Low noise automobile brake material and its preparation method

Abstract

The present application relates to a kind of low noise automobile brake materials and its preparation method, it has the gradient distribution structure of porous material with the correlation of sound wave wavelength and noise reduction sound absorption backboard composition, the porous material with the correlation of sound wave wavelength is obtained after using rice hull, clam shell and diatom ball are mixed, microwave-assisted drying and vacuum heating.Optimal feature is to use environmental protection component, realize the batch production of low cost, low noise, high performance brake material by simple production process method.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobile brake materials, in particular to a low-noise automobile brake material and a preparation method thereof. BACKGROUND

[0002] Currently, automobile brake pads are mostly organic-based semi-metallic, little metallic, non-metallic friction materials, and a small amount of ceramic friction materials (including metal ceramic and non-metal ceramic). Organic-based friction materials are composed of three parts: base material (organic binder), reinforcing fiber, and filler (containing friction performance modifier). The base material is phenolic resin, modified phenolic resin, rubber, or their mixture. Organic brake materials have the advantages of low cost, simple manufacturing process, low noise, and not easy to damage the counterpart, but due to the high content of organic matter (15-25%), the organic brake material has the disadvantages of poor braking effect and rapid wear of the brake material due to the increase of friction coefficient decay at high temperature. SUMMARY

[0003] In order to solve the above technical problems, the present application provides a low-noise automobile brake material and a preparation method thereof, which has a clever formula, low cost, simple manufacturing process, and low noise.

[0004] The technical scheme of the present application is as follows:

[0005] The low-noise automobile brake material and the preparation method thereof have a porous material gradient distribution structure related to the wavelength of sound waves and a noise reduction sound absorption backboard. The porous material related to the wavelength of sound waves is obtained by mixing rice husk, clam shell, and diatom ball, microwave-assisted drying, and vacuum heating. The mass percentage of rice husk, clam shell, and diatom ball is 15%-28%, 32%-40%, and 40%-60%, respectively.

[0006] The preparation method of the porous material related to the wavelength of sound waves is as follows: the raw materials with a particle diameter of 15mm-25mm are mixed according to the mass percentage, and then subjected to preliminary high-temperature treatment using a microwave-assisted drying device, with a treatment time of 30 seconds-600 seconds. The treatment process is carried out in a reducing atmosphere, and the microwave power density during the treatment process is 50W / kg-300W / kg. After microwave-assisted treatment, the mixed particles are placed in a vacuum environment with a vacuum degree of 7x10-2Pa-10Pa, and heated at 1250℃-1600℃ for 30 minutes-90 minutes, and then cooled to room temperature.

[0007] The ratio of the pore volume of the porous material related to the wavelength of sound waves to the total volume is 35%-65%, and the pore diameter is 8.5mm-12.5mm.

[0008] The noise reduction sound absorption backboard has sound absorption noise reduction holes with geometric centers distributed along involutes, and the involute equation is:

[0009] x=r*cos(theta)+r*rad(theta)*sin(theta);

[0010] y=r*sin(theta)-r*rad(theta)*cos(theta);

[0011] z=0;

[0012] Wherein r is the diameter of the circumscribed circle of the sound absorption hole, 10mm≤r≤12.5mm;

[0013] The edge distance of the sound absorption hole is ≥7.5mm, the distance between the edge of the sound absorption hole and the edge of the backboard is ≥15mm, the center of the sound absorption hole is distributed along the involute, and the center distance of the sound absorption hole satisfies L=(N+1)*k*r, wherein k is a structure coefficient, (1.1-1.25), and the circumscribed circle diameter of the sound absorption hole is rN=(N+1)*k*r.

[0014] The sound absorption noise reduction hole has a positive 13-polygon outer contour line, a phenolic resin sound absorption pad in the contour, a sound absorption pad thickness consistent with the backboard, an outer contour consistent with the sound absorption noise reduction hole inner contour, and a circular inner contour with a diameter of 12.5mm-15mm.

[0015] The porous material is mixed with braking material components such as silica, carbon fiber, asbestos resin and other components to form a mixed raw material, then the backboard is filled with the mixed raw material in a forming mold, the mixed material is pressed in a direction, the pressing pressure is applied to the mold at the same time, the vibration frequency is applied to the mold, the holding time is applied to the mold, then the mold temperature is raised to the holding time, and finally the mold is demolded to complete the preparation.

[0016] The advantages of the present application are that the environmentally friendly components are used, the batch production of low-cost, low-noise and high-performance braking materials is realized through a simple production process, and the batch production of low-cost, low-noise and high-performance braking materials is realized. DETAILED DESCRIPTION

[0017] The following examples are described below:

