JP5364027B2 - Dynamic damper - Google Patents

Description

  The present invention relates to a dynamic damper connected to a steering wheel, and in particular, enables the volume of a mass member to be increased in accordance with the peak frequency of vibration of the steering wheel while preventing the generation of abnormal noise when driving on rough roads. It is related with the dynamic damper which can ensure the freedom degree of design.

  A dynamic damper is accommodated in the lower cover of the steering wheel in order to prevent idling and vibration during traveling from propagating to the steering wheel via the steering shaft. Patent Document 1 discloses a conventional dynamic damper.

  A conventional dynamic damper 100 will be described with reference to FIG. As shown in FIG. 9, the dynamic damper 100 includes a bracket 101 (bracket member) connected to a boss portion (not shown) of the steering wheel, and a mass member 102 (mass member) that functions as a mass body that attenuates vibration. And a rubber-like elastic body 104 (anti-vibration base) that connects the bracket 101 and the mass member 102 at a plurality of locations. The bracket 101 includes a flat plate portion 101a connected to the boss portion of the steering wheel and a bulging portion 101b bulging from the flat plate portion 101a, and the mass member 102 is connected to the flat plate portion 101a via a rubber-like elastic body 104. The first mass body 102a and the first mass body 102a project from the inner surface side (the front side in FIG. 9) of the lower cover (not shown) and are connected to the bulging portion 101b via the rubber-like elastic body 104. A two-mass body 102b is provided.

  When a large vibration is input to the steering shaft (not shown) during rough road traveling, the mass member 102 also vibrates greatly, and the second mass body 102b and the inner surface of the lower cover collide. When the second mass body 102b collides with the inner surface of the lower cover, an abnormal noise (collision noise) is generated. Therefore, the felt 121 is placed on the entire facing surface (the front surface in FIG. 9) of the second mass body 102b. Occurrence of abnormal noise is suppressed by sticking. Further, the bulge portion 101b of the bracket 101 is formed with a pair of stopper walls 113 which are bent from both ends of the bulge portion 101b and face both side surfaces of the second mass body 102b, thereby ensuring the rigidity of the bracket 101. Has been.

  By the way, the dynamic damper 100 is designed so that the mass (volume) of the mass member 102 and the spring constant of the rubber-like elastic body 104 are adjusted so that the resonance frequency thereof matches the peak frequency of the vibration of the steering wheel. Is done. In order to reduce the resonance frequency of the dynamic damper 100, it is effective to increase the mass (volume) of the mass member 102.

JP 2006-118660 A

  However, in the above-described conventional dynamic damper, since many parts such as an air bag and a horn switch are arranged around the boss portion, there is hardly enough space to increase the mass (volume) of the mass member. On the other hand, compared to the periphery of the boss portion, it is easy to secure a space on the inner surface side of the lower cover, but a pair of second side surfaces of the inner surface side portion (second mass body) of the lower cover of the mass member is provided. Since the two stopper walls are opposed to each other, the second stopper wall becomes an obstacle, and the mass (volume) of the second mass body cannot be increased along the inner surface of the lower cover. For this reason, it is difficult to increase the mass (volume) of the mass member corresponding to the peak frequency of vibration of the steering wheel, and there is a problem that the degree of freedom in designing the dynamic damper cannot be ensured.

  The present invention has been made to solve the above-described problems, and it is possible to increase the volume of the mass member corresponding to the peak frequency of the vibration of the steering wheel while preventing the generation of abnormal noise when traveling on rough roads. It aims at providing the dynamic damper which can ensure the freedom degree of design by doing.

Means for Solving the Problems and Effects of the Invention

  In order to achieve this object, a dynamic damper according to claim 1 is accommodated in a lower cover of a steering wheel, is disposed to face an inner surface of the lower cover, and is connected to a boss portion of the steering wheel. The mass member functioning as a body is connected by a vibration-proof base made of a rubber-like elastic material, so that idling and running vibration are attenuated.

  Since the center and both ends of the main body of the mass member are connected to the first connecting portion and the pair of second connecting portions of the bracket member by the first base and the pair of second bases of the vibration isolating base, When a large vibration is propagated from the attachment plate portion attached to the boss portion of the bracket member to the main body portion of the mass member, the main body portion of the mass member vibrates with the first base and the second base as the base points. To do. Therefore, both end portions of the main body portion are largely shaken because they are separated from the steering shaft as compared with the central portion of the main body portion. Accordingly, both end portions of the opposing surface of the main body portion are more likely to collide with the inner surface of the lower cover than the other portions, but the main body portion of the mass member has a lower opposing surface disposed opposite to the inner surface of the lower cover. Since it is formed in a convex curved shape on the inner surface side of the cover, both end portions of the opposing surface of the main body collide with the inner surface of the lower cover on the surface.

  Therefore, the impact force at the time of a collision can be made smaller than when both ends of the opposing surface of the main body collide with the inner surface of the lower cover at a point. Furthermore, since the first buffer portion of the buffer member is attached to both end portions of the opposing surface of the main body portion, the both end portions of the opposing surface of the main body portion and the inner side surface of the lower cover are connected via the first buffer portion. The impact force upon collision is absorbed by the first buffer portion. Therefore, even when a large vibration is input to the steering shaft when traveling on a rough road and the main body of the mass member collides with the inner surface of the lower cover, it is possible to prevent the occurrence of collision noise (abnormal noise). is there.

  The main body portion of the mass member is formed in a convex curved shape on the inner surface side of the lower cover, so that the opposing surface disposed opposite to the inner surface of the lower cover is compared to the case where the opposing surface is formed flat, The volume of the mass member can be increased to the inner surface side of the lower cover. Therefore, the volume of the mass member can be increased corresponding to the peak frequency of the vibration of the steering wheel, and the degree of freedom in designing the dynamic damper can be ensured.

  The bracket member has a pair of bent portions bent from both side edges of the mounting plate portion attached to the boss portion, and a pair of second connecting portions bent from both side edges of the pair of bent portions. There is an effect that the mechanical strength of the bracket member can be secured by the pair of bent portions.

