Dynamic supporting device and method with small size, low damping and high bearing pitching freedom degree

Abstract

The invention belongs to the technical field of high-speed wind tunnel dynamic tests, and discloses a small-size low-damping high-bearing pitching degree-of-freedom dynamic supporting device and method.The dynamic supporting device comprises a dynamic test model front section, a force measuring balance and a dynamic test model rear section which are sequentially connected from front to back, and the dynamic test model front section, the force measuring balance and the dynamic test model rear section are arranged on the central axis of the dynamic test model rear section. A web support plate is fixed at the bottom of the dynamic support device and is connected with a model support mechanism of a high-speed wind tunnel test section. The dynamic supporting method comprises the steps of installing the dynamic test model; adjusting the posture of the dynamic test model; locking the dynamic supporting device; starting the high-speed wind tunnel; the dynamic supporting device is unlocked; carrying out a high-speed wind tunnel virtual flight test; closing the high-speed wind tunnel. The dynamic supporting method and device meet the high-speed wind tunnel test simulation requirements of closed-loop control response and control stability of a novel high-speed cruise aircraft model, and have important significance in solving the problem of unsteady aerodynamic effect and verifying and evaluating aerodynamic, motion and inertia coupling design.

Description

Technical Field

[0001] The invention belongs to the technical field of high-speed wind tunnel dynamic test, and in particular relates to a dynamic support device and method with small volume, low damping and high load-bearing pitching freedom. Background Art

[0002] The new high-speed cruise aircraft adopts the front air intake + variable configuration layout, and the longitudinal and lateral rotational inertia is much greater than the rolling direction rotational inertia. At the same time, in order to pursue the longitudinal and lateral large maneuverability, it adopts a large angle of attack (pitch angle) and uses the BTT method to turn. There are obvious unsteady aerodynamic effects during the flight, resulting in strong aerodynamic, motion and inertial coupling effects. Therefore, quantitative evaluation and accurate design of inertial coupling effects are key technical issues that must be solved in the design of new high-speed cruise aircraft.

[0003] At present, wind tunnel virtual flight test is one of the main means of designing, verifying and evaluating the coupling of aerodynamics, motion and control of high-speed aircraft. Wind tunnel virtual flight test equipment mainly includes dynamic test model, dynamic support device, variable configuration device, variable center of mass device and steering gear system. Wind tunnel virtual flight test generally adopts low damping dynamic support device and dynamic test model whose dynamic support mass characteristics match the real aircraft, and realizes attitude control simulation of aircraft model in wind tunnel through variable configuration, variable center of mass and rudder control.

[0004] The new high-speed cruise aircraft adopts the front air inlet + variable configuration layout, and the center of rotation of the dynamic support device coincides with the center of mass of the dynamic test model. This puts forward high requirements on the design of the wind tunnel dynamic test model and device of the new high-speed cruise aircraft, especially the design of the dynamic support device. First, the dynamic test model adopts the front air inlet + variable configuration layout, which leads to a small space allowed for use in the dynamic test model, a large model size, a large aerodynamic load on the model, and a high load-bearing capacity requirement for the dynamic support device; second, there is competition for the installation space of the variable configuration device, the variable center of mass device and the dynamic support device, so the volume of the dynamic support device must be as small as possible, and the dynamic test model must be flexible in movement and the damping of the dynamic support device must be small; third, the initial posture of the dynamic test model is required to be fixed during the wind tunnel test, and the dynamic support device must have the ability to automatically lock and unlock; fourth, the dynamic support device must have the ability to measure the motion parameters of the dynamic test model in real time.

[0005] Currently, there is an urgent need to develop a dynamic support device and method with small volume, low damping, high load-bearing capacity and pitch freedom. Summary of the invention

[0006] One technical problem to be solved by the present invention is to provide a dynamic support device with small volume, low damping and high load-bearing pitch freedom. Another technical problem to be solved by the present invention is to provide a dynamic support method with small volume, low damping and high load-bearing pitch freedom, so as to solve the model support problem of the pitch freedom high-speed wind tunnel virtual flight test of a new high-speed cruise aircraft with a front air inlet + variable configuration layout.

[0007] The dynamic support device with small volume, low damping and high load-bearing pitching freedom of the present invention comprises a front section of a dynamic test model and a rear section of a dynamic test model connected sequentially from front to back, a force measuring balance and a dynamic support device are fixed sequentially from front to back on the central axis of the rear section of the dynamic test model, a belly support plate is fixed on the belly of the dynamic support device, and the belly support plate is connected to the model support mechanism of the high-speed wind tunnel test section; The lower end of the belly support plate is fixed to the model support mechanism by bolts, and the rear end of the pitch axis of the dynamic support device is fixed to the upper end of the belly support plate by means of cone pin positioning and bolt locking; the force measuring balance adopts a six-component rod strain balance, and the rear end of the force measuring balance is fixedly connected to the dynamic support device; the front end of the force measuring balance and the rear section of the dynamic test model are connected by a cone surface and then tightened by bolts; the front section of the dynamic test model and the rear section of the dynamic test model are fixedly connected by screws.

