Temperature-controllable shaft part stress testing device and method

Abstract

The invention discloses a temperature-controllable shaft part stress testing device and method. The shaft part stress testing device comprises a three-dimensional rotary displacement table, a temperature control system and an X-ray diffraction system. The three-dimensional rotary displacement table adopts a composite rotary support structure similar to a gyroscope, and is nested in a temperature control system through three groups of orthogonal U-shaped joint rotary tables, so that a bearing platform with three-dimensional translation and rotation adjustment capabilities is formed, and the omnidirectional measurement of axial, radial and circumferential residual stress of shaft parts can be met. The temperature control system integrates heating and refrigerating functions, the temperature of the cavity can be continuously changed from-50 DEG C to 100 DEG C, and the X-ray diffraction system arranged at the top of the cavity can perform non-contact stress measurement on the to-be-measured part. Through the multi-angle continuous positioning function of the three-dimensional rotary displacement table and in combination with the temperature environment simulation capability of the temperature control system, the device can continuously collect the stress field distribution data of the shaft part in each direction in the service temperature environment under the condition that the part does not need to be disassembled and assembled for many times, and the test efficiency and the detection precision are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of residual stress testing for shaft parts, and particularly relates to a temperature-controlled stress testing device and method for shaft parts. Background Art

[0002] As the core components of modern mechanical equipment, shaft parts are widely used in key fields such as aviation, automotive, shipbuilding, aerospace, and wind power. However, during machining (such as heat treatment, grinding) and under service loads, residual stress concentration is likely to occur inside shaft parts. The existence of residual stress not only induces geometric deformation of the parts, but also significantly reduces the fatigue strength, promotes the initiation and propagation of microcracks; in a specific corrosive medium environment, the coupling effect of residual tensile stress and electrochemical corrosion may further trigger stress corrosion cracking, ultimately leading to catastrophic failure. Therefore, accurately evaluating the residual stress level of shaft parts is not only the core means to prevent failure and ensure the safety of equipment and personnel, but also directly determines their service life and long-term reliability.

[0003] Compared with drilling method, ultrasonic method, etc., X-ray method for stress testing has the characteristics of non-destructiveness and high precision. However, the X-ray method requires the incident X-ray to be at a specific angle with the surface to be measured. Therefore, for samples with complex shapes, the test process requires frequent disassembly of parts to adjust the test surface to achieve full-directional measurement of axial, radial, and circumferential residual stresses. This not only makes the test process cumbersome and inefficient, but also introduces human positioning errors due to mechanical repeated positioning, resulting in deterioration of test accuracy. In addition, due to different service environment temperatures, the residual stresses introduced in shaft parts are different, and existing equipment is difficult to reproduce different service environment temperatures and simultaneously detect the residual stresses of shaft parts.

[0004] The prior art discloses an adjustment tooling for X-ray diffraction testing of residual stresses in bearing parts. Although this tooling can manually adjust the position and angle of the bearing and limit it to achieve the testing of residual stresses in the inner and outer rings of the bearing within a certain size range, its adjustable range is limited and it cannot quickly replace the test surfaces of different parts of the sample to be tested. In the current industry technical system, there is no dedicated tooling and supporting detection method for residual stress testing of shaft parts that can effectively simulate different environmental temperature conditions. Therefore, it is urgent to design a temperature environment field suitable for residual stress testing of shaft parts. Summary of the Invention

[0005] To solve the above problems, the present invention provides a stress testing device for shaft parts with high-precision rapid three-dimensional adaptive adjustment and capable of simulating the service environment temperature, that is, a temperature-controlled stress testing device and method for shaft parts, belonging to the stress testing device for shaft parts with high-precision rapid three-dimensional adaptive adjustment and capable of simulating the service environment temperature. This stress testing device for shaft parts uses a three-dimensional rotary displacement table, a temperature control system, and an X-ray diffraction system, which can quickly and automatically adjust the test surfaces of various parts of the shaft part over a large range, simulate the temperature conditions in its service environment, and achieve the detection of the residual stress of the shaft part, solving the problem of complicated adjustment of the existing method and realizing the technical problem of simulating the service environment temperature of the shaft part in the laboratory.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] According to the first aspect of the technical solution of the present invention, a temperature-controlled stress testing device for shaft parts is provided, including a three-dimensional rotary displacement table, a temperature control system, and an X-ray diffraction system. The three-dimensional rotary displacement table is integrated inside the temperature control system, and the X-ray diffraction system is erected on the top of the temperature control system;

[0008] The three-dimensional rotary displacement table includes an X displacement table, a Y displacement table, a first generation rotary table, a second generation rotary table, a third generation rotary table, and a four-jaw fixed clamp; the generation rotary table has a U-shaped structure. The Y displacement table is connected to the X displacement table through a slide rail. The first generation rotary table is arranged on the base of the Y displacement table. The second generation rotary table is arranged at the U-shaped ends of the first generation rotary table. The third generation rotary table is arranged at the U-shaped bottom of the second generation rotary table. The four-jaw fixed clamp is connected to the U-shaped ends of the third generation rotary table;

[0009] The temperature control system includes a protective outer cover, a heat insulation layer, a heating unit, a liquid nitrogen introduction unit, a nitrogen export unit, a chamber circulation impeller, an interlayer circulation impeller, an X-ray penetration window, and a side switch door; a heat insulation layer is arranged on the inner layer of the protective outer cover, and an interlayer circulation impeller is installed between the protective outer cover and the heat insulation layer; a chamber circulation impeller, a liquid nitrogen introduction unit, and a nitrogen export unit are respectively installed in the middle, upper, and lower positions of the rear wall of the heat insulation layer, and heating units are installed on both sides of the chamber circulation impeller; an X-ray penetration window is provided on the top of the protective outer cover, and a side switch door is equipped on the front side of the protective outer cover.

[0010] Furthermore, the three-dimensional rotary displacement table further includes a Z displacement table;

[0011] A rotary table is provided on the Y displacement table. The first associated rotary table is connected to the rotary table. The two ends of the U-shaped part of the first associated rotary table are respectively connected to the Z displacement table. The second associated rotary table is connected to the inner side of the Z displacement table. The bottom of the second associated rotary table is connected to the first additional displacement table. A third associated rotary table is provided on the upper side of the first additional displacement table. The two ends of the third associated rotary table are connected to the second additional displacement table. A four-jaw fixed fixture is connected to the second additional displacement table.

