Abstract:
A vibration-proof apparatus which enables the structure of a resin die to be simplified. A vibration-proof apparatus comprising: a coupling member ( 10 ) consisting of a resin material and provided with leg part ( 13 ) in which thin and thick elastic members ( 45, 46 ), which are vulcanized and bonded to short-axis and long-axis attachment bracket members ( 50, 51 ), are press-fitted, and also with a main body part ( 11 ) which is formed so as to be continuous with the leg parts; a vibration-proof base ( 40 ) for connecting an inner cylinder ( 30 ) to the main body part ( 11 ) of the coupling member ( 10 ) and consisting of a rubber-like elastic body. The direction of the axes of press-fitting holes which are formed in the leg parts ( 13 ) and into which both the elastic members ( 45, 46 ) are press-fitted and the direction of the axis of the inner cylinder ( 30 ) are configured to be parallel to each other, and as a result, when the vibration-proof apparatus ( 1 ) is removed from the resin die after the coupling member ( 10 ) is injection-molded, the vibration-proof apparatus ( 1 ) can be drawn in the same direction. Thus, the structure of the resin die can be simplified by simplifying the separation structure of the resin die.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a vibration-proof apparatus, and particularly to a vibration-proof apparatus for which the structure of a resin die can be simplified. 
       BACKGROUND ART 
       [0002]    Resin has been actively used for parts of a vibration-proof apparatus from the past in order to reduce the weight, and Patent Literature 1 discloses such a conventional vibration-proof apparatus in which resin is actively used. In the conventional vibration-proof apparatus, an inner cylinder bracket 14 to which a main body rubber 16 is vulcanized and attached in advance and an attachment bracket 30 to which an elastic member 38 is similarly vulcanized and attached are integrally formed with a bracket 20 made of resin material. According to the vibration-proof apparatus, even in the case where vibration at a frequency band that cannot be damped by the main body rubber 16 is input, the vibration can be damped by the elastic member 38. Thus, it is possible to damp vibration at a wide range of frequency bands. 
       CITATION LIST 
     Patent Literature 
       [0000]    
       
         [Patent Literature 1] Japanese Patent Application Laid-Open Publication No. H7-280034 (Paragraph [0028], FIG. 2 and the like) 
       
     
       SUMMARY OF INVENTION 
     Technical Problem 
       [0004]    However, in the above-described conventional vibration-proof apparatus, the axial directions of the inner cylinder bracket 14 and the attachment bracket 30 are orthogonal to and different from each other. Thus, the split structure of a resin die used for molding the vibration-proof apparatus is complicated, resulting in a problem of complication of the structure of the resin die. 
         [0005]    The present invention has been achieved to address the above-described problem, and an object thereof is to provide a vibration-proof apparatus for which the structure of a resin die can be simplified. 
       Solution to Problem 
       [0006]    For achieving the object, Claim  1  defines a vibration-proof apparatus comprising: a plurality of first attachment members that are attached on the automobile body side; coupling members made of resin material that include leg parts in which the plurality of first attachment members are arranged and a main body part that is formed continuously from the leg parts; a second attachment member that is attached on the vibration generator side; and a vibration-proof base made of rubber-like elastic material that couples the second attachment member to the main body part of the coupling members. A plurality of elastic members made of rubber-like elastic material that couple the plurality of first attachment members to the leg parts of the coupling members are provided, each of the first attachment members and the second attachment member is formed in a cylindrical shape having a through-hole, the first attachment members are inserted into the leg parts of the coupling members for molding or pressed thereinto together with the elastic members, and the axial directions of the first attachment members or press-fit holes which are formed at the leg parts of the coupling members and into which the first attachment members and the elastic members are pressed are parallel with the axial direction of the second attachment member. 
         [0007]    According to Claim  2 , in the vibration proof apparatus according to Claim  1 , the plurality of elastic members are different from each other in spring constant. 
         [0008]    According to Claim  3 , in the vibration proof apparatus according to Claim  2 , the plurality of press-fit holes are formed at the leg parts of the coupling members and the plurality of press-fit holes are different from each other in inner diameter. 
         [0009]    According to Claim  4 , in the vibration proof apparatus according to any one of Claims  1  to  3 , each of the first attachment members includes protrusions that protrude from both ends of the cylindrical shape; the first attachment members are attached on the automobile body side after each of the first attachment members is inserted between a pair of plate-like wall parts that are fixed and attached on the automobile body side and stand at a predetermined interval, and then a bolt member is inserted and fastened into hole parts drilled at the wall parts and the through-hole of each of the first attachment members. In the case where each of the first attachment members is inserted between the wall parts, the protrusions abut on end portions of the wall parts to match the positions of the hole parts drilled at the wall parts with the position of the through-hole of each of the first attachment members. 
       Advantageous Effects of Invention 
       [0010]    According to the vibration-proof apparatus described in claim  1 , the resin material is injected into a cavity of the resin die into which the second attachment member, the vibration-proof base, the plural first attachment members and the plural elastic members are inserted to mold the coupling members by injection, so that these members are integrally formed. 
         [0011]    Here, the plural first attachment members and elastic members are arranged at the leg parts of the coupling members. Accordingly, in the case where these first attachment members are mounted on the automobile body side and the second attachment member is mounted on the vibration generator side, the vibration generator can be stably and advantageously supported on the automobile body side. 
         [0012]    Further, the axial directions of the first attachment members or the axial directions of the press-fit holes which are formed at the leg parts of the coupling members and into which the first attachment members and the elastic members are pressed are parallel with the axial direction of the second attachment member. Accordingly, in the case where the vibration-proof apparatus is removed from the resin die after the coupling members are molded by injection, the vibration-proof apparatus can be removed in the same direction. Thus, the structure of the resin die can be advantageously simplified by simplifying the split structure of the resin die. 
