A method for adjusting and verifying the hinge moment of a helicopter blade

Abstract

The present application belongs to the field of single hydraulic helicopter rotor hinge moment adjustment, and particularly relates to a method for adjusting and verifying the hinge moment of a helicopter blade. The method comprises the following steps: step one, determining a combination matrix of the weight and the angle of the trailing edge adjustment piece; step two, according to the combination matrix, distributing the weight and the angle of the counterweight in different tests by using counterweights with different weights; step three, measuring the rotor hinge moment by using the rotor tower test, determining the change range of the rotor hinge moment, and performing dynamic balance test on the blade to determine the dynamic balance result of the blade, and selecting the adjustment counterweight and the angle combination scheme corresponding to the hinge moment meeting the dynamic balance requirement; step four, performing test flight test according to the adjustment counterweight and the angle combination scheme selected in step three; and step five, taking the adjustment counterweight and the angle combination scheme meeting the requirement and the control force within the predetermined threshold as the final hinge moment adjustment scheme.

Description

Technical Field

[0001] This invention belongs to the field of single hydraulic helicopter rotor hinge torque adjustment, specifically relating to a method for adjusting and verifying helicopter rotor hinge torque. Background Technology

[0002] Helicopter control relies heavily on hydraulic power, and light helicopters typically have only a single hydraulic system. When this system fails, the helicopter loses its hydraulic power, requiring manual control. This necessitates a low rotor hinge torque to ensure a safe landing. Excessive rotor hinge torque makes control extremely difficult and could even lead to a crash.

[0003] However, helicopters have complex control structures and long control system circuits. The calculations and analyses of hinge torque during the design phase often deviate significantly from reality, making it difficult to detect hinge torque issues promptly. Excessive hinge torque is only discovered at a certain stage of flight testing. Current solutions often involve redesigning the rotor or rotor blades to reduce hinge torque, which is extremely labor-intensive, costly, time-consuming, and significantly impacts project schedules. Therefore, a new method for adjusting and verifying hinge torque is urgently needed. Summary of the Invention

[0004] Purpose of the invention: To provide a method for adjusting and verifying the hinge torque of helicopter rotor blades, which achieves adjustment and reduction of hinge torque without changing the existing rotor design or damaging the blade structure, and then verifies the adjustment.

[0005] Technical solution:

[0006] A method for adjusting and verifying the hinge torque of a helicopter rotor blade, the method utilizing a front counterweight support, a rear counterweight support, a balance counterweight plate, and a trailing edge adjustment plate, wherein the trailing edge adjustment plate comprises n trailing edge adjustment sub-plates T1 to Tn sequentially from the blade tip to the blade root, where n is a positive integer, the method comprising:

[0007] Step 1: Determine the unit counterweight weight and the unit trailing edge trimmer angle, analyze the influence of the unit counterweight weight and the unit trailing edge trimmer angle on the blade hinge torque, and formulate a combination matrix of counterweight and trailing edge trimmer angle based on the unit counterweight weight and the unit trailing edge trimmer angle; wherein, the initial counterweight and initial angle in the combination matrix are the counterweight and angle after the blade static balance and dynamic balance adjustment.

[0008] Step 2: Using balance weights of different weights, distribute the initial weight and initial angle in different trials, taking into account the initial weight and initial angle.

[0009] sequentially assigning other weights and other angles in the combination matrix to different weights of the balance weight pieces in different tests;

[0010] Step three: determining the range of rotor hinge moment by measuring the rotor hinge moment in different tests in step two using the rotor tower test, and determining the rotor blade dynamic balance result by performing the rotor blade dynamic balance test, and selecting the adjustment weight and angle combination corresponding to the hinge moment meeting the dynamic balance requirement;

[0011] Step four: performing the test flight test according to the adjustment weight and angle combination selected in step three;

[0012] Step five: taking the adjustment weight and angle combination scheme meeting the test flight test data requirements and the control force within the predetermined threshold as the final hinge moment adjustment scheme.

[0013] Further, in step one, the unit weight of the weight and the unit angle of the trailing edge adjustment piece are determined, specifically: the unit weight of the weight and the unit angle of the trailing edge adjustment piece are measured on the rotor tower.

[0014] Further, in step two, the initial weight and the initial angle are assigned, and the other weight and the other angle are assigned, specifically: the balance weight pieces are assigned in the front weight support and the rear weight support, and the angles of the trailing edge adjustment sub-pieces are adjusted.

[0015] Further, in step two, the angles of the trailing edge adjustment sub-pieces are adjusted, specifically including: each trailing edge adjustment sub-piece is single-folded by 1° from the initial angle.

[0016] Further, in step two, the angles of the trailing edge adjustment sub-pieces are adjusted, specifically including: the adjustment angle of each trailing edge adjustment sub-piece is maximally foldable by ±5° relative to the initial angle.

[0017] Further, step five further includes: in the case that the test data does not meet the requirements or the control force is not within the predetermined threshold, adjusting the weight and angle combination until the test data meets the requirements and the control force is within the predetermined threshold.

