Field of the Invention

The present invention relates to a metal detection field, more particularly to a metal detection system and a metal detector.

Background of the Invention

At present, in metal detection technologies, usually a live coil is used to perform metal detection. The coil generates induced magnetic field after being powered. Once metal get close to the coil, induced eddy-current is generated in the metal, and a magnetic field generated by the eddy-current generates induced electromotive force which makes the oscillation frequency of the coil change. Thus the metal detection can be implemented by detecting the change of the oscillation frequency. Other modes for detecting the metal by using the live coil are also included in practical applications. A metal detector may be made up according to the above principle. After the metal detector is buried, when a vehicle stops above or passes through the metal detector, the metal detector can detect the vehicle. Figures la and lb respectively are a schematic planform and side elevation illustrating the structure of a metal detection system in the prior art. As shown in Figures la and lb, a coil 11 and a signal processing circuit 12 are placed parallelly, i.e. the coil 11 and the signal processing circuit 12 are arranged at the same plane. The coil 11 is printed on a Printed Circuit Board (PCB), and the signal processing circuit 12 is printed on another PCB. Because both the battery of the signal processing circuit 12 and the PCB include metals which will consume a part of magnetic field generated by the coil and influent the distributing of the magnetic field, the receiving signal of the metal detector is reduced, which reduces the sensitivity of the metal detector and makes the detection result of the metal detector inaccurate.

Summary of the Invention

The examples of the present invention provide a metal detection system and a metal detector, which have high sensitivity andstability, small size and high reliability.

In an aspect of the present invention, a metal detection system is provided which includes a signal detecting unit and a signal processing unit, wherein

the signal detecting unit comprises a first PCB on which a coil is printed, and is adapted to determine whether there is metal nearby, and to output a detection signal if metal nearby is detected; the signal processing unit comprises at least one second PCB on which a circuit is printed, and is adapted to process the detection signal and output a detetion result;

the second PCB is perpendicular to the first PCB and the central line of the coil passes through the second PCB.

In an aspect of the present invention, the signal processing unit includes

a data processing module adapted to process the detection signal;

a power module adapted to provide power for the data processing module; and

an antenna module adapted to output the detection result.

In an aspect of the present invention, the signal processing unit includes one second PCB, and both the data processing module and the antenna module are printed on the second PCB.

In an aspect of the present invention, the signal processing unit includes two second PCBs; the data processing module is printed on one of the two second PCBs, and the antenna module is printed on the other one of the two second PCBs.

In an aspect of the present invention, the power module includes a button cell battery, and the button cell battery is arranged on any one of the at least one second PCB.

In an aspect of the present invention, the power module includes a plastic holder and a cylindrical cell battery; and

the plastic holder is adapted to fix the cylindrical cell battery on the signal detecting unit.

In an aspect of the present invention, the plastic holder includes:

a first portion, adapted to fix the cylindrical cell battery on the plastic holder;

a second portion, adapted to fix the plastic holder on the signal detecting unit; and

a third portion with a preset height connecting the first portion with the second portion.

In an aspect of the present invention, a metal detector is provided which includes the above metal detection system and a plastic housing; the plastic housing includes a base, a lid and at least one block;

a signal detecting unit in the metal detection systme includes at least one protrusion;

a side wall is arranged on the edge of the base; and

the side wall includes at least one groove;

the at least one protrusion of the signal detecting unit is adapted to be embeded into the at least one groove;

the at least one block is adapted to be embeded into the at least one groove, and is arranged above the at least one protrusion of the signal detecting unit; the upper surface of the block and the upper surface of the side wall of the base are arranged in the same plane; and

the lid and the base of the plastic housing are connected hermetically.

In an aspect of the present invention, the side wall of the base comprises an internal thread, the edge of the lid comprises an external thread corresponding to the internal thread, and the internal thread and the external thread are adapted to connect the base to the lid.

In an aspect of the present invention, the side wall of the base and the edge of the lid respectively comprise multiple screw holes; and

the metal detector further comprises multiple screws, the number of the screws and the screw holes are the same, the external thread of the screw corresponds to the internal thread of the screw hole, and the screws and the screw holes are adapted to connect the base to the lid.

