CN215640541U

CN215640541U - Clamping device for testing tensile fatigue performance of nut column welding joint

Info

Publication number: CN215640541U
Application number: CN202121165129.XU
Authority: CN
Inventors: 付雷; 孙响; 王浩浩; 方荣超
Original assignee: Xuzhou XCMG Excavator Machinery Co Ltd
Current assignee: Xuzhou XCMG Excavator Machinery Co Ltd
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2022-01-25
Anticipated expiration: 2031-05-28

Abstract

The utility model discloses a clamping device for testing the tensile fatigue performance of a nut column welding joint, which comprises an upper body, a lower body and a welding joint movably arranged between the upper body and the lower body, wherein the clamping device is movably arranged on a universal clamping mechanism through the upper body and the lower body, the universal clamping mechanism is an integrally formed two-section stepped cylinder, and a third screw hole of the cylinder is formed in the position with a small diameter along the axial direction; the utility model can realize that the fatigue testing machine directly measures the fatigue strength of the welded joint of the nut column and perfects a fatigue performance evaluation system by arranging the upper body and the lower body to clamp the welded joint of the nut column on the universal clamping structural member; go up body, lower body and screw fastening nut post welded joint simultaneously, have simple structure, clamping precision height, firm in connection's advantage.

Description

Clamping device for testing tensile fatigue performance of nut column welding joint

Technical Field

The utility model relates to a clamping device for testing the tensile fatigue performance of a nut column welding joint, and belongs to the technical field of tool fixtures.

Background

In the method for detecting the mechanical properties of the material, a tensile test is a common test method, and a fatigue tensile test is used for testing the mechanical properties of the material under the action of a long-time dynamic load. The tensile clamp of the fatigue tensile testing machine is generally divided into various structural types such as a spiral type, a butt clamp type, a jaw type and the like.

Meanwhile, in enterprise production, the nut column and the bottom plate are welded by adopting stud welding, MIG welding, TIG welding, shielded metal arc welding and other welding methods. The test methods for the mechanical properties of the welded joint of the nut stud are generally divided into a torsion test, a tensile test and a bending test. The torque testing method is to measure the torque of the nut column by a digital display torque wrench torsion stud. And the tensile test is carried out according to the GB/T228 rule, the nut column is stretched along the axial direction until the nut column is broken, and if the fracture does not occur in the welding seam and the heat affected zone, the mechanical property of the welding joint is considered to be good. The bending test is mainly aimed at a nut column with the diameter of less than 22mm, and the nut column is bent by hammering or bending by a sleeve to be 30 degrees, and if no macroscopic cracks exist in a welding seam and a heat affected zone, the bending resistance of the joint is considered to be good. The testing method is lack of fatigue tensile test aiming at the capacity of bearing dynamic load, the fatigue tensile testing machine is mainly different from a universal testing machine in that reciprocating alternate cyclic load is provided, the screw thread of the nut column is easy to loosen and fall off under the action of the cyclic load, and at present, the fatigue performance evaluation of the welding joint of the nut column is indirectly carried out through the expression of other mechanical properties such as torsion, stretching, bending and the like. Generally, if the static load strength of the welded joint is high and the ductility and toughness are good, the fatigue performance is considered to be qualified, and the fatigue strength of the nut column welded joint is not directly measured.

The existing nut column welding joint fatigue performance evaluation system is imperfect, and a method capable of directly measuring the fatigue strength is lacked. Usually, a fatigue testing machine is adopted to measure the fatigue strength of the material, and the welded joint of the nut column cannot be directly clamped to the clamping end of the fatigue testing machine.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects in the prior art, provides the clamping device for testing the tensile fatigue performance of the nut column welding joint, and can realize the direct measurement of the fatigue strength of the nut column welding joint by the fatigue testing machine.

In order to solve the technical problems, the utility model is realized by adopting the following technical scheme:

the utility model provides a clamping device of tensile fatigue performance test of nut post welded joint, includes body, lower body and movable mounting last body and the welded joint between the body down, clamping device is through last body and lower body movable mounting on general fixture, two segmentation echelonment cylinders of general fixture as an organic whole formation, the diameter is little to be opened along the axis direction has the third screw of cylinder.

Furthermore, the welding joint comprises a nut column and a joint bottom plate, the joint bottom plate is connected with the nut column through a welded seam, and the joint bottom plate is a cylinder.

Furthermore, a first cylindrical screw hole is formed in the nut column along the axis direction; the outer end of the joint bottom plate is provided with a first external thread.

