JPH0526288A - Resilient buffering device - Google Patents

Abstract

PURPOSE:To increase the range of a vibration frequency capable of being damped, CONSTITUTION:A fluid chamber 6 formed between inner and outer cylinders 2 and 3 is partitioned into a fluid chamber 6a on the upper side and a fluid chamber 6b on the lower side, and the fluid chambers 6a and 6b are intercommunicated through a helical orifice 7b to form a low frequency vibration damping member 7. Meanwhile, an umbrella-form high frequency damping member 8 moved within the fluid chamber 6 along with movement of the inner cylinder 2 is disposed in the fluid chamber 6. This constitution performs damping of vibration of a frequency covering a wide range by means of a single device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic shock absorber,
In particular, the present invention relates to a fluid-filled type shock absorber in which a fluid chamber is formed inside an elastic body.

[0002]

2. Description of the Related Art Conventionally, as an example of an elastic shock absorber used for an upper support, a cab mount, a body mount, an engine mount of a vehicle suspension, a fluid chamber is formed inside an elastic body, and the fluid chamber is formed in the fluid chamber. A structure in which a fluid such as oil is enclosed is known. This type of elastic shock absorber is disclosed in, for example, Japanese Utility Model Laid-Open No. 12547/1990, in which the shaft of each cylinder is provided between an inner cylinder and an outer cylinder that relatively move (vibrate) by an external load. A pair of elastic bodies are installed at intervals in the direction to form a fluid chamber in which a fluid is enclosed between the elastic bodies, and the fluid chamber is divided into a plurality of small fluid chambers and each small fluid is formed. It is known that the chambers are made to communicate with each other by an orifice. As a result, when vibration is generated between the inner cylinder and the outer cylinder due to an external load, this vibration is caused by the elastic force of each elastic body and the flow resistance of the fluid in the orifice due to the change in volume of each small fluid chamber. Is to be attenuated.

[0003]

However, in the elastic shock absorber constructed in this way, it seems that the elastic shock absorber is arranged in a place where the vibration frequency range that can be damped is narrow and vibrations of various frequencies occur. In such a case, there is a problem that vibration cannot be damped for vibration of a certain frequency.
In particular, since the frequency range of the vibrations generated in each of the vibration generating parts of the automobile as described above extends over a wide range, in the conventional structure, all the vibrations of the frequencies over the wide range are attenuated by one elastic damping device. It was impossible to make them.

The present invention has been made in view of this point, and an object thereof is to obtain an elastic shock absorber capable of widening a wide range of vibration frequencies that can be damped.

[0005]

In order to achieve the above object, the present invention has a means for attenuating low frequency vibrations and a means for attenuating high frequency vibrations in a fluid chamber. Specifically, the invention according to claim 1 is provided with an elastic body laid across an inner cylinder to which one of the vibration generating portion and the vibration receiving portion is attached and an outer cylinder to which the other is attached, and the elastic body is provided in the elastic body. On the other hand, a flexible elastic film is provided at a position spaced apart by a predetermined distance in the axial direction of the inner cylinder and the outer cylinder, and between the inner cylinder and the outer cylinder by the elastic body and the flexible elastic body. , An elastic shock absorber in which a fluid chamber in which a fluid is sealed is formed. Then, in the fluid chamber,
At least two fluid chambers are divided into small fluid chambers, and a low frequency vibration damping member having a spiral orifice for communicating the respective small fluid chambers, and an external load applied to the inner cylinder or the outer cylinder. An umbrella-shaped high-frequency vibration damping member that moves in the fluid chamber with relative movement is arranged.

According to a second aspect of the present invention, in the elastic damping device according to the first aspect, the high frequency vibration damping member is elastically supported by an elastic body.

According to a third aspect of the present invention, in the elastic damping device according to the first or second aspect, when the high frequency vibration damping member is moved between the high frequency vibration damping member and the low frequency vibration damping member, The configuration is such that an interference suppression member that suppresses interference between the two is provided.

[0008]

With the above-described structure, the present invention has the following effects. In the invention according to claim 1, when low-frequency vibration occurs between the inner cylinder and the outer cylinder, the low-frequency vibration is attenuated by flowing the fluid between the small fluid chambers through the spiral orifice. . On the other hand, when a high frequency vibration is generated, the high frequency vibration damping member moves in the fluid chamber to damp the high frequency vibration. In this way, vibration can be damped over a wide range of low frequencies and high frequencies with one device.

