Abstract:
A disclosed vibration insulating device, which is interposed between a vibrating body and a mounting body, includes a fluid chamber fluid filled with fluid, an elastic support partly defining the fluid chamber, a movable member partly defining the fluid chamber, a supporting member supporting the movable member, an actuator opposed to the movable member, the actuator that generates displacement force to displace the movable member, and a gap holding member disposed between the supporting member and the actuator. The gap holding member maintains a gap between the actuator and the movable member. Also, according to a disclosed assembly method of the vibration insulating device, the movable member is supported so as to oppose the actuator by using the supporting member and the gap holding member such that it is capable of being displaced with respect to the actuator. Here, in the method, the gap holding member is positioned between the movable member and the actuator.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a vibration insulating device which mounts a vibrating body such as an engine on a mounting body such as a vehicle body while insulating vibration and an assembly method thereof, and particularly to a vibration insulating device in which a fluid chamber accommodating fluid is defined by an elastic support disposed between the vibrating body and the mounting body so as to change a volume of the fluid chamber actively, thereby reducing vibration transmission rate by using that active mounting force and an assembly method thereof. 
     Japanese Patent Application Laid-Open No. H9-250590 (Japanese Patent Application No. H8-59219) discloses a vibration insulating device having a fluid chamber accommodating fluid so as to change a volume of the fluid chamber actively. 
     SUMMARY OF THE INVENTION 
     Because in a conventional vibration insulating device having a fluid chamber in which a volume of the fluid chamber is changed actively, a movable member which can be vibrated when the volume of the fluid chamber is changed is used, a gap between the movable member and its surrounding part like a connecting member which communicates with a mounting body like a vehicle body needs to be maintained accurately in a direction in which the stroke of the vibration is changed. For example, in a case that an electromagnetic actuator is used to vibrate the movable member, the movable member is often so designed that the vibration stroke thereof with respect to the electromagnetic actuator is changed. Therefore, it is important to apply a magnetic force of the electromagnetic actuator appropriately to the movable member and specify the gap between the movable member and the electromagnetic actuator accurately so as to make the movable member vibrate at a necessary stroke. The importance of maintaining the gap between the movable member and the electromagnetic actuator accurately is increased as the vibration insulation characteristic required for the vibration insulating device is increased. 
     However, according to consideration of the present inventors and the like, because the gap between the movable member and the electromagnetic actuator positioned on the side of the mounting body is affected by error in dimensions of the components disposed around the movable member and error in characteristic such as resilient force and magnetic force, it is very difficult to settle the gap between the movable member and the electromagnetic actuator within a predetermined strict allowance at the time of assembly of the vibration insulating device. Although, as the countermeasure, minimizing the error in dimension of the components and error in physical characteristic or the like can be considered, this countermeasure is not favorable in a case of mass production when cost or the like of the vibration insulating device are taken into account. If such a condition regarding mass production or the like of the vibration insulating device are considered, an effective countermeasure on assumption that the gap between the movable member and the electromagnetic actuator does not come within a predetermined allowance at a single assembly is demanded. 
     In a case that mass production or the like of the vibration insulating device are considered, it can be considered to first measure the gap between the movable member and the electromagnetic actuator at the time of assembly, previously prepare some kind of adjusting part and then make adjustment with the adjusting part so that the gap between the movable member and the electromagnetic actuator comes into its allowance. Although such an adjusting part is desired to be disposed in the vicinity of the movable member and electromagnetic actuator in viewpoints of accuracy of the adjustment, generation of an excessive step such as a step for disassembling already installed components should be avoided if mass production or the like are considered. Such an excessive disassembly process for the components which is essentially not necessary may introduce a new error factor at the time of reassembly or damage the components at worst, therefore the disassembly process should be eliminated in any case. 
     The present invention has been achieved based on the considerations described above by the inventors and the like, and therefore, an object of the invention is to provide a vibration insulating device including a movable member positioned accurately as required to ensure a high vibration insulation characteristic, having a high suitability to mass production at the time of assembly and in which a necessity of disassembling the already installed components of the vibration insulating device is eliminated, and an assembly method thereof. 
