Displacement sensor and displacement acceleration measuring device

Abstract

The utility model relates to a displacement sensor and a displacement acceleration measuring device, and the displacement sensor comprises a primary winding which comprises an excitation line, and an alternating voltage is added to the excitation line of the primary winding, so that the primary winding can generate a magnetic field; the magnetic conductive core can move in the axial direction of the primary winding; the number of the secondary windings is multiple, all the secondary windings are sequentially arranged on the primary winding in the axial direction of the primary winding, each secondary winding comprises a signal line and a common line, the signal lines of all the secondary windings are independently arranged, and the common lines of all the secondary windings are electrically connected; electric signals are transmitted outwards independently through the corresponding signal lines, electric signal changes generated by the secondary windings of the displacement sensor are independently output, errors of the electric signals cannot be accumulated during full-scale measurement, and the measurement precision is improved; the measuring range can be larger than the overall axial length of all the secondary windings, and the measuring range is increased on the premise that the axial length of the secondary windings is fixed.

Description

Technical Field

[0001] The present application belongs to the technical field related to position measurement, and in particular, relates to a displacement sensor and a displacement acceleration measurement device. Background Art

[0002] Displacement sensor, also known as linear sensor, is a sensor that converts the displacement of the measured object into an electrical signal. This type of sensor is developing rapidly and is increasingly used.

[0003] Traditional differential linear displacement sensors usually consist of a primary winding, two secondary windings, a winding frame and an iron core. The primary winding and secondary windings are distributed on the winding frame. The iron core is set inside the winding and can move axially. The two secondary windings are connected in reverse series. The voltage polarities of the two secondary windings are opposite. The output voltage is the difference between the voltages of the two secondary windings. When the iron core is in the middle position, the induced electromotive force generated by the two secondary windings is equal, so the output voltage is zero; when the iron core moves inside the winding and deviates from the center position, the induced electromotive force generated by the two windings is not equal, and there is a voltage output, and the voltage depends on the size of the displacement.

[0004] During the measurement process of the existing displacement sensor, the electrical signal generated will deviate due to changes in the ambient temperature and fluctuations in the power supply voltage, which will inevitably cause measurement errors in the sensor during the measurement process. Since the traditional differential linear displacement sensor can only generate one electrical signal within the full range, the measurement error will increase with the increase of the measurement range, thus causing the accumulation of full-scale errors. The full-scale error accumulation is directly proportional to the measurement range, that is, the larger the measurement range, the greater the full-scale error accumulation, which seriously affects the measurement accuracy of the displacement sensor during operation. Utility Model Content

[0005] In view of this, it is necessary to provide a displacement sensor and a displacement acceleration measuring device for solving the above technical problems.

[0006] A displacement sensor, comprising:

[0007] A primary winding includes an excitation wire, and an alternating voltage can be added to the excitation wire to generate a magnetic field in the primary winding;

[0008] A magnetic core capable of moving along the axial direction of the primary winding;

[0009] A secondary winding is provided in plurality, each of the secondary windings is sequentially arranged on the primary winding along the axial direction of the primary winding, each of the secondary windings comprises a signal line and a common line, the common lines of all the secondary windings are electrically connected, the signal lines of the secondary windings are independently provided, and can independently transmit electrical signals to the outside through the corresponding signal lines;

[0010] It can be understood that when the displacement sensor is working, the changes in the electrical signals generated by each secondary winding generate independent outputs separately. In this way, the electrical signals corresponding to each measurement interval can be measured separately, and the errors of each electrical signal will not be accumulated during full-scale measurement, thereby improving the measurement accuracy of the displacement sensor when it is working; at the same time, under the condition of ADC devices with equal performance and the same measurement range, the displacement sensor improves the overall resolution of the displacement sensor by dividing the full range into several measurement intervals and performing regional analog-to-digital conversion processing on the ADC device; in addition, the measurement range of the displacement sensor can be greater than the overall axial length of all secondary windings. Compared with the traditional differential linear displacement sensor, the measurement range of the displacement sensor is increased under the premise that the axial length of the secondary winding of the sensor is certain.

[0011] In one embodiment, each of the secondary windings corresponds to a measurement interval, and the measurement intervals corresponding to adjacent secondary windings partially overlap;

[0012] It can be understood that in order to achieve consistency in the measurement data output by adjacent secondary windings when the displacement sensor is working, the measurement intervals corresponding to adjacent secondary windings need to be partially overlapped.

