Patent Publication Number: US-2023159189-A1

Title: Drone propeller for preventing complete destruction and drone comprising same

Description:
TECHNICAL FIELD 
     The present invention relates to a drone propeller, and more particularly, to a drone propeller which allows only a part of a propeller to be damaged when the propeller collides during rotation, thereby allowing a drone to land without crashing. 
     BACKGROUND ART 
     A collision with an obstacle in drone control is one of the biggest causes of drone crashes. A phenomenon upon a collision with an obstacle leads to a series of results such as 1. a collision between the obstacle and a propeller, 2. a power failure of one or more flight shafts due to damage to the propeller, 3. overturning of the drone in a direction of a power failure shaft, and 4. a crash and damage of the drone. 
     In general, currently used drones are classified as “multicopters” according to a classification of aircraft, include an even number of four or more propeller shafts, and are propelled toward a ground surface to levitate. Here, a propeller plays an essential role in levitating a drone, and in general, a loss of one or more propellers leads to a drone crash. However, in the case of a drone with six or more shafts, the drone can maintain a hovering state without crashing until all propellers in corresponding directions are lost. 
     Horizontal movement of a drone is performed as follows. 1. Output of a shaft motor, which is disposed in a direction opposite to a direction in which the drone is to move, is increased, 2. the drone tilts in the direction in which the drone is to move, and 3. the drone tilts and moves. Next, vertical movement of the drone is performed as follows. 1. Output of all motors is increased/or decreased, and 2. as a result, the drone moves vertically. 
     A device called a gyroscope is used for a drone including a plurality of flight shafts to maintain balance without tilting in one direction. A gyroscope is the most basic sensor mounted on a main control unit (center) of a drone and is mounted on most drones currently on the market. A gyroscope is a device that detects a tilt. In a normal situation, the gyroscope detects a tilt of a drone, and when the drone tilts the gyroscope transmits more power in a tilt direction and finely adjusts output of a motor in the tilt direction at a degree of 105 to 110 according to a tilted state to maintain a level of the drone. 
     Motors of all drones have enough output to be able to hover even when some propellers are lost. This is because, for a climbing maneuver, the motors have more output than stop hovering. Therefore, in a case in which a propeller of a drone collides with an obstacle and is damaged, when only a portion of the propeller is lost, by increasing output of a motor, the remaining propeller maintains enough rotational force to enable stop hovering, and thus safe descent is possible. However, most broken pieces have random shapes, in general, the propeller is broken up to the vicinity of a rotary shaft, and thus the drone cannot maintain hovering and may immediately crash. 
     In the case of a drone crash, a loss may occur due to damage to the drone, and there is also a possibility that various types of human and material damage may occur due to a collision caused by the crash. Thus, there is a need for measures to cope with a drone crash. 
     Conventional drone propeller-related technologies mainly relate to implementing functions of a blade separation and detachment type, a length-variable type blade, a folding blade, and the like and thus lack provision for damage to a propeller. Related arts include Korean Patent Registration No. 10-1907649, Korean Patent Publication No. 10-2020-0028578, and Korean Utility Model No. 20-2019-0002525. 
     DISCLOSURE 
     Technical Problem 
     The present invention is directed to providing a drone propeller for preventing complete destruction, which prevents a complete power failure when a propeller is damaged and allows a drone to safely land through hovering and descending maneuvers, and a drone including the propeller. 
     Technical Solution 
     According to an embodiment of the present invention, a drone propeller for preventing complete destruction includes a plurality of blades ( 1 ) and a rotary shaft ( 2 ), wherein each of the blades ( 1 ) includes a rotation retaining unit ( 11 ) formed to be connected to the rotary shaft ( 2 ), a separation and detachment unit ( 12 ) which is formed at an outer side of the blade ( 1 ) and is separated when damaged, and a damage inducing unit ( 13 ) which connects the rotation retaining unit ( 11 ) and the separation and detachment unit ( 12 ) and is damaged during a collision. 
     A crack ( 13   a ), which is recessed to be elongated in a transverse direction of the blade, may be formed in the damage inducing unit ( 13 ). 
     The rotation retaining unit ( 11 ) and the separation and detachment unit ( 12 ) may be formed to be separated from each other, and the damage inducing unit ( 13 ) may include an insertion hole ( 131 ) formed in a contact surface of the rotation retaining unit ( 11 ) or the separation and detachment unit ( 12 ) and an insertion protrusion ( 132 ) formed on a contact surface opposite to the contact surface in which the insertion hole ( 131 ) is formed so that the insertion protrusion ( 132 ) is inserted into the insertion hole ( 131 ) to form the blade ( 1 ). 
