A BEAM CONNECTION

Abstract: Beam knot forming part of a vehicle body structure and being constructed of three beam elements (1, 2, 3) which each discloses two side walls (4-9) which extend with relative intervals and a transverse wall (10-12) which connects said side walls. The beam elements are rigidly connected with each other in the beam knot and protrude from this in respective directions. One of the beam elements (1) discloses a recess (13) in one side wall (6) thereof, another beam element (2) inserts transversely through the recess with a section and is connected with the opposite side wall (7). A third beam element is partly situated in the first beam element and is with its side walls (8, 9) connected with the side walls (4, 5) of the second beam element.

Description: A BEAM CONNECTION. TECHNICAL FIELD: The present invention relates to a beam knot forming part of a vehicle body structure and comprising at least three beam elements, which each discloses two side walls which extend with relative intervals and at least one transverse wall which connects said side walls and which beam elements are rigidly connected with each other in the beam knot and protrude from this in respective directions. BACKGROUND OF THE INVENTION: Previously, beam knots in vehicle body structures, generally comprising three beam elements which are connected with each other, have been constructed in such manner that two of the beam elements have been connected with their ends to a longitudinal beam element. Generally, a floor panel is included which covers two of the beam elements and supports the third beam element. In this regard, the connection only takes place between two of the beam elements and, furthermore, in one single plane for each connection. Considering the increasingly extensive demands that for security reasons and other motives are called for structural strength in vehicle body structures, the known solution discloses an unsatisfying strength on account of a limited rigidity and capacity for load transmission between the beam elements. SUMMARY OF THE INVENTION: The object of the present invention is to provide a beam knot which satisfies extensive demands for structural strength, have a long service life and allows utilization of efficient assembly methods. Said object is achieved by means of a beam knot according to the present invention, which is characterized in that a first beam element of said beam elements discloses a recess in one side wall thereof, which recess is limited by two side edges, that a second beam element of said beam elements inserts transversely through said recess with a section and is connected with the opposite side wall of the first beam element and discloses a width between its side walls which corresponds to the width of the recess between its side edges, and that a third beam element of said beam elements is partly situated in the first beam element and with its side walls is connected with at least the side walls of the second beam element and connects to the opposite side wall of the first beam element. By means of the beam knot according to the invention, at least three beam elements are connected directly with each other along more than one connecting plane for each beam element, which provides a high degree of rigidity and a satisfying load transmission between the beam elements, and also a long service life. BRIEF DESCRIPTION OF THE DRAWINGS: The invention will be further described in the following with reference to the preferred embodiments and to the appended drawings, in which Fig. 1 is an exploded view which shows a schematic example of the elements forming part of the beam knot, and Fig. 2 is a perspective view which shows a practical embodiment of the beam knot according to the invention in assembled state. PREFERRED EMBODIMENT: In a preferred embodiment, the beam knot according to the invention forms part of a vehicle body structure for motor vehicles, for example a vehicle body structure where the floor structure is connected with the side structures of the vehicle, which comprise standing or vertical beam elements in front of, between or behind the vehicle's doors. As is best apparent from Fig. 1, the beam knot in the schematically shown example is intended for assembly of three beam elements, more precisely a first beam element, henceforth called the longitudinal beam 1, a second beam element, henceforth called the cross beam 2, and a third beam element, henceforth called the beam foot 3. In the shown example, the longitudinal beam is intended to extend in the longitudinal direction of the vehicle body structure, whereas the cross beam is intended to extend in the latitudinal direction of the structure and the beam foot in the vertical as well as the latitudinal direction. However, according to which structure has been selected, the beam knot can be turned in any optional direction so that each beam can have a completely different direction. All of the beams 1, 2, 3 are of the channel beam type, i.e. they have essentially a U-profile form, which is a fundamental condition for at least two of the beams at least in those sections which are intended to be connected with each other in the assembled beam knot. Thus, each beam discloses two side walls 4-9 which in each beam travel two and two in parallel planes with