JP5061067B2 - Dynamic damper for vehicles - Google Patents

Description

  The present invention relates to a dynamic damper for a vehicle, and more particularly to a dynamic damper that is suitable for vibration isolation of a subframe or a differential device.

A dynamic damper is a vibration isolator that is attached to a vibrating body (main vibration system) as a sub-vibration system and tunes the natural frequency to the natural frequency (resonant frequency) of the vibrating body to dampen the vibrating body. is there.
In vehicles, various parts resonate with external vibration input and become vibration and noise generating parts. Therefore, it is widely practiced to attach such dynamic dampers to the vibrating parts to prevent vibrations. ing.

For example, Patent Document 1 below discloses that a dynamic damper is attached to a front subframe and the subframe is vibrated.
Further, Patent Document 2 below discloses that a dynamic damper is attached to a transmission to prevent vibration.
Further, Patent Documents 3 and 4 disclose that a dynamic damper is attached to a differential device of a vehicle to dampen the differential device.

  Patent Document 4 points out that, in a differential device serving as a transmission unit for driving force from a propeller shaft to a drive shaft, the differential device vibrates when the transmitted driving force changes abruptly. In order to prevent this, it is disclosed that a dynamic damper is attached to a differential carrier (a differential carrier) in a differential device.

Conventionally, a dynamic damper as shown in FIG. 7 is known as a dynamic damper that is attached to a sub-frame to dampen it.
In the figure, reference numeral 200 denotes a dynamic damper, which includes a metal rigid mounting member 202, a metal rigid holding member 206, a metal damper mass 204, and a rubber elastic body 208.

The attachment member 202 includes a pair of leg portions 210 that stand from the attachment surface, and a connecting portion 212 that connects ends of the leg portions 210 opposite to the attachment surfaces.
An attachment portion 222 is provided at the lower end of the pair of leg portions 210 in the drawing, and the attachment portions 222 are attached and fixed to the subframe.
The mounting member 202 has a gate shape as a whole, and the holding member 206, the damper mass 204, and the rubber elastic body 208 are disposed in a space formed inside thereof.

The holding member 206 is a member for holding the damper mass 204 and has a U-shape. The damper mass 204 is fastened to the holding member 206 with the fastening bolts 220 and moves together with the holding member 206. Is retained.
The rubber elastic body 208 is connected to the holding member 206 and the pair of leg portions 210 of the attachment member 202.
Here, the rubber elastic body 208 is integrally vulcanized and bonded to the mounting member 202 and the holding member 206.

  These rubber elastic bodies 208 connect the vertical inner surface 214 on the void side of the leg 210 and the vertical opposing surface 216 of the holding member 206 facing the vertical inner surface 214 in the left-right direction in the figure. The rubber elastic body 208 as a whole forms a rubber arm portion 218 in the left-right direction in the drawing.

The main vibration direction of the subframe is the vehicle vertical direction, and the dynamic damper 200 is attached to the subframe with the vertical direction in the figure facing the vehicle vertical direction.
In this case, when the sub-frame vibrates in the vertical direction, which is the main vibration direction, the rubber elastic body 208 is entirely shear-elastically deformed in the vertical direction, and based on the large vertical elastic shear deformation, Effectively absorbs vertical vibrations and acts to prevent vibrations.

  The conventional dynamic damper 200 shown in FIG. 7 is attached to the subframe with the vertical direction in the figure facing the vehicle vertical direction, the horizontal direction in the figure facing the vehicle front-rear direction, and the direction perpendicular to the paper surface facing the vehicle left-right direction. Therefore, the rubber elastic body 208 is compressed (and pulled) with respect to the vibration in the front-rear direction.

