Hydraulic automatic transmission oil viscosity sensor based on magnetostrictive material

Abstract

The application belongs to the technical field of transmission system monitoring and diagnosis, and particularly relates to a hydraulic automatic transmission oil viscosity sensor based on magnetostrictive material. The sensor comprises a sensor main body, a magnetostrictive transducer, an oil inlet and an oil outlet, a flow channel device, a T-shaped detection cavity and a magnetic field generating device. The sensor utilizes the physical characteristics of magnetostrictive material to realize high-precision and high-sensitivity real-time on-site detection of oil viscosity, reduces the cost of detection instruments and simplifies the maintenance requirements, can meet real-time monitoring of the state of lubricating oil, and can also perform on-site sampling detection.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of transmission system monitoring and diagnosis, and particularly relates to a hydraulic automatic transmission oil viscosity sensor based on magnetostrictive material. BACKGROUND

[0002] Oil viscosity is one of the most important performances of a hydraulic automatic transmission. Generally, the smaller the oil viscosity, the smaller the energy loss of gear stirring oil, and the higher the transmission efficiency of the hydraulic automatic transmission. However, when the oil viscosity is too small, the leakage of the hydraulic system of the automatic transmission will increase, further affecting the oil pressure of the clutch hydraulic cavity of the automatic transmission, thereby reducing the shift quality and shortening the service life, and even causing failure in serious cases. On the contrary, as the oil viscosity increases, the power consumed by gear stirring oil will increase, thereby reducing the transmission efficiency of the automatic transmission and increasing the starting torque. At the same time, the solenoid valve in the hydraulic system will have a long response time due to the high oil viscosity, the clutch oil filling time will be prolonged, the shift delay will occur, the sliding friction work will be increased, the friction plate in the clutch will be burned, and finally the automatic transmission will fail. In addition, high-viscosity hydraulic automatic transmission oil can also cause oil pump suction and other problems. Therefore, the oil of the automatic transmission needs to be monitored in real time to ensure reasonable oil change time and shift parameters, so as to ensure the normal operation of the automatic transmission with high efficiency and no failure, and through the monitoring of the oil viscosity, the health status of the oil and the automatic transmission can be judged to provide maintenance basis for maintenance personnel.

[0003] The oil monitoring technology of the automatic transmission is an effective method of working condition monitoring and fault diagnosis, which obtains the lubrication state information of the automatic transmission by collecting the oil sample of the automatic transmission and analyzing the changes of the physical and chemical performance indexes of the lubricating oil of the automatic transmission. At present, in the equipment maintenance, the offline technology is mainly used to monitor the performance and state of the oil, and the oil sample collected on site is sent to the detection center for testing of the physical and chemical performance indexes. This detection method has the following disadvantages: the detection equipment is bulky, only suitable for offline analysis in laboratory environment, not suitable for online or on-site analysis and testing; the result cycle time is long, which cannot meet the real-time requirement; the testing instrument cost is high, and the maintenance and operation technology requirement is also high, which is not suitable for on-site monitoring. More importantly, the oil viscosity detection equipment cannot be used as an optional component of the automatic transmission for detection in the real vehicle. At the same time, the oil monitoring of the automatic transmission can also be used for control feedback to improve the shift quality.

[0004] Therefore, it is necessary to find a low-cost oil viscosity sensor which can perform on-site real-time detection of oil viscosity while maintaining high precision and high sensitivity, can be used as an optional component of the automatic transmission, and can simplify the maintenance and operation technology requirement of the monitoring equipment. SUMMARY

[0005] Technical problems to be solved

[0006] The technical problem to be solved by the present application is how to develop a low-cost oil viscosity sensor that can be used as an optional component of an automatic transmission, which can realize real-time and rapid detection and monitoring of the oil viscosity of a hydraulic automatic transmission while maintaining high precision and high sensitivity, and provide maintenance personnel with maintenance basis for the health status of the oil and the automatic transmission, and simplify the maintenance and operation technical requirements of the monitoring equipment.

