Vibration damping structure

Abstract

To provide a vibration damping structure capable of achieving high vibration damping effects without increasing a rigidity difference between structural members.SOLUTION: A vibration damping structure 1 includes a beam 10 as a long structure, and a damping material 11 joined to the beam 10, the damping material 11 being arranged along the beam 10 in an X direction where the beam 10 extends, the damping material 11 having a body part 111 arranged separating from an upper wall 10a of the beam 10 to the upper side in a Z direction, and a clip 112 joining the body part 111 to the beam 10. In the X direction, the clip 112 of the damping material 11 at its portion joined to the beam 10 is a joint portion 11b, and the damping material 11 at its portion other than the portion is a separation portion 11a. The damping material 11 is formed to show higher damping than the beam 10 and also formed so that the primary resonant frequency of the damping material 11 is equal to or lower than the primary resonant frequency of the beam 10.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a vibration damping structure, and more particularly to a vibration damping structure including an elongated member. [Background technology]

[0002] Long members extending in one direction are often used in vehicle bodies, building structures, etc. In various fields including vehicles and buildings, various techniques for damping vibrations of long members have been studied. For example, Patent Document 1 discloses a structure for damping vibrations of long frame members (front side frames) in a vehicle body.

[0003] Patent Document 1 discloses a vibration damping structure having a cylindrical front side frame and a bulkhead housed in the cylinder of the front side frame. The bulkhead is disposed in the cylinder of the front side frame so as to be perpendicular to the longitudinal direction of the front side frame, and is fixed at its outer periphery to the inner wall surface of the front side frame. The inner wall surface of the front side frame and the bulkhead are fixed to each other at a portion where they are fixed by spot welding and at a portion where they are fixed by a damping member made of a viscoelastic material. Patent Document 1 discloses that by fixing the inner wall surface of the front side frame and the bulkhead in the above manner, it is possible to improve the rigidity of the front side frame while damping vibration. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-49375 A Summary of the Invention [Problem to be solved by the invention]

[0005] There is a demand for further improving the vibration damping effect of long members used in various structures including vehicles and buildings. In response to such demand, it is conceivable to adopt a method of increasing the amount of strain energy stored by increasing the difference in rigidity between the front side frame and the bulkhead, which are framework members, in the configuration disclosed in the above Patent Document 1.

[0006] However, if the difference in rigidity between the front side frame and the bulkhead is increased in order to increase the amount of stored strain energy as described above, it is considered that other performance required of the front side frame will be adversely affected, and therefore it is difficult to adopt the above-mentioned method.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a vibration damping structure that can obtain a high vibration damping effect without increasing the rigidity difference between the components included in the structure. [Means for solving the problem]

[0008] A vibration damping structure according to one aspect of the present invention includes a long first member that is a structural body, and a second member that is arranged along the first member and joined to the first member. The second member has a plurality of joints and one or more non-joints. The plurality of joints are joined to the first member with a gap between them in a first direction in which the first member extends. The one or more non-joints are not joined to the first member that is arranged adjacent to the joints in the first direction. In the vibration damping structure according to this aspect, the second member is formed to have a higher damping than the first member, and is formed so that the first-order resonant frequency of the second member is equal to or lower than the resonant frequency of the first member. The non-jointed portions of the second member have proximate portions that are respectively proximate to the first member in a direction perpendicular to the first direction, and non-proximate portions that are arranged adjacent to the proximate portions in the first direction and are farther away from the first member in the perpendicular direction than the proximate portions.

[0009] In the vibration damping structure according to the above aspect, the second member attached to the first member has a joint and a non-joint. The second member is formed to have higher damping (a larger loss factor) than the first member. Furthermore, the second member is set so that its first-order resonance frequency is equal to or lower than the resonance frequency of the first member. In the vibration damping structure according to the above aspect, the first member has an out-of-plane deformation mode in the first direction, so that vibration is input from the first member to the second member through the joints arranged at intervals in the first direction, and the non-joints in the second member resonate without being restrained by the first member. Therefore, in the vibration damping structure according to the above aspect, strain energy can be stored in the joints of the second member. In the vibration damping structure according to the above embodiment, the non-joint portion of the second member has a proximal portion and a non-proximal portion. As a result, in the vibration damping structure according to the above embodiment, the non-proximal portion of the second member resonates without being constrained by the first member due to the vibration input from the first member through the joint. Therefore, the vibration damping structure according to the above embodiment is even more advantageous in storing strain energy in the joint of the second member.

[0010] Therefore, in the vibration damping structure of the above embodiment, a high vibration damping effect can be obtained without increasing the rigidity difference between the first member, which is a long-sized structure, and the second member joined to the first member.

[0011] In the vibration damping structure according to the above aspect, when the second member is viewed in a plan view from the orthogonal direction, the adjacent portion may have a lattice shape. In the vibration damping structure according to the above aspect, the adjacent portion has a lattice shape in a plan view from the orthogonal direction. Therefore, in the vibration damping structure according to the above aspect, the vibration damping structure has a plurality of resonance planes in a two-dimensional direction intersecting with the joining direction of the first member and the second member. Therefore, in the vibration damping structure according to the above aspect, it is easy to set the first-order resonance frequency of the second member to be equal to or lower than the first-order resonance frequency of the first member.

[0012] In the vibration damping structure according to the above aspect, the proximal portion of the second member may be provided in a columnar shape standing from the non-proximal portion towards the first member in the orthogonal direction. In the vibration damping structure according to the above aspect, the adjacent portion in the non-jointed portion of the second member is configured to stand in a columnar shape, which makes it easy to adjust the resonance frequency of the second member by adjusting the thickness (cross-sectional area) of the column or the distance between the columns.

[0013] In the vibration damping structure according to the above aspect, the joint of the second member may be arranged at an antinode position of at least one of a first and a second resonance in the first member. In the vibration damping structure according to the above aspect, the joint of the second member is disposed at an antinode position (a position where the amplitude is maximum) of at least one of the first and second resonances in the first member, so that the vibration damping structure according to the above aspect transmits vibration from the first member to the second member with high efficiency.

[0014] In the vibration damping structure according to the above aspect, the second member may be formed using a porous material. In the vibration damping structure according to the above aspect, the second member is formed using a porous material, which makes it possible to effectively damp vibrations while reducing the weight compared to a case in which the second member is formed using a solid material.

[0015] A vibration damping structure according to another aspect of the present invention includes a first member having an elongated shape, which is a structural body, and a second member arranged along the first member and joined to the first member. The second member has a plurality of joints and one or more non-joints. The plurality of joints are joined to the first member with a space between them in a first direction in which the first member extends. The one or more non-joints are not joined to the first member arranged adjacent to the joints in the first direction. In the vibration damping structure according to this aspect, the second member is formed to have a higher damping than the first member, and is formed so that the first-order resonant frequency of the second member is equal to or lower than the resonant frequency of the first member. The joints of the second member are arranged at antinode positions of at least one of the first-order and second-order resonances of the first member.

