JPS62224744A - Liquid seal type vibrationproof device - Google Patents

Abstract

PURPOSE:To effectively damp the vibration in all the directions by arranging an elastic body between the inner and outer cylinders in coaxial form and forming four liquid chambers partitioned above and below in the axial direction by the partitioning walls at the symmetrical positions in the transverse direction around the axis center of the inner cylinder in the elastic body and allowing these chambers to communicate through orifices. CONSTITUTION:As for an elastic body 13 interposed between an outer cylinder 11 and an inner cylinder 12 in coaxial form, liquid chambers 14-17 are formed inside. The liquid chamber is divided into the upper and lower stages at the symmetrical positions in the transverse direction by a partitioning wall 18, forming four chambers. The upper and lower edge walls of the elastic body forming each liquid chamber are formed so as to be compression-deformed by a load in the axial direction. As for each liquid chamber, the liquid chambers positioned in the vertical direction or in the direction of diagonal line are allowed to communicate independently through the first and the second orifices 29 and 30. Therefore, the loss factor of the vibration in the axial direction is increased together with the expansion spring action of the partitioning walls and the lower edge wall, and also the vibration in the longitudinal direction can be effectively damped.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a liquid-filled vibration isolator which damps vibrations, particularly in the axial direction of the device.

BACKGROUND OF THE INVENTION Conventional liquid-filled vibration isolators of this type include, for example, the first
1 and 2 are known (see Japanese Patent Laid-Open No. 124739/1983).

Briefly, this device is applied to an engine mount, and a shaft member 2 made of gold pA# is disposed coaxially within a metal outer cylinder 1. A side wall 3.4 made of an elastic body made of rubber is formed between the outer cylinder 1 and the shaft member 2 to seal the inside of the outer cylinder 1. This sealed space consists of three triangular liquid chambers 6 divided by three partition walls 5 that radially connect the shaft member 2 and the outer cylinder 1.
... is formed. Further, the liquid chambers 6 are formed radially from the axis of the shaft member 2 and are communicated with each other through three communication holes 7. Then, in the radial direction of the shaft member 2 (in the direction of the arrow in FIG.
is deformed, the volume of each liquid chamber 6 changes its phase, and the enclosed liquid flows through the communication holes 7, thereby damping vibrations.

Problems to be Solved by the Invention However, in the conventional liquid-filled anti-S device, each liquid chamber 6 is connected to the shaft member 2 through the partition wall 5.
￥Since they are only formed radially around the center, although the volume of the liquid chamber can be changed in the radial direction of the shaft member 2 by the flow of the sealed liquid as described above, the volume change in the axial direction is almost negligible. I can't get it. Therefore, there is a problem that the imaging of the outer cylinder 1 and the shaft member 2 in the axial direction cannot be sufficiently attenuated.

Means for Solving the Problems This invention involves inserting a metal outer cylinder 1-2 into an inner cylinder coaxial with the outer cylinder, and arranging an elastic body between the outer cylinders.
At least four liquid chambers are provided in the elastic body at symmetrical positions on the left and right sides of the inner cylinder at the axial center thereof, separated vertically in the axial direction via partition walls, and further on the outer circumferential wall of the inner cylinder, A first orifice and a second orifice are provided in each of the liquid chambers to communicate the liquid chambers located diagonally or vertically, and one of the upper and lower end walls of the elastic body defining each of the liquid chambers is provided. It is characterized in that it is formed so as to be compressively deformed in response to the load in the axial direction.

According to this invention having the above-mentioned structure, when a vibration load is applied in the axial direction of the Fell, for example, the upper end wall of the elastic body is compressively deformed downward, and the volume of each upper liquid chamber is reduced. The working fluid of @1. The two inflows move through each lower liquid chamber: the second orifice. This precaution, combined with the expansion spring action of the partition wall, lower end wall, etc., makes the vibration loss factor in the axial direction sufficiently large. In particular, by circulating and moving the working fluid between the liquid chambers located diagonally through each orifice, it is possible to effectively damp vibrations not only in the axial direction but also, for example, in the backward direction of the vehicle body. It is.

Example Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 3 show a first embodiment of the present invention, and this liquid-filled vibration isolator is applied to a member mount such as a cross member 1 for a rear suspension of a main body. An opening L1a is provided at both the upper and lower ends,
Metal outer cylinder with llb”k @11 inner C:, this outer cylinder 1
A metal inner cylinder 12 coaxial with the inner cylinder 1 is disposed, and a rubber elastic body 13 is interposed between the inner cylinder 12 and the outer cylinder 11.

As shown in FIG. 1 and FIG. It is provided.

