UAV propeller balance test device and method

Abstract

The present invention discloses a device and method for testing the balance of a propeller of a drone, and relates to the technical field of balance testing. The propeller comprises two blades and a connecting member, the connecting member comprises a horizontal plate and two U-shaped plates, the inner end of the blade is provided with a circular plate, the circular plate is fixedly arranged in the U-shaped plate, and the horizontal plate is provided with a circular hole; the device comprises: a supporting mechanism comprises a first lifting assembly, a base and horizontal plates arranged on both sides of the base, the first lifting assembly is used to control the height of the base, the top surface of the base is arranged as an arc surface, and is used to place the propeller; a limiting mechanism comprises a second lifting assembly and a pressing block, the second lifting assembly is arranged above the base through a bracket, the second lifting assembly is used to control the height of the pressing block, and is used to fix the propeller when the pressing block moves downward; a spike adjustment mechanism is used to insert the spike into the circular hole; each photoelectric sensor comprises a transmitter and a receiver, which are respectively arranged on two supporting plates, and are used to detect whether the propeller is unbalanced. This scheme can automatically insert the spike into the circular hole, thereby improving the detection efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of balance testing, and in particular to a device and method for testing the balance of a propeller of an unmanned aerial vehicle. Background Art

[0002] The processing flow of drone propellers is as follows: first, use a mold to form at high temperature and high pressure to obtain the blades; after the blades are polished, assemble the two blades onto the connector to obtain the propeller; test the propeller's balancing performance, and finally paint the propeller with qualified balancing performance.

[0003] The propeller balance test of a drone is a very important step. If the propeller balance performance is not up to standard, many problems will arise: ① Unbalanced propellers will cause greater stress and load, accelerate the wear of the propeller itself and related components, and shorten the service life; ② Unbalanced propellers will produce vibrations and asymmetric airflow, thereby affecting the flight stability of the drone and even causing the drone to lose control and crash.

[0004] When the staff tests the propeller's balance performance, the steps are as follows: first insert a long nail into the round hole of the connector, then hold the propeller with your hand and support the two ends of the long nail on the bracket; release the propeller and observe whether the propeller can maintain balance. There are problems with the above process: ① The long nail needs to be inserted into the round hole manually, and after the test, the long nail needs to be removed manually; ② When the propeller is released by hand, if the propeller is tilted at the beginning, the propeller needs to swing for several seconds or minutes before gradually reaching a balanced state, which causes the test process to take a long time and be inefficient, and may also cause the staff to judge the propeller imbalance too early, resulting in inaccurate judgment results; ③ The method of judging whether the propeller is balanced by the naked eye has certain errors. When the swing amplitude of the propeller is very small, it may not be observed by the naked eye. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a UAV propeller balance test device and method, which can automatically insert a long nail into the circular hole of the propeller to improve the detection efficiency.

[0006] In order to achieve the purpose of the present invention, the following scheme is proposed:

[0007] A propeller balance test device for an unmanned aerial vehicle, wherein the propeller comprises two blades and a connecting piece, wherein the connecting piece comprises a transverse plate and two U-shaped plates respectively arranged at the ends thereof, a circular plate is arranged at the inner end of the blade, the circular plate is fixedly arranged in the corresponding U-shaped plate, the transverse plate is provided with a circular hole, and the device comprises a supporting mechanism, a limiting mechanism, a long spike adjustment mechanism, and a plurality of photoelectric sensors.

[0008] The support mechanism includes a first lifting assembly, a base and two horizontal plates. The first lifting assembly is arranged on the operating table and is used to control the height of the base. The top surface of the base is arranged as an arc surface. The two horizontal plates are respectively arranged on both sides of the arc surface. When the propeller is placed on the base, the two circular plates are tangent to the base, and the bottom surfaces of the two U-shaped plates are closely attached to the corresponding horizontal plates.

