JP4231980B2 - Liquid filled mount - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an anti-vibration technique, and relates to a liquid-sealed mount that is used as an anti-vibration support means for an automobile engine or the like and uses the flow resistance of liquid in a throttle channel for vibration attenuation.
[0002]
[Prior art]
Some of the liquid-filled mounts that elastically support the engine on the body frame are designed not only for vertical input vibration but also for horizontal input vibration. A typical prior art is disclosed in, for example, Japanese Patent Publication No. 63-61533.
[0003]
[Problems to be solved by the invention]
However, according to the above-described prior art liquid-filled mount, the area of the partition between the plurality of liquid chambers formed on the outer peripheral portion of the rubber elastic body is small, and the expansion elasticity is large. The dynamic spring constant with respect to (horizontal direction) is high, and it was difficult to obtain good vibration isolation performance in this direction.
[0004]
The present invention has been made in view of the above-described problems, and the main technical problem is that it is excellent in anti-vibration performance against input vibration in a direction parallel to the axis and orthogonal to the axis. The aim is to achieve both excellent anti-vibration performance against directional input vibration.
[0005]
[Means for Solving the Problems]
The technical problem described above can be effectively solved by the present invention.
That is, the liquid-filled mount according to the present invention is integrally provided between the mount case and the boss disposed on the inner periphery thereof, and is provided integrally with the mount case and the elastic body continuous in the circumferential direction. And a main orifice that is provided on the inner periphery of the mount case to partition between the first liquid chamber on the elastic body side and the second liquid chamber on the diaphragm side and communicates the two liquid chambers with each other. A plurality of circumferentially extending sub liquid chambers are formed in the elastic body, and the elastic body includes a main elastic portion that partitions the first liquid chamber and the sub liquid chamber, and the sub liquid chamber. A sub-elastic portion for partitioning the chamber and the external space, and an elastic rib portion for partitioning the sub-liquid chamber, wherein each elastic rib portion is inclined with respect to a plane passing through the axis of the boss. And a secondary orifice that communicates between the secondary fluid chambers In which but formed.
[0006]
According to the present invention, for displacement input in a direction parallel to the axis of the boss, the sealed liquid moves in the main orifice between the first liquid chamber and the second liquid chamber, For displacement input in the orthogonal direction, the anti-vibration function is exhibited by moving the sealed liquid in the sub-orifice between the plurality of sub-liquid chambers in the circumferential direction. At this time, since the elastic rib portions between the sub-liquid chambers are inclined with respect to the plane passing through the axis of the boss, the area of the elastic rib portion is larger than when formed in parallel to the axis. Since the expansion elasticity is small, the dynamic spring constant with respect to the displacement input in the direction orthogonal to the axis is lowered, and the durability against repeated deformation is also improved.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a first preferred embodiment of a liquid-sealed mount according to the present invention. FIG. 1 (a) is a cross-sectional view cut along a plane passing through an axis, and FIG. 2 is a cross-sectional view taken along a plane perpendicular to the axis at the position of line bb ′ in FIG. In FIG. 1, reference numeral 1 is a metal mounting case, and a lower cup member 12 attached to a vehicle body frame side (not shown) via a mounting bolt 11 and a lower end of the upper flange are caulked to each other by caulking. The outer cylinder 13 is connected. Reference numeral 2 is a boss disposed on the upper inner periphery of the outer cylinder 13 of the mount case 1, and is connected to, for example, the engine side, which is a supported body, via a mounting bolt 21 protruding from the upper surface.
[0008]
Between the boss 2 and the outer cylinder 13 in the mount case 1, an elastic body 3 formed of elastomer is interposed. The elastic body 3 is vulcanized and bonded to the outer peripheral surface of the boss 2 at the inner periphery, and vulcanized and bonded to the inner peripheral surface of the inner cylinder 14 at the outer periphery. The inner cylinder 14 is press-fitted into the inner peripheral surface of the outer cylinder 13, and is fixed between an annular stepped portion 13a formed in the middle in the axial direction and a crimped portion 13b formed at the upper end portion. The outer peripheral portion of the elastic body 3 is fixed to the mount case 1 via the inner cylinder 14.
[0009]
A diaphragm 4 made of an elastomer and an orifice member 5 disposed on the upper side thereof are fixed to a caulking portion 1 a between the cup member 12 and the outer cylinder 13 in the mount case 1. The diaphragm 4 is formed to be sufficiently thin as compared with the elastic body 3, and the cup member 12 has a vent hole 12 for allowing the diaphragm 4 to be freely displaced.
[0010]
The orifice member 5 is provided so as to partition the sealed space between the elastic body 3 and the diaphragm 4 into a first liquid chamber A on the elastic body 3 side and a second liquid chamber B on the diaphragm 4 side. The portion includes a disk-shaped first plate 51 and a second plate 52 which are clamped together and fixed to a caulking portion 1 a of the cup member 12 and the outer cylinder 13 of the mount case 1 together with the diaphragm 4.
