Mechanical Property Testing Platform

Abstract

The present invention provides a mechanical property test platform. The mechanical property test platform includes a workpiece mounting platform and a hydraulic output system. A hydraulic cylinder is arranged on the workpiece mounting platform. The hydraulic output system includes a hydraulic motor, an electromagnetic directional valve, and a hydraulic oil tank. The hydraulic motor is connected to the input end of the electromagnetic directional valve through a first oil circuit. The output end of the electromagnetic directional valve is connected to the hydraulic oil tank through a second oil circuit. The first interface of the electromagnetic directional valve is connected to the first interface of the hydraulic cylinder through a third oil circuit. The second interface of the electromagnetic directional valve is connected to the second interface of the hydraulic cylinder through a fourth oil circuit. Electro-hydraulic proportional overflow valves are respectively arranged on the third oil circuit and the fourth oil circuit. The liquid outlet of the electro-hydraulic proportional overflow valve is communicated with the hydraulic oil tank. The technical solution of the present invention can effectively solve the problem that it is difficult for the mechanical property test platform in the prior art to accurately simulate a sinusoidal alternating load force.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical property testing, and in particular, to a mechanical property testing platform. Background Art

[0002] With the gradual development of China's rehabilitation aids industry from extensive to intelligent and refined, and the increasing maturity of inspection standards, the test requirements for rehabilitation aids are also getting higher and higher. For example, for knee joint prostheses, not only the ultimate static load needs to be applied to verify the static bearing capacity of the product, but also the spatial sinusoidal alternating load needs to be applied to verify the anti-fatigue ability of the product.

[0003] Generally, there are many ways to generate sinusoidal alternating loads, such as: crank-slider mechanism, eccentric mechanism, static unbalanced rotor mechanism, etc. These are generally hard connections and have poor anti-destruction ability, and are not suitable for the testing of sinusoidal alternating loads of components such as knee joint prostheses. In addition, there is also a method of setting up a hydraulic system pipeline to make the hydraulic cylinder generate a sinusoidal alternating load. However, using the pipeline control method in the existing technology, only an approximately sinusoidal alternating load can be generated, and a strictly sinusoidal alternating load cannot be generated. Moreover, this load force output method has high requirements for the operator's operation and great adjustment difficulty. Summary of the Invention

[0004] The main object of the present invention is to provide a mechanical property testing platform to solve the problem that it is difficult for the mechanical property testing platform in the existing technology to accurately simulate sinusoidal alternating load forces.

[0005] To achieve the above object, the present invention provides a mechanical property testing platform, including: a workpiece mounting platform for mounting a workpiece to be tested for mechanical properties, and a hydraulic cylinder is provided on the workpiece mounting platform for outputting a test load; a hydraulic output system connected to the hydraulic cylinder for outputting hydraulic pressure to the hydraulic cylinder. The hydraulic output system includes a hydraulic motor, an electromagnetic directional valve, and a hydraulic oil tank. The hydraulic motor is connected to the input end of the electromagnetic directional valve through a first oil circuit, the output end of the electromagnetic directional valve is connected to the hydraulic oil tank through a second oil circuit, the first interface of the electromagnetic directional valve is connected to the first interface of the hydraulic cylinder through a third oil circuit, and the second interface of the electromagnetic directional valve is connected to the second interface of the hydraulic cylinder through a fourth oil circuit; an electro-hydraulic proportional relief valve is provided on the third oil circuit and / or the fourth oil circuit, and the liquid outlet of the electro-hydraulic proportional relief valve is connected to the hydraulic oil tank, and the electro-hydraulic proportional relief valve changes the opening degree by adjusting the magnitude of the input current or input voltage.

[0006] In an embodiment, electro-hydraulic proportional relief valves are respectively provided on the third oil circuit and the fourth oil circuit.

[0007] In one embodiment, the electromagnetic directional control valve is an H-type center position function electromagnetic directional control valve. The H-type center position function electromagnetic directional control valve includes: a first working position. In the first working position, the H-type center position function electromagnetic directional control valve connects the first interface of the electromagnetic directional control valve to the input end of the electromagnetic directional control valve, and connects the second interface of the electromagnetic directional control valve to the output end of the electromagnetic directional control valve; a second working position. In the second working position, the H-type center position function electromagnetic directional control valve connects the second interface of the electromagnetic directional control valve to the input end of the electromagnetic directional control valve, and connects the first interface of the electromagnetic directional control valve to the output end of the electromagnetic directional control valve; a third working position. In the third working position, the H-type center position function electromagnetic directional control valve connects the input end of the electromagnetic directional control valve to the output end of the electromagnetic directional control valve.

