CN113740026B - A novel wind tunnel balance loading sleeve and wind tunnel balance calibration method - Google Patents

Abstract

The present invention discloses a novel wind tunnel balance loading sleeve, which is connected with a calibration load applying mechanism in a wind tunnel balance calibration system through a three-dimensional force sensor, and can accurately obtain the transferred load. Combined with the positional relationship between the three-dimensional force sensor coordinate system and the wind tunnel balance coordinate system to be calibrated, the actual load applied to the wind tunnel balance to be calibrated is obtained. The present invention provides a new wind tunnel balance body axis system calibration method, which avoids displacement measurement errors and loading load transfer errors, reduces the complexity of the calibration system, saves manufacturing costs, and reduces the difficulty of operation. The invention will have broad application prospects in the field of wind tunnel balance calibration technology.

Description

A novel wind tunnel balance loading sleeve and wind tunnel balance calibration method

Technical Field

The invention relates to a wind tunnel balance loading sleeve and a balance calibration method, belonging to the technical field of wind tunnel balance calibration.

Background technique

The wind tunnel balance is the core component in the wind tunnel force test. The accuracy of the wind tunnel balance measurement data directly affects the design of the aircraft's shape optimization, drive control, etc. Therefore, the accuracy of the wind tunnel balance is crucial in the wind tunnel force test, and one of the important links that affects the accuracy of the wind tunnel balance is the calibration of the wind tunnel balance. According to the calibration axis system of the balance, the calibration of the wind tunnel balance can be divided into the calibration of the ground axis system and the calibration of the body axis system. The calibration of the body axis system is closer to the application state of the balance, so its calibration result is also more accurate. At present, the common methods for implementing the calibration of the body axis system are mainly the mechanism reset method and the load correction method. The mechanism reset method realizes the calibration of the body axis system by restoring the balance after loading deformation to the position before loading through the movement of the mechanism, ensuring that the balance coordinate system posture remains unchanged before and after loading; the load correction method realizes the calibration of the body axis system by measuring the deformation of the balance after loading through the displacement sensor, and correcting the load applied to the balance after calculating the angle and displacement. The mechanism reset method requires the installation of a deformation displacement measurement system, a complex reset mechanism and a supporting control system. The load correction method only requires the installation of a deformation displacement measurement system. However, due to the complex deformation of the balance, the correction algorithm is usually based on a certain simplified model, and the error introduced in the load conversion process is large. In addition, both methods cannot avoid the load error introduced by friction between the calibration equipment components when the balance is loaded with lateral and axial loads. Accurate measurement of the calibration load of the wind tunnel balance is the premise and guarantee for obtaining an accurate balance formula.

The balance calibration system is an important equipment for wind tunnel balance calibration. At present, the improvement of wind tunnel balance calibration system is either from the perspective of improving the accuracy of balance displacement measurement, or from the perspective of improving the control accuracy of the reset mechanism, or reducing the friction of the load loading device, etc., but there is no optimization design from the perspective of balance calibration loading sleeve.

Summary of the invention

The purpose of the present invention is to overcome the above-mentioned defects and provide a novel wind tunnel balance loading sleeve and balance body axis calibration method. By connecting the three-dimensional force sensor arranged on the wind tunnel balance loading sleeve with the force transmission steel belt in the calibration system, the tension of the steel belt can be accurately obtained, and then the actual load on the balance to be calibrated in the balance coordinate system can be obtained. The application of the present invention to calibrate the wind tunnel balance body axis avoids displacement measurement errors and loading load errors, reduces the complexity of the calibration system, saves manufacturing costs, and reduces the difficulty of operation. It has broad application prospects in the field of wind tunnel balance calibration technology.

In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

A novel wind tunnel balance loading sleeve, as a part of a wind tunnel balance calibration system, is used to realize the calibration of the wind tunnel balance. The wind tunnel balance calibration system also includes a balance calibration frame support and a calibration load applying mechanism. The wind tunnel balance loading sleeve includes an inner sleeve, an outer sleeve and a three-dimensional force sensor.

