Integrated box type strain balance for rotor wing test

Abstract

The utility model discloses an integrated box type strain balance for a rotor wing test. A balance main body comprises a balance middle section part and balance side section parts which are arranged to be of an integrated structure, balance side section parts on the two sides, and an element installation part. The element installation part comprises four lift element installation parts symmetrically arranged at four corners of the balance side section part, two resistance element installation parts symmetrically arranged at the left and right sides of the balance side section part, two side force element installation parts symmetrically arranged at the front and rear ends of the balance middle section part, and each element installation part is used for correspondingly installing a force measurement element with a corresponding function; the two aviation plugs are mounted on the outer sides of the two balance side section parts, and all the force measuring elements are electrically connected with the two aviation plugs respectively; the balance middle section part is divided into an upper part and a lower part, the upper part and the lower part of the balance middle section part are connected into a whole by symmetrically installing two safety protection bolts, and the protection strength of the balance main body is adjusted by adjusting the thread depth of the safety protection bolts and the balance middle section part.

Description

Technical Field

[0001] The utility model relates to, but is not limited to, a helicopter rotor test technology, and in particular to an integrated box-type strain balance for rotor test. Background Art

[0002] A strain gauge balance is a device that directly measures aerodynamic loads in wind tunnel tests. It is used to measure the forces and moments acting on a test model or entity. In helicopter rotor testing, a strain gauge balance is often used to measure rotor loads. The principle is to convert the deformation of an elastic body under load into a voltage increment caused by bridge imbalance. The aerodynamic forces and moments acting on the model are then obtained through signal amplification and A / D conversion.

[0003] Strain gauge balances are characterized by their small size and light weight; easy signal transmission and fast response; low design and processing costs; and the ability to meet various support conditions. Currently, most commonly used box-type balances are assembled from various components, resulting in a relatively complex structure, requiring a high level of assembly process, and prone to interference between components. Utility Model Content

[0004] Purpose of the present invention: In order to solve the above problems, the embodiment of the present invention provides an integrated box-type strain balance for rotor testing, so as to solve the problems of the existing box-type balance, which is assembled by various parts, resulting in a relatively complex structure, high requirements for assembly process, and easy interference between components.

[0005] Technical solution of the present invention: The embodiment of the present invention provides an integrated box-type strain balance for rotor testing, comprising: a balance body 1, two safety protection bolts 2 and two aviation plugs 5;

[0006] Among them, the balance body 1 includes: a balance middle section with an integrated structure, balance side sections symmetrically arranged on both sides of the balance middle section, and an element mounting portion arranged on the balance middle section and the balance side sections, and the balance middle section and the balance side sections are arranged as an integrated structure; the element mounting portion includes: four lift element mounting portions 6 symmetrically arranged at the four corners of the two balance side sections, two resistance element mounting portions 7 symmetrically arranged on the left and right sides of the two balance side sections, and two side force element mounting portions symmetrically arranged at the front and rear ends of the balance middle section, each element mounting portion is used to install a force measuring element with a corresponding function; two aviation plugs 5 are correspondingly installed on the outside of the two balance side sections, and all force measuring elements are electrically connected to the two aviation plugs 5 respectively;

[0007] The middle section of the balance is divided into an upper and a lower part, and two bolt holes are symmetrically provided on the middle section of the balance, which are used to symmetrically install two safety protection bolts 2 to connect the middle section of the balance into an upper and a lower part as a whole, and to adjust the protection strength of the balance body 1 by adjusting the thread depth of the safety protection bolts 2 and the middle section of the balance.

[0008] Optionally, in the integrated box strain gauge balance as described above,

[0009] The horizontal center positions of the middle section and the side section of the balance are cut to form a middle isolation groove, and the upper and lower parts of the balance are connected by 8 groups of lifting element mounting parts. The middle isolation groove is used to allow the four lifting element mounting parts 6 to undergo vertical displacement changes when the balance body 1 is subjected to load changes without interfering with the middle section of the balance, so that all the load is transferred to the four lifting element mounting parts 6.

