JP2001003977A - Vibration isolating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the durability of a vibration isolating apparatus by preventing an elastic film from making contact with the circumference of a through hole. SOLUTION: An intermediate cylinder 22 and an intermediate block 24 are arranged inside an outer cylinder metal fitting 16 an a space partitioned by the intermediate block 24 and an elastic body 28 constitutes a main liquid chamber 30. A shake orifice 64 and an idle orifice 60 communicate the main liquid chamber 30 with a first auxiliary liquid chamber 32. An orifice 62 for confining communicates the main liquid chamber 30 with a second auxiliary liquid chamber 96 and a rotor 36 opens and closes the idle orifice 60 and the orifice 62 for confining. In this case, a second diaphragm 94 constituting a portion of the partition wall of the second auxiliary liquid chamber 96 is provided with a thick-walled part 94B, and a through hole 80 provided in the outer cylinder metal fitting 16 is arranged in an opposite relation to the thick-walled part 94B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolator for preventing transmission of vibration from a member that generates vibration, and is applicable to, for example, a case where transmission of vibration from an engine mounted on a vehicle is prevented. Things.

[0002]

2. Description of the Related Art For example, an anti-vibration device as an engine mount is disposed between an engine of a vehicle serving as a vibration generating portion and a vehicle body serving as a vibration receiving portion. There is known a structure that absorbs vibration and prevents vibration from being transmitted to the vehicle body. That is, as an example of the vibration isolator, not only the inner cylinder is arranged inside the outer cylinder formed in a cylindrical shape, but also the main liquid chamber and the sub liquid chamber are provided inside the outer cylinder, and the orifice is used. There is a bush type of structure in which these liquid chambers communicate with each other through a restriction passage. When the mounted engine operates and generates vibration, the vibration is absorbed or attenuated as a low dynamic spring due to the liquid column resonance of the liquid in the restricted passage connecting these liquid chambers. Thus, the transmission of vibration is prevented.

FIGS. 11 and 1 show an example of this vibration isolator.
The conventional vibration damping device will be described below in detail with reference to FIGS. That is, the main liquid chamber 118 and the first sub liquid chamber 120 communicating with the main liquid chamber 118 through the orifice 122 are provided inside the outer cylinder 112 serving as the outer frame of the vibration isolator. Liquid chamber 118
Second sub-liquid chamber 1 communicated with the orifice 132
The diaphragm 134 which is a rubber membrane constitutes a part of the partition wall of the second sub liquid chamber 130.

[0004] The air chamber 138 adjacent to the second sub-liquid chamber 130 via the diaphragm 134 is generally closed in many cases.
A through hole 136, which is an air hole for allowing air to enter and exit to facilitate deformation of the diaphragm 134, is provided in the outer cylinder 11
2 also has a structure provided.

[0005]

However, when the amount of deformation of the elastic body 116 accompanying the stroke of the inner cylinder 114 in the Y direction increases and the amount of liquid flowing into the second auxiliary liquid chamber 130 increases, As shown by a two-dot chain line, the diaphragm 134 comes into contact with the inner peripheral surface of the outer cylinder 112 where the through hole 136 exists. The through-hole 136 is generally provided in the outer cylinder 112 by press working. In this press working, the through-hole 13 located on the inner peripheral surface of the outer cylinder 112 is formed.
The burrs will occur at the edge of No. 6. Therefore, when the diaphragm 134 comes into contact with the portion where the through hole 136 exists, the life of the diaphragm 134 is shortened by the burrs, and accordingly, the durability of the vibration isolator may be reduced.

[0006] In order to solve this drawback, the diaphragm 1
It is conceivable to provide a stopper projection on the surface of the outer cylinder 112, but as the stopper projection frequently contacts the inner peripheral surface of the outer cylinder 112, the manner in which the stopper projection contacts the outer cylinder 112 is not stable. Therefore, there is a disadvantage that tuning of the vibration isolation characteristics is difficult, and the dispersion of the vibration isolation characteristics becomes large.

The present invention has been made in consideration of the above circumstances, and has as its object to provide a vibration damping device capable of preventing the elastic film from contacting the periphery of the through hole and improving durability.

[0008]

According to a first aspect of the present invention, there is provided a vibration isolator which is connected to one of a vibration generator and a vibration receiver, and connected to the other of the vibration generator and the vibration receiver. A second mounting member provided with a through-hole, an elastic body disposed between the mounting members and elastically deformable, a liquid filled with the elastic body as a part of the partition wall, and the internal volume is increased by deformation of the elastic body. A main liquid chamber that changes, a sub liquid chamber that communicates with the main liquid chamber via a passage and is filled with a liquid, and has a high-rigidity portion in part, and a through-hole faces the high-rigidity portion. An elastic film which is arranged in a positional relationship and at least partially forms a partition of the sub liquid chamber so as to be elastically deformable.

