A thrust measurement system for high-model test of launch vehicle engines

Abstract

The present invention relates to the technical field of space launch vehicles, and provides a thrust measurement system for a high-model test of a launch vehicle engine, comprising: a vacuum chamber fixed on a foundation, used to provide a vacuum environment for the engine to be tested; a calibration mechanism, connected to the engine to be tested in the vacuum chamber and at least partially arranged outside the vacuum chamber; a measuring mechanism, arranged in the vacuum chamber and connected to the engine to be tested in the vacuum chamber, used to obtain the thrust of the engine. In the thrust measurement system for a high-model test of a launch vehicle engine provided by the present invention, the measuring mechanism is arranged in the vacuum chamber, and the calibration mechanism is at least partially arranged outside the vacuum chamber, so that the size of the vacuum chamber is reduced while ensuring the platform, channel setting and personnel operating space required for the high-altitude simulation test rocket-ground docking operation, which is conducive to reducing the workload of the ejection system and improving the performance of the system high-model test.

Description

Technical Field

[0001] The invention relates to the technical field of space launch vehicles, and in particular to a thrust measurement system for a high-model test of a launch vehicle engine. Background Art

[0002] The thrust measurement system is a thrust calibration system in the engine ground test. The basic method of thrust measurement is to fix the engine on the thrust frame, and the frame and the fixed frame are connected with elastic sheets. During the test run, the thrust generated by the engine causes the frame and the engine to move in the thrust direction together, and transmits the load to the working sensor through the force transmission mechanism. The output signal of the working sensor is recorded by the data acquisition system. In order to improve the measurement accuracy and remove the influence of system deviation, the working sensor is calibrated by online calibration. The method is to calibrate the calibration force through the calibrated standard sensor, and use the standard force to calibrate the output signal of the working sensor through the force transmission system. The output signal is processed by the calibration algorithm and converted into a thrust value. The standard force is transmitted from the calibration foundation to the foundation column and then to the foundation. The engine thrust moves through the fixed frame foundation to the foundation column and then to the foundation.

[0003] During the high-model test of the engine, the engine needs to be placed in a vacuum chamber for an ignition test in a vacuum environment. There are hundreds of interfaces of various types, such as liquid, gas, control, and measurement, between the engine and the ground test system. Personnel are required to perform connection and test operations during the preparation and evacuation stages of the engine test. The vacuum chamber needs to set up a working platform and channel for the operation and leave appropriate operating space. However, the thrust measurement system is complex and large in size. If the entire thrust measurement system is placed directly in the vacuum chamber, the size of the vacuum chamber will be greatly increased, which will become an additional burden on the ejection system and reduce the high-model test performance of the system. Summary of the invention

[0004] Therefore, the present invention aims to solve the technical problems that the thrust measurement system in the prior art is complex and large in size. If the entire thrust measurement system is directly placed in a vacuum chamber, the size of the vacuum chamber will be greatly increased, which will become an additional burden on the ejection system and reduce the high-model test performance of the system, thereby providing a high-model test thrust measurement system for a launch vehicle engine.

[0005] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0006] The present invention provides a thrust measurement system for a high-model test of a carrier rocket engine, comprising: a vacuum chamber, fixed on a foundation, and used for providing a vacuum environment for an engine to be tested; a calibration mechanism, connected to the engine to be tested in the vacuum chamber and at least partially arranged outside the vacuum chamber; and a measuring mechanism, arranged in the vacuum chamber and connected to the engine to be tested in the vacuum chamber, and used for obtaining the thrust of the engine.

[0007] Furthermore, the measuring mechanism includes a moving frame, a fixed frame and a fixed frame base arranged coaxially; the moving frame and the fixed frame are connected as a whole, and the bottom of the moving frame is connected to the top of the engine to be tested; the fixed frame base is fixed on the inner wall of the vacuum chamber and connected to the fixed frame; a working sensor is arranged between the moving frame and the fixed frame base for obtaining the thrust of the engine.

