KR20060071211A - A hydraulic engine mount - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid enclosed engine mount, wherein a hydrobush with fluid is enclosed in a center boss provides a non-linear damping characteristic of rubber and hydrobush fixed to the center boss against horizontal vibration, thereby providing horizontal damping. In particular, it is possible to effectively attenuate vibrations, particularly large displacements.

Description

Fluid-mounted engine mounts {A hydraulic engine mount}

1 is a structural diagram showing the internal structure of a typical fluid-filled engine mount,

FIG. 2 (a) is a graph showing the relationship between dynamic stiffness and frequency in the vertical direction of the engine mount shown in FIG. 1;

FIG. 2 (b) is a graph showing the relationship between dynamic stiffness and frequency in the horizontal direction of the engine mount shown in FIG. 1;

3 is a structural diagram showing the internal structure of the fluid-enclosed engine mount according to a preferred embodiment of the present invention,

4 is a plan view of FIG.

Figure 5 (a) is a graph showing the relationship between the dynamic stiffness-frequency in the vertical direction of the fluid-filled engine mount according to the present invention,

Figure 5 (b) is a graph showing the relationship between the dynamic stiffness-frequency in the horizontal direction of the fluid-filled engine mount according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: center boss 20: rubber

30: housing 40: movable plate member

50: upper chamber 60: lower chamber                 

70: lower boss 100: hydrobush

101: pipe 102-105: rubber projection

110: case

The present invention relates to a fluid enclosed engine mount, and more particularly, to a fluid enclosed engine mount capable of effectively attenuating horizontal vibration.

In general, a fluid-filled engine mount is installed between an engine of a vehicle and a vehicle body to control vibration and shock of the engine to prevent transmission of vibration and impact to the vehicle body.

Such a fluid-enclosed engine mount is bellows-shaped by a center boss 1 coupled to the engine and a rubber 2 and a housing 3 fixed to the center boss 1, as shown in FIG. 1. It forms a chamber therein, by separating the upper chamber (5) and the lower chamber (6) by the movable plate member 4 is made of a structure in which a working fluid having a viscosity is sealed, the lower portion of the housing (3) The lower boss 7 is coupled to the vehicle body is installed.

 Here, the movable plate member 4 has an annular passage 4a formed at an edge thereof, and the upper and lower gaps 4b, which allow fluid to flow between the upper chamber 5 and the lower chamber 6. 4c).

In the fluid enclosed engine mount configured as described above, when the vibration is transmitted from the engine, the rubber 2 is deformed and the volume of the upper chamber 5 is changed, and the amount of fluid corresponding to the changed volume is the upper chamber 5. It moves from the lower chamber 6 to the lower chamber 6, which flows along the annular passage 4a or between the gaps 4b and 4c of the movable plate member 4.

If the amount of fluid corresponding to the deformed volume of the rubber 2 is greater than the movement amount of the gaps 4b and 4c of the movable plate member 4, that is, if the low frequency large displacement vibration is transmitted, the fluid is between the movable plate member 4. Flows along the annular passage 4a without passing through the gaps 4b and 4c, and at this time, the fluid in the annular passage 4a resonates at a specific frequency (see f in FIG. This will occur.

This damping force of the fluid-enclosed engine mount is not perfect but generally has a property proportional to the magnitude of the displacement of the vibration, and thus is very effective in suppressing vibration (see FIG. 2A).

By the way, in the fluid-sealed engine mount as described above, the fluid acts on the vibration input in the vertical direction and can effectively attenuate it. b)), there is a problem in that the horizontal vibration, in particular, large displacement vibration is not effectively attenuated.

Accordingly, the present invention has been made to solve the problems of the prior art as described above, and an object thereof is to provide a fluid-filled engine mount that can effectively attenuate the horizontal vibration.

Fluid-mounted engine mount according to the present invention for achieving the above object, the rubber is installed in the housing and the center boss is fixed to the rubber, the fluid is filled therein, and further comprising a hydrobush coupled with the center boss It further comprises.

In addition, the present invention, the outer periphery of the center boss is coupled to the inner circumference of the hydrobush, but the gap between the inner circumference of the hydrobush and the outer circumference of the center boss is made to have a clearance as much as a predetermined distance, Another feature is that the rubber protrusion is formed on the inner circumference.

The present invention is also characterized in that the hydrobush is supported on the housing.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a structural diagram showing the internal structure of the fluid-enclosed engine mount according to a preferred embodiment of the present invention, Figure 4 is a plan view of Figure 3, as can be seen with reference to the same figure, the fluid-filled engine mount according to the present invention The upper chamber 50 and the lower chamber 60 are formed by the center boss 10 coupled to the engine, the rubber 20 fixed to the center boss 10, and the movable plate member 40 therein. It is configured to include a formed housing 30 and the lower boss 70 is installed in the lower portion of the housing 30 and coupled to the vehicle body.                     

Herein, the movable plate member 40 has an annular passage 41 formed at an edge thereof, and the upper and lower gaps 42 and 42 allow the fluid to flow between the upper chamber 50 and the lower chamber 60. 43).

In addition, in the present invention, a hydro bush 100 is fixed to the upper portion of the housing 30 via a cylindrical case 110.

The hydrobush 100 is a well-known liquid-enclosed bush in which a viscous working fluid is filled and a fluid passage through which the fluid passes is formed. The pipe 101 is provided, and several rubber protrusions 102-105 are formed in the inner periphery.

