Unmanned aerial vehicle and arm connection structure thereof

An arm connection structure for connecting an arm to a body provided in the present invention includes: a connection shaft, a shaft sleeve that can be sleeved on the connection shaft in a manner of rotating relative to the connection shaft, and an elastic member sleeved on the connection shaft. The shaft sleeve is provided with a curved guide slot extending along a peripheral direction of the shaft sleeve, and the connection shaft is provided with a guide block that matches the curved guide slot and that can slide in the curved guide slot. The curved guide slot has a first lock position for locking the arm in an unfolded state, and a second lock position for locking the arm in a folded state. The present invention can make the arm not easily shake in a flight process of an unmanned aerial vehicle, making flight more stable.

CROSS REFERENCE

The present application is a continuation of Chinese Patent NO. 2017208998744, filed on Jul. 24, 2017, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to the field of unmanned rotorcraft technologies, and specifically, to an arm connection structure and an unmanned aerial vehicle using the arm connection structure.

RELATED ART

Unmanned aerial vehicle related technologies home and abroad are rapidly developed, and greatly differ from each other in a plurality of aspects such as the size, the quality, the voyage, the endurance, the flight height, the flight speed, and the task, leading to a large variety of types, wide uses and distinctive features of unmanned aerial vehicles. Based on a flight platform configuration, an unmanned aerial vehicle may be classified into a fixed-wing unmanned aerial vehicle, an unmanned rotorcraft, an unmanned airship, a parasol-wing unmanned aerial vehicle, a flapping-wing unmanned aerial vehicle, or the like. The unmanned rotorcraft is a product of microelectromechanical system integration, and has become the research focus of many laboratories at home and abroad by its advantages such as vertical take-off and landing, free hovering, flexible control and strong adaptabilities to various environments. A common unmanned rotorcraft has at least three rotor shafts, and the rotor shafts are disposed on an arm extending outward relative to a body. Rotation of motors on the shafts drives rotors, to generate a lifting force. A relative rotational speed between different rotors is changed, so that the magnitude of a single-shaft pushing force can be changed, thereby controlling a movement track of the aircraft. However, because the arm of this type of unmanned rotorcraft extends outward relative to the body and is fixed to the body, the arm cannot rotate relative to the body. Consequently, the arm cannot be folded. Such an unmanned rotorcraft has disadvantages of a relatively large volume and inconvenient carriage.

Therefore, an unmanned aerial vehicle whose arm can be folded relative to a body appears. However, this type of unmanned aerial vehicle still has some defects. An arm connection structure adopted in this type of unmanned aerial vehicle makes the unmanned aerial vehicle easily shake in a flight process. Consequently, flight of the unmanned aerial vehicle is unstable.

SUMMARY

Therefore, the technical problem to be resolved in the present invention is to overcome the defect in the prior art that an arm connection structure makes an unmanned aerial vehicle shake in a flight process, leading to unstable flight, and provide an arm connection structure.

Therefore, the present invention adopts the following technical solutions:

an arm connection structure, configured to rotatably connect an arm to a body, and including:

a connection shaft, mounted on the body;

a shaft sleeve, sleeved on the connection shaft, and capable of moving along an axial direction of the connection shaft, where the shaft sleeve can rotate with the arm;

where the shaft sleeve is provided with a curved guide slot extending along a peripheral direction of the shaft sleeve, and the connection shaft is provided with a guide block that matches the curved guide slot and that can slide in the curved guide slot; or

the shaft sleeve is provided with a curved guide slot extending along a peripheral direction of the shaft sleeve, and the connection shaft is provided with a guide block that matches the curved guide slot and that can slide in the curved guide slot; and

an elastic member, where the elastic member is sleeved on the connection shaft, and one end of the elastic member abuts against the shaft sleeve, and the other end abuts against the body, where

the curved guide slot has an extreme position and a first lock position and a second lock position that are located on two sides of the extreme position; when the guide block slides to the first lock position, the arm is in an unfolded state, and when the guide block slides to the second lock position, the arm is in a folded state.

In an embodiment of the present invention, the extreme position is a highest point or a lowest point of the curved guide slot.

In an embodiment of the present invention, the curved guide slot is a smooth curved guide slot.

In an embodiment of the present invention, the curved guide slot is a cam guide slot.

