Actuator for an active air flap device

Abstract

Disclosed herein is an actuator 2 for an active air damper device, which can manually open air dampers 6 during a failure of the actuator 2 and prevent the opened air dampers 6 from closing using wind, for example, caused by the vehicle. The device comprises a worm gear 23 driven by the power of a motor 12 and a spur gear 24 configured to transmit a rotational force from the worm gear 23 to the air dampers 6.

Description

BACKGROUND OF THE INVENTIONField of the invention

[0001] The present invention relates generally to an actuator for an active louver device and, more particularly, to an actuator for an active louver device that can manually open louvers during a failure and prevent the opened louvers from being closed again, for example, by wind caused by the vehicle. Description of the related prior art

[0002] In general, as in Fig. 1 to 3, an air damper device for a vehicle includes a duct housing 1 fixed to a front-end module of a vehicle, an actuator 2 fixed to a central portion of the duct housing 1, an H-shaped guide frame 4 mounted on the duct housing 1 to connect the guide frame 4 to the actuator 2 by means of an actuator loader 3 to vertically move the guide frame 4 using the force of the actuator 2, and air dampers 6 rotatably mounted on the duct housing 1 and connected to the guide frame 4 by means of damper loaders 5.

[0003] One side of each air damper 6 is connected to the guide frame 4 via the damper loader 5, and the other side of each air damper 6 is rotatably coupled to the duct housing 1 via a hinge pin 7. The actuator 2 includes a printed circuit board (PCB) 11, a motor 12, a worm gear 13, and a plurality of spur gears 14.

[0004] Thus, when the actuator 2 is operated under external conditions (for example, the engine temperature, the coolant temperature, etc.), the force of the actuator 2 is transmitted to the guide frame 4 via the actuator loader 3 to move the guide frame 4 vertically to rotate the flap loader 5. Then, when the rotational force is transmitted from the flap loader 5 to the louvers 6 to rotate the louvers 6, vents 1a of the duct case 1 are opened or closed.

[0005] However, with the conventional actuator 2, which uses the worm gear 13 and the spur gear 14, it may be difficult to manually operate the air dampers 6 if the actuator fails. Furthermore, when the air dampers 6 are closed, the temperatures of an engine and other heat exchangers increase, causing potential damage to the vehicle.

[0006] In other words, as in Fig. 4 and Fig. 5, in the conventional actuator 2, the worm gear includes teeth 13a each having opposed surfaces 13b projecting at a substantially right angle relative to an axial longitudinal direction of the worm gear 13, and the spur gear includes teeth 14a each having opposed surfaces 14b projecting at a substantially right angle relative to a tangential direction of the spur gear 14. Thus, the teeth 13a and 14a have the friction force F2 greater than the rotational force F1, thus, when the actuator fails, the spur gear 14 cannot rotate, and the air dampers 6 connected to the spur gear 14 cannot be manually operated.

[0007] Specifically, during operation of the conventional actuator 2, when no failure occurs, the worm gear 13 can be rotated by the power from the motor 12 and works as a driving gear, and the spur gear 14 connected to the air dampers 6 works as a driven gear, whereas when a failure occurs and the air dampers 6 are manually operated, the spur gear 14 works as the driving gear and the worm gear 13 works as the driven gear.

[0008] In Fig. 5, reference symbol F3 is a composite force of the rotational force F1 and the frictional force F2, which is applied to the worm gear 13 by the spur gear 14.

[0009] From US 5 732 666 A an actuator for an active air damper device is known, the actuator comprising: a worm gear driven by the power from a motor; and a spur gear configured to transmit a rotational force from the worm gear to a plurality of air dampers, wherein the worm gear has a plurality of teeth each having opposing surfaces, and wherein the spur gear has a plurality of teeth meshing with the teeth of the worm gear and each having opposing surfaces.

[0010] US 2009 / 0 251 080 A1 discloses a device and method for adjusting the speeds at which an electric motor connected to a worm gear raises and lowers a window in a motor vehicle power window assembly. By axially displacing the motor armature and / or by altering the thread and tooth profile of the worm and gear, the torque generated by the motor and transmitted through the worm gear can be varied. To compensate for the effects of gravity on the motor load and the window raising and lowering speed, greater torque is provided when raising the window and less torque when lowering the window.

