JPH0143854B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fluid-filled mount that achieves a vibration damping effect by utilizing the elastic deformation of an elastic body and the flow resistance of a fluid, and in particular, the present invention relates to a fluid-filled mount that achieves a vibration damping effect by utilizing the elastic deformation of an elastic body and the flow resistance of a fluid. This relates to fluid-filled mounts that change with time.

BACKGROUND ART Conventionally, fluid-filled mounts that combine the functions of elastic deformation of an elastic body and fluid flow resistance have been used, for example, as engine mounts and suspension bushes of automobiles. One type of such a fluid-filled mount includes an inner cylinder member, an outer cylinder member disposed outside the inner cylinder member so that their axes are parallel to each other, and a combination of the inner cylinder member and the outer cylinder member. An elastic body is interposed between the elastic body, and a first fluid chamber and a second fluid chamber are defined so that a predetermined incompressible fluid is sealed in the elastic body, and an incompressible fluid is connected between the fluid chambers. BACKGROUND OF THE INVENTION Devices are known that are configured to allow mutual movement of fluids.

By the way, this type of engine mount requires a large damping force for vibration inputs that cause large displacements at low frequencies, and a low dynamic spring constant for vibration inputs that cause small displacements at high frequencies. be done. However, in the past,
The structure is such that the cross-sectional area and length of the orifice that communicates the first fluid chamber and the second fluid chamber do not change.
Therefore, it has been difficult to simultaneously satisfy the above two requirements. In other words, if the orifice is selected so that the damping function is high in the low frequency range, the dynamic spring constant will be high in the high frequency range.
Conversely, if the orifice is selected so that the dynamic spring constant in the high frequency range is low, the damping performance in the low frequency range will be insufficient.

Purpose of the Invention The present invention has been made under such circumstances, and its purpose is to provide high damping characteristics in the low frequency vibration range and low dynamic spring constant in the high frequency vibration range. An object of the present invention is to provide a fluid-filled mount that satisfies the above requirements at the same time.

Structure of the Invention In order to achieve such an object, the present invention provides a fluid-filled mount including the above-described elastic body and a first fluid chamber and a second fluid chamber formed therein. In the first fluid chamber and the second fluid chamber, the openings of the spaces formed in the elastic body so as to open at one or both end faces in the axial direction are closed with a communication path forming member made of a rigid material. The communication passage forming member is provided with a plurality of communication passages that communicate the first fluid chamber and the second fluid chamber in parallel, and at least one of the plurality of communication passages is defined by a plurality of communication passages. In addition, a valve means is provided which is actuated by input from the outside in a closed state in which the communication passage is closed and in an open state in which it is not closed.

Effects of the Invention Therefore, when a vibration input that causes a large displacement at a low frequency is applied, by closing the valve means by an input from the outside, such a vibration at a low frequency and a large displacement is suppressed. can be effectively attenuated mainly by the flow resistance when the incompressible fluid flows through the unclosed communication path. on the other hand,
When a vibration input with a small displacement is applied at a high frequency, the valve means is brought into an open state by an input from the outside to cause the fluid to flow through a plurality of communication passages. The high frequency and small displacement vibrations can be effectively absorbed mainly by the elastic deformation of the elastic body. As a result, it has become possible to satisfy both the requirements of obtaining a large damping force in the low frequency range and a low dynamic spring constant in the high frequency range, even though it is a single fluid-filled mount. be.

Moreover, since the plurality of communication passages that communicate the first fluid chamber and the second fluid chamber in parallel are formed in the communication passage forming member made of a rigid material, the cross-sectional area of the passages is reduced by the elastic deformation of the elastic body. Stable anti-vibration characteristics are exhibited without fluctuations.

Embodiment Hereinafter, an embodiment in which the present invention is applied to an automobile engine mount will be described in detail based on the drawings.

1 and 2 show an engine mount 2 as a fluid-filled mount, which is an embodiment of the present invention. This engine mount 2 is
Inner cylinder metal fitting 4 as an inner cylinder member and its inner cylinder metal fitting 4
It is equipped with an outer cylindrical fitting 6 as an outer cylindrical member which is arranged concentrically at a predetermined distance on the outside of the cylindrical member, and an annular rubber sleeve 8 is interposed between the inner cylindrical fitting 4 and the outer cylindrical fitting 6. It is made to function as an elastic body. While the outer cylindrical metal fitting 6 is fitted into the cylindrical portion of the bracket 10 fixed to the vehicle body side, a shaft (not shown) fixed to the engine side is inserted inside the inner cylindrical metal fitting 4.

