JP4124369B2 - Dynamic damper - Google Patents

Description

  The present invention relates to a dynamic damper, and more particularly to a dynamic damper capable of suppressing audible discomfort due to a hitting sound.

  Conventionally, various dynamic dampers have been used in vehicles in order to reduce harmful vibrations generated from an engine, a rotating shaft, and the like. This dynamic damper can effectively reduce the harmful vibration by tuning the resonance frequency (natural frequency) in accordance with the peak frequency of the harmful vibration in question.

  In recent years, seats mounted on vehicles have been diversified, and seat vibration problems have occurred due to lack of rigidity and the like. Dynamic dampers are being used.

  FIG. 6 shows a specific example thereof, and is a diagram showing a vehicle seat 200 and a dynamic damper 202 attached to a seat back 201. As shown in detail in FIG. 7, the dynamic damper 202 includes a mass member 204 that is one lump having a large mass, and a vibration-proof base 206 composed of a pair of upper and lower rubber-like elastic bodies.

  The dynamic damper 202 is attached to the seat back 201 of the vehicle via a bracket 210 having a pair of upper and lower attachment portions 208. A bolt hole 209 is formed in the center of each of the pair of upper and lower mounting portions 208. The bracket 210 is superimposed on the mounting position of the seat back 201 of the vehicle, and is fixed to the seat back 201 with a fixing bolt inserted into the bolt hole 209. The dynamic damper 202 has a structure that suppresses harmful vibration generated in the seat back 201 of the vehicle by a resonance operation of a vibration system constituted by the mass member 204 and the vibration isolation base 206.

  Here, the peak frequency of harmful vibration generated in the seat back of the vehicle seat is generally about 10 Hz to 30 Hz. In order to tune the resonance frequency of the vibration system constituted by the mass member 204 and the vibration isolation base 206 to the peak frequency of the harmful vibration described above, the vibration isolation base 206 constituting the vibration system has a rubber shape with a low spring constant k. An elastic body is used. As a result, the mass member 204 is likely to be largely displaced relative to the bracket 210 during vibration input.

  Therefore, as shown in FIG. 7, the bracket 210 is provided with a regulating plate 212 that is opposed to the one surface of the mass member 204 while being spaced apart in the Y direction. By providing such a restriction plate 212, the relative displacement of the mass member 204 with respect to the bracket 210 at the time of vibration input is restricted, and mutual interference between the mass member 204 and other members can be prevented, thereby preventing damage. it can.

That is, when the mass member 204 is largely displaced relative to the bracket 210 at the time of vibration input, the mass member 204 hits the restricting plate 212 and further relative displacement is restricted. A hitting sound is generated. In the conventional dynamic damper 202, in order to alleviate this hitting sound, a urethane-based cushioning material 213 is provided on the surface of the mass member 204, and contrivances such as reducing the impact generated between the mass member 204 and the bracket 210 are elaborated. It had been.
JP 2004-245314 A

  However, as shown in FIG. 7B, in the conventional dynamic damper 202, the restriction plate 212 facing one surface of the mass member 204 is connected to the mounting portion 208 at both ends, and the seatback 201 is connected by the mounting portion 208. It was fixed to. That is, since both ends of the restricting plate 212 are fixed ends, the hitting sound generated on the restricting plate 212 becomes annoying with a high frequency, and even if the cushioning member 213 is provided on the surface of the mass member 204, the audibility due to the hitting sound. The above discomfort could not be reduced sufficiently.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a dynamic damper capable of suppressing audible discomfort due to hitting sound.

