JP2008230453A - Center pillar structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a center pillar structure capable of being easily manufactured and increasing deformation yield strength relative to side surface collision load without excessively increasing weight. <P>SOLUTION: The structure of the center pillar structure 1 for an automobile is provided with an outer frame member 4; an inner frame member 5; and a reinforcement frame member 6 arranged between the outer frame member 4 and the inner frame member 5. The reinforcement frame member 6 has a projection part 60c bent/formed on a vertical cross section in a longitudinal direction so as to be projected toward a side of the inner frame member 5 in an intermediate part in a vehicle longitudinal direction; and an end reinforcement wall part 62a extending toward the inner frame member 5 along the outer frame member 4 at both ends in the vehicle longitudinal direction. Further, the reinforcement frame member 6 is fixed to the outer frame member 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a center pillar structure used in an automobile.

  The center pillar of an automobile is a structural member that is installed vertically between a side rail of a roof panel and a side sill of a floor panel between a front door and a rear door on the side of the automobile. Conventionally, a center pillar structure described in Patent Document 1 is known as a center pillar structure used in an automobile. The center pillar structure includes an outer member 10, an inner member 11, and a reinforcing member 12 disposed in an internal space between them. Then, both end portions 12A and 12B of the reinforcing member 12 in the vehicle front-rear direction are coupled in a state of being sandwiched between end portions of the outer member 10 and the inner member 11. In addition, wall portions 20 and 21 that extend in the vehicle interior and exterior direction beyond positions corresponding to both end portions 12A and 12B of the reinforcement member 12 are formed in the middle portion of the reinforcement member 12 in the vehicle longitudinal direction. By attaching the reinforcing member 12 in this manner, the effective section modulus of the reinforcing member with respect to the side collision load is increased, so that the deformation resistance against the side collision load of the center pillar can be increased.

JP 2004-314845 A

  However, the center pillar structure described in Patent Document 1 requires that both ends of the reinforcing member be coupled to both the outer member and the inner member. In this case, since it is necessary to perform welding in a state where the flange portion of the outer member, the end portion of the reinforcing member, and the flange portion of the inner member are overlapped, workability in manufacturing the center pillar becomes a problem.

  An object of the present invention is to provide a center pillar structure that can be easily manufactured and can increase the deformation resistance against a side collision load without excessively increasing the weight in view of the above circumstances. To do.

Means and effects for solving the problems

  The center pillar structure according to the present invention relates to a center pillar structure used in an automobile. The center pillar structure according to the present invention has the following features in order to achieve the above object. That is, the center pillar structure of the present invention includes the following features alone or in combination.

  In order to achieve the above object, the first feature of the center pillar structure according to the present invention includes an outer skeleton member, an inner skeleton member coupled to the outer skeleton member at both ends in the vehicle longitudinal direction, and the outer skeleton member. And an inner space formed between the inner skeleton member and a reinforcing skeleton member disposed at least at a part on the upper end side in the longitudinal direction of the inner space. The reinforcing skeleton member includes, in a longitudinal vertical cross section, a projecting portion formed by bending so as to project toward the inner skeleton member at an intermediate portion in the vehicle longitudinal direction, and both ends in the vehicle longitudinal direction And an end reinforcing wall portion extending toward the inner skeleton member along the outer skeleton member, and the reinforcing skeleton member is fixed to the outer skeleton member. Is Rukoto.

  According to this configuration, since the reinforcing skeleton member includes the protruding portion protruding in the vehicle width direction and the end reinforcing wall portion extending toward the inner skeleton member, the thickness of the reinforcing skeleton member is not increased. It becomes possible to increase the section modulus with respect to the side collision load. Further, both ends of the reinforcing skeleton member in the vehicle front-rear direction are formed by end reinforcing wall portions extending toward the inner skeleton member along the outer skeleton member. For example, compared to a configuration in which a flange shape or the like is formed at the end portion. The ratio of increase in section modulus with respect to weight increase is high. Therefore, it is possible to increase the deformation resistance against the side collision load while further reducing the weight of the center pillar. Further, since the reinforcing skeleton member is configured to be fixed to the outer skeleton member, it is not necessary to fix the skeleton member to the inner skeleton member, and the center pillar can be easily manufactured.

  Further, the second feature of the center pillar structure according to the present invention is that the projecting direction end of the projecting portion and the extending direction end of the end reinforcing wall portion are connected to the outer skeleton member and the end in the vehicle width direction. It is formed so as to be positioned on the outer side in the vehicle width direction than the coupling portion with the inner skeleton member.

  According to this configuration, in a state where the reinforcing skeleton member is coupled to the outer skeleton member at the time of assembling the center pillar, the reinforcing skeleton member is included in the outer skeleton member, and more than the coupling portion between the outer skeleton member and the inner skeleton member. It is possible to prevent the reinforcing skeleton member from projecting to the outside. Thereby, the outer skeleton member and the inner skeleton member can be easily combined.

  In addition, a third feature of the center pillar structure according to the present invention is that the reinforcing skeleton member is formed so that a vertical cross-sectional shape in the longitudinal direction is symmetrical with respect to a center line passing through the center in the vehicle longitudinal direction. It is that.

