Automotive sound absorbers and floor silencers

Abstract

To provide a sound absorber for automobile and a floor silencer for automobile that utilize a layered composite component consisting of a plurality of layers including a glass fiber layer so as to exhibit superior sound absorbing performance against noise.SOLUTION: Each mixed member is formed of a crushed raw material in a three-dimensional shape as a mixed body among a plurality of crushed raw materials obtained by crushing layered composite raw materials including a glass fiber layer into various shapes including the three-dimensional shape and a line shape, and a plurality of glass fibers, extended, involved in the crush, from parts corresponding to the glass fiber layer, of the mixed body as mixed glass fiber parts. In an agitation mixed body consisting of respective mixed members mixed by agitation in a binder and the binder, a mixed glass fiber part of each mixed member is located in at least one maze-like path formed between mutually facing mixed bodies in each mixed member. The agitation mixed body is formed in a predetermined layer shape conforming to a sound absorber for an automobile.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an automobile sound absorber and an automobile floor silencer that are suitable for absorbing noise entering the interior of an automobile. [Background technology]

[0002] In recent years, a wide variety of automobiles have been developed, and the number of these automobiles produced is on the rise. Accordingly, the number of automobiles that need repair due to automobile accidents and the number of automobiles that are scrapped are also on the rise. In line with this increasing trend, various automobile parts tend to be disposed of as scrap parts. With the increasing number of automobiles today, this leads to excessive economic losses due to the disposal of scrapped parts. Therefore, effective measures to mitigate this economic loss are needed.

[0003] To meet such demands, recycling of discarded parts can be considered. By recycling discarded parts, not only can the discarded parts be effectively reused, but also the economic loss caused by discarded parts can be effectively reduced.

[0004] For example, if parts mounted on the roof of an automobile (hereinafter referred to as roof parts) were to be disposed of as waste, it would result in a significant economic loss given the large number of automobiles produced today. Therefore, there is a demand for the recycling of roof parts that would otherwise be disposed of.

[0005] On the other hand, noise propagates into the interior of a vehicle when the vehicle is stopped or running. For example, in a vehicle powered by an engine, the engine generates noise having frequencies within a wide frequency range, from low to high.

[0006] Furthermore, in an electric vehicle using an electric motor as a prime mover, a plurality of on-board batteries and inverters generate noise having frequencies within the high frequency band.

[0007] Furthermore, regardless of the type of engine, when a vehicle is running, noise in the low to mid frequency range is generated from the road, tires, etc.

[0008] When these noises propagate into the interior of an automobile, they cause discomfort to the passengers, and therefore, in recent years, there has been a strong demand for measures to reduce such noises.

[0009] For this reason, if roof components that would otherwise be discarded as described above could be recycled as noise-reducing components, in other words, sound-absorbing components, the discarded roof components could not only contribute to noise reduction measures but also to reducing the economic losses described above.

[0010] In response to this, for example, it is conceivable to use chip urethane manufactured by the chip urethane manufacturing method disclosed in Patent Document 1 below as a sound absorbing part.

[0011] In this chip urethane manufacturing method, chip material is formed by crushing discarded parts made of urethane or the like in a crusher. Next, a urethane binder is mixed with the chip material in a mixer. The mixture is then molded in a press mold to produce the above-mentioned chip urethane. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Japanese Patent Application Publication No. 8-72075 Summary of the Invention [Problem to be solved by the invention]

[0013] However, in the above-described method for producing chip urethane, if the discarded parts are a single urethane layer, the urethane layer cannot exhibit good sound absorbing performance against noise.

[0014] Therefore, even if the single urethane layer is crushed into chips and mixed with a binder to form the chip urethane described above, the chip urethane will still not be able to exhibit the same good sound absorption performance as a single urethane layer. This is also true when the discarded part is a layered composite part consisting of, for example, a urethane layer and a nonwoven fabric layer.

[0015] Therefore, in order to address these issues, the present invention aims to provide an automotive sound absorber and an automotive floor silencer that utilize a laminated composite part consisting of multiple layers including a glass fiber layer and that can exhibit excellent sound absorption performance against noise. [Means for solving the problem]

[0016] In order to solve the above problems, the inventors have created a sound absorber that can exhibit excellent sound absorption performance against noises having frequencies in a wide frequency range, including the low and medium frequency ranges, by utilizing a laminated composite part containing a glass fiber layer. This section explains how this sound absorber was created.

[0017] As explained in the prior art, even if chip urethane is formed as described above using discarded single-layer parts consisting of a single urethane layer or laminated composite parts consisting of a urethane layer and a nonwoven fabric layer, the chip urethane will not be able to exhibit good sound-absorbing performance against noise.

[0018] In response to this, various materials generally recognized as suitable for sound absorption other than urethane and nonwoven fabric were used as various single-layer components or laminated composite components, and each of these single-layer components or laminated composite components was repeatedly chipped and mixed with a binder to form a laminate such as chip urethane.

[0019] In this process, the roofing components were used as the laminated composite components described above, and the roofing components were chipped in the same manner as described above, mixed with a binder, and then laminated and solidified in a dispersed state to form a laminate similar to chip urethane.

[0020] When the sound absorbing performance of the laminate was investigated, it was found that the laminate can exhibit excellent sound absorbing performance at least for noises having frequencies in the low and medium frequency bands.

[0021] When we investigated the reason why this laminate is able to exhibit such excellent sound absorption performance against noise having frequencies in the low and medium frequency range, we found that the reason is mainly due to the glass fiber layer contained in the laminated composite part, which is a roof part.

[0022] This point was examined in more detail. When the roof component described above is crushed into chips, the roof component is dispersed as a plurality of crushing members each having a large, three-dimensional crushing body and a plurality of small, linear or thin-shaped crushing members. Here, a plurality of glass fiber portions are formed so as to extend from the crushing body when the roof component is crushed. This means that each of the plurality of crushing members is composed of a large, three-dimensional crushing body and a plurality of glass fiber portions extending from the crushing body.

[0023] Among the dispersed grinding elements, those with large, three-dimensional grinding bodies were mixed with a binder to form a laminate similar to chip urethane. In the laminate formed in this way, paths were formed in the chip urethane in a maze-like pattern between the opposing grinding bodies, and multiple glass fiber portions were dispersed within the paths.

[0024] In order to examine the sound absorption performance of the laminate formed in this manner, noise having frequencies across a wide frequency range was incident on the laminate, and it was found that the laminate exhibited excellent sound absorption performance for noise having frequencies in the low to medium frequency range among the above noises.

[0025] After detailed investigation into this point, it was found that when noise passes through the multiple glass fiber sections and along the labyrinth-like shape of the above-mentioned path, the noise consumes its vibration energy, thereby providing the laminate with excellent sound absorption performance.

[0026] It was also found that by adjusting the size of the three-dimensional shape of the large pulverizing elements, the laminate can exhibit excellent sound-absorbing performance against noises having frequencies in the low and medium frequency ranges and noises having frequencies in the high frequency ranges.

[0027] Furthermore, it was found that even for automobile parts other than roof parts, if the part is a multi-layer component containing a glass fiber layer, the part can be chipped in the same way as the roof part and laminated while mixing and stirring with a binder to form a laminate such as chip urethane, and the laminate can exhibit excellent sound-absorbing performance against noise, as described above.

[0028] Therefore, the inventors came up with the idea that, by utilizing laminated composite parts containing glass fiber layers among automobile parts, it is possible to form a sound absorber that can exhibit excellent sound absorption performance against noise having frequencies over a wide frequency range.

[0029] In order to solve the above problems, the present invention has been made as follows based on the above-mentioned idea.

[0030] According to claim 1, the sound absorber for an automobile according to the present invention is formed into a predetermined layer shape.

[0031] In the automotive sound absorber, The plurality of mixing members are each composed of a plurality of pulverized raw materials obtained by pulverizing a laminated composite raw material (100) formed by laminating a porous layer (110, 150), a thermosetting resin layer (130), and a glass fiber layer (120, 140) having a plurality of glass fibers into various shapes including at least a three-dimensional shape and a linear shape, and the three-dimensional pulverized raw materials are used as a mixing body (Pa), and a plurality of glass fibers extending from a portion of the mixing body corresponding to the glass fiber layer as a result of the pulverization are used as a mixed glass fiber portion. the mixing body and the mixed glass fiber portion of each of the plurality of mixing members are stirred and mixed in a dispersed state in the binder to form a stirred mixture together with the binder, The stirred mixture has at least one labyrinth-like path formed between a plurality of opposing mixing bodies among the mixing bodies of the plurality of mixing elements, The mixed glass fiber portion of each of the plurality of mixing elements is located within the at least one labyrinth path; The stirred mixture is formed into the predetermined layer shape.

[0032] The automotive sound absorber thus formed is formed by dispersing a plurality of mixed elements in a binder. Therefore, in this automotive sound absorber, the plurality of mixed elements have a plurality of glass fiber portions extending from each of the mixed elements in a dispersed state in the binder. Furthermore, at least one labyrinth-like path is formed between opposing mixing elements of the plurality of mixing elements, and the plurality of mixed glass fiber portions of each of the plurality of mixing elements are located within the at least one labyrinth-like path.

[0033] When noise enters an automobile sound absorber having a predetermined layered shape from one of its opposing surfaces, the noise travels through the interior of the automobile sound absorber toward the other surface.

[0034] As described above, the mixed glass fiber portions of each of the mixed elements are located within at least one labyrinth path, so that when noise enters the automotive sound absorber as described above, the noise travels primarily through at least one labyrinth path.

[0035] At this time, the noise travels along the labyrinth shape of the labyrinth path. Furthermore, each glass fiber in the mixed glass fiber portion has the elasticity and rigidity of a glass material. Therefore, the noise travels along the labyrinth shape of the labyrinth path while colliding with each glass fiber in the mixed glass fiber portion.

[0036] As a result, the noise travels while consuming vibration energy by vibrating each glass fiber due to the elasticity and rigidity of the glass fiber, and also travels along the maze shape of at least one maze-like path while consuming vibration energy.

[0037] As a result, noise is significantly reduced due to collisions with the mixed glass fiber portion and the labyrinth shape of the at least one labyrinth path, which means that the automotive sound absorber with the above-mentioned configuration can exhibit excellent sound absorption performance.

[0038] According to claim 2, the sound absorber for an automobile according to the present invention is formed into a predetermined layer shape.