The operation of the vibration isolator according to claim 1 will be described below. When vibration is transmitted from the vibration generating unit connected to either the first mounting member or the second mounting member, the elastic body is deformed and the vibration is attenuated by the elastic body. Further, as the internal volume of the main liquid chamber changes due to the deformation of the elastic body, the liquid actively flows toward the sub liquid chamber through the passage. As a result, a pressure change occurs in the liquid in the passage, and accordingly, an elastic film that elastically deforms at least a part of the partition wall of the sub liquid chamber is deformed. That is, when the vibration is transmitted from the vibration generating unit side, not only the deformation of the elastic body but also the dynamic spring constant is reduced by the passage connecting the main liquid chamber and the sub liquid chamber, and the vibration is absorbed. Vibration is less likely to be transmitted to the vibration receiving portion connected to either the second mounting member or the first mounting member.

[0010] Further, a through-hole provided in the second mounting member is arranged in a positional relationship facing a high rigidity portion provided in a part of the elastic film which can be elastically deformed. Therefore, by providing the through-hole opposite to the high-rigidity portion of the elastic film that is hard to move with high rigidity, the elastic film hardly comes into contact with the periphery of the portion where the through-hole exists in the second mounting member, The reliability of the elastic film is improved. And as a result of improving the reliability of an elastic film, the durability of a vibration isolator improves.

The operation of the vibration isolator according to claim 2 will be described below. The present invention operates in the same manner as the first embodiment. Further, a thick portion having a large thickness is provided in a part of the elastic film, and by forming a high rigidity portion with the thick portion, the reliability of the elastic film is improved as in claim 1, The durability of the vibration isolator is improved. In other words, in the present invention, the durability of the vibration isolator can be improved at low cost because it has a simple configuration in which the thickness of the elastic film is only partially changed.

The operation of the vibration isolator according to claim 3 will be described below. In the present invention, the same operation as in the first and second aspects is performed, but three of the four sides around the thick portion are restrained as seal portions for preventing leakage of liquid from the sub liquid chamber. Because the rigidity of the thick portion is further increased, it becomes more difficult to move, and the elastic film becomes more difficult to contact the periphery of the portion where the through hole facing the thick portion exists. Sexuality will be further enhanced.

The operation of the vibration isolator according to claim 4 will be described below. The present invention operates in the same manner as the first and second aspects, except that the width of the thick portion is made smaller than the width of the deformable elastic film portion other than the thick portion. As in the case of the third aspect, the rigidity of the thick portion is further increased to make it more difficult to move, and the elastic film becomes more difficult to come into contact with the periphery of the portion where the through hole facing the thick portion exists.
The reliability of the elastic film is further improved.

According to a fifth aspect of the present invention, there is provided an anti-vibration device having an inner cylinder connected to one of a vibration generating section and a vibration receiving section, and a cylindrical section connected to the other of the vibration generating section and the vibration receiving section and surrounding the inner cylinder. An outer cylinder formed with a through hole and an elastic body that is disposed between the inner cylinder and the outer cylinder and that can be elastically deformed,
A main liquid chamber in which a liquid is sealed with the elastic body as a part of the partition wall and the inner volume is changed by deformation of the elastic body, and a sub liquid chamber in which the liquid is sealed while communicating with the main liquid chamber through a passage, An elastic film that has a high-rigidity part in a part and is disposed in a positional relationship in which the through-hole faces the high-rigidity part, and forms at least a part of the partition wall of the sub-liquid chamber so as to be elastically deformable,
It is characterized by having.

The operation of the vibration isolator according to claim 5 will be described below. The present invention has the same effect as the first embodiment. However, in the present invention, the first mounting member is replaced with an inner cylinder, and the second mounting member is replaced with a cylindrical outer cylinder, and the outer cylinder is provided with a through-hole. Therefore, when vibration is transmitted from the vibration generating section to either the inner cylinder or the outer cylinder, it is difficult to transmit the vibration to the vibration receiving section to which either the outer cylinder or the inner cylinder is connected.

