JP5112886B2 - Body frame member - Google Patents

Description

  The present invention relates to a vehicle body frame member having a closed cross-section member.

In a vehicle body of a general passenger car or the like, a monocoque structure in which panel parts and frame parts are joined together by welding or the like is often used to reduce the weight and increase the rigidity. Among such frame members of a vehicle body, those having a tubular closed cross-section member extending with a relatively complicated shape may require improvement in component accuracy and ensuring rigidity (for example, Patent Documents). 1).
JP 2002-166848 A

The closed cross-section member as described above is an existing hydroform molding (a metal tube set in a mold is filled with a liquid, and the liquid is pressurized to bulge the metal pipe to follow the internal shape of the mold. It is desirable to manufacture by the method of shape).
On the other hand, in the closed cross-section member, when the closed cross-section is crushed when a heavy load such as an impact load is applied, the load cannot be stably received. It is desirable to add a reinforcing member such as a bracing member (diagonal member) in the cross section.
However, a closed cross-section member manufactured by hydroforming, in particular, has a completely closed cross-section because it is filled with hydraulic pressure, and its cross-sectional shape changes depending on the position in the longitudinal direction and is appropriately bent and crushed. Therefore, there is a problem that it is difficult to add a reinforcing member in the cross section. Further, it is conceivable to add a reinforcing member so as to cover the outer periphery of the cross-section of the closed cross-section member, but in this case, there is a problem that the body frame member is likely to be increased in size and greatly increased in weight.
Accordingly, the present invention provides a vehicle body frame member having a closed cross-section member manufactured by hydroform molding or the like, which suppresses an increase in size and weight and uses a method for mass production and reinforces the cross-section of the closed cross-section member. The purpose is to add a member.

As a means for solving the above problems, the invention described in claim 1 is a vehicle body frame member (for example, the upper frame 3 of the embodiment) having a closed cross-section member (for example, the frame main body 3a of the embodiment). An upper frame of a front bulkhead, which is a vehicle body frame member formed by subjecting a round steel pipe to hydroform molding and having the above-mentioned closed cross-sectional member having a different cross-sectional shape depending on the position in the longitudinal direction thereof, and an upper side portion extending to the left and right (For example, the upper side portion 5 of the embodiment) and left and right oblique side portions (for example, the left and right oblique side portions 6 of the embodiment) that are curved and extend from both sides of the upper side portion toward the oblique rear side. The rear end portion is coupled to the front end portion of the wheel house upper member (for example, the wheel house upper member 12 of the embodiment), and at least the left and right sides of the upper side portion. The cross-sectional shape of the part located on the side connects the front wall part and the rear wall part orthogonal to the front-rear direction (for example, the front wall part 21 and the rear wall part 22 in the embodiment) and the front wall part and the rear wall part. A vertically long rectangular shape having an upper wall portion and a lower wall portion (for example, the upper wall portion 23 and the lower wall portion 24 in the embodiment), and a rod-shaped member (from the front wall portion to the rear wall portion) For example, 25, 125, 225) of the embodiment is inserted, both ends of the rod-shaped member are connected to both the front wall portion and the rear wall portion , and at least the front end of the rod-shaped member is connected to the rod-shaped member. A nut hole (for example, the nut hole 28 in the embodiment) is formed along the axial direction.
According to a second aspect of the present invention, insertion holes (for example, the front insertion hole 31 and the rear insertion hole 32 in the embodiment) through which the rod-shaped member is inserted are formed in the front wall portion and the rear wall portion, respectively, and the rod-shaped member Is inserted through the insertion hole, and the front and rear end portions thereof protrude from the front wall portion and the rear wall portion, respectively, and are welded to the front wall portion and the rear wall portion outside the front wall portion and the rear wall portion. It is characterized by being.
According to a third aspect of the present invention, a flange portion (for example, the flange portion 27 of the embodiment) is formed at the front end or the rear end of the rod-shaped member, and the rod-shaped member is connected to the front wall portion or the rear portion. It is inserted into the insertion hole in contact with the wall portion, and the entire circumference of the flange portion is welded to the front wall portion or the rear wall portion.
The invention described in claim 4 is characterized in that the front wall portion and the rear wall portion are inclined forward and downward.

