AU2012200576B2

AU2012200576B2 - Vibration damper with stone chip protector

Info

Publication number: AU2012200576B2
Application number: AU2012200576A
Authority: AU
Inventors: Guenther Handke
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2011-02-03
Filing date: 2012-02-02
Publication date: 2015-01-15
Anticipated expiration: 2032-02-02
Also published as: DE102012200926A1; AU2012200576A1

Abstract

Abstract Vibration damper with stone chip protector A vibration damper with stone chip protector is proposed in which the stone protector comprises a protective section, which at least partially surrounds the damper tube in its circumference and at the same time encloses 10 an air gap that extends radially with respect to the axial extension of the vibration damper, and where the stone chip protector features at least one contacting section that axially delimits the protective section on at least one side, in which the contacting section can be 15 fixed at least indirectly to the vibration damper in its bottom section axially and radially relative to its longitudinal axis. The invention is characterised in that the stone chip protector is made as a single piece from sheet metal, in which the contacting section of the stone 20 chip protector has at least one gusset that is formed in its end section radially inwards and where the gusset has a contact surface that is axially supported by the bottom section of the vibration damper, and where the stone chip protector has at least one mounting section extending 25 from it for the mounting of other components. Fig. 1 23 |23 42222 2*-2 31- 31, -31 21b 3 33

