Patent Publication Number: US-2022235843-A1

Title: Damper device

Description:
TECHNICAL FIELD 
     The present invention relates to a damper device filled with viscous liquid. 
     BACKGROUND ART 
     Patent Literature 1 discloses a damper including a rotatable rotor, a housing and a cap for housing the rotor, a damping medium filled in a rotation region of the rotor, and a sealing portion provided outside the rotation region of the rotor and communicating with the rotation region. The housing and the cap have a plurality of annular protrusions, and the rotor has a plurality of annular rotor protrusions protruding upward and downward. The rotor protrusion is fitted into a gap between the annular protrusions of the housing and the cap. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: JP-A-2016-102524 
     SUMMARY OF INVENTION 
     Technical Problem 
     In the technique disclosed in Patent Literature 1, gas present in the sealing portion may move to the gaps around the annular protrusion to reduce a damping force. 
     An object of the present invention is to provide a damper device capable of stably generating a damping force. 
     Solution To Problem 
     In order to solve the above problems, a damper device according to a certain aspect of the present invention includes: a base, a rotor rotatably supported by the base; a cap defining a housing chamber of the rotor together with the base; and viscous liquid filled in the housing chamber. The base and the cap define a reservoir chamber for the viscous liquid on an outer side of the housing chamber in a radial direction, and a gap between the housing chamber and the reservoir chamber is sealed. 
     Advantageous Effects of Invention 
     According to the present invention, it is possible to provide a damper device capable of stably generating a damping force. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a damper device according to an embodiment, 
         FIG. 2  is an exploded view of the damper device according to the embodiment. 
         FIG. 3  is a cross-sectional view of the damper device according to the embodiment. 
         FIG. 4  is a diagram showing arm assembly process of the damper device according to the embodiment. 
         FIG. 5  is a diagram showing a continuation of the assembly process of the damper device of  FIG. 4 . 
         FIG. 6  is a diagram showing a continuation of the assembly process of the damper device of  FIG. 5 . 
         FIG. 7  is a diagram showing a continuation of the assembly process of the damper device of  FIG. 6 . 
         FIG. 8  is a partial cross-sectional view of the damper device. 
         FIG. 9  is an exploded view of a damper device according to a first modification. 
         FIG. 10  is a perspective cross-sectional view of the damper device according to the first modification. 
         FIG. 11  is a partially enlarged view of the damper device shown in  FIG. 10 . 
         FIG. 12  is a diagram showing an assembly process of the damper device according to the first modification. 
         FIG. 13  is a perspective cross-sectional view of a damper device according to a second modification. 
         FIG. 14  is a partially enlarged view of the damper device shown in  FIG. 13 . 
         FIG. 15  is a diagram showing an assembly process of the damper device according to the second modification. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
       FIG. 1  is a perspective view of a damper device  10  according to an embodiment. The damper device  10  is attached to, for example, a glove box of a vehicle, and applies a damping force to an opening and closing operation of an opening and closing body (lid member) of the glove box. Further, the damper device  10  may be attached to a console box of the vehicle, and may apply a damping force to opening and closing of an opening and closing body of the console box. In any case, the damper device  10  is attached to the fixed body and the opening and closing body that opens and closes an opening of the fixed body. 
     The damper device  10  includes a base  20 , a cap  22 , a rotor  24 , a coupling gear  26 , a seal ring (not shown), and viscous liquid (not shown). The viscous liquid is filled between the base  20  and the cap  22 , and applies viscous resistance to rotation of the rotor  24 . The viscous liquid is, for example, oil such as grease, and is filled so as not to leak from between the base  20  and the cap  22 . 
     The base  20  is coupled to one of the fixed body and the opening and closing body, and the coupling gear  26  is coupled to the other of the fixed body and the opening and closing body. For example, the coupling gear  26  is coupled to the opening and closing body via a rack gear and the like, rotates in accordance with movement of the opening and closing body, and the base  20  is coupled to the fixed body. The rotor  24  rotates together with the coupling gear  26 , receives a resistance force from the viscous liquid, and generates a damping force, An aspect of use of the damper device  10  is not limited to an aspect in which the base  20  is disposed on a lower side and the coupling gear  26  is disposed on an upper side as shown in  FIG. 1 , and the damper device  10  may be used in a state where a rotation axis of the rotor  24  is inclined with respect to a vertical direction. 
       FIG. 2  is an exploded view of the damper device  10 . Further,  FIG. 3  is a cross-sectional view of the damper device  10 . Both of the cross-sectional views of the damper device  10  shown in (a) of  FIG. 3  and (b) of  FIG. 3  are taken along an axial direction, but rotational positions are different.  FIGS. 2 and 3  show a state where the viscous liquid is not filled. 