     To achieve the above object, the present invention provides a vibration insulating device, which is interposed between a vibrating body and a mounting body, includes a fluid chamber fluid filled with fluid, an elastic support partly defining the fluid chamber, a movable member partly defining the fluid chamber, a supporting member supporting the movable member, an actuator opposed to the movable member, the actuator that generates displacement force to displace the movable member, and a gap holding member disposed between the supporting member and the actuator. Here the gap holding member maintains a gap between the actuator and the movable member. 
     In other words, such a vibration insulating device includes a fluid chamber filled with fluid, an elastic support partly defining the fluid chamber, a movable member partly defining the fluid chamber, means for supporting the movable member, means for displacing the movable member, and position adjusting means, provided between the means for displacing and the elastic support, for adjusting a gap between the movable member and the means for displacing. 
     On the other hand, the assembly method of the vibration insulating device of the present invention includes a step of preparing an elastic support connecting to a vibrating body and partly defining a fluid chamber, a step of preparing a movable member partly defining the fluid chamber, a step of preparing a supporting member supporting the movable member, a step of preparing an actuator generating force to displace the movable member and connecting to a mounting body, a step of preparing a gap holding member maintaining a gap between the movable member and the actuator, a step of supporting the movable member with the supporting member and the gap holding member in such a manner that the movable member is capable of being displaced and opposes the actuator. The gap holding member is positioned between the supporting member and the actuator. The assembly method further comprises a step of defining a fluid chamber accommodating a fluid with the elastic support and the movable member, and a volume of the fluid chamber is capable of being varied by a displacement of the movable member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic side view showing a vehicle to which a vibration insulating device according to a first embodiment of the present invention and an assembly method thereof are applied; 
     FIG. 2 is a sectional view of the vibration insulating device according to the first embodiment; 
     FIG. 3 is a partially sectional view showing an assembly part and gap holding member of the vibration insulating device of the first embodiment; and 
     FIG. 4 is a partially sectional view showing a supporting ring of the vibration insulating device according to a second embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
     First of all, a vibration insulating device and an assembly method according to a first embodiment of the present invention will be described with reference to FIGS. 1-3. 
     As shown in FIG. 1, in a vehicle  10 , an engine (vibrating body)  17  is mounted to a vehicle body (mounting body)  18  constituted of suspension members or the like through a vibration insulating device (active engine mount)  20  capable of generating a force so as to reduce vibration transmitted from the engine  17  to the vehicle body  18  (which will be referred to as “active mounting force” hereinafter) in accordance with a driving signal. Actually, there are a plurality of engine mounts each of which generates passive mounting force depending on a relative displacement between the engine  17  and the vehicle body  18  in addition to the vibration insulating device  20 , between the engine  17  and the vehicle body  18 . As the passive engine mount, for example, a normal engine mount for mounting a load with a rubber-like resilient body, a known fluid charging type mount insulator in which a fluid is charged inside of a resilient body such as a rubber so as to generate a damping force or the like are available. 
     FIG. 2 shows a structure of the vibration insulating device  20 . A device case  43  contains mount parts such as an outside cylinder  34 , an orifice component  36 , an inside cylinder  37 , an elastic support  32  or the like. Below these mount parts, there are installed an electromagnetic actuator  52  which forms a part of partition wall of a main fluid chamber and displaces a resiliently mounted movable member in a direction in which a volume of the main fluid chamber is changed and a load sensor  64  which detects a vibration status of the vehicle body  18 . 
     Namely, the vibration insulating device  20  of this embodiment contains an engine side connecting member  30  in which a connecting bolt  30   a  is fixed such that it faces upward. Below this engine side connecting member  30  is fixed a hollow cylinder body  30   b  having an inverse trapezoidal section. 
     On a lower side of the engine side connecting member  30  is fixed the elastic support  32  by vulcanized adhering by use of curing agent so as to cover the surfaces of the lower side of the engine side connecting member  30  and the hallow cylinder body  30   b . This elastic support  32  is a substantially cylindrical resilient body which is inclined gradually downward from its center portion toward its peripheral portion. A hollow portion  32   a  having a mountainous section is formed inside of the elastic support  32 . A thin-shaped bottom end portion of the elastic support  32  is fixed by vulcanized adhering by use of curing agent with an inside peripheral surface of the orifice component  36  in which an axis center P 1  (hereinafter referred to as mount axis) is coaxial with respect to the hollow cylinder body  30   b . Here, the mount axis P 1  is a central axis of the vibration insulating device  20  and substantially corresponding to a vibrating body mounting direction (in this case, upward/downward direction in FIG.  2 ). 