[0008] Furthermore, the dynamic support device comprises a balance connection flange, a pitch adjustment mechanism, a pitch axis angular displacement measuring device and a pitch axis automatic locking mechanism; The pitch adjustment mechanism is the main structure of the dynamic support device, located on the central axis of the rear section of the dynamic test model, and is used to adjust the pitch angle of the dynamic test model; the pitch axis angular displacement measuring device is used to measure the angular displacement of the pitch motion of the dynamic test model; the pitch axis automatic locking mechanism is used to lock the pitch angle of the dynamic test model.

[0009] Furthermore, the pitch adjustment mechanism comprises a pitch axis, a pitch bearing, a pitch axis housing and a pitch bearing end cover; the pitch bearing is a low-damping precision mechanical bearing; The pitch axis housing is a semi-enclosed housing; the front end of the pitch axis housing is a closed end, the closed end is provided with an interface matching the balance connection flange, and the closed end and the balance connection flange are fixed by screws; the rear end of the pitch axis housing is an open end, and the upper and lower contacts between the open rear end of the pitch axis housing and the pitch axis realize the mechanical limit of the pitch movement; the pitch axis housing is connected to the pitch axis through a pair of pitch bearings; the two pitch bearing end covers are fixedly connected to the pitch axis housing by screws, and the pitch bearings are fixed to the pitch axis; The two pitch bearing end covers correspond to the pitch bearings on the left and right sides one by one, forming the pitch bearing end covers on the left and right sides, and the pitch bearing end covers on the left and right sides are respectively fixed to the left and right sides of the pitch shaft housing by screws distributed along the circumferential direction; The rear section of the dynamic test model performs pitch motion around the pitch axis through a force measuring balance and a pitch axis housing, thereby realizing dynamic adjustment of the pitch degree of freedom of the dynamic test model.

[0010] Furthermore, the pitch axis angular displacement measuring device adopts a rotary transformer to measure the rotational angular displacement and speed; the pitch axis angular displacement measuring device comprises a rotary transformer stator, a rotary transformer rotor, a rotary transformer bracket, a rotary transformer rotor locking nut and a rotary transformer stator locking nut; The resolver bracket is located in the central cavity of the pitch shaft. The resolver bracket is sequentially equipped with a resolver rotor and a resolver stator from the inside to the outside. The resolver stator is fixed to the pitch shaft through a resolver stator locking nut. The resolver rotor locking nut is fixedly connected to the pitch bearing end cover, and then moves synchronously with the pitch shaft housing. When the pitch axis housing rotates with the dynamic test model, the resolver rotor and the resolver stator generate the same rotation as the pitch axis housing, and the pitch axis angular displacement measuring device outputs a pitch angular displacement signal in real time.

[0011] Furthermore, the pitch axis automatic locking mechanism adopts pneumatic brake locking; the pitch axis automatic locking mechanism includes a cylinder shaft, a friction plate, a brake plate, a cylinder front cover and a cylinder rear cover; The cylinder shaft is fixedly connected to the pitch axis through a collar; the cylinder front cover and the cylinder rear cover constitute a cylinder that moves left and right along the cylinder axis, and the cylinder front cover is fixedly connected to the brake pad; the left and right sides of the brake pad are connected to the friction plate through countersunk screws; the cylinder front cover, the cylinder rear cover and the cylinder shaft are connected by cylindrical sliding seals through O-rings; a chamber is provided between the cylinder front cover and the cylinder rear cover; the chamber is connected to a high-pressure gas source through an air hole, and the pressure range of the high-pressure gas source is 1.2MPa~1.5MPa; the high-pressure gas source drives the cylinder to move left and right along the cylinder axis, thereby driving the contact and disengagement between the brake pad fixedly connected to the cylinder front cover and the pitch bearing end cover, thereby realizing automatic locking and unlocking of the pitch axis housing and the dynamic test model.

[0012] Furthermore, the pitch bearing is a 71907 type angular contact ball bearing.

[0013] Furthermore, the rotary transformer is a Tamagawa TS type rotary transformer with an angular resolution of 16 bits, and the angular displacement measurement range and accuracy meet the requirements of high-speed wind tunnel virtual flight tests.