As is clear from FIG. 2, the rubber sleeve 8 has a first fluid chamber 12 and a second fluid chamber 14 formed at symmetrical positions with respect to the center line of the inner cylinder fitting 4. A predetermined incompressible fluid (hereinafter simply referred to as fluid) such as water or polyalkylene glycol is sealed in each of the fluids 14 . First fluid chamber 12
The second fluid chamber 14 has an arcuate cross-sectional shape centered on the center line of the rubber sleeve 8, and extends in the axial direction of the rubber sleeve 8, as is clear from FIG. Both fluid chambers 12 in the axial direction
and 14 have a dead end shape within the rubber sleeve 8, while the other end is opened at one end surface of the rubber sleeve 8.

A flat bottomed cylindrical fixing plate 16 is attached to the end surface of the rubber sleeve 8 on the opening side.
is fixed at the bottom thereof, and integrated with the rubber sleeve 8 in a state in which it is fitted concentrically to one end of the inner cylindrical metal fitting 4 through a central hole formed at the bottom thereof. A pair of windows 18 are formed in the fixing plate 16 and correspond to the respective openings of the first fluid chamber 12 and the second fluid chamber 14. It forms an opening. Therefore, there is an advantage that the opening areas of these openings are always kept constant regardless of the elastic deformation of the rubber sleeve 8.

An annular closing plate 20 is arranged concentrically on the outer surface of the fixing plate 16, and is fitted into one end of the inner cylindrical metal fitting 4 in the center hole, and is also fitted inside the cylindrical part of the fixing plate 16. The closing plate 20 is integrated with the fixing plate 16 by crimping one end of the inner cylinder fitting 4 and the outer peripheral edge of the tip of the fixing plate 16.
8 is blocked. That is, the first fluid chamber 12 and the second fluid chamber 14 are formed by closing the openings of two spaces formed in one axial end surface of the rubber sleeve 8 with the closing plate 20. They are each defined as such.

A pair of windows 1 are provided on the inner surface of the closure plate 20.
8 is formed concentrically with the rubber sleeve 8, and by closing this annular groove 22 with the outer surface of the fixing plate 16, as shown in FIG. A pair of communication passages 24 are formed that communicate the first fluid chamber 12 and the second fluid chamber 14 in parallel. In addition, occlusion plate 2
An annular annular groove 26 having a smaller cross-sectional area is concentrically formed on the inner surface of the fixing plate 16 and is located on the outer peripheral side of the annular groove 22. A pair of communication passages 28 are formed that communicate the chambers 12 and 14 in parallel. The fixing plate 16 and the closing plate 20 are both made of metal and constitute a communicating path forming member. Therefore, regardless of the elastic deformation of the rubber sleeve 8, the communicating paths 24, 28
The cross-sectional area of each passage can always be kept constant.

As a result of the communication passages 24 and 28 being formed as described above, the first fluid chamber 12 and the second fluid chamber 14 are communicated with each other through four parallel communication passages, and one pair of each The communication passages 24 and 28 each form one set, so that the set of communication passages 28 causes a large flow resistance to the fluid flowing therethrough, and the set of communication passages 24 does not give a very large flow resistance. Communication conditions for each set are selected. In other words, the set of communicating passages 28 has a fluid resonance point in a low frequency range (for example, a range of about 7 to 10 Hz), and the set of communicating passages 24 has a fluid resonance point in a high frequency range (for example, a range of about 80 to 200 Hz). Their cross-sectional area, length, etc. are selected so that they have a resonance point.

Each of the communication passages 24, which have a larger cross-sectional area and a shorter length than the communication passages 28, is provided with a solenoid valve 30 as a valve means for opening and closing the communication passages 24.

More specifically, as is clear from FIG. 1, recesses 32 and 34 having depths perpendicular to the communicating passages 24 are located at approximately the midpoints of the respective communicating passages 24 on the fixing plate. 16 and closure plate 20, respectively, and the recesses 32 and 34 have solenoids 36 and 3, respectively.
8 is accommodated and fixed. A movable valve body 40 made of a magnetic material is provided between the solenoids 36 and 38 so as to be movable in a direction substantially perpendicular to the direction of fluid flowing through the communication path 24, and is in close contact with the solenoid 38. It is arranged so that it can take two positions: a closed position where it closes the communication passage 24 and an open position where it comes into close contact with the solenoid 36 and opens the communication passage 24 as shown in FIG. That is, when the solenoid 38 is energized and the solenoid 36 is demagnetized by external energization, the movable valve body 40 is maintained in the closed position, and conversely, while the solenoid 36 is energized, the solenoid 38 is demagnetized. In this state, the movable valve body 40
is kept in the open position.

When the solenoid valves 30 of each communication passage 24 are both open, the fluid flows between the first fluid chamber 12 and the second fluid chamber 14 between the communication passages 24 and 28.
However, if both electromagnetic valves 30 are in the closed state, fluid communication will occur only through the pair of communication passages 28, and in that case, The communication passage 28 is designed to function as an orifice that actively provides resistance to the flow of fluid.

