JPS60172743A - Vibro-isolating bush - Google Patents

Abstract

PURPOSE:To effectively prevent transmission of vibration in an equipment or a device suitable for engine mount by providing the equipment or the device with a function of damping low frequency vibration covering any direction in the circumferential direction of a vibro-isolating bush. CONSTITUTION:A vibro-isolating bush 1 has an intermediate sleeve 4 between an internal sleeve 2 and an external sleeve 3. Primary and secondary fluid chambers 7 and 8 communicated with each other via a primary orifice 9 are formed in a primary resilient member 5 which is disposed between the intermediate and external sleeves 4 and 3 while third and fourth chambers 10 and 11 which are communicated with each other via secondary orifice 12 are formed at right angles with the arranged direction of the primary and secondary fluid chambers 7 and 8 in a secondary resilient member 6 disposed between the internal and intermediate sleeves 2 and 4. Low frequency vibration can be attenuated in not only one direction but also other directions.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cylindrical anti-vibration bushing used when a vibrating body is attached to a fixed body with a vibration-isolating function.

BACKGROUND ART Conventionally, a power unit (in which a clutch, a transmission, etc. are integrally coupled to an engine body) mounted on a vehicle such as an automobile is attached to the vehicle body via an engine mount. In this engine mount, one of the 10,000 parts is the power 22 parts, and the other part is loaded with rubber as an elastic body between the inner cylinder and the outer cylinder, which are installed on the vehicle body side. There is a cylindrical anti-vibration bushing that absorbs engine vibrations using the elastic body. However, this engine vibration can be roughly divided into a low-frequency large-amplitude region that occurs during idling, etc., and a high-frequency no-amplitude region that occurs during high rotation. is not vibration absorption, but rather displacement regulation of the power unit, and the latter function required at high frequency and small amplitude is original vibration absorption. Therefore, the elastic body is required to have contradictory elements: a high spring constant necessary for regulating displacement and a low spring constant necessary for absorbing vibration. For this reason, the elastic body has to be set at the midpoint between these conflicting elements, which may cause idling vibrations in the low frequency range or stiff vibrations at the beginning of running to occur in the vehicle body, and muffled noise in the single room in the high frequency range. may occur. Therefore, in the past, the special public service was designated as 48-36151 or 5
8-17061.0, a pair of fluid chambers are provided in the elastic body of the anti-vibration bushing, facing each other with an inner cylinder as a boundary, and communicating with each other through i+) fins. The damper action when the indoor liquid moves through the orifice attenuates the low-frequency, large-amplitude region, and the elastic body itself exclusively absorbs vibrations in the high-frequency, small-amplitude region, thereby regulating displacement. Both vibration absorption functions in 1
There are some models that are satisfied with just one anti-vibration bushing.

However, in such conventional anti-vibration bushings,
Since one pair of fluid chambers is arranged in only one direction, the damping of low frequency low motion is effective only in the direction in which the fluid chambers are arranged. However, the low-frequency vibrations of the power unit include various vibrations such as idle vibration, jerky vibration when starting, and even shake vibration, and the vibration direction is not necessarily unidirectional, but relative to the arrangement direction of the fluid chamber. It also works in the right angle direction.

OBJECTS OF THE INVENTION In view of the conventional situation, it is an object of the present invention to provide a vibration-proof bushing in which low-frequency vibrations are attenuated not only in one direction but also in other directions.

Composition of the invention In order to achieve this objective, the present invention is intended to achieve this objective.

An intermediate cylinder and an outer cylinder are arranged approximately concentrically, a first elastic body is loaded between the intermediate cylinder and the outer cylinder, a second elastic body is loaded between the inner cylinder and the intermediate cylinder, and the A pair of first and second fluid chambers are formed in the first elastic body facing each other with an intermediate cylinder as a boundary, and a pair of first and second fluid chambers are formed in the second elastic body facing each other with an inner cylinder as a boundary. A pair of third fluid chambers are arranged in a negative angle direction with respect to the arrangement direction of the second fluid chamber.
．． forming a fourth fluid chamber; The second fluid chamber and the third and fourth fluid chambers are configured to communicate with each other through a first orifice and a second orifice, respectively.

Example Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

That is, FIGS. 1 and 2 show a vibration-proof bushing 1 showing one embodiment of the present invention, in which an intermediate cylinder 4 is provided between an inner cylinder 2 and an outer cylinder 6, and these inner cylinders 2. Intermediate cylinder 4. The outer cylinders 6 are arranged concentrically in the attached state. The outer cylinder 6 and the intermediate cylinder 4 each have a first cylinder which is press-fitted. Second
The outer cylinders 3a, 3b and the first. It is composed of second intermediate cylinders 4a and 4b. A first elastic body 5 molded from rubber is loaded between the intermediate cylinder 4 and the outer cylinder 6, and a second elastic body 6 similarly molded from rubber is loaded between the inner cylinder 2 and the intermediate cylinder 4. The first elastic body 5 is vulcanized and bonded to the second outer cylinder 66 and the first intermediate cylinder 4a, and the second elastic body 6 is vulcanized and bonded to the second intermediate cylinder 4b and the inner cylinder 2. There is. Said first
Inside the elastic body 6 are first fluid chambers 7 facing each other with the intermediate cylinder 4 as a boundary. A second fluid chamber 8 is formed. These first. Second
A liquid such as water (incompressible fluid) is injected into the fluid chamber 7.8, and the fluid is injected into the fluid chamber 7.8 through a tubular first orifice 9 buried in the outer four circumferences of the first elastic body 6. 1. A second fluid hole 7.8 is in communication with the second fluid hole 7.8.
A pair of third. A fourth fluid chamber 10.11 is formed. These third. Fourth fluid chamber 1
Welfare first within 0.11. Similarly to the second fluid reservoirs 7 and 8, a liquid such as water is injected into the third and fourth fluid reservoirs via a tubular second oriice 12 embedded in the inner circumference of the second elastic body 6. 10 and 11 are connected.

