Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
  • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
  • B60R21/13—Roll-over protection
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D7/00—Bending rods, profiles, or tubes
  • B21D7/06—Bending rods, profiles, or tubes in press brakes or between rams and anvils or abutments; Pliers with forming dies
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
  • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
  • B60R21/13—Roll-over protection
  • B60R2021/132—Roll bars for convertible vehicles

Definitions

• the present invention concerns shaping of a roll-over tube, more specifically roll-over bars for a vehicle, and furthermore a roll-over bar which either can retract into a housing with a mechanism that allows for a mainly U-shaped section of the roll-over tube to assume a retracted, passive position within the housing, and an extended, active position where the tube extends over the housing and provides roll-over protection for the open vehicle, or being a part of a permanently mounted roll-over bar system
• the invention furthermore concerns a process for the manufacture of such a roll-over bar
• the invention also concerns use of such a roll-over bar
• a further object is to provide a cost-favourable manufacturing process compared with other manufacturing processes, for example known processes based on the welding of tube-shaped leg sections and an upper top-bridge
• Another object of the invention is to provide a roll-over bar which gives a better security performance compared to the welded, previously known U-shaped roll-over bars
• Still another object of the invention is to provide a process that provides a U-shaped roll-over bar where the shape of the top-bridge can be varied, while at the same time maintaining the structural strength properties improving these particularly in relation to the previously known welded roll-over bars
• the benefits that are obtained from a roll-over bar formed in such a manner can be summarised as follows, particularly in comparison to welded roll-over bars:
• the roll-over bar can take larger deformation specifically in tests for roll-over bars (roof compression test and longitudinal tension test) than the welded U-shape can take This particularly holds true on the bar side under tension in the roof compression test due to the geometry of the bend When the material is under tension, there is material in the indentation which is able to be pulled/stretched out so that in the first pass (production step) the material itself is not strained through a reduction in cross-section
• the roll-over bar can more easily be integrated with other car parts, for example seats or headrests, than the corresponding bars consisting of round welded tubing This can be achieved for example by making the stem taller.
• bent roll-over bars can be used as permanently fixed roll-over bar systems as well as active systems
• the present invention also provides a manufacturing method as defined in patent claim 5, comprising the following steps-
• a tool is placed on each side of the tube's mid-section for clamping and indentation of the tube's side areas, simultaneously with or followed by a tool indenting or bending in the "bending side” of said mid-section c) A tool is applied being inserted into the track formed in the mid-section on the "bending side", for supporting the tube's mid-section in the in-bent track, simultaneously with the tool being divided for its removal after the bending operation
• steps b) and c) could be interchanged so that the first step is to form the track 3c and then forming the side areas of the mid-section of the tubes (3a, 3b) This procedure may be advantageous due to less strain of the material during forming the mid-section area
• Geometric design of the tube can ensure varying cross-sections by varying the indentation
• the indentation can be varied as much as possible optimally with respect to shape and function
• Tube member can be shaped with a small bend radius, something which is otherwise difficult to obtain
• Fig 1 is a schematic side view of the upper portion of an exemplified
• Fig 2 is a section taken along line A-A in Fig 1
• Figs 3A, 3B show respectively a top view of a tube-shaped member inserted in a pressing tool, and a segment side view of the tube-shaped member, which may represent a first step of the production embodiment of the shaping process according to the invention
• Figs 4A.4B show respectively, like Figs 3A and 3B, a top and side view of a second step in the shaping process, namely the indentation of the side areas of the member's mid-section
• Figs 5A, 5B show respectively, like Figs 4A and 4B, a top and side view of the member during a third step in the shaping process according to the invention, where a tool for the inward bending of the bending side of the mid-section of the member is inserted and functions between parts of the pressing tool
• Fig 6 is a side view, partially a sectional view that shows a fourth step in the shaping process according to the invention, where a divisible tool is inserted into the track formed on the bending side of the mid-section in order to support the member's mid-section while the tube-shaped member is bent into the final U-shape by means of a bending tool (not shown)
• a bending tool (not shown)
• Fig 1 an example is shown of a finished U-shaped bent roll-over tube manufactured according to the present invention
• the bent tube or the finished roll-over bar 1A has been manufactured starting from an integral, straight piece of tubing 1 with a given material thickness, i e with an appropriate external and respectively internal diameter D