     The damage inducing unit ( 13 ) may further include a fixing pin ( 135 ), a pinhole ( 133 ) may be formed to pass through the blade from an outside of a side surface of the blade, in which the insertion hole ( 131 ) is formed, to an inside of the blade, in which the insertion hole ( 131 ) is positioned, such that the fixing pin is inserted therein, and a pin holder ( 134 ) recessed to accommodate a portion of the fixing pin ( 135 ) passing through the pinhole ( 133 ) may be formed in the insertion protrusion ( 132 ). 
     The damage inducing unit ( 13 ) may include an insertion protrusion ( 132 B) having a “¬” shape formed by forming a locking protrusion ( 1321 ) at an end portion of the insertion protrusion and a locking projection ( 1311 ) by which the locking protrusion ( 1321 ) is caught when the insertion protrusion ( 132   b ) is inserted into the insertion hole ( 131 ). 
     The damage induction unit ( 13 ) may further include a locking projection accommodation portion ( 1312 ) and a restoration spring ( 1313 ) for restoring the locking projection, and a locking projection pivoting shaft ( 1314 ) may be formed at a peripheral portion of the locking projection ( 1311 ) such that the locking projection is rotatable so that, when the locking protrusion ( 1321 ) is pushed, the locking projection ( 1311 ) is pushed into the locking projection accommodation portion ( 1312 ), and when the locking protrusion ( 1321 ) is completely inserted, the locking projection ( 1311 ) is restored again. 
     A locking projection ( 1311   b ) made of a leaf spring material may be formed as the locking projection, an outer end of the locking projection ( 1311   b ) may be fixed to a wall surface of the insertion hole ( 131 ), and an inner end thereof may be lifted to form a projection by which the locking protrusion ( 1321 ) is caught. 
     According to another embodiment of the present invention, a drone including a drone propeller for preventing complete destruction includes the drone propeller. 
     Advantageous Effects 
     In a drone propeller for preventing complete destruction and a drone including the propeller, when the propeller collides with an obstacle, damage to the propeller can be minimized as much as possible. Thus, since it is possible to prevent a complete power failure, output of a motor at a damaged position is increased to a level at which hovering is possible, and then safe landing is possible through a descending maneuver. Therefore, it is possible to prevent a loss due to damage to the drone and also to prevent various human and material accidents that occur during a drone crash. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a view illustrating a configuration of a drone propeller. 
         FIG.  2    is a view illustrating a drone propeller for preventing complete destruction according to an embodiment of the present invention. 
         FIG.  3    is a partial enlarged view showing another embodiment of a damage inducing unit of the present invention. 
         FIG.  4    is a partial enlarged view showing still another embodiment of a damage inducing unit of the present invention. 
         FIG.  5    is a partial enlarged view showing yet another embodiment of a damage inducing unit of the present invention. 
         FIG.  6    is a partial enlarged view showing yet another embodiment of a damage inducing unit of the present invention. 
     
    
    
     MODES OF THE INVENTION 
     Specific details for implementing a drone propeller for preventing complete destruction and a drone of the present invention will be described with reference to the accompanying drawings. 
       FIG.  1    is a view illustrating a configuration of a drone propeller that is generally widely used. As shown, the drone propeller includes two or more blades  1  which are formed to be elongated with respect to a rotary shaft  2 . 
     In a drone propeller for preventing complete destruction of the present invention, the key is to allow a propeller to be damaged in a set shape in order to prevent crashing during a collision with an obstacle, and thus the object is to allow a drone to land normally. If a drone can fly with an output of 100 in a normal situation, when only a set part is damaged by a collision like the propeller of the present invention and a remaining part maintains rotation, only output of a corresponding motor may be increased to maintain a hovering state, and thus the drone can land through a descending maneuver. 
     In the drone propeller for preventing complete destruction of the present invention, various embodiments can be implemented through application to a part that guides damage. In the present invention, embodiments are mainly classified into three types as shown in  FIGS.  2  to  6   , that is,  1 . a type using a crack shape,  2 . a friction type,  3 . a type using a fixing pin, and  4 . a type using a locking projection. 
     As a basic configuration of the drone propeller for preventing complete destruction of the present invention, the drone propeller includes two or more blades  1  and a rotary shaft  2 . Each of the blades  1  includes a rotation retaining unit  11  formed to be connected to the rotary shaft  2 , a separation and detachment unit  12  which is formed at an outer side of the blade and is separated when damaged, and a damage inducing unit  13  which connects the rotation retaining unit  11  and the separation and detachment unit  12  and is damaged during a collision. 