[0009] The limiting mechanism includes a second lifting assembly and a pressing block. The second lifting assembly is arranged above the base through a bracket. The second lifting assembly is used to control the height of the pressing block and is used to fix the propeller when the pressing block moves downward.

[0010] The spike adjustment mechanism is arranged at the outer end of the base, and includes a spike arranged parallel to the upper part of the base. The spike adjustment mechanism is used to drive the spike to move along the axis so as to connect or separate the spike from the circular hole.

[0011] Each photoelectric sensor includes a transmitter and a receiver, which are respectively arranged on two support plates. Some photoelectric sensors are used to detect whether the upper edge of the blade exceeds the preset position, and some photoelectric sensors are used to detect whether the lower edge of the blade exceeds the preset position.

[0012] Furthermore, the spike adjustment mechanism includes a motor, a main rod, two side rods and a slide seat. A U-shaped base is provided on the top of the operating table. The two side rods are fixed in the U-shaped base. The main rod is rotatably provided in the U-shaped base. The motor is used to drive the main rod. The main rod and the two side rods all slide through the slide seat. Two end-to-end connected slides are provided on the outer wall of the main rod. The first slide extends spirally from the first end of the main rod to the second end, and the second slide extends spirally from the second end of the main rod to the first end. The thread lead angle of the second slide is greater than the thread lead angle of the first slide. A rolling column is provided on the inner wall of the slide seat. The rolling column is slidably fitted in the slide. The top of the slide seat is provided on the first square plate. One end of the long nail is fixed on the first square plate, and the other end is used to insert into the round hole.

[0013] Furthermore, a second square plate is provided on the top of one side of the U-shaped base close to the base, and the long nail slides through the second square plate.

[0014] Furthermore, the bottom surface of the pressing block is configured as an arc-shaped surface, and when the pressing block moves downward, it is used to be tangent to the two circular plates.

[0015] Furthermore, the supporting mechanism also includes four clamping components, two of which form a group and are symmetrically arranged on corresponding horizontal plates. Each clamping component includes an abutment plate, a block, a vertical plate and a center rod. The abutment plate and the vertical plate are respectively arranged at both ends of the block. The horizontal plate is provided with two through grooves. The vertical plate slides horizontally in the corresponding through grooves. Three support blocks are provided in a straight line at the bottom of the horizontal plate. The center rod is provided between two adjacent support blocks. The center rod slides through the vertical plate. A spring is provided on the outer periphery of the center rod. Both ends of the spring are respectively connected to the vertical plate and the middle support block. The vertical plate is tightly attached to the outer support block. The block is provided with an inverted trapezoidal groove that runs through it from top to bottom. In the direction from the abutment plate to the vertical plate, the inner inclined surface of the inverted trapezoidal groove is inclined downward. When the inner inclined surface is squeezed, the abutment plate will be prompted to move toward the propeller and abut the propeller.

[0016] Furthermore, the limiting mechanism also includes a top plate and four columns arranged at the bottom thereof, a pressure block is arranged at the bottom of the top plate and located between the four columns, and a second lifting assembly is connected to the top plate and is used to squeeze the inner inclined surface of the inverted trapezoidal groove when the column moves downward.

[0017] A method for testing the propeller balance of a drone, using the drone propeller balance testing device, the method comprises the following steps:

[0018] S1. Place the propeller on the base, with the two circular plates tangent to the base and the bottom surfaces of the two U-shaped plates close to the corresponding horizontal plates;

[0019] S2, using the second lifting assembly to move the pressing block downward to fix the propeller;

[0020] S3, inserting the long nail into the round hole using the long nail adjustment mechanism;

[0021] S4, using the second lifting assembly to move the pressing block upward, and using the first lifting assembly to move the base downward;

[0022] S5. Use the photoelectric sensor to detect whether the propeller is in a balanced state. If it is unbalanced, the indicator light will light up.

[0023] Further, step S2: using the second lifting assembly to move the top plate downward until the pressing block is tangent to the two circular plates, and the upright column is inserted into the corresponding inverted trapezoidal groove, so that the abutting plate abuts against the circular plate.