In order to achieve this object, the dynamic damper according to claim 1 connects a mass member as a mass body, a bracket attached to a support portion of a seat back of a vehicle seat, the bracket and the mass member. A vibration isolating base composed of a rubber-like elastic body, comprising a mass member as a mass body, a bracket attached to a support portion of a seat back of a vehicle seat, the bracket and the mass member, And a mass damper, wherein the mass member connects a pair of wide surfaces perpendicular to the Y direction and the pair of wide surfaces to provide vibration isolation. and a side portion having a receiving surface to which one end of the substrate is connected, wherein the bracket, while being connected to the mass member separately and independently of one another, the mass A regulating portion that is spaced apart and opposed to the material in the Z direction perpendicular to the Y direction, and rises from the end opposite to the one end of the regulating portion along the side surface of the mass member, A first bracket and a second bracket having an upright portion having a support surface to which the other end is connected , and a mounting portion that extends from an end opposite to the restricting portion of the upright portion and is attached to the seat back. The restricting portion provided on the first bracket is opposed to one end of the mass member in the Z direction, and the restricting portion provided on the second bracket is configured in the Z direction. facing and to one end of the mass member has a gap between the regulating portion provided in the first bracket, opposite end and said mounting portion in said regulating portion of the mass member with a free end One Have overlapping portions in serial broad surface and the Y-direction, said and said supporting surface receiving surface inclined with respect to the Y direction in parallel to the X direction perpendicular to the Y direction and the Z-direction, from the Y-direction The anti-vibration base is connected so that the receiving surface and the support surface have an overlapping portion when viewed .

  The dynamic damper according to claim 2 is the dynamic damper according to claim 1, wherein the first bracket and the second bracket have the same shape.

Dynamic damper according to claim 3, wherein, in the dynamic damper according to claim 1 or 2, wherein the first bracket and the second bracket, be fitted to the support part side engaging portion provided on the support unit bracket Each has a side fitting portion.

A dynamic damper according to a fourth aspect is the dynamic damper according to the third aspect , wherein one of the bracket side fitting portion and the support portion side fitting portion is formed by a protrusion protruding to the other, and the other is It is comprised by the hollow which fits the said protrusion.

According to the dynamic damper of the first aspect, when the mass member is relatively displaced in the first direction with respect to the bracket by the vibration input in the first direction, the mass member hits the restricting portion and the relative displacement amount is regulated, and the hitting sound is generated. May occur. Here, since one end on the opposite side of the attachment portion in the restricting portion is a free end, the timbre of the hitting sound is changed to a tone with low discomfort compared to the case where both ends of the restricting portion are fixed ends. Therefore, it is possible to suppress unpleasant discomfort due to the hitting sound.
Further, since the restricting portion provided on the second bracket has a gap with the restricting portion provided on the first bracket, the restricting portion is compared with a case where the restricting portion is an integral part having no gap. Thus, the area of the entire regulation section is small. Therefore, there is an effect that the volume of the hitting sound generated when the mass member hits the restricting portion is reduced, and the unpleasant discomfort due to the hitting sound can be suppressed.

  According to the dynamic damper of the second aspect, in addition to the effect of the dynamic damper according to the first aspect, the first bracket and the second bracket have the same shape, so the types of brackets are reduced by half and are inexpensive. In addition, there is an effect that management is easy.

According to the dynamic damper according to claim 3, in addition to the effects of the dynamic damper according to claim 1 or 2, wherein the first bracket and the second bracket, the support part side fitting provided in the support portion Since the bracket side fitting portion that fits with the portion is provided, there is an effect that the first bracket and the second bracket can be prevented from rotating or swinging with respect to the support portion. The first bracket and the second bracket are separately and independently connected to the mass member, and the vibration of the mass member is transmitted to each via the anti-vibration base, so the support portion side fitting portion provided in the support portion In the case where the bracket-side fitting portion to be fitted is not provided, the first bracket and the second bracket are easy to rotate or swing with respect to the support portion.

According to the dynamic damper of claim 4 , in addition to the effect produced by the dynamic damper of claim 3 , one of the bracket side fitting portion and the support portion side fitting portion is a protrusion that protrudes to the other. In the state where the first bracket and the second bracket are in the mounting position with respect to the support portion of the seat back, the other direction is along the surface of the support portion. The movement of the protrusions in is restricted by the inner surface of the recess. Therefore, there is an effect that the rotation or swinging of the first bracket and the second bracket with respect to the support portion is reliably suppressed.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is a bottom view of a dynamic damper 1 according to an embodiment of the present invention, FIG. 2 is a side view of the dynamic damper 1, and FIG. 3 is a top view of the dynamic damper.

