JPH0729318Y2 - Fluid-filled cylinder mount device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fluid-filled cylindrical mount device that suppresses the transmission of vibrations based on the flow of a fluid enclosed therein, and particularly in a high frequency range. The present invention relates to the structure of a fluid-filled tubular mount device in which the improvement of vibration damping characteristics can be achieved extremely advantageously.

(Background Art) Conventionally, a mount device that is interposed between two members that constitute a vibration transmission system and that connects both members in a vibration-proof manner or supports one member in a vibration-proof manner with respect to the other member. As a type, a tubular mount device is used in which an inner tubular metal member and an outer tubular metal member, which are concentrically or eccentrically arranged to each other, are elastically connected by a rubber elastic body interposed therebetween. Has been done. For example, a so-called cylindrical engine mount, which is widely used as an engine mount for FF type automobiles, is such.

Conventionally, in the cylindrical mount device having such a structure, the vibration-proof function is provided only by the elasticity of the rubber elastic body. However, in recent years, the required characteristics of noise and vibration in automobiles have been improved. Accordingly, it is becoming difficult to cope with such a structure, and therefore, at present, it has been attempted to improve the vibration damping characteristics of such a cylindrical mount device by enclosing a fluid in the mount.

Therefore, the applicant of the present application has previously applied for Japanese Patent Application No. 63-152961 as one mode of such fluid encapsulation, and a predetermined non-compression is applied between the inner and outer cylindrical metal fittings connected by a rubber elastic body. A fluid chamber, in which a vibration-proof vibration is input, in which a permeable fluid is enclosed, is provided, and the action of projecting from one side of the inner tubular fitting and the outer tubular fitting toward the other side into the fluid chamber is provided. A fluid-filled cylindrical mount device having a structure in which a vibration acting portion having a predetermined gap can be formed between the acting protrusion and the inner surface of the fluid chamber by providing a protrusion is proposed. In the mounting device having such a structure, a low dynamic spring is achieved based on the flow or resonance of the fluid generated in the vibration acting portion at the time of vibration input, and especially vibration against input vibration in the high frequency range is achieved. The transmissibility can be reduced.

By the way, in the mount device having such a structure, the frequency range in which the dynamic spring can be reduced by the flow or resonance of the fluid in the vibration acting portion basically changes the size of the vibration acting portion. However, the maximum frequency at which the low dynamic spring effect based on the fluid flow or resonance in the vibration acting portion can be effectively exhibited is the frequency range in which such tuning is possible. Although it varies depending on various dimensions and the material of the rubber elastic body, the mount device actually used is naturally limited by the basic required specifications such as the shape and size of the mount, and static characteristics. For example, the outer diameter is about 80mm, the axial length is about 55mm, 105k
In a mounting device in which the amount of deformation (relative displacement of the inner and outer tubular fittings) when a gf load is input is set to approximately 7 mm, good prevention is achieved due to the resonance action of the fluid that is caused to flow in the vibration action part as described above. It has been measured that the frequency range where vibration performance can be obtained is up to about 400 to 500 Hz.

However, in recent high-grade vehicles and the like, it is sometimes required to reduce the vibration transmissibility even with respect to input vibration in a higher frequency range. It is necessary to achieve a low dynamic spring when a vibration input in a higher frequency range is satisfied while satisfying specific requirements.

(Problem to be Solved) Here, the present invention has been made in the background of the circumstances as described above, and the problem to be solved is as follows.
(EN) Provided is a fluid-filled tubular mount device having an improved structure, which can advantageously achieve a low dynamic spring for input vibration in a higher frequency range and can reduce the vibration transmissibility over a wider frequency range. It is in.

