Three-way force measuring balance, measuring unit, measuring structure and measuring method

Abstract

The invention relates to a three-way force measuring balance, a measuring unit, a measuring structure and a measuring method, which are used for solving the problem that thrust parameters under various working conditions cannot be measured when an engine is mounted on a 45-degree mounting test bed at present. The device comprises a stand column, one end face of the stand column is connected with a to-be-measured object, and the other end face is connected with a fixed object; a plurality of groups of force sensor strain patches are uniformly arranged on each side surface of the stand column; each group of force sensor strain patches comprises an axial strain patch and a radial strain patch; the axial strain patch is arranged on the side surface of the stand column, and the length direction of the axial strain patch is parallel to the axial direction of the stand column; the radial strain patch is arranged on the side face of the stand column, and the length direction of the radial strain patch is perpendicular to the axial direction of the stand column; and a gap is formed between the axial strain patch and the radial strain patch.

Description

Technical Field

[0001] The present invention relates to a force measuring device and method, and in particular to a three-axis force measuring balance, a measuring unit, a measuring structure and a measuring method. Background Art

[0002] The engine needs to undergo thrust testing during the research and development stage, and the thrust values ​​under various operating conditions need to be obtained during the thrust testing.

[0003] When the engine is operating at high power, the engine support frame deforms outward, which will introduce a lateral force component into the thrust actually measured by the sensor. As a result, the force value measured by the axial force sensor not only includes the thrust of the engine under test, but also has an obvious lateral force influence, causing the thrust finally measured by the sensor to deviate significantly from the actual thrust. This is especially true in a non-vertically installed test bench, such as when the engine is installed on a test bench installed at a 45° angle. The engine's own weight will also aggravate the influence of the lateral force, resulting in inaccurate measurement results.

[0004] This lateral force will also affect the measurement of the three-dimensional forces of the engine, resulting in an additional force being obtained when measuring the three-dimensional forces, making the measured force biased. Summary of the invention

[0005] The present invention provides a three-axis force measurement balance, a measurement unit, a measurement structure and a measurement method, which are used to solve the problem that the current engine cannot obtain accurate thrust during the thrust test. The device and the corresponding method provided in the present invention provide a basis for verifying whether the engine reaches the theoretical design parameters, and provide data support for the improvement and development of subsequent engines.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] A three-axis force measurement balance, which is special in that it comprises a column, one end face of the column is connected to the object to be measured, and the other end face is connected to a fixed object; each side face of the column is evenly provided with multiple groups of force sensor strain patches;

[0008] Each group of force sensor strain patches includes an axial strain patch and a radial strain patch. The axial strain patch is arranged on the side of the column and its length direction is parallel to the axial direction of the column; the radial strain patch is arranged on the side of the column and its length direction is perpendicular to the axial direction of the column; there is a gap between the axial strain patch and the radial strain patch.

[0009] Furthermore, the force sensor strain patches arranged on each side of the column are three groups or two groups.

[0010] Further, three groups of the force sensor strain patches are respectively arranged at the two ends and the middle of the column; or, two groups of the force sensor sensing patches are respectively arranged at the two ends of the column.

[0011] A three-axis force measurement unit, which is special in that it comprises a plurality of the above-mentioned three-axis force measurement balances, a base, a shell and an upper cover;

[0012] The shell is a hollow columnar structure, the base and the shell are fixedly connected to form a cavity; the upper cover is arranged at the opening of the cavity;

[0013] A plurality of the three-axis force measurement balances are vertically placed in the cavity, and the upper end surface of the column is connected to the lower end surface of the upper cover, and the lower end surface of the column is connected to the upper end surface of the base;

[0014] The upper end surface of the upper cover body is used for placing the test piece.

[0015] Furthermore, there are four three-axis force measuring balances, which are vertically and evenly placed in the cavity; and the shell is a hollow cylindrical structure.

[0016] A three-axis force measurement structure, which is special in that it includes a second upper base plate, a second lower base plate and a three-axis force measurement device;

[0017] The three-axis force measurement device comprises a plurality of the above-mentioned three-axis force measurement units;

[0018] The upper end surface of the upper cover of the three-axis force measurement unit is connected to the lower end surface of the second upper base plate, and the lower end surface of the base of the three-axis force measurement unit is connected to the upper end surface of the second lower base plate.

[0019] The second upper base plate and the second lower base plate are annular structures with the same structure;

[0020] Multiple three-axis force measurement units are evenly distributed along the circumference;

[0021] The upper end surface of the second upper base plate is used for placing the test piece.