[0014] The dynamic support method of the present invention with small volume, low damping and high load-bearing pitching freedom comprises the following steps: S10. Install the dynamic test model; The dynamic support device is fixedly connected to the force measuring balance via the balance connecting flange; The bottom connecting plate of the dynamic support device is fixedly connected to the belly support plate by means of cone pin positioning and bolt locking; The belly support plate is fixedly connected to the model support mechanism of the high-speed wind tunnel test section by bolts; The rear section of the dynamic test model is locked and connected with the force measuring balance through the front cone surface of the force measuring balance; the front section of the dynamic test model is fixedly connected with the rear section of the dynamic test model through screws; S20. Adjust the dynamic test model posture; Adjust the pitch angle of the dynamic test model so that the dynamic test model reaches the initial posture; S30. Locking dynamic support device; High-pressure gas is introduced into the chamber between the cylinder front cover and the cylinder rear cover through the air hole, and the combination of the cylinder front cover and the brake pad moves forward under the action of the high-pressure gas, and the friction plate contacts the pitch bearing end cover, and the friction force between the friction plate and the pitch bearing end cover is used to provide a locking torque to lock the dynamic support device; S40. Start the high-speed wind tunnel; Start the high-speed wind tunnel until the flow field in the high-speed wind tunnel is stable; S50. Unlock the dynamic support device; The high-pressure gas in the chamber between the cylinder front cover and the cylinder rear cover is discharged, the cylinder front cover and the brake pad assembly move backward, the friction plate is out of contact with the pitch bearing end cover, and the dynamic test model attitude is in a pitch free state; S60. Conduct high-speed wind tunnel virtual flight tests; Carry out high-speed wind tunnel virtual flight tests according to the test schedule to obtain aerodynamic and motion data of the dynamic test model; S70. Close the high-speed wind tunnel; After the high-speed wind tunnel virtual flight test is completed, the dynamic support device is locked and the high-speed wind tunnel is closed.

[0015] The dynamic support device with small volume, low damping and high load-bearing pitching freedom of the present invention has the characteristics of simple structure, small volume, high overall rigidity, etc., and can meet the high load-bearing capacity required by high-speed wind tunnel tests.

[0016] The dynamic support method of small volume, low damping and high load pitch freedom of the present invention is based on the dynamic support of mechanical bearings and the stepless locking of the friction of the cylinder-driven arc surface, and a pair of precision mechanical bearings are used to realize the miniaturized low damping and high load dynamic support; the outer ring of the precision mechanical bearing is fixedly connected to the dynamic test model through the outer frame of the dynamic support device and the high load six-component rod balance; the inner ring of the precision mechanical bearing is fixedly connected to the belly support plate of the middle bracket of the high-speed wind tunnel through the fixed pitch axis, so as to realize the low damping free movement of the dynamic test model in the pitch freedom. The air gap between the rotary transformer stator and the rotary transformer rotor in the rotary transformer is used, and no direct contact occurs, which reduces the friction resistance and reduces the interference to the dynamic test model. The rotary transformer is used to measure the angular displacement and angular velocity of the pitch freedom rotation. The rotary transformer stator is fixed on the pitch axis through a locking nut, and the rotary transformer rotor is fixed on the outer frame of the dynamic support device and rotates accordingly. The rotary transformer stator and the rotary transformer rotor generate the same rotation as the dynamic test model, and the pitch freedom angular displacement and angular velocity signals are output in real time, and the angular displacement accuracy is better than 0.05°. At the same time, a cylinder is used to drive a cylinder body with arc surfaces on both sides to press and contact the two arc surfaces on the outer frame of the dynamic support device, so as to realize automatic friction stepless locking and unlocking of the dynamic test model and ensure the initial posture of the dynamic test model before the high-speed wind tunnel test.

[0017] The dynamic support device and method of the present invention with small volume, low damping and high load-bearing pitching freedom have the following characteristics: a. The structure is compact and the volume is small. The dynamic test model can be easily installed and disassembled. The dynamic support device can be built inside the dynamic test model and does not interfere with the high-speed wind tunnel flow field, meeting the basic requirements of high-speed wind tunnel tests. The selected bearing assembly can meet the aerodynamic load characteristics during the dynamic wind tunnel test. During the test, the dynamic test model can achieve low-friction free rotation in pitch freedom and can also be automatically locked and unlocked through the locking device. b. The connection form of the balance in front is adopted, and the interface is located in the middle of the dynamic test model. During the test, the temperature in the middle of the dynamic test model rises relatively slowly, which is conducive to reducing the temperature effect of the balance during the test; c. The dynamic support device based on precision mechanical bearings is small in size and high in load-bearing capacity. The rotary transformer used is compact in structure and has high measurement accuracy.

