Carbon-ceramic brake disc containing ventilation ducts and preparation method of carbon-ceramic brake disc

Abstract

The invention provides a carbon-ceramic brake disc containing ventilation ducts, the carbon-ceramic brake disc containing the ventilation ducts comprises an upper base body and a lower base body, a plurality of heat dissipation ducts are arranged at the joint of the upper base body and the lower base body, the heat dissipation ducts are evenly distributed in a circumferential mode, the upper base body and the lower base body are provided with a plurality of ventilation ducts, and the ventilation ducts are arranged on the upper base body and the lower base body. The ventilation hole channels penetrate through the upper base body or the lower base body and are communicated with the heat dissipation hole channels. The carbon-ceramic brake disc is provided with heat dissipation ducts and ventilation ducts, and the relation between the area of the inner surfaces of the ventilation ducts and the area of the side wall faces of the heat dissipation ducts and the relation between the sum of the areas of the ventilation ducts and the size of the carbon-ceramic brake disc are limited, so that the arrangement reasonability of the heat dissipation ducts and the ventilation ducts is improved; and the heat dissipation effect on the carbon-ceramic brake disc due to the cooperation of the two is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of brake disc manufacturing, and in particular to a carbon-ceramic brake disc containing ventilation channels and a preparation method thereof. Background Art

[0002] The brake disc is an important component installed on vehicles such as cars and motorcycles, used to brake the vehicle. It is usually located between the wheels and works with the brake calipers, brake pads, etc. in the brake system. The brake disc mainly plays the role of deceleration or emergency stop during the operation of the car. It is related to human life safety in emergencies, so it is particularly important. At present, carbon ceramic brake discs are made of carbon fiber reinforced silicon carbide materials, but carbon fiber is not resistant to high temperature oxidation in the air, and it is easy to have large fluctuations in the friction coefficient at high temperatures. At present, ventilation channels are often set in the center of the brake disc to increase the heat exchange capacity of the brake disc and thus reduce the temperature. The brake heat generated during braking is mainly dissipated through the ventilation structure of the brake disc, but some of the brake heat still causes the surface temperature of the brake disc to rise sharply, greatly reducing the wear resistance of the brake disc, and reducing the braking performance of the moving vehicle, inducing safety hazards in automobile braking. If the ventilation channel design is unreasonable, it is very easy to have problems such as poor heat exchange capacity and high surface temperature of the brake disc.

[0003] In this regard, a carbon-ceramic brake disc with ventilation holes is proposed, which defines the relationship between the side areas of the ventilation holes and the heat dissipation holes, as well as the relationship between the sum of their areas and the volume of the brake disc, so that the brake disc has a better heat dissipation effect. Summary of the invention

[0004] The purpose of the present invention is to provide a carbon-ceramic brake disc with ventilation holes, which provide ventilation holes and heat dissipation holes to cooperate with each other to improve the heat dissipation capacity of the brake disc, and at the same time propose a relationship between the areas of the ventilation holes and the heat dissipation holes, optimize the ratio and further improve the heat dissipation effect of the brake disc.

[0005] To achieve this purpose, the present invention provides a carbon ceramic brake disc with ventilation holes, the carbon ceramic brake disc with ventilation holes comprises an upper substrate and a lower substrate, the upper substrate and the lower substrate are fixed as a whole. A plurality of heat dissipation holes are provided at the connection between the upper substrate and the lower substrate, the heat dissipation holes are evenly distributed in a circle, a plurality of ventilation holes are provided on the upper substrate and the lower substrate, the ventilation holes penetrate the upper substrate or the lower substrate and are connected to the heat dissipation holes; the total area of ​​the inner surface of the ventilation hole is S t The total area of ​​the side wall of the heat dissipation channel is S S The total volume of the carbon ceramic brake disc containing ventilation holes is V, which satisfies the following formula:

[0006] 3S t <S s

[0007] a*V<(S s +S t )

[0008] Where a is a coefficient, and its magnitude is 10 / mm.

[0009] Preferably, the openings connecting the ventilation duct and the carbon ceramic brake disc surface containing the ventilation duct are surface ventilation openings, and the area of ​​each surface ventilation opening is 5-50mm 2 .

[0010] Preferably, the ventilation holes and the openings connected to the heat dissipation holes are internal ventilation openings, and the area of ​​each internal ventilation opening is 3-40 mm 2 .

