Vibration-damping member and manufacturing method thereof

Abstract

To provide a vibration-damping member that prevents the detachment of aggregate included in an asphalt mixture and can maintain vibration-damping performance, and a method for producing the same.SOLUTION: A vibration-damping member comprises the space for machines, transportation devices, audio devices, and their parts subjected to vibrations, which is filled with an asphalt mixture prepared by mixing aggregate and asphalt. The asphalt mixture is uncompressed after filling. The vibration-damping member is filled with the asphalt mixture where the relationship between the asphalt ratio (x) and the aggregate's specific surface area (y) is within the ranges of the formulae (1)-(3). y≤-0.104x2+18.4x-170 (1), y≤-15.4x+1490 (2) and y>0 (3).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a vibration-damping member and a manufacturing method thereof, and more particularly to a vibration-damping member in which an asphalt mixture prepared by kneading aggregate and asphalt is filled into spaces in a base material that is a machine or tool, transport equipment, audio equipment, or a part thereof to which vibration is transmitted, and a manufacturing method thereof. [Background technology]

[0002] Patent Document 1 discloses a method for improving vibration and soundproofing effects by filling spaces in structures such as steel bridges with an asphalt mixture. However, Patent Document 1 is intended for large structures such as bridges, and steel materials are used to maintain strength. In such applications, maintaining strength is paramount, and the aim is merely to improve the vibration-damping and soundproofing effects within the scope of the application, and moreover, the asphalt mixture, which is widely used in various fields, is merely filled into the spaces from the surface layer of bridges, etc. In such a configuration, there is a risk that the aggregate in the asphalt may come off, and when used in machinery and equipment, transportation equipment, audio equipment, and parts thereof that transmit vibrations, the release of the aggregate may impair performance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 52-095842 Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the above circumstances, an object of the present invention is to provide a vibration-damping member capable of preventing the detachment of aggregate contained in an asphalt mixture and maintaining vibration-damping performance, and a method for manufacturing the same. [Means for solving the problem]

[0005] In order to solve the above problems, the main feature of the vibration-damping member of the present invention is that the space within a base material, which is a machine or tool, transport equipment, audio equipment, or a part thereof that transmits vibrations, is filled with an asphalt mixture prepared by mixing aggregate and asphalt, and the asphalt mixture is uncompressed after filling, and the relationship between the asphalt proportion (x) and the specific surface area (y) of the aggregate falls within the range expressed by the following formulas (1) to (3). y≦-0.104x 2 +18.4x-170 ···(1) y≦-15.4x+1490 (2) y>0 (3)

[0006] If the conditions of the above formulas (1) to (3) are satisfied, it is possible to prevent the aggregate from being separated from the asphalt mixture, as shown in the test results of FIG.

[0007] In addition to the above-mentioned main characteristics, the asphalt mixture may be filled such that the relationship between the asphalt ratio (x) and the specific surface area (y) of the aggregate falls within the range represented by the following formula (4). y≧-0.128x 2 +21.7x-472 ···(4)

[0008] If the conditions of the above formula (4) are satisfied, then, as shown in the test results in Figure 3, for example, the formation of a layer composed of simple asphalt on the surface of the asphalt mixture can be prevented, and a decrease in the logarithmic decrement can be prevented.

[0009] In the above-mentioned main feature, the space in the base material may have an opening communicating with the outside, and a coating layer made of a material different from the asphalt may be provided on the surface layer of the asphalt mixture near the opening.

[0010] This coating layer is expected to have effects such as preventing the asphalt mixture from coming off, preventing the aggregate from coming off due to deterioration and dissolution of asphalt caused by the adhesion of oil and organic solvents to the asphalt mixture, and improving the appearance of the asphalt mixture surface.

[0011] In the above-mentioned main feature, protrusions may be protruded from the base material into the space so as to penetrate into the asphalt mixture in a solidified state and strengthen adhesion to the base material.

[0012] The method for manufacturing a vibration-damping member according to any one of the above features is characterized in that the asphalt mixture is heated until it becomes liquid, filled into the space, and solidified to fix the asphalt mixture to the contact surface facing the space, thereby improving the adhesion of the asphalt mixture to the base material.

[0013] Another feature of the method for manufacturing a vibration-damping member according to any one of the above features is that the asphalt mixture is heated until it becomes liquid, filled into the space, and solidified in an unpressurized state, thereby adhering the asphalt mixture to the contact surface facing the space. According to the present invention, even if the asphalt mixture is filled and solidified in an unpressurized state, the above-mentioned adhesion can be obtained and the detachment of the asphalt mixture and aggregate can be prevented. Effect of the Invention

[0014] According to the above-mentioned features of the present invention, it has become possible to provide a vibration-damping member capable of preventing the aggregate contained in an asphalt mixture from being separated and maintaining vibration-damping performance, and a manufacturing method thereof.

