Disclosure of Invention
The invention provides a method for preparing an underwater sound absorption plate with a cavity with a complex structure, which has the beneficial effect that the method can solve the problem of processing the cavity with the complex structure in a viscoelastic damping material.
A preparation method of an underwater acoustic board with a cavity with a complex structure comprises the following steps:
step one, a cavity entity mold digital model is created by utilizing computer software, and then the digital model is led into additive manufacturing equipment to manufacture a cavity entity mold;
assembling a cavity entity mold, casting by using paraffin, and disassembling the cavity entity mold after solidification to obtain a cavity entity wax mold; the cavity solid wax mold is formed by adding a positioning column on the basis of a complex-structure cavity structure in the sound absorption plate;
manufacturing a sound absorption plate casting mold, wherein the mold consists of an upper bottom plate, a lower bottom plate and a frame, a cavity is formed among the upper bottom plate, the lower bottom plate and the frame, the lower bottom plate is in a boss shape, and a through hole is formed in the plane and matched with a positioning column on a cavity solid wax mold; the upper bottom plate is in an inverted boss shape, and the lower bottom plate is in a regular boss shape; the height of the frame is the sum of the thickness of the sound absorption plate and the heights of the bosses of the upper bottom plate and the lower bottom plate;
step four, preparing a sound absorption plate by casting, assembling a lower bottom plate and a frame of a sound absorption plate casting mold, inserting a positioning column on a cavity entity wax mold into a through hole on the lower bottom plate, pouring a liquid viscoelastic damping material into the mold until the whole mold is filled, covering an upper bottom plate, pressing the upper side of the upper bottom plate, and maintaining the pressure until the viscoelastic damping material is solidified;
step five, demolding to obtain the sound absorption plate with the embedded wax mold;
and step six, melting the wax mold to obtain the underwater acoustic board with the cavity with the complex configuration.
Preferably, the cavity solid mold is divided into a plurality of pieces along the central axis, and the cavity solid mold is provided with a positioning pin and a clamping hole, so that the multi-piece cavity solid mold is assembled and connected.
Preferably, when the wax pattern is manufactured in the second step, a small amount of silicone oil is coated on the inner surface of the cavity entity mold, so that the integrity of the wax pattern obtained in the mold opening process is ensured.
Preferably, the sound absorption plate casting mold is made of polytetrafluoroethylene.
Preferably, the inner size of the frame of the sound absorption plate casting mold is in interference fit with the boss of the lower bottom plate and is in clearance fit with the boss of the upper bottom plate.
Preferably, a plurality of through holes are formed in the lower bottom plate of the sound absorption plate casting mold and are arrayed or staggered.
Preferably, the viscoelastic damping material is one of polyurea, polyurethane, polyurea composite material and polyurethane composite material.
Preferably, the pressure applied during the casting preparation of the sound absorption plate in the fourth step is 1-20 MPa.
Preferably, the temperature used for melting the mold is 50-100 ℃.
Preferably, the internal shape formed by the cavity solid mold is a double trumpet shape or a vase shape.
The preparation method of the underwater acoustic board with the cavity with the complex structure has the beneficial effects that:
the method is simple and easy to implement, short in preparation period and low in cost, can solve the problem of processing a cavity with a complex configuration in the viscoelastic damping material, and the obtained plate has the advantages of smooth upper and lower surfaces, complete internal cavity structure, smooth inner wall and high precision.
Detailed Description
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.