Further, a through hole provided in the outer cylinder is arranged in a positional relationship facing a high rigidity portion provided in a part of the elastic film which can be elastically deformed. Therefore, by providing the through-hole opposite to the high-rigidity portion of the elastic film which is hard and hard to move, it becomes difficult for the elastic film to come into contact with the periphery of the outer cylinder where the through-hole exists, and The reliability will increase.
And as a result of improving the reliability of an elastic film, the durability of a vibration isolator improves.

The operation of the vibration isolator according to the sixth to eighth aspects will be described below. Claim 6 operates in the same manner as Claim 2, Claim 7 operates in the same manner as Claim 3, and Claim 8 operates in the same manner as Claim 4. Therefore, Claims 6 to 8 also apply. Thus, the reliability of the elastic film is improved, and the durability of the vibration isolator is improved.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a vibration isolator according to the present invention is shown in FIGS. 1 to 10, and the present embodiment will be described with reference to these drawings. As shown in FIGS. 1 to 4, the so-called bush type vibration damping device 10 is provided with a bracket 12 having a ring-shaped lower portion and a leg portion 12 </ b> A for connection to a vehicle body (not shown). A cylindrical outer tube fitting 16 is fitted and disposed in the inside 12.

As shown in FIG. 8, a pair of arc members 14A each formed in an arc shape and a pair of connecting members 14B for connecting between both ends of the pair of arc members are provided.
A metal supporting frame 14 is formed in a square frame shape, and an outer peripheral edge 20A constituting an outer peripheral portion of the first diaphragm 20, which is a thin film member made of rubber, is vulcanized on the rectangular frame-shaped supporting frame 14. Glued. The first diaphragm 20 is located closer to the upper side in FIGS. 1 and 2 on the inner peripheral surface side of the outer cylinder fitting 16 by installing the support frame 14 at a position closer to the upper side in the outer cylinder fitting 16. Be placed.

On the other hand, an intermediate cylinder 22 and an intermediate block 24 are inserted into the outer cylinder fitting 16.
And the intermediate block 24 constitutes a partition member. The intermediate block 24 is formed in a substantially semicircular block shape when viewed from the axial direction of the outer cylindrical member 16. As shown in FIG. 1, the outer peripheral surface of the intermediate block 24 is formed on the inner peripheral surface of the outer cylindrical member 16. Closely adhered. As shown in FIG. 2, flange portions 22 </ b> A are formed at both ends in the axial direction of the intermediate cylinder 22. An intermediate block 24 is provided between the pair of flange portions 22 </ b> A and closer to the lower side of the intermediate cylinder 22. It will be inserted. The outer peripheral surfaces of the pair of flange portions 22 </ b> A are in close contact with the inner peripheral surface of the outer cylinder fitting 16. Along with this, the support frame 14 is fitted between the pair of flange portions 22 </ b> A and closer to the upper side of the intermediate cylinder 22, so that the first
The outer peripheral edge 20 </ b> A of the diaphragm 20 is fixed while being supported between the inner peripheral surface side near the upper part of the outer cylinder fitting 16 and the intermediate cylinder 22.

As shown in FIG. 1 and FIG. 2, the space between the first diaphragm 20 and the outer cylinder 16 is the first space.
The first diaphragm 2 shown in FIG. 1 is an air chamber 31 which is a central portion in the axial direction of the outer tube fitting 16 shown in FIG.
A through hole 18 is provided in a portion of the outer cylinder 16 eccentric along the circumferential direction of the outer cylinder 16 from a position facing the center of the outer cylinder 0. That is, the through-hole 18 provided in the outer tube fitting 16 is arranged to face the vicinity of the outer peripheral edge 20 </ b> A of the first diaphragm 20, and the hole 12 </ b> B is located at the position of the bracket 12 overlapping the through-hole 18. Are provided through. For this reason, the first air chamber 31 is
6 through the through-hole 18 and the hole 12B of the bracket 12, and the air in the first air chamber 31 can flow to and from the outside through the through-hole 18 and the hole 12B.

As shown in FIGS. 1 and 2, a portion of the intermediate cylinder 22 facing the flat portion 24B serving as the upper surface of the intermediate block 24 is cut out and has a hollow interior.
An inner cylinder fitting 26 connected to an engine (not shown) penetrates the inside of the cavity. This inner cylinder fitting 26 is used for the outer cylinder fitting 16.
And an elastic body 28 formed of a rubber material or the like is stretched between the intermediate tube 22 and the intermediate tube 22. As a result, the inner cylindrical member 26 can be moved relative to the outer cylindrical member 16. That is, the inner cylindrical metal fitting 26 connected to the engine as the vibration generating part is the first mounting member, and the outer cylindrical metal fitting 1 connected to the vehicle body as the vibration receiving part via the bracket 12.
6 is a second mounting member.