[0039] In the automotive sound absorber, a plurality of mixing elements and a binder; The plurality of mixing members each comprise a mixing body, and among a plurality of pulverized raw materials obtained by pulverizing a laminated composite raw material, which is obtained by sequentially laminating a one-side porous layer, a one-side glass fiber layer having a plurality of glass fibers, a urethane foam layer, a other-side glass fiber layer having a plurality of glass fibers, and a other-side porous layer, into various shapes including at least a three-dimensional shape and a linear shape, the three-dimensional pulverized raw material is used as the mixing body, and a mixed glass fiber portion is made of a plurality of glass fibers which extend from a portion of the mixing body corresponding to at least one of the one-side glass fiber layer and the other-side glass fiber layer as a result of the pulverization. The mixing bodies of the plurality of mixing members and the mixed glass fiber portion are stirred and mixed in a dispersed state in the binder to form a stirred mixture together with the binder, The stirred mixture has at least one labyrinth path formed between opposing mixing bodies of the mixing elements in the binder, The mixed glass fiber portion of each of the plurality of mixing elements is located within the at least one labyrinth path; The stirred mixture is formed into the above-mentioned predetermined layer shape.

[0040] In this way, even if the laminated composite raw material is formed by sequentially laminating one side porous layer, one side glass fiber layer having a plurality of glass fibers, a urethane foam layer, the other side glass fiber layer having a plurality of glass fibers, and the other side porous layer, the same effects as those of the invention described in claim 1 can be achieved more specifically.

[0041] According to claim 3 of the present invention, in the automotive sound absorber according to claim 1 or 2, Each of the multiple mixed components is characterized in that the mixed body is one of multiple three-dimensional components formed by cutting a laminated composite raw material, which is made by laminating a porous layer, a thermosetting resin layer, and a glass fiber layer having multiple glass fibers, in the thickness direction and at intervals into a three-dimensional shape, and the mixed glass fiber portion is made of multiple glass fibers extending from the corresponding portion of the glass fiber layer in one of the three-dimensional components as a result of the cutting.

[0042] According to this, even if each mixing body of the multiple mixing elements is formed by one of multiple three-dimensional elements obtained by cutting a laminated composite raw material configured as described above in its thickness direction at intervals into a three-dimensional shape, and each mixed glass fiber portion is formed by multiple glass fibers extending from the corresponding portion of the glass fiber layer in any one of the above-mentioned three-dimensional elements as a result of the above-mentioned cutting, the same effect as the invention described in claim 1 or 2 can be achieved.

[0043] According to claim 4 of the present invention, in the automotive sound absorber according to any one of claims 1 to 3, In addition to the multiple mixing elements and binders, cotton fiber The device is provided with a fiber optic member, The agitated mixture comprises a plurality of mixing members and cotton fiber The fiber material is dispersed and mixed in a binder, cotton fiber a fiber member, along with the mixed glass fiber portion of each of a plurality of mixing members, located within the at least one labyrinth path; When multiple mixed materials are designated as A and cotton fiber material is designated as B , the mixture based on the mass of B above relative to the mass of A above The sum ratio A / B is the sum of the at least one labyrinth path and the at least one labyrinth path. cotton fiber The glass fiber member and the mixed glass fiber portion of each of the plurality of mixed members are configured to reduce noise having frequencies within a predetermined frequency band.

[0044] According to this, the sound absorber for an automobile includes, in addition to a plurality of mixing components and a binder, , mixed According to the ratio cotton fiber The number of mixing members in the sound absorber for an automobile is determined based on the mixing ratio. cotton fiber Fiber materials mass fraction of It has decreased by only cotton fiber The fiber member is significantly lighter than the multiple mixing members.

[0045] Therefore, the total weight of the plurality of mixed materials used in the automotive sound absorber is determined according to the mixing ratio. cotton fiber The decrease is due to the fiber components.

[0046] In addition, a plurality of mixing members A and cotton fiber Fiber materials The mass of B relative to the mass of A B Mixture based on mass As described above, the combination ratio A / B is set so as to reduce noise having frequencies within a predetermined frequency band in combination with at least one maze-like path and the cotton-like fiber member and the mixed glass fiber portion of each of the multiple mixing members within the at least one maze-like path.

[0047] Accordingly, when noise is incident on one side of the automotive sound absorber, noise having a frequency within a predetermined frequency band moves along the labyrinth shape of at least one labyrinth path under the above-mentioned mixing ratio, and cotton fiber The vibration energy due to collisions with the fiber member and each mixed glass fiber portion can be very effectively reduced along with the loss of vibration energy. This can further improve the effects of the invention described in any one of claims 1 to 3. In this way, the automotive sound absorber with the above-mentioned configuration can exhibit even better sound absorbing performance.

[0048] According to claim 5 of the present invention, in the automotive sound absorber according to claim 4, The predetermined frequency band is characterized by shifting to a lower frequency band side or a higher frequency band side in response to an increase or decrease in the mixing ratio A / B.

[0049] With this configuration, the predetermined frequency band shifts toward the high frequency band as the mixing ratio A / B decreases, making it possible to provide an automotive sound absorber that exhibits excellent sound absorption performance mainly against noise having frequencies in the high frequency band.

[0050] Furthermore, since the specified frequency band shifts toward the lower frequency band as the mixing ratio A / B increases, it becomes possible to provide an automotive sound absorber that exhibits excellent sound absorption performance mainly against noise having frequencies in the low to medium frequency bands.

[0051] According to claim 6 of the present invention, in the automotive sound absorber according to any one of claims 1 to 5, The laminated composite raw material is characterized by being made from a laminated composite part to be discarded that has been mounted on an automobile or a laminated composite part for an automobile that is to be discarded due to poor quality.

[0052] This allows laminated composite parts that have been installed in automobiles and are to be discarded or laminated composite parts for automobiles that are to be discarded due to poor quality to be recycled and effectively used for manufacturing automobile sound absorbers, without being wasted, which can bring about a great economic effect in addition to the effects of the invention described in any one of claims 1 to 5.

[0053] According to claim 7 of the present invention, in the automotive sound absorber according to any one of claims 1 to 6, Each of the plurality of mixing elements is a first mixing element, The plurality of pulverized raw materials having the linear shape among the plurality of pulverized raw materials are provided as a plurality of second mixing members, The stirred mixture is formed by stirring and mixing a plurality of first mixing members and a plurality of second mixing members in a binder to form a dispersed state, The plurality of second mixing elements are characterized by being located within the at least one labyrinthine path together with the mixed glass fiber portions of each of the plurality of first mixing elements.

[0054] According to this configuration, the second mixing elements, together with the mixed glass fiber portions of the first mixing elements, are located within at least one labyrinth-like path. Therefore, when noise enters the automotive sound absorber from one side, the noise travels along the labyrinth shape of the at least one labyrinth-like path and collides with the second mixing elements and the mixed glass fiber portions within the at least one labyrinth-like path, resulting in excellent reduction of vibrational energy. As a result, the effects of the invention described in any one of claims 1 to 6 can be further improved.

[0055] According to claim 8 of the present invention, in the automotive sound absorber according to any one of claims 1 to 3, the porous layer of the laminated composite base material has porous fibers; Each of the plurality of first mixing members has a corresponding portion of the porous layer in its mixing body, Each of the plurality of mixing members is formed so that a mixed porous fiber portion made of a plurality of porous fibers extends from the corresponding portion of the mixing body corresponding to the porous layer as the grinding proceeds, The mixed porous fiber portion of each of the plurality of mixing elements is characterized by being located in a labyrinth-like path together with the glass fiber portion of each of the plurality of mixing elements.

[0056] According to this configuration, the mixed porous fiber portion of each of the plurality of mixing elements is located in at least one labyrinthine path together with the mixed glass fiber portion of each of the plurality of mixing elements.

[0057] Therefore, when noise enters the automotive sound absorber from one side, the noise travels along the labyrinth shape of at least one labyrinth path and collides with each mixed glass fiber section and each mixed porous fiber section within the at least one labyrinth path, resulting in extremely effective reduction of vibration energy, which further improves the effects of the invention as defined in any one of claims 1 to 3.

[0058] According to claim 9 of the present invention, in the automotive sound absorber according to claim 7, The porous layer of the laminated composite base material has a plurality of porous fibers; Each of the plurality of first mixing members has a corresponding portion of the porous layer in its mixing body, Each of the plurality of first mixing members is formed so that a mixed porous fiber portion made of a plurality of porous fibers extends from the corresponding portion of the mixing body corresponding to the porous layer as the mixing body is pulverized, The mixed porous fiber portion of each of the plurality of first mixing elements is characterized by being located within the at least one labyrinth-like path together with the mixed glass fiber portion of each of the plurality of first mixing elements and the plurality of second mixing elements.

[0059] According to this configuration, the mixed porous fiber portion of each of the plurality of first mixing members is located in the labyrinth-like path together with the mixed glass fiber portion of each of the plurality of first mixing members and the plurality of second mixing members.

[0060] Therefore, when noise enters the automotive sound absorber from one side, the noise travels along the labyrinth shape of at least one labyrinth path and collides with the mixed glass fiber sections, mixed porous fiber sections, and second mixing elements within the at least one labyrinth path, resulting in extremely effective reduction of vibration energy. As a result, the effects of the invention as defined in any one of claims 1 to 3 can be further improved.

[0061] According to claim 10 of the present invention, in the automotive sound absorber according to any one of claims 1 to 9, The mixing body of each of the plurality of mixing elements is characterized in that the larger it is, the lower the air permeability is set to reduce noise having frequencies within the low-to-mid frequency band, and the smaller it is, the higher the air permeability is set to reduce noise having frequencies in the high frequency band.

[0062] According to this, the larger the mixed body, the lower the air permeability so as to reduce noise having frequencies in the low-to-mid frequency band. Also, the smaller the mixed body, the higher the air permeability so as to reduce noise having frequencies in the high frequency band. Therefore, by adjusting the air permeability by changing the size of each mixed body, it is possible to provide an automotive sound absorber that can exhibit excellent sound absorbing performance against noise having frequencies in the low-to-mid frequency band and high frequency band.

[0063] According to claim 11, the floor silencer for an automobile according to the present invention comprises: The device is mounted from inside the vehicle compartment along the floor wall of the vehicle compartment (10) of an automobile having at least one of an electric motor (50) and an engine (E) as a prime mover.