To be more specific, each liquid chamber 14, 15, 16,
17 are separated into two upper and lower stages by central partition walls 18 and 18 along the direction of the axis X at symmetrical positions with respect to the axis X of the inner cylinder 12, each of which has a cross section. It has a fan shape. In addition, the first and third liquid chambers 14°16
The upper end walls 19, 19 defining the respective upper parts of the outer cylinder 11 are formed diagonally upward in an outer shape with a certain angle f, and the outer ends thereof are bent in a circle at a part of the upper corner of the outer cylinder 11 CI r C3. It is fixed via annular first holding pieces 20, 20. On the other hand, the lower end walls 21 and 21 defining the lower portions of the second and fourth liquid chambers 15 and 17, respectively, are formed diagonally downward at a certain angle in an outer shape, and their outer ends are connected to the outer cylinder 11. A second annular holding piece 2 is bent at the lower corner portions C2 and C4.
2 and 22. The upper and lower end walls 19 , 19 , 21 , and 21 are configured such that when a load is applied in the direction of the axis X of the inner cylinder 12, when one of the upper and lower end walls is compressively deformed, the other is shearly deformed. It is formed. Further, each of the liquid chambers 14 and 15 described above.

As shown in FIGS. 2 and 3, the elastic body 13 other than the portions where 16 and 17 are formed has a C2 outer @ portion through a third holding piece 23 that is continuous with the above @1 and @2 holding pieces 20 and 22. Outer cylinder 1
A space 1124.25 is formed at the upper and lower ends of the elastic body 13 and has a triangular cross section to allow horizontal deformation of the elastic body 13.
Two circular arc holes 26°n for absorbing deformation are formed vertically in the circumferential direction C.

Furthermore, a first liquid chamber 14 and a fourth liquid chamber 1 located diagonally
7, as well as the @2 liquid chamber 15 and the third liquid chamber 16, each of which is formed on the outer circumferential wall of the inner cylinder 12 and is located in the first part of the nine-circle annular passage wall.
．． @2 They communicate independently through orifices 29 and 30. That is, 1st. 2nd orifice 29°30mm,
As shown in Fig. 4, they are approximately arc-shaped, with a total length of approximately 40 m and an inner diameter of 5 mm. Openings 29a and 29b are formed at both ends of the second orifice 30, and openings 30a and 30b are formed at both ends of the second liquid chamber 15 and third liquid chamber 16, respectively.

In FIG. 1, reference numeral 31 indicates an arcuate groove that allows elastic deformation of the upper end walls 19, 19, and reference numeral 32 indicates a slightly larger arcuate groove that allows elastic deformation of the lower end walls 21, 21.

Hereinafter, the effect of this embodiment will be explained based on FIG. At the same time, the partition wall 18°18 and the lower end wall 2
1 and 21 are sheared downward. Therefore, the first
Since the volumes of the liquid chamber 14 and the third liquid chamber 17 are reduced, the working fluid (for example, water) is transferred to the first liquid chamber 14 and the third liquid chamber 17. Second orifice 29, 30
The liquid flows into the second liquid chamber 15 and the fourth liquid chamber 17 through the liquid chamber 15 and the fourth liquid chamber 17, respectively. Therefore, the working fluid circulation effect and the partition wall 18
, 18 and the lower end walls 21, 21, etc., the loss factor increases as shown by the solid line in the wJs diagram, and the dovetail spring constant is suppressed to a small value. That is, it is clear that the peak frequency of the loss factor (solid line I) is tuned to about 80 Hz, and the magnitude in that vicinity reaches about i,oo. In addition, the dynamic spring constant (Kd) (solid line ■) draws a descending curve from 2FKV to 17Kf/w+ from 0 to around 70Hz,
It is clear that it increases from 70 Hz to around 140 Hz, but becomes a gentle downward curve at frequencies above that and is suppressed to a sufficiently low level.

Further, the working fluid is supplied to each liquid chamber 14°15 in the diagonal direction.
, 16, and 17, the axial deflection increases the loss factor for vibrations in the longitudinal direction of the vehicle body, making it possible to effectively damp vibrations.

Figure @6 shows a second embodiment of the present invention. In this embodiment, the first liquid chamber 14 and the second liquid chamber 15 in the axial direction, as well as the third
The liquid chamber 16 and the fourth liquid chamber 17'? 0: No. 0: Formed so as to communicate independently by the second oriices 49 and 50. That is, the psychic passage wall 4 provided on the outer peripheral wall of the inner cylinder 12
8, a first orifice 49 and a second orifice are formed in two stages, upper and lower, and both orifices 49, 5
0 has an annular shape as shown in FIG. 7, and each has a total length of about 15 m+* and an inner diameter of 5-mm. The first orifice 49 has an opening 49a in the first liquid chamber 14 at one end and an opening 49a in the second liquid chamber 15 at the other end.

49 b, while the second orifice 50 has an opening 501 at one end in the @3 liquid chamber 16 and an opening 501 in the fourth liquid chamber 17 at the other end.
L.

5Qb is formed.

