Positioning press-in mechanical property testing device and testing method thereof

Abstract

The invention provides a positioning press-in mechanical property testing device and a testing method thereof.The positioning press-in mechanical property testing device comprises a positioning unit, a loading unit and a measuring unit, the loading unit can load a to-be-tested part so that the to-be-tested part can generate stress and strain, and the measuring unit can measure the stress and the strain of the to-be-tested part; the positioning unit can position the loading position and the movement direction of the loading unit, and the measuring unit can detect load and displacement data generated by the to-be-measured component. According to the invention, the residual stress of a press-in point can be measured while press-in is carried out, so that an accurate residual stress test result is ensured, and the reliability of press-in mechanical property calculation is improved; the press-in device is simple, portable and accurate in positioning, the structure that the electric cylinder and the press-in point are not coaxial is adopted, the height of the press-in device is reduced, and the press-in device can be suitable for the space with the limited height.

Description

Technical Field

[0001] The present invention relates to the technical field of measurement of mechanical properties of materials, and particularly relates to a positioning indentation mechanical property testing device and a testing method thereof. Background Art

[0002] Instrumented indentation testing is a method for testing the mechanical properties of materials developed in recent years. In this method, an indenter with a millimeter or micron size is pressed into the surface of the material to be tested, and the load-depth curve during the indentation process is recorded. Based on a mathematical model, important mechanical property parameters such as the stress-strain curve, tensile strength, and fracture toughness of the material are calculated. Compared with traditional mechanical property testing methods, it has the advantages of micro-damage, rapidity, and on-site testability. However, since instrumented indentation is a local testing method, the residual stress in the material has a great influence on the test results.

[0003] At present, there are different calculation methods for indentation mechanical properties considering residual stress, but they all infer the residual stress at the indentation position through a certain algorithm or by comparing specimens. It is impossible to directly measure the residual stress at the indentation position during the indentation test, and the inferred residual stress is difficult to ensure its accuracy, directly reducing the reliability of the mechanical property calculation results. In addition, the current indenters generally adopt a structure with an electric cylinder coaxial with the point to be measured, resulting in a relatively high height and restricting its application in spaces with limited height. Therefore, it is necessary to further reduce the size of the indenter to solve the testing problem in a narrow space.

[0004] Due to the technical problems in the prior art that the calculation method for indentation mechanical properties considering residual stress cannot directly measure the residual stress at the indentation position during the indentation test, resulting in a reduction in the reliability of the mechanical property calculation results, the present invention has studied and designed a positioning indentation mechanical property testing device and a testing method thereof. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the calculation method for indentation mechanical properties considering residual stress in the prior art cannot directly measure the residual stress at the indentation position during the indentation test, resulting in a reduction in the reliability of the mechanical property calculation results, so as to provide a positioning indentation mechanical property testing device and a testing method thereof.

[0006] To solve the above problems, the present invention provides a positioning indentation mechanical property testing device, which includes:

[0007] A positioning unit, a loading unit, and a measuring unit. The loading unit can load the component to be tested to cause stress and strain in the component to be tested. The positioning unit can position the loading position and movement direction of the loading unit, and the measuring unit can detect the load and displacement data generated by the component to be tested.

[0008] In some embodiments,

[0009] The positioning unit includes a bottom cover, a linear bearing, a gland, and a microscope. The component to be measured is disposed in the bottom cover, and a strain gauge is disposed on the component to be measured. The center of the bottom cover is located at the measuring point position of the strain gauge. The microscope is disposed inside the linear bearing and can be adjusted so that the center of the microscope's field of view is located at the center of the measuring point of the strain gauge. Then, the gland is adjusted to tighten the linear bearing.

[0010] In some embodiments,

[0011] The loading unit includes a pressure rod that can be disposed inside the linear bearing to move downward to apply stress to the strain gauge. After the microscope positions the strain gauge and the linear bearing, the microscope is removed from the linear bearing, and then the pressure rod is assembled into the linear bearing.

[0012] In some embodiments,

[0013] The loading unit further includes an electric cylinder, a piston rod, and a pressing plate. The electric cylinder is connected to the piston rod to drive the piston rod to move up and down in the vertical direction. The pressing plate is connected to the upper end or above the piston rod, and the pressing plate is driven by the piston rod to move up and down in the vertical direction. At least a part of the structure of the pressing plate is connected to the upper end of the pressure rod to drive the pressure rod to move up and down in the vertical direction through the up and down movement of the pressing plate, so as to apply a vertical pressure to the strain gauge through the above-mentioned pressure rod.

[0014] In some embodiments,

[0015] The loading unit further includes a frame, a frame bottom plate, and a guiding mechanism. The lower end of the frame is disposed on the frame bottom plate, and the lower end of the bottom cover is also disposed on the frame bottom plate. The bottom cover and the frame are spaced apart in the horizontal direction. The guiding mechanism is disposed between the pressing plate and the piston rod;

[0016] The upper end of the frame is a flat plate structure. Below the flat plate structure is a vertical rod. The upper end of the vertical rod is connected to the flat plate structure, and the lower end of the vertical rod is connected to the upper end of the frame bottom plate. There are multiple vertical rods, and the multiple vertical rods are spaced apart to enclose a hollow space inside. The electric cylinder is disposed in the hollow space, or the electric cylinder is disposed on the upper end of the flat plate structure.