[0064] In this floor silencer, a plurality of mixing elements and a binder; The plurality of mixing members are each formed by a mixing body, which is a pulverized raw material having a three-dimensional shape among a plurality of pulverized raw materials obtained by pulverizing a laminated composite raw material, which is formed by laminating a porous layer, a thermosetting resin layer, and a glass fiber layer having a plurality of glass fibers, into various shapes including at least a three-dimensional shape and a linear shape, and which is formed by both the mixing body and a mixed glass fiber portion made of a plurality of glass fibers that extend from a portion of the mixing body corresponding to the glass fiber layer as a result of the pulverization, the mixing body and the mixed glass fiber portion of each of the plurality of mixing members are stirred and mixed in a dispersed state in the binder to form a stirred mixture together with the binder, The stirred mixture comprises at least one labyrinth-like path formed between each of the plurality of mixing bodies of the plurality of mixing elements that face each other, the labyrinth-like path having the mixed glass fiber portion positioned therein, The mixture is formed into the predetermined layer shape.

[0065] This makes it possible to provide a floor silencer for an electric vehicle, a gasoline vehicle, a hybrid vehicle, or the like, which can achieve the effects of the invention described in claim 1.

[0066] According to claim 12 of the present invention, in the automotive floor silencer according to claim 11, In addition to the multiple mixing elements and binders, cotton fiber The device is provided with a fiber optic member, The stirred mixture is obtained by stirring and mixing a plurality of mixing members and cotton-like fiber members with a binder in a dispersed state, When multiple mixed materials are designated as A and cotton-like fiber material is designated as B, , the mixture based on the mass of B above relative to the mass of A above The combining ratio A / B is characterized by being set so as to reduce noise having frequencies within a predetermined frequency band.

[0067] This makes it possible to provide a floor silencer for automobiles such as electric vehicles, gasoline vehicles, and hybrid vehicles that can achieve the same effects as the invention described in claim 11 while also achieving the effects of the invention described in claim 4.

[0068] According to a thirteenth aspect of the present invention, in the automotive floor silencer according to the twelfth aspect, The predetermined frequency band is characterized by shifting to a lower frequency band side or a higher frequency band side in response to an increase or decrease in the mixing ratio A / B.

[0069] This makes it possible to provide a floor silencer for automobiles such as electric vehicles, gasoline vehicles, and hybrid vehicles that can achieve the same effects as the invention described in claim 12 while also achieving the effects of the invention described in claim 5.

[0070] According to a fourteenth aspect of the present invention, in the floor silencer for an automobile according to any one of the eleventh to thirteenth aspects, The laminated composite raw material is characterized in that it comprises a laminated composite part that has been installed in a vehicle or is to be discarded due to poor quality.

[0071] This makes it possible to provide a floor silencer for automobiles such as electric vehicles, gasoline vehicles, or hybrid vehicles that can achieve the same effects as the invention described in any one of claims 11 to 13 while also achieving the effects of the invention described in claim 6.

[0072] According to claim 15, the present invention provides: 11~ 14. The floor silencer for an automobile according to any one of claims 14 to 14, Each of the plurality of mixing elements is a first mixing element, The plurality of pulverized raw materials having the linear shape among the plurality of pulverized raw materials are provided as a plurality of second mixing members, The stirred mixture is formed by stirring and mixing a plurality of first mixing members and a plurality of second mixing members in a binder to form a dispersed state, The plurality of second mixing elements are characterized by being located within the at least one labyrinth path along with the plurality of mixed glass fiber portions of each of the plurality of first mixing elements.

[0073] According to this configuration, claims 11~ It is possible to provide a silencer for automobiles such as electric vehicles, gasoline vehicles, and hybrid vehicles that can achieve the same effects as the invention described in any one of claims 14 while also achieving the effects of the invention described in claim 7.

[0074] According to claim 16 of the present invention, in the automotive floor silencer according to any one of claims 11 to 15, The porous layer of the laminated composite base material has a plurality of porous fibers; Each of the plurality of mixing members has a corresponding portion in its mixing body corresponding to the porous layer, Each of the plurality of mixing members is formed so that a mixed porous fiber portion made of a plurality of porous fibers extends from the corresponding portion of the mixing body corresponding to the porous layer as the grinding proceeds, The mixed porous fiber portion of each of the plurality of mixing elements is characterized by being located in a labyrinth-like path together with the glass fiber portion of each of the plurality of mixing elements.

[0075] This makes it possible to provide a floor silencer for automobiles such as electric vehicles, gasoline vehicles, or hybrid vehicles that can achieve the same effects as the invention described in any one of claims 11 to 15 while also achieving the effects of the invention described in claim 8.

[0076] According to claim 17, the present invention provides the floor silencer for an automobile according to claim 15, The porous layer of the laminated composite base material has a plurality of porous fibers; Each of the plurality of mixing members has a corresponding portion in its mixing body corresponding to the porous layer, Each of the plurality of mixing members is formed so that a mixed porous fiber portion made of a plurality of porous fibers extends from the corresponding portion of the mixing body corresponding to the porous layer as the grinding proceeds, The mixed porous fiber portion of each of the plurality of mixing elements is located in a labyrinth-like path together with the glass fiber portion of each of the plurality of mixing elements and the plurality of mixing elements.

[0077] This makes it possible to provide a floor silencer for automobiles such as electric vehicles, gasoline vehicles, and hybrid vehicles that can achieve the same effects as the invention described in claim 15 while also achieving the effects of the invention described in claim 9.

[0078] According to claim 18 of the present invention, in the automotive floor silencer according to any one of claims 11 to 17, The mixing body of each of the plurality of mixing elements is characterized in that the larger it is, the lower the air permeability is set to reduce noise having frequencies within the low-to-mid frequency band, and the smaller it is, the higher the air permeability is set to reduce noise having frequencies in the high frequency band.

[0079] This makes it possible to provide a floor silencer for automobiles such as electric vehicles, gasoline vehicles, or hybrid vehicles that can achieve the same effects as the invention described in any one of claims 11 to 17 while also achieving the effects of the invention described in claim 10.

[0080] According to claim 19 of the present invention, in the automotive floor silencer according to any one of claims 11 to 18, The vehicle is provided with at least one of an electric motor and an engine as a prime mover, Each mixing body of the plurality of mixing elements is characterized in that its size is set to reduce noise having frequencies in the low to mid frequency range.

[0081] This makes it possible to provide an automobile floor silencer that can achieve the same effects as the invention described in any one of claims 11 to 18, while exhibiting excellent sound absorption performance for noise generated by the engine that has frequencies in the low to mid frequency range.

[0082] According to claim 20 of the present invention, in the automotive floor silencer according to any one of claims 11 to 18, The vehicle is equipped with a battery set having a group of batteries arranged along the underside of a floor wall, the battery set using at least one of an electric motor and an engine as a prime mover, and supplying power to the electric motor, Each mixing body of the plurality of mixing elements is characterized by its size being set to reduce noise having frequencies in the low-to-mid frequency range and the high frequency range.

[0083] This makes it possible to provide an automobile floor silencer that achieves the same effects as the invention described in any one of claims 11 to 18, while having excellent sound absorption performance against noise having frequencies in the low- to mid-frequency range and high-frequency range, in other words, noise having frequencies in the low- to mid-frequency range generated from the road and noise having frequencies in the high-frequency range generated from the battery group.

[0084] The symbols in parentheses for each of the above means indicate the corresponding relationship with the specific means described in the embodiments to be described later. [Brief explanation of the drawings]

[0085] [Figure 1] 1 is a schematic, partially cutaway, side view of an automobile to which a first embodiment of an automobile floor silencer according to the present invention is applied. [Figure 2] FIG. 2 is an enlarged side view of the floor silencer of FIG. 1. [Figure 3] 3 is a partially cutaway enlarged cross-sectional view of the floor silencer of FIG. 2. FIG. [Figure 4] FIG. 3 is an enlarged, partially cutaway side view of a disposal member in the first embodiment. [Figure 5] FIG. 2(a) is a side view of the first mixing member, and FIG. 2(b) is a diagram showing an example of each of the second mixing members. [Figure 6] FIG. 2 is a partially cutaway enlarged cross-sectional view illustrating a noise passage path inside the floor silencer. [Figure 7] 4 is a graph showing frequency characteristics of road noise in the first embodiment. [Figure 8] 4 is a graph showing frequency characteristics of engine noise in the first embodiment. [Figure 9] 4 is a graph showing frequency characteristics of sound absorption coefficients of an example sample and a comparative sample in the first embodiment. [Figure 10] 1 is a schematic, partially cutaway, side view of an automobile to which a second embodiment of an automobile floor silencer according to the present invention is applied. [Figure 11] 10 is a graph showing frequency characteristics of sound absorption coefficients of an example sample and a comparative sample in the second embodiment. [Figure 12] FIG. 10 is an enlarged, partially cutaway cross-sectional view showing a main part of a third embodiment of an automotive floor silencer according to the present invention. [Figure 13] FIG. 10 is a partially cutaway plan view showing a disposal member, which is a main part of a fourth embodiment of an automotive floor silencer according to the present invention, along with its grid-shaped break lines. [Figure 14] 14 is a side view showing the disposal member of FIG. 13 along its thickness direction cutting line. DETAILED DESCRIPTION OF THE INVENTION

[0086] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. (First embodiment) Fig. 1 shows a first embodiment in which the present invention is applied to an automobile. The automobile is a type of automobile that uses gasoline as fuel (hereinafter referred to as a gasoline automobile). The gasoline automobile is equipped with an engine E, and the engine E is installed in an engine room ER (see Fig. 1) of the gasoline automobile.

[0087] The gasoline-powered automobile has a passenger compartment 10, which is formed in the gasoline-powered automobile so as to be positioned adjacent to an engine compartment ER via a dash panel DP.

[0088] The gasoline-powered automobile has left and right front seats 20a (only the left front seat 20a is shown in Fig. 1) and left and right rear seats 20b (only the left rear seat 20b is shown in Fig. 1) arranged in a passenger compartment 10. In Fig. 1, the symbol H indicates a steering wheel, the symbol FP indicates a floor panel of the gasoline-powered automobile, and the symbol FS indicates a floor seat.

[0089] The gasoline-powered automobile also has left and right front wheels FW and left and right rear wheels RW. The left and right front wheels FW are supported on left and right end portions of a front wheel shaft 30a, and the left and right rear wheels RW are supported on left and right end portions of a rear wheel shaft 30b.

[0090] As shown in Fig. 1, the gasoline-powered automobile is equipped with a floor silencer S according to the present invention. In this first embodiment, the floor silencer S is mounted between a floor panel FP and a floor sheet FS so as to fit along the upper surface of the floor panel FP as a silencer for effectively absorbing noise having low-to-mid frequency bands. In this first embodiment, noise is also referred to as "noise."

