KR102440671B1 - Semi active engine mount for vehicle - Google Patents

Abstract

The present invention relates to a semi-active engine mount for a vehicle capable of exhibiting dynamic characteristics that vary according to the driving road surface condition of the vehicle, and is linked to a shock absorber of a suspension system to control the flow rate of fluid movement between the shock absorber and the mount liquid chamber to control the driving road surface condition Accordingly, an object of the present invention is to provide a semi-active engine mount for a vehicle that can increase or decrease a mount dynamic stiffness value.

Description

Semi active engine mount for vehicle}

The present invention relates to a semi-active engine mount for a vehicle, and more particularly, to a semi-active engine mount for a vehicle capable of exhibiting dynamic characteristics that vary according to a driving road surface condition of a vehicle.

In general, the engine mount prevents the vibration of the engine from being transmitted to the vehicle body, insulates the vibration mode of the vehicle, and controls the movement of the engine.

The main performance goal of these engine mounts is to make them statically strong to minimize engine movement, and dynamically to insulate high-frequency vibrations by making them flexible.

Engine mounts made of rubber usually exhibit excellent absorption and damping performance for high-frequency micro-amplitude vibrations among vibrations generated during engine operation, but are very vulnerable to low-frequency large displacement vibrations. There is a disadvantage that all of the above vibrations cannot be satisfied.

Accordingly, a fluid-filled engine mount capable of absorbing and damping vibrations over a wide range including high-frequency micro-amplitude vibration and low-frequency large displacement vibration input to the engine mount according to the operation of the engine is used.

In particular, in recent years, in order to improve fuel efficiency of a vehicle, active engine mounts and semi-active engine mounts capable of preventing NVH (Noise, Vibration, Harshness) performance degradation have been used.

The conventional semi-active engine mount has a separate actuator to open and close a separate bypass flow path for the enclosed internal fluid, so that the rigidity value can be increased or decreased by adjusting the moving flow rate of the fluid inside the mount. R&H (Riding & Handling) improves the NVH performance (reducing the mount stiffness value) by smoothing the movement of fluid during idling and driving on a smooth road surface. ) to improve performance (increase the mount stiffness value).

However, this conventional semi-active engine mount has a complicated structure as it is configured to open and close the bypass flow path using a separate actuator made of a solenoid valve and wiring, and there is a concern of leakage of the enclosed fluid due to such a complicated structure. There is also a problem in that the material cost increases due to the addition of parts.

Korean Patent Publication No. 10-2013-0003749 (January 09, 2013)

The present invention has been devised in view of the above, and by controlling the flow rate of fluid movement between the shock absorber and the mount liquid chamber in connection with the shock absorber of the suspension, the mount dynamic stiffness value is increased or decreased according to the driving road surface conditions. It aims to provide a semi-active engine mount for vehicles that can be controlled.

Accordingly, in the present invention, an insulator made of an elastic material having a core therein; a case surrounding the outer periphery of the insulator to form a mount liquid chamber under the insulator; a closing plate fixed to the bottom surface of the case to seal the mount liquid chamber; It provides a semi-active engine mount for a vehicle, characterized in that it comprises a; fluid flow passage connected to the fluid movement between the mount liquid chamber and the shock absorber.

According to an embodiment of the present invention, in the semi-active engine mount, a stopper for limiting the displacement of the core according to the elastic deformation of the insulator is provided at the lower end of the core, and the fluid is airtightly assembled to the closing plate in the fluid flow path. A fluid filling port is provided for initial fluid filling before the inlet port and the shock absorber are operated.

According to the semi-active engine mount of the present invention as described above, the following effects can be obtained.

1. When the engine movement is relatively small, such as when the engine is idling or when driving on a smooth road, the amount of fluid supplied from the shock absorber to the mount liquid is not or very small, so it has a relatively low mount dynamic stiffness depending on the vibration insulation performance of the insulator. , which has the advantage of improving NVH performance as a result.

2. When the engine movement is relatively large, such as when driving on a rough road, since the amount of fluid supplied from the shock absorber to the mount liquid increases, the mount has high mount dynamic stiffness according to the increased amount of fluid, and as a result, the engine movement is further increased. It has the advantage of being able to effectively control it and improving R&H performance.

3. It is possible to omit the configuration of the actuator for fluid bypass in the existing semi-active engine mount, which simplifies the operation structure, reduces the number of parts and reduces material and investment costs, and concerns about fluid leakage due to the complex structure. can be removed to improve durability.

1 is an exploded perspective view showing a semi-active engine mount according to an embodiment of the present invention;
2 is a cross-sectional view showing a semi-active engine mount according to an embodiment of the present invention;
3 and 4 are views showing an interlocking structure of a semi-active engine mount and a shock absorber according to an embodiment of the present invention;

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

As shown in FIGS. 1 to 4 , the semi-active engine mount of the present invention has a structure capable of increasing or decreasing a mount stiffness value, that is, a mount dynamic stiffness according to a state for each road surface condition on which the vehicle is driven.

