that is a joint structure between members.

As a joining structure between members constituting the body of an automobile, for example, there is a T-shaped joint structure such as a joining structure of a side sill and a cross member shown in FIG. Since the body of an automobile is required to have a bending rigidity related to the stability and ride comfort of the vehicle during traveling, and impact resistance to protect an occupant in the event of a collision, It is desired to improve the bending rigidity and impact resistance even at certain locations. In view of this requirement, Patent Document 1 discloses a T-joint structure joined so as to connect the upper surface of the side sill and the upper surface of the cross member.

International Publication No. 2016/076315

FIG. 2 is a view showing a conventional T-shaped joint structure 50 in which the cross member 20 is brought into contact with the top plate portion 12a of the side sill 10, but the T-shaped joint structure of Patent Document 1 is the conventional T-shaped joint shown in FIG. The rigidity and impact resistance of the structure 50 can be greatly improved. However, while the vehicle body of an automobile is required to improve rigidity and impact resistance, it is also required to reduce the weight of the vehicle body in order to improve fuel consumption. In this respect, the T-joint structure of Patent Document 1 has a large increase in weight with respect to the conventional T-joint structure 50, so there is room for further improvement from the viewpoint of weight reduction.

The present invention has been made in view of the above circumstances, and an object of the present invention is to ensure both sufficient bending rigidity and impact resistance and light weight in a T-shaped joint structure.

One aspect of the present invention that solves the above problem is a T-shaped joint structure, which is a hollow member having a first flat surface portion and a second flat surface portion connected to the first flat surface portion. A first member and a second member that is a hollow member that is fixed in contact with the first flat portion of the first member and that extends perpendicular to the longitudinal direction of the first member; The second member has a joint portion that is a portion joined to the second flat portion of the first member, and is cut so as to include a hollow portion of the second member. In addition, in the cross section perpendicular to the longitudinal direction of the first member, the thickness of the second planar portion of the first member is thicker than the thickness of the first planar portion of the first member. And the thickness of the said junction part of the said 2nd member is thicker than the thickness of parts other than the said junction part of the said 2nd member, It is characterized by the above-mentioned. That.

According to the present invention, in a T-shaped joint structure, sufficient bending rigidity and impact resistance can be ensured and light weight can be achieved at the same time.

It is a figure which shows the vehicle body structure of a common motor vehicle. It is a figure which shows the conventional T-joint structure of a side sill and a cross member. It is a perspective view which shows schematic structure of the T-shaped joint structure of the side sill and cross member which concerns on embodiment of this invention. It is a perspective view at the time of seeing FIG. 3 from the bottom. It is the figure which looked at the junction part vicinity of the side sill and cross member of the T-shaped joint structure which concerns on embodiment of this invention from the bottom. It is a figure which shows the cross section perpendicular | vertical with respect to the side sill longitudinal direction cut | disconnected so that the hollow part of a cross member might be included in the T-shaped joint structure which concerns on embodiment of this invention. It is a figure which shows an example of the joining means of a side sill vertical wall part and a cross member flat plate flange part. It is a figure which shows an example of the joining means of the side sill vertical wall part and cross member flat plate flange part in the T-shaped joint structure which concerns on another embodiment of this invention. It is a figure which shows the cross section perpendicular | vertical with respect to the longitudinal direction of a side sill cut | disconnected so that the hollow part of a cross member may be included in the T-shaped joint structure which concerns on another embodiment of this invention. It is a figure which shows the ladder frame of a motor vehicle. It is a figure which shows the analysis model of a deformation | transformation simulation. It is a figure which shows the flat plate flange part of the analysis model shown in FIG. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the shape of the reinforcement member of an analysis model. It is a figure which shows the bending rigidity of an analysis model. It is a figure which shows the amount of out-of-plane deformation of an analysis model. It is a figure which shows the bending rigidity of an analysis model. It is a figure which shows the amount of out-of-plane deformation of an analysis model. It is a figure which shows the bending rigidity of an analysis model. It is a figure which shows the amount of out-of-plane deformation of an analysis model. It is a figure which shows the bending rigidity of an analysis model. It is a figure which shows the amount of out-of-plane deformation of an analysis model. It is a figure which shows the evaluation area | region of bending rigidity and an out-of-plane deformation amount in a deformation | transformation simulation. It is a figure which shows the analysis model of a collision simulation (A). It is a figure which shows the maximum load in each analysis model from which the fiber direction of the reinforcement member which consists of CFRP differs. It is a figure which shows the absorbed energy in each analysis model from which the fiber direction of the reinforcement member which consists of CFRP differs. It is a figure which shows the maximum load in each analysis model from which the thickness of a reinforcement member differs. It is a figure which shows the absorbed energy in each analysis model from which the thickness of a reinforcement member differs. It is a figure which shows the analysis model of a collision simulation (B). It is a figure which shows the maximum load in each analysis model from which the fiber direction of the reinforcement member which consists of CFRP differs. It is a figure which shows the absorbed energy in each analysis model from which the fiber direction of the reinforcement member which consists of CFRP differs. It is a figure which shows the maximum load in each analysis model from which the thickness of a reinforcement member differs. It is a figure which shows the absorbed energy in each analysis model from which the thickness of a reinforcement member differs.

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.