(Solution) In order to solve such a problem, in the present invention, an inner tubular metal member and an outer tubular metal member that are concentrically or eccentrically arranged at a predetermined distance in the radial direction are provided. A predetermined incompressible fluid is obtained by elastically connecting with a rubber elastic body interposed between the rubber elastic body and by closing the pocket opening on the outer peripheral surface of the rubber elastic body with the outer tubular metal fitting. To form a fluid chamber into which vibration to be isolated is input, and further projects into the inside of the fluid chamber from the side of the outer tubular fitting toward the side of the inner tubular fitting, and the vibration input direction In the fluid-filled cylindrical mount device, an action protrusion that forms a vibration action portion with a predetermined gap is provided between the pocket portion that constitutes the fluid chamber inner surface and the substantially W-shaped bottom surface, Opposes the pocket portion with the inner tubular metal member interposed therebetween. As described above, an elastic wall portion that axially penetrates the rubber elastic body and forms a thinned portion that extends over substantially a half circumference in the circumferential direction, and is capable of elastically deforming bottom walls on both sides in the circumferential direction of the pocket portion. On the other hand, under the mounted state of the mounting device, in the fluid chamber, the vibration acting portion between the acting protrusion and the bottom surface of the pocket portion has a gap of 1 to 16 mm and is formed on substantially the entire surface of the elastic wall portion. It is configured to be located across,
(B) In the vibration input direction between the inner and outer tubular metal fittings, the action projection is fixed to the outer tubular metal fitting and is fixed to the outer tubular metal fitting through a connecting rubber elastic body. And a movable part made of a hard material, which has a substantially W-shaped facing surface corresponding to a rubber elastic body shape that provides a bottom surface of the pocket portion in a mounted state of the mounting device, the movable portion being relatively displaceable. That is the feature.

(Embodiment) Hereinafter, in order to more specifically clarify the present invention, one embodiment of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 show, as an embodiment of the present invention, a specific example in which the present invention is applied to an engine mount for an FF type automobile.

In this figure, reference numeral 10 denotes an inner tubular metal fitting, and an outer tubular metal fitting 12 is arranged on the outer side of the inner tubular metal fitting 12 while being eccentrically arranged in one radial direction (vertical direction in FIG. 1) with a predetermined distance. Further, a rubber elastic body 14 having a substantially cylindrical shape is interposed between the inner tubular metal fitting 10 and the outer tubular metal fitting 12, and the rubber elastic body 14 is provided.
The inner and outer tubular metal fittings 10 and 12 are integrally and elastically connected.

Further, in the engine mount 16 in the present embodiment, a mounting rod provided on the vehicle body side is inserted and fixed to the inner tubular metal fitting 10, while the outer tubular metal fitting 12 is a mounting hole of a bracket provided on the engine unit side. By being press-fitted and fixed inside, the engine unit is interposed between the engine unit side and the vehicle body side, and the engine unit is vibration-isolatedly supported with respect to the vehicle body. Further, in such a mounted state, the inner and outer tubular metal fittings 10 and 12 are positioned substantially concentrically by the weight of the engine unit (see FIG. 3), and the main eccentric directions of the both metal fittings 10 and 12 are mainly. Vibration will be input.

More specifically, the inner tubular metal member 10 is formed in a thick-walled cylindrical shape, and further, a radial direction outwardly of the thin-walled cylindrical mounting sleeve 18 is separated by a predetermined distance. It is eccentrically arranged by a predetermined amount.

And, between these inner tubular fitting 10 and the mounting sleeve 18,
The rubber elastic body 14 is interposed so that the rubber elastic body 14 has an inner cylindrical metal member 10 on its inner peripheral surface.
However, the mounting sleeve 18 is formed on the outer peripheral surface as a vulcanization-bonded integrally molded article.

Further, the rubber elastic body 14 is attached to the inner tubular metal fitting 10 on the side where the separation distance is small in the eccentric direction between the inner tubular metal fitting 10 and the mounting sleeve 18, which is the mount radial direction in the vibration input direction. A lightening portion 20 is formed which penetrates the sleeve 18 in the axial direction and extends over substantially half the circumference in the circumferential direction. The lightening portion 20 can reduce the occurrence of tensile stress in the rubber elastic body 14 when the load in the bounding direction such as the weight of the engine unit or the vibration load as described above is exerted. It has become.