[0024] Further, step S3: using a motor to drive the main rod, causing the rolling column to move along the first slideway, thereby causing the slide seat to move toward the base, and when the rolling column moves to the junction of the first slideway and the second slideway, it stops, and the long nail has been inserted into the round hole.

[0025] The beneficial effects of the present invention are as follows: the staff only needs to place the propeller on the base, and the propeller can be fixed on the base through the cooperation of the base, the horizontal plate and the pressure block, ensuring that the long nail is facing the circular hole of the propeller, so that the long nail can be automatically inserted into the circular hole by using the long nail adjustment mechanism; after the base, the horizontal plate and the pressure block are separated from the propeller, the propeller is in a suspended state, so that the balance performance of the propeller can be tested by using the photoelectric sensor. In summary, this scheme does not require manual insertion of the long nail into the circular hole or removal of the long nail, and the initial state of each propeller when it is just suspended is unified. The photoelectric sensor is also used to detect whether the propeller is unbalanced. This scheme improves the detection efficiency and detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of one side of a propeller is shown;

[0027] Figure 2 A schematic diagram of the other side of the propeller is shown;

[0028] Figure 3 shows a structural diagram of a balance test device;

[0029] Figure 4 shows a right side view of the balance test device;

[0030] Figure 5 A front view of a balance test device is shown;

[0031] Figure 6 A top view of the spike adjustment mechanism is shown;

[0032] Figure 7 A front view of a balance test apparatus having a clamping assembly is shown;

[0033] Figure 8 Shows Figure 7 A partial enlarged view of the middle part;

[0034] Fig. 9 A diagram showing the structure of the clamping assembly and the base is shown;

[0035] Fig.10 A flow chart of the balance test method is shown;

[0036] Reference numerals: support mechanism-1, first lifting assembly-11, base-12, horizontal plate-13, through slot-131, support block-132, clamping assembly-14, abutment plate-141, block-142, inverted trapezoidal slot-1421, vertical plate-143, center rod-144, limit mechanism-2, second lifting assembly-21, bracket-211, pressure block-22, top plate-23, column-24, long nail adjustment machine Structure-3, spike-31, main rod-32, first slide-321, second slide-322, motor-33, slide seat-34, first square plate-341, side rod-35, connecting piece-41, cross plate-411, U-shaped plate-412, round hole-413, paddle-42, round plate-421, transmitter-51, receiver-52, support plate-53, operating table-6, U-shaped base-61, second square plate-62. DETAILED DESCRIPTION

[0037] Example 1

[0038] like Figure 1 , Figure 2 As shown, the propeller includes two blades 42 and a connecting member 41. The connecting member 41 includes a transverse plate 411 and two U-shaped plates 412. The two U-shaped plates 412 are respectively arranged at the ends of the transverse plate 411. The U-shaped groove opening of the U-shaped plate 412 is perpendicular to the long axis direction of the transverse plate 411. A circular plate 421 is provided at the inner end of the blade 42. The circular plate 421 is fixed in the corresponding U-shaped plate 412. The transverse plate 411 is provided with a circular hole 413.

[0039] like Figure 3 As shown, this embodiment provides a UAV propeller balance test device, and for detecting the balance performance of the above-mentioned propeller, the device includes a support mechanism 1, a limit mechanism 2, a spike adjustment mechanism 3, and multiple photoelectric sensors.

[0040] Specifically, Figure 3 , Figure 4 As shown, the support mechanism 1 includes a first lifting component 11, a base 12 and two horizontal plates 13. The top surface of the base 12 is set as an arc surface, and the two horizontal plates 13 are symmetrically arranged on both sides of the arc surface. The first lifting component 11 is arranged on the operating table 6. The top of the first lifting component 11 is connected to the base 12 for controlling the height of the base 12. The power source of the first lifting component 11 can be driven by a cylinder, an oil cylinder or a hydraulic cylinder. When the propeller is placed on the base 12, the two circular plates 421 are tangent to the base 12, and the bottom surfaces of the two U-shaped plates 412 are close to the corresponding horizontal plates 13.

