JP2013057337A - Brake pad, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight brake pad having high strength, and superior in moldability, and to provide a method of manufacturing the same.SOLUTION: This brake pad is formed by laminating and integrally fixing: a friction lining layer including fibers, a binding material, a friction conditioner and a rubber component; and a back plate formed of fiber reinforced plastic. The brake pad is obtained by molding the back plate under a condition of 130-200°C, integrally molding the friction lining layer and the back plate at 0-100°C in the next place, and heating and hardening the whole brake pad. The method of manufacturing the brake pad is also provided.

Description

  The present invention relates to a brake pad used for a disc brake of a two-wheeled vehicle or a four-wheeled vehicle.

  Brake pads used for disc brakes attached to two-wheeled vehicles or four-wheeled vehicles are generally formed by superposing a friction lining layer consisting of base fiber, organic binder, and friction modifier on a steel plate back plate, and hot pressing. Is used.

  With the recent reduction in weight of automobiles, weight reduction is required for undercarriage parts such as brakes. For example, according to Patent Document 1 and Patent Document 2, a back plate for a brake pad is a structure having a reinforcing plate portion provided in a main body meat portion molded from a material containing resin, and therefore the back plate is It was a structure which became lightweight by the main body meat | flesh part being comprised with the material containing resin.

JP-A-5-240273 JP 2004-301134 A

  As a result of examining the structure shown in Patent Documents 1 and 2 above, the weight reduction was certainly achieved, but the heat conduction of the back plate was lowered, and as a result, the friction lining layer was produced when the brake pad was hot-press molded. Compared with the temperature rise rate of the surface layer, the temperature rise rate on the back plate side of the friction lining layer is slow, and the friction lining layer tends to swell, and the production yield may be extremely lowered. Therefore, an object of the present invention is to provide a brake pad that is lightweight and has high strength and excellent moldability, and a method for manufacturing the brake pad.

  In the present invention, a friction lining layer containing fibers, a binder, and a friction modifier and a back plate formed of fiber reinforced plastic are laminated, and the friction lining layer contains a resin and a rubber component and is integrally fixed. The brake pad is obtained by molding the back plate at a temperature of 130 to 200 ° C., and then molding the friction lining layer and the back plate integrally at 0 to 100 ° C., and then heat-curing the entire brake pad. A brake pad (Claim 1) and a manufacturing method thereof (Claim 3).

  In the brake pad according to the invention described in claim 2, a reinforcing plate is provided on both sides or one side of the fiber reinforced plastic to form a back plate formed of the fiber reinforced plastic, and then the friction lining layer and the back plate are integrated. The brake pad according to claim 1, wherein the entire brake pad is heat-cured after being molded.

  The method for manufacturing a brake pad according to a fourth aspect of the present invention provides the brake pad manufacturing method according to the third aspect, wherein the entire brake pad is heat-cured while applying pressure perpendicular to the friction surface of the brake pad. This is a method of manufacturing a brake pad.

According to the present invention, it is possible to provide a brake pad that is lightweight and has high strength and excellent moldability, and a method for manufacturing the brake pad.

  The present invention is a brake pad in which a friction lining layer containing fibers, a binding material, and a friction modifier and a back plate formed of fiber reinforced plastic are laminated and fixed together, and is used as a binding material for the friction lining layer. Contains a resin and rubber component, a fiber reinforced plastic back plate is molded at 130 to 200 ° C., and then the friction lining layer and the back plate are molded integrally at 0 to 100 ° C. A brake pad that is heat-cured and a manufacturing method thereof. According to this configuration, when the back plate and the friction lining layer are formed integrally, the material and the manufacturing process are difficult to swell between the back plate and the friction lining layer. A very reliable brake pad can be obtained against peeling.

  The production method of the back plate used for the brake pad of the present invention is as follows. First, heat-resistant fibers are used as the fibers mixed in the fiber-reinforced plastic raw material. Fibers that do not decompose, shrink or melt at 500 ° C. or lower are preferred. Examples thereof include glass fiber, carbon fiber, metal fiber, ceramic fiber, rock wool, and aramid fiber. The fiber is preferably a short fiber having a fiber length of 10 mm or less so that compression molding, transfer molding, and injection molding can be performed when the fiber reinforced plastic is molded.