The elastic body 28 also extends on the outer peripheral surface between the flange portions 22A of the intermediate cylinder 22, and protrudes from both ends of the intermediate block 24 on the inner peripheral side of the arc-shaped portion. A part of the elastic body 28 is in close contact with the inner circumferential arc surface 24A. A notch 28A is formed in the middle of the elastic body 28 and below the inner cylindrical fitting 26 so as to depress the lower surface of the elastic body 28. The space between them is the main liquid chamber 30.

On the other hand, a pair of flange portions 22 of the intermediate cylinder 22
Between A, a first sub liquid chamber 32 surrounded by the intermediate cylinder 22 and the first diaphragm 20 is formed. Also,
As shown in FIG. 10, on the outer peripheral surface of the intermediate block 24,
A groove 46 is formed in a U-shape. One end of the groove 46 opens to the right end of the intermediate block 24 in FIG. 1 and is connected to the first auxiliary liquid chamber 32. This groove 4
The other end of 6 communicates with the main liquid chamber 30 via a through hole 48 formed through the inside of the intermediate block 24. The groove 46 and the through hole 48 form a shake orifice 64 as a restriction passage for absorbing shake vibration.

Further, the plane portion 24B of the intermediate block 24
A circular hole 34 is formed on the side of the intermediate block 2.
A circular through-hole 35 penetrating the outer peripheral surface of 4 is formed coaxially with the circular hole 34. The counterbore portion 3 is coaxially formed with the circular through hole 35 on the outer cylinder fitting 16 side of the intermediate block 24.
9 is provided, and an O-ring 41 for sealing is fitted outside the counterbore portion 39.

The circular hole 34 and the circular through hole 35 have:
A rotor 36 as a valve is rotatably inserted.
The main liquid chamber 30 side of the rotor 36 has a cylindrical cylindrical portion 36A.
A thin shaft portion 36B as a rotation axis is provided coaxially with the cylindrical portion 36A at a portion opposite to the cylindrical portion 36A. Further, a lid plate 40 also serving as a washer is fixed to the plane portion 24B side of the intermediate block 24 to prevent the rotor 36 from coming off.

A pair of O-rings 44 are fitted around the outer periphery of the thin shaft portion 36B. Therefore, this O
The liquid does not leak out of the intermediate block 24 through the circular through hole 35 by the ring 44. Further, a through hole 38 is formed in the cylindrical portion 36A of the rotor 36 to communicate the inside and the outside of the cylindrical portion 36A. On the other hand, one end side of the intermediate block 24 is connected to the circular hole 34 and FIG.
The passage 56 extends in a direction perpendicular to the plane of FIG.
Are formed. That is, one end of the passage 56 is opened at the inner periphery of the circular hole 34.

As shown in FIG. 9 and FIG.
The other end of 6 is communicated with one end of a passage 58 which is a groove formed in the outer periphery of the intermediate block 24 along the circumferential direction.
The other end of the passage 58 communicates with the first sub liquid chamber 32. Accordingly, when the rotor 36 rotates and the through hole 38 faces the passage 56 as shown in FIG. 1, the main liquid chamber 30 and the first sub liquid chamber 32 are communicated by the passages 56 and 58. Will be. In other words, the idle orifice 6 which communicates the main liquid chamber 30 and the first sub liquid chamber 32 by these passages 56 and 58 and serves as a restriction passage for absorbing idle vibration.
0 will be configured.

On the other hand, as shown in FIGS. 1 and 3, the intermediate block 24 is further provided with a recessed hole 92 extending in the radial direction of the circular hole 34 and in the opposite direction to the passage 56.
Although much shorter than 6, it is formed. A second sub-liquid chamber 96 which is an arc-shaped space is formed in a portion of the intermediate block 24 corresponding to the opening end of the hole 92, and the end of the hole 92 is formed in a second shape. The second sub liquid chamber 96 is open. Accordingly, the rotor 36 rotates, and FIG.
When the through hole 38 is opposed to the hole 92 for stagnation as shown in FIG. 7, the communication between the main liquid chamber 30 and the second sub liquid chamber 96 is established. In other words, the hollow hole 92 formed much shorter than the passage 56 so as to absorb the high frequency vibration.
The main orifice orifice 62 communicates with the main liquid chamber 30 and the second sub liquid chamber 96 and serves as a restriction passage for absorbing a medium-to-low speed muffled sound that is higher in frequency than idle vibration.
Is configured.

