Patent Publication Number: US-2019186578-A1

Title: Damper device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2017-240676 filed on Dec. 15, 2017, the contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a damper device that is provided on a vibration part of a transport apparatus (for example, vehicle, airplane, and ship) in which vibration, oscillation, or the like easily occurs, and that suppresses the vibration of the vibration part. 
     Description of the Related Art 
     An object of a damper device according to Japanese Laid-Open Patent Publication No. 2008-296732 is to enhance the strength of a vibration isolating body that performs, as a viscoelastic body, the function of absorbing vibration. 
     To achieve the above object, the damper device according to Japanese Laid-Open Patent Publication No. 2008-296732 includes a support base including side walls that face each other, and a vibration isolating body having a weight embedded in polymer gel and which performs, as a viscoelastic body, the function of absorbing vibration. The vibration isolating body is held between the side walls of the support base, and an inner surface of each side wall and an outer surface of the polymer gel of the vibration isolating body that faces the inner surface of the side wall are in contact with each other. 
     An object of a damper device according to Japanese Laid-Open Patent Publication No. 2011-117555 is to provide a spring that can reduce the amplitude of a target object even in a low frequency band. 
     To achieve the above object, the damper device according to Japanese Laid-Open Patent Publication No. 2011-117555 has an elastic characteristic, and a spring is formed in a closed space filled with a liquid. The closed space includes a hole that communicates between the inside and the outside of the closed space. The liquid can pass through the hole. 
     SUMMARY OF THE INVENTION 
     In Japanese Laid-Open Patent Publication No. 2008-296732, the weight is fixed on a partition plate through a support member in the polymer gel filling a forming chamber. In Japanese Laid-Open Patent Publication No. 2011-117555, the target object is fixed on a base through the spring in the liquid filling a container. 
     That is to say, one of the conventional methods for providing a dynamic damper with a damping characteristic is to change the characteristic of the support member or the spring. 
     However, since variation of the damping characteristic is large due to the nature of the support member or the spring, it is difficult to control the damping characteristic. 
     The present invention has been made in order to solve the above problem, and an object is to provide a damper device in which the durability and a vibration reduction effect due to damping (viscous damping of oil) can be improved, and the damping characteristic can be adjusted easily. 
     [1] A damper device according to an aspect of the present invention includes: a case that is filled with oil; a weight that is stored in the case and includes a through hole; a guide rod that is inserted into the through hole of the weight and configured to allow the weight to slide in the oil; and at least one flow passage that is formed in the weight and through which the oil flows. 
     Thus, a vibration reduction effect can be improved due to damping (viscous damping of oil). When a conventional rubber with an improved damping characteristic is used, the rubber becomes soft so that the durability of the rubber deteriorates. On the other hand, in a case of oil-type damper device, even if the damping characteristic is improved, the oil-type damper device is less likely to deteriorate, and thus the durability is improved. By providing a flow passage or closing the flow passage, the damping characteristic can be adjusted easily. 
     [2] The damper device in the aspect of the present invention may further include a unit configured to close the at least one flow passage formed in the weight. Thus, by appropriately closing the flow passage formed in the weight, the damping characteristic can be adjusted. 
     [3] In the aspect of the present invention, the unit configured to close the flow passage may include a screw hole formed in the flow passage. By screwing a bolt or the like into the screw hole or detaching the bolt or the like from the screw hole, it is possible to open or close the flow passage. Therefore, the damping characteristic can be adjusted easily in accordance with a target object whose vibration should be suppressed, a condition of use, or the like. The viscosity of the oil, that is, the kind of the oil can be changed. 
     [4] The damper device in the aspect of the present invention may further include: one support part configured to slidably support one end part of the weight; and the other support part configured to slidably support the other end part of the weight. 
     The weight that is stored in the case containing the oil slides in a left-right direction, for example, along the guide rod that is inserted into the through hole of the weight, due to the vibration. In this case, the one support part slidably supports one end part of the weight and the other support part slidably supports the other end part of the weight. Therefore, the weight can stably slide in the oil without a backlash. 