According to the second aspect of the invention, when the lower end edge of the high frequency vibration damping member interferes with the outer cylinder in a situation where the inner cylinder is twisted by an external load, the high frequency vibration damping member is elastic. Since the high-frequency vibration damping member is elastically supported by the body, the outer cylinder and the high-frequency vibration damping member are prevented from being damaged by strong pressure on the outer cylinder, and vibration and prying occur at the same time. Even in this case, the vibration can be efficiently damped.

According to the third aspect of the present invention, when a large load acts on the inner cylinder and the displacement of the inner cylinder increases, the interference suppressing member causes the high-frequency vibration damping member and the low-frequency vibration damping member to come into contact with each other. Is prevented and damage to both is avoided.

[0011]

【Example】

(First Embodiment) Next, a first embodiment of the present invention will be described with reference to FIG.
And it demonstrates based on FIG. FIG. 1 shows a vertical cross-sectional view of an elastic shock absorber 1 according to this example. This elastic shock absorber 1 is arranged at the upper end of a strut of a front suspension of an automobile (not shown), and is arranged for the purpose of damping vibrations due to the unevenness of the road surface input to the vehicle body through the tires.

The elastic shock absorber 1 is provided between the inner cylinder 2 as the upper end of the strut and the outer cylinder 3 for pivotally supporting the upper end of the strut.
On the other hand, it works so as to damp the vibration of the inner cylinder 2 which moves in the vertical direction. The inner cylinder 2 is made of a small-diameter tubular member, and the lower part thereof is connected to a shock absorber of a suspension (not shown). On the other hand, the outer cylinder 3 is formed to have a diameter larger than that of the inner cylinder 2, and a straight pipe portion 3a is formed at a substantially central portion in the vertical direction thereof.
On the upper side of "a", the diameter gradually increases toward the top.
A taper portion 3b is formed, and a flange portion 3c extending horizontally is formed at the upper end of the taper portion 3b.
The flange portion 3c is fastened by bolts B, B to a sustainer upper as a vehicle body side member (not shown). On the other hand, on the lower side of the straight pipe portion 3a, a locking portion 3d having a substantially U-shaped vertical section is formed.

The structure of the elastic shock absorber 1 will be described in detail below. This elastic shock absorber 1 has an elastic body 4 on its upper part.
Is equipped with. The inner peripheral surface 4a of the elastic body 4 is fixed to the outer peripheral surface 2a of the inner cylinder 2, and the outer peripheral surface 4b thereof is fixed to the inner peripheral surface 3e of the outer cylinder 3 by vulcanization adhesion. Also,
The elastic body 4 is formed in such a shape that each of the inner peripheral surface 4a and the outer peripheral surface 4b is extended downward in order to secure a sufficient bonding surface with each of the cylinders 2 and 3. Inner surface 4
The lower portion of a is a thick-walled tubular elastic portion 4c.

On the other hand, a flexible elastic film 5 is provided below the elastic shock absorber 1 at a position spaced apart from the elastic body 4 by a predetermined distance. An inner peripheral surface 5 a of the flexible elastic film 5 is locked to the outer peripheral surface 2 a of the inner cylinder 2, and an outer peripheral portion 5 b is locked to the locking portion 3 d of the outer cylinder 3.

In this way, since the elastic body 4 and the flexible elastic film 5 are provided between the inner cylinder 2 and the outer cylinder 3, respectively, the inner cylinder 2 and the outer cylinder 3 are formed by the both members 4 and 5. A fluid chamber 6 which is a closed space is formed between the fluid chamber 3 and the fluid chamber 3. Then, oil O as an incompressible fluid is placed in the fluid chamber 6.
Is enclosed.

