JPS60139942A - Tubular bush - Google Patents

Abstract

PURPOSE:To improve the vibration blocking effect and suppressing effect by forming a pair of liquid chambers facing each other in axial direction while holding a partition wall between them in a resilient member placed between inner and outer tubes and differentiating the radial lengths of partition wall and outer wall of each liquid chamber. CONSTITUTION:A resilient rubber member 13 is mounted between an inner tube 11 and an outer 12 arranged coaxially with the inner tube 11. Said resilient member 13 is adhered through vulcanization to the inner tube 11 and an auxiliary ring 15 to be pressure fixed to the innercircumference of outer tube 12 through a seal rubber 14. First and second fluid chambers 17, 17a partitioned by a partition wall 16 made of resilient member such as rubber having lower spring constant than that of resilient member 13 and third and fourth fluid chambers 18, 18a partitioned by the partition wall 16a are formed in the resilient member 13 then each fluid chamber is communicated each other through communication paths 22, 23. Radial length L1 of partition walls 16, 16a is made shorter than the length L2 of outer walls 21, 21a of resilient member 13.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cylindrical pusher including an inner cylinder, an outer cylinder, and an elastic body loaded between the inner cylinder and the outer cylinder.

Prior Art This type of cylindrical bushing is shown in, for example, Nl58AN Service Bulletin No. 428 (published by Nissan Motor Co., Ltd. in September 1980), Part 115, and is a semi-trailing arm type bushing as shown in Fig. 1. Used in suspension 1. That is, in this suspension 1, a 7-arm 6 is supported by a suspension member 2 so as to be able to swing vertically.
A road wheel 4 for wheel attachment is rotatably attached to the swinging end of the wheel. Reference numeral 5 denotes a carriage that houses a differential gear (not shown), and a drive shaft 6 that is branched from the differential gear 7 and rotatably protrudes from the carriage 5 is connected to the road wheel 4. 7 is a strut. Both end portions of the suspension bushing member 20 in the left-right direction of the vehicle are attached to the vehicle body (not shown) via cylindrical bushings S8, and the damping function of the suspension bushing 1 is transmitted from the road surface to the vehicle body by the tubular bushings 8. It is designed to perform a vibration isolation function. By the way, the cylindrical bushing 8 has a
As shown in No. 36151, a plurality of liquid chambers are formed in an elastic body loaded between an inner cylinder and an outer cylinder, with the inner cylinder as a boundary,
There is a liquid-filled cylindrical bushing that efficiently performs the vibration damping function and vibration isolation function by communicating these liquid chambers through communication passages.

However, in this cylindrical bushing filled with liquid, the internal volume of the liquid chamber changes in response to an external force in the direction perpendicular to the axis of the bushing, and the effect is exerted; however, in response to an external force acting in the axial direction, In this case, the internal volume of the liquid chamber hardly changes, and its vibration damping and vibration isolating functions cannot be performed satisfactorily. Therefore, there is a problem in that road noise and noise input in the axial direction of the cylindrical bushing are transmitted to the vehicle body, resulting in muffled noise inside the vehicle.

Purpose of the Invention In view of such conventional problems, the present invention provides a pair of liquid chambers whose volumes are actively contracted and expanded when an external force in the axial direction is applied to the cylindrical bush, and By communicating through a communication path with an orifice effect,
It is an object of the present invention to provide a cylindrical bushing that satisfies both the axial vibration isolation function and vibration damping function by changing the spring constant of the cylindrical bushing against an external force in the axial direction.

Structure of the Invention In order to achieve the above object, the cylindrical bushing of the present invention includes an inner cylinder and an outer cylinder arranged concentrically, and an elastic body loaded between the inner cylinder and the outer cylinder. A pair of liquid chambers are formed in the body so as to face each other in the axial direction of the bush, and the partition wall made of an elastic material between the liquid chambers is made to have a different radial length from the outer wall of the liquid chamber, and It is constructed by communicating the pair of liquid chambers through a communication path.

