Disc brakes for a commercial vehicle

Abstract

Disc brake (10) for a commercial vehicle, comprising a brake caliper (1) designed as a sliding caliper that overlaps a brake disc (2), which is attached to a stationary brake carrier (6) and has a central opening (9) above the brake disc (2), two brake pads (3, 3') arranged in the brake caliper (1), which are movable in opposite directions and each have a pad carrier plate (4) and a friction lining (5) attached thereto, of which one action-side or clamping-side brake pad (3) can be pressed against the brake disc (2) by means of a clamping device via at least one brake piston, and at least one return device (8) with which the brake pads (3, 3') can be returned after a braking-induced displacement and release of the brake, wherein the resetting device (8) has at least one resetting element (18) attached to a brake pad (3, 3') which is arranged between this brake pad (3, 3') and a stationary reference and exerts a resetting force on the brake pad (3, 3'), wherein the at least one return element (18) exerts a tensile force as a return force on the brake pad (3, 3') to which the at least one return element (18) is attached, wherein the at least one return element (18) is attached to a pressure side (4b) of a pad carrier plate (4) of the brake pad (3, 3') wherein the at least one return element (18) is attached with fastening arms (18b) to the pad carrier plate (4) of the brake pad (3, 3') centrally, on an upper, lower and / or lateral edge region of the pad carrier plate (4) wherein the at least one return element (18) is connected to the stationary reference by at least one spring arm (18a), wherein the at least one return element (18) is attached to the rear brake pad (3') and has at least two return units (18') each with at least one mounting arm (18b) and each with one spring arm (18a), wherein the return units (18') are attached to the lateral areas of the pressure side (4b) of the pad carrier plate (4) of the rear brake pad (3') symmetrically to a transverse axis of the pad carrier plate (4) radial with respect to a brake disc rotation axis (2a) of the brake disc (2), wherein each spring arm (18a) of the at least two return units (18') is connected to the brake carrier (6) as a stationary reference, characterized by the fact that The respective spring arm (18a) of the at least two return units (18') has two spring tabs (18h) arranged parallel to each other and parallel to the at least one mounting arm (18b), wherein a first of the two spring tabs (18h) is connected at an inner end to the at least one mounting arm (18b) and at its outer end to the outer end of the second spring tab (18h), wherein the second spring tab (18h) is connected at its inner end to a support section (18f) as a connection of the return unit (18') to the brake carrier (6) as a stationary reference.

Description

[0001] The invention relates to a disc brake for a commercial vehicle according to the preamble of claim 1.

[0002] In a disc brake of this type, also known as a sliding-caliper brake (or floating-caliper brake), an application device that can be actuated pneumatically or by an electric motor presses an action-side brake pad against a vehicle-mounted brake disc during braking. As the braking process continues, the brake caliper is displaced relative to the brake disc in the opposite direction to the application direction of the action-side brake pad, driving and pressing the opposing, reaction-side brake pad against the other side of the brake disc.

[0003] After the brake is released, the brake caliper of a conventional disc brake remains in this position, in which the brake pads, or at least the reaction-side brake pad, are in contact with the brake disc, albeit without pressure. The resulting residual friction torque of the brake pads during driving has a detrimental effect in that it leads to increased fuel consumption and a reduction in the service life of the components involved, namely the brake disc and the brake pads.

[0004] Although a slight release of the brake pads occurs during driving, for example, due to wobbling of the brake disc, as well as vibrations and lateral acceleration when cornering, these effects are not sufficient to effectively prevent the aforementioned residual drag torque. These effects can also lead to the brake pads coming into contact with the brake disc again after the brake pads have been released from the brake disc, which can again create residual drag torque.

[0005] In order to counteract this problem, the generic DE 10 2007 001 213 A1 discloses a disc brake with a return device which is arranged in one of the guide bars, by means of which the brake calliper is displaceably held on the brake carrier, and which has a resilient return element by means of which the brake calliper is displaced into an initial position.

[0006] In principle, this design has proven itself. However, the use of this known reset device in air-operated disc brakes on heavy commercial vehicles can lead to problems, as there are wide ranges of variable influences caused by component tolerances and component deformations, which do not always allow for reliable function of this reset device.

[0007] Similar problems arise with a disc brake such as the one discussed in DE 10 2012 006 111 A1. A reset device is arranged on the side opposite the brake application device, facing the reaction-side brake pad, thereby achieving effective, particularly automatic, reset of the brake caliper while simultaneously minimizing interference with the system's rigidity.

[0008] In any case, the return device acts on the brake calliper, with the brake carrier acting as an abutment.

[0009] DE 43 01 621 A1 describes a floating caliper disc brake with a stationary brake carrier which has two carrier arms projecting over the outer edge of a brake disc, with brake shoes arranged on both sides of the brake disc, each having a friction lining and a backing plate, which are movably supported on the carrier arms, with a floating caliper which is guided axially displaceably on the brake carrier, which engages around the brake shoes and has an actuating device intended to press the brake shoes against the brake disc, with a spring arrangement which acts axially on the brake shoes in the brake release direction and which supports the setting of a clearance between the brake shoes and the brake disc after braking.The spring arrangement has at least one spreading spring which is fastened to a support arm of the brake carrier in a completely non-displaceable manner in the axial direction, that the fastening takes place on a section of the support arm located above the outer edge of the brake disc, and that the spreading spring has at least two spring arms which rest resiliently on the back plates of the brake shoes in the axial direction.

[0010] US2014 / 0339026 A1 describes a spreader spring comprising a locking arm connecting the spreader spring to a brake component, a retraction arm, and a pretensioning device arranged between the locking arm and the retraction arm. The pretensioning device comprises six or more spiral loops that store energy during brake activation and retract the brake components (brake pad) once the braking process is complete. A brake caliper in the form of a floating caliper, which is not a sliding caliper, is specified. This is suitable for a passenger vehicle, but not for a commercial vehicle.

[0011] The document DE 20 2016 102 686 U1 relates to a disc brake for a commercial vehicle, with a brake caliper designed as a sliding caliper which spans a brake disc and is fastened to a stationary brake carrier and has a central opening above the brake disc, two brake pads arranged in the brake caliper and movable in opposite directions, each having a pad carrier plate and a friction pad fastened thereto, of which a brake pad on the action side can be pressed against the brake disc by means of an application device via at least one brake piston, and at least one return device with which the brake caliper can be returned after a braking-induced displacement and release of the brake, wherein the return device has a spreading device which engages the opposing brake pads and has the same effect counter to the respective application direction, with resilient spreading elements engaging the respective pad carrier plate.The spreading device is arranged in the central opening, wherein the spreading elements act directly or indirectly outside the friction linings on one side in the central region or on at least two contact areas of the brake linings arranged at a distance from one another from the center, wherein the contact areas each have a contact surface and a support surface on which the spreading elements are movably arranged.

[0012] Document DE 11 2013 004 669 T5 relates to a return spring formed from a metal plate for biasing a brake pad in a return direction to separate from a disc. The return spring is arranged between the brake pad and an attachment member. The return spring includes a fixed portion located on a base end side that is arranged on an ear portion of a back plate of the brake pad. Subsequently, an abutment portion located on a distal end side of the return spring is elastically brought into abutment with an abutment plate portion of a pad spring located on an attachment member side at a position on an outer side in a disc radial direction relative to the fixed portion.As a result, a moment for inclining a position of the brake pad in a direction in which a radial outer side thereof is separated away from the disc in comparison with a radial inner side is applied to the ear portion of the back plate of the brake pad.

[0013] The invention is based on the object of further developing a disc brake of the generic type in such a way that the service life of the brake pads and the brake disc in particular is increased and the overall operating costs are reduced using the simplest structural means.

[0014] This object is achieved by a disc brake having the features of claim 1.

[0015] A disc brake according to the invention for a commercial vehicle, with a brake caliper designed as a sliding caliper which spans a brake disc and is fastened to a stationary brake carrier and has a central opening above the brake disc, two brake pads arranged in the brake caliper, movable in opposite directions, each having a pad carrier plate and a friction pad fastened thereto, of which a brake pad on the action side or application side can be pressed against the brake disc by means of an application device via at least one brake piston, and at least one return device with which the brake pads can be returned after a braking-induced displacement and release of the brake, is designed such that the return device has at least one return element attached to a brake pad, which is arranged between this brake pad and a stationary reference and exerts a return force on the brake pad.

[0016] In addition to a reference to a stationary component (in this case, the brake anchor plate), return elements can also be installed between the brake pads and non-stationary / axially movable components (e.g., brake calipers or pad retaining brackets). These ensure the positioning of the brake pads relative to the movable brake caliper in a floating caliper design. One of the references on the brake caliper can be, for example, its base plate.