[0011]
A main orifice C is formed between the outer peripheral step portion of the first plate 51 and the outer peripheral step portion of the second plate 52 in the orifice member 5. The main orifice C has an end in the circumferential direction, and one end of the main orifice C is opened to the first liquid chamber A through the opening 51a provided in the first plate 51, and the other end. Is opened to the second liquid chamber B through the opening 52 a provided in the second plate 52. Therefore, the first liquid chamber A and the second liquid chamber B communicate with each other through the main orifice C.
[0012]
The main orifice C extends long in the circumferential direction, so that the liquid column resonance frequency of the sealed liquid existing in the main orifice C is low. For example, the displacement frequency in the direction parallel to the axis due to the shake of the engine or the like is approximately the same. It is set to match. When the sealed liquid flows at high speed in the narrow and long flow path formed by the main orifice C, an effective damping force due to flow resistance is generated.
[0013]
The elastic body 3 includes a conical main elastic portion 31 whose outer peripheral side is positioned lower toward the lower end portion of the inner cylinder 14 in contact with the annular step portion 13a of the outer cylinder 13 in the mount case 1, and a disk on the upper side thereof. And a plurality of (four in the illustrated example) elastic rib portions 33 formed at equal intervals in the circumferential direction between the main elastic portion 31 and the sub elastic portion 32. A recess 3a is formed between the elastic rib portions 33, 33,.
[0014]
FIG. 2 is a perspective view showing a vulcanized molded body of the elastic body 3, the boss 2, and the inner cylinder 14. As shown more clearly in FIG. 2, each elastic rib 33 is inclined in a fixed direction with respect to a virtual plane passing through the axis (axis of the boss 2), and the inclination angle is preferably 15 to It is 45 deg.
[0015]
In the inner cylinder 14 vulcanized and bonded to the outer periphery of the elastic body 3, a window portion 14a corresponding to each recess 3a between the elastic rib portions 33, 33,. A groove-like bent portion 14b that is depressed toward the inner diameter side is formed in a portion vulcanized and bonded to the outer periphery of each elastic rib portion 33. Accordingly, a sub liquid chamber D is defined between each of the recesses 3a and the corresponding outer cylinder 13 so as to close the corresponding window portions 14a, and each groove-shaped bent portion of the inner cylinder 14 is formed. Sub-orifices E are formed between 14b and the outer cylinder 13, respectively. The sub liquid chambers D, D adjacent in the circumferential direction communicate with each other through the sub orifice E.
[0016]
The sub-orifice E generates attenuation due to the flow of the filled liquid when a displacement in a predetermined frequency region in a direction orthogonal to the axis is input, and each has the same size (length and cross-sectional area). Alternatively, different liquid column resonance frequencies may be set by using different sizes.
[0017]
Of the elastic body 3, the conical main elastic part 31 that partitions between the first liquid chamber A and the upper sub-liquid chamber D elastically supports a load on the engine side that is a supported body. Since it is the main body, its thickness is larger than that of the disk-shaped secondary elastic part 32 that partitions the upper side of the secondary liquid chamber D. As a result, the main elastic portion 31 is provided with a required supporting force for the load, and the expansion elastic modulus and the radial static spring constant of the sub elastic portion 32 are the expansion elastic modulus of the main elastic portion 31 and It is set to 50% or less of the static spring constant in the radial direction.
[0018]
For example, silicone oil or the like is provided in each of the sealed space including the first liquid chamber A, the second liquid chamber B, and the main orifice C communicating with the first liquid chamber A, and the sub-orifice E communicating with each sub liquid chamber D and the sub orifice E. , Filled with a liquid having an appropriate viscosity. The encapsulated liquid is obtained by incorporating the vulcanized molded body composed of the elastic body 3, the boss 2 and the inner cylinder 14, the diaphragm 4 and the orifice member 5 in the inner periphery of the case in the liquid. A part of the liquid is enclosed when assembling.
[0019]
In the liquid-filled mount according to the first embodiment configured as described above, vibration in the direction parallel to the axis of the boss 2 is input between the body frame side and the engine side, that is, the vertical direction. Then, the mount case 1 and the boss 2 are repeatedly displaced relative to each other in the vertical direction, and the elastic body 3 is repeatedly deformed between the two.
[0020]
When the input vibration is continuous vibration in the vertical direction due to engine vibration of the engine, for example, the liquid in the main orifice C has a large liquid column inertia and hardly flows, but the elastic body 3 (main elasticity The change in the hydraulic pressure in the first liquid chamber A due to the repeated deformation of the portion 31) up and down causes the sealed liquid in the first liquid chamber A to be minutely deformed (expanded deformation) in the main elastic portion 31 in the thickness direction. Is absorbed moderately. As a result, an anti-vibration function against the engine vibration or the like is exhibited.