[0008] Furthermore, the fixed frame, the movable frame and the fixed frame base all have an annular main body; the diameter of the movable frame is smaller than the diameter of the fixed frame, and the fixed frame is sleeved on the outside of the movable frame; the fixed frame base is located above the fixed frame, and the fixed frame base is connected to the fixed frame by bolts; along the circumferential direction of the movable frame, a plurality of the working sensors are evenly spaced.

[0009] Furthermore, a plurality of connecting arms are arranged at intervals on the outer wall of the fixed frame base along the circumferential direction of the fixed frame base; a plurality of mounting seats adapted to the connecting arms are arranged at intervals on the inner wall of the vacuum chamber along the circumferential direction of the vacuum chamber, and the bottom of the mounting seat is connected to the top of the connecting arm.

[0010] Furthermore, the upper and lower end surfaces of the movable frame and the fixed frame are flush, and the upper and lower end surfaces of the two are connected by elastic sheets arranged along the radial direction of the fixed frame; a plurality of the elastic sheets are arranged at intervals along the circumferential direction of the fixed frame.

[0011] Furthermore, along the length direction of the elastic sheet, the thickness at both ends of the elastic sheet is different from the thickness in the middle.

[0012] Furthermore, the launch vehicle engine high-model test thrust measurement system also includes a foundation flange, which is fixed on the foundation; the bottom of the vacuum chamber is fixed on the foundation through the foundation flange.

[0013] Furthermore, a plurality of foundation columns are arranged at intervals on the side walls of the vacuum chamber along the circumferential direction of the vacuum chamber; a plurality of annular beams are arranged at intervals on the side walls of the vacuum chamber along the axial direction of the vacuum chamber, and the annular beams are connected to the foundation columns as a whole.

[0014] Furthermore, the calibration mechanism includes a calibration base, a calibration force source, a standard sensor and a calibration rod; the calibration base is located outside the vacuum chamber and is arranged on the top of the vacuum chamber; the calibration force source and the standard sensor are both arranged on the calibration base; one end of the calibration rod extends into the vacuum chamber and is connected to the engine to be tested, and the other end is connected to the calibration force source.

[0015] Furthermore, the calibration foundation has a herringbone-shaped main body; two piers are arranged at intervals on the top surface of the annular beam located at the uppermost layer of the vacuum chamber, and both ends of the calibration foundation are respectively connected to the piers.

[0016] The technical solution of the present invention has the following advantages:

[0017] The thrust measurement system for high-model test of a carrier rocket engine provided by the present invention has a measuring mechanism arranged in the vacuum chamber, and a calibration mechanism at least partially arranged outside the vacuum chamber, so that the size of the vacuum chamber is reduced while ensuring the platform, channel arrangement and personnel operating space required for the high-altitude simulation test rocket-ground docking operation, which is beneficial to reducing the workload of the ejection system and improving the performance of the system high-model test. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of a thrust measurement system for a high-model test of a launch vehicle engine (after the side wall of the vacuum chamber is hidden) in an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of a thrust measurement system for a high-model test of a launch vehicle engine in an embodiment of the present invention;

[0021] Figure 3 Schematic diagram of a measuring mechanism in a thrust measurement system for a high-model test of a launch vehicle engine in an embodiment of the present invention;

[0022] Figure 4 for Figure 3 A magnified schematic diagram of the local structure;

[0023] Figure 5 It is a schematic diagram of a working sensor in a thrust measurement system for a high-model test of a launch vehicle engine in an embodiment of the present invention;

[0024] Figure 6 It is a schematic diagram of the connection relationship between the fixed frame and the moving frame (under one viewing angle) in the thrust measurement system of the high-model test of the launch vehicle engine in the embodiment of the present invention;

[0025] Figure 7 Schematic diagram of the connection relationship between the fixed frame and the moving frame in the thrust measurement system of the high-model test of the launch vehicle engine in the embodiment of the present invention (from another perspective);

