JPS61157849A - Vibration preventing device - Google Patents

Abstract

PURPOSE:To reduce change in characteristics due to temperature by forming a pair of air chambers communicating to the atmosphere through an orifice between inside and outside members to provide a vibration preventing action through air entering and exiting said chambers. CONSTITUTION:A cylindrical hollow elastic body 16 is disposed inside an outer ring 10, and an inner ring 12 extends through the axial portions of the top and bottom plates 16A, 16B of the hollow elastic body 16. The hollow elastic body 16 is formed in the interior with a hollow chamber which is defined by a partition wall 20 extending radially of the inner ring 12 to provide a pair of air chambers 22, 24. The air chambers 22, 24 communicate to the atmosphere through orifices 26 extending through the outer ring 10 respectively. Since the air chambers 22, 24 thus communicate to the atmosphere, change in characteristics due to temperature difference can be restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration isolating device that is interposed between a vibration generating section and a vibration receiving section and absorbs vibrations from a vibration source.

[Background technology and matters to be solved]

In a vibration isolating device used for automobile engine parts, etc., the hollow part of the vibration absorbing body is used as a liquid chamber, and this liquid chamber is divided into a plurality of small liquid chambers by partition members, and the vibration is A configuration has been proposed in which the small liquid chambers are communicated with each other. In this vibration isolator, when vibration occurs, the vibration is attenuated by the internal friction of the vibration absorbing body and the resistance force when liquid passes through the restriction passage.

However, in such a vibration isolating device, sealing the liquid inside the liquid chamber is complicated and causes an increase in cost. If a gas such as air is used instead of this liquid, there is no need for the complexity of liquid sealing, but there is less loss compared to liquid when air passes through an orifice, and the characteristics are affected by temperature differences. is easy to change.

In consideration of the above facts, the present invention aims to provide a vibration isolating device that uses gas as the fluid to facilitate manufacturing, has less change in characteristics due to temperature differences, and can increase loss when passing through an orifice. .

[Summary and operation of the invention]

In the vibration isolator according to the present invention, at least one pair of air chambers each having a partition wall provided with an elastic material is provided between an outer member connected to one of the vibration generating section and the vibration receiving section and an inner member connected to the other. are provided, and these air chambers are arranged on opposite sides via the inner member and each communicates with the outside via an orifice.

Therefore, in the present invention, even when a temperature difference occurs, the air in the air chamber moves to the outside through the orifice, thereby suppressing changes in characteristics due to temperature difference, and by providing the partition with an elastic material, the spring constant is reduced. It is now possible to increase losses by doing so.

[Embodiments of the invention]

FIG. 1.2 shows a vibration isolator in which a first embodiment of the present invention is applied as an engine mount. In the vibration isolator of this embodiment, an inner ring 12 is disposed coaxially with an outer ring 10 to constitute an outer member and an inner member, respectively.

An intermediate ring 14 is press-fitted inside the outer ring 10, and a hollow elastic body 16 is inserted into the inside of this intermediate ring 14.
is located. This hollow elastic body 16 has a cylindrical shape, and its outer periphery is vulcanized and bonded to the inside of the intermediate ring 14, and the inner ring 12 passes through the top plate 16A and the bottom plate 16B at their axes, and is vulcanized and bonded to the inside of the intermediate ring 14.

Therefore, the inside of the hollow elastic body 16 forms a hollow chamber,
This hollow chamber is partitioned by a partition wall 20 interposed between the inner ring 12 and the intermediate ring 14 and extending in the radial direction of the inner ring 12, forming a pair of air chambers 22 and 24.

In addition, the air chambers 22 and 24 are the outer ring 10,
An orifice 26 extending through the intermediate ring 14 communicates with the atmosphere.

In the vibration isolating device of this embodiment configured as described above, assembly is completed by mounting one of the outer ring 101 and inner ring 12 on the vehicle body and the other on the automobile engine.

In Fig. 1, the inner ring 12 is the outer ring 1.
When moving upward relative to 0, the air chamber 22 is compressed and the air inside is discharged to the atmosphere through the orifice 26, and the air chamber 24 is expanded and air flows in from the atmosphere through the orifice 26. . Therefore, attenuation occurs due to losses when air passes through the orifice 26. Top plate 16A
, since the bottom plate 16B has a thin structure, the spring constant is low;
The loss factor can be increased. In particular, large losses can be caused at specific frequencies, and the dynamic spring constant at high-frequency minute amplitudes where no air enters or exits at the orifice is not made much larger than the static spring constant, causing muffled noise. Less is.

Also, due to the temperature difference, the air in the air chambers 22 and 24 expands,
Even when contracted, these air can flow in and out from the outside through the orifice 26, so changes in characteristics due to temperature differences are suppressed. Furthermore, the degree of airtightness of the air chambers 22, 24 is easier to control and easier to manufacture than when a liquid is sealed inside.

Next, FIGS. 3 and 4 show a vibration isolating device according to a second embodiment of the present invention.

In this embodiment, one end of the flexible tube 28 communicates with the atmosphere side of the orifice 26 in the previous embodiment.
The other end of 8 is open to the atmosphere.

Next, FIG. 5(A) is an exploded view showing a third embodiment of the present invention. In this embodiment, the outer ring 10 is not provided with a hole constituting the orifice 26, and the intermediate ring 1
4 is formed with a bottomed groove 32 that constitutes an orifice. When the hollow elastic body 16 is vulcanized and molded to the inner periphery of the intermediate ring 14, an opening 33 that communicates the air chamber 22 (24) with the outside is passed through, and the bottomed groove 32 meets the inner edge of this opening 33. It is in a state where it is connected to the end face of the intermediate ring 14. Moreover, when this opening 33 is press-fitted into the outer ring 10, it is closed by the inner peripheral surface of the outer ring 10, and the bottomed groove 32
It will be communicated with the outside only through.

