DE2314135A1 - DISC BRAKE - Google Patents

Description

Disc brake

The Brflndung relates to disc brakes "for cars _t in which a friction element is brought to a first braking member with the surface of a second Bremsglledes In Bingrlff, wherein one of the two brake members 1st one relative to the other brake member rotatable brake disc.

With a known disc brake, as is normally the case is installed in road vehicles, the second pulley member is an axially fixed, rotatable brake disc, and that Friction element is attached to an axially movable, non-rotatable member. In order to compensate for the axial braking load on the brake disc, a corresponding friction element can be used an opposite surface of the brake disc are pressed into engagement, so that the brake disc between the RdIb * elements is clamped. In a second known disc brake, such as those normally found in vehicles other than road vehicles is installed, the first brake member is an axially movable, rotatable brake disc, while the second brake member is an axially is a fixed, non-rotatable member.

The friction element usually consists of a block made of friction material that is chemically bonded to one another Includes asbestos fibers and attached to a metal backing plate at the first ^ enannntGU 3rem3enart or on the brake disc at the

309842/0620

ORIGINAL INSPECTED

second type of bromine is molded or riveted dead.

Have Relbelemente for brakes of the first mentioned type usually a small area!) ere I and a small extension in the circumferential direction, so that most of the brake disc remains uncovered for cooling, while the friction elements for the second type of brakes common rife ige are ring-shaped and Can be at least partially immersed in oil in order to obtain the To support heat dissipation.

It is important that the distance between the braking surface of the Relbeleraenta and the associated braking surface of the second braking member at a given clamping load or reaction force occurring braking torque during the entire service life of the Relbraaterlals must remain essentially constant so that the Rotation of the brake disc during the braking process to the opposite braking surfaces no different resistance is opposed ^ and that on the different wheels of the Vehicle no different braking occurs. The braking torque Is a function of the reaction, the distance from the axis of the rotating brake lever to which the reaction occurs acts, and the coefficient of friction between the braking surface of the Relbelements and the braking surface of the second braking member. The response itself is a function of that applied to the brake Pressure and the surface area of the refcbeleraents. Usually the reaction is seen as a punctual force, which acts in the pressure center of the friction element, and the radial distance of this pressure center point from the axis of the brake disc is called the effective radius of the Called friction elements.

It is known that the coefficient of friction of many friction materials in relation to the braking surface of the second Breni3 member changes after these friction materials have been subjected to one or more braking operations, and is also known Is it that, therefore, the friction moment is "scraped off", i.e.

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must be leveled by abrasion before the customer uses the vehicle. Such a proper "scraping" But not always possible, especially not with others than road vehicles that normally transport the customer in stone will.

The object of the invention is to create disc brakes whose relbel elements do not have the disadvantages mentioned exhibit.

According to the invention, in a disc brake of the type mentioned, the friction element comprises an Rslb material, the coefficient of friction of which undergoes a change in relation to the two-tone brake element when the friction element is leveled by abrasion or when it is scraped off. This friction element has a first friction surface which can be brought into engagement with the second braking member and wears out before engagement with the entire friction surface of the relay element is established. The first friction surface has a smaller surface area than the surface area of the entire friction surface and an effective radius which is larger than that of the entire friction surface _t when the coefficient of friction increases during the initial scraping, but smaller when the coefficient of friction decreases during the initial scraping.

The axial thickness of that region of the friction element which forms the first friction surface exceeds the thickness of the relative element after scraping by one in relation to the thickness of the Friction elements are small, and the volume of this area and its radial position can be chosen and arranged be that with a given reaction when tightening the 3remso it is ensured that the braking torque occurring during the scraping is essentially the same as the torque which occurs after the entire friction surface has been scraped off, i.e. when the coefficient of friction remains substantially constant. Since the surface area of the first friction surface is small, it is worn out relatively quickly, and it is completely

309842/0820

scraped off area of the Rs ibelar-or. t ^ -zu :: 7h-rid: \, h- ;, "-reh-re ^ d : 1 <the rest of the friction surface is still being scraped off,

The first. Friction surface Ivrin by dllu ^ i'iUte :: tol hau; :: α te: be formed for the friction element, where "htes IrL λ ε, 133 du. =: Te?.? Ibmaterial is from the Fribrr.äüerir.1 ^ Ur. l ^: .- = l ^> e: .5 ™ iut ^:.: rh-riChri.d> i "t or preferably that is gloicho.