  Furthermore, since a recessed part is recessedly provided in the bottom face which tolerance | permits with the opposing surface of a main-body part, and a pair of bending part is opposingly arranged by a pair of inner wall of the recessed part, a pair of ensuring the mechanical strength of a bracket member The bent portion can be accommodated in the recessed portion of the main body portion. Therefore, the volume of the main body can be increased along the inner surface of the lower cover without being obstructed by the pair of bent portions. Therefore, there is an effect that the volume of the mass member can be increased corresponding to the peak frequency of vibration of the steering wheel, and the design freedom of the dynamic damper can be ensured.

  According to the dynamic damper of the second aspect, the second buffer portion of the buffer member is attached to both end portions of the back surface on the boss portion side of the steering wheel that is opposite to the opposing surface of the main body portion. As a result, large vibrations are input to the steering shaft when traveling on rough roads, and both end portions of the back surface opposite to the opposing surface of the main body portion collide with parts such as an airbag and a horn switch arranged around the boss portion. Even if it is a case, the impact force at the time of a collision is absorbed by the 2nd buffer part. As a result, in addition to the effect of the first aspect, there is an effect that it is possible to prevent the occurrence of a collision sound (abnormal noise) when traveling on a rough road.

  According to the dynamic damper of the third aspect, since the central portion on the opposing surface of the main body portion is the portion protruding to the outermost side (lower cover side) of the mass member as compared with the both end portions, the steering wheel is turned. When a large vibration is input to the steering shaft, the central portion may easily collide with the inner side surface of the lower cover as compared to the opposite end portions of the opposing surface of the main body portion. Therefore, since the third buffer portion of the buffer member is attached to the central portion of the opposing surface of the main body portion, a large vibration is input to the steering shaft when traveling on a rough road, and the inner surface of the lower cover and the opposing surface of the main body portion are Even when the center portion collides, the impact force at the time of the collision is absorbed by the third buffer portion. Therefore, in addition to the effect of Claim 1 or 2, there is an effect that it is possible to prevent the occurrence of a collision sound (abnormal noise) when traveling on a rough road.

  According to the dynamic damper of the fourth aspect, the first buffer portion and the second buffer portion are made of a rubber-like elastic body, and the first buffer portion, the second buffer portion, and the second base are integrally formed. Therefore, when the second substrate is vulcanized, the first buffer portion and the second buffer portion can be simultaneously vulcanized at both end portions of the opposing surface of the main body, so that the buffer member is made of felt or the like. The operation of attaching the buffer member can be omitted. Therefore, in addition to the effect of the first or second aspect, there is an effect that the work process for manufacturing the dynamic damper can be reduced and the productivity of the dynamic damper can be improved.

  In addition, when the felt and the rubber-like elastic body are formed to have the same thickness, the rubber-like elastic body can absorb a larger impact force than the felt or the like. Therefore, when the 1st buffer part and the 2nd buffer part are constituted by a rubber elastic body, the thickness of the 1st buffer part and the 2nd buffer part can be made thin compared with the case where it comprises with felt. Therefore, the volume of the main body can be increased to the opposite surface side by the amount that the first buffer and the second buffer are made thinner. Therefore, in addition to the effect of the first or second aspect, the volume of the mass member can be increased in accordance with the peak frequency of the vibration of the steering wheel while preventing the generation of abnormal noise when traveling on rough roads. There is an effect that a degree of freedom can be secured.

It is a perspective view of the dynamic damper in one embodiment of the present invention. It is a perspective view of a dynamic damper. (A) is a plan view of the bracket member, (b) is a front view of the bracket member in the direction of arrow IIIb in FIG. 3 (a), and (c) is in the direction of arrow IIIc in FIG. 3 (a). It is a rear view of a bracket member, (d) is a side view of the bracket member in the arrow IIId direction view of FIG.3 (b). (A) is a top view of a mass member, (b) is a front view of the mass member in the arrow IVb direction view of Fig.4 (a). (A) is a top view of a dynamic damper, (b) is a front view of a dynamic damper, (c) is a rear view of a dynamic damper. 5A is a cross-sectional end view of the dynamic damper taken along line VIa-VIa in FIG. 5A, and FIG. 5B is a cross-sectional end view of the dynamic damper taken along line VIb-VIb in FIG. It is sectional drawing of the metal mold | die with which the bracket member and the mass member were assembled | attached. It is a front view of a steering wheel. It is a perspective view of the conventional dynamic damper.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of a dynamic damper 1 according to an embodiment of the present invention, illustrating a state viewed from the direction of the facing surface 21a. FIG. 2 is a perspective view of the dynamic damper 1, illustrating a state viewed from the bottom surface 21c direction.

  As shown in FIGS. 1 and 2, the dynamic damper 1 is housed in a lower cover 71 (see FIG. 8) of a steering wheel 70 (see FIG. 8), and a dynamic damper for suppressing vibration of the steering wheel 70. It is. The dynamic damper 1 includes a bracket member 10 attached to the lower cover 71 of the steering wheel 70, a mass member 20 functioning as a mass body, and connects the bracket member 10 and the mass member 20 together with a rubber-like elastic material. The anti-vibration base 30 and the buffer member 40 attached to the mass member 20 are provided.

  The configuration of the bracket member 10 will be described with reference to FIGS. 1, 2, and 3. 3 (a) is a plan view of the bracket member 10, FIG. 3 (b) is a front view of the bracket member 10 as viewed in the direction of arrow IIIb in FIG. 3 (a), and FIG. It is a rear view of the bracket member 10 in the arrow IIIc direction view of a), FIG.3 (d) is a side view of the bracket member 10 in the arrow IIId direction view of FIG.3 (b).

