WO2015135329A1

WO2015135329A1 - Fatigue testing device for pulsation fatigue testing machine and pulsation fatigue testing machine

Info

Publication number: WO2015135329A1
Application number: PCT/CN2014/090379
Authority: WO
Inventors: 王贵国; 郭云健; 燕春光; 陈伟; 黄少东; 刘霞
Original assignee: 唐山轨道客车有限责任公司
Priority date: 2014-03-14
Filing date: 2014-11-05
Publication date: 2015-09-17
Also published as: CN103837420B; CN103837420A

Abstract

A fatigue testing device for a pulsation fatigue testing machine and the pulsation fatigue testing machine. The fatigue testing device comprises a force transfer plate (1) and a support column (2) fixed on a working platform (3), wherein a pre-set part of the force transfer plate (1) is hinged with the support column (2), and the two ends of the force transfer plate (1) can swing up and down around the support column (2); and clamps (5, 6) are respectively arranged at one end of the force transfer plate (1) and on the working platform (3) and are used for connecting the two ends of a workpiece (7) to be stretched, and an actuator (4) is arranged at the other end of the force transfer plate (1), so that the other end of the force transfer plate (1) stretches the workpiece (7) to be stretched when the actuator (4) applies an acting force to one end of the force transfer plate (1) under the control of a control system. The fatigue testing device for a pulsation fatigue testing machine and the pulsation fatigue testing machine can perform the tension fatigue test on small specimens. The test range of the pulsation fatigue testing machine can be expanded when the fatigue testing device is applied to the pulsation fatigue testing machine.

Description

Fatigue test device and pulsation fatigue tester for pulsating fatigue tester

Technical field

The invention relates to a fatigue testing technology for mechanical parts, in particular to a fatigue testing device for a pulsating fatigue testing machine and a pulsating fatigue testing machine.

Background technique

In modern industry, corrosion, fracture and wear are the main causes of failure of mechanical parts and engineering components. The corrosion and wear processes are slow. They can be avoided by regularly replacing parts or repairing regularly, but the breaks often occur suddenly. Foresee. There are many reasons for the fracture of parts, such as overload, low temperature brittleness, hydrogen embrittlement, stress corrosion and fatigue, and the actual engineering results show that most of them are caused by fatigue.

Therefore, in order to avoid the damage caused by fatigue fracture, the strength of the new equipment designed or the strength check of the equipment during operation, it is necessary to test the fatigue of the components under different alternating stresses. performance.

In the prior art, the common equipment for performing the fatigue test is a hydraulic pulsation fatigue tester, but the pulsation fatigue tester can only be used for one-way pulsation compression or bending fatigue test on various large parts and structures, but cannot be realized small. The tensile fatigue test of the specimen is greatly limited in the test range.

Summary of the invention

The present invention provides a fatigue tester for a pulsation fatigue tester and a pulsation fatigue tester, which is capable of performing a tensile fatigue test of a small sample and expanding the test range of the pulsation fatigue tester.

The invention provides a fatigue testing device for a pulsation fatigue testing machine, comprising a force transmission plate and a support column fixed on the working platform, wherein a predetermined portion of the force transmission plate is hingedly connected with the support column, and the force transmission plate Both ends can swing up and down around the support column;

One end of the force transmission plate and the working platform are respectively provided with clamps for connecting two ends of the workpiece to be stretched, and the other end of the force transmission plate is provided with an actuator for the actuator When a force is applied to one end of the force transmission plate under the control of the control system, the other end of the force transmission plate stretches the workpiece to be stretched.

The present invention also provides a pulsation fatigue testing machine, comprising the fatigue testing device for a pulsating fatigue testing machine as described above

The fatigue test device and the pulsation fatigue tester for the pulsation fatigue tester provided by the present invention are provided by the force transmission plate and the support column hingedly connected with the force transmission plate, so that the actuator acts on one end of the force transmission plate, The workpiece at the other end of the force transmission plate is subjected to a tensile test. The device is capable of performing a tensile fatigue test on a small sample and is applied to a pulsation fatigue tester to expand the pulsation fatigue test and the test range.