     The base  20  includes a peripheral wall portion  30 , a recessed portion  32 , a base inclined surface  34 , an annular groove portion  36 , an annular recessed portion  38 , tooth portions  40 , and a coupling hole portion  42 . The cap  22  includes an insertion hole  60 , an outer peripheral wall portion  62 , a cap inclined surface  64 , and an inner peripheral groove portion  66 . The rotor  24  includes a rotation shaft portion  50 , an inclined portion  52 , a through hole portion  54 , an annular wall portion  56 , and a protruding portion  58 . The coupling gear  26  has a coupling hole  68 . 
     The base  20  is formed in a bottomed cylindrical shape. The recessed portion  32 , the base inclined surface  34 , and the annular groove portion  36  are formed in a bottom portion of the base  20 . The recessed portion  32  is formed to be recessed in a cylindrical shape at a center of the base  20 . In an assembly process, a large amount of viscous liquid can be easily placed on the recessed portion  32 . 
     The base inclined surface  34  is formed on an inner surface of the base  20 , is inclined so as to rise outward in a radial direction from the recessed portion  32 , and is inclined with respect to a plane orthogonal to the axial direction. That is, the base inclined surface  34  extends in a direction away from the bottom surface of the base  20  outward in the radial direction. The base inclined surface  34  is formed in a conical shape recessed from an inner edge of the annular groove portion  36  toward the recessed portion  32 . 
     The annular groove portion  36  is continuously provided on an outer side of the base inclined surface  34  in the radial direction, and is formed to be recessed in an annular shape. The annular groove portion  36  guides the rotation of the rotor  24 . The peripheral wall portion  30  is formed so as to be continuous with the annular groove portion  36  and to be erected on an outer periphery of the base  20 . The tooth portions  40  are formed on an outer peripheral surface of the peripheral wall portion  30 . The tooth portions  40  engage with, for example, a fixed body to restrict the rotation of the base  20 . 
     The annular recessed portion  38  is formed by recessing an upper end portion of the peripheral wall portion  30 , and is formed in an annular shape along the peripheral wall portion  30 . Remaining viscous liquid is housed in the annular recessed portion  38 . The peripheral wall portion  30  includes an inner wall portion  30   a  and an outer wall portion  30   b  that sandwich the annular recessed portion  38  in the radial direction. The inner wall portion  30   a  is set to have a height lower than that of the outer wall portion  30   b  in the axial direction. Accordingly, it is difficult for the viscous liquid to move to an outer diameter side from the outer wall portion  30   b.  A tip end side of the inner wall portion  30   a  is inclined in a tapered shape so as to rise outward in the radial direction. 
     The coupling hole portion  42  is formed in an annular shape on a lower surface of the base  20 , and is engaged with a protrusion formed on a pedestal to which the damper device  10  is attached. Accordingly, the damper device  10  can be stably attached. Further, by forming the coupling hole portion  42  not on a center side but on an outer side of the annular groove portion  36  in the radial direction and providing the coupling hole portion  42  at a position overlapping when viewed in the axial direction of a reservoir chamber  44 , it is possible to suppress an increase in a height of the base  20  in the axial direction. 
     The rotation shall portion  50  of the rotor  24  is erected at a center of the rotor  24  and is formed in a columnar shape. The rotor  24  rotates around an axis of the rotation shaft portion  50 . A flat surface to be fitted to the coupling gear  26  is formed on a side surface on a tip end side of the rotation shall portion  50 . The inclined portions  52  protrude outward in the radial direction from the rotation shaft portion  50  and are formed at equal intervals in a peripheral direction. As shown in  FIG. 2 , the through hole portion  54  is formed between adjacent inclined portions  52 . The inclined portion  52  extends so as to rise outward in the radial direction from the rotation shaft portion  50 , and is inclined along the base inclined surface  34  as shown in (a) of  FIG. 3 . The inclined portion  52  is inclined with respect to a plane orthogonal to the rotation shaft portion  50 , and is inclined outward in the radial direction and upward in the axial direction. The inclined portion  52  and the through hole portion  54  have the same length in the radial direction. 
     The annular wall portion  56  is formed in a cylindrical shape, is located on an outer side of the plurality of inclined portions  52  in the radial direction, and is suspended from an outer peripheral edge of the inclined portions  52 . The annular wall portion  56  fits into and engages with the annular groove portion  36  of the base  20 , and stabilizes the rotation of the rotor  24 . 
     The protruding portion  58  is formed in a columnar shape such that the rotation shaft portion  50  protrudes downward, and is coaxial with the rotation shaft portion  50 . An axial groove for securing a movement path of gas is formed on an outer peripheral surface of the protruding portion  58 . The rotation of the rotor  24  can be stabilized by the protruding portion  58  being fitted into and engaged with the recessed portion  32 . 
     The cap  22  defines a housing chamber  70  of the rotor  24  together with the base  20  with the rotor  24  sandwiched between the cap  22  and the base  20 . The insertion hole  60  is formed at a center of the cap  22 , and exposes the rotation shaft portion  50  of the rotor  24  to the outside from the housing chamber  70 . The rotation shaft portion  50  is inserted into the insertion hole  60 . The outer peripheral wall portion  62  is formed in a cylindrical shape on an outer periphery of the cap  22 . 
