DE102008057577A1 - Elastomer engine bearing i.e. mechatronical rigidity adaptive engine bearing, for motor vehicle, has circular bearing inserted between two base plates, and pipe piece supporting circular bearing and adjusting elasticity of circular bearing - Google Patents

Abstract

The bearing has a circular bearing (50) inserted between two base plates (51, 52), and a pipe piece (54) supporting the circular bearing and adjusting an elasticity of the circular bearing. The circular bearing is formed as a single piece, and made of rubber. The base plates are connected to body and engine sides of a motor vehicle, respectively. The pipe piece includes adjustable jaws movable in a radial direction against a lateral surface of the circular bearing. An adjusting wheel is driven by an actuator i.e. electric motor, under interconnection of a transmission. An independent claim is also included for a method for varying spring rigidity of an elastomer engine bearing of a motor vehicle.

Description

The The invention relates to an elastomeric bearing, in particular an engine mount for a motor vehicle, according to the generic term of the first Claim and a method for varying its spring stiffness.

Elastomeric bearings lie in the connection of a chassis, transmission or engine part to the vehicle body. They are in different embodiments known. You can oscillate or relative movements allow and dampen between the connecting parts.

motor bearings take both the static and dynamic motor holding forces when driving on, as well as dampen the resulting low-frequency Vibrations of the engine. In addition, they should be the transfer from acoustic vibrations that radiate from the engine to the bodywork and thus spread the passenger compartment, prevent. Therefore Such bearings should be in the low frequency and high frequency range different properties in terms of stiffness and damping exhibit. This requires considerable in the design of such bearings Compromises that in unfavorable conditions far from the respective Optimum can lie. Good results have been achieved so far hydraulically damped engine mounts reached a high Damping low-frequency vibrations cause and at the same time enable a targeted decoupling of high-frequency vibrations. But even in such camps, the properties are in low-frequency and in the high-frequency range are not independent of each other adjustable, whereby the vote on the respectively required Values become very expensive. In addition, it is in such hydraulically damped engine mounts in general a Change in the dynamic spring stiffness only in the axial, d. H. possible in the vertical direction while this remains largely unchanged in the radial direction, so that a controlled spring stiffness change, the does not adapt to the respective operating conditions is. Switchable hydraulic bearings are adjusted or adjusted for the idling operation electrically or by negative pressure. This is very slow and is in the range of 2 to 5 seconds. In addition, can only one attenuation can be changed. Usually causes a change in stiffness of a motor bearing also always a damping change.

The U.S. Patent 2,154,586 describes elastomeric bearings with rubber bodies connected in series, which are pressed together at high loads so far that the surrounding housing parts increasingly come into contact with the rubber bodies. By this Dehnbehinderung the form factor is changed, which indicates the ratio of the loaded, force inducing, to the free surface of the rubber. The elastic modulus of a rubber bearing is in turn dependent on this form factor. If this increases, the modulus of elasticity also increases. Thus, although a change in the spring stiffness of such a bearing is possible, but only depending on the particular load and without additional intervention options from the outside.

task The present invention is a pure elastomeric bearing and to provide a method for its operation, with which the spring stiffness of such a warehouse, depending on given operating parameters, can be varied continuously, in the sense that a such bearings at low speeds and thus large vibration amplitudes, especially at idle, relatively soft and at higher Operating speeds is relatively hard.

The Task is according to the invention with the features of claim 1. A method of operating the elastomeric bearing describes claim 9. Further embodiments of the invention result from the additional subclaims.

To The invention is an elastomeric bearing, in particular an engine mount or a chassis bearing of a motor vehicle, with at least one between at least two support bodies introduced spring / damper body, the at least one other support body can be supported if necessary, characterized in that that the further support body, the spring / damper body can support so that its elasticity adjustable being affected.

This has the advantage that the spring / damper body in response to predetermined operating parameters, temporarily, by means of different sized, externally applied force can be charged so that its modulus of elasticity can be adjusted according to the desired spring / damping properties of the elastomer bearing. Thus, it is possible to vary the spring stiffness of the elastomer bearing according to predetermined requirements and operating parameters. An expedient operating parameter here is, for example, the engine speed, depending on the height then a soft and at full load a hard characteristic of the elastomeric bearing can be set at idle. Thus, motor-excited vibrations are prevented over a best possible vibration isolation by the soft, undamped setting of the elastomer bearing and vibration excitation of the engine by road bumps on the other hand prevented by a rigid connection of the engine to the chassis. An engine mount which can be adapted individually to the operating conditions of the motor vehicle by means of such an elasto according to the invention mer-stock also opens up a great potential for improving ride comfort. Useful here is the consideration of engine speed, wheel acceleration and / or front axle carrier acceleration.

