A six-component ring balance

Abstract

The present invention discloses a six-component ring balance, which is an integrated structure, including a balance fixing section for fixing the balance, a balance measuring section provided with six component measuring elements, and a balance cantilever connecting section for connecting a force measuring model, wherein one end of the balance measuring section is provided with the balance fixing section, and the other end of the balance measuring section is provided with the balance cantilever connecting section. The present invention has a unique structure, breaking through the limitations of the traditional rod-type wind tunnel balance structure, effectively shortening the size of the balance measuring section, reducing the difference between the inner and outer diameters of the balance, reducing the installation space requirements of the balance, and being able to meet more wind tunnel force measurement test needs; the balance has relatively good rigidity, has more advantages in force measurement in a vibration test environment, has strong anti-interference ability in resistance measurement, has high balance measurement accuracy, and has high engineering application value.

Description

Technical Field

[0001] The invention relates to the technical field of wind tunnel aerodynamic load force measuring balance, in particular to a six-component ring balance. Background Art

[0002] The wind tunnel balance (balance for short) is a key measuring device in wind tunnel force tests. It is used to measure the size, direction and point of action of aerodynamic loads (force and torque) acting on the model. When it comes to force tests involving jets, propellers, etc. that require central ventilation or the installation of a rotating shaft, the balance can only adopt a ring structure due to model space limitations. The traditional six-component ring balance is modified on the basis of a conventional wind tunnel balance. It is generally made by punching a hole in the middle of a conventional balance and adopts a multi-section series rod structure. The balance is relatively long, and more space is required between the inner and outer diameters of the balance. The size of the middle hole is greatly restricted. During the test, the balance deforms greatly and is prone to vibration. Many tests can only change the original structure of the model or even cannot be carried out because it is difficult to arrange the balance and meet the deformation gap requirements, making it difficult to obtain real aerodynamic forces. Summary of the invention

[0003] The purpose of the present invention is to provide a six-component ring balance in order to solve the above-mentioned problem. The measuring section length of the six-component ring balance designed by the present invention is greatly reduced, the space requirement between the inner and outer diameters of the balance is reduced, the size restriction of the middle hole is small, and it has the same level of accuracy as a conventional six-component force measuring balance. In particular, the drag has a strong ability to resist interference from other component loads, and can complete the accurate measurement of aerodynamic loads in wind tunnel tests.

[0004] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0005] A six-component ring balance is an integrated structure, comprising a balance fixing section for fixing the balance, a balance measuring section provided with six component measuring elements, and a balance cantilever connecting section for connecting a force measuring model; the balance fixing section is provided on one side of the balance measuring section, and the balance cantilever connecting section is provided on the other side of the balance measuring section.

[0006] Further configuration: the balance measuring section includes side force, yaw moment and rolling moment measuring elements, lift and pitch moment measuring elements, and drag measuring elements. The side force, yaw moment and rolling moment measuring elements and the lift and pitch moment measuring elements are in the same longitudinal section, are nested with the drag measuring element, and are separated by a curved groove. The side force, yaw moment and rolling moment measuring elements are symmetrical up and down, and the lift and pitch moment measuring elements are symmetrical left and right, and all of them are four rectangular beams.

[0007] It is further arranged that the resistance measuring element is composed of four rectangular beams respectively located at the directions of ±45° and ±135° of the central axis, the four rectangular beams are symmetrical on all sides and are respectively inclined at ±45° to the horizontal plane.

[0008] Further configuration: the curved groove is perpendicular to the horizontal plane of the balance, symmetrical up and down, and is composed of three straight grooves. The middle straight groove is parallel to the longitudinal section, the two straight grooves on both sides form a certain angle with the middle straight groove and are symmetrical left and right, and the three straight grooves are transitioned by arcs.

[0009] It is further provided that: the balance fixing section, the balance measuring section and the balance cantilever connecting section are made of a whole piece of alloy steel material and are an integrated structure.

