GB2437745A

GB2437745A - Brake disc manufacture

Info

Publication number: GB2437745A
Application number: GB0608857A
Authority: GB
Inventors: Simon Sharp
Original assignee: HOPE TECHNOLOGY
Current assignee: HOPE TECHNOLOGY
Priority date: 2006-05-05
Filing date: 2006-05-05
Publication date: 2007-11-07
Also published as: GB0608857D0

Abstract

A manufacturing process is described for producing ventilated brake discs. First 10 and second 20 braking elements are provided, and a plurality of fins 32 fixed in place between the first and second braking elements (fig 2) to couple the first and second braking elements to one another. The fins maybe provided on a fin carrying blank 34a and b for arrangement with the braking elements 10 and 20. Vacuum brazing is preferably used to couple the components in the brake. Using the manufacturing process described relatively thin ventilated brake discs can be produced.

Description

IMPROVEMENTS IN AND RELATING TO BRAKE DISCS

Field of the Invention

The present invention relates to brake discs, in particular but not exclusively to brake discs suitable for use in brakes for vehicles such as bicycles, motorcycles, scooters and the like. The present invention also relates to blanks for use in the manufacture of brake discs, to kits of parts for use in the manufacture of brake discs, and to brake disc manufacturing processes.

Background to the Invention

Typically, metallic materials are used for brake discs (also known as brake rotors) for vehicles. In particular, casting brake discs from grey iron gives suitable hardness, chemical composition, tensile strength and other properties for most standard vehicle brake discs without incurring high manufacturing costs. Casting techniques have been developed which enable production of ventilated discs, in which two opposed braking elements each carrying a braking surface are maintained a small distance away from one another by fins (also known as vanes) . In a ventilated disc, heat dissipation from the braking surfaces into air in the space defined between the fins and between the braking elements helps to reduce heat build up in the disc when the disc is used for braking.

However, the casting techniques used to produce conventional ventilated discs can not easily be scaled down to produce ventilated discs of small thickness. It is an aim of preferred embodiments of the present invention to overcome at least one disadvantage of the prior art, whether referred to herein, or otherwise.

Summary of the Invention

According to a first aspect of the present invention there is provided a brake disc manufacturing process, comprising: (a) providing first and second braking elements; (b) providing a plurality of fins; (c) arranging the fins in place relative to the first and second braking elements; and (d) fixing the plurality of fins in place with the first and second braking elements to thereby couple the first and second braking elements.

Suitably, in step (d) the fins are fixed in place with the first and second braking elements by a brazing process.

Preferably in step (d) the fins are fixed in place with the first and second braking elements by a vacuum brazing process.

Suitably, the plurality of fins provided in step (b) comprise elements of a blank, the blank comprising a plurality of fins carried on a fin carrier. Suitably, the step (c) comprises arranging the blank between the braking elements.

Suitably, the blank is in the form of a ring. Suitably, the blank is substantially circular. Suitably, the blank is substantially planar. Suitably, the carrier comprises a first carrying portion coupled to a first end portion of one or more fins in the plurality of fins. Suitably, the carrier comprises a second carrying portion coupled to a second end portion or one or more fins in the plurality of fins. Suitably, all fins in the plurality of fins are coupled to the first and/or second carrying portion.

Suitably, the braking elements provided in step (a) are in the form of ring of material with an inner edge and an outer edge. Suitably, the ring is substantially circular.

Suitably, the ring is substantially planar. Suitably, the braking elements provided in step (a) are provided with a plurality of cooling passageways extending therethrough.

Suitably, the braking elements provided in step (a) comprises one or more mounting portions. Suitably, the, or each of the mounting portions comprise(s) a mounting passageway extending therethrough.

Suitably, the first and second carrying portions of the blank are maintained apart by the fins at a distance greater than the distance separating the inner and outer edges of the braking elements provided in step (a), such that when the fins are arranged with the braking elements in step (c) the first and second carrying portions extend beyond the inner and outer edges of the braking elements respectively.

Suitably, the step (c) comprises arranging the fins such that the fins do not impinge on the cooling passageways of the braking elements.

Suitably, the blank provided in step (b) comprises one or more mounting portions. Suitably, the, or each of the mounting portions comprise(s) a mounting passageway extending therethrough. Suitably, the step (c) comprises aligning the blank with the braking elements using the mounting portions on the blank and on the braking elements. Suitably, the step (c) comprises aligning the blank with the braking elements using the mounting passageways on the blank and on the braking elements.