On the outer peripheral side of the intermediate block 24 with respect to the second sub liquid chamber 96, a second elastic film made of rubber is formed.
The diaphragm 94 is arranged with its outer peripheral portion sandwiched between the outer tube fitting 16 and the intermediate block 24. That is, a seal portion 94A for preventing leakage of the liquid from the second sub liquid chamber 96 to the outside is formed over the entire outer peripheral portion of the second diaphragm 94, and the seal portion 94A is formed on the outer cylindrical metal fitting 16A. And the intermediate block 24. Therefore, the inside of the seal portion 94A of the second diaphragm 94 is thinned, and a part of the partition wall of the second sub liquid chamber 96 is elastically deformable.

As shown in FIGS. 1, 6 and 7, not only is the thin portion 94C provided inside the seal portion 94A of the second diaphragm 94, but it is slightly thinner than the thin portion 94C. A thick portion 94B to be thick is provided on a part of the inside of the seal portion 94A of the second diaphragm 94, and the thick portion 94B forms a highly rigid portion of the second diaphragm 94. Here, the thickness of the thin portion 94C is, for example, 1.5 mm, whereas the thickness of the thick portion 94B is, for example, 2 mm.

On the other hand, as shown in FIGS. 6 and 7, three of the four sides around the thick portion 94B are sealed with the seal portion 94A.
And three sides around the thick portion 94B are constrained by the seal portion 94A, and the width D1 of the thick portion 94B is formed smaller than the width D2 of the thin portion 94C. Is also reduced, so that the thick portion 94B has higher rigidity.

As shown in FIGS. 1 and 3, the space between the second diaphragm 94 and the inner peripheral surface of the outer cylinder 16 is built into the outer cylinder 16 so that gas enters the interior. A second air chamber 98 is formed, and a through-hole 80 is provided and disposed so as to penetrate the outer cylinder fitting 16 in a positional relationship facing the thick portion 94B via the second air chamber 98. further,
At the position of the bracket 12 overlapping the through hole 80, the hole 1
2C is provided through. For this reason, the second air chamber 9
8 communicates with the outside through the through-hole 80 of the outer tube fitting 16 and the hole 12C of the bracket 12, and the air in the second air chamber 98 can come and go through the through-hole 80 and the hole 12C. The second sub liquid chamber 96
The thin portion 94C of the second diaphragm 94, which forms a part of the partition wall, is more easily deformed. A stopper projection 94D for preventing excessive deformation of the second diaphragm 94 is formed at a portion of the thin portion 94C near the thick portion 94B so as to project toward the second air chamber 98. .

As shown in FIGS. 1, 3 and 5,
In addition to the through holes 18 and 80, the outer tube 16 has a rivet hole 82 for a rivet 78 for sealing the inside of the vibration isolator 10 and a hole for receiving a rotating shaft 71 of a motor 70 described later. The parts 84 are respectively provided penetrating.

Further, as shown in FIG. 1, the area of the second diaphragm 94 is smaller than the area of the first diaphragm 20 constituting a part of the partition wall of the first sub liquid chamber 32, and the area of the second diaphragm 94 is small. Since the thickness is substantially equal to that of the first diaphragm 20, the second diaphragm 94 has higher rigidity than the first diaphragm 20. The main liquid chamber 30, the first sub liquid chamber 32, and the second sub liquid chamber 96 are sealed so as to be filled with a liquid such as ethylene glycol.

On the other hand, a motor 70 as an actuator is disposed outside the bracket 12. The tip of the rotating shaft 71 of the motor 70 is
6B. The motor 70 is provided with a flange 70A.
0A is formed in an arc shape along the outer diameter of the bracket 12. Therefore, a screw (not shown) inserted through the flange portion 70 </ b> A is screwed into a screw portion (not shown) provided on the bracket 12, so that the motor 70 is fixed to the bracket 12.

With the structure described above, the rotor 36 is rotated by the motor 70, and as shown in FIG.
When the through hole 38 of 6A opens the idle orifice 60, the main liquid chamber 30 and the first
Is communicated with the sub liquid chamber 32. When the rotor 36 is rotated 180 ° by the motor 70 from this position, and the through hole 38 of the cylindrical portion 36A opens the orifice 62 as shown in FIG. 3, the main liquid chamber is opened via the orifice 62. The 30 and the second sub liquid chamber 96 are communicated.