[0026] Figure 8 It is a schematic diagram of a foundation flange in a thrust measurement system for a high-model test of a launch vehicle engine in an embodiment of the present invention;

[0027] Fig. 9 It is a schematic diagram of a fixed frame foundation of a thrust measurement system for a high-model test of a launch vehicle engine in an embodiment of the present invention;

[0028] Fig.10 It is a schematic diagram of a fixed frame in a thrust measurement system for a high-model test of a launch vehicle engine in an embodiment of the present invention;

[0029] Fig.11 Schematic diagram of a moving frame in a thrust measurement system for a high-model test of a launch vehicle engine in an embodiment of the present invention;

[0030] Fig.12 It is a schematic diagram of an elastic sheet in a thrust measurement system for a high-model test of a launch vehicle engine in an embodiment of the present invention.

[0031] Description of reference numerals:

[0032] 1. Vacuum chamber; 2. Calibration mechanism; 3. Measuring mechanism; 4. Engine; 5. Foundation; 6. Foundation flange; 7. Foundation column; 8. Annular beam; 9. Pier; 10. Calibration foundation; 11. Standard sensor; 12. Calibration rod; 13. Fixed frame foundation; 14. Fixed frame; 15. Moving frame; 16. Connecting arm; 17. Working sensor; 18. Elastic sheet. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] like Figure 1 As shown, this embodiment provides a high-model test thrust measurement system for a carrier rocket engine 4, comprising: a vacuum chamber 1, fixed on a foundation 5, for providing a vacuum environment for the engine 4 to be tested; a calibration mechanism 2, connected to the engine 4 to be tested in the vacuum chamber 1 and at least partially arranged outside the vacuum chamber 1; a measuring mechanism 3, arranged in the vacuum chamber 1 and connected to the engine 4 to be tested in the vacuum chamber 1, for obtaining the thrust of the engine 4.

[0038] In the high-model test thrust measurement system for the launch vehicle engine 4 provided in this embodiment, the measuring mechanism 3 is arranged in the vacuum chamber 1, and the calibration mechanism 2 is at least partially arranged outside the vacuum chamber 1, so that the size of the vacuum chamber 1 is reduced while ensuring the platform, channel settings and personnel operating space required for the high-altitude simulation test rocket-ground docking operation, which is beneficial to reducing the workload of the ejection system and improving the performance of the system high-model test.

[0039] like Figure 3 , Figure 4 , Figure 5 , Figure 6 as well as Figure 7 As shown, the measuring mechanism 3 includes a coaxially arranged moving frame 15, a fixed frame 14 and a fixed frame base 13; the moving frame 15 is connected to the fixed frame 14 as a whole, and the bottom of the moving frame 15 is connected to the top of the engine 4 to be tested; the fixed frame base 13 is fixed on the inner wall of the vacuum chamber 1 and is connected to the fixed frame 14; a working sensor 17 is arranged between the moving frame 15 and the fixed frame base 13 for obtaining the thrust of the engine 4.

[0040] The fixed frame 14, the movable frame 15 and the fixed frame base 13 all have an annular main body; the diameter of the movable frame 15 is smaller than the diameter of the fixed frame 14, and the fixed frame 14 is sleeved outside the movable frame 15; the fixed frame base 13 is located above the fixed frame 14, and the fixed frame base 13 and the fixed frame 14 are connected by bolts; along the circumferential direction of the movable frame 15, a plurality of working sensors 17 are evenly spaced. For example, 2-4 working sensors 17 can be evenly spaced.

[0041] like Fig.10 As shown, for the fixed frame 14, the fixed frame 14 can adopt an annular main body, and the upper end surface of the fixed frame 14 can be provided with four fixed frame 14 positioning holes and bolt holes for connecting the fixed frame 14 with the fixed frame base 13, and the bolt holes can be provided in four groups, each with four. In addition, the upper and lower end surfaces of the fixed frame 14 can be provided with eight groups of elastic sheet 18 hole groups, each of which includes an elastic sheet 18 positioning hole and four bolt holes for connecting the elastic sheet 18.