[0008] In one embodiment, a safety valve is provided on the first oil path, and the liquid outlet of the safety valve is connected to the hydraulic oil tank.

[0009] In one embodiment, the hydraulic output system further includes a motor. The motor is drivingly connected to the hydraulic motor, and the motor is used to provide torque to the hydraulic motor. The hydraulic motor is also connected to the hydraulic oil tank.

[0010] In one embodiment, the workpiece mounting platform includes: a test bench; a fixed loading rod fixedly arranged on the test bench for fixing the first end of the workpiece to be tested for mechanical properties; a movable loading rod movably arranged on the test bench relative to the fixed loading rod for fixing the second end of the workpiece to be tested for mechanical properties; a hydraulic cylinder fixedly arranged on the test bench. The output shaft of the hydraulic cylinder is connected to the movable loading rod and is used to provide a test load to the movable loading rod.

[0011] In one embodiment, the workpiece mounting platform further includes a sliding shaft. The output shaft of the hydraulic cylinder is connected to the movable loading rod through the sliding shaft, and a through-hole component matching with the sliding shaft is arranged on the test bench.

[0012] In one embodiment, the sliding shaft is a ball spline shaft.

[0013] In one embodiment, the workpiece mounting platform further includes a coupling, and the coupling is connected between the output shaft of the hydraulic cylinder and the sliding shaft.

[0014] In one embodiment, the workpiece mounting platform further includes a current / voltage input simulator. The current / voltage input simulator is electrically connected to the electro-hydraulic proportional relief valve and is used to output current / voltage to the electro-hydraulic proportional relief valve. The current / voltage input simulator outputs current / voltage with a corresponding variation mode by simulating the variation mode of the load.

[0015] Applying the technical solution of the present invention, first install the workpiece to be tested for mechanical properties on the workpiece installation platform, and let the hydraulic cylinder output a test load on the workpiece to be tested for mechanical properties. During the process of outputting the load, the hydraulic motor outputs hydraulic pressure, and conveys the output hydraulic pressure to the hydraulic cylinder through the electromagnetic directional valve. The electromagnetic directional valve can switch the oil flow direction to change the movement direction of the output shaft of the hydraulic cylinder. During this process, the hydraulic oil tank is used for oil return. It should be particularly noted that by inputting a sinusoidal alternating current to the electro-hydraulic proportional relief valve, the hydraulic oil pressure in the third oil circuit or the fourth oil circuit will change according to the sinusoidal alternating current, and the adjustable frequency range is large, so that the hydraulic oil pressure input into the hydraulic cylinder cavity changes according to the sinusoidal alternating current, and finally the output shaft of the hydraulic cylinder outputs a sinusoidal alternating thrust. In this way, the problem that it is difficult for the mechanical property test platform in the prior art to accurately simulate the sinusoidal alternating load force can be effectively solved.

[0016] In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0018] Figure 1 shows a schematic structural diagram of a hydraulic output system according to an embodiment of a mechanical property test platform of the present invention;

[0019] Figure 2 shows a schematic structural diagram of a workpiece installation platform according to an embodiment of a mechanical property test platform of the present invention;

[0020] Figure 3 shows Figure 2 an exploded structural diagram of the workpiece installation platform. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0022] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to 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 the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so as to implement the embodiments of the present invention described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0024] It should be noted that the terms used herein are only for describing specific embodiments 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 form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0025] As Figure 1 and Figure 2 shown, the present invention provides an implementation manner of a mechanical property test platform. The mechanical property test platform includes a workpiece mounting platform 10 and a hydraulic output system 20. The workpiece mounting platform 10 is used to mount a workpiece to be tested for mechanical properties. A hydraulic cylinder 11 is provided on the workpiece mounting platform 10, and the hydraulic cylinder 11 is used to output a test load. The hydraulic output system 20 is connected to the hydraulic cylinder 11 and is used to output hydraulic pressure to the hydraulic cylinder 11. The hydraulic output system 20 includes a hydraulic motor 21, an electromagnetic directional control valve 22 and a hydraulic oil tank 23. The hydraulic motor 21 is connected to the input end of the electromagnetic directional control valve 22 through a first oil passage a1. The output end of the electromagnetic directional control valve 22 is connected to the hydraulic oil tank 23 through a second oil passage a2. The first interface of the electromagnetic directional control valve 22 is connected to the first interface of the hydraulic cylinder 11 through a third oil passage a3. The second interface of the electromagnetic directional control valve 22 is connected to the second interface of the hydraulic cylinder 11 through a fourth oil passage a4. Electro-hydraulic proportional overflow valves 24 are respectively provided on the third oil passage a3 and the fourth oil passage a4. The liquid outlet of the electro-hydraulic proportional overflow valve 24 is communicated with the hydraulic oil tank 23, and the electro-hydraulic proportional overflow valve 24 changes the opening degree accordingly by adjusting the magnitude of the input current or input voltage.

