DE102015204228A1 - Hydraulic line with damping element - Google Patents

Abstract

The invention relates to a hydraulic line with damping element hydraulic line with damping element, wherein the damping element according to the invention comprises a housing and that in the housing at least one inner part is arranged or formed, which is at least partially elastic.

Description

The invention relates to a hydraulic line with damping element, in particular for a hydraulic release line to a vehicle clutch.

For hydraulic lines, in particular disengagement lines on vehicle clutches, it is necessary to take measures to reduce audible noise and / or perceptible vibrations on motor vehicles and machinery. For the purpose of damping, volume fractions of the flowing liquid are taken up by a damper and released again in a defined manner.

A common solution is to make the hydraulic line completely or partially thin-walled, to allow volume absorption by deformation thereof. The deformation takes place under contact with the environment. In this case, the hydraulic line itself acts damping.

Also known are solutions that work with thin membranes. Due to the flexibility of a thin membrane, a volume absorption is achieved; by a spring action of the membrane, the volume is returned again. In this case, flowing medium is taken transversely to the main stream and a damping box o. Ä. Accessed.

From the German patent application DE 10 2008 060 584 A1 a hydraulic system for motor vehicles with a hydraulic pressure line and with a damping device is known, wherein the damping device comprises a damping volume, which is connected in the manner of a Helmholtz resonator via a connecting channel to the hydraulic line.

Generic solutions also provide for reducing noise-generating resonances by modulating the resulting oscillations in their frequency in order to transform them into frequencies other than the natural frequency of the hydraulic line.

The previously known solutions have in common that they work with thin-walled parts. Thus, they are prone to wear, which significantly shortens their life in the final product.

The object of the invention is to develop a hydraulic line with damping element, which has a long service life.

This object is achieved with the characterizing features of the first claim. Advantageous embodiments emerge from the subclaims.

According to the invention, the hydraulic line has a damping element with a housing in which, according to the invention, at least one inner part is arranged or formed, which is elastic at least in regions.

By using an elastic inner part in a particularly robust housing ensures that volume fluctuations of the hydraulic medium can be compensated, while a long life through the stable housing, which can now have a greater wall thickness, is guaranteed.

The inner part of the damping element consists preferably of at least one elastically deformable foam body or an elastomeric body, wherein the foam body or the elastomeric body is preferably supported against the housing.

Alternatively, an elastically deformable membrane may also be arranged in the housing, which may for example be axially biased and is arranged at a distance from the inner wall of the housing. With an increasing volume of the foam body or the elastomeric body is pressed against the inner wall of the housing, so that the larger volume can be easily absorbed.

Alternatively, in the housing, a membrane may be arranged through which flows the hydraulic medium, and which is spaced at "normal pressure" of the housing wall. If the volume increases, the membrane can expand on the circumference until it rests on the inner wall of the housing.

Any combination of a foam body / elastomer body and a membrane is also possible.

Furthermore, the foam body or the elastomeric body can be inserted into the housing as a separate element or be injected directly to the inner wall of the housing.

The foam body advantageously has trapped air bubbles, which cause its elastic property. In this case, the elastic property of the damping element by material selection and structure structure of the foam body on the nature and the state variables of the liquid in the hydraulic line can be tuned in an advantageous manner, wherein the housing is stiff in relation to the inner part.

The inner part has a volume which fills the housing such that the resulting Cross-section in the damping element substantially corresponds to the liquid-conducting cross-section of the hydraulic line, wherein the inner cross-sectional area of the damping element is greater than the liquid-conducting cross-sectional area of the hydraulic line.

The hydraulic line is formed in particular of sections, which are connected to at least one damping element. It is possible that the hydraulic line has one or more damping elements, wherein a plurality of damping elements can be arranged in series and / or in parallel.

The hydraulic line according to the invention is preferably used in a hydraulic system of a vehicle and connects a pressure-generating component (for example in the form of a master cylinder) with an actuator (for example in the form of a slave cylinder).

The hydraulic line with damping element thus preferably finds application in hydraulically operated release systems of a vehicle (for example for actuating a vehicle clutch).

The hydraulic line is arranged in sections, between which there is at least one stable housing. This is firmly connected to the sections of the hydraulic line and has that opposite a larger internal cross-sectional area. In the space created by the cross-sectional difference, at least one inner part is arranged, which has an elastic property.

To compensate for pressure and / or volume fluctuations in the hydraulic line of the foam body acts elastically on the system, which is supported on the stable housing.

A solid design of the inner part as a foam body allows compared to a thin-walled membrane or pipe version in conjunction with a solid design of the housing a robust design of the damping element with a long service life.

To form a volume uptake to improve the NVH behavior (noise / vibration / harshness) or to damp vibrations occurring within a hydraulic line between a slave and a master cylinder, a closed volume is provided, which is a foam includes.

The housing of the volume absorption according to the invention is formed in contrast to the known in the prior art solutions of a stable material with thicker wall thicknesses and consists of metal, plastic or a combination of materials of metal and plastic.

The air bubbles in the foam ensure the required softness for the volume intake, the rigidity of the housing is achieved by the composition of the plastic material.

