JP4343210B2 - Metal detector - Google Patents

Description

  In the present invention, for example, when a magnetic substance is mixed in an object to be inspected, such as raw meat, fish, processed food, medicine, etc., the mixed magnetic substance is magnetized while the object to be inspected is being conveyed. The present invention relates to a metal detection device that determines whether or not a magnetic material is mixed in an object to be inspected based on data obtained by detecting a magnetic quantity.

2. Description of the Related Art Conventionally, a metal detection device that detects the presence or absence of a magnetic material using a metal magnetization characteristic is known as a foreign material detection device that detects whether or not a foreign material is mixed in an inspection object.
Such a conventional metal detection device magnetizes a magnetic substance mixed in an object to be inspected conveyed at a predetermined interval from a conveyor disposed upstream, while the amount of magnetization is reduced. The detected value obtained by detection is compared with a reference value to determine whether it is a non-defective product or not, and a non-defective product and other defective products are selected. This metal detection device generally includes a transport unit, a magnetizing unit, a detection head unit, a magnetization amount calculating unit, a foreign matter determining unit, and a display unit. In this metal detection device, the object to be inspected conveyed from the upstream belt conveyor is conveyed by the conveyance unit and the magnetic field generated by the magnetization unit is allowed to pass, and then the amount of magnetization is detected and detected by the detection head unit. A signal is output. Based on the output detection signal, the magnetization amount calculation unit calculates the magnetization amount of the magnetic material mixed in the inspection object and outputs an electrical signal to the foreign matter determination unit. The foreign matter determination unit outputs the electrical signal that is output. Based on the above, it is determined whether or not a magnetic material is mixed in the object to be inspected.
When magnetizing the magnetic material mixed in the object to be inspected, the smaller the distance between the upper surface of the object to be inspected and the lower surface of the detecting head, the more the amount of magnetization can be increased, and the detection accuracy in the detecting head portion is increased. . Further, when the amount of magnetization of the magnetized magnetic material is detected by the detection head unit, the magnetization amount can be detected with higher accuracy as the distance between the upper surface of the object to be inspected and the lower surface of the detection head unit is smaller.
For this reason, an adjustment mechanism is provided so that the gap between the upper surface of the object to be inspected, the lower surface of the magnetized part, and the lower surface of the detection head part is reduced by interlocking the magnetized part and the detection head part according to the height of the object to be inspected. The installation interval is adjusted (for example, see paragraph number [0017] in Patent Document 1).

JP 2005-337996 A

However, in the apparatus described in Patent Document 1, the distance between the upper surface of the conveyor belt and the magnetized section and the lower surface of the detection head section in the adjusted transport section can be changed. The distance from the lower surface of the head part is not displayed. Therefore, the operator can easily grasp the distance between the adjusted upper surface of the conveyor belt and the magnetized portion and the lower surface of the detection head, that is, whether the height of the magnetized portion and the detected head is appropriate. There was a problem that could not.
In addition, when the distance between the adjusted upper surface of the transport belt and the lower surface of the magnetized portion and the detection head portion is too small, that is, when the height of the magnetized portion and the detection head portion is too low, Has a problem that it cannot pass through the magnetized portion. On the other hand, if the height of the magnetized part and the detection head part are too high, a detection error of the magnetization amount in the detection head part may occur, which may cause a false detection, resulting in a decrease in detection accuracy and a decrease in inspection efficiency. There was also a problem of doing.

  SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the conventional problems as described above and achieve the following objects. That is, the present invention can detect the distance between the upper surface of the conveyor belt and the lower surface of the detection head, and can set the height of the detection head suitable for the height of the object to be inspected. An object of the present invention is to provide an excellent metal detection apparatus capable of detecting the above-described metal with high inspection efficiency.

In the metal detector according to the present invention, in order to achieve the above object, (1) a conveying means for conveying an object to be inspected, and a magnetic material contained in the object to be inspected being conveyed by the conveying means are magnetized. Magnetizing means, detecting means for detecting the amount of magnetization of the magnetic material magnetized by the magnetizing means, and determining the quality of the inspection object based on the amount of magnetization detected by the detecting means In a metal detection apparatus comprising: a determination unit; and an elevating unit that elevates and lowers both the magnetizing unit and the detection unit in accordance with the height of the inspection object, the metal detection device is predetermined according to the type of the inspection object. A data memory for storing the height H and the reference interval KS, a distance calculating means for detecting a distance L from the upper surface of the conveying belt of the conveying means to the lower surface of the detecting head part of the detecting means, and the distance calculating means Detect Or the distance L and the stored in the data memory based on the height H determined spacing S to the detection head bottom surface from the top surface of the inspection object, the distance S is within the range of the reference interval KS The interval determination means for determining whether or not, and the display means for displaying the interval determination result determined by the interval determination means.

With the above configuration, in the metal detection device according to the present invention, when the object to be inspected is conveyed by the conveying means, if the magnetic object is mixed in the object to be inspected, the magnetizing means while the object is being conveyed. Magnetized and the object to be inspected passes through the detection means. The detection means detects the amount of magnetization of the magnetic material mixed in the inspection object passing therethrough and outputs a detection signal. When the detection signal is output, the determination unit determines whether or not a magnetic material is mixed in the inspection object based on the detected amount of magnetization. Further, the magnetizing means and the detecting means are operated so that the operator operates the lifting means according to the height of the object to be inspected, and the distance between the upper surface of the object to be inspected and the lower surfaces of the magnetizing means and the detecting means is reduced. Both are raised and lowered.
When both the magnetizing means and the detecting means are moved up and down, the distance calculating means detects the distance L from the upper surface of the conveying belt of the conveying means to the lower surface of the detecting head of the detecting means, and the voltage signal corresponding to the distance L is detected by the distance calculating means. Is output. When the distance calculation unit receives the output voltage signal, the distance calculation unit calculates a value of the distance L based on the voltage signal and outputs the calculated value of the distance L to the interval determination unit. When the interval determining means receives the value of the distance L, the interval determining means subtracts the height H of the inspected object that is determined in advance corresponding to the type of the inspected object and stored in the data memory from the distance L. (LH) is obtained as the interval S. Next, two reference values of a lower limit value and an upper limit value that are stored in the data memory and constitute a reference interval KS that serves as a reference for determination are read out, and the reference value and interval S of each of the read lower limit value and upper limit value are read out. Are compared. When the interval determination means determines that the interval S exceeds the lower limit value and is less than the upper limit value, the interval determination result is output to the display means and the display means displays that the interval S is normal.
When the display means displays that the interval S is normal, the operator can easily grasp that the adjusted interval is appropriate. In addition, the interval after adjustment as in the conventional metal detection device is not too small or too large, and the amount of magnetization in the detection means is detected at an appropriate interval after adjustment. The accuracy is improved and the inspection efficiency is improved.

Moreover, in the metal detection device of (1) according to the present invention, (2) having a transport control means for controlling the transport means, and according to the interval determination result, the transport control means You may make it control at least any one of a conveyance speed and a conveyance direction.
With the above configuration, in the metal detection device according to the present invention, for example, when the interval determination unit determines that the interval S is less than the lower limit or exceeds the upper limit, the interval determination result is conveyed. It is output to the control means. When the conveyance control means receives the interval determination result, it instructs the conveyance means to reduce the conveyance speed, and the conveyance means reduces the conveyance speed based on the command. When the conveying means is lowered, if the height of the detection head portion is too high, the inspection object can be more reliably magnetized, and the detection accuracy by the detection head portion is prevented from being lowered. Further, if the conveying means is stopped or the conveying direction is reversed, it is possible to prevent the object to be inspected from colliding with the magnetized portion when the height of the detection head portion is too low.

