JP7737873B2 - Vibration reduction device and vehicle seat - Google Patents

Description

The present invention relates to a vibration reduction device and a vehicle seat.

Patent Document 1 below discloses a vibration reduction device (vibration damping device) and a vehicle seat equipped with this vibration reduction device. The vibration reduction device described in this document allows a weight member to move back and forth along a mounting bolt against the biasing force of a spring (coil spring), thereby suppressing vibration in the vehicle seat.

Japanese Patent Application Laid-Open No. 2021-6453

In a vibration reduction device in which the weight is supported by a spring, it is desirable to be able to easily engage the weight with the spring. Furthermore, in a vibration reduction device in which the weight is supported by a spring, it is desirable to be able to absorb vibrations not only in one direction but also in other directions.

In consideration of the above, the present invention aims to provide a vibration reduction device and vehicle seat that can easily engage the weight and spring and absorb vibrations not only in one direction but also in other directions.

The vibration reduction device of the first aspect comprises a pair of springs arranged in pairs with their axes overlapping each other, each of which uses a coil spring that is compressed or tensioned in the axial direction; a weight body that is set to a predetermined mass and is covered all around with a covering member formed using a viscoelastic material ; and a pair of locking portions that are formed by the covering member that covers the weight body and are provided on one side and the other side in the axial direction, and with the pair of locking portions respectively locked to the pair of springs, the weight body is offset to one side of the direction intersecting the axial direction with respect to the axes of the pair of springs and is supported so as to be displaceable in the axial direction and in the direction intersecting the axial direction.

According to the vibration reduction device of the first aspect, the entire circumference of the weight body is covered with a covering member made of a viscoelastic material , a pair of locking portions are formed integrally with the weight body by the covering member , and compression coil springs are used to lock the locking portions to the springs. This makes it easier to lock (engage) the pair of locking portions with the pair of springs than in a configuration in which the pair of locking portions are separate from the weight body. In other words, the weight can be easily supported by the pair of springs.
Furthermore, when the weight is supported by the pair of springs , the weight body is offset to one side of the axis of the pair of springs in a direction intersecting the axial direction and is displaceable in the axial direction and in the direction intersecting the axial direction. This allows the covering member to absorb vibrations transmitted between the pair of springs and the weight body, and the covering member and the springs can absorb not only axial vibrations but also vibrations in the direction intersecting the axial direction.

The vibration reduction device of the second aspect is the vibration reduction device of the first aspect, further comprising brackets to which the pair of springs are respectively attached on the sides opposite to the sides attached to the locking portions, the pair of springs being compression coil springs compressed between the weight body and the brackets, and the pair of locking portions being formed in a convex shape that protrudes from the weight body and are inserted into the inner periphery of the pair of springs.

With the second aspect of the vibration reduction device, the vibration reduction device can be easily attached to the object by attaching the bracket to the object. Furthermore, by inserting the pair of locking portions into the inner peripheries of the pair of springs, the weight can be easily supported by the pair of springs.

The third aspect of the vibration reduction device is the vibration reduction device of the second aspect, wherein the pair of locking portions include an insertion portion that is inserted into the inner periphery of the spring, and a retaining portion that protrudes from the insertion portion in a direction perpendicular to the axial direction.

With the vibration reduction device of the third aspect, the insertion portions of the pair of locking portions are inserted into the inner peripheries of the pair of springs, making it possible to easily support the weight on the pair of springs. Furthermore, because the pair of locking portions have anti-slip portions, it is possible to prevent the insertion portions of the pair of locking portions from slipping out from the inner peripheries of the pair of springs.

A fourth aspect of the vehicle seat includes a seat cushion that supports the buttocks of a seated occupant, a seat back that supports the back of the seated occupant, and a vibration reduction device of any one of the first to third aspects that is provided on at least one of the seat cushion and the seat back.

According to the fourth aspect of the vehicle seat, the vibration reduction device according to any one of the first to third aspects is provided on at least one of the seat cushion and the seat back, thereby suppressing vibrations of the seat in each direction.

The vibration reduction device and vehicle seat of the present invention have the excellent effect of facilitating the engagement between the weight and spring, and absorbing not only vibrations in one direction of the seat, but also vibrations in other directions of the seat.

