A folding device for the arms of a drone

Abstract

The application provides a machine arm folding device of a unmanned aerial vehicle, and relates to the technical field of unmanned aerial vehicles.A machine arm folding device of a unmanned aerial vehicle comprises a fixing seat, wherein an arc-shaped sliding rail is arranged on the fixing seat, an ear seat is slidingly matched with the sliding rail, the ear seat is rotationally connected with the fixing seat and is connected with a torsional spring, a hollow machine arm is fixed to the end of the ear seat, a locking pin is slidingly arranged in the machine arm, one end of the locking pin can be inserted into a locking hole on the sliding rail, and a lock spring is arranged in the machine arm and is used for forcing the locking pin to be inserted into the locking hole.A ratchet wheel is rotationally arranged on the side wall of the fixing seat, a pawl matched with the ratchet wheel is rotationally arranged on the side wall of the machine arm, a sliding block used for pushing away the pawl is slidingly arranged on the side wall of the machine arm, the sliding block is connected with a first blocking ring on the locking pin through a pull rope, and a piezoelectric inertial driver is installed at the end of the machine arm away from the fixing seat, wherein an output shaft of the piezoelectric inertial driver is fixedly connected with the first blocking ring.When the driver is powered, the locking pin is driven to exit the locking hole and the sliding block is driven to push away the pawl through the pull rope, so that the locking of the folding direction of the machine arm is released.

Description

Technical Field

[0001] This application relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a UAV arm folding device. Background Technology

[0002] Multirotor drones have been widely used in aerial photography, surveying, logistics delivery, and military reconnaissance due to their advantages such as vertical takeoff and landing, flexible hovering, and ease of operation. To meet flight stability requirements, the arms of multirotor drones are typically designed as long structures extending in all directions to increase the distance between the propellers and improve flight efficiency.

[0003] Related technologies can be found in Chinese Invention Patent No. CN118833434A. This invention discloses a rotorcraft drone arm folding mechanism, including a fixed base with multiple longitudinally located arc-shaped slide rails evenly spaced along the circumference. Each slide rail has a slidingly fitted lug that is rotatably connected to the fixed base. A torsion spring connects the lug to the fixed base. A hollow arm is fixedly connected to the end of the lug away from the slide rail, and a locking mechanism is provided inside the arm to fix it to the slide rail. This rotorcraft drone arm folding mechanism allows the arm to rotate vertically along the slide rails, achieving a folding effect, reducing horizontal space occupation, and resulting in a compact structure after folding, which is beneficial for drone storage and transportation. During use, the external constraints on the arm are removed, the torsion spring potential energy is released, driving the arm to unfold horizontally, and the locking mechanism locks the arm in place. It is convenient to use and highly reliable.

[0004] However, existing rotorcraft drone arm folding mechanisms still have the following shortcomings: their locking function relies entirely on the engagement of a locking pin with a single locking hole. When the drone is subjected to continuous vibration or accidental impact during transportation, the locking pin may accidentally disengage from the locking hole due to spring fatigue or vibration inertia, causing the arm to fold on its own when not in operation. At the same time, if manual folding and storage is required on the ground, the operator must use their fingers to overcome the spring force of the locking pin to unlock it, which is laborious. Furthermore, if the locking pin fails, the arm may suddenly fold during flight, causing a crash. Summary of the Invention

[0005] This application provides a folding arm device for a drone, which solves the problems that the locking function relies on a locking pin and a single locking hole, and that the locking pin may fall off under continuous vibration or accidental impact, leading to a crash, and that folding and storing is troublesome.

[0006] The technical solution adopted in the embodiments of this application is as follows: In a first aspect, embodiments of this application provide a folding arm device for a drone, comprising a fixed base for fixedly connecting to the drone body. The fixed base has multiple longitudinally extending arc-shaped slide rails spaced circumferentially. Each arc-shaped slide rail has a sliding lug, which is rotatably connected to the fixed base. A hollow arm is fixedly connected to the end of the lug away from the fixed base. A locking pin is slidably disposed within the arm along its length. The end of the locking pin near the fixed base is used to insert into a locking hole formed on the arc-shaped slide rail. The arm also has a mechanism for forcing the locking pin to... A locking spring moves towards the fixed base. A ratchet disc is rotatably mounted on the side wall of the fixed base, and a pawl that cooperates with the ratchet disc is rotatably mounted on the side wall of the arm. A slider for pushing open the pawl is also slidably mounted on the side wall of the arm. A piezoelectric inertial actuator is installed at the end of the arm away from the fixed base. The output shaft of the piezoelectric inertial actuator is fixedly connected to the first retaining ring. When the piezoelectric inertial actuator is energized, it drives the locking pin to move away from the fixed base, causing the locking pin to exit the locking hole and drive the slider to push open the pawl through the pull cable, thereby releasing the locking of the arm's folding direction.

