Helicopter skid undercarriage static test device and method

Abstract

The invention provides a helicopter skid undercarriage static test device and method. The device comprises a constraint assembly, a skid undercarriage assembly, a Z-direction loading assembly, a Y-direction loading assembly and an X-direction loading assembly, the skid undercarriage assembly is installed on the constraint assembly in an inverted mode, and the Z-direction loading assembly and the Y-direction loading assembly are installed at Z-direction and Y-direction load common application points on the skid undercarriage assembly respectively and used for applying Z-direction and Y-direction test loads. The X-direction loading assembly is installed at an X-direction load applying point on the skid undercarriage assembly and used for applying an X-direction load. The constraint and loading requirements of a rear three-point skid type undercarriage static test of a load-carrying aircraft can be met, the real boundary conditions of a skid undercarriage are simulated through a simpler constraint and loading device, and the requirement that a loading point is located on the surface of a skid cylinder of a tubular structure is met.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of helicopter ground test, and particularly relates to a helicopter skid landing gear static test device and method. BACKGROUND

[0002] The skid landing gear device is widely used in aircraft design due to its simple and reliable structure, low processing cost and simple and convenient maintenance. When the aircraft lands, the skid landing gear transmits loads in different directions through the skid cylinder in contact with the ground, and absorbs energy by relying on the tubular or rectangular arch beam and the clamp with rubber buffer pad at the connection between the aircraft and the skid. The skid landing gear static test is to verify the static strength characteristics of the skid landing gear structure under the real installation boundary conditions. The static test loading technology of the large-size and high-load-capacity tubular structure skid landing gear used in 4-ton aircraft is difficult, and it is necessary to simulate the real constraint conditions of the skid landing gear, while ensuring accurate test load application after the skid cylinder is loaded and rotated.

[0003] The method of building a gantry suspension constraint landing gear to simulate real boundary conditions is complex, and the size and strength of the constraint gantry are required to be high. At the same time, since the load application point of the skid landing gear is located at the bottom surface of the skid cylinder, the load point is multiple and the load mass is large, so it is not easy to implement counterweight loading and lead screw loading, and a loading device connected with the tubular structure skid cylinder needs to be designed for loading through a hydraulic actuator.

[0004] In order to simplify the constraint design form, meet the test loading position of the skid cylinder bottom surface contact point, and ensure that the load application is not affected by the rotation of the skid cylinder under load, the present application designs an inverted constraint and loading compensation device for the skid landing gear. SUMMARY

[0005] In order to solve the problem of inaccurate load application of the skid landing gear under multi-dimensional load working conditions due to the self-rotation of the skid cylinder, the present application provides a helicopter skid landing gear static test device and method, which meets the constraint and loading requirements of the static test of the rear three-point skid landing gear of a 4-ton aircraft. A simpler constraint and loading device is used to simulate the real boundary conditions of the skid landing gear, and the loading point is located on the surface of the tubular structure skid cylinder. The technical solution is as follows: In a first aspect, a helicopter skid landing gear static test device is provided, comprising: a constraint assembly 1, a skid landing gear assembly 2, a Z-direction loading assembly 3, a Y-direction loading assembly 4, and an X-direction loading assembly 5, The skid landing gear assembly 2 is installed on the constraint assembly 1 in an inverted form, the Z-direction loading assembly 3 and the Y-direction loading assembly 4 are respectively installed at the Z-direction and Y-direction load common application points on the skid landing gear assembly 2 for the application of Z-direction and Y-direction test loads, and the X-direction loading assembly 5 is installed at the X-direction load application point on the skid landing gear assembly 2 for the application of X-direction load.

[0006] Optionally, the constraint assembly 1 comprises square columns 1a, mounting bases 1b, front connecting beams 1c, rear connecting beams 1d, positioning beams 1e, front left mounting seats 1f, front right mounting seats 1g, rear middle connecting seats 1h, front adapter blocks 1i, The square columns 1a are four, which are respectively arranged on the mounting surfaces of the four mounting bases 1b; the front connecting beams 1c and the rear connecting beams 1d respectively connect two square columns 1a to ensure the constraint positioning of the skid landing gear in the left-right direction; and the positioning beams 1e connect the front connecting beams 1c and the rear connecting beams 1d to ensure the constraint positioning of the skid landing gear in the front-rear direction. The front left mounting seats 1f and the front right mounting seats 1g are arranged on the mounting surfaces of the front connecting beams 1c, and the rear middle connecting seats 1h are arranged on the mounting surfaces of the rear connecting beams 1d; the front adapter blocks 1i are two, which are respectively arranged on the front left mounting seats 1f and the front right mounting seats 1g; the skid landing gear assembly 2 is connected with the two front adapter blocks 1i and the rear middle connecting seat 1h through three landing gear mounting points in an inverted manner; and the mounting bases 1b are fixed on the load-bearing rails.