[0013] In one embodiment, the displacement sensor further includes a push-pull rod, which extends along the axial direction of the primary winding, is inserted into the primary winding and is connected to the magnetic core, and the magnetic core can move along the axial direction of the primary winding driven by the push-pull rod.

[0014] In one embodiment, the displacement sensor further includes a shell, the shell includes an inner tube, the primary winding is arranged on the inner tube along the axial direction of the inner tube, and the magnetic core can move along the axial direction of the inner tube.

[0015] In one of the embodiments, the shell further includes an end plate and an outer tube, the outer tube is sleeved on the secondary winding, the end plate is located at an end of the outer tube, and the outer tube is connected to the inner tube through the end plate.

[0016] In one embodiment, the excitation wire, the common wire, and the plurality of signal wires may extend outward along the axial direction of the primary winding.

[0017] In one embodiment, the axial length of the secondary winding plus the interval length of the secondary winding on the adjacent side is equal to the axial length of the secondary winding pitch, the axial length of the maximum pitch in the displacement sensor is less than twice the axial length of the minimum pitch, and the axial length of each measuring interval is greater than the axial length of the corresponding secondary winding pitch.

[0018] In one embodiment, the number of turns of each secondary winding can be adjusted;

[0019] It can be understood that the installation area of ​​each secondary winding is divided in sequence along the axial direction of the displacement sensor, and the installation area of ​​each secondary winding corresponds to the corresponding measurement interval, and the number of turns of each secondary winding can be adjusted. In this way, the performance parameters of each secondary winding can be adjusted, and the electrical signal output by each secondary winding can be independently calibrated so that the electrical signal output by each secondary winding corresponds to the position information, thereby adjusting the measurement accuracy of the measurement interval and improving the measurement accuracy of the displacement sensor when it is working.

[0020] In one embodiment, the displacement sensor further comprises a frame, and adjacent secondary windings are separated by the frame;

[0021] It can be understood that the adjacent secondary windings are separated by a skeleton. In this way, when the displacement sensor is produced, the installation area of ​​each secondary winding can be divided axially in advance by the skeleton. This can facilitate the winding and installation of the secondary winding and ensure that the electrical signal is consistent with the position.

[0022] The present application also seeks to protect a displacement acceleration measurement device, comprising a signal conditioner, a signal processor and the above-mentioned displacement sensor, wherein the signal line of each secondary winding can be connected to the signal processor through the signal conditioner.

[0023] Due to the application of the above technical solution, the utility model has the following advantages compared with the prior art:

[0024] 1. The displacement sensor for which protection is sought in the present application has an independent output generated by each electrical signal change generated by each secondary winding, and the electrical signal output by each secondary winding corresponds to the corresponding measurement interval, and the axial position of each secondary winding is fixed, so the electrical signal corresponding to each measurement interval corresponds to the axial position information of the displacement sensor. In this way, the axial position information of the magnetic core in the measurement interval can be obtained by measuring the electrical signal corresponding to each measurement interval separately, thereby determining the axial position information of the magnetic core in the displacement sensor. Therefore, the measurement is not affected by the electrical signal error factors corresponding to other measurement intervals, that is, the errors of each electrical signal will not be accumulated during full-scale measurement, so there is no error accumulation phenomenon, which greatly reduces the measurement deviation caused by error accumulation in the full range, and the electrical signal error generated by each secondary winding can be individually corrected and calibrated, thereby improving the measurement accuracy of the displacement sensor when it is working;

[0025] At the same time, since the traditional differential linear displacement sensor can only generate one electrical signal within the full range, the ADC device can only perform analog-to-digital conversion processing on the full range, so the resolution per unit length will decrease with the increase of the measurement range, that is, the larger the measurement range, the lower the resolution; while for the present displacement sensor, under the condition of ADC devices of the same performance and the same measurement range, by dividing the full range of the displacement sensor into several measurement intervals, each measurement interval outputs an electrical signal separately, and the ADC device performs analog-to-digital conversion processing in different regions, the resolution of each measurement interval can be the same as the resolution of the full range of the traditional differential linear displacement sensor, thereby improving the overall resolution of the present displacement sensor, and each measurement interval can be calibrated separately, further improving the measurement accuracy.