[0011] Preferably, the area of ​​the surface ventilation apertures is larger than the area of ​​the internal ventilation apertures.

[0012] Preferably, the ventilation duct extends from the carbon-ceramic brake disc surface containing the ventilation duct to the heat dissipation duct and forms a predetermined angle with the carbon-ceramic brake disc surface containing the ventilation duct.

[0013] Preferably, the angle is 45-90°.

[0014] The present invention also provides a method for preparing a carbon-ceramic brake disc containing ventilation holes, which is used to prepare the above-mentioned carbon-ceramic brake disc containing ventilation holes. The preparation method is as follows:

[0015] S1: preparing a carbon fiber preform of a predetermined thickness;

[0016] S2: placing the carbon fiber preform into a CVI furnace for vapor deposition at a deposition temperature of 900-1100° C. for 150-300 h to obtain a CVI blank, with a methane flow rate of 80-180 L / h and a nitrogen flow rate of 3-20 L / h;

[0017] S3: Mechanically process the CVI blank to obtain a brake disc blank, wherein the brake disc blank comprises an upper substrate and a lower substrate, and a predetermined number of ventilation channels and heat dissipation channels are distributed and processed on the surface and side of the brake disc blank;

[0018] S4: placing the brake disc blank into a boron nitride crucible and placing the boron nitride crucible and the brake disc blank into a vacuum furnace for siliconizing treatment to obtain a siliconized blank;

[0019] S5: performing surface grinding and outer contour dimension processing on the siliconized blank to obtain a carbon ceramic brake disc containing ventilation ducts.

[0020] Preferably, the method for preparing the carbon fiber preform is as follows: stacking the carbon fiber unidirectional cloth and the carbon fiber mesh as a unit layer, wherein the carbon fiber directions of the carbon fiber unidirectional cloths of two adjacent unit layers are at an angle of 90°, and after stacking one unit, acupuncture the sample, and repeatedly stacking the unit layers to obtain a carbon fiber preform of a desired thickness, wherein the acupuncture density is 50-200 needles / cm 2 .

[0021] Preferably, pure silicon powder having a mass 1.1 times that of the brake disc blank is pre-added into the boron nitride crucible.

[0022] Preferably, the siliconizing treatment temperature is 1600-1700°C, the holding time is 2-4h, and the furnace pressure is less than 1000Pa.

[0023] Beneficial effect: The carbon-ceramic brake disc with ventilation ducts provided by the present invention improves the rationality of the setting of the heat dissipation ducts and ventilation ducts by setting the heat dissipation ducts and ventilation ducts on the carbon-ceramic brake disc, and limits the relationship between the inner surface of the ventilation duct and the area of ​​the side wall of the heat dissipation duct, as well as the relationship between the sum of the areas of the two and the volume of the carbon-ceramic brake disc, so as to further improve the heat dissipation effect of the two on the carbon-ceramic brake disc. At the same time, the ventilation ducts are set in a form with different sizes at both ends, and the area of ​​the surface ventilation duct opening is larger than the area of ​​the internal ventilation duct opening, which increases the flow of external air to the ventilation duct, improves the gas flow and flow rate in the heat dissipation duct, and further improves the heat dissipation capacity of the carbon-ceramic brake disc. In addition, the present invention also proposes a preparation method of a carbon-ceramic brake disc with ventilation ducts, firstly using carbon fiber mesh tires and carbon fiber unidirectional cloths to overlap and needle-punch and perform vapor deposition treatment to obtain a CVI blank, and then using mechanical processing to prepare the heat dissipation ducts and ventilation ducts with predetermined settings, and then siliconizing and polishing to obtain the product, the whole preparation process is simple, and the operation method is simple and easy to produce. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The figure is a schematic diagram of the structure of the carbon-ceramic brake disc with ventilation holes according to the present invention.

[0025] Figure 2 The bottom view of the carbon-ceramic brake disc with ventilation holes of the present invention is shown.