  According to this configuration, the side collision load is likely to act symmetrically with respect to the center line in the vehicle longitudinal direction, so that it is possible to suppress the load from acting on a part of the reinforcing skeleton member. Become. Thereby, it becomes possible to increase the deformation resistance against the side collision load without excessively increasing the weight of the center pillar.

  Further, the fourth feature of the center pillar structure according to the present invention is that the reinforcing skeleton member has a length occupied by the protruding portion and a length occupied by a portion located on one end side of the protruding portion in the vehicle longitudinal direction. And the length which the part located in the other end side from the said protrusion part occupies is formed so that it may become equal length, respectively.

  According to this configuration, the portions of the reinforcing skeleton member that extend in the vehicle width direction are evenly arranged in the vehicle front-rear direction, so that it is possible to prevent local concentration of stress due to a side collision load being applied. It becomes. Therefore, it is possible to increase the deformation resistance against the side collision load.

  Further, a fifth feature of the center pillar structure according to the present invention is that, in the reinforcing skeleton member, the protruding direction end of the protruding portion is the position of the extending direction end of the end reinforcing wall portion in the vehicle width direction. It is formed so as to be located on the inner side in the vehicle width direction.

  It has been found by the inventor that the length of the protruding portion extending in the protruding direction has a greater influence on the buckling load of the center pillar than the length of the end reinforcing wall portion. According to this configuration, since the length of the projecting portion extending in the projecting direction can be made longer than the length of the end reinforcing wall portion, an increase in the weight of the center pillar is further suppressed, and the deformation proof strength against the side collision load is reduced. Can be high.

  Further, a sixth feature of the center pillar structure according to the present invention is that the protrusion has a pair of side walls extending inward in the vehicle width direction, and the end reinforcing wall portion extends in the vehicle width direction. Is within the range of 0.7 to 0.9 times the length of the pair of side walls.

  According to this structure, it can comprise so that the weight of the center pillar of the structure provided with the desired deformation strength with respect to a side collision load may become lighter. In other words, when the center pillar is configured with a predetermined weight, the deformation resistance can be further increased.

  The seventh feature of the center pillar structure according to the present invention is that the reinforcing skeleton member is fixed to the outer skeleton member in a state where only the end reinforcing wall portion is coupled to the outer skeleton member. That is.

  According to this configuration, since the joint portion between the reinforcing skeleton member and the outer skeleton member can be concentrated only on the end reinforcing wall portion, the workability for joining is improved, and the center pillar can be easily manufactured. Become. Further, since the end reinforced wall portion extending toward the inner skeleton member is used for coupling with the outer skeleton member, it is not necessary to form a flange or the like on the end reinforcing wall portion of the reinforcing skeleton member. Therefore, it is possible to increase the deformation resistance against the side collision load while reducing the weight of the center pillar. In addition, since the fall of the deformation | transformation yield strength with respect to a side collision load by not couple | bonding parts other than the said end reinforcement wall part with an outer side frame member is small, it is effective.

  Further, an eighth feature of the center pillar structure according to the present invention is that the protrusion has a pair of side walls extending inward in the vehicle width direction, the length of the end reinforcing wall portion in the vehicle width direction, Based on the relationship between the length in the vehicle width direction of the pair of side walls and the strength of the center pillar, which is obtained in advance through experiments or analysis, the center pillar has a desired strength and the end reinforcing wall portion in the vehicle width direction. The reinforcing skeleton member is formed so that the sum of the length of the pair and the length of the pair of side walls is minimized.

  According to this structure, it can comprise so that the weight of the center pillar of the structure provided with the desired deformation strength with respect to a side collision load may become the lightest.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic perspective view of a center pillar partly including a center pillar structure according to an embodiment of the present invention as viewed from substantially the side of a vehicle. In the present embodiment, the structure of the center pillar 1 that is installed between the roof side rail 2 and the side sill 3 at a substantially central portion in the vehicle longitudinal direction in a medium-sized automobile will be described as an example. The center pillar includes not only a pillar installed at the center in the vehicle front-rear direction but also a pillar installed at a position from the front or rear of the vehicle, and means a pillar that contributes to ensuring a certain body strength. ing.

  As shown in FIG. 1, the center pillar 1 is disposed between a front door located on the front side of the vehicle and a rear door located on the rear side of the vehicle, and is joined to a roof panel (not shown). Between the rail 2 and the side sill 3 joined to a floor panel (not shown), it is constructed up and down. Moreover, the upper end part joined to the roof side rail 2 of the center pillar 1 is formed in a substantially T shape, and the lower end part connected to the side sill 3 is formed in an inverted T shape. The center pillar 1 is formed such that its longitudinal cross-sectional shape expands from the upper end portion toward the lower end portion while maintaining a substantially similar shape.