         [0013]    According to the vibration-proof apparatus described in claim  2 , in addition to the effects obtained by the vibration-proof apparatus described in claim  1 , the plural first attachment members are arranged at the leg parts of the coupling members and the plural first attachment members and leg parts of the coupling members are coupled to each other through the plural elastic members. Thus, a mass-spring system can be configured while the coupling members serve as masses (mass members) and the vibration-proof base and the plural elastic members serve as springs. In this case, according to the present invention, the plural elastic members are different from each other in the spring constant. Thus, the vibration mode can be changed without changing the arrangement positions of the first attachment members (elastic members). Specifically, for example, the rubber hardness of each of the plural elastic members is changed, so that the vibration mode can be changed by individually adjusting the spring constant of each of the elastic members. Thus, it is not necessary to change the shape of the resin die in order to adjust the arrangement positions of the first attachment members. Thus, the vibration mode of the vibration-proof apparatus can be easily changed. 
         [0014]    As a result, for example, in the case where the vibration-proof apparatus is used as a dynamic damper (vibration damper) for suppressing the vibration on the automobile body side or the vibration generator side, tuning work for adjusting the unique vibration of the dynamic damper to the resonance frequency on the automobile body side can be easily performed at a low cost. On the other hand, even if the vibration-proof apparatus is not used as the dynamic damper to suppress the resonance, the work for adjusting the vibration mode of the vibration-proof apparatus to suppress the resonance can be easily performed at a low cost as similar to the above. 
         [0015]    Further, if the plural elastic members are different from each other in the spring constant as the present invention, the position of the center of the gravity of the mass member can be shifted from the center lines of the springs in the mass-spring system. Thus, in the case where the vibration-proof apparatus is used as the dynamic damper (vibration damper), plural vibration modes can be advantageously and continuously generated. 
         [0016]    According to the vibration-proof apparatus described in claim  3 , in addition to the effects obtained by the vibration-proof apparatus described in claim  2 , the plural press-fit holes are formed at the leg parts of the coupling members, and the plural press-fit holes are different from each other in inner diameter. Thus, even in the case where the elastic member (and the first attachment member) pressed into one press-fit hole and the elastic member (and the first attachment member) pressed into the other press-fit hole are configured in the same dimension and characteristic, the spring constant can be made different by changing each press-fit allowance. As a result, the elastic member (and the first attachment member) pressed into one press-fit hole and the elastic member (and the first attachment member) pressed into the other press-fit hole can be used as common members. Thus, the cost of the parts can be advantageously reduced to reduce the cost of the product as the whole vibration-proof apparatus. 
         [0017]    According to the vibration-proof apparatus described in claim  4 , in addition to the effects obtained by the vibration-proof apparatus described in any one of claims  1  to  3 , in the case where the first attachment member is inserted between the wall parts, the protrusions provided at the both ends of the cylindrical shape abut on end portions of the wall parts to restrict insertion and movement of the first attachment member into the wall parts, so that the position of the through-hole of the first attachment member matches the positions of the hole parts drilled at the wall parts. Thus, it is possible to accurately match the positions of the hole parts drilled at the wall parts with the position of the through-hole formed at the first attachment member in a short time. Thus, the efficiency of work to insert and fasten a bolt member into the through-hole of the first attachment member and the hole parts drilled at the wall parts can be advantageously improved. 
         [0018]    Here, in a configuration in which the protrusion is provided only at one end of the cylindrical shape unlike the vibration-proof apparatus of claim  4 , the positions of the through-hole and the hole part on the one end side can match each other. However, the positions of the through-hole and the hole part on the other end side where no protrusion is provided are shifted from each other in the insertion direction of the first attachment member. Accordingly, in the case where the bolt member is inserted and fastened into the through-hole and the hole parts, it is necessary to match the positions of the through-hole and the hole part on the other end side with each other, thus deteriorating the efficiency of the work. On the contrary, the protrusions are provided at the both ends of the cylindrical shape in the vibration-proof apparatus of claim  4 . Accordingly, the positions of the through-hole and the hole parts are not shifted from each other on the one end side and the other end side, and the position of the through-hole can accurately match the positions of the hole parts in a short time. Accordingly, the efficiency of work to insert and fasten the bolt member into the through-hole of the first attachment member and the hole parts drilled at the wall parts can be improved. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0019]      FIG. 1  is a perspective view of a vibration-proof apparatus in a first embodiment of the present invention. 
           [0020]      FIG. 2(   a ) is a front view of the vibration-proof apparatus, and  FIG. 2(   b ) is a side view of the vibration-proof apparatus. 
           [0021]      FIG. 3(   a ) is a partially-enlarged front view of a leg part on the side where a short-axis attachment bracket is arranged,  FIG. 3(   b ) is a partially-enlarged cross-sectional view of the leg part taken along the line IIIb-IIIb of  FIG. 3(   a ),  FIG. 3(   c ) is a partially-enlarged front view of the leg part on the side where a long-axis attachment bracket is arranged, and  FIG. 3(   d ) is a partially-enlarged cross-sectional view of the leg part taken along the line IIId-IIId of  FIG. 3(   c ). 
           [0022]      FIG. 4  is a diagram for showing a state of a resin die immediately after the vibration-proof apparatus is molded. 
           [0023]      FIG. 5(   a ) is a front view of a fixing bracket, and  FIG. 5(   b ) is a cross-sectional view of the fixing bracket taken along the line Vb-Vb shown in  FIG. 5(   a ). 