     The orifice component  36  is a member in which a small-diameter cylinder portion  36   c  is formed continuously between a upper end cylinder portion  36   a  and a lower end cylinder portion  36   b  each having the same outside diameter so as to produce an annular concave portion on its outside surface. Although not shown, an opening portion is formed in the small-diameter cylinder portion  36   c  so that inside and outside of the orifice component  36  communicate with each other through this opening portion. 
     The outside cylinder  34  is fit to outside of the orifice component  36  and this outside cylinder  34  has the same inside diameter as the outside diameter of the upper end cylinder portion  36   a  and lower end cylinder portion  36   b  of the orifice component  36 . The length in the axial direction of the outside cylinder  34  is the same as that of the orifice component  36 . An opening portion  34   a  is formed in this outside cylinder  34 . An outside periphery of a diaphragm  42  constituted of rubber made thin film resilient body is adhered to an edge portion of the opening portion  34   a  so as to close the opening portion  34   a  such that the diaphragm  42  is bent inward of the outside cylinder  34 . 
     When the outside cylinder  34  having the above described structure is fit to outside of the orifice component  36  so as to surround the annular concave portion, an annular space is defined in the circumferential direction between the outside cylinder  34  and the orifice component  36  and then the diaphragm  42  is disposed in that annular space in a condition that it is bent as described above. 
     The inside cylinder  37  fit to inside of the orifice component  36  includes a smallest-diameter cylinder portion  37   a  formed to be smaller than the small-diameter cylinder portion  36   c  of the orifice component  36 , and annular portions  37   b  and  37   c  are formed at upper and lower end portions of the smallest-diameter cylinder portion  37   a  so as to be directed outward in the diameter direction. The annular portion  37   b  at the upper end is formed such that the outside diameter thereof is slightly smaller than the small-diameter cylinder portion  36   c  of the orifice component  36 . The annular portion  37   c  at the lower end is formed so as to be smaller than the lower end cylinder portion  36   b  of the orifice component  36 , and a second opening portion  37   d  is formed in the smallest-diameter cylinder portion  37   a.    
     As for the device case  43 , an upper end caulking portion  43   a  having a circular opening portion having a diameter smaller than the outside diameter of the upper end cylinder portion  36   a  is formed at its upper end portion, and its main body continuous from this upper end caulking portion  43   a  has a cylinder shape extended up to its bottom end opening portion so as to have the same inside diameter as the outside diameter of the outside cylinder  34  (a shape indicated by broken lines at the bottom end opening portion in FIG.  2 ). 
     Then, the outside cylinder  34  in which the elastic support  32 , the orifice component  36 , the inside cylinder  37  and the diaphragm  42  are integrated therewith is inserted into inside of the device case  43  from its bottom end opening portion and by making the upper end portion of the outside cylinder  34  and the orifice component  36  into contact with a bottom surface of the upper end caulking portion  43   a , they are disposed inside of the device case  43 . 
     An air chamber  42   c  is defined in a space surrounded by the inside surface of the device case  43  and diaphragm  42 . An air vent hole  43   a  is formed at a position facing this air chamber  42   c , and the air chamber  42   c  communicates with the atmosphere through this air vent hole  43   a.    
     A cylindrical spacer  70  is fit to a lower portion of the device case  43 , a movable member  78  is disposed at an upper portion of this spacer  70 , and an electromagnetic actuator  52  is disposed at a lower portion of the spacer  70 . 
     That is, the spacer  70  is a member in which a diaphragm  70   c  constituted of a rubber made thin film resilient body is fixed between an upper cylindrical body  70   a  and a lower cylindrical body  70   b  by vulcanized adhering. 