  The dynamic damper 1 is attached to a seat back of a vehicle seat and is a vibration isolator for suppressing vibration of the seat back. As shown in FIGS. 1 to 3, a mass member 2 as a mass body, It mainly includes a bracket 3 attached to a seat back of a vehicle seat, and an anti-vibration base 4 that connects the bracket 3 and is made of a rubber-like elastic body. The mounting position of the dynamic damper 1 to the seat back is the same as that of the conventional dynamic damper shown in FIG.

  The mass member 2 includes a rectangular block-shaped metal mass body 2a having a rectangular surface in a plan view shown in FIG. 1, a metal receiving surface member 2b welded to a side surface of the mass body 2a, and the mass member 2a. It consists of the main rubber | gum 2a and the covering rubber layer 14 which coat | covers the surface of the receiving surface member 2b, and has predetermined mass m.

  Hereinafter, in the plan view shown in FIG. 1 and FIG. 3, the short side direction (left-right direction in FIG. 1) of the rectangular surface of the mass body 2a is referred to as the X direction, and the long direction (up-down direction in FIG. Called. The direction perpendicular to the X direction and the Z direction (the direction perpendicular to the plane of FIG. 1) is referred to as the Y direction (see FIG. 2). The dynamic damper 1 is attached to a vehicle seat back such that the X direction corresponds to the left-right direction of the vehicle, the Y direction corresponds to the front-rear direction of the vehicle, and the Z direction corresponds to the up-down direction of the vehicle. The Y direction corresponds to the first direction of the claims, and the Z direction corresponds to the second direction of the claims.

  Further, as shown in FIG. 2, the mass member 2 includes a pair of wide surfaces 5 perpendicular to the Y direction, and a side surface portion 6 connecting the pair of wide surfaces 5. The side surface portion 6 includes a side surface 6a that is perpendicular to the pair of wide surfaces 5, and an inclined portion 6b that protrudes from both end sides in the Z direction of one wide surface 5 and that is parallel to the X direction and inclined with respect to the Y direction. Have. The inclined portion 6b is provided with a receiving surface 7 to which one end of the vibration isolating base 4 is connected.

  As shown in FIG. 2, the bracket 3 includes a first bracket 3 a and a second bracket 3 b that are connected to the mass member 2 separately and independently from each other. Here, “separate and independent from each other” means a state where the surfaces of each other are not in contact with each other. In addition, the 1st bracket 3a and the 2nd bracket 3b have the mutually same shape, and as shown in FIG. 1, in the dynamic damper 1, it connects with each other by the Z direction both sides of the mass member 2 symmetrically. Moreover, the 1st bracket 3a and the 2nd bracket 3b have the 1st direction control board 9, the upright part 10, and the attaching part 11, respectively, integrally.

  The first direction regulating plate 9 is a plate-like member that faces the one wide surface 5 of the mass member 2 while being spaced apart in the Y direction and perpendicular to the Y direction. As shown in FIGS. 2 and 3, in the first direction regulating plate 9 provided on the first bracket 3a and the first direction regulating plate 9 provided on the second bracket 3b, there is a gap G between each. The one end 9a opposite to the mounting portion 11 side described later is a free end.

  The first direction restricting plate 9 provided on the first bracket 3a is opposed to one end portion in the Z direction of the one wide surface 5 of the mass member 2, and is provided on the second bracket 3a. 9 opposes the other end part in the Z direction of one wide surface 5 of the mass member 2. The relative displacement of the mass member 2 with respect to the bracket 3 in the Y direction is restricted by the first direction restricting plates 9 provided on the first bracket 3a and the second bracket 3b.

  The upright portion 10 is a member that rises along the side surface portion 6 of the mass member 2 from the end portion opposite to the one end 9 a of the first direction regulating plate 9. Further, the upright portion 10 is an end portion on the first direction regulating plate 9 side, which is a support wall portion 10 a that is parallel to the X direction and inclined with respect to the Y direction, and an end portion on the opposite side to the first direction regulating plate 9. The connecting portion 10b is parallel to the X direction and the Y direction. The support wall 10a is provided with a support surface 10c to which the other end of the vibration isolating base 4 is connected (see FIG. 2). The upright portion 10 regulates the relative displacement amount of the mass member 2 with respect to the bracket 3 in the Z direction.