The erate is preferably ixelbrl ^ ohe i ·:; ■ "■ · ü;: * ■■; ■ .- :. h Γ: .. '; de.i Friction element by corresponding.de Porcgeoii ^ g or d;, raw Ccar— surface treatment of the remaining helcfla ^ ha of the Ξ- ^ ΙΙ; elei ^ siita formed to the necessary extent.

Furthermore, the Reioelenent vcr ^ ,; gswGiss ώΐι: ^ 5 *: site Friction surface on which is not? Reseitlich abiiat ^ ": ·, v / hhrarid die first friction surface is leveled, alo al er ihr sr since.-3 rubbed off before an intervention πΙό äer g3sauten Eedhilache. manufactured will.

d / d di rii, e

The first friction surface and / or di can be arranged in such a way that their Fl'-. ' initial prc-r'ssi ■ ' :;.,: L

The area of the rubbing cavr-n, d · .- .. ■ · Ils 2 ', - re ^{;: ..:} ; - ~? L3.;. C :: li ^r -.:he forms, icann a lower;: . ::! ; Je X ^:. :: ·; ... 5; .ΐ; ΐ _} : € .- as :? 3er ^ ic which forms the first friction surface, ze d- ^ d - ^ i is J-Zoi :. , ·. ; - :; _t :. :: r dsr second friction surface occurs ",. ^; : -: T- :, l: ':. z ^; ..i ^: *" G t-dlfl ^ -ohe is abraded. Anderarsoit.:-: ::: -, rc &: ■■ :::; ... ■ ..:. Ζ :, - ■ :: Irir-ic: d ^ .-: Reibeleraents, who the svei; >'?,3ltI'lV d .- =; .. d. ::; ■ t, ·>■' ./,:-. ν ^ rίΐςίτΐ: '. ■: Have planks, where the Fl' --c '.: ^.:. "ir.er-" irh m: * Tr;:. ::.'..; -..- :;! ^ '", ^ iehe is comparably small iu V- ;: ¹ ;. ^ -: ..;: - ..; -7 -.-. ^ :. ¹¹ .-.". ";'-.- ■ -: ... ^ h del' first friction surface.

At one execution r / jels ^ isl d-. d-r: C; .... o, L ::;. "ί.1 :: ΐ ei.; e Disc brake one or more Srer / ^ sohciii'i s.ur_, the. "-. If a lielle rotatable and slidable ur: d; ^ it Hilf'-: airier Le-

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actuating device axially movable to form a stationary brake member are appropriate. Each brake disc carries a total annular friction element with an overall annular first friction surface, which is connected to the surface of the stationary Member can be brought into engagement and wears out before engagement with the entire friction surface of the friction element is established the effective radius of the first friction surface is greater than the effective radius of the entire friction surface.

The invention is explained below with advantageous details based on schematic drawings of several examples of execution explained in more detail. Show it:

1 shows a section through a teaching disk brake,

Pig. FIG. 2 is an end view of one of those used according to FIG. 1 Brake discs;

Pig. 3 an enlarged partial step through the In Pig. 2 Brake disc shown;

4 shows a partial section through a modified brake disk;

Fig. 5-3 Sections duih different friction elements for the disc brake shown in Figure 1;

9 is a perspective view of a further friction element.

In the case of the horizontal disc brake shown in FIGS. 1 to 3, two cooperating pressure plates 1, 2 are arranged between two rotatable brake discs 3, 4 within a stationary, cylindrical housing 5. The brake disks, which carry friction elements β on each surface, are mounted by means of pins 7 on a rotatable shaft (not shown). When the pressure plates are pushed apart, 'kick the brake disc · «! engaged by frictional engagement between the pressure plates and machined surfaces of the end wall 8 of the housing and a corresponding cover, not shown, attached to the open end of the housing, the end wall and the cover being the second

3098A2 / 0820

'· Ί "■ f'i" J ^r

Breras limbs forms ;.