In the present embodiment, an example of a joining structure of an automobile side sill and a cross member (floor cross member) will be described as a T-shaped joint structure. As shown in FIGS. 3 to 6, the T-shaped joint structure 1 of the present embodiment includes a side sill 10 as an example of a first member, a cross member 20 as an example of a second member, and a reinforcing member 30. Has been. Cross member 20 is joined to the side sill 10 in contact with the side sill 10, and is fixed so as to extend perpendicular to the side sill longitudinal L _1. In the present specification, a direction perpendicular to both the side sill longitudinal direction L ₁ and the cross member longitudinal direction L ₂ is referred to as a “height direction H”. In the case of the joining structure of the side sill 10 and the cross member 20 as in this embodiment, the side sill longitudinal direction L ₁ is the vehicle length direction, the cross member longitudinal direction L ₂ is the vehicle width direction, and the height direction H is the vehicle height direction.

In the side sill 10 of this embodiment, a flat plate 11 is used as an outer member, and a member whose cross-sectional shape perpendicular to the side sill longitudinal direction L ₁ is a hat shape (hereinafter referred to as “hat-shaped member 12”) is used as an inner member. It has been. The hat-shaped member 12 includes a top plate portion 12a, a vertical wall portion 12b extending perpendicularly to the top plate portion 12a from both ends in the height direction H of the top plate portion 12a, and a height from the distal end portion of the vertical wall portion 12b. And a flange portion (hereinafter referred to as “hat flange portion 12c”) extending outward in the vertical direction H. The flat plate 11 and the hat flange portion 12c are joined by, for example, spot welding. In addition, the structure of the outer member and inner member of the side sill 10 is not limited to what was demonstrated by this embodiment. For example, the outer member may be a hat-like member as with the inner member. That is, the side sill 10 may be a hollow member having a hollow portion 10a.

Cross member 20 of the present embodiment, the flat plate 21 is used as an outer member, as an inner member, member shape of the cross section perpendicular to the cross member longitudinally L ₂ is hat-shaped (hereinafter, "hat-shaped member 22") Is used. Hat member 22 includes a top plate portion 22a, and a vertical wall portion 22b which extends perpendicularly to the side sill longitudinal direction L ₁ of the top plate portion 22a from both ends of the top plate portion 22a, the distal end portion of the vertical wall portion 22b a flange portion extending outwardly of the side sill longitudinal L ₁ (hereinafter, "hat flange 22c") and a. The flat plate 21 and the hat flange portion 22c are joined by, for example, spot welding. In addition, the structure of the outer member and inner member of the cross member 20 is not limited to what was demonstrated by this embodiment. For example, the outer member may be a hat-like member as with the inner member. The flat plate 21 may be a floor panel (not shown). In this case, the cross member 20 in which a hollow portion is formed by a part of the floor panel and the hat-shaped member is configured. That is, the cross member 20 may be a hollow member having a hollow portion 20a.

Of the both ends of the cross member 20 in the longitudinal direction L _2, the end of the cross member 20 that contacts the side sill 10 (hereinafter referred to as “contact side end 23”) extends in the height direction from the top plate 22 a of the cross member 20. A flange portion extending to H (hereinafter referred to as “top plate flange portion 23 a”), a flange portion extending from the vertical wall portion 22 b to the outside in the side sill longitudinal direction L ₁ (hereinafter referred to as “vertical wall flange portion 23 b”); A flange portion (hereinafter referred to as “flat plate flange portion 23 c”) extending from the plate portion 21 a in the cross member longitudinal direction L ₂ is formed. The top plate flange portion 23a and the vertical wall flange portion 23b are joined together by, for example, single-side spot welding in a state where the top plate flange portion 23a and the vertical wall flange portion 23b are in contact with the top plate portion 12a of the side sill 10. The flat plate flange 23c is joined by, for example, single-side spot welding in a state where the side sill 10 is in contact with the vertical wall 12b on the vehicle outer side in the height direction H. Thus, the side sill 10 and the cross member 20 are fixed by joining the top-plate flange part 23a, the vertical wall flange part 23b, and the flat plate flange part 23c to the side sill 10.

The reinforcing member 30 of the present embodiment has a rectangular shape in plan view, and the side sill 10 and the cross member straddle the vertical wall portion 12b on the vehicle outer side in the height direction H of the side sill 10 and the flat plate 21 of the cross member 20. 20 is joined. In the present embodiment, one end of the reinforcing member 30 in the cross member longitudinal direction L ₂ is positioned near the hat flange portion 12 c of the side sill 10, and the other end is the cross member 20. It is located inside the vehicle of the cross member longitudinally L ₂ with respect to the boundary position between the plate portion 21a and the flat flange portion 23c of the flat plate 21 of.

The joining position of the reinforcing member 30 with respect to the side sill 10 and the cross member 20 is not particularly limited as long as the reinforcing member 30 is joined so as to straddle both the

members

10 and 20, but the cross member 20 has the flat flange portion 23c as in the present embodiment. In this case, one end portion of the reinforcing member 30 in the cross member longitudinal direction L ₂ is located on the vehicle outer side in the cross member longitudinal direction L ₂ with respect to the tip of the flat plate flange portion 23c, and the other end of the reinforcing member 30 it is preferred that the ends of the are located inside the vehicle of the cross member longitudinally L ₂ with respect to the boundary position between the plate portion 21a and the flat flange portion 23c of the plate 21. That is, it is preferable that the reinforcing member 30 is joined across the side sill 10 and the cross member 20 so as to cover the flat plate flange portion 23c. Thereby, the impact resistance of the T-shaped joint structure 1 can be improved. The length of the cross member longitudinal direction L ₂ of the reinforcing member 30, the bending rigidity or impact resistance is required, or is changed according to the weight limit and the like.