[0007] The constraint assembly 1 is used for the constraint of the skid landing gear assembly in the skid landing gear static test, and the mounting sizes in each direction can be flexibly adjusted according to the structural characteristics of different tested skid landing gears; and the adapter structures at the mounting points of the constraint assembly 1 and the skid landing gear can flexibly and accurately simulate the real installation boundary conditions of the aircraft and the skid landing gear.

[0008] Optionally, the skid landing gear assembly 2 comprises front cross beams 2a, rear cross beams 2b, left skid cylinders 2c, right skid cylinders 2d, rubber clamps 2e, left connecting lugs 2f, right connecting lugs 2g, pivot joints 2h, and transport bolts 2i. One end of each of the front cross beams 2a and the rear cross beams 2b is connected with the front-rear connecting points of the left skid cylinders 2c and the right skid cylinders 2d respectively, and the other end is connected with the front-rear connecting points of the right skid cylinders 2d and the left skid cylinders 2c respectively; the left and right landing gear mounting points are arranged on the front cross beams 2a, and the rear middle landing gear mounting point is arranged in the middle of the rear cross beams 2b; the rubber clamps 2e, the left connecting lugs 2f and the right connecting lugs 2g are arranged at the left and right mounting points of the front cross beams 2a; the rubber clamps 2e and the pivot joints 2h are arranged at the mounting points of the rear cross beams 2b; the left connecting lugs 2f, the right connecting lugs 2g and the pivot joints 2h are the connection positions of the skid landing gear and the constraint assembly 1; and the transport bolts 2i for transporting the skid landing gear are arranged on the left skid cylinders 2c and the right skid cylinders 2d.

[0009] Optionally, the Z-axis loading assembly 3 includes: a front skid Z-axis loading clamp 3a, a screw 3b, a steel cable 3c, a triangular joint 3d, a rear skid Z-axis loading clamp 3e, and a lever 3f; There are four Z-axis loading clamps 3a on the front skid, arranged in pairs, and installed at the front loading points of the left skid 2c and right skid 2d respectively via two screws 3b. The front skid Z-axis loading clamps 3a have cable grooves, and the steel cables 3c are embedded in these grooves and connected at both ends by triangular connectors 3d. The other end of the triangular connectors 3d is connected to the hydraulic loading device 6. The rear skid Z-axis loading clamps 3e have a similar structure to the front skid Z-axis loading clamps 3a, with a total of eight rear skid Z-axis loading clamps 3e installed. Four are installed on the left skid 2c and four on the right skid 2d. Each rear skid Z-axis loading clamp 3e is a set of two rear skid Z-axis loading clamps 3e, which are connected to the skid via screws 3b. The rear skid Z-axis loading clamps 3e are provided with cable grooves, and the steel cables 3c are embedded in the cable grooves and connected at both ends by triangular connectors 3d. The other ends of the two triangular connectors 3d at the rear loading point of each skid are connected by levers 3f, and the middle position of levers 3f is connected to the hydraulic loading device 6. The front skid Z-axis loading clamps 3a and the rear skid Z-axis loading clamps 3e are tightened with nuts 3g after being connected to the skid.

[0010] Z-axis loading assembly 3 is used to apply the ground reaction load during aircraft landing to the skid landing gear. The loading positions are at the contact points on the bottom surface of the skid, totaling 4 points. During the test, the loading cable 3c at each point can rotate around the loading clamp concentric with its respective skid.

[0011] Optionally, the Y-direction loading component 4 includes: a Y-direction loading clamp 4a, a clamp-connected short beam 4c, a clamp-connected long beam 4d, a longitudinal lever 4e, a threaded sleeve 4f, a short lever 4g, and a long lever 4h; There are 16 Y-axis loading clamps 4a, installed in groups of 2, and connected to Z-axis loading clamps 3a by bolts 4b. The center of the Y-axis loading clamps 4a is located on the surface of the skid. At each loading point of the front and rear crossbeams, the two groups of Y-axis loading clamps 4a are connected by clamp connecting short beams 4c and clamp connecting long beams 4d. By measuring the angle of the side end faces of clamp connecting short beams 4c and clamp connecting long beams 4d, the installation of Y-axis loading clamps 4a around the skid can be monitored and adjusted. The Y-direction loading clamp 4a is provided with a steel cable groove. After the steel cable 3c is embedded in the steel cable groove, the two ends of the steel cable 3c are connected by the longitudinal lever 4e. The two sets of longitudinal levers 4e at each loading point of the front and rear crossbeams are respectively connected by the short lever 4g and the long lever 4h after being converted by the screw sleeve 4f. The middle position of the short lever 4g and the long lever 4h is connected to the hydraulic loading device 6.

