Patent Publication Number: US-8525089-B2

Title: Wing device and flight vehicle having the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Pursuant to 35 U.S.C. §119(a), this application claims the benefit of earlier filing date and right of priority to Korean Application No. 10-2010-0060830, filed on Jun. 25, 2010, the contents of which is incorporated by reference herein in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a wing device for a flight vehicle whose wing deploys responsive to launching, and a flight vehicle having the same. 
     2. Background of the Invention 
     A flight vehicle (flying object, aerial vehicle) is provided with wings for a stable flight. Especially, for guided missiles or the like, wings may be configured to be folded within a launching tube and then deployed out of a fuselage at an appropriate flying time after being slid out of the launching tube. 
     Such foldable wings are typically designed in a shape of a curved surface in correspondence with an outer appearance of a flight vehicle for minimization of their installation space. However, the wings having the curved surfaces may cause a rotational motion due to a difference of a pneumatic force applied to both surfaces of each wing during flight, thereby lowering stability of the flight vehicle. Furthermore, since each wing is typically supported only by a force of a deployment spring, the wing is not completely fixed after deployment and thereby a clearance problem is caused between the wing and a main body of the flight vehicle. Since such clearance lowers the stability of flight, a problem may be caused that the structure of the wing is difficult to be applied to flight vehicles, which need to be accurately guided. 
     Consequently, a wing device which is capable of further improving the stability of a flight vehicle may be considered. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of the present invention is to provide a wing device capable of completely fixing wings after deployment, and a flight vehicle having the same. 
     Another object of the present invention is to provide a wing device capable of providing high stability of a flight vehicle even with a simplified structure. 
     To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a wing device for a flight vehicle including a fixing shaft disposed in a lengthwise direction of a main body of the flight vehicle, a wing rotatably mounted to the fixing shaft so as to be deployed from a state of being laid on an outer circumferential surface of the main body to an erected state, and slidable along the fixing shaft, a fixing groove formed to face the wing in a sliding direction of the wing, and a spring unit configured to apply a first elastic force in an outer circumferential direction of the main body for deployment of the wing, and apply a second elastic force in a lengthwise direction of the main body for inserting the wing into the fixing groove. 
     In one aspect of the present invention, the spring unit may be wound on the fixing shaft in the outer circumferential direction of the main body to generate the first and second elastic forces. The spring unit may include a main body portion, a fixed portion and an extension portion. The main body portion may extend with being wound on the fixing shaft and have one end supported by the wing to generate the second elastic force. The fixed portion may be formed at another end of the main body portion to be fixed to the main body. The extension portion may extend from one end of the main body portion in an intersecting direction with the fixing shaft to generate the first elastic force and be supported by the wing in the outer circumferential direction. The first elastic force may be a torsional restoring force generated as the wing is laid, and the second elastic force may be a compressive restoring force generated in response to the sliding of the wing. 
     In another aspect of the present invention, a peripheral groove may be formed at the main body in the outer circumferential direction thereof so as to accommodate therein the wing in the laid state. The fixing groove may be recessed into a side surface of the peripheral groove in the lengthwise direction, and a fixing hole for inserting the fixing shaft therein may be formed at the fixing groove. The spring unit may be coupled to the peripheral groove, and a fixing ring may be formed to be wound on the peripheral groove. One side of the wing may be inclined with respect to a side surface of the peripheral groove or a lubrication member may be mounted onto the side surface of the peripheral groove, in order to reduce a friction generated during deployment of the wing. 
     In another aspect of the present invention, the wing may include an upper end portion, a lower end portion and an accommodation chamber. The upper end portion may form a free end rotating based upon the fixing shaft, and the lower end portion may have a through hole for inserting the fixing shaft therethrough such that the wing is rotatably coupled to the main body. The accommodation chamber may be formed at the lower end portion for accommodating the spring unit therein. The wing may be formed such that the upper end portion and the lower end portion are connected in a linear form. 
