Dynamic damper

Abstract

To provide a dynamic damper which is a simple construction used in a suspension device of a vehicle and is capable of varying damping force.SOLUTION: In a dynamic damper which is provided with a suspension 5 which is interposed between an upper spring member and a lower spring member in a vehicle and restrains the lower spring member from being vibrated and at the same time damping force restraining vibration is capable of varying, it includes, especially, a cylindrical body 10, a variable measure 13 which is supported so as to make it possible to vibrate the cylindrical body 10 inside by being sandwiched between a first spring 11 and a second spring 12 and a first guide member 31 as a pressurization member which pressurizes the a movable measure 13 from a direction intersecting with a vibration direction and composes so as to make it possible to vary damping force by adjusting load pressurizing from the pressurization member to the movable measure 13.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a dynamic damper for a vehicle capable of varying damping force.

Background Art

[0002] In order to improve the ride comfort and driving stability of a vehicle, a suspension is interposed between the wheels and the vehicle body of the vehicle. The suspension mainly includes a suspension arm for positioning the axle, a coil spring for supporting the vehicle weight and absorbing shocks, a shock absorber for damping the vertical movement of the vehicle body absorbed by the coil spring, a dynamic damper for damping vibrations, etc., and has roles such as absorbing shocks from the road surface and enhancing the followability (ground contact property) of the tire to the road surface.

[0003] Particularly in the suspension device equipped with the above dynamic damper, it is possible to further improve the ride comfort and driving stability due to the vibration damping effect of the dynamic damper. For example, Japanese Patent Application Laid-Open No. 2017-100697 discloses a suspension device equipped with a dynamic damper designed to damp the resonance frequency of the lower spring member and the vibrations around it by vertically moving a piston that partitions a cylinder filled with oil inside.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, in order to appropriately attenuate vibrations with a dynamic damper, it is important to appropriately set the damping force (corresponding to the force that converges vibrations, the same hereinafter) with respect to the object to which vibrations are to be attenuated (for example, the lower spring member of a vehicle in Patent Document 1 above). However, in a dynamic damper using oil and a piston as in Patent Document 1 above, if one attempts to adjust the damping force, a complicated structure such as an actuator or valve for changing the cross-sectional area of the orifice becomes necessary. Also, due to filling the cylinder with oil, a special seal structure for preventing oil leakage is also required.

[0006] On the other hand, in a dynamic damper using a biasing member such as a spring and a movable mass (mass body) as in Patent Document 2 above, in order to change the damping force (that is, the resistance to the movement of the movable mass), it is necessary to change the material or shape of the movable mass or the biasing member, and it cannot be easily changed.

[0007] The present invention has been made to solve the above-described conventional problems, and an object thereof is to provide a dynamic damper having a simple structure used in a vehicle suspension device and capable of varying the damping force.

Means for Solving the Problems

[0008] The dynamic damper according to the present invention for achieving the above object is a dynamic damper disposed in a suspension device interposed between an upper spring member and a lower spring member in a vehicle, and includes a cylinder body, a movable mass supported by an elastic body so as to be vibratable within the cylinder body, a pressing member that presses the movable mass from a direction intersecting the vibration direction, and a holding member that holds the pressing member and adjusts the load for pressing from the pressing member to the movable mass. Incidentally, more specifically, the "damping force" corresponds to the force that converges vibrations by the dynamic damper.

Effects of the Invention

[0009] According to the dynamic damper of the present invention having the above configuration, the damping force can be made variable with a simple structure of pressing a movable mass that vibrates inside the cylinder. Therefore, it is possible to easily adjust the damping force according to the spring lower member that is the object of damping vibration. By adjusting the damping force, a high vibration suppression effect can be expected for the vibration of the resonance frequency of the spring lower member and the frequencies around it.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0011] Hereinafter, the first embodiment and the second embodiment in which the dynamic damper according to the present invention is embodied will be described in detail with reference to the drawings.

[0012] [First Embodiment] First, the vehicle 2 equipped with the dynamic damper 1 according to the first embodiment will be described below. FIG. 1 is a schematic configuration diagram of the vehicle 2 according to the first embodiment.

