WO2008028901A1

WO2008028901A1 - Damping sheet for a disk brake

Info

Publication number: WO2008028901A1
Application number: PCT/EP2007/059222
Authority: WO
Inventors: Ralf Flemming
Original assignee: Hühoco Metalloberflächenveredelung Gmbh
Priority date: 2006-09-06
Filing date: 2007-09-04
Publication date: 2008-03-13
Also published as: DE202006013606U1

Abstract

The invention relates to a damping sheet (1) for a disk brake (DB), comprising a carrier (2) to which a coating (3, 4) made of elastomer is applied on at least one side. In order to achieve effective vibration and noise damping with a simple design for this damping sheet (1) and also to achieve that the inventive damping sheet can be adapted, particularly also in a flexible manner, to different stresses or loads of the disk brake (DB), it is proposed to configure the carrier (2) as a stamped part, to which the elastomer coating (3, 4) is applied by injection molding.

Description

"Damping plate for a disc brake"

The present invention relates to a damping plate for a disc brake, with a carrier, on which at least on one side of a coating consisting of an elastomer is applied.

Damping plates for disc brakes are known. For example, DE 199 12 957 A1 describes the function and the basic structure of such damping plates. A damping plate prevents the direct metallic contact between the brake piston of a disc brake and the support plate of the disc brake pad and causes a decoupling of the vibrations occurring during the braking process. For this purpose, it usually has an at least three-layered structure: the actual sheet, so the carrier, an adhesive layer on the underside of the carrier, which is used to attach the damping plate on the support plate of the disc brake pad, and a rubber, plastic or paint layer the top of the sheet, which forms the damping layer between the brake piston and the brake pad carrier and in particular within the damping layer, a pressure receiving area for the forces to be transmitted of the brake piston. Specifically, DE 199 12 957 A1 provides a free cut which reduces the thickness of the damping plate and which at least partially lies outside the pressure receiving area and weakens the force flow in the direction of an associated edge of the damping plate that tends to buckle.

Also in DE 696 12 183 T2 is a generic damping plate for a disc brake - there referred to as an intermediate layer for preventing brake squeal - described. The damping liner serves to reduce high frequency noise generated during braking. It is stated that damping plates are known to be made using a rubber-coated Metal can be prepared by on both surfaces of a thin metal plate made of iron (cold pressed steel plate), stainless steel, copper, etc. as a starting material, thin rubber layers are formed, which form an interlayer structure in which a pressure-sensitive adhesive layer on the surface of a the rubber layers in the starting material is arranged. This adhesive coating is then in turn adhered to a backing or support plate of a disc brake pad consisting of this backplate and a friction material on the surface thereof. DE 696 12 183 T2 then describes in detail damping plates, in which the rubber coating on the metal support plate is provided only on one side. Both primer layers can be arranged between the metallic support plate and the pressure-sensitive adhesive layer, as well as between the metal plate and the rubber layer.

Furthermore, from DE 692 13 255 T2 a vibration and sound absorbing spacer for vehicle brakes is known, which consists of two thin metal plates and a vulcanized elastomeric damping layer enclosed therebetween. From the description of the associated method for producing a web for the production of such spacers or inserts it becomes clear how well known so far the rubber layers are applied to the support of the damping plates and of which material they consist. In particular, in order to produce an adhesive bond between a damping layer and a metallic support plate, which is not destroyed at high pressure and high temperature, but also an effective vibration and sound attenuation should be ensured, the damping layer according to DE 692 13 255 T2 becomes thinner than each of the metal plates executed. It consists of a rubber layer, which has a structure of an arc, which is formed by calendering and then applied to the two metal plates and vulcanized there. The material of the rubber layer is preferably a nitrile rubber (NBR).

Calendering or calendering (French: "calandre") is a manufacturing process in which the application of the elastomeric layer is carried out by splitting in a system of several superimposed heated and polished rollers made of die-cast or steel. The process is usually used for the production of films made of plastics (PVC, PE, PS, etc.), rubber and metals. For plastics, calendering usually produces comparatively thick films, while rubber films or layers range from 0.03 to 0.80 mm getting produced. A similar, also known for damping plates applied method is the roll coating (English: "Roll coating"), in which also a roll application of the elastomeric layer takes place, which, however, immediately, not after a previous film formation, is applied to the carrier.