Therefore, in this embodiment, the air chamber is communicated with the atmosphere via the bottomed groove 32, and the bottomed groove 32 forms an orifice. This orifice has a bottomed groove 32 as shown in Fig. 5(B).
The axial length may be extended by bending or the like. In addition,
This bottomed groove may be formed on the inner wall of the outer ring 10.

Further, FIG. 6 shows a fourth embodiment of the present invention, in which an opening 33 for forming a hollow chamber is formed in the intermediate ring 14.
An example will be shown in which a hole 36 is made in the outer ring 10 and used as an orifice after the intermediate ring I4 is press-fitted, without providing a bottomed groove.

Alternatively, the orifice may be lengthened by providing a bottomed groove on the inner periphery of the intermediate ring.

Next, FIG. 7 shows a fifth embodiment of the present invention. In this embodiment, an air chamber 38 is provided in addition to the air chambers 22.24 of the first embodiment, and an adjacent air chamber 22.24 is provided.
A partition wall 20 is interposed between the inner ring 12 and the inner ring 12, so that three partition walls and air chambers are arranged at equal intervals around the axis of the inner ring 12.

In this embodiment, an outer ring 10 and an inner ring 1
It is possible to generate a high damping force no matter what direction 2 moves in the direction perpendicular to the plane of FIG. 7.

Next, FIG. 8.9 shows a vibration isolator according to a sixth embodiment of the present invention. In this embodiment, in the vibration isolating device in the first embodiment, the top plate 16A and the bottom plate 16B of the hollow elastic body 16 are connected to the inner ring 12 and the outer ring 1.
0 and are curved in the direction of approaching each other. As a result, when the outer ring 10 and the inner ring 12 move relative to each other in the vertical direction in FIG. 9, more air inside can be moved, and a large damping force can be obtained.

Next, FIGS. 12 and 13 show a seventh embodiment of the present invention. In this embodiment, a stopper 40 protrudes outward from a part of the partition wall 20, that is, in a direction that reduces the volume of the air chamber 22.24, and when the outer ring 10 and the inner ring 12 move relative to each other by more than a predetermined amount, The stopper 40 comes into contact with the intermediate ring 14 to limit the amount of movement. This improves the durability of the vibration isolator.

In the eighth embodiment shown in FIGS. 14 and 15, unlike the previous embodiments, a foam body 42 is provided in a part of the partition wall 20,
It protrudes outward, ie in the direction of volume reduction of the air chambers 22,24. Therefore, in this embodiment the air chambers 22.24
The air volume of the foam 42 can be reduced, resulting in a large loss, and even when the outer ring 10 and the inner ring 12 undergo a large relative displacement and the foam 42 is compressed, there is no large reaction force.

Next, FIGS. 16 to 18 show a ninth embodiment of the present invention. In this embodiment, the hollow elastic body 16 has a substantially U-shaped cross section as shown in FIG. The radial ends of this hollow elastic body 16 are brought into contact with the inner circumference of the outer ring 10, and both axial ends of the outer ring 10 wrap around the ring 44 and the radial ends of the hollow elastic body 16 and are caulked. As a result, an air chamber is formed between the outer ring 10 and the U-shaped recess of the hollow elastic body 16. This embodiment is similar to the previous embodiments in that the air chambers 22, 24 are communicated with the outside through orifices.

In this way, in this embodiment, when molding the hollow elastic body 16, the core interposed in the portion corresponding to the air chamber is made into a split type, and the split core is removed in the radial direction of the inch ring 12. This makes it possible to easily form a U-shaped recess for forming an air chamber.

FIG. 19 shows an intermediate ring 14 as a modification of FIG. 18.
is omitted, and a configuration is shown in which the hollow chamber forming partition wall 20 of the elastic body is directly vulcanized and bonded to the outer ring 10.

〔Effect of the invention〕

As explained above, in the vibration isolator according to the present invention, an air chamber is provided between the outer member and the inner member, and this air chamber has an elastic material on the partition wall and communicates with the outside via the orifice. It has the excellent effect of being simple, suppressing changes in characteristics due to temperature differences, and obtaining large damping characteristics.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing a first embodiment of a vibration isolator according to the present invention, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a plan view showing a second embodiment of the present invention. , FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3, FIGS. 7 is a plan view showing the fifth embodiment of the present invention, FIG. 8 is a plan view showing the sixth embodiment of the present invention, and FIG. 9 is a plan view showing the eighth embodiment of the present invention. Cross-sectional view taken along the line IX-IX in the figure, No. 10
The figures are FIG. 8 (71X-X NIA sectional view, FIG. 11 is a sectional view taken along the line XI-XI of FIG. 8<7), FIG. xm- in Figure 12
14 is a plan view showing the eighth embodiment of the present invention; FIG. 15 is a sectional view taken along line xv-xv of FIG. 14;
6 is a plan view showing the ninth embodiment of the present invention, FIG. 17 is a sectional view taken along the line X--X in FIG. 16, and FIG. 18 is a sectional view taken along the line X--X in FIG. 16. FIG. 19 is a sectional view showing a modification of FIG. 18. 10... Outer ring, 12... Inner ring, 22.24... Air chamber, 26... Orifice, 38... Air chamber.

Claims (1)

[Claims] (1) At least a pair of air chambers equipped with an elastic material are provided in the picture wall between the outer member connected to one of the vibration generating section and the vibration receiving section and the inner member connected to the other, and these air chambers are provided with an elastic material. A vibration isolating device characterized in that the chambers are arranged on opposite sides via an inner member, and each of these air chambers is communicated with the outside via an orifice.