[0026] In the figure: 1-upper substrate, 2-lower substrate, 3-ventilation channel, 4-heat dissipation channel. DETAILED DESCRIPTION

[0027] The embodiments described below are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] refer to Figure 1 and Figure 2 The present invention provides a carbon ceramic brake disc with ventilation holes, the carbon ceramic brake disc with ventilation holes comprises an upper substrate 1 and a lower substrate 2, the upper substrate 1 and the lower substrate 2 are fixed as a whole. A plurality of heat dissipation holes 4 are provided at the connection between the upper substrate 1 and the lower substrate 2, the heat dissipation holes 4 are evenly distributed in a circle, a plurality of ventilation holes 3 are provided on the upper substrate 1 and the lower substrate 2, the ventilation holes 3 penetrate the upper substrate 1 or the lower substrate 2 and are connected to the heat dissipation holes 4; the total area of ​​the inner surface of the ventilation holes 3 is S t The total area of ​​the side wall of the heat dissipation channel 4 is S S The total volume of the carbon ceramic brake disc containing ventilation holes is V, which satisfies the following formula:

[0029] 3S t <S s

[0030] a*V<(S s +S t )

[0031] Where a is a coefficient, and its magnitude is 10 / mm.

[0032] The openings connecting the ventilation duct 3 and the carbon ceramic brake disc surface containing the ventilation duct are surface ventilation openings, and the area of ​​each surface ventilation opening is 5-50mm. 2 .

[0033] The openings of the ventilation channel 3 and the heat dissipation channel 4 are internal ventilation openings, and the area of ​​each internal ventilation opening is 3-40mm 2 .

[0034] The surface ventilation apertures have an area greater than an area of ​​the interior ventilation apertures.

[0035] The ventilation duct extends from the carbon-ceramic brake disc surface containing the ventilation duct to the heat dissipation duct and forms a predetermined angle with the carbon-ceramic brake disc surface containing the ventilation duct.

[0036] The angle is 45-90°.

[0037] The present invention also provides a method for preparing a carbon ceramic brake disc containing ventilation holes, and the preparation method is as follows:

[0038] S1: preparing a carbon fiber preform of a predetermined thickness;

[0039] S2: placing the carbon fiber preform into a CVI furnace for vapor deposition at a deposition temperature of 900-1100° C. for 150-300 h to obtain a CVI blank, with a methane flow rate of 80-180 L / h and a nitrogen flow rate of 3-20 L / h;

[0040] S3: Mechanically process the CVI blank to obtain a brake disc blank, wherein the brake disc blank comprises an upper substrate and a lower substrate, and a predetermined number of ventilation channels and heat dissipation channels are distributed and processed on the surface and side of the brake disc blank;

[0041] S4: placing the brake disc blank into a boron nitride crucible and placing the boron nitride crucible and the brake disc blank into a vacuum furnace for siliconizing treatment to obtain a siliconized blank;

[0042] S5: performing surface grinding and outer contour dimension processing on the siliconized blank to obtain a carbon ceramic brake disc containing ventilation ducts.

[0043] The method for preparing the carbon fiber preform is as follows: stacking the carbon fiber unidirectional cloth and the carbon fiber mesh as a unit layer, wherein the carbon fiber directions of the carbon fiber unidirectional cloths of two adjacent unit layers are at an angle of 90°, and after stacking one unit, acupuncture the sample, and repeatedly stacking the unit layers to obtain a carbon fiber preform of a desired thickness, wherein the acupuncture density is 50-200 needles / cm 2 .

[0044] Pure silicon powder having a mass 1.1 times that of the brake disc blank is pre-added into the boron nitride crucible.

[0045] The siliconizing treatment temperature is 1600-1700°C, the insulation time is 2-4h, and the furnace pressure is less than 1000Pa.

[0046] Example 1

[0047] This embodiment provides a carbon-ceramic brake disc with ventilation holes, and the preparation steps are as follows:

[0048] S1: The carbon fiber unidirectional cloth and the carbon fiber mesh are stacked as a unit layer, wherein the carbon fiber directions of the carbon fiber unidirectional cloths of two adjacent unit layers are at a 90° angle. After stacking one unit, the sample is needle-punched, and the unit layers are repeatedly stacked to obtain a carbon fiber preform of the desired thickness. The needle-punching density is 150 needles / cm 2 ;

[0049] S2: placing the carbon fiber preform into a CVI furnace for vapor deposition at a deposition temperature of 1000° C. for 200 h to obtain a CVI blank, with a methane flow rate of 100 L / h and a nitrogen flow rate of 8 L / h;

