Vibration damper with a tubular damping mass, a ring-shaped elastomer spring and a tubular base

Abstract

Vibration damper (1) with a tubular damper mass (2) which is elastically supported on a tubular base (4) via an annular elastomer spring (3), wherein - the damping mass (2) and the base (4) are arranged coaxially and have a common pipe axis (6), - the base (4) is arranged within the damping mass (2) except for a fastening end (5), - the elastomer spring (3) is chemically bonded to the base (4) and to a press-fit sleeve (11) which is pressed into a press fit (10) formed on the inner circumference of the damper mass (2), - the elastomer spring (3) - viewed in the direction of the tube axis (6) - the damper mass (2) supports its center of gravity (14) on both sides at the base (4), - the damping mass (2) at deflections relative to the base (4) that run transversely to the pipe axis (6) and exceed a limit value, strikes the base (4) in the region of its inner end (9) closer to the fastening end (5) of the base (4) via a buffer (13) made of elastomer material (12) chemically bonded to the base (4), characterized in that - the inner diameter of the damper mass (2) decreases continuously along the pipe axis (6), starting behind the press fit (10) and continuing to the inner end (9), - the outer diameter of the base (4) is constant over the entire length of the base (4) along the tube axis (6) and - the buffer (13) made of elastomer material (12) protrudes from the base (4) as a radial flange circumferential around the tube axis (6).

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to a vibration damper with a tubular damper mass which is elastically supported on a tubular base via an annular elastomer spring, wherein the vibration damper has the features of the preamble of independent patent claim 1.

[0002] Vibration dampers with elastomer springs are used to reduce vibrations in elements and structures, such as motor vehicle parts. For this purpose, a vibration damper base, to which its damping mass is elastically supported by the elastomer spring, is rigidly coupled to the respective structure or element. The elastic coupling of the damping mass to the base via the elastomer spring made of elastomer material dampens the vibrations of the damping mass relative to the base due to the internal damping of the elastomer material. This, in turn, broadens the effective range of the vibration damper by its natural frequency.

[0003] In modern vehicles, numerous vibration dampers are used in many different locations. The sum of their damper masses has no significant impact on the total mass of the respective vehicle, and the associated costs are also not insignificant. Vibration dampers must therefore be as efficient and cost-effective as possible, as well as compact in design, so that they require as little space as possible. STATE OF THE ART

[0004] A vibration damper with the features of the preamble of independent patent claim 1 is known from DE 20 2013 012 207 U1. Here, an inwardly directed stop flange is formed on the inner end of the damper mass, which is closer to the fastening end of the base. This stop flange strikes the base when the damper mass deflects relative to the base transversely to the tube axis and exceeds a limit value. A base coating made of elastomer material is provided as a stop buffer. The base, in turn, has at least one stop flange arranged next to the elastomer spring, which is coated with elastomer material to form a further stop for the damper mass on the base. The known vibration damper effectively limits the deflections of the damper mass relative to the base.However, it is complex to manufacture, both in terms of the production of the base and the damper mass itself, as well as in terms of the chemical bonding of the elastomer material to the base.

[0005] DE 10 2015 009 161 A1 discloses a vibration damper comprising a damper mass, a base, and an elastomer spring elastically coupling the damper mass to the base. A stop device is provided that dampens and limits deflections of the damper mass along a longitudinal axis of the vibration damper. The stop device is arranged on the base and extends from the base in a radial direction. The stop device has a damping body and a stiffening element that is directly connected to the base. At its inner end, closer to a fastening end of the base, an inwardly directed radial flange is formed on the inner circumference of the damper mass. This flange abuts the stop device and simultaneously limits a press fit for the elastomer spring in the damper mass. Here, too, the effort required to manufacture the vibration damper is considerable. The base does have a constant outer diameter.However, the stiffening element is directly connected to this. The damper mass has a similarly complex design to that described in DE 20 2013 012 207 U1; and the elastomer material vulcanized to the base is even more complex than that described in DE 20 2013 012 207 U1. Among other things, it is not vulcanized to an outer press-in sleeve, but instead features embedded metal stiffening elements. OBJECT OF THE INVENTION

