Brake pad with a surface coating

Abstract

The present invention relates to a brake pad having a surface coating. A brake pad having a surface coating that is operable to enhance the break-in process during normal operation. The surface coating can be formulated using one or more materials present in the friction lining of the brake pad. The surface coating can be formulated using only non-metallic materials.

Description

Technical Field

[0001] The present disclosure relates to brake pads and assemblies of brake pads. Background Art

[0002] Brake pads used in motor vehicles undergo a "run-in" process involving the gradual deposition of friction material onto the surface of the brake disc. After the run-in process, the brake pads exhibit more efficient and smoother transfer of braking power.

[0003] However, the run-in process is time-consuming and can require slow and careful operation to make newly installed brakes most effective. If the brakes are applied before or during the run-in process, the current braking system can suffer from rapid heat buildup, which can cause damage to the brake disc due to warping. If the brake pads are exposed to excessive heat buildup, they themselves can suffer from "polishing" of the surface material, thereby reducing the efficiency of the brakes and shortening the service life of the brake pads. Summary of the Invention

[0004] One aspect of the present disclosure relates to a brake pad that includes a backing plate having a mounting surface, a friction lining having a tribological surface, and a surface coating applied to a portion of the tribological surface. The tribological surface can be arranged parallel to the mounting surface. The surface coating can be attached to the tribological surface using an adhesive. The surface coating can have a predetermined design capable of creating a visual effect on the tribological surface. The surface coating can include a composite material formulated using one or more potassium titanates.

[0005] Another aspect of the present disclosure relates to a brake pad that includes a backing plate having a mounting surface, a friction lining having a tribological surface, and a surface coating applied to a portion of the tribological surface. The tribological surface can be arranged parallel to the mounting surface. The surface coating can be attached to the tribological surface using an adhesive. The surface coating can have a predetermined design capable of creating a visual effect on the tribological surface. The surface coating can include a composite material formulated using only non-metallic materials.

[0006] The above and other aspects of the present disclosure will be explained in more detail below with reference to the accompanying drawings. Brief Description of the Drawings

[0007] Figure 1 is an illustration of a brake pad having a surface coating.

[0008] Figure 2 is an illustration of a brake pad having a surface coating applied in a predetermined design.

[0009] Figure 3 is an illustration of a brake pad having a surface coating applied in a predetermined design.

[0010] Figure 4 Illustration of a brake pad having a surface coating applied in a predetermined design.

[0011] Figure 5 Illustration of a brake pad having a surface coating applied in a predetermined design.

[0012] Figure 6 Illustration of a brake pad having a surface coating applied in a predetermined design.

[0013] Figure 7 Illustration of a brake pad having a surface coating applied in a predetermined design.

[0014] Figure 8 Illustration of a brake pad having a surface coating applied in a predetermined design.

[0015] Figure 9 Illustration of a brake pad having a surface coating applied in a predetermined design.

[0016] Figure 10 Illustration of a brake pad having a surface coating applied in a predetermined design.

[0017] Figure 11 Illustration of a brake pad having a surface coating applied in a predetermined design. DETAILED DESCRIPTION

[0018] The illustrated embodiments are disclosed with reference to the accompanying drawings. However, it is to be understood that the disclosed embodiments are intended to be merely examples that may be embodied in various alternative forms. The figures are not necessarily drawn to scale, and some features may be enlarged or reduced to show details of particular components. The specific structural and functional details disclosed should not be construed as limiting, but rather as a representative basis for teaching one of ordinary skill in the art how to practice the disclosed concepts.

[0019] Figure 1 A brake pad 100 according to one embodiment of the teachings herein is shown. The brake pad 100 includes a backing plate 101 having a mounting surface 103. The mounting surface 103 may be adapted to provide a coupling surface between the backing plate 101 and the friction lining 105. The friction lining 105 may be operative to apply a frictional force to a brake disc to generate braking power for a vehicle. The frictional force of the friction lining 105 is transmitted via a tribological surface 107 that is generally parallel to the mounting surface 103 within certain tolerances. The formulation of the friction lining 105 may be adapted for a particular vehicle type, actuator design, brake disc type, or any combination thereof without departing from the teachings disclosed herein.

[0020] During normal braking operation, the friction lining 105 wears, and during the break-in period of operation, residual material may be left on the surface of the drum rotor. This residual material is referred to as the "transfer layer", and a properly formed transfer layer can improve the efficiency of braking, the smoothness of brake force application, and the service life of the brake pad. Until break-in is complete, the brake can operate at sub-optimal performance.

[0021] The transfer layer also reduces heat build-up during braking, which can prevent damage to the brake disc or adverse effects of heat on the friction lining. However, since the friction lining 105 is formulated to resist wear, the time taken for break-in can be longer than desired. For this reason, the brake pad 100 includes a surface coating 109 applied to the tribological surface 107 of the friction lining 105.

