KR101216144B1 - Carbon-ceramic brake disc and method for manufacturing the same - Google Patents

Abstract

Carbon-ceramic brake disc according to the present invention, the body consisting of a first body and a second body; A first friction layer formed in a space between the partition walls protruding from the first body; And a second friction layer formed in a space between the partition walls protruding from the second body.

According to the invention, the friction layer has excellent oxidation resistance. In addition, the surface of the friction layer is uniformly worn. In addition, it is possible to know exactly when to replace the carbon-ceramic brake discs. In addition, it is possible to constantly adjust the crack spacing of the friction layer surface generated during the production of carbon-ceramic brake discs.

Description

Carbon-ceramic brake discs and how to make them {CARBON-CERAMIC BRAKE DISC AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a carbon-ceramic brake disc.

Automobile brakes are divided into drum brakes and disc brakes.

The disc brake consists of a disc and a pad.

Disc brakes slow or stop the rotation of the disc by the friction force generated by the friction between the surface of the disc and the pad, thereby slowing or stopping the rotation of the wheel. Therefore, the disk and the pad should be lightweight and have thermal shock resistance, corrosion resistance, abrasion resistance, high strength, and high coefficient of friction. To this end, discs and pads are made of a carbon fiber reinforced ceramic composite that is lightweight, wear resistant and thermally resistant.

Hereinafter, a disk made of a carbon fiber reinforced ceramic composite is called a carbon-ceramic brake disk.

The carbon-ceramic brake disc is composed of a body, a friction layer laminated on the upper and lower surfaces of the body.

The friction layer has a thickness of about 0.1 to several mm. The friction layer wears as it rubs against the pad, reducing its thickness.

In order for the automobile braking performance to be kept constant, the surface of the friction layer must be constantly worn. In order to uniformly wear the surface of the friction layer, the thickness of the friction layer must be uniform when manufacturing the carbon-ceramic brake disc.

On the other hand, in order to know exactly when to replace the carbon-ceramic brake disc, the wear of the friction layer should be visually confirmed.

On the other hand, in the manufacture of the carbon-ceramic brake disc, when the carbon-ceramic brake disc is cooled, the body has a small coefficient of thermal expansion and the friction layer has a large coefficient of thermal expansion, so that a crack occurs in the friction layer. The cracks generated for this reason are indistinguishable from the cracks newly generated during the use of carbon-ceramic brake discs.

An object of the present invention is first, to make the friction layer in contact with the external air has excellent oxidation resistance.

Second, in the manufacture of carbon-ceramic brake discs, the thickness of the friction layer is uniform.

Third, it is easy to visually check the wear of the friction layer.

Fourth, the friction layer has a narrow width and constant size.

Carbon-ceramic brake disk according to the present invention for achieving the above object, the body consisting of a first body and a second body; A first friction layer formed in a space between the partition walls protruding from the first body; And a second friction layer formed in a space between the partition walls protruding from the second body.

In addition, the above object, the first step of putting the first mixture of carbon fibers and phenol resin mixed in the mold; A second step of heating / pressurizing the first mixture with a press in which the shape of the partition wall is engraved on the bottom surface to form a first body and the partition wall; A third step of filling a space between the partition walls with a second mixture of carbon fibers and phenol resins; A fourth step of making the first friction layer by heating / pressing the second mixture with the press; A fifth step of removing the first carbon-ceramic brake disc formed body comprising the partition wall, the first body, and the first friction layer from the forming mold; A sixth step of making the second carbon-ceramic brake disc molded body by repeating the first to fifth steps, and taking out the second carbon-ceramic brake disc molded body from the mold; The first carbon-ceramic brake disc molded body, a combustible body having a shape of a cooling channel, and the second carbon-ceramic brake disc molded body are sequentially stacked on the mold, and heated / pressurized by the press to form a carbon-ceramic brake. A seventh step of making a disk molded body; An eighth step of applying carbon to the carbon-ceramic brake disc molded body to carbonize it; And a ninth step of melting and infiltrating silicon into a carbon-ceramic brake disc carbonized body in which the carbon-ceramic brake disc molded body is carbonized, and then polishing the silicon-ceramic brake disc molded body.

