Thermal fatigue test device and test method

Abstract

The invention provides a thermal fatigue test device and a test method, and relates to the technical field of part test. The thermal fatigue test device comprises a heating test simulation device, the heating test simulation device is provided with a heating working face and a bottom face which are oppositely arranged in the thickness direction, the heating test simulation device is provided with a working position for carrying out heating test simulation on a test object, and the test object at least comprises a test cylinder cover. When the heating test simulation device is located at the working position, the heating working surface faces the test object, and the distances between the heating working surface and the bottom surface are unequally arranged in the extension direction of the heating working surface, so that a temperature gradient field is formed on the surface of the test object in the test process of the test object. According to the scheme, the thermal fatigue environment in the actual operation of the engine can be accurately simulated, the temperature distribution of the cylinder cover during the working of the engine is reflected, the optimization of the material selection and the structural design of the cylinder cover is facilitated, and data support is provided for the improvement of the performance and the reliability of the cylinder cover.

Description

Technical Field

[0001] The present invention relates to the technical field of component testing, and in particular to a thermal fatigue testing device and a testing method. Background Art

[0002] Due to the complex structure of the engine cylinder head, the cylinder head is subjected to high temperature and high pressure during the diesel engine working cycle (intake-compression-combustion-exhaust), which increases the risk of cracking, directly leading to increased market quality costs and damage to the company's brand. The cylinder head is also the only key part of the engine that does not have a special test.

[0003] At present, the fatigue of engine cylinder heads is tested by bench thermal shock tests to study the damage caused by the cooling and heating process of the cylinder heads. This is costly and time-consuming, and this test cannot be performed in the early stages of engine cylinder head development. In the prior art, due to the particularity of the research and development object and process, the current induction heating device or flame heating cannot achieve accelerated and accurate simulation of the temperature difference on the bottom surface of the cylinder head.

[0004] Currently, no effective solution has been proposed for the above-mentioned technical problems. Summary of the invention

[0005] The main purpose of the present invention is to provide a thermal fatigue test device and a test method to solve the problem in the prior art that it is impossible to accelerate and accurately simulate the temperature gradient change when the cylinder head is working.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a thermal fatigue test device is provided, comprising: a heating test simulation device, the heating test simulation device having a heating working surface and a bottom surface relatively arranged along the thickness direction, the heating test simulation device having a working position for performing a heating test simulation on a test object, the test object at least comprising a test cylinder head, when the heating test simulation device is in the working position, the heating working surface is arranged toward the test object, and the distance between the heating working surface and the bottom surface is arranged unequally along the extension direction of the heating working surface, so that a temperature gradient field is formed on the surface of the test object during the test.

[0007] Furthermore, the heating test simulation device is an induction heating device.

[0008] Furthermore, the heating test simulation device is a disc-shaped structure.

[0009] Furthermore, the heating working surface includes a first working surface and a second working surface which are sequentially arranged radially outward from the heating working surface, wherein, along the radial outward direction of the heating working surface, the distance between the first working surface and the bottom surface is arranged unchanged, and the distance between the second working surface and the bottom surface is arranged to gradually decrease.

[0010] Furthermore, when the heating test simulation device is in the working position, along the thickness direction of the heating test simulation device, the projection of the first working surface covers the nose bridge area of ​​the test cylinder head, wherein the nose bridge area is the area between two adjacent cylinder holes on the test cylinder head.

[0011] Furthermore, the heating test simulation device has a heating assembly, which includes a plurality of annular heating elements spaced apart and arranged radially outwardly along the heating working surface.

[0012] Furthermore, the thermal fatigue test device also includes: a cooling test simulation device, the cooling test simulation device has at least one air flow nozzle, and the air flow nozzle is used to spray cooling air flow to the test object to cool the test object.

[0013] Furthermore, the thermal fatigue testing device further comprises: a temperature detection device, and the temperature detection device is used to detect the temperature of the test object.

[0014] According to another aspect of the present invention, a thermal fatigue test method is provided, which adopts the above-mentioned thermal fatigue test device to perform the test, and the method comprises the following steps: using a heating test simulation device and a cooling test simulation device to perform a preset number of thermal cycle treatments on a test object, and obtaining test data of the test object, the test data at least including temperature data of the test object, duration data of the thermal cycle treatment, and surface physical change data of the test object; based on the test data, evaluating the thermal fatigue performance of the test object.