When the rotor 36 is further rotated by 180.degree. From this position by the motor 70, the idle orifice 60 is opened again as described above.
Thereafter, the orifices are sequentially opened as described above. Accordingly, the orifices 60 and 62 are switched by opening and closing the orifices 60 and 62 so that the idle vibration as the vibration in the low frequency range and the vibration during traveling as the vibration in the high frequency range can be reduced. .

As described above, the arrangement in which the rotor 36 communicates between the main liquid chamber 30 and the first sub liquid chamber 32 through the idle orifice 60 as shown in FIG. 1 and the confinement as shown in FIG. The rotor 36 is rotated by the motor 70 so as to selectively adopt an arrangement for communicating between the main liquid chamber 30 and the second sub liquid chamber 96 via the orifice 62.
The motor 70 is connected to a controller 72 as control means, and its rotation is controlled by the controller 72. The controller 72 is operated by the vehicle power supply, receives detection signals from at least the vehicle speed sensor 74 and the engine speed detection sensor 76, detects the vehicle speed and the engine speed, and can determine whether idle vibration or shake vibration occurs. It has become.

Next, the operation of the present embodiment will be described. When the engine mounted on the vibration isolator 10 connected to the inner cylinder fitting 26 operates, the vibration of the engine is transmitted to the elastic body 28 via the inner cylinder fitting 26. The elastic body 28 acts as a vibration absorbing main body, and can absorb vibration by a vibration damping function based on internal friction of the elastic body 28. Further, the elastic body 2
The liquids in the main liquid chamber 30 and the first sub liquid chamber 32, whose internal volumes change with the deformation of the first and second diaphragms 20, 8 and the like, flow mutually via the shake orifice 64 or the idle orifice 60, and the like. , The main liquid chamber 3 whose internal volume changes with the deformation of the elastic body 28 and the second diaphragm 94
The liquids in the zero and second sub liquid chambers 96 flow mutually via the orifice 62 for spillover, and a vibration damping effect is provided by a damping action based on the viscous resistance of the liquid flow generated in these orifice spaces and liquid column resonance. Can be improved.

In addition to the shake orifice 64 which is always open, an idle orifice 60 and an orifice 62 are provided, and a rotor 36 for switching a passage between the idle orifice 60 and the orifice 62 is provided. As a result, it operates as follows.

For example, when the engine is idling or when the vehicle speed is 5 km / h or less, the idle vibration (2
5Hz). The controller 72 is a vehicle speed sensor 7
4. It is determined by the engine speed sensor 76 whether idle vibration has occurred. When the controller 72 determines that idle vibration has occurred, the controller 72 rotates the motor 70 to rotate the rotor 36 as shown in FIG.
Are arranged so as to correspond to the idle orifices 60 and do not correspond to the orifices 62 for shunting.

As a result, the orifice 62 is closed and the liquid moves between the main liquid chamber 30 and the first sub liquid chamber 32 via the idle orifice 60. Due to column resonance, the dynamic spring constant decreases, and idle vibration is absorbed.

On the other hand, when the vehicle runs at a high speed of, for example, 70 to 80 km / h or more, shake vibration (about 10 Hz) occurs. The controller 72 determines whether or not a shake vibration has occurred based on a vehicle speed sensor 74 and an engine speed detection sensor 76. When the controller 72 determines that the shake vibration is occurring, the controller 72 operates the motor 70 to rotate the rotor 36, as shown in FIG. 3, and associates the through hole 38 with the retraction orifice 62 and the idle orifice 60. And an arrangement that does not correspond to

As a result, the idle orifice 60 is closed, the shake orifice 64, which is always open, connects the main liquid chamber 30 and the first sub liquid chamber 32, and the confinement orifice 62 connects the main liquid chamber 30 to the first liquid chamber 30. Second sub liquid chamber 96
And communicate with. As a result, a pressure change based on the engine vibration generated in the main liquid chamber 30 is transmitted to the liquid in the shake orifice 64 and the orifice 62, and the shake of the liquid is absorbed by the resistance of the liquid. Further, for a low-speed muffled sound (about 80 Hz), which is a high-frequency and small-amplitude vibration that may be generated together with the shake vibration, the liquid column resonates in the short orifice 62 and the dynamic spring constant decreases. Then, this muffled sound is absorbed.

As described above, the main liquid chamber 30 and the sub liquid chambers 32, 96
The two orifices 60, 62, which are respectively opposed to one ends of the two orifices 60, 62 which can communicate with each other to reduce the vibration, are rotated by the motor 70, and the two orifices 60, 62 are rotated. 62 can be selectively opened and closed, and accordingly, vibrations at two different frequencies can be reduced. As a result, the vibration is appropriately absorbed at any vibration frequency, and a wide range of vibration can be reduced.