[0011] US 2003 / 0 233 899 A1 describes that when the drive of a drive unit is stopped, a first and a second gear limit the rotation of a final driven gear in both directions. With this arrangement, it is possible to reliably prevent the occurrence of rattling noises during rotation of the output shaft due to gear play. Furthermore, a unit that exerts a constant torque on the output shaft becomes unnecessary. Consequently, it becomes possible to design a compact power transmission mechanism and furthermore, it becomes possible to reduce costs.

[0012] The description relating to the related prior art is provided merely to aid in understanding the background of the disclosure and is not intended to be interpreted by those skilled in the art as constituting the related prior art. SUMMARY

[0013] Accordingly, the present invention provides an actuator for an active louver device that can manually open louvers during a failure and prevent the opened louvers from closing, for example, due to wind caused by the vehicle.

[0014] In accordance with one aspect of the present invention, an actuator for an active air damper device comprises: a worm gear driven by power from a motor; and a spur gear configured to transmit rotational force from the worm gear to the air dampers, wherein the worm gear has a plurality of teeth each having opposing surfaces asymmetrically inclined at different inclination angles relative to an axial longitudinal direction of the worm gear, and wherein the spur gear has a plurality of teeth meshing with the teeth of the worm gear and each having opposing surfaces asymmetrically inclined at different inclination angles relative to a tangential direction of the spur gear.The opposing surfaces of a tooth of the worm gear comprise a first surface inclined at a substantially rightward angle relative to an axial longitudinal direction of the worm gear, and a second surface having a greater inclination than the first surface. The opposing surfaces of a tooth of the spur gear comprise first and second surfaces inclined at the same angles as, and respectively parallel to, the first and second surfaces of the tooth of the worm gear.

[0015] Furthermore, when the air dampers rotate to close in a manual operation, the first surfaces of the teeth of the worm gear and the spur gear come into contact with each other, which prevents the air dampers from closing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings in which: Fig. 1 to 3 are explanatory views showing an air damper device for a vehicle in accordance with the related art; Fig. 4 and Fig. 5 are exemplary views showing a worm gear and a spur gear of a conventional actuator in accordance with the related art; Fig. 6 and Fig. 7 are exemplary views showing a worm gear and a spur gear of an actuator for an active air damper device in accordance with an exemplary embodiment of the present invention; and Fig. 8 and Fig. 9 are exemplary views showing a worm gear, a spur gear, and a stopper of an actuator for an active louver device in accordance with another exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0017] It is understood that the term "vehicle" or "vehicle..." or other similar expressions as used herein includes motor vehicles in general, such as passenger cars including four-wheel drive off-road vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft and the like, and includes hybrid vehicles, electric vehicles, internal combustion, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (for example, fuels produced from resources other than petroleum).

[0018] 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 is also to be understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of the recited features, integers, steps, acts, elements, and / or components, but do not preclude the presence or addition of one or more features, integers, steps, acts, 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 terms.

[0019] Reference will now be made in more detail to an exemplary embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or similar components.

[0020] As in Fig. 1, an air damper device for a vehicle may include a duct housing 1 fixed to a front-end module of a vehicle, an actuator 2 fixed to a central portion of the duct housing 1, an H-shaped guide frame 4 mounted on the duct housing 1 to connect the guide frame 4 to the actuator 2 by means of an actuator loader 3 to vertically move the guide frame 4 using the force of the actuator 2, and air dampers 6 rotatably mounted on the duct housing 1 to connect the air dampers 6 to the guide frame 4 by means of damper loaders 5.

[0021] One side of each air damper 6 is connected to the guide frame 4 by means of the damper loader 5, and the other side of each air damper 6 is rotatably coupled to the duct housing 1 by means of a hinge pin 7.

[0022] The actuator 2 may include a conventional printed circuit board (PCB) 11, a motor 12, a worm gear 13 disposed in the motor 12 to axially rotate the worm gear 13 using the power from the motor 12, and a plurality of spur gears meshing with the worm gear to transmit the power to the air flaps 6.