Further, the upper body is a three-section stepped cylinder with the diameter sequentially reduced, a second external thread is arranged at the outer end of the cylinder with the largest diameter, and the second external thread is matched with a screw hole of the universal clamping mechanism; and a third external thread is arranged at the outer end of the cylinder with the smallest diameter and is matched with the first screw hole.

Further, the cylinders of the upper body in the three-section form are connected through arc-shaped connecting parts, and the radius of each arc is not smaller than that of each adjacent cylinder.

Furthermore, the lower body is a two-section stepped cylinder with the diameter reduced, a cylindrical second screw hole is formed in the cylinder with the large diameter along the axis direction, and the second screw hole is matched with a first external thread arranged at the outer end of the joint bottom plate; and the outer end of the cylinder with the small diameter is provided with a fourth external thread, and the fourth external thread is matched with a screw hole of the universal clamping mechanism.

Furthermore, the upper body and the lower body are both made of No. 45 quenched and tempered steel, and the hardness is 20-30 HRC.

Compared with the prior art, the utility model has the following beneficial effects:

(1) the universal clamping structural part is provided with the upper body and the lower body clamping nut column welding joint, so that the fatigue testing machine can directly measure the fatigue strength of the nut column welding joint, and a fatigue performance evaluation system is perfected;

(2) the nut column welding joint is fastened through the upper body, the lower body and the screw hole, so that the nut column welding joint has the advantages of simple structure, high clamping precision and firm connection;

(3) the utility model can adapt to different specifications of the nut column and the thickness of the test board by adjusting the thread fit size of the upper body and the lower body;

(4) the upper body and the lower body can be recycled, so that the upper body and the lower body are convenient to disassemble and assemble, and the cost can be reduced.

Drawings

FIG. 1 is an assembly structural view of a holding jig in embodiment 1 of the present invention;

FIG. 2 is a front view of an upper body in embodiment 1 of the present invention;

FIG. 3 is a front view of a lower body in embodiment 1 of the present invention;

FIG. 4 is a front view of a welded joint of a nut stud in embodiment 1 of the present invention;

FIG. 5 is a front view of a universal clamping mechanism in embodiment 1 of the utility model;

fig. 6 is a view showing a fatigue test assembly structure in embodiment 1 of the present invention.

In the figure: 1, an upper body; 11 a connecting part; 12 a second external thread; 13 a third external thread; 2, a lower body; 21 a second screw hole; 22 a fourth external thread; 3, welding a joint of the nut column; 31 a nut post; a 32 splice backplane; 33 welding seams; 34 a first screw hole; 35 a first external thread; 4, a universal clamping mechanism; 41 third screw hole.

Detailed Description

The utility model is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

Example 1

As shown in fig. 1, a clamping device for a tensile fatigue performance test of a nut stud welded joint comprises an upper body 1, a lower body 2 and a welded joint 3 capable of being movably mounted between the upper body 1 and the lower body 2, wherein the upper body 1 and the lower body 2 are used as a transition device for indirect clamping and are movably mounted on a universal clamping mechanism 4 of a fatigue testing machine, the universal clamping mechanism 4 is shown in fig. 5, the universal clamping mechanism 4 is a two-section stepped cylinder which is integrally formed, and a third screw hole 41 of the cylinder is formed in a position with a small diameter along the axial direction.

The welding joint 3 shown in fig. 4 comprises a nut column 31 and a joint bottom plate 32, wherein the nut column 31 and the joint bottom plate 32 are connected by welding, and a welding seam 33 is formed; the joint bottom plate 32 is a cylinder, and a first cylindrical screw hole 34 is arranged inside the nut column 31 along the axial direction; the outer end of the joint base plate 32 is provided with a first external thread 35.

As shown in fig. 2, the upper body 1 is a three-section stepped cylinder with successively decreasing diameters, the three-section cylinders of the upper body 1 are connected by arc-shaped connecting parts 11, the radius of each arc is not smaller than that of an adjacent cylinder, a second external thread 12 is arranged at the outer end of the cylinder with the largest radius diameter in the upper body 1, and the second external thread 12 is matched with a screw hole 41 of the universal clamping mechanism 4; the outer end of the cylinder with the smallest diameter is provided with a third external thread 13, and the third external thread 13 is matched with the first screw hole 34.

