Pulse damper with clamping sleeve and method for manufacturing pulse damper with clamping sleeve

Abstract

The invention relates to a pulse damper (1) for damping pressure medium fluctuations in a hydraulic system, in particular a brake system of a motor vehicle, comprising a plug (2) having a sleeve-like extension (3) and a cap-like elastic diaphragm (4) which is at least partially inserted into the extension (3) of the plug (2), the diaphragm (4) comprises a collar (17) having an edge-side flange (5), the collar (17) of the diaphragm (4) being turned over around an edge (10) of the extension (3), whereby the flange (5) rests on the outside of the extension (3), characterized in that the diaphragm (4) is connected to the stopper (2) in a pressure-tight manner by means of a clamping sleeve (7) which engages the flange (5) and the extension (3) on the outside; the invention also relates to a method for producing a pulse damper (1).

Description

Technical Field

[0001] The invention relates to a pulsation damper according to the preamble of the independent device claim and to a method for producing a pulsation damper according to the preamble of the parallel method claim. Background Art

[0002] Document DE 10 2021 202 290 A1, which belongs to the prior art, discloses a pulse damper for damping pressure medium fluctuations in hydraulic systems, particularly motor vehicle brake systems. The pulse damper is arranged in a hole in a housing. The pulse damper comprises a diaphragm inserted into a plug, wherein the plug is inserted into the hole with the diaphragm first. The diaphragm is rolled around an extension of the plug, with the ends of the diaphragm being fastened to the outside of the plug extension by a retaining ring. To this end, the diaphragm is vulcanized onto the retaining ring. By fastening the diaphragm to the plug using the retaining ring, an air-tight and liquid-tight unit is formed. This is because the diaphragm inserted into the plug extension and the plug define a gas space that performs the damping function. As is known, the diaphragm is exposed to pressure fluctuations of the hydraulic fluid on the side opposite the gas space. A piston pump generates pulsed pressure peaks, which the pulse damper damps on the path of the hydraulic fluid to the consumer. When a pressure peak occurs, the pressure is reduced by the elastic diaphragm pressed into the gas space. The fluid flow thus flows to the hydraulic consumer with reduced pressure fluctuations.

[0003] The tightness of the pulsation dampener or gas space is crucial for ensuring the functionality of the hydraulic system. Due to component tolerances and differential material expansion during temperature fluctuations, leakage can occur between the diaphragm and the plug. However, during operation, gas must not escape from the gas space and enter the hydraulic system. Gas entrainment in the hydraulic fluid could cause failures in critical system components. For this reason, it is advisable to ensure a permanently pressure-tight connection between the elastomeric diaphragm of the pulsation dampener and the plug. Summary of the Invention

[0004] The object of the present invention is to provide a pulsation damper for damping pressure medium fluctuations, in which the pressure-tight connection between the plug and the diaphragm is improved; and to provide a method for producing a pulsation damper, which ensures an improved pressure-tight connection between the plug and the diaphragm.

[0005] The object on which the invention is based is achieved with a pulsation damper according to the features of the independent device claim and with a method for producing a pulsation damper according to the features of the independent method claim.

[0006] Pulsation dampers are used in hydraulic anti-skid controlled motor vehicle brake systems to damp pressure medium fluctuations caused by piston pumps. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Preferred embodiments of the invention are apparent from the dependent claims and from the following description of exemplary embodiments with reference to the drawings.

[0008] In the attached figure:

[0009] Figure 1 shows the pulse dampener in the housing, and

[0010] Figures 2a to 2e The method steps for producing a pulsation damper are shown. DETAILED DESCRIPTION

[0011] Figure 1 An exemplary pulsation damper 1 is shown, which is inserted into a bore 18 of a housing 9. The housing 9 can be, for example, the housing of a piston pump. The bore 18 is exposed to a hydraulic fluid, for example from a piston pump. The hydraulic fluid provided by the piston pump is under fluctuating pressure. The pulsation damper 1 therefore serves to reduce high pressure peaks. The pulsation damper 1 essentially comprises a plug 2 and a diaphragm 4 made of an elastic material. The plug 2 comprises a sleeve-shaped extension 3 extending from its bottom. The diaphragm 4 is at least partially inserted into this extension 3. The collar 17 of the diaphragm 4 is rolled over the edge 10 of the extension 3, wherein the edge side of the collar 17 forms a flange 5 which rests on the outside against the extension 3 of the plug 2.

