Exhaust manifold thermal fatigue test equipment

Abstract

The present invention discloses an exhaust manifold thermal fatigue test device, comprising: a bracket, a base, at least one guide rail, a platform, a simulated cylinder head, an exhaust manifold, a first lifting mechanism, a second lifting mechanism, a heating coil, a plurality of infrared thermometers, a baffle and a cooling mechanism. The base is fixed to the bracket. At least one guide rail is mounted on the base. The platform can be slidably mounted on the guide rail. The simulated cylinder head is fixed to the platform. The exhaust manifold is mounted on the simulated cylinder head. The first lifting mechanism is fixed to the bracket. The second lifting mechanism is fixed to the bracket, and the second lifting mechanism is located behind the first lifting mechanism. The heating coil is mounted on the first lifting mechanism and is located above the exhaust manifold. Thus, the exhaust manifold thermal fatigue test device of the present invention can simulate the normal working state of the exhaust manifold, greatly reducing the verification time of the exhaust manifold thermal fatigue, with high verification efficiency and low test cost, which is conducive to rapid product improvement.

Description

Technical Field

[0001] The invention relates to the technical field of diesel engines, in particular to an exhaust manifold thermal fatigue test device. Background Art

[0002] The exhaust manifold is a crucial component of a diesel engine's exhaust system and serves as the primary channel for vehicle exhaust emissions. Its primary function is to discharge exhaust gases from the cylinders into the atmosphere with minimal exhaust resistance and noise. During operation, the exhaust manifold is not only subjected to the impact of high-temperature exhaust gases but also to the effects of engine vibration. This alternating load can easily cause the exhaust manifold to fail, thereby impacting the performance of the engine's exhaust system. Therefore, optimizing the design of an exhaust manifold with superior performance and a rational structure is crucial. However, the effectiveness of the improved exhaust manifold requires verification through bench testing or feedback from market users. This results in high verification costs and a long lead time, making it difficult to quickly and effectively reflect the optimization results of the exhaust manifold.

[0003] Current research primarily optimizes exhaust manifold design using finite element simulation, bench testing, and market research. Engineers at Toyota Motor Corporation in Japan used finite element analysis to predict the fatigue life of exhaust manifolds, but this method failed to fully reflect the fatigue life of the product in the real world. Ford Motor Company's Relyic calculated the transient thermal stresses of the exhaust manifold to analyze fatigue life, then used bench testing to obtain highly consistent results. However, bench testing is expensive. Li Wei and others at the FAW Group Corporation's Technical Center studied the changes in the metallographic structure of the exhaust manifold after heating, based on its material properties. They then analyzed customer market usage to determine the fatigue life limit of the exhaust manifold. However, the improvement verification process was long, hindering efficient improvement. Wang Lixin and others at the Pan Asia Technical Automotive Center conducted static load and modal analysis of the exhaust manifold, improving its performance through structural improvements, but this approach was not feasible for physical verification. In general, most companies at home and abroad verify the improvement effect of new exhaust manifolds through bench tests, market launches, or software simulations, which takes about half a year to a year. This results in high verification costs and low verification efficiency, which is not conducive to rapid product improvement.

[0004] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide an exhaust manifold thermal fatigue test device with a simple and reasonable structure, which can simulate the normal working state of the exhaust manifold, greatly reduce the verification time of the exhaust manifold thermal fatigue, have high verification efficiency, and low test cost, which is conducive to the rapid improvement of products.

[0006] To achieve the above objectives, the present invention provides exhaust manifold thermal fatigue testing equipment, comprising: a bracket, a base, at least one guide rail, a platform, a simulated cylinder head, an exhaust manifold, a first lifting mechanism, a second lifting mechanism, a heating coil, a plurality of infrared thermometers, a baffle, and a cooling mechanism. The base is fixed to the bracket. At least one guide rail is mounted on the base. The platform is slidably mounted on the guide rail. The simulated cylinder head is fixed to the platform. The exhaust manifold is mounted on the simulated cylinder head. The first lifting mechanism is fixed to the bracket. The second lifting mechanism is fixed to the bracket and located behind the first lifting mechanism. The heating coil is mounted on the first lifting mechanism and located above the exhaust manifold, and is used to heat the exhaust manifold. The plurality of infrared thermometers are respectively mounted on the first lifting mechanism and located above the heating coil, and are respectively used to measure the temperature of various regions of the exhaust manifold. The baffle is mounted on the second lifting mechanism. The cooling mechanism is installed on the bracket and is located behind the baffle, and the cooling mechanism is used for cooling the exhaust manifold.