  However, a large mounting space in the front-rear direction of such a dynamic damper cannot be secured in the subframe in the layout, and it may be necessary to arrange the left-right direction in FIG. 7 toward the left-right direction of the vehicle. If the dimensions need to be larger, the subframe will vibrate in the vertical direction as the vehicle travels in this case, and it will also vibrate in the front-rear direction due to the impact in the front-rear direction caused by acceleration, deceleration, and bumping of the vehicle. For this reason, the dynamic damper cannot exhibit sufficient anti-vibration performance with respect to the vertical direction, which is the main vibration direction, by such a combined input before and after such vertical movement. That is, the vibration proof performance as a dynamic damper is lowered.

  When this dynamic damper is used by being attached to a subframe so that the gate-shaped mounting member faces the left-right direction of the vehicle, the damper mass 204 vibrates not only in the vertical direction but also in the front-rear direction. As a result, the vibration amplitude in the vertical direction of the damper mass 204 becomes small, resulting in insufficient energy absorption, and sufficient vibration isolation performance cannot be exhibited. . That is, the effectiveness as a dynamic damper is weakened.

The natural frequency in the dynamic damper is given by the following formula (1).
fn = 1 / 2π · √K / M (1)
Here, K represents the spring constant of the rubber elastic body 208, and M represents the mass of the damper mass.

In the case of the dynamic damper 200 shown in FIG. 7, the rubber elastic body 208 is substantially the same in both the vertical direction and the front-rear direction when mounted in the vehicle lateral direction as described above. Shear elastic deformation.
Accordingly, the elastic elastic body 208 has the same static spring constant and dynamic spring constant both in the vertical direction and in the front-rear direction. Therefore, the natural frequency of the damper mass 204 is substantially the same in both the vertical direction and the front-rear direction.

  Therefore, energy absorption by the dynamic damper 200 is performed not only in the target vertical direction but also in the front-rear direction. As a result, the vertical energy absorption is relatively insufficient, which is the main vibration direction of the subframe. This causes a problem that vibration control in the vertical direction is insufficient. In other words, not only in the vertical direction that is desired to be effective, but also in the front-rear direction for the combined input of the upper and lower sides and the front and rear, there arises a problem that the vibration isolating effect in the vertical direction, which is the main vibration direction, is reduced. .

  In this case, it is conceivable to increase the mass of the damper mass 204, but this increases the cost of the dynamic damper 200 and increases the weight of components mounted on the vehicle. Therefore, it is not practical to take such measures.

Incidentally, a dynamic damper having a gate-shaped mounting member as described above and having a damper mass disposed in an inner space thereof is disclosed in the following Patent Document 5 as a dynamic damper for a vehicle seat. .
However, the one disclosed in Patent Document 5 is also one in which the rubber elastic body undergoes shear elastic deformation as a whole both in the vertical direction and in the front-rear direction when used as described above, as shown in FIG. It contains the same problem.

  As described above, the case where the dynamic damper is used for the sub-frame has been described, but such a problem is caused by vibrating the dynamic damper not only in the vertical direction but also in the front-rear direction, and in the tilt direction by combining them. This is a problem that can occur in common when applied to a vibrating body whose vibration direction is not constant.

JP 2005-69285 A JP 2003-194141 A Japanese Utility Model Publication No. 6-16817 JP 2000-297838 A JP 2007-263181 A

  In the present invention, against the background described above, when applied to a vibrating body that vibrates not only in the vertical direction, which is the main vibration direction, but also in the longitudinal direction, the desired vertical vibration can be effectively prevented. The purpose of the present invention is to provide a dynamic damper for a vehicle that can be used.