In addition, the above object, the first step of putting the first mixture of carbon fibers and phenol resin mixed in the mold; A second step of heating / pressurizing the first mixture with a press to make a first body; A third step of making a partition wall by machining on the surface of the first body; A fourth step of filling a space between the partition walls with a second mixture of carbon fibers and phenol resins; A fifth step of heating / pressing the second mixture with the press to form a first friction layer; A sixth step of taking out the first carbon-ceramic brake disc formed body comprising the partition wall, the first body and the first friction layer from the forming mold; A seventh step of making the second carbon-ceramic brake disc molded body by repeating the first to sixth steps, and taking out the second carbon-ceramic brake disc molded body from the mold; The first carbon-ceramic brake disc molded body, a combustible body having a shape of a cooling channel, and the second carbon-ceramic brake disc molded body are sequentially stacked on the mold, and heated / pressurized by the press to form a carbon-ceramic brake. An eighth step of making a disk molded body; A ninth step of heating and carbonizing the carbon-ceramic brake disc molded body; And a tenth step of melting and infiltrating silicon into the carbon-ceramic brake disc carbonized body formed by carbonization of the carbon-ceramic brake disc molded body, and polishing the carbon-ceramic brake disc molded body.

Carbon-ceramic brake discs according to the invention,

First, the friction layer has a component composition ratio of 75 wt% SiC, 24.5 wt% Si and 0.5 wt% C. Therefore, since the carbon component of the friction layer in contact with the external air is 0.5 wt%, the friction layer has excellent oxidation resistance.

Second, since the friction layer is made by filling the second mixture in the space between the partition walls, the height of the partition wall and the friction layer are the same. Therefore, the height of the friction layer can be made uniform, and the surface of the friction layer is uniformly worn.

Third, since the friction layer is light silver and the partition wall is dark gray or black, the friction layer and the partition wall can be easily distinguished with the naked eye. Since the friction layer and the partition wall are worn together, the friction layer is completely worn out if the partition wall is not visible. Therefore, it is possible to know exactly when to replace the carbon-ceramic brake disc.

Fourth, in the production of carbon-ceramic brake discs, cracks in the friction layer cannot proceed any further due to the partition walls. Therefore, by adjusting only the width of the space between the partition walls it is possible to constantly adjust the gap spacing. If the crack spacing is controlled uniformly, it is easy to distinguish it from new cracks that occur during the use of carbon-ceramic brake discs. In addition, the narrow, uniform width of the cracks in the production of carbon-ceramic brake discs is also visible.

Hereinafter, a carbon-ceramic brake disc according to an embodiment of the present invention will be described in detail.

1 is a perspective view showing a carbon-ceramic brake disc according to an embodiment of the present invention. FIG. 2 is a cross-sectional view II-II of FIG. 1.

As shown in FIG. 1 and FIG. 2, the carbon-ceramic brake disc 100 according to the embodiment of the present invention is composed of a body 110, a friction layer 120, and a partition wall 130.

A shaft hole 101 is drilled in the center of the carbon-ceramic brake disc 100.

The body 110 is composed of a first body 111 and a second body 112.

A cooling channel 113 is formed between the first body 111 and the second body 112.

Air enters through the cooling channel 113 to cool the carbon-ceramic brake disc 100.

The first body 111 and the second body 112 has a component composition ratio of SiC 25-50 wt%, Si 0-25 wt%, C 30-60 wt%. Due to this component composition ratio, the first body 111 and the second body 112 is dark gray or black.

The friction layer 120 is composed of a first friction layer 121 and a second friction layer 122.

The first friction layer 121 is formed in a space between the partition walls 130 protruding from the first body 111.

The second friction layer 122 is formed in a space between the partition walls 130 protruding from the second body 112.

 The first friction layer 121 and the second friction layer 122 have a component composition ratio of 75 wt% SiC, 24.5 wt% Si, and 0.5 wt% C. Due to the component composition ratio, the first friction layer 121 and the second friction layer 122 have a bright silver color.

The partition wall 130 includes circular walls arranged in order of increasing diameter from the inner diameter of the friction layers 121 and 122, and a straight wall radially extending toward the outer diameter from the inner diameter of the friction layers 121 and 122. It consists of

When the concentric circle walls and the straight walls intersect, a space S (see FIG. 4C) to fill the second mixture X2 to be described later is formed therebetween.

The partition wall 130 may have various shapes (honeycomb pattern, triangular pattern, square pattern) in addition to the shape shown in FIG. 1.

Hereinafter, a method of manufacturing a carbon-ceramic brake disc according to the first embodiment of the present invention will be described.

3 is a flowchart illustrating a method of manufacturing a carbon-ceramic brake disc according to the first embodiment of the present invention. 4 (a) to 4 (m) are diagrams illustrating first to seventh steps of FIG. 3. The dotted arrows indicate the direction in which the first carbon-ceramic brake disc molded body B1 or the second carbon-ceramic brake disc molded body B2 is taken out of the mold M. As shown in FIG. Solid arrows indicate the vertical movement direction of the press.