     In one aspect of the present invention, there is provided a flight vehicle including a main body of the flight vehicle, a fixing shaft disposed in a lengthwise direction of the main body, a wing rotatably mounted to the fixing shaft so as to be deployed from a state of being laid on an outer circumferential surface of the main body to an erected state, and slidable along the fixing shaft, a fixing groove formed to face the wing in a sliding direction of the wing, and a spring unit configured to apply a first elastic force in an outer circumferential direction of the main body for deployment of the wing, and apply a second elastic force in a lengthwise direction of the main body for inserting the wing into the fixing groove. The wing may be pressed by an inner wall of a launching tube in the laid state if the main body is disposed within the launching tube. 
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. 
       In the drawings: 
         FIG. 1  is an overview of a flight vehicle in accordance with one embodiment of the present invention; 
         FIGS. 2A and 2B  are a front view and a sectional view, respectively, showing an accommodated state of the flight vehicle of  FIG. 1  in a launching tube; 
         FIG. 3  is a disassembled view of a wing device shown in  FIG. 1 ; 
         FIGS. 4A to 4C  are operational views respectively showing a folded state, an unfolded state and a fixed state of the wing; and 
         FIG. 5  is an enlarged view showing a variation of a wing device according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Description will now be given in detail of the preferred embodiments according to the present invention, with reference to the accompanying drawings. This specification employs like/similar reference numerals for like/similar components irrespective of different embodiments, so they all will be understood by the first description. The expression in the singular form in this specification will cover the expression in the plural form unless otherwise indicated obviously from the context. 
       FIG. 1  is an overview of a flight vehicle in accordance with one embodiment of the present invention, and  FIGS. 2A and 2B  are a front view and a sectional view, respectively, showing an accommodated state of the flight vehicle of  FIG. 1  in a launching tube. 
       FIG. 1  shows a guided missile as an example of a flight vehicle  100 , and as shown, the flight vehicle  100  may include a main body  110  and wings  120 . 
     The main body  110  may be formed to be flied by virtue of a propulsive force, and include a front end section  111  and a rear end section  112 . 
     The front end section  111  may be formed at a front end with respect to a proceeding direction of the main body  110 , and configured in a streamline form. The rear end section  112  may be formed at an opposite side to the front end section  111 . The wings  120  may be disposed at the rear end section  112  to urge the main body  110  proceed in one direction. The wings  120  may be provided in plurality so as to be disposed at a preset interval along a circumference of the main body  110 . The wings  120  may allow the flight vehicle  100  to keep flying straight ahead in a stable state. However, the present invention may not be limited to the structure. Alternatively, the wings  120  may be disposed at the front end section  111  or between the front end section  111  and the rear end section  112 . 
     Referring to  FIGS. 2A and 2B , the wings  120  may be disposed within a launching tube  130  in a state of being laid on an outer circumferential surface of the main body  110 . Accordingly, the diameter of the launching tube  130  may be further reduced, and also the rear end section of the main body  110  may be guided along an inner wall of the launching tube  130  upon launching of the flight vehicle  100 . 
     Upon launching of the flight vehicle  100 , the wings  120  may be deployed, by virtue of a wing device  200 , from the laid state (hereinafter, referred to as “folded state” of the wing) on the outer circumferential surface of the main body  110  to an erected state (hereinafter, referred to as “unfolded state” of the wing). Hereinafter, the wing device  200  of  FIG. 1  will be described in more detail with reference to  FIG. 3  and  FIGS. 4A to 4C . 
       FIG. 3  is a disassembled view of the wing device  200  of  FIG. 1 , and  FIGS. 4A to 4C  are operational views respectively showing a folded state, an unfolded state and a fixed state of the wings  120 . 
     Referring to  FIG. 3 , the wing device  200  of the flight vehicle may include a fixing shaft  211 , a fixing groove  220  and a spring unit  230 , as well as the wing  120 . 
     The fixing shaft  211  may be disposed in a lengthwise direction of the main body  110 , and the wing  120  may be rotatably coupled to the corresponding fixing shaft  211 . For instance, a lower end portion  122  of the wing  120  is coupled to the fixing shaft  211  by a hinge, and an upper end portion  121  of the wing  120  may rotate toward an outer circumference of the main body  110  so as to implement the folded state and the unfolded state of the wing  120 . That is, the upper end portion  121  of the wing  120  may act as a free end, which is rotatable centering around the fixing shaft  211 . 