     The inner peripheral groove portion  66  is formed on an inner side of the outer peripheral wall portion  62 , receives the peripheral wall portion  30  of the base  20 , and is joined to the peripheral wall portion  30 . The inner peripheral groove portion  66  faces the annular recessed portion  38  of the base  20 . Although the joining method will be described later, a first seal portion  46  and a second seal portion  48  are formed by welding. The first seal portion  46  and the second seal portion  48  in (a) of  FIG. 3  and (h) of  FIG. 3  are shown in a state where the base  20  and the cap  22  in seal portions overlap with each other and are not melted. 
     The first seal portion  46  is formed on an inner peripheral surface of the peripheral wall portion  30 , and the second seal portion  48  is formed on the outer peripheral surface of the peripheral wall portion  30 . The reservoir chamber  44  is formed on an outer side of the housing chamber  70  in the radial direction by closing with the first seal portion  46  and the second seal portion  48 . The base  20  and the cap  22  define the reservoir chamber  44  of the viscous liquid on the outer side of the housing chamber  70  in the radial direction. The reservoir chamber  44  is formed by the peripheral wall portion  30  of the base  20  and the inner peripheral groove portion  66  of the cap  22 , and a volume of the reservoir chamber  44  is secured by the annular recessed portion  38 . The reservoir chamber  44  is formed along the peripheral direction, and houses the viscous liquid discharged from the housing chamber  70 . The housing chamber  70  side is filled with sufficient viscous liquid, and the remaining viscous liquid is housed in the reservoir chamber  44 , 
     The cap inclined surface  64  is formed on an inner surface of the cap  22 , is inclined so as to be lowered inward in the radial direction, and is inclined with respect to a plane orthogonal to the axial direction. The cap inclined surface  64  is formed along and parallel to the inclined portion  52  and the base inclined surface  34 . The inclined portion  52  of the rotor  24  is sandwiched by the base inclined surface  34  and the cap inclined surface  64 . The inclined portion  52  is located in a region in the housing chamber  70  formed by the base inclined surface  34  and the cap inclined surface  64 . That is, the base inclined surface  34  faces a lower surface of the inclined portion  52 , the cap inclined surface  64  faces an upper surface of the inclined portion  52 , and the base inclined surface  34 , the inclined portion  52 , and the cap inclined surface  64  overlap with each other when viewed in the axial direction. Accordingly, the housing chamber  70  is formed so as to rise outward in the radial direction from a position of the rotation shaft portion SO. 
     The seal ring  28  surrounds the rotation shaft portion  50 , abuts on an outer peripheral surface of the rotation shaft portion  50  and an inner peripheral surface of the insertion hole  60 , and suppresses leakage of the viscous liquid in the housing chamber  70  through the insertion hole  60 . 
       FIG. 4  is a diagram showing an assembly process of the damper device  10 . As shown in (a) of  FIG. 4 , a discharge port of a discharge device  72  is aligned with a center position of the base  20 , and the discharge device  72  discharges viscous liquid  74 . As shown in (b) of  FIG. 4 , the viscous liquid  74  is placed on the center of the base  20 , and is discharged more than a necessary amount into the housing chamber  70 . A larger amount of the viscous liquid  74  is easily placed on the base  20  by the recessed portion  32 . 
       FIG. 5  is a diagram showing a continuation of the assembly process of the damper device  10  of  FIG. 4 . As shown in (a) of  FIG. 5 , the rotor  24  approaches the base  20  from above, and is placed on the base  20  as shown in (b) of  FIG. 5 . When the rotor  24  approaches the base  20 , the protruding portion  58  enters the recessed portion  32  to push the viscous liquid  74 , and the viscous liquid  74  protrudes upward from the through hole portion  54  to be in a raised state. 
     The protruding portion  58  of the rotor  24  is accommodated in and engaged with the recessed portion  32  of the base  20 . When the recessed and protruding relationship between the base  20  and the rotor  24  is reversed, gas may remain in the recessed portion of the rotor  24 , but the formation of the protruding portion  58  on the rotor  24  can suppress reservoir of the gas. Further, since the base inclined surface  34  is formed so as to rise along the inclined portion  52  of the rotor  24 , the gas on a center side can be guided to the outer side in the radial direction. 
       FIG. 6  is a diagram showing a continuation of the assembly process of the damper device  10  of  FIG. 5 . As shown in (a) of  FIG. 6 , the cap  22  approaches the base  20  side from above, and as shown in (b) of  FIG. 6 , the cap inclined surface  64  comes into contact with the raised viscous liquid  74  and pushes and spreads the viscous liquid  74 . The viscous liquid  74  and the gas are guided by the cap inclined surface  64  and the inclined portion  52 , spread in the radial direction, and are guided toward the annular recessed portion  38  by the inclination. Since the cap inclined surface  64  and the inclined portion  52  are inclined so as to rise outward in the radial direction, the gas in the housing chamber  70  is easily pushed outward in the radial direction. 