[0007] Technical solutions

[0008] In order to solve the above technical problems, the present application provides a hydraulic automatic transmission oil viscosity sensor based on magnetostrictive material, which comprises: a sensor body, a magnetostrictive transducer ①, an oil inlet and an oil outlet ②, a flow channel device ③, a T-shaped detection cavity ④, and a magnetic field generating device ⑤.

[0009] The sensor body is a hollow structure, which constitutes the main profile of the sensor.

[0010] The sensor body is provided with an oil inlet and an oil outlet ② connected with oil pipes at both ends, respectively.

[0011] The built-in flow channel device ③ is horizontally arranged between the two ports of the oil inlet and the oil outlet ②.

[0012] The T-shaped detection cavity ④ is vertically arranged directly below the flow channel device ③.

[0013] The magnetostrictive transducer ① is vertically arranged in the middle of the T-shaped detection cavity ④.

[0014] The magnetic field generating device ⑤ is arranged outside the T-shaped detection cavity ④.

[0015] The top of the sensor body is also provided with a top sample replacement port ⑥.

[0016] The magnetostrictive transducer ① uses an iron-based amorphous alloy thin film material as a substrate.

[0017] The magnetostrictive transducer ① uses an Fe-Ni amorphous alloy material thin film.

[0018] The thickness of the thin film material is 15μm, and the surface of the outer layer of the thin film is respectively coated with a chromium layer and a gold layer by plasma sputtering to form the magnetostrictive transducer ①.

[0019] The magnetostrictive transducer ① is a rectangular film, vertically standing in the T-shaped detection cavity ④ along the length direction, and without any constraint in the vertical direction of the T-shaped detection cavity ④, so as to ensure that the magnetostrictive transducer ① can freely vibrate.

[0020] The repeatedly used magnetostrictive transducer ① can be replaced through the top sample replacement port ⑥.

[0021] The magnetic field generating device ⑤ is located at the periphery and the lower side of the T-shaped detection cavity ④, and comprises a permanent magnet, a solenoid, and a network analyzer connected with the solenoid.

[0022] The permanent magnet is located below the T-shaped detection cavity ④, and the solenoid is wound around the periphery of the T-shaped detection cavity ④ and connected to the network analyzer through a wire.

[0023] The magnetic field of the sensor comprises a constant magnetic field and an alternating magnetic field; the constant magnetic field is generated by the permanent magnet, and the magnetic field lines thereof are along the length direction of the magnetostrictive transducer ①; the alternating magnetic field is generated by the energized solenoid wound around the periphery of the T-shaped detection cavity ④, and the magnetic field lines thereof are along the length direction of the magnetostrictive transducer ①; the energized solenoid is a common coil of the excitation coil and the detection coil; when the network analyzer outputs an alternating current to the solenoid, the alternating magnetic field and the direct current magnetic field generated by the solenoid and the permanent magnet respectively interact, so that the magnetostrictive transducer ① placed in the T-shaped detection cavity ④ generates resonance phenomenon, and the frequency and amplitude of the resonance phenomenon are returned to the network analyzer through the detection coil.

[0024] With the increase of the viscosity of the oil, the resonance frequency and amplitude of the magnetostrictive transducer ① change linearly.

[0025] The viscosity state of the oil is calculated by sensing the resonance frequency change.

[0026] In the T-shaped detection cavity ④, the magnetostrictive transducer ① is a completely unbound rectangular magnetoelastic film strip; due to the magnetostrictive effect, the sensor mechanically vibrates at a certain frequency under the alternating magnetic field and the constant magnetic field, which is manifested as shape or position change; at the same time, an induced magnetic flux is generated, which is used as a response signal, detected by the detection coil, and the frequency and amplitude of the vibration response signal are displayed by the network analyzer; the resonance frequency of the sensor is:

[0027]

[0028] Wherein, n=1, 2, 3, …, is a modal value, L is the length of the sensor, E S is the Young's modulus, p S is the density of the sensor, and σ is the Poisson's ratio.