[0026] Applying the technical solution of the present invention, first install the workpiece to be tested for mechanical properties on the workpiece installation platform 10, and let the hydraulic cylinder 11 output a test load on the workpiece to be tested for mechanical properties. During the process of outputting the load, the hydraulic motor 21 outputs hydraulic pressure, and conveys the output hydraulic pressure to the hydraulic cylinder 11 through the electromagnetic directional valve 22. The electromagnetic directional valve 22 can switch the oil flow direction to change the movement direction of the output shaft of the hydraulic cylinder 11. During this process, the hydraulic oil tank 23 is used for oil return. It should be particularly noted that by inputting a sinusoidal alternating current to the electro-hydraulic proportional overflow valve 24, the hydraulic oil pressure in the third oil path a3 or the fourth oil path a4 will change sinusoidally, and the adjustable frequency range is large, so that the hydraulic oil pressure input into the cavity of the hydraulic cylinder 11 changes sinusoidally, and finally the output shaft of the hydraulic cylinder 11 outputs a sinusoidal alternating thrust. In this way, the problem that it is difficult for the mechanical property test platform in the prior art to accurately simulate the sinusoidal alternating load force can be effectively solved.

[0027] In addition, it should be noted that the method of adjusting the magnitude of the input current or input voltage may not be limited to the above-mentioned sinusoidal alternating current or sinusoidal alternating voltage, and may also be a current or voltage with other variation modes. For example, by inputting a constant current to the electro-hydraulic proportional overflow valve 24, the hydraulic oil pressure input into the cavity of the hydraulic cylinder 11 remains unchanged, and the output shaft of the hydraulic cylinder 11 outputs a stable thrust.

[0028] More preferably, in the technical solution of the present invention, the workpiece installation platform 10 further includes a current / voltage input simulator, which is electrically connected to the electro-hydraulic proportional overflow valve 24 and is used to output current / voltage to the electro-hydraulic proportional overflow valve 24. The current / voltage input simulator outputs current / voltage with a corresponding variation mode by simulating the variation mode of the load. When in use, by simulating the variation mode of the load through the current / voltage input simulator and outputting current / voltage with a corresponding variation mode, the output shaft of the hydraulic cylinder 11 can output a corresponding test load.

[0029] In the technical solution of the present invention, electro-hydraulic proportional overflow valves 24 are respectively arranged on the third oil path a3 and the fourth oil path a4. In this way, the test load adjustment can be performed for both the pushing stroke and the retracting stroke of the output shaft of the hydraulic cylinder 11. As another optional implementation manner, the electro-hydraulic proportional overflow valve 24 may also be arranged only on the third oil path a3, or only on the fourth oil path a4.

[0030] Such as Figure 1As shown, in the technical solution of this embodiment, the electromagnetic directional valve 22 is an H-type center-position electromagnetic directional valve. The H-type center-position electromagnetic directional valve includes a first working position, a second working position, and a third working position. In the first working position, the H-type center-position electromagnetic directional valve connects the first interface of the electromagnetic directional valve 22 to the input end of the electromagnetic directional valve 22, and connects the second interface of the electromagnetic directional valve 22 to the output end of the electromagnetic directional valve 22; in the second working position, the H-type center-position electromagnetic directional valve connects the second interface of the electromagnetic directional valve 22 to the input end of the electromagnetic directional valve 22, and connects the first interface of the electromagnetic directional valve 22 to the output end of the electromagnetic directional valve 22; in the third working position, the H-type center-position electromagnetic directional valve connects the input end of the electromagnetic directional valve 22 to the output end of the electromagnetic directional valve 22. For Figure 1 example, in the first working position, the H-type center-position electromagnetic directional valve is located at the left working position of the electromagnetic directional valve 22; in the second working position, the H-type center-position electromagnetic directional valve is located at the right working position of the electromagnetic directional valve 22; in the third working position, the H-type center-position electromagnetic directional valve is located at the middle working position of the electromagnetic directional valve 22.

