阅读说明：本技术 用于车辆的可变排气气门组件 (Variable exhaust valve assembly for vehicle ) 是由 李相日 金连洙 李完喆 金镇宇 姜宗和 于 2019-01-07 设计创作，主要内容包括：本发明公开了一种用于车辆的可变排气气门组件,其包括：排气壳体；动力传递装置,其传递旋转动力；轴,其延伸通过所述排气壳体并且与气门联接,以便打开和关闭所述排气壳体；以及热量阻挡单元,其减少所述动力传递装置与所述排气壳体之间的热量传递。所述动力传递装置配置成调节所述气门的打开程度。所述可变排气气门组件通过最小化由废气的较高温度的热量对所述动力传递装置造成的损伤,来改善耐久性,并且减少传递至所述动力传递装置的振动。(The present invention discloses a variable exhaust valve assembly for a vehicle, including: an exhaust housing; a power transmission device that transmits rotational power; a shaft extending through the exhaust housing and coupled with a valve to open and close the exhaust housing; and a heat blocking unit that reduces heat transfer between the power transfer device and the exhaust housing. The power transmission device is configured to adjust an opening degree of the valve. The variable exhaust valve assembly improves durability and reduces vibration transmitted to the power transmission device by minimizing damage to the power transmission device caused by heat of higher temperature of exhaust gas.)

1. A variable exhaust valve assembly for a vehicle, comprising:

an exhaust housing through which exhaust gas flows;

a power transmission device disposed separately from the exhaust housing and configured to transmit rotary power;

a shaft configured to receive rotational power from the power transmission device, the shaft extending through and passing through the exhaust housing and being coupled with a valve provided inside the exhaust housing so as to open and close the exhaust housing according to a rotational position of the shaft; and

a heat blocking unit mounted on the shaft between the power transmission device and the exhaust housing and configured to block heat transfer so as to reduce heat transfer between the power transmission device and the exhaust housing.

2. The variable exhaust valve assembly for a vehicle according to claim 1, wherein the exhaust housing is provided with a through hole through which a shaft passes;

the heat blocking unit has a cover unit formed to cover a peripheral portion of the through hole in the exhaust housing in a state of being mounted on the shaft.

3. The variable exhaust valve assembly for a vehicle according to claim 2, further comprising:

a bearing member disposed to close the through hole and configured to surround the shaft so as to support rotational movement of the shaft.

4. The variable exhaust valve assembly for a vehicle according to claim 3, wherein the heat blocking unit includes an elastic member that is provided in contact with one end of a bearing member inside the cover unit and is configured to press the bearing member toward the through hole;

the shaft is provided with a support protrusion located at the other end of the bearing member and protruding in a circumferential direction such that the bearing member is seated on the support protrusion to restrict movement toward the exhaust housing.

5. The variable exhaust valve assembly for a vehicle according to claim 2, wherein the power transmission means is provided with a rotary shaft configured to transmit rotary power;

the heat blocking unit is provided with a connection part extending from the cover unit and coupled to the rotation shaft, the connection part being provided with a mounting groove recessed such that the shaft is inserted thereinto.

6. The variable exhaust valve assembly for a vehicle according to claim 5, wherein the connection portion of the heat blocking unit is provided with a first aperture;

the shaft is provided with a second opening hole corresponding to the first opening hole in a state where the shaft is inserted into the mounting groove in the connection part;

a fastening pin is inserted into the first and second holes such that the heat blocking unit and the shaft are connected to each other.

7. The variable exhaust valve assembly for a vehicle according to claim 6, wherein the first aperture is formed to have a size larger or smaller than the second aperture.

8. The variable exhaust valve assembly for a vehicle according to claim 5, wherein the heat blocking unit is provided with a heat insulating unit that is installed in the connection portion so as to be located between the power transmission device and the cover unit, and that is configured to radiate and radiate heat transmitted through the exhaust housing and the cover unit.

9. The variable exhaust valve assembly for a vehicle according to claim 5, wherein the rotary shaft is provided at an end portion corresponding to the connecting portion with an insertion protrusion or an insertion groove;

the connection portion is provided with an insertion groove or an insertion protrusion that matches the rotation shaft.