1 is a side view showing a vehicle seat equipped with a vibration reduction device according to a first embodiment; 1 is a perspective view showing a vibration reduction device according to a first embodiment; 3 is a side view showing a weight and a pair of springs of the vibration reduction device of the first embodiment. FIG. FIG. 10 is an enlarged side view showing a locking portion and the like of a vibration reduction device according to a second embodiment. FIG. 10 is a side view showing a weight and a pair of springs of a vibration reduction device according to a third embodiment. FIG. 10 is a side view showing a weight and a pair of springs of a vibration reduction device according to a fourth embodiment.

The vehicle seat 12 equipped with the vibration reduction device 10 of the first embodiment will be described using Figures 1 to 3.

Figure 1 shows a side view of a vehicle seat 12 equipped with a vibration reduction device 10 according to the first embodiment, viewed from the left side of the seat. In the figure, arrow FR indicates the front side of the seat, arrow UP indicates the upper side of the seat, arrow RH indicates the right side in the width direction of the seat, and arrow LH indicates the left side in the width direction of the seat. Furthermore, in the following description, when the terms "front-rear," "up-down," and "left-right" are used unless otherwise specified, they refer to front-rear in the front-rear direction of the seat, up-down in the up-down direction of the seat, and left-right in the width direction of the seat.

As shown in FIG. 1, the vehicle seat 12 includes a seat cushion 14 that supports the seated occupant's buttocks from below, a seat back 16 that supports the seated occupant's back from the rear side of the seat, and a headrest 18 that supports the seated occupant's head from the rear side of the seat. The seat back 16 is attached to the rear end of the seat cushion 14 and can be tilted in the fore-and-aft direction. The headrest 18 is attached to the upper end of the seat back 16. The vibration reduction device 10 is provided inside the upper portion of the seat back 16 and is fixed to a seat back frame that forms the framework of the seat back 16. The vibration reduction device 10 may be provided on either the seat cushion 14 or the seat back 16, or on both the seat cushion 14 and the seat back 16.

As shown in FIG. 2, the vibration reduction device 10 is configured to include a bracket 20 fixed to the seat back frame, a weight 22 disposed within the bracket 20, and a pair of springs 24 disposed between the bracket 20 and the weight 22. In the following explanation, the configuration of the bracket 20, spring 24, weight 22, etc. will be explained, showing the various directions when the vibration reduction device 10 is attached to the seat back 16.

The bracket 20 is formed by bending a steel plate cut to a predetermined shape. The bracket 20 has a rectangular first extension portion 26 that extends in the up-down and left-right directions, with the front-to-rear direction being the thickness direction. The bracket 20 also has a pair of second extension portions 28 that bend forward from the upper and lower ends of the first extension portion 26 and are arranged approximately parallel to each other. A pair of locking pins 32 are fixed to the center portions of the pair of second extension portions 28 in the front-to-rear and left-to-right directions. The bracket 20 also has a pair of third extension portions 30 that bend upward and downward from the front ends of the pair of second extension portions 28. The bracket 20 also has a pair of tongue-shaped fixing portions 34 that extend upward and downward from the center portions of the pair of third extension portions 30 in the left-to-right direction. Each of the pair of fixing portions 34 has an insertion hole 36 formed therein, through which a bolt or the like (not shown) is inserted. The bracket 20 is fixed to the seat back frame of the seat back 16 via a bolt inserted through the insertion hole 36. The space enclosed by the first extension portion 26 and the pair of second extension portions 28 in the bracket 20 forms a weight placement space 38 in which a weight 22 (described below) is placed. In this embodiment, the weight placement space 38 is open on the front, right, and left sides, and is closed on the rear side by the first extension portion 26.

As shown in Figures 2 and 3, the pair of springs 24 are compression coil springs set to the same shape and dimensions and are compressible in the axial direction. In this embodiment, the axial direction and the vertical direction coincide. One end of the pair of coil springs 24 forms a weight locking portion 40 into which a locking portion 50 of the weight 22 (described below) is inserted and locked to the locking portion 50. The other end of the pair of coil springs 24 forms a bracket locking portion 42 into which a locking pin 32 fixed to the second extension portion 28 of the bracket 20 is inserted and locked to the bracket 20 via the locking pin 32. The pair of springs 24 are positioned between the weight 22 and the second extension portion 28 of the bracket 20 in a state compressed from their natural length L1.