  As shown in FIGS. 1, 2, and 3, the bracket member 10 is formed by bending a plate-like member by pressing, punching, or the like of a metal material, and a boss portion 74 (see FIG. 8) of the steering wheel 70. ) Attached to the attachment plate portion 11, an extension portion 12 extending from the attachment plate portion 11 in the same plane as the attachment plate portion 11, and the lower side being bent from the extension portion 12 ( The first bent portion 13 extending in the rear side of FIG. 3A and the lower side of FIG. 3B, and the extending direction of the extending portion 12 while being bent from the first bent portion 13 ( The first connecting portion 14 extending in the lower side of FIG. 3A and the front side of FIG. 3B and the lower side of the extending portion 12 are bent and extended downward. A pair of second bent portions 15 and both end sides of the bracket member 10 while being bent from both end edges of the pair of second bent portions 15 (on the right side and FIG. 3A and FIG. 3C) Respectively on the left) and a second connecting portion 16 of the pair which extends is configured.

  The attachment plate 11, the extension 12, the first bent portion 13, and the first connecting portion 14 are centered in the longitudinal direction of the bracket member 10 (left and right direction in FIGS. 3A and 3B). A rectangular opening 10a is formed in a penetrating manner. Thereby, weight reduction of the bracket member 10 can be achieved.

  In the attachment plate portion 11, an arc-shaped notch 11c coinciding with the outer periphery of the cylindrical case that accommodates the steering shaft 72 is recessed on the boss portion 74 side (the upper side in FIG. 3A) of the steering wheel 70. . Thereby, interference with the steering shaft 72 and the attachment board part 11 when attaching the attachment board part 11 to the boss | hub part 74 can be prevented.

  A pin insertion hole 11b is formed through both sides of the notch 11c of the mounting plate portion 11, and a positioning pin (not shown) is inserted into the pin insertion hole 11b, so that the mold (see FIG. 8) is inserted. The bracket member 10 is positioned. An attachment hole 11a having an inner diameter that is slightly larger than the pin insertion hole 11b is formed on both sides of the pin insertion hole 11b. The bracket member 10 is attached to the boss portion 74 by screwing a bolt (not shown) inserted through the attachment hole 11 a into the boss portion 74.

  Since the opening part 10a is arrange | positioned in the center in the longitudinal direction (FIG. 3 (a) and FIG.3 (b) left-right direction) of the 1st bending part 13, the 1st bending part 13 is 2 sheets. It is formed by the plate-shaped member. Further, the two plate-like members constituting the first bent portion 13 are formed in the same shape, and the length in the longitudinal direction is shorter than the length in the longitudinal direction of the opening 10a.

  A first through hole 14b is formed through the center of the first connecting portion 14, and the inner diameter of the first through hole 14b is formed substantially the same as the pin insertion hole 11b. A rubber-like elastic body is vulcanized and bonded to the first through hole 14b, and a first penetration portion 33 (see FIG. 6) of the vibration-proof base 30 described later is formed by the vulcanized and bonded rubber-like elastic body. .

  The first connecting portion 14 is bent from both ends thereof and extends downward, and then extends to the second connecting portion 16 side (left and right sides in FIGS. 3A and 3B). The first protrusion 14a is provided. The 1st projection part 14a is formed in the same surface as the 2nd connection part 16 of the bracket member 10 mentioned later.

  A positioning recess 10 c cut out from the connecting portion toward the center of the bracket member 10 is formed through the connecting portion between the attachment plate portion 11 and the extending portion 12. A protrusion (not shown) formed on a mold 60 (see FIG. 8) described later is fitted into the positioning recess 10c. Thereby, it is possible to prevent the bracket member 10 from being displaced with respect to the mold 60 (see FIG. 8) when the vibration-proof base 30 (see FIGS. 1 and 2) is vulcanized.

  As for the 2nd connection part 16, the 2nd protrusion part 16a of the side view L-shape is formed in the part by the side of the 2nd bending part 15 (FIG.3 (d) paper surface back side). The second protruding portion 16a extends while being bent downward (FIG. 3 (a) on the back side of the paper surface and FIG. 3 (d) below) from the portion disposed on the second bent portion 15 side of the second connecting portion 16. The extension portion 12 is further bent while being bent in the extending direction of the extending portion 12 (downward in FIG. 3 (b) and leftward in FIG. 3 (d)). Thereby, the tip end portion of the second protrusion 16 a is disposed at a position lower than the second connecting portion 16. Further, the second connecting portion 16 has a vertical width (width in a direction orthogonal to the longitudinal direction of the bracket member 10, length in the vertical direction in FIG. 3A) on both ends across the second protrusion 16 a. 2 formed longer than the vertical width on the center side with the protrusions 16a interposed therebetween. A second through-hole 16b is formed through a portion of the second connecting portion 16 where the longitudinal width is long, and a rubber-like elastic body is vulcanized and bonded to the second through-hole 16b. A second penetrating portion 37 (see FIG. 6) of the vibration-proof base 30 to be described later is formed by the elastic elastic body.

  An opening 10 b is formed through the bracket member 10. The opening portion 10 b is configured as an opening surrounded by the extending portion 12, the first bent portion 13, the first connecting portion 14, the second bent portion 15, and the second connecting portion 16. By forming the opening 10b, the bracket member 10 can be reduced in weight.

  The pair of second bent portions 15 are bent from the extending portion 12, and the pair of second connecting portions 16 are bent from the pair of second bent portions 15. Thereby, the mechanical strength of the bracket member 10 can be ensured. Moreover, since a pair of 1st projection part 14a is bent from the both ends of the 1st connection part 14, and the front-end | tip part of a pair of projection part 14a is bent, a pair of 1st projection part 14a of the bracket member 10 is carried out. Mechanical strength can be secured. Furthermore, crushing ribs 15a and 15b are formed on the ridgeline between the second bent portion 15 and the extending portion 12 and the ridgeline between the second bent portion 15 and the second connecting portion 16, thereby improving the mechanical strength of the bracket member 10. It can be further improved. Thereby, since the plate | board thickness of the bracket member 10 can be thinned, the weight reduction of the bracket member 10 can be achieved. Even when the volume of the mass member 20 is increased corresponding to the peak frequency of vibration of the steering wheel 70, the weight increase of the dynamic damper 1 can be suppressed by the weight reduction of the bracket member 10. It is possible to correspond to the peak frequency of vibration of the steering wheel 70 without incurring the weight of the damper 1.