       FIG. 7  is a diagram showing a continuation of the assembly process of the damper device  10  of  FIG. 6 . As shown in (a) of  FIG. 7 , when the cap  22  approaches the base  20 , a tip end of the outer peripheral wall portion  62  abuts on the outer wall portion  30   b,  and the approach is stopped. At this time, the viscous liquid  74  is pushed by the cap  22  and spreads to the annular groove portion  36  and the annular recessed portion  38 . 
     In a state where the tip end of the outer peripheral wall portion  62  and the outer wall portion  30   b  abut on each other, an ultrasonic welding device  76  is driven, an abutting portion is melted to make the approach possible, the cap  22  is pushed to further approach the base  20 , and an inner peripheral edge of the inner peripheral groove portion  66  abuts on the inner wall portion  30   a.  The second seal portion  48  is formed by melting the abutting portion between the tip end of the outer peripheral wall portion  62  and the outer wall portion  30   b,  and it is possible to suppress the viscous liquid  74  from leaking to the outside of the damper device  10 . 
     While the abutting portion between the tip end of the outer peripheral wall portion  62  and the outer wall portion  30   b  is melted, an abutting portion between the inner peripheral edge of the inner peripheral groove portion  66  and the inner wall portion  30   a  starts to be melted by the ultrasonic welding device  76 , and the first seal portion  46  is formed. As shown in (b) of  FIG. 7 , the communication between the housing chamber  70  and the reservoir chamber  44  is blocked by the first seal portion  46 . The first seal portion  46  seals between the housing chamber  70  and the reservoir chamber  44 . Accordingly, it is possible to restrict the return of the gas to the housing chamber  70  after the gas is pushed into the reservoir chamber  44 , and it is possible to suppress that the viscous resistance generated during the rotation of the rotor  24  cannot be stably exhibited due to the reservoir of air bubbles in the housing chamber  70 . The reservoir chamber  44  is closed with respect to the outside by the second seal portion  48  on an outer side of the reservoir chamber  44  in the radial direction, and leakage of the viscous liquid  74  to the outside is suppressed. 
     As shown in (b) of  FIG. 7 , after the base  20  and the cap  22  are fixed, the coupling gear  26  is mounted on the rotation shaft portion  50 , and the assembly process of the damper device  10  is completed. 
       FIG. 8  is a partial cross-sectional view of the damper device  10 . In  FIG. 8 , a portion where the first seal portion  46  and the second seal portion  48  are formed is shown in a state where the base  20  and the cap  22  overlap with each other, but actually, the overlapping portions are melted and joined. 
     As described in the assembly process, the second seal portion  48  is melted prior to the first seal portion  46  and starts to be welded. Since the second seal portion  48  is formed prior to the first seal portion  46 , a seal margin L 2  of the second seal portion  48  is formed to be larger than a seal margin L 1  of the first seal portion  46  and to be longer in the axial direction. The first seal portion  46  and the second seal portion  48  are formed in an annular shape, and a length of the first seal portion  46  in the axial direction is the seal margin L 1 , and a length of the second seal portion  48  in the axial direction is the seal margin L 2 . 
     Accordingly, when the cap  22  is pushed to the base  20  side, a path for pushing out the gas from the housing chamber  70  to the reservoir chamber  44  side can be secured until the pushing is completed. That is, the gas can be pushed out from the housing chamber  70  even while the second seal portion  48  is formed. Accordingly, the viscous liquid  74  is filled in the housing chamber  70  at a sufficient filling rate. Further, by starting the formation of the second seal portion  48  first, it is possible to suppress the leakage of the viscous liquid  74  to the outside in a process of pushing in the cap  22 . 
     Further, since the seal margin L 1  of the first seal portion  46  is longer than the seal margin L 2  of the second seal portion  48 , the second seal portion  48  is started to be welded from the middle of welding the first seal portion  46 , and the cap  22  is pushed to the base  20  side while both the first seal portion  46  and the second seal portion  48  are melted. Accordingly, the first seal portion  46  and the second seal portion  48  can be formed in one pushing process, and the working efficiency can be improved. 
     Since the viscous resistance generated during the rotation of the rotor  24  is generated mainly in a region of the annular wall portion  56 , it is necessary to secure the lengths of the annular wall portion  56  and the annular groove portion  36  in the axial direction in order to generate a desired damping force. Since the inclined portion  52  is raised, even if the annular wall portion  56  is suspended from the inclined portion  52 , it is possible to suppress an increase in a length of the entire damper device  10  in the axial direction. Further, since the reservoir chamber  44  is provided at a position that does not overlap with the annular wall portion  56  when viewed in the axial direction, it is possible to suppress an increase in the length of the damper device  10  in the axial direction while securing the length of the annular wall portion  56  in the axial direction. 