[0041] Specifically, the limiting mechanism 2 includes a second lifting assembly 21 and a pressure block 22. The second lifting assembly 21 is arranged above the base 12 through a bracket 211. The power source of the second lifting assembly 21 can be driven by a cylinder, an oil cylinder or a hydraulic cylinder. The second lifting assembly 21 is used to control the height of the pressure block 22. When the pressure block 22 moves down, it is used to fix the propeller. More precisely, when the pressure block 22 moves down, it is used to press the connecting piece 41 or the two circular plates 421 so that the long nail 31 can be smoothly inserted into the circular hole 413 of the propeller in the next step. Preferably, the bottom surface of the pressure block 22 is set as an arc surface, and when the pressure block 22 moves down, it is used to be tangent to the two circular plates 421 of the propeller.

[0042] Specifically, Figure 2 , Figure 3 As shown, the spike adjustment mechanism 3 is arranged at the outer end of the base 12, including a spike 31 arranged parallel to the top of the base 12, and the spike adjustment mechanism 3 is used to drive the spike 31 to move along the axis so that the spike 31 is horizontally inserted into the circular hole 413. After the balance test is completed, the spike adjustment mechanism 3 is also used to remove the spike 31 from the circular hole 413.

[0043] Specifically, Figure 1 , Figure 3 As shown, in the present embodiment, two photoelectric sensors are provided. In practical applications, the number of photoelectric sensors can be increased as needed. Each photoelectric sensor includes a transmitter 51 and a receiver 52. The photoelectric sensor is a conventional product. The transmitter 51 transmits a signal to the receiver 52. When there is an obstruction between the two, the receiver 52 cannot smoothly receive the signal, resulting in the indicator light coming on or the alarm sounding. Two support plates 53 are provided on one side of the operating table 6. The transmitter 51 and the receiver 52 are respectively provided on the two support plates 53. One of the blades 42 of the propeller is located between the two support plates 53. The photoelectric sensor at a high position is used to detect whether the upper edge of the blade 42 exceeds the preset position. The photoelectric sensor at a low position is used to detect whether the lower edge of the blade 42 exceeds the preset position. When both the upper edge and the lower edge of the blade 42 do not exceed the preset position, it indicates that the propeller is in a balanced state. If the upper edge or the lower edge of the blade 42 exceeds the preset position, the signal transmission between the transmitter 51 and the receiver 52 will be blocked, resulting in the indicator light coming on or the alarm sounding, reminding the staff that the propeller is unbalanced and the balancing performance is unqualified.

[0044] The specific implementation of the spike adjustment mechanism 3 is as follows: Figure 3 , Figure 5 , Figure 6As shown, it includes a motor 33, a main rod 32, two side rods 35 and a slide 34. A U-shaped base 61 is provided on the top of the operating table 6. The two side rods 35 are fixedly arranged in the U-shaped base 61. The main rod 32 is rotatably arranged in the U-shaped base 61, and the main rod 32 is parallelly located between the two side rods 35. The motor 33 is arranged outside the U-shaped base 61, and its output shaft is used to drive the main rod 32. The main rod 32 and the two side rods 35 are all slidably passed through the slide 34. The outer wall of the main rod 32 is provided with a slideway connected end to end. They are respectively a first slide 321 and a second slide 322. The first slide 321 spirally extends from the first end of the main rod 32 to the second end of the main rod 32, and the second slide 322 spirally extends from the second end of the main rod 32 to the first end of the main rod 32. The thread lead angle of the second slide 322 is greater than the thread lead angle of the first slide 321. A rolling column is provided on the inner wall of the slide seat 34, and the rolling column is slidably fitted in the slide. The top of the slide seat 34 is provided on the first square plate 341, and one end of the long nail 31 is fixedly provided on the first square plate 341.