[0007] By adopting the above technical solution, the ratchet disc is set on the side wall of the fixed base, and the pawl and slider are installed on the side wall of the arm. A piezoelectric inertial actuator is used as the power source. At the same time, the movement of the locking pin and the sliding of the slider are linked by a cable. The ratchet disc and pawl form a one-way mechanical lock. Even if the locking pin accidentally comes out of the lock hole due to vibration, the pawl can still prevent the arm from rotating in the folding direction, forming a double redundancy safety guarantee. The piezoelectric inertial actuator only consumes pulse power when switching states. After reaching the unlock position, it maintains the state by relying on internal static friction, achieving zero power consumption. This significantly reduces the overall power consumption of the UAV and avoids the coil overheating problem caused by the electromagnet being energized for a long time. At the same time, the cable linkage structure allows the action of the locking pin coming out of the lock hole to complete the pawl unlocking simultaneously, without the need for additional control logic. This achieves the effects of improving the operation response speed and providing double redundancy safety guarantee.

[0008] In one optional implementation, the arc-shaped slide rail has two locking holes spaced 90 degrees apart along its arc direction. These are a first locking hole corresponding to the horizontally extended state of the machine arm and a second locking hole corresponding to the vertically folded state of the machine arm. The two locking holes are connected by a shallow groove with a depth less than the depth of the locking holes. The end of the locking pin near the fixed seat slides along the shallow groove during the rotation of the machine arm.

[0009] By adopting the above technical solution, the first locking hole corresponds to the horizontal unfolding position, and the second locking hole corresponds to the vertical folding position, so that the drone arm can be firmly locked in the vertical direction when it is stored and transported, avoiding the arm from being accidentally thrown out due to transportation bumps; the shallow groove is less than the depth of the locking hole, ensuring that the locking pin will not completely exit the slide rail surface during rotation, but will smoothly transition along the shallow groove, which not only plays a guiding role, but also prevents the locking pin from rigidly colliding with the edge of the slide rail, thereby improving the smoothness of operation and locking reliability of the mechanism throughout the entire stroke.

[0010] In one optional implementation, the ratchet disc is coaxially disposed around the end of the rotating shaft that protrudes from the side wall of the fixed seat. The teeth of the ratchet disc are configured to allow the lug to rotate in the arm unfolding direction and prevent the lug from rotating in the arm folding direction. The pawl is mounted on the outer side wall of the arm root near the fixed seat, and the pawl is provided with a spring that presses its end against the teeth of the ratchet disc. The slider is slidably mounted on a guide rail on the same outer side wall of the arm. The slider is fixedly connected to the pawl. When the slider slides away from the fixed seat, the slider causes the pawl to disengage from the ratchet disc.

[0011] By adopting the above technical solution, the fixed connection between the slider and the pawl allows the pawl to move synchronously when the slider moves, making the transmission of unlocking commands more direct. The pawl relies on its own spring to press against the ratchet disc, and can quickly resume engagement after the slider resets, ensuring that the one-way locking function automatically takes effect after the folding or unfolding action is completed, without the need for additional control. In addition, arranging the pawl and slider on the outer wall of the arm rather than the side wall of the fixed seat allows the entire ratchet and pawl mechanism to rotate with the lug, simplifying the cable routing path, reducing assembly difficulty and wear risk, and achieving automatic engagement and unlocking through mechanical structure, thus simplifying the structure.

[0012] In one optional implementation, a transverse partition is fixedly installed at one end of the arm near the fixed seat, dividing the inner cavity of the arm into a front cavity near the fixed seat and a rear cavity away from the fixed seat; one end of the locking pin near the fixed seat passes through the transverse partition and extends into the front cavity, and a second retaining ring is fixedly installed on the locking pin within the front cavity; a locking spring is sleeved on the locking pin and located between the transverse partition and the second retaining ring; the locking spring is a compression spring, and when the locking pin moves away from the fixed seat, the second retaining ring compresses the locking spring.