On the other hand, in the metal detection device of (1) or (2) according to the present invention, (3) when the interval S is not within the range of the reference interval KS, the interval determining means is An uninspected object notification signal for notifying an uninspected object that has not been inspected may be output.
With the above configuration, in the metal detection device according to the present invention, when the interval determination unit determines that the interval S is less than the lower limit value or exceeds the upper limit value, the inspection object is an uninspected object. A notification signal indicating that there is something is output. For example, when an uninspected object notification signal is output and displayed on the display means, the operator can easily grasp that the inspected object is an uninspected object. When output to the sorting unit, the inspection object is selected as an uninspected object, and appropriate measures such as re-inspection are performed.

In the metal detection device of (3) according to the present invention, (4) the display means is an uninspected object that has not been inspected yet upon receiving the uninspected object notification signal. May be displayed.
With the above configuration, in the metal detection device according to the present invention, when the interval determination unit determines that the interval S is less than the lower limit value or exceeds the upper limit value, the inspection object is an uninspected object. It is displayed on the display means. When such a display is made, the operator can easily grasp that the cause of the change in the speed of the transport means by the transport means is an abnormal height of the detection head unit.

In the metal detectors (2) to (4) according to the present invention, (5) when the interval S is not within the reference interval KS may be displayed on the display means. .
With the above configuration, in the metal detection device according to the present invention, when the interval determination unit determines that the interval S is less than the lower limit value or exceeds the upper limit value, the control content of the transport control unit is Displayed on the display means. When such a display is made, the operator can easily grasp that the cause of the change in the speed of the transport means by the transport means is an abnormal height of the detection head unit.

  According to the metal detection apparatus of the first aspect, since the display means displays that the interval S is normal, the operator can easily grasp that the interval S after adjustment is appropriate. In addition, since the interval after adjustment as in the conventional metal detection device is not too small or too large, the amount of magnetization in the detection head unit is detected at an appropriate interval after adjustment. Detection accuracy is improved, there is no false detection, and inspection efficiency is improved.

  Further, according to the metal detection device of the second aspect, when it is determined that the interval S is not appropriate, for example, since the conveying means is lowered, when the height of the detection head portion is too high, the inspection object is moved to the inspection object. Thus, it is possible to surely prevent the detection accuracy from being lowered or erroneously detected by the detection head unit. Moreover, since the conveying means is stopped or the conveying direction is reversed, it is possible to prevent the object to be inspected from colliding with the magnetized portion when the height of the detection head portion is too low.

  Further, according to the metal detection device of claim 3, since an uninspected object notification signal indicating that the object to be inspected is an uninspected object is output, in addition to the effect of claim 1, for example, an uninspected object notification When the signal is output and displayed on the display means, the operator can easily grasp that the inspection object is an uninspected object. When output to the sorting unit, the inspection object is selected as an uninspected object, and appropriate measures such as re-inspection can be taken. As a result, inspection accuracy and inspection efficiency are greatly improved.

  In addition, according to the metal detection device of the fourth or fifth aspect, at least one of the control contents such as the inspection object being uninspected or the interval S being abnormal and the speed adjustment of the conveying means is displayed. In addition to the effect of the first aspect, the operator can easily grasp that the initially set height or the changed height of the detection head unit is abnormal. Furthermore, it can be easily grasped that the cause of the control of the conveying means is an abnormal height of the detection head unit. As a result, inspection accuracy and inspection efficiency are greatly improved.

Hereinafter, an embodiment of a metal detection device according to the present invention will be described with reference to the drawings.
FIGS. 1-10 has shown an example of embodiment of the metal detection apparatus based on this invention.

  As shown in FIGS. 1 and 2, the metal detection device 1 includes an apparatus main body 2, a conveyance unit 3 as a conveyance unit, a magnetization unit 4 as a magnetization unit, and a detection head unit 5 as a detection unit. And the sorting unit 6.

  The metal detector 1 is installed at the rear end portion of the belt conveyor 48 that constitutes a part of the production line, and a magnetic substance is mixed into the inspection object W that is sequentially conveyed in the direction of arrow A at a predetermined interval. If the magnetic material is magnetized, the detected value obtained by detecting the magnetization amount is compared with the reference value recorded in the data memory 24, and the obtained detected value exceeds the reference value. It is determined whether or not there is a non-defective product if it is less than the reference value, and a product that exceeds the reference value is determined as a defective product mixed with a magnetic substance.

  The apparatus main body 2 includes a conveyance control unit 7, a foreign object detection unit 8 as a detection unit, a distance detection unit 9 as a distance calculation unit, a display unit 11, an operation unit 12, and a storage for storing these units. It is comprised by the housing | casing 2a and the mount frame 2b which supports the raising / lowering part 10 as a conveyance part 3, the magnetizing part 4, the detection head part 5, and the raising / lowering means.

The conveyance unit 3 includes two pulleys 3a and 3b and an endless conveyance belt 3c wound around these pulleys.
The transport unit 3 is configured to transfer various inspected objects W such as raw meat, fish, processed foods, and medicines that flow in the direction of the arrow A from the belt conveyor 48 based on commands from the transport control unit 7. It is conveyed at (linear velocity: m / min). In the transport unit 3, first, the object W to be transported is passed through the magnetic field generated by the magnetizing unit 4, then passed through the lower part of the detection head unit 5, and further transported to the sorting unit 6. It is like that.

The magnetized portion 4 includes a permanent magnet and a support member that supports the permanent magnet. With the above configuration, a magnetic field is formed by the permanent magnet, and when the inspection object W conveyed by the conveyance belt 3c passes the magnetic field, the magnetic object mixed in the inspection object W is magnetized. Yes. Such a configuration of the magnetized portion 4 may be a known one, for example, one described in JP-A-2005-337996.
Specifically, as shown in FIGS. 1 and 2, the permanent magnet is disposed on the upper portion of the transport belt 3 c, the upper support member that supports the permanent magnet, and the lower portion of the transport belt 3 c (not shown). It is comprised by the lower side supporting member which supports a permanent magnet and a permanent magnet. The permanent magnet disposed on the upper portion may be composed of one rectangular shape larger than the lateral width of the conveyor belt 3c, or a plurality of permanent magnets. Also, the polarity of the surface portion of the permanent magnet supported by the upper support member on the side of the conveyor belt 3c and the polarity of the surface portion of the permanent magnet supported by the lower side support member on the side of the conveyor belt 3c are different. Are arranged. For example, when the surface portion of the permanent magnet supported by the upper support member on the side of the conveyor belt 3c is N-pole, the polarity of the surface portion of the permanent magnet supported by the lower support member on the side of the conveyor belt 3c is S-pole. Are arranged as follows.