[0012] Y-axis loading component 4 is used to apply lateral friction loads to the skid landing gear during aircraft landing. The loading direction is tangent to the bottom surface of the skid, and the positions are at the contact points on the bottom surface of the skid, a total of 4. During the test, the loading cable 3c at each point can rotate around the center of its respective Y-axis loading clamp.

[0013] Optionally, the X-direction loading component 5 includes: X-direction loading clamp 5a, connecting plate 5b, double-ear clamp 5e, front double ears 5f, rear double ears 5g, front lever 5i, and rear lever 5j; There are 8 X-axis loading clamps 5a, installed in groups of 2. Each group of X-axis loading clamps is connected to 4 connecting plates 5b by bolts 5c. The mounting hole in the middle of each connecting plate 5b is connected to the transfer bolt 2i of the skid landing gear assembly 2 and then locked with nuts 5d. After assembly, each group of X-axis loading clamps 5a will form a circular mounting groove concentric with the skid. There are 4 double-ear clamps 5e, which are respectively inserted into the grooves of the front double-ear 5f and the rear double-ear 5g and connected with small bolts 5h. The line connecting the centers of the two lugs on the front double lugs 5f and the rear double lugs 5g is tangent to the surface of the skid. The point of tangency is the position where the load is applied in the X direction. The loading position is determined by detecting the installation angle of the double lugs around the skid. The two lugs on the front double lugs 5f and the rear double lugs 5g are respectively connected to the steel cable 3c. The other end of the steel cable 3c connected to the two lugs on each set of double lugs is connected to the front lever 5i and the rear lever 5j respectively. The middle position of the front lever 5i and the rear lever 5j is connected to the hydraulic loading device 6.

[0014] X-axis loading assembly 5 is used to apply the forward and backward frictional load to the skid landing gear during aircraft landing. It is located on the bottom surface of the skid, and the direction is coaxial with the skid. There are 4 locations, which are respectively set on the transfer bolts of the skid landing gear assembly 2. During the test, the loading steel cable 3c at each location can rotate around the center of its respective X-axis loading clamp.

[0015] In a second aspect, a static test method for helicopter skid landing gear is provided, for use with any of the static test apparatuses for helicopter skid landing gear described in the first aspect, the method comprising: Step 1: Place the restraint assembly 1 in the test site with the ground rail, and fix the restraint assembly 1 to the load-bearing ground rail by test mounting feet, and install the skid landing gear assembly 2 on the restraint assembly 1 in an inverted manner; Step 2: According to the test loading requirements, load clamps of the Z-direction loading component 3, Y-direction loading component 4 and X-direction loading component 5 are installed at the Z-direction, Y-direction and X-direction load application points on the skid landing gear assembly 2 under Z-direction and Y-direction combined loading and Z-direction and X-direction combined loading conditions respectively. Step 3: According to the test loading requirements, load the Z and Y directions in combination and load the Z and X directions in combination. Connect the other end of the Z-direction loading component 3, the Y-direction loading component 4 and the X-direction loading component 5 to one end of the hydraulic loading device 6. Adjust the installation position of the other end of the hydraulic loading device 6 to the final deformation position calculated in the test, and fix it on the load-bearing structure to complete the test installation. Step 4: Apply load to the skid landing gear assembly 2 in the above state using the hydraulic loading device 6 according to the test requirements.

[0016] The beneficial effects of this invention are at least as follows: This invention can better meet the static test constraints and loading requirements of the tail skid landing gear of a 4-ton class aircraft. It simulates the actual installation boundary conditions by using an inverted installation method of the skid landing gear, which simplifies the design of the constraint device and reduces the complexity of the test installation. Through the optimized design of the loading device, the pre-installation angle of the loading device can be pre-adjusted to meet the requirement that the loading point is located on the surface of the tubular structure skid. This can effectively solve the problem of inaccurate load application caused by the self-rotation of the skid under multi-dimensional loading conditions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2 This is a structural diagram of the constraint component of the present invention.