           [0024]      FIG. 6(   a ) is a front view of the fixing bracket, and  FIG. 6(   b ) is a cross-sectional view of the fixing bracket taken along the line VIb-VIb shown in  FIG. 6(   a ). 
           [0025]      FIG. 7(   a ) is a partially-enlarged front view of a leg part on the side where a short-axis attachment bracket is arranged in a second embodiment,  FIG. 7(   b ) is a partially-enlarged cross-sectional view of the leg part taken along the line VIIb-VIIb of  FIG. 7(   a ),  FIG. 7(   c ) is a partially-enlarged front view of the leg part on the side where a long-axis attachment bracket is arranged, and  FIG. 7(   d ) is a partially-enlarged cross-sectional view taken along the line VIId-VIId of  FIG. 7(   c ). 
           [0026]      FIG. 8(   a ) is a partially-enlarged front view of a leg part on the side where a long-axis attachment bracket is arranged in a modification example, and  FIG. 8(   b ) is a partially-enlarged cross-sectional view of the leg part taken along the line VIIIb-VIIIb of  FIG. 8(   a ). 
           [0027]      FIG. 9  is a partially-enlarged cross-sectional view of the leg part taken along the line IX-IX of  FIG. 8(   b ). 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0028]    Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In the first place, the entire configuration of a vibration-proof apparatus  1  will be described with reference to  FIG. 1  and  FIG. 2 .  FIG. 1  is a perspective view of the vibration-proof apparatus  1  in an embodiment of the present invention,  FIG. 2(   a ) is a front view of the vibration-proof apparatus  1 , and  FIG. 2(   b ) is a side view of the vibration-proof apparatus  1 . It should be noted that the structure of a resin die  60  (see  FIG. 5)  can be simplified by simplifying the split structure of the resin die  60  used for molding the vibration-proof apparatus  1 . 
         [0029]    As shown in  FIG. 1 , the vibration-proof apparatus  1  supports and fixes an engine (not shown) of an automobile so as not to transmit vibration generated from the engine to an automobile body (not shown), and includes, as shown in  FIG. 1 , a pair of a short-axis attachment bracket  50  and a long-axis attachment bracket  51  attached to the automobile body side, a thin elastic member  45  and a thick elastic member  46  made of rubber-like elastic material that are vulcanized and attached to outer circumferential surfaces of the both attachment brackets  50  and  51 , respectively, coupling members  10  made of resin material that include a main body part  11  formed continuously from a leg part  13  and a leg part  13  into which the both elastic members  45  and  46  are pressed, an inner cylinder  30  that is attached on the engine (vibration generator) side, and a vibration-proof base  40  made of rubber-like elastic material through which the inner cylinder  30  is coupled to the main body part  11 . 
         [0030]    As shown in  FIG. 1  and  FIG. 2 , the short-axis attachment bracket  50  and the long-axis attachment bracket  51  are made of steel material, and are attached on the automobile body side as described above. These attachment brackets  50  and  51  have through-holes  50   c  and  51   c , respectively, and are formed in a cylindrical shape. Bolts (not shown) are inserted into the through-holes  50   c  and  51   c , and end surfaces (seating surfaces  50   b  and  51   b ) of the both attachment brackets  50  and  51  are attached on the automobile body side by fastening the bolts. Further, the both attachment brackets  50  and  51  are provided with protrusions  50   a  and  51   a , respectively, that protrude from both end surfaces in the axial direction. It should be noted that the short-axis attachment bracket  50  and the long-axis attachment bracket  51  will be described in more detail with reference to  FIG. 3  and  FIG. 4 . 
         [0031]    As shown in  FIG. 1  and  FIG. 2 , each of the coupling members  10  includes the main body part  11 , a reinforcing rib  12 , and the leg part  13 . The main body part  11  is formed in a rectangular cylindrical shape. The vibration-proof base  40  is arranged on the inner circumferential side of the main body part  11 , and the inner cylinder  30  is vulcanized and attached to the vibration-proof base  40 . Specifically, an outer circumferential surface of the vibration-proof base  40  is coupled to an inner circumferential surface of the main body part  11 , and an outer circumferential surface of the inner cylinder  30  is coupled to an inner circumferential surface of the vibration-proof base  40 . 
         [0032]    Stoppers  13   e  are fixed and attached to both edges of the main body part  11  along the vertical direction. Each of the stoppers  13   e  continues to the vibration-proof base  40 . When large displacement occurs on the engine side, parts (not shown) on the engine side abut on the stoppers  13   e  so as to restrict the displacement. 
         [0033]    An upper wall of the main body part  11  is formed larger in thickness in the vertical direction (the vertical direction of  FIG. 2(   a )) than a lower wall of the main body part  11 , and plural main body-side hollows  11   a  are provided at a wall surface of the upper wall in a recessed manner. Accordingly, the weight of the main body part  11  can be reduced while securing the stiffness of the main body part  11 . 
         [0034]    As shown in  FIG. 1  and  FIG. 2 , each of the reinforcing ribs  12  that are plate-like members used for reinforcing the strength of the main body part  11  in the vertical direction (the vertical direction of  FIG. 2(   a )) protrudes outward from a side wall of the main body part  11 , and is formed so as to continue to the leg part  13 . 