[0050] S3: Mechanically process the CVI blank to obtain a brake disc blank, the brake disc blank comprising an upper substrate and a lower substrate, and a predetermined number of ventilation channels and heat dissipation channels are distributed and processed on the surface and side of the brake disc blank, and the surface ventilation hole area of ​​a single hole of the ventilation channel is 12.5mm 2 , the internal ventilation opening area is 9mm 2 The sum of the side areas of the heat dissipation channels after processing is 4 times the sum of the side areas of the ventilation channels, the sum of the side areas of the heat dissipation channels and the ventilation channels is 14 times the volume of the brake disc blank, and the angle between the ventilation channels and the plane of the brake disc blank is 90°;

[0051] S4: After the brake disc blank is placed in a boron nitride crucible, the boron nitride crucible and the brake disc blank are placed in a vacuum furnace for siliconizing treatment to obtain a siliconized blank. Pure silicon powder 1.1 times the mass of the brake disc blank is pre-added in the boron nitride crucible. The siliconizing treatment temperature is 1650° C., the holding time is 2 hours, and the furnace pressure is less than 1000 Pa.

[0052] S5: performing surface grinding and outer contour dimension processing on the siliconized blank to obtain a carbon ceramic brake disc containing ventilation ducts.

[0053] Example 2

[0054] This embodiment provides a carbon-ceramic brake disc with ventilation holes, and the preparation steps are as follows:

[0055] S1: The carbon fiber unidirectional cloth and the carbon fiber mesh are stacked as a unit layer, wherein the carbon fiber directions of the carbon fiber unidirectional cloths of two adjacent unit layers are at a 90° angle. After stacking one unit, the sample is needle-punched, and the unit layers are repeatedly stacked to obtain a carbon fiber preform of the desired thickness. The needle-punching density is 150 needles / cm 2 ;

[0056] S2: placing the carbon fiber preform into a CVI furnace for vapor deposition at a deposition temperature of 1000° C. for 200 h to obtain a CVI blank, with a methane flow rate of 100 L / h and a nitrogen flow rate of 8 L / h;

[0057] S3: Mechanically process the CVI blank to obtain a brake disc blank, the brake disc blank comprising an upper substrate and a lower substrate, and distribute a predetermined number of ventilation channels and heat dissipation channels on the surface and side of the brake disc blank, wherein the surface ventilation hole area of ​​a single hole of the ventilation channel is 20 mm 2 , the internal ventilation opening area is 15mm 2The sum of the side areas of the heat dissipation channels after processing is 4 times the sum of the side areas of the ventilation channels, the sum of the side areas of the heat dissipation channels and the ventilation channels is 14 times the volume of the brake disc blank, and the angle between the ventilation channels and the plane of the brake disc blank is 90°;

[0058] S4: After the brake disc blank is placed in a boron nitride crucible, the boron nitride crucible and the brake disc blank are placed in a vacuum furnace for siliconizing treatment to obtain a siliconized blank. Pure silicon powder 1.1 times the mass of the brake disc blank is pre-added in the boron nitride crucible. The siliconizing treatment temperature is 1650° C., the holding time is 2 hours, and the furnace pressure is less than 1000 Pa.

[0059] S5: performing surface grinding and outer contour dimension processing on the siliconized blank to obtain a carbon ceramic brake disc containing ventilation ducts.

[0060] Example 3

[0061] S1: The carbon fiber unidirectional cloth and the carbon fiber mesh are stacked as a unit layer, wherein the carbon fiber directions of the carbon fiber unidirectional cloths of two adjacent unit layers are at a 90° angle. After stacking one unit, the sample is needle-punched, and the unit layers are repeatedly stacked to obtain a carbon fiber preform of the desired thickness. The needle-punching density is 150 needles / cm 2 ;

[0062] S2: placing the carbon fiber preform into a CVI furnace for vapor deposition at a deposition temperature of 1000° C. for 200 h to obtain a CVI blank, with a methane flow rate of 100 L / h and a nitrogen flow rate of 8 L / h;

[0063] S3: Mechanically process the CVI blank to obtain a brake disc blank, the brake disc blank comprising an upper substrate and a lower substrate, and distribute a predetermined number of ventilation channels and heat dissipation channels on the surface and side of the brake disc blank, wherein the surface ventilation hole area of ​​a single hole of the ventilation channel is 12.5 mm 2 , the internal ventilation opening area is 9mm 2 The sum of the side areas of the heat dissipation channels after processing is 4 times the sum of the side areas of the ventilation channels, the sum of the side areas of the heat dissipation channels and the ventilation channels is 14 times the volume of the brake disc blank, and the angle between the ventilation channels and the plane of the brake disc blank is 85°;

[0064] S4: After the brake disc blank is placed in a boron nitride crucible, the boron nitride crucible and the brake disc blank are placed in a vacuum furnace for siliconizing treatment to obtain a siliconized blank. Pure silicon powder 1.1 times the mass of the brake disc blank is pre-added in the boron nitride crucible. The siliconizing treatment temperature is 1650° C., the holding time is 2 hours, and the furnace pressure is less than 1000 Pa.

