JPH09273586A - Vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly reduce the vibration of an arbitrary frequency from an engine such as noise in high engine speed. SOLUTION: An intermediate cylinder 14 is inserted inside an outer cylindrical metal piece 12. An elastic body 18 is vulcanizingly glued inside the intermediate cylinder 14 and an inner cylindrical metal piece 20 is disposed in the center of the elastic body 18. A main fluid chamber 30 and a sub fluid chamber 32 communicate with each other by restricting passages 34. A pair of separation parts 42A of an intermediate plate 42 is arranged in the elastic body 18 between the inner cylindrical metal piece 20 and the intermediate cylinder 14 to divide the elastic body 18 into two sections. Metal vibrating plates 44 are connected to the lower side of the intermediate plate 42 for preventing an excess displacement of the inner cylindrical metal piece 20. In this case, the vibrating plates 44 are positioned in the main fluid chamber 30 to form contracted parts 38 between those plates and the bulkhead of the main fluid chamber 30.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a general industrial machine,
The present invention relates to a vibration isolator used for an engine mount or the like of an automobile, and more particularly to a liquid filled type vibration isolator.

[0002]

2. Description of the Related Art Conventionally, there has been known an anti-vibration device provided as an engine mount between an engine of an automobile and a vehicle body. In recent years, a liquid-filled type vibration damping device having a high vibration damping effect has been proposed as a type of this vibration damping device, and an example thereof will be described below with reference to FIG.

As shown in FIG. 4, an elastic body 106, which is a main body rubber, is bridged between an inner cylinder 102 and an intermediate cylinder 104 of the liquid-filled type vibration damping device 100, so that the inner cylinder 102 and the intermediate cylinder 104. It is vulcanized and adhered to 104. The intermediate cylinder 104 is press-fitted inside the outer cylinder 118.

A recess 108 is formed in the elastic body 106, and a main liquid chamber 110 is formed between the recess 108 and the outer cylinder 118. The main liquid chamber 110 is communicated with a sub liquid chamber 114 on the opposite side of the inner cylinder 102 via a restriction passage 112, and the sub liquid chamber 114 is deformed according to the pressure change of the main liquid chamber 110. The diaphragm 116 which faces is facing.
A stopper portion 120 connected to the inner cylinder 102 is arranged in the main liquid chamber 110.

Here, when vibration is input to the vibration isolator 100 and the inner cylinder 102 and the intermediate cylinder 104 are relatively displaced in the radial direction (the vertical direction in the figure), the main liquid chamber 110 expands and contracts, and the main liquid chamber 110. The diaphragm 116 of the sub liquid chamber 114 is elastically deformed due to the pressure change, and the liquid flows back and forth in the restriction passage 112 to generate a damping force. Further, at this time, the stopper portion 12
Flange 120A and main liquid chamber 1 forming the front end portion of No. 0
The liquid flows back and forth through the narrowed portion 122 which is a gap between the partition wall and the partition wall 10, and a damping force is generated.

That is, the restriction passage 112 is formed as an orifice effective for vibration in a low frequency range, and the narrowed portion 122 is formed as an orifice effective for vibration in a high frequency range.
It can handle vibrations over a wide range of frequencies.

[0007]

However, even with the above-mentioned vibration isolator, there is a range in which the vibration is not sufficiently damped, and it is not possible to sufficiently reduce the vibration such as noise generated at the time of high engine rotation.

In view of the above facts, an object of the present invention is to provide a vibration damping device capable of reliably reducing vibrations of a desired frequency such as noise at high engine speed.

[0009]

According to a first aspect of the present invention, there is provided an anti-vibration device which is connected to one of a vibration generating part and a vibration receiving part and to the other of the vibration generating part and the vibration receiving part. An inner cylinder, an elastic body that is provided between the inner cylinder and the outer cylinder, connects the inner cylinder and the outer cylinder, and deforms when vibration occurs, and expands and contracts the elastic body as at least a part of a partition wall. A main liquid chamber that is capable of being filled with a liquid, a sub liquid chamber that is in communication with the main liquid chamber via a limiting passage and is expandable and contractible, and the elastic body between the inner cylinder and the outer cylinder. A narrowing portion between an intermediate member provided to divide the elastic body into a plurality of portions and a partition wall of the liquid chamber which is connected to the intermediate member and is disposed in any one of the liquid chambers. And a vibrating member to be formed.