Damping plates, in which the application of an elastomeric layer by means of calendering or roll coating process, can - if necessary - only subsequently deformed, for example, bent, or stamped, wherein the punching the contours of the damping plate and therein be provided recesses, such as free cuts can be generated.

The present invention is based on the object to provide a damping plate of the type mentioned above, which is characterized by a simplified production method by an effective vibration and sound attenuation. Furthermore, the damping plate according to the invention should in particular also be flexibly adaptable to different loads or load cases of the disc brake by the pressure cylinder.

This object is achieved for a damping plate of the type mentioned above in that the carrier is a stamped part, on which the elastomeric coating is applied by means of injection molding.

Injection molding is a primary molding process that makes it possible to manufacture industrially directly usable molded parts in large numbers and with high accuracy. For this purpose, the respective material or molding compound is plasticized in an injection unit of an injection molding machine and injected into an injection molding tool. In contrast to calendering, with which usually only even layers of uniform thickness are produced, the cavity of the tool, the so-called cavity, determines the shape and the surface structure of the finished part.

Since the cavity can be adapted to the shape of the carrier of a damping plate according to the invention, stamped and bent parts as carriers - for example as metal carriers, which consist in particular of a cold strip, such as EN 10139 or EN 10130, can advantageously also be less complex in terms of production engineering Be made way. The shape of the surface of the damping plate according to the invention can advantageously be selected almost freely. It can - as an integral Surfaces or in a sectoral combination with each other - easily smooth surfaces, graining and patterns, etc. are produced. In particular, it is possible to vary the thickness of the elastomeric coating over the surface of the carrier. It is particularly preferred that the coating on the surface of the damping plate more or less punctiform or linear or planar, for example circumferential, profiles are formed, which can intersect and / or to set an optimal area or line pressure can be wider or narrower with the brake cylinder and its damping characteristic over its path and vary in height. The profiles can advantageously also take over functions as sealing elements, as well as additional fixing and / or as positioning aids.

Further advantageous embodiments of the invention are contained in the subclaims and the following specific description. On the basis of embodiments shown in the accompanying drawings, the invention will be explained in more detail. Show

1 in section, a first embodiment of a damping plate according to the invention in the application,

Fig. 2 in plan view, a second embodiment of an inventive

Damping plate,

3, a section along the line A-A in Fig. 2,

FIG. 4 enlarges, a section along the line B-B in FIG. 2, FIG.

FIG. 5 enlarges, a section along the line C-C in Fig. 2nd

In the various figures of the drawing, the same parts are always provided with the same reference numerals and are therefore generally described only once in each case.

As initially apparent from Fig. 1, which shows an inventive damping plate 1 in the assembled state in a disc brake DB, the damping plate 1 is composed of several layers 2, 3, 4, 5. The damping plate 1 is used special for preventing the generation of high-frequency noise when braking with the disc brake DB of a motor vehicle. It is manufactured using a carrier 2, which is provided on at least one side - in the case shown on both sides - with a coating consisting of an elastomer 3, 4.

FIG. 1 further shows that an adhesive layer 5, such as an adhesive layer or film, in particular provided with a pressure-sensitive adhesive, is applied to the elastomeric coating 4 arranged on the underside, by means of which adhesive bonding of the damping plate 1 to the carrier plate 6 of a disc brake pad 7 can take place , which in turn carries on the side facing away from the adhesive layer 5 side of the support plate 6, the friction material 8. In the case of one-sided elastomeric coating (3 or 4) of the carrier 2, the adhesive layer 5 can be applied to one of the coatings 4 on the non-coated side of the carrier 2 and on the coating 2, 3 of the carrier 2 on both sides. By the reference numeral 9, an element of a brake piston is referred to, which serves to generate braking forces F, which are introduced via the damping plate 1 according to the invention in the brake pad 7 of the disc brake DB.

The carrier 2 of the damping plate 1 according to the invention is a stamped part or a stamped and bent part and may in particular consist of metal, preferably of a cold strip, such as EN 10139 or EN 10130, and a thickness T in the range of about 0.2 to 1, 0 mm, preferably from 0.3 to 0.5 mm.

The elastomeric coating 3, 4 of the damping plate 1 according to the invention is applied by means of injection molding. It is an elastomer injection molding, which can be done on a Schneckenensztzgießmaschine. The elastomer for forming the coating 3, 4 can be z. B. in the form of a free-flowing powder or as a band of a special screw, which introduces only a small amount of shear in the plasticized or plasticized mass introduced.

