HYDRAULICLY DAMPING BEARING

Description

[0001] The present invention relates to a hydraulically damping bearing for mounting a motor vehicle assembly on a motor vehicle body, comprising a support and a supporting bearing which are connected to one another by a supporting spring made of an elastomeric material, wherein the supporting spring delimits a working chamber which is separated from a compensation chamber by a separating device, wherein the working chamber and the compensation chamber are filled with a fluid and are connected to one another via a damping channel introduced into the separating device.

[0002] A hydraulically damping mount of the type mentioned above is also called a hydro mount and is used to support a motor vehicle engine or transmission on a motor vehicle body in order to dampen the vibrations caused by road irregularities and to isolate acoustic vibrations.

[0003] The damping of the high-amplitude, low-frequency vibrations introduced by the vehicle engine is achieved via a hydraulic system consisting of a fluid-filled working chamber, a fluid-filled compensation chamber, and a damping channel. The introduced vibrations cause the suspension spring to move, building up hydraulic pressure within the working chamber. As a result of this pressure, fluid flows from the working chamber through the damping channel into the compensation chamber. The small diameter of the damping channel and the associated high mechanical ratio, which results from the equivalent displaced cross-section of the suspension spring in relation to the damping channel cross-section, dampen or cancel out the introduced vibrations.

[0004] The damping of high-frequency, low-amplitude vibrations, i.e., in the acoustically relevant range, is achieved via a diaphragm arranged between two nozzle discs. The diaphragm vibrates during high-frequency, low-amplitude vibrations, thus decoupling the damping via the damping channel. This reduces an increase in the dynamic stiffness of the bearing. DE 198 01 277 C2 discloses a hydraulically damping bearing with a diaphragm having a cavity defined by a wall made of elastic material, with a spacer device provided within the cavity to prevent the cavity from collapsing. Document US 49 25 162A shows all the features of the preamble of the appended claim 1.

[0005] The present invention is based on the object of creating a hydraulically damping mount which has an improved decoupling of vibrations in the acoustically relevant range.

[0006] To solve the problem, a hydraulically damping bearing with the features of claim 1 is proposed.

[0007] Advantageous embodiments of the hydraulically damping bearing are the subject of the dependent claims.

[0008] The hydraulically damping mount according to the invention for mounting a motor vehicle assembly on a motor vehicle body has a support and a supporting bearing which are connected to one another by a support spring made of an elastomeric material, wherein the support spring delimits a working chamber which is separated from a compensation chamber by a separating device, wherein the working chamber and the compensation chamber are filled with a fluid and connected to one another via a damping channel introduced into the separating device, wherein the separating device has two nozzle disks between which a first membrane and a second membrane are arranged, and wherein one of the membranes has at least one through-hole.

[0009] The two membranes, together with at least one through-hole, reduce the loss angle and the dynamic stiffness of the hydraulically damping bearing during high-frequency, small-amplitude vibrations.

[0010] As a result, the hydraulically damping mount exhibits improved decoupling in the acoustically relevant range. The through-hole allows the fluid to flow directly onto the diaphragm that does not have a through-hole. The two diaphragms are preferably arranged one above the other. In particular, the through-hole is aligned with an opening or flow-through opening in the nozzle disc that faces the working chamber. For the purposes of the invention, a through-hole is understood to be a hole that completely penetrates the diaphragm.

[0011] In an advantageous embodiment, the diaphragm has a plurality of through holes. The number of through holes can be used to adjust the function, i.e., the reduction of the loss angle and the dynamic stiffness of the bearing.

[0012] In an advantageous embodiment, the through-holes are evenly and / or unevenly spaced from one another. For example, a first group of through-holes can be evenly spaced from one another, whereas a second group of through-holes can be unevenly spaced from one another. Furthermore, a first group of through-holes and a second group of through-holes can also be evenly spaced from one another, with the first group of through-holes being unevenly or evenly spaced from the second group of through-holes.

[0013] In an advantageous embodiment, the through-holes form a hole circle. In particular, the through-holes are arranged as a hole circle around a through-opening provided in the membrane. Furthermore, a first group of through-holes can form a first hole circle, and a second group of through-holes can form a second hole circle.

[0014] In an advantageous embodiment, the diaphragm facing the working chamber has at least one through-hole. As a result, the other diaphragm is directly impacted by the fluid in the working chamber and the fluid in the compensation chamber, causing it to vibrate. In particular, the through-hole is aligned with an opening or flow-through opening in the nozzle disc.