         [0035]    As shown in  FIG. 1  and  FIG. 2(   a ), the leg parts  13  expand from the side walls and the lower wall of the main body part  11  so as to surround the side walls and the lower wall of the main body part  11 , and the thin elastic member  45  and the thick elastic member  46  that are vulcanized and attached to the short-axis attachment bracket  50  and the long-axis attachment bracket  51 , respectively, are pressed into lower portions of the leg parts  13 . As described above, the leg parts  13  are coupled to the side walls and the lower wall of the main body part  11 , so that the leg parts  13  are strongly coupled to the main body part  11 . 
         [0036]    Here, a pair of press-fit holes  13   a  and  13   b  are formed to penetrate the leg parts  13 , and the elastic members  45  and  46  are pressed into the pair of press-fit holes  13   a  and  13   b , respectively (see  FIG. 3 ). It should be noted that the axial directions of the press-fit holes  13   a  and  13   b  are parallel with the axial direction of the inner cylinder  30 . Accordingly, demoldability from the resin die  60  (see  FIG. 4 ) can be secured. 
         [0037]    Further, as shown in  FIG. 2(   a ), first hollow parts  14  are provided at one of wall surfaces (wall surface on the near side of  FIG. 2(   a )) of the leg parts  13  in a recessed manner, and second hollow parts (not shown) are provided at the other of wall surfaces (wall surface on the depth side of  FIG. 2(   a )) of the leg parts  13  in a recessed manner. It should be noted that the first hollow parts  14  and the second hollow parts are formed in the same shape. Thus, only the first hollow parts  14  are illustrated and explained, and the illustration and explanation of the second hollow parts are omitted. 
         [0038]    The first hollow parts  14  are spaces provided at the leg parts  13  so as to reduce the weight of the leg parts  13 , and include upper first hollow parts  14   a  provided at upper portions of the leg parts  13  in a recessed manner and lower front hollow parts  14   b  provided at lower portions of the leg parts  13  in a recessed manner. Each of the upper first hollow parts  14   a  is formed in a parallelogram shape when viewed from the front, and each of the lower first hollow parts  14   b  is formed in a triangle shape when viewed from the front, so that the thicknesses of the wall parts surrounding the both hollow parts  14   a  and  14   b  are made substantially constant. 
         [0039]    As shown in  FIG. 1  and  FIG. 2(   a ), the inner cylinder  30  is made of aluminum alloy, and is formed in a cylindrical shape having a through-hole  30   a . A bolt (not shown) is inserted and fastened into the through-hole  30   a , so that the inner cylinder  30  is coupled on the engine side. The vibration-proof base  40  is a member for absorbing vibration generated on the engine side, and is made of rubber-like elastic material. Gaps  11   b  are formed between the vibration-proof base  40  and an upper inner circumferential surface of the main body part  11  and between the vibration-proof base  40  and a lower inner circumferential surface of the main body part  11 . Accordingly, the spring constant of the vibration-proof base  40  in the vertical direction can be set smaller than that in the horizontal direction. 
         [0040]    Next, with reference to  FIG. 3 , there will be described in detail the leg parts  13  into which the thin elastic member  45  and the thick elastic member  46  that are vulcanized and attached to the outer circumferential surfaces of the short-axis attachment bracket  50  and the long-axis attachment bracket  51 , respectively, are pressed.  FIG. 3(   a ) is a partially-enlarged front view of the leg part  13  on the side where the short-axis attachment bracket  50  is arranged, and  FIG. 3(   b ) is a partially-enlarged cross-sectional view of the leg part  13  taken along the line IIIb-IIIb of  FIG. 3(   a ). Further,  FIG. 3(   c ) is a partially-enlarged front view of the leg part  13  on the side where the long-axis attachment bracket  51  is arranged, and  FIG. 3(   d ) is a partially-enlarged cross-sectional view of the leg part  13  taken along the line IIId-IIId of  FIG. 3(   c ). 
         [0041]    As shown in  FIG. 3 , each of the short-axis attachment bracket  50  and the long-axis attachment bracket  51  has a cylindrical shape whose surface obtained by cutting with a planar surface perpendicular to the axis is in an annular shape, and the seating surfaces  50   b  and  51   b  are formed at both end surfaces of the cylindrical members. Each of the seating surfaces  50   b  and  51   b  is formed in an annular shape, and each of the protrusions  50   a  and  51   a  protrudes from a part of the annular shape in the axial direction (the horizontal direction of  FIG. 3(   b ) and  FIG. 3(   d )). In addition, the through-holes  50   c  and  51   c  are concentrically opened in the middles of the seating surfaces  50   b  and  51   b , respectively. 
         [0042]    As shown in  FIG. 3 , the through-holes  50   c  and  51   c  are formed to penetrate along the axial direction, and are communicated from the one pair of the seating surfaces  50   b  and  51   b  of the short-axis attachment bracket  50  and the long-axis attachment bracket  51  to the other pair of the seating surfaces  50   b  and  51   b  of the short-axis attachment bracket  50  and the long-axis attachment bracket  51 . 
         [0043]    It should be noted that the short-axis attachment bracket  50  and the long-axis attachment bracket  51  are configured in the same shape except that the lengths in the axial direction (the lengths in the horizontal direction of  FIG. 3(   b ) and  FIG. 3(   d )) are different from each other. Specifically, the inner diameter and outer diameter of the short-axis attachment bracket  50  are set at the same dimensions as the inner diameter and outer diameter of the long-axis attachment bracket  51  except that the length of the short-axis attachment bracket  50  in the axial direction is shorter than the length of the long-axis attachment bracket  51  in the axial direction. Further, the protrusions  50   a  are formed in the same shape as the protrusions  51   a.    