[0015] Other objects, configurations and effects of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1A is a perspective view showing an example of a vibration-damping member according to the present invention, FIG. 1B is a cross-sectional view of FIG. 1A, and FIG. [Diagram 2] 1A is a perspective view of a test piece according to the present invention, FIG. 1B is a front view of the test piece, and FIG. [Diagram 3]1 is a graph showing the relationship between the asphalt ratio (horizontal axis X) of an asphalt mixture of the present invention and the specific surface area of ​​aggregate (vertical axis Y). [Figure 4] FIG. 1A is a cross-sectional view of a vibration-damping member showing an example in which a coating layer is provided, and FIG. 1B is a cross-sectional view of a vibration-damping member showing an example in which a protective layer is further provided on the vibration-damping member shown in FIG. [Diagram 5] 1A and 1B show a modified example of the base material in the present invention, where (a) is a perspective view showing the modified example of the base material, and (b) is a longitudinal sectional view of (a). [Figure 6] 1A and 1B show a modified example of the base material in the present invention, where (a) is a perspective view showing the modified example of the base material, and (b) is a longitudinal sectional view of (a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Next, an embodiment of the present invention will be described with reference to the drawings. As shown in Figures 1(a) and 1(b), the vibration-damping member 1 used in the present invention is formed by filling a space 3 in a metal base material 2 with an asphalt mixture 10, which is a vibration-damping filler. The base material 2 in Figure 1(c) is a cross-sectional view of one manufactured by, for example, a full mold casting method, and the base material 2, the space 3, and the opening 4 have various shapes.

[0018] The full mold casting method is a casting method suitable for the manufacture of non-mass products and large castings, in which a pattern is made from polystyrene foam, and this polystyrene foam is replaced with molten cast iron to produce a casting. Since it is possible to create space anywhere in the casting, the present invention is easily applicable. Also, unlike the wooden mold method, the full mold casting method can easily produce composite materials by setting different materials in a foam pattern, molding, and casting the resulting material inside, so it is easy to combine castings made of the various materials listed in the present invention. The base materials of each material may be attached by bolts, welding, etc. to form a composite structure.

[0019] (Examination policy) In the present invention, the purpose is to determine the appropriate range of the mixing ratio of asphalt and aggregate and the specific surface area of ​​the aggregate, which prevent the aggregate from being detached from the asphalt mixture filled in the space and prevent the formation of a layer of asphalt alone. The detachment of aggregate may impair the function of the member, and it is desirable to prevent this. In addition, while the damping performance is obtained by forming multiple boundary layers between the asphalt and aggregate, the formation of a layer of asphalt alone impairs the boundary layer and prevents a decrease in the logarithmic damping rate, so it is desirable to prevent the formation of the layer of asphalt alone.

[0020] (Relationship between aggregate and asphalt in asphalt mixture) In this test, the size of the boundary layer is related to the surface area of ​​the aggregate, and the surface area can be changed by mixing aggregates of different diameters, so the concepts of specific surface area and median diameter are used.

[0021] Here, the specific surface area is a measure of the surface area per unit volume, and is expressed as the surface area cm 2 / volume cm 3 In addition, the specific surface area used in this experiment is a calculated value assuming that all the aggregates used are perfect spheres.

[0022] In addition, the median diameter (D50) is the particle diameter at which the cumulative distribution of aggregate particle diameters is equal to the cumulative distribution of the larger and smaller sides when the cumulative distribution is divided into two groups based on a certain particle diameter. In this test, three types of aggregate, namely fine powder, fine aggregate, and coarse aggregate, each with three different median diameters (D50), are mixed to adjust the specific surface area.

[0023] The aggregates used were those listed in Table 1. D50 refers to the median diameter. The aggregate ratio wt% in the test results in Table 2 indicates the weight mix of coarse aggregate, fine aggregate, and fine powder within the total aggregate of 100%. The asphalt ratio (vol%) is the ratio of the volume of asphalt only to the volume of aggregate produced from the median diameter. The amount of asphalt was changed between 5 and 70 vol%, and the aggregate can be calculated from the remaining vol%. Modified asphalt modified with rubber or polymer was used for the asphalt.