[0018] Further, in step six, the rotor blade hinge moment corresponding to the final hinge moment adjustment scheme is transmitted to the standard rotor blade through the rotor blade dynamic balance table, the remaining rotor blades are adjusted using the standard rotor blade, and the consistency of the rotor blade hinge moment is ensured.

[0019] Further, the balance weight pieces include 2g, 5g, 10g, 25g and 50g, a total of 5 specifications.

[0020] Beneficial effects:

[0021] The application provides a rotor hinge moment adjustment and verification method for a single hydraulic system helicopter without subversion design, and the method can effectively solve the problem of excessive rotor hinge moment. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A schematic diagram for adjusting the position of a blade;

[0023] Figure 2 A structure diagram of a front counterweight support;

[0024] Figure 3 A structure diagram of a rear counterweight support;

[0025] Figure 4 A structure diagram of a balance weight;

[0026] Figure 5 A schematic diagram of a trailing edge adjustment piece.

[0027] Among them, the front counterweight support 1, the rear counterweight support 2, the balance weight piece 3, and the trailing edge adjustment piece 4. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the application clearer, the technical scheme in the application embodiment will be described in more detail below in combination with the drawings in the application embodiment. In the drawings, the same or similar notations represent the same or similar elements or elements with the same or similar functions throughout. The described embodiments are part of the embodiments of the application, not all of the embodiments. The embodiments described below by referring to the drawings are exemplary and are intended to explain the application, and cannot be understood as a limitation on the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0029] In the description of the application, it should be understood that the terms "center", "axial", "vertical", "upper", "lower", "upper end", "bottom end", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the application.

[0030] The embodiments of the application will be described in detail below in combination with the drawings.

[0031] Rotor blades usually have balance weights and trailing edge tabs, both of which are usually used to adjust the blade dynamic balance, and the process of adjusting the blade dynamic balance also affects the blade hinge moment. Based on this, the patent proposes a method for adjusting and verifying the hinge moment of a helicopter blade, which reduces the hinge moment without changing the existing rotor design and damaging the blade structure.

[0032] To solve the above technical problems, the present application provides a method for adjusting and verifying the hinge moment of a helicopter blade, which adjusts the hinge moment by using the influence of rotor blade dynamic balance weight on the chord center of gravity and the influence of trailing edge tab on the aerodynamic center of the blade, measures and analyzes the influence of dynamic balance weight and trailing edge tab angle on the hinge moment by using the rotor tower, measures and analyzes the adjustable range of rotor hinge moment, evaluates and fine-tunes the adjusted hinge moment by using test data and pilot control feeling, and transfers the adjusted hinge moment of the blade to the standard blade by using the blade dynamic balance table, adjusts the remaining blades by using the standard blade, and ensures the consistency of the blade hinge moment.

[0033] As Figures 1-5 Each blade has a front weight support 1 and a rear weight support 2, and the balance weight piece 3 has 5 specifications of 2g, 5g, 10g, 25g and 50g. The trailing edge tab 4 includes n trailing edge adjustment sub-pieces T1 to Tn from the blade tip to the blade root, n is a positive integer, and the nth adjustment piece is generally used for field adjustment, Figure 5 6 pieces are exemplarily shown in the middle.

[0034] The method of the present application changes the blade hinge moment by adjusting the front weight support 1, the rear weight support 2, the balance weight piece 3 and the trailing edge tab 4, and tests and adjusts the hinge moment by using the blade dynamic balance table and the rotor tower, and transfers the hinge moment. The method of the present application comprises the following steps:

[0035] Step one: measure the unit weight of the weight and the unit angle of the trailing edge tab on the rotor tower, analyze the influence of the unit weight of the weight and the unit angle of the trailing edge tab on the blade hinge moment, and formulate a combination matrix of the weight and the angle of the trailing edge tab according to the unit weight and the unit angle; wherein the initial weight and the initial angle in the combination matrix are the weight and the angle after the blade static balance and dynamic balance adjustment.

[0036] Step two: for the initial weight and the initial angle, use balance weight pieces 3 of different weights to distribute the weight equal to the initial weight in different tests, specifically the distribution of the balance weight piece 3 in the front weight support 1 or the rear weight support 2 and the angle of the trailing edge adjustment sub-piece Tn.

[0037] In turn, for other weights in the combination matrix and other angles, the balance weight piece 3 with different weights is used in different tests to allocate weights equal to the weights of the other weights and the other angles, specifically: the allocation of the balance weight piece 3 in the front weight support 1 or the rear weight support 2 and the angle of each rear edge adjustment sub-piece;

[0038] The rear edge adjustment sub-piece Tn is bent by 1° at a time from the initial angle. The adjustment angle of the rear edge adjustment sub-piece Tn can be bent by ±5° at most relative to the initial angle.