10. The variable exhaust valve assembly for a vehicle according to claim 1, wherein the power transmission device includes:

a housing in which a motor unit configured to generate rotational power is accommodated;

a rotating shaft provided inside the housing and configured to transmit rotary power transmitted from the motor unit to the shaft; and

a vibration absorbing unit disposed inside the housing and configured to rotatably support the rotation shaft from the housing and absorb vibration.

11. The variable exhaust valve assembly for a vehicle according to claim 10, wherein the vibration absorbing unit includes a worm wheel unit that rotates by receiving rotational power from the motor unit, and a damper unit that is seated on the worm wheel unit and absorbs vibration;

the rotation shaft includes a shaft portion penetrating the worm gear unit and configured to transmit a rotational power to the shaft, and a support portion protruding from the shaft portion to be mounted on the worm gear unit and to be seated on a damper unit.

Technical Field

The present invention relates to a variable exhaust valve assembly for a vehicle that adjusts the flow rate of exhaust gas.

Background

Exhaust gas generated after combustion of fuel in the engine is guided to the outside of the engine through an exhaust manifold, and then the exhaust gas is introduced into a turbocharger to be recirculated or discharged to the outside of the vehicle through an exhaust device.

When the exhaust gas is discharged at a high speed, noise is generated. In order to reduce the generated noise, a muffler is installed to reduce the flow rate of exhaust gas and to reduce the temperature of the exhaust gas.

In addition, in recent years, an exhaust valve has been provided on a path through which exhaust gas is discharged to increase a driver's feeling of driving with the discharged exhaust gas. Such an exhaust valve controls the amount of exhaust gas discharged according to the degree of opening thereof, and reduces or transmits noise according to the degree of opening of the exhaust valve, so as to convey a sporty driving feeling to the driver.

However, the exhaust valve device known in the related art is driven by the motor, and there is a problem in that the motor may be damaged when heat of a higher temperature transferred from exhaust gas is transferred to the motor. In addition, there is a problem in that vibration generated due to the movement of the vehicle and the circulation of exhaust gas is transmitted to the motor, thereby causing damage to the motor.

The foregoing background is provided as background only for the purpose of promoting an understanding of the background of the invention and the foregoing description of the background is not to be construed as an admission that it corresponds to prior art known to those skilled in the art.

Disclosure of Invention

The present invention provides a variable exhaust valve assembly for a vehicle, in which the durability of a motor device for adjusting the degree of opening of a throttle valve is improved and vibration transmitted to the motor device is reduced by minimizing damage to the motor device (e.g., damage caused by heat of a higher temperature).

In particular, the variable exhaust valve assembly according to the present invention includes: an exhaust housing through which exhaust gas flows; a power transmission device disposed separately from the exhaust housing and configured to transmit rotary power; a shaft configured to receive rotational power from the power transmission device, the shaft extending through and passing through the exhaust housing and being coupled with a valve provided inside the exhaust housing so as to open and close the exhaust housing according to a rotational position of the shaft; and a heat blocking unit mounted on the shaft between the power transmission device and the exhaust housing and configured to block heat transfer so as to reduce heat transfer between the power transmission device and the exhaust housing.

The exhaust shell is provided with a through hole through which a shaft passes; the heat blocking unit has a cover unit formed to cover a peripheral portion of the through hole in the exhaust housing in a state of being mounted on the shaft.

The variable exhaust valve assembly further includes a bearing member disposed to close the through hole and configured to surround the shaft so as to support a rotational motion of the shaft.

The heat blocking unit includes an elastic member disposed to contact one end portion of a bearing member inside the cover unit and configured to press the bearing member toward the through hole; the shaft is provided with a support protrusion located at the other end of the bearing member and protruding in a circumferential direction such that the bearing member is seated on the support protrusion to restrict movement toward the exhaust housing.

The power transmission device is provided with a rotating shaft configured to transmit rotational power; the heat blocking unit is provided with a connection part extending from the cover unit and coupled to the rotation shaft, the connection part being provided with a mounting groove recessed such that the shaft is inserted thereinto.