DRAWINGS

1 is a schematic structural view of a fatigue testing device for a pulsation fatigue testing machine of the present invention;

Figure 2 is an enlarged view of A in Figure 1;

3 is a schematic structural view of a force transmission plate in a fatigue testing device for a pulsation fatigue testing machine of the present invention;

4 is a schematic structural view showing a support column disposed on a working platform in a fatigue testing device for a pulsation fatigue testing machine according to the present invention;

5 is a schematic structural view of a jig in a fatigue testing device for a pulsation fatigue testing machine of the present invention;

6 is a schematic structural view of a joint bearing in a fatigue testing device for a pulsation fatigue testing machine of the present invention;

Fig. 7 is a schematic view showing the installation of the joint bearing on the force transmission plate in the fatigue test device for the pulsation fatigue tester of the present invention.

detailed description

The embodiment of the present invention provides a fatigue testing device for a pulsating fatigue testing machine. As shown in FIG. 1 , the fatigue testing device includes a force transmitting plate 1 and a supporting column 2 fixed on the working platform 3, and a predetermined portion of the force transmitting plate 1 The two ends of the force transmission plate 1 are swingable up and down around the support column 2; one end of the force transmission plate 1 and the working platform 3 are respectively provided with clamps for connecting the two ends of the workpiece to be stretched, The other end of the force transmission plate 1 is provided with an actuator 4, so that when the actuator 4 applies a force to one end of the force transmission plate 1 under the control of the control system, the other end of the force transmission plate The workpiece to be stretched is stretched.

Wherein, the force transmitting plate 1 plays a role here to achieve the transmission and conversion of the force, and the downward pressure exerted by the actuator 4 on one end of the force transmission plate 1 is transmitted to the other end, and is converted into a tensile force to the workpiece. Thus, the workpiece can be subjected to a tensile fatigue test.

In order to facilitate the transmission and conversion of force, the force transmission plate 1 is required to transmit force under the premise that the minimum deflection deformation (which is negligible for the test), so the force transmission plate 1 needs to be selected with suitable materials and design. If the rigidity of the selected material is too small, the force transmitting plate itself will undergo flexural deformation during the force transmission, and the force cannot be completely transmitted to the tensile test piece, so the stretching of the test piece is difficult to achieve. If the length of the force transmission plate is too long, the problem of flexural deformation will also occur, which is not conducive to the transmission of force.

In this embodiment, the force transmission plate 1 is hingedly connected to the support column 2 on the work platform 3, as shown in FIG. 3 and FIG. 4, a semi-cylindrical protrusion 11 is provided at a predetermined portion of the force transmission plate 1 to support The column 2 is provided with a semi-cylindrical recess 21 cooperating with the semi-cylindrical projection 11, the semi-cylindrical projection 11 being disposed in the semi-cylindrical recess 21, and the semi-cylindrical projection 11 passing through the pin and the semi-cylindrical The side walls on both sides of the groove 21 are connected, thereby achieving an articulated connection of the force-transmitting plate 1 and the support column 2. In this embodiment, a semi-cylindrical protrusion 11 is disposed on the force transmission plate 1 and a semi-cylindrical groove 21 is disposed on the support column 2 for facilitating the assembly of the force transmission plate 1 and the support column 2, and during the test, This is more advantageous for the rotation of the force transmission plate 1.

During the relative rotation of the force transmission plate 1 and the support column 2, there is a problem of wear. In order to reduce the contact wear between the force transmission plate 1 and the support column 2, the semi-cylindrical projection 11 of the embodiment of the force transmission plate 1 is used. A ball is disposed between the semi-cylindrical groove 21 of the support column 2 to reduce friction by the ball, and a lubricating oil may be added between the semi-cylindrical protrusion 11 and the semi-cylindrical groove 21 Reduce friction.

