JP2865519B2 - Fluid-filled vibration isolator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid filled type vibration damping device, and more particularly to a fluid filled type in which vibration control characteristics are switched by vibrating a part of a wall of a fluid chamber to control an internal pressure. The present invention relates to a vibration isolator.

[0002]

2. Description of the Related Art Conventionally, as a kind of a vibration isolator interposed between members constituting a vibration transmission system, a first support fitting attached to each of one of a vibration isolating connection or a supported member is provided. A structure in which the second support fitting is elastically connected by a rubber elastic body interposed between the two fittings is known, and is used, for example, as an engine mount for automobiles or a suspension bush. Have been

In recent years, as one means for realizing higher vibration isolation characteristics, Japanese Utility Model Application Laid-Open No. 3-73741 has been proposed.
In the official gazette etc., part of the wall is made of rubber elastic body,
A fluid chamber in which a predetermined incompressible fluid is enclosed is formed, and another part of the wall of the fluid chamber is formed of a diaphragm, and the diaphragm is vibrated to form a fluid chamber. There is proposed an apparatus in which the internal pressure is controlled to switch the vibration isolation characteristics.

In such a fluid-filled type vibration damping device, a ring-shaped permanent magnet is disposed behind the diaphragm, and a coil disposed on the inner peripheral surface of the permanent magnet is provided on the diaphragm. An electromagnetic force for exciting the diaphragm is generated by energizing the coil.

However, in the electromagnetic driving means having such a structure, since the efficiency of the electromagnetic force obtained with respect to the weight of the permanent magnet used and the amount of power supplied to the coil is low, the exciting force of the diaphragm is sufficiently reduced. There is a problem that it is extremely difficult to secure the fluid pressure and it is difficult to control the internal pressure of the fluid chamber, so that it is not possible to obtain practically satisfactory vibration damping characteristics.

In order to obtain a large excitation force, it is conceivable to increase the size of the permanent magnet, increase the number of windings of the coil, or increase the amount of current supplied to the coil. However, increasing the size of permanent magnets is not practical because many expensive and resource-saving magnet materials are required,
Increasing the number of windings of the coil also causes a problem that the total weight of the movable portion including the diaphragm increases, making it difficult to vibrate the diaphragm at a target frequency. Furthermore, when the amount of current to the coil is increased, the amount of heat generated by the coil increases, which may adversely affect the permanent magnet, the rubber elastic body, the sealed fluid, and the like. However, since the coil is attached to the diaphragm that is not exposed to the external space, the heat generated by the coil is difficult to be radiated to the outside, and there is a problem that the heat is trapped and the temperature easily rises.

[0007]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an electromagnetic force for exciting a diaphragm by a small permanent magnet. An object of the present invention is to provide a fluid-filled type vibration damping device that can be advantageously obtained.

Another object of the present invention is to provide a fluid-filled type vibration damping device in which an electromagnetic force for exciting the diaphragm can be advantageously obtained by a movable portion having a small total weight. .

It is a further object of the present invention to provide a fluid-filled type vibration damping device in which heat generated by energization of the coil can be advantageously radiated to the outside.

[0010]

In order to solve such a problem, a feature of the present invention is that a first support fitting and a second support fitting which are arranged at a predetermined distance from each other are connected to each other. Connected by rubber elastic body interposed between them,
In a fluid filled type vibration damping device in which a fluid chamber in which a predetermined incompressible fluid is sealed is formed by forming a part of a wall portion with such a rubber elastic body, the fluid chamber has another wall portion. Is constituted by a displaceable diaphragm, and an inner yoke member and an outer yoke member are arranged behind the diaphragm so that an outer peripheral surface of the inner yoke member and an inner peripheral surface of the outer yoke member An annular space is formed therebetween, and an inner coil is disposed on an outer peripheral surface of the inner yoke member, and an outer coil is disposed on an inner peripheral surface of the outer yoke member. The annular permanent magnet, which is a part, is disposed in the annular space so as to be displaceable in the axial direction between opposing surfaces of the inner coil and the outer coil, and the permanent magnet is connected to the diaphragm. is there.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an engine mount for an automobile according to an embodiment of the present invention. In the following description, the terms “upper” and “lower” refer to upper and lower in FIG.