In an aspect of the present invention, the inner side of the top of the lid has a groove corresponding to at least one second PCB in the signal processing unit.

In an aspect of the present invention, the metal detector further includes a seal ring adapted to seal the joint of the lid and base.

In an aspect of the present invention, the number of the protrusions on the signal detecting unit is the same with the number of the grooves on the base, and/or the number of the blocks is the same with the number of the grooves.

In an aspect of the present invention, when the number of the grooves is more than one, the grooves are arranged symmetrically around the centre of the base.

In an aspect of the present invention, the number of the protrusions on the signal detecting unit is larger than the number of the grooves on the base; the side wall of the base further includes at least one hole corresponding to the protrusions on the signal detecting unit, and the sum of the holes and the grooves is identical with the number of the protrusions; the protrusions are adapted to be embeded into the grooves and holes respectively.

In an aspect of the present invention, when the sum of the grooves and the holes is more than one, the grooves and the holes are arranged symmetrically around the centre of the base.

As can be seen, the metal detection system and metal detector provided by the examples of the present invetnion have the following advantages.

Firstly, in the metal detection system provided by the examples of the present invention, the first PCB of the signal detecting unit is perpendicular to the second PCB of the signal processing unit, so the signal detecting unit is much more sensitive to the metal, and thus the sensitivity of the metal detecting system is improved. In addition, compared with the case that the signal detecting unit and the signal processing unit are placed parallelly, the size of the metal detection system in the examples of the present invention is smaller and can be applied to more application occasions.

Further, in the metal detector provided by the examples of the present invention, the metal detection system can be fixed on the plastic housing firmly by using the grooves on the side wall of the base, the protrusions on the signal detecting unit and the blocks. By using the above mode of fixing the signal detecting unit, the diameter of the base is reduced when the thickness of the side wall of the base is unchanged, that is, the volumn of the base is reduced without affecting the strength of the base, and accordingly, the volumn of the metal detector is reduced. In addition, in the metal detector provided by the examples of the present invention, the base and the lid are connected by using the screws and screw holes, which further reduces the volumn of the metal detector and improves the strength of the metal detector. Moreover, by using of the groove on the top of the lid, the metal detection system is fixed on the plastic housing much firmly, and is not easy to be affect by external oscillation and pressure, hence the metal detector provided by the examples of the present invention has very hige stability.

In addition, in the metal detector provided by the examples of the present invention, the joint of the base and the lid are sealed with the seal ring, which further improves the hermeticity and the water resistance, therefore, the metal detector provided by the examples of the present invention has very high reliability.

Brief Description of the Drawings

Figure la is a schematic planform illustrating the structure of a metal detection system in the prior art.

Figure lb is a schematic side elevation illustrating the structure of a metal detection system in the prior art.

Figure 2a is a schematic planform illustrating the structure of a metal detection system according to an example of the present invention.

Figure 2b is a schematic side elevation illustrating the structure of a metal detection system according to an example of the present invention. Figure 3a is a schematic planform illustrating the structure of a metal detection system according to another example of the present invention.

Figure 3b is a schematic side elevation illustrating the structure of a metal detection system according to another example of the present invention.

Figure 4 is a schematic diagram illustrating a plastic holder in a power module of a metal detection system according to an example of the present invention.

Figure 5 is a schematic planform illustrating a signal detection unit arranged in a metal detector according to an example of the present invention.

Figure 6 is a schematic side elevation illustrating the structure of a base and a block in a plastic holder of a metal detection system according to an example of the present invention.

Figure 7 is a schematic planform illustrating the structure of a lid in a plastic holder of a metal detection system according to an example of the present invention.

Detailed Description of the Invention

The present invention will be illustrated in detail hereinafter with reference to specific examples to make the object, technical solutions and merits of the present invention more clear.