[0013] By adopting the above technical solution, the locking spring is located between the transverse partition and the second retaining ring. When the locking pin moves away from the fixed seat, the second retaining ring compresses the locking spring to store potential energy. When the piezoelectric inertial actuator is de-energized, the locking spring releases its potential energy to push the locking pin to automatically reset and insert into the lock hole. The transverse partition restricts the locking spring in the front cavity, preventing the locking spring from bending or shifting during compression, ensuring the straightness of the locking pin's movement, and achieving the effect of improving the reliability and safety of the locking mechanism.

[0014] In one alternative implementation, a push switch is embedded on the lower side of the outer wall at the root of the arm. A connecting rod is connected to the inner side of the push switch. One end of the connecting rod is fixedly connected to the push switch, and the other end is fixedly connected to the second retaining ring. When the push switch is pressed, the end of the connecting rod directly pushes the second retaining ring, which further drives the locking pin to move away from the fixed seat, so that the end of the locking pin disengages from the lock hole.

[0015] By adopting the above technical solution, the push switch is rigidly connected directly to the second retaining ring via a connecting rod, forming a purely mechanical emergency unlocking channel. When the operator manually presses the push switch on the outer wall of the arm, the connecting rod directly pushes the second retaining ring away from the fixed seat. The second retaining ring drives the locking pin out of the lock hole. At the same time, because the movement of the locking pin will pull the slider through the cable to push open the pawl, a single press can simultaneously release the locking pin and ratchet lock, thereby improving usability and human-machine interaction in emergency situations and facilitating operation.

[0016] In one alternative implementation, the piezoelectric inertial actuator is fixedly mounted at the bottom of the rear cavity of the arm, and its output shaft is coaxially fixedly connected to the end of the locking pin away from the fixed seat; after receiving the pulse signal from the flight control system, the piezoelectric inertial actuator moves its output shaft stepwise, and maintains its current position by relying on internal static friction after power is cut off.

[0017] By adopting the above technical solution, the working principle of the piezoelectric inertial actuator determines that it only consumes electrical energy to complete the stepping movement when it receives a pulse signal. Once the output shaft reaches the target position, the actuator can maintain the position of the output shaft by static friction without any electrical energy. This means that during the flight of the drone, the arm locking mechanism does not need to consume any battery power at all, and when folding or unfolding is required, only a very short pulse power supply is needed to complete the state switching. For drones with limited battery capacity, this achieves the effect of saving considerable energy per flight.

[0018] In one alternative implementation, one end of the cable is fixedly connected to the second retaining ring, and the other end of the cable is fixedly connected to the slider.

[0019] By adopting the above technical solution, the second retaining ring is an actively moving component during the unlocking process of the locking pin. When the cable is fixed to the second retaining ring and the locking pin moves away from the fixed seat, the cable is pulled synchronously, thereby driving the slider to slide and push open the pawl. Conversely, when the locking spring pushes the locking pin to reset, the cable loosens and the slider resets under the action of the pawl's own spring, thus achieving the effect of extending the service life of the cable and ensuring the consistency of long-term operation.

[0020] In one alternative implementation, the outer wall of the arm is provided with a streamlined protective cover for covering the pawl and slider.