  The configuration of the mass member 20 will be described with reference to FIGS. 1, 2, and 4. 4A is a plan view of the mass member 20, and FIG. 4B is a rear view of the mass member 20 as viewed in the IVb direction. The mass member 20 is made of a metal material such as cast iron, and is formed in an oblong lump shape in a horizontal direction in plan view, and the opposing surface 21a is opposed to the inner surface of the lower cover 71 (see FIG. 8). The pair of first projecting portions 22 projecting from both end portions of the bottom surface 21c intersecting the facing surface 21a of the main body portion 21 and the center side of the pair of first projecting portions and opposite to the facing surface 21a of the main body portion. A pair of second projecting portions 23 projecting from the back surface 21b and a pair of first projecting portions 22 project from both end portions of the bottom surface 21c of the main body portion, thereby being recessed at the center of the bottom surface 21c of the main body portion 21. It is configured to include a recessed portion 24 and a second recessed portion 25 that is continuous with the first recessed portion 24 and is recessed on the bottom surface 21 c and the back surface 21 b of the main body portion 21. The main body 21 has a plurality of protrusions (the first protrusion 22 and the second protrusion 23) to increase the volume.

  As shown in FIG. 4, the main body portion 21 is formed in an oval shape in the lateral direction in plan view, so that the distance between the opposing surface 21 a and the back surface 21 b facing each other is the largest in the center in the longitudinal direction of the mass member 20. Long and shortest at both ends. Since the inner surface of the lower cover 71 (see FIG. 8) is formed in a curved shape that is convex upward, the facing surface 21a of the main body 21 is formed in a shape corresponding to the curved shape of the inner surface of the lower cover 71. Therefore, since the main body can make maximum use of the space on the inner surface of the lower cover 71, the volume can be increased to the opposing surface 21a side.

  As shown in FIG. 4, the first recessed portion 24 is a downwardly opened recess disposed on the facing surface 21 a side (the lower side in FIG. 4B) of the main body portion 21, and a central recessed portion is formed at the center thereof. The portion 24a is recessed. Thereby, the bottom surface 21c of the main body 21 is formed in a stepped shape that rises from the first projecting portion 22 toward the central recessed portion 24a.

  As shown in FIG. 4, the second recessed portion 25 includes a pair of lower walls 25 a that are inner walls extending in the vertical direction, and an upper side of the pair of lower walls 25 a toward the center in the longitudinal direction of the mass member 20. A pair of inner walls 25b, which are inner walls extended, a pair of upper walls 25c extending from the central side of the pair of inner walls 25b to the upper surface 21d of the main body 21, and a pair of lower walls 25a; It is formed by a pair of inner side walls 25b and a side wall 25d that is an inner wall including the side of the pair of upper walls 25c on the facing surface 21a side, and is disposed on the back surface 21b side (the upper side in FIG. 4 (b)) of the main body 21. Is done.

  The second recessed portion 25 is open on the back surface 21b side and the upper surface 21d side (the front side in FIG. 4A), and the recessed depth of the second recessed portion 25 (from the bottom surface 21c of the first protruding portion 22). The separation distance between the pair of inner side walls 25b is deeper than the depth of the first recessed portion 24. A part of the bracket member 10 described later is accommodated in the first recessed portion 24 and the second recessed portion 25.

  The configuration of the dynamic damper 1 will be described with reference to FIGS. 5A is a plan view of the dynamic damper 1, FIG. 5B is a front view of the dynamic damper 1 as viewed in the direction Vb of FIG. 5A, and FIG. 2) is a rear view of the dynamic damper 1 when viewed in the Vc direction. 6A is a sectional end view of the dynamic damper 1 taken along the line VIa-VIa in FIG. 5A, and FIG. 6B is a sectional end face of the dynamic damper 1 taken along the line VIb-VIb in FIG. FIG. FIG. 7 is a cross-sectional view of the mold 60 showing a state in which the bracket member 10 and the mass member 20 are assembled. FIG. 8 is a front view of the steering wheel 70, showing a state in which an upper cover (not shown) is removed, and shows a state in which the dynamic damper 1 is accommodated in the lower cover 71 of the steering wheel 70. Yes.

  As shown in FIGS. 5 and 6, the vibration isolating base 30 is a rubber-like elastic body that couples the bracket member 10 and the mass member 20, and the vibration isolating base 30 and the buffer member 40 are integrally vulcanized and molded. Is done. The anti-vibration base 30 includes a first base 31 that connects the bottom surface 21 c that forms the central recess 24 a of the mass member 20 and the first connection portion 14 of the bracket member 10, and a first connection portion that is connected to the first base 31. A first overhanging portion 32 which is bonded to the upper surface of the first through-hole 14, a first through-hole portion 33 which is connected to the inner periphery of the first through hole 14b and is connected to the first overhanging portion 32; The second overhanging portion 34 that is connected to the first through-hole portion 33 and that is bonded to the lower surface of the first connecting portion 14, the bottom surface 21 c of the first protruding portion 22 of the mass member 20, and the second connection of the bracket member 10. A second base 35 that connects the parts 16, a first overhanging part 36 that is connected to the second base 35 and is bonded to the upper surface of the second connecting part 16, and a first overhanging part 36. A second through-hole 37 that is bonded to the inner periphery of the second through-hole 16b, and a lower part of the second connecting portion 16 that is connected to the second through-hole 37. Constructed a second projecting portion 38 which is vulcanization bonded to.

