阅读说明：本技术 发动机用高可靠环境适应性磁电转速传感器及制备方法 (High-reliability environment-adaptability magnetoelectric rotating speed sensor for engine and preparation method ) 是由 李永清 李洪儒 徐丹辉 胡延丽 马超 郑楠 祁静 梁永胜 金志东 李惠 于 2020-07-09 设计创作，主要内容包括：本发明公开了一种发动机用高可靠环境适应性磁电转速传感器及其制备方法,所述传感器包括测试齿轮和传感器主体,所述传感器主体包括壳体、骨架、铁芯,在铁芯的后端设置有磁钢,在骨架的外侧采用并行同步的方式绕制有两组感应线圈；在传感器的壳体内部后端,介于感应线圈与信号输出线之间,设置有两组环形变压器；环形变压器的初级引出线与两组感应线圈的引出线相连接,次级引出线与转速信号输出线相连接；所述转速信号输出线从壳体后端伸出并与尾附件相连接。本发明可保证两路感应线圈完全对称,两路感应线圈输出的转速信号可完全同步,提高了准确性。同时还能大幅提升低转速条件下的转速信号输出幅值,有效满足了转速信号最低输出幅值的要求。(The invention discloses a high-reliability environment-adaptability magnetoelectric rotation speed sensor for an engine and a preparation method thereof, wherein the sensor comprises a test gear and a sensor main body, the sensor main body comprises a shell, a framework and an iron core, magnetic steel is arranged at the rear end of the iron core, and two groups of induction coils are wound on the outer side of the framework in a parallel and synchronous manner; two groups of ring transformers are arranged at the rear end in the shell of the sensor between the induction coil and the signal output line; the primary outgoing lines of the annular transformer are connected with the outgoing lines of the two groups of induction coils, and the secondary outgoing lines of the annular transformer are connected with the rotating speed signal output line; the rotating speed signal output line extends out of the rear end of the shell and is connected with the tail accessory. The invention can ensure that the two induction coils are completely symmetrical, the rotating speed signals output by the two induction coils can be completely synchronous, and the accuracy is improved. Meanwhile, the output amplitude of the rotating speed signal under the condition of low rotating speed can be greatly improved, and the requirement of the lowest output amplitude of the rotating speed signal is effectively met.)

1. Magnetoelectric revolution speed sensor of high reliable environmental suitability for engine, including test gear and sensor main part, its characterized in that: the sensor main body comprises a shell, a framework is arranged at the front end in the shell, an iron core is arranged in the framework, magnetic steel is arranged at the rear end of the iron core, and two groups of induction coils are wound on the outer side of the framework in a parallel and synchronous mode; two groups of ring transformers are arranged at the rear end in the shell of the sensor between the induction coil and the signal output line; the primary outgoing lines of the annular transformer are connected with the outgoing lines of the two groups of induction coils, and the secondary outgoing lines of the annular transformer are connected with the rotating speed signal output line; the rotating speed signal output line extends out of the rear end of the shell and is connected with the tail accessory.

2. The sensor of claim 1, wherein: the iron core runs through in the cavity inboard of skeleton, and the magnet steel passes through strong magnetic attraction to be fixed in the rear end of iron core, adopts high temperature resistant epoxy glue fixed between iron core and the skeleton, and the casing is inside to adopt high temperature resistant epoxy glue to fill the embedment.

3. The sensor of claim 1, wherein: the rear end of the shell is in threaded connection with a locking nut, and a rubber plug used for sealing and a pressing ring matched with the protection spring are arranged on the inner side of the locking nut.

4. The sensor of claim 1, wherein: the shell is made of 316L stainless steel; the induction coil of the sensor is made of high-temperature resistant enameled wire; the magnetic steel of the sensor adopts high-temperature resistant neodymium iron boron (Nd)₂Fe₁₄B) The sensor rotating speed signal output line cable is made of TPE-thermoplastic polyester elastomer materials.