[0007] In one embodiment of the present invention, the exhaust manifold thermal fatigue test equipment further includes a control cabinet and a temperature sensor. The control cabinet is disposed adjacent to the bracket. The temperature sensor is disposed within the cooling mechanism and is electrically connected to the control cabinet. The first lifting mechanism, the second lifting mechanism, the heating coil, the plurality of infrared thermometers, and the cooling mechanism are each electrically connected to the control cabinet.

[0008] In one embodiment of the present invention, the simulated cylinder head is provided with a gas passage and a cylinder head inner cavity cooling water circuit. When the exhaust manifold is installed on the simulated cylinder head, circulating water cooling can be achieved inside the simulated cylinder head, and the air passage inner cavity of the simulated cylinder head can realize the blowing function.

[0009] In one embodiment of the present invention, the cooling mechanism includes a housing, an air cooling module, and a mist cooling module. The housing has an opening at the front end for access to the platform, the simulated cylinder head, and the exhaust manifold. The air cooling module is disposed within the housing and is configured to blow ambient air into the interior of the exhaust manifold, thereby reducing the temperature of the exhaust manifold. Furthermore, the mist cooling module is disposed within the housing and is configured to spray water mist onto the exhaust manifold, thereby reducing the temperature of the exhaust manifold.

[0010] In one embodiment of the present invention, the number of the at least one guide rail is two, the two guide rails are respectively installed on the base, and there is a distance between the two guide rails.

[0011] In one embodiment of the present invention, the heating coil is semicircular, and when the first lifting mechanism drives the heating coil to move downward to the bottom, the heating coil can cover the exhaust manifold, thereby heating the exhaust manifold.

[0012] In one embodiment of the present invention, when the exhaust manifold reaches a preset heating temperature, the first lifting mechanism drives the heating coil to move upward, the second lifting mechanism drives the baffle to move upward, and the two guide rails drive the platform into the cooling mechanism. When the platform enters the cooling mechanism, the second lifting mechanism drives the baffle to move downward to the bottom, and the cooling mechanism performs a cooling operation on the exhaust manifold.

[0013] In one embodiment of the present invention, the exhaust manifold thermal fatigue testing equipment further includes at least one water tank fixed on the bracket and located behind the base.

[0014] Compared with the prior art, the exhaust manifold thermal fatigue test equipment according to the present invention has a simple and reasonable structure, can simulate the normal working state of the exhaust manifold, greatly reduces the verification time of the exhaust manifold thermal fatigue, has high verification efficiency, and low test cost, which is conducive to rapid product improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of the main structure of an exhaust manifold thermal fatigue test device according to one embodiment of the present invention;

[0016] Figure 2 1 is a schematic diagram of a three-dimensional structure of an exhaust manifold thermal fatigue test device according to an embodiment of the present invention;

[0017] Figure 3 is another schematic perspective structural diagram of an exhaust manifold thermal fatigue testing device according to one embodiment of the present invention;

[0018] Figure 4 is a schematic perspective view of a partial structure of an exhaust manifold thermal fatigue test device according to one embodiment of the present invention;

[0019] Figure 5 1 is a partial structural diagram of an exhaust manifold thermal fatigue testing device according to one embodiment of the present invention.

[0020] Description of main reference numerals:

[0021] 1- bracket, 2- base, 3- guide rail, 4- platform, 5- simulated cylinder head, 6- exhaust manifold, 7- first lifting mechanism, 8- second lifting mechanism, 9- heating coil, 10- infrared thermometer, 11- baffle, 12- cooling mechanism, 13- box, 14- air cooling module, 15- mist cooling module, 16- water tank. DETAILED DESCRIPTION

[0022] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0023] Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "include" or "comprising", etc., will be understood to include the stated elements or components but not to exclude other elements or other components.

[0024] Figure 1 1 is a schematic diagram of the front structure of an exhaust manifold thermal fatigue testing device according to one embodiment of the present invention. Figure 2 3D schematic diagram of an exhaust manifold thermal fatigue testing device according to an embodiment of the present invention. Figure 3 2 is another schematic perspective view of the exhaust manifold thermal fatigue testing equipment according to one embodiment of the present invention. Figure 4 It is a partial structural perspective diagram of an exhaust manifold thermal fatigue testing device according to one embodiment of the present invention. Figure 5 1 is a partial structural diagram of an exhaust manifold thermal fatigue testing device according to one embodiment of the present invention.

