JP3450708B2 - Car side frame reinforcement structure - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle side frame reinforcing structure in which a side frame of a vehicle body frame is reinforced by a reinforcing plate. 2. Description of the Related Art A conventional side frame reinforcing structure for an automobile is disclosed in Japanese Patent Application Laid-Open No. 8-2441. According to the above publication, a vehicle body frame is provided with sheet metal side frames constituting left and right side portions thereof, and each of these side frames constitutes a front portion thereof and is substantially horizontal in the front-rear direction. A front frame extending from the rear end of the front frame toward the rear lower side, and a rear frame extending substantially horizontally rearward from the rear end of the inclined frame; And at least a part of the front end of the inclined frame are overlapped with each other and joined by spot welding. In this case, the interior of the vehicle body above each of the inclined frame and the rear frame is a vehicle compartment. According to the above-mentioned side frame, the sub-frame for supporting the front wheels and the internal combustion engine for driving the vehicle is provided below the front frame by positioning the front frame higher. The sub-frame thus arranged is supported by the front frame. When the vehicle having the above structure travels forward, it collides with an object in front of the vehicle (hereinafter referred to as "front collision"), and a large impact force from the front end of the side frame toward the rear is generated. If given, since the side frame has a bent portion at the transition from the front frame to the inclined frame, the stress based on the impact force is concentrated on this bent portion, and the bent portion is There is a risk of being easily bent. As described above, if the bent portion is easily bent, the deformation of the vehicle compartment may be increased. In addition, as described above, when the bent portion is easily bent by the impact force, the overall amount of plastic deformation of the side frame is reduced, and energy is absorbed by the side frame based on the impact force. Therefore, the impact force may be transmitted to the rear side of the vehicle body without being sufficiently reduced. In the prior art, in addition to the above-described structure, a reinforcing plate for reinforcing a joint between the rear end of the front frame and the front end of the inclined frame is provided. A part of the reinforcing plate is joined to the front frame by spot welding, and the other part is overlapped with the both ends, that is, three sheets are overlapped and joined to each other by spot welding. The connection is reinforced. [0008] In the above-mentioned prior art, it is conceivable to increase the thickness of the reinforcing plate in order to reinforce the connecting portion so as to be stronger. In this case, the thickness of the three-layered portion becomes too thick, and it becomes difficult to perform spot welding of the three-layered portion with a normal welding gun for spot welding. Then, it is not easy to further improve the strength of the joint. Further, even if spot welding can be performed by increasing the thickness of the reinforcing plate as described above, there is a possibility that the strength of the three-layered portion becomes excessively large, and the portion adjacent to this portion is too large. Stress tends to concentrate on a part of the coupling part, and there is a possibility that the side frame may be bent at a part of the coupling part by an impact force at the time of collision. The present invention has been made in view of the above-mentioned circumstances, and the strength of the joint between the rear end of the front frame constituting the side frame and the front end of the inclined frame is made by a simple operation. In addition, at the time of "front collision" of the vehicle, stress concentration does not occur in a part of the joint portion to prevent bending of the side frame, thereby more effectively deforming the cabin. It is an object of the present invention to prevent the impact force transmitted to the rear side of the vehicle body including the vehicle compartment more effectively. In order to solve the above-mentioned problems, a vehicle side frame reinforcing structure according to the present invention has a body frame 3 provided with sheet metal side frames 13 constituting left and right side portions thereof. Each of these side frames 13 constitutes a front portion thereof, extends substantially horizontally in the front-rear direction, and has a substantially U- shaped cross section.
A front frame 20 that will be the shape, the inclined frame 2 extending towards the rear downward from the rear end of the front frame 20
Comprises a 1 and, at least a portion of the rear end of the front frame 20, and the mutually superimposed at least a portion of the front end of the tilt frame 21 is joined by spot welding S, and the front frame 20 Into the front
In a vehicle side frame reinforcing structure provided with a reinforcing plate 40 for reinforcing a joint portion 39 between a rear end of the frame 20 and a front end of the inclined frame 21, (1) forward of a front edge of the inclined frame 21 In the vicinity, the reinforcing plate 40 is joined to the front frame 20 by overlapping spot welding S, and in the front-rear direction,
Each part of the edge 21a at the front end of the inclined frame 21;
The two ends 21a, 40a of the reinforcing plate 40 are brought close to each other at the rear end 40a of the reinforcing plate 40 so that the two ends 21a, 40a face each other. In visual and / or planar view,
An imaginary line 44 along the longitudinal direction of the side frame 13
It is inclined with respect to. Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes an automobile, and an arrow Fr
Indicates the front of the vehicle body 2. The vehicle body 2 of the automobile 1 includes a vehicle body frame 3 made of sheet metal, and a vehicle body body 4 made of sheet metal which is positioned above the vehicle body frame 3 and supported by the vehicle body frame 3. Further, the body frame 3 includes a main frame 5 and
A sub-frame 6 positioned below the front of the main frame 5 and supported by the main frame 5; left and right front wheels 7 suspended by the sub-frame 6; The vehicle body 2 is supported on the running surface 9 by the left and right rear wheels suspended on the vehicle, and the subframe 6 supports an internal combustion engine for driving the vehicle. The main frame 5 of the vehicle body frame 3 extends in the front-rear direction across the vehicle body center 12 in the vehicle width direction of the vehicle body 2, and a pair of left and right side frames 13, 13 constituting left and right sides of the vehicle body frame 3. And these side frames 1
Side sills 1 which are located on the outer sides of the front and rear wheels 3 and 13 respectively and located between the front wheel 7 and the rear wheel in the front-rear direction
4 and these left and right side frames 1 extending in the vehicle width direction.