[0091] As shown in either FIG. 1 or FIG. 2, the floor silencer S includes a front silencer portion Sa, a rear silencer portion Sb, and a middle silencer portion Sc located between the front and rear silencer portions Sa and Sb.

[0092] As shown in Figure 1, the front silencer part Sa is mounted on the front portion FPa of the floor panel FP, and the front end part Sd of the front silencer part Sa extends along the lower end part of the dash panel DP.

[0093] Meanwhile, the rear silencer portion Sb is mounted on the rear portion FPb of the floor panel FP. The middle silencer portion Sc is formed in a generally inverted U shape so as to fit on the middle protrusion FPc (see FIG. 1) of the floor panel FP, and the middle silencer portion Sc is formed integrally with the front and rear silencer portions Sa and Sb between them.

[0094] Here, the configuration of the floor silencer S will be described in detail. As will be described later, the floor silencer S is composed of a plurality of mixing elements P, a plurality of mixing elements Q, and a thermosetting resin binder U (adhesive) (see FIG. 3). The plurality of mixing elements P or the plurality of mixing elements Q are formed from discarded parts 100 (see FIG. 4) as will be described later. Urethane is used as the thermosetting resin that is the material for forming the binder U. In the following, in this first embodiment, the mixing element P will also be referred to as the first mixing element P, and the mixing element Q will also be referred to as the second mixing element Q.

[0095] The discarded part 100 is a roof part of an automobile that is used as a laminated composite raw material for manufacturing the floor silencer S. In the first embodiment, the discarded part 100 may be, for example, a roof part that has been installed in an automobile that is to be repaired or scrapped, or a newly manufactured roof part that is subject to quality defects.

[0096] As shown in FIG. 4, the discarded part 100 is configured by laminating a surface layer 110, a glass fiber layer 120, a urethane foam layer 130, a glass fiber layer 140, and a backing layer 150.

[0097] In the discarded part 100, the skin layer 110 is formed in a layer shape using a nonwoven fabric formed by intertwining multiple fibers without weaving or knitting them. The glass fiber layer 120 is formed in a layer shape by mixing multiple glass fibers with an adhesive, intertwining the multiple glass fibers, and allowing the adhesive to harden. In this first embodiment, the glass fiber layer 120 will be referred to as the skin layer side glass fiber layer 120 hereinafter.

[0098] The skin layer side glass fiber layer 120 is laminated between the skin layer 110 and the urethane foam layer 130. As a result, the skin layer side glass fiber layer 120 plays a role in reinforcing the strength of the skin layer 110 and the urethane foam layer 130 with the elasticity and rigidity of the entangled glass fibers.

[0099] The urethane foam layer 130 is formed into a layer of urethane foam. Similar to the skin-side glass fiber layer 120, the glass fiber layer 140 is formed into a layer by mixing a plurality of glass fibers with an adhesive, entangling the glass fibers with each other, and allowing the adhesive to harden. In the first embodiment, the glass fiber layer 140 will be referred to as the backing-side glass fiber layer 140 hereinafter.

[0100] The backing layer-side glass fiber layer 140 is laminated between the urethane foam layer 130 and the backing layer 150, and the backing layer-side glass fiber layer 140 serves to reinforce the strength of the urethane foam layer 130 and the backing layer 150 by using at least one of the elasticity and rigidity of the entangled glass fibers. The backing layer 150 is formed in a layered form using nonwoven fabric. The thickness of the backing layer 150 is set thinner than the thickness of the surface layer 110.

[0101] As shown in Fig. 5(a), each of the plurality of first mixture members P is composed of a mixed main body Pa and a plurality of mixed fiber portions 111, 151, 121, 141. Here, the plurality of mixed fiber portions 111, 151 (the plurality of nonwoven fabric fiber portions 111, 151) are each formed of a plurality of fibers (nonwoven fabric fibers) extending, for example, in a whisker-like manner from portions of the mixed main body Pa corresponding to the surface layer 110 and the back skin layer 150. Also, the plurality of mixed fiber portions 121, 141 (the plurality of glass fiber portions 121, 141) are each formed of a plurality of fibers (glass fibers) extending, for example, in a whisker-like manner from portions of the mixed main body Pa corresponding to the surface layer side glass fiber layer 120 and the back skin layer side glass fiber layer 140.

[0102] As shown in FIG. 5(b), each of the second mixing members Q is made up of short wires (for example, short fibers) or thin pieces.

[0103] The plurality of first mixing members P and the plurality of second mixing members Q configured in this manner are formed as follows. However, the first mixing members P and the second mixing members Q are each formed in the number required for manufacturing the floor silencer S. Accordingly, the discarded parts 100 are prepared in the number required for manufacturing the floor silencer S.

[0104] The discarded parts 100 thus prepared are first crushed by a crusher (not shown) to form a plurality of crushed raw materials (not shown). Each of the plurality of crushed raw materials has a size within a range of, for example, 5 mm to 100 mm.

[0105] The plurality of crushed raw materials are then crushed by a crusher (not shown) to form a plurality of crushed raw materials (not shown). Each of the plurality of crushed raw materials has a size within a range of, for example, 2 mm to 50 mm.

[0106] Here, due to the nature of grinding by a grinder, the shapes of the multiple pulverized raw materials are not uniform, but rather vary, such as three-dimensional shapes, short linear shapes, or thin flake shapes. Similarly, the sizes of the pulverized raw materials are also not uniform, but vary. The size of a three-dimensional or thin flake-shaped pulverized raw material is specified, for example, by the maximum length between two opposing portions of the outer shape of the pulverized raw material. Furthermore, the size of a linear pulverized raw material is specified, for example, by the length of the short fiber, if the pulverized raw material is a short fiber.

[0107] In other words, although the size of the raw material to be pulverized varies depending on the shape of the raw material, the size of the raw material to be pulverized is specified by the largest dimension of the outer shape of the raw material to be pulverized. Of the raw materials to be pulverized, those having a three-dimensional shape form the first mixing member P described above, and those having, for example, a short line shape or a thin piece shape form the second mixing member Q described above.

[0108] Here, the reason why the first mixing member P is composed of the mixed main body Pa and the plurality of mixed fiber portions 111, 151, 121, 141 as described above will be explained.

[0109] As described above, in the process of crushing and then pulverizing the disposal member 100, the materials forming the outer skin layer 110 and the inner skin layer 150 of the disposal member 100 are nonwoven fabrics. Therefore, when the mixed body Pa is formed by crushing the crushing member as described above, the multiple fibers forming the nonwoven fabrics that are the materials forming the outer skin layer 110 and the inner skin layer 150 of the mixed body Pa extend from the mixed body Pa as multiple mixed fiber portions 111, 151, for example, in a whisker-like shape, without being cut into individual mixed body Pa pieces.

[0110] Furthermore, in the process of crushing and then pulverizing the waste member 100 as described above, the materials forming the skin layer side glass fiber layer 120 and the backing layer side glass fiber layer 140 of the waste member 100 are a plurality of glass fibers. Therefore, when the mixed body Pa is formed by crushing the crushing member as described above, the plurality of glass fibers forming the skin layer side glass fiber layer 120 and the backing layer side glass fiber layer 140 of the mixed body Pa extend, for example, in a whisker-like shape from the mixed body Pa as a plurality of mixed fiber portions 121, 141 without being cut into individual mixed bodies at least in part of the fibers.

[0111] As can be seen from the above description, the mixing member Pa is composed of a mixed main body Pa and a plurality of mixed fiber portions 111, 151, 121, and 141.

[0112] Here, in manufacturing the floor silencer S, the plurality of first mixing members P and the plurality of second mixing members Q that constitute the floor silencer S are specified as follows.

[0113] In order for the floor silencer S to function as a silencer that effectively absorbs noise having frequencies in the low to medium frequency range, as described above, the size and number of the first mixture material P and the size and number of the second mixture material Q that are dispersedly stacked within the urethane U, as described below, are set so that the floor silencer S can effectively absorb noise having frequencies in the low to medium frequency range.

[0114] Furthermore, within the floor silencer S, as will be described later, a plurality of first mixing members P are laminated in a dispersed manner from the lower surface to the upper surface of the floor silencer S within the urethane U. Accordingly, a plurality of paths K are formed from the lower surface to the upper surface of the floor silencer S within the urethane U along between a plurality of mixing bodies Pa that face each other (see FIG. 6). Here, as illustrated in FIG. 6, the plurality of second mixing members Q are located dispersedly within the urethane U within the above-mentioned paths K together with the respective plurality of mixed fiber portions 111, 151, 121, 141 of the plurality of first mixing members P. Hereinafter, the above-mentioned plurality of paths K will each be referred to as a maze-like path K.

[0115] When noise enters the floor silencer S having the above-described configuration from its lower surface side, the noise enters both the mixing bodies Pa of the plurality of first mixing members P and the labyrinth-like paths K.

[0116] Here, since each mixing body Pa of the plurality of first mixing members P is a solid having a three-dimensional shape but has air permeability, noise passes through each mixing body Pa.

[0117] Furthermore, the mixed fiber portions 111, 151, 121, 141 of the multiple first mixing members P are located in a dispersed state within each labyrinthine path K. On the other hand, as described above, the multiple second mixing members Q each have a short line or strip shape, and are located in a dispersed state within each labyrinthine path K together with the multiple mixed fiber portions 111, 151, 121, 141 of the multiple first mixing members P. Therefore, noise can more easily pass through each labyrinthine path K formed by dispersing the multiple mixed fiber portions 111, 151, 121, 141 and second mixing members Q as described above, than through the mixed body Pa, which is a three-dimensional solid.

[0118] From the above, noise mainly passes through each labyrinth-like path K via each mixed fiber portion 111, 151, 121, 141 and each mixing member Q.

[0119] In this way, in the process in which the noise passes through each maze-like path K, each maze-like path K plays a role in consuming the vibration energy of the noise by making the noise travel along its maze shape.

[0120] Moreover, as described above, the noise traveling along each maze-like path K moves forward while colliding with each mixed fiber section 111, 151, 121, 141 and each mixing member Q. Accordingly, each of the multiple fibers in each mixed fiber section 111, 151, 121, 141 and each mixing member Q vibrates in response to the collision with the noise, thereby consuming the vibration energy of the noise.

[0121] In other words, each labyrinth path K, in combination with each of the plurality of fibers of each of the mixed fiber sections 111, 151, 121, 141 and each of the mixing members Q, plays a role in reducing the noise by consuming the vibration energy of the noise.