[0015] In an advantageous embodiment, the through hole is round, rectangular or polygonal in cross section.

[0016] In an advantageous embodiment, at least one of the membranes has a structured surface. The loss angle and the dynamic stiffness of the bearing can be adjusted via the structured surface. In particular, the structured surface is designed as a shoe sole profile and / or a wave profile. Preferably, both membranes have a structured surface.

[0017] In an advantageous embodiment, the membranes are held loosely or clamped between the two nozzle discs. The membranes can be clamped by the nozzle discs at their outer edges and / or their inner edges. Furthermore, the membranes can be clamped across their entire surface between the two nozzle discs. Furthermore, the membranes can be clamped between the clamped outer edges and / or inner edges in sections between the nozzle discs.

[0018] In an advantageous embodiment, the membranes are made of an elastic material. Preferably, the membranes are made of an elastomer.

[0019] In an advantageous embodiment, a damper channel is incorporated into the separating device, which can be opened and closed by means of an actuator. The damper channel connects the working chamber with the compensation chamber. When the damper channel is open, a fluid column can oscillate in the damper channel, which lowers the dynamic spring rate of the hydraulically damping mount. The actuator can be designed as a switching device that can be switched electrically or pneumatically.

[0020] In the following, a hydraulically damping bearing and other features and advantages are explained in more detail using an exemplary embodiment, which is schematically illustrated in the figures. Here: Fig. 1 shows a vertical section through a hydraulically damping bearing; and Fig. 2 shows a plan view of a diaphragm with through holes.

[0021] In Fig. 1 a hydraulically damping bearing 10 is shown, which serves to mount a motor vehicle assembly (not shown), such as a motor vehicle engine or a transmission, on a motor vehicle body (not shown).

[0022] The hydraulically damping bearing 10 comprises a support bearing 12 and a support 14, which are connected to one another via a suspension spring 16 made of an elastomeric material. A fastening device (not shown), usually in the form of a bolt, is inserted into the support bearing 12, by means of which the hydraulically damping bearing 10 can be fastened to a motor vehicle assembly (not shown).

[0023] The static loads acting on the hydraulically damping bearing 10 are absorbed by the suspension spring 16. At the same time, the suspension spring provides acoustic insulation.

[0024] The support bearing 12, the support 14, and the suspension spring 16 define a working chamber 18, which is separated from a compensation chamber 22 by a separating device 20. The compensation chamber 22 is delimited to the outside by a compensating diaphragm 24. The working chamber 18 and the compensation chamber 22 are filled with a fluid and are fluidly connected to each other via a damping channel 26 incorporated in the separating device 20.

[0025] The working chamber 18, the compensation chamber 22, and the damping channel 26 form a hydraulic system that dampens or cancels the low-frequency vibrations with large amplitudes introduced by the motor vehicle engine. The introduced vibrations lead to a movement of the suspension spring 16, which builds up hydraulic pressure within the working chamber 18. As a result of this pressure, the fluid flows from the working chamber 18 via the damping channel 26 into the compensation chamber 22. Due to the small diameter of the damping channel 26 and the associated high mechanical transmission ratio, which results from the equivalent displaced cross-section of the suspension spring 16 in relation to the damping channel cross-section, the introduced vibrations are dampened or canceled.

[0026] As in Fig. 1As can be seen, the separating device 20 has a first nozzle disc 28 and a second nozzle disc 30. The first nozzle disc 28 is assigned to the working chamber 18, and the second nozzle disc 30 is assigned to the compensation chamber 22. The first nozzle disc 28 has a cylindrical projection 32 that engages an opening 34 in the second nozzle disc 30.

[0027] A first membrane 36 and a second membrane 38 made of an elastomeric material are arranged between the two nozzle discs 28, 30. The fluid in the working chamber 18 and the compensation chamber 22 flows against the membranes via flow openings 40 formed in the nozzle discs 28, 30.

[0028] The membranes 36, 38 are loosely received between the two nozzle discs 28, 30 and serve to decouple high-frequency, small-amplitude vibrations, i.e. in the acoustically relevant range in which the membrane 32 vibrates during high-frequency, small-amplitude vibrations, whereby damping via the damping channel 26 is decoupled.

[0029] As in Fig. 1 As can be seen, each of the membranes 36, 38 has a through-opening 42 through which the cylindrical projection 32 of the first nozzle disc 28 extends.