[0017] In some embodiments,

[0018] The measuring unit includes a load sensor and a displacement sensor. The load sensor is disposed at the upper end of the pressure bar and can contact the pressure plate to bear and detect the load of the pressure plate pressing down the pressure bar. The displacement sensor is disposed on the frame. A gasket projects outward from the pressure bar. One end of the displacement sensor is connected to the frame and the other end projects toward the gasket, and is spaced from the gasket by a preset distance greater than or equal to 0 in the vertical direction, so as to obtain the movement displacement of the pressure bar by detecting the distance between the displacement sensor and the gasket.

[0019] In some embodiments,

[0020] The gland is sleeved on the outer periphery of the linear bearing, and an external thread is provided on the outer periphery of the gland. The bottom cover has a hollow inner cavity, and an internal thread is provided on the inner peripheral wall of the hollow inner cavity of the bottom cover. The gland can be inserted into the hollow inner cavity of the bottom cover, and a threaded connection is formed between the external thread of the gland and the internal thread of the bottom cover, so that the bottom surface of the gland and the top surface of the bottom cover are respectively in close contact with the flange top surface and the bottom surface of the linear bearing by tightening the thread, thereby fixing the linear bearing; an external thread is also provided on the outer periphery of the bottom cover, and the external thread of the bottom cover can be in threaded fit connection with the frame bottom plate.

[0021] In some embodiments,

[0022] Screws are further provided on the outer periphery of the bottom cover. The screws extend from the outer periphery of the bottom cover to the inner periphery of the bottom cover. There are multiple screws, and the multiple screws are circumferentially spaced on the outer periphery of the bottom cover. By adjusting the lengths of the multiple screws extending into the inner periphery of the bottom cover, the visual field center of the microscope can be adjusted to coincide with the measuring point center of the strain gauge.

[0023] In some embodiments,

[0024] After the residual stress is detected by the indentation strain method using the strain gauge, a pneumatic turbine drill is installed at the bottom of the pressure bar, and an anti-rotation block and a groove anti-rotation pressure plate are installed at the upper end of the pressure bar. The groove anti-rotation pressure plate has a groove. By rotating the anti-rotation block so that it is stuck into the groove, a drilling strain method test of the residual stress at the pressing end is carried out and compared with the test result of the indentation strain method.

[0025] The present invention also provides a test method for the positioning press-in mechanical property test device as described above, which includes:

[0026] S1. A strain gauge is arranged at the position to be measured of the component to be measured;

[0027] S2. Place the component to be measured and the strain gauge in the bottom cover, and adjust to make the center of the bottom cover coincide with the measuring point position of the strain gauge;

[0028] S3. Place the linear bearing in the bottom cover, put the microscope into the linear bearing, adjust the microscope to focus on the plane to be measured, and adjust multiple screws to make the center of the microscope's field of view coincide with the center of the measuring point of the strain gauge, and tighten the gland;

[0029] S4. Take out the microscope and install the pressure bar into the linear bearing, make the indenter at the lower end of the pressure bar contact the component to be measured, rotate the pressure bar to make the gasket on it contact the displacement sensor, zero the load sensor, displacement sensor and resistance strain gauge, and adjust the position of the pressure plate so that it can cover the upper surface of the pressure bar when pressing down;

[0030] S5. Start the electric cylinder to drive the pressure plate to load on the pressure bar, and record the load, displacement and strain during the loading process through the load sensor, displacement sensor and resistance strain gauge respectively;

[0031] S6. Calculate the residual stress by the indentation strain method according to the strain value obtained by the resistance strain gauge, correct the load-displacement data according to the obtained residual stress, and calculate the mechanical properties of the material according to the load and displacement data;

[0032] S7. After calculating the residual stress, remove the loading unit, insert the microscope into the linear bearing again, and measure the size of the indentation after pressing;

[0033] S8. After calculating the residual stress, remove the loading unit, install the pneumatic turbine drill at the bottom of the pressure bar, remove the load sensor at the upper part of the pressure bar, install the anti-rotation block, replace the pressure plate with the grooved anti-rotation pressure plate, move the loading unit back to the original position, rotate the pressure bar to make the anti-rotation block enter the groove of the grooved anti-rotation pressure plate, and conduct a test on the residual stress by the drilling strain method at the pressing point, and compare with the test result of the indentation strain method.

[0034] A positioning press-in mechanical property testing device and its testing method provided by the present invention have the following beneficial effects:

[0035] 1. By providing a positioning unit and a loading unit, the present invention can load the component to be tested through the loading unit, perform a press-in test on the component to be tested, accurately position the press-in direction and press-in position through the positioning unit, precisely implement the test function, and detect the load and displacement data generated by the component to be tested through the measuring unit. Thus, while pressing in, the residual stress at the press-in point can also be measured, ensuring accurate residual stress test results and improving the reliability of the calculation of the press-in mechanical properties.

[0036] 2. The present invention also adopts the structure of an electric cylinder, a piston rod, and a pressing plate. The pressing plate is connected above the piston rod, and the piston rod moves up and down in the vertical direction. At least part of the structure of the pressing plate is connected to the upper end of the pressure rod, so that the up and down movement of the pressing plate can drive the pressure rod to move up and down in the vertical direction, enabling the load to be directly applied directly above the pressure rod, so that the pressure rod does not bear lateral loads and bending loads, ensuring the vertical press-in of the indenter, precisely conducting the press-in experiment at the center of the strain gauge, and realizing multiple test functions.

