Pulsation Damper

Abstract

The invention relates to a pulsation damper for damping vibrations of a pressure medium in a hydraulic system, for which purpose the pulsation damper has a membrane (1) in a bore (13) of a housing (15), which is exposed on one side to the pressure medium and on its other side faces a gas-filled chamber (12) in the housing (15), the bore (13) being closed by a plug (2). The membrane (1), together with the plug (2) and a hollow cylindrical support body (3), form an independently operable, functionally pretestable assembly, for which purpose the membrane (1) is substantially pot-shaped and the support body (3) extends into it.

Description

Technical Field

[0001] The invention relates to a pulsation damper for damping vibrations of a pressure medium in a hydraulic system, in particular in a slip-controlled motor vehicle brake system. Background Art

[0002] A pulsation damper for damping pressure medium vibrations in a hydraulic brake system is known from EP 0907533 B1, for which purpose the pulsation damper has a membrane in a hole in a housing, which is exposed on one side to the pressure medium and on the other side faces a gas-filled chamber in the housing, the hole being closed by a plug.

[0003] However, a disadvantage of the pulsation damper is that the membrane first has to be fixed between the plug and the hole in the housing and therefore a preliminary test of the function of the pulsation damper is not possible. The limited pressure vibration damping effect and the durability of the membrane bring about further disadvantages of this structure. Summary of the invention

[0004] It is therefore an object of the present invention to provide a pulsation damper whose function can be easily checked and which features a compact, functionally reliable design while having a high degree of damping.

[0005] According to the invention, this object is achieved by a pulsation damper of the type mentioned at the outset, which has a membrane in a hole in the housing, which membrane is exposed on one side to the pressure medium and on its other side faces a gas-filled chamber in the housing, the hole being closed by a plug, the membrane together with the plug and the hollow cylindrical supporting body forming an independently operable, functionally pretestable component, for this purpose, the membrane being substantially pot-shaped and being provided with grooves on the circumference and with a plurality of ribs extending in the longitudinal direction.

[0006] An exemplary embodiment of the invention is shown in longitudinal section with reference to several drawings and will be described in more detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In the attached picture:

[0008] Figure 1 shows a schematic cross-sectional view of a pulsation damper provided with a rubber membrane having a plurality of transverse grooves on the outer periphery,

[0009] Figure 2 shows a cross-sectional view of a further improvement of a pulsation damper, the rubber membrane of which is provided with longitudinal grooves on the outer periphery,

[0010] Figure 3 shows a cross-sectional view of a further development of a pulsation damper having a metal membrane,

[0011] Figure 4 shows a cross-sectional view of a pulsation damper, the membrane of which is fixed to a supporting body, which is integrally connected to a plug of a closed housing,

[0012] Figure 5 A sectional view of a pulsation damper is shown, the membrane of which surrounds the plug in the region of its tubular section. DETAILED DESCRIPTION

[0013] Figures 1 to 5 Advantageous embodiments of various pulsation dampers for damping pressure medium vibrations in hydraulic systems, in particular in slip-controlled motor vehicle brake systems, are shown in longitudinal section.

[0014] The pulsation damper inserted in each case into a bore 13 of a block-shaped housing 15 has a membrane 1 whose inner side is exposed to a pressure medium which is usually delivered in a pulsating manner by a pressure generator and whose outer circumference is exposed in sections to a gas-filled chamber 12 .

[0015] In all embodiments, the hole 13 provided for receiving the pulsation damper is closed by the plug 2, wherein according to the invention the membrane 1 together with the plug 2 and the hollow cylindrical support body 3 form a compact, independently operable, functionally pretestable assembly, for which purpose the membrane 1 is substantially pot-shaped and the support body 3 extends into it.

[0016] The membrane 1 is made of a permanently elastic material, in particular rubber or metal, whereas the plug 2 is made of cold extruded or machined free-cutting steel. Furthermore, the membrane 1 is provided with a plurality of grooves 18 and / or longitudinally extending ribs 19 along the outer periphery.

[0017] In order to achieve particularly effective vibration damping, Figures 1 to 3 In each of the figures, the support body 3 is traversed by a passage 4, into which a non-return valve 6 is inserted, which is actuated by a compression spring 5 and opens on the outlet side. Figures 1 to 3 It can be seen that a fixed opening 7 is arranged in parallel with the non-return valve 6 in the channel 4 , the fixed opening preferably being configured as a recess in the region of a valve seat 8 provided for the non-return valve 6 in the channel 4 .