The inner sleeve is connected to the front cone of the wind tunnel balance to be calibrated; the outer sleeve is arranged on the outside of the inner sleeve and is coaxial with the inner sleeve, and can be moved axially or rotated around the axis relative to the inner sleeve, and can be locked and fixed relative to the inner sleeve, and is used to adjust the centroid position of the outer sleeve; the three-dimensional force sensor is installed on the outer sleeve and connected to each calibration load application mechanism, and is used to measure the component force of the actual load transmitted to the wind tunnel balance to be calibrated by each calibration load in the three-dimensional direction of the sensor's own coordinate system, and then obtain the actual load on the wind tunnel balance to be calibrated in the balance coordinate system.

Furthermore, the number of the three-dimensional force sensors is equal to the number of the calibration load applying mechanisms.

Furthermore, the calibration load applying mechanism includes a steel belt, a pulley, a weight tray and a weight, wherein one end of the steel belt is connected to the three-dimensional force sensor, and the other end is connected to the weight tray with a built-in weight through the pulley.

Furthermore, the outer sleeve comprises an outer sleeve, a support arm and a locking ring; the outer sleeve is arranged outside the inner sleeve and is coaxial with the inner sleeve, and can move or rotate axially relative to the inner sleeve; the support arm is a beam structure installed outside the outer sleeve, the direction of the beam is perpendicular to the axis of the outer sleeve, and is fixed by a pin; the locking ring is sleeved on the outer sleeve, and is used to realize the locking and positioning of the outer sleeve relative to the inner sleeve, and the locking ring is an annular clamp, and the protruding ear piece at the gap of the clamp is connected by a screw to realize fixing and releasing;

The three-dimensional force sensor is arranged on the support arm and the outer cylinder, and is connected to each calibration load applying mechanism;

The inner sleeve is provided with a tapered hole matched with the front cone of the wind tunnel balance to be calibrated, and the tapered hole matches with the front cone of the wind tunnel balance to be calibrated to achieve the connection between the inner sleeve and the front cone of the wind tunnel balance to be calibrated.

Furthermore, the number of the locking rings is not less than 2;

There is one support arm and the centroid of the support arm coincides with the centroid of the outer cylinder; or there are two support arms, the centroids of the two support arms are located on the axis of the outer cylinder and are equidistant from the centroid of the outer cylinder.

Furthermore, the number of the three-dimensional force sensors is equal to the number of the force transmission steel belts in the wind tunnel balance calibration system.

A wind tunnel balance calibration method is implemented by using the novel wind tunnel balance loading sleeve, comprising the following steps:

Step S1: Install the balance support rod of the wind tunnel balance to be calibrated on the balance calibration frame support, and adjust the balance posture;

Step S2: connecting the inner sleeve of the balance loading sleeve to the wind tunnel balance to be calibrated;

Step S3: installing the outer sleeve of the balance loading sleeve, adjusting the position of the outer sleeve relative to the inner sleeve until the geometric centroid of the outer sleeve coincides with the calibration center of the wind tunnel balance to be calibrated, and locking and fixing;

Step S4: adjusting the position of the load applying mechanism and connecting each calibration load applying mechanism to its corresponding three-dimensional force sensor;

Step S5: applying a calibration load to the wind tunnel balance to be calibrated according to a preset load table through a calibration load applying mechanism;

Step S6: acquiring, through each three-dimensional force sensor, the three-component force loads _f'x , _f'y , _f'z of the actual loads transmitted by each calibration load to the wind tunnel balance to be calibrated in the sensor's own coordinate system _O'xyz ;

Step S7: Obtain the actual load of the balance to be calibrated in the balance coordinate system _Oxyz from _f'x , _f'y , _f'z and the positions of the three-dimensional force sensors in the balance coordinate system;

Step S8 obtains a balance formula according to the actual load of the wind tunnel balance to be calibrated and the output result of the wind tunnel balance to be calibrated.

Further, step S7 includes the following steps:

S71 obtains the actual load of the calibration balance at the position of each three-dimensional force sensor in the balance coordinate system _Oxyz based on the three-component force loads _f'x , _f'y , _f'z in the sensor coordinate system _O'xyz obtained by each three-dimensional force sensor and the position ( _lx , _ly , _lz ) of each three-dimensional force sensor in the balance coordinate system;

S72 superimposes the actual loads of the calibration balance at the positions of the three-dimensional force sensors to obtain the actual load of the calibration balance in the balance coordinate system O _xyz .

