A multifunctional loading head for low-speed wind tunnel balance

Abstract

A multifunctional loading head for a low-speed wind tunnel balance belongs to the field of wind tunnel balance calibration, and is particularly related to static calibration compatible with large external balances and box balances; it solves the problem that the existing loading head cannot meet the calibration requirements of new large-size external balances, cannot take into account the static calibration of box balances, cannot achieve multiple uses, has low equipment utilization rate, and seriously wastes resources; the loading head includes: a loading head body, 4 detachable loading head arms, 2 laser positioning target seats, and 14 elastic hinge connections; an elastic hinge connection is provided on the vertically upward side of the end of the detachable loading head arm away from the loading head body; 4 elastic hinge connections are symmetrically provided on the left and right sides of the front and rear ends of the loading head body near the detachable loading head arm. The multifunctional loading head for a low-speed wind tunnel balance is suitable for calibration of wind tunnel balances.

Description

Technical Field

[0001] The invention relates to the field of wind tunnel balance calibration, in particular to static calibration compatible with large external balances and box balances. Background Art

[0002] A wind tunnel balance is a device used to measure aerodynamic forces and moments on a model during a wind tunnel test.

[0003] Before measuring the aerodynamic load of the wind tunnel test model, it is necessary to perform static calibration of the balance on the ground to obtain the corresponding relationship between the balance signal output and the load. It can be said that high-precision balance calibration is the prerequisite for obtaining high-precision aerodynamic data. Balance calibration is divided into three parts: reset system, loading system, and measurement system. The loading system mainly applies load to the calibrated balance through the loading head, so the loading head is the key equipment in the wind tunnel balance loading system.

[0004] In recent years, with the continuous construction of large wind tunnels, the size of wind tunnel test sections has increased significantly compared with the past, which in turn requires the size of wind tunnel balances to continue to increase.

[0005] The existing wind tunnel balance calibration equipment can no longer meet the calibration needs of the new large-sized external balance; at the same time, from the perspective of avoiding waste of resources, the calibration equipment designed solely for the new large-sized external balance cannot take into account the static calibration of the box balance, and cannot achieve multiple uses of one item. The equipment utilization rate is low and resources are seriously wasted. Summary of the invention

[0006] The present invention proposes a multifunctional loading head for a low-speed wind tunnel balance, which solves the problems that the existing loading head cannot meet the calibration requirements of a new large-size external balance, cannot take into account the static calibration of a box balance, cannot achieve multiple uses, has a low equipment utilization rate, and seriously wastes resources.

[0007] The present invention also proposes a multifunctional loading head for a low-speed wind tunnel balance, and its technical solution is as follows:

[0008] The loading head comprises: a loading head body, four detachable loading head arms, two laser positioning target seats and 14 elastic hinge connections;

[0009] Two detachable loading head support arms are respectively arranged at the front and rear ends of the loading head body, and the two detachable loading head support arms are symmetrically arranged along the left and right sides of one end of the loading head body; the vertical axes of the four detachable loading head support arms are parallel;

[0010] A laser positioning target seat is respectively provided on the front part of both ends of the loading head body;

[0011] Two protruding brackets are symmetrically arranged on the left and right sides of the middle section of the loading head body;

[0012] An elastic hinge connection is provided on the vertically upward side of one end of the detachable loading head support arm away from the loading head body;

[0013] Four elastic hinge connections are symmetrically arranged on the left and right sides of the front and rear ends of the loading head body near the detachable loading head support arm;

[0014] Two elastic hinge connections are symmetrically arranged on the front and rear sides of the protruding bracket;

[0015] The vertical downward side of the protruding bracket is provided with an elastic hinge connection.

[0016] Furthermore, a preferred embodiment is provided, wherein each elastic hinge connection is connected to an elastic hinge; and each elastic hinge is connected to a loading steel cable via a steel cable hook.