  The attachment portion 11 extends from the end of the upright portion 10 opposite to the first direction restricting plate 9, and a through hole 12 and a rotation prevention pin 13 are formed. As will be described later with reference to FIG. 5, the first bracket 3 a and the second bracket 3 b are attached to the seat back support portion 20 of the vehicle seat by a fixing bolt 21 a and a nut 21 b inserted through the through hole 12. .

  Here, as shown in FIG. 3, the pair of through-holes 12 and the pair of rotation prevention pins 13 include the center line 1z of the mass member 2 parallel to the Z direction and the center line lx of the mass member 2 parallel to the X direction. The first bracket 3a and the second bracket 3b are provided so as to be symmetrical with each other with respect to the intersection O with the reference point. In addition, the further structure of the through-hole 12 and the rotation prevention pin 13 is demonstrated in detail later with reference to FIG.

  In the present embodiment, the thin covering rubber layer 14 is attached to the mass member 2 and the bracket 3 to cover the entire outer peripheral surface of the mass member 2 and a part of the bracket 3. The vibration-proof substrate 4 is formed integrally with the rubber layer 14. That is, the covering rubber layer 14 and the vibration isolating base 4 are formed by injection-filling a rubber material into the molding cavity and vulcanizing it with the mass member 2 and the bracket 3 positioned and set in a molding cavity of a predetermined molding die. At the same time as the vulcanization molding, the mass member 2 and the bracket 3 are vulcanized and bonded.

  The anti-vibration base 4 connects the receiving surface 7 provided on the mass member 2 and the support surface 10 c provided on the bracket 3. The dynamic damper 1 tunes the resonance frequency of the vibration system composed of the mass member 2 and the vibration isolation base 4 in accordance with the peak frequency of harmful vibration that occurs in the seat back, thereby causing harmful vibration that occurs in the seat back. Can be effectively reduced.

  The resonance frequency of the vibration system is determined based on Equation 1 above. More specifically, the resonance frequency fx in the X direction is tuned based on the spring constant kx in the X direction of the vibration isolation base 4 and the mass m of the mass member 2, and the resonance frequency fy in the Y direction is 4 is tuned based on the Y-direction spring constant ky and the mass m of the mass member 2. Since the mass m of the mass member 2 is common, in order to increase the resonance frequency fy in the Y direction compared to the resonance frequency fx in the X direction, the Y direction with respect to the spring constant kx in the X direction of the vibration isolation base 4 It is necessary to increase the ratio of the spring constant ky.

  Since the receiving surface 7 and the support surface 10c to which the vibration isolating base 4 is connected are parallel to the X direction, when the mass member 2 is relatively displaced in the X direction with respect to the bracket 3, the vibration isolating base 4 is subjected to shear deformation. It is. On the other hand, the receiving surface 7 and the support surface 10c are inclined with respect to the Y direction, and the anti-vibration base 4 is connected so that the receiving surface 7 and the support surface 10c overlap each other when viewed from the Y direction. Therefore, when the mass member 2 is relatively displaced in the Y direction with respect to the bracket 3, the vibration isolation base 4 connected to the receiving surface 7 and the support surface 10 c is subjected to compression or tensile deformation.

  Therefore, the ratio of the spring constant ky in the Y direction to the spring constant kx in the X direction of the vibration isolation base 4 becomes large. As a result, in the vibration system composed of the mass member 2 and the vibration isolation base 4, the resonance frequency in the Y direction is set to a frequency range larger than the resonance frequency in the X direction while tuning the resonance frequency in the X direction to a predetermined frequency range. Can be tuned. For example, when the peak frequency of harmful vibration generated in the X direction in the seat back is 19 Hz and the peak frequency of harmful vibration generated in the Y direction is 29 Hz, the ratio of the peak frequency in the Y direction to the X direction is about 1. Since the spring ratio (ky / kx) of the anti-vibration base 4 is about 1.5, the resonance frequency of the vibration system composed of the mass member 2 and the anti-vibration base 4 is 19 Hz in the X direction, Y Tune to 29Hz in the direction. As a result, the dynamic damper 1 can simultaneously reduce harmful vibration in a predetermined frequency range that occurs in the X direction and harmful vibration that occurs in the Y direction in a frequency range that is greater than the resonance frequency in the X direction.