[0010] Further configuration: resistance strain gauges are symmetrically pasted on the front and rear side surfaces of the four rectangular beams of the resistance measuring element, and 4 strain gauges are pasted on each rectangular beam, respectively located in the middle of the upper and lower ends of the front side surface and the rear side surface, the direction of the strain gauge is parallel to the long side of the rectangular beam, and the top end coincides with the rounded edge of the root of the rectangular beam, and a total of 16 resistance strain gauges form a resistance measuring Wheatstone bridge; resistance strain gauges are pasted on the sides of the 8 column beams of the yaw moment and rolling moment measuring element and the lift and pitch moment measuring element to form a Wheatstone bridge for measuring lift, side force, yaw moment, pitch moment and rolling moment, respectively.

[0011] It is further provided that a keyway is provided on the inner side of the balance fixing section, and the balance fixing section is fixedly connected to the supporting device by a flange connection or a column connection.

[0012] Further configuration: a keyway is provided on the outer side of the balance cantilever connecting section, and the balance cantilever connecting section is connected to the force measuring model by a conical surface connection or a column connection; when the conical surface connection is adopted, a thread is provided at the front end of the balance cantilever connecting section for disassembly and assembly of the conical surface.

[0013] It is further provided that: the overall appearance of the balance fixing section, the balance measuring section and the balance cantilever connecting section is an axial structure, and the middle hole runs through the whole.

[0014] A six-component ring balance as described in the application is characterized in that it includes a six-component ring balance, a support rod is installed on one side of the balance fixing section of the six-component ring balance, the six-component ring balance is connected to the support rod by key positioning and cylindrical connection, and is locked by cylindrical pins and screws, a ventilation duct is arranged on the inner side of the support rod, the ventilation duct can be in contact with the balance fixing section, and there is a circumferential gap between the ventilation duct and the balance measuring section and the balance cantilever connecting section; a force measuring model is installed at one end of the balance cantilever connecting section of the six-component ring balance, the six-component ring balance is connected to the force measuring model by key positioning and cone connection, and is tightened by fasteners; a balance protection cover is arranged on the outside of the six-component ring balance, the balance protection cover is in contact with the balance fixing section, and there is a gap between the balance protection cover and the balance measuring section and the balance cantilever connecting section.

[0015] It is further configured that the balance protection cover is connected to the six-component ring balance via threads.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The balance has a unique structure, which breaks through the limitations of the traditional rod-type wind tunnel balance structure. The size of the balance measuring section is effectively shortened, and the difference between the inner and outer diameters of the balance is reduced, which reduces the installation space requirement for the balance and can meet more wind tunnel force test needs. The balance has relatively good stiffness and is more advantageous in force measurement in a vibration test environment. The resistance measurement has strong anti-interference ability. The balance has high measurement accuracy and can effectively make up for the shortcomings of the traditional ring balance, and has high application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art 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 paying creative labor.

[0019] Figure 1 It is a front view of a six-component ring balance according to the present invention;

[0020] Figure 2 is a top view of a six-component ring balance according to the present invention;

[0021] Figure 3 yes Figure 2 AA section view;

[0022] Figure 4 yes Figure 2 BB cross-sectional view;

[0023] Figure 5 yes Figure 2 CC section view;

[0024] Figure 6 yes Figure 2 DD cross-sectional view;

[0025] Figure 7 It is a schematic diagram of the assembly structure of a six-component ring balance according to the present invention;

[0026] Figure 8 This is a schematic diagram of the structure of the pasting position of the strain gauge of the six-component ring balance resistance measurement element of the present invention (the numbers in brackets represent the numbers of the strain gauges pasted at the same position on the other side);

[0027] Fig. 9 It is a schematic diagram of a six-component ring balance resistance Wheatstone bridge assembly method described in the present invention.

