JP2968923B2 - Anti-vibration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration device used for a vehicle, particularly an engine mount of an automobile, for absorbing and attenuating vibration from a vibration generating portion.

[0002]

2. Description of the Related Art In an automobile engine, an anti-vibration device as an engine mount is disposed between the engine and a vehicle body.
The vibration of the engine is prevented from being transmitted to the vehicle body. The vibration generated in the engine includes so-called shake vibration generated when the vehicle is traveling at about 70 km / h, and so-called idle vibration generated when the vehicle is idling and when the vehicle is traveling at about 5 km / h. . Generally, the shake vibration has a frequency of less than 15 Hz, while the idle vibration has a frequency of 20 to 40 Hz,
The frequency is different between the shake vibration and the idle vibration.

As a vibration isolator that effectively absorbs such a wide frequency vibration, there has been proposed a liquid-filled type vibration elimination device capable of changing the vibration isolation characteristics (Japanese Patent Application Laid-Open No. 4101935).

In this vibration isolator, a main liquid chamber and a sub liquid chamber filled with a liquid are formed in an outer cylinder, and the main liquid chamber and the sub liquid chamber have a small diameter communication path and a large diameter communication path. Through each other. The small-diameter passage always connects the main liquid chamber and the sub-liquid chamber, and the large-diameter communication path connects the main liquid chamber and the sub-liquid chamber via an on-off valve provided on the outer peripheral surface of the outer cylinder. ing.

In this vibration isolator, since the communication passage and the on-off valve for opening and closing the communication passage are separately provided, they must be separately assembled and then assembled to the outer cylinder. It becomes complicated, and it is also difficult to make the whole vibration isolator compact.

On the other hand, in a vibration isolator having inner and outer cylinders as in this vibration isolator, it is difficult to incorporate an on-off valve into the outer cylinder because of the limited space between the inner and outer cylinders.

[0007]

SUMMARY OF THE INVENTION In consideration of the above fact, the present invention is provided with a restriction means for restricting the flow of a fluid in a restriction passage communicating between a main liquid chamber and a sub liquid chamber, and switching vibration damping characteristics. It is an object of the present invention to improve the manufacturability and reduce the size of a vibration isolator which can be realized.

[0008]

According to a first aspect of the present invention, there is provided an outer cylinder connected to one of a vibration generator and a vibration receiver, and an inner cylinder connected to the other of the vibration generator and the vibration receiver. An elastic body provided between the outer cylinder and the inner cylinder and deforming when vibration occurs, a main liquid chamber expandable and contractable as a part of the elastic body as a partition, and the main liquid chamber is isolated from the main liquid chamber. A secondary liquid chamber,
In the vibration isolator provided with, between the outer cylinder and the inner cylinder, a flat portion facing the main liquid chamber, an arc-shaped surface portion substantially along the inner peripheral surface of the outer cylinder, the flat portion and the arc-shaped portion An intermediate block having a thick portion located between the main liquid and the main liquid through an opening hole which is connected to the sub-liquid chamber and opened to the flat surface on the other side. A restriction passage connected to the chamber, and a notch provided in the thick portion and interposed in a part of the restriction passage, and inside the notch,
A restriction means for restricting the flow of the fluid in the restriction passage is provided.

According to a second aspect of the present invention, there is provided the vibration isolator according to the first aspect, wherein the intermediate block communicates the main liquid chamber and the sub liquid chamber with each other. It is characterized by having a passage.

[0010]

In the vibration isolator according to the first aspect, the outer cylinder is connected to one of the vibration generator and the vibration receiver, and the inner cylinder is connected to the other of the vibration generator and the vibration receiver. When the vibration of the vibration generator is input to the vibration isolator, the elastic body is deformed and the main liquid chamber expands and contracts. This allows the fluid to resonate with the liquid column in the restriction passage, thereby obtaining an anti-vibration effect. Further, when it is desired to restrict the flow of the liquid in the restriction passage, this can be performed by using restriction means.

The intermediate block provided between the outer cylinder and the inner cylinder has a thick portion located between a flat portion facing the main liquid chamber and an arcuate surface portion substantially along the inner peripheral surface of the outer cylinder. Has,
A notch is provided in a thick portion having a sufficient space, and a restricting means for restricting the flow of fluid in the restricting passage is provided in the notch.Therefore, a restricting means such as an on-off valve is provided outside the outer cylinder. It is possible to reduce the size of the conventional vibration isolator. Furthermore, since the restriction passage is provided in the intermediate block, the restriction passage such as the on-off valve is installed outside the outer cylinder. Also, reliability against liquid leakage is improved.