In an embodiment of the present invention, the guide block is cylindrical.

In an embodiment of the present invention, the arm connection structure further includes a socket sleeved on the shaft sleeve, and the socket is fixedly connected to the arm; and

a shape of an inner wall of the socket matches a shape of an outer wall of the shaft sleeve, so that the socket cannot rotate relative to the shaft sleeve.

To solve the technical problem thereof, the present invention further provides an unmanned aerial vehicle, including a body, an arm, and an arm connection structure configured to rotatably connect the arm to the body, where the arm connection structure includes:

a connection shaft, mounted on the body;

a shaft sleeve, sleeved on the connection shaft, and capable of moving along an axial direction of the connection shaft, where the shaft sleeve can rotate with the arm;

where the shaft sleeve is provided with a curved guide slot extending along a peripheral direction of the shaft sleeve, and the connection shaft is provided with a guide block that matches the curved guide slot and that can slide in the curved guide slot; or

the shaft sleeve is provided with a curved guide slot extending along a peripheral direction of the shaft sleeve, and the connection shaft is provided with a guide block that matches the curved guide slot and that can slide in the curved guide slot; and

an elastic member, where the elastic member is sleeved on the connection shaft, and one end of the elastic member abuts against the shaft sleeve, and the other end abuts against the body, where

the curved guide slot has an extreme position and a first lock position and a second lock position that are located on two sides of the extreme position; when the guide block slides to the first lock position, the arm is in an unfolded state, and when the guide block slides to the second lock position, the arm is in a folded state.

In an embodiment of the present invention, the extreme position is a highest point or a lowest point of the curved guide slot.

In an embodiment of the present invention, the curved guide slot is a smooth curved guide slot.

In an embodiment of the present invention, the curved guide slot is a cam guide slot.

In an embodiment of the present invention, the guide block is cylindrical.

In an embodiment of the present invention, the arm connection structure further includes a socket sleeved on the shaft sleeve, and the socket is fixedly connected to the arm; and

a shape of an inner wall of the socket matches a shape of an outer wall of the shaft sleeve, so that the socket cannot rotate relative to the shaft sleeve.

The technical solutions of the present invention have the following advantages:

According to an arm connection structure provided in the present invention, a cam guide slot and a guide block are provided; when an arm needs to be switched between unfolded and folded states, the arm is rotated to drive a shaft sleeve or a connection shaft linked with the arm, so that the guide block slides in the cam guide slot based on a shape of the cam guide slot; when the guide block slides to a first lock position or a second lock position of the cam guide slot, the arm is locked in the unfolded state or the folded state under the effect of an elastic member, so that the arm completes switching and locking between the unfolded state and the folded state. Regarding this manner in which the guide block slides in the cam guide slot to implement state switching, because the guide block slides based on the shape of the cam guide slot, and a slide track of the guide block is completely and strictly limited by the shape of the cam guide slot, sliding of the guide block in the entire switching process is stable, and the unmanned aerial vehicle does not easily shake in the flight process, thereby making the flight more stable.

DESCRIPTION OF REFERENCE SIGNS

DETAILED DESCRIPTION

The following clearly and completely describes the technical solutions of the present invention with reference to the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present invention, rather than all the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that orientation or position relationships indicated by terms such as “center”, “on”, “below”, “left”, “right”, “vertical”, “horizontal”, “inside”, and “outside” are based on orientation or position relationships shown in the accompanying drawings, and are used only for facilitating describing the present invention and simplifying the description, rather than indicating or implying that the mentioned apparatus or component needs to have a specific orientation, and needs to be constructed and operated in the specific orientation, and therefore the terms cannot be understood as a limitation to the present invention. Moreover, the terms “first”, “second”, and “third” are used only for descriptive purposes, and cannot be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that unless otherwise explicitly stipulated and defined, the terms “mounting”, “connected”, and “connection” should be understood in a broad sense. For example, the connection may be a fixed connection, a detachable connection, or an integral connection; the connection may be a mechanical connection, or an electric connection; the connection may be a direct connection, an indirect connection through an intermediary, or internal communication between two components. For a person of ordinary skill in the art, specific meanings of the foregoing terms in the present invention may be understood based on specific cases.

In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other provided that they do not form a conflict with each other.