  According to the present invention, an arbitrary hole in the closed cross-section member can be obtained by simply drilling a pair of wall portions forming a closed cross-section in the closed cross-section member, and inserting and fixing a rod-like member to the closed cross-section member. A bar-shaped member as a diagonal-shaped reinforcing member can be added in the cross section of the portion. In other words, compared to the case where a reinforcing member that covers the outer periphery of the cross-section of the closed cross-section member is added, the increase in size and weight is suppressed, and for mass production such as drilling in the closed cross-section member, insertion of a rod-shaped member, and fixation After using the method, a diagonal reinforcing member can be added in the cross section of the closed cross-section member manufactured by hydroforming or the like.

  Hereinafter, an example in which the present invention is applied to an upper frame of a front bulkhead of a vehicle body of a passenger car will be described with reference to the drawings. Note that the directions such as front, rear, left and right in the following description are the same as those in the vehicle unless otherwise specified. In the figure, the arrow FR indicates the front of the vehicle, the arrow LH indicates the left side of the vehicle, and the arrow UP indicates the upper side of the vehicle.

  FIG. 1 shows a front portion of a vehicle body 1 having a monocoque structure in which panel parts and frame parts in a general passenger car are integrally joined by welding or the like. A frame-shaped front bulkhead 2 that supports and protects a radiator (not shown) is provided at the front of the vehicle body 1. The front bulkhead 2 is mainly composed of an upper frame 3 constituting the upper part and a lower frame 4 constituting the lower part.

  The upper frame 3 includes an upper side portion 5 extending in the left-right direction and left and right oblique side portions 6 extending curvedly from both sides of the upper side portion 5 toward the diagonally rearward outer side. On the other hand, the lower frame 4 includes a lower side portion 7 extending left and right, and left and right side portions 8 extending curvedly upward from both sides of the lower side portion 7.

  Upper ends of the left and right side portions 8 of the lower frame 4 are joined to the lower surfaces of both sides of the upper side portion 5 of the upper frame 3. The rear end portion of the left and right oblique sides 6 of the upper frame 3 is joined to the front end portion of the wheel house upper member 12 extending forward and backward at the rear thereof. To the rear surface of the left and right side portions 8 of the lower frame 4, the front end portion of the front side frame 13 extending in the front-rear direction at the rear thereof is joined. In the figure, reference numeral 14 denotes a damper housing, and reference numeral 16 denotes a dash upper panel.

  Here, the upper frame 3 mainly includes a tubular frame body 3 a having a hollow cross-sectional shape (closed cross-sectional structure) and extending along the upper side portion 5 and the left and right oblique side portions 6. The frame body 3a is formed, for example, by hydroforming or the like on a round steel pipe, and has a different cross-sectional shape depending on its longitudinal position.

Referring also to FIG. 2, the cross-sectional shape of at least the left and right sides of the upper side portion 5 of the frame body 3 a is, for example, the front and rear wall portions 21 and 22 orthogonal to the front-rear direction and the top and bottom inclined slightly downward. It has a slightly vertically long rectangular shape having wall portions 23 and 24.
Here, the left and right sides of the upper side portion 5 of the frame body 3a are also portions where the load is likely to concentrate when a load is applied from the front of the vehicle, for example.
Therefore, for example, a steel rod-like member 25 extending in the front-rear direction is inserted and fixed on the left and right sides of the upper side portion 5 of the frame body 3a so as to penetrate the closed cross section across the front-rear wall portions 21 and 22. .