The connecting part of the heat blocking unit is provided with a first opening; the shaft is provided with a second opening hole corresponding to the first opening hole in a state where the shaft is inserted into the mounting groove in the connection part; a fastening pin is inserted into the first and second holes such that the heat blocking unit and the shaft are connected to each other.

Any one of the first and second openings is formed to have a larger size.

The heat blocking unit is provided with a heat insulating unit installed in the connection portion so as to be located between the power transmission device and the cover unit, and configured to radiate and radiate heat transmitted through the exhaust housing and the cover unit.

The rotary shaft is provided with an insertion protrusion or an insertion groove at an end portion corresponding to the connection portion; the connection portion is provided with an insertion groove or an insertion protrusion that matches the rotation shaft.

The power transmission device includes: a housing in which a motor unit configured to generate rotational power is accommodated; a rotating shaft provided inside the housing and configured to transmit rotary power transmitted from the motor unit to the shaft; and a vibration absorbing unit disposed inside the housing and configured to rotatably support the rotation shaft from the housing and absorb vibration.

The vibration absorbing unit includes a worm wheel unit rotated by receiving a rotational power from the motor unit, and a damper unit seated on the worm wheel unit and absorbing vibration; the rotation shaft includes a shaft portion penetrating the worm wheel unit and configured to transmit a rotation power to the shaft, and a support portion protruding from the shaft portion to be mounted on the worm wheel unit and to be seated on a damper unit.

The variable exhaust valve assembly of the vehicle having the above-described structure minimizes damage to the power transmission device (which is used to adjust the opening degree of the valve) caused by the heat of the higher temperature of the exhaust gas, and reduces vibration transmitted to the power transmission device, thereby improving durability of the power transmission device.

Drawings

The above and other aspects, features and advantages of the present invention will be more clearly understood from the following detailed description presented in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a variable exhaust valve assembly for a vehicle according to an embodiment of the present invention;

FIG. 2 is an exploded part view of the variable exhaust valve assembly of FIG. 1;

FIG. 3 is an exploded part view of a power transmission arrangement according to the variable exhaust valve assembly of the vehicle shown in FIG. 1;

FIG. 4 is a cross-sectional view of the variable exhaust valve assembly shown in FIG. 1; and

fig. 5 to 7 are views for explaining the variable exhaust valve assembly shown in fig. 1.

Detailed Description

It should be understood that the term "vehicle" or "vehicular" or other similar terms as used herein generally includes motor vehicles such as passenger automobiles including Sport Utility Vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including a variety of boats, ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from non-petroleum sources). As referred to herein, a hybrid vehicle is a vehicle having two or more power sources, such as both gasoline-powered and electric-powered vehicles.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, values, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, values, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Throughout this specification, unless explicitly described to the contrary, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms "unit," "device," "means," and "module" described in the specification mean a unit for performing at least one of functions and operations, and may be implemented by hardware components or software components, and a combination thereof.

Furthermore, the control logic of the present invention may be embodied as a non-transitory computer readable medium on a computer readable medium containing executable program instructions for execution by a processor, controller, or the like. Examples of computer readable media include, but are not limited to, ROM, RAM, Compact Disc (CD) -ROM, magnetic tape, floppy disk, flash drive, smart card, and optical data storage device. The computer readable medium CAN also be distributed over a Network coupled computer system so that the computer readable medium is stored and executed in a distributed fashion, for example, by a telematics server or Controller Area Network (CAN).

Hereinafter, a variable exhaust valve assembly for a vehicle according to an embodiment of the present invention will be described with reference to the accompanying drawings.

Fig. 1 is a perspective view of a variable exhaust valve assembly for a vehicle according to an embodiment of the present invention, fig. 2 is an exploded part view of the variable exhaust valve assembly of fig. 1, and fig. 3 is an exploded part view of a power transmission apparatus according to the variable exhaust valve assembly shown in fig. 1. Fig. 4 is a sectional view of the variable exhaust valve assembly shown in fig. 1, and fig. 5 to 7 are views for explaining the variable exhaust valve assembly shown in fig. 1.