[0024] [Table 1]

[0025] [Table 2]

[0026] (About the structure of the test piece) 1(c) shows the overall outer edge of both the base material 2 and the space 3, and since the figure is a cross section, the outer edge 20 is actually considered as an outer diameter surface, and the area is considered as a volume. The area of ​​the space 3 is determined by subtracting the area of ​​the base material 2 from the area of ​​the part shown by the outer edge 20.

[0027] In addition to cast iron and steel, various metals and nonmetals, which will be described later, can be used for the base material 2. Asphalt mixtures are mixtures of asphalt and aggregate, and come in various blends, which will be described later.

[0028] As shown in Figure 2, for the vibration damping test corresponding to the above-mentioned base material 2, a machined steel (SS400) box-shaped product with a thickness of 10 mm and dimensions of 300 mm length × 50 mm width × 30 mm height, with a space of 280 mm length × 30 mm width × 20 mm height, was used.

[0029] (Regarding the production of test specimens) A heated asphalt mixture was poured into the space 3 of the test piece shown in Figures 1 and 2, and the test piece 1 was placed in a muffle furnace and heated at 200°C for 2 hours, after which a vibration damping test was carried out at room temperature. This reproduces the situation when, when the component is large, the cooling of the heated asphalt mixture is slow, aggregates settle during cooling, and the asphalt itself separates and forms a layer on the surface. This was adopted because the presence or absence of a layer of asphalt itself was different in a comparative experiment in which the above test piece 1 was placed in a muffle furnace and not placed in it.

[0030] (Evaluation method) The evaluation was carried out on the following three points. Evaluation 1. Whether aggregate falls from asphalt mixture filled in space (Evaluation method) The opening of the test piece filled with asphalt mixture was faced downward, and vibration was applied to check for the aggregate falling. Evaluation 2. Presence or absence of a single asphalt layer in the same mixture (Evaluation method) The asphalt mixture filled in the test piece was removed, cut, and the cross section was observed to confirm the presence or absence of an asphalt simple layer and the thickness of the layer. Evaluation 3. Measurement of the logarithmic decrement of the test piece (Evaluation method) A test piece filled with asphalt vibration-damping material was struck, and the sound that was generated after passing through the test piece was imported into a personal computer and analyzed to determine the logarithmic damping rate.

[0031] (Combination of test conditions and results) The test results under the above test conditions are shown in Tables 1 and 2 and in the graph of Figure 3. Regarding the symbols and blot points of the test conditions An, Bn, and Cn (n is a natural number) shown in these, An shows good results in the above evaluations 1 to 3. Bn is a test condition that has a problem in the above evaluation 1 item, and Cn is a test condition that has a problem in the above evaluation 2 item.

[0032] Looking at these evaluation results, in order to satisfy the evaluation 1, it is necessary to satisfy the above formula (1) that passes through the boundary between points An and Bn. Also, in order to determine the upper limit of the evaluation, it is desirable to satisfy the above formula (2), which is an asymptote to points A11 and A12 using fine powder (L silica) with a median diameter of 0.035 mm, which is easy to obtain industrially and has good kneadability. Furthermore, the above formula (3) is a physically determined condition.

[0033] Furthermore, to satisfy the conditions of Test 2, it is necessary to satisfy the above formula (4) which passes through the boundary between points An and Cn.

[0034] (Analysis of the cause of aggregate falling from test specimens) Point Bn in Figure 3 of the test results is where aggregate fell, and referring to Tables 1 and 2, the following causes are considered: For example, if the aggregate ratio is the same, when the particle size of the aggregate becomes smaller and the specific surface area becomes larger, the number of aggregate particles increases, the total surface area increases, and the amount of asphalt that needs to be attached to the surface increases. However, if there is not enough asphalt to accommodate this, tiny gaps will occur in the asphalt mixture. In addition, in the above case, the apparent viscosity of the asphalt mixture becomes high, making mixing difficult. As a result, fine powder is generated to which the asphalt does not adhere sufficiently due to insufficient mixing. Furthermore, for example, if the specific surface area of ​​the aggregate is the same, when the proportion of asphalt in the asphalt mixture decreases, the amount of asphalt filled in the gaps between the aggregate decreases, resulting in the formation of cavities in the asphalt mixture. In addition, in the present invention, since the asphalt mixture is not compressed after being filled, it is difficult to improve the adhesion between the asphalt and the aggregate. As a result of the above, the bond between the asphalt and the aggregate weakens, increasing the risk of the aggregate falling due to vibration, etc.