  The rod-shaped member 25 includes a columnar shaft portion 26 that is a main body portion thereof, and a disk-shaped flange portion 27 formed on one end side (front end side in the drawing) of the shaft portion 26. A nut hole 28 is bored along the longitudinal direction of at least the front shaft center of the shaft portion 26. The nut hole 28 opens to an end surface (front end surface) on the flange portion 27 side of the shaft portion 26, and a support stay 29 that supports, for example, a strut tower bar or a horn is fixed to the nut hole 28 with a bolt B. . That is, the rod-shaped member 25 functions as a collar nut having a predetermined axial length. The nut hole 28 may penetrate the shaft portion 26. In other words, the rod-shaped member 25 may be a hollow (pipe-shaped) member. Further, a plurality of rod-like members 25 are provided on each of the left and right sides of the frame main body 3a (two in the figure), but the number and arrangement thereof can be appropriately changed.

  Front and rear insertion holes 31 and 32 through which the shaft portion 26 of the rod-shaped member 25 can be inserted are formed in the front and rear wall portions 21 and 22 of the frame main body 3a, respectively. The rod-like member 25 is inserted into the cross section of the frame main body 3a through the front insertion hole 31 from the end portion (rear end portion 34) opposite to the flange portion 27, and the rear end portion 34 is inserted into the rear insertion hole. A predetermined amount (for example, approximately the same as the thickness of the flange portion 27) is projected from 32 to the outside of the cross section of the frame body 3a.

  At this time, the surface of the flange portion 27 on the shaft portion 26 side contacts the front surface of the front wall portion 21 (the outer surface of the frame body 3a), and in this state, the outer periphery of the flange portion 27 (also the front end portion 33 of the rod-like member 25). Is welded to the front wall portion 21 of the frame body 3a over the entire circumference, for example, by arc welding, and the outer periphery of the rear end portion 34 of the shaft portion 26 is also welded to the entire circumference of the rear wall portion 22 of the frame body 3a by arc welding. By being welded across, the front and rear end portions 33 and 34 of the rod-shaped member 25 are respectively coupled to the front and rear wall portions 21 and 22 of the frame main body 3a, and the rod-shaped member 25 and the frame main body 3a are integrated.

  Thereby, the rod-shaped member 25 functions as a diagonal-shaped reinforcing member added in a cross section at a predetermined position of the frame main body 3a, and the closed cross section of the frame main body 3a is crushed even when a heavy load such as an impact load is applied. This makes it possible for the frame body 3a to stably receive the load, and to transmit the load to the wheel house upper member 12 and the front side frame 13. In particular, since the flange portion 27 of the rod-shaped member 25 is in a relatively large area and contacts the front wall portion 21 of the frame body 3a, deformation of the front wall portion 21 around the front insertion hole 31 is effectively suppressed, and the crushing is suppressed. Effectively suppress. Further, since the rod-shaped member 25 also serves as a fixing part for other parts, it is possible to rationalize the design such as the reduction in the number of parts.

Next, a method for manufacturing the upper frame 3 will be described with reference to FIG.
First, for example, a straight round steel pipe P as a material of the frame body 3a is prepared, and the steel pipe P is bent using a pipe bender machine or the like to form a schematic shape of the frame body 3a (FIG. 3 ( a)).
Next, a pre-crash process using a press or the like (closed so as to enter a later hydroforming mold) is applied to a predetermined part (the part corresponding to the upper side 5 in the figure) of the steel pipe P after the bending process. A process of crushing the cross section by a predetermined amount) is performed (see FIG. 3B).

Next, the pre-crushed steel pipe P is set in a hydroforming mold, and the mold is closed while applying a low hydraulic pressure to the steel pipe P, whereby a predetermined portion of the steel pipe P is crushed or bent by a predetermined amount. A hydrobending process is performed (see FIG. 3C).
After the mold is closed, a high fluid pressure is applied to the steel pipe P to perform hydroforming, thereby forming a frame body 3a having a desired three-dimensional shape (see FIG. 3D).