In FIG. 1, reference numeral 10 denotes a first support bracket, and 12 denotes a second support bracket, which are opposed to each other at a predetermined distance from each other, and are provided with a rubber elastic body 14 interposed therebetween. Are connected elastically. In this engine mount, one of the first support fitting 10 and the second support fitting 12 is attached to the power unit side or the body side, so that the power unit is supported on the body with vibration isolation.

More specifically, the first support member 10 has an upper metal member 20 and a lower metal member 22 each having a substantially bottomed cylindrical shape having outer flange portions 16 and 18 provided on the periphery of the opening, and is overlapped in the axial direction. The outer flange portions 16 and 18 are connected by bolts. A mounting bolt 24 for mounting to the power unit side or the body side protrudes outward from the bottom wall of the upper bracket 20.

A space is formed inside the first support fitting 10 between the upper and lower fittings 20 and 22. And
A substantially thin disk-shaped flexible film 26 is accommodated and arranged in this space, and the outer peripheral edge is sandwiched between the upper and lower metal fittings 20 and 22. As a result, the space is fluid-tightly divided into the upper fitting 20 and the lower fitting 22 with the flexible film 26 interposed therebetween.

Further, a through hole 2 is formed in the peripheral wall portion of the upper fitting 20.
8 are formed, and the void formed inside communicates with the outside. On the other hand, a disc-shaped orifice fitting 30 is overlapped on the bottom wall of the lower fitting 22 and fixed by bolts, and an orifice passage 32 is formed between the overlapping surfaces of the fittings 22 and 30.

Further, the lower metal fitting 22 includes a rubber elastic body 14.
Are vulcanized and adhered. The rubber elastic body 14 has a substantially cylindrical shape with a taper, and the outer peripheral surface of the cylindrical wall portion of the lower fitting 22 is vulcanized and bonded to the opening end surface on the small diameter side. Thereby, the small-diameter side opening of the rubber elastic body 14 is closed by the first support fitting 10, and inside the rubber elastic body 14,
A recess 34 that opens downward is formed.

A restraining ring 36 for preventing buckling is vulcanized and bonded to the rubber elastic body 14 at an intermediate portion in the axial direction, and a ring-shaped connecting fitting 38 is formed on the large-diameter side opening end face. Are vulcanized and adhered.

Then, the second support fitting 12 having a thick, substantially annular plate shape is axially overlapped with the connecting fitting 38 and fixed by bolts. Note that the second support fitting 12 is provided with a bolt insertion hole 40 for attachment to the power unit side or the body side.

A disk-shaped diaphragm 44 having an outer diameter smaller than the inner diameter of the center hole 42 by a predetermined dimension is provided in the center hole 42 of the second support fitting 12. A substantially annular plate-shaped support rubber elastic body 46 is provided between radially opposed surfaces of the center hole 42 of the second support fitting 12 and the diaphragm 44.
Is interposed, and the diaphragm 44 is elastically supported by the second support fitting 12.

As described above, the vibration plate 44 is connected to the center hole 42 of the second support fitting 12 through the support rubber elastic body 46.
And the opening of the recess 34 is fluid-tightly closed, so that a part of the wall is formed of the rubber elastic body 14 and a predetermined incompressible fluid is sealed therein. A pressure receiving chamber 48 is formed. That is, in the pressure receiving chamber 48, when the rubber elastic body 14 is deformed at the time of vibration input, an internal pressure fluctuation is caused.

On the other hand, an incompressible fluid is also sealed in the space on the lower metal fitting 22 side formed in the first support metal fitting 10, so that a part of the wall portion is formed of the flexible film 26. Is formed. That is, the volume of the equilibrium chamber 52 is allowed to change based on the deformation of the flexible film 26. The first support 1
The space formed on the side of the upper bracket 20 formed in the
The air chamber 54 allows the deformation of the air chamber 54.

The pressure receiving chamber 48 and the equilibrium chamber 52 are connected to the orifice passage 3 formed in the first support fitting 10.
The two are communicated with each other. As a result, at the time of vibration input, fluid flows through the orifice passage 32 based on the internal pressure difference between the pressure receiving chamber 48 and the equilibrium chamber 52, and the vibration damping effect is exhibited based on the resonance action of the fluid. It is to be done. In this embodiment, the orifice passage 32 is provided so as to exhibit an effective damping effect on input vibration in a low frequency range such as a shake.
The length, cross-sectional area, etc. are tuned.

