Disclosure of Invention
The invention mainly aims to provide a high-temperature resistant coil and a sensor, and aims to solve the technical problems of large quality factor change rate and unstable performance of the conventional coil and magnetic core in a high-temperature working environment.
In order to achieve the above object, the present invention provides a high temperature resistant coil, including:
the magnetic core is internally provided with a center pillar and is provided with an annular side wall;
the winding is positioned in the annular side wall and surrounds the center post, a first gap is formed between the winding and the center post, a second gap is formed between the winding and the annular side wall, and one end of the winding protrudes out of the end face of the magnetic core to form a protruding part.
As a further improvement of the invention: the length of the protruding part is 0.2-0.3 mm.
As a further improvement of the invention: the width of the first gap is 0.2-0.3 mm.
As a further improvement of the invention: the width of the second gap is 0.4-0.5 mm.
As a further improvement of the invention: the magnetic core is made of manganese-zinc ferrite.
As a further improvement of the invention: the winding is formed by winding a wire in an annular mode, the wire is formed by winding a plurality of single wires in parallel, and the single wires are made of copper materials.
As a further improvement of the invention: the diameter of the single wire is 0.05-0.1mm, and the wire is formed by winding 5-10 single wires.
As a further improvement of the invention: the magnetic core is provided with a bottom plate, the winding is arranged on the bottom plate, and an opening is formed in the radial direction of the annular side wall.
The invention also provides a sensor which comprises the high-temperature resistant coil.
As a further improvement of the invention: the sensor further comprises:
the PCB is electrically connected with the high-temperature resistant coil and used for providing stable voltage;
the power line is electrically connected with the high-temperature resistant coil and used for providing a working power supply;
the shell, the shell with high temperature resistant coil, the PCB board, the power cord fixed connection.
This technical scheme's high temperature resistant coil includes: the magnetic core is internally provided with a center pillar and is provided with an annular side wall; the winding is positioned in the annular side wall and surrounds the center post, a first gap is formed between the winding and the center post, a second gap is formed between the winding and the annular side wall, and one end of the winding protrudes out of the end face of the magnetic core to form a protruding part. The high-temperature resistant coil is provided with the first gap and the second gap, so that the constraint effect of the magnetic core on the magnetic induction line of the winding magnetic field can be reduced to a certain degree, and the coupling is reduced; meanwhile, one end of the winding protrudes out of the end face of the magnetic core, so that the winding can reasonably utilize the characteristics of the magnetic core, and the coupling between the magnetic core and the winding is further reduced, thereby achieving the purpose that the performance of the coil is kept highly stable in a wide temperature range, especially under a high-temperature condition, and then forming a high-temperature resistant sensor by utilizing the coil design.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture, and if the specific posture is changed, the directional indications are changed accordingly.
In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, if the meaning of "and/or" and/or "appears throughout, the meaning includes three parallel schemes, for example," A and/or B "includes scheme A, or scheme B, or a scheme satisfying both schemes A and B. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.
The quality factor Q of the inductor is an important parameter representing the quality of the coil. The Q value shows the loss of the inductance coil, and the larger the Q value is, the smaller the loss of the coil is; conversely, the greater its loss. The quality factor Q is defined as: when the coil is operated at an alternating voltage of a certain frequency, the ratio of the inductive reactance exhibited by the coil to the direct current resistance of the coil. It can be formulated as follows, depending on the application, the requirement for Q is also different for the inductor in the tuned loop, the Q is higher, because the higher the Q, the lower the loss of the loop and the higher the efficiency of the loop.
The quality factors of the existing coil and magnetic core are changed greatly, and the performance of the inductive sensor is seriously drifted under different temperatures, particularly high temperature conditions due to the material characteristics, circuit design and other reasons, so that an intersection point cannot be found at a certain current frequency, namely, under a certain fixed current frequency, stable work facing different temperatures cannot be realized. Therefore, the research and development difficulty, the analysis difficulty, the test and the cost of the high-temperature inductive sensor are very high.