In order to avoid overheating, while the cylinder of the Schneckenensptzgießmaschine is tempered with a liquid, the processing temperature is conveniently about 70 ⁰ C to prevent vulcanization in the cylinder. The screw kneads and mixes the molding material, which is thus processed homogeneously. During the subsequent inflow, frictional heat is generated in the nozzles and sprue channels. As a result, the duration of the subsequent volcanic sation, whereby the efficiency of the injection molding process is increased, since usually the vulcanization time in elastomer injection molding is significantly greater than the treatment time in the injection unit and therefore represents the limiting process step.

The fundamental difference between the processing of elastomers and thermoplastics on injection molding machines is the temperature distribution in the machine. For thermoplastics, the screw is relatively hot to melt the thermoplastic material. The tool, however, is relatively cold to cool the just formed molding. For elastomers, the screw is relatively cold, but the tool is hotter (about 130 to 250 ⁰ C) to allow vulcanization. In particular, so-called cold runner systems can be used in front of the tool, whose nozzles and distributors are tempered to 60 to 120 ^° C. in order to prevent the plastic molding compound from solidifying prematurely. The advantage of using such systems is, above all, that when removing the casting from the mold no so-called gate spider, ie solidified in the sprue channels mass parts, must be removed.

In particular, according to the invention for applying the elastomeric coating 3, 4 on the support 2 of the damping plate 1, the so-called in-MoId method is used. The in-mold process is an injection molding process in which the substrate inserted into the injection molding tool, that is to say according to the invention, the support 2, which, as already mentioned, can advantageously be structured in any desired manner, is injected or back-injected. In this way, in one step, a composite body, so the damping plate 1 according to the invention, which can be awarded by means of the method, a variable in a wide range surface design.

In this case, first of all an adhesive substance, a so-called adhesion promoter, can be applied to each of the surfaces of the carrier 2 to be coated, to which then the liquid elastomer layer is applied. The elastomer-covered carrier 2 is then arranged in the heated form such that any elastomeric layer whose thickness varies with the desired surface finish of the coating 3, 4 is shaped. Finally, the elastomer is vulcanized hot. The coating 3, 4 thus advantageously consists of a single material produced by the above operations in a single tool.

Instead of or in addition to the application of the adhesive substance, the surface of the carrier 2 can, if necessary, be pretreated in another way, for example by blasting or etching.

In addition, it is also possible in a particularly advantageous manufacturing technology that the production of the carrier 2 as a stamped or stamped-bent part takes place in the same tool as the subsequent injection molding, by which the coating 3, 4 is formed. The stamp engaging in the tool mold for punching and optionally bending is at the same time the carrier for the injection nozzles of the liquid elastomer composition and according to the form of the coating 3, 4 kontuhert.

When applying the elastomeric coating 3, 4 may optionally be provided that the coating 3, 4 either on the support 2 existing edges and narrow sides (in Figs. 1 and 5 denoted by the reference numeral 2a) covered or even free, as the latter is known exclusively and necessarily in case of roll coating followed by punching. The free-floating or the covering of the narrow sides 2a can be achieved according to the invention by the design of the cavity of the injection mold, wherein the narrow sides 2a of the carrier 2 are placed in the cavity such that the narrow sides directly on the wall or at a designated distance away from the wall the cavity come to rest. An uncoated narrow side 2a of a damping plate 1 according to the invention therefore does not have any cutting edge in the elastomeric coating 3, 4, but instead shows a specific edge-type structure produced by the injection molding.

The elastomer of the coating 3, 4 may preferably be a rubber having siloxane groups in the polymer chain, such as a silicone rubber or a fluorosilicone rubber. For a silicone rubber, such as a polydimethylsiloxane (MQ), methyl vinyl silicone rubber (MVQ), or methyl phenyl silicone rubber (MPQ) or methyl phenyl vinyl silicone rubber ( MPVQ) may advantageously combine good injection-moldability with high availability and low price, while a fluoro-silicone rubber such as methyl-fluoro-silicone rubber Rubber (MFQ), in particular a high temperature stability, preferably in the range of up to 150 to 160 ⁰ C having.

In the case of methyl vinyl silicone rubber (MVQ), in particular to improve the vulcanization behavior and the tear propagation resistance by addition of vinyl methyldichlorosilane to the reaction mixture, small amounts, ie. h quantities less than 1% by mass.