[0017] The inventive design of the disc brake achieves synchronous resetting of both brake pads and a resetting of the brake caliper when the brake is released, with the synchronicity affecting both the restoring forces and the resetting paths. A restoring force acts opposite to the respective application direction of the two brake pads, i.e., for the reaction-side (back-side) brake pad, towards the back of the caliper, and for the action-side (application-side) brake pad, towards the caliper head (also referred to as the application section), e.g., towards the pressure piece(s) of the application device, forming gaps, i.e., air play, relative to the brake disc. The total air play provided can thus be adjusted symmetrically to the brake disc by the resetting device.

[0018] The at least one return element is designed as a special spring that actively moves the respective brake pad away from the brake disc after each brake application, thus returning it to its original position. This prevents residual drag torque that can occur if the brake disc and brake pad remain in contact after the brake is released.

[0019] A brake pad set for the disc brake according to the invention comprises at least two brake pads, each with a pad carrier plate and a friction lining mounted on the pad carrier plate. At least one of the brake pads is provided with at least one reset element. This provides the advantage that, due to the pre-assembled reset elements, the brake pads do not need to be subsequently applied when they are inserted. Furthermore, this at least one reset element can be provided on the at least one brake pad regardless of whether it is connected to a stationary or movable reference.

[0020] In the embodiment according to the invention, the at least one return element exerts a tensile force as a return force on the brake pad to which the at least one return element is attached. This results in the advantage of a space-saving installation for resetting the brake pad.

[0021] In an embodiment according to the invention, it is advantageous if the at least one return element is preloaded between the stationary reference and the brake pad. During a braking operation, a further preload is added to this preload, which is caused by the application of the brake. Depending on the design, this preload of the at least one return element can also increase with increasing pad / disk wear.

[0022] In a further embodiment of the invention, the at least one return element is attached to a pressure side of a lining carrier plate of the brake pad. The pressure side of the lining carrier plate is the side of the brake pad that is subjected to a compressive force to apply the brake when the brake is applied. Attaching it to the pressure side is advantageous because the friction lining does not need to be modified.

[0023] In the embodiment according to the invention, the at least one return element with fastening arms is attached centrally to the pad carrier plate of the brake pad, to an upper, lower and / or lateral edge region of the pad carrier plate, wherein the at least one return element is connected to the stationary reference by at least one spring arm. In this way, a uniform introduction of force can be achieved, whereby tilting of the brake pad during resetting can be avoided. It is also conceivable for the at least one return element to be connected to a movable reference, such as the brake caliper or the pad retaining bracket. In this case, a return element can also be connected in part via a first section to a stationary reference and via a second section to a movable reference.

[0024] In a further embodiment of the invention, it is advantageous if the at least one return element is located at least with the undersides of the fastening arms in relation to the brake disc in a vertical plane parallel to a plane of the brake disc, since this enables space-saving installation.

[0025] The inventive design provides that the at least one return element with the at least one spring arm is connected to the brake carrier as a stationary reference. This allows a tensile force to be easily exerted on the respective brake pad.

[0026] In a further embodiment of the invention, the at least one return element with the at least one spring arm is connected to a bridge arch of the brake carrier as a stationary reference. This connection can be, for example, a clamp connection or another type. This results in the advantage of simple assembly. A further advantage is a compact design with a relatively simple return unit.

[0027] In an embodiment not according to the invention, the at least one return element is attached to the brake pad on the application side and connected to the brake carrier by at least one spring arm as a stationary reference via a retaining bracket. This results in a space-saving installation.

[0028] In a further embodiment not according to the invention, the at least one return element is attached to the brake pad on the application side, connected to the brake carrier via the retaining bracket with at least one spring arm as a stationary reference, and additionally connected to the bridge arch of the brake carrier as a stationary reference with at least one further spring arm. These two connections together provide the advantage of uniform tension and force application. In addition, a symmetrical and bilateral adjustment of the air gap can be achieved.

[0029] In a non-inventive embodiment, it is advantageous if the retaining bracket is mounted on the brake caliper between the brake carrier and the guide rails of the axial bearings of the brake caliper, since this eliminates the need for any modifications to the brake carrier. Alternatively, any other type of connection to the stationary brake carrier is also conceivable, e.g., a connection via the brake carrier horns.

[0030] In another embodiment, not according to the invention, the at least one return element is attached to the back-side brake pad with at least one fastening arm, each attached to a lateral region of a pressure side of the pad carrier plate of the back-side brake pad, and connected to two spring arms centrally on a bridge arch of the brake carrier as a stationary reference. The advantage of this is that it allows for simple assembly without modifications or with only minor machining required to create a connection.

[0031] The embodiment according to the invention provides that the at least one return element is attached to the back-side brake pad and has at least two return units, each with at least one fastening arm and one spring arm. The return units are attached to the lateral regions of the pressure side of the pad carrier plate of the back-side brake pad symmetrically to a radial transverse axis of the pad carrier plate with respect to a brake disc rotation axis. This enables a uniform application of tensile force to the back-side brake pad.

[0032] In the embodiment according to the invention, each spring arm of the at least two reset units is connected to the brake carrier as a stationary reference for easy connection.

[0033] In an embodiment not according to the invention, the at least one return element exerts a compressive force as a restoring force on the brake pad with which the at least one return element is in contact. This allows for a wider range of applications.

[0034] For a uniform and effective application of force for resetting, it is advantageous in the embodiment according to the invention if the at least one resetting element is arranged pre-tensioned between the stationary reference and the brake pad.

[0035] In an embodiment not according to the invention, the at least one return element is attached to at least one brake carrier horn of the brake carrier, with the brake carrier forming the stationary reference. This offers the advantage of space-saving installation.

[0036] In yet another embodiment not according to the invention, the at least one return element comprises a holder and at least one compression spring. This enables a compact design.

[0037] In an embodiment not according to the invention, it is advantageous if the at least one compression spring is accommodated in the holder, which is arranged in a recess on the at least one brake carrier horn, since this results in simple assembly.

[0038] A particularly space-saving construction is obtained in an embodiment not according to the invention if the at least one compression spring is supported with one spring end in the holder on a support section and is in contact with the other spring end with a pressure section of the pad carrier plate of the brake pad, wherein the brake pad is subjected to a force which presses it away from the brake disc.

[0039] In another embodiment not according to the invention, the reset device further comprises a spreading device that engages the opposing brake pads and acts in the same way, opposite to the respective application direction, with resilient spreading elements that engage the respective pad carrier plate. Thus, the reset of the brake pads can be additionally assisted by the reset elements.

[0040] In a non-inventive embodiment, the spreading device is arranged in the central opening, with the spreading elements engaging directly or indirectly outside the friction linings of each brake pad on at least two contact areas of the brake pads arranged spaced apart from one another from the center. The spreading device has spring arms that are connected to one another in the central area of ​​the opening and to a retaining bracket attached to the brake carrier. In this way, the spreading device is arranged centrally above the stationary brake disc and is supported by the likewise stationary brake carrier.

[0041] In an embodiment not according to the invention, the spreading device is operatively connected to the brake carrier, which forms an abutment and in which the brake pads are mounted so as to be displaceable coaxially with the brake disc.

[0042] For this purpose, a retaining bracket is provided in a non-inventive embodiment, which spans the brake disc in the peripheral area up to the brake carrier horns of the brake carrier that border a pad recess on both sides and is positioned centrally relative to the brake disc thickness. The retaining bracket is not a pad retaining bracket, but an additional component.

[0043] The expansion device engages the two brake pads conveniently at the pad carrier plates, either on the side facing the attached friction lining or on the opposite back side. To prevent the respective brake pad from tilting during resetting, the expansion element engages either centrally, at an upper exposed edge area of ​​the pad carrier plate, or symmetrically at two contact areas on the right and left.

[0044] For an advantageous space-saving construction in a non-inventive embodiment, the retaining bracket can be arranged in the region of a clamping-side edge of the opening.

[0045] In a non-inventive embodiment, the retaining bracket is mounted between the brake carrier and the guide rails of the brake caliper's axial bearings. The brake carrier can therefore be used without additional modifications or adjustments.

[0046] A further embodiment not according to the invention provides that the expansion elements extend from the central area in the middle of the opening from the inside outward to the contact areas arranged at equal distances from one another from the center. It is also possible for the expansion elements to extend from a central area in the middle of the opening from the inside outward to the contact areas arranged at equal distances from one another from the center.

[0047] In this way, the spreading device, in a non-inventive embodiment, is arranged centrally in the brake caliper, whereby it is also arranged within the envelope of a rim of an associated wheel. The spreading device can also be arranged centrally relative to the brake carrier for functional purposes.

[0048] In a non-inventive embodiment, the central region of the opening extends on both sides of a virtual center of the opening approximately parallel to the plane of the brake disc, with a length ranging from 30 to 50% of the longitudinal axis of the opening. This results in an advantageous adjustment of the spring forces. The opening, through which the brake pads are accessible for maintenance and replacement, thus serves an additional function for the spreading device.