Furthermore, in step S71, the calculation formula for the actual load of the calibration balance at each three-dimensional force sensor position is:

_F'x , _F'y , _F'z , _M'x , _M'y , _M'z are the actual six-component loads of the wind tunnel balance to be calibrated at the positions of the three-dimensional force sensors (3) in the balance coordinate system _Oxyz .

Furthermore, in step S72,

_Fx , _Fy , _Fz , _Mx , _My , _Mz are the actual loads of the calibration balance in the balance coordinate system _Oxyz ; _F'xi , _F'yi , _F'zi , _M'xi , _M'yi , _M'zi are the actual loads of the calibration balance at the i-th three-dimensional force sensor position in the balance coordinate system _Oxyz , 1≤i≤n, n is the number of three-dimensional force sensors.

Furthermore, the calibration load applying mechanism includes a steel belt, a pulley, a weight tray and a weight. In step S4, the position of the load applying mechanism is adjusted, and each calibration load applying mechanism is connected to its corresponding three-dimensional force sensor by connecting one end of the steel belt to the three-dimensional force sensor and the other end to the weight tray with built-in weights through a pulley, and then adjusting the pulley position to make the steel belt parallel to the corresponding coordinate axis in the balance coordinate system;

In step S6, each three-dimensional force sensor obtains the actual load transmitted by each calibration load to the wind tunnel balance to be calibrated as the tension of the steel belt connected thereto, which is expressed in the form of component forces _fx ', _fy ' and _fz ' in the sensor's own coordinate system _O'xyz .

Compared with the prior art, the present invention has the following beneficial effects:

(1) In the wind tunnel balance calibration sleeve of the present invention, the loading load applied during the balance calibration process can be accurately obtained, eliminating the influence of friction during the load transfer process and the deformation of the wind tunnel balance under load;

(2) In the wind tunnel balance calibration method of the present invention, there is no need to add a balance deformation displacement measurement system, thus avoiding displacement measurement errors;

(3) In the wind tunnel balance calibration method of the present invention, there is no need to add a reset mechanism and a control system, which reduces the complexity of the calibration system and saves manufacturing costs;

(4) In the wind tunnel balance calibration method of the present invention, the applied loading load is directly measured by multiple three-dimensional force sensors to obtain the actual load on the wind tunnel balance to be calibrated in the balance coordinate system, which can shorten the balance loading time and improve the balance calibration efficiency;

(5) In the wind tunnel balance calibration method of the present invention, compared with the existing calibration methods and processes, the load error of the balance calibration process is smaller and the calibration formula is more accurate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is an overall schematic diagram of a novel wind tunnel balance loading sleeve according to the present invention;

FIG2 is a schematic diagram of an inner sleeve in a novel wind tunnel balance loading sleeve of the present invention;

FIG3 is an assembly diagram of an outer sleeve and a three-dimensional force sensor in a novel wind tunnel balance loading sleeve of the present invention;

FIG4 is a schematic diagram of a locking ring in a loading sleeve of a novel wind tunnel balance according to the present invention;

FIG5 is a schematic diagram of the installation of a novel wind tunnel balance loading sleeve for calibrating a wind tunnel balance according to the present invention;

FIG6 is a schematic diagram of a wind tunnel balance calibration using a novel wind tunnel balance loading sleeve of the present invention;

FIG. 7 is a schematic diagram showing the deformation of the loading sleeve of the present invention following the wind tunnel balance to be calibrated after the calibration load is loaded.

Detailed ways

The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

The present invention discloses a novel wind tunnel balance loading sleeve, comprising: an inner sleeve 1, an outer sleeve 2 and a three-dimensional force sensor 3. The inner sleeve 1 is connected to the balance, the outer sleeve 2 is sleeved on the inner sleeve 1 to form a cylindrical fit, the three-dimensional force sensor 3 is fixed at a specified position of the outer sleeve 2, and the origin of the coordinate system of the three-dimensional force sensor is the point of application of force when the wind tunnel balance is calibrated. When the wind tunnel balance of the present invention is calibrated, the application of any component load of the balance is achieved by transferring the gravity of different weight strings to the specified position of the outer sleeve 2 through multiple steel belts. One end of the steel belt in the balance calibration system is connected to the three-dimensional force sensor 3 at the specified position of the outer sleeve 2, and the connection point is the origin of the coordinate system of the three-dimensional force sensor 3, and the other end is connected to the weight tray for bearing the load. The three-dimensional force sensor can directly measure the load on the steel belt connected to it, avoiding the load error generated during the force transmission process of the steel belt. The actual load of the wind tunnel balance to be calibrated is calculated according to the force load information measured by the three-dimensional force sensor, and is used to calculate the balance formula. Compared with directly using the weight of the weight to calculate the balance formula, its accuracy is higher.