The operation of the electromagnetic valves 30, 30 can be controlled based on, for example, an engine rotation speed signal and a throttle opening signal that are input to the controller from an engine rotation speed sensor, an accelerator opening sensor, or the like. In other words, both solenoid valves 30 are connected to an external controller, and both solenoid valves 30 are changed from an open state to a closed state or closed in response to a sudden increase or decrease in throttle opening in relation to the engine speed. It can be operated from the open state to the open state. However, without automatically controlling the operation of the solenoid valves 30 by the controller, it is also possible to selectively operate the solenoid valves 30 between the open state and the closed state using a manual changeover switch.

By the way, the engine mount 2 configured as described above is manufactured, for example, according to the following steps. First, the fixing plate 16 is fitted to one end of the inner cylinder fitting 4 without caulking.
The inner cylindrical metal fitting 4 and the outer cylindrical metal fitting 6 are arranged concentrically within a predetermined mold. Then, a rubber material is filled between the inner cylindrical metal fitting 4, the outer cylindrical metal fitting 6, and the fixing plate 16, and the rubber sleeve 8 having the first fluid chamber 12 and the second fluid chamber 14 is vulcanized. , the inner cylinder fitting 4, the outer cylinder fitting 6 and the fixing plate 1.
6. Vulcanize and adhere. Next, the thus obtained mount assembly 42 as shown in FIG. 5 and the separately prepared closure plate 20 are assembled.
After installing the solenoids 36 and 38, and setting the movable valve body 40, the mount assembly 42 is immersed in the liquid tank containing the fluid, and the mount assembly 42 is closed inside the fixed plate 16. By fitting the plate 20 and caulking one end of the inner cylinder fitting 4 and the outer peripheral edge of the tip of the fixing plate 16, the fluid chamber 1 is closed.
2 and 14 are filled with fluid, and as shown in FIGS.
The engine mount 2 as shown in the figure is completed.

Such a fluid-filled engine mount 2 is
As mentioned above, for example, the inner tube fitting 4 is attached to the engine (power unit) side, and the outer tube fitting 4 is attached to the vehicle body side via, for example, the bracket 10, and the outer tube fitting 4 is attached to the vehicle body side via, for example, the bracket 10. One fluid chamber 12 and second fluid chamber 14
They will be used in a state where they are almost facing each other.

When the engine mount 2 is subjected to vibrations that cause a large displacement at low frequencies, such as when the vehicle starts and accelerates, stops and brakes, or changes gears, a By closing the two solenoid valves 30 as shown in FIG. 1, the fluids in both fluid chambers 12 and 14 are allowed to flow with each other only through the pair of communication passages 28. As a result, as shown by the solid line A in the graph of Figure 6, the loss coefficient in the low frequency range increases, effectively damping large vibrations at low frequencies, and reducing shocks during starting, braking, etc. eased. Note that even if the solenoid valves 30, 30 are opened and closed using a manual changeover switch,
For example, by closing each electromagnetic valve 30 when driving on a rough road, excessive displacement of the power unit can be effectively suppressed.

On the other hand, when driving at a high engine speed, both solenoid valves 30 are opened as shown in FIG. In addition, mutual circulation is allowed through the communication path 24 as well. As a result, as shown by the broken line C in FIG. 6, the peak of the loss coefficient shifts to the high frequency range side, and accordingly, the dynamic spring constant of the engine mount 2 is represented by the solid line D in the lower graph. Due to the size, the fluid chamber 12,
The fluid in the rubber sleeve 8 is less likely to interfere with the elastic deformation of the rubber sleeve 8, and as a result, the fluid inside the rubber sleeve 8 is mainly
The anti-vibration effect effectively prevents engine chatter noise from being transmitted to the vehicle body.

It is also possible to close only one of the pair of electromagnetic valves 30 and keep the other open depending on the vibration conditions. , E, compared to the case where both the solenoid valve 30 is in the closed state and the open state, the peak of the loss coefficient can be shifted to an intermediate frequency between them, and the dynamic spring constant is accordingly reduced. Since the vibration damping characteristics of the engine mount 2 can also be changed, it is possible to change the vibration damping characteristics of the engine mount 2 into three levels. In any case, by changing the flow resistance given to the fluid by opening and closing the solenoid valve 30, it is possible to obtain a high damping force in the low frequency range and a low dynamic spring constant in the high frequency range. It became possible.

In addition, in the embodiment described above, the solenoid valve 3
0 instead of a solenoid valve 4 as shown in FIG.
4 can also be provided. This electromagnetic valve 44 includes a movable valve body 46 that is movable in a direction perpendicular to the communication passage 24 between a position where the communication passage 24 is closed and a position where it is opened. The solenoid 50 is energized to the open position, and is moved to the closed position by energizing the solenoid 50. However, the structure may be such that it is always biased to the closed position and moved to the open position by electromagnetic force.