To this end, the semi-active engine mount is largely configured to include an insulator 10 , a case 20 , a closing plate 30 , a fluid inlet port 40 , and the like.

The insulator 10 is made of a material having elasticity (eg, rubber, etc.), integrally provided with a core 12 coupled to the engine side, and has a substantially cylindrical shape coupled to the outer periphery of the lower portion of the vehicle body. The case 20 is integrally coupled. The insulator 10 is integrally molded with the core 12 and the case 20 by, for example, vulcanization or the like.

Accordingly, it is possible to reduce vibration transmitted from the engine side to the vehicle body side by the dynamic characteristics exhibited by the insulator 10 .

The core 12 is provided in a form inserted into the center of the insulator 10 , and at this time, the upper part thereof is surrounded by the insulator 10 in a state in which the upper part is exposed upward of the insulator 10 .

The case 20 is fixed by attaching the lower end of the insulator 10 to the upper side of the inner circumferential surface thereof, and the edge portion (the portion attached to the inner circumferential surface of the case) among the lower portions of the insulator 10 is the lower portion of the inner circumferential surface of the case 20 . It extends to the side and is disposed adjacent to the finishing plate 30 .

In addition, the case 20 forms a mount liquid chamber 22 for fluid inflow as a space surrounded by the lower side of the case 20 under the core 12 .

The mount liquid chamber 22 is closed to be sealed by a plate-shaped closing plate 30 fixed to the bottom surface of the case 20, and the central portion of the closing plate 30 flows into the mount liquid chamber 22 or 22), the fluid inlet port 40 for the inlet and outlet of the fluid discharged from the fluid outlet is provided with a coupling port 32 assembled in a hermetically inserted form.

The fluid inlet port 40 is movably connected to the shock absorber 70 through the fluid flow passage 42 , and through this fluid inlet port 40 , the external fluid, that is, the inside of the shock absorber 70 . The fluid may be moved and supplied to the mount liquid chamber 22 .

As is known, a shock absorber is a vehicle suspension device installed between a wheel and a vehicle body to absorb road shock and vibration, and receives a load transmitted from the road according to the condition of the driving road surface. At this time, the input road load The displacement amount of the shock absorber is determined according to the size of the shock absorber, and the lower fluid of the shock absorber passes through the orifice and moves to the upper part of the shock absorber according to the displacement amount.

The fluid flow path 42 is connected to a port separately provided on the upper side of the shock absorber 70 so that the internal fluid that has moved into the upper space of the shock absorber 70 through the orifice 74 can be discharged and flowed.

And, the fluid flow path 42 is connected as a vacuum flow path between the mount liquid chamber 22 and the shock absorber 70, that is, the shock absorber 70 and the fluid flow path 42 and the fluid inlet port 40 are The connection is configured to maintain a vacuum state, and at this time, the internal volume of the shock absorber 70 is set to be relatively large in consideration of the volume of the insulator 10 and the volume of the fluid flow passage 42 .

Accordingly, when the road load transmitted to the shock absorber 70 increases, the internal pressure increase effect of the shock absorber 70, the fluid flow passage 42, and the fluid inlet port 40 occurs, and as a result, the orifice 74 The internal fluid that has passed through and moved to the upper space of the shock absorber 70 is moved to the mount liquid chamber 22 and increases the internal pressure of the mount liquid chamber 22, thereby increasing the rigidity value of the engine mount (ie, mount dynamic rigidity). effect can be obtained.

In general, the damping value (damping force) of the shock absorber is determined (changed according to orifice tuning) according to the flow degree (flow rate and flow rate) of the lower fluid of the shock absorber passing through the orifice and moving to the upper space, so the fluid flow path 42 The shock absorber performance is not affected even if it is separately configured and connected between the shock absorber and the engine mount.

In addition, since the internal fluid of the shock absorber 70 is an incompressible fluid, the internal pressure of the mount liquid chamber 22 is increased or decreased according to the displacement (movement) of the shock absorber 70 according to the road surface condition and load.

At this time, the fluid flow passage 42 is pre-filled with a fluid so that the pressure fluctuation of the mount liquid chamber 22 can occur immediately according to the displacement of the shock absorber 70 .

To this end, a fluid filling port 44 for initial fluid filling is provided on one side of the fluid flow passage 42, and the fluid flow passage through the fluid filling port 44 before the operation of the shock absorber 70 and the engine mount ( 42) is filled with the same fluid as the fluid of the shock absorber (70).

A stopper 50 for limiting displacement and behavior of the core 12 and the insulator 10 according to elastic deformation of the insulator 10 is provided at the lower end of the insulator 10, and the stopper 50 ) is supported to be fixed to the lower end of the core 12 through a bolt member 52 fastened to the core 12 .