Sine Botütl £ ma £! 3elr.ri.3-V.; I.: ... - ^r - ■ '-: -. ·' Ϋ "'- JFi? ⁴ ,

. ' ν- .: Λ ^! , ■■ τ. "■■■" ■ '-' jx au 'r. - c Ice ":: - "p" Zf .-. at

for an angular movement eier Dr ■:; ^ ■ "■;: ■: - ■;" .. '""■;.-; · - .. 'iagesetr; ΐ directions soi-rle balls 9 au /' ^. '^: ...:;: ..;:. ■: ■; ■ sη ^r ri "- ^:. ■; ramps 10 in the neighboring ·· Ooy.r ... ^, ^v; "e-."':.. ..: ·' Γ: Ίε. Tt; r: work and. The printing pla-cte; -; · λ ; .- \ ^ 1 '^ i-vr ---. "^„ :: .-. ll ::. r'.er; -u

sum triggering the ^T iinkelbe "eguß; .. :: .--. ■; 7 "; · -..-:, .- ■ ■ - ■" · t, - · r -.- ^ t hler ζ

not shown, si & kaan rber e,: ··; . ^ y ^. ^ ¹ / -:: .: ^ ^::; ': ~~ - \: - en ", the diverging ^{verbs ν} ; ά.ί; ^ -.:.;. cC cc ··: -'-." -: * ■ "::!" .: ~ is , ir: each other ends are hinged to laac ^ en .1 .rr · ·. ;;% £. To this Zv / ecir. :?; · ;,: a _;; ^; -other device verT, ^r en (let; rer .: ^r \, ;. ■: -. · '.. at an angle movable; ".' .., -l ^ _i ::; ■ ') ■ - : ei :: ^; ts:; r &iii; te 2ε-vregung in the original direction i / aazr: ..? - '; : ■ .l ·; ..;, j-iiiaiaet is allowed and squatting between kompj 3η3..Λ : ^ :. 'ί: ι ^ rr.di alen. -nnsützisn "n the printing plates works, lie euj: Ltr Zsiu ^ ¹ ..-!: ^ hsrvorgelit, the balls 9 are also in the V; iri" .: elaost, .u :. ";ν; · η lying axial grooves 11 in the inneroa "Lnifnugs.'l'iche of the housing arranged so that they are against e'uu ';" lr: .-: c: - ". bev; e _t ^c .; uLg are held, whereby the Viinkelbewer ^ ir.v; a ^ r aer y ^ aoäplatten be limited. In another.juioriiraug ^ iL &quot; the Hudeln completely between the pressure plates nngecrdaet _? '.uid lie? <"i α Ir The movement of one of the pressure plates is stopped by the 3irn, rlfi iine approach to the pressure plate with an AanchlPg a; n housing.

The middle Boreich 3ed ^; ~ Sri Hi ε disk 4 is on each side of an annular plate '■? stiffened, which are attached to the seldom of the brake disc , the anu, erv: ig on them. is attached. The Helbeleinente C .lici. ylnaförzl. ^ · and radially outwards at a distance of dea Verstel; '' ^ ngsplat ^; ; e ;: arranged uad • offset on the brake calipers ;? ! "plumb 13 ~ .n sawn holes 14 attached. The Frictioncn.eit is aA t vcr-u ^ ltnlsciüßig deep, angularly spaced fromeit.audyr Ί ia ^ ucioii radial hats ^ designed for cooling purposes, which also dio Koibfluche dec

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Divide frictional elements into a number of segments.

Each tear element has an annular first friction surface 16 on its outer circumference, a radially further inside, annular second friction surface 17 and a third friction surface 18 located furthest inward graded, like Pig. Figure 3 shows the areas of the element forming the three friction surfaces having a decreasing axial thickness to have. The step 19 between the first and second friction surface

is 0.13 mm (0.005 inches), for example, while the step 20 between the second and third friction surfaces is for example 1.3 mm (0.05 in).

When the brake is applied for the first time, only the first bromine surface engages the pressure plates and the housing, and it turns out that the braking torque comes into effect on an effective radius which is substantially greater than that effective radius of the friction element as a whole. The first rub? surfaces scrape off relatively quickly or level off quickly due to abrasion, and the full coefficient of friction between these friction surfaces and the stationary braking surfaces is available when these first friction surfaces are up to the level of the second friction surfaces have worn and during scrape off the second friction surfaces. The braking torque acts in a similar way after scraping or leveling the second friction surfaces by abrasion on a reduced effective radius until the second friction surfaces are up to the height of the third friction surfaces have worn, whereupon engagement with the entire friction surfaces of the friction elements occurs.