The present invention provides a new body axis system calibration method for wind tunnel balance calibration, which overcomes the problems of complex balance calibration system, low work efficiency, large error of displacement correction method, etc. in the existing mechanism reset method. At the same time, no matching deformation displacement measurement system and reset mechanism are required, which reduces the complexity of the calibration system, saves manufacturing costs, and improves work calibration efficiency. It has broad application prospects in the field of wind tunnel balance calibration technology.

As shown in FIG1 , a novel wind tunnel balance loading sleeve includes an inner sleeve 1, an outer sleeve 2 and a three-dimensional force sensor 3, which serves as the main load-bearing, transmission and measurement component during load loading in a wind tunnel balance calibration system.

FIG. 2 shows the inner sleeve 1 of the present invention. The inner sleeve 1 is cylindrical and has a tapered hole section inside for cooperating with the front cone of the wind tunnel balance to be calibrated.

FIG3 is an assembly diagram of the outer sleeve 2 and the three-dimensional force sensor 3 of the present invention. The outer sleeve includes an outer sleeve 21, a support arm 22 and a locking ring 23. The outer sleeve 21 is cylindrical, and its inner diameter is consistent with the outer diameter of the inner sleeve 1, forming a cylindrical fit. The outer sleeve 21 can slide and rotate on the inner sleeve 1 along its axis; the support arm 22 is a crossbeam with a thick middle and thin ends, and there is a through hole in the middle position. The inner diameter of the through hole is consistent with the outer diameter of the outer sleeve 21. The support arm 22 is sleeved on the outer side of the outer sleeve 21 through the through hole and connected and fixed by a pin; the locking ring 23 (FIG4) includes a circular ring-shaped body with a gap at one end, and protruding ears respectively arranged on both sides of the gap. The screw passes through the two ears. Tightening the screw can reduce the gap and the inner diameter of the ring. The inner diameter of the locking ring 23 is consistent with the outer diameter of the outer sleeve 21. It is sleeved on the outer sleeve 21. Tightening the screw can fix the outer sleeve 2 on the inner sleeve 1. The three-dimensional force sensor 3 is a sensor that can measure the three force vectors Fx, Fy and Fz in a Cartesian coordinate system. It is installed on the outer sleeve 2. The position and number of the three-dimensional force sensor 3 are determined according to the form of the balance loading sleeve and the calibration load of the wind tunnel balance to be calibrated.

Furthermore, the outer sleeve 2 can be an I-shape or a X-shape. When the outer sleeve 2 contains one support arm, the outer sleeve 2 is a X-shape; when the outer sleeve 2 contains two support arms, the outer sleeve 2 is an I-shape. The extension direction of the support arm, i.e., the direction of the cross beam, is perpendicular to the axis of the outer tube and is fixedly connected to the outer tube by pins.

Further, there is one support arm 22 and the centroid of the support arm 22 coincides with the centroid of the outer cylinder 21; or there are two support arms 22, the centroids of the two support arms 22 are located on the axis of the outer cylinder 21 and are equidistant from the centroid of the outer cylinder 21.

Furthermore, the three-dimensional force sensor 3 is cylindrical, the origin of its coordinate system is the connection point with the steel belt, and measures the three-dimensional forces F _x , F _y and F _z in space without torque components.

Furthermore, the number of the locking rings 23 is not less than 2.

Furthermore, the position where the three-dimensional force sensor 3 is fixed on the outer sleeve 2 is relatively fixed in the balance coordinate system.

Furthermore, as shown in FIG5 , the wind tunnel balance to be calibrated is usually a rod type, with one end connected to the inner sleeve 1 and the other end connected to the balance support rod. The wind tunnel balance to be calibrated is completely placed in the inner sleeve 1, and the balance support rod is partially placed in the inner sleeve 1 with sufficient clearance between the balance support rod and the inner sleeve 1. The other end of the balance support rod is fixed, thereby forming a cantilever state.