     The electromagnetic actuator  52  comprises a cylindrical yoke  52   a , a circular excitation coil  52   b  embedded at the side of an upper end surface of the yoke  52  and a permanent magnet  52   c  fixed to a upper center portion of the yoke  52   a  such that its poles are directed up and down. The aforementioned yoke  52   a  comprises an upper yoke member  53   a  and a lower yoke member  53   b , which are two divisions thereof in the vertical direction in FIG.  2 . Then, a lower circumference of the upper yoke member  53   a  and a upper circumference of the lower yoke member  53   b  are ground off so as to form a concave portion  52   d  continuous in its circumferential direction. Then, a diaphragm  70   c  of the spacer  70  is bent toward the aforementioned concave portion  52   d . An air chamber  70   d  is defined in a space surrounded by an inner surface of the device case  43  and the diaphragm  70   c , and an air vent hole  43   b  is formed at a position facing this air chamber  70   d  so that the air chamber  70   d  communicates with the atmosphere thorough this air vent hole  43   b . A load sensor  64  is disposed between the bottom surface of the yoke  52   a  and a lid member  62  provided with vehicle side connecting bolts  60  so as to detect a residual vibration necessary for control to reduce vibration. Although as the load sensor  64 , a piezoelectric element, magnetostrictor, strain gauge and the like are available, the piezoelectric element is used in this embodiment. A detection result of this sensor is supplied to a controller  25  as a residual vibration signal “e” as shown in FIG.  1 . 
     On the other hand, a seal ring  72  for fixing a sealing elastic member  86 , a supporting ring  74  as a retainer for supporting a leaf spring and a gap holding or maintaining/setting ring  76  are disposed coaxially with the mount axis P 1  of vibrating body mounting direction in a upper portion of the inside of the spacer  70 , and further, a movable member  78  capable of being displaced in the up and down direction is disposed inside of these rings. The seal ring  72 , supporting ring  74  and gap holding ring  76  are ring members having the same outside diameter. These rings are fit firmly inside the upper cylindrical body  70   a  of the spacer  70  and the inner diameter of the upper cylindrical body  70   a  is set to the same as the outside diameters of the seal ring  72 , supporting ring  74  and gap holding ring  76 . 
     The movable member  78  comprises a partition wall forming member  78 A formed in circular shape coaxial with the mount axis P 1  and a magnetic path forming member  78 B formed in circular shape coaxial with the mount axis P 1  having a diameter larger than that of the partition wall forming member  78 A. A bolt hole  80   a  is formed in the axis of the partition wall forming member  78 A located at a far side with respect to the electromagnetic actuator  52 . Then, by making a movable member bolt  80  pass through the magnetic path forming member  78 B located at a near side with respect to the electromagnetic actuator  52  and screwing with the bolt hole  80   a , the partition wall forming member  78 A is integrated with the magnetic path forming member  78 B. 
     Further, on an outer edge of the magnetic path forming member  78 B is fixed a stopper member  78 C constituted of a ring-like rubber resilient body so as to prevent a direct contact between the magnetic path forming member  78 B and the electromagnetic actuator  52 . 
     To reduce the size of the vibration insulating device  20  in its diameter direction, an outside diameter L 1  of the magnetic path forming member  78 B is set to be larger than an inside diameter L 2  of the supporting ring  74 . Such a structure is one of important elements for achieving the vibration insulating device  20  having a sufficient performance while securing a freedom of layout in a present situation in which restrictions on a design layout of peripheral components of the engine  17  or the like in an engine room of the vehicle  10  have specifically increased. 
     A constricted portion  79  which is continuous like a ring is defined between the partition wall forming member  78 A and the magnetic path forming member  78 B. A leaf spring  82  which is a resilient member for supporting the movable member  78  resiliently is accommodated in this constricted portion  79 . That is, the leaf spring  82  is a disc-shaped member coaxial with the mount axis P 1  in which a hole portion is formed in the center thereof. An inner peripheral portion of this leaf spring  82  supports a center portion of the bottom side of the partition wall forming member  78 A from lower side of the partition wall forming member  78 A through a free end. An outer peripheral portion of the leaf spring  82  is supported by a convex-shaped ring  74   a  formed along an inner peripheral surface of the supporting ring  74  from a lower side of the leaf spring  82  trough free end. Consequently, the movable member  78  is resiliently supported by the device case  43  trough the leaf spring  82 . 