  The plastic used for the raw material of the fiber reinforced plastic is preferably a thermosetting resin. In particular, phenol resin, epoxy resin, urea resin, unsaturated polyester resin, diallyl phthalate resin, polyimide resin and the like are preferable.

  The raw material of the fiber reinforced plastic used for molding is a form in which the above-mentioned fiber and a filler for improving strength, elastic modulus, etc. are mixed with the above powdered or liquid resin, compression molding, transfer molding, It is the most suitable form for injection molding.

  Usually, the thickness of the back plate is 2.5 to 7 mm. By reinforcing fiber reinforced plastic from both sides or one side, a brake pad having high strength and high rigidity can be obtained. The material used as the reinforcing plate is preferably a material having a tensile strength of 400 MPa or more. As such a material, an iron plate, an aluminum alloy plate, or a fiber reinforced resin plate based on long fibers can be used. If reinforcing plates are installed on both sides of the fiber reinforced plastic, it is possible to prevent the occurrence of warping due to the difference between the thermal expansion of the reinforcing plate and the fiber reinforced plastic when the back plate is molded, and when the fiber reinforced plastic is cured with resin. .

  In order to mold the back plate, the raw material is preheated, the material is filled in the molding die, and held at 130 to 200 ° C. for several minutes, and the back plate is integrally molded so as to have a predetermined thickness. When the reinforcing plate is integrally molded, the reinforcing plate is set in the molding die so that the reinforcing plate is installed on both sides or one side of the fiber reinforced plastic. When a fiber reinforced resin based on long fibers is used for the reinforcing plate, the prepreg may be set in a mold in advance, and the fiber reinforced resin of the prepreg of the reinforcing plate may be cured simultaneously with the fiber reinforced plastic.

  A friction lining layer is laminated on the back plate thus formed. Apply the adhesive to one side (friction lining layer side) of the back plate manufactured above, set it on the compression molding machine, place the frame mold on it, and put the raw material of the molding powder that will become the friction lining layer into the frame mold. throw into. The friction lining layer is integrated with the back plate, the mold temperature is 0 to 100 ° C., and a pressure of 200 MPa or more is applied as a brake pad surface pressure to form a specified shape.

  Fibers used in the friction lining layer include glass fibers, carbon fibers, metal fibers, ceramic fibers, rock wool, aramid fibers, acrylic fibers, etc., but metal fibers and carbon fibers are used to prevent heat from being transmitted to the back plate. If the volume conductivity is set to 5% by volume or less, and at least the portion in contact with the back plate has a thermal conductivity of 2 W / mK or less, a brake pad in which the resin portion of the back plate is hardly deteriorated can be obtained.

  The binder used for the friction lining layer is preferably an organic binder that is a thermosetting resin, has a phenol skeleton, and is a resin that hardly remains as carbon even when thermally deteriorated. As such an organic binder, a phenol resin, a phenol resin modified with acrylic or various elastomers, or the like can be used.

  The friction lining layer used in the brake pad of the present invention contains a rubber component. In a general method for manufacturing a friction lining layer, a friction material composition in which a friction material material including a binder is mixed is hot-pressed at 100 to 200 ° C., heat-treated, and processed. Here, the temperature of 100 to 200 ° C. is a temperature for the binder in the friction material composition to gel and harden. Usually, the binding material gels during molding, so that the binding material covers the friction material composition, and then cured to maintain a predetermined shape. On the other hand, the friction lining layer used in the brake pad of the present invention can be pressed into a predetermined shape due to the adhesiveness of rubber, so there is no need to perform hot-pressure molding in which the resin of the binder reacts during molding. Molding can be performed in a short time at a temperature of 0 to 100 ° C., and when the back plate and the friction lining layer are molded integrally, the back plate and the friction lining layer are difficult to swell.

  As the rubber used for the friction lining layer, natural rubber or synthetic rubber can be used. As the synthetic rubber, styrene butadiene rubber, polybutadiene rubber, butyl rubber, or the like can be used. Among these, it is preferable to contain 0.5 to 15% by volume of one or more rubbers.

  As the friction modifier used in the friction lining layer, inorganic powder particles such as alumina and zirconia, metal sulfides such as graphite, antimony sulfide and tin sulfide, and organic powders such as cashew dust and rubber dust can be used.