  As shown in FIG. 6, the first base 31 is formed in a prismatic shape, and is a plate-like rubber connection that is connected from the upper end of the first base 31 and is vulcanized and bonded to the bottom surface 21 c of the first protrusion 22. A portion 31a is provided. The upper end of the first base 31 is connected to a third buffer portion 43 described later by the rubber connecting portion 31a. As shown in FIG. 5, the first base 31 is formed such that the length of the mass member 20 in the longitudinal direction is longer than that of the second base 35, and the length of the mass member 20 in the short direction is substantially the same as the second base 35. Formed. Therefore, the spring constant of the first base 31 can be set larger than the spring constant of the second base 35.

  The first overhanging portion 32 and the second overhanging portion 34 are longer than the first base 31 in the longitudinal direction (FIG. 5B, left-right direction) and in the short side direction (FIG. 6A, left-right direction). It is formed in a rectangular plate shape, and the thickness of the first overhanging portion 32 (the length in the vertical direction in FIG. 6A) is set to be smaller than the thickness of the bracket member 10 (first connecting portion 14). . The lower end of the first base 31 is connected to the first connecting portion 14 of the bracket member 10 by the first overhang portion 32.

  The first penetration part 33 is formed in a cylindrical shape whose outer diameter is shorter than the length of the first base 31 in the short direction, and is formed by vulcanizing and bonding a rubber-like elastic body to the first through hole 14b. Is done. The first overhanging portion 33 connects the first overhanging portion 32 and the second overhanging portion 34, and the first overhanging portion 32 connects the lower end of the first base 31 to the first connecting portion 14 of the bracket member 10. Therefore, the first base 31 is connected to the bottom surface 21 c of the first projecting portion 22 and the upper and lower surfaces of the first connecting portion 14. Moreover, since the external shape of the 1st overhang | projection part 32 and the 2nd overhang | projection part 34 is formed larger than the external shape of the 1st penetration part 33, the 1st overhang | projection part 32 and the 2nd overhang | projection part 34 are used as a retaining. Function. Therefore, it is possible to reliably suppress the first base 31 from falling off the bracket member 10. Thereby, it is also possible to eliminate the need for an adhesive between the first connecting portion 14 and the second connecting portion 16 and the rubber-like elastic body.

  The pair of second base bodies 35 are formed in the same shape, and are configured similarly to the first base body 31 except that the length of the mass member 20 in the longitudinal direction is shorter than that of the first base body 31. Therefore, explanation is omitted. The first projecting portion 36 corresponds to the first projecting portion 32, the second projecting portion 37 corresponds to the first projecting portion 33, and the second projecting portion 38 corresponds to the second projecting portion 34, respectively.

  As shown in FIG. 5, the buffer member 40 is integrally vulcanized and bonded to the second base 35 at both ends of the opposing surface 21 a (the lower surface in FIG. 5A) of the mass member 20 (main body portion 21). A pair of first buffer parts 41 and a second buffer which is vulcanized and bonded integrally with the second base 35 to both ends of the back surface 21b (the upper surface in FIG. 5A) of the mass member 20 (main body part 21). Portion 42 and a third buffer portion 43 that is integrally vulcanized and bonded to the first base 31 at the center of the opposing surface 21a of the mass member 20 (the lower surface in FIG. 5A). .

  As shown in FIG. 6, the first buffer portion 41, the second buffer portion 42, and the third buffer portion 43 are made of a rubber-like elastic body, and the first buffer portion 41 and the second buffer portion 42 are the second base body 35. Are integrally formed through the rubber connecting portion 35a. The third buffer 43 is configured separately from the first buffer 41 and the second buffer.

  When the 1st buffer part 41, the 2nd buffer part 42, and the 3rd buffer part 43 are comprised with felt etc., the operation | work which sticks felt etc. to the mass member 20 is needed. On the other hand, in the present invention, the first buffer portion 41 and the second buffer portion 42 are made of a rubber-like elastic body and vulcanized integrally with the second base body 35, and the third buffer portion 43 is connected to the first base body 31. It is vulcanized together. Therefore, the 1st buffer part 41 and the 3rd buffer part 43 are stuck on the opposing surface 21a of mass member 20 (main part 21), and the 2nd buffer part 42 is stuck on back 21b of mass member 20 (main part 21), respectively. Therefore, the work process for manufacturing the dynamic damper 1 can be reduced, and the productivity of the dynamic damper 1 can be improved.

  Further, when the felt and the rubber-like elastic body are formed to have the same thickness, the rubber-like elastic body can absorb a larger impact force than the felt or the like. Therefore, when the 1st buffer part 41, the 2nd buffer part 42, and the 3rd buffer part are constituted by rubber elastic bodies, compared with the case where it comprises with felt, the 1st buffer part 41, the 2nd buffer part 42, and the 2nd buffer part. 3 The thickness of the buffer portion 42 can be reduced. Therefore, the volume of the main body 21 can be increased on the facing surface 21a and the back surface 21b side by the thickness of the first buffer 41, the second buffer 42, and the third buffer. Therefore, the volume of the mass member 20 can be easily increased in correspondence with the peak frequency of vibration of the steering wheel 70, so that the degree of freedom in design can be ensured. Moreover, since the impact force is absorbed by the first buffer portion 41, the second buffer portion 42, and the third buffer portion, it is possible to prevent the generation of abnormal noise when traveling on a rough road.

  Since the 1st buffer part 41 and the 2nd buffer part 42 are integrally molded via the rubber | gum connection part 35a, the whole both ends of the main-body part 21 can be laid with a rubber-like elastic body. Therefore, even when both end portions of the main body portion 21 are greatly shaken compared to the central portion of the main body portion 21 and collide with the inner surface of the lower cover 71 or the boss portion 74, the impact force at the time of the collision is the first buffer. Since it is absorbed by the part 41 and the second buffer part 42, the generation of abnormal noise can be prevented.