[0045] When in use, the propeller is first fixed to the base 12 through the cooperation of the supporting mechanism 1 and the limiting mechanism 2. At this time, the long spike 31 is facing the circular hole 413 of the propeller; then the main rod 32 is driven by the motor 33, which will cause the rolling column to move along the first slide 321. Because the slide seat 34 is limited by the two side rods 35, the slide seat 34 can only move horizontally toward the base 12. When the rolling column moves to the junction of the first slide 321 and the second slide 322, it stops. At this time, the long spike 31 has been inserted into the circular hole 413; the second lifting assembly 21 is used to The pressure block 22 is moved upward, and the base 12 is moved downward by the first lifting assembly 11. The propeller is suspended after losing the restrictions of the pressure block 22 and the base 12, so that a balance test can be performed using a photoelectric sensor. After the test, the staff holds the propeller, and the motor 33 drives the main rod 32 to cause the rolling column to move along the second slide 322, thereby causing the slide 34 to move horizontally away from the base 12. The rolling column stops when it moves to the junction of the second slide 322 and the first slide 321, and the long nail 31 is completely out of the round hole 413.

[0046] Here are a few points:

[0047] First point: the thread lead angle of the second slide 322 is greater than the thread lead angle of the first slide 321. Within the same length range, the larger the thread lead angle, the fewer the number of spiral turns. In actual applications, the number of spiral turns of the first slide 321 can be set to 0.75 turns, and the number of spiral turns of the second slide 322 can be set to 0.25 turns. The purpose of this design is: the long nail 31 can be slowly inserted into the round hole 413, and when it is out of the round hole 413, the long nail 31 can quickly get out of the round hole 413.

[0048] The second point: the top surface of the base 12 is set to an arcuate surface, and two horizontal plates 13 are symmetrically arranged on both sides of the base 12. The purpose of this design is: when the staff places the propeller on the base 12, the arcuate surface of the base 12 and the horizontal plate 13 play a role in fine-tuning the position of the propeller, so that the circular hole 413 of the propeller can quickly and accurately face the long spike 31. Imagine that if the top surface of the base 12 is a plane, or there are no horizontal plates 13 on both sides of the base 12, when the staff places the propeller on the base 12, it is impossible to quickly and accurately make the circular hole 413 of the propeller face the long spike 31.

[0049] The third point: the bottom surface of the pressing block 22 is set as an arc surface, which is used to be tangent to the two circular plates 421 of the propeller. The purpose of this design is: as mentioned in the second point, the arc surface of the base 12 and the horizontal plate 13 play a role in fine-tuning the position of the propeller, so the bottom surface of the pressing block 22 is set as an arc surface. When the bottom surface of the pressing block 22 is tangent to the two circular plates 421, it can not only fix the propeller, but also further fine-tune the position of the propeller.

[0050] Fourth point: In order to improve the stability of the spike 31, Figure 3 As shown, in this embodiment, a second square plate 62 is provided on the top of one side of the U-shaped base 61 close to the base 12 , and the long nail 31 slides through the second square plate 62 .

[0051] More specifically, in the above scheme, the propeller is fixed to the base 12 by the cooperation of the support mechanism 1 and the limit mechanism 2, which belongs to the fixation of the propeller in the vertical direction. In order to further improve the stability of the propeller and ensure that the long nail 31 is smoothly inserted into the round hole 413, this embodiment takes the following measures:

[0052] like Figure 3 , Figure 7-Figure 9As shown, the support mechanism 1 also includes four clamping assemblies 14 for fixing the propeller in the horizontal direction. Two clamping assemblies 14 form a group and are symmetrically arranged on the corresponding horizontal plate 13. Each clamping assembly 14 includes an abutment plate 141, a block 142, a vertical plate 143 and a center rod 144. The abutment plate 141 and the vertical plate 143 are respectively arranged at both ends of the block 142, and the abutment plate 141 faces the direction of the propeller. The horizontal plate 13 is provided with two through grooves 131. The vertical plate 143 horizontally slides in the corresponding through grooves 131. The bottom of the vertical plate 143 extends to the bottom of the horizontal plate 13. Three support blocks 132 are arranged along a straight line at the bottom of the horizontal plate 13. The center rod 144 is arranged between two adjacent support blocks 132. The center rod 144 slides The vertical plate 143 is movable through the vertical plate 143, and a spring is provided on the outer periphery of the central rod 144. The two ends of the spring are respectively connected to the vertical plate 143 and the middle support block 132. The vertical plate 143 is close to the outer support block 132. The block 142 is provided with an inverted trapezoidal groove 1421 which runs through itself from top to bottom. In the direction from the abutment plate 141 to the vertical plate 143, the inner inclined surface of the inverted trapezoidal groove 1421 is inclined downward. When the inner inclined surface is squeezed, the abutment plate 141 is prompted to move toward the propeller and abut the propeller. More precisely, among the four clamping assemblies 14, two abutment plates 141 abut the connecting piece 41, and the other two abutment plates 141 respectively abut the two circular plates 421. It is not recommended that the abutment plate 141 abuts the blade 42 to prevent the blade 42 from deformation.

[0053] The limiting mechanism 2 also includes a top plate 23 and four columns 24 arranged at the bottom thereof. The pressure block 22 is arranged at the bottom of the top plate 23, and the pressure block 22 is located between the four columns 24. The second lifting assembly 21 is connected to the top plate 23. Each column 24 corresponds to a block 142. When the column 24 moves downward, it is used to squeeze the inner inclined surface of the inverted trapezoidal groove 1421.

[0054] Here are a few points:

[0055] First point: the center rod 144 is arranged below the horizontal plate 13 in order to save space.

[0056] Second point: Figure 8 From the perspective, the vertical plate 143 is close to the outer support block 132. The purpose of this design is that the column 24 is facing the specific position of the inclined surface inside the inverted trapezoidal groove 1421, ensuring that when the column 24 moves downward, it can be smoothly inserted into the inverted trapezoidal groove 1421.

[0057] The third point: the four columns 24 and the pressure block 22 share a power source. When the second lifting assembly 21 moves the top plate 23 downward, the four columns 24 and the pressure block 22 can be moved downward at the same time. When the pressure block 22 is tangent to the two circular plates 421, the column 24 can be inserted into the corresponding inverted trapezoidal groove 1421, prompting the abutment plate 141 to abut the propeller. The structure is ingenious and saves additional power source.

[0058] Example 2

[0059] like Fig.10 As shown, this embodiment provides a method for testing the propeller balance of a UAV, using the UAV propeller balance testing device described in Example 1, and the method includes the following steps:

[0060] S1. The staff places the propeller on the base 12. The two circular plates 421 of the propeller are tangent to the base 12. The bottom surfaces of the two U-shaped plates 412 are in close contact with the corresponding horizontal plates 13. At this time, the propeller is located between the four clamping components 14.

[0061] S2, using the second lifting assembly 21 to move the top plate 23 downward until the pressing block 22 is tangent to the two circular plates 421, and the column 24 is inserted into the corresponding inverted trapezoidal groove 1421, so that the abutment plate 141 abuts against the propeller;

[0062] S3, using the motor 33 to drive the main rod 32, so that the rolling column moves along the first slideway 321, and then the slide seat 34 moves toward the base 12, and the rolling column stops when it moves to the junction of the first slideway 321 and the second slideway 322, at which time the long nail 31 has been inserted into the round hole 413;

[0063] S4, the top plate 23 is moved upward by the second lifting assembly 21, the pressing block 22 is separated from the propeller, and after the four columns 24 are separated from the inverted trapezoidal grooves 1421, the abutment plate 141 is separated from the propeller under the action of the spring, and the base 12 is moved downward by the first lifting assembly 11, at which time the propeller is in a suspended state;

