Abstract:
The invention relates to a device for suspending a unit, especially a hydraulic unit of an electronically traction-controlled brake system of a motor vehicle. The unit is suspended in a receptacle provided on the vehicle such that vibrations are damped. Hydraulic units of vehicle brake systems are usually equipped with an electric motor for driving pumps located in the hydraulic unit. The brake pressure in the wheel brakes can be modulated via the pumps. The pump drive can cause mechanical and hydraulic vibrations in the unit which can result in unwanted operational noise in case the vibrations are transmitted to the vehicle body without being damped. The improved device is manually preloaded due to limited space for using tools. A clamping mechanism is guided in an axially movable manner on an armature which is fixed to the hydraulic unit and which can be moved from a basic position into a clamping position. The clamping mechanism is interlocked with the armature in both positions.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a 35 USC 371 application of PCT/EP 2006/066434 filed on Sep. 18, 2006. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is based on a device for vibration-damping suspension of a unit in a receptacle intended for it. 
     2. Description of the Prior Art 
     A device for vibration-damping suspension of a unit is already known, for instance from German Patent Disclosure DE 100 36 575 A1. This known device has a boltlike armature, secured to the unit, that protrudes in some portions past the outer dimensions of the unit. On this protruding portion of the armature, there is an elastomer part, with a middle portion of reduced outside diameter and with two end portions of greater outside diameter disposed on either side of the middle portion. The elastomer part rests with one of its end faces on the outer wail of the unit and cooperates, on the end diametrically opposed from that, with a rim of a bracing sleeve. A screw nut which is screwed onto a threaded portion on the outer end of the armature acts on the bracing sleeve. By tightening the screw nut, the elastomer part is axially prestressed, which brings about upsetting of the elastomer part in the axial direction in space and widening in the radial direction in space. Because of the deformation of the elastomer part, the middle portion presses on its circumference against the pairs of claws of the receptacle that embrace this middle portion. At the same time, the two end portions, with their faces toward the middle portion, are pressed laterally against the claws. The unit is thus supported indirectly in the receptacle via the elastomer part. Typically, for supporting the unit, a plurality of devices that are oriented in various directions in space is employed. 
     The goal of this kind of elastic suspension of a unit is to damp vibration transmission from the unit to the body of a motor vehicle. This vibration is engendered by an electric motor that is provided for actuating the pumps on the unit. The brake pressure at the wheel brakes can be modulated by the pumping mode. Without suitable damping of the attendant mechanical and hydraulic vibration, this vibration can be transmitted to the vehicle body and perceived as irritating by the occupants of the vehicle. 
     Tightening the aforementioned screw nuts of the devices disadvantageously requires a screwdriving tool. In the vehicle, however, there is as a rule only little free space available for using this screwdriving tool. Moreover, using the screwdriving tool makes the process of assembling the unit more difficult and time-consuming for the vehicle manufacturer. 
     SUMMARY AND ADVANTAGES OF THE INVENTION 
     By comparison, a device according to the invention has the advantage that it can be switched from its basic position to its clamping position by manual actuation, or in other words without the use of a tool. This makes the assembly process easier and shorter. According to the invention, for this purpose the device has a clamping element that is axially displaceable on the armature and that can be locked in both of its end positions to the armature. 
     Furthermore, the device may have an integrated actuation-securing means. This prevents actuation of the clamping means by mistake and at the same time provides security for the unit during shipping, because it absorbs impacts and thus prevents mechanical damage to the unit. This actuation-securing means is manually releasable. The release is effected, by means of a rotary motion of the clamping element relative to the armature. An especially advantageous feature embodies the clamping means as a bush provided with axial slits. As a result, the clamping means has spring properties, as a result of which, in both of its end positions, it can be reliably locked to the armature. Easy deformability of the elastomer part during its installation on the bracket is assured as long as the clamping means is in its basic position. At the same time, in its clamping position, the clamping means provides reinforcement of the elastomer part and thus assures its anchoring to the bracket under conditions that pertain in vehicle operation. Various options can be alternatively employed for anchoring the device of the invention. 
     Further advantages or advantageous refinements of the invention will become apparent from the ensuing description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows the device of the invention as a preassembled structural unit in the basic position in longitudinal section. 
