An aviation unmanned aerial vehicle crankshaft strength test electro-hydraulic loading system and a control method thereof

Abstract

The application discloses an aviation unmanned aerial vehicle (UAV) crankshaft strength test electro-hydraulic loading system. The system comprises a shell, a base for fixing the crankshaft is arranged at the bottom of the shell, a radial hydraulic cylinder group is arranged on the upper side wall of the shell, the radial hydraulic cylinder group is arranged in the radial direction of the crankshaft, the radial hydraulic cylinder group is matched with the connecting rod neck of the crankshaft, an axial hydraulic cylinder group is arranged on the left side wall of the shell, the axial hydraulic cylinder group is arranged in the axial direction of the crankshaft, the axial hydraulic cylinder group is matched with the front end output shaft of the crankshaft, the aviation UAV crankshaft strength test electro-hydraulic loading system further comprises a rotary encoder, and the rotary encoder is connected with the front end output shaft of the crankshaft. The electro-hydraulic loading system of the aviation UAV crankshaft strength can simultaneously simulate the axial force and the radial force encountered by the crankshaft in the aviation UAV engine. In addition, the system can be used for detecting the overall torsional bending strength of a new lightweight crankshaft, and the force loading of different parts can be carried out, so that the reliability of the aviation UAV crankshaft can be fully verified.

Description

Technical Field

[0001] This invention relates to a crankshaft strength testing tool, and more specifically, to an electro-hydraulic loading system for testing the crankshaft strength of an aircraft or unmanned aerial vehicle (UAV). Background Technology

[0002] In the field of unmanned aerial vehicles (UAVs), piston engines offer advantages over other engines, including better stability, higher mechanical efficiency, smaller size, and lighter weight, making them widely used in low-speed, low-altitude UAVs. The crankshaft is the most complex component in the manufacturing of UAV engines. Unlike common small engine crankshafts, UAV crankshafts typically employ more extreme lightweight designs, reducing weight through complex deep-hole drilling processes while maintaining sufficient torsional strength. Furthermore, compared to motorcycle crankshafts, their output end sometimes directly connects to a propeller, generating additional axial tension. Invention patent (CN202010765895.3) primarily focuses on crankshaft loading tests on the engine belt side; invention patent (CN201510229337.4) provides a test device for the engine test front-end output to simulate crankshaft front-end output. Existing authorized invention patents lack testing devices for the operating conditions of small UAV crankshafts.

[0003] In summary, an electro-hydraulic loading system and control method for testing the strength of crankshafts in aviation unmanned aerial vehicles (UAVs) were designed to meet the aviation industry's requirements for lightweight and high-strength crankshafts and ensure reliable crankshaft design. Summary of the Invention

[0004] Therefore, it is necessary to provide an electro-hydraulic loading system for testing the crankshaft strength of unmanned aerial vehicles (UAVs) in response to the above-mentioned technical problems.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: An electro-hydraulic loading system for testing the crankshaft strength of an unmanned aerial vehicle (UAV) is characterized in that the system includes a housing, and the bottom of the housing is provided with a base for fixing the crankshaft. A radial hydraulic cylinder assembly is provided on the upper side wall of the housing. The radial hydraulic cylinder assembly is arranged radially on the crankshaft and cooperates with the connecting rod journal of the crankshaft. An axial hydraulic cylinder assembly is provided on the left side wall of the housing. The axial hydraulic cylinder assembly is positioned along the axial direction of the crankshaft and cooperates with the front output shaft of the crankshaft. The electro-hydraulic loading system for testing the crankshaft strength of the unmanned aerial vehicle (UAV) also includes a rotary encoder, which is connected to the front output shaft of the crankshaft.

[0006] In a preferred embodiment of the present invention, the main journal of the crankshaft is fixed to the base by bolts.

[0007] As a preferred embodiment of the present invention, The radial hydraulic cylinder assembly comprises several radially arranged radial hydraulic units. Each radial hydraulic unit includes a radial hydraulic cylinder, a radial piston rod, and a hinge joint. The hinge joint is connected to the connecting rod journal of the crankshaft via a connecting rod. The axial hydraulic cylinder assembly includes several axially arranged axial hydraulic units. Each axial hydraulic unit includes an axial hydraulic cylinder and an axial piston rod. The head of the axial piston rod is provided with a disc-shaped moving platform. A hydraulic motor is provided on the moving platform. The hydraulic motor is connected to the front output shaft of the crankshaft.