[0037] 3. The present invention also sets the bottom cover and the frame at a horizontal interval, making the press-in points of the electric cylinder and the pressure rod form a non-coaxial structure, thereby effectively reducing the height of the press-in device and enabling the test device to be applicable to spaces with limited height. And the present invention further places the electric cylinder in the hollow space surrounded by the vertical rods of the frame, which can further reduce the overall height of the test device. When the electric cylinder is arranged at the upper end of the flat plate structure of the frame, the electric cylinder can provide a higher and greater loading force for the pressure rod. Description of the Drawings

[0038] Figure 1 is the overall structure diagram of the positioning press-in mechanical property test device of the present invention;

[0039] Figure 2 is Figure 1 the exploded structure diagram of the positioning unit in

[0040] Figure 3 is Figure 1 the structure diagram of the microscope in

[0041] Figure 4 is Figure 1 the structure diagram of the pressure rod in

[0042] Figure 5 is Figure 1 the longitudinal sectional view of the pressure rod in

[0043] Figure 6 is Figure 1 the schematic diagram of the dovetail groove guide connection between the frame and the frame bottom plate in

[0044] Figure 7 is Figure 1Schematic diagram of bolt connection between the frame and the frame bottom plate;

[0045] Figure 8 is Figure 1 Top view of the test device in after installing strain gauges;

[0046] Figure 9 is Figure 1 Structural diagram of the pressure bar in after installing the anti-rotation block and the pneumatic turbine drill;

[0047] Figure 10 is the Figure 9 Structural diagram of the groove anti-rotation pressure plate that cooperates with the anti-rotation block in ;

[0048] Figure 11 is the structural diagram of the initial state of the test device in Embodiment 2 of the present invention (the frame and the frame bottom plate are connected by a dovetail groove guide rail);

[0049] Figure 12 is the structural diagram of the loading state of the test device in Embodiment 2 of the present invention (the frame and the frame bottom plate are connected by a dovetail groove guide rail);

[0050] Figure 13 is the structural diagram of the initial state of the test device in Embodiment 3 of the present invention (the frame and the frame bottom plate are connected by bolts);

[0051] Figure 14 is the structural diagram of the loading state of the test device in Embodiment 3 of the present invention (the frame and the frame bottom plate are connected by bolts).

[0052] The reference numerals are shown as:

[0053] 1. Bottom cover; 2. Linear bearing; 3. gland; 4. Pressure bar; 5. Electric cylinder; 6. Frame; 7. Frame bottom plate; 8. Pressure plate; 9. Load sensor; 10. Displacement sensor; 11. Piston rod; 12. Gasket; 13. Screw; 14. Microscope; 15. Limit ring; 16. Oblique tip surface; 17. Strain gauge; 18. Anti-rotation block; 19. Clamping handle; 20. Pneumatic turbine drill; 21. Groove anti-rotation pressure plate; 210. Groove; 22. Guide mechanism. Detailed implementation manners

[0054] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way restrictive of the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0055] It should be noted that the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0056] Unless otherwise specifically stated, the relative arrangements of the components and steps, numerical expressions, and values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed herein, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters indicate like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0057] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the protection scope of the present invention; the orientation words "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0058] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper", etc. can be used here to describe the spatial positional relationship of a device or feature shown in the figure with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figure for the device. For example, if the device in the drawing is inverted, the device described as "above" or "over" other devices or structures will then be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations of the spatial relative descriptions used here are made.

[0059] In addition, it should be noted that the use of terms such as "first", "second", etc. to define components is only for the convenience of distinguishing the corresponding components. Without further statement, the above terms have no special meaning, and thus cannot be construed as a limitation on the protection scope of the present invention.

[0060] As Figure 1-14 shown, the present invention provides a positioning and press-in mechanical property testing device, which includes:

[0061] a positioning unit, a loading unit, and a measuring unit. The loading unit can load a component to be tested to cause stress and strain in the component to be tested. The positioning unit can position the loading position and movement direction of the loading unit, and the measuring unit can detect the load and displacement data generated by the component to be tested.

[0062] By providing a positioning unit and a loading unit, the present invention can load the component to be tested through the loading unit, can perform a press-in test on the component to be tested. Through the positioning unit, the press-in direction and press-in position can be accurately positioned, and the test function can be precisely realized. Through the measuring unit, the load and displacement data generated by the component to be tested can be detected, so that the residual stress at the press-in point can be measured while pressing in, ensuring accurate residual stress test results and improving the reliability of the calculation of press-in mechanical properties.

[0063] The device of the present invention adopts a gland-type positioning mechanism and a non-rigidly connected loading mechanism, which is simple, portable, and accurately positioned. The load is applied directly above the pressure bar, and the pressure bar does not bear lateral and bending loads, ensuring that the indenter presses vertically. It can accurately perform an indentation experiment at the center of the strain gauge, measure the residual stress at the indentation point while indenting, ensure accurate residual stress test results, and improve the reliability of the calculation of indentation mechanical properties. The structure with the electric cylinder non-coaxial with the indentation point reduces the height of the indentation device, enabling the device to be applicable to spaces with limited height.

[0064] In some embodiments,

[0065] The positioning unit includes a bottom cover 1, a linear bearing 2 (flanged linear bearing), a gland 3, and a microscope 14. The component to be measured is arranged in the bottom cover 1, a strain gauge 17 is arranged on the component to be measured, the center of the bottom cover 1 is located at the measuring point position of the strain gauge 17, the microscope 14 is arranged inside the linear bearing 2, and the field of view center of the microscope can be adjusted to be located at the measuring point center of the strain gauge 17, and then the gland 3 is adjusted to tighten the linear bearing 2.