As shown in FIG. 3, the weight 22 includes a weight body 44 with a predetermined mass and a covering member 46 that covers the weight body 44. The weight body 44 is formed of a metal material such as iron or lead in an elongated spheroid shape with its longitudinal direction extending vertically. The covering member 46 is formed of a viscoelastic material such as rubber. The covering member 46 includes a weight body covering portion 48 that covers the weight body 44 and a pair of engaging portions 50 that protrude upward and downward from the upper and lower ends of the weight body covering portion 48, respectively. A portion 50A of the engaging portion 50 facing the weight body 44 is cylindrical and has an outer diameter D1. A portion 50B of the engaging portion 50 facing the opposite side of the weight body 44 gradually narrows as it approaches the opposite side of the weight body 44. Here, the outer diameter D1 of the portion 50A of the locking portion 50 on the weight main body 44 side is set to a dimension that allows the locking portion 50 to be inserted into the weight locking portion 40 of the spring 24. Note that the locking portion 50 may be inserted into the weight locking portion 40 of the spring 24 with a clearance, or may be inserted with a light press fit.

(Actions and Effects of the Present Embodiment)
Next, the operation and effects of this embodiment will be described.

As shown in Figures 1, 2, and 3, in the vibration reduction device 10 of the first embodiment described above, the pair of locking portions 50 are integrally formed with the weight body 44. This makes it easier to lock (engage) the pair of locking portions 50 with the pair of springs 24 than in a configuration in which the pair of locking portions 50 are separate from the weight body 44. That is, the weight 22 can be easily supported by the pair of springs 24. In particular, in this embodiment, the pair of locking portions 50 of the weight 22 are inserted into the inner peripheral portions of the weight locking portions 40 of the pair of springs 24, making it easier to support the weight 22 on the pair of springs 24. Furthermore, when the weight 22 is supported by the pair of springs 24, the weight 22 is displaceable in the up-down, front-rear, and left-right directions. This allows the weight 22 to be displaced in response to vibrations input to the vehicle seat 12 in each direction. As a result, the vibration reduction device 10 of the first embodiment can absorb not only up-down vibrations input to the vehicle seat 12, but also front-rear and left-right vibrations.

The vibration reduction device 10 of this embodiment is also configured to include a bracket 20. This allows the vibration reduction device 10 to be easily attached to the object (in this embodiment, the seatback frame) by attaching the bracket 20 to the object. It is also possible to omit the bracket 20 and directly attach the pair of springs 24 on the side opposite to the side that engages with the weight 22 to the object.

Furthermore, in the vibration reduction device 10 of this embodiment, the weight body 44 is covered with a covering member 46 made of a viscoelastic material, and a portion of the covering member 46 forms a pair of locking portions 50. This allows vibrations transmitted between the pair of springs 24 and the weight body 44 to be absorbed by the covering member 46 (particularly the pair of locking portions 50 and their surrounding areas).

(Vibration reduction device 52 of the second embodiment)
Next, a vibration reduction device 52 of a second embodiment will be described. Note that, in the vibration reduction device 52 of the second embodiment, components and parts corresponding to those of the vibration reduction device 10 of the first embodiment described above will be assigned the same reference numerals as those corresponding to those of the vibration reduction device 10 of the first embodiment, and their description may be omitted.

As shown in Figure 4, in the vibration reduction device 52 of this embodiment, the locking portion 50 of the weight 22 includes an insertion portion 54 that is inserted into the inner periphery of the weight locking portion 40 of the spring 24, and a retaining portion 56 that protrudes from a portion 54A of the insertion portion 54 on the weight main body 44 side in a direction perpendicular to the vertical direction (axial direction).

More specifically, the retaining portion 56 protrudes radially outward from the vertical middle of the portion 54A of the insertion portion 54 that faces the weight body 44. The retaining portion 56 is also provided around the entire circumferential circumference of the portion 54A of the insertion portion 54 that faces the weight body 44. Furthermore, the outer diameter D2 of the retaining portion 56 is set to be larger than the inner diameter D3 of the weight locking portion 40 of the spring 24. When the insertion portion 54 is inserted into the weight locking portion 40 of the spring 24, the retaining portion 56 is deformed and pushed into the weight locking portion 40 of the spring 24, and is positioned within the vertical gap 58 of the spring 24.