[0042] like Fig.11 As shown, for the moving frame 15, the moving frame 15 is provided with a center hole, the upper end surface of the moving frame 15 is provided with three working sensor 17 positioning holes, and the upper and lower end surfaces of the moving frame 15 are respectively provided with eight groups of elastic sheet 18 holes, each group can include one elastic sheet 18 positioning hole and four bolt holes for connecting the elastic sheet 18. The lower end surface of the moving frame 15 can be provided with eight connection positioning holes for connecting with the engine 4, and the two can be connected by bolts.

[0043] Among them, a plurality of connecting arms 16 are arranged at intervals on the outer wall of the fixed frame base 13 along the circumferential direction of the fixed frame base 13, and the length direction of the connecting arms 16 is consistent with the radial direction of the fixed frame base 13; a plurality of mounting seats compatible with the connecting arms 16 are arranged at intervals on the inner wall of the vacuum chamber 1 along the circumferential direction of the vacuum chamber 1, and the bottom of the mounting seat and the top of the connecting arm 16 can be connected by bolts.

[0044] like Fig. 9As shown, for the fixed frame foundation 13, the fixed frame foundation 13 can adopt an annular main body and the outer side wall has four connecting arms 16, and the four connecting arms 16 are respectively connected to four mounting seats. In order to be more conducive to the transmission of force in the working state of the engine 4, the fixed frame foundation 13 can be set at the bottom and the mounting seat can be set at the top. The fixed frame foundation 13 is provided with a center hole, and the lower end surface of the annular main body is provided with sensor positioning holes and four fixed frame 14 positioning holes corresponding to the number of working sensors based on the center hole. The sensor positioning hole is used for the position limit of the working sensor 17, and the fixed frame 14 positioning hole is used for the position limit of the fixed frame 14. After the working sensor 17, the fixed frame 14, the moving frame 15 and other structures are installed and centered, the position of the fixed frame 14 is determined, and then the position limit of the fixed frame 14 is performed. In order to avoid over-positioning during the installation process, the fixed frame 14 positioning hole can be matched on site with the fixed frame 14 after the position of the fixed frame 14 is determined.

[0045] The movable frame 15 and the fixed frame 14 have the same axial dimensions, so that the upper and lower end surfaces of the two are flush, and the upper and lower end surfaces of the two are connected by elastic sheets 18 arranged along the radial direction of the fixed frame 14; a plurality of the elastic sheets 18 are arranged at intervals along the circumferential direction of the fixed frame 14. For example, the elastic sheets 18 can be arranged in a group of two, and each end surface of the fixed frame 14 and the movable frame 15 can be provided with a total of four groups of elastic sheets 18. For example, a positioning hole and four bolt holes for connecting bolts can be respectively arranged at both ends of each elastic sheet 18, and the elastic sheet 18 can be connected to the fixed frame 14 and the movable frame 15 by bolts.

[0046] like Fig.12 As shown, the thickness at both ends of the elastic sheet 18 along the length direction of the elastic sheet 18 is different from the thickness in the middle. For example, the thickness at both ends of the elastic sheet 18 along the length direction of the elastic sheet 18 can be greater than the thickness in the middle. For example, the thickness at both ends of the elastic sheet 18 along the length direction of the elastic sheet 18 can also be less than the thickness in the middle. In this way, the elastic sheet 18 is used to provide radial rigidity constraints and axial elastic damping constraints, and the smaller the elastic damping, the more it can reduce the loss, so the elastic sheet 18 adopts a variable cross-section sheet structure and adopts a material with good elasticity and high strength.