[0019] Figure 3 This invention relates to a schematic diagram of a skid landing gear assembly.

[0020] Figure 4 This is a schematic diagram of the combined loading structure of the Z-axis loading component and the Y-axis loading component of the present invention.

[0021] Figure 5 This is a schematic diagram of the combined loading structure of the Z-axis loading component and the X-axis loading component of the present invention.

[0022] Figure 6 This is a partial detailed view of the loading structure of the Z-axis loading component and the Y-axis loading component of the present invention. Figure 7 This is a partial detailed view of the loading structure of the Z-axis loading component and the X-axis loading component of the present invention.

[0023] Among them, 1-constraint assembly; 1a-square column; 1b-mounting base; 1c-front connecting beam; 1d-rear connecting beam; 1e-positioning beam; 1f-front left mounting seat; 1g-front right mounting seat; 1h-rear center connecting seat; 1i-front adapter block; 2-skid landing gear assembly; 2a-front crossbeam; 2b-rear crossbeam; 2c-left skid; 2d-right skid; 2e-rubber clamp; 2f-left connecting lug; 2g-right connecting lug; 2h-pivot joint; 2i-transfer bolt; 3-Z-direction loading assembly; 3a-front skid Z-direction loading clamp; 3b-screw; 3c-steel cable; 3d-triangular joint; 3e-rear skid Z-direction loading clamp; 3f-lever; 3g-nut; 4-Y-direction loading assembly; 4a- Y-direction loading clamp; 4b-bolt; 4c-clamp connecting short beam; 4d-clamp connecting long beam; 4e-longitudinal lever; 4f-screw sleeve; 4g-short lever; 4h-long lever; 5-X-direction loading assembly; 5a-X-direction loading clamp; 5b-connecting plate; 5c-special bolt; 5d-special nut; 5e-double-ear clamp; 5f-front double-ear; 5g-rear double-ear; 5h-small bolt; 5i-front lever; 5j-rear lever; 6-hydraulic loading device. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0026] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited from each other.

[0027] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0028] This invention provides a static testing apparatus for helicopter skid landing gear, which has been applied to static testing of helicopter skid landing gear. Please see [link to relevant documentation]. Figure 1 The device includes a restraint assembly 1, a skid landing gear assembly 2, a Z-axis loading assembly 3, a Y-axis loading assembly 4, an X-axis loading assembly 5, and a hydraulic loading device 6.

[0029] Please see Figure 2 , Figure 3 The frame of constraint assembly 1 is composed of a square column 1a welded from profiles and steel plates, a mounting base, a front connecting beam 1c, a rear connecting beam 1d, and a positioning beam 1e. The dimensions of the frame structure can be adaptively adjusted according to different dimensions of skid landing gear. During the test, the front left mounting seat 1f and the front right mounting seat 1g, equipped with the front transition block 1i, are mounted on the mounting surface of the connecting beam 1c, and the rear center connecting seat 1h is mounted on the mounting surface of the rear connecting beam 1d. Skid landing gear assembly 2 is connected to two front transition blocks 1i and one rear center connecting seat 1h respectively through three landing gear mounting points in an inverted manner. The mounting base 1b is fixed on the load-bearing ground rail. Compared with the gantry suspension constraint method, the inverted constraint method of skid landing gear is simpler to implement and has better load-bearing capacity. Through the transition connection method of the front transition block 1i and the rear center connecting seat 1h, the boundary conditions of the actual installation of skid landing gear can be simulated more flexibly, and it has greater plasticity.

[0030] Please see Figure 3 The skid landing gear assembly 2 is a symmetrical structure, consisting of a cylindrical front crossbeam 2a, a rear crossbeam 2b, and left and right skids 2c and 2d. A front mounting point with a rubber clamp 2e, a left connecting lug 2f, and a right connecting lug 2g is provided on the front crossbeam 2a, and a rear mounting point with a rubber clamp 2e and a pivot joint 2h is provided on the rear crossbeam 2b. Simultaneously, to facilitate the movement of the skid landing gear, transfer bolts 2i are provided on the left skid 2c and right skid 2d.