One Such mechatronic adaptive engine mount is advantageous able, with constant damping, its rigidity to change significantly, for example very quickly to increase the factor 5. Depending on the actuator dynamics can have an adjustment time of less than 200 milliseconds, from the ground up Maximum rigidity can be achieved. Due to a low elastomeric Basic damping, low selectable basic stiffness and a natural frequency shift results in a good acoustic Behavior and the occurrence of resonances is avoided.

In Further preferred embodiments of the invention is the Spring / damper body integrally formed, in particular consisting of a single material, in particular made of rubber. Here are also inserts in other technical Areas conceivable. Such a development of the invention has advantageously a simple structure, which also requires that The basic stiffness of the elastomer bearing is easy to install a rubber insert with other material properties to other circumstances can be adjusted. Especially if the elastomeric bearing characterized in that its a supporting body Body side, the other support body motor side is connected to the motor vehicle and that the two support body essentially one side in each case, in particular opposite ones Sides, of the spring / damper body in their extensibility influence, wherein the further support body at least another side of the spring / damper body in their extensibility is a use of simply constructed spring / damper bodies at easy adjustment of the spring stiffness possible. This is additionally supported by that the spring / damper body substantially has the shape of a cylinder or cuboid or polygon its bases of the one and the other support body be influenced in their elasticity, with the other Support body, the lateral surface or at least one side of the lateral surface of the spring / damper body influenced in their elasticity.

One simple construction of the adjusting device is made possible if the further support body consists of at least two, especially evenly, over the lateral surface, or over individual sides of the lateral surface, of the spring / damper body distributed, essentially against the expansion direction of the spring / damper body, especially uniform, adjustable support body elements consists. In particular, if the further support body made essentially in the radial direction against the lateral surface the spring / damper body adjustable support body elements exists, and / or if the support body elements as adjusting jaws, in particular six pieces, at her an end against the lateral surface of the spring / damper body hinged around this, in one the spring / damper body at least partially surrounding housing are stored and at its other end by a respective ball head in the radial direction are displaceable, by one of an adjusting to substantially 20-30 angle degree back and forth rotatable adjusting ring, by placing each ball head in a direction to the housing substantially guided secant groove extending the adjusting ring is, the adjusting wheel can easily by an actuator, in particular a Electric motor, in particular with the interposition of a transmission, are driven.

One preferred method for varying the spring stiffness of an elastomeric bearing, in particular an engine mount for motor vehicles is characterized characterized in that a control unit, depending of route-specific input variables, in particular Engine speed and / or vehicle speed and / or road condition or Bounce / Ausfederdaten the chassis, for example, the wheel acceleration, a necessary instantaneous value of the form factor for the Support of the spring / damper element by the Support body elements of the further support body calculated and this instantaneous value of the form factor on the spring / damper element adjusted by activation, in particular energization, of the actuator, especially with a control frequency up to 300 1 / min. This frequency corresponds to a full stiffness adjustment. Small stiffness increases can be evoked much faster. Also depending on the actuator, especially of its energization and tension, here is a clear higher control frequency can be achieved. 300 1 / min correspond 200 ms, as time to complete increase stiffness, about five times. Usually will but not required the full stiffness adjustment. from that follows a much higher possible control frequency than 300 1 / min.

In the following the invention is based on a schematic diagram in 1 and a preferred embodiment in the 2 and 3 further explained, which show a section and a spatial view, partially in exploded view, of an inventive, adjustable in its spring stiffness elastomer bearing. In both figures of the embodiment, the same elements are denoted by the same reference numerals and essential to the invention may be all the features described in more detail.

1 shows a schematic representation of an elastomeric round bearing 50 with a bulge 53 due to an axial load F, with a piece of pipe 54 to increase the rigidity of the round bearing 50 can be brought into contact so that the form factor changes.

If an elastomer block is subjected to a force, the elastomeric incompressibility results in a local expansion of the surfaces which are not or less heavily loaded. The reason for this is the constant volume of elastomers under load. The effect described is therefore due to the viscoelastic behavior of elastomeric materials, which is in principle comparable to a hydraulic ratio. This phenomenon is particularly easy to visualize with a cylindrical elastomer element or with a circular bearing 50 with metallic base plates 51 . 52 , corresponding 1 , The round bearing 50 stands on the circular base plate 51 and gets on the opposite base plate 52 loaded with a vertical force F to the surface.

