JP3628821B2 - Hollow composite member - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hollow composite member that is formed by fitting a plurality of metal shaped members to each other, and is suitably used for, for example, a vehicle door beam.
[0002]
[Prior art]
Various shock-absorbing members that protect occupants from impact at the time of a collision are mounted on the vehicle as part of safety measures, but in recent years, as a shock-absorbing member for automobiles, for example, occupants are protected from the impact of a collision from the side. For this reason, a reinforcing lateral beam (door beam) has been mounted inside the door. The door beam is mainly intended to prevent obstacles from entering the door as much as possible. It is required to have high rigidity and high ability to absorb energy at the time of collision. Aluminum alloy hollow extrusions are used.
[0003]
For example, as shown in FIG. 7, such a hollow extruded shape member is cut into a member length, and then an iron bracket 5 is fixed to both ends of the extruded shape member 4, and a door is connected by a bolt 6 via the bracket 5. Attach to. Alternatively, as shown in FIG. 8, after cutting into member lengths (FIG. 8 (a)), both ends are cut obliquely (FIG. 8 (b)), and then a bolt hole is formed in one flange part, Attach to the door.
[0004]
However, when an aluminum extruded profile having a conventional hollow section having a closed cross section is applied as a door beam, there are generally the following problems.
(A) Since the closed cross-sectional shape has a large extrusion resistance, the extrusion speed is slow and the productivity is poor. Further, since the extrusion resistance is large, it is difficult to manufacture with a high-strength alloy such as 7075 (extra super duralumin), and the range of alloy selection is limited. This tendency is further strengthened as the cross-sectional shape becomes more complex.
(B) When heat treatment type aluminum alloy is used as the extruded material, quenching is required, but because of the closed cross-sectional shape, the cooling rate during quenching tends to be different, so the material strength depends on the part constituting the cross section. The variation comes out. If the variation in strength is large, the material properties will be different from the originally set characteristics, and naturally, a predetermined performance cannot be obtained, so that the yield is deteriorated. In particular, the tendency becomes stronger in the case where the thickness is reduced by using a high-strength material for weight reduction, the case where baking is performed by water cooling, or the case where the cross-sectional shape is more complicated.
[0005]
(C) When the door beam is mounted on the door using the bracket system as shown in FIG. 7, the number of parts increases and the processing of the bracket 5 is also required, which increases the manufacturing process, which is the total cost of the door beam. Push up. On the other hand, when the cutting method as shown in FIG. 7 is performed, an oblique cutting process is required, and the ground contact area with the door side is small as compared with the bracket method, and sufficient attachment strength may not be obtained.
[0006]
[Problems to be solved by the invention]
As described above, the problems of the conventional closed cross-section extruded shape have been described by taking the door beam as an example. However, these problems may occur when a closed cross-section extruded shape is manufactured and the extruded shape is used as a structural member. It is also a common problem when applied.
That is, the present invention has been made to solve the above-mentioned problems common to extruded profiles having a closed cross section applied to, for example, a door beam, and more specifically, an extruded profile having a closed cross sectional shape is manufactured. It is an object of the present invention to obtain a member having a closed cross section having no problems such as a decrease in extrusion speed, a limitation in material selection, and nonuniform cooling. Another object of the present invention is to obtain a member having a closed cross-sectional shape that can be used as a structural member with fewer steps for attachment to other members than before, and can secure sufficient attachment strength as required.
[0007]
[Means for Solving the Problems]
In the present invention, a plurality of metal profiles are fitted in the longitudinal direction at least at two places in the cross section, and a hollow closed cross section is configured along the longitudinal direction between the fitted metal profiles. The present invention relates to a hollow composite member. Here, the metal profile includes aluminum, aluminum alloy, and other metal extrusion profiles, as well as profiles manufactured by rolling or bending. The term “fitting” as used in the present invention means spring fitting or slide fitting described later.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
As long as a plurality of profiles constituting the hollow composite member have a closed hollow section along the longitudinal direction between the profiles when they are fitted, even a profile having a closed cross-section portion has an open cross-section. It can also be a profile (a profile that does not have a closed cross section). Each shape member has, for example, a plurality of ribs opposed to each other, and is fitted to each other at its tip portion, thereby forming a hollow closed cross section therebetween. These ribs are preferably parallel to the assumed load direction, and in the case of slide fitting, it is desirable that the ribs that fit each other in each section be provided on the same straight line as viewed in cross section (in cross section). If it is shifted to the left or right, a moment is applied and weak when a load is applied).
