DE102017207724A1 - Brake caliper of a disc brake of a vehicle - Google Patents

Abstract

The invention relates to a caliper of a disc brake of a vehicle comprising at least one cylinder bore for slidably receiving a cup-shaped brake piston, which brake piston has a closed saddle-side end face and an annular lining-side end face, and at least one suitable for pressing against a brake pad of the disc brake intermediate element, which intermediate element at the piston-side end face is connected to the brake piston and prevents direct contact between the brake piston and the brake pad. And wherein the lining-side end face of the intermediate element can be supported on the brake pad. The intermediate element is a metal cushion element.

Description

The invention relates to a brake caliper of a disc brake of a vehicle according to the preamble of claim 1. The prior art is by way of example on the DE 31 48 873 A1 as well as on the DE 31 19 921 A1 and the EP 2 980 437 A1 directed.

Conventional brake calipers of a disc brake of a vehicle, which are known from the prior art, usually comprise a cylinder bore for slidably receiving a cup-shaped piston. The displacement of the piston is done usually by means of a hydraulic fluid. At a brake actuation, the brake piston or pistons press a brake pad against a brake disk rotating during the drive of the vehicle. By means of the friction of the brake pads on the brake disc, the kinetic energy of the vehicle is converted into heat. The vehicle brakes.

A major difficulty in the design and construction of such calipers, especially in brake calipers for disc brakes, is the removal of heat generated during braking or the avoidance of excessive heating of the hydraulic fluid. In order to avoid braking force losses so-called insulating body are known from the prior art, which are arranged between the brake piston and the brake pad and thus reduce the heat input from the hot brake pads on the brake piston in the hydraulic fluid. Such a caliper is for example in the DE 31 19 921 A1 demonstrated. In the DE 31 19 921 A1 the brake piston consists of a thermosetting synthetic resin and has an open end, which comes into contact with the brake pad or the back plate of the brake pad. This open end is thermally insulated by a coating of heat resistant material. A piston made of a plastic, as can be seen in the last-mentioned document, although significantly reduced in weight, but due to the material due to the sometimes very high heat input is not equally resilient as a metallic, usually a made of an iron material piston.

In addition, insulating materials or inserts, as used for example in the DE 31 48 873 A1 Use find, very expensive and expensive to manufacture and during assembly in the brake piston. In addition, the insulation layer at a too small depth or wall thickness (ie how far this protrudes into the cup-shaped brake piston), as it is in the DE 31 48 873 A1 can be recognized, limited in their effectiveness.

Furthermore, in addition to the problem of high heat input and acoustic problems caused by vibrations from the brake disc in the brake caliper at a braking intervention. Such vibrations or vibrations are perceived as unpleasant noises for the vehicle occupants.

From the state of the art so-called metal cushions are known for vibration damping. Metal cushions are formed parts made of a wire mesh with elastic properties, which are used independently or in combination with fittings, for example. They serve to optimize the vibration isolation and noise reduction. Typical applications include exhaust systems, powertrain / powertrain, electronics, filtration / emissions, bodywork, attachments, engine, ancillaries and safety systems. The EP 2 980 437 A1 For example, shows the use of such a metal cushion as a vibration-damping fastening system.

It is an object of the invention to provide a brake caliper disc brake of a vehicle, which provides the necessary strength and rigidity to act in the best possible in all operating situations of the vehicle and which simultaneously ensures the best possible isolation of the hydraulic fluid and a good vibration damping to avoid unwanted noise.

The solution of the problem results from a caliper of a disc brake of a vehicle with the features of claim 1. Advantageous embodiments and further developments are the subject of the dependent claims.

It is proposed a caliper of a disc brake of a vehicle, which comprises at least one cylinder bore for slidably receiving a cup-shaped, preferably metallic, brake piston. The brake piston in this case has a closed saddle-side end face and a preferably annular lining-side end face. Furthermore, at least one intermediate element which is suitable for pressing on a brake pad or on a brake pad back plate of the disc brake is arranged on the (preferably open) lining-side end face of the brake piston. The intermediate element is connected to the brake piston and prevents direct contact between the brake piston, more precisely between the lining-side end of the brake piston and the brake pad or a so-called brake pad back plate.

