WO1999038712A2

WO1999038712A2 - Procedure for the production of the hub sleeeve of two-wheeled vehicles, especially bicycles

Info

Publication number: WO1999038712A2
Application number: PCT/HU1999/000008
Authority: WO
Inventors: Zoltán FARKAS
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-01-30
Filing date: 1999-01-29
Publication date: 1999-08-05
Anticipated expiration: 2000-07-30
Also published as: WO1999038712A3; HU9800170D0; HUP9800170A1

Abstract

The invention relates to a procedure for the production of the hub sleeve of two-wheeled vehicles, especially bicycles, in the course of which a master blank is produced from a cylindrical base material, e.g.: pipe material, by cutting, and then machined connection zones are created on the ends of the master blank by machining. The characteristic feature of the procedure is that after the cutting at least a part of the external surface (1b) and/or internal surface (1c) of the master blank (1) is covered with a slipping increasing material, then the master blank (1) is clamped in a mould cavity (2a) having one or more forming pockets (2b), and by expanding the two ends (1a) of the master blank (1) with the help of an expansion mandrel (3) by cold extrusion in one or two stages a concave bent rolling unit receiving surface (1e) is created, the master blank (1) provided with a rolling unit receiving surface (1e) is taken out of the tool (2), and the machining is performed only after this, and the machined connection zones are made independently from the further treatment of the rolling unit receiving surface (1e).

Description

Procedure for the production of the hub sleeve of two-wheeled vehicles, especially bicycles

The invention relates to a procedure for the production of the hub sleeve of two-wheeled vehicles, especially bicycles, in the course of which a master blank is produced from a cylindrical base material, e.g. : pipe material, by cutting, and then machined connection zones are created on the ends of the master blank by machining.

Several solutions have become known with respect to the production of the wheel discs and hubs of different vehicles. In patents No. HU 174.572 and HU 176.781 production procedures are described in the course of which, by applying the operations of die forging and pressing in succession, vehicles' integral wheel discs can be produced. In patent No. HU 169.530 a solution is described which relates to the production of hubs and is based on casting.

Machine-cutting technology is also widely used for producing the hubs of two-wheeled vehicles exposed to less strain, especially bicycles and motor-cycles.

However, one of the disadvantages of the known solutions is that the production of the hubs of bicycles and motor-cycles with the traditional technologies is too expensive, its efficiency does not reach the required extent, and especially in the case of machine cutting in large amounts its energy and manual labour demand is significant.

It must also be regarded as a disadvantage that in the case of the known procedures the produced hubs are expensive because of the large energy demand or the significant material loss or the increased manual labour demand.

Our aim with the invention was to overcome the deficiencies of the known solutions and to elaborate a procedure which, with small manual labour and energy investment and with minimal material loss, is suitable for the production of hubs having the appropriate strength characteristics and other physical characteristics.

The invention was based on the recognition that if the two ends of a pipe, the dimensions of which are close to the required dimensions, are expanded in the desired way, then the task can be solved, and after the shape changing the internal surface of the pipe can be provided with functional parts as a result of which the further treatment of the given internal parts becomes unnecessary both from the aspects of surface quality and dimensions.

In accordance with the set aim the procedure for the production of the hub sleeve of two- wheeled vehicles, especially bicycles - in the course of which a master blank is produced from a cylindrical base material, e.g.: pipe material, by cutting, and then machined connection zones are created on the ends of the master blank by machining - is based on that after the cutting at least a part of the external surface and/or internal surface of the master blank is covered with a slipping increasing material, then the master blank is clamped in a mould cavity having one or more forming pockets, and by expanding the two ends of the master blank with the help of an expansion mandrel by cold extrusion in one or two stages a concave bent rolling unit receiving surface is created, the master blank provided with a rolling unit receiving surface is taken out of the tool and the machining is performed only after this, and the machined connection zones are made independently from the further treatment of the rolling unit receiving surface.

A further criterion of the procedure according to the invention may be that the rolling unit receiving surface is made by cold extrusion in one single stage.

In the case of another different version of the procedure the rolling unit receiving surfaces are made in one step at both ends of the master blank.

From the aspect of the invention it is favourable to use extrusion mandrels, brought together, moving opposite each other as expansion mandrels, and to use a minimum 250-ton eccentric press for the cold extrusion.

In the case of another version of the procedure zinc phosphate and oil are used as slipping increasing materials.

The most important advantage of the procedure according to the invention is that with its help hubs of appropriate quality can be produced with more favourable production costs than in the case of the known solutions. It must also be regarded as an advantage that the production procedure can be carried out with traditional means, in a single forming operation, and so its efficiency significantly exceeds that of the known solutions.

It must also be regarded as favourable that due to the technology the manual labour and energy demand is smaller than in the case of the pieces produced by machining exclusively, which may result in further cost decreasing.