[0022] The surface coating 109 can be advantageously formulated to readily produce a transfer layer having characteristics similar to those of the friction lining 105, except that it forms faster under normal use. The transfer layer produced by the surface coating 109 can exhibit friction characteristics similar to those of the transfer layer produced by the friction lining 105 within certain tolerances, except that the transfer layer can be produced at substantially lower heat levels and substantially fewer braking cycles than the friction lining 105 alone. Accordingly, the brake disc can be protected from heat-related warping, and the friction lining 105 can be protected from adverse conditions caused by heat build-up during break-in. In some prior designs, break-in could require 300 to 400 miles of operation, but adding the surface coating 109 can advantageously reduce the necessary operation to complete break-in. The formulation of the surface coating 109 can be adapted to a particular vehicle type, brake design, brake disc type, friction lining formulation, or any combination thereof without departing from the teachings disclosed herein.

[0023] Based on the formulation of the friction lining 105 and the surface coating 109, braking performance can be improved during break-in. In some embodiments, the friction lining 105 can include a first composite material, and the surface coating 109 can include a second composite material having some of the same constituents as the friction lining 105. In some embodiments, the formulation of the surface coating 109 having some of the constituents of the friction lining 105 can improve the braking function or the effective life of the brake pad.

[0024] The surface coating 109 can be formulated using a variety of materials. In some embodiments, the surface coating 109 can include a composite material of non-metallic materials. In some embodiments, the surface coating 109 can include a composite material of materials such as titanates, lubricants, abrasives, fillers, fibers, binders, or pH regulators. By way of example and not limitation, the titanates in the composite material can include potassium titanate, sodium titanate, and potassium magnesium. By way of example and not limitation, the lubricants in the composite material can include antimony trisulphide, tin sulfide, or zinc sulfide. By way of example and not limitation, the abrasives in the composite material can include zircon, zirconia, alumina, magnetite, or mullite. By way of example and not limitation, the fillers in the composite material can include barite, mica, ceramic pellets, or mineral pellets. By way of example and not limitation, the fibers in the composite material can include ceramic fibers, mineral fibers, or basalt fibers. By way of example and not limitation, the binders in the composite material can include inorganic resins, organic resins, sodium silicate, or poly-blend non-sanded grout. By way of example and not limitation, the pH regulators in the composite material can include lime or caustic soda. Without departing from the teachings disclosed herein, one or more other classes of materials can be used.

[0025] In some embodiments, without departing from the teachings disclosed herein, different forms of materials can be utilized, such as two or more different potassium titanates. Without departing from the teachings disclosed herein, the compositions of the surface coating 109 can vary slightly in their respective ingredient inclusions. For example, one composition can include 70 - 80% resin, 10 - 20% zirconia, 2.5 - 12.5% potassium titanate, and 0 - 5% antimony trisulphide by weight. In another exemplary embodiment, the composition can include 47 - 57% sodium silicate, 16 - 26% zirconia, 16 - 26% barite, 0 - 5% antimony trisulphide, and 0 - 5% magnetite. In yet another exemplary embodiment, the composition can include 20 - 30% poly-blend non-sanded grout, 15 - 25% zirconia, 15 - 20% barite, 0 - 5% antimony trisulphide, 05% magnetite, and up to 30% water.

[0026] Some embodiments may include a composite material having up to 40% zirconia, up to 20% zircon, up to 10% potassium titanate, up to 20% barite, up to 5% ceramic fiber, up to 5% Sb2S3, up to 5% SnS2, up to 5% mica, or some combination of the foregoing ingredients in amounts that do not depart from the teachings disclosed herein. In some embodiments, resin may be utilized to balance the composition if the other ingredients do not result in a 100% mixture, without departing from the teachings disclosed herein. In other embodiments, without departing from the teachings disclosed herein, other compositions may be included.

[0027] The surface coating 109 may be applied to the friction lining 105 using an adhesive. The adhesive may be formulated for a specific cure time that is long enough for a complete application, but also short enough such that adding the surface coating to the brake pad 100 has a minimal impact on manufacturing and production time. In some embodiments, the cure time may be 180 seconds or less. In some embodiments, the cure time may be 60 seconds or less. In some embodiments, a commercial adhesive, such as a fast-drying formulation, may be utilized. In some embodiments, the adhesive may include an aliphatic resin or polyvinyl acetate. Other embodiments may include other formulations without departing from the teachings disclosed herein.

[0028] Figure 1 An illustration of a brake pad 100 is provided having a surface coating 109 uniformly applied over the entire area of the tribological surface 107 of the friction lining 105. Other embodiments may include different applications that may be advantageously used to accommodate different vehicle specifications. The application of the surface coating 109 may be applied using a stamping operation that is operable to accommodate a wide variety of application designs. The stamping operation may advantageously allow for any arbitrary design desired during manufacturing.

