PROPELLER GUARD, FLYING BODY, AND RESILIENT MECHANISM

A propeller guard 2 includes a propeller guard body 10 configured to surround a propeller 30 of a flight vehicle 20; and a repulsion mechanism 40 including a first end 45 and a second end 46 and provided to protrude on the propeller guard body 10 through the first end 45, in which the repulsion mechanism 40 includes a mechanism to separate the propeller guard body from an object in response to contact of the second end with the object.

TECHNICAL FIELD

The present disclosure relates to a propeller guard that protects a propeller of a flight vehicle, a flight vehicle, and a repulsion mechanism.

BACKGROUND ART

In recent years, a flight vehicle (for example, a drone, a multicopter, or the like) that flies by rotation of a plurality of propellers may be used for inspection of an infrastructure structure.

In Non Patent Literature 1, a method is disclosed of using a flight vehicle for inspection of pipeline facilities buried in the ground. When the flight vehicle flies in such a space surrounded by a wall surface, if the airframe collides with an object such as the wall surface, the propeller may be damaged and the airframe may crash. Thus, a propeller guard that protects the propeller may be attached to the airframe.

In Non Patent Literature 2, a propeller guard is devised for protecting a propeller when a flight vehicle collides with an object and preventing the flight vehicle from losing a flight balance and becoming uncontrollable even when the flight vehicle collides with the object.

CITATION LIST

Non Patent Literature

SUMMARY OF INVENTION

Technical Problem

However, when the flight vehicle moves in the vertical direction in a space surrounded by a wall surface, in the propeller guard devised in Non Patent Literature 2, there is a possibility that the guard frame comes into contact with the wall surface or the like and the flight vehicle cannot move, or the flight vehicle loses its balance and falls.

FIG.6is a cross-sectional view of a manhole. As illustrated inFIG.6, in a manhole50, when a manhole lid installed on the ground is opened and closed, a columnar or quadrangular prism structure51extends in the vertical direction in the ground, and a step52for a worker to go down to the underground or to go up to the ground is installed in the middle. The structure51is, for example, a reinforced concrete pipe. A manhole lid receiving frame53is provided near the road surface of the manhole50.

FIG.7is a diagram illustrating a problem in a case where a flight vehicle with a propeller guard moves in a space surrounded by a wall surface, such as the manhole50. As illustrated inFIG.7, when a flight vehicle100to which a propeller guard is attached is caused to ascend in the structure51, the propeller guard may be caught by the wall surface or the like of the structure51. In this case, there is a possibility that the flight vehicle100rotates in an R direction with a contact point P1between the propeller guard and the wall surface of the structure51as a fulcrum, and loses its flight balance and falls. Further, the flight vehicle100sucks air from above the propeller and discharges the air downward to float the airframe in the air. For that reason, when flight vehicle100rotates in the R direction (toward the wall surface of structure51), the propeller sucks air from above thereof, whereby there is a possibility that the flight vehicle100stick to the wall surface of the structure51.

An object of the present disclosure made in view of such circumstances is to provide a propeller guard, a flight vehicle, and a repulsion mechanism capable of suppressing occurrence of rotation of the flight vehicle due to contact with an object.

Solution to Problem

A propeller guard according to an embodiment includes: a propeller guard body configured to surround a propeller of a flight vehicle; and a repulsion mechanism including a first end and a second end and provided to protrude on the propeller guard body through the first end, in which the repulsion mechanism includes a mechanism to separate the propeller guard body from an object in response to contact of the second end with the object.

A flight vehicle according to an embodiment includes: a repulsion mechanism including a first end and a second end and provided to protrude on the flight vehicle through the first end; and the repulsion mechanism includes a mechanism to separate the flight vehicle from an object in response to contact of the second end with the object.

A repulsion mechanism according to an embodiment includes: a first end and a second end, in which the repulsion mechanism is attached to a propeller guard body configured to surround a flight vehicle or a propeller of the flight vehicle through the first end; and a mechanism to separate the flight vehicle from an object in response to contact of the second end with the object.