[0018] The small-volume, low-damping, high-load pitch freedom dynamic support device and method of the present invention have the ability of small-volume, low-damping, high-load pitch freedom dynamic support, and also have the functions of automatic locking, unlocking and pitch motion parameter measurement; easy to install and disassemble; able to provide real-time feedback of the posture parameters and aerodynamic loads of the dynamic test model; and can be used for model support of high-speed wind tunnel virtual flight test of pitch freedom of new high-speed cruise aircraft with front air inlet + variable configuration layout. It meets the high-speed wind tunnel test simulation requirements of closed-loop control response and control stability of new high-speed cruise aircraft models, and is of great significance for solving the unsteady aerodynamic effect problems faced by new high-speed cruise aircraft, as well as the verification and evaluation of aerodynamic, motion and inertial coupling design. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a small-volume, low-damping, high-load pitching degree of freedom dynamic support device of the present invention; Figure 2 It is a schematic diagram of the connection structure between the force measuring balance and the dynamic support device in the small-volume, low-damping, high-load pitch freedom dynamic support device of the present invention; Figure 3 It is a schematic diagram of the adjustment mechanism in the small-volume, low-damping, high-load pitch freedom dynamic support device of the present invention; Figure 4 It is a schematic diagram of an angular displacement measuring device in a small-volume, low-damping, high-load pitch freedom dynamic support device of the present invention; Figure 5 It is a schematic diagram of the locking mechanism in the small-volume, low-damping, high-load pitch freedom dynamic support device of the present invention; Figure 6 It is an exploded view of the small-volume, low-damping, high-load-bearing pitch freedom dynamic support device of the present invention.

[0020] In the figure, 1. model support mechanism; 2. belly support plate; 3. dynamic support device; 4. force balance; 5. rear section of dynamic test model; 6. front section of dynamic test model; 7. balance connecting flange; 8. pitch adjustment mechanism; 9. pitch axis angular displacement measuring device; 10. pitch axis automatic locking mechanism; 11. pitch axis housing; 12. pitch bearing; 13. pitch axis; 14. pitch bearing end cover; 15. resolver stator; 16. resolver rotor; 17. resolver bracket; 18. resolver rotor locking nut; 19. resolver stator locking nut; 20. cylinder shaft; 21. friction plate; 22. brake pad; 23. cylinder front cover; 24. cylinder rear cover. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0022] like Figure 1As shown, the dynamic support device with small volume, low damping and high load-bearing pitching freedom of the present invention comprises a dynamic test model front section 6 and a dynamic test model rear section 5 connected sequentially from front to back, a force measuring balance 4 and a dynamic support device 3 are fixed sequentially from front to back on the central axis of the dynamic test model rear section 5, a belly support plate 2 is fixed on the belly of the dynamic support device 3, and the belly support plate 2 is connected to the model support mechanism 1 of the high-speed wind tunnel test section; The lower end of the abdominal support plate 2 is fixed to the model support mechanism 1 by bolts, and the rear end of the pitch axis 13 of the dynamic support device 3 is fixed to the upper end of the abdominal support plate 2 by means of cone pin positioning and bolt locking; the force measuring balance 4 adopts a six-component rod strain balance, and the rear end of the force measuring balance 4 is fixedly connected to the dynamic support device 3; the front end of the force measuring balance 4 and the rear section 5 of the dynamic test model are connected by a cone surface and then tightened by bolts; the front section 6 of the dynamic test model and the rear section 5 of the dynamic test model are fixedly connected by screws.

[0023] Furthermore, if Figure 2 As shown, the dynamic support device 3 includes a balance connecting flange 7, a pitch adjustment mechanism 8, a pitch axis angular displacement measuring device 9 and a pitch axis automatic locking mechanism 10; The pitch adjustment mechanism 8 is the main structure of the dynamic support device 3, located on the central axis of the rear section 5 of the dynamic test model, and is used to adjust the pitch angle of the dynamic test model; the pitch axis angular displacement measuring device 9 is used to measure the angular displacement of the pitch motion of the dynamic test model; the pitch axis automatic locking mechanism 10 is used to lock the pitch angle of the dynamic test model.