Suitably, the method further comprises the step (e) of separating the fin carrier from the fins. Suitably, the step (e) comprises cutting, preferably laser cutting the fin carrier from the fins.

Suitably, the method further comprises the step (f) of machining, preferably grinding, the braking elements to provide braking surfaces separated by a predetermined distance.

Suitably, the steps (c) -(e) are performed in sequence as per alphabetical order.

According to a second aspect of the present invention there is provided a brake disc manufactured according to the manufacturing process of the first aspect of the present invention.

According to a third aspect of the invention there is provided a blank for use in the manufacture of a brake disc, substantially as the blank described for use in the first aspect of the invention.

According to a fourth aspect of the invention there is provided a kit of parts for use in the manufacture of a disc brake, the kit comprising a blank and at least one braking element substantially as the blank and braking element described for use in the first aspect of the invention.

Brief Introduction to the Drawings

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which: Figure 1 shows a side view of first and second braking elements, along with a blank according to an embodiment of the present invention; Figure 2 shows a side view of the first and second braking elements and blank of Figure 1 arranged in place with one another during a brake disc manufacturing process according to an embodiment of the present invention; and Figure 3 shows a side view of a brake disc manufactured from the components shown in Figure 1 and using a manufacturing process according to an embodiment of the present invention.

Description of Preferred Embodiments

Figure 1 shows a side view of first and second braking elements 10,20, along with a blank 30 according to an embodiment of the present invention. The use of the first and second braking elements 10,20 and the blank 30 in a process for manufacturing a brake disc will now be described in more detail.

The first and second braking elements 10,20 are suitably formed by a laser cutting process by cutting a ring-like shape from a piece of substantially planar sheet of metallic material. The first and second braking elements comprise an inner edge 17 and an outer edge 18, with an unfinished braking surface 11 therebetween. The first and second braking elements 10,20 have cooling passageways 14 extending therethrough. The first and second braking elements 10,20 comprise four mounting portions 15 extending radially inwards from the inner edge 17, each of which comprises a mounting passageway 16 extending therethrough.

The blank 30 comprises a plurality of fins 32 carried on a fin carrier made up from a first carrying portion 34a and a second carrying portion 34b. The first and second carrying portions 34a,34b of the blank are maintained apart by the fins 32 at a distance greater than the distance separating the inner edge 17 and outer edge 18 of the first and second braking elements 10,20 The blank 30 also comprises four mounting portions 35, arranged to correspond with the mounting portions 15 of the first and second braking elements 10,20. The mounting portions 35 of the blank 30 each comprise a mounting passageway 36 extending therethrough.

To manufacture the brake disc 1, shown in Figure 3 the blank 30 is positioned between the first and second braking elements 10,20, and the three components are aligned and held by a fixture (not shown), preferably using the mounting portions 15,35 and/or the mounting passageways 16, 36.

The assembly comprising the first and second braking elements 10,20 and the blank 30 is then put through a vacuum brazing process to fix the components of the brake disc to one another. After the components have been arranged with one another as described, a partially complete brake disc assembly as shown in Figure 2 is S produced.

As demonstrated by Figure 2, the blank 30 is shaped so that the fins 32 extend beyond the inner edge 17 of the first and second braking elements 10,20. Furthermore as the first and second carrying portions 34a,34b of the blank 30 are maintained apart by the fins 32 at a distance greater than the distance separating the inner and outer edges 17,18 of the first and second braking elements 10,20 it is possible in this arrangement for the first and second carrying portions 34a,34b to extend beyond the inner edge 17 and outer edge 18 of the braking elements 10,20 respectively.

It is to be noted that the arrangement of the fins 32 and cooling passageways is chosen such that the fins 32 do not impinge on the cooling passageways 14 of the first and second braking elements 10,20 when the blank 30 is arranged with the first and second braking elements 10,20.

This can improve the strength and heat dissipation properties of the brake disc 1 produced.

Next, the fin carriers 34a,34b are separated from the fins 32. This separation can be conveniently performed using a laser cutting technique. It is also to be noted that there are no impediments to air movement in the spaces between the fins 32, once the fin carriers 34a,34b have been separated from the fins 32.

The braking surfaces 11, can then be ground or otherwise machined to a desired smoothness and overall brake disc thickness, and other finishing steps performed such as chamfering the inner and/or outer edges 17,18 of the brake disc 1 to provide the finished brake disc 1.

It will be appreciated that by providing other arrangements of fins, cooling passageways and mounting portions, a range of discs having desired strength, sizes, mounting and heat dissipation characteristics can be produced.