[0066] This is the preferred structural form of the positioning unit of the present invention. The linear bearing can accommodate the microscope, and the microscope can detect the position of the strain gauge and effectively position the linear bearing, ensuring that the field of view center of the microscope is located at the measuring point center of the strain gauge. The linear bearing is tightened by the gland, so that the relative position between the linear bearing and the bottom cover is fixed, facilitating the subsequent effective and accurate positioning effect of the pressure bar pressing the strain gauge.

[0067] In some embodiments,

[0068] The loading unit includes a pressure bar 4, and the pressure bar 4 can be arranged inside the linear bearing 2 to move downward to apply stress to the strain gauge 17. After the microscope 14 positions the strain gauge 17 and the linear bearing 2, the microscope 14 is removed from the linear bearing 2, and then the pressure bar 4 is assembled into the linear bearing 2.

[0069] The loading unit of the present invention preferably further includes a pressure bar, which can apply stress to the strain gauge by pressing down the pressure bar to cause deformation, measure the residual stress at the indentation point while realizing the indentation test, improve the test results of the residual stress, and improve the reliability of the calculation of indentation mechanical properties.

[0070] In some embodiments,

[0071] The loading unit further includes an electric cylinder 5, a piston rod 11, and a pressing plate 8. The electric cylinder 5 is connected to the piston rod 11 to drive the piston rod 11 to move up and down in the vertical direction. The pressing plate 8 is connected to the upper end or above the piston rod 11. The pressing plate 8 is driven by the piston rod 11 to move up and down in the vertical direction. At least part of the structure of the pressing plate 8 is connected to the upper end of the pressure rod 4, so as to drive the pressure rod 4 to move up and down in the vertical direction through the up and down movement of the pressing plate 8, and apply a vertical pressure to the strain gauge 17 through the above-mentioned pressure rod 4.

[0072] The loading unit of the present invention preferably includes an electric cylinder, a piston rod, and a pressing plate. The pressing plate is connected above the piston rod. The piston rod moves up and down in the vertical direction. At least part of the structure of the pressing plate is connected to the upper end of the pressure rod, so as to drive the pressure rod to move up and down in the vertical direction through the up and down movement of the pressing plate, so that the load is directly applied directly above the pressure rod, so that the pressure rod does not bear lateral load and bending load, ensuring the vertical pressing of the indenter, accurately performing the indentation experiment at the center of the strain gauge, and realizing various test functions.

[0073] In some embodiments,

[0074] The loading unit further includes a frame 6, a frame bottom plate 7, and a guiding mechanism 22. The lower end of the frame 6 is arranged on the frame bottom plate 7, and the lower end of the bottom cover 1 is also arranged on the frame bottom plate 7. The bottom cover 1 and the frame 6 are arranged at intervals in the horizontal direction. The guiding mechanism 22 is arranged between the pressing plate 8 and the piston rod 11;

[0075] The upper end of the frame 6 is a flat plate structure. Below the flat plate structure is a vertical rod. The upper end of the vertical rod is connected to the flat plate structure, and the lower end of the vertical rod is connected to the upper end of the frame bottom plate 7. There are multiple vertical rods, and the multiple vertical rods are arranged at intervals to enclose a hollow space inside. The electric cylinder 5 is arranged in the hollow space, or the electric cylinder 5 is arranged on the upper end of the flat plate structure.

[0076] The loading unit of the present invention preferably further includes a frame, a frame bottom plate, and a guiding mechanism. The bottom cover and the frame are arranged at intervals in the horizontal direction, so that the indenting points of the electric cylinder and the pressure rod form a non-coaxial structure, effectively reducing the height of the indenting device, so that the testing device can be applicable to a space with limited height; the present invention further reduces the overall height of the testing device by arranging the electric cylinder in the hollow space enclosed by the vertical rods of the frame. When the electric cylinder is arranged on the upper end of the flat plate structure of the frame, the electric cylinder can provide a higher and greater loading force to the pressure rod.

[0077] In some embodiments,

[0078] The measurement unit includes a load sensor 9 and a displacement sensor 10. The load sensor 9 is disposed at the upper end of the pressure bar 4 and can contact the pressure plate 8 to bear and detect the load of the pressure plate 8 pressing down on the pressure bar 4. The displacement sensor 10 is disposed on the frame 6. A gasket 12 extends outward from the pressure bar 4. One end of the displacement sensor 10 is connected to the frame 6 and the other end extends toward the gasket 12 and is spaced from the gasket 12 by a preset distance greater than or equal to 0 in the vertical direction, so as to detect the distance between the displacement sensor 10 and the gasket 12 to obtain the movement displacement of the pressure bar 4.

[0079] The measurement unit of the present invention preferably includes a load sensor and a displacement sensor, which can detect the load of the pressure plate when the pressure bar is pressed down through the load sensor, and the displacement sensor can accurately detect the displacement of the up and down movement of the pressure bar by the relative displacement with the gasket on the pressure bar, so as to calculate the strain generated by the strain gauge and achieve precise detection for the press-in test of the component to be measured.