Although the joining method of the reinforcing member 30 to the side sill 10 and the cross member 20 is not particularly limited, for example, the side sill 10 and the cross member 20 are joined by being attached to each other using an adhesive. For this reason, the T-shaped joint structure 1 of the present embodiment, for example, joins the cross member 20 to the side sill 10 and then covers the flat flange portion 23c of the cross member 20 so as to cover the vertical wall portion 12b of the side sill 10 and the cross member. It is manufactured by sticking the reinforcing member 30 so as to straddle the 20 flat plates 21. In the case of using an adhesive, if the cross section of the joint portion between the side sill 10 or the cross member 20 and the reinforcing member 30 is observed, the adhesive exists between the side sill 10 or the cross member 20 and the reinforcing member 30. Can be confirmed. When the reinforcing member 30 is made of, for example, CFRP (carbon fiber reinforced resin), the CFRP may be thermosetting, but is preferably thermoplastic from the viewpoint of moldability and adhesiveness. . *

The T-joint structure 1 of the present embodiment is configured as described above. In the case of the conventional T-joint structure, when the cross member 20 is bent in the side sill longitudinal direction L ₁ (hereinafter referred to as “lateral bending”), the flat plate flange portion 23c of the cross member 20 is deformed in the height direction H. Due to the occurrence of (out-of-plane deformation), out-of-plane deformation is likely to occur in the vertical wall portion 12b on the vehicle exterior side of the side sill 10.

On the other hand, in the T-shaped joint structure 1 of the present embodiment, the reinforcing member 30 is joined so as to straddle the side sill 10 and the cross member 20, thereby suppressing out-of-plane deformation of the flat plate flange portion 23 c of the cross member 20. Therefore, the out-of-plane deformation of the vertical wall portion 12b of the side sill 10 at the joint portion is suppressed. Thereby, the bending rigidity with respect to the lateral bending of the T-shaped joint structure 1 can be improved. In addition, since the degree of out-of-plane deformation of the vertical wall portion 12b of the side sill 10 can be suppressed even during a side collision, the impact resistance of the T-shaped joint structure 1 can be improved.

Further, according to the T-shaped joint structure 1 of the present embodiment, the increase in weight with respect to the degree of improvement in bending rigidity and impact resistance against lateral bending is small, and the weight efficiency in terms of bending rigidity and impact resistance against lateral bending is improved. To do. In other words, even when the thickness of the side sill 10 and the cross member 20 is reduced for weight reduction, sufficient bending rigidity and impact resistance can be ensured.

Here, the length in the side sill longitudinal direction L ₁ of the reinforcing member 30 shown in FIG. 5 is referred to as “width W _a of the reinforcing member 30”, and the side sill longitudinal direction L _{1 in} the joining region of the side sill 10 and the flat plate flange portion 23 c is referred to. The length is referred to as “joining region width W _b ”. The width W _a of the reinforcing member 30 is appropriately changed according to required bending rigidity or impact resistance, weight limit, or the like, but preferably satisfies W _b ≦ 2W _a . By satisfying this condition, out-of-plane deformation of the vertical wall portion 12b of the side sill 10 can be further suppressed, and bending rigidity and impact resistance can be improved. In the case where the flat flange portion 23c of the vertical wall portion 12b and the cross member 20 of the side sill 10 as shown in FIG. 5 are joined by spot welding, and the width W _b of the joining region, along the side sill longitudinal direction L ₁ This is the distance between spot hit points located at both ends of the spot hit points arranged side by side. Further, the vertical wall portion 12b and the flat flange portion 23c and, for example, laser welding as shown in FIG. 7, a continuous welding arc welding or the like, or if it is joined with an adhesive, and the width W _b of the junction region, the welding region or from one end of the side sill longitudinal direction L ₁ of the adhesive area to the other in length. The thickness of the reinforcing member 30 is appropriately changed according to the required bending rigidity or impact resistance, weight limit, or the like, and is preferably 1 to 5 mm, for example.

Further, when the reinforcing member 30 is made of, for example, CFRP, the amount of the reinforcing member 30 that can be used in the T-shaped joint structure 1 as in the present embodiment is melted as the scrap to which the reinforcing member 30 is joined. Even when reused, the steel impurities will not increase excessively. That is, the T-joint structure 1 of this embodiment is excellent in recyclability because it is not necessary to separate the side sill 10, the cross member 20, and the reinforcing member 30 when reusing parts as scrap. .

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, as shown in FIG. 8, a slit S may be provided in the reinforcing member 30. The slit S is parallel to the cross member longitudinal direction L ₂ of the reinforcing member 30. In the example shown in FIG. 8, the slit S is provided at the center of the reinforcing member 30 in the side sill longitudinal direction L ₁ . That is, in the example shown in FIG. 8, the two reinforcing

members

30a and 30b are joined to the side sill 10 and the cross member 20 at intervals. Also in such a T-shaped joint structure 1, the out-of-plane deformation of the flat plate flange portion 23c of the cross member 20 is suppressed, and the out-of-plane deformation of the vertical wall portion 12b of the side sill 10 at the joint portion is suppressed. Thereby, the bending rigidity with respect to the lateral bending of the T-shaped joint structure 1 can be improved. In addition, since the degree of out-of-plane deformation of the vertical wall portion 12b of the side sill 10 can be suppressed even during a side collision, the impact resistance of the T-shaped joint structure 1 can be improved. Furthermore, weight reduction as the T-shaped joint structure 1 can be promoted.