The hydrobush 100 is installed so that the center boss 10 penetrates the inner circumference thereof, and has a clearance as much as a set distance between the rubber protrusions 102 to 105 of the inner circumference and the outer circumference of the center boss 10. .

In addition, the case 110 to which the hydrobush 100 is fixed is configured to receive and secure the upper end of the housing 30 therein while being coupled to the outer circumferential surface of the housing 30. For example, the case 110 may be fixed to the housing 30 by welding, or the case 110 may be integrally formed with the housing 30.

With reference to the accompanying drawings will now be described in detail the effect of the present invention configured as described above.

In a state where the center boss 10 is coupled to the engine, when the engine vibrates, the rubber 20 is deformed to generate relative displacement between the rubber 20, the housing 30, and the case 110.

This relative displacement corresponds to the vibration input in the vertical and horizontal directions, but when the engine vibrates in the vertical direction, since the contact between the center boss 10 and the hydrobush 100 does not occur, the general fluid-filled engine mount It works the same as.

That is, the fluid in the upper chamber 50 surrounded by the rubber 20 passes through the annular passage 41 of the movable plate member 40 and / or the gaps 42, 43 of the movable plate member 40 depending on the amplitude. While moving to the lower chamber 60, as shown in FIG. 5 (a), nonlinear dynamic characteristics that vary with amplitude and frequency appear. (For reference, the attenuation width is greatest at the frequency f1 in the vertical direction.)

If the engine vibrates in the horizontal direction, the rubber 20 causes shear deformation in the lateral direction, which causes the center boss 10 to move in the horizontal direction.

At this time, when the distance that the center boss 10 is moved is shorter than the clearance between the center boss 10 and the rubber protrusions 102 to 105 of the inner circumference of the hydrobush 100 or in the elastic region of the rubber protrusions 102 to 105. , The shear property of only the rubber 20, that is, the characteristics such as the graph shown as "small X" in Figure 5 (b).

However, the horizontal movement distance of the center boss 10 is greater than the clearance between the center boss 10 and the rubber protrusions 102 to 105 of the inner periphery of the hydrobush 100 and larger than the elastic region of the rubber protrusions 102 to 105. When the center boss 10 pushes the rubber protrusions 102 to 105, the hydro bush 100 generates relative movement with respect to the case 110 and the housing 30 such that the fluid therein moves the fluid passage. This causes large damping at a constant frequency.

That is, it shows the same characteristics as the graph shown in "large X" in Figure 5 (b), referring to the graph it can be seen that the attenuation width is the largest at a specific frequency f2.

That is, the characteristics of the fluid-sealed engine mount of the present invention are summarized below with reference to the graphs of FIGS. 5A and 5B.

A. When the amplitude of the input vibration in the vertical direction is large (fluid movement amount due to the gap between the upper and lower portions of the movable plate member <fluid flow amount due to the amplitude of the input vibration), it has the maximum attenuation at the frequency f1. The attenuation is large in the frequency domain (see "large X" in Fig. 5A).

B. When the amplitude of the input vibration in the vertical direction is small (the amount of fluid movement due to the gap between the upper and lower portions of the movable plate member> the amount of fluid flow due to the amplitude of the input vibration), the linear damping increases gradually with increasing frequency. In general, small dynamic stiffness is shown in the entire frequency domain (see "small X" in FIG. 5 (a)).

C. When the amplitude of the horizontal input oscillation is small (when oscillating within the range of play between the rubber bump and center boss of the hydrobush and the elastic region of the rubber bump), a generally constant (linearly increasing slightly) dynamic It shows the stiffness characteristic (see "small X" in Figure 5 (b)).

D. When the amplitude of the input vibration in the horizontal direction is large (when the amplitude of the vibration becomes larger than the elastic region of the rubber protrusion and the inside of the hydrobush deforms), it has the maximum attenuation at the frequency f2. Attenuation is large in the frequency domain (see "large X" in Fig. 5B).

The present invention is described above by illustrating specific embodiments, but the present invention is not limited to the above embodiments. Those skilled in the art can easily make various changes and modifications to the present invention, and it should be noted that such variations or modifications are included within the scope of the present invention as long as the features of the present invention are used.

Particularly, in the above-described embodiment of the present invention, the case where the clearance between the rubber protrusion and the center boss of the hydrobush is set as an example is described. It is to be noted that such modifications or modifications are also included in the scope of the present invention by using the features of the present invention, since the action can effectively damp the horizontal vibration.

As described above, the present invention provides a non-linear damping characteristic of the rubber and the hydrobush fixed to the center boss against horizontal vibration by installing a hydrobush in which the fluid is enclosed in the center boss. The vibration of large displacement can be effectively attenuated.

Claims (5)

In a fluid-sealed engine mount in which a rubber is installed in the housing and a center boss is fixed to the rubber, Fluid-filled engine mount, characterized in that it further comprises a hydrobush is filled with a fluid and coupled to the center boss. The fluid enclosed engine of claim 1, wherein an outer circumference of the center boss is inserted into and coupled to an inner circumference of the hydrobush, wherein the fluid enclosed engine has a clearance equal to a set distance between the inner circumference of the hydrobush and the outer circumference of the center boss. Mount. The fluid-filled engine mount of claim 2, wherein a rubber protrusion is formed on an inner circumference of the hydrobush. The fluid-sealed engine mount according to any one of claims 1 to 3, wherein the hydrobush is supported on the housing. The fluid-sealed engine mount according to claim 4, wherein the hydrobush is supported on the housing by inserting and fixing the hydrobush in a cylindrical case and binding the case to the housing.

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