         FIG. 2  shows a side view of the preassembled structural unit of  FIG. 1 . 
         FIG. 3 , in a three-dimensional view, shows a unit with an attached device according to the invention and a bracket in which the unit can be disposed with the aid of that device. 
         FIG. 4  shows a detail D of  FIG. 3  in longitudinal section, here showing the device of the invention in its clamping position. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The device  10  shown in  FIG. 1  comprises an armature  12 , an elastomer part  14  supported by the armature, and a clamping means  16  that in some portions plunges into the interior of this elastomer part  14 . The clamping means  16  is guided axially displaceably on the armature  12  and can be switched from its basic position to a clamping position by manual actuation. 
     The armature  12  is a cylindrical metal part, preferably made from solid material, with a multiply-stepped external contour. The longitudinal axis of this armature  12  and hence of the entire device  10  is marked B in  FIG. 1 . A first armature portion  12   a  of reduced outside diameter serves to secure the armature in a receiving bore of a unit not shown in  FIG. 1 . This first portion  12   a  can be embodied for this purpose with a smooth or knurled surface on its circumference, if it is intended that the armature  12  be anchored in a receiving bore by press-fitting. Alternatively, this armature portion  12   a  could instead be provided with a male thread, if it should be intended that the connection of the armature  12  to the unit be made in the form of a screw connection. The first armature portion  12   a  merges at a rectangular shoulder  12   b  with a second armature portion  12   c  of greater outside diameter. At a short axial spacing from the shoulder  12   b , this second armature portion  12   c  has a hollow-throatlike annular groove  12   d , which is engaged by an extension  14   a  of complementary shape on the inner contour of the sleevelike elastomer part  14 . The annular groove  12   d  and the extension  14   a  thus form a positive engagement  13  between the elastomer part  14  and the armature  12 . The second armature portion  12   c  ends in a protrusion  12   e  whose outside diameter is increased still further and which has an essentially rectangular cross section. This protrusion  12   e  is adjoined by a third armature portion  12   f . This third armature portion  12   f  is embodied in the form of a rib, which extends transversely to the longitudinal axis B in a plane extending perpendicular to the plane of the drawing. The rib shape is due to the provision of two diametrically opposed flat faces  12   g  on the external contour of the armature  12 . In the case of a device  10  screwed to a unit, these flat faces  12   g  may form wrench engagement faces for introducing a tightening torque on the armature  12 . 
     On the armature  12 , as already noted, an elastomer part  14  is retained by positive engagement  13 . The elastomer part  14  is in sleeve form. It has a middle portion  14   b  that is recessed in its outside diameter and that is adjoined by both sides by end portions  14   c  and  d  of greater outside diameters. The first end portion  14   c , toward the first armature portion  12   a , is flush with the rectangular shoulder  12   b  of the armature  12  and has a greater axial length than the second end portion  14   d . Both end portions  14   c, d  preferably have the same outside diameter. The inside contour of the elastomer part  14  is formed by the extension  14   a , which engages the annular groove  12   d  in the armature  12  and is embodied in the region of the first end portion  14   c  of the elastomer part  14 . At a conically embodied widened diameter  14   e , this extension  14   a  merges with an inner wall of a blind-borelike chamber  18 , which is enclosed between the elastomer part  14 , the armature  12 , and the clamping means  16 . Its opening  14   f  closed by the clamping means  16  is provided with an outlet chamfer  14   h  extending all the way around. Viewed in the direction of the longitudinal axis B, the chamber  18  extends to beyond the middle portion  14   b  into the interior of the elastomer part  14 , or in other words into the region below the first end portion  14   c.    