As the fluid to be filled in the pressure receiving chamber 48 and the equilibrium chamber 52, for example, water, alkylene glycol, polyalkylene glycol, silicone oil or the like is preferably used. Further, such fluid encapsulation can be advantageously performed, for example, by attaching the second support fitting 12 to the connection fitting 38 in the fluid.

Further, below the diaphragm 44, an inner yoke 56 and an outer yoke 58 are provided. Each of the inner yoke 56 and the outer yoke 58 is formed of a ferromagnetic material such as iron and has a thick cylindrical shape, and is connected and fixed to each other by an annular plate 60 on one axial side (lower side). As a result, they are arranged on the same axis at a predetermined radial distance from each other. In this embodiment, the annular plate 60 is formed of a non-magnetic material such as aluminum.

The outer yoke 58 is bolted to the second support fitting 12, so that the inner yoke 56 and the outer yoke 58 are disposed below the diaphragm 44. Thereby, the annular space 62 formed between the radially opposed surfaces of the inner yoke 56 and the outer yoke 58
Are opened in the central hole 42 of the second support fitting 12.

On the outer peripheral surface of the inner yoke 56, an inner coil 64 is fixedly disposed so as to be located over substantially the entire length in the axial direction, while on the inner peripheral surface of the outer yoke 58 The outer coil 66 is fixedly disposed so as to be located over substantially the entire length in the axial direction. The inner coil 64 and the outer coil 66 are radially opposed to each other with the annular space 62 interposed therebetween.

Further, in the annular space 62, a permanent magnet 6 having a cylindrical shape and having a magnetic pole portion at an inner peripheral portion and an outer peripheral portion is provided.
8 are accommodated. The permanent magnet 68 has an inner diameter slightly larger than the outer diameter of the inner coil 64 and the outer coil 6.
6 has an outer diameter slightly smaller than the inner diameter, and has an axial length shorter than the axial length of the inner and outer coils 64, 66. The coils 64 and 66 are located between the radially opposed surfaces, and are disposed so as to be axially displaceable in the annular space 62.

On the other hand, an inverted cup-shaped mounting member 70 is disposed in the center hole 42 of the second supporting member 12 in which the annular space 62 is opened. The mounting bracket 70 is superimposed on the diaphragm 44 at the center of the bottom thereof, and is fixed by the fixing bolt 72.
The peripheral wall is inserted into the annular space 62 and fixed to the permanent magnet 68. The mounting bracket 70 is formed of a non-magnetic material such as aluminum.

As a result, the permanent magnet 68 is
0, is connected to the diaphragm 44, and the diaphragm 4
4 is displaced together with the permanent magnet 68.

The head of the fixing bolt 72 for fixing the mounting member 70 to the diaphragm 44 is formed in a long rod shape and extends inside the inner yoke 56 to be positioned. The head end of the fixing bolt 72 is supported by a sliding bush 74 fixed to the opening of the inner yoke 56 so as to be slidable in the axial direction. Thus, the diaphragm 44 and the permanent magnet 68 are guided in the up-down direction, and the displacement in the left-right direction is regulated.

In the engine mount having such a structure, a magnetic field exists on the inner peripheral surface and the outer peripheral surface of the permanent magnet 68 where the magnetic pole portion is located. Moreover, both magnetic pole portions of the permanent magnet 68 are
6 and the outer yoke 58, the inner peripheral surface and the outer peripheral surface of the permanent magnet 68
In each case, a magnetic field having a high magnetic flux density exists.

Therefore, when power is supplied to the inner coil 64 and the outer coil 66 disposed on the inner and outer peripheral sides of the permanent magnet 68 in which such a magnetic field exists, the permanent magnet 68 and the inner and outer coils 64, An electromagnetic force is generated between the permanent magnet 68 and an axial thrust on the permanent magnet 68. In other words, based on the magnetic field energy generated by energizing the inner and outer coils 64 and 66 and the magnetic moment in the permanent magnet 68, the permanent magnet An axial thrust is exerted on 68. The inner coil 64 and the outer coil 6
6 is supplied with a current in the same circumferential direction in order to exert an axial thrust on the permanent magnet.

The axial thrust exerted on the permanent magnet 68 is transmitted to the diaphragm 44 and acts as a driving force for the diaphragm 44. In addition, by supplying an alternating current to the inner coil 64 and the outer coil 66, a thrust that changes in the vertical direction is exerted on the permanent magnet 68 and, in turn, the diaphragm 44, and the diaphragm 44 reciprocates vertically (vibrates). You will be swayed. The amplitude and the vibration frequency of the diaphragm 44 are controlled by the inner coil 64 and the outer coil 66.
Can be controlled by adjusting the magnitude and frequency of the current that feeds the power supply.

