A three-component strain balance structure and multi-balance assembly measurement method

Abstract

A three-component strain balance structure and a multi-balance assembly measurement method belong to the technical field of measurement equipment. The present invention is to solve the problem of inaccurate measurement caused by over-constraint caused by the connection of multiple multi-component balances. The strain balance structure includes a balance body, which cooperates with the outer ring of a ball joint bearing. The bolt member includes a screw rod portion and a smooth rod portion coaxially connected to each other. The bottom of the smooth rod portion is provided with a flange structure, and the smooth rod portion cooperates with the inner hole of the ball joint bearing. The screw rod portion is threadedly connected to the upper connecting piece. The upper connecting piece, the inner ring ball sleeve of the ball joint bearing and the flange structure are abutted and fastened in turn. The upper end face of the upper connecting piece is a flange plane, and the flange plane is provided with a plurality of transparent screw holes and a plurality of positioning pin holes. The universal flexible connection of the balance structure is realized by the ball joint bearing, which can eliminate the connection stress of the multi-balance connection and realize the accurate measurement of the multi-component force of the multi-balance combination.

Description

Technical Field

[0001] The invention belongs to the technical field of measuring equipment, and in particular relates to a three-component strain balance structure and a multi-balance assembly measurement method. Background Art

[0002] Wind tunnel balance is an important measuring device for measuring aircraft wind tunnel tests. It is used to measure the aerodynamic load of aircraft to guide the design optimization of aircraft. According to the working principle, it can be divided into mechanical balance, fiber optic balance, piezoelectric balance, etc. At present, the most commonly used is the strain balance, which adopts the principle of strain electrical measurement, pastes strain gauges on sensitive elements, forms an electric bridge, and converts the strain of the material body under load deformation into an electrical signal for measurement. With the continuous expansion of applications, the combined application of multiple balances is becoming more and more extensive, such as assembled multi-dimensional force measurement platforms or combined multi-component balances. Due to the over-constrained state of the combined connection of multiple balances, the installation stress affects the measurement accuracy of the balance. The current method to solve the measurement problem of such an over-constrained connection system is to perform overall load calibration on the connected system. This method requires the construction of a large overall calibration equipment, which increases the cost and is time-consuming and labor-intensive. Summary of the invention

[0003] The purpose of the present invention is to provide a three-component strain gauge balance structure and a multi-balance assembly measurement method to solve the problem of inaccurate measurement caused by over-constraints in the connection of multiple multi-component balances when multiple balances are combined and applied. The technical solution adopted by the present invention is as follows:

[0004] A three-component strain balance structure comprises an upper connecting member, a bolt member, a bearing end cover, a ball joint bearing and a balance body;

[0005] The balance body includes a connecting beam and a shearing beam arranged up and down, the connecting beam and the shearing beam are both cylindrical components, the connecting beam and the shearing beam are coaxially arranged, the connecting beam and the shearing beam are connected by four measuring elements, the four measuring elements are evenly distributed around the circumference of the axis of the connecting beam, and the four measuring elements are respectively located at the front side, the rear side, the left side and the right side of the balance body, the upper end surface of the connecting beam is provided with a stepped groove located in the center and a first annular sealing groove sleeved on the outer periphery of the stepped groove, a first sealing ring is provided in the first annular sealing groove, and the shearing beam includes a plurality of measuring elements arranged from top to bottom according to the embodiment of the present invention. The first column beam section, the second column beam section and the third column beam section are arranged in a sequential manner, an upper gap is arranged between the right part of the first column beam section and the right part of the second column beam, a lower gap is arranged between the left part of the second column beam section and the left part of the third column beam section, the front side and the rear side of the second column beam section are symmetrically milled with process planes, a trapezoidal groove is processed on the process plane, a force measuring thin wall is formed between the bottom surfaces of the two trapezoidal grooves, a shoulder flange is arranged on the third column beam section, a second annular sealing groove is processed on the upper end surface of the shoulder flange, and a second sealing ring is arranged in the second annular sealing groove;

[0006] A bellows is sleeved on the outer periphery of the balance body, a working gap is provided between the bellows and the measuring element, the upper end of the bellows is connected to the outer edge of the upper end ring plate, the lower end of the bellows is connected to the outer edge of the lower end ring plate, the lower end ring plate and the shaft shoulder flange are coaxially sealed and connected up and down through the second sealing ring, the bearing end cover, the upper end ring plate and the connecting beam are coaxially connected from top to bottom in sequence, the upper end ring plate and the connecting beam are sealed and matched through the first sealing ring, the bearing end cover is provided with a stepped hole, the upper end of the ball hinge bearing is matched with the stop of the stepped hole, and the lower end of the ball hinge bearing is matched with the stop of the stepped groove;

[0007] The bolt component includes a screw portion and a smooth rod portion which are coaxially connected upper and lower. A flange structure is provided at the bottom of the smooth rod portion. The smooth rod portion cooperates with the inner hole of the ball joint bearing. The screw portion is threadedly connected to the upper connecting piece. The upper connecting piece, the inner ring ball sleeve of the ball joint bearing and the flange structure are abutted and fastened in sequence. The upper end face of the upper connecting piece is a flange plane, and a plurality of transparent screw holes and a plurality of positioning pin holes are provided on the flange plane.

[0008] Furthermore, a hexagonal countersunk hole is provided on the lower end surface of the polished rod portion.

[0009] Furthermore, a transparent bus threading hole is processed radially on the front side of the lower end ring plate.

[0010] Furthermore, the two trapezoidal sinks are connected through two branch line threading holes respectively.

[0011] Furthermore, the measuring element is a square column component.