     The clamping means  16  in  FIG. 1  is in its basic position. It is likewise designed in sleevelike form and has a cylindrical collar  16   a , which surrounds the armature  12  and guides the clamping means  16  axially displaceably on the armature  12 . The collar  16   a  changes over, at the end of the clamping means  16  facing away from the elastomer part  14 , to a radially encompassing rim  16   b , forming an outer cone  15 . The outside diameter of this rim is adapted to the outside diameter of the elastomer part  14  in such a way that the rim  16   b  substantially covers the end face of the elastomer part  14 . The clamping means  16 , in its interior along the longitudinal axis B, has two spaced-apart annular grooves  16   c  and  16   d . These annular grooves  16   c, d  have rectangular front flanks. The back flank of the first annular groove  16   c , which groove is oriented toward the elastomer part  14 , extends in beveled fashion toward the armature  12 . In the basic position shown, this first annular groove  16   c  is engaged by the protrusion  12   e  of the armature  12 . As a result, the clamping means  16  is locked in captive fashion to the armature  12 . 
     In  FIG. 1 , the collar  16   a  of the clamping means  16  extends into the elastomer part  14  only as far as the beginning of the middle portion  14   b . The chamber  18  extending below the middle portion allows a deformation of the elastomer part  14  in this region with relatively slight force. As a result, the device  10  described can be introduced into a receptacle ( FIG. 3 ,  32   a, b, c ) that surrounds the middle portion  14   b.    
     In the basic position shown, the clamping means  16  protrudes past the armature portion  12   f  that is provided with the two flattened faces  12   g . Between the rim  16   b  and the elastomer part  14 , there is an axial spacing A. In the region of its rim  16   b , the clamping means  16  has an internal contour  16   h  that is especially shaped. This contour is adapted in its shape and dimensions to the riblike external contour, resulting because of the flattened faces  12   g , of the armature portion  12   f . For switching the clamping means  16  from the basic position shown to the clamping position, the clamping means  16  must first be oriented relative to the armature  12  by a rotary motion that can likewise be performed manually. In the oriented position, the armature portion  12   f  can plunge into the internal contour  16   h  of the clamping means  16 . In the non-oriented state, this is not possible, since the clamping means  16 , with its wall surrounding the internal contour  16   h , abuts against an end face  12   h  of the armature  12 . The clamping means  16  is thus blocked against axial displacement on the bolt  12 . In other words, the internal contour  16   h  of the clamping means  16  cooperates with the flattened faces  12   g  of the armature  12 , acting as a manually releasable actuation-securing means  17  ( FIG. 2 ) which is integrated with the device  10  and prevents unintended actuation of the clamping means  16 . In addition, the actuation-securing means  17  acts as protection in shipping for a unit equipped with such a device, by protecting this unit against damage from impacts. 
     In  FIG. 2 , the clamping means  16  is provided with continuous, intersecting longitudinal cuts  20   a - d . These longitudinal slits  20   a - d  extend from the rim  16   b  in the direction of the longitudinal axis B as far as the first annular groove  16   c  oriented toward the elastomer part  14 . They divide the clamping means  16  into four spring-elastic segments, and the diametrically opposed segments are symmetrical to one another in their dimensions. As a result, especially in the region of the rim  16   b , the clamping means  16  has spring-elastic properties. In conjunction with the beveled back flank of the annular groove  16   c , these properties enable radial widening of the clamping means  16 , by subjection of the clamping means  16  to an axial force, and consequently make it possible for the existing locking to the armature  12  to be overcome. Under the influence of the axial force, the clamping means can then be manually displaced along the longitudinal axis B of the armature  12  into its clamping position. The clamping position is reached as soon as the protrusion  12   e  has snapped into the second annular groove  16   d , remote from the elastomer part  14 , of the clamping means  16 . 
     The spring-elastic segments together define the aforementioned internal contour  16   h . This contour has an essentially rectangular shape, with outward-curved short sides diametrically opposite one another. The clamping means  16  in  FIG. 2  is in the non-oriented position relative to the armature portion  12   f . As a result, through the internal contour  16   h , the two flattened faces  12   g  located beneath it in the armature portion  12   f  can be seen in some portions. The further course of the external contour of the armature portion  12   f  concealed by the clamping means  16  and is therefore represented in  FIG. 2  by dashed lines. By a rotary motion of the clamping means  16  about a rotary angle α of preferably 90°, the described actuation-securing means  17  can be manually released. Once the clamping means  16  has been oriented relative to the external contour of the armature portion  12   f , the clamping means  16  can be displaced manually in the direction of the longitudinal axis B out of its basic position to its clamping position. 