Method for manufacturing a carbon-ceramic brake disc according to the first embodiment of the present invention,

As shown in Figure 4 (a), the first step (S11) of putting the first mixture (X1) mixed with carbon fibers and phenolic resin into the molding die (M);

As shown in FIGS. 4 (b) and 4 (c), the first mixture X1 is heated by a press P in which the shape of the partition wall 130 is engraved on the bottom surface of the first mixture X1. / Second step (S12) to make the first body 111 and the partition wall 130 by pressing;

As shown in FIG. 4 (c), a third step S13 of filling the space S between the partition walls 130 with the second mixture X2 in which the carbon fibers and the phenol resin are mixed;

As shown in FIG. 4 (d), a fourth step S14 of heating / pressing the second mixture X2 with a press P to form the first friction layer 121;

As shown in FIG. 4E, the first carbon-ceramic brake disc molded body B1 including the partition wall 130, the first body 111, and the first friction layer 121 is formed in the mold M. Taking out from the fifth step (S15);

As shown in FIGS. 4 (f) to 4 (j), the first steps S11 to fifth steps S15 are repeated to form a second carbon-ceramic brake disc molded body B2, and A sixth step (S16) of taking out the second carbon-ceramic brake disc molded body (B2) from M);

As shown in FIGS. 4 (k) to 4 (m), the first carbon-ceramic brake disc molded body B1 and the combustible body V having the shape of the cooling channel 113 are formed in the mold M. FIG. And a seventh step (S17) of stacking the second carbon-ceramic brake disc molded bodies in order, and heating / pressurizing the press carbon (P) to form the carbon-ceramic brake disc molded body (B).

An eighth step S18 of applying carbon to the carbon-ceramic brake disc molded body B and carbonizing the same;

And a ninth step (S19) of melting and infiltrating silicon into the carbon-ceramic brake disc carbonized body formed by carbonization of the carbon-ceramic brake disc molded body (B) and polishing it.

The first step S11 will be described below.

The first mixture (X1) is made by mixing 50 vol% of carbon fiber and phenol resin. The carbon fiber is 20 mm long.

The second step S12 will be described below.

The temperature at which the first mixture X1 is heated is 120 ° C. To this end, a heater (not shown) is installed in the press P.

The pressure for pressing the first mixture X1 is 4 MPa.

On the surface of the press P, a pattern as shown in FIG. 1 is engraved.

As shown in FIG. 4B, when the press P presses the first mixture X1, the first mixture X1 penetrates into the engraved space.

As shown in FIG. 4C, when the first mixture X1 is hardened, the first body 111 and the partition wall 130 are formed. A space S is formed between the partition walls 130 to fill the second mixture X2.

The partition wall 130 has a width of 0.5 to 1 mm and a height of 0.5 to 2 mm. The surface area of the partition wall 130 should be within 10% of the total area of the first friction layer 121. This is because the braking performance is lowered when the partition wall 130 is exposed to the outside.

The third step S13 will be described below.

The second mixture (X2) is made by mixing 40 vol% of carbon fiber, phenol resin and additives. The length of the carbon fiber is 200 mu m.

As shown in FIGS. 4 (c) and 4 (d), the first friction layer 121 is formed by filling the second mixture X2 in the space S between the partition walls 130. The height H1 (see FIG. 2) of the friction layer 121 and the height H2 (see FIG. 2) of the partition wall 130 are the same.

The fourth step S14 will be described below.

The temperature at which the second mixture X2 is heated is 170 ° C. The pressure for pressing the second mixture X2 is 4 MPa.

The seventh step S17 will be described below.

As shown in Fig. 4 (k), the first carbon-ceramic brake disc molded body B1 is formed so that the first friction layer 121 of the first carbon-ceramic brake disc molded body B1 faces downward. Put it in (M). The combustible V is placed on the first carbon-ceramic brake disc shaped body B1. The second carbon-ceramic brake disc molded body B2 is placed on the combustible V so that the second friction layer 122 of the second carbon-ceramic brake disc molded body B2 faces upward.

Of course, the second carbon-ceramic brake disc molded body B2 is placed in the mold M so that the second friction layer 122 of the second carbon-ceramic brake disc molded body B2 faces downward, and the second carbon The flammable body V is placed on the ceramic brake disc molded body B2, and the first friction layer 121 of the first carbon-ceramic brake disc molded body B1 faces upwards. One carbon-ceramic brake disc shaped body (B1) may be placed thereon.

