CN201155973Y - Magnetic induction distance detection device - Google Patents

Abstract

A magnetic induction distance detection device, comprising a plate-shaped magnetically conductive support formed with a through hole; a ring-shaped magnetic steel fixed on the upper surface of the magnetically conductive support around the through hole; a first cylindrical magnetic steel, which fixed on the lower surface of the magnetically permeable bracket; one is a barrel-shaped magnetically permeable shield with an open top, the top of the magnetically permeable shield is closed and fixedly connected to the lower surface of the magnetically permeable bracket, and The first cylindrical magnet is accommodated in the magnetically permeable shield; a second cylindrical magnet is fixedly arranged on the lower end surface of the magnetically permeable shield; and a magnetic induction sensor is The sensing detection unit on the top is arranged between the object to be detected and the through hole. The magnetic induction distance detection device of the utility model is equipped with a magnetically conductive shielding cover with an anti-interference cylindrical magnetic steel outside the bottom end, so when used as a door switch detection device for a container, it has high sensitivity, strong reliability and anti-interference The advantages.

Description

Magnetic induction distance detection device

technical field

The utility model relates to a magnetic induction distance detection device, in particular to a magnetic induction distance detection device which can effectively resist malicious magnetic interference on the sides and back of the detection device.

Background technique

With the continuous development and expansion of international trade, container transportation has become an important means of freight widely used by countries all over the world because of its advantages of large freight capacity and low transportation cost. However, in recent years, countries around the world have generally increased their security awareness of preventing risks and terrorist activities. Various countries have higher and higher requirements for the safety of containers during transportation. One of the more important requirements is to track and supervise the entire supply chain process of containers on a global scale, so as to realize the sealing of containers from delivery to the destination. The entire process of delivery and unpacking is supervised to ensure the safety of the entire container freight transportation process, and any illegal opening of the container door during the entire supply chain process is not allowed. In order to monitor the opening and closing of the door, a more advanced method is to install a magnetic induction distance detection device near the door of the container, and use the distance detection device to detect the distance between the two doors or the distance between the door and the door frame. To monitor the opening and closing of the box door, however, for the current distance detection device, when there is malicious magnetic interference on the sides and back of the device, it often cannot work normally and causes false detection, so it cannot be well detected. Control the illegal opening of the door during transportation.

Contents of the invention

The main purpose of the utility model is to provide a magnetic induction distance detection device that can effectively resist malicious magnetic interference from the sides and back of the detection device, and has high sensitivity and reliability.

In order to achieve the above purpose, the utility model provides a magnetic induction distance detection device for monitoring the opening and closing of the container door. Magnetic steel, the ring-shaped magnetic steel is fixed on the upper surface of the magnetic permeable bracket around the through hole; a first cylindrical magnetic steel, the first cylindrical magnetic steel is located at the lower end of the through hole and fixed on The lower surface of the magnetically permeable support; a magnetically permeable shield, the magnetically permeable shield is a barrel-shaped structure with an open top, and the top of the magnetically permeable shield is closed and fixedly connected to the magnetically permeable support The lower surface, and the first cylindrical magnetic steel is accommodated in the magnetic permeable shield; a second cylindrical magnetic steel, the second cylindrical magnetic steel is fixedly arranged on the magnetic permeable shield and a magnetic induction sensor, the magnetic induction sensor includes a sensing detection unit and a circuit conversion unit electrically connected with the sensing detection unit, and the sensing detection unit is arranged between the distance object to be detected and the described Between the through holes and detect the change of the magnetic field strength to output the corresponding distance change signal.

The inner diameter of the ring-shaped magnet is the same as the diameter of the through hole and slightly smaller than the outer diameter of the first cylindrical magnet, and the size of the second cylindrical magnet is the same as that of the first cylindrical magnet. and the shape is the same; and the magnetization direction of the ring magnet is the direction perpendicular to the ring plane where the ring magnet is located, the magnetization direction of the first column magnet and the second column magnet is the direction perpendicular to the upper and lower end surfaces of the cylinder; the magnetic polarity of the upper and lower end surfaces of the ring magnet is the same as that of the upper and lower end surfaces of the first cylindrical magnet, and the upper and lower end surfaces of the second cylindrical magnet are The magnetic polarity is opposite to that of the upper and lower end faces of the first and second cylindrical magnets.

A counterbore is provided at the center of the outer end surface of the bottom of the magnetically permeable shield, and the top end of the second cylindrical magnetic steel is embedded in the counterbore.

The depth of the counterbore is 0.5mm.