  In this way, since the DC magnetic field (A / m) is formed between the N pole of the permanent magnet of the upper support member and the S pole of the permanent magnet of the lower support member, the object W to be inspected is the transport belt. When the magnetic material is mixed in the inspection object W when it is transported to 3c and passes through the magnetic field, the magnetic material becomes magnetized and residual magnetism is generated, so-called magnetized. Even when the object W to be inspected is packaged with aluminum, the magnetic material is magnetized and residual magnetism is generated, so that it is particularly suitable for an aluminum package. Even if the inspection object W is further transported and deviates from the magnetic field, the magnetic flux is released to the outside from the magnetized magnetic object. The amount of magnetic flux is represented by magnetic flux density (G) per unit area. Also, the smaller the distance between the permanent magnet supported by the upper support member and the magnetic material, the stronger the magnetic material is affected by the magnetic field, so the amount of magnetic flux of the magnetic material increases. Therefore, a gap (LH) resulting from the difference between the height H of the inspection object W shown in FIG. 3 and the distance L between the detection head portion lower surface 5a and the conveyor belt upper surface 3d shown in FIG. The smaller the value, the better.

  Further, any arrangement may be used as long as such a magnetic material is magnetized. For example, since the magnetic field can be generated in the vicinity of the upper side of the conveyor belt 3c only by the N pole and the S pole of the permanent magnet supported by the upper support member, the magnetized portion 4 can be formed only by the permanent magnet supported by the upper support member. It may be configured.

  The detection head unit 5 includes a detection coil, a DC amplification circuit, an integration circuit, and an analog / digital conversion circuit. As shown in FIGS. 1 and 2, the coil portion is arranged on the upper portion of the conveyor belt 3c to form an upper search coil that forms a closed circuit, an upper search coil support member that supports the upper search coil, and an unillustrated conveyor belt 3c. A lower search coil that is disposed on the lower side and forms a closed circuit, and a lower search coil support member that supports the lower search coil. The upper search coil and the lower search coil are arranged at positions away from the permanent magnet of the magnetized portion 4 to such an extent that the influence of the magnetic field generated by the permanent magnet constituting the magnetized portion 4 can be ignored. In addition, the upper search coil and the lower search coil are disposed so as to face each other with the conveyance belt 3c interposed therebetween, but the configuration in which the upper search coil and the lower search coil are disposed at positions shifted in the conveyance direction is hindered. Absent.

  When the inspection object W is conveyed to the conveyance belt 3c and passes through the space formed by the upper search coil and the lower search coil, if the inspection object W is mixed with the magnetic object, the magnetized portion 4 Since the magnetic flux is released to the outside from the magnetic material magnetized with residual magnetism, the magnetic flux changes in the upper search coil and the lower search coil, and the voltage is induced by the magnetic flux change. ing. Each induced voltage is time-integrated by an integration circuit to obtain a quantitative value, which is then amplified by a DC amplification circuit and a low-frequency signal component is extracted as an analog voltage signal through a low-pass filter. As a result, noise is removed. The analog signal from which noise has been removed is output to an analog-digital conversion circuit, converted into a digital signal, and output to the arithmetic processing circuit 21.

  As described above, in the present embodiment, the intrusion sensor that detects that the inspection object W has entered the detection region in the vicinity of the detection head unit 5 is not provided. An intrusion sensor may be provided upstream of the detection head unit 5 so that when the detection head unit 5 detects a magnetic substance, the detection head unit 5 is operated when the intrusion sensor detects the intrusion of the inspection object W. Good. As an intrusion sensor, for example, it has a light source unit that emits a light beam and a light receiving unit that receives the light beam emitted by the light source unit, and the light receiving unit cannot receive the light beam while the light source unit emits the light beam. It may be configured by a so-called projector / receiver that detects this and detects the entry of the inspection object W.

The sorting unit 6 includes a sorting mechanism unit (not shown) and a transport conveyor 6a. The conveyor 6a includes a pulley 6b, a pulley (not shown) arranged to face the pulley 6b, and an endless conveyor belt 6c wound around these pulleys.
The sorting mechanism unit is configured by any sorting mechanism such as a flipper mechanism, an air jet mechanism, or a dropout mechanism, for example. For example, in the air jet mechanism, while the inspection object W transported from the upstream transport unit 3 is transported in the direction of arrow B by the transport conveyor 6a, the jet air is covered based on the determination result of the foreign matter determination circuit 22. The inspection object W is sprayed onto the inspection object W, and the inspection object W is moved on the conveyor 6a, and the inspection object W is sorted by distinguishing between the moved object and the non-moving object, or from the conveying conveyor 6a. Sorting is performed by removing the inspection object W.

  The conveyance control unit 7 includes a drive motor 27 and a control circuit 28. The control circuit 28 controls the start, stop, rotation direction, and rotation speed of the drive motor 27 based on information input from the operation unit 12 and information output from the foreign matter determination circuit 22.

  The foreign object detection unit 8 includes an arithmetic processing circuit 21, a foreign object determination circuit 22, a distance calculation circuit 23, a data memory 24, and an interval determination circuit 25. With the above configuration, the distance L of the detection head unit 5 is set to an appropriate distance, and it is detected and determined whether or not a magnetic substance is mixed in the inspection object W. The configuration and method for detecting and determining the presence or absence of a magnetic substance may be a known one or a method described in JP-A-2006-58113. For example, when a magnetic substance is mixed in the inspection object W, a digital signal output from the detection head unit 5 is received and recorded in the data memory 24 with the value of the received digital signal and a reference for determination A difference from the value of the digital signal is calculated, and whether or not this difference exceeds a predetermined reference value made of the digital signal is compared. It may be determined that the magnetic material is not mixed in the inspection object W when it is determined that the magnetic material is mixed and the predetermined reference value is not exceeded. The determination result is output to the selection unit 6 to select a non-defective product in which no magnetic material is mixed and a defective product in which the magnetic material is mixed. Moreover, it outputs to the display part 11 and a determination result is displayed on a display screen. For example, the determination result is displayed together with the type, lot number, individual number, etc. of the inspection object W.

  The arithmetic processing circuit 21 includes an integrated circuit (Integrated Circuit) for arithmetic processing of signals, an electronic circuit such as a CPU (Central Processing Unit), and a storage medium such as a RAM (Random Access Memory) for storing arithmetic processing results. The With such a configuration, the reference digital signal that is recorded in the data memory 24 and serves as a reference is read, and the difference between the value of the digital signal received from the inspection head unit 5 and the value of the reference digital signal is calculated and calculated. The value of the difference digital signal is output to the foreign matter determination circuit 22.

  The foreign matter determination circuit 22 is composed of an integrated circuit for determining the presence or absence of foreign matter. With such a configuration, a difference digital signal composed of a digital signal output from the arithmetic processing circuit 21 is received, a reference difference digital signal recorded in advance in the data memory 24 and used as a reference for determination is read out and obtained from the object W to be inspected. The value of the difference digital signal and the value of the reference difference digital signal are compared, and it is determined whether or not the value of the difference digital signal of the object W exceeds the value of the reference difference digital signal. The determined result is output to the sorting unit 6, and a non-defective product whose value of the difference digital signal of the inspection object W does not exceed the value of the reference difference digital signal is selected. Further, if necessary, the determination result is output to the display unit 11 and displayed on the display screen, and further output to the data memory 24 to record the determination result for each inspection object W. Moreover, it is output also to the conveyance control part 7, and is used as control information, such as adjustment of the conveyance speed of the conveyance part 3, a stop of conveyance, and change of a conveyance direction.

  The distance calculation circuit 23 is configured by a known arithmetic circuit such as an integrated circuit, and based on the voltage signal output from the distance detection unit 9, the distance L from the conveyance belt upper surface 3d to the detection head unit lower surface 5a shown in FIG. It comes to calculate. The calculated distance L is output to the interval determination circuit 25.