The present invention adopts the above-mentioned novel wind tunnel balance loading sleeve to implement a wind tunnel balance calibration method, which includes:

Figure 6 is a schematic diagram of a wind tunnel balance loading sleeve installed in a wind tunnel balance calibration system for calibrating a wind tunnel balance. A wind tunnel balance calibration system generally includes a balance calibration frame and a calibration load applying mechanism, preferably, the calibration load applying mechanism includes a steel belt, a pulley, a weight tray and a weight;

(1) Fix the balance support rod system on which the wind tunnel balance to be calibrated is installed on the balance calibration frame support;

(2) Connect the inner sleeve 1 of the balance loading sleeve to the balance to be calibrated, the tapered hole section of the inner sleeve 1 forms a cone fit with the front cone of the balance, and tighten and fix it with bolts;

(3) Install the outer sleeve 2 of the balance loading sleeve. The outer sleeve 2 and the inner sleeve 1 are cylindrically matched. According to the position of the balance center to be calibrated, adjust the position of the outer sleeve 2 relative to the inner sleeve 1 until the geometric centroid of the outer sleeve coincides with the balance center. Use the locking ring 23 to fix the outer sleeve 2 so that it cannot move;

(4) Connect the end of the steel belt that is not connected to the weight tray (for loading the weight) to the three-dimensional force sensor 3 on the loading sleeve, and at the same time, the steel belt passes around the pulley (i.e., the reversing mechanism); adjust the position of the pulley so that the steel belt is parallel to the corresponding coordinate axis in the balance coordinate system;

(5) When calibrating a wind tunnel balance, according to the calibration load requirements, a specified weight is loaded on one or more weight trays, and the weight G is transferred to the loading sleeve through a steel belt. The loading sleeve is fixedly connected to the balance to be calibrated, thereby realizing the loading of the load of the balance to be calibrated, that is, the force on the loading sleeve is equal to the force on the balance to be calibrated. In this process, due to the existence of the friction force f at the pulley, the pulling force F _{pull on} the loading sleeve after the steel belt passes around the pulley is less than the applied weight G, and the applied weight G is not fully transferred to the wind tunnel balance through the steel belt and the loading sleeve; on the other hand, the balance will deform after being loaded, and the direction of the steel belt connected to the loading sleeve is no longer parallel to the corresponding coordinate axis of the balance coordinate system O _xyz . The steel belt pulling force F _pull is not the load of the specified axis of the balance. When calculating the balance formula, if the weight G is still used as the load on the balance to be calibrated, a large calibration load error will inevitably be introduced.

G＝F_拉+f (1)

(6) Taking one of the calibration load application mechanisms as an example for analysis, after the weights are loaded, the deformation of the loading sleeve following the balance is shown in Figure 7. The balance loading sleeve is fixedly connected to the wind tunnel balance to be calibrated. The deformation of the balance to be calibrated will not affect the orientation of the three-dimensional force sensor coordinate system _O'xyz in the balance coordinate system _Oxyz . Since the position of the pulley remains unchanged, the steel belt tension _Fpull will no longer be parallel to any axis in the two coordinate systems, that is, there is an angle between the steel belt tension _Fpull and each axis in the three-dimensional force sensor coordinate system _O'xyz . Among them, the connection point between the three-dimensional force sensor 3 and the steel belt is the origin of its coordinate system _O'xyz . According to the principle of force composition and decomposition, the resultant force Fpull of its measurement components _fx ', _fy ' and _fz ' is _equal to the tension _Fpull of the steel belt connected to it;

(7) Since the geometric center of the balance loading sleeve coincides with the balance center, and the position of the three-dimensional force sensor 3 is fixed, the position of the three-dimensional force sensor 3 in the balance coordinate system is known, that is, the position coordinates ( _lx , _ly , lz) of the origin of the coordinate system _O'xyz in the balance coordinate system _Oxyz are known. The actual load measured by the three-dimensional force sensor 3 is converted to the balance coordinate system _Oxyz , thereby obtaining the actual load ( _Fx , _Fy , Fz, _Mx , _{My , Mz} ) of the wind tunnel balance to be calibrated in the accurate _balance coordinate system. The specific relationships between the above parameters are shown in the following formulas.

