JP3008218B2 - Non-asbestos-based friction material molded product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-asbestos-based friction material molded product used for disc pads for vehicles such as automobiles, brake running, clutch facing, and the like. Used in
The present invention relates to a non-asbestos-based friction material molded product suitable for use as a disk pad for a large vehicle and the like.

[0002]

2. Description of the Related Art As is well known, a brake for a vehicle such as an automobile brakes by pressing a brake shoe against an inner surface of a brake drum, and a brake pad by pressing a brake pad against a side surface of a disk-shaped rotor. There are two types of disc brakes.

[0003] In comparison with the above-mentioned drum brake, the above-mentioned disc brake allows heat to escape easily due to its structure.
Although there is an advantage that uniform braking can be easily obtained, a drum brake using a large brake shoe is superior to a disc brake in terms of abrasion resistance.・ Drum brakes are often used for large vehicles and disc brakes are often used for small vehicles.

[0004] Regardless of whether it is for a drum brake or a disc brake, a friction material focused on abrasion resistance at a high temperature is made by incorporating a large amount of a metal component or graphite. Many are designed to increase the overall thermal conductivity and not increase the temperature of the friction surface.

However, as the thermal conductivity of the friction material increases,
Heat generated by friction is transmitted through the brake device to raise the temperature of the brake oil, which may cause a vapor lock phenomenon.Therefore, usually, an insulator is provided between the friction material and the backing metal. As such an insulator material, a material having asbestos as a base material, which is inexpensive and has appropriate strength, has been used in many cases.

[Problems to be solved by the invention]

However, the use of asbestos has been regulated as a result of environmental problems. Therefore, it has been required to convert not only friction materials but also insulator materials to non-asbestos materials.

Further, when a disk brake is used for a medium or large vehicle, the cross-sectional area of the friction material parallel to the friction surface becomes smaller than when a drum brake is used. The friction material to be used is required to have a higher strength as an insulator material.

[0008] The present invention is based on the background of the prior art described above, and is a non-asbestos-based friction provided with an insulator having heat insulating properties and strength enough to withstand braking force during braking of a medium or large vehicle. The main purpose was to provide wood.

[0009]

In order to achieve the above object, the present invention employs a non-asbestos-based friction material comprising a reinforcing fiber other than asbestos, a binder made of a thermosetting resin such as a phenol resin, and a sulfuric acid. In a non-asbestos-based friction material comprising a filler such as barium, a reinforcing fiber other than asbestos and a binder made of a thermosetting resin such as a phenol resin and a filler such as barium sulfate are provided between the friction material and the backing metal. In addition, an insulator containing metal fibers as at least a part of the component and having a thermal conductivity of about 1.0 to about 2.5 kcal / mh ° C is interposed.

In the non-asbestos-based insulator used in the present invention, the metal fibers in the components have an average fiber diameter of about 30 to about 150 μm and an average fiber length of about 0.5 to about 6.
0 mm can be used, and the content of the metal fiber is about 0.5 to about the total amount of the insulator.
A range of about 20% by volume can be exemplified.

The insulator may have a thickness of about 1/5 to about 1/3 of the thickness of the entire friction material molded product.

Hereinafter, the present invention will be described in detail.

The reinforcing fibers other than asbestos used in the non-asbestos-based friction material molded article of the present invention include, for example, organic fibers such as aramid fiber, acrylic fiber, phenol fiber, PVA fiber, cellulose fiber, and glass. One or two of inorganic fibers such as fibers, ceramic fibers, and carbon fibers; and metal fibers such as steel fibers, copper fibers, and bronze fibers.
Mixtures containing more than one type of fiber are used, which are the same as those used in conventional non-asbestos-based friction material moldings.

As the binder, for example, a thermosetting resin such as phenol resin is used. As the filler, for example, barium sulfate, cash dust, calcium carbonate, etc. are used. These are also commonly used in ordinary non-asbestos-based friction material molded products.

The non-asbestos-based friction material molded article of the present invention is characterized in that an insulator containing metal fibers is interposed at least as a part of the component between the friction material and the backing metal.

The insulator is composed of a reinforcing fiber other than asbestos, a binder made of a thermosetting resin such as a phenol resin, and a filler such as barium sulfate. The non-asbestos-based friction material molded product can be used without any particular limitation.

The metal fibers used in the insulator preferably have an average fiber diameter of about 30 to about 150 μm. When the average fiber diameter is about 30 μm or less, the strength is reduced. When the average fiber diameter is about 150 μm or more, the entanglement of the fibers becomes poor. , Again, the strength is reduced.