[0031] Please see Figure 4 , Figure 5 , Figure 6 , Figure 7The Z-axis loading assembly 3, Y-axis loading assembly 4, and X-axis loading assembly 5 are distributed at the front and rear loading points of the left and right skids of the skid landing gear. The front and rear loading connections of a single skid are similar, and the loading connections of the left and right skids are symmetrical. The Z-axis loading assembly 3 is composed of a front skid Z-axis loading clamp 3a, a screw 3b, a steel cable 3c, a triangular joint 3d, a rear skid Z-axis loading clamp 3e, a lever 3f, and a nut 3g. The Y-axis loading assembly 4 is composed of a Y-axis loading clamp 4a, a bolt 4b, a clamp connecting short beam 4c, a clamp connecting long beam 4d, a longitudinal lever 4e, a screw sleeve 4f, a short lever 4g, and a long lever 4h. The X-axis loading assembly 5 is composed of an X-axis loading clamp 5a, a connecting plate 5b, a special bolt 5c, a special nut 5d for locking, a double-ear clamp 5e, a front double-ear clamp 5f, a rear double-ear clamp 5g, a small bolt 5h, a front lever 5i, and a rear lever 5j. During the test, the skid landing gear was subjected to combined loads in the ZY and ZX directions, and the landing gear skids would undergo translation and rotation around the skid axis due to the load.

[0032] When the skid landing gear is subjected to combined loads in the Z and Y directions, the Z-direction loading clamps 3a and 3e of the front skid and the rear skid are fixedly connected to the skid by screws 3b and nuts 3g. The Y-direction loading clamps 4a are connected to the Z-direction loading clamps 3a and 3e of the front skid and the rear skid by bolts 4b, respectively. After the connection is completed, the Y-direction loading clamps 4a at the loading points of the front and rear skids are connected by clamp connecting short beams 4c and long beams 4d. The installation position of the Y-direction loading clamps 4a is adjusted by measuring the installation angle of the clamp connecting short beams 4c and long beams 4d, so that the center position of each set of Y-direction loading clamps 4a at the initial installation is the theoretical grounding point of the skid and the ground when the test load reaches the ultimate load, so as to compensate for the Y-direction load at the ultimate load and ensure accurate load application. After the loading clamps in the Z and Y directions are installed, steel cables 3c are embedded in the corresponding clamp installation grooves. The steel cables loaded in the Z direction are connected to the hydraulic loading device 6 using triangular joints 3d, levers 3f and nuts 3g. The steel cables loaded in the Y direction are connected to the hydraulic device 6 using longitudinal levers 4e, threaded sleeves 4f, short levers 4g and long levers 4h.

[0033] When the skid landing gear is subjected to combined loads in the Z and X directions, the installation of the skid in the Z direction is the same as described above. After connecting the X-direction loading clamp 5a, connecting plate 5b, special bolt 5c, and special nut 5d to the transfer bolt 2i on the skid, the double-ear clamp 5e, front double-ear 5f, rear double-ear 5g, and small bolt 5h are installed in the mounting slots of each set of X-direction loading clamps 5a. By measuring the installation angles of the front double-ear 5f and rear double-ear 5g, the tangent point between the line connecting the centers of the two ear pieces of the double-ear 5f and rear double-ear 5g and the skid is adjusted so that the initial installation tangent point is the theoretical grounding point of the skid when the test load reaches the ultimate load, in order to compensate for the X-direction load during the ultimate load and ensure accurate load application. After completing the installation of the front double-ear 5f and rear double-ear 5g, the ear pieces of the double-ear are connected to one end of a separate steel cable 3c, and the other end of the steel cable 3c is connected to the hydraulic device 6 by merging the front lever 5i and the rear lever 5j respectively.

[0034] One embodiment of the present invention provides a method for static testing of skid landing gear. The specific implementation process is as follows: 1. The constraint assembly 1 has four square columns 1a, which are installed on the mounting surfaces of four mounting bases 1b using connecting bolts. Any two square columns 1a in the above state are connected by a front connecting beam 1c and a rear connecting beam 1d to ensure the left-right constraint positioning of the front and rear crossbeams of the skid landing gear. The front connecting beam 1c and the rear connecting beam 1d are then connected by a positioning beam 1e to ensure the front-rear constraint positioning of the front and rear crossbeams of the skid landing gear. The front left mounting seat 1f and the front right mounting seat 1g are installed on the mounting surface of the front connecting beam 1c using connecting bolts, and the rear center connecting seat 1h is installed on the mounting surface of the rear connecting beam 1d. Two front adapter blocks 1i are then installed on the front left mounting seat 1f and the front right mounting seat 1g, respectively. The four mounting bases 1b in the above state are fixed to the load-bearing ground rail with universal anchor bolts, thus completing the assembly and fixing of the constraint assembly 1. The skid landing gear assembly 2 is connected in an inverted manner to two front transition blocks 1i and a rear center connecting seat 1h through three landing gear mounting points to complete the fixation of the skid landing gear assembly 2.