[0022] Furthermore, it also includes an axial force measuring device, the upper surface of the axial force measuring device is connected to the lower surface of the second lower base plate, the axial force measuring device includes a first upper base plate, a first lower base plate, and a plurality of axial force measuring units evenly distributed between the first upper base plate and the first lower base plate; the upper end surface of the first upper base plate is connected to the lower surface of the second lower base plate;

[0023] The axial force measuring unit comprises a limit device, a force conducting steel ball, an axial force sensing unit, a limit nut, a locking nut and at least two bolts, wherein the limit nut and the locking nut correspond to the bolts one by one;

[0024] The first upper bottom plate is provided with bolt through holes having the same number as the bolts, wherein the bolt through holes are rectangular holes or waist-shaped holes and are extended in the radial direction of the first upper bottom plate; the tail of the bolt passes through the bolt through hole, the limit nut and the locking nut in sequence and is fixedly connected to the first lower bottom plate;

[0025] The locking nut is used to fix the tail of the bolt on the first lower base plate;

[0026] The limiting device is connected to the lower surface of the first upper base plate, and a groove with a semicircular cross section is provided on the lower end surface thereof, the extension direction of the groove is consistent with the extension direction of the bolt through hole, and the radius of the groove cross section is greater than the radius of the force conducting steel ball;

[0027] The axial force sensing unit is connected to the upper surface of the first lower base plate;

[0028] The axial force conducting steel ball is located between the limit device and the axial force sensing unit, and the axial force conducting steel ball is in contact with the groove and the sensitive surface of the axial force sensing unit respectively;

[0029] When the axial force sensing unit outputs a maximum value, the distance between the limit nut and the first upper base plate is 0;

[0030] The first upper base plate can move relatively along the axial direction of the bolt.

[0031] Furthermore, the first upper base plate and the first lower base plate are annular structures with the same structure;

[0032] A fixing threaded hole is provided on the upper surface of the first lower base plate, and the axial force sensing unit is connected to the upper surface of the first lower base plate through the fixing threaded hole.

[0033] A three-axis force measurement method is special in that, based on the above three-axis force measurement structure, the steps are as follows:

[0034] Step 1, calibrating a three-axis force measurement device;

[0035] Step 2, installing the three-axis force measurement device between the engine test bench and the engine test frame;

[0036] Step 3, obtaining the actual lateral force value, longitudinal force value and / or actual torque at any time through force analysis.

[0037] A three-axis force measurement method is special in that, based on the above three-axis force measurement structure, the steps are as follows:

[0038] Step 1, calibrating the axial force measuring device and the three-axis force measuring device respectively;

[0039] Step 2, connecting the axial force measuring device and the three-axis force measuring device and installing them between the engine test bench and the engine test frame;

[0040] Step 3, obtaining the actual lateral force value, longitudinal force value, actual torque and / or axial force at any time through force analysis.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. In the present invention, the axial force measuring device and the three-axis force measuring device work together to enable calibration according to the overall output during the calibration process, and the calibration is consistent with the actual measurement, providing important data reference for improving the reliability of the engine.

[0043] 2. The axial force measuring device provided in the present invention can only measure the axial force, thereby ensuring the accuracy of the measurement results and providing data support for engine performance design.

[0044] 3. In the present invention, since both the upper base plate and the lower base plate are annular structures, the deformation of the tower frame in the plane direction due to extrusion during the engine test will be greatly reduced.

[0045] 4. The present invention can not only realize the accurate measurement of thrust force value, but also realize the lateral force value, torque and other technical parameters of each direction force value under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 Schematic diagram of the structure of the axial force measuring device in an embodiment of the present invention

[0047] Figure 2 for Figure 1 Partial cross-sectional view;

[0048] Figure 3 This is a schematic diagram of the structure of the first lower base plate in an embodiment of the present invention;

[0049] Figure 4 It is a structural schematic diagram of an axial force measuring balance in an embodiment of the present invention;

[0050] Figure 5 It is a structural schematic diagram of a three-axis force measurement balance in an embodiment of the present invention;

[0051] Figure 6 It is a structural schematic diagram of a three-axis force measurement unit in an embodiment of the present invention;

[0052] Figure 7 It is a structural schematic diagram of a three-axis force measurement device in an embodiment of the present invention;

[0053] Figure 8It is a schematic diagram of the installation relationship between the force measurement structure and the test frame and the test bench in an embodiment of the present invention.