[0029] In the depicted embodiment, the surface coating 109 provides a different visual appearance to the friction lining 105 such that the applied design is visually recognizable. This visual distinctiveness may advantageously allow the surface coating 109 to be applied to the friction lining 105 in a manner that allows for branding in addition to operational advantages. The application of the surface coating 109 may utilize any design without departing from the teachings disclosed herein. For example, the design may be sold with a specific aesthetic or trademark design to identify the brake pad as having been manufactured by a specific manufacturer.

[0030] Figure 1Depicts an embodiment in which the surface coating 109 provides complete coverage of the tribological surface 107 of the friction lining 105. Other embodiments may include other configurations of the surface coating 109. By way of example and not limitation, some embodiments may concentrate the surface coating 109 in portions of the tribological surface 107 that are defined to make more frequent contact with the brake disc during operation. In some embodiments, portions of the tribological surface 107 that are defined to experience more frictional force during operation may be characterized by the concentration of the surface coating 109. Without departing from the teachings disclosed herein, other embodiments may include other configurations.

[0031] Figure 2 Is an illustration of a brake pad 200 that utilizes the same backplate 101, friction lining 105, and surface coating 109 formulation as the brake pad 100, but the application of the surface coating 109 forms a pair of spaced-apart circles. Without departing from the teachings disclosed herein, other embodiments may include a different number of circles. Without departing from the teachings disclosed herein, other embodiments may include multiple circles having different sizes or positions relative to the friction lining 105. Without departing from the teachings disclosed herein, other embodiments may include multiple oval shapes other than circles.

[0032] Figure 3 Is an illustration of a brake pad 300 that utilizes the same backplate 101, friction lining 105, and surface coating 109 formulation as the brake pad 100, but the application of the surface coating 109 forms a pair of spaced-apart rings. Without departing from the teachings disclosed herein, other embodiments may include a different number of rings. Without departing from the teachings disclosed herein, other embodiments may include multiple rings having different sizes or positions relative to the friction lining 105.

[0033] Figure 4 Is an illustration of a brake pad 400 that utilizes the same backplate 101, friction lining 105, and surface coating 109 formulation as the brake pad 100, but the application of the surface coating 109 forms a pair of spaced-apart strips. Without departing from the teachings disclosed herein, other embodiments may include a different number of strips. Without departing from the teachings disclosed herein, other embodiments may include multiple strips having different sizes or positions relative to the friction lining 105.

[0034] Figure 5It is an illustration of a brake pad 500 that utilizes the same formulation of a backing plate 101, a friction lining 105, and a surface coating 109 as brake pad 100, but the application of the surface coating 109 forms three spaced-apart stripes. Without departing from the teachings disclosed herein, other embodiments may include a different number of stripes. Without departing from the teachings disclosed herein, other embodiments may include multiple stripes having different sizes or positions relative to the friction lining 105.

[0035] Figure 6 It is an illustration of a brake pad 600 that utilizes the same formulation of a backing plate 101, a friction lining 105, and a surface coating 109 as brake pad 100, but the application of the surface coating 109 forms a pair of angled stripes. Without departing from the teachings disclosed herein, other embodiments may include a different number of stripes. Without departing from the teachings disclosed herein, other embodiments may include multiple stripes having different sizes or positions relative to the friction lining 105.

[0036] Figure 7 It is an illustration of a brake pad 700 that utilizes the same formulation of a backing plate 101, a friction lining 105, and a surface coating 109 as brake pad 100, but the application of the surface coating 109 forms a pair of angled stripes. Without departing from the teachings disclosed herein, other embodiments may include a different number of stripes. Without departing from the teachings disclosed herein, other embodiments may include multiple stripes having different sizes or positions relative to the friction lining 105.

[0037] Figure 8 It is an illustration of a brake pad 800 that utilizes the same formulation of a backing plate 101, a friction lining 105, and a surface coating 109 as brake pad 100, but the application of the surface coating 109 forms stripes. Without departing from the teachings disclosed herein, other embodiments may include a different number of stripes. Without departing from the teachings disclosed herein, other embodiments may include multiple stripes having different sizes or positions relative to the friction lining 105.

[0038] Figure 9This is an illustration of brake pad 900, which utilizes the same configuration of backplate 101, friction lining 105, and surface coating 109 as brake pad 100, but the application of surface coating 109 is applied asymmetrically to the tribological surface of friction lining 105. In particular, the application of surface coating 109 varies with respect to its position along the length x of friction lining 105. In the depicted embodiment, the variation in application changes along length x with respect to the width y of friction lining 105. At the proximal end x1 of length x, all associated widths y are covered by surface coating 109. At the distal end x2 of length x, no part of friction lining 105 is covered by surface coating 109 at any point along width y. The coverage of surface coating 109 with respect to width y gradually decreases between proximal end x1 and distal end x2. In the depicted embodiment, the coverage of surface coating 109 tapers linearly, but other embodiments may include other arrangements without departing from the teachings disclosed herein. In some embodiments, brake pad 900 may be most effectively used in specific brake positions within a vehicle. In such embodiments, the brake pads may be utilized in series to provide effective braking on all wheels of the vehicle, where each brake pad has a specialized design suitable for its specific position when installed in the vehicle, without departing from the teachings disclosed herein.