  Moreover, as shown in FIG.2 and FIG.5 (b), since the 1st connection part 14 of the bracket member 10 is arrange | positioned with respect to the 2nd connection part 16, near the opposing surface 21a side of the mass member 20. FIG. The first base 31 is located away from the straight line passing through the second base 35 toward the facing surface 21 a of the mass member 20. Further, since the first connecting portion 14 of the bracket member 10 is connected to the central recessed portion 24 a of the mass member 20, the first base 31 is separated from the straight line passing through the second base 35 toward the upper surface 21 d of the mass member 20. To position. As a result, it is possible to obtain an effective damping effect against the vibration in the longitudinal direction and the short direction of the mass member 20 and the vibration in the torsional direction, and to suppress the vibration of the steering wheel 70 (see FIG. 8). Can be obtained in a wide frequency band.

  Next, with reference to FIG. 7, the manufacturing method of the dynamic damper 1 comprised as mentioned above is demonstrated. In FIG. 7, the second connecting portion 16 and the mass member 20 (main body portion 21) connected by the second base 35 will be illustrated and described. In order to mold the vibration-proof base 30, as shown in FIG. 7, the mass member 20 is fixed to the first mold, and the bottom surface 21c of the mass member 20 and the one surface side of the first connecting portion 16 are spaced apart from each other by a predetermined distance. The bracket member 10 is attached to the first mold 61 using the first protrusion 14a, the second protrusion 16a, and the pin insertion hole 11b (see FIG. 3A) of the bracket member 10 so as to face each other. Fix it.

  Next, the second mold 62 and the third mold 63 are used to close the mold in the left-right direction in FIG. 7 (the arrow Vb direction or the arrow Vc direction in FIG. 5A) to form the cavity 66. Next, a rubber-like elastic body is injected into the second through hole 16 b and the cavity 66 from the supply path 64 of the mold 60 through the gate 65. Accordingly, the first buffer portion 41, the second buffer portion 42, the second rubber connecting portion 35a, the second base body 35, the first overhang portion 36, the second penetration portion 37, and the second overhang portion 38 (FIG. 6). (B) is formed. The first buffer 41 and the second buffer 42 and the mass member 20 are vulcanized and bonded. After the rubber-like elastic body is cured, the mold is released, and the rubber-like elastic body is cut in the vicinity of the gate 65 located on the other surface side of the bracket member 10, so that the bracket member 10 and the mass member 20 are the vibration-isolating base 30. A connected dynamic damper 1 is obtained.

  As described above, the cut mark for cutting the cured rubber-like elastic body is formed on the other surface side of the bracket member 10. The load of the mass member 20 is a load of the vibration isolation base 30 that connects the mass member 20 and one surface side of the bracket member 10 (the surface facing the mass member 20), but is formed on the other surface side of the bracket member 10. Since it does not become a load of the cut trace that has been made, the cut trace is unlikely to be the starting point of the crack of the vibration-proof substrate 30, and even if a crack occurs in the vibration-proof substrate 30 starting from the cut mark, it is difficult to grow the crack. Therefore, the durability of the dynamic damper 1 can be improved. In addition, since the cut trace is unlikely to become the starting point of the crack of the vibration-proof substrate 30, a finishing process that prevents the cut trace from being left can be eliminated, and productivity can be improved.

  In addition, an adhesive that bonds the first buffer portion 41 and the second buffer portion 42 to the mass member 20 is necessary, but the first overhang portion 36 and the second overhang portion 38 sandwiching the second connecting portion 16. (Refer to FIG. 6 (b)), so that the second connecting portion 16 and the rubber-like elastic body are vulcanized and bonded, or the second connecting portion 16 and the rubber-like elastic body are vulcanized and bonded. Even if the application amount of the adhesive is small, it is possible to connect the second connecting portion 16 and the vibration isolation base 30. Thereby, the application quantity of an adhesive agent can be reduced.

  Further, a parting line is set on the vibration-proof base 30 by closing the mold in the left-right direction in FIG. 7 (the direction of the arrow Vb or the direction of the arrow Vc in FIG. 5) by the second mold 62 and the third mold 63. The mold structure can be simplified.

  As shown in FIG. 8, the main body portion 21 of the mass member 20 is opposed to the inner surface of the lower cover 71, because the opposing surface 21 a is formed in a convex curved shape on the inner surface side of the lower cover 71. The volume of the mass member 20 can be increased toward the inner side surface of the lower cover 71 as compared with the case where the surface is formed flat. Therefore, the volume of the mass member 20 can be increased corresponding to the peak frequency of vibration of the steering wheel 70, and the degree of freedom in design can be secured.

  Here, as shown in FIG. 5 (c), the pair of inner side walls 25b of the second recessed portion 25 and the extending portion 12 are arranged to face each other in the vertical direction (FIG. 5 (c) vertical direction). The side wall 25d of the portion 25 and the first bent portion 13 are arranged to face each other in a short direction (FIG. 5 (c) perpendicular to the paper surface) perpendicular to the longitudinal direction of the mass member 20, and a pair of second bent portions 15 are provided. The pair of lower walls 25a of the second recessed portion and the mass member are arranged to face each other in the longitudinal direction (the left-right direction in FIG. 5C). Therefore, the extended portion 12 of the bracket member 10, the first bent portion 13, and the pair of second bent portions 15 are accommodated in the second recessed portion 25.

  As shown in FIG. 5, the first recessed portion 24 and the first connecting portion 14 are disposed to face each other in the vertical direction of the mass member 20 (the vertical direction in FIG. 5B), and the first recessed portion 24 and the pair of first portions The protruding portion 14 a is disposed to face the mass member 20 in the longitudinal direction. Therefore, the first recessed portion 24 accommodates the first connecting portion 14 of the bracket member 10 and the pair of first projecting portions 14a. Therefore, a plurality of bent portions (extension portions 12, a pair of second bent portions 15 and a pair of first projection portions 14a) that secure the mechanical strength of the bracket member 10 are recessed in the mass member 20. The first concave portion 24 and the second concave portion 25 are accommodated. Therefore, the mass (volume) of the mass member 20 can be increased without a plurality of bent portions becoming an obstacle.