     The main body  110  of the flight vehicle  100  may include a peripheral groove  240  formed along the outer circumferential direction of the main body  110  for accommodating the wings  120  therein in the folded state. The lower end portion  122  of each wing  120  may be accommodated in the peripheral groove  240 . The fixing shaft  211  may be mounted to fixing holes  212   a  and  212   b , formed at the main body  110 , through the lower end portion  122  of the corresponding wing  120 . The fixing holes  212   a  and  212   b  may be formed in pair, so as to be present to face each other. 
     As shown, each wing  120  may be formed to be slidable in the lengthwise direction of the main body  110  along the fixing shaft  211 . A through hole  123  through which the fixing shaft  211  is inserted may be formed through the lower end portion  122  of each wing  120 . As the through hole  123  is guided by the fixing shaft  211  such that the wing  120  can move along the fixing shaft  211 . 
     The fixing groove  220  may be formed to face the wing  120  in a sliding direction of the wing  120 . The fixing groove  220  may be recessed into a side surface of the peripheral groove  240  in the lengthwise direction of the main body  110  such that at least part of the wing  120  is inserted therein. One (e.g.,  212   b ) of the fixing holes  212   a  and  212   b  facing each other may be formed at one side of the fixing groove  220 . 
     The spring unit  230  may apply a first elastic force in an outer circumference of the main body  110  such that the wing  120  can be deployed, and apply a second elastic force in the lengthwise direction of the main body  110  such that the wing  120  can be inserted in the fixing groove  220 . 
     At least part of the spring unit  230  may be wound on the fixing shaft  211  in an outer circumferential direction of the main body  110  so as to generate the first and second elastic forces. The first elastic force may be a torsional restoring force, which is generated as the wing  120  is folded, and the second elastic force may be a compressive restoring force, which is generated as the wing  120  is slid. Such forces may be implemented by the shape of the spring unit and a coupling mechanism thereof. 
     Referring to  FIG. 3 , the spring unit  230  may include a body portion  231 , a fixed portion  232  and an extension portion  233 . 
     The body portion  231  may be configured as a coil which extends in a lengthwise direction of the fixing shaft  211  with being wound on the fixing shaft  211 . The body portion  231  may have one end supported by the wing  120  so as to generate the torsional restoring force. In more detail, the lower end portion  122  of the wing  120  is shown, having an accommodation chamber  124  for accommodating the spring unit  230  therein, and a lengthwise end portion of the body portion  231  may support one side of the accommodation chamber  124 . The accommodation chamber  124  may be formed, for example, by cutting off at least part of the central area of the lower end portion  122 . 
     The fixed portion  232  may be formed at another end of the body portion  231 , and fixed to the main body  110  of the flight vehicle. A fixing ring  250  formed to be wound on the peripheral groove  240  may be mounted onto the peripheral groove  240  so as to allow coupling of the spring unit  230 . As the fixed portion  232  is inserted into the fixing ring  250 , the spring unit  230  can be secured with the main body  110  of the flight vehicle. Here, the present invention may not be limited to the structure. Alternatively, a coupling hole to which the fixed portion  232  is coupled may be formed, for example, at a bottom of the peripheral groove  240 . 
     The extension portion  233  may extend in an intersecting direction with the fixing shaft  211  from one end of the body portion  231  so as to generate the first elastic force, and supported by the wing  120  in an outer circumferential direction of the main body  110 . As the extension portion  233  projects from an outer circumference of the coil, when the wing  120  rotates in a direction to be folded, the wing  120  may apply a force to the extension portion  233  in a direction of the coil being wound or vice versa. Such mechanism may allow the spring unit  230  to act as a torsion spring with respect to the wing  120  in the outer circumferential direction of the main body  110 . 