  The data memory 24 is composed of a recording medium or the like, and records various data and inspection conditions set in advance corresponding to the type of the inspection object W. For example, the height H (mm), size product name and weight of the inspection object W shown in FIG. 3, the linear velocity (m / min) of the conveying belt 3c, the length (mm) of the conveying unit 3 in the conveying direction, A reference digital signal and a reference difference digital signal that are used as a reference for determining whether or not a magnetic substance is mixed in the inspection object W, determination results and determination data of each inspection object W, and the like are recorded. .

The interval determination circuit 25 is configured by a known calculation and comparison circuit such as an integrated circuit, and based on the value of the distance L output from the distance calculation circuit 23 shown in FIG. 2, first, as shown in FIG. A gap (LH) obtained by subtracting the height H of the inspection object W from the distance S is obtained as the interval S. Next, it is determined whether or not the obtained interval S is within the range of the reference interval KS.
The reference interval KS is composed of a reference range defined by two reference values, an upper limit value Lmax and a lower limit value Lmin that allow the interval S, and is stored in the data memory 24.
With the above configuration, the interval determination circuit 25 obtains the interval S and reads the upper limit value Lmax and the lower limit value Lmin stored in the data memory 24. Next, the calculation and comparison circuit compares the interval S with the upper limit value Lmax, compares the interval S with the lower limit value Lmin, and determines whether the interval S exceeds the upper limit value Lmax or not. Whether it is less than or not is determined.

  When the interval determination circuit 25 determines that the interval S is not within the range of the reference interval KS, the interval determination circuit 25 notifies that the inspection object W is an uninspected object that has not been inspected yet. An object notification signal is output. For example, when an uninspected object notification signal is output to the display unit 11 and the contents are displayed on the display screen, the operator can easily grasp that the inspected object W is an uninspected object. When output to the sorting unit 6, the inspection object W is selected as an uninspected object, and appropriate measures such as re-inspection are performed.

  The interval determination result is output to the control circuit 28 in the transport control unit 7 and used as control information for adjusting the transport speed of the transport unit 3, stopping the transport, changing the transport direction, and the like on the display unit 11 as necessary. It is output and displayed on the display screen so that the operator can visually recognize it. Further, the interval determination result is output to the data memory 24 and recorded as an interval determination result for each inspection object W.

The height H of the inspection object W shown in FIG. 3 is determined by the type of the inspection object W and the like, and is input at the time of initial setting, and the set height H is a known height measuring device and height. It can be measured by a measuring method. For example, the height is measured by setting two points in the vertical direction on the lower and upper surfaces of the workpiece W, irradiating each laser slit toward the two points from an oblique 45 degree direction, and measuring the displacement of each slit. Alternatively, a method may be used in which the inspection object W is imaged with a laser measuring instrument, a CCD (Charge Coupled Device), or the like, and the height is calculated by image processing.
The measured height H of the inspection object W is preferably calculated by a statistical method using an arithmetic mean, standard deviation, or the like for every predetermined number of measurement. By improving the accuracy of the height H, the accuracy of the interval S can be further improved.

As shown in FIG. 3A, the distance detection unit 9 includes a rod portion 9a, a brush portion 9b, a brush support portion 9c, and a connection portion 9d. One end of the rod portion 9a is attached to a rod attachment portion 2c provided in the apparatus main body 2 and the other end is attached to a rod attachment portion 2d provided in the apparatus main body 2 so that a resistance R is integrally formed. ing. One end of the brush support portion 9c is fixed to the detection head portion 5, and the other end portion is fixed to the brush portion 9b to support the brush portion 9b. The connecting portion 9d is made of a lead wire, and electrically connects the distance detecting portion 9 and the distance calculating circuit 23. The distance detecting unit 9, as shown in FIG. 3 (B), one end of the resistor R and the other end portion to the terminal T ₁ is connected to a T _2, the brush B is connected to the terminal T _3.

With the above configuration, as shown in FIG. 3 (B), the brush B is slid in the arrow direction in contact with the resistor R, so that a voltage corresponding to the sliding position of the brush B is output from the T ₁ It has become. That is, as shown in FIG. 3A, when the brush support portion 9c and the brush portion 9b slide in the arrow direction of the rod portion 9a, a voltage corresponding to the sliding position of the brush portion 9b is generated, and the generated voltage Is output to the distance calculation circuit 23 via the connecting portion 9d. Accordingly, when the detection head unit 5 is lifted by the lifting / lowering unit 10, the brush unit 9b is lifted via the brush support portion 9c, and when the detection head portion 5 is lowered, the brush portion 9b is lowered via the brush support portion 9c. A voltage signal corresponding to the amount of decrease is output to the distance calculation circuit 23. As shown in FIG. 4, the horizontal axis represents the distance L between the upper surface 3d of the conveying belt and the lower surface 5a of the detection head, and the vertical axis represents the voltage output from the distance detector 9, and the voltage output as the distance L increases. Since the distance L also increases linearly, the distance L and the voltage are in a proportional relationship. Corresponding to the adjustment range of the distance L, the voltage also changes within a predetermined range.

  Specifically, the distance detection unit 9 can be configured by a linear potentiometer. The linear potentiometer is configured so that the change in resistance with respect to the amount of movement is linear. The position of the movable electrode is detected by applying a reference voltage to both ends of the two fixed electrodes and measuring the voltage of the movable electrode. It has come to be. The detected voltage is output to the distance calculation circuit 23 as a voltage signal.

  As described above, in the present embodiment, the distance detection unit 9 is configured by a linear potentiometer. However, in the present invention, the distance detection unit 9 may be any other publicly known as long as the distance L can be detected. You may comprise by the measurement sensor of. For example, by setting two positions in the vertical direction of the upper surface 3d of the conveyor belt and the lower surface 5a of the detection head, irradiating each laser slit from the oblique 45 degree direction to two points, and measuring the displacement of each slit, the height A laser measuring instrument that measures the amount of vertical movement of the detection head unit 5 and a rotary potentiometer that detects the distance L by detecting the rotation angle, and a microscope that has an objective lens in the detection head unit 5 It may be configured by a microscope or the like that attaches and focuses at two locations before and after the movement of the detection head unit 5 and detects the focal length of each focus and detects the difference as a height.

As shown in FIGS. 5 and 6, the elevating means 10 includes a connecting portion 15 as a connecting member for connecting the magnetized portion 4 and the detection head portion 5, and an elevating mechanism portion 16 connected by the connecting portion 15 and the slider 34. And a guide portion 17 as a guide member and tension coil springs 13 and 14 as balance members.
With the above configuration, when the elevating mechanism 16 moves in the direction of arrow A, the connecting portion 15 moves in the direction of arrow A via the slider 34. When the connecting portion 15 moves, the tension coil springs 13 and 14 balance the magnetized portion 4 and the detection head portion 5 with the slider 34 as a fulcrum, so that no eccentric load is generated in the lifting mechanism portion 16. ing. Further, the guide portion 17 prevents the lifting mechanism portion 16 from being biased.