[0047] like Figure 8As shown, the thrust measurement system for the high-model test of the launch vehicle engine 4 also includes a foundation flange 6, which is fixed on the foundation 5; the bottom of the vacuum chamber 1 is fixed on the foundation 5 through the foundation flange 6. For the foundation flange 6, it is required to control the flatness of the upper end face of the foundation flange 6, the cylindricality of the inner diameter circle, and the verticality of the end face. The foundation flange 6 and the foundation 5 can be cast and fused, and it is required to control the horizontal deviation of the end face of the foundation flange 6 after casting. The center of the inner diameter circle of the foundation flange 6 can be used as the center reference of the entire thrust measurement system, and the end face of the foundation flange 6 can be used as the horizontal reference of the entire thrust measurement system.

[0048] Among them, a plurality of basic columns 7 are arranged at intervals on the side bulkhead of the vacuum chamber 1 in the circumferential direction of the vacuum chamber 1, for example, four basic columns 7 can be arranged at intervals along the circumferential direction of the vacuum chamber 1; a plurality of annular beams 8 are arranged at intervals on the side bulkhead of the vacuum chamber 1 in the axial direction of the vacuum chamber 1, for example, two annular beams 8 can be arranged at intervals along the axial direction of the vacuum chamber 1, and the annular beams 8 are connected to the basic columns 7 as a whole. For example, a mounting seat for connecting with the connecting arm 16 of the fixed frame foundation 13 can be fixed on the basic column 7.

[0049] The calibration mechanism 2 includes a calibration base 10, a calibration force source, a standard sensor 11, and a calibration rod 12; the calibration base 10 is located outside the vacuum chamber 1 and is arranged on the top of the vacuum chamber 1; the calibration force source and the standard sensor 11 are both arranged on the calibration base 10; one end of the calibration rod 12 extends into the vacuum chamber 1 and is connected to the engine 4 to be tested, and the other end is connected to the calibration force source. For example, the calibration force source can be a device that can apply tension to the rod.

[0050] like Figure 2 As shown, the calibration base 10 has a herringbone-shaped main body; two piers 9 are arranged at intervals on the top surface of the annular beam 8 located at the uppermost layer of the vacuum chamber 1, and the two ends of the calibration base 10 are respectively connected to the piers 9. For the calibration base 10, a herringbone-shaped main body can be adopted, and a calibration base 10 center hole, a standard sensor 11 positioning hole and two force source mechanism positioning holes are arranged at the top. Four bolt holes connected to the piers 9 can be arranged at both ends of the herringbone-shaped main body. The herringbone-shaped main body is installed above the top cover of the vacuum chamber 1, and after connection, positioning holes are drilled at both ends together with the base of the vacuum chamber 1.

[0051] Among them, the coaxial transmission relationship in the thrust measurement system of the high-model test of the launch vehicle engine 4 is: the center of the inner diameter circle center hole of the foundation flange 6 is the reference center of the foundation flange 6, the center of the center hole of the fixed frame foundation 13 is the center of the fixed frame foundation 13, and the center of the fixed frame foundation 13 is aligned with the reference center during installation. The movable frame 15, the fixed frame 14, and the elastic sheet 18 are assembled, and the connection positioning holes between the two ends of the elastic sheet 18 and the movable frame 15 and the fixed frame 14 are punched, and the relative positions of the movable frame 15 and the fixed frame 14 are locked to form an immovable rigid assembly. The assembly is based on the center of the center hole of the movable frame 15, and is aligned with the center of the fixed frame foundation 13 during installation. The connection positioning holes between the fixed frame 14 and the fixed frame foundation 13 are punched, and the relative positions of the movable and fixed frame 14 assembly and the fixed frame foundation 13 are locked. The engine 4 connection limit hole is processed based on the center of the movable frame 15, and the thrust or simulated thrust can be aligned with the movable frame 15 after the engine 4 is installed. The center of the moving frame 15 is aligned with the center of the fixed frame 14. The positioning holes at the upper and lower ends of the sensor assembly are respectively located on the lower end surface of the fixed frame foundation 13 and the upper end surface of the moving frame 15. By aligning the center of the moving frame 15 and the center of the fixed frame 14, the sensor group can be vertical and not tilted, and aligned with the center, and finally the thrust or simulated thrust is consistent with the direction of the working sensor 17 group. The calibration base 10 is based on the center hole of the calibration base 10 and is aligned with the base center of the foundation flange 6. The calibration base 10 is based on its own center hole to machine the positioning hole of the standard sensor 11. The standard sensor 11 is aligned with the base center through the positioning hole and the calibration center hole, thereby ensuring the centering of the force source. The pull rod penetrates from the top cover of the vacuum chamber 1 and extends to the bottom of the moving frame 15. A center hole is set at the top cover, and it is aligned with the center of the foundation flange 6 during installation. Smooth cylindrical mating surfaces are set at the upper and lower ends of the pull rod, and they are matched with the center of the top cover and the center of the moving frame 15, and finally the flexible long pull rod is aligned. After the force source is centered and the tie rod is centered, the direction of the calibration force can be consistent with the direction of the real engine 4 thrust.