[0015] Furthermore, a single thermal cycle treatment includes the following steps: placing the heating test simulation device in a working position, and using the heating test simulation device to heat the test object; when it is determined that the temperature of the test object meets the first temperature condition, using the cooling test simulation device to cool the test object until the temperature of the test object meets the second temperature condition.

[0016] By applying the technical solution of the present invention, the heating working surface and the bottom surface are set at different distances. Since it is difficult to adjust the current and heating time of the heating test simulation device to form a temperature field with different local temperatures during the heating process, the heating distance and the test object are set to different distances, so that the heating power in different areas can be changed to conveniently achieve the required temperature field distribution. When the heating test simulation device is in the working position, the heating working surface is heated toward the test object. Under the same current and time, a temperature gradient is generated on the entire heating working surface due to the different distances between the heating working surface and the test object, thereby forming a temperature gradient field on the surface of the test object. When the test object is a test cylinder head, the thermal fatigue environment in the actual operation of the engine can be accurately simulated. When the engine is started and shut down, the temperature change differences in different areas on the test cylinder head can be accurately simulated, reflecting the temperature distribution of the cylinder head when the engine is working, which is helpful to optimize the material selection and structural design of the cylinder head, and provide data support for improving the performance and reliability of the cylinder head. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0018] Figure 1 It shows a schematic structural diagram of a first embodiment of a thermal fatigue testing device according to the present invention;

[0019] Figure 2 It shows a schematic structural diagram of a second embodiment of a thermal fatigue testing device according to the present invention;

[0020] Figure 3 A schematic diagram showing the surface temperature distribution of a cylinder head according to the cylinder head thermal fatigue test method of the present invention is shown;

[0021] Figure 4 A flow chart showing an embodiment of a thermal fatigue test method according to the present invention.

[0022] The above drawings include the following reference numerals:

[0023] 20. Heating test simulation device;

[0024] 21. Heating working surface; 211. First working surface; 212. Second working surface;

[0025] 22. Bottom surface. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] 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 "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in a variety of different forms and should not be construed as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of the layers and regions may be enlarged, and the same reference numerals are used to represent the same devices, and thus their descriptions will be omitted.

[0030] To illustrate the effect of the thermal fatigue test device in this application, the conventional high-frequency induction heating coil in the prior art is used for explanation: the conventional high-frequency induction heating coil: 1) only heats the nose bridge area locally, and the temperature spreads inward and outward through the nose bridge area, and it is impossible to heat the entire surface at the same time; 2) the temperature field distribution of the heating surface is not controlled, and temperature simulation is difficult; 3) there is a lack of correlation between engine thermal shock and cylinder head fatigue test. Moreover, the temperature rise of the actual cylinder head surface is different from the temperature state distribution generated by the conventional heating coil in the prior art.

[0031] Combination Figures 1 to 3As shown, according to a specific embodiment of the present application, a thermal fatigue testing device is provided.

[0032] Specifically, Figure 1 , Figure 2 As shown, the thermal fatigue test device includes a heating test simulation device 20, the heating test simulation device 20 has a heating working surface 21 and a bottom surface 22 arranged relatively to each other along the thickness direction, the heating test simulation device 20 has a working position for performing a heating test simulation on a test object, the test object at least includes a test cylinder head, when the heating test simulation device 20 is in the working position, the heating working surface 21 is arranged toward the test object, and, along the extension direction of the heating working surface 21, the distance between the heating working surface 21 and the bottom surface 22 is arranged unequally, so that a temperature gradient field is formed on the surface of the test object during the test.

[0033] By applying the technical solution of this embodiment, the heating working surface 21 and the bottom surface 22 are set at different distances. Since it is difficult to adjust the current and heating time of the heating test simulation device 20 to form a temperature field with different local temperatures during the heating process, the heating distance and the test object are set to different distances, so that the heating power in different areas can be changed to conveniently achieve the required temperature field distribution. When the heating test simulation device 20 is in the working position, the heating working surface 21 heats the test object. Under the same current and time, a temperature gradient is generated on the entire heating working surface 21 due to the different distances between the heating working surface 21 and the test object, thereby forming a temperature gradient field on the surface of the test object. When the test object is a test cylinder head, the thermal fatigue environment in the actual operation of the engine can be accurately simulated. When the engine is started and shut down, the temperature change differences in different areas on the test cylinder head can be accurately simulated, reflecting the temperature distribution of the cylinder head when the engine is working, which helps to optimize the material selection and structural design of the cylinder head and provide data support for improving the performance and reliability of the cylinder head.