  FIG. 2 is a schematic view of the center pillar shown in FIG. 1 as viewed from the rear of the vehicle. As shown in FIG. 2, the center pillar 1 has a shape that curves and protrudes outward in the vehicle width direction, and includes an outer reinforcement 4 (outer skeleton member) positioned on the outer side in the vehicle width direction, and the outer reinforcement. 4 and an inner reinforcement 5 (inner skeleton member) joined together. Further, a reinforcing reinforcement 6 (shown by a chain line in FIG. 2) is disposed between the outer reinforcement 4 and the inner reinforcement 5. The reinforcing reinforcement 6 extends in the longitudinal direction in the internal space between the outer reinforcement 4 and the inner reinforcement 5 so as to occupy about ¾ of the total length of the center pillar 1 on the upper end side of the center pillar 1. It is arranged over.

  3 is an S1-S1 cross-sectional view of the center pillar shown in FIG. As shown by arrows in FIG. 3, the front side of the vehicle is shown as the left side of the figure, and the outer side in the vehicle width direction is shown as the upper side of the figure. The outer reinforcement 4, the inner reinforcement 5 and the reinforcing reinforcement 6 are all members formed by sheet metal press molding.

  The outer reinforcement 4 includes flange portions 40a and 40b extending in the vehicle front-rear direction, and a bulging portion 40c that bulges outward from the flange portions 40a and 40b in the vehicle width direction is provided at an intermediate portion in the vehicle front-rear direction. Is formed. The bulging portion 40c includes a pair of side wall portions 41a and 41b and a flat surface portion 41c that is a flat portion connecting the ends of the pair of side wall portions 41a and 41b in the bulging direction.

  The inner reinforcement 5 includes flange portions 50a and 50b extending in the vehicle front-rear direction, and a bulging portion 50c that bulges inward in the vehicle width direction from the flange portions 50a and 50b is provided at an intermediate portion in the vehicle front-rear direction. Is formed. The bulging portion 50c includes a pair of side wall portions 51a and 51b and a flat surface portion 51c that is a flat portion connecting the ends of the pair of side wall portions 51a and 51b in the bulging direction. The outer reinforcement 4 and the inner reinforcement 5 are joined by welding the flange portions 40a and 50a and 40b and 50b, respectively.

  The bulging length y1 (length in the vehicle width direction) of the bulging portion 50c of the inner reinforcement 5 from the flange portions 50a and 50b is from the flange portions 40a and 40b of the bulging portion 40c of the outer reinforcement 4. The bulge length y2 is about 1/3 of the bulge length y2. Specifically, for example, the bulging length y1 of the inner reinforcement 5 is 15 mm, and the bulging length y2 of the outer reinforcement 4 is 45 mm.

  The length x1 of the plane portion 41c in the outer reinforcement 4 is set to about 85 mm, and the length x2 of the plane portion 51c of the inner reinforcement 5 is set to about 100 mm. Further, the length x3 of the outer reinforcement 4 and the inner reinforcement 5 in the vehicle front-rear direction is formed to be about 140 mm.

  The reinforcing reinforcement 6 is a structural member formed by bending a plate-like member by press molding. The reinforcing reinforcement 6 includes a front plane portion 60a and a rear plane portion 60b that are disposed substantially parallel to the plane portion 41c of the outer reinforcement. The front plane part 60a and the rear plane part 60b are formed so as to be positioned on the same plane.

  Between the front plane part 60a and the rear plane part 60b, the side of the inner reinforcement 5 is continuous with the end part on the vehicle rear side of the front plane part 60a and the end part on the vehicle front side of the rear plane part 60b. A projecting portion 60c projecting toward the surface is formed. The projecting portion 60c is a pair of central reinforcing walls extending substantially parallel to each other from the vehicle rear side end portion of the front flat surface portion 60a and the vehicle front side end portion of the rear flat surface portion 60b toward the inner reinforcement 5 side. Parts 61a and 61b, and a protruding flat part 61c that is a flat part connecting the ends in the extending direction of the pair of central reinforcing wall parts 61a and 61b. The protruding flat part 61c is formed to be substantially parallel to the front flat part 60a and the rear flat part 60b. The projecting flat surface portion 61c, the front flat surface portion 60a, and the rear flat surface portion 60b are formed to have substantially the same length, and the central reinforcing wall portions 61a and 61b are made of reinforcing reinforcement. 6 is arranged at a position where the length in the vehicle front-rear direction is approximately divided into three.

  In addition, an end reinforcing wall portion 62a extending toward the inner reinforcement 5 along the side wall portion 41a of the outer reinforcement 4 is formed continuously to the end portion of the front plane portion 60a on the vehicle front side. Similarly, an end reinforcing wall 62b extending toward the inner reinforcement 5 along the side wall 41b of the outer reinforcement 4 is formed continuously to the rear rear end of the rear plane portion 60b. . The end reinforcing wall portions 62a and 62b are formed so as to extend with a predetermined inclination with respect to the vehicle width direction so that the distance between the end reinforcing wall portions 62a and 62b increases toward the inner reinforcement 5 side. .

  In the reinforcing reinforcement 6 formed as described above, the end reinforcing wall portions 62a and 62b are spot welded to the side wall portions 41a and 41b of the outer reinforcement 4 (the welding position is indicated by W1 in FIG. 10). The front plane portion 60a and the rear plane portion 60b are spot-welded and fixed to the plane portion 41c of the outer reinforcement 4 (in FIG. 10, the welding position is indicated by W2).