Together spot welded to the left and right side sills 14 and 14 and 3, 13 cross member is more bound to (× mark portion) 15,1
6, 17 and a cross member 18 protruding outward from a middle part of the side frame 13 in the front-rear direction.
The vehicle body 2 is substantially symmetric with respect to the vehicle body center 12. Each of the side frames 13 constitutes a front portion thereof and extends substantially horizontally in the front-rear direction.
From the rear end side of the front frame 20 toward the rear lower side.
And extending buildings tilt frame 21, and a rear frame 22 integrally extending substantially horizontally towards the rear end of the inclined frame 21 rearward. The inclined frame 21 is an intermediate frame that constitutes an intermediate part of the side frame 13 in the front-rear direction. The floor panel 26 constituting the lower part of the vehicle body 4 is connected to the rear frame 22 of the side frame 13.
And the upper surface of each of the cross members 16 and 17 are firmly connected to each other by spot welding S. The left and right side edges of the floor panel 26 are connected to the side sill 14. Further, a dash panel 27 is provided which constitutes a lower front part of the vehicle body 4 and extends from the front end side of the floor panel 26 toward the front upper side. The lower end of the dash panel 27 while being placed on the upper surface of the inclined frame 21 and the cross member 16 of each side frame 13, more binds to the spot welding thereto is placed above the cross member 18 Have been allowed. The interior of the vehicle body 4 is a vehicle room 28 above the floor panel 26 and above the dash panel 27. In addition, the respective portions of the floor panel 26 and the dash panel 27 in the vehicle body center 12 are bulged upward to form a tunnel portion 30. Each of the side frames 13 includes a side frame body 32 formed by press-molding a sheet metal material extending long in the front-rear direction. The side frame bodies 32 are slightly apart from each other when viewed in the cross section of each part in the longitudinal direction. A pair of facing plates 33, 33 facing each other;
A connecting plate 34 for integrally connecting one end edges thereof to each other as viewed in the cross section of each part in the longitudinal direction, and an outward flange integrally extending outward from the other end edge of each of the opposed plates 33. 35, and the cross section of each part in the longitudinal direction has a substantially U-shape that is lateral or upright. More specifically, the front frame 20 has a substantially U-shaped lateral frame whose side frame main body 32 opens toward the outside of the vehicle body 2, and the inclined frame 21 and the rear frame 22 The frame main body 32 has an upright, substantially U-shape. Each of the side frames 13 has a cross section in the longitudinal direction of the side frame main body 32.
Comprising a closed plate 36 is bordered spot soluble in these provided so as to straddle above both outward flanges 35 and 35, the closing plate 36 closes the opening of the side frame body 32. For this reason, each of the side frames 13 has a closed cross section at each of its longitudinal sections, and the internal space 37 inside thereof extends continuously along the longitudinal direction of the side frames 13. In the above case, the inclined frame 21
The closing plate 36 of the rear frame 22 is formed by a part of the floor panel 26. The closing plate 36 of the rear frame 22 is formed by a part of the floor panel 26. At least a part of the rear end of the front frame 20 and at least a part of the front end of the inclined frame 21 are overlapped so as to be surface-joined to each other. Have been. More specifically, as described above, the lower opposing plate 33 of the upper and lower opposing plates 33, 33 above the front frame 20 and the connecting plate 34 of the inclined frame 21 are mutually connected as described above. Have been combined. The coupling plate 34 of the front frame 20 and the opposing plate 33 on the vehicle body center 12 side of the opposing plates 33 of the inclined frame 21 are coupled to each other as described above. A reinforcing plate 40 is provided to reinforce the joint 39 between the rear end of the front frame 20 and the front end of the inclined frame 21. Near the front edge 21a of the front end of the inclined frame 21, the reinforcing plate 40 is fitted into the front frame 20 and overlapped by surface welding and joined by spot welding S. The reinforcing plate 40 is formed by press-molding a single sheet metal. The reinforcing plate 40 includes a pair of upper and lower opposing plates 41, 41 facing each other at a distance from each other, and the front frame 20 of the opposing plates 41, 41. And a connecting plate 42 for integrally connecting the edges on the side of the connecting plate 34 to each other. The cross section of each part of the reinforcing plate 40 in the longitudinal direction of the front frame 20 opens outward of the vehicle body 2. It is almost U-shaped. The opposing plates 33 of the front frame 20 and the opposing plates 41 of the reinforcing plate 40 are connected to each other as described above.