[0024] Furthermore, if Figure 3 As shown, the pitch adjustment mechanism 8 includes a pitch axis 13, a pitch bearing 12, a pitch axis housing 11 and a pitch bearing end cover 14; the pitch bearing 12 is a low-damping precision mechanical bearing; The pitch axis housing 11 is a semi-enclosed housing; the front end of the pitch axis housing 11 is a closed end, the closed end is provided with an interface matching the balance connection flange 7, and the closed end and the balance connection flange 7 are fixed by screws; the rear end of the pitch axis housing 11 is an open end, and the upper and lower contacts between the open rear end of the pitch axis housing 11 and the pitch axis 13 realize the mechanical limit of the pitch movement; the pitch axis housing 11 is connected to the pitch axis 13 through a pair of pitch bearings 12; two pitch bearing end covers 14 are fixedly connected to the pitch axis housing 11 by screws, and the pitch bearings 12 are fixed to the pitch axis 13; The two pitch bearing end covers 14 correspond to the pitch bearings 12 on the left and right sides one by one, forming the pitch bearing end covers 14 on the left and right sides. The pitch bearing end covers 14 on the left and right sides are respectively fixed to the left and right sides of the pitch shaft housing 11 by screws distributed along the circumferential direction. The rear section 5 of the dynamic test model performs pitch motion around the pitch axis 13 through the force measuring balance 4 and the pitch axis housing 11, thereby realizing dynamic adjustment of the pitch freedom of the dynamic test model.

[0025] Furthermore, if Figure 4 As shown, the pitch axis angular displacement measuring device 9 adopts a rotary transformer to measure the rotational angular displacement and speed; the pitch axis angular displacement measuring device 9 includes a rotary transformer stator 15, a rotary transformer rotor 16, a rotary transformer bracket 17, a rotary transformer rotor locking nut 18 and a rotary transformer stator locking nut 19; The resolver bracket 17 is located in the central cavity of the pitch shaft 13. The resolver bracket 17 sequentially mounts the resolver rotor 16 and the resolver stator 15 from the inside to the outside. The resolver stator 15 is fixed to the pitch shaft 13 by a resolver stator locking nut 19. The resolver rotor locking nut 18 is fixedly connected to the pitch bearing end cover 14, and then moves synchronously with the pitch shaft housing 11. When the pitch axis housing 11 rotates with the dynamic test model, the resolver rotor 16 and the resolver stator 15 generate the same rotation as the pitch axis housing 11, and the pitch axis angular displacement measuring device 9 outputs a pitch angular displacement signal in real time.

[0026] Furthermore, if Figure 5 As shown, the pitch axis automatic locking mechanism 10 adopts pneumatic brake locking; the pitch axis automatic locking mechanism 10 includes a cylinder shaft 20, a friction plate 21, a brake plate 22, a cylinder front cover 23 and a cylinder rear cover 24; The cylinder shaft 20 is fixedly connected to the pitch shaft 13 through a collar; the cylinder front cover 23 and the cylinder rear cover 24 constitute a cylinder that moves left and right along the cylinder shaft 20, and the cylinder front cover 23 is fixedly connected to the brake pad 22; the left and right sides of the brake pad 22 are connected to the friction plate 21 through countersunk screws; the cylinder front cover 23, the cylinder rear cover 24 and the cylinder shaft 20 are connected by cylindrical sliding sealing through O-rings; a chamber is provided between the cylinder front cover 23 and the cylinder rear cover 24; the chamber is connected to a high-pressure gas source through an air hole, and the pressure range of the high-pressure gas source is 1.2MPa~1.5MPa; the high-pressure gas source drives the cylinder to move left and right along the cylinder shaft 20, and then drives the brake pad 22 fixedly connected to the cylinder front cover 23 to contact and disengage with the pitch bearing end cover 14, thereby realizing automatic locking and unlocking of the pitch shaft housing 11 and the dynamic test model.

[0027] Furthermore, the pitch bearing 12 is a 71907 type angular contact ball bearing.

[0028] Furthermore, the rotary transformer is a Tamagawa TS type rotary transformer with an angular resolution of 16 bits, and the angular displacement measurement range and accuracy meet the requirements of high-speed wind tunnel virtual flight tests.