[0013] Here, the vehicle 2 may be, for example, an automobile (internal combustion engine vehicle) having an internal combustion engine (engine, etc.) as a drive source, an automobile (electric vehicle, fuel cell vehicle, etc.) having an electric motor (motor, etc.) as a drive source, or an automobile (hybrid vehicle) having both of them as drive sources. Also, regardless of the vehicle type, it may be a passenger car, or a commercial large truck, bus, etc. Further, in the following description, it is assumed to be a four-wheel vehicle, but it may also be a two-wheel or three-wheel vehicle.

[0014] In order to improve the ride comfort and driving stability of the vehicle 2, suspension devices 5 are respectively interposed between the wheels 3 of the vehicle and the vehicle body (body) 4. Note that the suspension 5 is interposed at a total of four locations, namely, between the left front wheel and the vehicle body 4, between the right front wheel and the vehicle body 4, between the left rear wheel and the vehicle body 4, and between the right rear wheel and the vehicle body 4, and they are basically assumed to have the same structure. Hereinafter, one of these suspensions 5 will be described as an example. Also, the type of the suspension 5 is not particularly limited, and for example, a strut type, a double wishbone type, a multi-link type, a torsion beam type, etc. can be adopted. Also, an air suspension using an air spring instead of a metal spring may be used.

[0015] Here, the suspension 5 mainly includes a suspension arm (not shown) for positioning the axle, a coil spring 6 for supporting the vehicle weight and absorbing shocks, a shock absorber 7 for damping the vertical movement of the vehicle body 4 absorbed by the coil spring 6, a dynamic damper 1 that absorbs the target vibration energy and damps vibrations by adding an auxiliary mass body via a spring or the like, and plays roles such as absorbing shocks from the road surface and enhancing the followability (ground contact performance) of the tires to the road surface. In particular, in the first embodiment, a suspension with variable damping force is used as the damping characteristic of the dynamic damper 1. The details of the suspension 5 will be described later.

[0016] In addition, the vehicle 2 includes basic components of the vehicle 2 in addition to the components shown in FIG. 1, but only the components related to the suspension 5 will be described. Also, in the following description, the upper part supported by the suspension 5 of the vehicle 2, that is, the vehicle body 4, is also referred to as "above the spring", and the lower part that serves as the base in the suspension 5, that is, the wheel 3, is also referred to as "below the spring".

[0017] Next, among the components included in the vehicle 2, the configuration of the suspension 5 in particular will be described. FIG. 2 is a schematic configuration diagram of the suspension 5 according to the first embodiment.

[0018] As shown in FIG. 2, the suspension 5 has a coil spring 6, a shock absorber 7, and a dynamic damper 1. In FIG. 2, the coil spring 6 and the shock absorber 7 are separately illustrated for the sake of explanation, but actually, the coil spring 6 exists so as to surround the outside of the shock absorber 7 and they are arranged overlappingly so as to be coaxial with each other. However, it is also possible to arrange them on different axes. Further, the shock absorber 7 has a mechanism capable of electrically controlling (adjusting) the damping force (damping characteristics). Specifically, the shock absorber 7 has an actuator inside that operates based on the input current, and can change the opening degree of an orifice provided in the piston of the shock absorber 7, or change the opening degree between the valve body and the valve seat. Thereby, the flow rate of the lubricating oil flowing between the two oil chambers partitioned by the piston in the shock absorber 7 is controlled, and the damping force of the shock absorber 7 is adjusted. However, in the first embodiment, the function of adjusting the damping force in the shock absorber 7 is not essential, and the shock absorber 7 without the function of adjusting the damping force may be used.

