JPH11101287A - Liquid-filled air spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid-filled air spring to absorb vibration in an arbitrary direction, suppress a spring constant to a low value regardless of the size of an engine, further generate a high damping force against both high frequency vibration and low frequency vibration, and be suitable for vibration control support for an engine. SOLUTION: This air spring comprises an air chamber C and liquid chambers A and B arranged along an axis crossing orthogonally to a base plate between two base plates 11 and 20 positioned facing each other and is formed such that one of the two base plates 11 and 20 is elastically displaceable in an arbitrary direction from the other. The air chamber C has an air spring function and the liquid chambers A and B are separated into the first liquid chamber A making contact with one 11 of the base plates 11 and 20 and the second liquid chamber B making contact with the air chamber C by a partition plate 16 having an orifice 16a, to provide a vibration damping function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled air spring capable of absorbing vibrations in an arbitrary direction in a three-dimensional space, and more particularly to a liquid-sealed air spring that can be suitably used as an anti-vibration support for a vehicle engine.

[0002]

2. Description of the Related Art As an anti-vibration support for an automobile engine,
Although those made of anti-vibration rubber are known, recently, those in which a liquid chamber and an air chamber are arranged in order below the anti-vibration rubber have been used in order to enhance the vibration damping function. FIG. 5 shows an example, in which a partition plate 3, a rubber diaphragm 4 and a dish-shaped receiving plate 5 are sequentially fixed to the lower end of the vibration-proof rubber 1 via an intermediate cylinder 2, and The first liquid chamber 6A
The first liquid chamber 6A and the second liquid chamber 6B communicating with the orifice 3a on the partition plate 3 are formed below the partition plate 3, and the air chamber 7 is formed below the diaphragm 4 respectively. The upper plate 1a fixed to the upper end of the vehicle is bolted to an engine (not shown) by bolts 8, and the receiving plate 5 is bolted to a hollow bolt 9
To fix to the body frame (not shown).

[0003] A working fluid, for example, ethylene glycol is sealed in the first liquid chamber 6A and the second liquid chamber 6B.
An air pipe (not shown) that encloses air in the air chamber 7 or is connected to the hollow bolt 9
When air of a predetermined pressure is supplied from a controlled pressure supply source via the
The orifice 3 fills the liquid chamber 6A and the second liquid chamber 6B.
a through the liquid chambers 6A and 6B, the vibration is attenuated by the frictional resistance when passing through the orifice, and the volume change of the second liquid chamber 6B accompanying the movement is absorbed by the air chamber 7. ing.

In the above-mentioned conventional apparatus, the engine is supported on a rigid support base composed of the intermediate cylinder 2 and the receiving plate 5 via the vibration isolating rubber 1, so that the engine is supported in the up-down direction, the front-rear direction, and the left-right direction. Vibration can be absorbed, and for the vibration in the low frequency region generated at the time of idling, the damping coefficient can be increased in accordance with the predetermined frequency by setting the diameter and length of the orifice 3a. The rubber 1 is subject to static deflection due to the supporting load. To reduce this, it is necessary to increase the spring constant. In particular, when a large engine is mounted, the above-mentioned spring constant is set in advance to increase the static deflection. Needed to be smaller. Further, in the setting of the orifice for increasing the damping force in the low frequency region, the resistance of the orifice against high frequency vibration generated at high speed rotation makes the flow of the liquid in the liquid chambers 6A and 6B difficult, and Since the viscous friction decreases and the damping force decreases, and the hydraulic pressure in the liquid chambers 6A and 6B increases, there is a problem that the overall spring constant further increases.

In order to solve the above problem, valves and other liquid passages are formed around the partition plate 3 and in the vicinity of the orifice 3a at the center to reduce the resistance of liquid movement between the liquid chambers 6A and 6B in the high frequency region. Although various attempts have been made to make the engine mount, the basic form of the engine mount is to fix the vibration isolating rubber 1 on a rigid support base composed of the intermediate cylinder 2 and the receiving plate 5, so that the engine is As the size increases, the deflection of the vibration isolating rubber 1 due to the static load increases,
In order to suppress this, it is inevitable to increase the spring constant, and it has been difficult to suppress the overall spring constant when the hydraulic pressure rises.

[0006]

According to the present invention, vibrations in an arbitrary direction can be reduced by combining a first liquid chamber and a second liquid chamber communicating with each other in an air spring instead of an anti-vibration rubber. The spring constant can be suppressed regardless of the magnitude of the supporting load, and if the diameter and length of the orifice are set in accordance with the frequency, the supporting load can be maintained in both the low frequency region and the high frequency region. The present invention provides a liquid-enclosed air spring suitable for use as an anti-vibration support for an engine.