In order to facilitate the tensile fatigue performance of the test piece, the position of the semi-cylindrical protrusion 11 of the force transmission plate 1 is disposed at the middle portion of the force transmission plate 1 so that the intermediate portion of the force transmission plate 1 is hingedly connected with the support table 2, so that The two ends of the force transmission plate 1 are the same distance from the intermediate portion. According to the principle of the lever, the force values at both ends of the force transmission plate 1 are the same, that is, the pressure exerted on the force transmission plate 1 by the actuator 4 and the pulling of the workpiece. The same strength.

In this embodiment, the working platform 3 and the end of the force transmitting plate 1 connected to the workpiece to be stretched are respectively connected with a clamp, as shown in FIG. 2, the upper clamp 5 is connected to the force transmission plate 1, and the working platform 3 is connected. There is a lower clamp 5', and both ends of the workpiece 7 to be stretched are respectively clamped and fixed by the upper clamp 5 and the lower clamp 5'. The upper clamp 5 and the lower clamp 5' in this embodiment have the same structure and are all plate-shaped. As shown in FIG. 5, the upper clamp 5 specifically includes a clamping portion 51 for holding a plate-shaped sample, and a connecting portion 52 for connecting the clamp to a preset position. Of course, the fatigue test in the present embodiment is not limited to the test of the plate-like workpiece, and the shaft-shaped sample or the like can be tested. Therefore, the upper jig 5 and the lower jig 5' are not limited to the plate-like sample jig, and may be A shaft-shaped specimen holder, etc., may be selected according to the type of the workpiece. The material of the upper clamp 5 and the lower clamp 5' can be selected from high-quality carbon tool steel, has good plasticity and strength, can withstand vibration and impact loads, and has moderate hardness and large toughness.

In this embodiment, between the force transmission plate 1 and the connected clamp, a joint bearing is disposed between the work platform 3 and the connected clamp 5, respectively. As shown in Fig. 2, a first joint bearing 6 is disposed between the force transmission plate 1 and the upper clamp 5, and a second joint bearing 6' is disposed between the work platform 3 and the lower clamp 5'.

According to FIG. 1 , those skilled in the art can understand that the two ends of the force transmission plate 1 are actually moving along a circular arc along the hinge connection point, and the distance between the hinge connection point and the end point is a radius, but the workpiece is pulled. The tensile test requires that the workpiece be subjected to a tensile force along the workpiece. Therefore, in this embodiment, a pair of joint bearings are used, one of which is assembled at one end of the force-transmitting plate 1 which is connected to the workpiece to be stretched, that is, the first joint bearing 6 The other is assembled on the working platform 3, that is, the second joint bearing 6'. The structure of the first joint bearing 6 and the second joint bearing 6' is as shown in FIG. 6, and includes a spherical body 61 and a spherical body 61. The threaded post 62, the first joint bearing 6 is connected to the force transmission plate 1 through a spherical groove 12 (as shown in FIGS. 3 and 7) provided on the force transmission plate 1, and the spherical body 61 is disposed in the spherical groove 12. Inside, and can be rotated 360° in the spherical groove 12, the threaded post 62 is screwed into the upper clamp 5 (the upper clamp 5 is provided with a threaded hole), and similarly, the second joint bearing is disposed on the working platform 3. 6' also passes through the spherical body 61 and the spherical concave provided on the working platform (not shown), the threaded post 62 and the lower clamp 5' are screwed. Since the two joint bearings can achieve 360° rotation, although the end of the force transmission plate 1 is in an arc motion during the test, However, it is still possible to ensure that the workpiece to be stretched is subjected to a simple stretching motion.

In this embodiment, as shown in FIG. 1 and FIG. 3, one end of the pressure plate 1 is provided with an arc surface structure 13 at one end of the actuator 4, and the arc structure 13 is provided with an upper convex curved surface. The curved curved surface is in contact with the ram of the actuator 4 for achieving tangential contact between the end of the force-transmitting plate and the actuator ram, that is, the ram of the actuator 4 is pressed against the force At the end of the plate 1, the bottom surface of the indenter of the actuator 4 is tangent to the curved curved surface of the end of the force transmission plate 1 and is in contact with a point of the curved curved surface. The distance between the contact point and the hinge portion of the force transmission plate 1 is stable, so that the stability of the test can be ensured.