[0035] (Analysis of the cause of the occurrence of a single layer of asphalt on the test specimen) Point Cn in Figure 3 of the test results indicates that a single layer of asphalt has occurred. Referring to Tables 1 and 2, the following causes are considered: For example, if the aggregate ratio is the same, when the particle size of the aggregate increases and the specific surface area decreases, the number of aggregate particles decreases and the settling rate of the aggregate increases. Furthermore, for example, if the specific surface area of ​​the aggregate is the same, an increase in the proportion of asphalt in the asphalt mixture will result in an excessive amount of asphalt.

[0036] As a result of the above, the asphalt becomes a single layer, forming a layer on the surface of the asphalt mixture. The presence of a boundary between the asphalt and aggregate in an asphalt mixture provides a vibration damping effect. Within an asphalt single layer, this boundary does not exist, and there is concern that the vibration damping effect will decrease, so it is important to prevent the formation of this asphalt single layer. The logarithmic damping rate is A25 (0.011, without asphalt single layer) and C7 (0.008, with asphalt single layer), which is consistent with the results of the above study.

[0037] In terms of manufacturing, asphalt mixture 10 containing aggregate is integrated with base material 2 as shown in Figs. 1(a) to (c), by heating asphalt mixture 10 to liquefy the asphalt, and then pouring the liquid into space 3 in base material 2 to fill and solidify it.

[0038] 4(a), a coating layer 11 may be provided on the surface layer of the asphalt mixture 10 visible from the opening 4 to cover this surface layer and prevent the above-mentioned separation. If oil such as hydraulic oil or organic solvents adhere to and permeate the asphalt mixture 10, this will cause deterioration or dissolution of the asphalt and cause the aggregate to separate, but providing the coating layer 11 makes it possible to prevent the above-mentioned problems from occurring. Also, the coating layer 11 may be provided to improve the appearance from the opening.

[0039] For this coating layer 11, a liquid curing resin that hardens later can be used, and a material that does not easily react with oils or organic solvents, such as epoxy, acrylic, or unsaturated polyester resins that harden due to reactions between heat, light, and materials, can be used. In addition, fine aggregate or fine powder of the above aggregates may be mixed into this resin. It is desirable for the material of the coating layer to have a larger logarithmic decrement than the asphalt.

[0040] A film may be used as the coating layer 11. An adhesive may be provided between the film and the coating layer 11, or a film that adheres well to the asphalt may be attached while the asphalt mixture 10 is heated. The film can be attached to the surface of the asphalt mixture 10 by vacuum drawing.

[0041] In addition to the above-mentioned coating layer 11, a protective layer 12 may be provided to cover the coating layer 11 as shown in Fig. 4(b). This protective layer 12 may be formed of, for example, an iron plate, an aluminum plate, another metal plate, or a resin plate or film. Although not shown, it is preferable to fix it to the base material 2 with fastening means such as bolts or screws, or with an adhesive.

[0042] The protective layer 12, by closing the opening 4 of the base material 2, can more reliably prevent the intrusion of oil and hydraulic oil into the space 3. In this case, by filling the space 3 closed by the protective layer 12 with the resin or the like of the coating layer 11 so that no cavity is formed, the effect of preventing the intrusion of oil and the like is improved.

[0043] Finally, the following describes further possible embodiments of the present invention. The same reference numerals are used to designate the same members as those in the above embodiment.

[0044] From the viewpoint of preventing the asphalt mixture 10 from falling out of the space 3, as shown in Fig. 5, protrusions 5 that penetrate into the solidified asphalt mixture to strengthen its adhesion to the base material may be made to protrude from the base material 2 into the space 3. These protrusions 5 may be provided on the inner surface of the base material 2 as first protrusions 5a with a partially swollen portion in the case of the bottom surface, or as second protrusions 5b that simply protrude from the inner surface in the case of the side walls. In either case, as long as the protrusions 5 have a portion in a direction that intersects with the separation direction D of the asphalt mixture 10, separation can be effectively prevented.

[0045] As shown in FIG. 6, a connector 6 may be provided in the space 3 of the base material 2 to connect the inner surface of the space 3. Various materials may be used for this connector 6, but for example, a separately manufactured cast steel rod may be connected by welding, fitting, screwing, or other methods. By connecting the parts of the base material 2 across the space 3, the strength of the base material is improved, and by installing it in a direction crossing the separation direction D of the asphalt mixture 10, the separation of the asphalt mixture 10 can be prevented. The first and second connectors 6a and 6b are perpendicular to each other, and by arranging them in the cross direction, the strength of the parts of the base material 2 is further improved.