[0021] By adopting the above technical solution, the protective cover completely encloses the pawl, slider, and guide rail, effectively isolating them from external pollutants such as dust, sand, and raindrops, reducing the likelihood of the sliding pair jamming due to foreign object intrusion. Simultaneously, the streamlined design of the protective cover conforms to the aerodynamic contours of the boom, reducing flight drag. During drone emergency landings or transportation, the protective cover also provides mechanical protection, preventing the pawl from deforming or breaking due to accidental collisions, thus enhancing the folding mechanism's adaptability and long-term reliability in harsh environments.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. By mounting the ratchet disc on the side wall of the fixed base and the pawl and slider on the side wall of the arm, and coordinating with the piezoelectric inertial actuator and cable linkage, a dual redundant locking system of locking pin and pawl is achieved. Even if the locking pin accidentally disengages from the locking hole due to vibration, the pawl can still prevent the arm from rotating in the folding direction, significantly improving flight safety. At the same time, the piezoelectric inertial actuator only consumes pulse power during state switching, and maintains its position with zero power consumption by static friction after reaching the desired position, reducing flight endurance consumption. 2. Two locking holes are spaced 90 degrees apart on the slide rail and connected to a shallow groove, allowing the arm to be reliably locked in both horizontally extended and vertically folded positions, preventing the arm from accidentally swinging out during transport. The shallow groove is less deep than the locking holes, ensuring a smooth transition of the locking pin during rotation and reducing the risk of jamming. In addition, a push-button switch embedded at the base of the arm is directly connected to the second retaining ring via a connecting rod, forming a purely mechanical emergency unlocking channel. A single press can simultaneously release the locking pin and the pawl, making operation intuitive and effortless. 3. The pawl and slider are fixedly connected and positioned on the outer wall of the arm, rotating together with the lug, reducing assembly difficulty and wear risk. A transverse partition confines the locking spring within the front cavity, ensuring the linearity of the locking pin's movement. A streamlined protective cover completely encloses the pawl and slider, isolating them from sand and raindrops, reducing flight drag, and preventing collision deformation, thus improving the folding mechanism's adaptability to harsh environments and its long service life. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of a drone's arm folding device.

[0024] Figure 2 This is a schematic diagram of the internal structure of the machine arm.

[0025] Explanation of reference numerals in the attached drawings: 1. Fixed base; 2. Arc-shaped slide rail; 3. Ear seat; 4. Machine arm; 5. Shallow groove; 6. Protective cover; 7. Locking pin; 8. Locking spring; 9. Ratchet disc; 10. Pawl; 11. Slider; 12. First retaining ring; 13. Second retaining ring; 14. Piezoelectric inertial actuator; 15. Transverse partition; 16. Push switch; 17. Connecting rod. Detailed Implementation

[0026] The present application will be further described in detail below with reference to all the accompanying drawings in the embodiments of the present application.

[0027] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. "Fixed connection" refers to a connection where the relative positional relationship remains unchanged after the connection. It should be understood that when component A is fixedly connected to component C via component B, changes in the relative positional relationship due to deformation of components A, B, and C are permissible. The integrated structure obtained by the two components through a one-piece molding process means that during the formation of one of the two components, that component is connected to the other component, without requiring further processing (such as bonding, welding, snap-fit ​​connections, or screw connections) to connect the two components.

[0028] The directional terms mentioned in the embodiments of this application, such as "upper", "lower", "side", etc., are only for reference to the direction of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this application, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0029] The term "multiple" refers to at least two. The term "more than" includes the stated number. The term "and / or" describes a relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0030] This application discloses a folding arm device for a drone.

[0031] Reference Figure 1 A folding arm device for a drone includes a mounting base 1 for fixedly connecting to the drone body. The mounting base 1 is generally annular and made of carbon fiber composite material to ensure sufficient structural strength and lightweight requirements.

[0032] The lower end face of the fixed base 1 is provided with four longitudinally extending arc-shaped slide rails 2 evenly spaced along the circumference. The arc of each arc-shaped slide rail 2 is 90 degrees. On the outer side of each arc-shaped slide rail 2, an ear seat 3 is provided. The lower end of the ear seat 3 is provided with a groove that matches the cross-sectional shape of the slide rail, so that the ear seat 3 can slide back and forth along the arc direction of the slide rail.

[0033] The upper end of the ear seat 3 is rotatably connected to the fixed seat 1 via a horizontally arranged rotating shaft. The rotating shaft passes through the side wall of the fixed seat 1 in a horizontal direction, and both ends of the rotating shaft extend beyond the two ear plates of the ear seat 3, respectively. A shaft cap is coaxially fixed at the extended end, and the shaft cap is used to limit the axial movement of the rotating shaft.

[0034] A hollow arm 4 is fixedly connected to the end of the ear mount 3 away from the fixed base 1. The arm 4 is made of carbon fiber square tubing, and its interior forms a hollow cavity along its length. The distal end of the arm 4 is used to mount the propeller assembly of the rotor motor.

[0035] Reference Figure 1 and Figure 2 Inside the inner cavity of the arm 4, a locking pin 7 is slidably disposed along the length of the arm 4. The locking pin 7 is a slender cylindrical rod, with one end near the fixed base 1 passing through the front end wall of the ear base 3, for insertion into a locking hole opened on the arc-shaped slide rail 2.