The through hole is a circular hole, and the central axis of the ring magnet, the through hole, the first cylindrical magnet, the magnetic shield and the second cylindrical magnet is coincide.

The object to be detected is made of a magnetically conductive material or the object to be detected is provided with a magnetically conductive object, and the sensing detection unit is arranged in the hollow position of the ring magnet, and is connected to the ring magnet The circular planes are parallel.

The sensing and detection unit is arranged on the object to be detected at a position corresponding to the hollow position of the ring magnet, and is parallel to the ring plane where the ring magnet is located.

The sensing detection unit is a linear Hall sensor.

The utility model has the following beneficial effects. The magnetic induction distance detection device of the utility model can detect the short-distance object distance by detecting the change of the magnetic field intensity, and the bottom end is equipped with a magnetic guide with anti-interference cylindrical magnetic steel The high-quality shielding cover can effectively resist malicious interference from the external magnetic fields around the sides and the back, so when used as a door switch detection device for containers, it has the advantages of high sensitivity, strong reliability and anti-interference.

Description of drawings

Fig. 1 is the three-dimensional exploded view of the magnetic induction distance detection device of the present invention;

Fig. 2 is a structural schematic diagram of the sensor detection unit installed in position 1 of the magnetic induction distance detection device of the present invention;

Fig. 3 is a structural schematic diagram of the sensor detection unit of the magnetic induction distance detection device of the present invention installed at position 2.

Detailed ways

The magnetic induction distance detecting device 1 of the present utility model can be used in cooperation with the object 2 to be detected to monitor the opening and closing of the container door. In order to further illustrate the principle and structure of the utility model, the preferred embodiments of the utility model will be described in detail in conjunction with the accompanying drawings.

Please refer to shown in Fig. 1, the magnetic induction distance detection device 1 of the present utility model comprises a magnetically conductive support 11, a ring magnet 12, a first cylindrical magnet 13, a magnetic induction sensor 14, a magnetically conductive shield 15 And a second cylindrical magnetic steel 16.

The magnetically permeable bracket 11 is a plate-shaped structure made of magnetically permeable materials, such as iron magnetically permeable brackets, etc. The magnetically permeable bracket 11 has a through hole 111, which is a circular hole, and A first counterbore 112 is formed at the bottom of the magnetically permeable bracket 11 below the through hole 111 . The diameter of the first counterbore 112 is slightly larger than the diameter of the through hole 111 and their central axes coincide.

The ring-shaped magnet 12 is annular in shape, and its inner diameter is preferably the same as the diameter of the through hole 111. The magnetization direction (ie, the direction of magnetic field strength) of the ring-shaped magnet 12 is a direction perpendicular to its ring plane.

The whole of the first cylindrical magnetic steel 13 is cylindrical, and its outer diameter is slightly larger than the aperture of the through hole 111 and is compatible with the aperture of the first counterbore 112. The magnetization of the first cylindrical magnetic steel 13 The direction is the direction perpendicular to the upper and lower end faces of the cylinder.

The magnetic induction sensor 14 includes a sensing detection unit 141 and a circuit conversion unit (not shown in the figure) connected thereto. The sensing detection unit 141 is a Hall sensor, and the Hall sensor can be a CS49E, SS49E, SS59ET series linear Hall sensor or the like. The Hall sensor is equipped with a Hall element inside. When the Hall element is placed in a magnetic field, due to the Hall effect, a certain potential will be generated at both ends of the Hall element. The magnitude of the generated potential depends on the strength of the magnetic field. The difference will change, so the output voltage of the output terminal of the sensing detection unit 141 will change. A magnetic field strength threshold can also be set in the circuit conversion unit connected to the sensing detection unit 141, the circuit conversion unit receives the output voltage value of the sensing detection unit 141, and the output voltage value is compared with the threshold value A switch signal is obtained by comparison.

The magnetically permeable shield 15 is a barrel-shaped structure with a closed bottom and an upward opening, the inner diameter of which is slightly larger than the outer diameter of the first cylindrical magnetic steel 13, and the center of the outer end surface of the bottom is provided with a depth of 0.5mm, The second counterbore 151 with a radius slightly larger than the outer diameter of the second cylindrical magnet 16 is used to install and fix the second cylindrical magnet 16 more accurately.

This second columnar magnet 16 is a magnet for anti-interference, and the whole is cylindrical, and the magnetization direction is also a direction perpendicular to the upper and lower end faces of the cylinder, and its outer diameter is preferably the same as that of the first columnar magnet. 13 is the same as and adapted to the size of the second counterbore 151 at the bottom end of the magnetically permeable shield 15 .