The above calculation process is performed for each three-dimensional force sensor (numbered 1 to n), and then the load converted to the balance coordinate system O _xyz is superimposed to obtain the actual load of each component of the wind tunnel balance to be calibrated under the loading load.

(8) Calculate the balance formula based on the actual load of the wind tunnel balance to be calibrated and its corresponding output result.

Compared with the existing wind tunnel balance calibration method, the present invention can not only realize the calibration of the balance body axis system, but also simplify the calibration system and improve the calibration efficiency. More importantly, the load error is small during the balance calibration process and the calibration accuracy of the balance is improved.

Example 1

The specific dimensions of the present invention can be designed according to the load of the wind tunnel balance to be calibrated, and the principle is that the strength and rigidity are large and the weight is light. In this embodiment, the inner sleeve has an inner diameter of 40 mm, an outer diameter of 45 mm, and a length of 300 mm. The inner sleeve of the outer sleeve has an inner diameter of 45 mm, an outer diameter of 50 mm, and a length of 240 mm. A two-arm structure is adopted, and the arm and the outer cylinder form an "I" shape. The arm is 240 mm long, and the number of three-dimensional force sensors is 9.

The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims (11)

1. A novel wind tunnel balance loading sleeve, as a part of a wind tunnel balance calibration system, is used to realize the calibration of the wind tunnel balance. The wind tunnel balance calibration system also includes a balance calibration frame and a calibration load applying mechanism, characterized in that it includes an inner sleeve (1), an outer sleeve (2) and a three-dimensional force sensor (3); The inner sleeve (1) is connected to the front cone of the wind tunnel balance to be calibrated; the outer sleeve (2) is arranged outside the inner sleeve (1) and is coaxial with the inner sleeve, and can move along the axial direction or rotate around the axis relative to the inner sleeve (1), and can be locked and fixed relative to the inner sleeve (1), and is used to adjust the centroid position of the outer sleeve (2); the three-dimensional force sensor (3) is installed on the outer sleeve (2) and is connected to each calibration load application mechanism, and is used to measure the component force of the actual load transmitted to the wind tunnel balance to be calibrated by each calibration load in the three-dimensional direction in the sensor coordinate system, thereby obtaining the actual load on the wind tunnel balance to be calibrated in the balance coordinate system. 2. A novel wind tunnel balance loading sleeve according to claim 1, characterized in that the number of the three-dimensional force sensors (3) is equal to the number of the calibration load applying mechanisms. 3. According to a new type of wind tunnel balance loading sleeve as described in claim 1, it is characterized in that the calibration load application mechanism includes a steel belt, a pulley, a weight tray and a weight, one end of the steel belt is connected to the three-dimensional force sensor (3), and the other end is connected to the weight tray with built-in weights through the pulley. 4. A novel wind tunnel balance loading sleeve according to claim 1, characterized in that the outer sleeve (2) comprises an outer sleeve (21), a support arm (22) and a locking ring (23); the outer sleeve (21) is arranged on the outside of the inner sleeve (1) and is coaxial with the inner sleeve, and can move or rotate axially relative to the inner sleeve (1); the support arm (22) is a beam structure installed on the outside of the outer sleeve (21), the direction of the beam is perpendicular to the axis of the outer sleeve (21), and is fixed by a pin; the locking ring (23) is sleeved on the outer sleeve (21) to achieve locking and positioning of the outer sleeve relative to the inner sleeve (1), and the locking ring (23) is an annular clamp, which is connected to the protruding ear piece at the gap of the clamp by screws to achieve fixing and release; The three-dimensional force sensor (3) is arranged on the support arm (22) and the outer cylinder (21), and is connected to each calibration load applying mechanism in the wind tunnel balance calibration system; The inner sleeve (1) is provided with a tapered hole that matches with the front cone of the wind tunnel balance to be calibrated, and the tapered hole matches with the front cone of the wind tunnel balance to be calibrated, thereby achieving the connection between the inner sleeve (1) and the front cone of the wind tunnel balance to be calibrated. 5. A novel wind tunnel balance loading sleeve according to claim 4, characterized in that the number of the locking rings (23) is not less than 2; There is one support arm (22) and the centroid of the support arm (22) coincides with the centroid of the outer cylinder (21); or there are two support arms (22), the centroids of the two support arms (22) are located on the axis of the outer cylinder (21) and are equidistant from the centroid of the outer cylinder (21). 