JPH04266640A - Vibration isolator - Google Patents

Abstract

PURPOSE:To make a vibration isolator compact and enhance the efficiency of the assembling work. CONSTITUTION:Passages 56, 58 serving as idle orifices and a passage 64 serving as a shake orifice are provided in a middle block 24, and a rotor 36 as a limiting means for limiting the liquid flowing to the idle orifices is integrated into the middle block 24 to form one unit. This unit is integrated into an outer cylinder 16 together with a middle block 22. Since the middle block 24 is used as both the member forming the passage and the member forming the limiting means, the efficiency of the assembling work is good. Further, since all the liquid passage and the limiting means for limiting the liquid flow are integrated into the outer cylinder 16, a damping device is made compact.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolating device used in engine mounts of vehicles, particularly automobiles, for absorbing and attenuating vibrations from vibration generating parts.

0002

[Prior Art] A vibration isolating device serving as an engine mount is disposed between the engine and the vehicle body in an automobile engine.
It is designed to prevent engine vibrations from being transmitted to the vehicle body. The vibrations that occur in the engine include the so-called shake vibration that occurs when the vehicle is running at about 70 km/h, and the so-called idling vibration that occurs when the vehicle is idling and when the vehicle is running 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 shake vibration and idle vibration have different frequencies.

A liquid-filled type anti-vibration device has been proposed as a vibration-isolating device that effectively absorbs such wide-frequency vibrations (Japanese Patent Application Laid-open No. 101935/1983).

In this vibration isolator, a main liquid chamber and a sub-liquid chamber filled with liquid are formed inside an outer cylinder, and the main liquid chamber and sub-liquid chamber are connected to a small diameter communication passage and a large diameter communication passage. are connected to each other through. The small-diameter passage always communicates between the main liquid chamber and the sub-liquid chamber, and the large-diameter communication passage communicates between the main liquid chamber and the sub-liquid chamber via an on-off valve provided on the outer circumferential surface of the outer cylinder. ing.

[0005] When the vibration of the engine is low frequency, the on-off valve is closed to allow liquid to flow back and forth only through a small diameter passage. Therefore, vibrations are absorbed by the passage resistance as the liquid moves through the small diameter passage. On the other hand, when the vibration frequency of the engine is high, the small-diameter passage becomes clogged, so the on-off valve is opened to allow communication with the large-diameter communication passage. As a result, the liquid column resonates in the large-diameter communication path, reducing the dynamic spring constant of the vibration isolator and absorbing vibrations.

By the way, in this vibration isolator, since the communication passage and the on-off valve for opening and closing the communication passage are separately provided,
Each of the parts must be assembled separately and then assembled to the outer cylinder, making the assembly work complicated and making it difficult to make the entire vibration isolator compact.

[0007]

SUMMARY OF THE INVENTION In view of the above facts, it is an object of the present invention to provide a vibration isolating device that is compact and allows efficient assembly work.

[0008]

[Means for Solving the Problems] The present invention provides an outer cylinder connected to one of a vibration generating part and a vibration receiving part, an inner cylinder connected to the other of the vibration generating part and a vibration receiving part, and an outer cylinder connected to the other of the vibration generating part and the vibration receiving part. and an elastic body that is provided between the inner cylinder and the inner cylinder and deforms when vibration occurs;
In the vibration isolating device, the vibration isolating device includes a main liquid chamber that can be expanded and contracted using the elastic body as part of a partition wall, and a sub-liquid chamber isolated from the main liquid chamber, in which the main liquid chamber and the sub-liquid chamber communicate with each other. It is characterized in that a unit including a plurality of restriction passages and a restriction means provided in at least one of the restriction passages to restrict the flow of liquid is provided in the outer cylinder.

[0009]

[Operation] Vibration transmitted from the vibration generating section is supported by the vibration receiving section via the elastic body. Vibration is absorbed by resistance based on the internal friction of this elastic body, and also by liquid passage resistance and liquid column resonance generated in the restricted passage between the main liquid chamber and the auxiliary liquid chamber.