[0046] In the above embodiment, modified asphalt modified with rubber or a high molecular weight polymer is used as the asphalt, but asphalt alone such as straight asphalt or blown asphalt, or a mixture of asphalt alone and modified asphalt may also be used.

[0047] The above-mentioned base material may be cast iron such as spheroidal graphite cast iron, flake graphite cast iron, or high Cr cast iron, or a base metal such as an aluminum alloy, a magnesium alloy, or a copper alloy. Also, non-metallic materials such as wood, ceramics, or glass may be used. There is no particular limitation on the method for producing the above-mentioned base material, and the base material may be produced by casting, can manufacturing, machining, or other forming processes. By using the asphalt vibration-damping material described in the present invention for a base material with a high logarithmic damping rate, the vibration-damping performance can be further improved. On the other hand, even if the material that can be used as the base material is limited, there is an advantage in that the vibration-damping performance can be improved.

[0048] From the viewpoint of durability, a part of the above-mentioned base material may be made of hypereutectic flake graphite cast iron, and the use surface or load-bearing part may be any one of FC250 to FC350, or FCD500 to FCD800, austenitic cast iron, CV cast iron, and bainite cast iron. The use surface and load-bearing part mainly refers to the sliding surface of the equipment, but also includes parts where the load acts on the surface of the equipment or where the surface layer is subjected to impacts. Austenitic cast iron may be a low-thermal expansion cast iron with about 35% nickel, and used as a structure with vibration-damping properties and low expansion properties.

[0049] The aggregate in the filler may be one or more of silica, alumina, magnesia, metal, or metal oxide, or may be a mixture of two or more of them. For example, a heavy aggregate such as iron oxide or shot may be mixed with diatomaceous earth, pumice, or hollow silica beads.

[0050] The above-described embodiments of the present invention can be implemented in combination with each other, and each of the above-described embodiments can be modified without departing from the spirit of the present invention. [Industrial Applicability]

[0051] The vibration-damping member according to the present invention can be applied to all devices that generate vibrations or sounds, and can be used, for example, as a part of machine tools, construction machines, industrial machines, measuring devices, surface plates, transport devices, audio devices, printing devices, medical devices, press dies, etc. It can also be used, for example, as parts and accessories of the above devices, such as cutting tools and audio insulators. [Explanation of symbols]

[0052] 1: vibration-damping member, 2: base material, 3: space, 4: opening, 5: protrusion, 5a: first protrusion, 5b: second protrusion, 6: connector, 6a: first connector, 6b: second connector, 10: asphalt mixture (vibration-damping filler), 11: coating layer, 12: protective layer, 20: outline (surface), D: detachment direction

Claims

1. A vibration-damping member in which an asphalt mixture made by kneading aggregate and asphalt is filled into the space of a base material that is a machine, a transport device, an audio device, or a part thereof to which vibration is transmitted, The asphalt mixture is uncompacted after filling, A vibration-damping member filled with an asphalt mixture in which the relationship between the asphalt ratio (x) and the specific surface area (y) of the aggregate falls within the ranges shown by the following formulas (1) to (3). y≦-0.104x 2 +18.4x-170 ・・・(1) y≦-15.4x+1490...(2) y>0 (3)

2. 2. The vibration damping member according to claim 1, which is filled with an asphalt mixture in which the relationship between the asphalt ratio (x) and the specific surface area (y) of the aggregate falls within the range expressed by the following formula (4). y≧-0.128x 2 +21.7x-472 ・・・(4)

3. 2. The vibration-damping member according to claim 1, wherein the space in the base material has an opening communicating with the outside, and a coating layer made of a material different from the asphalt is provided on the surface layer of the asphalt mixture near the opening.

4. 2. The vibration-damping member according to claim 1, further comprising projections projecting from said base material into said space, said projections being interwoven with said asphalt mixture in a solidified state to strengthen adhesion to said base material.

5. A method for manufacturing a vibration damping member according to any one of claims 1 to 4, comprising the steps of: A method for manufacturing a vibration-damping member, comprising heating the asphalt mixture until it becomes liquid, filling the space with the asphalt, and solidifying the asphalt mixture to adhere to a contact surface facing the space.

6. A method for manufacturing a vibration damping member according to any one of claims 1 to 4, comprising the steps of: A method for manufacturing a vibration-damping member, comprising heating the asphalt mixture until it becomes liquid, filling the space with the asphalt, and solidifying the asphalt in an unpressurized state to adhere the asphalt mixture to a contact surface facing the space.

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