  The receiving surface 7 provided on the mass member 2 and the support surface 10c provided on the bracket 3 are configured in parallel to each other. Thereby, when the mass member 2 is relatively displaced with respect to the bracket 3, it is possible to suppress the strain distribution in the vibration isolating base 4 from becoming non-uniform and to concentrate the strain on the portion, thereby ensuring durability. .

  Further, the receiving surface 7 is provided on the side surface portion 6 (inclined portion 6 b) of the mass member 2, and the support surface 10 c is the end of the rising portion 10 rising toward the side surface portion 6 of the mass member 2 on the first direction regulating plate side 9. Since it is provided in the portion, the dynamic damper 1 can be prevented from being enlarged in the Y direction.

  That is, as in the dynamic damper 1 of the present embodiment, in order to increase the ratio of the spring constant ky in the Y direction to the spring constant kx of the vibration isolation base 4, for example, the wide surface 5 of the mass member 2 and its wide width It is conceivable to connect the anti-vibration base 4 between the first direction regulating plate 9 facing the surface 5 and perpendicular to the Y direction. However, with this configuration, it is necessary to provide a large gap between the wide surface 5 of the mass member 2 and the first direction regulating plate 9 of the bracket 3 so that the vibration isolating base 4 is interposed. Increasing the size in the Y direction (front-rear direction of the vehicle) is unavoidable and is not preferable as being attached to the seat back.

  On the other hand, according to the dynamic damper 1 of the present embodiment, the receiving surface 7 provided on the side surface portion 6 of the mass member 2, and the support surface 10 c provided on the rising portion 10 rising toward the side surface portion 6. Since the anti-vibration base 4 is interposed therebetween, the dynamic damper 1 can be prevented from increasing in size in the Y direction (the longitudinal direction of the vehicle).

  Further, in the bracket 3, the upright portion 10 provided between the first direction restricting plate 9 and the attachment portion 11 is effectively used, and the end portion of the upright portion 10 on the first direction restricting plate 9 side in the Y direction. Since the support surface 10c (support wall portion 10a) is provided by being inclined with respect to the X direction, no new space or member is required to provide the support surface 10c, and the dynamic damper 1 is compact. And it can be advantageous in terms of cost.

  Next, the mass body 2a and the receiving surface member 2b constituting the mass member 2 will be described in detail with reference mainly to FIG. The mass body 2a is configured in a rectangular block shape, and a receiving surface member 2b is welded to a pair of side surfaces parallel to the XY plane.

  The receiving surface member 2b is a member having a circumscribed surface 2c attached to the side surface of the mass body 2a and a receiving surface constituting surface 2d that is inclined at a predetermined angle with respect to the Y direction and parallel to the X direction. The receiving surface constituting surface 2d is bent with respect to 2c. In addition, the inclined part 6b is formed in the side part 6 of the mass member 2 by the receiving surface member 2b. The receiving surface constituting surface 2d forms a receiving surface 7 that is inclined at a predetermined angle with respect to the Y direction and parallel to the X direction.

  With reference to FIG. 4, the relationship between the angle θ of the receiving surface 7 with respect to the Y direction and the spring constant k of the vibration isolation base 4 will be described. FIG. 4A is an enlarged view of the side surface portion 6 of the mass member 2 and shows a state in which the receiving surface 7 is inclined at an angle θ1 with respect to the Y direction. FIG. 4B is an enlarged view of the side surface portion 6 of the mass member 2, and shows a state in which the receiving surface 7 is inclined at an angle θ2 (θ2> θ1) with respect to the Y direction.

  As shown in FIG. 4, the larger the angle θ of the receiving surface 7 and the support surface 10c with respect to the Y direction, the greater the proportion of the compression or tension component in the elastic deformation of the vibration isolating substrate 4 in the Y direction. The spring constant ky in the direction is higher than the spring constant kx in the X direction. That is, by adjusting only the angle θ with respect to the Y direction while keeping the receiving surface 7 and the support surface 10c parallel to the X direction, only the spring constant ky in the Y direction can be changed without changing the spring constant kx in the X direction. It can be.

