Inductive linear position detection sensor
Through the electromagnetic coupling principle and ring-shaped rotor design of inductive linear position detection sensor, the problem of reduced position detection accuracy in the prior art is solved, high-precision detection in vibration and rotation environments is achieved, and resistance is improved through the protective case Receptive.
Patent Information
- Application Number
- CN202411517048.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-29
- Publication Date
- 2024-12-20
AI Technical Summary
The accuracy of existing position detection sensors decreases in vibration and impact environments, and there are differences in mechanical wave propagation of magnetostrictive sensors, resulting in loss of position measurement accuracy and difficult to accurately detect under rotation.
The inductive linear position detection sensor is adopted to generate and induce electromagnetic fields through the electromagnetic coupling principle between the ring rotor and the stator to generate an induced current. It is used to directly measure linear displacement, avoiding the hysteresis and accuracy reduction of mechanical wave transmission, and through protection Shell isolates environmental pollution.
High-precision linear displacement detection in vibration and rotation environments is achieved, reducing hysteresis and accuracy reduction, and improving sensor tolerance and measurement stability.
Smart Images
Figure CN119164278A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to a position detection sensor, in particular to an inductive linear position detection sensor. Background Art
[0002] In the current working environment of heavy industry, there are usually large vibrations and shocks; there are large amounts of water, gasoline, gas and dust, etc.; there is large movement during the displacement of the mover and stator, that is, in addition to the displacement of the moving axis, there are also displacements or rotations of other axes; the ambient temperature difference is large, and there are continuous high or low temperatures. At present, indirect solutions are usually adopted, such as adding a bearing outside the rotating body of the sensor to separate the rotational motion, and connecting the sensing component or the sensed component on the other side of the bearing. This component is not affected by the rotation and only moves in a straight line, so it can be measured using conventional means. However, this idea of separating the rotational motion causes great design inconvenience.
[0003] In addition, the existing position detection sensors used in the above environment are mainly magnetostrictive displacement sensors, which transmit position signals through mechanical wave signals generated by the deformation of the waveguide wire under the action of the electromagnetic field. However, since the magnetic ring used to provide an electromagnetic field parallel to the axis of the waveguide wire has a certain thickness, and the electromagnetic field intensity and direction generated under different temperatures and relative position changes with the waveguide wire will have certain differences, the position of the superimposed electromagnetic field will change, and the measurement accuracy will be lost to a certain extent. In addition, due to differences in the processing technology of the waveguide wire, the external temperature difference and the physical properties of the waveguide wire, the mechanical wave propagation speed will also be different, and the final position accuracy will also have deviations. Moreover, as the propagation distance of the mechanical wave in the waveguide wire increases, the energy is also decreasing. After a certain distance, the torsional deformation is not enough to cause the receiving coil to be inductive, and the travel will be limited. Summary of the invention
[0004] In order to solve the problems caused by the above-mentioned working environment and the existing mechanical wave detection principle, the present application proposes an inductive linear position detection sensor, comprising: a stator, including an electromagnetic induction unit, a protective shell and an information processing unit, wherein the electromagnetic induction unit and the information processing unit are arranged in the protective shell; an annular mover, the surface of the annular mover is provided with induction protrusions, the induction protrusions are metal induction protrusions arranged alternately, and the longitudinal direction of the stator is parallel to the central axis direction of the annular mover; wherein the stator is used to generate an excitation signal to generate a first electromagnetic field, when the annular mover moves along the central axis direction, the first electromagnetic field causes the annular mover to generate a second electromagnetic field, and the first electromagnetic field and the second electromagnetic field cause the electromagnetic induction unit to generate an induced current.
[0005] Optionally, the stator is arranged inside the annular mover.
[0006] Optionally, the inner diameter of the annular mover is greater than the outer diameter of the stator.
[0007] Optionally, the inner surface of the annular mover is provided with a sensing protrusion.
[0008] Optionally, the stator is arranged on a side of the annular mover.
[0009] Optionally, the outer surface of the annular mover is provided with a sensing protrusion.
[0010] Optionally, the stator and / or the annular mover may be made of a flexible material.