As shown in fig. 1 and 2, a variable exhaust valve assembly for a vehicle according to the present invention includes: an exhaust housing 100 through which exhaust gas flows, a power transmission device 200, a shaft 300, and a heat blocking unit 400; the power transmission device 200 is disposed separately from the exhaust housing 100 and configured to transmit rotational power; the shaft 300 is configured to receive rotational power from the power transmission device 200, extend through the exhaust housing 100 and through the exhaust housing 100, and couple with a valve 301 provided inside the exhaust housing 100 to open and close the exhaust housing 100 according to the rotational position of the shaft 300; the heat blocking unit 400 is mounted on the shaft 300 between the power transmission device 200 and the exhaust housing 100, and is configured to block heat transfer so as to reduce heat transfer between the power transmission device 200 and the exhaust housing 100.

Here, the exhaust housing 100 may be coupled to an end of the exhaust pipe inside the muffler, wherein the exhaust housing is formed in a cylindrical shape and configured to circulate exhaust gas therein. The shaft 300 configured to receive rotational power from the power transmission device 200 vertically penetrates the exhaust housing 100, and a bearing may be installed in a portion where the shaft 300 vertically penetrates so as to rotatably support the shaft 300. In addition, since the shaft 300 is coupled with the valve 301, the valve 301 rotates together with the shaft 300 in the exhaust housing 100 to open and close the exhaust housing 100, and thus, the flow rate of the exhaust gas is determined according to the opening degree of the valve 301, and the opening degree of the valve 301 is determined according to the rotational position of the valve 301. Here, as for the valve 301, the maximum opening degree of the valve 301 may be limited by a fixing pin P2 protruding to the inside of the exhaust housing 100.

In particular, the shaft 300 is provided with a heat blocking unit 400 disposed between the power transmission device 200 and the exhaust housing 100 to reduce heat transfer from exhaust gas passing through the exhaust housing 100 to the power transmission device 200. In other words, when the shaft 300 penetrates the exhaust housing 100, the heat of the exhaust gas is released to the penetrated portion of the exhaust housing 100. Since the heat blocking unit 400 prevents the heat released from the portion penetrated by the shaft 300 from flowing to the power transmission device 200, the power transmission device 200 is not damaged by the heat of higher temperature. Therefore, the power transmission device 200 minimizes damage caused by heat at a higher temperature, thereby improving durability.

The present invention will now be described in detail. As shown in fig. 2 and 4, the exhaust housing 100 may include a through-hole 110 through which the shaft 300 passes, and the heat blocking unit 400 may have a cover unit 410, the cover unit 410 being configured to cover an outer peripheral portion 110a of the through-hole 110 in the exhaust housing 100 in a state of being mounted on the shaft 300.

Thus, the exhaust housing 100 is provided with the through hole 110 through which the shaft 300 passes. The through-hole 110 is a passage through which the shaft 300 passes in the exhaust housing 100. The shaft 300 is shown passing through the upper and lower sides of the exhaust housing 100 in the vertical direction. However, the through-hole 110 may be selectively formed only at the upper side, or the through-hole 110 may be formed at both the upper and lower sides. The bearing member 500 is disposed in the through-hole 110. When the through-holes 110 are provided at both the upper and lower sides of the exhaust housing 100, the bearing member 500 may be provided at each of the upper and lower sides.

Here, the bearing member 500 may be provided to close the through hole 110, and may be configured to support the rotational motion of the shaft 300 by surrounding the shaft 300. The bearing member 500 may include a bearing 510, a holder 520, and a bearing cover 530, the bearing 510 surrounding the shaft 300; the holder 520 is disposed at an upper side of the bearing and supports an elastic member 420 (described later); the bearing cap 530 is configured to surround the bearing 510 and the retainer 520, and is fixedly installed in the through hole 110. Accordingly, the bearing member 500 may be fixed to the through hole 110, and the shaft 300 may be rotatably supported in a state of being fixed to the through hole 110.

Meanwhile, the heat blocking unit 400 is provided with a cover unit 410, and the cover unit 410 is formed to shield the through-hole 110 in the exhaust housing 100 and the peripheral portion 110a of the through-hole 110. The cover unit 410 may be formed in a tapered shape, and in a state where the cover unit 410 is mounted on the shaft 300, the cover unit 410 may be disposed separately from the exhaust housing 100 while shielding the peripheral portion 110a of the through-hole 110 and the through-hole 110 in the exhaust housing 100. Therefore, the heat discharged through the through-holes 110 does not flow to the power transmission device 200 side through the cover unit 410, and the path of the heat is switched to a portion separated from the exhaust housing 100 so that the heat can be released to the lateral side.