  Thus, according to the first aspect of the present invention, (a) a pair of leg portions disposed on both sides in the vehicle left-right direction so as to stand up and down from the mounting surface, and the pair of leg portions opposite to the mounting surface A rigid plate-shaped mounting member having a gate shape as a whole, and (b) a damper mass disposed in a space formed inside the mounting member. And (c) a state in which a vertical inner surface on the void side of the pair of leg portions and a vertical opposing surface on the damper mass side facing the leg portions in the left-right direction are connected in the left-right direction. In the vehicular dynamic damper, the leg portion of the mounting member is disposed in a direction opposite to the void along the front and rear edges in the front-rear direction of the vehicle. Reinforcing ribs standing from the plate surface are provided, and the front and rear sides of the front and rear reinforcing ribs are provided. A protruding piece is protruded in the left-right direction from the front and rear end portions of the opposing surface on the damper mass side at a position outside the front and rear to the front and rear reinforcing ribs. A rubber elastic body is provided in a state of connecting the vertical surface of the projecting piece and the vertical surface of the protruding piece, the left and right rubber arm portions connecting the inner surface of the leg portion and the opposing surface on the damper mass side, and the reinforcement The rubber elastic body is provided with a rubber arm portion in the front-rear direction connecting the vertical surface of the rib and the vertical surface of the protruding piece.

  According to a second aspect of the present invention, in the first aspect, the projecting piece is projected to a position overlapping the reinforcing rib in the front-rear direction.

  According to a third aspect of the present invention, in any one of the first and second aspects, a rigid holding member that is separate from the damper mass is disposed in the space, and the holding member is fixed to the mounting member. The damper mass is attached to and held by the holding member, and the opposing surface and the protruding piece are provided on the holding member.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the dynamic damper is attached to a subframe of a vehicle and is used for a subframe that performs vibration isolation.

Effects and effects of the invention

  As described above, the dynamic damper of the present invention is provided with the reinforcing ribs standing from the plate surface along the front and rear edges of the leg portion of the gate-shaped mounting member, and in the left-right direction on the damper mass side. Protruding pieces that protrude and oppose to the reinforcing ribs in the front-rear direction are provided, and a rubber arm portion in the left-right direction connecting the vertical inner surface on the void side of the leg portion and the vertical opposing surface on the damper mass side, and reinforcement A rubber elastic body is provided with a rubber arm portion in the front-rear direction connecting the rib and the protruding piece.

  In the case of the dynamic damper of the present invention, each of the left and right rubber arm portions and the front and rear rubber arm portions of the rubber elastic body includes a vertical surface of the mounting member and a vertical surface on the damper mass side, each of which forms a gate shape. The rubber arm portions in the left-right direction and the rubber arm portions in the front-rear direction are entirely sheared and elastically deformed in the vertical direction.

On the other hand, in the front-rear direction, the rubber arm portion in the left-right direction undergoes overall shear elastic deformation, but the rubber arm portion in the front-rear direction is elastically deformed in the front-rear direction with compression or tensile elastic deformation or compression or deformation of the tensile component. To do.
Therefore, in the dynamic damper of the present invention, the spring constant in the front-rear direction is large and the spring ratio is large with respect to the spring constant in the vertical direction of the rubber elastic body.

  Therefore, when the spring constant in the vertical direction of the rubber elastic body is tuned to the natural frequency (resonance frequency) in the vertical direction, which is the main vibration direction of the vibration body, the spring characteristics in the front-back direction of the rubber elastic body can be hardened. When the main vibrating body vibrates in the front-rear direction, it can be effectively suppressed that the damper mass vibrates greatly in the front-rear direction.

  As a result, it is possible to vibrate the damper mass in a vertical direction with a large amplitude with respect to the vertical vibration of the vibrating body, thereby effectively suppressing the vertical resonance phenomenon of the main vibrating body. It is possible to sufficiently exhibit the vibration proof performance.

  In addition, the dynamic damper of the present invention can suppress or prevent vibrations in the vertical direction of the vibrating body without increasing the mass of the damper mass. Therefore, increasing the mass of the damper mass increases the cost and weight of the dynamic damper as a vehicle-mounted component. The problem of increasing can be avoided.

The dynamic damper of the present invention also has another advantage in that the reinforcing rib provided for the rigidity increase and reinforcement of the gate-shaped mounting bracket is effectively utilized as a surface for providing the front and rear rubber arms. It is a feature.
Thereby, it is not necessary to provide the attachment member with a special portion for providing the front and rear rubber arm portions, and the structure of the attachment member can be maintained in a simple structure.