[0031] More preferably, a safety valve 25 is provided on the first oil circuit a1. The liquid outlet of the safety valve 25 is connected to the hydraulic oil tank 23. Through the safety valve 25, the liquid pressure in the pipeline can be prevented from being too high, and the overload protection ability is strong.

[0032] Optionally, as Figure 1 shown, the hydraulic output system 20 further includes a motor 26. The motor 26 is drivingly connected to the hydraulic motor 21. The motor 26 is used to provide torque to the hydraulic motor 21, and the hydraulic motor 21 is also connected to the hydraulic oil tank 23. During use, the motor 26 provides torque to the hydraulic motor 21, driving the hydraulic motor 21 to rotate, and then generating liquid pressure in the first oil circuit a1.

[0033] As Figure 2 and Figure 3 shown, in the technical solution of this embodiment, the workpiece mounting platform 10 includes a test bench 17, a fixed loading rod 12, a movable loading rod 13, and a hydraulic cylinder 11. Among them, the fixed loading rod 12 is fixedly arranged on the test bench 17 and is used to fix the first end of the workpiece to be tested for mechanical properties. The movable loading rod 13 is movably arranged relative to the fixed loading rod 12 on the test bench 17 and is used to fix the second end of the workpiece to be tested for mechanical properties. The hydraulic cylinder 11 is fixedly arranged on the test bench 17, and the output shaft of the hydraulic cylinder 11 is connected to the movable loading rod 13 and is used to provide a test load for the movable loading rod 13. During use, the first end and the second end of the workpiece to be tested for mechanical properties are respectively installed on the fixed loading rod 12 and the movable loading rod 13, and the output shaft of the hydraulic cylinder 11 drives the movable loading rod 13 to move, thereby applying a test load to the workpiece to be tested for mechanical properties.

[0034] More preferably, in order to make the movement of the movable loading rod 13 smoother and along a predetermined straight line, a sliding shaft 14 is further included. The output shaft of the hydraulic cylinder 11 is connected to the movable loading rod 13 through the sliding shaft 14, and a through-hole component 15 matching the sliding shaft 14 is arranged on the test bench 17. More preferably, in the technical solution of this embodiment, the sliding shaft 14 is a ball spline shaft. As other alternative embodiments, the sliding shaft 14 can also be other types of shafts. Preferably, in order to make the connection between the output shaft of the hydraulic cylinder 11 and the sliding shaft 14 more stable, the workpiece mounting platform 10 further includes a coupling 16, and the coupling 16 is connected between the output shaft of the hydraulic cylinder 11 and the sliding shaft 14.

[0035] It should be noted that the technical solution of the mechanical property test platform of the present invention is particularly applicable to the field of prosthetic testing, especially to the mechanical property structure test of knee joint prosthetics.

[0036] Specifically, when the mechanical property test platform of the present invention is applied:

[0037] 1. Output a sinusoidal alternating pressure or a stable pressure between the fixed loading rod 1 and the movable loading rod 13

[0038] The motor 26 converts electrical energy into mechanical energy and inputs it into the hydraulic motor 21. The hydraulic motor 21 converts the low-pressure hydraulic oil in the hydraulic oil tank 23 into high-pressure hydraulic oil and inputs it into the safety valve 25 and the three-position four-way H-type center-position function electromagnetic reversing valve. When the spool of the three-position four-way H-type center-position function electromagnetic reversing valve is in the middle position, the high-pressure hydraulic oil returns to the hydraulic oil tank 23 through the H-type center-position function electromagnetic reversing valve. When the left position of the three-position four-way H-type center-position function electromagnetic reversing valve is connected, the high-pressure hydraulic oil flows from the T port of the H-type center-position function electromagnetic reversing valve to the rodless cavity of the hydraulic cylinder 11 and the corresponding electro-hydraulic proportional overflow valve 24. At this time, the hydraulic oil in the rod cavity of the hydraulic cylinder 11 flows through the H-type center-position function electromagnetic reversing valve to the hydraulic oil tank 23. The electro-hydraulic proportional overflow valve 24 inputs a sinusoidal alternating current, then the pressure of the hydraulic oil input into the rodless cavity of the hydraulic cylinder 11 changes sinusoidally, and the hydraulic cylinder 11 outputs a sinusoidal alternating thrust; the electro-hydraulic proportional overflow valve 24 inputs a constant current, then the pressure of the hydraulic oil input into the rodless cavity of the hydraulic cylinder 11 remains unchanged, and the hydraulic cylinder 11 outputs a stable thrust.