Furthermore, the rubber elastic body 14 has a portion facing the above-described lightening portion 20 in the radial direction with the inner tubular metal fitting 10 interposed therebetween, in other words, the eccentric direction between the inner tubular metal fitting 10 and the mounting sleeve 18. On the side where the separation distance is large, the pocket portion 22 is formed with a recessed shape that penetrates the wall portion of the mounting sleeve 18 and opens on the outer peripheral surface. In short, the mounting sleeve 18 has a pocket 22 provided on the rubber elastic body 14.
A window portion 26 is provided at the opening portion of the above, and the pocket portion 22 is opened to the outside through the window portion 26. The bottom walls on both sides in the circumferential direction of the pocket portion 22 are elastic wall portions that are easily elastically deformed due to the existence of the lightening portion 20.

Incidentally, here, the mount axial wall portions 24, 24 of the pocket portion 22 constituted by the rubber elastic body 14 are provided.
As is clear from FIG. 2, the is made relatively thin so that its elastic deformation in the mount axial direction can be allowed relatively easily. Also, such rubber elastic body
In the case of 14, the inner and outer tubular metal fittings 10,
Since the generation of tensile stress is avoided when a vibration load is input between the two parts, elastic deformation in the mount radial direction when a vibration load is input is generated with respect to the pocket portion 22 formed at the site where the compressive stress is generated. , Which is extremely advantageous.

Then, the outer tubular metal fitting 12 is externally inserted to the integrally vulcanized molded product including the inner tubular metal fitting 10, the rubber elastic body 14 and the mounting sleeve 18, and the outer tubular metal fitting 12 is further reduced in diameter. Is applied, and is fitted to the outer peripheral surface of the mounting sleeve 18, and roll crimping is applied to both axial end portions thereof,
By engaging with both ends of the mounting sleeve 18, the integrally vulcanized molded product and the outer tubular fitting 12 are integrally assembled. Then, the opening of the pocket portion 22 is fluid-tightly closed by the outer insertion of the outer cylinder fitting 12, and the fluid chamber 30 having a predetermined volume is defined therein. A thin-walled seal rubber layer 28 is integrally provided on the inner peripheral surface of the outer cylindrical metal member 12 over substantially the entire surface thereof, and the thin seal rubber layer 28 is pressed against the mounting sleeve 18. The liquid tightness of the fluid chamber 30 can be advantageously ensured.

In addition, the assembly of the outer cylinder metal fitting 12 in the fluid chamber 30 is
A predetermined low-viscosity incompressible fluid is enclosed by being performed in a predetermined fluid. As the enclosed fluid, in order to achieve the object of the present invention, in order to ensure sufficient fluidity of the fluid, one having a kinematic viscosity of 500 centistokes or less, preferably 100 centistokes or less is desirable, for example, Water, ethylene glycol, propylene glycol, other alkylene glycols, low-viscosity polyalkylene glycols, low-viscosity silicone oils, or mixed solutions thereof are preferably used.

In the fluid chamber 30, the inner and outer tubular metal fittings 1
At the time of inputting vibration between 0 and 12, vibration to be isolated is input thereto, but at that time, elastic deformation outward in the mount axial direction in both axial direction side wall portions 24, 24 of the fluid chamber 30, Alternatively, since both side walls in the circumferential direction of the fluid chamber 30 (pocket part 22) are elastic wall portions that can be elastically deformed, bulging deformation of the both side wall parts in the circumferential direction into the lightening portion 20 is caused. The deformation in which the inner dimension of the fluid chamber 30 is changed can be generated.

In particular, in this way, the rubber elastic body 14 forming the wall portion of the fluid chamber 30 has a certain degree of freedom of deformation at the time of vibration input due to the presence of the lightening portion 20, so that at the time of vibration input. ,
The elastic deformation of the rubber elastic body 14 is caused, and the repeated flow of the fluid in the vibration acting portion 44, which will be described later, is extremely advantageously induced. It is possible to more effectively reduce or prevent the increase in the dynamic spring due to.