[0017] Furthermore, a preferred embodiment is provided, wherein the elastic hinge is a cross elastic hinge.

[0018] Furthermore, a preferred embodiment is provided, wherein a dovetail block seat is provided at the top of the elastic hinge; a dovetail connecting portion is provided at the bottom of the steel cable hook; the steel cable hook is fixedly connected to the elastic hinge by an anti-slip screw, and the dovetail block seat is connected to the dovetail connecting portion.

[0019] Further, a preferred embodiment is provided, wherein the elastic hinge further comprises a connecting base and a main base;

[0020] The bottom of the main base is fixedly connected with a connecting base; the connecting base is connected to the elastic hinge connection through a locking screw;

[0021] The main base is provided with cross-shaped spring pieces;

[0022] A dovetail block seat is arranged on the top of the main base.

[0023] Further, a preferred embodiment is provided, wherein the loading steel cable and the steel cable hook are connected by a circular steel cable connection method or a linear steel cable connection method;

[0024] The annular steel cable connection method is suitable for loading loads of 3 tons to 6 tons;

[0025] The straight steel cable connection method is suitable for loading loads below 3 tons.

[0026] Further, a preferred embodiment is provided, wherein the annular steel cable is connected in the following manner:

[0027] The steel cable hook is provided with a first hanging ring; the root of the loading steel cable passes through the first hanging ring to form a second hanging ring, thereby realizing the connection between the root of the loading steel cable and the steel cable hook.

[0028] Further, a preferred embodiment is provided, wherein the straight steel cable is connected in the following manner:

[0029] The steel cable hook is provided with a center hole; the root of the loading steel cable is provided with a threaded connecting rod; the threaded connecting rod passes through the center hole and is connected to the locking nut to achieve a fixed connection between the root of the loading steel cable and the steel cable hook.

[0030] Further, a preferred embodiment is provided, a hollow chamber is provided at the central position inside the loading head body; the hollow chamber is used to place a box balance;

[0031] The top surface of the hollow chamber is provided with a cassette balance adapter; the cassette balance adapter is used for fixed connection with the cassette balance.

[0032] Further, a preferred embodiment is provided, wherein the cassette balance adapter comprises an upper surface and a boss located at the bottom of the upper surface;

[0033] The upper surface is provided with a threaded hole, and the threaded hole is used to connect with the inner hole of the loading head body, so that the cassette balance adapter is fixedly connected to the top surface of the hollow chamber;

[0034] The boss is provided with an internal through hole, and the internal through hole is used to connect with a box balance;

[0035] The boss is used as a positioning stop connected to a cassette balance.

[0036] The present invention has the following beneficial effects:

[0037] 1. The multifunctional loading head of a low-speed wind tunnel balance described in the present invention realizes the static loading requirements of a large external balance. The loading head has large overall rigidity and is easy to install. It fully considers the system errors that may occur during the loading process and improves the calibration precision and accuracy of the balance. At the same time, it takes into account the calibration requirements of the box balance, improves the utilization rate of the loading head, and plays a role in reducing costs and increasing efficiency.

[0038] 2. The multifunctional loading head of a low-speed wind tunnel balance described in the present invention adopts a cross elastic hinge (i.e., elastic hinge 4) at each loading point to reduce the interference of system errors on the loading accuracy of the force source.

[0039] 3. The multifunctional loading head for a low-speed wind tunnel balance described in the present invention enables the box-type balance and the external balance to use the same loading point during calibration through the structure of the loading head, that is, the loading head is compatible with the calibration of the box-type balance and the external balance, which improves the versatility of the equipment and reduces the time waste caused by replacing parts.