[0012] The diaphragm 4, which is inserted into the extension 3, delimits, together with the plug 2, a gas space 6 with a damping effect. The diaphragm 4 is therefore exposed to the gas on the side facing the plug 2 and to the hydraulic fluid on the side facing away from the plug 2. In order to ensure a pressure-tight connection between the plug 2 and the diaphragm 4, a clamping sleeve 7 is provided, according to the example. The clamping sleeve 7 presses the flange 5 against the extension 3 from the outside and is itself pressed into the extension. To this end, the clamping sleeve 7 is made of a metallic material, preferably steel. The clamping sleeve 7 thus clamps the elastomeric flange 5 against the extension 3, thereby forming a permanent pressure-tight connection between the diaphragm 4 and the plug 2. Consequently, no gas can escape from the gas space 6 into the bore 18 or into the hydraulic fluid. The contour of the clamping sleeve 7 is selected so that radial and axial clamping forces act on the flange 5.

[0013] according to Figures 2a to 2e , is intended to illustrate an exemplary method for producing such a pulse damper 1. Figure 2aIn the first method step, a diaphragm 4 and a plug 2 are provided. The elastomeric diaphragm 4 has already been vulcanized into its final shape. Here, the cap-shaped diaphragm 4 comprises a hollow cylindrical wall section and a bottom, which is inserted into the extension 3 of the plug 2 with the bottom facing forward. The hollow cylindrical wall section transitions into an outward-turned collar 17, at the edge of which a flange 5 is formed. For this purpose, the collar 17 is arranged to be placed around the edge 10 of the extension 3. For this purpose, the flange 5 is arranged to be pressed onto the extension 3 in a pressure-tight manner on the outside by a clamping sleeve. For this purpose, the extension 3 has a flange groove 11 surrounding the outside below the edge 10, into which the flange 5 is inserted. Below the flange groove 11, the extension 3 has a clamping groove 12, into which a part area of ​​the clamping sleeve is then pressed. Furthermore, the extension 3 or the plug 2 comprises in the base region an outer peripheral rivet groove 13 which is provided for pressing the plug 2 against the housing during a rivet joining process.

[0014] Then, according to Figure 2b In the next method step, the membrane 4 is inserted into the extension 3 of the plug 2 , so that the collar 17 of the membrane is rolled around the edge 10 of the extension 3 and the collar 5 rests in the collar groove 11 .

[0015] In accordance with Figure 2c In the next method step, the clamping sleeve 7 is provided at the pressing tool 19. The diameter of the clamping sleeve 7 is dimensioned so that it can be pushed onto the extension 3 of the plug 2. In other words, the inner diameter of the clamping sleeve 7 essentially corresponds to the outer diameter of the extension 3. This outer diameter is measured below the clamping groove 12. In addition, the clamping sleeve 7 comprises a narrowed edge 14 on the upper side, which is then placed above the flange 5 in order to achieve a pressing force that acts essentially axially on the flange 5 there. Furthermore, the clamping sleeve 7 comprises a widened edge 15 on the lower side, which enables it to be pushed onto the extension 3 of the plug 2 in a centered manner.

[0016] Then, according to Figure 2dIn the next method step, the clamping sleeve 7 is pushed over the flange 5 and onto the extension 3, so that the clamping sleeve 7 rests against the flange 5 with its narrowed edge 14. The pressing tool 10 presses the edge 14 axially against the flange 5. Consequently, the narrowed edge 14 of the clamping sleeve 7 presses the flange 5 into the flange groove provided for it. However, the conical transition area from the narrowed edge 14 to the normal diameter of the clamping sleeve 7 also presses the flange 5 into place. Subsequently, the clamping sleeve 7 is pressed against the extension 3 using the clamping tool 8 acting from the outside. To this end, the clamping tool 8 comprises segments that are displaced radially inward. Specifically, the clamping tool 8 acts on a defined position of the clamping sleeve 7 to press the clamping area of ​​the clamping sleeve 7 into the clamping groove provided for this purpose in the extension 3. The resulting radial diameter reduction causes plastic deformation of the clamping sleeve 7 in the clamping area, resulting in a clamping force acting radially on the extension 3. As a result, the diaphragm 4 or its flange 5 is fastened in a pressure-tight manner to the plug 2 or its extension 3. The connection between the plug 2 and the diaphragm 4 established in this way is considered to be pressure-tight. This pressure-tight connection is not affected by any component tolerances, and different material expansions during temperature changes do not pose a problem.