[0029] Wherein, when magnetostrictive sensor ① is immersed in liquid, it is subjected to the shearing force of the liquid, the value of which is negatively related to the viscosity of the liquid, so that the resonance frequency and vibration amplitude of the sensor are reduced; with the increase of the viscosity of the liquid, the resonance frequency trough gradually moves to the left, and the peak-peak distance gradually decreases; the resonance frequency change of the sensor is:

[0030]

[0031] Wherein, p l is the density of the fluid to be measured, η is the viscosity of the fluid to be measured, f0 is the inherent resonance frequency of the sensor, and d is the characteristic length;

[0032] Therefore, it is shown that the resonance frequency change of the sensor is proportional to the square root of the product of the viscosity and the density of the liquid; in the case that the density of the liquid to be measured is known, the viscosity of the liquid can be measured.

[0033] (Three) beneficial effects

[0034] The application provides a real-time oil viscosity detection sensor of a hydraulic automatic transmission. The sensor utilizes the physical characteristics of magnetostrictive material to realize high-precision and high-sensitivity real-time on-site detection of oil viscosity, reduces the cost of detection instruments and simplifies maintenance requirements, can meet real-time monitoring of the state of lubricating oil, and can also perform on-site sampling detection.

[0035] Compared with the prior art, the technical effects of the application are:

[0036] (1) Small-size magnetostrictive film material is adopted, and the precision and sensitivity are high;

[0037] (2) On-site real-time rapid detection is realized, and on-site sampling detection can also be performed;

[0038] (3) The whole sensor adopts an all-aluminum structure, and is low in cost and light in weight, and can be used as an automatic transmission or other equipment optional component;

[0039] (4) Key parts of the equipment are only iron-based magnetostrictive film material and a solenoid, and can be reused;

[0040] (5) The transducer component has simple preparation process, corrosion resistance, high temperature resistance and low cost;

[0041] (6) Maintenance and operation are simple, and complex disassembly is not needed, and the transducer component can be directly replaced through the top sample replacement opening. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 It is a schematic view of the magnetostrictive oil viscosity sensor of the application.

[0043] Figure 2Fig. 1 is a schematic diagram of a resonant frequency waveform of a magnetostrictive sensor.

[0044] Figure 3 Fig. 2 is a schematic diagram of a resonant frequency waveform change of a magnetostrictive sensor. DETAILED DESCRIPTION

[0045] In order to make the objects, contents and advantages of the present application clearer, the specific embodiments of the present application are described in further detail below in combination with the drawings and examples.

[0046] In order to solve the above technical problems, the present application provides a kind of based on magnetostrictive material's hydraulic automatic transmission oil viscosity sensor, as shown in Figure 1 The sensor includes: sensor body, magnetostrictive transducer ①, oil inlet and oil outlet ②, flow channel device ③, T-shaped detection cavity ④, magnetic field generating device ⑤;

[0047] The sensor body is a hollow structure, which constitutes the main profile of the sensor.

[0048] The two ends of the sensor body are provided with oil inlet and oil outlet ② connected with oil pipeline respectively.

[0049] The built-in flow channel device ③ is horizontally arranged between the two ports of the oil inlet and oil outlet ②.

[0050] The T-shaped detection cavity ④ is vertically arranged directly below the flow channel device ③.

[0051] The magnetostrictive transducer ① is vertically arranged in the middle of the T-shaped detection cavity ④.

[0052] The magnetic field generating device ⑤ is arranged outside the T-shaped detection cavity ④.

[0053] The top of the sensor body is also provided with a top sample replacement port ⑥.

[0054] The magnetostrictive transducer ① is based on Fe-based amorphous alloy thin film material.

[0055] The magnetostrictive transducer ① adopts Fe-Ni amorphous alloy material thin film.

[0056] The thickness of the thin film material is 15 μm, and the surface of the outer layer of the thin film is respectively coated with chromium layer and gold layer by plasma sputtering, so as to form the magnetostrictive transducer ①.

[0057] The magnetostrictive transducer ① is a rectangular thin film, which is vertically arranged in the T-shaped detection cavity ④ along the length direction, and is not constrained in the vertical direction of the T-shaped detection cavity ④, so as to ensure that the magnetostrictive transducer ① can vibrate freely.

[0058] Wherein, through the top sample replacement port ⑥, the repeated use of magnetostrictive transducer ① can be replaced.