[0049] In a design not according to the invention, the two expansion elements are connected centrally (relative to the support horns). This ensures equal spring force on both the inlet and outlet sides – within a small tolerance range. Different spring forces between the outlet and inlet sides, which can lead to angular wear, are minimized by the one-sided engagement of each spring per pad.

[0050] Yet another embodiment not according to the invention provides that two spring arms each rest against one lining side of an associated pad carrier plate of an associated brake pad via a respective pressure end. For advantageous guidance of the pressure ends, the contact areas of the pressure ends can have projections. This ensures secure support of the spring legs or, in another design variant, the spring arms, even under vibration loads during driving.

[0051] In another embodiment not according to the invention, the spreading device has spring arms, two of which each bear against an associated lining carrier plate, wherein the spring arms are connected to one another in the central region of the opening, which simplifies installation during assembly and maintenance.

[0052] For this purpose, the spring arms are connected to the retaining bracket via a retaining device, wherein the retaining device comprises two retaining arms, each of which extends over the retaining bracket and is firmly connected to it. This results in a simple and stable connection.

[0053] In yet another embodiment not according to the invention, the at least one return element is attached to the brake pad on the application side and is connected by at least one spring arm to the brake carrier as a stationary reference via the retaining bracket to which the spreading device is attached. In this way, the retaining bracket advantageously has additional functions and enables a space-saving and component-saving design.

[0054] In a design not according to the invention, the retaining bracket can be connected to two opposing brackets connected to the brake carrier, which allows for easy connection. The connecting element that connects the expansion elements or spring arms to the retaining bracket can, for example, have elongated holes. These elongated holes can be used to compensate for any manufacturing tolerances. This has the advantage that, thanks to the symmetrical spring properties, the expansion device can be positioned exactly centrally between the brake pads above the disc during assembly.

[0055] Alternatively, in a design not according to the invention, the retaining bracket can be connected to the at least two brake carrier horns of a pad shaft, while the spreading elements engaging both brake pads are connected to the retaining bracket. This thus forms a centering device, which can also be implemented differently in correspondence with the brake carrier as a fixed bearing.

[0056] In a non-inventive embodiment, the retaining bracket is C-shaped in its contour, with a central leg spanning the brake disc to the extent mentioned and two end legs angled in the same direction towards the brake carrier horns, one of which is fastened to a brake carrier horn of the corresponding pad shaft.

[0057] Alternatively, in a non-inventive embodiment, the end legs can each have a tab into which the pins of the brake carrier horns are inserted. This facilitates installation. Of course, the pins can also be inserted separately into the brake carrier horns beforehand, with the tabs having corresponding holes.

[0058] By means of the retaining bracket to which the spreading device is attached with its spring arms, the brake caliper is automatically centered in a non-inventive embodiment after the brake is released, i.e. after braking has ended. The fixed positioning of the spreading device resets the brake pads in such a way that the brake caliper is centered relative to the brake disc. This occurs because the spreading device engages the pad carrier plates and presses them against the pressure pieces of the application device in the case of the brake pad on the application side, and against the back of the caliper in the case of the brake pad on the back side. As a result, the brake caliper is centered indirectly via the brake pads. This has the advantage that, in addition to the brake caliper, the brake pads are also actively reset by the brake disc.

[0059] Furthermore, in an embodiment not according to the invention, the spreading device is designed in such a way that it is effective over the entire wear extent of the brake pads.

[0060] Since the force application points on the brake pads change with increasing wear, the functional parts of the spreading device that contact the brake pads are designed in such a way that they are supported in a sliding manner on the pad carrier plate of the respective brake pads.

[0061] The structural realization of the spreading device not according to the invention can be structurally different, with a significant advantage resulting from the fact that movable components can essentially be dispensed with, with the exception of the resilient spreading elements, which perform a resilient deflection in order to function.

[0062] The now possible omission of moving parts naturally increases the service life of the spreading device not according to the invention, as does the small number of necessary components, which also results in extremely cost-effective production and assembly. - The expansion device not according to the invention comprises two expansion elements, with a first expansion element acting on a first lining and a second expansion element acting on a second lining. The two expansion elements are connected centrally (within the support horns). This ensures equal spring force on both the inlet and outlet sides—within a small tolerance range. Different spring forces between the outlet and inlet sides, which can lead to angular wear, are minimized by the one-sided action of one spring per lining. - A flexible adjustment of the center bar allows for even spring force application on the action and reaction sides, or on the pressure pad and saddle sides. Furthermore, the flexible center bar can compensate for minor geometric misalignments of the disc, pad, and carrier. - The center bar allows the active reset mechanism to be easily positioned and held down by the pad retaining bracket. Advantageously, the reset mechanism can be easily removed and replaced when changing pads. - By utilizing the entire pad cavity between the brake carrier horns, expansion elements or springs with a very low spring rate can be used to apply fairly constant forces during pad wear. Due to the long spring travel, the expansion elements can be tolerant of spring forces. The spring travel results in a constant spring rate with small tolerances. - In a preferred embodiment, only two springs are used. - The expansion elements can be made from cost-effective and geometrically flexible sheet metal.

[0063] Further advantages not according to the invention are: Adjustability (of centering) The spring constant is adjustable for each pad side, which allows for better adaptability for indoor / outdoor use and to different environments - within limits. Installation via the center centering bracket compensates for uneven force buildup. It may also create an "active" saddle centering system.

[0064] The brake pads are indeed retracted from the brake disc after braking by the spreading device (not according to the invention), but the spreading device only engages an upper area of ​​the brake pads. This area of ​​engagement lies outside the center of gravity or a so-called tilting edge of the respective brake pad and can lead to a tilting of the brake pads and promote diagonal wear. Tilting here refers to a tilting of the respective brake pad about a longitudinal axis, which, for example, runs through its center of gravity. This means that the spreading device can cause a tilting moment about this longitudinal axis of the brake pad.

[0065] The term “outside a center of gravity” means that a line of action of a restoring force in a projection onto a vertical plane lying along the brake disc rotation axis does not pass axially through the center of gravity, i.e. not parallel to the brake disc rotation axis.

[0066] In order to prevent such an inclined position of the brake pads caused by tilting, the return device has the additional component of a return force introduction by a pad return unit, i.e. here by one or more return elements in at least one third point of application.

[0067] Thus, in an embodiment not according to the invention, it is provided that the at least one return element engages at least in a third point of engagement in the region of the mean friction radius, the center of gravity or centrally, ie centrally at the intersection point of an imaginary transverse axis and longitudinal axis of the brake pad, symmetrically to the transverse axis at two contact areas to the right and left of it on the longitudinal axis and / or in a lower edge area of ​​the brake pad and reduces a tilting moment generated by a spreading device.

[0068] Therefore, in addition to a reset function or supporting a reset function for the respective brake pad, the reset elements also have the further function of preventing the respective brake pad from tipping over. To this end, the reset elements act at least at the third point of action, for example in the area of ​​the mean friction radius, the center of gravity or centrally, i.e. centrally at the intersection point of the imaginary transverse axis and longitudinal axis of the brake pad, symmetrically to the transverse axis on two contact areas to the right and left of it on the longitudinal axis and / or in a lower edge area of ​​the brake pad. In this way, the tipping moment potentially generated by the spreading device can be reduced or even eliminated.

[0069] In a non-inventive embodiment of the brake pad set, a brake pad on the application side is provided with the return element, wherein the return element is arranged on a pressure side of the brake pad on the application side and attached with at least one fastening arm, and wherein the brake pad set also has a retaining bracket. This provides the advantage of quick and easy installation, since the return element is already pre-mounted on the brake pad.

[0070] Another embodiment of the brake pad set not according to the invention provides that a back-side brake pad is provided with the reset element, wherein the reset element is arranged on a pressure side of the back-side brake pad and attached with at least one fastening arm. This also results in the advantage of quick and easy installation, since the reset element is already pre-mounted on the brake pad. The reset element on the pad carrier plate can be connected to both the stationary brake carrier and the movable brake caliper. In the latter case, however, an additional spring unit is required to center the brake caliper.

[0071] In yet another embodiment not according to the invention, the brake pad set also has a spreading device with a retaining bracket. This can be used for retrofitting or replacement. This makes the brake pad set advantageously versatile.

[0072] In the embodiment according to the invention, it is provided that the respective spring arm of the at least two return units has two spring tabs arranged parallel to one another and parallel to the at least one fastening arm. A first of the two spring tabs is connected to the at least one fastening arm by an inner end and is connected to the outer end of the second spring tab by its outer end. The second spring tab is connected to a support section connecting the return element to the brake carrier as a stationary reference by its inner end. This results in a compact and simple installation.

[0073] Further advantageous embodiments of the invention are characterized in the subclaims.

[0074] Embodiments of the invention are described below with reference to the accompanying drawings.