[0026] 2. Due to the measurement principle used, the traditional differential linear displacement sensor requires that the displacement of the iron core is linearly proportional to the output voltage value, and the two secondary windings are connected in series, the voltage polarities of the two secondary windings are opposite, and the output voltage is the difference between the voltages of the two secondary windings. Therefore, when the movement range of the iron core exceeds the axial length range of the sensor secondary winding, the displacement of the iron core and the output voltage value will not be linearly proportional. Specifically, accurate measurement data will not be obtained when the iron core does not completely enter the secondary winding. In order to avoid measurement errors, the range must be less than the axial length of the sensor secondary winding, and in order to obtain better Linear performance, the axial length of the iron core is usually set to one-third of the range, so the actual maximum measurement range is only two-thirds of the axial length of the secondary winding of the sensor; and the magnetic core of the displacement sensor can enter the measurement interval of the secondary winding as a whole from the outside of the winding along the axial direction of the winding for effective measurement, and the axial length of the measurement interval of all secondary windings as a whole is usually slightly larger than the axial length of all secondary windings as a whole, that is, the measurement range can be greater than the axial length of all secondary windings as a whole. Compared with the traditional differential linear displacement sensor, the measurement range of the displacement sensor is increased under the premise that the axial length of the secondary winding of the sensor is certain.

[0027] 3. In order to improve the linearity of the sensor and increase the linear range of the sensor, the traditional differential linear displacement sensor requires the electrical characteristics of the two secondary windings to be strictly symmetrical in order to improve the linearity of the sensor and increase the linear range of the sensor so that the displacement of the iron core is in linear proportion to the output voltage value. Therefore, the manufacturing process of the windings and sensors is very demanding, and the process is more difficult when manufacturing large-range sensors. However, the secondary windings in this displacement sensor are installed in sections on the primary winding, and the axial lengths of the secondary windings can be equal or unequal. Each secondary winding can measure a range independently, and each secondary winding outputs an electrical signal independently. It is sufficient to design the measurement intervals corresponding to adjacent secondary windings to overlap partially. Therefore, the secondary winding has low requirements on the number of turns, winding method, installation and other processes, which reduces the manufacturing difficulty and cost of the windings and displacement sensors. The advantages of this displacement sensor in the manufacture of large-range sensors are more significant.

[0028] 4. The displacement sensor divides the installation area of ​​each secondary winding in sequence along the axial direction. The installation area of ​​each secondary winding corresponds to the corresponding measurement interval, and the number of turns of each secondary winding can be adjusted. In this way, the performance parameters of each secondary winding can be adjusted, and the electrical signal output by each secondary winding can be independently calibrated so that the electrical signal output by each secondary winding corresponds to the position information, thereby adjusting the measurement accuracy of the measurement interval and improving the measurement accuracy of the displacement sensor when it is working.

[0029] 5. This displacement sensor can increase or decrease the number and axial length of secondary windings according to needs, which is convenient for adjusting the parameters of the displacement sensor (parameters include accuracy, range, etc.), and when any secondary winding fails, it will not affect the normal operation of other secondary windings. At the same time, it can also quickly determine the fault location, which is convenient for maintenance. Since each secondary winding works independently, only one faulty secondary winding needs to be replaced, and there is no need to replace all secondary windings.

[0030] 6. The displacement acceleration measuring device can also calculate the displacement data of the measured object according to the change of the electrical signal output by the displacement sensor, and calculate the acceleration of the measured object during movement according to the change of the displacement data, thereby realizing the measurement of the acceleration of the measured object. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A schematic diagram of the structure of a displacement sensor provided in one embodiment of the present application;

[0033] Figure 2 for Figure 1 Electrical schematic diagram of the medium-conducting core, primary winding and multiple secondary windings;

[0034] Figure 3 This is a working principle diagram of a displacement acceleration measurement device provided in one embodiment of the present application.

[0035] Figure numerals: 100, displacement sensor; 10, shell; 11, inner tube; 12, outer tube; 13, end plate; 20, magnetic core; 21, push-pull rod; 30, primary winding; 40, secondary winding; 41, signal line; 50, skeleton; 200, signal conditioner; 300, signal processor. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0037] It should be noted that when an element is referred to as being "provided on" another element, it may be directly provided on the other element or there may be a central element. When an element is considered to be "provided on" another element, it may be directly provided on the other element or there may be a central element at the same time. When an element is considered to be "fixed to" another element, it may be directly fixed to the other element or there may be a central element at the same time.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] The displacement sensor 100 for which protection is sought in the present application is used to measure the axial position of the magnetic core 20 relative to the winding, thereby achieving position measurement of a target (not shown) connected to the magnetic core 20 when it moves.