[0029] The dynamic support method of the present invention with small volume, low damping and high load-bearing pitching freedom comprises the following steps: S10. Install the dynamic test model; The dynamic support device 3 is fixedly connected to the force measuring balance 4 via the balance connecting flange 7; The bottom connecting plate of the dynamic support device 3 is fixedly connected to the belly support plate 2 by means of cone pin positioning and bolt locking; The belly support plate 2 is fixedly connected to the model support mechanism 1 of the high-speed wind tunnel test section by bolts; The rear section 5 of the dynamic test model is locked and connected with the force measuring balance 4 through the front cone surface of the force measuring balance 4; the front section 6 of the dynamic test model is fixedly connected with the rear section 5 of the dynamic test model through screws; S20. Adjust the dynamic test model posture; Adjust the pitch angle of the dynamic test model so that the dynamic test model reaches the initial posture; S30. Locking dynamic support device 3; High-pressure gas is introduced into the chamber between the cylinder front cover 23 and the cylinder rear cover 24 through the air hole. The combination of the cylinder front cover 23 and the brake pad 22 moves forward under the action of the high-pressure gas, and the friction plate 21 contacts the pitch bearing end cover 14. The friction force between the friction plate 21 and the pitch bearing end cover 14 provides a locking torque to lock the dynamic support device 3. S40. Start the high-speed wind tunnel; Start the high-speed wind tunnel until the flow field in the high-speed wind tunnel is stable; S50. Unlock the dynamic support device 3; The high-pressure gas in the chamber between the cylinder front cover 23 and the cylinder rear cover 24 is discharged, the assembly of the cylinder front cover 23 and the brake pad 22 moves backward, the friction plate 21 is out of contact with the pitch bearing end cover 14, and the dynamic test model is in a pitch free state; S60. Conduct high-speed wind tunnel virtual flight tests; Carry out high-speed wind tunnel virtual flight tests according to the test schedule to obtain aerodynamic and motion data of the dynamic test model; S70. Close the high-speed wind tunnel; After the high-speed wind tunnel virtual flight test is completed, the dynamic support device 3 is locked and the high-speed wind tunnel is closed.

[0030] Embodiment: The small volume, low damping, high load bearing pitch freedom dynamic support device of this embodiment is shown in Figure 6 .

[0031] 1. Relevant technical indicators and requirements: 1. Able to achieve automatic locking and unlocking; 2. Load bearing: axial FA ≥ 1000N, normal FN ≥ 2000N, lateral FZ ≥ 500N, the center distance between the two pitch bearings 12 is about 41mm, and the maximum moment that can be borne is 7800×0.041=320Nm; 3. Pitch angle adjustment range: -8°~+8°.

[0032] (II) Selection of main components: 1. Bearing assembly: The bearing assembly must withstand three loads, namely axial load, normal load and lateral load, which can be equivalent to the combined load of radial load and axial load. For the dynamic support device 3, the pitch adjustment mechanism 8 is not used frequently and the running time is short, so the life of the pitch bearing 12 is not a major factor; the size of the friction torque plays a decisive role in the selection of the pitch bearing 12. According to the bearing performance parameters provided by the bearing manufacturer, the dynamic friction torque of the pitch bearing 12 under the above-mentioned combined load is estimated. The friction torque of a set of pitch bearings 12 can be calculated by the following formula: ; in, μ is the bearing friction coefficient, d is the bearing inner ring diameter, F is the external load; The pitch bearing 12 of this embodiment has more stringent technical requirements for the friction torque, because the friction torque must withstand a radial load of 1.12kN (generated by the axial load and the lateral load) and a relatively large axial load of 0.5kN (generated by the model's own weight and the normal load). Comprehensively analyzing the load characteristics of various types of bearings, the friction torque index of the dynamic support device 3, and the bearing performance data provided by the manufacturer, the pitch bearing 12 uses a 71907 angular contact ball bearing to form a bearing pair. The center distance between the two pitch bearings 12 is about 41mm, and the maximum torque that can be borne is: 7800×0.041=320Nm; 2. Locking mechanism: The dynamic support device 3 adopts an elastic body pneumatic locking scheme. When high-pressure gas is introduced into the chamber between the cylinder front cover 23 and the cylinder rear cover 24, the combination of the cylinder front cover 23 and the friction plate 21 moves forward under the action of the pneumatic force, and the friction plate 21 contacts the pitch bearing end cover 14. The friction between the friction plate 21 and the pitch bearing end cover 14 is used to provide a braking or locking torque; The chamber area is: ; in, d 1 is the diameter of the cylinder shaft 20, d 2 is the diameter of the chamber. Friction arm L =150mm, given locking torque M=200Nm, take the friction coefficient f =0.15, the required gas pressure can be estimated as: ; Then, under the action of the air supply pressure of 2.57 MPa, the pitch axis automatic locking mechanism 10 can provide a locking torque of 200 Nm; 3. Rotary transformer and six-component rod-type strain balance: Rotary transformer is mainly used for real-time feedback of dynamic characteristics related to the motion of dynamic test models, and six-component rod-type strain balance is mainly used for real-time feedback of aerodynamic loads of dynamic test models. The rotary transformer stator 15 and the rotary transformer rotor 16 in the rotary transformer have an air gap, and no direct contact occurs, which reduces the friction resistance and reduces the interference of the friction resistance generated by the angular displacement measurement device on the dynamic test model; when the rotary transformer rotor 16 rotates, the output voltage of the two-phase output coil winding changes with the rotary transformer rotor 16, and the magnetic permeability of the rotary transformer changes with the rotation angle in accordance with the sinusoidal distribution. This embodiment uses the Tamagawa TS type rotary transformer. The angular displacement resolution of the Tamagawa TS type rotary transformer is 16 bits, which can measure the rotational angular displacement and speed, and the measurement angular displacement range is unlimited. The angular displacement measurement range and accuracy meet the requirements of high-speed wind tunnel virtual flight tests.