[0039] Step three: the rotor hinge moment in different tests is measured by using the rotor tower test, the change range of the rotor hinge moment is determined, and the dynamic balance test of the blade is performed to determine the blade dynamic balance result, and the adjustment weight and angle combination corresponding to the hinge moment meeting the dynamic balance requirement are selected;

[0040] Step four: test flight is performed according to the adjustment weight and angle combination scheme selected in step three;

[0041] Step five: the adjustment weight and angle combination meeting the requirement and the control force within the predetermined threshold value in the test flight test data are taken as the final hinge moment adjustment scheme.

[0042] Further comprising: in the case that the test data does not meet the requirement or the control force is not within the predetermined threshold value, adjusting the weight and angle combination until the test data meets the requirement and the control force is within the predetermined threshold value.

[0043] Step six: the blade hinge moment corresponding to the final hinge moment adjustment scheme is transmitted to the standard blade through the blade dynamic balance table, the remaining blades are adjusted by using the standard blade, and the consistency of the blade hinge moment is ensured.

[0044] After the rotor hinge moment is adjusted by the above method, the hinge moments of all installed blades are within an acceptable range and have consistency, so that the huge workload caused by repeated design can be avoided, and resources and time can be saved.

[0045] The method of the application does not change the existing rotor design; does not damage the blade structure; cleverly uses the influence of the rotor blade dynamic balance weight on the chord-wise center of gravity of the blade; cleverly uses the influence of the rear edge adjustment piece on the aerodynamic center of the blade; measures and analyzes the adjustable range of the rotor hinge moment by using the rotor tower; fine-tunes by using the test flight test data and the pilot's control feeling; transmits the blade hinge moment by using the blade dynamic balance table; and realizes that the hinge moments of all installed blades are within an acceptable range and have consistency.

[0046] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of adjustment and verification of the hinge moment of a helicopter blade, by means of a front balance support, a rear balance support, a balance weight, a rear edge adjustment tab, wherein, The trailing edge adjustment piece comprises n trailing edge adjustment sub-pieces T1 to Tn from the blade tip to the blade root, n being a positive integer, and the method is characterized in that the method is used for a single-hydraulic-system helicopter, and the method comprises the following steps: Step one: determining unit weight of counterweight and unit angle of trailing edge adjustment piece, analyzing the influence of unit weight of counterweight and unit angle of trailing edge adjustment piece on blade hinge moment, and formulating a combination matrix of counterweight and angle of trailing edge adjustment piece according to the unit weight of counterweight and the unit angle of trailing edge adjustment piece; wherein the initial counterweight and the initial angle in the combination matrix are the counterweight and the angle after static balance and dynamic balance adjustment of the blade; Step two: for the initial counterweight and the initial angle, using balance counterweight pieces of different weights, the initial counterweight and the initial angle are allocated in different tests; for other counterweights and other angles in the combination matrix, using balance counterweight pieces of different weights, the other counterweights and the other angles are allocated in different tests, and the adjustment angle of each trailing edge adjustment sub-piece can be bent by ±5° relative to the initial angle at most; Step three: measuring the rotor hinge moment in different tests in step two by using the rotor tower test, determining the change range of the rotor hinge moment, and testing the dynamic balance of the blade to determine the dynamic balance result of the blade, and selecting the adjustment counterweight and angle combination corresponding to the hinge moment meeting the dynamic balance requirement; Step four: performing test flight test according to the adjustment counterweight and angle combination selected in step three; Step five: taking the adjustment counterweight and angle combination scheme meeting the requirement and having the control force within the predetermined threshold as the final hinge moment adjustment scheme; Step six: transmitting the blade hinge moment corresponding to the final hinge moment adjustment scheme to the standard blade through the blade dynamic balance platform, adjusting the remaining blades by using the standard blade, and ensuring the consistency of the blade hinge moment.

2. The method of adjustment and verification of the hinge moment of a helicopter blade according to claim 1, characterized in that, In step one, the unit weight of counterweight and the unit angle of trailing edge adjustment piece are determined, specifically: the unit weight of counterweight and the unit angle of trailing edge adjustment piece are measured on the rotor tower.

3. The method of adjustment and verification of the hinge moment of a helicopter blade according to claim 1, characterized in that, In step two, the initial counterweight and the initial angle are allocated and the other counterweight and the other angle are allocated, specifically: balance counterweight pieces are allocated in the front counterweight support and the rear counterweight support, and the angle of each trailing edge adjustment sub-piece is adjusted.

4. The method of adjustment and verification of the hinge moment of a helicopter blade according to claim 3, characterized in that, In step two, the angle of each trailing edge adjustment sub-piece is adjusted, specifically including: each trailing edge adjustment sub-piece is bent by 1° at a time from the initial angle.

5. The method of adjustment and verification of the hinge moment of a helicopter blade according to claim 1, characterized in that, Step five further includes: in the case that the test data does not meet the requirement or the control force is not within the predetermined threshold, adjusting the counterweight and angle combination until the test data meets the requirement and the control force is within the predetermined threshold.

6. The method of adjustment and verification of the hinge moment of a helicopter blade according to claim 1, characterized in that, The balance counterweight piece includes 2g, 5g, 10g, 25g and 50g in total 5 specifications.

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