Furthermore, in the fluid chamber 30 formed as described above, the protruding block 32 is housed and arranged inside the fluid chamber 30.

Here, in the projecting block 32, a substantially arc-shaped block-shaped fixing portion 34 having an outer peripheral surface along the inner peripheral surface shape of the outer tubular metal member 12 forming the outer wall of the fluid chamber 30, and the fluid chamber 30. And a movable portion 36 having a curved plate shape along the substantially W-shaped inner peripheral surface shape of the pocket portion 22 constituting the inner wall of the above, and the fixed portion 34 and the movable portion 36 have a connecting rubber elastic body 38. As a whole, the inner peripheral surface of the fluid chamber 30 is elastically coupled by the mount 16 as shown in FIG. 3 in a mounted state, that is, under a heavy load condition of a supported body (engine unit). It is formed with an outer shape that provides a substantially W-shaped facing surface that substantially corresponds to the shape.

The material for forming the fixed portion 34 and the movable portion 36 that form the protruding block 32 is not particularly limited,
Any hard material such as synthetic resin, highly elastic rubber, or metal such as aluminum alloy can be used, but the corrosion resistance to the enclosed fluid should be considered.

Then, in the projecting block 32 having such a structure, it is inserted through the outer tubular metal fitting 12 in a state where the outer peripheral surface of the fixing portion 34 is in contact with the inner peripheral surface of the outer tubular metal fitting 12. The fixing portion 34 is supported by being fixed to the outer tubular fitting 12 by the fixing bolt 40. That is, the protrusion block 32 forms an action protrusion that protrudes in the fluid chamber 30 from the outer tubular metal fitting 12 side toward the inner tubular metal fitting 10 side at a predetermined height in the mount radial direction that is the vibration input direction. Further, under such a mounted state, the fixed portion 34 is fixed to the outer tubular metal fitting 12, while the movable portion 36 is connected to the fixed portion 34 via the connecting rubber elastic body 38. , Is connected and supported so as to be relatively displaceable in the vibration input direction.

In addition, the mounting portion of the fixing bolt 40 in the outer cylinder metal fitting 12,
The recess 42 is formed so as to be recessed inward in the radial direction, and the head portion of the fixing bolt 40 can be housed in the recess 42. When mounting the 12 on the engine unit side, the assembling property is secured by press-fitting into the predetermined mounting hole.

That is, by disposing such a protruding block 32 in the fluid chamber 30, the mount 16 as shown in FIG.
In the mounted state of, a predetermined thickness (gap): t between the protruding end surface (inner peripheral surface) of the protruding block 32 and the inner surface (bottom surface of the pocket portion 22) of the fluid chamber 30 in the vibration input direction. On the other hand, a vibration acting portion 44 is formed which spreads in a direction substantially perpendicular thereto with a predetermined area. Then, in the vibration acting portion 44, when the vibration is input between the inner and outer cylindrical metal fittings 10 and 12, the inner dimension of the fluid chamber 30 in the vibration input direction is changed (increased or decreased), so that the thickness thereof is: Since t changes, the driving force is applied to the fluid existing in the vibration acting portion 44, and the repeated flow of the fluid is generated therein.

Therefore, by adjusting the thickness t of the vibration acting portion 44 and the size (width) thereof to tune the resonance frequency of the fluid flowing inside the vibrating portion 44, It is possible to effectively reduce the mount dynamic spring constant particularly at the time of vibration input in the high frequency range based on the resonance action of the fluid that flows inside.

It should be noted that, in order to sufficiently exhibit the desired low dynamic spring effect based on the resonance action of the fluid that is caused to flow in the vibration action portion 44, in the normal engine mount, the vibration action portion is used.
The thickness of 44: t is set to be 1 to 16 mm, preferably 2 to 10 mm, and the area of the vibration acting portion 44, that is, the area of the protruding end surface of the protruding block 32 facing the inner surface of the fluid chamber 30, It is desirable to set it to 400 mm ² or more, preferably 800 mm ² or more.