The connecting portion 15 is made of, for example, a sheet metal having a bent structure, and one end portion is fixed to the magnetized portion 4 and the other end portion is fixed to the detection head portion 5. Further, as shown in FIGS. 5 and 6, the connecting portion 15 has a slider 34 that is coupled to the lifting mechanism portion 16, a through hole 15 a, and spring support portions 15 b and 15 c that support the tension coil springs 13 and 14. Yes.
With the above configuration, as shown in FIG. 5, the fulcrum of the slider 34 is P, the center of gravity of the magnetized portion 4 is G ₁ , the horizontal distance from G ₁ to P is WL ₁ , and the load applied to G ₁ is W ₁ , The center of gravity of the detection head unit 5 is G ₂ , the horizontal distance from G ₂ to P is WL ₂ , the load applied to G ₂ is W ₂ , the horizontal distance from the central axis of the tension coil spring 13 to P is FL ₁ , and the tension coil When the horizontal distance from the central axis of the spring 14 to P is FL ₂ ,
Rotational moment (WL ₁ × W ₁ ) (Nm) obtained by multiplying WL ₁ and W ₁ ,
Rotational moment (WL ₂ × W ₂ ) (Nm) multiplied by WL ₂ and W ₂ ,
Rotational moment (FL ₁ × F ₁ ) (Nm) obtained by multiplying FL ₁ and F ₁ ,
Rotational moment (FL ₂ × F ₂ ) (Nm) multiplied by FL ₂ and F ₂ ,
The tension coil springs 13 and 14 are arranged so as to balance each other, that is, so as to satisfy the following expression.
(WL ₁ × W ₁ ) ≈ (WL ₂ × W ₂ ) − (FL ₁ × F ₁ ) − (FL ₂ × F ₂ )
With the above configuration, the magnetized portion 4 and the detection connected by the connecting portion 15 without causing an offset load on the elevating portion 10 in a state where the magnetized portion 4 and the detection head portion 5 are balanced in the horizontal direction. The head unit 5 can be raised and lowered.

The extension coil springs 13 and 14 are constituted by extension coil springs having hook portions on arcs at both ends. The tension coil springs 13 and 14 are arranged in such a manner that the above formula, (WL ₁ × W ₁ ) ≈ (WL ₂ × W ₂ ) − (FL ₁ × F ₁ ) − (FL ₂ × F ₂ ) is satisfied. The wire diameter, the average coil diameter, the free length when no load is applied, the effective number of turns, the total number of turns and the spring constant are set.
Further, the tension coil springs 13 and 14 are made of stainless steel or the like, and may be the same spring or different springs.
As shown in FIG. 5, the tension coil springs 13 and 14 have one end engaged with the spring support portions 15 b and 15 c in the connecting portion 15, and the other end engaged with a part of the gantry 2 b in the apparatus main body 2. By combining, the tensile urging force acts in the directions F ₁ and F _2, and acts in a direction that cancels out the load W ₂ of the detection head unit 5.

As described above, in the present embodiment is configured by the coil spring 13 and 14 pull the balance member, the present invention is in the lifting unit 10, the biasing force of the balancing member acts on F ₁ and F ₂ directions As long as it is configured so as to satisfy the above formula, it may be a compression coil spring, a leaf spring, a hydraulic cylinder, or other elastic body.

As shown in FIG. 7, the elevating mechanism unit 16 includes a linear guide 30, a handle 31, a holder 32 that holds the handle 31, a ball screw rod 33, and a slider 34.
The linear guide 30 is constituted by a box-shaped housing having an opening on one side surface, and an upper plate 30a is fixed to one end surface portion on the handle 31 side, and a lower plate 30b is fixed to the other end surface portion. The one end surface portion on the handle 31 side and the upper plate 30 a are formed with threaded holes that pass therethrough, and are screwed into screws formed on the ball screw rod 33. The other end surface portion and the lower plate 30 b are also formed with bottomed screw holes and are screwed into screws formed on the ball screw rod 33.

  The slider 34 is formed with a threaded hole penetrating in the center, and is screwed with a screw formed on the ball screw rod 33. Both side surfaces of the slider 34 in the direction perpendicular to the axial direction of the ball screw rod 33 are engaged with both inner surfaces of the housing of the linear guide 30 and each engaging portion has a slight clearance, and the slider 34 slides in the direction of the arrow. It comes to move. Further, a screw hole 34 a is formed in the side surface of the slider 34 on the opening surface side of the linear guide 30, and the bolt 34 b is inserted into the washer 34 c and the through hole 15 a to fix the connecting portion 15 to the side surface of the slider 34. Thus, the connecting portion 15 is fixed to the linear guide 30.

  With the above configuration, for example, when the handle 31 is rotated clockwise (clockwise) as indicated by an arrow, the ball screw rod 33 is rotated and the slider 34 is raised in the direction of the arrow, whereby the connecting portion 15 is raised and the handle is raised. When 31 is rotated counterclockwise (counterclockwise), the ball screw rod 33 rotates and the slider 34 descends in the direction of the arrow so that the connecting portion 15 descends.

  As shown in FIG. 8, the lifting mechanism unit 16 may be configured as a lifting mechanism unit 40 instead of the lifting mechanism unit 16. The elevating mechanism unit 40 includes a belt driving unit 41, a linear guide 50, a ball screw rod 51, and a slider 52.

  The linear guide 50 is constituted by a box-shaped housing having an opening on one side surface, and an upper plate 50a is fixed to one end surface portion facing the belt driving portion 41, and a lower plate 50b is fixed to the other end surface portion. The one end surface portion on the side facing the belt driving portion 41 and the upper plate 50a are formed with a bottomed screw hole so as to be screwed into a screw formed on the ball screw rod 51. The other end surface portion and the lower plate 50b are formed with threaded holes penetrating the screw and the screw formed on the ball screw rod 51.

  The slider 52 is formed with a threaded hole penetrating in the center and is screwed with a screw formed on the ball screw rod 51. Both side surfaces of the slider 52 in the direction perpendicular to the axial direction of the ball screw rod 51 are engaged with both inner side surfaces of the housing of the linear guide 50. Each engaging portion has a slight clearance, and the slider 34 slides in the direction of the arrow. It comes to move. Further, a screw hole 52 a is formed in the side surface of the slider 52 on the opening surface side of the linear guide 50, and the bolt 52 b is inserted through the washer 52 c and the through hole 15 a to fix the connecting portion 15 to the side surface of the slider 52. Thus, the connecting portion 15 is fixed to the linear guide 50.

The belt drive unit 41 includes a servo motor 41a, pulleys 41b and 41c, and an endless timing belt 41d wound around these pulleys.
With the above configuration, for example, when the servo motor 41a is rotated clockwise (clockwise), the pulley 41b is rotated clockwise, the pulley 41c is rotated clockwise via the timing belt 41d, and the ball screw rod 51 is rotated. Rotate clockwise. When the ball screw rod 51 rotates clockwise, the slider 52 rises along the linear guide 50 together with the connecting portion 15, and when the servo motor 41 a rotates counterclockwise (clockwise), conversely, the connecting portion 15 together with the slider 52. Is going to descend. Further, by inputting numerical values of the distance L between the magnetizing unit 4 and the detection head unit 5 from the operation buttons of the operation unit 12, the control unit (not shown) drives the servo motor 41a so that the elevating mechanism unit has a predetermined distance L. 40 can be operated.