[0025] like Figures 1 to 5 As shown, an exhaust manifold thermal fatigue test equipment according to a preferred embodiment of the present invention includes: a bracket 1, a base 2, at least one guide rail 3, a platform 4, a simulated cylinder head 5, an exhaust manifold 6, a first lifting mechanism 7, a second lifting mechanism 8, a heating coil 9, a plurality of infrared thermometers 10, a baffle 11 and a cooling mechanism 12. The base 2 is fixed to the bracket 1. At least one guide rail 3 is mounted on the base 2. The platform 4 can be slidably mounted on the guide rail 3. The simulated cylinder head 5 is fixed on the platform 4. The exhaust manifold 6 is mounted on the simulated cylinder head 5. The first lifting mechanism 7 is fixed to the bracket 1. The second lifting mechanism 8 is fixed to the bracket 1, and the second lifting mechanism 8 is located behind the first lifting mechanism 7. The heating coil 9 is mounted on the first lifting mechanism 7 and is located above the exhaust manifold 6, and the heating coil 9 is used to heat the exhaust manifold 6. Multiple infrared thermometers 10 are mounted on the first lifting mechanism 7 and located above the heating coil 9. Each infrared thermometer 10 is used to measure the temperature of various areas of the exhaust manifold 6. A baffle 11 is mounted on the second lifting mechanism 8. A cooling mechanism 12 is mounted on the bracket 1 and located behind the baffle 11. The cooling mechanism 12 is used to cool the exhaust manifold 6.

[0026] In one embodiment of the present invention, the exhaust manifold thermal fatigue test equipment further includes a control cabinet and a temperature sensor. The control cabinet is located adjacent to the bracket 1. The temperature sensor is located within the cooling mechanism 12 and is electrically connected to the control cabinet. The first lifting mechanism 7, the second lifting mechanism 8, the heating coil 9, the plurality of infrared thermometers 10, and the cooling mechanism 12 are each electrically connected to the control cabinet.

[0027] In one embodiment of the present invention, the simulated cylinder head 5 is provided with a gas passage and a cylinder head inner cavity cooling water circuit. When the exhaust manifold 6 is installed on the simulated cylinder head 5, circulating water cooling can be achieved inside the simulated cylinder head 5, and the airway inner cavity of the simulated cylinder head 5 can realize the blowing function.

[0028] In one embodiment of the present invention, the cooling mechanism 12 comprises a housing 13, an air cooling module 14, and a mist cooling module 15. The housing 13 has an opening at the front end for access to the platform 4, the simulated cylinder head 5, and the exhaust manifold 6. The air cooling module 14 is disposed within the housing 13 and is used to blow ambient air into the interior of the exhaust manifold 6, thereby lowering the temperature of the exhaust manifold 6. The mist cooling module 15 is also disposed within the housing 13 and is used to spray water mist onto the exhaust manifold 6, thereby lowering its temperature.

[0029] In one embodiment of the present invention, the number of the at least one guide rail 3 is two, the two guide rails 3 are respectively installed on the base 2 , and there is a distance between the two guide rails 3 .

[0030] In one embodiment of the present invention, the heating coil 9 is semicircular, but the present invention is not limited thereto. The shape of the heating coil can be set according to the shape and temperature distribution of the product, and when the first lifting mechanism 7 drives the heating coil 9 to move downward to the bottom, the heating coil 9 can cover the exhaust manifold 6, thereby heating the exhaust manifold 6.

[0031] In one embodiment of the present invention, when the exhaust manifold 6 reaches a preset heating temperature, the first lifting mechanism 7 drives the heating coil 9 to move upward, the second lifting mechanism 8 drives the baffle 11 to move upward, and the two guide rails 3 drive the platform 4 to enter the cooling mechanism 12. When the platform 4 enters the cooling mechanism 12, the second lifting mechanism 8 drives the baffle 11 to move downward to the bottom, and the cooling mechanism 12 performs a cooling operation on the exhaust manifold 6.

[0032] In one embodiment of the present invention, the exhaust manifold thermal fatigue test equipment further includes at least one water tank 16 fixed on the bracket 1 and located behind the base 2 .