[0012] Further, the X displacement table drives the Y displacement table to perform translational motion along the X-axis, and the Y displacement table can drive the rotary table to perform Y-axis translation;

[0013] The rotary table drives the first associated rotary table to continuously rotate 360° around the vertical axis Z-axis. The Z displacement table can move parallel to the Z-axis at both ends of the U-shaped part of the first associated rotary table. The Z displacement table can drive the second associated rotary table to continuously swing 180° around the horizontal transverse axis Y-axis;

[0014] The first additional displacement table can perform reciprocating motion on the U-shaped bottom track of the second associated rotary table. The third associated rotary table can continuously rotate 360° around the horizontal longitudinal axis X-axis on the first additional displacement table;

[0015] The second additional displacement table can perform reciprocating motion on the U-shaped ends track of the third associated rotary table. The four-jaw fixed fixture can continuously rotate 360° around its own axis on the second additional displacement table.

[0016] Further, all components included in the three-dimensional rotary displacement table adopt H-class insulated high-temperature-resistant motors to ensure that the three-dimensional rotary displacement table operates continuously at -50°C to +100°C, and the displacement accuracy is 0.01 mm, and the angle positioning accuracy is ±0.01°.

[0017] Further, the clamping surface of the four-jaw fixed fixture is provided with anti-slip micro-textures to stably clamp shaft parts with a diameter ranging from 1 to 100 mm and a length ranging from 10 to 450 mm.

[0018] Further, a high-precision electronic level is set on the bottom plane of the second additional displacement table, and a visual positioning system is arranged around the X-ray penetration window. The initial inclination is detected by the high-precision electronic level, and the three-dimensional rotary displacement table is rotated to achieve the horizontal calibration of the test surface of the shaft part. The visual positioning system is linked to collect the position image of the plane to be measured, so as to achieve automatic calibration and positioning of the spatial position of the plane to be measured, and generate a position adjustment instruction according to the preset path to drive the three-dimensional rotary displacement table to complete the automatic switching of the plane to be measured.

[0019] Further, the bottom of the thermal insulation layer is connected to an external mechanical pump through a first conduit. A first solenoid valve is provided at the external first conduit, and a sealing ring is used at the interface between the first solenoid valve and the first conduit to achieve vacuum sealing.

[0020] A vacuum gauge is provided on the right inner wall of the thermal insulation layer.

[0021] Further, a heating subsystem and a refrigeration subsystem are integrated inside the temperature control system.

[0022] The heating unit of the heating subsystem conveys hot air to the chamber circulation impeller. After being rectified by the chamber circulation impeller, it is evenly distributed throughout the thermal insulation layer and finally returns to the heating unit through the return pipes on both sides of the bottom to complete a closed-loop cycle.

[0023] A third conduit is provided at the rear side of the liquid nitrogen introduction unit of the refrigeration subsystem. A third solenoid valve is provided outside the third conduit, and a sealing ring is used at the interface between the third solenoid valve and the third conduit to achieve vacuum sealing. The third conduit is connected to a liquid nitrogen tank.

[0024] A second conduit is provided at the rear side of the nitrogen gas export unit. A second solenoid valve is installed outside the second conduit, and a sealing ring is used at the interface between the second solenoid valve and the second conduit to achieve vacuum sealing.

[0025] Liquid nitrogen flows into the liquid nitrogen introduction unit through the third conduit. The liquid nitrogen introduction unit vaporizes the liquid nitrogen to achieve temperature reduction, and the nitrogen gas export unit discharges the nitrogen gas through the second conduit.

[0026] Further, a temperature detection and control system is provided at the rear of the temperature control system.

[0027] Temperature sensors are provided inside the four-jaw fixing fixture, below the X-ray transmission window, and outside the fixing table of the Y displacement stage. A control panel is provided on the outer side of the right wall of the temperature control system. The control panel sets a predetermined temperature, and the temperature sensors are used to detect the temperature in real time. The temperature information is fed back to the temperature detection and control system to regulate the temperature inside the thermal insulation layer. Among them, the position image of the plane to be measured collected by the vision positioning system and the vacuum degree sensed by the vacuum machine are displayed on the control panel in real time.

[0028] Among them, the operating temperature range of the temperature control system is -50°C to 100°C, and the temperature control accuracy is ±1°C.

[0029] Further, the X-ray transmission window is encapsulated with a Kapton film, and a heatable hair dryer is installed outside the X-ray transmission window to prevent water vapor from condensing on the Kapton film.

[0030] According to a second aspect of the technical solution of the present invention, a temperature-controllable stress testing method for shaft parts is provided, wherein the stress testing method for shaft parts is operated based on the stress testing device for shaft parts according to any of the above aspects, and the stress testing method for shaft parts comprises:

[0031] 6) Fix the non-test surface of the shaft parts sample with the four-claw fixing fixture of the three-dimensional rotation translation stage, and close the side switch door of the temperature control system;

[0032] 7) Detect the initial inclination, make the test surface of the shaft sample parallel to the X-ray transmission window, and adjust the three-dimensional rotation stage to move the center of the test surface to the center position of the reflection ball of the X-ray diffraction system; set a predetermined simulated ambient temperature, and wait for the temperature in the insulation layer to be constant;

[0033] 8) Starting the X-ray diffraction system, in the process of performing residual stress detection of shaft parts, generating position adjustment instructions according to the preset path, driving the three-dimensional rotational translation stage to automatically switch the test surface, adjusting the three-dimensional rotational translation stage in real time to switch to different test surfaces at different parts, and cooperating with the X-ray diffraction system, thereby obtaining the residual stress distribution of shaft parts;

[0034] 9) After the stress test is completed, the X-ray diffraction system is turned off, the temperature control system is turned off, the three-dimensional rotation stage is adjusted to return to the initial position, and the sample is taken out after the air pressure inside the insulation layer returns to the ambient atmospheric pressure;

[0035] 10) Turn off the power and close the side switch door properly.