Therefore, in this embodiment, the outer cylinder 1 as shown in FIG.
When vibration is applied to 1 in the axial direction, the upper end walls 19 and 19 are compressively deformed as shown in the figure, and the 1st and 3rd liquid chambers 1
No. 2.1, in which the working fluids in 4 and 16 are located directly below, respectively.
3!4 It flows into the liquid chambers 15 and 17. Therefore, as shown by the chain line in FIG. 8, the loss factor (dashed line 1) has a peak frequency of about 80 Hz (2), as described above, and its magnitude reaches about 0.75, and ?,ll!l
Although the spring constant (Kd) (dashed line ■) is not smaller than that in the first embodiment, it is clear that it is sufficiently suppressed.

Figure @9 shows the dynamic spring constant (Kd
) is tuned to the high frequency range of 120 Hz and 170 Hz, and the dynamic spring constant (
The comparison shows the characteristics when tuned to a suppression value g of 150 Hz. As is clear from this figure, in the case of the first embodiment, the frequency range is 50 Hz to 12 Hz.
Dynamic spring constant up to 011z is 40 9/III~2
3 Kg/1ml=, which can be suppressed more fully than before, and even from around 170Hz to about 36011zi, it can be suppressed more fully than before (shaded area)
.

Figure @10 shows the characteristics of the loss factor and dynamic spring constant obtained by changing the inner diameter l of the sixteenth second orifices 49 and 50 in the second embodiment,
The dashed line in the figure is for the case where the inner diameters of both orifices 49 and 50 are both set to 5φ as described above, and the solid line is for the case where the first orifice 49 is set to 5φ and the K2m orifice 5o is set to 15-. be.

In other words, the loss factor is about 80 Hz, which is the peak frequency, and about 200 Hz in the solid line I, compared to the dashed line I (@2 English flow side).
The values are connected by a gentle chevron curve up to around 80 Hz, and are approximately 0 at around 80 Hz and 0.6 at around 75.200 Hz. Therefore, it is clear that vibrations in the axial direction are sufficiently damped over a wide frequency range.

On the other hand, regarding the dynamic spring constant (Kd), the chain line [(second
In comparison with Example), in the solid line ■, the frequency Oflz ~ about 20
It is clear that frequencies down to 0 Hz are sufficiently suppressed (shaded area).

In addition, the first in each of the above embodiments. By changing not only the inner diameter of the second orifice but also the thickness of the upper and lower end walls 19, 19, 21, 21 or the inclination angle l, the peak frequency of the loss factor and the suppression value l of the dynamic spring constant can be changed. 〇, it is also possible to obtain a large vibration damping effect.

Effects of the Invention As is clear from the above explanation, the liquid-filled vibration isolator according to the present invention can sufficiently suppress unit vibration over a wide frequency range, and in particular, each liquid chamber is connected to the first orifice and @ Since the two orifices are configured to communicate in the diagonal direction and in the axial direction of the inner cylinder, vibrations in the axial direction can be effectively damped.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the first embodiment of the liquid-filled vibration isolator according to the present invention, Fig. @2 is a cross-sectional view taken along the line ■-■ of Fig. @1, and Fig.
The figure is a vertical sectional view of FIG. 1, FIG. 4 is a plan sectional view showing the first and second orifices used in this embodiment, and FIG. 5 is an explanatory diagram showing the operating state of this embodiment. FIG. 6 is a sectional view showing @2 embodiment 1 of the present invention, FIG. 7 is a plan sectional view showing the first and second orifices used in this embodiment, and FIG. A characteristic diagram showing the loss factor and spring l according to the embodiment, FIG. 9 is a characteristic diagram showing the dynamic spring characteristics of the first embodiment in a high frequency range in comparison with a conventional one, and FIG. 10 is a characteristic diagram showing 25i1! Example 1. Inner diameter of g2 orifice! In case of change: A characteristic diagram showing the loss factor and dynamic spring in comparison with that of the second embodiment, Fig. 11 is a vertical cross-sectional view of the conventional device, and Fig. 12 is the graph of ■-■ in Fig. 11. FIG. 11... Outer cylinder, 12... Inner cylinder, 13... Elastic body,
14...@1 liquid chamber, 15...2nd liquid chamber, 16...
3rd liquid chamber, 17... 4th liquid chamber, 18... partition wall, 19
...Top end wall, 21...Lower end wall, 29, 49...
1st orifice, 30, 50...2nd orifice. 2 people Fig. 4 Fig. 5 1 Fig. 6 Fig. 7

Claims (1)

[Claims] (1) An inner cylinder coaxial with the outer cylinder is inserted into a metal outer cylinder, and an elastic body is arranged between the inner and outer cylinders, and the axis of the inner cylinder within the elastic body is approximately In a symmetrical position,
At least four liquid chambers are provided which are vertically separated in the axial direction via partition walls, and further, liquid chambers are provided on the outer circumferential wall of the inner cylinder, and liquid chambers are arranged diagonally or vertically in each of the liquid chambers. A first orifice and a second orifice are provided to communicate with each other, and either one of the upper and lower end walls of the elastic body defining each of the liquid chambers is formed to be compressively deformed in response to the load in the axial direction. Features a liquid-filled vibration isolator.