[0021]
Further, when a vibration of a low frequency band and a large amplitude that causes a large change in hydraulic pressure in the first liquid chamber A, such as an engine shake, is input, the sealed liquid passes through the main orifice C in the first liquid chamber A. And the second liquid chamber B are repeatedly moved by liquid column resonance toward a relatively low pressure side. And since the expansion elastic modulus of the main elastic part 31 is sufficiently high with respect to the fluid pressure change of the first fluid chamber A due to such vibration input, the fluid pressure change of the first fluid chamber A The encapsulated liquid in the main orifice C is surely flowed. Therefore, high damping due to the flow resistance at this time is generated, a good buffering property is obtained, and the vibration is suppressed in a short time.
[0022]
As described above, when the mount case 1 and the boss 2 are relatively displaced only in the vertical direction, each sub liquid chamber D has its volume unchanged even if its shape is changed. There is no flow of the encapsulated liquid inside. In such a displacement, the elastic rib portion 33 inside the elastic body 3 is also deformed, but the elastic rib portion 33 is inclined with respect to a plane passing through the axis of the boss 2 so that the effective length is increased. Therefore, durability against repeated deformation is improved.
[0023]
When vibration displacement in a direction (substantially horizontal direction) perpendicular to the axis of the boss 2 is input, the relative displacement between the mount case 1 and the boss 2 is made in the direction of eccentricity with each other. 3 and the relative displacement of the elastic rib portion 33, the volume of the sub liquid chamber D in the circumferential direction is reduced, and the volume of the sub liquid chamber D on the opposite side is expanded. The secondary elastic part 32 in contact with the secondary liquid chamber D has an expansion modulus and a static spring constant lower than those of the main elastic part, and the elastic rib part between the secondary liquid chambers D. Since 33 is inclined with respect to the plane passing through the axis of the boss 2, the area of the elastic rib portion 33 is large and the expansion elastic modulus is small as compared with the case where it is formed parallel to the axis. Yes. Therefore, when the input vibration is a small amplitude vibration having a relatively high frequency, the volume change (pressure change) of the sub liquid chamber D is absorbed by the expansion elasticity of the sub elastic part 32 and the elastic rib part 33, For this reason, an absolute spring constant falls and effective vibration insulation is exhibited.
[0024]
Further, when the input vibration in the direction perpendicular to the axis of the mount (substantially horizontal direction) is a large amplitude vibration with a relatively low frequency, the volume change of the sub liquid chamber D is caused by the expansion elasticity of the sub elastic part 32. Therefore, the flow of the sealed liquid is generated in the sub-orifice E due to the change in the liquid pressure in the sub-liquid chamber D, and an effective damping force can be obtained by the flow resistance associated therewith.
[0025]
FIG. 3 is a cross-sectional view of a second preferred embodiment of the liquid-sealed mount according to the present invention, cut along a plane passing through its axis. In this embodiment, the vulcanized molded body made up of the elastic body 3, the boss 2 and the inner cylinder 14 has the same configuration as that of the first embodiment shown in FIGS.
[0026]
The difference from the first embodiment will be described. The mount case 1 is illustrated not by the mounting bolt 11 as shown in FIG. 1 but via the brackets 15 and 16 provided on the cup member 12 and the outer cylinder 13. It is designed to be attached to the body frame side that is not.
[0027]
A stirring plate 22 is attached to the inner end (lower end) of the boss 2 via bolts and nuts 23, and the stirring plate 22 is located in the first liquid chamber A. In the illustrated normal state in which only the load due to the engine load is applied to the elastic body 3 via the boss 2, a required clearance is formed between the stirring plate 22 and the inner surface of the elastic body 3.
[0028]
The stirring plate 22 is formed with a notch 22a in a part in the circumferential direction. This notch 22a sets the liquid column resonance frequency of the filled liquid existing in the clearance between the stirring plate 22 and the inner surface of the elastic body 3 in a plurality of frequency bands. This is to improve the vibration absorption performance by lowering the dynamic spring.
[0029]
The orifice member 5 provided so as to partition the sealed space between the elastic body 3 and the diaphragm 4 into the first liquid chamber A on the elastic body 3 side and the second liquid chamber B on the diaphragm 4 side has an outer peripheral portion. A first ring 53 and a second ring 54 which are clamped and fixed to each other in a superposed state on the caulking portion 1a of the cup member 12 and the outer cylinder 13 of the mount case 1 together with the diaphragm 4, and are sealed to the inner periphery thereof. And a sub-diaphragm 55. The main orifice C is formed between the first ring 53 and the second ring 54, and one end of the main orifice C is opened to the first liquid chamber A through the opening 53 a opened in the first ring 53, and the other Is opened to the second liquid chamber B through an opening 54 a formed in the second ring 54.