[0006] The invention is based on the object of providing a vibration damper with the features of the preamble of independent patent claim 1, which can be produced cost-effectively and yet has sufficient functionality. SOLUTION

[0007] The object of the invention is achieved by a vibration damper having the features of independent claim 1. Preferred embodiments of the vibration damper according to the invention are defined in the dependent claims. DESCRIPTION OF THE INVENTION

[0008] A vibration damper according to the invention comprises a tubular damper mass that is elastically supported on a tubular base via an annular elastomer spring. The damper mass and the base are arranged coaxially and have a common tubular axis. Preferably, the damper mass and the base are rotational bodies and are thus rotationally symmetrical with respect to the common tubular axis. At least the damper mass and the base are usually manufactured on the basis of such rotational bodies and / or they exhibit only minor deviations from such rotational bodies.

[0009] The base is arranged within the damper mass except for one attachment end, via which the base is rigidly coupled to an element or structure whose vibration is to be reduced. The elastomer spring is chemically bonded to the base and to a press-fit sleeve, which is pressed into a press fit formed on the inner circumference of the damper mass. Typically, the elastomer spring is vulcanized to both the base and the press-fit sleeve. With regard to the function of the vibration damper according to the invention, the press-fit sleeve is part of the damper mass. However, it only increases the physical mass of the damper mass insignificantly, i.e., usually by no more than one percent.

[0010] The elastomer spring supports the damper mass at the base—viewed along the tube axis—on both sides of the damper mass's center of gravity, which coincides with the tube axis. The damper mass is thus elastically mounted at the base, particularly for tilting vibrations around its center of gravity, during which it is tilted relative to the base.

[0011] In the event of deflections relative to the base, which occur, for example, during tilting vibrations, are perpendicular to the tube axis and exceed a certain limit, the damper mass impacts the base in the area of ​​its inner end closest to the base's mounting end via a buffer made of elastomer material chemically bonded to the base. Here, too, the elastomer material is typically vulcanized to the base.

[0012] In the vibration damper according to the invention, the inner diameter of the damper mass decreases continuously along the tube axis in a region that begins directly behind the press fit and ends at the inner end. The press fit, behind which this region begins, ends with the press-fit sleeve or a step against which the press-fit sleeve strikes or would strike upon further pressing into the press fit. The continuous progression of the inner diameter means that there is no step here and no stop flange is formed on the inner circumference of the damper mass. This significantly simplifies the manufacture of the damper mass.

[0013] The manufacture of the base is also simplified in the vibration absorber according to the invention in that the outer diameter of the base is constant over the entire length of the base along the tube axis. In order to ensure that the absorber mass strikes the base even in the event of deflections of the absorber mass relative to the base that run transversely to the tube axis and exceed the limit value, the buffer made of elastomer material protrudes from the base as a radial flange surrounding the tube axis. Via this buffer, the inner circumference of the absorber mass strikes the base relatively softly if its deflections exceed the limit value. This prevents the transmission of vibrations of the absorber mass to the base and thus the excitation of secondary vibrations of the element or structure to which the base is rigidly coupled.The buffer formed as a radial flange in the vibration absorber according to the invention as an elastomer material can also be interpreted as a second elastomer spring connected between the absorber mass and the base, which only becomes effective when the deflections of the absorber mass relative to the base exceed the limit value and which increases the overall stiffness of the elastic support of the absorber mass at the base for deflections above the limit value.

[0014] The buffer made of elastomer material, which is designed as a radial flange, can easily be formed in the desired shape, i.e. in particular at the desired height above the base, when the elastomer material is vulcanized to the base.