[0036] Furthermore, if a test is performed to simulate an environment below room temperature, the first solenoid valve is opened before step 2), air is extracted by a mechanical pump to achieve a low vacuum state in the insulation layer, and a heatable hair dryer is turned on. Here, the heatable hair dryer is used to prevent external water vapor from condensing onto the Kapton film during the low-temperature experiment, thereby preventing the influence of water vapor on the test.

[0037] The present invention adopting the above scheme has at least the following beneficial effects:

[0038] 1. Multi-pose full-domain adaptive adjustment. By designing the three interlocking rotary tables as a gyroscope-like nested parallel mechanism, and matching the X-, Y-, and Z-translation tables, the shaft parts can achieve ultra-large-range X, Y, and Z three-axis linear displacements, as well as six-degree-of-freedom motions of rotation, swing, and rotation around the corresponding axes; since rotation operations around the X, Y, and Z axes can be achieved, shaft parts can be adjusted from a vertical state to a horizontal state (lying flat), and the residual stress at the chamfer position can be measured, thereby achieving omnidirectional measurement of the axial, radial, and circumferential residual stresses of shaft parts.

[0039] 2. Simulation of the service environment temperature of shaft parts. The heating is realized by a hot air blower heating system, the cooling is completed by combining with a liquid nitrogen refrigeration subsystem, the temperature is maintained uniform by continuously agitating the gas through the chamber circulating impeller, and the temperature data is detected and fed back in real time by means of a temperature control system. Finally, stable temperature control with an accuracy of ±1°C is achieved in the range of -50°C to 100°C, and then the temperature environment in which the shaft parts are located during the actual service process is simulated, and the residual stress distribution of the shaft parts under different temperature environment conditions is detected.

[0040] 3. High efficiency and precision. By using a high-precision electronic level and a vision positioning system, it can assist in calibration and collect the images of the position of the plane to be measured, assist in positioning to complete the switching of the plane to be measured, so as to realize automatic calibration and positioning of the spatial position of the plane to be measured, drive the three-dimensional rotary displacement table to complete the automatic switching of the plane to be measured, and then quickly detect the residual stress of different parts of the shaft parts. The global residual stress distribution of the shaft parts can be obtained in a single test. Moreover, the displacement accuracy of the three-dimensional rotary displacement table is 0.01 mm, the angle positioning accuracy is ±0.01°, and the temperature control accuracy of the temperature control system is ±1°C. Brief Description of the Drawings

[0041] To more clearly explain the technical solutions of the specific embodiments of the present invention, the drawings involved in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0042] Wherein:

[0043] Figure 1 It is a front structural schematic diagram of a temperature-controllable stress testing device for shaft parts according to an embodiment of the present invention.

[0044] Figure 2 It is a back structural schematic diagram of a temperature-controllable stress testing device for shaft parts according to an embodiment of the present invention.

[0045] Figure 3 It is a structural schematic diagram of the three-dimensional rotary displacement table of a temperature-controllable stress testing device for shaft parts according to an embodiment of the present invention.

[0046] Figure 4 It is an exploded view of the three-dimensional rotary displacement table of a temperature-controllable stress testing device for shaft parts according to an embodiment of the present invention.

[0047] Figure 5 It is a front structural schematic diagram of the temperature control system of a temperature-controllable stress testing device for shaft parts according to an embodiment of the present invention.

[0048] Figure 6It is a top view partial cross-sectional view of the temperature control system of the temperature-controlled stress testing device for shaft parts according to an embodiment of the present invention.

[0049] In the figure, 1 - three-dimensional rotary displacement stage, 2 - temperature control system, 101 - X displacement stage, 102 - Y displacement stage, 103 - rotary stage, 104 - first generation rotary stage, 105 - Z displacement stage, 106 - second generation rotary stage, 107 - first additional displacement stage, 108 - third generation rotary stage, 109 - second additional displacement stage, 110 - four-jaw fixing fixture, 111 - vision positioning system, 112 - high-precision electronic level, 201 - protective outer cover, 202 - thermal insulation layer, 203 - heating unit, 204 - liquid nitrogen introduction unit, 205 - liquid nitrogen export device, 206 - chamber circulation impeller, 207 - interlayer circulation impeller, 208 - X-ray penetration window, 209 - side switch door, 210 - temperature detection and control system, 211 - control panel, 212 - temperature sensor, 213 - mechanical pump, 214 - first conduit, 215 - first solenoid valve, 216 - third conduit, 217 - third solenoid valve, 218 - liquid nitrogen tank, 219 - second conduit, 220 second solenoid valve, 221 - heatable blower, 222 - X-ray diffraction system. Detailed implementation manners

[0050] The following will explain the implementation manners of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. It should be noted that the drawings attached in the following embodiments are only for illustrative purposes, and the displayed are only schematic diagrams, not actual diagrams, and should not be regarded as a limitation to the present invention. In order to more clearly illustrate the embodiments of the present invention, some components in the figure may be omitted, enlarged or reduced, which does not mean the size of the actual product; for those skilled in the art, the omission of some known structures and their descriptions in the figure is understandable.

[0051] In the embodiments of the present invention, the same or similar numbers in the drawings represent the same or similar components. When explaining the present invention, it should be understood that the directions or positional relationships indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc. are based on the directions or positional relationships in the drawings, and are only for the convenience of explaining the present invention and simplifying the description. These terms describing positional relationships are only exemplary and should not be regarded as any limitation to the present invention. For those of ordinary skill in the art, the specific meanings of these terms can be understood according to the actual situation. In the description of this application, the terms "first", "second", etc. are only used to distinguish different descriptions, and do not mean to indicate or imply relative importance.

[0052] It should be clearly pointed out that the attached drawings in this article are only schematic displays of the basic concept of the present invention. Only the components related to the present invention are presented in the drawings, and they are not drawn according to the number, shape, and size of the components in actual implementation. In fact, the form, number, and proportion of each component can vary arbitrarily during implementation, and the layout form of the components may also be more complex.