[0036] The end of the locking pin 7 away from the fixed base 1 extends rearward to the rear of the inner cavity of the arm 4, and a first retaining ring 12 is fixedly provided at the end of the locking pin 7 away from the fixed base 1. A locking spring 8 is also provided in the inner cavity of the arm 4, which is used to force the locking pin 7 to move towards the fixed base 1, so that the locking pin 7 always tends to insert into the lock hole.

[0037] A ratchet disc 9 is rotatably mounted on the side wall of the fixed base 1. The ratchet disc 9 is coaxially mounted around the end of the rotating shaft that passes through the side wall of the fixed base 1 via a one-way bearing, that is, the ratchet disc 9 surrounds the rotating shaft and the rotation of the ratchet disc 9 does not interfere with the rotation of the rotating shaft.

[0038] The ratchet disc 9 has unidirectional teeth, which allow the lug 3 to rotate in the unfolding direction of the arm 4 while preventing the lug 3 from rotating in the folding direction of the arm 4. Correspondingly, a pawl 10 is movably mounted on the side wall of the arm 4.

[0039] Pawl 10 is mounted on the outer wall of arm 4. The end of pawl 10 presses against the tooth surface of ratchet disc 9 under the action of its own spring, thus forming a one-way lock. When the lug 3 rotates together with arm 4, pawl 10 slides on the back of the teeth of ratchet disc 9, allowing rotation in the unfolding direction. However, if an attempt is made to rotate in the folding direction, the end of pawl 10 will engage in the tooth groove of ratchet disc 9, preventing further rotation.

[0040] A slider 11 is also slidably mounted on the same outer side wall of the arm 4. The slider 11 is mounted on a linear guide rail arranged along the length of the arm 4 and can slide towards or away from the fixed base 1. The slider 11 is fixedly connected to the pawl 10.

[0041] When the slider 11 slides away from the fixed base 1, the slider 11 drives the pawl 10 to move together, so that the end of the pawl 10 disengages from the tooth surface of the ratchet disk 9, thereby releasing the lock on the folding direction.

[0042] The slider 11 is linked to the locking pin 7 near the fixed base 1 via a flexible cable. One end of the cable is fixedly connected to the second retaining ring 13, and the other end is fixedly connected to the slider 11. The cable is covered with a wear-resistant sheath.

[0043] A piezoelectric inertial actuator 14 is installed at one end of the arm 4 away from the fixed base 1. The piezoelectric inertial actuator 14 contains a stack of piezoelectric ceramics and a mass block.

[0044] The output shaft of the piezoelectric inertial actuator 14 is arranged along the length of the arm 4 and is fixedly connected to the first retaining ring 12. The power supply lead of the piezoelectric inertial actuator 14 is led to the UAV's flight control system along the wire groove on the inner wall of the arm 4. When the flight control system sends a pulse signal to the piezoelectric inertial actuator 14, the piezoelectric element inside the actuator rapidly extends or contracts, causing the output shaft to move a certain distance away from the fixed base 1 through inertial impact. After reaching the target position, the actuator is de-energized, and the static friction inside it can keep the position of the output shaft unchanged, without the need for continuous power supply. Conversely, when locking is required, the flight control system sends a reverse pulse or uses the spring force of the locking spring 8 to reset the output shaft.

[0045] A transverse partition 15 is fixedly installed at one end of the arm 4 near the fixed base 1. The transverse partition 15 is perpendicular to the length direction of the arm 4, and its periphery is sealed and fixed to the inner wall of the arm 4, dividing the inner cavity of the arm 4 into a front cavity near the fixed base 1 and a rear cavity away from the fixed base 1.

[0046] One end of the locking pin 7 near the fixed base 1 passes through the central guide hole on the transverse partition 15 and extends into the front cavity. Inside the front cavity, a second retaining ring 13 is fixedly sleeved on the locking pin 7, and the second retaining ring 13 is located on the side of the transverse partition 15 near the fixed base 1. The locking spring 8 is a compression spring, sleeved on the locking pin 7, and located between the transverse partition 15 and the second retaining ring 13.

[0047] When the locking pin 7 moves away from the fixed base 1, the second retaining ring 13 also moves away from the fixed base 1, thereby compressing the locking spring 8 and storing elastic potential energy. When the locking pin 7 needs to be reset, the locking spring 8 releases its potential energy and pushes the second retaining ring 13 towards the fixed base 1, thereby causing the locking pin 7 to be reinserted into the lock hole.