5. The sensor of claim 1, wherein: the thickness of the measuring end face of the sensor is not more than 0.15 mm.

6. A preparation method of a magnetoelectric rotation speed sensor with high reliability and environmental adaptability for an engine is characterized by comprising the following steps: the method comprises the following steps:

step 1, preparing a test gear, a shell and a framework structure,

2, tightly winding two groups of induction coils on the framework in a synchronous parallel mode, connecting the coils with outgoing lines after winding is finished, and tightly winding and fixing the coils by using a high-temperature adhesive tape;

step 3, dipping the iron core in high-temperature epoxy glue, and implanting the iron core into the inner side of the framework cavity; implanting magnetic steel into the inner side of the cavity at the rear part of the framework, and tightly connecting and fixing the magnetic steel with the iron core by strong magnetic force to form a whole;

step 4, winding the annular transformer, connecting the coil with a lead-out wire after winding is finished, and tightly fixing the coil by adopting a temperature-resistant adhesive tape and silica gel;

step 5, integrally implanting the manufactured rotating speed induction coil into a sensor shell, filling and fixing by adopting temperature-resistant epoxy glue, controlling the thickness of the glue to be in the integral margin of the coil, and curing; the primary outgoing lines of the annular transformer are respectively connected with the outgoing lines of the two groups of rotating speed coils, and the secondary outgoing lines of the annular transformer are respectively connected with a rotating speed signal output line;

step 6, integrally encapsulating the core body in the shell by using temperature-resistant epoxy glue, controlling the thickness of the glue to be higher than the marginal of the core body by 2mm, standing for 24 hours at normal temperature, and drying for 8 hours at high temperature of 120 ℃ to completely cure;

and 7, coating le Tai medium-strength thread glue on the thread of the locking nut, screwing the locking nut and the shell by using a torque wrench, extruding the rubber plug by the locking nut through the pressing ring, and enabling the rubber plug to be in close contact and fit with the inner wall of the shell and the signal wire sheath, thus finishing the preparation process.

7. The method for preparing the magnetoelectric rotation speed sensor for the engine with the high reliable environmental adaptability according to the claim 6 is characterized in that: in step 2, the number of winding turns of the induction coil is 7500 turns; in step 4, when the toroidal transformer is wound, the primary winding is 1000 turns, and the secondary winding is 3000 turns.

Technical Field

The invention belongs to the technical field of engine measurement and control, and particularly relates to a high-reliability environment-adaptability magnetoelectric rotating speed sensor for an engine and a preparation method thereof.

Background

For a magnetoelectric wheel speed sensor, the accuracy and the reliability of measurement are the most key technical characteristics of the sensor, and the adoption of a dual-redundancy coil design mode is an effective means for realizing the key technical characteristics. At present, the existing dual-redundancy magnetoelectric rotation speed sensor mainly has two structural forms. One is that two sets of induction coils are double-deck coiling inside and outside same skeleton, and this kind of structure is because every turn of coil girth is different in the ectonexine, can't guarantee that the resistance and the number of turns of two sets of coils are identical completely, consequently, corresponds same rotational speed signal, and obvious difference will appear in the induced electromotive force of output, causes two redundancy output signal to appear asynchronous problem. And the other is that two groups of induction coils are arranged in the sensor shell in parallel. Because the area corresponding to the measuring end surface of the sensor and the outer tangent point of the convex tooth of the measuring gear is unique, namely the measuring end surface of the rotating speed sensor is just opposite to the area where the tangent point of the convex tooth of the measuring gear is located, the optimal rotating speed induction signal can be obtained, and if the two groups of induction coils are arranged in parallel in the sensor shell, the two groups of induction coils cannot be located in the optimal signal measuring area, so the method needs to be improved. Therefore, the two groups of coils can only adopt a mode of sharing the framework, the iron core and the magnetic steel. Because two paths of coils are wound in parallel, the number of winding turns is limited, the amplitude of signals output by the rotating speed is low, and the problem of low signal amplitude is more prominent particularly under the working condition of low rotating speed. Therefore, two paths of rotating speed signals need to be effectively amplified so as to meet the requirements of stable and reliable measurement of the rotating speed sensor.