[0080] In some embodiments,

[0081] The gland 3 is sleeved on the outer periphery of the linear bearing 2, and an external thread is provided on the outer periphery of the gland 3. The bottom cover 1 has a hollow inner cavity, and an internal thread is provided on the inner peripheral wall of the hollow inner cavity of the bottom cover 1. The gland 3 can be inserted into the hollow inner cavity of the bottom cover 1 and form a threaded connection through the external thread of the gland 3 and the internal thread of the bottom cover 1, so that the bottom surface of the gland 3 and the top surface of the bottom cover 1 are respectively in close contact with the flange top surface and the bottom surface of the linear bearing 2 by tightening the thread, thereby fixing the linear bearing 2; an external thread is also provided on the outer periphery of the bottom cover 1, and the external thread of the bottom cover 1 can be in threaded fit connection with the frame bottom plate 7.

[0082] In the present invention, by sleeving the gland on the outer periphery of the linear bearing and fixedly connecting it with the linear bearing, and providing an external thread on the outer periphery of the gland, it can form a threaded fit with the internal thread of the bottom cover and form an effective fixation with the bottom cover, so as to fix the linear bearing, and the outer periphery of the bottom cover can be fixed to the frame bottom plate by providing an external thread.

[0083] In some embodiments,

[0084] Screws 13 (hand-tightening screws) are further provided on the outer periphery of the bottom cover 1. The screws 13 extend from the outer periphery of the bottom cover 1 to the inner periphery of the bottom cover 1. There are multiple screws 13, and the multiple screws 13 are circumferentially spaced on the outer periphery of the bottom cover 1. By adjusting the lengths of the multiple screws 13 extending into the inner periphery of the bottom cover 1, the center of the field of view of the microscope 14 can be adjusted to coincide with the center of the measurement point of the strain gauge 17.

[0085] Through the screw structure provided on the outer periphery of the bottom cover, the present invention can adjust the length extending into the inner periphery of the bottom cover through multiple circumferentially spaced screws, thereby adjusting the horizontal direction (including front, rear, left, and right) of the microscope, so as to adjust the visual field center of the microscope to coincide with the measuring point center of the strain gauge, ensuring the precise positioning of the insertion position of the pressure bar.

[0086] In some embodiments,

[0087] After detecting the residual stress by the indentation strain method using the strain gauge 17, an air turbine drill 20 is installed at the bottom of the pressure bar 4, and an anti-rotation block 18 and a groove anti-rotation pressing plate 21 are installed at the upper end of the pressure bar 4. The groove anti-rotation pressing plate 21 has a groove 210. By rotating the anti-rotation block 18 to make it snap into the groove 210, the drilling strain method test of the residual stress at the pressing end is carried out and compared with the test result of the indentation strain method.

[0088] Through the provision of the air turbine drill, the anti-rotation block, and the groove anti-rotation pressing plate, the present invention can carry out the drilling strain method test on the residual stress at the pressing end of the pressure bar, so as to supplement the test result detected by the indentation strain method and compare it with the test result of the indentation strain method, thereby further improving the accuracy of the test result.

[0089] As Figure 1 shown, the present invention provides a portable precise positioning press-in mechanical property testing device, including a precise positioning unit, a loading unit, and a measuring unit.

[0090] The precise positioning unit includes a bottom cover 1, a flanged linear bearing 2, a gland 3, and a microscope 14.

[0091] The loading unit includes an electric cylinder 5, a frame 6, a frame bottom plate 7, a pressing plate 8, a pressure bar 4, and a limit ring 15.

[0092] The measuring unit includes a load sensor 9 and a displacement sensor 10.

[0093] As Figure 2 shown, the bottom cover 1 and the gland 3 are circular rings. The outer surface of the bottom cover 1 has threads and is fixed on the frame bottom plate 7 through the threads. The inner surface of the bottom cover 1 has threads, the outer surface of the gland 3 has threads, the bottom cover 1 and the gland 3 are connected by threads, and the bottom cover 1 has a hollow flange structure inside. The side surface of the bottom cover 1 has a threaded hole, and a screw 13 is installed in the threaded hole.

[0094] The outer diameter of the flange of the flanged linear bearing 2 is larger than the inner diameter of the hollow flange inside the bottom cover 1 and smaller than the inner diameter of the bottom cover 1. The inner diameter of the gland 3 is the same as the inner diameter of the hollow flange of the bottom cover 1. The outer diameters of the microscope 14 and the pressure rod 4 are the same as the inner diameter of the flanged linear bearing 2.

[0095] The electric cylinder 5 is installed on the frame 6. The electric cylinder 5 can be installed below the frame 6 or above the frame 6. As Figure 1 shown, when the electric cylinder 5 is installed below the frame 6, the overall height of the device can be reduced. As Figure 12 shown, when the electric cylinder 5 is installed above the frame 6, the electric cylinder 5 can provide a higher loading force. A guiding mechanism 22 is installed on the electric cylinder.

[0096] The pressure plate 8 is installed on the piston rod 11 of the electric cylinder. As Figure 10 shown, the pressure plate 8 can have an anti-rotation groove. As Figure 6 and Figure 7 shown, the connection mode between the frame 6 and the frame bottom plate 7 can be bolt connection or dovetail groove guide connection.

[0097] As Figure 5 shown, the lower part of the pressure rod 4 is machined with an inclined pin surface 16 and threads for installing a collet and a locking nut. A pressure head or a pneumatic turbine drill 20 can be installed on the collet. The pneumatic turbine drill 20 has a clamping handle 19. The upper end of the pressure rod 4 has a threaded hole for installing a load sensor 9 or an anti-rotation block 18. The width of the anti-rotation block 18 is the same as the diameter of the pressure rod 4, and the length of the anti-rotation block 18 is greater than the width of the anti-rotation groove on the pressure rod 4. A gasket 12 is installed in the middle of the pressure rod 4.