     In the partition wall forming member  78 A, a partition wall portion  80   c , which is thin and faces a fluid chamber  84 , and an annular rib  80   b  which protrudes upward from an outer periphery of the partition wall portion  80   c  are formed. Then, the fluid chamber  84  is formed by a top face of the partition wall forming member  78 , a bottom face of the elastic support  32  and an inside peripheral surface of the inside cylinder  37  so that fluid is contained in this fluid chamber  84 . To prevent a leakage of the fluid from the fluid chamber  84  to the side of the constricted portion  79  accommodating the leaf spring  82 , a sealing elastic member  86  is provided between an outer periphery of the partition wall forming member  78 A and an inner periphery of the seal ring  72 . 
     The aforementioned sealing elastic member  86  is constituted of a ring-like rubber resilient member and its resilient deformation allows the movable member  78  to be displaced vertically relative to the seal ring  72  and the device case  43  in FIG.  2 . 
     Here, a gap H provided between the permanent magnet  52 C of the electromagnetic actuator  52  and the magnetic path forming member  78 B of the movable member  78  is set to a predetermined length by making both of a so-called assembly part, in which the movable member  78 , seal ring  72 , a sealing elastic member  86 , a leaf spring  82  and a supporting ring  74  are previously integrated, and the gap holding ring  76  into contact with a top surface of the yoke  52   a.    
     As shown in FIG. 3, the partition wall forming member  78 A and the magnetic path forming member  78 B of the movable member  78  are connected with a movable member bolt  80  in such a condition that the leaf spring  82  and the convex-shaped ring  74   a  of the supporting ring  74  are positioned between them. The sealing elastic member  86  is fixed between the seal ring  72  disposed on the supporting ring  74  and the partition wall forming member  78 A. In this manner, the assembly part is formed. After the gap holding ring  76  is disposed below this assembly part, it is set on a top end of the yoke  52   a  and whether or not the gap H is within a predetermined allowance is checked. At this time, if the measured gap H 2  is out of the allowance of the predetermined gap H, a new gap holding ring  76  having a different height from the currently used gap holding ring  76  is disposed below the assembly part instead and selection of such a new gap holding ring  76  is repeated until the gap H surely comes into the predetermined allowance. Meanwhile, this measurement is conducted at four points which are symmetrical relative to the mount axis P 1 . 
     In the mean time, the excitation coil  52   b  of the electromagnetic actuator  52  generates a predetermined electromagnetic force depending on a driving signal “y” which is a current supplied from the controller  25  shown in FIG.  1 . The controller  25  comprises a microcomputer, necessary interface circuit, A/D converter, D/A converter, amplifier, memory medium such as ROM and RAM or the like, and generates and outputs the driving signal “y” to the vibration insulating device  20  so as to produce an active mounting force in the vibration insulating device  20  for reducing the vibration generated by the engine  17 . 
     In the case of reciprocating 4-cylinder, 4-cycle engine, for example, the idling vibration or the indistinct sound vibration generated from the engine  17  are produced mainly because engine vibration which is a so-called engine revolution secondary component is transmitted to the vehicle body  18 . Thus, if the driving signal “y” is produced synchronously with that engine revolution secondary component, the vibration of the vehicle body  18  can be reduced. Therefore, according to this embodiment, a pulse signal generator  19  which produces an impulse signal synchronously with a rotation of a crank shaft of the engine  17  (e.g., in the case of the reciprocating 4-cylinder engine, an impulse signal is produced every rotation by 180° of the crank shaft) and outputs as a reference signal “x” is provided, and that reference signal “x” is supplied to the controller  25 . 
     The controller  25  executes so-called synchronous Filtered XLMS algorithm which is a sequentially renewal-type adaptive algorithm based on the residual vibration signal “e” and reference signal “x” so as to calculate the driving signal “y” to the vibration insulating device  20  and output that driving signal “y” to the vibration insulating device  20 . 
     Speaking concretely, the controller  25  has an adaptive digital filter W capable of varying a filter coefficient W i  (i=0, 1, 2, . . . , I−1: I is tap number) and, from the time when a current reference signal “x” is input, the controller  25  outputs the filter coefficient W i  of the adaptive digital filter W at a predetermined sampling clock interval as the driving signal “y”. On the other hand, the controller  25  executes a processing for renewing the filter coefficient W i  of the adaptive digital filter W based on the reference signal “x” and residual vibration signal “e”. 