[0040] The multifunctional loading head of a low-speed wind tunnel balance described in the present invention is suitable for calibrating a wind tunnel balance. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 A front oblique view of a multifunctional loading head of a low-speed wind tunnel balance in one embodiment of the present invention;

[0043] Figure 2 It is an oblique view of the bottom surface of a multifunctional loading head of a low-speed wind tunnel balance in one embodiment of the present invention;

[0044] Figure 3 It is a structural schematic diagram of a multifunctional loading head of a low-speed wind tunnel balance connected to an external balance in one embodiment of the present invention;

[0045] Figure 4 A schematic diagram of a loading point of a multifunctional loading head of a low-speed wind tunnel balance in one embodiment of the present invention;

[0046] Figure 5 This is a schematic structural diagram of an elastic hinge in one embodiment of the present invention;

[0047] Figure 6 A schematic diagram of a connection method of a ring-shaped steel cable in one embodiment of the present invention;

[0048] Figure 7 A schematic diagram of a straight steel cable connection method in one embodiment of the present invention;

[0049] Figure 8 It is a structural schematic diagram of a multifunctional loading head of a low-speed wind tunnel balance connected to a cassette balance in one embodiment of the present invention;

[0050] Fig. 9Schematic diagram of a cassette balance adapter in one embodiment of the present invention; wherein (a) is a schematic diagram of the outer surface of the cassette balance adapter; (b) is a schematic diagram of the boss of the cassette balance adapter;

[0051] Reference numerals:

[0052] 1. Loading head body; 2. Separable loading head support arm; 3. Laser positioning target seat; 4. Elastic hinge; 40. Elastic hinge connection; 41. Dovetail block seat; 411. Anti-slip screw; 42. Main base; 423. Cross spring; 43. Connecting base; 431. Locking screw; 5. Cable hook; 51. Dovetail connection; 501. First hanging ring; 502. Locking nut; 601. Second hanging ring; 602. Threaded connecting rod; 6. Loading cable; 7. Protruding bracket; 8. Hollow chamber; 81. Box balance adapter; 811. Upper surface; 812. Boss; 813. Internal through hole; 666. Box balance; 999. External balance. DETAILED DESCRIPTION

[0053] In order to make the technical solutions and advantages of the present invention more clearly described, the specific implementation methods of the present invention will be further described in detail and completely in conjunction with the accompanying drawings. The various implementation methods described below are only part of the preferred solutions of the present invention, rather than all implementation methods; the various implementation methods described below are intended to explain the present invention and cannot be understood as limitations on the present invention; the reasonable combination of technical features defined in the various implementation methods of the present invention, and all other implementation methods obtained by ordinary technicians in the field without creative work based on the implementation methods of the present invention, are within the scope of protection of the present invention.

[0054] Implementation Method 1: Combination Figures 1 to 9 This embodiment describes a multifunctional loading head for a low-speed wind tunnel balance. The specific implementation contents are as follows:

[0055] A multifunctional loading head for a low-speed wind tunnel balance, the loading head comprising: a loading head body 1, four detachable loading head arms 2, two laser positioning target seats 3 and 14 elastic hinge connections 40;

[0056] Two detachable loading head support arms 2 are respectively arranged at the front and rear ends of the loading head body 1, and the two detachable loading head support arms 2 are symmetrically arranged along the left and right sides of one end of the loading head body 1; the vertical axes of the four detachable loading head support arms 2 are parallel;

[0057] A laser positioning target seat 3 is respectively provided on the front part of both ends of the loading head body 1;

[0058] Two protruding brackets 7 are symmetrically arranged on the left and right sides of the middle section of the loading head body 1;

[0059] An elastic hinge connection 40 is provided on the vertically upward side of the end of the detachable loading head support arm 2 away from the loading head body 1;

[0060] Four elastic hinge connections 40 are symmetrically arranged on the left and right sides of the front and rear ends of the loading head body 1 near the detachable loading head support arm 2;

[0061] Two elastic hinge connections 40 are symmetrically arranged on the front and rear sides of the protruding bracket 7;

[0062] The vertically downward side of the protruding bracket 7 is provided with an elastic hinge connection 40 .

[0063] In this embodiment, the loading head body 1 is approximately a rectangular parallelepiped structure, and the loading head body 1 lies flat on an external balance.