Effects Due to the above structure, the effects of the present invention are as follows:
The paired liquid chambers have different radial lengths between the partition wall and the outer wall, so when an external force in the axial direction is applied to the cylindrical bushing, the liquid chambers will expand as the elastic body deforms. The volume will contract and the volume within the other liquid chamber will expand. Therefore, resistance occurs when the liquid is moved from one liquid chamber to the other through the communication path, and if the external force is an impulsive unidirectional input or low frequency vibration, the communication path The passage resistance of the generated liquid increases considerably, and the liquid inside the liquid chamber becomes rigid, and the repelling constant of the entire cylindrical push gourd is greatly increased, thereby improving the distribution effect. On the other hand, when a vibration with a high frequency is input, this vibration is absorbed by the elastic body, thereby improving the vibration isolation effect.

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

That is, FIG. 2 shows a cylindrical bushing 1 showing one embodiment of the present invention.
0, a rubber elastic body 16 is loaded between an inner cylinder 11 and an outer cylinder 12 arranged concentrically with respect to the inner cylinder 11. This elastic body 16 is connected to the inner tube 11 and the outer tube 12.
It is vulcanized and bonded to an auxiliary ring 15 which is fitted onto the inner periphery of the ring through a seal rubber 14 by press-fitting or the like. The elastic body 1
A partition wall 1 is disposed within the cylindrical bushing 10 and faces the axial direction of the bushing 10.
A pair of first . The second liquid chamber 17°17a and this first liquid chamber 17°17a. A third liquid chamber 17, 17a and a third liquid chamber 17a are provided symmetrically with respect to the inner cylinder 11 and have a partition wall 161k.
A fourth liquid chamber 18, 188 is formed.

The partition walls 16 and 16a are formed of an elastic body such as rubber having a spring constant smaller than that of the elastic body 16, and are fitted with an annular member 20 and the auxiliary ring 15 that are fitted and fixed to the outer periphery of a flange 19 protruding from the inner cylinder 11. It is vulcanized and bonded between the two. and,
The radial length tl of the partition wall 16.16a is the same as that of the liquid chamber 1.
Outer wall 2 provided on the outside of 7, 17a, 18° 18a
The length t of 1.21& is smaller. By the way, the first and second liquid chambers 17, 17a and the third. Fourth
The liquid chamber 18.18a is communicated by a first communication passage 22.22& formed between the collar portion 19 and the annular member 20,
The first communication path 22. Liquid movement within the second liquid chamber 17.17a and the third. Fourth liquid chamber 18
．． Liquid movement within 18a takes place with the Oriswiss effect. Furthermore, a second communicating path 23 is formed on the outer periphery of the collar portion 19 and communicates with the first communicating path 22, 22&, and the first communicating path 22, 22& is connected to the first communicating path 22& through this second communicating path 26. The second liquid reservoir 17, 17a and the third fluid reservoir 17, 17a. Liquid movement between the fourth liquid chambers 18 and 181L is performed using an orifice effect.

The cylindrical bushing 10 having such a structure is used when attaching the suspension member 2't to the vehicle body (not shown) as shown in FIG. The inner cylinder 11 is attached to the vehicle body via a mounting pin (not shown).

With the above configuration, in the cylindrical push gourd 10 of this embodiment, the communication passages 22, 22 &
The first message was communicated with The second liquid chamber 17°17a and the third
．． Since the fourth liquid chambers ts and tea are formed, when an external force in the axial direction acts on the cylindrical pusher: Llo,
Inner cylinder 11. The outer cylinder 12 moves relatively in the axial direction, and the elastic body 16
is transformed.