[0015] Although the vibration damper according to the invention does not have an inner flange on the inner circumference of the damper mass, nor an outer flange on the outer circumference of the base as part of the damper mass or base, the vibration damper according to the invention still provides sufficient protection against loss of the damper mass in the event of the elastomer spring becoming detached from the base and / or the press-fit sleeve. For this purpose, a sufficiently significant reduction in the inner diameter of the damper mass behind the press fit is sufficient that the elastomer spring, which is held on the base by a head of a fastening screw projecting radially beyond the base or a washer arranged between this head and the base, cannot emerge from the damper mass at its inner end. Furthermore, the head of the fastening screw or the washer can also be of such a large diameter that it cannot emerge from the damper mass at its inner end.To achieve this, the base does not need to be so long that the head of the fastening screw or the washer is positioned outside the damper mass, preventing the damper mass from striking the head of the fastening screw or the washer. Rather, the base can be so short that the head of the fastening screw or the washer is positioned so close to the elastomer spring that the damper mass does not strike the head or the washer, because the greatest deflections of the damper mass occur transversely to the tube axis relative to the base at the ends of the damper mass.

[0016] In the vibration damper according to the invention, the base is usually designed to accommodate a fastening screw whose head rests on a support end of the base opposite the fastening end. The support end of the base can be offset into the damper mass by at least one, one and a half, or two inner diameters of the base relative to the outer end of the damper mass closer to the support end. The head of the fastening screw thus lies completely within the damper mass, yet the damper mass is prevented from striking the head of the fastening screw or a washer arranged between it and the base. In addition, the base is only as long as necessary. For all of these reasons, it is preferred if the support end of the base is offset into the damper mass by at least two inner diameters of the base relative to the outer end of the damper mass.

[0017] Preferably, the inner diameter of the damper mass decreases linearly along the rotor axis, starting directly behind the press fit and extending to the inner end. This means that the inner circumference in this area is conical in shape with a constant cone angle. Specifically, this cone angle can be between 6° and 15°. Preferably, it is between 7° and 10° or approximately 8°. This configuration of the damper mass on its inner circumference is easy to implement.

[0018] This also applies to the further design details of the damper mass described below. It is preferred if the inner diameter of the damper mass runs continuously along the tube axis, beginning at the outer end and extending into the press fit, and decreases monotonically. A continuous progression has no steps; and a monotonous decrease in the inner diameter means that it either remains constant or decreases, i.e., it does not increase in the defined direction.

[0019] Specifically, the inner diameter of the damper mass can decrease linearly or remain constant along the pipe axis, starting directly behind a steeper insertion ramp at the outer end and extending directly in front of a further ramp leading into the press fit. A further cone angle of the inner circumference of the damper mass in the area of ​​the insertion ramp can be 20° to 40° or approximately 30°, and a further cone angle of the inner circumference of the damper mass in the area of ​​the further ramp can be 40° to 70° or 50° to 65° or approximately 60°.

[0020] The inner diameter of the damper mass in the press fit is preferably constant. Towards the inner end of the damper mass, the press fit can generally end with a step against which the press-fit sleeve can strike.

[0021] Preferably, however, the inner diameter of the damper mass decreases continuously, i.e., continuously, from its outer end to its inner end. This makes the damper mass particularly easy to manufacture. The press-fit sleeve can be pressed into the damper mass to a defined depth. Since the press-fit sleeve must be firmly seated in the damper mass in both directions of the tube axis anyway, it is not necessary for the press fit to be limited by a step on one side.

[0022] In the vibration damper according to the invention, a minimum length of the elastomer spring along the tube axis is preferably between one and a half and two and a half, i.e., approximately two, thicknesses of the elastomer spring between the base and the press-in sleeve. This provides ideal support for the damper mass at the base for tilting vibrations around its center of gravity. This is especially true when the inner diameter of the press-in sleeve and the length of the damper mass are in a ratio of 0.8 to 2 to 1.2 to 2, i.e., approximately 1 to 2.

[0023] In the vibration damper according to the invention, an inner diameter of the press-in sleeve and an outer diameter of the base can be in a ratio of 2 to 0.8 to 2 to 1.2, ie, approximately 2 to 1. Furthermore, the inner diameter of the press-in sleeve and an outer diameter of the damper mass can be in a ratio of 1 to 1.3 to 1 to 1.8, ie, approximately 2 to 3.

[0024] The minimum length of the buffer made of elastomer material along the tube axis and the radial extension of the buffer above the base in the vibration absorber according to the invention are preferably in a ratio of 1 to 1.5 to 1.5 to 1 or of 1 to 1.2 to 1.2 to 1, ie of approximately 1 to 1. The buffer is thus sufficiently resistant to buckling so that when the absorber mass strikes, the elastomer material is essentially subjected to compressive stress.