[0007]

A liquid-filled air spring according to the present invention is arranged between two opposing substrates along an axis perpendicular to the substrates to connect the two substrates. And a liquid chamber, wherein one of the two substrates can be elastically displaced in an arbitrary direction with respect to the other, the air chamber has an air spring function, and the liquid chamber has an orifice. The liquid crystal display device is characterized by having a vibration damping function divided into a first liquid chamber in contact with one of the substrates and a second liquid chamber in contact with the air chamber by a partition plate provided.

In the present invention, any configuration may be adopted so that one of the substrates can be elastically displaced in an arbitrary direction with respect to the other. The first diaphragm is formed into a cylindrical shape connecting the outer periphery of one substrate and the outer periphery of a partition plate having a difference in diameter with respect to the outer periphery of the substrate, and the small-diameter end portion of the first diaphragm is formed together with the one substrate or the partition plate. The side wall of the second liquid chamber, which is pushed into the inside of the cylindrical portion of the first diaphragm and connects the outer periphery of the partition plate and the outer periphery of the other substrate, is formed into a cylindrical shape with a hard plate made of metal or the like. It is obtained by fixing the outer peripheral edge of a flexible second diaphragm made of rubber or resin inside. In this case, the air chamber mainly compresses and expands due to the displacement in the axial direction perpendicular to the substrate, and the first diaphragm deforms so that the first diaphragm is mainly crushed by the parallel displacement between the substrates to form a gap between the substrates. The first diaphragm and the second diaphragm constituting the air chamber can be easily fixed by absorbing the parallel displacement.

As described above, the side wall of the first liquid chamber is connected to the outer periphery of one of the substrates and the outer periphery of the partition plate having a diameter different from the outer periphery of the substrate by the flexible first diaphragm such as rubber. Formed in the shape, and when the small-diameter side end is pushed into the cylindrical portion of the first diaphragm together with the one substrate or the partition plate, the outer periphery of one of the substrate and the partition plate having a larger diameter, An outer cylinder in contact with the outer surface of the side wall of the first liquid chamber can be protruded, and in this case, a reaction force against the parallel displacement between the substrates is generated, which acts as a spring against the parallel displacement, and its rigidity is Since it is proportional to the pressure of the first liquid chamber, the spring constant of the parallel displacement can be easily set by the supporting load.

The above liquid-filled air spring has one substrate connected to the frame of the vehicle and the other connected to the engine by bolts or the like. And maintained at a predetermined pressure to be used as an engine mount. In this case, either the first liquid chamber or the air chamber may be directed to the engine. When the first liquid chamber is directed toward the engine, the load of the engine is applied to the air chamber via one substrate, the first liquid chamber, and the second liquid chamber.
When the air chamber is directed to the engine, the load of the engine is immediately applied to the air chamber via the other substrate, and the air chamber is supported from below via the second liquid chamber and the first liquid chamber. .
In any case, since the elastic constant of the liquid is significantly larger than that of the gas, the liquid is hardly compressed and the gas is compressed to support the engine at an arbitrary height.

The support height of the engine is arbitrarily set according to the gas pressure. The spring constant of the air spring is arbitrarily set by the pressure and volume of the gas, and is not affected by the size of the engine, that is, the deflection due to the static load. Further, since the product of the gas pressure and the pressure receiving area is a supporting load, by setting the gas pressure to be large, it is possible to use it as a mount for a large diesel engine mounted on a large bus or truck.

When the engine is driven, the vibration is absorbed by the gas. Since the spring constant can be set low irrespective of the magnitude of the static load, vibration can be prevented from being transmitted to the frame even when a large engine is mounted, and not only during idling but also during traveling. And the first
Since the liquid chamber and the second liquid chamber are connected by the orifice, when one of the first liquid chamber and the second liquid chamber is pressurized, 2
The liquid moves between the two chambers via the orifice due to the pressure difference generated between the chambers, and the vibration is attenuated by the resistance at that time. This orifice may be formed by merely making a hole in the partition plate, or may be formed by attaching a cylinder to the partition plate, and the peak value and peak frequency of the damping force are arbitrarily set according to the diameter and length of the orifice. be able to.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 In FIG. 1, reference numeral 11 denotes a circular upper substrate, on which a mounting bolt 12 protrudes upward at the center, and an outer peripheral edge 11 thereof.
a one end bead portion 13a of a diaphragm (first diaphragm) 13 formed of a rubber containing reinforcing fibers into a cylindrical shape and an upper end of a metal outer cylinder 14 are caulked, and this outer cylinder 14 is In contact. The other end bead portion 13b of the diaphragm 13 is caulked to the upper end edge 15a of the inner cylinder 15 having a smaller diameter than the outer cylinder 14, and
By pushing the inner cylinder 15 into a piston shape inside the upper cylindrical portion of the diaphragm 13, the lower half of the diaphragm 13 is bent into a U-shaped cross section as shown in the figure. The outer periphery of a partition plate 16 having a disc-shaped orifice 16a at the center is fixed to the inner surface of the upper end edge 15a of the inner cylinder 15, and a rubber-made upper surface of the outer peripheral portion of the partition plate 16 is fixed. The ring-shaped stopper 17 is fixed.