[0034] It should be noted that, depending on the test object and the test conditions, the heating test simulation device 20 can have a variety of working positions, and the distance between the heating test simulation device 20 and the test object is different in different working positions. For example, when heating the test object, the heating test simulation device 20 can be placed in different working positions to simulate a variety of engine conditions, so that the performance evaluation of the cylinder head is more accurate and comprehensive.

[0035] Those skilled in the art should understand that the heating test simulation device 20 can also be applied to test objects other than cylinder heads, and is particularly suitable for test objects with high requirements on temperature performance, such as vehicle pistons, crankshafts, superchargers, transmissions, brake discs, radiators, etc. For different test objects, the distance change between the heating working surface 21 and the bottom surface 22 on the heating test simulation device 20 can be adaptively adjusted so that the heating test simulation device 20 can form a corresponding temperature gradient field on the surfaces of different test objects.

[0036] Specifically, the heating test simulation device 20 is an induction heating device. By using induction heating, the heating temperature can be controlled more quickly, accurately and evenly by controlling the current and heating time, so that the temperature gradient distribution on the heating working surface 21 is more even. At the same time, by accurately controlling the heating power, the heat load of the engine under different working conditions can be simulated, thereby improving the accuracy and reliability of the test.

[0037] Alternatively, if Figure 1 As shown, the heating test simulation device 20 is a disc-shaped structure. The design of the disc-shaped structure enables the heating test simulation device 20 to better fit the shape of the test cylinder head, ensure the uniformity and efficiency of heating, and is suitable for cylinder head tests of different sizes and shapes, thereby improving the practicality of the heating test simulation device 20. At the same time, the disc-shaped structure matches the shape of the actual engine cylinder head, and can simulate a more realistic temperature distribution of the engine cylinder head. It should be noted that the structure and size of the heating test simulation device 20 can be adjusted accordingly according to different models of engine cylinder heads to improve the practicality of the heating test simulation device 20, and can also be adjusted according to the surface shape of different test objects.

[0038] Furthermore, if Figure 2 As shown, the heating working surface 21 includes a first working surface 211 and a second working surface 212 sequentially arranged radially outward from the heating working surface 21, wherein, along the radially outward direction of the heating working surface 21, the distance between the first working surface 211 and the bottom surface 22 is arranged to be constant, and the distance between the second working surface 212 and the bottom surface 22 is arranged to be gradually reduced. In this way, a more complex temperature gradient field can be formed to simulate the temperature distribution of the cylinder head when the engine is running, and at the same time, the more drastic temperature change in the edge area of ​​the cylinder head can be simulated, so that the staff can have a deeper understanding of the thermal stress and material of the cylinder head.

[0039] It should be noted that the distances between the first working surface 211, the second working surface 212 and the bottom surface 22 can be set differently according to different models of engine cylinder heads, and the distances between the first working surface 211, the second working surface 212 and the bottom surface 22 can be set differently according to the simulation of different engine operating conditions. For example, under different operating conditions such as engine idling, full load, acceleration, deceleration, cold start, overheating, etc., different degrees of thermal stress are generated on the cylinder head. Therefore, the temperature distribution of the cylinder head under different operating conditions can be simulated to set the distances between the first working surface 211, the second working surface 212 and the bottom surface 22.

[0040] In this embodiment, if Figure 2 As shown, in the cross section along the thickness direction of the heating test simulation device 20, the heating working surface 21 and the bottom surface 22 are arranged in a trapezoidal shape, the heating working surface 21 corresponds to the top surface and waist of the trapezoid, the bottom surface 22 corresponds to the bottom surface of the trapezoid, and the heating working surface 21 is arranged at different distances from the bottom surface 22 along the extension direction of the waist of the trapezoid.

[0041] Specifically, when the heating test simulation device 20 is in the working position, the projection of the first working surface 211 covers the nose bridge area of ​​the test cylinder head along the thickness direction of the heating test simulation device 20, wherein the nose bridge area is the area between two adjacent cylinder holes on the test cylinder head. According to the actual situation, the simulation is performed. The nose bridge area of ​​the cylinder head is the area where the cylinder head is subjected to the largest and most concentrated thermal stress. Since the first working surface 211 is closest to the test cylinder head, the heat generated on the test cylinder head corresponding to the first working surface 211 is the largest. Therefore, the first working surface 211 is tested corresponding to the nose bridge area, which can focus on the nose bridge area, accurately evaluate the thermal fatigue performance of the cylinder head in the nose bridge area, and realize in-depth research on the thermal fatigue performance of the cylinder head in the nose bridge area.