     The damper device according to the present invention includes a vibration attenuation element by contact friction between a spring and a plate member, and a spring element by the spring. Moreover, the vibration attenuation characteristic hardly varies even when an angle of the target object whose vibration should be suppressed changes in a front-rear direction. 
     The above and other objects features and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating a seat device (mainly, frame structure) that includes a damper device according to the present embodiment; 
         FIG. 2A  is a front view illustrating the damper device; 
         FIG. 2B  is a side view illustrating the damper device; 
         FIG. 3A  is a front view of the damper device from which a lid body is detached; 
         FIG. 3B  is a cross-sectional view taken along line IIIB-IIIB in  FIG. 3A ; 
         FIG. 4  is a cross-sectional view taken along line IV-IV in  FIG. 3B ; 
         FIG. 5  is an explanatory view showing a hammering test for a single seat back frame; 
         FIG. 6A  is a front view illustrating a damper device according to a comparative example; 
         FIG. 6B  is a side view illustrating the damper device according to the comparative example; 
         FIG. 7  is a graph showing inertance characteristics of the single seat back frame, the damper device according to the comparative example, and the damper device according to an example of the embodiment; and 
         FIG. 8  is a front view of the damper device according to a modification from which a lid body is detached. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Description is hereinafter given of an embodiment of a damper device according to the present invention with reference to  FIG. 1  to  FIG. 8 . 
     For example, as illustrated in  FIG. 1 , a damper device  10  according to the present embodiment is installed on a seat device  12 . 
     The seat device  12  includes at least a seat cushion frame  14  and a seat back frame  16 . The seat back frame  16  includes a lower seat back frame  18 L that is rotatably attached to the seat cushion frame  14 , and an upper seat back frame  18 U that is fixed to an upper part of the lower seat back frame  18 L. 
     The seat device  12  is provided so as to be slidable in, for example, a front-rear direction by brackets  20  (not shown) that are provided on a floor or the like of a transport apparatus such as a vehicle, a ship, or an airplane. Needless to say, the seat device  12  may be fixed to the floor or the like without sliding. 
     The seat cushion frame  14  includes a pair of left and right cushion side frames  22  that extends to the front-rear direction, a front frame  24  that is extended between front parts of the cushion side frames  22 , a rear frame  26  that is extended between rear parts of the cushion side frames  22 , and the like. Thus, the seat cushion frame  14  has a frame shape. The bracket  20  is attached to each cushion side frame  22 . 
     The lower seat back frame  18 L includes a pair of left and right back side frames  30  that extends in an approximately up-down direction, a back lower frame  32  that is extended between lower ends of the left and right back side frames  30 , and reinforcement poles  34  that are extended respectively between upper parts of the back side frames  30  and between central parts of the back side frames  30 . Thus, the lower seat back frame  18 L has a frame shape. The back lower frame  32  is connected to the lower parts of the back side frames  30  by welding, for example. 
     The upper seat back frame  18 U has an inverted U-letter shape. Each end of the upper seat back frame  18 U is connected to the upper part of the lower seat back frame  18 L by welding, for example. The upper seat back frame  18 U has two tubular holders  36  fixed on a central part thereof, through which stays of a headrest are inserted. 
     Note that a rear part of the seat cushion frame  14  and a lower part of the lower seat back frame  18 L are provided with a support shaft  38  that supports the lower seat back frame  18 L in a manner that the lower seat back frame  18 L is rotatable with respect to the seat cushion frame  14 . For example, the lower part of the lower seat back frame  18 L is rotatably connected to an inner side of the rear part of the cushion side frame  22 . 
     Then, as described above, the damper device  10  according to the present embodiment is installed on the seat device  12 . The damper device  10  may be provided to any part of the seat device  12 . However, in order to suppress vibration of the seat back frame  16 , for example, it is preferable that the damper device  10  is disposed on the seat back frame  16 . In the present embodiment, the damper device  10  is provided on a central part of the seat back frame  16  or the central part of the upper seat back frame  18 U so that the damper device  10  is extended between central parts of the reinforcement poles  34 , for example. 
     As illustrated in  FIG. 2A  to  FIG. 4 , the damper device  10  includes a case  50 , and a weight  52  that is slidably attached in the case  50 . 