[0048] Reference Figure 1 On the arc-shaped slide rail 2, two locking holes are opened at ninety-degree intervals along its arc direction. The first locking hole corresponds to the horizontally unfolded state of the machine arm 4, and the second locking hole corresponds to the vertically folded state of the machine arm 4.

[0049] Reference Figure 1 and Figure 2 The two locking holes are connected by a shallow groove 5, which is less than the depth of the locking holes. The locking pin 7 slides along the shallow groove 5 during the rotation of the arm 4. The shallow groove 5 acts as a guide to prevent the locking pin 7 from completely exiting the slide rail surface during rotation.

[0050] A push-button switch 16 is embedded on the lower side of the outer wall at the root of the arm 4. The push-button switch 16 is a mechanical button, and a rigid connecting rod 17 is connected to its inner side.

[0051] One end of the connecting rod 17 is fixedly connected to the push switch 16, and the other end is fixedly connected to the second retaining ring 13. When the operator presses the push switch 16, the connecting rod 17 directly pushes the second retaining ring 13 to move away from the fixed base 1. The second retaining ring 13 drives the locking pin 7 out of the lock hole. At the same time, the locking pin 7 pulls the slider 11 through the cable to push open the pawl 10, thereby realizing purely mechanical emergency unlocking.

[0052] A streamlined protective cover 6 is provided on the outer wall of the robotic arm 4. The protective cover 6 is made of carbon fiber, and its inner cavity completely covers the pawl 10, the slider 11 and the guide rail. The edge of the protective cover 6 is sealed and fitted to the outer wall of the robotic arm 4.

[0053] The outer surface of the protective shield 6 is designed as a smooth, streamlined curved surface to reduce air resistance during flight.

[0054] The implementation principle of the unmanned aerial vehicle (UAV) arm folding device in this application embodiment is as follows: In the initial state, the arm 4 is in a horizontally unfolded position, the locking pin 7 is inserted into the first locking hole, the locking spring 8 is at its natural length, and the pawl 10 engages the ratchet disc 9 under the action of the spring, so the arm 4 cannot rotate in the folding direction.

[0055] When folding is required, the flight control system sends a pulse signal to the piezoelectric inertial actuator 14. The actuator output axis moves stepwise away from the fixed base 1, pulling the locking pin 7 out of the first locking hole. At the same time, the locking pin 7 pulls the slider 11 through the cable. The slider 11 drives the pawl 10 to disengage from the ratchet disk 9. At this time, the folding direction lock of the arm 4 is completely released. The operator manually rotates the lug 3 downwards, and the arm 4 rotates 90 degrees clockwise along the arc-shaped slide rail 2. The locking pin 7 slides along the shallow groove 5 to the position of the second locking hole. At this time, the locking spring 8 is used to reset, and the locking pin 7 is inserted into the second locking hole.

[0056] In case of electrical failure, the operator can directly press the push switch 16 at the base of the 4th arm to manually unlock it by pushing the second retaining ring 13 through the connecting rod 17. The entire mechanism significantly improves the reliability, safety, and ease of use of the 4th arm folding device through the double redundancy of the ratchet and locking pin 7, the zero power consumption of the piezoelectric actuator, and the mechanical emergency channel of the push switch 16.

[0057] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other, and any combination of features in different embodiments is also within the protection scope of this application. That is to say, the multiple embodiments described above can also be arbitrarily combined according to actual needs.