Please refer to FIG. 2 to FIG. 3 . During installation, the annular magnetic steel 12 is attached and installed on the upper surface of the magnetic permeable bracket 11 around the through hole 111 , and the top end of the first cylindrical magnetic steel 13 is embedded. Set in the first counterbore 112 on the lower surface of the magnetically permeable bracket 11, the top of the magnetically permeable shield 15 is closed and fixedly connected to the lower surface of the magnetically permeable bracket 11 so that the first cylindrical magnetic steel 13 Accommodated in the magnetic shield 15, the top of the second cylindrical magnet 16 is embedded in the second counterbore 151 on the lower end surface of the magnetic shield 15, and the ring magnet 12, the The central axes of the through hole 111, the first cylindrical magnetic steel 13, the magnetically permeable shield 15 and the second cylindrical magnetic steel 16 coincide, and the annular magnetic steel 12, the first cylindrical magnetic steel The polarity combination mode of the upper and lower end surfaces of the steel 13 and the second cylindrical magnetic steel 16 can be: 1) the upper and lower end surfaces of the ring magnetic steel 12 and the first cylindrical magnetic steel 13 are S poles and N poles respectively, and The upper and lower end faces of the second cylindrical magnet 16 are N pole and S pole respectively; 2) the upper and lower end faces of the ring magnet 12 and the first cylindrical magnet 13 are N pole and S pole respectively, The upper and lower end surfaces of the columnar magnetic steel 16 are S poles and N poles respectively. That is to say, the magnetic polarity of the upper and lower end surfaces of the ring magnet 12 is the same as the magnetic polarity of the upper and lower end surfaces of the first cylindrical magnet 13, and the magnetic polarity of the upper and lower end surfaces of the second cylindrical magnet 16 is the same as that of the first cylindrical magnet 16. The magnetic polarities of the upper and lower end surfaces of the first and second cylindrical magnetic steels are opposite. The sensing detection unit 141 of the magnetic induction sensor 14 is fixed at a position between the object 2 to be detected and the through hole 111 on the magnetically conductive support 11, and the more commonly used installation positions are as follows:

Position 1: The sensing detection unit 141 is installed in the hollow position of the ring magnet 12, and the detection plane of the sensing detection unit 141 is parallel to the ring plane where the ring magnet 12 is located, then the detection distance The object 2 is made of a magnetically conductive material or a magnetically conductive object is provided on the object 2 corresponding to the position of the magnetic induction distance detection device 1, as shown in FIG. 2 ;

Position 2: The sensing detection unit 141 is installed on the object 2 to be detected that can move along the central axis of the ring magnet 12, and the installation position corresponds to the hollow position of the ring magnet 12. The detection plane of the sensing unit 141 is parallel to the ring plane of the ring magnet 12 , as shown in FIG. 3 .

The magnetic field intensity produced by the magnetic induction distance detection device 1 of the present utility model is approximately zero at the hollow position of the ring magnet 12, and the surrounding magnetic field intensity is large; When the vertical direction is close to the detection device 1, the magnetic field strength in its surrounding space will change rapidly, and the magnetic field strength at the hollow position of the ring magnet 12 will also change rapidly, and cause the analog output of the sensing detection unit 141 ( For example, the output voltage) changes rapidly, and the circuit conversion unit connected to the sensing detection unit 141 can convert it into a distance signal after detecting the change of the analog output, or compare it with the threshold value set in the circuit conversion unit Then get a switch signal.

A specific example of the application of the detection device 1 to detect the opening and closing of the container door will be described below. When the magnetic induction distance detection device 1 is the internal structure of the sensing detection unit 141 at the installation position 1, the entirety of the magnetic induction detection device 1 can be fixed on the door frame or a door of the container; when the magnetic induction distance detection When the device 1 is the internal structure of the sensing detection unit 141 in the installation position 2, the sensing detection unit 141 of the magnetic induction distance detection device 1 can be installed on a door of the container (that is, the distance object to be detected 2 ), and the remaining parts except the sensing detection unit 141 are installed on the door frame of the container or on another door. Of course, the sensing detection unit 141 of the magnetic induction distance detection device 1 can also be installed on the door frame or a door of the container, and the rest of the magnetic induction distance detection device 1 except the sensing detection unit 141 is installed On the other door of the container. When the door is opened, the relative position between the door and the door frame or between the two doors changes, so the magnetic field strength at the position of the sensing detection unit 141 changes, and causes the sensing detection unit 141 to The output voltage changes, so the voltage value received by the circuit conversion unit changes, and after comparing the voltage value with the threshold value set inside the circuit conversion unit, the circuit conversion unit outputs a box door opening signal. And when there is malicious interference from external magnetic fields and magnetically permeable substances on the sides and back of the surroundings, due to the combined shielding effect of the magnetically permeable shield cover 15 and the second columnar magnetic steel 16 on the interfering magnetic field, the magnetic induction distance detection device 1 is still Can accurately monitor the illegal opening of the door.