Description

Pool Section 29 Regulation 3.2(2) AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: Vibration damper withy stone chip protector The following statement is a full description of this invention, including the best method of performing it known to us: P111ABAU/0610 Vibration damper with stone chip protector 5 Field of the Invention The invention concerns vibration dampers, and in particular stone chip protectors for such dampers. Vibration dampers of this kind are used in the automobile industry as a suspension strut, for example. 10 Background and Prior Art to the Invention German patent document DE10 2006 001 305 B3 describes a stone chip protector for a vibration damper which is made from plastic in the shape of a tubular component which is 15 arranged in a fixed position at a tubular damper strut. Said tubular component is supported via retaining lugs on a connecting member, the retaining lugs being positively connected to the tubular component via at least one latching connection. 20 One disadvantage of a stone chip protector made of plastic is the inherent ageing process to which plastic is subject to. Research has shown that plastics used in engineering are subject to a self-accelerating thermal 25 ageing process, which is caused by so-called initiator radicals. Said initiator radicals are formed through the mechanical fracture of polymers, which is caused by thermal energy or light energy. Light and oxygen also lead to an accelerated ageing of plastics. Generic 30 vibration dampers convert the introduced mechanical energy into heat. The heat radiated by the vibration dampers accelerates the ageing process of a stone chip protector made of plastic. It becomes brittle, porous and 2 finally fractures. The ageing period is dependent on the chemical composition of the respective plastic used. A latching connection made of two plastic components also 5 has a disadvantage in that the surface strength of plastic is in most instances lower than that of a metal. Since vibration dampers are subjected to vibrations that are caused on the one hand by the combustion engine and on the other hand by the road surface, abrasion occurs on 10 the components that are connected by the latching connection. This wears the material in the contact region of both components, which can lead over time to unpleasant rattling noises. 15 Modern motor vehicles are highly complex systems that comprise a multitude of components and sensors. This results in stringent space requirements. Each component is assigned a fixed position and a fixed location on or inside the vehicle. The brake hoses of the vehicle are in 20 most instances routed along the suspension strut to the brake piston. Since said routing must not be changed for safety reasons, the brake hose support must not be able to rotate, nor must it be allowed to move in axial direction along the strut. 25 In the production of mono-tube dampers, a difficulty arises in that auxiliary elements, such as for example a spring collar or a brake line support bracket, are difficult to attach to the mono-tube damper. Using 30 resistance welding for attaching elements to a damper tube in the reciprocating area of the piston is not recommended. A damper tube is a precision component that does not permit dimensional deviations in the 3 reciprocating area of the piston. The temperature and pressure exerted on the damper tube during resistance welding can change the geometry of the damper tube, which will cause jamming of the piston around the welding area. 5 It is of course possible to attach auxiliary elements to a damper tube through laser welding. However, purchasing a laser welding machine is extremely costly. 10 In light of the above described shortcomings, it is desirable to develop a stone chip protector for a vibration damper in which one or more of the above mentioned problems are ameliorated or avoided all together. 15 Summary of the Invention A first aspect of the present invention provides a stone chip protector for a vibration damper, comprising: a protective section shaped to at least partially 20 circumferentially surround a damper tube of a vibration damper whilst maintaining a radial air gap to the damper tube along at least part of the longitudinal extension of the damper tube; at least one contacting section which axially delimits 25 the protective section on at least one axial end thereof and which can be secured, at least indirectly, to the damper tube so as to fix the stone chip protector against axial and radial movement relative to the vibration damper; and a mounting element by way of which the vibration damper 30 is securable to a vehicle, characterised in that the stone chip protector features at least one strap, the terminal end of which is not radially inwardly flanged, and the stone chip protector and mounting element are secured to one 4 another by one of an integral, permanent connection such as welding, or the stone chip protector and the mounting element are made integral with one another, from sheet metal. 5 A second aspect of the invention provides a vibration damper having a damper tube and a stone chip protector according to the first aspect of the invention, wherein the protective section at least partially surrounds the damper tube and the 10 contacting section which axially delimits the protective section on one axial side is secured to the damper tube directly or indirectly such that the stone chip protector is fixed against axial and radial movement at the vibration damper. 15 Advantageously, a single-piece stone chip protector can be produced simply and cost-effectively by way of sheet metal forming. Moreover, a stone chip protector manufactured in this way is characterised by extremely high robustness, 20 longevity and ruggedness against external influences. Any number of mounting sections may be implemented, independent from the design and the customer requirements, which are formed integrally with the other parts of the stone chip protector. 25 A stone chip protector made from sheet metal may be attached to the bottom or top end section of the damper tube by means of clamping, roll forming or welding. In a preferred embodiment, the stone chip protector is supported through 30 its contact surfaces at the bottom section of the vibration damper. From experience, triple-welding has proven to be a cost-effective and simple 5 method of securing the stone chip protector to the damper tube. Thus the stone chip protector, the vibration damper and a mounting element attached thereto for mounting said damper to another component of the vehicle, are welded 5 together in one process. This produces a connection that cannot twist, which is of utmost importance for components that need to be attached and maintain a defined spatial location, for example a brake line. 10 According to a further advantageous embodiment, the stone chip protector may comprise a positioning section which axially bounds or delimits the protective section on at least one side thereof. The purpose of the positioning section is to fix the axial position of a component 15 surrounding the damper tube, such as a spring collar, for example. Depending on the design of the stone chip protector, the positioning section can be formed by or be a continuation of the contacting section. 20 In accordance with a further preferred embodiment, the protective section can be devised such that it only partially surrounds the damper tube thereby to leave an uncovered peripheral section accessible. This measure enables an even better heat dissipation from the 25 vibration damper into its surroundings. The axial and radial defined position of the mounting section embodied at the stone chip protector can advantageously be achieved by securing the stone chip 30 protector against rotation on the vibration damper. If a permanent connection of at least two of the components vibration damper, stone chip protector and 6 mounting element is required, then it is best to have an integral connection between these components. The mounting section can be fastened to the vibration 5 damper in order to fix the defined position at the vibration damper of other components secured to the mounting section. In embodiments where the mounting section is made from sheet metal and integrally with the stone chip protector, such position can not be changed or 10 adjusted at the stone chip protector. Further preferred and/or advantageous features of the invention will become apparent from the following description of two preferred embodiments of the invention 15 which are illustrated in the attached drawings. BREIF DESCRIPTION OF THE DRAWINGS Fig. la shows an elevation, partially in section, of a vibration damper with stone chip protector according 20 to a first arrangement; Fig. lb shows an elevation, partially in section, of the stone chip protector used in the vibration damper of fig. la; 25 Fig. 2a shows an elevation, partially in section, of a further arrangement of a vibration damper with stone chip protector; 30 Fig. 2b shows an elevation, partially in section, of the stone chip protector used in the vibration damper of fig. 2a; 7 Fig. 3a shows an elevation, partially in section, of an embodiment of a vibration damper with a stone chip protector according to the invention; and 5 Fig. 3b shows an elevation, partially in section, of the stone chip protector used in the vibration damper of fig. 3a. DESCRIPTION OF PREFERRED EMBODIMENTS 10 Fig. la depicts a vibration damper 1 with stone chip protector 2 according to a first embodiment. The stone chip protector 2 comprises a protective section (or portion) 22, which at least partially surrounds the circumference of damper tube 5 of the vibration damper 1. 15 The stone chip protector 2 encloses an air gap 4 that extends radially relative to the axial extension of vibration damper 1. Moreover, the stone chip protector 2 features at least one contacting section (or portion) 21, which provides at least on one end an axial limit of 20 protective section 22. The contacting section 21 of stone chip protector 2 is shown in all drawings at a bottom location. However, such arrangement is not exclusive, as its location is dependent on the respective product design and could equally be present at the head part of 25 stone chip protector 2. It will be seen that in all arrangements and embodiments illustrated in figures la, 2a and 3a, the stone chip protector 2 is secured and fixed, by way of its 30 contacting section 21, against axial and radial movement relative to the longitudinal axis of damper 1 at least indirectly at a bottom section 11 of vibration damper tube 5 (or a component immovably fixed to it).