In the vibration damping device according to the second aspect, the flow of the liquid in the restriction passage is restricted by the restriction means.
The fluid can resonate in the liquid column in the second restriction passage to obtain an anti-vibration effect. For example, by setting the liquid column resonance frequency of the restriction passage higher than the liquid column resonance frequency of the second restriction passage, vibration of low frequency is prevented by the liquid column resonance action of the restriction passage, and the restriction passage is clogged. Can be prevented by the liquid column resonance action of the second restriction passage.

[0013]

FIG. 1 shows an embodiment of a vibration isolator 10 according to the present invention.
3 will be described with reference to FIG.

As shown in FIG. 2, the vibration isolator 10 is provided with a mounting frame 12 for mounting on a vehicle body (not shown). Are arranged. A thin rubber layer 18 is vulcanized and bonded to the inner peripheral surface of the outer cylinder 16.
Part of the diaphragm 20 is separated from the inner peripheral surface of the outer cylinder 16.
It has been. As shown in FIG. 1, an air chamber 31 is provided between the diaphragm 20 and the outer cylinder 16 and communicates with the outside as needed.

As shown in FIG. 2, an intermediate block 22 and an intermediate block 24 are inserted into the outer cylinder 16.

As shown in FIG. 1, the intermediate block 24 has a substantially semicircular block shape when viewed from the axial direction of the outer cylinder 16 and has an outer peripheral arc shape having a shape along the inner peripheral surface of the outer cylinder 16. Surface 24E and a plane portion 24B formed on the opposite side of the outer peripheral arcuate surface 24E.
Is a thick portion 24F. Outer arcuate surface 24E
Is in close contact with the inner peripheral surface of the thin rubber layer 18,
B faces a main liquid chamber 30 described later. The intermediate block 24 forms an on-off valve as a pair with a rotor 36 described later.

As shown in FIG. 2, flanges 22A are formed at both ends in the axial direction of the intermediate block 22, and an intermediate block 24 is fitted between the flanges 22A. Further, the outer peripheral surface of the flange portion 22A has a thin rubber layer 1
8 is adhered to the inner peripheral surface.

As shown in FIG. 1, a cutout portion 22B is formed in the intermediate block 22 at the center of the intermediate block 24 on the plane portion 24B side, and an inner cylinder 26 extends therethrough. The inner cylinder 26 is arranged coaxially with the outer cylinder 16, and
An elastic body 28 is stretched between the first and second members. Thus, the inner cylinder 26 can be moved relative to the outer cylinder 16.

The elastic body 28 also extends to the outer peripheral surface between the flange portions 22A of the intermediate block 22, and a part thereof is in close contact with the inner peripheral circular surface 24A of the portion protruding from the end of the intermediate block 24. . Further, the inner cylinder 2 is provided at an intermediate portion of the elastic body 28.
6, a notch 28A is formed on the lower side.
A main liquid chamber 30 is formed between A and the intermediate block 24.

On the other hand, the flange portion 22 of the intermediate block 22
Between A, there is formed a sub liquid chamber 32 surrounded by the intermediate block 24, the thin rubber layer 18 and the diaphragm 20. The main liquid chamber 30 and the sub liquid chamber 32 are filled with liquid such as water and oil.

The intermediate block 24 is formed with a circular hole 34 as a cutout on the side of the plane portion 24B, and the bottom surface of the circular hole 34 has a diameter smaller than that of the circular hole 34 so that the intermediate block 24 has a smaller diameter.
The circular through hole 35 penetrating the outer peripheral surface of the outer cylinder 16 side of the
4 is formed coaxially. Also, the intermediate block 24
A counterbore 39 is provided coaxially with the circular through-hole 35 on the outer cylinder 16 side, and an annular groove 43 in which an O-ring 41 for sealing is fitted outside the counterbore 39 is provided. ing.

A rotor 36 as a valve is rotatably inserted into the circular hole 34 and the circular through hole 35. The rotor 36 has a cylindrical portion 36A on the main liquid chamber 30 side, and a thin shaft portion 38 is integrally provided on the opposite side. An annular concave portion 24C is formed coaxially with the circular hole 34 on the plane portion 24B side of the intermediate block 24, and an annular washer 40 having a hole 40A is screwed into the annular concave portion 24C to allow the rotor 36 to come out. Preventing.

A narrow groove 42 is formed on the outer periphery of the thin shaft portion 38, and an O-ring 44 is fitted in the narrow groove 42. The O-ring 44 prevents the liquid from leaking out of the intermediate block 24 through the circular through hole 35.

The cylindrical portion 36A has a through hole 46 communicating the inside and outside of the cylindrical portion 36A. On the other hand, a passage 56 is formed in the intermediate block 24 in the radial direction of the circular hole 34, and one of the passages 56 is opened on the inner periphery of the circular hole 34. The other end of the passage 56 communicates with one end of a passage 58 formed on the outer periphery of the intermediate block 24 along the circumferential direction, and the other end of the passage 58 communicates with the auxiliary liquid chamber 32.