[0028] The following are the descriptions of the reference numerals:

[0029] 1. Balance fixing section; 2. Balance measuring section; 3. Balance cantilever connecting section; 4. Curved slot; 5. Side force, yaw moment and roll moment measuring elements; 6. Lift and pitch moment measuring elements; 7. Resistance measuring elements; 8. Support rod; 9. Ventilation duct; 10. Balance protective cover; 11. Force measuring model; 12. Fasteners; 13. Six-component ring balance. DETAILED DESCRIPTION

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0032] The present invention will be further described below in conjunction with the accompanying drawings:

[0033] like Figure 1 , 2 As shown in Figures , 3, 4, 5, 6, 8 and 9, a six-component ring balance is an integrated structure, including a balance fixing section 1 for fixing the balance, a balance measuring section 2 provided with six component measuring elements, and a balance cantilever connecting section 3 for connecting a force measuring model; the balance fixing section 1 is provided on one side of the balance measuring section 2, and the balance cantilever connecting section 3 is provided on the other side of the balance measuring section 2.

[0034] Further configuration: the balance measuring section 2 includes a side force, yaw moment and rolling moment measuring element 5, a lift and pitch moment measuring element 6, and a drag measuring element 7. The side force, yaw moment and rolling moment measuring element 5 and the lift and pitch moment measuring element 6 are in the same longitudinal section, and are nested with the drag measuring element 7 and separated by a curved groove 4. The side force, yaw moment and rolling moment measuring element 5 are symmetrical in the vertical direction, and the lift and pitch moment measuring element 6 are symmetrical in the left and right direction, and are all four rectangular beams; the drag measuring element 7 consists of four The balance is composed of rectangular beams located at ±45° and ±135° directions of the central axis, which are symmetrical all around and inclined at ±45° to the horizontal plane respectively; the curved groove 4 is perpendicular to the horizontal plane of the balance, symmetrical up and down, and is composed of 3 straight grooves, the middle straight groove is parallel to the longitudinal section, the two straight grooves on both sides form a certain angle with the middle straight groove and are symmetrical left and right, and the three straight grooves are transitioned by arcs; the balance fixing section 1, the balance measuring section 2, and the balance cantilever connecting section 3 are made of a whole piece of alloy steel material and are an integrated structure; the resistance The resistance strain gauges are symmetrically pasted on the front and rear sides of the four rectangular beams of the force measuring element 7. Four strain gauges are pasted on each rectangular beam, which are respectively located in the middle of the upper and lower ends of the front side and the rear side. The direction of the strain gauge is parallel to the long side of the rectangular beam, and the top coincides with the rounded edge of the root of the rectangular beam. A total of 16 resistance strain gauges form a resistance measurement Wheatstone bridge; the resistance strain gauges are pasted on the sides of the 8 column beams of the yaw moment and rolling moment measuring element 5 and the lift and pitch moment measuring element 6 to form a resistance measurement Wheatstone bridge for measuring lift, side force, and yaw force respectively. A Wheatstone bridge for moment, pitch moment and rolling moment; a keyway is arranged on the inner side of the balance fixed section 1, and the balance fixed section 1 is fixedly connected to the supporting device by flange connection or column connection; a keyway is arranged on the outer side of the balance cantilever connecting section 3, and the balance cantilever connecting section 3 is connected to the force measuring model by conical surface connection or column connection; when the conical surface connection is adopted, a thread is arranged at the front end of the balance cantilever connecting section 3 for conical surface disassembly and assembly; the overall shape of the balance fixed section 1, the balance measuring section 2 and the balance cantilever connecting section 3 is an axial structure, and the middle hole runs through the whole.

[0035] like Figure 7As shown, a six-component ring balance is used, including a six-component ring balance 13, a support rod 8 is installed on one side of the balance fixing section 1 of the six-component ring balance 13, the six-component ring balance 13 is connected to the support rod 8 by key positioning and cylindrical connection, and is locked by cylindrical pins and screws, a ventilation pipe 9 is arranged on the inner side of the support rod 8, the ventilation pipe 9 can contact with the balance fixing section 1, and there is a circumferential gap between the ventilation pipe 9 and the balance measuring section 2 and the balance cantilever connecting section 3; a force measuring model 11 is installed on one end of the balance cantilever connecting section 3 of the six-component ring balance 13, the six-component ring balance 13 is connected to the force measuring model 11 by key positioning and cone connection, and is pressed by a fastener 12; a balance protection cover 10 is arranged on the outer side of the six-component ring balance 13, the balance protection cover 10 is in contact with the balance fixing section 1, and there is a gap between the balance protection cover 10 and the balance measuring section 2 and the balance cantilever connecting section 3.