[0009]
FIG. 1 schematically shows a typical example of such a hollow composite member, and is composed of two metal extruded profiles (1) each having a groove-shaped open section made of a flange portion and a pair of ribs perpendicular to the flange portion. 2), (11, 12) are fitted along the longitudinal direction at the tip portions of the ribs on both sides of the concave portion with the concave portion side facing each other, and between the two profiles in the longitudinal direction A hollow closed cross section as shown in the figure is formed along.
[0010]
FIG. 1A shows an example in which both shape members 1 and 2 are spring-fitted. The spring fitting is made by elastically deforming the less rigid spring side. In the fitted state, the tip of the ribs of both shapes are engaged by elastic biasing force, and the longitudinal direction of the shape It doesn't move easily in the vertical direction.
FIG. 1B is an example in which the two shape members 11 and 12 are slidably fitted, and can be slid and fitted from the longitudinal direction of the shapes. The slide fitting is locked in the direction perpendicular to the longitudinal direction, and is stronger than the spring fitting, but it is not restrained in the longitudinal direction even after fitting. Some restraining means (for example, welding) is necessary in order to prevent slippage. In this example, the assumed load direction is the vertical direction in the figure, and the ribs 11a and 11b of both shape members are parallel to the load direction and in the same straight line when viewed in cross section.
[0011]
FIG. 2 is an example in which one of the metal extruded profiles 21 includes a hollow closed cross-section 21 a in part, and the concave shape of the groove-shaped open cross-section 21 b of the extruded profile 21 and the other extruded profile 22. The concave parts are facing each other, and the rib ends on both sides of the concave part are slidably fitted along the longitudinal direction of the profile. Between the two profiles, along the longitudinal direction, as shown in the figure A hollow closed section is formed.
[0012]
In the example of FIG. 1, the two extruded shapes constituting the hollow composite member are both groove-shaped open cross-sections, and when they are fitted, a hollow composite member with a closed cross-section that forms a pseudo-mouth shape is formed. The The shape of the open section is easy to extrude, and higher extrusion speeds are realized and there are fewer restrictions on material selection compared to the case of manufacturing such a hollow extruded section with a closed mouth shape as a single unit as before. Also, the uniformity of cooling is ensured.
In the example of FIG. 2, one of the two extruded profiles constituting the hollow composite member has a closed cross section, and the two are fitted to form a hollow composite member having two closed cross sections. Is done. In this case as well, extrusion is easier than in the case where a hollow extruded shape having two closed cross sections is manufactured as a single piece as usual.
[0013]
In the hollow composite member according to the present invention, a resin can be provided on the inner side of the hollow closed cross section formed along the longitudinal direction between the fitted metal profiles, if necessary. For example, resin is affixed to the concave portion (see FIG. 1 or FIG. 2 for the concave portion) of one or both of the shapes before fitting, and both shapes are fitted as they are. With a conventional hollow extruded shape, it is difficult to attach a resin to the inside of a narrow hollow portion, but it can be easily achieved with the hollow composite member according to the present invention. If a reinforcing resin such as FRP is affixed as the resin, it is possible to reduce the weight by reducing the thickness of the parting material, and in addition, a resin according to the purpose such as vibration control, heat insulation, and soundproofing can be appropriately affixed.
[0014]
In the hollow composite member according to the present invention, if any one of the plurality of metal profiles is longer than the other metal profiles, this elongated portion can be used as an attachment portion for the other members. In particular, in the case of a profile with an open section, if one or both of the elongated sections of the elongated profile are spread out, a flat and wide joint area can be secured, the mounting strength can be improved, and in particular, the slide fit In the case of the joint, the expanded portion prevents the other shape members from sliding in the longitudinal direction, and fixing means such as welding becomes unnecessary.