The frame body 3a after the formation is subjected to drilling processing including the formation of the front and rear insertion holes 31, 32, and then the rod-like member 25 is inserted and fixed to the frame body 3a as described above. The upper frame 3 is configured by adding a rod-shaped member 25 as a diagonal-shaped reinforcing member in a cross section of a predetermined portion of the frame body 3a (see FIG. 3E).
The hydroform molding described above is an existing shape in which a steel pipe P set in a mold is filled with a liquid, and the liquid is pressurized to bulge the steel pipe P to follow the internal shape of the mold. It is a construction method.

  As described above, the vehicle body frame member (upper frame 3) in the above-described embodiment mainly includes the frame main body 3a which is a closed cross-section member manufactured by hydroforming, and the frame main body 3a is closed to the frame main body 3a. The rod-shaped member 25 is inserted so as to reach from the wall portion on one side (front wall portion 21) forming the cross section to the wall portion on the other side (rear wall portion 22), and the front and rear end portions 33, 34 of the rod-shaped member 25 are inserted. And the front and rear wall portions 21 and 22 of the frame main body 3a.

  According to this configuration, the frame main body can be obtained by simply perforating the pair of walls 21 and 22 forming the closed cross section of the frame main body 3a, and inserting and fixing the rod-like member 25 to the frame main body 3a. The rod-shaped member 25 as a diagonal-shaped reinforcing member can be added in the cross section of the arbitrary places in 3a. That is, compared with the case where a reinforcing member that covers the outer periphery of the cross section of the frame main body 3a is added, an increase in size and weight is suppressed, and for mass production such as drilling in the frame main body 3a, insertion of the rod-like member 25, and fixing. After using this method, a diagonal reinforcing member can be added in the cross section of the frame body 3a manufactured by hydroforming.

  In addition, this invention is not restricted to the said Example, For example, as shown to Fig.4 (a), it replaces with the said rod-shaped member 25, and has the flange part 27 in the rear-end side instead of the front-end side of the axial part 26. It is good also as a structure using the rod-shaped member 125. FIG. The rod-like member 125 has its shaft portion 26 inserted from the front end portion 33 into the cross section of the frame main body 3 a through the rear insertion hole 32, and the front end portion 33 replaces the front insertion hole 31 in the front wall portion 21. 'Contact the surrounding rear surface (the inner surface of the frame body 3a). The front bolt hole 31 ′ is coaxial with the front insertion hole 31 and has a slightly smaller diameter.

At this time, the shaft portion 26 side surface of the flange portion 27 abuts on the rear surface of the rear wall portion 22 (the outer surface of the frame body 3a), and in this state, the flange portion 27 (also the rear end portion 34 of the rod-shaped member 125). The outer periphery is welded to the rear wall portion 22 of the frame main body 3a over the entire circumference by, for example, arc welding, and the front end portion 33 of the shaft portion 26 is fixed to the front wall portion 21 by tightening the bolt B. The front and rear end portions 33 and 34 of the rod-shaped member 125 are coupled to the front and rear wall portions 21 and 22 of the frame body 3a, respectively, so that the rod-shaped member 125 and the frame body 3a are integrated.
In the drawing, the front end portion 33 of the rod-shaped member 125 is not welded to the front wall portion 21 of the frame main body 3a, but the front end portion 33 may be welded to the front wall portion 21. At this time, the front end portion 33 of the rod-shaped member 125 may be protruded from the front wall portion 21.

Further, as shown in FIG. 3B, instead of the rod-like member 25, a rod-like member 225 including a simple columnar shaft portion 26 that does not have the flange portion 27 and the nut hole 28 may be used. The rod-shaped member 225 penetrates the closed cross section of the frame body 3a across the front and rear wall portions 21 and 22, and projects the front and rear end portions 33 and 34 from the front and rear wall portions 21 and 22 by a predetermined amount. The outer circumferences of the end portions 33 and 34 are welded to the front and rear wall portions 21 and 22 of the frame main body 3a over the entire circumference, for example, by arc welding, so that the front and rear end portions 33 and 34 of the rod-like member 225 are front and rear of the frame main body 3a. The rod-like member 225 and the frame body 3a are integrated by being coupled to the wall portions 21 and 22, respectively.
Note that at least one of the front and rear end portions 33 and 34 of the rod-like member 225 may be fixed to the frame main body 3a by the bolt B as described above. At this time, it does not matter whether other parts are fastened together (the same applies to the case of FIGS. 2 and 3A).