[0039] In some embodiments, the application of surface coating 109 may provide a geometric pattern. Figure 10 This is an illustration of brake pad 1000, which utilizes the same configuration of backplate 101, friction lining 105, and surface coating 109 as brake pad 100, but the application of surface coating 109 forms a geometric pattern including a hexagonal grid. Figure 11 This is an illustration of brake pad 1100, which utilizes the same configuration of backplate 101, friction lining 105, and surface coating 109 as brake pad 100, but the application of surface coating 109 forms a geometric pattern including a repeating pattern of hexagons. Other embodiments may have other designs or other embodiments without departing from the teachings disclosed herein.

[0040] Although the exemplary embodiments are described above, these embodiments are not intended to describe all possible forms of the disclosed devices and methods. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the claimed disclosure. The features of various embodiments may be combined to form additional embodiments of the disclosed concepts.

Claims

1. A brake pad, comprising: a back plate having a mounting surface; a friction lining, which is attached to the mounting surface and has a tribological surface parallel to the mounting surface within a specific tolerance; and a surface coating, which is attached to a part of the tribological surface using an adhesive and has a predetermined peripheral shape when viewed in a direction perpendicular to the tribological surface, wherein the surface coating is a composite material, and the composite material includes potassium titanate, wherein the predetermined peripheral shape includes a geometry asymmetrically applied to the tribological surface, wherein the tribological surface includes a proximal end and a distal end opposite to the proximal end, and wherein the geometry continuously and gradually decreases in width along the direction from the proximal end to the distal end, wherein the surface coating is configured to leave residual material on the surface of the brake rotor during a braking operation so as to generate a transfer layer on the brake rotor, and wherein the predetermined peripheral shape is located at a part of the tribological surface that more frequently contacts the brake rotor and / or experiences more frictional force during operation.

2. The brake pad according to claim 1, wherein, The composite material includes at least two different potassium titanates.

3. The brake pad according to claim 1, wherein The surface coating is visually different from the friction lining.

4. The brake pad according to claim 1, wherein, The adhesive has a curing time of no more than 180 seconds within a specific tolerance.

5. The brake pad according to claim 1, wherein, The surface coating is attached to the tribological surface using a stamping process.

6. The brake pad according to claim 1, wherein, The composite material only includes non-metallic materials.

7. The brake pad according to claim 1, wherein, The composite material includes material components that also exist in the friction lining.

8. The brake pad according to claim 1, wherein The composite material includes at least two materials selected from the list including inorganic resin, organic resin, sodium silicate, multi-blended sandless grout, zirconia, zircon, barite, antimony trisulfide, and magnetite.

9. A brake pad, comprising: a back plate having a mounting surface; a friction lining, which is attached to the mounting surface and has a tribological surface parallel to the mounting surface within a specific tolerance; and a surface coating, which is attached to a part of the tribological surface using an adhesive and has a predetermined peripheral shape when viewed in a direction perpendicular to the tribological surface, wherein the surface coating is a composite material, and the composite material only includes non-metallic materials, wherein the predetermined peripheral shape includes a geometry asymmetrically applied to the tribological surface, wherein the tribological surface includes a proximal end and a distal end opposite to the proximal end, and wherein the geometry continuously and gradually decreases in width along the direction from the proximal end to the distal end, wherein the surface coating is configured to leave residual material on the surface of the brake rotor during a braking operation so as to generate a transfer layer on the brake rotor, and wherein the predetermined peripheral shape is located at a part of the tribological surface that more frequently contacts the brake rotor and / or experiences more frictional force during operation.

10. The brake pad according to claim 9, wherein, The composite material includes at least two different potassium titanates.

11. The brake pad according to claim 9, wherein, The surface coating is visually different from the friction lining.

12. The brake pad according to claim 9, wherein, The adhesive has a specific curing time of no more than 180 seconds within a specific tolerance.

13. The brake pad according to claim 9, wherein, The surface coating is attached to the tribological surface using a stamping process.

14. The brake pad according to claim 9, wherein, The composite material includes material components that are also present in the friction lining.

15. The brake pad according to claim 9, wherein, The composite material includes at least two materials selected from the list including inorganic resin, organic resin, sodium silicate, multi-blend sandless grout, zirconia, zircon, barite, antimony trisulfide, magnetite, and potassium titanate.

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