[0023] In an exemplary embodiment of the present invention, the worm gear 21 of the actuator 2 may have a spiral tooth 21a, as shown in Fig. 6 and Fig. 7, wherein opposing surfaces of the tooth 21a are asymmetrically inclined at different angles relative to an axial longitudinal direction of the worm gear 21. Furthermore, the opposing surfaces of a tooth 22a of the spur gear 22, which mesh with the opposing surfaces of the tooth 21a of the worm gear, may be asymmetrically inclined at different angles relative to a tangential direction of the spur gear 22.

[0024] In other words, the opposing surfaces of the tooth 21a of the worm gear may include a first surface 21b inclined at a substantially rightward angle relative to the axial longitudinal direction of the worm gear 21, and a second surface 21c having a greater inclination than the first surface 21b. Furthermore, the opposing surfaces of the tooth 22a of the spur gear may include first and second surfaces 22b and 22c inclined at substantially the same inclination angle as and substantially parallel to the first and second surfaces 21b and 21c of the tooth 21a of the worm gear, respectively.

[0025] In particular, when the air dampers 6 rotate to close in a manual operation, the first surfaces 21b and 22b of the teeth 21a and 22a of the worm gear and the spur gear come into contact with each other to prevent the air dampers 6 from closing.

[0026] In addition, if a failure does not occur and the motor 12 is driven by the actuator 2, then the worm gear may be arranged to rotate axially to cause the tooth 21a to transmit the power to the tooth 22a of the spur gear and rotate the spur gear 22, thus making it possible to open and close the air dampers 6.

[0027] If the actuator fails, the air dampers 6 can be opened manually. Particularly, if the air dampers 6 are manually rotated to be opened, the spur gear 22 connected to the air dampers 6 can be configured to rotate in a clockwise direction, as shown in Fig. 6, and the worm gear 21 may be configured to rotate substantially smoothly axially. Thus, the air dampers 6 can be manually opened during a failure.

[0028] In other words, when the spur gear 22 rotates in a clockwise direction, as in Fig. 6, the second surfaces 22c and 21c are brought into contact with each other by the teeth 22a and 21a. In particular, since the second surfaces 21c and 22c have larger inclination angles than the first surfaces, the rotational force F4 from the spur gear 22 can be greater than the frictional force F5 from the spur gear when the spur gear comes into contact with the worm gear 21, causing the spur gear 22 to rotate substantially smoothly and causing the worm gear 21 to be rotated substantially smoothly, thus allowing the louvers 6 to be manually opened even during a failure.

[0029] The inclination angle of the second surfaces 21c and 22c is a reference angle at which the rotational force becomes greater than the frictional force. The reference angle can range between 10° and 15°, but is not limited thereto.

[0030] Furthermore, the first surfaces 21b and 22b may be configured to restrict the closing of the louvers 6, which were opened in a manual operation, using wind caused by the vehicle. In other words, since the spur gear 22 may be configured to rotate in a clockwise direction to open the louvers and in a counterclockwise direction to close the louvers 6, the spur gear cannot be rotated in the counterclockwise direction to restrict the closing of the louvers. In the present embodiment, when the spur gear rotates in the clockwise direction, the first surfaces 22b and 21b may be brought into contact with each other by the teeth 22a and 21a of the spur gear 22 and the worm gear 21.In particular, the first surfaces 21b and 22b may have smaller inclination angles than the second surfaces, as shown in . Fig. 5, to cause the frictional force F2 from the spur gear with respect to the worm gear 21 to be greater than the rotational force F1 from the spur gear 22. Therefore, the spur gear 22 can be prevented from rotating to cause the worm gear 21 to be rotated, thus preventing the opened air flaps 6 from closing, utilizing, for example, wind caused by the vehicle.

[0031] The inclined angle of the first surfaces 21b and 22b is a reference angle at which the friction force becomes greater than the rotational force. The reference angle can range from 2° to 5°, but is not limited thereto.

[0032] In Fig. 7, reference symbol F6 is a composite force of the rotational force F4 and the frictional force F5, which is applied to the worm gear 21 by the spur gear 22.

[0033] In accordance with another embodiment of the present invention, as described in Fig. 8 and Fig. 9, an actuator 2 for an active air damper device may include a worm gear 23 driven by the power from a motor and a spur gear 24 configured to transmit the rotational force from the worm gear to the air dampers, wherein the worm gear 23 has a plurality of teeth 23a each having opposing surfaces 23b symmetrically inclined at an inclination angle relative to an axial longitudinal direction of the worm gear 23, and the spur gear 24 has a plurality of teeth 24a meshing with the teeth 23a of the worm gear and each having opposing surfaces 24b symmetrically inclined at substantially the same inclination angle as those 23b of the worm gear relative to a tangential direction of the spur gear 24.