  That is, as shown in FIG. 8, the dynamic damper 1 is accommodated in the lower cover 71 in a state where the opposing surface 21 a of the main body 21 of the mass member 20 is disposed to face the inner surface of the lower cover 71 of the steering wheel 70. . The bracket member 10 is connected to the boss portion 74 of the steering wheel 70, and the bracket member 10 and the mass member 20 functioning as a mass body are connected by a vibration-proof base 30 made of a rubber-like elastic material. , Vibration during idling and running is attenuated.

  Inside the steering wheel 70, a large number of parts (spokes 73, etc.) such as an air bag and a horn switch (not shown) are arranged around the boss 74, so that the mass (volume) of the mass member 20 is increased. There is little space to make it happen. On the other hand, compared to the periphery of the boss portion 74, the inner side surface (upper side in FIG. 8) of the lower cover 71 can easily secure a space, but the mechanical strength of the bracket member is ensured on both side surfaces of the conventional mass member. Since the pair of second stopper walls, which are parts, are arranged to face each other, the second stopper wall becomes an obstacle, and the mass (volume) of the mass member cannot be increased along the inner surface of the lower cover.

  On the other hand, in the dynamic damper 1 of the present invention, the portions (the extended portion 12, the pair of second bent portions 15 and the pair of first protrusions 14a) that ensure the mechanical strength of the bracket member 10 are the mass members 20. Since the first concave portion 24 and the second concave portion 25 are accommodated in the first concave portion 24 and the second concave portion 25, the volume of the bracket member 10 can be increased without obstructing the portion that secures the mechanical strength of the bracket member 10. The volume of the mass member 20 can be increased corresponding to the peak frequency of vibration of the steering wheel 70, and the degree of freedom in design can be ensured.

  As shown in FIGS. 5 and 8, the center and both ends of the main body 21 of the mass member 20 are connected to the first connecting portion 14 of the bracket member 10 by the first base 31 and the pair of second bases 35 of the vibration-proof base 30. Since the large vibration is input to the steering shaft 72 and is attached to the boss 74 of the bracket member 10, the large connecting portion 11 is connected to the main body 21 of the mass member 20. When the vibration is propagated, the main body 21 of the mass member 20 vibrates with the first base 31 and the pair of second bases 35 as base points.

  Therefore, both end portions of the main body portion 21 are largely separated because they are separated from the steering shaft 72 as compared with the central portion of the main body portion 21. Therefore, both end portions of the facing surface 21a of the main body 21 are likely to collide with the inner surface of the lower cover 71 as compared with the other portions, but the main body portion 21 of the mass member 20 is disposed to face the inner surface of the lower cover 71. Since the opposed surface 21a is formed in a curved shape that is convex on the inner surface side (upper side in FIG. 8) of the lower cover 71, both end portions of the opposed surface 21a of the main body 21 collide with the inner surface of the lower cover 71. To do.

  Since both end portions of the opposing surface 21a of the main body 21 collide with the inner side surface of the lower cover 71 at the surface, both ends of the opposing surface 21a of the main body portion 21 and the inner side surface of the lower cover 71 collide with each other compared with points. Can reduce the impact force. Furthermore, since the first buffer portion 41 of the buffer member 40 is vulcanized and bonded to both end portions of the opposing surface 21a of the main body portion 21, both end portions of the opposing surface 21a of the main body portion 21 are interposed via the first buffer portion 41. And the inner surface of the lower cover 71 collide with each other. Therefore, the impact force when the both end portions of the facing surface 21 a of the main body portion 21 collide with the inner surface of the lower cover 71 is absorbed by the first buffer portion 41. Therefore, even when a large vibration is input to the steering shaft 72 when traveling on a rough road and the opposing surface 21a of the main body 21 collides with the inner surface of the lower cover 71, the generation of a collision sound (abnormal noise) is prevented. it can.

  Second buffer portions 42 are vulcanized and bonded to both end portions of the back surface 21b of the main body portion 21. As a result, large vibrations are input to the steering shaft 72 when traveling on a rough road, and when both end portions of the back surface 21b of the main body 21 collide with parts such as an airbag and a horn switch arranged around the boss 74. Even if it exists, the impact force at the time of a collision is absorbed by the 2nd buffer part 42. FIG. As a result, it is possible to prevent the occurrence of collision noise (abnormal noise) when traveling on a rough road.

  The main body portion 21 of the mass member 20 has a facing surface 21 a that is opposed to the inner side surface of the lower cover 71 and is formed in a curved shape that is convex on the inner side surface (upper side in FIG. 8) of the lower cover 71. The central portion of the facing surface 21a is a portion protruding to the outermost side (lower cover side) of the mass member as compared with the both end portions. Therefore, when a large vibration is input to the steering shaft 72 while the steering wheel 70 is turned, the center portion is likely to collide with the inner side surface of the lower cover 71 as compared with both end portions of the opposing surface 21 a of the main body portion 21. There is a case. Even in this case, since the third buffer portion 43 is stuck to the central portion of the opposing surface 21a of the main body portion 21, a large vibration is input to the steering shaft 72 when traveling on a rough road, and the inner surface of the lower cover 71 Even when the center part of the opposing surface 21 a of the main body 21 collides, the impact force at the time of the collision is absorbed by the third buffer part 43. Therefore, it is possible to prevent the occurrence of collision noise (abnormal noise) when traveling on a rough road.

  As described above, the present invention has been described based on the embodiments, but the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed.

  For example, in the above-described embodiment, the case where the third buffer unit 43 is configured separately from the first buffer unit 41 and the second buffer unit 42 has been described, but is not necessarily limited thereto. The three buffer portions 43 may be formed integrally with the first buffer portion 41 and the second buffer portion 42. In this case, if the entire opposing surface 21a of the main body portion 21 is laid with a rubber-like elastic body, the opposing surface 21a of the main body portion 21 and the inner surface of the lower cover 71 collide via the rubber-like elastic body. It is possible to reliably suppress the generation of abnormal noise at the time of collision.