  Therefore, when tuning the dynamic damper 1 of the present embodiment, first, the volume and rigidity of the vibration-proof base 4 are selected so that the resonance frequency fx in the X direction becomes a desired frequency. Thereafter, by adjusting only the angle θ with respect to the Y direction while keeping the receiving surface 7 and the support surface 10c parallel to the X direction, the resonance frequency fy in the Y direction can be set to a desired value without changing the resonance frequency fx in the X direction. Can be tuned to frequency.

  Further, according to the dynamic damper 1 of the present embodiment, the mass body 2a and the receiving surface member 2b are separate from each other. Therefore, only the receiving surface member 2b is replaced during tuning, so that the receiving surface 7 The resonance frequency fy in the Y direction can be tuned by changing the angle θ with respect to the Y direction. On the other hand, as the mass body 2a, a rectangular block that is easily available can be used in common, which is advantageous in terms of cost. When the receiving surface member 2b is not provided as a separate body but is provided integrally with the mass body 2a, a plurality of types of mass bodies 2a with different angles of the receiving surface 7 must be prepared. Cost.

  In addition, as the mass main body 2a, a rectangular block shape that is easily available can be used in common, so that a plurality of types in which the angle of the receiving surface 7 with respect to the Y direction is adjusted according to the target resonance frequency. In the case of producing a small amount of each of these dynamic dampers, it is advantageous in terms of cost. This is because, in order to process the mass body 2a integrally provided with the inclined portion 6b for constituting the receiving surface 7, a plurality of molds are required, or separate processes such as thermal forging and cold forging are required.

  With reference to FIG. 5, the attachment structure of the dynamic damper 1 of this embodiment is demonstrated. FIG. 5 is a cross-sectional view showing a cross section perpendicular to the X direction of the support portion 20 of the seat back and the dynamic damper 1 attached to the support portion 20. Here, the support part 20 is a member fixed to the seat back of the vehicle.

  As shown in FIG. 5, each of the first bracket 3a and the second bracket 3b is provided with a through hole 12 penetrating in the Y direction. Fixing bolts 21 for attaching and fixing the first bracket 3a and the second bracket 3b to the support portion 20 are inserted into the pair of through holes 12 provided in the first bracket 3a and the second bracket 3b. The On the other hand, the support portion 20 is provided with a pair of mounting holes 22 through which the fixing bolts 21a inserted through the through holes 12 are inserted.

  A nut 21 b is screwed onto the fixing bolt 21 a inserted through the through hole 12 and the mounting hole 22 on the back side of the support portion 20. Thereby, the 1st bracket 3a and the 2nd bracket 3b, and the support part 20 are fastened.

  Further, as shown in FIG. 5, in a state where the first bracket 3a and the second bracket 3b are in the mounting position with respect to the support portion 20, the surfaces of the first bracket 3a and the second bracket 3b that face the support portion 20 are opposed to each other. Each is provided with a rotation prevention pin 13 that is a projection that fits into a recess 23 described later.

  On the other hand, the support portion 20 has a pair of pivots provided respectively on the first bracket 3a and the second bracket 3b in a state in which the first bracket 3a and the second bracket 3b are attached to the support portion 20. A pair of depressions 23 to be fitted with the prevention pins 13 are provided in advance.

  When the first bracket 3a and the second bracket 3b of the dynamic damper 1 configured as described above are attached to the support portion 20 fixed to the seat back of the vehicle, prior to fastening by the fixing bolt 21a and the nut 21b. The pair of anti-rotation pins 13 provided on the first bracket 3a and the second bracket 3b are fitted into the depressions 23 provided in advance in the support unit 20.

  Thereby, the 1st bracket 3a and the 2nd bracket 3b of the dynamic damper 1 can be easily positioned in the attachment position with respect to the support part 20 fixed to the seat back of the vehicle. Further, after the positioning, the movement of the rotation prevention pin 13 is restricted by the inner surface of the recess 23, and the movement in the direction along the surface of the support 20 is suppressed, so that the first bracket 3a and the second bracket However, the rotation or swinging with respect to the support portion 20 is reliably suppressed. Therefore, in the positioned state, it is possible to stably perform the operation of inserting the fixing bolt 21a through the through hole 12 and the mounting hole 22 and screwing the nut 21b into the fixing bolt 21a. Therefore, the attachment work becomes easy.

