Intelligent production system based on engine cylinder head thermal fatigue detection

Abstract

The application relates to the technical field of cylinder head production, in particular to an intelligent production system based on engine cylinder head thermal fatigue detection, which comprises a production module, a thermal fatigue simulation module used for heating the cylinder head, a detection module used for detecting the thermal fatigue degree of the cylinder head, a control module, wherein the detection module comprises an ultrasonic assembly and a temperature measuring assembly used for detecting the air temperature around the cylinder head and the inner and outer wall temperatures of the cylinder head; the control module is used for determining the adjustment mode of ultrasonic detection according to the temperature difference between the inner and outer wall temperatures of the cylinder head, including adjusting the signal-to-noise ratio of the ultrasonic assembly, or adjusting the height of the ultrasonic signal according to the electroacoustic efficiency of the ultrasonic signal, or determining the distance between the ultrasonic assembly and the cylinder head according to the deviation amount of the echo signal, and adjusting the alternate detection frequency of the ultrasonic assembly according to the cooling rate of the cylinder head. The application improves the accuracy and stability of detection.

Description

Technical Field

[0001] This invention relates to the field of cylinder head manufacturing technology, and in particular to an intelligent manufacturing system based on engine cylinder head thermal fatigue detection. Background Technology

[0002] In existing technology, the cylinder head is a part of the engine, mounted on top of the cylinder block. It seals the cylinder from above and forms the combustion chamber. The cylinder head is frequently in contact with high-temperature, high-pressure combustion gases, thus bearing significant thermal and mechanical loads. Thermal fatigue testing of the cylinder head is based on the fatigue damage caused by the generation and release of thermal stress during repeated temperature cycles. In the engine cylinder head, this thermal stress is mainly caused by the temperature difference between the inner and outer surfaces. When the cylinder head is heated, compressive stress is generated inside, while tensile stress is generated outside; the opposite occurs during cooling. This repeated temperature cycling and stress variation ultimately leads to fatigue damage and crack formation in the cylinder head material. Through thermal fatigue testing, the fatigue life of the cylinder head material under specific temperature cycling conditions can be evaluated, the crack formation and propagation mechanisms can be revealed, and the improvement and optimization of the cylinder head structure can be guided.

[0003] Chinese Patent Publication No. CN111521565B discloses a crack opening width detection system and method based on laser ultrasound. The system includes a sample (4) with a crack to be tested, an ultrasonic excitation device (1), a heating device (2), an ultrasonic detection device (3), a signal acquisition device (5), a motion device (6), and a control device (7). The ultrasonic excitation device (1) is used as an ultrasonic signal excitation source for the sample (4) with the crack to be tested. The heating device (2) is used to heat the crack to be tested on the sample (4) to generate thermal stress to close the crack. The ultrasonic detection device (3) is used to receive ultrasonic signals. The signal acquisition device (5) is used to acquire... The ultrasonic signal is transmitted to the control device (7); the motion device (6) is used to drive the heating point of the heating device (2) on the crack to be tested to move synchronously with the crack to be tested; the control device (7) is used to adjust the heating power of the heating device (2) and control the movement of the motion device (6), and is also used to determine the opening width of the crack to be tested on the sample (4) according to the correspondence between the displacement generated by the crack closure and the heating power; the excitation point of the ultrasonic excitation device (1) irradiating the surface of the sample (4), the heating point of the heating device (2) irradiating the crack to be tested, and the detection point of the ultrasonic detection device (3) for ultrasonic detection are located on the same straight line, and the straight line is perpendicular to the direction of the crack to be tested. Therefore, it can be seen that the above-mentioned laser-ultrasound-based crack opening width detection system and method have problems such as the change in sound wave propagation speed due to high temperature during thermal fatigue detection, which leads to a decrease in detection accuracy; and the presence of temperature gradients in the detection environment causing sound waves to encounter air layers of different temperatures during propagation, thereby changing their propagation speed and direction, and even causing attenuation of sound wave intensity and phase distortion. Summary of the Invention

[0004] To address this, the present invention provides an intelligent production system based on engine cylinder head thermal fatigue detection, which overcomes the problems in the prior art where ultrasonic testing encounters high-temperature gas during thermal fatigue detection, causing changes in the propagation speed of sound waves and thus reducing the accuracy of the detection. Furthermore, the presence of temperature gradients in the testing environment causes sound waves to encounter air layers of different temperatures during propagation, thereby altering their propagation speed and direction, and even causing attenuation of sound wave intensity and phase distortion.

[0005] To achieve the above objectives, the present invention provides an intelligent production system based on engine cylinder head thermal fatigue detection, including a housing, and further comprising:

[0006] The production module is used to output the cylinder head;

[0007] A thermal fatigue simulation module is located at the bottom of the box and simulates the thermal fatigue process of the cylinder head by heating the cylinder head output by the production module.

[0008] The detection module, which is connected to the thermal fatigue simulation module, is used to detect the degree of thermal fatigue of the cylinder head. It includes an ultrasonic component that performs ultrasonic testing on the cylinder head to determine whether the cylinder head has cracks, and a temperature measuring component connected to the cylinder head to detect the air temperature around the cylinder head and the temperature parameters of the cylinder head.