For methyl phenyl silicone rubber (MPQ), the introduction of phenylmethyl siloxane groups in amounts of up to about 8 percent results in elastomers with improved cold flexibility and heat resistance.

For fluoro-silicone rubber, a so-called equilibration, i. H. a control of the chain length or molar mass by the reaction conditions, such as by the creation of a strongly acidic or alkaline Reaktionsmilieus, increased chemical, solvent and fuel resistance are brought about. Under the conditions mentioned, it is the case that the otherwise very stable siloxane bonds of oligo- and polysiloxanes are continuously split and recombined until a polymer distribution corresponding to the thermodynamic equilibrium is reached. Thus, for the preparation of trifluoropropyl silicone rubber (FVMQ), in particular 3.3.3-thfluoropropyl groups can be incorporated into the elastomer molecule by equimers of appropriately substituted oligosiloxamines.

Furthermore, the application method for the coatings 3, 4 provided according to the invention combines the advantage that a thickness D of the elastomeric coating 3, 4 can vary over the surface of the carrier 2.

Moreover, as illustrated in FIGS. 2 to 5, it is possible for surface structures to be formed by the coating 3, 4. Thus, the graphic representation shows more or less point-like surface structures 10, line-shaped structures 11, sheet-like structures 12, 13 as the illustrated annular structures 13 through which - as the illustrations in Fig. 3 to 5 show - profiles are formed.

As already mentioned, these surface structures 10, 11, 12, 13 can intersect and / or for setting an optimal area or line pressure with the Brake cylinder 9 and its damping characteristic with respect to the suppression of the squeal of the disc brake DB on its path S in their respective widths B10, B11, B12, B13 increase or decrease and vary in their height H10, H11, H12, H13. The maximum height H10, H11, H12, H13 represents the thickness of the coating 3, 4 in the structured areas. The same applies to the cross-sectional shape of the surface structures 10, 11, 12, 13, which - as shown - for example, a triangle -, square or semicircular shape can be. Likewise, the surfaces of the structures 10, 11, 12, 13, which are assigned in FIG. 2 with reference numerals A10, A11, A12, A13 in brackets to the respective structures 10, 11, 12, 13, may be of different sizes.

The thickness D, H10, H11, H12, H13 of the elastomeric coating 3, 4 may advantageously be in the range from about 20 to 5000 μm, preferably in the range from 20 to 200 μm, in particular the thickness D in the non-structured surface regions. lie.

The surface structures 10, 11, 12 can advantageously take over functions as sealing elements, such as molded sealing lips, as well as additional fixing and / or positioning aids-in particular in edge regions of the damping sheet 1 according to the invention. Like the coating 3, 4, the surface structures 10, 11, 12 can be arranged on one or both sides.

The invention is not limited to the above embodiments. For example, it is also possible for the support 2 to have apertures, such as holes, recesses or cutouts, or for the support 2 to have embossed areas, in particular in the area of the surface structures 10, 11, 12, without leaving the scope of the invention. The breakthroughs and / or embossed areas of the carrier 2 can be wholly or partially covered or filled with the coating 3, 4.

In addition to the preferred elastomer materials mentioned above, it is also possible in principle to use other moldable materials, such as acrylate copolymer rubber (ACM), acrylonitrile butadiene rubber (NBR or HNBR), fluorine-containing rubber (FKM) or similar materials. In addition to the processing properties, the selection criteria used are the achievable Shore hardness and the viscoelastic properties that make up the required properties. derliche vibration damping effect of the damping plate 1 according to the invention results.

Furthermore, the invention is not limited to the feature combination defined in claim 1, but may also be defined by any other combination of certain features of all individually disclosed features. This means that in principle virtually every individual feature of the claim can be omitted or replaced by at least one individual feature disclosed elsewhere in the application. In this respect, the claims are to be understood merely as a first formulation attempt for an invention.

reference numeral

1 damping plate (from DB)

2 carriers of 1

2a narrow side of 2

3 coating on 2, upper side in Fig. 1st

4 coating on 2, underside in Fig. 1

5 adhesive layer

6 support plate of 7

7 brake pad (from DB)

8 friction lining from 7 to 6

9 brake cylinders (from DB)

