GB2078636A

GB2078636A - A road wheel for a vehicle

Info

Publication number: GB2078636A
Application number: GB8015599A
Authority: GB
Original assignee: COMPETITION WHEELS Ltd
Current assignee: COMPETITION WHEELS Ltd
Priority date: 1980-05-12
Filing date: 1980-05-12
Publication date: 1982-01-13
Also published as: GB2078636B

Abstract

A wheel has a rim and hub joined by a wheel disc or spokes, and comprises first and second cast wheel components (10, 16) machined after casting, the first component (10) forming a part (12) of the wheel rim, the hub (13) and the disc or spokes (14), and the second component 16 forming the remainder of the rim. The components (10, 16) are secured together, such as by welding, and may be made of magnesium alloy. <IMAGE>

Description

SPECIFICATION A road wheel for a vehicle This invention relates to road wheels for vehicles and is particularly but not exclusively applicable to wheels used on competition cars, e.g. racing cars.

It is known that it is desirable to reduce the weight of the wheels of a vehicle, especially the wheels of a competition car, in order to improve the ratio of sprung to unsprung weights.

One way to do this is to utilise for the wheel a material having a relatively low density and high strength and aluminium and a magnesium alloy have both been used in the past.

It is known to cast magnesium alloy and aluminium wheels and in this case a wheel is cast and then machined to size. A single die is suitable for a relatively narrow range of width of wheel.

The widths of the wheels used in competition cars vary greatly and thus the cost of providing dies suitable for a wide range of wheel widths is substantial.

According to the invention there is provided a road wheel for a vehicle, having a rim portion and a hub portion joined by one or more generally radially extending members, and comprising first and second cast wheel parts machined after casting, the first wheel part forming a first part of the rim portion of the wheel, the hub portion of the wheel and the generally radially extending member or members of the wheel, and the second wheel part forming a second part of the rim portion of the wheel, the wheel parts being secured together.

Preferably, the rim and hub portions of the wheel are joined by a plurality of generally radially extending spokes forming part of the second wheel part.

Preferably, the wheel parts are secured together by welding.

Advantageously, the first wheel part is one of two such wheel parts made as a single casting.

Conveniently, the first and second wheel parts are cast in a magnesium alloy.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a side sectional elevation on the line A-A of Figure 2 of a casting which is to form a first part of a wheel in accordance with the invention; Figure 2 is an end elevation in the direction of arrow A of Figure 1; Figure 3 is a side sectional elevation of a machined casting which will form a second part of each of two wheels; and Figure 4 is a side sectional view of an assembled wheel.

Referring to Figures 1, 2 and 3, there is shown therein machined castings which are produced from a magnesium alloy or aluminium using the die casting technique, although sand casting could be utilised. The casting shown in Figure 1 forms a first wheel part 10, the wheel having a rim portion and a hub portion joined by a plurality of spokes.

A broken line 11 in Figure 1 indicates the outline of the casting immediately after it has been produced and the full lines indicate the shape of the wheel part after it has been machined.

The part 10 forms a first part 12 of the rim portion of the wheel, the hub portion 13 of the wheel, and the plurality of spokes 14 joining the hub portion to the rim portion of the wheel.

A range of widths of wheel parts can be produced from a given casting and this is illustrated by the full line which in the upper half of Figure 1 illustrates the minimum width of wheel part which can be produced from the casting, whereas the full line in the lower half of Figure 1 illustrates the maximum width of wheel part which can be produced from the casting.

The casting 1 5 shown in Figure 2 will form a second part 1 6 of each of two wheels and the broken line 1 7 indicates the casting immediately after having been produced whereas the full line indicates the shape of the casting after having been machined.

Two wheel parts 1 6 are cut from the casting 1 5 and each forms only a second part of the rim portion of the wheel. The widths of the wheel parts 16 can be varied by adjusting the position of the cut or cuts.

A second wheel part 1 6 is then secured to a first wheel part 10 by welding. Excess weld material is then removed to give the wheel the appearance of a one-piece wheel as shown in Figure 4.

The most suitable material for the castings is a magnesium alloy, aluminium being cheaper and relatively more dense and therefore less suitable.

The spokes 14 of the first wheel part 10 may be replaced by an annular wall which may be dished.

