1. A loading lever for strength test is characterized in that the loading lever comprises a bearing cross beam, an arc slide rail, a limiting pin and a steel wire rope, wherein the central line of the arc slide rail is a semi-elliptical arc line, two ends of the arc slide rail are fixed on the bearing cross beam, two elliptical focuses of the semi-elliptical arc line are positioned on the bearing cross beam, a plurality of symmetrically distributed hanging points are further arranged on the bearing cross beam, the hanging points and the two elliptical focuses on the arc slide rail are positioned on the same straight line, the limiting pin is connected on the semi-elliptical arc line of the arc slide rail, the connecting position of the limiting pin on the arc slide rail can move, two ends of the steel wire rope are respectively fixed on the bearing cross beam, fixed points at two ends of the steel wire rope are coincided with the two elliptical focuses, the length of the steel wire rope is equal to the sum of the distance between any point on the central line of the arc slide rail and the two elliptical focuses, the steel wire rope can be randomly positioned on the central line of the arc-shaped slide rail through the limiting pin, so that the steel wire rope forms a turn at the position of the limiting pin, and in addition, the traction rope applies upward traction force to the steel wire rope through the turn of the steel wire rope.

2. The loading lever for strength test of claim 1, wherein the limiting pin is provided with a through hole of the steel cable, the through hole is a three-way hole divided equally, the steel cable passes through two through holes at the lower side of the three-way hole, and the traction rope is hooked with the steel cable through the through hole above the three-way hole.

3. The loading lever for strength test of claim 1, wherein the load-bearing beam is composed of two symmetrical steel beams, two ends of the arc-shaped sliding rail are connected to one steel beam, the two steel beams are connected into an integral structure through a coaxial hole at the focus position and the focus shaft, and the mounting point is a coaxial hole distributed on the two steel beams.

4. The loading lever for strength test according to claim 1 or 2, wherein the two ends of the steel cable are connected with the two focus shafts respectively through two steel beams, the turning part of the upper end of the steel cable is connected with the arc-shaped slide rail through a limiting pin, and the plane of the steel cable is parallel to the arc-shaped slide rail and the bearing beam.

5. The loading lever for strength testing according to claim 4, wherein a plurality of connection positions of the limit pin are provided on the arc-shaped slide rail.

6. The loading lever for strength testing according to claim 5, wherein the lever ratio of the two focal positions is marked at the connecting position of each stopper pin on the arc-shaped slide rail.

7. A loading method for a strength test is characterized by comprising the following steps: 1) a loading lever using the strength test of any one of claims 1-6; 2) selecting a corresponding mounting point on the bearing cross beam according to the position of a required load action point on the strength test piece, and connecting the strength test piece to the corresponding mounting point of the bearing cross beam; 3) selecting a connecting position of a limiting pin on an arc-shaped slide rail according to the ratio of the load on the load action point required on the strength test piece, fixing the limiting pin at the connecting position, and simultaneously adjusting the length proportion of the steel wire ropes on two sides of the limiting pin; 4) the traction rope applies traction load at the bending position of the steel wire rope through the limiting pin, and the load applies load to a load action point of the strength test piece through the steel wire rope and the bearing cross beam; 5) when the load action point and the load size of the test piece are changed, the operations from item 2 to item 4 can be repeated, the load can be applied to the load action point of the strength test piece, and a new loading lever for manufacturing the strength test load is not needed; 6) in the test process, the proportion of the load applied to the load acting point can be conveniently checked through the connecting position of the limiting pin and the scale value on the arc-shaped slide rail.

Background

In some airplane structural strength tests, a plurality of load loading action points are distributed on the surface of a structure, the load loading action points are integrated into one load loading point through multi-layer combination of loading levers with different lever ratios, and then the load is applied by one hydraulic actuator. The loading lever usually determines the distance ratio between three loading points on the loading lever according to the actual load distribution condition, so that the loading point positions on the special loading lever are required for different load distribution conditions, the repeated utilization rate of the loading lever is low, the arrangement workload of the loading device is large, the test cost is increased, and the loading arrangement and inspection difficulty is also increased.

Disclosure of Invention

The invention aims to provide a loading lever and a loading method for a strength test, which can be suitable for application schemes with various load ratios and solve the problems of low repeated utilization rate and large loading arrangement and inspection workload of the loading lever in the existing airplane structure strength test.