[0018] In accordance with Figures 1 to 3 In the embodiment of the invention, the channel 4 has a radial inlet region 9 and an axial outlet region 10 in the support body 3, wherein a fixed orifice 7 and a non-return valve 6 opening in the direction of the outlet region 10 are arranged in the outlet region 10 of the channel 4 for effectively damping vibrations.

[0019] according to Figures 1 to 3 , the plug 2 has a sleeve-shaped section 11, in which the pot-shaped membrane 1 is completely accommodated so that a gas-filled chamber 12 is easily formed between the outer surface of the membrane 1 and the inner surface of the sleeve-shaped plug 2. Since the end of the membrane 1 facing away from the plug 2 is firmly fixed to the sleeve-shaped section 11 by means of the support body 3, the gas-filled chamber 12 is isolated and separated from the pressure medium in the hole 13.

[0020] In all the figures, the support body 3 has a collar 14 which is connected to the sleeve-shaped section 11 in a force-fitting manner in order to securely fix and seal the gas-filled chamber 12 .

[0021] According to Figures 1 to 3 The embodiments are different. Figure 4 In the embodiment, the non-return valve 6 together with the fixing orifice 7 are not integrated in the supporting body 3, because the supporting body 3 is formed integrally directly on the plug 2, and therefore, due to the compact design, the membrane 1 is fixed directly to the collar 14 of the supporting body 3 and is therefore inserted directly into the hole 13 of the block housing 15 together with the plug 2 as a preassembled component.

[0022] An element for adjusting the volume and thus damping pulsations is thus formed by the elastic membrane 1 , which separates the gas filling the chamber 12 from the actuating medium (for example brake fluid) in the bore 13 .

[0023] according to Figures 1 to 3 , the membrane 1 extends completely into the sleeve-shaped section 11 of the plug 2, which is preferably fixed in the block-shaped housing 15 by a so-called snap connection. Figure 4 , it is also possible to introduce the desired contour for accommodating the membrane 1 directly into the bore 13 of the housing 15 instead of using a sleeve-shaped section 11. This creates a damping chamber. In principle, the volume / pressure characteristics of the pulsation damper can be influenced by the contour of the damping chamber, the contour of the sleeve-shaped section 11, the contour of the housing 15 and / or the contour of the membrane 1 in order to reduce the pressure pulsations.

[0024] In accordance with Figures 1 to 4 In all exemplary embodiments, the support body 3 extends into the membrane 1, according to Figures 1 to 3 The support body 3 provides radial sealing pressure of the membrane 1 relative to the inner wall of the sleeve-shaped section 11, and according to Figure 4 The difference thereto is that the membrane 1 is pressed directly against the wall of the hole 13 by the supporting body 3 .

[0025] The spring-loaded check valve 6 is integrated in the support body 3 and releases a large cross section to allow outflow from the defined pressure of the damping pressure medium. Before reaching the defined pressure, the pressure medium flows past the closed check valve 6 through the fixed orifice 7 structurally molded in the valve seat 8 of the support body 3 (or molded in the plunger-shaped check valve 6). The pressure pulse that is not strong enough to open the check valve 6 is absorbed by the elasticity of the membrane 1 and released again when the pressure drops. The pressure fluctuations generated by the pressure generator / pump are therefore shared and partially transferred to the damping chamber. The volume flow to the consumer (Verbraucher) becomes more uniform and the components are less excited to vibrate. The support body 3 together with the channel 4 guides and separates the volume flow here so that it cannot flow out without passing through the fixed orifice 7.

[0026] The membrane 1 is sealed in the radial direction with respect to the hole 13 and with respect to the support body 3. If desired or required, the support body 3 is provided with a collar 14, in particular a deep-drawn collar 14 (see Figure 2 ) and seals the sleeve-shaped section 11 on the outer circumference with respect to the pressure medium (operating medium), so that the pressure medium does not come into contact with the sleeve material and thus avoids possible chemical reactions when the pressure medium (for example brake fluid) comes into contact with zinc-containing surfaces.

[0027] The integration of the fastening opening 7 and the non-return valve 6 in the support body 3 reduces the outlay for arranging passage openings in the housing 15 and the closing caps or balls required therefor.

[0028] The peg-shaped design of the support body 3 enables an optimal incident flow onto the membrane 1 as well as a flow deflection and an optimal outflow of the pressure medium. The support body 3 ensures that the gas volume is securely sealed against the operating medium and that the membrane 1 is securely mounted and prevents the membrane 1 from turning over when the system is filled with vacuum.