[0025] An outer diameter of the damper mass can increase between its inner end and its outer end in the vibration damper according to the invention. Specifically, the outer diameter can increase in steps in this direction. This increase can compensate for the decrease in the inner diameter of the damper mass in the opposite direction with respect to the mass distribution of the damper mass around its center between its inner end and its outer end. Furthermore, the center of the elastomer spring can be offset from a geometric center of the damper mass towards its inner end. Furthermore, it is possible to provide the damper mass with any desired grooves and / or steps on its outer circumference, for example to prevent the damper mass from striking adjacent components, particularly before it is decelerated by the buffer made of elastomer material.

[0026] Preferably, the elastomer spring supports the absorber mass - viewed in the direction of the tube axis - in the vibration absorber according to the invention point-symmetrically to the center of gravity of the absorber mass at the base.

[0027] The basis of the vibration damper according to the invention can be a cut-to-length pipe section, a pressed part, an injection-molded part, or a cast part, each in particular made of metal. The damper mass, in contrast, can be, in particular, a turned metal part or a turned metal cast part. The design details of the inner and outer circumference of the damper mass described above can be easily realized by turning an already tubular blank.

[0028] The press-fit sleeve of the vibration damper according to the invention is typically a cut-to-length tube section or a rolled-up section of metal sheet. The elastomer spring and the buffer can be made of the same elastomer material and thus vulcanized to the base in a simple mold.

[0029] Advantageous developments of the invention emerge from the patent claims, the description, and the drawings. The advantages of features and combinations of several features mentioned in the description are merely exemplary and can be effective alternatively or cumulatively, without the advantages necessarily being achieved by embodiments according to the invention. Without altering the subject matter of the appended patent claims, the following applies to the disclosure content of the original application documents and the patent: further features can be found in the drawings—in particular, the illustrated geometries and the relative dimensions of several components to one another, as well as their relative arrangement and operative connection.The combination of features of different embodiments of the invention or of features of different patent claims is also possible, deviating from the chosen references of the patent claims, and is hereby encouraged. This also applies to features shown in separate drawings or mentioned in their description. These features can also be combined with features of different patent claims. Likewise, features listed in the patent claims can be omitted for further embodiments of the invention.

[0030] The number of features mentioned in the patent claims and the description is to be understood as meaning that exactly this number or a greater number than the stated number is present, without the need for the explicit use of the adverb "at least." Thus, for example, if an elastomer material is mentioned, this is to be understood as meaning that exactly one elastomer material, two elastomer materials, or more elastomer materials are present. These features can be supplemented by other features or be the only features that the respective vibration damper has.

[0031] The reference signs contained in the patent claims do not represent a limitation of the scope of the subject-matter protected by the patent claims. They serve solely to make the patent claims easier to understand. BRIEF DESCRIPTION OF THE CHARACTERS

[0032] In the following, the invention is further explained and described with reference to preferred embodiments shown in the figures. Fig. 1 is a side view of a vibration damper according to the invention. Fig. 2 shows the vibration absorber according to Fig. 1 with to Fig. 1 vertical view of an outer end of its absorber mass. Fig. 3 is a longitudinal section through the vibration absorber according to the Fig. 1 and Fig. 2. Fig. 4 is a longitudinal section only through the absorber mass of the vibration absorber according to the Fig. 1 to 3. FIGURE DESCRIPTION