1. A road wheel for a vehicle, having a rim portion and a hub portion joined by one or more generally radially extending members, and comprising first and second cast wheel parts machined after casting, the first wheel part forming a first part of the rim portion of the wheel, the hub portion of the wheel and the generally radially extending member or members of the wheel, and the second wheel part forming a second part of the rim portion of the wheel, the wheel parts being secured together.

2. A wheel as claimed in claim 1, wherein the rim and hub portions of the wheel are joined by a plurality of generally radially extending spokes forming part of the second wheel part.

3. A wheel as claimed in claim 1 or claim 2, wherein the wheel parts are secured together by welding.

4. A wheel as claimed in any one of the preceding claims, wherein the first wheel part is one of two such wheel parts made as a single casting.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A road wheel for a vehicle This invention relates to road wheels for vehicles and is particularly but not exclusively applicable to wheels used on competition cars, e.g. racing cars. It is known that it is desirable to reduce the weight of the wheels of a vehicle, especially the wheels of a competition car, in order to improve the ratio of sprung to unsprung weights. One way to do this is to utilise for the wheel a material having a relatively low density and high strength and aluminium and a magnesium alloy have both been used in the past. It is known to cast magnesium alloy and aluminium wheels and in this case a wheel is cast and then machined to size. A single die is suitable for a relatively narrow range of width of wheel. The widths of the wheels used in competition cars vary greatly and thus the cost of providing dies suitable for a wide range of wheel widths is substantial. According to the invention there is provided a road wheel for a vehicle, having a rim portion and a hub portion joined by one or more generally radially extending members, and comprising first and second cast wheel parts machined after casting, the first wheel part forming a first part of the rim portion of the wheel, the hub portion of the wheel and the generally radially extending member or members of the wheel, and the second wheel part forming a second part of the rim portion of the wheel, the wheel parts being secured together. Preferably, the rim and hub portions of the wheel are joined by a plurality of generally radially extending spokes forming part of the second wheel part. Preferably, the wheel parts are secured together by welding. Advantageously, the first wheel part is one of two such wheel parts made as a single casting. Conveniently, the first and second wheel parts are cast in a magnesium alloy. The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a side sectional elevation on the line A-A of Figure 2 of a casting which is to form a first part of a wheel in accordance with the invention; Figure 2 is an end elevation in the direction of arrow A of Figure 1; Figure 3 is a side sectional elevation of a machined casting which will form a second part of each of two wheels; and Figure 4 is a side sectional view of an assembled wheel. Referring to Figures 1, 2 and 3, there is shown therein machined castings which are produced from a magnesium alloy or aluminium using the die casting technique, although sand casting could be utilised. The casting shown in Figure 1 forms a first wheel part 10, the wheel having a rim portion and a hub portion joined by a plurality of spokes. A broken line 11 in Figure 1 indicates the outline of the casting immediately after it has been produced and the full lines indicate the shape of the wheel part after it has been machined. The part 10 forms a first part 12 of the rim portion of the wheel, the hub portion 13 of the wheel, and the plurality of spokes 14 joining the hub portion to the rim portion of the wheel. A range of widths of wheel parts can be produced from a given casting and this is illustrated by the full line which in the upper half of Figure 1 illustrates the minimum width of wheel part which can be produced from the casting, whereas the full line in the lower half of Figure 1 illustrates the maximum width of wheel part which can be produced from the casting. The casting 1 5 shown in Figure 2 will form a second part 1 6 of each of two wheels and the broken line 1 7 indicates the casting immediately after having been produced whereas the full line indicates the shape of the casting after having been machined. Two wheel parts 1 6 are cut from the casting 1 5 and each forms only a second part of the rim portion of the wheel. The widths of the wheel parts 16 can be varied by adjusting the position of the cut or cuts. A second wheel part 1 6 is then secured to a first wheel part 10 by welding. Excess weld material is then removed to give the wheel the appearance of a one-piece wheel as shown in Figure 4. The most suitable material for the castings is a magnesium alloy, aluminium being cheaper and relatively more dense and therefore less suitable. The spokes 14 of the first wheel part 10 may be replaced by an annular wall which may be dished. CLAIMS

5. A wheel as claimed in any one of the preceding claims, wherein the first and second wheel parts are cast in a magnesium alloy.

6. A wheel for a vehicle, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.