[0019] On the other hand, as shown in FIG. 2, in the suspension 5, the dynamic damper 1 is attached to the spring lower member that serves as a base, that is, on the wheel 3 side. The dynamic damper 1 is also called a vibration absorber and has a function of absorbing the target vibration energy and damping the vibration by adding an auxiliary mass body via a spring or the like. As a basic structure, it includes a first spring (elastic body) 11 that is an elastic body, a second spring (elastic body) 12, and a movable mass 13 that is sandwiched therebetween and supported so as to be vibratable in the vertical direction, and the movable mass 13 corresponds to the mass body. In particular, in the first embodiment, it is attached to the spring lower member and is designed to suppress the vibration at the resonance frequency of the spring lower member and the frequencies around it. Then, when the movable mass 13 sandwiched between the first spring 11 and the second spring 12 vibrates, the dynamic damper 1 absorbs the vibration energy of the spring lower member and damps the vibration. Further, by damping the vibration of the spring lower member, it becomes possible to also damp the vibration of the spring upper member connected via the spring lower member and the suspension 5 as a result.

[0020] The structure of the dynamic damper 1 will be described in more detail below with reference to FIGS. 3 to 6. FIG. 3 is a front view of the dynamic damper 1, FIG. 4 is a cross-sectional view of the dynamic damper 1 cut axially along line A-A in FIG. 3, FIG. 5 is a cross-sectional view of the dynamic damper 1 cut radially along line B-B in FIG. 3, and FIG. 6 is an exploded perspective view of the dynamic damper 1.

[0021] Here, as shown in FIG. 4, the dynamic damper 1 is attached to the lower side of the coil spring 6 and to the shock absorber 7, and basically includes a cylindrical body 10, a first spring 11, a second spring 12, and a movable mass 13 that is sandwiched between the first spring 11 and the second spring 12 and is supported so as to be vibratable within the cylindrical body 10.

[0022] In addition, an upper lid 21 is attached to the upper end of the cylindrical body 10 in contact with the upper end of the first spring 11 and for accommodating the first spring 11 within the cylindrical body 10 in a state of pressing the first spring 11 from above. Further, near the center inside the upper lid 21, an upper buffer member 22 that restricts movement by coming into contact with the movable mass 13 when the movable mass 13 moves toward the upper lid 21 side is fixed. Note that the upper buffer member 22 is formed of a flexible material (for example, a resin material) and also has the effect of alleviating the impact when contacting. Also, as shown in FIG. 6, a bearing 23, a bearing guide shim 24, a spring guide 25, etc. are further arranged between the upper lid 21 and the first spring 11.

[0023] On one side, a lower lid 26 is attached to the lower end of the cylinder 10. The lower lid 26 is in contact with the lower end of the second spring 12 and is accommodated in the cylinder 10 while pressing the second spring 12 from below. Further, near the center inside the lower lid 26, a lower buffer member 27 is fixed. When the movable mass 13 moves toward the lower lid 26 side, the lower buffer member 27 comes into contact with the movable mass 13 to limit the movement. The lower buffer member 27 is formed of a flexible material (for example, a resin material) like the upper buffer member 22 and also has the effect of reducing the impact when contacting. Also, as shown in FIG. 6, a bearing 28, a bearing guide shim 29, a spring guide 30, etc. are further arranged between the lower lid 26 and the second spring 12. In the above example, the lower lid 26 is separate from the cylinder 10, but they may be integrally formed into a bag shape.

[0024] The movable mass 13 has a cylindrical shape and is a mass body in the dynamic damper 1. By vibrating the movable mass 13 in the cylinder 10, the vibration energy of the spring lower member is absorbed to attenuate the vibration. The movable mass 13 is formed of a high-density metal body such as a tungsten alloy. Regarding its weight and shape, as will be described later, it is designed to attenuate the resonance frequency of the spring lower member and the vibrations around it. Also, a through hole serving as a passage for air is formed near the center in the axial direction of the movable mass 13.

[0025] Also, as shown in FIGS. 4 and 6, at the locations where the movable mass 13 inside the cylinder body 10 comes into contact, a first guide member 31 and a second guide member 32 for guiding the movement of the movable mass 13 are arranged. The first guide member 31 and the second guide member 32 have a shape in which a cylinder is divided into a plurality (for example, two) along the axial direction (the vertical direction in FIG. 4), and the first guide member 31 and the second guide member 32 are arranged overlapping each other in the axial direction. Further, the movable mass 13 is slidable in the axial direction in a state where the movable mass 13 is in contact with the inner surfaces of the first guide member 31 and the second guide member 32. Note that the materials of the first guide member 31 and the second guide member 32 can be appropriately selected, but it is desirable to select a material that can prevent wear as much as possible. Further, a plurality of convex portions are formed on the outer peripheral surfaces of the first guide member 31 and the second guide member 32, and by forming concave portions corresponding to these convex portions on the inner surface of the cylinder body 10, the first guide member 31 and the second guide member 32 are positioned and fixed with respect to the cylinder body 10.