[0033] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and implementation modes. For those familiar with the art, all features disclosed in the present invention, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any way without departing from the principles of the present invention. The present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A dynamic support device with small volume, low damping and high load-bearing pitch freedom, characterized in that: The small-volume, low-damping, high-load pitching freedom dynamic support device comprises a dynamic test model front section (6) and a dynamic test model rear section (5) connected in sequence from front to back; a force measuring balance (4) and a dynamic support device (3) are fixed in sequence from front to back on the central axis of the dynamic test model rear section (5); a belly support plate (2) is fixed to the belly of the dynamic support device (3); and the belly support plate (2) is connected to a model support mechanism (1) of a high-speed wind tunnel test section; The lower end of the belly support plate (2) is fixed to the model support mechanism (1) by bolts, and the rear end of the pitch axis (13) of the dynamic support device (3) is fixed to the upper end of the belly support plate (2) by means of cone pin positioning and bolt locking. The force measuring balance (4) adopts a six-component rod strain balance, and the rear end of the force measuring balance (4) is fixedly connected to the dynamic support device (3). The front end of the force measuring balance (4) and the rear section (5) of the dynamic test model are connected by a cone surface and then tightened by bolts. The front section (6) of the dynamic test model and the rear section (5) of the dynamic test model are fixedly connected by screws.

2. The dynamic support device with small volume, low damping and high load-bearing pitching freedom according to claim 1 is characterized in that: The dynamic support device (3) comprises a balance connecting flange (7), a pitch adjustment mechanism (8), a pitch axis angular displacement measuring device (9) and a pitch axis automatic locking mechanism (10); The pitch adjustment mechanism (8) is the main structure of the dynamic support device (3), is located on the central axis of the rear section (5) of the dynamic test model, and is used to adjust the pitch angle of the dynamic test model; the pitch axis angular displacement measuring device (9) is used to measure the angular displacement of the pitch motion of the dynamic test model; and the pitch axis automatic locking mechanism (10) is used to lock the pitch angle of the dynamic test model.

3. The dynamic support device with small volume, low damping and high load-bearing pitching freedom according to claim 2 is characterized in that: The pitch adjustment mechanism (8) comprises a pitch axis (13), a pitch bearing (12), a pitch axis housing (11) and a pitch bearing end cover (14); the pitch bearing (12) is a low-damping precision mechanical bearing; The pitch axis housing (11) is a semi-enclosed housing; the front end of the pitch axis housing (11) is a closed end, the closed end is provided with an interface matching the balance connection flange (7), and the closed end and the balance connection flange (7) are fixed by screws; the rear end of the pitch axis housing (11) is an open end, and the upper and lower contacts between the open rear end of the pitch axis housing (11) and the pitch axis (13) realize the mechanical limit of the pitch movement; the pitch axis housing (11) is connected to the pitch axis (13) via a pair of pitch bearings (12); two pitch bearing end covers (14) are fixedly connected to the pitch axis housing (11) by screws, and the pitch bearings (12) are fixed to the pitch axis (13); Two pitch bearing end covers (14) correspond to the pitch bearings (12) on the left and right sides one by one, forming pitch bearing end covers (14) on the left and right sides, and the pitch bearing end covers (14) on the left and right sides are respectively fixed to the left and right sides of the pitch shaft housing (11) by screws distributed along the circumferential direction; The rear section (5) of the dynamic test model performs a pitching motion around the pitch axis (13) through the force measuring balance (4) and the pitch axis housing (11), thereby achieving dynamic adjustment of the pitch degree of freedom of the dynamic test model.

4. The dynamic support device with small volume, low damping and high load-bearing pitch freedom according to claim 3 is characterized in that: The pitch axis angular displacement measuring device (9) uses a rotary transformer to measure the rotational angular displacement and speed; the pitch axis angular displacement measuring device (9) comprises a rotary transformer stator (15), a rotary transformer rotor (16), a rotary transformer bracket (17), a rotary transformer rotor locking nut (18) and a rotary transformer stator locking nut (19); The resolver bracket (17) is located in the central cavity of the pitch shaft (13), and the resolver bracket (17) is sequentially mounted with a resolver rotor (16) and a resolver stator (15) from the inside to the outside. The resolver stator (15) is fixed to the pitch shaft (13) via a resolver stator locking nut (19), and the resolver rotor locking nut (18) is fixedly connected to the pitch bearing end cover (14), thereby moving synchronously with the pitch shaft housing (11); When the pitch axis housing (11) rotates along with the dynamic test model, the same rotation as the pitch axis housing (11) is generated between the resolver rotor (16) and the resolver stator (15), and the pitch axis angular displacement measuring device (9) outputs a pitch angular displacement signal in real time.