[0036] Further configuration: the balance protection cover 10 is connected to the six-component ring balance 13 via threads.

[0037] In a typical application case of a six-component ring balance described in the present invention, the design load of the balance is: lift 2000N, side force 2000N, drag 3000N, pitch moment 300N·m, yaw moment 200N·m, roll moment 50N·m, balance measuring section 2 length 68mm, inner hole diameter Φ108mm, outer diameter Φ144mm. If a traditional ring balance structure is used, the length of the balance measuring section 2 is not less than 100mm, and the inner hole diameter is not greater than Φ80mm.

[0038] Working principle and working process of the present invention

[0039] The six-component ring balance is a strain gauge wind tunnel balance, which is used to measure the various components of aerodynamic forces acting on the force measuring model 11. In the wind tunnel test, the aerodynamic force acting on the force measuring model 11 is transmitted to the balance measuring section 2 through the balance cantilever connection section 3, so that the side force, yaw moment and rolling moment measuring element 5, lift and pitch moment measuring element 6, and drag measuring element 7 are deformed, so that the Wheatstone bridge attached to the surface loses its original balance, thereby generating a voltage signal increment, and the aerodynamic force measurement is completed through the corresponding relationship between the bridge output voltage and the load.

[0040] The four resistance measuring beams are inclined at ±45° and are completely symmetrical with respect to the longitudinal and transverse axes. They have good resistance to interference from other loads. When subjected to resistance, the deformation of the four resistance measuring beams is symmetrical up and down. When subjected to lift, side force, pitch moment, and yaw moment, the deformation of the four resistance measuring beams is either antisymmetric up and down or antisymmetric left and right, which can be balanced by a Wheatstone bridge without generating output. When subjected to rolling moment, no output is generated due to the high stiffness in the rolling direction.

[0041] The four resistance measuring beams of the six-component ring balance 13 are staggered with the combined measuring elements for measuring lift, side force, pitch moment, yaw moment and roll moment, and can be embedded in each other, and the stiffness is balanced through the curved groove 4, which effectively shortens the length of the balance measuring section 2;

[0042] The six-component ring balance 13 is short in length. On the one hand, the cantilever is short when measuring force, the rigidity is good, and the deformation is small, which is conducive to model installation and test force measurement; on the other hand, the center of the balance is close to the pressure center of the force measurement model 11, and the aerodynamic load generated is relatively matched, the balance output is more balanced, and the accuracy is better;

[0043] The connection and measuring elements of the six-component ring balance 13 can all be located in a narrow annular space, requiring a smaller model installation space, and the center hole can be larger, making it easier to ventilate the middle or install the rotating shaft, thereby enhancing the test capability. The balance protection cover 10 plays a role in protecting the balance and isolating the influence of crossflow.