Therefore, in the engine mount having the above-described structure, the inner coil 64 and the outer coil 66 are disposed so as to be opposed to the magnetic pole portions on both sides of the permanent magnet 68, respectively. Since the diaphragm 44 is vibrated by an electromagnetic force generated between the permanent magnet 66 and the permanent magnet 68, the coil is arranged to face only the inner peripheral surface side of the permanent magnet as described in the above-mentioned publication. Electromagnetic force can be obtained more efficiently than the conventional structure.

Further, since the inner coil 64 and the outer coil 66 are both disposed between the magnetic pole portions of the permanent magnet 68 and the opposing surfaces of the inner yoke 56 and the outer yoke 58, the leakage of the permanent magnet 68 is prevented. The magnetic flux is suppressed, and a large magnetic flux density can be obtained in the space where the inner and outer coils 64 and 66 are disposed. Therefore, the electromagnetic force generated between the permanent magnet 68 and the inner and outer coils 64 and 66 can be obtained. That is, the exciting force exerted on the diaphragm 44 can be more advantageously obtained.

The inner yoke 56 to which the inner coil 64 is attached and the outer yoke 58 to which the outer coil 66 is attached are both exposed to the external space directly or indirectly via the bush 74. Therefore, heat generated when the current is supplied to the inner and outer coils 64 and 66 is easily radiated, an excellent cooling effect can be exhibited, and various heat damages can be effectively prevented.

Further, since the cooling effect of the inner and outer coils 64 and 66 is high, a large electric current can be passed through the inner and outer coils 64 and 66, whereby the electromagnetic force generated between the inner and outer coils 64 and 66 and the permanent magnet 68, that is, Exciting force exerted on diaphragm 44 can be obtained even more advantageously.

In the engine mount, as described above, the magnetic flux density in the space in which the inner and outer coils 64 and 66 are disposed is advantageously ensured, and the inner and outer coils 64 and 6 are secured.
By increasing the supply current to the permanent magnet 6,
Since the electromagnetic force generated between the coil 8 and the inner and outer coils 64 and 66 can be efficiently obtained, the diaphragm 4
4 while sufficiently securing the exciting force exerted on the permanent magnet 6.
8 can be reduced in size.

Further, by reducing the size of the permanent magnet 68, the weight of the movable portion including the diaphragm 44 can be reduced, thereby reducing the electromagnetic force required for driving the diaphragm 44. At the same time, the resonance frequency of the diaphragm 44 increases, and it becomes easy to obtain an effective vibration damping effect even for input vibration in a higher frequency range.

In the present embodiment, the fixing bolt 72
Is guided in the axial direction by the bush 74, so that the displacement of the permanent magnet 68 in the direction perpendicular to the axis is prevented, so that the contact of the permanent magnet 68 with the coils 64 and 66 is prevented as much as possible. In addition, there is an advantage that excellent durability and reliability are exhibited.

Next, FIG. 2 shows a cylindrical engine mount as another embodiment of the present invention. Note that the present embodiment shows a mounting structure when the exciting force generating portion of the diaphragm shown in the first embodiment is applied to a cylindrical engine mount substantially as it is, In the following, the structure of the mount body will be schematically described, and members and portions having the same structure as in the first embodiment will be described in detail by assigning the same reference numerals to those in the first embodiment. Detailed description is omitted.

The cylindrical engine mount of this embodiment is provided with a cylindrical inner tube fitting 76 extending in a substantially central portion thereof in the axial direction as a first support fitting. A metal sleeve 78 is disposed radially outward of the inner cylindrical fitting 76 at a predetermined distance in the radial direction and substantially coaxially.
And, these inner tube fittings 76 and metal sleeve 78
They are elastically connected by a rubber elastic body 80 interposed between them.

A first window portion 82 and a second window portion 84 are formed at a central portion in the axial direction of the metal sleeve 78 at positions opposed to each other in a direction perpendicular to the axis. Further, a first pocket portion 86 opening through the first window portion 82 and a second window portion 8 are provided at a central portion in the axial direction of the rubber elastic body 80.
A second pocket 88 opening through 4 is formed.