     The case  50  includes a box body  54  (see  FIG. 2B ) and a lid body  56  (see  FIG. 2B ) that are made of metal through a sheet metal working of a metal plate, for example. The box body  54  has an opening on one side thereof, and contains a storage space  58  for storing the weight  52 . The lid body  56  covers the opening of the box body  54 . The storage space  58  is filled with oil  60 . 
     The weight  52  has a shape that can be stored in the storage space  58  and is slidable in the case  50  in one direction, for example, a left-right direction.  FIG. 2A  and  FIG. 3A  show an example in which the weight  52  has a rectangular parallelepiped shape. In the left-right direction, the length of the weight  52  is shorter than the length of the case  50  on the inside. In addition, the weight  52  includes at least one through hole that penetrates along one direction (for example, left-right direction) from one side surface to the other side surface. In an example in  FIG. 4 , the weight  52  includes a central through hole  62  that penetrates an approximately central part of the weight  52 . 
     On the other hand, the box body  54  includes a central guide rod  64  that is inserted into the central through hole  62  of the weight  52 , and a right fixing part  66 R and a left fixing part  66 L that fix the central guide rod  64  to side walls of the case  50 . 
     The right fixing part  66 R includes a right through hole  70 R which is a screw hole formed in a central part of a right side wall  68 R of the box body  54 , a right bolt member  72 R that is screwed into the right through hole  70 R, and a right central spring  76 R into which a right side of the central guide rod  64  is inserted and which is disposed between a right side surface  74 R of the weight  52  and a right bolt member  72 R. A central part of an end part of the right bolt member  72 R is provided with a right concave part  78 R into which a right end of the central guide rod  64  is inserted, for example. Needless to say, the central part of the end part of the right bolt member  72 R may be flat without the right concave part  78 R. 
     The left fixing part  66 L includes a left through hole  70 L which is a screw hole formed in a central part of a left side wall  68 L of the box body  54 , a left bolt member  72 L that is screwed into the left through hole  70 L, and a left central spring  76 L into which a left side of the central guide rod  64  is inserted and which is disposed between a left side surface  74 L of the weight  52  and a left bolt member  72 L. A central part of an end part of the left bolt member  72 L is provided with a left concave part  78 L into which a left end of the central guide rod  64  is inserted, for example. Needless to say, the central part of the end part of the left bolt member  72 L may be flat without the left concave part  78 L. 
     When the right central spring  76 R is detached or replaced with another spring, the right central spring  76 R can be easily detached or replaced with another spring by loosening and detaching the right bolt member  72 R, without the need to detach the lid body  56 . The same applies to the left central spring  76 L. 
     In addition, the damper device  10  includes a first support part  80 A for slidably supporting one end part of the weight  52  (for example, upper part), and a second support part  80 B for slidably supporting the other end part of the weight  52  (for example, lower part). 
     The first support part  80 A includes a first through hole  81 A that is formed in the upper part of the weight  52  in parallel with the central through hole  62 , a first cutout portion  82 A that is formed on the right side surface  74 R of the weight  52 , a first slide bearing  84 A that is fixedly disposed on the first cutout portion  82 A using a screw or the like, a second cutout portion  82 B that is formed on the left side surface  74 L of the weight  52 , and a second slide bearing  84 B that is fixedly disposed on the second cutout portion  82 B using the screw or the like. The first support part  80 A further includes: a first support rod  88 A that is slidable in the left-right direction in the first through hole  81 A, a through hole  86 A of the first slide bearing  84 A, and a through hole  86 B of the second slide bearing  84 B as described above; a first concave part  92 A into which one end part of the first support rod  88 A is inserted; and a second concave part  92 B into which the other end part of the first support rod  88 A is inserted. The first concave part  92 A and the second concave part  92 B are formed on inner surfaces of an upper part of the case  50 . 