[0009] A control module, connected to both the thermal fatigue simulation module and the detection module, is used to determine the adjustment method for ultrasonic testing based on the temperature difference between the inner and outer walls of the cylinder head, including adjusting the signal-to-noise ratio of the ultrasonic components.

[0010] Alternatively, the height of the ultrasonic signal can be adjusted based on its electroacoustic efficiency.

[0011] Alternatively, the distance between the ultrasonic component and the cylinder head can be determined based on the deviation of the echo signal, and the alternating detection frequency of the ultrasonic component can be adjusted according to the cooling rate of the cylinder head.

[0012] Furthermore, the ultrasound component includes:

[0013] A first ultrasonic transmitter is located inside the housing;

[0014] The second ultrasonic transmitter is arranged in parallel behind the first ultrasonic transmitter.

[0015] The first slider telescopic rod is connected to the first ultrasonic transmitter and is used to adjust the distance between the first ultrasonic transmitter and the cylinder head and the height between the first ultrasonic transmitter and the lower surface of the housing.

[0016] The second slider telescopic rod is connected to the second ultrasonic transmitter and is used to adjust the distance between the second ultrasonic transmitter and the cylinder head and the height between the second ultrasonic transmitter and the lower surface of the housing;

[0017] The heights of the first and second ultrasonic transmitters are equal to the height of the cylinder head.

[0018] Furthermore, the temperature measuring component includes:

[0019] A first temperature sensor is disposed on the inner wall of the cylinder head to detect the temperature of the inner wall of the cylinder head.

[0020] The second temperature sensor is disposed on the outer wall of the cylinder head to detect the temperature of the outer wall of the cylinder head;

[0021] An infrared thermal imaging thermometer is positioned above the second temperature sensor to detect the air temperature between the first and second ultrasonic transmitters and the cylinder head, respectively.

[0022] Furthermore, the control module is connected to both the temperature measuring component and the ultrasonic component to obtain the rate of change of the temperature difference between the inner and outer walls of the cylinder head during the first detection stage.

[0023] If the rate of change of the temperature difference is greater than the preset second rate of change, it is determined that the accuracy of the ultrasonic detection does not meet the requirements, and the signal-to-noise ratio of the first ultrasonic transmitter and the second ultrasonic transmitter are reduced respectively.

[0024] Furthermore, the signal-to-noise ratio is negatively correlated with the rate of change of the temperature difference; the rate of change of the temperature difference is the ratio of the difference between the inner wall temperature and the outer wall temperature of the cylinder head to the unit detection time of the thermal fatigue simulation operation cycle.

[0025] Furthermore, the control module is connected to the ultrasonic component and is used to preliminarily determine that the stability of the signal transmission does not meet the requirements when the rate of change of the temperature difference is greater than a preset first rate of change and less than or equal to a preset second rate of change, and to obtain the electroacoustic efficiency of the ultrasonic signal of the ultrasonic component, wherein,

[0026] If the electroacoustic efficiency is less than a preset first electroacoustic efficiency, the stability of the signal transmission is determined to be unsatisfactory, and the heights of the first and second ultrasonic transmitters are increased respectively.

[0027] The height is negatively correlated with the electroacoustic efficiency.

[0028] Furthermore, the control module is connected to both the ultrasonic component and the infrared thermal imaging thermometer, and is used to preliminarily determine that the transmission stability of the ultrasonic signal does not meet the requirements when the electroacoustic efficiency is greater than or equal to the preset first electroacoustic efficiency and less than the preset second electroacoustic efficiency, and to calculate the deviation between the echo signals of the first ultrasonic transmitter and the second ultrasonic transmitter.

[0029] If the deviation is greater than the preset deviation, the transmission stability of the ultrasonic signal is determined to be unsatisfactory, and the distances between the first ultrasonic transmitter and the second ultrasonic transmitter and the cylinder head are reduced to positions that meet the detection temperature conditions.

[0030] Furthermore, the deviation of the echo signal is the absolute value of the difference between the peak sound pressure of the echo signal of the first ultrasonic transmitter after the heating of the thermal fatigue simulation module has stopped and the echo signal of the second ultrasonic transmitter after the heating of the thermal fatigue simulation module has stopped.

[0031] The temperature detection condition is the end position of the unit length when the air temperature difference is at its maximum value among several unit lengths of air temperature difference between the first ultrasonic transmitter and the second ultrasonic transmitter and the cylinder head, respectively.

[0032] The air temperature difference per unit length is the difference between the air temperature at the end of the unit length and the air temperature at the beginning of the unit length.

[0033] Furthermore, the control module is connected to the temperature measuring component to obtain the cooling rate of the inner wall of the cylinder head after the thermal fatigue simulation module stops heating. If the cooling rate is greater than the preset cooling rate, it is determined that the stability of the echo signal does not meet the requirements, and the alternating detection frequency of the first ultrasonic transmitter and the second ultrasonic transmitter is increased.