a selected relative distance. The side beams in each beam 1, 2, 3 are held together by means of a transverse wall 10, 11, 12 which extends transversely to, i.e. essentially at right angles to, the side walls. In the two horizontal beams 1, 2, the transverse wall 10, 11 forms a base portion, i.e. so that the profile form is a U turned the right way round, whereas the third beam 3 has a reversed profile form, i.e. so that it in cross- section forms a reversed U. In order to define various directions and planes more easily, a coordinate system with xyz-directions has been included in the drawings, where x represents longitudinal direction, y latitudinal direction and z perpendicular direction or vertical direction in a vehicle body structure, e.g. a motor vehicle. As is apparent from Fig. 1, the longitudinal beam 1 is provided with a recess 13 which is arranged in one side wall 6 of the beam. In the shown example, the recess is rectangular and discloses a shape and dimensions, which are adjusted according to the cross-section of the cross beam so that this can be accommodated in the recess. This is limited by two side edges 14 of the side wall 6, from which a connecting flange 15 projects transversely on both sides of the recess, which connecting flange is intended for connection to the respective side wall 4, 5 in the transversal beam 2, which shall be described more in detail hereinafter. The recess 13 is additionally limited by a lower edge which is formed by means of a connecting flange 16, which is constituted by a projection from the transverse wall of the beam 1 and is intended for connection to the underside of the transverse wall 10 in the cross beam 2. In one end section thereof, the cross beam 2 discloses two connecting flanges 17, which project sideways from one side wall 4, 5 each of the cross beam and are situated in a joint plane which forms a connecting plane for the cross beam. The two connecting flanges 15 of the longitudinal beam, which protrude from the side wall 6, form together with the side walls 4, 5 of the cross beam a connecting surface each which extend in yz-direction, whereas the lower connecting flange 16 in the longitudinal beam 1 together with the underside of the transverse wall 10 in the cross beam 2 form connecting surfaces in xy-direction. The two connecting flanges 17 in the cross beam 2 form together with the second side wall 7 in the longitudinal beam 1 connecting surfaces in xz-direction. As is apparent from Fig. 1, the longitudinal beam 1 and the cross beam 2 have a respective explicit essential extension, more precisely x-direction and y-direction, respectively, whereas the beam foot 3 has a more complex structure, even though its essential extension outwards from the beam knot is perpendicular, i.e. z-direction. In fact, the beam foot 3 is essentially L-shaped having two legs which are transversely arranged in relation to each other, where the vertical leg 18 forms a beam connection to a vertical beam which is intended to form part of the vehicle body structure, whereas the second leg 19 is a horizontally directed leg, which forms an anchor section in the beam knot. Accordingly, the two side walls 8, 9 of the beam foot 3 are also essentially L-shaped, as well as the transverse wall 12, which thereby extends in two planes which are transversely arranged in relation to each other and in addition forms a softly bevelled transition section 20, the purpose of which is, among other things, to secure a high degree of rigidity in the beam knot. In the shown example, the beam foot discloses two connecting flanges 21, which are intended to form a connection to a not shown part of the vehicle body structure and at the base disclose a recess which essentially corresponds to the height of the connecting flanges 17 in the cross beam 2. The lying or horizontal part of the side walls 8, 9 form connecting surfaces, which are intended to co-operate with the side walls 4, 5 in the cross beam 2, which likewise form connecting surfaces in connection with one end section of the beam, which extend in yz-direction. In the example which is shown in Fig. 1, a cover plate 22 is also shown, which for example is a floor panel forming part of the vehicle body structure. The cover plate 22 discloses a recess 23 which is intended to accommodate the beam foot 3 including the bevelled section 20. In order to form rest surfaces and connecting surfaces against the cover plate, the cross beam is provided with additional connecting flanges 24 which protrude sideways from the side walls 4, 5 of the beam. Furthermore, the longitudinal beam 1 discloses a connecting flange 25 which is formed by a raised section of the side wall 7, to which a connecting flange 28 on the cover plate 22 is intended to be connected. Thus, in Fig. 2, a practical embodiment of the beam knot according to the invention is shown in assembled state where the included beam elements are slightly modified in their design in relation to the example according to Fig. 1. However, corresponding parts have the same reference numerals as in Fig. 1. The beam knot according to the invention is assembled by means of the fact that one end section of the second beam element 2 is situated inside the first beam element 1, more precisely so, that the end section is inserted through the recess 