By using the abovementioned apparatus and techniques a very thin vented brake disc can be easily manufactured to accurate tolerances. In particular, the small dimensions (in particular thickness), low weight and good heat dispersal properties are possible for brake discs manufactured according to processes of preferred embodiments of the present invention. Such brake discs may be of particular use for use in the brakes of relatively small vehicles, such as bicycles, motorcycles, scooters and the like.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s) . The invention extends to any novel one, or any novel combination, of the features

disclosed in this specification (including any

accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

Claims: 1. A brake disc manufacturing process, comprising: (a)

providing first and second braking elements; (b) providing a plurality of fins; (c) arranging the fins in place relative to the first and second braking elements; and (d) fixing the plurality of fins in place with the first and second braking elements to thereby couple the first and second braking elements.

2. The process of claim 1, wherein in step (d) the fins are fixed in place with the first and second braking elements by a brazing process.

3. The process of claim 2, wherein in step (d) the fins are fixed in place with the first and second braking elements by a vacuum brazing process.

4. The process of any preceding claim, wherein the plurality of fins provided in step (b) comprise elements of a blank, the blank comprising a plurality of fins carried on a fin carrier.

5. The process of claim 4, wherein the step (c) comprises arranging the blank between the braking elements.

6. The process of claim 4 or 5, wherein the blank is in the form of a ring.

7. The process of claim 4, 5 or 6, wherein the carrier comprises a first carrying portion coupled to a first end portion of one or more fins in the plurality of fins.

8 The process of claim 4, 5, 6 or 7 wherein the carrier comprises a second carrying portion coupled to a second end portion or one or more fins in the plurality of fins.

9. The process of claim 7, or of claim 8 as dependant on claim 7, wherein all fins in the plurality of fins are coupled to the first and/or second carrying portion.

10. The process of any preceding claim, wherein the braking elements provided in step (a) are in the form of ring of material with an inner edge and an outer edge.

11. The process of any preceding claim, wherein the braking elements provided in step (a) comprises one or more mounting portions.

12. The process of claim 11, wherein the, or each of the mounting portions comprise(s) a mounting passageway extending therethrough.

13. The process of claim 8 as dependent on claim 7, wherein the first and second carrying portions of the blank are maintained apart by the fins at a distance greater than the distance separating the inner and outer edges of the braking elements provided in step (a), such that when the fins are arranged with the braking elements in step Cc) the first and second carrying portions extend beyond the inner and outer edges of the braking elements respectively.

14. The process of any preceding claim, wherein the braking elements provided in step (a) are provided with a plurality of cooling passageways therethrough, and wherein the step (c) comprises arranging the fins such that the fins do not impinge on the cooling passageways of the braking elements.

15 The process of any preceding claim as dependent on claim 4, wherein the blank provided in step (b) comprises one or more mounting portions.

16. The process of claim 15, wherein the, or each of the mounting portions comprise(s) a mounting passageway extending therethrough.

17. The process of claim 15 or 16 as dependent on claim 11, wherein the step (c) comprises aligning the blank with the braking elements using the mounting portions on the blank and on the braking elements.

18. The process of any preceding claim further comprising the step (e) of separating the fin carrier from the fins.

19. The process of any preceding claims further comprising the step (f) of machining the braking elements to provide braking surfaces separated by a predetermined distance.

20. The process of claim 18, wherein the steps (c)-(e) are performed in sequence as per alphabetical order.

21. A brake disc manufactured according to the manufacturing process of any preceding claim.

22. A blank for use in the manufacture of a brake disc, the blank comprising a plurality of fins carried on a fin carrier.

23. The blank of claim 22, in the form of a ring.

24. The blank of claim 22 or 23, wherein the carrier comprises a first carrying portion coupled to a first end portion of one or more fins in the plurality of fins.

25. The blank of claim 22, 23 or 24, wherein the carrier comprises a second carrying portion coupled to a second end portion or one or more fins in the plurality of fins.

26. The blank of claim 24 or 25, wherein all fins in the plurality of fins are coupled to the first and/or second carrying portion.

27. The blank of any one of claims 22-26, wherein the blank provided in step (b) comprises one or more mounting portions.

28. The blank of claim 27, wherein the, or each of the mounting portions comprise(s) a mounting passageway extending therethrough.

29. A kit of parts for use in the manufacture of a disc brake, the kit comprising a blank and at least one braking element, the blank as claimed in any one of claims 22-28.

30. A brake disc manufacturing process, blank or kit substantially as herein described, with reference to the accompanying drawings.