[0064] The front side of the loading head body 1 is the side of the loading head body 1 that faces vertically upward.

[0065] The surface of the loading head body 1 that faces vertically downward is the bottom surface of the loading head body 1 .

[0066] The two end faces of the loading head body 1 in the length direction are the front end face and the rear end face of the loading head body 1 .

[0067] In this embodiment, the front and rear surfaces of the protruding bracket 7 refer to the front and rear surfaces along the length direction of the loading head body 1. The front of the protruding bracket 7 faces the same direction as the front end surface of the loading head body 1; the rear of the protruding bracket 7 faces the same direction as the rear end surface of the loading head body 1.

[0068] In this embodiment, an external balance connecting plate 11 is provided on the bottom surface of the loading head body 1, and screw holes are provided on the external balance connecting plate 11; the loading head body 1 is connected to the (large) external balance 999 through the screw holes to realize static calibration of the large external balance.

[0069] In this embodiment, the two laser positioning target seats 3 on the loading head body 1 are used to install the target ball of the laser tracker to achieve initial high-precision positioning installation of the loading head, and can also be used for position remeasurement during the loading process.

[0070] Implementation Method 2: Combination Figures 1 to 9 This embodiment is described. This embodiment is a further limitation of the multifunctional loading head of a low-speed wind tunnel balance described in the first embodiment. The specific implementation contents are as follows:

[0071] Each elastic hinge connection 40 is connected to an elastic hinge 4 ; each elastic hinge 4 is connected to a loading steel cable 6 via a steel cable hook 5 .

[0072] In this embodiment, the detachable loading head support arm 2 is provided with a wire hole for passing the loading steel cable 6. Specifically, the four loading steel cables 6 connected to the front and rear surfaces of the two protruding brackets 7 extend outward through the corresponding wire holes.

[0073] In this embodiment, the loading head has 14 loading points, and each elastic hinge connection 40 corresponds to a loading point.

[0074] In this embodiment, the tensioning direction of each loading cable 6 corresponds to the direction of a loading point.

[0075] In this embodiment, if Figure 1 and 2 As shown, the tensioning direction or stretching direction of each loading cable 6 is:

[0076] The tensioning direction of the four loading cables 6 connected to the vertically upward side of the end of the four detachable loading head arms 2 away from the loading head body 1 is vertically upward;

[0077] The tensioning direction of the two loading steel cables 6 connected to the positions of the detachable loading head support arm 2 on the left side of the front and rear ends of the loading head body 1 is horizontally toward the left; the tensioning direction of the two loading steel cables 6 connected to the positions of the detachable loading head support arm 2 on the right side of the front and rear ends of the loading head body 1 is horizontally toward the right;

[0078] The tensioning direction of the two loading cables 6 connected to the front of the two protruding brackets 7 is horizontally forward; the tensioning direction of the two loading cables 6 connected to the rear of the two protruding brackets 7 is horizontally backward;

[0079] The tensioning direction of the two loading cables 6 connected to the vertically downward surfaces of the two protruding brackets 7 is vertically downward.

[0080] In this embodiment, if Figure 3 As shown, the setting of the 14 loading points has the following advantages:

[0081] Since the calibration load of large external balance is large, 2-point or 3-point loading in the lift direction is not enough to meet the use requirements. Therefore, 4 loading points are used to load lift, pitch moment and roll moment, which is easier to achieve moment decomposition and helps to reduce the deformation of each loading arm, improve the overall stiffness of the loading head, and improve the static calibration accuracy of the balance.

[0082] Two loading points are used in the negative lift direction to balance the effect of positive lift when loading moment;

[0083] Similarly, four loading points are used in the resistance and side force directions to realize the loading of resistance, side force and yaw moment.