[0064] S5. Use the photoelectric sensor to detect whether the propeller is in a balanced state. If it is unbalanced, the indicator light will light up;

[0065] S6. After the balancing test is completed, the staff holds the propeller, and the motor 33 drives the main rod 32 to prompt the rolling column to move along the second slide 322, thereby causing the slide seat 34 to move horizontally away from the base 12. When the rolling column moves to the junction of the second slide 322 and the first slide 321, it stops. At this time, the long nail 31 is completely out of the round hole 413; finally, the first lifting assembly 11 is used to move the base 12 up to its original position to prepare for testing the next propeller.

[0066] The above embodiments are only used to illustrate the technical ideas and features of the present invention, and are not intended to be the only or limit the present invention. It should be understood by those skilled in the art that various changes or equivalent substitutions made to the present invention without departing from the scope of the present invention all fall within the scope of protection of the present invention.

Claims

1. A propeller balancing test device for an unmanned aerial vehicle, the propeller comprising two blades (42) and a connecting member (41), the connecting member (41) comprising a transverse plate (411) and two U-shaped plates (412) respectively arranged at the ends thereof, a circular plate (421) being arranged at the inner end of the blade (42), the circular plate (421) being fixedly arranged in the corresponding U-shaped plate (412), the transverse plate (411) being provided with a circular hole (413), characterized in that: The device comprises a supporting mechanism (1), a limiting mechanism (2), a spike adjusting mechanism (3), and a plurality of photoelectric sensors; The support mechanism (1) comprises a first lifting component (11), a base (12) and two horizontal plates (13); the first lifting component (11) is arranged on the operating table (6) and is used to control the height of the base (12); the top surface of the base (12) is arranged as an arc-shaped surface; the two horizontal plates (13) are respectively located on both sides of the arc-shaped surface; when the propeller is placed on the base (12), the two circular plates (421) are tangent to the base (12), and the bottom surfaces of the two U-shaped plates (412) are closely attached to the corresponding horizontal plates (13); The limiting mechanism (2) comprises a second lifting assembly (21) and a pressing block (22); the second lifting assembly (21) is disposed above the base (12) via a bracket (211); the second lifting assembly (21) is used to control the height of the pressing block (22); and the pressing block (22) is used to fix the propeller when it moves downward; The spike adjustment mechanism (3) is disposed at the outer end of the base (12), and comprises a spike (31) disposed parallel to the upper side of the base (12). The spike adjustment mechanism (3) is used to drive the spike (31) to move along the axis so as to connect or separate the spike (31) from the circular hole (413). Each photoelectric sensor comprises a transmitter (51) and a receiver (52), which are respectively arranged on two support plates (53); a plurality of photoelectric sensors are used to detect whether the upper edge of the blade (42) exceeds a preset position; and a plurality of photoelectric sensors are used to detect whether the lower edge of the blade (42) exceeds a preset position.

2. The UAV propeller balance test device according to claim 1, characterized in that: The spike adjustment mechanism (3) comprises a motor (33), a main rod (32), two side rods (35) and a slide seat (34). A U-shaped base (61) is provided on the top of the operating table (6). The two side rods (35) are fixedly arranged in the U-shaped base (61). The main rod (32) is rotatably arranged in the U-shaped base (61). The motor (33) is used to drive the main rod (32). The main rod (32) and the two side rods (35) are all slidably passed through the slide seat (34). The outer wall of the main rod (32) is provided with two slideways connected end to end. The first slideway is provided with a first slideway. The slideway (321) spirally extends from the first end of the main rod (32) to the second end, the second slideway (322) spirally extends from the second end of the main rod (32) to the first end, the thread lead angle of the second slideway (322) is greater than the thread lead angle of the first slideway (321), a rolling column is provided on the inner wall of the slide seat (34), the rolling column is slidably matched in the slideway, the top of the slide seat (34) is provided on the first square plate (341), one end of the long nail (31) is fixedly provided on the first square plate (341), and the other end is used to be inserted into the round hole (413).