[0010] Optionally, in the integrated box strain gauge balance as described above,

[0011] An isolation slot is provided between each component mounting portion and the balance body 1; including:

[0012] The four lifting element mounting parts 6 are respectively provided with isolation grooves on both sides facing the balance body 1;

[0013] Isolation grooves are respectively provided on the upper and lower sides and the left and right sides of the two resistance element mounting parts 7;

[0014] Isolation grooves are respectively provided on the upper and lower sides, left and right sides, and front and rear sides of the two lateral force element mounting portions 8;

[0015] The isolation groove is used to reduce the load-bearing volume of the corresponding component mounting portion, so that the component mounting portion undergoes a larger displacement change when bearing a load, thereby improving the measurement accuracy of the force measuring element.

[0016] Optionally, the integrated box-type strain gauge balance as described above further comprises: two balance protection covers 3;

[0017] A step surface is formed between the balance side section and the balance middle section on each side by cutting, and two balance protection covers 3 are respectively installed around the two balance side sections so that the balance protection covers 3 are flush with the outer surface of the balance middle section after installation.

[0018] Optionally, the integrated box-type strain gauge balance as described above further comprises: two middle protective covers 4 with balance range nameplates;

[0019] The two middle protection covers 4 are respectively fixedly mounted on the outer surface of the side force element mounting portion 8 provided on the middle section of the balance, and are used to protect the side force elements.

[0020] Optionally, in the integrated box-type strain gauge balance described above, each component mounting portion is configured as a square rod structure;

[0021] The upper and lower sections of each lift element mounting portion 6 are each provided with two non-through slots, each of which is connected by a pair of waist-shaped holes provided on a symmetrical surface, and strain gauges are adhered to each pair of waist-shaped holes of each lift element mounting portion 6 to form a lift element;

[0022] Two non-through slots are respectively formed at the front and rear ends of each resistance element mounting portion 7. Each non-through slot is connected by a pair of waist-shaped holes formed on the symmetrical surface. Strain gauges are pasted into each pair of waist-shaped holes of each resistance element mounting portion 7 to form a resistance element.

[0023] Two non-through slots are respectively provided on both sides of each lateral force element mounting portion 8, and each non-through slot is connected by a pair of waist-shaped holes provided on the symmetrical surface, and strain gauges are pasted in each pair of waist-shaped holes of each lateral force element mounting portion 8 to form a lateral force element.

[0024] Optionally, in the integrated box strain gauge balance as described above,

[0025] The upper and lower end surfaces of the balance middle section of the balance body 1 are symmetrically provided with a plurality of internal threaded holes 9 so as to be fixedly installed with the upper and lower connecting members by connecting bolts.

[0026] Beneficial effects of the present invention: The present invention provides an integrated box-type strain gauge balance for rotor testing. The middle section of the balance body 1, the side sections on both sides of the balance body, and the mounting parts of each component are configured as an integrated processing structure. The upper and lower parts of the balance body 1 are connected by two additional safety bolts to prevent the balance body 1 from deforming excessively under the influence of large loads, thereby protecting the safety of the test piece and the test device. By adding a protective cover device to the outer ring of the balance body 1, the balance is prevented from being damaged by bumps during installation, thereby affecting the test accuracy of the balance. The integrated box-type strain gauge balance provided by the present invention has the following beneficial effects:

[0027] First, the integrated box strain balance is a smaller-sized integral box balance that does not require mechanical assembly. It has a simple structure, high rigidity, and low inter-dimensional coupling. Compared with the modular balance, its overall natural frequency is higher, and its measurement accuracy is higher.

[0028] Second, the integrated box strain gauge balance has an adjustable safety cover, which can effectively prevent damage to the test piece due to damage to the balance;

[0029] Third, the mounting part of each element of the integrated box-type strain balance is a square rod structure, and two non-through slots are opened on the square rod, and each non-through slot is connected by a pair of waist-shaped holes opened on the symmetrical surface, and strain gauges are pasted in each pair of waist-shaped holes to form corresponding force measuring elements, thereby forming a dual-channel mode and a balance that serves as backup for each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0031] Figure 1 A schematic diagram of the overall structure of an integrated box-type strain gauge balance for rotor testing provided by an embodiment of the present utility model;

[0032] Figure 2 for Figure 1 A schematic diagram of the overall structure of the integrated box-type strain balance for rotor testing provided by the illustrated embodiment from another perspective;

[0033] Figure 3 for Figure 1 A schematic diagram of the external structure of an integrated box-type strain balance for rotor testing provided by the illustrated embodiment;

[0034] Figure 4 for Figure 1 A front view of an integrated box strain balance for rotor testing provided by the illustrated embodiment;