[0034] Furthermore, the alternating detection frequency is the number of times the first ultrasonic transmitter and the second ultrasonic transmitter alternately detect each other within a unit detection time; the alternating detection frequency is positively correlated with the cooling rate.

[0035] Compared with existing technologies, the beneficial effects of this invention are as follows: The system of this invention, by setting up a thermal fatigue simulation module, a detection module, and a control module, analyzes the different effects of heating, maintaining a constant temperature, and cooling the cylinder head during thermal fatigue testing on ultrasonic detection. This is achieved by analyzing the detection state and adjusting the detection parameters of the ultrasonic transmitter in real time, ensuring the accuracy and stability of ultrasonic detection during cylinder head thermal fatigue testing. Furthermore, during the rapid heating of the cylinder head, the large temperature difference between the inside and outside of the cylinder head leads to a decrease in the propagation speed of ultrasonic waves in the medium. Adjusting the signal-to-noise ratio of the ultrasonic components reduces the impact of excessive temperature difference on the accuracy of ultrasonic detection. After the head temperature stabilizes, the cylinder head transfers heat to other areas within the chamber, creating a temperature difference within the testing space. This temperature difference affects the propagation speed and direction of sound waves, and can even cause attenuation of sound wave intensity and phase distortion. Furthermore, the high temperature difference increases testing errors. Adjusting the distance between the ultrasonic component and the cylinder head reduces the changes in sound wave propagation direction and intensity attenuation caused by the temperature difference, thus minimizing the resulting error. During high-temperature thermal fatigue testing, stress changes may cause a decrease in the stability of the ultrasonic signal echo, and the deviation of the ultrasonic echo signal gradually decreases. Adjusting the alternating detection frequency reduces noise interference, thereby improving the accuracy and stability of thermal fatigue testing.

[0036] Furthermore, the system of the present invention, by setting up a first ultrasonic transmitter, a second ultrasonic transmitter, a first sliding telescopic rod, and a second sliding telescopic rod, can achieve comprehensive detection of different positions of the cylinder head, ensuring the accuracy and reliability of the detection. The first and second ultrasonic transmitters can detect whether there are cracks inside the cylinder head by emitting ultrasonic waves, thereby assessing the thermal fatigue degree of the cylinder head. The first and second sliding telescopic rods can adjust the distance and height between the ultrasonic transmitter and the cylinder head to adapt to different cylinder head sizes and shapes, thereby improving the flexibility and applicability of the detection.

[0037] Furthermore, the system described in this invention, by setting up a first temperature sensor, a second temperature sensor, and an infrared thermal imaging thermometer, can monitor the inner and outer wall temperatures of the cylinder head and the air temperature between the ultrasonic transmitter and the cylinder head in real time, thereby obtaining temperature change information during the cylinder head thermal fatigue detection process. The first temperature sensor is set on the inner wall of the cylinder head to accurately measure the temperature of the inner wall of the cylinder head, reflecting the internal state of the cylinder head. The second temperature sensor is set on the outer wall of the cylinder head to measure the temperature of the outer wall of the cylinder head, and compares it with the inner wall temperature to help analyze the thermal stress distribution of the cylinder head. The infrared thermal imaging thermometer uses infrared thermal imaging technology to non-contactly measure the air temperature between the ultrasonic transmitter and the cylinder head, providing an environmental temperature reference for ultrasonic testing, helping to determine the working environment of ultrasonic testing, and improving the accuracy of ultrasonic testing.

[0038] Furthermore, the system of the present invention sets a preset second rate of change. When the rate of change is large, it indicates that the heating rate inside the cavity of the cylinder head is increasing. During the propagation of the ultrasonic signal, it may be affected by factors such as the thermal expansion of the cylinder head material. At this time, the temperature change inside the cylinder head is drastic, which leads to the stress change of the cylinder head. The speed of ultrasonic waves during propagation is affected by temperature, so by reducing the signal-to-noise ratio of the ultrasonic transmitter, the false detection rate can be reduced, and the accuracy of the detection results can be improved.

[0039] Furthermore, the system of the present invention sets a preset first electroacoustic efficiency and a preset second electroacoustic efficiency. The temperature inside the chamber rises through heat conduction from the cylinder head. When the temperature rises, the resistance of the transmission line of the ultrasonic transmitter increases, and the electroacoustic efficiency of the ultrasonic signal decreases. If the electroacoustic efficiency is lower than the preset first electroacoustic efficiency, it indicates that the stability of signal transmission may be affected. Therefore, by increasing the height of the ultrasonic transmitter, i.e. reducing the bends in the transmission line, the resistance of the line is reduced, thereby improving the electroacoustic efficiency of the ultrasonic signal and improving the stability of signal transmission.

[0040] Furthermore, the system of the present invention sets a deviation amount. Due to the temperature rise and fall during the thermal fatigue detection process, the ultrasonic device may deviate. By cross-verifying the detection results of the two ultrasonic transmitters, it can be determined whether the transmitter has suffered fatigue damage due to frequent temperature rises and falls in the environment. When the deviation amount exceeds the normal range, it indicates that the detection results of the ultrasonic transmitter may have a large error. Since the cylinder head dissipates heat to the surrounding environment, a certain temperature gradient will be generated in the detection space. Under the influence of the temperature gradient, the error range will increase. By reducing the distance between the ultrasonic transmitter and the cylinder head, the influence of the air temperature difference on the sound wave propagation is reduced, thereby improving the accuracy of ultrasonic detection.