[0075] They show: Fig. 1 a schematic perspective view of an embodiment of a disc brake not according to the invention with a return device; Fig. 2-3 schematic perspective views of a brake carrier with brake pads and return elements of the return device of the disc brake not according to the invention according to Fig. 1; Fig. 4-5 schematic perspective views of the brake pads after Fig. 2-3; Fig. 6-7 schematic perspective views of a brake carrier with brake pads and a variant of the return device; Fig. 8 a schematic perspective view of the disc brake not according to the invention according to Fig. 1 with the variant of the reset device according to Fig. 6-7; Fig. 9 a schematic partial sectional view of the disc brake not according to the invention according to Fig. 8; Fig. 9a an enlarged sectional view of the connection of the brake calliper with a bearing section on the brake carrier according to Fig. 9; Fig. 10 a schematic perspective view of a retaining bracket of the reset device with a spreading device; Fig. 11 a schematic perspective view of a retaining bracket of the reset device; Fig. 12 a schematic perspective view of a variant of the reset device according to Fig. 7 of a disc brake according to the invention; Fig. 13 an enlarged schematic perspective view of a reset unit of the variant of the reset device according to Fig. 12; Fig. 14 is a schematic sectional view of a further embodiment of a disc brake not according to the invention with a different variant of the return device; and Fig. 15-16 schematic perspective views of the further embodiment according to Fig. 14.

[0076] The Fig. 12 to 13 show an embodiment of a disc brake 10 according to the invention, whereas the Fig. 1 to 11 and 14 to 16 do not represent an embodiment of a disc brake 10 according to the invention.

[0077] The terms “top”, “bottom”, “left”, “right” refer to the respective arrangements in the figures.

[0078] An "upper side" and a "lower side" of a brake pad 3, 3' or a pad carrier plate 4 always refer to the installation situation of the respective brake pad 3, 3'. The lower side of the respective brake pad 3, 3' is located radially closer to a brake disc rotation axis 2a of a brake disc 2 than the upper side of this brake pad 3, 3'.

[0079] The term "transverse axis" of the brake pad 3, 3' refers to an imaginary axis that runs radially to the brake disc rotation axis 2a when the brake pad 3, 3' is installed. A "longitudinal axis" of the brake pad 3, 3' thus runs perpendicular to the transverse axis and tangential to the brake disc 2.

[0080] Fig. 1 shows a schematic perspective view of an embodiment of a disc brake 10 not according to the invention with a return device 8. In the Fig. 2-3 are schematic perspective views of a brake carrier 6 with brake pads 3, 3' and return elements 17, 18 of the return device 8 of the disc brake 10 not according to the invention according to Fig. 1 shown. Fig. 4-5 show schematic perspective views of the brake pads 3, 3' after Fig. 2-3.

[0081] A brake caliper 1 engages over a brake disc 2 with a brake disc rotation axis 2a. The brake caliper 1 is mounted as a so-called sliding caliper on a brake carrier 6 so as to be axially displaceable in the direction of the brake disc rotation axis 2a relative to the brake disc 2. For this purpose, the brake caliper 1 is mounted with bearing sections 26 on guide rails 26b (see Fig. 9) are mounted axially displaceably and are connected to the brake carrier 6 which is fixed to the vehicle.

[0082] The brake caliper 1 comprises an application section 11, a caliper back 12, and two tension struts 13. The application section 11 runs with one side parallel to the plane of the brake disc 2 on one side of the brake disc 2. On the other side of the brake disc 2, the caliper back 12 is arranged, also running parallel to the brake disc 2. The caliper back 12 is connected to the application section 11 at each end by a tension strut 13. The tension struts 13 run essentially at right angles to the application section 11 and the caliper back 12.

[0083] The application section 11 has an interior space in which a not-shown application device of the disc brake 10 is arranged. An opening of the interior space faces the brake disc 2 and is closed with a plate, which is referred to as the base plate 11a (best seen in Fig. 9).

[0084] In this arrangement, the clamping section 11, the saddle back 12, and the tension struts 13 define a central opening 9 between them, which spans the brake disc 2. The opening 9 has an imaginary longitudinal centerline, which lies in the plane of the brake disc 2 and connects the imaginary centers of the tension struts 13. Furthermore, the opening 9 has another imaginary transverse centerline, which connects an imaginary center of the clamping section 11 to an imaginary center of the saddle back 12. The longitudinal centerline and the transverse centerline intersect at an imaginary center point, which is referred to here as the virtual center of the opening 9.

[0085] A brake pad 3, 3' is arranged on each side of the brake disc 2. The brake pad 3 arranged between the brake disc 2 and the application section 11 of the brake caliper 1 is referred to as the action-side or application-side brake pad. The other brake pad 3' is arranged between the brake disc 2 and the caliper back 12 and is referred to as the back-side or reaction-side brake pad 3' and is distinguished from the application-side brake pad 3 by the reference symbol 3'.

[0086] The return device 8 here has two return elements 17, 18, of which the return element 17 is arranged between the brake pad 3 on the application side and the application section 11. The other return element 18 is arranged between the back-side brake pad 3' and the saddle back 12. The return elements 17, 18 are in Fig. 1 hidden by the surrounding components and best placed in the Fig. 2 and Fig. 3 can be recognized. Fig. 1 primarily serves to provide an overview and arrangement of the components of the disc brake 10.

[0087] Fig. Figure 2 shows the brake carrier 6 with the brake pad 3 on the application side. The side of the brake carrier 6 shown, which faces the application section 11 of the brake caliper 1, is referred to as the fastening side 6a. The brake carrier 6 is fastened with its fastening side 6a to a stationary part of an associated vehicle. The fastening side 6a is also provided with two bearing receptacles 6b for the guide bars 26b (see Fig. 9).

[0088] In Fig. 3 shows the brake carrier 6 seen from the other side with the back brake pad 3'.

[0089] The brake pad 3 on the application side is in Fig. 4 with its printed side 4b shown enlarged, where Fig. 5 shows the back brake pad 3' enlarged from its pressure side 4b.

[0090] Each brake pad 3, 3' has a pad carrier plate 4 and, on the side facing the brake disc 2, a friction pad 5 attached to one pad side 4a, which, when in use, i.e., during braking, is pressed against the brake disc 2. The other side of the pad carrier plate 4 is hereinafter referred to as the pressure side 4b. Thus, the application-side brake pad 3 is operatively connected with its pressure side 4b to the application device of the disc brake 10, with the pressure side 4b of the back-side brake pad 3' being in contact with the inside of the caliper back 12 of the brake caliper 1.

[0091] The lining carrier plates 4 of the brake pads 3, 3' each have an upper side 4c, a lower side 4d and two side surfaces 4e (see Fig. 4-5).

[0092] In the brake carrier 6, the brake pads 3, 3' are arranged in so-called pad shafts between two brake carrier horns 6c, 6'c, ​​and rest with sections of their undersides 4d on respective supports (not designated) of a respective pad shaft base of the brake carrier 6. The pad shaft base is formed by a bridge connector 6d, 6'd of the brake carrier 6.

[0093] During braking, the brake pads 3, 3' can be pressed against the brake disc 2 on both sides. The brake pads 3, 3' are accessible for replacement and maintenance through the central opening 9. They can be inserted into and removed from their corresponding pad wells through this central opening 9.

[0094] A rotation arrow around the brake disc rotation axis 2a in Fig. 1 indicates a main direction of rotation for forward travel of the vehicle to which the disc brake 10 is assigned. With respect to the main direction of rotation of the brake disc 2, an inlet side ES and an opposite outlet side AS are defined on the disc brake 10. Accordingly, the brake carrier horns 6c, 6'c on the inlet side ES are called inlet-side brake carrier horns 6c, 6'c, ​​and those on the outlet side AS are called outlet-side brake carrier horns 6c, 6'c.

[0095] A pad retaining bracket 16 is arranged above the brake pads 3, 3' in the transverse direction of the opening 9 or in the direction of the brake disc rotation axis 2a between the application section 11 and the caliper back 12. An application-side retaining end of the pad retaining bracket 16 is fastened in a holding section 14 on the application section 11 of the brake caliper 1, with an opposite, back-side retaining end of the pad retaining bracket 16 being fixed to a holding section 15 of the caliper back 12.

[0096] The pad retaining bracket 16 presses here with sections of its underside onto clamp elements (not designated) of both brake pads 3, 3' and thus also onto their pad retaining springs 7, whereby the brake pads 3, 3' are held in their pad shafts (see Fig. 9) The pad retaining springs 7 are each held on projections on the pad carrier plates 4.

[0097] Braking is effected by means of the application device arranged in a receiving space in the application section 11 of the brake caliper 1, e.g., with a brake lever positioned in a dome of the brake caliper 1. The application-side brake pad 3 initially contacts the brake disc 2 during braking. Subsequently, the brake caliper 1 is displaced in the opposite direction by means of the reaction forces occurring, taking with it the reaction-side brake pad 3', until it also comes into frictional contact with the brake disc 2.

[0098] After the brake is released, the two opposing brake pads 3, 3' are released from the brake disc 2 by means of the return device 8 to such an extent that the latter runs freely relative to the brake pads 3, 3'.