In the vibration reduction device 52 of this embodiment described above, the locking portion 50 has a locking portion 56, which prevents the insertion portion 54 of the locking portion 50 from coming out from the inner periphery of the weight locking portion 40 of the spring 24.

(Vibration reduction device 60 of the third embodiment)
Next, a vibration reduction device 60 according to a third embodiment will be described. Note that in the vibration reduction device 60 according to the third embodiment, components and parts corresponding to those of the vibration reduction device 10 according to the first embodiment will be given the same reference numerals as those corresponding to those of the vibration reduction device 10 according to the first embodiment, and their description may be omitted.

As shown in FIG. 5 , in the vibration reduction device 60 of this embodiment, the pair of springs 24 are tension coil springs. The pair of springs 24 are set to the same shape and dimensions and are designed to be stretched when pulled in the axial direction. One end of the pair of coil springs 24 forms a weight locking portion 40 that is inserted into a locking hole 62 formed in a locking portion 50 of the weight 22 and locked to the locking portion 50. The other end of the pair of coil springs 24 forms a bracket locking portion 42 that is locked to the bracket 20. The pair of springs 24 are positioned between the weight 22 and the second extension portion 28 of the bracket 20 in a state stretched from their natural length L1.

The vibration reduction device 60 of this embodiment described above can also absorb vibrations input to a vehicle seat 12 or the like to which the vibration reduction device 60 is attached, just like the vibration reduction device 10 of the first embodiment in which the pair of springs 24 are compression coil springs.

(Vibration reduction device 64 of the fourth embodiment)
Next, a description will be given of a vibration reduction device 64 of a fourth embodiment. Note that, in the vibration reduction device 64 of the fourth embodiment, components and parts corresponding to those of the vibration reduction device 10 of the first embodiment described above will be given the same reference numerals as those corresponding to those of the vibration reduction device 10 of the first embodiment, and their description may be omitted.

As shown in Figure 6, in the vibration reduction device 64 of this embodiment, the weight body 44 is positioned offset in a direction perpendicular to the axial center line 66, which passes through the pair of engagement portions 50 in the vertical direction.

As with the vibration reduction device 10 of the first embodiment, the vibration reduction device 64 of this embodiment described above can absorb vibrations input to a vehicle seat 12 or the like to which the vibration reduction device 64 is attached. Whether or not the weight body 44 is offset from the axial center line 66 in a direction perpendicular to the axial center line 66 can be determined appropriately, taking into account the vibration characteristics of the vehicle seat 12 or the like.

The above describes one embodiment of the present invention, but the present invention is not limited to the above and can, of course, be implemented in various other modifications within the scope of its essence.

REFERENCE SIGNS LIST 10 Vibration reduction device 12 Vehicle seat 14 Seat cushion 16 Seat back 20 Bracket 22 Weight 24 Spring 44 Weight body 46 Covering member 50 Locking portion 52 Vibration reduction device 54 Insertion portion 56 Removal prevention portion 60 Vibration reduction device 64 Vibration reduction device

Claims (4)

A pair of springs, each of which is a coil spring that is axially compressed or tensioned, and is arranged in pairs with its axis overlapping each other ;
a weight having a weight body set to a predetermined mass and entirely covered with a covering member formed using a viscoelastic material ; and a pair of locking portions formed by the covering member covering the weight body and provided on one side and the other side in the axial direction, wherein, with the pair of locking portions respectively locked to the pair of springs, the weight body is offset with respect to axes of the pair of springs to one side in a direction intersecting the axial direction and is supported so as to be displaceable in the axial direction and in a direction intersecting the axial direction;
A vibration reduction device equipped with a The pair of springs further includes brackets to which the springs are respectively locked on the sides opposite to the sides locked on the locking portions,
The pair of springs are compressed between the weight body and the bracket ,
2. The vibration reduction device according to claim 1, wherein the pair of locking portions are formed in a convex shape protruding from the weight body and inserted into inner peripheries of the pair of springs. The vibration reduction device described in claim 2, wherein the pair of locking portions include an insertion portion that is inserted into the inner periphery of the spring, and a retaining portion that protrudes from the insertion portion in a direction perpendicular to the axial direction. a seat cushion that supports the buttocks of a seated occupant;
a seat back that supports the back of a seated occupant;
The vibration reduction device according to any one of claims 1 to 3, which is provided on at least one of the seat cushion and the seat back ;
A vehicle seat comprising: