Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are 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 the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.
In one embodiment, as shown in fig. 1, there is provided a metal detection apparatus including a transmission coil 100, a first receiving coil 200, and a second receiving coil 300;
the transmitting coil 100 is arranged in parallel with the first receiving coil 200 and the second receiving coil 300, the first receiving coil 200 and the second receiving coil 300 are arranged on the same side of the transmitting coil 100, the electromagnetic field directions of the first region and the second region in the first receiving coil 200 and the second receiving coil 300 are opposite, and when no metal is detected, the magnetic field flux in the first region of the first region is equal to the magnetic field flux in the second region, and the first region of the first region is a region overlapped with the projection of the transmitting coil 100; the second region is a region not projectively overlapped with the transmission coil 100;
the first receiving coil 200 and the second receiving coil 300 have the same winding direction, and one end of the first receiving coil 200 is connected to one end of the second receiving coil 300.
Wherein, the transmitting coil is a coil winding which continuously transmits an alternating electromagnetic field in the metal detection device; the receiving coil is a coil winding used for inducing and receiving a surrounding electromagnetic field (including an alternating electromagnetic field continuously emitted by the transmitting coil) in the metal detection device; specifically, the transmitting coil 100 in the metal detection device is disposed in parallel with the first receiving coil 200 and the second receiving coil 300, the first receiving coil 200 and the second receiving coil 300 are located right above the transmitting coil 100, the first receiving coil 200 and the second receiving coil 300 are disposed on the same side of the transmitting coil 100, the first receiving coil 200 and the second receiving coil 300 are disposed in parallel with the transmitting coil 100, a portion of the transmitting coil 100 is projectively overlapped with the first receiving coil 200, a portion of the projection is projectively overlapped with the second receiving coil 300, a region where the projection is overlapped with the first receiving coil 200 or the second receiving coil 300 is a first region of the first region, a region where the first region is not projectively overlapped with the transmitting coil 100 is a second region, wherein the electromagnetic field directions in the first region and the second region are opposite, for example, the electromagnetic field direction in the first region is defined as +, the electromagnetic field direction in the second region is defined as-either the first receiving coil 200 or the second receiving coil 300 is selected, and the total electromagnetic flux surrounded by the receiving coil is-much when moving away from the center of the transmitting coil 100 and + much when moving towards the center of the transmitting coil 100, the relative position of the first receiving coil 200 and the transmitting coil 100 is adjusted to make the magnetic fluxes in the first region and the second region cancel each other, the total electromagnetic flux surrounded by the first receiving coil 200 is the sum of the magnetic fluxes in the first region and the second region and is close to 0, then the position of the second receiving coil 300 is adjusted to make the total electromagnetic flux thereof be close to 0 as much as possible, when no metal is detected, the magnetic flux in the first region and the magnetic flux in the second region cancel each other, at this time, the voltages generated by the first receiving coil 200 and the second receiving coil 300 are in a relatively balanced state, and besides, since the first receiving coil 200 is connected to one end of the second receiving coil 300 and the winding directions of the two coils are the same and are both clockwise or both counterclockwise, the total induced voltage output by the two receiving coils is obtained by superposing the induced voltages of the two receiving coils, wherein the formula of the induced voltage is according to E ═ n Δ Φ/Δ t: induced electromotive force (V), n: the number of turns of the induction coil, Δ Φ/Δ t, the rate of change of the magnetic flux, for example, when the induced voltage output from the first receiving coil 200 is +0.01v and the induced voltage output from the second receiving coil 300 is +0.01v, the total induced voltage output is +0.02v, and the change of the total induced voltage is more easily seen than +0.01 v. The sensitivity of the receiving coil to the magnetic field induction of the metal can be enhanced, a detection blind area can not be formed, and the accuracy of metal detection is greatly improved.
In the above metal detecting apparatus, the transmitting coil 100 is disposed in parallel with the first receiving coil 200 and the second receiving coil 300, and the first receiving coil 200 and the second receiving coil 300 are disposed on the same side of the transmitting coil 100, the electromagnetic field directions of the first region and the second region of the first receiving coil 200 and the second receiving coil 300 are opposite, and when no metal is detected, the magnetic field flux in the first region is equal to the magnetic field flux in the second region, and when no metal is detected around the first region and the second region, the magnetic flux in the first region and the second region can cancel each other out, at this time, the first receiving coil 200 and the second receiving coil 300 are in a state of voltage relative balance, the output induced voltages are all close to 0, for example, the induced voltage output by the first receiving coil 200 is +0.01, the induced voltage output by the second receiving coil 300 is +0.01, and meanwhile, the winding directions of the first receiving coil 200 and the second receiving coil 300 are the same, And the first receiving coil 200 is connected with one end of the second receiving coil 300, and the induced voltage generated in the first receiving coil 200 is superposed with the induced voltage generated in the second receiving coil 300, so that whether a metal object exists can be detected by using the obtained total induced voltage change as a basis.
In one embodiment, the metal detecting apparatus further includes a connecting wire, and one ends of the first receiving coil 200 and the second receiving coil 300 are connected by the connecting wire.
Specifically, the ends of the first receiving coil 200 and the second receiving coil 300 are connected by a connecting wire to form a complete electrical loop, and since the connecting wire also causes some induced voltage variation, the semicircular antenna of one receiving coil can be slightly moved to be closer to or farther from the center of the transmitting coil 100 after the two receiving coils are connected, so that the total induced voltage output can be closer to 0.
In this embodiment, one end of the first receiving coil 200 and one end of the second receiving coil 300 are connected through a connecting wire, and the other end of the first receiving coil 200 and the second receiving coil 300 are used for outputting the total induced voltage of the two coils to form a complete electrical loop for subsequently transmitting the total induced voltage generated in the first receiving coil 200 or the second receiving coil 300 to a signal analysis circuit.
In one embodiment, the metal detection device further comprises a power source, and the transmitting coil 100 is connected to the power source.
In particular, the condition for the transmitting coil 100 to generate an alternating electromagnetic field is that an electrical circuit needs to be switched in to generate an alternating current. In the metal detector of the present application, the transmitting coil 100 is connected to the power supply of the metal detector, so that the circuit is switched on, and the transmitting coil 100 transmits a continuous alternating magnetic field as the power supply is turned on.
In this embodiment, the transmitting coil 100 is connected to an internal power source to generate an alternating current to emit a continuous alternating magnetic field, the receiving coil receives the alternating magnetic field emitted from the transmitting coil 100, and the first receiving coil 200 receives the alternating magnetic field emitted from the transmitting coil 100 and outputs an induced voltage E in a first region overlapping the projection of the transmitting coil 1001The second receiving coil 300 also outputs an induced voltage E after receiving the alternating magnetic field emitted by the transmitting coil 1002Since the first receiving coil 200 and the second receiving coil 300 have the same winding direction, the induced voltage E output from the first receiving coil 2001And the induced voltage E output by the second receiving coil 3002The symbols are consistent, and the total induced voltage output by the receiving coil is obtained by superposing two induced voltages, namely E-E1+E2And obtaining the total induction voltage superposed by the two coils for being used as the basis for detecting whether the metal exists or not.
In one embodiment, the first receiving coil 200 and the second receiving coil 300 are located on the same plane.
Specifically, the first receiving coil 200 and the second receiving coil 300 are located on the same plane, the first receiving coil 200 and the second receiving coil 300 together form a receiving coil system, the transmitting coil 100 is uniformly projected in the receiving coil system, so as to avoid that the difference between the magnetic fluxes received by the two receiving coils is too large due to the inconsistent distances between the transmitting coil 100 and the first receiving coil 200 and the second receiving coil 300, so that the obtained difference between the induced voltages is too large, which affects the accuracy and precision of metal detection, the receiving coil system outputs the total induced voltage as the sum of the induced voltages generated by the first receiving coil 200 and the second receiving coil 300, because the directions of the first receiving coil 200 and the second receiving coil 300 are the same, the total induced voltage is obtained by overlapping the induced voltages generated by the two coils, when the metal around is detected, the change of the total induced voltage is used as the basis for detecting whether the metal around exists, if the total induced voltage is changed too much, it can be determined that metal exists around
In this embodiment, the first receiving coil 200 and the second receiving coil 300 are located on the same plane, so that the difference between the magnetic fluxes received by the two receiving coils due to the inconsistent distances between the transmitting coil 100 and the first receiving coil 200 and the second receiving coil 300 can be effectively avoided, and thus, the difference between the obtained induced voltages is too large, the error is reduced, and the accuracy and precision of metal detection are improved.