[0016] In the vibration damping structure according to the above aspect, the second member attached to the first member has a joint and a non-joint. The second member is formed to have higher damping (a larger loss factor) than the first member. Furthermore, the second member is set so that its first-order resonance frequency is equal to or lower than the resonance frequency of the first member. In the vibration damping structure according to the above aspect, the first member has an out-of-plane deformation mode in the first direction, so that vibration is input from the first member to the second member through the joints arranged at intervals in the first direction, and the non-joints in the second member resonate without being restrained by the first member. Therefore, in the vibration damping structure according to the above aspect, strain energy can be stored in the joints of the second member. In the vibration damping structure according to the above aspect, the joint of the second member is disposed at an antinode position (a position where the amplitude is maximum) of at least one of the first and second resonances in the first member, so that the vibration damping structure according to the above aspect transmits vibration from the first member to the second member with high efficiency.

[0017] A vibration damping structure according to another aspect of the present invention includes a long first member that is a structural body, and a second member that is arranged along the first member and joined to the first member. The second member has a plurality of joints and one or more non-joints. The plurality of joints are joined to the first member with a gap between them in a first direction in which the first member extends. The one or more non-joints are not joined to the first member that is arranged adjacent to the joints in the first direction. In the vibration damping structure according to this aspect, the second member is formed to have a higher damping than the first member, and is formed so that the first-order resonant frequency of the second member is equal to or lower than the resonant frequency of the first member. The second member is formed using a porous material.

[0018] In the vibration damping structure according to the above aspect, the second member attached to the first member has a joint and a non-joint. The second member is formed to have higher damping (a larger loss factor) than the first member. Furthermore, the second member is set so that its first-order resonance frequency is equal to or lower than the resonance frequency of the first member. In the vibration damping structure according to the above aspect, the first member has an out-of-plane deformation mode in the first direction, so that vibration is input from the first member to the second member through the joints arranged at intervals in the first direction, and the non-joints in the second member resonate without being restrained by the first member. Therefore, in the vibration damping structure according to the above aspect, strain energy can be stored in the joints of the second member. In the vibration damping structure according to the above aspect, the second member is formed using a porous material, which makes it possible to effectively damp vibration while reducing the weight compared to a case in which the second member is formed using a solid material.

[0019] In the vibration damping structure according to the above aspect, the first member may be a pillar of a vehicle body, and the second member may be a pillar trim attached to an inner side of the vehicle compartment relative to the pillar. In the vibration damping structure according to the above aspect, the pillar of the vehicle body is used as the first member, and the pillar trim is used as the second member, which makes it possible to effectively damp vibrations of the pillar in the vehicle body.

[0020] A vibration damping structure according to another aspect of the present invention includes a first member having an elongated shape, which is a structural body, and a second member arranged along the first member and joined to the first member. The second member has a plurality of joints and one or more non-joints. The plurality of joints are joined to the first member with a space between them in a first direction in which the first member extends. The one or more non-joints are not joined to the first member arranged adjacent to the joints in the first direction. In the vibration damping structure according to this aspect, the second member is formed to have a higher damping than the first member, and is formed so that a first-order resonant frequency of the second member is equal to or lower than a resonant frequency of the first member. The first member is a pillar of a vehicle body, and the second member is a pillar trim attached to the interior side of the pillar.

[0021] In the vibration damping structure according to the above aspect, the second member attached to the first member has a joint and a non-joint. The second member is formed to have higher damping (a larger loss factor) than the first member. Furthermore, the second member is set so that its first-order resonance frequency is equal to or lower than the resonance frequency of the first member. In the vibration damping structure according to the above aspect, the first member has an out-of-plane deformation mode in the first direction, so that vibration is input from the first member to the second member through the joints arranged at intervals in the first direction, and the non-joints in the second member resonate without being restrained by the first member. Therefore, in the vibration damping structure according to the above aspect, strain energy can be stored in the joints of the second member. In the vibration damping structure according to the above aspect, the pillar of the vehicle body is used as the first member, and the pillar trim is used as the second member, which makes it possible to effectively damp vibrations of the pillar in the vehicle body.

[0022] In the vibration damping structure relating to the above-mentioned aspect, the non-jointed portion of the second member may be formed so as to face the first member at a distance in a direction perpendicular to the first direction. In the vibration damping structure according to the above aspect, the non-jointed portion of the second member is spaced apart from the first member, so that when vibration is input from the first member, resonance at the non-jointed portion is less likely to be restricted by the first member.

[0023] In the vibration damping structure of the above-mentioned aspect, the second member has a main body portion arranged at a distance from the first member in the perpendicular direction, and a mechanical fastening portion that mechanically fastens the main body portion and the first member, and the joint portion is a portion joined to the first member by the mechanical fastening portion, and the non-joint portion is a portion of the main body portion excluding the portion joined to the first member by the mechanical fastening portion. In the vibration damping structure according to the above aspect, the joint of the second member is a mechanical fastening portion. Therefore, in the vibration damping structure according to the above aspect, the first member and the second member can be reliably joined by mechanical fastening. Also, in the vibration damping structure according to the above aspect, the second member is entirely unjoined except for the portion of the main body that is joined to the first member by the mechanical fastening portion. Therefore, in the vibration damping structure according to the above aspect, it is easily possible to make the first-order resonant frequency of the second member equal to or lower than the first-order resonant frequency of the first member.

[0024] In the vibration damping structure according to the above aspect, the plurality of joints may be arranged linearly along the first direction. In the vibration damping structure according to the above aspect, the multiple joints are arranged linearly along the first direction, so that the amplitude direction of the vibration input from the first member to the second member through each of the multiple joints is the same in the vibration damping structure according to the above aspect. Therefore, in the vibration damping structure according to the above aspect, the resonance mode when the non-jointed portion of the second member resonates is not easily inhibited.

[0025] In the vibration damping structure according to the above aspect, the first member may have a closed cross section in a direction perpendicular to the first direction. In the vibration damping structure according to the above aspect, the first member has a closed cross-sectional structure, which makes it possible to control the torsional rigidity of the first member when a bending load is applied while suppressing an increase in mass, and therefore makes it possible for the first member itself to achieve a high vibration damping effect.

[0029] In the vibration damping structure according to the above aspect, a first-order resonance frequency of the second member may be set to be equal to or lower than a first-order or second-order resonance frequency of the first member.

[0030] In the vibration damping structure according to the above aspect, the first resonance frequency of the second member is set to be equal to or lower than the first or second resonance frequency of the first member. When the first resonance frequency of the second member is set to be equal to or lower than the first or second resonance frequency of the first member in this manner, it is effective in obtaining a high vibration damping effect without increasing the rigidity difference between the first member, which is a long-sized structure, and the second member joined to the first member.

[0031] In the vibration damping structure according to the above aspect, a first resonance frequency of the second member may be set to be substantially the same as a first or second resonance frequency of the first member.

[0032] In the vibration damping structure according to the above aspect, the first resonance frequency of the second member is set to be substantially the same as the first or second resonance frequency of the first member. When the first resonance frequency of the second member is set to be substantially the same as the first or second resonance frequency of the first member in this manner, it is particularly effective in obtaining a high vibration damping effect.

[0033] Here, "substantially the same" in the above means not only the case where the first resonance frequency of the second member coincides with the first or second resonance frequency of the first member, but also includes the frequency range corresponding to the base of each peak of the first or second resonance frequency of the first member. Specifically, when the resonance frequency of the first member is Fr and the base region is α, the range from (Fr-α) to (Fr+α) can be defined as "substantially the same". Note that the above "α" can be defined as (Fr×√2), for example.

[0034] In the vibration damping structure according to the above aspect, a first-order resonant frequency of the second member may be set to be substantially the same as a first-order resonant frequency of the first member.