[0041] Furthermore, the system of the present invention, by setting a cooling rate, addresses the issue that the ultrasonic propagation rate decreases after the cylinder head dissipates heat from the air and is then connected to cooling, leading to stress release in the cylinder head. During the cooling process of the cylinder head, the shrinkage of the cylinder head material may cause cracks to form or propagate. At this time, the control module increases the alternating detection frequency of the ultrasonic transmitter to more accurately capture the dynamic changes of the cracks. If the cooling rate is too high, it may cause a decrease in the stability of the ultrasonic signal echo. By increasing the alternating detection frequency, i.e., increasing the detection frequency of the ultrasonic transmitter, the signal-to-noise ratio of the ultrasonic signal is improved, thereby improving the accuracy and stability of thermal fatigue detection. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the intelligent production system based on engine cylinder head thermal fatigue detection according to an embodiment of the present invention;

[0043] Figure 2 This is a top view schematic diagram of the intelligent production system based on engine cylinder head thermal fatigue detection according to an embodiment of the present invention;

[0044] Figure 3 This is a structural block diagram of an intelligent production system based on engine cylinder head thermal fatigue detection, according to an embodiment of the present invention.

[0045] Figure 4 This is a structural block diagram of the temperature measurement component of the intelligent production system based on engine cylinder head thermal fatigue detection according to an embodiment of the present invention;

[0046] Explanation of reference numerals: 1-Box body, 2-First ultrasonic transmitter, 3-First sliding telescopic rod, 4-First slide rail, 5-Lifting rod, 6-High frequency induction heater, 7-Second temperature sensor, 8-Cylinder head, 9-Infrared thermal imaging thermometer, 10-Second ultrasonic transmitter, 11-Second slide rail. Detailed Implementation

[0047] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0048] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0049] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0050] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] Please see Figure 1 , Figure 2 , Figure 3 as well as Figure 4 The figures shown are, respectively, a structural schematic diagram of the intelligent production system based on engine cylinder head thermal fatigue detection according to an embodiment of the present invention; a top view of the structure; a structural block diagram; and a structural block diagram of the temperature measurement component. An embodiment of the present invention provides an intelligent production system based on engine cylinder head thermal fatigue detection, including a housing, and further comprising:

[0052] The production module is used to output the cylinder head;

[0053] A thermal fatigue simulation module is located at the bottom of the box and simulates the thermal fatigue process of the cylinder head by heating the cylinder head output by the production module.

[0054] The detection module, which is connected to the thermal fatigue simulation module, is used to detect the degree of thermal fatigue of the cylinder head. It includes an ultrasonic component that performs ultrasonic testing on the cylinder head to determine whether the cylinder head has cracks, and a temperature measuring component connected to the cylinder head to detect the air temperature around the cylinder head and the temperature parameters of the cylinder head.

[0055] A control module, connected to both the thermal fatigue simulation module and the detection module, is used to determine the adjustment method for ultrasonic testing based on the temperature difference between the inner and outer walls of the cylinder head, including adjusting the signal-to-noise ratio of the ultrasonic components.

[0056] Alternatively, the height of the ultrasonic signal can be adjusted based on its electroacoustic efficiency.

[0057] Alternatively, the distance between the ultrasonic component and the cylinder head can be determined based on the deviation of the echo signal, and the alternating detection frequency of the ultrasonic component can be adjusted according to the cooling rate of the cylinder head.

[0058] Specifically, the thermal fatigue simulation module includes:

[0059] A high-frequency induction heater that heats the cylinder head by generating eddy currents;

[0060] The lifting rod is connected to the high-frequency induction heater and is used to adjust the height of the high-frequency induction heater;

[0061] The lifting motor is connected to the lifting rod and is used to provide driving force for the lifting rod.

[0062] Specifically, the cylinder head is fitted outside the coil of the high-frequency induction heater.

[0063] Specifically, the detection module is used to determine whether the degree of thermal fatigue meets the requirements based on whether cracks have occurred in the cylinder head. If cracks have occurred, the requirements are not met.

[0064] In practice, the beneficial effects of this invention are as follows: The system, by setting up a thermal fatigue simulation module, a detection module, and a control module, analyzes the different effects of heating, maintaining a constant temperature, and cooling the cylinder head during thermal fatigue testing on ultrasonic detection. This is achieved by analyzing the detection status and adjusting the detection parameters of the ultrasonic transmitter in real time, ensuring the accuracy and stability of ultrasonic detection during cylinder head thermal fatigue testing. Furthermore, during cylinder head heating, the rapid heating rate leads to excessive temperature differences between the inside and outside of the cylinder head, affecting the propagation speed of ultrasonic waves in the medium. Adjusting the signal-to-noise ratio of the ultrasonic components reduces the impact of excessive temperature differences on the accuracy of ultrasonic detection. In the cylinder head… After the temperature stabilizes, the cylinder head transfers heat to other areas inside the chamber, causing a temperature difference within the testing space. This temperature difference affects the propagation speed and direction of sound waves, and even causes attenuation of sound wave intensity and phase distortion. The high temperature difference also increases the testing error. By adjusting the distance between the ultrasonic component and the cylinder head, the changes in the direction of sound wave propagation and the attenuation of intensity caused by the temperature difference can be reduced, thus reducing the increase in error. During high-temperature thermal fatigue testing, stress changes may cause a decrease in the stability of the ultrasonic signal echo, and the deviation of the ultrasonic echo signal will gradually decrease. By adjusting the alternating detection frequency, noise interference can be reduced, thereby improving the accuracy and stability of thermal fatigue testing.