[0008] As a preferred embodiment of the present invention, The radial hydraulic cylinder is connected to the control center via a first servo valve, the axial hydraulic cylinder is connected to the control center via a second servo valve, and the hydraulic motor is connected to the control center via a third servo valve.

[0009] A control method for an electro-hydraulic loading system for testing the crankshaft strength of an unmanned aerial vehicle (UAV) as described above, characterized in that the control method is used for test conditions S1, S2, and S3. in, When performing test condition S1, the desired reciprocating motion signal of the radial piston rod is set to... , Where f is the frequency of the reciprocating motion; the resistance torque of the hydraulic motor is set as: Set the tensile force of the moving platform to: ;in, Both are the rated torsional torque and rated tensile force specified in the design requirements; then, the recording angle α of the hydraulic motor's rotation and the feedback angle from the encoder are recorded. β The difference is calculated, and the overall stiffness of the crankshaft of the new type of aviation UAV is judged based on the error to determine whether it meets the design requirements. When performing test condition S2, the desired signal of the axial piston rod is set to a constant value, thereby holding the crankshaft in a fixed position through electro-hydraulic drive force to prevent rotation, and the driving torque of the hydraulic motor (13) is set to... Set the tensile force of the moving platform to: ;in, The crankshaft is designed to withstand the required limiting torsional torque and tensile force. The recorded angle α from the hydraulic motor rotation and the feedback angle from the encoder are then used. βThe difference is calculated, and the error is used to determine whether the ultimate torsional strength of the crankshaft of the new type of aviation UAV meets the design requirements. When performing test condition S3, the desired angle of the hydraulic motor is set to 0 degrees, thereby holding the crankshaft in a fixed position through electro-hydraulic drive force to prevent rotation, and setting the drive force of the axial piston rod (16). , To determine the ultimate tensile force specified in the crankshaft design, the moving platform deflects the crankshaft's axial tensile force at a certain angle, and the deflection angle is recorded. To simulate a crankshaft under unbalanced load, the displacement of the radial piston rod was then recorded. The change in displacement is used to determine whether the crankshaft's bending limit meets the design requirements. Compared with the prior art, the present invention has the following beneficial effects: This invention provides an electro-hydraulic loading system for testing the strength of crankshafts in unmanned aerial vehicles (UAVs). This electro-hydraulic loading device can simultaneously simulate the axial and radial forces encountered by the crankshaft in an UAV engine. Furthermore, it can be used to test the overall torsional bending strength of novel lightweight crankshafts and can apply force to different parts, fully verifying the reliability of the UAV crankshaft. Attached Figure Description

[0010] To more clearly illustrate the solutions in this invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the components of the crankshaft; Figure 2 This is a schematic diagram of the electro-hydraulic loading system for testing the crankshaft strength of an unmanned aerial vehicle (UAV) according to the present invention; Figure 3 This is a control schematic diagram of the electro-hydraulic loading system for testing the crankshaft strength of an unmanned aerial vehicle (UAV) according to the present invention; Figure 4 This is a schematic diagram of crankshaft mechanical analysis under various operating conditions. Detailed Implementation

[0012] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0013] like Figures 1 to 3As shown, the electro-hydraulic loading system for testing the crankshaft strength of an aviation UAV includes a housing 100, and the bottom of the housing 100 is provided with a base 14 for fixing the crankshaft 1.

[0014] A radial hydraulic cylinder assembly P1 is provided on the upper side wall of the housing 100. The radial hydraulic cylinder assembly P1 is arranged in the radial direction of the crankshaft 1 and cooperates with the connecting rod journal of the crankshaft 1. An axial hydraulic cylinder assembly P2 is provided on the left side wall of the housing 100. The axial hydraulic cylinder assembly P2 is positioned along the axial direction of the crankshaft 1 and cooperates with the front output shaft 5 of the crankshaft 1. The electro-hydraulic loading system for testing the crankshaft strength of the unmanned aerial vehicle also includes a rotary encoder 6, which is connected to the front output shaft 4 of the crankshaft 1.

[0015] It should be noted that the main journal 2 of the crankshaft 1 is fixed to the base 14 by bolts.

[0016] The radial hydraulic cylinder assembly P1 includes several radially arranged radial hydraulic units, each of which includes a radial hydraulic cylinder 10, a radial piston rod 9, and a hinge joint 8. The hinge joint 8 is connected to the connecting rod neck 3 of the crankshaft 1 via a connecting rod 7.