  As shown in FIG. 3, the reinforcing reinforcement 6 is formed so that the vertical cross-sectional shape in the longitudinal direction is symmetrical with respect to the center line L <b> 2 passing through the center in the vehicle longitudinal direction. In the state where the reinforcing reinforcement 6 is fixed to the outer reinforcement 4, the end reinforcement walls 62 a and 62 b of the reinforcing reinforcement 6 have end portions on the inner reinforcement 5 side that are flanges of the outer reinforcement 4. It is located on the outer side in the vehicle width direction than a line L1 (hereinafter referred to as a flange line L1) connecting the portions 4a and 4b. Further, the protruding flat portion 61 c is also formed so as to be located on the outer side in the vehicle width direction with respect to the flange line L <b> 1 of the outer reinforcement 4.

  Next, FEM analysis of the three-point bending deformation of the center pillar 1 having the center pillar structure according to the present embodiment is performed, and the maximum load F (hereinafter referred to as the maximum load) that can be supported by the center pillar 1 during the three-point bending under the following conditions. The result of calculating the load F) will be described. As an FEM analysis model, a pillar model having the same cross-sectional shape in the longitudinal direction and curved so as to protrude to the outside of the vehicle (outer reinforcement 4 side) with a predetermined radius of curvature (1310 mm) in the longitudinal direction (see FIG. 15). ), The inner reinforcement 5 side is supported by a cylindrical model (diameter 60 mm) extending in the longitudinal direction of the vehicle at two points with a predetermined interval (860 mm) in the longitudinal direction, while the outer reinforcement 4 side is An analysis was performed in which the center of the two support positions was energized at a predetermined speed (10 m / sec) using a cylindrical model (diameter 300 mm) extending in the vehicle longitudinal direction.

  In addition, the case where the reinforcing reinforcement is 1.8 mm thick and 2.3 mm thick is analyzed, and the relationship between the maximum load F applied to the center pillar during bending deformation and the sectional weight of the center pillar is calculated. did. The analysis was performed with the outer reinforcement 4 and the inner reinforcement 5 fixed at a thickness of 1.8 mm. Here, the cross-sectional weight is a weight per 1 m of the center pillar, and in this analysis, the cross-sectional weight varies due to a change in the plate thickness.

  In addition, the same analysis was performed also about the center pillar structure which has a cross-sectional shape shown in FIGS. 4-8 as a comparative example. FIG. 4 is a diagram illustrating a center pillar structure according to Comparative Example 1. This center pillar structure is different from the center pillar structure according to the present embodiment in that there is no protrusion 60c at the center in the vehicle front-rear direction in the reinforcing reinforcement 6. FIG. 5 is a diagram illustrating a center pillar structure according to Comparative Example 2. In this center pillar structure, the protruding portion in the center pillar structure according to the present embodiment protrudes outward in the vehicle width direction. FIG. 6 is a diagram illustrating a center pillar structure according to Comparative Example 3. This center pillar structure is formed so that the shoulder portion 6a of the reinforcing reinforcement in the center pillar structure according to the comparative example 1 has a gentle slope with respect to the flat surface portion 41c of the outer reinforcement 4. . FIG. 7 is a view showing a center pillar structure according to Comparative Example 4. The center pillar structure is formed by a flange portion 6b formed in a reinforcing reinforcement, and the flange portion 6b is sandwiched between an outer reinforcement 4 and an inner reinforcement 5 and welded. And the protrusion part 6c of the vehicle front-back direction center part is extended until it contact | abuts to the plane part 51c of the inner reinforcement 5 exceeding the flange line L1. FIG. 8 is a view showing a center pillar structure according to Comparative Example 5. This center pillar structure is configured such that the shoulder 6d in the center pillar structure according to Comparative Example 4 is close to the inner reinforcement 5 side.

  FIG. 9 is a diagram showing the relationship between the cross-sectional weight and the maximum load in the three-point bending analysis in the center pillars according to the embodiment and the first to fifth comparative examples obtained by the above analysis. In addition, about embodiment and Comparative Examples 1-3, the point when the plate | board thickness of the reinforcement reinforcement is 1.8 mm and 2.3 mm is plotted. In Comparative Examples 4 and 5, the results when the plate thickness is 1.8 mm are shown.

  From FIG. 9, it can be seen that, when compared with a predetermined cross-sectional weight, the center pillar structure according to the present embodiment has the largest maximum load compared to other Comparative Examples 1 to 5. In other words, by making the center pillar capable of supporting a predetermined maximum load into the shape of the center pillar according to the present embodiment, compared to the case of forming the center pillar in the shapes of other comparative examples 1 to 5. And can be formed to have a lighter weight.

  Next, the vehicle width direction length H1 (hereinafter referred to as end wall length H1) of the straight portion of the end reinforcing wall portions 62a and 62b and the vehicle width direction length H2 of the straight portion of the central reinforcing wall portions 61a and 61b. (Hereinafter, referred to as the middle wall length H2), the results of analyzing the influence of the change on the maximum load F that can be supported by the center pillar 1 will be described.