[0012] Furthermore, assuming that the left-right direction is the transverse direction, the front-back direction is the lateral direction, the up-down direction is the longitudinal direction, the cross-sectional side length of the measuring element is b, and the length of the measuring element is L, then the microstrain Δ of the measuring element under the transverse force is Z and microstrain Δ under lateral force X Calculated by the following formula:

[0013]

[0014]

[0015] Where: F Z is the lateral force, in N; F X is the lateral force, in N; E is the elastic modulus, in MPa;

[0016] b and L satisfy the microstrain Δ when the measuring element on the left and the measuring element on the right are subjected to lateral force Z Microstrain Δ between 150με and 700με when the measuring element at the front and the measuring element at the rear are subjected to lateral force X Between 150με and 700με;

[0017] Assuming the thickness of the force measuring thin wall is h, the micro strain Δ of the force measuring thin wall under the action of longitudinal force is Y Calculated by the following formula:

[0018]

[0019] Where: F Y is the longitudinal force, in N; S Z is the static moment of the left and right midplanes of the second column-beam segment about the neutral axis, in m 3 ;I Z is the moment of inertia of the left and right midplanes of the second column-beam segment about the neutral axis, in m 4 ;

[0020] h satisfies the micro strain Δ when the force measuring thin wall is subjected to longitudinal force Y Between 150με and 700με.

[0021] The present invention also provides a multi-balance assembly measurement method, which is implemented based on the above-mentioned three-component strain balance structure and includes the following steps:

[0022] Step 1: Paste the first strain gauge and the second strain gauge on the measuring element on the left side of the three-component strain balance structure, paste the third strain gauge and the fourth strain gauge on the measuring element on the right side, paste the fifth strain gauge and the seventh strain gauge on the measuring element on the front side, paste the sixth strain gauge and the eighth strain gauge on the measuring element on the rear side, paste the ninth strain gauge and the eleventh strain gauge on the bottom surface of the trapezoidal sink groove on the front side, paste the tenth strain gauge and the twelfth strain gauge on the bottom surface of the trapezoidal sink groove on the rear side, and the first strain gauge, the second strain gauge, the fourth strain gauge and the third strain gauge are electrically connected in sequence to form a Wheatstone bridge, which is named U 1 The fifth strain gauge, the sixth strain gauge, the eighth strain gauge and the seventh strain gauge are electrically connected in sequence to form a Wheatstone bridge, which is named U 2 The ninth strain gauge, the eleventh strain gauge, the tenth strain gauge and the twelfth strain gauge are electrically connected in sequence to form a Wheatstone bridge, which is named U 3 ;

[0023] Step 2: According to the measurement requirements, select a number of the three-component strain balance structures, N is an integer ≥ 2, connect the bridges to the three-component strain balance structures one by one according to the method in step 1, and calibrate them to obtain the corresponding relationship coefficient between the load and the measurement signal output of each three-component strain balance structure;

[0024] Step 3: Select a rectangular force measuring platform plate, and connect the flange planes of several three-component strain balance structures to the lower end surface of the force measuring platform plate respectively;

[0025] Step 4: Set the center of the rectangular force platform plate as the origin, and establish a coordinate system. The positive direction of the X-axis extends backward through the origin, the positive direction of the Z-axis extends to the left through the origin, and the positive direction of the Y-axis extends upward through the origin. Mark the area located in the positive direction of the Z-axis and the positive direction of the X-axis as the first area, the area located in the negative direction of the Z-axis and the positive direction of the X-axis as the second area, the area located in the positive direction of the Z-axis and the negative direction of the X-axis as the third area, and the area located in the negative direction of the Z-axis and the negative direction of the X-axis as the fourth area;

[0026] If there are n three-component strain balance structures in the first region, and n is an integer ≥ 0, the Z-axis distances between the axis centers of the n three-component strain balance structures in the first region and the origin are marked as L Z11 , L Z12 ...L Z1n The X-axis distances between the axis centers of the n three-component strain balance structures and the origin are marked as L X11 , L X12 ...L X1n ;

[0027] If there are m three-component strain balance structures in the second region, where m is an integer ≥ 0, the Z-axis distances between the axes of the m three-component strain balance structures in the second region and the origin are marked as L Z21 , L Z22 ...L Z2m The X-axis distances between the axes of the m three-component strain balance structures and the origin are marked as L X21 , L X22 ...L X2m ;

[0028] If there are j three-component strain balance structures in the third region, and j is an integer ≥ 0, the Z-axial distances between the axes of the j three-component strain balance structures in the third region and the origin are marked as L Z31 , L Z32 ...L Z3j The X-axis distances between the axes of the j three-component strain balance structures and the origin are marked as L X31 , L X32 ...L X3j ;

[0029] If there are k three-component strain balance structures in the fourth region, k is an integer ≥ 0, then the Z-axis distances between the axes of the k three-component strain balance structures in the fourth region and the origin are marked as L Z41 , L Z42 ...L Z4k The X-axis distances between the axes of the k three-component strain balance structures and the origin are marked as L X41 , L X42 ...LX4k ;

[0030] The calculation formula for the six-component load on the rectangular force measuring platform plate is as follows:

[0031] Y=Y 11 +Y 12 +……+Y 1n +Y 21 +Y 22 +……+Y 2m +Y 31 +Y 32 +……+Y 3j +Y 41 +Y 42 +……+Y 4k

[0032] X=X 11 +X 12 +……+X 1n +X 21 +X 22 +……+X 2m +X 31 +X 32 +……+X 3j +X 41 +X 42 +……+X 4k

[0033] Z=Z 11 +Z 12 +……+Z 1n +Z 21 +Z 22 +……+Z 2m +Z 31 +Z 32 +……+Z 3j +Z 41 +Z 42 +……+Z 4k

[0034] M z =Y 11 *L X11 +Y 12 *L X12 +……+Y 1n *L X1n +Y 21 *L X21 +Y 22 *L X22 +……

[0035] +Y 2m *L X2m -Y 31 *L X31 -Y32 *L X32 -……-Y 3j *L X3j -Y 41 *L X41 -Y 42 *L X42 -……-Y 4k *L X4k