[0039] 2. Output a sinusoidal alternating tension or a stable tension between the fixed loading rod 1 and the movable loading rod 13

[0040] The electric motor 26 converts electrical energy into mechanical energy and inputs it into the hydraulic motor 21. The hydraulic motor 21 converts the low-pressure hydraulic oil in the hydraulic oil tank 23 into high-pressure hydraulic oil and inputs it into the safety valve 25 and the electromagnetic directional valve with H-type center position function. When the spool of the three-position four-way electromagnetic directional valve with H-type center position function is in the center position, the high-pressure hydraulic oil returns to the oil tank through the electromagnetic directional valve with H-type center position function. When the right position of the three-position four-way electromagnetic directional valve with H-type center position function is connected, the high-pressure hydraulic oil flows from the T port of the electromagnetic directional valve with H-type center position function to the rod chamber of the hydraulic cylinder 11 and the corresponding electro-hydraulic proportional relief valve 24. At this time, the hydraulic oil in the non-rod chamber of the hydraulic cylinder 11 flows through the electromagnetic directional valve with H-type center position function to the hydraulic oil tank 23. If a sinusoidal alternating current is input to the electro-hydraulic proportional relief valve 24, the pressure of the hydraulic oil input to the rod chamber of the hydraulic cylinder 11 changes sinusoidally, and the hydraulic cylinder 11 outputs a sinusoidal alternating tensile force; if a constant current is input to the electro-hydraulic proportional relief valve 24, the pressure of the hydraulic oil input to the rod chamber of the hydraulic cylinder 11 remains unchanged, and the hydraulic cylinder 11 outputs a constant tensile force.

[0041] 3. Apply spatial load

[0042] The output shaft of the hydraulic cylinder 11 is connected to the ball spline through the coupling 16. The coupling 16 can adjust the non-coaxial problem between the output shaft of the hydraulic cylinder 11 and the spline shaft of the ball spline and can transmit thrust or tensile force. The spline shaft of the ball spline is fixedly connected to the movable loading rod 13. One end of the movable loading rod 13 is fixedly connected to the test sample, and the other end of the test sample is fixedly connected to the fixed loading rod 11. The fixed loading rod 11 is fixedly connected to the test bench 17. The lengths of the fixed loading rod 11 and the movable loading rod 13 are different, and there is a relative angle, so as to realize the application of spatial load to the test sample.

[0043] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0044] 1. The mechanical property test platform of the present invention can apply a strictly sinusoidally varying pressure or tensile force, and can also apply a stable pressure or tensile force.

[0045] 2. For the mechanical property test platform of the present invention, only by changing the amplitude and frequency of the input current of the electro-hydraulic proportional valve, the amplitude and frequency of the output force can be changed. The parameter adjustment is simple and fast, and the adjustment range is wide.

[0046] 3. The mechanical property test platform of the present invention can apply spatial load. By changing the lengths and relative angles of the upper and lower loading rods, the spatial position of the spatial load can be changed.

[0047] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical 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 authorization specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, further discussion thereof is not required in subsequent drawings.

[0048] For the sake of convenience of description, spatial relative terms such as "above", "on top of", "on the upper surface", "above-mentioned", etc. may be used herein to describe the spatial positional relationship between one device or feature and other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawing is inverted, a device described as "above" or "on top of" other devices or structures will then be positioned "below" or "beneath" the other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations will be made for the spatial relative descriptions used herein.