When the magnetoelectric wheel speed sensor is in a low rotating speed, the anti-jamming capability of the whole magnetoelectric wheel speed sensor is poor due to the fact that the amplitude of an effective output signal is too small and the noise content is high, so that a related measurement and control system cannot accurately identify and measure, and the real running state of equipment in the low rotating speed cannot be accurately judged. Therefore, the rotation speed sensor is required to have outstanding performances of low rotation speed operation, high sensitivity, low noise and the like; because the rotating speed sensor is in the running environment of the engine and the working conditions are extremely severe, the rotating speed sensor is required to have good protection performances such as temperature resistance, oil resistance, corrosion resistance, vibration impact resistance and the like so as to meet the requirement of accurately and reliably measuring and controlling the rotating speed signal of the engine under the all-working-condition.

Disclosure of Invention

The invention aims to provide a magnetoelectric rotating speed sensor with high reliability and environmental adaptability for an engine, which aims to solve the problems in the prior art.

The invention is realized by the following technical scheme: the utility model provides a high reliable environmental suitability magnetoelectric revolution speed sensor for engine, includes test gear and sensor main part, its characterized in that: the sensor main body comprises a shell, a framework is arranged at the front end in the shell, an iron core is arranged in the framework, magnetic steel is arranged at the rear end of the iron core, and two groups of induction coils are wound on the outer side of the framework in a parallel and synchronous mode; two groups of ring transformers are arranged at the rear end in the shell of the sensor between the induction coil and the signal output line; the primary outgoing lines of the annular transformer are connected with the outgoing lines of the two groups of induction coils, and the secondary outgoing lines of the annular transformer are connected with the rotating speed signal output line; the rotating speed signal output line extends out of the rear end of the shell and is connected with the tail accessory.

Further: the iron core runs through in the cavity inboard of skeleton, and the magnet steel passes through strong magnetic attraction to be fixed in the rear end of iron core, adopts high temperature resistant epoxy glue fixed between iron core and the skeleton, and the casing is inside to adopt high temperature resistant epoxy glue to fill the embedment.

Further: the rear end of the shell is in threaded connection with a locking nut, and a rubber plug used for sealing and a pressing ring matched with the protection spring are arranged on the inner side of the locking nut.

Further: the shell is made of 316L stainless steel; the induction coil of the sensor is made of high-temperature resistant enameled wire; the magnetic steel of the sensor adopts high-temperature resistant neodymium iron boron (Nd)₂Fe₁₄B) The sensor rotating speed signal output line cable is made of TPE-thermoplastic polyester elastomer materials.

Further: the thickness of the measuring end face of the sensor is not more than 0.15 mm.

A preparation method of a magnetoelectric rotation speed sensor with high reliability and environmental adaptability for an engine is characterized by comprising the following steps: the method comprises the following steps:

step 1, preparing a test gear, a shell and a framework structure,

2, tightly winding two groups of induction coils on the framework in a synchronous parallel mode, connecting the coils with outgoing lines after winding is finished, and tightly winding and fixing the coils by using a high-temperature adhesive tape;

step 3, dipping the iron core in high-temperature epoxy glue, and implanting the iron core into the inner side of the framework cavity; implanting magnetic steel into the inner side of the cavity at the rear part of the framework, and tightly connecting and fixing the magnetic steel with the iron core by strong magnetic force to form a whole;

step 4, winding the annular transformer, connecting the coil with a lead-out wire after winding is finished, and tightly fixing the coil by adopting a temperature-resistant adhesive tape and silica gel;

step 5, integrally implanting the manufactured rotating speed induction coil into a sensor shell, filling and fixing by adopting temperature-resistant epoxy glue, controlling the thickness of the glue to be in the integral margin of the coil, and curing; the primary outgoing lines of the annular transformer are respectively connected with the outgoing lines of the two groups of rotating speed coils, and the secondary outgoing lines of the annular transformer are respectively connected with a rotating speed signal output line;

step 6, integrally encapsulating the core body in the shell by using temperature-resistant epoxy glue, controlling the thickness of the glue to be higher than the marginal of the core body by 2mm, standing for 24 hours at normal temperature, and drying for 8 hours at high temperature of 120 ℃ to completely cure;

and 7, coating le Tai medium-strength thread glue on the thread of the locking nut, screwing the locking nut and the shell by using a torque wrench, extruding the rubber plug by the locking nut through the pressing ring, and enabling the rubber plug to be in close contact and fit with the inner wall of the shell and the signal wire sheath, thus finishing the preparation process.