[0040] like Figure 1 , Figure 2 As shown, a displacement sensor 100 provided in an embodiment of the present application includes a magnetic core 20, a primary winding 30 and a secondary winding 40. The primary winding 30 includes an excitation wire, and an alternating voltage can be added to the excitation wire to generate a magnetic field in the primary winding 30. The magnetic core 20 can move along the axial direction of the primary winding 30. A plurality of secondary windings 40 are provided, and each of the secondary windings 40 is sequentially arranged on the primary winding 30 along the axial direction of the primary winding 30. Each of the secondary windings 40 includes a signal line 41 and a common line. The common lines of all the secondary windings 40 are electrically connected. The signal lines 41 of each of the secondary windings 40 are independently provided, and can independently transmit electrical signals to the outside through the corresponding signal lines 41.

[0041] Here, the structure of the primary winding 30 includes a solenoid, a hollow coil, etc., and the structure of the secondary winding 40 includes a solenoid, a hollow coil, etc. The solenoid wall has a high hardness and is not easy to deform. After the solenoid is formed, it can be used without being wound on a tubular object. The secondary winding 40 can be assembled in the displacement sensor 100 with the primary winding 30 as the installation basis; the magnetic core 20 is made of a material with high magnetic permeability, such as iron, cobalt, nickel and their alloys.

[0042] When working, an alternating voltage is added to the excitation line of the primary winding 30, so that the primary winding 30 generates a magnetic field and each secondary winding 40 generates an initial induced electromotive force independently, and can independently transmit electrical signals to the outside through the corresponding signal line 41;

[0043] When the magnetic core 20 approaches the two ends of the winding from the outside of the winding or enters the winding or moves in the winding, the position of the spatial magnetic field intensity distribution in the axial direction will also move with the magnetic core 20, and the magnetic field intensity in the area around the magnetic core 20 will increase. The area where the magnetic field intensity increases formed by the magnetic core 20 is called a strong magnetic area. The magnetic field intensity distribution in the strong magnetic area is stronger in the middle than at the two ends. As the strong magnetic area gradually enters the secondary winding 40, the voltage value of the induced electromotive force generated by the secondary winding 40 will gradually increase.

[0044] When the magnetic core 20 enters from one end of any secondary winding 40 along the axial direction of the winding and then leaves from the other end through the secondary winding 40, the strong magnetic region moves with the magnetic core 20 during this process, causing the voltage value of the induced electromotive force generated by the secondary winding 40 to increase from the initial voltage value to the maximum voltage value and then decrease to the initial voltage value.

[0045] During calibration, the magnetic core 20 moves from the left end of the winding to the right along the axial direction of the winding, and the strong magnetic area formed by the magnetic core 20 will move toward the left end of the secondary winding 40 accordingly, and the strong magnetic area at the right end of the magnetic core 20 will approach the left end of the secondary winding 40, so that the voltage value of the induced electromotive force generated by the secondary winding 40 gradually increases from the initial voltage value. When the distance between the right end of the magnetic core 20 and the corresponding left end of the secondary winding 40 is reduced to a preset value, the voltage value of the induced electromotive force generated by the corresponding secondary winding 40 is the effective minimum voltage value when the magnetic core 20 moves to the right, and the axial distance between the right end of the magnetic core 20 and the corresponding left end of the secondary winding 40 is the effective strong magnetic area length of the right end.

[0046] The magnetic core 20 moves from the right end of the winding to the left along the axial direction of the winding, and the strong magnetic area formed by the magnetic core 20 will move toward the right end of the secondary winding 40 accordingly, and the strong magnetic area at the left end of the magnetic core 20 will approach the right end of the secondary winding 40, so that the voltage value of the induced electromotive force generated by the secondary winding 40 gradually increases from the initial voltage value. When the distance between the left end of the magnetic core 20 and the corresponding right end of the secondary winding 40 is reduced to a preset value, the voltage value of the induced electromotive force generated by the corresponding secondary winding 40 is the effective minimum voltage value when the magnetic core 20 moves to the left, and the axial distance between the left end of the magnetic core 20 and the corresponding right end of the secondary winding 40 is the length of the effective strong magnetic area at the left end.