[0035] 2. The Z-axis loading assembly 3 has four Z-axis loading clamps 3a on the front skid, arranged in pairs. These clamps are installed at the front loading points of the left skid 2c and right skid 2d via two screws 3b and tightened with nuts 3g. The front skid Z-axis loading clamps 3a have cable grooves. The cable 3c is embedded in the cable grooves and connected at both ends by a triangular connector 3d. The other end of the triangular connector 3d is connected to the hydraulic loading device 6. The rear skid Z-axis loading clamps 3e have a similar structure to the front skid Z-axis loading clamps 3a and are tightened with nuts 3g after installation. Due to interference between the loading point location and the skid landing gear structure, a total of eight rear skid Z-axis loading clamps 3e are installed. The left skid... Four rear skid Z-axis loading clamps 3e are installed on 2c and the right skid 2d respectively. Every two rear skid Z-axis loading clamps 3e form a group and are connected to the skid through screws 3b. The rear skid Z-axis loading clamps 3e are provided with steel cable grooves. The steel cable 3c is embedded in the steel cable groove and the two ends of the steel cable 3c are connected by triangular connectors 3d. The other ends of the two triangular connectors 3d at the rear loading point of each skid are connected by levers 3f. The middle position of the levers 3f is connected to one end of the hydraulic loading device 6. After the installation position of the other end of the Z-axis hydraulic loading device 6 is pre-adjusted to the final deformation position calculated by the test, it is fixed on the universal load-bearing ground rail to complete the installation of the Z-axis loading component 3.

[0036] 3. The Y-axis loading assembly 4 has 16 Y-axis loading clamps 4a, installed in pairs, connected to the Z-axis loading clamps 3a by bolts 4b. The center of the Y-axis loading clamps 4a is located on the surface of the skid. At each loading point of the front and rear crossbeams, the two sets of Y-axis loading clamps 4a are connected by clamps to short beams 4c and long beams 4d. The installation of the Y-axis loading clamps 4a around the skid can be monitored and adjusted by measuring the angle of the side faces of the clamps connecting the short beams 4c and the long beams 4d. The hoop 4a is equipped with a cable groove. After the cable 3c is embedded in the cable groove, the two ends of the cable 3c are connected by the longitudinal lever 4e. The two sets of longitudinal levers 4e at each loading point of the front and rear crossbeams are respectively connected by the short lever 4g and the long lever 4h after being converted by the screw sleeve 4f. The middle position of the short lever 4g and the long lever 4h is connected to one end of the hydraulic loading device 6. After the installation position of the other end of the Y-direction hydraulic loading device 6 is pre-adjusted to the final deformation position calculated by the test, it is fixed on the general load-bearing wall to complete the installation of the Y-direction loading component 4.

[0037] 4. Eight X-axis loading clamps 5a of the X-axis loading assembly 5 are installed in pairs. Each pair of X-axis loading clamps is connected to four connecting plates 5b by special bolts 5c. The mounting hole in the middle of each connecting plate 5b is connected to the transfer bolt 2i of the skid landing gear assembly 2 and then locked with special nuts 5d. After assembly, each pair of X-axis loading clamps 5a will form a circular mounting groove concentric with the skid. Four double-ear clamps 5e are placed into the groove and connected to the front double-ear clamps 5f and the rear double-ear clamps 5g by small bolts 5h. The center of the ear plates on both sides of the front double-ear clamps 5f and the rear double-ear clamps 5g are... The connecting line is tangent to the surface of the skid, and the point of tangency is the position where the X-direction load is applied. The loading position is determined by detecting the installation angle of the double ears around the skid. The two side ears of the front double ears 5f and the rear double ears 5g are respectively connected to the steel cable 3c. The other end of the steel cable 3c connected to the two side ears of each set of double ears is respectively connected to the front lever 5i and the rear lever 5j. The middle position of the front lever 5i and the rear lever 5j is connected to one end of the hydraulic loading device 6. After adjusting the installation position of the other end of the X-direction hydraulic loading device 6 to the final deformation position calculated by the test, it is fixed to the universal load-bearing wall to complete the installation of the X-direction loading component 5.

[0038] 5. The hydraulic loading device 6 is equipped with a force sensor, actuator and control system to form a closed-loop control for loading and measurement. According to the test requirements, the load is first applied to the skid landing gear assembly 2 fixed on the restraint assembly 1 in a combined loading installation state in the Z and Y directions, and then the load is applied to the skid landing gear assembly 2 fixed on the restraint assembly 1 in a combined loading installation state in the Z and X directions.