Further: in step 2, the number of winding turns of the induction coil is 7500 turns; in step 4, when the toroidal transformer is wound, the primary winding is 1000 turns, and the secondary winding is 3000 turns.

The invention has the following advantages: in the invention, a dual-redundancy synchronous coil output mode is adopted, two rotating speed signal induction coils are wound in a parallel and synchronous mode in the same rotating speed sensing shell, and the two induction coils share a framework, an iron core and magnetic steel. Therefore, the two induction coils can be ensured to be completely symmetrical, and the rotating speed signals output by the two induction coils can be completely synchronous. When two paths of rotating speed signals are synchronously output, the sensor can be judged to be in a normal working state at the moment; and once the abnormal conditions such as short circuit or open circuit occur to a certain path of rotation speed signal, the other path can still work independently. In addition, the structure can effectively avoid the problem that the consistency of the resistance and the number of turns of the two groups of coils and the complete synchronization of the output cannot be ensured because the two groups of induction coils are wound on the same framework in an internal-external double-layer mode. The amplification effect of the toroidal transformer is utilized to carry out secondary amplification on the rotating speed signal, so that the rotating speed signal output amplitude under the condition of low rotating speed can be greatly improved, and the requirement of the lowest output amplitude of the rotating speed signal is met.

In the scheme, a shell of the rotating speed sensor is made of 316L stainless steel, and the highest working temperature is 600 ℃; the induction coil of the sensor is made of high-temperature resistant enameled wire, and the maximum working temperature of the enameled wire can reach 220 ℃; the magnetic steel of the sensor adopts high-temperature resistant neodymium iron boron (Nd)₂Fe₁₄B) The working tolerance temperature can be from-200 ℃ to 300 ℃; the core (induction coil, permanent magnet, etc.) of the sensor adopts high temperature resistanceFilling and encapsulating epoxy glue, wherein the working temperature of the high-temperature-resistant epoxy glue can be kept at 240 ℃ for a long time; the sensor signal outgoing line cable is made of TPE-thermoplastic polyester elastomer material, and the maximum use temperature can reach 180 ℃; thereby ensuring overall wide temperature adaptability.

In the rotating speed signal output link, a low-pass filter circuit is designed by means of coil internal resistance and line impedance. Therefore, the interference of high-frequency noise signals can be effectively inhibited, the signal-to-noise ratio of the rotating speed output signals is improved, the rotating speed signal output quality is ensured, and the anti-electromagnetic interference capability of the sensor is enhanced. Low noise requirements are achieved.

In the scheme, the sensor shell is integrally processed by adopting stainless steel 316L; the signal cable sheath is made of TPE thermoplastic elastomer, and a rubber plug sealing and fixing mode is adopted, so that the fixing strength and the tensile property of the cable are effectively improved; the induction coil, the magnetic steel, the transformer coil and the like in the shell of the revolution speed transducer are all encapsulated by high-temperature-resistant epoxy resin glue in an integrated manner, so that the whole machine has excellent rigidity strength, and the requirements of vibration resistance and impact protection are met. And the design of vibration resistance and impact resistance is adopted, the vibration resistance acceleration is up to 50g, and the impact resistance acceleration is up to 100 g. Meanwhile, the sealing protection grade meets the requirement of IP 68.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a magnetoelectric rotation speed sensor in the scheme;

FIG. 2 is a schematic diagram showing the corresponding relationship between the output voltage, frequency and rotation speed of the magnetoelectric rotation speed sensor in the present embodiment;

fig. 3 is a waveform diagram of the rotation speed signal ring transformer after two-stage amplification in the scheme.

The sequence numbers in the figures illustrate: the test gear is 1, the shell is 2, the framework is 3, the iron core is 4, the magnetic steel is 5, the induction coil is 6, the annular transformer is 7, the rotating speed signal output line is 8, the tail accessory is 9, the electric connector is 10, the lock nut is 11, the rubber plug is 12, the press ring is 13, and the protection spring is 14.