Furthermore, there, the engine mount as described above
In the case of 16, the protruding block 32 is, as described above,
It has a single vibration system composed of a fixed portion 34 and a movable portion 36 connected by a connecting rubber elastic body 38, and by using such a protruding block 32, it is shown in FIG. As you can see, to higher frequencies,
Thus, a very characteristic frequency characteristic of anti-vibration performance, in which a good low dynamic spring effect can be advantageously exhibited, is exhibited. Incidentally, in FIG. 4, as a result of measuring the frequency characteristic of the same vibration isolation performance, the engine mount described in the above-mentioned Japanese Patent Application No. 63-152961 in which the protruding block is formed of a single hard material is measured. Is also shown as a comparative example.

By the way, for the details of the action and the principle of reducing the dynamic spring constant to a higher frequency range,
Although not fully clarified yet, in the protruding block 32, the displacement of the movable portion 36 in the fluid chamber 30 can be allowed based on the elastic deformation of the connecting rubber elastic body 38. When the vibration is input between the inner and outer cylindrical metal fittings 10 and 12, the input vibration or the flow of the fluid caused in the fluid chamber 30 is used as a driving force to cause the movable portion 36 to input the vibration in the fluid chamber 30. It is thought that it can be displaced (vibrated) in the direction. Also, due to the displacement of the movable portion 36, the repeated flow of the fluid in the vibration acting portion 44 causes
In addition to what is caused by the wavy deformation of the rubber elastic body 14 that forms the wall of 30, the effective dynamic spring based on the resonance action of the fluid can be used at a higher frequency. It is estimated that it will be possible to reach the region.

From this theory and also from the results of experiments conducted by the present inventor, the frequency range in which the low dynamic spring is achieved depends on the spring constant of the connecting rubber elastic body 38 and the mass of the movable portion 36. By adjusting the natural frequency of the part 36, it is possible to tune appropriately, and thereby 50
It has been confirmed that a low dynamic spring in a high frequency range of 0 Hz or higher can be advantageously achieved.

Therefore, in the engine mount 16 having such a structure, the low dynamic spring effect due to the resonance action of the fluid generated in the vibration acting portion 44 is effective even when the vibration input in a wider high frequency range is performed. As a result, the vibration transmissibility for input vibration in a wider high frequency range can be advantageously reduced, and the quietness and riding comfort in the vehicle can be effectively improved. is there.

In addition, in the engine mount 16, the relative displacement amount of the inner and outer tubular metal fittings 10 and 12 when an excessive vibration load is input is determined by the protrusion block 32.
Of the engine unit can be effectively regulated, and excessive deformation of the rubber elastic body 14 can be regulated, whereby the mount durability can be advantageously improved. It also has such an advantage.

Although one embodiment of the present invention has been described in detail above, this is a literal example, and the present invention should not be construed as being limited to such a specific example.

For example, the specific structure of the protruding block 32 arranged in the fluid chamber 30, that is, the shape of the fixed portion 34, the movable portion 36, and the connecting rubber elastic body 38, etc., can be appropriately selected. Incidentally, FIG. 5 shows an engine mount 48 according to the present invention, which is provided with a protruding block 46 having a shape different from that of the above embodiment. In addition, in this figure, in order to facilitate the understanding thereof, the members having the same structures as those in the above-described embodiment are designated by the same reference numerals.

Further, in the above-mentioned embodiment, the structure having only the single fluid chamber 30 is shown, but in the present invention, in addition,
Those equipped with two or more fluid chambers, or Japanese Patent Publication No. 52
As disclosed in Japanese Patent Application Laid-Open No. 16554 and Japanese Patent Application Laid-Open No. 63-289349, such a sub chamber that is connected to the fluid chamber 30 through an orifice passage and causes a relative internal pressure change at the time of vibration input. It can also be advantageously applied to a mount device or the like having a liquid chamber and having a structure capable of exhibiting a high damping effect on input vibration in a low frequency range based on the resonance action of fluid through the orifice passage. Of course.