In other words, when the outer cylinder 12 in FIG. 2 is moved upward relative to the inner cylinder 11 in response to the upward displacement of the suspension member 2, the elastic body 13 deforms, causing the first degree, the second degree, and so on. Third. Fourth
The internal shape of the liquid chambers 17.17a and 18.18a also changes. At this time, as shown in FIG. 3, since the outer walls 21, 211 are longer in the radial direction than the partition walls 16, 16a, the second. Outer wall 21.21 of fourth liquid chamber 17a, 18a
a tries to approach the partition wall 16.16&, but the first.
The outer wall 21.21& of the third liquid reservoir 17.18 tends to move away from said partition wall 16.16a. Therefore, the second. The internal volume of the fourth liquid chambers 17a and 18a contracts, and the fourth liquid chambers 17a and 18a contract. The internal volume of the third liquid reservoir 17.18 is expanded and these first. 2nd liquid chamber 17.17&Q and 3rd and 4th liquid chamber 18.18
The pressure between & is tried to be balanced by moving the liquid through the first communication path 22.22a. However, if the external force in the axial direction is an impactful displacement load that occurs during bounding or rebounding, a large resistance to fluid movement occurs due to the orifice effect of the first communication passage 22, 221,
Second. The liquid pressure in the fourth liquid chambers 17a and 18a increases significantly and becomes rigid, and the fourth liquid chambers 17a and 18a become rigid.
, 18 & contraction of the internal volume is prevented. Then, elastic body 1
Further deformation of 6 is suppressed, and it becomes as if the spring constant of the entire cylindrical bush 10 has been significantly increased,
Relative displacement in the axial direction between the inner cylinder 11° and the outer cylinder 12 is prevented,
Here, upward displacement of the suspension member 2 is prevented and the vibration damping function is exerted. Similarly, when the suspension member 2 is displaced downward, the first. Second liquid chamber 17.17a
and 3rd. Although the contraction and expansion relationship between the fourth liquid chambers 18, 18 & is opposite to that in the case of upward displacement of the suspension member 2, the breakage function is similarly exerted by the orifice effect of the first communication passage 22, 22a. Ru.

Next, with respect to vibrations such as road noise and harshness transmitted to the suspension member 2, when this vibration is input in the axial direction of the cylindrical pusher 10 fc, the displacement due to such vibration is extremely small, so the elastic body 16 is hardly deformed, and the inside of the 1st and 2nd liquid chambers 17.17a and the 3rd. Regardless of contraction or expansion in the fourth liquid chamber 18.18a, the vibration absorption ability of the elastic body 16 itself prevents the vibration from being transmitted to the vehicle body. Therefore, by setting the spring constant of the elastic body 16 to a small value, the above-mentioned vibration isolation IFIA ability is improved, and it is possible to prevent interior noise caused by road noise, harshness, etc., and improve the quietness of the interior. .

Similarly, in this embodiment, the first. Second liquid chamber 17.
17a and the third set. 4th liquid chamber 18° 18a 1
The first and second sets are arranged opposite to each other with the inner cylinder 11 as a boundary, and the opposing sets are communicated via the second communication path 23, so that the first and second sets are one set. By arranging the second liquid chamber 17.17a and the third and fourth liquid chambers 18.18a in the direction in which the external force acts, that is, in the longitudinal direction of the vehicle, a vibration damping function and a vibration isolation function are achieved in the direction in which the external force acts. can be done efficiently. In other words, the inertial force generated when the vehicle suddenly accelerates or decelerates
0 as an external force in the direction perpendicular to the axis, the first.
Second liquid chamber 17, 17 & and third and fourth liquid chambers 18,
One set of 181L is collapsed, and the other set is expanded, and liquid is transferred through the second communication path 23. Therefore, the orifice effect generated in the second communication passage 26 during this liquid movement prevents the volume of each liquid chamber from changing, and the displacement of the suspension member 2 in the direction perpendicular to the axis of the cylindrical bushing 10, that is, in the longitudinal direction of the vehicle, is prevented. The damping function is effectively exerted.

In addition, the elastic body 1 with a small spring constant can also be used against vibrations that act in the longitudinal direction of the vehicle, such as vibrations such as road noise.
6 will absorb vibration.

FIGS. 4 and 5 show cylindrical pushers L30 and L30a, respectively, showing other embodiments of the present invention, and an inner cylinder 31.31a and an outer cylinder 32
, 32a are provided with a pair of liquid chambers 64, 65 facing each other in the axial direction, as in the previous embodiment.
and 34a, 35a are formed, and these liquid chambers 34.
65 and 64a.

35a are in communication via communication passages 66, 66a.