[0052] Working principle of the thrust measurement system for the launch vehicle engine 4 high-model test:

[0053] The standard force source is connected to the pull rod, which is connected to the engine 4. Three working sensors 17 are set between the fixed frame foundation 13 and the moving frame 15. The moving frame 15 is connected to the fixed frame 14 through an elastic sheet 18. The fixed frame 14 is connected to the fixed frame foundation 13. The fixed frame foundation 13 is connected to the foundation column 7, and the foundation column 7 is connected to the foundation 5. In the working state, the engine 4 is deformed upward under the action of thrust, pressing the working sensor 17 group, and moving upward with the moving frame 15. Several elastic sheets 18 are installed on the upper and lower parts of the moving frame 15 and the fixed frame 14. The elastic sheet 18 group deforms and constrains the moving frame 15, and the load is further transmitted to the fixed frame foundation 13, the foundation column 7 and the foundation 5. In the calibration state, the standard force source simulates the engine 4 force and acts on the engine 4 through the pull rod. The acquisition system calibrates the thrust of the engine 4 according to the output of the working sensor 17 group under the working state of the engine 4 and the force value relationship corresponding to the calibration output.

[0054] Among them, calibration and measurement consistency analysis can be carried out based on the Ansys workbench simulation integration platform. The model includes three parts: vacuum chamber 1, calibration basis 10, and fixed frame basis 13. Five working condition analyses are carried out, namely vacuum measurement, vacuum calibration, atmospheric measurement, atmospheric calibration, and vacuum no-load. The purpose is to analyze the influence of calibration force and vacuum force (external pressure 0.1MPa) on thrust measurement.

[0055] Calibration force influence:

[0056] The results are shown in Table 1. As can be seen from Table 1, the deformation of the vacuum measurement, vacuum calibration fixed frame foundation 13 and the deformation at the sensor position on the fixed frame foundation 13 are the same; the deformation of the atmospheric measurement, atmospheric calibration fixed frame foundation 13 and the deformation at the sensor position on the fixed frame foundation 13 are the same. This shows that the calibration and measurement states are well consistent and the calibration force has almost no effect.

[0057] Influence of pumping force:

[0058] From Table 1, it can be seen that the difference between the deformation of the fixed frame foundation 13 in vacuum measurement and atmospheric measurement and the deformation at the position of the sensor on the fixed frame foundation 13 is 0.1mm; the difference between the deformation of the fixed frame foundation 13 in atmospheric measurement and atmospheric measurement and the deformation at the position of the sensor on the fixed frame foundation 13 is 0.12mm. It can be verified again from the vacuum no-load condition that this part is the deformation caused by the evacuation force, but the value is small, and considering that the debugging method can be used to determine the system deviation caused by it and correct it in the algorithm, it still meets the measurement requirements.