In the modified embodiment shown in FIG. 4 of the friction element, the second friction surface 17 is from four concentric areas 21 are formed which are triangular in section and the tips of which are at the same level as the first Friction surface 16 lie. These tips come into engagement with the stationary brake member when an engagement with the first friction

3098A2 / 0820

curse takes place, abor i'lve Mv; .... ;; \ .-. \. '' .y :.: ::. until the first friction surface 'λ ;; ^ -johll -tt ...:, 5 ", also opposite the first ::?> · νΐ c;?!' ■■ :] :: .-. v. ■ -L ;; for example C, 13 min (O.GCf ..: ■! - '■ -. :: ■'. :: L. f in both cases takes aar ^ lrtt; ν, ^ Τ '. "..- :: · ■; _ ■■ :; ": ν :; ^a Heibfluche pro ^ rassiv vo .:; ζ v ^. ^ ---. RV-i.:. '. ::. ■:': \ Llaxiraalvrert ^ u , irenn die äz_t ': ^ Rp i ..;: ". _;. ■;. :: =:": leveled au, rerden b ~:;. -rl ο'..:; Ό-j ν-2 .: ■.:.: -. J; .. ::.

Es l: atin eit: .o barking ^; ^ ΐ ^:.:. "·;.;^;: ¹ see, and the ers": s P.elb / M ^ oj ^; 1 .;' λ ^ 1 .. several concentrails 2; - vein :. be sve.: ..;:;,. · '. .. areas. 21 also spirclf. "R.cir αs ± h": i. ~ L ■ - ■ --- '': ^ e separated concentric G-obil-io; "^?;.:? ...: U

The second and third relbfl Processing after the original ^ lioi ^ n elements be formed .; but they k ^ -

to you ?.-.:. Whether he. "Cl ---- ei: e '

er? or:>

giving the friction

manufactured.

"R ¹ I rr

e Ib f

ang the first friction width i ^! ; S rsib-ileru

increasing axial thickness vc.o the outer circumference to the inner urii'ün ^
the rirksa takes the fricative element
gradually decreasing in the 1-IaIi, in the
increases. In? Ig. 6 is the radial
area on about a quarter of the r3
elevated. In Fig. 7 the ^ rtte He:.:; Il.l "'. Chs uu eia ^ eri.'ir-is Λ.ι mai3 compared to the iu5ea size ios H?: .. brileuents 7? Raick ~ _t ! Agit In Fig. 8 the * frictional result -7Ie in Ji-,: ^ bsestnii l3t,;.; Or s dai3 only a first friction surface '5 ur.α oine si'ei: ^? .-. · / -' ■ ^ flat 17 results, with the radial width of the first friction surface essentially corresponding to half of the radial Ir & lte dos Roibelements.

Flg. 9 shows a friction element 6 which, instead of 309842/0820

23H135

is stepped in the radial direction in the angular direction, the first friction surface 16 over the radial width of the friction element •enough. In this pail are the first friction surface and the second Friction surface 17 designed in the form of oppositely directed wedges, so that the area of the first friction surface decreases in the radial direction towards the axis of the friction element, whereby the effective radius is greater than the effective Hadlus' of the friction element as a whole.

For other execution games not shown here of the braking elements, the first friction surface can have a plurality of concentric annular surfaces that span the radial width of the Rialbelenients range, with the distance and the surface area of the Surfaces are arranged so that the effective radius entire first friction surface is greater than the effective radius of the entire friction element. The friction surface of the friction element can also be designed spherical, the first friction surface at the spherical point and on a larger effective radius lies as the effective radius of the whole Roibel element. In Similarly, the first friction surfaces, as shown in FIG. 9, need not be wedge-shaped, but rather it Any shape is possible that has a larger surface area radially outside the effective radius of the friction element has as the surface area radially inside this effective radius.

The above description is limited to embodiments in which the effective radius of the first friction surface is greater than the effective radius of the entire friction element, since with most friction materials the coefficient of friction increases during scraping. However, certain materials can also behave in opposite directions, and for these the embodiments described here would then be arranged in the opposite sense , ie that the effective radius of the first friction surface is smaller than the effective radius of the friction element as a whole.

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23H135

The obiga EoschieLbun ^ bgfa .. ^'11 : · si ^ h ζτκ, ν with an Ielirfac. disc brake, 3 ^e ^ °° h lctinnen oils Hsibele ^ duck _-; ογ ^ '* - 3 of the invention also readily to' / erwanäriir: In Tsirbelarjscheibec- brakes to be adapted for road runners.