As a characteristic configuration of this example,
The low frequency vibration damping member 7 and the high frequency vibration damping member 8 are disposed in the fluid chamber 6. Low frequency vibration damping member 7
Is composed of a flexible film 7a and a spiral orifice 7b. The outer peripheral portion 7c of the flexible film 7a is overlapped with the upper surface of the outer peripheral portion 5b of the flexible elastic film 5 and is locked to the locking portion 3d of the outer cylinder 3. On the other hand, the inner peripheral portion 7d of the flexible film 7a is fixed to the outer peripheral portion of the spiral orifice 7b. With such a configuration, the fluid chamber 6 is divided into the small fluid chamber according to the present invention, and the upper fluid chamber 6a formed above the flexible membrane 7a and the spiral orifice 7b.
And a lower fluid chamber 6b formed on the lower side.

The spiral orifice 7b is formed into a ring shape by combining two plate members 7e and 7f having a substantially L-shaped cross section, and a fluid passage 7g is formed inside thereof.
The fluid passage 7g has spiral orifices formed by a combination of the plate members 7e and 7f, and has openings (not shown) formed at the upper and lower end positions thereof. As a result, the chambers 6a and 6b are
The fluid chambers 6 are communicated with each other only by the fluid passages 7g.
The oils O in a and 6b are allowed to flow mutually. Therefore, when a vertical load is applied to the inner cylinder 2,
The volumes of the upper and lower fluid chambers 6a and 6b change with the deformation of the elastic body 4 and the flexible elastic film 5, and accordingly, the oil O in the fluid chambers 6a and 6b changes the fluid passage 7g of the spiral orifice 7b. Circulate inside. Then, due to the flow resistance during the distribution, the vibration generated by the load is damped. Further, the vibration frequency range that can be damped by the low frequency vibration damping member 7 is a relatively low frequency range.

The high frequency vibration attenuating member 8 is a so-called high frequency device and is disposed above the low frequency vibration attenuating member 7, and as shown in FIG. 2, the cylindrical elastic portion 4c of the elastic body 4 is formed. The cylindrical portion 8a is fitted in and the umbrella-shaped portion 8b is continuously formed below the cylindrical portion 8a. The umbrella upper portion 8b is formed continuously with the lower portion of the cylindrical portion 8a, and has an inverted bowl shape in which the opening diameter gradually increases from the lower end of the cylindrical portion 8a toward the lower side. Further, the outer peripheral edge portion of the lower end portion of the umbrella-shaped portion 8b is set at a position where there is a small gap S with the inner peripheral surface 3e of the outer cylinder 3. As a result, the upper fluid chamber 6a is divided into an upper region 6c and a lower region 6d by the umbrella-shaped portion 8b. Therefore, when a vertical load is applied to the inner cylinder 2, the high frequency vibration damping member 8 moves up and down in the upper fluid chamber 6a as the elastic body 4 deforms, and is generated by the load. It is designed to damp vibrations. Further, the vibration frequency range that can be damped by the high frequency vibration damping member 8 is a relatively high frequency range. Further, here, the flexible film 7a and the flexible elastic film 5 are formed of a diaphragm containing a reinforcing woven fabric layer,
It is designed not to burst easily under fluid pressure.

Reference numeral 9 in FIG. 1 is a cover for protecting the flexible elastic film 5.

Next, the vibration damping operation of the elastic damping device 1 configured as described above will be described. First, in a situation where a vertical low-frequency vibration is generated in the inner cylinder 2 due to an external load, the elastic body 4 and the flexible elastic film 5 are deformed by the vertical movement of the inner cylinder 2, and Each fluid chamber 6
The volumes of a and 6b change. The oil O in each of the fluid chambers 6a and 6b flows through the fluid passage 7g of the spiral orifice 7b in accordance with the change in the volume. The low-frequency vibration is damped by the flow resistance of the spiral orifice 7b during the circulation.

On the other hand, in a situation where a high frequency vibration in the vertical direction is generated in the inner cylinder 2 due to an external load, the elastic body 4 is deformed by the vertical movement of the inner cylinder 2,
The high frequency vibration damping member 8 moves up and down in the upper fluid chamber 6a. At this time, the oil O in the upper fluid chamber 6a is mutually flowed while passing through the small gap S between the upper region 6c and the lower region 6d, whereby the high frequency vibration is attenuated, The transmission rate of vibration is reduced.