     Since the reservoir chamber  44  is provided at a position overlapping with the housing chamber  70  When viewed in the radial direction, it is possible to suppress the height of the damper device  10  in the axial direction. The base inclined surface  34  extends to the annular groove portion  36 , and is formed such that the entire portion thereof facing the inclined portion  52  and the through hole portion  54  is inclined. 
       FIG. 9  is an exploded view of a damper device according to a first modification. A damper device  100  of the first modification is different from the damper device  10  shown in  FIG. 2  mainly in that a cap is divided into two members. 
     The damper device  100  includes members of a base  120 , a first cap  122   a,  a second cap  122   b,  a seal ring  28 , and a rotor  124 . The rotor  124 , the seal ring  28 , the first cap  122   a,  and the second cap  122   b,  with the base  120  as a bottom, are attached in this order from above. The configuration of each member will be described with reference to new drawings. 
       FIG. 10  is a perspective cross-sectional view of the damper device  100  according to the first modification. Further,  FIG. 11  is a partially enlarged view of the damper device  100  shown in  FIG. 10 . The damper device  100  further includes a first seal portion  93 , a second seal portion  94 , a third seal portion  95 , and a fourth seal portion  96  that join the respective members. The base  120  includes a bottom portion  80 , an inner wall portion  82   a,  and an outer wall portion  82   b.    
     The bottom portion  80  of the base  120  is also a bottom portion of the damper device  100 , and constitutes a bottom surface of a housing chamber  170 . The inner wall portion  82   a  and the outer wall portion  82   b  are erected from the bottom portion  80  and face each other. The inner wall portion  82   a  is located on an inner side of the outer wall portion  82   b.  The housing chamber  170  is located on an inner side of the inner wall portion  82   a,  and a reservoir portion  144  is located between the inner wall portion  82   a  and the outer wall portion  82   b.    
     The rotor  124  includes a rotation shaft portion  150  and a protruding portion  152 . The rotation shaft portion  150  is erected at a center of the rotor  124  and is formed in a columnar shape. The protruding portion  152  protrudes outward in the radial direction from the rotation shaft portion  150  and is housed in the housing chamber  170 . 
     The first cap  122   a  defines the base  120  and the housing chamber  170 . The housing chamber  170  is filled with the viscous liquid  74 . The second cap  122   b  is fixed to the base  120  and suppresses the first cap  122   a  from coming off. Accordingly, after the first cap  122   a  closes the housing chamber  170 , the second cap  122   b  can suppress the first cap  122   a  from coming off while maintaining a state where the housing chamber  170  is closed. Accordingly, an amount of air remaining in the housing chamber  170  can be reduced. 
     The first cap  122   a  includes a first annular plate portion  84 , a first peripheral wall portion  86 , and an engaging portion  88 . The first annular plate portion  84  has the insertion hole  60  at a center, and extends outward in the radial direction from the insertion hole  60 . The first annular plate portion  84  has an annular rib  84   a  formed to protrude at an upper surface. The first peripheral wall portion  86  protrudes so as to be suspended from an outer peripheral edge of the first annular plate portion  84 , and is formed in a substantially cylindrical shape. 
     The engaging portion  88  is formed at a tip end portion of the first peripheral wall portion  86 , and is engaged with the inner wall portion  82   a  of the base  120  so as to face the inner wall portion  82   a  in the axial direction. The engaging portion  88  is located between the housing chamber  170  and the reservoir chamber  144 . Accordingly, the housing chamber  170  defined by the base  120  and the first cap  122   a  is closed. 
     The engaging portion  88  is formed in a convex shape protruding downward, and a tip end portion of the inner wall portion  82   a  is formed in a concave shape. Accordingly, the engaging portion  88  and the tip end portion of the inner wall portion  82   a  can be engaged with each other in a concavo-convex manner, and the base  120  and the first cap  122   a  can be suppressed from being displaced in the radial direction. 
     The second cap  122   b  includes a second annular plate portion  90  and a second peripheral wall portion  92 . The second annular plate portion  90  has a central hole  90   a  and extends outward in the radial direction from the central hole  90   a.  The second peripheral wall portion  92  protrudes so as to be suspended from a lower surface of the second annular plate portion  90 , and is formed in a substantially cylindrical shape. The second peripheral wall portion  92  is located in the middle in a range in the radial direction of the second annular plate portion  90 . That is, the second annular plate portion  90  protrudes outward in the radial direction from the second peripheral wall portion  92 . 
     The annular rib  84   a  enters an inner side of the central hole  90   a,  and an inner peripheral region of the second annular plate portion  90  overlaps with an outer peripheral region of the first annular plate portion  84  in the axial direction. The second peripheral wall portion  92  is inserted between the inner wall portion  82   a  and the outer wall portion  82   b,  and. is located on an outer side of the first peripheral wall portion  86  in the radial direction. 