[0065] Specifically, the ultrasound component includes:

[0066] A first ultrasonic transmitter is located inside the housing;

[0067] The second ultrasonic transmitter is arranged in parallel behind the first ultrasonic transmitter.

[0068] The first slider telescopic rod is connected to the first ultrasonic transmitter and is used to adjust the distance between the first ultrasonic transmitter and the cylinder head and the height between the first ultrasonic transmitter and the lower surface of the housing.

[0069] The second slider telescopic rod is connected to the second ultrasonic transmitter and is used to adjust the distance between the second ultrasonic transmitter and the cylinder head and the height between the second ultrasonic transmitter and the lower surface of the housing;

[0070] The heights of the first and second ultrasonic transmitters are equal to the height of the cylinder head.

[0071] Specifically, the heights of the first slider telescopic rod and the second slider telescopic rod are adjusted by the first telescopic motor and the second telescopic motor connected to them, respectively.

[0072] Specifically, the ultrasound component also includes:

[0073] The first slide rail is connected to the first slider telescopic rod and is used to limit the horizontal translation position of the first ultrasonic transmitter.

[0074] The second slide rail, which is connected to the second slider telescopic rod, is used to limit the horizontal translation position of the second ultrasonic transmitter;

[0075] The first moving motor is connected to the first slide rail and is used to provide driving force for the first slider telescopic rod to translate on the first slide rail.

[0076] The second moving motor is connected to the second slide rail and is used to provide driving force for the second slider telescopic rod to translate on the second slide rail.

[0077] The first ultrasonic receiver is installed on the inner wall of the housing to receive ultrasonic signals emitted by the first ultrasonic transmitter.

[0078] The second ultrasonic receiver is installed on the inner wall of the housing to receive ultrasonic signals emitted by the second ultrasonic transmitter.

[0079] Specifically, the first and second ultrasonic receivers calculate whether a crack has occurred based on the change in ultrasonic velocity and the return time.

[0080] Specifically, the lifting motor, the first telescopic motor, and the second telescopic motor are in a linked state.

[0081] Specifically, the detection method of the first ultrasonic transmitter and the second ultrasonic transmitter is to conduct continuous alternating detection.

[0082] In practice, the system of the present invention, by setting up a first ultrasonic transmitter, a second ultrasonic transmitter, a first sliding telescopic rod, and a second sliding telescopic rod, can achieve comprehensive detection of different positions of the cylinder head, ensuring the accuracy and reliability of the detection. The first and second ultrasonic transmitters can detect whether there are cracks inside the cylinder head by emitting ultrasonic waves, thereby assessing the thermal fatigue degree of the cylinder head. The first and second sliding telescopic rods can adjust the distance and height between the ultrasonic transmitter and the cylinder head to adapt to different cylinder head sizes and shapes, thereby improving the flexibility and applicability of the detection.

[0083] Specifically, the temperature measuring component includes:

[0084] A first temperature sensor is disposed on the inner wall of the cylinder head to detect the temperature of the inner wall of the cylinder head.

[0085] A second temperature sensor is disposed on the outer wall of the cylinder head to detect the temperature of the outer wall of the cylinder head;

[0086] An infrared thermal imaging thermometer is positioned above the second temperature sensor to detect the air temperature between the first and second ultrasonic transmitters and the cylinder head, respectively.

[0087] Specifically, the first temperature sensor and the second temperature sensor are contact temperature sensors.

[0088] In implementation, the system of this invention, by setting up a first temperature sensor, a second temperature sensor, and an infrared thermal imaging thermometer, can monitor the inner and outer wall temperatures of the cylinder head and the air temperature between the ultrasonic transmitter and the cylinder head in real time, thereby obtaining temperature change information during the cylinder head thermal fatigue detection process. The first temperature sensor is set on the inner wall of the cylinder head to accurately measure the temperature of the inner wall of the cylinder head, reflecting the internal state of the cylinder head. The second temperature sensor is set on the outer wall of the cylinder head to measure the temperature of the outer wall of the cylinder head, and compares it with the inner wall temperature to help analyze the thermal stress distribution of the cylinder head. The infrared thermal imaging thermometer uses infrared thermal imaging technology to non-contactly measure the air temperature between the ultrasonic transmitter and the cylinder head, providing an environmental temperature reference for ultrasonic testing, helping to determine the working environment of ultrasonic testing, and improving the accuracy of ultrasonic testing.