In the present invention, it is not always necessary to cause the protruding piece on the damper mass side to protrude long in the left-right direction until it overlaps in the front-rear direction with respect to the reinforcing rib on the mounting member side that forms the gate shape. It is desirable that the protruding piece is protruded long to a position overlapping with the reinforcing rib in the front-rear direction, and a rubber arm portion in the front-rear direction is provided so as to connect the protruding piece and the reinforcing rib until reaching the protruding end.
In this way, the spring characteristic (front-rear direction spring characteristic) of the rubber arm part in the front-rear direction can be made even more effective, and the spring ratio between the spring characteristic in the up-down direction and the spring characteristic in the front-rear direction. Can be increased more effectively.

  In the present invention, a rigid holding member that is separate from the damper mass is arranged in a space inside the gate-shaped attachment member, and is fixed to the attachment member, and the damper mass is attached to the holding member. It can be made to hold | maintain (Claim 3).

  In this way, it is not necessary to directly adhere the rubber elastic body to the damper mass, and therefore, when the rubber elastic body is vulcanized, a large (heavy) and large shape damper mass is set in the mold. In addition to facilitating the vulcanization molding operation of the rubber elastic body, the above-mentioned protruding piece can be provided on the holding member, and the protruding piece can be formed more easily than the case where the protruding piece is provided directly on the damper mass. Benefits are gained.

  As is apparent from the above description, the present invention is particularly suitable as a dynamic damper for a subframe of a vehicle (claim 4).

Next, an embodiment in which the present invention is applied to a dynamic damper for a subframe will be described in detail with reference to the drawings.
In FIG. 1, reference numeral 10 denotes a dynamic damper, and the dynamic damper 10 is mounted on the upper side of the subframe 12 with the upper surface of the subframe 12 as a mounting surface 14.

This dynamic damper 10 has a metal-made rigid attachment member 16 having a gate shape as a whole, and is attached to a metal damper mass 18 and its holding member 20 and damper mass 18 side in a space inside thereof. A pair of left and right rubber elastic bodies 24 that elastically connect the member 16 is disposed.
Here, the dynamic damper 10 is attached to the subframe 12 with the left-right direction in the drawing in the left-right direction of the vehicle, the up-down direction in the drawing in the up-down direction, and the direction perpendicular to the paper surface in the front-rear direction of the vehicle. The upward direction in the figure is the upward direction of the vehicle.

  The gate-shaped attachment member 16 is formed by bending a metal plate material, and includes a pair of left and right leg portions 26 that stand upward from the attachment surface 14 at a right angle, and the leg portions 26 are attached to the attachment surface 14. It has the connection part 28 connected with the left-right direction in the upper edge part on the opposite side.

  An attachment part 30 bent at a right angle along the attachment surface 14 is provided at the lower ends of the pair of leg parts 26, and the attachment member 16 is attached to a fastener such as a bolt in the attachment hole 32 of the attachment part 30. Are fixedly mounted on the mounting surface 14.

As shown in FIG. 3 (A), the mounting member 16 is provided with a pair of reinforcing ribs 34 at the front and rear ends before and after standing upright from the plate surface in the direction opposite to the void. Yes.
Here, the reinforcing ribs 34 are formed along the front and rear edges of the mounting member 16 and over the entire length of the mounting member 16.
In the figure, reference numeral 34 a denotes a connecting rib formed along the connecting portion 28, and 34 b denotes a leg rib formed along the leg portion 26.

The connecting portion 28 is formed with a circular and through-opening 36 through which a fastening bolt 44 described later is inserted at a central position in the left-right direction.
Further, the void side surfaces of the pair of leg portions 26 form a vertical inner surface 38 that is perpendicular to the mounting surface 14 as shown in FIGS. 1 and 4.
Here, the inner surface 38 is a flat surface in both the vertical direction and the front-rear direction.