5. The dynamic support device with small volume, low damping and high load-bearing pitching freedom according to claim 4 is characterized in that: The pitch axis automatic locking mechanism (10) adopts pneumatic brake locking; the pitch axis automatic locking mechanism (10) comprises a cylinder shaft (20), a friction plate (21), a brake plate (22), a cylinder front cover (23) and a cylinder rear cover (24); The cylinder shaft (20) is fixedly connected to the pitch shaft (13) via a collar; the cylinder front cover (23) and the cylinder rear cover (24) form a cylinder that moves left and right along the cylinder shaft (20); the cylinder front cover (23) is fixedly connected to the brake pad (22); the left and right sides of the brake pad (22) are connected to the friction plate (21) via countersunk screws; the cylinder front cover (23), the cylinder rear cover (24) and the cylinder shaft (20) are connected via an O-ring using a cylindrical sliding seal; A chamber is provided between the cylinder front cover (23) and the cylinder rear cover (24); the chamber is connected to a high-pressure gas source through an air hole, and the pressure range of the high-pressure gas source is 1.2MPa-1.5MPa; the high-pressure gas source drives the cylinder to move left and right along the cylinder axis (20), thereby driving the contact and separation between the brake pad (22) fixedly connected to the cylinder front cover (23) and the pitch bearing end cover (14), thereby realizing automatic locking and unlocking of the pitch axis housing (11) and the dynamic test model.

6. The dynamic support device with small volume, low damping and high load capacity and pitching freedom according to claim 3 is characterized in that: The pitch bearing (12) is a 71907 type angular contact ball bearing.

7. The dynamic support device with small volume, low damping and high load capacity and pitching freedom according to claim 4 is characterized in that: The rotary transformer is a Tamagawa TS type rotary transformer with an angular resolution of 16 bits. The angular displacement measurement range and accuracy meet the requirements of high-speed wind tunnel virtual flight tests.

8. A dynamic support method for small volume, low damping, high load and pitching freedom, which is used for a dynamic support device for small volume, low damping, high load and pitching freedom as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S10. Install the dynamic test model; The dynamic support device (3) is fixedly connected to the force measuring balance (4) via a balance connecting flange (7); The bottom connecting plate of the dynamic support device (3) is fixedly connected to the belly support plate (2) by means of cone pin positioning and bolt locking; The belly support plate (2) is fixedly connected to the model support structure (1) of the high-speed wind tunnel test section by bolts; The rear section (5) of the dynamic test model is locked and connected to the force measuring balance (4) via the front cone surface of the force measuring balance (4); the front section (6) of the dynamic test model is fixedly connected to the rear section (5) of the dynamic test model via screws; S20. Adjust the dynamic test model posture; Adjust the pitch angle of the dynamic test model so that the dynamic test model reaches the initial posture; S30. Locking dynamic support device (3); High-pressure gas is introduced into the chamber between the cylinder front cover (23) and the cylinder rear cover (24) through the air hole, and the assembly of the cylinder front cover (23) and the brake pad (22) moves forward under the action of the high-pressure gas, and the friction plate (21) contacts the pitch bearing end cover (14), and the friction force between the friction plate (21) and the pitch bearing end cover (14) is used to provide a locking torque, thereby locking the dynamic support device (3); S40. Start the high-speed wind tunnel; Start the high-speed wind tunnel until the flow field in the high-speed wind tunnel is stable; S50. Unlocking the dynamic support device (3); The high-pressure gas in the chamber between the cylinder front cover (23) and the cylinder rear cover (24) is discharged, the cylinder front cover (23) and the brake pad (22) assembly moves backward, the friction plate (21) is out of contact with the pitch bearing end cover (14), and the dynamic test model posture is in a pitch free state; S60. Conduct high-speed wind tunnel virtual flight tests; Carry out high-speed wind tunnel virtual flight tests according to the test schedule to obtain aerodynamic and motion data of the dynamic test model; S70. Close the high-speed wind tunnel; After the high-speed wind tunnel virtual flight test is completed, the dynamic support device (3) is locked and the high-speed wind tunnel is closed.

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