[0053] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0054] The present invention first provides a stress testing device for shaft parts with temperature control, including a three-dimensional rotary displacement table, a temperature control system, and an X-ray diffraction system; the three-dimensional rotary displacement table is integrated inside the temperature control system. The X-ray diffraction system is erected on the top of the temperature control system;

[0055] The three-dimensional rotary displacement table includes an X displacement table, a Y displacement table, a first-generation rotary table, a second-generation rotary table, a third-generation rotary table, and a four-jaw fixing clamp; the generation rotary table has a U-shaped structure. The Y displacement table is connected to the X displacement table through a slide rail. The first-generation rotary table is arranged on the base of the Y displacement table. The second-generation rotary table is arranged at the U-shaped ends of the first-generation rotary table. The Y axis is orthogonal to the Z axis. The third-generation rotary table is arranged at the U-shaped bottom of the second-generation rotary table. The four-jaw fixing clamp is connected to the two ends of the U-shaped of the third-generation rotary table;

[0056] The temperature control system includes a protective outer cover, a heat insulation layer, a heating unit, a liquid nitrogen introduction unit, a nitrogen export unit, a chamber circulation impeller, an interlayer circulation impeller, an X-ray penetration window, and a side switch door; a heat insulation layer is configured on the inner layer of the protective outer cover, and an interlayer circulation impeller is installed between the protective outer cover and the heat insulation layer; a chamber circulation impeller, a liquid nitrogen introduction unit, and a nitrogen export unit are respectively installed in the middle, upper, and lower positions of the rear wall of the heat insulation layer. Heating units are installed on both sides of the chamber circulation impeller; an X-ray penetration window is provided on the top of the protective outer cover, and a side switch door is equipped on the front side of the protective outer cover.

[0057] In a preferred embodiment, a rotary table is provided on the Y displacement table, the first-generation rotary table is connected to the rotary table, the two ends of the U-shaped of the first-generation rotary table are respectively connected to the Z displacement table, the second-generation rotary table is connected to the inner side of the Z displacement table, the bottom of the second-generation rotary table is connected to the first additional displacement table, a third-generation rotary table is provided on the upper side of the first additional displacement table, the two ends of the third-generation rotary table are connected to the second additional displacement table, and the four-jaw fixing clamp is connected to the second additional displacement table.

[0058] In a preferred embodiment, the X displacement stage drives the Y displacement stage to perform a translational movement along the X axis. The Y displacement stage can drive the rotary stage to perform a Y-axis translation. The rotary stage drives the first associated rotary stage to continuously rotate 360° around the vertical axis Z. The Z displacement stage can move parallel to the Z axis at both ends of the U shape of the first associated rotary stage. The Z displacement stage can drive the second associated rotary stage to perform a 180° continuous swing around the horizontal transverse axis Y. The X axis is orthogonal to the Y axis. The first additional displacement stage can reciprocate on the U-shaped bottom track of the second associated rotary stage. The third associated rotary stage can continuously rotate 360° around the horizontal longitudinal axis X on the first additional displacement stage. The X axis is orthogonal to the Y axis. The second additional displacement stage can reciprocate on the U-shaped end tracks of the third associated rotary stage. The four-jaw fixed fixture can continuously rotate 360° around its own axis on the second additional displacement stage. Through the X / Y / Z three-axis linear displacement and rotation / swing / rotation around the corresponding axes of the three-dimensional rotary displacement stage, the continuous adjustment of the measured surface of the shaft-like part can be achieved, and the measurement of the axial, radial, and circumferential residual stresses of the shaft-like part can be completed in cooperation with the X-ray diffraction system. In particular, only by rotating the second associated rotary stage by an angle equal to the angle between the chamfer plane and the radial direction of the shaft-like part, the tangential plane of the chamfer can be made parallel to the X-ray transmission window, and the measurement of the residual stress at the chamfer position of the shaft-like part can be realized.

[0059] In a preferred embodiment, the motion drive components of the three-dimensional rotary displacement stage all adopt H-class insulated high-temperature-resistant motors, allowing the three-dimensional rotary displacement stage to continuously operate at -50°C to +100°C, and the displacement accuracy is 0.01 mm, and the angular positioning accuracy is ±0.01°.

[0060] In a preferred embodiment, a four-jaw fixed fixture is connected to the second additional displacement stage. The clamping surface of the four-jaw fixed fixture is provided with anti-slip micro-textures, which can stably clamp shaft-like parts with a diameter ranging from 1 to 100 mm and a length ranging from 10 to 450 mm.

[0061] In a preferred embodiment, a high-precision electronic level is set on the bottom plane of the second additional displacement stage, and a vision positioning system is arranged around the X-ray transmission window. The initial inclination is detected by the high-precision electronic level, and the three-dimensional rotary displacement stage is rotated to achieve the horizontal calibration of the measured surface of the shaft-like part. The position image of the measured plane collected by the linked vision positioning system is used to achieve automatic calibration and positioning of the spatial position of the measured surface, and a position adjustment instruction is generated according to the preset path to drive the three-dimensional rotary displacement stage to complete the automatic switching of the measured surface. The image data is displayed on the control panel in real time.

[0062] In a preferred embodiment, the bottom of the thermal insulation layer is connected to an external mechanical pump through a first conduit. A first solenoid valve is provided at the external conduit. A sealing ring is used to achieve vacuum sealing at the interface between the first solenoid valve and the first conduit. A vacuum gauge is provided on the inner wall on the right side of the thermal insulation layer, and the vacuum degree in its cavity can be displayed on the control panel in real time.

[0063] In a preferred embodiment, the temperature control system internally integrates a heating subsystem and a refrigeration subsystem. The heating unit of the heating subsystem uses a built-in blower to convey the hot air generated by the heating element to the chamber circulation impeller. After being rectified by the chamber circulation impeller, it is evenly distributed throughout the entire thermal insulation layer, and finally returns to the heating unit through the return pipes on both sides of the bottom to complete a closed-loop circulation. A third conduit is provided at the rear side of the liquid nitrogen introduction unit of the refrigeration subsystem. A third solenoid valve is provided outside the third conduit. A sealing ring is used to achieve vacuum sealing at the interface between the third solenoid valve and the third conduit. The third conduit is connected to a liquid nitrogen tank; a second conduit is provided at the rear side of the nitrogen gas discharge unit. A second solenoid valve is installed outside the second conduit. A sealing ring is used to achieve vacuum sealing at the interface between the second solenoid valve and the second conduit. Liquid nitrogen flows into the liquid nitrogen introduction unit through the third conduit. The liquid nitrogen is vaporized by the liquid nitrogen introduction unit to achieve temperature reduction, and the nitrogen gas discharge unit discharges the nitrogen gas through the second conduit.