[0035] Figure 5 for Figure 1 A schematic three-dimensional cross-sectional view of an integrated box strain balance for rotor testing provided by the illustrated embodiment;

[0036] Figure 6 for Figure 1 A schematic two-dimensional cross-sectional view of an integrated box strain balance for rotor testing provided by the illustrated embodiment;

[0037] Figure 7 for Figure 1 A side view of an integrated box strain gauge balance for rotor testing provided by the illustrated embodiment;

[0038] Figure 8 A schematic diagram of the force measurement principle of an integrated box-type strain balance for rotor testing provided in an embodiment of the present utility model. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0040] The above background technology has already explained the role, importance, and advantages of strain gauge balances in wind tunnel testing. Specifically, strain gauge balances have the following advantages:

[0041] 1. Small mass, fast response, easy transmission of electrical signals, conducive to the automation of force measurement test;

[0042] 2. Low design and processing costs and short development cycle; conducive to the realization of serialization of size and load, and convenient for special design for different test objects;

[0043] 3. Small size and light weight, it can be installed inside the model and can measure the whole model, component model and external attachment model;

[0044] 4. The model can be supported in various types, with strong support adaptability, and can be flexibly adjusted according to different types of wind tunnel tests.

[0045] Strain balances are classified into rod-type strain balances and box-type strain balances according to their structural form. The box-type strain balance is mainly composed of a floating frame, elastic connecting rods, tension and pressure sensors and a fixed frame. During measurement, the rotor shaft and the balance floating frame are fixedly connected to the inner and outer rings of the bearing respectively. The load on the measurement model is directly transferred to the floating frame and measured through the tension and pressure sensors on the 8 elastic connecting rods.

[0046] Obviously, most existing box balances are assembled from various parts, and their structures are relatively complex, requiring high assembly technology, and are prone to interference between components.

[0047] To address the above-mentioned issues, an embodiment of the present invention provides an integrated box-type strain balance for rotor testing. This integrated box-type strain balance can be used in helicopter rotor testing to measure the aerodynamic loads acting on the rotor or rotor model, specifically measuring three forces (normal force, axial force, and lateral force) and three moments (pitch moment, yaw moment, and roll moment).

[0048] The present invention provides the following specific embodiments that can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0049] Figure 1A schematic diagram of the overall structure of an integrated box-type strain gauge balance for rotor testing provided by an embodiment of the present utility model; Figure 2 for Figure 1 A schematic diagram of the overall structure of the integrated box-type strain balance for rotor testing provided by the illustrated embodiment from another perspective; Figure 3 for Figure 1 A schematic diagram of the external structure of an integrated box-type strain balance for rotor testing provided by the illustrated embodiment; Figure 4 for Figure 1 A front view of an integrated box strain balance for rotor testing provided by the illustrated embodiment; Figure 5 for Figure 1 A schematic three-dimensional cross-sectional view of an integrated box strain balance for rotor testing provided by the illustrated embodiment; Figure 6 for Figure 1 A schematic two-dimensional cross-sectional view of an integrated box strain balance for rotor testing provided by the illustrated embodiment; Figure 7 for Figure 1 The embodiment shown is a side view of an integrated box strain balance for rotor testing. Figures 1 to 7 As shown, the structure of the integrated box-type strain gauge balance provided by the embodiment of the present invention may include: a balance body 1, two safety protection bolts 2 and two aviation plugs 5.

[0050] like Figures 1 to 7 As shown, the balance body 1 comprises an integrated balance middle section, balance side sections symmetrically located on either side of the balance middle section, and component mounting portions disposed on the balance middle section and the balance side sections. The component mounting portions in this embodiment of the utility model include: four lift element mounting portions 6 symmetrically disposed at the four corners of the two balance side sections, two resistance element mounting portions 7 symmetrically disposed on the left and right sides of the two balance side sections, and two side force element mounting portions symmetrically disposed at the front and rear ends of the balance middle section.

[0051] Each component mounting portion in the embodiment of the present invention is used to mount a force-measuring element with a corresponding function. The two aviation plugs 5 are mounted on the outsides of the two balance side sections, and all the force-measuring elements are electrically connected to the two aviation plugs 5 respectively.