  Here, as described with reference to FIGS. 1 to 3, a pair of pivots provided on the first bracket 3 a and the second bracket 3 b that are symmetrically connected to each other on both sides in the Z direction of the mass member 2. Since the prevention pins 13 are arranged symmetrically with respect to the intersection point O between the center line 1z of the mass member 2 parallel to the Z direction and the center line 1x of the mass member 2 parallel to the X direction, 1 does not cause the directionality in the Z direction and the X direction. Therefore, when the dynamic damper 1 is attached, when the pair of rotation prevention pins 13 are fitted into the depressions 23 provided in advance in the support portion 20, the directionality of the dynamic damper 1 in the Z direction and the X direction is set. Since there is no need to check, the installation work becomes easier.

  On the other hand, in the conventional dynamic damper, the rotation preventing pin is provided at the symmetrical position in the Z direction of the dynamic damper and at the same position in the X direction (see FIG. 7). Because of the prevention pin, left and right directionality occurred in the dynamic damper. As a result, at the time of mounting, when fitting a pair of rotation prevention pins to the depression provided in advance in the support portion, it is necessary to confirm and arrange the left and right directionality of the dynamic damper, The installation work was complicated.

  In addition, since the pair of through holes 12 provided in the first bracket 3a and the second bracket 3b are arranged symmetrically with respect to the intersection point O, the dynamic damper 1 Does not cause directivity in the Z direction and X direction. Therefore, when attaching the dynamic damper 1 to the support portion 20, it is not necessary to confirm the directivity of the dynamic damper 1 in the Z direction and the X direction, and the attaching operation becomes easy.

  Since both the first bracket 3a and the second bracket 3b are connected to the mass member 2 via the vibration isolation base 4, vibration is input to the seat back of the vehicle seat, and the mass member 2 and the vibration isolation are connected. When the vibration system constituted by the base 4 resonates, vibration is applied from the vibration-proof base 4 under the influence of the resonance. Here, when the first bracket 3a and the second bracket 3b are separated from each other, the first bracket 3a and the second bracket 3b are only fastened at one place by the fixing bolt 21a and the nut 21b, respectively. . Therefore, as compared with the case where the bracket is integrally formed, it is easily affected by vibration from the vibration isolating base 4 and rattling such as rotation and swinging around the axis of the fixing bolt 21a occurs. easy.

  Therefore, a pair of anti-rotation pins 13 fitted to the pair of recesses 23 provided on the support portion 20 are provided on the first bracket 3a and the second bracket 3b, and the first bracket 3a and the second bracket 3 with respect to the support portion 20 are provided. By suppressing the movement with the bracket 3b, even when the first bracket 3a and the second bracket 3b are separated from each other, the occurrence of rattling such as rotation or swing during vibration input is suppressed. .

  In addition, when the input vibration is particularly large, the mass member 2 may vibrate greatly and hit the first direction restricting plate 9 to generate a hitting sound, but the first direction restricting plate 9 is opposite to the mounting portion 11. One end 9a on the side is a free end. As a result, like the conventional dynamic damper (see FIGS. 6 and 7), the first direction restricting plate is provided integrally with the attachment portions at both ends in the Z direction, and both ends of the first direction restricting plate are fixed by the attachment portions. Compared with the case where it is made, since the timbre of the hitting sound can be changed to a timbre with low unpleasant feeling, it is possible to suppress the unpleasant feeling on the audibility due to the hitting sound.

  Further, since the first direction restricting plate 9 provided in the second bracket 3b has a gap G between the first direction restricting plate 9 provided in the first bracket 3a, the first direction restricting portion is provided with a gap. Compared to the case where the first direction regulating portion is not integrated, the area of the entire first direction regulating portion is small. Therefore, the volume of the hitting sound generated when the mass member 2 hits the first direction restricting plate 9 is reduced, and the unpleasant discomfort due to the hitting sound can be suppressed.

  Further, since the pair of rotation prevention pins 13 are arranged on the first bracket 3a and the second bracket 3b so as to be symmetrical with each other with respect to the intersection point O, the first bracket 3a and the second bracket The same shape can be used for 3b, and the types of brackets are halved and are inexpensive and easy to manage.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications and changes can be easily made without departing from the spirit of the present invention. Can be inferred.