[0036] M x =Y 11 *L Z11 +Y 12 *L Z12 +……+Y 1n *L Z1n -Y 21 *L Z21 -Y 22 *L Z22 -……

[0037] -Y 2m *L Z2m +Y 31 *L Z31 +Y 32 *L Z32 +……+Y 3j *L Z3j -Y 41 *L Z41 -Y 42 *L Z42 -……-Y 4k *L Z4k

[0038] M y =-X 11 *L Z11 -X 12 *L Z12 -……-X 1n *L Z1n +X 21 *L Z21 +X 22 *L Z22 +……

[0039] +X 2m *L Z2m -X 31 *L Z31 -X 32 *L Z32 -……-X 3j *L Z3j +X 41 *L Z41 +X 42 *L Z42 +……

[0040] +X 4k *L Z4k +Z 11 *L X11 +Z 12 *L X12 +……+Z 1n *L X1n +Z 21 *L X21 +Z 22 *L X22 +……

[0041] +Z 2m *L X2m -Z 31 *L X31 -Z 32 *L X32 -……-Z 3j *L X3j -Z 41 *L X41 -Z 42 *L X42 -……-Z 4k *L X4k

[0042] Among them, Y is the longitudinal force on the rectangular force measuring platform plate, X is the lateral force on the rectangular force measuring platform plate, Z is the transverse force on the rectangular force measuring platform plate, M z M is the moment of force on the rectangular force platform plate around the Z axis. x is the moment of force on the rectangular force platform plate around the X axis, M y is the moment of force on the rectangular force platform plate around the Y axis;

[0043] Y 11 , Y 12 ,……,Y 1n is the longitudinal force on the n three-component strain balance structures in the first region, Y 21 , Y 22 ,……,Y 2m is the longitudinal force on the m three-component strain balance structures in the second region, Y 31 , Y 32 ,……,Y 3j is the longitudinal force on the jth three-component strain balance structure in the third region, Y 41 , Y 42 ,……,Y 4k are the longitudinal forces respectively exerted on the k three-component strain balance structures in the fourth region;

[0044] X 11 , X 12 ,……,X1n is the lateral force on the n three-component strain balance structures in the first region, X 21 , X 22 ,……,X 2m is the lateral force on the m three-component strain balance structures in the second region, X 31 , X 32 ,……,X 3j is the lateral force on the j-th three-component strain balance structure in the third region, X 41 , X 42 ,……,X 4k is the lateral force respectively exerted on the k three-component strain balance structures in the fourth region;

[0045] Z 11 , Z 12 ,……,Z 1n is the lateral force on the n three-component strain balance structures in the first region, Z 21 , Z 22 ,……,Z 2m is the lateral force on the m three-component strain balance structures in the second region, Z 31 , Z 32 ,……,Z 3j is the lateral force on the j three-component strain balance structures in the third region, Z 41 , Z 42 ,……,Z 4k is the lateral force respectively applied to the k three-component strain balance structures in the fourth region, and the lateral force applied to each of the three-component strain balance structures is expressed by U 1 The pressure change signal measured by the bridge is calculated, and the lateral force is calculated by U 2 The pressure change signal measured by the bridge is calculated, and the longitudinal force is calculated by U 3 The voltage change signal measured by the bridge is calculated.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The three-component strain balance structure proposed in the present invention is connected to the balance body through a ball joint bearing, so that the strain balance structure has a universal hinge and is suitable for combined assembly and use. When the four measuring elements are subjected to lateral force or lateral force load, the corresponding measuring elements undergo "S" shape deformation, and the three-component load measurement is performed through the combination of deformable measuring elements and shear beams. The universal flexible connection of the balance structure is achieved through the ball joint bearing, which can eliminate the connection stress of multiple balance connections and realize accurate measurement of multi-component forces of the multi-balance combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1It is a front cross-sectional view of the balance structure of the present invention;

[0049] Figure 2 is an axonometric view of the balance structure of the present invention;

[0050] Figure 3 It is a front view of the balance structure of the present invention;

[0051] Figure 4 yes Figure 1 AA section view;

[0052] Figure 5 It is an axonometric view of the balance itself;

[0053] Figure 6 It is the main view of the balance body;

[0054] Figure 7 It is the left view of the balance body;

[0055] Figure 8 yes Figure 6 BB cross-sectional view;

[0056] Fig. 9 yes Figure 7 CC section view;

[0057] Fig.10 It is a structural schematic diagram of the upper end ring plate;

[0058] Fig.11 It is a structural schematic diagram of a bolt component;

[0059] Fig.12 Schematic diagram of the pasting position of each strain gauge in the method of the present invention;

[0060] Fig.13 It is the U1 bridge diagram of the method of the present invention;

[0061] Fig.14 It is the U2 bridge diagram of the method of the present invention;

[0062] Fig.15 It is the U3 bridge diagram of the method of the present invention;

[0063] Fig.16 It is a position coordinate diagram of several strain balance structures of the method of the present invention.