Further, in a situation where the inner cylinder 2 is twisted by an external load, the lower end edge of the high frequency vibration damping member 8 may interfere with the inner peripheral surface 3e of the outer cylinder 3. is there. When such interference occurs, the cylindrical portion 8a of the high-frequency vibration damping member 8 is elastically supported by the cylindrical elastic portion 4c of the elastic body 4, and therefore, in this interference state, the cylindrical portion 8a with respect to the axis of the inner cylinder 2 High frequency vibration damping member 8
Since the center line of the high frequency vibration damping member 8 can be tilted, the lower end edge of the high frequency vibration damping member 8 is not strongly pressed against the inner peripheral surface 3e of the outer cylinder 3 and damages the outer cylinder 3 and the high frequency vibration damping member 8. Not only is it avoided that the inner cylinder 2 can move up and down even in this interference state, so that even if vibration and prying occur at the same time, the vibration can be efficiently generated. Can be dampened.

As described above, in the elastic damping device 1 of the present embodiment, both the low frequency vibration and the high frequency vibration can be damped, so that the vibration frequency region in which the vibration can be damped can be widely secured, and the vibration frequency range of various frequencies can be secured. It can be arranged at a place where vibration is generated, and in particular, when it is arranged at the upper end portion of the strut of the front suspension of the automobile as in this example, the practicality can be largely secured. Furthermore, even when the inner cylinder 2 is twisted, damage to each member can be prevented, and when vibration and prying are simultaneously generated,
It is possible to achieve both prevention of damage to each member and damping of vibration.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. Further, since the basic structure of the elastic shock absorber 1 of this example is substantially the same as that of the above-described first example, detailed description thereof will be omitted, and only the configuration of a particularly characteristic part will be described.

One of the characteristic features of the elastic damping device 1 of this example is the configuration of the low frequency vibration damping member 7. In this low frequency vibration damping member 7, a spiral orifice 7b is fixed to an inner peripheral surface 3e of the outer cylinder 3, and a flexible film 7a is formed between the inner peripheral portion of the spiral orifice 7b and the outer peripheral surface 2a of the inner cylinder 2. It has been installed over. When low-frequency vibration is generated, the low-frequency vibration is damped by the flow resistance of the spiral orifice 7b as in the operation of the first embodiment described above.

Another feature of the present embodiment is the high frequency vibration damping member 8. The high frequency vibration damping member 8 has the cylindrical portion 8a fitted to the inner cylinder 2, and does not have the elastic support structure as shown in the first embodiment. A protective elastic body 10 made of rubber or the like is arranged at the lower end edge of the umbrella-shaped portion 8b of the high frequency vibration damping member 8 so as to cover the lower end edge. Therefore, when the high frequency vibration is generated, the high frequency vibration damping member 8 attenuates the high frequency vibration by the same operation as the operation of the first embodiment described above, and the transmission rate of the vibration. Is reduced. Further, in a situation where the inner cylinder 2 is twisted due to an external load, the lower end edge of the high frequency vibration damping member 8 contacts through the protective elastic body 10, so that the outer cylinder 3 and The high frequency vibration damping member 8 can be prevented from being damaged.

(Third Embodiment) Next, a third embodiment according to the present invention will be described with reference to FIG. Further, even in the present example, only the configuration of a particularly characteristic part will be described.

The elastic damping device 1 of the present embodiment is characterized by the ring member 11 as the interference suppressing member in the present invention, which is disposed between the low frequency vibration damping member 7 and the high frequency vibration damping member 8. The ring member 11 includes a lower end portion of the high frequency vibration damping member 8 and a flexible film 7 a of the low frequency vibration damping member 7.
A metal plate-shaped member having an L-shaped cross-section disposed between the outer peripheral portion and the inner peripheral surface 3e of the outer cylinder 3 and having an L-shaped inner portion and an upper portion. It is covered with a thin rubber layer over the inner space.

With this structure, the ring member 1
The thin rubber layer of No. 1 prevents abnormal noise due to interference between the low-frequency vibration damping member 7 and the high-frequency vibration damping member 8, and a large load acts on the inner cylinder 2 to displace the inner cylinder 2 downward. In the case of a large value, the lower edge portion of the high frequency vibration damping member 8 is prevented from coming into contact with the flexible film 7a and damaging the flexible film 7a. At the same time, the ring member 11 itself functions as a large-diameter orifice in addition to the function as the interference suppressing member, and can reduce the vibration transmissibility in the combined high frequency vibration region together with the high frequency vibration damping member 8.