The outer cylinder 14 and the inner cylinder 15 extend below the curved portion 13c of the diaphragm 13, and a rubber ring-shaped stopper 18 is provided on the outer surface on the lower end side of the inner cylinder 15.
The outer peripheral surface of the stopper 18 is fixed to the outer cylinder 14.
Opposes the inner surface of the lower end portion. The outer peripheral portion of the flexible second diaphragm 19 made of rubber or synthetic resin and the outer peripheral portion of the dish-shaped lower substrate 20 are swaged with the lower substrate 20 down inside the lower edge 15b of the inner cylinder 15. The hollow bolt 21 projects downward at the center of the lower substrate 20. The hollow bolt 21 fixes the lower substrate 20 to a vehicle body frame (not shown) of the vehicle.
The tip is connected to a controlled pressure supply via an air pipe (not shown).

A space surrounded by the upper substrate 11, the diaphragm 13 and the second diaphragm 19 is filled with an arbitrary liquid having a predetermined pressure, for example, ethylene glycol. A first liquid chamber A is provided above the partition plate 16. Second liquid chambers B are formed below the partition plate 16, respectively. Also, the second diaphragm 19
A hollow bolt 21 is provided in a space surrounded by
Pressurized air is introduced from a pressure source through the central hole of
An air chamber C having a predetermined pressure is formed. Then, the upper substrate 11 is fixed to the engine by the center mounting bolts 12, and the lower substrate 20 is fixed to the vehicle body frame by the hollow bolts 21.

In the above structure, the static load generated when the engine is mounted causes the gas in the gas chamber C to be pressurized using the liquid filling the upper substrate 11 and the liquid chambers A and B as a transmission medium. And a predetermined height determined by the pressure receiving area. The vertical component of the vibration generated by driving the engine is transmitted to the pressurized gas via the liquid since the elastic constant of the liquid filling the liquid chambers A and B is significantly larger than that of the pressurized gas in the gas chamber C. The liquid is mainly absorbed by the elastic deformation of the pressurized gas, and the liquid is attenuated by the frictional resistance when moving between the liquid chambers A and B via the orifice 16a. In the first embodiment, since the ring-shaped stopper 17 exists on the upper surface of the partition plate 16, the upper substrate 1
1 can be prevented from contacting the upper end edge 15a of the inner cylinder 15 due to the abnormal lowering.

On the other hand, the horizontal component is
Is deformed, and the liquid is mixed with the orifice 1
The horizontal component is absorbed by the joint action of the elastic deformation of the diaphragm 13 and the elastic chamber C to move between the liquid chambers A and B through the liquid chamber 6a and transmit vibration to the air chamber C. And attenuated by the passing resistance.
In the first embodiment, since the outer cylinder 14 is in contact with the outer surface of the diaphragm 13, the resistance to the deformation of the diaphragm 13 increases in proportion to the liquid pressure. Further, since the ring-shaped stopper 18 is fixed near the lower end of the inner cylinder 15, the diaphragm 1 is actuated by the action of the horizontal component described above.
3 can be prevented from being crushed.

Embodiment 2 In FIG. 2, the upper substrate 11, the mounting bolts 12, the diaphragm (first diaphragm) 13, the outer cylinder 14, the inner cylinder 15, the partition plate 16, the lower substrate 20, and the hollow bolts 21 are the same as those described above. In the second embodiment, the second diaphragm 19A is formed in a bellows shape with one end closed.
The opening is fixed to the upper edge of the inner cylinder 15. Also,
The orifice 16b is formed in a pipe shape, and is fixed to the center of the partition plate 16 so as to face up and down. Note that the ring-shaped stoppers 17 and 18 of the first embodiment are omitted. In the second embodiment, since the second diaphragm 19A is formed in a bellows shape, it can be applied to a configuration in which the inner cylinder 15 is elongated.

Third Embodiment In a third embodiment shown in FIG. 3, a hollow bolt 21 is provided to protrude upward at the center of the upper substrate 11, and an upper cylinder 2 is provided at the outer peripheral edge.
2 is connected to the upper cylinder 22 and the upper substrate 11.
With this, a downward box is formed. The lower end of the upper cylinder 22 is fixed to the second diaphragm 19 of the first embodiment, the respective edges of the partition plate 16 and the outer cylinder 14, and the upper ends of the diaphragm (first diaphragm) 13 respectively. The orifice 16b of the second embodiment is fixed. A hollow piston 23 having a diameter smaller than that of the partition plate 16 is disposed below the partition plate 16, and a lower end of the diaphragm 13 is connected to an upper end of the hollow piston 23.
By pressing the diaphragm 13 (first diaphragm) 13
Is bent into a U-shaped cross section. In addition, piston 2
At the center of the lower end of 3, a mounting bolt 12 projects downward.

