JPH01116330A - Vibration damper - Google Patents

Abstract

PURPOSE:To enable the vibration in a wide frequency range to be absorbed by providing a pair of liquid chambers arranged on an opposite side via an inner cylinder and a plurality of auxiliary chambers which thin wall portions on an elastics body between the restricted conduits communicating the liquid chambers and each liquid chamber formed within the elastic body. CONSTITUTION:When vibration is shake vibration or roll vibration of low frequency and large amplitude, the vibration is absorbed by passing resistance against the liquid in one side liquid chamber, moving to the other side liquid chamber through a restriction passage 30 owing to a pressure increase in the one side liquid chamber 22 or 24. Although the thin wall portion 36 on the pressure rise side is deformed during this vibration, it makes only an auxiliary chamber 32 or 34 come into close contact, so the sufficient pressure change rate for passing through the restriction passage 30 can be secured. When the vibration has a high frequency and a very small amplitude, the liquid within the restriction passage 30 is put in plugged condition, however, the pressure rise within the liquid chamber 22, 24 is restricted by making the thin wall portion 36 to be deformed elastically through the vibration of very small amplitude and the deformation rate to the degree of placing the auxiliary chambers 32, 34 into contact can be never produced because of the very small amplitude. Consequently, the vibration across a wide frequency range can be absorbed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a so-called bush-type vibration isolator in which an elastic body is stretched between an inner cylinder and an outer cylinder, and particularly relates to a so-called bush type vibration isolator that is used to prevent vibration over a wide range. This invention relates to a vibration isolator that takes absorption into account.

[Background technology]

BACKGROUND OF THE INVENTION As a vibration isolating device used in vehicle engine mounts, bushings, engine roll stoppers, etc., there is a so-called bush type structure in which an elastic body is stretched between an inner and outer cylinder. In this vibration isolator, an inner cylinder and an outer cylinder are arranged on parallel axes, and an elastic body is stretched between them, so that one of the inner cylinder and the outer cylinder goes to the vibration generating part, and the other goes to the vibration support part. is connected to. Inside the elastic body, a pair of liquid chambers are provided on opposite sides of the inner cylinder and communicated through a restricted passage. When vibration occurs, an increase in pressure in one liquid chamber causes the liquid to pass through the restricted passage to the other liquid chamber. Vibration is absorbed by the resistance when liquid flows.

However, when the vibration becomes a high frequency, the liquid in the restricted passage becomes clogged, making it impossible to absorb the vibration, increasing the dynamic spring constant, and making the vehicle ride uncomfortable. For this reason, a vibration isolator equipped with an elastic membrane to avoid an increase in pressure in the liquid chamber during high-frequency vibration has been proposed (Japanese Patent Laid-Open No. 61-9
No. 705, JP-A-62-118133, JP-A-62-
No. 124334). However, in all of these, the elastic bodies between the inner and outer cylinders are divided, or a thin elastic body is interposed between the inner and outer cylinders separately from these elastic bodies, so the structure is complex and the assembly work is difficult. It becomes complicated.

The present invention has been made in consideration of the above-mentioned facts, and an object of the present invention is to provide a vibration isolating device that does not require providing a thin elastic body separately from the elastic body between the inner and outer cylinders for absorbing high-frequency vibrations.

[Summary and operation of the invention]

The present invention provides a vibration isolator in which an elastic body is spanned between an inner and outer cylinder, one of which is connected to a vibration generating part and the other to a vibration support part, and which is provided on the opposite side of the inner cylinder. a pair of liquid chambers, a restriction passage that communicates these liquid chambers, and a plurality of sub-chambers formed within the elastic body and in which the elastic body between the liquid chambers is a thin wall portion. It is said that

In this way, in the present invention, a sub-chamber is provided in the elastic body, and the elastic body between the sub-chamber and the liquid chamber is formed into a thin-walled part, so that when the pressure in the liquid chamber increases, this thin-walled part is deformed and the sub-chamber is closed. By changing the volume of the fluid chamber, it is possible to limit the pressure increase in the liquid chamber during high-frequency vibrations and improve riding comfort.

[Embodiments of the invention]

FIG. 1.2 shows a vibration isolating device 10 according to a first embodiment of the present invention.
It is shown.

In this vibration isolator 10, an inner cylinder 12 and an outer cylinder 14 are arranged coaxially, and an intermediate cylinder 16 is press-fitted inside the outer cylinder 14. An elastic body 18 is provided between the intermediate cylinder 16 and the inner cylinder 12.
is vulcanized and bonded and is substantially spanned between the inner cylinder 12 and the outer cylinder 14.