The stopper 50 limits the behavior of the insulator 10 being excessively deformed in the axial direction (which is the axial direction of the core) when elastic deformation of the insulator 10 occurs due to vibration transmitted from the engine side to the vehicle body side. .

The stopper 50 is configured to support the lower portion of the insulator 10 attached to the upper portion of the inner circumferential surface of the case 20 from below, and for this purpose, the inner step difference of the case 20 when the insulator 10 is elastically deformed. It is formed to be hookable in a laminated form on the part 24 .

In addition, unexplained reference numeral 34 denotes a sealing member 34 for sealing the mount liquid chamber 22, and reference numeral 60 is fixedly coupled to the upper side of the core 12 exposed above the insulator 10 and the insulator ( 10) is a plate-shaped dust cover 60 that covers the upper side.

The operation method of the semi-active engine mount configured in this way can be largely divided into two types as follows.

First, when the engine movement is relatively small due to the vehicle being in an engine idling state or driving on a soft road surface, as shown in FIG. 3, since the amount of operating displacement of the shock absorber 70 is not large, the 22), the amount of fluid moved to or is insignificant, and thus vibration damping force due to a change in fluid pressure in the mount liquid chamber 22 does not occur, so the mount rigidity value is determined purely according to the material characteristics of the insulator 10 . Since the rubber material characteristic of the insulator 10 is basically set in consideration of the NVH performance, it has a relatively low stiffness value, and as a result, the effect of improving the NVH performance is secured.

On the other hand, when the engine movement is relatively large due to the vehicle traveling on a rough road surface, as shown in FIG. 4 , since the amount of operating displacement of the shock absorber 70 is relatively large, a large amount of fluid discharged from the shock absorber 70 is The fluid flows into the mount liquid chamber 22 through the fluid inlet port 40, and as the pressure in the mount liquid chamber 22 increases, the mount stiffness value increases, so that the engine movement due to the rough road surface can be more effectively controlled to isolate vibration. As a result, the effect of improving R&H performance is secured.

At this time, the mount dynamic stiffness value is determined by the stiffness value according to the material characteristics of the insulator 10 and the stiffness value increased by the fluid flowing into the mount liquid chamber 22 from the shock absorber 70 .

Here, the fluid of the shock absorber 70 moved to the mount liquid chamber 22 is recovered to the shock absorber 70 according to the operating displacement amount of the shock absorber 70 .

The semi-active engine mount that operates in this way is configured to use the shock absorber fluid of the suspension that is basically provided in the vehicle, so it has a simpler structure than the conventional semi-active engine mount that employs an actuator for fluid bypass, and is equivalent to the conventional mount It has the advantage of being able to perform a level function, reducing material cost and investment cost due to the deletion of the actuator compared to the prior art, and improving durability by eliminating the concern of fluid leakage due to a complex structure.

In addition, since the semi-active engine mount is configured to exhibit variable dynamic characteristics according to driving road conditions, there is an advantage in that the mount dynamic characteristic value is linearly changed according to the increase/decrease in displacement (momentum) of the shock absorber.

In the case of a conventional mount employing the actuator, it is impossible to secure linear dynamic characteristics because the mount dynamic characteristics are changed through on/off control of the solenoid valve.

As the embodiment of the present invention has been described in detail above, the scope of the present invention is not limited to the above-described embodiment, and various modifications and Improvements are also included in the scope of the present invention.

10: insulator
12: core
20: case
22: mount axil
24: step part
30: finish plate
32: coupler
34: sealing member
40: fluid inlet port
42: fluid flow path
44: fluid filling port
50: stopper
52: bolt member
60: dust cover
70: shock absorber
74: orifice

Claims (4)

an insulator made of an elastic material having a core therein;
a case surrounding the outer periphery of the insulator to form a mount liquid chamber under the insulator;
a closing plate fixed to the bottom surface of the case to seal the mount liquid chamber;
It includes; a fluid flow path that is fluidly movably connected between the mount liquid chamber and the shock absorber.
When the road load transmitted to the shock absorber increases, the internal fluid of the shock absorber is moved to the mount liquid chamber to increase the internal pressure of the mount liquid chamber, and the fluid of the shock absorber moved to the mount liquid chamber is proportional to the operating displacement of the shock absorber. Semi-active engine mount for a vehicle, characterized in that it is recovered by the shock absorber.
The method according to claim 1,
A semi-active engine mount for a vehicle, characterized in that the stopper for limiting the displacement of the core according to the elastic deformation of the insulator is provided at the lower end of the core.
The method according to claim 1,
The fluid flow passage semi-active engine mount for a vehicle, characterized in that it has a fluid inlet port airtightly assembled to the closing plate.
The method according to claim 1,
The fluid flow path is a semi-active engine mount for a vehicle, characterized in that provided with a fluid filling port for initial fluid filling before the operation of the shock absorber.

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