A vibration isolator according to a second aspect is the vibration isolator according to the first aspect, wherein the vibrating member is arranged in the main liquid chamber.

The operation of the vibration isolator according to claim 1 will be described below. When the vibration is transmitted from the vibration generating portion side to the inner cylinder or the outer cylinder, the elastic body is deformed, and the main liquid chamber is expanded / contracted accordingly, and a pressure change occurs in the liquid in the restriction passage. And
The sub-liquid chamber expands and contracts through the restriction passage, and the liquid receives passage resistance in the restriction passage or resonates in the liquid column.

Therefore, not only the vibration is damped by the deformation of the elastic body, but also the vibration is damped by the passage resistance of the liquid, the liquid column resonance, or the like, and the vibration is received by the vibration receiving portion side connected to the outer cylinder or the inner cylinder. Vibration becomes difficult to be transmitted.

Further, a vibrating member is connected to an intermediate member provided on the elastic body so as to divide the elastic body into a plurality of parts, and the vibrating member is disposed in any one of the liquid chambers, A narrowed portion is formed between the partition wall.

That is, as a result of partitioning the elastic body into a plurality of parts, each part resonates, and the spring constants differ from each other only by making the resonance points of each part different from each other. The effect of shaking comes to occur.

Therefore, due to the effect of double vibration isolation by the elastic body partitioned by the intermediate member and the effect of liquid column resonance by the vibrating member, the vibration can be damped to a greater extent, resulting in a synergistic high frequency range. Can reduce the transmission rate of the vibration of
It is possible to reliably reduce vibration at a desired frequency such as noise generated when the engine rotates at high speed.

The operation of the vibration isolator according to claim 2 will be described below. The present invention has the same function as the first embodiment. However, since the vibrating member of the present invention is arranged in the main liquid chamber in which the flow of the liquid is considered to be particularly large by using the elastic body as a part of the partition wall, the effect of the vibrating member is further enhanced.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A vibration isolation device 10 according to an embodiment of the present invention is shown in FIGS. 1 to 3, and the present embodiment will be described based on these drawings.

As shown in FIGS. 1 to 3, the outer frame of the vibration isolator 10 according to the present embodiment is composed of a steel outer cylindrical metal fitting 12 formed in a cylindrical shape. An intermediate cylinder 14 also made of steel is inserted and arranged inside.

As shown in FIG. 2, the intermediate cylinder 14 has a pair of flange portions 14B at both ends which are spread outward and are fitted to the inner peripheral side of the outer tubular fitting 12. An intermediate portion of the intermediate cylinder 14 is a small diameter portion 14A formed to have a small diameter, and the intermediate cylinder 14 has a pair of rectangular openings 16 on the upper side of the small diameter portion 14A along the circumferential direction. are doing.

An elastic body 18 made of rubber is vulcanized and adhered to the inside of the intermediate cylinder 14. At the center of the elastic body 18, a steel inner cylinder fitting 2 extending parallel to the axis of the intermediate cylinder 14 is provided.
0 is arranged, and the elastic body 18 is also vulcanized and adhered to the inner tubular member 20. Then, the opening 16 of the intermediate cylinder 14 is covered with a thin diaphragm 24 connected to the elastic body 18.

Further, a recess 18C is formed in a portion of the elastic body 18 below the inner tubular fitting 20, and a notch 14C is formed in the intermediate cylinder 14 in accordance with the recess 18C.

On the other hand, on the outer peripheral side of the small diameter portion 14A of the intermediate cylinder 14, as shown in FIG. 3, a passage forming portion 22 which is connected to the elastic body 18 is vulcanized and adhered in an arc shape to form a small diameter portion of the intermediate cylinder 14. It is arranged between 14A and the outer cylinder fitting 12. A groove portion 22A extending in the radial direction of the intermediate cylinder 14 is formed in the passage forming portion 22.

As described above, a space for forming the main liquid chamber 30 is formed between the concave portion 18C of the elastic body 18 and the inner wall surface of the outer cylinder fitting 12, and the diaphragm 24 on the upper side of the intermediate cylinder 14 and the outer side. A space between the tubular metal fitting 12 and the tubular metal fitting 12 serves as a sub liquid chamber 32 having the diaphragm 24 as a part of a partition wall.