A notch 20 is formed in the intermediate cylinder 16 on the opposite side of the inner cylinder 12, and a recess is provided in the elastic body 18 in continuation with this notch 20. Filled liquid chambers 22, 24 are provided. These liquid chambers 22 and 24 are isolated from the outside by closing the notch 20 with the outer cylinder 14. Moreover, these liquid chambers 22.
In order to improve the sealing performance of the outer cylinder 14, a ring groove 25 (FIG. 4) is arranged on the outer periphery of the intermediate cylinder 16 near both ends in the axial direction.

A stopper 18 is provided on a part of the elastic body 18 so as to protrude into the liquid chambers 22 and 24, and is used for contact with the outer cylinder 14 to limit the amount of movement of the inner and outer cylinders.

A notch is formed in the outer periphery of the intermediate cylinder 16 around the axis of the inner cylinder 12 to form a restriction passage 30 between the intermediate cylinder 16 and the inside of the outer cylinder 14 . Both longitudinal ends of the restriction passage 30 communicate with the liquid chamber 22 and the liquid chamber 24, respectively. Therefore, the liquid chamber 22,
24 are communicated with each other via this restricted passage 30.

Here, subchambers 32 and 34 are provided in the elastic body 18 adjacent to the liquid chambers 22 and 24, respectively. These subchambers 32
, 34 extend in the axial direction of the inner cylinder 12 and pass through the elastic body 18, as shown in FIG. Furthermore, these auxiliary chambers 32 and 34 have a thin wall portion 36 between them and the liquid chambers 22 and 24, and when the pressure in the liquid chambers 22 and 24 changes, the auxiliary chambers 32 and 34 are elastically deformed as shown in FIG. The volume can be changed.

These auxiliary chambers 32 and 34 are located approximately 1 to 3 mm from the liquid chamber wall, and the width dimension (vertical dimension in Figure 1.2) is 1 to 2 m.
About 1 Il is preferred.

When manufacturing this vibration isolating device 10, an elastic body 18 is vulcanized and bonded between the vibration isolating bag W10 and the intermediate cylinder 16.

In this case, sub-chambers 32 and 34 are formed in the elastic body 18 in advance. For this purpose, these subchambers 32.
A mold (core) corresponding to 34 may be projected into the mold.

The integrated inner cylinder 12 and intermediate cylinder 16 are brought into the liquid, inserted into the outer cylinder 14, and the diameter of the outer cylinder 14 is reduced.
The vibration isolator 10 shown in FIG. 2 is completed.

Engine vibration is low frequency and large amplitude (0 to 207, amplitude ±0
．． In the case of shake vibration or roll vibration of 5 mm or more, the pressure in one of the liquid chambers increases and the liquid flows into the restriction passage 3.
Vibration is absorbed by the passage resistance when moving to the other liquid chamber through 0. Also, during this vibration, the thin wall portion 36 on the side where the pressure has increased is elastically deformed, but this elastic deformation occurs only until the auxiliary chamber 32 or 34 is in close contact with each other as shown in FIG. It is possible to secure a sufficient amount of pressure change to

In addition, the vibration is high frequency and minute amplitude (207 or more, amplitude ±0.5
mm or less), the fluid in the restriction passage 30 becomes clogged. However, in this case, the thin-walled portion 36 is elastically deformed by this minute amplitude vibration, and the liquid chamber 22.2
4. Limit the pressure rise. Since the vibration in this case has a very small amplitude, the amount of deformation that causes the auxiliary chamber 34 to come into close contact with each other does not occur.

In this way, vibration absorption over a wide range of frequencies becomes possible.

FIG. 5 shows a second embodiment of the invention.

In this embodiment, the auxiliary chambers 32 and 34 of the previous embodiment are divided in the middle by a partition 38, but the same effects as in the previous embodiment can be obtained.

Next, FIG. 6.7 shows a vibration isolator according to a third embodiment of the present invention. In this embodiment, unlike the first embodiment, one auxiliary chamber 32.34 is formed for each liquid chamber 22.24. These auxiliary chambers 32 and 34 are not penetrated in the axial direction of the elastic body 18, unlike the first embodiment.
It communicates with oval notches 44 and 46 formed in the intermediate cylinder 16. However, these notches 44 and 46 are
6 is closely attached to the inside of the outer cylinder 14, and is therefore cut off from the outside. Moreover, these notches 44 and 46 are formed in the intermediate cylinder 16.
are communicated with each other by a bottomed groove 48 formed on the outer periphery of the two.

Therefore, in this embodiment, the restriction passage 30 is not formed in the portion where the bottomed groove 48 is formed, and only on the opposite side of the inner cylinder 12 (the left side of the inner cylinder 12 in FIG. 7). A restricted passage 30 is provided.