One embodiment of the connection relationship between the heat blocking unit 400 and the shaft 300 is as follows.

As shown in fig. 4 and 5, the heat blocking unit 400 includes an elastic member 420, the elastic member 420 being disposed to contact one end portion of the bearing member 500 inside the cover unit 410 and to press the bearing member 500 toward the through-hole 110 side; the shaft 300 is provided with a support protrusion 310, and the support protrusion 310 is located at the other end of the bearing member 500 and protrudes in the circumferential direction such that the bearing member 500 is seated on the support protrusion 310, whereby the bearing member 500 can be restricted from moving toward the exhaust housing 100.

In other words, since the exhaust housing 100 is provided with the through-hole 110 through which the shaft 300 passes, heat of higher temperature of the exhaust gas is released through the through-hole 110. However, since the bearing member 500 disposed in the through-hole 110 closes the through-hole 110 while supporting the rotation of the shaft 300, the amount of heat released through the through-hole 110 is reduced. Therefore, the bearing member 500 should be fixed in the through hole 110.

For this reason, since the elastic member 420 is disposed inside the heat blocking unit 400, and the elastic member 420 applies an elastic force to press the bearing member 500 toward the side of the through-hole 110, the bearing member 500 is restricted from being separated to the side of the through-hole 110. In addition, since the shaft 300 has the support protrusion 310 at the other end of the bearing member 500 and the bearing member 500 is seated on the support protrusion 310, the bearing member 500 is restricted from being separated to the other side of the through-hole 110.

Because of this, since the bearing member 500, which is disposed in the through-hole 110 and rotatably supports the shaft 300, is pressed against the support protrusion 310 by the elastic member 420 disposed inside the cover unit 410 of the heat blocking unit 400 in a state of being seated on the support protrusion 310 of the shaft 300, the bearing member 500 can be closely contacted with the support protrusion 310 of the shaft 300 to be fixed in place, and the heat released through the through-hole 110 can be reduced.

Meanwhile, the power transmission device 200 is provided with the rotation shaft 230 configured to transmit the rotational power, the heat blocking unit 400 is provided with the connection part 430 extending from the cover unit 410 and coupled to the rotation shaft 230, and the connection part 430 may be provided with the mounting groove 431, and the mounting groove 431 is recessed such that the shaft 300 is inserted therein.

As shown in fig. 4 and 5, the heat blocking unit 400 is configured such that the rotation shaft 230 configured to transmit the rotational power of the power transmission device 200 is connected to one side of the heat blocking unit 400, and the shaft 300 is connected to the other side of the heat blocking unit 400. Accordingly, since the heat blocking unit 400 includes the connection part 430 and the mounting groove 431, the connection part 430 extends from the cap cover unit 410 to one side and is coupled to the rotation shaft 230 in the axial direction, and the mounting groove 431 is recessed on the other side of the connection part 430 such that the shaft 300 is inserted therein, and thus, the rotation shaft 230 and the shaft 300 are coupled to each other in the axial direction through the heat blocking unit 400.

In this way, as described above, since the rotation shaft 230 and the shaft 300 of the power transmission device 200 are connected to each other by the heat blocking unit 400, rather than being directly connected to each other, it is possible to prevent the shaft 300 extending through the exhaust housing 100 from receiving heat of higher temperature of exhaust gas and directly transmitting the heat of higher temperature of exhaust gas to the power transmission device 200 side through the rotation shaft 230. In other words, since the rotation shaft 230 and the shaft 300 of the power transmission device 200 are axially coupled to one side and the other side of the heat blocking unit 400, respectively, the heat blocking unit 400 and the shaft 300 may be rotated together by the rotational power transmitted from the power transmission device 200 so as to adjust the opening degree of the valve 301, and the heat of the higher temperature transmitted through the shaft 300 is restricted from being transmitted to the power transmission device 200 side by the heat blocking unit 400. Therefore, the power transmission device 200 can be prevented from being damaged by the heat of the high temperature.