[0065] S5: performing surface grinding and outer contour dimension processing on the siliconized blank to obtain a carbon ceramic brake disc containing ventilation ducts.

[0066] Example 4

[0067] S1: The carbon fiber unidirectional cloth and the carbon fiber mesh are stacked as a unit layer, wherein the carbon fiber directions of the carbon fiber unidirectional cloths of two adjacent unit layers are at a 90° angle. After stacking one unit, the sample is needle-punched, and the unit layers are repeatedly stacked to obtain a carbon fiber preform of the desired thickness. The needle-punching density is 150 needles / cm 2 ;

[0068] S2: placing the carbon fiber preform into a CVI furnace for vapor deposition at a deposition temperature of 1000° C. for 200 h to obtain a CVI blank, with a methane flow rate of 100 L / h and a nitrogen flow rate of 8 L / h;

[0069] S3: Mechanically process the CVI blank to obtain a brake disc blank, the brake disc blank comprising an upper substrate and a lower substrate, and distribute a predetermined number of ventilation channels and heat dissipation channels on the surface and side of the brake disc blank, wherein the surface ventilation hole area of ​​a single hole of the ventilation channel is 12.5 mm 2 , the internal ventilation opening area is 9mm 2 The sum of the side areas of the heat dissipation channels after processing is 4 times the sum of the side areas of the ventilation channels, the sum of the side areas of the heat dissipation channels and the ventilation channels is 14 times the volume of the brake disc blank, and the angle between the ventilation channels and the plane of the brake disc blank is 45°;

[0070] S4: After the brake disc blank is placed in a boron nitride crucible, the boron nitride crucible and the brake disc blank are placed in a vacuum furnace for siliconizing treatment to obtain a siliconized blank. Pure silicon powder 1.1 times the mass of the brake disc blank is pre-added in the boron nitride crucible. The siliconizing treatment temperature is 1650° C., the holding time is 2 hours, and the furnace pressure is less than 1000 Pa.

[0071] S5: performing surface grinding and outer contour dimension processing on the siliconized blank to obtain a carbon ceramic brake disc containing ventilation ducts.

[0072] Comparative Example 1

[0073] This comparative example provides a carbon ceramic brake disc containing ventilation holes, and the preparation steps are as follows:

[0074] S1: The carbon fiber unidirectional cloth and the carbon fiber mesh are stacked as a unit layer, wherein the carbon fiber directions of the carbon fiber unidirectional cloths of two adjacent unit layers are at a 90° angle. After stacking one unit, the sample is needle-punched, and the unit layers are repeatedly stacked to obtain a carbon fiber preform of the desired thickness. The needle-punching density is 150 needles / cm2 ;

[0075] S2: placing the carbon fiber preform into a CVI furnace for vapor deposition at a deposition temperature of 1000° C. for 200 h to obtain a CVI blank, with a methane flow rate of 100 L / h and a nitrogen flow rate of 8 L / h;

[0076] S3: Mechanically process the CVI blank to obtain a brake disc blank, the brake disc blank comprising an upper substrate and a lower substrate, and distribute a predetermined number of ventilation channels and heat dissipation channels on the surface and side of the brake disc blank, wherein the surface ventilation hole area of ​​a single hole of the ventilation channel is 12.5 mm 2 , the internal ventilation opening area is 12.5mm 2 The sum of the side areas of the heat dissipation channels after processing is 4 times the sum of the side areas of the ventilation channels, the sum of the side areas of the heat dissipation channels and the ventilation channels is 8 times the volume of the brake disc blank, and the angle between the ventilation channels and the plane of the brake disc blank is 90°;

[0077] S4: After the brake disc blank is placed in a boron nitride crucible, the boron nitride crucible and the brake disc blank are placed in a vacuum furnace for siliconizing treatment to obtain a siliconized blank. Pure silicon powder 1.1 times the mass of the brake disc blank is pre-added in the boron nitride crucible. The siliconizing treatment temperature is 1650° C., the holding time is 2 hours, and the furnace pressure is less than 1000 Pa.