[0015]
FIG. 3 is an example in which the hollow composite member according to the present invention is applied to a door beam and the long portions on both sides are pushed and spread. This door beam is composed of two extruded aluminum members 31 and 32 having essentially the same cross-sectional shape as described with reference to FIG. 1B, and one of the members 32 is longer than the other member 31, A portion (long portion) extending longer than the other shape member 31 of the shape member 32 is pushed and spread on both sides, and is flattened at both ends. FIG. 4 shows the door beam attached to the door frame. The door beam of the present invention can also be used as a truck door beam that needs to have collision resistance from the front.
[0016]
In this way, a wide weld joint area can be secured in the case of welding by expanding the long part, and when joining with bolts and rivets, the number of bolts and rivets is increased, and the distance between the bolt holes is increased. Thus, stress concentration around the bolt hole can be reduced. At the same time, the longitudinal portion of the other shape member 31 is prevented from sliding in the longitudinal direction by the elongated long portion, and the two shape members 31 and 32 are fixed to each other.
[0017]
Japanese Patent Application Laid-Open No. 5-270263 discloses that a short reinforcing material having an inward recess is fitted to the outer periphery of a long beam body having an outward protrusion to form a door beam. . However, the invention of this publication does not include the technical idea of obtaining a hollow closed cross-section door beam by fitting two open cross-section profiles. Therefore, the invention of this publication does not solve the problems of the prior art related to the extruded profile. In the invention of this publication, since the outer surface of the long shape material and the inner surface of the short shape material are almost fit together, a large weight increase is required to increase the section modulus and improve the resistance to bending load. However, the present invention can increase the section modulus much more efficiently. Furthermore, in the door beam of the above publication, the long shape has a closed cross section, and it is impossible to push the long portion and use it as an attachment portion.
[0018]
Further, in the example of FIG. 3, the lower corner portion of the long shape member 32 is a corner portion. However, in the example shown in FIG. By attaching an appropriate R (roundness), the formability when the long portion is expanded and formed flat can be improved, and an attachment portion with good flatness can be obtained.
[0019]
In the description so far, the plurality of profiles constituting the hollow composite member according to the present invention are each composed of one profile (that is, each of the plurality of profiles, for example, the profile 31 and the profile). 32 are each one shape), but can be configured by combining a plurality of shapes having arbitrary cross-sectional shapes (however, the fitting portions have the same shape) as necessary. . In other words, a plurality of shapes sharing the fitting portion are fitted to one shape constituting the hollow composite member.
[0020]
Thereby, some additional function can be provided.
For example, FIG. 6 shows an example of a door beam similar to FIG. 3, but the long side member 42 is made of a single member having the same shape as the shape member 32 of FIG. It consists of two shape members 41a, 41b, 41a (41a is the same cross-sectional shape as the shape member 31 of FIG. 3), and all are slidably fitted to the shape member 42 on the long side. Since the short side shape member 41b is fixed by the long portion where the short side shape members 41a on both sides are spread out by the shape member 42, welding or the like for fixing is unnecessary. The plate portion extended to the left and right of the shape member 41b can be used as a bracket for attaching components in the door such as a wire harness, a window regulator, and an auto-lock device. Of course, the shape of the shape members 41a and 41b can be arbitrarily changed according to the vehicle type, door thickness, purpose, and the like.
[0021]
In the hollow composite member according to the present invention, the material of any one of the plurality of metal profiles can be freely made different from the material of the other profiles. For example, a combination of aluminum alloys of different materials may be used, or a combination of an aluminum alloy and another metal may be used. It goes without saying that this material includes various properties that can be changed depending on the tempering and components in addition to the Young's modulus and the material structure. By doing so, it is possible to obtain a hollow composite member (having a pseudo-cladding meaning) having different characteristics.
As a modification thereof, when a plurality of shapes sharing the fitting portion are fitted to one shape constituting the hollow composite member (see paragraph 0019), the materials of the plurality of shapes are changed. The application method of making it mutually different is also considered.
[0022]
As an example of changing the shape material, for example, when a hollow composite member having a cross-sectional shape shown in FIG. 1 (b) is applied to a beam member as a building structure material, both ends of the beam member are supported from the top in the center. If a bending load is applied, using a high-strength material on the upper side where the compressive force is applied (inside the bend) and a high ductility material on the lower side where the tensile force is applied (outside the bend), Cracking can be delayed, and as a result, the amount of energy absorption required as a safety member can be earned.
