GB2281720A

GB2281720A - Two part vehicle bumper with upper and lower internal brackets

Info

Publication number: GB2281720A
Application number: GB9418144A
Authority: GB
Inventors: Peter Reutlinger; Eberhard Palmer
Original assignee: Dr Ing HCF Porsche AG
Current assignee: Dr Ing HCF Porsche AG
Priority date: 1993-09-08
Filing date: 1994-09-08
Publication date: 1995-03-15
Anticipated expiration: 2014-09-08
Also published as: DE4330397A1; ITMI941651A0; DE4330397C2; GB2281720B; GB9418144D0; FR2709714A1; IT1273735B; FR2709714B1; ITMI941651A1

Description

2281720 Vehicle Bumper The invention relates to a vehicle bumper, in

particular for motor vehicles, comprising a shaped outer part of thermoplastic synthetic material and a shaped inner part of synthetic material, the outer part and the inner part being assembled to form at least over part of their length a closed hollow profile to be attached to an adjacent vehicle body part.

In a known bumper of this type (DE 27 08 856 C2), both the outer part and the inner part are produced from thermoplastic synthetic material. Components made of such a synthetic material can be painted relatively well and have a good surface quality.

The disadvantage of a bumper composed of two thermoplastic halves is that the mould production times - especially when moulds with slides are required - are relatively long, and that the mould costs are relatively high.

An object of the invention is to provide, in particular for small production runs of motor vehicles, a bumper which in addition to good surface quality, good painting 2 properties and a relatively high energy absorption has a cheaper mould cost and has a shorter mould production time.

The invention provides a vehicle bumper as claimed in Claim 1.

The advantages which are chiefly achieved by a vehicle bumper in accordance with the invention can be seen from the fact that the combination of outer part of thermoplastic synthetic material and inner part at least in some sections of thermosetting synthetic material produces a bumper which can be painted easily in the visible region and has a visually perfect outer surface, and which has a high energy absorption capacity.

Preferably, upper and lower adapter parts, preferably of thermoplastic synthetic material, are arranged in-between respective upper and lower portions of the bumper and are each connected to both the upper and outer parts. Consequently, a simple mould without slide can be used for the outer part, which can be produced in a short time and cheaply.

The adapter parts of thermoplastic synthetic material can be connected in a simple manner to the outer part of thermoplastic synthetic material by welding (resistance 3 welding) or the like. The connection of the different synthetic materials is intentionally moved inwardly from the visible outer part, so that any rippling or conspicuous fault which might occur because of the different coefficients of expansion is not visible from the outside.

An embodiment of the invention will now be described with reference to the accompanying drawings, wherein:

Fig. 1 is an exploded perspective view of the individual parts of a bumper for a motor vehicle, Fig. 2 is a vertical section, along the longitudinal centre plane A-A of Figure 1 on an enlarged scale, of the bumper attached to a vehicle, and Fig. 3 is a partial plan view, in the direction of the arrow R of Fig. 2, of the inner part of the bumper without the upper adapter part, and on a reduced scale.

In the drawings, a bumper 1 to be mounted on the front or rear of a motor vehicle, in particular a car, comprises an outer part 2 profiled to be approximately C-shaped and an inner part 3. The outer part 2, which is produced from thermoplastic synthetic material (e.g. PP-EPDM), has an inwardly-stamped recess 5 in the region 4 of a receiving portion 4 for a registration number plate.

Outer part 2 and inner part 3 are assembled to form a closed hollow profile 6 at least through part of the length of the bumper.

The bumper, according to Fig. 1, is supported on an adjacent body 8 of a motor Vehicle by means of two spaced impact absorbers or impact tubes 7.

A plate-shaped end region of the impact absorber or tube 7 remote from the body 8 is here connected to the inner part 3 by means of screws (not shown).

The inner part 3 is of thermosetting synthetic material (e.g. S-RIM), at least over a substantial part of its length. The inner part 3 may be constructed either in one piece or from a plurality of parts.

According to Fig. 2, relatively small-surfaced adapter parts 11, 12 are inserted at upper and lower edge regions 9, 10, respectively, of the bumper 1 and are connected to both the inner part 3 and to the outer part 2. Both adapter parts 11, 12 are produced from thermoplastic synthetic material (e.g. PP-EPW).

The lower adapter part 12 is profiled to be approximately L-shaped and is connected to the inner side 13 of the outer part 2 by adhesion, welding or the like. The adapter part 12 forms a pre- fabricated constructional unit 14 with the outer part 2. One leg 15 of the adapter part 12 bears against the inner side 13 of a portion of the outer part 2 and extends in the same direction, whereas the other leg 16 extends vertically upwards in the direction of the inner part 3.

Sheet-metal nuts 18, into which securing screws 19 for connecting inner part 3 and adapter part 12 are screwed, are placed locally onto the free end 17 of the leg 16.

The described detachable connection enables the different synthetic materials to be separated again and recycled in a simple manner.

The upper adapter part 11 forms a pre-fabricated constructional unit 20 with the inner part 3, the adapter part 11 and inner part 3 being connected to one another by riveting, screwing, adhesion or the like.