     The second peripheral wall portion  92  of the second cap  122   b  has a plurality of ribs  92   a  on the outer peripheral surface thereof. The plurality of ribs  92   a  are formed so as to protrude from the outer peripheral surface of the second peripheral wall portion  92 , and are formed so as to be separated from each other in the peripheral direction. The ribs  92   a  are provided in a shape along an inner peripheral surface of the outer wall portion  82   b.  When the second peripheral wall portion  92  is pushed into a space between the inner wall portion  82   a  and the outer wall portion  82   b,  the plurality of ribs  92   a  abut on the outer wall portion  82   b,  such that a pushing posture of the second cap  122   b  is stabilized. 
     The first seal portion  93 , the second seal portion  94 , the third seal portion  95 , and the fourth seal portion  96  shown in  FIG. 11  are formed by welding. In  FIGS. 10 and 11 , the seal portion of each member is shown in a state of not being melted by welding. 
     The first seal portion  93  is formed by welding an outer peripheral surface of the first peripheral wall portion  86  of the first cap  122   a  and an inner peripheral surface of the second peripheral wall portion  92  of the second cap  122   b.  The first seal portion  93  is located between the housing chamber  170  and the reservoir portion  144  in the radial direction, and fixes the first cap  122   a  and the second cap  122   b.  The first seal portion  93  blocks communication between the housing chamber  170  and the outside, and seals leakage of the viscous liquid  74  from the housing chamber  170 . 
     The second seal portion  94  is formed by welding an outer peripheral surface of the inner wall portion  82   a  of the base  120  and the inner peripheral surface of the second peripheral wall portion  92  of the second cap  122   b.  The second seal portion  94  is located between the housing chamber  170  and the reservoir portion  144  in the radial direction, blocks communication between the housing chamber  170  and the reservoir portion  144 , and seals the leakage of the viscous liquid  74  from the housing chamber  170 . 
     The second cap  122   b  is fixed to the base  120  to seal between the housing chamber  170  and the reservoir chamber  144  by the first seal portion  93  and the second seal portion  94 , and is fixed (welded in the embodiment) to the first cap  122   a.  Accordingly, the first cap  122   a  has a function of closing the housing chamber  170 , and the second cap  122   b  has a function of fixing to the base  120 . 
     The first seal portion  93  and the second seal portion  94  are continuous with the engaging portion  88 , and are formed continuously in the axial direction on an outer side of the engaging portion  88  in the radial direction. That is, a space between the engaging portion  88  and the inner wall portion  82   a  is sealed up and down, and the viscous liquid  74  is restricted from moving to the outer side in the radial direction from the space between the engaging portion  88  and the inner wall portion  82   a.  Further, the second cap  122   b  is joined to the first cap  122   a  and the base  120  by welding. By the first seal portion  93  and the second seal portion  94  sealing positions close to the housing chamber  170 , it is possible to suppress the viscous liquid  74  injected in advance from being scattered to various places, and to stabilize a sealing amount in the housing chamber  170 . 
     The third seal portion  95  is formed by welding the outer peripheral surface of the second peripheral wall portion  92  and the inner peripheral surface of the outer wall portion  82   b.  The third seal portion  95  is located on an outer side of the reservoir portion  144  and seals the leakage of the viscous liquid  74  from the reservoir portion  144 . Further, the third seal portion  95  joins the second cap  122   b  and the base  120 . 
     The fourth seal portion  96  is formed by welding an outer peripheral surface of the first annular plate portion  84  and the inner peripheral surface of the second peripheral wall portion  92 . The fourth seal portion  96  seals the viscous liquid  74  from leaking from a gap between the first cap  122   a  and the second cap  122   b.  Further, the fourth seal portion  96  joins the first cap  122   a  and the second cap  122   b.    
     The first seal portion  93  and the fourth seal portion  96  can double seal the viscous liquid  74  from leaking from the gap between the first cap  122   a  and the second cap  122   b . Further the second seal portion  94  and the third seal portion  95  can double seal the viscous liquid  74  from leaking from a gap between the second cap  122   b  and the base  120 . 
       FIG. 12  is a diagram showing an assembly process of the damper device  100  according to the first modification. The viscous liquid  74  is placed on a center of the base  120 , the rotor  124  is placed on the base  120 , and the first cap  122   a  is pressed from above toward the base  120 . Accordingly, the viscous liquid  74  passes through a gap between the engaging portion  88  and the inner wall portion  82   a  and is pushed to the reservoir portion  144  side. 
     Further, the first cap  122   a  approaches the base  120 , and as shown in (a) of  FIG. 12 , the engaging portion  88  of the first cap  122   a  is in a state of being engaged with the tip end portion of the inner wall portion  82   a  of the base  120 . By the engagement between the engaging portion  88  and the inner wall portion  82   a,  the housing chamber  170  is closed, and the movement of the viscous liquid  74  is restricted. 