     The renewal formula of the adaptive digital filter W is expressed in the form of an formula based on the Filtered-X LMS algorithm. 
     
       
           W   i ( n+ 1)= W   i ( n )−μ R   T   e ( n ) 
       
     
     Wherein, terms with (n), (n+1) respectively indicate values at the time of sampling time n, n+1, and μ is a convergence coefficient. Further, theoretically, the renewing reference signal R T  is a value obtained by filter processing with respect to the reference signal “x” with a transmission function filter C{circumflex over ( )} which is obtained by modeling a transmission function C between the electromagnetic actuator  52  and the load sensor  64  of the vibration insulating device  20  by use of a finite impulse response-type filter. Since the magnitude of the reference signal “x” is “1”, the value of the renewing reference signal R T  coincides with a sum of the impulse response waveforms at the sampling time n when the impulse response of the transmission function filter C{circumflex over ( )} is generated in sequential synchronously with the reference signal “x”. Although, theoretically, the reference signal “x” is filtered with the adaptive digital filter W so as to generate the driving signal “y”, since the magnitude of the reference signal “x” is “1”, even if the filter coefficient W i  is output in sequential as the driving signal “y”, the same result is obtained as when the result of the filtering processing is used as the driving signal “y”. 
     Next, an operation of the vibration insulating device of this embodiment will be described. 
     That is, in a condition in which the idling vibration or the indistinct sound vibration is generated from the engine  17 , the filter coefficient W i  of the adaptive digital filter W is supplied in sequential as the driving signal “y” to the electromagnetic actuator  52  of the vibration insulating device  20  from the controller  25 , at the predetermined sampling clock interval from the time when the reference signal “x” is input. 
     As a result, a magnetic force is generated in the excitation coil  52   c  corresponding to the driving signal “y”. Then, it can be considered that that magnetic force from the excitation coil  52   c  strengthens or weakens the magnetic force of the permanent magnet  52   c  because the magnetic path forming member  78 B has been already applied with a certain level of the magnetic force by the permanent magnet  52   c . That is, when no driving signal “y” is supplied to the excitation coil  52   b , the movable member  78  including the magnetic path forming member  78 B is displaced at a position in which a supporting force of the leaf spring  82  is balanced with the magnetic force of the permanent magnet  52   c . Then, when the driving signal “y” is supplied to the excitation coil  52   b  in this neutral state and the magnetic force generated in the excitation coil  52   b  by the driving signal “y” is opposite to the magnetic force of the permanent magnet  52   c , the movable member  78  is displaced in a direction in which the gap relative to the electromagnetic actuator  52  is increased. On the contrary, if the magnetic force generated in the excitation coil  52   b  is in the same direction as the magnetic force of the permanent magnet  52   c , the movable member  78  is displaced in a direction in which the gap relative to the electromagnetic actuator  52  is decreased. 
     As described above, the movable member  78  can be displaced in both ways. If the movable member  78  is displaced, the partition wall forming member  78 A forming a part of the partition wall of the fluid chamber  84  is also displaced, so that the volume of the fluid chamber  84  is changed. Due to the change of the volume, the so-called expansion spring of the elastic support  32  is changed. Thus, the active mounting force in both positive and negative directions is generated in the vibration insulating device  20 . 
     Each filter coefficient W i  of the adaptive digital filter which generates the driving signal “y” is renewed sequentially according to the aforementioned formula based on the synchronous Filtered-X LMS algorithm. Therefore, after a certain time has been passed and each filter coefficient W i  of the adaptive digital filter W is converged to an optimum value, by supplying the driving signal “y” to the vibration insulating device  20 , the idling vibration or the indistinct sound vibration which is transmitted from the engine  17  to the vehicle body  18  through the vibration insulating device  20  is reduced. 