As shown in Fig. 4 (l) and Fig. 4 (m), when the second friction layer 122 of the second carbon-ceramic brake disc formed body B2 is heated / pressurized by the press P, the first carbon The combustible V penetrates into the first body 111 of the ceramic brake disc formed body B1 and the second body 112 of the second carbon-ceramic brake disc formed body B2, and the first carbon-ceramic The brake disc molded body B1 and the second carbon-ceramic brake disc molded body B2 stick together. Thus, the molded body in which the first carbon-ceramic brake disc molded body B1 and the second carbon-ceramic brake disc molded body B2 are combined is referred to as a carbon-ceramic brake disc molded body B.

Hereinafter, the eighth step (S18) will be described in detail.

The combustible (V) is thermally decomposed at 600 ° C or higher. It is preferable that residual carbon amount is less than 3 wt% after pyrolysis. To this end, the combustible (V) is preferably made of a thermoplastic resin such as ABS resin (Acrylonitrile Butadiene Styrene copolymer), styrene resin (polystyrene), polyethylene (Acrylic resin) and the like.

In an inert gas atmosphere or a vacuum atmosphere, when the carbon-ceramic brake disc formed body B is heated to 1000 ° C., only the carbon component C is left and the remaining impurities are burned. The combustible body V is burned out and removed, and the empty space in which the combustible body V rides becomes the cooling channel 113 (refer to FIG. 1).

The carbon-ceramic brake disc molded body (B) has a density of 1.0 to 1.7 g / cm 3 and a porosity of 50 vol% or less after carbonization.

Hereinafter, the ninth step S19 will be described in detail.

The carbon-ceramic brake disc carbide is placed on silicon powder.

In an inert gas atmosphere or vacuum atmosphere, heating is carried out to 1410 ° C. or more, which is the melting point of silicon. Silicon melts and infiltrates into the carbon-ceramic brake disc molded body (B).

Infiltrated silicon reacts with the remaining carbon components to form silicon carbide (SiC).

When silicon is melted and infiltrated into the carbon-ceramic brake disc molded body (B), the first friction layer 121 and the second friction layer 122 are composed of 75 wt% SiC, 24.5 wt% Si, and 0.5 wt% C. Has a ratio.

When silicon is melted and infiltrated into the carbon-ceramic brake disc molded body (B), the first body 111 and the second body 112 are made of SiC 25-50 wt%, Si 0-25 wt%, and C 30-60 wt. It has a composition ratio of%.

Since the first body 111, the second body 122, and the partition wall 130 are made from the first mixture X1, the composition ratio of the first body 111 and the components of the second body 112 are described. The adjustment ratio and the component composition ratio of the partition wall 130 are the same. Therefore, the partition wall 130 has a component composition ratio of SiC 25-50 wt%, Si 0-25 wt%, and C 30-60 wt%.

Hereinafter, a method of manufacturing a carbon-ceramic brake disc according to a second embodiment of the present invention will be described. 5 is a flowchart illustrating a method of manufacturing a carbon-ceramic brake disc according to a second embodiment of the present invention.

In the method of manufacturing the carbon-ceramic brake disc according to the second embodiment of the present invention, the partition wall 130 is formed by heating / pressing the first mixture X1 with a press P in which the partition wall is engraved. Instead, the partition wall 130 is formed by machining (Shaping and Planing) on the surface of the first body (111). The remainder is the same as the method for manufacturing the carbon-ceramic brake disc according to the first embodiment of the present invention, so description thereof is omitted.

As shown in FIG. 5, a method of manufacturing a carbon-ceramic brake disc according to a second embodiment of the present invention may be described as follows.

A first step (S31) of placing the first mixture (X1) in which carbon fibers and phenol resins are mixed into a molding mold (M); A second step (S32) of heating / pressing the first mixture (X1) with a press (P) to make the first body 111; A third step (S33) of making the partition wall 130 by machining on the surface of the first body 111; A fourth step S34 of filling the space S between the partition walls 130 with the second mixture X2 in which the carbon fibers and the phenol resin are mixed; A fifth step S35 of heating / pressing the second mixture X2 with a press P to form the first friction layer 121; A sixth step (S36) of removing the first carbon-ceramic brake disc molded body (B1) composed of the partition wall 130, the first body 111, and the first friction layer 121 from the forming mold M; By repeating the first step S31 to the sixth step S36, the second carbon-ceramic brake disc molded body B2 is made, and the second carbon-ceramic brake disc molded body B2 is taken out of the forming mold M. Seventh step (S37); The first carbon-ceramic brake disc molded body (B1), the combustible body (V) having the shape of the cooling channel 113, and the second carbon-ceramic brake disc molded body (B2) are formed in a mold (M). An eighth step (S38) of stacking the molds and heating / pressing with a press P to form a carbon-ceramic brake disc molded body B; A ninth step S39 of applying carbon to the carbon-ceramic brake disc molded body B and carbonizing the same; And a tenth step (S40) of melting and infiltrating silicon into the carbon-ceramic brake disc carbonized body formed by carbonization of the carbon-ceramic brake disc molded body (B) and polishing it.