  In the center pillar structure shown in FIG. 10 (the same shape as that shown in FIG. 3), the end wall length H1 is (i) 10 mm, (ii) 25 mm, (iii) 41 mm, and the inner wall length H2 is ( 9 types of center pillar structures combined as i) 12.5 mm, (ii) 27.5 mm, and (iii) 39 mm, and the end wall length H1 is (ii) 25 mm and the middle wall length H2 is (iv) 55 A three-point bending analysis was performed on a center pillar structure with a thickness of 5 mm. FIG. 11 shows the relationship between the cross-sectional weight and the maximum load F calculated in the analysis.

  From FIG. 11, when the cross-sectional weight is in the range of about 6.5 to 8.5 kg / m, for example, when the end wall length H1 is fixed to (ii) 25 mm and the middle wall length H2 is increased (FIG. 11). In FIG. 5, it can be seen that the maximum load F increases substantially in proportion to the change in the sectional weight. Further, for example, even when the end wall length H1 is increased by fixing the middle wall length H2 to (ii) 27.5 mm (when attention is paid to the change “2” in FIG. 11), the cross section It can be seen that the maximum load F increases corresponding to the increase in weight, but the rate of increase of the maximum load F gradually decreases as the cross-sectional weight increases.

  Next, the result of analyzing the relationship between the spot welding position of the reinforcing reinforcement and the maximum load F will be described. FIG. 10 shows the position of spot welding in the analysis model. As shown in FIG. 10, the position of spot welding is approximately the center in the vehicle width direction of the contact portion between the end reinforcing wall portions 62 a and 62 b in the reinforcing reinforcement 6 and the side wall portions 41 a and 41 b in the outer reinforcement 4 ( The position indicated by W1 in FIG. 10 (hereinafter referred to as a welding position W1) and the vehicle front-rear direction at the abutting portion between the front flat portion 60a and the rear flat portion 60b of the reinforcing reinforcement 6 and the flat portion 41c of the outer reinforcement 4 A substantially central portion (a position indicated by W2 in FIG. 12, hereinafter referred to as a welding position W2) was used.

  Analysis includes (1) spot welding at both welding position W1 and welding position W2, (2) spot welding only at welding position W1, and (3) spot welding only at welding position W2. The three types were analyzed. The analysis was performed assuming that the end wall length H1 is 27 mm, the middle wall length H2 is 30 mm, and the plate thickness is 1.8 mm.

  FIG. 12 is a diagram showing the relationship between the position of spot welding and the maximum load in the three-point bending analysis. From FIG. 12, it can be seen that the maximum load F is the largest when both the welding positions W1 and W2 are spot welded. It can also be seen that the maximum load F is greater when only the welding position W1 is welded than when only the welding position W2 is welded. From this, if it is set as the structure which welded only the welding position W1, it will become possible to reduce a spot welding location, without reducing the maximum load F too much, and it will become possible to improve the manufacturing efficiency of a center pillar.

  In addition, by making the length of the end reinforcing wall portions 62a and 62b in the reinforcing reinforcement 6 10 mm or more, it becomes possible to easily perform spot welding at the welding position W1, and workability at the time of manufacturing the center pillar. Can be improved.

Next, a weight reduction design method for the center pillar having the desired maximum load F will be described. First, the result of analyzing the relationship between the end wall length H1, the intermediate wall length H2, the reinforcing reinforcement plate thickness t (hereinafter referred to as the reinforcing plate thickness t), and the maximum load F will be described. It is considered that the relationship between the maximum load F, the end wall length H1, the intermediate wall length H2, and the reinforcing plate thickness t can be appropriately expressed by the following expression (1) (a, b, c, d). Is a coefficient).
^{F = a × H1 b × H2} c × t d ··· Equation (1)
The maximum load that can be applied to the center pillar is calculated by appropriately changing the values of the end wall lengths H1 and H2 and the reinforcing plate thickness t by FEM analysis. Based on the calculation result, the formula (1) The coefficients a, b, c, and d are determined as follows.
a = 22.2423, b = 0.0396, c = 0.0432, d = 0.7434
In addition, since the power index (c = 0.0432) of the middle wall length H2 is larger than the power index (b = 0.0396) of the end wall length H1 in the formula (1), the maximum load F is given. It can be said that the influence is greater in the middle wall length H2 than in the end wall length H1.

  In FIG. 13, the graph indicated by the solid curve shows the relationship between H1 and H2 at which the maximum load F is constant, based on Expression (1) into which the coefficients a to d calculated by the above analysis are substituted. The curve shown by (i) is a curve showing the relationship between the end wall length H1 and the middle wall length H2 when the maximum load F is 45 kN, and the curve shown by (ii) is the maximum load F It is a curve which shows the relationship between the end wall length H1 and the middle wall length H2 when becomes 40 kN.