[0059] Wherein, the magnetic field generating device ⑤ is located in the T-shaped detection cavity ④ outside and the lower side, including permanent magnet, solenoid, and network analyzer connected with solenoid;

[0060] Wherein, the permanent magnet is located below the T-shaped detection cavity ④, and the solenoid is wound around the periphery of the T-shaped detection cavity ④ and connected to the network analyzer through the wire;

[0061] The magnetic field of the sensor includes constant magnetic field and alternating magnetic field; wherein, the constant magnetic field is generated by the permanent magnet, and the magnetic field line is along the length direction of the magnetostrictive transducer ①; the alternating magnetic field is generated by the energized solenoid wound around the periphery of the T-shaped detection cavity ④, and the magnetic field line is along the length direction of the magnetostrictive transducer ①; the energized solenoid is a common coil of the excitation coil and the detection coil, when the network analyzer outputs an alternating current to the solenoid, the interaction of the alternating magnetic field and the direct current magnetic field generated by the solenoid and the permanent magnet respectively makes the magnetostrictive transducer ① placed in the T-shaped detection cavity ④ produce resonance phenomenon, and returns the frequency and amplitude of the resonance phenomenon to the network analyzer through the detection coil;

[0062] With the increase of oil viscosity, the resonance frequency and amplitude of the magnetostrictive transducer ① change linearly;

[0063] By sensing the resonance frequency change, the viscosity state of the oil is calculated.

[0064] Wherein, in the T-shaped detection cavity ④, the magnetostrictive transducer ① is a completely unbound rectangular magnetoelastic film strip; due to the magnetostrictive effect, under the action of alternating magnetic field and constant magnetic field, the sensor vibrates mechanically at a certain frequency, which shows shape or position change; at the same time, the induced magnetic flux is generated, which is used as the response signal, detected by the detection coil, and the frequency and amplitude of the vibration response signal are displayed by the network analyzer; the resonance frequency of the sensor is:

[0065]

[0066] Wherein, n = 1, 2, 3, …, is the modal value, L is the length of the sensor, E S is the Young's modulus, p S is the density of the sensor, and sigma is the Poisson's ratio.

[0067] Wherein, when the magnetostrictive sensor ① is immersed in the liquid, it is subjected to the shear force of the liquid, the value of which is negatively related to the viscosity of the liquid, so that the resonance frequency and the vibration amplitude of the sensor are reduced; with the increase of the viscosity of the liquid, the resonance frequency valley gradually moves to the left, and the peak-peak distance gradually decreases, as shown in Figure 3 The resonance frequency change of the sensor is:

[0068]

[0069] Wherein, p l is the density of the fluid to be measured, η is the viscosity of the fluid to be measured, f0 is the inherent resonance frequency of the sensor, and d is the characteristic length;

[0070] It is shown that the resonance frequency change of the sensor is positively related to the square root of the product of the viscosity and the density of the liquid; in the case where the density of the liquid to be measured is known, the viscosity of the liquid can be measured.

[0071] Embodiment 1

[0072] The online real-time oil viscosity detection sensor provided by the application is suitable for an oil viscosity monitoring system. As shown in Figure 1 , the overall shape of the sensor is a flow channel type, which includes a magnetostrictive transducer ①, an oil inlet and an outlet ② installed at both ends of the sensor and connected with oil pipelines respectively, an internal flow channel device ③, a T-shaped detection cavity ④ for restricting the position of the magnetostrictive transducer, a magnetic field generating device ⑤ placed outside the T-shaped detection cavity, and a top sample replacement port ⑥. The magnetic field generating device is composed of a solenoid, a permanent magnet, and a network analyzer connected with the solenoid. The functions of each part and the specific detection principle and method will be described below with reference to Figure 1 .

[0073] The magnetostrictive transducer takes an iron-based amorphous alloy thin film material as a substrate, the thickness of the thin film material is 15 μm, and the surface of the thin film is coated with a chromium layer and a gold layer by plasma sputtering to form the magnetostrictive transducer. The magnetostrictive transducer is a rectangular thin film, which is vertically arranged in the T-shaped detection cavity along the length direction and is not restricted in the vertical direction of the T-shaped detection cavity, so as to ensure that the magnetostrictive transducer can vibrate freely. Through the top sample replacement port, the repeatedly used magnetostrictive transducer can be replaced.