A metal detection system provided by an example of the present invention inlcues a signal detecting unit and a signal processing unit. The signal detecting unit includes a first PCB on which a coil is printed, and is adapted to determine whether there is metal nearby, and output a detection signal if metal nearby is detected. The signal processing unit includes at least one second PCB on which a circuit is printed. The signal processing unit is adapted to process the detection signal and output a detetion result. The at least one second PCB being perpendicular to the first PCB and the central line of the coil passing through the at least one second PCB.

Specifially, the signal prcessing unit includes a data processing module adapted to process the detection signal, a power module adapted to provide power for the data processing module and a antenna module adapted to output the detection result.

The examples of the present invention will be illustrated in detail hereinafter with the accompanying figures.

Figure 2b is a schematic side elevation illustrating the structure of a metal detection system according to an example of the present invention. As shown in Figure 2b, the metal detection system includes a signal detecting unit 21 and a signal processing unit 22. The signal processing unit 22 includes a second PCB, and a circuit is printed on the second PCB. For example, both a data processing module and an antenna module may be printed on the second PCB. As can be seen from the Figure 2b, the second PCB of the signal processing unit 22 is perpendicular to the first PCB of the signal detecting unit 21. In this way, when the working signal detecting unit 21 generates a magnetic field, the influence of the metal in the signal processing unit 22 on the magnetic field is minimized.

In the examples of the present invention, the antenna module and the data processing module may be respectively printed on differetn PCBs, which is convenient for a previous debugging and a subsequent fault detection.

Figure 3b is a schematic side elevation illustrating the structure of a metal detection system according to another example of the present invention. As shown in Figure 3 b, the metal detection system includes a signal detecting unit 31 and a signal processing unit 32. The signal processing unit 32 includes a data processing module 321 and an antenna module 322. The data processing module 321 and the antenna module 322 are respectively printed on two different PCBs. As can be seen from Figure 3b, both the data processing module 321 and the antenna module 322 are perpendicular to the signal detecting unit 31, and the central line of the signal detecting unit 31 passes through the data processing module 321 and the antenna module 322, that is, the data processing module 321 and the antenna module 322 are placed adjacently, and the central line of the signal detecting unit 31 passes through the intersection of the data processing module 321 and the antenna module 322. In this example, the central line of the signal detecting unit 31 is the central line of the coil in the signal detecting unit 31. Therefore, in the example, when the working signal detecting unit 31 generates a magnetic field, the influence of the metal in the signal processing unit 32 on the magnetic field is minimized.

In the exammples of the present invention, the second PCB of the signal processing unit is perpendicular to the first PCB of the signal detecting unit. In practical applications, the first PCB may be basically perpendicular to the second PCB, which does not affect the implementation of the present invention.

In the two examples shown in Figures 2a, 2b and Figures 3a,3b, the first PCB of the signal detecting unit 31 may be of round shape, which is convenient to print the coil on the first PCB. In practial applications, the first PCB may be of other shape, which does not affect the implementation of the present invention. In addition, the examples shown in Figures 2a, 2b and Figures 3a,3b, the power module may be printed on any PCB, and the power module may be a button cell battery in this case.

In the example of the present invention, the power may also be a cylindrical cell battery, so as to provice enough electirc energy. In this case, the electical source module includes a plastic holder and a cylindrical cell battery, and the plastic holder is adapted to fix the cylindrical cell battery on the signal detecting unit.

Figure 4 is a schematic diagram illustrating a plastic holder in a power module of a metal detection system according to an example of the present invention. As shown in Figure 4, the plastic holder 40 includes three portions, which respectively are a first portion 41 adapted to fix the cylindrical cell battery on the plastic holder 40, a second portion 42 adapted to fix the plastic holder 40 on the signal detecting unit, and a third portion 43 with a preset height. The third portion 43 connects the first portion 41 with the second portion 42. The second portion 42 includes at least one protrusion, accordingly, there is at least one corresponding hole configured on the signal detecting unit, and the plastic holer 40 is fixed on the signal detecting unit by cooperatation of the protrusion and hole. In practial application, the first portion 41 may adopt mulitple modes, such as may be configured according to the number of the cylindrical cell batteries. In addition, the third portion 43 may also adopted mulitple modes, as long as the third portion 43 can fixed on the signal detecting unit firmly.