[0064] In a preferred embodiment, a temperature detection and control system is provided at the rear of the temperature control system. Temperature sensors are provided on the inner side of the four-jaw fixing fixture, below the X-ray transmission window, and outside the fixed table of the Y displacement stage. A control panel is provided on the outer side of the right wall of the temperature control system. The control panel can set a predetermined temperature. The temperature sensors are used to detect the temperature in real time, and the temperature information is fed back to the temperature detection and control system to regulate the temperature inside the thermal insulation layer. The operating temperature range of the temperature control system is -50°C to 100°C, and the temperature control accuracy is ±1°C.

[0065] In a preferred embodiment, the X-ray transmission window is encapsulated with a Kapton film, and a heatable hair dryer is installed on the rear side outside the X-ray transmission window to prevent water vapor from condensing on the Kapton film.

[0066] The technical solution of the present invention also provides a method for stress testing of shaft parts with controllable temperature. Among them, the method for stress testing of shaft parts is based on operating according to the above-mentioned stress testing device for shaft parts. The method for stress testing of shaft parts includes:

[0067] 1) Fix the non-test surface of the shaft part sample with the four-jaw fixing fixture of the three-dimensional rotary displacement stage, and close the side switch door of the temperature control system;

[0068] 2) Detect the initial inclination, make the test surface of the shaft - like sample parallel to the X - ray penetration window, and adjust the three - dimensional rotary displacement stage to move the center of the test surface to the center position of the reflection sphere of the X - ray diffraction system; set a predetermined simulated environmental temperature and wait for the temperature inside the thermal insulation layer to be constant;

[0069] 3) Start the X - ray diffraction system. During the process of detecting the residual stress of shaft - like parts, preset a position adjustment instruction for path generation, drive the three - dimensional rotary displacement stage to complete the automatic switching of the test surface to be measured, adjust the three - dimensional rotary displacement stage in real - time to switch to different test surfaces at different parts, and cooperate with the X - ray diffraction system to obtain the residual stress distribution of shaft - like parts;

[0070] 4) After the stress detection is completed, turn off the X - ray diffraction system, turn off the temperature control system, adjust the three - dimensional rotary displacement stage to return to the initial position. After the air pressure inside the thermal insulation layer returns to the ambient atmospheric pressure, take out the sample;

[0071] 5) Turn off the power supply and properly close the side switch door.

[0072] In a preferred embodiment, if a test for simulating an environment below room temperature is carried out, open the first solenoid valve before step 2), use a mechanical pump to extract air to achieve a low - vacuum state inside the thermal insulation layer, and turn on the heat - able hair dryer.

[0073] Embodiment

[0074] As Figures 1 to 6 shown, the embodiment of the present invention provides a temperature - controllable stress test device for shaft - like parts, including a three - dimensional rotary displacement stage, a temperature control system, and an X - ray diffraction system 222;

[0075] The three-dimensional rotary displacement stage mainly includes an X displacement stage 101, a Y displacement stage 102, a first-generation rotary stage 104, a second-generation rotary stage 106, a third-generation rotary stage 108, and a four-jaw fixed fixture 110. The X displacement stage 101 drives the worm to rotate through the motor at the front top, and then pushes the Y displacement stage 102 to move. The Y displacement stage 102 drives the worm through the motor at the right top to realize the movement of its fixed stage. A rotary stage 103 is provided on the fixed stage, and the first-generation rotary stage 104 is connected to the rotary stage 103. The rotary stage 103 drives the first-generation rotary stage 104 to continuously rotate 360° around the Z axis. The two ends of the U shape of the first-generation rotary stage 104 are respectively connected to the Z displacement stage 105, and motors are assembled on the tops of the two U-shaped ends. These motors drive the worm to realize the movement of the Z displacement stage 105 driving its inner mechanical components parallel to the Z axis. The second-generation rotary stage 106 is connected to the inside of the Z displacement stage 105, and a motor is arranged on the outside to drive the second-generation rotary stage 106 to continuously rotate 180° around the Y axis. The bottom of the second-generation rotary stage 106 is connected to the first additional displacement stage 107, and motors are respectively installed on the front and back sides of the first additional displacement stage 107. These motors drive the gears to reciprocate on the U-shaped bottom track of the second-generation rotary stage 106. The third-generation rotary stage 108 is provided on the upper side of the first additional displacement stage 107, and a motor is arranged at the bottom to drive the third-generation rotary stage 108 to continuously rotate 360° around the X axis. The two ends of the third-generation rotary stage 108 are connected to the second additional displacement stage 109, and motors are respectively installed on the left and right sides of the second additional displacement stage 109. These motors drive the gears to reciprocate on the U-shaped two-end tracks of the third-generation rotary stage 108. The four-jaw fixed fixture 110 is connected to the second additional displacement stage 109, and a motor is arranged at the bottom to drive the four-jaw fixed fixture 110 to rotate 360° along its axis. The clamping surface of the four-jaw fixed fixture 110 is provided with anti-slip micro-textures, which can stably clamp shaft parts with a diameter of 1 to 100 mm and a length of 10 to 450 mm. It can be understood that the three-dimensional rotary displacement stage of the present invention can complete six-degree-of-freedom motions of large-range linear displacements of the X, Y, and Z axes and rotations, swings, and rotations around the corresponding axes, can realize precise adjustment of any part of the axial, radial, and circumferential test surfaces of shaft parts, and cooperate with the X-ray diffraction system 222 to complete residual stress measurement. For the radial test surface of the shaft part in the vertical state, it can be completed by adjusting the X and Y displacements. If it is necessary to measure the axial and circumferential directions of the shaft part, first rotate the second-generation rotary stage 106 by 90°, so as to change the vertical state to the horizontal state, and then use the X or Y displacement to realize the measurement of the axial residual stress. By driving the rotation of the four-jaw fixed fixture 110 through the H-class motor, the measurement of the circumferential residual stress of the shaft part can be completed.If the shaft-like part has a chamfer, it is only necessary to rotate the second-stage rotating table 106 until the chamfer plane forms an angle with the radial direction of the shaft-like part, so that the tangential plane of the chamfer is parallel to the X-ray transmission window 107, thereby realizing the measurement of the residual stress at the chamfer position of the shaft-like part.