  For example, in the dynamic damper 1 according to the present embodiment, the bracket side fitting portion is constituted by a protrusion (rotation prevention pin 13), and the support portion side fitting portion is constituted by a depression (depression portion 23). However, on the contrary, the bracket side fitting part may be constituted by a depression, and the support part side fitting part may be constituted by a protrusion.

It is a bottom view of the dynamic damper in one embodiment of the present invention. It is a side view of the dynamic damper shown in FIG. It is a top view of the dynamic damper shown in FIG. (A) is a figure which expands and shows the side part of a mass member, Comprising: It is a figure which shows the state in which a receiving surface inclines at angle (theta) 1 with respect to the Y direction, (b) is a figure which shows the side part of a mass member. It is a figure which expands and is a figure which shows the state which a receiving surface inclines at angle (theta) 2 with respect to the Y direction. It is sectional drawing which shows a cross section perpendicular | vertical to the X direction of the support part of a seat back, and the dynamic damper attached to the support part. It is a figure which shows the state in which the conventional dynamic damper was attached to the seat back of the vehicle seat. It is a figure which shows the conventional dynamic damper, (a) is a bottom view of a dynamic damper, (b) is a side view of a dynamic damper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dynamic damper 2 Mass member 3 Bracket 3a 1st bracket 3b 2nd bracket 4 Antivibration base | substrate 9 1st direction control board (control part)
9a One end (one end opposite the mounting part)
11 Mounting part 13 Anti-rotation pin (bracket side fitting part, protrusion)
20 Support part 21a Fixing bolt (fixing member)
23 Indentation part (support part side fitting part, indentation)
201 Seat back G Gap Y Y direction (first direction)
Z Z direction (second direction)

Claims (4)

A mass member (2) as a mass body, a bracket (3) attached to a support portion (20) of a seat back (201) of a vehicle seat, and the bracket (3) and the mass member (2) are connected. And a dynamic damper (1) comprising a vibration-proof substrate (4) composed of a rubber-like elastic body,
The mass member (2) connects a pair of wide surfaces (5) perpendicular to the Y direction and the pair of wide surfaces (5), and a receiving surface (1) to which one end of the vibration isolating base (4) is coupled. comprises side portions having 7) and (6),
The bracket (3) is connected to the mass member (2) separately and independently from each other , and is opposed to the mass member (2) with a spacing in the Z direction perpendicular to the Y direction. (9) rising from the end opposite to one end (9a) of the restricting portion (9) along the side surface (6) of the mass member (2), and the other end of the anti-vibration base (4) is An upright portion (10) having a support surface (10c) to be connected, and an attachment that extends from an end of the upright portion (10) opposite to the restricting portion (9) and is attached to the seat back (201) A first bracket (3a) having a portion (11) and a second bracket (3b) ,
The restriction portion (9) provided on the first bracket (3a) faces one end portion of the mass member (2) in the Z direction and the restriction portion provided on the second bracket (3b). The portion (9) has a gap between the one end portion of the mass member (2) in the Z direction and the regulating portion (9) provided in the first bracket (3a),
In the restricting portion (9) , one end (9a) opposite to the mounting portion (11) is a free end, and an overlapping portion is formed in the Y direction with the one wide surface (5) of the mass member (2). Have
The receiving surface (7) and the support surface (10c) are parallel to the Y direction and the X direction perpendicular to the Z direction and are inclined with respect to the Y direction, and the receiving surface when viewed from the Y direction. The vibration damper (4) is connected so that (7) and the support surface (10c) have an overlapping portion. The dynamic damper according to claim 1, wherein the first bracket (3a) and the second bracket (3b) have the same shape. The first bracket (3a) and the second bracket (3b) have a bracket-side fitting portion (13) fitted to a support-side fitting portion (23) provided in the support portion (20) , respectively. dynamic damper according to claim 1 or 2, characterized in that it has. One of the bracket side fitting portion (13) and the support portion side fitting portion (23) is constituted by a protrusion protruding to the other, and the other is constituted by a recess fitting with the protrusion. The dynamic damper according to claim 3 .

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