The angle bracket-shaped upper adapter part 11 bears by means of a horizontal web 21 partially over its length against the outer side 22 of a flange 23 of the inner part 3 extending in the same direction. The substantially horizontally aligned flange 23 has along 6 one edge an integrally shaped portion 24 extending upwards and obliquely with respect to the body 8 and spaced therefrom.

In the case of extreme heat action thereon resulting in softening, the outer part 2 will be supported by the integrally shaped part 24 or a support (not shown) mounted thereon.

The integrally shaped part 24 further provides better transmission of force from the outer part 2 via the inner part 3 to the body 8 (pile test).

A vertical web 25 of the adapter part 11 extends upwardly from the horizontal web 21 and has an end offset angled portion 26 securely connected to the inside 27 of the outer part 2 by adhesion, welding or the like. The connection of two thermoplastic synthetic materials is preferably effected by resistance welding.

Triangular reinforcement ribs 28 are provided locally between the horizontal web 21 and the vertical web 25.

A shaped closure part 30 of thermosetting synthetic material (e.g. S-RIM), which forms a closed box-type support 31 together with the inner part 3, is placed onto the shaped inner part 3 in a central vertical 7 portion thereof. The closure part 30 is connected to the inner part 3 and positioned in front thereof by riveting, adhesion or the like.

According to Fig. 2, the closure part 30 - as seen in cross-section - has upper and lower vertical end wall portions 32, 33 which abut wall portions of the inner part 3 extending in the same direction. In between the end wall portions 32, 33, the closure part 30 is constructed in a corrugated manner. The corrugated portion 34 extends generally in the same direction as a through-shaped outwardly stamped portion 35 of the inner part 3. The outwardly stamped portion 35 faces the body 8.

The connection of thermoplastic synthetic material and thermosetting synthetic material is inside the visible outer surface of the outer part 2 and is provided between the adapter parts 11, 12 and the inner part 3. Any rippling which occurs as a result of the different coefficients of expansion of the synthetic materials used is thus not visible from the outside.

As a result of the interposed adapter parts 11, 12, expensive moulds provided with slides for the outer part 2 can be dispensed with, so that the production times for the moulds and the cost are substantially reduced.

8 The inner part 3 and the adapter part 11 are connected to one another locally by rivets 36.

In the vehicle longitudinal centre plane A-A, circular openings 37, 38 are provided on the adapter part 11 and on the inner part 3 (flange 23), respectively, and have diameters D, D1 corresponding approximately to the shaft diameter d of the rivet 36.

For the other rivet connections arranged remote from the vehicle longitudinal centre plane A-A, the diameters D of the openings 37 in the adapter part 11 and the shaft diameter d of the rivet 36 are approximately the same size. The openings arranged at a spacing from the vehicle longitudinal centre plane A-A are constructed on the inner part 3 as elongate slot openings 381 having a longer length B than the shaft diameter d of the rivet 36. As a result, different expansions of the outer part 2, the adapter part 11 and the inner part 3 can be compensated in a simple manner.

9

Claims

1. A vehicle bumper comprising a shaped outer part of thermoplastic synthetic material and a shaped inner part of synthetic material, the outer part and the inner part being assembled to form at least over part of their length a closed hollow profile to be attached to an adjacent vehicle body part, wherein the inner part is at least in some portions thereof of thermosetting synthetic material, and the connection of thermoplastic synthetic material and thermosetting synthetic material is at a point remote from the visible outer surface of the bumper.

2. A bumper according to Claim 1, wherein upper and lower adapter parts are arranged in-between respective upper and lower portions of the bumper and are each connected to both the inner and outer parts.

3. A bumper according to Claim 2, wherein the adapter parts are formed from thermoplastic synthetic material.

4. A bumper according to Claims 1 to 3, wherein the lower adapter part is substantially L-shaped and is connected to the inner side of the outer part by adhesion, welding or the like and forms a pre-fabricated constructional unit therewith.

5. A bumper according to any one of the preceding claims, wherein the upper adapter part is arranged on an outer surface of the inner part and is connected thereto by riveting, screwing, adhesion or the like.

6. A bumper according to Claim 5, wherein the upper adapter part forms a pre-fabricated constructional unit with the inner part and is connected to the inside of the outer part by adhesion, welding or the like.

7. A bumper according to any one of the preceding claims, wherein a shaped closure part of thermosetting synthetic material forming a closed box support with the inner part is arranged on the inner part in a central upright portion thereof.

8. A bumper according to Claim 7, wherein the inner part and the closure part are connected to one another by riveting, adhesion or the like.

9. A bumper according to Claim 2 or any one of Claims 3 to 8 dependent on Claim 2, wherein the upper adapter part and the inner part are connected to one another by rivets, a secure rivet connection being effected between adapter part and the inner part in a longitudinal centre plane thereof, and in the region of the other rivet connections elongate slot openings extend along the 11 inner part and have a length longer than the diameter of n the shaft of the rivets provided on the inner part.

10. A vehicle bumper substantially as herein described with reference to the accompanying drawings.

11. A vehicle having a vehicle bumper as claimed in any one of the preceding claims.