In addition, the present invention can be favorably applied to not only the engine mount for automobiles as illustrated but also a mounting device for suspension bushes and various devices other than automobiles.

In addition, although not listed one by one, the present invention can be implemented in a mode in which various alterations, modifications, improvements, etc. are added based on the knowledge of those skilled in the art. It goes without saying that all of them are included in the scope of the present invention without departing from the spirit.

(Effect of the Invention) As is clear from the above description, in the fluid-filled cylindrical mount device having the structure according to the present invention, the low pressure exerted based on the flow of the fluid generated in the vibration acting portion is exerted. The dynamic spring effect, even for input vibrations on the higher frequency side,
Therefore, it is possible to effectively exhibit a cylindrical mounting device that can exhibit excellent vibration damping performance over a wider vibration frequency range of a high frequency range.

Further, in particular, in such a fluid-filled tubular mount device, the vibration action portion (gap) is not only between the vibration action portion (gap) and the inner tubular metal fitting portion, but also the rubber elastic body forming the action protrusion and the wall portion of the fluid chamber. In addition to being formed between the surfaces facing each other in the vibration input direction, the rubber elastic body forming the wall portion of the fluid chamber is relatively easily deformable by the lightening portion, so that the vibration input At the same time, a wavy deformation is caused in the rubber elastic body, and the repeated flow of the fluid in the vibration action gap is extremely efficiently induced, whereby
As described above, the low dynamic spring effect in the high frequency range can be more advantageously exhibited.

[Brief description of drawings]

FIG. 1 is a transverse sectional view showing a specific example of the present invention applied to an automobile engine mount, and FIG. 2 is a II-II sectional view in FIG. FIG. 3 is a transverse sectional view showing a mounted state of the engine mount shown in FIG. Furthermore, FIG. 4 is a graph showing experimental data obtained by measuring the frequency characteristics of the vibration isolation performance of the engine mount having the structure shown in FIG. 1 together with the comparative example. FIG. 5 is a cross-sectional view corresponding to FIG. 1, showing another concrete example of the present invention applied to an automobile engine mount. 10: Inner cylinder metal fitting, 12: Outer cylinder metal fitting 14: Rubber elastic body 16,48: Engine mount 30: Fluid chamber 32, 46: Projection block 34: Fixed part, 36: Movable part 38: Connection rubber elastic body, 40: Fixing bolt 44: Vibration acting part

Claims (1)

[Scope of utility model registration request] 1. An inner cylindrical metal member and an outer cylindrical metal member, which are concentrically or eccentrically arranged at a predetermined distance in a radial direction, are elastically connected by a rubber elastic body interposed therebetween. Along with the rubber elastic body, a pocket portion that opens on the outer peripheral surface of the rubber elastic body is closed by the outer tubular metal fitting, and a predetermined incompressible fluid is enclosed in the fluid chamber into which vibration to be isolated is input. And a substantially W-shaped shape of the pocket portion that protrudes from the outer tubular metal fitting side toward the inner tubular metal fitting side to form the fluid chamber inner surface in the vibration input direction inside the fluid chamber. In the fluid-filled tubular mount device, which is provided with an action protrusion that forms a vibration action portion with a predetermined gap from the bottom face of the rubber elastic member, Penetrates the body in the axial direction and extends in the circumferential direction for approximately half And the bottom walls on both sides in the circumferential direction of the pocket portion are elastic wall portions that can be elastically deformed, while the action protrusion is provided in the fluid chamber while the mount device is mounted. And the vibration acting portion between the bottom surface of the pocket portion and the bottom surface of the pocket portion are arranged so as to form a gap of 1 to 16 mm and substantially over the entire surface of the elastic wall portion. Mounting of a mounting device fixed to the fixed part made of a hard material and connected to the fixing part via a connecting rubber elastic body so as to be relatively displaceable in the vibration input direction between the inner and outer tubular metal fittings. And a movable part made of a hard material and having a substantially W-shaped facing surface corresponding to the shape of a rubber elastic body that gives the bottom surface of the pocket portion under the state. .