[0122] Based on the above-described noise propagation configuration in the floor silencer S, in the first embodiment, in order for the floor silencer S to effectively absorb noise having frequencies in the low-to-mid frequency band, each mixing body Pa of the plurality of first mixing members P is formed from, for example, a pulverized raw material having a three-dimensional shape and a size of 15 mm or more among the plurality of pulverized raw materials. Also, each of the plurality of second mixing members Q is formed from, for example, a pulverized raw material having a linear or flake shape and a size of 5 mm or less among the plurality of pulverized raw materials formed as described above.

[0123] The size of each mixing body Pa and the size of each second mixing member Q are set to 15 mm or more and 5 mm or less, respectively, but are not limited to this, and the size of each mixing body Pa and the size of each second mixing member Q may be any size that satisfies the noise propagation configuration for the floor silencer S as described above.

[0124] Here, we will explain the manufacturing method of the floor silencer S. The floor silencer S is manufactured using a plurality of first mixing members P and a plurality of second mixing members Q formed as described above, and urethane U, as follows.

[0125] The plurality of first mixing components P and the plurality of second mixing components Q are introduced into a mixer (not shown) together with the urethane U in a liquid state. The plurality of first mixing components P and the plurality of second mixing components Q introduced in this manner are stirred and mixed in the urethane U by the mixer, and as the urethane U hardens, they are formed into a stirred mixture. The stirred mixture is formed so as to have a shape in which the plurality of first mixing components P and the plurality of second mixing components Q are layered in a dispersed manner within the urethane U.

[0126] The stirred mixture formed as described above is poured between the upper and lower dies of a press die (not shown). The stirred mixture thus poured is then press-molded into a predetermined layer shape corresponding to the three-dimensional shape of the floor silencer S by lowering the upper die toward the lower die while spraying steam between the upper and lower dies of the press die using a steam generator (not shown). The thickness of the floor silencer S is, for example, 25 mm. Note that the thickness of the floor silencer S is not particularly limited to 25 mm, and may be any normal thickness for floor silencers installed in various automobiles.

[0127] In this way, the floor silencer S (see FIG. 2) is manufactured. The floor silencer S has a laminated structure in which a plurality of first mixture members P and a plurality of second mixture members Q are dispersedly laminated in a urethane U, as shown in FIG.

[0128] According to this stacking configuration, each of the above-mentioned maze-like paths K is formed within the urethane U between each of the opposing mixing bodies Pa, from the lower surface side to the upper surface side of the floor silencer S, as illustrated in Figure 6.

[0129] In addition, the nonwoven fiber sections 111, 151 and the glass fiber sections 121, 141 extending from the opposing mixing bodies Pa, as well as the second mixing members Q located between the opposing mixing bodies Pa, are each dispersed within the maze-like path K.

[0130] In this manner, the floor silencer S is manufactured as a silencer that can effectively absorb noise having frequencies in the low and medium frequency ranges.

[0131] In the first embodiment configured as described above, the floor silencer S is configured as follows so as to exhibit excellent sound absorption performance against noise having frequencies in the low and medium frequency bands, as described above. (1) As shown in FIG. 3, the floor silencer S is formed to have a layered structure in which a plurality of mixing members P and a plurality of mixing members Q are layered in a dispersed manner within a urethane U. (2) As described above, the shape and size of the mixing body Pa and the shape and size of the second mixing member Q are set so as to ensure excellent sound absorption performance of the floor silencer S. (3) In the floor silencer S, a plurality of labyrinth-like paths K are formed between a plurality of opposing mixing bodies Pa in the urethane U. Furthermore, the plurality of mixed fiber portions 111, 141, 121, 141 of each first mixing member P and each second mixing member Q are dispersedly positioned within each labyrinth-like path K.

[0132] With such a floor silencer S configured, when the gasoline automobile is put into a forward running state, for example, the gasoline automobile starts running forward with the left and right front wheels FW and left and right rear wheels RW rotating along the road surface L (see FIG. 1) as the engine E starts. Once the gasoline automobile starts running in this way, it moves forward with the left and right front wheels FW and left and right rear wheels RW rotating along the road L.

[0133] In this forward traveling state, when road noise is generated from the road surface L via both the left and right front wheels FW and both the left and right rear wheels RW, the road noise mainly travels through the floor panel FP, passes through parts of the floor silencer S other than the front end Sd, the rear silencer portion Sb, and the middle silencer portion Sc, and travels toward the interior of the vehicle compartment 10. Here, a portion of the road noise travels through both the left and right rear wheels RW and the lower end of the dash panel DP, and then travels toward the interior of the vehicle compartment 10 through the front end Sd of the front silencer portion Sa.

[0134] As mentioned above, the road noise that travels as described above has a frequency in the low-to-mid frequency range. The road noise has frequency characteristics in its sound pressure level as shown in the graph of Fig. 7. The graph shows that noise (road noise) with frequencies in the low-to-mid frequency range (100 Hz to 1000 Hz) has a high sound pressure level.

[0135] The floor silencer S has the above-described configuration and exhibits excellent sound absorption performance against road noise. Therefore, road noise having frequencies in the low-to-mid frequency range can be effectively reduced by the front silencer portion Sa, rear silencer portion Sc, and center silencer portion Sc of the floor silencer S.

[0136] In other words, road noise that travels from the left and right front wheels FW into the vehicle interior 10 via the front end Sd of the floor silencer S, and road noise that travels into the vehicle interior 10 through parts other than the floor panel FP and the front end Sd of the floor silencer S, can be effectively absorbed by the floor silencer S. As a result, even when the gasoline-powered automobile is traveling forward, the occupants in the vehicle interior 10 can enjoy a comfortable ride without feeling uncomfortable due to road noise.

[0137] The noise generated by the engine E (hereinafter referred to as engine noise) is absorbed by the dash silencer DS (see Figure 1) attached along the dash panel DP, but the sound pressure level of the engine noise has frequency characteristics as shown in the graph in Figure 8. The graph shows that the sound pressure level is high over a wide frequency range (250 Hz to 4000 Hz).

[0138] The sound absorption performance of the floor silencer S in this first embodiment was measured by a reverberation chamber sound absorption coefficient test. For this measurement, a sample (hereinafter referred to as Experimental Sample 1) having the same configuration as the floor silencer S was prepared. In addition, for comparison with Experimental Sample 1, a sample (hereinafter referred to as Comparative Sample 2) made of a single-layer sound-absorbing material was prepared. The single-layer sound-absorbing material was made of a single nonwoven fabric layer having a thickness of 25 mm.

[0139] The sound absorption performance of the experimental sample 1 was measured by the sound absorption coefficient test. The measurement results were obtained as graph 1 shown in FIG. 9. Graph 1 is a graph showing the sound absorption coefficient of the experimental sample 1 in relation to frequency. Graph 1 has a peak value of the sound absorption coefficient at a frequency of 800 Hz (see symbol 1a in FIG. 9).

[0140] The sound absorption performance of Comparative Sample 2 was measured by the above-mentioned sound absorption coefficient test. The measurement results were obtained as Graph 2 shown in Fig. 9. Graph 2 is a graph showing the sound absorption coefficient of Comparative Sample 2 as a function of frequency.

[0141] Comparing graphs 1 and 2, it can be seen that the sound absorption coefficient of graph 1 is higher in the low-to-mid frequency range, i.e., the frequency range (400 Hz to 1000 Hz) that includes a frequency of 800 Hz, than the sound absorption coefficient of comparative graph 2. This means that experimental sample 1 has a higher sound absorption coefficient than comparative sample 2 in the low-to-mid frequency range.

[0142] Therefore, it can be seen that the working sample 1 can exhibit good sound absorption performance against the above-mentioned road noise in comparison with the comparative sample 2. This means that the floor silencer S has superior sound absorption performance compared to the comparative sample 1.

[0143] Here, we investigated the relationship between the sound absorption coefficient of the floor silencer S and the noise frequency using the size of the mixing body Pa of the first mixing member P as a parameter, and found that the peak value of the sound absorption coefficient shifts toward the low- to mid-frequency band as the size of the mixing body Pa increases, and shifts toward the high-frequency band as the size of the mixing body Pa decreases. Therefore, when mainly absorbing road noise, it was found that the size of the mixed body Pa should be increased so as to shift the peak value of the sound absorption coefficient toward the low-to-middle frequency range, for example, as shown in graph 1 of FIG. 9.

[0144] Furthermore, as described above, while investigating the relationship between the sound absorption coefficient of the floor silencer S and the frequency of noise using the size of the mixing body Pa of the first mixing member P as a parameter, the relationship between the size of the mixing body Pa, the air permeability, and the frequency of noise was also investigated. As a result, it was found that the larger the size of the mixing body Pa, the lower the air permeability of the mixing body Pa. This means that the floor silencer S can effectively absorb noise having frequencies within the low to mid frequency band. (Second embodiment) FIG. 10 shows a second embodiment in which the present invention is applied to an automobile. This automobile is a type of electric automobile. This electric automobile has a passenger compartment 10 similar to the gasoline-powered automobile described in the first embodiment. Furthermore, like the gasoline-powered automobile described above, this electric automobile is provided with front seats 20a on both the left and right sides within the passenger compartment 10 (only the left front seat 20a is shown in FIG. 10) and rear seats 20b on both the left and right sides (only the left rear seat 20b is shown in FIG. 10).

[0145] Furthermore, in this electric vehicle, similar to the gasoline vehicle described above, both left and right front wheels FW (only the left front wheel is shown in Figure 10) and both left and right rear wheels RW (only the left rear wheel is shown in Figure 10) are supported by front and rear wheel axles 30a, 30b, respectively, and the floor panel FP and floor sheet FS described in the first embodiment above are similarly arranged as the floor panel and floor sheet of the passenger compartment 10 in this second embodiment as well.

[0146] 1, the electric vehicle further includes a battery set 40, which is attached to a floor panel FP from its underside. Here, the battery set 40 has a casing 41 and a battery group (not shown) made up of a plurality of batteries housed in the casing 41. The casing 41 has an upper wall attached to the underside of the floor panel FP. In this second embodiment, the floor panel FP corresponds to the floor wall of the vehicle interior 10, and therefore the casing 41 is formed in a flat rectangular shape so as to fit along the floor wall (floor panel FP) of the vehicle interior 10.

[0147] The battery group described above is arranged in a casing 41, with each battery being arranged in the casing 41, and the battery group is connected to the electric motor 50 via an inverter IN (see FIG. 10) so as to be able to drive the electric motor 50. The electric motor 50 is supported on a part of the body of the electric vehicle directly above the axial center of the front wheel set 30a. The inverter IN is disposed in a position on the body of the electric vehicle near the electric motor 50, and is connected between the electric motor 50 and the battery group, adjusting the output of the battery group and supplying it to the electric motor 50.