[0030]
The sub-diaphragm 55 is formed of an elastomer, and the outer peripheral edge thereof is vulcanized and bonded to the inner peripheral edge of the first ring 53 over the entire periphery. The pressure receiving area (contact area with the sealed liquid) of the sub-diaphragm 55 is sufficiently larger than the flow passage cross-sectional area of the main orifice C, and can be bent in the thickness direction by the pressure change in the first liquid chamber A. Is. Further, the liquid column resonance frequency of the first liquid chamber A that acts to deform the sub-diaphragm 55 in the thickness direction is set, for example, in the frequency range of idle vibration of the engine.
[0031]
In the liquid filled mount according to the second embodiment configured as described above, the input vibration in the direction (vertical direction) parallel to the axis of the boss 2 continues in the vertical direction due to, for example, engine vibration of the engine. In the case of natural vibration, the liquid in the main orifice C has a large liquid column inertia and hardly flows, but the first liquid chamber is formed by the elastic body 3 (main elastic portion 31) being repeatedly deformed up and down. The change in the hydraulic pressure of A is effectively absorbed by the liquid column resonating while the enclosed liquid in the first liquid chamber A is deformed in the thickness direction of the sub-diaphragm 55. For this reason, the dynamic spring constant decreases, and excellent vibration insulation against the engine vibration or the like is exhibited. In addition, the stirring plate 22 in the first liquid chamber A is oscillated and displaced integrally with the boss 2 by vibration input, and accordingly, the surrounding sealing liquid is repeatedly moved to generate a damping force.
[0032]
In addition, vibrations in the low frequency band and large amplitude that cause a large change in hydraulic pressure in the first fluid chamber A, such as engine shake, and vibrations in a direction (substantially horizontal) perpendicular to the axis of the boss 2 are generated. For input, the same operations and effects as the first embodiment described above are exhibited.
[0033]
【The invention's effect】
As described above, according to the liquid-sealed mount according to the present invention, the inside of the sub-orifice is sealed between a plurality of sub-liquid chambers in the circumferential direction against vibration input in a direction perpendicular to the axis of the mount case. A damping function can be obtained by the movement of the liquid.
[0034]
And since the elastic rib part which partitions off between adjacent sub liquid chambers inclines with respect to the plane which passes along the axis of a mount case, compared with the case where it is formed in parallel with the axis, the elastic rib part The expansion elasticity is small, and therefore the dynamic spring constant with respect to the displacement input in the direction orthogonal to the axis is low, and excellent vibration insulation is obtained. Moreover, since the effective length to which the elastic rib portion is subjected to deformation is longer than that in the case where it is formed parallel to the axis, durability against repeated deformation can be improved.
[Brief description of the drawings]
1A and 1B show a first preferred embodiment of a liquid-sealed mount according to the present invention, in which FIG. 1A is a cross-sectional view cut along a plane passing through an axis, and FIG. It is sectional drawing cut | disconnected by the plane orthogonal to an axial center in b 'line position.
FIG. 2 is a perspective view showing a vulcanized molded body of an elastic body, a boss and an inner cylinder in the liquid-filled mount.
FIG. 3 is a cross-sectional view of a second preferred embodiment of a liquid-sealed mount according to the present invention, taken along a plane passing through its axis.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mount case 2 Boss 22 Stirring plate 3 Elastic body 31 Main elastic part 32 Sub elastic part 33 Elastic rib part 4 Diaphragm 5 Orifice member A First liquid chamber B Second liquid chamber C Main orifice D Sub liquid chamber E Suborifice

Claims (1)

An elastic body (3) provided integrally between the mount case (1) and the boss (2) disposed on the inner periphery thereof and continuous in the circumferential direction;
A diaphragm (4) provided integrally with the mount case (1);
Provided on the inner periphery of the mount case (1) and partitioning the first liquid chamber (A) on the elastic body (3) side and the second liquid chamber (B) on the diaphragm (4) side, and An orifice member (5) provided with a main orifice (C) for communicating both liquid chambers (A, B) with each other;
A plurality of circumferential auxiliary liquid chambers (D) are formed in the elastic body (3),
The elastic body (3) includes a main elastic part (31) that partitions the first liquid chamber (A) and the sub liquid chamber (D), and a space between the sub liquid chamber (D) and the external space. It consists of a secondary elastic part (32) for partitioning and an elastic rib part (33) for partitioning between each of the secondary liquid chambers (D),
Each elastic rib portion (33) is inclined with respect to a plane passing through the axis of the boss (2), and a sub-orifice (E) is formed to communicate between the sub-liquid chambers (D, D). A liquid-filled mount characterized by that.

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