[0026] Also, inside the first guide member 31 and the second guide member 32, particularly with respect to the first guide member 31, as shown in FIG. 5, it also functions as a pressing member that presses the movable mass 13 from a direction intersecting the vibration direction by the action of a screw nut 41 described later. On the other hand, with respect to the second guide member 32, it serves as a receiving member that receives the movable mass 13 pressed by the first guide member 31 on the opposite side, preventing the load from concentrating on a specific portion of the pressed movable mass 13 and having a function of dispersing the load over the entire movable mass 13. Further, in the first embodiment, by dividing the first guide member 31 and the second guide member 32 without integrating them, it is possible to prevent the guide member from being deformed by the load from the movable mass 13. Note that in the first embodiment, the guide member is divided into two, the first guide member 31 and the second guide member 32, but it may be divided into three or more.

[0027] On one hand, a screw hole 42 into which a screw bolt (holding member) 41 can be inserted is formed at one location on the side surface of the cylindrical body 10 (the front side in FIG. 3, the right side surface in FIG. 4, and the upper side surface in FIG. 5). Further, as shown in FIGS. 4 and 5, the screw hole 42 communicates from the cylindrical body 10 to the first guide member 31 located in the lower layer of the cylindrical body 10, and the bottom surface of the screw hole 42 is formed on the upper surface of the first guide member 31. And inside the screw hole 42 communicating from the cylindrical body 10 to the first guide member 31, one or a plurality of disc springs 43 and a shim 44 are arranged so as to sandwich the disc springs 43, and they are tightened with the screw bolt 41 from above. That is, the screw hole 42 also corresponds to a housing hole for housing the disc spring. Incidentally, by changing the thickness of the shim 44, it is also possible to change the load setting by changing the mounting height of the disc spring 43.

[0028] The screw bolt 41 can be moved in the direction of the rotation axis by rotating. When the screw bolt 41 is inserted into the screw hole 42 and the screw bolt 41 is rotated to move the screw bolt 41 to the bottom surface side, the disc spring 43 is compressed in the screw hole 42 by the screw bolt 41, and a load is generated on the bottom surface of the screw hole 42. As a result, pressing from the first guide member 31 to the movable mass 13 occurs. Since the current position of the screw bolt 41 is held unless it is rotated, it can be held in a state where the first guide member 31 is pressed toward the movable mass 13 (a state where a constant load is generated on the movable mass 13).

[0029] Also, since the screw bolt 41 can adjust the position in the rotation axis direction by rotating, it is possible to adjust the load for pressing the movable mass 13 via the first guide member 31 by rotating the screw bolt 41. That is, if the screw bolt 41 is tightened more strongly, the load for pressing the movable mass 13 becomes larger. On the other hand, if the screw bolt 41 is loosened, the load for pressing the movable mass 13 becomes smaller.

[0030] As a method for adjusting the load applied to the movable mass 13, in addition to the method of adjusting the tightening amount of the screw nut 41 as described above, for example, it is also possible to change the number of disc springs 43 or change the spring constant. That is, if the number of disc springs 43 is increased or the spring constant is changed to a larger one, the load applied to the movable mass 13 will be greater even if the tightening amount of the screw nut 41 remains unchanged. On the other hand, if the number of disc springs 43 is decreased or the spring constant is changed to a smaller one, the load applied to the movable mass 13 will be smaller even if the tightening amount of the screw nut 41 remains unchanged. Also, in addition to the disc spring, a coil spring, a leaf spring, etc. may be used for pressing.