Preferably, the metal fiber has an average fiber length of about 0.5 to about 6.0 mm, and about 0.5 to about 6.0 mm.
mm or less and about 6.0 mm or more, the entanglement worsens and the strength is reduced.

Further, the content of the metal fiber is preferably about 0.5 to about 20% by volume of the total amount of the insulator, and is preferably about 0.5 to about 20% by volume.
% Or less is not preferable because the strength is insufficient, and if it is about 20% or more, the thermal conductivity becomes high, so that it does not play its original role as an insulator.

It is preferable that the insulator is used, for example, so that the thickness of the insulator is 1/5 to 1/3 of the thickness of the entire friction material molded product.

Further, the insulator has a thermal conductivity of about 1.0 to about 2.5 kcal / mh ° C.,
Since the temperature difference between the friction material and the insulator can be reduced and the generation of thermal stress can be suppressed, it is particularly preferable as a friction material molded product used under a high load.

[0022]

The molded article of the friction material of the present invention comprises a reinforcing fiber other than asbestos, a binder made of a thermosetting resin such as a phenol resin, and a filler such as barium sulfate between the friction material and the backing metal. Including metal fibers at least as part of the component, and having a thermal conductivity of about 1.0 to about 2.5 k.
By interposing an insulator of cal / mh ° C., the strength against braking force is improved from normal temperature to high temperature without impairing the heat insulation.

Now, the present invention will be described in further detail with reference to Examples.

[0024]

Examples 1 to 5 Steel fibers, copper fibers and brass fibers were uniformly mixed with other components in the proportions shown in Table 1 as metal fibers to obtain insulator materials. However, all the metal fibers used had an average fiber diameter of 50 μm and an average fiber length of 3 mm. Next, a friction material material having the following composition is preformed at a pressure of 400 kg / cm ² at room temperature for 1 minute, and then at a pressure of 600 kg / cm ² and a temperature of 150 ° C. for 1 minute.
After performing compression molding for 5 minutes, heat treatment was performed at 200 ° C. for 5 hours to obtain friction materials for disk pads of Examples 1 to 5. Steel fiber 30% by volume Phenol resin 21% by volume Barium sulfate 15% by volume Copper powder 4% by volume Graphite 10% by volume Petroleum coke 20% by volume

[0025]

Comparative Examples 1 to 3 The friction materials of Comparative Examples 1 to 3 were obtained in the same manner as in the above Example except that no metal fiber was used.

[0026]

[Friction test] With respect to the friction material of Examples 1 to 4 and the friction materials of Comparative Examples 1 to 4, a wear test at different temperatures (JASO C427-83, inertia 40 kgms ² ) was performed using a full-size dynamo testing machine. In addition to examining the state of crack initiation at the interface between the friction material and the insulator, a shear strength test between the friction material and the insulator interface (JASO C444)
-78). The results are shown in Table 1 below. still,
Inertia of 40 kgms ² corresponds to a 4 to 5 ton vehicle constant load state.

[Table 1]

[0027]

As is clear from Table 1, the friction material of the present invention in which an insulator containing a metal fiber as at least a part of the component is interposed between the friction material and the backing metal does not impair the heat insulating property. It can be seen that the strength against the braking force has been improved.

Continuation of the front page (51) Int.Cl. ⁷ identification code FI F16D 69/02 F16D 69/02 G (58) Investigated field (Int. Cl. ⁷ , DB name) C09K 3/14 520 C09K 3/14 530 C08J 5/14 F16D 69/00-69/02

Claims (5)

(57) [Claims] 1. A non-asbestos-based friction material comprising a reinforcing fiber other than asbestos, a binder made of a thermosetting resin such as a phenol resin, and a filler such as barium sulfate. A reinforcing fiber, a binder made of a thermosetting resin such as a phenol resin, and a filler such as barium sulfate, and at least a metal fiber as a part of the components, and having a thermal conductivity of about 1.0. ~ About 2.5k
A non-asbestos-based friction material molded product characterized by interposing an insulator at cal / mh ° C. 2. The metal fiber in the component of the insulator,
The non-asbestos-based friction material molded article according to claim 1, wherein the average fiber diameter is about 30 to about 150 µm. 3. The metal fiber in the component of the insulator,
The non-asbestos-based friction material molded article according to claim 1, wherein the average fiber length is about 0.5 to about 6.0 mm. 4. The content of the metal fiber in the component of the insulator is about 0.5 to about 2 with respect to the total amount of the insulator material.
The non-asbestos-based friction material molded product according to claim 1, which is 0% by volume. 5. The non-asbestos-based friction material molded product according to claim 1, wherein the thickness of the insulator is about 1/5 to about 1/3 of the total thickness of the friction material molded product.