Due to the mentioned volume constancy of the loaded elastomer body (round bearing 50 ) creates a uniform bulge on condition of a homogeneous material distribution 53 the peripheral surface of the circular bearing 50 ,

In order to realize a change in rigidity, the resulting bulge is 53 on the circumference of the elastomer body (round bearing 50 ) limit or block. This can be done, for example, via a circumferentially variable clamp or as in 1 by a height of the elastomeric body (round bearing 50 ) displaceable piece of pipe 54 respectively. The larger with the surface of the elastomeric body (circular bearing 50 ) in contact surface of the pipe section 54 , the higher the achievable stiffness change.

• – ein von oben oder unten über das Elastomer verschiebbarer Ring mit konstantem Querschnitt oder
• – ein Ring oder eine Klammer mit veränderlichem Querschnitt oder
• – Flächen, die über eine Aktuatorik die Ausbauchung 53 einschränken (z. B. auch bei einem quaderförmigen Elastomer) oder
• – Verdrehen eines Formelementes mit einem entsprechend geometrisch angepassten Elastomer.

By completely blocking the bulge 53 of the round camp 50 (d = 50 mm, h = 60 mm) can be achieved more than 15-fold increase in stiffness with a constant quasi-static load of F = 2500 N. This blocking the bulge 53 can be generated by different designs. Possible versions are:

• A ring of constant cross-section or sliding over the elastomer from above or below
• A ring or clip of variable cross section or
• - Surfaces that have an actuator the bulge 53 restrict (eg, even with a cuboid elastomer) or
• - Turning a mold element with a corresponding geometrically adapted elastomer.

In this way it is possible, an elastomeric bearing, in particular an engine mount for a motor vehicle, with at least one between at least two support bodies (base plates 51 . 52 ) introduced spring / damper body (round bearing 50 ), which via at least one further support body (pipe section 54 ) can be supported in case of need to provide, which is characterized in that the further supporting body (pipe section 54 ) the spring / damper body (round bearing 50 ) can be adjustably supported in its elasticity. The spring / damper body (round bearing 50 ) can be made in one piece from a material, for example made of rubber. A corresponding engine mount, whose one supporting body (base plate 52 ) Body side, the other support body (base plate 51 ) is connected on the motor side with the motor vehicle, in which the two support body (base plates 51 . 52 ) substantially each one side, in particular opposite sides of the spring / damper body (circular bearing 50 ) influence in their elasticity, can then be designed so that the further support body (pipe section 54 ) at least one further side of the spring / damper body (circular bearing 50 ) in their elasticity. In this case, the spring / damper body (round bearing 50 ) has substantially the shape of a cylinder or cuboid or Vielkants whose base surfaces of the one and the other support body (base plates 51 . 52 ) are influenced in their elasticity, wherein the further support body (pipe section 54 ) the lateral surface or at least one side of the lateral surface of the spring / damper body (circular bearing 50 ) in their elasticity.

In the mechatronic stiffness adaptive engine mount of the preferred embodiment in the 2 and 3 , is a mechatronic chassis component that is capable of significantly increasing stiffness, for example by a factor of 5, while maintaining damping. 2 shows this in a cut and 3 in a spatial view, partially in exploded view. The attached to the figures list of reference numerals refers to this embodiment.

The basic function of the elastomeric bearing is to use a suitable mechanical and actuator technology to create a rubber spring 17 to restrict in their transverse deformation and thereby achieve the significant increase in stiffness in the vertical direction. This limitation of transverse deformation is achieved by means of six adjustable jaws 38 achieved, the ring around the rubber spring 17 are arranged. The adjusting jaws 38 can each have a ball head 37 which is attached to each cheek in a base plate 41 mounted bolts 39 open and closed. The six ball heads 37 each run in a groove 45 in an adjusting ring 22 is milled. This adjusting ring 22 can via a Verstellzahnrad 31 , an intermediate gear 29 and a drive gear 28 with the help of a suitable rotary motor as an actuator 3 rotated and thus adjusted. This causes the folding movement of the adjusting jaws 38 ,

The actuator 3 is by a suitable clamping device 4 , via a connection 30 , to a storage base plate 23 tethered. For storage of the adjusting ring 22 , the shaft of the intermediate gear 29 and the drive shaft 8th be deep groove ball bearings 5 . 12 as well as a thin ring bearing 20 used.

In not shown vehicle, the left and right engine mounts, analogous to the conventional engine mount, connected to the front axle and the Motortragböcken. The connection to the front axle is via a suitable adapter according to the prior art on the bearing base plate 23 , The engine mounts are with the rubber spring 17 screwed.