[0047] The axial length of the magnetic core 20 plus the length of the effective strong magnetic zone at the right end and the length of the effective strong magnetic zone at the left end equals the length of the effective strong magnetic zone formed by the magnetic core 20;

[0048] When the magnetic core 20 moves along the axial direction of the winding, the strong magnetic area will move accordingly. The effective strong magnetic area causes the voltage value of the induced electromotive force generated by the corresponding secondary winding 40 to increase from the effective minimum voltage value to the maximum voltage value or decrease from the maximum voltage value to the effective minimum voltage value. The axial displacement interval of the magnetic core 20 corresponding to the voltage value change interval of this induced electromotive force is called the measurement interval of the corresponding secondary winding 40. The axial displacement distance of the magnetic core 20 is equal to the axial length of the measurement interval of the secondary winding 40.

[0049] In order to achieve the continuity of the measurement data output by adjacent secondary windings 40 when the displacement sensor 100 is working, each of the secondary windings 40 corresponds to a measurement interval, and the measurement intervals corresponding to adjacent secondary windings 40 partially overlap, that is, the measurement intervals of adjacent secondary windings 40 correspond to the axial displacement intervals of the magnetic core 20 partially overlap. Specifically, the magnetic core 20 moves from the left end of the winding to the right along the axial direction of the winding. As the effective strong magnetic zone at the right end of the magnetic core 20 gradually enters the first secondary winding 40 on the left, the induced electromotive force generated by the first secondary winding 40 on the left gradually increases from the effective minimum voltage value. As the magnetic core 20 continues to move to the right, before the induced electromotive force generated by the first secondary winding 40 on the left increases to the maximum voltage value, the magnetic core 20 The effective strong magnetic zone at the right end of the magnetic core 20 enters the second secondary winding 40 on the left. At this time, the induced electromotive force generated by the second secondary winding 40 on the left gradually increases from the effective minimum voltage value. Similarly, as the magnetic core 20 continues to move to the right, before the induced electromotive force generated by the second secondary winding 40 on the left increases to the maximum voltage value, the effective strong magnetic zone at the right end of the magnetic core 20 enters the third secondary winding 40 on the left. At this time, the induced electromotive force generated by the third secondary winding 40 on the left gradually increases from the effective minimum voltage value, and so on; when the magnetic core 20 moves from the right end of the winding to the left along the axial direction of the winding, the working direction is opposite, and the working principle is understood as described above; thereby, the axial position information of the magnetic core 20 in the displacement sensor 100 can be obtained according to the voltage value of the induced electromotive force in each measuring interval.

[0050] It can be understood that the changes in the electrical signals generated by each secondary winding 40 generate independent outputs separately, and the electrical signals output by each secondary winding 40 correspond to the corresponding measurement intervals, and the axial positions of each secondary winding 40 are fixed, so the electrical signals corresponding to each measurement interval correspond to the axial position information of the displacement sensor 100. In this way, the axial position information of the magnetic core 20 in the measurement interval can be obtained by measuring the electrical signals corresponding to each measurement interval separately, so as to determine the axial position information of the magnetic core 20 in the displacement sensor 100. Therefore, the measurement is not affected by the error factors of the electrical signals corresponding to other measurement intervals, that is, the errors of the electrical signals will not be accumulated during full-scale measurement, so there is no error accumulation phenomenon, which greatly reduces the measurement deviation caused by error accumulation in the full range, and the electrical signal errors generated by each secondary winding 40 can be individually corrected and calibrated, thereby improving the measurement accuracy of the displacement sensor 100 when it is working;

[0051] At the same time, since the traditional differential linear displacement sensor can only generate one electrical signal within the full range, the ADC device can only perform analog-to-digital conversion processing on the full range, so the resolution per unit length will decrease as the measurement range increases, that is, the larger the measurement range, the lower the resolution; while the displacement sensor 100, under the condition of ADC devices of equal performance and the same measurement range, divides the full range of the displacement sensor 100 into several measurement intervals, each measurement interval outputs an electrical signal separately, and the ADC device performs regional analog-to-digital conversion processing, so that the resolution of each measurement interval can be the same as the resolution of the full range of the traditional differential linear displacement sensor, thereby improving the overall resolution of the displacement sensor 100, and each measurement interval can be calibrated separately, further improving the measurement accuracy.