       FIG.  2    illustrates an embodiment of a type using a crack shape of the drone propeller of the present invention, and a crack  13   a,  which is recessed to be elongated like a ditch in a transverse direction of the blade, is formed in the damage inducing unit  13  to induce the separation and detachment unit  12  to be separated based on the crack during a collision. The crack is formed to a depth sufficient to allow the separation and detachment unit  12  to remain during a normal flight and allow the separation and detachment unit  12  to be separated during a collision. During a collision, a drone may lose only the separation and detachment unit  12 , and while the drone repeats slight vibration and restoration, the rotation retaining unit  11  may remain undamaged. 
       FIG.  3    illustrates an embodiment of a friction method of the drone propeller of the present invention. To this end, the rotation retaining unit  11  and the separation and detachment unit  12  are formed to be separated from each other. The damage inducing unit  13  includes an insertion hole  131  and an insertion protrusion  132 . The insertion hole  131  and the insertion protrusion  132  are coupled through an interference fit in a friction manner to connect the rotation retaining unit  11  and the separation and detachment unit  12 . Although the insertion hole  131  at a side of the rotation retaining unit  11  is illustrated in  FIG.  3    for such a shape, the insertion hole  131  that is deeply recessed may be formed in a contact surface of the rotation retaining unit  11  or the separation and detachment unit  12 , and the insertion protrusion  132  may be formed on an opposite connection surface of the rotation retaining unit  11  or the separation and detachment unit  12  to correspond to the insertion hole  131  so that the insertion protrusion  132  is inserted into the insertion hole  131  to form the blade  1 . Here, a friction force allows the separation and detachment unit  12  to endure a centrifugal force during rotation but allows the separation and detachment unit  12  to not resist an external force caused by a collision. 
       FIG.  4    illustrates an embodiment of a type using a fixing pin of the drone propeller of the present invention. In order to implement this type, the damage inducing unit  13  further includes a fixing pin  135  in addition to the components of  FIG.  3   . A pinhole  133  is formed to pass through the blade from the outside of a side surface of the blade, in which the insertion hole  131  is formed, to the inside of the wall, in which the insertion hole  131  is positioned, such that the fixing pin may be inserted therein. In addition, a pin holder  134  recessed to accommodate a portion of the fixing pin  135  passing through the pinhole  133  may be formed in the insertion protrusion  132 . Thus, after the separation and detachment unit  12  is insertion-coupled to the rotation retaining unit  11 , the fixing pin  135  is insertion-fixed. Thus, during normal flight, the separation and detachment unit  12  is rotated by being supported by the fixing pin  135 , but during a collision, the thin pin is broken to separate the separation and detachment unit  12 . Although the pinhole  133 , the pin holder  134 , and the fixing pin  135  are illustrated in  FIG.  4    as being formed at one side of the blade, the pinhole  133 , the pin holder  134 , and the fixing pin  135  may be installed at both sides of the blade if necessary. 
       FIGS.  5  and  6    illustrate embodiments of a type using a locking projection of the drone propeller of the present invention.  FIG.  5    illustrates a type using a locking projection of a rotation restoration type, and  FIG.  6    illustrates a type using a locking projection made of a leaf spring material. In order to implement this type, the damage inducing unit  13  includes an insertion protrusion  132   b  having a “¬” shape formed by forming a locking protrusion  1321  formed at an end portion of the insertion protrusion and further includes a locking projection  3111  by which the locking protrusion  1321  may be caught when the insertion protrusion  132   b  is inserted into the insertion hole  131 . 
     The locking projection  1311  may be implemented in various types, but as shown in  FIG.  5   , a locking projection of a rotation restoration type may be used. To this end, the damage inducing unit  13  further includes a locking projection accommodation portion  1312  and a restoration spring  1313  for restoring the locking projection. A locking projection pivoting shaft  1314  is formed at a peripheral portion of the locking projection  1311  such that the locking projection is rotatable. Thus, when the locking protrusion  1321  is pushed, the locking projection  1311  may be pushed into the locking projection accommodation portion  1312 , and when the locking protrusion  1321  is completely inserted, the locking projection  1311  may be formed to be restored again. 
     As another implementation type of the locking projection  1311 , as shown in  FIG.  6   , a locking member including a leaf spring material may be used. A locking projection  1311   b  made of a leaf spring material may be formed as the locking projection, and an outer end of the locking projection  1311   b  may be fixed to a wall surface of the insertion hole  131 , and an inner end thereof may be lifted to form a projection by which the locking protrusion  1321  may be caught. 
     Of course, a drone propeller for preventing complete destruction and a drone including the propeller and using the technical idea may belong to the scope of the present invention.