[0064] In the figure, 1. balance body, 11. connecting beam, 111. stepped sink, 112. first annular sealing groove, 12. measuring element, 13. shear beam, 131. first column beam section, 132. second column beam section, 133. third column beam section, 134. upper gap, 135. lower gap, 136. process plane, 137. trapezoidal sink, 138. straight line threading hole, 139. force measuring thin wall, 14. shoulder flange, 141. second annular sealing groove, 2. bellows, 21. upper end ring plate, 22. lower end ring plate, 221. bus threading hole, 3. Bearing end cover, 4. Upper connecting piece, 41. Flange plane, 5. Bolt, 51. Screw part, 52. Bare rod part, 53. Flange structure, 54. Hexagon socket countersunk hole, 6. Ball joint bearing, 71. First strain gauge, 72. Second strain gauge, 73. Third strain gauge, 74. Fourth strain gauge, 75. Fifth strain gauge, 76. Sixth strain gauge, 77. Seventh strain gauge, 78. Eighth strain gauge, 79. Ninth strain gauge, 710. Tenth strain gauge, 711. Eleventh strain gauge, 712. Twelfth strain gauge, 8. Rectangular force measuring platform plate. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0066] The connection mentioned in the present invention is divided into fixed connection and detachable connection. The fixed connection is a non-detachable connection including but not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection and welding connection. The detachable connection includes but not limited to conventional detachable methods such as bolt connection, snap connection, pin connection and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can be found in the existing connection methods to achieve the function, and those skilled in the art can choose according to their needs. For example: welding connection is selected for fixed connection, and bolt connection is selected for detachable connection.

[0067] The present invention will be further described in detail below in conjunction with the accompanying drawings. The following embodiments are provided to explain the present invention, but the present invention is not limited to the following embodiments.

[0068] Embodiment 1: Figures 1 to 11 As shown, a three-component strain balance structure includes an upper connecting member 4, a bolt member 5, a bearing end cover 3, a ball joint bearing 6 and a balance body 1;

[0069] The balance body 1 includes a connecting beam 11 and a shearing beam 13 arranged up and down, the connecting beam 11 and the shearing beam 13 are both cylindrical components, the connecting beam 11 and the shearing beam 13 are coaxially arranged, the connecting beam 11 and the shearing beam 13 are connected by four measuring elements 12, the four measuring elements 12 are evenly distributed around the circumference of the connecting beam 11, and the four measuring elements 12 are respectively located at the front side, the rear side, the left side and the right side of the balance body 1, the upper end surface of the connecting beam 11 is provided with a stepped groove 111 located in the center and a first annular sealing groove 112 sleeved on the outer periphery of the stepped groove 111, a first sealing ring is provided in the first annular sealing groove 112, and the shearing beam 13 includes a first A column beam section 131, a second column beam section 132 and a third column beam section 133, an upper gap 134 is provided between the right part of the first column beam section 131 and the right part of the second column beam, a lower gap 135 is provided between the left part of the second column beam section 132 and the left part of the third column beam section 133, a process plane 136 is symmetrically milled on the front and rear sides of the second column beam section 132, a trapezoidal recessed groove 137 is processed on the process plane 136, a force measuring thin wall 139 is formed between the bottom surfaces of the two trapezoidal recessed grooves 137, a shoulder flange 14 is provided on the third column beam section 133, a second annular sealing groove 141 is processed on the upper end surface of the shoulder flange 14, and a second sealing ring is provided in the second annular sealing groove 141;

[0070] The outer periphery of the balance body 1 is sleeved with a bellows 2, a working gap is provided between the bellows 2 and the measuring element 12, the upper end of the bellows 2 is connected to the outer edge of the upper end ring plate 21, the lower end of the bellows 2 is connected to the outer edge of the lower end ring plate 22, the lower end ring plate 22 is coaxially sealed with the shaft shoulder flange 14 through the second sealing ring, the bearing end cover 3, the upper end ring plate 21 and the connecting beam 11 are coaxially connected from top to bottom, the upper end ring plate 21 and the connecting beam 11 are sealed and matched through the first sealing ring, the bearing end cover 3 is provided with a stepped hole, the upper end of the ball hinge bearing 6 is matched with the stop of the stepped hole, and the lower end of the ball hinge bearing 6 is matched with the stop of the stepped sink groove 111;

[0071] The bolt member 5 includes a screw portion 51 and a smooth rod portion 52 which are coaxially connected to each other. A flange structure 53 is provided at the bottom of the smooth rod portion 52. The smooth rod portion 52 cooperates with the inner hole of the ball joint bearing 6. The screw portion 51 is threadedly connected to the upper connecting member 4. The upper connecting member 4, the inner ring ball sleeve of the ball joint bearing 6 and the flange structure 53 are abutted and fastened in sequence. The upper end face of the upper connecting member 4 is a flange plane 41, and a plurality of transparent screw holes and a plurality of positioning pin holes are provided on the flange plane 41.

[0072] A hexagonal counterbore 54 is provided on the lower end surface of the polished rod portion 52 .

[0073] A transparent bus threading hole 221 is processed radially on the front side of the lower end ring plate 22 .

[0074] The two trapezoidal sinks 137 are connected through two branch line threading holes 138 respectively.

[0075] The measuring element 12 is a square column member.

[0076] Assuming that the left-right direction is the transverse direction, the front-back direction is the lateral direction, and the up-down direction is the longitudinal direction, the cross-sectional side length of the measuring element 12 is b, and the length of the measuring element 12 is L, then the microstrain Δ of the measuring element 12 under the transverse force is Z and microstrain Δ under lateral force X Calculated by the following formula:

[0077]

[0078]

[0079] Where: F Z is the lateral force, in N; F X is the lateral force, in N; E is the elastic modulus, in MPa;

[0080] b and L satisfy the micro strain Δ when the measuring element 12 on the left and the measuring element 12 on the right are subjected to the lateral force. Z Between 150 με and 700 με, the micro strain Δ of the measuring element 12 located at the front side and the measuring element 12 located at the rear side when subjected to the lateral force X Between 150με and 700με;

[0081] Assuming the thickness of the force measuring thin wall 139 is h, the micro strain Δ of the force measuring thin wall 139 under the longitudinal force is Y Calculated by the following formula:

[0082]

[0083] Where: F Y is the longitudinal force, in N; S Z is the static moment of the left and right midplanes of the second column beam section 132 about the neutral axis, in m 3 ;I Z is the moment of inertia of the left and right midplanes of the second column beam segment 132 about the neutral axis, in m 4 ;

[0084] h satisfies the micro strain Δ when the force measuring thin wall 139 is subjected to longitudinal force Y Between 150με and 700με.