The holding member 20 is also configured by bending a metal plate, and includes a pair of left and right falling portions 40 oriented in parallel with the pair of leg portions 26 in the mounting member 16, and upper ends of the falling portions 40. And a holding portion 42 that connects the portions in the left-right direction, and has a U-shape as a whole.
Here, as shown in FIG. 3B, the holding portion 42 has a size in the front-rear direction larger than that of the pair of falling portions 40, and the front end portion and the rear end portion are separated from the falling portions 40. It is projected in the front-rear direction.

The holding portion 42 is a portion that holds the metal damper mass 18, and a circular and penetrating insertion hole 43 for inserting the fastening bolt 44 is formed at the center thereof.
On the other hand, as shown in FIG. 3, the metal damper mass 18 is a flat block shape having a quadrangular planar shape, and is provided with a female screw hole 45 at the center of the upper surface.

As shown in FIG. 1, the damper mass 18 is fastened to the holding portion 42 by screwing a fastening bolt 44 inserted downward into the insertion hole 43 of the holding portion 42 into the female screw hole 45, and is suspended by the holding portion 42. Retained.
A circular protrusion 46 is provided around the female screw hole 45 on the upper surface of the damper mass 18, and the upper surface of the protrusion 46 is brought into contact with the holding part 42.

The damper mass 18 is brought into contact with the holding member 20 only at the protruding portion 46, and the other part is not in contact with the holding member 20.
Specifically, as shown in FIG. 1, the damper mass 18 is in a state where the upper surface forms a gap with the holding portion 42 except for the protruding portion 46, and the left and right side faces the falling portion 40. It is hold | maintained at the holding member 20 in the state which forms a clearance gap between them.

In this embodiment, the outer surfaces of the pair of left and right falling portions 40 in the holding member 20 are relative to the inner surfaces 38 of the corresponding pair of leg portions 26 in the mounting member 16 as shown in FIGS. A vertical facing surface 48 facing in the left-right direction is formed.
The facing surface 48 is a surface parallel to the inner surface 38, and is a flat surface in any of the vertical direction and the front-rear direction.

In this embodiment, as shown in FIGS. 3 and 4, the front and rear ends of the pair of left and right falling portions 40 in the holding member 20 are front and rear with respect to the front and rear reinforcing ribs 34 in the mounting member 16. A pair of protruding pieces 50 are protruded in the left-right direction so as to face each other.
Here, each protrusion piece 50 is extended in parallel with the left-right direction with respect to the leg rib 34b. Further, as shown in the partially enlarged view of FIG. 4, these protruding pieces 50 are protruded greatly in the left-right direction to a position where a part of the tip side overlaps with the leg rib 34b in the front-rear direction (overlap). ing.

The pair of left and right rubber elastic bodies 24 are integrally vulcanized and bonded to the falling part 40 of the holding member 20 and the leg part 26 of the mounting member 16 in a state of being connected to the left and right.
However, in the dynamic damper shown in FIG. 7, the rubber elastic body 208 simply connects the vertical inner surface 214 of the leg portion 210 and the opposing surface 216 of the falling portion of the holding member 206 to the left and right, that is, the rubber elastic body 208. However, in this case, the rubber elastic body 24 has a rubber arm portion in the front-rear direction in addition to the rubber arm portion in the left-right direction.

  Specifically, in the present embodiment, the rubber elastic body 24 includes an inner vertical inner surface 38 in the leg portion 26 and a falling portion 40 on the holding member 20 side facing the inner surface 38 as shown in FIGS. A mode in which the opposing surface 48 is connected in the left-right direction, and a pair of front and rear protruding pieces 50 provided on the falling portion 40 and a pair of front and rear leg ribs 34b in the front and rear portions 26 are connected in the front-rear direction. Is provided.

  In FIG. 4, 52 indicates a left and right rubber arm portion that connects the vertical inner surface 38 on the leg portion 26 side and the facing surface 48 of the falling portion 40 in the left and right direction, and 54 indicates a protruding piece 50. It represents a pair of rubber arms before and after connecting the leg ribs 34b in the front-rear direction.