Furthermore, in order to move the movable valve body 46 between the closed position and the open position, instead of using the electromagnetic force of a solenoid, for example, the movable valve body 46 shown in FIG. 8 is attached to the piston rod of a fluid pressure cylinder. They can also be connected and actuated between the two positions by means of a cylinder. Alternatively, the movable valve body 46 may be connected to a drive wire and driven between the two positions by a mechanical drive mechanism via the drive wire.

On the other hand, in the embodiment, the rubber sleeve 8
A communicating path forming member consisting of a fixing plate 16 and a closing plate 20 was disposed on one end surface in the axial direction, and a communicating path was formed therein. 8 is also opened in the end face on the opposite side in the axial direction, and a communicating path forming member is disposed on that side as well, and by forming the communicating path 28 in the communicating path forming member, for example, the communicating path 28 is communicated with the communicating path 24. The passage 28 can also be provided separately at both ends of the rubber sleeve 8 in the axial direction. Alternatively, the communicating passages 24 and 28 may be provided side by side at one end in the axial direction, while another communicating passage may be added at the other end in the axial direction.

Further, the formation form of the communication path that connects both fluid chambers 12 and 14 in parallel can be changed in various ways.
For example, as shown in FIG.
2 and 54, which are connected to both fluid chambers 12 and 1 via common passages 56 and 58, respectively.
4, and by arranging, for example, four on-off valves 30 in the middle of each communication path 52 and combining their open/close states, the spring characteristics can be changed more precisely.

Additionally, the fluid chambers are not limited to the first and second fluid chambers, but may also be provided with a third fluid chamber and a fourth fluid chamber facing each other. The invention can be applied not only to the engine mount described above, but also to other anti-vibration mounts, such as suspension bushings of automobiles, for example.

In addition, various modifications and changes may be made based on the spirit of those skilled in the art without departing from the spirit of the present invention.
It goes without saying that the present invention can be practiced with modifications, combinations, etc.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an engine mount as a fluid-filled mount according to an embodiment of the present invention, and shows the - cross section in FIG. Second
The figure is a partially cutaway view of the right side view in FIG. 1. 3 is a conceptual diagram schematically showing the engine mount shown in FIG. 2, and FIG. 4 is a partial sectional view showing the solenoid valve shown in FIG. 1 in an open state. FIG. 5 is an exploded perspective view showing the mount assembly obtained in the manufacturing process of the engine mount shown in FIG. 1 and the like, and the closing plate to be assembled thereto. FIG. 6 is a graph illustrating the effects of the engine mount shown in FIG. 1 and the like. 7 and 8 are partial sectional views respectively showing essential parts of another embodiment of the present invention, particularly another aspect of the valve means. FIG. 9 is a conceptual diagram schematically showing another embodiment of the present invention. 2: Engine mount (fluid-filled mount),
4: Inner tube fitting (inner tube member), 6: Outer tube fitting (outer tube member), 8: Rubber sleeve (elastic member), 12: First fluid chamber, 14: Second fluid chamber, {16: Fixing plate , 20: Closure plate} (communication path forming member),
24, 28, 52, 54, 56, 58: communication path,
30, 44: Solenoid valve, 36, 38, 50: Solenoid, 40, 46: Movable valve body.

Claims (1)

[Scope of Claims] 1. An elastic body is interposed between an inner cylinder member and an outer cylinder member disposed outside the inner cylinder member so that its axis is parallel to the inner cylinder member, and the elastic body has a predetermined shape. A fluid-filled mount is configured such that a first fluid chamber and a second fluid chamber are formed in which an incompressible fluid is sealed, and the incompressible fluid can mutually move between the fluid chambers. In the first fluid chamber and the second fluid chamber, openings of spaces formed in the elastic body so as to open at one or both end faces in the axial direction are closed with communication path forming members made of a rigid material. A plurality of communication passages are provided in the communication passage forming member to communicate the first fluid chamber and the second fluid chamber in parallel, and at least one of the plurality of communication passages is , a valve means is provided which is actuated by input from the outside in a closed state in which the communication passage is closed and in an open state in which it is not closed, and when the valve means is in the open state, vibration is mainly caused by the elastic body. , and when the valve means is operated in a closed state, the vibration is damped mainly by the flow resistance when the incompressible fluid flows through the communication path which is not closed. A fluid-filled mount featuring: 2. The valve means is a solenoid valve comprising a movable valve body movable in a direction substantially perpendicular to the communication passage, and the movable valve body is moved between a position where the communication passage is closed and a position where it is opened. A fluid-filled mount according to claim 1.