Advantageous Effects of Invention

According to the present disclosure, it is possible to provide a propeller guard, a flight vehicle, and a repulsion mechanism capable of suppressing occurrence of rotation of the flight vehicle due to contact with an object.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment will be described in detail with reference to the drawings. Note that the drawings are only schematically illustrated to the extent that the present invention can be sufficiently understood. Thus, the present invention is not limited only to the illustrated examples. In addition, for convenience of illustration, scales in the drawings may be different from actual scales, or may not match between the drawings.

FIG.1is an example of a perspective view of a flight vehicle including a propeller guard according to an embodiment. A flight vehicle with a propeller guard (Hereinafter, it is simply referred to as a “flight vehicle”.)1illustrated inFIG.1includes a propeller guard body10, a flight vehicle body20, one or more propellers30, and a repulsion mechanism40. Among them, the propeller guard body10and the repulsion mechanism40constitute a propeller guard2. The flight vehicle1flies by the one or more propellers30each having a vertical rotation axis.

The propeller guard body10is configured to surround the propellers30, and protects the propellers30. The propeller guard body10may be configured to surround not only the propellers30but also a whole of the flight vehicle body20, or may be configured to surround a part of the flight vehicle body20. The following drawings illustrate the propeller guard body10surrounding the whole of the flight vehicle body20.

FIG.2is an example of a side view of the flight vehicle1including the propeller guard2according to the embodiment. The propeller guard2includes the propeller guard body10and the repulsion mechanism40. In the example illustrated inFIG.2, the propeller guard body10includes a coupling frame11, an upper frame13, a lower frame14, and a base frame15. The number of coupling frames11is not limited to one, and can be arbitrarily determined. Note that an intermediate frame parallel to the upper frame13and the lower frame14may be further provided between the upper frame13and the lower frame14. Whether or not to provide the intermediate frame and the number of the coupling frames11and the intermediate frames affect strength of the propeller guard body10when the flight vehicle1comes into contact with an object. Thus, for example, in a case where it is assumed that the flight vehicle1is moved at a high speed, one or a plurality of the intermediate frames may be provided and the number of the coupling frames11may be increased to increase the strength of the propeller guard body10.

The upper frame13is a frame provided on the uppermost surface of the propeller guard body10.

The lower frame14is a frame provided below the upper frame13and substantially parallel to the upper frame13. A motor31for the propeller30is mounted on the lower frame14.

The base frame15is installed below the lower frame14(at the lowermost surface of the propeller guard body10) substantially parallel to the upper frame13, and is a frame to be in contact with an object such as the ground at the time of landing of the flight vehicle1. The base frame15provides stability at the time of landing of the flight vehicle1and protects the bottom of the flight vehicle1. Center points of the upper frame13, the lower frame14, and the base frame15are desirably located on a center axis of the flight vehicle body20to balance the flight vehicle during flight.

The coupling frame11is a frame that couples the upper frame13, the lower frame14, and the base frame15together. The coupling frame11includes a first coupling portion112that couples the upper frame13and the lower frame14together, and a second coupling portion113that couples the lower frame14and the base frame15together. In the example ofFIG.2, the upper frame13, the lower frame14, the base frame15, and the coupling frame11constitute the propeller guard body10configured to surround the propellers30of the flight vehicle body20. The shape of the propeller guard body10illustrated inFIG.2is an example. In addition, for simplicity of explanation, in the following embodiment, as an example, the propeller guard body10has an outer edge that appears circular as viewed from vertically above. However, the propeller guard body10can have any shape.

The repulsion mechanism40includes a first end45and a second end46and is provided to protrude on the propeller guard body10through the first end45. In the example ofFIG.2, the first end45of the repulsion mechanism40is attached to the upper frame13of the propeller guard body10. The second end46of the repulsion mechanism40may be provided to be located outside an outer edge of the propeller guard body10as viewed from vertically above. The repulsion mechanism40includes a mechanism for separating the propeller guard body10from an object in response to contact of the second end46with the object such as an outer wall of the structure51.

FIG.3is an example of a schematic diagram of the repulsion mechanism40. The repulsion mechanism40includes a housing41, a sensor42, a separation member43, and an elastic member44.

The housing41is a box that accommodates the separation member43and the elastic member44therein.