         [0044]    Each of the thin elastic member  45  and the thick elastic member  46  is a cylindrical member made of rubber-like elastic material, and cylindrical inner circumferential surfaces thereof are vulcanized and attached to outer circumferential surfaces of the short-axis attachment bracket  50  and the long-axis attachment bracket  51 . In addition, the thin elastic member  45  and the thick elastic member  46  are pressed into the press-fit holes  13   a  and  13   b , respectively, that are formed to penetrate the leg parts  13 . It should be noted that the outer diameter of the thin elastic member  45  is set at a dimension smaller than the outer diameter of the thick elastic member  46  (namely, set at a thinner thickness). Further, the outer diameters of the thin elastic member  45  and the thick elastic member  46  are set at dimensions larger than the inner diameters of the press-fit holes  13   a  and  13   b , respectively, thereby securing the press-fit allowance when being pressed. 
         [0045]    Next, demoldability from the resin die  60  after the vibration-proof apparatus  1  is molded will be described with reference to  FIG. 4 .  FIG. 4  is a diagram for showing a state of the resin die  60  immediately after the vibration-proof apparatus  1  is molded. It should be noted that reference numerals are given only to main constitutional elements, and are not given to the other constitutional elements. 
         [0046]    The resin die  60  includes a first resin die  61  and a second resin die  62 . After the inner cylinder  30  and the vibration-proof base  40  that is vulcanized and attached to the inner cylinder  30  are disposed at the second resin die  62 , the first resin die  61  is clamped to the second resin die  62  to fill (inject) resin material into a cavity formed in the resin die  60 . Accordingly, the resin material is formed integrally with the inner cylinder  30  and the vibration-proof base  40 . Accordingly, the molded product is removed from the resin die  60 , and the thin elastic member  45  and the thick elastic member  46  that are vulcanized and attached to the outer circumferences of the short-axis attachment bracket  50  and the long-axis attachment bracket  51  are pressed into the press-fit holes  13   a  and  13   b  of the leg parts  13 , respectively, so that the vibration-proof apparatus  1  is completed. 
         [0047]    Here, the axial directions of the inner cylinder  30  and the press-fit holes  13   a  and  13   b  of the vibration-proof apparatus  1  are parallel with each other, and thus the middle-sized protruding direction (axial direction) for holding the inner cylinder  30  and the vibration-proof base  40  can be made parallel with the axial directions for forming the press-fit holes  13   a  and  13   b.    
         [0048]    Accordingly, as shown in  FIG. 4 , in the case where the molded product is removed from the resin die  60  after the inner cylinder  30  and the vibration-proof base  40  are placed in the first resin die  61  and the first resin die  61  and the second resin die  62  are clamped to each other to mold the resin material, the first resin die  61  and the second resin die  62  can be removed in the same direction, namely, the direction where the first resin die  61  and the second resin die  62  are vertically separated from each other in  FIG. 4 . 
         [0049]    Thus, the structure of the resin die  60  can be simplified by simplifying the split structure of the resin die  60  used for the vibration-proof apparatus  1 . Further, due to the simple structure of the resin die  60 , the cost of the resin die  60  can be reduced. Furthermore, the number of vibration-proof apparatuses  1  molded from one resin die  60  can be increased. 
         [0050]    In addition, the protruding directions of the protrusion  50   a  and  51   a  provided at the short-axis attachment bracket  50  and the long-axis attachment bracket  51 , respectively, are parallel with the axial directions of the inner cylinder  30  and the press-fit holes  13   a  and  13   b  (see  FIG. 1  to  FIG. 3 ). Accordingly, even in the case where the protrusions  50   a  and  51   a  are provided at the short-axis attachment bracket  50  and the long-axis attachment bracket  51 , respectively, the structure of the resin die  60  can be simplified by simplifying the split structure of the resin die  60 . 
         [0051]    Next, mounting of the vibration-proof apparatus  1  to the body side will be described with reference to  FIG. 5  and  FIG. 6 .  FIG. 5(   a ) is a front view of a fixing bracket  70 , and  FIG. 5(   b ) is a cross-sectional view of the fixing bracket  70  taken along the line Vb-Vb shown in  FIG. 5(   a ). Further,  FIG. 6(   a ) is a front view of the fixing bracket  70 , and  FIG. 6(   b ) is a cross-sectional view of the fixing bracket  70  taken along the line VIb-VIb shown in  FIG. 6(   a ). Each of  FIG. 6(   a ) and  FIG. 6(   b ) illustrates a state in which the long-axis attachment bracket  51  of the vibration-proof apparatus  1  is mounted to the fixing bracket  70 . It should be noted that the configuration of the fixing bracket by which the short-axis attachment bracket  50  is attached on the automobile body side is the same as the configuration of the fixing bracket  70  except that the facing interval of wall parts  70   b  is different, and thus the explanation thereof is omitted. 
         [0052]    As shown in  FIG. 5 , the fixing bracket  70  made of steel material is a bracket attached and fixed on the automobile body side, and is bent to be formed in a U-shape when viewed from the side. Specifically, the fixing bracket  70  includes a plate-like bottom plate  70   a  deposited on the automobile body side, and a pair of plate-like wall parts  70   b  that are continuously provided from the bottom plate to stand at a predetermined interval. 
         [0053]    As shown in  FIG. 5(   b ), each of upper end surfaces  70   d  located at upper portions of the wall parts  70   b  is parallel with the bottom plate  70   a , and is formed in a planar surface. Further, hole parts  70   c  are concentrically formed at the respective wall parts  70   b  when viewed from the front, and bolts (not shown) for fastening the wall parts  70   b  to the long-axis attachment bracket  51  are inserted into the respective hole parts  70   c.    