[0042] In this embodiment, the first working surface 211 is arranged corresponding to the nose bridge area of ​​the test cylinder head. When the heating test simulation device 20 is in the working position, the temperature of the nose bridge area of ​​the test cylinder head is the highest, and the distance between the second working surface 212 and the test cylinder head gradually increases, and the corresponding temperature decreases along the circumference of the nose bridge area.

[0043] Furthermore, the heating test simulation device 20 has a heating assembly, which includes a plurality of annular heating elements spaced apart and arranged radially outwardly along the heating working surface 21. Figure 1 As shown, along the radial direction of the heating working surface 21, the distance between the second working surface 212 and the bottom surface 22 is different, that is, the distance between the second working surface 212 and the test object is different. By using an annular heating element arranged on the heating working surface 21, the heating working surface 21 at the same position from the test object can generate uniform heat radiation, so that the simulation of different temperature gradients can be achieved only by controlling the distance between the heating working surface 21 and the test object.

[0044] In one embodiment of the present application, multiple annular heating elements are arranged in series. The annular heating elements arranged in series can ensure the uniformity and controllability of heating. The temperature of the entire heating assembly can be adjusted by simply adjusting the current of the annular heating element. By adjusting the power of the heating element, the temperature distribution of the cylinder head when the engine is running can be simulated, and the heating process can be uniformly controlled. Optionally, multiple annular heating elements can also be arranged in parallel to more accurately adjust the temperature of the heating working surface.

[0045] Furthermore, the thermal fatigue test device also includes a cooling test simulation device, which has at least one airflow nozzle, and the airflow nozzle is used to spray cooling airflow to the test object to cool the test object. The cooling test simulation device can simulate the cooling effect of the engine during operation, and the cooling airflow sprayed by the airflow nozzle can achieve rapid cooling of the test object. The effect of rapid cooling on the thermal fatigue performance of the test object can be used together to evaluate the material of the test object and the thermal stress of the test object.

[0046] Furthermore, the thermal fatigue test device also includes a temperature detection device, which is used to detect the temperature of the test object. The temperature monitoring device can monitor the temperature change of the test object in real time and record the temperature of the test object to provide data support for evaluating the thermal fatigue performance of the test object.

[0047] In one embodiment of the present application, the temperature measuring sensor is a highly responsive thermocouple sensor to improve the temperature measurement accuracy of the temperature field.

[0048] It should be noted that the temperature sensor can monitor and record the temperature change at the same position on the test object in real time, and can also monitor and record the different temperature distribution conditions at different positions on the test object at the same time, thereby forming and providing a detailed thermal stress report of the test object. At the same time, the temperature sensor can detect and record the temperature of the test object when the heating test simulation device 20 and the cooling test simulation device are working respectively, so as to ensure that the heating test simulation device 20 and the cooling test simulation device work stably according to the preset instructions, and avoid overheating or overcooling from having a negative impact on the test.

[0049] like Figure 4 As shown, according to another specific embodiment of the present application, a thermal fatigue test method is also provided. The method uses the thermal fatigue test device in the above embodiment to perform the test. The method includes the following steps:

[0050] Step S10, using the heating test simulation device 20 and the cooling test simulation device to perform a preset number of thermal cycle treatments on the test object, and obtaining test data of the test object, the test data at least including temperature data of the test object, duration data of the thermal cycle treatment, and surface physical change data of the test object;

[0051] Specifically, the test object is subjected to a preset number of thermal cycle treatments, which can be determined based on the expected service life and operating conditions of the test object. The thermal cycle treatment includes heating the test object using a heating test simulation device 20, and then cooling the test object using a cooling test simulation device. This is one cycle of thermal cycle treatment. The test data of the test object is recorded after each thermal cycle treatment. After the preset number of thermal cycle treatments are performed, the test data is summarized.

[0052] It should be noted that the temperature data may be temperature change data, i.e., different data generated by temperature changes over time; the duration data of thermal cycle treatment includes the number of thermal cycle treatments, the duration of each thermal cycle treatment, and the total duration of thermal cycle treatment; the surface physical change data of the test object are data on physical changes such as cracks, deformation, hardness, roughness, and thermal expansion coefficient that occur in the test object.

[0053] Step S12: evaluating the thermal fatigue performance of the test object based on the test data.

[0054] Specifically, after the above data are summarized, the thermal fatigue performance of the test object is evaluated based on the parameters of each test object.