The position in the side sill longitudinal direction L ₁ of the slit S provided in the reinforcing member 30 is not limited to the central portion exemplified in FIG. Moreover, the slit S may be provided with two instead of one. In this specification, the width W _a of the reinforcing member 30 when the slit S is provided refers to the side sill of the reinforcing members (reinforcing

members

30 a and 30 b in the example of FIG. 8) arranged along the side sill longitudinal direction L ₁ . It is the distance between the ends of the reinforcing members located at both ends in the longitudinal direction L ₁ that are farthest from each other. The width W _{c of the} slit S (the length in the side sill longitudinal direction L ₁ ) is appropriately changed according to the required bending rigidity or impact resistance, weight limit, or the like, but the width W _a of the reinforcing member 30 is 80 % Or less is preferable. Thereby, the bending rigidity of the T-shaped joint structure 1 can be increased more effectively. Note that the width W _c of the slit S when a plurality of the slits S are provided is the total value of the widths of the slits S, and in this case as well, it is preferably 80% or less of the width W _a of the reinforcing member 30.

For example, in the above-described embodiment, the bending rigidity is improved by joining the reinforcing member 30 so as to straddle the side sill 10 and the cross member 20. However, for example, as shown in FIG. the thickness of 12b, as well as thicker than the other planar portion of the side sill 10 (e.g. the top plate portion 12a), out of both end portions in the longitudinal direction L ₂ of the cross member 20 is joined to the vertical wall portion 12b of the side sill 10 The end portion 21b of the flat plate 21 on the other side may be thicker than the other portion of the cross member 20 (for example, the top plate portion 22a). Even in such a T-shaped joint structure 1, since the out-of-plane deformation in the vicinity of the flat plate flange portion 23c of the cross member 20 is effectively suppressed, the bending rigidity can be improved. Moreover, impact resistance can be improved with improvement in bending rigidity. In the case of the T-shaped joint structure 1 shown in FIG. 9, the hat-shaped member 12 of the side sill 10 and the flat plate 21 of the cross member 20 are manufactured by casting, for example. Incidentally, the thickness of the exterior of the vertical wall portion 12b of the side sill 10 only needs thicker than at least a portion, for example, the top plate portion 12a of the cross member longitudinally L _2.

Moreover, as a kind of the cross member 20 of the said embodiment, the roof cross joined to a roof side rail other than the floor cross member joined to the side sill 10, a front cross member, and a rear cross member, for example like FIG. There are also members. For this reason, the T-joint structure 1 may be, for example, a joint structure of a roof side rail and a roof cross member. When the T-joint structure is a joint structure of a roof side rail and a roof cross member, the longitudinal direction of the roof side rail is the vehicle length direction, the longitudinal direction of the roof cross member is the vehicle width direction, and the height direction H is the vehicle height direction. . Further, the T-joint structure may be a joint structure of a cross-beam type subframe, or may be a T-joint structure of another part included in the vehicle body structure of an automobile. For example, a T-joint structure can be employed in a ladder frame as shown in FIG. Further, the T-shaped joint structure is not limited to the automobile field, and can be used as a T-shaped joint structure between members in other fields. Even in this case, as in the above-described embodiment, sufficient bending rigidity and impact resistance can be ensured and the weight can be reduced.

Further, if the side sill 10 and the cross member 20 described in the above embodiment are rephrased as “first member” and “second member”, for example, the T-shaped joint structure shown in FIG. In a cross section perpendicular to the longitudinal direction L1 of the _first member cut so as to include the hollow portion, the first flat portion of the first member (the top plate portion 12a of the side sill 10 in the example of FIG. 9). It can be said that the thickness of the connected second plane portion (the vertical wall portion 12b of the side sill 10 in the example of FIG. 9) is thicker than the first plane portion of the first member. Moreover, T-shaped coupling structure shown in FIG. 9, in a cross section perpendicular to the longitudinal direction L ₁ of the first member, the second member, a moiety that is bonded to the second planar portion of the first member It can be said that the thickness of the joint portion (the end portion 21b of the flat plate 21 in the example of FIG. 9) is thicker than the thickness of the second member other than the joint portion. When the T-joint structure is a joint structure of a roof side rail and a roof cross member, the roof side rail is a first member and the roof cross member is a second member.

In the present specification, the “first flat surface portion” and the “second flat surface portion” of the first member refer to the hollow portion of the first member (the example of FIG. 6) among the flat surface portions of the first member. Then, it means a flat portion constituting the hollow portion 10a) of the side sill 10. For example, when the first member is a side sill 10 as shown in FIG. 6, the hollow portion 10a is composed of the top plate portion 12a of the hat-shaped member 12, the vertical wall portion 12b, and the flat plate 11, and the hat flange portion 12c. Although it is a plane part, it does not contribute to the structure of the hollow part 10a. For this reason, the hat flange portion 12c is not the first plane portion or the second plane portion in this specification.

