The present invention relates to a quick coupling component including one or more valve members for opening and closing a main flow, and a pressure reduction member arranged of a pressure reduction channel in at least one valve member. The pressure reduction member includes a first shut-off element arranged in the pressure reduction channel and is provided with a spherical surface. The shut-off element, in a closed position for the pressure reduction channel the shut-off element, bears against a seat. In an open position for the channel, is lifted from the seat by an activation member counter to the action of a spring function.
A pressure reduction function in quick coupling is already known, and in this respect reference can be made to the U.S. Pat. No. 4,564,042 and 5,159,955. In such a coupling the pressure reduction function can be included in one or both of the coupling components. The pressure reduction function includes a shut-off element in the form of a ball that is acted upon, counter to the action of a spring, in order to lift it from its seat. Media can then flow past the shut-off element. The passing flow causes the pressure, acting counter to the coupling force of the coupling components, to be released. In this way coupling of the coupling components is considerably facilitated. Depending on how the pressure conditions appear before coupling, in the coupling arrangement in question the coupling component concerned or both coupling components is/are provided with a pressure reduction function.
There are great problems involved in achieving an appropriate pressure elimination function. The shut-off element must be completely sealed against the seat surface in question. Otherwise, media can leak past in the closure position of the pressure elimination function media can also leak out, for example, to the outer surface of the coupling component concerned. This surface is thus soiled with media, for example hydraulic oil. Such a soiling cannot normally be accepted, accordingly it is currently demanded of quick couplings that they should be able to function in or create a leakproof environment. In this connection, it should be mentioned that even the leaking of what are, relatively speaking very small quantities of media presents problems. The aim of the invention, among other things is to solve, these problems.
The said above described problems are aggravated by the fact that the quick coupling should be able to be coupled against even relatively high pressures, for example pressures of 300 bar or more, which sets even higher demands on the sealing function in the pressure reduction function. The invention solves this problem too.
Quick couplings are generally manufactured in relatively long series. In addition, different components can be manufactured by different manufacturers. Also an assembly can be carried out by yet another manufacturer, etc. Furthermore, the different components manufactured in this way must, on the one hand, exhibit great accuracy of manufacture and, on the other hand be able to function together in the finally assembled state of the couplings. This necessitates the independence of pressure elimination function in relation to the manufacturing circumstances. The invention solves this problem too.
It must be possible for the quick coupling to function for relatively long periods of time without the need for frequent servicing and replacement of vital components in the coupling. Also it should be possible for a quick coupling to be subjected to a very large number, for example 100,000, of couplings and decouplings. This also places demands on the pressure elimination function, which should come into operation in all coupling instances. The present invention solves this problem too.
The quick coupling should be able to operate at different pressures and pressure conditions with increasing pressures. In addition, it should be possible for a quick coupling to be used in any chosen situation within a wide appropriate coupling range. The pressure reduction function means must be able to function for all the connection possibilities which are conceivable for the coupling in question. The invention solves this problem.
Quick coupling is often part of a product range which is subject to pricing pressures, with the result that it must be possible to use efficient, automated and/or cost-effective manufacturing methods. This invention solves this problem too.
The feature which can principally be regarded as characterizing a quick coupling component according to the invention is that the seat is designed with a seat surface that corresponds to parts of the spherical surface of the shut-off element. The seat surface has a degree of fineness that to a great extent corresponds to the degree of fineness of a shut-off element. To a great extent here means that the degree of fineness of the seat surface should amount to 50-100%, preferably 75% or more, of the degree of fineness of a shut-off element that is used in this connection and has a hardness that substantially exceeds the hardness of the seat material, for example exceeds the hardness of the seat material by 1-4 times. A further characteristic of the invention is that an elasticity inherent to the material of the seat and/or the element contributes to the sealing function of the spherical element against the seat in the said closed position.
No comments:
Post a Comment