[0017] Finally, according to Figure 2e In a further method step, the pulsation damper 1 assembled according to the example is inserted into the hole 18 of the housing 9. The plug 2 is deformed by the rivet tool 16 during the rivet connection with the hole 18 and is thus firmly and also pressure-tightly connected to the housing 9.

[0018] Reference Signs List

[0019] 1 Pulsation Damper

[0020] 2 plugs

[0021] 3 Extension

[0022] 4 diaphragms

[0023] 5 flange

[0024] 6 Gas space

[0025] 7 Clamping sleeve

[0026] 8 Clamping tool

[0027] 9 Housing

[0028] 10 Edge

[0029] 11 Flange groove

[0030] 12 Clamping slots

[0031] 13 Rivet groove

[0032] 14 Narrowing Edges

[0033] 15 Widened edge

[0034] 16 Riveting tools

[0035] 17 Ring

[0036] 18 holes

[0037] 19 Extrusion Tool

Claims

1. A pulse damper (1) for damping pressure medium fluctuations in a hydraulic system, in particular in a motor vehicle brake system, comprising: A plug (2) having a sleeve-shaped extension (3) and a cap-shaped elastic membrane (4), the membrane being at least partially inserted into the extension (3) of the plug (2), wherein the membrane (4) comprises a collar (17) with an edge-side flange (5), wherein the collar (17) of the membrane (4) is rolled around the edge (10) of the extension (3), whereby the flange (5) rests on the outside against the extension (3), characterised in that the membrane (4) is connected to the plug (2) in a pressure-tight manner via a clamping sleeve (7) which engages on the outside with the flange (5) and the extension (3).

2. The pulse damper (1) according to claim 1, characterized in that The extension (3) of the plug (2) comprises a flange groove (11) surrounding the outside, and the flange (5) of the diaphragm (4) rests in the flange groove.

3. The pulse damper (1) according to claim 1 or 2, characterized in that The extension (3) of the plug (2) comprises a clamping groove (12) surrounding the outside, into which the clamping region of the clamping sleeve (7) is pressed.

4. The pulse damper (1) according to claim 1, characterized in that The clamping sleeve (7) comprises a narrowed edge (14) which generates an axial clamping force on the flange (5).

5. The pulse damper (1) according to any one of claims 1 to 4, characterized in that The clamping sleeve (7) comprises a widened edge (15), by means of which the clamping sleeve (7) is placed on the extension (3).

6. A method for manufacturing a pulse damper (1), comprising the following steps: - providing a plug (2) having an extension (3); - providing a membrane (4) made of an elastomeric material, said membrane having an inverted flange (5); - inserting the membrane (4) into the extension (3) of the plug (2), wherein the flange (5) rests on the outside against the extension (3), characterized in that - providing a clamping sleeve (7) and pushing said clamping sleeve (7) axially onto said extension (3); and - axially compressing the clamping sleeve (7) using a pressing tool (19) so that a portion of the clamping sleeve (7) is pressed axially towards the flange (5); and - radially compressing the clamping sleeve (7) using a clamping tool (8) so that the clamping region of the clamping sleeve (7) is pressed against the extension (3).

7. The method according to claim 6, characterized in that The flange (5) is pressed into the flange groove (11) of the extension (3) by means of the narrowed edge (14) of the clamping sleeve (7).

8. The method according to claim 6 or 7, characterized in that The clamping region of the clamping sleeve (7) is pressed into the clamping groove (12) of the extension (3).

9. The method according to any one of claims 6 to 8, characterized in that The membrane (4) is vulcanized beforehand into a hat-like shape with an outward-turned collar (17) having an edge-side flange (5).

10. The method according to any one of claims 6 to 9, characterized in that Prior to the aforementioned method steps, the clamping sleeve (7) is produced by deep drawing.

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