The front and rear rubber arm portions 54 each have a curved surface in which the outer surface in the left-right direction gradually transitions rightward or leftward as it proceeds from the protruding piece 50 toward the leg rib 34b.
The rubber arm portion 52 in the left-right direction is provided with a straight portion (vacant space) 56 penetrating in the up-down direction and having a long hole shape in the front-rear direction.

  Further, as shown in FIGS. 2 and 5, the rubber arm portion 54 in the front-rear direction has a vertical dimension that is substantially the same as the vertical dimension of the protruding piece 50. Strictly speaking, the dimension in the vertical direction is slightly larger than that of the protruding piece 50, and the protruding piece 50 is embedded in the rubber arm portion 54 in the front / rear direction except for the outer surface of the protruding piece 50 in the front / rear direction.

The above-described straight portion 56 is provided on the rubber arm portion 52 in the left-right direction. The provision of the rubber arm portion 54 in the front-rear direction not only hardens the spring characteristics in the front-rear direction, but also in the vertical direction. This is to prevent the spring characteristics from becoming hard. That is, in order to make the spring characteristics in the vertical direction equal to the case where only the left and right rubber arms are provided, the spring characteristics are provided for adjustment.
In this embodiment, the dynamic damper 10 has a mass of the damper mass 18 of 1500 g and a mass of the entire dynamic damper 10 of 1900 g.

In this embodiment, when the damper mass 18 vibrates in the vertical direction, the rubber elastic body 24 is sheared and elastically deformed in the vertical direction as a whole.
Specifically, both the left and right rubber arm portions 52 and the front and rear rubber arm portions 54 in FIG. 4 are shear elastically deformed in the vertical direction as a whole.

  On the other hand, when the damper mass 18 vibrates in the front-rear direction, the rubber arm portion 52 in the left-right direction undergoes shear elastic deformation in the front-rear direction, but one of the pair of front and rear rubber arm portions 54 in the front-rear direction is compressed. Elastic deformation, the other is tensile elastic deformation.

  Strictly speaking, when the pair of front and rear rubber arms 54 in the front-rear direction is deformed in the front-rear direction, a large compressive deformation occurs on one side and a large tensile deformation occurs on the other side. Further, when the rubber arm portion 54 is deformed in the front-rear direction opposite to this, a large tensile deformation occurs on one side and a large compressive deformation occurs on the other side.

  Therefore, in the dynamic damper 10 of this embodiment, the spring characteristics in the front-rear direction are larger than the spring characteristics in the vertical direction of the rubber elastic body 24, and the spring ratio is also large.

  6 shows, as a comparative example, an example in which the portal-shaped mounting member of the sub-frame dynamic damper shown in FIG. 7 is arranged in the left-right direction of the vehicle and the dimensions and shape are changed. 6, the mass and shape of the damper mass are larger than those shown in Fig. 7, and the shape of the mounting member forming the gate shape is also changed accordingly, except that the rubber elastic body is a rubber in the left-right direction. It consists only of arms).

For each of the dynamic damper 10 of the present embodiment and the dynamic damper 10A of the comparative example of FIG. 6, the natural frequencies in the vertical direction and the front-rear direction are obtained by FEM analysis, and the ratio thereof (the natural frequency in the front-rear direction). / Natural frequency in the vertical direction), the ratio in the comparative example was 0.97, and the vertical and front and back were almost equal, whereas in the present embodiment, the ratio was 1.48. It was confirmed that it was significantly larger than the example.
Note that the natural frequency in the vertical direction is tuned to 38.4 Hz in the comparative example and 38.0 Hz in the embodiment. In other words, the above values are the results for those tuned so that the natural frequencies in the vertical direction are substantially equal.

  When the modal analysis was performed for the comparative example of FIG. 6, the ratio of the natural frequency in the front-rear direction to the natural frequency in the vertical direction was 0.97, and the result of the FEM analysis and the result of the modal analysis were It was a good match.