As can be seen that, in the metal detection system provided by the examples of the present invention, the first PCB of the signal detecting unit is perpendicular to the second PCB of the signal processing unit, so the signal detecting unit is much more sensitive to the metal, and thus the sensitivity of the metal detecting system is improved. In addition, compared with the case that the signal detecting unit and the signal processing unit are placed parallelly, the size of the metal detection system in the examples of the present invention is smaller and can be applied to more application occasions.

Based on the above metal detection system, the examples of the present invention also provide a metal detector including the metal detection system and a plastic housing. Specifically, the plastic housing includes a base, a lid and at least one block. The signal detecting unit in the metal detection systme includes at least one protrusion; a side wall is arranged on the edge of the base, and the side wall includes at least one groove; the at least one protrusion of the signal detecting unit is adapted to be embeded into the at least one groove; the at least one block is adapted to be embeded into the at least one groove, and is arranged above the at least one protrusion; the upper surface of the block and the upper surface of the side wall of the base are arranged in the same plane. The lid and the base of the plastic housing are connected hermetically.

The examples of the present invention will be illustrated in detail hereinafter with the accompanying figures.

In the following examples, the plastic housing of the metal detector is a cylinder so as to be convenient for the machining of the plastic housing. In practical application, the plastic housing of the metal detector may also be of other shape, such as square and so on, which does not affect the implementation of the present invention.

Figure 5 is a schematic planform illustrating a signal detection unit arranged in a metal detector according to an example of the present invention. As shown in Figure 5, the signal detecting unit 50 arranged in a metal detector includes two protrusions 501 arranged symmetrically, so as to fix the signal detecting unit 50 on the metal detector conveniently.

Figure 6 is a schematic side elevation illustrating the structure of a base and a block in a plastic holder of a metal detection system according to an example of the present invention. As shown in Figure 6, in the example, the base 60 includes two grooves 601, and the two grooves 601 are arranged symmetrically around the centre of the base 60. Correspondingly, the signal detecting unit also includes two protrusions arranged symmetrically. In this way, in the metal detector, the protrusions of the signal detecting unit are embedded into the grooves 601, and the block 61 is arranged above the protrusions of the signal detecting unit and is embedded into the grooves 601, thereby fixing the signal detecting unit on the base 60 of the plastic housing.

Accordingn to the above examples, the signal detecting unit is fixed on the base of the plastic housing firmly, moreover, compared with conventional fixing modes, e.g. filling glue, since a part of the signal detecting unit is embeded into the grooves of the base, the diameter of the base is reduced when the thickness of the side wall of the base is kept unchanged, and thus the volume of the base is reduced when the strength of the base is not affected, thereby reducing the size of the metal detector.

In the examples of the present invention, in order to connect the base to the lid hermetically, the side wall of the base and the edge of the lid respectively include internal thread and external thread corresponding to the internal thread, so as to connect the base with the lid by using the thread.

In order to further improve the strength of the metal detector and reduce the volume of the metal detector, in the example of the present invention, the side wall of the base and the edge of the lid respectively include multiple screw holes, and the metal detector further includes multiple screws, the number of the screws and the screw holes are the same, the external thread of the screw corresponds to the internal thread of the screw hole, so as to connect the base to the lid. As shwon in Figure 6, the side wall of the base includes six screw holes, correspondingly, the edge of the lid also includes six screw holes, thus the base is connect with the lid by using the six screws.

By using the screws and screw holes, the base and the lid are connected close, moreover, compared with the mode of thread, the volumn of the metal detector is further reduced, and the strength of the metal detector is improved. By using the mode of thread, the side wall of the base needs to have a certain thickness and highness to ensure the tightness, but by using the screws and screw holes, the requirements for thickness and highness of the side wall of the base is low. Hence, by using the screws and screw holes, the height and diameter of the base is recuded and thus the volumn of the metal detector is reduced. In addtion, when the screws and screw holes is used, the side wall of the base does not have thread, thus the strength of the side wall of the base is higher than that when the mode of thread is adopted, and when the metal detecotr is buried, stronger roller compactio can be resisted.

