DE1167004B - Fabric press fabric - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: -B-29-d

6> 0 <Tf "

German class: 39 a3 - 3/02

Number:
File number:
Registration date:
Display day:

1167 004
B 54428 X / 39 a3
August 14, 1959
April 2, 1964

The invention relates to pressed fabric materials, such as those particularly for producing highly wear-resistant materials and fatigue strength stressed machine parts, for example camshaft gears of internal combustion engines. Such press fabrics consist of one or more Fabric layers, for example made of cotton fabric, which are impregnated with a binder, the essentially a curable resin and a material which improves the sliding properties of the molding material contains. They can be in the form of semi-finished products, i.e. H. as plates or tubes, or as fittings, For example, rings for the production of gear rings that are still united with other parts could be.

Attempts have already been made to improve the sliding properties by adding graphite, and it turned out but that small additions of graphite do not bring any success worth mentioning, while larger additions bring about the connection of the individual fabric layers adversely affect one another and thus the splitting strength (Gap load according to DIN 7735) of the pressed fabric considerably. It is also known Add carbon black as a coloring agent in small proportions of no more than 1% of the impregnation mass.

According to the invention, it is now proposed that carbon black be used as the slip properties improving substance Proportions of at least 3 to 25%, preferably 15 to 20%, based on the weight of the curable Resin to use.

It was found quite unexpectedly that soot, in larger amounts of the impregnating mass added, important mechanical properties of the fabric pressed fabrics improved very significantly, so that the life of these manufactured, especially heavily on wear and fatigue strength stressed machine parts is increased considerably.

Fabric pressed fabrics according to the invention show a comparison with those of the previously usual type significantly lower coefficient of friction and a considerably increased abrasion resistance, impact strength and fatigue strength. Only in the area of higher soot proportions does the splitting strength decrease a little. In general, however, this can be accepted without further ado with regard to the more substantial mechanical properties and is moreover, if ever necessary, to be compensated by the designer without noticeable additional effort.

The invention therefore allows just those pressed fabric

Applicant:

Robert Bosch GMBH.,
Stuttgart W, Breitscheidstr. 4th

Named as inventor:

Dipl.-Chem. Karl Würth, Stuttgart-Feuerbach

mechanical properties of the fabric pressed fabrics to improve very noticeably, on which it is highly stressed Parts, such as the camshaft gears mentioned at the beginning, are what matter in the first place.

According to the invention, it is advantageous to use the carbon black preferably and at least partially in colloidal To use fineness, namely in the form of so-called active or semi-active carbon black with a Grain size smaller than 40 ηΐμ. The incorporation) of the Soot in the impregnating mass is to be carried out particularly carefully and thoroughly.

In particular, it has been found that the proportion of carbon black does not expediently exceed 25% because larger proportions reduce the splitting strength too much without taking other mechanical values into account to provide considerable advantages. The optimum proportion of soot naturally depends on the properties the type of carbon black used, but it has been shown that the optimum of the carbon black content in general is 15 to 20%.

In the case of pressed fabric materials according to the invention with 17.5% carbon black, compared to pressed fabric materials the following improvements of the mechanical values achieved in the known way:

Friction coefficient decrease by 50%

Resistance to abrasion .. 150% increase
Impact strength increase of 30%

The splitting strength (splitting load) only decreased by 10%, but still remained above the minimum value according to DIN 7735.

Claims (2)

Patent claims: 1. Pressed fabric, especially for the production of strong wear and fatigue strength stressed machine parts, for example 409 557/506 wise camshaft gears of internal combustion engines, consisting of one or more Layers of fabric impregnated with a binder which is essentially a curable resin and contains a material which improves the sliding properties of the molding material, characterized in that that the slip properties improving substance carbon black in proportions of at least 3 to 25 * / o, preferably 15 to 20%, based on the weight of the uncured resin. 2. Pressed fabric according to claim 1, characterized in that the carbon black is at least partially is of colloidal fineness, preferably with a grain size smaller than 40 ΐημ. Considered publications:
German patent specification No. 846 803. 409 557/506 3.64 © Bundesdruckerei Berlin