[0098] As Figure 4 shown, the load sensor 9 is installed at the upper end of the pressure rod 4, and the limit ring 15 is installed at the lower part of the pressure rod 4. The displacement sensor 10 is installed on the frame 6.

[0099] The present invention also provides a test method for the positioning and pressing mechanical property test device as described above, which includes:

[0100] S1. A strain gauge 17 is arranged at the position to be measured of the component to be measured;

[0101] S2. The component to be measured and the strain gauge 17 are arranged in the bottom cover 1, and adjusted so that the center of the bottom cover 1 coincides with the measuring point position of the strain gauge 17;

[0102] S3. Place the linear bearing 2 in the bottom cover 1, put the microscope 14 into the linear bearing 2, adjust the microscope to focus on the plane to be measured, and adjust a plurality of screws 13 so that the center of the field of view of the microscope 14 coincides with the center of the measuring point of the strain gauge 17, and tighten the gland 3;

[0103] S4. Take out the microscope 14 and install the pressure bar 4 into the linear bearing 2 so that the pressure head at the lower end of the pressure bar 4 contacts the component to be measured. Rotate the pressure bar 4 so that the gasket 12 thereon contacts the displacement sensor 10. Zero the load sensor 9, displacement sensor 10 and resistance strain gauge, and adjust the position of the pressure plate 8 so that it can cover the upper surface of the pressure bar 4 when pressing down;

[0104] S5. Start the electric cylinder 5 to drive the pressure plate 8 to load on the pressure bar 4, and record the load, displacement and strain during the loading process through the load sensor 9, displacement sensor 10 and resistance strain gauge respectively;

[0105] S6. Calculate the residual stress by the indentation strain method according to the strain value obtained by the resistance strain gauge, correct the load-displacement data according to the obtained residual stress, and calculate the mechanical properties of the material according to the load and displacement data;

[0106] S7. After calculating the residual stress, remove the loading unit, re-insert the microscope 14 into the linear bearing 2, and measure the size of the indentation after pressing;

[0107] S8. After calculating the residual stress, remove the loading unit, install the pneumatic turbine drill 20 at the bottom of the pressure bar 4, remove the load sensor 9 on the upper part of the pressure bar 4, and install the anti-rotation block 18. Replace the pressure plate 8 with the groove anti-rotation pressure plate 21, move the loading unit back to its original position, rotate the pressure bar 4 so that the anti-rotation block 18 enters the groove of the groove anti-rotation pressure plate 21, and perform a drilling strain method test on the residual stress at the press-in point, and compare it with the test result of the indentation strain method.

[0108] The present invention provides a method for using a portable precise positioning press-in mechanical property testing device, including the following steps:

[0109] Example 1

[0110] (1) As Figure 8 shown, paste the strain gauge 17 at the position to be measured on the surface of the component.

[0111] (2) Fix the testing device of the present invention on the component, adjust the position of the device so that the center of the bottom cover 1 is approximately located at the measuring point position of the strain gauge 17, and adjust the height of the feet of the device so that the axis of the bottom cover 1 is perpendicular to the position to be measured.

[0112] (3) Place the flanged linear bearing 2 in the bottom cover 1, put the microscope 14 into the flanged linear bearing 2, adjust the microscope 14 so that it focuses on the plane to be measured (the function of the microscope is to accurately position the pressure bar to the desired pressing position), and make the center of the field of view of the microscope 14 located at the center of the measuring point of the strain gauge 17 by adjusting the 4 screws 13, then tighten the gland 3. Use a blade to cut off around the center of the measuring point of the strain gauge and remove the center of the measuring point of the strain gauge.

[0113] (4) Take out the microscope 14 from the flanged linear bearing 2, put the pressure bar 4 into the flanged linear bearing 2, and make the indenter contact the surface to be measured. Rotate the pressure bar 4 so that the gasket 12 on the pressure bar 4 contacts the displacement sensor 10, as Figure 1 shown. Zero the load sensor 9, zero the resistance strain gauge, and adjust the position of the pressure plate 8 so that it can cover the upper surface of the pressure bar 4 when pressing down.

[0114] (5) Start the electric cylinder 5 to drive the pressure plate 8 to load on the pressure bar 4, and record the load, displacement and strain during the loading process through the load sensor 9, displacement sensor 10 and resistance strain gauge. Stop loading when the preset load or displacement is reached.

[0115] (6) Calculate the residual stress by using the indentation strain method according to the strain obtained from the resistance strain gauge, correct the load-displacement data according to the obtained residual stress, and calculate the mechanical properties of the material according to the load and displacement data (the detection of the residual stress is calculated through the strain obtained by the resistance strain gauge and the resistance strain instrument. The function of the pressure bar + electric cylinder is to create an indentation, and the load sensor and displacement sensor are used to obtain the load and displacement data during the pressing process of the pressure bar, and the mechanical properties during pressing are calculated through the load and displacement data).

[0116] (7) If necessary, after step (6), the loading unit can be moved away, and the microscope 14 can be inserted back onto the flanged linear bearing 2 to measure the size of the indentation after pressing.