[0099] The return device 8 exerts a force on each brake pad 3, 3', which is referred to below as the return force, which moves the respective brake pad 3, 3' away from the brake disc 2 in the direction of the brake disc rotation axis 2a. In other words, the brake pad 3 on the application side is displaced by the brake disc 2 in the opposite direction to an application force of the application device on the application section 11 of the brake caliper 1, wherein the back-side brake pad 3' is displaced by the brake disc 2 together with the brake caliper 1 in the opposite direction of movement to the brake pad 3 on the application side.

[0100] The restoring force of the restoring device 8 is generated by one or more force storage elements. These force storage elements are designed here as spring elements that are preloaded between the respective brake pad 3, 3' and a stationary reference. The stationary reference refers to components of the disc brake 10 that are fixedly connected to the associated vehicle, such as the brake carrier 6.

[0101] The restoring force can be applied to the respective brake pad 3, 3' as a tensile or / and compressive force. Here, the restoring force is applied to the respective brake pad 3, 3' as a tensile force.

[0102] To apply the restoring force to the respective brake pad 3, 3', the restoring device 8 engages the respective brake pad 3, 3', for example, either centrally, at an upper and / or lower exposed edge area of ​​the pad carrier plate, or symmetrically at two contact areas on the right and left. The contact areas can also be located directly at the respective corner sections 4f of the pad carrier plates 4 at the top and / or bottom. It is of course also possible for the contact points or areas on the respective pad carrier plate 4 to be arranged arbitrarily, e.g., in the middle.

[0103] In this embodiment, the return device comprises at least one return element 17, 18 per brake pad 3, 3'.

[0104] The return element 17 has a plate section 17a, four fastening arms 17b each with a fastening end 17c, two spring arms 17d each with a support section 17e and one spring arm 17f with a support section 17g.

[0105] The plate section 17a is a substantially rectangular plate located in the center of the return element 17 and is connected to the fastening arms 17b and the spring arms 17d, 17f. The connection points are each provided with large rounded portions. One of the fastening arms 17b is arranged at each of the four end regions of the rectangular plate of the plate section 17a. Thus, two upper fastening arms 17b extend upward from the upper end regions of the plate section 17a, and two lower fastening arms 17b extend downward from the lower end regions of the plate section 17a.

[0106] On each of the two narrow sides of the plate section 17a, a spring arm 17d is attached over an arc section and extends upwards after the arc.

[0107] The third spring arm 17f is connected to the plate section 17a in the middle of the lower side and extends downwards.

[0108] The illustrated return element 17 is mounted centrally on the pad carrier plate 4 of the application-side brake pad 3 on the pressure side 4b in such a way that the fastening ends 17c of the upper fastening arms 17b engage around the top side 4c of the pad carrier plate 4, and the fastening ends 17c of the lower fastening arms 17b engage around the bottom side 4c of the pad carrier plate 4. In this example, the fastening ends 17c are bent or folded over for this purpose and provided with end tabs. In this way, the return element 17 can be easily attached to the application-side brake pad 3 as a type of clamp, without the need for any adjustment.

[0109] In the released state of the disc brake 10, the return element 17 lies at least with undersides of the plate section 17a and the fastening arms 17b on the pad carrier plate 4 of the brake pad 3 on the application side in a plane parallel to the brake disc 2 with respect to the brake disc 2. This plane can also be referred to as a vertical plane.

[0110] A distance of the upper fastening arms 17b in a tangential direction to the brake disc 2 is dimensioned here such that it has a length that approximately corresponds to the length of a side surface 4e. This results in two force introduction points or areas that are arranged symmetrically to an imaginary transverse axis of the brake pad 3 on the application side on the upper side 4c of the pad carrier plate 4. In the same way, a distance of the lower fastening arms 17b in a tangential direction to the brake disc 2 is formed, whereby two further force introduction points are also formed on the underside 4d, arranged symmetrically to the imaginary vertical axis.

[0111] When the brake pad 3 is not installed (in Fig. 4), the plate section 17a and the fastening arms 17b rest on the surface of the pressure side 4b of the lining carrier plate 4.

[0112] An imaginary longitudinal axis of the plate section 17a of the return element 17 runs essentially at right angles to the imaginary transverse axis of the brake pad 3 on the application side.

[0113] The two upwardly extending spring arms 17d are arranged to the left and right of mounting arms 17b, respectively. A support section 17e is attached to each of the upper free ends of the spring arms 17d. The support sections 17e are tab-shaped here and angled approximately 90° from the respective spring arm 17d, pointing away from the pressure side 4b of the pad carrier plate 4 of the brake pad 3 on the application side.

[0114] The spring arms 17d form a support or connection for the return element 17 in the installed state of the brake pad 3 on the application side to the above-mentioned stationary reference, for example to the brake carrier 6. For this purpose, the spring arms 17d are fastened via the tab-shaped support sections 17e, for example, to a retaining bracket 25 which is firmly attached to the brake carrier 6. This will be explained in more detail below in connection with the Fig. 8-11 described.

[0115] The downwardly pointing spring arm 17f is provided with a support section 17g at its lower free end. When the brake pad 3 on the application side is installed, this spring arm 17f forms a further support or connection of the return element 17 to the stationary reference. Such an exemplary support on the application-side bridge connector 6d of the stationary brake carrier 6 is shown in Fig. 2. For this purpose, the support section 17g can also be designed as a clamp corresponding to the shape of the bridge connector 6d. Of course, other fastening options, such as riveting or screwing, are also conceivable.

[0116] The return element 17 is thus preloaded between the brake pad 3 and the brake carrier 6, which forms the stationary reference here. Preload is generated in the return element 17 by the spring arms 17d, 17f, which are connected to the mounting arms 17b via the plate section 17a, being resiliently tensioned relative to the mounting arms 17b. The mounting arms 17b can also be tensioned to a certain extent by bending according to the bending beam principle. The resulting spring force is further amplified during a braking operation, since the brake pad 3 moves away from the support points of the spring arms 17d, 17f on the brake carrier 6 towards the brake disc 2 during the braking operation.When the brake is released, this additionally increased spring force of the return element 17 exerts a tensile force on the brake pad 3 via the fastening ends 17c of the fastening arms 17b and thus assists the return of the brake pad 3 on the application side from the brake disc 2 after a braking operation.

[0117] The disc brake 10 shown here is a so-called two-piston disc brake 10 with two pressure pistons that are operatively connected to the pressure side 4b of the pad carrier plate 4 of the brake pad 3 on the application side. For this purpose, the pressure side 4b here has two undesignated elevations that are in contact with the pressure pistons. The return element 17 is arranged centrally between these elevations. In the case of a single-piston disc brake 10, only one pressure piston is in contact with only one elevation, which is now arranged centrally on the pressure side 4b of the pad carrier plate 4 of the brake pad 3 on the application side. In this case, two return elements 17 can be used, e.g., on both sides of this elevation.

[0118] The back brake pad 3' is provided with the return element 18, which is Fig. 3 in the installed state of the rear brake pad 3' and in Fig. 6 is shown enlarged.

[0119] The return element 18 for the back-side brake pad 3' here comprises two spring arms 18a, two fastening arms 18b, each with a fastening end 18c and a fastening tab 18e, and a support section 18f.

[0120] The spring arms 18a are connected together at their opposite ends or are formed integrally. In the connecting area, the support section 18f is mounted in the form of a U-shaped bracket, which protrudes in the direction of the brake disc rotation axis 2a toward the back section 12 of the brake caliper 1. The thus connected spring arms 18a extend in a shape corresponding to the curved contour of the lower edge region of the pressure side 4b of the pad carrier plate 4 of the back-side brake pad 3' to the lower ends of the pad carrier plate 4.

[0121] At each free end of the spring arms 18a, one of the fastening arms 18b is attached. Each fastening arm 18b extends upwards across the entire transverse direction of the lining carrier plate up to a respective corner section 4f of the lining carrier plate 4. At the upper free end of each fastening arm 18b, a fastening end 18c with an end section 18d is formed. The fastening ends 18c are L-shaped with the end sections 18d, wherein the fastening end 18c is folded over by approximately 90° to a respective fastening arm 18b such that its underside rests on the upper side 4c of the respective corner section 4f of the lining carrier plate 4. The respective end section 18d is bent downwards by approximately 90° from the fastening end 18c, runs parallel to the respective fastening arm 18b and lies against the pad side 4a of the pad carrier plate 4 of the back-side brake pad 3'.The fastening ends 18c of the fastening arms 18b of the return element 18 thus form a type of clamp that is arranged and clamped over the upper corner sections 4f of the pad carrier plate 4. An additional fastening element 20 is provided in each case. The fastening element 20 can be, for example, a screw, a rivet, or the like, which fixes the respective end section 18d from the pad side 4a to the pad carrier plate 4 of the back-side brake pad 3'. This is shown in . Fig. 4 can be clearly seen.