[0039] The above description merely illustrates embodiments of the present invention and is quite specific and detailed; however, it should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Furthermore, any parts of the present invention not described in detail are conventional techniques.

Claims

1. A static testing device for helicopter ski landing gear, characterized in that, include: Constraint component (1), skid landing gear component (2), Z-axis loading component (3), Y-axis loading component (4), X-axis loading component (5). The skid landing gear assembly (2) is mounted on the constraint assembly (1) in an inverted manner. The Z-direction loading assembly (3) and the Y-direction loading assembly (4) are respectively mounted on the skid landing gear assembly (2) at the common application point of the Z-direction and Y-direction loads for applying the Z-direction and Y-direction test loads. The X-direction loading assembly (5) is mounted on the skid landing gear assembly (2) at the X-direction load application point for applying the X-direction load.

2. The apparatus according to claim 1, characterized in that, The constraint assembly (1) includes: a square column (1a), a mounting base (1b), a front connecting beam (1c), a rear connecting beam (1d), a positioning beam (1e), a front left mounting seat (1f), a front right mounting seat (1g), a rear center connecting seat (1h), and a front transition block (1i). There are four square columns (1a), which are respectively set on the mounting surfaces of four mounting bases (1b); the front connecting beam (1c) and the rear connecting beam (1d) connect two square columns (1a) respectively to ensure the left and right direction constraint positioning of the skid landing gear; the positioning beam (1e) connects the front connecting beam (1c) and the rear connecting beam (1d) to ensure the front and rear direction constraint positioning of the skid landing gear. The front left mounting base (1f) and the front right mounting base (1g) are mounted on the mounting surface of the front connecting beam (1c), and the rear center connecting base (1h) is mounted on the mounting surface of the rear connecting beam (1d); there are two front transition blocks (1i), which are mounted on the front left mounting base (1f) and the front right mounting base (1g) respectively; the skid landing gear assembly (2) is connected to the two front transition blocks (1i) and the one rear center connecting base (1h) in an inverted manner through three landing gear mounting points; the mounting base (1b) is fixed on the load-bearing ground rail.

3. The apparatus according to claim 2, characterized in that, The skid landing gear assembly (2) includes: a front crossbeam (2a), a rear crossbeam (2b), a left skid (2c), a right skid (2d), a rubber clamp (2e), a left connecting lug (2f), a right connecting lug (2g), and a pivot joint (2h); One end of the front crossbeam (2a) and the rear crossbeam (2b) are connected to the front and rear connection points of the left skid (2c) respectively, and the other end is connected to the front and rear connection points of the right skid (2d) respectively. The left and right landing gear mounting points are set on the front crossbeam (2a), and the rear center landing gear mounting point is set in the middle of the rear crossbeam (2b). Rubber clamps (2e), left connecting single ears (2f) and right connecting single ears (2g) are set at the left and right mounting points of the front crossbeam (2a). Rubber clamps (2e) and pivot joints (2h) are set at the mounting points of the rear crossbeam (2b). The left connecting single ears (2f), right connecting single ears (2g) and pivot joints (2h) are the connection positions of the skid landing gear and the restraint assembly (1).

4. The apparatus according to claim 3, characterized in that, The left skid (2c) and right skid (2d) are equipped with transfer bolts (2i) for supporting the skid landing gear.

5. The apparatus according to claim 3, characterized in that, Z-direction loading assembly (3) includes: front skid Z-direction loading clamp (3a), screw (3b), steel cable (3c), triangular joint (3d), rear skid Z-direction loading clamp (3e), and lever (3f); There are four Z-axis loading clamps (3a) on the front skid, arranged in pairs, and installed at the front loading points of the left skid (2c) and right skid (2d) respectively via two screws (3b). The front skid Z-axis loading clamps (3a) have cable grooves. The cable (3c) is embedded in the cable groove, and the two ends of the cable (3c) are connected by a triangular connector (3d). The other end of the triangular connector (3d) is connected to the hydraulic loading device (6). The rear skid Z-axis loading clamps (3e) have a similar structure to the front skid Z-axis loading clamps (3a), with a total of eight rear skid Z-axis loading clamps (3e). The left skid (2c) and right skid (2d) are respectively installed with… Four rear skid Z-axis loading clamps (3e) are installed, with each pair of rear skid Z-axis loading clamps (3e) forming a group. They are connected to the skid via screws (3b). The rear skid Z-axis loading clamps (3e) are equipped with cable grooves. The steel cable (3c) is embedded in the cable grooves and the two ends of the steel cable (3c) are connected by triangular connectors (3d). The other ends of the two triangular connectors (3d) at the loading point of each skid are connected by levers (3f). The middle position of the levers (3f) is connected to the hydraulic loading device (6). The front skid Z-axis loading clamps (3a) and the rear skid Z-axis loading clamps (3e) are tightened with nuts (3g) after being connected to the skid.