According to the invention, said intermediate element is a metal cushion element.

A brake pad as defined in the context of this invention usually includes a said brake pad back plate as a support plate which faces the brake piston and is in this case in contact with the metal pad element, as well as a friction means which faces the brake disc and during a braking operation against the brake disc is pressed.

Such a metal pad element describes a molded part, which is formed from a wire mesh, in particular from a chromium-nickel steel wire mesh (CrNi). It has elastic properties, making it ideal for damping, isolating and decoupling vibrations. In the prior art, such cushions are also referred to as all-metal cushions. The spring characteristic of such an all-metal cushion has a pronounced hysteresis. Your contribution is a measure of the existing damping. This is caused by friction between the individual turns of the wire. The resulting heat is dissipated to the outside.

As a decoupling element on the brake caliper or on the brake piston, the metal cushion element serves as a type of elastic intermediate layers and can thus reduce vibration amplitudes and decouple the caliper of the brake disc vibration side.

As already mentioned, it is preferable that the metal pad element is made of a CrNi steel wire. To produce this metal cushion element, a metal wire can be knitted, corrugated, rolled up and pressed into the desired shape, for example on suitable machines. Although the thermal conductivity of such metallic materials is comparatively high, however, the heat generated by a braking engagement may be released to the environment due to the large surface area of the metal pad element.

In a preferred embodiment of the invention, the metal cushion element comprises at least one (recordable metallic) sleeve, which sleeve surrounds at least one end face, that is to say the lining-side and / or the piston-side end face of the metal cushion element. Particularly preferred is located on both end faces such a sleeve or metal disc. Under such a sleeve, for example, a disc-like, smooth and flat metal element or a metal disc is to be understood, which is arranged as a contact surface between the actual constructed of the metal wire or wire mesh metal pad element and the piston or the brake pad (more precisely, the brake pad back plate) , As a result, the pressed wire knot or wire mesh of the metal cushion element can be protected and, in addition, a two-dimensional introduction of force or force transmission can be ensured.

A sleeve or metal disc described last is preferably welded to the wire element. In this case, spot welding is particularly preferably used. Due to the preferred embodiment of the sleeve or the disc as a metallic element (for example, as stainless steel), a weld offers a simple and inexpensive joining method.

Alternatively, the sleeve may also be formed of another material, for example a heat-insulating material, such as a ceramic. In addition to a weld then offers a bonding or pressing the sleeve with the wire mesh. An embodiment of the sleeve of a heat-insulating material (for example, ceramic) has the advantage that both an excellent vibration damping (by the wire mesh), as well as a good thermal insulation (by the insulating sleeve) is ensured.

The metal cushion element is preferably annular or at least approximately tubular. The tubular metal cushion element can therefore have, for example, the same outer tube and inner tube diameter throughout or differ at different regions in its outer tube diameter. Thus, for example, the pipe outer diameter at the brake pad contacting end (the lining-side end face) of the tubular metal pad member having a larger pipe outside diameter (in the form of a collar) than the inner diameter of the cup-shaped piston. However, in order to project into the cup-shaped piston, the tube outer diameter of the metal pad element changes or decreases at the latest in the region in which it enters the cup-shaped piston. The inner diameter of the pipe can be the same size throughout.

Likewise, it is possible that the brake lining contacting end (ie the lining-side end face) of the metal pad element is closed and thus constitutes a circular surface.

Thus, in contrast to a tube with a continuously unchanged outer and inner diameter due to an increased use of material higher strength of the metal cushion element can be ensured. On the other hand, with a uniform pipe outside and inside diameter of the metal pad member, wherein the pipe outside diameter may correspond to the maximum inner diameter of the cup-shaped piston, a minimum contact surface between the metal pad member and the brake pad back plate guaranteed. Such a minimum surface contact means that the amount of heat transferred between the metal cushion element and the brake piston is also reduced.