When this embodiment is applied to an engine roll mount, in addition to the liquid chambers 22 and 24, the auxiliary chambers 32 and 34 are also filled with a liquid such as ethylene glycol or silicone. In this case, the liquid chamber 22 and the sub-chamber 32 and/or the liquid chamber 24 and the sub-chamber 34 may be communicated through a small hole or the like. Bottomed groove 48
has a sufficiently larger cross-sectional area than the restriction passage 30 to reduce the resistance of fluid flowing between the auxiliary chambers 32 and 34.

Furthermore, in this embodiment, a thin elastic body 50 is interposed to bring the intermediate cylinder 16 and the outer cylinder 14 into close contact with each other, in addition to the liquid chamber 22.24, and also to make the auxiliary chamber 32.34 liquid-tight with the outside. ing.

In this embodiment as well, during low frequency and large amplitude vibrations, the auxiliary chamber 3
2 or the sub-chamber 34 are in a close contact state due to the deformation of the thin wall ji 36, so the liquid does not flow in the bottomed groove 48, and the liquid in the liquid chambers 22 and 24 flows only through the restricted passage 30, resulting in a large damping force. . This damping force can be adjusted to match the roll and shake vibrations of the engine.

Furthermore, during vibrations of high frequency and small amplitude, the sub-chambers 32 and 34 on the side where the internal pressure has increased are reduced and brought into close contact by the deformation of the thin-walled portion 36, and the liquid in the sub-chambers on the side that has been reduced and brought into close contact passes through the bottomed groove 48 to the other sub-chamber 32 and 34. Since the liquid flows into the liquid chamber without resistance, even if the restriction passage 30 becomes clogged, the liquid pressure does not increase and a low spring constant can be maintained.

The auxiliary chambers 32 and 34 in this embodiment may be air chambers similar to those in the previous embodiment, and communicated with the atmosphere through small holes or the like.

Next, FIGS. 9 and 10 show a fourth embodiment of the present invention. In this embodiment, as shown in FIG. 11, bottomed hollow parts 56 are formed on the opposite side of the inner cylinder 12 through the intermediate cylinder 16 and the elastic body 18, and the rubber is inserted into the hollow parts 56 in the radial direction. Subchambers 32, 34 are formed by inserting the block 58.

That is, the rubber block 58 has an inner metal fitting 60 abutted against the bottom of the hollowed part 56 at one end, and an outer cylinder 14 at the other end.
An outer metal fitting 62 that comes into contact with the metal fitting 62 is vulcanized and bonded, and a circular through hole 64 is formed in the middle part. In addition, this rubber block 58 has a front surface 58A and a back surface 58B that are connected to the liquid chamber 22.
4, and a gap is formed between the thin wall portions 36 and the thin wall portions 36 to form subchambers 32 and 34. Therefore, these subchambers 32.
34 are communicated with each other via a circular hole 64.

Both sides 58C and 58D of the rubber block 58 are slotted portions 5.
It has a recessed shape with respect to the inner metal fitting 60 and the outer metal fitting 62 so as to form a slight gap between the metal fitting 60 and the inner circumference of the metal fitting 6 to prevent wear during relative movement.

In addition, the front surface 58A1 and the back surface 58B are recessed relative to the inner metal fitting 60 and the outer metal fitting 62 to form the auxiliary chambers 32 and 34, and are designed to limit the amount of movement of the thin wall portion 36 during elastic deformation. ing.

In this embodiment, since the rubber blocks 58 are disposed on both sides of the inner cylinder 12, the restriction passage 30 is formed as a bottomed groove on the outside of the intermediate cylinder 16 in line with the hollowed out part 56, as shown in FIG. It has become so.

Therefore, in this embodiment, after the inner cylinder 12 and the intermediate cylinder 16 are integrally fixed to the elastic body 18, they are brought into the liquid, and in this liquid, the rubber block 58 is inserted into the hollowed part 56, and the outer cylinder 14 to the outer periphery of the intermediate cylinder 16, it becomes possible to simultaneously fill the auxiliary chamber 32.34 with liquid in addition to the liquid chamber 22.24. Note that the inner metal fitting 60 or the outer metal fitting 62 attached to the rubber block 58 can be omitted. In this case, the end shape of the rubber block 58 may be formed into the shape of the inner metal fitting 60 or the outer metal fitting 62.

Further, it is preferable that the length of the rubber block 58 is 10 to 20% longer than the depth of the hollow portion 56 so that the rubber block 58 is compressed in the length direction between the inner and outer cylinders during assembly.

Next, FIGS. 14 and 15 show a fifth embodiment of the invention. In addition to the fourth embodiment, this embodiment has a thin wall portion 36.
A canvas 66 is enclosed around the hollowed out part 56 including the inner part, thereby improving the durability of the thin part 36. This canvas 66 can be made of nylon or the like, but other fibers may also be used.