[0052] The middle section of the balance in the embodiment of the present invention is divided into an upper and a lower part, and two bolt holes are symmetrically provided on the middle section of the balance for connecting the upper and lower parts of the balance into a whole by symmetrically installing two safety protection bolts 2, and adjusting the thread depth of the safety protection bolts 2 and the middle section of the balance to adjust the protection strength of the balance body 1.

[0053] It should be noted that the balance body 1 of the integrated cassette strain gauge balance provided in this embodiment of the present invention comprises a central and side sections formed by integrated machining. The balance body is made of precipitation-hardened stainless steel 0Cr17Ni4Cu4Nb (17-4PH), which exhibits the following characteristics: 1) high strength; 2) excellent corrosion resistance; 3) good mechanical properties even at high temperatures; 4) excellent toughness; 5) good weldability; and 6) low heat treatment temperatures, which suppresses deformation and oxidation caused by heat treatment. For example, the integrated machining method involves machining the balance body 1 of the strain gauge balance to the designed dimensions in a solid solution state using precipitation-hardened, martensitic stainless steel. This is then subjected to an aging treatment to enhance its strength and hardness. Heat treatment deformation is negligible, and significant oxidation is avoided. Due to the excellent oxidation and corrosion resistance of this material, surface treatment is unnecessary.

[0054] In the embodiment of the present invention, the horizontal center positions of the middle section and the side section of the balance are cut to form a middle isolation groove, such as Figures 1 to 6 As shown, the upper and lower parts of the balance are connected by the above-mentioned 8 groups of lifting element mounting parts; the function of the middle isolation groove in the balance body 1 is: when the balance body 1 is subjected to load changes, the four lifting element mounting parts 6 undergo vertical displacement changes without interfering with the middle section of the balance, so that all the load is transferred to the four lifting element mounting parts 6.

[0055] In the specific implementation of the embodiment of the present invention, an isolation groove is provided between each component mounting portion and the balance body 1; specifically including:

[0056] (1) The four lift element mounting portions 6 are provided with isolation grooves on both sides facing the balance body 1;

[0057] (2) Isolation grooves are respectively provided on the upper and lower sides and the left and right sides of the two resistance element mounting portions 7;

[0058] (3) Isolation grooves are respectively provided on the upper and lower sides, left and right sides, and front and rear sides of the two lateral force element mounting portions 8;

[0059] The provision of the above-mentioned isolation grooves can reduce the load-bearing volume of the corresponding component mounting portion, causing the component mounting portion to undergo a larger displacement change when bearing a load, thereby improving the measurement accuracy of the force measuring element.

[0060] In one implementation of the present invention, the integrated cassette strain gauge balance further includes two balance protection covers 3. In this implementation, a stepped surface is formed by cutting between the balance side sections and the balance middle section on each side. The two balance protection covers 3 are respectively installed around the circumference of the two balance side sections, so that after installation, the balance protection covers 3 are flush with the outer surface of the balance middle section.

[0061] In one implementation of the present invention, the integrated cassette strain gauge balance further includes two central protective covers 4 with a scale nameplate. In this implementation, the two central protective covers 4 are fixedly mounted on the outer surface of the balance's central section, where the lateral force element mounting portion 8 is located, to protect the lateral force element.

[0062] In one implementation of the present invention, Figures 1 to 7 As shown, in the integrated box-type strain balance provided by the embodiment of the present invention, the mounting portion of each component is configured as a square rod structure.

[0063] The upper and lower sections of each lift element mounting portion 6 are each provided with two non-through slots, each of which is connected by a pair of waist-shaped holes provided on a symmetric surface, and strain gauges are adhered to each pair of waist-shaped holes of each lift element mounting portion 6 to form a lift element.

[0064] Two non-through slots are respectively formed at the front and rear ends of each resistance element mounting portion 7. Each non-through slot is connected by a pair of waist-shaped holes formed on the symmetrical surface. Strain gauges are pasted into each pair of waist-shaped holes of each resistance element mounting portion 7 to form a resistance element.

[0065] Two non-through slots are respectively provided on both sides of each lateral force element mounting portion 8, and each non-through slot is connected by a pair of waist-shaped holes provided on the symmetrical surface, and strain gauges are pasted in each pair of waist-shaped holes of each lateral force element mounting portion 8 to form a lateral force element.