[0033] In practical applications, the exhaust manifold thermal fatigue test equipment of the present invention comprises a bracket 1, which serves as the support for the entire test setup. Two guide rails 3 (rodless cylinders) are mounted on bracket 1, allowing a platform 4 to slide along the guide rails 3 and adjust the exhaust manifold 6 for testing at different test positions. Platform 4 is used to mount and secure a simulated cylinder head 5, simulating its installation on an engine. Platform 4 slides along the guide rails 3, moving the simulated cylinder head 5 and exhaust manifold 6 between different test positions. The simulated cylinder head 5, primarily serving to simulate the engine environment, is fixed to platform 4 and connected to the test piece, exhaust manifold 6. A heating coil 9 utilizes a high-frequency coil to heat the exhaust manifold 6. However, the coil structure must be adjusted based on the exhaust manifold 6's temperature field to ensure that the test temperature field of the exhaust manifold 6 closely matches the actual engine operating temperature field. Multiple infrared thermometers 10 are mounted above the heating coils 9 to measure the test temperature at the same location on the same exhaust manifold 6, serving as a means of monitoring the test temperature field's proximity to the actual engine operating temperature field. The temperature of the entire exhaust manifold 6 test is simultaneously controlled. Once the maximum test temperature is reached, the heating coil 9 automatically shuts off, stopping heating and allowing the next test step to proceed. The first lifting mechanism 7 controls the height of the heating coil 9. When the exhaust manifold 6 requires heating, the heating coil 9 descends and covers the exhaust manifold 6 for induction heating. When the exhaust manifold 6 reaches the test temperature, heating ceases, the heating coil 9 is raised, and the exhaust manifold 6, along with the platform 4, slides to the next test station. The second lifting mechanism 8 controls the baffle 11. When the exhaust manifold 6 and platform 4 are about to proceed to the cooling station, the baffle 11 rises as the second lifting mechanism 8 pulls up, allowing the exhaust manifold 6 and platform 4 to proceed to the cooling station. Before the exhaust manifold 6 begins cooling, the baffle 11 descends, allowing the exhaust manifold 6 and platform 4 to cool in the cooling station. This mist cooling process does not affect the heating coil 9 and also prevents water mist from spreading and affecting the environment. The baffle 11 primarily separates the heating and cooling zones, preventing them from interfering with each other. The cooling mechanism 12 is provided with an air cooling module 14 and a mist cooling module 15 in a closed space. The air cooling module 14 is mainly used to blow room temperature air into the inner cavity of the exhaust manifold 6 to reduce the temperature of the exhaust manifold 6; when the temperature of the exhaust manifold 6 drops to 300°C and no material structure changes occur, in order to speed up the cooling speed, the mist cooling module 15 is used until the exhaust manifold 6 cools to about 150°C. The exhaust manifold 6 is installed on the cylinder head of the simulated engine as a test piece for testing, and the water tank 16 is mainly filled with circulating water for zero cooling (which can also be provided to the mist cooling module 15). Among them, the first lifting mechanism 7 and the second lifting mechanism 8 can both be composed of a guide rail 3 and a sliding rod, but the present invention is not limited to this. Any lifting structure that can drive the heating coil 9 and the baffle 11 can be used.

[0034] Specifically, the guide rail 3 is installed on the bracket 1, and the platform 4 is installed on the guide rail 3, which is used to move the platform 4. The platform 4 can move back and forth between the heating zone and the cooling zone to realize cyclic hot and cold fatigue testing. The simulated cylinder head 5 is connected to the exhaust manifold 6 to be tested and is installed on the platform 4. The heating coil 9 is above the exhaust manifold to be tested, connected to the first lifting mechanism 7 and fixed on the bracket 1, and is used to heat the exhaust manifold to be tested. A plurality of infrared thermometers 10 are fixed on the bracket 1 to measure the temperature of each area of ​​the exhaust manifold. The cooling mechanism 12 has two modes: air cooling and mist cooling, which are mainly used to realize the cold shock test of the exhaust manifold. The second lifting mechanism 8 is connected above the baffle 11 and fixed on the bracket 1, which is mainly used to separate the heating zone and the cooling zone to prevent water mist from spraying onto the heating coil 9 and effectively control the range of atomization to avoid excessive influence.

[0035] The simulated cylinder head 5 is provided with a gas passage and a cylinder head inner cavity cooling water circuit, which is compatible with the exhaust manifold 6 to be tested. When the exhaust manifold 6 to be tested and the simulated cylinder head 5 are assembled according to the normal engine installation process, circulating water cooling can be achieved inside the cylinder head to simulate the water cooling method of the cylinder head 5, while the inner cavity of the cylinder head airway realizes the blowing function.

[0036] During field use, the control cabinet (control system) should first be set to manual control. The exhaust manifold test parameters should be manually set to meet the required operating conditions, such as test temperature, test alarm temperature, exhaust manifold air cooling time, zero cooling time, and number of test cycles. The positions of the exhaust manifold (6) to be tested and the simulated cylinder head (5) should then be manually adjusted. The assembled cylinder head and exhaust manifold assembly should be returned to the control system's origin. At this point, the control system should be set to automatic control and activated. The simulated cylinder head and exhaust manifold should be brought to the heating station according to the control program instructions. Upon receiving the test instructions, the controller generates control commands, controlling the heating system to thermally shock the exhaust manifold (6) to be tested.