     In this embodiment, the assembly part in which the movable member  78 , seal ring  72 , sealing elastic member  86 , leaf spring  82  and supporting ring  74  are integrated is used. After the gap holding ring  76  is disposed below this assembly part, it is set on the yoke  52   a  and then another gap holding ring  76  having a different height is selected appropriately until the gap H between the permanent magnet  52 C and the magnetic path forming member  78 B comes within a predetermined allowance. As a result, for example, a complex procedure in which connection or separation of the partition wall forming member and magnetic path forming member is repeated is eliminated, and thereby making it possible to reduce time and labor necessary for assembly of the vibration insulating device  20 . 
     Further, because the seal ring  72 , supporting ring  74 , and gap holding ring  76  are fit to the upper cylindrical body  70   a  of the spacer  70  coaxially with the mount axis P 1 , they can be installed without occurring a looseness or the like between the respective parts. Further, the gap holding ring  76  can be replaced easily and securely, so that the assembly performance of the vibration insulating device  20  can be improved. 
     Therefore, the gap H between the permanent magnet  52 C of the electromagnetic actuator  52  and the magnetic path forming member  78 B of the movable member  78  can be set at a high precision, it is possible to stabilize the volume change of the fluid chamber  84 , that is, vibration insulation performance thereof. 
     In this embodiment, the gap holding ring  76  corresponds to the gap holding member, the seal ring  72  corresponds to the first supporting member, and the supporting ring  74  corresponds to the second supporting member. The leaf spring  82  is supported by the first and second supporting members as a result, and the upper cylindrical body  70   a  of the spacer  70  corresponds to the spacer member. 
     Next, the vibration insulating device according to a second embodiment of the present invention and an assembly method therefof will be described with reference to FIG.  4 . 
     Because this embodiment has the basically same structure as that of the first embodiment, the same reference numerals are attached to the same components, and the description on the same structure and processing is omitted. 
     As shown in FIG. 4, a supporting ring  90  of this embodiment is a ring-like member having the same outside diameter as the seal ring  72  and gap holding ring  76 , and a convex-shaped ring  92  is formed on an inside circumference of the supporting ring  90 . A first curvature surface R 1  curved downward is formed to be continuous along its circumferential direction around an upper face of a proximal end of this convex-shaped ring  92 , and further a second curvature surface R 2  curved upward is formed also on a upper face continuous from the first curvature surface R 1  to an inner end such that the second curvature surface R 2  is continuous along its circumferential direction. 
     The leaf spring  82  supporting the movable member  78  resiliently supports the center portion of the bottom side of the partition wall forming member  78 A from a lower side of the partition wall forming member  78 A through a free end by the inner peripheral portion thereof. The outer peripheral portion of the leaf spring  82  is supported by the first and second curvature surfaces R 1  and R 2  of the aforementioned convex-shaped ring  92  from down side thereof through a free end. 
     Because the outer peripheral portion of the leaf spring  82  is so structured as to contact the first and second curvature surfaces R 1  and R 2  of the convex-shaped ring  92 , the contact surface pressure between the supporting ring  90  and the leaf spring  82  is reduced. Thus, the amount of wear of the supporting ring  90  and leaf spring  82  is also reduced, and further the fatigue of the leaf spring  82  always displaced in the vertical direction can be prevented. Therefore, if the supporting ring  90  of this embodiment is used, the durability of the leaf spring  82  can be largely improved. 
     Here, the convex-shaped ring  92  of this embodiment corresponds to the supporting portion. 
     The vibration insulating device and assembly method thereof according to the respective embodiments described above are not restricted to application thereof to a vehicle, and the present invention can be applied to other apparatus for reducing a vibration generated by other elements than the engine  17 . Regardless of the application object, the same operation and effect as the respective embodiments described above can be achieved. For example, the present invention can be applied to a vibration insulating device for reducing a vibration transmitted from a machine tool to a floor or a room. 
     Although in the respective embodiments above, the synchronous Filtered-X LMS algorithm is used as an algorithm for generating the driving signal “y”, the applicable algorithm is not restricted to this one, but for example, ordinary Filtered-X LMS algorithm or the like can be used instead. 
     The entire contents of a Patent Application No. TOKUGANHEI 10-38313, with a filling date of Feb. 20, 1998 in Japan, are hereby incorporated by reference. 
     Although the invention has been described above by reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art, in light of the teachings. The scope of the invention is defined with reference to the following claims.