[0029] Since all relevant functional surfaces are located inside the sleeve-shaped section 11 or the housing 15, damage to these surfaces is largely excluded. This improves the quality of the surface (bulk material) during production, surface treatment and installation, since the inner surface cannot be damaged. The support body 3 makes it possible to simply integrate the fixing orifice 7 and the non-return valve 6 and check the function of this pre-assembled assembly outside the housing 15.

[0030] at last, Figure 5A further advantageous embodiment of a pulsation damper is shown, the membrane 1 of which has a sleeve-shaped extension 20 which completely surrounds the tubular section 11 of the plug 2 along its outer circumference, wherein the end of the extension 20 between the section 11 and the housing 15 is advantageously fixed under radial prestress. As a result, the plug 2 is completely covered by the membrane 1 within the bore 13, so that chemical reactions of the plug material are prevented due to the separation from the brake fluid. Furthermore, between the section 11 and the pot-shaped region of the membrane 1, a plurality of ribs 19 extending in the longitudinal direction are provided on the circumference of the membrane 1, and the design of the ribs can therefore be used to adjust the stiffness of the membrane 1.

[0031] Figure 5 The other details of the non-return valve 6 shown correspond substantially to Figures 1 to 3 Those described, however, have the special feature that the support body 3 with the non-return valve 6 is arranged separately in the housing 15 .

[0032] Reference numerals list

[0033] 1. Membrane

[0034] 2 Plug

[0035] 3 Support body

[0036] 4 channels

[0037] 5 Compression spring

[0038] 6 Check valve

[0039] 7 Fixed orifice

[0040] 8 Valve seat

[0041] 9 Entrance Area

[0042] 10. Exit Area

[0043] 11 Segment

[0044] 12 Chamber

[0045] 13 holes

[0046] 14 Ring

[0047] 15 Housing

[0048] 16 Springform jar

[0049] 17 Seals

[0050] 18 Grooves

[0051] 19 rib

[0052] 20 Extension

Claims

1. A pulsation damper for damping vibrations of a pressure medium in a hydraulic system, the pulsation damper having a membrane in a hole in a housing, the membrane being exposed on one side to the pressure medium and on the other side facing a gas-filled chamber in the housing, the hole being closed by a plug, characterized in that The membrane (1) together with the plug (2) forms an independently operable, functionally pretestable assembly, wherein the membrane (1) is substantially pot-shaped and is provided with grooves on the periphery and a plurality of ribs (19) extending in the longitudinal direction.

2. The pulsation damper according to claim 1, characterized in that A hollow cylindrical support body (3) is provided, which is penetrated by a passage (4), into which a non-return valve (6) is inserted, which is actuated by a compression spring (5) and opens on the outlet side.

3. The pulsation damper according to claim 2, characterized in that A fixed orifice (7) is arranged in the channel (4) parallel to the non-return valve (6).

4. The pulsation damper according to claim 3, characterized in that The fixed orifice (7) is configured as a recess in the region of a valve seat (8) provided for a non-return valve (6) in the channel (4).

5. The pulsation damper according to claim 3, characterized in that The channel (4) has a radial inlet region (9) and an axial outlet region (10) in the support body (3), wherein a fixed orifice (7) and a non-return valve (6) opening in the direction of the outlet region (10) are arranged in the outlet region (10) of the channel (4).

6. The pulsation damper according to claim 1, characterized in that The plug (2) has a sleeve-shaped section, into which the membrane (1) is inserted.

7. The pulsation damper according to claim 1, characterized in that A gas-filled chamber (12) is formed between the membrane (1) and the plug (2) and is separated from the hole (13) for transmitting the pressure medium by the supporting body (3).

8. The pulsation damper according to claim 6, characterized in that The supporting body (3) has a collar (14) which is connected to the sleeve-shaped section in a force-fitting manner in order to seal the gas-filled chamber (12).

9. Pulsation damper according to one of the preceding claims, characterized in that The membrane (1) is made of a permanently elastic material.

10. The pulsation damper according to claim 1, wherein: The plug (2) is made of free-cutting steel by cold extrusion or machining.

11. The pulsation damper according to claim 1, characterized in that The membrane (1) has a sleeve-shaped extension (20) which completely surrounds the tubular section of the plug (2) along its outer circumference and wherein the end of the extension (20) is fixed between the section and the housing (15) under radial prestress.

12. The pulsation damper according to claim 11, characterized in that Between the section and the pot-shaped region of the membrane (1), a plurality of ribs (19) extending in the longitudinal direction are arranged on the circumference of the membrane (1).

13. The pulsation damper according to claim 1, wherein: The hydraulic system is a slip-controlled motor vehicle braking system.

14. The pulsation damper according to claim 9, wherein: The membrane (1) is made of rubber or metal.

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