[0035] In the vibration damping structure according to the above aspect, the first resonance frequency of the second member is set to be substantially the same as the first resonance frequency of the first member. When the first resonance frequency of the second member is set to be substantially the same as the first resonance frequency of the first member in this manner, a more significant vibration damping effect can be obtained.

[0036] In the vibration damping structure according to the above aspect, the first member may be formed using a metal material, and the second member may have a loss factor of 0.01 or more.

[0037] In the vibration damping structure according to the above aspect, the first member is made of a metal material, and the loss factor of the second member is set to be equal to or greater than 0.01, which provides a significant effect in terms of vibration damping compared to a case in which the vibration damping structure is not adopted. Effect of the Invention

[0040] In the vibration damping structure according to each of the above aspects, a high vibration damping effect can be obtained without increasing the difference in rigidity between the members included in the structure. [Brief description of the drawings]

[0041] [Figure 1] 1A and 1B are a perspective view and a cross-sectional view showing a vibration damping structure according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing a part of the cross section taken along line II-II in FIG. [Diagram 3] 1A and 1B are a perspective view and a cross-sectional view showing the configuration of a base model used in the analysis. [Figure 4] FIG. 2A is a cross-sectional view showing the configuration of an analytical model according to a comparative example, and FIG. 2B is a cross-sectional view showing the configuration of an analytical model according to the first embodiment. [Diagram 5] FIG. 13 is a perspective view for explaining an analysis method. [Figure 6] Graph (a) is a graph showing the inertance for each frequency in the models according to the comparative example and the examples 1 and 1-2, and graph (b) is a graph showing the vibration transmission characteristics at 0 to 450 Hz in the models according to the comparative example and the examples 1 and 1-2. [Figure 7] 1 is a graph showing the distribution of loss energy in a base model, a model according to a comparative example, and a model according to a first embodiment. [Figure 8] 4A and 4B are schematic diagrams showing the first and second resonance modes of a beam in a vibration damping structure. [Figure 9] 4 is a graph showing the relationship between the loss factor in the main body of the damping material and the amount of reduction in the primary resonance peak. [Figure 10]5A and 5B are a perspective view and a cross-sectional view showing a vibration damping structure according to a second embodiment of the present invention. [Figure 11] 10 is a graph showing the inertance for each frequency in the vibration damping structure according to the second embodiment. [Figure 12] 1 is a graph showing the distribution of loss energy in each of a base model, a model according to a comparative example, a model according to an embodiment 1, and a model according to an embodiment 2. [Figure 13] FIG. 13(a) is an exploded sectional view showing a vibration damping structure according to a third embodiment of the present invention, and FIG. 13(b) is a perspective view showing the configuration of a damping material. [Figure 14] 13(a) is a graph showing ERP for each frequency in each model according to Examples 3 to 5, and (b) is a graph showing ERP peak values ​​in each model according to Examples 3 to 5. [Figure 15] FIG. 2 is a perspective view showing a part of the configuration of the vehicle body. [Figure 16] FIG. 2 is a cross-sectional view showing a configuration of a front pillar in a vehicle body. [Figure 17] FIG. 2 is a cross-sectional view showing a configuration of a center pillar in a vehicle body. [Figure 18] 4 is a cross-sectional view showing a configuration of a damping material in a vibration damping structure according to Modification 1. FIG. [Figure 19] 11 is a developed cross-sectional view showing the configuration of a damping material in a vibration damping structure according to Modification 2. FIG. [Figure 20] 13 is a perspective view showing a configuration of a damping material in a vibration damping structure according to Modification 3. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example of the present invention, and the present invention is not limited to the embodiment described below except for the essential configuration.

[0043] [First embodiment] 1. Vibration damping structure 1 A vibration damping structure 1 according to a first embodiment of the present invention will be described with reference to Figures 1 and 2. Note that Figures 1 and 2 show the vibration damping structure 1 in a schematic manner, and various modifications are possible depending on the position to which it is applied, etc.

[0044] 1 and 2, the vibration damping structure 1 according to this embodiment is a structural body including a beam (first member) 10 that is long in the X direction, a damping material (second member) 11 joined to the beam 10, and covers 12 and 13 that close both ends in the X direction of the beam 10. The beam 10 is made of a material containing a metal material (e.g., Fe), and has a closed cross-sectional structure in a direction perpendicular to the X direction as shown in the enlarged portion of FIG.

[0045] The damping material 11 has a main body 111 having a U-shaped cross section, and a plurality of clips 112 for joining the main body 111 to the beam 10. The main body 111 is disposed spaced outward from the upper wall 10a and the side walls 10b, 10c of the beam 10. Note that there is no joint or the like between the lower edge 111a of the main body 111 in the Z direction and the side walls 10b, 10c of the beam 10, and a gap G is provided between them.

[0046] The clip 112 is formed, for example, using a resin material, and is inserted through a through hole opened in the upper wall 10a of the beam 10. In the vibration damping structure 1, the main body 111 and the beam 10 are joined by the clips 112 at four points in the longitudinal direction (X direction) of the beam 10. That is, the beam 10 and the damping material 11 are joined by a plurality of mechanical fastening parts. As shown in FIG. 1, in this embodiment, the four joining points (points where the clips 112 are arranged) are arranged at approximately equal intervals. Specifically, two joining points are arranged at both ends of the beam 10 in the X direction, and the remaining two joining points are arranged at each boundary when the length of the beam 10 in the X direction is divided into approximately three equal parts.

[0047] 2, in the vibration damping structure 1, the points where the main body 111 and the beam 10 are joined by the clips 112 are arranged to be spaced apart from each other in the X direction. Between the joint points in the X direction by the clips 112, the main body 111 and the beam 10 are spaced apart from each other. In the damping material 11, the part spaced apart from the beam 10 is referred to as a spaced part 11a, and the part joined to the beam 10 by the clips 112 is referred to as a joint part 11b.

[0048] In the vibration damping structure 1 of this embodiment, the damping material 11 is formed so as to have higher damping (a larger loss coefficient) than the beam 10, and is also formed so that the first-order resonant frequency of the damping material 11 is the same as or lower than the first-order resonant frequency of the beam 10.

[0049] 2. Vibration damping In order to increase the vibration damping of a certain component, it is necessary to increase (i) the strain energy distribution rate, which indicates the proportion of the component's strain energy in the whole, and (ii) the loss factor of the component. The damping rate is expressed by the following formula.

[0050]

number

[0051] In the above relation, η m is the loss coefficient of component m, Ue m is element e m where Utotal refers to the total strain energy.

[0052] 3.Analysis using analytical model The configurations of models 5 to 7 used to confirm the vibration damping effect will be described with reference to FIG. 3 and FIG.

[0053] (1) Analysis model (base model) 5 As shown in Fig. 3, the model (base model) 5 used as the basis for this analysis is composed of a beam 10 with a length L0 and covers 12 and 13 that close both ends in the X direction of the beam 10. As shown in the enlarged portion of Fig. 3, the width of the beam 10 is W0, the height is H0, the thickness is T0, and the radius of curvature of the four inner corners is R.

[0054] In the base model 5, Fe was used as the constituent material of the beam 10 and the lids 12 and 13. The lids 12 and 13 were joined to the end openings of the beam 10 by full-circumference welding.