The sensor42is a component that detects contact of the second end46with an object. The sensor42can be implemented by, for example, a mechanical sensor, a sensor that detects electrical contact, an infrared sensor, or the like.

The separation member43is a member connected to the elastic member44.

The elastic member44is a member having elastic force, such as a spring. The elastic member44is compressed and accommodated in the housing41.

When the sensor42detects the contact of the second end46of the repulsion mechanism40with the object, the compression of the elastic member44is released accordingly. The repulsion mechanism40includes a release mechanism of such a mechanism that releases compression of the elastic member44in response to the contact of the second end46with the object. By releasing the compression of the elastic member44, the separation member43protrudes towards the object from the second end46of the repulsion mechanism40, so that the propeller guard body10is separated from the object.

FIG.4illustrates a state in which the flight vehicle1including the propeller guard body10and the repulsion mechanism40according to the embodiment is in contact with a wall surface during movement vertically upward. As illustrated inFIG.4, it is assumed that when the flight vehicle1to which the propeller guard body10is attached is caused to ascend in the structure51, the flight vehicle1discharges air in a D1 direction and moves in an F1 direction, and the second end46of the repulsion mechanism40comes into contact with the wall surface or the like of the structure51. In this case, the sensor42detects contact of the second end46with the wall surface or the like of the structure51, and accordingly, the compression of the elastic member44is released, and the separation member43protrudes toward the wall surface or the like. As a result, the propeller guard body10is separated from the wall surface or the like, and the flight vehicle1instantaneously moves away from the structure51and changes its course in an F2 direction. Thus, it is possible to prevent the flight vehicle1from rotating with a contact point between the propeller guard body10and the wall surface of the structure51as a fulcrum or the flight vehicle1from sticking to the wall surface of the structure51.

Note that the first end45of the repulsion mechanism40may be located at the outer edge of the propeller guard body10as viewed from vertically above. As a result, it is possible to minimize the length of the repulsion mechanism40.

In addition, the second end46of the repulsion mechanism40may be located above the first end45of the repulsion mechanism40. As a result, when the flight vehicle1moves vertically upward, the repulsion mechanism40comes into contact with the wall surface or the like of the structure51before the flight vehicle body20or the propeller guard body10comes into contact with the wall surface or the like of the structure51, and the propeller guard body10can be separated from the wall surface or the like.

The propeller guard2may include a plurality of the repulsion mechanisms40.FIG.5is an example of a top view of the propeller guard2including a plurality of repulsion mechanisms40aand40b. Hereinafter, an example will be described in a case where the plurality of repulsion mechanisms40is provided at equal intervals. In the configuration as inFIG.5, the first repulsion mechanism40aand the second repulsion mechanism40bprovided adjacent to each other may have lengths such that a vertical plane passing through a second end46aof the first repulsion mechanism40aand a second end46bof the second repulsion mechanism40bis located outside the outer edge of the propeller guard body10. InFIG.5, the second end46aof the repulsion mechanism40aand the second end46bof the repulsion mechanism40bprovided adjacent to each other as viewed from vertically above are in contact with the structure51. However, since a boundary of the structure51is outside the propeller guard body10, there is a gap90between the propeller guard body10and the structure51. For that reason, even in a case where the flight vehicle1comes into contact with the wall surface or the like of the structure51from any direction when moving vertically upward, the repulsion mechanism40comes into contact with the wall surface or the like of the structure51before the propeller guard body10comes into contact with the wall surface or the like of the structure51. Thus, even in a case where the propeller guard body10comes into contact with the wall surface or the like of the structure51from any direction, the repulsion mechanism40can separate the propeller guard body from a wall.

In addition, in the above description, an example has been described in which the propeller guard body10includes the repulsion mechanism40; however, the flight vehicle body20may include the repulsion mechanism40. As a result, according to a principle similar to that of the propeller guard2described above, the repulsion mechanism40separates the flight vehicle body20from the wall surface of the structure51, and it is possible to suppress occurrence of rotation of the flight vehicle body20due to contact with an object. The repulsion mechanism40may be provided as a component attachable to the flight vehicle body20or the propeller guard body10, not in a state of being attached to the flight vehicle body20or the propeller guard body10.

REFERENCE SIGNS LIST