The connection between the rotation shaft 230 and the shaft 300 will be described in detail with reference to the above-described heat blocking unit 400. As shown in fig. 5, the connection part 430 of the heat blocking unit 400 is provided with a first opening 432, the shaft 300 is provided with a second opening 320, the second opening 320 corresponds to the first opening 432 in a state where the shaft 300 is inserted into the mounting groove 431 of the connection part 430, and the fastening pin P1 is inserted into the first and second openings 432 and 320 so that the heat blocking unit 400 and the shaft 300 can be connected to each other.

Accordingly, the first opening 432 provided in the connection part 430 of the heat blocking unit 400 and the second opening 320 provided in the shaft 300 may be positioned to be matched with each other in a state where the shaft 300 is inserted into the mounting groove 431 of the heat blocking unit 400. In addition, when the fastening pin P1 is coupled through the first and second holes 432 and 320, the heat blocking unit 400 and the shaft 300 are connected to each other.

In addition, the first opening 432 may be formed to have a size greater than or less than that of the second opening 320. Since the first and second holes 432 and 320 are formed to have different sizes, a gap for allowing the fastening pin P1 passing through the first and second holes 432 and 320 to be movable is secured.

For example, when the size of the first hole 432 formed in the connection part 430 of the heat blocking unit 400 is smaller than the size of the second hole 320 formed in the shaft 300, the heat blocking unit 400 and the fastening pin P1 are movable in the shaft 300. This enables absorption of assembly tolerances in the axial direction when assembling the rotary shaft 230, the heat block unit 400, and the shaft 300 of the power transmission device 200, thereby achieving a smooth assembly relationship.

Meanwhile, as shown in fig. 6 and 7, the rotation shaft 230 may be provided at an end corresponding to the connection portion 430 with an insertion protrusion or slot 230a, and the connection portion 430 may be provided with an insertion slot or protrusion 433 that matches the rotation shaft 230.

Fig. 6 and 7 show that the insertion groove 230a is provided in the rotation shaft 230, and the insertion protrusion 433 is provided in the connection portion 430 of the heat blocking unit 400. The insertion protrusion 433 of the heat blocking unit 400 may be inserted into the insertion groove 230a in the rotation shaft 230 such that the rotation shaft 230 and the heat blocking unit 400 may be rotated together by receiving the rotational power from the power transmission device 200.

For this, the insertion groove 230a in the rotation shaft 230 has a shape elongated and recessed in the form of a single groove, and the insertion protrusion 433 of the heat blocking unit 400 may have the same shape as the insertion groove 230a, so that the heat blocking unit 400 may be rotated together with the rotation shaft 230 when the rotation shaft 230 is rotated in a state in which the insertion protrusion 433 is inserted into the insertion groove 230 a.

Since the insertion protrusion 433 has the fastening structure inserted into the insertion groove 230a as described above, an additional fixing tool is not required, and the rotational power transmitted from the power transmission device 200 can be smoothly transmitted to the rotation shaft 230, the heat blocking unit 400, and the shaft 300.

Meanwhile, as shown in fig. 4 to 6, the heat blocking unit 400 may be provided with an insulation unit 440, the insulation unit 440 is installed in the connection portion 430 to be located between the power transmission device 200 and the cover unit 410, and the insulation unit 440 is configured to radiate and radiate heat transmitted through the exhaust case 100 and the cover unit 410.

The heat insulation unit 440 is disposed between the exhaust housing 100 and the power transmission device 200 to block the heat of higher temperature from being transmitted to the power transmission device 200, and as can be seen from fig. 6, the heat insulation unit 440 may include a plurality of heat radiation fins 441. The heat insulation unit 440 may be mounted to and fixed to the connection portion 430 of the heat blocking unit 400, and may be formed to have a region such that heat of higher temperature transferred through the exhaust housing 100 may be blocked by the heat blocking unit 400 first, and may be blocked by the heat insulation unit 440 second, thereby minimizing heat of higher temperature transferred to the power transmission device 200.