[0074] The oil inlet, outlet, and internal flow channel are flow channels for oil, and there is no installation requirement for the flow direction.

[0075] The T-shaped detection cavity is located directly below the internal flow channel. For on-site real-time rapid detection, the oil passing through the internal flow channel enters the T-shaped detection cavity as a sample to be measured; for on-site sampling rapid detection, the sample to be measured can be injected into the T-shaped detection cavity through the top sample replacement port.

[0076] The magnetic field generating device is located at the periphery and the lower side of the T-shaped detection cavity, and includes a permanent magnet, a solenoid, and a network analyzer connected with the solenoid. The permanent magnet is located below the T-shaped detection cavity, and is 2-4 mm away from the lower end of the T-shaped detection cavity. The solenoid is wound around the periphery of the T-shaped detection cavity, and is connected to the network analyzer through a wire. The magnetic field of the sensor includes a constant magnetic field and an alternating magnetic field. The constant magnetic field is generated by the permanent magnet, and the magnetic field lines thereof are along the length direction of the magnetostrictive transducer. The alternating magnetic field is generated by the energized solenoid wound around the periphery of the T-shaped detection cavity, and the magnetic field lines thereof are also along the length direction of the magnetostrictive transducer. The energized solenoid is a common coil of the excitation coil and the detection coil. The network analyzer is used for generating the alternating magnetic field, and emitting and collecting the electrical signal.

[0077] In the T-shaped detection cavity, the magnetostrictive transducer is a completely unbound rectangular magnetoelastic film strip. Due to the magnetostrictive effect, under the alternating magnetic field and the constant magnetic field, the sensor mechanically vibrates at a certain frequency, which is manifested as shape or position change. At the same time, an induced magnetic flux is generated, which is used as a response signal, and is detected by the detection coil, and the frequency and amplitude of the vibration response signal are visualized by the network analyzer, as shown in FIG. 2. Figure 2 The resonance frequency of the sensor is:

[0078]

[0079] Wherein, n = 1, 2, 3, …, n, L is the length of the sensor, E S is the Young's modulus, p S is the density of the sensor, and s is the Poisson's ratio.

[0080] When the magnetostrictive sensor is immersed in a liquid, it is subjected to the shear force of the liquid, and the value thereof is negatively correlated with the viscosity of the liquid, so that the resonance frequency and the vibration amplitude of the sensor are reduced. With the increase of the viscosity of the liquid, the resonance frequency trough gradually moves to the left, and the peak-peak distance gradually decreases, as shown in FIG. 3. Figure 3 The resonance frequency change of the sensor is:

[0081]

[0082] Wherein, p l is the density of the fluid to be measured, η is the viscosity of the fluid to be measured, f0 is the inherent resonance frequency of the sensor, and d is the characteristic length.

[0083] It is shown that the resonance frequency change of the sensor is proportional to the square root of the product of the viscosity and the density of the liquid. In the case where the density of the liquid to be measured is known, the viscosity of the liquid can be measured.