In addition, in order to connect the base to lid of the plastic housing more hermetically, the metal detector further includes a seal ring adapted to seal the joint of the lid and base. In this case, in the metal detector, grooves corresponding to the seal ring are configured at the lower end of the lid and the upper end of the side wall of the base to place the seal ring.

Figure 7 is a schematic planform illustrating the structure of a lid in a plastic holder of a metal detection system according to an example of the present invention. As shown in Figure 7, on the inner side of the top of the lid 70, there is a groove corresponding to the at least one second PCB in the signal processing unit. In the metal detector, the second PCB of the signal processing unit is embedded into the groove on the inner side of the lid 70, so as to fix the signal processing unit. In this case, the base is connected with the lid 70 of the metal detector by using the screws and screw holes.

Figure 6 only shows an preferable example of the base of metal detector, in the examples of the present invention, the number of the protrusions on the signal detecting unit may be larger than the number of the grooves on the base. In this case, the side wall of the base further includes at least one hole corresponding to the protrusions on the signal detecting unit, and the sum of the holes and the grooves is identical with the number of the protrusions on the signal detecting unit. In this way, in the metal detector, the protrusions on the signal detecting unit are adapted to be embeded into the grooves and holes on the side wall of the base, therefore, the signal detecting unit can be fixed on the base more firmly, and the package of the metal detector is more easily.

When the number of the protrusions on the signal detecting unit is more than two, if the side wall of the base only includes grooves, the grooves are arranged symmetrically around the centre of the base; if the side wall of the base includes grooves and holes, the grooves and the holes are arranged symmetrically around the centre of the base. In this way, the stress resisted by the signal detecting unit is more symmetrical, and the metal detector is firmer.

As can be seen, in the metal detector provided by the examples of the present invention, the metal detection system can be fixed on the plastic housing firmly by using the grooves on the side wall of the base, the protrusions on the signal detecting unit and the blocks. By using the above mode of fixing the signal detecting unit, the diameter of the base is reduced when the thickness of the side wall of the base is unchanged, that is, the volumn of the base is reduced without affecting the strength of the base, and accordingly, the volumn of the metal detector is reduced. In addition, in the metal detector provided by the examples of the present invention, the base and the lid are connected by using the screws and screw holes, which further reduces the volumn of the metal detector and improves the strength of the metal detector. Moreover, by using of the groove on the top of the lid, the metal detection system is fixed on the plastic housing much firmly, and is not easy to be affect by external oscillation and pressure, hence the metal detector provided by the examples of the present invention has very hige stability.

In addition, in the metal detector provided by the examples of the present invention, the joint of the base and the lid are sealed with the seal ring, which further improves the hermeticity and the water resistance, therefore, the metal detector provided by the examples of the present invention has very high reliability.

After the metal detector provided by the examples of the present invetnion is buried, when a vehicle passes by, the metal detector can detect the vehicle, thus the metal detector can be buried under the groud of a park to perform parking stall detection of the park, or can be buried under the groud of a road to measure vehicle flow.

The present invention provides a metal detection system including a signal detecting unit and a signal processing unit. The signal detecting unit includes a first PCB on which a coil is printed, and is adapted to determine whether there is metal nearby and to output a detection signal if metal nearby is detected. The signal processing unit includes at least one second PCB on which a circuit is printed, and is adapted to process the detection signal and output a detetion result, the at least one second PCB is perpendicular to the first PCB and the central line of the coil passing through the at least one second PCB. The present invention also provides a metal detector. By using the examples of the present invention, the sensitivity of the metal detection systme is improved.

The foregoing are only preferred embodiments of the present invention and are not for use in limiting the protection scope of the present invention. Any modification, equivalent replacement and improvement made within the scope of the present invention should be covered under the protection scope of the present invention.