[0085] The outer ring of the ball joint bearing 6 is fixed by a stopper, and the inner ring ball sleeve can rotate arbitrarily around the center. The upper end ring plate 21 is provided with four countersunk holes and four threaded blind holes, and the four countersunk holes are used to be connected to the connecting beam 11 through cylindrical countersunk screws, and the four threaded blind holes are used to be connected to the bearing end cover 3 through screws. The bellows 2 can be used for heat insulation to provide a closed environment for the balance body 1. At the same time, the bellows 2 has the ability to deform and will not affect the measurement of the balance body 1. The lower end ring plate 22 and the shoulder flange 14 are detachably connected by screws, and the lower end face of the third column beam section 133 is provided with screw holes and locating pin holes for connecting with other components.

[0086] The three-component strain balance structure proposed in the present invention is connected to the balance body 1 through a ball joint bearing 6, so that the strain balance structure has a universal hinge and is suitable for combined assembly and use. When the four measuring elements 12 are subjected to lateral force or lateral force load, the corresponding measuring elements 12 undergo "S" shape deformation, and the three-component load measurement is performed through the combination of the deformable measuring elements 12 and the shear beam 13. The universal flexible connection of the balance structure is achieved through the ball joint bearing 6, which can eliminate the connection stress of multiple balance connections and realize accurate measurement of multi-component forces of the multi-balance combination.

[0087] Embodiment 2: Figures 12 to 16 As shown, a multi-balance assembly measurement method is implemented based on a three-component strain balance structure described in Example 1, and includes the following steps:

[0088] Step 1: Paste the first strain gauge 71 and the second strain gauge 72 on the measuring element 12 on the left side of the three-component strain balance structure, paste the third strain gauge 73 and the fourth strain gauge 74 on the measuring element 12 on the right side, paste the fifth strain gauge 75 and the seventh strain gauge 77 on the measuring element 12 on the front side, paste the sixth strain gauge 76 and the eighth strain gauge 78 on the measuring element 12 on the rear side, paste the ninth strain gauge 79 and the eleventh strain gauge 711 on the bottom surface of the trapezoidal sink 137 on the front side, paste the tenth strain gauge 710 and the twelfth strain gauge 712 on the bottom surface of the trapezoidal sink 137 on the rear side, and the first strain gauge 71, the second strain gauge 72, the fourth strain gauge 74 and the third strain gauge 73 are electrically connected in sequence to form a Wheatstone bridge, which is named U 1 The fifth strain gauge 75, the sixth strain gauge 76, the eighth strain gauge 78 and the seventh strain gauge 77 are electrically connected in sequence to form a Wheatstone bridge, which is named U 2 The ninth strain gauge 79, the eleventh strain gauge 711, the tenth strain gauge 710 and the twelfth strain gauge 712 are electrically connected in sequence to form a Wheatstone bridge, and are named U 3 ;

[0089] Step 2: According to the measurement requirements, select a number of the three-component strain balance structures, N is an integer ≥ 2, connect the bridges to the three-component strain balance structures one by one according to the method in step 1, and calibrate them to obtain the corresponding relationship coefficient between the load and the measurement signal output of each three-component strain balance structure;

[0090] Step 3: Select a rectangular force measuring platform plate 8, and connect the flange planes 41 of the three-component strain balance structures to the lower end surface of the force measuring platform plate respectively;

[0091] Step 4: Set the center of the rectangular force measuring platform plate 8 as the origin, and establish a coordinate system. The positive direction of the X-axis extends backward through the origin, the positive direction of the Z-axis extends to the left through the origin, and the positive direction of the Y-axis extends upward through the origin. Mark the area located in the positive direction of the Z-axis and the positive direction of the X-axis as the first area, the area located in the negative direction of the Z-axis and the positive direction of the X-axis as the second area, the area located in the positive direction of the Z-axis and the negative direction of the X-axis as the third area, and the area located in the negative direction of the Z-axis and the negative direction of the X-axis as the fourth area;

[0092] If there are n three-component strain balance structures in the first region, and n is an integer ≥ 0, the Z-axial distances between the axes of the n three-component strain balance structures in the first region and the origin are marked as L Z11 , L Z12 ...L Z1n The X-axis distances between the axis centers of the n three-component strain balance structures and the origin are marked as L X11 , L X12 ...L X1n ;

[0093] If there are m three-component strain balance structures in the second region, and m is an integer ≥ 0, the Z-axis distances between the axes of the m three-component strain balance structures in the second region and the origin are marked as L Z21 , L Z22 ...L Z2m The X-axis distances between the axes of the m three-component strain balance structures and the origin are marked as L X21 , L X22 ...L X2m ;

[0094] If there are j three-component strain balance structures in the third region, and j is an integer ≥ 0, the Z-axial distances between the axes of the j three-component strain balance structures in the third region and the origin are marked as L Z31 , L Z32 ...L Z3j The X-axis distances between the axes of the j three-component strain balance structures and the origin are marked as L X31 , L X32 ...LX3j ;

[0095] If there are k three-component strain balance structures in the fourth region, k is an integer ≥ 0, then the Z-axis distances between the axes of the k three-component strain balance structures in the fourth region and the origin are marked as L Z41 , L Z42 ...L Z4k The X-axis distances between the axes of the k three-component strain balance structures and the origin are marked as L X41 , L X42 ...L X4k ;

[0096] The calculation formula of the six-component load on the rectangular force measuring platform plate 8 is as follows:

[0097] Y=Y 11 +Y 12 +……+Y 1n +Y 21 +Y 22 +……+Y 2m +Y 31 +Y 32 +……+Y 3j +Y 41 +Y 42 +……+Y 4k

[0098] X=X 11 +X 12 +……+X 1n +X 21 +X 22 +……+X 2m +X 31 +X 32 +……+X 3j +X 41 +X 42 +……+X 4k