13, see Fig. 1, and connects to the side wall 7 in the first beam element. In this regard, the two connecting flanges 16 are caused to bear against the inside of the side wall 7 in joint connecting surfaces essentially in a joint xz- plane, and are attached to said inside by means of, for example, spot welding. In this regard, the connecting flanges 15 of the first beam element connect to the outside of the side walls 4, 5 of the second beam element and are attached to these in respective connecting surfaces in a respective yz-plane by means of, for example, spot welding. In this regard, the base of the second beam element, i.e. the transverse wall 10, rests against the inside of the base of the first beam element, i.e. its transverse wall 11, as well as the protruding connecting flange 16, see Fig. 1, and may, in the joint connecting surfaces which have been formed, be attached here as well, for example by means of spot welding, if a high-strength connection is required. Next, the third beam element 3, i.e. the beam foot, is placed inside the second beam element 2, which involves that the beam foot is partly situated inside the first beam element as well and that one of its legs 18 is inserted into the second beam element. Thus, in this regard, the side walls 8, 9 in the horizontal leg of the beam foot bear against the inside of the side walls 4, 5 in the second beam element and are attached to these on a required number of places along the joint connecting surfaces. Thus, parts of the side walls of the third beam element are overlapping, i.e. they overlap parts of the side walls of the second beam element. The profile form of the beam foot is selected so that it forms a reversed U, whereas the first and the second beam element in cross-section form a U turned the right way round. In the shown example according to Fig. 2, an additional beam 29 is also shown, which forms part of the vehicle body structure and connects to the upwardly directed leg 19 of the beam foot by means of the fact that it inserts into this. By means of, for example, spot welding, the beam 29 can be attached to the beam foot in overlapping surfaces. The beam 29 discloses connecting flanges 30 which by means of, for example, spot welding are intended to be attached to a cover plate 31, in the shown example a wheel housing, forming part of the structure. The cover plate 31 connects to the outside of the side wall 7 of the first beam element 1 and is attached to this by means of, for example, spot welding. In the example according to Fig. 2, the first beam element is curved in order to adjust to the form of the cover plate 31 and discloses a connecting flange 32 at the upper edge of its side wall 6, which connecting flange is intended to support a cover plate 22 together with the upwardly turned connecting flanges 24 of the second beam element, which is shown in Fig. 1. To sum up, the beam knot according to the invention has the following construction: the longitudinal side beam discloses a recess in the interior side wall; the cross beam inserts into the side beam and discloses such a width, that the side walls of the cross beam bear against the edges of the recess; the cross beam extends right up to the exterior side wall of the longitudinal beam and is mounted in this; the vertical beam discloses such a width, that the side walls of the vertical beam bear against the side walls of the cross beam; the vertical beam extends right up to the transverse wall of the cross beam and is mounted in this; and the exterior part of the vertical beam extends towards the exterior side wall of the longitudinal beam. One essential feature is constituted by the fact that the width of the recess of the longitudinal beam corresponds to (in practice slightly exceeds) the width of either the cross beam or the vertical beam and that the remaining beam is inserted into the beam structure and discloses a width which corresponds to the remaining opening. The invention is not limited to the embodiments which are described above and shown in the drawings. For example, it is possible to arrange the connecting flanges so that they have another location and extension and direction. Furthermore, it is possible that the beam foot is situated in the second beam element even before this is situated in the first beam element. Furthermore, by means of limitation of the length of the flanges 24, it is possible to let the side walls 8, 9 of the beam foot extend on the outside of the side walls 4, 5 of the second beam element. Furthermore, it is possible that the beam elements have another profile form than a U-profile form, for example a box-profile form, but in this regard, it is necessary that at least the first and the second beam element disclose recesses, i.e. a U-profile form in those sections where the other beam elements are situated. Of the shown beam elements, only the beam foot is in practice shown in its entirety, whereas the other beam elements are shown cut off and in practice have a greater extension with a length which is adjusted to the case in question. The beam foot 3 and the upwardly directed beam element 29 can be constructed as one single element. The cover plates 22, 31 and the connecting connecting flanges 24, 25, 32 do not primarily form part of the beam knot and can be replaced by other elements.