[0055] Through the above steps, the heating test simulation device 20 and the cooling test simulation device are used to perform a preset number of thermal cycle treatments on the test object, and the test data of the test object are obtained, and the test data at least includes the temperature data of the test object, the duration data of the thermal cycle treatment, and the surface physical change data of the test object; based on the test data, the thermal fatigue performance of the test object is evaluated. When the test object is a test cylinder head, the thermal fatigue performance of the cylinder head can be accurately evaluated by simulating the thermal cycle in the actual operation of the engine. Based on the evaluation results, the staff improves the material, design and manufacturing process of the cylinder head, thereby improving the performance and reliability of the engine, reducing the maintenance cost of the engine, and ensuring that the engine can maintain a stable working state under various complex working conditions to extend the life of the engine.

[0056] Optionally, in step S10, a single thermal cycle process includes the following steps:

[0057] Step S101, placing the heating test simulation device 20 in a working position, and using the heating test simulation device 20 to heat the test object;

[0058] Specifically, when the test object is a test cylinder head, a temperature gradient field is formed by heating the test simulation device 20 to simulate the temperature distribution of the cylinder head when the engine is working.

[0059] Step S102, when it is determined that the temperature of the test object meets the first temperature condition, the test object is cooled by using a cooling test simulation device until the temperature of the test object meets the second temperature condition.

[0060] Specifically, during a thermal cycle treatment process, the test object is first heated and then cooled. The first temperature condition is a preset temperature to be reached after the test object is heated, and the second temperature condition is a preset temperature to be reached after the test object is cooled.

[0061] It should be noted that during the heat treatment of the test object, the temperature of the test object is detected in real time. After the temperature of the test object reaches a first temperature condition, a cold treatment is performed to cool it down. After the temperature of the test object drops to a second temperature condition, a thermal cycle treatment is completed.

[0062] The present application also provides a preferred embodiment of a cylinder head thermal fatigue test method, which rapidly heats and cools the cylinder head by means of high-frequency electromagnetic induction and compressed air forced cooling, so that the working heated area of ​​the cylinder head produces a temperature field change required by the experiment. The operating steps of the cylinder head thermal fatigue test method in this embodiment are as follows:

[0063] Step 1: Conduct cylinder head temperature field calibration research, such as Figure 3 As shown, the temperature relationship between engine thermal shock test and cylinder head fatigue is established;

[0064] Step 2: Perform finite element analysis on the cylinder head under test to determine the point-surface relationship of the temperature field distribution of the cylinder head under thermal fatigue test;

[0065] Among them, Finite Element Analysis (FEA) is a numerical simulation technology. Finite element analysis is performed on the cylinder head under test, and differential equations of points and surfaces of temperature field distribution of the cylinder head under thermal fatigue test are established. The temperature distribution at different positions of the entire cylinder head is obtained through numerical solution.

[0066] Step 3: Composite manufacturing of a heating plate that meets the requirements based on finite element design;

[0067] Among them, a heating plate with a non-flat and regular heating surface is designed mainly based on the actual temperature calibration data of the engine cylinder head and the simulation calculation of the firing surface temperature. In the working state, the nose bridge area is closest to the heating plate, and the heating rate of this area is faster. The heating distances of other areas are different, and the required temperature distribution has been established.

[0068] Step 4: Process and calibrate the cylinder head and arrange the temperature sensor on the test piece;

[0069] Step 5: Use a customized pancake inductor and compressed air nozzle to heat and cool the test piece to carry out the cylinder head thermal fatigue test life test;

[0070] Step 6: Statistical analysis of the test results. Use Weibull and other statistical techniques to analyze the life of the cylinder head at different confidence levels. Perform horizontal comparison to evaluate the consistency of the cylinder head thermal fatigue life test and vertical comparison to evaluate the prediction accuracy of the cylinder head thermal fatigue life.

[0071] Among them, according to the damage mechanism, the acceleration relationship of different operating conditions under the same boundary conditions is analyzed to improve the test efficiency; this method is used to test the cylinder head life before and after improvement, before and after assembly constraints, and analyze the relative life relationship between them, and compare them with the relative life relationship of finite element calculation results. The horizontal comparison is used to evaluate the consistency of the cylinder head thermal fatigue life test, and the vertical comparison is used to evaluate the accuracy of the cylinder head thermal fatigue life prediction.

[0072] Compared with the prior art, the above cylinder head thermal fatigue test device and test method have the following principles:

[0073] According to the diesel engine cylinder head thermal fatigue test method, at least 10 temperature measurement points need to be covered on the cylinder head fire surface at least during the early calibration to ensure the temperature rise rate, such as Figure 3 As shown, Figure 3 Mark the distribution of temperature measurement points.