In the anti-vibration bushing 1 having such a structure, the inner cylinder 2 is attached to a single unit as a fixed body via a bolt (not shown) inserted into the inner cylinder 2, and the outer cylinder 6 is attached as a vibrating body. It is designed to be installed on the power unit side.

With the above configuration, when vibrations in the low frequency, wide amplitude range, such as idle vibrations, jerky vibrations, and shear vibrations, occur in the power unit, the first problem occurs. A damping effect when the liquid in the second fluid chamber 7, 8 moves through the first orifice 9, or a third. a damping effect when the liquid in the fourth fluid INO, 11 moves through the second orifice 12;
Alternatively, these two damper actions work together to efficiently damp nil low frequency vibrations. That is, 1st. 2nd fluid mine 7,
For the swing kJJK in the arrangement direction of No. 8, the first. Volume changes in the second fluid chambers 7 and 8 (one bulges and the other contracts, and the tamper action at this time reduces wall movement. At this time, the third and fourth fluid chambers? There is no volume change within 0.11, there is no damping action between the third and fourth fluids, and there is no necessity to perform a damping action. For vibrations in the arrangement direction of the chambers 10.11, these third and fourth fluid chambers 10.11
Vibration damping is achieved by the damper action between the two. At this time, no damper action is performed between the first and second fluid chambers 7 and 8. Like this in history, the first. The second fluid chamber 7, 8 direction and the third fluid chamber in the direction perpendicular to this direction. Fourth fluid chamber 10.11
Not only is vibration damping performed efficiently in the photographing direction, but also component force components of the vibration input in the two directions act on vibration input in an oblique direction with respect to the two directions. 1st. The second fluid chambers 7, 8 and the third.
A damping force corresponding to the component force component acts on the other side of the fourth fluid chamber 10.11, and a damping force also acts on the low-frequency vibration input in the diagonal direction. In this way, 1. In the anti-vibration bushing 1 of this embodiment, the attenuation function works against low-frequency vibration input in all directions (circumferential direction), and the low-frequency vibration is transmitted to the vehicle body. can be efficiently prevented.

Same, the above-mentioned anti-vibration pusher: =-1 indicates the one used as a support mount for the knocker unit, and the inner cylinder 2 is on the vehicle body side.
Although the outer cylinder 3 is shown attached to the power unit side, this is reversed so that the inner cylinder 2 is attached to the power unit side and the outer cylinder 6 is attached to the power unit side.
may be mounted on the vehicle body side, and furthermore,
The anti-vibration pushbutton of the present invention: L can be used when attaching a general vibrating body to a fixed body without having to use the support blunt of the power unit.

As described in detail, the vibration isolating fish of the present invention has the first elastic body loaded between the intermediate cylinder and the outer cylinder, and the first and second fluids 4281 applied through the first orifice. The second elastic body, which forms a chamber, is loaded between the inner cylinder and the intermediate space. The third fluid is communicated through the second orifice 7 in a direction perpendicular to the arrangement direction of the second fluid. Since the fourth fluid chamber is formed, not only the direction of the first and second fluid chambers but also the direction of the third fluid chamber. Low frequency vibrations in the direction of the fourth fluid chamber can be damped. The damping function can also be achieved against vibration input in a diagonal direction with respect to the fourth fluid tail direction. Therefore, the damping function is activated against low-frequency vibrations in all directions in the circumferential direction of the anti-vibration bushing, and the excellent effect is that low-frequency vibrations on the vibrating body side can be efficiently prevented from being transmitted to the fixed body side. shoulder. .

[Brief explanation of the drawing]

The first figure is a central cross-sectional view showing one embodiment of the anti-vibration bushing of the present invention, and the second figure is a cross-sectional view taken along line B of the first line. 1... Anti-vibration bushing, 2... Inner cylinder, 6... Outer cylinder,
4... Intermediate cylinder, 5... First elastic body, 6... Second elastic body, 7... First fluid presentation, 8... Second fluid presentation, 9.
...First orifice, 10...Third fluid chamber, 11...
- Fourth fluid chamber, 12... second orifice dog. Figure 1

Claims (1)

[Claims] (1) An inner cylinder, an intermediate cylinder, and an outer cylinder are arranged approximately concentrically, and a first elastic body is loaded between the intermediate cylinder and the outer cylinder, and a second elastic body is loaded between the inner cylinder and the intermediate cylinder. The first elastic body is loaded with a pair of first elastic bodies facing each other with an intermediate cylinder as a boundary. A second fluid chamber is formed, and a pair of third and fourth fluid chambers are formed in the second bullet body, facing each other with a cylinder as a boundary, and extending in a direction perpendicular to the arrangement direction of the first and second fluid chambers. forming the first. Second
the fluid chamber and the third. A vibration-proof bushing characterized by a joint that communicates the fourth fluid chamber through the first orifice and the second orifice, respectively.