[0078] S5: performing surface grinding and outer contour dimension processing on the siliconized blank to obtain a carbon ceramic brake disc containing ventilation ducts.

[0079] Comparative Example 2

[0080] This comparative example provides a carbon ceramic brake disc containing ventilation holes, and the preparation steps are as follows:

[0081] S1: The carbon fiber unidirectional cloth and the carbon fiber mesh are stacked as a unit layer, wherein the carbon fiber directions of the carbon fiber unidirectional cloths of two adjacent unit layers are at a 90° angle. After stacking one unit, the sample is needle-punched, and the unit layers are repeatedly stacked to obtain a carbon fiber preform of the desired thickness. The needle-punching density is 150 needles / cm 2 ;

[0082] S2: placing the carbon fiber preform into a CVI furnace for vapor deposition at a deposition temperature of 1000° C. for 200 h to obtain a CVI blank, with a methane flow rate of 100 L / h and a nitrogen flow rate of 8 L / h;

[0083] S3: Mechanically process the CVI blank to obtain a brake disc blank, the brake disc blank comprising an upper substrate and a lower substrate, and distribute a predetermined number of ventilation channels and heat dissipation channels on the surface and side of the brake disc blank, wherein the surface ventilation hole area of ​​a single hole of the ventilation channel is 12.5 mm 2 , the internal ventilation opening area is 12.5mm 2 The sum of the side areas of the heat dissipation channels after processing is twice the sum of the side areas of the ventilation channels, the sum of the side areas of the heat dissipation channels and the ventilation channels is 8 times the volume of the brake disc blank, and the angle between the ventilation channels and the plane of the brake disc blank is 90°;

[0084] S4: After the brake disc blank is placed in a boron nitride crucible, the boron nitride crucible and the brake disc blank are placed in a vacuum furnace for siliconizing treatment to obtain a siliconized blank. Pure silicon powder 1.1 times the mass of the brake disc blank is pre-added in the boron nitride crucible. The siliconizing treatment temperature is 1650° C., the holding time is 2 hours, and the furnace pressure is less than 1000 Pa.

[0085] S5: performing surface grinding and outer contour dimension processing on the siliconized blank to obtain a carbon ceramic brake disc containing ventilation ducts.

[0086] The carbon ceramic brake discs with ventilation holes prepared in the above-mentioned Examples 1-4 and Comparative Examples 1-2 were tested. The test method is:

[0087] Disc surface temperature: Tested in accordance with the medium and high load test method of GB / T 34422-2017, the temperature is the highest temperature during the test. Disc surface temperature test position is tested in accordance with the temperature measurement method A.2.6 of the national standard

[0088] The test data is shown in Table 1.

[0089] Table 1 Test data of carbon ceramic brake discs with ventilation ducts in Examples 1-4 and Comparative Examples 1-2

[0090]

[0091] From the above test data, it can be seen that in Example 1, the relationship between the side area of ​​the ventilation duct and the heat dissipation duct, as well as the relationship between the sum of their areas and the volume of the brake disc are reasonably designed. During the test, the surface temperature of the brake disc was relatively low, at 620°C. In Example 2, the areas at both ends of the ventilation duct were increased, the air volume was increased, and the temperature of the brake disc surface was further reduced. In Example 3, the angle formed by the ventilation duct and the disc surface is 85°, which makes it easier for air to enter when the brake disc rotates, and the disc surface temperature is reduced compared with Example 1.

[0092] In Comparative Example 1, the ratio of the sum of the side area of ​​the heat dissipation channel and the side area of ​​the ventilation channel to the volume of the brake disc body decreases. For a disc body of the same volume, the reduction in the heat dissipation area leads to an increase in the temperature of the disc surface, and the inner and outer opening areas of the ventilation holes are the same, making it more difficult for air to enter. Therefore, the temperature of this solution reaches 710°C, indicating that the heat dissipation effect is not good. Comparative Example 2 increases the ratio of the side area of ​​the ventilation channel on the basis of Comparative Example 1. In Claim 1, the ratio is 3. When the ratio is less than this value, the heat of the disc surface brought out by the ventilation channel is already greater than the heat that can be dissipated by the heat dissipation channel. The increased side area of ​​the ventilation channel has little effect on reducing the temperature. On the contrary, the loss of the base volume reduces the overall strength of the brake disc to a certain extent.