Further, the main liquid chamber 30 and the sub liquid chamber 32 are communicated with each other by a pair of restriction passages 34 constituted by the groove portion 22A of the passage forming portion 22 and the inner peripheral wall of the outer cylinder. A liquid such as water or oil is sealed in the main liquid chamber 30, the sub liquid chamber 32, and the restriction passage 34.

Further, as shown in FIG. 1, the elastic body 18 is
An intermediate plate 42, which is formed so as to extend from the inner tubular metal member 20 in the shape of an arm to the left and right, is arranged so as to surround the inner tubular metal member 20 on the lower side. In this state, the elastic body 18 is vulcanized and adhered to the intermediate plate 42.

Therefore, in the portion of the elastic body 18 between the inner tubular member 20 and the intermediate cylinder 14, a pair of vertically extending separating portions 42A of the intermediate plate 42 divides the elastic body 18 into two. As a result, the elastic body 18 is provided with a pair of outer rubber portion 18A and inner rubber portion 1 by the separating portion 42A of the intermediate plate 42.
8B.

The resonance point of the outer rubber portion 18A is about 400 Hz, and the resonance point of the inner rubber portion 18B is about 80 Hz.
The position of the isolation part 42A and the elastic body 1 so that it is at 0 Hz.
It was decided to adjust the shape of 8 and the like.

On the other hand, in the lower part of the intermediate plate 42, there is formed a connecting portion 42B projecting downward in a cylindrical shape, and a shock absorbing cushioning rubber material 48 is vulcanized and bonded to the periphery of the connecting member 42B. The connecting portion 42B is fitted into the hole 46 of a certain vibration plate 44 and caulked as shown in FIGS. 1 and 2, so that the inner cylinder fitting 20 is excessively displaced below the intermediate plate 42. The vibrating plate 44 made of metal for preventing this is connected and arranged.

That is, the vibrating plate 44 is arranged in the main liquid chamber 30, and the concave portion 18 constituting the partition wall of the main liquid chamber 30 is formed.
A narrow passage-like narrowed portion 38 is formed between the wall surface of C and the narrow wall portion. Therefore, the diaphragm 44 moves up and down as shown by the chain double-dashed line in FIG. 1, so that the small liquid chamber 36 formed between the partition wall of the main liquid chamber 30 and the upper side of the diaphragm 44.
Then, the liquid flows between the main liquid chamber 30 and the main liquid chamber 30 through the narrowed portion 38.

The position of the shaft center of the inner tubular member 20 is in a state where no load is applied to the elastic body 18 (state of FIG. 1).
Thus, it is located slightly above the axis of the intermediate cylinder 14.
The anti-vibration device 10 is inserted and fixed in a mounting frame (not shown) for mounting on the vehicle body.

As described above, when this mounting frame is mounted on the vehicle body and the inner tubular metal fitting 20 is connected to the engine by bolts or the like, the load of the engine is such that the inner tubular metal fitting 20, the elastic body 18, the intermediate cylinder 14, the outer tubular metal fitting 12, It is supported by the vehicle body via a mounting frame. When the load of the engine is applied to the inner tubular metal fitting 20, the axis of the inner tubular metal fitting 20 substantially coincides with the axis of the intermediate cylinder 14.

Next, the operation of the present embodiment will be described. When the vibration is transmitted from the engine side to the inner tubular member 20, the elastic body 18 is deformed, the main liquid chamber 30 is expanded or contracted accordingly, and a pressure change occurs in the liquid in the restriction passage 34. Then, the pressure change is transmitted to the diaphragm 24, which is the wall portion of the sub liquid chamber 32, through the restriction passage 34, and the diaphragm 24 is elastically deformed to expand and contract the sub liquid chamber 32. As a result, the liquid receives passage resistance in the restriction passage 34 or resonates in the liquid column, and not only the vibration is attenuated by the deformation of the elastic body 18, but also the vibration is attenuated by the passage resistance of the liquid or the liquid column resonance. As a result, vibrations are less likely to be transmitted to the vehicle body side connected to the outer tubular fitting 12.

Further, the diaphragm 4 is attached to the intermediate plate 42 provided on the elastic body 18 so as to divide the elastic body 18 into two parts.
4 are connected to each other, the vibrating plate 44 is arranged in the main liquid chamber 30, and a narrowed portion 38 is formed between the diaphragm 44 and the partition wall of the main liquid chamber 30.