Therefore, when the rotor 36 is rotated and the through hole 46 of the cylindrical portion 36A corresponds to the passage 56, the main liquid chamber 30 and the sub liquid chamber 32 are communicated. Note that these passages 56 and 58 have a role as an idle orifice 60 as a restriction passage for absorbing idle vibration.

On the outer peripheral surface of the intermediate block 24, a passage 64 is formed. One end of the passage 64 opens to an end 24 </ b> D of the intermediate block 24 on the passage 58 side and is connected to the auxiliary liquid chamber 32. The passage 64 has a passage 5 in the middle.
It is bent in a U-shape near the end 24G on the opposite side to the 8 side,
The other end communicates with the main liquid chamber 30 via the through hole 65.
The passage 64 and the passage 65 serve as a shake orifice 62 as a second restriction passage for absorbing shake vibration.

On the other hand, the outer cylinder 16 and the thin rubber layer 18 have
A circular hole 66 having a diameter larger than that of the circular through hole 35 is provided at a position corresponding to the circular through hole 35 of the intermediate block 24, and the annular portion 14 corresponds to the circular through hole 35 of the intermediate block 24. A large-diameter circular hole 68 having a larger diameter than the circular hole 66 of the outer cylinder 16 is provided at the position indicated by the arrow.

A motor 70 as an actuator is disposed outside the annular portion 14 at a position corresponding to the large-diameter circular hole 68. The case 72 of the motor 70 is provided with a flange portion 74, which is formed in an arc shape along the outer diameter of the annular portion 14 of the mounting frame 12. The flange 74 has a pair of mounting holes 76.
(Only one of them is shown in FIG. 1), and a screw 78 inserted through these mounting holes 76 is
The motor 70 is fixed to the annular portion 14 by being screwed into a screw portion (not shown) provided in the 4.
Note that the diameter of the mounting hole 76 is a so-called fool hole that is slightly larger than the outer diameter of the screw portion of the screw 78, and the motor 70 is slightly positioned in the axial direction and the circumferential direction of the annular portion 14. Can be adjusted.

The rotating shaft 71 of the motor 70 has a tip formed in a half-moon shape in cross section (see FIG. 3), and has a large diameter circular hole 68 of the annular portion 14 and a circular hole 66 of the outer cylinder 16 for the rotor 36.
Connection hole 3 having a semicircular cross section formed at the tip side of the thin shaft portion 38
8A (see FIG. 3).

Further, in the case 72 of the motor 70,
A boss 82 is provided coaxially with the rotation shaft 71. The outer diameter of the boss 82 is smaller than the inner diameter of the counterbore 39 by a predetermined dimension, and the boss 82 and the counterbore 39 constitute a so-called spigot portion. Therefore, the boss 82 is fitted into the counterbore portion 39 of the intermediate block 24 without play.

The motor 70 is connected to a control means 48, the rotation of which is controlled by the control means 48. The control unit 48 is driven by the vehicle power supply, receives detection signals from at least the vehicle speed sensor 50 and the engine speed detection sensor 52, detects the vehicle speed and the engine speed, and can determine whether idle vibration or shake vibration occurs. It has become.

Next, the order of assembling the vibration isolator 10 will be described. First, the O-ring 4 is inserted into the circular hole 34 of the intermediate block 24.
4 is inserted, and the annular washer 40 is screwed. This intermediate block 24 is
The intermediate block 22 and the intermediate block 24 are inserted into the outer cylinder 16 in the liquid.

Next, the direction of the circular hole 66 of the outer cylinder 16 and the circular through-hole 35 of the intermediate block 24 are aligned, the inside of the outer cylinder 16 is reduced by a predetermined amount, and both ends of the outer cylinder 16 are caulked. 24 and the intermediate block 22 are fixed. As a result, the thin rubber layer 18 is brought into close contact with the outer peripheral surfaces of the intermediate block 24 and the intermediate block 22, and the inside is sealed.

Next, the direction of the circular hole 66 of the outer cylinder 16 is aligned with the large-diameter circular hole 68 of the annular portion 14 of the mounting frame 12, and the outer cylinder 16 is pressed into the annular portion 14.

Thereafter, the rotating shaft 71 of the motor 70 is fitted into the connection hole 38A of the rotor 36, and the motor 70 is screwed to the annular portion 14.

Since the boss 82 provided coaxially with the axis of the rotating shaft 71 of the motor 70 is fitted into the counterbore portion 39 provided coaxially with the axis of the rotor 36, the rotating shaft 71 is provided. Is fitted into the connection hole 38A of the rotor 36, the axis of the rotor 36 and the axis of the rotating shaft 71 of the motor 70 exactly match. For this reason, the rotor 36 and the rotating shaft 71 can rotate smoothly after assembly, and the operation is reliably performed.