     The second support part  80 B includes a second through hole  81 B that is formed in the lower part of the weight  52  in parallel with the central through hole  62 , a third cutout portion  82 C that is formed on the right side surface  74 R of the weight  52 , a third slide bearing  84 C that is fixedly disposed on the third cutout portion  82 C using the screw or the like, a fourth cutout portion  82 D that is formed on the left side surface  74 L of the weight  52 , and a fourth slide bearing  84 D that is fixedly disposed on the fourth cutout portion  82 D using the screw or the like. The second support part  80 B further includes: a second support rod  88 B that is slidable in the left-right direction in the second through hole  81 B, a through hole  86 C of the third slide bearing  84 C, and a through hole  86 D of the fourth slide bearing  84 D as described above; a third concave part  92 C into which one end part of the second support rod  88 B is inserted; and a fourth concave part  92 D into which the other end part of the second support rod  88 B is inserted. The third concave part  92 C and the fourth concave part  92 D are formed on inner surfaces of a lower part of the case  50 . 
     The weight  52  of the damper device  10  further includes one or more flow passages in addition to the above central through hole  62 . The one or more flow passages penetrate through the weight  52  from the right side surface  74 R to the left side surface  74 L. In an example in  FIG. 3B , six flow passages (first flow passage FP 1  to sixth flow passage FP 6 ) are formed near the central through hole  62 , four flow passages (seventh flow passage FP 7  to tenth flow passage FP 10 ) are formed near the first slide bearing  84 A, and four flow passages (eleventh flow passage FP 11  to fourteenth flow passage FP 14 ) are formed near the third slide bearing  84 C. Of the first flow passage FP 1  to the fourteenth flow passage FP 14 , the first flow passage FP 1  to the fourth flow passage FP 4 , the seventh flow passage FP 7 , the tenth flow passage FP 10 , the eleventh flow passage FP 11 , and the fourteenth flow passage FP 14  have larger diameter than the other flow passages. 
     Each of the first flow passage FP 1  to the fourteenth flow passage FP 14  includes a screw hole  93  into which a bolt or a screw (neither are shown) is screwed. For example, when the bolt is screwed into the screw hole  93  of the first flow passage FP 1 , the first flow passage FP 1  is closed, and when the bolt is detached, the first flow passage FP 1  is opened. The same applies to the other flow passages. 
     As described above, by controlling opening/closing of the first flow passage FP 1  to the fourteenth flow passage FP 14 , the moving resistance of the weight  52  in the oil  60  changes. That is to say, the transport apparatus in which the seat device  12  is disposed can have different vibration characteristics depending on a type or kind of the transport apparatus; however, by adjusting the moving resistance of the weight  52  in accordance with each different vibration characteristic, the damper device  10  has an excellent versatility. 
     Note that in the first flow passage FP 1  to the fourteenth flow passage FP 14 , the screw hole  93  may be formed only at an entrance part or in the entire flow passage. If the screw hole  93  is formed in the entire flow passage, the screw hole  93  itself functions as an element that increases the moving resistance of the weight  52 . 
     The weight  52  may have a rough surface. Also in this case, the rough surface itself of the weight  52  functions as an element that enhances the moving resistance of the weight  52 . 
     Here, description is given concerning an exemplified method of disposing the weight  52  in the case  50 . Through holes (not shown) are formed at respective portions of side walls of the case  50  where the first support rod  88 A and the second support rod  88 B are arranged. The weight  52  is stored in the storage space  58  of the box body  54 . After that, the first support rod  88 A and the second support rod  88 B are inserted into the through holes formed in the side walls of the case  50 . The first support rod  88 A is inserted into the first through hole  81 A of the weight  52 , and the second support rod  88 B is inserted into the second through hole  81 B of the weight  52 . In this case, the first support rod  88 A is also inserted into the through hole  86 A of the first slide bearing  84 A and the through hole  86 B of the second slide bearing  84 B, and the second support rod  88 B is also inserted into the through hole  86 C of the third slide bearing  84 C and the through hole  86 D of the fourth slide bearing  84 D. 
     The through holes of the side walls of the case  50  into which the first support rod  88 A and the second support rod  88 B are inserted are closed by welding, for example. In this case, on the inner surfaces of the upper part of the case  50 , the first concave part  92 A and the second concave part  92 B into which one end part and the other end part of the first support rod  88 A are inserted are formed, and the third concave part  92 C and the fourth concave part  92 D into which one end part and the other end part of the second support rod  88 B are inserted are formed. Thus, the weight  52  is stored in the box body  54 . 