Further, in the “second flat surface portion” of the first member in this specification, a reinforcing member is joined to a plate member, for example, in addition to the case where the flat surface portion is formed of a single member. The case where it comprises with a complex member is also included. For example, in the case of a T-shaped joint structure as shown in FIG. 6, the vertical wall portion 12 b of the side sill 10 and the reinforcing member 30 are joined to the second flat portion connected to the top plate portion 12 a of the side sill 10 corresponding to the first flat portion. It is comprised by the composite member made. Therefore, the “thickness of the second planar portion” of the first member in the example of FIG. 6 is the sum of the plate thickness of the vertical wall portion 12b and the plate thickness of the reinforcing member 30. That is, when the reinforcing member is joined so as to straddle the first member and the second member, the thickness of the second planar portion of the first member is increased by the thickness of the reinforcing member. Therefore, in the first member, the thickness of the plate-like member (the vertical wall portion 12b in the example of FIG. 6) connected to the first flat portion is the thickness of the first flat portion (the top plate portion in the example of FIG. 6). Even if it is the same as 12a), the thickness of the second planar portion (the sum of the plate thickness of the plate-like member and the plate thickness of the reinforcement member) is the first by joining the reinforcing member to the plate-like member. It becomes thicker than the thickness of the flat part. On the other hand, for example, in the case of a T-shaped joint structure as shown in FIG. 9, the second flat surface portion of the first member is composed only of the vertical wall portion 12 b of the side sill 10, so The “thickness of the second plane portion” of the member is the plate thickness of the vertical wall portion 12b.

In addition, the “joining portion” of the second member in the present specification includes a composite member in which the reinforcing member is joined to a plate-like member, for example, in addition to the case where the portion is constituted by a single member. It is also included when configured. For example, in the case of the T-shaped joint structure as shown in FIG. 6, the joint portion of the cross member 20 corresponding to the second member is composed of a composite member in which the end portion 21 b of the flat plate 21 and the reinforcing member 30 are joined. . Therefore, the “joint thickness” of the second member in the example of FIG. 6 is the sum of the thickness of the end 21 b of the flat plate 21 and the thickness of the reinforcing member 30. That is, when the reinforcing member is joined so as to straddle the first member and the second member, the thickness of the joining portion of the second member is increased by the thickness of the reinforcing member. Therefore, in the second member, even if the thickness of the plate member (the flat plate 21 in the example of FIG. 6) joined to the second flat portion of the first member is constant, the plate member is reinforced. By joining the members, the thickness of the second member at the joint portion with the first member (the sum of the plate thickness at the end of the plate-like member and the plate thickness of the reinforcing member) is the same as that of the second member. It becomes thicker than the thickness of the part other than the joint part. On the other hand, for example, in the case of the T-shaped joint structure as shown in FIG. 9, since the joint portion of the second member is composed only of the end portion 21 b of the flat plate 21, the “joint portion of the second member in FIG. The “thickness” is the thickness of the end 21 b of the flat plate 21.

Note that the material of the reinforcing member is not particularly limited. The reinforcing member may be a member made of FRP (fiber reinforced resin) such as a member made of CFRP (carbon fiber reinforced resin) or a member made of GFRP (glass fiber reinforced resin). Further, the reinforcing member may be an aluminum alloy member, a magnesium alloy member, a steel material, or the like. Further, the reinforcing member may be a composite member made of the plurality of materials described above.

<Type of reinforcing member made of FRP>
The reinforcing member made of FRP means a fiber reinforced resin member made of a matrix resin and a reinforced fiber material contained in the matrix resin and combined.

As the reinforcing fiber material, for example, carbon fiber or glass fiber can be used. In addition, boron fiber, silicon carbide fiber, aramid fiber, or the like can be used as the reinforcing fiber material. In FRP, as the reinforcing fiber base material used as the base material of the reinforcing fiber material, for example, a nonwoven fabric base material using chopped fibers, a cloth material using continuous fibers, a unidirectional reinforcing fiber base material (UD material), etc. are used. can do. These reinforcing fiber bases can be appropriately selected according to the orientation of the reinforcing fiber material.

The reinforcing member made of CFRP is a reinforcing member made of FRP using carbon fiber as a reinforcing fiber material. 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.

The reinforcing member made of GFRP is a reinforcing member made of FRP using glass fiber as a reinforcing fiber material. Although it is inferior to a carbon fiber in mechanical characteristics, it can suppress the electric corrosion of a metal member.

Either a thermosetting resin or a thermoplastic resin can be used as the matrix resin used for the reinforcing member made of FRP. Examples of the thermosetting resin include epoxy resins, unsaturated polyester resins, and vinyl ester resins. Thermoplastic resins include 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.

In consideration of application to metal members, it is preferable to use a thermoplastic resin as the 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 reinforcing member made of FRP, the tact time, the workability, and the like.

<Adhesive resin layer>
When the reinforcing member is formed of FRP or the like, an adhesive resin layer is provided between the reinforcing member made of FRP and the metal member (in the above embodiment, the side sill 10 and the cross member 20). The reinforcing member and the metal member may be joined.

The type of the adhesive resin composition that forms the adhesive resin layer is not particularly 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. For example, as thermoplastic resins, 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 reinforcing member made of FRP, 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, by adhering the reinforcing member made of FRP to the metal member using the above-described adhesive resin layer, the adhesion between the reinforcing member made of FRP and the metal member can be improved. If it does so, the deformation | transformation followable | trackability of the reinforcement member which consists of FRP when a load is input with respect to a metal member can be improved. In this case, the effect of the reinforcing member made of FRP on the deformed body of the metal member can be more reliably exhibited.