         [0054]    As shown in  FIG. 6 , in the case where the long-axis attachment bracket  51  is fastened to the fixing bracket  70 , the attachment bracket  51  is first inserted between the wall parts  70   b  that face each other. At this time, when the long-axis attachment bracket  51  is inserted and moved by a predetermined amount, the protrusions  51   a  provided at the both seating surfaces  51   b  of the long-axis attachment bracket  51  abut on the respective upper end surfaces  70   d . Accordingly, insertion and movement of the long-axis attachment bracket  51  into the upper end surfaces  70   d  are restricted by the respective protrusions  51   a , and the position of the through-hole  51   c  of the long-axis attachment bracket  51  matches the positions of the hole parts  70   c . Accordingly, the position of the through-hole  51   c  can accurately match the positions of the hole parts  70   c  in a short time. Thus, the efficiency of work to insert and fasten a bolt (not shown) into the through-hole  51   c  and the hole parts  70   c  can be improved. 
         [0055]    Here, in a vibration-proof apparatus in which the protrusion  51   a  is provided only at one end surface of the long-axis attachment bracket  51  unlike the vibration-proof apparatus  1  of the application, the positions of the through-hole  51   c  and the hole part  70   c  on the one end surface side can match each other. However, the positions of the through-hole  51   c  and the hole part  70   c  on the other end surface side where no protrusion  51   a  is provided are shifted from each other in the insertion direction. Accordingly, in the case where the bolt (not shown) is inserted and fastened into the through-hole  51   c  and the hole parts  70   c , it is necessary to match the positions of the through-hole  51   c  and the hole part  70   c  on the other end surface side with each other, thus deteriorating the efficiency of the work. 
         [0056]    On the contrary, the protrusions  51   a  are provided at the both end surfaces of the long-axis attachment bracket  51  in the vibration-proof apparatus  1  of the application. Accordingly, the positions of the through-hole  51   c  and the hole parts  70   c  are not shifted from each other in the insertion direction on the one end surface side and the other end surface side, and the position of the through-hole  51   c  can accurately match the positions of the hole parts  70   c  in a short time. Accordingly, in the vibration-proof apparatus  1  of the application, the efficiency of work to insert and fasten the bolt into the through-hole  51   c  and the hole parts  70   c  can be improved. 
         [0057]    In addition, as shown in  FIG. 6(   a ), the upper end surfaces  70   d  abutting on the protrusions  51   a  are in a planar shape, and the surfaces of the protrusions  51   a  abutting on the upper end surfaces  70   d  are also in a planar shape. Accordingly, even if the positions of the through-hole  51   c  and the hole parts  70   c  are shifted from each other in the horizontal direction of  FIG. 6(   a ) when the protrusions  51   a  abut on the upper end surfaces  70   d  due to the processing tolerance of the through-hole  51   c  and the hole parts  70   c , or the protrusions  51   a  and the upper end surfaces  70   d , the shift can be easily adjusted by sliding the long-axis attachment bracket  51 . Accordingly, the position of the through-hole  51   c  can accurately match the positions of the hole parts  70   c  in a short time. 
         [0058]    As described above, according to the vibration-proof apparatus  1  of the embodiment, the inner cylinder  30  attached on the engine (vibration generator) side is coupled to the main body part  11  of the coupling members  10  through the vibration-proof base  40 , and the short-axis attachment bracket  50  and the long-axis attachment bracket  51  attached on the automobile body side are coupled to the leg parts  13  of the coupling members  10  through the thin elastic member  45  and the thick elastic member  46 , respectively, so that a mass-spring system can be configured while the coupling members  10  serve as masses (mass members) and the vibration-proof base  40  and the both elastic members  45  and  46  serve as springs. 
         [0059]    In this case, because the thin elastic member  45  and the thick elastic member  46  according to the embodiment are different from each other in the spring constant, it is not necessary to change the arrangement positions of the short-axis attachment bracket  50  and the long-axis attachment bracket  51 , and the vibration mode can be changed. Specifically, for example, the rubber hardness of each of the thin elastic member  45  and the thick elastic member  46  is changed or the dimension (namely, the press-fit allowance) of the thickness of each rubber is changed, so that the vibration mode can be changed by individually adjusting the spring constant of each of the elastic members  45  and  46 . Thus, it is not necessary to change the shape of the resin die  60  in order to adjust the arrangement positions of the short-axis attachment bracket  50  and the long-axis attachment bracket  51 , so that the vibration mode of the vibration-proof apparatus  1  can be easily changed. 
         [0060]    As a result, in the case where the vibration-proof apparatus  1  is used as a dynamic damper (vibration damper) for suppressing the vibration on the automobile body side or the engine (vibration generator) side, tuning work for adjusting the unique vibration of the dynamic damper to the resonance frequency on the automobile body side can be easily performed at a low cost. On the other hand, even if the vibration-proof apparatus  1  is not used as the dynamic damper to suppress the resonance, the work for adjusting the vibration mode of the vibration-proof apparatus  1  to suppress the resonance can be easily performed at a low cost as similar to the above. 
         [0061]    Further, as the vibration-proof apparatus  1  in the embodiment, if the thin elastic member  45  and the thick elastic member  46  are different from each other in the spring constant, the position of the center of the gravity of the mass member (namely, the mass of the coupling members  10 ) can be shifted from the center lines of the springs (springs configured by the thin elastic member  45  and the thick elastic member  46 ) in the mass-spring system. Thus, in the case where the vibration-proof apparatus  1  is used as the dynamic damper (vibration damper), plural vibration modes can be continuously generated. 