[0117] (8) If necessary, after step (6), the loading unit can be moved away, install the pneumatic turbine drill 20 at the bottom of the pressure bar 4, remove the load sensor 9 on the upper part of the pressure bar 4, install the anti-rotation block 18, replace the pressure plate 8 with the groove anti-rotation pressure plate 21 as Figure 10 shown, move the loading unit back to its original position, rotate the pressure bar 4 so that the anti-rotation block 18 can enter the groove of the groove anti-rotation pressure plate 21, and conduct a drilling strain method test on the residual stress at the pressing point, and compare the test results with those of the indentation strain method.

[0118] Example 2

[0119] As Figure 11As shown in the figure, the difference between this embodiment and the device of Embodiment 1 is that the electric cylinder 5 is installed on the frame 6, and the connection mode between the frame 6 and the frame bottom plate 7 is dovetail groove guide connection.

[0120] The difference between this embodiment and the method of Embodiment 1 is that step (4) is as follows:

[0121] (4) Take out the microscope 14 from the flanged linear bearing 2, put the pressure bar 4 into the flanged linear bearing 2, and make the indenter contact the surface to be measured. Move the frame 6 on the dovetail groove guide to make the piston rod 11 of the electric cylinder 5 be as directly above the pressure bar 4 as possible, and lock the screw on the side of the dovetail groove guide. Rotate the pressure bar 4 to make the gasket 12 on the pressure bar 4 contact the displacement sensor 10. Zero the load sensor 9, zero the resistance strain gauge, and adjust the position of the pressure plate 8 so that it can cover the upper surface of the pressure bar 4 when pressing down.

[0122] Embodiment 3

[0123] As Figure 12 shown, the difference between this embodiment and the device of Embodiment 1 is that the electric cylinder 5 is installed on the frame 6, the connection mode between the frame 6 and the frame bottom plate 7 is bolt connection, and the mounting holes on the frame bottom plate 7 are elongated holes for adjusting the mounting position of the frame 6.

[0124] The difference between this embodiment and the method of Embodiment 1 is that, as Figure 13 shown, the frame 6 is not installed during the test, and the frame 6 is installed until step (4). Step (4) of this embodiment is as follows:

[0125] (4) Take out the microscope 14 from the flanged linear bearing 2, put the pressure bar 4 into the flanged linear bearing 2, and make the indenter contact the surface to be measured. Install the frame 6 on the frame bottom plate 7, and adjust the position of the frame 6, as Figure 14 shown, to make the piston rod 11 of the electric cylinder 5 be as directly above the pressure bar 4 as possible, and tighten the screws connecting the frame 6 and the frame bottom plate 7. Rotate the pressure bar 4 to make the gasket 12 on the pressure bar 4 contact the displacement sensor 10. Zero the load sensor 9, zero the resistance strain gauge, and adjust the position of the pressure plate 8 so that it can press on the load sensor 9 driven by the electric cylinder 5.

[0126] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. The above is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can still be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A positioning press-in mechanical properties testing device, characterized in that: include: A positioning unit, a loading unit and a measuring unit, wherein the loading unit can load the component to be tested so that the component to be tested generates stress and strain, the positioning unit can locate the loading position and movement direction of the loading unit, and the measuring unit can detect the load and displacement data generated by the component to be tested.

2. The positioning and pressing mechanical properties testing device according to claim 1, characterized in that: The positioning unit comprises a bottom cover (1), a linear bearing (2), a pressure cover (3) and a microscope (14); the component to be measured is arranged in the bottom cover (1); a strain gauge (17) is arranged on the component to be measured; the center of the bottom cover (1) is located at the measuring point position of the strain gauge (17); the microscope (14) is arranged inside the linear bearing (2); the center of the field of view of the microscope can be adjusted so that the center is located at the measuring point center of the strain gauge (17); and the pressure cover (3) is adjusted so that the linear bearing (2) is tightened.

3. The positioning and pressing mechanical property testing device according to claim 2, characterized in that: The loading unit comprises a pressure rod (4), which can be arranged inside the linear bearing (2) so as to be able to move downward to apply stress to the strain gauge (17). After the microscope (14) has positioned the strain gauge (17) and the linear bearing (2), the microscope (14) is removed from the linear bearing (2), and then the pressure rod (4) is assembled into the linear bearing (2).

4. The positioning and pressing mechanical property testing device according to claim 3 is characterized in that: The loading unit further comprises an electric cylinder (5), a piston rod (11) and a pressure plate (8); the electric cylinder (5) is connected to the piston rod (11) so as to drive the piston rod (11) to move up and down in a vertical direction; the pressure plate (8) is connected to the upper end or above the piston rod (11); the pressure plate (8) is driven by the piston rod (11) to move up and down in a vertical direction; at least part of the structure of the pressure plate (8) is connected to the upper end of the pressure rod (4) so ​​as to drive the pressure rod (4) to move up and down in a vertical direction through the up and down movement of the pressure plate (8), so as to apply pressure in a vertical direction to the strain gauge (17) through the pressure rod (4).

5. The positioning and pressing mechanical property testing device according to claim 4, characterized in that: The loading unit further comprises a frame (6), a frame bottom plate (7) and a guide mechanism (22); the lower end of the frame (6) is arranged on the frame bottom plate (7), the lower end of the bottom cover (1) is also arranged on the frame bottom plate (7), the bottom cover (1) and the frame (6) are arranged at intervals in the horizontal direction, and the guide mechanism (22) is arranged between the pressure plate (8) and the piston rod (11); The upper end of the frame (6) is a flat plate structure, and below the flat plate structure is a vertical rod. The upper end of the vertical rod is connected to the flat plate structure, and the lower end of the vertical rod is connected to the upper end of the frame bottom plate (7). There are multiple vertical rods, and the multiple vertical rods are arranged at intervals to form a hollow space inside. The electric cylinder (5) is arranged in the hollow space, or the electric cylinder (5) is arranged at the upper end of the flat plate structure.