[0066] In one implementation of the present invention, Figure 3 As shown, the upper and lower end surfaces of the balance body 1 are symmetrically provided with multiple internal threaded holes 9 so that it can be fixed with the upper and lower connecting members by connecting bolts. In specific implementation, the lower end is connected to the test bench and the upper end is connected to the test piece.

[0067] like Figure 8 The figure shows the force measurement principle of the integrated box-type strain balance for rotor testing provided by the embodiment of the present invention. The working principle of the integrated box-type strain balance for rotor testing provided by the embodiment of the present invention is as follows:

[0068] The rotor test model is mounted on the upper end face of the balance body 1, transferring the load it receives to the eight force-measuring elements formed on the balance body 1. The force-measuring elements deform, and the strain is proportional to the external force. The strain of the elastic body is collected by attaching resistance strain gauges to areas where the elastic body is significantly strained. Resistance strain gauges typically calculate average strain. As the elastic body deforms, the resistance strain gauges produce a certain resistance change. This resistance change is converted into a voltage change via a Wheatstone bridge, so the voltage change is also proportional to the external force. Finally, the voltage change is collected and calculated through A / D conversion, thereby obtaining the load on the floating frame. Similarly, the load on the rotor test model during the test and its real-time changes can be obtained.

[0069] The integrated box-type strain gauge balance for rotor testing provided by the embodiment of the present invention has a middle section of the balance body 1, side sections of the balance body on both sides, and mounting parts for each component configured as an integrated processing structure. The upper and lower parts of the balance body 1 are connected by two additional safety bolts to prevent the balance body 1 from deforming excessively under the influence of large loads, thereby protecting the safety of the test piece and the test device. A protective cover device is added to the outer ring of the balance body 1 to prevent the balance from being damaged by bumps during installation, thereby affecting the test accuracy of the balance. The integrated box-type strain gauge balance provided by the embodiment of the present invention has the following beneficial effects:

[0070] First, the integrated box strain balance is a smaller-sized integral box balance that does not require mechanical assembly. It has a simple structure, high rigidity, and low inter-dimensional coupling. Compared with the modular balance, its overall natural frequency is higher, and its measurement accuracy is higher.

[0071] Second, the integrated box strain gauge balance has an adjustable safety cover, which can effectively prevent damage to the test piece due to damage to the balance;

[0072] Third, the mounting part of each element of the integrated box-type strain balance is a square rod structure, and two non-through slots are opened on the square rod, and each non-through slot is connected by a pair of waist-shaped holes opened on the symmetrical surface, and strain gauges are pasted in each pair of waist-shaped holes to form corresponding force measuring elements, thereby forming a dual-channel mode and a balance that serves as backup for each other.

[0073] The following is a schematic illustration of the implementation of the integrated box-type strain balance for rotor testing provided by the embodiment of the present invention through specific embodiments. Specific embodiments

[0075] like Figures 1 to 6As shown, the main structure of the integrated box-type strain gauge balance provided in this embodiment includes: a balance body 1, two safety protection bolts 2, two left and right balance protection covers 3, two front and rear middle protection covers 4 with balance range nameplates, and two left and right 37-core rectangular aviation plugs 5.

[0076] This integrated box-type strain gauge balance has overall dimensions of, for example, 120 × 120 × 250 mm (width × height × length). Its rectangular shape is compact and lightweight, allowing it to be concealed within the test specimen, eliminating its frontal area and reducing wind resistance, facilitating accurate measurement of the specimen's aerodynamic performance. The integrated box-type strain gauge balance features a safety shield to prevent damage to the balance components during testing, while also protecting the test model and wind tunnel. The balance also provides two outputs, with a bridge resistance of 350Ω and a supply voltage of 10VDC.

[0077] Among them, two safety protection bolts 2 are connected and fixed to the balance body 1 by means of threads. Specifically, the middle section of the balance is divided into upper and lower parts, and the middle section of the balance is divided into upper and lower parts and two bolt holes are symmetrically provided, which are used to symmetrically install two safety protection bolts 2 to divide the middle section of the balance into upper and lower parts and connect them into a whole; in addition, the upper and lower parts of the balance are connected by 8 groups of lifting element mounting parts; in addition, the upper and lower parts of the middle section of the balance are connected by two built-in safety protection bolts 2.

[0078] Since the diameter of the safety protection bolt 2 is large, its strength is much greater than the bearing strength of the component mounting parts on the balance body 1. The thread depth of the safety protection bolt 2 can be adjusted to control it to have different protection strengths.