[0084] Implementation Method 3: Combination Figures 1 to 9 This embodiment is described. This embodiment is a further limitation of the multifunctional loading head of a low-speed wind tunnel balance described in the second embodiment. The specific implementation contents are as follows:

[0085] The elastic hinge 4 is a cross elastic hinge.

[0086] In this embodiment, the system error caused by the equipment installation and measurement errors is that each loading point uses a cross elastic hinge (ie, elastic hinge 4) to reduce the interference of the system error on the loading accuracy of the force source.

[0087] Implementation Method 4: Combination Figures 1 to 9 This embodiment is described. This embodiment is a further limitation of the multifunctional loading head of a low-speed wind tunnel balance described in the second embodiment. The specific implementation contents are as follows:

[0088] A dovetail block seat 41 is provided at the top of the elastic hinge 4; a dovetail connecting portion 51 is provided at the bottom of the wire rope hook 5; the wire rope hook 5 is fixedly connected to the elastic hinge 4 by an anti-slip screw 411, and the dovetail block seat 41 is connected to the dovetail connecting portion 51.

[0089] In this embodiment, in order to prevent the cable hook 5 and the elastic hinge 4 from being displaced and falling off during use, an anti-falling screw 411 is used to connect the cable hook 5 and the elastic hinge 4 together to improve the safety of equipment use.

[0090] In this embodiment, the connection between the dovetail block seat 41 and the dovetail connecting portion 51 can prevent the wire rope hook 5 from rotating around the anti-slip screw 411, thereby further improving the safety of the equipment.

[0091] Implementation Method 5: Combination Figures 1 to 9 This embodiment is described. This embodiment is a further limitation of the multifunctional loading head of a low-speed wind tunnel balance described in Embodiment 4. The specific implementation contents are as follows:

[0092] The elastic hinge 4 also includes a connecting base 43 and a main base 42;

[0093] The bottom of the main base 42 is fixedly connected with a connecting base 43; the connecting base 43 is connected to the elastic hinge connection 40 via a locking screw 431;

[0094] The main base 42 is provided with a cross spring piece 423;

[0095] A dovetail block seat 41 is disposed at the top of the main base 42 .

[0096] Implementation Method 6: Combination Figures 1 to 9 This embodiment is described. This embodiment is a further limitation of the multifunctional loading head of a low-speed wind tunnel balance described in Embodiment 4. The specific implementation contents are as follows:

[0097] The loading steel cable 6 is connected to the steel cable hook 5 by a circular steel cable connection method or a linear steel cable connection method;

[0098] The annular steel cable connection method is suitable for loading loads of 3 tons to 6 tons;

[0099] The straight steel cable connection method is suitable for loading loads below 3 tons.

[0100] Implementation Method 7: Combination Figures 1 to 9 This embodiment is described. This embodiment is a further limitation of the multifunctional loading head of a low-speed wind tunnel balance described in Embodiment 6. The specific implementation contents are as follows:

[0101] The connection method of the annular steel cable is as follows:

[0102] The cable hook 5 is provided with a first hanging ring 501 ; the root of the loading cable 6 passes through the first hanging ring 501 to form a second hanging ring 601 , so as to realize the connection between the root of the loading cable 6 and the cable hook 5 .

[0103] Implementation Method 8: Combination Figures 1 to 9 This embodiment is described. This embodiment is a further limitation of the multifunctional loading head of a low-speed wind tunnel balance described in Embodiment 6. The specific implementation contents are as follows:

[0104] The straight cable connection method is as follows:

[0105] The cable hook 5 is provided with a center hole; the root of the loading cable 6 is provided with a threaded connecting rod 602; the threaded connecting rod 602 passes through the center hole and is connected to the locking nut 502 to achieve a fixed connection between the root of the loading cable 6 and the cable hook 5.