     After that, for example, the central guide rod  64  is inserted to penetrate from the right through hole  70 R of the right fixing part  66 R to the left through hole  70 L of the left fixing part  66 L. Then, the right central spring  76 R is externally inserted around a right end part of the central guide rod  64 , and the left central spring  76 L is externally inserted around a left end part of the central guide rod  64 . After that, the right bolt member  72 R is screwed into the right through hole  70 R, and the left bolt member  72 L is screwed into the left through hole  70 L. 
     After that, the storage space  58  of the box body  54  is filled with the oil  60 , and the lid body  56  is attached to the box body  54  so that the lid body  56  covers the opening of the box body  54  liquid-tightly. Thus, the damper device  10  is formed. 
     Here, an experiment example regarding the damper device  10  will be described with reference to  FIGS. 5 to 7 . First, as illustrated in  FIG. 5 , a hammering test for the single seat back frame  16  (made of iron) was performed. In the hammering test, at the central part of the seat back frame  16 , for example, at the central part of the upper reinforcement pole  34 , a G meter  94  was fixed. Then, a portion of one back side frame  30  at the same height as the position to which the G meter  94  was fixed was hit with a hammer  96 . This result (inertance characteristic) is expressed by a curved line La in  FIG. 7 . The inertance has a peak at a particular frequency. This particular frequency is hereinafter referred to as a peak frequency fp. 
     Next, a damper device  100  according to a comparative example was prepared. As illustrated in  FIG. 6A  and  FIG. 6B , the damper device  100  according to the comparative example includes a case  102 , and a weight  104  that is elastically held at a central part of the case  102 . 
     The case  102  is formed so as to integrate an upper plate  106   a,  a lower plate  106   b,  and a back plate  106   c  that are made of metal, by performing a sheet metal working of a metal plate, for example. In this case, the upper plate  106   a  projects forward from an upper end of the back plate  106   c,  and the lower plate  106   b  projects forward from a lower end of the back plate  106   c.  That is to say, the upper plate  106   a  and the lower plate  106   b  face each other. 
     A semicircular upper attachment plate  108   a  that is made of metal, for example, is formed integrally at a front end of the upper plate  106   a.  Similarly, a semicircular lower attachment plate  108   b  that is made of metal, for example, is also formed integrally at a front end of the lower plate  106   b.  Each of the upper attachment plate  108   a  and the lower attachment plate  108   b  has a screw hole  110  formed in a central part thereof. 
     The upper plate  106   a  of the case  102  and an upper surface  112   a  of the weight  104  are connected to each other through two plate-shaped first elastic members  114 . Similarly, the lower plate  106   b  of the case  102  and a lower surface  112   b  of the weight  104  are connected to each other through two first elastic members  114 . Each first elastic member  114  has a plate shape, and is arranged so that a thickness direction of the first elastic member  114  coincides with the left-right direction of the case  102 , and a surface direction of the first elastic member  114  coincides with the front-rear direction of the case  102 . 
     Next, although not shown, the damper device  100  according to the comparative example and the G meter  94  were fixed to the central part of the seat back frame  16 . Then, the hammering test was performed similarly to the above example. This result (inertance characteristic) is expressed by a curved line Lb in  FIG. 7 . 
     In the inertance characteristic of the seat back frame  16  with the damper device  100  according to the comparative example, the inertance has a local minimum value at the peak frequency fp of the single seat back frame  16 ; however, the inertance has high peak values Pa and Pb around the peak frequency fp. 
     Next, the damper device  10  according to the embodiment and the G meter  94  were fixed to the central part of the seat back frame  16  similarly to the above comparative example. Then, the hammering test was performed similarly to the above. This result (inertance characteristic) is expressed by a curved line Lc in  FIG. 7 . 
     In the inertance characteristic of the seat back frame  16  with the damper device  10  according to the embodiment, the inertance has a local minimum value at the peak frequency fp of the single seat back frame  16 ; moreover, peak values Pc and Pd around the peak frequency fp are lower than those of the comparative example. 
     As a result, the damper device  10  according to the embodiment has an improved vibration reduction effect due to the viscous damping of the oil  60 , as compared to the comparative example. 