  For example, in order to obtain a center pillar in which the maximum load F that can be supported is 45 kN, the lengths of H1 and H2 are combinations of the lengths of H1 and H2 indicated by points existing on the curve (i) in FIG. It is necessary to. Here, the cross-sectional weight increases as the end reinforcing wall portions 62a and 62b become longer, and increases as the central reinforcing wall portions 61a and 61b become longer. That is, the cross-sectional weight changes in proportion to the value of H1 + H2. Therefore, the combination of H1 and H2 at the point where the value of H1 + H2 is the smallest at the point on the curve (i) is the combination of H1 and H2 with the smallest cross-sectional weight. From this, a straight line of H1 + H2 = constant (shown by a straight line C1 in FIG. 13) that touches the curve (i) is obtained, and H1 and H2 at the contact point (point d1 in FIG. 13) of the straight line and the curve of F = 45. (H1 = 23 mm, H2 = 27 mm) is adopted as the reinforcing reinforcement shape, so that the most lightweight center pillar having a maximum load of 45 kN can be designed.

  Further, for example, in order to obtain a center pillar having a maximum load of 40 kN, a straight line of H1 + H2 = constant (shown by a straight line C2 in FIG. 13) in contact with the curve (ii) is obtained and the straight line and a curve of F = 40 The combination of H1 and H2 (H1 = 6mm, H2 = 7mm) at the point of contact with (ii) (point d2 in FIG. 13) is adopted as the shape of the reinforcing reinforcement, so that it is the most lightweight with a maximum load of 40kN Designed center pillars can be designed.

  It should be noted that the end wall length H1 and the intermediate wall length H2 at the contact point between the curve indicating the combination of the end wall length H1 and the intermediate wall length H2 having the desired maximum load F, and the straight line H1 + H2 = constant. The end wall length H1 is a combination of the end wall length H1 and the intermediate wall length H2, which is a desired maximum load, and the end wall length H1 is 0. 0 of the intermediate wall length H2. By forming the center pillar so as to be within the range of 7 to 0.9 times, it is possible to remarkably exhibit the effect of reducing the weight while having the desired maximum load F. In particular, when the reinforcing reinforcement is designed so that the end wall length H1 is 0.8 times the middle wall length H2, it is preferable because the effect of weight reduction can be exhibited.

  As described above, the center pillar structure according to the present embodiment includes the outer reinforcement 4, the inner reinforcement 5 coupled to the outer reinforcement 4 at both ends in the vehicle front-rear direction, and the outer reinforcement 4. A center pillar structure for an automobile comprising an internal space formed between the inner reinforcement 5 and a reinforcing reinforcement 6 disposed at least at a part on the upper end side in the longitudinal direction of the internal space. It is. The reinforcing reinforcement 6 includes, in a longitudinally vertical cross section, a projecting portion 60c that is bent so as to project toward the inner reinforcement 5 at an intermediate portion in the vehicle longitudinal direction, and a vehicle longitudinal direction. End reinforcement wall portions 62 a and 62 b extending toward the inner reinforcement 5 along the outer reinforcement 4 at both ends, and the reinforcing reinforcement 6 is provided to the outer reinforcement 4. Is fixed.

  According to this configuration, the reinforcing reinforcement 6 includes the protruding portion 60c that protrudes in the vehicle width direction and the wall portion that extends toward the inner reinforcement 5, so that the thickness of the reinforcing reinforcement 6 is increased. Therefore, the section modulus with respect to the side collision load can be increased. Further, both ends of the reinforcing reinforcement 6 in the vehicle front-rear direction are formed by end reinforcing walls 62a and 62b extending toward the inner reinforcement 5 along the side wall 41a of the outer reinforcement 4 to the end. Compared to the configuration in which the flange shape or the like is formed at the end, the rate of increase in the section modulus with respect to the weight increase is high. Therefore, it is possible to increase the deformation resistance against the side collision load indicated by the maximum load F or the like at the time of three-point bending deformation while further reducing the weight of the center pillar 1. Further, since the reinforcing reinforcement 6 is welded and fixed to the outer reinforcement 4, welding to the inner reinforcement 5 is not required, and the center pillar 1 can be easily manufactured. Become.

  For example, as shown in FIG. 14, the reinforcing reinforcement protruding portion may be close to the vicinity of the bulging portion 50 c of the inner reinforcement 5.

  Further, the projecting flat surface portion 61c located at the projecting direction end portion of the projecting portion 60c in the reinforcing reinforcement 6 and the extending direction end portions of the end reinforcing wall portions 62a and 62b are connected to the outer rain in the vehicle width direction. It is formed so as to be positioned on the outer side in the vehicle width direction with respect to the connecting portion between the force 4 and the inner reinforcement 5.

  According to this configuration, in a state where the reinforcing reinforcement 6 is coupled to the outer reinforcement 4 when the center pillar 1 is assembled, the reinforcing reinforcement is included in the outer reinforcement 4, and the inner reinforcement 5 in the outer reinforcement 4. It is possible to prevent the reinforcing reinforcement 6 from projecting to the outside of the joint portion. The projecting portion 60c of the reinforcing reinforcement 6 does not protrude from the flange line L1 of the outer reinforcement 4 so that the outer reinforcement 4 to which the reinforcing reinforcement 6 is connected is connected to the inner reinforcement 5. At this time, the outer reinforcement 4 can be easily handled, and the assembling work can be easily performed. Further, the protrusion 60c of the reinforcing reinforcement does not come into contact with the inner reinforcement regardless of the bulging length of the bulging portion 50c of the inner reinforcement 5, and thus, for example, shapes having different bulging lengths. It can also be assembled with the inner reinforcement.