         [0062]    Next, a second embodiment will be described with reference to  FIG. 7 . In the first embodiment, there has been described a case in which the thin elastic member  45  and the thick elastic member  46  are pressed into the press-fit holes  13   a  and  13   b  of the leg parts  13 , respectively. However, in the second embodiment, a thin elastic member  245  and a thick elastic member  246  are inserted into leg parts  213  for molding. It should be noted that the same constitutional elements as those in the first embodiment are given the same reference numerals, and the explanations thereof are omitted. 
         [0063]      FIG. 7(   a ) is a partially-enlarged front view of the leg part  213  on the side where the short-axis attachment bracket  50  is arranged in the second embodiment, and  FIG. 7(   b ) is a partially-enlarged cross-sectional view of the leg part  213  taken along the line VIIb-VIIb of  FIG. 7(   a ). Further,  FIG. 7(   c ) is a partially-enlarged front view of the leg part  213  on the side where the long-axis attachment bracket  51  is arranged, and  FIG. 7(   d ) is a partially-enlarged cross-sectional view of the leg part  213  taken along the line VIId-VIId of  FIG. 3(   c ). 
         [0064]    As shown in  FIG. 7 , each of the thin elastic member  245  and the thick elastic member  246  is a cylindrical member made of rubber-like elastic material, and cylindrical inner circumferential surfaces thereof are vulcanized and attached to outer circumferential surfaces of the short-axis attachment bracket  50  and the long-axis attachment bracket  51 . In the second embodiment, the thin elastic member  245  and the thick elastic member  246  are inserted into the leg parts  213  for molding. 
         [0065]    Specifically, in the second embodiment, after the inner cylinder  30  and the vibration-proof base  40  that is vulcanized and attached to the inner cylinder  30 , and the attachment brackets  50  and  51  and the elastic members  245  and  246  that are vulcanized and attached to the attachment brackets  50  and  51 , respectively, are disposed in the second resin die  62 , the first resin die  61  is clamped to the second resin die  62  to fill (inject) resin material into the cavity formed in the resin die  60  (see  FIG. 4 ). Accordingly, the resin material is formed integrally with the vibration-proof base  40  and the elastic members  245  and  246 , and the vibration-proof apparatus is completed. 
         [0066]    It should be noted that the outer diameter of the thin elastic member  245  is set at a dimension smaller than the outer diameter of the thick elastic member  246  (namely, set at a thinner thickness). 
         [0067]    The present invention has been described above on the basis of the embodiments. However, it can be easily understood that the present invention is not limited to the above-described embodiments and can be variously changed and modified without departing from the scope of the present invention. 
         [0068]    In the vibration-proof apparatus  1  according to each embodiment, each of the protrusions  50   a  and  51   a  is formed in a rectangular solid shape. However, the present invention is not limited to this. Specifically, each of the protrusions  50   a  and  51   a  may be formed in a columnar shape (for example, each of the protrusions  50   a  and  51   a  may be separately formed in a pin shape to be punched into the seating surfaces  50   b  and  51   b ), or each of the protrusions  50   a  and  51   a  may be formed in a triangle pole shape. Even in the case of this configuration, the protrusions  50   a  and  51   a  can restrict the insertion and movement of the attachment brackets  50  and  51  into the upper end surfaces  70   d , so that the positions of the through-holes  50   c  and  51   c  can match the positions of the hole parts  70   c.    
         [0069]    Further, in the vibration-proof apparatus  1  according to each embodiment, the upper end surfaces  70   d  abutting on the protrusions  50   a  and  51   a  are formed in a planar shape. However, the present invention is not limited to this. Specifically, rectangular grooves into which the protrusions  50   a  and  51   a  can be fitted are provided at the upper end surfaces  70   d , and the protrusions  50   a  and  51   a  may be inserted into the grooves. Further, V-shaped grooves are provided at the upper end surfaces  70   d , each of the protrusions  50   a  and  51   a  is formed in a shape matching the V-shaped groove (for example, each of the protrusions  50   a  and  51   a  is formed in a triangle pole shape), and the protrusions  50   a  and  51   a  may be inserted into the V-shaped grooves. 
         [0070]    In the cases of the configurations, the insertion and movement of the attachment brackets  50  and  51  into the upper end surfaces  70   d  can be restricted, and the movement of the attachment brackets  50  and  51  in the horizontal direction (the movement in the horizontal direction of  FIG. 6(   a )) can be restricted. Accordingly, the positions of the through-holes  50   c  and  51   c  can accurately match the positions of the hole parts  70   c  in a short time. Thus, the efficiency of work to insert and fasten the bolts (not shown) into the through-holes  50   c  and  51   c  and the hole parts  70   c  can be further improved. 
         [0071]    Further, in the above-described first embodiment, there has been described a case in which the thin elastic member  45  pressed into the leg part  13  (press-fit hole  13   a ) of one of the pair of leg parts  13  is different in outer diameter from the thick elastic member  46  pressed into the other leg part  13  (press-fit hole  13   b ) (specifically, the thin elastic member  45  and the thick elastic member  46  are different in thickness from each other because the attachment brackets  50  and  51  are the same in outer diameter). However, the present invention is not necessarily limited to this. It is obvious that the elastic member pressed into the leg part  13  (press-fit hole  13   a ) of one of the pair of leg parts  13  may be the same in outer diameter as the elastic member pressed into the other leg part  13  (press-fit hole  13   b ). 