A loading lever for strength test is characterized in that the loading lever comprises a bearing cross beam, an arc slide rail, a limiting pin and a steel wire rope, wherein the central line of the arc slide rail is a semi-elliptical arc line, two ends of the arc slide rail are fixed on the bearing cross beam, two elliptical focuses of the semi-elliptical arc line are positioned on the bearing cross beam, a plurality of symmetrically distributed hanging points are further arranged on the bearing cross beam, the hanging points and the two elliptical focuses on the arc slide rail are positioned on the same straight line, the limiting pin is connected on the semi-elliptical arc line of the arc slide rail, the connecting position of the limiting pin on the arc slide rail can move, two ends of the steel wire rope are respectively fixed on the bearing cross beam, fixed points at two ends of the steel wire rope are coincided with the two elliptical focuses, the length of the steel wire rope is equal to the sum of the distance between any point on the central line of the arc slide rail and the two elliptical focuses, the steel wire rope can be randomly positioned on the central line of the arc-shaped slide rail through the limiting pin, so that the steel wire rope forms a turn at the position of the limiting pin, and in addition, the traction rope applies upward traction force to the steel wire rope through the turn of the steel wire rope.

The limiting pin is provided with a steel wire rope through hole which is a three-way hole divided equally, the steel wire rope passes through two through holes on the lower side of the three-way hole, and the traction rope is hooked with the steel wire rope through the through hole above the three-way hole.

The bearing beam comprises two symmetrical steel beams, the two ends of the arc-shaped sliding rail are connected to the steel beam on one side, the steel beams on the two sides are connected into a whole through a coaxial hole in the focus position and a focus shaft, and the mounting points are coaxial holes in distribution on the steel beams on the two sides.

Two ends of the steel wire rope are respectively connected with the two focus shafts through the two steel beams, the turning part at the upper end of the steel wire rope is connected to the arc-shaped slide rail through a limiting pin, and the plane where the steel wire rope is located is parallel to the arc-shaped slide rail and the bearing beam.

The application also provides a loading method of the strength test, which comprises the following specific steps: 1) a loading lever using the strength test described above; 2) selecting a corresponding mounting point on the bearing cross beam according to the position of a required load action point on the strength test piece, and connecting the strength test piece to the corresponding mounting point of the bearing cross beam; 3) selecting a connecting position of a limiting pin on an arc-shaped slide rail according to the ratio of the load on the load action point required on the strength test piece, fixing the limiting pin at the connecting position, and simultaneously adjusting the length proportion of the steel wire ropes on two sides of the limiting pin; 4) the traction rope applies traction load at the bending position of the steel wire rope through the limiting pin, and the load applies load to a load action point of the strength test piece through the steel wire rope and the bearing cross beam; 5) when the load action point and the load size of the test piece are changed, the operations from item 2 to item 4 can be repeated, the load can be applied to the load action point of the strength test piece, and a new loading lever for manufacturing the strength test load is not needed; 6) in the test process, the proportion of the load applied to the load acting point can be conveniently checked through the connecting position of the limiting pin and the scale value on the arc-shaped slide rail.

The beneficial effect of this application lies in: the loading lever with the multistage adjustable lever ratio can meet the load loading and using requirements of two different ratios, can be repeatedly used, and is convenient to implement, low in cost and reliable in work.

The present application will be described in detail below with reference to the accompanying drawings of embodiments.

Drawings

Fig. 1 is a loading lever implementation 2 of the present invention: 1 lever loading schematic;

fig. 2 is a loading lever implementation 1: 1 lever loading schematic;

fig. 3 is a side view of the loading lever of the present invention.

The numbering in the figures illustrates: the test piece 1, the bearing beam 2, the arc slide rail 3, the steel wire rope 4, the limiting pin 5, the traction rope 6, the elliptical focus 7, the hanging point 8 and the focus shaft 9.

Detailed Description

Referring to the attached drawings, the loading lever for the strength test comprises a bearing cross beam 2, an arc-shaped slide rail 3, a limiting pin 5 and a steel wire 4, wherein the central line of the arc-shaped slide rail is a semi-elliptical arc line, two ends of the arc-shaped slide rail 3 are fixed on the bearing cross beam 2, two elliptical focuses 7 of the semi-elliptical arc line are located on the bearing cross beam 2, a plurality of symmetrically distributed hanging points 8 are further arranged on the bearing cross beam 2, and the hanging points 8 and the two elliptical focuses 7 on the arc-shaped slide rail are located on the same straight line.