• the straight piece of tubing (member) 1 will upon appropriate bending into a U-shape be characterised by being manufactured in one piece avoiding welded parts, something which will in turn reduce the danger of fracture
• the tube member 1 which both before and after bending comprises two outer sections 2a and 2d, respectively, and a mid-section 2c, first has its middle section 2c processed by appropriate tools, where the mid-section 2c partly by indentation of side areas 3a and 3b, and partly by an inward bending 3c of the bending side 3, will assume an in-bent shape as it appears in Fig 2
• An appropriate tool will act upon the bending side 3 of the mid-section 2c in order to form an inward-directed indentation, in that the degree of this indentation can be determined based on which final shape, extent and final dimensions the mid-section 2c needs to have
• the bending of the legs 2a and 2b of the tube member can be appropriately performed by cradle-shaped tools that press the end sections of the tube into the final U-shape, simultaneously with the two halves of the tool placed in the track or indentation 3 of mid-section 2c giving good support of the mid-section during this bending process
• the two halves of the tool can then be split apart and removed upon finalising the bending into the final U-shape
• Figs 3A, 3B, 4A, 4B and 5B along with Fig 6 different steps are shown in a preferred mode of operation for shaping of a U-shaped roll-over tube for use in a roll-over bar
• Figs 3A and 3B show respectively a top view of a tube member 1 inserted into a pressing tool 10a and 10b, and a segment of a side view of the tube member 1 , which may represent a first step in the production method according to the invention
• the shaping process preferably can start from a substantially hollow tube-shaped member with an external diameter D, but it should be understood that other hollow members that can be defined as tube-shaped can also be used, all depending upon the final design of the finished bent U-shaped roll-over bar
• Figs 4A and 4B show respectively, like Figs 3A and 3B, a top view and a side view of a second step in the shaping process, namely indentation of side areas 3a and 3b of the member's mid-section to a narrower width B than the original diameter D
• a two-part tool 10a and 10b is placed on each side of the mid-section 3 for clamping and pressing in of side areas 3a and 3b, simultaneously with or after which a tool 11 indents or bends in "the bending side" 3c of said mid-section 3 to a dimension H that can be larger, equal to or less than the original diameter D
• a tool 12a and 12b is used which is inserted into the track or indentation formed in the "bending side" 3c to support the tube's mid-section in the in-bent track 3c, while at the same time the tool is divided, 12a and 12b, in order to facilitate removal after bending
• the divided tool 12a and 12b that is inserted into the in-bent track 3c formed in the mid-section 3 being made with rounded end sections 13a and 13b, which end sections 13 and 13b after the bending of the piece to the final U-shape are surrounded by the said in-bent track 3c at an angle of more than 90°, and up to approx. 180°.
• the divided tool comprising two mandrel-like elements 12a and 12b with an intermediate locking mechanism may be utilised.
• two bending tools can also be used, one on each side of the mid-section 3, for example, cradle-shaped tools which press the end sections 2a and 2b of the tube into the final U-shape simultaneously with the top-bridge 2c having retained the in-bent profile 3a, 3b and 3c.
• middle bridge section 2c it is advantageous for the middle bridge section 2c to exhibit substantially uniform cross-section along its longitudinal extent, however variations in the extent of the bending can also be contemplated here.
• the shape of the mid-section 2c which constitutes the top-bridge of the final U-shape of the roll-over bar 1 A can be varied within broad limits, in that it must be understood that the width B of the mid-section or the top-bridge 2c shown in Fig. 2 can have a smaller dimension than the original external diameter D shown in Fig. 1. Consequently, there will occur between the top-bridge 2c and each of the legs 2a and 2b a transition section, 4a and 4b respectively, but since the piece for the finished roll bar 1 is formed from a single piece, these transition sections 4a and 4b will be free of welds and compared to welded joints exhibit an increased reliability bridge 2c and the associated leg sections 2a and 2b.
• the in-bent material 3c in the top-bridge 2c can sustain more deflection than a corresponding top section made by ordinary fitting and welding, which gives an increased safety upon the turn-over of the vehicle in which the roll-over bar is installed.
• a roll-over bar 1A according to the present invention will also more easily be able to be integrated into a headrest, since the dimensions of the top-bridge can more easily be adjusted for the different versions of headrests, while at the same time the resistance to fracture can be improved compared to previously known roll-over bars.

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19899551

Family Applications (1)

Country Status (4)

Cited By (2)

Citations (6)

Family Cites Families (2)

• 1996
  • 1996-06-20 NO NO962621A patent/NO962621D0/no unknown
• 1997
  • 1997-06-20 DE DE19781835A patent/DE19781835B4/de not_active Expired - Lifetime
  • 1997-06-20 AU AU32779/97A patent/AU3277997A/en not_active Abandoned
  • 1997-06-20 DE DE19781835T patent/DE19781835T1/de active Pending
  • 1997-06-20 WO PCT/NO1997/000158 patent/WO1997048506A1/en active Application Filing

Patent Citations (6)

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