6. A novel wind tunnel balance loading sleeve according to claim 3, characterized in that the number of the three-dimensional force sensors (3) is equal to the number of force transmission steel belts in the wind tunnel balance calibration system. 7. A method for calibrating a wind tunnel balance, characterized in that it is implemented by using a novel wind tunnel balance loading sleeve as claimed in any one of claims 1 to 6, comprising the following steps: Step S1: Install the balance support rod of the wind tunnel balance to be calibrated on the balance calibration frame, and adjust the balance posture; Step S2: connecting the inner sleeve (1) of the balance loading sleeve to the wind tunnel balance to be calibrated; Step S3: installing the outer sleeve (2) of the balance loading sleeve, adjusting the position of the outer sleeve (2) relative to the inner sleeve (1) until the geometric centroid of the outer sleeve (2) coincides with the calibration center of the wind tunnel balance to be calibrated, and locking and fixing; Step S4: adjusting the position of the load applying mechanism and connecting each calibration load applying mechanism to its corresponding three-dimensional force sensor (3); Step S5: applying a calibration load to the wind tunnel balance to be calibrated according to a preset load table through a calibration load applying mechanism; Step S6: obtaining, through each three-dimensional force sensor (3), the three-component force loads _f'x , _f'y , _f'z in the sensor coordinate system _O'xyz, of the actual loads applied by each calibration load applying mechanism connected thereto to the wind tunnel balance to be calibrated; Step S7: Obtain the actual load of the balance to be calibrated in the balance coordinate system _Oxyz from the _f'x , _f'y , _f'z acquired by each three-dimensional force sensor (3) and the position of each three-dimensional force sensor in the balance coordinate system; Step S8 obtains a balance formula according to the actual load of the wind tunnel balance to be calibrated and the output result of the wind tunnel balance to be calibrated. 8. A wind tunnel balance calibration method according to claim 7, characterized in that said step S7 comprises the following steps: S71 obtains the actual load of the calibration balance at the position of each three-dimensional force sensor (3) in the balance coordinate system _Oxyz from the three-component force loads _f'x , _f'y , _f'z in the sensor coordinate system _O'xyz obtained by each three-dimensional force sensor (3) and the position ( _lx , _ly , _lz ) of each three-dimensional force sensor in the balance coordinate system; S72 superimposes the actual loads of the calibration balance at the positions of the three-dimensional force sensors (3) to obtain the actual load of the calibration balance in the balance coordinate system O _xyz . 9. A wind tunnel balance calibration method according to claim 8, characterized in that, in step S71, the calculation formula for the actual load of the calibration balance at the position of each three-dimensional force sensor (3) is: _F'x , _F'y , _F'z , _M'x , _M'y , _M'z are the actual six-component loads of the wind tunnel balance to be calibrated at the positions of the three-dimensional force sensors (3) in the balance coordinate system _Oxyz . 10. A wind tunnel balance calibration method according to claim 9, characterized in that in step S72, _Fx , _Fy , _Fz , _Mx , _My , _Mz are actual loads of the calibration balance in the balance coordinate system _Oxyz ; _F'xi , _F'yi , _F'zi , _M'xi , _M'yi , _M'zi are actual loads of the calibration balance at the position of the i-th three-dimensional force sensor (3) in the balance coordinate system _Oxyz , 1≤i≤n, and n is the number of three-dimensional force sensors. 11. A wind tunnel balance calibration method according to claim 7, characterized in that the calibration load applying mechanism comprises a steel belt, a pulley, a weight tray and a weight, and in said step S4, the method of adjusting the position of the load applying mechanism and connecting each calibration load applying mechanism with its corresponding three-dimensional force sensor (3) is to connect one end of the steel belt with the three-dimensional force sensor (3), and connect the other end with the weight tray on which the weight is placed through the pulley, and then adjust the position of the pulley to make the steel belt parallel to the corresponding coordinate axis in the balance coordinate system; In step S6, each three-dimensional force sensor (3) obtains the actual load transmitted by each calibration load to the wind tunnel balance to be calibrated as the tension of the steel belt connected thereto, and the steel belt tension is expressed in the form of component forces _fx ', _fy ' and _fz ' in the sensor's own coordinate system _O'xyz .