[0054] The reference numerals are as follows:

[0055] 1. Bolt through hole; 2. First threaded hole; 3. Bolt; 5. Limit nut; 6. Force conduction steel ball; 7. Axial force sensor; 9. Second threaded hole; 10. Fixed threaded hole; 11. Limit device; 13. First upper base plate; 14. First lower base plate; 15. Base; 16. Shell; 17. Upper cover; 19. Column; 20. Force sensor strain patch; 201. Axial sensor strain patch; 202. Radial sensor strain patch; 21. Test bench; 22. Force measurement structure; 23 Test frame; 24. Second upper base plate; 25. Second lower base plate; 26. Locking nut. DETAILED DESCRIPTION

[0056] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0057] The present invention provides a force measurement structure 22, comprising an axial force measurement device and a three-axis force measurement device connected up and down.

[0058] An axial force measuring device, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, it includes an annular first upper base plate 13 , an annular first lower base plate 14 , N limit devices 11 , N force conducting steel balls 6 , N axial force sensors 7 and 2N bolts 3 .

[0059] The limit device 11 and the axial force sensor 7 are arranged in one-to-one correspondence, and the force conduction steel ball 6 is located between the limit device 11 and the axial force sensor 7, so that the force conduction steel ball 6 contacts the lower end of the limit device 11 and the input end of the axial force sensor 7 respectively.

[0060] The lower end surface of the limit device 11 is provided with a groove with a semicircular cross section, so that the force conducting steel ball 6 is located in the groove and can only move radially along the groove. The width of the groove is larger than the diameter of the force conducting steel ball 6, so that only the vertex of the conducting steel ball 6 contacts the limit device 11, so that the force can only be transmitted through the vertex of the axial conducting steel ball 6. Therefore, the axial force sensor 7 can only measure the axial force.

[0061] The upper end surface of the limiting device 11 is connected to the lower surface of the first upper base plate 13 , and the axial force sensor 7 is connected to the upper surface of the first lower base plate 14 through the fixing threaded hole 10 .

[0062] The tail of the bolt 3 passes through the bolt through hole 1 set on the first upper base plate 13, so that the head of the mounting bolt 3 contacts the upper surface of the first upper base plate 13, and the screw diameter of the bolt 3 is smaller than the radial length of the bolt through hole 1 by 0.5 to 3 mm, ensuring that there is enough space for buffering when deformation occurs in the lateral expansion direction; the bolt through hole 1 can be a rectangular hole, a waist-shaped hole, or a diamond-shaped hole; after the tail of the bolt 3 is inserted into the bolt through hole 1, it is finally fixed in the first lower base plate 14.

[0063] Each bolt 3 is provided with a limiting nut 5 and a locking nut 26. The limiting nut 5 is located at the upper end of the screw rod of the bolt 3, and there is a gap of 1-3 mm between the limiting nut 5 and the lower surface of the first upper base plate 13, and the gap is used for buffering; the locking nut 26 is located at the lower end of the screw rod of the bolt 3 and contacts with the upper surface of the first lower base plate 14, and is used to fix the tail of the bolt 3 in the first lower base plate 14.

[0064] The buffering force of the distance between the lower surface of the first upper base plate 13 and the limiting nut 5 is less than or equal to the maximum range of the axial force sensing unit 7, thereby ensuring the safety of the use of the axial force sensing unit 7 and preventing inaccurate measurement of the axial force sensing unit 7.

[0065] The upper surface of the first upper base plate 13 is provided with a first blind-hole-shaped threaded hole 2 for connecting with other devices. The lower surface of the first lower base plate 14 is provided with a second blind-hole-shaped threaded hole 9 for connecting with other devices.

[0066] When N=8, the thrust of the engine is the resultant axial force of the eight axial force sensing units 7, F=F1+F2+F3+F4+F5+F6+F7+F8.

[0067] A three-axis force measurement device, such as Figure 7 As shown, it includes a second upper base plate 24, a second lower base plate 25 and eight three-axis force measurement units. The three-axis force measurement unit, such as Figure 6 As shown, it includes a base 15, a shell 16, an upper cover 17 and four three-axis force measuring balances. Figure 5 As shown, it includes a column 19, the column 19 is a square structure, and in other embodiments, the column 19 can also be a cylindrical shape, and at least two force sensor strain patches 20 are arranged on each side, and the force sensor strain patch 20 includes an axial strain patch 201 and a radial strain patch 202. The axial strain patch 201 and the radial strain patch 202 are both arranged on the side of the column 19, and the axial strain patch 201 and the radial strain patch 202 do not contact each other.

[0068] A plurality of columns 19 attached to the force sensor strain patches are evenly distributed in the cavity formed by the base 15, the shell 16 and the upper cover 17. The base 15, the barrel-shaped shell 16 and the upper cover 17 are sequentially connected to form the cavity.