         [0072]    Specifically, on the assumption that the press-fit hole  13   a  of one of the pair of leg parts  13  is formed different in inner diameter from the press-fit hole  13   b  of the other of the pair of leg parts  13 , even in the case where the elastic member (and the attachment member) pressed into the press-fit hole  13   a  of one of the pair of leg parts  13  and the elastic member (and the attachment member) pressed into the press-fit hole  13   b  of the other of the pair of leg parts  13  are configured in the same dimension and characteristic, the spring constant can be made different by changing each press-fit allowance. As a result, the elastic member (and the attachment member) pressed into the press-fit hole  13   a  of one of the pair of leg parts  13  and the elastic member (and the attachment member) pressed into the press-fit hole  13   b  of the other of the pair of leg parts  13  can be used as common members. Thus, the cost of the parts can be reduced to reduce the cost of the product as the whole vibration-proof apparatus. 
         [0073]    Further, in each embodiment, there has been described a case in which each of the short-axis attachment bracket  50  and the long-axis attachment bracket  51  is formed in a cylindrical shape whose cross-section is in an annular shape. However, it is obvious that the present invention is not limited to this, but the shape may be different. A modification example of the different shape will be described with reference to  FIG. 8  and  FIG. 9 . 
         [0074]      FIG. 8(   a ) is a partially-enlarged front view of the leg part  13  on the side where a long-axis attachment bracket  351  is arranged in the modification example, and  FIG. 8(   b ) is a partially-enlarged cross-sectional view of the leg part  13  taken along the line VIIIb-VIIIb of  FIG. 8(   a ). Further,  FIG. 9  is a partially-enlarged cross-sectional view of the leg part  13  taken along the line IX-IX of  FIG. 8(   b ). 
         [0075]    As shown in  FIG. 8  and  FIG. 9 , in the long-axis attachment bracket  351  of the modification example, an extension part  351   d  whose cross-section is in a rectangular shape extends outward (upward in  FIG. 9 ) from an outer circumferential surface of the cylindrical shape whose cross-section is in an annular shape. Accordingly, a seating surface  351   b  having an annular area and a rectangular area protruding from the annular area is formed at an end surface of the long-axis attachment bracket  351 . 
         [0076]    Further, the long-axis attachment bracket  351  includes protrusions  351   a  protruding from the both seating surfaces  351   b  in parallel with the axial direction, and each protrusion  351   a  protrudes from the rectangular area protruding outward from the annular area. Specifically, each protrusion  351   a  is provided at a position (a position where the annular shape is not interrupted) where the annular shape of the seating surface  351   b  is maintained. With this arrangement, an area of each seating surface  351   b  that is pressed into and brought into contact with the wall plate  70   b  (see  FIG. 6 ) by fastening a bolt can be secured to a regulated area. Thus, the pressure from the wall plates  70   b  when fastening the bolt can be dispersed by the seating surfaces  351   b  and as a result, deformation of the seating surfaces  351   b  and wall plates  70   b  can be prevented. 
         [0077]    Further, the extension part  351   d  is provided at the outer circumferential surface of the long-axis attachment bracket  351 , so that attachment strength can be secured by enlarging an attachment area with a thick elastic member  346 . Accordingly, since the both can be strongly integrated, so that the long-axis attachment bracket  351  can be prevented from dropping off from the thick elastic member  346  in the axial direction. Further, in the case where rotational force about the axis is applied to the long-axis attachment bracket  351 , the long-axis attachment bracket  351  can be prevented from rotating about the axis relative to the thick elastic member  346 . 
         [0078]    Further, in each embodiment, there has been described a case in which the outer diameters of the short-axis attachment bracket  50  and the long-axis attachment bracket  51  are set at the same value. However, it is obvious that the present invention is not limited to this, but the outer diameters may be different from each other. As similar to the above, the lengths of the thin elastic members  45  and  245  and the thick elastic members  46 ,  246 , and  346  are set at the same value in the axial direction (for example, the lengths in the horizontal direction of  FIG. 3(   b ) and  FIG. 3(   d )). However, it is obvious that the lengths may be different from each other in the axial direction. Specifically, the thin elastic members  45  and  245  and the thick elastic members  46 ,  246 , and  346  can be made different in spring constant by combining one or more of the rubber shape (dimension of the thickness and the length in the axial direction), the rubber hardness, the rubber material, and the press-fit allowance. 
         [0079]    In the above-described first embodiment, there has been described a case in which the thin elastic member  45  and the thick elastic member  46  are pressed into the both leg parts  13 . In addition, in the second embodiment, there has been described a case in which the thin elastic member  245  and the thick elastic member  246  are inserted into the both leg parts  213  for molding. However, the present invention is not necessarily limited to this, the thin elastic member  45  or the thick elastic member  46  may be pressed into one of the both leg parts  13  and  213 , and the thin elastic member  245  or the thick elastic member  246  may be inserted into the other of the leg parts  13  and  213  for molding. 
         [0080]    In each embodiment, there has been described a case in which two first attachment brackets  51  are provided. However, it is obvious that the present invention is not necessarily limited to this, but three or more first attachment brackets  51  may be provided. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1  vibration-proof apparatus 
           50  short-axis attachment bracket (first attachment member) 
           51 ,  351  long-axis attachment bracket (first attachment member) 
           13 ,  213  leg part 
           11  main body part 
           10  coupling member 
           30  inner cylinder (second attachment member) 
           40  vibration-proof base 
           45 ,  245  thin elastic member (elastic member) 
           46 ,  246 ,  346  thick elastic member (elastic member) 
           50   c ,  51   c  through-hole 
           13   a ,  13   b  press-fit hole 
           50   a ,  51   a ,  351   a  protrusion 
           70   b  wall part 
           70   c  hole part 
           70   d  upper end surface (end portion of wall part)