[0148] The electric vehicle also includes, as its drive system, a transfer mechanism 60, a front differential mechanism 70, and a rear differential mechanism 80 in addition to the electric motor 50 described above.

[0149] The transfer mechanism 60 distributes and transmits the power generated by the rotation of the electric motor 50 to the front differential mechanism 70 and the rear differential mechanism 80. The transfer mechanism 60 is supported on another part of the vehicle body behind the electric motor 50.

[0150] The front differential mechanism 70 is mounted in the axial center of the front wheel shaft 30a, and transmits power differentially to both the left and right front wheels FR via the front wheel shaft 30a based on the distributed power from the transfer mechanism 60.

[0151] The rear differential mechanism 80 is mounted to the axial center of the rear wheel axle 30b. The rear differential mechanism 80 is connected to the transfer mechanism 70 via a propeller shaft 90, and the rear differential mechanism 80 receives distributed power from the transfer mechanism 70 via the propeller shaft 90. Accordingly, the rear differential mechanism 80 differentially transmits the distributed power from the propeller shaft 90 to both the left and right rear wheels RW via the rear wheel axle 30b.

[0152] The electric vehicle is equipped with a floor silencer S1 according to the present invention, as shown in Fig. 10. The floor silencer S1 is interposed between a floor panel FP and a floor sheet FS, and is mounted on the floor panel FP so as to face the battery set 40 across the floor panel FP.

[0153] As shown in FIG. 10, the floor silencer S1 includes a front silencer portion Se, a rear silencer portion Sf, and a middle silencer portion Sg, which correspond to the front silencer portion Sa, the rear silencer portion Sb, and the middle silencer portion Sc located between the front and rear silencer portions Sa and Sb described in the first embodiment.

[0154] Similar to the front silencer part Sa described in the first embodiment above, the front silencer part Se is mounted along the front portion FPa of the floor panel FP, as shown in Figure 10, and the front end part Sh of the front silencer part Se extends along the lower end part of the dash panel DP.

[0155] Meanwhile, the rear silencer portion Sf is mounted so as to fit on the rear portion FPb of the floor panel FP, similar to the rear silencer portion Sb described in the first embodiment. The middle silencer portion Sg is formed in a generally inverted U shape so as to fit on the middle protrusion FPc (see FIG. 10) of the floor panel FP, similar to the rear silencer portion Sc described in the first embodiment, and the middle silencer portion Sg is formed integrally with the front and rear silencer portions Se and Sf between them.

[0156] Here, the configuration of the floor silencer S1 will be described in detail. Similar to the floor silencer S described in the first embodiment, the floor silencer S1 is formed by press-molding an agitated mixture obtained by mixing and agitating a plurality of first mixing members P and a plurality of second mixing members Q with urethane U using the press mold so as to have the same three-dimensional shape as the floor silencer S1. However, in this second embodiment, in order to absorb noise having frequencies in the low-to-mid frequency band and high-frequency band, the size of each mixing body Pa of the plurality of first mixing members P is set to a size in the range of 10 mm to 20 mm, for example, to include a size range smaller than the size of the mixing body Pa in the first embodiment.

[0157] In the second embodiment, the size of each mixed body Pa is in the range of 10 mm to 20 mm, but it is not limited thereto, and the size of each mixed body Pa may be in any range that can effectively absorb noise having a frequency in the high frequency band as well as noise having a frequency in the low to medium frequency band. The other configurations are the same as those of the first embodiment.

[0158] In the second embodiment configured as described above, the floor silencer S1 is configured as follows so as to exhibit excellent sound absorption performance not only against noises having frequencies in the low and mid frequency bands, but also against noises having frequencies in the high frequency bands, as described above. (1) The floor silencer S1 is formed to have a layered structure in which a plurality of first mixture members P and a plurality of second mixture members Q are layered in a dispersed manner within a urethane U, similar to the example shown in FIG. (2) In order to absorb noise having frequencies ranging from the low-medium frequency band to the high frequency band, the size of each mixing body Pa of the multiple mixing members P is set to include a range of sizes smaller than the size of the mixing body Pa in the first embodiment, as described above. Furthermore, each of the multiple second mixing members Q has a short line shape or a strip shape and size similar to those in the first embodiment. Furthermore, the number of first mixing members P and the number of second mixing members Q, in combination with the size of the mixing body Pa in the second embodiment, the size of the mixing body Pa in the first embodiment, and the shape and size of the second mixing members Q described above, are set so as to ensure excellent sound absorption performance of the floor silencer S1 against noise having frequencies ranging from the low-medium frequency band to the high frequency band. (3) In the above-mentioned stacked structure in the floor silencer S1, a plurality of labyrinth-like paths K are formed in the same manner as in the first embodiment. Also, the plurality of mixed fiber portions 111, 141, 121, 141 of each first mixing member P and each second mixing member Q are located in a dispersed manner in each labyrinth-like path K, in the same manner as in the first embodiment.

[0159] With this configuration as a premise, when the electric vehicle starts moving, the batteries in the battery set 40 supply electric power to the electric motor 50 via the inverter, and the electric motor 50 starts. Accordingly, the power from the electric motor 50 is distributed by the transfer mechanism 60 to the front and rear differential mechanisms 70, 80.

[0160] Then, the front differential mechanism 70 transmits the distributed power from the transfer mechanism 60 to the left and right front wheels FW via the front wheel shaft 30a, and the rear differential mechanism 80 receives the distributed power from the transfer mechanism 60 via the propeller shaft 90 and transmits it to the left and right rear wheels RW via the rear wheel shaft 30b.

[0161] Accordingly, the electric vehicle starts moving forward, for example, with both left and right front wheels FW and both left and right rear wheels RW rotating along the road surface L (see FIG. 10). Having started moving in this way, the electric vehicle moves forward with both left and right front wheels FW and both left and right rear wheels RW rotating along the road L.

[0162] In this forward traveling state, when road noise is generated from the road surface L via both left and right front wheels FW or both left and right rear wheels RW, the road noise travels toward the interior of the vehicle compartment 10 via the floor silencer S1 instead of the floor silencer described in the first embodiment. Also, when the batteries and the inverter in the battery set 40 generate their respective noises as battery noise in conjunction with the supply of power to the electric motor 50, the battery noise travels toward the interior of the vehicle compartment 10 via the floor panel FP and the floor silencer S1.

[0163] Road noise that travels as described above has frequencies in the low to mid frequency range, while battery noise that travels as described above has frequencies in the high frequency range, as described above.

[0164] However, since the floor silencer S1 has the above-mentioned configuration, the floor silencer S1 has excellent sound absorption performance not only for noises having frequencies in the low and mid frequency range, but also for noises having frequencies in the high frequency range.

[0165] Therefore, road noise having frequencies in the low- to mid-frequency range and battery noise having frequencies in the high-frequency range can be effectively absorbed by the floor silencer S1. As a result, road noise having frequencies in the low- to mid-frequency range and battery noise having frequencies in the high-frequency range that are incident on the floor silencer S1 can be significantly reduced. As a result, even when the electric vehicle is traveling forward, passengers in the vehicle compartment 10 can enjoy a comfortable ride without feeling discomfort from both road noise having frequencies in the low- to mid-frequency range and battery noise having frequencies in the high-frequency range. Other effects are the same as those of the first embodiment.

[0166] The sound absorption performance of the floor silencer S1 in this second embodiment was measured by a reverberation chamber sound absorption coefficient test, as in the first embodiment. For this measurement, a sample (hereinafter referred to as Experimental Sample 3) having the same configuration as the floor silencer S1 was prepared. In addition, for comparison with Experimental Sample 3, a sample (hereinafter referred to as Comparative Sample 4) made of a single-layer sound-absorbing material was prepared. The single-layer sound-absorbing material was made of a single nonwoven fabric layer having a thickness of 25 mm.

[0167] The sound absorption performance of Example Sample 3 was measured by the sound absorption coefficient test. The measurement results were obtained as Graph 3 shown in FIG. 11. Graph 3 is a graph showing the relationship between the sound absorption coefficient of Example Sample 3 and frequency. Graph 3 has a peak value of the sound absorption coefficient near a frequency of 1000 Hz (see reference symbol 3a in FIG. 11). Graph 3 shows that the peak value has shifted to the high frequency band side compared to Graph 1 (see FIG. 9) described in the first embodiment.

[0168] The sound absorption performance of Comparative Sample 4 was measured by the above-mentioned sound absorption coefficient test. The measurement results were obtained as Graph 4 shown in Fig. 11. Graph 4 is a graph showing the sound absorption coefficient of Comparative Sample 4 as a function of frequency.

[0169] Comparing Graphs 3 and 4, it can be seen that the sound absorption coefficient of Experimental Sample 3 is higher than that of Comparative Sample 3 in the frequency range (630 Hz to 1600 Hz) that includes the frequency of Peak Value 3a in Graph 3. In other words, it can be seen that the sound absorption coefficient of Experimental Sample 3 is higher than that of Comparative Sample 4 not only in the low and mid frequency range but also in the high frequency range.

[0170] Therefore, it can be seen that the working sample 3 can exhibit superior sound absorption performance against road noise in the low-to-mid frequency range and battery noise in the high frequency range, compared with the comparative sample 4. This means that the floor silencer S1 has superior sound absorption performance compared to the comparative sample 4. (Third embodiment) FIG. 12 shows a main part of a third embodiment of a floor silencer according to the present invention. As shown in Fig. 12, the floor silencer in the third embodiment (hereinafter referred to as floor silencer S2) includes a fibrous material R in addition to the plurality of mixing members P described in the first embodiment. Note that the plurality of mixing members Q are not employed in this third embodiment.

[0171] In the third embodiment, the fiber member R is employed to ensure that the sound absorbing performance of the floor silencer S2 is excellent for noises having low to medium frequency bands, similar to the floor silencer S in the first embodiment, while also reducing the weight of the floor silencer S2. Accordingly, in the third embodiment, the fiber member R is formed of, for example, cotton-like felt fibers.

[0172] With this configuration as a premise, in manufacturing the floor silencer S2, a plurality of mixed materials P and fibrous materials R are put into the mixer described in the first embodiment together with the liquid urethane U described in the first embodiment, and are stirred and mixed by the mixer. As the urethane U hardens, the plurality of mixed materials P are dispersed and laminated together with the fibrous materials R within the urethane U. In this way, the floor silencer S2 is manufactured.