[0055] (2) Analytical Model 6 for Comparative Example As shown in Fig. 4(a), the analytical model 6 according to the comparative example differs from the base model 5 having the above configuration in that it includes a damping material 61. The damping material 61 has a main body 111 and a clip 112, similar to the damping material 11 of the vibration damping structure 1 according to the first embodiment. In the model 6 according to the comparative example, the damping material 61 further includes a joining member 613. The joining member 613 is an adhesive layer made of rubber, and joins the edge portion 111a of the main body 111 to the outer surfaces of the side walls 10b, 10c of the beam 10 (the portion indicated by the arrow A1).

[0056] Although not shown in Fig. 4(a), the damping material 61 and the beam 10 are joined by two clips 112. Specifically, of the clips 112 shown in Fig. 1, the two clips 112 arranged at both ends of the beam 10 in the longitudinal direction (X direction) are omitted in the model 6 according to the modified example.

[0057] The main body 111 of the damping material 61 included in the model 6 is a member made of polypropylene (PP).

[0058] (3) Analytical Model 7 according to Example 1 4(b), the analytical model 7 according to Example 1 differs from the model 6 according to the comparative example in that the damping material 11 does not have a joining member 61. That is, in model 7 according to Example 1, like the damping material 11 of the vibration damping structure 1 according to the first embodiment, the end edge portion 111a of the main body portion 111 is not joined to the outer surfaces of the side walls 10b, 10c of the beam 10, and is arranged with a gap G (the portion indicated by the arrow A2).

[0059] In the model 7 according to the first embodiment, the damping material 11 and the beam 10 are joined together by four clips 112. The joints formed by the four clips 112 are the same as the joints (the positions where the clips 112 are arranged) shown in FIG.

[0060] In the model 7 according to the first embodiment, the damping material 11 is made of a resin material having a lower Young's modulus than the beam 10.

[0061] (4) Example 1-2 The analytical model 8 according to Example 1-2 had the same structure as the model 6 according to the comparative example, except that the Young's modulus of the bonding member 613 was different. The bonding member 613 of model 8 was formed using a material having a lower Young's modulus than the bonding member 613 of model 6 according to the comparative example. In model 8, the Young's modulus of the bonding member 613 was set low, so that the first-order resonant frequency of the damping material 61 was made substantially the same as the resonant frequency (first-order or second-order resonant frequency) of the beam 10.

[0062] (5) Analysis method The analysis method using the above-mentioned models 6 to 8 will be described with reference to FIG.

[0063] As shown in Fig. 5, for each of models 6 to 8 according to the comparative example and examples 1 and 1-2, a constant load vibration was applied to the lid 12 in the Z direction. Then, the response in the Z direction outputted from the other lid 13 was detected.

[0064] In addition, in the model 7 according to the embodiment 1, the analysis was performed under a relationship in which the ratio of the loss factor of the beam 10 to the damping material 11 was 3%.

[0065] (6) Analysis results The analysis was performed using the above method, and the results obtained will be described with reference to Figures 6 and 7. Figure 6(a) shows the inertance for each frequency in models 6 to 8 according to the comparative example and examples 1 and 1-2, and Figure 6(b) shows the vibration transmission characteristics at 0 to 450 Hz in the models according to the comparative example and examples 1 and 1-2. Note that inertance is the ratio between the input force and the output acceleration.

[0066] 6(a), the base model 5 has a peak near 300 Hz. The peak near 300 Hz is a peak in the two-node bending of the base model 5.

[0067] On the other hand, in the model 6 according to the comparative example, there are peaks near 280 Hz and near 630 Hz. The peak near 280 Hz is a peak due to two-node bending of the beam 10, and the peak near 630 Hz is a peak due to resonance of the damping material 61. In the model 6 according to the comparative example, the main body 111 of the damping material 61 is joined to the side walls 10b and 10c of the beam 10 by the joining member 613, so that the resonance frequency (630 Hz) of the damping material 61 exists in a frequency band higher than the first resonance frequency (near 300 Hz) of the beam 10. Therefore, in the model 6 according to the comparative example, the peak height near 280 Hz is hardly lower than the peak height near 300 Hz in the base model 5.

[0068] Model 7 according to Example 1 also has a peak near 300 Hz, but the height of the peak near 300 Hz in model 7 is significantly lower than that in base model 5. This is considered to be because, in model 7 according to Example 1, the resonant frequency of damping material 11 is in a frequency band lower than the first-order resonant frequency (near 300 Hz) of beam 10.

[0069] In model 8 according to Example 1-2, the peak of beam 10 near 300 Hz is significantly reduced, and there are low-value peaks at frequencies around that frequency. This suggests that model 8 according to Example 1-2 can reduce vibration energy the most.

[0070] As shown in FIG. 6(b), the vibration transmission characteristic of the model 6 according to the comparative example was about 59 dB. In contrast, the vibration transmission characteristic of the model 7 according to the example 1 was about 53 dB, and the vibration transmission characteristic of the model according to the example 1-2 was about 47 dB. The vibration transmission characteristic of the model 7 according to the example 1 was lower than that of the model 6 according to the comparative example, and the vibration transmission characteristic of the model 8 according to the example 1-2 was lower than that of the model 7 according to the example 1. From these, it can be seen that the model 7 according to the example 1 in which the first-order resonant frequency of the damping material 11 is equal to or lower than the resonant frequency of the beam 10 is superior to the model 6 according to the comparative example in terms of vibration damping effect, and the model 8 according to the example 1-2 in which the first-order resonant frequency of the damping material 11 is approximately the same as the resonant frequency of the beam 10 can obtain a particularly remarkable vibration damping effect.

[0071] Next, the sharing of loss energy in each of Models 5 to 7 will be described with reference to Fig. 7. Fig. 7 is a graph showing the sharing of loss energy in the frequency range of 0 to 500 Hz for each of Models 5 to 7.

[0072] 7, in model 6 according to the comparative example, the energy sharing rate of beam 10 is 57 to 58%. In contrast, in model 7 according to the example 1, the energy sharing rate of beam 10 is about 10%, which is significantly reduced compared to the comparative example.

[0073] It is believed that the above results are achieved by the vibration energy of the beam 10 being transmitted to the damping material 11 joined to the beam 10 and being absorbed by the damping material 11. It is also presumed that in model 7 according to Example 1, the energy distribution rate of the beam 10 is reduced, and thus the transmission characteristics of the bending mode in which the energy of the beam 10 is dominant is significantly improved.

[0074] Although FIG. 7 does not show the energy sharing rate in model 8 according to example 1-2, the inventors have confirmed that a phenomenon similar to that in model 7 according to example 1 occurs.

[0075] 4. Joint between beam 10 and damping material 11 As described above, in the vibration damping structure 1 according to this embodiment, the beam 10 and the damping material 11 are joined at four locations. A method for setting the joining locations will be described with reference to FIG.

[0076] 8, in the first-order resonance of the beam 10, the antinode position (the position where the amplitude is maximum) of the resonance exists in the center part in the longitudinal direction. In contrast, in the second-order resonance of the beam 10, the antinode portion of the resonance exists at each boundary part (arrow B) when the beam 10 is divided into three parts in the longitudinal direction.