[0011] This position detection sensor is mainly used for direct measurement of the linear displacement of rotating or swinging objects, such as the position detection of the movable mold during the mold closing process on the injection molding machine; for example, the detection of the piston position in the hydraulic cylinder during the extension and contraction of the hydraulic cylinder; for example, in the metal machining industry, especially on the downward pressing tool of the punching machine, it is used for the position detection of the tool head. The above-mentioned inductive linear position detection sensor uses the principle of electromagnetic coupling to break through the limitations of magnetostriction of existing sensors, and does not need to rely on time measurement, further avoiding the decrease in accuracy caused by hysteresis, and the design of the mover into a ring ensures that accurate detection can still be performed when the mover rotates. In addition, the use of a protective shell isolates the sensor from pollutants in the working environment, effectively improving the sensor's tolerance to the working environment without affecting the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a schematic diagram of the structure of an inductive linear position detection sensor according to an embodiment of the present application.
[0013] Figure 2 It is a schematic diagram of an application scenario of an inductive linear position detection sensor according to an embodiment of the present application.
[0014] Figure 3 It is a schematic diagram of the working principle of the inductive linear position detection sensor according to the implementation mode of the present application.
[0015] Figure 4 It is a schematic diagram of the structure of an inductive linear position detection sensor according to an embodiment of the present application.
[0016] Figure 5 It is a schematic diagram of an application scenario of an inductive linear position detection sensor according to an embodiment of the present application. DETAILED DESCRIPTION
[0017] The present application is described in detail below with reference to the accompanying drawings and specific implementation methods.
[0018] Embodiment 1
[0019] First reference Figure 1 The structure of the inductive linear position detection sensor proposed in the present application is described. In this embodiment, the sensor includes two parts: an annular mover 10 and a stator 11. An inductive protrusion 101 is provided on the outer surface of the annular mover 10, that is, metal inductive protrusions are alternately provided on the outer surface of the annular mover 10, which are used to generate a changing electromagnetic field when the mover is displaced. When the movement occurs, the annular structure allows the two sides of the mover that is moving to compensate each other, so that the equivalent electromagnetic induction generated by the mover as a whole remains unchanged, which well solves the influence of the movement of the mover on the measurement result when the mover moves with the measured object. The stator 11 includes a circuit board 111, a protective shell 112 and a protective shell cover 113, wherein the circuit board 111 is integrated with an electromagnetic induction unit (such as an induction coil) and an information processing unit, and the circuit board is placed in the protective shell 112 and the protective shell cover 113 to isolate the environmental influence. An electrical connection is also provided at one end of the protective shell 112 for powering the sensor. It can be understood that the protective shell is only used to isolate pollutants such as dust, oil and water in the environment without affecting the electromagnetic induction effect.
[0020] Figure 2 Figure 1 is a schematic diagram of an exemplary application scenario of the sensor. Figure 2 As shown, in this embodiment, the sensor is arranged in the injection molding machine to detect the position of the injection molding machine spindle. Specifically, the annular mover 21 of the sensor is arranged at the moving end of the injection molding machine spindle 22, and the ring center of the annular mover 21 is preferably arranged concentrically with the axis center of the injection molding machine spindle 22 to avoid the influence of movement. The sensor stator 23 is preferably arranged so that its longitudinal direction is parallel to the longitudinal direction of the injection molding machine spindle 22, that is, the longitudinal direction of the stator 23 is parallel to the central axis of the annular mover 21. When the injection molding machine spindle is displaced, the annular mover 21 can be driven to displace synchronously, thereby generating a corresponding induced current on the stator 23, and the induced current is converted into position information through the information processing unit of the stator 23. It can be understood that since the stator 23 is arranged on the outside of the ring of the annular mover 21, it is only necessary to set an induction protrusion on the outer surface of the annular mover to generate the corresponding electromagnetic induction.
[0021] Next reference Figure 3The electromagnetic induction signal transmission schematic diagram shown in the figure explains the working principle of the sensor. The electromagnetic induction unit in the stator generates an excitation signal, which is used to generate an alternating electromagnetic field, namely the first electromagnetic field. Due to the electromagnetic induction effect, under the action of the first electromagnetic field, a corresponding induced electromagnetic field, namely the second electromagnetic field, is generated on the mover. When the mover moves along a straight line with the object to be measured, the electromagnetic induction unit generates an induced current under the joint action of the changing first electromagnetic field and the second electromagnetic field (i.e., the superimposed electromagnetic field), and transmits the induced current to the signal processing unit to convert the induced current into corresponding position information.