3. The UAV propeller balance test device according to claim 2, characterized in that: A second square plate (62) is provided on the top of one side of the U-shaped base (61) close to the base (12), and the long nail (31) slides through the second square plate (62).

4. The UAV propeller balance test device according to claim 2, characterized in that: The bottom surface of the pressing block (22) is configured as an arc-shaped surface, and when the pressing block (22) moves downward, it is used to be tangent to the two circular plates (421).

5. The UAV propeller balance test device according to claim 4, characterized in that: The support mechanism (1) further comprises four clamping assemblies (14), two clamping assemblies (14) forming a group, which are symmetrically arranged on the corresponding horizontal plate (13), each clamping assembly (14) comprising an abutting plate (141), a block (142), a vertical plate (143) and a central rod (144), the abutting plate (141) and the vertical plate (143) being respectively arranged at two ends of the block (142), the horizontal plate (13) being provided with two through grooves (131), the vertical plate (143) being horizontally slidably matched with the corresponding through grooves (131), three support blocks (132) being arranged along a straight line at the bottom of the horizontal plate (13), and the central rod (144) being arranged at Between two adjacent support blocks (132), a central rod (144) slides through the vertical plate (143), a spring is provided on the outer periphery of the central rod (144), two ends of the spring are respectively connected to the vertical plate (143) and the middle support block (132), the vertical plate (143) is closely attached to the outer support block (132), the block (142) is provided with an inverted trapezoidal groove (1421) which penetrates the block (142) from top to bottom, and an inner inclined surface of the inverted trapezoidal groove (1421) is inclined downward in the direction from the abutment plate (141) to the vertical plate (143), and when the inner inclined surface is squeezed, the abutment plate (141) is urged to move toward the propeller direction and abut the propeller.

6. The UAV propeller balance test device according to claim 5, characterized in that: The limiting mechanism (2) further comprises a top plate (23) and four upright posts (24) arranged at the bottom thereof. The pressing block (22) is arranged at the bottom of the top plate (23) and is located between the four upright posts (24). The second lifting assembly (21) is connected to the top plate (23) and is used to press the inner inclined surface of the inverted trapezoidal groove (1421) when the upright posts (24) move downward.

7. A method for testing the balance of a propeller of an unmanned aerial vehicle, characterized in that: Using the drone propeller balance test device as claimed in claim 6, the method comprises the following steps: S1. Place the propeller on the base (12), with the two circular plates (421) being tangent to the base (12), and the bottom surfaces of the two U-shaped plates (412) being in close contact with the corresponding horizontal plates (13); S2, using the second lifting assembly (21) to move the pressing block (22) downward to fix the propeller; S3, using the spike adjustment mechanism (3) to insert the spike (31) into the circular hole (413); S4, using the second lifting assembly (21) to move the pressing block (22) upward, and using the first lifting assembly (11) to move the base (12) downward; S5. Use the photoelectric sensor to detect whether the propeller is in a balanced state. If it is unbalanced, the indicator light will light up.

8. The method for testing the balance of a propeller of a UAV according to claim 7, characterized in that: Step S2: using the second lifting assembly (21) to move the top plate (23) downward until the pressing block (22) is tangent to the two circular plates (421), and the column (24) is inserted into the corresponding inverted trapezoidal groove (1421), so that the abutment plate (141) abuts against the propeller.

9. The method for testing the propeller balance of a UAV according to claim 7, characterized in that: Step S3: Using the motor (33) to drive the main rod (32), the rolling column is moved along the first slideway (321), thereby causing the slide seat (34) to move toward the base (12). When the rolling column moves to the junction of the first slideway (321) and the second slideway (322), it stops. At this time, the long nail (31) has been inserted into the round hole (413).

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