  In the above embodiment, the case where the mass member 20 includes the first protrusion 22 and the second protrusion 23 has been described. However, the present invention is not necessarily limited thereto, and the second protrusion 23 may not be provided. . In this case, by extending both end portions of the main body 21 of the mass member 20 along the inner surface of the lower cover 71, the space on the inner surface side of the lower cover 71 can be effectively used to make the second protrusion 23. While a considerable volume can be secured, a space can be secured on the mass member 20 and the boss portion 74 side. Therefore, when the dynamic damper 1 is attached to the lower cover 71, interference between the mass member 20 and the components around the boss portion 74 occurs. Can be suppressed. Therefore, the installation work of the dynamic damper 1 can be performed efficiently.

  In the said embodiment, although the case where the extension part 12 was extended in the same plane as the attachment board part 11 from the attachment board part 11 was demonstrated, it is not necessarily limited to this, and the extension part 12 May be formed in an L shape in a side view. In this case, the mechanical strength of the bracket member 10 can be further improved.

  In the above embodiment, the case where the first bent portion 13 and the second bent portion 15 are extended while being bent from the extended portion 12 has been described, but the present invention is not necessarily limited to this. The first bent portion 13 and the second bent portion 15 may be extended while being bent from the landing plate portion 11. In this case, the mass member 20 can be disposed closer to the steering shaft 52 than when the first bent portion 13 and the second bent portion 15 are extended from the extended portion 12.

  In the said embodiment, although the case where the length of the 2nd bending part 15 was set short compared with the length of the 1st bending part 13 of the bracket member 10, it is not necessarily restricted to this, It is also possible to set the length of the first bent portion 13 to be longer than the length of the second bent portion 15 according to the peak frequency of vibration of the steering wheel 70 or the like. In this case, the shape of the mass member 20 is appropriately set according to the shape of the bracket member 10.

  In the above-described embodiment, the case where the facing surface 21a of the mass member 20 is configured to protrude convexly is described. However, the shape is not limited to this shape, and may be a substantially rectangular parallelepiped shape. .

  In the above embodiment, the case where the mass member 20 includes the first projecting portion 22 and the second projecting portion 23 has been described. However, the mass of the mass member 20 is reduced in relation to the peak frequency of vibration of the steering wheel 70. If necessary, the first protrusion 22 and the second protrusion 23 may not be provided.

  Although the case where the dynamic damper 1 is attached to the boss portion 74 in the lower cover 71 has been described in the above embodiment, the dynamic damper 1 may be attached to the spoke 73.

  Further, the buffer member 40 may be attached to the facing surface where the second bent portion 15 of the bracket member 10 faces the lower wall 23a of the mass member 20. The distance between the second bent portion 15 and the lower wall 51a is set longer than the distance between the facing surface 21a of the main body 21 and the inner surface of the lower cover 71. If the inner surface of the cover 71 collides, the second bent portion 15 of the bracket member 10 and the lower wall 23a of the mass member 20 are unlikely to collide, but depending on the position of the steering wheel 70, the bracket member 10 The second bent portion 15 and the lower wall 23a of the mass member 20 may collide with each other. Even in this case, if the buffer member 40 is attached to the facing surface of the second bent portion 15, the impact force at the time of the collision can be absorbed, and the generation of abnormal noise can be suppressed.

DESCRIPTION OF SYMBOLS 1 Dynamic damper 10 Bracket member 11 Mounting plate part 12 Extension part (a part of mounting plate part)
14 1st connection part 15 2nd bending part (folding part)
16 2nd connection part 20 Mass member 21a Opposing surface 21b Back surface 21c Bottom surface 25 2nd recessed part (concave part)
25a Lower wall (inner wall)
30 Anti-vibration base 31 First base 35 Second base 40 Buffer member 41 First buffer 42 Second buffer 43 Third buffer 70 Steering wheel

Claims (4)

A bracket member connected to the boss portion of the steering wheel; a mass member that functions as a mass; and a vibration-proof base that connects the bracket member and the mass member and is made of a rubber-like elastic material. In the dynamic damper that is accommodated in the lower cover and is disposed opposite to the inner surface of the lower cover,
Comprising a buffer member attached to the mass member;
The mass member is
A main body portion formed in a curved shape in which a facing surface facing the inner surface of the lower cover is convex on the inner surface side of the lower cover;
A recessed portion having a pair of inner walls that are recessed on the bottom surface that intersects the facing surface of the main body portion and that faces each other;
The bracket member is
An attachment plate portion attached to the boss portion;
A first connecting portion extending from the attachment plate portion to the opposing surface side of the main body portion;
A pair of bent portions that are respectively bent from both edge portions of the mounting plate portion and extended to the bottom surface side of the main body portion and opposed to the pair of inner walls of the recessed portion;
A pair of second connecting portions that are respectively bent from both end edges of the pair of bent portions and extended to both end sides of the main body portion and disposed opposite to both end portions of the bottom surface of the main body portion;
With
The vibration-proof substrate is
A first base for connecting the central portion of the bottom surface of the main body and the first connecting portion of the bracket member;
A pair of second bases for connecting both end portions of the bottom surface of the main body and a pair of second connecting portions of the bracket member;
The said damper member is provided with the 1st buffer part stuck on the both ends in the opposing surface of the said main-body part, The dynamic damper characterized by the above-mentioned.   The said buffer member is provided on the opposite side to the opposing surface of the said main-body part, Comprising: The 2nd buffer part stuck on the both ends in the back surface by the side of the boss | hub part of the said steering wheel is characterized by the above-mentioned. Dynamic damper.   3. The dynamic damper according to claim 1, wherein the buffer member includes a third buffer portion that is attached to a central portion of the opposing surface of the main body portion with respect to both end portions of the mass member.   2. The first buffer portion and the second buffer portion are made of a rubber-like elastic body, and the first buffer portion, the second buffer portion, and the second base are integrally formed. Or the dynamic damper of 2.

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