[0076] Furthermore, the motion drive components of the three-dimensional rotary displacement table all adopt H-class insulated high-temperature-resistant motors, allowing the three-dimensional rotary displacement table to operate continuously at -50°C to +100°C, with a displacement accuracy of 0.01 mm and an angular positioning accuracy of ±0.01°.

[0077] Furthermore, a high-precision electronic level 112 is provided on the bottom plane of the second additional displacement table 109, and a vision positioning system 111 is arranged around the X-ray transmission window 208. The initial inclination is detected by the high-precision electronic level 112, and the three-dimensional rotary displacement table is rotated to achieve the horizontal calibration of the test surface of the shaft-like part. The position image of the plane to be measured collected by the vision positioning system 111 is linked to realize the automatic calibration and positioning of the spatial position of the plane to be measured, and a position adjustment instruction is generated according to the preset path to drive the three-dimensional rotary displacement table to complete the automatic switching of the plane to be measured. The image data is displayed on the control panel 211 in real time.

[0078] The temperature control system includes a protective cover 201, a thermal insulation layer 202, a heating unit 203, a liquid nitrogen introduction unit 204, a nitrogen gas export unit 205, a chamber circulation impeller 206, an interlayer circulation impeller 207, an X-ray transmission window 208, and a side door 209. The temperature control system includes a thermal insulation layer 202. During the simulation at room temperature below -50°C to 25°C, in a vacuum pumping manner, the thermal insulation layer 202 can form a vacuum environment, thereby preventing water vapor from frosting the sample surface when the liquid nitrogen introduction unit 204 evaporates liquid nitrogen gas, thus affecting the test accuracy. During the simulation of the ambient temperature at 25°C to 100°C, the heating unit 203 blows hot air towards the chamber circulation impeller 206 to achieve hot air circulation, raising the ambient temperature, thereby simulating different ambient temperatures of shaft parts during service. At the bottom of the inner layer of the thermal insulation layer 202, a first conduit 214 is provided, and a first solenoid valve 215 is provided on the first conduit 214. The external mechanical pump 213 of the vacuum system is connected to the thermal insulation layer 202 through the first conduit 214. It can be understood that by opening the first solenoid valve 215, the air inside the thermal insulation layer 202 is extracted to form a low vacuum. In the middle, upper, and lower parts of the rear wall of the thermal insulation layer 202, a chamber circulation impeller 206, a liquid nitrogen introduction unit 204, and a nitrogen gas export unit 205 are respectively provided. The rear part of the liquid nitrogen introduction unit 204 is connected to a liquid nitrogen tank 218 through a third conduit 216, and a third solenoid valve 217 is provided on the third conduit 216 between the liquid nitrogen introduction unit 204 and the liquid nitrogen tank 218. The rear part of the nitrogen gas export unit 205 exports nitrogen gas from the thermal insulation layer 202 through a second conduit 219, and a one-way second solenoid valve 220 is provided on the second conduit 219. It can be understood that during the simulation at room temperature below -50°C to 25°C, by activating the third solenoid valve 216, the liquid nitrogen in the liquid nitrogen tank 218 can be transported to the liquid nitrogen introduction unit 204 through the third conduit 216, thereby starting the evaporation process of liquid nitrogen to reduce the temperature. The rotation speed of the chamber circulation impeller 206 affects the evaporation efficiency of liquid nitrogen and promotes the convective diffusion of nitrogen gas, ensuring a uniform temperature distribution inside the thermal insulation layer 202. The nitrogen gas generated by evaporation is discharged to the external atmosphere through the nitrogen gas export unit 205. Heating units 203 are provided on both the left and right sides of the chamber circulation impeller 206. It can be understood that during the simulation of the ambient temperature at 25°C to 100°C, the heating unit 203 sends hot air to the chamber circulation impeller 206. The chamber circulation impeller 206 promotes the circulation of hot air inside the thermal insulation layer 202, raising the ambient temperature and reducing the temperature gradient to achieve temperature uniformity.

[0079] The temperature control system is composed of a protective cover 201. There is no direct connection between the protective cover 201 and the heat-insulating layer 202, but there is an air layer as a spacer. An interlayer circulation impeller 207 is arranged between the protective cover 201 and the heat-insulating layer 202. In addition, the side switch door 209 also adopts a double-layer structure and contains an air layer communicating with the outside. It can be understood that the rotation of the interlayer circulation impeller 207 drives air to enter from the rear side of the protective cover 201 and then flow out from the space between the protective cover 201 and the heat-insulating layer 202. This design effectively avoids excessive external temperature during the detection of shaft parts, thus protecting the operator from accidental scalding during testing and ensuring the safety of the protective cover and external electronic instrument circuits.

[0080] The temperature control system consists of a temperature detection and control system 210 and a control panel 211. The temperature detection and control system 210 is located at the rear right side of the protective cover 101, while the control panel 211 is installed on the right outer wall of the protective cover 101. Temperature sensors 212 are provided on the inner side of the four-jaw fixing fixture 110, below the X-ray transmission window 208, and outside the fixing table of the Y displacement stage 102. It can be understood that through the control panel 211, the required simulated environmental temperature can be set, the real-time temperature data at three different positions can be monitored, and the temperature information can be fed back to the temperature detection and control system 210. The temperature detection and control system 210 is responsible for adjusting the temperature inside the heat-insulating layer 202 in real time to ensure precise temperature control.

[0081] The shaft sample is placed on the four-jaw fixing fixture 110. The position of the sample is adjusted and the environment is simulated according to the test position and environmental parameters. The X-rays generated by the X-ray diffraction system 222 act on the surface of the sample to obtain experimental data and measure the residual stress at different parts of the shaft part.

[0082] Furthermore, the X-ray transmission window 208 is encapsulated with a Kapton film, and a heatable hair dryer 221 is installed on the rear side outside the X-ray transmission window 208, which avoids the condensation of water vapor on the Kapton film, thus ensuring the accuracy of sample testing.