The zero coupling plate 34 and the coupling plate 42 of the reinforcing plate 40 are coupled to each other as described above. Edge 21 at the front end of the inclined frame 21
a and the respective portions of the edge 40a at the rear end of the reinforcing plate 40 are brought close to each other with a slight gap therebetween, and the both edges 21a and 40a are opposed to each other in abutting manner, And they are substantially parallel to each other as a whole. The side edges 21a and 40a are inclined by an acute angle with respect to an imaginary line 44 along the longitudinal direction of the side frame 13 in a side view and a plan view of the side frame 13. In other words, it is inclined by an acute angle with respect to another virtual line orthogonal to the virtual line 44. The inclination may be only one of the side view and the plan view. According to the above configuration, the reinforcing plate 40 is overlapped with the front frame 20 by spot welding S near the front end of the front end edge of the inclined frame 21, and the front end of the inclined frame 21 is The two ends 21a and 40a of the reinforcing plate 40 are opposed to each other by bringing the respective portions of the edge 21a of the portion closer to each other and the respective portions of the edge 40a of the rear end of the reinforcing plate 40. For this reason, since the reinforcing plate 40 is not overlapped on the double-layered portion of the rear end of the front frame 20 and the front end of the inclined frame 21, the reinforcing plate 40 is intended to reinforce the joint 39. Even if the reinforcing plate 40 is provided, it is possible to prevent the formation of a three-ply portion. Therefore, even if the thickness of the reinforcing plate 40 is increased, the front frame 20, the inclined frame 21, and the reinforcing plate 40 are mutually spot-welded using a normal spot welding welding gun. The work of S can be performed. That is, the strength of the connecting portion 39 can be further improved by a simple operation using a normal welding gun. When the strength of the connecting portion 39 is to be improved, as described above, since a three-ply portion does not occur, stress concentration occurs in a portion of the connecting portion 39 adjacent to this portion. That is avoided. Therefore, the impact force at the time of the “front collision” is applied to the side frame 13 around a part of the connecting portion 39.
Is prevented from bending. Therefore, as described above, the deformation of the passenger compartment 28 is effectively suppressed by the amount that the bending of the side frame 13 is prevented. In addition, since the bending is prevented as described above, the side frame 13 allows the front frame 20 to be plastically deformed as a whole in the longitudinal direction by the impact force. The energy based on the impact force is sufficiently absorbed, and the impact force transmitted to the rear side of the vehicle body 2 including the passenger compartment 28 is effectively reduced. The side edges 21a and 40a are inclined with respect to an imaginary line 44 along the longitudinal direction of the side frame 13 in a side view and a plan view of the side frame 13. Here, suppose that both ends 21a, 40a
Is perpendicular to the imaginary line 44, the section modulus in the longitudinal direction of the side frame 13 between the two end edges 21a and 40a is sharply reduced as compared with the portion adjacent thereto, so that stress concentration is caused in the portion. And tend to bend due to the impact force at the time of the “front collision”. Then, as described above, both end edges 21a,
The inclination of the side frame 40a prevents the sudden change in the section modulus of the side frame 13 in the longitudinal direction, thereby more reliably preventing the bending. Therefore, as described above, the deformation of the vehicle interior 28 is more reliably prevented, and the vehicle body 2 including the vehicle interior 28 is prevented from deforming.
The impact force that is to be transmitted to the rear side is more reliably reduced. Although the above description is based on the illustrated example, both ends 2
The inclination of the 1a and 40a with respect to the virtual line 44 may be only one of the side view and the plan view. According to the present invention, the vehicle body frame is provided with sheet metal side frames constituting left and right side portions thereof, and each of these side frames constitutes a front portion thereof and is substantially horizontal in the front-rear direction. a front frame section is Ru is substantially U-shaped extends, and a tilt frame extending toward the rear downward from the rear end of the front frame, and at least a portion of the rear end of the front frame At least a part of the front end of the inclined frame is overlapped with each other and joined by spot welding, and is fitted into the front frame and is inserted into the front frame.
