Crank lever fatigue test device

Abstract

The utility model belongs to the technical field of helicopter curved bar fatigue test, and relates to a curved bar fatigue test device. Comprising a rack, a vertical loading mechanism and a restraining mechanism, the rack is fixed on the ground; the rack comprises an upper bottom plate, a lower bottom plate and square steel stand columns connected with the upper bottom plate and the lower bottom plate. One end of the vertical loading mechanism is connected with the rack lower bottom plate, and the other end passes through the rack upper bottom plate and is connected with two ends of the curved bar; and the restraining mechanism is fixed on the upper bottom plate of the rack and is connected with the middle part of the curved bar.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of helicopter curved rod fatigue test, and relates to a curved rod fatigue test device. BACKGROUND

[0002] As an important standard device of main blade, the curved rod is mainly used for load transmission and the like. The curved rod is a key structural member connecting the bearingless flexible beam and the flapping arm of the helicopter. During the operation of the blade, the curved rod bears the complex load transmitted by the flapping arm, and the fatigue performance of the curved rod directly affects the service life of the curved rod and the normal operation of the main blade. In order to explore the fatigue performance of the curved rod of the helicopter, the fatigue test of the curved rod needs to be carried out on the ground, so as to determine the fatigue failure mode and the dangerous position of the curved rod. SUMMARY

[0003] The utility model discloses a curved rod fatigue test device, which solves the problem of lack of helicopter curved rod fatigue test device and evaluation of fatigue life.

[0004] TECHNICAL SCHEME

[0005] A curved rod fatigue test device, comprising: a rack, a vertical loading mechanism and a constraint mechanism.

[0006] The rack is fixed on the ground.

[0007] The rack comprises an upper bottom plate, a lower bottom plate and square steel columns connecting the upper and lower bottom plates.

[0008] One end of the vertical loading mechanism is connected with the lower bottom plate of the rack, and the other end is connected with both ends of the curved rod through the upper bottom plate of the rack.

[0009] The constraint mechanism is fixed on the upper bottom plate of the rack, and the constraint mechanism is connected with the middle part of the curved rod.

[0010] Further, the vertical loading mechanism comprises an actuator support, an actuator, a loading rod, a loading joint and two left and right fork ears.

[0011] The actuator support is fixed on the lower bottom plate, and the actuator is hinged on the actuator support.

[0012] The loading joint is in the shape of U, and the two outer sidewalls are connected with the left and right fork ears through bolts.

[0013] The left and right fork ears are connected with both ends of the curved rod through bolts.

[0014] Further, a sensor is arranged on the output shaft of the actuator.

[0015] Further, protrusions are arranged on the left and right fork ears, and the protrusions are matched with notches at both ends of the curved rod to constrain the rotation freedom degree of the curved rod.

[0016] Further, the constraint mechanism comprises a fixed end support, a fixed end yoke, a flexible beam prosthesis, a joint bearing bushing, a positioning bushing and a positioning bolt;

[0017] The fixed end support is installed above the upper bottom plate; the fixed end yoke is provided with a flange plate structure at one end and is connected with the fixed end support; the other end of the fixed end yoke is a double ear structure and is connected with the flexible beam prosthesis through bolts;

[0018] The middle part of the flexible beam prosthesis is provided with the joint bearing bushing; the joint bearing bushing is internally provided with the positioning bushing and the positioning bolt; and the middle part of the curved rod is connected through the positioning bolt.

[0019] Further, the positioning bolt is used for constraining the horizontal freedom degree of the curved rod.

[0020] In summary, the beneficial effects of the present application are as follows:

[0021] The curved rod fatigue test device designed in the present application can accurately simulate the boundary conditions and load characteristics of the curved rod of a helicopter and realizes the examination of the fatigue performance test of the curved rod. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 Fig. 1 is a structural schematic view of a curved rod fatigue test device.

[0023] Figure 2 Fig. 2 is a schematic view of a rack structure.

[0024] Figure 3 Fig. 3 is a structural view of a vertical loading mechanism.

[0025] Figure 4 Fig. 4 is a schematic view of left and right yokes.

[0026] Figure 5 Fig. 5 is a schematic view of a loading rod.

[0027] Figure 6 Fig. 6 is a schematic view of a constraint mechanism. DETAILED DESCRIPTION

[0028] In order to enable personnel in the technical field to better understand the present application, the technical solutions in the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application.

[0029] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "transverse", "longitudinal" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0030] In addition, the terms "mount", "set", "provided with", "connect", "connect", "socket" should be broadly understood. For example, it can be fixedly connected, detachably connected, or integrally constructed; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, or it can be internal communication between two devices, elements or components. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0031] As shown in Figures 1-6 The present application is a kind of curved rod fatigue test device, by rack 1, vertical loading mechanism 2, curved rod, restraint mechanism 3 is composed, vertical loading mechanism 2 is fixed to rack 1 by bolt, curved rod is installed to restraint mechanism 3 by positioning bolt, simultaneously curved rod is connected with vertical loading mechanism 2 by two end threads and self-locking nut, ensure that curved rod vertical load is stably and reliably loaded to two ends of curved rod.

[0032] Rack 1 is composed of lower bottom plate 1-1, square steel column 1-2 and upper bottom plate 1-3. The rack 1 is fixed by welding the lower bottom plate 1-1, the square steel column 1-2 and the upper bottom plate 1-3, and then the positioning and processing of the mounting hole are carried out, which can improve the machining precision of the rack and ensure that the machining precision of the rack meets the design precision requirements.