[0099] Z=Z 11 +Z 12 +……+Z 1n +Z 21 +Z 22 +……+Z 2m +Z 31 +Z 32 +……+Z 3j +Z 41 +Z 42 +……+Z 4k

[0100] M z =Y 11 *L X11+Y 12 *L X12 +……+Y 1n *L X1n +Y 21 *L X21 +Y 22 *L X22 +……

[0101] +Y 2m *L X2m -Y 31 *L X31 -Y 32 *L X32 -……-Y 3j *L X3j -Y 41 *L X41 -Y 42 *L X42 -……-Y 4k *L X4k

[0102] M x =Y 11 *L Z11 +Y 12 *L Z12 +……+Y 1n *L Z1n -Y 21 *L Z21 -Y 22 *L Z22 -……

[0103] -Y 2m *L Z2m +Y 31 *L Z31 +Y 32 *L Z32 +……+Y 3j *L Z3j -Y 41 *L Z41 -Y 42 *L Z42 -……-Y 4k *L Z4k

[0104] M y =-X 11 *L Z11 -X 12 *L Z12 -……-X 1n *L Z1n +X 21 *L Z21 +X 22 *L Z22+……

[0105] +X 2m *L Z2m -X 31 *L Z31 -X 32 *L Z32 -……-X 3j *L Z3j +X 41 *L Z41 +X 42 *L Z42 +……

[0106] +X 4k *L Z4k +Z 11 *L X11 +Z 12 *L X12 +……+Z 1n *L X1n +Z 21 *L X21 +Z 22 *L X22 +……

[0107] +Z 2m *L X2m -Z 31 *L X31 -Z 32 *L X32 -……-Z 3j *L X3j -Z 41 *L X41 -Z 42 *L X42 -……-Z 4k *L X4k

[0108] Wherein, Y is the longitudinal force on the rectangular force measuring platform plate 8, X is the lateral force on the rectangular force measuring platform plate 8, Z is the transverse force on the rectangular force measuring platform plate 8, M z is the moment of force on the rectangular force platform plate 8 around the Z axis, M x is the moment of force on the rectangular force platform plate 8 around the X axis, M y is the moment of force on the rectangular force platform plate 8 about the Y axis;

[0109] Y 11 , Y 12 ,……,Y 1n is the longitudinal force on the n three-component strain balance structures in the first region, Y 21 , Y 22 ,……,Y 2mis the longitudinal force on the m three-component strain balance structures in the second region, Y 31 , Y 32 ,……,Y 3j is the longitudinal force on the jth three-component strain balance structure in the third region, Y 41 , Y 42 ,……,Y 4k are the longitudinal forces respectively exerted on the k three-component strain balance structures in the fourth region;

[0110] X 11 , X 12 ,……,X 1n is the lateral force on the n three-component strain balance structures in the first region, X 21 , X 22 ,……,X 2m is the lateral force on the m three-component strain balance structures in the second region, X 31 , X 32 ,……,X 3j is the lateral force on the j-th three-component strain balance structure in the third region, X 41 , X 42 ,……,X 4k is the lateral force respectively exerted on the k three-component strain balance structures in the fourth region;

[0111] Z 11 , Z 12 ,……,Z 1n is the lateral force on the n three-component strain balance structures in the first region, Z 21 , Z 22 ,……,Z 2m is the lateral force on the m three-component strain balance structures in the second region, Z 31 , Z 32 ,……,Z 3j is the lateral force on the j three-component strain balance structures in the third region, Z 41 , Z 42 ,……,Z 4k is the lateral force respectively applied to the k three-component strain balance structures in the fourth region, and the lateral force applied to each of the three-component strain balance structures is expressed by U 1 The pressure change signal measured by the bridge is calculated, and the lateral force is calculated by U 2 The pressure change signal measured by the bridge is calculated, and the longitudinal force is calculated by U 3 The voltage change signal measured by the bridge is calculated.

[0112] The above embodiments are merely exemplary descriptions of the present invention and do not limit its protection scope. Those skilled in the art may also make partial changes thereto, which are within the protection scope of the present invention as long as they do not exceed the spirit of the present invention.

Claims

1. A three-component strain balance structure, characterized in that: It comprises an upper connecting member (4), a bolt member (5), a bearing end cover (3), a ball joint bearing (6) and a balance body (1); The balance body (1) comprises a connecting beam (11) and a shearing beam (13) arranged in an upper and lower part. The connecting beam (11) and the shearing beam (13) are both cylindrical components. The connecting beam (11) and the shearing beam (13) are arranged coaxially. The connecting beam (11) and the shearing beam (13) are connected via four measuring elements (12). The four measuring elements (12) are evenly distributed around the circumference of the connecting beam (11) with the axis of the connecting beam (11) as the axis. The four measuring elements (12) are respectively located at the front side, the rear side, the left side and the right side of the balance body (1). The upper end surface of the connecting beam (11) is provided with a stepped groove (111) located in the center and a first annular sealing groove (112) sleeved on the outer circumference of the stepped groove (111). A first sealing ring is arranged in the first annular sealing groove (112). The shearing beam (13) comprises first and second measuring elements (12) arranged in sequence from top to bottom. A column beam section (131), a second column beam section (132) and a third column beam section (133); an upper gap (134) is provided between the right part of the first column beam section (131) and the right part of the second column beam; a lower gap (135) is provided between the left part of the second column beam section (132) and the left part of the third column beam section (133); a process plane (136) is symmetrically milled on the front and rear sides of the second column beam section (132); a trapezoidal recessed groove (137) is processed on the process plane (136); a force measuring thin wall (139) is formed between the bottom surfaces of the two trapezoidal recessed grooves (137); a shoulder flange (14) is provided on the third column beam section (133); a second annular sealing groove (141) is processed on the upper end surface of the shoulder flange (14); a second sealing ring is provided in the second annular sealing groove (141); A bellows (2) is sleeved on the outer periphery of the balance body (1), a working gap is provided between the bellows (2) and the measuring element (12), the upper end of the bellows (2) is connected to the outer edge of the upper ring plate (21), the lower end of the bellows (2) is connected to the outer edge of the lower ring plate (22), the lower ring plate (22) and the shaft shoulder flange (14) are coaxially sealed and connected up and down through the second sealing ring, the bearing end cover (3), the upper ring plate (21) and the connecting beam (11) are coaxially connected in sequence from top to bottom, the upper ring plate (21) and the connecting beam (11) are sealed and matched through the first sealing ring, the bearing end cover (3) is provided with a stepped hole, the upper end of the ball hinge bearing (6) is matched with the stop of the stepped hole, and the lower end of the ball hinge bearing (6) is matched with the stop of the stepped groove (111); The bolt member (5) comprises a screw rod portion (51) and a smooth rod portion (52) which are coaxially connected to each other. A flange structure (53) is provided at the bottom of the smooth rod portion (52). The smooth rod portion (52) cooperates with the inner hole of the ball joint bearing (6). The screw rod portion (51) is threadedly connected to the upper connecting member (4). The upper connecting member (4), the inner ring ball sleeve of the ball joint bearing (6) and the flange structure (53) are abutted and fastened in sequence. The upper end face of the upper connecting member (4) is a flange plane (41), and a plurality of through screw holes and a plurality of positioning pin holes are provided on the flange plane (41).