[0033] The one in the Fig. The vibration damper 1 shown in Figures 1 to 3 has a damper mass 2 which is elastically supported on a base 4 via an elastomer spring 3. The base 4 is a simple hollow cylinder with a constant inner and outer diameter. Except for a fastening end 5, it lies within the tubular damper mass 2. The damper mass 2 and the base 4 are arranged coaxially to one another around a common tubular axis 6. A supporting end 7 of the base 4, against which a head of a fastening screw can rest in order to fix the fastening end 5 to an element or structure whose vibrations are to be reduced, is offset into the damper mass relative to an outer end 8 of the damper mass. In contrast, the fastening end 5 projects slightly beyond the opposite inner end 9 of the damper mass.The inner diameter of the tubular damper mass 2 decreases monotonically from the outer end 8 to the inner end 9, with a press fit 10 being formed approximately halfway there, into which a press-in sleeve 11 is pressed. The elastomer spring 3 is vulcanized to the press-in sleeve 11 as well as to the base 4. A buffer 13 in the form of a radial flange protruding from the base 4, made of the same elastomer material 12 as the elastomer spring 3, is vulcanized to the base 4 near the fastening end 5 but within the damper mass 2. The damper mass 2 strikes this buffer 13 when its inner end 9 approaches the damper mass 4 beyond a limit value during deflections relative to the damper mass 4 transversely to the tube axis 6. This particularly concerns deflections of the absorber mass 2 relative to the base 4 during tilting oscillations around a center of gravity 14 of the absorber mass, to which the elastomer spring 3 is designed approximately point-symmetrically.To compensate for the smaller inner diameter of the damper mass 2 at its inner end 9 compared to its outer end 3, the outer diameter of the damper mass 2 increases in a step between the inner end 9 and the outer end 8 before decreasing again at the outer end 8. Furthermore, the center of the elastomer spring 3 is slightly offset from the geometric center of the damper mass between its ends 8, 9 toward the inner end 9.

[0034] Fig.4 shows details of the design of the inner circumference of the damper mass 2, i.e. the course of its inner diameter between its outer end 8 and its inner end 9. First, an insertion ramp 15 is provided at the outer end 8 for easy insertion of the press-in sleeve 11 into the interior of the damper mass 2. A cone angle 16 of the inner circumference of the damper mass 2 in the region of this insertion ramp 15 is approximately 30°. This is followed by an area with an approximately constant inner diameter of the damper mass 2. This area extends to a further ramp 17 with a cone angle 18 of the inner circumference of approximately 60°, to which the press fit 10, again with a constant inner diameter, is connected. The press fit 10 ends at a step 20 of the inner circumference of the absorber mass 2. Behind the step 20 up to the inner end 9, the inner diameter of the absorber mass 2 decreases linearly, with a cone angle 19 of the inner circumference being approximately 8° here.In a preferred embodiment of the damper mass 2, however, the step 20 is not present. Rather, the inner diameter of the damper mass 2 preferably has a continuous profile without steps between its ends 8 and 9. The press fit 10 then ends at the maximum depth to which the press-in sleeve 11 is pressed into the damper mass 2. LIST OF REFERENCE SYMBOLS 1 vibration absorber 2 absorber mass 3 elastomer spring 4 Base 5 Fastening end 6 Pipe axis 7 Supporting 8 Outer end 9 inner end 10 Press fit 11 Press-in sleeve 12 Elastomer material 13 buffers 14 Focus 15 insertion ramp 16 cone angles 17 additional ramps 18 cone angles 19 Cone angle 20th level