[0122] The fastening arms 18b are additionally fastened at their lower ends in the area of ​​the respective connection with the spring arms 18a to the narrow sides of the lining carrier plate 4 of the back-side brake pad 3' by means of a hook-shaped fastening tab 18e. The hook-shaped fastening tabs 18e are for this purpose in recesses 19 in the lower corner areas of the side surfaces 4e of the lining carrier plate 4, e.g., in a clamp-like manner (see e.g. Fig. 4) attached.

[0123] The support section 18f, in the form of a U-shaped bracket, is attached to the spring arms 18a by one leg, with the legs pointing downward. By means of the support section 18f, the return element 18 is centrally attached to the back-side bridge connector 6'd of the stationary brake carrier 6, thus forming the connection between the return element 18 of the back-side brake pad 3' and the stationary reference, here the brake carrier 6.

[0124] In the released state of the disc brake 10, the return element 18 lies at least with undersides of the fastening arms 18b on the pad carrier plate 4 of the back-side brake pad 3' with respect to the brake disc 2 in a plane parallel to the brake disc 2. This plane can also be referred to as a vertical plane.

[0125] The return element 18 of the back-side brake pad 3' is thus mounted in a preloaded manner between the back-side brake pad 3' and the brake carrier 6, which here forms the stationary reference. Preload is generated in the return element 18 by the spring arms 18a, each of which is connected at its outer end to the mounting arms 18b, being resiliently tensioned relative to the mounting arms 18b. The mounting arms 18b can also partially undergo elastic tension, e.g., twisting around their longitudinal axis.

[0126] The resulting spring force is further increased during braking, as the brake pad 3' moves further away from the support point of the spring arms 18a on the brake carrier 6 towards the brake disc 2 during braking. When the brake is released, this additionally increased spring force of the return element 18 exerts a tensile force on the brake pad 3' via the fastening ends 18c on the upper corner sections 4f and via the fastening tabs 18e of the fastening arms 18b on the lower corner sections 4g, thus assisting the return of the rear-side brake pad 3' from the brake disc 2 after braking. This effect is further amplified by the progressive pad wear. Since this increases the preload of the spring force of the return elements 17, 18

[0127] Fig. 6 and Fig. 7 show schematic perspective views of the brake carrier 6 with brake pads 3, 3' and a variant of the return device 8. Fig. 6 shows a view from the clamping side, where Fig. 7 shows a top view. Fig. Figure 8 shows a schematic perspective view of the disc brake 10 Fig. 1 with the variant of the reset device 8 according to Fig. 6-7. Fig. 9 shows a schematic partial sectional view of the disc brake 10 according to Fig. 8, and Fig. 9a shows an enlarged sectional view of the connection of the brake calliper 1 with a bearing section 26 to the brake carrier 6 according to Fig. 9. In Fig. 10 is a schematic perspective view of a retaining bracket 25 of the return device 8 according to Fig. 6-7 with a spreading device 22, and Fig. 11 shows a schematic perspective view of a retaining bracket 25 of the reset device 8.

[0128] The variant of the reset device 8 here consists of two functional groups. The first functional group comprises at least one reset element 17, 18 per brake pad 3, 3', while the second functional group has at least one spreading device 22. The two functional groups are present together here and support each other. However, it is also possible for only one of the two functional groups, or for only one reset element, to be used on only one of the brake pads 3, 3'.

[0129] The return element 17 of the brake pad 3 on the application side has already been described in detail above. Fig. The return element 17 of the variant of the return device 8 shown in Figure 6 differs from this in some points, which will be briefly explained.

[0130] Here, too, the plate section 17a connects the mounting arms 17b and the spring arms 17d and 17f. The upper mounting arms 17b are attached with their lower ends to the narrow sides of the plate section 17a, whereas the upper spring arms 17d are arranged between the mounting arms 17b. This increases the distance between the upper force introduction points / areas. The distance between the lower force introduction points / areas is also increased, since the lower mounting arms 17b are arranged at an outward angle.

[0131] The support section 17g of the lower spring arm 17f is hook-shaped and connected to the application-side bridge connector 6d of the brake carrier 6.

[0132] The upper spring arms 17d are connected with their support sections 17e via the retaining bracket 25 (see Fig. 8 to 11) is connected to the brake carrier 6 as a stationary reference. In addition, a holding device 24 of the spreading device 22 is attached to the holding bracket 25 via holding arms 24a together with the support sections 17e. For this purpose, the holding arms 24, the support sections 17e and the connecting sections 25e (see Fig. 11) are firmly connected by fastening elements 21. The fastening elements 21 can be, for example, rivets, screws, or the like.

[0133] The Fig. The return element 18 of the variant of the return device 8 shown in Fig. 7 differs from the return element 18 of the back-side brake pad 3' already described above in that it consists of two individual return units 18'.

[0134] The reset units 18' are each arranged on a narrow side of the back-side brake pad 3' on the pressure side 4b of the pad carrier plate 4. Each reset unit 18' comprises a spring arm 18a, a fastening arm 18b with a fastening end 18c, and a hook-shaped end portion 18d.

[0135] The fastening arm 18b is attached with its upper fastening end 18c to the upper corner section 4f of the pad carrier plate 4 as or similarly to that already described. The fastening arm 18b extends downwards and is fixed approximately in the middle of the narrow side of the pressure side 4b of the pad carrier plate 4 with its lower end by means of a fastening element 18g, e.g. screw and / or rivet. This fastening can also be implemented by means of a press fit between the fastening arm 18b and a pin / projection cast onto the pad carrier plate 4 or an inserted pin. This lower end of the fastening arm 18b merges into the spring arm 18a at a bend, which thus protrudes obliquely from the pressure side 4b and extends further downwards. The hook-shaped end section 18d is attached to the lower free end of the spring arm 18a. The end section 18d is connected to the stationary reference, i.e. here to the brake carrier 6.This connection point is here at one end of the back bridge arch 6'd of the brake carrier 6.

[0136] The above description of one reset unit 18' also applies to the other reset unit 18' of the back-side reset element 18.

[0137] In the released state of the disc brake 10, this return element 18 also lies at least with undersides of the fastening arms 18b on the pad carrier plate 4 of the back-side brake pad 3' in a plane parallel to the brake disc 2 with respect to the brake disc 2. This plane can also be referred to as a vertical plane.

[0138] The function of the back-side return element 18 has already been explained above.

[0139] The second functional group comprises the spreading device 22, which is explained below.

[0140] The spreading device 22 here comprises two identical pairs of spring arms 23, a holding device 24 and a holding bracket 25. The holding bracket 25 is fixed here between the brake carrier 6 and the guide bars 26b of the bearing sections 26 of the brake calliper 1 on the brake carrier 6 (see Fig. 9) and in this way forms on the stationary reference both, together with the holding arms 24a of the holding device 24, a holder for the pairs of spring arms 23 and a holder for the clamping-side return element 17.

[0141] The spring arms 23 each rest with pressure ends 23b against two opposite end regions of the respective pad carrier plate 4, specifically in a protruding upper edge region of the respective pad side 4a. The ends of the spring arms 23 are also bent into pressure ends 23b, allowing sliding along the respective surface of the respective pad side 4a when the brake is applied and released. Additional projections 4g each form guides for the pressure ends 23b. In this way, the preload resulting from application enables the brake pads 3, 3' to spread or return to their original position after the brake is released.

[0142] Each pair of spring arms 23 interacts with a brake pad 3, 3'. Each pair of spring arms 23 has a central connecting section 23a (see Fig. 7), to which a spring arm 23 is attached at each end in the longitudinal direction and bent from the center toward the respective brake pad 3, 3'. The two pairs of spring arms 23 are firmly connected by their central connecting sections 23a and a connecting section of the holding device 24 in the center of the opening 9 with fastening elements 21a, e.g., screws, rivets, or the like. The connecting sections 23a of the spring arms 23 and the holding device 24 lie parallel to one another and in the plane of the brake disc 2.

[0143] The holding device 24 has two holding arms 24a, one of which is attached to each end of the connecting section and bent toward the clamping section 11. The holding arms 24a extend beyond the retaining bracket 25, which is arranged in the region of a clamping-side edge of the opening 9, and are connected to it as described above.

[0144] The retaining bracket 25 comprises a slightly curved central section 25a. On each side of the central section 25a, an arm 25b extends downwards at approximately 45°. A circular fastening section 25c with an opening is attached to the free end of each of these two arms 25b. Thus, the retaining bracket 25 extends in the installed state ( Fig. 8) with its arms 21b on both sides up to the bearing mounts 6b of the brake carrier 6 on its fastening side 6a (see Fig. 1). In the installed state, the fastening sections 25c with their openings are arranged coaxially to the respective bearing mounts 6b of the brake carrier 6.