[0037] When the main control temperature reaches the set thermal shock temperature, the heating system receives a command to stop heating and simultaneously generates another cooling command. After the exhaust manifold 6 is heated, it follows the set cooling path to the cooling station. The controller controls the cooling system through a program to cool the exhaust manifold 6 under test with air or water mist, respectively. The air cooling time or mist cooling time is adjusted according to the actual temperature of the exhaust manifold on the engine. This process is repeated until the exhaust manifold 6 reaches its thermal fatigue limit.

[0038] Multiple infrared thermometers 10 are located above the heated area of ​​the exhaust manifold 6 under test and connected to the controller. These thermometers are used to transmit temperature changes in the exhaust manifold 6 during the test to the controller, monitor the temperature distribution of the heated exhaust manifold, and provide a basis for adjusting the exhaust manifold temperature field.

[0039] In summary, the exhaust manifold thermal fatigue test equipment of the present invention has a simple and reasonable structure, can simulate the normal working state of the exhaust manifold 6, greatly reduces the verification time of the exhaust manifold 6 thermal fatigue, has high verification efficiency, and low test cost, which is conducive to rapid product improvement.

[0040] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. An exhaust manifold thermal fatigue test equipment, characterized in that: include: Bracket; a base, fixed on the bracket; at least one guide rail mounted on the base; a platform slidably mounted on the guide rail; a simulated cylinder head fixed on the platform; an exhaust manifold mounted on the simulated cylinder head; A first lifting mechanism is fixed on the bracket; a second lifting mechanism, fixed on the bracket, and located behind the first lifting mechanism; a heating coil, mounted on the first lifting mechanism and located above the exhaust manifold, and configured to heat the exhaust manifold; a plurality of infrared thermometers, each mounted on the first lifting mechanism and located above the heating coil, and each of the plurality of infrared thermometers is used to measure the temperature of each area of ​​the exhaust manifold; a baffle, mounted on the second lifting mechanism; a cooling mechanism, mounted on the bracket and located behind the baffle, and configured to cool the exhaust manifold; A control cabinet is arranged beside the bracket; as well as a temperature sensor disposed in the cooling mechanism and electrically connected to the control cabinet; wherein the simulated cylinder head is provided with a gas passage and a cylinder head inner cavity cooling water circuit, and when the exhaust manifold is installed on the simulated cylinder head, circulating water cooling can be achieved inside the simulated cylinder head, and the gas passage of the simulated cylinder head can achieve an air blowing function; Wherein, the first lifting mechanism, the second lifting mechanism, the heating coil, the plurality of infrared thermometers and the cooling mechanism are electrically connected to the control cabinet respectively; Wherein, the cooling mechanism comprises: a box body, wherein the front end of the box body has an opening for allowing the platform, the simulated cylinder head and the exhaust manifold to enter; an air cooling module disposed in the box body and configured to blow room temperature air into the inner cavity of the exhaust manifold, thereby reducing the temperature of the exhaust manifold; a mist cooling module, disposed in the box, and configured to spray water mist onto the exhaust manifold, thereby reducing the temperature of the exhaust manifold; Wherein, the cooling mechanism switches the mist cooling module after the temperature drops to 300°C.

2. The exhaust manifold thermal fatigue test equipment according to claim 1, characterized in that: The number of the at least one guide rail is two, the two guide rails are respectively installed on the base, and there is a distance between the two guide rails.

3. The exhaust manifold thermal fatigue testing equipment according to claim 2, characterized in that: The heating coil is semicircular, and when the first lifting mechanism drives the heating coil to move downward to the bottom, the heating coil can cover the exhaust manifold, thereby heating the exhaust manifold.

4. The exhaust manifold thermal fatigue testing equipment according to claim 3, characterized in that: When the exhaust manifold reaches a preset heating temperature, the first lifting mechanism drives the heating coil to move upward, the second lifting mechanism drives the baffle to move upward, and the two guide rails drive the platform to enter the cooling mechanism. When the platform enters the cooling mechanism, the second lifting mechanism drives the baffle to move downward to the bottom, and the cooling mechanism performs a cooling operation on the exhaust manifold.

5. The exhaust manifold thermal fatigue testing equipment according to claim 1, wherein: It also includes at least one water tank which is fixed on the bracket and located behind the base.

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