[0033] The vertical loading mechanism 2 is composed of actuator support 2-1, actuator, sensor, loading rod 2-2, loading connector 2-3, left fork ear 2-4 and right fork ear 2-5.

[0034] The vertical loading mechanism 2 is fixed to the rack 1 by the actuator support 2-1 and the bolt, the hexagonal stepped end of the loading rod 2-2 is connected with the sensor, the cylindrical stepped end passes through the loading connector 2-3 and is fixed by tightening the nut, the double-hole mounting surface of the left fork ear 2-4 and the right fork ear 2-5 is fixed to the left and right ends of the loading connector 2-3 by bolts respectively, and the single-hole mounting surface of the left fork ear 2-4 and the right fork ear 2-5 is connected with the two ends of the curved rod by bolts, to realize the accurate installation of the curved rod and the vertical loading mechanism 2.

[0035] The loading joint 2-3 adopts a U-shaped structure design, two walls of the U-shaped structure adopt thin wall design, and the U-shaped depth is deepened, which not only satisfies smooth installation of left and right yokes, but also satisfies that the rigidity of the loading joint 2-3 is consistent with the installed state, so that the vertical load is effectively transmitted to the curved rod, and the test loading precision is improved.

[0036] The single-hole mounting surface of the left yoke 2-4 and the right yoke 2-5 is processed with a protrusion, the protrusions of the left yoke 2-4 and the right yoke 2-5 are respectively assembled with notches at two ends of the curved rod in the installation process, the rotation freedom of the curved rod along the curved rod axis is constrained, the stability of the installation state of the curved rod in the test process is ensured, the vertical load is stably and accurately applied to the curved rod, and the load transmission relationship of the curved rod is truly simulated.

[0037] The constraint mechanism 3 is composed of a fixed end support 3-1, a fixed end yoke 3-2, a flexible beam dummy 3-3, a joint bearing bush 3-4, a positioning bush 3-5 and a positioning bolt 3-6.

[0038] The constraint mechanism 3 is bolted to the rack 1 through the fixed end support 3-1, the fixed end yoke 3-2 is connected with the fixed end support 3-1 through a flange plate structure and a bolt, the flexible beam dummy 3-3 is connected with the fixed end yoke 3-2 through a bolt, the flexible beam dummy 3-3 is connected with the curved rod through the joint bearing bush 3-4, the positioning bush 3-5 and the positioning bolt 3-6, the translational freedom of the middle of the curved rod is constrained, the rotational freedom of the middle of the curved rod is reserved, the vertical load is accurately and reliably applied, and the test loading precision is improved.

[0039] The fixed end yoke 3-2 is connected with the fixed end support 3-1 through a boss and a flange plate structure, the accurate and stable installation of the fixed end yoke 3-2 and the fixed end support 3-1 is realized through the positioning effect of the boss. The fixed end yoke 3-2 adopts a shaft hollow design, the lightweight design of the connecting part is realized under the requirement of meeting the strength, and the convenience of installation is realized.

[0040] During the test, the boundary conditions of the test piece can be accurately simulated, the test bench is stable, the test environment is good, the load fluctuation is small, the total error of the test can be controlled within 3% by adopting the device, and the test data obtained by adopting the device can be used for life analysis, and the performance can be fully verified.

[0041] The above only describes the preferred embodiments of the application and is not used to limit the application, and the application can have various changes and modifications for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A crooked bar fatigue testing apparatus, characterized by: The utility model relates to a vertical loading mechanism and a constraint mechanism for a test bench. The test bench is fixed on the ground. The test bench comprises an upper base plate, a lower base plate and square steel columns connecting the upper and lower base plates. One end of the vertical loading mechanism is connected to the lower base plate of the test bench, and the other end is connected to both ends of the curved rod through the upper base plate of the test bench. The constraint mechanism is fixed on the upper base plate of the test bench, and the constraint mechanism is connected to the middle part of the curved rod. The vertical loading mechanism comprises an actuator support, an actuator, a loading rod, a loading joint and two left and right fork ears.

2. The apparatus of claim 1, wherein: The actuator support is fixed on the lower base plate, and the actuator is hinged to the actuator support. The output shaft of the actuator is connected to the loading joint through the loading rod. The loading joint is in the shape of a U, and the two outer walls are connected to the left and right fork ears through bolts. The left and right fork ears are connected to both ends of the curved rod through bolts.

3. The apparatus of claim 2, wherein: A sensor is arranged on the output shaft of the actuator.

4. The apparatus of claim 3, wherein: The left and right fork ears are provided with protrusions which are matched with the notches at both ends of the curved rod to constrain the rotational freedom of the curved rod.

5. The apparatus of claim 4, wherein: The constraint mechanism comprises a fixed end support, a fixed end fork ear, a flexible beam prosthesis, a joint bearing bushing, a positioning bushing and a positioning bolt. The fixed end support is installed above the upper base plate. The fixed end fork ear is provided with a flange structure at one end and is connected to the fixed end support. The other end of the fixed end fork ear is in the shape of a double ear structure and is connected to the flexible beam prosthesis through bolts.

6. The apparatus of claim 5, wherein: The middle part of the flexible beam prosthesis is provided with the joint bearing bushing. The positioning bushing and the positioning bolt are installed in the joint bearing bushing and are connected to the middle part of the curved rod through the positioning bolt. The positioning bolt is used to constrain the horizontal freedom of the curved rod.

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