[0089] Specifically, the control module is connected to both the temperature measuring component and the ultrasonic component to obtain the rate of change of the temperature difference between the inner and outer walls of the cylinder head during the first detection phase.

[0090] If the rate of change of the temperature difference is greater than the preset second rate of change, it is determined that the accuracy of the ultrasonic detection does not meet the requirements, and the signal-to-noise ratio of the first ultrasonic transmitter and the second ultrasonic transmitter are reduced respectively.

[0091] Specifically, the maximum heating temperature of the cylinder head by the thermal fatigue simulation module is the operating temperature after the engine starts. When the cylinder head used for testing is the cylinder head of a small car engine, the preset temperature generally ranges from [450℃ to 750℃], with a preferred embodiment being 600℃.

[0092] Specifically, the signal-to-noise ratio is negatively correlated with the rate of change of the temperature difference; the rate of change of the temperature difference is the ratio of the difference between the inner wall temperature and the outer wall temperature of the cylinder head to the unit detection time of the thermal fatigue simulation operation cycle.

[0093] Specifically, the preset first rate of change generally ranges from [18℃ / min, 24℃ / min], and a preferred embodiment of the preset first rate of change is 20℃ / min; the preset second rate of change generally ranges from [26℃ / min, 35℃ / min], and a preferred embodiment of the preset second rate of change is 30℃ / min.

[0094] In practice, when the difference between the rate of change of temperature difference and the preset second rate of change is within 1℃ / min, the signal-to-noise ratio decreases by 0.01dB. When the difference between the rate of change of temperature difference and the preset second rate of change exceeds 1℃ / min, the signal-to-noise ratio decreases by 0.01dB for every 1℃ / min increase. For example, when the rate of change of temperature difference is 35℃ / min, the current signal-to-noise ratio is 0.4dB, and the signal-to-noise ratio decreases to 0.4dB - 0.1dB × 5 = 0.35dB.

[0095] In practice, the system of the present invention sets a preset second rate of change. When the rate of change is large, it indicates that the heating rate inside the cavity of the cylinder head is increasing. The ultrasonic signal may be affected by factors such as thermal expansion of the cylinder head material during propagation. At this time, the temperature change inside the cylinder head is drastic, which leads to changes in cylinder head stress. The speed of ultrasonic waves during propagation is affected by temperature, so by reducing the signal-to-noise ratio of the ultrasonic transmitter, the false detection rate can be reduced, and the accuracy of the detection results can be improved.

[0096] Specifically, the control module is connected to the ultrasonic component and is used to initially determine that the stability of the signal transmission does not meet the requirements when the rate of change of the temperature difference is greater than a preset first rate of change and less than or equal to a preset second rate of change, and to obtain the electroacoustic efficiency of the ultrasonic signal of the ultrasonic component.

[0097] If the electroacoustic efficiency is less than a preset first electroacoustic efficiency, the stability of the signal transmission is determined to be unsatisfactory, and the heights of the first and second ultrasonic transmitters are increased respectively.

[0098] The height is negatively correlated with the electroacoustic efficiency.

[0099] Specifically, the electroacoustic efficiency of an ultrasonic signal is the efficiency of converting the mechanical energy of an ultrasonic transmitter into sound energy; the electroacoustic efficiency is detected by a power tester connected to the first and second ultrasonic transmitters respectively.

[0100] Specifically, the preset first electroacoustic efficiency is generally within the range of [88%, 92%], and the preset second electroacoustic efficiency is generally within the range of [93%, 95%].

[0101] Preferably, the first electroacoustic efficiency is 90% in a preferred embodiment, and the second electroacoustic efficiency is 94% in a preferred embodiment.

[0102] In practice, when the difference between the preset first electroacoustic efficiency and the electroacoustic efficiency is within 1%, the height of the ultrasonic transmitter increases by 3cm. For every 1% difference between the preset first electroacoustic efficiency and the electroacoustic efficiency, the height increases by 1cm. For example, if the electroacoustic efficiency is 88% and the current height is 14cm, the height will increase to 14cm + 3cm + 1cm = 18cm.

[0103] In practice, the system of the present invention sets a preset first electroacoustic efficiency and a preset second electroacoustic efficiency. The temperature inside the chamber rises through heat conduction from the cylinder head. When the temperature rises, the resistance of the transmission line of the ultrasonic transmitter increases, and the electroacoustic efficiency of the ultrasonic signal decreases. If the electroacoustic efficiency is lower than the preset first electroacoustic efficiency, it indicates that the stability of signal transmission may be affected. Therefore, by increasing the height of the ultrasonic transmitter, i.e. reducing the bends in the transmission line, the resistance of the line is reduced, thereby improving the electroacoustic efficiency of the ultrasonic signal and improving the stability of signal transmission.

[0104] Specifically, the control module is connected to both the ultrasonic component and the infrared thermal imaging thermometer. It is used to preliminarily determine that the transmission stability of the ultrasonic signal does not meet the requirements when the electroacoustic efficiency is greater than or equal to the preset first electroacoustic efficiency and less than the preset second electroacoustic efficiency, and to calculate the deviation between the echo signals of the first and second ultrasonic transmitters.