[0077] In this embodiment, the joints are set at the antinodes in the second resonance, as indicated by arrow B in Fig. 8. However, if the objective is to reduce the first resonance in a structure to which the vibration damping structure 1 is actually applied, it is desirable to set the joints at the antinodes in the first resonance of the beam 10. It is also possible to set the joints at both the antinodes in the first resonance and the antinodes in the second resonance of the beam 10.

[0078] 1, in the vibration damping structure 1 according to this embodiment, the four joints are arranged in a line (straight line) in plan view from the Z direction. However, it is also possible to arrange a plurality of joints in a curved line depending on the shape of the framework member (first member).

[0079] 5. Consideration of the loss factor of the main body 111 of the damping material 11 In order to obtain a high vibration damping effect, a study was conducted on a desirable loss factor of the main body 111 in the damping material 11. The results of the study are shown in FIG.

[0080] In this study, the above-mentioned base model 5 and model 7 according to the embodiment 1 were used.

[0081] 9, in model 7 including the damping material 11, the reduction in the primary resonance peak gradually decreases as the loss factor approaches "0.001" to "0.1". Then, conversely, it gradually increases from the point where the loss factor is slightly larger than "0.1".

[0082] In model 7 equipped with damping material 11, the point where the reduction in the first-order resonance peak is smallest is designated as P1. A perpendicular line passing through P1 is drawn on the graph. In this case, the intersection point with the characteristic line of model 5 having no damping material is designated as P2. Then, a line passing through the midpoint P3 between P1 and P2 and parallel to the horizontal axis is drawn on the graph. In this case, the intersection point with the characteristic line of model 7 equipped with damping material 11 is designated as P4.

[0083] The loss factor in P4 is "0.01". Therefore, when the beam 10 is made of a metal material (for example, Fe), by setting the loss factor of the main body (PP: polypropylene) 111 of the damping material 11 to "0.01", it is possible to secure 50% or more of the maximum effect compared to model 5 having no damping material.

[0084] 6.Effects In the vibration damping structure 1 according to this embodiment, the damping material (second member) 11 attached to the beam (first member) 10 has a joint portion 11b and a non-joint portion 11a. The damping material 11 is formed so as to have a higher damping (a larger loss factor) than the beam 10. Furthermore, the damping material 11 is set so that its first resonance frequency is equal to or lower than the resonance frequency of the beam 10 (equal to or lower than the first or second resonance frequency of the beam 10). In the vibration damping structure 1, the beam 10 has an out-of-plane deformation mode in the X direction, so that vibration is input from the beam 10 to the damping material 11 through the joint portions 11b arranged at intervals in the X direction, and the non-joint portions 11a of the damping material 11 resonate without being restrained by the beam 10. Therefore, in the vibration damping structure 1, strain energy can be stored in the joint portions 11b of the damping material 11.

[0085] In the vibration damping structure 1, when the multiple (four) joints 11b in the damping material 11 are viewed in a plan view from the Z direction, the multiple joints 11b are arranged so as to be aligned linearly along the X direction. Therefore, in the vibration damping structure 1, the amplitude direction of the vibration input from the beam 10 to the damping material 11 via each of the multiple joints 11b is the same over the entire area. Therefore, in the vibration damping structure 1, the resonance mode when the non-jointed parts 11a in the damping material 11 resonate is less likely to be inhibited.

[0086] In the vibration damping structure 1, the beam 10 has a closed cross-sectional structure in a direction perpendicular to the X direction. Therefore, in the beam 10, it is possible to control the torsional rigidity when a bending load is input while suppressing an increase in mass, and the beam 10 itself can obtain a high vibration damping effect.

[0087] In the vibration damping structure 1, the non-jointed portion 11a of the damping material 11 is spaced apart from the beam 10. Therefore, when vibration is input from the beam 10, resonance at the non-jointed portion 11a is less likely to be restricted by the beam 10.

[0088] In the vibration damping structure 1, the joint 11b of the damping material 11 is formed by the clip 112 which is a mechanical fastening part. Therefore, in the vibration damping structure 1, the beam 10 and the main body 111 of the damping material 11 can be reliably joined by mechanical fastening. Also, in the vibration damping structure 1, the entire part of the damping material 11 except for the part of the main body 111 joined to the beam 10 by the clip 112 is the non-jointed part 11a. Therefore, in the vibration damping structure 1, it is easily possible to make the first-order resonant frequency of the damping material 11 equal to or lower than the first-order resonant frequency of the beam 10.

[0089] In the vibration damping structure 1, the joint 11b of the damping material 11 is disposed at the antinode position (the position where the amplitude is maximum) of the secondary resonance in the beam 10. Therefore, in the vibration damping structure 1, the vibration is transmitted from the beam 10 to the damping material 11 with high efficiency.

[0090] In the vibration damping structure 1, when the beam 10 is made of a metal material, the loss coefficient of the damping material 11 is set to 0.01 or more. This makes it possible to obtain a significant effect in terms of vibration damping, compared to a case in which the vibration damping structure 1 is not adopted.

[0091] As described above, in the vibration damping structure 1 according to this embodiment, a high vibration damping effect can be obtained without increasing the difference in rigidity between members included in the structure.

[0092] [Second embodiment] 1. Vibration damping structure 2 A vibration damping structure 2 according to a second embodiment of the present invention will be described with reference to Fig. 10. In Fig. 10, the same components as those in the vibration damping structure 1 according to the first embodiment are denoted by the same reference numerals.

[0093] 10, the vibration damping structure 2 according to this embodiment includes a beam (first member) 10 which is a structural body and is long in the X direction, a damping material (second member) 21 joined to the beam 10, and covers 12 and 13 which close both ends in the X direction of the beam 10. The beam 10 is made of a metal material (e.g., Fe) as in the first embodiment, and has a closed cross-sectional structure in a direction perpendicular to the X direction.

[0094] The damping material 21 has a main body 111 having a U-shaped cross section, a plurality of clips 112 for joining the main body 111 to the beam 10, and a foamed portion 213 provided inside the main body 111. The main body 111 is disposed spaced outward from the upper wall 10a and the side walls 10b, 10c of the beam 10. The foamed portion 213 is also disposed spaced outward from the upper wall 10a and the side walls 10b, 10c of the beam 10, as shown in the enlarged portion. The lower edge portion 213a of the foamed portion 213 in the Z direction is also disposed with a gap G between it and the side walls 10b, 10c of the beam 10 without any joint or the like interposed therebetween.

[0095] Here, in the vibration damping structure 2 according to this embodiment, the main body 111 of the damping material 21 is formed using a material with higher damping properties than the main body 111 of the damping material 11 according to the first embodiment. Also, the foam portion 213 is formed from a porous material (for example, an acrylic foam material).

[0096] The foam portion 213 is formed using a material having a Young's modulus of about 15% and a loss factor of about 130% relative to the damping material 21 .

[0097] In the vibration damping structure 2 of this embodiment, the main body 111 of the damping material 21 is formed using a high-damping material having a higher loss coefficient than the main body 111 of the damping material 11 used in the first embodiment described above, and the foam portion 213 is formed using a foam material whose Young's modulus is very small compared to that of the high-damping material constituting the main body 111.

[0098] The clip 112 is formed using, for example, a resin material, as in the first embodiment, and is inserted through a through hole opened in the upper wall 10a of the beam 10. In the vibration damping structure 2, the main body 111 and the beam 10 are joined by the clips 112 at four points in the longitudinal direction (X direction) of the beam 10. That is, the beam 10 and the damping material 21 are joined by a plurality of mechanical fastening parts. Moreover, the four joining points (points where the clips 112 are arranged) are arranged at approximately equal intervals, as in the first embodiment.