[0022] In this implementation, the sensor is based on the principle of electromagnetic coupling and does not rely on time difference and mechanical wave transmission to measure position, which can greatly reduce hysteresis and reduce the accuracy loss caused by individual differences in materials and external ambient temperature; the amplitude of the mechanical wave will gradually decrease with the increase of propagation distance, and the electromagnetic induction principle can be used to complete long-stroke position detection; the mover is designed to be ring-shaped, and stable detection can still be performed when the mover rotates.
[0023] Embodiment 2
[0024] In addition, for different application scenarios, this application also proposes another inductive linear position detection sensor, which is as follows: Figure 4 As shown. The sensor includes an annular mover 40 and a stator 41. Among them, the inner diameter of the annular mover 40 is larger than the outer diameter of the stator 41, so that the stator 40 can be set inside the ring of the annular mover 40. Sensing protrusions 401 are arranged on the inner surface of the annular mover 40, that is, metal sensing protrusions are alternately arranged on the inner surface of the annular mover 40, which are used to generate a changing electromagnetic field when the mover is displaced. When the movement occurs, the annular structure allows the two sides of the mover that has moved to compensate each other, so that the equivalent electromagnetic induction generated by the mover as a whole remains unchanged, which effectively solves the influence of the movement of the mover on the measurement result when the mover moves with the object to be measured. The stator 41 includes a sensing circuit board 411, a protective shell 412, an electronic compartment 413 and an information processing circuit board 414, wherein the sensing circuit board 411 is arranged in the protective shell 412, and is sealed by a protective shell cover 4121 to isolate pollution in the environment, and facilitate the installation and disassembly of the sensing circuit board 411. As shown Figure 4As shown, the sensing circuit board 411 is preferably annular, but it is understandable that due to the annular structure of the annular mover 40, the sensing circuit board can also be a flat rectangular shape. The protective shell 412 is only used to isolate pollutants such as dust, oil and water in the environment without affecting the electromagnetic induction effect. The electronic compartment 413 is connected to the protective shell 412 through a sealing ring 4122 to isolate pollution. The information processing circuit board 414 is arranged in the electronic compartment 413, electrically connected to the sensing circuit board 411, and sealed by the electronic compartment cover 4131. An electrical connection is provided on the electronic compartment cover 4131 for powering the sensor. Among them, the cylindrical protective shell can be used for placement inside the piston for measurement. In other embodiments, it can also be designed into other shapes. It can be understood that the above structure is only used as an example, and the stator structure described in Example 1 can also be used to integrate the sensing circuit board and the information processing circuit board and place them in the protective shell without providing an electronic compartment and its accessories.
[0025] Next, the application scenario of the sensor described in the second embodiment is described. Figure 5 Is set with Figure 4 A cross-sectional view of the piston of the sensor described. Figure 5 As shown, in this embodiment, the annular mover 51 is arranged on the piston 52, and the stator is fixedly connected to the piston cylinder 53, wherein the electronic compartment 54 of the stator is arranged at the end of the piston cylinder, and the protective shell 55 extends to the inside of the piston cylinder for position detection, and the inside of the protective shell 55 is provided with a sensing circuit board 56, and the position and length of the sensing circuit board are set to cover the moving range of the piston 52. The annular mover 51 surrounds the protective shell 54, and when the piston rod 57 drives the piston 52 to move, the annular mover 51 connected to the piston 52 also moves accordingly, thereby generating a corresponding induced current on the sensing circuit board 56. It can be understood that based on the above application scenario, the sensing protrusion is arranged on the inner surface of the annular mover to generate the corresponding electromagnetic induction. In addition, due to the annular structure of the annular mover 51, as long as the longitudinal direction of the sensing circuit board 56 is parallel to the central axis of the annular mover 51, the influence of the movement during the measurement process on the measurement result can be avoided. It can be understood that the electromagnetic signal transmission of the sensor in the second embodiment is the same as that in the first embodiment.