  The reinforcing reinforcement 6 is formed so that the vertical cross-sectional shape in the longitudinal direction is symmetrical with respect to the center line L2 passing through the center in the vehicle front-rear direction.

  According to this configuration, the side collision load is likely to act symmetrically with respect to the center line L2 in the vehicle front-rear direction, so that it is possible to suppress the load from acting on a part of the reinforcing reinforcement 6. It becomes possible. Thereby, it becomes possible to increase the deformation resistance against the side collision load without excessively increasing the weight of the center pillar 1.

  The reinforcing reinforcement 6 has a length occupied by the protruding portion 60c in the vehicle front-rear direction, and a length occupied by the front flat portion 60a and the end reinforcing wall portion 62a located on the vehicle front side of the protruding portion 60c. The length occupied by the rear flat surface portion 60b and the reinforcing wall portion 62b located on the vehicle rear side with respect to the projecting portion 60c is formed to be equal to each other.

  According to this configuration, since the portions extending in the vehicle width direction of the reinforcing reinforcement 6 are evenly arranged in the vehicle front-rear direction, it is possible to prevent local stress concentration due to a side collision load being applied. It becomes possible. Therefore, it is possible to increase the deformation resistance against the side collision load.

  Further, the reinforcing reinforcement 6 has a protruding flat portion 61c positioned at the protruding end portion of the protruding portion 60c, rather than the end direction end portions of the end reinforcing wall portions 62a and 62b in the vehicle width direction. It is formed so as to be located on the inner side in the vehicle width direction.

  As described above, in the equation (1) showing the relationship between the maximum load F and the H1 and H2 during the three-point bending of the center pillar 1, than the power index (b = 0.0396) of the end wall length H1, It is clear from the analysis result made by the inventor of the present invention that the power index (c = 0.0432) of the middle wall length H2 becomes larger. Accordingly, it can be said that the length of the projecting portion 60c extending in the projecting direction has a greater influence on the deformation resistance against the side collision load of the center pillar than the length of the end reinforcing wall portions 62a and 62b. For example, in a reinforcing reinforcement in which H1 and H2 have the same length, it is better to change the shape to extend H2 by the predetermined length than to change the shape to extend H1 by the predetermined length. It is clear from the equation (1) that the increase rate of the maximum load F increases. Therefore, by forming the protruding flat portion 61c so as to be located on the inner side in the vehicle width direction with respect to the position of the end portion in the extending direction of the end reinforcing wall portions 62a and 62b in the vehicle width direction, the protruding flat portion 61c is Compared with the case where the end reinforcing wall portions 62a and 62b are formed at the same position in the vehicle width direction as the end direction end portions, the increase in the weight of the center pillar is further suppressed, and the maximum load F when three-point bending is performed. It is possible to increase the deformation resistance against the side collision load indicated by.

  The projecting portion 60c has a pair of central reinforcing wall portions 61a and 61b extending inward in the vehicle width direction, and the length in which the end reinforcing wall portions 62a and 62b extend in the vehicle width direction is the pair. The central reinforcing wall portions 61a and 61b are formed so as to be within a range of 0.7 to 0.9 times the length of the extension.

  According to this structure, it can comprise so that the weight of the center pillar of the structure provided with the desired deformation strength with respect to a side collision load may become lighter. In other words, when the center pillar is configured with a predetermined weight, the deformation resistance can be further increased.

  Further, in the center pillar structure according to the present embodiment, the reinforcing reinforcement 6 is in a state where only the end reinforcing wall portions 62a and 62b are spot-welded to the side wall portions 41a and 41b of the outer reinforcement 4. It can also be set as the structure fixed to the outer reinforcement 4. FIG.

  According to this configuration, since the welded portion between the reinforcing reinforcement 6 and the outer reinforcement 4 can be concentrated only on the end reinforcing wall portions 62a and 62b, the workability for welding is improved and the center pillar 1 is improved. Manufacturing becomes possible easily. Further, since the end reinforcement wall portions 62a and 62b extending toward the inner reinforcement 5 are welded to the outer reinforcement 4, a flange or the like is formed on the end reinforcement wall portions 62a and 62b of the reinforcement reinforcement 6. There is no need to do this. Therefore, it is possible to increase the deformation resistance against the side collision load while reducing the weight of the center pillar 1. In addition, since the fall of the deformation | transformation yield strength with respect to a side collision load by not couple | bonding parts other than the said edge reinforcement wall part 62a * 62b with the outer reinforcement 4 is small, it is effective.

  Further, the length of the end reinforcing wall portions 62a and 62b in the vehicle width direction, the length of the pair of opposed central reinforcing wall portions 61a and 61b constituting the protruding portion 60c in the vehicle width direction, and the strength of the center pillar, Based on the relationship shown in the above formula (1) obtained in advance by experiment or analysis, the center pillar has a desired strength, the length of the end reinforcing wall portions 62a and 62b in the vehicle width direction, and the pair of central reinforcements. The reinforcing reinforcement 6 can be formed so that the sum of the lengths of the wall portions 61a and 61b is minimized.