Claims

[1] Vibration damper (1) with a tubular damper mass (2) which is elastically supported on a tubular base (4) via an annular elastomer spring (3), wherein - the absorber mass (2) and the base (4) are arranged coaxially and have a common tube axis (6), - the base (4) is arranged within the damper mass (2) except for one fastening end (5), - the elastomer spring (3) is chemically bonded to the base (4) and to a press-fit sleeve (11) which is pressed into a press fit (10) formed on the inner circumference of the damper mass (2), - the elastomer spring (3) - viewed in the direction of the tube axis (6) - supports the absorber mass (2) on both sides of its center of gravity (14) on the base (4), - the damping mass (2) in the event of deflections relative to the base (4) which run transversely to the tube axis (6) and exceed a limit value, strikes the base (4) in the region of its inner end (9) closer to the fastening end (5) of the base (4) via a buffer (13) made of elastomer material (12) chemically bonded to the base (4), characterized by , that - an inner diameter of the absorber mass (2) decreases along the pipe axis (6), starting behind the press fit (10) and up to the inner end (9) with a continuous course, - an outer diameter of the base (4) is constant over the entire length of the base (4) along the tube axis (6) and - the buffer (13) made of elastomer material (12) protrudes from the base (4) as a radial flange surrounding the pipe axis (6). [2] Vibration damper (1) according to claim 1, characterized byin that the base (4) is designed for the penetration of a fastening screw, the head of which is supported on a support end (7) of the base (4) opposite the fastening end (5), wherein the support end (7) of the base (4) is offset into the absorber mass (2) by at least one, one and a half or two inner diameters of the base (4) compared to the outer end (8) of the absorber mass (2) closer to the support end (7). [3] Vibration damper (1) according to one of the preceding claims, characterized by that the inner diameter of the absorber mass (2) decreases linearly along the tube axis (6), starting behind the press fit (10) and up to the inner end (9). [4] Vibration damper (1) according to claim 3, characterized by that a cone angle (19) of the inner circumference of the absorber mass (2) starting behind the press fit (10) and up to the inner end (9) is between 6° and 15° or between 7° and 10°. [5] Vibration damper (1) according to one of the preceding claims, characterized by that the inner diameter of the absorber mass (2) runs continuously and monotonically decreases along the tube axis (6), starting at the outer end (8) and up to the press fit (10). [6] Vibration damper (1) according to claim 5, characterized by that the inner diameter of the absorber mass (2) decreases linearly or is constant along the tube axis (6), starting behind a steeper insertion ramp (15) at the outer end (8) and up to a further ramp (17) leading into the press fit (10). [7] Vibration damper (1) according to claim 6, characterized by that a further cone angle (16) of the inner circumference of the absorber mass (2) in the region of the insertion ramp (15) is 20° to 40° and / or that a further cone angle (18) of the inner circumference of the absorber mass (2) in the region of the further ramp (17) is 40° to 70° or 50° to 65°. [8] Vibration damper (1) according to one of the preceding claims, characterized by that the inner diameter of the absorber mass (2) in the press fit (10) is constant. [9] Vibration damper (1) according to one of the preceding claims, characterized by that the inner diameter of the absorber mass (2) decreases along the tube axis (6) from its outer end (8) to its inner end (9) in a continuous manner. [10] Vibration damper (1) according to one of the preceding claims, characterized by that a minimum length of the elastomer spring (3) along the tube axis (6) is between one and a half and two and a half thicknesses of the elastomer spring (3) between the base (4) and the press-in sleeve (11). [11] Vibration damper (1) according to one of the preceding claims, characterized by that an inner diameter of the press-in sleeve (11) and a length of the absorber mass (2) are in a ratio of 0.8 to 2 to 1.2 to 2. [12] Vibration damper (1) according to one of the preceding claims, characterized bythat an inner diameter of the press-in sleeve (11) and an outer diameter of the base (4) are in a ratio of 2 to 0.8 to 2 to 1.2 and / or that the inner diameter of the press-in sleeve (11) and an outer diameter of the absorber mass (2) are in a ratio of 1 to 1.3 to 1 to 1.

8. [13] Vibration damper (1) according to one of the preceding claims, characterized by that the minimum length of the buffer (13) along the tube axis (6) and the radial extension of the buffer (13) above the base (4) are in a ratio of 1 to 1.5 to 1.5 to 1 or of 1 to 1.2 to 1.2 to 1. [14] Vibration damper (1) according to one of the preceding claims, characterized by that the elastomer spring (3) - viewed in the direction of the tube axis (6) - supports the absorber mass (2) point-symmetrically to its center of gravity (14) on the base (4). [15] Vibration damper (1) according to one of the preceding claims, characterized bythat the base (4) is a cut-to-length pipe section, a pressed part, an injection-molded part or a cast part made of metal. [16] Vibration damper (1) according to one of the preceding claims, characterized by that the damper mass (2) is a turned metal part or a turned cast part. [17] Vibration damper (1) according to one of the preceding claims, characterized by that the press-in sleeve (11) is a cut-to-length pipe section or a rolled-up sheet metal section. [18] Vibration damper (1) according to one of the preceding claims, characterized by that the elastomer spring (3) and the buffer (13) made of the same elastomer material (12) are vulcanized to the base (4).

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