[0106] Implementation Method 9: Combination Figures 1 to 9 This embodiment is described. This embodiment is a further limitation of the multifunctional loading head of a low-speed wind tunnel balance described in the first embodiment. The specific implementation contents are as follows:

[0107] A hollow chamber 8 is provided at the central position inside the loading head body 1; the hollow chamber 8 is used to place a box balance 666;

[0108] A cassette balance adapter 81 is disposed on the top surface of the hollow chamber 8 ; the cassette balance adapter 81 is used for fixed connection with the cassette balance 666 .

[0109] In this embodiment, when static calibration of the box balance is required, the box balance 666 is placed in the hollow chamber 8 of the loading head body 1, and the box balance 666 is fixedly connected to the box balance adapter 81, and then the loading head can be used to perform static calibration on the box balance.

[0110] In this embodiment, the loading head can calibrate both large external balances and box balances, so it is called a multifunctional loading head.

[0111] In this embodiment, through the above-mentioned structure of the loading head, the box balance and the external balance can use the same loading point during calibration, that is, the loading head is compatible with the calibration of the box balance and the external balance, which improves the versatility of the equipment and reduces the time waste caused by replacing parts.

[0112] Implementation Method 10: Combination Figures 1 to 9 This embodiment is described. This embodiment is a further limitation of the multifunctional loading head of a low-speed wind tunnel balance described in Embodiment 9. The specific implementation contents are as follows:

[0113] The cassette balance adapter 81 includes an upper surface 811 and a boss 812 located at the bottom of the upper surface 811;

[0114] The upper surface 811 is provided with a threaded hole, and the threaded hole is used to connect with the inner hole of the loading head body 1, so that the cassette balance adapter 81 is fixedly connected with the top surface of the hollow chamber 8;

[0115] The boss 812 is provided with an internal through hole 813, and the internal through hole 813 is used to connect with the box balance 666;

[0116] The boss 812 is used as a positioning stop for connecting to the box balance 666.

[0117] In this embodiment, the multifunctional loading head of a low-speed wind tunnel balance realizes the static loading requirements of a large external balance. The loading head has large overall rigidity and is easy to install. It fully considers the system errors that may occur during the loading process (using elastic hinges 4 to reduce system errors), thereby improving the calibration precision and accuracy of the balance.

[0118] In this embodiment, the multifunctional loading head of the low-speed wind tunnel balance is not only used for the calibration of large external balances, but also takes into account the calibration requirements of box balances, thereby improving the utilization rate of the loading head and playing a role in reducing costs and increasing efficiency.

[0119] In this embodiment, the process of using the multifunctional loading head of a low-speed wind tunnel balance to perform static calibration on the balance is roughly as follows:

[0120] First, install the balance into the calibration center of the calibration system;

[0121] Then, the loading head is installed above the balance, and the center of the loading head and the center of the balance are kept in the same axis;

[0122] Then, the laser tracker emits laser to guide the loading head to complete the initial positioning; after the initial positioning, the loading head and the balance are connected together with screws;

[0123] Then, install the elastic hinges of 14 loading points and ensure that the cross springs of the elastic hinges are parallel to the coordinate plane. Connect the loading cables and cable hooks, and apply a certain preload from the force source to keep the loading cables in a taut state.

[0124] Finally, a balance loading table is formulated according to the balance calibration load, and static calibration of the balance is achieved through combined loading of 14 loading points.