As shown in FIG. 1, FIG. 3, FIG. 6, and FIG. 7, a thick portion 94B having a large thickness is provided on a part of the second diaphragm 94 which can be elastically deformed. 94B
A through hole 80 provided in the outer tube fitting 16 is disposed in a positional relationship facing the outer tube fitting 16. Therefore, the through-hole 8 faces the thick portion 94B of the second diaphragm 94, which is highly rigid and hard to move.
By providing 0, when liquid flows mutually between the main liquid chamber 30 and the second sub liquid chamber 96 via the squeezing orifice 62, the liquid column resonates in the squeezing orifice 62. In addition, the second diaphragm 94 does not easily come into contact with the periphery of the outer cylinder fitting 16 where the through hole 80 exists, so that the reliability of the second diaphragm 94 is improved. And the second
As a result of the increased reliability of the diaphragm 94, the durability of the vibration isolator 10 is improved.

Further, since the high-rigidity portion of the second diaphragm 94 has a simple structure in which a thick portion 94B in which the thickness of the second diaphragm 94 is partially changed is simply provided, vibration is prevented at low cost. The durability of the device 10 can be improved. On the other hand, in the present embodiment, as shown in FIGS. 6 and 7, three out of the four sides constituting the periphery of the thick portion 94B are prevented from leaking the liquid from the second auxiliary liquid chamber 96. The width D1 of the thick portion 94B is made smaller than the width D2 of the thin portion 94C which is a deformable second diaphragm 94 other than the thick portion 94B. Since the structure was made to have a small area, the rigidity of the thick portion 94B was further increased, making it more difficult to move. For this reason, the through hole 80 facing the thick portion 94B
This makes it more difficult for the second diaphragm 94 to come into contact with the periphery of the portion where the second diaphragm 94 exists, and the reliability of the second diaphragm 94 is further improved.

More specifically, a durability test in which a load is repeatedly applied in the Y direction in FIG. 3 under a load condition in which the second diaphragm 94 shown by a two-dot chain line hits the inner peripheral surface of the outer cylindrical fitting 16 is performed in this embodiment. As a result of performing the vibration isolator 10 according to the embodiment, even after applying a load of nearly 1 million times,
The second diaphragm 94 was satisfactory without any problem. For this reason, it turned out that the anti-vibration device 10 of the present embodiment sufficiently withstands actual use.

At this time, the stopper projection 94D is provided on the second diaphragm 94. However, since the stopper projection 94D is provided near the thick portion 94B, the stopper projection 94D also becomes difficult to move. The second diaphragm 94 can be reciprocated in a stable state in which the second diaphragm 94 does not come into contact with the inner peripheral surface of the outer cylindrical member 16, so that vibration isolation characteristics can be obtained. For this reason, tuning for adjusting the vibration isolation performance can be easily performed by adjusting the hardness of the rubber material, and variation in the vibration isolation performance is reduced.

In the above embodiment, the outer cylinder 1
When press working is performed to provide the through hole 80 in the through hole 6, burrs are generated at the edge portion 80 </ b> A of the through hole 80.
The edge portion 80A of the through-hole 80 facing the thick portion 94B of No. 4 becomes smooth. Therefore, even if the thick portion 94B of the second diaphragm 94 contacts the edge 80A of the through-hole 80, the reliability of the second diaphragm 94 does not decrease,
The durability of the vibration isolator 10 is further improved.

Further, in the above embodiment, the outer cylinder fitting 16 is attached to the vehicle body, and the inner cylinder fitting 26 is attached to the engine.
Although the side is attached, the reverse configuration may be adopted. Also, two sub liquid chambers of the first sub liquid chamber and the second sub liquid chamber are provided, but may be one sub liquid chamber. Only one orifice may be used. The number of the through-holes 80 provided in the outer cylindrical member 16 is not limited to one, and may be plural. The present invention is applied not only to the second diaphragm 94 serving as a membrane, but also to a first partition serving as a partition of the first sub-liquid chamber. 1 diaphragm 20
May be applied.

On the other hand, in the above-described embodiment, the purpose is to dampen an engine mounted on a vehicle, but it goes without saying that the damping device of the present invention can be used for other purposes.
Further, the shape and the like are not limited to those of the embodiment. On the other hand, in the above embodiment, the rotor is configured to be rotated by the motor, but the present invention is not limited to this, and the actuator for rotating the rotor may be other than the motor, and the valve body may be a valve other than the rotor. Etc. may be used, and the rotor may not be provided.