[0059] Thrust measurement uncertainty:

[0060] After debugging and testing, the thrust measurement system has a system uncertainty of 0.35% under the condition of 100000N engine 4 thrust, which meets the engine 4 thrust measurement requirements.

[0061] Table 1: Effect of calibration force and evacuation force on thrust measurement

[0062]

[0063] In summary, the calibration base 10 and the fixed frame base 13 in the thrust measurement system of the launch vehicle engine 4 high-model test in the present application are separated, which can avoid the influence of the recoil force on the thrust measurement, and ensure that the force state of the simulated engine 4 (i.e., the calibration state) is as consistent as possible with the stress state of the real engine 4 working state. The calibration base 10 and the fixed frame base 13 are independent of each other, and the calibration base 10 is placed on the top, and the fixed frame base 13 is at the bottom. The recoil force acts on the center of the calibration base 10 and is transmitted to the foundation column 7 through the main body of the herringbone. After the concave deformation of the center of the calibration base 10 is buffered by the longer herringbone main body, the deformation effect on the foundation column 7 is already very small. Moreover, there is a large distance between the nodes of the calibration base 10 and the foundation column 7, and the nodes of the fixed frame base 13 and the foundation column 7, which can further reduce the influence of the recoil force. Thereby basically achieving the consistency of the force state of the simulated engine 4 (i.e., the calibration state) and the stress state of the real engine 4 working state.

[0064] In the thrust measurement system of the high-model test of the launch vehicle engine 4 in the present application, the thrust measurement is integrated with the vacuum chamber 1, and the calibration mechanism 2 is outside and the measuring mechanism 3 is inside. The pull rod starts from the calibration force source outside the vacuum chamber 1, passes through the chamber and extends to the engine 4 inside the chamber, reducing the influence of vacuum extraction on the thrust measurement accuracy. Under the premise of ensuring the platform, channel setting and personnel operation space required for the high-altitude simulation test arrow-ground docking operation, the workload of the ejection system is reduced. In addition, four basic columns 7 are arranged outside the vacuum chamber 1, which are welded to the wall of the vacuum chamber 1, and four mounting seats are arranged at the corresponding positions of the basic columns 7 on the inside of the vacuum chamber 1 to realize the rooting connection of the fixed frame foundation 13. Two piers 9 extend from the top surface of the annular beam 8 on the side of the vacuum chamber 1. In order to adapt to the arc-shaped top cover shape of the vacuum chamber 1, the calibration foundation 10 adopts a herringbone main structure, with both ends connected to the piers 9, and the calibration force source is installed in the center. The calibration force is implemented to the engine 4 by using a pull rod. Moreover, adding annular beams 8 to the middle and top of the foundation columns 7 outside the vacuum chamber 1 can increase the overall stiffness between the four foundation columns 7, reduce the deformation caused by evacuating the negative pressure and the influence on the accuracy deviation of thrust measurement.

[0065] In the thrust measurement system of the launch vehicle engine 4 high-model test, the thrust and calibration force of the engine 4 are in the same direction as the working sensor 17. The thrust and calibration force of the engine 4 are input forces, and the working sensor 17 is the output force. To ensure the measurement accuracy, the input and output are as in the same direction as possible, that is, all force transmission components from the force source to the sensor must transmit force along the original direction of the force.

[0066] The force transmission structure in the thrust measurement system of the high-modulus test of the launch vehicle engine 4 in this application has reasonable rigidity, which can avoid the loss of force value in the force transmission structure. In addition, the distance between the load point and the support point of the fixed frame foundation 13, the calibration foundation 10 and the foundation column 7 is large, and the deformation is mainly bending deformation after loading. In order to reduce deformation and control loss, the annular main body can be a hollow box-type structure, and the size is enlarged in the bending direction.