     As described above, the damper device  10  according to the present embodiment includes: the case  50  that is filled with the oil  60 ; the weight  52  that is stored in the case  50  and includes the central through hole  62 ; the central guide rod  64  that is inserted into the central through hole  62  of the weight  52  and configured to allow the weight  52  to slide in the oil  60 ; and at least one flow passage that is formed in the weight  52  and through which the oil  60  flows. 
     Thus, the vibration reduction effect can be improved due to damping (viscous damping of oil). When a conventional rubber with an improved damping characteristic is used, the rubber becomes soft so that the durability of the rubber deteriorates. On the other hand, in the case of oil-type damper device, even if the damping characteristic is improved, the oil-type damper device is less likely to deteriorate, and thus the durability is improved. By providing a flow passage or closing the flow passage, the damping characteristic can be adjusted easily. 
     The damper device  10  according to the present embodiment further includes a unit configured to close the at least one flow passage (at least one of FP 1  to FP 14 ) that is formed in the weight  52 . Thus, by appropriately closing the flow passage (at least one of FP 1  to FP 14 ) of the weight  52  by the above unit, the moving resistance of the weight  52  in the oil  60  changes. That is, the transport apparatus in which the seat device  12  is disposed can have different vibration characteristics depending on a type or kind of the transport apparatus; however, by adjusting the moving resistance of the weight  52  in accordance with different vibration characteristic, the damper device  10  having an excellent versatility can be obtained. 
     In the present embodiment, the unit configured to close the flow passage includes the screw hole  93  that is formed in the flow passage. By screwing the bolt or the like into the screw hole  93  or detaching the bolt or the like from the screw hole  93 , it is possible to open or close the flow passage (at least one of FP 1  to FP 14 ). Therefore, the damping characteristic can be adjusted easily in accordance with the target object whose vibration should be suppressed, the condition of use, or the like. The viscosity of the oil  60 , that is, the kind of the oil  60  can be changed. 
     The damper device  10  according to the present embodiment further includes: one support part (first support part  80 A) configured to slidably support one end part of the weight  52 ; and the other support part (second support part  80 B) configured to slidably support the other end part of the weight  52 . 
     The weight  52  that is stored in the case  50  containing the oil  60  slides in the left-right direction, for example, along the central guide rod  64  that is inserted into the central through hole  62  of the weight  52 , due to the vibration. In this case, the one support part slidably supports one end part of the weight  52  and the other support part slidably supports the other end part of the weight  52 . Therefore, the weight  52  can stably slide in the oil  60  without a backlash. 
     The present invention is not limited to the embodiment above, and can be changed freely within the range not departing from the concept of the present invention. For example, as illustrated in  FIG. 8 , the damper device  10  may include a right stopper  200 R and a left stopper  200 L at a central part of the weight  52 . 
     The right stopper  200 R includes a right plate member  202 R whose longitudinal direction coincides with the left-right direction, a right long hole  204 R formed in the right plate member  202 R and having a long diameter in the left-right direction, and a right adjusting screw  206 R that is screwed into the weight  52  through the right long hole  204 R. 
     Similarly, the left stopper  200 L includes a left plate member  202 L whose longitudinal direction coincides with the left-right direction, a left long hole  204 L formed in the left plate member  202 L and having a long diameter in the left-right direction, and a left adjusting screw  206 L that is screwed into the weight  52  through the left long hole  204 L. 
     Then, by loosening the right adjusting screw  206 R and the left adjusting screw  206 L, thereafter moving the right plate member  202 R and the left plate member  202 L in the left-right direction, and then fastening the right adjusting screw  206 R and the left adjusting screw  206 L, the positions of the right stopper  200 R and the left stopper  200 L can be adjusted appropriately. Therefore, a maximum moving amount of the weight  52  in the left-right direction can be adjusted. Needless to say, one of the right stopper  200 R and the left stopper  200 L may be adjusted. 
     The transport apparatus in which the seat device  12  is disposed can have different vibration characteristics depending on a type or kind of the transport apparatus; however, by adjusting the maximum moving amount of the weight  52  in the left-right direction in accordance with each different vibration characteristic, it is possible to provide the damper device  10  having an excellent versatility.