[0173] Here, when manufacturing the above-mentioned floor silencer S2, in order to make the sound absorption performance of the floor silencer S2 similar to that of the floor silencer S1 in the first embodiment and also to ensure that the floor silencer S2 is lightweight, the mixing ratio of the mixed material P and the fibrous material R is set to, for example, 70%:30%. The mixing ratio refers to the mixing ratio of the mixed material P and the fibrous material R based on the mass of the R relative to the mass of the P.

[0174] In the third embodiment, the mixture ratio of the mixed material P and the fibrous material R is set to 70%:30% as described above. However, this mixture ratio changes depending on the shape of the mixed body Pa of the mixed material P, the target values ​​of noise and vibration (NV target values) permissible for electric vehicles, and the target mass for reducing the weight of the floor silencer S2 in response to demands for weight reduction of electric vehicles. Therefore, the mixture ratio is not limited to 70%:30% as described above, and may be set depending on the shape of the mixed body Pa of the mixed material P, the target NV value for the electric vehicle, and the target mass for reducing the weight of the floor silencer S2.

[0175] According to the above-mentioned mixing ratio, the number of mixing members P is much smaller than the number of mixing members P in the first embodiment. Moreover, since the fiber member R is made of cotton-like felt fibers, it is much lighter than the mixing member P having the three-dimensional mixing body Pa. This means that the floor silencer S2 is much lighter than the floor silencer S in the first embodiment.

[0176] In the floor silencer S2 of the third embodiment, as described above, the plurality of mixed members P are laminated together with the fibrous member R in a dispersed manner within the urethane U. Therefore, in the floor silencer S2, a plurality of labyrinth-like paths K are formed passing through the mixing bodies Pa of the plurality of opposing mixed members P, as in the first embodiment, as illustrated in Fig. 12. Accordingly, the plurality of mixed fiber portions of each mixed member P are positioned dispersedly within each labyrinth-like path K. Furthermore, the fibrous material R is dispersed as a collection of cotton-like fibers between the mixing bodies Pa of the opposing mixing members P. Accordingly, the cotton-like felt fibers of the fibrous material R are dispersed in each labyrinth path K together with the multiple mixed fiber portions of each mixing member P. The other configurations are the same as those of the first embodiment.

[0177] In the third embodiment configured as described above, in the floor silencer S2, noise passing through each labyrinth-like path K moves along the labyrinth shape of each labyrinth-like path K, and is absorbed by the fiber material R, as in the first embodiment. Felt fibers The vibration energy of the fibers collides with the plurality of mixed fiber portions of each mixing member P. This reduces the noise due to the loss of vibration energy.

[0178] Moreover, in the third embodiment, the mixing member P and the fibrous member R are Mixture based on the mass of the above R against the mass The ratio is, for example, 70%:30% as mentioned above, so the floor silencer S2 is lightweight.

[0179] Therefore, the floor silencer S2 can be formed as a lightweight silencer that exhibits excellent sound absorbing performance for noises having frequencies in the low and mid frequency bands.

[0180] According to this, the floor silencer S2 can effectively absorb road noise having frequencies in the low-to-mid frequency range, as in the first embodiment, and as a result, even when the gasoline-powered automobile is traveling forward, the passengers in the passenger compartment 10 can enjoy a comfortable ride without feeling discomfort from the road noise.

[0181] Furthermore, as described above, the floor silencer S2 is formed as a lightweight silencer, which contributes to reducing the weight of the gasoline-powered automobile in which it is installed.

[0182] As described above, according to the third embodiment, the floor silencer S2, like the floor silencer S of the first embodiment, exhibits excellent sound absorption performance against noises having frequencies in the low to medium frequency band, thereby providing passengers with a comfortable riding experience, and can be provided as a floor silencer that can fully meet the demand for weight reduction in the mounted parts of the gasoline automobile.

[0183] Incidentally, we prepared several samples of floor silencer S2 in which only the mixing ratio of the mixed material P and the fiber material R was changed, and investigated how changing the mixing ratio affected the sound absorption characteristics of the samples. We found that as the mixing ratio of the fiber material R to the mixed material P increased, the peak value of the sound absorption coefficient in the frequency characteristics of the sound absorption coefficient shifted toward the high frequency band.

[0184] Furthermore, when we considered reducing the weight of the floor silencer S1 described in the second embodiment above, we found that if the mixing ratio of the mixed material P and the fibrous material R is set to 50%:50%, it is possible to provide a floor silencer that can ensure excellent sound absorption performance against noise having frequencies in the low, medium, and high frequency bands, similar to the floor silencer S1, and can also ensure lightweight performance similar to the floor silencer S2 described in the third embodiment.

[0185] Therefore, if the floor silencer S1 in the second embodiment is formed from a plurality of mixed materials P, fibrous materials R and urethane U, similar to the floor silencer S2 in the third embodiment, and the mixing ratio of the mixed materials P and the fibrous materials R is set to 50%:50%, the number of mixed materials P in the floor silencer will be significantly smaller than the number of mixed materials P in the floor silencer S1 in the second embodiment.

[0186] Therefore, a floor silencer formed as described above using multiple mixed materials P, fiber materials R and urethane U in the above-mentioned mixing ratio of 50%:50% can exhibit excellent sound absorption performance against noise having frequencies in the low, medium and high frequency bands, similar to the floor silencer S1 of the second embodiment, and can provide a floor silencer that is significantly lighter than the floor silencer S1 of the second embodiment. (Fourth embodiment) 13 shows a main part of a fourth embodiment of the floor silencer according to the present invention. In the floor silencer according to the fourth embodiment, the first mixing members P, the second mixing members Q, and the urethane U that constitute the floor silencer S according to the first embodiment are made up of a plurality of cutting members. As a result, the floor silencer according to the fourth embodiment is made up of a plurality of first mixing members P made up of a plurality of cutting members, and the second mixing members Q and the urethane U according to the first embodiment.

[0187] In the fourth embodiment, the plurality of cutting members, which are the plurality of first mixed members P, are formed as follows: The discarded part 100 described in the first embodiment is composed of the surface layer 110, the surface layer side glass fiber layer 120, the urethane foam layer 130, the back layer side glass fiber layer 140, and the back layer 150, as described above.

[0188] The discarded parts 100 thus configured are cut by a cutting machine (not shown) into a lattice pattern (see FIG. 13) along the direction of each arrow y (see FIG. 14), as shown in FIGS. 13 and 14. As a result, a plurality of first mixing members P, which are a plurality of cutting members, are each formed of a cutting body having the same rectangular parallelepiped shape and a plurality of fiber portions extending from the cutting body.

[0189] Here, the cutting body constitutes the mixing body Pa referred to in the first embodiment. Therefore, in the fourth embodiment, the cutting body is also referred to as the mixing body Pa. The mixing body Pa, which is the cutting body, has the same size as each mixing body Pa referred to in the first embodiment.

[0190] Furthermore, the plurality of fiber portions in the fourth embodiment correspond to the plurality of mixed fiber portions in the first embodiment, and are therefore also referred to as a plurality of mixed fiber portions in the fourth embodiment.

[0191] Furthermore, in the disposable part 100, the nonwoven fabrics forming the nonwoven fabric layers 110, 150 are aggregates of nonwoven fabric fibers, and therefore, as described above, when cutting the disposable part 100 into a grid pattern, the nonwoven fabric fibers of the nonwoven fabric layers 110, 150 are difficult to cut. For this reason, the multiple mixed fiber portions in the fourth embodiment are formed so as to extend, for example, as multiple whisker-like fibers from each cut surface of the mixed body P, which is the cutting body, as described above.

[0192] Furthermore, the plurality of glass fibers forming each of the glass fiber layers 120, 140 have significantly higher rigidity and elasticity than the nonwoven fabric layers 110, 150. Therefore, as described above, when cutting the discarded parts 100 into a lattice pattern, the collection of glass fibers in each of the glass fiber layers 120, 140 is even more difficult to cut, and as in the case of Fig. 7(a), they extend like whiskers from each mixing body Pa (cutting body Pa) of the mixing member P, which is the cutting member.

[0193] In the fourth embodiment, the plurality of second mixing members Q may be the plurality of second mixing members Q described in the first embodiment. Also, the plurality of second mixing members Q in the fourth embodiment may be a plurality of mixing members formed by crushing other discarded parts 100 with the crusher and then pulverizing the crushed parts with the crusher. Note that other configurations are the same as those of the first, second or third embodiment.

[0194] According to the fourth embodiment configured as described above, even if the above-mentioned cutting member is formed as a mixing body Pa in the first mixing member P and the multiple fibers extending from the cutting member are formed as a mixed fiber portion, the same effects as those described in the first, second or third embodiment can be achieved.

[0195] It should be noted that the present invention is not limited to the above-described embodiments, and various modifications such as those described below can be made. (1) In implementing the present invention, the present invention is not limited to the gasoline-powered vehicle described in the first embodiment and the electric vehicle described in the second embodiment, but may also be applied to a hybrid vehicle equipped with both an electric motor and an engine as prime movers.

[0196] In this case, a floor silencer S that can exhibit excellent sound absorbing performance against both road noise and battery noise may be disposed along the floor and wall of the vehicle interior of the hybrid vehicle. (2) In carrying out the present invention, the urethane U referred to in the above embodiments is not limited to this, and may be a binder made of a thermosetting resin. (3) In carrying out the present invention, the waste material referred to in each of the above embodiments is not limited to the configuration described in the first embodiment, but may also be a laminated composite material formed by laminating a porous layer, a thermosetting resin layer, and a glass fiber layer having a plurality of glass fibers. (4) In carrying out the present invention, the floor silencer is not limited to the floor silencer shown in FIG. 1 or FIG. 10, and the front silencer portion or the rear silencer portion of the floor silencer may be used as the floor silencer. (5) In carrying out the present invention, the present invention is not limited to the floor silencers in the above-described embodiments, but may be applied to various automobile sound absorbers or various automobile floor silencers. [Explanation of symbols]

[0197] 10...car compartment, 40...battery set, 50...electric motor, 100...discarded parts, 110...skin layer, 111, 121, 141, 151...mixed fiber portion, 120, 140...glass fiber layer, 130...urethane foam layer, 150...lining layer, DP...Dash panel, E...Engine, ER...Engine room, FP...Floor panel, FS...Floor sheet, K...Maze path, P...Mixed material, Pa...mixing body, R...fiber material, S, S1, S2...floor silencer, Sa...Front silencer part, Sb...Rear silencer part, Q...Mixing member, U...Binder.