[0079] The integrated cassette strain gauge balance provided in this embodiment is a one-piece structure, manufactured using a monolithic forging removal method. The balance comprises eight sets of component mounting portions, each used to mount a corresponding force-measuring element. Four sets of lift element mounting portions 6 are symmetrically positioned at the four corners of the two side sections of the balance, used to measure lift, rolling moment, and pitching moment by mounting lift elements. Two sets of drag element mounting portions 7 are symmetrically positioned on the left and right sides of the two side sections of the balance, used to measure drag by mounting drag elements. Two sets of side force elements 8 are symmetrically positioned at the front and rear ends of the middle section of the balance, used to measure side force and yaw moment by mounting side force elements.

[0080] Each set of force-measuring elements in this embodiment is a double-hole cross-beam square bar structure. Each element mounting portion has a waist-shaped through-hole symmetrically positioned about the axis. Two sets of double-hole cross-beam square bar structures are symmetrically arranged on each element mounting portion. Force measurement strain gauges are attached to two different locations within each element mounting portion for backup. To better and more accurately measure the forces acting on each force-measuring element mounting portion, the thickness of the waist-shaped holes is designed based on the scale's measuring range (determined by the overall dimensions). Furthermore, the lift element mounting portion 6 has portions removed from its left and right sides and its front and back sides. This means that the lift element mounting portion 6 has isolation slots on both sides facing the balance body to prevent interference with other parts when it carries vertical loads and causes displacement changes in other directions. Similarly, the resistance element mounting portion 7 has portions removed from its upper and lower sides and its left and right sides. This means that isolation slots are provided on its upper and lower sides and its left and right sides. Similarly, the lateral force element mounting portion 8 has portions removed from its upper and lower sides, its left and right sides, and its front and back sides. In addition, 8 internal threaded holes are symmetrically set on the upper and lower end surfaces of the balance main structure so that it can be fixed and installed with the upper and lower connecting parts through connecting bolts.

[0081] The specific features of the integrated box strain gauge balance provided in this embodiment are described below:

[0082] 1. The integrated box-type strain balance is made of precipitation-hardened stainless steel 0Cr17Ni4Cu4Nb (17-4PH), which has the characteristics of high strength, good corrosion resistance, excellent toughness, good welding performance, low heat treatment temperature, and can inhibit deformation and oxidation caused by heat treatment;

[0083] 2. The balance is a whole piece of material and is processed by the integral forging removal method. Through machining (including bench machining), EDM, wire cutting and electron beam welding, the integrity of the parts is guaranteed to the greatest extent;

[0084] 3. In order to obtain good comprehensive mechanical properties, the balance can also be heat treated. The heat treatment method of stainless steel 0Cr17Ni4Cu4Nb (17-4PH) is solid solution + aging treatment. Precipitation hardening aging treatment can be arranged after the component is finished.

[0085] 4. The balance adopts an integral frame balance structure. The balance has a total of eight component mounting parts, which are used to form eight groups of force measuring elements. Among them, four lift elements are symmetrically arranged at both ends of the balance to measure lift, rolling moment and pitching moment; the drag elements are symmetrically arranged on the left and right sides of the balance to measure drag; and the side force elements are symmetrically arranged at the front and rear ends of the balance to measure side force and yaw moment.

[0086] 5. Provide two signal outputs on the force measuring element of the balance. The signal output cables are respectively connected to 37-core rectangular aviation plugs, one on each side of the balance. The bridge resistance is 350Ω and the power supply voltage is 10VDC.

[0087] 6. Two safety bolts are installed through the opening at the center of the balance, which can ensure the integrity of the balance even if the balance structure is damaged, without causing damage to the test model;

[0088] 7. Two stainless steel protective covers are added to the left and right outer ends of the balance. The protective covers wrap the strain gauge at the force measuring element of the balance as a whole, which can effectively prevent human damage and collision between equipment. Similarly, two stainless steel protective covers are also added at the front and back of the balance. The nameplate of the balance range is laser engraved on the stainless steel, which marks the range value of this balance.

[0089] Although the embodiments disclosed in the present invention are as described above, the contents are merely embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any person skilled in the art to which the present invention belongs may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention. However, the scope of patent protection of the present invention shall still be based on the scope defined by the appended claims.