In order to reduce the development difficulty of the high-temperature sensor, reduce the design cost, the material cost and the research and development time, a coil which can keep the characteristics almost unchanged in a wide range of temperature, especially in a high-temperature environment, is designed, and the high-temperature resistant inductive sensor is designed by utilizing the excellent performance of the coil.
The main purpose of this technical scheme is to provide a high temperature resistant coil and sensor, aims at solving current coil and magnetic core under high temperature operational environment, and its quality factor change rate is big, and the performance is unstable, is unfavorable for the technical problem who designs the sensor.
Referring to fig. 1-5, in an embodiment of the present invention, the high temperature coil includes:
a magnetic core 20, wherein a center pillar 22 is arranged in the magnetic core 20, and the magnetic core 20 is provided with an annular side wall 23;
the winding 10 is positioned in the annular side wall 23 and surrounds the center pillar 22, a first gap 31 is formed between the winding 10 and the center pillar 22, a second gap 32 is formed between the winding 10 and the annular side wall 23, and a protruding portion 11 is formed at one end of the winding 10 protruding out of the end face of the magnetic core 20.
Specifically, magnetic core 20 is equipped with bottom plate 24, the magnetic core is equipped with storage tank 21, winding 10 is arranged in storage tank 21 and is located on the bottom plate 24, the radial direction of annular lateral wall 23 is equipped with opening 25, opening 25 is located the both sides of center pillar 22 and sets up based on center pillar 22 symmetry, and this opening 25 is used for wearing to establish the wire of winding 10. In this embodiment, the width of the opening is 1.65mm, and the thickness of the bottom plate is 0.8 mm. By the winding being located in the annular side wall 23 and surrounding the center pillar 22, after the winding 10 is energized, a magnetic field is generated around the winding 10, and the magnetic core 20 can excite the ordered arrangement of magnetic domains inside the magnetic core under the action of an external magnetic field of the winding, so as to increase the magnetic flux passing through the winding 10, further increase the inductance of the winding 10, and also increase the parasitic capacitance of the winding 10.
The high-temperature resistant coil is provided with the first gap 31 and the second gap 32, so that the constraint effect of the magnetic core 20 on the magnetic induction line of the magnetic field of the winding 10 can be reduced to a certain degree, and the coupling is reduced; meanwhile, one end of the winding 10 protrudes out of the end face of the magnetic core, so that the winding 10 can reasonably utilize the characteristics of the magnetic core 20, and the coupling of the magnetic core 20 and the winding 10 is further reduced, so that the performance of the coil is kept highly stable in a wide temperature range, particularly under a high-temperature condition, and then a high-temperature-resistant sensor is formed by utilizing the coil design, the sensor does not need hardware or software temperature calibration, the design cost is lower, and the research and development time is shorter.
Further, the length L1 of the protruding part 11 is 0.2-0.3 mm. In the present embodiment, the length of the projection 11 is 0.26 mm. It should be noted that, in the conventional coil, the winding 10 is generally completely placed inside the magnetic core 20, which results in increased coupling between the winding 10 and the magnetic core 20, and thus, under different temperature environments, the temperature characteristic of the magnetic core 20 (the core loss exhibits a positive temperature characteristic in a certain temperature range, and the magnetic core permeability exhibits a negative temperature characteristic) will seriously disperse the frequency crossing points of the coupling of the quality factors, even no frequency crossing points. Therefore, one end of the winding 10 of the present application is disposed in the magnetic core, and the other end of the winding 10 protrudes from the end surface of the magnetic core 20.
Further, the width H1 of the first gap 31 is 0.2-0.3mm, in this embodiment, the diameter of the center pillar 22 is 2.24mm, the inner diameter of the winding 10 is 2.5mm, and the width H1 of the first gap 31 is 0.26 mm.
Further, the width H2 of the second gap 32 is 0.4-0.5mm, in this embodiment, the inner diameter of the annular sidewall is 4.57mm, the outer diameter of the winding 10 is 4.1mm, and the width H2 of the second gap 32 is 0.47 mm.