6. The positioning and pressing mechanical property testing device according to claim 5, characterized in that: The measuring unit comprises a load sensor (9) and a displacement sensor (10). The load sensor (9) is arranged at the upper end of the pressure rod (4) and can contact the pressure plate (8) so as to bear and detect the load of the pressure plate (8) pressing the pressure rod (4) downward. The displacement sensor (10) is arranged on the frame (6). A gasket (12) extends outward from the pressure rod (4). One end of the displacement sensor (10) is connected to the frame (6) and the other end extends in the direction of the gasket (12). The displacement sensor (10) is spaced apart from the gasket (12) at a preset distance greater than or equal to 0 in the vertical direction, so as to obtain the movement displacement of the pressure rod (4) by detecting the distance between the displacement sensor (10) and the gasket (12).

7. The positioning press-in mechanical properties testing device according to any one of claims 5-6, characterized in that: The pressure cover (3) is sleeved on the outer circumference of the linear bearing (2), and the outer circumference of the pressure cover (3) is provided with an external thread. The bottom cover (1) has a hollow inner cavity, and the inner circumferential wall of the hollow inner cavity of the bottom cover (1) has an internal thread. The pressure cover (3) can be inserted into the hollow inner cavity of the bottom cover (1), and a threaded connection is formed with the internal thread of the bottom cover (1) through the external thread of the pressure cover (3), so that the bottom surface of the pressure cover (3) and the top surface of the bottom cover (1) are respectively in close contact with the flange top surface and the bottom surface of the linear bearing (2) by tightening the thread, thereby fixing the linear bearing (2); the outer circumference of the bottom cover (1) is also provided with an external thread, and the external thread of the bottom cover (1) can be threadedly matched with the frame bottom plate (7).

8. The positioning and pressing mechanical property testing device according to any one of claims 4 to 7, characterized in that: The outer periphery of the bottom cover (1) is also provided with screws (13), and the screws (13) extend from the outer periphery of the bottom cover (1) to the inner periphery of the bottom cover (1). There are a plurality of screws (13), and the plurality of screws (13) are arranged at intervals along the circumferential direction on the outer periphery of the bottom cover (1). By adjusting the length of the plurality of screws (13) extending into the inner periphery of the bottom cover (1), the center of the field of view of the microscope (14) can be adjusted to coincide with the center of the measuring point of the strain gauge (17).

9. The positioning and pressing mechanical property testing device according to claim 8, characterized in that: After the residual stress is detected by the indentation strain method using a strain gauge (17), a pneumatic turbine drill (20) is installed at the bottom of the pressure rod (4), and an anti-rotation block (18) and a groove anti-rotation pressure plate (21) are installed at the upper end of the pressure rod (4). The groove anti-rotation pressure plate (21) has a groove (210). The anti-rotation block (18) is rotated to be inserted into the groove (210), and the residual stress of the pressed end is tested by the drilling strain method, and the test results are compared with those of the indentation strain method.

10. A testing method for the positioning and pressing mechanical property testing device according to claim 9, characterized in that: include: S1, arranging a strain gauge (17) at a position to be measured of the component to be measured; S2, placing the component to be measured and the strain gauge (17) in the bottom cover (1), and adjusting so that the center of the bottom cover (1) coincides with the measuring point position of the strain gauge (17); S3, placing the linear bearing (2) in the bottom cover (1), placing the microscope (14) in the linear bearing (2), adjusting the microscope so that it focuses on the plane to be measured, adjusting a plurality of screws (13) so that the center of the field of view of the microscope (14) coincides with the center of the measuring point of the strain gauge (17), and tightening the pressure cover (3); S4, taking out the microscope (14) and installing the pressure rod (4) into the linear bearing (2), so that the pressure head at the lower end of the pressure rod (4) contacts the component to be tested, rotating the pressure rod (4) so ​​that the gasket (12) thereon contacts the displacement sensor (10), clearing the load sensor (9), the displacement sensor (10) and the resistance strain gauge, and adjusting the position of the pressure plate (8) so that it can cover the upper surface of the pressure rod (4) when pressed down; S5, starting the electric cylinder (5), driving the pressure plate (8) to load the pressure rod (4), and recording the load, displacement and strain during the loading process through the load sensor (9), the displacement sensor (10) and the resistance strain gauge; S6. Calculate the residual stress by using the indentation strain method according to the strain value obtained by the resistance strain gauge, correct the load displacement data according to the obtained residual stress, and calculate the mechanical properties of the material according to the load and displacement data; S7, after calculating the residual stress, remove the loading unit, reinsert the microscope (14) into the linear bearing (2), and measure the size of the indentation after insertion; S8. After calculating the residual stress, remove the loading unit, install the pneumatic turbine drill (20) at the bottom of the pressure rod (4), remove the load sensor (9) on the upper part of the pressure rod (4), install the anti-rotation block (18), replace the pressure plate (8) with the groove anti-rotation pressure plate (21), move the loading unit back to its original position, rotate the pressure rod (4) so ​​that the anti-rotation block (18) enters the groove of the groove anti-rotation pressure plate (21), perform a drilling strain method test on the residual stress of the pressing point, and compare the test results with those of the indentation strain method.

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