[0058] It should be noted that all the above-mentioned figures are exemplary illustrations of this application and do not represent the actual size of the product. Furthermore, the dimensional proportions between the components in the figures are not intended to limit the actual product of this application. The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A folding arm device for a drone, comprising a fixed base (1) for fixed connection with the drone body, wherein the fixed base (1) is provided with a plurality of longitudinally extending arc-shaped slide rails (2) spaced circumferentially, and each arc-shaped slide rail (2) is slidably fitted with an ear seat (3), the ear seat (3) being rotatably connected to the fixed base (1), and a hollow arm (4) is fixedly connected to the end of the ear seat (3) away from the fixed base (1), wherein a locking pin (7) is slidably provided inside the arm (4) along its length direction, the end of the locking pin (7) near the fixed base (1) being used to insert into a locking hole opened on the arc-shaped slide rail (2), and a locking spring (8) is also provided inside the arm (4) for forcing the locking pin (7) to move towards the fixed base (1), characterized in that: A ratchet disc (9) is rotatably mounted on the side wall of the fixed base (1), and a pawl (10) that cooperates with the ratchet disc (9) is rotatably mounted on the side wall of the arm (4). A slider (11) for pushing open the pawl (10) is also slidably mounted on the side wall of the arm (4). A piezoelectric inertial actuator (14) is installed at the end of the arm (4) away from the fixed base (1). The output shaft of the piezoelectric inertial actuator (14) is fixedly connected to the first retaining ring (12). When the piezoelectric inertial actuator (14) is energized, it drives the locking pin (7) to move away from the fixed base (1), so that the locking pin (7) exits the lock hole and drives the slider (11) to push open the pawl (10) through the cable, thereby releasing the lock on the folding direction of the arm (4).

2. The folding arm device for a drone as described in claim 1, characterized in that: The arc-shaped slide rail (2) has two locking holes spaced 90 degrees apart along its arc direction. The first locking hole corresponds to the horizontal unfolded state of the machine arm (4) and the second locking hole corresponds to the vertical folded state of the machine arm (4). The two locking holes are connected by a shallow groove (5) with a depth less than the depth of the locking hole. The end of the locking pin (7) near the fixed base (1) slides along the shallow groove (5) during the rotation of the machine arm (4).

3. The folding arm device for a drone as described in claim 1, characterized in that: The ratchet disc (9) is coaxially disposed around the end of the rotating shaft that passes through the side wall of the fixed seat (1). The teeth of the ratchet disc (9) are configured to allow the ear seat (3) to rotate in the unfolding direction of the arm (4) and prevent the ear seat (3) from rotating in the folding direction of the arm (4). The pawl (10) is mounted on the outer side wall of the arm (4) near the fixed seat (1) at the root. The pawl (10) is provided with a spring that presses its end against the teeth of the ratchet disc (9). The slider (11) is slidably mounted on the guide rail on the outer side wall of the same arm (4). The slider (11) is fixedly connected to the pawl (10). When the slider (11) slides away from the fixed seat (1), the slider (11) drives the pawl (10) to disengage from the ratchet disc (9).

4. The folding arm device for a drone as described in claim 1, characterized in that: A transverse partition (15) is fixedly installed at one end of the arm (4) near the fixed seat (1). The transverse partition (15) divides the inner cavity of the arm (4) into a front cavity near the fixed seat (1) and a rear cavity away from the fixed seat (1). The locking pin (7) passes through the transverse partition (15) and extends into the front cavity at one end near the fixed seat (1). A second retaining ring (13) is fixedly installed on the locking pin (7) in the front cavity. The locking spring (8) is sleeved on the locking pin (7) and located between the transverse partition (15) and the second retaining ring (13). The locking spring (8) is a compression spring. When the locking pin (7) moves away from the fixed seat (1), the second retaining ring (13) compresses the locking spring (8).

5. The folding arm device for a drone as described in claim 1, characterized in that: A push switch (16) is embedded on the lower side of the outer wall of the root of the arm (4). A connecting rod (17) is connected to the inner side of the push switch (16). One end of the connecting rod (17) is fixedly connected to the push switch (16), and the other end is fixedly connected to the second retaining ring (13). When the push switch (16) is pressed, the end of the connecting rod (17) directly pushes the second retaining ring (13), which further drives the locking pin (7) to move away from the fixed seat (1), so that the end of the locking pin (7) disengages from the lock hole.

6. The arm folding device for a drone as described in claim 1, characterized in that: The piezoelectric inertial actuator (14) is fixedly installed at the bottom of the rear cavity of the arm (4), and its output shaft is coaxially fixedly connected to the end of the locking pin (7) away from the fixed seat (1). After receiving the pulse signal from the flight control system, the piezoelectric inertial actuator (14) moves stepwise and maintains its current position by relying on internal static friction after power failure.

7. The folding arm device for a drone as described in claim 1, characterized in that: One end of the cable is fixedly connected to the second retaining ring (13), and the other end of the cable is fixedly connected to the slider (11).

8. The folding arm device for a drone as described in claim 1, characterized in that: The outer side wall of the arm (4) is provided with a streamlined protective cover (6) for covering the pawl (10) and the slider (11).

Images