[0049] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom", etc. is generally based on the orientation or positional relationship shown in the drawings, and is 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, and thus should not be construed as limiting the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0050] The above description is only the preferred embodiments of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A mechanical property testing platform, characterized in that, Comprising: A workpiece mounting platform (10) for mounting a workpiece to be subjected to mechanical property testing, wherein a hydraulic cylinder (11) is provided on the workpiece mounting platform (10), and the hydraulic cylinder (11) is used to output a test load; A hydraulic output system (20) connected to the hydraulic cylinder (11) for outputting hydraulic pressure to the hydraulic cylinder (11). The hydraulic output system (20) includes a hydraulic motor (21), an electromagnetic directional valve (22), and a hydraulic oil tank (23). The hydraulic motor (21) is connected to the input end of the electromagnetic directional valve (22) through a first oil path (a1). The output end of the electromagnetic directional valve (22) is connected to the hydraulic oil tank (23) through a second oil path (a2). The first interface of the electromagnetic directional valve (22) is connected to the first interface of the hydraulic cylinder (11) through a third oil path (a3). The second interface of the electromagnetic directional valve (22) is connected to the second interface of the hydraulic cylinder (11) through a fourth oil path (a4); An electro-hydraulic proportional relief valve (24) is provided on the third oil path (a3) and / or the fourth oil path (a4). The liquid outlet of the electro-hydraulic proportional relief valve (24) is communicated with the hydraulic oil tank (23), and the electro-hydraulic proportional relief valve (24) changes the opening degree correspondingly by adjusting the magnitude of the input current or input voltage; The electromagnetic directional valve (22) is an H-type center-position function electromagnetic directional valve, and the H-type center-position function electromagnetic directional valve includes: A first working position. In the first working position, the H-type center-position function electromagnetic directional valve connects the first interface of the electromagnetic directional valve (22) to the input end of the electromagnetic directional valve (22), and connects the second interface of the electromagnetic directional valve (22) to the output end of the electromagnetic directional valve (22); A second working position. In the second working position, the H-type center-position function electromagnetic directional valve connects the second interface of the electromagnetic directional valve (22) to the input end of the electromagnetic directional valve (22), and connects the first interface of the electromagnetic directional valve (22) to the output end of the electromagnetic directional valve (22); A third working position. In the third working position, the H-type center-position function electromagnetic directional valve connects the input end of the electromagnetic directional valve (22) to the output end of the electromagnetic directional valve (22); The workpiece mounting platform (10) includes: A test bench frame (17); A fixed loading rod (12) fixedly provided on the test bench frame (17) for fixing the first end of the workpiece to be subjected to mechanical property testing; A movable loading rod (13) movably provided relative to the fixed loading rod (12) on the test bench frame (17) for fixing the second end of the workpiece to be subjected to mechanical property testing; A hydraulic cylinder (11) fixedly provided on the test bench frame (17). The output shaft of the hydraulic cylinder (11) is connected to the movable loading rod (13) for providing the test load to the movable loading rod (13).

2. The mechanical property test platform according to claim 1, characterized in that Electro-hydraulic proportional relief valves (24) are respectively provided on the third oil path (a3) and the fourth oil path (a4).

3. The mechanical property test platform according to claim 1, characterized in that, A safety valve (25) is provided on the first oil circuit (a1), and the liquid outlet of the safety valve (25) is communicated with the hydraulic oil tank (23).

4. The mechanical property test platform according to claim 1, characterized in that The hydraulic output system (20) further includes a motor (26), the motor (26) is drivingly connected to the hydraulic motor (21), the motor (26) is used to provide torque to the hydraulic motor (21), and the hydraulic motor (21) is also connected to the hydraulic oil tank (23).

5. The mechanical property test platform according to claim 4, characterized in that, The workpiece mounting platform (10) further includes a sliding shaft (14), the output shaft of the hydraulic cylinder (11) is connected to the movable loading rod (13) through the sliding shaft (14), and a through-hole component (15) matching with the sliding shaft (14) is provided on the test bench (17).

6. The mechanical property test platform according to claim 5, wherein, The sliding shaft (14) is a ball spline shaft.

7. The mechanical property test platform according to claim 5, characterized in that The workpiece mounting platform (10) further includes a coupling (16), and the coupling (16) is connected between the output shaft of the hydraulic cylinder (11) and the sliding shaft (14).

8. The mechanical property test platform according to claim 1, characterized in that, The workpiece mounting platform (10) further includes a current / voltage input simulator, the current / voltage input simulator is electrically connected to the electro-hydraulic proportional relief valve (24) and is used to output current / voltage to the electro-hydraulic proportional relief valve (24), and the current / voltage input simulator outputs current / voltage with a corresponding change mode by simulating the change mode of the load.

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