Further, the rubber elastic body 80 has axially penetrated through the bottom wall portion, which is located on both sides of the inner metal fitting 76 and separates the first pocket portion 86 and the second pocket portion 88. Empty spaces 90, 90 are provided.
Then, the bottom wall portion of the second pocket portion 88 is thinned by these cavities 90, 90, and the flexible film 9 is easily deformed.
It is 2. Further, an orifice passage 94 that connects the first pocket portion 86 and the second pocket portion 88 to each other is formed radially outside the one space 90.

At the center in the axial direction of the inner cylindrical member 76, a stopper member 96 having a substantially rectangular block shape as a whole is fixed, and is protruded outward from the center of the bottom wall of both pocket portions 86 and 88. Have been. Further, a flat umbrella fitting 98 is fixed by caulking to the protruding end surface of the stopper fitting 96 on the first pocket portion 86 side, and an annular constriction is formed between the stopper fitting 96 and the inner peripheral surface of the first pocket portion 86. A part 100 is formed. In addition, on the outer surface of the umbrella fitting 98 and on the protruding end face of the stopper fitting 96 on the second pocket portion 88 side,
Buffer rubbers 102 and 104 are provided, respectively.

Further, a large-diameter cylindrical outer tube fitting 106 is externally inserted into the metal sleeve 78 and fixedly fitted thereto. Further, the outer cylindrical fitting 106 is press-fitted into a circular mounting hole 110 of a mounting bracket 108 as a second support fitting and assembled.

As a result, the openings of the first pocket 86 and the second pocket 88 are covered, and a pressure receiving chamber 112 and a balancing chamber 114 in which a predetermined incompressible fluid is sealed are formed. . In addition, these pressure receiving chambers 112
And the balance chamber 114 are communicated with each other through the orifice passage 94.

The outer tube fitting 106 includes a pressure receiving chamber 112.
A large-diameter communication hole 116 is provided at the top of the mounting bracket 108.
A large-diameter through-hole 118 is provided at a position corresponding to the 16 openings. Further, a diaphragm 120 having a disk shape having a predetermined dimension smaller than that of the through hole 118 is provided at an outer opening of the through hole 118. 108 through holes 118
Are elastically supported with respect to the opening.

As a result, the through hole 118 of the mounting bracket 108 has its outer opening covered in a fluid-tight manner, while its inner opening communicates with the pressure receiving chamber 112 through the communicating hole 116 of the outer cylinder fitting 106. The pressure receiving chamber 112 includes the inside of the through hole 118. In addition,
A seal rubber 124 is interposed at a connection between the through hole 118 and the communication hole 116.

Behind the diaphragm 120 disposed at the opening of the through hole 118, electromagnetic driving means including a permanent magnet 68 and inner and outer coils 64 and 66 is provided as in the first embodiment. The permanent magnet 68 is mounted on the diaphragm 120 via the mounting bracket 70 while the outer yoke 58 is provided and bolted to the mounting bracket 108.

That is, the cylindrical engine mount having such a structure is constituted by the inner cylinder fitting 76 and the mounting bracket 10.
8 is mounted on each of the power unit side and the body side, so that it is interposed between the power unit and the body.

At the time of vibration input, the orifice passage 94
Alternatively, an anti-vibration effect can be exhibited based on the resonance action of the fluid caused to flow through the constriction 100.
Further, the vibration plate 44 is vibrated by the electromagnetic driving means, and
By controlling the internal pressure of 12, an anti-vibration effect can be exhibited.

In this embodiment, the electromagnetic driving means having the same structure as that of the first embodiment is employed, so that the electromagnetic force for exciting the diaphragm 44 can be efficiently obtained. Thus, the same effects as those of the first embodiment can be effectively exhibited.

Although the embodiments of the present invention have been described above in detail, these are literal examples, and the present invention is not construed as being limited to such specific examples.

For example, in each of the above-described embodiments, a variable-capacity equilibrium chamber connected to the pressure receiving chamber through the orifice passage is provided, but a vibration isolator having no orifice passage or equilibrium chamber is provided. However, the present invention can be advantageously applied.

Further, as a current supplied to the inner and outer coils 64 and 66, a pulsating current in addition to the alternating current can be used. In this case, the elastic force of the supporting rubber elastic bodies 46 and 122 can be used as the vibrating force in one displacement direction of the diaphragm.