The first embodiment is as follows:
the following describes the present embodiment with reference to fig. 1 to 6, and a method for manufacturing an underwater acoustic board with a cavity having a complex configuration includes the following steps:
step one, a cavity entity mold digital model is created by utilizing computer software, and then the digital model is led into additive manufacturing equipment to manufacture a cavity entity mold;
assembling a cavity entity mold, casting by using paraffin, and disassembling the cavity entity mold after solidification to obtain a cavity entity wax mold; the cavity solid wax mold is formed by adding a positioning column on the basis of a complex-structure cavity structure in the sound absorption plate;
step three, manufacturing a sound absorption plate casting mold, wherein the mold consists of an upper bottom plate 1, a lower bottom plate 4 and a frame 2, a cavity 3 is formed among the upper bottom plate 1, the lower bottom plate 4 and the frame 2, the lower bottom plate 4 is in a boss shape, and a through hole is formed in the plane and matched with a positioning column 6 on a cavity solid wax mold; the upper bottom plate 1 is in an inverted boss shape, and the lower bottom plate 4 is in a regular boss shape; the height of the frame is the sum of the thickness of the sound absorption plate and the heights of the bosses of the upper base plate 1 and the lower base plate 4;
step four, preparing a sound absorption plate by casting, assembling a lower bottom plate and a frame of a sound absorption plate casting mold, inserting a positioning column 6 on a cavity entity wax mold into a through hole on the lower bottom plate, pouring a liquid viscoelastic damping material into the mold until the whole mold is filled, covering an upper bottom plate, pressing the upper side of the upper bottom plate, and maintaining the pressure until the viscoelastic damping material is solidified; extruding the redundant liquid viscoelastic damping material out of the gap between the upper bottom plate and the frame 2 to obtain a flat sound-absorbing plate;
step five, demolding to obtain the sound absorption plate with the embedded wax mold;
and step six, melting the wax pattern to obtain the underwater acoustic board with the cavity with the complex configuration, wherein the liquid viscoelastic damping material is not melted into liquid when being heated, and only the wax pattern is melted into liquid and then flows out.
The second embodiment is as follows:
the present embodiment is described below with reference to fig. 1 to 6, in which the cavity solid mold is divided into multiple pieces along the central axis, and the cavity solid mold is provided with positioning pins and clamping holes, so as to assemble and connect the multiple pieces of cavity solid mold.
The third concrete implementation mode:
in the following, the present embodiment is described with reference to fig. 1 to 6, and when the wax pattern is manufactured in the second step, a small amount of silicone oil is coated on the inner surface of the solid mold of the cavity to ensure the integrity of the wax pattern obtained when the mold is opened. Avoid the wax matrix to adhere to cavity entity mould.
The fourth concrete implementation mode:
the present embodiment will be described with reference to fig. 1 to 6, in which the acoustic panel casting mold is made of polytetrafluoroethylene.
The fifth concrete implementation mode:
the present embodiment will be described with reference to fig. 1 to 6, wherein the inner dimension of the frame of the acoustic board casting mold is in interference fit with the boss of the lower base plate 4 and in clearance fit with the boss of the upper base plate 1. So that the upper bottom plate 1 is convenient to be detached and then the liquid viscoelastic damping material is poured into the cavity 3.
The sixth specific implementation mode:
the present embodiment is described below with reference to fig. 1 to 6, in which a plurality of through holes are formed in the lower plate of the acoustic board casting mold, and the through holes are arranged in an array or in a staggered manner. A plurality of cavity entity wax moulds can be installed like this, and then open a plurality of sound absorption cavities on the acoustic baffle.
The seventh embodiment:
the present embodiment will be described with reference to fig. 1 to 6, wherein the viscoelastic damping material is one of polyurea, polyurethane, polyurea composite material and polyurethane composite material.
The specific implementation mode is eight:
the present embodiment will be described with reference to FIGS. 1 to 6, wherein the pressure applied during the casting process in the fourth step is 1 to 20 MPa.
The specific implementation method nine:
the present embodiment will be described with reference to FIGS. 1 to 6, wherein the temperature used for the investment is 50 to 100 ℃.
The detailed implementation mode is ten:
in the following description of the present embodiment with reference to fig. 1 to 6, the internal shape of the cavity solid mold is a double trumpet shape or a vase shape. The sound absorption cavity in the shape of a double horn or a vase can effectively absorb sound underwater.
It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and that various changes, modifications, additions and substitutions which are within the spirit and scope of the present invention and which may be made by those skilled in the art are also within the scope of the present invention.