Claims: CLAIMS : 1. Beam knot forming part of a vehicle body structure and comprising at least three beam elements ( 1 , 2 , 3 ) , which each discloses two side walls (4-9) which extend with relative intervals and at least one transverse wall (10- 12) which connects said side walls and which beam elements are rigidly connected with each other in the beam knot and protrude from this in respective directions, c h a r a c t e r i z e d i n that a first beam element (1) of said beam elements discloses a recess (13) in one side wall (6) thereof, which recess is limited by two side edges (4), that a second beam element (2) of said beam elements inserts transversely through said recess with a section and is connected with the opposite side wall (7) of the first beam element and discloses a width between its side walls which corresponds to the width of the recess between its side edges, that a third beam element of said beam elements is partly situated in the first beam element and with its side walls (8, 9) is connected with at least the side walls (4, 5) of the second beam element and connects to the opposite side wall of the first beam element. 2. Beam knot according to claim 1, c h a r a c t e r i z e d i n that parts of the side walls (8, 9) of the third beam element overlap parts of the side walls (4, 5) of the second beam element. 3. Beam knot according to claim 2, c h a r a c t e r i z e d i n that the third beam element ( 3 ) inserts into the second beam element (2) so that parts of its side walls (8, 9) connect to and are attached to the side walls (4, 5) of the second beam element. 4. Beam knot according to claim 2, c h a r a c t e r i z e d i n that the profile form of the first and the second beam element (1, 2) is a U turned the right way round, whereas the profile form of the third beam element (3) is a reversed U. 5. Beam knot according to claim 1, c h a r a c t e r i z e d i n that the third beam element (3) is constituted by an essentially L-shaped beam foot having a first leg (18) which extends in the longitudinal direction of the second beam element (2) and a second leg (19) which extends transversely to the first leg and the first beam element ( 1 ) . 6. Beam knot according to claim 1, c h a r a c t e r i z e d i n that the first beam element (1) discloses connecting flanges (15) which form side edges (14) of the recess (13) and extend in the longitudinal direction of the second beam element (2). 7. Beam knot according to claim 1, c h a r a c t e r i z e d i n that the second beam element (2) discloses connecting flanges (17) in the section thereof which inserts into the first beam element (1), said connecting flanges connecting to the side wall (7) in the first beam element ( 1 ) . 8. Beam knot forming part of a vehicle body structure and comprising at least three beam elements (1, 2, 3), which each discloses two side walls (4-9) which extend with relative intervals and at least one transverse wall (10- 12) which connects said side walls and which beam elements are rigidly connected with each other in the beam knot and protrude from this in respective directions in the vehicle's driving direction (x) as well as vertically (z) to the vehicle, as well as sideways (y) transversely to the driving direction, c h a r a c t e r i z e d i n that a first beam element (1) of said beam elements extends in the driving direction (x) and discloses a recess (13) in one side wall (6) thereof, that a second beam element (2) of said beam elements extends sideways (y) transversely to the driving direction and inserts transversely through said recess with a section and is connected with the opposite side wall (7), that a third beam element of said beam elements is partly situated in the first beam element and with its side walls (8, 9) is connected with at least the side walls (4, 5) of the second beam element and extends vertically (z) with a section, that the first and the second beam elements form part of a floor structure in the vehicle body structure, and that the third beam element connects to a side structure of the vehicle body structure.

Inventors: WEIMAN MARTIN, WEIMAN, MARTIN
Applicants: VOLVO PERSONVAGNAR AB, WEIMAN MARTIN, WEIMAN, MARTIN
Application year: 2000
Main classification: B62D23
IPC codes: B62D21, B62D25, B62D27