Vehicle reinforcement

Abstract

To disclose a technique for increasing strength of a vehicular reinforcement having a two-stage groove structure as compared with a vehicular reinforcement having a one-stage groove structure, while suppressing bulkiness.SOLUTION: A vehicular reinforcement 10 includes: a reinforcement body 30 which extends by forming a cross sectional shape in which a second square groove section 21 is caved from a bottom side section 12 of a first square groove section 11; and an expansion regulation member 40 which regulates expansion of a pair of side sections 13 of the first square groove section 11. When a plate thickness of the reinforcement body 30 is t, a width of the bottom side section 12 of the first square groove section 11 is W1, a width of a bottom side section 22 of the second square groove section 21 is W2, a depth of a groove section of a total of the first and second square groove sections 11 and 21 is H1, and a depth of the second square groove section 21 is H2, t / W1=Rt, W2 / W1=Rw, H2 / H1=Rh, 0.008≤Rt, 0.33≤Rw≤0.9, and 0.1≤Rh≤0.5 are satisfied.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a reinforcement for a vehicle. [Background technology]

[0002] Conventionally, a vehicle reinforcement having a square groove structure has been known in which an additional square groove portion is provided on the bottom surface thereof to increase strength, resulting in a two-stage groove structure. Also, a vehicle reinforcement having such a two-stage groove structure has been developed that includes a member that restricts the expansion between a pair of groove side walls (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-294174 A (Fig. 2, [paragraph 0014]) Summary of the Invention [Problem to be solved by the invention]

[0004] However, if an additional square groove portion is simply provided in a vehicle reinforcement with a single-stage groove structure to make it a two-stage groove structure, the additional square groove portion will be bulky. Therefore, this application discloses a technology that makes it possible to increase the strength of a vehicle reinforcement with a two-stage groove structure while suppressing its bulkiness compared to a vehicle reinforcement with a single-stage groove structure. [Means for solving the problem]

[0005] This disclosure First aspect of the inventionis a vehicle reinforcement having a reinforcement body extending from the bottom of a first angular groove portion with a cross-sectional shape in which a second angular groove portion is recessed, and an expansion restriction member that restricts the expansion of a pair of side edges of the first angular groove portion, wherein the plate thickness of the reinforcement body is t, the width of the bottom edge of the first angular groove portion is W1, the width of the bottom edge of the second angular groove portion is W2, the depth of the groove portion formed by combining the first and second angular groove portions is H1, and the depth of the second angular groove portion is H2, t / W1=Rt W2 / W1=Rw H2 / H1=Rh 0.008≦Rt 0.33≦Rw≦0.9 0.25≦Rh≦0.33 It is a reinforcement for vehicles. [Effects of the Invention]

[0006] The above conditional formula is obtained from the experimental results of the CAE analysis described later, and is a conditional formula for increasing the buckling strength of a vehicle reinforcement with a two-stage groove structure while reducing its bulk compared to a vehicle reinforcement with a single-stage groove structure. The vehicle reinforcement of the present disclosure satisfies the above conditional formula, and therefore can increase its strength while reducing its bulk compared to a vehicle reinforcement with a single-stage groove structure. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a vehicle according to an embodiment of the present disclosure; [Figure 2] FIG. 1 is a perspective view of a vehicle reinforcement according to an embodiment of the present invention; [Figure 3] Cross-sectional view of vehicle reinforcement [Figure 4] Conceptual diagram of simulation experiment using CAE analysis [Figure 5] Graph 1 of experimental results from CAE analysis [Figure 6] Graph 2 of experimental results from CAE analysis [Figure 7] Graph 3 of experimental results from CAE analysis [Figure 8]Graph 4 of experimental results from CAE analysis [Figure 9] Graphs 5-6 of experimental results from CAE analysis DETAILED DESCRIPTION OF THE INVENTION

[0008] <Embodiment> A vehicle reinforcement 10 according to one embodiment of the present disclosure will be described below with reference to Figures 1 to 3. As shown in Figure 1, the vehicle reinforcement 10 of this embodiment is disposed between, for example, a pair of roof side rails 91 of a vehicle 90.