In each of the above-described embodiments, the case where the elastic shock absorber 1 of the present invention is arranged at the upper end of the strut of the front suspension of the automobile has been described, but the present invention is not limited to this, and the cab mount, Body mount,
It can be applied not only to each part of an automobile such as an engine mount, but also to various vibration generating parts other than the automobile. Further, in this example, the inner cylinder 2 is attached to the vibration generating part and the outer cylinder 3 is attached to the vibration receiving part. On the contrary, the outer cylinder 3 is attached to the vibration generating part and the inner cylinder 2 is attached to the vibration receiving part. You may make it employ | adopt to the location attached to a part.

[0031]

As described above, according to the present invention, the following effects are exhibited. According to the invention of claim 1, the low-frequency vibration damping member and the high-frequency vibration damping member are arranged in the fluid chamber, and when a low-frequency vibration occurs between the inner cylinder and the outer cylinder, the small fluid The low frequency vibration is damped by the fluid flowing between the chambers through the spiral orifice, while when the high frequency vibration is generated, the high frequency vibration damping member moves in the fluid chamber so that the high frequency vibration is absorbed. By attenuating the vibration of No. 1, it is possible to attenuate the vibration over a wide range of low frequencies and high frequencies with one device.

According to the second aspect of the present invention, since the high frequency vibration damping member is elastically supported by the elastic body, the lower end edge portion of the high frequency vibration damping member can be twisted in a situation where the inner cylinder is twisted by an external load. In the case where the high frequency vibration damping member interferes with the outer cylinder, the high frequency vibration damping member is not strongly pressed against the outer cylinder, damage to the outer cylinder and the high frequency vibration damping member is prevented, and vibration and prying occur simultaneously. Even in this case, the vibration can be efficiently damped.

According to the third aspect of the invention, since the interference suppressing member is provided between the high frequency vibration damping member and the low frequency vibration damping member, a large load acts on the inner cylinder, and the inner cylinder If the displacement of the high frequency vibration damping member becomes large, the interference suppressing member prevents contact between the high frequency vibration damping member and the low frequency vibration damping member and avoids damage to both, thus improving the reliability of the device. You can Further, since the interference suppressing member simultaneously acts as a large-diameter orifice, it is possible to reduce the transmissibility of vibration over a wide range of high frequency regions combined with the high frequency vibration damping member.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an elastic shock absorber according to a first embodiment.

FIG. 2 is a cross-sectional view at a position corresponding to line II-II in FIG.

FIG. 3 is a view corresponding to FIG. 1 in the second embodiment.

FIG. 4 is a view corresponding to FIG. 1 in a third embodiment.

[Explanation of symbols]

1 Elastic shock absorber 2 inner cylinder 3 outer cylinder 4 elastic body 5 Flexible elastic film 6 fluid chamber 6a Upper fluid chamber (small fluid chamber) 6b Lower fluid chamber (small fluid chamber) 7 Low frequency vibration damping member 7b spiral orifice 8 High frequency vibration damping member 11 Ring member (interference suppression member)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location F16F 13/00 K 9138-3J

Claims (3)

[Claims] 1. An elastic body is provided so as to span an inner cylinder to which one of the vibration generating portion and the vibration receiving portion is attached and an outer cylinder to which the other is attached, and the inner cylinder and the outer portion are provided with respect to the elastic body. A fluid that includes a flexible elastic film arranged at a predetermined distance in the axial direction of the cylinder, and the fluid is sealed between the inner cylinder and the outer cylinder by the elastic body and the flexible elastic body. A low frequency vibration damping member having a spiral orifice for partitioning at least two small fluid chambers into the fluid chamber and connecting the small fluid chambers to each other. And an umbrella-shaped high-frequency vibration damping member that moves in the fluid chamber with relative movement when an external load acts on the inner cylinder or the outer cylinder. 2. The elastic shock absorber according to claim 1,
The high-frequency vibration damping member is elastically supported by an elastic body. 3. The elastic damping device according to claim 1, wherein the high frequency vibration damping member and the low frequency vibration damping member are prevented from interfering with each other when the high frequency vibration damping member moves. An elastic shock absorber characterized in that an interference suppressing member is provided.