[0145] In the execution according to Fig. 10, the upper edges of the arms 25b of the retaining bracket 25 up to the central section 25a are provided with a reinforcement 25d, in the end regions of which, above the ends of the central section 25a, a connecting section 25e forms a horizontal support, e.g. in the form of an angle bracket, and is attached to the retaining bracket 25. These connecting sections 25e serve both for the connection to the ends of each retaining arm 24a of the retaining device 22 resting thereon and for the connection to the support sections 17e of the spring arms 17d of the clamping-side return element 17 (see Fig. 2, Fig. 4, Fig. 6).

[0146] The spreading device 22 is projected in a horizontal plane which is a tangential plane of the brake disc 2 and is perpendicular to the vertical plane of the return elements 17 and 18.

[0147] The retaining bracket 25 can, of course, also be designed without the reinforcements 25d. This is Fig. 11 shown.

[0148] In Fig. 9 and in an enlarged partial sectional view in Fig. 9b shows how the retaining bracket 25 of the return device 8 with its fastening sections 25c and the openings, as already mentioned above, is arranged coaxially to the bearing receptacles 6b for fastening the guide rails 26b by means of bearing screws 26d between the bearing sections 26 and fastening ends 26c of the guide rails 26b and the fastening side 6a of the brake carrier 6.

[0149] In this way, the guide rails 26b are firmly connected to the brake carrier 6 and the fastening sections 25c of the retaining bracket 25 arranged therebetween by the bearing screws 26d. Thus, the guide rails 26b and the retaining bracket 25 are also stationary via the fastening sections 25c, just like the brake carrier 6.

[0150] The Fig. 9 and Fig. The axial bearing shown in Figure 9a comprises the bearing section 26 as a component of the brake caliper 1, the guide bar 26b, the bearing screw 26d, and a bearing element 26a, e.g., an axial bearing bush, arranged between the guide bar 26b and the bearing section 26. This also applies similarly to the other axial bearing.

[0151] The reset device 8 can also be retrofitted into the disc brake 10, e.g., for pad replacement and / or maintenance. This is easily accomplished because the retaining bracket 25 only needs to be retrofitted without any modifications. Likewise, the reset elements 17, 18 are easily attached to the brake pads 3, 3'.

[0152] The first functional group, by means of the return element 17 and / or 18, exerts tensile forces on the brake pads 3, 3' in the middle and / or lower regions of the pad carrier plates 4 of the opposing brake pads 3, 3', counter to the application direction. The second functional group, with the spreading device 22, acts in the upper corner sections 4f on the pad sides 4a of the pad carrier plates 4 of the opposing brake pads 3, 3', also counter to the application direction, with the same effect. In this way, the brake pads 3, 3' are subjected to restoring forces by the return device 8 simultaneously in both their upper regions and their middle and / or lower regions.

[0153] The retaining bracket 25 forms a centering device for the brake calliper 1 in that the brake carrier 6, to which the retaining bracket 25 is attached via the guide bars 26b ( Fig. 9) is attached, forms a stationary part of the stationary reference, relative to which the brake calliper 1 is displaceably mounted, so that after releasing the brake and spreading the spreading device 22 and / or activating the return elements 17, 18, ie pressing / pulling apart the brake pads 3, 3', the brake calliper 1 is guided into a centered position.

[0154] The retaining bracket 25 can, for example, be manufactured as a stamped and bent part, wherein suitable measures can be provided for stiffening, such as stiffeners and beads etc.

[0155] The two spring arms 23 of each pair of spring arms 23 are arranged here in a mirror image to an imaginary longitudinal axis of the opening 9, which lies in a central plane of the brake disc 2.

[0156] In Fig. 12 is a schematic perspective view of a variant of the return device 8 according to Fig. 7 of a disc brake 10 according to the invention. Fig. 13 shows an enlarged schematic perspective view of a reset unit 18' of the variant of the reset device 8 according to Fig. 12.

[0157] Fig. 12 shows a schematic perspective view of the pressure side 4b of the pad carrier plate 4 of the back-side brake pad 3' in its associated pad shaft in the brake carrier 6 between the brake carrier horns 6'c.

[0158] The return element 18 has, like the return element 18 Fig. 7 two reset units 18'.

[0159] In contrast to the variant according to Fig. 7, the return units 18' of this further variant are designed in mirror image and are arranged only in the two lower corner sections 4h of the pad carrier plate 4 of the back-side brake pad 3'.

[0160] Each return unit 18' here comprises a spring arm 18a with two parallel spring tabs 18h, a fastening arm 18b with a fastening end 18c with a folded end section 18d and a support section 18f with a folded end section 18d.

[0161] The fastening arm 18b is provided with a through-hole 18'g for a fastening element 18g (see e.g. Fig. 7). Attached to one end of the fastening arm 18b is the fastening end 18c, folded over by approximately 90°, at whose free end the end section 18d, also folded over by 90°, is formed. The fastening arm 18b rests on the pressure side 4b of the lining carrier plate 4, with the fastening end 18c and the end section 18d engaging around the recess 19 of the lining carrier plate 4 in a hook-like manner. In this way, the reset unit 18' is clamped to the lining carrier plate 4b and fixed by the fastening element 18g (or a similar fastening option).

[0162] At the other end of the fastening arm 18b, a connecting section 18i, bent at 90°, protrudes from the pressure side 4b of the lining carrier plate 4. At its free end, this connecting section is connected to a first spring bracket 18h of the spring arm 18a, which is also bent outward by 90°. Arranged parallel to this spring bracket 18h is a further, second spring bracket 18h, which is connected by its outer end to the outer end of the first spring bracket 18h. The inner end of this second spring bracket 18h is connected to a connecting section 18j, which protrudes at a right angle and points away from the pressure side 4b. This connecting section 18j is twisted around its longitudinal axis and, at its end, merges into the hook-shaped, downward-facing support section 18f with the end section 18d.

[0163] The hook-shaped support section 18f with the end section 18d forms a connection of the reset unit 18' with the stationary reference, ie here with the brake carrier 6.

[0164] The spring tabs 18h of the spring arm 18a, which are arranged parallel to one another, are pre-tensioned and exert a tensile force as a restoring force on the rear-side brake pad 3'.

[0165] The above description also applies to the other, mirror-image reset unit 18'.

[0166] During a braking operation, the return element 18 with its return units 18' is tensioned as explained above and, by being fastened to the pad carrier plate 4, exerts tensile forces to return the back-side brake pad 3' away from the brake disc 2 after a braking operation.

[0167] The spreading device 22 can also be referred to as a first functional group, which engages the upper edges of the brake pads. The engagement of the spreading device 22 on the two brake pads 3, 3' expediently takes place on the respective pad carrier plate 4 of each brake pad 3, 3', specifically on the pad side 4a facing the friction pad 5 attached to it, or on the opposite back side, which is referred to as the pressure side 4b. To prevent the respective brake pad 3, 3' from tilting about its transverse axis during resetting, the spreading device 22 engages either centrally, on an upper, exposed edge area of ​​the pad carrier plate 4, or symmetrically on two contact areas on the right and left.

[0168] The return element 17, 18 can be referred to as a second functional group or as a pad return unit. Each brake pad 3, 3' can be assigned a pad return unit, although it is also possible for only one brake pad 3, 3' to be provided with a pad return unit. The second functional group acts on at least a third point of application on the respective brake pad 3, 3'. This third point of application can be located, for example, in the region of the mean friction radius, the center of gravity or centrally, i.e. centrally at the intersection point of the imaginary transverse axis and longitudinal axis of the brake pad 3, 3', symmetrically to the transverse axis on two contact areas to the right and left of it on the longitudinal axis and / or in a lower edge area of ​​the brake pad 3, 3'.

[0169] The brake pads 3, 3' are indeed already reset by the first functional group, i.e. the spreading device 22, after a braking operation, although the spreading device 22 only acts in an upper area of ​​the brake pads 3, 3'. This area of ​​action lies outside a center of gravity of the respective brake pad 3, 3' and can lead to an inclined position of the brake pads 3, 3' and promote diagonal wear. The inclined position here is understood to mean a so-called tilting of the respective brake pad 3, 3' about a longitudinal axis which runs, for example, through its center of gravity. This means that the spreading device can cause a tilting moment, for example about the center of gravity axis or about a so-called tilting edge of the brake pad 3, 3'.

[0170] The term “outside a center of gravity” means that a line of action of a restoring force in a projection onto a vertical plane lying along the brake disc rotation axis 2a does not run axially through the center of gravity, ie not parallel to the brake disc rotation axis 2a.

[0171] The pad return units or return elements 17, 18 therefore have, in addition to a return function for the respective brake pad 3, 3', the further function of preventing the respective brake pad 3, 3' from tipping over. To this end, the pad return units act at least at the third point of action, for example in the area of ​​the mean friction radius, the center of gravity or centrally, i.e. centrally at the intersection point of the imaginary transverse axis and longitudinal axis of the brake pad 3, 3', symmetrically to the transverse axis on two contact areas to the right and left of it on the longitudinal axis and / or in a lower edge area of ​​the brake pad 3, 3'. In this way, the tipping moment possibly generated by the spreading device 22 can be reduced or even eliminated.