[0069] In the three-axis force measuring device, eight three-axis force measuring units are evenly distributed between the second upper base plate 24 and the second lower base plate 25 , and both the second upper base plate 24 and the second lower base plate 25 are annular structures.

[0070] A single three-phase force measuring unit can simultaneously sense three-dimensional orthogonal forces (F X 、F Y 、F Z ) and torque (M X 、M Y 、M Z ), can be used to measure forces with changing directions and magnitudes. The combined multi-component force measurement platform adopts a split layout, with the elastic body combination bearing the load, and the sensitive elements that sense the changes in force and torque also adopt a sensor combination. It has a symmetrical design, simple structure, reasonable layout, and a locking mechanism for installation protection. It can simultaneously measure the force values ​​in the three directions of Fx, Fy, and Fz and the torque values ​​in the three directions of Mx, My, and Mz.

[0071] like Figure 8 As shown, the axial force measuring device and the three-way force measuring device are connected up and down to form a force measuring structure 22. The upper end face and the lower end face of the force measuring structure 22 are respectively connected to the test bench 21 and the test frame 23 on which the engine is installed and installed at 45 degrees, so as to test the engine and obtain the parameters on the engine.

[0072] The three-axis force measurement method based on the above device has the following specific steps:

[0073] Step 1: First, the axial force measuring device and the three-axis force measuring device are calibrated during the production process for each built-in axial force sensor 7 and force sensor sensing patch 20 to ensure the accuracy of the force output and detection in each direction. The three-axis force measurement balance is calibrated as a whole after production is completed to ensure the accuracy of the overall output force value parameters.

[0074] Step 2: The axial force measuring device and the three-axis force measuring device are installed between the engine test bench and the engine, and various force values ​​under various working conditions are measured. z is the vertical force value, F x is the tangential force value, F y is the force value in the normal direction.

[0075] Set a direction of the axial force measuring device and the three-axis force measuring device that passes through the origin horizontally as the lateral thrust direction for the purpose of unifying the benchmarks during production and testing. The right side facing the front of the axial force measuring device and the three-axis force measuring device is 0°, and the angle θ is determined by deviating in the clockwise direction. i In this embodiment, i≤8, and the angle of each force value is a fixed value according to the actual deviation angle.

[0076] Through the force analysis in three-dimensional space, F zi 、F xi 、F yi ,θ i1 ,θ i2 They are respectively the component forces in each direction or the angle between two forces. In this embodiment, i=1,…,8.

[0077] The actual thrust at any time is: F z =F z1 +F z2 +……+F zi . F xi

[0078] The actual lateral force value at any time is: F x = cosθ 11 F x1 +cosθ 12 F y1 ++cosθ 21 F x2 +cosθ 22 F y2 ……+cosθ i1 F xi +cosθ i2 F yi .

[0079] The actual longitudinal force value at any time is: F y = sinθ 11 F x1 +sinθ 12 F y1 ++sinθ 21 F x2 +sinθ 22 F y2 ……+sinθ i1 F xi +sinθ i2 F yi .

[0080] The actual torque at any time is: M = (F x1 +F x2 +……+F xi )L; L is the distance from the center of the sensor to the center of the balance.

[0081] According to the above formula, the real-time thrust, lateral force value, longitudinal force value, torque and other parameters under each working condition at each moment can be obtained through software calculation.

Claims

1. A three-axis force measurement balance, characterized in that: It comprises a column (19), one end face of the column (19) is connected to the object to be measured, and the other end face is connected to a fixed object; each side face of the column (19) is evenly provided with a plurality of groups of force sensor strain patches (20); Each group of force sensor strain patches (20) comprises an axial strain patch (201) and a radial strain patch (202); the axial strain patch (201) is arranged on the side of the column (19) and its length direction is parallel to the axial direction of the column; the radial strain patch (202) is arranged on the side of the column (19) and its length direction is perpendicular to the axial direction of the column; and there is a gap between the axial strain patch (201) and the radial strain patch (202).

2. A three-axis force measurement balance according to claim 1, characterized in that: The force sensor strain patches (20) arranged on each side of the column (19) are three groups or two groups.

3. A three-axis force measurement balance according to claim 2, characterized in that: Three groups of the force sensor strain patches (20) are respectively arranged at the two ends and the middle of the column (19); or two groups of the force sensor sensing patches (20) are respectively arranged at the two ends of the column (19).