2. A three-component strain balance structure according to claim 1, characterized in that: A hexagonal countersunk hole (54) is provided on the lower end surface of the polished rod portion (52).

3. A three-component strain balance structure according to claim 1, characterized in that: A transparent bus threading hole (221) is processed radially on the front side of the lower end ring plate (22).

4. A three-component strain balance structure according to claim 1, characterized in that: The two trapezoidal sinks (137) are connected through two branch line threading holes (138) respectively.

5. A three-component strain balance structure according to any one of claims 1 to 4, characterized in that: The measuring element (12) is a square column component.

6. A three-component strain balance structure according to claim 5, characterized in that: Assuming that the left-right direction is the transverse direction, the front-back direction is the lateral direction, and the up-down direction is the longitudinal direction, the cross-sectional side length of the measuring element (12) is b, and the length of the measuring element (12) is L, then the microstrain Δ of the measuring element (12) under the action of the transverse force is Z and microstrain Δ under lateral force X Calculated by the following formula: Where: F Z is the lateral force, in N; F X is the lateral force, in N; E is the elastic modulus, in MPa; b and L satisfy the micro strain Δ when the measuring element (12) located on the left and the measuring element (12) located on the right are subjected to the lateral force. Z Between 150 με and 700 με, the micro strain Δ of the measuring element (12) located at the front side and the measuring element (12) located at the rear side when subjected to the lateral force X Between 150με and 700με; Assuming the thickness of the force measuring thin wall (139) is h, the micro strain Δ of the force measuring thin wall (139) under the action of the longitudinal force is Y Calculated by the following formula: Where: F Y is the longitudinal force, in N; S Z is the static moment of the left and right midplanes of the second column beam section (132) about the neutral axis, in m 3 ;I Z is the moment of inertia of the left and right midplanes of the second column beam segment (132) about the neutral axis, in m 4 ; h satisfies the micro strain Δ when the force measuring thin wall (139) is subjected to the longitudinal force Y Between 150με and 700με.

