CN114558992B

CN114558992B - Method for manufacturing micro-perforated metal plate

Info

Publication number: CN114558992B
Application number: CN202210167976.2A
Authority: CN
Inventors: 翟国庆; 郭婧怡; 李军; 何建龙
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2022-02-23
Filing date: 2022-02-23
Publication date: 2023-03-14
Anticipated expiration: 2042-02-23
Also published as: CN114558992A

Abstract

The invention discloses a manufacturing method of a micro-perforated metal plate, which comprises the steps of injecting liquid metal into a mold assembled by a concave template and filling particles, solidifying, cooling and demolding to obtain the micro-perforated metal plate with variable cross-section perforations; the pore-forming pore size is controlled by adjusting the injection amount of the liquid metal or the size of the filler particles. The invention can meet the perforation aperture requirement of any micro-perforated plate, is suitable for manufacturing various metal plates, and has the characteristics that the thickness of the manufactured plate is larger, and the perforation aperture is smaller; the mould can be used repeatedly, and easy size adjustment or damage change practices thrift the cost.

Description

Method for manufacturing micro-perforated metal plate

Technical Field

The invention relates to the technical field of noise control, in particular to a manufacturing method of a micro-perforated metal plate.

Background

The resonance sound absorption structure of the micro-perforated plate is widely applied to the field of noise control, the perforation aperture of the resonance sound absorption structure is smaller than 1mm, the perforation rate is not greater than 5%, and the sound absorption performance of the resonance sound absorption structure is superior to that of a common perforated plate. According to the sound absorption theory of the micro-perforated plate, the sound absorption coefficient and the bandwidth which characterize the sound absorption characteristic of the micro-perforated plate are mainly determined by the acoustic resistance r and the acoustic reactance wm of the structure. Acoustic resistance

Sound reactance

Where t is the plate thickness, d is the hole diameter, and σ is the perforation rate. From this, it is found that the increase in the plate thickness and the decrease in the hole diameter are favorable for the improvement of the sound absorption performance of the microperforated plate. In addition, the sound absorption performance of the micro-perforated plate can be further improved by adopting the variable cross-section perforation.

Metal sheets are of great interest because of their high mechanical strength, high temperature resistance, corrosion resistance, etc. The realization of perforation with thickness less than 1mm on a metal plate with certain thickness and hardness is a technical difficulty in producing micro-perforated metal plates at present. The traditional method for manufacturing the micro-perforated metal plate mainly adopts the method of mechanically punching, drilling, pressing and pricking the metal plate, the method can process the metal plate with the hole diameter generally more than 0.5mm, is usually used for processing the plate with smaller hardness such as an aluminum plate and the like, and is particularly difficult to perforate the metal plate with large hardness such as a steel plate and the like, and the hole diameter of the perforation does not exceed the thickness of the steel plate generally. The laser perforation technology can meet the requirements of different perforation apertures, is suitable for processing various plates, but has high processing cost and long processing time.

In patent specification No. CN1136082C, a method for processing a microporous metal plate by chemical etching is disclosed, which comprises the following steps in the following order:

firstly, designing parameters of a microporous plate according to sound absorption requirements, wherein the parameters comprise the aperture, the perforation rate, the hole spacing and the hole shape of a micropore, drawing a micropore arrangement diagram, and manufacturing a transparent film;

secondly, cleaning the metal plate to be processed, and then pasting or coating the anti-corrosion photosensitive film on the front and back surfaces of the metal plate;

thirdly, respectively placing two transparent films printed with micropore arrangement patterns on the front and back surfaces of the metal plate with the anti-corrosion photosensitive coating, and carrying out exposure together;

fourthly, the exposed metal plate is placed into a developing solution for development treatment, and the corrosion-resistant film at the position of the micropore disappears after the development treatment, so that the metal surface is exposed;

fifthly, in the corrosion tank, adding a solution prepared by adding an acidic substance into ferric trichloride to spray the metal plate with the developed shadow, corroding the metal exposed on the metal surface after spraying, and reserving the metal attached with the corrosion resistant film;

sixthly, cleaning the metal plate by using clear water, soaking the metal plate by using an alkaline solution, and removing the anti-corrosion layer.

The method can be used for manufacturing metal plates with the aperture of 0.1-0.4mm in large batch, but is mainly suitable for processing metal sheets, and the chemical corrosive is not environment-friendly.

Disclosure of Invention

The invention aims to provide a method for manufacturing a micro-perforated metal plate, which can meet the requirements of aperture of any micro-perforated hole and is suitable for manufacturing micro-perforated plates made of various metal materials.

A method for manufacturing a micro-perforated metal plate comprises the steps of injecting liquid metal into a mold assembled by a concave template and filling particles, solidifying, cooling and demolding to obtain the micro-perforated metal plate with variable cross-section perforations; the pore-forming pore size is controlled by adjusting the injection amount of the liquid metal or the size of the filler particles.

Preferably, the concave template comprises a bottom plate and side walls embedded in the bottom plate and located on the periphery of the bottom plate, the bottom plate is provided with a plurality of frustum-shaped (including circular truncated cones or prismatic tables and the like) through holes, the filling particles are embedded in the through holes, and the filling particles are cone-shaped or frustum-shaped. Wherein the horizontal cross-sectional dimension of the top of the filler particles is smaller than the perforation aperture of the target micro-perforated metal sheet.

Preferably, the filling particles are embedded into the through holes from the lower part of the bottom plate, the tops of the filling particles penetrate out of the upper surface of the bottom plate, the bottoms of the filling particles exceed the bottoms of the bottom plate, and the upper openings of the through holes are tightly attached to the filling particles.