In one embodiment, the first receiving coil 200 and the second receiving coil 300 are equal in size.
Specifically, the first receiving coil 200 and the second receiving coil 300 are equal in size, the transmitting coil 100 is uniformly projected in the first receiving coil 200 and the second receiving coil 300200, the ranges of the alternating magnetic fields induced by the two coils and received by the transmitting coil 100 are the same, and the magnetic fluxes surrounded by the two coils are approximately equal.
In this embodiment, the first receiving coil 200 and the second receiving coil 300 have the same size, which ensures that the ranges of the alternating magnetic fields induced by the two coils and received by the transmitting coil 100 are the same, so that the magnetic fluxes surrounded by the two coils are approximately equal, the difference of the generated induced voltages is very small, and the interference on the detection of the metal caused by the overlarge difference of the induced voltages is avoided, thereby affecting the accuracy and precision of the metal detection.
In one embodiment, the first receiving coil 200 and the second receiving coil 300 are two semi-circles with equal areas, and the area enclosed by the first areas of the first receiving coil 200 and the second receiving coil 300 is equal to the size of the transmitting coil 100.
Specifically, the first receiving coil 200 and the second receiving coil 300 have the same area and the same shape as a semicircle, and are symmetrically distributed, which is beneficial to cancel the magnetic fluxes + -of the first region and the second region of the first receiving coil 200 and the second receiving coil 300, so that the output induced voltage is close to 0, meanwhile, the region enclosed by the first region of the first receiving coil 200 and the first region of the second receiving coil 300 is equal to the size of the transmitting coil 100, i.e. the collective region of the projection overlapping portions of the transmitting coil 100 and the two receiving coils is equal to the size of the transmitting coil 100, the first receiving coil 200 and the second receiving coil 300 averagely divide the transmitting coil 100100 into two parts, so that half of the transmitting coil 100 is projected in the first receiving coil 200, and half is projected in the second receiving coil 300.
In this embodiment, the first receiving coil 200 and the second receiving coil 300 are two semicircles with the same area, and the alternating magnetic fields received by the two semicircles have the same range and the same surrounding magnetic flux, so that the induced voltage generated by the two coils can be ensured to be very small, and the interference on the detection of the metal due to the too large difference of the induced voltage is avoided, thereby affecting the accuracy and precision of the metal detection.
In one embodiment, the transmitting coil 100 has the same projected area in the first receiving coil 200 and the second receiving coil 300.
Specifically, half of the transmitting coil 100 is projected on the first receiving coil 200, and half of the transmitting coil is projected on the second receiving coil 300, so as to form two equal projection areas, and the alternating magnetic field in the transmitting coil 100 is uniformly distributed around the first and second receiving coils 300.
In this embodiment, the transmitting coil 100 is uniformly projected in the first receiving coil 200 and the second receiving coil 300, and the formed projection areas are equal, so that the magnetic fluxes surrounded by the first receiving coil 200 and the second receiving coil 300 are substantially the same, and the induced voltage difference value output by the two coils is ensured to be small, thereby avoiding the interference on the detection of the metal due to the overlarge induced voltage difference value, and further avoiding the influence on the accuracy and precision of the metal detection.
In one embodiment, as shown in fig. 2, the metal detection device further includes a switch module and a signal analysis circuit, and the other ends of the first receiving coil 200 and the second receiving coil 300 are connected to the signal analysis circuit through the switch module.
The signal analysis circuit is a circuit capable of receiving, processing and analyzing metal signals; specifically, the first receiving coil 200 and the second receiving coil 300 respectively output an induced voltage and a total induced voltage, the other ends of the first receiving coil 200 and the second receiving coil 300 are connected to the signal analysis circuit 400 through the switch module, and the obtained total induced voltage is received, amplified and analyzed by the signal analysis circuit, so as to obtain a final metal detection result.