[0031] And in the suspension 5 provided with the dynamic damper 1 having the above configuration, as described above, by adjusting the tightening amount of the screw nut 41, increasing or decreasing the number of disc springs 43, or replacing the disc spring 43, the load applied by the first guide member 31 to the movable mass 13 can be adjusted. Since the load applied by the first guide member 31 to the movable mass 13 corresponds to the resistance (friction) that hinders the vertical movement of the movable mass 13 within the cylinder 10, that is, it becomes possible to adjust the damping force of the dynamic damper 1. Specifically, the greater the load applied by the first guide member 31 to the movable mass 13, the greater the resistance (friction) that hinders the vertical movement of the movable mass 13 within the cylinder 10 (the more difficult it is for the movable mass 13 to move). Conversely, the smaller the load applied by the first guide member 31 to the movable mass 13, the smaller the resistance (friction) that hinders the vertical movement of the movable mass 13 within the cylinder 10 (the easier it is for the movable mass 13 to move).

[0032] Here, as the load pressing the movable mass 13 decreases, that is, as the movable mass 13 becomes easier to move, basically the damping force of the dynamic damper 1 decreases. Conversely, as the load pressing the movable mass 13 increases, that is, as the movable mass 13 becomes more difficult to move, basically the damping force of the dynamic damper 1 increases. However, even if the damping force is large, the vibration damping effect is not necessarily high. As will be described later, even if vibration can be reduced only at a specific frequency, conversely, the vibration damping performance at surrounding frequencies may deteriorate. Therefore, it is necessary to adjust the damping force of the dynamic damper 1 (that is, the load pressing the movable mass 13) to an appropriate value while considering these measurement results.

[0033] And, FIG. 7 shows the results of simulating the vibration levels of the lower spring member and the upper spring member that occur during running after determining the values for each parameter regarding the suspension 5 including the damping force of the dynamic damper 1. Incidentally, the results when the dynamic damper 1 is not installed are also shown as a comparative example.

[0034] As shown in FIG. 7, in the measurement results of a vehicle equipped with the dynamic damper 1 in which each value is set so as to attenuate the resonance frequency of the lower spring member and the vibrations around it, it can be seen that the vibration level of the lower spring member is lower in the resonance frequency of the lower spring member and the surrounding area A compared with the case where the dynamic damper 1 is not provided. Incidentally, it can be seen that as the vibration of the lower spring member decreases, the vibration level of the upper spring member also decreases accordingly.

[0035] Further, FIG. 8 also shows the results of simulating the vibration levels of the lower spring member and the upper spring member that occur during running when the dynamic damper 1 is provided as a comparative example and the load pressing the movable mass 13 is 0 [N]. Referring to FIG. 8 here, it can be seen that if the load pressing the movable mass 13 is too large, the vibration damping effect disappears, but conversely, if it is too small, vibration damping is pinpointed only at the resonance frequency of the lower spring member, and conversely, the vibration damping performance deteriorates overall. For example, in FIG. 8, at the resonance frequency, the vibration levels of the lower spring member and the upper spring member are greatly reduced compared to the case where the dynamic damper 1 is not provided, but it can be seen that before and after that, conversely, the vibration levels of the lower spring member and the upper spring member are larger than in the case where the dynamic damper 1 is not provided. That is, when adjusting the damping force of the dynamic damper 1, the damping force of the dynamic damper 1 does not necessarily have to be large. In order to improve the riding comfort, it is necessary to confirm the overall vibration damping effect including the vicinity of the resonance frequency of the lower spring member and search for and set a more appropriate value.