^ 9 $ ί ^Λ · ' ■ *! - ^Λ

Claims (1)

A η s r: back Disc brake for a vehicle with a friction element on a first braking member with the surface of one to pass Brake member can be brought into engagement, one of the 3reasglieder is a brake disc rotatable in relation to the other brake member and the friction element comprises a friction material, whose coefficient of friction is in relation to the second braking member changes while the Roib element scrapes or through Levels abrasion, characterized in that the friction element (6) has a first friction surface (io) which can be brought into single engagement with the second brake member and wears out, before an engagement with the entire friction surface of the Roibelement is produced, the first friction surface a smaller one Area has as the area of the total friction surface and an effective radius which is greater than the effective radius of the entire friction surface if the coefficient of friction increases during scraping, but is smaller if the coefficient of friction drops when scraping. Disc brake according to claim 1, characterized draws that the effective radius, the area and the axial thickness of the first friction surface '(16) forming the area of the friction element (6) are chosen and arranged so that with a given reaction when the brake is applied, it is ensured that the braking torque developed during scraping corresponds essentially to the torque which after the scraping dor entire friction occurs. 3. Disc brake according to claim 1 or 2, characterized 3098A2 / 0S20 23U135 characterized in that the Reibelenent (6) a second friction surface (17), which is not used significantly, while the first friction surface (16) is abraded, and the is itself abraded before an engagement with the entire friction surface of the friction element takes place. 4. Disc brake according to .Anspruch 3, characterized in that the first friction surface (16) forming • The area of the friction element (6) remains essentially the same has axial thickness. 5. Disc brake according to claim 3, characterized in that the first friction surface (16) forming The area of the friction element (6) has a different thickness, so that the surface area of the first surface increases when it is scraped off. 6. Disc brake according to claim 4, characterized in that the friction element (6) is radially stepped (Pig. 3). 7. Disc brake according to claim 4, characterized in that the friction element (6) is stepped at an angle is, wherein a larger surface area of the first friction surface (16) compared to the effective radius of the entire friction surface of the Relbelement is radially offset (Fig. 9). 8. Disc brake according to one of claims 3 to 7, characterized in that the the second friction surface (17) forming the area of the friction element (6) has an essentially constant axial thickness. 9. Disc brake according to one of claims 3 to 71 characterized in that the the second friction surface (17) forming area of the friction element (6) has a different thickness, so that the Plächonbereich the second friction surface 309842/0820 23H135 increases when scraping. 10. Disc brake according to one of claims 1 blo 9, .due to this characterized in that the first friction surface (16) is made by surface treatment of the friction surface of the element (6). 11. Disc brake for a vehicle with one or more Brake disks that are rotatable and slidable on a shaft and are mounted axially movable by means of an actuating device to a stationary brake member and each of which has a carries a total of annular friction element, thereby g e Ic θ η η draws that the Reibeleraent (6) a total of annular comprises first friction surfaces (16) which are suitable for engagement with the surface of the stationary brake member (8) and wears out before a singular engagement with the entire friction surface of the friction element is established, the effective radius being the first friction surface is greater than the effective radius of the entire friction surface. 12. Disc brake for a vehicle with a brake disc attached to a rotatable wool at an axially fixed point and one on each side of the brake disc in a non-rotating one Brake member mounted friction element, which by an actuator with the brake disc axially in engagement is movable, characterized in that Iode's friction element (6) has a first friction surface (16), which is marked with * - the surface of the brake disc is engageable and wears out before a singular grip with the entire friction surface Friction elements is produced, the effective radius of the first friction surface is greater than the effective radius of the whole Friction surface. 13. Reibeleraent with a friction material, its coefficient of friction 3 changes during the scraping or leveling of the friction element by abrasion, for use in a 3098A2 / 0820 _ ₁₄ _ 23U135 Disc brake according to one of .Ansprüche 1 to 12, thereby characterized in that the Roibo element (6) has a first friction surface (16) which can be removed before a üin ^ riff is made with the entire friction surface of the friction element, and which has a smaller area than the area of the whole Friction surface and an effective radius that. greater is al3 the effective radius of the entire friction surface if the The coefficient of friction during scraping increases, but is smaller when the coefficient of friction during scraping decreases. 3098Λ2 / 0020 r side