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

Also, a crosslinkable adhesive resin composition may be formed by blending a crosslinkable curable resin and a crosslinker into the 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 composite of the reinforcing member made of FRP into the metal member can be realized by various methods. For example, FRP as a reinforcing member made of FRP or a prepreg for FRP molding that is a precursor thereof and a metal member are bonded with the above-described adhesive resin composition, and the adhesive resin composition is solidified (or cured). It is obtained by. In this case, for example, the reinforcing member made of FRP and the metal member can be combined by performing thermocompression bonding.

Further, the reinforcing member may be formed by overlaying as an overlaying part. In this case, the type of metal used for overlaying is appropriately determined in view of the characteristics of the metal member with the base material. Moreover, the joining method with a metal member is not restricted to welding, A various appropriate joining method can be used.

<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 galvanized steel sheets (steel materials), hot dip galvanized steel sheets, galvannealed steel sheets, Zn—Al—Mg alloy plated steel sheets, aluminum plated steel sheets, electrogalvanized steel sheets, electric Zn—Ni alloy plated steel sheets, etc. Can be used.

Further, the metal member may have a surface coated with a film called chemical conversion treatment. 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 is 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 reinforcing member made of FRP is combined, or may be applied to the metal member after combining the reinforcing member made of FRP. Further, after the metal member is previously painted, a reinforcing member made of FRP may be combined, and further 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.

<Deformation simulation>
In order to evaluate the bending rigidity of the T-joint structure according to the present invention, an analysis model shown in FIG. 11 was created and a deformation simulation was performed. The analysis model includes a side sill 10, a cross member 20 joined to the top plate portion 12a of the side sill 10, and a reinforcing member 30 made of CFRP. The vertical wall portion 12b of the side sill 10 and the flat plate flange portion 23c of the cross member 20 are joined by spot welding. Of the spot hitting points arranged along the side sill longitudinal direction L ₁ , the distance between the hitting points at both ends, that is, the width of the aforementioned joining region W _b is 60 mm. In each of the following simulations including this simulation, the material of the side sill 10 and the cross member 20 is a 1.5 GPa grade steel plate, the thickness of the side sill 10 is 0.8 mm, and the thickness of the cross member 20 is 1. 4 mm. Also, the flat flange portion 23c, as shown in FIG. 12, the length in the longitudinal direction L ₂ of the cross member 20 is 29 mm.

In this simulation, as shown in Tables 1 to 4 below, a plurality of analysis models having different shapes and sizes of reinforcing members are created. The 0 ° direction in the CFRP orientation in Tables 1 to 4 is a direction parallel to the longitudinal direction L ₂ of the cross member 20. The reinforcing member used has an elastic modulus in the fiber direction of 131.5 GPa and an elastic modulus in the direction orthogonal to the fibers of 8.5 GPa. The breaking stress in the fiber direction is 2490 MPa, and the breaking stress in the direction perpendicular to the fiber is 76 MPa.

In the analysis models of Examples 1 to 5 and Comparative Example 6 shown in Table 1 above, the length of the reinforcing member 30 is changed with the R stop of the connecting portion between the vertical wall portion 12b and the flange portion 12c of the side sill 10 as a starting point. (See FIGS. 13 to 18). The analysis models of Examples 7 to 10 and Comparative Example 11 shown in Table 2 above are based on the analysis model of Example 5 and the length of the reinforcing member 30 starts from the position of the end of the reinforcing member 30 on the cross member 20 side. This is a modified model (see FIGS. 19 to 23). The analysis models of Examples 12 to 14 shown in Table 3 are models in which the width of the reinforcing member 30 is changed based on the analysis model of Example 1 (see FIGS. 24 to 26). In the analysis model of Comparative Example 6, the reinforcing member 30 is joined only to the vertical wall portion 12b of the side sill 10, and is not joined to the flat plate flange portion 23c of the cross member 20. In the analysis model of Comparative Example 11, the reinforcing member 30 is joined only to the flat plate flange portion 23 c of the cross member 20, and is not joined to the vertical wall portion 12 b of the side sill 10. Further, in the analysis model of Example 14, but the reinforcing member 30 is joined so as to extend to the flat flange portion 23c of the vertical wall portion 12b and the cross member 20 of the side sill 10, and the width W _a of the reinforcing member 30 In relation to the width W _b of the junction region, W _b ≦ 2W _a is not satisfied. In the analysis models of Examples 1 to 5, Examples 7 to 10, and Examples 12 to 13, the reinforcing member 30 is joined so as to straddle the vertical wall portion 12b of the side sill 10 and the flat plate flange portion 23c of the cross member 20. And W _b ≦ 2W _a is satisfied.

The analysis models of Examples 15 to 18 shown in Table 4 are models in which a slit S is provided in the center of the reinforcing member 30 and the width of the slit S is changed based on the analysis model of Example 1. (See FIGS. 27 to 30).

In deformation simulation, the cross-section of both ends in the longitudinal direction L ₁ of the side sill 10 is fully constrained. Further, of the both end portions of the cross member 20 in the longitudinal direction L ₂ , the end portion on the side that does not contact the side sill 10 (hereinafter referred to as “non-contact side end portion”) is allowed to be displaced in the height direction H. The cross section is constrained so as not to cause in-plane deformation. Under such restraint conditions, a deformation simulation assuming a lateral bending of the cross member 20 was performed by inputting a load F (200 N) in the side sill longitudinal direction L ₁ to the non-contact side end of the cross member 20. .

As simulation results, the bending stiffness and out-of-plane deformation in each analysis model are shown in FIGS. 39. The evaluation area of the bending rigidity and the amount of out-of-plane deformation is an area of 8.8 mm from the spot welding spot position on the flat plate flange portion 23c of the cross member 20 to the flange portion 12c side of the side sill 10, as shown in FIG. is there. “Bending stiffness” is a load (kN) per unit displacement (mm) generated in each analysis model, and shows a value when the result in the analysis model without reinforcement is 1.

As shown in FIGS. 31 to 38, in the embodiment according to the present invention, since the reinforcing member is provided so as to straddle the side sill 10 and the cross member 20, the bending rigidity is improved and the out-of-plane deformation amount is suppressed. Has been. That is, in the T-shaped joint structure according to the present invention, the weight efficiency of the bending rigidity with respect to the lateral bending is greatly improved. Thereby, for example, even when the thickness of the side sill or the cross member is reduced for weight reduction, the T-joint structure according to the present invention can ensure sufficient bending rigidity. Therefore, according to the T-shaped joint structure according to the present invention, it is possible to achieve both sufficient bending rigidity and light weight.

As shown in FIGS. 35 and 36, in the analysis model of Example 14, the bending rigidity is improved compared to the analysis model in which the reinforcing member is not provided, and the effect of suppressing out-of-plane deformation is obtained. In the case of the structure as in Example 14, for example, the bending rigidity can be effectively improved by increasing the thickness of the reinforcing member as necessary.

Also, as shown in FIGS. 37 and 38, the bending rigidity equivalent to that of Example 1 is exhibited even when the reinforcing member is provided with slits as in the analysis models of Examples 15 to 18. If the slit is provided, it is possible to further promote weight reduction while having a bending rigidity equal to or higher than that of the first embodiment. According to the result of this example, in order to more effectively improve the bending rigidity of the T-shaped joint structure when the slit is provided, the width of the slit is preferably 80% or less of the width of the reinforcing member. .

Next, in order to evaluate the impact resistance of the T-shaped joint structure according to the present invention, a collision simulation was performed using the analysis model of Example 1. In the collision simulation, both end portions of the side sill 10 in the longitudinal direction L ₁ are completely restrained.

<Collision simulation (A)>
The collision simulation (A) is a simulation simulating a pole side collision. Crash simulation, as shown in FIG. 40 (A) is a cross member 20 abuts was performed by applying the impactor in a central portion of the side sill longitudinal L ₁ of the flat plate 11. More specifically, the simulation was performed by causing an impactor having a diameter of 254 mm to collide from the outside of the side sill 10 at a position on the center line of the cross member 20 and the entire height of the side sill 10 at 500 mm / s. Then, the impact resistance of the analytical model was evaluated by evaluating the maximum load (reaction force) and absorbed energy when the impactor stroke was 30 mm.

The analysis model shown in Table 5 below was created and simulated.

* The 0 ° direction is a direction parallel to the longitudinal direction L ₂ of the cross member 20.

As simulation results, the maximum load in the analysis models of Examples 19 to 21 with different CFRP orientations is shown in FIG. 41, and the absorbed energy in the analysis models of Examples 19 to 21 is shown in FIG. As shown in FIGS. 41 and 42, in the T-joint structure according to the present invention, the maximum load and the absorbed energy are increased as compared with the conventional T-joint structure in which the reinforcing member is not provided.

As a simulation result, the maximum load in the analysis models of Examples 22 to 23 in which the thicknesses of the reinforcing members are different from each other is shown in FIG. 43, and the absorbed energy in the analysis models of Examples 22 to 23 is shown in FIG. As shown in FIGS. 43 and 44, the T-joint structure according to the present invention has an increased maximum load and absorbed energy compared to the conventional T-joint structure in which no reinforcing member is provided.

<Collision simulation (B)>
The collision simulation (B) is a simulation simulating a pole side collision, but the position of the impactor is different from the above-described collision simulation (A). As shown in FIG. 45, in the collision simulation (B), the impactor is applied to a position offset in the side sill longitudinal direction L ₁ from the center of the flat plate 11 of the side sill 10 with which the cross member 20 abuts. More specifically, the simulation is performed by causing an impactor having a diameter of 254 mm to collide at 500 mm / s from the outside of the side sill 10 at a position offset by 100 mm in the side sill longitudinal direction L ₁ from the center line of the cross member 20 and over the entire height of the side sill 10. It was done. The analysis model is a model shown in Table 6 below.

As simulation results, FIG. 46 shows the maximum load in the analytical models of Examples 19 to 21 with different CFRP orientations, and FIG. 47 shows the absorbed energy in the analytical models of Examples 19 to 21. As shown in FIGS. 46 and 47, the maximum load and the absorbed energy of the T-joint structure according to the present invention are increased compared to the conventional T-joint structure in which the reinforcing member is not provided.

As simulation results, the maximum load in the analysis models of Examples 22 to 23 in which the thicknesses of the reinforcing members are different from each other are shown in FIG. 48, and the absorbed energy in the analysis models of Examples 22 to 23 is shown in FIG. As shown in FIGS. 48 and 49, the maximum load and absorbed energy of the T-shaped joint structure according to the present invention are increased compared to the conventional T-shaped joint structure in which the reinforcing member is not provided.

When the relationship between the impactor displacement and the reaction force received by the impactor in this simulation was evaluated, the reaction force was large at the stage where the impactor displacement was small, that is, at the initial stage of deformation of the T-shaped joint structure. Therefore, it is thought that the out-of-plane deformation of the vertical wall portion of the side sill was suppressed at the initial stage of deformation, thereby increasing the reaction force compared to the conventional T-joint structure and contributing to the improvement of the absorbed energy. Therefore, according to the T-shaped joint structure according to the present invention, sufficient impact resistance can be ensured.

Summarizing the results of the above deformation simulation and collision simulation, it was shown that the T-shaped joint structure according to the present invention can achieve both sufficient bending rigidity and impact resistance and light weight.

The reinforcing member of the analysis model of Example 21 is a laminate of a CFRP layer having a fiber direction of 45 °, a CFRP layer having a −45 ° direction, a CFRP layer having a 90 ° direction, and a CFRP layer having a 0 ° direction. This is a member composed of four layers of CFRP. In the above-described collision simulation, the deformation progresses locally in various directions in the portion where the impactor collides with the side sill. However, in the analysis model of Example 21, there are a plurality of CFRP layers having different fiber directions. By doing so, it is possible to generate a reaction force against a load in a plurality of directions as well as a load in one direction. In other words, in the analysis model of Example 21, since the deformation proceeding in various directions can be suppressed, good results were obtained in any of the simulations of the collision simulations (A) to (B). Such an effect can be obtained not only when the material of the reinforcing member is CFRP but also when it is FRP. Further, when the reinforcing member is made of FRP, the fiber direction of the FRP is preferably an orientation called a so-called pseudo isotropic as in Example 21, but if there are at least two fiber directions, one fiber direction It is possible to improve the impact resistance as compared with the case of a reinforcing member made of FRP only in the fiber direction. Therefore, when the reinforcing member is a member made of FRP, the reinforcing member preferably has two or more fiber directions. The reinforcing member having two or more fiber directions may be configured, for example, by stacking FRP layers having one fiber direction in different directions, or one FRP like a so-called cloth material. You may be comprised by the cross-weaving of the linear fiber in a layer.

The present invention can be used for, for example, a joining structure of a side sill and a cross member of an automobile.

DESCRIPTION OF SYMBOLS 1 T-shaped joint structure 10 Side sill 10a Side sill hollow part 11 Side sill flat plate 12 Side sill hat-shaped member 12a Top plate part 12b Vertical wall part 12c Hat flange part 20 Cross member 20a Cross member hollow part 21 Cross member flat plate 21a Flat plate Plate portion 21b Flat plate end portion 22 Cross member hat-shaped member 22a Top plate portion 22b Vertical wall portion 22c Hat flange portion 23 Cross member contact side end portion 23a Top plate flange portion 23b Vertical wall flange portion 23c Flat plate flange portion 30 Reinforcement member 50 Conventional T-shaped joint structure F Load H Height direction L ₁ Side sill longitudinal direction L ₂ Cross member longitudinal direction S Reinforcement member slit W _a Reinforcement member width W _b Cross member top plate flange width W the width of the slit _c

Claims

A T-shaped joint structure,
A first member that is a hollow member having a first planar portion and a second planar portion connected to the first planar portion;
A second member that is a hollow member that is fixed in contact with the first flat surface portion of the first member and extends perpendicularly to the longitudinal direction of the first member;
The second member has a joint portion that is a portion joined to the second plane portion of the first member;
In a cross section perpendicular to the longitudinal direction of the first member, which is cut so as to include the hollow portion of the second member, the thickness of the second planar portion of the first member is the first thickness. The thickness of the first planar portion of the member is greater than that of the first member, and the thickness of the joint portion of the second member is greater than the thickness of the second member other than the joint portion.
In the T-shaped joint structure according to claim 1,
A reinforcing member joined so as to straddle the first member and the second member;
By joining the reinforcing member, the thickness of the second planar portion of the first member becomes thicker than the thickness of the first planar portion of the first member, and the second The thickness of the joint of the member is greater than the thickness of the second member other than the joint.
In the T-shaped joint structure according to claim 2,
The first member has a hat-shaped member,
The first plane portion is a top plate portion of the hat-shaped member,
The second flat surface portion is a vertical wall portion of the hat-shaped member.
In the T-shaped joint structure according to claim 3,
The joint portion of the second member has a flange portion extending in the longitudinal direction of the second member;
The flange portion of the second member is joined to the vertical wall portion of the first member,
The reinforcing member is joined so as to cover the flange portion of the second member.
In the T-shaped joint structure according to claim 4,
The hollow portion of the second member is formed of a hat-shaped member and a flat plate joined to the hat-shaped member,
The flange portion of the second member is formed on a flat plate of the second member.
In the T-shaped joint structure according to claim 4 or 5,
The width W a of the reinforcing member and the width W b of the joining region between the vertical wall portion of the first member and the flange portion of the second member satisfy W b ≦ 2W a .
In the T-shaped joint structure according to any one of claims 2 to 6,
The reinforcing member is a member made of at least one of FRP, an aluminum alloy, a magnesium alloy, and a steel material.
In the T-shaped joint structure according to any one of claims 2 to 7,
The reinforcing member is a member made of FRP having two or more fiber directions.
In the T-shaped joint structure according to claim 7 or 8,
The FRP is at least one of CFRP and GFRP.
In the T-shaped joint structure according to any one of claims 1 to 9,
The first member is an automobile side sill, and the second member is an automobile floor cross member.
In the T-shaped joint structure according to any one of claims 1 to 9,
The first member is an automobile roof side rail, and the second member is an automobile roof cross member.