[0083] In addition, the stress testing method for temperature-controlled shaft parts specifically includes:

[0084] 1) Electrochemical polishing of the sample surface and keeping the sample surface clean to prevent the residual stress introduced during grinding of the sample surface and the additional influence brought by external impurities;

[0085] 2) Connect the stress testing device for temperature-controlled shaft parts to a regulated power supply;

[0086] 3) Fix the non-test surface of the shaft part sample with the four-jaw fixing fixture 110 of the three-dimensional rotary displacement stage and close the side switch door of the temperature control system;

[0087] 4) If a test for simulating an environment below room temperature is to be carried out, it is necessary to open the first solenoid valve 215 and use a mechanical pump to extract air to achieve a low-vacuum state inside the thermal insulation layer 202, and turn on the heatable hair dryer 221; if a test for simulating an environment above room temperature is to be carried out, there is no need to worry about water vapor in the air condensing on the surface of the shaft-like sample due to the evaporation and condensation of liquid nitrogen;

[0088] 5) Use a high-precision electronic level 112 to detect the initial inclination, make the test surface of the shaft-like sample parallel to the X-ray transmission window 208, and use the visual positioning system 111 to control the three-dimensional rotary displacement stage to move the center of the test surface to the center position of the reflection sphere of the X-ray diffraction system 222. Set the predetermined simulated environmental temperature at the control panel 211 and wait for the temperature inside the thermal insulation layer 202 to be constant;

[0089] 6) Start the X-ray diffraction system 222. During the process of detecting the residual stress of the shaft-like part, in the graphics processing module of the control panel 211, preset a path generation position adjustment instruction, drive the three-dimensional rotary displacement stage to complete the automatic switching of the test surface, and adjust the three-dimensional rotary displacement stage in real time to switch to different test surfaces at different parts, and cooperate with the X-ray diffraction system 222 to obtain the residual stress distribution of the shaft-like part. If it is necessary to change the environmental temperature, it can also be adjusted through the control panel. After the temperature inside the thermal insulation layer 202 is stable, the residual stress of the shaft-like part can be measured under the new temperature conditions;

[0090] 7) After the stress detection is completed, turn off the X-ray diffraction system 222, turn off the temperature control system, adjust the three-dimensional rotary displacement stage to return to the initial position, and take out the sample after the air pressure inside the thermal insulation layer 202 returns to the ambient atmospheric pressure;

[0091] Turn off the power supply and properly close the side switch door 108.

[0092] In summary, the technical solution of the present invention provides a temperature-controllable stress testing device and method for shaft-like parts. The three-dimensional rotary displacement stage adopts a gyroscope-like composite rotary support structure, and three groups of orthogonal U-shaped jointed rotary stages are nested inside the temperature control system to form a bearing platform with three-dimensional translation and rotation adjustment capabilities, which can meet the omnidirectional measurement of axial, radial, and circumferential residual stresses of shaft-like parts. The temperature control system integrates heating and cooling functions, and the cavity can continuously change temperature from -50°C to 100°C. The X-ray diffraction system configured on its top can perform non-contact stress measurement on the part to be tested. Through the multi-angle continuous positioning function of the three-dimensional rotary displacement stage and the temperature environment simulation ability of the temperature control system, the device of the present invention can continuously collect the distribution data of the stress fields in all directions of shaft-like parts under the service temperature environment without disassembling and assembling the parts multiple times, significantly improving the test efficiency and detection accuracy.

[0093] The foregoing description has shown and described several preferred embodiments of the present invention. However, as previously mentioned, it should be understood that the present invention is not limited to the forms disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein by the above teachings or the skills or knowledge in the relevant field. Any alterations and changes made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A stress testing device for shaft parts with temperature control, characterized in that It includes a three-dimensional rotary displacement stage, a temperature control system and an X-ray diffraction system. The three-dimensional rotary displacement stage is integrated inside the temperature control system, and the X-ray diffraction system is erected on the top of the temperature control system; The three-dimensional rotary displacement stage includes an X displacement stage, a Y displacement stage, a first-generation rotary stage, a second-generation rotary stage, a third-generation rotary stage, and a four-jaw fixing fixture; the generation rotary stage has a U-shaped structure. The Y displacement stage is connected to the X displacement stage through a slide rail. The first-generation rotary stage is arranged on the base of the Y displacement stage. The second-generation rotary stage is arranged at the U-shaped ends of the first-generation rotary stage. The third-generation rotary stage is arranged at the U-shaped bottom of the second-generation rotary stage. The four-jaw fixing fixture is connected to the two ends of the U-shaped third-generation rotary stage; The temperature control system includes a protective outer cover, a heat insulation layer, a heating unit, a liquid nitrogen introduction unit, a nitrogen export unit, a chamber circulation impeller, an interlayer circulation impeller, an X-ray transmission window, and a side switch door; a heat insulation layer is arranged on the inner layer of the protective outer cover, and an interlayer circulation impeller is installed between the protective outer cover and the heat insulation layer; a chamber circulation impeller, a liquid nitrogen introduction unit, and a nitrogen export unit are respectively installed in the middle and upper and lower positions of the rear wall of the heat insulation layer, and heating units are installed on both left and right sides of the chamber circulation impeller; an X-ray transmission window is provided on the top of the protective outer cover, and a side switch door is equipped on the front side of the protective outer cover.

2. The temperature-controllable stress testing device for shaft parts according to claim 1, wherein The three-dimensional rotary displacement stage further includes a Z displacement stage; A rotary stage is provided on the Y displacement stage, and the first-generation rotary stage is connected to the rotary stage. The two ends of the U-shaped first-generation rotary stage are respectively connected to the Z displacement stage. The inner side of the Z displacement stage is connected to the second-generation rotary stage. The bottom of the second-generation rotary stage is connected to a first additional displacement stage. A third-generation rotary stage is provided on the upper side of the first additional displacement stage. The two ends of the third-generation rotary stage are connected to a second additional displacement stage. The four-jaw fixing fixture is connected to the second additional displacement stage.