Detailed Description

As shown in fig. 1-3, the high-reliability environment-adaptability magnetoelectric rotation speed sensor for the engine in the present scheme includes a test gear 1 and a sensor main body, which are connected with the engine to be tested and rotate synchronously; the sensor main body comprises a shell 2, a framework 3 is arranged at the front end in the shell, an iron core 4 is arranged in the framework, magnetic steel 5 is arranged at the rear end of the iron core, and two groups of induction coils 6 are wound on the outer side of the framework in a parallel and synchronous mode; two groups of ring transformers 7 are arranged at the rear end in the shell of the sensor between the induction coil and the signal output line; the primary outgoing line of the annular transformer is connected with the outgoing lines of the two groups of induction coils, and the secondary outgoing line is connected with the rotating speed signal output line 8; the rotating speed signal output line extends out of the rear end of the shell and is connected with the tail accessory 9.

Preferably: the iron core runs through in the cavity inboard of skeleton, and the magnet steel passes through strong magnetic attraction to be fixed in the rear end of iron core, adopts high temperature resistant epoxy glue fixed between iron core and the skeleton, and the casing is inside to adopt high temperature resistant epoxy glue to fill the embedment.

Preferably: the rear end of the shell is in threaded connection with a locking nut 11, and a rubber plug 12 for sealing and a pressing ring 13 matched with a protection spring 14 are arranged on the inner side of the locking nut.

Preferably: the shell is made of 316L stainless steel; the induction coil of the sensor is made of high-temperature resistant enameled wire; the magnetic steel of the sensor adopts high-temperature resistant neodymium iron boron (Nd)₂Fe₁₄B) The sensor rotating speed signal output line cable is made of TPE-thermoplastic polyester elastomer materials.

Preferably: the thickness of the measuring end face of the sensor is not more than 0.15 mm.

A preparation method of a magnetoelectric rotation speed sensor with high reliability and environmental adaptability for an engine is characterized by comprising the following steps: the method comprises the following steps:

step 1, preparing a test gear, a shell and a framework structure,

2, tightly winding two groups of induction coils on the framework in a synchronous parallel mode, connecting the coils with outgoing lines after winding is finished, and tightly winding and fixing the coils by using a high-temperature adhesive tape;

step 3, dipping the iron core in high-temperature epoxy glue, and implanting the iron core into the inner side of the framework cavity; implanting magnetic steel into the inner side of the cavity at the rear part of the framework, and tightly connecting and fixing the magnetic steel with the iron core by strong magnetic force to form a whole;

step 4, winding the annular transformer, connecting the coil with a lead-out wire after winding is finished, and tightly fixing the coil by adopting a temperature-resistant adhesive tape and silica gel;

step 5, integrally implanting the manufactured rotating speed induction coil into a sensor shell, filling and fixing by adopting temperature-resistant epoxy glue, controlling the thickness of the glue to be in the integral margin of the coil, and curing; the primary outgoing lines of the annular transformer are respectively connected with the outgoing lines of the two groups of rotating speed coils, and the secondary outgoing lines of the annular transformer are respectively connected with a rotating speed signal output line;

step 6, integrally encapsulating the core body in the shell by using temperature-resistant epoxy glue, controlling the thickness of the glue to be higher than the marginal of the core body by 2mm, standing for 24 hours at normal temperature, and drying for 8 hours at high temperature of 120 ℃ to completely cure;

and 7, coating le Tai medium-strength thread glue on the thread of the locking nut, screwing the locking nut and the shell by using a torque wrench, extruding the rubber plug by the locking nut through the pressing ring, and enabling the rubber plug to be in close contact and fit with the inner wall of the shell and the signal wire sheath, thus finishing the preparation process.

Preferably: in step 2, the number of winding turns of the induction coil is 7500 turns; in step 4, when the toroidal transformer is wound, the primary winding is 1000 turns, and the secondary winding is 3000 turns.