Next, the operation of this embodiment will be described. When the vehicle travels at a high speed of, for example, 70 to 80 km / h or more, shake vibration (less than 15 Hz) occurs. The control means 48 determines whether or not a shake vibration has occurred based on a vehicle speed sensor 50 and an engine speed detection sensor 52. When the control means 48 determines that the shake vibration is occurring, the control means 48 operates the motor 70 to rotate the rotor 36 so that the through-hole 46 does not correspond to the passage 56. As a result, the passage 56 is closed, and only the shake orifice 62 connects the main liquid chamber 30 and the sub liquid chamber 32. Thus, the pressure change based on the engine vibration generated in the main liquid chamber 36 receives the resistance of the liquid passing through the shake orifice 62, and the shake vibration is absorbed.

When the engine is idling or the vehicle speed is 5 km / h or less, idle vibration (20 to
40 Hz). The control means 48 determines whether or not idle vibration has occurred by the vehicle speed sensor 50 and the engine speed detection sensor 52. When the control means 48 determines that idle vibration has occurred, the control means 48 rotates the motor 70 to make the through hole 46 of the rotor 36 communicate with the passage 56. As a result, even if the shake orifice 62 is clogged, the liquid can pass through the idle orifice 60 having a small resistance.
Between the main liquid chamber 30 and the sub liquid chamber 32 through the liquid column, the liquid column resonates in the idle orifice 60, and the dynamic spring constant is reduced. In this vibration isolator 10, the restriction passage is provided in the intermediate block 24, and the restriction means for restricting the flow of the fluid in the restriction passage is provided in the notch provided in the thick portion, so that the opening and closing of the outer cylinder is performed. It is more compact than a conventional vibration isolator provided with limiting means such as a valve.

Further, when a restricting means such as an opening / closing valve is attached to the outside of the outer cylinder, there is no need to route the restriction passage to the outside of the outer cylinder, so that productivity is improved and reliability against liquid leakage is also improved. I do. In this embodiment, the rotor is 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.

The valve used in the vibration isolator of the present embodiment is configured to open and close the restriction passage by rotation of the rotor. However, the present invention is not limited to this.
A valve other than the configuration shown in the present embodiment may be used as long as it is a valve that opens and closes the restricted passage by rotating the rotation shaft.

[0041]

As described above, the vibration damping device of the present invention has the above-described structure, and therefore, the conventional vibration damping device is provided with limiting means such as an on-off valve for controlling the flow of fluid outside the outer cylinder. On the other hand, it has an excellent effect of being compact, improving the manufacturability, and improving the reliability against liquid leakage.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing one embodiment of a vibration isolator according to the present invention.

FIG. 2 is an exploded perspective view showing one embodiment of the vibration isolator according to the present invention.

FIG. 3 is a perspective view showing a rotor, an intermediate block, and a periphery of a motor (excluding an outer cylinder and a mounting frame) of the vibration isolator according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration isolator 16 Outer cylinder 24 Intermediate block 24B Plane part 24E Outer peripheral arc surface (arc surface) 24F Thick part 26 Inner cylinder 28 Elastic body 30 Main liquid chamber 32 Sub liquid chamber 34 Circular hole (notch) 36 Rotor (restriction) Means) 40A hole 60 Idle orifice (restricted passage) 62 Shake orifice (second restricted passage)

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16F 13/06-13/30 B60K 5/12

Claims (2)

(57) [Claims] An outer cylinder connected to one of the vibration generator and the vibration receiver; an inner cylinder connected to the other of the vibration generator and the vibration receiver; and between the outer cylinder and the inner cylinder. An elastic body that is provided and deforms when vibration occurs, a main liquid chamber that can expand and contract using the elastic body as a part of a partition wall, and a sub liquid chamber that is isolated from the main liquid chamber. Between the outer cylinder and the inner cylinder, a flat portion facing the main liquid chamber, an arcuate surface portion substantially along the inner peripheral surface of the outer cylinder, and a thickness located between the flat portion and the arcuate surface portion. An intermediate block having a meat portion, wherein the intermediate block has a restriction passage connected to the main liquid chamber through an opening hole which is connected to the sub liquid chamber and the other is opened to the flat surface, A notch provided in the thick portion and interposed in a part of the restriction passage, wherein the notch is provided inside the notch. Vibration damping device being characterized in that a limit means for limiting the flow of fluid in the passage. 2. The vibration isolator according to claim 1, wherein the intermediate block is provided with a second restriction passage communicating the main liquid chamber and the sub liquid chamber.