8 Figures la and 2a show a first arrangement of such attachment arrangement. In this instances, the stone chip protector 2 is fixed to the bottom section 11 of vibration damper tube 5 by a triple-welding. The stone 5 chip protector 2, the vibration damper 1 and a mounting element 6 for attaching the vibration damper 1 to a further component of the vehicle are welded together in a single operation. This creates a twist-proof connection, which is of great significance for components to be 10 attached to the vibration damper assembly or its constituent parts, such as, for example, a brake line. As may be gleaned best from Figures lb and 2b, the stone chip protector 2 is preferentially formed from sheet 15 metal as a single piece component. It is furthermore apparent that the contacting section 21 of stone chip protector 2 has at least one, but preferably a number of straps 3 that are flanged radially inwards at their respective terminal bottom ends thereby to provide 20 contact surfaces 31. Said contact surfaces 31 provide an axial support at the stone chip protector 2 for butting with the bottom section 11 of vibration damper tube 5. It will be further noted in all illustrated arrangements 25 and embodiments that the stone chip protector 2 has at least one mounting section (or portion) 23 at which further components may be secured, eg the above mentioned break line, which extends radially away from stone chip protector 2. 30 The arrangement of the stone chip protector 2 illustrated in figures 2a and 2b further comprises a positioning section (or portion) 24. Said positioning section 24 is 9 axially adjacent to protective section 22 on the upper side and serves to fix and define the axial position of a suspension component that encloses damper tube 5, for example a spring collar 26. A positioning section 24 may 5 also be formed at contacting section 21, however, such variant is not shown in the figures. Figures 3a and 3b depict an embodiment of a vibration damper 1 with stone chip protector 2 in accordance with 10 the present invention. In contrast to the arrangements in figures 1 and 2, the straps 3 do not include a radially inwardly bent flange (or butting portion) at their terminal ends. A further difference to the vibration damper - stone chip protector assemblies shown in figures 15 1 and 2 resides in the manner in which the chip protector 2 is fastened to / at the mounting (or fastening) element 6. As depicted in fig. 3a, the mounting element 6 is secured to the stone chip protector 2 by means of an integral connection, in this case a weld. The same type 20 of connection can also be used for securing and fixing the mounting element 6 to the damper tube 5 of the vibration damper 1. Consequently, the fixed position of the stone chip protector 2 at the vibration damper 1 is achieved indirectly via the mounting element 6. 25 It is furthermore envisaged to use other, not illustrated connection arrangements. For example, the straps 3 of the 10 stone chip protector 2 and the mounting element 6 could be modified to incorporate shape elements (or features) to enable protector 2 and element 6 to be screwed, clamped, riveted, or form-fittingly positively secured to 5 one another. Furthermore, a single piece embodiment comprising the stone chip protector 2 integrally formed with the mounting element 6 is also feasible, for example by using an appropriately shaped, cut and bent single sheet metal sheet. 10 11 Reference numbers 1 Vibration damper 5 11 Bottom section 2 Stone chip protector 21 Contacting section 22 Protective section 23 Mounting section 10 24 Positioning section 26 Spring collar 3 Straps 31 Contacting surface 4 Air gap 15 5 Damper tube 6 Mounting element

Claims

1. A stone chip protector for a vibration damper, comprising: 5 a protective section shaped to at least partially circumferentially surround a damper tube of a vibration damper whilst maintaining a radial air gap to the damper tube along at least part of the longitudinal extension of the damper tube; 10 at least one contacting section which axially delimits the protective section on at least one axial end thereof and which can be secured, at least indirectly, to the damper tube so as to fix the stone chip protector against axial and radial movement relative to the 15 vibration damper; and a mounting element by way of which the vibration damper is securable to a vehicle, characterised in that the stone chip protector features at least one strap, the terminal end of which is not radially inwardly flanged, 20 and the stone chip protector and mounting element are secured to one another by one of an integral, permanent connection such as welding, or the stone chip protector and the mounting element are made integral with one another, from sheet metal. 25

2. A stone chip protector according to claim 1, further comprising a positioning section that bounds the protective section on at least one axial end thereof, and in that the positioning section is devised for fixing the 30 axial position of a component disposed to surround the damper tube. 13

3. A stone protector according to claim 2, wherein the positioning section is formed by or as part of the contacting section. 5

4. A stone chip protector according to any one of claims 1 to 3, wherein the protective section is shaped to partially surround the damper tube when mounted on the damper and thereby leave a peripheral surface portion of the damper tube uncovered. 10

5. Vibration damper, comprising a damper tube and a stone chip protector in accordance with any one of claims 1 to 4, wherein the protective section at least partially surrounds the damper tube, and further characterised in 15 that the contacting section which axially delimits the protective section on one axial side is secured to the damper tube directly or indirectly such that the stone chip protector is fixed against axial and radial movement at the vibration damper. 20

6. Vibration damper with stone chip protector according to claim 5, wherein the stone chip protector is fastened at the vibration damper, preferably the damper tube, against rotation about a longitudinal axis of the damper 25 tube.

7. A stone chip protector according to any one of claims 1 to 6, further comprising at least one mounting section extending from the stone chip protector for 30 mounting of further components. 14

8. A stone chip protector according to any one of claims 1 to 7, wherein the stone chip protector is made in one piece from sheet metal. 5

9. A stone chip protector for vibration damper substantially as herein described with reference to figure 3b.

10. Vibration damper with stone chip protector 10 substantially as herein described with reference to figure 3a. 15 ZF FRIEDRICHSHAFEN AG WATERMARK PATENT AND TRADE MARKS ATTORNEYS P35151AU00