  Here, the FEM analysis is to calculate the natural frequency according to a predetermined program by the finite element method based on the shape and physical property value of the rubber elastic body, and the modal analysis is performed by hitting the damper mass with an impact hammer. The acceleration of the corresponding part is obtained as data by the acceleration sensor attached to the sensor, and the natural frequency is obtained by numerical calculation based on the data.

  In the case of the dynamic damper 10 of the present embodiment as described above, the rubber member 52 in the left-right direction and the rubber arm portion 54 in the front-rear direction in the rubber elastic body 24 both form a portal shape and the damper mass 18 side. Since the holding members 20 are connected to the respective vertical surfaces, the left and right rubber arm portions 52 and the front and rear rubber arm portions 54 are entirely shear elastically deformed in the vertical direction. To do.

On the other hand, in the front-rear direction, the rubber arm portion 52 in the left-right direction undergoes overall shear elastic deformation, but the rubber arm portion 54 in the front-rear direction elastically deforms in the front-rear direction with compression or tensile deformation.
Therefore, in the dynamic damper 10 of this embodiment, the spring constant in the front-rear direction is larger than the spring constant in the vertical direction of the rubber elastic body 24, and the spring ratio is also large.

  Therefore, when the vertical spring constant of the rubber elastic body 24 is tuned to the natural frequency (resonance frequency) in the vertical direction which is the main vibration direction of the vibration body (subframe 12), the spring in the front-rear direction of the rubber elastic body 24 is tuned. The characteristics can be hardened, and when the main vibration body vibrates in the front-rear direction, the damper mass 18 can be effectively prevented from greatly vibrating in the front-rear direction.

  As a result, the damper mass 18 can be vibrated in the vertical direction with a large amplitude with respect to the vibration in the vertical direction of the vibrating body, thereby effectively suppressing the vertical resonance phenomenon of the main vibrating body. Anti-vibration performance can be fully demonstrated. That is, since the elastic characteristics of the rubber elastic body 24 in the front-rear direction are hard with respect to the composite input in the up-down direction and the front-rear direction, the damper mass 18 vibrates mainly in the up-down direction, thereby effectively obtaining the anti-vibration effect in the up-down direction. Can do.

  In addition, the dynamic damper 10 of the present embodiment can suppress or prevent vibrations in the vertical direction of the vibrating body without increasing the mass of the damper mass 18, and accordingly, the cost can be increased by increasing the mass of the damper mass 18 and as a vehicle-mounted component. The problem of an increase in the weight of the dynamic damper 10 can be avoided.

  The dynamic damper 10 of the present embodiment also effectively utilizes the reinforcing rib 34 provided for increasing rigidity and reinforcing the gate-shaped mounting member 16 as a surface for providing the rubber arm portion 54 in the front-rear direction. For this reason, it is not necessary to specially provide the mounting member 16 with a portion for providing the rubber arm portion 54 in the front-rear direction, and the structure of the mounting member 16 can be maintained in a simple structure.

  Further, in the present embodiment, the protruding piece 50 on the damper mass 18 side is protruded long to a position overlapping with the reinforcing rib 34 (leg rib 34b) in the front-rear direction, and the protruding piece 50 and the reinforcing rib 34 are reached until reaching the protruding end. Since the rubber arm portion 54 in the front-rear direction is provided so as to connect the (leg rib 34b), the spring characteristic (the spring characteristic in the front-rear direction) of the rubber arm portion 54 in the front-rear direction can be effectively hardened, The spring ratio between the vertical spring characteristics and the front-back spring characteristics can be increased more effectively.