As shown in fig. 3, the lower body 2 is a two-section stepped cylinder with a reduced diameter, a second cylindrical screw hole 21 is formed in the cylinder with a large diameter along the axial direction, and the second screw hole 21 is matched with a first external thread 35 formed at the outer end of the joint bottom plate 32; the outer end of the cylinder with the small diameter is provided with a fourth external thread 22, and the fourth external thread 22 is matched with the screw hole 41 of the universal clamping mechanism 4.

The upper body 1 and the lower body 2 are both made of No. 45 quenched and tempered steel, and are quenched and tempered to have the hardness of 20-30 HRC.

In the manufacturing process of the welding joint 3, the nut column 31 is welded on the surface of the joint base plate 32 to form a welding seam 33, then the welding joint base plate 32 is processed into a cylinder, and finally the thread 35 is processed on the outer surface of the cylinder to ensure the coaxiality requirement of the whole clamping device.

As shown in fig. 1 and 6, at the time of assembly, the third external thread 13 of the upper body 1 and the first screw hole 34 of the nut stud weld joint 3 are fastened by screw connection according to the screw threads and screw holes adapted in the above embodiment, and then are reinforced by spot welding at the screw-fastened position; the first male screw 35 on the joint base plate 32 is then fastened to the second screw hole 21 of the lower body 2 by screw coupling, and then spot welding is performed at the screw-fastened position to complete the assembly of the clamping device.

After the assembly of the clamping device is completed, the second external thread 12 of the upper body 1 is fastened with the third screw hole 41 of the universal clamping mechanism 4 through threaded connection, the fourth external thread 22 of the lower body 2 is fastened with the third screw hole 41 of the other universal clamping mechanism 4 through threaded connection, the whole device is installed on a fatigue testing machine, the assembly of a fatigue test is completed, and the tensile fatigue test can be performed.

After the fatigue test is finished, the tensile sample is screwed out of the upper chuck and the lower chuck of the fatigue machine, the spot welding seam 33 at the thread fastening position is cut off by an angle grinder, and the detached upper body 1 and the detached lower body 2 can be repeatedly used.

In another embodiment, the relative positions of the upper body 1, the lower body 2 and the nut column welding joint 3 are rotated by 180 degrees, namely the whole clamping device is inverted, and the tensile fatigue performance test of the nut column welding joint can also be realized.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims

1. The utility model provides a clamping device of tensile fatigue performance test of nut post welded joint, includes general fixture, its characterized in that still includes body, lower body and movable mounting at last body and the welded joint between the body down, clamping device is through last body and lower body movable mounting on general fixture, two segmentation echelonment cylinders that general fixture is as an organic whole formed, and the diameter is little to be located to open along the axis direction has the third screw of cylinder.

2. A clamping device for tensile fatigue testing of a welded joint of a nut post as defined in claim 1, wherein said welded joint comprises a nut post, a joint base plate, said joint base plate being connected to said nut post by a welded seam, said joint base plate being a cylinder.

3. The clamping device for tensile fatigue performance testing of the welded joint of the nut post as recited in claim 2, characterized in that a first threaded hole in the shape of a cylinder is provided along the axial direction inside the nut post; the outer end of the joint bottom plate is provided with a first external thread.

4. The clamping device for the tensile fatigue performance test of the welded joint of the nut post as recited in claim 3, characterized in that the upper body is a three-section stepped cylinder with successively decreasing diameters, the outer end of the cylinder with the largest diameter is provided with a second external thread, and the second external thread is matched with the screw hole of the universal clamping mechanism; and a third external thread is arranged at the outer end of the cylinder with the smallest diameter and is matched with the first screw hole.

5. The clamping device for the tensile fatigue performance test of the welded joint of the nut stud as recited in claim 4, wherein the three-segment cylinders of the upper body are connected by circular arc-shaped connecting parts, and the radius of each circular arc is not smaller than that of the adjacent cylinder.

6. The clamping device for the tensile fatigue performance test of the welded joint of the nut column as recited in claim 3, wherein the lower body is a two-section stepped cylinder with a reduced diameter, a second cylindrical screw hole is formed in the cylinder with a larger diameter along the axial direction, and the second screw hole is matched with a first external thread formed at the outer end of the joint bottom plate; and the outer end of the cylinder with the small diameter is provided with a fourth external thread, and the fourth external thread is matched with a screw hole of the universal clamping mechanism.

7. The clamping device for the tensile fatigue performance test of the welded joint of the nut post as claimed in claim 1, wherein the upper body and the lower body are both made of No. 45 quenched and tempered steel, and the hardness is 20-30 HRC.