[0023]
In addition, as another example, a shape with excellent weldability and a shape with excellent corrosion resistance are combined, and the shape with excellent weldability is fixed to other members by welding to the inside, resulting in excellent corrosion resistance. It is also conceivable to direct the profile to the outside exposed to the external environment.
Furthermore, even if the same aluminum alloy is used, for example, it is possible to control the neutral axis of the cross section from the material surface by combining shapes made of materials having different Young's moduli. If it is biased closer to the tension side than the center, when bending with the same curvature is applied, the stress and strain on the tension side can be reduced and cracking can be suppressed compared to when the neutral axis is in the center of the cross section. it can.
[0024]
The hollow composite member according to the present invention can be used for various applications as a bending member in the same manner as an ordinary extruded profile. In this case, it is desirable that the fitting portion is on the neutral axis of bending. This is because, on the neutral axis of bending, the stress and strain of compression and tension are theoretically zero, and no significant load is applied to the fitting portion, and the fitting portion is difficult to come off.
In addition, if a high-strength material is used on the inner side of a bend where compressive force is applied and a high-ductility material is used on the outer side of a bend where tensile force is applied, cracking on the outer side when subjected to bending can be delayed, resulting in bending workability. Is improved and can be bent with a smaller R.
[0025]
【The invention's effect】
As described above, the hollow composite member according to the present invention solves problems such as a decrease in extrusion speed, a limitation in material selection, and uneven cooling, which are problems when manufacturing an extruded shape having a closed cross-sectional shape. Is done. In addition, when using this as a structural member, for example, if one of the shape members is long, this can be used as an attachment portion to other members, and in particular, the long portion of a long shape member with an open cross section If this is expanded and used as an attachment portion, sufficient attachment strength can be secured.
Furthermore, the hollow composite member according to the present invention can be easily provided with resin on the inside of the hollow closed cross section, and the pseudo clad material having different characteristics by changing the material of a plurality of shapes to be fitted. It can be.
[Brief description of the drawings]
FIG. 1 is a schematic view of a cross section of a hollow composite member according to the present invention, showing a spring fit (a) and a slide fit (b), respectively.
FIG. 2 is a schematic view of a cross section of a hollow composite member according to the present invention.
FIG. 3 is an example in which the present invention is applied to a door beam of a vehicle.
FIG. 4 is a diagram showing the state of attachment.
FIG. 5 is a view showing another example of a door beam according to the present invention.
FIG. 6 is a view showing another example of a door beam according to the present invention.
FIG. 7 is a diagram illustrating a conventional door beam mounting process.
FIG. 8 is also a diagram for explaining a conventional door beam mounting process.
[Explanation of symbols]
1, 2, 11, 12, 22 Extruded profiles 11a, 11b with open cross section Ribs 21 of extruded profiles 21a Extruded profiles 21a with closed cross sections Hollow closed cross sections 22b Groove-shaped open cross sections 31, 41a, 41b Door beams Extruded sections 32, 42 on the short side of the door Extruded sections on the long side of the door beam

Claims (8)

A long metal shape is fitted to one long metal shape along the longitudinal direction in at least two places in the cross section, and in the longitudinal direction between the fitted metal shapes. A hollow closed cross section is formed along the length, and the long metal profile is an open profile, and only one or both of the long sections of the profile are expanded to form a mounting portion with another member. A hollow composite member characterized by that. A plurality of short metal profiles are fitted to the long metal profile along the longitudinal direction, and the long metal profile is longer than the total length of the short metal profiles. The hollow composite member according to claim 1, wherein The long metal profile and the short metal profile have a plurality of ribs facing each other, and are fitted to each other at the end portions of the ribs. Hollow composite member. The hollow composite member according to any one of claims 1 to 3, wherein a material of at least one of the plurality of metal profiles is different from a material of the other metal profiles. . The hollow composite member according to claim 1 , wherein a resin is provided inside the hollow closed cross section. The hollow composite member according to claim 1 , wherein the hollow composite member is a structural member for a vehicle. The hollow composite member according to claim 6 , wherein the hollow composite member is a door beam. The hollow composite member according to claim 1 , wherein the hollow composite member is a bending member.

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