3. The controllable-temperature stress testing device for shaft parts according to claim 2, characterized in that, The X displacement stage drives the Y displacement stage to perform translational motion along the X axis, and the Y displacement stage can drive the rotary stage to perform Y-axis translation; The rotary stage drives the first-generation rotary stage to continuously rotate 360° around the vertical axis Z axis. The Z displacement stage can move parallel to the Z axis at both ends of the U-shaped first-generation rotary stage, and the Z displacement stage can drive the second-generation rotary stage to perform a 180° continuous swing around the horizontal transverse axis Y axis; The first additional displacement stage can perform reciprocating motion on the U-shaped bottom track of the second-generation rotary stage, and the third-generation rotary stage can continuously rotate 360° around the horizontal longitudinal axis X axis on the first additional displacement stage; The second additional displacement stage can perform reciprocating motion on the U-shaped two-end tracks of the third-generation rotary stage, and the four-jaw fixing fixture can continuously rotate 360° around its own axis on the second additional displacement stage.

4. The controllable temperature stress testing device for shaft parts according to claim 2, wherein All components included in the three-dimensional rotary displacement stage adopt H-class insulated high-temperature-resistant motors, ensuring that the three-dimensional rotary displacement stage operates continuously at -50°C to +100°C, with a displacement accuracy of 0.01 mm and an angular positioning accuracy of ±0.01°; Among them, the clamping surface of the four-jaw fixing fixture is provided with anti-slip micro-textures to stably clamp shaft parts with a diameter ranging from 1 to 100 mm and a length ranging from 10 to 450 mm.

5. The controllable temperature stress testing device for shaft parts according to claim 2, characterized in that, A high-precision electronic level is arranged on the bottom plane of the second additional displacement table, and a visual positioning system is arranged around the X-ray penetration window. The initial inclination is detected by the high-precision electronic level, and the three-dimensional rotary displacement table is rotated to realize the horizontal calibration of the test surface of the shaft part. The position image of the plane to be measured collected by the visual positioning system is linked to realize the automatic calibration and positioning of the spatial position of the plane to be measured, and a position adjustment instruction is generated according to the preset path to drive the three-dimensional rotary displacement table to complete the automatic switching of the plane to be measured.

6. The controllable-temperature stress testing device for shaft parts according to claim 5, characterized in that, The bottom of the heat preservation layer is connected to an external mechanical pump through a first conduit, and a first solenoid valve is arranged at the external first conduit. A sealing ring is used at the interface between the first solenoid valve and the first conduit to achieve vacuum sealing; A vacuum gauge is arranged on the inner wall on the right side of the heat preservation layer.

7. The temperature-controllable stress testing device for shaft parts according to claim 1, characterized in that, The temperature control system internally integrates a heating subsystem and a refrigeration subsystem; The heating unit of the heating subsystem conveys hot air to the chamber circulation impeller. After being rectified by the chamber circulation impeller, it is evenly distributed throughout the heat preservation layer and finally returns to the heating unit through the return pipes on both sides of the bottom to complete the closed-loop circulation; A third conduit is arranged at the rear side of the liquid nitrogen introduction unit of the refrigeration subsystem. A third solenoid valve is arranged outside the third conduit. A sealing ring is used at the interface between the third solenoid valve and the third conduit to achieve vacuum sealing. The third conduit is connected to a liquid nitrogen tank; A second conduit is arranged at the rear side of the nitrogen gas export unit. A second solenoid valve is installed outside the second conduit. A sealing ring is used at the interface between the second solenoid valve and the second conduit to achieve vacuum sealing; Liquid nitrogen flows into the liquid nitrogen introduction unit through the third conduit. The liquid nitrogen is vaporized by the liquid nitrogen introduction unit to achieve temperature reduction, and the nitrogen gas export unit discharges the nitrogen gas through the second conduit.

8. The controllable-temperature stress testing device for shaft parts according to claim 6, wherein, A temperature detection and control system is arranged at the rear of the temperature control system; Temperature sensors are arranged inside the four-jaw fixing fixture, below the X-ray penetration window, and outside the fixed table of the Y displacement table. A control panel is arranged on the outer side of the right wall of the temperature control system. The control panel sets a predetermined temperature, and the temperature sensors are used to detect the temperature in real time. The temperature information is fed back to the temperature detection and control system to regulate the temperature inside the heat preservation layer; among them, the position image of the plane to be measured collected by the visual positioning system and the vacuum degree sensed by the vacuum machine are displayed on the control panel in real time; Among them, the operating temperature range of the temperature control system is -50°C to 100°C, and the temperature control accuracy is ±1°C.

9. The stress testing device for shaft parts with controllable temperature according to claim 1, characterized in that, The X-ray penetration window is encapsulated with a Kapton film, and a heatable hair dryer is installed outside the X-ray penetration window to prevent water vapor from condensing on the Kapton film.

10. A stress testing method for shaft parts with temperature control, characterized in that, The shaft part stress test method is based on operating according to the shaft part stress test device according to any one of claims 1 to 9. The shaft part stress test method includes: 1) Fix the non-test surface of the shaft part sample with the four-jaw fixing fixture of the three-dimensional rotary displacement table, and close the side switch door of the temperature control system; 2) Detect the initial inclination, make the test surface of the shaft sample parallel to the X-ray transmission window, and adjust the three-dimensional rotary displacement stage to move the center of the test surface to the center position of the reflection sphere of the X-ray diffraction system; set the predetermined simulated environmental temperature and wait for the temperature in the thermal insulation layer to be constant; 3) Start the X-ray diffraction system. During the process of detecting the residual stress of the shaft parts, preset the position adjustment command for path generation, drive the three-dimensional rotary displacement stage to complete the automatic switching of the test surface to be measured, and adjust the three-dimensional rotary displacement stage in real time to switch to different test surfaces at different positions, and cooperate with the X-ray diffraction system to obtain the residual stress distribution of the shaft parts; 4) After the stress detection is completed, turn off the X-ray diffraction system, turn off the temperature control system, adjust the three-dimensional rotary displacement stage to return to the initial position, and take out the sample after the air pressure inside the thermal insulation layer returns to the ambient atmospheric pressure; 5) Turn off the power supply and properly close the side switch door.

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