Claims

1. An integrated box strain balance for rotor testing, characterized in that: include: Balance body (1), 2 safety bolts (2) and 2 flight plugs (5); The balance body (1) comprises: a balance middle section of an integrated structure, balance side sections symmetrically arranged on both sides of the balance middle section, and an element mounting section arranged on the balance middle section and the balance side sections, and the balance middle section and the balance side sections are arranged as an integrated structure; the element mounting section comprises: four lift element mounting sections (6) symmetrically arranged at the four corners of the two balance side sections, two resistance element mounting sections (7) symmetrically arranged on the left and right sides of the two balance side sections, and two side force element mounting sections (8) symmetrically arranged at the front and rear ends of the balance middle section, each element mounting section being used for correspondingly mounting a force measuring element of a corresponding function; two aviation plugs (5) are correspondingly mounted on the outer sides of the two balance side sections, and all the force measuring elements are electrically connected to the two aviation plugs (5) respectively; The middle section of the balance is divided into an upper part and a lower part, and two bolt holes are symmetrically provided on the middle section of the balance for connecting the middle section of the balance into the upper part and the lower part by symmetrically installing two safety protection bolts (2), and adjusting the thread depth of the safety protection bolts (2) and the middle section of the balance to adjust the protection strength of the balance body (1).

2. The integrated box strain balance according to claim 1, characterized in that: The horizontal center positions of the middle section and the side sections of the balance are cut to form a middle isolation groove, and the upper and lower parts of the balance are connected by 8 groups of lifting element mounting parts. The middle isolation groove is used to allow the four lifting element mounting parts (6) to undergo vertical displacement changes when the balance body (1) is subjected to load changes without interfering with the middle section of the balance, so that all the load is transferred to the four lifting element mounting parts (6).

3. The integrated box strain balance according to claim 2, characterized in that: An isolation slot is provided between each component mounting portion and the balance body (1); including: Four lifting element mounting portions (6) are respectively provided with isolation grooves on both sides facing the balance body (1); Isolation grooves are respectively provided on the upper and lower sides and the left and right sides of the two resistance element mounting parts (7); Isolation grooves are respectively provided on the upper and lower sides, left and right sides, and front and rear sides of the two lateral force element mounting portions (8); The isolation groove is used to reduce the load-bearing volume of the corresponding component mounting portion, so that the component mounting portion undergoes displacement changes when bearing load, thereby improving the measurement accuracy of the force measuring element.

4. The integrated box strain balance according to any one of claims 1 to 3, characterized in that: Also includes: 2 balance protection covers (3); A step surface is formed between the balance side section and the balance middle section on each side by cutting, and two balance protection covers (3) are respectively installed on the circumferences of the two balance side sections so that the balance protection covers (3) are flush with the outer surface of the balance middle section after installation.

5. The integrated box strain balance according to any one of claims 1 to 3, characterized in that: Also includes: 2 middle protective covers with balance range nameplates (4); The two middle protection covers (4) are respectively fixedly mounted on the outer surface of the side force element mounting portion (8) provided on the middle section of the balance, and are used to protect the side force element.

6. The integrated box strain balance according to any one of claims 1 to 3, characterized in that: The mounting parts of each component are arranged as a square rod structure; The upper section and the lower section of each lift element mounting portion (6) are respectively provided with two non-through slots, each non-through slot is connected by a pair of waist-shaped holes provided on a symmetric surface, and strain gauges are pasted into each pair of waist-shaped holes of each lift element mounting portion (6) to form a lift element; Two non-through slots are respectively provided at the front and rear ends of each resistance element mounting portion (7), each non-through slot is connected by a pair of waist-shaped holes provided on a symmetrical surface, and strain gauges are pasted into each pair of waist-shaped holes of each resistance element mounting portion (7) to form a resistance element; Two non-through slots are respectively provided on both sides of each lateral force element mounting portion (8), each non-through slot is connected by a pair of waist-shaped holes provided on a symmetrical surface, and strain gauges are pasted into each pair of waist-shaped holes of each lateral force element mounting portion (8) to form a lateral force element.

7. The integrated box strain gauge balance according to any one of claims 1 to 3, characterized in that: The upper and lower end surfaces of the balance middle section of the balance body (1) are symmetrically provided with a plurality of internal threaded holes (9) so as to be fixedly mounted with the upper and lower connecting members via connecting bolts.

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