The connection between the metal cushion element and the brake piston can, as already described, be in the form of a press connection, in which a part of the metal cushion element or the piston-side end face of the metal cushion element projects into the cup-shaped brake piston and pressed into it is. In this case, both the wire mesh of the metal cushion element directly or else a sleeve mentioned can be in contact with the piston.

As an alternative to a stated press connection of the metal cushion element to the brake piston, it is also possible to glue the metal cushion element to the brake piston, to weld it, to screw it or to join it by means of a positive connection.

Furthermore, it is possible that a receiving groove for receiving a preferably likewise annular metal cushion element is provided on the annular end face of the brake piston. The metal pad element can then be inserted and fixed in the receiving groove on the brake piston. In addition, also the brake pad back plate may comprise such a receiving groove for a (preferably annular) metal pad element. A uniform force transmission or force transmission can thus be ensured.

In addition to the aforementioned acoustic decoupling and heat insulation (in particular with one or two surrounding the end faces of the metal cushion element heat-insulating sleeve), a further advantage of the caliper according to the invention will be described below. Due to the high forces acting on the brake caliper during braking, it is necessary that brake calipers, in particular so-called floating calipers, be made as robust as possible and with a high rigidity. Due to uneven loads, there is often an uneven wear of the brake pads on the brake caliper.

For example, one side of the brake pad is worn more during the lifetime and the other side of the same brake pad less worn. The caliper according to the invention with said metal pad element allows a tolerance compensation of uneven forces and loads, with a non-uniform or one-sided wear of the brake pads or the brake pad can be prevented. Because of the resilient or elastic property of the metal cushion element, this inhomogeneity in the load can be compensated.

In order to reduce or avoid a negative response of the brake by the additional spring travel of the metal pad element, it is advantageous to design or compress the metal pad element or the wire mesh of the metal pad element accordingly "hard" before assembly, so that a lower residual spring travel is present.

It is also possible to use a brake assist, which causes a pre-compression of the metal pad element upon detection of a possible brake engagement, so that the desired response during the actual subsequent braking intervention can be achieved.

These and other features will become apparent from the claims and from the description also from the drawings, wherein the individual features each alone or more in the form of sub-combinations in one embodiment of the invention be realized and represent advantageous and inherently protectable versions for which protection is claimed here.

In the following, the invention will be further explained with reference to three exemplary embodiments. Essential to the invention may be all features described in more detail.

In the three figures 1 . 2 and 3 is in each case schematically a cross section of a brake piston, which is adjacent to a brake lining with the interposition of a metal pad element.

In 1 is a first embodiment of a caliper according to the invention or a cross section of a located in a caliper brake piston 1 schematically shown which brake piston 1 with the interposition of a metal cushion element 3 to a brake pad 2 borders. The cup-shaped caliper 1 is in the 1 to 3 in a detailed view and only partially shown. Since it is a rotationally symmetrical drawing, the reference numerals of the individual components are listed only on one side of the axis of symmetry.

The brake pad 2 includes itself at a braking engagement with the metal pad element 3 adjacent brake pad back plate 2.2 and one with a brake disc 5 Contactable friction agent 2.1 ,

The metal cushion element 3 out 1 includes a wire knit element 3.1 , which of two flat or flat sleeves or discs, a piston-side disc 3.3 and a cover-side disc 3.2 is surrounded. The piston side disc 3.3 is designed in stages, said stage 4 the connection of the metal cushion element 3 with the inner diameter of the piston 1 realized. The stage 4 is especially in the inner diameter of the piston 1 pressed so that both in the axial and in the radial direction of the piston 1 sufficiently strong connection between the piston 1 and the metal cushion element 3 is present. The knitted wire 3.1 of the metal pillow element 3 is with the discs 3.2 . 3.3 each firmly connected. For example, the discs can 3.2 . 3.3 via a welded connection, in particular a spot welding connection, with the wire knit 3.1 be connected.