[0054]

As described above, the vibration isolator according to the present invention has the above-described structure, so that it is possible to prevent the elastic film from coming into contact with the periphery of the through hole and to improve the durability. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a vibration isolator according to the present invention (however, legs are omitted), and shows a state in which an idle orifice is opened.

FIG. 2 is a view taken in the direction of arrow 2-2 in FIGS. 1 and 3 (however, legs are omitted).

FIG. 3 is a sectional view showing an embodiment of the vibration isolator according to the present invention (however, legs are omitted), and is a view showing a state in which an orifice for a buried state is opened.

FIG. 4 is a perspective view showing an embodiment of a vibration isolator according to the present invention.

FIG. 5 is a perspective view of an outer cylinder fitting applied to an embodiment of the vibration isolator according to the present invention.

FIG. 6 is an exploded perspective view of a main part of a second diaphragm and an outer tube fitting applied to an embodiment of the vibration isolator according to the present invention.

FIGS. 7A and 7B are diagrams showing a second diaphragm applied to an embodiment of the vibration isolator according to the present invention, wherein FIG. 7A is a front view, and FIG. 7B is a BB view of FIG. FIG.

FIG. 8 is an exploded perspective view of a main part of a first diaphragm and an outer cylinder fitting applied to an embodiment of the vibration isolator according to the present invention.

FIG. 9 is an exploded perspective view of an intermediate block and a rotor applied to an embodiment of the vibration isolator according to the present invention.

10A and 10B are diagrams illustrating an intermediate block applied to an embodiment of the vibration isolator according to the present invention, wherein FIG. 10A is a left side view, FIG. 10B is a bottom view, and FIG. ) Is a right side view.

FIG. 11 is a cross-sectional view of a vibration isolator according to the related art.

12 is a view taken in the direction of arrow 12-12 in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration isolator 16 Outer cylinder fitting 26 Inner cylinder fitting 28 Elastic body 30 Main liquid chamber 62 Orifice 80 for through-hole 94 Second diaphragm 94B Thick part 94A Seal part 96 Second sub liquid chamber

Claims (8)

[Claims] A first mounting member connected to one of the vibration generating section and the vibration receiving section; a second mounting member connected to the other of the vibration generating section and the vibration receiving section and provided with a through hole; An elastic body disposed between these mounting members and capable of being elastically deformed; a main liquid chamber in which the liquid is sealed with the elastic body as a part of the partition wall and whose internal volume changes due to deformation of the elastic body; A sub-liquid chamber which is in communication with the chamber and in which the liquid is sealed, and which has a high-rigidity part in a part and a through-hole is arranged in a positional relationship facing the high-rigidity part, and An elastic film having at least a part formed to be elastically deformable. 2. The vibration damping device according to claim 1, wherein a thick portion having a large thickness is provided on a part of the elastic film, and the thick portion forms a highly rigid portion. 3. The sealing device according to claim 2, wherein three of the four sides around the thick portion are sealed to prevent leakage of liquid from the auxiliary liquid chamber. Anti-vibration device. 4. The vibration isolator according to claim 2, wherein the width of the thick part is smaller than the width of the deformable elastic film other than the thick part. 5. An inner cylinder connected to one of the vibration generator and the vibration receiver, and a through hole formed in a cylindrical shape so as to be connected to the other of the vibration generator and the vibration receiver and surround the inner cylinder. An elastic body which is disposed between the inner cylinder and the outer cylinder and which can be elastically deformed; and a liquid is sealed with the elastic body as a part of the partition wall and the inner volume is changed by the deformation of the elastic body. A main liquid chamber that communicates with the main liquid chamber via a passage, and a sub-liquid chamber that is filled with a liquid; a position having a high-rigidity portion in part and a through hole facing the high-rigidity portion; And an elastic film which is arranged in relation to each other and forms at least a part of the partition wall of the sub liquid chamber so as to be elastically deformable. 6. A protection device according to claim 5, wherein a thick portion for increasing the thickness of the elastic film is provided on a part of the elastic film, and the thick portion constitutes a highly rigid portion. Shaking device. 7. The sealing device according to claim 6, wherein three of the four sides around the thick portion are sealed to prevent leakage of liquid from the auxiliary liquid chamber. Anti-vibration device. 8. The vibration isolator according to claim 6, wherein the width of the thick portion is smaller than the width of the deformable elastic film other than the thick portion.