Below the procedure according to the invention is described in more detail with the help of the applied tool, in connection with an example, on the basis of a drawing. In the drawing

Drawing No. 1 is the schematic picture of the step needed for the procedure's cold extrusion stage.

Drawing No. 1 is the schematic picture of the 2 tool used for the cold extrusion in the course of the procedure according to the invention and the 1 master blank to be placed in it. On the left of drawing No. 1 the stage before the cold extrusion is shown and on the right the form of the 1 master blank achieved after the cold extrusion can be seen. It can be seen well that the Id central part of the 1 master blank is clamped in the 2a mould cavity of the 2 tool. On the edges of the 2a mould cavity, near the la ends of the 1 master blank there is the 2b forming pocket which gives the final form of the lb external surface in the course of the expansion of the la end of the 1 master blank. In the If centre-line of the 1 master blank, coaxial to it, there is the 3 expansion mandrel which is supposed to expand the part of the lg internal space of the 1 master blank close to its la end and the 3 a forming surface of which is the same as the form to be followed of the le rolling unit receiving surface of the hub to be made from the 1 master blank.

Below the process of the procedure is described with the help of examples.

Example No. 1

In the procedure version according to the example rare bicycle hub was produced, in the course of which as the first step a 1 master blank was produced by cutting up a standard steel pipe, the internal diameter of which is 34.3 mm and the external diameter of which is 42 mm, to get the appropriate dimensions, then the lb external surface and the lc internal surface of the 1 master blank was covered with zinc phosphate, then it was oiled and so the lb external surface and the lc internal surface was provided with a slipping increasing coating. The 1 master blank prepared as described above was clamped in the 2a mould cavity of the 2 tool fixed on the bench of the 250 ton eccentric press as shown in drawing No. 1, and the clamped 1 master blank was treated with cold extrusion with the help of the 3 expansion mandrel clamped in the moving tool- head of the eccentric press. As a result of the cold extrusion the 1 master blank expanded near the la end, as shown in the diagram, and the le rolling unit receiving surface was formed with surface quality and dimensions suitable for receiving the ball bearings. After the first cold extrusion operation the 1 master blank was turned over in the 2a mould cavity of the 2 tool and the cold extrusion operation described above was performed again in the environment of the other la end of the 1 master blank.

The 1 master blank prepared in this way, expanded at both ends was removed from the eccentric press and the parts of the lb external surface near the la ends were treated by machining themselves so that after the treatment machined connection zones were created with a surface suitable for receiving and fixing spoke crowns. However, after the cold extrusion the lc internal surface of the 1 master blank was left without any further treatment.

Example No. 2

The procedure described above was carried out with the difference that the expansion of both la ends of the 1 master blank was performed in one single step, with the help of extrusion mandrels, brought together, moving opposite each other, so that a 2b forming pocket was situated at the parts of the 2 tool's 2a mould cavity near both la ends of the 1 master blank.

The procedure according to the invention can be applied well for the quick, effective and cost efficient production of the hub sleeve of two-wheeled vehicles, especially bicycles. LIST OF REFERENCES

master blank la end lb external surface lc internal surface Id central part le rolling unit If centre-line lg internal space tool 2a mould cavity

2b forming pocket expansion mandrel 3 a forming surface

Claims

CLAΓMS

1. Procedure for the production of the hub sleeve of two-wheeled vehicles, especially bicycles, in the course of which a master blank is produced from a cylindrical base material, e.g.: pipe material, by cutting, and then machined connection zones are created on the ends of the master blank by machining, characterised by that after the cutting at least a part of the external surface (lb) and/or internal surface (lc) of the master blank (1) is covered with a slipping increasing material, then the master blank (1) is clamped in a mould cavity (2a) having one or more forming pockets (2b), and by expanding the two ends (la) of the master blank (1) with the help of an expansion mandrel (3) by cold extrusion in one or two stages a concave bent rolling unit receiving surface (le) is created, the master blank (1) provided with a rolling unit receiving surface (le) is taken out of the tool (2), and the machining is performed only after this, and the machined connection zones are made independently from the further treatment of the rolling unit receiving surface (le).

2. Procedure as in claim 1, characterised by that the rolling unit receiving surface (le) is made by cold extrusion in one single step.

3. Procedure as in claims 1 or 2, characterised by that the rolling unit receiving surfaces (le) are made in one step at both ends (la) of the master blank (1).

4. Procedure as in claim 3, characterised by that extrusion mandrels, brought together, moving opposite each other are used as expansion mandrels.

5. Procedure as in claims 1 to 4, characterised by that a minimum 250 ton eccentric press is used for the cold extrusion.

6. Procedure as in claims 1 to 5, characterised by that zinc phosphate and oil are used as slipping increasing materials.