  As described above, in the present embodiment, both the linear guide 30 in the elevating mechanism unit 16 and the linear guide 50 in the elevating mechanism unit 40 are configured by a box-shaped housing having an opening on one side surface. May be configured by a box-shaped casing provided with a lid made of a plate material, and closing one side surface of the opening with a lid and having no opening. In this case, a through hole is formed in the lid so that the linear guides 30 and 50 can be raised and lowered. For example, the connecting portion 15 is fixed to the linear guide 30 by passing the bolt 34b through the washer 34c and the through hole 15a and further fixing the connecting portion 15 to the side surface of the slider 34 through the through hole formed in the collar and the lid. May be. With this configuration, the collar can move up and down the through hole of the lid, and the connecting portion 15 can be raised and lowered even in a box-shaped housing without an opening.

  As shown in FIGS. 5 and 6, the guide portion 17 includes a rod portion 17 a formed integrally with the connecting portion 15, and guide roller portions 17 b and 17 c that are rotatably provided on the mount 2 b in the apparatus main body portion 2. , 17d, 17e. The guide roller portions 17b, 17c, 17d, and 17e are made of a resin roller, a bearing, and the like that rotate smoothly. The guide roller portions 17b and 17c are provided on one side of the rod portion 17a in the up-and-down direction, and the guide roller is provided on the other side. Parts 17d and 17e are arranged. With the above configuration, when the rod portion 17a moves up and down with the lifting and lowering portion 10, the guide roller portions 17b, 17c, 17d, and 17e move up and down smoothly without being shaken in the horizontal direction. As a result, the elevating unit 10 can move up and down more smoothly.

  As shown in FIG. 1, the display unit 11 is provided at the upper end of the housing 2 a and is configured by a display device such as a liquid crystal display, for example. The display unit 11 includes a distance L between the magnetized unit 4 and the detection head unit 5, an interval S obtained by the interval determining circuit 25, an interval determination result of the interval determining circuit 25, adjustment information of the conveying speed of the conveying unit 3, and a conveying direction. Conversion information, conveyance stop information, that the inspection object W is an uninspected object, the product name, size and weight of the inspection object W, inspection conditions set in advance corresponding to the type of inspection object W, inspection Individual difference digital signals obtained from the object W, reference difference digital signals recorded in the data memory 24, detection results detected by the foreign matter detection unit 8, and the like are displayed as necessary.

  As shown in FIG. 1, the operation unit 12 may be provided together with the display unit 11 at the upper end portion on the transport unit 3 side of the apparatus main body unit 2, and may be formed as a touch panel on the lower part of the display screen of the display unit 11. . Further, a screen switching button may be displayed on the operation unit 12 displayed as a touch panel, and an input operation unit including an input button may be displayed on a part of the display screen of the display unit 11 by touching the screen switching button. . Predetermined information such as the distance L between the magnetizing unit 4 and the detection head unit 5 and the linear velocity of the conveyor belt 3c can be input from the input operation unit.

  In the metal detection apparatus 1 according to the present embodiment, a CPU (Central Processing Unit) (not shown) that controls each component, an OS (Operating System) that starts the CPU, other programs, control parameters, and the like are stored. ROM (Read Only Memory), RAM (Randam Access Memory) for storing the execution code and data of the OS and applications used for the operation of the CPU, and EEPROM for storing application software and predetermined data in a nonvolatile and rewritable manner ( (Electrically Erasable Programmable ROM), an interface for inputting and outputting predetermined signals, and a bus (not shown) for connecting these components may be provided. . For example, the transport unit 3, the magnetizing unit 4, the detection head unit 5, the sorting unit 6, the transport control unit 7, the foreign matter detection unit 8, the distance detection unit 9, the lifting unit 10, the display unit 11, and the operation unit in the metal detection device 1. Each component such as 12 may be operated by a CPU. A control program corresponding to each component stored in the apparatus main body 2 may be executed by the CPU to operate each component.

  Next, the foreign object detection process in the metal detection apparatus 1 according to the present embodiment will be described with reference to the flowcharts of FIGS. 9 and 10.

First, when the type of the inspection object W such as medicine, processed food, raw meat, and fish is determined, the height H of the inspection object W shown in FIG. 3 is input by the operator of the metal detection device 1 from the operation unit 12 or the like. Then, distances L _{1 to} L ₂ between the magnetized portion 4 and the conveyor belt upper surface 3d and the detection head portion lower surface 5a shown in FIG. 5 or 6 are set (step S10). The distances L _{1 to} L ₂ are set so that the distance S generated between the upper surface of the inspection object W and the lower surfaces of the magnetized portion 4 and the detection head portion 5 is minimized, that is, (L−H) (mm) is set. Set to be minimal. The value of the interval S is set based on the type, shape, size, and other inspection conditions of the inspection object W. When the distances L _{1 to} L ₂ are set, the height H, the interval S, and the distances L _{1 to} L _{2 of the} inspection object W are displayed on the display unit 11 as necessary.

When a production line of a predetermined type is started, the inspection object W is conveyed from the belt conveyor 48 installed upstream of the metal detection device 1, and the inspection object W is started to be carried into the conveying unit 3 shown in FIG. (Step S11). When the inspection object W starts to be carried in, the inspection object W passes through the magnetized portion 4, and the magnetic object mixed in the inspection object W when it passes is magnetized (step S12).
Next, when the inspection object W passes through the detection head unit 5, the magnetic flux released from the magnetic material magnetized by the magnetizing unit 4 and having residual magnetism causes the magnetic flux to be applied to the upper search coil and the lower search coil. A change occurs and a voltage is induced by a change in magnetic flux. Each induced voltage is time-integrated by an integration circuit to obtain a quantitative value, which is then amplified by a DC amplification circuit and a low-frequency signal component is extracted as an analog voltage signal through a low-pass filter. As a result, noise is removed. The analog signal from which noise has been removed is output to the analog-to-digital conversion circuit, converted to a digital signal, and output to the arithmetic processing circuit 21 (step S13).

When the arithmetic processing circuit 21 receives the signal, the reference digital signal recorded in the data memory 24 is read out by the arithmetic processing circuit 21, and the value of the digital signal received from the inspection head unit 5 and the value of the reference digital signal are read out. And the value of the calculated difference digital signal is output to the foreign matter determination circuit 22 (step S14).
When the foreign substance determination circuit 22 receives the difference digital signal, the reference difference digital signal that is a reference of determination recorded in advance in the data memory 24 is read out, and the value of the difference digital signal obtained from the inspection object W and the reference difference digital signal are read out. Are compared with each other, and it is determined whether or not the value of the difference digital signal of the inspection object W exceeds the value of the reference difference digital signal (step S14). When it is determined that the value of the difference digital signal of the magnetic material does not exceed the value of the reference difference digital signal (NO in step S14), the product is determined to be non-defective and the non-defective product sorting process is performed by the sorting unit 6 (step S16).
On the other hand, if it is determined that the value of the difference digital signal of the magnetic material exceeds the value of the reference difference digital signal (YES in step S14), it is determined as a defective product, and the sorting unit 6 performs defective product sorting processing. This is done (step S15).

  Next, the determination result of the inspection object W determined by the foreign matter determination circuit 22 is recorded in the data memory 24 (step S17). The determination result of the inspection object W is also displayed on the display unit 11 as necessary (step S18). For example, the judgment result is displayed in characters such as “OK”, “NG”, etc. along with the product type “hamburg”, lot number “No. XXX”, individual number “No. XXX”, etc. Is done.