That is, between the outer rubber portion 18A and the inner rubber portion 18B of the elastic body 18, the outer rubber portion 18A has a longer free length of rubber than the inner rubber portion 18B, so that the outer rubber portion 18A is softer. Formed, and the spring constants of these are different from each other. For this reason, the resonance points when they vibrate are also different from each other, and when the outer rubber portion 18A is relatively soft, resonance that is surging occurs in the outer rubber portion 18A due to vibration near the low frequency, and as a result, vibration near the high frequency occurs. Resonance occurs in the inner rubber portion 18B due to the vibration.

That is, the outer rubber portion 18A at about 400 Hz
Since the inner rubber part 18B has a resonance point at about 800 Hz, not only the outer rubber part 18A resonates at 400 Hz, but the outer rubber part 18A becomes harder on the higher frequency side than 400 Hz. Since the rubber portion 18B is soft, the rise of the spring constant can be suppressed to a wide range to some extent as a whole.

In addition to this, in the narrowed portion 38 formed between the vibration plate 44 and the partition wall of the main liquid chamber 30, the liquid column resonates at a frequency of 400 Hz at which noise is generated during high engine rotation, Vibration can be reduced.

From the above, the effect of double vibration isolation by the elastic body 18 divided into two by the intermediate plate 42 and the vibration plate 44
Due to the effect of liquid column resonance, the vibration can be greatly reduced. As a result, the transmissibility of the vibration in the high frequency range can be synergistically reduced, and the noise at the high rotation speed of the engine, which occurs at the frequency of about 400 Hz, can be reliably secured. It becomes possible to reduce.

On the other hand, in the above embodiment, the intermediate member and the vibrating member are the plate-like intermediate plate and the vibrating plate. However, the present invention is not limited to this, and may be a block-shaped member or the like. Then, although the vibration plate is arranged on the side of the main liquid chamber, it is not limited to this and may be arranged on the side of the sub liquid chamber.

Further, in the above embodiment, the elastic body is divided into two by the intermediate plate, but not limited to this, it is divided into a plurality of three or more so as to damp vibrations in a wider range of frequencies. Is also good.

On the other hand, in the above-described embodiment, the outer rubber portion of the elastic body is resonated on the low frequency side and the inner rubber portion is resonated on the high frequency side, but the reverse is also possible. Further, in the above embodiment, the outer cylinder is connected to the vehicle body serving as the vibration receiving unit, and the inner cylinder is connected to the engine side serving as the vibration generating unit. However, the reverse configuration may be adopted.

On the other hand, in the embodiment, the purpose is to prevent the vibration of the engine mounted on the automobile. However, the vibration isolator of the present invention can be used, for example, in a body mount of an automobile, or for other purposes other than the automobile. Needless to say
Further, the shape and dimensions of the elastic body and the like are not limited to those of the embodiment.

[0042]

Since the vibration isolator of the present invention has the above-mentioned structure, it has an excellent effect that it is possible to surely reduce the vibration of a desired frequency such as noise at the time of high engine rotation.

[Brief description of drawings]

FIG. 1 is a horizontal cross-sectional view of a vibration control device according to an embodiment of the present invention, which is a cross-sectional view taken along line 1-1 of FIG.

FIG. 2 is a sectional view taken along line 2-2 of the vibration isolator shown in FIG.

FIG. 3 is an exploded perspective view of a vibration damping device according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a conventional vibration damping device.

[Explanation of symbols]

 10 Vibration Isolator 12 Outer Cylinder Metal Fitting 18 Elastic Body 20 Inner Cylinder Metal Fitting 30 Main Liquid Chamber 32 Sub Liquid Chamber 42 Intermediate Plate 44 Vibration Plate

Claims (2)

[Claims] 1. An outer cylinder connected to one of the vibration generator and the vibration receiver, an inner cylinder connected to the other of the vibration generator and the vibration receiver, and between the inner cylinder and the outer cylinder. An elastic body that is provided to connect the inner cylinder and the outer cylinder and is deformed when vibration occurs, a main liquid chamber that is expandable and contractible with the elastic body as at least a part of a partition wall, and a liquid is sealed, A sub-liquid chamber that communicates with the main liquid chamber via a restricting passage and is expandable and contractable, and the elastic body is divided into a plurality of portions in the elastic body portion between the inner cylinder and the outer cylinder. A protection member, comprising: an intermediate member provided; Shaking device. 2. The vibration isolator according to claim 1, wherein the vibrating member is arranged in the main liquid chamber.