The disks 3.2 . 3.3 may be formed of a metallic material, such as a stainless steel. However, it is also possible that the discs 3.2 . 3.3 are formed of a heat-insulating material, such as a ceramic or a suitable plastic. It is also possible that the two discs 3.2 . 3.3 are formed of different materials.

The disks 3.2 . 3.3 serve a uniform force application of the braking force from the piston 1 coming over the brake pad 2 on a brake disc 5 and to compensate for possible tolerances. When using heat-insulating discs 3.2 . 3.3 These also serve for thermal insulation.

Furthermore, the metal cushion element 3 out 1 ring-shaped. An annular formation of the metal pad element 3 offers in contrast to a continuous circular formation of the metal pad element 3 as it is in 2 is shown (and what the only difference to the execution of 1 represents), a low material requirement and thus a weight saving. A circular formation of the metal cushion element 3 while providing more stability.

In 3 is the metal cushion element 3 without the discs shown 1 and 2 educated. It is therefore just as possible, for example in terms of lightweight construction, to omit the discs and the wire mesh 3.1 in direct contact with the piston 1 on the one hand and the brake pad 2 on the other hand.

For connecting the wire mesh 3.1 on the brake piston 1 is a stepped training of wire mesh 3.1 as it is in the 1 and 2 the disc 3.3 takes over, possible.

As in 3 However, it is also possible, in particular with regard to a simple and uncomplicated manufacture of the wire mesh 3.1 , a recess 1.1 on the piston 1 and optionally also a recess on the brake pad 2 or on the brake pad back plate 2.2 for inserting or pressing in the (ring-shaped) wire mesh 3.1 provided. The knitted wire 3.1 can then into the recess 1.1 of the piston 1 be pressed or glued.

LIST OF REFERENCE NUMBERS

1

brake pistons

1.1

recess

2

brake lining

2.1

friction means

2.2

Brake pad backing plate

2.2.1

recess

3

Metal cushion element

3.1

Wire mesh

3.2

disc

3.3

disc

4

step

5

brake disc

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3148873 A1 [0001, 0004]
• DE 3119921 A1 [0001, 0003]
• EP 2980437 A1 [0001, 0006]

Claims (8)

Caliper of a disc brake of a vehicle comprising at least one cylinder bore for slidably receiving a cup-shaped brake piston (1), which brake piston (1) has a closed saddle-side end face and a lining-side end face, and at least one for pressing against a brake pad (2) of the disc brake suitable intermediate element ( 3), which intermediate element (3) comprises a piston-side end face and a lining-side end face, wherein the intermediate element (3) is connected to the piston-side end face with the brake piston (1) and a direct contact between the brake piston (1) and the brake lining (2 ), wherein the lining-side end face of the intermediate element (3) on the brake pad (2) can be supported, characterized in that the intermediate element (3) is a metal pad element (3). Caliper after Claim 1 wherein the metal pad element (3) comprises at least one sleeve (3.2, 3.3), which sleeve (3.2, 3.3) surrounds at least one end face of the metal pad element (3). Caliper after Claim 1 or 2 , wherein the at least one sleeve (3.2, 3.3) is materially connected to the metal pad element (3). Brake caliper according to one of the preceding claims, wherein the metal pad element (3) is annular. Brake caliper after one of the preceding Claims 1 to 3 wherein the metal pad element (3) is cylindrical. Brake caliper according to one of the preceding claims, wherein the metal pad element (3) is pressed with its piston-side end face in an annular lining-side end face of the brake piston (1). Brake caliper according to one of the preceding claims, wherein the metal pad element (3) is non-positively and / or positively and / or materially connected to the brake piston (1). Brake caliper according to one of the preceding claims, wherein the brake piston (1) and / or the brake pad (2) comprises a recess (1.1, 2.2.1) for receiving the metal pad element (3).

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