Further, the curved surface structure 13 is specifically a semi-cylindrical structure, and the curved curved surface on the curved surface structure 13 is a semi-cylindrical surface of a semi-cylindrical structure, and the top of the semi-cylindrical surface is in contact with the indenter of the actuator 4. The position of the semi-cylindrical structure on the force transmission plate 1 is formed with a notch 13 so that when the ram of the actuator 4 is pressed against the end of the force transmission plate 1, it can make point contact with the top of the cylindrical surface instead of It is in surface contact with the end of the force transmission plate 1.

In this embodiment, as shown in FIG. 4, in order to facilitate the fixing of the test device on the working platform 3, the working platform 3 is provided with a plurality of inverted T-shaped grooves 31, such as the support column 2, the second joint bearing 6', and the like. In the inverted T-shaped groove 31, the test device is fixed by the inverted T-shaped groove 31, which is not only convenient to fix, but also facilitates changing the fixed position.

The fatigue testing device for the pulsation fatigue testing machine provided by the embodiment of the invention provides a force transmission plate by providing a force transmission plate and a support column hingedly connected with the force transmission plate so that the actuator acts on one end of the force transmission plate. The workpiece at the other end is subjected to a tensile test. The device is capable of performing a tensile fatigue test on a small sample and is applied to a pulsation fatigue tester to expand the pulsation fatigue test and the test range.

Another embodiment of the present invention further provides a pulsation fatigue testing machine comprising the pulsation fatigue testing device for a pulsation fatigue testing machine according to any one of the embodiments of the present invention.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

A fatigue testing device for a pulsating fatigue testing machine, comprising: a force transmitting plate and a supporting column fixed on the working platform, wherein a predetermined portion of the force transmitting plate is hingedly connected with the supporting column, and the transmitting force Both ends of the plate can swing up and down around the support column;

One end of the force transmission plate and the working platform are respectively provided with clamps for connecting two ends of the workpiece to be stretched, and the other end of the force transmission plate is provided with an actuator, so that the actuator is When a force is applied to one end of the force transmission plate under the control of the control system, the other end of the force transmission plate stretches the workpiece to be stretched.
The fatigue testing device for a pulsation fatigue testing machine according to claim 1, wherein a predetermined portion of the force transmission plate is provided with a semi-cylindrical projection, and the support column is provided with the semi-cylindrical shape a semi-cylindrical groove with a convex fit;

The semi-cylindrical projections are disposed in the semi-cylindrical recesses, and the semi-cylindrical projections are hingedly coupled to the side walls of the two sides of the semi-cylindrical recesses by pins.
The fatigue testing apparatus for a pulsation fatigue testing machine according to claim 2, wherein a ball is disposed between the semi-cylindrical projection and the semi-cylindrical recess.
The fatigue testing device for a pulsation fatigue testing machine according to claim 1, wherein one end of the force transmitting plate provided with the actuator is provided with a curved surface structure, and the curved surface structure is provided with an upward convex An arcuate curved surface, the top of the curved curved surface being tangent to the indenter of the actuator when the ram of the actuator is pressed against the end of the force transmitting plate.
The fatigue testing device for a pulsation fatigue testing machine according to claim 4, wherein the curved surface structure is a semi-cylindrical structure, and the curved curved surface is a semi-cylindrical surface of the semi-cylindrical structure.
The fatigue test apparatus for a pulsation fatigue tester according to claim 1, wherein a joint bearing is disposed between the force transmission plate and the connected jig, and between the work platform and the connected jig.
The fatigue testing device for a pulsation fatigue testing machine according to claim 1, wherein the working platform is provided with a plurality of inverted T-shaped grooves, and the supporting column and the joint bearing are fixed to the inverted T type. In the slot.
The fatigue testing device for a pulsation fatigue testing machine according to any one of claims 1 to 7, wherein the predetermined portion is an intermediate portion of the force transmission plate, and two of the force transmission plates The distance from the end to the intermediate portion is the same.
A pulsation fatigue testing machine comprising the fatigue testing device for a pulsation fatigue testing machine according to any one of claims 1-8.