[0044] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A six-component ring balance, characterized in that: The six-component ring balance is an integrated structure, comprising a balance fixing section (1) for fixing the balance, a balance measuring section (2) provided with six component measuring elements, and a balance cantilever connecting section (3) for connecting a force measuring model; the balance fixing section (1) is provided on one side of the balance measuring section (2), and the balance cantilever connecting section (3) is provided on the other side of the balance measuring section (2); The balance measurement section (2) comprises a side force, yaw moment and rolling moment measuring element (5), a lift and pitch moment measuring element (6), and a drag measuring element (7); the side force, yaw moment and rolling moment measuring element (5) and the lift and pitch moment measuring element (6) are located in the same longitudinal section, are nested with the drag measuring element (7), and are separated by a curved groove (4); the side force, yaw moment and rolling moment measuring element (5) are vertically symmetrical, and the lift and pitch moment measuring element (6) are bilaterally symmetrical, and are all four rectangular beams; The resistance measuring element (7) is composed of four rectangular beams located at ±45° and ±135° directions of the central axis, respectively. The four rectangular beams are symmetrical all around and are inclined at ±45° to the horizontal plane respectively. Resistance strain gauges are symmetrically attached to the front and rear side surfaces of the four rectangular beams of the resistance measuring element (7), and four strain gauges are attached to each rectangular beam, respectively located in the middle of the upper and lower ends of the front side surface and the rear side surface, the direction of the strain gauge is parallel to the long side of the rectangular beam, and the top end coincides with the rounded edge of the root of the rectangular beam, and a total of 16 resistance strain gauges form a resistance measuring Wheatstone bridge; resistance strain gauges are attached to the side surfaces of the eight column beams of the yaw moment and rolling moment measuring element (5) and the lift and pitch moment measuring element (6), respectively, to form a Wheatstone bridge for measuring lift, side force, yaw moment, pitch moment and rolling moment.

2. A six-component ring balance according to claim 1, characterized in that: The curved groove (4) is perpendicular to the horizontal plane of the balance, symmetrical up and down, and is composed of three straight grooves. The middle straight groove is parallel to the longitudinal section, and the two straight grooves on both sides form a certain angle with the middle straight groove and are symmetrical left and right. The three straight grooves are transitioned by arcs.

3. A six-component ring balance according to claim 1, characterized in that: The balance fixing section (1), the balance measuring section (2), and the balance cantilever connecting section (3) are made of a whole piece of alloy steel material and are an integrated structure.

4. A six-component ring balance according to claim 1, characterized in that: A keyway is provided on the inner side of the balance fixing section (1), and the balance fixing section (1) is fixedly connected to the supporting device by means of a flange connection or a column connection.

5. A six-component ring balance according to claim 1, characterized in that: A keyway is provided on the outside of the balance cantilever connection section (3), and the balance cantilever connection section (3) is connected to the force measurement model by means of a conical surface connection or a column connection. When the conical surface connection is adopted, a thread is provided at the front end of the balance cantilever connection section (3) for disassembly and assembly of the conical surface.

6. A six-component ring balance according to claim 1, characterized in that: The overall appearance of the balance fixing section (1), the balance measuring section (2), and the balance cantilever connecting section (3) is an axial structure, and the middle hole runs through the whole.

7. A measuring device using the six-component ring balance according to any one of claims 1 to 6, characterized in that: The invention comprises a six-component ring balance (13), wherein a support rod (8) is installed on one side of a balance fixing section (1) of the six-component ring balance (13), the six-component ring balance (13) is connected to the support rod (8) by key positioning and cylindrical connection, and is locked by a cylindrical pin and a screw, a ventilation duct (9) is arranged on the inner side of the support rod (8), the ventilation duct (9) is in contact with the balance fixing section (1), and a circumferential gap exists between the ventilation duct (9) and the balance measuring section (2) and the balance cantilever connecting section (3); the six-component ring balance (13) is connected to the support rod (8) by key positioning and cylindrical connection, and is locked by a cylindrical pin and a screw, and a ventilation duct (9) is arranged on the inner side of the support rod (8), the ventilation duct (9) is in contact with the balance fixing section (1), and a circumferential gap exists between the ventilation duct (9) and the balance measuring section (2) and the balance cantilever connecting section (3); A force measuring model (11) is installed at one end of a balance cantilever connecting section (3) of a six-component ring balance (13); the six-component ring balance (13) is connected to the force measuring model (11) by key positioning and cone connection, and is compressed by a fastener (12); a balance protection cover (10) is arranged on the outside of the six-component ring balance (13); the balance protection cover (10) is in contact with the balance fixing section (1), and there is a gap between the balance protection cover (10) and the balance measuring section (2) and the balance cantilever connecting section (3).

8. The measuring device of a six-component ring balance according to claim 7, characterized in that: The balance protection cover (10) is connected to the six-component ring balance (13) via threads.

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