DE1240264B - Method of manufacturing a bladder for pressure accumulators - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

B 29 h

German KL: 39 a6- 3/04

Number: 1240264

File number: B 81057 X / 39 a6

Filing date: March 19, 1965

Open date: May 11, 1967

The invention relates to a method for producing a bladder for pressure accumulators for receiving a pressure medium, in particular a compressible one, made of an elastomeric material through a skin enveloped filler body made of porous, elastomeric material, which has a valve body at one end has, in particular for pressure medium tanks or shock absorbers.

A known type of these devices consists of a rigid container, one in the container space a liquid space and a bladder dividing a gas space - the gas space being separated from the bladder itself is formed - and one valve each assigned to the liquid space and the gas space. To When the container is assembled, the bladder often becomes very high with gas via the valve assigned to it Pressure inflated; it then rests against the container wall on all sides and presses the closing member of the the valve assigned to the liquid space on its seat. In operation, a pressure medium, be it for Storage of hydraulic fluid, be it to absorb pressure surges, via this valve into the container pressed, the bladder being increasingly compressed. The skin of the contracting, unstable bladder wrinkles and kinks, what after frequent repetition - like it im Operation is the case - can lead to cracks and thus to the destruction of the bladder.

It is known to fill part of the bladder volume with a spongy filler, ζ. B. made of foam rubber or foam to fill. However, this solution has the disadvantage that the bladder when contracting and up to the point in time at which it is in contact with the packing, also dangerous Can form folds and creases. In addition, it is very cumbersome to put a packing through the narrow bubble opening to introduce, which then - which is also necessary - have a certain shape and rigidity target.

It is also known to completely fill the volume of a bladder with a foam-like filling body, as a result of which the formation of folds and kinks is largely avoided. In one case, the packing is preformed and inserted into the bladder. As already mentioned, this is very difficult in the case of bladders with a narrow insertion opening. In another case, the foam is injected directly into the bladder, in particular at the same time as a pressurized gas, in order to achieve a certain pre-tensioning of the bladder. To do this, however, it is necessary to insert the bladder into the container before the filling body is injected and to seal it off tightly. This is quite a method of making a bladder for
Pressure accumulator

Applicant:

Robert Bosch GMBH.,
Stuttgart W, Breitscheidstr. 4;
Carl Freudenberg,
Weinheim (ad Bergstrasse)

Named as inventor:

Klaus Rose, Mundeisheim;

Georg Heuss, Weinheim (a. D. Bergstrasse)

borrowed awkward, and it is then no longer possible to open the bladder when injecting the To examine any damage caused by the foam. Also, these bubbles are hardly for High-pressure energy storage suitable as there are no actual gas feeds to the interior of the bladder (important for refilling the bladder) are available, and no precautions have been taken thus injected gas fills the bubble volume evenly. Next it is not possible to use the packing to give a special shape deviating from the interior of the bladder or with it a special shape Connect parts.

The invention is therefore based on the object of providing a bladder, in particular also for high-pressure energy containers, to create that is reliable and easy to manufacture.

This is achieved according to the invention in that the filling body for producing the enveloping skin is immersed in a solution of the elastomeric material.

The production is therefore very easy. The preformed packing is dipped in the liquid material creates a skin that forms the skin of the bladder. The packing does not need any more awkward to be introduced into the bladder; it is also firmly attached to their skin.

The base of the valve body is advantageously embedded in the filler body before the immersion.

The method is explained using an exemplary embodiment. The drawing shows a longitudinal section through an accumulator with the bladder.

703 579/187

Claims (2)

The pressure accumulator consists of a rigid, cylindrical container 1 ending in curved bottoms. A relatively wide opening 2, which receives a valve body 3, is located on the lower container bottom. A line (not shown) for pressure oil is connected to this. On the opposite container bottom there is a relatively narrow bore 4 which receives a valve body 5 which has a holder 6 on its part protruding into the container. ίο Hangs inside the container 1, held in a constriction on the valve body 5, a bladder with a skin 7 which - with the exception of a cavity 8 extending in the axial direction of the bladder - is completely filled by a filler body 9. This consists of a porous elastomeric material with open pores, e.g. B. made of foam rubber. The skin 7 is made of elastomeric material, e.g. B. an oil and gasoline resistant synthetic rubber. The bladder is made as follows: In a filler body made of the material mentioned, with the desired shape and size - as the finished bladder should have - the holder 6 of the valve body 5 is buttoned at the exit of the cavity 8 in such a way that the holder is surrounded by the filler material is surrounded. The filler body is then immersed one or more times in a bath made of the liquid bladder material. Depending on the type of material and the frequency of immersion, a more or less thick, elastic skin is then formed on the surface of the filler body, which is firmly bonded to it. The time sequence of the various immersion processes depends on the material to be used. Diving can also be followed by post-treatment of the bladder skin using known methods. The finished bladder can be inserted through the relatively wide opening 2 without difficulty, since it can be easily compressed. After the pressure accumulator has been assembled, the bladder is filled with gas via the valve body 5 to the desired pressure. Thanks to the cavity 8, it also reaches the parts of the filler body which are further away from the inlet. If necessary, lateral branches can also start from the cavity. Since the filler body is porous, the amount of gas injected practically corresponds to that which a bladder would absorb without a filler body. After the bladder is filled with compressed gas, it lies against the inside wall of the container on all sides and closes the valve in valve body 3. When the accumulator is loaded, the bladder is compressed by pressurized oil flowing in through this valve until a state of equilibrium between gas and liquid pressure occurs. The filling body gives the bladder a certain rigidity so that no sharp folds or kinks can form on the bladder skin when it shrinks. The bladder thus offers an optimum of service life and storage power at an affordable cost. Patent claims: 1. A method for producing a bladder for pressure accumulators, for receiving one, in particular compressible pressure medium, made of an enveloped by a skin made of elastomeric material Packing body made of porous, elastomeric material, which has a valve body at one end, in particular for pressure medium tanks or shock absorbers, characterized in that the filling body for producing the enveloping skin in a solution of the elastomeric material is dived. 2. The method according spoke 1, characterized in that the foot of the valve body is embedded in the filler body prior to diving . 1 sheet of drawings 709579/187 5.67 © Bundesdruckerei Berlin