HUE027965T2 - Érzékelõtartó és eljárás egy forgatónyomaték- vagy forgásszög-érzékelõ elrendezés rögzítésére - Google Patents

Description

SENSOR MOUNTING AN1> METHOD FOR FASTENING A TORQUE OR ROTATIONAL ANGLE

ARRANGEMENT

Description Prior an

The Ιανβκφη relaies to a method. for fastening a sensor mounting fo a shall for a totq»e or :rotafkmai-angle sensor arr&ogement, sa particular for the detection of rotational-angle·- or torque-dependent variables at the shall or between part-shafts.

It is known perse that sstch smmr mamimp, have to be fixedly fastened to the shaft m the· past-shafts to order to durably and reliably detect absolute or relative rotational movemmis of the shall or past-shafts together with electrical, magnetic, optical or other sensor means* which are foactkmafiv connected: to the mounting.

By way of example, it is known from I>£ I©2 40 Θ4Ρ At that a torooe sensor tor detecting: the torque present at a shah, in particular at steering shafts in a motor vehicle, is attached: to each of two mutually opposed part-shahs of the shaft. Here, a sleeve attached in a manner fixed against rotation and having magnets is provided on the first part-shaft and a magnetic field sensor of the sensor arrangement is attached to the other part-shaft, which is opposite the magnet on the first part-shaft, separated by a gap.

In this known: arrangement the magnetic flax generated In the gap is dependent on the rotational-angle position between the magnet and the detector of the sensor arrangement, a torsion dement being arranged between the part-shafts of the shaft, such that, herefrom, the lorgne acting ott the shaft can he measured.

Sunk a torque sensor additionally generally consists of two units, specifically ·« dynamic unit, which corotates with the steering shaft or the torsion, system:, and a stationary noil haying an electronics system:, which is: fixed to the surrounding gearbox casing. Mere, the dynamic an it is fastened in a manner distributed between the two part-shafts of the steering shaft, as described before, and may therefore also be di vided into a stator assembly and for example Into a magnetic assembly. The stator assembly consists at least of the srsfor bolder and tor example two sensors, wherein further component parts: can be integrated optionally into the stator assembly.

The mountings for tire stator assembly and for the magnetic assembly should fee festened here securely and fixedly on the steering shaft or the part-shafts over a predefined temperature range and over a determined service life. During assembly, the respective mounting Is pushed onto tbe respective part-shaft of the steering shaft end enters into a fixed mechanical connection: therewith. With such an arrangement if mast therefore be ensured independently of the sensor system that, for example, the mounting is: attached where possible in a form-fitting manner nod in a manner permanently fixed against rotation in order to avoid measurement errors.

Furthermore, a method of the type in question for fastening a sensor mounting for a torque sensor árrarsgeptent is knows from US 5,394,760 Á, in which case the sensor mounting is fastened to aa associated shall: fey means of sleeves mssde of plastie.

Umbsmo -of the invention

the invention proceeds frW)' a fastening: method; as disclosed in Claim L

Here, the shaft is advantageously pari, for example, of a torque sensor as -sensor arrang«m«ní, ín which two part-shafts are Interconnected via a torsion element The torque sensor arr&tigeineni consists» as is known par.se írom the prior art discussed is the Introduction, of a magnetic assembly on a first sleeve of the síOttítóng on the first part-shaft and of & stator assembly having the magnetic field sensors on. a second sleeve of the moaoting on the second part-shaft, such that: the torque front the relati ve rotation of the two pert-shafts, which are intereoaoeetod via a torsion bar,, can be. determined.

Etsch a torque sensor may advantageously preferably he attached to the steering shaft in a motor vehicle» the torque sensor being fastened to two axially mutually opposed part-shafts of the steering shaft and detecting & rotsîtional-arsgle change between the part-shafts.

The part-shafts, in the region of the attachment of the respective sleeves, preferably have a form-fit structure, which ihr example consists of a knurling siraclure in the axial direction of the shaft. On the other hand, axial or radial grooves or comparable suitable structures are possible, wherein a corresponding mating geometry can then be found in the sleeves. The molted plastic thus flows Into the structures of the lornwfiftmg geometry of tire part-shafts and subsequently cools down with the part-shafts, such that the form fit Is created between the part-shafts and the sleeves and is only slightly affected by signs of aging.