[0030] As in the Figures 1 and 2As can also be seen, the first membrane 36 has a plurality of through-holes 44 arranged around the through-opening 42 and forming a hole circle 46. The through-holes 44 are aligned with the flow openings 40 of the first nozzle disc 28 and face the working chamber 18. As a result, the second membrane 38 is directly exposed to the fluid in the working chamber 18 and the fluid in the compensation chamber 2.

[0031] Due to the two superimposed membranes 36, 38 and the through holes 40 introduced into the first membrane 36, the loss angle and the dynamic stiffness of the hydraulically damping bearing 10 can be reduced.

[0032] The membranes 36, 38 also have a structured surface 48, as shown in Fig. 2The structured surface 48 is approximately modeled on a shoe sole profile and reduces the loss angle and the dynamic stiffness of the hydraulically damping bearing 10.

[0033] As also in Fig. 1 As can be seen, a damper channel 50 is introduced into the separating device 20, which can also be referred to as an idle channel, and which can be opened and closed by means of an actuator designed as a switching device 52.

[0034] In the open position, the damper channel 50 reduces the dynamic bearing stiffness when the engine is idling. In the open position, the fluid column within the damper channel 50 can vibrate, so that the high-frequency engine vibrations occurring when the engine is idling are transmitted to a vehicle body (not shown) in a significantly reduced form due to the small effective spring rate.

[0035] When the damper channel 50 is closed, the hydraulically damping bearing 10 operates like a conventional bearing in that low-frequency vibrations with a large amplitude are damped by a fluid displacement within the damping channel 26 and high-frequency vibrations with a small amplitude are isolated or decoupled by means of the membrane 36.

[0036] The switching device 52 has a spring element 54 connected to the compensating diaphragm 24. The spring element 54 urges the compensating diaphragm 24 against the separating device 20 to close the damper channel 50. To open the damper channel 50, the switching device 52 is connected via a connection (not shown) to a vacuum source (not shown). By applying a vacuum, the compensating diaphragm 24 is moved away from the separating device 20 against the force of the spring element 54 to open the damper channel 50. List of reference symbols

[0037] 10 hydraulic damping bearing 12 support bearing 14 support 16 support spring 18 working chamber 20 separating device 22 compensation chamber 24 compensation diaphragm 26 damping channel 28 first nozzle disc 30 second nozzle disc 32 cylindrical projection 34 opening 36 first diaphragm 38 second diaphragm 40 through-flow opening 42 through-opening 44 through-hole 46 bolt circle 48 structured surface 50 damper channel 52 switching device 54 spring element

Claims

1. Hydraulically damping bearing (10) for mounting a motor vehicle unit on a motor vehicle body, having a support (14) and a supporting bearing (12) which are connected to one another by a supporting spring (16) made of an elastomeric material, the supporting spring (16) delimiting a working chamber (18) which is separated from an equalising chamber (22) by a separating device (20), the working chamber (18) and the equalising chamber (22) being filled with a fluid and being connected to one another via a damping channel (26) introduced into the separating device (20), the separating device (20) having two nozzle discs (28, 30), between which a first diaphragm (36) and a second diaphragm (38) are arranged, and one of the diaphragms (36, 38) having at least one through-hole (44), characterised in that the respective other diaphragm (36, 38) does not have a through-hole (44).

2. Hydraulically damping bearing (10) according to claim 1, characterised in that the diaphragm (36, 38) has a plurality of through-holes (44).

3. Hydraulically damping bearing (10) according to claim 2, characterised in that the through-holes (44) are evenly and / or unevenly spaced apart.

4. Hydraulically damping bearing (10) according to claim 2 or 3, characterised in that the through-holes (44) form a bolt circle (46).

5. Hydraulically damping bearing (10) according to one of the preceding claims, characterised in that the diaphragm (36, 38) facing the working chamber (18) has the at least one through-hole (44).

6. Hydraulically damping bearing (10) according to one of the preceding claims, characterised in that the through-hole (44) is round, rectangular or polygon-shaped in cross-section.

7. Hydraulically damping bearing (10) according to one of the preceding claims, characterised in that at least one of the diaphragms (36, 38) has a structured surface.

8. Hydraulically damping bearing (10) according to one of the preceding claims, characterised in that the two diaphragms (36, 38) are held loosely and / or clamped between the two nozzle discs.

9. Hydraulically damping bearing (10) according to one of the preceding claims, characterised in that the diaphragms (36, 38) are made of an elastic material.

10. Hydraulically damping bearing (10) according to one of the preceding claims, characterised in that an absorber channel (50) is introduced into the separating device (20), which can be opened and closed by means of an actuator.