[0084] The above merely describes the preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A magnetostrictive material-based hydraulic automatic transmission oil viscosity sensor, characterized by, The sensor comprises a sensor body, a magnetostrictive transducer (①), an oil inlet and an oil outlet (②), a flow channel device (③), a T-shaped detection cavity (④), and a magnetic field generating device (⑤); The sensor body is a hollow structure, which constitutes the main profile of the sensor; The sensor body is provided with an oil inlet and an oil outlet (②) at both ends, which are connected with oil pipelines respectively; The built-in flow channel device (③) is horizontally arranged between the two openings of the oil inlet and the oil outlet (②); The T-shaped detection cavity (④) is vertically arranged right below the flow channel device (③); The magnetostrictive transducer (①) is vertically arranged in the middle of the T-shaped detection cavity (④); The magnetic field generating device (⑤) is arranged outside the T-shaped detection cavity (④); The magnetic field generating device (⑤) is located at the periphery and the lower side of the T-shaped detection cavity (④), and comprises a permanent magnet, a solenoid, and a network analyzer connected with the solenoid; The permanent magnet is located below the T-shaped detection cavity (④), and the solenoid is wound around the periphery of the T-shaped detection cavity (④) and connected to the network analyzer through wires; The magnetic field of the sensor comprises a constant magnetic field and an alternating magnetic field; the constant magnetic field is generated by the permanent magnet, and the magnetic field lines are along the length direction of the magnetostrictive transducer (①); the alternating magnetic field is generated by the energized solenoid wound around the periphery of the T-shaped detection cavity (④), and the magnetic field lines are along the length direction of the magnetostrictive transducer (①); the energized solenoid is a common coil of the excitation coil and the detection coil; when the network analyzer outputs an alternating current to the solenoid, the alternating magnetic field and the direct current magnetic field generated by the solenoid and the permanent magnet respectively interact, so that the magnetostrictive transducer (①) placed in the T-shaped detection cavity (④) generates resonance phenomenon, and returns the frequency and amplitude of the resonance phenomenon to the network analyzer through the detection coil; With the increase of the viscosity of the oil, the resonance frequency and amplitude of the magnetostrictive transducer (①) change linearly; The viscosity state of the oil is calculated by sensing the resonance frequency change; In the T-shaped detection cavity (④), the magnetostrictive transducer (①) is a completely unbound rectangular magnetostrictive thin film; due to the magnetostrictive effect, the sensor mechanically vibrates at a certain frequency under the alternating magnetic field and the constant magnetic field, which is manifested as shape or position change; at the same time, an induced magnetic flux is generated, which is used as a response signal and detected by the detection coil, and the frequency and amplitude of the vibration response signal are displayed by the network analyzer; the resonance frequency of the sensor is: where n = 1, 2, 3,..., is the modal value, L is the sensor length, E S is the Young's modulus, p S is the sensor density, and s is the Poisson's ratio.

2. The magnetostrictive material-based hydraulic automatic transmission oil viscosity sensor according to claim 1, wherein The top of the sensor body is also provided with a top sample replacement opening (⑥).

3. The magnetostrictive material-based hydraulic automatic transmission oil viscosity sensor according to claim 2, wherein The magnetostrictive transducer (①) takes an iron-based amorphous alloy thin film material as a substrate.

4. The magnetostrictive material-based hydraulic automatic transmission oil viscosity sensor according to claim 2, wherein The magnetostrictive transducer (①) adopts Fe-Ni amorphous alloy material thin film.

5. The magnetostrictive material-based hydraulic automatic transmission oil viscosity sensor according to claim 3, wherein The thickness of the thin film material is 15 μm, and the surface of the outer layer of the thin film is respectively coated with a chromium layer and a gold layer by means of plasma sputtering, so as to form the magnetostrictive transducer (①).

6. The magnetostrictive material-based hydraulic automatic transmission oil viscosity sensor according to claim 3 or 4, characterized by The magnetostrictive transducer (①) is a rectangular film, vertically standing in the T-shaped detection cavity (④) along the length direction, and without any constraint in the vertical direction of the T-shaped detection cavity (④), so as to ensure that the magnetostrictive transducer (①) can freely vibrate.

7. The magnetostrictive material-based hydraulic automatic transmission oil viscosity sensor according to claim 3 or 4, characterized by, Through the top sample replacement port (⑥), the repeatedly used magnetostrictive transducer (①) can be replaced.

8. The magnetostrictive material-based hydraulic automatic transmission oil viscosity sensor according to claim 1, wherein When the magnetostrictive sensor (①) is immersed in a liquid, it is subjected to the shear force of the liquid, and the value thereof is negatively related to the viscosity of the liquid, so that the resonance frequency and the vibration amplitude of the sensor are reduced; with the increase of the viscosity of the liquid, the resonance frequency trough gradually moves to the left, and the peak-peak distance gradually decreases; the resonance frequency change of the sensor is: wherein p l is the density of the fluid under test, η is the viscosity of the fluid under test, f0 is the natural resonant frequency of the sensor, and d is a characteristic length. Therefore, it is shown that the resonance frequency change of the sensor is positively related to the square root of the product of the viscosity and the density of the liquid; in the case that the density of the liquid to be measured is known, the viscosity of the liquid can be measured.

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