The magnetic induction distance detection device 1 of the present utility model can realize the detection of the short-distance object distance by detecting the change of the magnetic field intensity, and a magnetically conductive shielding cover 15 with an anti-interference cylindrical magnetic steel is installed on the outside of the bottom end, which can effectively Resist malicious interference from external magnetic fields around the sides and back, so when used as a door switch detection device for containers, it has the advantages of high sensitivity, strong reliability and anti-interference.

However, the above descriptions are only preferred feasible embodiments of the present utility model, and do not limit the scope of protection of the present utility model. Therefore, all equivalent structural changes made by using the description of the utility model and the contents of the accompanying drawings are included in the scope of this utility model. new type of protection.

Claims (9)

1. A magnetic induction distance detecting device, which is used to monitor the opening and closing of the container box door, is characterized in that, the magnetic induction distance detecting device comprises: a plate-shaped magnetically conductive support formed with a through hole; an annular magnetic steel, the The ring-shaped magnetic steel is fixed on the upper surface of the magnetic conductive bracket around the through hole; a first cylindrical magnetic steel is located at the lower end of the through hole and fixed on the magnetic conductive support. The lower surface of the bracket; a magnetically permeable shield, the magnetically permeable shield is a barrel-shaped structure with an open top, the top of the magnetically permeable shield is closed and fixedly connected to the lower surface of the magnetically permeable bracket, and The first cylindrical magnet is housed in the magnetically permeable shield; a second cylindrical magnet is fixedly arranged on the lower end surface of the magnetically permeable shield and a magnetic induction sensor, the magnetic induction sensor includes a sensing detection unit and a circuit conversion unit electrically connected to the sensing detection unit, the sensing detection unit is arranged between the object to be detected and the through hole And detect the change of the magnetic field strength to output the corresponding distance change signal. 2. The magnetic induction distance detection device according to claim 1, wherein the inner diameter of the ring magnet is the same as the diameter of the through hole and slightly smaller than the outer diameter of the first cylindrical magnet, so The size and shape of the second cylindrical magnet and the first cylindrical magnet are the same; and the magnetization direction of the ring magnet is a direction perpendicular to the ring plane where the ring magnet is located, and the first The magnetization direction of a cylindrical magnet and the second cylindrical magnet is a direction perpendicular to the upper and lower end surfaces of the cylinder; the magnetic polarity of the upper and lower end surfaces of the ring magnet is consistent with the upper and lower end surfaces of the first cylindrical magnet. The magnetic polarities of the two cylindrical magnets are the same, and the magnetic polarities of the upper and lower end surfaces of the second cylindrical magnet are opposite to those of the upper and lower end surfaces of the first and second cylindrical magnets. 3. The magnetic induction distance detecting device according to claim 1, wherein a counterbore is provided at the center of the bottom outer end face of the magnetically permeable shield, and the top end of the second cylindrical magnetic steel is embedded in the inside the counterbore. 4 . The magnetic induction distance detection device according to claim 3 , wherein the depth of the counterbore is 0.5 mm. 5. The magnetic induction distance detecting device according to any one of claims 1 to 4, wherein the through hole is a circular hole, and the ring magnet, the through hole, and the first cylindrical magnet , the magnetically permeable shield and the second cylindrical magnetic steel are coincident in their central axes. 6. The magnetic induction distance detection device according to any one of claims 1 to 4, wherein the object to be detected is made of a magnetically conductive material or the object to be detected is provided with a magnetically conductive object, so The sensing and detecting unit is arranged in the hollow position of the ring magnet, and is parallel to the ring plane where the ring magnet is located. 7. The magnetic induction distance detection device according to any one of claims 1 to 4, wherein the sensing detection unit is arranged on the object corresponding to the hollow position of the ring magnet on the object to be detected position, and parallel to the annular plane where the annular magnetic steel is located. 8. The magnetic induction distance detection device according to claim 6, wherein the sensing detection unit is a linear Hall sensor. 9. The magnetic induction distance detection device according to claim 7, wherein the sensing detection unit is a linear Hall sensor.

Images