Next, the number of the inspected objects W determined by the foreign matter determination circuit 22 is counted by a counter (step S19). The number of inspected objects W is the total number of non-defective products and defective products, and may be calculated from the first inspected object W that has been detected by the metal detection device 1, or from the middle of the inspection based on the inspection conditions. May be. Further, this number may be any number as long as the number of the inspected objects W that have been inspected can be counted. For example, the number of the inspected objects W detected by the detection head unit 5 may be used. But you can. This is because whether or not the distances L _{1 to} L ₂ set in step S10 are appropriate is reviewed for each predetermined number of detected magnetic substances. The predetermined number is set according to the type, shape, size, and other inspection conditions of the inspection object W.

Next, it is determined whether or not the count by the counter has reached a predetermined number (step S20). If the predetermined number has not been reached, the process proceeds to (C) in FIG. 9 and FIG. 10 to determine whether or not to continue the foreign object detection process (step S32). To do. When continuing, it progresses to (B) shown in FIG. 10 and FIG.
On the other hand, if the predetermined number has been reached (YES in step S20), the count by the counter is cleared (step S21), and it is input whether or not the distance L of the detection head unit 5 is reviewed and changed. The requested display is displayed on the display unit 11 (step S22).
The display of the input request may be a character display or a light display such as a lamp or LED.

Next, the system enters a state of waiting for an input of necessity of reviewing whether or not to review the distance L of the detection head unit 5 (step S23). Then, it progresses to (A) shown in FIG. 9 and FIG. It is determined whether or not there is an input for changing the interval L of the detection head unit 5 when a predetermined time, for example, several seconds to several minutes have elapsed since entering the input standby state (step S25). If there is no input to change the distance L, it is determined in step S32 whether or not to continue the foreign object detection process. If not, the foreign object detection process is terminated. When continuing, it progresses to (B) shown in FIG. 10 and FIG.
When an input to change the distance L is made (in the case of YES in step S25), the control circuit 28 in the transport control unit 7 is notified that there is a change, and the drive motor 27 is stopped by the control circuit 28. The transport unit 3 stops (step S26).
When the conveyor unit 3 stops, the handle 31 or grip 31a of the elevating unit 10 by the operator of the metal detection device 1 is operated, the distance L ₁ ~L ₂ of the detecting head portion 5 is adjusted to a suitable distance L, adjustment is completed This is input from the operation unit 12 (step S27).

Next, when the completion of adjustment is input from the operation unit 12, the adjusted distance L of the detection head unit 5 is detected by the distance detection unit 9, and corresponds to the ascent amount and the descent amount of the detection head unit 5. A voltage signal is output to the distance calculation circuit 23.
Next, when the distance calculation circuit 23 receives the voltage signal, the distance L shown in FIG. 3 is calculated based on the voltage signal output from the distance detection unit 9, and the calculated distance L value is output to the interval determination circuit 25. (Step S28).

Next, when the distance determination circuit 25 receives the value of the distance L, the distance S from the upper surface of the inspection object W to the detection head portion lower surface 5a is calculated (step S29). The interval S is expressed by the difference (L−H) between the distance L from the upper surface 3d of the conveyor belt to the lower surface 5a of the detection head and the height H of the inspection object W as described above. When the interval S is calculated, the upper limit value Lmax and the lower limit value Lmin stored in the data memory 24 are read out. Next, the interval S and the upper limit value Lmax are compared by the calculation and comparison circuit in the interval determination circuit 25, the interval S and the lower limit value Lmin are compared, and whether or not the interval S exceeds the upper limit value Lmax is determined. Is less than the lower limit Lmin, and it is determined whether or not the distance L after the final adjustment is appropriate (step S30).
When it is determined that the interval S is appropriate (in the case of YES in step S30), the interval determination result is output to the display unit 11 and the display screen displays that the interval L is appropriate so that the operator can visually recognize it. At the same time (step S31), it is output to the control circuit 28 in the transport control section 7 and used as control information for adjusting the transport speed of the transport section 3, stopping the transport, and changing the transport direction.

Next, it is determined whether or not to continue the foreign object detection process (step S32). If not, the foreign object detection process is terminated. When continuing, it progresses to (B) shown in FIG. 10 and FIG.
On the other hand, if it is determined that the interval L is not appropriate (NO in step S30), the interval determination result is output to the display unit 11 to indicate that the interval L is not appropriate so that the operator can visually recognize it. (Step S33). Further, assuming that the inspection object W is an uninspected object that has not yet been inspected, a notification of the uninspected object is output to the sorting unit 6 and is selected as an uninspected object (step S34). Further, the notification of the uninspected object is output to the data memory 24 and recorded corresponding to the inspected object W. Further, the notification of the uninspected object is also output to the display unit 11, and it is displayed on the display screen that the inspected object W is an uninspected object (step S35). Then, it progresses to step S27, the space | interval L of the detection head part 5 is readjusted, and it progresses to step S28 or later.

As described above, in the metal detection device 1 according to the present embodiment, a magnetic substance is mixed in the conveyance unit 3 that conveys the inspection object W and the inspection object W that is conveyed by the conveyance unit 3. In this case, the magnetized portion 4 for magnetizing the magnetic material, the detection head portion 5 for detecting the magnetization amount of the magnetic material magnetized by the magnetized portion 4, and the amount of magnetization detected by the detection head portion 5 are used. The foreign matter determination circuit 22 for determining whether or not a magnetic substance is mixed in the inspection object W, and the elevating part for raising and lowering both the magnetized part 4 and the detection head part 5 according to the height H of the inspection object W 10.
In addition, a distance calculating circuit 23 that detects a distance L from the upper surface 3d of the conveying belt of the conveying unit 3 to the lower surface 5a of the detecting head, and a detecting head from the upper surface of the inspection object W based on the distance L detected by the distance calculating circuit 23. An interval determination circuit 25 for determining the interval S to the lower part surface 5a and determining whether or not the interval S is within the range of the reference interval KS; and a display unit 11 for displaying the interval determination result determined by the interval determination circuit 25; Consists of.

  As a result, when the inspection object W is conveyed by the conveyance unit 3, if a magnetic object is mixed in the inspection object W, it is magnetized by the magnetizing unit 4 while being conveyed and is inspected. Passes through the detection head unit 5. The amount of magnetization of the magnetic material mixed in the inspection object W passing by the detection head unit 5 is detected, and a detection signal is output. When the detection signal is output, it is determined based on the amount of magnetization detected by the foreign substance determination circuit 22 whether or not a magnetic material is mixed in the inspection object W. Further, the elevating unit 10 is operated by the operator according to the height H of the inspection object W, and the magnetized part 4 and the detection are performed so that the distance S between the upper surface of the inspection object W and the lower surface 5a of the detection head unit is reduced. Both head parts 5 are raised and lowered.

  When both the magnetized unit 4 and the detection head unit 5 are moved up and down, the distance detection circuit 25 detects the distance L from the conveyance belt upper surface 3d of the conveyance unit 3 to the detection head lower surface 5a, and the distance determination circuit 25 detects the distance L. Is output. When the interval determination circuit 25 receives the output distance L, the interval detection circuit 25 obtains (L−H) as the interval S by subtracting the height H of the object W from the distance L. Next, the lower limit value Lmin and the upper limit value Lmax of the reference interval KS stored in the data memory 24 are read, and the read values of the lower limit value Lmin and the upper limit value Lmax are compared with the interval S. When the interval determination circuit 25 determines that the interval S exceeds the lower limit value Lmin and is less than the upper limit value Lmax, the interval determination result is output to the display unit 11 and the display unit 11 displays that the interval S is normal. Is done.