[0105] If the deviation is greater than the preset deviation, the transmission stability of the ultrasonic signal is determined to be unsatisfactory, and the distances between the first ultrasonic transmitter and the second ultrasonic transmitter and the cylinder head are reduced to positions that meet the detection temperature conditions.

[0106] Specifically, the deviation of the echo signal is the absolute value of the difference between the peak sound pressure of the echo signal of the first ultrasonic transmitter after the heating of the thermal fatigue simulation module has stopped and the echo signal of the second ultrasonic transmitter after the heating of the thermal fatigue simulation module has stopped.

[0107] The temperature detection condition is the end position of the unit length when the air temperature difference is at its maximum value among several unit lengths of air temperature difference between the first ultrasonic transmitter and the second ultrasonic transmitter and the cylinder head, respectively.

[0108] The air temperature difference per unit length is the difference between the air temperature at the end of the unit length and the air temperature at the beginning of the unit length.

[0109] Specifically, the general range of the preset deviation is [0.4 Pa, 1 Pa], and the preferred embodiment of the preset deviation is 0.6 Pa.

[0110] In practice, the system of the present invention further incorporates a deviation setting. Since the ultrasonic device experiences deviations due to temperature fluctuations during thermal fatigue testing, the system verifies the test results of the two ultrasonic transmitters against each other to determine if the transmitters are fatigued due to frequent temperature increases and decreases in the environment. When the deviation exceeds the normal range, it indicates a potential large error in the ultrasonic transmitter's test results. Because heat dissipation from the cylinder head to the surrounding environment creates a temperature gradient within the testing space, the error range increases under the influence of this temperature gradient. By reducing the distance between the ultrasonic transmitter and the cylinder head, the influence of air temperature differences on sound wave propagation is reduced, thereby improving the accuracy of ultrasonic testing.

[0111] Specifically, the control module is connected to the temperature measuring component to obtain the cooling rate of the inner wall of the cylinder head after the thermal fatigue simulation module stops heating. If the cooling rate is greater than the preset cooling rate, it is determined that the stability of the echo signal does not meet the requirements, and the alternating detection frequency of the first ultrasonic transmitter and the second ultrasonic transmitter is increased.

[0112] Specifically, the alternating detection frequency is the number of times the first ultrasonic transmitter and the second ultrasonic transmitter alternately detect each other per unit detection time; the alternating detection frequency is positively correlated with the cooling rate.

[0113] Specifically, the cooling rate is the rate at which the temperature of the inner wall of the cylinder head decreases within a unit temperature monitoring time after the high-frequency induction heater stops working.

[0114] Specifically, the preset cooling rate is generally set within the range of [18℃ / min, 24℃ / min].

[0115] Preferably, the preferred embodiment of the preset first cooling rate is 20°C / min.

[0116] In practice, when the difference between the cooling rate and the preset cooling rate is within 1℃ / min, the alternating detection frequency increases by 2 times / min. When the difference between the cooling rate and the preset cooling rate exceeds 1℃ / min, the alternating detection frequency increases by 1 time / min for every 1℃ / min increase. For example, if the cooling rate is 36℃ / min and the current alternating detection frequency is 12 times / min, the alternating detection frequency increases to 12 times / min + 2 times / min + 1 time / min = 15 times / min.

[0117] In practice, the system described in this invention sets a cooling rate. Because the cylinder head dissipates heat from the air and then is connected to cooling, the ultrasonic propagation rate decreases, and the cylinder head stress is released. During the cooling process of the cylinder head, the shrinkage of the cylinder head material may cause cracks to be generated or propagated. At this time, the control module increases the alternating detection frequency of the ultrasonic transmitter to more accurately capture the dynamic changes of the cracks. If the cooling rate is too high, it may cause the stability of the ultrasonic signal echo to decrease. By increasing the alternating detection frequency, that is, increasing the detection frequency of the ultrasonic transmitter, the signal-to-noise ratio of the ultrasonic signal is improved, thereby improving the accuracy and stability of thermal fatigue detection.