1 is a perspective view showing a carbon-ceramic brake disc according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view II-II of FIG. 1.

3 is a flowchart illustrating a method of manufacturing a carbon-ceramic brake disc according to the first embodiment of the present invention.

4 (a) to 4 (m) are diagrams illustrating first to seventh steps of FIG. 3.

5 is a flowchart illustrating a method of manufacturing a carbon-ceramic brake disc according to a second embodiment of the present invention.

Claims (8)

A body consisting of a first body and a second body; A partition wall formed integrally with the first body and protruding from the surface of the first body; A first friction layer formed in a space between the partition walls protruding from the surface of the first body; A partition wall formed integrally with the second body and protruding from the surface of the second body; And And a second friction layer formed in a space between the partition walls protruding from the surface of the second body. The partition wall has the same composition ratio as the first body and the second body, The partition wall has a component composition ratio different from that of the first friction layer and the second friction layer, And the height of the partition wall is the same as the height of the first friction layer and the second friction layer. delete delete delete The carbon-ceramic brake disc of claim 1, wherein the surface area of the partition wall is within 10% of the total area of the first friction layer or the second friction layer. The inner wall of claim 1, wherein the partition wall comprises circular walls arranged in order of increasing diameter from the inner diameter of the first friction layer or the second friction layer toward the outer diameter. Carbon-ceramic brake discs consisting of straight walls extending radially outwardly at. A first step of putting a first mixture of carbon fibers and phenol resins into a mold; A second step of heating / pressurizing the first mixture with a press in which the shape of the partition wall is engraved on the bottom surface to form a first body and the partition wall; A third step of filling a space between the partition walls with a second mixture of carbon fibers and phenol resins; A fourth step of making the first friction layer by heating / pressing the second mixture with the press; A fifth step of removing the first carbon-ceramic brake disc formed body comprising the partition wall, the first body, and the first friction layer from the forming mold; A sixth step of making the second carbon-ceramic brake disc molded body by repeating the first to fifth steps, and taking out the second carbon-ceramic brake disc molded body from the mold; The first carbon-ceramic brake disc molded body, a combustible body having a shape of a cooling channel, and the second carbon-ceramic brake disc molded body are sequentially stacked on the mold, and heated / pressurized by the press to form a carbon-ceramic brake. A seventh step of making a disk molded body; An eighth step of applying carbon to the carbon-ceramic brake disc molded body to carbonize it; And And a ninth step of melting and infiltrating silicon into the carbon-ceramic brake disc carbonized body formed by carbonization of the carbon-ceramic brake disc molded body, followed by polishing. A first step of putting a first mixture of carbon fibers and phenol resins into a mold; A second step of heating / pressurizing the first mixture with a press to make a first body; A third step of making a partition wall by machining on the surface of the first body; A fourth step of filling a space between the partition walls with a second mixture of carbon fibers and phenol resins; A fifth step of heating / pressing the second mixture with the press to form a first friction layer; A sixth step of taking out the first carbon-ceramic brake disc formed body comprising the partition wall, the first body and the first friction layer from the forming mold; A seventh step of making the second carbon-ceramic brake disc molded body by repeating the first to sixth steps, and taking out the second carbon-ceramic brake disc molded body from the mold; The first carbon-ceramic brake disc molded body, a combustible body having a shape of a cooling channel, and the second carbon-ceramic brake disc molded body are sequentially stacked on the mold, and heated / pressurized by the press to form a carbon-ceramic brake. An eighth step of making a disk molded body; A ninth step of heating and carbonizing the carbon-ceramic brake disc molded body; And 10. A method of manufacturing a carbon-ceramic brake disc, comprising: a tenth step of melting and infiltrating silicon into a carbon-ceramic brake disc carbonized body formed by carbonization of the carbon-ceramic brake disc molded body.

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