[0026] In this embodiment, the sensor is based on the principle of electromagnetic coupling, and does not rely on time difference and mechanical wave transmission to measure position, which greatly reduces hysteresis and reduces the accuracy loss caused by individual differences in materials and external ambient temperature; the amplitude of the mechanical wave will gradually decrease with the increase of propagation distance, and the electromagnetic induction principle can be used to complete long-stroke position detection; the mover is designed to be ring-shaped, and stable detection can still be performed when the mover rotates; the central stator solution is smaller in size and can be directly inserted into the hydraulic cylinder for detection.
[0027] In addition, for the above-mentioned embodiment 1 and embodiment 2, the mover can also be designed as a flexible circuit board or a flexible metal strip, which can be directly attached to the curved surface of the device under test. Similarly, the circuit board in the stator can also be designed as a flexible circuit board. Through flexible design, the detection sensor can be made more versatile and can be freely adjusted according to the size and structure of the device under test to meet more application scenarios.
[0028] The above specific embodiments illustrate the implementation of the present application, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Although the description of the present application will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to the implementation. In addition, in order to avoid confusion or blurring the focus of the present application, some specific details will be omitted in the description. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.
[0029] Furthermore, various operations will be described as multiple discrete operations in a manner that is most helpful for understanding the illustrative embodiments; however, the order of description should not be construed as implying that these operations are necessarily order dependent. In particular, these operations do not need to be performed in the order presented.
[0030] Unless the context dictates otherwise, the terms "comprising," "having," and "including" are synonymous. The phrase "A / B" means "A or B." The phrase "A and / or B" means "(A and B) or (A or B)."
[0031] As used herein, the term "module" or "unit" may refer to, be or include: an application specific integrated circuit (ASIC), an electronic circuit, a (shared, dedicated or group) processor and / or memory that executes one or more software or firmware programs, a combinational logic circuit and / or other suitable components that provide the described functionality.
[0032] In the accompanying drawings, some structural or method features are shown in a specific arrangement and / or order. However, it should be understood that such a specific arrangement and / or order may not be required. In some embodiments, these features may be arranged in a manner and / or order different from that shown in the illustrative drawings. In addition, the inclusion of structural or method features in a specific figure does not mean that such features are required in all embodiments, and in some embodiments, these features may not be included or may be combined with other features.
[0033] It should be understood that although the terms "first", "second", etc. may be used here to describe various units or data, these units or data should not be limited by these terms. These terms are used only to distinguish one feature from another. For example, without departing from the scope of the exemplary embodiment, a first feature may be referred to as a second feature, and similarly, a second feature may be referred to as a first feature.
[0034] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.
[0035] While the present invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
Claims
1. An inductive linear position detection sensor, It is characterized in that include: A stator, comprising an electromagnetic induction unit, a protective shell and an information processing unit, wherein the electromagnetic induction unit and the information processing unit are arranged in the protective shell; An annular mover, wherein the surface of the annular mover is provided with induction protrusions, the induction protrusions are metal induction protrusions arranged alternately, and the longitudinal direction of the stator is parallel to the central axis direction of the annular mover; wherein, The stator is used to generate an excitation signal to generate a first electromagnetic field. When the annular mover moves along the central axis, the first electromagnetic field causes the annular mover to generate a second electromagnetic field, and the first electromagnetic field and the second electromagnetic field cause the electromagnetic induction unit to generate an induced current.
2. The sensor according to claim 1, It is characterized in that The stator is arranged inside the annular mover.
3. The sensor according to claim 2, It is characterized in that The inner diameter of the annular mover is greater than the outer diameter of the stator.
4. The sensor according to claim 3, It is characterized in that The inner surface of the annular mover is provided with a sensing protrusion.
5. The sensor according to claim 1, It is characterized in that The stator is arranged on the side of the annular mover.
6. The sensor according to claim 5, It is characterized in that The outer surface of the annular mover is provided with a sensing protrusion.
7. The sensor according to claim 1, It is characterized in that The stator and / or the annular mover may be made of a flexible material.