The sleeve may have a cylindrical, smooth inset diameter or, if directed joining: is desired, may have an Interrupted geometry. The inner diameter of each of the sleeves should fee smaller than the outer diameter of the part-shaft» in the region of the connection so that the force-fitting connection can be established between the two components following the passing process when the slee ves are pushed on»

In accordance with the method according to the mvenfksn tor fastening the previously described mounting, the part-shafts are generally made pi steel and are Ipcally heated up to a predetermined temperature, at least in the shaft portions or regions that serve for receiving the sleeve» of the motinling, which leads to the partial softening: of the plastic of the respective sleeve during the further «ourse of the process. The respective: sleeve Is then pushed on. In the axial direction sad, after a cooling down of the-respective shaft peftioo, the respective sleeve remains beaded with a fort» fit on the respective shaft portion.

The heating may fee performed for example by induction heating, fiamé heating or similar method», the temperature to fee selected being dependent on the used plastic material of the sleeves.

Here, it Is advantageous when the two shafts are pushed onto the regions of the part-shafts together with the magnetic assembly and the sodor assembly, respectively, In the subsequent working positions daring assembly'by »sing a .positional securing means and when fits positional securing tneaos is removed after the cool ing down of the part-shafts, The assembly of the entire torque sensor arrangement can thus be perforated at the same time, however .a time-delayed Individual assembly may also fee advantageous is different applications, Depending on the type of mounting, foe focal heating stay be performed ©sly on ok« of the t wo pm~$ha$$ or or both .

The proposed torgne season may thus be connected without play and permanently to the steering- shaft of a motor vehicle, the connection being achieved by a. eonfoined force fit and form fit. The plastic of tbc sleeves that is molted by thethermal energy of the part-shafts may be adapted in particular easily to the formatting geometry provided on the steering shaft, for example the knurling structure, and, with the-cooling down of the part-shafts, tbs respective sleeves may press onto the shaft, fous producing at foe same time a form It between foe sleeves and the shaft due to foe form-fitting geometry of foe shaft,

As the sleeves are pressed onto the heated part-shafts the plastic is thus softened and can fee stretched to a greater extent, streb: that a force-tMbg connection is created as wd! between the part-shafts and the inagnetk· assembly and the Stator assembly. The risk of a crack forming in the plastic of the sleeves under the -magnetic· sad the stator assemblies is foes prevented. Ah otherwise usually necessary reiafoteemetft of the sleeves, for example by Integrated metal sleeves, can thus he spared, whereby the costs css he reduced.

Brief deset ip>: ion of the drawing

Exemplary embodiments of foe invention will fee explained on the basis of foe flgares In the drawing, in which:

Figaro 1 show's an exemplary application of a mounting for a terepre sensor or· the steering shaft of a motor vehicle,

Figure 2 shows a detailed dinstration of foe magnetic and stator assemblies of the torque sensor according to Figure 1 before: foe part-shafts are posited onto the steering shaft, and

Figure 3 shows a detailed iiiustratkm of the detailed iilastration of the part-shafts of the steering shaft according to Figure 1 with a knurled form-fitting structure.

Ways of carry tag oat the invention

Figure 1 shows a device for determining a torque, exerted onto a shaft, at a steering shaft. 1 of a motor vehicle. Tb« sleeting abaft 1 here has two part-shafts 3 and 3, which arc interconnected fey means of a torsion bar 4. Here, a torque sensor arraogemeoï .3 is provided, which consists of a magnetic assembly 6' foot described here 5« gr estér detail) on the part-shaft 2 and a stator assembly ? on the part-shaft 3, with sr magnetic field sensor 8 for detecting the rofatfosal-angie-dependehf magnetic field changes.

The arrangement is surrounded by a Mat senary housing 11., wh ich is monnfod rotatably on the pact-shafts 2 and 3, The magnetic assembly 6 and the stator module 7 for detecting the relative rotational angle between the part-shafts 2 and 3 are held in a manner Sxed against rotation ©» foe path-shafts 2 and 3 by means of slee ves 9 and 10 as· parts of foe sensor meamsng.

Figure 2 shows a detailed Illustration of the magnetic assembly ft and of the stator assembly 7 of the torque, sensor arrangement 5 with the respective sleeves 9 and 19. Here, the two component parts ate