[0036] As described in detail above, the dynamic damper 1 according to the first embodiment is provided in the suspension 5 interposed between the upper spring member and the lower spring member in the vehicle, and is a dynamic damper that suppresses the vibration of the lower spring member and whose damping force for suppressing vibration can be varied. In particular, it has a cylindrical body 10, a movable mass 13 sandwiched between a first spring 11 and a second spring 12 and supported so as to be vibrationally movable within the cylindrical body 10, and a first guide member 31 as a pressing member that presses the movable mass 13 from a direction intersecting the vibration direction, and the damping force can be varied by adjusting the load pressing from the pressing member to the movable mass 13. As a result, the damping force can be varied with a simple structure of pressing the movable mass 13 that vibrates within the cylindrical body 10. Therefore, it is possible to easily adjust the damping force according to the lower spring member that is the object of damping vibration, and by adjusting the damping force, a high vibration suppression effect can be expected for the vibration at the resonance frequency of the lower spring member and the frequencies around it. Further, on the side surface of the cylinder body 10, there is a screw nut 41 as a holding member for holding the first guide member 31, which is a pressing member, in a state of being pressed toward the movable mass 13. By adjusting the position of the screw nut 41 on the side surface of the cylinder body 10, the load applied to press the movable mass 13 from the first guide member 31 is adjusted. Therefore, it is possible to easily adjust the load applied to press the movable mass 13 only by adjusting the position of the screw nut 41. Further, the holding member is a screw nut 41 that can move in the direction of the rotation axis by rotating. A screw hole 42 into which the screw nut 41 can be inserted is formed on the side surface of the cylinder body 10. By inserting the screw nut 41 into the screw hole 42 and rotating the screw nut 41, the load applied to press the movable mass 13 from the screw nut 41 via the first guide member 31 is adjusted. Therefore, it is possible to easily adjust the load applied to press the movable mass 13, that is, the damping force of the dynamic damper 1, particularly by the tightening degree of the screw nut 41 on the side surface of the cylinder body 10. Also, there are a first guide member 31 and a second guide member 32 that are arranged at a position where they contact the movable mass 13 inside the cylinder body 10 and guide the movement of the movable mass 13. The first guide member 31 and the second guide member 32 are arranged overlapping in the axial direction, and the first guide member 31 functions as a pressing member that presses the movable mass 13. Therefore, when the movable mass 13 is pressed, it is possible to prevent the load from concentrating on a specific portion of the pressed movable mass 13 and disperse the load over the entire movable mass 13. Further, by dividing the guide member, it is possible to prevent the guide member from deforming due to the load from the movable mass 13.

[0037] [Second Embodiment] Next, the dynamic damper according to the second embodiment will be described with reference to FIG. 9. In the following description, the same reference numerals as those of the configuration of the dynamic damper 1 according to the first embodiment in FIGS. 1 to 8 indicate the same or corresponding parts as the configuration of the dynamic damper 1 and the like according to the first embodiment.

[0038] The schematic configuration of the dynamic damper according to this second embodiment is substantially the same as that of the dynamic damper 1 according to the first embodiment. However, the dynamic damper 1 according to the first embodiment has only one accommodation hole (screw hole 42) for accommodating the disc spring on the side surface of the cylindrical body 10, whereas the dynamic damper according to the second embodiment has a plurality of accommodation holes for accommodating the disc spring on the side surface of the cylindrical body 10. Further, in the dynamic damper 1 according to the first embodiment, the disc spring is held by the screw screw 41 inserted into the screw hole 42, whereas in the second embodiment, the disc spring is held by covering the accommodation hole with a lid and fixing the lid with a screw screw.

[0039] The schematic configuration of the dynamic damper 100 according to the second embodiment will be described below with reference to FIG. 9. FIG. 9 is a cross-sectional view of the dynamic damper 100 according to the second embodiment, and in particular, is a cross-sectional view corresponding to FIG. 4 of the dynamic damper 1 according to the first embodiment.

[0040] As shown in FIG. 9, a plurality of accommodation holes 101 for accommodating the disc spring are formed at a plurality of locations on the side surface of the cylindrical body 10 (the right side surface side in FIG. 9). Further, a lid portion 102 for covering the opening of the accommodation hole 101 is removably fixed to the cylindrical body 10 with a screw screw 103. In the example shown in FIG. 9, the number of accommodation holes 101 is five, but it is not necessarily five, and it may be four or less, or six or more. Also, in the example shown in FIG. 9, the plurality of accommodation holes 101 are arranged along the axial direction, but they may be arranged along the circumferential direction as long as they are in a position where the first guide member 31 can be pressed by the biasing force of the accommodated disc spring.