     Referring to  FIG. 4A , the wings  120  are restricted in the folded state. The restriction may be implemented by but not limited to the inner wall of the launching tube (see  130  of  FIG. 2A ). Alternatively, a restriction device may separately be provided in the flight vehicle  100  or the launching tube  130 . In the folded state, a torsional force (twisting force, torque) or a compressive force may be applied to the spring unit  230 . Upon launching of the flight vehicle  100 , referring to  FIG. 4B , the wing  120  may rotate to the unfolded state by virtue of the torsional restoring force of the spring unit  230 . 
     When the wing  120  is unfolded, referring to  FIG. 4C , the wing  120  is slid along the fixing shaft  211  responsive to the compressive restoring force of the spring unit  230 , accordingly, one side of the wing  120  is inserted into the fixing groove  220 . The fixing groove  220  may be formed to have an inclined side surface such that the width thereof can be narrowed in the direction that the wing  120  is slid. Consequently, the wing  120  can be inserted into the fixing groove  220 . 
     Hence, as the wing device  200  urges the wings  120  rotated and slid, the wings  120  may be fixed firmly in the unfolded state with coming out of the launching tube  130 . 
     Referring to  FIGS. 3 and 4A , the wing  120  may be configured such that its upper end portion  121  and the lower end portion  122  may be connected in a linear form. Owing to the linear form of the wing  120 , an unbalance of a pneumatic force due to the shape of the wing  120  may not be caused during flight of the flight vehicle  100 . Also, the wing  120  may be formed to externally come in contact with the peripheral groove  240  between the upper end portion  121  and the lower end portion  122 , thereby minimizing the interference with the launching tube  130  (see  130  of  FIG. 2A ) upon being assembled to the launching tube  130 . 
     Referring to  FIGS. 3 and 4B , in order to alleviate a friction during deployment of the wing  120 , one side of the wing  120  may be formed to be inclined with respect to the side surface of the peripheral groove  240 . In more detail, the deployment of the wing  120  is executed with the rear edge of the wing  120  coming in contact with the side surface of the peripheral groove  240 . Therefore, to reduce the friction therebetween during the deployment, a string of the lower end portion  122  may be formed to be longer than the string of the upper end portion  121 . 
       FIG. 5  is an enlarged view showing a variation of a wing device according to the present invention. Hereinafter, the description of the like/similar configurations to the embodiment illustrated with reference to  FIG. 4B  will be understood by the first description. 
     Referring to  FIG. 5 , a lubrication member  360  may be disposed at a side surface of a peripheral groove  340 . The lubrication member  360  may be configured to cover a side surface of the peripheral groove  340 , which is contacted by a rear edge of the wing  120 . The lubrication member  360 , for example, may be coated on the side surface of the peripheral groove  340  in a friction reducing coating manner, such as processing with a solid fluid film layer. Accordingly, the friction caused during deployment of the wing  120  can be further reduced, and a fast deployment and fixing of the wing can be achieved. 
     With the configurations of the wing device and the flight vehicle having the same, the spring unit allows the wing to be rotated and slid, which results in implementation of a more simplified wing deployment and fixing mechanism. Therefore, the wing device can be facilitated to be mounted in the main body of the flight vehicle. Also, any separate component is not needed due to the simplified structure, thereby providing the effects of reduction of volume and weight of the flight vehicle. 
     In addition, the wing can be deployed and simultaneously fixed owing to the employment of the spring unit and the fixing groove, accordingly, a clearance generated during fixing of the wing can be minimized and the wing can be firmly fixed to the main body. The firm fixing of the wing can improve stability and control of the flight vehicle. Therefore, the wing device can be applied to flight vehicles, such as guide missiles, which are to be accurately guided, as well as flight vehicles, such unguided rockets. 
     Furthermore, the wing may be formed in a linear form so as to minimize the unbalance of a pneumatic force caused due to the shape of the wing and to implement a linear wing, which is foldable in a minimized space within a launching tube through a peripheral groove. 
     The configurations and methods of the wing device of the flight vehicle and the flight vehicle having the same in the aforesaid embodiments may not be limitedly applied, but such embodiments may be configured by a selective combination of all or part of each embodiment so as to derive many variations. 
     As the present features may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.