Further, in each of the above-described embodiments, a specific example in which the present invention is applied to an engine mount for a vehicle is shown. However, the present invention is also advantageous for various vibration damping devices other than the engine mount. It can be applied to

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements and the like can be implemented in an embodiment,
It goes without saying that all such embodiments are included in the scope of the present invention without departing from the spirit of the present invention.

[0060]

As is clear from the above description, in the fluid-filled type vibration damping device having the structure according to the present invention, the inner coil and the outer coil are respectively located at the opposing positions close to the two magnetic pole portions of the permanent magnet. Due to this, the electromagnetic force for driving the diaphragm can be efficiently obtained by the small permanent magnet.

Further, in such a fluid-filled type vibration damping device, the permanent magnet which can be reduced in size and weight is made movable, and the permanent magnet is connected to the diaphragm, so that the weight of the movable portion including the diaphragm can be reduced. Therefore, it is possible to advantageously obtain an anti-vibration effect against input vibration in a high frequency range.

Further, in such a fluid-filled type vibration damping device, the heat generated in the inner coil and the outer coil can be advantageously radiated to the outside through the inner yoke and the outer yoke. A large current can be passed through the inner and outer coils, so that a large permanent magnet can be obtained more efficiently with a small permanent magnet.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an engine mount as one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a cylindrical engine mount as another embodiment of the present invention.

[Brief description of reference numerals]

 Reference Signs List 10 first support fitting 12 second support fitting 14 rubber elastic body 32 orifice passage 44 diaphragm 46 supporting rubber elastic body 48 pressure receiving chamber 52 equilibrium chamber 56 inner yoke 58 outer yoke 62 annular space 64 inner coil 66 outer coil 68 Permanent magnet 70 Mounting bracket 76 Inner barrel fitting 80 Rubber elastic body 94 Orifice passage 106 Outer barrel fitting 108 Mounting bracket 112 Pressure receiving chamber 114 Equilibrium chamber 120 Vibration plate 122 Support rubber elastic body

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-4-312229 (JP, A) JP-A-4-135000 (JP, A) JP-A-5-340441 (JP, A) JP-A-6-360 117478 (JP, A) JP-A-6-174003 (JP, A) JP-A-53-79528 (JP, U) JP-A 2-110464 (JP-A-3-73741) (UP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16F 13/00

Claims (2)

(57) [Claims] 1. A first support fitting and a second support fitting which are arranged at a predetermined distance from each other are connected by a rubber elastic body interposed therebetween, and a predetermined non-conductive member is internally provided. In a fluid-filled type vibration damping device in which a fluid chamber filled with a compressible fluid is formed by forming a part of a wall with such a rubber elastic body, another part of a wall of the fluid chamber is displaced. It is constituted by a possible diaphragm, the inner yoke member and the outer yoke member are arranged behind the diaphragm, and an annular space is formed between the outer peripheral surface of the inner yoke member and the inner peripheral surface of the outer yoke member. and forming, the inner coil on the outer circumferential surface of the inner yoke member, the outer coil to the inner peripheral surface of the outer yoke member, a short while disposed respectively, than the axial length of their inner and outer coil axis
An annular permanent magnet having a length in the direction and having a magnetic pole portion at an inner peripheral portion and an outer peripheral portion is disposed so as to be axially displaceable between opposing surfaces of the inner coil and the outer coil in the annular space. And then attach the inverted cup-shaped mounting bracket to the bottom center.
At the same time, fix it with the fixing bolt
And inserting the peripheral wall of the mounting bracket into the annular space.
Fixed to the permanent magnet through the mounting bracket.
To connect the permanent magnet to the diaphragm,
The fixing bolt for fixing a tool to the diaphragm is attached to the diaphragm.
From inside into the inside of the inner yoke member, and
Slide the tip end of the bolt to the inner yoke member
A fluid filled type vibration damping device characterized by being supported by a bush so as to be slidable in the axial direction . 2. A part of a wall portion is made of the rubber elastic body.
The specified incompressible fluid is enclosed inside the
Due to deformation of the rubber elastic body at the time of input, internal pressure fluctuations occur
While the fluid chamber is constituted by the pressure receiving chamber to be impregnated,
A part of the wall is made of a flexible film and a predetermined non-pressure
A compressible fluid is sealed, and based on the deformation of the flexible membrane,
To form an equilibrium chamber where volume changes are
An orifice passage communicating the pressure chamber and the equilibrium chamber is provided.
The fluid filled type vibration damping device according to claim 1.