Depending on the actuator dynamics may be for the rubber spring 17 Adjustment times of less than 200 ms, from basic to maximum rigidity, can be achieved. Reference numerals Fig. 2, Fig. 3 1 Hexagon bolt M8x20 - A2 - 70 2 Washer 8 - 200 HV - A4 3 actuator 4 Clamping device actuator 5 Deep groove ball bearing 2-row 6 Secure deep groove ball bearing 2-row 7 Huelse drive shaft actuator 8th Drive shaft actuator 9 Hex bolt M8x50 - 8.8 - ZNS3 10 Washer 8 - 200 HV - ZNS3 11 Clamp-drive gear 12 Deep groove ball bearings 13 Shaft intermediate gear 14 Circlip intermediate gear 15 Hexagon bolt M6x25 - 8.8 - ZNS3 16 Washer 6 - 200 HV - ZNS3 17 rubber spring 18 Circlip Duennringlager shaft 19 Circlip Duennringlager bore 20 Thin section bearings 21 Außenhuelle 22 adjusting 23 baseplate 24 Washer 10 - 200 HV - ZNS3 25 Cylinder head screw M10x55 - 8.8 - ZNS3 26 Hex nut AM - 10 - 8 - ZNS3 27 Washer 10 - 200 HV - ZNS3 28 drive gear 29 intermediate gear 30 Connection actuator 31 recliner 32 Bearing shell actuator 33 Cylinder head screw M5x40 - 8.8 - ZNNIV SI 34 Washer 5 - 200 HV - ZNS3 35 Hex nut M8x50 - 8.8 - ZNS3 36 Washer 5 - 200 HV - ZNS3 37 ball head 38 adjustable jaw 39 Bolt adjusting jaw 40 Circlip Bolt Adjusting jaw 41 shim 42 Washer 4 - 200 HV - ZNS3 43 ISA screw M4x25 - 8.8 - ZNT 44 Pen rotation elastomer 45 groove

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 2154586 [0004]

Claims (9)

Elastomer bearing, in particular engine mount for a motor vehicle, with at least one introduced between at least two support bodies spring / damper body, which is supported on at least one other support body in case of need, characterized in that the further support body, the spring / damper body adjustable in its extensibility can support. Elastomer bearing according to claim 1, characterized in that that the spring / damper body in one piece is, in particular consisting of a material, in particular from Rubber. Elastomer bearing according to claim 1 or 2, characterized that of a support body on the body side, whose other support body motor side with the Motor vehicle is connected and that the two support body essentially one side each, in particular opposite sides, of the spring / damper body in their elasticity influence, wherein the further support body at least another side of the spring / damper body in influenced by their elasticity. Elastomeric bearing according to one of the claims 1 to 3, characterized in that the spring / damper body essentially the shape of a cylinder or cuboid or Vielkants owns, its bases of the one and the other support body in their extensibility be influenced, the further support body the lateral surface or at least one side the lateral surface of the spring / damper body influenced in their elasticity. Elastomeric bearing according to one of the claims 1 to 4, characterized in that the further supporting body from at least two, in particular evenly, over the lateral surface, or over individual Sides of the lateral surface, of the spring / damper body distributed, substantially against the expansion direction of the spring / damper body, especially uniform, adjustable support body elements consists. Elastomeric bearing according to one of the claims 1 to 5, characterized in that the further supporting body from essentially in the radial direction against the lateral surface the spring / damper body adjustable support body elements consists. Elastomer bearing according to one of claims 1 to 6, characterized in that the supporting body elements as adjusting jaws ( 38 ), in particular six pieces, hinged at one end against the lateral surface of the spring / damper body, circumferentially around this, in a spring / damper body at least partially surrounding housing are mounted and at its other end by a respective ball head ( 37 ) are displaceable in the radial direction, by one of an adjusting wheel ( 31 ) by substantially 20 to 30 degrees of rotation back and forth adjustable adjusting ring ( 22 ), each ball head ( 37 ) in a substantially secant to the housing groove ( 45 ) of the adjusting ring ( 22 ) is guided. Elastomer bearing according to one of claims 1 to 7, characterized in that the adjusting wheel ( 31 ) by an actuator ( 3 ), in particular an electric motor, in particular with the interposition of a transmission gear, is driven. A method for varying the spring stiffness of an elastomer bearing, in particular an engine mount for motor vehicles, according to one of claims 1 to 8, characterized in that a control unit, depending on specific driving input variables, such as engine speed and / or vehicle speed and / or road condition or jounce - / Ausfederdaten the chassis, for example, the wheel acceleration, a necessary instantaneous value of the form factor for the support of the spring / damper element calculated by the support body elements of the other support body and this instantaneous value of the form factor on the spring / damper element by controlling, in particular energization, of the actuator ( 3 ), in particular with a control frequency of up to 300 1 / min.