[0017] It should be noted that the radial hydraulic cylinder 10 is fixed on the upper side wall of the housing 100 and is staggered based on the spacing of the connecting rod neck 3 to ensure that the output force of the radial electro-hydraulic loading device can be transmitted radially to the crankshaft 1.

[0018] The axial hydraulic cylinder assembly P2 includes several axially arranged axial hydraulic units. Each axial hydraulic unit includes an axial hydraulic cylinder 11 and an axial piston rod 16. The head of the axial piston rod 16 is provided with a disc-shaped moving platform 12. A hydraulic motor 13 is provided on the moving platform 12. The hydraulic motor 13 is connected to the front output shaft 5 of the crankshaft 1.

[0019] It should be noted that the front output shaft 5 of crankshaft 1 is the main power output end and is connected to the hydraulic motor 13. The hydraulic motor 13 can provide both resistance and loading force for the crankshaft 1 during the test conditions. The front output end 4 of crankshaft 1 is mainly connected to the high-precision rotary encoder 6 to record the deformation of the crankshaft during the torsional strength test. In addition, the hydraulic motor 13 is fixedly installed at the center of the moving platform 12 of the axial electro-hydraulic loading device 11. Under the action of the axial hydraulic cylinder 11, it can generate a tensile force with different deflection angles on the axial direction of crankshaft 1.

[0020] like Figure 3As shown, the radial hydraulic cylinder 10 is connected to the control center 19 via the first servo valve 15, the axial hydraulic cylinder 11 is connected to the control center 19 via the second servo valve 17, and the hydraulic motor 13 is connected to the control center 19 via the third servo valve 18.

[0021] The control center 19 controls different crankshaft test conditions by controlling the first servo valve 15, the second servo valve 17, and the third servo valve 18. For example, test condition S1 is mainly to obtain the stress and deformation of the crankshaft during normal torsion; test condition S2 is mainly to obtain the torsional strength limit of the crankshaft; and test condition S3 is mainly to obtain the bending strength limit of the crankshaft.

[0022] Combination Figure 4 The stress analysis diagram of the crankshaft is shown, and the electro-hydraulic control methods for various test conditions are as follows: When testing condition S1: the desired reciprocating motion signal of the radial piston rod 9 is set to... , Where f is the frequency of the reciprocating motion; the resistance torque of the hydraulic motor 13 is set as follows: Set the tensile force of the moving platform 12 to: ;in, Both are the rated torsional torque and rated tensile force specified in the design requirements; then, the recording angle α of the rotation of the hydraulic motor 13 and the feedback angle fed back by the encoder are recorded. β The difference is calculated, and the overall stiffness of the crankshaft of the new type of aviation UAV is judged based on the error to determine whether it meets the design requirements. During test condition S2: the desired signal of the axial piston rod 16 is set to a constant value, thereby holding the crankshaft in a fixed position through electro-hydraulic drive force to prevent rotation; the driving torque of the hydraulic motor 13 is set to... Set the tensile force of the moving platform 12 to: ;in, To determine the limiting torsional torque and tensile force required during crankshaft design, the recording angle α of the hydraulic motor 13 rotation and the feedback angle from the encoder are then used. β The difference is calculated, and the error is used to determine whether the ultimate torsional strength of the crankshaft of the new type of aviation UAV meets the design requirements. When testing condition S3: the desired angle of hydraulic motor 13 is set to 0 degrees, thereby holding the crankshaft in a fixed position through electro-hydraulic drive force to prevent rotation, and the driving force of axial piston rod 16 is set. , To determine the ultimate tensile force specified in the crankshaft design, the moving platform 12 deflects the axial tensile force of the crankshaft at a certain angle, and the deflection angle is recorded. To simulate a crankshaft under unbalanced load, the displacement of the radial piston rod 9 was then recorded. The change in displacement is used to determine whether the crankshaft's bending limit meets the design requirements.

[0023] It should be noted that during the above test, the eccentricity of the crankshaft and crank arm was... L The displacements of the radial hydraulic cylinder assembly are respectively x 1, x 2. The loading forces are respectively F 1, F 2; The torque of the hydraulic motor is M angular velocity is ω 。

[0024] This electro-hydraulic loading device for the crankshaft strength of unmanned aerial vehicles (UAVs) can simultaneously simulate the axial and radial forces encountered by the crankshaft in an UAV engine. Furthermore, it can be used to test the overall torsional bending strength of a novel lightweight crankshaft and can apply force to different parts, fully verifying the reliability of the UAV crankshaft.

[0025] Obviously, the embodiments described above are only some embodiments of this application, and not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application.