     In a state where the housing chamber  170  is closed, a process of welding the second cap  122   b  is executed. Accordingly, it is possible to suppress the viscous liquid  74  from being compressed in the housing chamber  170  due to the pushing of the second cap  122   b.  The second cap  122   b  approaches the base  120  in a state where the second peripheral wall portion  92  is aligned between the inner wall portion  82   a  and the outer wall portion  82   b . A tip end of the second peripheral wall portion  92  comes into contact with an inclined surface  97  formed on the outer peripheral surface of the first annular plate portion  84 . The inclined surface  97  is inclined so as to protrude outward in the radial direction toward the lower side, and protrudes outward in the radial direction from the inner peripheral surface of the second peripheral wall portion  92 . That is, when the second peripheral wall portion  92  is pushed into an outer periphery of the first annular plate portion  84 , the second peripheral wall portion  92  always abuts on the inclined surface  97 . 
     In a state where the second peripheral wall portion  92  comes into contact with the inclined surface  97  of the first annular plate portion  84 , the ultrasonic welding device  76  is driven to melt the abutting portion, and the second cap  122   b  further approaches the base  120 . 
     In (b) of  FIG. 12 , a state where the second cap  122   b  is pushed toward the base  120  and where the inner peripheral surface of the second peripheral wall portion  92  and the outer peripheral surface of the first peripheral wall portion  86  are melted is shown, and the first seal portion  93  starts to be generated. Further, the second peripheral wall portion  92  comes into contact with an engaging portion between the engaging portion  88  and the inner wall portion  82   a  and starts to melt, and the housing chamber  170  is sealed. By melting the engaging portion between the engaging portion  88  and the inner wall portion  82   a,  it is possible to reliably block the communication between the housing chamber  170  and the reservoir portion  144 . 
     In (b) of  FIG. 12 , an inner peripheral surface on a base end side of the second peripheral wall portion  92  comes into contact with the outer peripheral edge of the first annular plate portion  84 , and an outer peripheral surface on the base end side of the second peripheral wall portion  92  comes into contact with an inner peripheral edge on a tip end side of the outer wall portion  82   b.  The contact portion starts to be melted by the ultrasonic welding device  76 . 
     In (c) of  FIG. 12 , the pushing of the second cap  122   b  is completed, the first seal portion  93 , the second seal portion  94 , the third seal portion  95 , and the fourth seal portion  96  are formed, and the assembly of the damper device  100  is completed. The first seal portion  93  starts to be formed, then the second seal portion  94  is formed, and then the third seal portion  95  and the fourth seal portion  96  are formed. By starting welding from the first seal portion  93  and the second seal portion  94  first, the housing chamber  170  can be sealed, and then the reservoir portion  144  can be sealed. Welding start timings of the second seal portion  94 , the third seal portion  95 , and the fourth seal portion  96  may be the same. 
       FIG. 13  is a perspective cross-sectional view of a damper device  200  according to a second modification. Further,  FIG. 14  is a partially enlarged view of the damper device  200  shown in  FIG. 13 . In the damper device  200  of the second modification, positions of a first seal portion  293  and a second seal portion  294  are different from those of the damper device  100  of the first modification shown in  FIG. 10 , and the first seal portion  293  and the second seal portion  294  are located above the first seal portion  93  and the second seal portion  94  of the damper device  100 . 
     The damper device  200  includes a base  220 , a first cap  222   a,  a second cap  222   b,  the rotor  124 , the first seal portion  293 , the second seal portion  294 , and a third seal portion  295 . The base  220  includes the bottom portion  80 , an inner wall portion  282   a,  and an outer wall portion  282   b.    
     The inner wall portion  282   a  and the outer wall portion  282   b  are erected from the bottom portion  80  and face each other. The inner wall portion  282   a  is located on an inner side of the outer wall portion  282   b.  The housing chamber  170  is located on an inner side of the inner wall portion  282   a,  and a reservoir portion  244  is located between the inner wall portion  282   a  and the outer wall portion  282   b.  The inner wall portion  282   a  is erected so as to cover an outer periphery of the housing chamber  170 , and is erected above the protruding portion  152 . By forming the inner wall portion  282   a  to be high, it is possible to increase a size of the reservoir chamber  244 . 
     The first cap  222   a  is formed in a substantially disc shape, and has the insertion hole  60  at a center thereof. An engaging portion  288  of the first cap  222   a  is formed on a lower surface on an outer peripheral side, and engages with an inner wall portion  282   a  of the base  220  so as to face the inner wall portion  282   a  in the axial direction. 
     The second cap  222   b  includes a second annular plate portion  290  and a peripheral wall portion  292 . The second annular plate portion  290  extends outward in the radial direction. The peripheral wall portion  292  protrudes so as to be suspended from a lower surface of the second annular plate portion  290 , and is formed in a substantially cylindrical shape. 