Meanwhile, as shown in fig. 3, the power transmission device 200 may include a housing 210, the housing 210 having a motor unit 220 accommodated therein to generate rotational power, a rotation shaft 230, and a vibration absorbing unit 240; the rotation shaft 230 is disposed inside the housing 210 to transmit the rotational power transmitted from the motor unit 220 to the shaft 300; the vibration absorbing unit 240 is disposed inside the housing 210, and is configured to rotatably support the rotation shaft 230 from the housing 210 and to absorb vibration. Here, the housing 210 is further provided with a bracket B connected to the exhaust housing 100 so that the power transmission device 200 and the exhaust housing 100 can be fixed.

In this way, the motor unit 220 and the vibration absorbing unit 240 are accommodated in the housing 210, and the rotation shaft 230 is connected to the motor unit 220 so as to receive the rotation power. In particular, since the rotation shaft 230 is seated on the vibration absorbing unit 240 in a state of being connected to the motor unit 220, it is possible to attenuate vibration transmitted through the rotation shaft 230, thereby preventing the motor unit 220 from being damaged by the vibration.

Here, the vibration absorbing unit 240 may include a worm wheel unit 241, the worm wheel unit 241 rotating by receiving the rotational power from the motor unit 220, and a damper unit 242, the damper unit 242 being disposed on the worm wheel unit 241 and absorbing the vibration. The rotation shaft 230 may include a shaft portion 231 and a support portion 232, the shaft portion 231 penetrating the worm gear unit 241 and transmitting the rotation power to the shaft 300; the supporting portion 232 protrudes from the shaft portion 231 to be mounted on the worm wheel unit 241 and to be seated on the damper unit 242.

As can be seen from fig. 3, the vibration absorbing unit 240 includes a worm gear unit 241 and a damper unit 242, wherein the worm gear unit 241 rotates within the housing 210 by receiving rotational power from the motor unit 220. Here, a screw rotated by the rotational power extends from the motor unit 220, and the worm gear unit 241 includes a gear formed on an outer circumferential surface thereof to be engaged with the screw, so as to receive the rotational power, so that the rotational power of the motor unit 220 may be transmitted to the worm gear unit 241 through the screw, and the worm gear unit 241 may be rotated.

The worm wheel unit 241 is provided with a damper unit 242, and the damper unit 242 is made of a rubber material so as to absorb vibration, so that vibration transmitted from the rotation shaft 230 can be attenuated. Here, the rotation shaft 230 includes a shaft portion 231 and a support portion 232, the shaft portion 231 penetrates the worm wheel unit 241 and is connected to the shaft 300; the supporting portion 232 protrudes from the shaft portion 231 to be mounted on the worm wheel unit 241. In other words, the support portion 232 of the rotation shaft 230 is mounted on the worm wheel unit 241 and rotates together with the worm wheel unit 241. Since the support portion 232 of the rotation shaft 230 is seated on the damper unit 242 while being mounted on the worm wheel unit 241, vibration generated from the shaft 300 is prevented from being transmitted to the motor unit 220 through the rotation shaft 230.

Thereby, the power transmission device 200 can transmit the rotational power generated in the motor unit 220 to the worm gear unit 241 constituting the vibration absorbing unit 240, and the rotation shaft 230, the heat blocking unit 400, and the shaft 300 can be rotated together with the worm gear unit 241, thereby adjusting the opening degree of the valve 301. In particular, since the rotation shaft 230 is seated on the damper unit 242 provided on the worm wheel unit 241, the vibration transmitted through the rotation shaft 230 can be attenuated by the damper unit 242, so that the vibration transmitted to the motor unit 220 can be minimized.

The variable exhaust valve assembly of the vehicle having the above-described structure minimizes damage to the power transmission device 200 (which is used to adjust the opening degree of the valve) caused by heat of a higher temperature of exhaust gas, and reduces vibration transmitted to the power transmission device 200, thereby improving durability of the power transmission device 200.

While the present disclosure has been illustrated and explained with respect to the embodiments thereof, it will be apparent to those skilled in the art that various modifications and changes may be made to the present disclosure without departing from the scope and technical concept of the present invention as defined in the appended claims.