As shown inFIG. 1, an arm connection structure provided in this embodiment includes a connection shaft3, a shaft sleeve4, an elastic member7and a socket8. Two ends of the connection shaft3are fixedly connected to a body of an unmanned aerial vehicle. The socket8is disposed in an arm of the unmanned aerial vehicle, and can rotate with the arm. The shaft sleeve4is sleeved on the connection shaft3, and is located in the socket8. The shaft sleeve4rotates with the socket8. In an embodiment of the present invention, the shape of an inner wall of the socket8matches the shape of an outer wall of the shaft sleeve4, so that the socket8cannot rotate relative to the shaft sleeve4. In this embodiment, an outer wall of the socket8tightly matches a hole wall of the arm, to implement a fixed connection between the socket8and the arm. An outer surface of the shaft sleeve4is set to a non-cylindrical surface obtained by cutting a cylinder by a plane parallel to an axial direction of the connection shaft3. Correspondingly, the inner wall of the socket8is also a non-cylindrical surface having the same shape, so that relative rotation cannot be performed between the shaft sleeve4and the socket8.

In addition, the shaft sleeve4can also slide along the axial direction of the connection shaft3. The elastic member7is also disposed in the socket8. One end of the elastic member7abuts against the shaft sleeve4, and the other end of the elastic member7abuts against the arm. In this embodiment, the elastic member7is a spring.

In other possible embodiments, alternatively, the connection shaft3is fixedly connected to the arm, and the shaft sleeve4is linked with the body2.

In this embodiment, the shaft sleeve4is provided with a curved guide slot5extending along a peripheral direction of the shaft sleeve4, and the connection shaft3is correspondingly provided with a guide block6that matches the curved guide slot5and that can slide in the curved guide slot5. In other possible embodiments, alternatively, the connection shaft is provided with a curved guide slot extending along a peripheral direction thereof, and the shaft sleeve is correspondingly provided with a guide block that matches the curved guide slot and that can slide in the curved guide slot. In an embodiment of the present invention, the curved guide slot5is a smooth cam guide slot. In other possible embodiments, the curved guide slot5may also be a parabola-like smooth curved slot, a “W”-like smooth curved slot, a smooth curved slot with two ends being smoothly transitioned, and a middle part being provided with a section of straight line, or the like. The curved guide slot5is set to a smooth curved slot, so that resistance during sliding of the guide block6in the curved guide slot5can be reduced, thereby making the sliding of the guide block6smoother.

In an embodiment of the present invention, the curved guide slot5includes an extreme position and a first lock position and a second lock position that are respectively disposed on two sides of the extreme position. When the guide block6is located at the first lock position, the arm connection structure locks the arm in an unfolded state. When the guide block6is located at the second lock position, the arm connection structure locks the arm in a folded state. The extreme position may be a highest point of the curved guide slot5, or a lowest point of the curved guide slot5.

In this embodiment, there is an extreme position between the first lock position and the second lock position. When the guide block6slides from one lock position to across the extreme position, the guide block6is enabled, by means of the effect of an elastic restoring force of the elastic member7, to automatically slide into the another lock position. When the guide block slides from one lock position to the extreme position, the extreme position enables the guide block to rapidly slide to the another lock position, thereby preventing the guide block6from residing at other transitional positions. When the guide block6resides at other transitional positions, the arm in unfolded state is unstable during flight of an unmanned aerial vehicle. Consequently, the aim shakes, and even returns to the folded state, making the unmanned aerial vehicle drop down, leading to explosion.

In an embodiment of the present invention, the first lock position and the second lock position are respectively located on two ends of the curved guide slot5. The first lock position and the second lock position are respectively disposed on two ends of a cam guide slot5, so that the curved guide slot5can be fully used, and has no redundant and unused parts, thereby reducing processing costs and processing steps. In other possible embodiments, the first lock position or the second lock position may also be disposed at an intermediate position of the curved guide slot5, and an extreme position is disposed on either side of the first lock position or the second lock position. For example, when the curved guide slot5is a “W”-like smooth curved slot, two extreme positions are respectively two “W”-like lowest positions.