Referring to fig. 9, fig. 9 is a performance diagram of the coil and core of the present application, the data shown in the performance diagram is derived from physical measurements of the winding and core, the abscissa is the current frequency, the ordinate is the rate of change of the coil quality, and different curves represent the performance of the coil quality rate at different temperatures. As can be seen from fig. 9, when the current frequency is increased to 540460Hz-570430Hz at the measured operating temperatures (-25 ℃, 0 ℃, 70 ℃, 100 ℃, 130 ℃), the quality factor change rate of the magnetic core and the winding is close to zero at the current frequency in the interval, i.e. the quality change rate of the coil in the interval can be kept highly consistent at different temperatures, so the coil of the present application has high operating stability.
In summary, since the first gap 31 is formed between the winding 10 and the center pillar 22, the second gap 32 is formed between the winding 10 and the annular side wall 23, the protruding portion 11 is formed at the end face of the winding 10 protruding from the magnetic core, and the winding 10 and the magnetic core 20 have a certain coupling relationship by adjusting and matching the structural dimensions of the winding 10 and the magnetic core 20, so as to avoid the magnetic core 20 from completely affecting the performance of the winding 10, and reduce the loss of the winding 10 and the loss of the magnetic core 20 at different temperatures; meanwhile, by utilizing the frequency characteristics of the winding 10 and the magnetic core 20, the quality factors of the magnetic core 20 and the winding 10 reach stable values in the frequency range of 540460Hz-570430Hz, so that the research and development difficulty and material cost of the high-temperature resistant inductive sensor are reduced, and the development of an inductive sensor product without temperature compensation is realized.
Further, the magnetic core 20 is made of manganese-zinc ferrite, and the manganese-zinc ferrite is made of oxides of iron, manganese and zinc and salts thereof by adopting a ceramic process. It has a high initial permeability. Typically in the frequency range of 1 khz to 10 mhz. The method is commonly used in the fields of manufacturing magnetic cores of inductors, transformers and filters, magnetic heads and antenna rods.
Further, the winding 10 is formed by winding a wire in an annular manner, the wire is formed by winding a plurality of single wires in parallel, and the single wires are made of copper materials.
Specifically, in the present embodiment, the main component of the winding 10 is copper, the resistivity of copper varies at different temperatures, and the main component of the magnetic core 20 is manganese-zinc material, so the magnetic permeability, loss, and frequency characteristics of the magnetic core and the winding have certain temperature characteristics.
Furthermore, the diameter of the single wire is 0.05-0.1mm, and the conducting wire is formed by winding 5-10 single wires. In this embodiment, the single wire has a diameter of 0.07 mm. The wire is formed by winding 7 strands of single wires. Under the action of the applied magnetic field of the winding 10, the applied magnetic field excites the ordered arrangement of magnetic domains inside the magnetic core 20, thereby increasing the magnetic flux through the coil, and thus increasing the inductance of the coil, and at the same time increasing the parasitic capacitance of the coil.
Referring to fig. 5, based on the above-mentioned high temperature resistant coil, the present embodiment further provides a sensor, which includes the above-mentioned high temperature resistant coil, and includes:
the PCB 44 is used for providing stable voltage, bears a self-stabilizing circuit and electronic components and is electrically connected with the high-temperature coil and the power line;
the power line 41 is electrically connected with the high-temperature resistant coil and used for providing a working power supply, providing required voltage and current for a sensor product and sending an output signal of the sensor;
and the shell is fixedly connected with the high-temperature resistant coil, the PCB 44 and the power line 41.
Further, the housing further comprises:
the plastic cap 45 is used for sealing the whole sensor product, so that the sensor product has the characteristics of water resistance and dust resistance and provides insulating property for the high-temperature resistant coil;
a metal screw shell 43 for sealing the entire sensor product to have waterproof and dustproof properties;
and the plastic tail cover 42 is used for sealing the whole product, so that the product has the waterproof and dustproof characteristics and carries the power line 41.
The above description is only an alternative embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.