4. A three-axis force measurement unit, characterized in that: It comprises a three-axis force measuring balance as claimed in any one of claims 1 to 3, a base (15), a shell (16) and an upper cover (17); The shell (16) is a hollow columnar structure; the base (15) and the shell (16) are fixedly connected to form a cavity; and the upper cover (17) is arranged at the opening of the cavity; A plurality of the three-axis force measurement balances are vertically placed in the cavity, and the upper end surface of the column (19) is connected to the lower end surface of the upper cover (17), and the lower end surface of the column (19) is connected to the upper end surface of the base (15); The upper end surface of the upper cover body (17) is used for placing the test piece.

5. A three-axis force measurement unit according to claim 4, characterized in that: There are four three-axis force measuring balances, which are vertically and evenly placed in the cavity; and the shell (16) is a hollow cylindrical structure.

6. A three-axis force measurement structure, characterized in that: It comprises a second upper base plate (24), a second lower base plate (25) and a three-axis force measuring device; The three-axis force measurement device comprises a plurality of three-axis force measurement units as claimed in claim 4 or 5; The upper end surface of the upper cover (17) of the three-axis force measurement unit is connected to the lower end surface of the second upper base plate (24), and the lower end surface of the base (15) of the three-axis force measurement unit is connected to the upper end surface of the second lower base plate (25). The second upper base plate (24) and the second lower base plate (25) are annular structures with the same structure; Multiple three-axis force measurement units are evenly distributed along the circumference; The upper end surface of the second upper base plate (24) is used for placing the test piece.

7. The three-axis force measurement structure according to claim 6, characterized in that: It also includes an axial force measuring device, the upper surface of which is connected to the lower surface of the second lower base plate (25), and the axial force measuring device includes a first upper base plate (13), a first lower base plate (14), and a plurality of axial force measuring units evenly distributed between the first upper base plate (13) and the first lower base plate (14); the upper end surface of the first upper base plate (13) is connected to the lower surface of the second lower base plate (25); The axial force measuring unit comprises a limit device (11), a force conducting steel ball (6), an axial force sensing unit (7), a limit nut (5), a locking nut (26) and at least two bolts (3), wherein the limit nut (5) and the locking nut (26) correspond to the bolts (3) in a one-to-one manner; The first upper base plate (13) is provided with bolt through holes (1) whose number is the same as the number of the bolts (3); the bolt through holes (1) are rectangular holes or waist-shaped holes and are arranged along the radial direction of the first upper base plate (13); the tail of the bolt (3) passes through the bolt through hole (1), the limit nut (5) and the locking nut (26) in sequence and is then fixedly connected to the first lower base plate (14); The locking nut (26) is used to fix the tail of the bolt (3) on the first lower base plate (14); The limiting device (11) is connected to the lower surface of the first upper base plate (13), and a groove with a semicircular cross section is provided on its lower end surface, the extension direction of the groove is consistent with the extension direction of the bolt through hole (1), and the radius of the groove cross section is greater than the radius of the force conducting steel ball (6); The axial force sensing unit (7) is connected to the upper surface of the first lower base plate (14); The axial force conducting steel ball (6) is located between the limiting device (11) and the axial force sensing unit (7), and the axial force conducting steel ball (6) is in point contact with the groove and the sensitive surface of the axial force sensing unit (7) respectively; When the axial force sensing unit (7) outputs a maximum value, the distance between the limit nut (5) and the first upper base plate (13) is 0; The first upper base plate (13) can move relatively along the axial direction of the bolt (3).

8. The three-axis force measurement structure according to claim 7, characterized in that: The first upper base plate (13) and the first lower base plate (14) are annular structures with the same structure; A fixing threaded hole (10) is provided on the upper surface of the first lower base plate (14), and the axial force sensing unit (7) is connected to the upper surface of the first lower base plate (14) via the fixing threaded hole (10).

9. A three-axis force measurement method, characterized in that: Based on the force measurement structure described in claim 6, the steps are as follows: Step 1, calibrating a three-axis force measurement device; Step 2, installing the three-axis force measurement device between the engine test bench and the engine test frame; Step 3, obtaining the actual lateral force value, longitudinal force value and / or actual torque at any time through force analysis.

10. A three-axis force measurement method, characterized in that: Based on the force measurement structure described in claim 7, the steps are as follows: Step 1, calibrating the axial force measuring device and the three-axis force measuring device respectively; Step 2, connecting the axial force measuring device and the three-axis force measuring device and installing them between the engine test bench and the engine test frame; Step 3, obtaining the actual lateral force value, longitudinal force value, actual torque and / or axial force at any time through force analysis.

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