Claims

1. A sound absorbing body for an automobile formed into a predetermined layer shape, a plurality of mixing elements and a binder; Each of the plurality of mixing members is made up of a plurality of pulverized raw materials obtained by pulverizing a laminated composite raw material, which is made by laminating a porous layer, a thermosetting resin layer, and a glass fiber layer having a plurality of glass fibers, into various shapes including at least a three-dimensional shape and a linear shape, and the three-dimensional pulverized raw materials are used as a mixing body, and a plurality of glass fibers extending from a portion of the mixing body corresponding to the glass fiber layer as a result of the pulverization are used as a mixed glass fiber portion, The mixing body and the mixed glass fiber portion of each of the plurality of mixing members are stirred and mixed in a dispersed state in the binder to form a stirred mixture together with the binder, The stirred mixture has at least one labyrinth-like path formed between a plurality of opposing mixing bodies among the plurality of mixing elements, the mixed glass fiber portion of each of the plurality of mixing elements is located within the at least one labyrinth path; The stirred mixture is formed into the predetermined layer shape to form a sound absorbing body for an automobile.

2. A sound absorbing body for an automobile formed into a predetermined layer shape, a plurality of mixing elements and a binder; Each of the plurality of mixing members is composed of a mixing body, a pulverized raw material having a three-dimensional shape among a plurality of pulverized raw materials obtained by pulverizing a laminated composite raw material, which is obtained by sequentially laminating a one-side porous layer, a one-side glass fiber layer having a plurality of glass fibers, a urethane foam layer, a other-side glass fiber layer having a plurality of glass fibers, and a other-side porous layer, into various shapes including at least a three-dimensional shape and a linear shape, and a plurality of glass fibers extending from a portion of the mixing body corresponding to at least one of the one-side glass fiber layer and the other-side glass fiber layer as a result of the pulverization, which forms a mixed glass fiber portion; The mixing body and the mixed glass fiber portion of each of the plurality of mixing members are stirred and mixed in a dispersed state in the binder to form a stirred mixture together with the binder, The stirred mixture has at least one labyrinth-like path formed between a plurality of opposing mixing bodies among the plurality of mixing elements, the mixed glass fiber portion of each of the plurality of mixing elements is located within the at least one labyrinth path; The stirred mixture is formed into the predetermined layer shape to form a sound absorbing body for an automobile.

3. 3. The sound absorber for an automobile according to claim 1, wherein each of the plurality of mixed elements is one of a plurality of three-dimensional elements obtained by cutting a laminated composite raw material, which is made by laminating a porous layer, a thermosetting resin layer, and a glass fiber layer having a plurality of glass fibers, in the thickness direction and at intervals into a three-dimensional shape, as the mixed body, and has a plurality of glass fibers extending from a portion of the one of the three-dimensional elements corresponding to the glass fiber layer as a result of the cutting as the mixed glass fiber portion.

4. In addition to the plurality of mixing elements and the binder, a cotton fiber element is provided, The stirred mixture is obtained by stirring and mixing the plurality of mixing members and the cotton fiber member in the binder in a dispersed state, the cotton fiber member is located within the at least one labyrinth path along with the mixed glass fiber portion of each of the plurality of mixing members; The sound absorber for an automobile described in any one of claims 1 to 3, characterized in that when the multiple mixed components are A and the cotton fiber component is B, the mixing ratio A / B based on the mass of B relative to the mass of A is set so as to reduce noise having frequencies within a predetermined frequency band in combination with the at least one maze-like path, the cotton fiber component within the at least one maze-like path, and the mixed glass fiber portion of each of the multiple mixed components.

5. 5. The sound absorber for an automobile according to claim 4, wherein the predetermined frequency band shifts toward a lower frequency band or a higher frequency band in response to an increase or decrease in the mixing ratio A / B.

6. The automotive sound absorber according to any one of claims 1 to 5, characterized in that the laminated composite raw material is made from a laminated composite part that has been installed in an automobile and is to be discarded, or a laminated composite part for an automobile that is to be discarded due to poor quality.

7. Each of the plurality of mixing elements is a first mixing element, The plurality of pulverized raw materials having the linear shape among the plurality of pulverized raw materials are provided as a plurality of second mixing members, the stirred mixture is formed by stirring and mixing the plurality of first mixing members and the plurality of second mixing members in the binder in a dispersed state, The sound absorbing body for an automobile described in any one of claims 1 to 6, characterized in that the plurality of second mixed elements are located within the at least one maze-like path together with the mixed glass fiber portion of each of the plurality of first mixed elements.

8. the porous layer of the laminated composite base material has a plurality of porous fibers; Each of the plurality of mixing members has a corresponding portion in its mixing body corresponding to the porous layer, each of the plurality of mixing members is formed so that a mixed porous fiber portion made of a plurality of porous fibers extends from the corresponding portion of the mixing body corresponding to the porous layer as the grinding proceeds; The mixed porous fiber portion of each of the plurality of mixing elements, together with the glass fiber portion of each of the plurality of mixing elements, is located within the at least one labyrinth-like path.

9. the porous layer of the laminated composite base material has a plurality of porous fibers; Each of the plurality of first mixing members has a corresponding portion of the porous layer in its mixing body, Each of the plurality of first mixing members is formed so that a mixed porous fiber portion made of a plurality of porous fibers extends from the corresponding portion of the mixing body corresponding to the porous layer as the mixing body is pulverized, The sound absorber for an automobile according to claim 7, characterized in that the mixed porous fiber portion of each of the plurality of first mixing elements, together with the mixed glass fiber portion of each of the plurality of first mixing elements and the plurality of second mixing elements, is located within the at least one labyrinth-like path.

10. The mixing body of each of the plurality of mixing elements is set so that the larger the mixing body, the lower the air permeability so as to reduce noise having frequencies in the low-to-mid frequency band, and the smaller the mixing body, the higher the air permeability so as to reduce noise having frequencies in the high frequency band. Sound absorbing body for an automobile according to any one of claims 1 to 9.

11. A floor silencer formed in a predetermined layer shape along a floor wall of a passenger compartment of an automobile equipped with at least one of an electric motor and an engine as a prime mover, and mounted from the inside of the passenger compartment, a plurality of mixing elements and a binder; Each of the plurality of mixing members is made up of a plurality of pulverized raw materials obtained by pulverizing a laminated composite raw material, which is made by laminating a porous layer, a thermosetting resin layer, and a glass fiber layer having a plurality of glass fibers, into various shapes including at least a three-dimensional shape and a linear shape, and the three-dimensional pulverized raw materials are used as a mixing body, and a plurality of glass fibers extending from a portion of the mixing body corresponding to the glass fiber layer as a result of the pulverization are used as a mixed glass fiber portion, The mixing body and the mixed glass fiber portion of each of the plurality of mixing members are stirred and mixed in a dispersed state in the binder to form a stirred mixture together with the binder, The stirred mixture has at least one labyrinth-like path formed between each of the plurality of mixing bodies facing each other among the plurality of mixing elements, Each of the plurality of mixing elements is located within the at least one labyrinth-like path at its mixed glass fiber portion, The stirred mixture is formed into the predetermined layer shape.

12. In addition to the plurality of mixing elements and the binder, a cotton fiber element is provided, The stirred mixture is obtained by stirring and mixing the plurality of mixing members and the cotton fiber member with the binder in a dispersed state, 12. The floor silencer for an automobile according to claim 11, wherein the mixing ratio A / B based on the mass of B relative to the mass of A is set so as to reduce noise having frequencies within a predetermined frequency band, when the plurality of mixed materials are A and the cotton fiber material is B.

13. 13. The floor silencer for an automobile according to claim 12, wherein the predetermined frequency band shifts toward a lower frequency band or a higher frequency band as the mixture ratio A / B increases or decreases.

14. 14. The floor silencer for an automobile according to claim 11, wherein the laminated composite raw material is a laminated composite part that has been installed in an automobile or is to be discarded due to poor quality.

15. Each of the plurality of mixing elements is a first mixing element, The plurality of pulverized raw materials having the linear shape among the plurality of pulverized raw materials are provided as a plurality of second mixing members, the stirred mixture is formed by stirring and mixing the plurality of first mixing members and the plurality of second mixing members in the binder in a dispersed state, The plurality of second mixing elements are located within the at least one labyrinth-like path together with the plurality of mixed glass fiber portions of each of the plurality of first mixing elements. A floor silencer for an automobile as described in any one of claims 11 to 14.

16. the porous layer of the laminated composite base material has a plurality of porous fibers; Each of the plurality of mixing members has a corresponding portion in its mixing body corresponding to the porous layer, each of the plurality of mixing members is formed so that a mixed porous fiber portion made of a plurality of porous fibers extends from the corresponding portion of the mixing body corresponding to the porous layer as the grinding proceeds; The mixed porous fiber portion of each of the plurality of mixing elements is located within the labyrinth-like path together with the glass fiber portion of each of the plurality of mixing elements. A floor silencer for an automobile as described in any one of claims 11 to 15. Irresistible.

17. the porous layer of the laminated composite base material has a plurality of porous fibers; Each of the plurality of mixing members has a corresponding portion in its mixing body corresponding to the porous layer, each of the plurality of mixing members is formed so that a mixed porous fiber portion made of a plurality of porous fibers extends from the corresponding portion of the mixing body corresponding to the porous layer as the grinding proceeds; The floor silencer for an automobile according to claim 15, characterized in that the mixed porous fiber portion of each of the plurality of mixing elements, together with the glass fiber portion of each of the plurality of mixing elements and the plurality of mixing elements, is located within the maze-like path.

18. The mixing body of each of the plurality of mixing elements is configured so that the larger the mixing body, the lower the air permeability so as to reduce noise having frequencies in the low-to-mid frequency band, and the smaller the mixing body, the higher the air permeability so as to reduce noise having frequencies in the high frequency band. A floor silencer for an automobile described in any one of claims 11 to 17.

19. The engine is provided as the prime mover, and Each mixing body of the plurality of mixing elements is set to reduce noise having a frequency in the low to mid frequency range at its size. A floor silencer for an automobile as described in any one of claims 11 to 18.

20. a battery set including a group of batteries arranged along the underside of the floor wall, the battery set using at least one of the electric motor and the engine as the prime mover and supplying power to the electric motor, Each mixing body of the plurality of mixing elements is set to reduce noise having frequencies in the low-medium frequency range and the high frequency range at its size. A floor silencer for an automobile as described in any one of claims 11 to 18.

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