6. The apparatus according to claim 5, characterized in that, The Y-direction loading component (4) includes: a Y-direction loading clamp (4a), a clamp connecting short beam (4c), a clamp connecting long beam (4d), a longitudinal lever (4e), a threaded sleeve (4f), a short lever (4g), and a long lever (4h); There are 16 Y-direction loading clamps (4a), installed in groups of 2, and connected to the Z-direction loading clamps (3a) by bolts (4b). The center of the Y-direction loading clamps (4a) is located on the surface of the skid. The two groups of Y-direction loading clamps (4a) at each loading point of the front and rear crossbeams are connected by clamp connecting short beams (4c) and clamp connecting long beams (4d). The installation of the Y-direction loading clamps (4a) around the skid can be monitored and adjusted by measuring the angle of the side end faces of the clamp connecting short beams (4c) and clamp connecting long beams (4d). The Y-direction loading clamp (4a) is provided with a cable groove. After the cable (3c) is embedded in the cable groove, the two ends of the cable (3c) are connected by the longitudinal lever (4e). The two sets of longitudinal levers (4e) at each loading point of the front and rear crossbeams are connected by the short lever (4g) and the long lever (4h) after being transferred by the screw sleeve (4f). The middle position of the short lever (4g) and the long lever (4h) is connected to the hydraulic loading device (6).

7. The apparatus according to claim 6, characterized in that, The X-axis loading component (5) includes: X-axis loading clamp (5a), connecting plate (5b), double-ear clamp (5e), ​​front double ears (5f), rear double ears (5g), front lever (5i), and rear lever (5j); There are 8 X-axis loading clamps (5a), installed in groups of 2. Each group of X-axis loading clamps is connected to 4 connecting plates (5b) by bolts (5c). The mounting hole in the middle of each connecting plate (5b) is connected to the transfer bolt (2i) of the skid landing gear assembly 2 and then locked with nuts (5d). After each group of X-axis loading clamps (5a) is assembled, a circular mounting groove concentric with the skid will be formed in the middle. There are 4 double-ear clamps (5e), ​​which are respectively inserted into the grooves of the front double ears (5f) and the rear double ears (5g) and connected with small bolts (5h). The line connecting the center of the two sides of the front double ears (5f) and the rear double ears (5g) is tangent to the surface of the skid. The point of tangency is the position where the load is applied in the X direction. The loading position is determined by detecting the installation angle of the double ears around the skid. The two sides of the front double ears (5f) and the rear double ears (5g) are connected to the steel cable (3c) respectively. The other end of the steel cable (3c) connected to the two sides of each pair of double ears is connected to the front lever (5i) and the rear lever (5j) respectively. The middle position of the front lever (5i) and the rear lever (5j) is connected to the hydraulic loading device (6).

8. A method for static testing of helicopter skid landing gear, characterized in that, The method for the static testing apparatus for helicopter skid landing gear according to any one of claims 1 to 7 comprises: Step 1: Place the constraint assembly (1) in the test site with the ground rail, and fix the constraint assembly 1 on the load-bearing ground rail by test mounting feet, and install the skid landing gear assembly (2) on the constraint assembly (1) in an inverted form; Step 2: According to the test loading requirements, load clamps of the Z-direction loading component (3), Y-direction loading component (4) and X-direction loading component (5) are installed at the Z-direction, Y-direction and X-direction load application points on the skid landing gear assembly (2) under the combined loading conditions of Z-direction and Y-direction and combined loading conditions of Z-direction and X-direction respectively. Step 3: According to the test loading requirements, load the Z and Y directions in combination and load the Z and X directions in combination. Connect the other end of the Z-direction loading component (3), the Y-direction loading component (4) and the X-direction loading component (5) to one end of the hydraulic loading device (6). Adjust the installation position of the other end of the hydraulic loading device (6) to the final deformation position calculated in the test, and fix it on the load-bearing structure to complete the test installation. Step 4: Apply load to the skid landing gear assembly (2) in the above state according to the test requirements using the hydraulic loading device (6).

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