In a vehicle side frame reinforcing structure provided with a reinforcing plate for reinforcing a joint between a rear end of a frame and a front end of an inclined frame, (1) near the front of the front edge of the inclined frame, The reinforcing plate is overlapped with the partial frame and joined by spot welding, and in the front-rear direction, each part of the edge of the front end of the inclined frame and each part of the edge of the rear end of the reinforcing plate are brought close to each other. These edges are opposed to each other. For this reason, since the reinforcing plate is not overlapped with the double-layered portion of the rear end of the front frame and the front end of the inclined frame, the reinforcing plate is provided to reinforce the joint. However, it is possible to prevent the occurrence of a three-ply portion. Therefore, even if the thickness of the reinforcing plate is increased,
By using a welding gun for ordinary spot welding, the front frame, the inclined frame, and the reinforcing plate can be spot-welded to each other. That is, the strength of the joint can be further improved by a simple operation using a normal welding gun. In order to improve the strength of the joint, since the three-ply portion does not occur as described above, stress concentration may occur in a part of the joint adjacent to this portion. Be avoided. Therefore, it is possible to prevent the side frame from being bent around a part of the connecting portion by the impact force at the time of “front collision”. Therefore, as described above, the deformation of the passenger compartment is effectively suppressed by the amount that the bending of the side frame is prevented. In addition, since the bending is prevented as described above, the side frames are plastically deformed as a whole by the impact force in the longitudinal direction of the front frame. The energy based on the force is sufficiently absorbed, and the impact force to be transmitted to the rear side of the vehicle body including the vehicle compartment is effectively reduced. (2) Both end edges are inclined with respect to an imaginary line along the longitudinal direction of the side frame in a side view and / or a plan view of the side frame. Here, assuming that the both ends are perpendicular to the imaginary line, the section modulus between the both ends in the longitudinal direction of the side frame is sharply reduced as compared with the portion adjacent thereto. Then, stress concentration occurs in the above-described portion, and the portion tends to be bent by the impact force at the time of the “front collision”. Therefore, as described above, both end edges are inclined, so that a sudden change in the section modulus in the longitudinal direction of the side frame is prevented, and the bending is more reliably prevented. You. Therefore, as described above, the deformation of the vehicle compartment is more reliably prevented, and the impact force transmitted to the rear side of the vehicle body including the vehicle compartment is more reliably reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a joint between a front frame and an inclined frame in a left side frame. FIG. 2 is a side view of a front portion of a vehicle body frame. FIG. 3 is a plan view of a front portion of a vehicle body frame. FIG. 4 is a partially enlarged view of FIG. 2; FIG. 5 is a partially enlarged view of FIG. 3; DESCRIPTION OF SYMBOLS 1 Automobile 2 Body 3 Body frame 12 Body center 13 Side frame 20 Front frame 21 Inclined frame 21a Edge 22 Rear frame 28 Chamber 39 Joint 40 Reinforcement plate 40a Edge 44 Virtual line S Spot welding

Claims (1)

(1) A vehicle body frame (3) includes sheet metal side frames (13) constituting left and right side portions thereof, and each of these side frames (13) is a front portion thereof. a front frame which substantially horizontally extending section in the longitudinal direction constitutes the Ru is substantially U-shape (20), inclined frame extending toward the rear downward from the rear end side of the front frame (20) (21 ) , At least a part of a rear end of the front frame (20) and at least a part of a front end of the inclined frame (21) are overlapped with each other and joined by spot welding (S) , and Is inserted into the front frame (20).
The rear end of the front frame (20) and the inclined frame (2)
A reinforcing plate (4 ) for reinforcing a joint (39) with the front end of ( 1).
0) in an automotive side frame reinforcement structure provided with, (1) at the front near the front edge of the inclined frame (21), spot welding superimposed on said front frame (20) above the reinforcing plate (40) ( S) , and the front edge (21 ) of the front end of the inclined frame (21) in the front-rear direction.
a) and the edge (4 ) of the rear end of the reinforcing plate (40).
These opposite edges is brought closer to each other and each part of 0a) (21
a, 40a) and are opposed to each other, (2) the end edges of the (21a, 40a) in a side view and / or plan view of the side frame (13), the virtual along the longitudinal direction of the side frames (13) Line (4
4) A side frame reinforcement structure for an automobile that is inclined with respect to the above.