The limiting pin 5 is connected to a semi-elliptical arc line of the arc-shaped slide rail 2, the connecting position of the limiting pin 5 on the arc-shaped slide rail 2 can move, two ends of the steel wire 4 are respectively fixed on the bearing cross beam 2, fixed points at two ends of the steel wire 4 are overlapped with two elliptical focuses 7, the length of the steel wire 4 is equal to the sum of the distance between any point on a central line of the arc-shaped slide rail and the two elliptical focuses 7, the steel wire 4 can be randomly positioned on the central line of the arc-shaped slide rail through the limiting pin 5, so that the steel wire 4 forms a turn at the position of the limiting pin 5, and the traction rope 6 applies upward traction force to the steel wire 4 through the turn of the steel wire 4.

In implementation, bearing beam 2 constitute by the girder steel of two symmetries, the both ends of arc slide rail 3 are connected on one side girder steel, connect structure as an organic whole through the coaxial hole and the focus axle 9 of focus 7 position between the girder steel of both sides, carry point 8 be located the coaxial hole of distribution on the girder steel of both sides. The arc-shaped slide rail 3 is provided with a plurality of connecting positions of limiting pins 5. The limit pins form loading levers with different proportions relative to the mounting points at different connecting positions on the arc-shaped slide rail 3, so that the loading force is distributed on the two symmetrical mounting points according to a preset proportion.

In the implementation, the limiting pin 5 is provided with a through hole of the steel wire rope 4, the through hole is a three-way hole which is divided equally, the steel wire rope 5 passes through two through holes at the lower side of the three-way hole, and the traction rope 6 is hooked with the steel wire rope 5 through the through hole at the upper side of the three-way hole.

Two ends of the steel wire 4 are connected with two focus shafts 9 through two steel beams, the turning part at the upper end of the steel wire 4 is connected to the arc-shaped slide rail 3 through a limiting pin 5, and the plane where the steel wire 4 is located is parallel to the arc-shaped slide rail 2 and the bearing beam 1.

The connecting position of each limit pin 5 on the arc-shaped slide rail 3 is marked with the lever ratio of two focus positions.

As shown in fig. 1, 2, and 3, in this embodiment, the load-bearing beam 2 is composed of two straight steel beams with groove-shaped cross sections symmetrically back to back, or may be a straight beam with other cross sections and materials, such as a square cross section, the load-bearing beam 2 is symmetrically provided with a plurality of mounting points 8 with coaxial holes, and is further symmetrically provided with a pair of coaxial holes, the hole centers of the pair of coaxial holes coincide with the geometric positions of the elliptic focus 7 of the elliptic center line of the arc-shaped slide rail 3, so as to adapt to different positions of the load-bearing points 8, and the number of the load-bearing point shaft holes on the load-bearing beam 2 is three in this embodiment. The arc-shaped slide rail 3 is fixed on a straight steel beam with a groove-shaped cross section on one side of the bearing beam 2, the plane of the arc-shaped slide rail 3 is parallel to the symmetrical plane of the bearing beam 2, and scale marks and specific values are marked on the arc-shaped slide rail 3. Two ends of the steel wire 4 are fixed on hole positions on the bearing beam 2 through a focus shaft 9, and the hole positions are superposed with an elliptic focus 7 of an elliptic central line of the arc-shaped slide rail 3. The limiting pin 5 is arranged on the arc-shaped slide rail 3 and can move along the oval central line of the arc-shaped slide rail 3, three through holes which are equally divided are arranged on the limiting pin 5, the steel wire rope 4 passes through the two through holes on the limiting pin 5, and the traction rope 6 passes through one through hole on the limiting pin 5 and is hooked with the steel wire rope 4. An external load is applied to the steel wire rope 4 through the traction rope 6, the steel wire rope 4 is tightened to form a triangular state, two angular points are the focus 7 positions of an ellipse on the bearing cross beam 2, and the third angular point is any point on the center line of the ellipse of the arc-shaped slide rail 3. The limiting pin 5 is positioned and locked on the arc-shaped slide rail 3 according to the load ratio of the two load acting points on the machine body structure 7. The test piece 1 of the body structure is hung on two symmetrical loading points 8 on the bearing beam 2 through a connecting rope.

The loading lever device with the multistage adjustable lever ratio can be adjusted according to the load distribution proportion, can realize the reutilization of the loading lever, can conveniently arrange the test loading lever, and is convenient to check the load distribution proportion of the loading point. The working process is as follows:

an external load 'F' vertical to the bearing cross beam is applied to the traction rope 6, the limiting pin 5 is moved to reach the scale line of the value according to the load size ratio of two points on the machine body structure test piece 1, and then the limiting pin 5 is fixed on the arc-shaped slide rail 3, so that the load application to the machine body is completed. The load distribution proportion of each layer can be conveniently checked through a scale on the arc-shaped slide rail 3.

The above description is only for the best mode of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.