The combination of the bubble size and the volume of the foam lead to the desired volume absorption in the hydraulic line.

The invention will be explained in more detail below with reference to an exemplary embodiment and associated drawing.

1 shows a section through a hydraulic line with damping element in use as a release line of a vehicle clutch.

A hydraulic line 1 consists of a first section 1.1 and a big part 1.2 , The two parts 1.1 and 1.2 are with a damping element arranged between them 2 firmly connected.

The damping element 2 consists of a housing 3 , whose inner cross-sectional area is significantly larger than the liquid-conducting cross section of the hydraulic line 1 , This cross-sectional widening is made by an inner part 4 filled in, which is inside the housing 3 is arranged. The housing 3 is via a first connection 3.1 with the first part 1.1 and a second connection 3.2 with the second part 1.2 the hydraulic line 3 connected.

The inner part 4 is advantageously designed as a foam body, the air bubbles 5 contains, which give the foam body an elastic property. Depending on the hardness of the selected material and the volume fraction of air bubbles, the elastic property in the sense of a spring constant is tunable.

The housing 3 is in relation to the inner part 4 Stable and thus contributes not or only insignificantly to the damping. The housing 3 serves as mechanical protection and for supporting the inner part 4 ,

It is advantageous, the liquid-conducting cross section of the hydraulic line 1 in the same dimension through the damping element 2 feed through. Depending on the required size of the inner part 4 can change the dimensions of the case 3 be selected appropriately.

If it proves necessary, several damping elements 2 to use in the same or different vote, the hydraulic line 1 in more than two parts 1.1 and 1.2 split, so that several damping elements 2 can be used in series, in parallel or in combination of both arrangements (not shown).

Kicking in the hydraulic line 1 , which connects a pressure-generating component with an actuator, pressure peaks, the inner part can 4 in the form of the foam body due to the air bubbles contained 5 deform. The deformation of the foam body leads to a volume absorption of the damping element 2 , which in turn leads to the reduction of pressure peaks.

Relaxes the pressure in the hydraulic line 1 , also relaxes the inner part 4 of the damping element 2 , The recorded volume is in the hydraulic line 1 fed back.

Due to the damping of the pressure peaks noise and / or vibration development is counteracted.

The housing 3 does not itself form a volume and can therefore be made of conventional material, such as glass fiber reinforced polyamide. The wall thickness can be chosen so that the desired life is achieved. In the case 3 a foam is introduced, which causes the volume absorption. The bubbles trapped in the foam body 5 form its softness such that the property of compressing increases with increasing pressure.

The polymer of the foam body prevents the trapped air bubbles 5 already fully compressed at a very low pressure.

The composition of the foam body, its structure, the proportion of elastomer / plastic in relation to the air bubbles 5 as well as their size and the volume of the foam body lead to the desired volume absorption. Almost any volume intake can be formed.

LIST OF REFERENCE NUMBERS

1

 hydraulic line

1.1

 first section (the hydraulic line)

1.2

 second section (the hydraulic line)

2

 damping element

3

 casing

3.1

 first connection

3.1

 second connection

4

 inner part

5

 bubbles

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008060584 A1 [0005]

Claims (10)

Hydraulic line with damping element ( 2 ), wherein the damping element ( 2 ) a housing ( 3 ) and wherein in the housing ( 3 ) at least one inner part ( 4 ) is arranged or formed, which is at least partially elastic. Hydraulic line according to claim 1, characterized in that the inner part ( 4 ) of the damping element ( 2 ) consists of at least one elastically deformable foam body, an elastomeric body, an elastically deformable membrane or any combination of the aforementioned body and the membrane. Hydraulic line according to claim 1 or 2, characterized in that the foam body trapped air bubbles ( 5 ), which cause its elastic property. Hydraulic line according to one of claims 1 to 3, characterized in that the elastic property of the damping element ( 2 ) by material selection and structure structure of the foam body on the nature and the state variables of the liquid in the hydraulic line ( 1 ) is tunable. Hydraulic line according to one of claims 1 to 4, characterized in that the housing ( 3 ) in relation to the inner part ( 4 ) is stiff. Hydraulic line according to one of claims 1 to 5, characterized in that the inner part ( 4 ) has a volume which fills the housing in such a way that the resulting cross-section in the damping element corresponds to the fluid-carrying cross-section of the hydraulic line ( 1 ) corresponds. Hydraulic line according to one of claims 1 to 6, characterized in that the internal cross-sectional area of the damping element ( 2 ) is greater than the liquid-conducting cross-sectional area of the hydraulic line ( 1 ). Hydraulic line according to one of claims 1 to 7, characterized in that the hydraulic line ( 1 ) of sections ( 1.1 . 1.2 ), which with at least one damping element ( 2 ) are connected. Hydraulic line according to one of claims 1 to 8, characterized in that the hydraulic line ( 1 ) has one or more damping elements, wherein a plurality of damping elements ( 2 ) are arranged in series and / or in parallel. Hydraulic line according to one of claims 1 to 9, characterized in that the hydraulic line is used in a hydraulic system of a vehicle application and connects a pressure-generating component in the form of a master cylinder and an actuator in the form of a slave cylinder.

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