[0118] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. An intelligent production system based on engine cylinder head thermal fatigue detection, comprising a housing, characterized in that, Also includes: The production module is used to output the cylinder head; A thermal fatigue simulation module is located at the bottom of the box and simulates the thermal fatigue process of the cylinder head by heating the cylinder head output by the production module. The detection module, which is connected to the thermal fatigue simulation module, is used to detect the degree of thermal fatigue of the cylinder head. It includes an ultrasonic component that performs ultrasonic testing on the cylinder head to determine whether the cylinder head has cracks, and a temperature measuring component connected to the cylinder head to detect the air temperature around the cylinder head and the temperature parameters of the cylinder head. The ultrasound component includes: A first ultrasonic transmitter is located inside the housing; The second ultrasonic transmitter is arranged in parallel behind the first ultrasonic transmitter. The first slider telescopic rod is connected to the first ultrasonic transmitter and is used to adjust the distance between the first ultrasonic transmitter and the cylinder head and the height between the first ultrasonic transmitter and the lower surface of the housing. The second slider telescopic rod is connected to the second ultrasonic transmitter and is used to adjust the distance between the second ultrasonic transmitter and the cylinder head and the height between the second ultrasonic transmitter and the lower surface of the housing; The heights of the first ultrasonic transmitter and the second ultrasonic transmitter are equal to the height of the cylinder head; The temperature measuring component includes: A first temperature sensor is disposed on the inner wall of the cylinder head to detect the temperature of the inner wall of the cylinder head. The second temperature sensor is disposed on the outer wall of the cylinder head to detect the temperature of the outer wall of the cylinder head; An infrared thermal imaging thermometer is positioned above the second temperature sensor to detect the air temperature between the first ultrasonic transmitter and the second ultrasonic transmitter and the cylinder head, respectively. A control module, connected to both the thermal fatigue simulation module and the detection module, is used to determine the adjustment method for ultrasonic testing based on the temperature difference between the inner and outer walls of the cylinder head. This includes adjusting the signal-to-noise ratio of the ultrasonic components based on the rate of change of the temperature difference between the inner and outer walls of the cylinder head. Alternatively, the height of the ultrasonic signal can be adjusted based on its electroacoustic efficiency. Alternatively, the distance between the ultrasonic component and the cylinder head can be determined based on the deviation of the echo signal, or the alternating detection frequency of the ultrasonic component can be adjusted based on the cooling rate of the cylinder head. The rate of change of temperature difference is the ratio of the difference between the inner wall temperature and the outer wall temperature of the cylinder head to the unit detection time of the thermal fatigue simulation operation cycle.

2. The intelligent production system based on engine cylinder head thermal fatigue detection according to claim 1, characterized in that, The control module is connected to both the temperature measuring component and the ultrasonic component to obtain the rate of change of the temperature difference between the inner and outer walls of the cylinder head during the detection phase. If the rate of change of the temperature difference is greater than the preset second rate of change, it is determined that the accuracy of the ultrasonic detection does not meet the requirements, and the signal-to-noise ratio of the first ultrasonic transmitter and the second ultrasonic transmitter are reduced respectively.

3. The intelligent production system based on engine cylinder head thermal fatigue detection according to claim 2, characterized in that, The signal-to-noise ratio is negatively correlated with the rate of change of the temperature difference.

4. The intelligent production system based on engine cylinder head thermal fatigue detection according to claim 3, characterized in that, The control module is connected to the ultrasonic component and is used to initially determine that the stability of the signal transmission does not meet the requirements when the rate of change of the temperature difference is greater than a preset first rate of change and less than or equal to a preset second rate of change, and to obtain the electroacoustic efficiency of the ultrasonic signal of the ultrasonic component. If the electroacoustic efficiency is less than a preset first electroacoustic efficiency, the stability of the signal transmission is determined to be unsatisfactory, and the heights of the first and second ultrasonic transmitters are increased respectively. The height is negatively correlated with the electroacoustic efficiency.

5. The intelligent production system based on engine cylinder head thermal fatigue detection according to claim 4, characterized in that, The control module is connected to both the ultrasonic component and the infrared thermal imaging thermometer. It is used to preliminarily determine that the transmission stability of the ultrasonic signal does not meet the requirements when the electroacoustic efficiency is greater than or equal to the preset first electroacoustic efficiency and less than the preset second electroacoustic efficiency, and to calculate the deviation between the echo signals of the first and second ultrasonic transmitters. If the deviation is greater than the preset deviation, the transmission stability of the ultrasonic signal is determined to be unsatisfactory, and the distances between the first ultrasonic transmitter and the second ultrasonic transmitter and the cylinder head are reduced to positions that meet the detection temperature conditions.

6. The intelligent production system based on engine cylinder head thermal fatigue detection according to claim 5, characterized in that, The deviation of the echo signal is the absolute value of the difference between the peak sound pressure of the echo signal of the first ultrasonic transmitter after the heating of the thermal fatigue simulation module has stopped and the echo signal of the second ultrasonic transmitter after the heating of the thermal fatigue simulation module has stopped. The temperature detection condition is the end position of the unit length when the air temperature difference is at its maximum value among several unit lengths of air temperature difference between the first ultrasonic transmitter and the second ultrasonic transmitter and the cylinder head, respectively. The air temperature difference per unit length is the difference between the air temperature at the end of the unit length and the air temperature at the beginning of the unit length.

7. The intelligent production system based on engine cylinder head thermal fatigue detection according to claim 6, characterized in that, The control module is connected to the temperature measuring component to obtain the cooling rate of the inner wall of the cylinder head after the thermal fatigue simulation module stops heating. If the cooling rate is greater than the preset cooling rate, it is determined that the stability of the echo signal does not meet the requirements, and the alternating detection frequency of the first ultrasonic transmitter and the second ultrasonic transmitter is increased.

8. The intelligent production system based on engine cylinder head thermal fatigue detection according to claim 7, characterized in that, The alternating detection frequency is the number of times the first ultrasonic transmitter and the second ultrasonic transmitter alternately detect each other per unit detection time; the alternating detection frequency is positively correlated with the cooling rate.

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