In the third embodiment, the upper substrate 11 is fixed to the engine with the hollow bolts 21 and the upper substrate 11 and the second
The space between the diaphragms 19 forms an air chamber C, and is connected to a pressure supply source via a hollow bolt 21 and an air pipe. The space between the second diaphragm 19 and the partition plate 16 forms a second liquid chamber B, and the space below the partition plate 16 forms a first liquid chamber A. The lower end piston 23 is attached to the mounting bolt 12.
And is fixed to a body frame (not shown).

In this case, the height of the upper substrate 11, that is, the mounting height of the engine tends to be higher than in the first and second embodiments, but the air chamber C and the second liquid chamber B are the first liquid chamber. Since it is installed on A, the diameter and volume of the air chamber C can be increased.

Fourth Embodiment In the fourth embodiment shown in FIG. 4, except that the second diaphragm 19 of the third embodiment is fixed to the outer peripheral edge of the upper substrate 11, the other upper substrate 11, the hollow bolt 21, Upper cylinder 2
2. Partition plate 16, orifice 16b, outer cylinder 14, diaphragm 13, hollow piston 23, and mounting bolt 1.
2 is provided in the same manner as the third embodiment, and has the same functions as the third embodiment except that the assembling order can be selected.

[0023]

As described above, according to the present invention, one substrate is connected to the frame of the vehicle and the other is connected to the engine by bolts or the like, and the air chamber is filled with a pressurized gas and used as an engine mount. In this case, the supporting height of the engine and the spring constant as an air spring can be arbitrarily set by the gas pressure, so that the gas pressure is set large without being affected by the size of the engine. Accordingly, it can be used as a mount for a large diesel engine mounted on a large bus or truck. And since it acts as an air spring having a small spring constant, it is possible to prevent the vibration from being transmitted to the frame not only during idling but also during running, even when a large engine is mounted, and is excellent in vibration damping function.

In particular, according to the second aspect of the present invention, the attachment control of the first diaphragm constituting the side wall of the first liquid chamber and the second diaphragm constituting the air chamber is easy. According to the third aspect of the invention, the resistance to the parallel displacement between the two substrates increases, and the rigidity of the first liquid chamber becomes proportional to the internal pressure thereof.
Design becomes easier.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment.

FIG. 2 is a schematic longitudinal sectional view of a second embodiment.

FIG. 3 is a schematic vertical sectional view of a third embodiment.

FIG. 4 is a schematic sectional view of a fourth embodiment.

FIG. 5 is a longitudinal sectional view of a conventional device.

[Explanation of symbols]

11: Upper substrate 12: Mounting bolt 13: First diaphragm (diaphragm) 14: Outer cylinder 15: Inner cylinder 16: Partition plate 16a, 16b: Orifice 17, 18: Ring-shaped stopper 19, 19A: Second diaphragm 20: Lower part Substrate 21: Hollow bolt 22: Upper cylinder 23: Hollow piston A: First liquid chamber B: Second liquid chamber C: Air chamber

Claims (3)

[Claims] An air chamber and a liquid chamber are disposed between two opposing substrates along an axis perpendicular to the substrates and connect the two substrates. One of the two substrates is one of the two substrates. A first liquid chamber configured to be elastically displaceable in an arbitrary direction with respect to the other, the air chamber having an air spring function, and the liquid chamber being in contact with one of the substrates by a partition plate having an orifice; A liquid-enclosed air spring having a vibration damping function divided into a second liquid chamber in contact with the air chamber. 2. A side wall of a first liquid chamber is formed by a flexible first diaphragm into a cylindrical shape connecting an outer periphery of one substrate and an outer periphery of a partition plate having a diameter difference with respect to the outer periphery of the substrate. The side end is pushed into the cylindrical portion of the first diaphragm together with the one substrate or the partition plate, and the side wall of the second liquid chamber connecting the outer periphery of the partition plate and the outer periphery of the other substrate is a hard plate. The air chamber is formed between the second diaphragm and the other substrate by fixing the outer peripheral edge of the flexible second diaphragm inside the second liquid chamber. Item 1
A liquid-filled air spring as described. 3. The liquid-filled type according to claim 2, wherein an outer cylinder in contact with the outer surface of the side wall of the first liquid chamber protrudes from an outer periphery of one of the substrate and the partition plate having a larger diameter. Air spring.