[0067] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A thrust measurement system for a high-model test of a launch vehicle engine, characterized in that: include: A vacuum chamber (1) is fixed on a foundation (5) and is used to provide a vacuum environment for an engine (4) to be tested; A calibration mechanism (2) connected to the engine (4) to be tested in the vacuum chamber (1) and at least partially arranged outside the vacuum chamber (1); A measuring mechanism (3) is arranged in the vacuum chamber (1) and is connected to the engine (4) to be tested in the vacuum chamber (1), and is used to obtain the thrust of the engine (4); The measuring mechanism (3) comprises a movable frame (15), a fixed frame (14) and a fixed frame base (13) which are coaxially arranged; The movable frame (15) is integrally connected to the fixed frame (14), and the bottom of the movable frame (15) is connected to the top of the engine (4) to be tested; The fixed frame base (13) is fixed on the inner wall of the vacuum chamber (1) and is connected to the fixed frame (14); A working sensor (17) is provided between the moving frame (15) and the fixed frame base (13) for obtaining the thrust of the engine (4); The fixed frame (14), the movable frame (15) and the fixed frame base (13) all have an annular main body; The diameter of the movable frame (15) is smaller than the diameter of the fixed frame (14), and the fixed frame (14) is sleeved on the outside of the movable frame (15); The fixed frame foundation (13) is located above the fixed frame (14), and the fixed frame foundation (13) and the fixed frame (14) are connected via bolts; A plurality of working sensors (17) are evenly spaced along the circumferential direction of the moving frame (15); A plurality of connecting arms (16) are arranged at intervals on the outer side wall of the fixed frame base (13) in the circumferential direction of the fixed frame base (13); a plurality of mounting seats adapted to the connecting arms (16) are arranged at intervals on the inner side wall of the vacuum chamber (1) in the circumferential direction of the vacuum chamber (1), and the bottom of the mounting seat is connected to the top of the connecting arm (16); The upper and lower end surfaces of the movable frame (15) and the fixed frame (14) are flush, and the upper and lower end surfaces of the two are connected via an elastic sheet (18) arranged along the radial direction of the fixed frame (14); A plurality of elastic sheets (18) are arranged at intervals along the circumferential direction of the fixed frame (14).

2. The launch vehicle engine high model test thrust measurement system according to claim 1, characterized in that: Along the length direction of the elastic sheet (18), the thickness at both ends of the elastic sheet (18) is different from the thickness in the middle.

3. The launch vehicle engine high model test thrust measurement system according to claim 1, characterized in that: It also includes a foundation flange (6), wherein the foundation flange (6) is fixed on the foundation (5); The bottom of the vacuum chamber (1) is fixed on the foundation (5) via the foundation flange (6).

4. The launch vehicle engine high-model test thrust measurement system according to claim 3, characterized in that: A plurality of foundation columns (7) are arranged at intervals on the side walls of the vacuum chamber (1) along the circumferential direction of the vacuum chamber (1); A plurality of annular beams (8) are arranged at intervals on the side walls of the vacuum chamber (1) along the axial direction of the vacuum chamber (1), and the annular beams (8) are integrally connected to the foundation columns (7).

5. The launch vehicle engine high-model test thrust measurement system according to claim 4, characterized in that: The calibration mechanism (2) comprises a calibration base (10), a calibration force source, a standard sensor (11) and a calibration pull rod (12); The calibration base (10) is located outside the vacuum chamber (1) and is arranged on the top of the vacuum chamber (1); The calibration force source and the standard sensor (11) are both arranged on the calibration base (10); One end of the calibration rod (12) extends into the vacuum chamber (1) and is connected to the engine (4) to be tested, and the other end is connected to the calibration force source.

6. The launch vehicle engine high-model test thrust measurement system according to claim 5, characterized in that: The calibration base (10) has a herringbone-shaped body; Two piers (9) are arranged at intervals on the top surface of the annular beam (8) located at the uppermost layer of the vacuum chamber (1), and both ends of the calibration foundation (10) are respectively connected to the piers (9).

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