[0172] Fig. 14 shows a schematic sectional view of another embodiment of a disc brake 10 with another variant of the return device 8. Fig. 15 shows a schematic perspective view of the further embodiment according to Fig. 14 with a view of the rear brake pad 3'. In Fig. 16 is a schematic perspective view of the further embodiment according to Fig. 14 with a view of the brake pad 3 on the application side.

[0173] The other variant of the return device 8 shown in this embodiment comprises two return elements 27, 27' per brake pad 3, 3'.

[0174] Each return element 27, 27' has a holder 28, 28' and a compression spring 29, 29'. A compression spring 29, 29' is inserted into each holder 28, 28' such that a force direction of the respective compression spring 29, 29' runs parallel to the brake disc rotation axis 2a, i.e., axially.

[0175] Each bracket 28, 28' is inserted from a pad shaft side into a recess 31, 31' in a respective brake carrier horn 6c, 6'c and secured therein. The recesses 31, 31' correspond in shape to an outer contour of the respective bracket 28, 28'. The recesses 31 of the brake carrier horns 6c on the application side are opposite each other, as is the case with the recesses 31' of the rear-side brake carrier horns 6'c.

[0176] The compression springs 29, 29' are each supported with a spring end facing the brake disc 2 on a support section 28a, 28'a of the brackets 28, 28a. The other spring end of a respective compression spring 29, 29' is in contact with a pressure section 30 of the respective pad carrier plate 4 of the respective associated brake pad 3, 3'. In addition, the end regions with the other spring ends of the compression springs 29, 29' are each in a recess of a respective side surface 4e (see e.g. Fig. 4) of a respective lining carrier plate 4.

[0177] The compression springs 29, 29' are arranged under preload between a respective brake carrier horn 6c, 6'c of the stationary brake carrier 6 and the pad carrier plates 4 of the brake pads 3, 3'. The brake carrier horns 6c, 6'c thus form a stationary reference. The spring forces of the compression springs 29, 29' act in the direction of the brake disc rotation axis 2a on each brake pad 3, 3' in such a way that each brake pad 3, 3' is pressed away from the brake disc 2. Thus, the spring forces of the compression springs 29 act on the application-side brake pad 3 in such a way that it is pressed toward the application section 11 of the brake caliper 1. And the spring forces of the compression springs 29' act on the back-side brake pad 3 in such a way that it is pressed toward the caliper back 12 of the brake caliper 1.

[0178] The return elements 27, 27' are - as shown in the Fig. 15 and Fig. 16 - arranged on an imaginary line tangential to the brake disc 2, which runs approximately through a center of gravity of the brake pads 3, 3' and is located a short distance below the head sides of the brake carrier horns 6c, 6'c. This short distance corresponds here, for example, approximately to the thickness of a pad carrier plate 4.

[0179] The invention is not limited by the embodiments described above. It may be modified within the scope of the appended claims.

[0180] For subsequent installation of the reset device 8 with reset elements 17, 18, the corresponding brake pads 3, 3' can be used during replacement. The spreader device 22 can also be used.

[0181] In addition to a reference to a stationary component (in this case, the brake anchor plate 6), return elements are also possible between the brake pads 3, 3' and non-stationary / axially movable components (e.g., brake caliper 1 or pad retaining bracket 16). These ensure the respective positioning of the brake pads 3, 3' relative to the movable brake caliper 1 in the floating caliper design. One of the references on the brake caliper 1 can, for example, be its base plate 11a (see Fig. 1) be. LIST OF REFERENCE SYMBOLS 1 brake caliper 2 brake discs 2a Brake disc rotation axis 3, 3' brake pad 4 lining carrier plate 4a Covering side 4b Print page 4c top 4d bottom 4th side surface 4f, 4h corner section 4g lead 5 Friction lining 5a slot 6 brake carrier 6a Mounting side 6b Bearing mount 6c, 6'c brake carrier horn 6d, 6'd bridge connectors 7 Pad retaining spring 8 Reset device 9 Opening 10 disc brake 11 Clamping section 11a floor plate 12 saddle backs 13 Tension strut 14, 15 stopping section 16 pad retaining brackets 17 Reset element 17a plate section 17b Mounting arm 17c fastening end 17d, 17f spring arm 17e, 17g support section 18 Reset element 18' reset unit 18a Spring arm 18b Mounting arm 18c fastening end 18d final section 18e mounting tab 18f support section 18g fastener 18'g through opening 18h spring tab 18i, 18j connection 19 Recess 20; 21, 21a Fastening element 22 Spreading device 23 Spring arm 23a connecting section 23b Printing end 24 Holding device 24a Holding arm 25 support brackets 25a Central Section 25b Arm 25c fastening section 25d stiffening section 25e connecting section 26 storage section 26a Bearing element 26b Guide bar 26c fastening end 26d bearing screw 27, 27' return element 28, 28' mount 28a, 28'a support section 29, 29' compression spring 30 Print section 31, 31' recess AS outlet side ES inlet side

Claims

[1] Disc brake (10) for a commercial vehicle, comprising a brake calliper (1) designed as a sliding calliper, which engages over a brake disc (2), is fastened to a stationary brake carrier (6) and has a central opening (9) above the brake disc (2), two brake pads (3, 3') arranged in the brake calliper (1) and movable in opposite directions, each having a pad carrier plate (4) and a friction pad (5) fastened thereto, of which a brake pad (3) on the action side or the application side can be pressed against the brake disc (2) by means of an application device via at least one brake piston, and at least one return device (8) with which the brake pads (3, 3') can be returned after a braking-induced displacement and release of the brake, wherein the restoring device (8) comprises at least one restoring element (18) attached to a brake pad (3, 3'), which is arranged between this brake pad (3, 3') and a stationary reference and exerts a restoring force on the brake pad (3, 3'), wherein the at least one return element (18) exerts a tensile force as a return force on the brake pad (3, 3') to which the at least one return element (18) is attached, wherein the at least one return element (18) is attached to a pressure side (4b) of a lining carrier plate (4) of the brake pad (3, 3'), wherein the at least one return element (18) is attached by fastening arms (18b) to the lining carrier plate (4) of the brake pad (3, 3') centrally, to an upper, lower and / or laterally lying edge region of the lining carrier plate (4), wherein the at least one return element (18) is connected to the stationary reference by at least one spring arm (18a), wherein the at least one return element (18) is attached to the back-side brake pad (3') and has at least two return units (18') each having at least one fastening arm (18b) and one spring arm (18a), wherein the return units (18') are attached to the lateral regions of the pressure side (4b) of the pad carrier plate (4) of the back-side brake pad (3') symmetrically to a radial transverse axis of the pad carrier plate (4) with respect to a brake disc rotation axis (2a) of the brake disc (2), wherein each spring arm (18a) of the at least two return units (18') is connected to the brake carrier (6) as a stationary reference, characterized by , that the respective spring arm (18a) of the at least two return units (18') has two spring tabs (18h) which are arranged parallel to one another and parallel to the at least one fastening arm (18b), wherein a first of the two spring tabs (18h) is connected with an inner end to the at least one fastening arm (18b) and is connected with its outer end to the outer end of the second spring tab (18h), wherein the second spring tab (18h) is connected with its inner end to a support section (18f) as a connection of the return unit (18') to the brake carrier (6) as a stationary reference. [2] Disc brake (10) according to claim 1, characterized by that the at least one return element (18) is arranged pre-tensioned between the stationary reference and the brake pad (3, 3'). [3] Disc brake (10) according to one of the preceding claims, characterized bythat the at least one return element (18) lies at least with undersides of the fastening arms (18b) in relation to the brake disc (2) in a vertical plane parallel to a plane of the brake disc (2). [4] Disc brake (10) according to one of the preceding claims, characterized by that the at least one return element (18) with the at least one spring arm (18a) is connected to a bridge arch (6d, 6'd) of the brake carrier (6) as a stationary reference. [5] Disc brake (10) according to one of the preceding claims, characterized by that a first of the two spring tabs (18h) of the spring arm (18a) of each of the at least two return units (18') is connected with an inner end to the at least one fastening arm (18b) via a first connecting section (18i), wherein the second spring tab (18h) is connected with its inner end to the support section (18f) via a second connecting section (18j). [6] Disc brake (10) according to claim 5, characterized by that the second connecting section (18j) is twisted around its longitudinal axis and merges at its end into the hook-shaped, downward-facing support section (18f). [7] Disc brake (10) according to claim 6, characterized by that the at least one fastening arm (18b) is connected to an end section (18d) by means of a fastening end (18c) bent over by approximately 90° and engages around a recess (19) in the lining carrier plate (4) in a hook-like manner, whereby the return unit (18') is clamped to the lining carrier plate (4b) and fastened by a fastening element (18g) which extends through a through-opening (18'g) in the fastening arm (18b).

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