The working process of the scheme is as follows: the test gear is connected with rotating parts such as an engine and the like and synchronously rotates, in the rotating process, the tooth-shaped end face of the gear passes through the sensor at intervals to cut magnetic lines, induced electromotive force is generated in the induction coil, the induced electromotive force is amplified through a secondary amplifying circuit formed by the ring transformer, the amplified signal is transmitted to the electric connector 10 through an output line, and the electric connector plays a role in connecting the output line with an external circuit. The tail attachment is an attachment to an electrical connector.

The magnetoelectric speed sensor for the engine is different from other application occasions, and has the outstanding characteristics of severe working environment, complex test working condition, high reliability requirement and the like, so that more strict requirements are provided for the technical indexes of the sensor, such as temperature resistance, output performance, protective performance and the like.

The scheme adopts the rotating speed magnetic sensor with double-redundancy synchronous output, and solves the problem that the output of the original double-redundancy rotating speed magnetic sensor is not synchronous due to asymmetric coil structure. Original dual-redundancy coil is for the inside and outside double-deck coiling of same skeleton upper segment, and this kind of structure is because every turn of coil girth of ectonexine is different, can't guarantee that the resistance and the number of turns of two sets of coils are identical completely, consequently, corresponds same rotational speed signal, and obvious difference will appear in the induced electromotive force of output, causes dual-redundancy output signal to appear asynchronous problem. In the scheme, two rotating speed signal induction coils are designed in the same rotating speed sensing shell, share the framework, the iron core and the magnetic steel, and the two groups of coils are wound in a parallel and synchronous mode, so that the two groups of induction coils can be completely symmetrical, and the rotating speed signals output by the two groups of induction coils can be completely synchronous. When two paths of rotating speed signals are synchronously output, the sensor can be judged to be in a normal working state at the moment; and once a certain path of rotation speed signal has abnormal conditions such as short circuit or open circuit, the other path can still work independently, and the measurement result is accurate.

In order to ensure the signal output intensity of the magnetoelectric rotating speed sensor, the induction coils of the sensor need to be arranged near the circumscribed point area of the convex teeth of the measuring gear, and because of the uniqueness of the tangent point area, two paths of induction coils are determined, the parallel installation structural form cannot be adopted, and the framework, the iron core and the magnetic steel can only be shared. Because two paths of coils are wound in parallel, the number of winding turns is limited, the amplitude of signals output by the rotating speed is low, and the problem of low signal amplitude is more prominent particularly under the working condition of low rotating speed. Therefore, two paths of rotating speed signals need to be effectively amplified so as to meet the requirements of stable and reliable measurement of the rotating speed sensor. The scheme utilizes the amplification effect of the toroidal transformer to carry out secondary amplification on the rotating speed signal, thereby greatly improving the output amplitude of the rotating speed signal under the condition of low rotating speed and meeting the requirement of the lowest output amplitude of the rotating speed signal.

In addition, to ensure the width of the revolution speed sensorThe working characteristics of the range temperature region adopt the following measures. The shell of the rotating speed sensor is made of 316L stainless steel, and the 316L stainless steel has good temperature resistance and the highest working temperature is 600 ℃; an induction coil of the sensor is made of a high-temperature-resistant enameled wire with the diameter of 0.04mm, and the maximum working temperature of the enameled wire can reach 220 ℃; the magnetic steel (permanent magnet) part of the sensor adopts high-temperature resistant neodymium iron boron (Nd)₂Fe₁₄B) And (4) processing to obtain the product. Compared with permanent magnets such as ferrite, alnico, samarium cobalt, platinum cobalt alloy and the like, the neodymium iron boron has the optimal magnetic properties such as remanence, coercive force, maximum energy product remanence and the like within the working temperature range of 200 ℃; the sensor coil framework part is processed by adopting a polyimide material, the material has good high and low temperature resistance test performance and mechanical property, and the working tolerance temperature can be from-200 ℃ to 300 ℃; the sensor core composed of an induction coil of the sensor, magnetic steel (permanent magnet) and the like is filled, encapsulated and filled with high-temperature-resistant epoxy glue, the working temperature of the high-temperature-resistant epoxy glue can be kept at 240 ℃ for a long time, and the tensile shear strength performance at 240 ℃ is good and can still reach more than 5 MPa; the cable sheath of the signal cable of the sensor is made of TPE-thermoplastic polyester elastomer material, the cable sheath of the type has temperature resistance, oil resistance, wear resistance, high elasticity and low-temperature flexibility, the tensile resistance of the signal cable is superior to 200N, and the maximum service temperature can reach 180 ℃; in conclusion, all the components and the whole machine of the rotating speed sensor in the scheme can stably work for a long time in the environment of 180 ℃.