[0052] In addition, the measuring range of the displacement sensor 100 can be greater than the axial length of all the secondary windings 40 as a whole, and the measuring range of the displacement sensor 100 is increased when the axial length of the secondary windings 40 as a whole is constant; it should be noted that all the secondary windings 40 in the displacement sensor 100 are regarded as a whole, and the measuring interval of all the secondary windings 40 as a whole is equal to the measuring range of the displacement sensor 100, and the axial length of the measuring interval of all the secondary windings 40 as a whole is usually slightly greater than the axial length of all the secondary windings 40 as a whole;

[0053] When the magnetic core 20 gradually enters the measurement interval corresponding to the first left or right secondary winding 40 of the displacement sensor 100 from outside the winding along the axial direction of the winding, the induced electromotive force of the first left or right secondary winding 40 gradually increases from the effective minimum voltage value, and the induced electromotive force of the second left or right secondary winding 40 will not reach the effective minimum voltage value when the magnetic core 20 does not enter the measurement interval corresponding to the second left or right secondary winding 40, so it can be known that the magnetic core 20 enters from outside the winding and from which end it enters;

[0054] In this way, by utilizing the above-mentioned characteristic, the magnetic core 20 can enter the measuring range of the entire secondary winding 40 from the outside of the winding along the axial direction of the winding to perform effective measurement, that is, the measuring range can be greater than the axial length of all the secondary windings 40 as a whole. Compared with the traditional differential linear displacement sensor, the measuring range of the displacement sensor 100 is increased under the premise that the axial length of the secondary winding of the sensor is certain; it should be explained here that the traditional differential linear displacement sensor requires that the displacement of the iron core is in linear proportion to the output voltage value due to the measurement principle used, and the two secondary windings are connected in series. The voltage polarities of the windings are opposite, and the output voltage is the difference between the voltages of the two secondary windings. Therefore, when the movement range of the core exceeds the axial length range of the sensor's secondary winding, the displacement of the core and the output voltage value will not be linearly proportional. Specifically, accurate measurement data will not be obtained when the core has not completely entered the secondary winding. In order to avoid measurement errors, the range must be smaller than the axial length of the sensor's secondary winding, and in order to obtain better linear performance, the axial length of the core is usually set to one-third of the range, so the actual maximum measurement range is only two-thirds of the axial length of the sensor's secondary winding.

[0055] like Figure 1 As shown, in some embodiments, the displacement sensor 100 also includes a push-pull rod 21, which extends along the axial direction of the primary winding 30 and is inserted into the primary winding 30 and connected to the magnetic core 20, and the magnetic core 20 can move along the axial direction of the primary winding 30 driven by the push-pull rod 21; that is, the magnetic core 20 in the displacement sensor 100 is specifically connected to the target object by the push-pull rod 21, so that the target object can drive the magnetic core 20 to move along the axial direction of the primary winding 30 through the push-pull rod 21 while moving; the push-pull rod 21 is preferably made of a material with low magnetic permeability, including metals and alloys other than iron, cobalt, nickel and their alloys, and non-metals and other materials with low magnetic susceptibility, such as: aluminum, plastic, etc.

[0056] like Figure 1As shown, in some embodiments, the displacement sensor 100 also includes a shell 10, the shell 10 includes an inner tube 11, the primary winding 30 is arranged on the inner tube 11 along the axial direction of the inner tube 11, and the magnetic core 20 can move along the axial direction of the inner tube 11; that is, the coil formed by the solenoid or wire of the primary winding 30 can be installed in the displacement sensor 100 with the inner tube 11 of the shell 10 as the installation base; the inner tube 11 is made of a material with low magnetic permeability, including metals and alloys other than iron, cobalt, nickel and their alloys and non-metals with low magnetic susceptibility, such as: aluminum, plastic, etc.

[0057] In this embodiment, the shell 10 further includes an end plate 13 and an outer tube 12 . The outer tube 12 is sleeved on the secondary winding 40 . The end plate 13 is located at the end of the outer tube 12 . The outer tube 12 is connected to the inner tube 11 through the end plate 13 .

[0058] like Figure 1 , Figure 2 As shown, in some embodiments, the excitation wire, the common wire and the plurality of signal wires 41 may extend outward along the axial direction of the primary winding 30. In this way, it is convenient to collect and process the electrical signals respectively transmitted by the plurality of signal wires 41.

[0059] It should be noted that the common lines of all secondary windings 40 in the displacement sensor 100 are electrically connected, so that when the displacement sensor 100 is working, all secondary windings 40 can share a common line, thus meeting the working requirements of the displacement sensor 100.

[0060] like Figure 1 , Figure 2 As shown, in some embodiments, the axial length of the secondary winding 40 plus the interval length of the secondary winding 40 on the adjacent side is equal to the axial length of the pitch of the secondary winding 40, the axial length of the maximum pitch in the displacement sensor 100 is less than twice the axial length of the minimum pitch, and the axial length of each measuring interval is greater than the axial length of the corresponding pitch of the secondary winding 40.