In this embodiment, the two receiving coils are connected to the signal analyzing circuit through the switch module, the change of the total induced voltage is used as a basis for judging whether metal exists around, and after the two coils are received, amplified and analyzed by the signal analyzing circuit, an accurate metal detection result can be obtained.
In one embodiment, as shown in fig. 2, the signal analyzing circuit includes an operational amplifier and a processor connected to each other, the operational amplifier being connected to the first receiving coil 200 and the second receiving coil 300, respectively.
An operational amplifier is an application specific integrated circuit that can perform various functions or operations (such as amplification, addition, and subtraction); specifically, the signal analysis circuit needs to include an operational amplifier and a signal processor in order to realize the functions of receiving, amplifying and analyzing the metal signal, where the operational amplifier is connected to the first receiving coil 200 and the second receiving coil 300, and the operational amplifier 401 amplifies the total induced voltage output by the first receiving coil 200 and the second receiving coil 300, so that the subsequent processor 402 can analyze the total induced voltage to obtain an accurate metal detection result.
In this embodiment, the operational amplifier is connected to the first receiving coil 200 and the second receiving coil 300, and after the total induced voltage output by the two receiving coils is amplified by the operational amplifier, the total induced voltage is convenient for the processor to analyze, so that an accurate metal detection result can be obtained.
In one embodiment, the switching device is a MOS transistor or a triode.
Specifically, the switching device comprises a MOS transistor or a triode, and the triode and the MOS transistor are commonly used electronic components, both of which can be used as an electronic switching tube, and in many occasions, the triode and the MOS transistor can be used interchangeably.
In order to better explain the technical scheme, the implementation process and technical principle of the whole scheme are completely described.
The metal detection device comprises a transmitting coil 100, a first receiving coil 200 and a second receiving coil 300, wherein the transmitting coil 100, the first receiving coil 200 and the second receiving coil 300 are arranged in parallel relatively, the first receiving coil 200 and the second receiving coil 300 are positioned on the same side and on the same plane, the two receiving coils are equal in size and are two semicircles with equal areas, the transmitting coil 100 is connected with a power supply inside the metal detection device, a continuous alternating magnetic field is transmitted and uniformly projected in the first receiving coil 200 and the second receiving coil 300, the part of the two receiving coils, which is projected and overlapped with the transmitting coil 100, is a first area, the part of the two receiving coils, which is not projected and overlapped with the transmitting coil 100, is a second area, the projected areas of the transmitting coil 100 in the first receiving coil 200 and the second receiving coil 300 are equal, and the directions of electromagnetic fields in the first area and the second area are opposite, the magnetic flux in the first region is defined as + and the magnetic flux in the second region is defined as-a middle position where the magnetic flux in the first region and the magnetic flux in the second region are cancelled exists in both the two receiving coils, at this time, the magnetic flux surrounded by the two receiving coils is the sum of the magnetic flux in the first region and the magnetic flux in the second region, the induced voltage generated according to the magnetic flux is close to 0, and within a preset range, the induced voltage is taken as a critical condition for judging that no metal exists around, and meanwhile, one end of the first receiving coil 200 and one end of the second receiving coil 300 are connected through a conducting wire, and the other end of the first receiving coil and the other end of the second receiving coil are connected with a signal analysis circuit through a switch module to form a complete electric loop. Since the winding directions of the first receiving coil 200 and the second receiving coil 300 are the same, the directions of the induced voltages generated by the two receiving coils according to the enclosed magnetic flux are the same, and the total output induced voltage is obtained by the superposition of the induced voltages generated by the two receiving coils, for example: the induced voltage generated by the first receiving coil 200 is +0.01v, the induced voltage generated by the second receiving coil 300 is +0.01v, and the total induced voltage output thereby is +0.02v, and then the signal analyzing circuit receives the output induced voltage, wherein the operational amplifier amplifies the output induced voltage, and then the signal analyzing circuit analyzes the amplified output induced voltage, and determines whether metal exists around according to the change of the total induced voltage, and if the obtained value of the total induced voltage exceeds a preset range, a determination result of the metal existing around is obtained.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above examples only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.