[0018] A low-noise automotive braking material and its preparation method are disclosed. The material comprises a porous material gradient distribution structure correlated with sound wave wavelength and a noise-reducing and sound-absorbing backplate. The porous material correlated with sound wave wavelength is obtained by mixing rice husks, clam shells, and diatomaceous earth balls, followed by microwave-assisted drying and vacuum heating. The mass percentages of rice husks, clam shells, and diatomaceous earth balls are 15%-28%, 32%-40%, and 40%-60%, respectively. The preparation method of the porous material correlated with sound wave wavelength involves... Raw materials with a diameter of 15mm-25mm, mixed according to a mass percentage, undergo preliminary high-temperature treatment using a microwave-assisted drying device for 30-600 seconds. The treatment is carried out under a reducing atmosphere, with a microwave power density of 50W / kg-300W / kg. After microwave-assisted treatment, the mixed particles are placed in a vacuum environment of 7x10⁻²Pa-10Pa and held at 1250℃-1600℃ for 30-90 minutes, followed by cooling to room temperature. The porous material, exhibiting a relationship with sound wave wavelength, has a pore volume ratio of 35%-65% in its total volume, with a pore diameter of 8.5mm-12.5mm. The noise-reducing and sound-absorbing back panel, originating from its geometric center, has sound-absorbing and noise-reducing holes distributed along an involute curve. The involute equation is:

[0019] x=r*cos(θ)+r*rad(θ)*sin(θ);

[0020] y=r*sin(θ)-r*rad(θ)*cos(θ);

[0021] z=0;

[0022] Where r is the diameter of the circumscribed circle of the central sound-absorbing hole, 10mm≤r≤12.5mm; the distance between the edges of the sound-absorbing holes is ≥7.5mm, the distance between the edge of the sound-absorbing hole and the edge of the back panel is ≥15mm, the center of the sound-absorbing holes is distributed along the involute, and the distance between the center of the sound-absorbing holes satisfies L=(N+1)*k*r, where k is the structural coefficient, (1.1-1.25), and the diameter of the circumscribed circle of the sound-absorbing hole is rN=(N+1)*k*r.

[0023] The sound-absorbing and noise-reducing hole has an outer contour of a regular 13-sided polygon, with a phenolic resin sound-absorbing pad inside the contour. The thickness of the sound-absorbing pad is the same as that of the back plate. The outer contour is consistent with the inner contour of the sound-absorbing and noise-reducing hole, and the inner contour is circular with a diameter of 12.5mm-15mm.

[0024] First, the porous material is mixed with other components of the brake material, such as silica, carbon fiber, and asbestos resin to form a mixture. Then, the back plate and the mixture are filled into a forming mold, and the mixture is pressed. The pressing pressure is applied, and at the same time, high-frequency vibration is applied to the mold. The vibration frequency, holding time, and mold temperature are adjusted, and the mold is kept at the adjusted temperature for a certain period of time. Finally, the mold is opened, and the brake material is prepared.

Claims

1. A method for producing a low noise automotive brake material, characterized by, It has the gradient distribution structure of the porous material related to the wavelength of sound wave and the noise reduction sound absorption backboard group, the porous material related to the wavelength of sound wave is obtained by mixing rice husk, clam shell and diatom ball, microwave assisted drying and vacuum heating, wherein the mass percentage of rice husk, clam shell and diatom ball is 15%-28%, 32%-40% and 40%-60% respectively, the ratio of the pore volume of the porous material related to the wavelength of sound wave in the total volume is 35%-65%, and the pore distribution diameter is 8.5mm-12.5mm, the noise reduction sound absorption backboard has sound absorption noise reduction holes distributed along the involute with the geometric center as the starting point, the involute equation is: x=r*cos(θ)+r*rad(θ)*sin(θ); y=r*sin(θ)-r*rad(θ)*cos(θ); z=0； Wherein r is the diameter of the circumscribed circle of the sound absorption hole, 10mm≤r≤12.5mm; The edge distance of the sound absorption hole is greater than or equal to 7.5mm, the distance between the edge of the sound absorption hole and the edge of the backboard is greater than or equal to 15mm, the center of the sound absorption hole is distributed along the involute, the center distance of the sound absorption hole satisfies L=(N+1)*k*r, wherein k is the structure coefficient, (1.1-1.25), the circumscribed circle diameter of the sound absorption hole is rN=(N+1)*k*r; The method for preparing the porous material with a correlation with the wavelength of the sound wave comprises the following steps: preliminarily treating raw materials with a particle diameter of 15-25 mm and mixed according to mass percentage by using a microwave-assisted drying device at a high temperature, wherein the treatment time is 30-600 seconds, the treatment process is carried out under the protection of a reducing atmosphere, the microwave power density during the treatment process is 50-300 W / kg, and after the microwave-assisted treatment is completed, the mixed particles are cooled to room temperature in a vacuum environment with a vacuum degree of 7x10 -2 -6 Pa at 1250-1600 DEG C for 30-90 minutes, and then cooled to room temperature. The outer contour line of the sound absorption noise reduction hole is a regular 13-polygon, the inner contour of the sound absorption noise reduction hole is a circle with a diameter of 12.5mm-15mm, the sound absorption noise reduction hole is filled with phenolic resin sound absorption pad, and the thickness of the sound absorption pad is consistent with the backboard. First, the porous material is mixed with other components of the silica, carbon fiber and asbestos resin braking material to form a mixed raw material, then the backboard and the mixed raw material are filled in the forming mold, the mixed material is pressed, the pressing pressure is applied on the mold at the same time, the vibration frequency, the holding time, then the mold temperature is raised, the holding time is prolonged, finally the mold is demolded to complete the preparation.