[0041] In addition, in FIG. 9, the disc springs and shims housed in the respective housing holes 101 are omitted because they have the same form as the disc spring 43 and the shim 44 in FIG. 5. However, inside each housing hole 101 that communicates from the cylindrical body 10 to the first guide member 31, disc springs are arranged so as to be sandwiched between two shims. With the disc springs housed, the housing hole 101 is closed from above by the lid portion 102. As a result, the first guide member 31 can be pressed by the biasing force of the housed disc springs. However, in the dynamic damper 100 of the second embodiment, it is not always necessary to house disc springs in all the housing holes 101, and it is also possible to house disc springs in only some of the housing holes 101.

[0042] According to the dynamic damper 100 having the above configuration, as a method of adjusting the load applied to the movable mass 13, in addition to changing the number of disc springs or changing the spring constant, it is also possible to adjust by changing the number of housing holes 101 that are the objects for housing the disc springs. As a result, compared with the dynamic damper 1 of the first embodiment, it is possible to adjust the load applied to the movable mass 13, that is, the damping force of the dynamic damper 100, over a wider range. Also, in addition to the disc springs, the movable mass 13 may be pressed by housing a coil spring, a leaf spring, or the like in the housing hole 101.

[0043] Note that the present invention is not limited to the above-described embodiments, and it goes without saying that various improvements and modifications are possible without departing from the gist of the present invention. For example, in the first and second embodiments, the dynamic damper 1 is attached below the spring with respect to the coil spring 6 and to the shock absorber 7, but the attachment position of the dynamic damper 1 is not limited to the above position, and it can be attached to each member to be damped.

[0044] Also, in the first and second embodiments, the dynamic damper 1 is described as a part of the suspension 5, but it may be provided independently of the suspension 5 as long as it can suppress the vibration of the spring lower member.

[0045] In addition, in the first and second embodiments, it is assumed that a total of four suspensions 5 corresponding to the front, rear, left, and right wheels each include a dynamic damper 1. However, it is not necessarily required that all the suspensions 5 include a dynamic damper 1, and only some of the suspensions 5 may include it.

[0046] Also, in the first and second embodiments, the movable mass 13 is sandwiched between the first spring 11 and the second spring 12 and supported so as to be vibratable in the vertical direction. However, it may be supported by only one of the first spring 11 or the second spring 12. Even if it is supported by only one spring, the movable mass 13 can vibrate in the vertical direction due to the elasticity of the spring. Therefore, the dynamic damper 1 has a function of attenuating vibration. Further, an elastic body other than a spring may be used.

Explanation of Reference Numerals

[0047] 1... Dynamic damper, 2... Vehicle, 3... Wheel, 4... Vehicle body, 5... Suspension, 6... Coil spring, 7... Shock absorber, 10... Cylinder body, 11... First spring (elastic body), 12... Second spring (elastic body), 13... Movable mass, 31... First guide member (pressing member), 32... Second guide member, 41... Screw nut (holding member)

Claims

1. A dynamic damper disposed in a suspension device interposed between an upper spring member and a lower spring member in a vehicle, comprising: a cylinder; a movable mass supported by an elastic body so as to be vibratable within the cylinder; a pressing member that presses the movable mass from a direction intersecting the vibration direction; and a holding member that holds the pressing member and adjusts a load for pressing from the pressing member to the movable mass.

2. The holding member holds the pressing member in a state of pressing the pressing member from the side surface of the cylinder toward the movable mass side, and The dynamic damper according to claim 1, wherein the load for pressing from the pressing member to the movable mass is adjusted by adjusting the position of the holding member on the side surface of the cylinder.

3. The holding member is a screw thread that is movable in the rotation axis direction by rotating, and A screw hole into which the screw thread can be inserted is formed in the side surface of the cylinder. The screw thread is inserted into the screw hole, and the load for pressing from the screw thread to the movable mass through the pressing member is adjusted by rotating the screw thread. The dynamic damper according to claim 2.

4. A plurality of guide members are disposed at a location where the movable mass inside the cylinder comes into contact with the movable mass to guide the movement of the movable mass, and The plurality of guide members are arranged to overlap in the axial direction, and a part of them serves as the pressing member. The dynamic damper according to any one of claims 1 to 3.

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