[0009] As shown in Fig. 2, the vehicle reinforcement 10 includes a reinforcement body 30 and an expansion restriction member 40. The reinforcement body 30 is, for example, a pressed product of sheet metal, and as shown in Fig. 3, has a cross-sectional shape that has a first angular groove portion 11, a second angular groove portion 21 recessed from a bottom portion 12 of the first angular groove portion 11, and a pair of flange portions 14 protruding outward from a pair of side portions 13 of the first angular groove portion 11, and extends in the vehicle width direction of the vehicle 90. In addition, the reinforcement body 30 is slightly curved overall so that the center portion is positioned slightly higher than both longitudinal end portions.

[0010] The reinforcement body 30 has a structure that satisfies the following conditional formula, when the plate thickness is t as shown in Figure 3, the width of the bottom edge 12 of the first corner groove portion 11 is W1, the width of the bottom edge 22 of the second corner groove portion 21 is W2, the depth of the groove portion consisting of the first and second corner groove portions 11, 21 combined is H1, and the depth of the second corner groove portion 21 is H2.

[0011] t / W1=Rt W2 / W1=Rw H2 / H1=Rh 0.008≦Rt 0.33≦Rw≦0.9 0.1≦Rh≦0.5

[0012] In addition, both end portions of the reinforcement body 30 are overlapped from above and fixed to a pair of connecting plates (not shown) that protrude toward each other from the pair of roof side rails 91. As a result, both end portions of the reinforcement body 30 are substantially rotatably supported by the pair of roof side rails 91.

[0013] The expansion restricting member 40 is, for example, a pressed metal product, and has a strip shape that is approximately the same width as the reinforcement body 30 but shorter and thinner than the reinforcement body 30. Furthermore, through holes 40A for reducing weight are formed in the center of the width direction at multiple locations in the longitudinal direction of the expansion restricting member 40. The expansion restricting member 40 is overlapped by a pair of flanges 14 and welded or fastened to a portion midway in the longitudinal direction, and is inserted across the groove opening of the first angular groove portion 11.

[0014] As shown in Fig. 3, each corner of the first and second angular groove portions 11, 21 is chamfered in an arc shape, and the radius r of the inner arc surface of each corner (hereinafter referred to as "chamfer radius r") is, for example, about 6 to 10 mm. Furthermore, the pair of side edges 13 of the first angular groove portion 11 and the pair of side edges 23 of the second angular groove portion 21 open away from each other from their parallel positions, and the opening angle θ between them is, for example, about 4 to 13°. Furthermore, the tensile strength of the material constituting the vehicle reinforcement 10 is preferably 980 MPa to 2 GPa.

[0015] This completes the description of the structure of the vehicle reinforcement 10 of this embodiment. Next, the effects of this vehicle reinforcement 10 will be described. As described above, the vehicle reinforcement 10 of this embodiment has a reinforcement body 30 that extends from the bottom edge 12 of the first angular groove portion 11 with a cross-sectional shape in which the second angular groove portion 21 is recessed. In other words, the vehicle reinforcement 10 of this embodiment has a two-stage groove structure. In addition, it is provided with an expansion restriction member 40 that spans the groove opening of the first angular groove portion 11 and restricts the expansion of a pair of side edge portions 13 of the first angular groove portion 11.

[0016] Here, the vehicle reinforcement 10 may be subjected to a load in a direction in which the pair of roof side rails 91 approach each other. Such a load acts as a buckling load that presses the vehicle reinforcement 10 in the longitudinal direction. In contrast, the vehicle reinforcement 10 of this embodiment has a structure that satisfies the above conditional formula, thereby making it possible to increase its strength.

[0017] That is, the above-mentioned conditional formula was obtained through a simulation experiment using CAE analysis, which will be described later. In the experiment, CAD data was created for multiple models of a two-stage groove structure in which a vehicle reinforcement with a single-stage groove structure is divided into two stages in the depth direction and width direction and has first and second angular groove portions 11, 21. Then, from among the multiple models, the above-mentioned conditional formula was identified as a condition for obtaining a model with a buckling strength greater than that of the vehicle reinforcement with a single-stage groove structure on which the multiple models are based. That is, the above-mentioned conditional formula is a conditional formula for increasing the buckling strength while reducing the bulk compared to a vehicle reinforcement with a single-stage groove structure. And, since the vehicle reinforcement with a two-stage groove structure of the present disclosure satisfies the above-mentioned conditional formula, it is possible to increase the strength while reducing the bulk compared to a vehicle reinforcement with a single-stage groove structure.

[0018] <Example> Simulation experiments were conducted using CAE analysis to find the conditional formula for increasing the buckling strength of a vehicle reinforcement with a two-stage groove structure while reducing its bulk compared to a vehicle reinforcement with a single-stage groove structure.

[0019] (1) Experimental method [CAD data creation] (a1) CAD data is created for 69 types of vehicle reinforcement models 1 to 69, each having a uniform cross-sectional shape throughout the entire longitudinal direction and a total length L of 1000 mm. These models 1 to 69 have the values ​​of Rt, Rw, and Rh described in the first embodiment shown in Table 1. In addition, the leg angle θ is standardized to 7°, the chamfer radius r to 6 mm, and the width L1 of the flange portion 14 to 27 mm. Furthermore, the tensile strength of the material constituting models 1 to 69 is standardized to 1470 MPa.

[0020] [Table 1]

[0021] In the following description, the components of models 1 to 69 will be described with the same names and reference numerals as the components of the vehicle reinforcement 10 described in the first embodiment.

[0022] Models 1, 26, and 47, where Rh=Rw=0, have a single-stage groove structure, while the other models 2 to 25, 27 to 46, and 48 to 69 are models in which the single-stage structure of models 1, 26, and 47 is divided into two stages in the depth and width directions, resulting in a two-stage groove structure having first and second angular groove portions 11 and 21.

[0023] In detail, Models 1 to 25 have a constant H1 of 30 mm and W1 of 75 mm, with only the values ​​of H2 and W2 changed, with Model 1 having a single-stage groove structure, and Models 2 to 25 have a double-stage groove structure obtained by dividing Model 1 into two stages in the depth and width directions. Similarly, Models 26 to 46 have a constant H1 of 30 mm and W1 of 110 mm, with only the values ​​of H2 and W2 changed, with Model 26 having a single-stage groove structure, and Models 27 to 46 are double-stage groove models based on Model 26. Models 47 to 69 have a constant H1 of 30 mm and W1 of 125 mm, with only the values ​​of H2 and W2 changed, with Model 47 having a single-stage groove structure, and Models 48 to 69 are double-stage groove models based on Model 47.

[0024] Furthermore, the buckling strength of the expansion restricting member 40 alone is set to a value that is negligible compared to the buckling strength of the entire vehicle reinforcement 10.

[0025] (a2) In order to examine the lower limit value of Rt in detail, CAD data of a model 62-1, which is the same as the model 62 except that Rt is 0.008, is created.

[0026] (a3) In order to investigate the upper limit value of Rw in detail, CAD data is created for model 45-1, which is the same as model 45 except that Rw is 0.4, model 45-2, which is the same as model 45 except that Rw is 0.7, model 45-3, which is the same as model 45 except that Rw is 0.8, and model 45-4, which is the same as model 45 except that Rw is 0.9.

[0027] (a4) In order to investigate the influence of differences in the flange portions 14, CAD data is created for models 39-1 and 39-2 in which the width L1 of a pair of flange portions 14 of model 39 is changed. Specifically, the width L1 of the flange portions 14 of model 39 is 27 [mm], the width L1 of the flange portions 14 of model 39-1 is 54 [mm], and the width L1 of the flange portions 14 of model 39-2 is 81 [mm].

[0028] (a5) To investigate the effect of differences in chamfer radius r, CAD data is created for models 39-3 and 39-4 in which the chamfer radius r of model 39 is changed. Specifically, the chamfer radius r of model 39 is 6 [mm], the chamfer radius r of model 39-3 is 8 [mm], and the chamfer radius r of model 39-4 is 10 [mm].

[0029] (a6) In order to investigate the influence of differences in the leg angle θ of the pair of side edge portions 13 and the pair of side edge portions 23, CAD data is created for models 39-5, 39-6, and 39-7 in which the leg angle θ of model 39 is changed. Specifically, the leg angle θ of model 39 is 7°, the leg angle θ of model 39-5 is 4°, the leg angle θ of model 39-6 is 10°, and the leg angle θ of model 39-7 is 13°.

[0030] [CAE analysis] (b1) By CAE analysis, the buckling load F immediately before buckling when applied to each of the above-mentioned models is determined as the limit load Fmax [kN]. Specifically, as shown in Fig. 4, one end of each model is fixed by a jig 50, while the other end is held by another jig 50 so as to be rotatable about a rotation axis extending in the width direction, and the limit load Fmax is determined when the buckling load F is applied in a direction that brings the two jigs 50 closer together. Then, the limit load ratio Rf, which is the ratio of the limit load Fmax of each model to the limit load Fmax of Models 1, 26, and 47, which are the original single-step groove structures, is determined and summarized in Table 1. More specifically, the Rf of models 1 to 25 is calculated by dividing their respective limit loads Fmax by the limit load Fmax of model 1, the Rf of models 26 to 46 is calculated by dividing their respective limit loads Fmax by the limit load Fmax of model 26, and the Rf of models 47 to 69 is calculated by dividing their respective limit loads Fmax by the limit load Fmax of model 47. The same applies to models 39-1 to 7, 45-1 to 4, and model 62-1. In other words, models with Rf greater than "1" can be said to be models with a two-stage groove structure that have achieved the reinforcing effect of providing the second angular groove portion 21 compared to models with a single-stage groove structure.

[0031] (b2) Models 1 to 69 are divided into first to third groups with a common Rt, and for each group within each of the first to third groups with a common Rw, graph 1 in Figure 5, graph 2 in Figure 6, and graph 3 in Figure 7 are created, which show the change in limit load Fmax with respect to the change in Rh.

[0032] (b3) Graph 4 in FIG. 8 is created, which shows the change in limit load Fmax with respect to the change in Rw for models 30, 35, 40, 45, and 45-1 to 4, which have common values ​​other than Rw.

[0033] (b4) Graph 5 in FIG. 9 is created, which shows the change in the limit load Fmax with respect to the change in the width L1 of the flange 14 of the models 39, 39-1, and 39-2.

[0034] (b5) Graph 6 in Figure 9 is created, which shows the change in the critical load Fmax with respect to the change in the chamfer radius r for Models 39, 39-3, and 39-4.

[0035] (b6) Graph 7 in Figure 9 is created, which shows the change in limit load Fmax with respect to the change in leg angle θ for models 39, 39-5, 39-6, and 39-7. (2) Experimental results Comparing Graphs 1 to 3, it can be seen that the reinforcing effect of the second corner groove portion 21 decreases as Rt decreases. This tendency is presumably due to the fact that the thinner the wall, the more easily the bottom edges 12, 22 and side edges 13, 23 of the first and second corner groove portions 11, 21 deform. However, the lower limit of Rt required to obtain the reinforcing effect of the second corner groove portion 21 is unclear from Graphs 1 to 3 alone. In contrast, even in Model 62-1, which was created to investigate the lower limit of Rt in detail and has an Rt of 0.008, the reinforcing effect of the second corner groove portion 21 is obtained, so the lower limit is unclear. However, it can be said that the condition for Rt required to obtain the reinforcing effect of the second corner groove portion 21 is at least 0.008≦Rt.

[0036] Furthermore, it can be seen from graphs 1 to 3 that if Rh is outside the range of 0.1≦Rh≦0.5, it is not possible to obtain the reinforcing effect of providing the second corner groove portion 21. From this, it can be said that the condition for Rh to obtain the reinforcing effect of providing the second corner groove portion 21 is 0.1≦Rh≦0.5.

[0037] Furthermore, it can be seen from Graphs 1 to 3 that when Rw becomes smaller than the lower limit, the reinforcing effect of providing the second square groove portion 21 decreases accordingly, or the strength is lower than that of the model with a single-stage groove structure. From Graphs 1 to 3, it can be said that the condition for Rw to obtain the reinforcing effect of providing the second square groove portion 21 is at least 0.33≦Rw.