Specifically, the concave template is inverted, so that the filling particles are embedded into the frustum-shaped through holes from the bottom of the bottom plate, the tops of the filling particles penetrate out of the upper surface of the bottom plate, the bottoms of the particles exceed the bottom of the bottom plate, and the upper openings of the frustum-shaped through holes of the bottom plate are tightly attached to the filling particles. After the assembly is completed, the die is arranged in a positive mode.

Preferably, the bottom of the filling particle is provided with a handle which is convenient for a manipulator to grab, so that the filling particle is convenient to arrange in the platform-shaped perforation of the concave template, and the damaged filling particle in the production process is convenient to replace.

The thickness of the liquid metal injection is less than the height of the part of the filling particles protruding out of the upper surface of the bottom plate.

Preferably, when the size of the die is fixed, the injection amount of the liquid metal is increased, so that the thickness of the liquid metal layer is increased, and the pore diameter of the pore is reduced; when the thickness of the target micro-perforated metal plate is constant, the concave template is kept unchanged, the cone angle or the included angle between lateral edges of the filling particles is reduced, and the pore-forming aperture is reduced.

Preferably, the filler particles and the concave template are made of a high temperature resistant material.

Preferably, the bottom plate and the side wall are integrally formed.

The invention has the beneficial effects that:

(1) The invention is suitable for manufacturing various micro-perforated metal plates, can meet the requirements of any micro-perforated aperture, and the manufactured plate has the characteristics of larger thickness and smaller perforated aperture, thus being beneficial to simultaneously improving the sound absorption performance and the mechanical strength of the micro-perforated plate.

(2) The mold can be used repeatedly, and compared with an integrated mold, the concave mold plate and the filling particles are mutually independent, so that the size adjustment or damage replacement is easy, and the cost is saved.

Drawings

FIG. 1 is a schematic view of a packed particle and a concave template of the present invention;

FIG. 2 is a schematic view of the manufacturing of the microporous metal plate according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Examples

A microperforated steel sheet was produced in a square of 0.6mm,100mm X100 mm in thickness, with a perforation hole diameter of 0.4mm, a hole pitch of 3mm and a perforation rate of 1.1%.

The specific implementation steps are as follows:

the filling particles 1 and the concave template are made of ceramic. As shown in fig. 1, the packed particles 1 are conical, with a height H of 3.2mm and a bottom diameter D of 3.2mm; the bottom of the filling particle 1 is provided with a hexagon nut, the size M of the hexagon nut is 3.5mm, and the thickness K of the hexagon nut is 3mm. The concave template consists of a bottom plate 21 and a side wall 22, wherein the bottom plate 21 is 120mm long and 120mm wide, the thickness m is 1mm, the side wall 22 in the length direction is 110mm long, the side wall 22 in the width direction is 110mm long, the side wall 22 is 10mm high, the thickness n is 5mm, the distance l between the outer edge of the side wall 22 and the boundary of the bottom plate 21 is 5mm, and the depth s of the side wall 22 embedded into the bottom plate 21 is 0.5mm; the bottom plate 21 is provided with a plurality of truncated cone-shaped through holes 3, the aperture a of the top of each through hole 3 is 0.5mm, the aperture b of the bottom of each through hole 3 is 1mm, and the through hole distance c is 2.4mm. The filler particles 1 are inserted into the perforations 3 from below the bottom plate 21.

As shown in FIG. 2, molten steel 4 was poured into a concave mold plate 2 in which filling particles 1 were embedded so that the thickness of the molten steel layer was 0.6mm. And solidifying the molten steel to form a steel plate, demolding after the steel plate is cooled, and taking down the cooled steel plate from the mold to obtain the target perforated steel plate.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.

Claims

1. A method for manufacturing a micro-perforated metal plate is characterized in that liquid metal is injected into a mold assembled by two independent parts, namely a concave template and filling particles, and the micro-perforated metal plate with variable cross-section perforations is manufactured after solidification, cooling and demolding; the pore-forming aperture is controlled by adjusting the injection amount of the liquid metal or the size of the filling particles;

the concave template comprises a bottom plate and side walls which are embedded on the bottom plate and located on the periphery of the bottom plate, a plurality of platform-shaped through holes are formed in the bottom plate, the filling particles are embedded into the through holes and are cone-shaped or platform-shaped, and the horizontal cross section size of the tops of the particles is smaller than the aperture of the target micro-perforated metal plate through holes;

the filling particles are embedded into the through holes from the lower part of the bottom plate, the tops of the filling particles penetrate out of the upper surface of the bottom plate, the bottoms of the filling particles exceed the bottom of the bottom plate, and the openings at the upper parts of the through holes are tightly attached to the filling particles;

when the size of the die is fixed, increasing the injection amount of the liquid metal to increase the thickness of the liquid metal layer and reduce the pore diameter of the formed hole; when the thickness of the target micro-perforated metal plate is constant, the concave template is kept unchanged, the cone angle or the included angle between lateral edges of the filling particles is reduced, and the pore-forming aperture is reduced.

2. The method of claim 1, wherein the bottom of the filler particles is provided with a handle for easy gripping by a robot.

3. The method of claim 1, wherein the liquid metal is injected to a thickness less than the height of the filler particles protruding above the upper surface of the base plate.

4. The method of claim 1, wherein the filler particles and the concave form are made of a high temperature resistant material.

5. The method of claim 1, wherein the base plate and the sidewalls are integrally formed.