[0099] Although detailed illustration is omitted, in the vibration damping structure 2, the points where the main body 111 and the beam 10 are joined by the clips 112 are arranged to be spaced apart from each other in the X direction. And, between the joining points in the X direction by the clips 112, the foamed portion 213 and the beam 10 are spaced apart from each other. In the damping material 21 as well, the part spaced apart from the beam 10 is the separated part, and the part joined to the beam 10 by the clips 112 is the joined part.

[0100] In the vibration damping structure 2, the damping material 21 is formed to have higher damping (a larger loss coefficient) than the beam 10, and is also formed so that the first-order resonant frequency of the damping material 21 is the same as or lower than the first-order resonant frequency of the beam 10.

[0101] 2.Analysis using analytical model In addition to the above models 5 to 7, the vibration damping structure 2 according to this embodiment was modeled and analyzed to confirm the vibration damping effect. The results will be described with reference to Figs. 11 and 12.

[0102] Note that the model of the vibration damping structure 2 according to this embodiment (model according to Example 2) differs from the above-mentioned model 7 only in that the damping material 21 includes the foam portion 213, and therefore a detailed description of the model will be omitted.

[0103] 11, the model according to Example 2 also has a peak near 300 Hz, but the height of the peak near 300 Hz in the model according to Example 2 is even lower than that of model 7 according to Example 1. This is considered to be because the model according to Example 2 employs damping material 21 having foamed portion 213, so that vibration energy input from beam 10 is more effectively absorbed by damping material 21.

[0104] Although detailed explanation will be omitted, it has been confirmed that the highest vibration damping effect can be obtained by making the first resonance frequency of the damping material 21 the same as the first resonance frequency of the beam 10.

[0105] Next, the sharing of loss energy in each of the above models 5 to 7 as well as the model according to Example 2 will be described with reference to Fig. 12. Note that Fig. 12 is also a graph showing the sharing of loss energy in the frequency range of 0 to 500 Hz for each model.

[0106] 12, in the model according to Example 2, the energy sharing rate of the beam 10 is significantly reduced to 1 to 2%. This result is considered to be due to the fact that, in addition to the configuration of the model 7 according to Example 1, the damping material 21 is provided with the foamed portion 213, so that the vibration energy transmitted from the beam 10 is more effectively absorbed by the damping material 21.

[0107] [Third embodiment] A vibration damping structure 3 according to a third embodiment of the present invention will be described with reference to Figures 13 and 14. Note that the vibration damping structure 3 according to this embodiment differs from the first and second embodiments in the structure of the damping material 31, but the other configurations are the same. Therefore, the structure of the damping material 31 will be mainly described below.

[0108] As shown in Fig. 13(a), the vibration damping structure 3 includes a beam 10 and a damping material 31. The damping material 31 is joined to the outer surface of the outer wall, including the upper wall 10a, of the beam 10 by a mechanical fastening part (e.g., a clip) not shown. The remaining part of the damping material 31 is arranged spaced apart from the beam 10 and not joined to the beam 10. In other words, the damping material 31 in the vibration damping structure 3 according to this embodiment also has a joint part and a spaced part, similar to the first and second embodiments.

[0109] 13(a) and (b), the separated portion in the damping material 31 has a nearby portion 31b that is close to the beam 10, and a non-close portion 31a that is separated from the beam 10 to the outside of the nearby portion 31b. The non-close portion 31a of the damping material 31 is a recess that is recessed in a direction away from the beam 10. The nearby portion 31b is formed in a rib shape so as to separate the adjacent non-close portions 31a, and is formed in a lattice shape as a whole in a plan view.

[0110] In the vibration damping structure 3 according to this embodiment, the damping material 31 is made of a porous material (for example, an acrylic foam material), and the proximal portion 31b and the non-proximal portion 31a are integrally formed.

[0111] 13(b), the dimensions of the non-proximal portion 31a of the damping material 31 are designated as Lr1, Lr2, and Dr. Preferred values ​​of the dimensions Lr1, Lr2, and Dr were examined using Examples 3 to 5.

[0112] Here, Lr1=Lr2, and in each of Examples 3 to 5, (Example 3)>(Example 4)>(Example 5). In addition, with regard to Dr, (Example 3)=(Example 4)=(Example 5).

[0113] The beam 10 was made of iron (Fe). The damping material 31 was made of an acrylic foam material and had the structure shown in Fig. 13(b). The damping material 31 was made of a resin material or the like having a lower Young's modulus than the beam 10.

[0114] Using each model of Examples 3 to 5 having the above-mentioned structure, vibration was input from the end of the region of the beam 10 where the damping material 31 was joined, and the equivalent radiated power (ERP) for each frequency was used as an index for evaluation. The analysis was performed under a relationship in which the ratio of the loss factor of the beam 10 to the damping material 31 was 0.1%.

[0115] As shown in Fig. 14(a), in the model of Example 3, peaks appeared around 50 Hz and around 60 Hz in the ERP of the beam 10. In the model of Example 4, low peaks appeared around 45 Hz and around 60 Hz in the ERP of the beam 10. In addition, in the model of Example 5, slightly high peaks appeared around 45 Hz and around 55 Hz in the ERP of the beam 10.

[0116] As shown in FIG. 14(b), when the ERP peak value in the model of Example 3 is set to "100", the ERP peak value in the model of Example 4 was "63" and the ERP peak value in the model of Example 5 was "186".

[0117] From the above results, it was found that when the shape of the adjacent portion 31b in a plan view is a lattice shape, the vibration level of the first resonance of the beam 10 can be reduced most in the model of Example 4 in which the rib pitch (Lr1, Lr2) is 100 mm. In this case, the first quasi-resonance of the damping material 31 exists in a frequency range close to the first resonance frequency of the beam 10.

[0118] From the above, when using a damping material 31 having a structure (waffle shape) in which recesses (non-proximal portions) 31a and proximal portions 31b are alternately repeated in two directions (X direction and Y direction) perpendicular to the Z direction, it is considered most desirable to match the quasi-resonance of the non-proximal portions 31a, which are farther away from the beam 10 than the proximal portions 31b, with the primary resonance frequency of the beam 10 in order to obtain a vibration damping effect.

[0119] Although details are omitted, the inventors obtained results with the same tendency regardless of the magnitude of Dr in the damping material 31.

[0120] [Application example of vibration damping structure] Application examples of the vibration damping structures 1 to 3 of the first to third embodiments will be described with reference to Figs. 15 to 17.

[0121] (1) Example of application to a front pillar 101 of a vehicle body 100 FIG. 16 shows a cross section taken along line XVI-XVI in FIG.

[0122] As shown in Figure 16, when each of the vibration damping structures 1 to 3 of the first to third embodiments is applied to a front pillar 101 of a vehicle body 100, a vibration damping structure is formed by a pillar 1010, which is a long structural body, a pillar trim 1014 joined to the pillar 1010 from the inside of the vehicle body, and a wind seal 104 attached to the pillar trim 1014.

[0123] The pillar 1010 has an outer panel 1011 and an inner panel 1013 which form a closed cross section, and a reinforcement 1012 which is disposed so as to be sandwiched between the outer panel 1011 and the inner panel 1013. A front wind seal 103 is attached to the front portion of the pillar 1010, and a door seal 105 is attached to the rear portion of the pillar 1010.