This canvas 66 is wrapped around the outer periphery of a mold (core) for forming the hollow portion 56 during manufacture, and in this state, the elastic body 18 is vulcanized to be integrally enclosed within the elastic body 18. Can be done.

Next, FIG. 16 shows a sixth embodiment of the present invention.

In this embodiment, as in the fifth embodiment, a rubber block 58 is inserted into the hollow portion 56 to form the auxiliary chamber 32,34, but this rubber block 58 is provided only on one side of the inner cylinder 12. ing. The inner cylinder 1 is located at an interval of approximately 120° from the area where the rubber block 58 is provided, centering on the inner cylinder 12.
An elastic body 18 is disposed between the rubber block 2 and the intermediate cylinder 16, and a liquid chamber 22 is formed between the elastic body 18 and a thin wall portion 36 disposed on one side of the rubber block 58.

Also, the thin wall portion 36 disposed on the opposite side of the rubber block 58
The liquid chamber 24 faces the liquid chamber 24, and the opposite side of the liquid chamber 24 is constituted by a diaphragm 70.

This diaphragm 70 is stretched between the elastic body 18 and the intermediate cylinder 16.
The elastic body 18 is not interposed between the inner periphery of the elastic body 6 and the surface of the elastic body 18 on the side opposite to the liquid chamber 22, forming a notch 72. An elastic stopper 74 protrudes from the inner periphery of the intermediate cylinder 16 within this notch 72 .

Further, a restriction passage 30 is formed between the intermediate cylinder 16 and the outer cylinder 14, and this restriction passage 30 goes around the notch 72 and has both longitudinal ends communicated with the liquid chambers 22 and 24, respectively. There is. Both ends of the restriction passage 30 in the axial direction (direction perpendicular to the plane of the paper in FIG. 16) are sealed with elastic bodies (not shown).

Therefore, in this embodiment as well, the liquid chambers 22 and 24 communicate with each other via the restriction passage 30, and subchambers 32 and 34 are formed in these liquid chambers 22 and 24 via the thin wall portion 36.

〔Effect of the invention〕

As explained above, the present invention provides an auxiliary chamber to the liquid chamber through the thin wall portion, and therefore has an excellent effect of being able to absorb vibrations over a wide frequency range.

[Brief explanation of the drawing]

FIG. 1 shows a second embodiment of the vibration isolating device according to the first embodiment of the present invention.
A cross-sectional view corresponding to the cross section taken along the line I-I in Figure 2.
3 is a sectional view showing the operating state of FIG. 1, FIG. 4 is an exploded perspective view showing the relationship between the intermediate cylinder and the outer cylinder of the first embodiment, and FIG. 5 is the invention of the present invention. 6 is a sectional view corresponding to FIG. 1 showing a third embodiment of the present invention, and a sectional view taken along the line VI-Vl in FIG. 7, 7 is a sectional view taken along the line ■-■ in FIG. 6, FIG. 8 is an exploded perspective view of the third embodiment, and FIG. 9 is a sectional view corresponding to FIG. 1 showing the fourth embodiment of the present invention. Fig. 10 is a sectional view taken along the line X-X of Fig. 9, Fig. 11 is an exploded sectional view of the fourth embodiment with the rubber block removed, Fig. 12 is a side view of the intermediate cylinder, and Fig. 12 is a side view of the intermediate cylinder.
3 is an exploded perspective view showing the correspondence between the intermediate cylinder and the rubber block, FIG. 14 is a sectional view taken along the line XrV-XIV, and FIG. 15 corresponds to FIG. 1, showing the fifth embodiment of the present invention. is a sectional view taken along the line xv-xv in FIG. 14, and FIG.
FIG. 2 is a sectional view corresponding to FIG. 1 showing the embodiment. DESCRIPTION OF SYMBOLS 10... Vibration isolator, 12... Inner cylinder, 14... Outer cylinder, 18... Elastic body, 22.24... Liquid chamber, 30... Restriction passage, 32.34... - Sub-chamber, 36... Thin wall, 58... Rubber block. Figure 1 10: Anti-vibration 1itz 12: Internal crystal 14: Kuto 18: Ri1-to! 4 pieces 22.24 :ha i 32.34 :! Li i 36: Thin wall ¥42 Figure 1 30: System PP < Passage Figure 3 Figure 4 Figure 5 Figure 6 ■-2! ■2 Figure 7 Figure 9

Claims (1)

[Claims] (1) A vibration isolator in which an elastic body is stretched between the inner and outer cylinders, one of the inner and outer cylinders is connected to a vibration generating part and the other to a vibration support part, and is provided on the opposite side of the inner cylinder. It is characterized by having a pair of liquid chambers, a restriction passage that communicates these liquid chambers, and a plurality of sub-chambers formed within the elastic body and having thin-walled elastic bodies between the liquid chambers. Anti-vibration device.