  Next, the friction lining layer is laminated with the back plate and molded integrally, and then heat treatment is performed. This is for accelerating the reaction of the thermosetting resin contained in the friction lining layer and the back plate. In general, the heat treatment is preferably carried out by holding at 180 to 250 ° C. for several hours, where the curing of the thermosetting resin is accelerated and the decomposition reaction does not proceed. In heat curing, it is preferable to heat cure while applying a pressure force perpendicular to the friction surface of the brake pad. In heat curing, when several brake pads are stacked and a load is applied from one end using a spring, a brake pad can be produced while preventing the friction lining layer and the back plate from being separated during heat curing. Moreover, in the manufacturing method of the fiber reinforced plastic backplate which has a reinforcement board, the curvature of the backplate accompanying the thermal expansion difference and the hardening shrinkage | contraction of resin can be reduced.

The brake pads of the present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples.
[Example 1]
A phenolic resin was used as a fiber reinforced plastic binder for the back plate. Glass fibers and rock wool were used as heat resistant fibers to be mixed. The glass fiber to be mixed had an average fiber length of 3.0 mm. A total of 60% by mass of these fibers was mixed to obtain a powdery raw material.

  The powdery raw material was preformed at 70 MPa and preheated to 90 ° C. The pre-heated fiber reinforced plastic raw material was placed in a molding die, held at 160 ° C. and a pressure of 50 MPa for 3 minutes, and molded so that the total thickness of the back plate was 6.5 mm.

The raw material of the molded product to be the friction lining layer is 8% by volume of copper fiber, rock wool, aramid fiber as a base fiber, 20% by volume of phenol resin as an organic binder, 10% by volume of polybutadiene rubber, graphite. In addition, one containing the balance of a friction modifier such as barium sulfate was used.
These materials were stirred with a pressure kneader for 30 minutes to obtain a powdery molding powder raw material.

  In order to produce a brake pad by laminating a friction lining layer on the molded back plate, an adhesive was applied to one side of the back plate. The back plate was set in a compression molding machine, a frame mold was placed thereon, and a molding powder raw material to be a friction lining layer was put into the frame mold. Thereafter, while applying pressure at 100 MPa, the friction lining layer and the back plate were integrally formed and formed into a specified brake pad shape.

  Furthermore, in order to cure the resin used in the friction lining layer and the fiber reinforced plastic, the resin was heated in a heat treatment furnace at 200 ° C. for 4 hours. In the heat treatment, 10 brake pads were stacked, and the brake pads were pressurized at 20 MPa with a spring from one end.

  The brake pad formed in this manner does not cause cracks or peeling between the friction lining layer and the back plate, and the flatness of the plate surface is as good as 0.04 mm, which is about 50 times that of the iron back plate. % Lighter.

[Example 2]
A 3.0 mm steel plate was used as the reinforcing plate and was molded in the same manner as in Example 1. The same friction lining layer as in Example 1 was laminated and formed into a specified brake pad shape. The brake pad molded in this manner does not cause cracks or peeling between the friction lining layer and the back plate, and the flatness of the plate surface is good at 0.10 mm, which is about 70 times that of the iron back plate. % Lighter. Further, in the high temperature durability test, the deformation was reduced as compared with Example 1.

Claims (4)

  A brake pad in which a friction lining layer containing fibers, a binder, a friction modifier, and a rubber component and a back plate formed of fiber reinforced plastic are laminated and fixed together, and the back plate is 130- A brake pad obtained by molding at 200 ° C., then molding the friction lining layer and the back plate integrally at 0 to 100 ° C., and then heat-curing the entire brake pad.   Reinforcement plates are installed on both sides or one side of the fiber reinforced plastic to form a back plate made of fiber reinforced plastic, and then the friction lining layer and the back plate are integrally molded, and then the entire brake pad is heat cured. The brake pad according to claim 1.   A brake pad manufacturing method in which a friction lining layer containing fibers, a binder, a friction modifier, a rubber component and a back plate formed of fiber reinforced plastic or fiber reinforced plastic having a reinforcing plate are laminated and fixed integrally. The back plate is molded under conditions of 130 to 200 ° C., and then the friction lining layer and the back plate are integrally molded at 0 to 100 ° C., and then the brake pad is heated and cured as a whole. .   The method for manufacturing a brake pad according to claim 3, wherein, in the heat curing of the entire brake pad, the heat curing is performed while applying a pressure force perpendicular to the friction surface of the brake pad.