[0038] Furthermore, since Rw=1 results in the same cross-sectional shape as Rw=0, it is estimated that as Rw increases beyond its upper limit, the reinforcing effect of providing the second square groove portion 21 will decrease accordingly, or the strength will be lower than that of a single-step groove structure model. The upper limit of Rw cannot be obtained from Graphs 1 to 3, but Graph 4, which was created to examine the upper limit of Rw in detail, shows that the reinforcing effect of providing the second square groove portion 21 can be obtained even when Rw is 0.9. Therefore, it can be said from Graphs 1 to 4 that the Rw condition for obtaining the reinforcing effect of providing the second square groove portion 21 is 0.33≦Rw≦0.9.

[0039] Furthermore, from graphs 5, 6, and 7, it can be seen that the differences in limit strength due to differences in width L1 of the flange portion 14, differences in chamfer radius r, and differences in leg opening angle θ are sufficiently smaller than the differences in limit strength due to differences in Rh, Rw, and Rt.

[0040] From the above, it can be said that by making the vehicle reinforcement have a two-stage groove structure that satisfies the following {first group of conditional expressions}, it is possible to increase the strength without increasing the overall length and width of the cross-sectional shape (i.e., without increasing the bulk) compared to a vehicle reinforcement with a single-stage groove structure.

[0041] {First conditional expression group} 0.008≦Rt 0.33≦Rw≦0.9 0.1≦Rh≦0.5

[0042] Also, according to graphs 1 to 3, in order to increase the strength of a vehicle reinforcement having a single-step groove structure without increasing the overall length and width of the cross-sectional shape, it can be said that the following {second group of conditional formulas} is more preferable.

[0043] {Second conditional expression group} 0.012≦Rt 0.33≦Rw≦0.62 0.2≦Rh≦0.35

[0044] Furthermore, by further narrowing down Rh in the {first group of conditional formulas} to the range of the following conditional formula, the reinforcing effect of providing the second angular groove portion 21 can be said to be increased. 0.2≦Rh≦0.4

[0045] Moreover, from the difference in the shapes of graphs 1, 2, and 3, it can be said that Rt is preferably greater than 0.012, and more preferably 0.013 or greater. Furthermore, from graphs 1 and 2, it can be estimated that the range of Rh in which Rt is 0.013 or greater and the reinforcing effect of the second angular groove portion 21 is obtained is 0.15≦Rh≦0.4. In other words, it can be said that the reinforcing effect of providing the second angular groove portion 21 is increased by further narrowing down Rh and Rt in the {first group of conditional formulas} to the range of the following conditional formulas.

[0046] 0.013≦Rt 0.15≦Rh≦0.4

[0047] Furthermore, according to Graph 4, by further narrowing down Rw in the {first group of conditional formulas} to the range of the following conditional formula, the reinforcing effect of providing the second angular groove portion 21 can be increased.

[0048] 0.4≦Rw≦0.8

[0049] <Modification> (1) In the above embodiment, the expansion restricting member 40 of the vehicle reinforcement 10 is plate-shaped and extends across the groove opening of the first square groove portion 11. However, it need not be plate-shaped and may be, for example, rod-shaped or wire-shaped. Furthermore, in the above embodiment, the expansion restricting member 40 is plate-shaped and thinner than the reinforcement body 30. However, it may be plate-shaped and have the same thickness as the reinforcement body 30 or a thickness thicker than the reinforcement body 30. Furthermore, the expansion restricting member 40 does not need to extend across the groove opening of the first square groove portion 11. For example, it may be a rib that is received in the first square groove portion 11 and welded to a pair of side edges 13 and a bottom edge 12. Furthermore, a portion of the vehicle body 90 may be used as the expansion restricting member 40.

[0050] (2) In the vehicle reinforcement 10 of the above embodiment, a pair of flange portions 14 protrude outward from a pair of side edge portions 13, but a pair of flange portions 14 may also protrude inward from a pair of side edge portions 13 approaching each other, and an expansion control member 40 may be placed on top of them.

[0051] (3) In the above embodiment, the vehicle reinforcement 10 is disposed on the ceiling of the vehicle 90 and between the pair of roof side rails 91, but it may be disposed somewhere other than the ceiling. Specifically, the vehicle reinforcement 10 may be used, for example, as a floor cross member or door reinforcement of the vehicle 90.

[0052] (4) Although one end of the vehicle reinforcement 10 is supported so as to be rotatable, for example, both ends may be fixed so as not to be rotatable.