[0061] In some embodiments, there is no gap between the secondary windings 40 and the axial lengths of the secondary windings 40 are equal. In order to achieve the continuity of the measurement data output by the adjacent secondary windings 40 when the displacement sensor 100 is working, the measurement intervals corresponding to the adjacent secondary windings 40 need to partially overlap, so the following conditions need to be met: the length of the effective strong magnetic area is greater than the axial length of the secondary winding 40, and the axial length of the measurement interval of the secondary winding 40 is greater than the axial length of the secondary winding 40;

[0062] In actual use, there are intervals between the secondary windings 40, and the axial lengths of the secondary windings 40 are equal. The axial length of the secondary winding 40 plus the interval length of the secondary winding 40 on the adjacent side is equal to the axial length of the pitch of the secondary winding 40. The axial length of the pitch of the secondary winding 40 is set to L, the effective strong magnetic zone length is set to C, and the axial length of the measuring interval of the secondary winding 40 is set to S. In order to achieve the continuity of the measurement data output by the adjacent secondary windings 40 when the displacement sensor 100 is working, the following conditions need to be met: C>L, S>L; if 2L>C>L is set, space can be saved and space utilization can be improved.

[0063] In actual use, there are gaps between the secondary windings 40, and the axial lengths of the secondary windings 40 are not equal. Assuming the axial length of the maximum pitch is Lmax, and the axial length of the minimum pitch is Lmin, in order to achieve the continuity of the measurement data output by adjacent secondary windings 40 when the displacement sensor 100 is working, the following conditions need to be met: 2Lmin>Lmax, C>Lmax, the axial length of each measurement interval is greater than the axial length of the corresponding secondary winding 40 pitch; if 2Lmin>C>Lmax is set, space can be saved and space utilization can be improved.

[0064] In practical applications of the displacement sensor 100 , based on the above principle, preferably, the axial length of the magnetic core 20 can be set to T, wherein 2Lmin>Lmax, T>Lmax; if 2Lmin>T>Lmax is set, space can be saved and space utilization can be improved.

[0065] like Figure 1 , Figure 2 As shown, in some embodiments, the number of turns of each secondary winding 40 can be adjusted; it can be understood that the installation area of ​​each secondary winding 40 is divided in sequence along the axial direction of the displacement sensor 100, and the installation area of ​​each secondary winding 40 corresponds to the corresponding measurement interval, and the number of turns of each secondary winding 40 can be adjusted. In this way, the performance parameters of each secondary winding 40 can be adjusted, and the electrical signal output by each secondary winding 40 can be independently calibrated, so that the electrical signal output by each secondary winding 40 corresponds to the position information, thereby adjusting the measurement accuracy of the measurement interval and improving the measurement accuracy of the displacement sensor 100 when it is working.

[0066] It should be noted that the traditional differential linear displacement sensor requires that the displacement of the core is linearly proportional to the output voltage value due to the measurement principle used, and the two secondary windings are connected in series, the voltage polarities of the two secondary windings are opposite, and the output voltage is the difference between the voltages of the two secondary windings. In order to improve the linearity of the sensor and increase the linear range of the sensor, the displacement of the core is linearly proportional to the output voltage value. Therefore, the electrical characteristics of the two secondary windings are required to be strictly symmetrical, so the manufacturing process of the windings and sensors is very demanding, and the process difficulty is even greater when manufacturing large-range sensors. Large; and each secondary winding 40 in the displacement sensor 100 is installed in sections on the primary winding 30, the axial lengths of each secondary winding 40 may be equal or unequal, each secondary winding 40 can measure a range independently, and each secondary winding 40 outputs an electrical signal independently, as long as the measurement intervals corresponding to adjacent secondary windings 40 are designed to overlap partially, so the secondary winding 40 has low requirements on the number of turns, winding method, installation and other processes, which reduces the manufacturing difficulty and cost of the winding and the displacement sensor 100, and the advantages of the displacement sensor 100 in the manufacture of large-range sensors are more significant.

[0067] In some embodiments, the displacement sensor 100 can increase or decrease the number and axial length of the secondary windings 40 as needed, so as to facilitate adjustment of the parameters of the displacement sensor 100 (the parameters include accuracy, range, etc.), and when any secondary winding 40 fails, it will not affect the normal operation of other secondary windings 40, and the fault location can be quickly determined, which is convenient for maintenance. Since each secondary winding 40 works independently, only one faulty secondary winding 40 needs to be replaced, without replacing all secondary windings 40.