[0125] The technical solution provided by the present invention is further described in detail above through several specific implementation modes in order to highlight the advantages and benefits of the technical solution provided by the present invention. However, the several specific implementation modes described above are not intended to be used as limitations on the present invention. Any reasonable changes and improvements to the present invention, reasonable combinations of implementation modes and equivalent substitutions based on the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multifunctional loading head for a low-speed wind tunnel balance, characterized in that: The loading head comprises: a loading head body (1), four detachable loading head arms (2), two laser positioning target seats (3), and fourteen elastic hinge connections (40); Two detachable loading head support arms (2) are respectively arranged at the front and rear ends of the loading head body (1), and the two detachable loading head support arms (2) are symmetrically arranged along the left and right sides of one end of the loading head body (1); the vertical axes of the four detachable loading head support arms (2) are parallel; A laser positioning target seat (3) is respectively provided on the front portions of both ends of the loading head body (1); Two protruding brackets (7) are symmetrically arranged on the left and right sides of the middle section of the loading head body (1); An elastic hinge connection (40) is provided on the vertically upward side of one end of the detachable loading head support arm (2) away from the loading head body (1); Four elastic hinge connection points (40) are symmetrically arranged on the left and right sides of the front and rear ends of the loading head body (1) near the detachable loading head support arm (2); Two elastic hinge connection points (40) are symmetrically arranged on the front and rear sides of the protruding bracket (7); The vertically downward surface of the protruding bracket (7) is provided with an elastic hinge connection (40); Each elastic hinge connection (40) is connected to an elastic hinge (4); each elastic hinge (4) is connected to a loading steel cable (6) via a steel cable hook (5); A hollow chamber (8) is provided at a central position inside the loading head body (1); the hollow chamber (8) is used to place a box balance (666); A cassette balance adapter (81) is provided on the top surface of the hollow chamber (8); the cassette balance adapter (81) is used to be fixedly connected to the cassette balance (666); The cassette balance adapter (81) comprises an upper surface (811) and a boss (812) located at the bottom of the upper surface (811); The upper surface (811) is provided with a threaded hole, the threaded hole being used to connect with the inner hole of the loading head body (1), so that the cassette balance adapter (81) is fixedly connected to the top surface of the hollow chamber (8); The boss (812) is provided with an internal through hole (813), and the internal through hole (813) is used to connect with a box balance (666); The boss (812) is used as a positioning stop for connection with the box balance (666).

2. The multifunctional loading head of a low-speed wind tunnel balance according to claim 1, characterized in that: The elastic hinge (4) is a cross elastic hinge.

3. The multifunctional loading head of a low-speed wind tunnel balance according to claim 1, characterized in that: A dovetail block seat (41) is provided at the top of the elastic hinge (4); a dovetail connecting portion (51) is provided at the bottom of the steel cable hook (5); the steel cable hook (5) is fixedly connected to the elastic hinge (4) by an anti-slip screw (411), and the dovetail block seat (41) is connected to the dovetail connecting portion (51).

4. The multifunctional loading head of a low-speed wind tunnel balance according to claim 3 is characterized in that: The elastic hinge (4) further comprises a connecting base (43) and a main base (42); The bottom of the main base (42) is fixedly connected to a connecting base (43); the connecting base (43) is connected to the elastic hinge connection (40) via a locking screw (431); The main base (42) is provided with cross-shaped spring pieces (423); A dovetail block seat (41) is provided at the top end of the main base (42).

5. The multifunctional loading head of a low-speed wind tunnel balance according to claim 3 is characterized in that: The loading steel cable (6) is connected to the steel cable hook (5) by adopting a circular steel cable connection method or a linear steel cable connection method; The annular steel cable connection method is suitable for loading loads of 3 tons to 6 tons; The straight steel cable connection method is suitable for loading loads below 3 tons.

6. The multifunctional loading head of a low-speed wind tunnel balance according to claim 5, characterized in that: The connection method of the annular steel cable is as follows: The steel cable hook (5) is provided with a first hanging ring (501); the root of the loading steel cable (6) passes through the first hanging ring (501) to form a second hanging ring (601), thereby achieving connection between the root of the loading steel cable (6) and the steel cable hook (5).

7. The multifunctional loading head of a low-speed wind tunnel balance according to claim 5, characterized in that: The straight cable connection method is as follows: The steel cable hook (5) is provided with a central hole; the root of the loading steel cable (6) is provided with a threaded connecting rod (602); the threaded connecting rod (602) passes through the central hole and is connected to the locking nut (502), thereby achieving a fixed connection between the root of the loading steel cable (6) and the steel cable hook (5).

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