[0074] The heating area of ​​the traditional single-turn rectangular cross-section pure copper induction coil basically covers eight points: 2, 3, 5, 6, 10, 11, 14, and 15. Therefore, the temperature at these eight positions rises fastest. The actual combustion heat inside the cylinder causes the cylinder head surface to heat up and extend from the nose bridge area to the surrounding area through heat conduction.

[0075] The cylinder head thermal fatigue test device in this embodiment is provided with a pancake-shaped heating test simulation device 20, the shape of which is designed to be adapted to the size of the test piece, and the cross section of the heating test simulation device 20 is trapezoidal, the lower surface protrusion of the heating test simulation device 20 is at the smallest distance from the test piece, the heating rate is the fastest, the power is the highest, and the hypotenuse of the lower surface of the heating test simulation device 20 is inclined upward, resulting in different height differences, forming heating differences, and thus forming temperature differences. Under the same current and time conditions, the heating surface of the entire heating test simulation device 20 can generate a temperature gradient on the test piece, the temperature of the nose bridge area of ​​the test piece is the highest, and the temperature decreases along the nose bridge area to the surrounding areas.

[0076] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0077] In addition to the above, it should be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present invention.

[0078] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A thermal fatigue testing device, characterized in that: include: A heating test simulation device (20), the heating test simulation device (20) having a heating working surface (21) and a bottom surface (22) arranged relative to each other in a thickness direction, the heating test simulation device (20) having a working position for performing a heating test simulation on a test object, the test object at least comprising a test cylinder head, when the heating test simulation device (20) is in the working position, the heating working surface (21) is arranged toward the test object, and along the extension direction of the heating working surface (21), the distance between the heating working surface (21) and the bottom surface (22) is arranged at different distances, so that during the test of the test object, a temperature gradient field is formed on the surface of the test object.

2. The thermal fatigue testing device according to claim 1, characterized in that: The heating test simulation device (20) is an induction heating device.

3. The thermal fatigue testing device according to claim 1 or 2, characterized in that: The heating test simulation device (20) is a disc-shaped structure.

4. The thermal fatigue testing device according to claim 3, characterized in that: The heating working surface (21) comprises a first working surface (211) and a second working surface (212) which are sequentially arranged radially outward from the heating working surface (21), wherein, along the radially outward direction of the heating working surface (21), the distance between the first working surface (211) and the bottom surface (22) is arranged to be constant, and the distance between the second working surface (212) and the bottom surface (22) is arranged to be gradually reduced.

5. The thermal fatigue testing device according to claim 4, characterized in that: When the heating test simulation device (20) is in the working position, along the thickness direction of the heating test simulation device (20), the projection of the first working surface (211) covers the nose bridge area of ​​the test cylinder head, wherein the nose bridge area is the area between two adjacent cylinder holes on the test cylinder head.

6. The thermal fatigue testing device according to any one of claims 1, 2, 4 and 5, characterized in that: The heating test simulation device (20) has a heating assembly, which includes a plurality of annular heating elements spaced apart and arranged radially outwardly along the heating working surface (21).

7. The thermal fatigue testing device according to claim 1, 2, 4, 5, characterized in that: The thermal fatigue testing device also includes: A cooling test simulation device is provided, wherein the cooling test simulation device has at least one air flow nozzle, and the air flow nozzle is used to spray cooling air flow to the test object to cool the test object.

8. The thermal fatigue testing device according to claim 1, 2, 4, 5, characterized in that: The thermal fatigue testing device also includes: A temperature detection device is used to detect the temperature of the test object.

9. A thermal fatigue test method, characterized in that: The method uses the thermal fatigue test device described in any one of claims 1 to 8 to perform the test, and the method comprises the following steps: Using the heating test simulation device (20) and the cooling test simulation device to perform a preset number of thermal cycle treatments on the test object, and obtaining test data of the test object, the test data at least including temperature data of the test object, duration data of the thermal cycle treatment, and surface physical change data of the test object; Based on the test data, the thermal fatigue performance of the test object is evaluated.

10. The thermal fatigue test method according to claim 9, characterized in that: The thermal cycle treatment comprises the following steps: placing the heating test simulation device (20) in a working position, and heating the test object using the heating test simulation device (20); When it is determined that the temperature of the test object meets the first temperature condition, the test object is cooled by using a cooling test simulation device until the temperature of the test object meets the second temperature condition.

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