[0093] The above disclosures are only several preferred embodiments of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A carbon-ceramic brake disc with ventilation holes, the carbon-ceramic brake disc with ventilation holes comprising an upper substrate and a lower substrate, the upper substrate and the lower substrate are fixed as one body, characterized in that: A plurality of heat dissipation channels are provided at the connection between the upper substrate and the lower substrate, and the heat dissipation channels are evenly distributed in a circumference. A plurality of ventilation channels are provided on the upper substrate and the lower substrate, and the ventilation channels penetrate the upper substrate or the lower substrate and are connected to the heat dissipation channels; the total area of ​​the inner surface of the ventilation channel is S t The total area of ​​the side wall of the heat dissipation channel is S S The total volume of the carbon ceramic brake disc containing ventilation holes is V, which satisfies the following formula: 3S t <S s a*V<(S s +S t ) Where a is a coefficient, and its magnitude is 10 / mm.

2. The carbon-ceramic brake disc with ventilation holes as claimed in claim 1, characterized in that: The openings connecting the ventilation duct and the carbon ceramic brake disc surface containing the ventilation duct are surface ventilation openings, and the area of ​​each surface ventilation opening is 5-50mm 2 .

3. The carbon-ceramic brake disc with ventilation holes as claimed in claim 2, characterized in that: The ventilation holes and the openings connected to the heat dissipation holes are internal ventilation openings, and the area of ​​each internal ventilation opening is 3-40mm 2 .

4. The carbon-ceramic brake disc with ventilation holes as claimed in claim 3, characterized in that: The surface ventilation apertures have an area greater than an area of ​​the interior ventilation apertures.

5. The carbon-ceramic brake disc with ventilation holes as claimed in claim 1, characterized in that: The ventilation duct extends from the carbon-ceramic brake disc surface containing the ventilation duct to the heat dissipation duct and forms a predetermined angle with the carbon-ceramic brake disc surface containing the ventilation duct.

6. The carbon-ceramic brake disc with ventilation holes as claimed in claim 5, characterized in that: The angle is 45-90°.

7. A method for preparing a carbon-ceramic brake disc containing ventilation holes, used for preparing a carbon-ceramic brake disc containing ventilation holes as claimed in any one of claims 1 to 6, characterized in that: The preparation method is as follows: S1: preparing a carbon fiber preform of a predetermined thickness; S2: placing the carbon fiber preform into a CVI furnace for vapor deposition at a deposition temperature of 900-1100° C. for 150-300 h to obtain a CVI blank, with a methane flow rate of 80-180 L / h and a nitrogen flow rate of 3-20 L / h; S3: Mechanically process the CVI blank to obtain a brake disc blank, wherein the brake disc blank comprises an upper substrate and a lower substrate, and a predetermined number of ventilation channels and heat dissipation channels are distributed and processed on the surface and side of the brake disc blank; S4: placing the brake disc blank into a boron nitride crucible and placing the boron nitride crucible and the brake disc blank into a vacuum furnace for siliconizing treatment to obtain a siliconized blank; S5: performing surface grinding and outer contour dimension processing on the siliconized blank to obtain a carbon ceramic brake disc containing ventilation ducts.

8. The method for preparing a carbon-ceramic brake disc with ventilation holes according to claim 7, characterized in that: The method for preparing the carbon fiber preform comprises: stacking the carbon fiber unidirectional cloth and the carbon fiber web as a unit layer, wherein the carbon fiber directions of the carbon fiber unidirectional cloth of two adjacent unit layers are at an angle of 90 degrees, and after stacking one unit, acupuncture is performed on the sample, and the unit layers are repeatedly stacked to obtain a carbon fiber preform of a desired thickness, wherein the acupuncture density is 50-200 needles / cm 2 .

9. The method for preparing a carbon-ceramic brake disc with ventilation holes according to claim 7, characterized in that: Pure silicon powder having a mass 1.1 times that of the brake disc blank is pre-added into the boron nitride crucible.

10. The method for preparing a carbon-ceramic brake disc with ventilation holes according to claim 7, characterized in that: The siliconizing treatment temperature is 1600-1700°C, the holding time is 2-4h, and the furnace pressure is less than 1000Pa.

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