When the arm needs to be switched between unfolded and folded states, the arm is rotated to drive the shaft sleeve4or the connection shaft3linked with the arm to rotate, so that the guide block6slides in the curved guide slot5based on the shape of the curved guide slot5. When the guide block6slides to the first lock position or the second lock position of the curved guide slot5, the arm is locked in the unfolded state or the folded state under the effect of the elastic restoring force of the elastic member, thereby completing switching and locking between the unfolded state and the folded state by the arm. Regarding this manner in which the guide block6slides in the curved guide slot5to switch between unfolded and folded states of the arm, because the guide block6slides based on the shape of the curved guide slot5, and a slide track of the guide block6is completely and strictly limited by the shape of the curved guide slot5, sliding of the guide block6in the entire switching process is stable, and the unmanned aerial vehicle does not easily shake in the flight process, thereby making movement execution in the process of switching between the unfolded and folded states of the arm more reliable, and making the flight more stable.

In this embodiment, the curved guide slot5is formed on a peripheral wall of the shaft sleeve4, and the guide block6is formed on a peripheral wall of the connection shaft3. The curved guide slot5and the guide block6are respectively formed on the peripheral wall of the shaft sleeve4or the peripheral wall of the connection shaft3, so that the peripheral wall of the curved guide slot5is completely closed, and a movement track of the guide block6matching the curved guide slot5in the curved guide slot5is fixed. In this way, the following problem is avoided: in the process of switching between the unfolded and folded states, the guide block6does not move based on the movement track in the curved guide slot5. In this way, the guide block6does not depart from the movement track on the curved guide slot5, thereby making movement execution in the state switching process more reliable.

In an embodiment of the present invention, the guide block6is a cylindrical block. The guide block6is set to a cylindrical block, so that sliding of the guide block6along the curved guide slot5is smoother. In other possible embodiments, the guide block6may alternatively be a block having another shape and a smooth curved surface.

When the arm is in the folded state, the guide bloc6is located at the second lock position of the curved guide slot5. In this case, if the unmanned aerial vehicle needs to be used, the arm of the unmanned aerial vehicle needs to be adjusted to the unfolded state from the folded state. Specifically, first, the arm is rotated by using an external force, the arm is linked with the socket8, and the socket8is linked with the shaft sleeve4, so that the shaft sleeve4rotates relative to the connection shaft3fixedly connected to the body2, making the guide block6disposed on the connection shaft3slide along the curved guide slot5disposed on the shaft sleeve4. The curved guide slot5is a cam guide slot. A highest point of the cam guide slot is an extreme position of the curved guide slot5. Two lowest points of the cam guide slot are respectively the first lock position and the second lock position. In this case, the shaft sleeve4overcomes the elastic restoring force of the elastic member7under the effect of the external force, to move along the axial direction of the connection shaft3. The guide block6departs from the second lock position, and moves towards the extreme position along the curved guide slot5. When the guide block6crosses the extreme position of the curved guide slot5, the elastic restoring force applied by the elastic member7to the shaft sleeve4can make the guide block6automatically slide into the first lock position, and under the effect of the elastic restoring force of the elastic member7, the guide block6is locked at the first lock position, thereby locking the arm in the unfolded state. Similarly, when the arm of the unmanned aerial vehicle is in the unfolded state, the guide block6is located at the first lock position of the curved guide slot5. In this case, if the unmanned aerial vehicle needs to be folded, the arm is rotated in the same manner, so that the guide block6departs from the first lock position, and overcomes the elastic restoring force of the elastic member7to move towards the extreme position. When crossing the extreme position, under the effect of the elastic restoring force of the elastic member7, the guide block6can automatically slide into the second lock position, and is locked at the second lock position by the elastic restoring force of the elastic member7, thereby locking the arm in the folded state.

This embodiment provides an unmanned aerial vehicle, including a body2and an arm1, and further including the foregoing arm connection structure connecting the body2to the arm1. Because the unmanned aerial vehicle adopts the foregoing arm connection structure, the unmanned aerial vehicle does not easily shake in the flight process, thereby making movement execution in the process of switching between the unfolded and folded states of the arm more reliable, and making the flight more stable.

Apparently, the foregoing embodiments are merely examples for clear description, rather than a limitation to implementations. For a person of ordinary skill in the art, other changes or variations in different forms may also be made based on the foregoing description. All implementations do not need to be listed herein. Obvious changes or variations that are derived therefrom still fall within the protection scope of the creation of the present invention.