[0124] The pillar trim 1014 has a main body 1015 and a clip (mechanical fastening portion) 1016. Although not shown in Fig. 16, the foam portion 213 of the second embodiment may be provided on the portion of the main body 1015 on the inner panel 1013 side. Also, although the main body 1015 of the pillar trim 1014 is shown as a plate in Fig. 16, the damping material 31 of the third embodiment can also be applied.

[0125] In the pillar trim 1014, the main body 1015 is joined to the pillar 1010 by a clip 1016, and the portion joined by the clip 1016 is a joined portion, and the other portion is a separated portion (non-jointed portion). That is, in this application example, the main body 1015 of the pillar trim 1014 is joined to the pillar 1010 only via the clip 1016, and the other portion of the main body 1015 is not directly joined to the pillar 1010.

[0126] A plurality of clips 1016 are provided in a direction perpendicular to the paper surface of Fig. 16. The plurality of clips 1016 may be arranged at equal intervals or at non-equidistant intervals in the direction in which the pillar 1010 extends (the direction perpendicular to the paper surface of Fig. 16).

[0127] The front wind seal 103 is joined to a main body 1015 of the pillar trim 1014 and is disposed with a small gap between it and the pillar 1010. This contributes to vibration damping of the pillar 1010 in the same manner as the foam material 213 of the second embodiment.

[0128] In the front pillar 101 having the above-described structure, a vibration damping structure is formed by the pillar 1010, the pillar trim 1014, and the wind seal 104, making it possible to effectively dampen the vibration of the pillar 1010.

[0129] (2) Example of application to center pillar 102 of vehicle body 100 FIG. 17 shows a cross section taken along line XVII-XVII in FIG.

[0130] As shown in Figure 17, when each of the vibration damping structures 1 to 3 of the first to third embodiments is applied to a center pillar 102 of a vehicle body 100, a vibration damping structure is formed by a pillar 1020, which is a long structural body, and a pillar trim 1024 joined to the pillar 1020 from the inside of the vehicle body.

[0131] The pillar 1020 has an outer panel 1021 and an inner panel 1023 that form a closed cross section, and a reinforcement 1022 that is disposed so as to be sandwiched between the outer panel 1021 and the inner panel 1023. Door seals 106, 107 are attached to the front and rear portions of the pillar 1020, respectively.

[0132] The pillar trim 1024 has a main body 1025 and a clip (mechanical fastening portion) 1026. Although not shown in Fig. 17, the foam portion 213 of the second embodiment may be provided on the portion of the main body 1025 on the inner panel 1013 side. Also, in Fig. 17, the main body 1025 of the pillar trim 1024 is shown as a plate-like body, but the damping material 31 of the third embodiment may be applied.

[0133] In the pillar trim 1024, the main body 1025 is joined to the pillar 1020 by a clip 1026, and the portion joined by the clip 1026 is a joined portion, and the other portion is a separated portion (non-jointed portion). That is, in this application example as well, the main body 1025 of the pillar trim 1024 is joined to the pillar 1020 only via the clip 1026, and the other portion of the main body 1025 is not directly joined to the pillar 1020.

[0134] A plurality of clips 1026 are provided in a direction perpendicular to the paper surface of Fig. 17 (the vertical direction of the vehicle body 100). The plurality of clips 1026 may be disposed at equal intervals or may be disposed at non-equidistant intervals in the vertical direction of the vehicle body 100 in which the pillar 1020 extends.

[0135] Even in the center pillar 102 having the above-described structure, a vibration damping structure is formed by the pillar 1020 and the pillar trim 1024, making it possible to effectively dampen the vibration of the pillar 1020.

[0136] Although the above describes an example of applying the vibration damping structure to the front pillar 101 and center pillar 102 of the vehicle body 100, the vibration damping structure of the present invention can be applied as appropriate to any portion of the vehicle body where long members are arranged.

[0137] In addition, although the above describes the structure of the car body 100 as an application example of the vibration damping structures 1 to 3, the present invention is not limited thereto. For example, in addition to car bodies, the vibration damping structures can be applied to parts of buildings, electrical appliances, ships, airplanes, and the like.

[0138] [Variation 1] The vibration damping structure according to the first modification will be described with reference to Fig. 18. Note that Fig. 18 illustrates only the damping material 35, which is a difference from the vibration damping structure 3 according to the third embodiment.

[0139] As shown in Fig. 18, the damping material 35 of the vibration damping structure according to this modification has a plurality of non-adjacent parts (recesses) 35a and a plurality of adjacent parts (rib-shaped parts) 35b on the side (upper side in the Z direction) that is joined to the beam 10. Note that Fig. 18 omits the illustration of the part where the damping material 35 is joined to the beam 10.

[0140] The non-proximal portions 35a are formed between adjacent proximal portions 35b in the X direction and in a direction perpendicular to the paper surface of FIG. 18, and are disposed farther away from the beam 10 in the Z direction than the proximal portions 35b.

[0141] The damping material 35 of the vibration damping structure according to this modification also has a plurality of recesses 35c and rib-like portions 35d on the side opposite to the side joined to the beam 10 (the lower side in the Z direction in FIG. 18). The arrangement of the recesses 35c and the rib-like portions 35d is the same as the arrangement of the non-proximal portions 35a and the proximal portions 35b in a direction perpendicular to the Z direction. When the non-proximal portions 35a and the recesses 35c are viewed in a plan view from the Z direction, the non-proximal portions 35a and the recesses 35c are arranged to overlap each other.

[0142] In the vibration damping structure according to this modification, even when the beam 10 is joined to the damping material 35 from one side in the Z direction and another skeletal member is joined from the other side in the Z direction, the resonance in the non-proximal portion 35a is not easily hindered. That is, since the recess 35c that is separated from the other skeletal member is formed in the region below the non-proximal portion 35a in the Z direction, even if another skeletal member is joined, the resonance mode of the non-proximal portion 35a is not easily hindered, which is advantageous in accumulating strain energy in the joint (not shown) and the proximal portion 35b of the damping material 35 and is further advantageous in obtaining an effect related to vibration damping.

[0143] [Variation 2] The vibration damping structure according to the second modification will be described with reference to Fig. 19. Note that Fig. 19 also shows only the damping material 41, which is a difference from the vibration damping structure 3 according to the third embodiment.

[0144] As shown in Fig. 19, the damping material 41 of the vibration damping structure according to this modification is composed of a plate-like member 410 and a lattice-like member 411 joined together. The plate-like member 410 is a plate-like member having a thickness, and is arranged along the beam 10. The lattice-like member 411 has a proximity portion 311b formed in a lattice shape, and a plurality of non-proximal portions 411a each having an opening above and below in the Z direction. The proximity surface 411c of the lattice-like member 411 is arranged in proximity to the outer surface of the beam 10, and is joined to the main surface 410a of the plate-like member 410 at a joining surface 411d.

[0145] In the vibration damping structure of this modified example, the damping material 41 is formed by combining a plate-shaped member 410 and a lattice-shaped member 411, and since it has a similar structure to the vibration damping structure 3 of the third embodiment described above, it is possible to obtain the same effects as those described above.