  When the display unit 11 displays that the interval S is normal, the operator can easily grasp that the adjusted interval S is appropriate. Further, the interval S after the adjustment as in the conventional metal detection device is neither too small nor too large, and the magnetization and the detection head in the magnetized portion 4 can be performed at the appropriate interval S after the adjustment. Since the amount of magnetization in the unit 5 is detected, the detection accuracy is improved and the inspection efficiency is also improved.

  Further, when the interval S is not within the range of the reference interval KS, the conveyance control unit 7 stops the conveyance unit 3. Since the transport unit 3 is stopped, it is possible to prevent a decrease in detection accuracy when the object W collides with the magnetized unit 4 when the interval is too small or when the interval is too large.

  On the other hand, when the interval S is not within the range of the reference interval KS, a notification signal that the inspection object W is an uninspected object is output. When a notification signal indicating that it is an uninspected object is output to the display unit 11, the operator can easily grasp that the object W to be inspected is an uninspected object, and take appropriate measures such as re-inspection. be able to.

  Further, when the interval S is not within the range of the reference interval KS, if the interval determination circuit 25 determines that the interval S is less than the lower limit value Lmin or exceeds the upper limit value Lmax, the interval S is abnormal. At least one of the presence and the stop of the conveyance unit 3 is displayed on the display unit 11. Further, it is displayed that the inspection object W is an uninspected object. When such a display is made, the operator can easily determine that the initially set distance L or the changed distance L from the upper surface 3d of the conveying belt of the conveying unit 3 to the lower surface 5a of the detecting head unit 5 is abnormal. Can grasp. Furthermore, it is possible to easily grasp that the conveyance unit 3 has stopped because the distance L is abnormal.

  As described above, the present invention can detect the distance between the upper surface of the conveyor belt and the lower surface of the detection head, can set the height of the detection head suitable for the height of the object to be inspected, has no false detection, and has a high height. A device that can detect magnetic substances with high accuracy and can detect metals with high inspection efficiency, and that detects foreign matters that are widely mixed in articles, for example, a sealed inspection device for printed matter with magnetism It is useful for metal detectors.

It is a perspective view which shows one Embodiment of the metal detection apparatus which concerns on this invention. It is a block diagram which shows one Embodiment of the metal detection apparatus which concerns on this invention. (A) is the schematic of the distance detection part attached to the apparatus main-body part in one Embodiment of the metal detection apparatus based on this invention. (B) is the wiring conceptual diagram of the distance detection part in one Embodiment of the metal detection apparatus which concerns on this invention. It is a graph which shows the relationship between the space | interval of the distance detection part in one Embodiment of the metal detection apparatus based on this invention, and a voltage. It is a conceptual diagram explaining the balance of the magnetization part and detection head part in one Embodiment of the metal detection apparatus which concerns on this invention. It is a conceptual diagram which shows the position which raised the magnetization part and the detection head part in one Embodiment of the metal detection apparatus which concerns on this invention. It is a perspective view which shows the raising / lowering part in one Embodiment of the metal detection apparatus which concerns on this invention. It is a perspective view which shows the raising / lowering part in one Embodiment of the metal detection apparatus which concerns on this invention. It is a flowchart which shows an example of the foreign material detection in one Embodiment of the metal detection apparatus which concerns on this invention. It is a flowchart which shows an example of the foreign material detection in one Embodiment of the metal detection apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal detection apparatus 2 Apparatus main-body part 2a Storage housing | casing 2b Base 2c, 2d Rod attachment part 3 Conveyance part (conveyance means)
3a, 3b Pulley 3c Conveying belt 3d Conveying belt upper surface 4 Magnetized portion (magnetizing means)
5 Detection head (detection means)
5a Detection head section lower surface 6 Sorting section 6a Transport conveyor 6b Pulley 6c Transport belt 7 Transport control section 8 Foreign matter detection section (determination means)
9 Distance detector (distance calculation means)
9a Rod part 9b Brush part 9c Brush support part 9d Connection part 10 Lifting part (lifting means)
11 Display section (display means)
Reference Signs List 12 Operation part 13, 14 Extension coil spring 15 Connection part 15a Through hole 15b, 15c Spring support part 16 Elevating mechanism part (elevating means)
17 Guide part 17a Rod part 17b, 17c, 17d, 17e Guide roller part 21 Arithmetic processing circuit 22 Foreign matter determination circuit (determination means)
23 Distance calculation circuit (distance calculation means)
Reference Signs List 24 data memory 25 interval determination circuit 27 drive motor 28 control circuit 30 linear guide 30a upper plate 30b lower plate 31 handle 31a grip 32 holder 33 ball screw rod 34 slider 34a screw hole 34b bolt 34c washer 40 lifting mechanism (lifting means)
41 belt drive 41a servomotor 41b, 41c pulley 41d timing belt 48 belt conveyor 50 pulling force of the linear guide 50a upper plate 50b lower plate 51 ball screw rod 52 slider 52a screw hole 52b bolt 52c washer B brush F _{1, F 2} tension spring Horizontal distance from FL ₁ P to F ₁ Horizontal distance from FL ₂ P to F ₂ G ₁ Center of gravity of magnetized part G ₂ Center of gravity of detection head KS Reference interval Lmin Lower limit Lmax Upper limit L, L ₁ , L ₂ transport Distance from upper surface of belt to lower surface of detection head P Support point R Resistance S Distance from upper surface of inspection object W to lower surface of detection head T ₁ , T ₂ , T ₃ terminal W Inspection object W ₁ Load of magnetized portion W horizontal distance WL ₂ from the load WL ₁ P ₂ detection head unit to _{G 1} Horizontal distance from up to _{G 2}

Claims (5)

A transport means for transporting an object to be inspected;
Magnetizing means for magnetizing a magnetic material contained in the inspection object being conveyed by the conveying means;
Detecting means for detecting the amount of magnetization of the magnetic material magnetized by the magnetizing means;
Determination means for determining the quality of the inspection object based on the amount of magnetization detected by the detection means;
In a metal detection apparatus comprising: elevating means for elevating and lowering both the magnetization means and the detection means according to the height of the inspection object,
A data memory for storing a predetermined height H corresponding to the type of the inspection object and a reference interval KS;
A distance calculating means for detecting a distance L from the upper surface of the conveying belt of the conveying means to the lower surface of the detecting head portion of the detecting means; the distance L detected by the distance calculating means; and the height H stored in the data memory and spacing determining means for determining whether or not the seek distance S from the upper surface of the object to the detection head bottom surface, the distance S is within the range of the reference interval KS based on, by the interval determining means A metal detection apparatus comprising: a display unit that displays the determined interval determination result. A conveyance control means for controlling the conveyance means;
The metal detection apparatus according to claim 1, wherein the transport control unit controls at least one of a transport speed and a transport direction of the transport unit according to the interval determination result.   When the interval S is not within the range of the reference interval KS, the interval determining means outputs an uninspected object notification signal for notifying that the inspected object has not been inspected yet. The metal detection device according to claim 1, wherein the metal detection device is a metal detector.   The metal detection apparatus according to claim 3, wherein the display unit displays the uninspected object notification signal and displays that the inspected object is an uninspected object that has not been inspected yet.   5. The metal detection device according to claim 2, wherein when the interval S is not within the range of the reference interval KS, the control content of the transport control unit is displayed on the display unit. 6. .

Images