Here, in the embodiment shown in FIG. 4, the outer shape of the inner cylinder 61 is formed into a so-called drum shape whose diameter gradually increases from both ends toward the center.
The radial length of the outer wall 68 is set to be larger than that of the outer wall 68.

In the embodiment shown in FIG. 5, the inner cylinder 51
By forming the outer shape of a into a shape that gradually decreases in diameter from both ends toward the center,
The outer wall 68a is set to have a smaller radial length than the partition wall 67a.

Therefore, in the embodiment shown in FIGS. 4 and 5, since the partition wall 67.37a and the outer wall 38.38a have different lengths, when an external force in the axial direction is applied, the liquid chamber 64. .3
5 and one of the internal volumes of the liquid chambers 34a and 65a contracts,
Since the other expands, it is possible to improve the vibration damping function and the vibration isolation function against external forces in the axial direction, respectively, similarly to the embodiment shown in FIG.

Same, the cylindrical bushing 60°30 shown in FIGS. 4 and 5 above.
a for each liquid chamber, 54.a, considering only the external force in the axial direction.
35 and 34ae 65a are shown as having an annular shape, but the liquid chambers 64° 65 and 64a, 35 are not limited to this, as described in the embodiment of FIG.
The embodiment of FIG. 2 is achieved by making the liquid chambers 61 and 31m independent so as to face each other with the inner cylinders 61 and 31m as boundaries, and by communicating the independent and opposing liquid chambers through the communication passage. Similarly, it is possible to improve the vibration damping function and vibration isolation function against external forces in the direction perpendicular to the axis.

By the way, in each of the above-mentioned embodiments, the cylindrical bushings 10, 30, 308 used when attaching the suspension member 2t to the vehicle body have been described as an example, but the invention is not limited to this, and the trailing arm type It can be used as a cylindrical bush that connects the arm and suspension member in a suspension tube, and as a link connecting part in a 4-link suspension. Of course, the present invention can be applied to a cylindrical bushing used when attaching a vibrating body to a fixed body.

As described in the detailed description of the invention, the cylindrical pusher of the present invention has the following features:
A pair of liquid chambers are formed in the elastic body to face each other in the axial direction of the bushing, and the partition walls between the liquid chambers and the outer wall are made to have different radial lengths. When an impactful external force in the axial direction is applied to the cylindrical bushing, one of the pair of liquid chambers contracts and the other expands, creating a large resistance to the movement of liquid through the communication path. , further deformation of the elastic body is prevented. Therefore, relative axial movement between the inner cylinder and the outer cylinder is suppressed, thereby improving the vibration damping function in the axial direction of the bush. In addition, there is almost no change in the volume of the liquid chamber due to vibration in the axial direction.
Therefore, by setting the spring constant of the elastic body small, the vibrations are efficiently absorbed by the elastic body, thereby improving the vibration isolator in the bush axial direction. As described above, the present invention improves both the axial distribution function and the vibration isolation function of the cylindrical bushing, so it has the excellent effect of achieving a remarkable improvement in the fc vibration transmission characteristics that could not be achieved in the past. play.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional sun pension using a cylindrical bushing, Fig. 2 is a sectional view of a cylindrical bushing showing an embodiment of the present invention, and Fig. 3 is a sectional view of the cylindrical bushing shown in Fig. 2. 4 and 5 are sectional views of main parts showing the operating state, and sectional views "C" clearly show other embodiments of the present invention. 10, 6n, 30a... Cylindrical bushings, 11.31° 1a...Inner cylinder, 12.62.62a...Outer cylinder, 1
6゜66.33a...Elastic body, 16.37.57a.
...Partition wall, 17, 17a, 18, 18a, 34. 4a
. 65.35a...fluid chamber, 21.21 &, 38,3
8a...Outer wall, 22.56.36a...Communication path. -ReA

Claims (1)

[Claims] (1) An inner cylinder and an outer cylinder arranged concentrically, and their insides. A pair of liquid chambers are formed in the elastic body to face each other in the axial direction of the bushing. A cylindrical bushing having different radial lengths from the outer wall and communicating the pair of liquid chambers via a communication path.