[0068] like Figure 1 As shown, in some embodiments, the displacement sensor 100 further includes a skeleton 50, and adjacent secondary windings 40 are separated by the skeleton 50; that is, when the displacement sensor 100 is produced, the skeleton 50 can be used in advance to divide the displacement sensor 100 axially into installation areas of each secondary winding 40, which can facilitate the winding and installation of the secondary winding 40 and ensure that the electrical signal is consistent with the position.

[0069] In addition, if Figure 3As shown, the present application also provides a displacement acceleration measurement device, including a signal conditioner 200, a signal processor 300 and the above-mentioned displacement sensor 100, and the signal line 41 of each secondary winding 40 can be connected to the signal processor 300 through the signal conditioner 200. The electrical signal of each secondary winding 40 can be transmitted to the signal conditioner 200 through the signal line 41, and transmitted to the signal processor 300 after being processed by the signal conditioner 200. By processing the electrical signal transmitted by the secondary winding 40 by the signal processor 300, the axial position information of the magnetic core 20 in the displacement sensor 100 can be calculated, and the acceleration information of the magnetic core 20 when it moves relative to the axial direction of the winding can be obtained.

[0070] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. As long as they are within the spirit of the present invention, appropriate changes and modifications to the above embodiments are within the scope of protection required by the present invention.

Claims

1. A displacement sensor, characterized in that: The displacement sensor (100) comprises: The primary winding (30) comprises an excitation wire, and an alternating voltage can be added to the excitation wire to make the primary winding (30) generate a magnetic field; A magnetically conductive core (20) capable of moving along the axial direction of the primary winding (30); The secondary winding (40) is provided in plurality, each of the secondary windings (40) being arranged on the primary winding (30) in sequence along the axial direction of the primary winding (30), each of the secondary windings (40) comprising a signal line (41) and a common line, the common lines of all the secondary windings (40) being electrically connected, the signal lines (41) of the secondary windings (40) being independently provided, and being capable of independently transmitting electrical signals to the outside through the corresponding signal lines (41).

2. The displacement sensor according to claim 1, characterized in that: Each of the secondary windings (40) corresponds to a measurement interval, and the measurement intervals corresponding to adjacent secondary windings (40) partially overlap.

3. The displacement sensor according to claim 1, characterized in that: The displacement sensor (100) further comprises a push-pull rod (21), wherein the push-pull rod (21) extends along the axial direction of the primary winding (30), is inserted into the primary winding (30) and is connected to the magnetic core (20), and the magnetic core (20) is capable of moving along the axial direction of the primary winding (30) driven by the push-pull rod (21).

4. The displacement sensor according to claim 1, characterized in that: The displacement sensor (100) further comprises a housing (10), the housing (10) comprising an inner tube (11), the primary winding (30) being arranged on the inner tube (11) along the axial direction of the inner tube (11), and the magnetic core (20) being movable along the axial direction of the inner tube (11).

5. The displacement sensor according to claim 4, characterized in that: The shell (10) further comprises an end plate (13) and an outer tube (12); the outer tube (12) is sleeved on the secondary winding (40); the end plate (13) is located at the end of the outer tube (12); and the outer tube (12) is connected to the inner tube (11) via the end plate (13).

6. The displacement sensor according to claim 1, characterized in that: The excitation wire, the common wire, and the plurality of signal wires (41) can extend outward along the axial direction of the primary winding (30).

7. The displacement sensor according to claim 2, characterized in that: The axial length of the secondary winding (40) plus the interval length of the secondary winding (40) on the adjacent side is equal to the axial length of the pitch of the secondary winding (40); the axial length of the maximum pitch in the displacement sensor (100) is less than twice the axial length of the minimum pitch; and the axial length of each measurement interval is greater than the axial length of the corresponding pitch of the secondary winding (40).

8. The displacement sensor according to claim 1, characterized in that: The number of turns of each secondary winding (40) can be adjusted.

9. The displacement sensor according to claim 1, characterized in that: The displacement sensor (100) further comprises a skeleton (50), and adjacent secondary windings (40) are separated by the skeleton (50).

10. A displacement acceleration measuring device, characterized in that: A displacement sensor (100) comprising a signal conditioner (200), a signal processor (300) and any one of claims 1 to 9, wherein the signal line (41) of each secondary winding (40) can be connected to the signal processor (300) via the signal conditioner (200).

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