Further, in the present embodiment, a rigid holding member 20 that is separate from the damper mass 18 is disposed in a space inside the mounting member 16 having a gate shape, and is fixed to the mounting member 16. Since the damper mass 18 is attached to and held at 20, the following advantages are obtained.
That is, it is not necessary to directly adhere the rubber elastic body to the damper mass 18, and therefore, when the rubber elastic body 24 is vulcanized, it is necessary to set the damper mass 18 having a large mass (heavy) and a large shape in the mold. In addition to facilitating the vulcanization molding operation of the rubber elastic body 24, the above-mentioned protruding piece 50 can be provided on the holding member 20, and the protruding piece 50 is easier than the case where the protruding piece is directly provided on the damper mass 18. The advantage that can be formed is obtained.

Although the embodiment of the present invention has been described in detail above, this is merely an example.
For example, in the present invention, the damper mass and the mounting member can be directly connected by a rubber elastic body, and in the above example, the protruding piece 50 protrudes greatly to a position overlapping with the leg rib 34b in the front-rear direction. However, in some cases, the protruding piece 50 may protrude from the leg rib 34b in such a length that it does not overlap in the front-rear direction.
In the above-described embodiment, the protruding piece 50 is provided in parallel to the leg rib 34b. However, the present invention has the gist that the protruding piece 50 may be provided non-parallel to the leg rib 34b. The present invention can be configured in various forms without departing from the scope.

It is sectional drawing which shows the dynamic damper which is one Embodiment of this invention. It is a perspective view of the dynamic damper of the embodiment. It is a perspective view which decomposes | disassembles and shows the dynamic damper of the embodiment to each component. It is a top view which cuts and shows the principal part of the dynamic damper of the embodiment. It is VV sectional drawing of FIG. It is a figure of the dynamic damper as a comparative example. It is a figure which shows an example of the conventional dynamic damper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dynamic damper 12 Sub-frame 14 Mounting surface 16 Mounting member 18 Damper mass 20 Holding member 24 Rubber elastic body 26 Leg part 28 Connection part 34 Reinforcement rib 38 Vertical inner surface 48 Opposing surface 50 Projection piece 52 Left-right rubber arm part 54 Front-back direction Rubber arm

Claims (4)

(a) A pair of leg portions arranged on both sides in the vehicle left-right direction so as to stand up and down from the mounting surface, and the pair of leg portions connected in the left-right direction at the end opposite to the mounting surface A rigid plate-like mounting member having a portal shape as a whole, (b) a damper mass disposed in a cavity formed inside the mounting member, and (c) the pair of leg portions A rubber elastic body disposed in a state in which the vertical inner surface on the void side and the vertical opposing surface on the damper mass side facing the leg portion in the left-right direction are connected in the left-right direction. In a dynamic damper for a vehicle having
The leg portion of the mounting member is provided with reinforcing ribs standing from the plate surface in the opposite direction to the void along the front and rear edges in the vehicle longitudinal direction,
The front and rear reinforcing ribs protrude in a front-rear direction from the front and rear end portions of the damper mass side at positions outside the front and rear reinforcing ribs in the front-rear direction. Protruding a piece in the left-right direction, and providing a rubber elastic body in a state connecting the vertical surface of the reinforcing rib and the vertical surface of the protruding piece,
The left and right rubber arm portions that connect the inner surface of the leg portion and the opposing surface on the damper mass side, and the front and rear rubber arm portions that connect the vertical surface of the reinforcing rib and the vertical surface of the protruding piece, The rubber elastic body is provided with a dynamic damper for a vehicle.   2. The dynamic damper for a vehicle according to claim 1, wherein the protruding piece protrudes to a position overlapping with the reinforcing rib in the front-rear direction.   In any one of Claims 1 and 2, a rigid holding member that is separate from the damper mass is disposed in the space, the holding member is fixed to the mounting member, and the damper mass is A vehicular dynamic damper, wherein the vehicular dynamic damper is attached to and held by a holding member, and the holding member is provided with the facing surface and the protruding piece.   The dynamic damper for a vehicle according to any one of claims 1 to 3, wherein the dynamic damper is for a subframe that is attached to a subframe of the vehicle and acts to prevent vibration.

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