[0010] A plurality of restricted passages are provided, one of which is
Since the two restricted passages can be opened and closed by restricting means,
It can be made to correspond to vibrations of different frequencies. In other words, in the case of relatively low-frequency vibrations, by reducing the cross-sectional area of the restriction passage and increasing its length, effective vibration damping is possible due to the resistance when liquid passes through the restriction passage. Vibration is absorbed by a restricted passage with a small cross-sectional area that directly connects the main liquid chamber and the auxiliary liquid chamber. Further, when the frequency of vibration is high, a restriction passage with a small cross-sectional area becomes clogged, so a restriction passage with a large effective cross-sectional area is required. In this case, when the opening/closing means is opened, liquid column resonance occurs in the restricted passage having a large effective cross-sectional area, the dynamic spring constant is reduced, and high-frequency vibrations are damped.

Furthermore, since the restriction passage and the restriction means are integrated into one unit, there is no need to assemble them separately and assemble them into the outer cylinder, which improves the efficiency of the assembly work. moreover,
Since the unit provided with the limiting means is provided inside the outer cylinder, the entire vibration isolator can be made compact.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vibration isolating device 10 according to the present invention will be described with reference to FIGS. 1 to 3.

As shown in FIGS. 1 and 2, this vibration isolator 10 is equipped with a mounting frame 12 for mounting on a vehicle body (not shown), and an outer cylinder is attached to an annular portion 14 of this mounting frame 12. 16 has been inserted. A thin rubber layer 18 is vulcanized and bonded to the inside of this outer cylinder 16. A portion of this thin rubber layer 18 serves as a diaphragm 20 that is separated from the inner peripheral surface of the outer cylinder 16. Furthermore, an intermediate block 22 and an intermediate block 24 constituting a unit are inserted into the outer cylinder 16. The intermediate block 24 has a substantially semicircular block shape when viewed from the axial direction of the outer cylinder 16. The outer peripheral surface of this intermediate block 24 is in close contact with the inner peripheral surface of the thin rubber layer 18. The intermediate block 22 has flange portions 22A formed at both ends in the axial direction, the outer peripheral surface of which is in close contact with the thin rubber layer 18, and the intermediate block 24 is formed between the flange portions 22A.
is inserted. This intermediate block 22 has a notch 22B formed in the center facing the intermediate block 24, through which an inner cylinder 26 passes. This inner cylinder 26 is arranged coaxially with the outer cylinder 16, and a main body rubber 28 as an elastic body is stretched between it and the intermediate block 22. As a result, the inner cylinder 2
6 is movable relative to the outer cylinder 16.

A part of the outer circumferential surface of the main body rubber 28 is in close contact with the top surface 24A of the intermediate block 24, and a notch 28A forming a main liquid chamber 30 between it and the intermediate block 24 is formed in a part of the intermediate part. It is formed. Further, the intermediate block 22 has a sub-liquid chamber 32 formed between the flange portions 22A, the inner peripheral surface of which is partitioned by the intermediate block 22, and the outer peripheral surface of which is partitioned by the thin rubber layer 18 and the diaphragm 20. Diaphragm 2
0 and the outer cylinder 16 is an air chamber 31, which is communicated with the outside as necessary. These main liquid chamber 30 and sub-liquid chamber 32 are filled with liquid such as water and oil.

The intermediate block 24 has a main liquid chamber 30 facing the main liquid chamber 30;
A circular hole 34 is formed in the radial direction of the outer cylinder 16, into which a rotor 36 serving as a restricting means is rotatably inserted, and a thin shaft portion 38 of the rotor 36 passes through the intermediate block 24. Further, an annular washer 37 is screwed into the opening of the circular hole 34 in the intermediate block 24 to prevent the rotor 36 from coming off. An O-ring 39 is fitted in the middle of the thin shaft portion 38 of the rotor 36 to prevent liquid from leaking. On the other hand, the tip of the thin shaft portion 38 is connected to a rotating shaft 44 of a motor 42 via a joint 40. This motor 42 is screwed to a boss 46 fixed to the annular portion 14 of the mounting frame 12, and its rotation is controlled by a control means 48. Note that this control means 48
is driven by the vehicle power supply, and at least the vehicle speed sensor 5
0 and the detection signal from the engine rotation sensor 52,
Vehicle speed and engine rotation speed can be detected.

The rotor 36 has a cylindrical end facing the main liquid chamber 30, and a through hole 54 is formed in a part of the cylindrical circumferential surface. This through hole 54 can communicate with a passage 56 formed in the intermediate block 24 in the radial direction of the circular hole 34. This passage 56 communicates with a passage 58 formed on the outer periphery of the intermediate block 24.
8 communicates with the sub-liquid chamber 32. This passage 56, 58
has a role as an idle orifice 60 as a restriction passage, and is selectively communicated with the main liquid chamber 30 by rotation of the rotor 36.