The scheme has the advantages that:

1) the signal output amplitude is high:

according to the scheme, the wire diameter of an enameled wire of the sensor induction coil is improved from 0.05mm to 0.04mm, so that the turn ratio of the coil is increased by about 20% before improvement, and the signal output amplitude of the rotating speed sensor is effectively improved;

in addition, the magnetic steel adopts high-temperature resistant neodymium iron boron (Nd)₂Fe₁₄B) The permanent magnet is made up by strict sintering process, and has the best remanence and coercive force, and its maximum magnetic energy product is superior to that of similar product, and its grade is N52HThe remanence Br reaches 15.6KGs, the coercive force reaches BHc13.8Koe, and the maximum energy product (BH)_MAXCan reach 52.6 Mgoe. Along with the improvement of the magnetic property of the permanent magnet, the signal output amplitude of the sensor is further improved;

2) the magnetic circuit spacing is small:

the sensor coil iron core is manufactured by adopting soft magnet 1J85 permalloy, and the iron core has extremely high magnetic conductivity and extremely low coercive force and is sensitive to weak signal reaction. In order to improve the bundling capability of magnetic lines of force, the iron core adopts a trapezoidal cone design mode, simultaneously, the design of a sensor shell is further optimized, and the thickness of the measuring end surface of the sensor is controlled within 0.15mm, so that the magnetic circuit spacing is effectively shortened;

3) two-stage signal amplification:

referring to fig. 2 and 3, in the scheme, in order to further increase the output amplitude of the rotating speed signal, a secondary amplification loop of the toroidal transformer is designed. Under the condition of low rotating speed, the amplitude of the output signal of the sensor is low, and the amplification effect of the toroidal transformer is utilized to carry out secondary amplification on the rotating speed signal, so that the output amplitude of the rotating speed signal under the condition of low rotating speed can be greatly improved, and the requirement of the lowest output amplitude of the rotating speed signal is met;

4) the sensor has low noise:

in the scheme, in a signal output link, a low-pass filter circuit is designed by means of coil internal resistance and line impedance so as to effectively inhibit high-frequency noise signal interference, improve the signal-to-noise ratio of a rotating speed output signal, ensure the output quality of the rotating speed signal and enhance the anti-electromagnetic interference capability of the sensor;

5) the vibration resistance and the impact resistance are good:

in order to meet the technical requirements of high reliability, vibration resistance and impact resistance, the sensor shell is integrally processed by adopting stainless steel 316L; the signal cable sheath is made of TPE thermoplastic elastomer, and the cable sheath has the advantages of temperature resistance, oil resistance, wear resistance, high elasticity and low-temperature flexibility; the cable adopts a rubber plug sealing and fixing mode to improve the fixing strength and tensile property of the cable and effectively ensure the sealing and protecting performance of the sensor; the induction coil, the magnetic steel, the annular transformer and the like in the shell of the revolution speed transducer are all encapsulated by high-temperature-resistant epoxy resin glue in an integrated manner, so that the whole machine has excellent rigidity strength, and the requirements of vibration resistance and impact protection are met;

6) the sealing protection performance is good:

the scheme is to meet the environmental test requirements of underwater dipping, salt spray and the like, the shell of the sensor is integrally processed and manufactured by selecting a corrosion-resistant and salt spray-resistant 316L stainless steel material without any welding interface; the signal cable sheath is made of TPE thermoplastic elastomer materials, and the signal cable and the shell are sealed and fixed through an oil-resistant and corrosion-resistant fluorine silica gel plug, so that the sensor is guaranteed to have good sealing and protecting performance.