10 point-like surface structure of 3, 4

11 linear surface structure of 3, 4

12 surface-shaped surface structure of 3, 4

13 annular surface-shaped surface structure of 3, 4

A10 area of 10

A11 area of 11

A12 area of 12

A13 area of 13

B10 width of 10

B11 width of 11

B12 width of 12

B13 width of 13

D Thickness of 3 (4) - non-profiled area

DB disc brake

F braking forces of 9 H10 height of 10, thickness of 3 (4)

H11 height of 11, thickness of 3 (4)

H12 height of 12, thickness of 3 (4)

H13 height of 13, thickness of 3 (4)

S course of 10, 11, 12

T strength of 2

Claims

claims

1. damping plate (1) for a disc brake (DB), with a support (2) on which at least on one side of a coating consisting of an elastomer (3, 4) is applied, characterized in that the carrier (2) a Punching part is, on which the elastomeric coating (3, 4) is applied by injection molding.

2. damping plate (1) according to claim 1, characterized in that the carrier (2) is a stamped and bent part.

3. Damping sheet (1) according to claim 1 or 2, characterized in that the carrier (2) consists of metal, in particular of a cold strip, such as EN 10139 or EN 10130 exists.

4. damping plate (1) according to one of claims 1 to 3, characterized in that the carrier (2) has openings, such as holes, recesses or free cuts.

5. damping plate (1) according to one of claims 1 to 4, dad u rch ge ken nzeich n et that the carrier (2) has embossed areas.

6. damping plate (1) according to one of claims 1 to 5, characterized in that the carrier (2) has a thickness (T) in the range of about 0.2 to 1, 0 mm, preferably from 0.3 to 0.5 mm, has.

7. Damping sheet (1) according to one of claims 1 to 6, characterized in that the coating consisting of an elastomer (3, 4) on both sides of, in particular band-shaped carrier (2) is applied.

8. damping plate (1) according to one of claims 1 to 7, dadu rc hge ke nnzeichnet that the consisting of an elastomer coating (3, 4) in an in-mold process, in particular in a cold runner system, on the support (2 ) is applied, preferably in a tool in which also the carrier (2) is punched.

9. damping sheet (1) according to one of claims 1 to 8, dadu rch GE nzeich nzeichn et that that in one-sided elastomeric coating (3, 4) of the carrier (2) on the uncoated side of the carrier (2) and in two-sided coating (3, 4) of the carrier (2) on one of the coatings (3, 4) an adhesive layer (5) can be applied.

10. Damping sheet (1) according to one of claims 1 to 9, characterized in that the existing coating of an elastomer (3, 4) optionally on the carrier (2) existing edges and narrow sides (2a) covers or leaves free.

11. Damping plate (1) according to one of claims 1 to 10, characterized in that the elastomer of the coating (3, 4) is a rubber having siloxane groups in the polymer chain, such as a silicone rubber or a fluorine-silicone rubber.

12. Damping plate (1) according to any one of claims 1 to 11, characterized in that the elastomer of the coating (3, 4) is a sphtzgießfähiger material such as an acrylate copolymer rubber (ACM), an acrylonitrile-butadiene rubber (NBR or HNBR) or a fluorine-containing rubber (FKM).

13, damping plate (1) according to one of claims 1 to 12, dadu rch in that a thickness (D, H10, H11, H12, H13) of the elastomeric coating (3, 4) in the range of about 20 to 5000 microns, preferably - In particular, the thickness (D) in non-structured surface areas - in the range of 20 to 200 microns, is located.

14, damping plate (1) according to one of claims 1 to 13, dadu rch in that a thickness (D, H10, H11, H12, H13) of the elastomeric coating (3, 4) over the surface of the carrier (2) varies ,

15. damping plate (1) according to one of claims 1 to 14, dad u rch geken Ize et n et that by the coating (3, 4) surface structures (10, 11, 12, 13), such as point-shaped profiles (10), line-shaped profiles (11) or sheet-like profiles (12, 13), such. B. annular structures (13) are formed.

16. Damping plate (1) according to claim 15, characterized in that the surface structures (10, 11, 12, 13) intersect and / or for setting an optimal area or line pressure with a brake cylinder (9) of the disc brake (DB) and for adjusting their damping characteristic over their path (S) in their dimensions, such as the width (B10, B11, B12, B13) or the height (H10, H11, H12, H13), vary and / or in their area (A10, A11, A12, A13) are of different sizes.

17, damping plate (1) according to claim 15 or 16, characterized in that by the surface structures (10, 11, 12, 13) sealing elements, fixing and / or positioning aids are formed.