[0034] In addition, the actuator 2 may include a stop 25 arranged in an actuator housing and configured to restrict the worm gear 23 from moving in one direction. In particular, when the air dampers 6 are manually operated to close, the stop 25 may be brought into contact with the worm gear 23 to restrict the worm gear 23 from moving in one direction.

[0035] If a failure does not occur in the actuator 2, as in Fig. 8, and the motor 12 is driven by the actuator 2, then the worm gear 23 and the spur gear 24 may be arranged to rotate smoothly to open and close the air flaps 6.

[0036] If the actuator 2 fails, the air dampers 6 can be opened manually. In particular, if the air dampers 6 are designed to be manually rotated in order to open, the spur gear 24 connected to the air dampers 6 can be designed to rotate in a clockwise direction in Fig. 8 and open, and thus the worm gear 23 can move to the right, as in Fig. 9. Thus, as in Fig. 9, the spur gear 24 may be arranged to rotate substantially smoothly, together with the axial rotation of the worm gear 23, to cause the air dampers 6 to open manually when the actuator 2 fails.

[0037] In addition, the worm gear 23 and the stop 25 can be configured to restrict the closing of the air flaps 6, which were opened in a manual operation, using, for example, wind caused by the vehicle. In other words, since the spur gear 24 can be configured to rotate in a counterclockwise direction to open the air flaps and can be configured to rotate in a clockwise direction to close the air flaps 6, the spur gear 24 cannot be rotated in the clockwise direction to prevent the air flaps 6 from closing. In the exemplary embodiment of the present invention, if the spur gear 24 is configured to rotate in the clockwise direction, then the worm gear 23 can be moved to the left, as in Fig. 9 to cause one end of the same to be brought into contact with the stop 25, as shown in Fig. 8 shown.

[0038] In addition, since the spur gear 24 can be restricted from rotating in a clockwise direction by the tooth 23a of the worm gear 23, the spur gear 24 and the worm gear 23 cannot be rotated together, which prevents the opened air flaps 6 from closing using wind caused by, for example, the vehicle.

[0039] As described herein, in accordance with the actuator 2 of the present invention, the shape of the teeth of the worm gear and the spur gear can vary, and the stop can be used in the actuator to manually open air flaps during a failure of the actuator and prevent the opened air flaps from closing using, for example, wind caused by the vehicle, thus improving the operational stability of components of the vehicle.

[0040] Although a preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will recognize that various changes, additions, and substitutions are possible without departing from the scope and spirit of the invention as disclosed in the appended claims.

Claims

[1] Actuator for an active air damper device, the actuator (2) comprising: a worm gear (21) driven by the power of a motor (12); and a spur gear (22) adapted to transmit a rotational force from the worm gear (21) to a plurality of air flaps (6), wherein the worm gear (21) has a plurality of teeth (21a) each having opposing surfaces which are asymmetrically inclined at different angles of inclination relative to an axial longitudinal direction of the worm gear (21), and wherein the spur gear (22) has a plurality of teeth (22a) which are engaged with the teeth (21a) of the worm gear (21) and each have opposing surfaces which are asymmetrically inclined at different inclination angles relative to a tangential direction of the spur gear (22); wherein the opposing surfaces of each tooth (21a) of the worm gear (21) have a first surface (21b) inclined at a substantially rightward angle of inclination relative to the axial longitudinal direction of the worm gear (21), and a second surface (21c) having a greater inclination than the first surface (21b); and wherein the opposing surfaces of each tooth (22a) of the spur gear (22) have first and second surfaces (22b, 22c) which are inclined at substantially the same angle of inclination as and parallel to the first and second surfaces (21b, 21c) of each tooth (21a) of the worm gear (21), respectively. [2] The actuator (2) according to claim 1, wherein when the louvers (6) rotate to be closed in a manual operation, the first surfaces (21b, 22b) of the teeth (21a, 22a) of the worm gear (21) and the spur gear (22) come into contact with each other, preventing the louvers (6) from closing.

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