Further, for example, a bar-like member may be provided so as to extend over the upper and lower wall portions 23 and 24 of the frame body 3a. Further, the cross-sectional shape of the frame main body 3a (closed cross-section member) is not limited to a rectangular shape. Therefore, the frame main body 3a (closed cross-section member) reaches from the one side wall portion constituting the closed cross-section of the closed cross-section member to the other side wall portion substantially opposed thereto. As long as the rod-shaped member is provided as described above, it is sufficient.
Moreover, the closed cross-section member is not only manufactured by hydroform molding, but also manufactured by roll foam molding, manufactured by simple processing of a pipe, or manufactured by appropriately combining a plurality of members. There may be. The material of the closed cross-section member is not limited to a round steel pipe, but may be a metal pipe (including an aluminum pipe or a stainless steel pipe) having a cross-sectional shape such as a square. Similarly, the rod-shaped member may be made of various metals other than steel, or resin.
The configuration in the above embodiment is an example of the present invention, and is not limited to the application of the front bulkhead to the upper frame, and vehicles other than passenger cars (buses, trucks, motorcycles and tricycles, motorbikes, bicycles, four Needless to say, various modifications can be made without departing from the scope of the invention.

It is a perspective view of the vehicle body front part in the Example of this invention. It is AA sectional drawing of FIG. It is explanatory drawing which shows the manufacturing process of the upper frame of the front bulkhead of the said vehicle body in order of (a)-(e). (A), (b) is sectional drawing equivalent to FIG. 2 which shows the modification of the said Example.

Explanation of symbols

1 Car body 2 Front bulkhead 3 Upper frame (car body frame member)
3a Frame body (closed section member)
21 Front wall (wall)
22 Rear wall (wall)
25, 125, 225 Bar-shaped member 33 Front end (end)
34 Rear end (end)

Claims (4)

In a vehicle body frame member having a closed cross-section member,
The vehicle body frame member is an upper frame of a front bulkhead, and is a vehicle body frame member formed by subjecting a round steel pipe to hydroform molding and having the closed cross-section member having a different cross-sectional shape depending on its longitudinal position. The left and right oblique sides extending from the opposite sides of the upper side to bend obliquely outward, and the rear end of the left and right oblique sides is located at the front end of the wheel house upper member. Combined,
At least the cross-sectional shapes of the portions located on the left and right sides of the upper side part are a front wall part and a rear wall part orthogonal to the front-rear direction, and an upper wall part and a lower wall part that connect these front wall part and rear wall part, A vertically long rectangular shape having
Inserting a rod-like member so as to reach the rear wall portion from the front wall portion, and connecting both end portions of the rod-like member to both the front wall portion and the rear wall portion ;
A vehicle body frame member , wherein a nut hole is formed at least at a front end of the rod-shaped member along an axial direction of the rod-shaped member.   The front wall portion and the rear wall portion are each formed with an insertion hole through which the rod-shaped member is inserted, and the rod-shaped member is inserted into the insertion hole, and the front and rear end portions thereof are respectively the front wall portion and the rear wall portion. The vehicle body frame member according to claim 1, wherein the vehicle body frame member is protruded from the front wall portion and welded to the front wall portion and the rear wall portion outside the front wall portion and the rear wall portion.   A flange portion is formed at the front end or the rear end of the rod-shaped member, and the rod-shaped member is inserted into the insertion hole with the flange portion abutting against the front wall portion or the rear wall portion, The vehicle body frame member according to claim 2, wherein the entire periphery is welded to the front wall portion or the rear wall portion. The front wall and the rear wall portion, a body frame member according to any one of claims 1 to 3, wherein the inclined forwardly downward.

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