[0053] <Additional Notes> The following describes the features extracted from the above embodiment, while indicating the effects, etc., as necessary. Note that, for ease of understanding, the reference symbols of the corresponding components in the above embodiment are shown in parentheses below, but these features are not limited to the components with the reference symbols shown in parentheses.

[0054] [Feature 1] A vehicle reinforcement (10) having a reinforcement body (30) extending from a bottom edge (12) of a first angular groove portion (11) with a cross-sectional shape in which a second angular groove portion (21) is recessed, and an expansion restriction member (40) that restricts the expansion of a pair of side edge portions (13) of the first angular groove portion (11), wherein the plate thickness of the reinforcement body (30) is t, the width of the bottom edge portion (12) of the first angular groove portion (11) is W1, the width of the bottom edge portion (22) of the second angular groove portion (21) is W2, the depth of the groove formed by combining the first and second angular groove portions (11, 21) is H1, and the depth of the second angular groove portion (21) is H2, t / W1=Rt W2 / W1=Rw H2 / H1=Rh 0.008≦Rt 0.33≦Rw≦0.9 0.1≦Rh≦0.5 Vehicle reinforcement (10).

[0055] [Feature 2] The vehicle reinforcement (10) according to Feature 1, wherein 0.2≦Rh≦0.4.

[0056] [Feature 3] 0.013≦Rt 0.15≦Rh≦0.4 The vehicle reinforcement (10) according to feature 1.

[0057] [Feature 4] Feature 1. The vehicle reinforcement (10) according to Feature 1, wherein Rw is 0.4≦Rw≦0.8.

[0058] [Feature 5] A vehicle reinforcement (10) according to any one of features 1 to 4, wherein a pair of flange portions (14) are provided that are bent outward or inward and extend from a pair of side edge portions (13) of the first angular groove portion (11), and the expansion control member (40) is in the form of a plate that is overlapped on and welded or fastened to the pair of flange portions (14).

[0059] [Feature 6] A vehicle reinforcement (10) according to any one of features 1 to 5, which has fixing portions (19) for a pair of roof side rails (91) of a vehicle (90) at both longitudinal ends of the reinforcement body (30).

[0060] [Feature 7] A vehicle (90) having the vehicle reinforcement (10) according to any one of the features 1 to 6.

[0061] Although the present specification and drawings disclose specific examples of the technology included in the scope of the claims, the technology described in the claims is not limited to these specific examples, but also includes various modifications and variations of the specific examples, and also includes parts of the specific examples taken out alone. [Explanation of symbols]

[0062] 10 Vehicle Reinforcement 11 First angular groove 21 Second corner groove 12,22 bottom 13,23 Side part 14 Tsuba 19 Fixed part 30 Reinforce main body 40 Spread control member 90 Body

Claims

1. A reinforcement body for a vehicle having a cross-sectional shape of a two-step groove structure in which a second corner groove portion is recessed from a bottom side of a first corner groove portion, and an expansion restriction member that restricts the expansion of a pair of side sides of the first corner groove portion, In order to increase the strength compared to the single-stage groove structure with the same height and width as the two-stage groove structure, Let the plate thickness of the reinforcement body be t, the width of the bottom of the first corner groove portion be W1, the width of the bottom of the second corner groove portion be W2, the depth of the groove portion combining the first and second corner groove portions be H1, and the depth of the second corner groove portion be H2. t / W1=Rt W2 / W1=Rw H2 / H1=Rh 0.008≦Rt 0.33≦Rw≦0.9 0.25≦Rh≦0.33 This is a reinforcement for vehicles.

2. 0.013≦Rt 2. The reinforcement for a vehicle according to claim 1, wherein:

3. The vehicle reinforcement according to claim 1, wherein 0.4≦Rw≦0.

8.

4. a pair of flanges are provided that are bent outward or inward and project from a pair of side edges of the first groove; The vehicle reinforcement according to any one of claims 1 to 3, wherein the expansion restricting member is in the form of a plate that is overlapped with the pair of flange portions and welded or fastened to the pair of flange portions.

5. The vehicle reinforcement according to any one of claims 1 to 3, wherein the reinforcement body is provided at both longitudinal ends with fixing portions for fixing to a pair of roof side rails of the vehicle.

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