       FIG. 2  finally also shows that the circumferential surface of the rim  16   b  may be provided with surface profiling  19 , for instance, in order to facilitate the aforementioned manual actuation of the clamping means  16 . 
       FIG. 3  shows a unit  22  onto which a device  10  of the invention is mounted. This unit  22  comprises a block-shaped unit housing  24 , machined in metal-cutting fashion, with an electric motor  26  secured to it and with an electronic control unit  28  secured on the side diametrically opposite the electric motor  26 . Units of this kind are well known in their construction from slip-controlled vehicle brake systems and therefore need not be described in detail. They serve to modulate the brake pressure in wheel brakes connected to them, taking into account the braking intention of the driver and the slip conditions at the wheels of the vehicle. The wheel brakes are connected to the unit  22  via brake lines (not shown in  FIG. 3 ). 
     Such units  22  are typically anchored to the body of a vehicle with the aid of a bracket  30 . The bracket  30  shown for this purpose has a first, horizontally oriented leg  30   a  and a second leg  30   b  extending perpendicular to the first. Both legs  30   a, b  are bent at right angles, and two receptacles  32   a, b  oriented in a first direction in space are embodied at the bend of the horizontal first leg  30   a . The second leg  30   b  forms a third receptacle  32   c , oriented in a second direction in space. The receptacles  32   a, b, c  are shell-shaped rounded areas, open toward an assembly direction (represented by the directional arrow M), with pairs  34   a, b  of claws disposed laterally of them and constricting the opening. Three devices  10 ,  11   a ,  11   b  are secured to the unit  22  and in the assembled state of the unit  22  rest in the respective associated receptacles  32   a, b, c.    
     In the exemplary embodiment of  FIG. 3 , only the device  10  (detail D) is embodied according to the invention; in  FIG. 3 , it is anchored on the right-hand outer side of the metal block  24 . Of the other two devices  11   a ,  11   b , only the device  11   a  can be seen in detail. It has a screw nut  36 , by way of which all elastomer part  14  can be mechanically prestressed via a sleeve element  38 . 
       FIG. 4 , finally, shows detail D of  FIG. 3 , enlarged and in longitudinal section. The device  10  is press-fitted with its armature  12 , via the first cylindrical armature portion  12   a , into a receiving bore  40  in the unit housing  24 . In this press-fitted state, the shoulder  12   b  of the armature  12  is braced on the outside of this unit housing  24 . At the same time, the first end portion  14   a  of the elastomer part  14  rests on the unit housing  24 . The pair of claws of the bracket  30  embraces the middle portion  14   b  of the elastomer body  14  of the device  10 ; because of the course of the section in  FIG. 4 , only the rear claw  34   b  of this pair of claws can be seen. 
     In  FIG. 4 , the clamping means  16  is in its clamping position. In it, there is a detent connection between the annular groove  16   d , facing away from the elastomer body  14 , and the protrusion  12   e  of the armature  12 . The rim  16   b  of the clamping means  16  presses axially, with its inside oriented toward the unit housing  24 , against the end face, remote from the unit housing  24 , of the elastomer part  14 . The outer cone  15  at the transition point from the collar  16   a  to the rim  16   b  of the clamping means  16  acts on the outlet chamfer  14   h  at the opening  14   f  of the elastomer part  14  and as a result widens this elastomer part  14 . In the clamping position shown, the middle portion  14   b  of the elastomer part  14  thus presses against the inner face of the claw  34   b . Moreover, the two end portions  14   c, d  of the elastomer body  14  are pressed, with their faces oriented toward the middle portion  14   b , laterally against the claw  34   b.    
     The collar  16   a  of the clamping means  16 , in this clamping position, extends axially to beyond the middle portion  14   b  of the elastomer part  14 , so that the chamber  18  between the armature  12  and the elastomer part  14  occupies a minimal volume. As a consequence, the elastomer part  14  now has only a slight residual elasticity, which is sufficient for effective damping of any transmission of mechanical or hydraulic vibration that may occur from the unit  22  to the vehicle body via the bracket  30 . 
     It is understood that changes or additions to the exemplary embodiment described may be made without departing from the fundamental concept of the invention.