7. A multi-balance assembly measurement method, implemented by relying on a three-component strain balance structure as claimed in claim 6, characterized in that: The following steps are involved: Step 1: Paste the first strain gauge (71) and the second strain gauge (72) on the measuring element (12) on the left side of the three-component strain balance structure, paste the third strain gauge (73) and the fourth strain gauge (74) on the measuring element (12) on the right side, paste the fifth strain gauge (75) and the seventh strain gauge (77) on the measuring element (12) on the front side, paste the sixth strain gauge (76) and the eighth strain gauge (78) on the measuring element (12) on the rear side, paste the ninth strain gauge (79) and the eleventh strain gauge (711) on the bottom surface of the trapezoidal sink groove (137) on the front side, and paste the ninth strain gauge (79) and the eleventh strain gauge (711) on the bottom surface of the trapezoidal sink groove (137) on the rear side. (137) A tenth strain gauge (710) and a twelfth strain gauge (712) are attached to the bottom surface; the first strain gauge (71), the second strain gauge (72), the fourth strain gauge (74) and the third strain gauge (73) are electrically connected in sequence to form a Wheatstone bridge, which is named U1; the fifth strain gauge (75), the sixth strain gauge (76), the eighth strain gauge (78) and the seventh strain gauge (77) are electrically connected in sequence to form a Wheatstone bridge, which is named U2; the ninth strain gauge (79), the eleventh strain gauge (711), the tenth strain gauge (710) and the twelfth strain gauge (712) are electrically connected in sequence to form a Wheatstone bridge, which is named U3; Step 2: According to the measurement requirements, select N three-component strain balance structures, where N is an integer ≥ 2, connect the bridges to the three-component strain balance structures one by one according to the method in step 1, and calibrate them to obtain the corresponding relationship coefficient between the load and the measurement signal output of each three-component strain balance structure; Step 3: Select a rectangular force measuring platform plate (8), and connect the flange planes (41) of several three-component strain balance structures to the lower end surface of the force measuring platform plate respectively; Step 4, setting the center of the rectangular force measuring platform plate (8) as the origin, and establishing a coordinate system, with the positive direction of the X axis extending backward through the origin, the positive direction of the Z axis extending leftward through the origin, and the positive direction of the Y axis extending upward through the origin, marking the area located in the positive direction of the Z axis and the positive direction of the X axis as the first area, marking the area located in the negative direction of the Z axis and the positive direction of the X axis as the second area, marking the area located in the positive direction of the Z axis and the negative direction of the X axis as the third area, and marking the area located in the negative direction of the Z axis and the negative direction of the X axis as the fourth area; If there are n three-component strain balance structures in the first region, and n is an integer ≥ 0, the Z-axial distances between the axes of the n three-component strain balance structures in the first region and the origin are marked as L Z11 , L Z12 ...L Z1n The X-axis distances between the axis centers of the n three-component strain balance structures and the origin are marked as L X11 , L X12 ...L X1n ; If there are m three-component strain balance structures in the second region, and m is an integer ≥ 0, the Z-axis distances between the axes of the m three-component strain balance structures in the second region and the origin are marked as L Z21 , L Z22 ...L Z2m The X-axis distances between the axes of the m three-component strain balance structures and the origin are marked as L X21 , L X22 ...L X2m ; If there are j three-component strain balance structures in the third region, and j is an integer ≥ 0, the Z-axial distances between the axes of the j three-component strain balance structures in the third region and the origin are marked as L Z31 , L Z32 ...L Z3j The X-axis distances between the axes of the j three-component strain balance structures and the origin are marked as L X31 , L X32 ...L X3j ; If there are k three-component strain balance structures in the fourth region, k is an integer ≥ 0, then the Z-axis distances between the axes of the k three-component strain balance structures in the fourth region and the origin are marked as L Z41 , L Z42 ...L Z4k The X-axis distances between the axes of the k three-component strain balance structures and the origin are marked as L X41 , L X42 ...L X4k ; Then the calculation formula of the six-component load on the rectangular force measuring platform plate (8) is as follows: Y=Y 11 +Y 12 +……+And 1n +Y 21 +Y 22 +……+And 2m +Y 31 +Y 32 +……+And 3j +Y 41 +Y 42 +……+And 4k X=X 11 +X 12 +……+X 1n +X 21 +X 22 +……+X 2m +X 31 +X 32 +……+X 3j +X 41 +X 42 +……+X 4k Z=Z 11 +Z 12 +……+Z 1n +Z 21 +Z 22 +……+Z 2m +Z 31 +Z 32 +……+Z 3j +Z 41 +Z 42 +……+Z 4k M z =Y 11 *L X11 +Y 12 *L X12 +……+Y 1n *L X1n +Y 21 *L X21 +Y 22 *L X22 +…… +Y 2m *L X2m -Y 31 *L X31 -Y 32 *L X32 -……-Y 3j *L X3j -Y 41 *L X41 -Y 42 *L X42 -……-Y 4k *L X4k M x =Y 11 *L Z11 +Y 12 *L Z12 +……+Y 1n *L Z1n -Y 21 *L Z21 -Y 22 *L Z22 -…… -Y 2m *L Z2m +Y 31 *L Z31 +Y 32 *L Z32 +……+Y 3j *L Z3j -Y 41 *L Z41 -Y 42 *L Z42 -……-Y 4k *L Z4k M y =-X 11 *L Z11 -X 12 *L Z12 -……-X 1n *L Z1n +X 21 *L Z21 +X 22 *L Z22 +…… +X 2m *L Z2m -X 31 *L Z31 -X 32 *L Z32 -……-X 3j *L Z3j +X 41 *L Z41 +X 42 *L Z42 +…… +X 4k *L Z4k +Z 11 *L X11 +Z 12 *L X12 +……+Z 1n *L X1n +Z 21 *L X21 +Z 22 *L X22 +…… +Z 2m *L X2m -Z 31 *L X31 -Z 32 *L X32 -……-Z 3j *L X3j -Z 41 *L X41 -Z 42 *L X42 -……-Z 4k *L X4k Wherein, Y is the longitudinal force on the rectangular force measuring platform plate (8), X is the lateral force on the rectangular force measuring platform plate (8), Z is the transverse force on the rectangular force measuring platform plate (8), and M z is the moment of force on the rectangular force platform plate (8) around the Z axis, M x is the moment of force on the rectangular force platform plate (8) around the X axis, M y is the moment of force on the rectangular force measuring platform plate (8) about the Y axis; Y 11 , Y 12 ,……,Y 1n is the longitudinal force on the n three-component strain balance structures in the first region, Y 21 , Y 22 ,……,Y 2m is the longitudinal force on the m three-component strain balance structures in the second region, Y 31 , Y 32 ,……,Y 3j is the longitudinal force on the j three-component strain balance structures in the third region, Y 41 , Y 42 ,……,Y 4k are the longitudinal forces respectively exerted on the k three-component strain balance structures in the fourth region; X 11 , X 12 ,……,X 1n is the lateral force on the n three-component strain balance structures in the first region, X 21 , X 22 ,……,X 2m is the lateral force on the m three-component strain balance structures in the second region, X 31 , X 32 ,……,X 3j is the lateral force on the j three-component strain balance structures in the third region, X 41 , X 42 ,……,X 4k is the lateral force respectively exerted on the k three-component strain balance structures in the fourth region; Z 11 , Z 12 ,……,Z 1n is the lateral force on the n three-component strain balance structures in the first region, Z 21 , Z 22 ,……,Z 2m is the lateral force on the m three-component strain balance structures in the second region, Z 31 , Z 32 ,……,Z 3j is the lateral force on the j three-component strain balance structures in the third region, Z 41 , Z 42 ,……,Z 4k The lateral forces exerted on the k three-component strain balance structures in the fourth region are respectively obtained by calculating the lateral force exerted on each of the three-component strain balance structures through the pressure-change signal measured by the U1 bridge, the lateral force is calculated through the pressure-change signal measured by the U2 bridge, and the longitudinal force is calculated through the pressure-change signal measured by the U3 bridge.

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