A passage 64 forming a shake orifice 62 as a restriction passage is formed on the outer peripheral surface of the intermediate block 24.
One end of this passage 64 communicates with the auxiliary liquid chamber 32 at the opposite side to the passage 58 via the inner cylinder 26, and communicates with the main liquid chamber 32 through an opening 64A formed in the inner circumference of the intermediate block 24. It communicates with the liquid chamber 30. Therefore, this passage 64 always communicates the main liquid chamber 30 and the auxiliary liquid chamber 32.

Next, the operation of this embodiment will be explained. When a vehicle runs at a high speed of, for example, 70 to 80 km/h or higher, shake vibration (less than 15 Hz) occurs. The control means 48 uses a vehicle speed sensor 50 and an engine rotation speed sensor 52 to determine whether shake vibration is occurring. When the control means 48 determines that a shake vibration is occurring, the control means 48 operates the motor 42 to rotate the rotor 36 and close the through hole 5.
4 is arranged so as not to correspond to the passage 56. As a result, the passage 56 is closed, and only the shake orifice 62 communicates between the main liquid chamber 30 and the auxiliary liquid chamber 32. As a result, the pressure change caused by the engine vibration occurring in the main liquid chamber 36 is resisted by the liquid passing through the shake orifice 62, and the shake vibration is absorbed.

[0019] Also, when the engine is idling or when the vehicle speed is 5 km/h or less, idle vibration (20
~40Hz) occurs. The control means 48 is a vehicle speed sensor 50
, the engine rotation speed sensor 52 determines whether or not idle vibration is occurring. When the control means 48 determines that idle vibration is occurring, the control means 48 rotates the motor 42 to communicate the through hole 54 of the rotor 36 with the passage 56. As a result, even if the shake orifice 62 becomes clogged, the liquid will flow back and forth between the main liquid chamber 30 and the auxiliary liquid chamber 32 via the idle orifice 60 with low passage resistance, and the liquid column will resonate within the idle orifice 60. The dynamic spring constant is reduced.

Further, in this vibration isolator 10, the passage 56,
58, 64 and the rotor 36 which is the limiting means
Since the intermediate block 24 also serves as a supporting member, the number of parts is reduced compared to when these are formed as separate members, and when assembled to the outer cylinder, it can be assembled as one unit, making assembly easier. Become. Furthermore, since the liquid passage and the means for restricting the liquid flowing through the passage are all provided inside the outer cylinder, the entire vibration isolating device can be made compact. Furthermore, since all liquid flow paths are provided within the outer cylinder, reliability with respect to liquid leakage is high.

[0021] In the embodiment, the idle orifice 60
Although the two restriction passages, ie, the shake orifice 62, are provided, the present invention is not limited to this, and the number of restriction passages is not limited as long as it is plural.

In addition, in the embodiment, the idle orifice 60
Although the liquid flowing into the idler orifice 60 is configured to be restricted by the rotor 36, the present invention is not limited to this, but the present invention may also be configured to restrict the liquid flowing to the idle orifice 60 using other types of restriction means such as a spool valve or a globe valve. good.

[0023]

As explained above, since the vibration isolating device of the present invention has the above structure, it has an excellent effect of being compact and increasing the efficiency of assembly work.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a vibration isolator according to an embodiment of the present invention.

FIG. 2 is a partially sectional view showing a vibration isolator according to an embodiment of the present invention.

FIG. 3 is an exploded perspective view showing the unit.

[Explanation of symbols]

10 Vibration isolation device 16 Outer cylinder 26 Inner cylinder 28　　　　　Body rubber (elastic body) 30 Main liquid chamber 32 Sub-liquid chamber 36 Rotor (limiting means)

Claims (1)

[Claims] 1. An outer cylinder connected to one of the vibration generating part and the vibration receiving part, an inner cylinder connected to the other of the vibration generating part and the vibration receiving part, and a space between the outer cylinder and the inner cylinder. The vibration isolator includes: an elastic body that is provided and deforms when vibration occurs; a main liquid chamber that can be expanded and contracted using the elastic body as part of a partition; and a sub-liquid chamber that is isolated from the main liquid chamber. The unit includes a plurality of restriction passages communicating the main liquid chamber and the auxiliary liquid chamber, and a restriction means provided in at least one of the restriction passages to restrict the flow of liquid. A vibration isolating device characterized by being installed inside.