[0146] [Variation 3] The vibration damping structure according to the third modified example will be described with reference to Fig. 20. Note that Fig. 20 also shows only the damping material 45, which is a difference from the vibration damping structure 3 according to the third embodiment.

[0147] As shown in Fig. 20, the damping material 45 of the vibration damping structure according to this modification has a plate-shaped portion 45c and multiple columnar portions 45a. The plate-shaped portion 45c is a plate-shaped member having a thickness, and is arranged along the beam 10. The multiple columnar portions 45a each have a cylindrical external shape, and are erected on the Z-direction upper side of the plate-shaped portion 45c with intervals between them. The plate-shaped portion 45c and the multiple columnar portions 45a may be integrally formed, or may be joined to each other.

[0148] In the vibration damping structure according to this modified example, the damping material 45 is arranged so that the upper portions of the multiple columnar portions 45a in the Z direction are close to the outer surface of the beam 10. In the damping material 45, in the region between the plate-like portion 45c and the outer surface of the beam 10, the spaces between the adjacent columnar portions 45a form non-adjacent portions 45b.

[0149] 20, the vibration damping structure according to this modification includes a damping material 45 having a plate-like portion 45c and a plurality of columnar portions 45a, which makes it possible to reduce the rigidity of the damping material 45 compared to the case of using damping materials 31, 35, 41 having lattice-like adjacent portions 31b, 35b, 411b as in the third embodiment and modifications 1 and 2. Therefore, the vibration damping structure according to this modification can be used to control the rigidity and resonant frequency of the vibration damping structure.

[0150] In the present invention, it is also possible to appropriately combine the configurations of the first to third embodiments and the first to third modifications.

[0151] In the first to third embodiments and the first to third modifications, the beam 10 having an internal closed cross-sectional structure is used as an example of the first member, but the present invention is not limited to this. For example, a solid bar member or a long member having an open cross-sectional structure may be used as the first member. In addition, the first member does not necessarily have to be a member extending in a straight line, and a long member formed to draw a curve or a long member bent in a crank shape may be used. [Explanation of symbols]

[0152] 1~3 Vibration damping structure 10 Beam (first member) 11, 21, 31, 35, 41, 45 Damping material (second component) 11a Separated part (non-joined part) 11b Joint 31a, 35a, 411a Non-adjacent parts 31b, 35b, 411b adjacent area 45a Columnar section (nearby section) 45b Separated portion (non-adjacent portion) 100 Body 101 Front pillar 102 Center pillar 104 Wind Seal 112, 212, 1016, 1026 Clips (mechanical fastening components) 211 Main body 213 Foaming section 410 Plate-shaped members 411 Lattice Members 1010, 1020 Pillar (first member) 1014, 1024 Pillar trim (second component)

Claims

1. A first member having an elongated shape which is a structure; a second member disposed along the first member and joined to the first member; Equipped with The second member is a plurality of joints joined to the first member at intervals in a first direction in which the first member extends; one or more non-jointed portions that are not joined to the first member and are disposed adjacent to the joint portion in the first direction; having the second member is formed to have higher attenuation than the first member, and a first-order resonant frequency of the second member is equal to or lower than a resonant frequency of the first member, The non-jointed portion of the second member is adjacent portions each adjacent to the first member in a direction perpendicular to the first direction; a non-proximal portion disposed adjacent to the proximal portion in the first direction and spaced apart from the first member in the orthogonal direction relative to the proximal portion; having Vibration damping structure.

2. The vibration damping structure according to claim 1, When the second member is viewed in a plan view from the orthogonal direction, the proximity portion has a lattice shape. Vibration damping structure.

3. The vibration damping structure according to claim 2, The adjacent portion of the second member is provided in a columnar shape from the non-adjacent portion toward the first member in the orthogonal direction. Vibration damping structure.

4. A vibration damping structure according to any one of claims 1 to 3, The joint of the second member is disposed at an antinode position of at least one of a first resonance and a second resonance in the first member. Vibration damping structure.

5. A vibration damping structure according to any one of claims 1 to 4, The second member is formed using a porous material. Vibration damping structure.

6. A first member having an elongated shape which is a structure; a second member disposed along the first member and joined to the first member; Equipped with The second member is a plurality of joints joined to the first member at intervals in a first direction in which the first member extends; one or more non-jointed portions that are not joined to the first member and are disposed adjacent to the joint portion in the first direction; having the second member is formed to have higher attenuation than the first member, and a first-order resonant frequency of the second member is equal to or lower than a resonant frequency of the first member, The joint of the second member is disposed at an antinode position of at least one of a first resonance and a second resonance in the first member. Vibration damping structure.

7. A first member having an elongated shape which is a structure; a second member disposed along the first member and joined to the first member; Equipped with The second member is a plurality of joints joined to the first member at intervals in a first direction in which the first member extends; one or more non-jointed portions that are not joined to the first member and are disposed adjacent to the joint portion in the first direction; having the second member is formed to have higher attenuation than the first member, and a first-order resonant frequency of the second member is equal to or lower than a resonant frequency of the first member, The second member is formed using a porous material. Vibration damping structure.

8. A vibration damping structure according to any one of claims 1 to 7, the first member is a pillar of a vehicle body, The second member is a pillar trim attached to the pillar on the inside of the vehicle interior. Vibration damping structure.

9. A first member having an elongated shape which is a structure; a second member disposed along the first member and joined to the first member; Equipped with The second member is a plurality of joints joined to the first member at intervals in a first direction in which the first member extends; one or more non-jointed portions that are not joined to the first member and are disposed adjacent to the joint portion in the first direction; having the second member is formed to have higher attenuation than the first member, and a first-order resonant frequency of the second member is equal to or lower than a resonant frequency of the first member, the first member is a pillar of a vehicle body, The second member is a pillar trim attached to the pillar on the inside of the vehicle interior. Vibration damping structure.

10. A vibration damping structure according to any one of claims 6 to 9, The non-jointed portion of the second member is disposed to face the first member in a spaced-apart state in a direction perpendicular to the first direction. Vibration damping structure.

11. The vibration damping structure according to claim 10, The second member is A main body portion disposed in a state spaced apart from the first member in the orthogonal direction; a mechanical fastening portion that mechanically fastens the main body portion and the first member; having the joint portion is a portion joined to the first member by the mechanical fastening portion, The non-jointed portion is a portion of the main body excluding a portion joined to the first member by the mechanical fastening portion. Vibration damping structure.

12. A vibration damping structure according to any one of claims 1 to 11, The plurality of joints are arranged linearly along the first direction. Vibration damping structure.

13. A vibration damping structure according to any one of claims 1 to 12, The first member has a closed cross section in a direction perpendicular to the first direction. Vibration damping structure.

14. A vibration damping structure according to any one of claims 1 to 13, The first resonance frequency of the second member is set to be equal to or lower than the first or second resonance frequency of the first member. Vibration damping structure.

15. A vibration damping structure according to any one of claims 1 to 14, The first resonance frequency of the second member is set to be substantially the same as the first resonance frequency or the second resonance frequency of the first member. Vibration damping structure.

16. A vibration damping structure according to any one of claims 1 to 15, The first resonance frequency of the second member is set to be substantially the same as the first resonance frequency of the first member. Vibration damping structure.

17. A vibration damping structure according to any one of claims 1 to 16, The first member is formed using a metal material, The second member has a loss factor of 0.01 or more. Vibration damping structure.

Images