     FIG,  15  is a diagram showing an assembly process of the damper device  200  according to the second modification. As shown in (a) of  FIG. 15 , the engaging portion  288  of the first cap  222   a  is in a state of being engaged with a tip end portion of the inner wall portion  282   a  of the base  220 , and in a state where the housing chamber  170  is closed, a process of welding the second cap  222   b  is executed. Accordingly, it is possible to suppress the viscous liquid  74  from being compressed in the housing chamber  170  due to the pushing of the second cap  222   b.    
     The second cap  222   b  approaches the base  220  in a state where the peripheral wall portion  292  is aligned between the inner wall portion  282   a  and the outer wall portion  282   b.  A tip end of the peripheral wall portion  292  comes into contact with an inclined surface  297  formed on an outer peripheral surface of the first cap  222   a.  An abutting portion is melted by the ultrasonic welding device  76 . 
     In (b) of FIG,  15 , a state where the second cap  222   b  is pushed toward the base  220  and where an inner peripheral surface of the peripheral wall portion  292  and the outer peripheral surface of the first cap  222   a  are melted is shown, and the first seal portion  293  starts to be formed. Further, the peripheral wall portion  292  comes into contact with an engaging portion between the engaging portion  288  and the inner wall portion  282   a  and starts to melt, and the housing chamber  170  is sealed. 
     In (b) of  FIG. 15 , an outer peripheral surface on a base end side of the peripheral wall portion  292  comes into contact with an inner peripheral edge on a tip end side of the outer wall portion  282   b.  in (c) of  FIG. 15 , the pushing of the second cap  222   b  is completed, the first seal portion  293 , the second seal portion  294 , and the third seal portion  295  are formed, and the assembly of the damper device  200  is completed. By starting welding from the first seal portion  293  and the second seal portion  294  first, the housing chamber  170  can be sealed, and then the reservoir portion  244  can be sealed. 
     The present invention is not limited to the embodiment described above and modifications such as various design changes can be added to the embodiment based on knowledge of a person skilled in the art. Embodiments to which such modifications are added can also be included in the scope of the present invention. 
     in the embodiment, an aspect in which the fixed body or the opening and closing body is coupled to the tooth portions  40  formed on the base  20  is shown, but the present invention is not limited to this aspect. For example, a flange plate-shaped mounting portion having a screw hole may be formed. In any case, when the coupling gear  26  is coupled to the opening and closing body, the base  20  is coupled to the fixed body in a state where the rotation is restricted. 
     Further, in the embodiment, an aspect in which the first seal portion  46  and the second seal portion  48  are formed by welding is shown, but the present invention is not limited to this aspect. For example, the second seal portion  48  may be formed by adhesion or mechanical coupling, and the first seal portion  46  may be formed by mechanical coupling, for example, using a seal ring. Further, without limiting to the ultrasonic welding, welding of other method such as vibration welding or laser welding may be used for formation. 
     Further, the first seal portion  93 , the second seal portion  94 , the third seal portion  95 , and the fourth seal portion  96  are not limited to being formed by welding similarly to the first seal portion  46  and the second seal portion  48 , and may be formed by adhesion or mechanical coupling. In any case, these seal portions fix the members to each other to restrict the movement of the viscous liquid  74 . That is, the fixing includes welding, adhesion, and the like. 
     Further, in the embodiment, an aspect in which the base inclined surface  34  and the cap inclined surface  64  are parallel to the inclined portion  52  of the rotor  24  is shown, but the present invention is not limited to this aspect, the base inclined surface  34  and the cap inclined surface  64  may not be parallel to the inclined portion  52 . In any case, the base inclined surface  34 , the cap inclined surface  64 , and the inclined portion  52  are inclined so as to rise outward in the radial direction, are inclined with respect to a plane orthogonal to the rotation shaft portion  50 , and guide the viscous liquid  74  to the reservoir chamber  44 . 
     INDUSTRIAL APPLICABILITY 
     The present invention relates to a damper device filled with viscous liquid. 
     REFERENCE SIGNS LIST 
       10 : damper device 
       20 : base 
       22 : cap 
       24 : rotor 
       26 : coupling gear 
       28 : seal ring 
       30 : peripheral wall portion 
       30   a:  inner wall portion 
       30   h:  outer wall portion 
       32 : recessed portion 
       34 : base inclined surface 
       36 : annular groove portion 
       38 : annular recessed portion 
       40 : tooth portion 
       42 : coupling hole portion 
       44 : reservoir chamber 
       46 : first seal portion 
       48 : second seal portion 
       50 : rotation shaft portion 
       52 : inclined portion. 
       54 : through hole portion 
       56 : annular wall portion 
       58 : protruding portion 
       60 : insertion hole 
       62 : outer peripheral wall portion 
       64 : cap inclined surface 
       66 : inner peripheral groove portion 
       68 : coupling hole 
       70 : housing chamber 
       72 : discharge device 
       74 : viscous liquid 
       76 : ultrasonic welding device 
       88 : engaging portion 
       93 : first seal portion 
       94 : second seal portion 
       122   a:  first cap 
       122   b:  second cap