  The center pillar having the configuration in which the reinforcing reinforcement 6 is formed and coupled to the outer reinforcement 4 as described above is effective because it has the desired deformation resistance against the side collision load and the most lightweight configuration. .

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

1 is a schematic perspective view of a center pillar that partially includes a center pillar structure according to an embodiment of the present invention as viewed from substantially the side of a vehicle. It is the schematic which looked at the center pillar shown in FIG. 1 from the vehicle back. FIG. 3 is an S1-S1 cross-sectional view of the center pillar shown in FIG. FIG. 5 is a cross-sectional view of a center pillar according to a first comparative example. It is sectional drawing of the center pillar which concerns on a 2nd comparative example. It is sectional drawing of the center pillar which concerns on a 3rd comparative example. It is sectional drawing of the center pillar which concerns on a 4th comparative example. It is sectional drawing of the center pillar which concerns on a 5th comparative example. It is a figure which shows the relationship between the cross-sectional weight and the maximum load in a three-point bending analysis in the center pillar which concerns on embodiment and a 1st-5th comparative example. It is a figure which shows the end wall length H1, the middle wall length H2, and the position of spot welding in FIG. In the center pillar which concerns on this embodiment, it is a figure which shows the relationship between a cross-sectional weight and the maximum load in a three-point bending analysis when end wall length H1 and middle wall length H2 are changed. It is a figure which shows the relationship between the position of spot welding, and the maximum load in a three-point bending analysis. It is a figure which shows the relationship between the length H1 of an end wall part, the length H2 of a center wall part, and cross-sectional weight or a maximum load. It is sectional drawing of the modification of the center pillar which concerns on embodiment of this invention. It is the schematic of the pillar model used for FEM analysis.

Explanation of symbols

1 Center pillar 4 Outer reinforcement (outer frame member)
5 Inner Reinforce (Inner skeleton member)
6 Reinforcing Reinforce (Reinforcing framework)
60c Projection 61a, 61b Central reinforcement wall (projection, sidewall)
62a, 62b End reinforcement wall

Claims (8)

An outer skeleton member, an inner skeleton member joined to the outer skeleton member at both ends in the vehicle front-rear direction, and an inner space formed between the outer skeleton member and the inner skeleton member. A vehicle center pillar structure comprising a reinforcing skeleton member disposed at least at a part on the upper end side in the direction,
The reinforcing skeleton member includes, in a longitudinal vertical cross section, a protruding portion formed to be bent toward the inner skeleton member at an intermediate portion in the vehicle longitudinal direction, and the outer side at both ends in the vehicle longitudinal direction. An end reinforcing wall portion extending toward the inner skeleton member along the skeleton member, and
The center pillar structure, wherein the reinforcing skeleton member is fixed to the outer skeleton member.   The projecting direction end portion of the projecting portion and the extending direction end portion of the end reinforcing wall portion are located on the outer side in the vehicle width direction than the coupling portion between the outer skeleton member and the inner skeleton member in the vehicle width direction. The center pillar structure according to claim 1, wherein the center pillar structure is formed as described above.   3. The reinforcing frame member according to claim 1, wherein the reinforcing skeleton member is formed so that a vertical cross-sectional shape in a longitudinal direction is symmetrical with respect to a center line passing through a center in a vehicle longitudinal direction. Center pillar structure.   The reinforcing skeleton member occupies a length occupied by the protruding portion, a length occupied by a portion positioned on one end side of the protruding portion, and a portion positioned on the other end side of the protruding portion in the vehicle longitudinal direction. 4. The center pillar structure according to claim 1, wherein the center pillar structure is formed such that the lengths are equal to each other. 5.   The reinforcing skeleton member is formed such that a protruding direction end portion of the protruding portion is positioned on an inner side in the vehicle width direction than a position of an extending direction end portion of the end reinforcing wall portion in the vehicle width direction. The center pillar structure according to claim 1, wherein the center pillar structure is a center pillar structure. The protrusion has a pair of side walls extending inward in the vehicle width direction,
6. A length in which the end reinforcing wall portion extends in a vehicle width direction is within a range of 0.7 to 0.9 times a length in which the pair of side walls extend. The center pillar structure according to at least one of the above.   7. The reinforcing skeleton member is fixed to the outer skeleton member in a state where only the end reinforcing wall portion is coupled to the outer skeleton member. The center pillar structure according to item 1. The protrusion has a pair of side walls extending inward in the vehicle width direction,
Based on the relationship obtained in advance by experiment or analysis of the length of the end reinforcing wall portion in the vehicle width direction, the length of the pair of side walls in the vehicle width direction, and the strength of the center pillar, a center pillar is desired. The reinforcing skeleton member is formed so as to have strength and to minimize the sum of the length of the end reinforcing wall portion and the length of the pair of side walls in the vehicle width direction. The center pillar structure according to 1.

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