Claims

1. An electro-hydraulic loading system for testing the strength of an unmanned aerial vehicle (UAV) crankshaft, characterized in that, The electro-hydraulic loading system for testing the crankshaft strength of the unmanned aerial vehicle includes a housing (100), and the bottom of the housing (100) is provided with a base (14) for fixing the crankshaft (1). The upper sidewall of the housing (100) is provided with a radial hydraulic cylinder assembly (P1), which is arranged radially on the crankshaft (1) and cooperates with the connecting rod journal of the crankshaft (1). An axial hydraulic cylinder assembly (P2) is provided on the left side wall of the housing (100). The axial hydraulic cylinder assembly (P2) is arranged in the axial direction of the crankshaft (1). The axial hydraulic cylinder assembly (P2) cooperates with the front output shaft (5) of the crankshaft (1). The electro-hydraulic loading system for testing the crankshaft strength of the unmanned aerial vehicle also includes a rotary encoder (6), which is connected to the front output shaft (4) of the crankshaft (1).

2. The electro-hydraulic loading system for testing the crankshaft strength of an unmanned aerial vehicle (UAV) according to claim 1, characterized in that, The main journal (2) of the crankshaft (1) is fixed to the base (14) by bolts.

3. The electro-hydraulic loading system for testing the crankshaft strength of an unmanned aerial vehicle (UAV) according to claim 1, characterized in that, The radial hydraulic cylinder assembly (P1) comprises several radially arranged radial hydraulic units. Each radial hydraulic unit includes a radial hydraulic cylinder (10), a radial piston rod (9), and a hinge joint (8). The hinge joint (8) is connected to the connecting rod journal (3) of the crankshaft (1) via a connecting rod (7). The axial hydraulic cylinder assembly (P2) includes several axially arranged axial hydraulic units. The axial hydraulic unit includes an axial hydraulic cylinder (11) and an axial piston rod (16). The head of the axial piston rod (16) is provided with a disc-shaped moving platform (12). The moving platform (12) is provided with a hydraulic motor (13). The hydraulic motor (13) is connected to the front output shaft (5) of the crankshaft (1).

4. The electro-hydraulic loading system for testing the crankshaft strength of an unmanned aerial vehicle (UAV) according to claim 3, characterized in that, The radial hydraulic cylinder (10) is connected to the control center (19) through the first servo valve (15), the axial hydraulic cylinder (11) is connected to the control center (19) through the second servo valve (17), and the hydraulic motor (13) is connected to the control center (19) through the third servo valve (18).

5. A control method for an electro-hydraulic loading system for testing the crankshaft strength of an unmanned aerial vehicle as described in claim 4, characterized in that, The control method described above is used for test condition S1, test condition S2, and test condition S3. in, When performing test condition S1, the desired reciprocating motion signal of the radial piston rod (9) is set to... , Where f is the frequency of reciprocating motion; the resistance torque of the hydraulic motor (13) is set as: The tensile force of the moving platform (12) is set as follows: ;in, Both are the rated torsional torque and rated tensile force specified in the design requirements; then, the recording angle α of the hydraulic motor (13) rotation record and the feedback angle fed back by the encoder are recorded. β The difference is calculated, and the overall stiffness of the crankshaft of the new type of aviation UAV is judged based on the error to determine whether it meets the design requirements. When performing test condition S2, the desired signal of the axial piston rod (16) is set to a constant value, thereby holding the crankshaft in a fixed position by electro-hydraulic drive force to prevent rotation, and the driving torque of the hydraulic motor (13) is set to... The tensile force of the moving platform (12) is set as follows: ;in, The limit torsional torque and tensile force required during crankshaft design are then used to record the angle α recorded by the rotation of the hydraulic motor (13) and the feedback angle fed back by the encoder. β The difference is calculated, and the error is used to determine whether the ultimate torsional strength of the crankshaft of the new type of aviation UAV meets the design requirements. When performing test condition S3, the desired angle of the hydraulic motor (13) is set to 0 degrees, thereby holding the crankshaft in a fixed position by electro-hydraulic drive force to prevent rotation, and the driving force of the axial piston rod (16) is set. , To determine the ultimate tensile force specified in the crankshaft design, the moving platform (12) deflects the axial tensile force of the crankshaft at a certain angle and records the deflection angle. To simulate the crankshaft under unbalanced load, the displacement of the radial piston rod (9) was then recorded. The change in displacement is used to determine whether the crankshaft's bending limit meets the design requirements.

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